blob: 2c83390504d03c9041b071aae6248519f6b0f942 [file] [log] [blame]
Peter Maydell3c95fde2020-03-06 17:17:44 +00001HXCOMM Use DEFHEADING() to define headings in both help text and rST.
2HXCOMM Text between SRST and ERST is copied to the rST version and
3HXCOMM discarded from C version.
Blue Swirlad960902010-03-29 19:23:52 +00004HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to
5HXCOMM construct option structures, enums and help message for specified
6HXCOMM architectures.
Peter Maydell3c95fde2020-03-06 17:17:44 +00007HXCOMM HXCOMM can be used for comments, discarded from both rST and C.
blueswir15824d652009-03-28 06:44:27 +00008
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02009DEFHEADING(Standard options:)
blueswir15824d652009-03-28 06:44:27 +000010
11DEF("help", 0, QEMU_OPTION_h,
Blue Swirlad960902010-03-29 19:23:52 +000012 "-h or -help display this help and exit\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +000013SRST
14``-h``
15 Display help and exit
16ERST
blueswir15824d652009-03-28 06:44:27 +000017
pbrook9bd7e6d2009-04-07 22:58:45 +000018DEF("version", 0, QEMU_OPTION_version,
Blue Swirlad960902010-03-29 19:23:52 +000019 "-version display version information and exit\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +000020SRST
21``-version``
22 Display version information and exit
23ERST
pbrook9bd7e6d2009-04-07 22:58:45 +000024
Jan Kiszka80f52a62011-07-23 12:39:46 +020025DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
26 "-machine [type=]name[,prop[=value][,...]]\n"
Peter Maydell585f6032012-10-04 16:22:01 +010027 " selects emulated machine ('-machine help' for list)\n"
Jan Kiszka80f52a62011-07-23 12:39:46 +020028 " property accel=accel1[:accel2[:...]] selects accelerator\n"
Justin Terry (VM)d661d9a2018-01-22 13:07:46 -080029 " supported accelerators are kvm, xen, hax, hvf, whpx or tcg (default: tcg)\n"
Don Slutzd1048be2014-11-21 11:18:52 -050030 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
Luiz Capitulino8490fc72012-09-05 16:50:16 -030031 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
Le Tana52a7fd2014-08-16 13:55:40 +080032 " mem-merge=on|off controls memory merge support (default: on)\n"
Tony Krowiak2eb1cd02015-03-12 13:53:51 +010033 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
Alexander Graf9850c602015-02-23 13:56:42 +010034 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
Xiao Guangrong87252e12015-12-02 15:20:58 +080035 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
Greg Kurz902c0532016-02-18 12:32:25 +010036 " nvdimm=on|off controls NVDIMM support (default=off)\n"
Tao Xu244b3f42019-12-13 09:19:22 +080037 " memory-encryption=@var{} memory encryption object to use (default=none)\n"
38 " hmat=on|off controls ACPI HMAT support (default=off)\n",
Jan Kiszka80f52a62011-07-23 12:39:46 +020039 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +000040SRST
41``-machine [type=]name[,prop=value[,...]]``
42 Select the emulated machine by name. Use ``-machine help`` to list
43 available machines.
44
45 For architectures which aim to support live migration compatibility
46 across releases, each release will introduce a new versioned machine
47 type. For example, the 2.8.0 release introduced machine types
48 "pc-i440fx-2.8" and "pc-q35-2.8" for the x86\_64/i686 architectures.
49
50 To allow live migration of guests from QEMU version 2.8.0, to QEMU
51 version 2.9.0, the 2.9.0 version must support the "pc-i440fx-2.8"
52 and "pc-q35-2.8" machines too. To allow users live migrating VMs to
53 skip multiple intermediate releases when upgrading, new releases of
54 QEMU will support machine types from many previous versions.
55
56 Supported machine properties are:
57
58 ``accel=accels1[:accels2[:...]]``
59 This is used to enable an accelerator. Depending on the target
60 architecture, kvm, xen, hax, hvf, whpx or tcg can be available.
61 By default, tcg is used. If there is more than one accelerator
62 specified, the next one is used if the previous one fails to
63 initialize.
64
65 ``vmport=on|off|auto``
66 Enables emulation of VMWare IO port, for vmmouse etc. auto says
67 to select the value based on accel. For accel=xen the default is
68 off otherwise the default is on.
69
70 ``dump-guest-core=on|off``
71 Include guest memory in a core dump. The default is on.
72
73 ``mem-merge=on|off``
74 Enables or disables memory merge support. This feature, when
75 supported by the host, de-duplicates identical memory pages
76 among VMs instances (enabled by default).
77
78 ``aes-key-wrap=on|off``
79 Enables or disables AES key wrapping support on s390-ccw hosts.
80 This feature controls whether AES wrapping keys will be created
81 to allow execution of AES cryptographic functions. The default
82 is on.
83
84 ``dea-key-wrap=on|off``
85 Enables or disables DEA key wrapping support on s390-ccw hosts.
86 This feature controls whether DEA wrapping keys will be created
87 to allow execution of DEA cryptographic functions. The default
88 is on.
89
90 ``nvdimm=on|off``
91 Enables or disables NVDIMM support. The default is off.
92
Peter Maydelle2fcbf42020-03-06 10:07:14 +000093 ``memory-encryption=``
94 Memory encryption object to use. The default is none.
95
96 ``hmat=on|off``
97 Enables or disables ACPI Heterogeneous Memory Attribute Table
98 (HMAT) support. The default is off.
99ERST
blueswir15824d652009-03-28 06:44:27 +0000100
Jan Kiszka80f52a62011-07-23 12:39:46 +0200101HXCOMM Deprecated by -machine
102DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
103
blueswir15824d652009-03-28 06:44:27 +0000104DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
Peter Maydell585f6032012-10-04 16:22:01 +0100105 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000106SRST
107``-cpu model``
108 Select CPU model (``-cpu help`` for list and additional feature
109 selection)
110ERST
blueswir15824d652009-03-28 06:44:27 +0000111
KONRAD Frederic8d4e9142017-02-23 18:29:08 +0000112DEF("accel", HAS_ARG, QEMU_OPTION_accel,
Paolo Bonzinife174132019-11-13 15:16:44 +0100113 "-accel [accel=]accelerator[,prop[=value][,...]]\n"
Justin Terry (VM)d661d9a2018-01-22 13:07:46 -0800114 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n"
Paolo Bonzini46472d82019-11-13 10:56:53 +0100115 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n"
Paolo Bonzini11bc4a12019-11-13 10:56:53 +0100116 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n"
Paolo Bonzini23b08982019-11-13 10:56:53 +0100117 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n"
Paolo Bonzinife174132019-11-13 15:16:44 +0100118 " tb-size=n (TCG translation block cache size)\n"
Eduardo Habkost0b3c5c82018-06-11 16:56:07 -0300119 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000120SRST
121``-accel name[,prop=value[,...]]``
122 This is used to enable an accelerator. Depending on the target
123 architecture, kvm, xen, hax, hvf, whpx or tcg can be available. By
124 default, tcg is used. If there is more than one accelerator
125 specified, the next one is used if the previous one fails to
126 initialize.
127
128 ``igd-passthru=on|off``
129 When Xen is in use, this option controls whether Intel
130 integrated graphics devices can be passed through to the guest
131 (default=off)
132
133 ``kernel-irqchip=on|off|split``
134 Controls KVM in-kernel irqchip support. The default is full
135 acceleration of the interrupt controllers. On x86, split irqchip
136 reduces the kernel attack surface, at a performance cost for
137 non-MSI interrupts. Disabling the in-kernel irqchip completely
138 is not recommended except for debugging purposes.
139
140 ``kvm-shadow-mem=size``
141 Defines the size of the KVM shadow MMU.
142
143 ``tb-size=n``
144 Controls the size (in MiB) of the TCG translation block cache.
145
146 ``thread=single|multi``
147 Controls number of TCG threads. When the TCG is multi-threaded
148 there will be one thread per vCPU therefor taking advantage of
149 additional host cores. The default is to enable multi-threading
150 where both the back-end and front-ends support it and no
151 incompatible TCG features have been enabled (e.g.
152 icount/replay).
153ERST
KONRAD Frederic8d4e9142017-02-23 18:29:08 +0000154
blueswir15824d652009-03-28 06:44:27 +0000155DEF("smp", HAS_ARG, QEMU_OPTION_smp,
Like Xu1b458422019-06-20 13:45:25 +0800156 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n"
Jes Sorensen6be68d72009-07-23 17:03:42 +0200157 " set the number of CPUs to 'n' [default=1]\n"
158 " maxcpus= maximum number of total cpus, including\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -0700159 " offline CPUs for hotplug, etc\n"
Like Xu1b458422019-06-20 13:45:25 +0800160 " cores= number of CPU cores on one socket (for PC, it's on one die)\n"
Andre Przywara58a04db2009-08-28 10:49:57 +0200161 " threads= number of threads on one CPU core\n"
Like Xu1b458422019-06-20 13:45:25 +0800162 " dies= number of CPU dies on one socket (for PC only)\n"
Blue Swirlad960902010-03-29 19:23:52 +0000163 " sockets= number of discrete sockets in the system\n",
164 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000165SRST
166``-smp [cpus=]n[,cores=cores][,threads=threads][,dies=dies][,sockets=sockets][,maxcpus=maxcpus]``
167 Simulate an SMP system with n CPUs. On the PC target, up to 255 CPUs
168 are supported. On Sparc32 target, Linux limits the number of usable
169 CPUs to 4. For the PC target, the number of cores per die, the
170 number of threads per cores, the number of dies per packages and the
171 total number of sockets can be specified. Missing values will be
172 computed. If any on the three values is given, the total number of
173 CPUs n can be omitted. maxcpus specifies the maximum number of
174 hotpluggable CPUs.
175ERST
blueswir15824d652009-03-28 06:44:27 +0000176
aliguori268a3622009-04-21 22:30:27 +0000177DEF("numa", HAS_ARG, QEMU_OPTION_numa,
Tao Xu244b3f42019-12-13 09:19:22 +0800178 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n"
179 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n"
Igor Mammedov2d19c652017-11-28 15:53:58 +0100180 "-numa dist,src=source,dst=destination,val=distance\n"
Liu Jingqi9b12dfa2019-12-13 09:19:23 +0800181 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n"
Liu Jingqic412a482019-12-13 09:19:24 +0800182 "-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"
183 "-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 +0100184 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000185SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000186``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]``
187 \
188``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]``
189 \
190``-numa dist,src=source,dst=destination,val=distance``
191 \
192``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]``
193 \
194``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=tpye[,latency=lat][,bandwidth=bw]``
195 \
196``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000197 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA
198 distance from a source node to a destination node. Set the ACPI
199 Heterogeneous Memory Attributes for the given nodes.
200
201 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and
202 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a
203 contiguous range of CPU indexes (or a single VCPU if lastcpu is
204 omitted). A non-contiguous set of VCPUs can be represented by
205 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is
206 omitted on all nodes, VCPUs are automatically split between them.
