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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,
1105 it is strongly recommended that you use the "reconnect=" chardev
1106 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("portrait", 0, QEMU_OPTION_portrait,
Blue Swirlad960902010-03-29 19:23:52 +00002335 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
2336 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002337SRST
2338``-portrait``
2339 Rotate graphical output 90 deg left (only PXA LCD).
2340ERST
blueswir15824d652009-03-28 06:44:27 +00002341
Vasily Khoruzhick93128052011-06-17 13:04:36 +03002342DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
2343 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
2344 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002345SRST
2346``-rotate deg``
2347 Rotate graphical output some deg left (only PXA LCD).
2348ERST
Vasily Khoruzhick93128052011-06-17 13:04:36 +03002349
blueswir15824d652009-03-28 06:44:27 +00002350DEF("vga", HAS_ARG, QEMU_OPTION_vga,
Gerd Hoffmanna94f0c52014-09-10 14:28:48 +02002351 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
Blue Swirlad960902010-03-29 19:23:52 +00002352 " select video card type\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002353SRST
2354``-vga type``
2355 Select type of VGA card to emulate. Valid values for type are
2356
2357 ``cirrus``
2358 Cirrus Logic GD5446 Video card. All Windows versions starting
2359 from Windows 95 should recognize and use this graphic card. For
2360 optimal performances, use 16 bit color depth in the guest and
2361 the host OS. (This card was the default before QEMU 2.2)
2362
2363 ``std``
2364 Standard VGA card with Bochs VBE extensions. If your guest OS
2365 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if
2366 you want to use high resolution modes (>= 1280x1024x16) then you
2367 should use this option. (This card is the default since QEMU
2368 2.2)
2369
2370 ``vmware``
2371 VMWare SVGA-II compatible adapter. Use it if you have
2372 sufficiently recent XFree86/XOrg server or Windows guest with a
2373 driver for this card.
2374
2375 ``qxl``
2376 QXL paravirtual graphic card. It is VGA compatible (including
2377 VESA 2.0 VBE support). Works best with qxl guest drivers
2378 installed though. Recommended choice when using the spice
2379 protocol.
2380
2381 ``tcx``
2382 (sun4m only) Sun TCX framebuffer. This is the default
2383 framebuffer for sun4m machines and offers both 8-bit and 24-bit
2384 colour depths at a fixed resolution of 1024x768.
2385
2386 ``cg3``
2387 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit
2388 framebuffer for sun4m machines available in both 1024x768
2389 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people
2390 wishing to run older Solaris versions.
2391
2392 ``virtio``
2393 Virtio VGA card.
2394
2395 ``none``
2396 Disable VGA card.
2397ERST
blueswir15824d652009-03-28 06:44:27 +00002398
2399DEF("full-screen", 0, QEMU_OPTION_full_screen,
Blue Swirlad960902010-03-29 19:23:52 +00002400 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002401SRST
2402``-full-screen``
2403 Start in full screen.
2404ERST
blueswir15824d652009-03-28 06:44:27 +00002405
John Snow60f9a4e2020-02-04 11:56:38 -05002406DEF("g", HAS_ARG, QEMU_OPTION_g ,
Blue Swirlad960902010-03-29 19:23:52 +00002407 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
Laurent Vivier8ac919a2019-10-26 18:45:43 +02002408 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002409SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00002410``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002411 Set the initial graphical resolution and depth (PPC, SPARC only).
2412
2413 For PPC the default is 800x600x32.
2414
2415 For SPARC with the TCX graphics device, the default is 1024x768x8
2416 with the option of 1024x768x24. For cgthree, the default is
2417 1024x768x8 with the option of 1152x900x8 for people who wish to use
2418 OBP.
2419ERST
blueswir15824d652009-03-28 06:44:27 +00002420
Marc-André Lureau62611642023-10-25 17:05:08 +04002421#ifdef CONFIG_VNC
blueswir15824d652009-03-28 06:44:27 +00002422DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
Robert Hof04ec5a2016-07-26 18:17:11 +08002423 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
Marc-André Lureau62611642023-10-25 17:05:08 +04002424#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002425SRST
2426``-vnc display[,option[,option[,...]]]``
2427 Normally, if QEMU is compiled with graphical window support, it
2428 displays output such as guest graphics, guest console, and the QEMU
2429 monitor in a window. With this option, you can have QEMU listen on
2430 VNC display display and redirect the VGA display over the VNC
2431 session. It is very useful to enable the usb tablet device when
2432 using this option (option ``-device usb-tablet``). When using the
2433 VNC display, you must use the ``-k`` parameter to set the keyboard
2434 layout if you are not using en-us. Valid syntax for the display is
2435
2436 ``to=L``
2437 With this option, QEMU will try next available VNC displays,
Manos Pitsidianakis835f3642024-02-20 10:52:23 +02002438 until the number L, if the originally defined "-vnc display" is
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002439 not available, e.g. port 5900+display is already used by another
2440 application. By default, to=0.
2441
2442 ``host:d``
2443 TCP connections will only be allowed from host on display d. By
2444 convention the TCP port is 5900+d. Optionally, host can be
2445 omitted in which case the server will accept connections from
2446 any host.
2447
2448 ``unix:path``
2449 Connections will be allowed over UNIX domain sockets where path
2450 is the location of a unix socket to listen for connections on.
2451
2452 ``none``
2453 VNC is initialized but not started. The monitor ``change``
2454 command can be used to later start the VNC server.
2455
2456 Following the display value there may be one or more option flags
2457 separated by commas. Valid options are
2458
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002459 ``reverse=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002460 Connect to a listening VNC client via a "reverse" connection.
2461 The client is specified by the display. For reverse network
2462 connections (host:d,``reverse``), the d argument is a TCP port
2463 number, not a display number.
2464
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002465 ``websocket=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002466 Opens an additional TCP listening port dedicated to VNC
2467 Websocket connections. If a bare websocket option is given, the
2468 Websocket port is 5700+display. An alternative port can be
2469 specified with the syntax ``websocket``\ =port.
2470
2471 If host is specified connections will only be allowed from this
2472 host. It is possible to control the websocket listen address
2473 independently, using the syntax ``websocket``\ =host:port.
2474
Sergii Zasenko41582632023-07-24 13:03:53 +03002475 Websocket could be allowed over UNIX domain socket, using the syntax
2476 ``websocket``\ =unix:path, where path is the location of a unix socket
2477 to listen for connections on.
2478
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002479 If no TLS credentials are provided, the websocket connection
2480 runs in unencrypted mode. If TLS credentials are provided, the
2481 websocket connection requires encrypted client connections.
2482
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002483 ``password=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002484 Require that password based authentication is used for client
2485 connections.
2486
2487 The password must be set separately using the ``set_password``
Thomas Huth923e9312020-11-16 15:47:36 +01002488 command in the :ref:`QEMU monitor`. The
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002489 syntax to change your password is:
2490 ``set_password <protocol> <password>`` where <protocol> could be
2491 either "vnc" or "spice".
2492
2493 If you would like to change <protocol> password expiration, you
2494 should use ``expire_password <protocol> <expiration-time>``
2495 where expiration time could be one of the following options:
2496 now, never, +seconds or UNIX time of expiration, e.g. +60 to
2497 make password expire in 60 seconds, or 1335196800 to make
2498 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for
2499 this date and time).
2500
2501 You can also use keywords "now" or "never" for the expiration
2502 time to allow <protocol> password to expire immediately or never
2503 expire.
2504
Daniel P. Berrangé6c6840e2021-03-11 11:43:41 +00002505 ``password-secret=<secret-id>``
2506 Require that password based authentication is used for client
2507 connections, using the password provided by the ``secret``
2508 object identified by ``secret-id``.
2509
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002510 ``tls-creds=ID``
2511 Provides the ID of a set of TLS credentials to use to secure the
2512 VNC server. They will apply to both the normal VNC server socket
2513 and the websocket socket (if enabled). Setting TLS credentials
2514 will cause the VNC server socket to enable the VeNCrypt auth
2515 mechanism. The credentials should have been previously created
2516 using the ``-object tls-creds`` argument.
2517
2518 ``tls-authz=ID``
2519 Provides the ID of the QAuthZ authorization object against which
2520 the client's x509 distinguished name will validated. This object
2521 is only resolved at time of use, so can be deleted and recreated
2522 on the fly while the VNC server is active. If missing, it will
2523 default to denying access.
2524
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002525 ``sasl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002526 Require that the client use SASL to authenticate with the VNC
2527 server. The exact choice of authentication method used is
2528 controlled from the system / user's SASL configuration file for
2529 the 'qemu' service. This is typically found in
2530 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user,
2531 an environment variable SASL\_CONF\_PATH can be used to make it
2532 search alternate locations for the service config. While some
2533 SASL auth methods can also provide data encryption (eg GSSAPI),
2534 it is recommended that SASL always be combined with the 'tls'
2535 and 'x509' settings to enable use of SSL and server
2536 certificates. This ensures a data encryption preventing
2537 compromise of authentication credentials. See the
Thomas Huth923e9312020-11-16 15:47:36 +01002538 :ref:`VNC security` section in the System Emulation Users Guide
2539 for details on using SASL authentication.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002540
2541 ``sasl-authz=ID``
2542 Provides the ID of the QAuthZ authorization object against which
2543 the client's SASL username will validated. This object is only
2544 resolved at time of use, so can be deleted and recreated on the
2545 fly while the VNC server is active. If missing, it will default
2546 to denying access.
2547
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002548 ``acl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002549 Legacy method for enabling authorization of clients against the
2550 x509 distinguished name and SASL username. It results in the
2551 creation of two ``authz-list`` objects with IDs of
2552 ``vnc.username`` and ``vnc.x509dname``. The rules for these
2553 objects must be configured with the HMP ACL commands.
2554
2555 This option is deprecated and should no longer be used. The new
2556 ``sasl-authz`` and ``tls-authz`` options are a replacement.
2557
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002558 ``lossy=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002559 Enable lossy compression methods (gradient, JPEG, ...). If this
2560 option is set, VNC client may receive lossy framebuffer updates
2561 depending on its encoding settings. Enabling this option can
2562 save a lot of bandwidth at the expense of quality.
2563
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002564 ``non-adaptive=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002565 Disable adaptive encodings. Adaptive encodings are enabled by
2566 default. An adaptive encoding will try to detect frequently
2567 updated screen regions, and send updates in these regions using
2568 a lossy encoding (like JPEG). This can be really helpful to save
2569 bandwidth when playing videos. Disabling adaptive encodings
2570 restores the original static behavior of encodings like Tight.
2571
2572 ``share=[allow-exclusive|force-shared|ignore]``
2573 Set display sharing policy. 'allow-exclusive' allows clients to
2574 ask for exclusive access. As suggested by the rfb spec this is
2575 implemented by dropping other connections. Connecting multiple
2576 clients in parallel requires all clients asking for a shared
2577 session (vncviewer: -shared switch). This is the default.
2578 'force-shared' disables exclusive client access. Useful for
2579 shared desktop sessions, where you don't want someone forgetting
2580 specify -shared disconnect everybody else. 'ignore' completely
2581 ignores the shared flag and allows everybody connect
2582 unconditionally. Doesn't conform to the rfb spec but is
2583 traditional QEMU behavior.
2584
2585 ``key-delay-ms``
2586 Set keyboard delay, for key down and key up events, in
2587 milliseconds. Default is 10. Keyboards are low-bandwidth
2588 devices, so this slowdown can help the device and guest to keep
2589 up and not lose events in case events are arriving in bulk.
2590 Possible causes for the latter are flaky network connections, or
2591 scripts for automated testing.
2592
2593 ``audiodev=audiodev``
2594 Use the specified audiodev when the VNC client requests audio
2595 transmission. When not using an -audiodev argument, this option
2596 must be omitted, otherwise is must be present and specify a
2597 valid audiodev.
Daniel P. Berrangé7b5fa0b2020-12-11 16:08:25 +00002598
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002599 ``power-control=on|off``
Daniel P. Berrangé7b5fa0b2020-12-11 16:08:25 +00002600 Permit the remote client to issue shutdown, reboot or reset power
2601 control requests.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002602ERST
blueswir15824d652009-03-28 06:44:27 +00002603
Michael Ellermana3adb7a2011-12-19 17:19:31 +11002604ARCHHEADING(, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002605
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002606ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002607
blueswir15824d652009-03-28 06:44:27 +00002608DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
Blue Swirlad960902010-03-29 19:23:52 +00002609 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
2610 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002611SRST
2612``-win2k-hack``
2613 Use it when installing Windows 2000 to avoid a disk full bug. After
2614 Windows 2000 is installed, you no longer need this option (this
Paolo Bonzinid13f4032024-02-20 17:09:30 +01002615 option slows down the IDE transfers). Synonym of ``-global
2616 ide-device.win2k-install-hack=on``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002617ERST
blueswir15824d652009-03-28 06:44:27 +00002618
blueswir15824d652009-03-28 06:44:27 +00002619DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
Blue Swirlad960902010-03-29 19:23:52 +00002620 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
2621 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002622SRST
2623``-no-fd-bootchk``
2624 Disable boot signature checking for floppy disks in BIOS. May be
Paolo Bonzini84e945a2024-02-13 10:56:56 +01002625 needed to boot from old floppy disks. Synonym of ``-m fd-bootchk=off``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002626ERST
blueswir15824d652009-03-28 06:44:27 +00002627
blueswir15824d652009-03-28 06:44:27 +00002628DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
Michael Tokarev104bf022011-05-12 18:44:17 +04002629 "-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 +00002630 " ACPI table description\n", QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002631SRST
2632``-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]...]``
2633 Add ACPI table with specified header fields and context from
2634 specified files. For file=, take whole ACPI table from the specified
2635 files, including all ACPI headers (possible overridden by other
2636 options). For data=, only data portion of the table is used, all
2637 header information is specified in the command line. If a SLIC table
2638 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id
2639 fields will override the same in the RSDT and the FADT (a.k.a.
2640 FACP), in order to ensure the field matches required by the
2641 Microsoft SLIC spec and the ACPI spec.
2642ERST
blueswir15824d652009-03-28 06:44:27 +00002643
aliguorib6f6e3d2009-04-17 18:59:56 +00002644DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
2645 "-smbios file=binary\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002646 " load SMBIOS entry from binary file\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002647 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
2648 " [,uefi=on|off]\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002649 " specify SMBIOS type 0 fields\n"
aliguorib6f6e3d2009-04-17 18:59:56 +00002650 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2651 " [,uuid=uuid][,sku=str][,family=str]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002652 " specify SMBIOS type 1 fields\n"
2653 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2654 " [,asset=str][,location=str]\n"
2655 " specify SMBIOS type 2 fields\n"
2656 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
2657 " [,sku=str]\n"
2658 " specify SMBIOS type 3 fields\n"
2659 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
Ying Fangc906e032020-08-06 11:56:33 +08002660 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n"
Heinrich Schuchardt68baeaa2024-07-29 22:48:15 +02002661 " [,processor-family=%d][,processor-id=%d]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002662 " specify SMBIOS type 4 fields\n"
Hal Martinfd8caa22022-08-12 15:51:53 +02002663 "-smbios type=8[,external_reference=str][,internal_reference=str][,connector_type=%d][,port_type=%d]\n"
2664 " specify SMBIOS type 8 fields\n"
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002665 "-smbios type=11[,value=str][,path=filename]\n"
2666 " specify SMBIOS type 11 fields\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002667 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
Gabriel L. Somlo3ebd6cc2015-03-11 13:58:01 -04002668 " [,asset=str][,part=str][,speed=%d]\n"
Vincent Bernat05dfb442021-04-01 19:11:38 +02002669 " specify SMBIOS type 17 fields\n"
2670 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n"
2671 " specify SMBIOS type 41 fields\n",
Heinrich Schuchardte2ff0de2024-01-23 19:42:29 +01002672 QEMU_ARCH_I386 | QEMU_ARCH_ARM | QEMU_ARCH_LOONGARCH | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002673SRST
2674``-smbios file=binary``
2675 Load SMBIOS entry from binary file.
2676
2677``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]``
2678 Specify SMBIOS type 0 fields
2679
2680``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]``
2681 Specify SMBIOS type 1 fields
2682
2683``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]``
2684 Specify SMBIOS type 2 fields
2685
2686``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]``
2687 Specify SMBIOS type 3 fields
2688
Heinrich Schuchardtb5831d72024-01-23 19:42:26 +01002689``-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 +00002690 Specify SMBIOS type 4 fields
2691
Felix Wu04f143d2024-02-21 17:00:27 +00002692``-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 +00002693 Specify SMBIOS type 9 fields
2694
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002695``-smbios type=11[,value=str][,path=filename]``
2696 Specify SMBIOS type 11 fields
2697
2698 This argument can be repeated multiple times, and values are added in the order they are parsed.
2699 Applications intending to use OEM strings data are encouraged to use their application name as
2700 a prefix for the value string. This facilitates passing information for multiple applications
2701 concurrently.
2702
2703 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax
2704 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes.
2705
2706 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to
2707 the SMBIOS table in the order in which they appear.
2708
2709 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535
2710 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the
2711 guest. Instead it should be used as a indicator to inform the guest where to locate the real
2712 data set, for example, by specifying the serial ID of a block device.
2713
2714 An example passing three strings is
2715
2716 .. parsed-literal::
2717
2718 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\
2719 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\
2720 path=/some/file/with/oemstringsdata.txt
2721
2722 In the guest OS this is visible with the ``dmidecode`` command
2723
2724 .. parsed-literal::
2725
2726 $ dmidecode -t 11
2727 Handle 0x0E00, DMI type 11, 5 bytes
2728 OEM Strings
2729 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/
2730 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os
2731 String 3: myapp:some extra data
2732
2733
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002734``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]``
2735 Specify SMBIOS type 17 fields
Vincent Bernat05dfb442021-04-01 19:11:38 +02002736
2737``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]``
2738 Specify SMBIOS type 41 fields
2739
2740 This argument can be repeated multiple times. Its main use is to allow network interfaces be created
2741 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface
2742 position on the PCI bus.
