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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
71 to select the value based on accel. For accel=xen the default is
72 off otherwise the default is on.
73
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
154 interleave. Default 256KiB. Only 256KiB, 512KiB, 1024KiB, 2048KiB
155 4096KiB, 8192KiB and 16384KiB granularities supported.
156
157 Example:
158
159 ::
160
161 -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=512k
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"
284 " [,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]\n"
Yanan Wang0d871782021-12-28 17:22:08 +0800285 " set the number of initial CPUs to 'n' [default=1]\n"
Daniel P. Berrangéce8ee7c2021-06-22 15:30:43 +0100286 " maxcpus= maximum number of total CPUs, including\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -0700287 " offline CPUs for hotplug, etc\n"
Pierre Morel5de1aff2023-10-16 20:39:06 +0200288 " drawers= number of drawers on the machine board\n"
289 " books= number of books in one drawer\n"
290 " sockets= number of sockets in one book\n"
Yanan Wang0d871782021-12-28 17:22:08 +0800291 " dies= number of dies in one socket\n"
Yanan Wang864c3b52021-12-28 17:22:09 +0800292 " clusters= number of clusters in one die\n"
293 " cores= number of cores in one cluster\n"
Yanan Wang0d871782021-12-28 17:22:08 +0800294 " threads= number of threads in one core\n"
295 "Note: Different machines may have different subsets of the CPU topology\n"
296 " parameters supported, so the actual meaning of the supported parameters\n"
297 " will vary accordingly. For example, for a machine type that supports a\n"
298 " three-level CPU hierarchy of sockets/cores/threads, the parameters will\n"
299 " sequentially mean as below:\n"
300 " sockets means the number of sockets on the machine board\n"
301 " cores means the number of cores in one socket\n"
302 " threads means the number of threads in one core\n"
303 " For a particular machine type board, an expected CPU topology hierarchy\n"
304 " can be defined through the supported sub-option. Unsupported parameters\n"
305 " can also be provided in addition to the sub-option, but their values\n"
306 " must be set as 1 in the purpose of correct parsing.\n",
307 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000308SRST
Yanan Wang864c3b52021-12-28 17:22:09 +0800309``-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]``
Daniel P. Berrangé80d78352021-06-22 16:17:09 +0100310 Simulate a SMP system with '\ ``n``\ ' CPUs initially present on
311 the machine type board. On boards supporting CPU hotplug, the optional
312 '\ ``maxcpus``\ ' parameter can be set to enable further CPUs to be
Yanan Wang7d8c5a32021-09-29 10:58:05 +0800313 added at runtime. When both parameters are omitted, the maximum number
314 of CPUs will be calculated from the provided topology members and the
315 initial CPU count will match the maximum number. When only one of them
316 is given then the omitted one will be set to its counterpart's value.
317 Both parameters may be specified, but the maximum number of CPUs must
Yanan Wang0d871782021-12-28 17:22:08 +0800318 be equal to or greater than the initial CPU count. Product of the
319 CPU topology hierarchy must be equal to the maximum number of CPUs.
320 Both parameters are subject to an upper limit that is determined by
321 the specific machine type chosen.
Daniel P. Berrangé80d78352021-06-22 16:17:09 +0100322
Yanan Wang0d871782021-12-28 17:22:08 +0800323 To control reporting of CPU topology information, values of the topology
324 parameters can be specified. Machines may only support a subset of the
325 parameters and different machines may have different subsets supported
326 which vary depending on capacity of the corresponding CPU targets. So
327 for a particular machine type board, an expected topology hierarchy can
328 be defined through the supported sub-option. Unsupported parameters can
329 also be provided in addition to the sub-option, but their values must be
330 set as 1 in the purpose of correct parsing.
Daniel P. Berrangé80d78352021-06-22 16:17:09 +0100331
332 Either the initial CPU count, or at least one of the topology parameters
Yanan Wangc2511b12021-09-29 10:58:02 +0800333 must be specified. The specified parameters must be greater than zero,
334 explicit configuration like "cpus=0" is not allowed. Values for any
335 omitted parameters will be computed from those which are given.
Yanan Wang0d871782021-12-28 17:22:08 +0800336
337 For example, the following sub-option defines a CPU topology hierarchy
338 (2 sockets totally on the machine, 2 cores per socket, 2 threads per
339 core) for a machine that only supports sockets/cores/threads.
340 Some members of the option can be omitted but their values will be
341 automatically computed:
342
343 ::
344
345 -smp 8,sockets=2,cores=2,threads=2,maxcpus=8
346
347 The following sub-option defines a CPU topology hierarchy (2 sockets
348 totally on the machine, 2 dies per socket, 2 cores per die, 2 threads
349 per core) for PC machines which support sockets/dies/cores/threads.
350 Some members of the option can be omitted but their values will be
351 automatically computed:
352
353 ::
354
355 -smp 16,sockets=2,dies=2,cores=2,threads=2,maxcpus=16
356
Yanan Wangd55c3162022-01-07 16:32:27 +0800357 The following sub-option defines a CPU topology hierarchy (2 sockets
358 totally on the machine, 2 clusters per socket, 2 cores per cluster,
359 2 threads per core) for ARM virt machines which support sockets/clusters
360 /cores/threads. Some members of the option can be omitted but their values
361 will be automatically computed:
362
363 ::
364
365 -smp 16,sockets=2,clusters=2,cores=2,threads=2,maxcpus=16
366
Yanan Wangc2511b12021-09-29 10:58:02 +0800367 Historically preference was given to the coarsest topology parameters
368 when computing missing values (ie sockets preferred over cores, which
369 were preferred over threads), however, this behaviour is considered
Yanan Wang4a0af292021-09-29 10:58:09 +0800370 liable to change. Prior to 6.2 the preference was sockets over cores
371 over threads. Since 6.2 the preference is cores over sockets over threads.
Yanan Wang0d871782021-12-28 17:22:08 +0800372
373 For example, the following option defines a machine board with 2 sockets
374 of 1 core before 6.2 and 1 socket of 2 cores after 6.2:
375
376 ::
377
378 -smp 2
Yicong Yang97f4eff2022-12-29 14:55:09 +0800379
380 Note: The cluster topology will only be generated in ACPI and exposed
381 to guest if it's explicitly specified in -smp.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000382ERST
blueswir15824d652009-03-28 06:44:27 +0000383
aliguori268a3622009-04-21 22:30:27 +0000384DEF("numa", HAS_ARG, QEMU_OPTION_numa,
Tao Xu244b3f42019-12-13 09:19:22 +0800385 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n"
386 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n"
Igor Mammedov2d19c652017-11-28 15:53:58 +0100387 "-numa dist,src=source,dst=destination,val=distance\n"
Liu Jingqi9b12dfa2019-12-13 09:19:23 +0800388 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n"
Liu Jingqic412a482019-12-13 09:19:24 +0800389 "-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"
390 "-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 +0100391 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000392SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000393``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]``
394 \
395``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]``
396 \
397``-numa dist,src=source,dst=destination,val=distance``
398 \
399``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]``
400 \
Stefan Weil2cb40d42022-11-10 20:08:25 +0100401``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=type[,latency=lat][,bandwidth=bw]``
Peter Maydell09ce5f22020-02-28 15:36:13 +0000402 \
403``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000404 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA
405 distance from a source node to a destination node. Set the ACPI
406 Heterogeneous Memory Attributes for the given nodes.
407
408 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and
409 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a
410 contiguous range of CPU indexes (or a single VCPU if lastcpu is
411 omitted). A non-contiguous set of VCPUs can be represented by
412 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is
413 omitted on all nodes, VCPUs are automatically split between them.
414
415 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a
416 NUMA node:
417
418 ::
419
420 -numa node,cpus=0-2,cpus=5
421
422 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option
423 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to
424 assign CPU objects to a node using topology layout properties of
425 CPU. The set of properties is machine specific, and depends on used
426 machine type/'\ ``smp``\ ' options. It could be queried with
427 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ '
428 property specifies node to which CPU object will be assigned, it's
429 required for node to be declared with '\ ``node``\ ' option before
430 it's used with '\ ``cpu``\ ' option.
431
432 For example:
433
434 ::
435
436 -M pc \
437 -smp 1,sockets=2,maxcpus=2 \
438 -numa node,nodeid=0 -numa node,nodeid=1 \
439 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
440
Yohei Kojima4f513982023-04-24 10:22:45 +0100441 '\ ``memdev``\ ' option assigns RAM from a given memory backend
442 device to a node. It is recommended to use '\ ``memdev``\ ' option
443 over legacy '\ ``mem``\ ' option. This is because '\ ``memdev``\ '
444 option provides better performance and more control over the
445 backend's RAM (e.g. '\ ``prealloc``\ ' parameter of
446 '\ ``-memory-backend-ram``\ ' allows memory preallocation).
Igor Mammedov32a354d2020-06-09 09:56:35 -0400447
Yohei Kojima4f513982023-04-24 10:22:45 +0100448 For compatibility reasons, legacy '\ ``mem``\ ' option is
449 supported in 5.0 and older machine types. Note that '\ ``mem``\ '
450 and '\ ``memdev``\ ' are mutually exclusive. If one node uses
451 '\ ``memdev``\ ', the rest nodes have to use '\ ``memdev``\ '
452 option, and vice versa.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000453
Yohei Kojima4f513982023-04-24 10:22:45 +0100454 Users must specify memory for all NUMA nodes by '\ ``memdev``\ '
455 (or legacy '\ ``mem``\ ' if available). In QEMU 5.2, the support
456 for '\ ``-numa node``\ ' without memory specified was removed.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000457
458 '\ ``initiator``\ ' is an additional option that points to an
459 initiator NUMA node that has best performance (the lowest latency or
460 largest bandwidth) to this NUMA node. Note that this option can be
461 set only when the machine property 'hmat' is set to 'on'.
462
463 Following example creates a machine with 2 NUMA nodes, node 0 has
464 CPU. node 1 has only memory, and its initiator is node 0. Note that
465 because node 0 has CPU, by default the initiator of node 0 is itself
466 and must be itself.
467
468 ::
469
470 -machine hmat=on \
471 -m 2G,slots=2,maxmem=4G \
472 -object memory-backend-ram,size=1G,id=m0 \
473 -object memory-backend-ram,size=1G,id=m1 \
474 -numa node,nodeid=0,memdev=m0 \
475 -numa node,nodeid=1,memdev=m1,initiator=0 \
476 -smp 2,sockets=2,maxcpus=2 \
477 -numa cpu,node-id=0,socket-id=0 \
478 -numa cpu,node-id=0,socket-id=1
479
480 source and destination are NUMA node IDs. distance is the NUMA
481 distance from source to destination. The distance from a node to
482 itself is always 10. If any pair of nodes is given a distance, then
483 all pairs must be given distances. Although, when distances are only
484 given in one direction for each pair of nodes, then the distances in
485 the opposite directions are assumed to be the same. If, however, an
486 asymmetrical pair of distances is given for even one node pair, then
487 all node pairs must be provided distance values for both directions,
488 even when they are symmetrical. When a node is unreachable from
489 another node, set the pair's distance to 255.
490
491 Note that the -``numa`` option doesn't allocate any of the specified
492 resources, it just assigns existing resources to NUMA nodes. This
493 means that one still has to use the ``-m``, ``-smp`` options to
494 allocate RAM and VCPUs respectively.
495
496 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth
497 Information between initiator and target NUMA nodes in ACPI
498 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can
499 create memory requests, usually it has one or more processors.
500 Target NUMA node contains addressable memory.
501
502 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is
503 the memory hierarchy of the target NUMA node: if hierarchy is
504 'memory', the structure represents the memory performance; if
505 hierarchy is 'first-level\|second-level\|third-level', this
506 structure represents aggregated performance of memory side caches
507 for each domain. type of 'data-type' is type of data represented by
508 this structure instance: if 'hierarchy' is 'memory', 'data-type' is
509 'access\|read\|write' latency or 'access\|read\|write' bandwidth of
510 the target memory; if 'hierarchy' is
511 'first-level\|second-level\|third-level', 'data-type' is
512 'access\|read\|write' hit latency or 'access\|read\|write' hit
513 bandwidth of the target memory side cache.
514
515 lat is latency value in nanoseconds. bw is bandwidth value, the
516 possible value and units are NUM[M\|G\|T], mean that the bandwidth
517 value are NUM byte per second (or MB/s, GB/s or TB/s depending on
518 used suffix). Note that if latency or bandwidth value is 0, means
519 the corresponding latency or bandwidth information is not provided.
520
521 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory
522 belongs. size is the size of memory side cache in bytes. level is
523 the cache level described in this structure, note that the cache
524 level 0 should not be used with '\ ``hmat-cache``\ ' option.
525 associativity is the cache associativity, the possible value is
526 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy
527 is the write policy. line is the cache Line size in bytes.
528
529 For example, the following options describe 2 NUMA nodes. Node 0 has
530 2 cpus and a ram, node 1 has only a ram. The processors in node 0
531 access memory in node 0 with access-latency 5 nanoseconds,
532 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access
533 memory in NUMA node 1 with access-latency 10 nanoseconds,
534 access-bandwidth is 100 MB/s. And for memory side cache information,
535 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB,
536 policy is write-back, the cache Line size is 8 bytes:
537
538 ::
539
540 -machine hmat=on \
541 -m 2G \
542 -object memory-backend-ram,size=1G,id=m0 \
543 -object memory-backend-ram,size=1G,id=m1 \
Yanan Wang848dd262021-09-28 20:11:34 +0800544 -smp 2,sockets=2,maxcpus=2 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000545 -numa node,nodeid=0,memdev=m0 \
546 -numa node,nodeid=1,memdev=m1,initiator=0 \
547 -numa cpu,node-id=0,socket-id=0 \
548 -numa cpu,node-id=0,socket-id=1 \
549 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \
550 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \
551 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \
552 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \
553 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \
554 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8
555ERST
aliguori268a3622009-04-21 22:30:27 +0000556
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100557DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
558 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
559 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000560SRST
561``-add-fd fd=fd,set=set[,opaque=opaque]``
562 Add a file descriptor to an fd set. Valid options are:
563
564 ``fd=fd``
565 This option defines the file descriptor of which a duplicate is
566 added to fd set. The file descriptor cannot be stdin, stdout, or
567 stderr.
568
569 ``set=set``
570 This option defines the ID of the fd set to add the file
571 descriptor to.
572
573 ``opaque=opaque``
574 This option defines a free-form string that can be used to
575 describe fd.
576
577 You can open an image using pre-opened file descriptors from an fd
578 set:
579
580 .. parsed-literal::
581
Laszlo Ersek353a06b2020-09-08 19:21:11 +0200582 |qemu_system| \\
583 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\
584 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000585 -drive file=/dev/fdset/2,index=0,media=disk
586ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100587
588DEF("set", HAS_ARG, QEMU_OPTION_set,
589 "-set group.id.arg=value\n"
590 " set <arg> parameter for item <id> of type <group>\n"
591 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000592SRST
593``-set group.id.arg=value``
594 Set parameter arg for item id of type group
595ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100596
597DEF("global", HAS_ARG, QEMU_OPTION_global,
Paolo Bonzini3751d7c2015-04-09 14:16:19 +0200598 "-global driver.property=value\n"
599 "-global driver=driver,property=property,value=value\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100600 " set a global default for a driver property\n",
601 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000602SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000603``-global driver.prop=value``
604 \
605``-global driver=driver,property=property,value=value``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000606 Set default value of driver's property prop to value, e.g.:
607
608 .. parsed-literal::
609
610 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img
611
612 In particular, you can use this to set driver properties for devices
613 which are created automatically by the machine model. To create a
614 device which is not created automatically and set properties on it,
615 use -``device``.
616
617 -global driver.prop=value is shorthand for -global
618 driver=driver,property=prop,value=value. The longhand syntax works
619 even when driver contains a dot.
620ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100621
622DEF("boot", HAS_ARG, QEMU_OPTION_boot,
623 "-boot [order=drives][,once=drives][,menu=on|off]\n"
Amos Kongc8a6ae82013-03-19 14:23:27 +0800624 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100625 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
626 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
627 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
628 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
629 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000630SRST
631``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]``
632 Specify boot order drives as a string of drive letters. Valid drive
633 letters depend on the target architecture. The x86 PC uses: a, b
634 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p
635 (Etherboot from network adapter 1-4), hard disk boot is the default.
636 To apply a particular boot order only on the first startup, specify
637 it via ``once``. Note that the ``order`` or ``once`` parameter
638 should not be used together with the ``bootindex`` property of
639 devices, since the firmware implementations normally do not support
640 both at the same time.
641
642 Interactive boot menus/prompts can be enabled via ``menu=on`` as far
643 as firmware/BIOS supports them. The default is non-interactive boot.
644
645 A splash picture could be passed to bios, enabling user to show it
646 as logo, when option splash=sp\_name is given and menu=on, If
647 firmware/BIOS supports them. Currently Seabios for X86 system
648 support it. limitation: The splash file could be a jpeg file or a
649 BMP file in 24 BPP format(true color). The resolution should be
650 supported by the SVGA mode, so the recommended is 320x240, 640x480,
651 800x640.
652
653 A timeout could be passed to bios, guest will pause for rb\_timeout
654 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will
655 not reboot, qemu passes '-1' to bios by default. Currently Seabios
656 for X86 system support it.
657
658 Do strict boot via ``strict=on`` as far as firmware/BIOS supports
659 it. This only effects when boot priority is changed by bootindex
660 options. The default is non-strict boot.
661
Peter Maydell09ce5f22020-02-28 15:36:13 +0000662 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000663
664 # try to boot from network first, then from hard disk
665 |qemu_system_x86| -boot order=nc
666 # boot from CD-ROM first, switch back to default order after reboot
667 |qemu_system_x86| -boot once=d
668 # boot with a splash picture for 5 seconds.
669 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000
670
671 Note: The legacy format '-boot drives' is still supported but its
672 use is discouraged as it may be removed from future versions.
673ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100674
675DEF("m", HAS_ARG, QEMU_OPTION_m,
Michael Tokarev89f3ea22016-11-10 17:51:32 +0300676 "-m [size=]megs[,slots=n,maxmem=size]\n"
Igor Mammedov6e1d3c12013-11-27 01:27:35 +0100677 " configure guest RAM\n"
Alexander Graf0daba1f2015-06-05 11:05:03 +0200678 " size: initial amount of guest memory\n"
Igor Mammedovc270fb92014-06-02 15:25:02 +0200679 " slots: number of hotplug slots (default: none)\n"
Matthew Rosatob6fe0122014-08-28 11:25:33 -0400680 " maxmem: maximum amount of guest memory (default: none)\n"
Thomas Hutha635bcf2023-07-03 09:56:46 +0200681 " Note: Some architectures might enforce a specific granularity\n",
Igor Mammedov6e1d3c12013-11-27 01:27:35 +0100682 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000683SRST
684``-m [size=]megs[,slots=n,maxmem=size]``
685 Sets guest startup RAM size to megs megabytes. Default is 128 MiB.
686 Optionally, a suffix of "M" or "G" can be used to signify a value in
687 megabytes or gigabytes respectively. Optional pair slots, maxmem
688 could be used to set amount of hotpluggable memory slots and maximum
689 amount of memory. Note that maxmem must be aligned to the page size.
690
691 For example, the following command-line sets the guest startup RAM
692 size to 1GB, creates 3 slots to hotplug additional memory and sets
693 the maximum memory the guest can reach to 4GB:
694
695 .. parsed-literal::
696
697 |qemu_system| -m 1G,slots=3,maxmem=4G
698
699 If slots and maxmem are not specified, memory hotplug won't be
700 enabled and the guest startup RAM will never increase.
701ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100702
703DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
704 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000705SRST
706``-mem-path path``
707 Allocate guest RAM from a temporarily created file in path.
708ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100709
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100710DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
711 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
712 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000713SRST
714``-mem-prealloc``
715 Preallocate memory when using -mem-path.
716ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100717
718DEF("k", HAS_ARG, QEMU_OPTION_k,
719 "-k language use keyboard layout (for example 'fr' for French)\n",
720 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000721SRST
722``-k language``
723 Use keyboard layout language (for example ``fr`` for French). This
724 option is only needed where it is not easy to get raw PC keycodes
725 (e.g. on Macs, with some X11 servers or with a VNC or curses
726 display). You don't normally need to use it on PC/Linux or
727 PC/Windows hosts.
728
729 The available layouts are:
730
731 ::
732
733 ar de-ch es fo fr-ca hu ja mk no pt-br sv
734 da en-gb et fr fr-ch is lt nl pl ru th
735 de en-us fi fr-be hr it lv nl-be pt sl tr
736
737 The default is ``en-us``.
738ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100739
740
Paolo Bonzini039a6832022-04-27 12:27:46 +0200741DEF("audio", HAS_ARG, QEMU_OPTION_audio,
Paolo Bonzini1ebdbff2023-09-21 10:23:58 +0200742 "-audio [driver=]driver[,prop[=value][,...]]\n"
743 " specifies default audio backend when `audiodev` is not\n"
744 " used to create a machine or sound device;"
745 " options are the same as for -audiodev\n"
Paolo Bonzini039a6832022-04-27 12:27:46 +0200746 "-audio [driver=]driver,model=value[,prop[=value][,...]]\n"
747 " specifies the audio backend and device to use;\n"
748 " apart from 'model', options are the same as for -audiodev.\n"
749 " use '-audio model=help' to show possible devices.\n",
750 QEMU_ARCH_ALL)
751SRST
Paolo Bonzini1ebdbff2023-09-21 10:23:58 +0200752``-audio [driver=]driver[,model=value][,prop[=value][,...]]``
753 If the ``model`` option is specified, ``-audio`` is a shortcut
754 for configuring both the guest audio hardware and the host audio
755 backend in one go. The guest hardware model can be set with
756 ``model=modelname``. Use ``model=help`` to list the available
757 device types.
Paolo Bonzini039a6832022-04-27 12:27:46 +0200758
759 The following two example do exactly the same, to show how ``-audio``
760 can be used to shorten the command line length:
761
762 .. parsed-literal::
763
764 |qemu_system| -audiodev pa,id=pa -device sb16,audiodev=pa
765 |qemu_system| -audio pa,model=sb16
Paolo Bonzini1ebdbff2023-09-21 10:23:58 +0200766
767 If the ``model`` option is not specified, ``-audio`` is used to
768 configure a default audio backend that will be used whenever the
769 ``audiodev`` property is not set on a device or machine. In
770 particular, ``-audio none`` ensures that no audio is produced even
771 for machines that have embedded sound hardware.
772
773 In both cases, the driver option is the same as with the corresponding
774 ``-audiodev`` option below. Use ``driver=help`` to list the available
775 drivers.
776
Paolo Bonzini039a6832022-04-27 12:27:46 +0200777ERST
778
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100779DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev,
780 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n"
781 " specifies the audio backend to use\n"
Claudio Fontana5e03b6d2022-09-08 10:14:41 +0200782 " Use ``-audiodev help`` to list the available drivers\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100783 " id= identifier of the backend\n"
784 " timer-period= timer period in microseconds\n"
Kővágó, Zoltán8efac072019-10-13 21:57:58 +0200785 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100786 " in|out.fixed-settings= use fixed settings for host audio\n"
787 " in|out.frequency= frequency to use with fixed settings\n"
788 " in|out.channels= number of channels to use with fixed settings\n"
789 " in|out.format= sample format to use with fixed settings\n"
Volker Rümelin49f77e62020-03-08 20:33:21 +0100790 " valid values: s8, s16, s32, u8, u16, u32, f32\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100791 " in|out.voices= number of voices to use\n"
Stefan Hajnoczi86247252019-09-18 10:53:33 +0100792 " in|out.buffer-length= length of buffer in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100793 "-audiodev none,id=id,[,prop[=value][,...]]\n"
794 " dummy driver that discards all output\n"
795#ifdef CONFIG_AUDIO_ALSA
796 "-audiodev alsa,id=id[,prop[=value][,...]]\n"
797 " in|out.dev= name of the audio device to use\n"
Stefan Hajnoczidfc54342019-09-18 10:53:35 +0100798 " in|out.period-length= length of period in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100799 " in|out.try-poll= attempt to use poll mode\n"
800 " threshold= threshold (in microseconds) when playback starts\n"
801#endif
802#ifdef CONFIG_AUDIO_COREAUDIO
803 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n"
804 " in|out.buffer-count= number of buffers\n"
805#endif
806#ifdef CONFIG_AUDIO_DSOUND
807 "-audiodev dsound,id=id[,prop[=value][,...]]\n"
808 " latency= add extra latency to playback in microseconds\n"
809#endif
810#ifdef CONFIG_AUDIO_OSS
811 "-audiodev oss,id=id[,prop[=value][,...]]\n"
812 " in|out.dev= path of the audio device to use\n"
813 " in|out.buffer-count= number of buffers\n"
814 " in|out.try-poll= attempt to use poll mode\n"
815 " try-mmap= try using memory mapped access\n"
816 " exclusive= open device in exclusive mode\n"
817 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n"
818#endif
819#ifdef CONFIG_AUDIO_PA
820 "-audiodev pa,id=id[,prop[=value][,...]]\n"
821 " server= PulseAudio server address\n"
822 " in|out.name= source/sink device name\n"
Stefan Hajnoczi14d4f012019-10-04 13:56:41 +0100823 " in|out.latency= desired latency in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100824#endif
Dorinda Basseyc2d3d1c2023-04-17 12:56:54 +0200825#ifdef CONFIG_AUDIO_PIPEWIRE
826 "-audiodev pipewire,id=id[,prop[=value][,...]]\n"
827 " in|out.name= source/sink device name\n"
828 " in|out.stream-name= name of pipewire stream\n"
829 " in|out.latency= desired latency in microseconds\n"
830#endif
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100831#ifdef CONFIG_AUDIO_SDL
832 "-audiodev sdl,id=id[,prop[=value][,...]]\n"
Volker Rümelin5a0926c2021-01-10 11:02:19 +0100833 " in|out.buffer-count= number of buffers\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100834#endif
Alexandre Ratchov663df1c2022-09-07 15:23:42 +0200835#ifdef CONFIG_AUDIO_SNDIO
836 "-audiodev sndio,id=id[,prop[=value][,...]]\n"
837#endif
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100838#ifdef CONFIG_SPICE
839 "-audiodev spice,id=id[,prop[=value][,...]]\n"
840#endif
Marc-André Lureau739362d2021-03-09 17:15:28 +0400841#ifdef CONFIG_DBUS_DISPLAY
842 "-audiodev dbus,id=id[,prop[=value][,...]]\n"
843#endif
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100844 "-audiodev wav,id=id[,prop[=value][,...]]\n"
845 " path= path of wav file to record\n",
846 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000847SRST
848``-audiodev [driver=]driver,id=id[,prop[=value][,...]]``
849 Adds a new audio backend driver identified by id. There are global
850 and driver specific properties. Some values can be set differently
851 for input and output, they're marked with ``in|out.``. You can set
852 the input's property with ``in.prop`` and the output's property with
853 ``out.prop``. For example:
854
855 ::
856
857 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000
858 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified
859
860 NOTE: parameter validation is known to be incomplete, in many cases
861 specifying an invalid option causes QEMU to print an error message
862 and continue emulation without sound.
863
864 Valid global options are:
865
866 ``id=identifier``
867 Identifies the audio backend.
868
869 ``timer-period=period``
870 Sets the timer period used by the audio subsystem in
871 microseconds. Default is 10000 (10 ms).
872
873 ``in|out.mixing-engine=on|off``
874 Use QEMU's mixing engine to mix all streams inside QEMU and
875 convert audio formats when not supported by the backend. When
876 off, fixed-settings must be off too. Note that disabling this
877 option means that the selected backend must support multiple
878 streams and the audio formats used by the virtual cards,
879 otherwise you'll get no sound. It's not recommended to disable
880 this option unless you want to use 5.1 or 7.1 audio, as mixing
881 engine only supports mono and stereo audio. Default is on.
882
883 ``in|out.fixed-settings=on|off``
884 Use fixed settings for host audio. When off, it will change
885 based on how the guest opens the sound card. In this case you
886 must not specify frequency, channels or format. Default is on.
887
888 ``in|out.frequency=frequency``
889 Specify the frequency to use when using fixed-settings. Default
890 is 44100Hz.
891
892 ``in|out.channels=channels``
893 Specify the number of channels to use when using fixed-settings.
894 Default is 2 (stereo).
895
896 ``in|out.format=format``
897 Specify the sample format to use when using fixed-settings.
898 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``,
Volker Rümelin49f77e62020-03-08 20:33:21 +0100899 ``u32``, ``f32``. Default is ``s16``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000900
901 ``in|out.voices=voices``
902 Specify the number of voices to use. Default is 1.
903
904 ``in|out.buffer-length=usecs``
905 Sets the size of the buffer in microseconds.
906
907``-audiodev none,id=id[,prop[=value][,...]]``
908 Creates a dummy backend that discards all outputs. This backend has
909 no backend specific properties.
910
911``-audiodev alsa,id=id[,prop[=value][,...]]``
912 Creates backend using the ALSA. This backend is only available on
913 Linux.
914
915 ALSA specific options are:
916
917 ``in|out.dev=device``
918 Specify the ALSA device to use for input and/or output. Default
919 is ``default``.
920
921 ``in|out.period-length=usecs``
922 Sets the period length in microseconds.
923
924 ``in|out.try-poll=on|off``
925 Attempt to use poll mode with the device. Default is on.
926
927 ``threshold=threshold``
928 Threshold (in microseconds) when playback starts. Default is 0.
929
930``-audiodev coreaudio,id=id[,prop[=value][,...]]``
931 Creates a backend using Apple's Core Audio. This backend is only
932 available on Mac OS and only supports playback.