207
208 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a
209 NUMA node:
210
211 ::
212
213 -numa node,cpus=0-2,cpus=5
214
215 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option
216 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to
217 assign CPU objects to a node using topology layout properties of
218 CPU. The set of properties is machine specific, and depends on used
219 machine type/'\ ``smp``\ ' options. It could be queried with
220 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ '
221 property specifies node to which CPU object will be assigned, it's
222 required for node to be declared with '\ ``node``\ ' option before
223 it's used with '\ ``cpu``\ ' option.
224
225 For example:
226
227 ::
228
229 -M pc \
230 -smp 1,sockets=2,maxcpus=2 \
231 -numa node,nodeid=0 -numa node,nodeid=1 \
232 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
233
Igor Mammedov32a354d2020-06-09 09:56:35 -0400234 Legacy '\ ``mem``\ ' assigns a given RAM amount to a node (not supported
235 for 5.1 and newer machine types). '\ ``memdev``\ ' assigns RAM from
236 a given memory backend device to a node. If '\ ``mem``\ ' and
237 '\ ``memdev``\ ' are omitted in all nodes, RAM is split equally between them.
238
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000239
240 '\ ``mem``\ ' and '\ ``memdev``\ ' are mutually exclusive.
241 Furthermore, if one node uses '\ ``memdev``\ ', all of them have to
242 use it.
243
244 '\ ``initiator``\ ' is an additional option that points to an
245 initiator NUMA node that has best performance (the lowest latency or
246 largest bandwidth) to this NUMA node. Note that this option can be
247 set only when the machine property 'hmat' is set to 'on'.
248
249 Following example creates a machine with 2 NUMA nodes, node 0 has
250 CPU. node 1 has only memory, and its initiator is node 0. Note that
251 because node 0 has CPU, by default the initiator of node 0 is itself
252 and must be itself.
253
254 ::
255
256 -machine hmat=on \
257 -m 2G,slots=2,maxmem=4G \
258 -object memory-backend-ram,size=1G,id=m0 \
259 -object memory-backend-ram,size=1G,id=m1 \
260 -numa node,nodeid=0,memdev=m0 \
261 -numa node,nodeid=1,memdev=m1,initiator=0 \
262 -smp 2,sockets=2,maxcpus=2 \
263 -numa cpu,node-id=0,socket-id=0 \
264 -numa cpu,node-id=0,socket-id=1
265
266 source and destination are NUMA node IDs. distance is the NUMA
267 distance from source to destination. The distance from a node to
268 itself is always 10. If any pair of nodes is given a distance, then
269 all pairs must be given distances. Although, when distances are only
270 given in one direction for each pair of nodes, then the distances in
271 the opposite directions are assumed to be the same. If, however, an
272 asymmetrical pair of distances is given for even one node pair, then
273 all node pairs must be provided distance values for both directions,
274 even when they are symmetrical. When a node is unreachable from
275 another node, set the pair's distance to 255.
276
277 Note that the -``numa`` option doesn't allocate any of the specified
278 resources, it just assigns existing resources to NUMA nodes. This
279 means that one still has to use the ``-m``, ``-smp`` options to
280 allocate RAM and VCPUs respectively.
281
282 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth
283 Information between initiator and target NUMA nodes in ACPI
284 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can
285 create memory requests, usually it has one or more processors.
286 Target NUMA node contains addressable memory.
287
288 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is
289 the memory hierarchy of the target NUMA node: if hierarchy is
290 'memory', the structure represents the memory performance; if
291 hierarchy is 'first-level\|second-level\|third-level', this
292 structure represents aggregated performance of memory side caches
293 for each domain. type of 'data-type' is type of data represented by
294 this structure instance: if 'hierarchy' is 'memory', 'data-type' is
295 'access\|read\|write' latency or 'access\|read\|write' bandwidth of
296 the target memory; if 'hierarchy' is
297 'first-level\|second-level\|third-level', 'data-type' is
298 'access\|read\|write' hit latency or 'access\|read\|write' hit
299 bandwidth of the target memory side cache.
300
301 lat is latency value in nanoseconds. bw is bandwidth value, the
302 possible value and units are NUM[M\|G\|T], mean that the bandwidth
303 value are NUM byte per second (or MB/s, GB/s or TB/s depending on
304 used suffix). Note that if latency or bandwidth value is 0, means
305 the corresponding latency or bandwidth information is not provided.
306
307 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory
308 belongs. size is the size of memory side cache in bytes. level is
309 the cache level described in this structure, note that the cache
310 level 0 should not be used with '\ ``hmat-cache``\ ' option.
311 associativity is the cache associativity, the possible value is
312 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy
313 is the write policy. line is the cache Line size in bytes.
314
315 For example, the following options describe 2 NUMA nodes. Node 0 has
316 2 cpus and a ram, node 1 has only a ram. The processors in node 0
317 access memory in node 0 with access-latency 5 nanoseconds,
318 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access
319 memory in NUMA node 1 with access-latency 10 nanoseconds,
320 access-bandwidth is 100 MB/s. And for memory side cache information,
321 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB,
322 policy is write-back, the cache Line size is 8 bytes:
323
324 ::
325
326 -machine hmat=on \
327 -m 2G \
328 -object memory-backend-ram,size=1G,id=m0 \
329 -object memory-backend-ram,size=1G,id=m1 \
330 -smp 2 \
331 -numa node,nodeid=0,memdev=m0 \
332 -numa node,nodeid=1,memdev=m1,initiator=0 \
333 -numa cpu,node-id=0,socket-id=0 \
334 -numa cpu,node-id=0,socket-id=1 \
335 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \
336 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \
337 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \
338 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \
339 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \
340 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8
341ERST
aliguori268a3622009-04-21 22:30:27 +0000342
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100343DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
344 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
345 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000346SRST
347``-add-fd fd=fd,set=set[,opaque=opaque]``
348 Add a file descriptor to an fd set. Valid options are:
349
350 ``fd=fd``
351 This option defines the file descriptor of which a duplicate is
352 added to fd set. The file descriptor cannot be stdin, stdout, or
353 stderr.
354
355 ``set=set``
356 This option defines the ID of the fd set to add the file
357 descriptor to.
358
359 ``opaque=opaque``
360 This option defines a free-form string that can be used to
361 describe fd.
362
363 You can open an image using pre-opened file descriptors from an fd
364 set:
365
366 .. parsed-literal::
367
Laszlo Ersek353a06b2020-09-08 19:21:11 +0200368 |qemu_system| \\
369 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\
370 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000371 -drive file=/dev/fdset/2,index=0,media=disk
372ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100373
374DEF("set", HAS_ARG, QEMU_OPTION_set,
375 "-set group.id.arg=value\n"
376 " set <arg> parameter for item <id> of type <group>\n"
377 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000378SRST
379``-set group.id.arg=value``
380 Set parameter arg for item id of type group
381ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100382
383DEF("global", HAS_ARG, QEMU_OPTION_global,
Paolo Bonzini3751d7c2015-04-09 14:16:19 +0200384 "-global driver.property=value\n"
385 "-global driver=driver,property=property,value=value\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100386 " set a global default for a driver property\n",
387 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000388SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000389``-global driver.prop=value``
390 \
391``-global driver=driver,property=property,value=value``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000392 Set default value of driver's property prop to value, e.g.:
393
394 .. parsed-literal::
395
396 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img
397
398 In particular, you can use this to set driver properties for devices
399 which are created automatically by the machine model. To create a
400 device which is not created automatically and set properties on it,
401 use -``device``.
402
403 -global driver.prop=value is shorthand for -global
404 driver=driver,property=prop,value=value. The longhand syntax works
405 even when driver contains a dot.
406ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100407
408DEF("boot", HAS_ARG, QEMU_OPTION_boot,
409 "-boot [order=drives][,once=drives][,menu=on|off]\n"
Amos Kongc8a6ae82013-03-19 14:23:27 +0800410 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100411 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
412 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
413 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
414 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
415 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000416SRST
417``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]``
418 Specify boot order drives as a string of drive letters. Valid drive
419 letters depend on the target architecture. The x86 PC uses: a, b
420 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p
421 (Etherboot from network adapter 1-4), hard disk boot is the default.
422 To apply a particular boot order only on the first startup, specify
423 it via ``once``. Note that the ``order`` or ``once`` parameter
424 should not be used together with the ``bootindex`` property of
425 devices, since the firmware implementations normally do not support
426 both at the same time.
427
428 Interactive boot menus/prompts can be enabled via ``menu=on`` as far
429 as firmware/BIOS supports them. The default is non-interactive boot.
430
431 A splash picture could be passed to bios, enabling user to show it
432 as logo, when option splash=sp\_name is given and menu=on, If
433 firmware/BIOS supports them. Currently Seabios for X86 system
434 support it. limitation: The splash file could be a jpeg file or a
435 BMP file in 24 BPP format(true color). The resolution should be
436 supported by the SVGA mode, so the recommended is 320x240, 640x480,
437 800x640.
438
439 A timeout could be passed to bios, guest will pause for rb\_timeout
440 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will
441 not reboot, qemu passes '-1' to bios by default. Currently Seabios
442 for X86 system support it.
443
444 Do strict boot via ``strict=on`` as far as firmware/BIOS supports
445 it. This only effects when boot priority is changed by bootindex
446 options. The default is non-strict boot.
447
Peter Maydell09ce5f22020-02-28 15:36:13 +0000448 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000449
450 # try to boot from network first, then from hard disk
451 |qemu_system_x86| -boot order=nc
452 # boot from CD-ROM first, switch back to default order after reboot
453 |qemu_system_x86| -boot once=d
454 # boot with a splash picture for 5 seconds.
455 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000
456
457 Note: The legacy format '-boot drives' is still supported but its
458 use is discouraged as it may be removed from future versions.
459ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100460
461DEF("m", HAS_ARG, QEMU_OPTION_m,
Michael Tokarev89f3ea22016-11-10 17:51:32 +0300462 "-m [size=]megs[,slots=n,maxmem=size]\n"
Igor Mammedov6e1d3c12013-11-27 01:27:35 +0100463 " configure guest RAM\n"
Alexander Graf0daba1f2015-06-05 11:05:03 +0200464 " size: initial amount of guest memory\n"
Igor Mammedovc270fb92014-06-02 15:25:02 +0200465 " slots: number of hotplug slots (default: none)\n"
Matthew Rosatob6fe0122014-08-28 11:25:33 -0400466 " maxmem: maximum amount of guest memory (default: none)\n"
467 "NOTE: Some architectures might enforce a specific granularity\n",
Igor Mammedov6e1d3c12013-11-27 01:27:35 +0100468 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000469SRST
470``-m [size=]megs[,slots=n,maxmem=size]``
471 Sets guest startup RAM size to megs megabytes. Default is 128 MiB.
472 Optionally, a suffix of "M" or "G" can be used to signify a value in
473 megabytes or gigabytes respectively. Optional pair slots, maxmem
474 could be used to set amount of hotpluggable memory slots and maximum
475 amount of memory. Note that maxmem must be aligned to the page size.