2743
2744 Here is an example of use:
2745
2746 .. parsed-literal::
2747
2748 -netdev user,id=internet \\
2749 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\
2750 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev
2751
2752 In the guest OS, the device should then appear as ``eno1``:
2753
2754 ..parsed-literal::
2755
2756 $ ip -brief l
2757 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP>
2758 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP>
2759
2760 Currently, the PCI device has to be attached to the root bus.
2761
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002762ERST
aliguorib6f6e3d2009-04-17 18:59:56 +00002763
Markus Armbrusterc70a01e2013-02-13 19:49:40 +01002764DEFHEADING()
blueswir15824d652009-03-28 06:44:27 +00002765
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002766DEFHEADING(Network options:)
blueswir15824d652009-03-28 06:44:27 +00002767
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002768DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
blueswir15824d652009-03-28 06:44:27 +00002769#ifdef CONFIG_SLIRP
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00002770 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n"
2771 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
Samuel Thibault0b11c032016-03-20 12:29:54 +01002772 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
Benjamin Drungf18d1372018-02-27 17:06:01 +01002773 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
Fam Zheng0fca92b2018-09-14 15:26:16 +08002774 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002775#ifndef _WIN32
Jan Kiszkac92ef6a2009-06-24 14:42:28 +02002776 "[,smb=dir[,smbserver=addr]]\n"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002777#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002778 " configure a user mode network backend with ID 'str',\n"
2779 " its DHCP server and optional services\n"
blueswir15824d652009-03-28 06:44:27 +00002780#endif
2781#ifdef _WIN32
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002782 "-netdev tap,id=str,ifname=name\n"
2783 " configure a host TAP network backend with ID 'str'\n"
blueswir15824d652009-03-28 06:44:27 +00002784#else
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002785 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002786 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002787 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002788 " [,poll-us=n]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002789 " configure a host TAP network backend with ID 'str'\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002790 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002791 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
2792 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
2793 " to deconfigure it\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002794 " use '[down]script=no' to disable script execution\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002795 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
2796 " configure it\n"
blueswir15824d652009-03-28 06:44:27 +00002797 " use 'fd=h' to connect to an already opened TAP interface\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002798 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002799 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
Michael S. Tsirkinf157ed22011-02-01 14:25:40 +02002800 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002801 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
2802 " 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 +02002803 " use vhost=on to enable experimental in kernel accelerator\n"
mst@redhat.com5430a282011-02-01 22:13:42 +02002804 " (only has effect for virtio guests which use MSIX)\n"
2805 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
Michael S. Tsirkin82b0d802010-03-17 13:08:24 +02002806 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002807 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
Jason Wangec396012013-02-22 22:57:52 +08002808 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
Michael Tokarevcba42d62021-03-09 14:15:10 +03002809 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002810 " spent on busy polling for vhost net\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002811 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
2812 " configure a host TAP network backend with ID 'str' that is\n"
2813 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
2814 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
Mark McLoughlin0df0ff62009-06-18 18:21:34 +01002815#endif
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002816#ifdef __linux__
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002817 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00002818 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n"
2819 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002820 " [,rxcookie=rxcookie][,offset=offset]\n"
2821 " configure a network backend with ID 'str' connected to\n"
2822 " an Ethernet over L2TPv3 pseudowire.\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002823 " Linux kernel 3.3+ as well as most routers can talk\n"
Michael Tokarev2f47b402014-07-24 20:10:17 +04002824 " L2TPv3. This transport allows connecting a VM to a VM,\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002825 " VM to a router and even VM to Host. It is a nearly-universal\n"
Stefan Hajnoczi21843dc2020-02-29 11:17:27 +00002826 " standard (RFC3931). Note - this implementation uses static\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002827 " pre-configured tunnels (same as the Linux kernel).\n"
2828 " use 'src=' to specify source address\n"
2829 " use 'dst=' to specify destination address\n"
2830 " use 'udp=on' to specify udp encapsulation\n"
Gonglei39526512014-08-14 14:35:48 +08002831 " use 'srcport=' to specify source udp port\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002832 " use 'dstport=' to specify destination udp port\n"
2833 " use 'ipv6=on' to force v6\n"
2834 " L2TPv3 uses cookies to prevent misconfiguration as\n"
2835 " well as a weak security measure\n"
2836 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
2837 " use 'txcookie=0x012345678' to specify a txcookie\n"
2838 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
2839 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
2840 " use 'pincounter=on' to work around broken counter handling in peer\n"
2841 " use 'offset=X' to add an extra offset between header and data\n"
2842#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002843 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
2844 " configure a network backend to connect to another network\n"
2845 " using a socket connection\n"
2846 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
2847 " configure a network backend to connect to a multicast maddr and port\n"
Mike Ryan3a75e742010-12-01 11:16:47 -08002848 " use 'localaddr=addr' to specify the host address to send packets from\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002849 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
2850 " configure a network backend to connect to another network\n"
2851 " using an UDP tunnel\n"
Laurent Vivier148fbf02023-01-19 11:16:45 +01002852 "-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=seconds]\n"
2853 "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect=seconds]\n"
2854 "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect=seconds]\n"
Laurent Vivier5166fe02022-10-21 11:09:11 +02002855 " configure a network backend to connect to another network\n"
2856 " using a socket connection in stream mode.\n"
2857 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n"
2858 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]\n"
2859 " configure a network backend to connect to a multicast maddr and port\n"
2860 " use ``local.host=addr`` to specify the host address to send packets from\n"
2861 "-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 +02002862 "-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]\n"
Laurent Vivier5166fe02022-10-21 11:09:11 +02002863 "-netdev dgram,id=str,local.type=fd,local.str=file-descriptor\n"
2864 " configure a network backend to connect to another network\n"
2865 " using an UDP tunnel\n"
blueswir15824d652009-03-28 06:44:27 +00002866#ifdef CONFIG_VDE
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002867 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
2868 " configure a network backend to connect to port 'n' of a vde switch\n"
2869 " running on host and listening for incoming connections on 'socketpath'.\n"
blueswir15824d652009-03-28 06:44:27 +00002870 " Use group 'groupname' and mode 'octalmode' to change default\n"
2871 " ownership and permissions for communication port.\n"
2872#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002873#ifdef CONFIG_NETMAP
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002874 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
Vincenzo Maffione58952132013-11-06 11:44:06 +01002875 " attach to the existing netmap-enabled network interface 'name', or to a\n"
2876 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
2877 " netmap device, defaults to '/dev/netmap')\n"
2878#endif
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002879#ifdef CONFIG_AF_XDP
2880 "-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off]\n"
2881 " [,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]\n"
2882 " attach to the existing network interface 'name' with AF_XDP socket\n"
2883 " use 'mode=MODE' to specify an XDP program attach mode\n"
2884 " use 'force-copy=on|off' to force XDP copy mode even if device supports zero-copy (default: off)\n"
2885 " use 'inhibit=on|off' to inhibit loading of a default XDP program (default: off)\n"
2886 " with inhibit=on,\n"
2887 " use 'sock-fds' to provide file descriptors for already open AF_XDP sockets\n"
2888 " added to a socket map in XDP program. One socket per queue.\n"
2889 " use 'queues=n' to specify how many queues of a multiqueue interface should be used\n"
2890 " use 'start-queue=m' to specify the first queue that should be used\n"
2891#endif
Thomas Huth253dc142018-02-21 11:18:32 +01002892#ifdef CONFIG_POSIX
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002893 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2894 " configure a vhost-user network, backed by a chardev 'dev'\n"
Thomas Huth253dc142018-02-21 11:18:32 +01002895#endif
Cindy Lu108a6482020-07-01 22:55:37 +08002896#ifdef __linux__
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07002897 "-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n"
Cindy Lu108a6482020-07-01 22:55:37 +08002898 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n"
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07002899 " use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n"
2900 " use 'vhostfd=h' to connect to an already opened vhost vdpa device\n"
Cindy Lu108a6482020-07-01 22:55:37 +08002901#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002902#ifdef CONFIG_VMNET
2903 "-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n"
2904 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n"
2905 " configure a vmnet network backend in host mode with ID 'str',\n"
2906 " isolate this interface from others with 'isolated',\n"
2907 " configure the address range and choose a subnet mask,\n"
2908 " specify network UUID 'uuid' to disable DHCP and interact with\n"
2909 " vmnet-host interfaces within this isolated network\n"
2910 "-netdev vmnet-shared,id=str[,isolated=on|off][,nat66-prefix=addr]\n"
2911 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n"
2912 " configure a vmnet network backend in shared mode with ID 'str',\n"
2913 " configure the address range and choose a subnet mask,\n"
2914 " set IPv6 ULA prefix (of length 64) to use for internal network,\n"
2915 " isolate this interface from others with 'isolated'\n"
2916 "-netdev vmnet-bridged,id=str,ifname=name[,isolated=on|off]\n"
2917 " configure a vmnet network backend in bridged mode with ID 'str',\n"
2918 " use 'ifname=name' to select a physical network interface to be bridged,\n"
2919 " isolate this interface from others with 'isolated'\n"
2920#endif
Thomas Huth18d65d22018-01-15 20:50:55 +01002921 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002922 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
Thomas Huth78cd6f72018-02-21 11:18:36 +01002923DEF("nic", HAS_ARG, QEMU_OPTION_nic,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002924 "-nic [tap|bridge|"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002925#ifdef CONFIG_SLIRP
2926 "user|"
2927#endif
2928#ifdef __linux__
2929 "l2tpv3|"
2930#endif
2931#ifdef CONFIG_VDE
2932 "vde|"
2933#endif
2934#ifdef CONFIG_NETMAP
2935 "netmap|"
2936#endif
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002937#ifdef CONFIG_AF_XDP
2938 "af-xdp|"
2939#endif
Thomas Huth78cd6f72018-02-21 11:18:36 +01002940#ifdef CONFIG_POSIX
2941 "vhost-user|"
2942#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002943#ifdef CONFIG_VMNET
2944 "vmnet-host|vmnet-shared|vmnet-bridged|"
2945#endif
Thomas Huth78cd6f72018-02-21 11:18:36 +01002946 "socket][,option][,...][mac=macaddr]\n"
2947 " initialize an on-board / default host NIC (using MAC address\n"
2948 " macaddr) and connect it to the given host network backend\n"
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002949 "-nic none use it alone to have zero network devices (the default is to\n"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002950 " provided a 'user' network connection)\n",
2951 QEMU_ARCH_ALL)
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002952DEF("net", HAS_ARG, QEMU_OPTION_net,
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002953 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
Thomas Huth0e60a822017-12-19 16:28:55 +01002954 " configure or create an on-board (or machine default) NIC and\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002955 " connect it to hub 0 (please use -nic unless you need a hub)\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002956 "-net ["
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002957#ifdef CONFIG_SLIRP
2958 "user|"
2959#endif
2960 "tap|"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002961 "bridge|"
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002962#ifdef CONFIG_VDE
2963 "vde|"
2964#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002965#ifdef CONFIG_NETMAP
2966 "netmap|"
2967#endif
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002968#ifdef CONFIG_AF_XDP
2969 "af-xdp|"
2970#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002971#ifdef CONFIG_VMNET
2972 "vmnet-host|vmnet-shared|vmnet-bridged|"
2973#endif
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002974 "socket][,option][,option][,...]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002975 " old way to initialize a host network interface\n"
2976 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002977SRST
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002978``-nic [tap|bridge|user|l2tpv3|vde|netmap|af-xdp|vhost-user|socket][,...][,mac=macaddr][,model=mn]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002979 This option is a shortcut for configuring both the on-board
2980 (default) guest NIC hardware and the host network backend in one go.
2981 The host backend options are the same as with the corresponding
2982 ``-netdev`` options below. The guest NIC model can be set with
2983 ``model=modelname``. Use ``model=help`` to list the available device
2984 types. The hardware MAC address can be set with ``mac=macaddr``.
2985
2986 The following two example do exactly the same, to show how ``-nic``
2987 can be used to shorten the command line length:
2988
2989 .. parsed-literal::
2990
2991 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
2992 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2993
2994``-nic none``
2995 Indicate that no network devices should be configured. It is used to
2996 override the default configuration (default NIC with "user" host
2997 network backend) which is activated if no other networking options
2998 are provided.
2999
3000``-netdev user,id=id[,option][,option][,...]``
3001 Configure user mode host network backend which requires no
3002 administrator privilege to run. Valid options are:
3003
3004 ``id=id``
3005 Assign symbolic name for use in monitor commands.
3006
3007 ``ipv4=on|off and ipv6=on|off``
3008 Specify that either IPv4 or IPv6 must be enabled. If neither is
3009 specified both protocols are enabled.
3010
3011 ``net=addr[/mask]``
3012 Set IP network address the guest will see. Optionally specify
3013 the netmask, either in the form a.b.c.d or as number of valid
3014 top-most bits. Default is 10.0.2.0/24.
3015
3016 ``host=addr``
3017 Specify the guest-visible address of the host. Default is the
3018 2nd IP in the guest network, i.e. x.x.x.2.
3019
3020 ``ipv6-net=addr[/int]``
3021 Set IPv6 network address the guest will see (default is
3022 fec0::/64). The network prefix is given in the usual hexadecimal
3023 IPv6 address notation. The prefix size is optional, and is given
3024 as the number of valid top-most bits (default is 64).
3025
3026 ``ipv6-host=addr``
3027 Specify the guest-visible IPv6 address of the host. Default is
3028 the 2nd IPv6 in the guest network, i.e. xxxx::2.
3029
3030 ``restrict=on|off``
3031 If this option is enabled, the guest will be isolated, i.e. it
3032 will not be able to contact the host and no guest IP packets
3033 will be routed over the host to the outside. This option does
3034 not affect any explicitly set forwarding rules.
3035
3036 ``hostname=name``
3037 Specifies the client hostname reported by the built-in DHCP
3038 server.
3039
3040 ``dhcpstart=addr``
3041 Specify the first of the 16 IPs the built-in DHCP server can
3042 assign. Default is the 15th to 31st IP in the guest network,
3043 i.e. x.x.x.15 to x.x.x.31.
3044
3045 ``dns=addr``
3046 Specify the guest-visible address of the virtual nameserver. The
3047 address must be different from the host address. Default is the
3048 3rd IP in the guest network, i.e. x.x.x.3.
3049
3050 ``ipv6-dns=addr``
3051 Specify the guest-visible address of the IPv6 virtual
3052 nameserver. The address must be different from the host address.
3053 Default is the 3rd IP in the guest network, i.e. xxxx::3.
3054
3055 ``dnssearch=domain``
3056 Provides an entry for the domain-search list sent by the
3057 built-in DHCP server. More than one domain suffix can be
3058 transmitted by specifying this option multiple times. If
3059 supported, this will cause the guest to automatically try to
3060 append the given domain suffix(es) in case a domain name can not
3061 be resolved.
3062
3063 Example:
3064
3065 .. parsed-literal::
3066
3067 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
3068
3069 ``domainname=domain``
3070 Specifies the client domain name reported by the built-in DHCP
3071 server.
3072
3073 ``tftp=dir``
3074 When using the user mode network stack, activate a built-in TFTP
3075 server. The files in dir will be exposed as the root of a TFTP
3076 server. The TFTP client on the guest must be configured in
3077 binary mode (use the command ``bin`` of the Unix TFTP client).
Michael Tokarevb30fa6b2024-02-08 09:00:50 +03003078 The built-in TFTP server is read-only; it does not implement any
3079 command for writing files. QEMU will not write to this directory.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003080
3081 ``tftp-server-name=name``
3082 In BOOTP reply, broadcast name as the "TFTP server name"
3083 (RFC2132 option 66). This can be used to advise the guest to
3084 load boot files or configurations from a different server than
3085 the host address.
3086
3087 ``bootfile=file``
3088 When using the user mode network stack, broadcast file as the
3089 BOOTP filename. In conjunction with ``tftp``, this can be used
3090 to network boot a guest from a local directory.
3091
3092 Example (using pxelinux):
3093
3094 .. parsed-literal::
3095
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003096 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003097 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
3098
3099 ``smb=dir[,smbserver=addr]``
3100 When using the user mode network stack, activate a built-in SMB
3101 server so that Windows OSes can access to the host files in
3102 ``dir`` transparently. The IP address of the SMB server can be
3103 set to addr. By default the 4th IP in the guest network is used,
3104 i.e. x.x.x.4.
3105
3106 In the guest Windows OS, the line:
3107
3108 ::
3109
3110 10.0.2.4 smbserver
3111
3112 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows
3113 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows
3114 NT/2000).
3115
3116 Then ``dir`` can be accessed in ``\\smbserver\qemu``.
3117
3118 Note that a SAMBA server must be installed on the host OS.
3119
3120 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport``
3121 Redirect incoming TCP or UDP connections to the host port
3122 hostport to the guest IP address guestaddr on guest port
3123 guestport. If guestaddr is not specified, its value is x.x.x.15
3124 (default first address given by the built-in DHCP server). By
3125 specifying hostaddr, the rule can be bound to a specific host
3126 interface. If no connection type is set, TCP is used. This
3127 option can be given multiple times.
3128
3129 For example, to redirect host X11 connection from screen 1 to
3130 guest screen 0, use the following:
3131
Peter Maydell09ce5f22020-02-28 15:36:13 +00003132 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003133
3134 # on the host
3135 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
3136 # this host xterm should open in the guest X11 server
3137 xterm -display :1
3138
3139 To redirect telnet connections from host port 5555 to telnet
3140 port on the guest, use the following:
3141
Peter Maydell09ce5f22020-02-28 15:36:13 +00003142 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003143
3144 # on the host
3145 |qemu_system| -nic user,hostfwd=tcp::5555-:23
3146 telnet localhost 5555
3147
3148 Then when you use on the host ``telnet localhost 5555``, you
3149 connect to the guest telnet server.
3150
3151 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command``
3152 Forward guest TCP connections to the IP address server on port
3153 port to the character device dev or to a program executed by
3154 cmd:command which gets spawned for each connection. This option
3155 can be given multiple times.
3156
3157 You can either use a chardev directly and have that one used
3158 throughout QEMU's lifetime, like in the following example:
3159
Peter Maydell09ce5f22020-02-28 15:36:13 +00003160 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003161
3162 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
3163 # the guest accesses it
3164 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
3165
3166 Or you can execute a command on every TCP connection established
3167 by the guest, so that QEMU behaves similar to an inetd process
3168 for that virtual server:
3169
Peter Maydell09ce5f22020-02-28 15:36:13 +00003170 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003171
3172 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
3173 # and connect the TCP stream to its stdin/stdout
3174 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
3175
3176``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]``
3177 Configure a host TAP network backend with ID id.
3178
3179 Use the network script file to configure it and the network script
3180 dfile to deconfigure it. If name is not provided, the OS
3181 automatically provides one. The default network configure script is
3182 ``/etc/qemu-ifup`` and the default network deconfigure script is
3183 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to
3184 disable script execution.
3185
3186 If running QEMU as an unprivileged user, use the network helper
Tianjia Zhang8d73ec82020-07-27 12:59:25 +08003187 to configure the TAP interface and attach it to the bridge.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003188 The default network helper executable is
3189 ``/path/to/qemu-bridge-helper`` and the default bridge device is
3190 ``br0``.
3191
3192 ``fd``\ =h can be used to specify the handle of an already opened
3193 host TAP interface.
3194
3195 Examples:
3196
Peter Maydell09ce5f22020-02-28 15:36:13 +00003197 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003198
3199 #launch a QEMU instance with the default network script
3200 |qemu_system| linux.img -nic tap
3201
Peter Maydell09ce5f22020-02-28 15:36:13 +00003202 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003203
3204 #launch a QEMU instance with two NICs, each one connected
3205 #to a TAP device
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003206 |qemu_system| linux.img \\
3207 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003208 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
3209
Peter Maydell09ce5f22020-02-28 15:36:13 +00003210 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003211
3212 #launch a QEMU instance with the default network helper to
3213 #connect a TAP device to bridge br0
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003214 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003215 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
3216
3217``-netdev bridge,id=id[,br=bridge][,helper=helper]``
3218 Connect a host TAP network interface to a host bridge device.
3219
3220 Use the network helper helper to configure the TAP interface and
3221 attach it to the bridge. The default network helper executable is
3222 ``/path/to/qemu-bridge-helper`` and the default bridge device is
3223 ``br0``.
3224
3225 Examples:
3226
Peter Maydell09ce5f22020-02-28 15:36:13 +00003227 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003228
3229 #launch a QEMU instance with the default network helper to
3230 #connect a TAP device to bridge br0
3231 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
3232
Peter Maydell09ce5f22020-02-28 15:36:13 +00003233 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003234
3235 #launch a QEMU instance with the default network helper to
3236 #connect a TAP device to bridge qemubr0
3237 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
3238
3239``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]``
3240 This host network backend can be used to connect the guest's network
3241 to another QEMU virtual machine using a TCP socket connection. If
3242 ``listen`` is specified, QEMU waits for incoming connections on port
3243 (host is optional). ``connect`` is used to connect to another QEMU
3244 instance using the ``listen`` option. ``fd``\ =h specifies an
3245 already opened TCP socket.