933
934 Core Audio specific options are:
935
936 ``in|out.buffer-count=count``
937 Sets the count of the buffers.
938
939``-audiodev dsound,id=id[,prop[=value][,...]]``
940 Creates a backend using Microsoft's DirectSound. This backend is
941 only available on Windows and only supports playback.
942
943 DirectSound specific options are:
944
945 ``latency=usecs``
946 Add extra usecs microseconds latency to playback. Default is
947 10000 (10 ms).
948
949``-audiodev oss,id=id[,prop[=value][,...]]``
950 Creates a backend using OSS. This backend is available on most
951 Unix-like systems.
952
953 OSS specific options are:
954
955 ``in|out.dev=device``
956 Specify the file name of the OSS device to use. Default is
957 ``/dev/dsp``.
958
959 ``in|out.buffer-count=count``
960 Sets the count of the buffers.
961
962 ``in|out.try-poll=on|of``
963 Attempt to use poll mode with the device. Default is on.
964
965 ``try-mmap=on|off``
966 Try using memory mapped device access. Default is off.
967
968 ``exclusive=on|off``
969 Open the device in exclusive mode (vmix won't work in this
970 case). Default is off.
971
972 ``dsp-policy=policy``
973 Sets the timing policy (between 0 and 10, where smaller number
974 means smaller latency but higher CPU usage). Use -1 to use
975 buffer sizes specified by ``buffer`` and ``buffer-count``. This
976 option is ignored if you do not have OSS 4. Default is 5.
977
978``-audiodev pa,id=id[,prop[=value][,...]]``
979 Creates a backend using PulseAudio. This backend is available on
980 most systems.
981
982 PulseAudio specific options are:
983
984 ``server=server``
985 Sets the PulseAudio server to connect to.
986
987 ``in|out.name=sink``
988 Use the specified source/sink for recording/playback.
989
990 ``in|out.latency=usecs``
991 Desired latency in microseconds. The PulseAudio server will try
992 to honor this value but actual latencies may be lower or higher.
993
Dorinda Basseyc2d3d1c2023-04-17 12:56:54 +0200994``-audiodev pipewire,id=id[,prop[=value][,...]]``
Marc-André Lureau20c51242023-05-06 20:37:26 +0400995 Creates a backend using PipeWire. This backend is available on
Dorinda Basseyc2d3d1c2023-04-17 12:56:54 +0200996 most systems.
997
Marc-André Lureau20c51242023-05-06 20:37:26 +0400998 PipeWire specific options are:
Dorinda Basseyc2d3d1c2023-04-17 12:56:54 +0200999
1000 ``in|out.latency=usecs``
1001 Desired latency in microseconds.
1002
1003 ``in|out.name=sink``
1004 Use the specified source/sink for recording/playback.
1005
1006 ``in|out.stream-name``
1007 Specify the name of pipewire stream.
1008
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001009``-audiodev sdl,id=id[,prop[=value][,...]]``
1010 Creates a backend using SDL. This backend is available on most
1011 systems, but you should use your platform's native backend if
Volker Rümelin5a0926c2021-01-10 11:02:19 +01001012 possible.
1013
1014 SDL specific options are:
1015
1016 ``in|out.buffer-count=count``
1017 Sets the count of the buffers.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001018
Alexandre Ratchov663df1c2022-09-07 15:23:42 +02001019``-audiodev sndio,id=id[,prop[=value][,...]]``
1020 Creates a backend using SNDIO. This backend is available on
1021 OpenBSD and most other Unix-like systems.
1022
1023 Sndio specific options are:
1024
1025 ``in|out.dev=device``
1026 Specify the sndio device to use for input and/or output. Default
1027 is ``default``.
1028
1029 ``in|out.latency=usecs``
1030 Sets the desired period length in microseconds.
1031
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001032``-audiodev spice,id=id[,prop[=value][,...]]``
1033 Creates a backend that sends audio through SPICE. This backend
1034 requires ``-spice`` and automatically selected in that case, so
1035 usually you can ignore this option. This backend has no backend
1036 specific properties.
1037
1038``-audiodev wav,id=id[,prop[=value][,...]]``
1039 Creates a backend that writes audio to a WAV file.
1040
1041 Backend specific options are:
1042
1043 ``path=path``
1044 Write recorded audio into the specified file. Default is
1045 ``qemu.wav``.
1046ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001047
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001048DEF("device", HAS_ARG, QEMU_OPTION_device,
1049 "-device driver[,prop[=value][,...]]\n"
1050 " add device (based on driver)\n"
1051 " prop=value,... sets driver properties\n"
1052 " use '-device help' to print all possible drivers\n"
1053 " use '-device driver,help' to print all possible properties\n",
1054 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001055SRST
1056``-device driver[,prop[=value][,...]]``
1057 Add device driver. prop=value sets driver properties. Valid
1058 properties depend on the driver. To get help on possible drivers and
1059 properties, use ``-device help`` and ``-device driver,help``.
1060
1061 Some drivers are:
1062
Corey Minyard789101b2020-07-17 11:37:02 -05001063``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001064 Add an IPMI BMC. This is a simulation of a hardware management
1065 interface processor that normally sits on a system. It provides a
1066 watchdog and the ability to reset and power control the system. You
1067 need to connect this to an IPMI interface to make it useful
1068
1069 The IPMI slave address to use for the BMC. The default is 0x20. This
1070 address is the BMC's address on the I2C network of management
1071 controllers. If you don't know what this means, it is safe to ignore
1072 it.
1073
1074 ``id=id``
1075 The BMC id for interfaces to use this device.
1076
1077 ``slave_addr=val``
1078 Define slave address to use for the BMC. The default is 0x20.
1079
1080 ``sdrfile=file``
1081 file containing raw Sensor Data Records (SDR) data. The default
1082 is none.
1083
1084 ``fruareasize=val``
1085 size of a Field Replaceable Unit (FRU) area. The default is
1086 1024.
1087
1088 ``frudatafile=file``
1089 file containing raw Field Replaceable Unit (FRU) inventory data.
1090 The default is none.
1091
1092 ``guid=uuid``
1093 value for the GUID for the BMC, in standard UUID format. If this
1094 is set, get "Get GUID" command to the BMC will return it.
1095 Otherwise "Get GUID" will return an error.
1096
1097``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]``
1098 Add a connection to an external IPMI BMC simulator. Instead of
1099 locally emulating the BMC like the above item, instead connect to an
1100 external entity that provides the IPMI services.
1101
1102 A connection is made to an external BMC simulator. If you do this,
1103 it is strongly recommended that you use the "reconnect=" chardev
1104 option to reconnect to the simulator if the connection is lost. Note
1105 that if this is not used carefully, it can be a security issue, as
1106 the interface has the ability to send resets, NMIs, and power off
1107 the VM. It's best if QEMU makes a connection to an external
1108 simulator running on a secure port on localhost, so neither the
1109 simulator nor QEMU is exposed to any outside network.
1110
1111 See the "lanserv/README.vm" file in the OpenIPMI library for more
1112 details on the external interface.
1113
1114``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]``
Stefan Weil1e458f12022-10-30 11:59:44 +01001115 Add a KCS IPMI interface on the ISA bus. This also adds a
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001116 corresponding ACPI and SMBIOS entries, if appropriate.
1117
1118 ``bmc=id``
1119 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern
1120 above.
1121
1122 ``ioport=val``
1123 Define the I/O address of the interface. The default is 0xca0
1124 for KCS.
1125
1126 ``irq=val``
1127 Define the interrupt to use. The default is 5. To disable
1128 interrupts, set this to 0.
1129
1130``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]``
1131 Like the KCS interface, but defines a BT interface. The default port
1132 is 0xe4 and the default interrupt is 5.
Corey Minyard323679d2019-09-23 13:50:33 -05001133
1134``-device pci-ipmi-kcs,bmc=id``
Stefan Weil1e458f12022-10-30 11:59:44 +01001135 Add a KCS IPMI interface on the PCI bus.
Corey Minyard323679d2019-09-23 13:50:33 -05001136
1137 ``bmc=id``
1138 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
1139
1140``-device pci-ipmi-bt,bmc=id``
1141 Like the KCS interface, but defines a BT interface on the PCI bus.
Peter Xu7395b3e2021-07-07 11:41:14 -04001142
1143``-device intel-iommu[,option=...]``
1144 This is only supported by ``-machine q35``, which will enable Intel VT-d
1145 emulation within the guest. It supports below options:
1146
1147 ``intremap=on|off`` (default: auto)
1148 This enables interrupt remapping feature. It's required to enable
1149 complete x2apic. Currently it only supports kvm kernel-irqchip modes
1150 ``off`` or ``split``, while full kernel-irqchip is not yet supported.
1151 The default value is "auto", which will be decided by the mode of
1152 kernel-irqchip.
1153
1154 ``caching-mode=on|off`` (default: off)
1155 This enables caching mode for the VT-d emulated device. When
1156 caching-mode is enabled, each guest DMA buffer mapping will generate an
1157 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in
1158 a synchronous way. It is required for ``-device vfio-pci`` to work
1159 with the VT-d device, because host assigned devices requires to setup
1160 the DMA mapping on the host before guest DMA starts.
1161
1162 ``device-iotlb=on|off`` (default: off)
1163 This enables device-iotlb capability for the emulated VT-d device. So
1164 far virtio/vhost should be the only real user for this parameter,
1165 paired with ats=on configured for the device.
1166
1167 ``aw-bits=39|48`` (default: 39)
1168 This decides the address width of IOVA address space. The address
1169 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for
1170 4-level IOMMU page tables.
1171
1172 Please also refer to the wiki page for general scenarios of VT-d
1173 emulation in QEMU: https://wiki.qemu.org/Features/VT-d.
1174
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001175ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001176
1177DEF("name", HAS_ARG, QEMU_OPTION_name,
Dr. David Alan Gilbert8f480de2014-01-30 10:20:31 +00001178 "-name string1[,process=string2][,debug-threads=on|off]\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001179 " set the name of the guest\n"
Roman Bolshakov479a5742018-12-17 23:26:01 +03001180 " string1 sets the window title and string2 the process name\n"
1181 " When debug-threads is enabled, individual threads are given a separate name\n"
Dr. David Alan Gilbert8f480de2014-01-30 10:20:31 +00001182 " NOTE: The thread names are for debugging and not a stable API.\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001183 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001184SRST
1185``-name name``
1186 Sets the name of the guest. This name will be displayed in the SDL
1187 window caption. The name will also be used for the VNC server. Also
1188 optionally set the top visible process name in Linux. Naming of
1189 individual threads can also be enabled on Linux to aid debugging.
1190ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001191
1192DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
1193 "-uuid %08x-%04x-%04x-%04x-%012x\n"
1194 " specify machine UUID\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001195SRST
1196``-uuid uuid``
1197 Set system UUID.
1198ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001199
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001200DEFHEADING()
1201
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02001202DEFHEADING(Block device options:)
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001203
Alex Bennée5af2b0f2022-08-22 17:56:08 +01001204SRST
1205The QEMU block device handling options have a long history and
1206have gone through several iterations as the feature set and complexity
1207of the block layer have grown. Many online guides to QEMU often
1208reference older and deprecated options, which can lead to confusion.
1209
Alex Bennéec1654c32023-04-24 10:22:37 +01001210The most explicit way to describe disks is to use a combination of
Alex Bennée5af2b0f2022-08-22 17:56:08 +01001211``-device`` to specify the hardware device and ``-blockdev`` to
1212describe the backend. The device defines what the guest sees and the
Alex Bennéec1654c32023-04-24 10:22:37 +01001213backend describes how QEMU handles the data. It is the only guaranteed
1214stable interface for describing block devices and as such is
1215recommended for management tools and scripting.
1216
1217The ``-drive`` option combines the device and backend into a single
1218command line option which is a more human friendly. There is however no
1219interface stability guarantee although some older board models still
1220need updating to work with the modern blockdev forms.
1221
1222Older options like ``-hda`` are essentially macros which expand into
1223``-drive`` options for various drive interfaces. The original forms
1224bake in a lot of assumptions from the days when QEMU was emulating a
1225legacy PC, they are not recommended for modern configurations.
Alex Bennée5af2b0f2022-08-22 17:56:08 +01001226
1227ERST
1228
blueswir15824d652009-03-28 06:44:27 +00001229DEF("fda", HAS_ARG, QEMU_OPTION_fda,
Blue Swirlad960902010-03-29 19:23:52 +00001230 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
1231DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001232SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00001233``-fda file``
1234 \
1235``-fdb file``
Thomas Huth923e9312020-11-16 15:47:36 +01001236 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in
1237 the System Emulation Users Guide).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001238ERST
blueswir15824d652009-03-28 06:44:27 +00001239
1240DEF("hda", HAS_ARG, QEMU_OPTION_hda,
Thomas Huthbcd8e242023-08-29 15:29:48 +02001241 "-hda/-hdb file use 'file' as hard disk 0/1 image\n", QEMU_ARCH_ALL)
Blue Swirlad960902010-03-29 19:23:52 +00001242DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00001243DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
Thomas Huthbcd8e242023-08-29 15:29:48 +02001244 "-hdc/-hdd file use 'file' as hard disk 2/3 image\n", QEMU_ARCH_ALL)
Blue Swirlad960902010-03-29 19:23:52 +00001245DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001246SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00001247``-hda file``
1248 \
1249``-hdb file``
1250 \
1251``-hdc file``
1252 \
1253``-hdd file``
Thomas Huthbcd8e242023-08-29 15:29:48 +02001254 Use file as hard disk 0, 1, 2 or 3 image on the default bus of the
1255 emulated machine (this is for example the IDE bus on most x86 machines,
1256 but it can also be SCSI, virtio or something else on other target
1257 architectures). See also the :ref:`disk images` chapter in the System
1258 Emulation Users Guide.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001259ERST
blueswir15824d652009-03-28 06:44:27 +00001260
1261DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
Thomas Huthbcd8e242023-08-29 15:29:48 +02001262 "-cdrom file use 'file' as CD-ROM image\n",
Blue Swirlad960902010-03-29 19:23:52 +00001263 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001264SRST
1265``-cdrom file``
Thomas Huthbcd8e242023-08-29 15:29:48 +02001266 Use file as CD-ROM image on the default bus of the emulated machine
1267 (which is IDE1 master on x86, so you cannot use ``-hdc`` and ``-cdrom``
1268 at the same time there). On systems that support it, you can use the
1269 host CD-ROM by using ``/dev/cdrom`` as filename.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001270ERST
blueswir15824d652009-03-28 06:44:27 +00001271
Markus Armbruster42e5f392017-02-28 22:27:07 +01001272DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
1273 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
1274 " [,cache.direct=on|off][,cache.no-flush=on|off]\n"
Kevin Wolfc9b749d2019-10-15 12:29:58 +02001275 " [,read-only=on|off][,auto-read-only=on|off]\n"
1276 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n"
Markus Armbruster42e5f392017-02-28 22:27:07 +01001277 " [,driver specific parameters...]\n"
1278 " configure a block backend\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001279SRST
1280``-blockdev option[,option[,option[,...]]]``
1281 Define a new block driver node. Some of the options apply to all
1282 block drivers, other options are only accepted for a specific block
1283 driver. See below for a list of generic options and options for the
1284 most common block drivers.
1285
1286 Options that expect a reference to another node (e.g. ``file``) can
1287 be given in two ways. Either you specify the node name of an already
1288 existing node (file=node-name), or you define a new node inline,
1289 adding options for the referenced node after a dot
1290 (file.filename=path,file.aio=native).
1291
1292 A block driver node created with ``-blockdev`` can be used for a
1293 guest device by specifying its node name for the ``drive`` property
1294 in a ``-device`` argument that defines a block device.
1295
1296 ``Valid options for any block driver node:``
1297 ``driver``
1298 Specifies the block driver to use for the given node.
1299
1300 ``node-name``
1301 This defines the name of the block driver node by which it
1302 will be referenced later. The name must be unique, i.e. it
1303 must not match the name of a different block driver node, or
1304 (if you use ``-drive`` as well) the ID of a drive.
1305
1306 If no node name is specified, it is automatically generated.
1307 The generated node name is not intended to be predictable
1308 and changes between QEMU invocations. For the top level, an
1309 explicit node name must be specified.
1310
1311 ``read-only``
1312 Open the node read-only. Guest write attempts will fail.
1313
1314 Note that some block drivers support only read-only access,
1315 either generally or in certain configurations. In this case,
1316 the default value ``read-only=off`` does not work and the
1317 option must be specified explicitly.
1318
1319 ``auto-read-only``
1320 If ``auto-read-only=on`` is set, QEMU may fall back to
1321 read-only usage even when ``read-only=off`` is requested, or
1322 even switch between modes as needed, e.g. depending on
1323 whether the image file is writable or whether a writing user
1324 is attached to the node.
1325
1326 ``force-share``
1327 Override the image locking system of QEMU by forcing the
1328 node to utilize weaker shared access for permissions where
1329 it would normally request exclusive access. When there is
1330 the potential for multiple instances to have the same file
1331 open (whether this invocation of QEMU is the first or the
1332 second instance), both instances must permit shared access
1333 for the second instance to succeed at opening the file.
1334
1335 Enabling ``force-share=on`` requires ``read-only=on``.
1336
1337 ``cache.direct``
1338 The host page cache can be avoided with ``cache.direct=on``.
1339 This will attempt to do disk IO directly to the guest's
1340 memory. QEMU may still perform an internal copy of the data.
1341
1342 ``cache.no-flush``
1343 In case you don't care about data integrity over host
1344 failures, you can use ``cache.no-flush=on``. This option
1345 tells QEMU that it never needs to write any data to the disk
1346 but can instead keep things in cache. If anything goes
1347 wrong, like your host losing power, the disk storage getting
1348 disconnected accidentally, etc. your image will most
1349 probably be rendered unusable.
1350
1351 ``discard=discard``
1352 discard is one of "ignore" (or "off") or "unmap" (or "on")
1353 and controls whether ``discard`` (also known as ``trim`` or
1354 ``unmap``) requests are ignored or passed to the filesystem.
1355 Some machine types may not support discard requests.
1356
1357 ``detect-zeroes=detect-zeroes``
1358 detect-zeroes is "off", "on" or "unmap" and enables the
1359 automatic conversion of plain zero writes by the OS to
1360 driver specific optimized zero write commands. You may even
1361 choose "unmap" if discard is set to "unmap" to allow a zero
1362 write to be converted to an ``unmap`` operation.
1363
1364 ``Driver-specific options for file``
1365 This is the protocol-level block driver for accessing regular
1366 files.
1367
1368 ``filename``
1369 The path to the image file in the local filesystem
1370
1371 ``aio``
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001372 Specifies the AIO backend (threads/native/io_uring,
1373 default: threads)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001374
1375 ``locking``
1376 Specifies whether the image file is protected with Linux OFD
1377 / POSIX locks. The default is to use the Linux Open File
1378 Descriptor API if available, otherwise no lock is applied.
1379 (auto/on/off, default: auto)
1380
1381 Example:
1382
1383 ::
1384
1385 -blockdev driver=file,node-name=disk,filename=disk.img
1386
1387 ``Driver-specific options for raw``
1388 This is the image format block driver for raw images. It is
1389 usually stacked on top of a protocol level block driver such as
1390 ``file``.
1391
1392 ``file``
1393 Reference to or definition of the data source block driver
1394 node (e.g. a ``file`` driver node)
1395
1396 Example 1:
1397
1398 ::
1399
1400 -blockdev driver=file,node-name=disk_file,filename=disk.img
1401 -blockdev driver=raw,node-name=disk,file=disk_file
1402
1403 Example 2:
1404
1405 ::
1406
1407 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
1408
1409 ``Driver-specific options for qcow2``
1410 This is the image format block driver for qcow2 images. It is
1411 usually stacked on top of a protocol level block driver such as
1412 ``file``.
1413
1414 ``file``
1415 Reference to or definition of the data source block driver
1416 node (e.g. a ``file`` driver node)
1417
1418 ``backing``
1419 Reference to or definition of the backing file block device
1420 (default is taken from the image file). It is allowed to
1421 pass ``null`` here in order to disable the default backing
1422 file.
1423
1424 ``lazy-refcounts``
1425 Whether to enable the lazy refcounts feature (on/off;
1426 default is taken from the image file)
1427
1428 ``cache-size``
1429 The maximum total size of the L2 table and refcount block
1430 caches in bytes (default: the sum of l2-cache-size and
1431 refcount-cache-size)
1432
1433 ``l2-cache-size``
1434 The maximum size of the L2 table cache in bytes (default: if
1435 cache-size is not specified - 32M on Linux platforms, and 8M
1436 on non-Linux platforms; otherwise, as large as possible
1437 within the cache-size, while permitting the requested or the
1438 minimal refcount cache size)
1439
1440 ``refcount-cache-size``
1441 The maximum size of the refcount block cache in bytes
1442 (default: 4 times the cluster size; or if cache-size is
1443 specified, the part of it which is not used for the L2
1444 cache)
1445
1446 ``cache-clean-interval``
1447 Clean unused entries in the L2 and refcount caches. The
1448 interval is in seconds. The default value is 600 on
1449 supporting platforms, and 0 on other platforms. Setting it
1450 to 0 disables this feature.
1451
1452 ``pass-discard-request``
1453 Whether discard requests to the qcow2 device should be
1454 forwarded to the data source (on/off; default: on if
1455 discard=unmap is specified, off otherwise)
1456
1457 ``pass-discard-snapshot``
1458 Whether discard requests for the data source should be
1459 issued when a snapshot operation (e.g. deleting a snapshot)
1460 frees clusters in the qcow2 file (on/off; default: on)
1461
1462 ``pass-discard-other``
1463 Whether discard requests for the data source should be
1464 issued on other occasions where a cluster gets freed
1465 (on/off; default: off)
1466
Jean-Louis Dupond42a28902023-06-05 10:45:24 +02001467 ``discard-no-unref``
Jean-Louis Dupondb2b10902023-10-03 14:52:37 +02001468 When enabled, data clusters will remain preallocated when they are
1469 no longer used, e.g. because they are discarded or converted to
1470 zero clusters. As usual, whether the old data is discarded or kept
1471 on the protocol level (i.e. in the image file) depends on the
1472 setting of the pass-discard-request option. Keeping the clusters
1473 preallocated prevents qcow2 fragmentation that would otherwise be
1474 caused by freeing and re-allocating them later. Besides potential
Jean-Louis Dupond42a28902023-06-05 10:45:24 +02001475 performance degradation, such fragmentation can lead to increased
1476 allocation of clusters past the end of the image file,
1477 resulting in image files whose file length can grow much larger
1478 than their guest disk size would suggest.
1479 If image file length is of concern (e.g. when storing qcow2
1480 images directly on block devices), you should consider enabling
1481 this option.
1482
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001483 ``overlap-check``
1484 Which overlap checks to perform for writes to the image
1485 (none/constant/cached/all; default: cached). For details or
1486 finer granularity control refer to the QAPI documentation of
1487 ``blockdev-add``.
1488
1489 Example 1:
1490
1491 ::
1492
1493 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
1494 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
1495
1496 Example 2:
1497
1498 ::
1499
1500 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
1501
1502 ``Driver-specific options for other drivers``
1503 Please refer to the QAPI documentation of the ``blockdev-add``
1504 QMP command.
1505ERST
Markus Armbruster42e5f392017-02-28 22:27:07 +01001506
blueswir15824d652009-03-28 06:44:27 +00001507DEF("drive", HAS_ARG, QEMU_OPTION_drive,
1508 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
Stefan Hajnoczi92196b22011-08-04 12:26:52 +01001509 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
Kevin Wolf572023f2018-06-13 11:01:30 +02001510 " [,snapshot=on|off][,rerror=ignore|stop|report]\n"
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001511 " [,werror=ignore|stop|report|enospc][,id=name]\n"
1512 " [,aio=threads|native|io_uring]\n"
Stefan Hajnoczifb0490f2011-11-17 13:40:32 +00001513 " [,readonly=on|off][,copy-on-read=on|off]\n"
Peter Lieven2f7133b2014-07-28 21:53:02 +02001514 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
Benoît Canet3e9fab62013-09-02 14:14:40 +02001515 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
1516 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
1517 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
1518 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
Benoît Canet2024c1d2013-09-02 14:14:41 +02001519 " [[,iops_size=is]]\n"
Alberto Garcia76f4afb2015-06-08 18:17:44 +02001520 " [[,group=g]]\n"
Blue Swirlad960902010-03-29 19:23:52 +00001521 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001522SRST
1523``-drive option[,option[,option[,...]]]``
1524 Define a new drive. This includes creating a block driver node (the
1525 backend) as well as a guest device, and is mostly a shortcut for
1526 defining the corresponding ``-blockdev`` and ``-device`` options.
1527
1528 ``-drive`` accepts all options that are accepted by ``-blockdev``.
1529 In addition, it knows the following options:
1530
1531 ``file=file``
Thomas Huth923e9312020-11-16 15:47:36 +01001532 This option defines which disk image (see the :ref:`disk images`
1533 chapter in the System Emulation Users Guide) to use with this drive.
1534 If the filename contains comma, you must double it (for instance,
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001535 "file=my,,file" to use file "my,file").
1536
1537 Special files such as iSCSI devices can be specified using
1538 protocol specific URLs. See the section for "Device URL Syntax"
1539 for more information.
1540
1541 ``if=interface``
1542 This option defines on which type on interface the drive is
1543 connected. Available types are: ide, scsi, sd, mtd, floppy,
1544 pflash, virtio, none.
1545
1546 ``bus=bus,unit=unit``
1547 These options define where is connected the drive by defining
1548 the bus number and the unit id.
1549
1550 ``index=index``
Laurent Vivier35aab302022-02-02 15:34:22 +01001551 This option defines where the drive is connected by using an
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001552 index in the list of available connectors of a given interface
1553 type.
1554
1555 ``media=media``
1556 This option defines the type of the media: disk or cdrom.
1557
1558 ``snapshot=snapshot``
1559 snapshot is "on" or "off" and controls snapshot mode for the
1560 given drive (see ``-snapshot``).
1561
1562 ``cache=cache``
1563 cache is "none", "writeback", "unsafe", "directsync" or
1564 "writethrough" and controls how the host cache is used to access
1565 block data. This is a shortcut that sets the ``cache.direct``
1566 and ``cache.no-flush`` options (as in ``-blockdev``), and
1567 additionally ``cache.writeback``, which provides a default for
1568 the ``write-cache`` option of block guest devices (as in
1569 ``-device``). The modes correspond to the following settings:
1570
Peter Maydell09ce5f22020-02-28 15:36:13 +00001571 ============= =============== ============ ==============
1572 \ cache.writeback cache.direct cache.no-flush
1573 ============= =============== ============ ==============
1574 writeback on off off
1575 none on on off
1576 writethrough off off off
1577 directsync off on off
1578 unsafe on off on
1579 ============= =============== ============ ==============
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001580
1581 The default mode is ``cache=writeback``.
1582
1583 ``aio=aio``
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001584 aio is "threads", "native", or "io_uring" and selects between pthread
1585 based disk I/O, native Linux AIO, or Linux io_uring API.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001586
1587 ``format=format``
1588 Specify which disk format will be used rather than detecting the
1589 format. Can be used to specify format=raw to avoid interpreting
1590 an untrusted format header.
1591
1592 ``werror=action,rerror=action``
1593 Specify which action to take on write and read errors. Valid
1594 actions are: "ignore" (ignore the error and try to continue),
1595 "stop" (pause QEMU), "report" (report the error to the guest),
1596 "enospc" (pause QEMU only if the host disk is full; report the
1597 error to the guest otherwise). The default setting is
1598 ``werror=enospc`` and ``rerror=report``.
1599
1600 ``copy-on-read=copy-on-read``
1601 copy-on-read is "on" or "off" and enables whether to copy read
1602 backing file sectors into the image file.
1603
1604 ``bps=b,bps_rd=r,bps_wr=w``
1605 Specify bandwidth throttling limits in bytes per second, either
1606 for all request types or for reads or writes only. Small values
1607 can lead to timeouts or hangs inside the guest. A safe minimum
1608 for disks is 2 MB/s.
1609
1610 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm``
1611 Specify bursts in bytes per second, either for all request types
1612 or for reads or writes only. Bursts allow the guest I/O to spike
1613 above the limit temporarily.
1614
1615 ``iops=i,iops_rd=r,iops_wr=w``
1616 Specify request rate limits in requests per second, either for
1617 all request types or for reads or writes only.
1618
1619 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm``
1620 Specify bursts in requests per second, either for all request
1621 types or for reads or writes only. Bursts allow the guest I/O to
1622 spike above the limit temporarily.
1623
1624 ``iops_size=is``
1625 Let every is bytes of a request count as a new request for iops
1626 throttling purposes. Use this option to prevent guests from
1627 circumventing iops limits by sending fewer but larger requests.
1628
1629 ``group=g``
1630 Join a throttling quota group with given name g. All drives that
1631 are members of the same group are accounted for together. Use
1632 this option to prevent guests from circumventing throttling
1633 limits by using many small disks instead of a single larger
1634 disk.
1635
1636 By default, the ``cache.writeback=on`` mode is used. It will report
1637 data writes as completed as soon as the data is present in the host
1638 page cache. This is safe as long as your guest OS makes sure to
1639 correctly flush disk caches where needed. If your guest OS does not
1640 handle volatile disk write caches correctly and your host crashes or
1641 loses power, then the guest may experience data corruption.
1642
1643 For such guests, you should consider using ``cache.writeback=off``.
1644 This means that the host page cache will be used to read and write
1645 data, but write notification will be sent to the guest only after
1646 QEMU has made sure to flush each write to the disk. Be aware that
1647 this has a major impact on performance.
