blob: 7090d59f6f106f4136f1b1a423384eb899cf90c5 [file] [log] [blame]
Peter Maydelld95f2602023-12-12 16:23:13 +00001HXCOMM See docs/devel/docs.rst for the format of this file.
2HXCOMM
Peter Maydell3c95fde2020-03-06 17:17:44 +00003HXCOMM Use DEFHEADING() to define headings in both help text and rST.
4HXCOMM Text between SRST and ERST is copied to the rST version and
5HXCOMM discarded from C version.
Blue Swirlad960902010-03-29 19:23:52 +00006HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to
7HXCOMM construct option structures, enums and help message for specified
8HXCOMM architectures.
Peter Maydell3c95fde2020-03-06 17:17:44 +00009HXCOMM HXCOMM can be used for comments, discarded from both rST and C.
blueswir15824d652009-03-28 06:44:27 +000010
Markus Armbrusterde6b4f92017-10-02 16:03:00 +020011DEFHEADING(Standard options:)
blueswir15824d652009-03-28 06:44:27 +000012
13DEF("help", 0, QEMU_OPTION_h,
Blue Swirlad960902010-03-29 19:23:52 +000014 "-h or -help display this help and exit\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +000015SRST
16``-h``
17 Display help and exit
18ERST
blueswir15824d652009-03-28 06:44:27 +000019
pbrook9bd7e6d2009-04-07 22:58:45 +000020DEF("version", 0, QEMU_OPTION_version,
Blue Swirlad960902010-03-29 19:23:52 +000021 "-version display version information and exit\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +000022SRST
23``-version``
24 Display version information and exit
25ERST
pbrook9bd7e6d2009-04-07 22:58:45 +000026
Jan Kiszka80f52a62011-07-23 12:39:46 +020027DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
28 "-machine [type=]name[,prop[=value][,...]]\n"
Peter Maydell585f6032012-10-04 16:22:01 +010029 " selects emulated machine ('-machine help' for list)\n"
Jan Kiszka80f52a62011-07-23 12:39:46 +020030 " property accel=accel1[:accel2[:...]] selects accelerator\n"
Philippe Mathieu-Daudéb91b0fc2023-06-24 00:52:29 +020031 " supported accelerators are kvm, xen, hvf, nvmm, whpx or tcg (default: tcg)\n"
Don Slutzd1048be2014-11-21 11:18:52 -050032 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
Luiz Capitulino8490fc72012-09-05 16:50:16 -030033 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
Le Tana52a7fd2014-08-16 13:55:40 +080034 " mem-merge=on|off controls memory merge support (default: on)\n"
Tony Krowiak2eb1cd02015-03-12 13:53:51 +010035 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
Alexander Graf9850c602015-02-23 13:56:42 +010036 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
Xiao Guangrong87252e12015-12-02 15:20:58 +080037 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
Greg Kurz902c0532016-02-18 12:32:25 +010038 " nvdimm=on|off controls NVDIMM support (default=off)\n"
Tao Xu244b3f42019-12-13 09:19:22 +080039 " memory-encryption=@var{} memory encryption object to use (default=none)\n"
Igor Mammedov8db0b202021-01-21 11:15:04 -050040 " hmat=on|off controls ACPI HMAT support (default=off)\n"
Jonathan Cameron03b39fc2022-06-08 15:54:33 +010041 " memory-backend='backend-id' specifies explicitly provided backend for main RAM (default=none)\n"
Cédric Le Goater57702892022-11-07 17:13:48 +010042 " cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]\n",
Jan Kiszka80f52a62011-07-23 12:39:46 +020043 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +000044SRST
45``-machine [type=]name[,prop=value[,...]]``
46 Select the emulated machine by name. Use ``-machine help`` to list
47 available machines.
48
49 For architectures which aim to support live migration compatibility
50 across releases, each release will introduce a new versioned machine
51 type. For example, the 2.8.0 release introduced machine types
52 "pc-i440fx-2.8" and "pc-q35-2.8" for the x86\_64/i686 architectures.
53
54 To allow live migration of guests from QEMU version 2.8.0, to QEMU
55 version 2.9.0, the 2.9.0 version must support the "pc-i440fx-2.8"
56 and "pc-q35-2.8" machines too. To allow users live migrating VMs to
57 skip multiple intermediate releases when upgrading, new releases of
58 QEMU will support machine types from many previous versions.
59
60 Supported machine properties are:
61
62 ``accel=accels1[:accels2[:...]]``
63 This is used to enable an accelerator. Depending on the target
Philippe Mathieu-Daudéb91b0fc2023-06-24 00:52:29 +020064 architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available.
Peter Maydelle2fcbf42020-03-06 10:07:14 +000065 By default, tcg is used. If there is more than one accelerator
66 specified, the next one is used if the previous one fails to
67 initialize.
68
69 ``vmport=on|off|auto``
70 Enables emulation of VMWare IO port, for vmmouse etc. auto says
Kamil Szczęk702cbdc2024-08-17 15:26:15 +000071 to select the value based on accel and i8042. For accel=xen or
72 i8042=off the default is off otherwise the default is on.
Peter Maydelle2fcbf42020-03-06 10:07:14 +000073
74 ``dump-guest-core=on|off``
75 Include guest memory in a core dump. The default is on.
76
77 ``mem-merge=on|off``
78 Enables or disables memory merge support. This feature, when
79 supported by the host, de-duplicates identical memory pages
80 among VMs instances (enabled by default).
81
82 ``aes-key-wrap=on|off``
83 Enables or disables AES key wrapping support on s390-ccw hosts.
84 This feature controls whether AES wrapping keys will be created
85 to allow execution of AES cryptographic functions. The default
86 is on.
87
88 ``dea-key-wrap=on|off``
89 Enables or disables DEA key wrapping support on s390-ccw hosts.
90 This feature controls whether DEA wrapping keys will be created
91 to allow execution of DEA cryptographic functions. The default
92 is on.
93
94 ``nvdimm=on|off``
95 Enables or disables NVDIMM support. The default is off.
96
Peter Maydelle2fcbf42020-03-06 10:07:14 +000097 ``memory-encryption=``
98 Memory encryption object to use. The default is none.
99
100 ``hmat=on|off``
101 Enables or disables ACPI Heterogeneous Memory Attribute Table
102 (HMAT) support. The default is off.
Igor Mammedov8db0b202021-01-21 11:15:04 -0500103
Peter Maydell95355822021-07-19 11:52:57 +0100104 ``memory-backend='id'``
Igor Mammedov8db0b202021-01-21 11:15:04 -0500105 An alternative to legacy ``-mem-path`` and ``mem-prealloc`` options.
106 Allows to use a memory backend as main RAM.
107
108 For example:
109 ::
Peter Maydell95355822021-07-19 11:52:57 +0100110
111 -object memory-backend-file,id=pc.ram,size=512M,mem-path=/hugetlbfs,prealloc=on,share=on
112 -machine memory-backend=pc.ram
113 -m 512M
Igor Mammedov8db0b202021-01-21 11:15:04 -0500114
115 Migration compatibility note:
Peter Maydell95355822021-07-19 11:52:57 +0100116
117 * as backend id one shall use value of 'default-ram-id', advertised by
118 machine type (available via ``query-machines`` QMP command), if migration
119 to/from old QEMU (<5.0) is expected.
120 * for machine types 4.0 and older, user shall
121 use ``x-use-canonical-path-for-ramblock-id=off`` backend option
122 if migration to/from old QEMU (<5.0) is expected.
123
Igor Mammedov8db0b202021-01-21 11:15:04 -0500124 For example:
125 ::
Peter Maydell95355822021-07-19 11:52:57 +0100126
127 -object memory-backend-ram,id=pc.ram,size=512M,x-use-canonical-path-for-ramblock-id=off
128 -machine memory-backend=pc.ram
129 -m 512M
Jonathan Cameron03b39fc2022-06-08 15:54:33 +0100130
131 ``cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]``
132 Define a CXL Fixed Memory Window (CFMW).
133
134 Described in the CXL 2.0 ECN: CEDT CFMWS & QTG _DSM.
135
136 They are regions of Host Physical Addresses (HPA) on a system which
137 may be interleaved across one or more CXL host bridges. The system
138 software will assign particular devices into these windows and
139 configure the downstream Host-managed Device Memory (HDM) decoders
140 in root ports, switch ports and devices appropriately to meet the
141 interleave requirements before enabling the memory devices.
142
143 ``targets.X=target`` provides the mapping to CXL host bridges
Stefan Weil2cb40d42022-11-10 20:08:25 +0100144 which may be identified by the id provided in the -device entry.
Jonathan Cameron03b39fc2022-06-08 15:54:33 +0100145 Multiple entries are needed to specify all the targets when
146 the fixed memory window represents interleaved memory. X is the
147 target index from 0.
148
149 ``size=size`` sets the size of the CFMW. This must be a multiple of
150 256MiB. The region will be aligned to 256MiB but the location is
151 platform and configuration dependent.
152
153 ``interleave-granularity=granularity`` sets the granularity of
Yuquan Wangaa88f992024-04-07 16:35:39 +0800154 interleave. Default 256 (bytes). Only 256, 512, 1k, 2k,
155 4k, 8k and 16k granularities supported.
Jonathan Cameron03b39fc2022-06-08 15:54:33 +0100156
157 Example:
158
159 ::
160
Yuquan Wangaa88f992024-04-07 16:35:39 +0800161 -machine cxl-fmw.0.targets.0=cxl.0,cxl-fmw.0.targets.1=cxl.1,cxl-fmw.0.size=128G,cxl-fmw.0.interleave-granularity=512
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000162ERST
blueswir15824d652009-03-28 06:44:27 +0000163
Sean Christophersondfce81f2021-09-28 10:40:58 +0200164DEF("M", HAS_ARG, QEMU_OPTION_M,
Yang Zhong11058122021-11-01 12:20:05 -0400165 " sgx-epc.0.memdev=memid,sgx-epc.0.node=numaid\n",
Sean Christophersondfce81f2021-09-28 10:40:58 +0200166 QEMU_ARCH_ALL)
167
168SRST
Yang Zhong11058122021-11-01 12:20:05 -0400169``sgx-epc.0.memdev=@var{memid},sgx-epc.0.node=@var{numaid}``
Sean Christophersondfce81f2021-09-28 10:40:58 +0200170 Define an SGX EPC section.
171ERST
Jan Kiszka80f52a62011-07-23 12:39:46 +0200172
blueswir15824d652009-03-28 06:44:27 +0000173DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
Peter Maydell585f6032012-10-04 16:22:01 +0100174 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000175SRST
176``-cpu model``
177 Select CPU model (``-cpu help`` for list and additional feature
178 selection)
179ERST
blueswir15824d652009-03-28 06:44:27 +0000180
KONRAD Frederic8d4e9142017-02-23 18:29:08 +0000181DEF("accel", HAS_ARG, QEMU_OPTION_accel,
Paolo Bonzinife174132019-11-13 15:16:44 +0100182 "-accel [accel=]accelerator[,prop[=value][,...]]\n"
Philippe Mathieu-Daudéb91b0fc2023-06-24 00:52:29 +0200183 " select accelerator (kvm, xen, hvf, nvmm, whpx or tcg; use 'help' for a list)\n"
Paolo Bonzini46472d82019-11-13 10:56:53 +0100184 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n"
Paolo Bonzini11bc4a12019-11-13 10:56:53 +0100185 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n"
Paolo Bonzini23b08982019-11-13 10:56:53 +0100186 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n"
Peter Maydell3cfb0452023-04-17 17:40:32 +0100187 " one-insn-per-tb=on|off (one guest instruction per TCG translation block)\n"
Richard Hendersona35b3e12020-10-28 20:50:29 -0700188 " split-wx=on|off (enable TCG split w^x mapping)\n"
Paolo Bonzinife174132019-11-13 15:16:44 +0100189 " tb-size=n (TCG translation block cache size)\n"
Peter Xu2ea5cb02021-05-06 12:05:47 -0400190 " dirty-ring-size=n (KVM dirty ring GFN count, default 0)\n"
Shameer Kolothumc8f2eb52023-09-05 10:12:46 +0100191 " eager-split-size=n (KVM Eager Page Split chunk size, default 0, disabled. ARM only)\n"
Chenyi Qiange2e69f62022-09-29 15:20:14 +0800192 " notify-vmexit=run|internal-error|disable,notify-window=n (enable notify VM exit and set notify window, x86 only)\n"
Daan De Meyeraef158b2023-10-21 15:40:15 +0200193 " thread=single|multi (enable multi-threaded TCG)\n"
194 " device=path (KVM device path, default /dev/kvm)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000195SRST
196``-accel name[,prop=value[,...]]``
197 This is used to enable an accelerator. Depending on the target
Philippe Mathieu-Daudéb91b0fc2023-06-24 00:52:29 +0200198 architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available. By
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000199 default, tcg is used. If there is more than one accelerator
200 specified, the next one is used if the previous one fails to
201 initialize.
202
203 ``igd-passthru=on|off``
204 When Xen is in use, this option controls whether Intel
205 integrated graphics devices can be passed through to the guest
206 (default=off)
207
208 ``kernel-irqchip=on|off|split``
209 Controls KVM in-kernel irqchip support. The default is full
210 acceleration of the interrupt controllers. On x86, split irqchip
211 reduces the kernel attack surface, at a performance cost for
212 non-MSI interrupts. Disabling the in-kernel irqchip completely
213 is not recommended except for debugging purposes.
214
215 ``kvm-shadow-mem=size``
216 Defines the size of the KVM shadow MMU.
217
Peter Maydell3cfb0452023-04-17 17:40:32 +0100218 ``one-insn-per-tb=on|off``
219 Makes the TCG accelerator put only one guest instruction into
220 each translation block. This slows down emulation a lot, but
221 can be useful in some situations, such as when trying to analyse
222 the logs produced by the ``-d`` option.
223
Richard Hendersona35b3e12020-10-28 20:50:29 -0700224 ``split-wx=on|off``
225 Controls the use of split w^x mapping for the TCG code generation
226 buffer. Some operating systems require this to be enabled, and in
227 such a case this will default on. On other operating systems, this
228 will default off, but one may enable this for testing or debugging.
229
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000230 ``tb-size=n``
231 Controls the size (in MiB) of the TCG translation block cache.
232
233 ``thread=single|multi``
234 Controls number of TCG threads. When the TCG is multi-threaded
Michael Tokarevcba42d62021-03-09 14:15:10 +0300235 there will be one thread per vCPU therefore taking advantage of
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000236 additional host cores. The default is to enable multi-threading
237 where both the back-end and front-ends support it and no
238 incompatible TCG features have been enabled (e.g.
239 icount/replay).
Peter Xu2ea5cb02021-05-06 12:05:47 -0400240
241 ``dirty-ring-size=n``
242 When the KVM accelerator is used, it controls the size of the per-vCPU
243 dirty page ring buffer (number of entries for each vCPU). It should
244 be a value that is power of two, and it should be 1024 or bigger (but
245 still less than the maximum value that the kernel supports). 4096
246 could be a good initial value if you have no idea which is the best.
247 Set this value to 0 to disable the feature. By default, this feature
248 is disabled (dirty-ring-size=0). When enabled, KVM will instead
249 record dirty pages in a bitmap.
250
Shameer Kolothumc8f2eb52023-09-05 10:12:46 +0100251 ``eager-split-size=n``
252 KVM implements dirty page logging at the PAGE_SIZE granularity and
253 enabling dirty-logging on a huge-page requires breaking it into
254 PAGE_SIZE pages in the first place. KVM on ARM does this splitting
255 lazily by default. There are performance benefits in doing huge-page
256 split eagerly, especially in situations where TLBI costs associated
257 with break-before-make sequences are considerable and also if guest
258 workloads are read intensive. The size here specifies how many pages
259 to break at a time and needs to be a valid block size which is
260 1GB/2MB/4KB, 32MB/16KB and 512MB/64KB for 4KB/16KB/64KB PAGE_SIZE
261 respectively. Be wary of specifying a higher size as it will have an
262 impact on the memory. By default, this feature is disabled
263 (eager-split-size=0).
264
Chenyi Qiange2e69f62022-09-29 15:20:14 +0800265 ``notify-vmexit=run|internal-error|disable,notify-window=n``
266 Enables or disables notify VM exit support on x86 host and specify
267 the corresponding notify window to trigger the VM exit if enabled.
268 ``run`` option enables the feature. It does nothing and continue
269 if the exit happens. ``internal-error`` option enables the feature.
270 It raises a internal error. ``disable`` option doesn't enable the feature.
271 This feature can mitigate the CPU stuck issue due to event windows don't
272 open up for a specified of time (i.e. notify-window).
273 Default: notify-vmexit=run,notify-window=0.
274
Daan De Meyeraef158b2023-10-21 15:40:15 +0200275 ``device=path``
276 Sets the path to the KVM device node. Defaults to ``/dev/kvm``. This
277 option can be used to pass the KVM device to use via a file descriptor
278 by setting the value to ``/dev/fdset/NN``.
279
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000280ERST
KONRAD Frederic8d4e9142017-02-23 18:29:08 +0000281
blueswir15824d652009-03-28 06:44:27 +0000282DEF("smp", HAS_ARG, QEMU_OPTION_smp,
Pierre Morel5de1aff2023-10-16 20:39:06 +0200283 "-smp [[cpus=]n][,maxcpus=maxcpus][,drawers=drawers][,books=books][,sockets=sockets]\n"
Zhao Liu68074872024-04-24 23:49:26 +0800284 " [,dies=dies][,clusters=clusters][,modules=modules][,cores=cores]\n"
285 " [,threads=threads]\n"
Yanan Wang0d871782021-12-28 17:22:08 +0800286 " set the number of initial CPUs to 'n' [default=1]\n"
Daniel P. Berrangéce8ee7c2021-06-22 15:30:43 +0100287 " maxcpus= maximum number of total CPUs, including\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -0700288 " offline CPUs for hotplug, etc\n"
Pierre Morel5de1aff2023-10-16 20:39:06 +0200289 " drawers= number of drawers on the machine board\n"
290 " books= number of books in one drawer\n"
291 " sockets= number of sockets in one book\n"
Yanan Wang0d871782021-12-28 17:22:08 +0800292 " dies= number of dies in one socket\n"
Yanan Wang864c3b52021-12-28 17:22:09 +0800293 " clusters= number of clusters in one die\n"
Zhao Liu68074872024-04-24 23:49:26 +0800294 " modules= number of modules in one cluster\n"
295 " cores= number of cores in one module\n"
Yanan Wang0d871782021-12-28 17:22:08 +0800296 " threads= number of threads in one core\n"
297 "Note: Different machines may have different subsets of the CPU topology\n"
298 " parameters supported, so the actual meaning of the supported parameters\n"
299 " will vary accordingly. For example, for a machine type that supports a\n"
300 " three-level CPU hierarchy of sockets/cores/threads, the parameters will\n"
301 " sequentially mean as below:\n"
302 " sockets means the number of sockets on the machine board\n"
303 " cores means the number of cores in one socket\n"
304 " threads means the number of threads in one core\n"
305 " For a particular machine type board, an expected CPU topology hierarchy\n"
306 " can be defined through the supported sub-option. Unsupported parameters\n"
307 " can also be provided in addition to the sub-option, but their values\n"
308 " must be set as 1 in the purpose of correct parsing.\n",
309 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000310SRST
Zhao Liu68074872024-04-24 23:49:26 +0800311``-smp [[cpus=]n][,maxcpus=maxcpus][,drawers=drawers][,books=books][,sockets=sockets][,dies=dies][,clusters=clusters][,modules=modules][,cores=cores][,threads=threads]``
Daniel P. Berrangé80d78352021-06-22 16:17:09 +0100312 Simulate a SMP system with '\ ``n``\ ' CPUs initially present on
313 the machine type board. On boards supporting CPU hotplug, the optional
314 '\ ``maxcpus``\ ' parameter can be set to enable further CPUs to be
Yanan Wang7d8c5a32021-09-29 10:58:05 +0800315 added at runtime. When both parameters are omitted, the maximum number
316 of CPUs will be calculated from the provided topology members and the
317 initial CPU count will match the maximum number. When only one of them
318 is given then the omitted one will be set to its counterpart's value.
319 Both parameters may be specified, but the maximum number of CPUs must
Yanan Wang0d871782021-12-28 17:22:08 +0800320 be equal to or greater than the initial CPU count. Product of the
321 CPU topology hierarchy must be equal to the maximum number of CPUs.
322 Both parameters are subject to an upper limit that is determined by
323 the specific machine type chosen.
Daniel P. Berrangé80d78352021-06-22 16:17:09 +0100324
Yanan Wang0d871782021-12-28 17:22:08 +0800325 To control reporting of CPU topology information, values of the topology
326 parameters can be specified. Machines may only support a subset of the
327 parameters and different machines may have different subsets supported
328 which vary depending on capacity of the corresponding CPU targets. So
329 for a particular machine type board, an expected topology hierarchy can
330 be defined through the supported sub-option. Unsupported parameters can
331 also be provided in addition to the sub-option, but their values must be
332 set as 1 in the purpose of correct parsing.
Daniel P. Berrangé80d78352021-06-22 16:17:09 +0100333
334 Either the initial CPU count, or at least one of the topology parameters
Yanan Wangc2511b12021-09-29 10:58:02 +0800335 must be specified. The specified parameters must be greater than zero,
336 explicit configuration like "cpus=0" is not allowed. Values for any
337 omitted parameters will be computed from those which are given.
Yanan Wang0d871782021-12-28 17:22:08 +0800338
339 For example, the following sub-option defines a CPU topology hierarchy
340 (2 sockets totally on the machine, 2 cores per socket, 2 threads per
341 core) for a machine that only supports sockets/cores/threads.
342 Some members of the option can be omitted but their values will be
343 automatically computed:
344
345 ::
346
347 -smp 8,sockets=2,cores=2,threads=2,maxcpus=8
348
349 The following sub-option defines a CPU topology hierarchy (2 sockets
Zhao Liu68074872024-04-24 23:49:26 +0800350 totally on the machine, 2 dies per socket, 2 modules per die, 2 cores per
351 module, 2 threads per core) for PC machines which support sockets/dies
352 /modules/cores/threads. Some members of the option can be omitted but
353 their values will be automatically computed:
Yanan Wang0d871782021-12-28 17:22:08 +0800354
355 ::
356
Zhao Liu68074872024-04-24 23:49:26 +0800357 -smp 32,sockets=2,dies=2,modules=2,cores=2,threads=2,maxcpus=32
Yanan Wang0d871782021-12-28 17:22:08 +0800358
Yanan Wangd55c3162022-01-07 16:32:27 +0800359 The following sub-option defines a CPU topology hierarchy (2 sockets
360 totally on the machine, 2 clusters per socket, 2 cores per cluster,
361 2 threads per core) for ARM virt machines which support sockets/clusters
362 /cores/threads. Some members of the option can be omitted but their values
363 will be automatically computed:
364
365 ::
366
367 -smp 16,sockets=2,clusters=2,cores=2,threads=2,maxcpus=16
368
Yanan Wangc2511b12021-09-29 10:58:02 +0800369 Historically preference was given to the coarsest topology parameters
370 when computing missing values (ie sockets preferred over cores, which
371 were preferred over threads), however, this behaviour is considered
Yanan Wang4a0af292021-09-29 10:58:09 +0800372 liable to change. Prior to 6.2 the preference was sockets over cores
373 over threads. Since 6.2 the preference is cores over sockets over threads.
Yanan Wang0d871782021-12-28 17:22:08 +0800374
375 For example, the following option defines a machine board with 2 sockets
376 of 1 core before 6.2 and 1 socket of 2 cores after 6.2:
377
378 ::
379
380 -smp 2
Yicong Yang97f4eff2022-12-29 14:55:09 +0800381
382 Note: The cluster topology will only be generated in ACPI and exposed
383 to guest if it's explicitly specified in -smp.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000384ERST
blueswir15824d652009-03-28 06:44:27 +0000385
aliguori268a3622009-04-21 22:30:27 +0000386DEF("numa", HAS_ARG, QEMU_OPTION_numa,
Tao Xu244b3f42019-12-13 09:19:22 +0800387 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n"
388 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n"
Igor Mammedov2d19c652017-11-28 15:53:58 +0100389 "-numa dist,src=source,dst=destination,val=distance\n"
Liu Jingqi9b12dfa2019-12-13 09:19:23 +0800390 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n"
Liu Jingqic412a482019-12-13 09:19:24 +0800391 "-numa hmat-lb,initiator=node,target=node,hierarchy=memory|first-level|second-level|third-level,data-type=access-latency|read-latency|write-latency[,latency=lat][,bandwidth=bw]\n"
392 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n",
Igor Mammedov2d19c652017-11-28 15:53:58 +0100393 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000394SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000395``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]``
396 \
397``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]``
398 \
399``-numa dist,src=source,dst=destination,val=distance``
400 \
401``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]``
402 \
Stefan Weil2cb40d42022-11-10 20:08:25 +0100403``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=type[,latency=lat][,bandwidth=bw]``
Peter Maydell09ce5f22020-02-28 15:36:13 +0000404 \
405``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000406 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA
407 distance from a source node to a destination node. Set the ACPI
408 Heterogeneous Memory Attributes for the given nodes.
409
410 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and
411 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a
412 contiguous range of CPU indexes (or a single VCPU if lastcpu is
413 omitted). A non-contiguous set of VCPUs can be represented by
414 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is
415 omitted on all nodes, VCPUs are automatically split between them.
416
417 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a
418 NUMA node:
419
420 ::
421
422 -numa node,cpus=0-2,cpus=5
423
424 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option
425 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to
426 assign CPU objects to a node using topology layout properties of
427 CPU. The set of properties is machine specific, and depends on used
428 machine type/'\ ``smp``\ ' options. It could be queried with
429 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ '
430 property specifies node to which CPU object will be assigned, it's
431 required for node to be declared with '\ ``node``\ ' option before
432 it's used with '\ ``cpu``\ ' option.
433
434 For example:
435
436 ::
437
438 -M pc \
439 -smp 1,sockets=2,maxcpus=2 \
440 -numa node,nodeid=0 -numa node,nodeid=1 \
441 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
442
Yohei Kojima4f513982023-04-24 10:22:45 +0100443 '\ ``memdev``\ ' option assigns RAM from a given memory backend
444 device to a node. It is recommended to use '\ ``memdev``\ ' option
445 over legacy '\ ``mem``\ ' option. This is because '\ ``memdev``\ '
446 option provides better performance and more control over the
447 backend's RAM (e.g. '\ ``prealloc``\ ' parameter of
448 '\ ``-memory-backend-ram``\ ' allows memory preallocation).
Igor Mammedov32a354d2020-06-09 09:56:35 -0400449
Yohei Kojima4f513982023-04-24 10:22:45 +0100450 For compatibility reasons, legacy '\ ``mem``\ ' option is
451 supported in 5.0 and older machine types. Note that '\ ``mem``\ '
452 and '\ ``memdev``\ ' are mutually exclusive. If one node uses
453 '\ ``memdev``\ ', the rest nodes have to use '\ ``memdev``\ '
454 option, and vice versa.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000455
Yohei Kojima4f513982023-04-24 10:22:45 +0100456 Users must specify memory for all NUMA nodes by '\ ``memdev``\ '
457 (or legacy '\ ``mem``\ ' if available). In QEMU 5.2, the support
458 for '\ ``-numa node``\ ' without memory specified was removed.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000459
460 '\ ``initiator``\ ' is an additional option that points to an
461 initiator NUMA node that has best performance (the lowest latency or
462 largest bandwidth) to this NUMA node. Note that this option can be
463 set only when the machine property 'hmat' is set to 'on'.
464
465 Following example creates a machine with 2 NUMA nodes, node 0 has
466 CPU. node 1 has only memory, and its initiator is node 0. Note that
467 because node 0 has CPU, by default the initiator of node 0 is itself
468 and must be itself.
469
470 ::
471
472 -machine hmat=on \
473 -m 2G,slots=2,maxmem=4G \
474 -object memory-backend-ram,size=1G,id=m0 \
475 -object memory-backend-ram,size=1G,id=m1 \
476 -numa node,nodeid=0,memdev=m0 \
477 -numa node,nodeid=1,memdev=m1,initiator=0 \
478 -smp 2,sockets=2,maxcpus=2 \
479 -numa cpu,node-id=0,socket-id=0 \
480 -numa cpu,node-id=0,socket-id=1
481
482 source and destination are NUMA node IDs. distance is the NUMA
483 distance from source to destination. The distance from a node to
484 itself is always 10. If any pair of nodes is given a distance, then
485 all pairs must be given distances. Although, when distances are only
486 given in one direction for each pair of nodes, then the distances in
487 the opposite directions are assumed to be the same. If, however, an
488 asymmetrical pair of distances is given for even one node pair, then
489 all node pairs must be provided distance values for both directions,
490 even when they are symmetrical. When a node is unreachable from
491 another node, set the pair's distance to 255.
492
493 Note that the -``numa`` option doesn't allocate any of the specified
494 resources, it just assigns existing resources to NUMA nodes. This
495 means that one still has to use the ``-m``, ``-smp`` options to
496 allocate RAM and VCPUs respectively.
497
498 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth
499 Information between initiator and target NUMA nodes in ACPI
500 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can
501 create memory requests, usually it has one or more processors.
502 Target NUMA node contains addressable memory.
503
504 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is
505 the memory hierarchy of the target NUMA node: if hierarchy is
506 'memory', the structure represents the memory performance; if
507 hierarchy is 'first-level\|second-level\|third-level', this
508 structure represents aggregated performance of memory side caches
509 for each domain. type of 'data-type' is type of data represented by
510 this structure instance: if 'hierarchy' is 'memory', 'data-type' is
511 'access\|read\|write' latency or 'access\|read\|write' bandwidth of
512 the target memory; if 'hierarchy' is
513 'first-level\|second-level\|third-level', 'data-type' is
514 'access\|read\|write' hit latency or 'access\|read\|write' hit
515 bandwidth of the target memory side cache.
516
517 lat is latency value in nanoseconds. bw is bandwidth value, the
518 possible value and units are NUM[M\|G\|T], mean that the bandwidth
519 value are NUM byte per second (or MB/s, GB/s or TB/s depending on
520 used suffix). Note that if latency or bandwidth value is 0, means
521 the corresponding latency or bandwidth information is not provided.
522
523 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory
524 belongs. size is the size of memory side cache in bytes. level is
525 the cache level described in this structure, note that the cache
526 level 0 should not be used with '\ ``hmat-cache``\ ' option.
527 associativity is the cache associativity, the possible value is
528 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy
529 is the write policy. line is the cache Line size in bytes.
530
531 For example, the following options describe 2 NUMA nodes. Node 0 has
532 2 cpus and a ram, node 1 has only a ram. The processors in node 0
533 access memory in node 0 with access-latency 5 nanoseconds,
534 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access
535 memory in NUMA node 1 with access-latency 10 nanoseconds,
536 access-bandwidth is 100 MB/s. And for memory side cache information,
537 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB,
538 policy is write-back, the cache Line size is 8 bytes:
539
540 ::
541
542 -machine hmat=on \
543 -m 2G \
544 -object memory-backend-ram,size=1G,id=m0 \
545 -object memory-backend-ram,size=1G,id=m1 \
Yanan Wang848dd262021-09-28 20:11:34 +0800546 -smp 2,sockets=2,maxcpus=2 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000547 -numa node,nodeid=0,memdev=m0 \
548 -numa node,nodeid=1,memdev=m1,initiator=0 \
549 -numa cpu,node-id=0,socket-id=0 \
550 -numa cpu,node-id=0,socket-id=1 \
551 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \
552 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \
553 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \
554 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \
555 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \
556 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8
557ERST
aliguori268a3622009-04-21 22:30:27 +0000558
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100559DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
560 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
561 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000562SRST
563``-add-fd fd=fd,set=set[,opaque=opaque]``
564 Add a file descriptor to an fd set. Valid options are:
565
566 ``fd=fd``
567 This option defines the file descriptor of which a duplicate is
568 added to fd set. The file descriptor cannot be stdin, stdout, or
569 stderr.
570
571 ``set=set``
572 This option defines the ID of the fd set to add the file
573 descriptor to.
574
575 ``opaque=opaque``
576 This option defines a free-form string that can be used to
577 describe fd.
578
579 You can open an image using pre-opened file descriptors from an fd
580 set:
581
582 .. parsed-literal::
583
Laszlo Ersek353a06b2020-09-08 19:21:11 +0200584 |qemu_system| \\
585 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\
586 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000587 -drive file=/dev/fdset/2,index=0,media=disk
588ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100589
590DEF("set", HAS_ARG, QEMU_OPTION_set,
591 "-set group.id.arg=value\n"
592 " set <arg> parameter for item <id> of type <group>\n"
593 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000594SRST
595``-set group.id.arg=value``
596 Set parameter arg for item id of type group
597ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100598
599DEF("global", HAS_ARG, QEMU_OPTION_global,
Paolo Bonzini3751d7c2015-04-09 14:16:19 +0200600 "-global driver.property=value\n"
601 "-global driver=driver,property=property,value=value\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100602 " set a global default for a driver property\n",
603 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000604SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000605``-global driver.prop=value``
606 \
607``-global driver=driver,property=property,value=value``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000608 Set default value of driver's property prop to value, e.g.:
609
610 .. parsed-literal::
611
612 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img
613
614 In particular, you can use this to set driver properties for devices
615 which are created automatically by the machine model. To create a
616 device which is not created automatically and set properties on it,
617 use -``device``.
618
619 -global driver.prop=value is shorthand for -global
620 driver=driver,property=prop,value=value. The longhand syntax works
621 even when driver contains a dot.
622ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100623
624DEF("boot", HAS_ARG, QEMU_OPTION_boot,
625 "-boot [order=drives][,once=drives][,menu=on|off]\n"
Amos Kongc8a6ae82013-03-19 14:23:27 +0800626 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100627 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
628 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
629 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
630 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
631 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000632SRST
633``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]``
634 Specify boot order drives as a string of drive letters. Valid drive
635 letters depend on the target architecture. The x86 PC uses: a, b
636 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p
637 (Etherboot from network adapter 1-4), hard disk boot is the default.
638 To apply a particular boot order only on the first startup, specify
639 it via ``once``. Note that the ``order`` or ``once`` parameter
640 should not be used together with the ``bootindex`` property of
641 devices, since the firmware implementations normally do not support
642 both at the same time.
643
644 Interactive boot menus/prompts can be enabled via ``menu=on`` as far
645 as firmware/BIOS supports them. The default is non-interactive boot.
646
647 A splash picture could be passed to bios, enabling user to show it
648 as logo, when option splash=sp\_name is given and menu=on, If
649 firmware/BIOS supports them. Currently Seabios for X86 system
650 support it. limitation: The splash file could be a jpeg file or a
651 BMP file in 24 BPP format(true color). The resolution should be
652 supported by the SVGA mode, so the recommended is 320x240, 640x480,
653 800x640.
654
655 A timeout could be passed to bios, guest will pause for rb\_timeout
656 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will
657 not reboot, qemu passes '-1' to bios by default. Currently Seabios
658 for X86 system support it.
659
660 Do strict boot via ``strict=on`` as far as firmware/BIOS supports
661 it. This only effects when boot priority is changed by bootindex
662 options. The default is non-strict boot.
663
Peter Maydell09ce5f22020-02-28 15:36:13 +0000664 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000665
666 # try to boot from network first, then from hard disk
667 |qemu_system_x86| -boot order=nc
668 # boot from CD-ROM first, switch back to default order after reboot
669 |qemu_system_x86| -boot once=d
670 # boot with a splash picture for 5 seconds.
671 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000
672
673 Note: The legacy format '-boot drives' is still supported but its
674 use is discouraged as it may be removed from future versions.
675ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100676
677DEF("m", HAS_ARG, QEMU_OPTION_m,
Michael Tokarev89f3ea22016-11-10 17:51:32 +0300678 "-m [size=]megs[,slots=n,maxmem=size]\n"
Igor Mammedov6e1d3c12013-11-27 01:27:35 +0100679 " configure guest RAM\n"
Alexander Graf0daba1f2015-06-05 11:05:03 +0200680 " size: initial amount of guest memory\n"
Igor Mammedovc270fb92014-06-02 15:25:02 +0200681 " slots: number of hotplug slots (default: none)\n"
Matthew Rosatob6fe0122014-08-28 11:25:33 -0400682 " maxmem: maximum amount of guest memory (default: none)\n"
Thomas Hutha635bcf2023-07-03 09:56:46 +0200683 " Note: Some architectures might enforce a specific granularity\n",
Igor Mammedov6e1d3c12013-11-27 01:27:35 +0100684 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000685SRST
686``-m [size=]megs[,slots=n,maxmem=size]``
687 Sets guest startup RAM size to megs megabytes. Default is 128 MiB.
688 Optionally, a suffix of "M" or "G" can be used to signify a value in
689 megabytes or gigabytes respectively. Optional pair slots, maxmem
690 could be used to set amount of hotpluggable memory slots and maximum
691 amount of memory. Note that maxmem must be aligned to the page size.
692
693 For example, the following command-line sets the guest startup RAM
694 size to 1GB, creates 3 slots to hotplug additional memory and sets
695 the maximum memory the guest can reach to 4GB:
696
697 .. parsed-literal::
698
699 |qemu_system| -m 1G,slots=3,maxmem=4G
700
701 If slots and maxmem are not specified, memory hotplug won't be
702 enabled and the guest startup RAM will never increase.
703ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100704
705DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
706 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000707SRST
708``-mem-path path``
709 Allocate guest RAM from a temporarily created file in path.
710ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100711
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100712DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
713 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
714 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000715SRST
716``-mem-prealloc``
717 Preallocate memory when using -mem-path.
718ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100719
720DEF("k", HAS_ARG, QEMU_OPTION_k,
721 "-k language use keyboard layout (for example 'fr' for French)\n",
722 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000723SRST
724``-k language``
725 Use keyboard layout language (for example ``fr`` for French). This
726 option is only needed where it is not easy to get raw PC keycodes
727 (e.g. on Macs, with some X11 servers or with a VNC or curses
728 display). You don't normally need to use it on PC/Linux or
729 PC/Windows hosts.
730
731 The available layouts are:
732
733 ::
734
735 ar de-ch es fo fr-ca hu ja mk no pt-br sv
736 da en-gb et fr fr-ch is lt nl pl ru th
737 de en-us fi fr-be hr it lv nl-be pt sl tr
738
739 The default is ``en-us``.
740ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100741
742
Paolo Bonzini039a6832022-04-27 12:27:46 +0200743DEF("audio", HAS_ARG, QEMU_OPTION_audio,
Paolo Bonzini1ebdbff2023-09-21 10:23:58 +0200744 "-audio [driver=]driver[,prop[=value][,...]]\n"
745 " specifies default audio backend when `audiodev` is not\n"
746 " used to create a machine or sound device;"
747 " options are the same as for -audiodev\n"
Paolo Bonzini039a6832022-04-27 12:27:46 +0200748 "-audio [driver=]driver,model=value[,prop[=value][,...]]\n"
749 " specifies the audio backend and device to use;\n"
750 " apart from 'model', options are the same as for -audiodev.\n"
751 " use '-audio model=help' to show possible devices.\n",
752 QEMU_ARCH_ALL)
753SRST
Paolo Bonzini1ebdbff2023-09-21 10:23:58 +0200754``-audio [driver=]driver[,model=value][,prop[=value][,...]]``
755 If the ``model`` option is specified, ``-audio`` is a shortcut
756 for configuring both the guest audio hardware and the host audio
757 backend in one go. The guest hardware model can be set with
758 ``model=modelname``. Use ``model=help`` to list the available
759 device types.
Paolo Bonzini039a6832022-04-27 12:27:46 +0200760
761 The following two example do exactly the same, to show how ``-audio``
762 can be used to shorten the command line length:
763
764 .. parsed-literal::
765
766 |qemu_system| -audiodev pa,id=pa -device sb16,audiodev=pa
767 |qemu_system| -audio pa,model=sb16
Paolo Bonzini1ebdbff2023-09-21 10:23:58 +0200768
769 If the ``model`` option is not specified, ``-audio`` is used to
770 configure a default audio backend that will be used whenever the
771 ``audiodev`` property is not set on a device or machine. In
772 particular, ``-audio none`` ensures that no audio is produced even
773 for machines that have embedded sound hardware.
774
775 In both cases, the driver option is the same as with the corresponding
776 ``-audiodev`` option below. Use ``driver=help`` to list the available
777 drivers.
778
Paolo Bonzini039a6832022-04-27 12:27:46 +0200779ERST
780
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100781DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev,
782 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n"
783 " specifies the audio backend to use\n"
Claudio Fontana5e03b6d2022-09-08 10:14:41 +0200784 " Use ``-audiodev help`` to list the available drivers\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100785 " id= identifier of the backend\n"
786 " timer-period= timer period in microseconds\n"
Kővágó, Zoltán8efac072019-10-13 21:57:58 +0200787 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100788 " in|out.fixed-settings= use fixed settings for host audio\n"
789 " in|out.frequency= frequency to use with fixed settings\n"
790 " in|out.channels= number of channels to use with fixed settings\n"
791 " in|out.format= sample format to use with fixed settings\n"
Volker Rümelin49f77e62020-03-08 20:33:21 +0100792 " valid values: s8, s16, s32, u8, u16, u32, f32\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100793 " in|out.voices= number of voices to use\n"
Stefan Hajnoczi86247252019-09-18 10:53:33 +0100794 " in|out.buffer-length= length of buffer in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100795 "-audiodev none,id=id,[,prop[=value][,...]]\n"
796 " dummy driver that discards all output\n"
797#ifdef CONFIG_AUDIO_ALSA
798 "-audiodev alsa,id=id[,prop[=value][,...]]\n"
799 " in|out.dev= name of the audio device to use\n"
Stefan Hajnoczidfc54342019-09-18 10:53:35 +0100800 " in|out.period-length= length of period in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100801 " in|out.try-poll= attempt to use poll mode\n"
802 " threshold= threshold (in microseconds) when playback starts\n"
803#endif
804#ifdef CONFIG_AUDIO_COREAUDIO
805 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n"
806 " in|out.buffer-count= number of buffers\n"
807#endif
808#ifdef CONFIG_AUDIO_DSOUND
809 "-audiodev dsound,id=id[,prop[=value][,...]]\n"
810 " latency= add extra latency to playback in microseconds\n"
811#endif
812#ifdef CONFIG_AUDIO_OSS
813 "-audiodev oss,id=id[,prop[=value][,...]]\n"
814 " in|out.dev= path of the audio device to use\n"
815 " in|out.buffer-count= number of buffers\n"
816 " in|out.try-poll= attempt to use poll mode\n"
817 " try-mmap= try using memory mapped access\n"
818 " exclusive= open device in exclusive mode\n"
819 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n"
820#endif
821#ifdef CONFIG_AUDIO_PA
822 "-audiodev pa,id=id[,prop[=value][,...]]\n"
823 " server= PulseAudio server address\n"
824 " in|out.name= source/sink device name\n"
Stefan Hajnoczi14d4f012019-10-04 13:56:41 +0100825 " in|out.latency= desired latency in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100826#endif
Dorinda Basseyc2d3d1c2023-04-17 12:56:54 +0200827#ifdef CONFIG_AUDIO_PIPEWIRE
828 "-audiodev pipewire,id=id[,prop[=value][,...]]\n"
829 " in|out.name= source/sink device name\n"
830 " in|out.stream-name= name of pipewire stream\n"
831 " in|out.latency= desired latency in microseconds\n"
832#endif
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100833#ifdef CONFIG_AUDIO_SDL
834 "-audiodev sdl,id=id[,prop[=value][,...]]\n"
Volker Rümelin5a0926c2021-01-10 11:02:19 +0100835 " in|out.buffer-count= number of buffers\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100836#endif
Alexandre Ratchov663df1c2022-09-07 15:23:42 +0200837#ifdef CONFIG_AUDIO_SNDIO
838 "-audiodev sndio,id=id[,prop[=value][,...]]\n"
839#endif
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100840#ifdef CONFIG_SPICE
841 "-audiodev spice,id=id[,prop[=value][,...]]\n"
842#endif
Marc-André Lureau739362d2021-03-09 17:15:28 +0400843#ifdef CONFIG_DBUS_DISPLAY
844 "-audiodev dbus,id=id[,prop[=value][,...]]\n"
845#endif
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100846 "-audiodev wav,id=id[,prop[=value][,...]]\n"
847 " path= path of wav file to record\n",
848 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000849SRST
850``-audiodev [driver=]driver,id=id[,prop[=value][,...]]``
851 Adds a new audio backend driver identified by id. There are global
852 and driver specific properties. Some values can be set differently
853 for input and output, they're marked with ``in|out.``. You can set
854 the input's property with ``in.prop`` and the output's property with
855 ``out.prop``. For example:
856
857 ::
858
859 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000
860 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified
861
862 NOTE: parameter validation is known to be incomplete, in many cases
863 specifying an invalid option causes QEMU to print an error message
864 and continue emulation without sound.
865
866 Valid global options are:
867
868 ``id=identifier``
869 Identifies the audio backend.
870
871 ``timer-period=period``
872 Sets the timer period used by the audio subsystem in
873 microseconds. Default is 10000 (10 ms).
874
875 ``in|out.mixing-engine=on|off``
876 Use QEMU's mixing engine to mix all streams inside QEMU and
877 convert audio formats when not supported by the backend. When
878 off, fixed-settings must be off too. Note that disabling this
879 option means that the selected backend must support multiple
880 streams and the audio formats used by the virtual cards,
881 otherwise you'll get no sound. It's not recommended to disable
882 this option unless you want to use 5.1 or 7.1 audio, as mixing
883 engine only supports mono and stereo audio. Default is on.
884
885 ``in|out.fixed-settings=on|off``
886 Use fixed settings for host audio. When off, it will change
887 based on how the guest opens the sound card. In this case you
888 must not specify frequency, channels or format. Default is on.
889
890 ``in|out.frequency=frequency``
891 Specify the frequency to use when using fixed-settings. Default
892 is 44100Hz.
893
894 ``in|out.channels=channels``
895 Specify the number of channels to use when using fixed-settings.
896 Default is 2 (stereo).
897
898 ``in|out.format=format``
899 Specify the sample format to use when using fixed-settings.
900 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``,
Volker Rümelin49f77e62020-03-08 20:33:21 +0100901 ``u32``, ``f32``. Default is ``s16``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000902
903 ``in|out.voices=voices``
904 Specify the number of voices to use. Default is 1.
905
906 ``in|out.buffer-length=usecs``
907 Sets the size of the buffer in microseconds.
908
909``-audiodev none,id=id[,prop[=value][,...]]``
910 Creates a dummy backend that discards all outputs. This backend has
911 no backend specific properties.
912
913``-audiodev alsa,id=id[,prop[=value][,...]]``
914 Creates backend using the ALSA. This backend is only available on
915 Linux.
916
917 ALSA specific options are:
918
919 ``in|out.dev=device``
920 Specify the ALSA device to use for input and/or output. Default
921 is ``default``.
922
923 ``in|out.period-length=usecs``
924 Sets the period length in microseconds.
925
926 ``in|out.try-poll=on|off``
927 Attempt to use poll mode with the device. Default is on.
928
929 ``threshold=threshold``
930 Threshold (in microseconds) when playback starts. Default is 0.
931
932``-audiodev coreaudio,id=id[,prop[=value][,...]]``
933 Creates a backend using Apple's Core Audio. This backend is only
934 available on Mac OS and only supports playback.
935
936 Core Audio specific options are:
937
938 ``in|out.buffer-count=count``
939 Sets the count of the buffers.
940
941``-audiodev dsound,id=id[,prop[=value][,...]]``
942 Creates a backend using Microsoft's DirectSound. This backend is
943 only available on Windows and only supports playback.
944
945 DirectSound specific options are:
946
947 ``latency=usecs``
948 Add extra usecs microseconds latency to playback. Default is
949 10000 (10 ms).
950
951``-audiodev oss,id=id[,prop[=value][,...]]``
952 Creates a backend using OSS. This backend is available on most
953 Unix-like systems.
954
955 OSS specific options are:
956
957 ``in|out.dev=device``
958 Specify the file name of the OSS device to use. Default is
959 ``/dev/dsp``.
960
961 ``in|out.buffer-count=count``
962 Sets the count of the buffers.
963
964 ``in|out.try-poll=on|of``
965 Attempt to use poll mode with the device. Default is on.
966
967 ``try-mmap=on|off``
968 Try using memory mapped device access. Default is off.
969
970 ``exclusive=on|off``
971 Open the device in exclusive mode (vmix won't work in this
972 case). Default is off.
973
974 ``dsp-policy=policy``
975 Sets the timing policy (between 0 and 10, where smaller number
976 means smaller latency but higher CPU usage). Use -1 to use
977 buffer sizes specified by ``buffer`` and ``buffer-count``. This
978 option is ignored if you do not have OSS 4. Default is 5.
979
980``-audiodev pa,id=id[,prop[=value][,...]]``
981 Creates a backend using PulseAudio. This backend is available on
982 most systems.
983
984 PulseAudio specific options are:
985
986 ``server=server``
987 Sets the PulseAudio server to connect to.
988
989 ``in|out.name=sink``
990 Use the specified source/sink for recording/playback.
991
992 ``in|out.latency=usecs``
993 Desired latency in microseconds. The PulseAudio server will try
994 to honor this value but actual latencies may be lower or higher.
995
Dorinda Basseyc2d3d1c2023-04-17 12:56:54 +0200996``-audiodev pipewire,id=id[,prop[=value][,...]]``
Marc-André Lureau20c51242023-05-06 20:37:26 +0400997 Creates a backend using PipeWire. This backend is available on
Dorinda Basseyc2d3d1c2023-04-17 12:56:54 +0200998 most systems.
999
Marc-André Lureau20c51242023-05-06 20:37:26 +04001000 PipeWire specific options are:
Dorinda Basseyc2d3d1c2023-04-17 12:56:54 +02001001
1002 ``in|out.latency=usecs``
1003 Desired latency in microseconds.
1004
1005 ``in|out.name=sink``
1006 Use the specified source/sink for recording/playback.
1007
1008 ``in|out.stream-name``
1009 Specify the name of pipewire stream.
1010
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001011``-audiodev sdl,id=id[,prop[=value][,...]]``
1012 Creates a backend using SDL. This backend is available on most
1013 systems, but you should use your platform's native backend if
Volker Rümelin5a0926c2021-01-10 11:02:19 +01001014 possible.
1015
1016 SDL specific options are:
1017
1018 ``in|out.buffer-count=count``
1019 Sets the count of the buffers.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001020
Alexandre Ratchov663df1c2022-09-07 15:23:42 +02001021``-audiodev sndio,id=id[,prop[=value][,...]]``
1022 Creates a backend using SNDIO. This backend is available on
1023 OpenBSD and most other Unix-like systems.
1024
1025 Sndio specific options are:
1026
1027 ``in|out.dev=device``
1028 Specify the sndio device to use for input and/or output. Default
1029 is ``default``.
1030
1031 ``in|out.latency=usecs``
1032 Sets the desired period length in microseconds.
1033
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001034``-audiodev spice,id=id[,prop[=value][,...]]``
1035 Creates a backend that sends audio through SPICE. This backend
1036 requires ``-spice`` and automatically selected in that case, so
1037 usually you can ignore this option. This backend has no backend
1038 specific properties.
1039
1040``-audiodev wav,id=id[,prop[=value][,...]]``
1041 Creates a backend that writes audio to a WAV file.
1042
1043 Backend specific options are:
1044
1045 ``path=path``
1046 Write recorded audio into the specified file. Default is
1047 ``qemu.wav``.
1048ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001049
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001050DEF("device", HAS_ARG, QEMU_OPTION_device,
1051 "-device driver[,prop[=value][,...]]\n"
1052 " add device (based on driver)\n"
1053 " prop=value,... sets driver properties\n"
1054 " use '-device help' to print all possible drivers\n"
1055 " use '-device driver,help' to print all possible properties\n",
1056 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001057SRST
1058``-device driver[,prop[=value][,...]]``
1059 Add device driver. prop=value sets driver properties. Valid
1060 properties depend on the driver. To get help on possible drivers and
1061 properties, use ``-device help`` and ``-device driver,help``.
1062
1063 Some drivers are:
1064
Corey Minyard789101b2020-07-17 11:37:02 -05001065``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001066 Add an IPMI BMC. This is a simulation of a hardware management
1067 interface processor that normally sits on a system. It provides a
1068 watchdog and the ability to reset and power control the system. You
1069 need to connect this to an IPMI interface to make it useful
1070
1071 The IPMI slave address to use for the BMC. The default is 0x20. This
1072 address is the BMC's address on the I2C network of management
1073 controllers. If you don't know what this means, it is safe to ignore
1074 it.
1075
1076 ``id=id``
1077 The BMC id for interfaces to use this device.
1078
1079 ``slave_addr=val``
1080 Define slave address to use for the BMC. The default is 0x20.
1081
1082 ``sdrfile=file``
1083 file containing raw Sensor Data Records (SDR) data. The default
1084 is none.
1085
1086 ``fruareasize=val``
1087 size of a Field Replaceable Unit (FRU) area. The default is
1088 1024.
1089
1090 ``frudatafile=file``
1091 file containing raw Field Replaceable Unit (FRU) inventory data.
1092 The default is none.
1093
1094 ``guid=uuid``
1095 value for the GUID for the BMC, in standard UUID format. If this
1096 is set, get "Get GUID" command to the BMC will return it.
1097 Otherwise "Get GUID" will return an error.
1098
1099``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]``
1100 Add a connection to an external IPMI BMC simulator. Instead of
1101 locally emulating the BMC like the above item, instead connect to an
1102 external entity that provides the IPMI services.
1103
1104 A connection is made to an external BMC simulator. If you do this,
Daniil Tatianin96e610b2024-10-25 10:35:25 +03001105 it is strongly recommended that you use the "reconnect-ms=" chardev
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001106 option to reconnect to the simulator if the connection is lost. Note
1107 that if this is not used carefully, it can be a security issue, as
1108 the interface has the ability to send resets, NMIs, and power off
1109 the VM. It's best if QEMU makes a connection to an external
1110 simulator running on a secure port on localhost, so neither the
1111 simulator nor QEMU is exposed to any outside network.
1112
1113 See the "lanserv/README.vm" file in the OpenIPMI library for more
1114 details on the external interface.
1115
1116``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]``
Stefan Weil1e458f12022-10-30 11:59:44 +01001117 Add a KCS IPMI interface on the ISA bus. This also adds a
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001118 corresponding ACPI and SMBIOS entries, if appropriate.
1119
1120 ``bmc=id``
1121 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern
1122 above.
1123
1124 ``ioport=val``
1125 Define the I/O address of the interface. The default is 0xca0
1126 for KCS.
1127
1128 ``irq=val``
1129 Define the interrupt to use. The default is 5. To disable
1130 interrupts, set this to 0.
1131
1132``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]``
1133 Like the KCS interface, but defines a BT interface. The default port
1134 is 0xe4 and the default interrupt is 5.
Corey Minyard323679d2019-09-23 13:50:33 -05001135
1136``-device pci-ipmi-kcs,bmc=id``
Stefan Weil1e458f12022-10-30 11:59:44 +01001137 Add a KCS IPMI interface on the PCI bus.
Corey Minyard323679d2019-09-23 13:50:33 -05001138
1139 ``bmc=id``
1140 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
1141
1142``-device pci-ipmi-bt,bmc=id``
1143 Like the KCS interface, but defines a BT interface on the PCI bus.
Peter Xu7395b3e2021-07-07 11:41:14 -04001144
1145``-device intel-iommu[,option=...]``
1146 This is only supported by ``-machine q35``, which will enable Intel VT-d
1147 emulation within the guest. It supports below options:
1148
1149 ``intremap=on|off`` (default: auto)
1150 This enables interrupt remapping feature. It's required to enable
1151 complete x2apic. Currently it only supports kvm kernel-irqchip modes
1152 ``off`` or ``split``, while full kernel-irqchip is not yet supported.
1153 The default value is "auto", which will be decided by the mode of
1154 kernel-irqchip.
1155
1156 ``caching-mode=on|off`` (default: off)
1157 This enables caching mode for the VT-d emulated device. When
1158 caching-mode is enabled, each guest DMA buffer mapping will generate an
1159 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in
1160 a synchronous way. It is required for ``-device vfio-pci`` to work
1161 with the VT-d device, because host assigned devices requires to setup
1162 the DMA mapping on the host before guest DMA starts.
1163
1164 ``device-iotlb=on|off`` (default: off)
1165 This enables device-iotlb capability for the emulated VT-d device. So
1166 far virtio/vhost should be the only real user for this parameter,
1167 paired with ats=on configured for the device.
1168
1169 ``aw-bits=39|48`` (default: 39)
1170 This decides the address width of IOVA address space. The address
1171 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for
1172 4-level IOMMU page tables.
1173
1174 Please also refer to the wiki page for general scenarios of VT-d
1175 emulation in QEMU: https://wiki.qemu.org/Features/VT-d.
1176
Eric Auger69501292024-03-07 14:43:05 +01001177``-device virtio-iommu-pci[,option=...]``
1178 This is only supported by ``-machine q35`` (x86_64) and ``-machine virt`` (ARM).
1179 It supports below options:
1180
1181 ``granule=val`` (possible values are 4k, 8k, 16k, 64k and host; default: host)
1182 This decides the default granule to be be exposed by the
1183 virtio-iommu. If host, the granule matches the host page size.
1184
Eric Augerf7ada752024-03-07 14:43:10 +01001185 ``aw-bits=val`` (val between 32 and 64, default depends on machine)
1186 This decides the address width of the IOVA address space.
1187
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001188ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001189
1190DEF("name", HAS_ARG, QEMU_OPTION_name,
Dr. David Alan Gilbert8f480de2014-01-30 10:20:31 +00001191 "-name string1[,process=string2][,debug-threads=on|off]\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001192 " set the name of the guest\n"
Roman Bolshakov479a5742018-12-17 23:26:01 +03001193 " string1 sets the window title and string2 the process name\n"
1194 " When debug-threads is enabled, individual threads are given a separate name\n"
Dr. David Alan Gilbert8f480de2014-01-30 10:20:31 +00001195 " NOTE: The thread names are for debugging and not a stable API.\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001196 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001197SRST
1198``-name name``
1199 Sets the name of the guest. This name will be displayed in the SDL
1200 window caption. The name will also be used for the VNC server. Also
1201 optionally set the top visible process name in Linux. Naming of
1202 individual threads can also be enabled on Linux to aid debugging.
1203ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001204
1205DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
1206 "-uuid %08x-%04x-%04x-%04x-%012x\n"
1207 " specify machine UUID\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001208SRST
1209``-uuid uuid``
1210 Set system UUID.
1211ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001212
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001213DEFHEADING()
1214
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02001215DEFHEADING(Block device options:)
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001216
Alex Bennée5af2b0f2022-08-22 17:56:08 +01001217SRST
1218The QEMU block device handling options have a long history and
1219have gone through several iterations as the feature set and complexity
1220of the block layer have grown. Many online guides to QEMU often
1221reference older and deprecated options, which can lead to confusion.
1222
Alex Bennéec1654c32023-04-24 10:22:37 +01001223The most explicit way to describe disks is to use a combination of
Alex Bennée5af2b0f2022-08-22 17:56:08 +01001224``-device`` to specify the hardware device and ``-blockdev`` to
1225describe the backend. The device defines what the guest sees and the
Alex Bennéec1654c32023-04-24 10:22:37 +01001226backend describes how QEMU handles the data. It is the only guaranteed
1227stable interface for describing block devices and as such is
1228recommended for management tools and scripting.
1229
1230The ``-drive`` option combines the device and backend into a single
1231command line option which is a more human friendly. There is however no
1232interface stability guarantee although some older board models still
1233need updating to work with the modern blockdev forms.
1234
1235Older options like ``-hda`` are essentially macros which expand into
1236``-drive`` options for various drive interfaces. The original forms
1237bake in a lot of assumptions from the days when QEMU was emulating a
1238legacy PC, they are not recommended for modern configurations.
Alex Bennée5af2b0f2022-08-22 17:56:08 +01001239
1240ERST
1241
blueswir15824d652009-03-28 06:44:27 +00001242DEF("fda", HAS_ARG, QEMU_OPTION_fda,
Blue Swirlad960902010-03-29 19:23:52 +00001243 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
1244DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001245SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00001246``-fda file``
1247 \
1248``-fdb file``
Thomas Huth923e9312020-11-16 15:47:36 +01001249 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in
1250 the System Emulation Users Guide).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001251ERST
blueswir15824d652009-03-28 06:44:27 +00001252
1253DEF("hda", HAS_ARG, QEMU_OPTION_hda,
Thomas Huthbcd8e242023-08-29 15:29:48 +02001254 "-hda/-hdb file use 'file' as hard disk 0/1 image\n", QEMU_ARCH_ALL)
Blue Swirlad960902010-03-29 19:23:52 +00001255DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00001256DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
Thomas Huthbcd8e242023-08-29 15:29:48 +02001257 "-hdc/-hdd file use 'file' as hard disk 2/3 image\n", QEMU_ARCH_ALL)
Blue Swirlad960902010-03-29 19:23:52 +00001258DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001259SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00001260``-hda file``
1261 \
1262``-hdb file``
1263 \
1264``-hdc file``
1265 \
1266``-hdd file``
Thomas Huthbcd8e242023-08-29 15:29:48 +02001267 Use file as hard disk 0, 1, 2 or 3 image on the default bus of the
1268 emulated machine (this is for example the IDE bus on most x86 machines,
1269 but it can also be SCSI, virtio or something else on other target
1270 architectures). See also the :ref:`disk images` chapter in the System
1271 Emulation Users Guide.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001272ERST
blueswir15824d652009-03-28 06:44:27 +00001273
1274DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
Thomas Huthbcd8e242023-08-29 15:29:48 +02001275 "-cdrom file use 'file' as CD-ROM image\n",
Blue Swirlad960902010-03-29 19:23:52 +00001276 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001277SRST
1278``-cdrom file``
Thomas Huthbcd8e242023-08-29 15:29:48 +02001279 Use file as CD-ROM image on the default bus of the emulated machine
1280 (which is IDE1 master on x86, so you cannot use ``-hdc`` and ``-cdrom``
1281 at the same time there). On systems that support it, you can use the
1282 host CD-ROM by using ``/dev/cdrom`` as filename.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001283ERST
blueswir15824d652009-03-28 06:44:27 +00001284
Markus Armbruster42e5f392017-02-28 22:27:07 +01001285DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
1286 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
1287 " [,cache.direct=on|off][,cache.no-flush=on|off]\n"
Kevin Wolfc9b749d2019-10-15 12:29:58 +02001288 " [,read-only=on|off][,auto-read-only=on|off]\n"
1289 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n"
Markus Armbruster42e5f392017-02-28 22:27:07 +01001290 " [,driver specific parameters...]\n"
1291 " configure a block backend\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001292SRST
1293``-blockdev option[,option[,option[,...]]]``
1294 Define a new block driver node. Some of the options apply to all
1295 block drivers, other options are only accepted for a specific block
1296 driver. See below for a list of generic options and options for the
1297 most common block drivers.
1298
1299 Options that expect a reference to another node (e.g. ``file``) can
1300 be given in two ways. Either you specify the node name of an already
1301 existing node (file=node-name), or you define a new node inline,
1302 adding options for the referenced node after a dot
1303 (file.filename=path,file.aio=native).
1304
1305 A block driver node created with ``-blockdev`` can be used for a
1306 guest device by specifying its node name for the ``drive`` property
1307 in a ``-device`` argument that defines a block device.
1308
1309 ``Valid options for any block driver node:``
1310 ``driver``
1311 Specifies the block driver to use for the given node.
1312
1313 ``node-name``
1314 This defines the name of the block driver node by which it
1315 will be referenced later. The name must be unique, i.e. it
1316 must not match the name of a different block driver node, or
1317 (if you use ``-drive`` as well) the ID of a drive.
1318
1319 If no node name is specified, it is automatically generated.
1320 The generated node name is not intended to be predictable
1321 and changes between QEMU invocations. For the top level, an
1322 explicit node name must be specified.
1323
1324 ``read-only``
1325 Open the node read-only. Guest write attempts will fail.
1326
1327 Note that some block drivers support only read-only access,
1328 either generally or in certain configurations. In this case,
1329 the default value ``read-only=off`` does not work and the
1330 option must be specified explicitly.
1331
1332 ``auto-read-only``
1333 If ``auto-read-only=on`` is set, QEMU may fall back to
1334 read-only usage even when ``read-only=off`` is requested, or
1335 even switch between modes as needed, e.g. depending on
1336 whether the image file is writable or whether a writing user
1337 is attached to the node.
1338
1339 ``force-share``
1340 Override the image locking system of QEMU by forcing the
1341 node to utilize weaker shared access for permissions where
1342 it would normally request exclusive access. When there is
1343 the potential for multiple instances to have the same file
1344 open (whether this invocation of QEMU is the first or the
1345 second instance), both instances must permit shared access
1346 for the second instance to succeed at opening the file.
1347
1348 Enabling ``force-share=on`` requires ``read-only=on``.
1349
1350 ``cache.direct``
1351 The host page cache can be avoided with ``cache.direct=on``.
1352 This will attempt to do disk IO directly to the guest's
1353 memory. QEMU may still perform an internal copy of the data.
1354
1355 ``cache.no-flush``
1356 In case you don't care about data integrity over host
1357 failures, you can use ``cache.no-flush=on``. This option
1358 tells QEMU that it never needs to write any data to the disk
1359 but can instead keep things in cache. If anything goes
1360 wrong, like your host losing power, the disk storage getting
1361 disconnected accidentally, etc. your image will most
1362 probably be rendered unusable.
1363
1364 ``discard=discard``
1365 discard is one of "ignore" (or "off") or "unmap" (or "on")
1366 and controls whether ``discard`` (also known as ``trim`` or
1367 ``unmap``) requests are ignored or passed to the filesystem.
1368 Some machine types may not support discard requests.
1369
1370 ``detect-zeroes=detect-zeroes``
1371 detect-zeroes is "off", "on" or "unmap" and enables the
1372 automatic conversion of plain zero writes by the OS to
1373 driver specific optimized zero write commands. You may even
1374 choose "unmap" if discard is set to "unmap" to allow a zero
1375 write to be converted to an ``unmap`` operation.
1376
1377 ``Driver-specific options for file``
1378 This is the protocol-level block driver for accessing regular
1379 files.
1380
1381 ``filename``
1382 The path to the image file in the local filesystem
1383
1384 ``aio``
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001385 Specifies the AIO backend (threads/native/io_uring,
1386 default: threads)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001387
1388 ``locking``
1389 Specifies whether the image file is protected with Linux OFD
1390 / POSIX locks. The default is to use the Linux Open File
1391 Descriptor API if available, otherwise no lock is applied.
1392 (auto/on/off, default: auto)
1393
1394 Example:
1395
1396 ::
1397
1398 -blockdev driver=file,node-name=disk,filename=disk.img
1399
1400 ``Driver-specific options for raw``
1401 This is the image format block driver for raw images. It is
1402 usually stacked on top of a protocol level block driver such as
1403 ``file``.