3246
3247 Example:
3248
Peter Maydell09ce5f22020-02-28 15:36:13 +00003249 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003250
3251 # launch a first QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003252 |qemu_system| linux.img \\
3253 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003254 -netdev socket,id=n1,listen=:1234
3255 # connect the network of this instance to the network of the first instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003256 |qemu_system| linux.img \\
3257 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003258 -netdev socket,id=n2,connect=127.0.0.1:1234
3259
3260``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]``
3261 Configure a socket host network backend to share the guest's network
3262 traffic with another QEMU virtual machines using a UDP multicast
3263 socket, effectively making a bus for every QEMU with same multicast
3264 address maddr and port. NOTES:
3265
3266 1. Several QEMU can be running on different hosts and share same bus
3267 (assuming correct multicast setup for these hosts).
3268
3269 2. mcast support is compatible with User Mode Linux (argument
3270 ``ethN=mcast``), see http://user-mode-linux.sf.net.
3271
3272 3. Use ``fd=h`` to specify an already opened UDP multicast socket.
3273
3274 Example:
3275
Peter Maydell09ce5f22020-02-28 15:36:13 +00003276 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003277
3278 # launch one QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003279 |qemu_system| linux.img \\
3280 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003281 -netdev socket,id=n1,mcast=230.0.0.1:1234
3282 # launch another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003283 |qemu_system| linux.img \\
3284 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003285 -netdev socket,id=n2,mcast=230.0.0.1:1234
3286 # launch yet another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003287 |qemu_system| linux.img \\
3288 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003289 -netdev socket,id=n3,mcast=230.0.0.1:1234
3290
3291 Example (User Mode Linux compat.):
3292
Peter Maydell09ce5f22020-02-28 15:36:13 +00003293 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003294
3295 # launch QEMU instance (note mcast address selected is UML's default)
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003296 |qemu_system| linux.img \\
3297 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003298 -netdev socket,id=n1,mcast=239.192.168.1:1102
3299 # launch UML
3300 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
3301
3302 Example (send packets from host's 1.2.3.4):
3303
3304 .. parsed-literal::
3305
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003306 |qemu_system| linux.img \\
3307 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003308 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
3309
Laurent Vivierf6a31582024-07-04 14:48:34 +02003310``-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=seconds]``
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003311 Configure a network backend to connect to another QEMU virtual machine or a proxy using a TCP/IP socket.
3312
3313 ``server=on|off``
3314 if ``on`` create a server socket
3315
3316 ``addr.host=host,addr.port=port``
3317 socket address to listen on (server=on) or connect to (server=off)
3318
3319 ``to=maxport``
3320 if present, this is range of possible addresses, with port between ``port`` and ``maxport``.
3321
3322 ``numeric=on|off``
3323 if ``on`` ``host`` and ``port`` are guaranteed to be numeric, otherwise a name resolution should be attempted (default: ``off``)
3324
3325 ``keep-alive=on|off``
3326 enable keep-alive when connecting to this socket. Not supported for passive sockets.
3327
3328 ``mptcp=on|off``
3329 enable multipath TCP
3330
3331 ``ipv4=on|off``
3332 whether to accept IPv4 addresses, default to try both IPv4 and IPv6
3333
3334 ``ipv6=on|off``
3335 whether to accept IPv6 addresses, default to try both IPv4 and IPv6
3336
Laurent Vivierf6a31582024-07-04 14:48:34 +02003337 ``reconnect=seconds``
3338 for a client socket, if a socket is disconnected, then attempt a reconnect after the given number of seconds.
3339 Setting this to zero disables this function. (default: 0)
3340
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003341 Example (two guests connected using a TCP/IP socket):
3342
3343 .. parsed-literal::
3344
3345 # first VM
3346 |qemu_system| linux.img \\
3347 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3348 -netdev stream,id=net0,server=on,addr.type=inet,addr.host=localhost,addr.port=1234
3349 # second VM
3350 |qemu_system| linux.img \\
3351 -device virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
Laurent Vivierf6a31582024-07-04 14:48:34 +02003352 -netdev stream,id=net0,server=off,addr.type=inet,addr.host=localhost,addr.port=1234,reconnect=5
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003353
Laurent Vivierf6a31582024-07-04 14:48:34 +02003354``-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect=seconds]``
Laurent Vivier178413a2024-07-04 14:48:32 +02003355 Configure a network backend to connect to another QEMU virtual machine or a proxy using a stream oriented unix domain socket.
3356
3357 ``server=on|off``
3358 if ``on`` create a server socket
3359
3360 ``addr.path=path``
3361 filesystem path to use
3362
3363 ``abstract=on|off``
3364 if ``on``, this is a Linux abstract socket address.
3365
3366 ``tight=on|off``
3367 if false, pad an abstract socket address with enough null bytes to make it fill struct sockaddr_un member sun_path.
3368
Laurent Vivierf6a31582024-07-04 14:48:34 +02003369 ``reconnect=seconds``
3370 for a client socket, if a socket is disconnected, then attempt a reconnect after the given number of seconds.
3371 Setting this to zero disables this function. (default: 0)
3372
Laurent Vivier178413a2024-07-04 14:48:32 +02003373 Example (using passt as a replacement of -netdev user):
3374
3375 .. parsed-literal::
3376
3377 # start passt server as a non privileged user
3378 passt
3379 UNIX domain socket bound at /tmp/passt_1.socket
3380 # start QEMU to connect to passt
3381 |qemu_system| linux.img \\
3382 -device virtio-net,netdev=net0 \\
3383 -netdev stream,id=net0,server=off,addr.type=unix,addr.path=/tmp/passt_1.socket
3384
3385 Example (two guests connected using a stream oriented unix domain socket):
3386
3387 .. parsed-literal::
3388
3389 # first VM
3390 |qemu_system| linux.img \\
3391 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3392 netdev stream,id=net0,server=on,addr.type=unix,addr.path=/tmp/qemu0
3393 # second VM
3394 |qemu_system| linux.img \\
3395 -device virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
Laurent Vivierf6a31582024-07-04 14:48:34 +02003396 -netdev stream,id=net0,server=off,addr.type=unix,addr.path=/tmp/qemu0,reconnect=5
Laurent Vivier178413a2024-07-04 14:48:32 +02003397
Laurent Vivierf6a31582024-07-04 14:48:34 +02003398``-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect=seconds]``
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003399 Configure a network backend to connect to another QEMU virtual machine or a proxy using a stream oriented socket file descriptor.
3400
3401 ``server=on|off``
3402 if ``on`` create a server socket
3403
3404 ``addr.str=file-descriptor``
3405 file descriptor number to use as a socket
3406
Laurent Vivierf6a31582024-07-04 14:48:34 +02003407 ``reconnect=seconds``
3408 for a client socket, if a socket is disconnected, then attempt a reconnect after the given number of seconds.
3409 Setting this to zero disables this function. (default: 0)
3410
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003411``-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]``
3412 Configure a network backend to connect to a multicast address.
3413
3414 ``remote.host=maddr,remote.port=port``
3415 multicast address
3416
3417 ``local.host=addr``
3418 specify the host address to send packets from
3419
3420 Example:
3421
3422 .. parsed-literal::
3423
3424 # launch one QEMU instance
3425 |qemu_system| linux.img \\
3426 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3427 -netdev dgram,id=net0,remote.type=inet,remote.host=224.0.0.1,remote.port=1234
3428 # launch another QEMU instance on same "bus"
3429 |qemu_system| linux.img \\
3430 -device virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
3431 -netdev dgram,id=net0,remote.type=inet,remote.host=224.0.0.1,remote.port=1234
3432 # launch yet another QEMU instance on same "bus"
3433 |qemu_system| linux.img \\
3434 -device virtio-net,netdev=net0,mac=52:54:00:12:34:58 \\
3435 -netdev dgram,id=net0,remote.type=inet,remote.host=224.0.0.1,remote.port=1234
3436
3437``-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]``
3438 Configure a network backend to connect to a multicast address using a UDP socket file descriptor.
3439
3440 ``remote.host=maddr,remote.port=port``
3441 multicast address
3442
3443 ``local.str=file-descriptor``
3444 File descriptor to use to send packets
3445
3446``-netdev dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]``
3447 Configure a network backend to connect to another QEMU virtual
3448 machine or a proxy using a datagram oriented unix domain socket.
3449
3450 ``local.host=addr,local.port=port``
3451 IP address to use to send the packets from
3452
3453 ``remote.host=addr,remote.port=port``
3454 Destination IP address
3455
3456 Example (two guests connected using an UDP/IP socket):
3457
3458 .. parsed-literal::
3459
3460 # first VM
3461 |qemu_system| linux.img \\
3462 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3463 -netdev dgram,id=net0,local.type=inet,local.host=localhost,local.port=1234,remote.type=inet,remote.host=localhost,remote.port=1235
3464 # second VM
3465 |qemu_system| linux.img \\
3466 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3467 -netdev dgram,id=net0,local.type=inet,local.host=localhost,local.port=1235,remote.type=inet,remote.host=localhost,remote.port=1234
3468
Laurent Vivier8e676802024-07-04 14:48:33 +02003469``-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]``
3470 Configure a network backend to connect to another QEMU virtual
3471 machine or a proxy using a datagram oriented unix socket.
3472
3473 ``local.path=path``
3474 filesystem path to use to bind the socket
3475
3476 ``remote.path=path``
3477 filesystem path to use as a destination (see sendto(2))
3478
3479 Example (two guests connected using an UDP/UNIX socket):
3480
3481 .. parsed-literal::
3482
3483 # first VM
3484 |qemu_system| linux.img \\
3485 -device virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
3486 -netdev dgram,id=net0,local.type=unix,local.path=/tmp/qemu0,remote.type=unix,remote.path=/tmp/qemu1
3487 # second VM
3488 |qemu_system| linux.img \\
3489 -device virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
3490 -netdev dgram,id=net0,local.type=unix,local.path=/tmp/qemu1,remote.type=unix,remote.path=/tmp/qemu0
3491
Laurent Vivierbb1326a2024-07-04 14:48:31 +02003492``-netdev dgram,id=str,local.type=fd,local.str=file-descriptor``
3493 Configure a network backend to connect to another QEMU virtual
3494 machine or a proxy using a datagram oriented socket file descriptor.
3495
3496 ``local.str=file-descriptor``
3497 File descriptor to use to send packets
3498
Zhao Liucb8de742024-07-08 17:26:30 +08003499``-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 +00003500 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931)
3501 is a popular protocol to transport Ethernet (and other Layer 2) data
3502 frames between two systems. It is present in routers, firewalls and
3503 the Linux kernel (from version 3.3 onwards).
3504
3505 This transport allows a VM to communicate to another VM, router or
3506 firewall directly.
3507
3508 ``src=srcaddr``
3509 source address (mandatory)
3510
3511 ``dst=dstaddr``
3512 destination address (mandatory)
3513
Zhao Liucb8de742024-07-08 17:26:30 +08003514 ``udp=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003515 select udp encapsulation (default is ip).
3516
3517 ``srcport=srcport``
3518 source udp port.
3519
3520 ``dstport=dstport``
3521 destination udp port.
3522
Zhao Liucb8de742024-07-08 17:26:30 +08003523 ``ipv6=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003524 force v6, otherwise defaults to v4.
3525
3526 ``rxcookie=rxcookie``; \ ``txcookie=txcookie``
3527 Cookies are a weak form of security in the l2tpv3 specification.
3528 Their function is mostly to prevent misconfiguration. By default
3529 they are 32 bit.
3530
Zhao Liucb8de742024-07-08 17:26:30 +08003531 ``cookie64=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003532 Set cookie size to 64 bit instead of the default 32
3533
3534 ``counter=off``
3535 Force a 'cut-down' L2TPv3 with no counter as in
3536 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
3537
3538 ``pincounter=on``
3539 Work around broken counter handling in peer. This may also help
3540 on networks which have packet reorder.
3541
3542 ``offset=offset``
3543 Add an extra offset between header and data
3544
3545 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to
3546 the bridge br-lan on the remote Linux host 1.2.3.4:
3547
Peter Maydell09ce5f22020-02-28 15:36:13 +00003548 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003549
3550 # Setup tunnel on linux host using raw ip as encapsulation
3551 # on 1.2.3.4
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003552 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 +00003553 encap udp udp_sport 16384 udp_dport 16384
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003554 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003555 0xFFFFFFFF peer_session_id 0xFFFFFFFF
3556 ifconfig vmtunnel0 mtu 1500
3557 ifconfig vmtunnel0 up
3558 brctl addif br-lan vmtunnel0
3559
3560
3561 # on 4.3.2.1
3562 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
3563
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003564 |qemu_system| linux.img -device e1000,netdev=n1 \\
Zhao Liucb8de742024-07-08 17:26:30 +08003565 -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 +00003566
3567``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]``
3568 Configure VDE backend to connect to PORT n of a vde switch running
3569 on host and listening for incoming connections on socketpath. Use
3570 GROUP groupname and MODE octalmode to change default ownership and
3571 permissions for communication port. This option is only available if
3572 QEMU has been compiled with vde support enabled.
3573
3574 Example:
3575
Peter Maydell09ce5f22020-02-28 15:36:13 +00003576 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003577
3578 # launch vde switch
3579 vde_switch -F -sock /tmp/myswitch
3580 # launch QEMU instance
3581 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch
3582
Ilya Maximetscb039ef2023-09-13 20:34:37 +02003583``-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]``
3584 Configure AF_XDP backend to connect to a network interface 'name'
3585 using AF_XDP socket. A specific program attach mode for a default
3586 XDP program can be forced with 'mode', defaults to best-effort,
3587 where the likely most performant mode will be in use. Number of queues
3588 'n' should generally match the number or queues in the interface,
3589 defaults to 1. Traffic arriving on non-configured device queues will
3590 not be delivered to the network backend.
3591
3592 .. parsed-literal::
3593
3594 # set number of queues to 4
3595 ethtool -L eth0 combined 4
3596 # launch QEMU instance
3597 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
3598 -netdev af-xdp,id=n1,ifname=eth0,queues=4
3599
3600 'start-queue' option can be specified if a particular range of queues
3601 [m, m + n] should be in use. For example, this is may be necessary in
3602 order to use certain NICs in native mode. Kernel allows the driver to
3603 create a separate set of XDP queues on top of regular ones, and only
3604 these queues can be used for AF_XDP sockets. NICs that work this way
3605 may also require an additional traffic redirection with ethtool to these
3606 special queues.
3607
3608 .. parsed-literal::
3609
3610 # set number of queues to 1
3611 ethtool -L eth0 combined 1
3612 # redirect all the traffic to the second queue (id: 1)
3613 # note: drivers may require non-empty key/mask pair.
3614 ethtool -N eth0 flow-type ether \\
3615 dst 00:00:00:00:00:00 m FF:FF:FF:FF:FF:FE action 1
3616 ethtool -N eth0 flow-type ether \\
3617 dst 00:00:00:00:00:01 m FF:FF:FF:FF:FF:FE action 1
3618 # launch QEMU instance
3619 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
3620 -netdev af-xdp,id=n1,ifname=eth0,queues=1,start-queue=1
3621
3622 XDP program can also be loaded externally. In this case 'inhibit' option
3623 should be set to 'on' and 'sock-fds' provided with file descriptors for
3624 already open but not bound XDP sockets already added to a socket map for
3625 corresponding queues. One socket per queue.
3626
3627 .. parsed-literal::
3628
3629 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
3630 -netdev af-xdp,id=n1,ifname=eth0,queues=3,inhibit=on,sock-fds=15:16:17
3631
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003632``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]``
3633 Establish a vhost-user netdev, backed by a chardev id. The chardev
3634 should be a unix domain socket backed one. The vhost-user uses a
3635 specifically defined protocol to pass vhost ioctl replacement
3636 messages to an application on the other end of the socket. On
3637 non-MSIX guests, the feature can be forced with vhostforce. Use
3638 'queues=n' to specify the number of queues to be created for
3639 multiqueue vhost-user.
3640
3641 Example:
3642
3643 ::
3644
3645 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
3646 -numa node,memdev=mem \
3647 -chardev socket,id=chr0,path=/path/to/socket \
3648 -netdev type=vhost-user,id=net0,chardev=chr0 \
3649 -device virtio-net-pci,netdev=net0
3650
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07003651``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]``
Cindy Lu108a6482020-07-01 22:55:37 +08003652 Establish a vhost-vdpa netdev.
3653
3654 vDPA device is a device that uses a datapath which complies with
3655 the virtio specifications with a vendor specific control path.
3656 vDPA devices can be both physically located on the hardware or
3657 emulated by software.
3658
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003659``-netdev hubport,id=id,hubid=hubid[,netdev=nd]``
3660 Create a hub port on the emulated hub with ID hubid.
3661
3662 The hubport netdev lets you connect a NIC to a QEMU emulated hub
3663 instead of a single netdev. Alternatively, you can also connect the
3664 hubport to another netdev with ID nd by using the ``netdev=nd``
3665 option.
3666
3667``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]``
3668 Legacy option to configure or create an on-board (or machine
3669 default) Network Interface Card(NIC) and connect it either to the
3670 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd.
3671 If model is omitted, then the default NIC model associated with the
3672 machine type is used. Note that the default NIC model may change in
3673 future QEMU releases, so it is highly recommended to always specify
3674 a model. Optionally, the MAC address can be changed to mac, the
3675 device address set to addr (PCI cards only), and a name can be
3676 assigned for use in monitor commands. Optionally, for PCI cards, you
3677 can specify the number v of MSI-X vectors that the card should have;
3678 this option currently only affects virtio cards; set v = 0 to
3679 disable MSI-X. If no ``-net`` option is specified, a single NIC is
3680 created. QEMU can emulate several different models of network card.
3681 Use ``-net nic,model=help`` for a list of available devices for your
3682 target.
3683
3684``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]``
3685 Configure a host network backend (with the options corresponding to
3686 the same ``-netdev`` option) and connect it to the emulated hub 0
3687 (the default hub). Use name to specify the name of the hub port.
3688ERST
blueswir15824d652009-03-28 06:44:27 +00003689
Matthew Booth7273a2d2009-10-30 13:41:12 +00003690DEFHEADING()
3691
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003692DEFHEADING(Character device options:)
Matthew Booth7273a2d2009-10-30 13:41:12 +00003693
3694DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
Lin Ma517b3d42016-08-17 01:13:52 +08003695 "-chardev help\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003696 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Markus Armbrusterba858d12021-09-28 09:14:49 +02003697 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n"
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003698 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n"
Daniel P. Berrangefd4a5fd2019-03-08 15:21:50 +00003699 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n"
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003700 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n"
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003701 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003702 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003703 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003704 " [,logfile=PATH][,logappend=on|off]\n"
3705 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003706 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003707 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3708 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
Peter Maydell5b18a6b2023-04-13 16:07:24 +01003709 "-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 +00003710 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003711#ifdef _WIN32
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003712 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3713 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003714#else
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003715 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3716 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003717#endif
3718#ifdef CONFIG_BRLAPI
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003719 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003720#endif
3721#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
3722 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003723 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003724#endif
3725#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003726 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003727#endif
Alon Levycbcc6332011-01-19 10:49:50 +02003728#if defined(CONFIG_SPICE)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003729 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
3730 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
Alon Levycbcc6332011-01-19 10:49:50 +02003731#endif
Blue Swirlad960902010-03-29 19:23:52 +00003732 , QEMU_ARCH_ALL
Matthew Booth7273a2d2009-10-30 13:41:12 +00003733)
3734
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003735SRST
3736The general form of a character device option is:
3737
3738``-chardev backend,id=id[,mux=on|off][,options]``
3739 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``,
3740 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``,
Paolo Bonzini6f9f6302022-12-16 10:56:53 +01003741 ``pty``, ``stdio``, ``braille``, ``parallel``,
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003742 ``spicevmc``, ``spiceport``. The specific backend will determine the
3743 applicable options.