1648
1649 When using the ``-snapshot`` option, unsafe caching is always used.
1650
1651 Copy-on-read avoids accessing the same backing file sectors
1652 repeatedly and is useful when the backing file is over a slow
1653 network. By default copy-on-read is off.
1654
1655 Instead of ``-cdrom`` you can use:
1656
1657 .. parsed-literal::
1658
1659 |qemu_system| -drive file=file,index=2,media=cdrom
1660
1661 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use:
1662
1663 .. parsed-literal::
1664
1665 |qemu_system| -drive file=file,index=0,media=disk
1666 |qemu_system| -drive file=file,index=1,media=disk
1667 |qemu_system| -drive file=file,index=2,media=disk
1668 |qemu_system| -drive file=file,index=3,media=disk
1669
1670 You can open an image using pre-opened file descriptors from an fd
1671 set:
1672
1673 .. parsed-literal::
1674
Laszlo Ersek353a06b2020-09-08 19:21:11 +02001675 |qemu_system| \\
1676 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\
1677 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001678 -drive file=/dev/fdset/2,index=0,media=disk
1679
1680 You can connect a CDROM to the slave of ide0:
1681
1682 .. parsed-literal::
1683
1684 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom
1685
1686 If you don't specify the "file=" argument, you define an empty
1687 drive:
1688
1689 .. parsed-literal::
1690
1691 |qemu_system_x86| -drive if=ide,index=1,media=cdrom
1692
1693 Instead of ``-fda``, ``-fdb``, you can use:
1694
1695 .. parsed-literal::
1696
1697 |qemu_system_x86| -drive file=file,index=0,if=floppy
1698 |qemu_system_x86| -drive file=file,index=1,if=floppy
1699
1700 By default, interface is "ide" and index is automatically
1701 incremented:
1702
1703 .. parsed-literal::
1704
John Snowa234ec32023-02-02 17:31:21 -05001705 |qemu_system_x86| -drive file=a -drive file=b
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001706
1707 is interpreted like:
1708
1709 .. parsed-literal::
1710
1711 |qemu_system_x86| -hda a -hdb b
1712ERST
blueswir15824d652009-03-28 06:44:27 +00001713
1714DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
Blue Swirlad960902010-03-29 19:23:52 +00001715 "-mtdblock file use 'file' as on-board Flash memory image\n",
1716 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001717SRST
1718``-mtdblock file``
1719 Use file as on-board Flash memory image.
1720ERST
blueswir15824d652009-03-28 06:44:27 +00001721
1722DEF("sd", HAS_ARG, QEMU_OPTION_sd,
Blue Swirlad960902010-03-29 19:23:52 +00001723 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001724SRST
1725``-sd file``
1726 Use file as SecureDigital card image.
1727ERST
blueswir15824d652009-03-28 06:44:27 +00001728
blueswir15824d652009-03-28 06:44:27 +00001729DEF("snapshot", 0, QEMU_OPTION_snapshot,
Blue Swirlad960902010-03-29 19:23:52 +00001730 "-snapshot write to temporary files instead of disk image files\n",
1731 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001732SRST
1733``-snapshot``
1734 Write to temporary files instead of disk image files. In this case,
1735 the raw disk image you use is not written back. You can however
Thomas Huth923e9312020-11-16 15:47:36 +01001736 force the write back by pressing C-a s (see the :ref:`disk images`
1737 chapter in the System Emulation Users Guide).
Alex Bennéec1654c32023-04-24 10:22:37 +01001738
1739 .. warning::
1740 snapshot is incompatible with ``-blockdev`` (instead use qemu-img
1741 to manually create snapshot images to attach to your blockdev).
1742 If you have mixed ``-blockdev`` and ``-drive`` declarations you
1743 can use the 'snapshot' property on your drive declarations
1744 instead of this global option.
1745
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001746ERST
blueswir15824d652009-03-28 06:44:27 +00001747
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301748DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
Greg Kurzb44a6b02019-05-17 17:34:49 +02001749 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n"
Paolo Bonzini991c1802020-11-13 03:10:52 -05001750 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n"
Pradeep Jagadeeshb8bbdb82017-02-28 10:31:46 +01001751 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1752 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1753 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1754 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
Greg Kurzb44a6b02019-05-17 17:34:49 +02001755 " [[,throttling.iops-size=is]]\n"
Paolo Bonzini991c1802020-11-13 03:10:52 -05001756 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly=on]\n"
1757 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly=on]\n"
Greg Kurzb44a6b02019-05-17 17:34:49 +02001758 "-fsdev synth,id=id\n",
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301759 QEMU_ARCH_ALL)
1760
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001761SRST
Paolo Bonzini991c1802020-11-13 03:10:52 -05001762``-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 +00001763 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001764``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly=on]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001765 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001766``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly=on]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001767 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001768``-fsdev synth,id=id[,readonly=on]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001769 Define a new file system device. Valid options are:
1770
1771 ``local``
1772 Accesses to the filesystem are done by QEMU.
1773
1774 ``proxy``
Christian Schoenebeck71d72ec2023-06-26 13:49:06 +02001775 Accesses to the filesystem are done by virtfs-proxy-helper(1). This
1776 option is deprecated (since QEMU 8.1) and will be removed in a future
1777 version of QEMU. Use ``local`` instead.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001778
1779 ``synth``
1780 Synthetic filesystem, only used by QTests.
1781
1782 ``id=id``
1783 Specifies identifier for this device.
1784
1785 ``path=path``
1786 Specifies the export path for the file system device. Files
1787 under this path will be available to the 9p client on the guest.
1788
1789 ``security_model=security_model``
1790 Specifies the security model to be used for this export path.
1791 Supported security models are "passthrough", "mapped-xattr",
1792 "mapped-file" and "none". In "passthrough" security model, files
1793 are stored using the same credentials as they are created on the
1794 guest. This requires QEMU to run as root. In "mapped-xattr"
1795 security model, some of the file attributes like uid, gid, mode
1796 bits and link target are stored as file attributes. For
1797 "mapped-file" these attributes are stored in the hidden
1798 .virtfs\_metadata directory. Directories exported by this
1799 security model cannot interact with other unix tools. "none"
1800 security model is same as passthrough except the sever won't
1801 report failures if it fails to set file attributes like
1802 ownership. Security model is mandatory only for local fsdriver.
1803 Other fsdrivers (like proxy) don't take security model as a
1804 parameter.
1805
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
1817 ``socket=socket``
1818 Enables proxy filesystem driver to use passed socket file for
1819 communicating with virtfs-proxy-helper(1).
1820
1821 ``sock_fd=sock_fd``
1822 Enables proxy filesystem driver to use passed socket descriptor
1823 for communicating with virtfs-proxy-helper(1). Usually a helper
1824 like libvirt will create socketpair and pass one of the fds as
1825 sock\_fd.
1826
1827 ``fmode=fmode``
1828 Specifies the default mode for newly created files on the host.
1829 Works only with security models "mapped-xattr" and
1830 "mapped-file".
1831
1832 ``dmode=dmode``
1833 Specifies the default mode for newly created directories on the
1834 host. Works only with security models "mapped-xattr" and
1835 "mapped-file".
1836
1837 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w``
1838 Specify bandwidth throttling limits in bytes per second, either
1839 for all request types or for reads or writes only.
1840
1841 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm``
1842 Specify bursts in bytes per second, either for all request types
1843 or for reads or writes only. Bursts allow the guest I/O to spike
1844 above the limit temporarily.
1845
1846 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w``
1847 Specify request rate limits in requests per second, either for
1848 all request types or for reads or writes only.
1849
1850 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm``
1851 Specify bursts in requests per second, either for all request
1852 types or for reads or writes only. Bursts allow the guest I/O to
1853 spike above the limit temporarily.
1854
1855 ``throttling.iops-size=is``
1856 Let every is bytes of a request count as a new request for iops
1857 throttling purposes.
1858
1859 -fsdev option is used along with -device driver "virtio-9p-...".
1860
1861``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag``
1862 Options for virtio-9p-... driver are:
1863
1864 ``type``
1865 Specifies the variant to be used. Supported values are "pci",
1866 "ccw" or "device", depending on the machine type.
1867
1868 ``fsdev=id``
1869 Specifies the id value specified along with -fsdev option.
1870
1871 ``mount_tag=mount_tag``
1872 Specifies the tag name to be used by the guest to mount this
1873 export point.
1874ERST
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301875
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301876DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
Greg Kurzb44a6b02019-05-17 17:34:49 +02001877 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n"
Paolo Bonzini991c1802020-11-13 03:10:52 -05001878 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n"
1879 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly=on]\n"
1880 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly=on]\n"
1881 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n",
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301882 QEMU_ARCH_ALL)
1883
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001884SRST
Paolo Bonzini991c1802020-11-13 03:10:52 -05001885``-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 +00001886 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001887``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly=on]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001888 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001889``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly=on]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001890 \
1891``-virtfs synth,mount_tag=mount_tag``
Christian Schoenebeck65abaa02020-05-14 08:06:43 +02001892 Define a new virtual filesystem device and expose it to the guest using
1893 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain
1894 directory on host is made directly accessible by guest as a pass-through
1895 file system by using the 9P network protocol for communication between
1896 host and guests, if desired even accessible, shared by several guests
Stefan Weil2cb40d42022-11-10 20:08:25 +01001897 simultaneously.
Christian Schoenebeck65abaa02020-05-14 08:06:43 +02001898
1899 Note that ``-virtfs`` is actually just a convenience shortcut for its
1900 generalized form ``-fsdev -device virtio-9p-pci``.
1901
1902 The general form of pass-through file system options are:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001903
1904 ``local``
1905 Accesses to the filesystem are done by QEMU.
1906
1907 ``proxy``
1908 Accesses to the filesystem are done by virtfs-proxy-helper(1).
Christian Schoenebeck71d72ec2023-06-26 13:49:06 +02001909 This option is deprecated (since QEMU 8.1) and will be removed in a
1910 future version of QEMU. Use ``local`` instead.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001911
1912 ``synth``
1913 Synthetic filesystem, only used by QTests.
1914
1915 ``id=id``
1916 Specifies identifier for the filesystem device
1917
1918 ``path=path``
1919 Specifies the export path for the file system device. Files
1920 under this path will be available to the 9p client on the guest.
1921
1922 ``security_model=security_model``
1923 Specifies the security model to be used for this export path.
1924 Supported security models are "passthrough", "mapped-xattr",
1925 "mapped-file" and "none". In "passthrough" security model, files
1926 are stored using the same credentials as they are created on the
1927 guest. This requires QEMU to run as root. In "mapped-xattr"
1928 security model, some of the file attributes like uid, gid, mode
1929 bits and link target are stored as file attributes. For
1930 "mapped-file" these attributes are stored in the hidden
1931 .virtfs\_metadata directory. Directories exported by this
1932 security model cannot interact with other unix tools. "none"
1933 security model is same as passthrough except the sever won't
1934 report failures if it fails to set file attributes like
1935 ownership. Security model is mandatory only for local fsdriver.
1936 Other fsdrivers (like proxy) don't take security model as a
1937 parameter.
1938
1939 ``writeout=writeout``
1940 This is an optional argument. The only supported value is
1941 "immediate". This means that host page cache will be used to
1942 read and write data but write notification will be sent to the
1943 guest only when the data has been reported as written by the
1944 storage subsystem.
1945
Paolo Bonzini991c1802020-11-13 03:10:52 -05001946 ``readonly=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001947 Enables exporting 9p share as a readonly mount for guests. By
1948 default read-write access is given.
1949
1950 ``socket=socket``
1951 Enables proxy filesystem driver to use passed socket file for
1952 communicating with virtfs-proxy-helper(1). Usually a helper like
1953 libvirt will create socketpair and pass one of the fds as
1954 sock\_fd.
1955
1956 ``sock_fd``
1957 Enables proxy filesystem driver to use passed 'sock\_fd' as the
1958 socket descriptor for interfacing with virtfs-proxy-helper(1).
1959
1960 ``fmode=fmode``
1961 Specifies the default mode for newly created files on the host.
1962 Works only with security models "mapped-xattr" and
1963 "mapped-file".
1964
1965 ``dmode=dmode``
1966 Specifies the default mode for newly created directories on the
1967 host. Works only with security models "mapped-xattr" and
1968 "mapped-file".
1969
1970 ``mount_tag=mount_tag``
1971 Specifies the tag name to be used by the guest to mount this
1972 export point.
1973
1974 ``multidevs=multidevs``
1975 Specifies how to deal with multiple devices being shared with a
1976 9p export. Supported behaviours are either "remap", "forbid" or
1977 "warn". The latter is the default behaviour on which virtfs 9p
1978 expects only one device to be shared with the same export, and
1979 if more than one device is shared and accessed via the same 9p
1980 export then only a warning message is logged (once) by qemu on
1981 host side. In order to avoid file ID collisions on guest you
1982 should either create a separate virtfs export for each device to
1983 be shared with guests (recommended way) or you might use "remap"
1984 instead which allows you to share multiple devices with only one
1985 export instead, which is achieved by remapping the original
1986 inode numbers from host to guest in a way that would prevent
1987 such collisions. Remapping inodes in such use cases is required
1988 because the original device IDs from host are never passed and
1989 exposed on guest. Instead all files of an export shared with
1990 virtfs always share the same device id on guest. So two files
1991 with identical inode numbers but from actually different devices
1992 on host would otherwise cause a file ID collision and hence
1993 potential misbehaviours on guest. "forbid" on the other hand
1994 assumes like "warn" that only one device is shared by the same
1995 export, however it will not only log a warning message but also
1996 deny access to additional devices on guest. Note though that
1997 "forbid" does currently not block all possible file access
1998 operations (e.g. readdir() would still return entries from other
1999 devices).
2000ERST
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05302001
Markus Armbruster61d70482017-10-02 16:03:03 +02002002DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
Daniel P. Berrangéc3b3a6c2022-12-01 04:25:05 -05002003 "-iscsi [user=user][,password=password][,password-secret=secret-id]\n"
2004 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE]\n"
Markus Armbruster61d70482017-10-02 16:03:03 +02002005 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2006 " [,timeout=timeout]\n"
2007 " iSCSI session parameters\n", QEMU_ARCH_ALL)
2008
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002009SRST
2010``-iscsi``
2011 Configure iSCSI session parameters.
2012ERST
Markus Armbruster44743142017-10-02 16:03:04 +02002013
blueswir15824d652009-03-28 06:44:27 +00002014DEFHEADING()
2015
Thomas Huthc2a34ab2021-03-10 18:33:23 +01002016DEFHEADING(USB convenience options:)
Markus Armbruster10adb8b2013-02-13 19:49:43 +01002017
2018DEF("usb", 0, QEMU_OPTION_usb,
Stefan Hajnoczi73f46fe2019-08-15 15:14:28 +01002019 "-usb enable on-board USB host controller (if not enabled by default)\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +01002020 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002021SRST
2022``-usb``
2023 Enable USB emulation on machine types with an on-board USB host
2024 controller (if not enabled by default). Note that on-board USB host
2025 controllers may not support USB 3.0. In this case
2026 ``-device qemu-xhci`` can be used instead on machines with PCI.
2027ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01002028
2029DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
2030 "-usbdevice name add the host or guest USB device 'name'\n",
2031 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002032SRST
2033``-usbdevice devname``
Thomas Huthc2a34ab2021-03-10 18:33:23 +01002034 Add the USB device devname, and enable an on-board USB controller
2035 if possible and necessary (just like it can be done via
2036 ``-machine usb=on``). Note that this option is mainly intended for
2037 the user's convenience only. More fine-grained control can be
2038 achieved by selecting a USB host controller (if necessary) and the
2039 desired USB device via the ``-device`` option instead. For example,
2040 instead of using ``-usbdevice mouse`` it is possible to use
2041 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse
2042 to a USB 3.0 controller instead (at least on machines that support
2043 PCI and do not have an USB controller enabled by default yet).
2044 For more details, see the chapter about
Thomas Huth923e9312020-11-16 15:47:36 +01002045 :ref:`Connecting USB devices` in the System Emulation Users Guide.
Thomas Huthc2a34ab2021-03-10 18:33:23 +01002046 Possible devices for devname are:
2047
2048 ``braille``
2049 Braille device. This will use BrlAPI to display the braille
2050 output on a real or fake device (i.e. it also creates a
2051 corresponding ``braille`` chardev automatically beside the
2052 ``usb-braille`` USB device).
2053
Thomas Huthc2a34ab2021-03-10 18:33:23 +01002054 ``keyboard``
2055 Standard USB keyboard. Will override the PS/2 keyboard (if present).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002056
2057 ``mouse``
2058 Virtual Mouse. This will override the PS/2 mouse emulation when
2059 activated.
2060
2061 ``tablet``
2062 Pointer device that uses absolute coordinates (like a
2063 touchscreen). This means QEMU is able to report the mouse
2064 position without having to grab the mouse. Also overrides the
2065 PS/2 mouse emulation when activated.
2066
Thomas Huthc2a34ab2021-03-10 18:33:23 +01002067 ``wacom-tablet``
2068 Wacom PenPartner USB tablet.
2069
2070
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002071ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01002072
Markus Armbruster10adb8b2013-02-13 19:49:43 +01002073DEFHEADING()
2074
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002075DEFHEADING(Display options:)
blueswir15824d652009-03-28 06:44:27 +00002076
Jes Sorensen1472a952011-03-16 13:33:31 +01002077DEF("display", HAS_ARG, QEMU_OPTION_display,
Thomas Huth88b40c62019-10-23 14:01:28 +02002078#if defined(CONFIG_SPICE)
Marc-André Lureaud8aec9d2019-02-21 12:07:03 +01002079 "-display spice-app[,gl=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02002080#endif
2081#if defined(CONFIG_SDL)
Thomas Hutha743d602022-05-19 17:56:23 +02002082 "-display sdl[,gl=on|core|es|off][,grab-mod=<mod>][,show-cursor=on|off]\n"
2083 " [,window-close=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02002084#endif
Robert Hof04ec5a2016-07-26 18:17:11 +08002085#if defined(CONFIG_GTK)
Thomas Huth95f439b2021-06-30 18:32:31 +02002086 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n"
Felix xq Queißnerc34a9332022-07-12 15:37:53 +02002087 " [,show-tabs=on|off][,show-cursor=on|off][,window-close=on|off]\n"
BALATON Zoltane26c9402024-02-09 01:05:06 +01002088 " [,show-menubar=on|off][,zoom-to-fit=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02002089#endif
2090#if defined(CONFIG_VNC)
2091 "-display vnc=<display>[,<optargs>]\n"
2092#endif
2093#if defined(CONFIG_CURSES)
2094 "-display curses[,charset=<encoding>]\n"
2095#endif
Gustavo Noronha Silvaf844cdb2022-03-06 21:11:18 +09002096#if defined(CONFIG_COCOA)
Gustavo Noronha Silva4797adc2022-03-06 21:11:19 +09002097 "-display cocoa[,full-grab=on|off][,swap-opt-cmd=on|off]\n"
Akihiko Odaki9ab87152023-12-14 15:31:35 +09002098 " [,show-cursor=on|off][,left-command-key=on|off]\n"
Akihiko Odakid502dfc2023-12-14 15:31:36 +09002099 " [,full-screen=on|off][,zoom-to-fit=on|off]\n"
Gustavo Noronha Silvaf844cdb2022-03-06 21:11:18 +09002100#endif
Thomas Huth88b40c62019-10-23 14:01:28 +02002101#if defined(CONFIG_OPENGL)
2102 "-display egl-headless[,rendernode=<file>]\n"
2103#endif
Marc-André Lureau142ca622021-07-15 11:53:53 +04002104#if defined(CONFIG_DBUS_DISPLAY)
2105 "-display dbus[,addr=<dbusaddr>]\n"
2106 " [,gl=on|core|es|off][,rendernode=<file>]\n"
2107#endif
Thomas Huth88b40c62019-10-23 14:01:28 +02002108 "-display none\n"
2109 " select display backend type\n"
2110 " The default display is equivalent to\n "
2111#if defined(CONFIG_GTK)
2112 "\"-display gtk\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002113#elif defined(CONFIG_SDL)
Thomas Huth88b40c62019-10-23 14:01:28 +02002114 "\"-display sdl\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002115#elif defined(CONFIG_COCOA)
Thomas Huth88b40c62019-10-23 14:01:28 +02002116 "\"-display cocoa\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002117#elif defined(CONFIG_VNC)
Thomas Huth88b40c62019-10-23 14:01:28 +02002118 "\"-vnc localhost:0,to=99,id=default\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002119#else
Thomas Huth88b40c62019-10-23 14:01:28 +02002120 "\"-display none\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002121#endif
2122 , QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002123SRST
2124``-display type``
Thomas Huth707d93d2022-05-19 17:56:25 +02002125 Select type of display to use. Use ``-display help`` to list the available
2126 display types. Valid values for type are
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002127
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002128 ``spice-app[,gl=on|off]``
2129 Start QEMU as a Spice server and launch the default Spice client
2130 application. The Spice server will redirect the serial consoles
2131 and QEMU monitors. (Since 4.0)
2132
Marc-André Lureau142ca622021-07-15 11:53:53 +04002133 ``dbus``
2134 Export the display over D-Bus interfaces. (Since 7.0)
2135
2136 The connection is registered with the "org.qemu" name (and queued when
2137 already owned).
2138
2139 ``addr=<dbusaddr>`` : D-Bus bus address to connect to.
2140
Marc-André Lureau99997822021-10-10 00:16:57 +04002141 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``.
2142
2143 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface
2144 will share framebuffers with DMABUF file descriptors).
Marc-André Lureau142ca622021-07-15 11:53:53 +04002145
Thomas Huth95f439b2021-06-30 18:32:31 +02002146 ``sdl``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002147 Display video output via SDL (usually in a separate graphics
2148 window; see the SDL documentation for other possibilities).
Thomas Huth95f439b2021-06-30 18:32:31 +02002149 Valid parameters are:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002150
Thomas Huth8e8e8442021-08-25 11:20:21 +02002151 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling
John Snow450e0f22021-10-04 17:52:36 -04002152 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be
2153 either ``lshift-lctrl-lalt`` or ``rctrl``.
Thomas Huth8e8e8442021-08-25 11:20:21 +02002154
Thomas Huth95f439b2021-06-30 18:32:31 +02002155 ``gl=on|off|core|es`` : Use OpenGL for displaying
2156
2157 ``show-cursor=on|off`` : Force showing the mouse cursor
2158
2159 ``window-close=on|off`` : Allow to quit qemu with window close button
2160
2161 ``gtk``
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002162 Display video output in a GTK window. This interface provides
2163 drop-down menus and other UI elements to configure and control
Thomas Huth95f439b2021-06-30 18:32:31 +02002164 the VM during runtime. Valid parameters are:
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002165
Thomas Huth95f439b2021-06-30 18:32:31 +02002166 ``full-screen=on|off`` : Start in fullscreen mode
2167
2168 ``gl=on|off`` : Use OpenGL for displaying
2169
2170 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover
2171
Felix xq Queißnerc34a9332022-07-12 15:37:53 +02002172 ``show-tabs=on|off`` : Display the tab bar for switching between the
2173 various graphical interfaces (e.g. VGA and
2174 virtual console character devices) by default.
2175
Thomas Huth95f439b2021-06-30 18:32:31 +02002176 ``show-cursor=on|off`` : Force showing the mouse cursor
2177
2178 ``window-close=on|off`` : Allow to quit qemu with window close button
2179
Bryce Millsdbccb1a2022-10-11 13:58:21 +00002180 ``show-menubar=on|off`` : Display the main window menubar, defaults to "on"
2181
Jan Kratochvilc35d9372023-06-28 18:23:36 +08002182 ``zoom-to-fit=on|off`` : Expand video output to the window size,
2183 defaults to "off"
2184
Thomas Huth95f439b2021-06-30 18:32:31 +02002185 ``curses[,charset=<encoding>]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002186 Display video output via curses. For graphics device models
2187 which support a text mode, QEMU can display this output using a
2188 curses/ncurses interface. Nothing is displayed when the graphics
2189 device is in graphical mode or if the graphics device does not
2190 support a text mode. Generally only the VGA device models
2191 support text mode. The font charset used by the guest can be
2192 specified with the ``charset`` option, for example
2193 ``charset=CP850`` for IBM CP850 encoding. The default is
2194 ``CP437``.
2195
Carwyn Ellis48941a52022-01-02 17:41:52 +00002196 ``cocoa``
2197 Display video output in a Cocoa window. Mac only. This interface
2198 provides drop-down menus and other UI elements to configure and
2199 control the VM during runtime. Valid parameters are:
2200
Akihiko Odakid502dfc2023-12-14 15:31:36 +09002201 ``full-grab=on|off`` : Capture all key presses, including system combos.
2202 This requires accessibility permissions, since it
2203 performs a global grab on key events.
2204 (default: off) See
2205 https://support.apple.com/en-in/guide/mac-help/mh32356/mac
2206
2207 ``swap-opt-cmd=on|off`` : Swap the Option and Command keys so that their
2208 key codes match their position on non-Mac
2209 keyboards and you can use Meta/Super and Alt
2210 where you expect them. (default: off)
2211
Carwyn Ellis48941a52022-01-02 17:41:52 +00002212 ``show-cursor=on|off`` : Force showing the mouse cursor
2213
2214 ``left-command-key=on|off`` : Disable forwarding left command key to host
2215
Akihiko Odakid502dfc2023-12-14 15:31:36 +09002216 ``full-screen=on|off`` : Start in fullscreen mode
2217
2218 ``zoom-to-fit=on|off`` : Expand video output to the window size,
2219 defaults to "off"
2220
Thomas Huth95f439b2021-06-30 18:32:31 +02002221 ``egl-headless[,rendernode=<file>]``
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002222 Offload all OpenGL operations to a local DRI device. For any
2223 graphical display, this display needs to be paired with either
2224 VNC or SPICE displays.
2225
Thomas Huth95f439b2021-06-30 18:32:31 +02002226 ``vnc=<display>``
2227 Start a VNC server on display <display>
2228
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002229 ``none``
2230 Do not display video output. The guest will still see an
2231 emulated graphics card, but its output will not be displayed to
2232 the QEMU user. This option differs from the -nographic option in
2233 that it only affects what is done with video output; -nographic
2234 also changes the destination of the serial and parallel port
2235 data.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002236ERST
Jes Sorensen1472a952011-03-16 13:33:31 +01002237
blueswir15824d652009-03-28 06:44:27 +00002238DEF("nographic", 0, QEMU_OPTION_nographic,
Blue Swirlad960902010-03-29 19:23:52 +00002239 "-nographic disable graphical output and redirect serial I/Os to console\n",
2240 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002241SRST
2242``-nographic``
2243 Normally, if QEMU is compiled with graphical window support, it
2244 displays output such as guest graphics, guest console, and the QEMU
2245 monitor in a window. With this option, you can totally disable
2246 graphical output so that QEMU is a simple command line application.
2247 The emulated serial port is redirected on the console and muxed with
2248 the monitor (unless redirected elsewhere explicitly). Therefore, you
2249 can still use QEMU to debug a Linux kernel with a serial console.
2250 Use C-a h for help on switching between the console and monitor.
2251ERST
blueswir15824d652009-03-28 06:44:27 +00002252
Marc-André Lureau5324e3e2021-09-09 12:44:11 +04002253#ifdef CONFIG_SPICE
Gerd Hoffmann29b00402010-03-11 11:13:27 -03002254DEF("spice", HAS_ARG, QEMU_OPTION_spice,
Yonit Halperin27af7782012-08-21 13:54:20 +03002255 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
2256 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
2257 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002258 " [,x509-dh-key-file=<file>][,addr=addr]\n"
2259 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n"
Yonit Halperin27af7782012-08-21 13:54:20 +03002260 " [,tls-ciphers=<list>]\n"
2261 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
2262 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
Daniel P. Berrangé99522f62021-03-11 11:43:42 +00002263 " [,sasl=on|off][,disable-ticketing=on|off]\n"
Daniel P. Berrangé36debaf2022-12-01 04:22:11 -05002264 " [,password-secret=<secret-id>]\n"
Yonit Halperin27af7782012-08-21 13:54:20 +03002265 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
2266 " [,jpeg-wan-compression=[auto|never|always]]\n"
2267 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002268 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n"
2269 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n"
Hans de Goede5ad24e52013-06-08 15:37:27 +02002270 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
Marc-André Lureau7b525502017-02-12 15:21:18 +04002271 " [,gl=[on|off]][,rendernode=<file>]\n"
Thomas Hutha635bcf2023-07-03 09:56:46 +02002272 " enable spice\n"
2273 " at least one of {port, tls-port} is mandatory\n",
Yonit Halperin27af7782012-08-21 13:54:20 +03002274 QEMU_ARCH_ALL)
Marc-André Lureau5324e3e2021-09-09 12:44:11 +04002275#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002276SRST
2277``-spice option[,option[,...]]``
2278 Enable the spice remote desktop protocol. Valid options are
2279
2280 ``port=<nr>``
2281 Set the TCP port spice is listening on for plaintext channels.
2282
2283 ``addr=<addr>``
2284 Set the IP address spice is listening on. Default is any
2285 address.
2286
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002287 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002288 Force using the specified IP version.
2289
Daniel P. Berrangé99522f62021-03-11 11:43:42 +00002290 ``password-secret=<secret-id>``
2291 Set the ID of the ``secret`` object containing the password
2292 you need to authenticate.
2293
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002294 ``sasl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002295 Require that the client use SASL to authenticate with the spice.
2296 The exact choice of authentication method used is controlled
2297 from the system / user's SASL configuration file for the 'qemu'
2298 service. This is typically found in /etc/sasl2/qemu.conf. If
2299 running QEMU as an unprivileged user, an environment variable
2300 SASL\_CONF\_PATH can be used to make it search alternate
2301 locations for the service config. While some SASL auth methods
2302 can also provide data encryption (eg GSSAPI), it is recommended
2303 that SASL always be combined with the 'tls' and 'x509' settings
2304 to enable use of SSL and server certificates. This ensures a
2305 data encryption preventing compromise of authentication
2306 credentials.