476
477 For example, the following command-line sets the guest startup RAM
478 size to 1GB, creates 3 slots to hotplug additional memory and sets
479 the maximum memory the guest can reach to 4GB:
480
481 .. parsed-literal::
482
483 |qemu_system| -m 1G,slots=3,maxmem=4G
484
485 If slots and maxmem are not specified, memory hotplug won't be
486 enabled and the guest startup RAM will never increase.
487ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100488
489DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
490 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000491SRST
492``-mem-path path``
493 Allocate guest RAM from a temporarily created file in path.
494ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100495
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100496DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
497 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
498 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000499SRST
500``-mem-prealloc``
501 Preallocate memory when using -mem-path.
502ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100503
504DEF("k", HAS_ARG, QEMU_OPTION_k,
505 "-k language use keyboard layout (for example 'fr' for French)\n",
506 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000507SRST
508``-k language``
509 Use keyboard layout language (for example ``fr`` for French). This
510 option is only needed where it is not easy to get raw PC keycodes
511 (e.g. on Macs, with some X11 servers or with a VNC or curses
512 display). You don't normally need to use it on PC/Linux or
513 PC/Windows hosts.
514
515 The available layouts are:
516
517 ::
518
519 ar de-ch es fo fr-ca hu ja mk no pt-br sv
520 da en-gb et fr fr-ch is lt nl pl ru th
521 de en-us fi fr-be hr it lv nl-be pt sl tr
522
523 The default is ``en-us``.
524ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100525
526
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100527HXCOMM Deprecated by -audiodev
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100528DEF("audio-help", 0, QEMU_OPTION_audio_help,
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100529 "-audio-help show -audiodev equivalent of the currently specified audio settings\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100530 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000531SRST
532``-audio-help``
533 Will show the -audiodev equivalent of the currently specified
534 (deprecated) environment variables.
535ERST
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100536
537DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev,
538 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n"
539 " specifies the audio backend to use\n"
540 " id= identifier of the backend\n"
541 " timer-period= timer period in microseconds\n"
Kővágó, Zoltán8efac072019-10-13 21:57:58 +0200542 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100543 " in|out.fixed-settings= use fixed settings for host audio\n"
544 " in|out.frequency= frequency to use with fixed settings\n"
545 " in|out.channels= number of channels to use with fixed settings\n"
546 " in|out.format= sample format to use with fixed settings\n"
Volker Rümelin49f77e62020-03-08 20:33:21 +0100547 " valid values: s8, s16, s32, u8, u16, u32, f32\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100548 " in|out.voices= number of voices to use\n"
Stefan Hajnoczi86247252019-09-18 10:53:33 +0100549 " in|out.buffer-length= length of buffer in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100550 "-audiodev none,id=id,[,prop[=value][,...]]\n"
551 " dummy driver that discards all output\n"
552#ifdef CONFIG_AUDIO_ALSA
553 "-audiodev alsa,id=id[,prop[=value][,...]]\n"
554 " in|out.dev= name of the audio device to use\n"
Stefan Hajnoczidfc54342019-09-18 10:53:35 +0100555 " in|out.period-length= length of period in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100556 " in|out.try-poll= attempt to use poll mode\n"
557 " threshold= threshold (in microseconds) when playback starts\n"
558#endif
559#ifdef CONFIG_AUDIO_COREAUDIO
560 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n"
561 " in|out.buffer-count= number of buffers\n"
562#endif
563#ifdef CONFIG_AUDIO_DSOUND
564 "-audiodev dsound,id=id[,prop[=value][,...]]\n"
565 " latency= add extra latency to playback in microseconds\n"
566#endif
567#ifdef CONFIG_AUDIO_OSS
568 "-audiodev oss,id=id[,prop[=value][,...]]\n"
569 " in|out.dev= path of the audio device to use\n"
570 " in|out.buffer-count= number of buffers\n"
571 " in|out.try-poll= attempt to use poll mode\n"
572 " try-mmap= try using memory mapped access\n"
573 " exclusive= open device in exclusive mode\n"
574 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n"
575#endif
576#ifdef CONFIG_AUDIO_PA
577 "-audiodev pa,id=id[,prop[=value][,...]]\n"
578 " server= PulseAudio server address\n"
579 " in|out.name= source/sink device name\n"
Stefan Hajnoczi14d4f012019-10-04 13:56:41 +0100580 " in|out.latency= desired latency in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100581#endif
582#ifdef CONFIG_AUDIO_SDL
583 "-audiodev sdl,id=id[,prop[=value][,...]]\n"
584#endif
585#ifdef CONFIG_SPICE
586 "-audiodev spice,id=id[,prop[=value][,...]]\n"
587#endif
588 "-audiodev wav,id=id[,prop[=value][,...]]\n"
589 " path= path of wav file to record\n",
590 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000591SRST
592``-audiodev [driver=]driver,id=id[,prop[=value][,...]]``
593 Adds a new audio backend driver identified by id. There are global
594 and driver specific properties. Some values can be set differently
595 for input and output, they're marked with ``in|out.``. You can set
596 the input's property with ``in.prop`` and the output's property with
597 ``out.prop``. For example:
598
599 ::
600
601 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000
602 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified
603
604 NOTE: parameter validation is known to be incomplete, in many cases
605 specifying an invalid option causes QEMU to print an error message
606 and continue emulation without sound.
607
608 Valid global options are:
609
610 ``id=identifier``
611 Identifies the audio backend.
612
613 ``timer-period=period``
614 Sets the timer period used by the audio subsystem in
615 microseconds. Default is 10000 (10 ms).
616
617 ``in|out.mixing-engine=on|off``
618 Use QEMU's mixing engine to mix all streams inside QEMU and
619 convert audio formats when not supported by the backend. When
620 off, fixed-settings must be off too. Note that disabling this
621 option means that the selected backend must support multiple
622 streams and the audio formats used by the virtual cards,
623 otherwise you'll get no sound. It's not recommended to disable
624 this option unless you want to use 5.1 or 7.1 audio, as mixing
625 engine only supports mono and stereo audio. Default is on.
626
627 ``in|out.fixed-settings=on|off``
628 Use fixed settings for host audio. When off, it will change
629 based on how the guest opens the sound card. In this case you
630 must not specify frequency, channels or format. Default is on.
631
632 ``in|out.frequency=frequency``
633 Specify the frequency to use when using fixed-settings. Default
634 is 44100Hz.
635
636 ``in|out.channels=channels``
637 Specify the number of channels to use when using fixed-settings.
638 Default is 2 (stereo).
639
640 ``in|out.format=format``
641 Specify the sample format to use when using fixed-settings.
642 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``,
Volker Rümelin49f77e62020-03-08 20:33:21 +0100643 ``u32``, ``f32``. Default is ``s16``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000644
645 ``in|out.voices=voices``
646 Specify the number of voices to use. Default is 1.
647
648 ``in|out.buffer-length=usecs``
649 Sets the size of the buffer in microseconds.
650
651``-audiodev none,id=id[,prop[=value][,...]]``
652 Creates a dummy backend that discards all outputs. This backend has
653 no backend specific properties.
654
655``-audiodev alsa,id=id[,prop[=value][,...]]``
656 Creates backend using the ALSA. This backend is only available on
657 Linux.
658
659 ALSA specific options are:
660
661 ``in|out.dev=device``
662 Specify the ALSA device to use for input and/or output. Default
663 is ``default``.
664
665 ``in|out.period-length=usecs``
666 Sets the period length in microseconds.
667
668 ``in|out.try-poll=on|off``
669 Attempt to use poll mode with the device. Default is on.
670
671 ``threshold=threshold``
672 Threshold (in microseconds) when playback starts. Default is 0.
673
674``-audiodev coreaudio,id=id[,prop[=value][,...]]``
675 Creates a backend using Apple's Core Audio. This backend is only
676 available on Mac OS and only supports playback.
677
678 Core Audio specific options are:
679
680 ``in|out.buffer-count=count``
681 Sets the count of the buffers.
682
683``-audiodev dsound,id=id[,prop[=value][,...]]``
684 Creates a backend using Microsoft's DirectSound. This backend is
685 only available on Windows and only supports playback.
686
687 DirectSound specific options are:
688
689 ``latency=usecs``
690 Add extra usecs microseconds latency to playback. Default is
691 10000 (10 ms).
692
693``-audiodev oss,id=id[,prop[=value][,...]]``
694 Creates a backend using OSS. This backend is available on most
695 Unix-like systems.
696
697 OSS specific options are:
698
699 ``in|out.dev=device``
700 Specify the file name of the OSS device to use. Default is
701 ``/dev/dsp``.
702
703 ``in|out.buffer-count=count``
704 Sets the count of the buffers.
705
706 ``in|out.try-poll=on|of``
707 Attempt to use poll mode with the device. Default is on.
708
709 ``try-mmap=on|off``
710 Try using memory mapped device access. Default is off.
711
712 ``exclusive=on|off``
713 Open the device in exclusive mode (vmix won't work in this
714 case). Default is off.
715
716 ``dsp-policy=policy``
717 Sets the timing policy (between 0 and 10, where smaller number
718 means smaller latency but higher CPU usage). Use -1 to use
719 buffer sizes specified by ``buffer`` and ``buffer-count``. This
720 option is ignored if you do not have OSS 4. Default is 5.
721
722``-audiodev pa,id=id[,prop[=value][,...]]``
723 Creates a backend using PulseAudio. This backend is available on
724 most systems.
725
726 PulseAudio specific options are:
727
728 ``server=server``
729 Sets the PulseAudio server to connect to.
730
731 ``in|out.name=sink``
732 Use the specified source/sink for recording/playback.
733
734 ``in|out.latency=usecs``
735 Desired latency in microseconds. The PulseAudio server will try
736 to honor this value but actual latencies may be lower or higher.
737
738``-audiodev sdl,id=id[,prop[=value][,...]]``
739 Creates a backend using SDL. This backend is available on most
740 systems, but you should use your platform's native backend if
741 possible. This backend has no backend specific properties.
742
743``-audiodev spice,id=id[,prop[=value][,...]]``
744 Creates a backend that sends audio through SPICE. This backend
745 requires ``-spice`` and automatically selected in that case, so
746 usually you can ignore this option. This backend has no backend
747 specific properties.
748
749``-audiodev wav,id=id[,prop[=value][,...]]``
750 Creates a backend that writes audio to a WAV file.
751
752 Backend specific options are:
753
754 ``path=path``
755 Write recorded audio into the specified file. Default is
756 ``qemu.wav``.
757ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100758
759DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
760 "-soundhw c1,... enable audio support\n"
761 " and only specified sound cards (comma separated list)\n"
762 " use '-soundhw help' to get the list of supported cards\n"
763 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000764SRST
765``-soundhw card1[,card2,...] or -soundhw all``
766 Enable audio and selected sound hardware. Use 'help' to print all
767 available sound hardware. For example:
768
769 .. parsed-literal::
770
771 |qemu_system_x86| -soundhw sb16,adlib disk.img
772 |qemu_system_x86| -soundhw es1370 disk.img
773 |qemu_system_x86| -soundhw ac97 disk.img
774 |qemu_system_x86| -soundhw hda disk.img
775 |qemu_system_x86| -soundhw all disk.img
776 |qemu_system_x86| -soundhw help
777
778 Note that Linux's i810\_audio OSS kernel (for AC97) module might
779 require manually specifying clocking.
780
781 ::
782
783 modprobe i810_audio clocking=48000
784ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100785
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100786DEF("device", HAS_ARG, QEMU_OPTION_device,
787 "-device driver[,prop[=value][,...]]\n"
788 " add device (based on driver)\n"
789 " prop=value,... sets driver properties\n"
790 " use '-device help' to print all possible drivers\n"
791 " use '-device driver,help' to print all possible properties\n",
792 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000793SRST
794``-device driver[,prop[=value][,...]]``
795 Add device driver. prop=value sets driver properties. Valid
796 properties depend on the driver. To get help on possible drivers and
797 properties, use ``-device help`` and ``-device driver,help``.
798
799 Some drivers are:
800
Corey Minyard789101b2020-07-17 11:37:02 -0500801``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000802 Add an IPMI BMC. This is a simulation of a hardware management
803 interface processor that normally sits on a system. It provides a
804 watchdog and the ability to reset and power control the system. You
805 need to connect this to an IPMI interface to make it useful
806
807 The IPMI slave address to use for the BMC. The default is 0x20. This
808 address is the BMC's address on the I2C network of management
809 controllers. If you don't know what this means, it is safe to ignore
810 it.
811
812 ``id=id``
813 The BMC id for interfaces to use this device.
814
815 ``slave_addr=val``
816 Define slave address to use for the BMC. The default is 0x20.
817
818 ``sdrfile=file``
819 file containing raw Sensor Data Records (SDR) data. The default
820 is none.
821
822 ``fruareasize=val``
823 size of a Field Replaceable Unit (FRU) area. The default is
824 1024.
825
826 ``frudatafile=file``
827 file containing raw Field Replaceable Unit (FRU) inventory data.
828 The default is none.
829
830 ``guid=uuid``
831 value for the GUID for the BMC, in standard UUID format. If this
832 is set, get "Get GUID" command to the BMC will return it.
833 Otherwise "Get GUID" will return an error.
834
835``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]``
836 Add a connection to an external IPMI BMC simulator. Instead of
837 locally emulating the BMC like the above item, instead connect to an
838 external entity that provides the IPMI services.
839
840 A connection is made to an external BMC simulator. If you do this,
841 it is strongly recommended that you use the "reconnect=" chardev
842 option to reconnect to the simulator if the connection is lost. Note
843 that if this is not used carefully, it can be a security issue, as
844 the interface has the ability to send resets, NMIs, and power off
845 the VM. It's best if QEMU makes a connection to an external
846 simulator running on a secure port on localhost, so neither the
847 simulator nor QEMU is exposed to any outside network.
848
849 See the "lanserv/README.vm" file in the OpenIPMI library for more
850 details on the external interface.
851
852``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]``
853 Add a KCS IPMI interafce on the ISA bus. This also adds a
854 corresponding ACPI and SMBIOS entries, if appropriate.
855
856 ``bmc=id``
857 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern
858 above.
859
860 ``ioport=val``
861 Define the I/O address of the interface. The default is 0xca0
862 for KCS.
863
864 ``irq=val``
865 Define the interrupt to use. The default is 5. To disable
866 interrupts, set this to 0.
867
868``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]``
869 Like the KCS interface, but defines a BT interface. The default port
870 is 0xe4 and the default interrupt is 5.
Corey Minyard323679d2019-09-23 13:50:33 -0500871
872``-device pci-ipmi-kcs,bmc=id``
873 Add a KCS IPMI interafce on the PCI bus.
874
875 ``bmc=id``
876 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
877
878``-device pci-ipmi-bt,bmc=id``
879 Like the KCS interface, but defines a BT interface on the PCI bus.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000880ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100881
882DEF("name", HAS_ARG, QEMU_OPTION_name,
Dr. David Alan Gilbert8f480de2014-01-30 10:20:31 +0000883 "-name string1[,process=string2][,debug-threads=on|off]\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100884 " set the name of the guest\n"
Roman Bolshakov479a5742018-12-17 23:26:01 +0300885 " string1 sets the window title and string2 the process name\n"
886 " When debug-threads is enabled, individual threads are given a separate name\n"
Dr. David Alan Gilbert8f480de2014-01-30 10:20:31 +0000887 " NOTE: The thread names are for debugging and not a stable API.\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100888 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000889SRST
890``-name name``
891 Sets the name of the guest. This name will be displayed in the SDL
892 window caption. The name will also be used for the VNC server. Also
893 optionally set the top visible process name in Linux. Naming of
894 individual threads can also be enabled on Linux to aid debugging.
895ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100896
897DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
898 "-uuid %08x-%04x-%04x-%04x-%012x\n"
899 " specify machine UUID\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000900SRST
901``-uuid uuid``
902 Set system UUID.
903ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100904
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100905DEFHEADING()
906
Markus Armbrusterde6b4f92017-10-02 16:03:00 +0200907DEFHEADING(Block device options:)
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100908
blueswir15824d652009-03-28 06:44:27 +0000909DEF("fda", HAS_ARG, QEMU_OPTION_fda,
Blue Swirlad960902010-03-29 19:23:52 +0000910 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
911DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000912SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000913``-fda file``
914 \
915``-fdb file``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000916 Use file as floppy disk 0/1 image (see
917 :ref:`disk_005fimages`).
918ERST
blueswir15824d652009-03-28 06:44:27 +0000919
920DEF("hda", HAS_ARG, QEMU_OPTION_hda,
Blue Swirlad960902010-03-29 19:23:52 +0000921 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
922DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +0000923DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
Blue Swirlad960902010-03-29 19:23:52 +0000924 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
925DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000926SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000927``-hda file``
928 \
929``-hdb file``
930 \
931``-hdc file``
932 \
933``-hdd file``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000934 Use file as hard disk 0, 1, 2 or 3 image (see
935 :ref:`disk_005fimages`).
936ERST
blueswir15824d652009-03-28 06:44:27 +0000937
938DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
Blue Swirlad960902010-03-29 19:23:52 +0000939 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
940 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000941SRST
942``-cdrom file``
943 Use file as CD-ROM image (you cannot use ``-hdc`` and ``-cdrom`` at
944 the same time). You can use the host CD-ROM by using ``/dev/cdrom``
945 as filename.
946ERST
blueswir15824d652009-03-28 06:44:27 +0000947
Markus Armbruster42e5f392017-02-28 22:27:07 +0100948DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
949 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
950 " [,cache.direct=on|off][,cache.no-flush=on|off]\n"
Kevin Wolfc9b749d2019-10-15 12:29:58 +0200951 " [,read-only=on|off][,auto-read-only=on|off]\n"
952 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n"
Markus Armbruster42e5f392017-02-28 22:27:07 +0100953 " [,driver specific parameters...]\n"
954 " configure a block backend\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000955SRST
956``-blockdev option[,option[,option[,...]]]``
957 Define a new block driver node. Some of the options apply to all
958 block drivers, other options are only accepted for a specific block
959 driver. See below for a list of generic options and options for the
960 most common block drivers.
961
962 Options that expect a reference to another node (e.g. ``file``) can
963 be given in two ways. Either you specify the node name of an already
964 existing node (file=node-name), or you define a new node inline,
965 adding options for the referenced node after a dot
966 (file.filename=path,file.aio=native).
967
968 A block driver node created with ``-blockdev`` can be used for a
969 guest device by specifying its node name for the ``drive`` property
970 in a ``-device`` argument that defines a block device.
971
972 ``Valid options for any block driver node:``
973 ``driver``
974 Specifies the block driver to use for the given node.
975
976 ``node-name``
977 This defines the name of the block driver node by which it
978 will be referenced later. The name must be unique, i.e. it
979 must not match the name of a different block driver node, or
980 (if you use ``-drive`` as well) the ID of a drive.
981
982 If no node name is specified, it is automatically generated.
983 The generated node name is not intended to be predictable
984 and changes between QEMU invocations. For the top level, an
985 explicit node name must be specified.
986
987 ``read-only``
988 Open the node read-only. Guest write attempts will fail.
989
990 Note that some block drivers support only read-only access,
991 either generally or in certain configurations. In this case,
992 the default value ``read-only=off`` does not work and the
993 option must be specified explicitly.
994
995 ``auto-read-only``
996 If ``auto-read-only=on`` is set, QEMU may fall back to
997 read-only usage even when ``read-only=off`` is requested, or
998 even switch between modes as needed, e.g. depending on
999 whether the image file is writable or whether a writing user
1000 is attached to the node.
1001
1002 ``force-share``
1003 Override the image locking system of QEMU by forcing the
1004 node to utilize weaker shared access for permissions where
1005 it would normally request exclusive access. When there is
1006 the potential for multiple instances to have the same file
1007 open (whether this invocation of QEMU is the first or the
1008 second instance), both instances must permit shared access
1009 for the second instance to succeed at opening the file.
1010
1011 Enabling ``force-share=on`` requires ``read-only=on``.
1012
1013 ``cache.direct``
1014 The host page cache can be avoided with ``cache.direct=on``.
1015 This will attempt to do disk IO directly to the guest's
1016 memory. QEMU may still perform an internal copy of the data.
1017
1018 ``cache.no-flush``
1019 In case you don't care about data integrity over host
1020 failures, you can use ``cache.no-flush=on``. This option
1021 tells QEMU that it never needs to write any data to the disk
1022 but can instead keep things in cache. If anything goes
1023 wrong, like your host losing power, the disk storage getting
1024 disconnected accidentally, etc. your image will most
1025 probably be rendered unusable.
1026
1027 ``discard=discard``
1028 discard is one of "ignore" (or "off") or "unmap" (or "on")
1029 and controls whether ``discard`` (also known as ``trim`` or
1030 ``unmap``) requests are ignored or passed to the filesystem.
1031 Some machine types may not support discard requests.
1032
1033 ``detect-zeroes=detect-zeroes``
1034 detect-zeroes is "off", "on" or "unmap" and enables the
1035 automatic conversion of plain zero writes by the OS to
1036 driver specific optimized zero write commands. You may even
1037 choose "unmap" if discard is set to "unmap" to allow a zero
1038 write to be converted to an ``unmap`` operation.
1039
1040 ``Driver-specific options for file``
1041 This is the protocol-level block driver for accessing regular
1042 files.