3744
3745 Use ``-chardev help`` to print all available chardev backend types.
3746
3747 All devices must have an id, which can be any string up to 127
3748 characters long. It is used to uniquely identify this device in
3749 other command line directives.
3750
3751 A character device may be used in multiplexing mode by multiple
3752 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is
3753 a "1:N" device, and here the "1" end is your specified chardev
3754 backend, and the "N" end is the various parts of QEMU that can talk
3755 to a chardev. If you create a chardev with ``id=myid`` and
3756 ``mux=on``, QEMU will create a multiplexer with your specified ID,
3757 and you can then configure multiple front ends to use that chardev
3758 ID for their input/output. Up to four different front ends can be
3759 connected to a single multiplexed chardev. (Without multiplexing
3760 enabled, a chardev can only be used by a single front end.) For
3761 instance you could use this to allow a single stdio chardev to be
3762 used by two serial ports and the QEMU monitor:
3763
3764 ::
3765
3766 -chardev stdio,mux=on,id=char0 \
3767 -mon chardev=char0,mode=readline \
3768 -serial chardev:char0 \
3769 -serial chardev:char0
3770
3771 You can have more than one multiplexer in a system configuration;
3772 for instance you could have a TCP port multiplexed between UART 0
3773 and UART 1, and stdio multiplexed between the QEMU monitor and a
3774 parallel port:
3775
3776 ::
3777
3778 -chardev stdio,mux=on,id=char0 \
3779 -mon chardev=char0,mode=readline \
3780 -parallel chardev:char0 \
3781 -chardev tcp,...,mux=on,id=char1 \
3782 -serial chardev:char1 \
3783 -serial chardev:char1
3784
3785 When you're using a multiplexed character device, some escape
Thomas Huth923e9312020-11-16 15:47:36 +01003786 sequences are interpreted in the input. See the chapter about
3787 :ref:`keys in the character backend multiplexer` in the
3788 System Emulation Users Guide for more details.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003789
3790 Note that some other command line options may implicitly create
3791 multiplexed character backends; for instance ``-serial mon:stdio``
3792 creates a multiplexed stdio backend connected to the serial port and
3793 the QEMU monitor, and ``-nographic`` also multiplexes the console
3794 and the monitor to stdio.
3795
3796 There is currently no support for multiplexing in the other
3797 direction (where a single QEMU front end takes input and output from
3798 multiple chardevs).
3799
3800 Every backend supports the ``logfile`` option, which supplies the
3801 path to a file to record all data transmitted via the backend. The
3802 ``logappend`` option controls whether the log file will be truncated
3803 or appended to when opened.
3804
3805The available backends are:
3806
3807``-chardev null,id=id``
3808 A void device. This device will not emit any data, and will drop any
3809 data it receives. The null backend does not take any options.
3810
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003811``-chardev socket,id=id[,TCP options or unix options][,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,tls-creds=id][,tls-authz=id]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003812 Create a two-way stream socket, which can be either a TCP or a unix
3813 socket. A unix socket will be created if ``path`` is specified.
3814 Behaviour is undefined if TCP options are specified for a unix
3815 socket.
3816
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003817 ``server=on|off`` specifies that the socket shall be a listening socket.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003818
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003819 ``wait=on|off`` specifies that QEMU should not block waiting for a client
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003820 to connect to a listening socket.
3821
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003822 ``telnet=on|off`` specifies that traffic on the socket should interpret
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003823 telnet escape sequences.
3824
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003825 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003826 communication.
3827
3828 ``reconnect`` sets the timeout for reconnecting on non-server
3829 sockets when the remote end goes away. qemu will delay this many
3830 seconds and then attempt to reconnect. Zero disables reconnecting,
3831 and is the default.
3832
3833 ``tls-creds`` requests enablement of the TLS protocol for
3834 encryption, and specifies the id of the TLS credentials to use for
3835 the handshake. The credentials must be previously created with the
3836 ``-object tls-creds`` argument.
3837
3838 ``tls-auth`` provides the ID of the QAuthZ authorization object
3839 against which the client's x509 distinguished name will be
3840 validated. This object is only resolved at time of use, so can be
3841 deleted and recreated on the fly while the chardev server is active.
3842 If missing, it will default to denying access.
3843
3844 TCP and unix socket options are given below:
3845
Paolo Bonzinia9b13152021-02-25 11:47:52 +01003846 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003847 ``host`` for a listening socket specifies the local address to
3848 be bound. For a connecting socket species the remote host to
3849 connect to. ``host`` is optional for listening sockets. If not
3850 specified it defaults to ``0.0.0.0``.
3851
3852 ``port`` for a listening socket specifies the local port to be
3853 bound. For a connecting socket specifies the port on the remote
3854 host to connect to. ``port`` can be given as either a port
3855 number or a service name. ``port`` is required.
3856
3857 ``to`` is only relevant to listening sockets. If it is
3858 specified, and ``port`` cannot be bound, QEMU will attempt to
3859 bind to subsequent ports up to and including ``to`` until it
3860 succeeds. ``to`` must be specified as a port number.
3861
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003862 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4
3863 or IPv6 must be used. If neither is specified the socket may
3864 use either protocol.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003865
Paolo Bonzinia9b13152021-02-25 11:47:52 +01003866 ``nodelay=on|off`` disables the Nagle algorithm.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003867
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003868 ``unix options: path=path[,abstract=on|off][,tight=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003869 ``path`` specifies the local path of the unix socket. ``path``
3870 is required.
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003871 ``abstract=on|off`` specifies the use of the abstract socket namespace,
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003872 rather than the filesystem. Optional, defaults to false.
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003873 ``tight=on|off`` sets the socket length of abstract sockets to their minimum,
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003874 rather than the full sun_path length. Optional, defaults to true.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003875
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003876``-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 +00003877 Sends all traffic from the guest to a remote host over UDP.
3878
3879 ``host`` specifies the remote host to connect to. If not specified
3880 it defaults to ``localhost``.
3881
3882 ``port`` specifies the port on the remote host to connect to.
3883 ``port`` is required.
3884
3885 ``localaddr`` specifies the local address to bind to. If not
3886 specified it defaults to ``0.0.0.0``.
3887
3888 ``localport`` specifies the local port to bind to. If not specified
3889 any available local port will be used.
3890
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003891 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003892 If neither is specified the device may use either protocol.
3893
3894``-chardev msmouse,id=id``
3895 Forward QEMU's emulated msmouse events to the guest. ``msmouse``
3896 does not take any options.
3897
3898``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]``
3899 Connect to a QEMU text console. ``vc`` may optionally be given a
3900 specific size.
3901
3902 ``width`` and ``height`` specify the width and height respectively
3903 of the console, in pixels.
3904
3905 ``cols`` and ``rows`` specify that the console be sized to fit a
3906 text console with the given dimensions.
3907
3908``-chardev ringbuf,id=id[,size=size]``
3909 Create a ring buffer with fixed size ``size``. size must be a power
3910 of two and defaults to ``64K``.
3911
Peter Maydell5b18a6b2023-04-13 16:07:24 +01003912``-chardev file,id=id,path=path[,input-path=input-path]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003913 Log all traffic received from the guest to a file.
3914
3915 ``path`` specifies the path of the file to be opened. This file will
3916 be created if it does not already exist, and overwritten if it does.
3917 ``path`` is required.
3918
Peter Maydell5b18a6b2023-04-13 16:07:24 +01003919 If ``input-path`` is specified, this is the path of a second file
3920 which will be used for input. If ``input-path`` is not specified,
3921 no input will be available from the chardev.
3922
3923 Note that ``input-path`` is not supported on Windows hosts.
3924
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003925``-chardev pipe,id=id,path=path``
3926 Create a two-way connection to the guest. The behaviour differs
3927 slightly between Windows hosts and other hosts:
3928
3929 On Windows, a single duplex pipe will be created at
3930 ``\\.pipe\path``.
3931
3932 On other hosts, 2 pipes will be created called ``path.in`` and
3933 ``path.out``. Data written to ``path.in`` will be received by the
3934 guest. Data written by the guest can be read from ``path.out``. QEMU
3935 will not create these fifos, and requires them to be present.
3936
3937 ``path`` forms part of the pipe path as described above. ``path`` is
3938 required.
3939
3940``-chardev console,id=id``
3941 Send traffic from the guest to QEMU's standard output. ``console``
3942 does not take any options.
3943
3944 ``console`` is only available on Windows hosts.
3945
3946``-chardev serial,id=id,path=path``
3947 Send traffic from the guest to a serial device on the host.
3948
3949 On Unix hosts serial will actually accept any tty device, not only
3950 serial lines.
3951
3952 ``path`` specifies the name of the serial device to open.
3953
3954``-chardev pty,id=id``
3955 Create a new pseudo-terminal on the host and connect to it. ``pty``
3956 does not take any options.
3957
3958 ``pty`` is not available on Windows hosts.
3959
3960``-chardev stdio,id=id[,signal=on|off]``
3961 Connect to standard input and standard output of the QEMU process.
3962
3963 ``signal`` controls if signals are enabled on the terminal, that
3964 includes exiting QEMU with the key sequence Control-c. This option
3965 is enabled by default, use ``signal=off`` to disable it.
3966
3967``-chardev braille,id=id``
3968 Connect to a local BrlAPI server. ``braille`` does not take any
3969 options.
3970
Peter Maydell09ce5f22020-02-28 15:36:13 +00003971``-chardev parallel,id=id,path=path``
3972 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003973 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD
3974 hosts.
3975
3976 Connect to a local parallel port.
3977
3978 ``path`` specifies the path to the parallel port device. ``path`` is
3979 required.
3980
3981``-chardev spicevmc,id=id,debug=debug,name=name``
3982 ``spicevmc`` is only available when spice support is built in.
3983
3984 ``debug`` debug level for spicevmc
3985
3986 ``name`` name of spice channel to connect to
3987
3988 Connect to a spice virtual machine channel, such as vdiport.
3989
3990``-chardev spiceport,id=id,debug=debug,name=name``
3991 ``spiceport`` is only available when spice support is built in.
3992
3993 ``debug`` debug level for spicevmc
3994
3995 ``name`` name of spice port to connect to
3996
3997 Connect to a spice port, allowing a Spice client to handle the
3998 traffic identified by a name (preferably a fqdn).
3999ERST
Matthew Booth7273a2d2009-10-30 13:41:12 +00004000
4001DEFHEADING()
4002
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05004003#ifdef CONFIG_TPM
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02004004DEFHEADING(TPM device options:)
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05004005
4006DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
Stefan Berger92dcc232013-02-27 12:47:54 -05004007 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
4008 " use path to provide path to a character device; default is /dev/tpm0\n"
4009 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
Amarnath Vallurif4ede812017-09-29 14:10:20 +03004010 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
4011 "-tpmdev emulator,id=id,chardev=dev\n"
4012 " configure the TPM device using chardev backend\n",
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05004013 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004014SRST
4015The general form of a TPM device option is:
4016
4017``-tpmdev backend,id=id[,options]``
4018 The specific backend type will determine the applicable options. The
4019 ``-tpmdev`` option creates the TPM backend and requires a
4020 ``-device`` option that specifies the TPM frontend interface model.
4021
4022 Use ``-tpmdev help`` to print all available TPM backend types.
4023
4024The available backends are:
4025
4026``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path``
4027 (Linux-host only) Enable access to the host's TPM using the
4028 passthrough driver.
4029
4030 ``path`` specifies the path to the host's TPM device, i.e., on a
4031 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by
4032 default ``/dev/tpm0`` is used.
4033
4034 ``cancel-path`` specifies the path to the host TPM device's sysfs
4035 entry allowing for cancellation of an ongoing TPM command.
4036 ``cancel-path`` is optional and by default QEMU will search for the
4037 sysfs entry to use.
4038
4039 Some notes about using the host's TPM with the passthrough driver:
4040
4041 The TPM device accessed by the passthrough driver must not be used
4042 by any other application on the host.
4043
4044 Since the host's firmware (BIOS/UEFI) has already initialized the
4045 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize
4046 the TPM again and may therefore not show a TPM-specific menu that
4047 would otherwise allow the user to configure the TPM, e.g., allow the
4048 user to enable/disable or activate/deactivate the TPM. Further, if
4049 TPM ownership is released from within a VM then the host's TPM will
4050 get disabled and deactivated. To enable and activate the TPM again
4051 afterwards, the host has to be rebooted and the user is required to
4052 enter the firmware's menu to enable and activate the TPM. If the TPM
4053 is left disabled and/or deactivated most TPM commands will fail.
4054
4055 To create a passthrough TPM use the following two options:
4056
4057 ::
4058
4059 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
4060
4061 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by
4062 ``tpmdev=tpm0`` in the device option.
4063
4064``-tpmdev emulator,id=id,chardev=dev``
4065 (Linux-host only) Enable access to a TPM emulator using Unix domain
4066 socket based chardev backend.
4067
4068 ``chardev`` specifies the unique ID of a character device backend
4069 that provides connection to the software TPM server.
4070
4071 To create a TPM emulator backend device with chardev socket backend:
4072
4073 ::
4074
4075 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
4076ERST
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05004077
4078DEFHEADING()
4079
4080#endif
4081
Alex Bennée1235cf72022-07-25 15:05:20 +01004082DEFHEADING(Boot Image or Kernel specific:)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004083SRST
Alex Bennée1235cf72022-07-25 15:05:20 +01004084There are broadly 4 ways you can boot a system with QEMU.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004085
Alex Bennée1235cf72022-07-25 15:05:20 +01004086 - specify a firmware and let it control finding a kernel
4087 - specify a firmware and pass a hint to the kernel to boot
4088 - direct kernel image boot
4089 - manually load files into the guest's address space
4090
4091The third method is useful for quickly testing kernels but as there is
4092no firmware to pass configuration information to the kernel the
4093hardware must either be probeable, the kernel built for the exact
4094configuration or passed some configuration data (e.g. a DTB blob)
4095which tells the kernel what drivers it needs. This exact details are
4096often hardware specific.
4097
4098The final method is the most generic way of loading images into the
4099guest address space and used mostly for ``bare metal`` type
4100development where the reset vectors of the processor are taken into
4101account.
4102
4103ERST
4104
4105SRST
4106
4107For x86 machines and some other architectures ``-bios`` will generally
4108do the right thing with whatever it is given. For other machines the
4109more strict ``-pflash`` option needs an image that is sized for the
4110flash device for the given machine type.
4111
4112Please see the :ref:`system-targets-ref` section of the manual for
4113more detailed documentation.
4114
4115ERST
4116
4117DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
4118 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
4119SRST
4120``-bios file``
4121 Set the filename for the BIOS.
4122ERST
4123
4124DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
4125 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
4126SRST
4127``-pflash file``
4128 Use file as a parallel flash image.
4129ERST
4130
4131SRST
4132
4133The kernel options were designed to work with Linux kernels although
4134other things (like hypervisors) can be packaged up as a kernel
4135executable image. The exact format of a executable image is usually
4136architecture specific.
4137
4138The way in which the kernel is started (what address it is loaded at,
4139what if any information is passed to it via CPU registers, the state
4140of the hardware when it is started, and so on) is also architecture
4141specific. Typically it follows the specification laid down by the
4142Linux kernel for how kernels for that architecture must be started.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004143
4144ERST
blueswir15824d652009-03-28 06:44:27 +00004145
4146DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
Blue Swirlad960902010-03-29 19:23:52 +00004147 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004148SRST
4149``-kernel bzImage``
4150 Use bzImage as kernel image. The kernel can be either a Linux kernel
4151 or in multiboot format.
4152ERST
blueswir15824d652009-03-28 06:44:27 +00004153
4154DEF("append", HAS_ARG, QEMU_OPTION_append, \
Blue Swirlad960902010-03-29 19:23:52 +00004155 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004156SRST
4157``-append cmdline``
4158 Use cmdline as kernel command line
4159ERST
blueswir15824d652009-03-28 06:44:27 +00004160
4161DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
Blue Swirlad960902010-03-29 19:23:52 +00004162 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
David Woodhouse1eeb4322024-01-30 19:01:43 +00004163SRST(initrd)
David Woodhousecc9d10b2023-10-19 15:30:23 +01004164
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004165``-initrd file``
4166 Use file as initial ram disk.
4167
4168``-initrd "file1 arg=foo,file2"``
4169 This syntax is only available with multiboot.
4170
David Woodhousecc9d10b2023-10-19 15:30:23 +01004171 Use file1 and file2 as modules and pass ``arg=foo`` as parameter to the
4172 first module. Commas can be provided in module parameters by doubling
4173 them on the command line to escape them:
4174
4175``-initrd "bzImage earlyprintk=xen,,keep root=/dev/xvda1,initrd.img"``
4176 Multiboot only. Use bzImage as the first module with
4177 "``earlyprintk=xen,keep root=/dev/xvda1``" as its command line,
4178 and initrd.img as the second module.
4179
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004180ERST
blueswir15824d652009-03-28 06:44:27 +00004181
Grant Likely412beee2012-03-02 11:56:38 +00004182DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
Peter A. G. Crosthwaite379b5c72012-03-04 21:03:54 +10004183 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004184SRST
4185``-dtb file``
4186 Use file as a device tree binary (dtb) image and pass it to the
4187 kernel on boot.
4188ERST
Grant Likely412beee2012-03-02 11:56:38 +00004189
Alex Bennée1235cf72022-07-25 15:05:20 +01004190SRST
4191
4192Finally you can also manually load images directly into the address
4193space of the guest. This is most useful for developers who already
4194know the layout of their guest and take care to ensure something sane
4195will happen when the reset vector executes.
4196
4197The generic loader can be invoked by using the loader device:
4198
4199``-device loader,addr=<addr>,data=<data>,data-len=<data-len>[,data-be=<data-be>][,cpu-num=<cpu-num>]``
4200
4201there is also the guest loader which operates in a similar way but
4202tweaks the DTB so a hypervisor loaded via ``-kernel`` can find where
4203the guest image is:
4204
4205``-device guest-loader,addr=<addr>[,kernel=<path>,[bootargs=<arguments>]][,initrd=<path>]``
4206
4207ERST
4208
blueswir15824d652009-03-28 06:44:27 +00004209DEFHEADING()
4210
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02004211DEFHEADING(Debug/Expert options:)
blueswir15824d652009-03-28 06:44:27 +00004212
Markus Armbruster6dd75472021-03-18 16:55:10 +01004213DEF("compat", HAS_ARG, QEMU_OPTION_compat,
Markus Armbrusterdbb675c2021-03-18 16:55:19 +01004214 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n"
Markus Armbruster57df0df2021-10-28 12:25:20 +02004215 " Policy for handling deprecated management interfaces\n"
4216 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n"
4217 " Policy for handling unstable management interfaces\n",
Markus Armbruster6dd75472021-03-18 16:55:10 +01004218 QEMU_ARCH_ALL)
4219SRST
4220``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]``
4221 Set policy for handling deprecated management interfaces (experimental):
4222
4223 ``deprecated-input=accept`` (default)
4224 Accept deprecated commands and arguments
4225 ``deprecated-input=reject``
4226 Reject deprecated commands and arguments
Markus Armbrusterdbb675c2021-03-18 16:55:19 +01004227 ``deprecated-input=crash``
4228 Crash on deprecated commands and arguments
Markus Armbruster6dd75472021-03-18 16:55:10 +01004229 ``deprecated-output=accept`` (default)
4230 Emit deprecated command results and events
4231 ``deprecated-output=hide``
4232 Suppress deprecated command results and events
4233
4234 Limitation: covers only syntactic aspects of QMP.
Markus Armbruster57df0df2021-10-28 12:25:20 +02004235
4236``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]``
4237 Set policy for handling unstable management interfaces (experimental):
4238
4239 ``unstable-input=accept`` (default)
4240 Accept unstable commands and arguments
4241 ``unstable-input=reject``
4242 Reject unstable commands and arguments
4243 ``unstable-input=crash``
4244 Crash on unstable commands and arguments
4245 ``unstable-output=accept`` (default)
4246 Emit unstable command results and events
4247 ``unstable-output=hide``
4248 Suppress unstable command results and events
4249
4250 Limitation: covers only syntactic aspects of QMP.
Markus Armbruster6dd75472021-03-18 16:55:10 +01004251ERST
4252
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04004253DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
4254 "-fw_cfg [name=]<name>,file=<file>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02004255 " add named fw_cfg entry with contents from file\n"
Gabriel L. Somlo6407d762015-09-29 12:29:01 -04004256 "-fw_cfg [name=]<name>,string=<str>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02004257 " add named fw_cfg entry with contents from string\n",
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04004258 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004259SRST
4260``-fw_cfg [name=]name,file=file``
4261 Add named fw\_cfg entry with contents from file file.
Yihuan Panfd49b212023-12-13 22:17:07 +08004262 If the filename contains comma, you must double it (for instance,
4263 "file=my,,file" to use file "my,file").