2307
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002308 ``disable-ticketing=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002309 Allow client connects without authentication.
2310
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002311 ``disable-copy-paste=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002312 Disable copy paste between the client and the guest.
2313
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002314 ``disable-agent-file-xfer=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002315 Disable spice-vdagent based file-xfer between the client and the
2316 guest.
2317
2318 ``tls-port=<nr>``
2319 Set the TCP port spice is listening on for encrypted channels.
2320
2321 ``x509-dir=<dir>``
2322 Set the x509 file directory. Expects same filenames as -vnc
2323 $display,x509=$dir
2324
2325 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>``
2326 The x509 file names can also be configured individually.
2327
2328 ``tls-ciphers=<list>``
2329 Specify which ciphers to use.
2330
2331 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]``
2332 Force specific channel to be used with or without TLS
2333 encryption. The options can be specified multiple times to
2334 configure multiple channels. The special name "default" can be
2335 used to set the default mode. For channels which are not
2336 explicitly forced into one mode the spice client is allowed to
2337 pick tls/plaintext as he pleases.
2338
2339 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]``
2340 Configure image compression (lossless). Default is auto\_glz.
2341
2342 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]``
2343 Configure wan image compression (lossy for slow links). Default
2344 is auto.
2345
2346 ``streaming-video=[off|all|filter]``
2347 Configure video stream detection. Default is off.
2348
2349 ``agent-mouse=[on|off]``
2350 Enable/disable passing mouse events via vdagent. Default is on.
2351
2352 ``playback-compression=[on|off]``
2353 Enable/disable audio stream compression (using celt 0.5.1).
2354 Default is on.
2355
2356 ``seamless-migration=[on|off]``
2357 Enable/disable spice seamless migration. Default is off.
2358
2359 ``gl=[on|off]``
2360 Enable/disable OpenGL context. Default is off.
2361
2362 ``rendernode=<file>``
2363 DRM render node for OpenGL rendering. If not specified, it will
2364 pick the first available. (Since 2.9)
2365ERST
Gerd Hoffmann29b00402010-03-11 11:13:27 -03002366
blueswir15824d652009-03-28 06:44:27 +00002367DEF("portrait", 0, QEMU_OPTION_portrait,
Blue Swirlad960902010-03-29 19:23:52 +00002368 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
2369 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002370SRST
2371``-portrait``
2372 Rotate graphical output 90 deg left (only PXA LCD).
2373ERST
blueswir15824d652009-03-28 06:44:27 +00002374
Vasily Khoruzhick93128052011-06-17 13:04:36 +03002375DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
2376 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
2377 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002378SRST
2379``-rotate deg``
2380 Rotate graphical output some deg left (only PXA LCD).
2381ERST
Vasily Khoruzhick93128052011-06-17 13:04:36 +03002382
blueswir15824d652009-03-28 06:44:27 +00002383DEF("vga", HAS_ARG, QEMU_OPTION_vga,
Gerd Hoffmanna94f0c52014-09-10 14:28:48 +02002384 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
Blue Swirlad960902010-03-29 19:23:52 +00002385 " select video card type\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002386SRST
2387``-vga type``
2388 Select type of VGA card to emulate. Valid values for type are
2389
2390 ``cirrus``
2391 Cirrus Logic GD5446 Video card. All Windows versions starting
2392 from Windows 95 should recognize and use this graphic card. For
2393 optimal performances, use 16 bit color depth in the guest and
2394 the host OS. (This card was the default before QEMU 2.2)
2395
2396 ``std``
2397 Standard VGA card with Bochs VBE extensions. If your guest OS
2398 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if
2399 you want to use high resolution modes (>= 1280x1024x16) then you
2400 should use this option. (This card is the default since QEMU
2401 2.2)
2402
2403 ``vmware``
2404 VMWare SVGA-II compatible adapter. Use it if you have
2405 sufficiently recent XFree86/XOrg server or Windows guest with a
2406 driver for this card.
2407
2408 ``qxl``
2409 QXL paravirtual graphic card. It is VGA compatible (including
2410 VESA 2.0 VBE support). Works best with qxl guest drivers
2411 installed though. Recommended choice when using the spice
2412 protocol.
2413
2414 ``tcx``
2415 (sun4m only) Sun TCX framebuffer. This is the default
2416 framebuffer for sun4m machines and offers both 8-bit and 24-bit
2417 colour depths at a fixed resolution of 1024x768.
2418
2419 ``cg3``
2420 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit
2421 framebuffer for sun4m machines available in both 1024x768
2422 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people
2423 wishing to run older Solaris versions.
2424
2425 ``virtio``
2426 Virtio VGA card.
2427
2428 ``none``
2429 Disable VGA card.
2430ERST
blueswir15824d652009-03-28 06:44:27 +00002431
2432DEF("full-screen", 0, QEMU_OPTION_full_screen,
Blue Swirlad960902010-03-29 19:23:52 +00002433 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002434SRST
2435``-full-screen``
2436 Start in full screen.
2437ERST
blueswir15824d652009-03-28 06:44:27 +00002438
John Snow60f9a4e2020-02-04 11:56:38 -05002439DEF("g", HAS_ARG, QEMU_OPTION_g ,
Blue Swirlad960902010-03-29 19:23:52 +00002440 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
Laurent Vivier8ac919a2019-10-26 18:45:43 +02002441 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002442SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00002443``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002444 Set the initial graphical resolution and depth (PPC, SPARC only).
2445
2446 For PPC the default is 800x600x32.
2447
2448 For SPARC with the TCX graphics device, the default is 1024x768x8
2449 with the option of 1024x768x24. For cgthree, the default is
2450 1024x768x8 with the option of 1152x900x8 for people who wish to use
2451 OBP.
2452ERST
blueswir15824d652009-03-28 06:44:27 +00002453
Marc-André Lureau62611642023-10-25 17:05:08 +04002454#ifdef CONFIG_VNC
blueswir15824d652009-03-28 06:44:27 +00002455DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
Robert Hof04ec5a2016-07-26 18:17:11 +08002456 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
Marc-André Lureau62611642023-10-25 17:05:08 +04002457#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002458SRST
2459``-vnc display[,option[,option[,...]]]``
2460 Normally, if QEMU is compiled with graphical window support, it
2461 displays output such as guest graphics, guest console, and the QEMU
2462 monitor in a window. With this option, you can have QEMU listen on
2463 VNC display display and redirect the VGA display over the VNC
2464 session. It is very useful to enable the usb tablet device when
2465 using this option (option ``-device usb-tablet``). When using the
2466 VNC display, you must use the ``-k`` parameter to set the keyboard
2467 layout if you are not using en-us. Valid syntax for the display is
2468
2469 ``to=L``
2470 With this option, QEMU will try next available VNC displays,
Manos Pitsidianakis835f3642024-02-20 10:52:23 +02002471 until the number L, if the originally defined "-vnc display" is
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002472 not available, e.g. port 5900+display is already used by another
2473 application. By default, to=0.
2474
2475 ``host:d``
2476 TCP connections will only be allowed from host on display d. By
2477 convention the TCP port is 5900+d. Optionally, host can be
2478 omitted in which case the server will accept connections from
2479 any host.
2480
2481 ``unix:path``
2482 Connections will be allowed over UNIX domain sockets where path
2483 is the location of a unix socket to listen for connections on.
2484
2485 ``none``
2486 VNC is initialized but not started. The monitor ``change``
2487 command can be used to later start the VNC server.
2488
2489 Following the display value there may be one or more option flags
2490 separated by commas. Valid options are
2491
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002492 ``reverse=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002493 Connect to a listening VNC client via a "reverse" connection.
2494 The client is specified by the display. For reverse network
2495 connections (host:d,``reverse``), the d argument is a TCP port
2496 number, not a display number.
2497
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002498 ``websocket=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002499 Opens an additional TCP listening port dedicated to VNC
2500 Websocket connections. If a bare websocket option is given, the
2501 Websocket port is 5700+display. An alternative port can be
2502 specified with the syntax ``websocket``\ =port.
2503
2504 If host is specified connections will only be allowed from this
2505 host. It is possible to control the websocket listen address
2506 independently, using the syntax ``websocket``\ =host:port.
2507
2508 If no TLS credentials are provided, the websocket connection
2509 runs in unencrypted mode. If TLS credentials are provided, the
2510 websocket connection requires encrypted client connections.
2511
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002512 ``password=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002513 Require that password based authentication is used for client
2514 connections.
2515
2516 The password must be set separately using the ``set_password``
Thomas Huth923e9312020-11-16 15:47:36 +01002517 command in the :ref:`QEMU monitor`. The
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002518 syntax to change your password is:
2519 ``set_password <protocol> <password>`` where <protocol> could be
2520 either "vnc" or "spice".
2521
2522 If you would like to change <protocol> password expiration, you
2523 should use ``expire_password <protocol> <expiration-time>``
2524 where expiration time could be one of the following options:
2525 now, never, +seconds or UNIX time of expiration, e.g. +60 to
2526 make password expire in 60 seconds, or 1335196800 to make
2527 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for
2528 this date and time).
2529
2530 You can also use keywords "now" or "never" for the expiration
2531 time to allow <protocol> password to expire immediately or never
2532 expire.
2533
Daniel P. Berrangé6c6840e2021-03-11 11:43:41 +00002534 ``password-secret=<secret-id>``
2535 Require that password based authentication is used for client
2536 connections, using the password provided by the ``secret``
2537 object identified by ``secret-id``.
2538
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002539 ``tls-creds=ID``
2540 Provides the ID of a set of TLS credentials to use to secure the
2541 VNC server. They will apply to both the normal VNC server socket
2542 and the websocket socket (if enabled). Setting TLS credentials
2543 will cause the VNC server socket to enable the VeNCrypt auth
2544 mechanism. The credentials should have been previously created
2545 using the ``-object tls-creds`` argument.
2546
2547 ``tls-authz=ID``
2548 Provides the ID of the QAuthZ authorization object against which
2549 the client's x509 distinguished name will validated. This object
2550 is only resolved at time of use, so can be deleted and recreated
2551 on the fly while the VNC server is active. If missing, it will
2552 default to denying access.
2553
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002554 ``sasl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002555 Require that the client use SASL to authenticate with the VNC
2556 server. The exact choice of authentication method used is
2557 controlled from the system / user's SASL configuration file for
2558 the 'qemu' service. This is typically found in
2559 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user,
2560 an environment variable SASL\_CONF\_PATH can be used to make it
2561 search alternate locations for the service config. While some
2562 SASL auth methods can also provide data encryption (eg GSSAPI),
2563 it is recommended that SASL always be combined with the 'tls'
2564 and 'x509' settings to enable use of SSL and server
2565 certificates. This ensures a data encryption preventing
2566 compromise of authentication credentials. See the
Thomas Huth923e9312020-11-16 15:47:36 +01002567 :ref:`VNC security` section in the System Emulation Users Guide
2568 for details on using SASL authentication.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002569
2570 ``sasl-authz=ID``
2571 Provides the ID of the QAuthZ authorization object against which
2572 the client's SASL username will validated. This object is only
2573 resolved at time of use, so can be deleted and recreated on the
2574 fly while the VNC server is active. If missing, it will default
2575 to denying access.
2576
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002577 ``acl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002578 Legacy method for enabling authorization of clients against the
2579 x509 distinguished name and SASL username. It results in the
2580 creation of two ``authz-list`` objects with IDs of
2581 ``vnc.username`` and ``vnc.x509dname``. The rules for these
2582 objects must be configured with the HMP ACL commands.
2583
2584 This option is deprecated and should no longer be used. The new
2585 ``sasl-authz`` and ``tls-authz`` options are a replacement.
2586
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002587 ``lossy=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002588 Enable lossy compression methods (gradient, JPEG, ...). If this
2589 option is set, VNC client may receive lossy framebuffer updates
2590 depending on its encoding settings. Enabling this option can
2591 save a lot of bandwidth at the expense of quality.
2592
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002593 ``non-adaptive=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002594 Disable adaptive encodings. Adaptive encodings are enabled by
2595 default. An adaptive encoding will try to detect frequently
2596 updated screen regions, and send updates in these regions using
2597 a lossy encoding (like JPEG). This can be really helpful to save
2598 bandwidth when playing videos. Disabling adaptive encodings
2599 restores the original static behavior of encodings like Tight.
2600
2601 ``share=[allow-exclusive|force-shared|ignore]``
2602 Set display sharing policy. 'allow-exclusive' allows clients to
2603 ask for exclusive access. As suggested by the rfb spec this is
2604 implemented by dropping other connections. Connecting multiple
2605 clients in parallel requires all clients asking for a shared
2606 session (vncviewer: -shared switch). This is the default.
2607 'force-shared' disables exclusive client access. Useful for
2608 shared desktop sessions, where you don't want someone forgetting
2609 specify -shared disconnect everybody else. 'ignore' completely
2610 ignores the shared flag and allows everybody connect
2611 unconditionally. Doesn't conform to the rfb spec but is
2612 traditional QEMU behavior.
2613
2614 ``key-delay-ms``
2615 Set keyboard delay, for key down and key up events, in
2616 milliseconds. Default is 10. Keyboards are low-bandwidth
2617 devices, so this slowdown can help the device and guest to keep
2618 up and not lose events in case events are arriving in bulk.
2619 Possible causes for the latter are flaky network connections, or
2620 scripts for automated testing.
2621
2622 ``audiodev=audiodev``
2623 Use the specified audiodev when the VNC client requests audio
2624 transmission. When not using an -audiodev argument, this option
2625 must be omitted, otherwise is must be present and specify a
2626 valid audiodev.
Daniel P. Berrangé7b5fa0b2020-12-11 16:08:25 +00002627
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002628 ``power-control=on|off``
Daniel P. Berrangé7b5fa0b2020-12-11 16:08:25 +00002629 Permit the remote client to issue shutdown, reboot or reset power
2630 control requests.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002631ERST
blueswir15824d652009-03-28 06:44:27 +00002632
Michael Ellermana3adb7a2011-12-19 17:19:31 +11002633ARCHHEADING(, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002634
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002635ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002636
blueswir15824d652009-03-28 06:44:27 +00002637DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
Blue Swirlad960902010-03-29 19:23:52 +00002638 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
2639 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002640SRST
2641``-win2k-hack``
2642 Use it when installing Windows 2000 to avoid a disk full bug. After
2643 Windows 2000 is installed, you no longer need this option (this
2644 option slows down the IDE transfers).
2645ERST
blueswir15824d652009-03-28 06:44:27 +00002646
blueswir15824d652009-03-28 06:44:27 +00002647DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
Blue Swirlad960902010-03-29 19:23:52 +00002648 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
2649 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002650SRST
2651``-no-fd-bootchk``
2652 Disable boot signature checking for floppy disks in BIOS. May be
2653 needed to boot from old floppy disks.
2654ERST
blueswir15824d652009-03-28 06:44:27 +00002655
blueswir15824d652009-03-28 06:44:27 +00002656DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
Michael Tokarev104bf022011-05-12 18:44:17 +04002657 "-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 +00002658 " ACPI table description\n", QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002659SRST
2660``-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]...]``
2661 Add ACPI table with specified header fields and context from
2662 specified files. For file=, take whole ACPI table from the specified
2663 files, including all ACPI headers (possible overridden by other
2664 options). For data=, only data portion of the table is used, all
2665 header information is specified in the command line. If a SLIC table
2666 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id
2667 fields will override the same in the RSDT and the FADT (a.k.a.
2668 FACP), in order to ensure the field matches required by the
2669 Microsoft SLIC spec and the ACPI spec.
2670ERST
blueswir15824d652009-03-28 06:44:27 +00002671
aliguorib6f6e3d2009-04-17 18:59:56 +00002672DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
2673 "-smbios file=binary\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002674 " load SMBIOS entry from binary file\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002675 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
2676 " [,uefi=on|off]\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002677 " specify SMBIOS type 0 fields\n"
aliguorib6f6e3d2009-04-17 18:59:56 +00002678 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2679 " [,uuid=uuid][,sku=str][,family=str]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002680 " specify SMBIOS type 1 fields\n"
2681 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2682 " [,asset=str][,location=str]\n"
2683 " specify SMBIOS type 2 fields\n"
2684 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
2685 " [,sku=str]\n"
2686 " specify SMBIOS type 3 fields\n"
2687 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
Ying Fangc906e032020-08-06 11:56:33 +08002688 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n"
Heinrich Schuchardtb5831d72024-01-23 19:42:26 +01002689 " [,processor-family=%d,processor-id=%d]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002690 " specify SMBIOS type 4 fields\n"
Hal Martinfd8caa22022-08-12 15:51:53 +02002691 "-smbios type=8[,external_reference=str][,internal_reference=str][,connector_type=%d][,port_type=%d]\n"
2692 " specify SMBIOS type 8 fields\n"
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002693 "-smbios type=11[,value=str][,path=filename]\n"
2694 " specify SMBIOS type 11 fields\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002695 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
Gabriel L. Somlo3ebd6cc2015-03-11 13:58:01 -04002696 " [,asset=str][,part=str][,speed=%d]\n"
Vincent Bernat05dfb442021-04-01 19:11:38 +02002697 " specify SMBIOS type 17 fields\n"
2698 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n"
2699 " specify SMBIOS type 41 fields\n",
Heinrich Schuchardte2ff0de2024-01-23 19:42:29 +01002700 QEMU_ARCH_I386 | QEMU_ARCH_ARM | QEMU_ARCH_LOONGARCH | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002701SRST
2702``-smbios file=binary``
2703 Load SMBIOS entry from binary file.
2704
2705``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]``
2706 Specify SMBIOS type 0 fields
2707
2708``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]``
2709 Specify SMBIOS type 1 fields
2710
2711``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]``
2712 Specify SMBIOS type 2 fields
2713
2714``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]``
2715 Specify SMBIOS type 3 fields
2716
Heinrich Schuchardtb5831d72024-01-23 19:42:26 +01002717``-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 +00002718 Specify SMBIOS type 4 fields
2719
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002720``-smbios type=11[,value=str][,path=filename]``
2721 Specify SMBIOS type 11 fields
2722
2723 This argument can be repeated multiple times, and values are added in the order they are parsed.
2724 Applications intending to use OEM strings data are encouraged to use their application name as
2725 a prefix for the value string. This facilitates passing information for multiple applications
2726 concurrently.
2727
2728 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax
2729 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes.
2730
2731 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to
2732 the SMBIOS table in the order in which they appear.
2733
2734 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535
2735 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the
2736 guest. Instead it should be used as a indicator to inform the guest where to locate the real
2737 data set, for example, by specifying the serial ID of a block device.
2738
2739 An example passing three strings is
2740
2741 .. parsed-literal::
2742
2743 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\
2744 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\
2745 path=/some/file/with/oemstringsdata.txt
2746
2747 In the guest OS this is visible with the ``dmidecode`` command
2748
2749 .. parsed-literal::
2750
2751 $ dmidecode -t 11
2752 Handle 0x0E00, DMI type 11, 5 bytes
2753 OEM Strings
2754 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/
2755 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os
2756 String 3: myapp:some extra data
2757
2758
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002759``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]``
2760 Specify SMBIOS type 17 fields
Vincent Bernat05dfb442021-04-01 19:11:38 +02002761
2762``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]``
2763 Specify SMBIOS type 41 fields
2764
2765 This argument can be repeated multiple times. Its main use is to allow network interfaces be created
2766 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface
2767 position on the PCI bus.
2768
2769 Here is an example of use:
2770
2771 .. parsed-literal::
2772
2773 -netdev user,id=internet \\
2774 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\
2775 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev
2776
2777 In the guest OS, the device should then appear as ``eno1``:
2778
2779 ..parsed-literal::
2780
2781 $ ip -brief l
2782 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP>
2783 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP>
2784
2785 Currently, the PCI device has to be attached to the root bus.
2786
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002787ERST
aliguorib6f6e3d2009-04-17 18:59:56 +00002788
Markus Armbrusterc70a01e2013-02-13 19:49:40 +01002789DEFHEADING()
blueswir15824d652009-03-28 06:44:27 +00002790
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002791DEFHEADING(Network options:)
blueswir15824d652009-03-28 06:44:27 +00002792
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002793DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
blueswir15824d652009-03-28 06:44:27 +00002794#ifdef CONFIG_SLIRP
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00002795 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n"
2796 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
Samuel Thibault0b11c032016-03-20 12:29:54 +01002797 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
Benjamin Drungf18d1372018-02-27 17:06:01 +01002798 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
Fam Zheng0fca92b2018-09-14 15:26:16 +08002799 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002800#ifndef _WIN32
Jan Kiszkac92ef6a2009-06-24 14:42:28 +02002801 "[,smb=dir[,smbserver=addr]]\n"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002802#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002803 " configure a user mode network backend with ID 'str',\n"
2804 " its DHCP server and optional services\n"
blueswir15824d652009-03-28 06:44:27 +00002805#endif
2806#ifdef _WIN32
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002807 "-netdev tap,id=str,ifname=name\n"
2808 " configure a host TAP network backend with ID 'str'\n"
blueswir15824d652009-03-28 06:44:27 +00002809#else
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002810 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002811 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002812 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002813 " [,poll-us=n]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002814 " configure a host TAP network backend with ID 'str'\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002815 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002816 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
2817 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
2818 " to deconfigure it\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002819 " use '[down]script=no' to disable script execution\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002820 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
2821 " configure it\n"
blueswir15824d652009-03-28 06:44:27 +00002822 " use 'fd=h' to connect to an already opened TAP interface\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002823 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002824 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
Michael S. Tsirkinf157ed22011-02-01 14:25:40 +02002825 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002826 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
2827 " 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 +02002828 " use vhost=on to enable experimental in kernel accelerator\n"
mst@redhat.com5430a282011-02-01 22:13:42 +02002829 " (only has effect for virtio guests which use MSIX)\n"
2830 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
Michael S. Tsirkin82b0d802010-03-17 13:08:24 +02002831 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002832 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
Jason Wangec396012013-02-22 22:57:52 +08002833 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
Michael Tokarevcba42d62021-03-09 14:15:10 +03002834 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002835 " spent on busy polling for vhost net\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002836 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
2837 " configure a host TAP network backend with ID 'str' that is\n"
2838 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
2839 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
Mark McLoughlin0df0ff62009-06-18 18:21:34 +01002840#endif
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002841#ifdef __linux__
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002842 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00002843 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n"
2844 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002845 " [,rxcookie=rxcookie][,offset=offset]\n"
2846 " configure a network backend with ID 'str' connected to\n"
2847 " an Ethernet over L2TPv3 pseudowire.\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002848 " Linux kernel 3.3+ as well as most routers can talk\n"
Michael Tokarev2f47b402014-07-24 20:10:17 +04002849 " L2TPv3. This transport allows connecting a VM to a VM,\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002850 " VM to a router and even VM to Host. It is a nearly-universal\n"
Stefan Hajnoczi21843dc2020-02-29 11:17:27 +00002851 " standard (RFC3931). Note - this implementation uses static\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002852 " pre-configured tunnels (same as the Linux kernel).\n"
2853 " use 'src=' to specify source address\n"
2854 " use 'dst=' to specify destination address\n"
2855 " use 'udp=on' to specify udp encapsulation\n"
Gonglei39526512014-08-14 14:35:48 +08002856 " use 'srcport=' to specify source udp port\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002857 " use 'dstport=' to specify destination udp port\n"
2858 " use 'ipv6=on' to force v6\n"
2859 " L2TPv3 uses cookies to prevent misconfiguration as\n"
2860 " well as a weak security measure\n"
2861 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
2862 " use 'txcookie=0x012345678' to specify a txcookie\n"
2863 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
2864 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
2865 " use 'pincounter=on' to work around broken counter handling in peer\n"
2866 " use 'offset=X' to add an extra offset between header and data\n"
2867#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002868 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
2869 " configure a network backend to connect to another network\n"
2870 " using a socket connection\n"
2871 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
2872 " configure a network backend to connect to a multicast maddr and port\n"
Mike Ryan3a75e742010-12-01 11:16:47 -08002873 " use 'localaddr=addr' to specify the host address to send packets from\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002874 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
2875 " configure a network backend to connect to another network\n"
2876 " using an UDP tunnel\n"
Laurent Vivier148fbf02023-01-19 11:16:45 +01002877 "-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"
2878 "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect=seconds]\n"
2879 "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect=seconds]\n"
Laurent Vivier5166fe02022-10-21 11:09:11 +02002880 " configure a network backend to connect to another network\n"
2881 " using a socket connection in stream mode.\n"
2882 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n"
2883 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]\n"
2884 " configure a network backend to connect to a multicast maddr and port\n"
2885 " use ``local.host=addr`` to specify the host address to send packets from\n"
2886 "-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 +02002887 "-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]\n"
Laurent Vivier5166fe02022-10-21 11:09:11 +02002888 "-netdev dgram,id=str,local.type=fd,local.str=file-descriptor\n"
2889 " configure a network backend to connect to another network\n"
2890 " using an UDP tunnel\n"
blueswir15824d652009-03-28 06:44:27 +00002891#ifdef CONFIG_VDE
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002892 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
2893 " configure a network backend to connect to port 'n' of a vde switch\n"
2894 " running on host and listening for incoming connections on 'socketpath'.\n"
blueswir15824d652009-03-28 06:44:27 +00002895 " Use group 'groupname' and mode 'octalmode' to change default\n"
2896 " ownership and permissions for communication port.\n"
2897#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002898#ifdef CONFIG_NETMAP
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002899 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
Vincenzo Maffione58952132013-11-06 11:44:06 +01002900 " attach to the existing netmap-enabled network interface 'name', or to a\n"
2901 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
2902 " netmap device, defaults to '/dev/netmap')\n"
2903#endif
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002904#ifdef CONFIG_AF_XDP
2905 "-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off]\n"
2906 " [,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]\n"
2907 " attach to the existing network interface 'name' with AF_XDP socket\n"
2908 " use 'mode=MODE' to specify an XDP program attach mode\n"
2909 " use 'force-copy=on|off' to force XDP copy mode even if device supports zero-copy (default: off)\n"
2910 " use 'inhibit=on|off' to inhibit loading of a default XDP program (default: off)\n"
2911 " with inhibit=on,\n"
2912 " use 'sock-fds' to provide file descriptors for already open AF_XDP sockets\n"
2913 " added to a socket map in XDP program. One socket per queue.\n"
2914 " use 'queues=n' to specify how many queues of a multiqueue interface should be used\n"
2915 " use 'start-queue=m' to specify the first queue that should be used\n"
2916#endif
Thomas Huth253dc142018-02-21 11:18:32 +01002917#ifdef CONFIG_POSIX
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002918 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2919 " configure a vhost-user network, backed by a chardev 'dev'\n"
Thomas Huth253dc142018-02-21 11:18:32 +01002920#endif
Cindy Lu108a6482020-07-01 22:55:37 +08002921#ifdef __linux__
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07002922 "-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n"
Cindy Lu108a6482020-07-01 22:55:37 +08002923 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n"
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07002924 " use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n"
2925 " use 'vhostfd=h' to connect to an already opened vhost vdpa device\n"
Cindy Lu108a6482020-07-01 22:55:37 +08002926#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002927#ifdef CONFIG_VMNET
2928 "-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n"
2929 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n"
2930 " configure a vmnet network backend in host mode with ID 'str',\n"
2931 " isolate this interface from others with 'isolated',\n"
2932 " configure the address range and choose a subnet mask,\n"
2933 " specify network UUID 'uuid' to disable DHCP and interact with\n"
2934 " vmnet-host interfaces within this isolated network\n"
2935 "-netdev vmnet-shared,id=str[,isolated=on|off][,nat66-prefix=addr]\n"
2936 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n"
2937 " configure a vmnet network backend in shared mode with ID 'str',\n"
2938 " configure the address range and choose a subnet mask,\n"
2939 " set IPv6 ULA prefix (of length 64) to use for internal network,\n"
2940 " isolate this interface from others with 'isolated'\n"
2941 "-netdev vmnet-bridged,id=str,ifname=name[,isolated=on|off]\n"
2942 " configure a vmnet network backend in bridged mode with ID 'str',\n"
2943 " use 'ifname=name' to select a physical network interface to be bridged,\n"
2944 " isolate this interface from others with 'isolated'\n"
2945#endif
Thomas Huth18d65d22018-01-15 20:50:55 +01002946 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002947 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
Thomas Huth78cd6f72018-02-21 11:18:36 +01002948DEF("nic", HAS_ARG, QEMU_OPTION_nic,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002949 "-nic [tap|bridge|"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002950#ifdef CONFIG_SLIRP
2951 "user|"
2952#endif
2953#ifdef __linux__
2954 "l2tpv3|"
2955#endif
2956#ifdef CONFIG_VDE
2957 "vde|"
2958#endif
2959#ifdef CONFIG_NETMAP
2960 "netmap|"
2961#endif
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002962#ifdef CONFIG_AF_XDP
2963 "af-xdp|"
2964#endif
Thomas Huth78cd6f72018-02-21 11:18:36 +01002965#ifdef CONFIG_POSIX
2966 "vhost-user|"
2967#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002968#ifdef CONFIG_VMNET
2969 "vmnet-host|vmnet-shared|vmnet-bridged|"
2970#endif
Thomas Huth78cd6f72018-02-21 11:18:36 +01002971 "socket][,option][,...][mac=macaddr]\n"
2972 " initialize an on-board / default host NIC (using MAC address\n"
2973 " macaddr) and connect it to the given host network backend\n"
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002974 "-nic none use it alone to have zero network devices (the default is to\n"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002975 " provided a 'user' network connection)\n",
2976 QEMU_ARCH_ALL)
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002977DEF("net", HAS_ARG, QEMU_OPTION_net,
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002978 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
Thomas Huth0e60a822017-12-19 16:28:55 +01002979 " configure or create an on-board (or machine default) NIC and\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002980 " connect it to hub 0 (please use -nic unless you need a hub)\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002981 "-net ["
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002982#ifdef CONFIG_SLIRP
2983 "user|"
2984#endif
2985 "tap|"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002986 "bridge|"
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002987#ifdef CONFIG_VDE
2988 "vde|"
2989#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002990#ifdef CONFIG_NETMAP
2991 "netmap|"
2992#endif
Ilya Maximetscb039ef2023-09-13 20:34:37 +02002993#ifdef CONFIG_AF_XDP
2994 "af-xdp|"
2995#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002996#ifdef CONFIG_VMNET
2997 "vmnet-host|vmnet-shared|vmnet-bridged|"
2998#endif
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002999 "socket][,option][,option][,...]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02003000 " old way to initialize a host network interface\n"
3001 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003002SRST
Ilya Maximetscb039ef2023-09-13 20:34:37 +02003003``-nic [tap|bridge|user|l2tpv3|vde|netmap|af-xdp|vhost-user|socket][,...][,mac=macaddr][,model=mn]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003004 This option is a shortcut for configuring both the on-board
3005 (default) guest NIC hardware and the host network backend in one go.