1404
1405 ``file``
1406 Reference to or definition of the data source block driver
1407 node (e.g. a ``file`` driver node)
1408
1409 Example 1:
1410
1411 ::
1412
1413 -blockdev driver=file,node-name=disk_file,filename=disk.img
1414 -blockdev driver=raw,node-name=disk,file=disk_file
1415
1416 Example 2:
1417
1418 ::
1419
1420 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
1421
1422 ``Driver-specific options for qcow2``
1423 This is the image format block driver for qcow2 images. It is
1424 usually stacked on top of a protocol level block driver such as
1425 ``file``.
1426
1427 ``file``
1428 Reference to or definition of the data source block driver
1429 node (e.g. a ``file`` driver node)
1430
1431 ``backing``
1432 Reference to or definition of the backing file block device
1433 (default is taken from the image file). It is allowed to
1434 pass ``null`` here in order to disable the default backing
1435 file.
1436
1437 ``lazy-refcounts``
1438 Whether to enable the lazy refcounts feature (on/off;
1439 default is taken from the image file)
1440
1441 ``cache-size``
1442 The maximum total size of the L2 table and refcount block
1443 caches in bytes (default: the sum of l2-cache-size and
1444 refcount-cache-size)
1445
1446 ``l2-cache-size``
1447 The maximum size of the L2 table cache in bytes (default: if
1448 cache-size is not specified - 32M on Linux platforms, and 8M
1449 on non-Linux platforms; otherwise, as large as possible
1450 within the cache-size, while permitting the requested or the
1451 minimal refcount cache size)
1452
1453 ``refcount-cache-size``
1454 The maximum size of the refcount block cache in bytes
1455 (default: 4 times the cluster size; or if cache-size is
1456 specified, the part of it which is not used for the L2
1457 cache)
1458
1459 ``cache-clean-interval``
1460 Clean unused entries in the L2 and refcount caches. The
1461 interval is in seconds. The default value is 600 on
1462 supporting platforms, and 0 on other platforms. Setting it
1463 to 0 disables this feature.
1464
1465 ``pass-discard-request``
1466 Whether discard requests to the qcow2 device should be
1467 forwarded to the data source (on/off; default: on if
1468 discard=unmap is specified, off otherwise)
1469
1470 ``pass-discard-snapshot``
1471 Whether discard requests for the data source should be
1472 issued when a snapshot operation (e.g. deleting a snapshot)
1473 frees clusters in the qcow2 file (on/off; default: on)
1474
1475 ``pass-discard-other``
1476 Whether discard requests for the data source should be
1477 issued on other occasions where a cluster gets freed
1478 (on/off; default: off)
1479
Jean-Louis Dupond42a28902023-06-05 10:45:24 +02001480 ``discard-no-unref``
Jean-Louis Dupondb2b10902023-10-03 14:52:37 +02001481 When enabled, data clusters will remain preallocated when they are
1482 no longer used, e.g. because they are discarded or converted to
1483 zero clusters. As usual, whether the old data is discarded or kept
1484 on the protocol level (i.e. in the image file) depends on the
1485 setting of the pass-discard-request option. Keeping the clusters
1486 preallocated prevents qcow2 fragmentation that would otherwise be
1487 caused by freeing and re-allocating them later. Besides potential
Jean-Louis Dupond42a28902023-06-05 10:45:24 +02001488 performance degradation, such fragmentation can lead to increased
1489 allocation of clusters past the end of the image file,
1490 resulting in image files whose file length can grow much larger
1491 than their guest disk size would suggest.
1492 If image file length is of concern (e.g. when storing qcow2
1493 images directly on block devices), you should consider enabling
1494 this option.
1495
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001496 ``overlap-check``
1497 Which overlap checks to perform for writes to the image
1498 (none/constant/cached/all; default: cached). For details or
1499 finer granularity control refer to the QAPI documentation of
1500 ``blockdev-add``.
1501
1502 Example 1:
1503
1504 ::
1505
1506 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
1507 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
1508
1509 Example 2:
1510
1511 ::
1512
1513 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
1514
1515 ``Driver-specific options for other drivers``
1516 Please refer to the QAPI documentation of the ``blockdev-add``
1517 QMP command.
1518ERST
Markus Armbruster42e5f392017-02-28 22:27:07 +01001519
blueswir15824d652009-03-28 06:44:27 +00001520DEF("drive", HAS_ARG, QEMU_OPTION_drive,
1521 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
Stefan Hajnoczi92196b22011-08-04 12:26:52 +01001522 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
Kevin Wolf572023f2018-06-13 11:01:30 +02001523 " [,snapshot=on|off][,rerror=ignore|stop|report]\n"
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001524 " [,werror=ignore|stop|report|enospc][,id=name]\n"
1525 " [,aio=threads|native|io_uring]\n"
Stefan Hajnoczifb0490f2011-11-17 13:40:32 +00001526 " [,readonly=on|off][,copy-on-read=on|off]\n"
Peter Lieven2f7133b2014-07-28 21:53:02 +02001527 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
Benoît Canet3e9fab62013-09-02 14:14:40 +02001528 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
1529 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
1530 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
1531 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
Benoît Canet2024c1d2013-09-02 14:14:41 +02001532 " [[,iops_size=is]]\n"
Alberto Garcia76f4afb2015-06-08 18:17:44 +02001533 " [[,group=g]]\n"
Blue Swirlad960902010-03-29 19:23:52 +00001534 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001535SRST
1536``-drive option[,option[,option[,...]]]``
1537 Define a new drive. This includes creating a block driver node (the
1538 backend) as well as a guest device, and is mostly a shortcut for
1539 defining the corresponding ``-blockdev`` and ``-device`` options.
1540
1541 ``-drive`` accepts all options that are accepted by ``-blockdev``.
1542 In addition, it knows the following options:
1543
1544 ``file=file``
Thomas Huth923e9312020-11-16 15:47:36 +01001545 This option defines which disk image (see the :ref:`disk images`
1546 chapter in the System Emulation Users Guide) to use with this drive.
1547 If the filename contains comma, you must double it (for instance,
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001548 "file=my,,file" to use file "my,file").
1549
1550 Special files such as iSCSI devices can be specified using
1551 protocol specific URLs. See the section for "Device URL Syntax"
1552 for more information.
1553
1554 ``if=interface``
1555 This option defines on which type on interface the drive is
1556 connected. Available types are: ide, scsi, sd, mtd, floppy,
1557 pflash, virtio, none.
1558
1559 ``bus=bus,unit=unit``
1560 These options define where is connected the drive by defining
1561 the bus number and the unit id.
1562
1563 ``index=index``
Laurent Vivier35aab302022-02-02 15:34:22 +01001564 This option defines where the drive is connected by using an
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001565 index in the list of available connectors of a given interface
1566 type.
1567
1568 ``media=media``
1569 This option defines the type of the media: disk or cdrom.
1570
1571 ``snapshot=snapshot``
1572 snapshot is "on" or "off" and controls snapshot mode for the
1573 given drive (see ``-snapshot``).
1574
1575 ``cache=cache``
1576 cache is "none", "writeback", "unsafe", "directsync" or
1577 "writethrough" and controls how the host cache is used to access
1578 block data. This is a shortcut that sets the ``cache.direct``
1579 and ``cache.no-flush`` options (as in ``-blockdev``), and
1580 additionally ``cache.writeback``, which provides a default for
1581 the ``write-cache`` option of block guest devices (as in
1582 ``-device``). The modes correspond to the following settings:
1583
Peter Maydell09ce5f22020-02-28 15:36:13 +00001584 ============= =============== ============ ==============
1585 \ cache.writeback cache.direct cache.no-flush
1586 ============= =============== ============ ==============
1587 writeback on off off
1588 none on on off
1589 writethrough off off off
1590 directsync off on off
1591 unsafe on off on
1592 ============= =============== ============ ==============
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001593
1594 The default mode is ``cache=writeback``.
1595
1596 ``aio=aio``
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001597 aio is "threads", "native", or "io_uring" and selects between pthread
1598 based disk I/O, native Linux AIO, or Linux io_uring API.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001599
1600 ``format=format``
1601 Specify which disk format will be used rather than detecting the
1602 format. Can be used to specify format=raw to avoid interpreting
1603 an untrusted format header.
1604
1605 ``werror=action,rerror=action``
1606 Specify which action to take on write and read errors. Valid
1607 actions are: "ignore" (ignore the error and try to continue),
1608 "stop" (pause QEMU), "report" (report the error to the guest),
1609 "enospc" (pause QEMU only if the host disk is full; report the
1610 error to the guest otherwise). The default setting is
1611 ``werror=enospc`` and ``rerror=report``.
1612
1613 ``copy-on-read=copy-on-read``
1614 copy-on-read is "on" or "off" and enables whether to copy read
1615 backing file sectors into the image file.
1616
1617 ``bps=b,bps_rd=r,bps_wr=w``
1618 Specify bandwidth throttling limits in bytes per second, either
1619 for all request types or for reads or writes only. Small values
1620 can lead to timeouts or hangs inside the guest. A safe minimum
1621 for disks is 2 MB/s.
1622
1623 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm``
1624 Specify bursts in bytes per second, either for all request types
1625 or for reads or writes only. Bursts allow the guest I/O to spike
1626 above the limit temporarily.
1627
1628 ``iops=i,iops_rd=r,iops_wr=w``
1629 Specify request rate limits in requests per second, either for
1630 all request types or for reads or writes only.
1631
1632 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm``
1633 Specify bursts in requests per second, either for all request
1634 types or for reads or writes only. Bursts allow the guest I/O to
1635 spike above the limit temporarily.
1636
1637 ``iops_size=is``
1638 Let every is bytes of a request count as a new request for iops
1639 throttling purposes. Use this option to prevent guests from
1640 circumventing iops limits by sending fewer but larger requests.
1641
1642 ``group=g``
1643 Join a throttling quota group with given name g. All drives that
1644 are members of the same group are accounted for together. Use
1645 this option to prevent guests from circumventing throttling
1646 limits by using many small disks instead of a single larger
1647 disk.
1648
1649 By default, the ``cache.writeback=on`` mode is used. It will report
1650 data writes as completed as soon as the data is present in the host
1651 page cache. This is safe as long as your guest OS makes sure to
1652 correctly flush disk caches where needed. If your guest OS does not
1653 handle volatile disk write caches correctly and your host crashes or
1654 loses power, then the guest may experience data corruption.
1655
1656 For such guests, you should consider using ``cache.writeback=off``.
1657 This means that the host page cache will be used to read and write
1658 data, but write notification will be sent to the guest only after
1659 QEMU has made sure to flush each write to the disk. Be aware that
1660 this has a major impact on performance.
1661
1662 When using the ``-snapshot`` option, unsafe caching is always used.
1663
1664 Copy-on-read avoids accessing the same backing file sectors
1665 repeatedly and is useful when the backing file is over a slow
1666 network. By default copy-on-read is off.
1667
1668 Instead of ``-cdrom`` you can use:
1669
1670 .. parsed-literal::
1671
1672 |qemu_system| -drive file=file,index=2,media=cdrom
1673
1674 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use:
1675
1676 .. parsed-literal::
1677
1678 |qemu_system| -drive file=file,index=0,media=disk
1679 |qemu_system| -drive file=file,index=1,media=disk
1680 |qemu_system| -drive file=file,index=2,media=disk
1681 |qemu_system| -drive file=file,index=3,media=disk
1682
1683 You can open an image using pre-opened file descriptors from an fd
1684 set:
1685
1686 .. parsed-literal::
1687
Laszlo Ersek353a06b2020-09-08 19:21:11 +02001688 |qemu_system| \\
1689 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\
1690 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001691 -drive file=/dev/fdset/2,index=0,media=disk
1692
1693 You can connect a CDROM to the slave of ide0:
1694
1695 .. parsed-literal::
1696
1697 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom
1698
1699 If you don't specify the "file=" argument, you define an empty
1700 drive:
1701
1702 .. parsed-literal::
1703
1704 |qemu_system_x86| -drive if=ide,index=1,media=cdrom
1705
1706 Instead of ``-fda``, ``-fdb``, you can use:
1707
1708 .. parsed-literal::
1709
1710 |qemu_system_x86| -drive file=file,index=0,if=floppy
1711 |qemu_system_x86| -drive file=file,index=1,if=floppy
1712
1713 By default, interface is "ide" and index is automatically
1714 incremented:
1715
1716 .. parsed-literal::
1717
John Snowa234ec32023-02-02 17:31:21 -05001718 |qemu_system_x86| -drive file=a -drive file=b
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001719
1720 is interpreted like:
1721
1722 .. parsed-literal::
1723
1724 |qemu_system_x86| -hda a -hdb b
1725ERST
blueswir15824d652009-03-28 06:44:27 +00001726
1727DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
Blue Swirlad960902010-03-29 19:23:52 +00001728 "-mtdblock file use 'file' as on-board Flash memory image\n",
1729 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001730SRST
1731``-mtdblock file``
1732 Use file as on-board Flash memory image.
1733ERST
blueswir15824d652009-03-28 06:44:27 +00001734
1735DEF("sd", HAS_ARG, QEMU_OPTION_sd,
Blue Swirlad960902010-03-29 19:23:52 +00001736 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001737SRST
1738``-sd file``
1739 Use file as SecureDigital card image.
1740ERST
blueswir15824d652009-03-28 06:44:27 +00001741
blueswir15824d652009-03-28 06:44:27 +00001742DEF("snapshot", 0, QEMU_OPTION_snapshot,
Blue Swirlad960902010-03-29 19:23:52 +00001743 "-snapshot write to temporary files instead of disk image files\n",
1744 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001745SRST
1746``-snapshot``
1747 Write to temporary files instead of disk image files. In this case,
1748 the raw disk image you use is not written back. You can however
Thomas Huth923e9312020-11-16 15:47:36 +01001749 force the write back by pressing C-a s (see the :ref:`disk images`
1750 chapter in the System Emulation Users Guide).
Alex Bennéec1654c32023-04-24 10:22:37 +01001751
1752 .. warning::
1753 snapshot is incompatible with ``-blockdev`` (instead use qemu-img
1754 to manually create snapshot images to attach to your blockdev).
1755 If you have mixed ``-blockdev`` and ``-drive`` declarations you
1756 can use the 'snapshot' property on your drive declarations
1757 instead of this global option.
1758
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001759ERST
blueswir15824d652009-03-28 06:44:27 +00001760
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301761DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
Greg Kurzb44a6b02019-05-17 17:34:49 +02001762 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n"
Paolo Bonzini991c1802020-11-13 03:10:52 -05001763 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n"
Pradeep Jagadeeshb8bbdb82017-02-28 10:31:46 +01001764 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1765 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1766 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1767 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
Greg Kurzb44a6b02019-05-17 17:34:49 +02001768 " [[,throttling.iops-size=is]]\n"
Greg Kurzb44a6b02019-05-17 17:34:49 +02001769 "-fsdev synth,id=id\n",
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301770 QEMU_ARCH_ALL)
1771
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001772SRST
Paolo Bonzini991c1802020-11-13 03:10:52 -05001773``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly=on][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001774 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001775``-fsdev synth,id=id[,readonly=on]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001776 Define a new file system device. Valid options are:
1777
1778 ``local``
1779 Accesses to the filesystem are done by QEMU.
1780
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001781 ``synth``
1782 Synthetic filesystem, only used by QTests.
1783
1784 ``id=id``
1785 Specifies identifier for this device.
1786
1787 ``path=path``
1788 Specifies the export path for the file system device. Files
1789 under this path will be available to the 9p client on the guest.
1790
1791 ``security_model=security_model``
1792 Specifies the security model to be used for this export path.
1793 Supported security models are "passthrough", "mapped-xattr",
1794 "mapped-file" and "none". In "passthrough" security model, files
1795 are stored using the same credentials as they are created on the
1796 guest. This requires QEMU to run as root. In "mapped-xattr"
1797 security model, some of the file attributes like uid, gid, mode
1798 bits and link target are stored as file attributes. For
1799 "mapped-file" these attributes are stored in the hidden
1800 .virtfs\_metadata directory. Directories exported by this
1801 security model cannot interact with other unix tools. "none"
1802 security model is same as passthrough except the sever won't
1803 report failures if it fails to set file attributes like
1804 ownership. Security model is mandatory only for local fsdriver.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001805
1806 ``writeout=writeout``
1807 This is an optional argument. The only supported value is
1808 "immediate". This means that host page cache will be used to
1809 read and write data but write notification will be sent to the
1810 guest only when the data has been reported as written by the
1811 storage subsystem.
1812
Paolo Bonzini991c1802020-11-13 03:10:52 -05001813 ``readonly=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001814 Enables exporting 9p share as a readonly mount for guests. By
1815 default read-write access is given.
1816
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001817 ``fmode=fmode``
1818 Specifies the default mode for newly created files on the host.
1819 Works only with security models "mapped-xattr" and
1820 "mapped-file".
1821
1822 ``dmode=dmode``
1823 Specifies the default mode for newly created directories on the
1824 host. Works only with security models "mapped-xattr" and
1825 "mapped-file".
1826
1827 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w``
1828 Specify bandwidth throttling limits in bytes per second, either
1829 for all request types or for reads or writes only.
1830
1831 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm``
1832 Specify bursts in bytes per second, either for all request types
1833 or for reads or writes only. Bursts allow the guest I/O to spike
1834 above the limit temporarily.
1835
1836 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w``
1837 Specify request rate limits in requests per second, either for
1838 all request types or for reads or writes only.
1839
1840 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm``
1841 Specify bursts in requests per second, either for all request
1842 types or for reads or writes only. Bursts allow the guest I/O to
1843 spike above the limit temporarily.
1844
1845 ``throttling.iops-size=is``
1846 Let every is bytes of a request count as a new request for iops
1847 throttling purposes.
1848
1849 -fsdev option is used along with -device driver "virtio-9p-...".
1850
1851``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag``
1852 Options for virtio-9p-... driver are:
1853
1854 ``type``
1855 Specifies the variant to be used. Supported values are "pci",
1856 "ccw" or "device", depending on the machine type.
1857
1858 ``fsdev=id``
1859 Specifies the id value specified along with -fsdev option.
1860
1861 ``mount_tag=mount_tag``
1862 Specifies the tag name to be used by the guest to mount this
1863 export point.
1864ERST
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301865
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301866DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
Greg Kurzb44a6b02019-05-17 17:34:49 +02001867 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n"
Paolo Bonzini991c1802020-11-13 03:10:52 -05001868 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n"
Paolo Bonzini991c1802020-11-13 03:10:52 -05001869 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n",
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301870 QEMU_ARCH_ALL)
1871
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001872SRST
Paolo Bonzini991c1802020-11-13 03:10:52 -05001873``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly=on] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001874 \
Peter Maydell09ce5f22020-02-28 15:36:13 +00001875``-virtfs synth,mount_tag=mount_tag``
Christian Schoenebeck65abaa02020-05-14 08:06:43 +02001876 Define a new virtual filesystem device and expose it to the guest using
1877 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain
1878 directory on host is made directly accessible by guest as a pass-through
1879 file system by using the 9P network protocol for communication between
1880 host and guests, if desired even accessible, shared by several guests
Stefan Weil2cb40d42022-11-10 20:08:25 +01001881 simultaneously.
Christian Schoenebeck65abaa02020-05-14 08:06:43 +02001882
1883 Note that ``-virtfs`` is actually just a convenience shortcut for its
1884 generalized form ``-fsdev -device virtio-9p-pci``.
1885
1886 The general form of pass-through file system options are:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001887
1888 ``local``
1889 Accesses to the filesystem are done by QEMU.
1890
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001891 ``synth``
1892 Synthetic filesystem, only used by QTests.
1893
1894 ``id=id``
1895 Specifies identifier for the filesystem device
1896
1897 ``path=path``
1898 Specifies the export path for the file system device. Files
1899 under this path will be available to the 9p client on the guest.
1900
1901 ``security_model=security_model``
1902 Specifies the security model to be used for this export path.
1903 Supported security models are "passthrough", "mapped-xattr",
1904 "mapped-file" and "none". In "passthrough" security model, files
1905 are stored using the same credentials as they are created on the
1906 guest. This requires QEMU to run as root. In "mapped-xattr"
1907 security model, some of the file attributes like uid, gid, mode
1908 bits and link target are stored as file attributes. For
1909 "mapped-file" these attributes are stored in the hidden
1910 .virtfs\_metadata directory. Directories exported by this
1911 security model cannot interact with other unix tools. "none"
1912 security model is same as passthrough except the sever won't
1913 report failures if it fails to set file attributes like
1914 ownership. Security model is mandatory only for local fsdriver.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001915
1916 ``writeout=writeout``
1917 This is an optional argument. The only supported value is
1918 "immediate". This means that host page cache will be used to
1919 read and write data but write notification will be sent to the
1920 guest only when the data has been reported as written by the
1921 storage subsystem.
1922
Paolo Bonzini991c1802020-11-13 03:10:52 -05001923 ``readonly=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001924 Enables exporting 9p share as a readonly mount for guests. By
1925 default read-write access is given.
1926
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001927 ``fmode=fmode``
1928 Specifies the default mode for newly created files on the host.
1929 Works only with security models "mapped-xattr" and
1930 "mapped-file".
1931
1932 ``dmode=dmode``
1933 Specifies the default mode for newly created directories on the
1934 host. Works only with security models "mapped-xattr" and
1935 "mapped-file".
1936
1937 ``mount_tag=mount_tag``
1938 Specifies the tag name to be used by the guest to mount this
1939 export point.
1940
1941 ``multidevs=multidevs``
1942 Specifies how to deal with multiple devices being shared with a
1943 9p export. Supported behaviours are either "remap", "forbid" or
1944 "warn". The latter is the default behaviour on which virtfs 9p
1945 expects only one device to be shared with the same export, and
1946 if more than one device is shared and accessed via the same 9p
1947 export then only a warning message is logged (once) by qemu on
1948 host side. In order to avoid file ID collisions on guest you
1949 should either create a separate virtfs export for each device to
1950 be shared with guests (recommended way) or you might use "remap"
1951 instead which allows you to share multiple devices with only one
1952 export instead, which is achieved by remapping the original
1953 inode numbers from host to guest in a way that would prevent
1954 such collisions. Remapping inodes in such use cases is required
1955 because the original device IDs from host are never passed and
1956 exposed on guest. Instead all files of an export shared with
1957 virtfs always share the same device id on guest. So two files
1958 with identical inode numbers but from actually different devices
1959 on host would otherwise cause a file ID collision and hence
1960 potential misbehaviours on guest. "forbid" on the other hand
1961 assumes like "warn" that only one device is shared by the same
1962 export, however it will not only log a warning message but also
1963 deny access to additional devices on guest. Note though that
1964 "forbid" does currently not block all possible file access
1965 operations (e.g. readdir() would still return entries from other
1966 devices).
1967ERST
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301968
Markus Armbruster61d70482017-10-02 16:03:03 +02001969DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
Daniel P. Berrangéc3b3a6c2022-12-01 04:25:05 -05001970 "-iscsi [user=user][,password=password][,password-secret=secret-id]\n"
1971 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE]\n"
Markus Armbruster61d70482017-10-02 16:03:03 +02001972 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1973 " [,timeout=timeout]\n"
1974 " iSCSI session parameters\n", QEMU_ARCH_ALL)
1975
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001976SRST
1977``-iscsi``
1978 Configure iSCSI session parameters.
1979ERST
Markus Armbruster44743142017-10-02 16:03:04 +02001980
blueswir15824d652009-03-28 06:44:27 +00001981DEFHEADING()
1982
Thomas Huthc2a34ab2021-03-10 18:33:23 +01001983DEFHEADING(USB convenience options:)
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001984
1985DEF("usb", 0, QEMU_OPTION_usb,
Stefan Hajnoczi73f46fe2019-08-15 15:14:28 +01001986 "-usb enable on-board USB host controller (if not enabled by default)\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001987 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001988SRST
1989``-usb``
1990 Enable USB emulation on machine types with an on-board USB host
1991 controller (if not enabled by default). Note that on-board USB host
1992 controllers may not support USB 3.0. In this case
1993 ``-device qemu-xhci`` can be used instead on machines with PCI.
1994ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001995
1996DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1997 "-usbdevice name add the host or guest USB device 'name'\n",
1998 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001999SRST
2000``-usbdevice devname``
Thomas Huthc2a34ab2021-03-10 18:33:23 +01002001 Add the USB device devname, and enable an on-board USB controller
2002 if possible and necessary (just like it can be done via
2003 ``-machine usb=on``). Note that this option is mainly intended for
2004 the user's convenience only. More fine-grained control can be
2005 achieved by selecting a USB host controller (if necessary) and the
2006 desired USB device via the ``-device`` option instead. For example,
2007 instead of using ``-usbdevice mouse`` it is possible to use
2008 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse
2009 to a USB 3.0 controller instead (at least on machines that support
2010 PCI and do not have an USB controller enabled by default yet).
2011 For more details, see the chapter about
Thomas Huth923e9312020-11-16 15:47:36 +01002012 :ref:`Connecting USB devices` in the System Emulation Users Guide.
Thomas Huthc2a34ab2021-03-10 18:33:23 +01002013 Possible devices for devname are:
2014
2015 ``braille``
2016 Braille device. This will use BrlAPI to display the braille
2017 output on a real or fake device (i.e. it also creates a
2018 corresponding ``braille`` chardev automatically beside the
2019 ``usb-braille`` USB device).
2020
Thomas Huthc2a34ab2021-03-10 18:33:23 +01002021 ``keyboard``
2022 Standard USB keyboard. Will override the PS/2 keyboard (if present).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002023
2024 ``mouse``
2025 Virtual Mouse. This will override the PS/2 mouse emulation when
2026 activated.
2027
2028 ``tablet``
2029 Pointer device that uses absolute coordinates (like a
2030 touchscreen). This means QEMU is able to report the mouse
2031 position without having to grab the mouse. Also overrides the
2032 PS/2 mouse emulation when activated.
2033
Thomas Huthc2a34ab2021-03-10 18:33:23 +01002034 ``wacom-tablet``
2035 Wacom PenPartner USB tablet.
2036
2037
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002038ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01002039
Markus Armbruster10adb8b2013-02-13 19:49:43 +01002040DEFHEADING()
2041
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002042DEFHEADING(Display options:)
blueswir15824d652009-03-28 06:44:27 +00002043
Jes Sorensen1472a952011-03-16 13:33:31 +01002044DEF("display", HAS_ARG, QEMU_OPTION_display,
Thomas Huth88b40c62019-10-23 14:01:28 +02002045#if defined(CONFIG_SPICE)
Marc-André Lureaud8aec9d2019-02-21 12:07:03 +01002046 "-display spice-app[,gl=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02002047#endif
2048#if defined(CONFIG_SDL)
Thomas Hutha743d602022-05-19 17:56:23 +02002049 "-display sdl[,gl=on|core|es|off][,grab-mod=<mod>][,show-cursor=on|off]\n"
2050 " [,window-close=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02002051#endif
Robert Hof04ec5a2016-07-26 18:17:11 +08002052#if defined(CONFIG_GTK)
Thomas Huth95f439b2021-06-30 18:32:31 +02002053 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n"
Felix xq Queißnerc34a9332022-07-12 15:37:53 +02002054 " [,show-tabs=on|off][,show-cursor=on|off][,window-close=on|off]\n"
BALATON Zoltane26c9402024-02-09 01:05:06 +01002055 " [,show-menubar=on|off][,zoom-to-fit=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02002056#endif
2057#if defined(CONFIG_VNC)
2058 "-display vnc=<display>[,<optargs>]\n"
2059#endif
2060#if defined(CONFIG_CURSES)
2061 "-display curses[,charset=<encoding>]\n"
2062#endif
Gustavo Noronha Silvaf844cdb2022-03-06 21:11:18 +09002063#if defined(CONFIG_COCOA)
Gustavo Noronha Silva4797adc2022-03-06 21:11:19 +09002064 "-display cocoa[,full-grab=on|off][,swap-opt-cmd=on|off]\n"
Akihiko Odaki9ab87152023-12-14 15:31:35 +09002065 " [,show-cursor=on|off][,left-command-key=on|off]\n"
Akihiko Odakid502dfc2023-12-14 15:31:36 +09002066 " [,full-screen=on|off][,zoom-to-fit=on|off]\n"
Gustavo Noronha Silvaf844cdb2022-03-06 21:11:18 +09002067#endif
Thomas Huth88b40c62019-10-23 14:01:28 +02002068#if defined(CONFIG_OPENGL)
2069 "-display egl-headless[,rendernode=<file>]\n"
2070#endif
Marc-André Lureau142ca622021-07-15 11:53:53 +04002071#if defined(CONFIG_DBUS_DISPLAY)
2072 "-display dbus[,addr=<dbusaddr>]\n"
2073 " [,gl=on|core|es|off][,rendernode=<file>]\n"
2074#endif
Thomas Huth88b40c62019-10-23 14:01:28 +02002075 "-display none\n"
2076 " select display backend type\n"
2077 " The default display is equivalent to\n "
2078#if defined(CONFIG_GTK)
2079 "\"-display gtk\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002080#elif defined(CONFIG_SDL)
Thomas Huth88b40c62019-10-23 14:01:28 +02002081 "\"-display sdl\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002082#elif defined(CONFIG_COCOA)
Thomas Huth88b40c62019-10-23 14:01:28 +02002083 "\"-display cocoa\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002084#elif defined(CONFIG_VNC)
Thomas Huth88b40c62019-10-23 14:01:28 +02002085 "\"-vnc localhost:0,to=99,id=default\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002086#else
Thomas Huth88b40c62019-10-23 14:01:28 +02002087 "\"-display none\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002088#endif
2089 , QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002090SRST
2091``-display type``
Thomas Huth707d93d2022-05-19 17:56:25 +02002092 Select type of display to use. Use ``-display help`` to list the available
2093 display types. Valid values for type are
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002094
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002095 ``spice-app[,gl=on|off]``
2096 Start QEMU as a Spice server and launch the default Spice client
2097 application. The Spice server will redirect the serial consoles
2098 and QEMU monitors. (Since 4.0)
2099
Marc-André Lureau142ca622021-07-15 11:53:53 +04002100 ``dbus``
2101 Export the display over D-Bus interfaces. (Since 7.0)
2102
2103 The connection is registered with the "org.qemu" name (and queued when
2104 already owned).
2105
2106 ``addr=<dbusaddr>`` : D-Bus bus address to connect to.
2107
Marc-André Lureau99997822021-10-10 00:16:57 +04002108 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``.
2109
2110 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface
2111 will share framebuffers with DMABUF file descriptors).
Marc-André Lureau142ca622021-07-15 11:53:53 +04002112
Thomas Huth95f439b2021-06-30 18:32:31 +02002113 ``sdl``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002114 Display video output via SDL (usually in a separate graphics
2115 window; see the SDL documentation for other possibilities).
Thomas Huth95f439b2021-06-30 18:32:31 +02002116 Valid parameters are:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002117
Thomas Huth8e8e8442021-08-25 11:20:21 +02002118 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling
John Snow450e0f22021-10-04 17:52:36 -04002119 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be
2120 either ``lshift-lctrl-lalt`` or ``rctrl``.
Thomas Huth8e8e8442021-08-25 11:20:21 +02002121
Thomas Huth95f439b2021-06-30 18:32:31 +02002122 ``gl=on|off|core|es`` : Use OpenGL for displaying
2123
2124 ``show-cursor=on|off`` : Force showing the mouse cursor
2125
2126 ``window-close=on|off`` : Allow to quit qemu with window close button
2127
2128 ``gtk``
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002129 Display video output in a GTK window. This interface provides
2130 drop-down menus and other UI elements to configure and control
Thomas Huth95f439b2021-06-30 18:32:31 +02002131 the VM during runtime. Valid parameters are:
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002132
Thomas Huth95f439b2021-06-30 18:32:31 +02002133 ``full-screen=on|off`` : Start in fullscreen mode
2134
2135 ``gl=on|off`` : Use OpenGL for displaying
2136
2137 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover
2138
Felix xq Queißnerc34a9332022-07-12 15:37:53 +02002139 ``show-tabs=on|off`` : Display the tab bar for switching between the
2140 various graphical interfaces (e.g. VGA and
2141 virtual console character devices) by default.
2142
Thomas Huth95f439b2021-06-30 18:32:31 +02002143 ``show-cursor=on|off`` : Force showing the mouse cursor
2144
2145 ``window-close=on|off`` : Allow to quit qemu with window close button
2146
Bryce Millsdbccb1a2022-10-11 13:58:21 +00002147 ``show-menubar=on|off`` : Display the main window menubar, defaults to "on"
2148
Jan Kratochvilc35d9372023-06-28 18:23:36 +08002149 ``zoom-to-fit=on|off`` : Expand video output to the window size,
2150 defaults to "off"
2151
Thomas Huth95f439b2021-06-30 18:32:31 +02002152 ``curses[,charset=<encoding>]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002153 Display video output via curses. For graphics device models
2154 which support a text mode, QEMU can display this output using a
2155 curses/ncurses interface. Nothing is displayed when the graphics
2156 device is in graphical mode or if the graphics device does not
2157 support a text mode. Generally only the VGA device models
2158 support text mode. The font charset used by the guest can be
2159 specified with the ``charset`` option, for example
2160 ``charset=CP850`` for IBM CP850 encoding. The default is
2161 ``CP437``.
2162
Carwyn Ellis48941a52022-01-02 17:41:52 +00002163 ``cocoa``
2164 Display video output in a Cocoa window. Mac only. This interface
2165 provides drop-down menus and other UI elements to configure and
2166 control the VM during runtime. Valid parameters are:
2167
Akihiko Odakid502dfc2023-12-14 15:31:36 +09002168 ``full-grab=on|off`` : Capture all key presses, including system combos.