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004264
4265``-fw_cfg [name=]name,string=str``
4266 Add named fw\_cfg entry with contents from string str.
Yihuan Panfd49b212023-12-13 22:17:07 +08004267 If the string contains comma, you must double it (for instance,
4268 "string=my,,string" to use file "my,string").
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004269
4270 The terminating NUL character of the contents of str will not be
4271 included as part of the fw\_cfg item data. To insert contents with
4272 embedded NUL characters, you have to use the file parameter.
4273
4274 The fw\_cfg entries are passed by QEMU through to the guest.
4275
4276 Example:
4277
4278 ::
4279
4280 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
4281
4282 creates an fw\_cfg entry named opt/com.mycompany/blob with contents
4283 from ./my\_blob.bin.
4284ERST
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04004285
blueswir15824d652009-03-28 06:44:27 +00004286DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
Blue Swirlad960902010-03-29 19:23:52 +00004287 "-serial dev redirect the serial port to char device 'dev'\n",
4288 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004289SRST
4290``-serial dev``
4291 Redirect the virtual serial port to host character device dev. The
4292 default device is ``vc`` in graphical mode and ``stdio`` in non
4293 graphical mode.
4294
Steven Shen75583002024-03-05 09:30:16 +08004295 This option can be used several times to simulate multiple serial
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004296 ports.
4297
Peter Maydell747bfaf2024-01-22 16:36:07 +00004298 You can use ``-serial none`` to suppress the creation of default
4299 serial devices.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004300
4301 Available character devices are:
4302
4303 ``vc[:WxH]``
4304 Virtual console. Optionally, a width and height can be given in
4305 pixel with
4306
4307 ::
4308
4309 vc:800x600
4310
4311 It is also possible to specify width or height in characters:
4312
4313 ::
4314
4315 vc:80Cx24C
4316
4317 ``pty``
4318 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
4319
4320 ``none``
Peter Maydell747bfaf2024-01-22 16:36:07 +00004321 No device is allocated. Note that for machine types which
4322 emulate systems where a serial device is always present in
4323 real hardware, this may be equivalent to the ``null`` option,
4324 in that the serial device is still present but all output
4325 is discarded. For boards where the number of serial ports is
4326 truly variable, this suppresses the creation of the device.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004327
4328 ``null``
Peter Maydell747bfaf2024-01-22 16:36:07 +00004329 A guest will see the UART or serial device as present in the
4330 machine, but all output is discarded, and there is no input.
4331 Conceptually equivalent to redirecting the output to ``/dev/null``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004332
4333 ``chardev:id``
4334 Use a named character device defined with the ``-chardev``
4335 option.
4336
4337 ``/dev/XXX``
4338 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial
4339 port parameters are set according to the emulated ones.
4340
4341 ``/dev/parportN``
4342 [Linux only, parallel port only] Use host parallel port N.
4343 Currently SPP and EPP parallel port features can be used.
4344
4345 ``file:filename``
4346 Write output to filename. No character can be read.
4347
4348 ``stdio``
4349 [Unix only] standard input/output
4350
4351 ``pipe:filename``
4352 name pipe filename
4353
4354 ``COMn``
4355 [Windows only] Use host serial port n
4356
4357 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]``
4358 This implements UDP Net Console. When remote\_host or src\_ip
4359 are not specified they default to ``0.0.0.0``. When not using a
4360 specified src\_port a random port is automatically chosen.
4361
4362 If you just want a simple readonly console you can use
4363 ``netcat`` or ``nc``, by starting QEMU with:
4364 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time
4365 QEMU writes something to that port it will appear in the
4366 netconsole session.
4367
4368 If you plan to send characters back via netconsole or you want
4369 to stop and start QEMU a lot of times, you should have QEMU use
4370 the same source port each time by using something like ``-serial
4371 udp::4555@:4556`` to QEMU. Another approach is to use a patched
4372 version of netcat which can listen to a TCP port and send and
4373 receive characters via udp. If you have a patched version of
4374 netcat which activates telnet remote echo and single char
4375 transfer, then you can use the following options to set up a
4376 netcat redirector to allow telnet on port 5555 to access the
4377 QEMU port.
4378
4379 ``QEMU Options:``
4380 -serial udp::4555@:4556
4381
4382 ``netcat options:``
4383 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
4384
4385 ``telnet options:``
4386 localhost 5555
4387
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004388 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004389 The TCP Net Console has two modes of operation. It can send the
4390 serial I/O to a location or wait for a connection from a
4391 location. By default the TCP Net Console is sent to host at the
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004392 port. If you use the ``server=on`` option QEMU will wait for a client
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004393 socket application to connect to the port before continuing,
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004394 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004395 option disables the Nagle buffering algorithm. The ``reconnect=on``
4396 option only applies if ``server=no`` is set, if the connection goes
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004397 down it will attempt to reconnect at the given interval. If host
4398 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004399 time is accepted. You can use ``telnet=on`` to connect to the
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004400 corresponding character device.
4401
4402 ``Example to send tcp console to 192.168.0.2 port 4444``
4403 -serial tcp:192.168.0.2:4444
4404
4405 ``Example to listen and wait on port 4444 for connection``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004406 -serial tcp::4444,server=on
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004407
4408 ``Example to not wait and listen on ip 192.168.0.100 port 4444``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004409 -serial tcp:192.168.0.100:4444,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004410
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004411 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004412 The telnet protocol is used instead of raw tcp sockets. The
4413 options work the same as if you had specified ``-serial tcp``.
4414 The difference is that the port acts like a telnet server or
4415 client using telnet option negotiation. This will also allow you
4416 to send the MAGIC\_SYSRQ sequence if you use a telnet that
4417 supports sending the break sequence. Typically in unix telnet
4418 you do it with Control-] and then type "send break" followed by
4419 pressing the enter key.
4420
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004421 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004422 The WebSocket protocol is used instead of raw tcp socket. The
4423 port acts as a WebSocket server. Client mode is not supported.
4424
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004425 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004426 A unix domain socket is used instead of a tcp socket. The option
4427 works the same as if you had specified ``-serial tcp`` except
4428 the unix domain socket path is used for connections.
4429
4430 ``mon:dev_string``
4431 This is a special option to allow the monitor to be multiplexed
4432 onto another serial port. The monitor is accessed with key
4433 sequence of Control-a and then pressing c. dev\_string should be
4434 any one of the serial devices specified above. An example to
4435 multiplex the monitor onto a telnet server listening on port
4436 4444 would be:
4437
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004438 ``-serial mon:telnet::4444,server=on,wait=off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004439
4440 When the monitor is multiplexed to stdio in this way, Ctrl+C
4441 will not terminate QEMU any more but will be passed to the guest
4442 instead.
4443
4444 ``braille``
4445 Braille device. This will use BrlAPI to display the braille
4446 output on a real or fake device.
4447
4448 ``msmouse``
4449 Three button serial mouse. Configure the guest to use Microsoft
4450 protocol.
4451ERST
blueswir15824d652009-03-28 06:44:27 +00004452
4453DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
Blue Swirlad960902010-03-29 19:23:52 +00004454 "-parallel dev redirect the parallel port to char device 'dev'\n",
4455 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004456SRST
4457``-parallel dev``
4458 Redirect the virtual parallel port to host device dev (same devices
4459 as the serial port). On Linux hosts, ``/dev/parportN`` can be used
4460 to use hardware devices connected on the corresponding host parallel
4461 port.
4462
4463 This option can be used several times to simulate up to 3 parallel
4464 ports.
4465
4466 Use ``-parallel none`` to disable all parallel ports.
4467ERST
blueswir15824d652009-03-28 06:44:27 +00004468
4469DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
Blue Swirlad960902010-03-29 19:23:52 +00004470 "-monitor dev redirect the monitor to char device 'dev'\n",
4471 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004472SRST
4473``-monitor dev``
4474 Redirect the monitor to host device dev (same devices as the serial
4475 port). The default device is ``vc`` in graphical mode and ``stdio``
4476 in non graphical mode. Use ``-monitor none`` to disable the default
4477 monitor.
4478ERST
Gerd Hoffmann6ca55822009-12-08 13:11:52 +01004479DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
Blue Swirlad960902010-03-29 19:23:52 +00004480 "-qmp dev like -monitor but opens in 'control' mode\n",
4481 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004482SRST
4483``-qmp dev``
Peter Maydell0ec44682023-05-15 17:22:45 +01004484 Like ``-monitor`` but opens in 'control' mode. For example, to make
4485 QMP available on localhost port 4444::
4486
4487 -qmp tcp:localhost:4444,server=on,wait=off
4488
4489 Not all options are configurable via this syntax; for maximum
4490 flexibility use the ``-mon`` option and an accompanying ``-chardev``.
4491
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004492ERST
Max Reitz4821cd42014-11-17 13:31:04 +01004493DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
4494 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
4495 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004496SRST
4497``-qmp-pretty dev``
Peter Maydell0ec44682023-05-15 17:22:45 +01004498 Like ``-qmp`` but uses pretty JSON formatting.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004499ERST
blueswir15824d652009-03-28 06:44:27 +00004500
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01004501DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
Vicente Jimenez Aguilaref670722017-11-14 09:11:27 +01004502 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004503SRST
4504``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]``
Peter Maydell0ec44682023-05-15 17:22:45 +01004505 Set up a monitor connected to the chardev ``name``.
4506 QEMU supports two monitors: the Human Monitor Protocol
4507 (HMP; for human interaction), and the QEMU Monitor Protocol
4508 (QMP; a JSON RPC-style protocol).
4509 The default is HMP; ``mode=control`` selects QMP instead.
4510 ``pretty`` is only valid when ``mode=control``,
Ali Shirvani16b3f3b2021-05-19 11:41:45 +04304511 turning on JSON pretty printing to ease
Daniel P. Berrangé283d8452021-02-19 17:56:13 +00004512 human reading and debugging.
Peter Maydell0ec44682023-05-15 17:22:45 +01004513
4514 For example::
4515
4516 -chardev socket,id=mon1,host=localhost,port=4444,server=on,wait=off \
4517 -mon chardev=mon1,mode=control,pretty=on
4518
4519 enables the QMP monitor on localhost port 4444 with pretty-printing.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004520ERST
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01004521
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08004522DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
Blue Swirlad960902010-03-29 19:23:52 +00004523 "-debugcon dev redirect the debug console to char device 'dev'\n",
4524 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004525SRST
4526``-debugcon dev``
4527 Redirect the debug console to host device dev (same devices as the
4528 serial port). The debug console is an I/O port which is typically
4529 port 0xe9; writing to that I/O port sends output to this device. The
4530 default device is ``vc`` in graphical mode and ``stdio`` in non
4531 graphical mode.
4532ERST
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08004533
blueswir15824d652009-03-28 06:44:27 +00004534DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
Blue Swirlad960902010-03-29 19:23:52 +00004535 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004536SRST
4537``-pidfile file``
4538 Store the QEMU process PID in file. It is useful if you launch QEMU
4539 from a script.
4540ERST
blueswir15824d652009-03-28 06:44:27 +00004541
Igor Mammedov047f7032018-05-11 19:24:43 +02004542DEF("preconfig", 0, QEMU_OPTION_preconfig, \
Markus Armbruster361ac942018-07-05 11:14:02 +02004543 "--preconfig pause QEMU before machine is initialized (experimental)\n",
Igor Mammedov047f7032018-05-11 19:24:43 +02004544 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004545SRST
4546``--preconfig``
4547 Pause QEMU for interactive configuration before the machine is
4548 created, which allows querying and configuring properties that will
4549 affect machine initialization. Use QMP command 'x-exit-preconfig' to
4550 exit the preconfig state and move to the next state (i.e. run guest
4551 if -S isn't used or pause the second time if -S is used). This
4552 option is experimental.
4553ERST
Igor Mammedov047f7032018-05-11 19:24:43 +02004554
blueswir15824d652009-03-28 06:44:27 +00004555DEF("S", 0, QEMU_OPTION_S, \
Blue Swirlad960902010-03-29 19:23:52 +00004556 "-S freeze CPU at startup (use 'c' to start execution)\n",
4557 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004558SRST
4559``-S``
4560 Do not start CPU at startup (you must type 'c' in the monitor).
4561ERST
blueswir15824d652009-03-28 06:44:27 +00004562
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004563DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02004564 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n"
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004565 " run qemu with overcommit hints\n"
4566 " mem-lock=on|off controls memory lock support (default: off)\n"
4567 " cpu-pm=on|off controls cpu power management (default: off)\n",
4568 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004569SRST
4570``-overcommit mem-lock=on|off``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004571 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004572``-overcommit cpu-pm=on|off``
4573 Run qemu with hints about host resource overcommit. The default is
4574 to assume that host overcommits all resources.
4575
4576 Locking qemu and guest memory can be enabled via ``mem-lock=on``
4577 (disabled by default). This works when host memory is not
Thomas Huthc8c9dc42020-12-10 16:58:07 +01004578 overcommitted and reduces the worst-case latency for guest.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004579
4580 Guest ability to manage power state of host cpus (increasing latency
4581 for other processes on the same host cpu, but decreasing latency for
4582 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This
4583 works best when host CPU is not overcommitted. When used, host
4584 estimates of CPU cycle and power utilization will be incorrect, not
4585 taking into account guest idle time.
4586ERST
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004587
aliguori59030a82009-04-05 18:43:41 +00004588DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
Peter Maydelle5910d42020-04-03 10:40:14 +01004589 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n"
4590 " the guest without waiting for gdb to connect; use -S too\n"
4591 " if you want it to not start execution.)\n",
4592 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004593SRST
4594``-gdb dev``
Thomas Huth923e9312020-11-16 15:47:36 +01004595 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter
4596 in the System Emulation Users Guide). Note that this option does not pause QEMU
Peter Maydelle5910d42020-04-03 10:40:14 +01004597 execution -- if you want QEMU to not start the guest until you
4598 connect with gdb and issue a ``continue`` command, you will need to
4599 also pass the ``-S`` option to QEMU.
4600
4601 The most usual configuration is to listen on a local TCP socket::
4602
4603 -gdb tcp::3117
4604
4605 but you can specify other backends; UDP, pseudo TTY, or even stdio
4606 are all reasonable use cases. For example, a stdio connection
4607 allows you to start QEMU from within gdb and establish the
4608 connection via a pipe:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004609
Peter Maydell09ce5f22020-02-28 15:36:13 +00004610 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004611
4612 (gdb) target remote | exec |qemu_system| -gdb stdio ...
4613ERST
blueswir15824d652009-03-28 06:44:27 +00004614
aliguori59030a82009-04-05 18:43:41 +00004615DEF("s", 0, QEMU_OPTION_s, \
Blue Swirlad960902010-03-29 19:23:52 +00004616 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
4617 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004618SRST
4619``-s``
4620 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
Thomas Huth923e9312020-11-16 15:47:36 +01004621 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004622ERST
blueswir15824d652009-03-28 06:44:27 +00004623
4624DEF("d", HAS_ARG, QEMU_OPTION_d, \
Peter Maydell989b6972013-02-26 17:52:40 +00004625 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
Blue Swirlad960902010-03-29 19:23:52 +00004626 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004627SRST
4628``-d item1[,...]``
4629 Enable logging of specified items. Use '-d help' for a list of log
4630 items.
4631ERST
blueswir15824d652009-03-28 06:44:27 +00004632
Matthew Fernandezc235d732011-06-07 16:32:40 +00004633DEF("D", HAS_ARG, QEMU_OPTION_D, \
Peter Maydell989b6972013-02-26 17:52:40 +00004634 "-D logfile output log to logfile (default stderr)\n",
Matthew Fernandezc235d732011-06-07 16:32:40 +00004635 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004636SRST
4637``-D logfile``
4638 Output log in logfile instead of to stderr
4639ERST
Matthew Fernandezc235d732011-06-07 16:32:40 +00004640
Alex Bennée35145522016-03-15 14:30:20 +00004641DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
4642 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
4643 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004644SRST
4645``-dfilter range1[,...]``
4646 Filter debug output to that relevant to a range of target addresses.
4647 The filter spec can be either start+size, start-size or start..end
4648 where start end and size are the addresses and sizes required. For
4649 example:
4650
4651 ::
4652
4653 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
4654
4655 Will dump output for any code in the 0x1000 sized block starting at
4656 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and
4657 another 0x1000 sized block starting at 0xffffffc00005f000.
4658ERST
Alex Bennée35145522016-03-15 14:30:20 +00004659
Richard Henderson9c09a252019-03-14 13:06:29 -07004660DEF("seed", HAS_ARG, QEMU_OPTION_seed, \
4661 "-seed number seed the pseudo-random number generator\n",
4662 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004663SRST
4664``-seed number``
4665 Force the guest to use a deterministic pseudo-random number
4666 generator, seeded with number. This does not affect crypto routines
4667 within the host.
4668ERST
Richard Henderson9c09a252019-03-14 13:06:29 -07004669
blueswir15824d652009-03-28 06:44:27 +00004670DEF("L", HAS_ARG, QEMU_OPTION_L, \
Blue Swirlad960902010-03-29 19:23:52 +00004671 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
4672 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004673SRST
4674``-L path``
4675 Set the directory for the BIOS, VGA BIOS and keymaps.
4676
4677 To list all the data directories, use ``-L help``.
4678ERST
blueswir15824d652009-03-28 06:44:27 +00004679
blueswir15824d652009-03-28 06:44:27 +00004680DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
Thomas Huth21abf012022-04-27 15:49:06 +02004681 "-enable-kvm enable KVM full virtualization support\n",
4682 QEMU_ARCH_ARM | QEMU_ARCH_I386 | QEMU_ARCH_MIPS | QEMU_ARCH_PPC |
4683 QEMU_ARCH_RISCV | QEMU_ARCH_S390X)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004684SRST
4685``-enable-kvm``
4686 Enable KVM full virtualization support. This option is only
4687 available if KVM support is enabled when compiling.
4688ERST
blueswir15824d652009-03-28 06:44:27 +00004689
aliguorie37630c2009-04-22 15:19:10 +00004690DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
Thomas Hutheeb36472022-04-27 15:31:56 +02004691 "-xen-domid id specify xen guest domain id\n",
4692 QEMU_ARCH_ARM | QEMU_ARCH_I386)
aliguorie37630c2009-04-22 15:19:10 +00004693DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
4694 "-xen-attach attach to existing xen domain\n"
Anthony PERARD1077bca2018-09-14 12:18:30 +01004695 " libxl will use this when starting QEMU\n",
Thomas Hutheeb36472022-04-27 15:31:56 +02004696 QEMU_ARCH_ARM | QEMU_ARCH_I386)
Paul Durrant1c599472017-03-22 09:39:15 +00004697DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
4698 "-xen-domid-restrict restrict set of available xen operations\n"
4699 " to specified domain id. (Does not affect\n"
4700 " xenpv machine type).\n",
Thomas Hutheeb36472022-04-27 15:31:56 +02004701 QEMU_ARCH_ARM | QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004702SRST
4703``-xen-domid id``
4704 Specify xen guest domain id (XEN only).
4705
4706``-xen-attach``
4707 Attach to existing xen domain. libxl will use this when starting
4708 QEMU (XEN only). Restrict set of available xen operations to
4709 specified domain id (XEN only).