3006 The host backend options are the same as with the corresponding
3007 ``-netdev`` options below. The guest NIC model can be set with
3008 ``model=modelname``. Use ``model=help`` to list the available device
3009 types. The hardware MAC address can be set with ``mac=macaddr``.
3010
3011 The following two example do exactly the same, to show how ``-nic``
3012 can be used to shorten the command line length:
3013
3014 .. parsed-literal::
3015
3016 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
3017 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
3018
3019``-nic none``
3020 Indicate that no network devices should be configured. It is used to
3021 override the default configuration (default NIC with "user" host
3022 network backend) which is activated if no other networking options
3023 are provided.
3024
3025``-netdev user,id=id[,option][,option][,...]``
3026 Configure user mode host network backend which requires no
3027 administrator privilege to run. Valid options are:
3028
3029 ``id=id``
3030 Assign symbolic name for use in monitor commands.
3031
3032 ``ipv4=on|off and ipv6=on|off``
3033 Specify that either IPv4 or IPv6 must be enabled. If neither is
3034 specified both protocols are enabled.
3035
3036 ``net=addr[/mask]``
3037 Set IP network address the guest will see. Optionally specify
3038 the netmask, either in the form a.b.c.d or as number of valid
3039 top-most bits. Default is 10.0.2.0/24.
3040
3041 ``host=addr``
3042 Specify the guest-visible address of the host. Default is the
3043 2nd IP in the guest network, i.e. x.x.x.2.
3044
3045 ``ipv6-net=addr[/int]``
3046 Set IPv6 network address the guest will see (default is
3047 fec0::/64). The network prefix is given in the usual hexadecimal
3048 IPv6 address notation. The prefix size is optional, and is given
3049 as the number of valid top-most bits (default is 64).
3050
3051 ``ipv6-host=addr``
3052 Specify the guest-visible IPv6 address of the host. Default is
3053 the 2nd IPv6 in the guest network, i.e. xxxx::2.
3054
3055 ``restrict=on|off``
3056 If this option is enabled, the guest will be isolated, i.e. it
3057 will not be able to contact the host and no guest IP packets
3058 will be routed over the host to the outside. This option does
3059 not affect any explicitly set forwarding rules.
3060
3061 ``hostname=name``
3062 Specifies the client hostname reported by the built-in DHCP
3063 server.
3064
3065 ``dhcpstart=addr``
3066 Specify the first of the 16 IPs the built-in DHCP server can
3067 assign. Default is the 15th to 31st IP in the guest network,
3068 i.e. x.x.x.15 to x.x.x.31.
3069
3070 ``dns=addr``
3071 Specify the guest-visible address of the virtual nameserver. The
3072 address must be different from the host address. Default is the
3073 3rd IP in the guest network, i.e. x.x.x.3.
3074
3075 ``ipv6-dns=addr``
3076 Specify the guest-visible address of the IPv6 virtual
3077 nameserver. The address must be different from the host address.
3078 Default is the 3rd IP in the guest network, i.e. xxxx::3.
3079
3080 ``dnssearch=domain``
3081 Provides an entry for the domain-search list sent by the
3082 built-in DHCP server. More than one domain suffix can be
3083 transmitted by specifying this option multiple times. If
3084 supported, this will cause the guest to automatically try to
3085 append the given domain suffix(es) in case a domain name can not
3086 be resolved.
3087
3088 Example:
3089
3090 .. parsed-literal::
3091
3092 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
3093
3094 ``domainname=domain``
3095 Specifies the client domain name reported by the built-in DHCP
3096 server.
3097
3098 ``tftp=dir``
3099 When using the user mode network stack, activate a built-in TFTP
3100 server. The files in dir will be exposed as the root of a TFTP
3101 server. The TFTP client on the guest must be configured in
3102 binary mode (use the command ``bin`` of the Unix TFTP client).
Michael Tokarevb30fa6b2024-02-08 09:00:50 +03003103 The built-in TFTP server is read-only; it does not implement any
3104 command for writing files. QEMU will not write to this directory.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003105
3106 ``tftp-server-name=name``
3107 In BOOTP reply, broadcast name as the "TFTP server name"
3108 (RFC2132 option 66). This can be used to advise the guest to
3109 load boot files or configurations from a different server than
3110 the host address.
3111
3112 ``bootfile=file``
3113 When using the user mode network stack, broadcast file as the
3114 BOOTP filename. In conjunction with ``tftp``, this can be used
3115 to network boot a guest from a local directory.
3116
3117 Example (using pxelinux):
3118
3119 .. parsed-literal::
3120
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003121 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003122 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
3123
3124 ``smb=dir[,smbserver=addr]``
3125 When using the user mode network stack, activate a built-in SMB
3126 server so that Windows OSes can access to the host files in
3127 ``dir`` transparently. The IP address of the SMB server can be
3128 set to addr. By default the 4th IP in the guest network is used,
3129 i.e. x.x.x.4.
3130
3131 In the guest Windows OS, the line:
3132
3133 ::
3134
3135 10.0.2.4 smbserver
3136
3137 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows
3138 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows
3139 NT/2000).
3140
3141 Then ``dir`` can be accessed in ``\\smbserver\qemu``.
3142
3143 Note that a SAMBA server must be installed on the host OS.
3144
3145 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport``
3146 Redirect incoming TCP or UDP connections to the host port
3147 hostport to the guest IP address guestaddr on guest port
3148 guestport. If guestaddr is not specified, its value is x.x.x.15
3149 (default first address given by the built-in DHCP server). By
3150 specifying hostaddr, the rule can be bound to a specific host
3151 interface. If no connection type is set, TCP is used. This
3152 option can be given multiple times.
3153
3154 For example, to redirect host X11 connection from screen 1 to
3155 guest screen 0, use the following:
3156
Peter Maydell09ce5f22020-02-28 15:36:13 +00003157 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003158
3159 # on the host
3160 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
3161 # this host xterm should open in the guest X11 server
3162 xterm -display :1
3163
3164 To redirect telnet connections from host port 5555 to telnet
3165 port on the guest, use the following:
3166
Peter Maydell09ce5f22020-02-28 15:36:13 +00003167 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003168
3169 # on the host
3170 |qemu_system| -nic user,hostfwd=tcp::5555-:23
3171 telnet localhost 5555
3172
3173 Then when you use on the host ``telnet localhost 5555``, you
3174 connect to the guest telnet server.
3175
3176 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command``
3177 Forward guest TCP connections to the IP address server on port
3178 port to the character device dev or to a program executed by
3179 cmd:command which gets spawned for each connection. This option
3180 can be given multiple times.
3181
3182 You can either use a chardev directly and have that one used
3183 throughout QEMU's lifetime, like in the following example:
3184
Peter Maydell09ce5f22020-02-28 15:36:13 +00003185 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003186
3187 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
3188 # the guest accesses it
3189 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
3190
3191 Or you can execute a command on every TCP connection established
3192 by the guest, so that QEMU behaves similar to an inetd process
3193 for that virtual server:
3194
Peter Maydell09ce5f22020-02-28 15:36:13 +00003195 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003196
3197 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
3198 # and connect the TCP stream to its stdin/stdout
3199 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
3200
3201``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]``
3202 Configure a host TAP network backend with ID id.
3203
3204 Use the network script file to configure it and the network script
3205 dfile to deconfigure it. If name is not provided, the OS
3206 automatically provides one. The default network configure script is
3207 ``/etc/qemu-ifup`` and the default network deconfigure script is
3208 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to
3209 disable script execution.
3210
3211 If running QEMU as an unprivileged user, use the network helper
Tianjia Zhang8d73ec82020-07-27 12:59:25 +08003212 to configure the TAP interface and attach it to the bridge.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003213 The default network helper executable is
3214 ``/path/to/qemu-bridge-helper`` and the default bridge device is
3215 ``br0``.
3216
3217 ``fd``\ =h can be used to specify the handle of an already opened
3218 host TAP interface.
3219
3220 Examples:
3221
Peter Maydell09ce5f22020-02-28 15:36:13 +00003222 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003223
3224 #launch a QEMU instance with the default network script
3225 |qemu_system| linux.img -nic tap
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 two NICs, each one connected
3230 #to a TAP device
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003231 |qemu_system| linux.img \\
3232 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003233 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
3234
Peter Maydell09ce5f22020-02-28 15:36:13 +00003235 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003236
3237 #launch a QEMU instance with the default network helper to
3238 #connect a TAP device to bridge br0
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003239 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003240 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
3241
3242``-netdev bridge,id=id[,br=bridge][,helper=helper]``
3243 Connect a host TAP network interface to a host bridge device.
3244
3245 Use the network helper helper to configure the TAP interface and
3246 attach it to the bridge. The default network helper executable is
3247 ``/path/to/qemu-bridge-helper`` and the default bridge device is
3248 ``br0``.
3249
3250 Examples:
3251
Peter Maydell09ce5f22020-02-28 15:36:13 +00003252 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003253
3254 #launch a QEMU instance with the default network helper to
3255 #connect a TAP device to bridge br0
3256 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
3257
Peter Maydell09ce5f22020-02-28 15:36:13 +00003258 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003259
3260 #launch a QEMU instance with the default network helper to
3261 #connect a TAP device to bridge qemubr0
3262 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
3263
3264``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]``
3265 This host network backend can be used to connect the guest's network
3266 to another QEMU virtual machine using a TCP socket connection. If
3267 ``listen`` is specified, QEMU waits for incoming connections on port
3268 (host is optional). ``connect`` is used to connect to another QEMU
3269 instance using the ``listen`` option. ``fd``\ =h specifies an
3270 already opened TCP socket.
3271
3272 Example:
3273
Peter Maydell09ce5f22020-02-28 15:36:13 +00003274 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003275
3276 # launch a first QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003277 |qemu_system| linux.img \\
3278 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003279 -netdev socket,id=n1,listen=:1234
3280 # connect the network of this instance to the network of the first instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003281 |qemu_system| linux.img \\
3282 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003283 -netdev socket,id=n2,connect=127.0.0.1:1234
3284
3285``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]``
3286 Configure a socket host network backend to share the guest's network
3287 traffic with another QEMU virtual machines using a UDP multicast
3288 socket, effectively making a bus for every QEMU with same multicast
3289 address maddr and port. NOTES:
3290
3291 1. Several QEMU can be running on different hosts and share same bus
3292 (assuming correct multicast setup for these hosts).
3293
3294 2. mcast support is compatible with User Mode Linux (argument
3295 ``ethN=mcast``), see http://user-mode-linux.sf.net.
3296
3297 3. Use ``fd=h`` to specify an already opened UDP multicast socket.
3298
3299 Example:
3300
Peter Maydell09ce5f22020-02-28 15:36:13 +00003301 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003302
3303 # launch one QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003304 |qemu_system| linux.img \\
3305 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003306 -netdev socket,id=n1,mcast=230.0.0.1:1234
3307 # launch another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003308 |qemu_system| linux.img \\
3309 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003310 -netdev socket,id=n2,mcast=230.0.0.1:1234
3311 # launch yet another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003312 |qemu_system| linux.img \\
3313 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003314 -netdev socket,id=n3,mcast=230.0.0.1:1234
3315
3316 Example (User Mode Linux compat.):
3317
Peter Maydell09ce5f22020-02-28 15:36:13 +00003318 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003319
3320 # launch QEMU instance (note mcast address selected is UML's default)
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003321 |qemu_system| linux.img \\
3322 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003323 -netdev socket,id=n1,mcast=239.192.168.1:1102
3324 # launch UML
3325 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
3326
3327 Example (send packets from host's 1.2.3.4):
3328
3329 .. parsed-literal::
3330
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003331 |qemu_system| linux.img \\
3332 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003333 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
3334
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00003335``-netdev l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6=on|off][,udp=on|off][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003336 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931)
3337 is a popular protocol to transport Ethernet (and other Layer 2) data
3338 frames between two systems. It is present in routers, firewalls and
3339 the Linux kernel (from version 3.3 onwards).
3340
3341 This transport allows a VM to communicate to another VM, router or
3342 firewall directly.
3343
3344 ``src=srcaddr``
3345 source address (mandatory)
3346
3347 ``dst=dstaddr``
3348 destination address (mandatory)
3349
3350 ``udp``
3351 select udp encapsulation (default is ip).
3352
3353 ``srcport=srcport``
3354 source udp port.
3355
3356 ``dstport=dstport``
3357 destination udp port.
3358
3359 ``ipv6``
3360 force v6, otherwise defaults to v4.
3361
3362 ``rxcookie=rxcookie``; \ ``txcookie=txcookie``
3363 Cookies are a weak form of security in the l2tpv3 specification.
3364 Their function is mostly to prevent misconfiguration. By default
3365 they are 32 bit.
3366
3367 ``cookie64``
3368 Set cookie size to 64 bit instead of the default 32
3369
3370 ``counter=off``
3371 Force a 'cut-down' L2TPv3 with no counter as in
3372 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
3373
3374 ``pincounter=on``
3375 Work around broken counter handling in peer. This may also help
3376 on networks which have packet reorder.
3377
3378 ``offset=offset``
3379 Add an extra offset between header and data
3380
3381 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to
3382 the bridge br-lan on the remote Linux host 1.2.3.4:
3383
Peter Maydell09ce5f22020-02-28 15:36:13 +00003384 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003385
3386 # Setup tunnel on linux host using raw ip as encapsulation
3387 # on 1.2.3.4
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003388 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 +00003389 encap udp udp_sport 16384 udp_dport 16384
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003390 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003391 0xFFFFFFFF peer_session_id 0xFFFFFFFF
3392 ifconfig vmtunnel0 mtu 1500
3393 ifconfig vmtunnel0 up
3394 brctl addif br-lan vmtunnel0
3395
3396
3397 # on 4.3.2.1
3398 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
3399
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003400 |qemu_system| linux.img -device e1000,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003401 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
3402
3403``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]``
3404 Configure VDE backend to connect to PORT n of a vde switch running
3405 on host and listening for incoming connections on socketpath. Use
3406 GROUP groupname and MODE octalmode to change default ownership and
3407 permissions for communication port. This option is only available if
3408 QEMU has been compiled with vde support enabled.
3409
3410 Example:
3411
Peter Maydell09ce5f22020-02-28 15:36:13 +00003412 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003413
3414 # launch vde switch
3415 vde_switch -F -sock /tmp/myswitch
3416 # launch QEMU instance
3417 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch
3418
Ilya Maximetscb039ef2023-09-13 20:34:37 +02003419``-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]``
3420 Configure AF_XDP backend to connect to a network interface 'name'
3421 using AF_XDP socket. A specific program attach mode for a default
3422 XDP program can be forced with 'mode', defaults to best-effort,
3423 where the likely most performant mode will be in use. Number of queues
3424 'n' should generally match the number or queues in the interface,
3425 defaults to 1. Traffic arriving on non-configured device queues will
3426 not be delivered to the network backend.
3427
3428 .. parsed-literal::
3429
3430 # set number of queues to 4
3431 ethtool -L eth0 combined 4
3432 # launch QEMU instance
3433 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
3434 -netdev af-xdp,id=n1,ifname=eth0,queues=4
3435
3436 'start-queue' option can be specified if a particular range of queues
3437 [m, m + n] should be in use. For example, this is may be necessary in
3438 order to use certain NICs in native mode. Kernel allows the driver to
3439 create a separate set of XDP queues on top of regular ones, and only
3440 these queues can be used for AF_XDP sockets. NICs that work this way
3441 may also require an additional traffic redirection with ethtool to these
3442 special queues.
3443
3444 .. parsed-literal::
3445
3446 # set number of queues to 1
3447 ethtool -L eth0 combined 1
3448 # redirect all the traffic to the second queue (id: 1)
3449 # note: drivers may require non-empty key/mask pair.
3450 ethtool -N eth0 flow-type ether \\
3451 dst 00:00:00:00:00:00 m FF:FF:FF:FF:FF:FE action 1
3452 ethtool -N eth0 flow-type ether \\
3453 dst 00:00:00:00:00:01 m FF:FF:FF:FF:FF:FE action 1
3454 # launch QEMU instance
3455 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
3456 -netdev af-xdp,id=n1,ifname=eth0,queues=1,start-queue=1
3457
3458 XDP program can also be loaded externally. In this case 'inhibit' option
3459 should be set to 'on' and 'sock-fds' provided with file descriptors for
3460 already open but not bound XDP sockets already added to a socket map for
3461 corresponding queues. One socket per queue.
3462
3463 .. parsed-literal::
3464
3465 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
3466 -netdev af-xdp,id=n1,ifname=eth0,queues=3,inhibit=on,sock-fds=15:16:17
3467
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003468``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]``
3469 Establish a vhost-user netdev, backed by a chardev id. The chardev
3470 should be a unix domain socket backed one. The vhost-user uses a
3471 specifically defined protocol to pass vhost ioctl replacement
3472 messages to an application on the other end of the socket. On
3473 non-MSIX guests, the feature can be forced with vhostforce. Use
3474 'queues=n' to specify the number of queues to be created for
3475 multiqueue vhost-user.
3476
3477 Example:
3478
3479 ::
3480
3481 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
3482 -numa node,memdev=mem \
3483 -chardev socket,id=chr0,path=/path/to/socket \
3484 -netdev type=vhost-user,id=net0,chardev=chr0 \
3485 -device virtio-net-pci,netdev=net0
3486
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07003487``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]``
Cindy Lu108a6482020-07-01 22:55:37 +08003488 Establish a vhost-vdpa netdev.
3489
3490 vDPA device is a device that uses a datapath which complies with
3491 the virtio specifications with a vendor specific control path.
3492 vDPA devices can be both physically located on the hardware or
3493 emulated by software.
3494
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003495``-netdev hubport,id=id,hubid=hubid[,netdev=nd]``
3496 Create a hub port on the emulated hub with ID hubid.
3497
3498 The hubport netdev lets you connect a NIC to a QEMU emulated hub
3499 instead of a single netdev. Alternatively, you can also connect the
3500 hubport to another netdev with ID nd by using the ``netdev=nd``
3501 option.
3502
3503``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]``
3504 Legacy option to configure or create an on-board (or machine
3505 default) Network Interface Card(NIC) and connect it either to the
3506 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd.
3507 If model is omitted, then the default NIC model associated with the
3508 machine type is used. Note that the default NIC model may change in
3509 future QEMU releases, so it is highly recommended to always specify
3510 a model. Optionally, the MAC address can be changed to mac, the
3511 device address set to addr (PCI cards only), and a name can be
3512 assigned for use in monitor commands. Optionally, for PCI cards, you
3513 can specify the number v of MSI-X vectors that the card should have;
3514 this option currently only affects virtio cards; set v = 0 to
3515 disable MSI-X. If no ``-net`` option is specified, a single NIC is
3516 created. QEMU can emulate several different models of network card.
3517 Use ``-net nic,model=help`` for a list of available devices for your
3518 target.
3519
3520``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]``
3521 Configure a host network backend (with the options corresponding to
3522 the same ``-netdev`` option) and connect it to the emulated hub 0
3523 (the default hub). Use name to specify the name of the hub port.
3524ERST
blueswir15824d652009-03-28 06:44:27 +00003525
Matthew Booth7273a2d2009-10-30 13:41:12 +00003526DEFHEADING()
3527
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003528DEFHEADING(Character device options:)
Matthew Booth7273a2d2009-10-30 13:41:12 +00003529
3530DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
Lin Ma517b3d42016-08-17 01:13:52 +08003531 "-chardev help\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003532 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Markus Armbrusterba858d12021-09-28 09:14:49 +02003533 "-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 +00003534 " [,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 +00003535 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n"
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003536 "-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 +08003537 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003538 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003539 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003540 " [,logfile=PATH][,logappend=on|off]\n"
3541 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003542 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003543 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3544 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
Peter Maydell5b18a6b2023-04-13 16:07:24 +01003545 "-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 +00003546 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003547#ifdef _WIN32
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003548 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3549 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003550#else
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003551 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3552 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003553#endif
3554#ifdef CONFIG_BRLAPI
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003555 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003556#endif
3557#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
3558 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003559 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003560#endif
3561#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003562 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003563#endif
Alon Levycbcc6332011-01-19 10:49:50 +02003564#if defined(CONFIG_SPICE)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003565 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
3566 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
Alon Levycbcc6332011-01-19 10:49:50 +02003567#endif
Blue Swirlad960902010-03-29 19:23:52 +00003568 , QEMU_ARCH_ALL
Matthew Booth7273a2d2009-10-30 13:41:12 +00003569)
3570
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003571SRST
3572The general form of a character device option is:
3573
3574``-chardev backend,id=id[,mux=on|off][,options]``
3575 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``,
3576 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``,
Paolo Bonzini6f9f6302022-12-16 10:56:53 +01003577 ``pty``, ``stdio``, ``braille``, ``parallel``,
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003578 ``spicevmc``, ``spiceport``. The specific backend will determine the
3579 applicable options.
3580
3581 Use ``-chardev help`` to print all available chardev backend types.
3582
3583 All devices must have an id, which can be any string up to 127
3584 characters long. It is used to uniquely identify this device in
3585 other command line directives.
3586
3587 A character device may be used in multiplexing mode by multiple
3588 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is
3589 a "1:N" device, and here the "1" end is your specified chardev
3590 backend, and the "N" end is the various parts of QEMU that can talk
3591 to a chardev. If you create a chardev with ``id=myid`` and
3592 ``mux=on``, QEMU will create a multiplexer with your specified ID,
3593 and you can then configure multiple front ends to use that chardev
3594 ID for their input/output. Up to four different front ends can be
3595 connected to a single multiplexed chardev. (Without multiplexing
3596 enabled, a chardev can only be used by a single front end.) For
3597 instance you could use this to allow a single stdio chardev to be
3598 used by two serial ports and the QEMU monitor:
3599
3600 ::
3601
3602 -chardev stdio,mux=on,id=char0 \
3603 -mon chardev=char0,mode=readline \
3604 -serial chardev:char0 \
3605 -serial chardev:char0
3606
3607 You can have more than one multiplexer in a system configuration;
3608 for instance you could have a TCP port multiplexed between UART 0
3609 and UART 1, and stdio multiplexed between the QEMU monitor and a
3610 parallel port:
3611
3612 ::
3613
3614 -chardev stdio,mux=on,id=char0 \
3615 -mon chardev=char0,mode=readline \
3616 -parallel chardev:char0 \
3617 -chardev tcp,...,mux=on,id=char1 \
3618 -serial chardev:char1 \
3619 -serial chardev:char1
3620
3621 When you're using a multiplexed character device, some escape
Thomas Huth923e9312020-11-16 15:47:36 +01003622 sequences are interpreted in the input. See the chapter about
3623 :ref:`keys in the character backend multiplexer` in the
3624 System Emulation Users Guide for more details.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003625
3626 Note that some other command line options may implicitly create
3627 multiplexed character backends; for instance ``-serial mon:stdio``
3628 creates a multiplexed stdio backend connected to the serial port and
3629 the QEMU monitor, and ``-nographic`` also multiplexes the console
3630 and the monitor to stdio.
3631
3632 There is currently no support for multiplexing in the other
3633 direction (where a single QEMU front end takes input and output from
3634 multiple chardevs).
3635
3636 Every backend supports the ``logfile`` option, which supplies the
3637 path to a file to record all data transmitted via the backend. The
3638 ``logappend`` option controls whether the log file will be truncated
3639 or appended to when opened.
3640
3641The available backends are:
3642
3643``-chardev null,id=id``
3644 A void device. This device will not emit any data, and will drop any
3645 data it receives. The null backend does not take any options.
3646
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003647``-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 +00003648 Create a two-way stream socket, which can be either a TCP or a unix
3649 socket. A unix socket will be created if ``path`` is specified.
3650 Behaviour is undefined if TCP options are specified for a unix
3651 socket.
3652
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003653 ``server=on|off`` specifies that the socket shall be a listening socket.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003654
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003655 ``wait=on|off`` specifies that QEMU should not block waiting for a client
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003656 to connect to a listening socket.
3657
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003658 ``telnet=on|off`` specifies that traffic on the socket should interpret
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003659 telnet escape sequences.
3660
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003661 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003662 communication.
3663
3664 ``reconnect`` sets the timeout for reconnecting on non-server
3665 sockets when the remote end goes away. qemu will delay this many
3666 seconds and then attempt to reconnect. Zero disables reconnecting,
3667 and is the default.
3668
3669 ``tls-creds`` requests enablement of the TLS protocol for
3670 encryption, and specifies the id of the TLS credentials to use for
3671 the handshake. The credentials must be previously created with the
3672 ``-object tls-creds`` argument.
3673
3674 ``tls-auth`` provides the ID of the QAuthZ authorization object
3675 against which the client's x509 distinguished name will be
3676 validated. This object is only resolved at time of use, so can be
3677 deleted and recreated on the fly while the chardev server is active.
3678 If missing, it will default to denying access.
3679
3680 TCP and unix socket options are given below:
3681
Paolo Bonzinia9b13152021-02-25 11:47:52 +01003682 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003683 ``host`` for a listening socket specifies the local address to
3684 be bound. For a connecting socket species the remote host to
3685 connect to. ``host`` is optional for listening sockets. If not
3686 specified it defaults to ``0.0.0.0``.
3687
3688 ``port`` for a listening socket specifies the local port to be
3689 bound. For a connecting socket specifies the port on the remote
3690 host to connect to. ``port`` can be given as either a port
3691 number or a service name. ``port`` is required.
3692
3693 ``to`` is only relevant to listening sockets. If it is
3694 specified, and ``port`` cannot be bound, QEMU will attempt to
3695 bind to subsequent ports up to and including ``to`` until it
3696 succeeds. ``to`` must be specified as a port number.
3697
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003698 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4
3699 or IPv6 must be used. If neither is specified the socket may
3700 use either protocol.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003701
Paolo Bonzinia9b13152021-02-25 11:47:52 +01003702 ``nodelay=on|off`` disables the Nagle algorithm.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003703
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003704 ``unix options: path=path[,abstract=on|off][,tight=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003705 ``path`` specifies the local path of the unix socket. ``path``
3706 is required.
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003707 ``abstract=on|off`` specifies the use of the abstract socket namespace,
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003708 rather than the filesystem. Optional, defaults to false.
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003709 ``tight=on|off`` sets the socket length of abstract sockets to their minimum,
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003710 rather than the full sun_path length. Optional, defaults to true.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003711
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003712``-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 +00003713 Sends all traffic from the guest to a remote host over UDP.
3714
3715 ``host`` specifies the remote host to connect to. If not specified
3716 it defaults to ``localhost``.
3717
3718 ``port`` specifies the port on the remote host to connect to.
3719 ``port`` is required.
3720
3721 ``localaddr`` specifies the local address to bind to. If not
3722 specified it defaults to ``0.0.0.0``.
3723
3724 ``localport`` specifies the local port to bind to. If not specified
3725 any available local port will be used.
3726
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003727 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003728 If neither is specified the device may use either protocol.
3729
3730``-chardev msmouse,id=id``
3731 Forward QEMU's emulated msmouse events to the guest. ``msmouse``
3732 does not take any options.
3733
3734``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]``
3735 Connect to a QEMU text console. ``vc`` may optionally be given a
3736 specific size.
3737
3738 ``width`` and ``height`` specify the width and height respectively
3739 of the console, in pixels.
3740
3741 ``cols`` and ``rows`` specify that the console be sized to fit a
3742 text console with the given dimensions.
3743
3744``-chardev ringbuf,id=id[,size=size]``
3745 Create a ring buffer with fixed size ``size``. size must be a power
3746 of two and defaults to ``64K``.
3747
Peter Maydell5b18a6b2023-04-13 16:07:24 +01003748``-chardev file,id=id,path=path[,input-path=input-path]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003749 Log all traffic received from the guest to a file.
3750
3751 ``path`` specifies the path of the file to be opened. This file will
3752 be created if it does not already exist, and overwritten if it does.
3753 ``path`` is required.
3754
Peter Maydell5b18a6b2023-04-13 16:07:24 +01003755 If ``input-path`` is specified, this is the path of a second file
3756 which will be used for input. If ``input-path`` is not specified,
3757 no input will be available from the chardev.
3758
3759 Note that ``input-path`` is not supported on Windows hosts.
3760
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003761``-chardev pipe,id=id,path=path``
3762 Create a two-way connection to the guest. The behaviour differs
3763 slightly between Windows hosts and other hosts:
3764
3765 On Windows, a single duplex pipe will be created at
3766 ``\\.pipe\path``.