1043
1044 ``filename``
1045 The path to the image file in the local filesystem
1046
1047 ``aio``
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001048 Specifies the AIO backend (threads/native/io_uring,
1049 default: threads)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001050
1051 ``locking``
1052 Specifies whether the image file is protected with Linux OFD
1053 / POSIX locks. The default is to use the Linux Open File
1054 Descriptor API if available, otherwise no lock is applied.
1055 (auto/on/off, default: auto)
1056
1057 Example:
1058
1059 ::
1060
1061 -blockdev driver=file,node-name=disk,filename=disk.img
1062
1063 ``Driver-specific options for raw``
1064 This is the image format block driver for raw images. It is
1065 usually stacked on top of a protocol level block driver such as
1066 ``file``.
1067
1068 ``file``
1069 Reference to or definition of the data source block driver
1070 node (e.g. a ``file`` driver node)
1071
1072 Example 1:
1073
1074 ::
1075
1076 -blockdev driver=file,node-name=disk_file,filename=disk.img
1077 -blockdev driver=raw,node-name=disk,file=disk_file
1078
1079 Example 2:
1080
1081 ::
1082
1083 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
1084
1085 ``Driver-specific options for qcow2``
1086 This is the image format block driver for qcow2 images. It is
1087 usually stacked on top of a protocol level block driver such as
1088 ``file``.
1089
1090 ``file``
1091 Reference to or definition of the data source block driver
1092 node (e.g. a ``file`` driver node)
1093
1094 ``backing``
1095 Reference to or definition of the backing file block device
1096 (default is taken from the image file). It is allowed to
1097 pass ``null`` here in order to disable the default backing
1098 file.
1099
1100 ``lazy-refcounts``
1101 Whether to enable the lazy refcounts feature (on/off;
1102 default is taken from the image file)
1103
1104 ``cache-size``
1105 The maximum total size of the L2 table and refcount block
1106 caches in bytes (default: the sum of l2-cache-size and
1107 refcount-cache-size)
1108
1109 ``l2-cache-size``
1110 The maximum size of the L2 table cache in bytes (default: if
1111 cache-size is not specified - 32M on Linux platforms, and 8M
1112 on non-Linux platforms; otherwise, as large as possible
1113 within the cache-size, while permitting the requested or the
1114 minimal refcount cache size)
1115
1116 ``refcount-cache-size``
1117 The maximum size of the refcount block cache in bytes
1118 (default: 4 times the cluster size; or if cache-size is
1119 specified, the part of it which is not used for the L2
1120 cache)
1121
1122 ``cache-clean-interval``
1123 Clean unused entries in the L2 and refcount caches. The
1124 interval is in seconds. The default value is 600 on
1125 supporting platforms, and 0 on other platforms. Setting it
1126 to 0 disables this feature.
1127
1128 ``pass-discard-request``
1129 Whether discard requests to the qcow2 device should be
1130 forwarded to the data source (on/off; default: on if
1131 discard=unmap is specified, off otherwise)
1132
1133 ``pass-discard-snapshot``
1134 Whether discard requests for the data source should be
1135 issued when a snapshot operation (e.g. deleting a snapshot)
1136 frees clusters in the qcow2 file (on/off; default: on)
1137
1138 ``pass-discard-other``
1139 Whether discard requests for the data source should be
1140 issued on other occasions where a cluster gets freed
1141 (on/off; default: off)
1142
1143 ``overlap-check``
1144 Which overlap checks to perform for writes to the image
1145 (none/constant/cached/all; default: cached). For details or
1146 finer granularity control refer to the QAPI documentation of
1147 ``blockdev-add``.
1148
1149 Example 1:
1150
1151 ::
1152
1153 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
1154 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
1155
1156 Example 2:
1157
1158 ::
1159
1160 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
1161
1162 ``Driver-specific options for other drivers``
1163 Please refer to the QAPI documentation of the ``blockdev-add``
1164 QMP command.
1165ERST
Markus Armbruster42e5f392017-02-28 22:27:07 +01001166
blueswir15824d652009-03-28 06:44:27 +00001167DEF("drive", HAS_ARG, QEMU_OPTION_drive,
1168 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
Stefan Hajnoczi92196b22011-08-04 12:26:52 +01001169 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
Kevin Wolf572023f2018-06-13 11:01:30 +02001170 " [,snapshot=on|off][,rerror=ignore|stop|report]\n"
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001171 " [,werror=ignore|stop|report|enospc][,id=name]\n"
1172 " [,aio=threads|native|io_uring]\n"
Stefan Hajnoczifb0490f2011-11-17 13:40:32 +00001173 " [,readonly=on|off][,copy-on-read=on|off]\n"
Peter Lieven2f7133b2014-07-28 21:53:02 +02001174 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
Benoît Canet3e9fab62013-09-02 14:14:40 +02001175 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
1176 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
1177 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
1178 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
Benoît Canet2024c1d2013-09-02 14:14:41 +02001179 " [[,iops_size=is]]\n"
Alberto Garcia76f4afb2015-06-08 18:17:44 +02001180 " [[,group=g]]\n"
Blue Swirlad960902010-03-29 19:23:52 +00001181 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001182SRST
1183``-drive option[,option[,option[,...]]]``
1184 Define a new drive. This includes creating a block driver node (the
1185 backend) as well as a guest device, and is mostly a shortcut for
1186 defining the corresponding ``-blockdev`` and ``-device`` options.
1187
1188 ``-drive`` accepts all options that are accepted by ``-blockdev``.
1189 In addition, it knows the following options:
1190
1191 ``file=file``
1192 This option defines which disk image (see
1193 :ref:`disk_005fimages`) to use with this drive. If
1194 the filename contains comma, you must double it (for instance,
1195 "file=my,,file" to use file "my,file").
1196
1197 Special files such as iSCSI devices can be specified using
1198 protocol specific URLs. See the section for "Device URL Syntax"
1199 for more information.
1200
1201 ``if=interface``
1202 This option defines on which type on interface the drive is
1203 connected. Available types are: ide, scsi, sd, mtd, floppy,
1204 pflash, virtio, none.
1205
1206 ``bus=bus,unit=unit``
1207 These options define where is connected the drive by defining
1208 the bus number and the unit id.
1209
1210 ``index=index``
1211 This option defines where is connected the drive by using an
1212 index in the list of available connectors of a given interface
1213 type.
1214
1215 ``media=media``
1216 This option defines the type of the media: disk or cdrom.
1217
1218 ``snapshot=snapshot``
1219 snapshot is "on" or "off" and controls snapshot mode for the
1220 given drive (see ``-snapshot``).
1221
1222 ``cache=cache``
1223 cache is "none", "writeback", "unsafe", "directsync" or
1224 "writethrough" and controls how the host cache is used to access
1225 block data. This is a shortcut that sets the ``cache.direct``
1226 and ``cache.no-flush`` options (as in ``-blockdev``), and
1227 additionally ``cache.writeback``, which provides a default for
1228 the ``write-cache`` option of block guest devices (as in
1229 ``-device``). The modes correspond to the following settings:
1230
Peter Maydell09ce5f22020-02-28 15:36:13 +00001231 ============= =============== ============ ==============
1232 \ cache.writeback cache.direct cache.no-flush
1233 ============= =============== ============ ==============
1234 writeback on off off
1235 none on on off
1236 writethrough off off off
1237 directsync off on off
1238 unsafe on off on
1239 ============= =============== ============ ==============
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001240
1241 The default mode is ``cache=writeback``.
1242
1243 ``aio=aio``
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001244 aio is "threads", "native", or "io_uring" and selects between pthread
1245 based disk I/O, native Linux AIO, or Linux io_uring API.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001246
1247 ``format=format``
1248 Specify which disk format will be used rather than detecting the
1249 format. Can be used to specify format=raw to avoid interpreting
1250 an untrusted format header.
1251
1252 ``werror=action,rerror=action``
1253 Specify which action to take on write and read errors. Valid
1254 actions are: "ignore" (ignore the error and try to continue),
1255 "stop" (pause QEMU), "report" (report the error to the guest),
1256 "enospc" (pause QEMU only if the host disk is full; report the
1257 error to the guest otherwise). The default setting is
1258 ``werror=enospc`` and ``rerror=report``.
1259
1260 ``copy-on-read=copy-on-read``
1261 copy-on-read is "on" or "off" and enables whether to copy read
1262 backing file sectors into the image file.
1263
1264 ``bps=b,bps_rd=r,bps_wr=w``
1265 Specify bandwidth throttling limits in bytes per second, either
1266 for all request types or for reads or writes only. Small values
1267 can lead to timeouts or hangs inside the guest. A safe minimum
1268 for disks is 2 MB/s.
1269
1270 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm``
1271 Specify bursts in bytes per second, either for all request types
1272 or for reads or writes only. Bursts allow the guest I/O to spike
1273 above the limit temporarily.
1274
1275 ``iops=i,iops_rd=r,iops_wr=w``
1276 Specify request rate limits in requests per second, either for
1277 all request types or for reads or writes only.
1278
1279 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm``
1280 Specify bursts in requests per second, either for all request
1281 types or for reads or writes only. Bursts allow the guest I/O to
1282 spike above the limit temporarily.
1283
1284 ``iops_size=is``
1285 Let every is bytes of a request count as a new request for iops
1286 throttling purposes. Use this option to prevent guests from
1287 circumventing iops limits by sending fewer but larger requests.
1288
1289 ``group=g``
1290 Join a throttling quota group with given name g. All drives that
1291 are members of the same group are accounted for together. Use
1292 this option to prevent guests from circumventing throttling
1293 limits by using many small disks instead of a single larger
1294 disk.
1295
1296 By default, the ``cache.writeback=on`` mode is used. It will report
1297 data writes as completed as soon as the data is present in the host
1298 page cache. This is safe as long as your guest OS makes sure to
1299 correctly flush disk caches where needed. If your guest OS does not
1300 handle volatile disk write caches correctly and your host crashes or
1301 loses power, then the guest may experience data corruption.
1302
1303 For such guests, you should consider using ``cache.writeback=off``.
1304 This means that the host page cache will be used to read and write
1305 data, but write notification will be sent to the guest only after
1306 QEMU has made sure to flush each write to the disk. Be aware that
1307 this has a major impact on performance.
1308
1309 When using the ``-snapshot`` option, unsafe caching is always used.
1310
1311 Copy-on-read avoids accessing the same backing file sectors
1312 repeatedly and is useful when the backing file is over a slow
1313 network. By default copy-on-read is off.