4710ERST
aliguorie37630c2009-04-22 15:19:10 +00004711
blueswir15824d652009-03-28 06:44:27 +00004712DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
Blue Swirlad960902010-03-29 19:23:52 +00004713 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004714SRST
4715``-no-reboot``
4716 Exit instead of rebooting.
4717ERST
blueswir15824d652009-03-28 06:44:27 +00004718
4719DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
Blue Swirlad960902010-03-29 19:23:52 +00004720 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004721SRST
4722``-no-shutdown``
4723 Don't exit QEMU on guest shutdown, but instead only stop the
4724 emulation. This allows for instance switching to monitor to commit
4725 changes to the disk image.
4726ERST
blueswir15824d652009-03-28 06:44:27 +00004727
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004728DEF("action", HAS_ARG, QEMU_OPTION_action,
Paolo Bonzinic27025e2021-01-20 14:30:27 +01004729 "-action reboot=reset|shutdown\n"
4730 " action when guest reboots [default=reset]\n"
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004731 "-action shutdown=poweroff|pause\n"
4732 " action when guest shuts down [default=poweroff]\n"
Ilya Leoshkevich0882caf2022-07-26 00:37:45 +02004733 "-action panic=pause|shutdown|exit-failure|none\n"
Paolo Bonzinic27025e2021-01-20 14:30:27 +01004734 " action when guest panics [default=shutdown]\n"
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004735 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n"
4736 " action when watchdog fires [default=reset]\n",
4737 QEMU_ARCH_ALL)
4738SRST
4739``-action event=action``
4740 The action parameter serves to modify QEMU's default behavior when
4741 certain guest events occur. It provides a generic method for specifying the
4742 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown``
4743 parameters.
4744
4745 Examples:
4746
Alejandro Jimenezc753e8e2020-12-11 17:31:52 -05004747 ``-action panic=none``
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004748 ``-action reboot=shutdown,shutdown=pause``
Paolo Bonzini5433af72022-09-10 13:44:47 +02004749 ``-device i6300esb -action watchdog=pause``
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004750
4751ERST
4752
blueswir15824d652009-03-28 06:44:27 +00004753DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
4754 "-loadvm [tag|id]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004755 " start right away with a saved state (loadvm in monitor)\n",
4756 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004757SRST
4758``-loadvm file``
4759 Start right away with a saved state (``loadvm`` in monitor)
4760ERST
blueswir15824d652009-03-28 06:44:27 +00004761
4762#ifndef _WIN32
4763DEF("daemonize", 0, QEMU_OPTION_daemonize, \
Blue Swirlad960902010-03-29 19:23:52 +00004764 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004765#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004766SRST
4767``-daemonize``
4768 Daemonize the QEMU process after initialization. QEMU will not
4769 detach from standard IO until it is ready to receive connections on
4770 any of its devices. This option is a useful way for external
4771 programs to launch QEMU without having to cope with initialization
4772 race conditions.
4773ERST
blueswir15824d652009-03-28 06:44:27 +00004774
4775DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
Blue Swirlad960902010-03-29 19:23:52 +00004776 "-option-rom rom load a file, rom, into the option ROM space\n",
4777 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004778SRST
4779``-option-rom file``
4780 Load the contents of file as an option ROM. This option is useful to
4781 load things like EtherBoot.
4782ERST
blueswir15824d652009-03-28 06:44:27 +00004783
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02004784DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
Artem Pisarenko238d1242018-10-18 13:12:52 +06004785 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004786 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
4787 QEMU_ARCH_ALL)
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02004788
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004789SRST
4790``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]``
4791 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at
4792 the current UTC or local time, respectively. ``localtime`` is
4793 required for correct date in MS-DOS or Windows. To start at a
4794 specific point in time, provide datetime in the format
4795 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC.
4796
4797 By default the RTC is driven by the host system time. This allows
4798 using of the RTC as accurate reference clock inside the guest,
4799 specifically if the host time is smoothly following an accurate
4800 external reference clock, e.g. via NTP. If you want to isolate the
4801 guest time from the host, you can set ``clock`` to ``rt`` instead,
4802 which provides a host monotonic clock if host support it. To even
4803 prevent the RTC from progressing during suspension, you can set
4804 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is
4805 recommended especially in icount mode in order to preserve
4806 determinism; however, note that in icount mode the speed of the
4807 virtual clock is variable and can in general differ from the host
4808 clock.
4809
4810 Enable ``driftfix`` (i386 targets only) if you experience time drift
4811 problems, specifically with Windows' ACPI HAL. This option will try
4812 to figure out how many timer interrupts were not processed by the
4813 Windows guest and will re-inject them.
4814ERST
blueswir15824d652009-03-28 06:44:27 +00004815
4816DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
Peter Maydellfa647902020-11-21 21:35:06 +00004817 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \
aliguoribc14ca22009-04-05 18:43:37 +00004818 " enable virtual instruction counter with 2^N clock ticks per\n" \
Victor CLEMENTf1f4b572015-05-29 17:14:05 +02004819 " instruction, enable aligning the host and virtual clocks\n" \
Peter Maydellfa647902020-11-21 21:35:06 +00004820 " or disable real time cpu sleeping, and optionally enable\n" \
4821 " record-and-replay mode\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004822SRST
Peter Maydellfa647902020-11-21 21:35:06 +00004823``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004824 Enable virtual instruction counter. The virtual cpu will execute one
4825 instruction every 2^N ns of virtual time. If ``auto`` is specified
4826 then the virtual cpu speed will be automatically adjusted to keep
4827 virtual time within a few seconds of real time.
4828
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004829 Note that while this option can give deterministic behavior, it does
4830 not provide cycle accurate emulation. Modern CPUs contain
4831 superscalar out of order cores with complex cache hierarchies. The
4832 number of instructions executed often has little or no correlation
4833 with actual performance.
4834
Peter Maydellfa647902020-11-21 21:35:06 +00004835 When the virtual cpu is sleeping, the virtual time will advance at
4836 default speed unless ``sleep=on`` is specified. With
4837 ``sleep=on``, the virtual time will jump to the next timer
4838 deadline instantly whenever the virtual cpu goes to sleep mode and
4839 will not advance if no timer is enabled. This behavior gives
4840 deterministic execution times from the guest point of view.
4841 The default if icount is enabled is ``sleep=off``.
4842 ``sleep=on`` cannot be used together with either ``shift=auto``
4843 or ``align=on``.
4844
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004845 ``align=on`` will activate the delay algorithm which will try to
4846 synchronise the host clock and the virtual clock. The goal is to
4847 have a guest running at the real frequency imposed by the shift
4848 option. Whenever the guest clock is behind the host clock and if
4849 ``align=on`` is specified then we print a message to the user to
4850 inform about the delay. Currently this option does not work when
4851 ``shift`` is ``auto``. Note: The sync algorithm will work for those
4852 shift values for which the guest clock runs ahead of the host clock.
4853 Typically this happens when the shift value is high (how high
Peter Maydellfa647902020-11-21 21:35:06 +00004854 depends on the host machine). The default if icount is enabled
4855 is ``align=off``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004856
Peter Maydellfa647902020-11-21 21:35:06 +00004857 When the ``rr`` option is specified deterministic record/replay is
4858 enabled. The ``rrfile=`` option must also be provided to
4859 specify the path to the replay log. In record mode data is written
4860 to this file, and in replay mode it is read back.
4861 If the ``rrsnapshot`` option is given then it specifies a VM snapshot
4862 name. In record mode, a new VM snapshot with the given name is created
4863 at the start of execution recording. In replay mode this option
4864 specifies the snapshot name used to load the initial VM state.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004865ERST
blueswir15824d652009-03-28 06:44:27 +00004866
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004867DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
Markus Armbruster7ad92702017-10-02 16:03:07 +02004868 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004869 " action when watchdog fires [default=reset]\n",
4870 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004871SRST
4872``-watchdog-action action``
4873 The action controls what QEMU will do when the watchdog timer
4874 expires. The default is ``reset`` (forcefully reset the guest).
4875 Other possible actions are: ``shutdown`` (attempt to gracefully
4876 shutdown the guest), ``poweroff`` (forcefully poweroff the guest),
4877 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the
4878 guest), ``debug`` (print a debug message and continue), or ``none``
4879 (do nothing).
4880
4881 Note that the ``shutdown`` action requires that the guest responds
4882 to ACPI signals, which it may not be able to do in the sort of
4883 situations where the watchdog would have expired, and thus
4884 ``-watchdog-action shutdown`` is not recommended for production use.
4885
4886 Examples:
4887
Paolo Bonzini5433af72022-09-10 13:44:47 +02004888 ``-device i6300esb -watchdog-action pause``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004889
4890ERST
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004891
blueswir15824d652009-03-28 06:44:27 +00004892DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
Blue Swirlad960902010-03-29 19:23:52 +00004893 "-echr chr set terminal escape character instead of ctrl-a\n",
4894 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004895SRST
4896``-echr numeric_ascii_value``
4897 Change the escape character used for switching to the monitor when
4898 using monitor and serial sharing. The default is ``0x01`` when using
4899 the ``-nographic`` option. ``0x01`` is equal to pressing
4900 ``Control-a``. You can select a different character from the ascii
4901 control keys where 1 through 26 map to Control-a through Control-z.
4902 For instance you could use the either of the following to change the
4903 escape character to Control-t.
4904
4905 ``-echr 0x14``; \ ``-echr 20``
4906
4907ERST
blueswir15824d652009-03-28 06:44:27 +00004908
blueswir15824d652009-03-28 06:44:27 +00004909DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004910 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \
4911 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \
Michael Tokarev7c601802015-02-10 22:40:47 +03004912 "-incoming unix:socketpath\n" \
4913 " prepare for incoming migration, listen on\n" \
4914 " specified protocol and socket address\n" \
4915 "-incoming fd:fd\n" \
Steve Sistare385f5102023-09-08 07:22:11 -07004916 "-incoming file:filename[,offset=offset]\n" \
Michael Tokarev7c601802015-02-10 22:40:47 +03004917 "-incoming exec:cmdline\n" \
4918 " accept incoming migration on given file descriptor\n" \
Dr. David Alan Gilbert15970512015-05-29 19:52:52 +01004919 " or from given external command\n" \
4920 "-incoming defer\n" \
4921 " wait for the URI to be specified via migrate_incoming\n",
Blue Swirlad960902010-03-29 19:23:52 +00004922 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004923SRST
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004924``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004925 \
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004926``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004927 Prepare for incoming migration, listen on a given tcp port.
4928
4929``-incoming unix:socketpath``
4930 Prepare for incoming migration, listen on a given unix socket.
4931
4932``-incoming fd:fd``
Steve Sistare2a9e2e52023-09-08 07:22:10 -07004933 Accept incoming migration from a given file descriptor.
4934
Steve Sistare385f5102023-09-08 07:22:11 -07004935``-incoming file:filename[,offset=offset]``
4936 Accept incoming migration from a given file starting at offset.
4937 offset allows the common size suffixes, or a 0x prefix, but not both.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004938
4939``-incoming exec:cmdline``
4940 Accept incoming migration as an output from specified external
4941 command.
4942
4943``-incoming defer``
4944 Wait for the URI to be specified via migrate\_incoming. The monitor
4945 can be used to change settings (such as migration parameters) prior
4946 to issuing the migrate\_incoming to allow the migration to begin.
4947ERST
blueswir15824d652009-03-28 06:44:27 +00004948
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304949DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
4950 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004951SRST
4952``-only-migratable``
4953 Only allow migratable devices. Devices will not be allowed to enter
4954 an unmigratable state.
4955ERST
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304956
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004957DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
Blue Swirlad960902010-03-29 19:23:52 +00004958 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004959SRST
4960``-nodefaults``
4961 Don't create default devices. Normally, QEMU sets the default
4962 devices like serial port, parallel port, virtual console, monitor
4963 device, VGA adapter, floppy and CD-ROM drive and others. The
4964 ``-nodefaults`` option will disable all those default devices.
4965ERST
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004966
blueswir15824d652009-03-28 06:44:27 +00004967#ifndef _WIN32
blueswir15824d652009-03-28 06:44:27 +00004968DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
Ian Jackson2c42f1e2017-09-15 18:10:44 +01004969 "-runas user change to user id user just before starting the VM\n" \
4970 " user can be numeric uid:gid instead\n",
Blue Swirlad960902010-03-29 19:23:52 +00004971 QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004972#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004973SRST
4974``-runas user``
4975 Immediately before starting guest execution, drop root privileges,
Thomas Huth95e0fb02024-05-06 13:20:58 +02004976 switching to the specified user. This option is deprecated, use
4977 ``-run-with user=...`` instead.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004978ERST
blueswir15824d652009-03-28 06:44:27 +00004979
blueswir15824d652009-03-28 06:44:27 +00004980DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
4981 "-prom-env variable=value\n"
Blue Swirlad960902010-03-29 19:23:52 +00004982 " set OpenBIOS nvram variables\n",
4983 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004984SRST
4985``-prom-env variable=value``
4986 Set OpenBIOS nvram variable to given value (PPC, SPARC only).
4987
4988 ::
4989
4990 qemu-system-sparc -prom-env 'auto-boot?=false' \
4991 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
4992
4993 ::
4994
4995 qemu-system-ppc -prom-env 'auto-boot?=false' \
4996 -prom-env 'boot-device=hd:2,\yaboot' \
4997 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
4998ERST
blueswir15824d652009-03-28 06:44:27 +00004999DEF("semihosting", 0, QEMU_OPTION_semihosting,
Michael Wallef7bbcfb2014-04-22 20:18:42 +02005000 "-semihosting semihosting mode\n",
Markus Armbruster9d49bcf2021-05-03 10:40:33 +02005001 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA |
Philippe Mathieu-Daudé6c301482024-03-27 12:10:58 +01005002 QEMU_ARCH_MIPS | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005003SRST
5004``-semihosting``
Philippe Mathieu-Daudé6c301482024-03-27 12:10:58 +01005005 Enable :ref:`Semihosting` mode (ARM, M68K, Xtensa, MIPS, RISC-V only).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005006
Alex Bennée2da9d212023-01-24 18:01:13 +00005007 .. warning::
5008 Note that this allows guest direct access to the host filesystem, so
5009 should only be used with a trusted guest OS.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005010
5011 See the -semihosting-config option documentation for further
5012 information about the facilities this enables.
5013ERST
Liviu Ionescua38bb072014-12-11 12:07:48 +00005014DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
Peter Maydell52028612022-08-22 15:12:24 +01005015 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]\n" \
Leon Alraea59d31a2015-06-19 14:17:45 +01005016 " semihosting configuration\n",
Markus Armbruster9d49bcf2021-05-03 10:40:33 +02005017QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA |
Philippe Mathieu-Daudé6c301482024-03-27 12:10:58 +01005018QEMU_ARCH_MIPS | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005019SRST
Peter Maydell52028612022-08-22 15:12:24 +01005020``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]``
Philippe Mathieu-Daudé6c301482024-03-27 12:10:58 +01005021 Enable and configure :ref:`Semihosting` (ARM, M68K, Xtensa, MIPS, RISC-V
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005022 only).
5023
Alex Bennée2da9d212023-01-24 18:01:13 +00005024 .. warning::
5025 Note that this allows guest direct access to the host filesystem, so
5026 should only be used with a trusted guest OS.
Keith Packarda10b9d92021-01-08 22:42:52 +00005027
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005028 ``target=native|gdb|auto``
5029 Defines where the semihosting calls will be addressed, to QEMU
5030 (``native``) or to GDB (``gdb``). The default is ``auto``, which
5031 means ``gdb`` during debug sessions and ``native`` otherwise.
5032
5033 ``chardev=str1``
5034 Send the output to a chardev backend output for native or auto
5035 output when not in gdb
5036
Peter Maydell52028612022-08-22 15:12:24 +01005037 ``userspace=on|off``
5038 Allows code running in guest userspace to access the semihosting
5039 interface. The default is that only privileged guest code can
5040 make semihosting calls. Note that setting ``userspace=on`` should
5041 only be used if all guest code is trusted (for example, in
5042 bare-metal test case code).
5043
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005044 ``arg=str1,arg=str2,...``
5045 Allows the user to pass input arguments, and can be used
5046 multiple times to build up a list. The old-style
5047 ``-kernel``/``-append`` method of passing a command line is
5048 still supported for backward compatibility. If both the
5049 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are
5050 specified, the former is passed to semihosting as it always
5051 takes precedence.
5052ERST
blueswir15824d652009-03-28 06:44:27 +00005053DEF("old-param", 0, QEMU_OPTION_old_param,
Blue Swirlad960902010-03-29 19:23:52 +00005054 "-old-param old param mode\n", QEMU_ARCH_ARM)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005055SRST
5056``-old-param``
5057 Old param mode (ARM only).
5058ERST
Stefan Weil95d5f082010-01-20 22:25:27 +01005059
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03005060DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01005061 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01005062 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
Eduardo Otubo2b716fa2017-03-01 23:17:29 +01005063 " Enable seccomp mode 2 system call filter (default 'off').\n" \
5064 " use 'obsolete' to allow obsolete system calls that are provided\n" \
5065 " by the kernel, but typically no longer used by modern\n" \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01005066 " C library implementations.\n" \
Philippe Mathieu-Daudéd42304b2021-03-03 19:46:43 +01005067 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \
5068 " to elevate privileges using set*uid|gid system calls.\n" \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01005069 " The value 'children' will deny set*uid|gid system calls for\n" \
Eduardo Otubo995a2262017-03-13 22:16:01 +01005070 " main QEMU process but will allow forks and execves to run unprivileged\n" \
5071 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
Philippe Mathieu-Daudéd42304b2021-03-03 19:46:43 +01005072 " blocking *fork and execve\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01005073 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03005074 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005075SRST
5076``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]``
5077 Enable Seccomp mode 2 system call filter. 'on' will enable syscall
5078 filtering and 'off' will disable it. The default is 'off'.
5079
5080 ``obsolete=string``
5081 Enable Obsolete system calls
5082
5083 ``elevateprivileges=string``
5084 Disable set\*uid\|gid system calls
5085
5086 ``spawn=string``
5087 Disable \*fork and execve
5088
5089 ``resourcecontrol=string``
5090 Disable process affinity and schedular priority
5091ERST
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03005092
Gerd Hoffmann715a6642009-10-14 10:39:28 +02005093DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
Paolo Bonzinie960a7e2022-04-14 10:57:21 -04005094 "-readconfig <file>\n"
5095 " read config file\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005096SRST
5097``-readconfig file``
5098 Read device configuration from file. This approach is useful when
5099 you want to spawn QEMU process with many command line options but
5100 you don't want to exceed the command line character limit.
5101ERST
Thomas Huth2feac452018-08-21 12:59:56 +02005102
Eduardo Habkostf29a5612012-05-02 13:07:29 -03005103DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
5104 "-no-user-config\n"
Eduardo Habkost3478eae2017-10-04 00:00:25 -03005105 " do not load default user-provided config files at startup\n",
Eduardo Habkostf29a5612012-05-02 13:07:29 -03005106 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005107SRST
5108``-no-user-config``
5109 The ``-no-user-config`` option makes QEMU not load any of the
5110 user-provided config files on sysconfdir.