3767
3768 On other hosts, 2 pipes will be created called ``path.in`` and
3769 ``path.out``. Data written to ``path.in`` will be received by the
3770 guest. Data written by the guest can be read from ``path.out``. QEMU
3771 will not create these fifos, and requires them to be present.
3772
3773 ``path`` forms part of the pipe path as described above. ``path`` is
3774 required.
3775
3776``-chardev console,id=id``
3777 Send traffic from the guest to QEMU's standard output. ``console``
3778 does not take any options.
3779
3780 ``console`` is only available on Windows hosts.
3781
3782``-chardev serial,id=id,path=path``
3783 Send traffic from the guest to a serial device on the host.
3784
3785 On Unix hosts serial will actually accept any tty device, not only
3786 serial lines.
3787
3788 ``path`` specifies the name of the serial device to open.
3789
3790``-chardev pty,id=id``
3791 Create a new pseudo-terminal on the host and connect to it. ``pty``
3792 does not take any options.
3793
3794 ``pty`` is not available on Windows hosts.
3795
3796``-chardev stdio,id=id[,signal=on|off]``
3797 Connect to standard input and standard output of the QEMU process.
3798
3799 ``signal`` controls if signals are enabled on the terminal, that
3800 includes exiting QEMU with the key sequence Control-c. This option
3801 is enabled by default, use ``signal=off`` to disable it.
3802
3803``-chardev braille,id=id``
3804 Connect to a local BrlAPI server. ``braille`` does not take any
3805 options.
3806
Peter Maydell09ce5f22020-02-28 15:36:13 +00003807``-chardev parallel,id=id,path=path``
3808 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003809 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD
3810 hosts.
3811
3812 Connect to a local parallel port.
3813
3814 ``path`` specifies the path to the parallel port device. ``path`` is
3815 required.
3816
3817``-chardev spicevmc,id=id,debug=debug,name=name``
3818 ``spicevmc`` is only available when spice support is built in.
3819
3820 ``debug`` debug level for spicevmc
3821
3822 ``name`` name of spice channel to connect to
3823
3824 Connect to a spice virtual machine channel, such as vdiport.
3825
3826``-chardev spiceport,id=id,debug=debug,name=name``
3827 ``spiceport`` is only available when spice support is built in.
3828
3829 ``debug`` debug level for spicevmc
3830
3831 ``name`` name of spice port to connect to
3832
3833 Connect to a spice port, allowing a Spice client to handle the
3834 traffic identified by a name (preferably a fqdn).
3835ERST
Matthew Booth7273a2d2009-10-30 13:41:12 +00003836
3837DEFHEADING()
3838
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003839#ifdef CONFIG_TPM
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003840DEFHEADING(TPM device options:)
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003841
3842DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
Stefan Berger92dcc232013-02-27 12:47:54 -05003843 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
3844 " use path to provide path to a character device; default is /dev/tpm0\n"
3845 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
Amarnath Vallurif4ede812017-09-29 14:10:20 +03003846 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
3847 "-tpmdev emulator,id=id,chardev=dev\n"
3848 " configure the TPM device using chardev backend\n",
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003849 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003850SRST
3851The general form of a TPM device option is:
3852
3853``-tpmdev backend,id=id[,options]``
3854 The specific backend type will determine the applicable options. The
3855 ``-tpmdev`` option creates the TPM backend and requires a
3856 ``-device`` option that specifies the TPM frontend interface model.
3857
3858 Use ``-tpmdev help`` to print all available TPM backend types.
3859
3860The available backends are:
3861
3862``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path``
3863 (Linux-host only) Enable access to the host's TPM using the
3864 passthrough driver.
3865
3866 ``path`` specifies the path to the host's TPM device, i.e., on a
3867 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by
3868 default ``/dev/tpm0`` is used.
3869
3870 ``cancel-path`` specifies the path to the host TPM device's sysfs
3871 entry allowing for cancellation of an ongoing TPM command.
3872 ``cancel-path`` is optional and by default QEMU will search for the
3873 sysfs entry to use.
3874
3875 Some notes about using the host's TPM with the passthrough driver:
3876
3877 The TPM device accessed by the passthrough driver must not be used
3878 by any other application on the host.
3879
3880 Since the host's firmware (BIOS/UEFI) has already initialized the
3881 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize
3882 the TPM again and may therefore not show a TPM-specific menu that
3883 would otherwise allow the user to configure the TPM, e.g., allow the
3884 user to enable/disable or activate/deactivate the TPM. Further, if
3885 TPM ownership is released from within a VM then the host's TPM will
3886 get disabled and deactivated. To enable and activate the TPM again
3887 afterwards, the host has to be rebooted and the user is required to
3888 enter the firmware's menu to enable and activate the TPM. If the TPM
3889 is left disabled and/or deactivated most TPM commands will fail.
3890
3891 To create a passthrough TPM use the following two options:
3892
3893 ::
3894
3895 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
3896
3897 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by
3898 ``tpmdev=tpm0`` in the device option.
3899
3900``-tpmdev emulator,id=id,chardev=dev``
3901 (Linux-host only) Enable access to a TPM emulator using Unix domain
3902 socket based chardev backend.
3903
3904 ``chardev`` specifies the unique ID of a character device backend
3905 that provides connection to the software TPM server.
3906
3907 To create a TPM emulator backend device with chardev socket backend:
3908
3909 ::
3910
3911 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
3912ERST
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003913
3914DEFHEADING()
3915
3916#endif
3917
Alex Bennée1235cf72022-07-25 15:05:20 +01003918DEFHEADING(Boot Image or Kernel specific:)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003919SRST
Alex Bennée1235cf72022-07-25 15:05:20 +01003920There are broadly 4 ways you can boot a system with QEMU.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003921
Alex Bennée1235cf72022-07-25 15:05:20 +01003922 - specify a firmware and let it control finding a kernel
3923 - specify a firmware and pass a hint to the kernel to boot
3924 - direct kernel image boot
3925 - manually load files into the guest's address space
3926
3927The third method is useful for quickly testing kernels but as there is
3928no firmware to pass configuration information to the kernel the
3929hardware must either be probeable, the kernel built for the exact
3930configuration or passed some configuration data (e.g. a DTB blob)
3931which tells the kernel what drivers it needs. This exact details are
3932often hardware specific.
3933
3934The final method is the most generic way of loading images into the
3935guest address space and used mostly for ``bare metal`` type
3936development where the reset vectors of the processor are taken into
3937account.
3938
3939ERST
3940
3941SRST
3942
3943For x86 machines and some other architectures ``-bios`` will generally
3944do the right thing with whatever it is given. For other machines the
3945more strict ``-pflash`` option needs an image that is sized for the
3946flash device for the given machine type.
3947
3948Please see the :ref:`system-targets-ref` section of the manual for
3949more detailed documentation.
3950
3951ERST
3952
3953DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3954 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
3955SRST
3956``-bios file``
3957 Set the filename for the BIOS.
3958ERST
3959
3960DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
3961 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
3962SRST
3963``-pflash file``
3964 Use file as a parallel flash image.
3965ERST
3966
3967SRST
3968
3969The kernel options were designed to work with Linux kernels although
3970other things (like hypervisors) can be packaged up as a kernel
3971executable image. The exact format of a executable image is usually
3972architecture specific.
3973
3974The way in which the kernel is started (what address it is loaded at,
3975what if any information is passed to it via CPU registers, the state
3976of the hardware when it is started, and so on) is also architecture
3977specific. Typically it follows the specification laid down by the
3978Linux kernel for how kernels for that architecture must be started.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003979
3980ERST
blueswir15824d652009-03-28 06:44:27 +00003981
3982DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
Blue Swirlad960902010-03-29 19:23:52 +00003983 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003984SRST
3985``-kernel bzImage``
3986 Use bzImage as kernel image. The kernel can be either a Linux kernel
3987 or in multiboot format.
3988ERST
blueswir15824d652009-03-28 06:44:27 +00003989
3990DEF("append", HAS_ARG, QEMU_OPTION_append, \
Blue Swirlad960902010-03-29 19:23:52 +00003991 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003992SRST
3993``-append cmdline``
3994 Use cmdline as kernel command line
3995ERST
blueswir15824d652009-03-28 06:44:27 +00003996
3997DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
Blue Swirlad960902010-03-29 19:23:52 +00003998 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
David Woodhouse1eeb4322024-01-30 19:01:43 +00003999SRST(initrd)
David Woodhousecc9d10b2023-10-19 15:30:23 +01004000
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004001``-initrd file``
4002 Use file as initial ram disk.
4003
4004``-initrd "file1 arg=foo,file2"``
4005 This syntax is only available with multiboot.
4006
David Woodhousecc9d10b2023-10-19 15:30:23 +01004007 Use file1 and file2 as modules and pass ``arg=foo`` as parameter to the
4008 first module. Commas can be provided in module parameters by doubling
4009 them on the command line to escape them:
4010
4011``-initrd "bzImage earlyprintk=xen,,keep root=/dev/xvda1,initrd.img"``
4012 Multiboot only. Use bzImage as the first module with
4013 "``earlyprintk=xen,keep root=/dev/xvda1``" as its command line,
4014 and initrd.img as the second module.
4015
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004016ERST
blueswir15824d652009-03-28 06:44:27 +00004017
Grant Likely412beee2012-03-02 11:56:38 +00004018DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
Peter A. G. Crosthwaite379b5c72012-03-04 21:03:54 +10004019 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004020SRST
4021``-dtb file``
4022 Use file as a device tree binary (dtb) image and pass it to the
4023 kernel on boot.
4024ERST
Grant Likely412beee2012-03-02 11:56:38 +00004025
Alex Bennée1235cf72022-07-25 15:05:20 +01004026SRST
4027
4028Finally you can also manually load images directly into the address
4029space of the guest. This is most useful for developers who already
4030know the layout of their guest and take care to ensure something sane
4031will happen when the reset vector executes.
4032
4033The generic loader can be invoked by using the loader device:
4034
4035``-device loader,addr=<addr>,data=<data>,data-len=<data-len>[,data-be=<data-be>][,cpu-num=<cpu-num>]``
4036
4037there is also the guest loader which operates in a similar way but
4038tweaks the DTB so a hypervisor loaded via ``-kernel`` can find where
4039the guest image is:
4040
4041``-device guest-loader,addr=<addr>[,kernel=<path>,[bootargs=<arguments>]][,initrd=<path>]``
4042
4043ERST
4044
blueswir15824d652009-03-28 06:44:27 +00004045DEFHEADING()
4046
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02004047DEFHEADING(Debug/Expert options:)
blueswir15824d652009-03-28 06:44:27 +00004048
Markus Armbruster6dd75472021-03-18 16:55:10 +01004049DEF("compat", HAS_ARG, QEMU_OPTION_compat,
Markus Armbrusterdbb675c2021-03-18 16:55:19 +01004050 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n"
Markus Armbruster57df0df2021-10-28 12:25:20 +02004051 " Policy for handling deprecated management interfaces\n"
4052 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n"
4053 " Policy for handling unstable management interfaces\n",
Markus Armbruster6dd75472021-03-18 16:55:10 +01004054 QEMU_ARCH_ALL)
4055SRST
4056``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]``
4057 Set policy for handling deprecated management interfaces (experimental):
4058
4059 ``deprecated-input=accept`` (default)
4060 Accept deprecated commands and arguments
4061 ``deprecated-input=reject``
4062 Reject deprecated commands and arguments
Markus Armbrusterdbb675c2021-03-18 16:55:19 +01004063 ``deprecated-input=crash``
4064 Crash on deprecated commands and arguments
Markus Armbruster6dd75472021-03-18 16:55:10 +01004065 ``deprecated-output=accept`` (default)
4066 Emit deprecated command results and events
4067 ``deprecated-output=hide``
4068 Suppress deprecated command results and events
4069
4070 Limitation: covers only syntactic aspects of QMP.
Markus Armbruster57df0df2021-10-28 12:25:20 +02004071
4072``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]``
4073 Set policy for handling unstable management interfaces (experimental):
4074
4075 ``unstable-input=accept`` (default)
4076 Accept unstable commands and arguments
4077 ``unstable-input=reject``
4078 Reject unstable commands and arguments
4079 ``unstable-input=crash``
4080 Crash on unstable commands and arguments
4081 ``unstable-output=accept`` (default)
4082 Emit unstable command results and events
4083 ``unstable-output=hide``
4084 Suppress unstable command results and events
4085
4086 Limitation: covers only syntactic aspects of QMP.
Markus Armbruster6dd75472021-03-18 16:55:10 +01004087ERST
4088
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04004089DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
4090 "-fw_cfg [name=]<name>,file=<file>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02004091 " add named fw_cfg entry with contents from file\n"
Gabriel L. Somlo6407d762015-09-29 12:29:01 -04004092 "-fw_cfg [name=]<name>,string=<str>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02004093 " add named fw_cfg entry with contents from string\n",
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04004094 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004095SRST
4096``-fw_cfg [name=]name,file=file``
4097 Add named fw\_cfg entry with contents from file file.
Yihuan Panfd49b212023-12-13 22:17:07 +08004098 If the filename contains comma, you must double it (for instance,
4099 "file=my,,file" to use file "my,file").
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004100
4101``-fw_cfg [name=]name,string=str``
4102 Add named fw\_cfg entry with contents from string str.
Yihuan Panfd49b212023-12-13 22:17:07 +08004103 If the string contains comma, you must double it (for instance,
4104 "string=my,,string" to use file "my,string").
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004105
4106 The terminating NUL character of the contents of str will not be
4107 included as part of the fw\_cfg item data. To insert contents with
4108 embedded NUL characters, you have to use the file parameter.
4109
4110 The fw\_cfg entries are passed by QEMU through to the guest.
4111
4112 Example:
4113
4114 ::
4115
4116 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
4117
4118 creates an fw\_cfg entry named opt/com.mycompany/blob with contents
4119 from ./my\_blob.bin.
4120ERST
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04004121
blueswir15824d652009-03-28 06:44:27 +00004122DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
Blue Swirlad960902010-03-29 19:23:52 +00004123 "-serial dev redirect the serial port to char device 'dev'\n",
4124 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004125SRST
4126``-serial dev``
4127 Redirect the virtual serial port to host character device dev. The
4128 default device is ``vc`` in graphical mode and ``stdio`` in non
4129 graphical mode.
4130
4131 This option can be used several times to simulate up to 4 serial
4132 ports.
4133
Peter Maydell747bfaf2024-01-22 16:36:07 +00004134 You can use ``-serial none`` to suppress the creation of default
4135 serial devices.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004136
4137 Available character devices are:
4138
4139 ``vc[:WxH]``
4140 Virtual console. Optionally, a width and height can be given in
4141 pixel with
4142
4143 ::
4144
4145 vc:800x600
4146
4147 It is also possible to specify width or height in characters:
4148
4149 ::
4150
4151 vc:80Cx24C
4152
4153 ``pty``
4154 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
4155
4156 ``none``
Peter Maydell747bfaf2024-01-22 16:36:07 +00004157 No device is allocated. Note that for machine types which
4158 emulate systems where a serial device is always present in
4159 real hardware, this may be equivalent to the ``null`` option,
4160 in that the serial device is still present but all output
4161 is discarded. For boards where the number of serial ports is
4162 truly variable, this suppresses the creation of the device.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004163
4164 ``null``
Peter Maydell747bfaf2024-01-22 16:36:07 +00004165 A guest will see the UART or serial device as present in the
4166 machine, but all output is discarded, and there is no input.
4167 Conceptually equivalent to redirecting the output to ``/dev/null``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004168
4169 ``chardev:id``
4170 Use a named character device defined with the ``-chardev``
4171 option.
4172
4173 ``/dev/XXX``
4174 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial
4175 port parameters are set according to the emulated ones.
4176
4177 ``/dev/parportN``
4178 [Linux only, parallel port only] Use host parallel port N.
4179 Currently SPP and EPP parallel port features can be used.
4180
4181 ``file:filename``
4182 Write output to filename. No character can be read.
4183
4184 ``stdio``
4185 [Unix only] standard input/output
4186
4187 ``pipe:filename``
4188 name pipe filename
4189
4190 ``COMn``
4191 [Windows only] Use host serial port n
4192
4193 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]``
4194 This implements UDP Net Console. When remote\_host or src\_ip
4195 are not specified they default to ``0.0.0.0``. When not using a
4196 specified src\_port a random port is automatically chosen.
4197
4198 If you just want a simple readonly console you can use
4199 ``netcat`` or ``nc``, by starting QEMU with:
4200 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time
4201 QEMU writes something to that port it will appear in the
4202 netconsole session.
4203
4204 If you plan to send characters back via netconsole or you want
4205 to stop and start QEMU a lot of times, you should have QEMU use
4206 the same source port each time by using something like ``-serial
4207 udp::4555@:4556`` to QEMU. Another approach is to use a patched
4208 version of netcat which can listen to a TCP port and send and
4209 receive characters via udp. If you have a patched version of
4210 netcat which activates telnet remote echo and single char
4211 transfer, then you can use the following options to set up a
4212 netcat redirector to allow telnet on port 5555 to access the
4213 QEMU port.
4214
4215 ``QEMU Options:``
4216 -serial udp::4555@:4556
4217
4218 ``netcat options:``
4219 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
4220
4221 ``telnet options:``
4222 localhost 5555
4223
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004224 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004225 The TCP Net Console has two modes of operation. It can send the
4226 serial I/O to a location or wait for a connection from a
4227 location. By default the TCP Net Console is sent to host at the
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004228 port. If you use the ``server=on`` option QEMU will wait for a client
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004229 socket application to connect to the port before continuing,
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004230 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004231 option disables the Nagle buffering algorithm. The ``reconnect=on``
4232 option only applies if ``server=no`` is set, if the connection goes
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004233 down it will attempt to reconnect at the given interval. If host
4234 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004235 time is accepted. You can use ``telnet=on`` to connect to the
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004236 corresponding character device.
4237
4238 ``Example to send tcp console to 192.168.0.2 port 4444``
4239 -serial tcp:192.168.0.2:4444
4240
4241 ``Example to listen and wait on port 4444 for connection``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004242 -serial tcp::4444,server=on
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004243
4244 ``Example to not wait and listen on ip 192.168.0.100 port 4444``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004245 -serial tcp:192.168.0.100:4444,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004246
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004247 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004248 The telnet protocol is used instead of raw tcp sockets. The
4249 options work the same as if you had specified ``-serial tcp``.
4250 The difference is that the port acts like a telnet server or
4251 client using telnet option negotiation. This will also allow you
4252 to send the MAGIC\_SYSRQ sequence if you use a telnet that
4253 supports sending the break sequence. Typically in unix telnet
4254 you do it with Control-] and then type "send break" followed by
4255 pressing the enter key.
4256
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004257 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004258 The WebSocket protocol is used instead of raw tcp socket. The
4259 port acts as a WebSocket server. Client mode is not supported.
4260
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004261 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004262 A unix domain socket is used instead of a tcp socket. The option
4263 works the same as if you had specified ``-serial tcp`` except
4264 the unix domain socket path is used for connections.
4265
4266 ``mon:dev_string``
4267 This is a special option to allow the monitor to be multiplexed
4268 onto another serial port. The monitor is accessed with key
4269 sequence of Control-a and then pressing c. dev\_string should be
4270 any one of the serial devices specified above. An example to
4271 multiplex the monitor onto a telnet server listening on port
4272 4444 would be:
4273
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004274 ``-serial mon:telnet::4444,server=on,wait=off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004275
4276 When the monitor is multiplexed to stdio in this way, Ctrl+C
4277 will not terminate QEMU any more but will be passed to the guest
4278 instead.
4279
4280 ``braille``
4281 Braille device. This will use BrlAPI to display the braille
4282 output on a real or fake device.
4283
4284 ``msmouse``
4285 Three button serial mouse. Configure the guest to use Microsoft
4286 protocol.
4287ERST
blueswir15824d652009-03-28 06:44:27 +00004288
4289DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
Blue Swirlad960902010-03-29 19:23:52 +00004290 "-parallel dev redirect the parallel port to char device 'dev'\n",
4291 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004292SRST
4293``-parallel dev``
4294 Redirect the virtual parallel port to host device dev (same devices
4295 as the serial port). On Linux hosts, ``/dev/parportN`` can be used
4296 to use hardware devices connected on the corresponding host parallel
4297 port.
4298
4299 This option can be used several times to simulate up to 3 parallel
4300 ports.
4301
4302 Use ``-parallel none`` to disable all parallel ports.
4303ERST
blueswir15824d652009-03-28 06:44:27 +00004304
4305DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
Blue Swirlad960902010-03-29 19:23:52 +00004306 "-monitor dev redirect the monitor to char device 'dev'\n",
4307 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004308SRST
4309``-monitor dev``
4310 Redirect the monitor to host device dev (same devices as the serial
4311 port). The default device is ``vc`` in graphical mode and ``stdio``
4312 in non graphical mode. Use ``-monitor none`` to disable the default
4313 monitor.
4314ERST
Gerd Hoffmann6ca55822009-12-08 13:11:52 +01004315DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
Blue Swirlad960902010-03-29 19:23:52 +00004316 "-qmp dev like -monitor but opens in 'control' mode\n",
4317 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004318SRST
4319``-qmp dev``
Peter Maydell0ec44682023-05-15 17:22:45 +01004320 Like ``-monitor`` but opens in 'control' mode. For example, to make
4321 QMP available on localhost port 4444::
4322
4323 -qmp tcp:localhost:4444,server=on,wait=off
4324
4325 Not all options are configurable via this syntax; for maximum
4326 flexibility use the ``-mon`` option and an accompanying ``-chardev``.
4327
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004328ERST
Max Reitz4821cd42014-11-17 13:31:04 +01004329DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
4330 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
4331 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004332SRST
4333``-qmp-pretty dev``
Peter Maydell0ec44682023-05-15 17:22:45 +01004334 Like ``-qmp`` but uses pretty JSON formatting.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004335ERST
blueswir15824d652009-03-28 06:44:27 +00004336
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01004337DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
Vicente Jimenez Aguilaref670722017-11-14 09:11:27 +01004338 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004339SRST
4340``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]``
Peter Maydell0ec44682023-05-15 17:22:45 +01004341 Set up a monitor connected to the chardev ``name``.
4342 QEMU supports two monitors: the Human Monitor Protocol
4343 (HMP; for human interaction), and the QEMU Monitor Protocol
4344 (QMP; a JSON RPC-style protocol).
4345 The default is HMP; ``mode=control`` selects QMP instead.
4346 ``pretty`` is only valid when ``mode=control``,
Ali Shirvani16b3f3b2021-05-19 11:41:45 +04304347 turning on JSON pretty printing to ease
Daniel P. Berrangé283d8452021-02-19 17:56:13 +00004348 human reading and debugging.
Peter Maydell0ec44682023-05-15 17:22:45 +01004349
4350 For example::
4351
4352 -chardev socket,id=mon1,host=localhost,port=4444,server=on,wait=off \
4353 -mon chardev=mon1,mode=control,pretty=on
4354
4355 enables the QMP monitor on localhost port 4444 with pretty-printing.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004356ERST
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01004357
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08004358DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
Blue Swirlad960902010-03-29 19:23:52 +00004359 "-debugcon dev redirect the debug console to char device 'dev'\n",
4360 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004361SRST
4362``-debugcon dev``
4363 Redirect the debug console to host device dev (same devices as the
4364 serial port). The debug console is an I/O port which is typically
4365 port 0xe9; writing to that I/O port sends output to this device. The
4366 default device is ``vc`` in graphical mode and ``stdio`` in non
4367 graphical mode.
4368ERST
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08004369
blueswir15824d652009-03-28 06:44:27 +00004370DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
Blue Swirlad960902010-03-29 19:23:52 +00004371 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004372SRST
4373``-pidfile file``
4374 Store the QEMU process PID in file. It is useful if you launch QEMU
4375 from a script.
4376ERST
blueswir15824d652009-03-28 06:44:27 +00004377
Igor Mammedov047f7032018-05-11 19:24:43 +02004378DEF("preconfig", 0, QEMU_OPTION_preconfig, \
Markus Armbruster361ac942018-07-05 11:14:02 +02004379 "--preconfig pause QEMU before machine is initialized (experimental)\n",
Igor Mammedov047f7032018-05-11 19:24:43 +02004380 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004381SRST
4382``--preconfig``
4383 Pause QEMU for interactive configuration before the machine is
4384 created, which allows querying and configuring properties that will
4385 affect machine initialization. Use QMP command 'x-exit-preconfig' to
4386 exit the preconfig state and move to the next state (i.e. run guest
4387 if -S isn't used or pause the second time if -S is used). This
4388 option is experimental.
4389ERST
Igor Mammedov047f7032018-05-11 19:24:43 +02004390
blueswir15824d652009-03-28 06:44:27 +00004391DEF("S", 0, QEMU_OPTION_S, \
Blue Swirlad960902010-03-29 19:23:52 +00004392 "-S freeze CPU at startup (use 'c' to start execution)\n",
4393 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004394SRST
4395``-S``
4396 Do not start CPU at startup (you must type 'c' in the monitor).
4397ERST
blueswir15824d652009-03-28 06:44:27 +00004398
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004399DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02004400 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n"
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004401 " run qemu with overcommit hints\n"
4402 " mem-lock=on|off controls memory lock support (default: off)\n"
4403 " cpu-pm=on|off controls cpu power management (default: off)\n",
4404 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004405SRST
4406``-overcommit mem-lock=on|off``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004407 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004408``-overcommit cpu-pm=on|off``
4409 Run qemu with hints about host resource overcommit. The default is
4410 to assume that host overcommits all resources.
4411
4412 Locking qemu and guest memory can be enabled via ``mem-lock=on``
4413 (disabled by default). This works when host memory is not
Thomas Huthc8c9dc42020-12-10 16:58:07 +01004414 overcommitted and reduces the worst-case latency for guest.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004415
4416 Guest ability to manage power state of host cpus (increasing latency
4417 for other processes on the same host cpu, but decreasing latency for
4418 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This
4419 works best when host CPU is not overcommitted. When used, host
4420 estimates of CPU cycle and power utilization will be incorrect, not
4421 taking into account guest idle time.
4422ERST
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004423
aliguori59030a82009-04-05 18:43:41 +00004424DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
Peter Maydelle5910d42020-04-03 10:40:14 +01004425 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n"
4426 " the guest without waiting for gdb to connect; use -S too\n"
4427 " if you want it to not start execution.)\n",
4428 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004429SRST
4430``-gdb dev``
Thomas Huth923e9312020-11-16 15:47:36 +01004431 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter
4432 in the System Emulation Users Guide). Note that this option does not pause QEMU
Peter Maydelle5910d42020-04-03 10:40:14 +01004433 execution -- if you want QEMU to not start the guest until you
4434 connect with gdb and issue a ``continue`` command, you will need to
4435 also pass the ``-S`` option to QEMU.
4436
4437 The most usual configuration is to listen on a local TCP socket::
4438
4439 -gdb tcp::3117
4440
4441 but you can specify other backends; UDP, pseudo TTY, or even stdio
4442 are all reasonable use cases. For example, a stdio connection
4443 allows you to start QEMU from within gdb and establish the
4444 connection via a pipe:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004445
Peter Maydell09ce5f22020-02-28 15:36:13 +00004446 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004447
4448 (gdb) target remote | exec |qemu_system| -gdb stdio ...
4449ERST
blueswir15824d652009-03-28 06:44:27 +00004450
aliguori59030a82009-04-05 18:43:41 +00004451DEF("s", 0, QEMU_OPTION_s, \
Blue Swirlad960902010-03-29 19:23:52 +00004452 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
4453 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004454SRST
4455``-s``
4456 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
Thomas Huth923e9312020-11-16 15:47:36 +01004457 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004458ERST
blueswir15824d652009-03-28 06:44:27 +00004459
4460DEF("d", HAS_ARG, QEMU_OPTION_d, \
Peter Maydell989b6972013-02-26 17:52:40 +00004461 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
Blue Swirlad960902010-03-29 19:23:52 +00004462 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004463SRST
4464``-d item1[,...]``
4465 Enable logging of specified items. Use '-d help' for a list of log
4466 items.
4467ERST
blueswir15824d652009-03-28 06:44:27 +00004468
Matthew Fernandezc235d732011-06-07 16:32:40 +00004469DEF("D", HAS_ARG, QEMU_OPTION_D, \
Peter Maydell989b6972013-02-26 17:52:40 +00004470 "-D logfile output log to logfile (default stderr)\n",
Matthew Fernandezc235d732011-06-07 16:32:40 +00004471 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004472SRST
4473``-D logfile``
4474 Output log in logfile instead of to stderr
4475ERST
Matthew Fernandezc235d732011-06-07 16:32:40 +00004476
Alex Bennée35145522016-03-15 14:30:20 +00004477DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
4478 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
4479 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004480SRST
4481``-dfilter range1[,...]``
4482 Filter debug output to that relevant to a range of target addresses.
4483 The filter spec can be either start+size, start-size or start..end
4484 where start end and size are the addresses and sizes required. For
4485 example:
4486
4487 ::
4488
4489 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
4490
4491 Will dump output for any code in the 0x1000 sized block starting at
4492 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and
4493 another 0x1000 sized block starting at 0xffffffc00005f000.
4494ERST
Alex Bennée35145522016-03-15 14:30:20 +00004495
Richard Henderson9c09a252019-03-14 13:06:29 -07004496DEF("seed", HAS_ARG, QEMU_OPTION_seed, \
4497 "-seed number seed the pseudo-random number generator\n",
4498 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004499SRST
4500``-seed number``
4501 Force the guest to use a deterministic pseudo-random number
4502 generator, seeded with number. This does not affect crypto routines
4503 within the host.