2169 This requires accessibility permissions, since it
2170 performs a global grab on key events.
2171 (default: off) See
2172 https://support.apple.com/en-in/guide/mac-help/mh32356/mac
2173
2174 ``swap-opt-cmd=on|off`` : Swap the Option and Command keys so that their
2175 key codes match their position on non-Mac
2176 keyboards and you can use Meta/Super and Alt
2177 where you expect them. (default: off)
2178
Carwyn Ellis48941a52022-01-02 17:41:52 +00002179 ``show-cursor=on|off`` : Force showing the mouse cursor
2180
2181 ``left-command-key=on|off`` : Disable forwarding left command key to host
2182
Akihiko Odakid502dfc2023-12-14 15:31:36 +09002183 ``full-screen=on|off`` : Start in fullscreen mode
2184
2185 ``zoom-to-fit=on|off`` : Expand video output to the window size,
2186 defaults to "off"
2187
Thomas Huth95f439b2021-06-30 18:32:31 +02002188 ``egl-headless[,rendernode=<file>]``
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002189 Offload all OpenGL operations to a local DRI device. For any
2190 graphical display, this display needs to be paired with either
2191 VNC or SPICE displays.
2192
Thomas Huth95f439b2021-06-30 18:32:31 +02002193 ``vnc=<display>``
2194 Start a VNC server on display <display>
2195
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002196 ``none``
2197 Do not display video output. The guest will still see an
2198 emulated graphics card, but its output will not be displayed to
2199 the QEMU user. This option differs from the -nographic option in
2200 that it only affects what is done with video output; -nographic
2201 also changes the destination of the serial and parallel port
2202 data.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002203ERST
Jes Sorensen1472a952011-03-16 13:33:31 +01002204
blueswir15824d652009-03-28 06:44:27 +00002205DEF("nographic", 0, QEMU_OPTION_nographic,
Blue Swirlad960902010-03-29 19:23:52 +00002206 "-nographic disable graphical output and redirect serial I/Os to console\n",
2207 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002208SRST
2209``-nographic``
2210 Normally, if QEMU is compiled with graphical window support, it
2211 displays output such as guest graphics, guest console, and the QEMU
2212 monitor in a window. With this option, you can totally disable
2213 graphical output so that QEMU is a simple command line application.
2214 The emulated serial port is redirected on the console and muxed with
2215 the monitor (unless redirected elsewhere explicitly). Therefore, you
2216 can still use QEMU to debug a Linux kernel with a serial console.
2217 Use C-a h for help on switching between the console and monitor.
2218ERST
blueswir15824d652009-03-28 06:44:27 +00002219
Marc-André Lureau5324e3e2021-09-09 12:44:11 +04002220#ifdef CONFIG_SPICE
Gerd Hoffmann29b00402010-03-11 11:13:27 -03002221DEF("spice", HAS_ARG, QEMU_OPTION_spice,
Yonit Halperin27af7782012-08-21 13:54:20 +03002222 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
2223 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
2224 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002225 " [,x509-dh-key-file=<file>][,addr=addr]\n"
2226 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n"
Yonit Halperin27af7782012-08-21 13:54:20 +03002227 " [,tls-ciphers=<list>]\n"
2228 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
2229 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
Daniel P. Berrangé99522f62021-03-11 11:43:42 +00002230 " [,sasl=on|off][,disable-ticketing=on|off]\n"
Daniel P. Berrangé36debaf2022-12-01 04:22:11 -05002231 " [,password-secret=<secret-id>]\n"
Yonit Halperin27af7782012-08-21 13:54:20 +03002232 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
2233 " [,jpeg-wan-compression=[auto|never|always]]\n"
2234 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002235 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n"
2236 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n"
Hans de Goede5ad24e52013-06-08 15:37:27 +02002237 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
Marc-André Lureau7b525502017-02-12 15:21:18 +04002238 " [,gl=[on|off]][,rendernode=<file>]\n"
Thomas Hutha635bcf2023-07-03 09:56:46 +02002239 " enable spice\n"
2240 " at least one of {port, tls-port} is mandatory\n",
Yonit Halperin27af7782012-08-21 13:54:20 +03002241 QEMU_ARCH_ALL)
Marc-André Lureau5324e3e2021-09-09 12:44:11 +04002242#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002243SRST
2244``-spice option[,option[,...]]``
2245 Enable the spice remote desktop protocol. Valid options are
2246
2247 ``port=<nr>``
2248 Set the TCP port spice is listening on for plaintext channels.
2249
2250 ``addr=<addr>``
2251 Set the IP address spice is listening on. Default is any
2252 address.
2253
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002254 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002255 Force using the specified IP version.
2256
Daniel P. Berrangé99522f62021-03-11 11:43:42 +00002257 ``password-secret=<secret-id>``
2258 Set the ID of the ``secret`` object containing the password
2259 you need to authenticate.
2260
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002261 ``sasl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002262 Require that the client use SASL to authenticate with the spice.
2263 The exact choice of authentication method used is controlled
2264 from the system / user's SASL configuration file for the 'qemu'
2265 service. This is typically found in /etc/sasl2/qemu.conf. If
2266 running QEMU as an unprivileged user, an environment variable
2267 SASL\_CONF\_PATH can be used to make it search alternate
2268 locations for the service config. While some SASL auth methods
2269 can also provide data encryption (eg GSSAPI), it is recommended
2270 that SASL always be combined with the 'tls' and 'x509' settings
2271 to enable use of SSL and server certificates. This ensures a
2272 data encryption preventing compromise of authentication
2273 credentials.
2274
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002275 ``disable-ticketing=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002276 Allow client connects without authentication.
2277
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002278 ``disable-copy-paste=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002279 Disable copy paste between the client and the guest.
2280
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002281 ``disable-agent-file-xfer=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002282 Disable spice-vdagent based file-xfer between the client and the
2283 guest.
2284
2285 ``tls-port=<nr>``
2286 Set the TCP port spice is listening on for encrypted channels.
2287
2288 ``x509-dir=<dir>``
2289 Set the x509 file directory. Expects same filenames as -vnc
2290 $display,x509=$dir
2291
2292 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>``
2293 The x509 file names can also be configured individually.
2294
2295 ``tls-ciphers=<list>``
2296 Specify which ciphers to use.
2297
2298 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]``
2299 Force specific channel to be used with or without TLS
2300 encryption. The options can be specified multiple times to
2301 configure multiple channels. The special name "default" can be
2302 used to set the default mode. For channels which are not
2303 explicitly forced into one mode the spice client is allowed to
2304 pick tls/plaintext as he pleases.
2305
2306 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]``
2307 Configure image compression (lossless). Default is auto\_glz.
2308
2309 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]``
2310 Configure wan image compression (lossy for slow links). Default
2311 is auto.
2312
2313 ``streaming-video=[off|all|filter]``
2314 Configure video stream detection. Default is off.
2315
2316 ``agent-mouse=[on|off]``
2317 Enable/disable passing mouse events via vdagent. Default is on.
2318
2319 ``playback-compression=[on|off]``
2320 Enable/disable audio stream compression (using celt 0.5.1).
2321 Default is on.
2322
2323 ``seamless-migration=[on|off]``
2324 Enable/disable spice seamless migration. Default is off.
2325
2326 ``gl=[on|off]``
2327 Enable/disable OpenGL context. Default is off.
2328
2329 ``rendernode=<file>``
2330 DRM render node for OpenGL rendering. If not specified, it will
2331 pick the first available. (Since 2.9)
2332ERST
Gerd Hoffmann29b00402010-03-11 11:13:27 -03002333
blueswir15824d652009-03-28 06:44:27 +00002334DEF("vga", HAS_ARG, QEMU_OPTION_vga,
Gerd Hoffmanna94f0c52014-09-10 14:28:48 +02002335 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
Blue Swirlad960902010-03-29 19:23:52 +00002336 " select video card type\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002337SRST
2338``-vga type``
2339 Select type of VGA card to emulate. Valid values for type are
2340
2341 ``cirrus``
2342 Cirrus Logic GD5446 Video card. All Windows versions starting
2343 from Windows 95 should recognize and use this graphic card. For
2344 optimal performances, use 16 bit color depth in the guest and
2345 the host OS. (This card was the default before QEMU 2.2)
2346
2347 ``std``
2348 Standard VGA card with Bochs VBE extensions. If your guest OS
2349 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if
2350 you want to use high resolution modes (>= 1280x1024x16) then you
2351 should use this option. (This card is the default since QEMU
2352 2.2)
2353
2354 ``vmware``
2355 VMWare SVGA-II compatible adapter. Use it if you have
2356 sufficiently recent XFree86/XOrg server or Windows guest with a
2357 driver for this card.
2358
2359 ``qxl``
2360 QXL paravirtual graphic card. It is VGA compatible (including
2361 VESA 2.0 VBE support). Works best with qxl guest drivers
2362 installed though. Recommended choice when using the spice
2363 protocol.
2364
2365 ``tcx``
2366 (sun4m only) Sun TCX framebuffer. This is the default
2367 framebuffer for sun4m machines and offers both 8-bit and 24-bit
2368 colour depths at a fixed resolution of 1024x768.
2369
2370 ``cg3``
2371 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit
2372 framebuffer for sun4m machines available in both 1024x768
2373 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people
2374 wishing to run older Solaris versions.
2375
2376 ``virtio``
2377 Virtio VGA card.
2378
2379 ``none``
2380 Disable VGA card.
2381ERST
blueswir15824d652009-03-28 06:44:27 +00002382
2383DEF("full-screen", 0, QEMU_OPTION_full_screen,
Blue Swirlad960902010-03-29 19:23:52 +00002384 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002385SRST
2386``-full-screen``
2387 Start in full screen.
2388ERST
blueswir15824d652009-03-28 06:44:27 +00002389
John Snow60f9a4e2020-02-04 11:56:38 -05002390DEF("g", HAS_ARG, QEMU_OPTION_g ,
Blue Swirlad960902010-03-29 19:23:52 +00002391 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
Laurent Vivier8ac919a2019-10-26 18:45:43 +02002392 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002393SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00002394``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002395 Set the initial graphical resolution and depth (PPC, SPARC only).
2396
2397 For PPC the default is 800x600x32.
2398
2399 For SPARC with the TCX graphics device, the default is 1024x768x8
2400 with the option of 1024x768x24. For cgthree, the default is
2401 1024x768x8 with the option of 1152x900x8 for people who wish to use
2402 OBP.
2403ERST
blueswir15824d652009-03-28 06:44:27 +00002404
Marc-André Lureau62611642023-10-25 17:05:08 +04002405#ifdef CONFIG_VNC
blueswir15824d652009-03-28 06:44:27 +00002406DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
Robert Hof04ec5a2016-07-26 18:17:11 +08002407 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
Marc-André Lureau62611642023-10-25 17:05:08 +04002408#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002409SRST
2410``-vnc display[,option[,option[,...]]]``
2411 Normally, if QEMU is compiled with graphical window support, it
2412 displays output such as guest graphics, guest console, and the QEMU
2413 monitor in a window. With this option, you can have QEMU listen on
2414 VNC display display and redirect the VGA display over the VNC
2415 session. It is very useful to enable the usb tablet device when
2416 using this option (option ``-device usb-tablet``). When using the
2417 VNC display, you must use the ``-k`` parameter to set the keyboard
2418 layout if you are not using en-us. Valid syntax for the display is
2419
2420 ``to=L``
2421 With this option, QEMU will try next available VNC displays,
Manos Pitsidianakis835f3642024-02-20 10:52:23 +02002422 until the number L, if the originally defined "-vnc display" is
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002423 not available, e.g. port 5900+display is already used by another
2424 application. By default, to=0.
2425
2426 ``host:d``
2427 TCP connections will only be allowed from host on display d. By
2428 convention the TCP port is 5900+d. Optionally, host can be
2429 omitted in which case the server will accept connections from
2430 any host.
2431
2432 ``unix:path``
2433 Connections will be allowed over UNIX domain sockets where path
2434 is the location of a unix socket to listen for connections on.
2435
2436 ``none``
2437 VNC is initialized but not started. The monitor ``change``
2438 command can be used to later start the VNC server.
2439
2440 Following the display value there may be one or more option flags
2441 separated by commas. Valid options are
2442
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002443 ``reverse=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002444 Connect to a listening VNC client via a "reverse" connection.
2445 The client is specified by the display. For reverse network
2446 connections (host:d,``reverse``), the d argument is a TCP port
2447 number, not a display number.
2448
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002449 ``websocket=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002450 Opens an additional TCP listening port dedicated to VNC
2451 Websocket connections. If a bare websocket option is given, the
2452 Websocket port is 5700+display. An alternative port can be
2453 specified with the syntax ``websocket``\ =port.
2454
2455 If host is specified connections will only be allowed from this
2456 host. It is possible to control the websocket listen address
2457 independently, using the syntax ``websocket``\ =host:port.
2458
Sergii Zasenko41582632023-07-24 13:03:53 +03002459 Websocket could be allowed over UNIX domain socket, using the syntax
2460 ``websocket``\ =unix:path, where path is the location of a unix socket
2461 to listen for connections on.
2462
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002463 If no TLS credentials are provided, the websocket connection
2464 runs in unencrypted mode. If TLS credentials are provided, the
2465 websocket connection requires encrypted client connections.
2466
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002467 ``password=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002468 Require that password based authentication is used for client
2469 connections.
2470
2471 The password must be set separately using the ``set_password``
Thomas Huth923e9312020-11-16 15:47:36 +01002472 command in the :ref:`QEMU monitor`. The
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002473 syntax to change your password is:
2474 ``set_password <protocol> <password>`` where <protocol> could be
2475 either "vnc" or "spice".
2476
2477 If you would like to change <protocol> password expiration, you
2478 should use ``expire_password <protocol> <expiration-time>``
2479 where expiration time could be one of the following options:
2480 now, never, +seconds or UNIX time of expiration, e.g. +60 to
2481 make password expire in 60 seconds, or 1335196800 to make
2482 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for
2483 this date and time).
2484
2485 You can also use keywords "now" or "never" for the expiration
2486 time to allow <protocol> password to expire immediately or never
2487 expire.
2488
Daniel P. Berrangé6c6840e2021-03-11 11:43:41 +00002489 ``password-secret=<secret-id>``
2490 Require that password based authentication is used for client
2491 connections, using the password provided by the ``secret``
2492 object identified by ``secret-id``.
2493
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002494 ``tls-creds=ID``
2495 Provides the ID of a set of TLS credentials to use to secure the
2496 VNC server. They will apply to both the normal VNC server socket
2497 and the websocket socket (if enabled). Setting TLS credentials
2498 will cause the VNC server socket to enable the VeNCrypt auth
2499 mechanism. The credentials should have been previously created
2500 using the ``-object tls-creds`` argument.
2501
2502 ``tls-authz=ID``
2503 Provides the ID of the QAuthZ authorization object against which
2504 the client's x509 distinguished name will validated. This object
2505 is only resolved at time of use, so can be deleted and recreated
2506 on the fly while the VNC server is active. If missing, it will
2507 default to denying access.
2508
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002509 ``sasl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002510 Require that the client use SASL to authenticate with the VNC
2511 server. The exact choice of authentication method used is
2512 controlled from the system / user's SASL configuration file for
2513 the 'qemu' service. This is typically found in
2514 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user,
2515 an environment variable SASL\_CONF\_PATH can be used to make it
2516 search alternate locations for the service config. While some
2517 SASL auth methods can also provide data encryption (eg GSSAPI),
2518 it is recommended that SASL always be combined with the 'tls'
2519 and 'x509' settings to enable use of SSL and server
2520 certificates. This ensures a data encryption preventing
2521 compromise of authentication credentials. See the
Thomas Huth923e9312020-11-16 15:47:36 +01002522 :ref:`VNC security` section in the System Emulation Users Guide
2523 for details on using SASL authentication.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002524
2525 ``sasl-authz=ID``
2526 Provides the ID of the QAuthZ authorization object against which
2527 the client's SASL username will validated. This object is only
2528 resolved at time of use, so can be deleted and recreated on the
2529 fly while the VNC server is active. If missing, it will default
2530 to denying access.
2531
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002532 ``acl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002533 Legacy method for enabling authorization of clients against the
2534 x509 distinguished name and SASL username. It results in the
2535 creation of two ``authz-list`` objects with IDs of
2536 ``vnc.username`` and ``vnc.x509dname``. The rules for these
2537 objects must be configured with the HMP ACL commands.
2538
2539 This option is deprecated and should no longer be used. The new
2540 ``sasl-authz`` and ``tls-authz`` options are a replacement.
2541
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002542 ``lossy=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002543 Enable lossy compression methods (gradient, JPEG, ...). If this
2544 option is set, VNC client may receive lossy framebuffer updates
2545 depending on its encoding settings. Enabling this option can
2546 save a lot of bandwidth at the expense of quality.
2547
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002548 ``non-adaptive=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002549 Disable adaptive encodings. Adaptive encodings are enabled by
2550 default. An adaptive encoding will try to detect frequently
2551 updated screen regions, and send updates in these regions using
2552 a lossy encoding (like JPEG). This can be really helpful to save
2553 bandwidth when playing videos. Disabling adaptive encodings
2554 restores the original static behavior of encodings like Tight.
2555
2556 ``share=[allow-exclusive|force-shared|ignore]``
2557 Set display sharing policy. 'allow-exclusive' allows clients to
2558 ask for exclusive access. As suggested by the rfb spec this is
2559 implemented by dropping other connections. Connecting multiple
2560 clients in parallel requires all clients asking for a shared
2561 session (vncviewer: -shared switch). This is the default.
2562 'force-shared' disables exclusive client access. Useful for
2563 shared desktop sessions, where you don't want someone forgetting
2564 specify -shared disconnect everybody else. 'ignore' completely
2565 ignores the shared flag and allows everybody connect
2566 unconditionally. Doesn't conform to the rfb spec but is
2567 traditional QEMU behavior.
2568
2569 ``key-delay-ms``
2570 Set keyboard delay, for key down and key up events, in
2571 milliseconds. Default is 10. Keyboards are low-bandwidth
2572 devices, so this slowdown can help the device and guest to keep
2573 up and not lose events in case events are arriving in bulk.
2574 Possible causes for the latter are flaky network connections, or
2575 scripts for automated testing.
2576
2577 ``audiodev=audiodev``
2578 Use the specified audiodev when the VNC client requests audio
2579 transmission. When not using an -audiodev argument, this option
2580 must be omitted, otherwise is must be present and specify a
2581 valid audiodev.
Daniel P. Berrangé7b5fa0b2020-12-11 16:08:25 +00002582
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002583 ``power-control=on|off``
Daniel P. Berrangé7b5fa0b2020-12-11 16:08:25 +00002584 Permit the remote client to issue shutdown, reboot or reset power
2585 control requests.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002586ERST
blueswir15824d652009-03-28 06:44:27 +00002587
Michael Ellermana3adb7a2011-12-19 17:19:31 +11002588ARCHHEADING(, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002589
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002590ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002591
blueswir15824d652009-03-28 06:44:27 +00002592DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
Blue Swirlad960902010-03-29 19:23:52 +00002593 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
2594 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002595SRST
2596``-win2k-hack``
2597 Use it when installing Windows 2000 to avoid a disk full bug. After
2598 Windows 2000 is installed, you no longer need this option (this
Paolo Bonzinid13f4032024-02-20 17:09:30 +01002599 option slows down the IDE transfers). Synonym of ``-global
2600 ide-device.win2k-install-hack=on``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002601ERST
blueswir15824d652009-03-28 06:44:27 +00002602
blueswir15824d652009-03-28 06:44:27 +00002603DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
Blue Swirlad960902010-03-29 19:23:52 +00002604 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
2605 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002606SRST
2607``-no-fd-bootchk``
2608 Disable boot signature checking for floppy disks in BIOS. May be
Paolo Bonzini84e945a2024-02-13 10:56:56 +01002609 needed to boot from old floppy disks. Synonym of ``-m fd-bootchk=off``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002610ERST
blueswir15824d652009-03-28 06:44:27 +00002611
blueswir15824d652009-03-28 06:44:27 +00002612DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
Michael Tokarev104bf022011-05-12 18:44:17 +04002613 "-acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n][,asl_compiler_id=str][,asl_compiler_rev=n][,{data|file}=file1[:file2]...]\n"
Blue Swirlad960902010-03-29 19:23:52 +00002614 " ACPI table description\n", QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002615SRST
2616``-acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n] [,asl_compiler_id=str][,asl_compiler_rev=n][,data=file1[:file2]...]``
2617 Add ACPI table with specified header fields and context from
2618 specified files. For file=, take whole ACPI table from the specified
2619 files, including all ACPI headers (possible overridden by other
2620 options). For data=, only data portion of the table is used, all
2621 header information is specified in the command line. If a SLIC table
2622 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id
2623 fields will override the same in the RSDT and the FADT (a.k.a.
2624 FACP), in order to ensure the field matches required by the
2625 Microsoft SLIC spec and the ACPI spec.
2626ERST
blueswir15824d652009-03-28 06:44:27 +00002627
aliguorib6f6e3d2009-04-17 18:59:56 +00002628DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
2629 "-smbios file=binary\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002630 " load SMBIOS entry from binary file\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002631 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
2632 " [,uefi=on|off]\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002633 " specify SMBIOS type 0 fields\n"
aliguorib6f6e3d2009-04-17 18:59:56 +00002634 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2635 " [,uuid=uuid][,sku=str][,family=str]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002636 " specify SMBIOS type 1 fields\n"
2637 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2638 " [,asset=str][,location=str]\n"
2639 " specify SMBIOS type 2 fields\n"
2640 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
2641 " [,sku=str]\n"
2642 " specify SMBIOS type 3 fields\n"
2643 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
Ying Fangc906e032020-08-06 11:56:33 +08002644 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n"
Heinrich Schuchardt68baeaa2024-07-29 22:48:15 +02002645 " [,processor-family=%d][,processor-id=%d]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002646 " specify SMBIOS type 4 fields\n"
Hal Martinfd8caa22022-08-12 15:51:53 +02002647 "-smbios type=8[,external_reference=str][,internal_reference=str][,connector_type=%d][,port_type=%d]\n"
2648 " specify SMBIOS type 8 fields\n"
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002649 "-smbios type=11[,value=str][,path=filename]\n"
2650 " specify SMBIOS type 11 fields\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002651 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
Gabriel L. Somlo3ebd6cc2015-03-11 13:58:01 -04002652 " [,asset=str][,part=str][,speed=%d]\n"
Vincent Bernat05dfb442021-04-01 19:11:38 +02002653 " specify SMBIOS type 17 fields\n"
2654 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n"
2655 " specify SMBIOS type 41 fields\n",
Heinrich Schuchardte2ff0de2024-01-23 19:42:29 +01002656 QEMU_ARCH_I386 | QEMU_ARCH_ARM | QEMU_ARCH_LOONGARCH | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002657SRST
2658``-smbios file=binary``
2659 Load SMBIOS entry from binary file.
2660
2661``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]``
2662 Specify SMBIOS type 0 fields
2663
2664``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]``
2665 Specify SMBIOS type 1 fields
2666
2667``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]``
2668 Specify SMBIOS type 2 fields
2669
2670``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]``
2671 Specify SMBIOS type 3 fields
2672
Heinrich Schuchardtb5831d72024-01-23 19:42:26 +01002673``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str][,processor-family=%d][,processor-id=%d]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002674 Specify SMBIOS type 4 fields
2675
Felix Wu04f143d2024-02-21 17:00:27 +00002676``-smbios type=9[,slot_designation=str][,slot_type=%d][,slot_data_bus_width=%d][,current_usage=%d][,slot_length=%d][,slot_id=%d][,slot_characteristics1=%d][,slot_characteristics12=%d][,pci_device=str]``
Felix Wu735eee02024-02-21 17:00:26 +00002677 Specify SMBIOS type 9 fields
2678
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002679``-smbios type=11[,value=str][,path=filename]``
2680 Specify SMBIOS type 11 fields
2681
2682 This argument can be repeated multiple times, and values are added in the order they are parsed.
2683 Applications intending to use OEM strings data are encouraged to use their application name as
2684 a prefix for the value string. This facilitates passing information for multiple applications
2685 concurrently.
2686
2687 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax
2688 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes.
2689
2690 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to
2691 the SMBIOS table in the order in which they appear.
2692
2693 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535
2694 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the
2695 guest. Instead it should be used as a indicator to inform the guest where to locate the real
2696 data set, for example, by specifying the serial ID of a block device.
2697
2698 An example passing three strings is
2699
2700 .. parsed-literal::
2701
2702 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\
2703 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\
2704 path=/some/file/with/oemstringsdata.txt
2705
2706 In the guest OS this is visible with the ``dmidecode`` command
2707
2708 .. parsed-literal::
2709
2710 $ dmidecode -t 11
2711 Handle 0x0E00, DMI type 11, 5 bytes
2712 OEM Strings
2713 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/
2714 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os
2715 String 3: myapp:some extra data
2716
2717
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002718``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]``
2719 Specify SMBIOS type 17 fields
Vincent Bernat05dfb442021-04-01 19:11:38 +02002720
2721``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]``
2722 Specify SMBIOS type 41 fields
2723
2724 This argument can be repeated multiple times. Its main use is to allow network interfaces be created
2725 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface
2726 position on the PCI bus.
2727
2728 Here is an example of use:
2729
2730 .. parsed-literal::
2731
2732 -netdev user,id=internet \\
2733 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\
2734 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev
2735
2736 In the guest OS, the device should then appear as ``eno1``:
2737
2738 ..parsed-literal::
2739
2740 $ ip -brief l
2741 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP>
2742 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP>
2743
2744 Currently, the PCI device has to be attached to the root bus.
2745
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002746ERST
aliguorib6f6e3d2009-04-17 18:59:56 +00002747
Markus Armbrusterc70a01e2013-02-13 19:49:40 +01002748DEFHEADING()
blueswir15824d652009-03-28 06:44:27 +00002749
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002750DEFHEADING(Network options:)
blueswir15824d652009-03-28 06:44:27 +00002751
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002752DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
blueswir15824d652009-03-28 06:44:27 +00002753#ifdef CONFIG_SLIRP
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00002754 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n"
2755 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
Samuel Thibault0b11c032016-03-20 12:29:54 +01002756 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
Benjamin Drungf18d1372018-02-27 17:06:01 +01002757 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
Fam Zheng0fca92b2018-09-14 15:26:16 +08002758 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002759#ifndef _WIN32
Jan Kiszkac92ef6a2009-06-24 14:42:28 +02002760 "[,smb=dir[,smbserver=addr]]\n"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002761#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002762 " configure a user mode network backend with ID 'str',\n"
2763 " its DHCP server and optional services\n"
blueswir15824d652009-03-28 06:44:27 +00002764#endif
2765#ifdef _WIN32
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002766 "-netdev tap,id=str,ifname=name\n"
2767 " configure a host TAP network backend with ID 'str'\n"
blueswir15824d652009-03-28 06:44:27 +00002768#else
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002769 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002770 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002771 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002772 " [,poll-us=n]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002773 " configure a host TAP network backend with ID 'str'\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002774 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002775 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
2776 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
2777 " to deconfigure it\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002778 " use '[down]script=no' to disable script execution\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002779 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
2780 " configure it\n"
blueswir15824d652009-03-28 06:44:27 +00002781 " use 'fd=h' to connect to an already opened TAP interface\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002782 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002783 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
Michael S. Tsirkinf157ed22011-02-01 14:25:40 +02002784 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002785 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
2786 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
Michael S. Tsirkin82b0d802010-03-17 13:08:24 +02002787 " use vhost=on to enable experimental in kernel accelerator\n"
mst@redhat.com5430a282011-02-01 22:13:42 +02002788 " (only has effect for virtio guests which use MSIX)\n"
2789 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
Michael S. Tsirkin82b0d802010-03-17 13:08:24 +02002790 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002791 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
Jason Wangec396012013-02-22 22:57:52 +08002792 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
Michael Tokarevcba42d62021-03-09 14:15:10 +03002793 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002794 " spent on busy polling for vhost net\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002795 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
2796 " configure a host TAP network backend with ID 'str' that is\n"
2797 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
2798 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
Mark McLoughlin0df0ff62009-06-18 18:21:34 +01002799#endif
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002800#ifdef __linux__
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002801 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00002802 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n"
2803 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002804 " [,rxcookie=rxcookie][,offset=offset]\n"
2805 " configure a network backend with ID 'str' connected to\n"
2806 " an Ethernet over L2TPv3 pseudowire.\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002807 " Linux kernel 3.3+ as well as most routers can talk\n"
Michael Tokarev2f47b402014-07-24 20:10:17 +04002808 " L2TPv3. This transport allows connecting a VM to a VM,\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002809 " VM to a router and even VM to Host. It is a nearly-universal\n"
Stefan Hajnoczi21843dc2020-02-29 11:17:27 +00002810 " standard (RFC3931). Note - this implementation uses static\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002811 " pre-configured tunnels (same as the Linux kernel).\n"
2812 " use 'src=' to specify source address\n"
2813 " use 'dst=' to specify destination address\n"
2814 " use 'udp=on' to specify udp encapsulation\n"
Gonglei39526512014-08-14 14:35:48 +08002815 " use 'srcport=' to specify source udp port\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002816 " use 'dstport=' to specify destination udp port\n"
2817 " use 'ipv6=on' to force v6\n"
2818 " L2TPv3 uses cookies to prevent misconfiguration as\n"
2819 " well as a weak security measure\n"
2820 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
2821 " use 'txcookie=0x012345678' to specify a txcookie\n"
2822 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
2823 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
2824 " use 'pincounter=on' to work around broken counter handling in peer\n"
2825 " use 'offset=X' to add an extra offset between header and data\n"
2826#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002827 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
2828 " configure a network backend to connect to another network\n"
2829 " using a socket connection\n"
2830 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
2831 " configure a network backend to connect to a multicast maddr and port\n"
Mike Ryan3a75e742010-12-01 11:16:47 -08002832 " use 'localaddr=addr' to specify the host address to send packets from\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002833 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
2834 " configure a network backend to connect to another network\n"
2835 " using an UDP tunnel\n"
Daniil Tatianinc40e9622024-10-25 10:35:24 +03002836 "-netdev stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port[,to=maxport][,numeric=on|off][,keep-alive=on|off][,mptcp=on|off][,addr.ipv4=on|off][,addr.ipv6=on|off][,reconnect-ms=milliseconds]\n"
2837 "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect-ms=milliseconds]\n"
2838 "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect-ms=milliseconds]\n"
Laurent Vivier5166fe02022-10-21 11:09:11 +02002839 " configure a network backend to connect to another network\n"
2840 " using a socket connection in stream mode.\n"
2841 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n"
2842 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]\n"
2843 " configure a network backend to connect to a multicast maddr and port\n"
2844 " use ``local.host=addr`` to specify the host address to send packets from\n"
2845 "-netdev dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]\n"
Laurent Vivier784e7a22022-10-21 11:09:17 +02002846 "-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]\n"
Laurent Vivier5166fe02022-10-21 11:09:11 +02002847 "-netdev dgram,id=str,local.type=fd,local.str=file-descriptor\n"
2848 " configure a network backend to connect to another network\n"
2849 " using an UDP tunnel\n"
blueswir15824d652009-03-28 06:44:27 +00002850#ifdef CONFIG_VDE
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002851 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
2852 " configure a network backend to connect to port 'n' of a vde switch\n"
2853 " running on host and listening for incoming connections on 'socketpath'.\n"
blueswir15824d652009-03-28 06:44:27 +00002854 " Use group 'groupname' and mode 'octalmode' to change default\n"
2855 " ownership and permissions for communication port.\n"
2856#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002857#ifdef CONFIG_NETMAP
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002858 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
Vincenzo Maffione58952132013-11-06 11:44:06 +01002859 " attach to the existing netmap-enabled network interface 'name', or to a\n"
2860 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
2861 " netmap device, defaults to '/dev/netmap')\n"
2862#endif
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002863#ifdef CONFIG_AF_XDP
2864 "-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off]\n"
2865 " [,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]\n"
2866 " attach to the existing network interface 'name' with AF_XDP socket\n"
2867 " use 'mode=MODE' to specify an XDP program attach mode\n"
2868 " use 'force-copy=on|off' to force XDP copy mode even if device supports zero-copy (default: off)\n"
2869 " use 'inhibit=on|off' to inhibit loading of a default XDP program (default: off)\n"
2870 " with inhibit=on,\n"
2871 " use 'sock-fds' to provide file descriptors for already open AF_XDP sockets\n"
2872 " added to a socket map in XDP program. One socket per queue.\n"
2873 " use 'queues=n' to specify how many queues of a multiqueue interface should be used\n"
2874 " use 'start-queue=m' to specify the first queue that should be used\n"
2875#endif
Thomas Huth253dc142018-02-21 11:18:32 +01002876#ifdef CONFIG_POSIX
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002877 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2878 " configure a vhost-user network, backed by a chardev 'dev'\n"
Thomas Huth253dc142018-02-21 11:18:32 +01002879#endif
Cindy Lu108a6482020-07-01 22:55:37 +08002880#ifdef __linux__
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07002881 "-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n"
Cindy Lu108a6482020-07-01 22:55:37 +08002882 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n"
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07002883 " use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n"
2884 " use 'vhostfd=h' to connect to an already opened vhost vdpa device\n"
Cindy Lu108a6482020-07-01 22:55:37 +08002885#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002886#ifdef CONFIG_VMNET
2887 "-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n"
2888 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n"
2889 " configure a vmnet network backend in host mode with ID 'str',\n"
2890 " isolate this interface from others with 'isolated',\n"
2891 " configure the address range and choose a subnet mask,\n"
2892 " specify network UUID 'uuid' to disable DHCP and interact with\n"
2893 " vmnet-host interfaces within this isolated network\n"
2894 "-netdev vmnet-shared,id=str[,isolated=on|off][,nat66-prefix=addr]\n"
2895 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n"
2896 " configure a vmnet network backend in shared mode with ID 'str',\n"
2897 " configure the address range and choose a subnet mask,\n"
2898 " set IPv6 ULA prefix (of length 64) to use for internal network,\n"
2899 " isolate this interface from others with 'isolated'\n"
2900 "-netdev vmnet-bridged,id=str,ifname=name[,isolated=on|off]\n"
2901 " configure a vmnet network backend in bridged mode with ID 'str',\n"
2902 " use 'ifname=name' to select a physical network interface to be bridged,\n"
2903 " isolate this interface from others with 'isolated'\n"
2904#endif
Thomas Huth18d65d22018-01-15 20:50:55 +01002905 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002906 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
Thomas Huth78cd6f72018-02-21 11:18:36 +01002907DEF("nic", HAS_ARG, QEMU_OPTION_nic,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002908 "-nic [tap|bridge|"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002909#ifdef CONFIG_SLIRP
2910 "user|"
2911#endif
2912#ifdef __linux__
2913 "l2tpv3|"
2914#endif
2915#ifdef CONFIG_VDE
2916 "vde|"
2917#endif
2918#ifdef CONFIG_NETMAP
2919 "netmap|"
2920#endif
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002921#ifdef CONFIG_AF_XDP
2922 "af-xdp|"
2923#endif
Thomas Huth78cd6f72018-02-21 11:18:36 +01002924#ifdef CONFIG_POSIX
2925 "vhost-user|"
2926#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002927#ifdef CONFIG_VMNET
2928 "vmnet-host|vmnet-shared|vmnet-bridged|"
2929#endif
Thomas Huth78cd6f72018-02-21 11:18:36 +01002930 "socket][,option][,...][mac=macaddr]\n"
2931 " initialize an on-board / default host NIC (using MAC address\n"
2932 " macaddr) and connect it to the given host network backend\n"
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002933 "-nic none use it alone to have zero network devices (the default is to\n"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002934 " provided a 'user' network connection)\n",
2935 QEMU_ARCH_ALL)
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002936DEF("net", HAS_ARG, QEMU_OPTION_net,
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002937 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
Thomas Huth0e60a822017-12-19 16:28:55 +01002938 " configure or create an on-board (or machine default) NIC and\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002939 " connect it to hub 0 (please use -nic unless you need a hub)\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002940 "-net ["
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002941#ifdef CONFIG_SLIRP
2942 "user|"
2943#endif
2944 "tap|"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002945 "bridge|"
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002946#ifdef CONFIG_VDE
2947 "vde|"
2948#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002949#ifdef CONFIG_NETMAP
2950 "netmap|"
2951#endif
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002952#ifdef CONFIG_AF_XDP
2953 "af-xdp|"
2954#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002955#ifdef CONFIG_VMNET
2956 "vmnet-host|vmnet-shared|vmnet-bridged|"
2957#endif
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002958 "socket][,option][,option][,...]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002959 " old way to initialize a host network interface\n"
2960 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002961SRST
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002962``-nic [tap|bridge|user|l2tpv3|vde|netmap|af-xdp|vhost-user|socket][,...][,mac=macaddr][,model=mn]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002963 This option is a shortcut for configuring both the on-board
2964 (default) guest NIC hardware and the host network backend in one go.