5111ERST
Thomas Huth2feac452018-08-21 12:59:56 +02005112
Prerna Saxenaab6540d2010-08-09 11:48:32 +01005113DEF("trace", HAS_ARG, QEMU_OPTION_trace,
Paolo Bonzini10578a22016-01-07 16:55:26 +03005114 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
Lluís23d15e82011-08-31 20:31:31 +02005115 " specify tracing options\n",
Prerna Saxenaab6540d2010-08-09 11:48:32 +01005116 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005117SRST
5118``-trace [[enable=]pattern][,events=file][,file=file]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00005119 .. include:: ../qemu-option-trace.rst.inc
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005120
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005121ERST
Lluís Vilanova42229a72017-07-24 17:28:22 +03005122DEF("plugin", HAS_ARG, QEMU_OPTION_plugin,
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02005123 "-plugin [file=]<file>[,<argname>=<argvalue>]\n"
Lluís Vilanova42229a72017-07-24 17:28:22 +03005124 " load a plugin\n",
5125 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005126SRST
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02005127``-plugin file=file[,argname=argvalue]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005128 Load a plugin.
5129
5130 ``file=file``
5131 Load the given plugin from a shared library file.
5132
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02005133 ``argname=argvalue``
5134 Argument passed to the plugin. (Can be given multiple times.)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005135ERST
Stefan Weil3dbf2c72010-01-16 18:19:44 +01005136
Markus Armbruster31e70d62013-02-13 19:49:37 +01005137HXCOMM Internal use
5138DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
5139DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
Anthony Liguoric7f0f3b2012-03-28 15:42:02 +02005140
Thomas Huth9ffcbe22023-07-03 09:44:47 +02005141#ifdef CONFIG_POSIX
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02005142DEF("run-with", HAS_ARG, QEMU_OPTION_run_with,
Thomas Huth95e0fb02024-05-06 13:20:58 +02005143 "-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]\n"
Thomas Huth9ffcbe22023-07-03 09:44:47 +02005144 " Set miscellaneous QEMU process lifecycle options:\n"
5145 " async-teardown=on enables asynchronous teardown (Linux only)\n"
Thomas Huth95e0fb02024-05-06 13:20:58 +02005146 " chroot=dir chroot to dir just before starting the VM\n"
5147 " user=username switch to the specified user before starting the VM\n"
5148 " user=uid:gid ditto, but use specified user-ID and group-ID instead\n",
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02005149 QEMU_ARCH_ALL)
5150SRST
Thomas Huth95e0fb02024-05-06 13:20:58 +02005151``-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]``
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02005152 Set QEMU process lifecycle options.
5153
5154 ``async-teardown=on`` enables asynchronous teardown. A new process called
5155 "cleanup/<QEMU_PID>" will be created at startup sharing the address
5156 space with the main QEMU process, using clone. It will wait for the
5157 main QEMU process to terminate completely, and then exit. This allows
5158 QEMU to terminate very quickly even if the guest was huge, leaving the
5159 teardown of the address space to the cleanup process. Since the cleanup
5160 process shares the same cgroups as the main QEMU process, accounting is
5161 performed correctly. This only works if the cleanup process is not
5162 forcefully killed with SIGKILL before the main QEMU process has
5163 terminated completely.
Thomas Huth9ffcbe22023-07-03 09:44:47 +02005164
5165 ``chroot=dir`` can be used for doing a chroot to the specified directory
5166 immediately before starting the guest execution. This is especially useful
5167 in combination with -runas.
Thomas Huth95e0fb02024-05-06 13:20:58 +02005168
5169 ``user=username`` or ``user=uid:gid`` can be used to drop root privileges
Boqiao Fude12ebf2024-07-15 17:04:32 +08005170 before starting guest execution. QEMU will use the ``setuid`` and ``setgid``
5171 system calls to switch to the specified identity. Note that the
5172 ``user=username`` syntax will also apply the full set of supplementary
5173 groups for the user, whereas the ``user=uid:gid`` will use only the
5174 ``gid`` group.
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02005175ERST
5176#endif
Claudio Imbrendac891c242022-08-12 15:34:53 +02005177
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04005178DEF("msg", HAS_ARG, QEMU_OPTION_msg,
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005179 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n"
Markus Armbrusterdeda4972019-10-10 10:15:08 +02005180 " control error message format\n"
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005181 " timestamp=on enables timestamps (default: off)\n"
5182 " guest-name=on enables guest name prefix but only if\n"
5183 " -name guest option is set (default: off)\n",
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04005184 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005185SRST
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005186``-msg [timestamp[=on|off]][,guest-name[=on|off]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005187 Control error message format.
5188
5189 ``timestamp=on|off``
5190 Prefix messages with a timestamp. Default is off.
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005191
5192 ``guest-name=on|off``
5193 Prefix messages with guest name but only if -name guest option is set
5194 otherwise the option is ignored. Default is off.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005195ERST
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04005196
Amit Shahabfd9ce2014-06-20 18:56:08 +05305197DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
5198 "-dump-vmstate <file>\n"
5199 " Output vmstate information in JSON format to file.\n"
5200 " Use the scripts/vmstate-static-checker.py file to\n"
5201 " check for possible regressions in migration code\n"
Laurent Vivier23820532015-09-04 21:30:04 +02005202 " by comparing two such vmstate dumps.\n",
Amit Shahabfd9ce2014-06-20 18:56:08 +05305203 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005204SRST
5205``-dump-vmstate file``
5206 Dump json-encoded vmstate information for current machine type to
5207 file in file
5208ERST
Amit Shahabfd9ce2014-06-20 18:56:08 +05305209
Emilio G. Cota12df1892018-08-15 11:42:49 -04005210DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
5211 "-enable-sync-profile\n"
5212 " enable synchronization profiling\n",
5213 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005214SRST
5215``-enable-sync-profile``
5216 Enable synchronization profiling.
5217ERST
Emilio G. Cota12df1892018-08-15 11:42:49 -04005218
Ilya Leoshkevich5584e2d2023-01-12 16:20:13 +01005219#if defined(CONFIG_TCG) && defined(CONFIG_LINUX)
5220DEF("perfmap", 0, QEMU_OPTION_perfmap,
5221 "-perfmap generate a /tmp/perf-${pid}.map file for perf\n",
5222 QEMU_ARCH_ALL)
5223SRST
5224``-perfmap``
5225 Generate a map file for Linux perf tools that will allow basic profiling
5226 information to be broken down into basic blocks.
5227ERST
5228
5229DEF("jitdump", 0, QEMU_OPTION_jitdump,
5230 "-jitdump generate a jit-${pid}.dump file for perf\n",
5231 QEMU_ARCH_ALL)
5232SRST
5233``-jitdump``
5234 Generate a dump file for Linux perf tools that maps basic blocks to symbol
5235 names, line numbers and JITted code.
5236ERST
5237#endif
5238
Paolo Bonzini43f187a2017-01-04 13:50:37 +01005239DEFHEADING()
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02005240
5241DEFHEADING(Generic object creation:)
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01005242
5243DEF("object", HAS_ARG, QEMU_OPTION_object,
5244 "-object TYPENAME[,PROP1=VALUE1,...]\n"
5245 " create a new object of type TYPENAME setting properties\n"
5246 " in the order they are specified. Note that the 'id'\n"
5247 " property must be set. These objects are placed in the\n"
5248 " '/objects' path.\n",
5249 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005250SRST
5251``-object typename[,prop1=value1,...]``
5252 Create a new object of type typename setting properties in the order
5253 they are specified. Note that the 'id' property must be set. These
5254 objects are placed in the '/objects' path.
5255
David Hildenbrande92666b2023-09-06 14:04:55 +02005256 ``-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 +00005257 Creates a memory file backend object, which can be used to back
5258 the guest RAM with huge pages.
5259
5260 The ``id`` parameter is a unique ID that will be used to
Robert Hoo56c9f002021-04-22 16:42:02 +08005261 reference this memory region in other parameters, e.g. ``-numa``,
5262 ``-device nvdimm``, etc.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005263
5264 The ``size`` option provides the size of the memory region, and
Robert Hoo56c9f002021-04-22 16:42:02 +08005265 accepts common suffixes, e.g. ``500M``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005266
5267 The ``mem-path`` provides the path to either a shared memory or
5268 huge page filesystem mount.
5269
5270 The ``share`` boolean option determines whether the memory
5271 region is marked as private to QEMU, or shared. The latter
5272 allows a co-operating external process to access the QEMU memory
5273 region.
5274
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005275 Setting share=on might affect the ability to configure NUMA
5276 bindings for the memory backend under some circumstances, see
5277 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel
5278 source tree for additional details.
5279
5280 Setting the ``discard-data`` boolean option to on indicates that
5281 file contents can be destroyed when QEMU exits, to avoid
5282 unnecessarily flushing data to the backing file. Note that
5283 ``discard-data`` is only an optimization, and QEMU might not
5284 discard file contents if it aborts unexpectedly or is terminated
5285 using SIGKILL.
5286
5287 The ``merge`` boolean option enables memory merge, also known as
5288 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider
5289 the pages for memory deduplication.
5290
5291 Setting the ``dump`` boolean option to off excludes the memory
5292 from core dumps. This feature is also known as MADV\_DONTDUMP.
5293
5294 The ``prealloc`` boolean option enables memory preallocation.
5295
5296 The ``host-nodes`` option binds the memory range to a list of
5297 NUMA host nodes.
5298
5299 The ``policy`` option sets the NUMA policy to one of the
5300 following values:
5301
5302 ``default``
5303 default host policy
5304
5305 ``preferred``
5306 prefer the given host node list for allocation
5307
5308 ``bind``
5309 restrict memory allocation to the given host node list
5310
5311 ``interleave``
5312 interleave memory allocations across the given host node
5313 list
5314
5315 The ``align`` option specifies the base address alignment when
5316 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg
5317 ``2M``. Some backend store specified by ``mem-path`` requires an
5318 alignment different than the default one used by QEMU, eg the
5319 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
5320 such cases, users can specify the required alignment via this
5321 option.
5322
Alexander Graf4b870dc2023-04-03 22:14:21 +00005323 The ``offset`` option specifies the offset into the target file
5324 that the region starts at. You can use this parameter to back
5325 multiple regions with a single file.
5326
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005327 The ``pmem`` option specifies whether the backing file specified
5328 by ``mem-path`` is in host persistent memory that can be
5329 accessed using the SNIA NVM programming model (e.g. Intel
5330 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary
5331 operations to guarantee the persistence of its own writes to
5332 ``mem-path`` (e.g. in vNVDIMM label emulation and live
5333 migration). Also, we will map the backend-file with MAP\_SYNC
5334 flag, which ensures the file metadata is in sync for
5335 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC
5336 requires support from both the host kernel (since Linux kernel
5337 4.15) and the filesystem of ``mem-path`` mounted with DAX
5338 option.
5339
Stefan Hajnoczi86635aa2021-01-04 17:13:19 +00005340 The ``readonly`` option specifies whether the backing file is opened
5341 read-only or read-write (default).
5342
David Hildenbrande92666b2023-09-06 14:04:55 +02005343 The ``rom`` option specifies whether to create Read Only Memory
5344 (ROM) that cannot be modified by the VM. Any write attempts to such
5345 ROM will be denied. Most use cases want proper RAM instead of ROM.
5346 However, selected use cases, like R/O NVDIMMs, can benefit from
5347 ROM. If set to ``on``, create ROM; if set to ``off``, create
5348 writable RAM; if set to ``auto`` (default), the value of the
5349 ``readonly`` option is used. This option is primarily helpful when
5350 we want to have writable RAM in configurations that would
5351 traditionally create ROM before the ``rom`` option was introduced:
5352 VM templating, where we want to open a file readonly
5353 (``readonly=on``) and mark the memory to be private for QEMU
5354 (``share=off``). For this use case, we need writable RAM instead
5355 of ROM, and want to also set ``rom=off``.
5356
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005357 ``-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``
5358 Creates a memory backend object, which can be used to back the
5359 guest RAM. Memory backend objects offer more control than the
5360 ``-m`` option that is traditionally used to define guest RAM.
5361 Please refer to ``memory-backend-file`` for a description of the
5362 options.
5363
5364 ``-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``
5365 Creates an anonymous memory file backend object, which allows
5366 QEMU to share the memory with an external process (e.g. when
5367 using vhost-user). The memory is allocated with memfd and
5368 optional sealing. (Linux only)
5369
5370 The ``seal`` option creates a sealed-file, that will block
5371 further resizing the memory ('on' by default).
5372
5373 The ``hugetlb`` option specify the file to be created resides in
5374 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction
5375 with the ``hugetlb`` option, the ``hugetlbsize`` option specify
5376 the hugetlb page size on systems that support multiple hugetlb
5377 page sizes (it must be a power of 2 value supported by the
5378 system).
5379
5380 In some versions of Linux, the ``hugetlb`` option is
5381 incompatible with the ``seal`` option (requires at least Linux
5382 4.16).
5383
5384 Please refer to ``memory-backend-file`` for a description of the
5385 other options.
5386
5387 The ``share`` boolean option is on by default with memfd.
5388
Stefano Garzarella4e647fa2024-06-18 12:05:19 +02005389 ``-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``
5390 Creates a POSIX shared memory backend object, which allows
5391 QEMU to share the memory with an external process (e.g. when
5392 using vhost-user).
5393
5394 ``memory-backend-shm`` is a more portable and less featureful version
5395 of ``memory-backend-memfd``. It can then be used in any POSIX system,
5396 especially when memfd is not supported.
5397
5398 Please refer to ``memory-backend-file`` for a description of the
5399 options.
5400
5401 The ``share`` boolean option is on by default with shm. Setting it to
5402 off will cause a failure during allocation because it is not supported
5403 by this backend.
5404
Eric Auger6e6d8ac2023-11-21 16:44:00 +08005405 ``-object iommufd,id=id[,fd=fd]``
5406 Creates an iommufd backend which allows control of DMA mapping
5407 through the ``/dev/iommu`` device.
5408
5409 The ``id`` parameter is a unique ID which frontends (such as
5410 vfio-pci of vdpa) will use to connect with the iommufd backend.
5411
5412 The ``fd`` parameter is an optional pre-opened file descriptor
5413 resulting from ``/dev/iommu`` opening. Usually the iommufd is shared
5414 across all subsystems, bringing the benefit of centralized
5415 reference counting.
5416
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005417 ``-object rng-builtin,id=id``
5418 Creates a random number generator backend which obtains entropy
5419 from QEMU builtin functions. The ``id`` parameter is a unique ID
5420 that will be used to reference this entropy backend from the
5421 ``virtio-rng`` device. By default, the ``virtio-rng`` device
5422 uses this RNG backend.
5423
5424 ``-object rng-random,id=id,filename=/dev/random``
5425 Creates a random number generator backend which obtains entropy
5426 from a device on the host. The ``id`` parameter is a unique ID
5427 that will be used to reference this entropy backend from the
5428 ``virtio-rng`` device. The ``filename`` parameter specifies
5429 which file to obtain entropy from and if omitted defaults to
5430 ``/dev/urandom``.
5431
5432 ``-object rng-egd,id=id,chardev=chardevid``
5433 Creates a random number generator backend which obtains entropy
5434 from an external daemon running on the host. The ``id``
5435 parameter is a unique ID that will be used to reference this
5436 entropy backend from the ``virtio-rng`` device. The ``chardev``
5437 parameter is the unique ID of a character device backend that
5438 provides the connection to the RNG daemon.
5439
5440 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off``
5441 Creates a TLS anonymous credentials object, which can be used to
5442 provide TLS support on network backends. The ``id`` parameter is
5443 a unique ID which network backends will use to access the
5444 credentials. The ``endpoint`` is either ``server`` or ``client``
5445 depending on whether the QEMU network backend that uses the
5446 credentials will be acting as a client or as a server. If
5447 ``verify-peer`` is enabled (the default) then once the handshake
5448 is completed, the peer credentials will be verified, though this
5449 is a no-op for anonymous credentials.
5450
5451 The dir parameter tells QEMU where to find the credential files.
5452 For server endpoints, this directory may contain a file
5453 dh-params.pem providing diffie-hellman parameters to use for the
5454 TLS server. If the file is missing, QEMU will generate a set of
5455 DH parameters at startup. This is a computationally expensive
5456 operation that consumes random pool entropy, so it is
5457 recommended that a persistent set of parameters be generated
5458 upfront and saved.
5459
5460 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]``
5461 Creates a TLS Pre-Shared Keys (PSK) credentials object, which
5462 can be used to provide TLS support on network backends. The
5463 ``id`` parameter is a unique ID which network backends will use
5464 to access the credentials. The ``endpoint`` is either ``server``
5465 or ``client`` depending on whether the QEMU network backend that
5466 uses the credentials will be acting as a client or as a server.
5467 For clients only, ``username`` is the username which will be
5468 sent to the server. If omitted it defaults to "qemu".
5469
5470 The dir parameter tells QEMU where to find the keys file. It is
5471 called "dir/keys.psk" and contains "username:key" pairs. This
5472 file can most easily be created using the GnuTLS ``psktool``
5473 program.
5474
5475 For server endpoints, dir may also contain a file dh-params.pem
5476 providing diffie-hellman parameters to use for the TLS server.
5477 If the file is missing, QEMU will generate a set of DH
5478 parameters at startup. This is a computationally expensive
5479 operation that consumes random pool entropy, so it is
5480 recommended that a persistent set of parameters be generated up
5481 front and saved.
5482
5483 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id``
5484 Creates a TLS anonymous credentials object, which can be used to
5485 provide TLS support on network backends. The ``id`` parameter is
5486 a unique ID which network backends will use to access the
5487 credentials. The ``endpoint`` is either ``server`` or ``client``
5488 depending on whether the QEMU network backend that uses the
5489 credentials will be acting as a client or as a server. If
5490 ``verify-peer`` is enabled (the default) then once the handshake
5491 is completed, the peer credentials will be verified. With x509
5492 certificates, this implies that the clients must be provided
5493 with valid client certificates too.
5494
5495 The dir parameter tells QEMU where to find the credential files.
5496 For server endpoints, this directory may contain a file
5497 dh-params.pem providing diffie-hellman parameters to use for the
5498 TLS server. If the file is missing, QEMU will generate a set of
5499 DH parameters at startup. This is a computationally expensive
5500 operation that consumes random pool entropy, so it is
5501 recommended that a persistent set of parameters be generated
5502 upfront and saved.
5503
5504 For x509 certificate credentials the directory will contain
5505 further files providing the x509 certificates. The certificates
5506 must be stored in PEM format, in filenames ca-cert.pem,
5507 ca-crl.pem (optional), server-cert.pem (only servers),
5508 server-key.pem (only servers), client-cert.pem (only clients),
5509 and client-key.pem (only clients).
5510
5511 For the server-key.pem and client-key.pem files which contain
5512 sensitive private keys, it is possible to use an encrypted
5513 version by providing the passwordid parameter. This provides the
5514 ID of a previously created ``secret`` object containing the
5515 password for decryption.
5516
5517 The priority parameter allows to override the global default
5518 priority used by gnutls. This can be useful if the system
5519 administrator needs to use a weaker set of crypto priorities for
5520 QEMU without potentially forcing the weakness onto all
5521 applications. Or conversely if one wants wants a stronger
5522 default for QEMU than for all other applications, they can do
5523 this through this parameter. Its format is a gnutls priority
5524 string as described at
5525 https://gnutls.org/manual/html_node/Priority-Strings.html.
5526
Philippe Mathieu-Daudé993aec22018-10-11 20:21:11 +02005527 ``-object tls-cipher-suites,id=id,priority=priority``
5528 Creates a TLS cipher suites object, which can be used to control
5529 the TLS cipher/protocol algorithms that applications are permitted
5530 to use.