4504ERST
Richard Henderson9c09a252019-03-14 13:06:29 -07004505
blueswir15824d652009-03-28 06:44:27 +00004506DEF("L", HAS_ARG, QEMU_OPTION_L, \
Blue Swirlad960902010-03-29 19:23:52 +00004507 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
4508 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004509SRST
4510``-L path``
4511 Set the directory for the BIOS, VGA BIOS and keymaps.
4512
4513 To list all the data directories, use ``-L help``.
4514ERST
blueswir15824d652009-03-28 06:44:27 +00004515
blueswir15824d652009-03-28 06:44:27 +00004516DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
Thomas Huth21abf012022-04-27 15:49:06 +02004517 "-enable-kvm enable KVM full virtualization support\n",
4518 QEMU_ARCH_ARM | QEMU_ARCH_I386 | QEMU_ARCH_MIPS | QEMU_ARCH_PPC |
4519 QEMU_ARCH_RISCV | QEMU_ARCH_S390X)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004520SRST
4521``-enable-kvm``
4522 Enable KVM full virtualization support. This option is only
4523 available if KVM support is enabled when compiling.
4524ERST
blueswir15824d652009-03-28 06:44:27 +00004525
aliguorie37630c2009-04-22 15:19:10 +00004526DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
Thomas Hutheeb36472022-04-27 15:31:56 +02004527 "-xen-domid id specify xen guest domain id\n",
4528 QEMU_ARCH_ARM | QEMU_ARCH_I386)
aliguorie37630c2009-04-22 15:19:10 +00004529DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
4530 "-xen-attach attach to existing xen domain\n"
Anthony PERARD1077bca2018-09-14 12:18:30 +01004531 " libxl will use this when starting QEMU\n",
Thomas Hutheeb36472022-04-27 15:31:56 +02004532 QEMU_ARCH_ARM | QEMU_ARCH_I386)
Paul Durrant1c599472017-03-22 09:39:15 +00004533DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
4534 "-xen-domid-restrict restrict set of available xen operations\n"
4535 " to specified domain id. (Does not affect\n"
4536 " xenpv machine type).\n",
Thomas Hutheeb36472022-04-27 15:31:56 +02004537 QEMU_ARCH_ARM | QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004538SRST
4539``-xen-domid id``
4540 Specify xen guest domain id (XEN only).
4541
4542``-xen-attach``
4543 Attach to existing xen domain. libxl will use this when starting
4544 QEMU (XEN only). Restrict set of available xen operations to
4545 specified domain id (XEN only).
4546ERST
aliguorie37630c2009-04-22 15:19:10 +00004547
blueswir15824d652009-03-28 06:44:27 +00004548DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
Blue Swirlad960902010-03-29 19:23:52 +00004549 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004550SRST
4551``-no-reboot``
4552 Exit instead of rebooting.
4553ERST
blueswir15824d652009-03-28 06:44:27 +00004554
4555DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
Blue Swirlad960902010-03-29 19:23:52 +00004556 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004557SRST
4558``-no-shutdown``
4559 Don't exit QEMU on guest shutdown, but instead only stop the
4560 emulation. This allows for instance switching to monitor to commit
4561 changes to the disk image.
4562ERST
blueswir15824d652009-03-28 06:44:27 +00004563
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004564DEF("action", HAS_ARG, QEMU_OPTION_action,
Paolo Bonzinic27025e2021-01-20 14:30:27 +01004565 "-action reboot=reset|shutdown\n"
4566 " action when guest reboots [default=reset]\n"
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004567 "-action shutdown=poweroff|pause\n"
4568 " action when guest shuts down [default=poweroff]\n"
Ilya Leoshkevich0882caf2022-07-26 00:37:45 +02004569 "-action panic=pause|shutdown|exit-failure|none\n"
Paolo Bonzinic27025e2021-01-20 14:30:27 +01004570 " action when guest panics [default=shutdown]\n"
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004571 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n"
4572 " action when watchdog fires [default=reset]\n",
4573 QEMU_ARCH_ALL)
4574SRST
4575``-action event=action``
4576 The action parameter serves to modify QEMU's default behavior when
4577 certain guest events occur. It provides a generic method for specifying the
4578 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown``
4579 parameters.
4580
4581 Examples:
4582
Alejandro Jimenezc753e8e2020-12-11 17:31:52 -05004583 ``-action panic=none``
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004584 ``-action reboot=shutdown,shutdown=pause``
Paolo Bonzini5433af72022-09-10 13:44:47 +02004585 ``-device i6300esb -action watchdog=pause``
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004586
4587ERST
4588
blueswir15824d652009-03-28 06:44:27 +00004589DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
4590 "-loadvm [tag|id]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004591 " start right away with a saved state (loadvm in monitor)\n",
4592 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004593SRST
4594``-loadvm file``
4595 Start right away with a saved state (``loadvm`` in monitor)
4596ERST
blueswir15824d652009-03-28 06:44:27 +00004597
4598#ifndef _WIN32
4599DEF("daemonize", 0, QEMU_OPTION_daemonize, \
Blue Swirlad960902010-03-29 19:23:52 +00004600 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004601#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004602SRST
4603``-daemonize``
4604 Daemonize the QEMU process after initialization. QEMU will not
4605 detach from standard IO until it is ready to receive connections on
4606 any of its devices. This option is a useful way for external
4607 programs to launch QEMU without having to cope with initialization
4608 race conditions.
4609ERST
blueswir15824d652009-03-28 06:44:27 +00004610
4611DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
Blue Swirlad960902010-03-29 19:23:52 +00004612 "-option-rom rom load a file, rom, into the option ROM space\n",
4613 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004614SRST
4615``-option-rom file``
4616 Load the contents of file as an option ROM. This option is useful to
4617 load things like EtherBoot.
4618ERST
blueswir15824d652009-03-28 06:44:27 +00004619
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02004620DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
Artem Pisarenko238d1242018-10-18 13:12:52 +06004621 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004622 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
4623 QEMU_ARCH_ALL)
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02004624
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004625SRST
4626``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]``
4627 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at
4628 the current UTC or local time, respectively. ``localtime`` is
4629 required for correct date in MS-DOS or Windows. To start at a
4630 specific point in time, provide datetime in the format
4631 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC.
4632
4633 By default the RTC is driven by the host system time. This allows
4634 using of the RTC as accurate reference clock inside the guest,
4635 specifically if the host time is smoothly following an accurate
4636 external reference clock, e.g. via NTP. If you want to isolate the
4637 guest time from the host, you can set ``clock`` to ``rt`` instead,
4638 which provides a host monotonic clock if host support it. To even
4639 prevent the RTC from progressing during suspension, you can set
4640 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is
4641 recommended especially in icount mode in order to preserve
4642 determinism; however, note that in icount mode the speed of the
4643 virtual clock is variable and can in general differ from the host
4644 clock.
4645
4646 Enable ``driftfix`` (i386 targets only) if you experience time drift
4647 problems, specifically with Windows' ACPI HAL. This option will try
4648 to figure out how many timer interrupts were not processed by the
4649 Windows guest and will re-inject them.
4650ERST
blueswir15824d652009-03-28 06:44:27 +00004651
4652DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
Peter Maydellfa647902020-11-21 21:35:06 +00004653 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \
aliguoribc14ca22009-04-05 18:43:37 +00004654 " enable virtual instruction counter with 2^N clock ticks per\n" \
Victor CLEMENTf1f4b572015-05-29 17:14:05 +02004655 " instruction, enable aligning the host and virtual clocks\n" \
Peter Maydellfa647902020-11-21 21:35:06 +00004656 " or disable real time cpu sleeping, and optionally enable\n" \
4657 " record-and-replay mode\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004658SRST
Peter Maydellfa647902020-11-21 21:35:06 +00004659``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004660 Enable virtual instruction counter. The virtual cpu will execute one
4661 instruction every 2^N ns of virtual time. If ``auto`` is specified
4662 then the virtual cpu speed will be automatically adjusted to keep
4663 virtual time within a few seconds of real time.
4664
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004665 Note that while this option can give deterministic behavior, it does
4666 not provide cycle accurate emulation. Modern CPUs contain
4667 superscalar out of order cores with complex cache hierarchies. The
4668 number of instructions executed often has little or no correlation
4669 with actual performance.
4670
Peter Maydellfa647902020-11-21 21:35:06 +00004671 When the virtual cpu is sleeping, the virtual time will advance at
4672 default speed unless ``sleep=on`` is specified. With
4673 ``sleep=on``, the virtual time will jump to the next timer
4674 deadline instantly whenever the virtual cpu goes to sleep mode and
4675 will not advance if no timer is enabled. This behavior gives
4676 deterministic execution times from the guest point of view.
4677 The default if icount is enabled is ``sleep=off``.
4678 ``sleep=on`` cannot be used together with either ``shift=auto``
4679 or ``align=on``.
4680
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004681 ``align=on`` will activate the delay algorithm which will try to
4682 synchronise the host clock and the virtual clock. The goal is to
4683 have a guest running at the real frequency imposed by the shift
4684 option. Whenever the guest clock is behind the host clock and if
4685 ``align=on`` is specified then we print a message to the user to
4686 inform about the delay. Currently this option does not work when
4687 ``shift`` is ``auto``. Note: The sync algorithm will work for those
4688 shift values for which the guest clock runs ahead of the host clock.
4689 Typically this happens when the shift value is high (how high
Peter Maydellfa647902020-11-21 21:35:06 +00004690 depends on the host machine). The default if icount is enabled
4691 is ``align=off``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004692
Peter Maydellfa647902020-11-21 21:35:06 +00004693 When the ``rr`` option is specified deterministic record/replay is
4694 enabled. The ``rrfile=`` option must also be provided to
4695 specify the path to the replay log. In record mode data is written
4696 to this file, and in replay mode it is read back.
4697 If the ``rrsnapshot`` option is given then it specifies a VM snapshot
4698 name. In record mode, a new VM snapshot with the given name is created
4699 at the start of execution recording. In replay mode this option
4700 specifies the snapshot name used to load the initial VM state.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004701ERST
blueswir15824d652009-03-28 06:44:27 +00004702
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004703DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
Markus Armbruster7ad92702017-10-02 16:03:07 +02004704 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004705 " action when watchdog fires [default=reset]\n",
4706 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004707SRST
4708``-watchdog-action action``
4709 The action controls what QEMU will do when the watchdog timer
4710 expires. The default is ``reset`` (forcefully reset the guest).
4711 Other possible actions are: ``shutdown`` (attempt to gracefully
4712 shutdown the guest), ``poweroff`` (forcefully poweroff the guest),
4713 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the
4714 guest), ``debug`` (print a debug message and continue), or ``none``
4715 (do nothing).
4716
4717 Note that the ``shutdown`` action requires that the guest responds
4718 to ACPI signals, which it may not be able to do in the sort of
4719 situations where the watchdog would have expired, and thus
4720 ``-watchdog-action shutdown`` is not recommended for production use.
4721
4722 Examples:
4723
Paolo Bonzini5433af72022-09-10 13:44:47 +02004724 ``-device i6300esb -watchdog-action pause``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004725
4726ERST
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004727
blueswir15824d652009-03-28 06:44:27 +00004728DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
Blue Swirlad960902010-03-29 19:23:52 +00004729 "-echr chr set terminal escape character instead of ctrl-a\n",
4730 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004731SRST
4732``-echr numeric_ascii_value``
4733 Change the escape character used for switching to the monitor when
4734 using monitor and serial sharing. The default is ``0x01`` when using
4735 the ``-nographic`` option. ``0x01`` is equal to pressing
4736 ``Control-a``. You can select a different character from the ascii
4737 control keys where 1 through 26 map to Control-a through Control-z.
4738 For instance you could use the either of the following to change the
4739 escape character to Control-t.
4740
4741 ``-echr 0x14``; \ ``-echr 20``
4742
4743ERST
blueswir15824d652009-03-28 06:44:27 +00004744
blueswir15824d652009-03-28 06:44:27 +00004745DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004746 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \
4747 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \
Michael Tokarev7c601802015-02-10 22:40:47 +03004748 "-incoming unix:socketpath\n" \
4749 " prepare for incoming migration, listen on\n" \
4750 " specified protocol and socket address\n" \
4751 "-incoming fd:fd\n" \
Steve Sistare385f5102023-09-08 07:22:11 -07004752 "-incoming file:filename[,offset=offset]\n" \
Michael Tokarev7c601802015-02-10 22:40:47 +03004753 "-incoming exec:cmdline\n" \
4754 " accept incoming migration on given file descriptor\n" \
Dr. David Alan Gilbert15970512015-05-29 19:52:52 +01004755 " or from given external command\n" \
4756 "-incoming defer\n" \
4757 " wait for the URI to be specified via migrate_incoming\n",
Blue Swirlad960902010-03-29 19:23:52 +00004758 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004759SRST
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004760``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004761 \
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004762``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004763 Prepare for incoming migration, listen on a given tcp port.
4764
4765``-incoming unix:socketpath``
4766 Prepare for incoming migration, listen on a given unix socket.
4767
4768``-incoming fd:fd``
Steve Sistare2a9e2e52023-09-08 07:22:10 -07004769 Accept incoming migration from a given file descriptor.
4770
Steve Sistare385f5102023-09-08 07:22:11 -07004771``-incoming file:filename[,offset=offset]``
4772 Accept incoming migration from a given file starting at offset.
4773 offset allows the common size suffixes, or a 0x prefix, but not both.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004774
4775``-incoming exec:cmdline``
4776 Accept incoming migration as an output from specified external
4777 command.
4778
4779``-incoming defer``
4780 Wait for the URI to be specified via migrate\_incoming. The monitor
4781 can be used to change settings (such as migration parameters) prior
4782 to issuing the migrate\_incoming to allow the migration to begin.
4783ERST
blueswir15824d652009-03-28 06:44:27 +00004784
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304785DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
4786 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004787SRST
4788``-only-migratable``
4789 Only allow migratable devices. Devices will not be allowed to enter
4790 an unmigratable state.
4791ERST
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304792
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004793DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
Blue Swirlad960902010-03-29 19:23:52 +00004794 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004795SRST
4796``-nodefaults``
4797 Don't create default devices. Normally, QEMU sets the default
4798 devices like serial port, parallel port, virtual console, monitor
4799 device, VGA adapter, floppy and CD-ROM drive and others. The
4800 ``-nodefaults`` option will disable all those default devices.
4801ERST
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004802
blueswir15824d652009-03-28 06:44:27 +00004803#ifndef _WIN32
blueswir15824d652009-03-28 06:44:27 +00004804DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
Ian Jackson2c42f1e2017-09-15 18:10:44 +01004805 "-runas user change to user id user just before starting the VM\n" \
4806 " user can be numeric uid:gid instead\n",
Blue Swirlad960902010-03-29 19:23:52 +00004807 QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004808#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004809SRST
4810``-runas user``
4811 Immediately before starting guest execution, drop root privileges,
4812 switching to the specified user.
4813ERST
blueswir15824d652009-03-28 06:44:27 +00004814
blueswir15824d652009-03-28 06:44:27 +00004815DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
4816 "-prom-env variable=value\n"
Blue Swirlad960902010-03-29 19:23:52 +00004817 " set OpenBIOS nvram variables\n",
4818 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004819SRST
4820``-prom-env variable=value``
4821 Set OpenBIOS nvram variable to given value (PPC, SPARC only).
4822
4823 ::
4824
4825 qemu-system-sparc -prom-env 'auto-boot?=false' \
4826 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
4827
4828 ::
4829
4830 qemu-system-ppc -prom-env 'auto-boot?=false' \
4831 -prom-env 'boot-device=hd:2,\yaboot' \
4832 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
4833ERST
blueswir15824d652009-03-28 06:44:27 +00004834DEF("semihosting", 0, QEMU_OPTION_semihosting,
Michael Wallef7bbcfb2014-04-22 20:18:42 +02004835 "-semihosting semihosting mode\n",
Markus Armbruster9d49bcf2021-05-03 10:40:33 +02004836 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA |
Keith Packarda10b9d92021-01-08 22:42:52 +00004837 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004838SRST
4839``-semihosting``
Alex Bennée2da9d212023-01-24 18:01:13 +00004840 Enable :ref:`Semihosting` mode (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V only).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004841
Alex Bennée2da9d212023-01-24 18:01:13 +00004842 .. warning::
4843 Note that this allows guest direct access to the host filesystem, so
4844 should only be used with a trusted guest OS.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004845
4846 See the -semihosting-config option documentation for further
4847 information about the facilities this enables.
4848ERST
Liviu Ionescua38bb072014-12-11 12:07:48 +00004849DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
Peter Maydell52028612022-08-22 15:12:24 +01004850 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]\n" \
Leon Alraea59d31a2015-06-19 14:17:45 +01004851 " semihosting configuration\n",
Markus Armbruster9d49bcf2021-05-03 10:40:33 +02004852QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA |
Keith Packarda10b9d92021-01-08 22:42:52 +00004853QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004854SRST
Peter Maydell52028612022-08-22 15:12:24 +01004855``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]``
Alex Bennée2da9d212023-01-24 18:01:13 +00004856 Enable and configure :ref:`Semihosting` (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004857 only).
4858
Alex Bennée2da9d212023-01-24 18:01:13 +00004859 .. warning::
4860 Note that this allows guest direct access to the host filesystem, so
4861 should only be used with a trusted guest OS.
Keith Packarda10b9d92021-01-08 22:42:52 +00004862
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004863 ``target=native|gdb|auto``
4864 Defines where the semihosting calls will be addressed, to QEMU
4865 (``native``) or to GDB (``gdb``). The default is ``auto``, which
4866 means ``gdb`` during debug sessions and ``native`` otherwise.
4867
4868 ``chardev=str1``
4869 Send the output to a chardev backend output for native or auto
4870 output when not in gdb
4871
Peter Maydell52028612022-08-22 15:12:24 +01004872 ``userspace=on|off``
4873 Allows code running in guest userspace to access the semihosting
4874 interface. The default is that only privileged guest code can
4875 make semihosting calls. Note that setting ``userspace=on`` should
4876 only be used if all guest code is trusted (for example, in
4877 bare-metal test case code).
4878
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004879 ``arg=str1,arg=str2,...``
4880 Allows the user to pass input arguments, and can be used
4881 multiple times to build up a list. The old-style
4882 ``-kernel``/``-append`` method of passing a command line is
4883 still supported for backward compatibility. If both the
4884 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are
4885 specified, the former is passed to semihosting as it always
4886 takes precedence.
4887ERST
blueswir15824d652009-03-28 06:44:27 +00004888DEF("old-param", 0, QEMU_OPTION_old_param,
Blue Swirlad960902010-03-29 19:23:52 +00004889 "-old-param old param mode\n", QEMU_ARCH_ARM)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004890SRST
4891``-old-param``
4892 Old param mode (ARM only).
4893ERST
Stefan Weil95d5f082010-01-20 22:25:27 +01004894
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03004895DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01004896 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01004897 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
Eduardo Otubo2b716fa2017-03-01 23:17:29 +01004898 " Enable seccomp mode 2 system call filter (default 'off').\n" \
4899 " use 'obsolete' to allow obsolete system calls that are provided\n" \
4900 " by the kernel, but typically no longer used by modern\n" \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01004901 " C library implementations.\n" \
Philippe Mathieu-Daudéd42304b2021-03-03 19:46:43 +01004902 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \
4903 " to elevate privileges using set*uid|gid system calls.\n" \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01004904 " The value 'children' will deny set*uid|gid system calls for\n" \
Eduardo Otubo995a2262017-03-13 22:16:01 +01004905 " main QEMU process but will allow forks and execves to run unprivileged\n" \
4906 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
Philippe Mathieu-Daudéd42304b2021-03-03 19:46:43 +01004907 " blocking *fork and execve\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01004908 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03004909 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004910SRST
4911``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]``
4912 Enable Seccomp mode 2 system call filter. 'on' will enable syscall
4913 filtering and 'off' will disable it. The default is 'off'.
4914
4915 ``obsolete=string``
4916 Enable Obsolete system calls
4917
4918 ``elevateprivileges=string``
4919 Disable set\*uid\|gid system calls
4920
4921 ``spawn=string``
4922 Disable \*fork and execve
4923
4924 ``resourcecontrol=string``
4925 Disable process affinity and schedular priority
4926ERST
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03004927
Gerd Hoffmann715a6642009-10-14 10:39:28 +02004928DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
Paolo Bonzinie960a7e2022-04-14 10:57:21 -04004929 "-readconfig <file>\n"
4930 " read config file\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004931SRST
4932``-readconfig file``
4933 Read device configuration from file. This approach is useful when
4934 you want to spawn QEMU process with many command line options but
4935 you don't want to exceed the command line character limit.
4936ERST
Thomas Huth2feac452018-08-21 12:59:56 +02004937
Eduardo Habkostf29a5612012-05-02 13:07:29 -03004938DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
4939 "-no-user-config\n"
Eduardo Habkost3478eae2017-10-04 00:00:25 -03004940 " do not load default user-provided config files at startup\n",
Eduardo Habkostf29a5612012-05-02 13:07:29 -03004941 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004942SRST
4943``-no-user-config``
4944 The ``-no-user-config`` option makes QEMU not load any of the
4945 user-provided config files on sysconfdir.
4946ERST
Thomas Huth2feac452018-08-21 12:59:56 +02004947
Prerna Saxenaab6540d2010-08-09 11:48:32 +01004948DEF("trace", HAS_ARG, QEMU_OPTION_trace,
Paolo Bonzini10578a22016-01-07 16:55:26 +03004949 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
Lluís23d15e82011-08-31 20:31:31 +02004950 " specify tracing options\n",
Prerna Saxenaab6540d2010-08-09 11:48:32 +01004951 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004952SRST
4953``-trace [[enable=]pattern][,events=file][,file=file]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004954 .. include:: ../qemu-option-trace.rst.inc
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004955
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004956ERST
Lluís Vilanova42229a72017-07-24 17:28:22 +03004957DEF("plugin", HAS_ARG, QEMU_OPTION_plugin,
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02004958 "-plugin [file=]<file>[,<argname>=<argvalue>]\n"
Lluís Vilanova42229a72017-07-24 17:28:22 +03004959 " load a plugin\n",
4960 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004961SRST
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02004962``-plugin file=file[,argname=argvalue]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004963 Load a plugin.
4964
4965 ``file=file``
4966 Load the given plugin from a shared library file.
4967
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02004968 ``argname=argvalue``
4969 Argument passed to the plugin. (Can be given multiple times.)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004970ERST
Stefan Weil3dbf2c72010-01-16 18:19:44 +01004971
Markus Armbruster31e70d62013-02-13 19:49:37 +01004972HXCOMM Internal use
4973DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
4974DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
Anthony Liguoric7f0f3b2012-03-28 15:42:02 +02004975
Thomas Huth9ffcbe22023-07-03 09:44:47 +02004976#ifdef CONFIG_POSIX
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02004977DEF("run-with", HAS_ARG, QEMU_OPTION_run_with,
Thomas Huth9ffcbe22023-07-03 09:44:47 +02004978 "-run-with [async-teardown=on|off][,chroot=dir]\n"
4979 " Set miscellaneous QEMU process lifecycle options:\n"
4980 " async-teardown=on enables asynchronous teardown (Linux only)\n"
4981 " chroot=dir chroot to dir just before starting the VM\n",
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02004982 QEMU_ARCH_ALL)
4983SRST
Thomas Huth9ffcbe22023-07-03 09:44:47 +02004984``-run-with [async-teardown=on|off][,chroot=dir]``
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02004985 Set QEMU process lifecycle options.
4986
4987 ``async-teardown=on`` enables asynchronous teardown. A new process called
4988 "cleanup/<QEMU_PID>" will be created at startup sharing the address
4989 space with the main QEMU process, using clone. It will wait for the
4990 main QEMU process to terminate completely, and then exit. This allows
4991 QEMU to terminate very quickly even if the guest was huge, leaving the
4992 teardown of the address space to the cleanup process. Since the cleanup
4993 process shares the same cgroups as the main QEMU process, accounting is
4994 performed correctly. This only works if the cleanup process is not
4995 forcefully killed with SIGKILL before the main QEMU process has
4996 terminated completely.
Thomas Huth9ffcbe22023-07-03 09:44:47 +02004997
4998 ``chroot=dir`` can be used for doing a chroot to the specified directory
4999 immediately before starting the guest execution. This is especially useful
5000 in combination with -runas.
Claudio Imbrenda80bd81c2023-05-05 14:00:51 +02005001ERST
5002#endif
Claudio Imbrendac891c242022-08-12 15:34:53 +02005003
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04005004DEF("msg", HAS_ARG, QEMU_OPTION_msg,
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005005 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n"
Markus Armbrusterdeda4972019-10-10 10:15:08 +02005006 " control error message format\n"
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005007 " timestamp=on enables timestamps (default: off)\n"
5008 " guest-name=on enables guest name prefix but only if\n"
5009 " -name guest option is set (default: off)\n",
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04005010 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005011SRST
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005012``-msg [timestamp[=on|off]][,guest-name[=on|off]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005013 Control error message format.
5014
5015 ``timestamp=on|off``
5016 Prefix messages with a timestamp. Default is off.
Mario Smarduch2880ffb2020-06-26 13:19:00 -07005017
5018 ``guest-name=on|off``
5019 Prefix messages with guest name but only if -name guest option is set
5020 otherwise the option is ignored. Default is off.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005021ERST
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04005022
Amit Shahabfd9ce2014-06-20 18:56:08 +05305023DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
5024 "-dump-vmstate <file>\n"
5025 " Output vmstate information in JSON format to file.\n"
5026 " Use the scripts/vmstate-static-checker.py file to\n"
5027 " check for possible regressions in migration code\n"
Laurent Vivier23820532015-09-04 21:30:04 +02005028 " by comparing two such vmstate dumps.\n",
Amit Shahabfd9ce2014-06-20 18:56:08 +05305029 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005030SRST
5031``-dump-vmstate file``
5032 Dump json-encoded vmstate information for current machine type to
5033 file in file
5034ERST
Amit Shahabfd9ce2014-06-20 18:56:08 +05305035
Emilio G. Cota12df1892018-08-15 11:42:49 -04005036DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
5037 "-enable-sync-profile\n"
5038 " enable synchronization profiling\n",
5039 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005040SRST
5041``-enable-sync-profile``
5042 Enable synchronization profiling.
5043ERST
Emilio G. Cota12df1892018-08-15 11:42:49 -04005044
Ilya Leoshkevich5584e2d2023-01-12 16:20:13 +01005045#if defined(CONFIG_TCG) && defined(CONFIG_LINUX)
5046DEF("perfmap", 0, QEMU_OPTION_perfmap,
5047 "-perfmap generate a /tmp/perf-${pid}.map file for perf\n",
5048 QEMU_ARCH_ALL)
5049SRST
5050``-perfmap``
5051 Generate a map file for Linux perf tools that will allow basic profiling
5052 information to be broken down into basic blocks.
5053ERST
5054
5055DEF("jitdump", 0, QEMU_OPTION_jitdump,
5056 "-jitdump generate a jit-${pid}.dump file for perf\n",
5057 QEMU_ARCH_ALL)
5058SRST
5059``-jitdump``
5060 Generate a dump file for Linux perf tools that maps basic blocks to symbol
5061 names, line numbers and JITted code.
5062ERST
5063#endif
5064
Paolo Bonzini43f187a2017-01-04 13:50:37 +01005065DEFHEADING()
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02005066
5067DEFHEADING(Generic object creation:)
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01005068
5069DEF("object", HAS_ARG, QEMU_OPTION_object,
5070 "-object TYPENAME[,PROP1=VALUE1,...]\n"
5071 " create a new object of type TYPENAME setting properties\n"
5072 " in the order they are specified. Note that the 'id'\n"
5073 " property must be set. These objects are placed in the\n"
5074 " '/objects' path.\n",
5075 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005076SRST
5077``-object typename[,prop1=value1,...]``
5078 Create a new object of type typename setting properties in the order
5079 they are specified. Note that the 'id' property must be set. These
5080 objects are placed in the '/objects' path.
5081
David Hildenbrande92666b2023-09-06 14:04:55 +02005082 ``-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 +00005083 Creates a memory file backend object, which can be used to back
5084 the guest RAM with huge pages.
5085
5086 The ``id`` parameter is a unique ID that will be used to
Robert Hoo56c9f002021-04-22 16:42:02 +08005087 reference this memory region in other parameters, e.g. ``-numa``,
5088 ``-device nvdimm``, etc.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005089
5090 The ``size`` option provides the size of the memory region, and
Robert Hoo56c9f002021-04-22 16:42:02 +08005091 accepts common suffixes, e.g. ``500M``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005092
5093 The ``mem-path`` provides the path to either a shared memory or
5094 huge page filesystem mount.
5095
5096 The ``share`` boolean option determines whether the memory
5097 region is marked as private to QEMU, or shared. The latter
5098 allows a co-operating external process to access the QEMU memory
5099 region.
5100
5101 The ``share`` is also required for pvrdma devices due to
5102 limitations in the RDMA API provided by Linux.
5103
5104 Setting share=on might affect the ability to configure NUMA
5105 bindings for the memory backend under some circumstances, see
5106 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel
5107 source tree for additional details.
5108
5109 Setting the ``discard-data`` boolean option to on indicates that
5110 file contents can be destroyed when QEMU exits, to avoid
5111 unnecessarily flushing data to the backing file. Note that
5112 ``discard-data`` is only an optimization, and QEMU might not
5113 discard file contents if it aborts unexpectedly or is terminated
5114 using SIGKILL.
5115
5116 The ``merge`` boolean option enables memory merge, also known as
5117 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider
5118 the pages for memory deduplication.