2965 The host backend options are the same as with the corresponding
2966 ``-netdev`` options below. The guest NIC model can be set with
2967 ``model=modelname``. Use ``model=help`` to list the available device
2968 types. The hardware MAC address can be set with ``mac=macaddr``.
2969
2970 The following two example do exactly the same, to show how ``-nic``
2971 can be used to shorten the command line length:
2972
2973 .. parsed-literal::
2974
2975 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
2976 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2977
2978``-nic none``
2979 Indicate that no network devices should be configured. It is used to
2980 override the default configuration (default NIC with "user" host
2981 network backend) which is activated if no other networking options
2982 are provided.
2983
2984``-netdev user,id=id[,option][,option][,...]``
2985 Configure user mode host network backend which requires no
2986 administrator privilege to run. Valid options are:
2987
2988 ``id=id``
2989 Assign symbolic name for use in monitor commands.
2990
2991 ``ipv4=on|off and ipv6=on|off``
2992 Specify that either IPv4 or IPv6 must be enabled. If neither is
2993 specified both protocols are enabled.
2994
2995 ``net=addr[/mask]``
2996 Set IP network address the guest will see. Optionally specify
2997 the netmask, either in the form a.b.c.d or as number of valid
2998 top-most bits. Default is 10.0.2.0/24.
2999
3000 ``host=addr``
3001 Specify the guest-visible address of the host. Default is the
3002 2nd IP in the guest network, i.e. x.x.x.2.
3003
3004 ``ipv6-net=addr[/int]``
3005 Set IPv6 network address the guest will see (default is
3006 fec0::/64). The network prefix is given in the usual hexadecimal
3007 IPv6 address notation. The prefix size is optional, and is given
3008 as the number of valid top-most bits (default is 64).
3009
3010 ``ipv6-host=addr``
3011 Specify the guest-visible IPv6 address of the host. Default is
3012 the 2nd IPv6 in the guest network, i.e. xxxx::2.
3013
3014 ``restrict=on|off``
3015 If this option is enabled, the guest will be isolated, i.e. it
3016 will not be able to contact the host and no guest IP packets
3017 will be routed over the host to the outside. This option does
3018 not affect any explicitly set forwarding rules.
3019
3020 ``hostname=name``
3021 Specifies the client hostname reported by the built-in DHCP
3022 server.
3023
3024 ``dhcpstart=addr``
3025 Specify the first of the 16 IPs the built-in DHCP server can
3026 assign. Default is the 15th to 31st IP in the guest network,
3027 i.e. x.x.x.15 to x.x.x.31.
3028
3029 ``dns=addr``
3030 Specify the guest-visible address of the virtual nameserver. The
3031 address must be different from the host address. Default is the
3032 3rd IP in the guest network, i.e. x.x.x.3.
3033
3034 ``ipv6-dns=addr``
3035 Specify the guest-visible address of the IPv6 virtual
3036 nameserver. The address must be different from the host address.
3037 Default is the 3rd IP in the guest network, i.e. xxxx::3.
3038
3039 ``dnssearch=domain``
3040 Provides an entry for the domain-search list sent by the
3041 built-in DHCP server. More than one domain suffix can be
3042 transmitted by specifying this option multiple times. If
3043 supported, this will cause the guest to automatically try to
3044 append the given domain suffix(es) in case a domain name can not
3045 be resolved.
3046
3047 Example:
3048
3049 .. parsed-literal::
3050
3051 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
3052
3053 ``domainname=domain``
3054 Specifies the client domain name reported by the built-in DHCP
3055 server.
3056
3057 ``tftp=dir``
3058 When using the user mode network stack, activate a built-in TFTP
3059 server. The files in dir will be exposed as the root of a TFTP
3060 server. The TFTP client on the guest must be configured in
3061 binary mode (use the command ``bin`` of the Unix TFTP client).
Michael Tokarevb30fa6b2024-02-08 09:00:50 +03003062 The built-in TFTP server is read-only; it does not implement any
3063 command for writing files. QEMU will not write to this directory.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003064
3065 ``tftp-server-name=name``
3066 In BOOTP reply, broadcast name as the "TFTP server name"
3067 (RFC2132 option 66). This can be used to advise the guest to
3068 load boot files or configurations from a different server than
3069 the host address.
3070
3071 ``bootfile=file``
3072 When using the user mode network stack, broadcast file as the
3073 BOOTP filename. In conjunction with ``tftp``, this can be used
3074 to network boot a guest from a local directory.
3075
3076 Example (using pxelinux):
3077
3078 .. parsed-literal::
3079
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003080 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003081 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
3082
3083 ``smb=dir[,smbserver=addr]``
3084 When using the user mode network stack, activate a built-in SMB
3085 server so that Windows OSes can access to the host files in
3086 ``dir`` transparently. The IP address of the SMB server can be
3087 set to addr. By default the 4th IP in the guest network is used,
3088 i.e. x.x.x.4.
3089
3090 In the guest Windows OS, the line:
3091
3092 ::
3093
3094 10.0.2.4 smbserver
3095
3096 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows
3097 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows
3098 NT/2000).
3099
3100 Then ``dir`` can be accessed in ``\\smbserver\qemu``.
3101
3102 Note that a SAMBA server must be installed on the host OS.
3103
3104 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport``
3105 Redirect incoming TCP or UDP connections to the host port
3106 hostport to the guest IP address guestaddr on guest port
3107 guestport. If guestaddr is not specified, its value is x.x.x.15
3108 (default first address given by the built-in DHCP server). By
3109 specifying hostaddr, the rule can be bound to a specific host
3110 interface. If no connection type is set, TCP is used. This
3111 option can be given multiple times.
3112
3113 For example, to redirect host X11 connection from screen 1 to
3114 guest screen 0, use the following:
3115
Peter Maydell09ce5f22020-02-28 15:36:13 +00003116 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003117
3118 # on the host
3119 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
3120 # this host xterm should open in the guest X11 server
3121 xterm -display :1
3122
3123 To redirect telnet connections from host port 5555 to telnet
3124 port on the guest, use the following:
3125
Peter Maydell09ce5f22020-02-28 15:36:13 +00003126 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003127
3128 # on the host
3129 |qemu_system| -nic user,hostfwd=tcp::5555-:23
3130 telnet localhost 5555
3131
3132 Then when you use on the host ``telnet localhost 5555``, you
3133 connect to the guest telnet server.
3134
3135 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command``
3136 Forward guest TCP connections to the IP address server on port
3137 port to the character device dev or to a program executed by
3138 cmd:command which gets spawned for each connection. This option
3139 can be given multiple times.
3140
3141 You can either use a chardev directly and have that one used
3142 throughout QEMU's lifetime, like in the following example:
3143
Peter Maydell09ce5f22020-02-28 15:36:13 +00003144 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003145
3146 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
3147 # the guest accesses it
3148 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
3149
3150 Or you can execute a command on every TCP connection established
3151 by the guest, so that QEMU behaves similar to an inetd process
3152 for that virtual server:
3153
Peter Maydell09ce5f22020-02-28 15:36:13 +00003154 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003155
3156 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
3157 # and connect the TCP stream to its stdin/stdout
3158 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
3159
3160``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]``
3161 Configure a host TAP network backend with ID id.
3162
3163 Use the network script file to configure it and the network script
3164 dfile to deconfigure it. If name is not provided, the OS
3165 automatically provides one. The default network configure script is
3166 ``/etc/qemu-ifup`` and the default network deconfigure script is
3167 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to
3168 disable script execution.
3169
3170 If running QEMU as an unprivileged user, use the network helper
Tianjia Zhang8d73ec82020-07-27 12:59:25 +08003171 to configure the TAP interface and attach it to the bridge.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003172 The default network helper executable is
3173 ``/path/to/qemu-bridge-helper`` and the default bridge device is
3174 ``br0``.
3175
3176 ``fd``\ =h can be used to specify the handle of an already opened
3177 host TAP interface.
3178
3179 Examples:
3180
Peter Maydell09ce5f22020-02-28 15:36:13 +00003181 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003182
3183 #launch a QEMU instance with the default network script
3184 |qemu_system| linux.img -nic tap
3185
Peter Maydell09ce5f22020-02-28 15:36:13 +00003186 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003187
3188 #launch a QEMU instance with two NICs, each one connected
3189 #to a TAP device
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003190 |qemu_system| linux.img \\
3191 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003192 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
3193
Peter Maydell09ce5f22020-02-28 15:36:13 +00003194 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003195
3196 #launch a QEMU instance with the default network helper to
3197 #connect a TAP device to bridge br0
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003198 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003199 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
3200
3201``-netdev bridge,id=id[,br=bridge][,helper=helper]``
3202 Connect a host TAP network interface to a host bridge device.
3203
3204 Use the network helper helper to configure the TAP interface and
3205 attach it to the bridge. The default network helper executable is
3206 ``/path/to/qemu-bridge-helper`` and the default bridge device is
3207 ``br0``.
3208
3209 Examples:
3210
Peter Maydell09ce5f22020-02-28 15:36:13 +00003211 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003212
3213 #launch a QEMU instance with the default network helper to
3214 #connect a TAP device to bridge br0
3215 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
3216
Peter Maydell09ce5f22020-02-28 15:36:13 +00003217 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003218
3219 #launch a QEMU instance with the default network helper to
3220 #connect a TAP device to bridge qemubr0
3221 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
3222
3223``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]``
3224 This host network backend can be used to connect the guest's network
3225 to another QEMU virtual machine using a TCP socket connection. If
3226 ``listen`` is specified, QEMU waits for incoming connections on port
3227 (host is optional). ``connect`` is used to connect to another QEMU
3228 instance using the ``listen`` option. ``fd``\ =h specifies an
3229 already opened TCP socket.
3230
3231 Example:
3232
Peter Maydell09ce5f22020-02-28 15:36:13 +00003233 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003234
3235 # launch a first QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003236 |qemu_system| linux.img \\
3237 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003238 -netdev socket,id=n1,listen=:1234
3239 # connect the network of this instance to the network of the first instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003240 |qemu_system| linux.img \\
3241 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003242 -netdev socket,id=n2,connect=127.0.0.1:1234
3243
3244``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]``
3245 Configure a socket host network backend to share the guest's network
3246 traffic with another QEMU virtual machines using a UDP multicast
3247 socket, effectively making a bus for every QEMU with same multicast
3248 address maddr and port. NOTES:
3249
3250 1. Several QEMU can be running on different hosts and share same bus
3251 (assuming correct multicast setup for these hosts).
3252
3253 2. mcast support is compatible with User Mode Linux (argument
3254 ``ethN=mcast``), see http://user-mode-linux.sf.net.
3255
3256 3. Use ``fd=h`` to specify an already opened UDP multicast socket.
3257
3258 Example:
3259
Peter Maydell09ce5f22020-02-28 15:36:13 +00003260 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003261
3262 # launch one QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003263 |qemu_system| linux.img \\
3264 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003265 -netdev socket,id=n1,mcast=230.0.0.1:1234
3266 # launch another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003267 |qemu_system| linux.img \\
3268 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003269 -netdev socket,id=n2,mcast=230.0.0.1:1234
3270 # launch yet another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003271 |qemu_system| linux.img \\
3272 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003273 -netdev socket,id=n3,mcast=230.0.0.1:1234
3274
3275 Example (User Mode Linux compat.):
3276
Peter Maydell09ce5f22020-02-28 15:36:13 +00003277 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003278
3279 # launch QEMU instance (note mcast address selected is UML's default)
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003280 |qemu_system| linux.img \\
3281 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003282 -netdev socket,id=n1,mcast=239.192.168.1:1102
3283 # launch UML
3284 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
3285
3286 Example (send packets from host's 1.2.3.4):
3287
3288 .. parsed-literal::
3289
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003290 |qemu_system| linux.img \\
3291 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003292 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
3293
Daniil Tatianinc40e9622024-10-25 10:35:24 +03003294``-netdev stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port[,to=maxport][,numeric=on|off][,keep-alive=on|off][,mptcp=on|off][,addr.ipv4=on|off][,addr.ipv6=on|off][,reconnect-ms=milliseconds]``
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003295 Configure a network backend to connect to another QEMU virtual machine or a proxy using a TCP/IP socket.
3296
3297 ``server=on|off``
3298 if ``on`` create a server socket
3299
3300 ``addr.host=host,addr.port=port``
3301 socket address to listen on (server=on) or connect to (server=off)
3302
3303 ``to=maxport``
3304 if present, this is range of possible addresses, with port between ``port`` and ``maxport``.
3305
3306 ``numeric=on|off``
3307 if ``on`` ``host`` and ``port`` are guaranteed to be numeric, otherwise a name resolution should be attempted (default: ``off``)
3308
3309 ``keep-alive=on|off``
3310 enable keep-alive when connecting to this socket. Not supported for passive sockets.
3311
3312 ``mptcp=on|off``
3313 enable multipath TCP
3314
3315 ``ipv4=on|off``
3316 whether to accept IPv4 addresses, default to try both IPv4 and IPv6
3317
3318 ``ipv6=on|off``
3319 whether to accept IPv6 addresses, default to try both IPv4 and IPv6
3320
Daniil Tatianin96e610b2024-10-25 10:35:25 +03003321 ``reconnect-ms=milliseconds``
3322 for a client socket, if a socket is disconnected, then attempt a reconnect after the given number of milliseconds.
Laurent Vivierf6a31582024-07-04 14:48:34 +02003323 Setting this to zero disables this function. (default: 0)
3324
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003325 Example (two guests connected using a TCP/IP socket):
3326
3327 .. parsed-literal::
3328
3329 # first VM
3330 |qemu_system| linux.img \\
3331 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3332 -netdev stream,id=net0,server=on,addr.type=inet,addr.host=localhost,addr.port=1234
3333 # second VM
3334 |qemu_system| linux.img \\
3335 -device virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
Daniil Tatianinc40e9622024-10-25 10:35:24 +03003336 -netdev stream,id=net0,server=off,addr.type=inet,addr.host=localhost,addr.port=1234,reconnect-ms=5000
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003337
Daniil Tatianinc40e9622024-10-25 10:35:24 +03003338``-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect-ms=milliseconds]``
Laurent Vivier178413a2024-07-04 14:48:32 +02003339 Configure a network backend to connect to another QEMU virtual machine or a proxy using a stream oriented unix domain socket.
3340
3341 ``server=on|off``
3342 if ``on`` create a server socket
3343
3344 ``addr.path=path``
3345 filesystem path to use
3346
3347 ``abstract=on|off``
3348 if ``on``, this is a Linux abstract socket address.
3349
3350 ``tight=on|off``
3351 if false, pad an abstract socket address with enough null bytes to make it fill struct sockaddr_un member sun_path.
3352
Daniil Tatianinc40e9622024-10-25 10:35:24 +03003353 ``reconnect-ms=milliseconds``
3354 for a client socket, if a socket is disconnected, then attempt a reconnect after the given number of milliseconds.
Laurent Vivierf6a31582024-07-04 14:48:34 +02003355 Setting this to zero disables this function. (default: 0)
3356
Laurent Vivier178413a2024-07-04 14:48:32 +02003357 Example (using passt as a replacement of -netdev user):
3358
3359 .. parsed-literal::
3360
3361 # start passt server as a non privileged user
3362 passt
3363 UNIX domain socket bound at /tmp/passt_1.socket
3364 # start QEMU to connect to passt
3365 |qemu_system| linux.img \\
3366 -device virtio-net,netdev=net0 \\
3367 -netdev stream,id=net0,server=off,addr.type=unix,addr.path=/tmp/passt_1.socket
3368
3369 Example (two guests connected using a stream oriented unix domain socket):
3370
3371 .. parsed-literal::
3372
3373 # first VM
3374 |qemu_system| linux.img \\
3375 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3376 netdev stream,id=net0,server=on,addr.type=unix,addr.path=/tmp/qemu0
3377 # second VM
3378 |qemu_system| linux.img \\
3379 -device virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
Daniil Tatianinc40e9622024-10-25 10:35:24 +03003380 -netdev stream,id=net0,server=off,addr.type=unix,addr.path=/tmp/qemu0,reconnect-ms=5000
Laurent Vivier178413a2024-07-04 14:48:32 +02003381
Daniil Tatianinc40e9622024-10-25 10:35:24 +03003382``-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect-ms=milliseconds]``
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003383 Configure a network backend to connect to another QEMU virtual machine or a proxy using a stream oriented socket file descriptor.
3384
3385 ``server=on|off``
3386 if ``on`` create a server socket
3387
3388 ``addr.str=file-descriptor``
3389 file descriptor number to use as a socket
3390
Daniil Tatianin96e610b2024-10-25 10:35:25 +03003391 ``reconnect-ms=milliseconds``
3392 for a client socket, if a socket is disconnected, then attempt a reconnect after the given number of milliseconds.
Laurent Vivierf6a31582024-07-04 14:48:34 +02003393 Setting this to zero disables this function. (default: 0)
3394
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003395``-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]``
3396 Configure a network backend to connect to a multicast address.
3397
3398 ``remote.host=maddr,remote.port=port``
3399 multicast address
3400
3401 ``local.host=addr``
3402 specify the host address to send packets from
3403
3404 Example:
3405
3406 .. parsed-literal::
3407
3408 # launch one QEMU instance
3409 |qemu_system| linux.img \\
3410 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3411 -netdev dgram,id=net0,remote.type=inet,remote.host=224.0.0.1,remote.port=1234
3412 # launch another QEMU instance on same "bus"
3413 |qemu_system| linux.img \\
3414 -device virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
3415 -netdev dgram,id=net0,remote.type=inet,remote.host=224.0.0.1,remote.port=1234
3416 # launch yet another QEMU instance on same "bus"
3417 |qemu_system| linux.img \\
3418 -device virtio-net,netdev=net0,mac=52:54:00:12:34:58 \\
3419 -netdev dgram,id=net0,remote.type=inet,remote.host=224.0.0.1,remote.port=1234
3420
3421``-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]``
3422 Configure a network backend to connect to a multicast address using a UDP socket file descriptor.
3423
3424 ``remote.host=maddr,remote.port=port``
3425 multicast address
3426
3427 ``local.str=file-descriptor``
3428 File descriptor to use to send packets
3429
3430``-netdev dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]``
3431 Configure a network backend to connect to another QEMU virtual
3432 machine or a proxy using a datagram oriented unix domain socket.
3433
3434 ``local.host=addr,local.port=port``
3435 IP address to use to send the packets from
3436
3437 ``remote.host=addr,remote.port=port``
3438 Destination IP address
3439
3440 Example (two guests connected using an UDP/IP socket):
3441
3442 .. parsed-literal::
3443
3444 # first VM
3445 |qemu_system| linux.img \\
3446 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3447 -netdev dgram,id=net0,local.type=inet,local.host=localhost,local.port=1234,remote.type=inet,remote.host=localhost,remote.port=1235
3448 # second VM
3449 |qemu_system| linux.img \\
3450 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3451 -netdev dgram,id=net0,local.type=inet,local.host=localhost,local.port=1235,remote.type=inet,remote.host=localhost,remote.port=1234
3452
Laurent Vivier8e676802024-07-04 14:48:33 +02003453``-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]``
3454 Configure a network backend to connect to another QEMU virtual
3455 machine or a proxy using a datagram oriented unix socket.
3456
3457 ``local.path=path``
3458 filesystem path to use to bind the socket
3459
3460 ``remote.path=path``
3461 filesystem path to use as a destination (see sendto(2))
3462
3463 Example (two guests connected using an UDP/UNIX socket):
3464
3465 .. parsed-literal::
3466
3467 # first VM
3468 |qemu_system| linux.img \\
3469 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3470 -netdev dgram,id=net0,local.type=unix,local.path=/tmp/qemu0,remote.type=unix,remote.path=/tmp/qemu1
3471 # second VM
3472 |qemu_system| linux.img \\
3473 -device virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
3474 -netdev dgram,id=net0,local.type=unix,local.path=/tmp/qemu1,remote.type=unix,remote.path=/tmp/qemu0
3475
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003476``-netdev dgram,id=str,local.type=fd,local.str=file-descriptor``
3477 Configure a network backend to connect to another QEMU virtual
3478 machine or a proxy using a datagram oriented socket file descriptor.
3479
3480 ``local.str=file-descriptor``
3481 File descriptor to use to send packets
3482
Zhao Liucb8de742024-07-08 17:26:30 +08003483``-netdev l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6=on|off][,udp=on|off][,cookie64=on|off][,counter=on|off][,pincounter=on|off][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003484 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931)
3485 is a popular protocol to transport Ethernet (and other Layer 2) data
3486 frames between two systems. It is present in routers, firewalls and
3487 the Linux kernel (from version 3.3 onwards).
3488
3489 This transport allows a VM to communicate to another VM, router or
3490 firewall directly.
3491
3492 ``src=srcaddr``
3493 source address (mandatory)
3494
3495 ``dst=dstaddr``
3496 destination address (mandatory)
3497
Zhao Liucb8de742024-07-08 17:26:30 +08003498 ``udp=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003499 select udp encapsulation (default is ip).
3500
3501 ``srcport=srcport``
3502 source udp port.
3503
3504 ``dstport=dstport``
3505 destination udp port.
3506
Zhao Liucb8de742024-07-08 17:26:30 +08003507 ``ipv6=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003508 force v6, otherwise defaults to v4.
3509
3510 ``rxcookie=rxcookie``; \ ``txcookie=txcookie``
3511 Cookies are a weak form of security in the l2tpv3 specification.
3512 Their function is mostly to prevent misconfiguration. By default
3513 they are 32 bit.
3514
Zhao Liucb8de742024-07-08 17:26:30 +08003515 ``cookie64=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003516 Set cookie size to 64 bit instead of the default 32
3517
3518 ``counter=off``
3519 Force a 'cut-down' L2TPv3 with no counter as in
3520 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
3521
3522 ``pincounter=on``
3523 Work around broken counter handling in peer. This may also help
3524 on networks which have packet reorder.
3525
3526 ``offset=offset``
3527 Add an extra offset between header and data
3528
3529 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to
3530 the bridge br-lan on the remote Linux host 1.2.3.4:
3531
Peter Maydell09ce5f22020-02-28 15:36:13 +00003532 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003533
3534 # Setup tunnel on linux host using raw ip as encapsulation
3535 # on 1.2.3.4
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003536 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003537 encap udp udp_sport 16384 udp_dport 16384
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003538 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003539 0xFFFFFFFF peer_session_id 0xFFFFFFFF
3540 ifconfig vmtunnel0 mtu 1500
3541 ifconfig vmtunnel0 up
3542 brctl addif br-lan vmtunnel0
3543
3544
3545 # on 4.3.2.1
3546 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
3547
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003548 |qemu_system| linux.img -device e1000,netdev=n1 \\
Zhao Liucb8de742024-07-08 17:26:30 +08003549 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp=on,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter=on
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003550
3551``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]``
3552 Configure VDE backend to connect to PORT n of a vde switch running
3553 on host and listening for incoming connections on socketpath. Use
3554 GROUP groupname and MODE octalmode to change default ownership and
3555 permissions for communication port. This option is only available if
3556 QEMU has been compiled with vde support enabled.
3557
3558 Example:
3559
Peter Maydell09ce5f22020-02-28 15:36:13 +00003560 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003561
3562 # launch vde switch
3563 vde_switch -F -sock /tmp/myswitch
3564 # launch QEMU instance
3565 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch
3566
Ilya Maximetscb039ef2023-09-13 20:34:37 +02003567``-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off][,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]``
3568 Configure AF_XDP backend to connect to a network interface 'name'
3569 using AF_XDP socket. A specific program attach mode for a default
3570 XDP program can be forced with 'mode', defaults to best-effort,
3571 where the likely most performant mode will be in use. Number of queues
3572 'n' should generally match the number or queues in the interface,
3573 defaults to 1. Traffic arriving on non-configured device queues will
3574 not be delivered to the network backend.
3575
3576 .. parsed-literal::
3577
3578 # set number of queues to 4
3579 ethtool -L eth0 combined 4
3580 # launch QEMU instance
3581 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
3582 -netdev af-xdp,id=n1,ifname=eth0,queues=4
3583
3584 'start-queue' option can be specified if a particular range of queues
3585 [m, m + n] should be in use. For example, this is may be necessary in
3586 order to use certain NICs in native mode. Kernel allows the driver to
3587 create a separate set of XDP queues on top of regular ones, and only
3588 these queues can be used for AF_XDP sockets. NICs that work this way
3589 may also require an additional traffic redirection with ethtool to these
3590 special queues.
3591
3592 .. parsed-literal::
3593
3594 # set number of queues to 1
3595 ethtool -L eth0 combined 1
3596 # redirect all the traffic to the second queue (id: 1)
3597 # note: drivers may require non-empty key/mask pair.
3598 ethtool -N eth0 flow-type ether \\
3599 dst 00:00:00:00:00:00 m FF:FF:FF:FF:FF:FE action 1
3600 ethtool -N eth0 flow-type ether \\
3601 dst 00:00:00:00:00:01 m FF:FF:FF:FF:FF:FE action 1
3602 # launch QEMU instance
3603 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
3604 -netdev af-xdp,id=n1,ifname=eth0,queues=1,start-queue=1
3605
3606 XDP program can also be loaded externally. In this case 'inhibit' option
3607 should be set to 'on' and 'sock-fds' provided with file descriptors for
3608 already open but not bound XDP sockets already added to a socket map for
3609 corresponding queues. One socket per queue.
3610
3611 .. parsed-literal::
3612
3613 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
3614 -netdev af-xdp,id=n1,ifname=eth0,queues=3,inhibit=on,sock-fds=15:16:17
3615
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003616``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]``
3617 Establish a vhost-user netdev, backed by a chardev id. The chardev
3618 should be a unix domain socket backed one. The vhost-user uses a
3619 specifically defined protocol to pass vhost ioctl replacement
3620 messages to an application on the other end of the socket. On
3621 non-MSIX guests, the feature can be forced with vhostforce. Use
3622 'queues=n' to specify the number of queues to be created for
3623 multiqueue vhost-user.
3624
3625 Example:
3626
3627 ::
3628
3629 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
3630 -numa node,memdev=mem \
3631 -chardev socket,id=chr0,path=/path/to/socket \
3632 -netdev type=vhost-user,id=net0,chardev=chr0 \
3633 -device virtio-net-pci,netdev=net0
3634
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07003635``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]``
Cindy Lu108a6482020-07-01 22:55:37 +08003636 Establish a vhost-vdpa netdev.
3637
3638 vDPA device is a device that uses a datapath which complies with
3639 the virtio specifications with a vendor specific control path.
3640 vDPA devices can be both physically located on the hardware or
3641 emulated by software.
3642
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003643``-netdev hubport,id=id,hubid=hubid[,netdev=nd]``
3644 Create a hub port on the emulated hub with ID hubid.
3645
3646 The hubport netdev lets you connect a NIC to a QEMU emulated hub
3647 instead of a single netdev. Alternatively, you can also connect the
3648 hubport to another netdev with ID nd by using the ``netdev=nd``
3649 option.
3650
3651``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]``
3652 Legacy option to configure or create an on-board (or machine
3653 default) Network Interface Card(NIC) and connect it either to the
3654 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd.
3655 If model is omitted, then the default NIC model associated with the
3656 machine type is used. Note that the default NIC model may change in
3657 future QEMU releases, so it is highly recommended to always specify
3658 a model. Optionally, the MAC address can be changed to mac, the
3659 device address set to addr (PCI cards only), and a name can be
3660 assigned for use in monitor commands. Optionally, for PCI cards, you
3661 can specify the number v of MSI-X vectors that the card should have;
3662 this option currently only affects virtio cards; set v = 0 to
3663 disable MSI-X. If no ``-net`` option is specified, a single NIC is
3664 created. QEMU can emulate several different models of network card.
3665 Use ``-net nic,model=help`` for a list of available devices for your
3666 target.
3667
3668``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]``
3669 Configure a host network backend (with the options corresponding to
3670 the same ``-netdev`` option) and connect it to the emulated hub 0
3671 (the default hub). Use name to specify the name of the hub port.
3672ERST
blueswir15824d652009-03-28 06:44:27 +00003673
Matthew Booth7273a2d2009-10-30 13:41:12 +00003674DEFHEADING()
3675
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003676DEFHEADING(Character device options:)
Matthew Booth7273a2d2009-10-30 13:41:12 +00003677
3678DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
Lin Ma517b3d42016-08-17 01:13:52 +08003679 "-chardev help\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003680 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Markus Armbrusterba858d12021-09-28 09:14:49 +02003681 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n"
Daniil Tatianin96e610b2024-10-25 10:35:25 +03003682 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect-ms=milliseconds][,mux=on|off]\n"
Daniel P. Berrangefd4a5fd2019-03-08 15:21:50 +00003683 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n"
Daniil Tatianin96e610b2024-10-25 10:35:25 +03003684 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect-ms=milliseconds]\n"
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003685 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003686 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003687 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003688 " [,logfile=PATH][,logappend=on|off]\n"
3689 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003690 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003691 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3692 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
Peter Maydell5b18a6b2023-04-13 16:07:24 +01003693 "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003694 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003695#ifdef _WIN32
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003696 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3697 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003698#else
Octavian Purdilab74cb872024-08-05 18:07:35 -07003699 "-chardev pty,id=id[,path=path][,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003700 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003701#endif
3702#ifdef CONFIG_BRLAPI
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003703 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003704#endif
3705#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
3706 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003707 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003708#endif
3709#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003710 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003711#endif
Alon Levycbcc6332011-01-19 10:49:50 +02003712#if defined(CONFIG_SPICE)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003713 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
3714 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
Alon Levycbcc6332011-01-19 10:49:50 +02003715#endif
Blue Swirlad960902010-03-29 19:23:52 +00003716 , QEMU_ARCH_ALL
Matthew Booth7273a2d2009-10-30 13:41:12 +00003717)
3718
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003719SRST
3720The general form of a character device option is:
3721
3722``-chardev backend,id=id[,mux=on|off][,options]``
3723 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``,
3724 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``,
Paolo Bonzini6f9f6302022-12-16 10:56:53 +01003725 ``pty``, ``stdio``, ``braille``, ``parallel``,
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003726 ``spicevmc``, ``spiceport``. The specific backend will determine the
3727 applicable options.