1314
1315 Instead of ``-cdrom`` you can use:
1316
1317 .. parsed-literal::
1318
1319 |qemu_system| -drive file=file,index=2,media=cdrom
1320
1321 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use:
1322
1323 .. parsed-literal::
1324
1325 |qemu_system| -drive file=file,index=0,media=disk
1326 |qemu_system| -drive file=file,index=1,media=disk
1327 |qemu_system| -drive file=file,index=2,media=disk
1328 |qemu_system| -drive file=file,index=3,media=disk
1329
1330 You can open an image using pre-opened file descriptors from an fd
1331 set:
1332
1333 .. parsed-literal::
1334
Laszlo Ersek353a06b2020-09-08 19:21:11 +02001335 |qemu_system| \\
1336 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\
1337 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001338 -drive file=/dev/fdset/2,index=0,media=disk
1339
1340 You can connect a CDROM to the slave of ide0:
1341
1342 .. parsed-literal::
1343
1344 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom
1345
1346 If you don't specify the "file=" argument, you define an empty
1347 drive:
1348
1349 .. parsed-literal::
1350
1351 |qemu_system_x86| -drive if=ide,index=1,media=cdrom
1352
1353 Instead of ``-fda``, ``-fdb``, you can use:
1354
1355 .. parsed-literal::
1356
1357 |qemu_system_x86| -drive file=file,index=0,if=floppy
1358 |qemu_system_x86| -drive file=file,index=1,if=floppy
1359
1360 By default, interface is "ide" and index is automatically
1361 incremented:
1362
1363 .. parsed-literal::
1364
1365 |qemu_system_x86| -drive file=a -drive file=b"
1366
1367 is interpreted like:
1368
1369 .. parsed-literal::
1370
1371 |qemu_system_x86| -hda a -hdb b
1372ERST
blueswir15824d652009-03-28 06:44:27 +00001373
1374DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
Blue Swirlad960902010-03-29 19:23:52 +00001375 "-mtdblock file use 'file' as on-board Flash memory image\n",
1376 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001377SRST
1378``-mtdblock file``
1379 Use file as on-board Flash memory image.
1380ERST
blueswir15824d652009-03-28 06:44:27 +00001381
1382DEF("sd", HAS_ARG, QEMU_OPTION_sd,
Blue Swirlad960902010-03-29 19:23:52 +00001383 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001384SRST
1385``-sd file``
1386 Use file as SecureDigital card image.
1387ERST
blueswir15824d652009-03-28 06:44:27 +00001388
1389DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
Blue Swirlad960902010-03-29 19:23:52 +00001390 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001391SRST
1392``-pflash file``
1393 Use file as a parallel flash image.
1394ERST
blueswir15824d652009-03-28 06:44:27 +00001395
blueswir15824d652009-03-28 06:44:27 +00001396DEF("snapshot", 0, QEMU_OPTION_snapshot,
Blue Swirlad960902010-03-29 19:23:52 +00001397 "-snapshot write to temporary files instead of disk image files\n",
1398 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001399SRST
1400``-snapshot``
1401 Write to temporary files instead of disk image files. In this case,
1402 the raw disk image you use is not written back. You can however
1403 force the write back by pressing C-a s (see
1404 :ref:`disk_005fimages`).
1405ERST
blueswir15824d652009-03-28 06:44:27 +00001406
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301407DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
Greg Kurzb44a6b02019-05-17 17:34:49 +02001408 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n"
1409 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n"
Pradeep Jagadeeshb8bbdb82017-02-28 10:31:46 +01001410 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1411 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1412 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1413 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
Greg Kurzb44a6b02019-05-17 17:34:49 +02001414 " [[,throttling.iops-size=is]]\n"
1415 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n"
1416 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n"
1417 "-fsdev synth,id=id\n",
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301418 QEMU_ARCH_ALL)
1419
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001420SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00001421``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]``
1422 \
1423``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly]``
1424 \
1425``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly]``
1426 \
1427``-fsdev synth,id=id[,readonly]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001428 Define a new file system device. Valid options are:
1429
1430 ``local``
1431 Accesses to the filesystem are done by QEMU.
1432
1433 ``proxy``
1434 Accesses to the filesystem are done by virtfs-proxy-helper(1).
1435
1436 ``synth``
1437 Synthetic filesystem, only used by QTests.
1438
1439 ``id=id``
1440 Specifies identifier for this device.
1441
1442 ``path=path``
1443 Specifies the export path for the file system device. Files
1444 under this path will be available to the 9p client on the guest.
1445
1446 ``security_model=security_model``
1447 Specifies the security model to be used for this export path.
1448 Supported security models are "passthrough", "mapped-xattr",
1449 "mapped-file" and "none". In "passthrough" security model, files
1450 are stored using the same credentials as they are created on the
1451 guest. This requires QEMU to run as root. In "mapped-xattr"
1452 security model, some of the file attributes like uid, gid, mode
1453 bits and link target are stored as file attributes. For
1454 "mapped-file" these attributes are stored in the hidden
1455 .virtfs\_metadata directory. Directories exported by this
1456 security model cannot interact with other unix tools. "none"
1457 security model is same as passthrough except the sever won't
1458 report failures if it fails to set file attributes like
1459 ownership. Security model is mandatory only for local fsdriver.
1460 Other fsdrivers (like proxy) don't take security model as a
1461 parameter.
1462
1463 ``writeout=writeout``
1464 This is an optional argument. The only supported value is
1465 "immediate". This means that host page cache will be used to
1466 read and write data but write notification will be sent to the
1467 guest only when the data has been reported as written by the
1468 storage subsystem.
1469
1470 ``readonly``
1471 Enables exporting 9p share as a readonly mount for guests. By
1472 default read-write access is given.
1473
1474 ``socket=socket``
1475 Enables proxy filesystem driver to use passed socket file for
1476 communicating with virtfs-proxy-helper(1).
1477
1478 ``sock_fd=sock_fd``
1479 Enables proxy filesystem driver to use passed socket descriptor
1480 for communicating with virtfs-proxy-helper(1). Usually a helper
1481 like libvirt will create socketpair and pass one of the fds as
1482 sock\_fd.
1483
1484 ``fmode=fmode``
1485 Specifies the default mode for newly created files on the host.
1486 Works only with security models "mapped-xattr" and
1487 "mapped-file".
1488
1489 ``dmode=dmode``
1490 Specifies the default mode for newly created directories on the
1491 host. Works only with security models "mapped-xattr" and
1492 "mapped-file".
1493
1494 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w``
1495 Specify bandwidth throttling limits in bytes per second, either
1496 for all request types or for reads or writes only.
1497
1498 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm``
1499 Specify bursts in bytes per second, either for all request types
1500 or for reads or writes only. Bursts allow the guest I/O to spike
1501 above the limit temporarily.
1502
1503 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w``
1504 Specify request rate limits in requests per second, either for
1505 all request types or for reads or writes only.
1506
1507 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm``
1508 Specify bursts in requests per second, either for all request
1509 types or for reads or writes only. Bursts allow the guest I/O to
1510 spike above the limit temporarily.
1511
1512 ``throttling.iops-size=is``
1513 Let every is bytes of a request count as a new request for iops
1514 throttling purposes.
1515
1516 -fsdev option is used along with -device driver "virtio-9p-...".
1517
1518``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag``
1519 Options for virtio-9p-... driver are:
1520
1521 ``type``
1522 Specifies the variant to be used. Supported values are "pci",
1523 "ccw" or "device", depending on the machine type.
1524
1525 ``fsdev=id``
1526 Specifies the id value specified along with -fsdev option.
1527
1528 ``mount_tag=mount_tag``
1529 Specifies the tag name to be used by the guest to mount this
1530 export point.
1531ERST
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301532
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301533DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
Greg Kurzb44a6b02019-05-17 17:34:49 +02001534 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n"
Antonios Motakis1a6ed332019-10-10 11:36:05 +02001535 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n"
Greg Kurzb44a6b02019-05-17 17:34:49 +02001536 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n"
1537 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n"
1538 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n",
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301539 QEMU_ARCH_ALL)
1540
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001541SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00001542``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]``
1543 \
1544``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly]``
1545 \
1546``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly]``
1547 \
1548``-virtfs synth,mount_tag=mount_tag``
Christian Schoenebeck65abaa02020-05-14 08:06:43 +02001549 Define a new virtual filesystem device and expose it to the guest using
1550 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain
1551 directory on host is made directly accessible by guest as a pass-through
1552 file system by using the 9P network protocol for communication between
1553 host and guests, if desired even accessible, shared by several guests
1554 simultaniously.
1555
1556 Note that ``-virtfs`` is actually just a convenience shortcut for its
1557 generalized form ``-fsdev -device virtio-9p-pci``.
1558
1559 The general form of pass-through file system options are:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001560
1561 ``local``
1562 Accesses to the filesystem are done by QEMU.
1563
1564 ``proxy``
1565 Accesses to the filesystem are done by virtfs-proxy-helper(1).
1566
1567 ``synth``
1568 Synthetic filesystem, only used by QTests.
1569
1570 ``id=id``
1571 Specifies identifier for the filesystem device
1572
1573 ``path=path``
1574 Specifies the export path for the file system device. Files
1575 under this path will be available to the 9p client on the guest.
1576
1577 ``security_model=security_model``
1578 Specifies the security model to be used for this export path.
1579 Supported security models are "passthrough", "mapped-xattr",
1580 "mapped-file" and "none". In "passthrough" security model, files
1581 are stored using the same credentials as they are created on the
1582 guest. This requires QEMU to run as root. In "mapped-xattr"
1583 security model, some of the file attributes like uid, gid, mode
1584 bits and link target are stored as file attributes. For
1585 "mapped-file" these attributes are stored in the hidden
1586 .virtfs\_metadata directory. Directories exported by this
1587 security model cannot interact with other unix tools. "none"
1588 security model is same as passthrough except the sever won't
1589 report failures if it fails to set file attributes like
1590 ownership. Security model is mandatory only for local fsdriver.
1591 Other fsdrivers (like proxy) don't take security model as a
1592 parameter.
1593
1594 ``writeout=writeout``
1595 This is an optional argument. The only supported value is
1596 "immediate". This means that host page cache will be used to
1597 read and write data but write notification will be sent to the
1598 guest only when the data has been reported as written by the
1599 storage subsystem.
1600
1601 ``readonly``
1602 Enables exporting 9p share as a readonly mount for guests. By
1603 default read-write access is given.
1604
1605 ``socket=socket``
1606 Enables proxy filesystem driver to use passed socket file for
1607 communicating with virtfs-proxy-helper(1). Usually a helper like
1608 libvirt will create socketpair and pass one of the fds as
1609 sock\_fd.
1610
1611 ``sock_fd``
1612 Enables proxy filesystem driver to use passed 'sock\_fd' as the
1613 socket descriptor for interfacing with virtfs-proxy-helper(1).
1614
1615 ``fmode=fmode``
1616 Specifies the default mode for newly created files on the host.
1617 Works only with security models "mapped-xattr" and
1618 "mapped-file".
1619
1620 ``dmode=dmode``
1621 Specifies the default mode for newly created directories on the
1622 host. Works only with security models "mapped-xattr" and
1623 "mapped-file".
1624
1625 ``mount_tag=mount_tag``
1626 Specifies the tag name to be used by the guest to mount this
1627 export point.