5531
5532 The ``id`` parameter is a unique ID which frontends will use to
5533 access the ordered list of permitted TLS cipher suites from the
5534 host.
5535
5536 The ``priority`` parameter allows to override the global default
5537 priority used by gnutls. This can be useful if the system
5538 administrator needs to use a weaker set of crypto priorities for
5539 QEMU without potentially forcing the weakness onto all
5540 applications. Or conversely if one wants wants a stronger
5541 default for QEMU than for all other applications, they can do
5542 this through this parameter. Its format is a gnutls priority
5543 string as described at
5544 https://gnutls.org/manual/html_node/Priority-Strings.html.
5545
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02005546 An example of use of this object is to control UEFI HTTPS Boot.
5547 The tls-cipher-suites object exposes the ordered list of permitted
5548 TLS cipher suites from the host side to the guest firmware, via
5549 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER
5550 objects. The firmware uses the IANA_TLS_CIPHER array for configuring
5551 guest-side TLS.
5552
5553 In the following example, the priority at which the host-side policy
5554 is retrieved is given by the ``priority`` property.
5555 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to
5556 refer to /etc/crypto-policies/back-ends/gnutls.config.
5557
5558 .. parsed-literal::
5559
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005560 # |qemu_system| \\
5561 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02005562 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0
5563
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005564 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]``
5565 Interval t can't be 0, this filter batches the packet delivery:
5566 all packets arriving in a given interval on netdev netdevid are
5567 delayed until the end of the interval. Interval is in
5568 microseconds. ``status`` is optional that indicate whether the
5569 netfilter is on (enabled) or off (disabled), the default status
5570 for netfilter will be 'on'.
5571
5572 queue all\|rx\|tx is an option that can be applied to any
5573 netfilter.
5574
5575 ``all``: the filter is attached both to the receive and the
5576 transmit queue of the netdev (default).
5577
5578 ``rx``: the filter is attached to the receive queue of the
5579 netdev, where it will receive packets sent to the netdev.
5580
5581 ``tx``: the filter is attached to the transmit queue of the
5582 netdev, where it will receive packets sent by the netdev.
5583
5584 position head\|tail\|id=<id> is an option to specify where the
5585 filter should be inserted in the filter list. It can be applied
5586 to any netfilter.
5587
5588 ``head``: the filter is inserted at the head of the filter list,
5589 before any existing filters.
5590
5591 ``tail``: the filter is inserted at the tail of the filter list,
5592 behind any existing filters (default).
5593
5594 ``id=<id>``: the filter is inserted before or behind the filter
5595 specified by <id>, see the insert option below.
5596
5597 insert behind\|before is an option to specify where to insert
5598 the new filter relative to the one specified with
5599 position=id=<id>. It can be applied to any netfilter.
5600
5601 ``before``: insert before the specified filter.
5602
5603 ``behind``: insert behind the specified filter (default).
5604
5605 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5606 filter-mirror on netdev netdevid,mirror net packet to
5607 chardevchardevid, if it has the vnet\_hdr\_support flag,
5608 filter-mirror will mirror packet with vnet\_hdr\_len.
5609
5610 ``-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]``
5611 filter-redirector on netdev netdevid,redirect filter's net
5612 packet to chardev chardevid,and redirect indev's packet to
5613 filter.if it has the vnet\_hdr\_support flag, filter-redirector
5614 will redirect packet with vnet\_hdr\_len. Create a
5615 filter-redirector we need to differ outdev id from indev id, id
5616 can not be the same. we can just use indev or outdev, but at
5617 least one of indev or outdev need to be specified.
5618
5619 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5620 Filter-rewriter is a part of COLO project.It will rewrite tcp
5621 packet to secondary from primary to keep secondary tcp
5622 connection,and rewrite tcp packet to primary from secondary make
5623 tcp packet can be handled by client.if it has the
5624 vnet\_hdr\_support flag, we can parse packet with vnet header.
5625
5626 usage: colo secondary: -object
5627 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object
5628 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object
5629 filter-rewriter,id=rew0,netdev=hn0,queue=all
5630
5631 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]``
5632 Dump the network traffic on netdev dev to the file specified by
5633 filename. At most len bytes (64k by default) per packet are
5634 stored. The file format is libpcap, so it can be analyzed with
5635 tools such as tcpdump or Wireshark.
5636
Zhang Chena2e5cb72020-06-24 09:20:41 +08005637 ``-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 +08005638 Colo-compare gets packet from primary\_in chardevid and
5639 secondary\_in, then compare whether the payload of primary packet
5640 and secondary packet are the same. If same, it will output
5641 primary packet to out\_dev, else it will notify COLO-framework to do
5642 checkpoint and send primary packet to out\_dev. In order to
5643 improve efficiency, we need to put the task of comparison in
5644 another iothread. If it has the vnet\_hdr\_support flag,
5645 colo compare will send/recv packet with vnet\_hdr\_len.
5646 The compare\_timeout=@var{ms} determines the maximum time of the
5647 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms}
5648 is to set the period of scanning expired primary node network packets.
5649 The max\_queue\_size=@var{size} is to set the max compare queue
5650 size depend on user environment.
5651 If user want to use Xen COLO, need to add the notify\_dev to
Zhang Chen9cc43c92020-03-18 16:23:19 +08005652 notify Xen colo-frame to do checkpoint.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005653
Zhang Chen2b28a7e2020-06-24 09:20:42 +08005654 COLO-compare must be used with the help of filter-mirror,
5655 filter-redirector and filter-rewriter.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005656
5657 ::
5658
5659 KVM COLO
5660
5661 primary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005662 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005663 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005664 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off
5665 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off
5666 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005667 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005668 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005669 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
5670 -object iothread,id=iothread1
5671 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
5672 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
5673 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
5674 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1
5675
5676 secondary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005677 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005678 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
5679 -chardev socket,id=red0,host=3.3.3.3,port=9003
5680 -chardev socket,id=red1,host=3.3.3.3,port=9004
5681 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
5682 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
5683
5684
5685 Xen COLO
5686
5687 primary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005688 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005689 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005690 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off
5691 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off
5692 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005693 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005694 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005695 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005696 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005697 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
5698 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
5699 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
5700 -object iothread,id=iothread1
Manos Pitsidianakis835f3642024-02-20 10:52:23 +02005701 -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 +00005702
5703 secondary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005704 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005705 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
5706 -chardev socket,id=red0,host=3.3.3.3,port=9003
5707 -chardev socket,id=red1,host=3.3.3.3,port=9004
5708 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
5709 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
5710
5711 If you want to know the detail of above command line, you can
5712 read the colo-compare git log.
5713
5714 ``-object cryptodev-backend-builtin,id=id[,queues=queues]``
Stefan Weil1e458f12022-10-30 11:59:44 +01005715 Creates a cryptodev backend which executes crypto operations from
5716 the QEMU cipher APIs. The id parameter is a unique ID that will
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005717 be used to reference this cryptodev backend from the
5718 ``virtio-crypto`` device. The queues parameter is optional,
5719 which specify the queue number of cryptodev backend, the default
5720 of queues is 1.
5721
Peter Maydell09ce5f22020-02-28 15:36:13 +00005722 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005723
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005724 # |qemu_system| \\
5725 [...] \\
5726 -object cryptodev-backend-builtin,id=cryptodev0 \\
5727 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005728 [...]
5729
5730 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]``
5731 Creates a vhost-user cryptodev backend, backed by a chardev
5732 chardevid. The id parameter is a unique ID that will be used to
5733 reference this cryptodev backend from the ``virtio-crypto``
5734 device. The chardev should be a unix domain socket backed one.
5735 The vhost-user uses a specifically defined protocol to pass
5736 vhost ioctl replacement messages to an application on the other
5737 end of the socket. The queues parameter is optional, which
5738 specify the queue number of cryptodev backend for multiqueue
5739 vhost-user, the default of queues is 1.
5740
Peter Maydell09ce5f22020-02-28 15:36:13 +00005741 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005742
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005743 # |qemu_system| \\
5744 [...] \\
5745 -chardev socket,id=chardev0,path=/path/to/socket \\
5746 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\
5747 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005748 [...]
5749
5750 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00005751 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005752 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]``
5753 Defines a secret to store a password, encryption key, or some
5754 other sensitive data. The sensitive data can either be passed
5755 directly via the data parameter, or indirectly via the file
5756 parameter. Using the data parameter is insecure unless the
5757 sensitive data is encrypted.
5758
5759 The sensitive data can be provided in raw format (the default),
5760 or base64. When encoded as JSON, the raw format only supports
5761 valid UTF-8 characters, so base64 is recommended for sending
5762 binary data. QEMU will convert from which ever format is
5763 provided to the format it needs internally. eg, an RBD password
5764 can be provided in raw format, even though it will be base64
5765 encoded when passed onto the RBD sever.
5766
5767 For added protection, it is possible to encrypt the data
5768 associated with a secret using the AES-256-CBC cipher. Use of
5769 encryption is indicated by providing the keyid and iv
5770 parameters. The keyid parameter provides the ID of a previously
5771 defined secret that contains the AES-256 decryption key. This
5772 key should be 32-bytes long and be base64 encoded. The iv
5773 parameter provides the random initialization vector used for
5774 encryption of this particular secret and should be a base64
5775 encrypted string of the 16-byte IV.
5776
5777 The simplest (insecure) usage is to provide the secret inline
5778
Peter Maydell09ce5f22020-02-28 15:36:13 +00005779 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005780
5781 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw
5782
5783 The simplest secure usage is to provide the secret via a file
5784
5785 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object
5786 secret,id=sec0,file=mypasswd.txt,format=raw
5787
5788 For greater security, AES-256-CBC should be used. To illustrate
5789 usage, consider the openssl command line tool which can encrypt
5790 the data. Note that when encrypting, the plaintext must be
5791 padded to the cipher block size (32 bytes) using the standard
5792 PKCS#5/6 compatible padding algorithm.
5793
5794 First a master key needs to be created in base64 encoding:
5795
5796 ::
5797
5798 # openssl rand -base64 32 > key.b64
5799 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
5800
5801 Each secret to be encrypted needs to have a random
5802 initialization vector generated. These do not need to be kept
5803 secret
5804
5805 ::
5806
5807 # openssl rand -base64 16 > iv.b64
5808 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
5809
5810 The secret to be defined can now be encrypted, in this case
5811 we're telling openssl to base64 encode the result, but it could
5812 be left as raw bytes if desired.
5813
5814 ::
5815
5816 # SECRET=$(printf "letmein" |
5817 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
5818
5819 When launching QEMU, create a master secret pointing to
5820 ``key.b64`` and specify that to be used to decrypt the user
5821 password. Pass the contents of ``iv.b64`` to the second secret
5822
Peter Maydell09ce5f22020-02-28 15:36:13 +00005823 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005824
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005825 # |qemu_system| \\
5826 -object secret,id=secmaster0,format=base64,file=key.b64 \\
5827 -object secret,id=sec0,keyid=secmaster0,format=base64,\\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005828 data=$SECRET,iv=$(<iv.b64)
5829
Dov Murik55cdf562021-11-11 10:00:43 +00005830 ``-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 +00005831 Create a Secure Encrypted Virtualization (SEV) guest object,
5832 which can be used to provide the guest memory encryption support
5833 on AMD processors.
5834
5835 When memory encryption is enabled, one of the physical address
5836 bit (aka the C-bit) is utilized to mark if a memory page is
5837 protected. The ``cbitpos`` is used to provide the C-bit
5838 position. The C-bit position is Host family dependent hence user
5839 must provide this value. On EPYC, the value should be 47.
5840
5841 When memory encryption is enabled, we loose certain bits in
5842 physical address space. The ``reduced-phys-bits`` is used to
5843 provide the number of bits we loose in physical address space.
5844 Similar to C-bit, the value is Host family dependent. On EPYC,
Tom Lendacky326e3012022-09-30 10:14:28 -05005845 a guest will lose a maximum of 1 bit, so the value should be 1.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005846
5847 The ``sev-device`` provides the device file to use for
5848 communicating with the SEV firmware running inside AMD Secure
5849 Processor. The default device is '/dev/sev'. If hardware
5850 supports memory encryption then /dev/sev devices are created by
5851 CCP driver.
5852
5853 The ``policy`` provides the guest policy to be enforced by the
5854 SEV firmware and restrict what configuration and operational
5855 commands can be performed on this guest by the hypervisor. The
5856 policy should be provided by the guest owner and is bound to the
5857 guest and cannot be changed throughout the lifetime of the
5858 guest. The default is 0.
5859
5860 If guest ``policy`` allows sharing the key with another SEV
5861 guest then ``handle`` can be use to provide handle of the guest
5862 from which to share the key.
5863
5864 The ``dh-cert-file`` and ``session-file`` provides the guest
5865 owner's Public Diffie-Hillman key defined in SEV spec. The PDH
5866 and session parameters are used for establishing a cryptographic
5867 session with the guest owner to negotiate keys used for
5868 attestation. The file must be encoded in base64.
5869
Dov Murik55cdf562021-11-11 10:00:43 +00005870 The ``kernel-hashes`` adds the hashes of given kernel/initrd/
5871 cmdline to a designated guest firmware page for measured Linux
5872 boot with -kernel. The default is off. (Since 6.2)
5873
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005874 e.g to launch a SEV guest
5875
Peter Maydell09ce5f22020-02-28 15:36:13 +00005876 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005877
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005878 # |qemu_system_x86| \\
5879 ...... \\
Tom Lendacky326e3012022-09-30 10:14:28 -05005880 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \\
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005881 -machine ...,memory-encryption=sev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005882 .....
5883
5884 ``-object authz-simple,id=id,identity=string``
5885 Create an authorization object that will control access to
5886 network services.
5887
5888 The ``identity`` parameter is identifies the user and its format
5889 depends on the network service that authorization object is
5890 associated with. For authorizing based on TLS x509 certificates,
5891 the identity must be the x509 distinguished name. Note that care
5892 must be taken to escape any commas in the distinguished name.
5893
5894 An example authorization object to validate a x509 distinguished
5895 name would look like:
5896
Peter Maydell09ce5f22020-02-28 15:36:13 +00005897 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005898
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005899 # |qemu_system| \\
5900 ... \\
5901 -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 +00005902 ...
5903
5904 Note the use of quotes due to the x509 distinguished name
5905 containing whitespace, and escaping of ','.
5906
Daniel P. Berrangé4d7beea2020-11-04 13:57:21 +00005907 ``-object authz-listfile,id=id,filename=path,refresh=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005908 Create an authorization object that will control access to
5909 network services.
5910
5911 The ``filename`` parameter is the fully qualified path to a file
5912 containing the access control list rules in JSON format.
5913
5914 An example set of rules that match against SASL usernames might
5915 look like:
5916
5917 ::
5918
5919 {
5920 "rules": [
5921 { "match": "fred", "policy": "allow", "format": "exact" },
5922 { "match": "bob", "policy": "allow", "format": "exact" },
5923 { "match": "danb", "policy": "deny", "format": "glob" },
5924 { "match": "dan*", "policy": "allow", "format": "exact" },
5925 ],
5926 "policy": "deny"
5927 }
5928
5929 When checking access the object will iterate over all the rules
5930 and the first rule to match will have its ``policy`` value
5931 returned as the result. If no rules match, then the default
5932 ``policy`` value is returned.
5933
5934 The rules can either be an exact string match, or they can use
5935 the simple UNIX glob pattern matching to allow wildcards to be
5936 used.
5937
5938 If ``refresh`` is set to true the file will be monitored and
5939 automatically reloaded whenever its content changes.
5940
5941 As with the ``authz-simple`` object, the format of the identity
5942 strings being matched depends on the network service, but is
5943 usually a TLS x509 distinguished name, or a SASL username.
5944
5945 An example authorization object to validate a SASL username
5946 would look like:
5947
Peter Maydell09ce5f22020-02-28 15:36:13 +00005948 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005949
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005950 # |qemu_system| \\
5951 ... \\
Daniel P. Berrangé4d7beea2020-11-04 13:57:21 +00005952 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005953 ...
5954
5955 ``-object authz-pam,id=id,service=string``
5956 Create an authorization object that will control access to
5957 network services.
5958
5959 The ``service`` parameter provides the name of a PAM service to
5960 use for authorization. It requires that a file
5961 ``/etc/pam.d/service`` exist to provide the configuration for
5962 the ``account`` subsystem.
5963
5964 An example authorization object to validate a TLS x509
5965 distinguished name would look like:
5966
Peter Maydell09ce5f22020-02-28 15:36:13 +00005967 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005968
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005969 # |qemu_system| \\
5970 ... \\
5971 -object authz-pam,id=auth0,service=qemu-vnc \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005972 ...
5973
5974 There would then be a corresponding config file for PAM at
5975 ``/etc/pam.d/qemu-vnc`` that contains:
5976
5977 ::
5978
5979 account requisite pam_listfile.so item=user sense=allow \
5980 file=/etc/qemu/vnc.allow
5981
5982 Finally the ``/etc/qemu/vnc.allow`` file would contain the list
Stefan Weil1e458f12022-10-30 11:59:44 +01005983 of x509 distinguished names that are permitted access
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005984
5985 ::
5986
5987 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB
5988
Stefano Garzarella1793ad02021-07-21 11:42:10 +02005989 ``-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 +00005990 Creates a dedicated event loop thread that devices can be
5991 assigned to. This is known as an IOThread. By default device
5992 emulation happens in vCPU threads or the main event loop thread.
5993 This can become a scalability bottleneck. IOThreads allow device
5994 emulation and I/O to run on other host CPUs.
5995
5996 The ``id`` parameter is a unique ID that will be used to
5997 reference this IOThread from ``-device ...,iothread=id``.
5998 Multiple devices can be assigned to an IOThread. Note that not
5999 all devices support an ``iothread`` parameter.
6000
6001 The ``query-iothreads`` QMP command lists IOThreads and reports
6002 their thread IDs so that the user can configure host CPU
6003 pinning/affinity.
6004
6005 IOThreads use an adaptive polling algorithm to reduce event loop
6006 latency. Instead of entering a blocking system call to monitor
6007 file descriptors and then pay the cost of being woken up when an
6008 event occurs, the polling algorithm spins waiting for events for
6009 a short time. The algorithm's default parameters are suitable
6010 for many cases but can be adjusted based on knowledge of the
6011 workload and/or host device latency.
6012
6013 The ``poll-max-ns`` parameter is the maximum number of
6014 nanoseconds to busy wait for events. Polling can be disabled by
6015 setting this value to 0.
6016
6017 The ``poll-grow`` parameter is the multiplier used to increase
6018 the polling time when the algorithm detects it is missing events
6019 due to not polling long enough.
6020
6021 The ``poll-shrink`` parameter is the divisor used to decrease
6022 the polling time when the algorithm detects it is spending too
6023 long polling without encountering events.
6024
Stefano Garzarella1793ad02021-07-21 11:42:10 +02006025 The ``aio-max-batch`` parameter is the maximum number of requests
6026 in a batch for the AIO engine, 0 means that the engine will use
6027 its default.
6028
6029 The IOThread parameters can be modified at run-time using the
Peter Maydelle2fcbf42020-03-06 10:07:14 +00006030 ``qom-set`` command (where ``iothread1`` is the IOThread's
6031 ``id``):
6032
6033 ::
6034
6035 (qemu) qom-set /objects/iothread1 poll-max-ns 100000
6036ERST
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01006037
6038
Stefan Weil3dbf2c72010-01-16 18:19:44 +01006039HXCOMM This is the last statement. Insert new options before this line!
Paolo Bonzinifd5fc4b2021-05-17 07:34:21 -04006040
6041#undef DEF
6042#undef DEFHEADING
6043#undef ARCHHEADING