3728
3729 Use ``-chardev help`` to print all available chardev backend types.
3730
3731 All devices must have an id, which can be any string up to 127
3732 characters long. It is used to uniquely identify this device in
3733 other command line directives.
3734
3735 A character device may be used in multiplexing mode by multiple
3736 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is
3737 a "1:N" device, and here the "1" end is your specified chardev
3738 backend, and the "N" end is the various parts of QEMU that can talk
3739 to a chardev. If you create a chardev with ``id=myid`` and
3740 ``mux=on``, QEMU will create a multiplexer with your specified ID,
3741 and you can then configure multiple front ends to use that chardev
3742 ID for their input/output. Up to four different front ends can be
3743 connected to a single multiplexed chardev. (Without multiplexing
3744 enabled, a chardev can only be used by a single front end.) For
3745 instance you could use this to allow a single stdio chardev to be
3746 used by two serial ports and the QEMU monitor:
3747
3748 ::
3749
3750 -chardev stdio,mux=on,id=char0 \
3751 -mon chardev=char0,mode=readline \
3752 -serial chardev:char0 \
3753 -serial chardev:char0
3754
3755 You can have more than one multiplexer in a system configuration;
3756 for instance you could have a TCP port multiplexed between UART 0
3757 and UART 1, and stdio multiplexed between the QEMU monitor and a
3758 parallel port:
3759
3760 ::
3761
3762 -chardev stdio,mux=on,id=char0 \
3763 -mon chardev=char0,mode=readline \
3764 -parallel chardev:char0 \
3765 -chardev tcp,...,mux=on,id=char1 \
3766 -serial chardev:char1 \
3767 -serial chardev:char1
3768
3769 When you're using a multiplexed character device, some escape
Thomas Huth923e9312020-11-16 15:47:36 +01003770 sequences are interpreted in the input. See the chapter about
3771 :ref:`keys in the character backend multiplexer` in the
3772 System Emulation Users Guide for more details.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003773
3774 Note that some other command line options may implicitly create
3775 multiplexed character backends; for instance ``-serial mon:stdio``
3776 creates a multiplexed stdio backend connected to the serial port and
3777 the QEMU monitor, and ``-nographic`` also multiplexes the console
3778 and the monitor to stdio.
3779
3780 There is currently no support for multiplexing in the other
3781 direction (where a single QEMU front end takes input and output from
3782 multiple chardevs).
3783
3784 Every backend supports the ``logfile`` option, which supplies the
3785 path to a file to record all data transmitted via the backend. The
3786 ``logappend`` option controls whether the log file will be truncated
3787 or appended to when opened.
3788
3789The available backends are:
3790
3791``-chardev null,id=id``
3792 A void device. This device will not emit any data, and will drop any
3793 data it receives. The null backend does not take any options.
3794
Daniil Tatianin96e610b2024-10-25 10:35:25 +03003795``-chardev socket,id=id[,TCP options or unix options][,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect-ms=milliseconds][,tls-creds=id][,tls-authz=id]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003796 Create a two-way stream socket, which can be either a TCP or a unix
3797 socket. A unix socket will be created if ``path`` is specified.
3798 Behaviour is undefined if TCP options are specified for a unix
3799 socket.
3800
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003801 ``server=on|off`` specifies that the socket shall be a listening socket.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003802
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003803 ``wait=on|off`` specifies that QEMU should not block waiting for a client
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003804 to connect to a listening socket.
3805
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003806 ``telnet=on|off`` specifies that traffic on the socket should interpret
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003807 telnet escape sequences.
3808
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003809 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003810 communication.
3811
Daniil Tatianin96e610b2024-10-25 10:35:25 +03003812 ``reconnect-ms`` sets the timeout for reconnecting on non-server
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003813 sockets when the remote end goes away. qemu will delay this many
Daniil Tatianin96e610b2024-10-25 10:35:25 +03003814 milliseconds and then attempt to reconnect. Zero disables reconnecting,
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003815 and is the default.
3816
3817 ``tls-creds`` requests enablement of the TLS protocol for
3818 encryption, and specifies the id of the TLS credentials to use for
3819 the handshake. The credentials must be previously created with the
3820 ``-object tls-creds`` argument.
3821
3822 ``tls-auth`` provides the ID of the QAuthZ authorization object
3823 against which the client's x509 distinguished name will be
3824 validated. This object is only resolved at time of use, so can be
3825 deleted and recreated on the fly while the chardev server is active.
3826 If missing, it will default to denying access.
3827
3828 TCP and unix socket options are given below:
3829
Paolo Bonzinia9b13152021-02-25 11:47:52 +01003830 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003831 ``host`` for a listening socket specifies the local address to
3832 be bound. For a connecting socket species the remote host to
3833 connect to. ``host`` is optional for listening sockets. If not
3834 specified it defaults to ``0.0.0.0``.
3835
3836 ``port`` for a listening socket specifies the local port to be
3837 bound. For a connecting socket specifies the port on the remote
3838 host to connect to. ``port`` can be given as either a port
3839 number or a service name. ``port`` is required.
3840
3841 ``to`` is only relevant to listening sockets. If it is
3842 specified, and ``port`` cannot be bound, QEMU will attempt to
3843 bind to subsequent ports up to and including ``to`` until it
3844 succeeds. ``to`` must be specified as a port number.
3845
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003846 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4
3847 or IPv6 must be used. If neither is specified the socket may
3848 use either protocol.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003849
Paolo Bonzinia9b13152021-02-25 11:47:52 +01003850 ``nodelay=on|off`` disables the Nagle algorithm.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003851
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003852 ``unix options: path=path[,abstract=on|off][,tight=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003853 ``path`` specifies the local path of the unix socket. ``path``
3854 is required.
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003855 ``abstract=on|off`` specifies the use of the abstract socket namespace,
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003856 rather than the filesystem. Optional, defaults to false.
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003857 ``tight=on|off`` sets the socket length of abstract sockets to their minimum,
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003858 rather than the full sun_path length. Optional, defaults to true.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003859
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003860``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4=on|off][,ipv6=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003861 Sends all traffic from the guest to a remote host over UDP.
3862
3863 ``host`` specifies the remote host to connect to. If not specified
3864 it defaults to ``localhost``.
3865
3866 ``port`` specifies the port on the remote host to connect to.
3867 ``port`` is required.
3868
3869 ``localaddr`` specifies the local address to bind to. If not
3870 specified it defaults to ``0.0.0.0``.
3871
3872 ``localport`` specifies the local port to bind to. If not specified
3873 any available local port will be used.
3874
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003875 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003876 If neither is specified the device may use either protocol.
3877
3878``-chardev msmouse,id=id``
3879 Forward QEMU's emulated msmouse events to the guest. ``msmouse``
3880 does not take any options.
3881
3882``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]``
3883 Connect to a QEMU text console. ``vc`` may optionally be given a
3884 specific size.
3885
3886 ``width`` and ``height`` specify the width and height respectively
3887 of the console, in pixels.
3888
3889 ``cols`` and ``rows`` specify that the console be sized to fit a
3890 text console with the given dimensions.
3891
3892``-chardev ringbuf,id=id[,size=size]``
3893 Create a ring buffer with fixed size ``size``. size must be a power
3894 of two and defaults to ``64K``.
3895
Peter Maydell5b18a6b2023-04-13 16:07:24 +01003896``-chardev file,id=id,path=path[,input-path=input-path]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003897 Log all traffic received from the guest to a file.
3898
3899 ``path`` specifies the path of the file to be opened. This file will
3900 be created if it does not already exist, and overwritten if it does.
3901 ``path`` is required.
3902
Peter Maydell5b18a6b2023-04-13 16:07:24 +01003903 If ``input-path`` is specified, this is the path of a second file
3904 which will be used for input. If ``input-path`` is not specified,
3905 no input will be available from the chardev.
3906
3907 Note that ``input-path`` is not supported on Windows hosts.
3908
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003909``-chardev pipe,id=id,path=path``
3910 Create a two-way connection to the guest. The behaviour differs
3911 slightly between Windows hosts and other hosts:
3912
3913 On Windows, a single duplex pipe will be created at
3914 ``\\.pipe\path``.
3915
3916 On other hosts, 2 pipes will be created called ``path.in`` and
3917 ``path.out``. Data written to ``path.in`` will be received by the
3918 guest. Data written by the guest can be read from ``path.out``. QEMU
3919 will not create these fifos, and requires them to be present.
3920
3921 ``path`` forms part of the pipe path as described above. ``path`` is
3922 required.
3923
3924``-chardev console,id=id``
3925 Send traffic from the guest to QEMU's standard output. ``console``
3926 does not take any options.
3927
3928 ``console`` is only available on Windows hosts.
3929
3930``-chardev serial,id=id,path=path``
3931 Send traffic from the guest to a serial device on the host.
3932
3933 On Unix hosts serial will actually accept any tty device, not only
3934 serial lines.
3935
3936 ``path`` specifies the name of the serial device to open.
3937
Octavian Purdilab74cb872024-08-05 18:07:35 -07003938``-chardev pty,id=id[,path=path]``
3939 Create a new pseudo-terminal on the host and connect to it.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003940
3941 ``pty`` is not available on Windows hosts.
3942
Octavian Purdilab74cb872024-08-05 18:07:35 -07003943 If ``path`` is specified, QEMU will create a symbolic link at
3944 that location which points to the new PTY device.
3945
3946 This avoids having to make QMP or HMP monitor queries to find out
3947 what the new PTY device path is.
3948
3949 Note that while QEMU will remove the symlink when it exits
3950 gracefully, it will not do so in case of crashes or on certain
3951 startup errors. It is recommended that the user checks and removes
3952 the symlink after QEMU terminates to account for this.
3953
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003954``-chardev stdio,id=id[,signal=on|off]``
3955 Connect to standard input and standard output of the QEMU process.
3956
3957 ``signal`` controls if signals are enabled on the terminal, that
3958 includes exiting QEMU with the key sequence Control-c. This option
3959 is enabled by default, use ``signal=off`` to disable it.
3960
3961``-chardev braille,id=id``
3962 Connect to a local BrlAPI server. ``braille`` does not take any
3963 options.
3964
Peter Maydell09ce5f22020-02-28 15:36:13 +00003965``-chardev parallel,id=id,path=path``
3966 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003967 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD
3968 hosts.
3969
3970 Connect to a local parallel port.
3971
3972 ``path`` specifies the path to the parallel port device. ``path`` is
3973 required.
3974
3975``-chardev spicevmc,id=id,debug=debug,name=name``
3976 ``spicevmc`` is only available when spice support is built in.
3977
3978 ``debug`` debug level for spicevmc
3979
3980 ``name`` name of spice channel to connect to
3981
3982 Connect to a spice virtual machine channel, such as vdiport.
3983
3984``-chardev spiceport,id=id,debug=debug,name=name``
3985 ``spiceport`` is only available when spice support is built in.
3986
3987 ``debug`` debug level for spicevmc
3988
3989 ``name`` name of spice port to connect to
3990
3991 Connect to a spice port, allowing a Spice client to handle the
3992 traffic identified by a name (preferably a fqdn).
3993ERST
Matthew Booth7273a2d2009-10-30 13:41:12 +00003994
3995DEFHEADING()
3996
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003997#ifdef CONFIG_TPM
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003998DEFHEADING(TPM device options:)
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003999
4000DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
Stefan Berger92dcc232013-02-27 12:47:54 -05004001 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
4002 " use path to provide path to a character device; default is /dev/tpm0\n"
4003 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
Amarnath Vallurif4ede812017-09-29 14:10:20 +03004004 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
4005 "-tpmdev emulator,id=id,chardev=dev\n"
4006 " configure the TPM device using chardev backend\n",
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05004007 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004008SRST
4009The general form of a TPM device option is:
4010
4011``-tpmdev backend,id=id[,options]``
4012 The specific backend type will determine the applicable options. The
4013 ``-tpmdev`` option creates the TPM backend and requires a
4014 ``-device`` option that specifies the TPM frontend interface model.
4015
4016 Use ``-tpmdev help`` to print all available TPM backend types.
4017
4018The available backends are:
4019
4020``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path``
4021 (Linux-host only) Enable access to the host's TPM using the
4022 passthrough driver.
4023
4024 ``path`` specifies the path to the host's TPM device, i.e., on a
4025 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by
4026 default ``/dev/tpm0`` is used.
4027
4028 ``cancel-path`` specifies the path to the host TPM device's sysfs
4029 entry allowing for cancellation of an ongoing TPM command.
4030 ``cancel-path`` is optional and by default QEMU will search for the
4031 sysfs entry to use.
4032
4033 Some notes about using the host's TPM with the passthrough driver:
4034
4035 The TPM device accessed by the passthrough driver must not be used
4036 by any other application on the host.
4037
4038 Since the host's firmware (BIOS/UEFI) has already initialized the
4039 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize
4040 the TPM again and may therefore not show a TPM-specific menu that
4041 would otherwise allow the user to configure the TPM, e.g., allow the
4042 user to enable/disable or activate/deactivate the TPM. Further, if
4043 TPM ownership is released from within a VM then the host's TPM will
4044 get disabled and deactivated. To enable and activate the TPM again
4045 afterwards, the host has to be rebooted and the user is required to
4046 enter the firmware's menu to enable and activate the TPM. If the TPM
4047 is left disabled and/or deactivated most TPM commands will fail.
4048
4049 To create a passthrough TPM use the following two options:
4050
4051 ::
4052
4053 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
4054
4055 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by
4056 ``tpmdev=tpm0`` in the device option.
4057
4058``-tpmdev emulator,id=id,chardev=dev``
4059 (Linux-host only) Enable access to a TPM emulator using Unix domain
4060 socket based chardev backend.
4061
4062 ``chardev`` specifies the unique ID of a character device backend
4063 that provides connection to the software TPM server.
4064
4065 To create a TPM emulator backend device with chardev socket backend:
4066
4067 ::
4068
4069 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
4070ERST
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05004071
4072DEFHEADING()
4073
4074#endif
4075
Alex Bennée1235cf72022-07-25 15:05:20 +01004076DEFHEADING(Boot Image or Kernel specific:)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004077SRST
Alex Bennée1235cf72022-07-25 15:05:20 +01004078There are broadly 4 ways you can boot a system with QEMU.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004079
Alex Bennée1235cf72022-07-25 15:05:20 +01004080 - specify a firmware and let it control finding a kernel
4081 - specify a firmware and pass a hint to the kernel to boot
4082 - direct kernel image boot
4083 - manually load files into the guest's address space
4084
4085The third method is useful for quickly testing kernels but as there is
4086no firmware to pass configuration information to the kernel the
4087hardware must either be probeable, the kernel built for the exact
4088configuration or passed some configuration data (e.g. a DTB blob)
4089which tells the kernel what drivers it needs. This exact details are
4090often hardware specific.
4091
4092The final method is the most generic way of loading images into the
4093guest address space and used mostly for ``bare metal`` type
4094development where the reset vectors of the processor are taken into
4095account.
4096
4097ERST
4098
4099SRST
4100
4101For x86 machines and some other architectures ``-bios`` will generally
4102do the right thing with whatever it is given. For other machines the
4103more strict ``-pflash`` option needs an image that is sized for the
4104flash device for the given machine type.
4105
4106Please see the :ref:`system-targets-ref` section of the manual for
4107more detailed documentation.
4108
4109ERST
4110
4111DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
4112 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
4113SRST
4114``-bios file``
4115 Set the filename for the BIOS.
4116ERST
4117
4118DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
4119 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
4120SRST
4121``-pflash file``
4122 Use file as a parallel flash image.
4123ERST
4124
4125SRST
4126
4127The kernel options were designed to work with Linux kernels although
4128other things (like hypervisors) can be packaged up as a kernel
4129executable image. The exact format of a executable image is usually
4130architecture specific.
4131
4132The way in which the kernel is started (what address it is loaded at,
4133what if any information is passed to it via CPU registers, the state
4134of the hardware when it is started, and so on) is also architecture
4135specific. Typically it follows the specification laid down by the
4136Linux kernel for how kernels for that architecture must be started.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004137
4138ERST
blueswir15824d652009-03-28 06:44:27 +00004139
4140DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
Blue Swirlad960902010-03-29 19:23:52 +00004141 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004142SRST
4143``-kernel bzImage``
4144 Use bzImage as kernel image. The kernel can be either a Linux kernel
4145 or in multiboot format.
4146ERST
blueswir15824d652009-03-28 06:44:27 +00004147
Gerd Hoffmanna5bd0442024-09-05 16:12:10 +02004148DEF("shim", HAS_ARG, QEMU_OPTION_shim, \
4149 "-shim shim.efi use 'shim.efi' to boot the kernel\n", QEMU_ARCH_ALL)
4150SRST
4151``-shim shim.efi``
4152 Use 'shim.efi' to boot the kernel
4153ERST
4154
blueswir15824d652009-03-28 06:44:27 +00004155DEF("append", HAS_ARG, QEMU_OPTION_append, \
Blue Swirlad960902010-03-29 19:23:52 +00004156 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004157SRST
4158``-append cmdline``
4159 Use cmdline as kernel command line
4160ERST
blueswir15824d652009-03-28 06:44:27 +00004161
4162DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
Blue Swirlad960902010-03-29 19:23:52 +00004163 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
David Woodhouse1eeb4322024-01-30 19:01:43 +00004164SRST(initrd)
David Woodhousecc9d10b2023-10-19 15:30:23 +01004165
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004166``-initrd file``
4167 Use file as initial ram disk.
4168
4169``-initrd "file1 arg=foo,file2"``
4170 This syntax is only available with multiboot.
4171
David Woodhousecc9d10b2023-10-19 15:30:23 +01004172 Use file1 and file2 as modules and pass ``arg=foo`` as parameter to the
4173 first module. Commas can be provided in module parameters by doubling
4174 them on the command line to escape them:
4175
4176``-initrd "bzImage earlyprintk=xen,,keep root=/dev/xvda1,initrd.img"``
4177 Multiboot only. Use bzImage as the first module with
4178 "``earlyprintk=xen,keep root=/dev/xvda1``" as its command line,
4179 and initrd.img as the second module.
4180
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004181ERST
blueswir15824d652009-03-28 06:44:27 +00004182
Grant Likely412beee2012-03-02 11:56:38 +00004183DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
Peter A. G. Crosthwaite379b5c72012-03-04 21:03:54 +10004184 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004185SRST
4186``-dtb file``
4187 Use file as a device tree binary (dtb) image and pass it to the
4188 kernel on boot.
4189ERST
Grant Likely412beee2012-03-02 11:56:38 +00004190
Alex Bennée1235cf72022-07-25 15:05:20 +01004191SRST
4192
4193Finally you can also manually load images directly into the address
4194space of the guest. This is most useful for developers who already
4195know the layout of their guest and take care to ensure something sane
4196will happen when the reset vector executes.
4197
4198The generic loader can be invoked by using the loader device:
4199
4200``-device loader,addr=<addr>,data=<data>,data-len=<data-len>[,data-be=<data-be>][,cpu-num=<cpu-num>]``
4201
4202there is also the guest loader which operates in a similar way but
4203tweaks the DTB so a hypervisor loaded via ``-kernel`` can find where
4204the guest image is:
4205
4206``-device guest-loader,addr=<addr>[,kernel=<path>,[bootargs=<arguments>]][,initrd=<path>]``
4207
4208ERST
4209
blueswir15824d652009-03-28 06:44:27 +00004210DEFHEADING()
4211
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02004212DEFHEADING(Debug/Expert options:)
blueswir15824d652009-03-28 06:44:27 +00004213
Markus Armbruster6dd75472021-03-18 16:55:10 +01004214DEF("compat", HAS_ARG, QEMU_OPTION_compat,
Markus Armbrusterdbb675c2021-03-18 16:55:19 +01004215 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n"
Markus Armbruster57df0df2021-10-28 12:25:20 +02004216 " Policy for handling deprecated management interfaces\n"
4217 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n"
4218 " Policy for handling unstable management interfaces\n",
Markus Armbruster6dd75472021-03-18 16:55:10 +01004219 QEMU_ARCH_ALL)
4220SRST
4221``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]``
4222 Set policy for handling deprecated management interfaces (experimental):
4223
4224 ``deprecated-input=accept`` (default)
4225 Accept deprecated commands and arguments
4226 ``deprecated-input=reject``
4227 Reject deprecated commands and arguments
Markus Armbrusterdbb675c2021-03-18 16:55:19 +01004228 ``deprecated-input=crash``
4229 Crash on deprecated commands and arguments
Markus Armbruster6dd75472021-03-18 16:55:10 +01004230 ``deprecated-output=accept`` (default)
4231 Emit deprecated command results and events
4232 ``deprecated-output=hide``
4233 Suppress deprecated command results and events
4234
4235 Limitation: covers only syntactic aspects of QMP.
Markus Armbruster57df0df2021-10-28 12:25:20 +02004236
4237``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]``
4238 Set policy for handling unstable management interfaces (experimental):
4239
4240 ``unstable-input=accept`` (default)
4241 Accept unstable commands and arguments
4242 ``unstable-input=reject``
4243 Reject unstable commands and arguments
4244 ``unstable-input=crash``
4245 Crash on unstable commands and arguments
4246 ``unstable-output=accept`` (default)
4247 Emit unstable command results and events
4248 ``unstable-output=hide``
4249 Suppress unstable command results and events
4250
4251 Limitation: covers only syntactic aspects of QMP.
Markus Armbruster6dd75472021-03-18 16:55:10 +01004252ERST
4253
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04004254DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
4255 "-fw_cfg [name=]<name>,file=<file>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02004256 " add named fw_cfg entry with contents from file\n"
Gabriel L. Somlo6407d762015-09-29 12:29:01 -04004257 "-fw_cfg [name=]<name>,string=<str>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02004258 " add named fw_cfg entry with contents from string\n",
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04004259 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004260SRST
4261``-fw_cfg [name=]name,file=file``
4262 Add named fw\_cfg entry with contents from file file.
Yihuan Panfd49b212023-12-13 22:17:07 +08004263 If the filename contains comma, you must double it (for instance,
4264 "file=my,,file" to use file "my,file").
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004265
4266``-fw_cfg [name=]name,string=str``
4267 Add named fw\_cfg entry with contents from string str.
Yihuan Panfd49b212023-12-13 22:17:07 +08004268 If the string contains comma, you must double it (for instance,
4269 "string=my,,string" to use file "my,string").
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004270
4271 The terminating NUL character of the contents of str will not be
4272 included as part of the fw\_cfg item data. To insert contents with
4273 embedded NUL characters, you have to use the file parameter.
4274
4275 The fw\_cfg entries are passed by QEMU through to the guest.
4276
4277 Example:
4278
4279 ::
4280
4281 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
4282
4283 creates an fw\_cfg entry named opt/com.mycompany/blob with contents
4284 from ./my\_blob.bin.
4285ERST
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04004286
blueswir15824d652009-03-28 06:44:27 +00004287DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
Blue Swirlad960902010-03-29 19:23:52 +00004288 "-serial dev redirect the serial port to char device 'dev'\n",
4289 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004290SRST
4291``-serial dev``
4292 Redirect the virtual serial port to host character device dev. The
4293 default device is ``vc`` in graphical mode and ``stdio`` in non
4294 graphical mode.
4295
Steven Shen75583002024-03-05 09:30:16 +08004296 This option can be used several times to simulate multiple serial
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004297 ports.
4298
Peter Maydell747bfaf2024-01-22 16:36:07 +00004299 You can use ``-serial none`` to suppress the creation of default
4300 serial devices.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004301
4302 Available character devices are:
4303
4304 ``vc[:WxH]``
4305 Virtual console. Optionally, a width and height can be given in
4306 pixel with
4307
4308 ::
4309
4310 vc:800x600
4311
4312 It is also possible to specify width or height in characters:
4313
4314 ::
4315
4316 vc:80Cx24C
4317
Octavian Purdilab74cb872024-08-05 18:07:35 -07004318 ``pty[:path]``
4319 [Linux only] Pseudo TTY (a new PTY is automatically allocated).
4320
4321 If ``path`` is specified, QEMU will create a symbolic link at
4322 that location which points to the new PTY device.
4323
4324 This avoids having to make QMP or HMP monitor queries to find
4325 out what the new PTY device path is.
4326
4327 Note that while QEMU will remove the symlink when it exits
4328 gracefully, it will not do so in case of crashes or on certain
4329 startup errors. It is recommended that the user checks and
4330 removes the symlink after QEMU terminates to account for this.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004331
4332 ``none``
Peter Maydell747bfaf2024-01-22 16:36:07 +00004333 No device is allocated. Note that for machine types which
4334 emulate systems where a serial device is always present in
4335 real hardware, this may be equivalent to the ``null`` option,
4336 in that the serial device is still present but all output
4337 is discarded. For boards where the number of serial ports is
4338 truly variable, this suppresses the creation of the device.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004339
4340 ``null``
Peter Maydell747bfaf2024-01-22 16:36:07 +00004341 A guest will see the UART or serial device as present in the
4342 machine, but all output is discarded, and there is no input.
4343 Conceptually equivalent to redirecting the output to ``/dev/null``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004344
4345 ``chardev:id``
4346 Use a named character device defined with the ``-chardev``
4347 option.
4348
4349 ``/dev/XXX``
4350 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial
4351 port parameters are set according to the emulated ones.
4352
4353 ``/dev/parportN``
4354 [Linux only, parallel port only] Use host parallel port N.
4355 Currently SPP and EPP parallel port features can be used.
4356
4357 ``file:filename``
4358 Write output to filename. No character can be read.
4359
4360 ``stdio``
4361 [Unix only] standard input/output
4362
4363 ``pipe:filename``
4364 name pipe filename
4365
4366 ``COMn``
4367 [Windows only] Use host serial port n
4368
4369 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]``
4370 This implements UDP Net Console. When remote\_host or src\_ip
4371 are not specified they default to ``0.0.0.0``. When not using a
4372 specified src\_port a random port is automatically chosen.
4373
4374 If you just want a simple readonly console you can use
4375 ``netcat`` or ``nc``, by starting QEMU with:
4376 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time
4377 QEMU writes something to that port it will appear in the
4378 netconsole session.
4379
4380 If you plan to send characters back via netconsole or you want
4381 to stop and start QEMU a lot of times, you should have QEMU use
4382 the same source port each time by using something like ``-serial
4383 udp::4555@:4556`` to QEMU. Another approach is to use a patched
4384 version of netcat which can listen to a TCP port and send and
4385 receive characters via udp. If you have a patched version of
4386 netcat which activates telnet remote echo and single char
4387 transfer, then you can use the following options to set up a
4388 netcat redirector to allow telnet on port 5555 to access the
4389 QEMU port.
4390
4391 ``QEMU Options:``
4392 -serial udp::4555@:4556
4393
4394 ``netcat options:``
4395 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
4396
4397 ``telnet options:``
4398 localhost 5555
4399
Daniil Tatianinc40e9622024-10-25 10:35:24 +03004400 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect-ms=milliseconds]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004401 The TCP Net Console has two modes of operation. It can send the
4402 serial I/O to a location or wait for a connection from a
4403 location. By default the TCP Net Console is sent to host at the
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004404 port. If you use the ``server=on`` option QEMU will wait for a client
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004405 socket application to connect to the port before continuing,
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004406 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off``
Daniil Tatianinc40e9622024-10-25 10:35:24 +03004407 option disables the Nagle buffering algorithm. The ``reconnect-ms``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004408 option only applies if ``server=no`` is set, if the connection goes
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004409 down it will attempt to reconnect at the given interval. If host
4410 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004411 time is accepted. You can use ``telnet=on`` to connect to the
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004412 corresponding character device.
4413
4414 ``Example to send tcp console to 192.168.0.2 port 4444``
4415 -serial tcp:192.168.0.2:4444
4416
4417 ``Example to listen and wait on port 4444 for connection``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004418 -serial tcp::4444,server=on
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004419
4420 ``Example to not wait and listen on ip 192.168.0.100 port 4444``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004421 -serial tcp:192.168.0.100:4444,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004422
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004423 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004424 The telnet protocol is used instead of raw tcp sockets. The
4425 options work the same as if you had specified ``-serial tcp``.
4426 The difference is that the port acts like a telnet server or
4427 client using telnet option negotiation. This will also allow you
4428 to send the MAGIC\_SYSRQ sequence if you use a telnet that
4429 supports sending the break sequence. Typically in unix telnet
4430 you do it with Control-] and then type "send break" followed by
4431 pressing the enter key.
4432
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004433 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004434 The WebSocket protocol is used instead of raw tcp socket. The
4435 port acts as a WebSocket server. Client mode is not supported.
4436
Daniil Tatianin96e610b2024-10-25 10:35:25 +03004437 ``unix:path[,server=on|off][,wait=on|off][,reconnect-ms=milliseconds]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004438 A unix domain socket is used instead of a tcp socket. The option
4439 works the same as if you had specified ``-serial tcp`` except
4440 the unix domain socket path is used for connections.
4441
4442 ``mon:dev_string``
4443 This is a special option to allow the monitor to be multiplexed
4444 onto another serial port. The monitor is accessed with key
4445 sequence of Control-a and then pressing c. dev\_string should be
4446 any one of the serial devices specified above. An example to
4447 multiplex the monitor onto a telnet server listening on port
4448 4444 would be:
4449
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004450 ``-serial mon:telnet::4444,server=on,wait=off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004451
4452 When the monitor is multiplexed to stdio in this way, Ctrl+C
4453 will not terminate QEMU any more but will be passed to the guest
4454 instead.
4455
4456 ``braille``
4457 Braille device. This will use BrlAPI to display the braille
4458 output on a real or fake device.
4459
4460 ``msmouse``
4461 Three button serial mouse. Configure the guest to use Microsoft
4462 protocol.
4463ERST
blueswir15824d652009-03-28 06:44:27 +00004464
4465DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
Blue Swirlad960902010-03-29 19:23:52 +00004466 "-parallel dev redirect the parallel port to char device 'dev'\n",
4467 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004468SRST
4469``-parallel dev``
4470 Redirect the virtual parallel port to host device dev (same devices
4471 as the serial port). On Linux hosts, ``/dev/parportN`` can be used
4472 to use hardware devices connected on the corresponding host parallel
4473 port.
4474
4475 This option can be used several times to simulate up to 3 parallel
4476 ports.
4477
4478 Use ``-parallel none`` to disable all parallel ports.
4479ERST
blueswir15824d652009-03-28 06:44:27 +00004480
4481DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
Blue Swirlad960902010-03-29 19:23:52 +00004482 "-monitor dev redirect the monitor to char device 'dev'\n",
4483 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004484SRST
4485``-monitor dev``
4486 Redirect the monitor to host device dev (same devices as the serial
4487 port). The default device is ``vc`` in graphical mode and ``stdio``
4488 in non graphical mode. Use ``-monitor none`` to disable the default
4489 monitor.
4490ERST
Gerd Hoffmann6ca55822009-12-08 13:11:52 +01004491DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
Blue Swirlad960902010-03-29 19:23:52 +00004492 "-qmp dev like -monitor but opens in 'control' mode\n",
4493 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004494SRST
4495``-qmp dev``
Peter Maydell0ec44682023-05-15 17:22:45 +01004496 Like ``-monitor`` but opens in 'control' mode. For example, to make
4497 QMP available on localhost port 4444::
4498
4499 -qmp tcp:localhost:4444,server=on,wait=off
4500
4501 Not all options are configurable via this syntax; for maximum
4502 flexibility use the ``-mon`` option and an accompanying ``-chardev``.
4503
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004504ERST
Max Reitz4821cd42014-11-17 13:31:04 +01004505DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
4506 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
4507 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004508SRST
4509``-qmp-pretty dev``
Peter Maydell0ec44682023-05-15 17:22:45 +01004510 Like ``-qmp`` but uses pretty JSON formatting.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004511ERST
blueswir15824d652009-03-28 06:44:27 +00004512
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01004513DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
Vicente Jimenez Aguilaref670722017-11-14 09:11:27 +01004514 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004515SRST
4516``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]``
Peter Maydell0ec44682023-05-15 17:22:45 +01004517 Set up a monitor connected to the chardev ``name``.
4518 QEMU supports two monitors: the Human Monitor Protocol
4519 (HMP; for human interaction), and the QEMU Monitor Protocol
4520 (QMP; a JSON RPC-style protocol).
4521 The default is HMP; ``mode=control`` selects QMP instead.
4522 ``pretty`` is only valid when ``mode=control``,
Ali Shirvani16b3f3b2021-05-19 11:41:45 +04304523 turning on JSON pretty printing to ease
Daniel P. Berrangé283d8452021-02-19 17:56:13 +00004524 human reading and debugging.
Peter Maydell0ec44682023-05-15 17:22:45 +01004525
4526 For example::
4527
4528 -chardev socket,id=mon1,host=localhost,port=4444,server=on,wait=off \
4529 -mon chardev=mon1,mode=control,pretty=on
4530
4531 enables the QMP monitor on localhost port 4444 with pretty-printing.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004532ERST
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01004533
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08004534DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
Blue Swirlad960902010-03-29 19:23:52 +00004535 "-debugcon dev redirect the debug console to char device 'dev'\n",
4536 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004537SRST
4538``-debugcon dev``
4539 Redirect the debug console to host device dev (same devices as the
4540 serial port). The debug console is an I/O port which is typically
4541 port 0xe9; writing to that I/O port sends output to this device. The
4542 default device is ``vc`` in graphical mode and ``stdio`` in non
4543 graphical mode.
4544ERST
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08004545
blueswir15824d652009-03-28 06:44:27 +00004546DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
Blue Swirlad960902010-03-29 19:23:52 +00004547 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004548SRST
4549``-pidfile file``
4550 Store the QEMU process PID in file. It is useful if you launch QEMU
4551 from a script.