1628
1629 ``multidevs=multidevs``
1630 Specifies how to deal with multiple devices being shared with a
1631 9p export. Supported behaviours are either "remap", "forbid" or
1632 "warn". The latter is the default behaviour on which virtfs 9p
1633 expects only one device to be shared with the same export, and
1634 if more than one device is shared and accessed via the same 9p
1635 export then only a warning message is logged (once) by qemu on
1636 host side. In order to avoid file ID collisions on guest you
1637 should either create a separate virtfs export for each device to
1638 be shared with guests (recommended way) or you might use "remap"
1639 instead which allows you to share multiple devices with only one
1640 export instead, which is achieved by remapping the original
1641 inode numbers from host to guest in a way that would prevent
1642 such collisions. Remapping inodes in such use cases is required
1643 because the original device IDs from host are never passed and
1644 exposed on guest. Instead all files of an export shared with
1645 virtfs always share the same device id on guest. So two files
1646 with identical inode numbers but from actually different devices
1647 on host would otherwise cause a file ID collision and hence
1648 potential misbehaviours on guest. "forbid" on the other hand
1649 assumes like "warn" that only one device is shared by the same
1650 export, however it will not only log a warning message but also
1651 deny access to additional devices on guest. Note though that
1652 "forbid" does currently not block all possible file access
1653 operations (e.g. readdir() would still return entries from other
1654 devices).
1655ERST
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301656
Markus Armbruster61d70482017-10-02 16:03:03 +02001657DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1658 "-iscsi [user=user][,password=password]\n"
1659 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1660 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1661 " [,timeout=timeout]\n"
1662 " iSCSI session parameters\n", QEMU_ARCH_ALL)
1663
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001664SRST
1665``-iscsi``
1666 Configure iSCSI session parameters.
1667ERST
Markus Armbruster44743142017-10-02 16:03:04 +02001668
blueswir15824d652009-03-28 06:44:27 +00001669DEFHEADING()
1670
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02001671DEFHEADING(USB options:)
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001672
1673DEF("usb", 0, QEMU_OPTION_usb,
Stefan Hajnoczi73f46fe2019-08-15 15:14:28 +01001674 "-usb enable on-board USB host controller (if not enabled by default)\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001675 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001676SRST
1677``-usb``
1678 Enable USB emulation on machine types with an on-board USB host
1679 controller (if not enabled by default). Note that on-board USB host
1680 controllers may not support USB 3.0. In this case
1681 ``-device qemu-xhci`` can be used instead on machines with PCI.
1682ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001683
1684DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1685 "-usbdevice name add the host or guest USB device 'name'\n",
1686 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001687SRST
1688``-usbdevice devname``
1689 Add the USB device devname. Note that this option is deprecated,
1690 please use ``-device usb-...`` instead. See
1691 :ref:`usb_005fdevices`.
1692
1693 ``mouse``
1694 Virtual Mouse. This will override the PS/2 mouse emulation when
1695 activated.
1696
1697 ``tablet``
1698 Pointer device that uses absolute coordinates (like a
1699 touchscreen). This means QEMU is able to report the mouse
1700 position without having to grab the mouse. Also overrides the
1701 PS/2 mouse emulation when activated.
1702
1703 ``braille``
1704 Braille device. This will use BrlAPI to display the braille
1705 output on a real or fake device.
1706ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001707
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001708DEFHEADING()
1709
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02001710DEFHEADING(Display options:)
blueswir15824d652009-03-28 06:44:27 +00001711
Jes Sorensen1472a952011-03-16 13:33:31 +01001712DEF("display", HAS_ARG, QEMU_OPTION_display,
Thomas Huth88b40c62019-10-23 14:01:28 +02001713#if defined(CONFIG_SPICE)
Marc-André Lureaud8aec9d2019-02-21 12:07:03 +01001714 "-display spice-app[,gl=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02001715#endif
1716#if defined(CONFIG_SDL)
1717 "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off]\n"
Elie Tournier4867e472018-04-13 14:58:42 +01001718 " [,window_close=on|off][,gl=on|core|es|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02001719#endif
Robert Hof04ec5a2016-07-26 18:17:11 +08001720#if defined(CONFIG_GTK)
Thomas Huth88b40c62019-10-23 14:01:28 +02001721 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1722#endif
1723#if defined(CONFIG_VNC)
1724 "-display vnc=<display>[,<optargs>]\n"
1725#endif
1726#if defined(CONFIG_CURSES)
1727 "-display curses[,charset=<encoding>]\n"
1728#endif
1729#if defined(CONFIG_OPENGL)
1730 "-display egl-headless[,rendernode=<file>]\n"
1731#endif
1732 "-display none\n"
1733 " select display backend type\n"
1734 " The default display is equivalent to\n "
1735#if defined(CONFIG_GTK)
1736 "\"-display gtk\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08001737#elif defined(CONFIG_SDL)
Thomas Huth88b40c62019-10-23 14:01:28 +02001738 "\"-display sdl\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08001739#elif defined(CONFIG_COCOA)
Thomas Huth88b40c62019-10-23 14:01:28 +02001740 "\"-display cocoa\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08001741#elif defined(CONFIG_VNC)
Thomas Huth88b40c62019-10-23 14:01:28 +02001742 "\"-vnc localhost:0,to=99,id=default\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08001743#else
Thomas Huth88b40c62019-10-23 14:01:28 +02001744 "\"-display none\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08001745#endif
1746 , QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001747SRST
1748``-display type``
1749 Select type of display to use. This option is a replacement for the
1750 old style -sdl/-curses/... options. Use ``-display help`` to list
1751 the available display types. Valid values for type are
1752
1753 ``sdl``
1754 Display video output via SDL (usually in a separate graphics
1755 window; see the SDL documentation for other possibilities).
1756
1757 ``curses``
1758 Display video output via curses. For graphics device models
1759 which support a text mode, QEMU can display this output using a
1760 curses/ncurses interface. Nothing is displayed when the graphics
1761 device is in graphical mode or if the graphics device does not
1762 support a text mode. Generally only the VGA device models
1763 support text mode. The font charset used by the guest can be
1764 specified with the ``charset`` option, for example
1765 ``charset=CP850`` for IBM CP850 encoding. The default is
1766 ``CP437``.
1767
1768 ``none``
1769 Do not display video output. The guest will still see an
1770 emulated graphics card, but its output will not be displayed to
1771 the QEMU user. This option differs from the -nographic option in
1772 that it only affects what is done with video output; -nographic
1773 also changes the destination of the serial and parallel port
1774 data.
1775
1776 ``gtk``
1777 Display video output in a GTK window. This interface provides
1778 drop-down menus and other UI elements to configure and control
1779 the VM during runtime.
1780
1781 ``vnc``
1782 Start a VNC server on display <arg>
1783
1784 ``egl-headless``
1785 Offload all OpenGL operations to a local DRI device. For any
1786 graphical display, this display needs to be paired with either
1787 VNC or SPICE displays.
1788
1789 ``spice-app``
1790 Start QEMU as a Spice server and launch the default Spice client
1791 application. The Spice server will redirect the serial consoles
1792 and QEMU monitors. (Since 4.0)
1793ERST
Jes Sorensen1472a952011-03-16 13:33:31 +01001794
blueswir15824d652009-03-28 06:44:27 +00001795DEF("nographic", 0, QEMU_OPTION_nographic,
Blue Swirlad960902010-03-29 19:23:52 +00001796 "-nographic disable graphical output and redirect serial I/Os to console\n",
1797 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001798SRST
1799``-nographic``
1800 Normally, if QEMU is compiled with graphical window support, it
1801 displays output such as guest graphics, guest console, and the QEMU
1802 monitor in a window. With this option, you can totally disable
1803 graphical output so that QEMU is a simple command line application.
1804 The emulated serial port is redirected on the console and muxed with
1805 the monitor (unless redirected elsewhere explicitly). Therefore, you
1806 can still use QEMU to debug a Linux kernel with a serial console.
1807 Use C-a h for help on switching between the console and monitor.
1808ERST
blueswir15824d652009-03-28 06:44:27 +00001809
blueswir15824d652009-03-28 06:44:27 +00001810DEF("curses", 0, QEMU_OPTION_curses,
Robert Hof04ec5a2016-07-26 18:17:11 +08001811 "-curses shorthand for -display curses\n",
Blue Swirlad960902010-03-29 19:23:52 +00001812 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001813SRST
1814``-curses``
1815 Normally, if QEMU is compiled with graphical window support, it
1816 displays output such as guest graphics, guest console, and the QEMU
1817 monitor in a window. With this option, QEMU can display the VGA
1818 output when in text mode using a curses/ncurses interface. Nothing
1819 is displayed in graphical mode.
1820ERST
blueswir15824d652009-03-28 06:44:27 +00001821
blueswir15824d652009-03-28 06:44:27 +00001822DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
Blue Swirlad960902010-03-29 19:23:52 +00001823 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1824 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001825SRST
1826``-alt-grab``
1827 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that
1828 this also affects the special keys (for fullscreen, monitor-mode
1829 switching, etc).
1830ERST
blueswir15824d652009-03-28 06:44:27 +00001831
Dustin Kirkland0ca9f8a2009-09-17 15:48:04 -05001832DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
Blue Swirlad960902010-03-29 19:23:52 +00001833 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1834 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001835SRST
1836``-ctrl-grab``
1837 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this
1838 also affects the special keys (for fullscreen, monitor-mode
1839 switching, etc).
1840ERST
Dustin Kirkland0ca9f8a2009-09-17 15:48:04 -05001841
blueswir15824d652009-03-28 06:44:27 +00001842DEF("no-quit", 0, QEMU_OPTION_no_quit,
Blue Swirlad960902010-03-29 19:23:52 +00001843 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001844SRST
1845``-no-quit``
1846 Disable SDL window close capability.
1847ERST
blueswir15824d652009-03-28 06:44:27 +00001848
blueswir15824d652009-03-28 06:44:27 +00001849DEF("sdl", 0, QEMU_OPTION_sdl,
Robert Hof04ec5a2016-07-26 18:17:11 +08001850 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001851SRST
1852``-sdl``
1853 Enable SDL.
1854ERST
blueswir15824d652009-03-28 06:44:27 +00001855
Gerd Hoffmann29b00402010-03-11 11:13:27 -03001856DEF("spice", HAS_ARG, QEMU_OPTION_spice,
Yonit Halperin27af7782012-08-21 13:54:20 +03001857 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1858 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1859 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
Marc-André Lureaufe4831b2015-01-13 17:57:51 +01001860 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
Yonit Halperin27af7782012-08-21 13:54:20 +03001861 " [,tls-ciphers=<list>]\n"
1862 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1863 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1864 " [,sasl][,password=<secret>][,disable-ticketing]\n"
1865 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1866 " [,jpeg-wan-compression=[auto|never|always]]\n"
1867 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
1868 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
Hans de Goede5ad24e52013-06-08 15:37:27 +02001869 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1870 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
Marc-André Lureau7b525502017-02-12 15:21:18 +04001871 " [,gl=[on|off]][,rendernode=<file>]\n"
Yonit Halperin27af7782012-08-21 13:54:20 +03001872 " enable spice\n"
1873 " at least one of {port, tls-port} is mandatory\n",
1874 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001875SRST
1876``-spice option[,option[,...]]``
1877 Enable the spice remote desktop protocol. Valid options are
1878
1879 ``port=<nr>``
1880 Set the TCP port spice is listening on for plaintext channels.
1881
1882 ``addr=<addr>``
1883 Set the IP address spice is listening on. Default is any
1884 address.