5119
5120 Setting the ``dump`` boolean option to off excludes the memory
5121 from core dumps. This feature is also known as MADV\_DONTDUMP.
5122
5123 The ``prealloc`` boolean option enables memory preallocation.
5124
5125 The ``host-nodes`` option binds the memory range to a list of
5126 NUMA host nodes.
5127
5128 The ``policy`` option sets the NUMA policy to one of the
5129 following values:
5130
5131 ``default``
5132 default host policy
5133
5134 ``preferred``
5135 prefer the given host node list for allocation
5136
5137 ``bind``
5138 restrict memory allocation to the given host node list
5139
5140 ``interleave``
5141 interleave memory allocations across the given host node
5142 list
5143
5144 The ``align`` option specifies the base address alignment when
5145 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg
5146 ``2M``. Some backend store specified by ``mem-path`` requires an
5147 alignment different than the default one used by QEMU, eg the
5148 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
5149 such cases, users can specify the required alignment via this
5150 option.
5151
Alexander Graf4b870dc2023-04-03 22:14:21 +00005152 The ``offset`` option specifies the offset into the target file
5153 that the region starts at. You can use this parameter to back
5154 multiple regions with a single file.
5155
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005156 The ``pmem`` option specifies whether the backing file specified
5157 by ``mem-path`` is in host persistent memory that can be
5158 accessed using the SNIA NVM programming model (e.g. Intel
5159 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary
5160 operations to guarantee the persistence of its own writes to
5161 ``mem-path`` (e.g. in vNVDIMM label emulation and live
5162 migration). Also, we will map the backend-file with MAP\_SYNC
5163 flag, which ensures the file metadata is in sync for
5164 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC
5165 requires support from both the host kernel (since Linux kernel
5166 4.15) and the filesystem of ``mem-path`` mounted with DAX
5167 option.
5168
Stefan Hajnoczi86635aa2021-01-04 17:13:19 +00005169 The ``readonly`` option specifies whether the backing file is opened
5170 read-only or read-write (default).
5171
David Hildenbrande92666b2023-09-06 14:04:55 +02005172 The ``rom`` option specifies whether to create Read Only Memory
5173 (ROM) that cannot be modified by the VM. Any write attempts to such
5174 ROM will be denied. Most use cases want proper RAM instead of ROM.
5175 However, selected use cases, like R/O NVDIMMs, can benefit from
5176 ROM. If set to ``on``, create ROM; if set to ``off``, create
5177 writable RAM; if set to ``auto`` (default), the value of the
5178 ``readonly`` option is used. This option is primarily helpful when
5179 we want to have writable RAM in configurations that would
5180 traditionally create ROM before the ``rom`` option was introduced:
5181 VM templating, where we want to open a file readonly
5182 (``readonly=on``) and mark the memory to be private for QEMU
5183 (``share=off``). For this use case, we need writable RAM instead
5184 of ROM, and want to also set ``rom=off``.
5185
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005186 ``-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``
5187 Creates a memory backend object, which can be used to back the
5188 guest RAM. Memory backend objects offer more control than the
5189 ``-m`` option that is traditionally used to define guest RAM.
5190 Please refer to ``memory-backend-file`` for a description of the
5191 options.
5192
5193 ``-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``
5194 Creates an anonymous memory file backend object, which allows
5195 QEMU to share the memory with an external process (e.g. when
5196 using vhost-user). The memory is allocated with memfd and
5197 optional sealing. (Linux only)
5198
5199 The ``seal`` option creates a sealed-file, that will block
5200 further resizing the memory ('on' by default).
5201
5202 The ``hugetlb`` option specify the file to be created resides in
5203 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction
5204 with the ``hugetlb`` option, the ``hugetlbsize`` option specify
5205 the hugetlb page size on systems that support multiple hugetlb
5206 page sizes (it must be a power of 2 value supported by the
5207 system).
5208
5209 In some versions of Linux, the ``hugetlb`` option is
5210 incompatible with the ``seal`` option (requires at least Linux
5211 4.16).
5212
5213 Please refer to ``memory-backend-file`` for a description of the
5214 other options.
5215
5216 The ``share`` boolean option is on by default with memfd.
5217
Eric Auger6e6d8ac2023-11-21 16:44:00 +08005218 ``-object iommufd,id=id[,fd=fd]``
5219 Creates an iommufd backend which allows control of DMA mapping
5220 through the ``/dev/iommu`` device.
5221
5222 The ``id`` parameter is a unique ID which frontends (such as
5223 vfio-pci of vdpa) will use to connect with the iommufd backend.
5224
5225 The ``fd`` parameter is an optional pre-opened file descriptor
5226 resulting from ``/dev/iommu`` opening. Usually the iommufd is shared
5227 across all subsystems, bringing the benefit of centralized
5228 reference counting.
5229
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005230 ``-object rng-builtin,id=id``
5231 Creates a random number generator backend which obtains entropy
5232 from QEMU builtin functions. The ``id`` parameter is a unique ID
5233 that will be used to reference this entropy backend from the
5234 ``virtio-rng`` device. By default, the ``virtio-rng`` device
5235 uses this RNG backend.
5236
5237 ``-object rng-random,id=id,filename=/dev/random``
5238 Creates a random number generator backend which obtains entropy
5239 from a device on the host. The ``id`` parameter is a unique ID
5240 that will be used to reference this entropy backend from the
5241 ``virtio-rng`` device. The ``filename`` parameter specifies
5242 which file to obtain entropy from and if omitted defaults to
5243 ``/dev/urandom``.
5244
5245 ``-object rng-egd,id=id,chardev=chardevid``
5246 Creates a random number generator backend which obtains entropy
5247 from an external daemon running on the host. The ``id``
5248 parameter is a unique ID that will be used to reference this
5249 entropy backend from the ``virtio-rng`` device. The ``chardev``
5250 parameter is the unique ID of a character device backend that
5251 provides the connection to the RNG daemon.
5252
5253 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off``
5254 Creates a TLS anonymous credentials object, which can be used to
5255 provide TLS support on network backends. The ``id`` parameter is
5256 a unique ID which network backends will use to access the
5257 credentials. The ``endpoint`` is either ``server`` or ``client``
5258 depending on whether the QEMU network backend that uses the
5259 credentials will be acting as a client or as a server. If
5260 ``verify-peer`` is enabled (the default) then once the handshake
5261 is completed, the peer credentials will be verified, though this
5262 is a no-op for anonymous credentials.
5263
5264 The dir parameter tells QEMU where to find the credential files.
5265 For server endpoints, this directory may contain a file
5266 dh-params.pem providing diffie-hellman parameters to use for the
5267 TLS server. If the file is missing, QEMU will generate a set of
5268 DH parameters at startup. This is a computationally expensive
5269 operation that consumes random pool entropy, so it is
5270 recommended that a persistent set of parameters be generated
5271 upfront and saved.
5272
5273 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]``
5274 Creates a TLS Pre-Shared Keys (PSK) credentials object, which
5275 can be used to provide TLS support on network backends. The
5276 ``id`` parameter is a unique ID which network backends will use
5277 to access the credentials. The ``endpoint`` is either ``server``
5278 or ``client`` depending on whether the QEMU network backend that
5279 uses the credentials will be acting as a client or as a server.
5280 For clients only, ``username`` is the username which will be
5281 sent to the server. If omitted it defaults to "qemu".
5282
5283 The dir parameter tells QEMU where to find the keys file. It is
5284 called "dir/keys.psk" and contains "username:key" pairs. This
5285 file can most easily be created using the GnuTLS ``psktool``
5286 program.
5287
5288 For server endpoints, dir may also contain a file dh-params.pem
5289 providing diffie-hellman parameters to use for the TLS server.
5290 If the file is missing, QEMU will generate a set of DH
5291 parameters at startup. This is a computationally expensive
5292 operation that consumes random pool entropy, so it is
5293 recommended that a persistent set of parameters be generated up
5294 front and saved.
5295
5296 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id``
5297 Creates a TLS anonymous credentials object, which can be used to
5298 provide TLS support on network backends. The ``id`` parameter is
5299 a unique ID which network backends will use to access the
5300 credentials. The ``endpoint`` is either ``server`` or ``client``
5301 depending on whether the QEMU network backend that uses the
5302 credentials will be acting as a client or as a server. If
5303 ``verify-peer`` is enabled (the default) then once the handshake
5304 is completed, the peer credentials will be verified. With x509
5305 certificates, this implies that the clients must be provided
5306 with valid client certificates too.
5307
5308 The dir parameter tells QEMU where to find the credential files.
5309 For server endpoints, this directory may contain a file
5310 dh-params.pem providing diffie-hellman parameters to use for the
5311 TLS server. If the file is missing, QEMU will generate a set of
5312 DH parameters at startup. This is a computationally expensive
5313 operation that consumes random pool entropy, so it is
5314 recommended that a persistent set of parameters be generated
5315 upfront and saved.
5316
5317 For x509 certificate credentials the directory will contain
5318 further files providing the x509 certificates. The certificates
5319 must be stored in PEM format, in filenames ca-cert.pem,
5320 ca-crl.pem (optional), server-cert.pem (only servers),
5321 server-key.pem (only servers), client-cert.pem (only clients),
5322 and client-key.pem (only clients).
5323
5324 For the server-key.pem and client-key.pem files which contain
5325 sensitive private keys, it is possible to use an encrypted
5326 version by providing the passwordid parameter. This provides the
5327 ID of a previously created ``secret`` object containing the
5328 password for decryption.
5329
5330 The priority parameter allows to override the global default
5331 priority used by gnutls. This can be useful if the system
5332 administrator needs to use a weaker set of crypto priorities for
5333 QEMU without potentially forcing the weakness onto all
5334 applications. Or conversely if one wants wants a stronger
5335 default for QEMU than for all other applications, they can do
5336 this through this parameter. Its format is a gnutls priority
5337 string as described at
5338 https://gnutls.org/manual/html_node/Priority-Strings.html.
5339
Philippe Mathieu-Daudé993aec22018-10-11 20:21:11 +02005340 ``-object tls-cipher-suites,id=id,priority=priority``
5341 Creates a TLS cipher suites object, which can be used to control
5342 the TLS cipher/protocol algorithms that applications are permitted
5343 to use.
5344
5345 The ``id`` parameter is a unique ID which frontends will use to
5346 access the ordered list of permitted TLS cipher suites from the
5347 host.
5348
5349 The ``priority`` parameter allows to override the global default
5350 priority used by gnutls. This can be useful if the system
5351 administrator needs to use a weaker set of crypto priorities for
5352 QEMU without potentially forcing the weakness onto all
5353 applications. Or conversely if one wants wants a stronger
5354 default for QEMU than for all other applications, they can do
5355 this through this parameter. Its format is a gnutls priority
5356 string as described at
5357 https://gnutls.org/manual/html_node/Priority-Strings.html.
5358
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02005359 An example of use of this object is to control UEFI HTTPS Boot.
5360 The tls-cipher-suites object exposes the ordered list of permitted
5361 TLS cipher suites from the host side to the guest firmware, via
5362 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER
5363 objects. The firmware uses the IANA_TLS_CIPHER array for configuring
5364 guest-side TLS.
5365
5366 In the following example, the priority at which the host-side policy
5367 is retrieved is given by the ``priority`` property.
5368 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to
5369 refer to /etc/crypto-policies/back-ends/gnutls.config.
5370
5371 .. parsed-literal::
5372
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005373 # |qemu_system| \\
5374 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02005375 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0
5376
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005377 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]``
5378 Interval t can't be 0, this filter batches the packet delivery:
5379 all packets arriving in a given interval on netdev netdevid are
5380 delayed until the end of the interval. Interval is in
5381 microseconds. ``status`` is optional that indicate whether the
5382 netfilter is on (enabled) or off (disabled), the default status
5383 for netfilter will be 'on'.
5384
5385 queue all\|rx\|tx is an option that can be applied to any
5386 netfilter.
5387
5388 ``all``: the filter is attached both to the receive and the
5389 transmit queue of the netdev (default).
5390
5391 ``rx``: the filter is attached to the receive queue of the
5392 netdev, where it will receive packets sent to the netdev.
5393
5394 ``tx``: the filter is attached to the transmit queue of the
5395 netdev, where it will receive packets sent by the netdev.
5396
5397 position head\|tail\|id=<id> is an option to specify where the
5398 filter should be inserted in the filter list. It can be applied
5399 to any netfilter.
5400
5401 ``head``: the filter is inserted at the head of the filter list,
5402 before any existing filters.
5403
5404 ``tail``: the filter is inserted at the tail of the filter list,
5405 behind any existing filters (default).
5406
5407 ``id=<id>``: the filter is inserted before or behind the filter
5408 specified by <id>, see the insert option below.
5409
5410 insert behind\|before is an option to specify where to insert
5411 the new filter relative to the one specified with
5412 position=id=<id>. It can be applied to any netfilter.
5413
5414 ``before``: insert before the specified filter.
5415
5416 ``behind``: insert behind the specified filter (default).
5417
5418 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5419 filter-mirror on netdev netdevid,mirror net packet to
5420 chardevchardevid, if it has the vnet\_hdr\_support flag,
5421 filter-mirror will mirror packet with vnet\_hdr\_len.
5422
5423 ``-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]``
5424 filter-redirector on netdev netdevid,redirect filter's net
5425 packet to chardev chardevid,and redirect indev's packet to
5426 filter.if it has the vnet\_hdr\_support flag, filter-redirector
5427 will redirect packet with vnet\_hdr\_len. Create a
5428 filter-redirector we need to differ outdev id from indev id, id
5429 can not be the same. we can just use indev or outdev, but at
5430 least one of indev or outdev need to be specified.
5431
5432 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5433 Filter-rewriter is a part of COLO project.It will rewrite tcp
5434 packet to secondary from primary to keep secondary tcp
5435 connection,and rewrite tcp packet to primary from secondary make
5436 tcp packet can be handled by client.if it has the
5437 vnet\_hdr\_support flag, we can parse packet with vnet header.
5438
5439 usage: colo secondary: -object
5440 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object
5441 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object
5442 filter-rewriter,id=rew0,netdev=hn0,queue=all
5443
5444 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]``
5445 Dump the network traffic on netdev dev to the file specified by
5446 filename. At most len bytes (64k by default) per packet are
5447 stored. The file format is libpcap, so it can be analyzed with
5448 tools such as tcpdump or Wireshark.
5449
Zhang Chena2e5cb72020-06-24 09:20:41 +08005450 ``-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 +08005451 Colo-compare gets packet from primary\_in chardevid and
5452 secondary\_in, then compare whether the payload of primary packet
5453 and secondary packet are the same. If same, it will output
5454 primary packet to out\_dev, else it will notify COLO-framework to do
5455 checkpoint and send primary packet to out\_dev. In order to
5456 improve efficiency, we need to put the task of comparison in
5457 another iothread. If it has the vnet\_hdr\_support flag,
5458 colo compare will send/recv packet with vnet\_hdr\_len.
5459 The compare\_timeout=@var{ms} determines the maximum time of the
5460 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms}
5461 is to set the period of scanning expired primary node network packets.
5462 The max\_queue\_size=@var{size} is to set the max compare queue
5463 size depend on user environment.
5464 If user want to use Xen COLO, need to add the notify\_dev to
Zhang Chen9cc43c92020-03-18 16:23:19 +08005465 notify Xen colo-frame to do checkpoint.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005466
Zhang Chen2b28a7e2020-06-24 09:20:42 +08005467 COLO-compare must be used with the help of filter-mirror,
5468 filter-redirector and filter-rewriter.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005469
5470 ::
5471
5472 KVM COLO
5473
5474 primary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005475 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005476 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005477 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off
5478 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off
5479 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005480 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005481 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005482 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
5483 -object iothread,id=iothread1
5484 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
5485 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
5486 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
5487 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1
5488
5489 secondary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005490 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005491 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
5492 -chardev socket,id=red0,host=3.3.3.3,port=9003
5493 -chardev socket,id=red1,host=3.3.3.3,port=9004
5494 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
5495 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
5496
5497
5498 Xen COLO
5499
5500 primary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005501 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005502 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005503 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off
5504 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off
5505 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005506 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005507 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005508 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005509 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005510 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
5511 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
5512 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
5513 -object iothread,id=iothread1
Manos Pitsidianakis835f3642024-02-20 10:52:23 +02005514 -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 +00005515
5516 secondary:
Michael Tokarev7aa94e52024-01-07 14:24:59 +03005517 -netdev tap,id=hn0,vhost=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005518 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
5519 -chardev socket,id=red0,host=3.3.3.3,port=9003
5520 -chardev socket,id=red1,host=3.3.3.3,port=9004
5521 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
5522 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
5523
5524 If you want to know the detail of above command line, you can
5525 read the colo-compare git log.
5526
5527 ``-object cryptodev-backend-builtin,id=id[,queues=queues]``
Stefan Weil1e458f12022-10-30 11:59:44 +01005528 Creates a cryptodev backend which executes crypto operations from
5529 the QEMU cipher APIs. The id parameter is a unique ID that will
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005530 be used to reference this cryptodev backend from the
5531 ``virtio-crypto`` device. The queues parameter is optional,
5532 which specify the queue number of cryptodev backend, the default
5533 of queues is 1.
5534
Peter Maydell09ce5f22020-02-28 15:36:13 +00005535 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005536
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005537 # |qemu_system| \\
5538 [...] \\
5539 -object cryptodev-backend-builtin,id=cryptodev0 \\
5540 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005541 [...]
5542
5543 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]``
5544 Creates a vhost-user cryptodev backend, backed by a chardev
5545 chardevid. The id parameter is a unique ID that will be used to
5546 reference this cryptodev backend from the ``virtio-crypto``
5547 device. The chardev should be a unix domain socket backed one.
5548 The vhost-user uses a specifically defined protocol to pass
5549 vhost ioctl replacement messages to an application on the other
5550 end of the socket. The queues parameter is optional, which
5551 specify the queue number of cryptodev backend for multiqueue
5552 vhost-user, the default of queues is 1.
5553
Peter Maydell09ce5f22020-02-28 15:36:13 +00005554 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005555
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005556 # |qemu_system| \\
5557 [...] \\
5558 -chardev socket,id=chardev0,path=/path/to/socket \\
5559 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\
5560 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005561 [...]
5562
5563 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00005564 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005565 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]``
5566 Defines a secret to store a password, encryption key, or some
5567 other sensitive data. The sensitive data can either be passed
5568 directly via the data parameter, or indirectly via the file
5569 parameter. Using the data parameter is insecure unless the
5570 sensitive data is encrypted.
5571
5572 The sensitive data can be provided in raw format (the default),
5573 or base64. When encoded as JSON, the raw format only supports
5574 valid UTF-8 characters, so base64 is recommended for sending
5575 binary data. QEMU will convert from which ever format is
5576 provided to the format it needs internally. eg, an RBD password
5577 can be provided in raw format, even though it will be base64
5578 encoded when passed onto the RBD sever.
5579
5580 For added protection, it is possible to encrypt the data
5581 associated with a secret using the AES-256-CBC cipher. Use of
5582 encryption is indicated by providing the keyid and iv
5583 parameters. The keyid parameter provides the ID of a previously
5584 defined secret that contains the AES-256 decryption key. This
5585 key should be 32-bytes long and be base64 encoded. The iv
5586 parameter provides the random initialization vector used for
5587 encryption of this particular secret and should be a base64
5588 encrypted string of the 16-byte IV.
5589
5590 The simplest (insecure) usage is to provide the secret inline
5591
Peter Maydell09ce5f22020-02-28 15:36:13 +00005592 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005593
5594 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw
5595
5596 The simplest secure usage is to provide the secret via a file
5597
5598 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object
5599 secret,id=sec0,file=mypasswd.txt,format=raw
5600
5601 For greater security, AES-256-CBC should be used. To illustrate
5602 usage, consider the openssl command line tool which can encrypt
5603 the data. Note that when encrypting, the plaintext must be
5604 padded to the cipher block size (32 bytes) using the standard
5605 PKCS#5/6 compatible padding algorithm.
5606
5607 First a master key needs to be created in base64 encoding:
5608
5609 ::
5610
5611 # openssl rand -base64 32 > key.b64
5612 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
5613
5614 Each secret to be encrypted needs to have a random
5615 initialization vector generated. These do not need to be kept
5616 secret
5617
5618 ::
5619
5620 # openssl rand -base64 16 > iv.b64
5621 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
5622
5623 The secret to be defined can now be encrypted, in this case
5624 we're telling openssl to base64 encode the result, but it could
5625 be left as raw bytes if desired.
5626
5627 ::
5628
5629 # SECRET=$(printf "letmein" |
5630 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
5631
5632 When launching QEMU, create a master secret pointing to
5633 ``key.b64`` and specify that to be used to decrypt the user
5634 password. Pass the contents of ``iv.b64`` to the second secret
5635
Peter Maydell09ce5f22020-02-28 15:36:13 +00005636 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005637
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005638 # |qemu_system| \\
5639 -object secret,id=secmaster0,format=base64,file=key.b64 \\
5640 -object secret,id=sec0,keyid=secmaster0,format=base64,\\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005641 data=$SECRET,iv=$(<iv.b64)
5642
Dov Murik55cdf562021-11-11 10:00:43 +00005643 ``-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 +00005644 Create a Secure Encrypted Virtualization (SEV) guest object,
5645 which can be used to provide the guest memory encryption support
5646 on AMD processors.
5647
5648 When memory encryption is enabled, one of the physical address
5649 bit (aka the C-bit) is utilized to mark if a memory page is
5650 protected. The ``cbitpos`` is used to provide the C-bit
5651 position. The C-bit position is Host family dependent hence user
5652 must provide this value. On EPYC, the value should be 47.
5653
5654 When memory encryption is enabled, we loose certain bits in
5655 physical address space. The ``reduced-phys-bits`` is used to
5656 provide the number of bits we loose in physical address space.
5657 Similar to C-bit, the value is Host family dependent. On EPYC,
Tom Lendacky326e3012022-09-30 10:14:28 -05005658 a guest will lose a maximum of 1 bit, so the value should be 1.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005659
5660 The ``sev-device`` provides the device file to use for
5661 communicating with the SEV firmware running inside AMD Secure
5662 Processor. The default device is '/dev/sev'. If hardware
5663 supports memory encryption then /dev/sev devices are created by
5664 CCP driver.
5665
5666 The ``policy`` provides the guest policy to be enforced by the
5667 SEV firmware and restrict what configuration and operational
5668 commands can be performed on this guest by the hypervisor. The
5669 policy should be provided by the guest owner and is bound to the
5670 guest and cannot be changed throughout the lifetime of the
5671 guest. The default is 0.
5672
5673 If guest ``policy`` allows sharing the key with another SEV
5674 guest then ``handle`` can be use to provide handle of the guest
5675 from which to share the key.
5676
5677 The ``dh-cert-file`` and ``session-file`` provides the guest
5678 owner's Public Diffie-Hillman key defined in SEV spec. The PDH
5679 and session parameters are used for establishing a cryptographic
5680 session with the guest owner to negotiate keys used for
5681 attestation. The file must be encoded in base64.
5682
Dov Murik55cdf562021-11-11 10:00:43 +00005683 The ``kernel-hashes`` adds the hashes of given kernel/initrd/
5684 cmdline to a designated guest firmware page for measured Linux
5685 boot with -kernel. The default is off. (Since 6.2)
5686
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005687 e.g to launch a SEV guest
5688
Peter Maydell09ce5f22020-02-28 15:36:13 +00005689 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005690
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005691 # |qemu_system_x86| \\
5692 ...... \\
Tom Lendacky326e3012022-09-30 10:14:28 -05005693 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \\
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005694 -machine ...,memory-encryption=sev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005695 .....
5696
5697 ``-object authz-simple,id=id,identity=string``
5698 Create an authorization object that will control access to
5699 network services.
5700
5701 The ``identity`` parameter is identifies the user and its format
5702 depends on the network service that authorization object is
5703 associated with. For authorizing based on TLS x509 certificates,
5704 the identity must be the x509 distinguished name. Note that care
5705 must be taken to escape any commas in the distinguished name.
5706
5707 An example authorization object to validate a x509 distinguished
5708 name would look like:
5709
Peter Maydell09ce5f22020-02-28 15:36:13 +00005710 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005711
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005712 # |qemu_system| \\
5713 ... \\
5714 -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 +00005715 ...
5716
5717 Note the use of quotes due to the x509 distinguished name
5718 containing whitespace, and escaping of ','.
5719
Daniel P. Berrangé4d7beea2020-11-04 13:57:21 +00005720 ``-object authz-listfile,id=id,filename=path,refresh=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005721 Create an authorization object that will control access to
5722 network services.
5723
5724 The ``filename`` parameter is the fully qualified path to a file
5725 containing the access control list rules in JSON format.
5726
5727 An example set of rules that match against SASL usernames might
5728 look like:
5729
5730 ::
5731
5732 {
5733 "rules": [
5734 { "match": "fred", "policy": "allow", "format": "exact" },
5735 { "match": "bob", "policy": "allow", "format": "exact" },
5736 { "match": "danb", "policy": "deny", "format": "glob" },
5737 { "match": "dan*", "policy": "allow", "format": "exact" },
5738 ],
5739 "policy": "deny"
5740 }
5741
5742 When checking access the object will iterate over all the rules
5743 and the first rule to match will have its ``policy`` value
5744 returned as the result. If no rules match, then the default
5745 ``policy`` value is returned.
5746
5747 The rules can either be an exact string match, or they can use
5748 the simple UNIX glob pattern matching to allow wildcards to be
5749 used.
5750
5751 If ``refresh`` is set to true the file will be monitored and
5752 automatically reloaded whenever its content changes.
5753
5754 As with the ``authz-simple`` object, the format of the identity
5755 strings being matched depends on the network service, but is
5756 usually a TLS x509 distinguished name, or a SASL username.
5757
5758 An example authorization object to validate a SASL username
5759 would look like:
5760
Peter Maydell09ce5f22020-02-28 15:36:13 +00005761 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005762
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005763 # |qemu_system| \\
5764 ... \\
Daniel P. Berrangé4d7beea2020-11-04 13:57:21 +00005765 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005766 ...
5767
5768 ``-object authz-pam,id=id,service=string``
5769 Create an authorization object that will control access to
5770 network services.
5771
5772 The ``service`` parameter provides the name of a PAM service to
5773 use for authorization. It requires that a file
5774 ``/etc/pam.d/service`` exist to provide the configuration for
5775 the ``account`` subsystem.
5776
5777 An example authorization object to validate a TLS x509
5778 distinguished name would look like:
5779
Peter Maydell09ce5f22020-02-28 15:36:13 +00005780 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005781
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005782 # |qemu_system| \\
5783 ... \\
5784 -object authz-pam,id=auth0,service=qemu-vnc \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005785 ...
5786
5787 There would then be a corresponding config file for PAM at
5788 ``/etc/pam.d/qemu-vnc`` that contains:
5789
5790 ::
5791
5792 account requisite pam_listfile.so item=user sense=allow \
5793 file=/etc/qemu/vnc.allow
5794
5795 Finally the ``/etc/qemu/vnc.allow`` file would contain the list
Stefan Weil1e458f12022-10-30 11:59:44 +01005796 of x509 distinguished names that are permitted access
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005797
5798 ::
5799
5800 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB
5801
Stefano Garzarella1793ad02021-07-21 11:42:10 +02005802 ``-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 +00005803 Creates a dedicated event loop thread that devices can be
5804 assigned to. This is known as an IOThread. By default device
5805 emulation happens in vCPU threads or the main event loop thread.
5806 This can become a scalability bottleneck. IOThreads allow device
5807 emulation and I/O to run on other host CPUs.
5808
5809 The ``id`` parameter is a unique ID that will be used to
5810 reference this IOThread from ``-device ...,iothread=id``.
5811 Multiple devices can be assigned to an IOThread. Note that not
5812 all devices support an ``iothread`` parameter.
5813
5814 The ``query-iothreads`` QMP command lists IOThreads and reports
5815 their thread IDs so that the user can configure host CPU
5816 pinning/affinity.
5817
5818 IOThreads use an adaptive polling algorithm to reduce event loop
5819 latency. Instead of entering a blocking system call to monitor
5820 file descriptors and then pay the cost of being woken up when an
5821 event occurs, the polling algorithm spins waiting for events for
5822 a short time. The algorithm's default parameters are suitable
5823 for many cases but can be adjusted based on knowledge of the
5824 workload and/or host device latency.
5825
5826 The ``poll-max-ns`` parameter is the maximum number of
5827 nanoseconds to busy wait for events. Polling can be disabled by
5828 setting this value to 0.
5829
5830 The ``poll-grow`` parameter is the multiplier used to increase
5831 the polling time when the algorithm detects it is missing events
5832 due to not polling long enough.
5833
5834 The ``poll-shrink`` parameter is the divisor used to decrease
5835 the polling time when the algorithm detects it is spending too
5836 long polling without encountering events.
5837
Stefano Garzarella1793ad02021-07-21 11:42:10 +02005838 The ``aio-max-batch`` parameter is the maximum number of requests
5839 in a batch for the AIO engine, 0 means that the engine will use
5840 its default.
5841
5842 The IOThread parameters can be modified at run-time using the
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005843 ``qom-set`` command (where ``iothread1`` is the IOThread's
5844 ``id``):
5845
5846 ::
5847
5848 (qemu) qom-set /objects/iothread1 poll-max-ns 100000
5849ERST
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01005850
5851
Stefan Weil3dbf2c72010-01-16 18:19:44 +01005852HXCOMM This is the last statement. Insert new options before this line!
Paolo Bonzinifd5fc4b2021-05-17 07:34:21 -04005853
5854#undef DEF
5855#undef DEFHEADING
5856#undef ARCHHEADING