4552ERST
blueswir15824d652009-03-28 06:44:27 +00004553
Igor Mammedov047f7032018-05-11 19:24:43 +02004554DEF("preconfig", 0, QEMU_OPTION_preconfig, \
Markus Armbruster361ac942018-07-05 11:14:02 +02004555 "--preconfig pause QEMU before machine is initialized (experimental)\n",
Igor Mammedov047f7032018-05-11 19:24:43 +02004556 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004557SRST
4558``--preconfig``
4559 Pause QEMU for interactive configuration before the machine is
4560 created, which allows querying and configuring properties that will
4561 affect machine initialization. Use QMP command 'x-exit-preconfig' to
4562 exit the preconfig state and move to the next state (i.e. run guest
4563 if -S isn't used or pause the second time if -S is used). This
4564 option is experimental.
4565ERST
Igor Mammedov047f7032018-05-11 19:24:43 +02004566
blueswir15824d652009-03-28 06:44:27 +00004567DEF("S", 0, QEMU_OPTION_S, \
Blue Swirlad960902010-03-29 19:23:52 +00004568 "-S freeze CPU at startup (use 'c' to start execution)\n",
4569 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004570SRST
4571``-S``
4572 Do not start CPU at startup (you must type 'c' in the monitor).
4573ERST
blueswir15824d652009-03-28 06:44:27 +00004574
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004575DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02004576 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n"
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004577 " run qemu with overcommit hints\n"
4578 " mem-lock=on|off controls memory lock support (default: off)\n"
4579 " cpu-pm=on|off controls cpu power management (default: off)\n",
4580 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004581SRST
4582``-overcommit mem-lock=on|off``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004583 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004584``-overcommit cpu-pm=on|off``
4585 Run qemu with hints about host resource overcommit. The default is
4586 to assume that host overcommits all resources.
4587
4588 Locking qemu and guest memory can be enabled via ``mem-lock=on``
4589 (disabled by default). This works when host memory is not
Thomas Huthc8c9dc42020-12-10 16:58:07 +01004590 overcommitted and reduces the worst-case latency for guest.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004591
4592 Guest ability to manage power state of host cpus (increasing latency
4593 for other processes on the same host cpu, but decreasing latency for
4594 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This
4595 works best when host CPU is not overcommitted. When used, host
4596 estimates of CPU cycle and power utilization will be incorrect, not
4597 taking into account guest idle time.
4598ERST
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004599
aliguori59030a82009-04-05 18:43:41 +00004600DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
Peter Maydelle5910d42020-04-03 10:40:14 +01004601 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n"
4602 " the guest without waiting for gdb to connect; use -S too\n"
4603 " if you want it to not start execution.)\n",
4604 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004605SRST
4606``-gdb dev``
Thomas Huth923e9312020-11-16 15:47:36 +01004607 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter
4608 in the System Emulation Users Guide). Note that this option does not pause QEMU
Peter Maydelle5910d42020-04-03 10:40:14 +01004609 execution -- if you want QEMU to not start the guest until you
4610 connect with gdb and issue a ``continue`` command, you will need to
4611 also pass the ``-S`` option to QEMU.
4612
4613 The most usual configuration is to listen on a local TCP socket::
4614
4615 -gdb tcp::3117
4616
4617 but you can specify other backends; UDP, pseudo TTY, or even stdio
4618 are all reasonable use cases. For example, a stdio connection
4619 allows you to start QEMU from within gdb and establish the
4620 connection via a pipe:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004621
Peter Maydell09ce5f22020-02-28 15:36:13 +00004622 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004623
4624 (gdb) target remote | exec |qemu_system| -gdb stdio ...
4625ERST
blueswir15824d652009-03-28 06:44:27 +00004626
aliguori59030a82009-04-05 18:43:41 +00004627DEF("s", 0, QEMU_OPTION_s, \
Blue Swirlad960902010-03-29 19:23:52 +00004628 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
4629 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004630SRST
4631``-s``
4632 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
Thomas Huth923e9312020-11-16 15:47:36 +01004633 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004634ERST
blueswir15824d652009-03-28 06:44:27 +00004635
4636DEF("d", HAS_ARG, QEMU_OPTION_d, \
Peter Maydell989b6972013-02-26 17:52:40 +00004637 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
Blue Swirlad960902010-03-29 19:23:52 +00004638 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004639SRST
4640``-d item1[,...]``
4641 Enable logging of specified items. Use '-d help' for a list of log
4642 items.
4643ERST
blueswir15824d652009-03-28 06:44:27 +00004644
Matthew Fernandezc235d732011-06-07 16:32:40 +00004645DEF("D", HAS_ARG, QEMU_OPTION_D, \
Peter Maydell989b6972013-02-26 17:52:40 +00004646 "-D logfile output log to logfile (default stderr)\n",
Matthew Fernandezc235d732011-06-07 16:32:40 +00004647 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004648SRST
4649``-D logfile``
4650 Output log in logfile instead of to stderr
4651ERST
Matthew Fernandezc235d732011-06-07 16:32:40 +00004652
Alex Bennée35145522016-03-15 14:30:20 +00004653DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
4654 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
4655 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004656SRST
4657``-dfilter range1[,...]``
4658 Filter debug output to that relevant to a range of target addresses.
4659 The filter spec can be either start+size, start-size or start..end
4660 where start end and size are the addresses and sizes required. For
4661 example:
4662
4663 ::
4664
4665 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
4666
4667 Will dump output for any code in the 0x1000 sized block starting at
4668 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and
4669 another 0x1000 sized block starting at 0xffffffc00005f000.
4670ERST
Alex Bennée35145522016-03-15 14:30:20 +00004671
Richard Henderson9c09a252019-03-14 13:06:29 -07004672DEF("seed", HAS_ARG, QEMU_OPTION_seed, \
4673 "-seed number seed the pseudo-random number generator\n",
4674 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004675SRST
4676``-seed number``
4677 Force the guest to use a deterministic pseudo-random number
4678 generator, seeded with number. This does not affect crypto routines
4679 within the host.
4680ERST
Richard Henderson9c09a252019-03-14 13:06:29 -07004681
blueswir15824d652009-03-28 06:44:27 +00004682DEF("L", HAS_ARG, QEMU_OPTION_L, \
Blue Swirlad960902010-03-29 19:23:52 +00004683 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
4684 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004685SRST
4686``-L path``
4687 Set the directory for the BIOS, VGA BIOS and keymaps.
4688
4689 To list all the data directories, use ``-L help``.
4690ERST
blueswir15824d652009-03-28 06:44:27 +00004691
blueswir15824d652009-03-28 06:44:27 +00004692DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
Thomas Huth21abf012022-04-27 15:49:06 +02004693 "-enable-kvm enable KVM full virtualization support\n",
4694 QEMU_ARCH_ARM | QEMU_ARCH_I386 | QEMU_ARCH_MIPS | QEMU_ARCH_PPC |
4695 QEMU_ARCH_RISCV | QEMU_ARCH_S390X)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004696SRST
4697``-enable-kvm``
4698 Enable KVM full virtualization support. This option is only
4699 available if KVM support is enabled when compiling.
4700ERST
blueswir15824d652009-03-28 06:44:27 +00004701
aliguorie37630c2009-04-22 15:19:10 +00004702DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
Thomas Hutheeb36472022-04-27 15:31:56 +02004703 "-xen-domid id specify xen guest domain id\n",
4704 QEMU_ARCH_ARM | QEMU_ARCH_I386)
aliguorie37630c2009-04-22 15:19:10 +00004705DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
4706 "-xen-attach attach to existing xen domain\n"
Anthony PERARD1077bca2018-09-14 12:18:30 +01004707 " libxl will use this when starting QEMU\n",
Thomas Hutheeb36472022-04-27 15:31:56 +02004708 QEMU_ARCH_ARM | QEMU_ARCH_I386)
Paul Durrant1c599472017-03-22 09:39:15 +00004709DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
4710 "-xen-domid-restrict restrict set of available xen operations\n"
4711 " to specified domain id. (Does not affect\n"
4712 " xenpv machine type).\n",
Thomas Hutheeb36472022-04-27 15:31:56 +02004713 QEMU_ARCH_ARM | QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004714SRST
4715``-xen-domid id``
4716 Specify xen guest domain id (XEN only).
4717
4718``-xen-attach``
4719 Attach to existing xen domain. libxl will use this when starting
4720 QEMU (XEN only). Restrict set of available xen operations to
4721 specified domain id (XEN only).
4722ERST
aliguorie37630c2009-04-22 15:19:10 +00004723
blueswir15824d652009-03-28 06:44:27 +00004724DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
Blue Swirlad960902010-03-29 19:23:52 +00004725 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004726SRST
4727``-no-reboot``
4728 Exit instead of rebooting.
4729ERST
blueswir15824d652009-03-28 06:44:27 +00004730
4731DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
Blue Swirlad960902010-03-29 19:23:52 +00004732 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004733SRST
4734``-no-shutdown``
4735 Don't exit QEMU on guest shutdown, but instead only stop the
4736 emulation. This allows for instance switching to monitor to commit
4737 changes to the disk image.
4738ERST
blueswir15824d652009-03-28 06:44:27 +00004739
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004740DEF("action", HAS_ARG, QEMU_OPTION_action,
Paolo Bonzinic27025e2021-01-20 14:30:27 +01004741 "-action reboot=reset|shutdown\n"
4742 " action when guest reboots [default=reset]\n"
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004743 "-action shutdown=poweroff|pause\n"
4744 " action when guest shuts down [default=poweroff]\n"
Ilya Leoshkevich0882caf2022-07-26 00:37:45 +02004745 "-action panic=pause|shutdown|exit-failure|none\n"
Paolo Bonzinic27025e2021-01-20 14:30:27 +01004746 " action when guest panics [default=shutdown]\n"
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004747 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n"
4748 " action when watchdog fires [default=reset]\n",
4749 QEMU_ARCH_ALL)
4750SRST
4751``-action event=action``
4752 The action parameter serves to modify QEMU's default behavior when
4753 certain guest events occur. It provides a generic method for specifying the
4754 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown``
4755 parameters.
4756
4757 Examples:
4758
Alejandro Jimenezc753e8e2020-12-11 17:31:52 -05004759 ``-action panic=none``
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004760 ``-action reboot=shutdown,shutdown=pause``
Paolo Bonzini5433af72022-09-10 13:44:47 +02004761 ``-device i6300esb -action watchdog=pause``
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004762
4763ERST
4764
blueswir15824d652009-03-28 06:44:27 +00004765DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
4766 "-loadvm [tag|id]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004767 " start right away with a saved state (loadvm in monitor)\n",
4768 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004769SRST
4770``-loadvm file``
4771 Start right away with a saved state (``loadvm`` in monitor)
4772ERST
blueswir15824d652009-03-28 06:44:27 +00004773
4774#ifndef _WIN32
4775DEF("daemonize", 0, QEMU_OPTION_daemonize, \
Blue Swirlad960902010-03-29 19:23:52 +00004776 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004777#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004778SRST
4779``-daemonize``
4780 Daemonize the QEMU process after initialization. QEMU will not
4781 detach from standard IO until it is ready to receive connections on
4782 any of its devices. This option is a useful way for external
4783 programs to launch QEMU without having to cope with initialization
4784 race conditions.
4785ERST
blueswir15824d652009-03-28 06:44:27 +00004786
4787DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
Blue Swirlad960902010-03-29 19:23:52 +00004788 "-option-rom rom load a file, rom, into the option ROM space\n",
4789 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004790SRST
4791``-option-rom file``
4792 Load the contents of file as an option ROM. This option is useful to
4793 load things like EtherBoot.
4794ERST
blueswir15824d652009-03-28 06:44:27 +00004795
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02004796DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
Artem Pisarenko238d1242018-10-18 13:12:52 +06004797 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004798 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
4799 QEMU_ARCH_ALL)
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02004800
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004801SRST
4802``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]``
4803 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at
4804 the current UTC or local time, respectively. ``localtime`` is
4805 required for correct date in MS-DOS or Windows. To start at a
4806 specific point in time, provide datetime in the format
4807 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC.
4808
4809 By default the RTC is driven by the host system time. This allows
4810 using of the RTC as accurate reference clock inside the guest,
4811 specifically if the host time is smoothly following an accurate
4812 external reference clock, e.g. via NTP. If you want to isolate the
4813 guest time from the host, you can set ``clock`` to ``rt`` instead,
4814 which provides a host monotonic clock if host support it. To even
4815 prevent the RTC from progressing during suspension, you can set
4816 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is
4817 recommended especially in icount mode in order to preserve
4818 determinism; however, note that in icount mode the speed of the
4819 virtual clock is variable and can in general differ from the host
4820 clock.
4821
4822 Enable ``driftfix`` (i386 targets only) if you experience time drift
4823 problems, specifically with Windows' ACPI HAL. This option will try
4824 to figure out how many timer interrupts were not processed by the
4825 Windows guest and will re-inject them.
4826ERST
blueswir15824d652009-03-28 06:44:27 +00004827
4828DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
Peter Maydellfa647902020-11-21 21:35:06 +00004829 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \
aliguoribc14ca22009-04-05 18:43:37 +00004830 " enable virtual instruction counter with 2^N clock ticks per\n" \
Victor CLEMENTf1f4b572015-05-29 17:14:05 +02004831 " instruction, enable aligning the host and virtual clocks\n" \
Peter Maydellfa647902020-11-21 21:35:06 +00004832 " or disable real time cpu sleeping, and optionally enable\n" \
4833 " record-and-replay mode\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004834SRST
Peter Maydellfa647902020-11-21 21:35:06 +00004835``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004836 Enable virtual instruction counter. The virtual cpu will execute one
4837 instruction every 2^N ns of virtual time. If ``auto`` is specified
4838 then the virtual cpu speed will be automatically adjusted to keep
4839 virtual time within a few seconds of real time.
4840
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004841 Note that while this option can give deterministic behavior, it does
4842 not provide cycle accurate emulation. Modern CPUs contain
4843 superscalar out of order cores with complex cache hierarchies. The
4844 number of instructions executed often has little or no correlation
4845 with actual performance.
4846
Peter Maydellfa647902020-11-21 21:35:06 +00004847 When the virtual cpu is sleeping, the virtual time will advance at
4848 default speed unless ``sleep=on`` is specified. With
4849 ``sleep=on``, the virtual time will jump to the next timer
4850 deadline instantly whenever the virtual cpu goes to sleep mode and
4851 will not advance if no timer is enabled. This behavior gives
4852 deterministic execution times from the guest point of view.
4853 The default if icount is enabled is ``sleep=off``.
4854 ``sleep=on`` cannot be used together with either ``shift=auto``
4855 or ``align=on``.
4856
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004857 ``align=on`` will activate the delay algorithm which will try to
4858 synchronise the host clock and the virtual clock. The goal is to
4859 have a guest running at the real frequency imposed by the shift
4860 option. Whenever the guest clock is behind the host clock and if
4861 ``align=on`` is specified then we print a message to the user to
4862 inform about the delay. Currently this option does not work when
4863 ``shift`` is ``auto``. Note: The sync algorithm will work for those
4864 shift values for which the guest clock runs ahead of the host clock.
4865 Typically this happens when the shift value is high (how high
Peter Maydellfa647902020-11-21 21:35:06 +00004866 depends on the host machine). The default if icount is enabled
4867 is ``align=off``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004868
Peter Maydellfa647902020-11-21 21:35:06 +00004869 When the ``rr`` option is specified deterministic record/replay is
4870 enabled. The ``rrfile=`` option must also be provided to
4871 specify the path to the replay log. In record mode data is written
4872 to this file, and in replay mode it is read back.
4873 If the ``rrsnapshot`` option is given then it specifies a VM snapshot
4874 name. In record mode, a new VM snapshot with the given name is created
4875 at the start of execution recording. In replay mode this option
4876 specifies the snapshot name used to load the initial VM state.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004877ERST
blueswir15824d652009-03-28 06:44:27 +00004878
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004879DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
Markus Armbruster7ad92702017-10-02 16:03:07 +02004880 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004881 " action when watchdog fires [default=reset]\n",
4882 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004883SRST
4884``-watchdog-action action``
4885 The action controls what QEMU will do when the watchdog timer
4886 expires. The default is ``reset`` (forcefully reset the guest).
4887 Other possible actions are: ``shutdown`` (attempt to gracefully
4888 shutdown the guest), ``poweroff`` (forcefully poweroff the guest),
4889 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the
4890 guest), ``debug`` (print a debug message and continue), or ``none``
4891 (do nothing).
4892
4893 Note that the ``shutdown`` action requires that the guest responds
4894 to ACPI signals, which it may not be able to do in the sort of
4895 situations where the watchdog would have expired, and thus
4896 ``-watchdog-action shutdown`` is not recommended for production use.
4897
4898 Examples:
4899
Paolo Bonzini5433af72022-09-10 13:44:47 +02004900 ``-device i6300esb -watchdog-action pause``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004901
4902ERST
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004903
blueswir15824d652009-03-28 06:44:27 +00004904DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
Blue Swirlad960902010-03-29 19:23:52 +00004905 "-echr chr set terminal escape character instead of ctrl-a\n",
4906 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004907SRST
4908``-echr numeric_ascii_value``
4909 Change the escape character used for switching to the monitor when
4910 using monitor and serial sharing. The default is ``0x01`` when using
4911 the ``-nographic`` option. ``0x01`` is equal to pressing
4912 ``Control-a``. You can select a different character from the ascii
4913 control keys where 1 through 26 map to Control-a through Control-z.
4914 For instance you could use the either of the following to change the
4915 escape character to Control-t.
4916
4917 ``-echr 0x14``; \ ``-echr 20``
4918
4919ERST
blueswir15824d652009-03-28 06:44:27 +00004920
blueswir15824d652009-03-28 06:44:27 +00004921DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004922 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \
4923 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \
Michael Tokarev7c601802015-02-10 22:40:47 +03004924 "-incoming unix:socketpath\n" \
4925 " prepare for incoming migration, listen on\n" \
4926 " specified protocol and socket address\n" \
4927 "-incoming fd:fd\n" \
Steve Sistare385f5102023-09-08 07:22:11 -07004928 "-incoming file:filename[,offset=offset]\n" \
Michael Tokarev7c601802015-02-10 22:40:47 +03004929 "-incoming exec:cmdline\n" \
4930 " accept incoming migration on given file descriptor\n" \
Dr. David Alan Gilbert15970512015-05-29 19:52:52 +01004931 " or from given external command\n" \
4932 "-incoming defer\n" \
4933 " wait for the URI to be specified via migrate_incoming\n",
Blue Swirlad960902010-03-29 19:23:52 +00004934 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004935SRST
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004936``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004937 \
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004938``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004939 Prepare for incoming migration, listen on a given tcp port.
4940
4941``-incoming unix:socketpath``
4942 Prepare for incoming migration, listen on a given unix socket.
4943
4944``-incoming fd:fd``
Steve Sistare2a9e2e52023-09-08 07:22:10 -07004945 Accept incoming migration from a given file descriptor.
4946
Steve Sistare385f5102023-09-08 07:22:11 -07004947``-incoming file:filename[,offset=offset]``
4948 Accept incoming migration from a given file starting at offset.
4949 offset allows the common size suffixes, or a 0x prefix, but not both.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004950
4951``-incoming exec:cmdline``
4952 Accept incoming migration as an output from specified external
4953 command.
4954
4955``-incoming defer``
4956 Wait for the URI to be specified via migrate\_incoming. The monitor
4957 can be used to change settings (such as migration parameters) prior
4958 to issuing the migrate\_incoming to allow the migration to begin.
4959ERST
blueswir15824d652009-03-28 06:44:27 +00004960
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304961DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
4962 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004963SRST
4964``-only-migratable``
4965 Only allow migratable devices. Devices will not be allowed to enter
4966 an unmigratable state.
4967ERST
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304968
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004969DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
Blue Swirlad960902010-03-29 19:23:52 +00004970 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004971SRST
4972``-nodefaults``
4973 Don't create default devices. Normally, QEMU sets the default
4974 devices like serial port, parallel port, virtual console, monitor
4975 device, VGA adapter, floppy and CD-ROM drive and others. The
4976 ``-nodefaults`` option will disable all those default devices.
4977ERST
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004978
blueswir15824d652009-03-28 06:44:27 +00004979DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
4980 "-prom-env variable=value\n"
Blue Swirlad960902010-03-29 19:23:52 +00004981 " set OpenBIOS nvram variables\n",
4982 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004983SRST
4984``-prom-env variable=value``
4985 Set OpenBIOS nvram variable to given value (PPC, SPARC only).
4986
4987 ::
4988
4989 qemu-system-sparc -prom-env 'auto-boot?=false' \
4990 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
4991
4992 ::
4993
4994 qemu-system-ppc -prom-env 'auto-boot?=false' \
4995 -prom-env 'boot-device=hd:2,\yaboot' \
4996 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
4997ERST
blueswir15824d652009-03-28 06:44:27 +00004998DEF("semihosting", 0, QEMU_OPTION_semihosting,
Michael Wallef7bbcfb2014-04-22 20:18:42 +02004999 "-semihosting semihosting mode\n",
Markus Armbruster9d49bcf2021-05-03 10:40:33 +02005000 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA |
Philippe Mathieu-Daudé6c301482024-03-27 12:10:58 +01005001 QEMU_ARCH_MIPS | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005002SRST
5003``-semihosting``
Philippe Mathieu-Daudé6c301482024-03-27 12:10:58 +01005004 Enable :ref:`Semihosting` mode (ARM, M68K, Xtensa, MIPS, RISC-V only).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005005
Alex Bennée2da9d212023-01-24 18:01:13 +00005006 .. warning::
5007 Note that this allows guest direct access to the host filesystem, so
5008 should only be used with a trusted guest OS.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005009
5010 See the -semihosting-config option documentation for further
5011 information about the facilities this enables.
5012ERST
Liviu Ionescua38bb072014-12-11 12:07:48 +00005013DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
Peter Maydell52028612022-08-22 15:12:24 +01005014 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]\n" \
Leon Alraea59d31a2015-06-19 14:17:45 +01005015 " semihosting configuration\n",
Markus Armbruster9d49bcf2021-05-03 10:40:33 +02005016QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA |
Philippe Mathieu-Daudé6c301482024-03-27 12:10:58 +01005017QEMU_ARCH_MIPS | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005018SRST
Peter Maydell52028612022-08-22 15:12:24 +01005019``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]``
Philippe Mathieu-Daudé6c301482024-03-27 12:10:58 +01005020 Enable and configure :ref:`Semihosting` (ARM, M68K, Xtensa, MIPS, RISC-V
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005021 only).
5022
Alex Bennée2da9d212023-01-24 18:01:13 +00005023 .. warning::
5024 Note that this allows guest direct access to the host filesystem, so
5025 should only be used with a trusted guest OS.
Keith Packarda10b9d92021-01-08 22:42:52 +00005026
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005027 ``target=native|gdb|auto``
5028 Defines where the semihosting calls will be addressed, to QEMU
5029 (``native``) or to GDB (``gdb``). The default is ``auto``, which
5030 means ``gdb`` during debug sessions and ``native`` otherwise.
5031
5032 ``chardev=str1``
5033 Send the output to a chardev backend output for native or auto
5034 output when not in gdb
5035
Peter Maydell52028612022-08-22 15:12:24 +01005036 ``userspace=on|off``
5037 Allows code running in guest userspace to access the semihosting
5038 interface. The default is that only privileged guest code can
5039 make semihosting calls. Note that setting ``userspace=on`` should
5040 only be used if all guest code is trusted (for example, in
5041 bare-metal test case code).
5042
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005043 ``arg=str1,arg=str2,...``
5044 Allows the user to pass input arguments, and can be used
5045 multiple times to build up a list. The old-style
5046 ``-kernel``/``-append`` method of passing a command line is
5047 still supported for backward compatibility. If both the
5048 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are
5049 specified, the former is passed to semihosting as it always
5050 takes precedence.
5051ERST
blueswir15824d652009-03-28 06:44:27 +00005052DEF("old-param", 0, QEMU_OPTION_old_param,
Blue Swirlad960902010-03-29 19:23:52 +00005053 "-old-param old param mode\n", QEMU_ARCH_ARM)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005054SRST
5055``-old-param``
5056 Old param mode (ARM only).
5057ERST
Stefan Weil95d5f082010-01-20 22:25:27 +01005058
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03005059DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01005060 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01005061 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
Eduardo Otubo2b716fa2017-03-01 23:17:29 +01005062 " Enable seccomp mode 2 system call filter (default 'off').\n" \
5063 " use 'obsolete' to allow obsolete system calls that are provided\n" \
5064 " by the kernel, but typically no longer used by modern\n" \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01005065 " C library implementations.\n" \
Philippe Mathieu-Daudéd42304b2021-03-03 19:46:43 +01005066 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \
5067 " to elevate privileges using set*uid|gid system calls.\n" \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01005068 " The value 'children' will deny set*uid|gid system calls for\n" \
Eduardo Otubo995a2262017-03-13 22:16:01 +01005069 " main QEMU process but will allow forks and execves to run unprivileged\n" \
5070 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
Philippe Mathieu-Daudéd42304b2021-03-03 19:46:43 +01005071 " blocking *fork and execve\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01005072 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03005073 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005074SRST
5075``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]``
5076 Enable Seccomp mode 2 system call filter. 'on' will enable syscall
5077 filtering and 'off' will disable it. The default is 'off'.
5078
5079 ``obsolete=string``
5080 Enable Obsolete system calls
5081
5082 ``elevateprivileges=string``
5083 Disable set\*uid\|gid system calls
5084
5085 ``spawn=string``
5086 Disable \*fork and execve
5087
5088 ``resourcecontrol=string``
5089 Disable process affinity and schedular priority
5090ERST
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03005091
Gerd Hoffmann715a6642009-10-14 10:39:28 +02005092DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
Paolo Bonzinie960a7e2022-04-14 10:57:21 -04005093 "-readconfig <file>\n"
5094 " read config file\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005095SRST
5096``-readconfig file``
5097 Read device configuration from file. This approach is useful when
5098 you want to spawn QEMU process with many command line options but
5099 you don't want to exceed the command line character limit.
5100ERST
Thomas Huth2feac452018-08-21 12:59:56 +02005101
Eduardo Habkostf29a5612012-05-02 13:07:29 -03005102DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
5103 "-no-user-config\n"
Eduardo Habkost3478eae2017-10-04 00:00:25 -03005104 " do not load default user-provided config files at startup\n",
Eduardo Habkostf29a5612012-05-02 13:07:29 -03005105 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005106SRST
5107``-no-user-config``
5108 The ``-no-user-config`` option makes QEMU not load any of the
5109 user-provided config files on sysconfdir.
5110ERST
Thomas Huth2feac452018-08-21 12:59:56 +02005111
Prerna Saxenaab6540d2010-08-09 11:48:32 +01005112DEF("trace", HAS_ARG, QEMU_OPTION_trace,
Paolo Bonzini10578a22016-01-07 16:55:26 +03005113 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
Lluís23d15e82011-08-31 20:31:31 +02005114 " specify tracing options\n",
Prerna Saxenaab6540d2010-08-09 11:48:32 +01005115 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005116SRST
5117``-trace [[enable=]pattern][,events=file][,file=file]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00005118 .. include:: ../qemu-option-trace.rst.inc
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005119
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005120ERST
Lluís Vilanova42229a72017-07-24 17:28:22 +03005121DEF("plugin", HAS_ARG, QEMU_OPTION_plugin,
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02005122 "-plugin [file=]<file>[,<argname>=<argvalue>]\n"
Lluís Vilanova42229a72017-07-24 17:28:22 +03005123 " load a plugin\n",
5124 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005125SRST
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02005126``-plugin file=file[,argname=argvalue]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005127 Load a plugin.
5128
5129 ``file=file``
5130 Load the given plugin from a shared library file.
5131
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02005132 ``argname=argvalue``
5133 Argument passed to the plugin. (Can be given multiple times.)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005134ERST
Stefan Weil3dbf2c72010-01-16 18:19:44 +01005135
Markus Armbruster31e70d62013-02-13 19:49:37 +01005136HXCOMM Internal use
5137DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
5138DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
Anthony Liguoric7f0f3b2012-03-28 15:42:02 +02005139
Thomas Huth9ffcbe22023-07-03 09:44:47 +02005140#ifdef CONFIG_POSIX
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02005141DEF("run-with", HAS_ARG, QEMU_OPTION_run_with,
Thomas Huth95e0fb02024-05-06 13:20:58 +02005142 "-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]\n"
Thomas Huth9ffcbe22023-07-03 09:44:47 +02005143 " Set miscellaneous QEMU process lifecycle options:\n"
5144 " async-teardown=on enables asynchronous teardown (Linux only)\n"
Thomas Huth95e0fb02024-05-06 13:20:58 +02005145 " chroot=dir chroot to dir just before starting the VM\n"
5146 " user=username switch to the specified user before starting the VM\n"
5147 " user=uid:gid ditto, but use specified user-ID and group-ID instead\n",
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02005148 QEMU_ARCH_ALL)
5149SRST
Thomas Huth95e0fb02024-05-06 13:20:58 +02005150``-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]``
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02005151 Set QEMU process lifecycle options.
5152
5153 ``async-teardown=on`` enables asynchronous teardown. A new process called
5154 "cleanup/<QEMU_PID>" will be created at startup sharing the address
5155 space with the main QEMU process, using clone. It will wait for the
5156 main QEMU process to terminate completely, and then exit. This allows
5157 QEMU to terminate very quickly even if the guest was huge, leaving the
5158 teardown of the address space to the cleanup process. Since the cleanup
5159 process shares the same cgroups as the main QEMU process, accounting is
5160 performed correctly. This only works if the cleanup process is not
5161 forcefully killed with SIGKILL before the main QEMU process has
5162 terminated completely.
Thomas Huth9ffcbe22023-07-03 09:44:47 +02005163
5164 ``chroot=dir`` can be used for doing a chroot to the specified directory
5165 immediately before starting the guest execution. This is especially useful
Thomas Huth00cfbdc2025-01-03 16:54:11 +01005166 in combination with ``user=...``.
Thomas Huth95e0fb02024-05-06 13:20:58 +02005167
5168 ``user=username`` or ``user=uid:gid`` can be used to drop root privileges
Boqiao Fude12ebf2024-07-15 17:04:32 +08005169 before starting guest execution. QEMU will use the ``setuid`` and ``setgid``
5170 system calls to switch to the specified identity. Note that the
5171 ``user=username`` syntax will also apply the full set of supplementary
5172 groups for the user, whereas the ``user=uid:gid`` will use only the
5173 ``gid`` group.
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02005174ERST
5175#endif
Claudio Imbrendac891c242022-08-12 15:34:53 +02005176
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04005177DEF("msg", HAS_ARG, QEMU_OPTION_msg,
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005178 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n"
Markus Armbrusterdeda4972019-10-10 10:15:08 +02005179 " control error message format\n"
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005180 " timestamp=on enables timestamps (default: off)\n"
5181 " guest-name=on enables guest name prefix but only if\n"
5182 " -name guest option is set (default: off)\n",
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04005183 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005184SRST
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005185``-msg [timestamp[=on|off]][,guest-name[=on|off]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005186 Control error message format.
5187
5188 ``timestamp=on|off``
5189 Prefix messages with a timestamp. Default is off.
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005190
5191 ``guest-name=on|off``
5192 Prefix messages with guest name but only if -name guest option is set
5193 otherwise the option is ignored. Default is off.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005194ERST
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04005195
Amit Shahabfd9ce2014-06-20 18:56:08 +05305196DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
5197 "-dump-vmstate <file>\n"
5198 " Output vmstate information in JSON format to file.\n"
5199 " Use the scripts/vmstate-static-checker.py file to\n"
5200 " check for possible regressions in migration code\n"
Laurent Vivier23820532015-09-04 21:30:04 +02005201 " by comparing two such vmstate dumps.\n",
Amit Shahabfd9ce2014-06-20 18:56:08 +05305202 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005203SRST
5204``-dump-vmstate file``
5205 Dump json-encoded vmstate information for current machine type to
5206 file in file
5207ERST
Amit Shahabfd9ce2014-06-20 18:56:08 +05305208
Emilio G. Cota12df1892018-08-15 11:42:49 -04005209DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
5210 "-enable-sync-profile\n"
5211 " enable synchronization profiling\n",
5212 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005213SRST
5214``-enable-sync-profile``
5215 Enable synchronization profiling.
5216ERST
Emilio G. Cota12df1892018-08-15 11:42:49 -04005217
Ilya Leoshkevich5584e2d2023-01-12 16:20:13 +01005218#if defined(CONFIG_TCG) && defined(CONFIG_LINUX)
5219DEF("perfmap", 0, QEMU_OPTION_perfmap,
5220 "-perfmap generate a /tmp/perf-${pid}.map file for perf\n",
5221 QEMU_ARCH_ALL)
5222SRST
5223``-perfmap``
5224 Generate a map file for Linux perf tools that will allow basic profiling
5225 information to be broken down into basic blocks.
5226ERST
5227
5228DEF("jitdump", 0, QEMU_OPTION_jitdump,
5229 "-jitdump generate a jit-${pid}.dump file for perf\n",
5230 QEMU_ARCH_ALL)
5231SRST
5232``-jitdump``
5233 Generate a dump file for Linux perf tools that maps basic blocks to symbol
5234 names, line numbers and JITted code.
5235ERST
5236#endif
5237
Paolo Bonzini43f187a2017-01-04 13:50:37 +01005238DEFHEADING()
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02005239
5240DEFHEADING(Generic object creation:)
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01005241
5242DEF("object", HAS_ARG, QEMU_OPTION_object,
5243 "-object TYPENAME[,PROP1=VALUE1,...]\n"
5244 " create a new object of type TYPENAME setting properties\n"
5245 " in the order they are specified. Note that the 'id'\n"
5246 " property must be set. These objects are placed in the\n"
5247 " '/objects' path.\n",
5248 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005249SRST
5250``-object typename[,prop1=value1,...]``
5251 Create a new object of type typename setting properties in the order
5252 they are specified. Note that the 'id' property must be set. These
5253 objects are placed in the '/objects' path.
5254
David Hildenbrande92666b2023-09-06 14:04:55 +02005255 ``-object memory-backend-file,id=id,size=size,mem-path=dir,share=on|off,discard-data=on|off,merge=on|off,dump=on|off,prealloc=on|off,host-nodes=host-nodes,policy=default|preferred|bind|interleave,align=align,offset=offset,readonly=on|off,rom=on|off|auto``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005256 Creates a memory file backend object, which can be used to back
5257 the guest RAM with huge pages.
5258
5259 The ``id`` parameter is a unique ID that will be used to
Robert Hoo56c9f002021-04-22 16:42:02 +08005260 reference this memory region in other parameters, e.g. ``-numa``,
5261 ``-device nvdimm``, etc.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005262
5263 The ``size`` option provides the size of the memory region, and
Robert Hoo56c9f002021-04-22 16:42:02 +08005264 accepts common suffixes, e.g. ``500M``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005265
5266 The ``mem-path`` provides the path to either a shared memory or
5267 huge page filesystem mount.
5268
5269 The ``share`` boolean option determines whether the memory
5270 region is marked as private to QEMU, or shared. The latter
5271 allows a co-operating external process to access the QEMU memory
5272 region.
5273
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005274 Setting share=on might affect the ability to configure NUMA
5275 bindings for the memory backend under some circumstances, see
5276 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel
5277 source tree for additional details.
5278
5279 Setting the ``discard-data`` boolean option to on indicates that
5280 file contents can be destroyed when QEMU exits, to avoid
5281 unnecessarily flushing data to the backing file. Note that
5282 ``discard-data`` is only an optimization, and QEMU might not
5283 discard file contents if it aborts unexpectedly or is terminated
5284 using SIGKILL.
5285
5286 The ``merge`` boolean option enables memory merge, also known as
5287 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider
5288 the pages for memory deduplication.
5289
5290 Setting the ``dump`` boolean option to off excludes the memory
5291 from core dumps. This feature is also known as MADV\_DONTDUMP.
5292
5293 The ``prealloc`` boolean option enables memory preallocation.
5294
5295 The ``host-nodes`` option binds the memory range to a list of
5296 NUMA host nodes.
5297
5298 The ``policy`` option sets the NUMA policy to one of the
5299 following values:
5300
5301 ``default``
5302 default host policy
5303
5304 ``preferred``
5305 prefer the given host node list for allocation
5306
5307 ``bind``
5308 restrict memory allocation to the given host node list
5309
5310 ``interleave``
5311 interleave memory allocations across the given host node
5312 list
5313
5314 The ``align`` option specifies the base address alignment when
5315 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg
5316 ``2M``. Some backend store specified by ``mem-path`` requires an
5317 alignment different than the default one used by QEMU, eg the
5318 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
5319 such cases, users can specify the required alignment via this
5320 option.
5321
Alexander Graf4b870dc2023-04-03 22:14:21 +00005322 The ``offset`` option specifies the offset into the target file
5323 that the region starts at. You can use this parameter to back
5324 multiple regions with a single file.
5325
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005326 The ``pmem`` option specifies whether the backing file specified
5327 by ``mem-path`` is in host persistent memory that can be
5328 accessed using the SNIA NVM programming model (e.g. Intel
5329 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary
5330 operations to guarantee the persistence of its own writes to
5331 ``mem-path`` (e.g. in vNVDIMM label emulation and live
5332 migration). Also, we will map the backend-file with MAP\_SYNC
5333 flag, which ensures the file metadata is in sync for
5334 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC
5335 requires support from both the host kernel (since Linux kernel
5336 4.15) and the filesystem of ``mem-path`` mounted with DAX
5337 option.
5338
Stefan Hajnoczi86635aa2021-01-04 17:13:19 +00005339 The ``readonly`` option specifies whether the backing file is opened
5340 read-only or read-write (default).
5341
David Hildenbrande92666b2023-09-06 14:04:55 +02005342 The ``rom`` option specifies whether to create Read Only Memory
5343 (ROM) that cannot be modified by the VM. Any write attempts to such
5344 ROM will be denied. Most use cases want proper RAM instead of ROM.
5345 However, selected use cases, like R/O NVDIMMs, can benefit from
5346 ROM. If set to ``on``, create ROM; if set to ``off``, create
5347 writable RAM; if set to ``auto`` (default), the value of the
5348 ``readonly`` option is used. This option is primarily helpful when
5349 we want to have writable RAM in configurations that would
5350 traditionally create ROM before the ``rom`` option was introduced:
5351 VM templating, where we want to open a file readonly
5352 (``readonly=on``) and mark the memory to be private for QEMU
5353 (``share=off``). For this use case, we need writable RAM instead
5354 of ROM, and want to also set ``rom=off``.
5355
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005356 ``-object memory-backend-ram,id=id,merge=on|off,dump=on|off,share=on|off,prealloc=on|off,size=size,host-nodes=host-nodes,policy=default|preferred|bind|interleave``
5357 Creates a memory backend object, which can be used to back the
5358 guest RAM. Memory backend objects offer more control than the
5359 ``-m`` option that is traditionally used to define guest RAM.
5360 Please refer to ``memory-backend-file`` for a description of the
5361 options.
5362
5363 ``-object memory-backend-memfd,id=id,merge=on|off,dump=on|off,share=on|off,prealloc=on|off,size=size,host-nodes=host-nodes,policy=default|preferred|bind|interleave,seal=on|off,hugetlb=on|off,hugetlbsize=size``
5364 Creates an anonymous memory file backend object, which allows
5365 QEMU to share the memory with an external process (e.g. when
5366 using vhost-user). The memory is allocated with memfd and
5367 optional sealing. (Linux only)
5368
5369 The ``seal`` option creates a sealed-file, that will block
5370 further resizing the memory ('on' by default).
5371
5372 The ``hugetlb`` option specify the file to be created resides in
5373 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction
5374 with the ``hugetlb`` option, the ``hugetlbsize`` option specify
5375 the hugetlb page size on systems that support multiple hugetlb
5376 page sizes (it must be a power of 2 value supported by the
5377 system).
5378
5379 In some versions of Linux, the ``hugetlb`` option is
5380 incompatible with the ``seal`` option (requires at least Linux
5381 4.16).
5382
5383 Please refer to ``memory-backend-file`` for a description of the
5384 other options.
5385
5386 The ``share`` boolean option is on by default with memfd.
5387
Stefano Garzarella4e647fa2024-06-18 12:05:19 +02005388 ``-object memory-backend-shm,id=id,merge=on|off,dump=on|off,share=on|off,prealloc=on|off,size=size,host-nodes=host-nodes,policy=default|preferred|bind|interleave``
5389 Creates a POSIX shared memory backend object, which allows
5390 QEMU to share the memory with an external process (e.g. when
5391 using vhost-user).
5392
5393 ``memory-backend-shm`` is a more portable and less featureful version
5394 of ``memory-backend-memfd``. It can then be used in any POSIX system,
5395 especially when memfd is not supported.
5396
5397 Please refer to ``memory-backend-file`` for a description of the
5398 options.
5399
5400 The ``share`` boolean option is on by default with shm. Setting it to
5401 off will cause a failure during allocation because it is not supported
5402 by this backend.
5403
Eric Auger6e6d8ac2023-11-21 16:44:00 +08005404 ``-object iommufd,id=id[,fd=fd]``
5405 Creates an iommufd backend which allows control of DMA mapping
5406 through the ``/dev/iommu`` device.
5407
5408 The ``id`` parameter is a unique ID which frontends (such as
5409 vfio-pci of vdpa) will use to connect with the iommufd backend.
5410
5411 The ``fd`` parameter is an optional pre-opened file descriptor
5412 resulting from ``/dev/iommu`` opening. Usually the iommufd is shared
5413 across all subsystems, bringing the benefit of centralized
5414 reference counting.
5415
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005416 ``-object rng-builtin,id=id``
5417 Creates a random number generator backend which obtains entropy
5418 from QEMU builtin functions. The ``id`` parameter is a unique ID
5419 that will be used to reference this entropy backend from the
5420 ``virtio-rng`` device. By default, the ``virtio-rng`` device
5421 uses this RNG backend.
5422
5423 ``-object rng-random,id=id,filename=/dev/random``
5424 Creates a random number generator backend which obtains entropy
5425 from a device on the host. The ``id`` parameter is a unique ID
5426 that will be used to reference this entropy backend from the
5427 ``virtio-rng`` device. The ``filename`` parameter specifies
5428 which file to obtain entropy from and if omitted defaults to
5429 ``/dev/urandom``.
5430
5431 ``-object rng-egd,id=id,chardev=chardevid``
5432 Creates a random number generator backend which obtains entropy
5433 from an external daemon running on the host. The ``id``
5434 parameter is a unique ID that will be used to reference this
5435 entropy backend from the ``virtio-rng`` device. The ``chardev``
5436 parameter is the unique ID of a character device backend that
5437 provides the connection to the RNG daemon.
5438
5439 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off``
5440 Creates a TLS anonymous credentials object, which can be used to
5441 provide TLS support on network backends. The ``id`` parameter is
5442 a unique ID which network backends will use to access the
5443 credentials. The ``endpoint`` is either ``server`` or ``client``
5444 depending on whether the QEMU network backend that uses the
5445 credentials will be acting as a client or as a server. If
5446 ``verify-peer`` is enabled (the default) then once the handshake
5447 is completed, the peer credentials will be verified, though this
5448 is a no-op for anonymous credentials.
5449
5450 The dir parameter tells QEMU where to find the credential files.
5451 For server endpoints, this directory may contain a file
5452 dh-params.pem providing diffie-hellman parameters to use for the
5453 TLS server. If the file is missing, QEMU will generate a set of
5454 DH parameters at startup. This is a computationally expensive
5455 operation that consumes random pool entropy, so it is
5456 recommended that a persistent set of parameters be generated
5457 upfront and saved.
5458
5459 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]``
5460 Creates a TLS Pre-Shared Keys (PSK) credentials object, which
5461 can be used to provide TLS support on network backends. The
5462 ``id`` parameter is a unique ID which network backends will use
5463 to access the credentials. The ``endpoint`` is either ``server``
5464 or ``client`` depending on whether the QEMU network backend that
5465 uses the credentials will be acting as a client or as a server.
5466 For clients only, ``username`` is the username which will be
5467 sent to the server. If omitted it defaults to "qemu".
5468
5469 The dir parameter tells QEMU where to find the keys file. It is
5470 called "dir/keys.psk" and contains "username:key" pairs. This
5471 file can most easily be created using the GnuTLS ``psktool``
5472 program.
5473
5474 For server endpoints, dir may also contain a file dh-params.pem
5475 providing diffie-hellman parameters to use for the TLS server.
5476 If the file is missing, QEMU will generate a set of DH
5477 parameters at startup. This is a computationally expensive
5478 operation that consumes random pool entropy, so it is
5479 recommended that a persistent set of parameters be generated up
5480 front and saved.
5481
5482 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id``
5483 Creates a TLS anonymous credentials object, which can be used to
5484 provide TLS support on network backends. The ``id`` parameter is
5485 a unique ID which network backends will use to access the
5486 credentials. The ``endpoint`` is either ``server`` or ``client``
5487 depending on whether the QEMU network backend that uses the
5488 credentials will be acting as a client or as a server. If
5489 ``verify-peer`` is enabled (the default) then once the handshake
5490 is completed, the peer credentials will be verified. With x509
5491 certificates, this implies that the clients must be provided
5492 with valid client certificates too.
5493
5494 The dir parameter tells QEMU where to find the credential files.
5495 For server endpoints, this directory may contain a file
5496 dh-params.pem providing diffie-hellman parameters to use for the
5497 TLS server. If the file is missing, QEMU will generate a set of
5498 DH parameters at startup. This is a computationally expensive
5499 operation that consumes random pool entropy, so it is
5500 recommended that a persistent set of parameters be generated
5501 upfront and saved.
5502
5503 For x509 certificate credentials the directory will contain
5504 further files providing the x509 certificates. The certificates
5505 must be stored in PEM format, in filenames ca-cert.pem,
5506 ca-crl.pem (optional), server-cert.pem (only servers),
5507 server-key.pem (only servers), client-cert.pem (only clients),
5508 and client-key.pem (only clients).
5509
5510 For the server-key.pem and client-key.pem files which contain
5511 sensitive private keys, it is possible to use an encrypted
5512 version by providing the passwordid parameter. This provides the
5513 ID of a previously created ``secret`` object containing the
5514 password for decryption.
5515
5516 The priority parameter allows to override the global default
5517 priority used by gnutls. This can be useful if the system
5518 administrator needs to use a weaker set of crypto priorities for
5519 QEMU without potentially forcing the weakness onto all
5520 applications. Or conversely if one wants wants a stronger
5521 default for QEMU than for all other applications, they can do
5522 this through this parameter. Its format is a gnutls priority
5523 string as described at
5524 https://gnutls.org/manual/html_node/Priority-Strings.html.
5525
Philippe Mathieu-Daudé993aec22018-10-11 20:21:11 +02005526 ``-object tls-cipher-suites,id=id,priority=priority``
5527 Creates a TLS cipher suites object, which can be used to control
5528 the TLS cipher/protocol algorithms that applications are permitted
5529 to use.
5530
5531 The ``id`` parameter is a unique ID which frontends will use to
5532 access the ordered list of permitted TLS cipher suites from the
5533 host.
5534
5535 The ``priority`` parameter allows to override the global default
5536 priority used by gnutls. This can be useful if the system
5537 administrator needs to use a weaker set of crypto priorities for
5538 QEMU without potentially forcing the weakness onto all
5539 applications. Or conversely if one wants wants a stronger
5540 default for QEMU than for all other applications, they can do
5541 this through this parameter. Its format is a gnutls priority
5542 string as described at
5543 https://gnutls.org/manual/html_node/Priority-Strings.html.
5544
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02005545 An example of use of this object is to control UEFI HTTPS Boot.
5546 The tls-cipher-suites object exposes the ordered list of permitted
5547 TLS cipher suites from the host side to the guest firmware, via
5548 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER
5549 objects. The firmware uses the IANA_TLS_CIPHER array for configuring
5550 guest-side TLS.
5551
5552 In the following example, the priority at which the host-side policy
5553 is retrieved is given by the ``priority`` property.
5554 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to
5555 refer to /etc/crypto-policies/back-ends/gnutls.config.
5556
5557 .. parsed-literal::
5558
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005559 # |qemu_system| \\
5560 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02005561 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0
5562
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005563 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]``
5564 Interval t can't be 0, this filter batches the packet delivery:
5565 all packets arriving in a given interval on netdev netdevid are
5566 delayed until the end of the interval. Interval is in
5567 microseconds. ``status`` is optional that indicate whether the
5568 netfilter is on (enabled) or off (disabled), the default status
5569 for netfilter will be 'on'.
5570
5571 queue all\|rx\|tx is an option that can be applied to any
5572 netfilter.
5573
5574 ``all``: the filter is attached both to the receive and the
5575 transmit queue of the netdev (default).
5576
5577 ``rx``: the filter is attached to the receive queue of the
5578 netdev, where it will receive packets sent to the netdev.
5579
5580 ``tx``: the filter is attached to the transmit queue of the
5581 netdev, where it will receive packets sent by the netdev.
5582
5583 position head\|tail\|id=<id> is an option to specify where the
5584 filter should be inserted in the filter list. It can be applied
5585 to any netfilter.
5586
5587 ``head``: the filter is inserted at the head of the filter list,
5588 before any existing filters.
5589
5590 ``tail``: the filter is inserted at the tail of the filter list,
5591 behind any existing filters (default).
5592
5593 ``id=<id>``: the filter is inserted before or behind the filter
5594 specified by <id>, see the insert option below.
5595
5596 insert behind\|before is an option to specify where to insert
5597 the new filter relative to the one specified with
5598 position=id=<id>. It can be applied to any netfilter.
5599
5600 ``before``: insert before the specified filter.
5601
5602 ``behind``: insert behind the specified filter (default).
5603
5604 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5605 filter-mirror on netdev netdevid,mirror net packet to
5606 chardevchardevid, if it has the vnet\_hdr\_support flag,
5607 filter-mirror will mirror packet with vnet\_hdr\_len.
5608
5609 ``-object filter-redirector,id=id,netdev=netdevid,indev=chardevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5610 filter-redirector on netdev netdevid,redirect filter's net
5611 packet to chardev chardevid,and redirect indev's packet to
5612 filter.if it has the vnet\_hdr\_support flag, filter-redirector
5613 will redirect packet with vnet\_hdr\_len. Create a
5614 filter-redirector we need to differ outdev id from indev id, id
5615 can not be the same. we can just use indev or outdev, but at
5616 least one of indev or outdev need to be specified.
5617
5618 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5619 Filter-rewriter is a part of COLO project.It will rewrite tcp
5620 packet to secondary from primary to keep secondary tcp
5621 connection,and rewrite tcp packet to primary from secondary make
5622 tcp packet can be handled by client.if it has the
5623 vnet\_hdr\_support flag, we can parse packet with vnet header.
5624
5625 usage: colo secondary: -object
5626 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object
5627 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object
5628 filter-rewriter,id=rew0,netdev=hn0,queue=all
5629
5630 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]``
5631 Dump the network traffic on netdev dev to the file specified by
5632 filename. At most len bytes (64k by default) per packet are
5633 stored. The file format is libpcap, so it can be analyzed with
5634 tools such as tcpdump or Wireshark.
5635
Zhang Chena2e5cb72020-06-24 09:20:41 +08005636 ``-object colo-compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=chardevid,iothread=id[,vnet_hdr_support][,notify_dev=id][,compare_timeout=@var{ms}][,expired_scan_cycle=@var{ms}][,max_queue_size=@var{size}]``
Zhang Chen2b28a7e2020-06-24 09:20:42 +08005637 Colo-compare gets packet from primary\_in chardevid and
5638 secondary\_in, then compare whether the payload of primary packet
5639 and secondary packet are the same. If same, it will output
5640 primary packet to out\_dev, else it will notify COLO-framework to do
5641 checkpoint and send primary packet to out\_dev. In order to
5642 improve efficiency, we need to put the task of comparison in
5643 another iothread. If it has the vnet\_hdr\_support flag,
5644 colo compare will send/recv packet with vnet\_hdr\_len.
5645 The compare\_timeout=@var{ms} determines the maximum time of the
5646 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms}
5647 is to set the period of scanning expired primary node network packets.
5648 The max\_queue\_size=@var{size} is to set the max compare queue
5649 size depend on user environment.
5650 If user want to use Xen COLO, need to add the notify\_dev to
Zhang Chen9cc43c92020-03-18 16:23:19 +08005651 notify Xen colo-frame to do checkpoint.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005652
Zhang Chen2b28a7e2020-06-24 09:20:42 +08005653 COLO-compare must be used with the help of filter-mirror,
5654 filter-redirector and filter-rewriter.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005655
5656 ::
5657
5658 KVM COLO
5659
5660 primary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005661 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005662 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005663 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off
5664 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off
5665 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005666 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005667 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005668 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
5669 -object iothread,id=iothread1
5670 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
5671 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
5672 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
5673 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1
5674
5675 secondary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005676 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005677 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
5678 -chardev socket,id=red0,host=3.3.3.3,port=9003
5679 -chardev socket,id=red1,host=3.3.3.3,port=9004
5680 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
5681 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
5682
5683
5684 Xen COLO
5685
5686 primary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005687 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005688 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005689 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off
5690 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off
5691 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005692 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005693 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005694 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005695 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005696 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
5697 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
5698 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
5699 -object iothread,id=iothread1
Manos Pitsidianakis835f3642024-02-20 10:52:23 +02005700 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=notify_way,iothread=iothread1
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005701
5702 secondary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005703 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005704 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
5705 -chardev socket,id=red0,host=3.3.3.3,port=9003
5706 -chardev socket,id=red1,host=3.3.3.3,port=9004
5707 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
5708 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
5709
5710 If you want to know the detail of above command line, you can
5711 read the colo-compare git log.
5712
5713 ``-object cryptodev-backend-builtin,id=id[,queues=queues]``
Stefan Weil1e458f12022-10-30 11:59:44 +01005714 Creates a cryptodev backend which executes crypto operations from
5715 the QEMU cipher APIs. The id parameter is a unique ID that will
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005716 be used to reference this cryptodev backend from the
5717 ``virtio-crypto`` device. The queues parameter is optional,
5718 which specify the queue number of cryptodev backend, the default
5719 of queues is 1.
5720
Peter Maydell09ce5f22020-02-28 15:36:13 +00005721 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005722
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005723 # |qemu_system| \\
5724 [...] \\
5725 -object cryptodev-backend-builtin,id=cryptodev0 \\
5726 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005727 [...]
5728
5729 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]``
5730 Creates a vhost-user cryptodev backend, backed by a chardev
5731 chardevid. The id parameter is a unique ID that will be used to
5732 reference this cryptodev backend from the ``virtio-crypto``
5733 device. The chardev should be a unix domain socket backed one.
5734 The vhost-user uses a specifically defined protocol to pass
5735 vhost ioctl replacement messages to an application on the other
5736 end of the socket. The queues parameter is optional, which
5737 specify the queue number of cryptodev backend for multiqueue
5738 vhost-user, the default of queues is 1.
5739
Peter Maydell09ce5f22020-02-28 15:36:13 +00005740 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005741
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005742 # |qemu_system| \\
5743 [...] \\
5744 -chardev socket,id=chardev0,path=/path/to/socket \\
5745 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\
5746 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005747 [...]
5748
5749 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00005750 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005751 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]``
5752 Defines a secret to store a password, encryption key, or some
5753 other sensitive data. The sensitive data can either be passed
5754 directly via the data parameter, or indirectly via the file
5755 parameter. Using the data parameter is insecure unless the
5756 sensitive data is encrypted.
5757
5758 The sensitive data can be provided in raw format (the default),
5759 or base64. When encoded as JSON, the raw format only supports
5760 valid UTF-8 characters, so base64 is recommended for sending
5761 binary data. QEMU will convert from which ever format is
5762 provided to the format it needs internally. eg, an RBD password
5763 can be provided in raw format, even though it will be base64
5764 encoded when passed onto the RBD sever.
5765
5766 For added protection, it is possible to encrypt the data
5767 associated with a secret using the AES-256-CBC cipher. Use of
5768 encryption is indicated by providing the keyid and iv
5769 parameters. The keyid parameter provides the ID of a previously
5770 defined secret that contains the AES-256 decryption key. This
5771 key should be 32-bytes long and be base64 encoded. The iv
5772 parameter provides the random initialization vector used for
5773 encryption of this particular secret and should be a base64
5774 encrypted string of the 16-byte IV.
5775
5776 The simplest (insecure) usage is to provide the secret inline
5777
Peter Maydell09ce5f22020-02-28 15:36:13 +00005778 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005779
5780 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw
5781
5782 The simplest secure usage is to provide the secret via a file
5783
5784 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object
5785 secret,id=sec0,file=mypasswd.txt,format=raw
5786
5787 For greater security, AES-256-CBC should be used. To illustrate
5788 usage, consider the openssl command line tool which can encrypt
5789 the data. Note that when encrypting, the plaintext must be
5790 padded to the cipher block size (32 bytes) using the standard
5791 PKCS#5/6 compatible padding algorithm.
5792
5793 First a master key needs to be created in base64 encoding:
5794
5795 ::
5796
5797 # openssl rand -base64 32 > key.b64
5798 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
5799
5800 Each secret to be encrypted needs to have a random
5801 initialization vector generated. These do not need to be kept
5802 secret
5803
5804 ::
5805
5806 # openssl rand -base64 16 > iv.b64
5807 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
5808
5809 The secret to be defined can now be encrypted, in this case
5810 we're telling openssl to base64 encode the result, but it could
5811 be left as raw bytes if desired.
5812
5813 ::
5814
5815 # SECRET=$(printf "letmein" |
5816 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
5817
5818 When launching QEMU, create a master secret pointing to
5819 ``key.b64`` and specify that to be used to decrypt the user
5820 password. Pass the contents of ``iv.b64`` to the second secret
5821
Peter Maydell09ce5f22020-02-28 15:36:13 +00005822 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005823
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005824 # |qemu_system| \\
5825 -object secret,id=secmaster0,format=base64,file=key.b64 \\
5826 -object secret,id=sec0,keyid=secmaster0,format=base64,\\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005827 data=$SECRET,iv=$(<iv.b64)
5828
Dov Murik55cdf562021-11-11 10:00:43 +00005829 ``-object sev-guest,id=id,cbitpos=cbitpos,reduced-phys-bits=val,[sev-device=string,policy=policy,handle=handle,dh-cert-file=file,session-file=file,kernel-hashes=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005830 Create a Secure Encrypted Virtualization (SEV) guest object,
5831 which can be used to provide the guest memory encryption support
5832 on AMD processors.
5833
5834 When memory encryption is enabled, one of the physical address
5835 bit (aka the C-bit) is utilized to mark if a memory page is
5836 protected. The ``cbitpos`` is used to provide the C-bit
5837 position. The C-bit position is Host family dependent hence user
5838 must provide this value. On EPYC, the value should be 47.
5839
5840 When memory encryption is enabled, we loose certain bits in
5841 physical address space. The ``reduced-phys-bits`` is used to
5842 provide the number of bits we loose in physical address space.
5843 Similar to C-bit, the value is Host family dependent. On EPYC,
Tom Lendacky326e3012022-09-30 10:14:28 -05005844 a guest will lose a maximum of 1 bit, so the value should be 1.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005845
5846 The ``sev-device`` provides the device file to use for
5847 communicating with the SEV firmware running inside AMD Secure
5848 Processor. The default device is '/dev/sev'. If hardware
5849 supports memory encryption then /dev/sev devices are created by
5850 CCP driver.
5851
5852 The ``policy`` provides the guest policy to be enforced by the
5853 SEV firmware and restrict what configuration and operational
5854 commands can be performed on this guest by the hypervisor. The
5855 policy should be provided by the guest owner and is bound to the
5856 guest and cannot be changed throughout the lifetime of the
5857 guest. The default is 0.
5858
5859 If guest ``policy`` allows sharing the key with another SEV
5860 guest then ``handle`` can be use to provide handle of the guest
5861 from which to share the key.
5862
5863 The ``dh-cert-file`` and ``session-file`` provides the guest
5864 owner's Public Diffie-Hillman key defined in SEV spec. The PDH
5865 and session parameters are used for establishing a cryptographic
5866 session with the guest owner to negotiate keys used for
5867 attestation. The file must be encoded in base64.
5868
Dov Murik55cdf562021-11-11 10:00:43 +00005869 The ``kernel-hashes`` adds the hashes of given kernel/initrd/
5870 cmdline to a designated guest firmware page for measured Linux
5871 boot with -kernel. The default is off. (Since 6.2)
5872
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005873 e.g to launch a SEV guest
5874
Peter Maydell09ce5f22020-02-28 15:36:13 +00005875 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005876
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005877 # |qemu_system_x86| \\
5878 ...... \\
Tom Lendacky326e3012022-09-30 10:14:28 -05005879 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \\
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005880 -machine ...,memory-encryption=sev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005881 .....
5882
5883 ``-object authz-simple,id=id,identity=string``
5884 Create an authorization object that will control access to
5885 network services.
5886
5887 The ``identity`` parameter is identifies the user and its format
5888 depends on the network service that authorization object is
5889 associated with. For authorizing based on TLS x509 certificates,
5890 the identity must be the x509 distinguished name. Note that care
5891 must be taken to escape any commas in the distinguished name.
5892
5893 An example authorization object to validate a x509 distinguished
5894 name would look like:
5895
Peter Maydell09ce5f22020-02-28 15:36:13 +00005896 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005897
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005898 # |qemu_system| \\
5899 ... \\
5900 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005901 ...
5902
5903 Note the use of quotes due to the x509 distinguished name
5904 containing whitespace, and escaping of ','.
5905
Daniel P. Berrangé4d7beea2020-11-04 13:57:21 +00005906 ``-object authz-listfile,id=id,filename=path,refresh=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005907 Create an authorization object that will control access to
5908 network services.
5909
5910 The ``filename`` parameter is the fully qualified path to a file
5911 containing the access control list rules in JSON format.
5912
5913 An example set of rules that match against SASL usernames might
5914 look like:
5915
5916 ::
5917
5918 {
5919 "rules": [
5920 { "match": "fred", "policy": "allow", "format": "exact" },
5921 { "match": "bob", "policy": "allow", "format": "exact" },
5922 { "match": "danb", "policy": "deny", "format": "glob" },
5923 { "match": "dan*", "policy": "allow", "format": "exact" },
5924 ],
5925 "policy": "deny"
5926 }
5927
5928 When checking access the object will iterate over all the rules
5929 and the first rule to match will have its ``policy`` value
5930 returned as the result. If no rules match, then the default
5931 ``policy`` value is returned.
5932
5933 The rules can either be an exact string match, or they can use
5934 the simple UNIX glob pattern matching to allow wildcards to be
5935 used.
5936
5937 If ``refresh`` is set to true the file will be monitored and
5938 automatically reloaded whenever its content changes.
5939
5940 As with the ``authz-simple`` object, the format of the identity
5941 strings being matched depends on the network service, but is
5942 usually a TLS x509 distinguished name, or a SASL username.
5943
5944 An example authorization object to validate a SASL username
5945 would look like:
5946
Peter Maydell09ce5f22020-02-28 15:36:13 +00005947 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005948
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005949 # |qemu_system| \\
5950 ... \\
Daniel P. Berrangé4d7beea2020-11-04 13:57:21 +00005951 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005952 ...
5953
5954 ``-object authz-pam,id=id,service=string``
5955 Create an authorization object that will control access to
5956 network services.
5957
5958 The ``service`` parameter provides the name of a PAM service to
5959 use for authorization. It requires that a file
5960 ``/etc/pam.d/service`` exist to provide the configuration for
5961 the ``account`` subsystem.
5962
5963 An example authorization object to validate a TLS x509
5964 distinguished name would look like:
5965
Peter Maydell09ce5f22020-02-28 15:36:13 +00005966 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005967
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005968 # |qemu_system| \\
5969 ... \\
5970 -object authz-pam,id=auth0,service=qemu-vnc \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005971 ...
5972
5973 There would then be a corresponding config file for PAM at
5974 ``/etc/pam.d/qemu-vnc`` that contains:
5975
5976 ::
5977
5978 account requisite pam_listfile.so item=user sense=allow \
5979 file=/etc/qemu/vnc.allow
5980
5981 Finally the ``/etc/qemu/vnc.allow`` file would contain the list
Stefan Weil1e458f12022-10-30 11:59:44 +01005982 of x509 distinguished names that are permitted access
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005983
5984 ::
5985
5986 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB
5987
Stefano Garzarella1793ad02021-07-21 11:42:10 +02005988 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005989 Creates a dedicated event loop thread that devices can be
5990 assigned to. This is known as an IOThread. By default device
5991 emulation happens in vCPU threads or the main event loop thread.
5992 This can become a scalability bottleneck. IOThreads allow device
5993 emulation and I/O to run on other host CPUs.
5994
5995 The ``id`` parameter is a unique ID that will be used to
5996 reference this IOThread from ``-device ...,iothread=id``.
5997 Multiple devices can be assigned to an IOThread. Note that not
5998 all devices support an ``iothread`` parameter.
5999
6000 The ``query-iothreads`` QMP command lists IOThreads and reports
6001 their thread IDs so that the user can configure host CPU
6002 pinning/affinity.
6003
6004 IOThreads use an adaptive polling algorithm to reduce event loop
6005 latency. Instead of entering a blocking system call to monitor
6006 file descriptors and then pay the cost of being woken up when an
6007 event occurs, the polling algorithm spins waiting for events for
6008 a short time. The algorithm's default parameters are suitable
6009 for many cases but can be adjusted based on knowledge of the
6010 workload and/or host device latency.
6011
6012 The ``poll-max-ns`` parameter is the maximum number of
6013 nanoseconds to busy wait for events. Polling can be disabled by
6014 setting this value to 0.
6015
6016 The ``poll-grow`` parameter is the multiplier used to increase
6017 the polling time when the algorithm detects it is missing events
6018 due to not polling long enough.
6019
6020 The ``poll-shrink`` parameter is the divisor used to decrease
6021 the polling time when the algorithm detects it is spending too
6022 long polling without encountering events.
6023
Stefano Garzarella1793ad02021-07-21 11:42:10 +02006024 The ``aio-max-batch`` parameter is the maximum number of requests
6025 in a batch for the AIO engine, 0 means that the engine will use
6026 its default.
6027
6028 The IOThread parameters can be modified at run-time using the
Peter Maydelle2fcbf42020-03-06 10:07:14 +00006029 ``qom-set`` command (where ``iothread1`` is the IOThread's
6030 ``id``):
6031
6032 ::
6033
6034 (qemu) qom-set /objects/iothread1 poll-max-ns 100000
6035ERST
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01006036
6037
Stefan Weil3dbf2c72010-01-16 18:19:44 +01006038HXCOMM This is the last statement. Insert new options before this line!
Paolo Bonzinifd5fc4b2021-05-17 07:34:21 -04006039
6040#undef DEF
6041#undef DEFHEADING
6042#undef ARCHHEADING