1885
1886 ``ipv4``; \ ``ipv6``; \ ``unix``
1887 Force using the specified IP version.
1888
1889 ``password=<secret>``
1890 Set the password you need to authenticate.
1891
1892 ``sasl``
1893 Require that the client use SASL to authenticate with the spice.
1894 The exact choice of authentication method used is controlled
1895 from the system / user's SASL configuration file for the 'qemu'
1896 service. This is typically found in /etc/sasl2/qemu.conf. If
1897 running QEMU as an unprivileged user, an environment variable
1898 SASL\_CONF\_PATH can be used to make it search alternate
1899 locations for the service config. While some SASL auth methods
1900 can also provide data encryption (eg GSSAPI), it is recommended
1901 that SASL always be combined with the 'tls' and 'x509' settings
1902 to enable use of SSL and server certificates. This ensures a
1903 data encryption preventing compromise of authentication
1904 credentials.
1905
1906 ``disable-ticketing``
1907 Allow client connects without authentication.
1908
1909 ``disable-copy-paste``
1910 Disable copy paste between the client and the guest.
1911
1912 ``disable-agent-file-xfer``
1913 Disable spice-vdagent based file-xfer between the client and the
1914 guest.
1915
1916 ``tls-port=<nr>``
1917 Set the TCP port spice is listening on for encrypted channels.
1918
1919 ``x509-dir=<dir>``
1920 Set the x509 file directory. Expects same filenames as -vnc
1921 $display,x509=$dir
1922
1923 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>``
1924 The x509 file names can also be configured individually.
1925
1926 ``tls-ciphers=<list>``
1927 Specify which ciphers to use.
1928
1929 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]``
1930 Force specific channel to be used with or without TLS
1931 encryption. The options can be specified multiple times to
1932 configure multiple channels. The special name "default" can be
1933 used to set the default mode. For channels which are not
1934 explicitly forced into one mode the spice client is allowed to
1935 pick tls/plaintext as he pleases.
1936
1937 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]``
1938 Configure image compression (lossless). Default is auto\_glz.
1939
1940 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]``
1941 Configure wan image compression (lossy for slow links). Default
1942 is auto.
1943
1944 ``streaming-video=[off|all|filter]``
1945 Configure video stream detection. Default is off.
1946
1947 ``agent-mouse=[on|off]``
1948 Enable/disable passing mouse events via vdagent. Default is on.
1949
1950 ``playback-compression=[on|off]``
1951 Enable/disable audio stream compression (using celt 0.5.1).
1952 Default is on.
1953
1954 ``seamless-migration=[on|off]``
1955 Enable/disable spice seamless migration. Default is off.
1956
1957 ``gl=[on|off]``
1958 Enable/disable OpenGL context. Default is off.
1959
1960 ``rendernode=<file>``
1961 DRM render node for OpenGL rendering. If not specified, it will
1962 pick the first available. (Since 2.9)
1963ERST
Gerd Hoffmann29b00402010-03-11 11:13:27 -03001964
blueswir15824d652009-03-28 06:44:27 +00001965DEF("portrait", 0, QEMU_OPTION_portrait,
Blue Swirlad960902010-03-29 19:23:52 +00001966 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1967 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001968SRST
1969``-portrait``
1970 Rotate graphical output 90 deg left (only PXA LCD).
1971ERST
blueswir15824d652009-03-28 06:44:27 +00001972
Vasily Khoruzhick93128052011-06-17 13:04:36 +03001973DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1974 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1975 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001976SRST
1977``-rotate deg``
1978 Rotate graphical output some deg left (only PXA LCD).
1979ERST
Vasily Khoruzhick93128052011-06-17 13:04:36 +03001980
blueswir15824d652009-03-28 06:44:27 +00001981DEF("vga", HAS_ARG, QEMU_OPTION_vga,
Gerd Hoffmanna94f0c52014-09-10 14:28:48 +02001982 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
Blue Swirlad960902010-03-29 19:23:52 +00001983 " select video card type\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001984SRST
1985``-vga type``
1986 Select type of VGA card to emulate. Valid values for type are
1987
1988 ``cirrus``
1989 Cirrus Logic GD5446 Video card. All Windows versions starting
1990 from Windows 95 should recognize and use this graphic card. For
1991 optimal performances, use 16 bit color depth in the guest and
1992 the host OS. (This card was the default before QEMU 2.2)
1993
1994 ``std``
1995 Standard VGA card with Bochs VBE extensions. If your guest OS
1996 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if
1997 you want to use high resolution modes (>= 1280x1024x16) then you
1998 should use this option. (This card is the default since QEMU
1999 2.2)
2000
2001 ``vmware``
2002 VMWare SVGA-II compatible adapter. Use it if you have
2003 sufficiently recent XFree86/XOrg server or Windows guest with a
2004 driver for this card.
2005
2006 ``qxl``
2007 QXL paravirtual graphic card. It is VGA compatible (including
2008 VESA 2.0 VBE support). Works best with qxl guest drivers
2009 installed though. Recommended choice when using the spice
2010 protocol.
2011
2012 ``tcx``
2013 (sun4m only) Sun TCX framebuffer. This is the default
2014 framebuffer for sun4m machines and offers both 8-bit and 24-bit
2015 colour depths at a fixed resolution of 1024x768.
2016
2017 ``cg3``
2018 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit
2019 framebuffer for sun4m machines available in both 1024x768
2020 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people
2021 wishing to run older Solaris versions.
2022
2023 ``virtio``
2024 Virtio VGA card.
2025
2026 ``none``
2027 Disable VGA card.
2028ERST
blueswir15824d652009-03-28 06:44:27 +00002029
2030DEF("full-screen", 0, QEMU_OPTION_full_screen,
Blue Swirlad960902010-03-29 19:23:52 +00002031 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002032SRST
2033``-full-screen``
2034 Start in full screen.
2035ERST
blueswir15824d652009-03-28 06:44:27 +00002036
John Snow60f9a4e2020-02-04 11:56:38 -05002037DEF("g", HAS_ARG, QEMU_OPTION_g ,
Blue Swirlad960902010-03-29 19:23:52 +00002038 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
Laurent Vivier8ac919a2019-10-26 18:45:43 +02002039 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002040SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00002041``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002042 Set the initial graphical resolution and depth (PPC, SPARC only).
2043
2044 For PPC the default is 800x600x32.
2045
2046 For SPARC with the TCX graphics device, the default is 1024x768x8
2047 with the option of 1024x768x24. For cgthree, the default is
2048 1024x768x8 with the option of 1152x900x8 for people who wish to use
2049 OBP.
2050ERST
blueswir15824d652009-03-28 06:44:27 +00002051
2052DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
Robert Hof04ec5a2016-07-26 18:17:11 +08002053 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002054SRST
2055``-vnc display[,option[,option[,...]]]``
2056 Normally, if QEMU is compiled with graphical window support, it
2057 displays output such as guest graphics, guest console, and the QEMU
2058 monitor in a window. With this option, you can have QEMU listen on
2059 VNC display display and redirect the VGA display over the VNC
2060 session. It is very useful to enable the usb tablet device when
2061 using this option (option ``-device usb-tablet``). When using the
2062 VNC display, you must use the ``-k`` parameter to set the keyboard
2063 layout if you are not using en-us. Valid syntax for the display is
2064
2065 ``to=L``
2066 With this option, QEMU will try next available VNC displays,
2067 until the number L, if the origianlly defined "-vnc display" is
2068 not available, e.g. port 5900+display is already used by another
2069 application. By default, to=0.
2070
2071 ``host:d``
2072 TCP connections will only be allowed from host on display d. By
2073 convention the TCP port is 5900+d. Optionally, host can be
2074 omitted in which case the server will accept connections from
2075 any host.
2076
2077 ``unix:path``
2078 Connections will be allowed over UNIX domain sockets where path
2079 is the location of a unix socket to listen for connections on.
2080
2081 ``none``
2082 VNC is initialized but not started. The monitor ``change``
2083 command can be used to later start the VNC server.
2084
2085 Following the display value there may be one or more option flags
2086 separated by commas. Valid options are
2087
2088 ``reverse``
2089 Connect to a listening VNC client via a "reverse" connection.
2090 The client is specified by the display. For reverse network
2091 connections (host:d,``reverse``), the d argument is a TCP port
2092 number, not a display number.
2093
2094 ``websocket``
2095 Opens an additional TCP listening port dedicated to VNC
2096 Websocket connections. If a bare websocket option is given, the
2097 Websocket port is 5700+display. An alternative port can be
2098 specified with the syntax ``websocket``\ =port.
2099
2100 If host is specified connections will only be allowed from this
2101 host. It is possible to control the websocket listen address
2102 independently, using the syntax ``websocket``\ =host:port.
2103
2104 If no TLS credentials are provided, the websocket connection
2105 runs in unencrypted mode. If TLS credentials are provided, the
2106 websocket connection requires encrypted client connections.
2107
2108 ``password``
2109 Require that password based authentication is used for client
2110 connections.
2111
2112 The password must be set separately using the ``set_password``
2113 command in the :ref:`pcsys_005fmonitor`. The
2114 syntax to change your password is:
2115 ``set_password <protocol> <password>`` where <protocol> could be
2116 either "vnc" or "spice".
2117
2118 If you would like to change <protocol> password expiration, you
2119 should use ``expire_password <protocol> <expiration-time>``
2120 where expiration time could be one of the following options:
2121 now, never, +seconds or UNIX time of expiration, e.g. +60 to
2122 make password expire in 60 seconds, or 1335196800 to make
2123 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for
2124 this date and time).
2125
2126 You can also use keywords "now" or "never" for the expiration
2127 time to allow <protocol> password to expire immediately or never
2128 expire.
2129
2130 ``tls-creds=ID``
2131 Provides the ID of a set of TLS credentials to use to secure the
2132 VNC server. They will apply to both the normal VNC server socket
2133 and the websocket socket (if enabled). Setting TLS credentials
2134 will cause the VNC server socket to enable the VeNCrypt auth
2135 mechanism. The credentials should have been previously created
2136 using the ``-object tls-creds`` argument.
2137
2138 ``tls-authz=ID``
2139 Provides the ID of the QAuthZ authorization object against which
2140 the client's x509 distinguished name will validated. This object
2141 is only resolved at time of use, so can be deleted and recreated
2142 on the fly while the VNC server is active. If missing, it will
2143 default to denying access.
2144
2145 ``sasl``
2146 Require that the client use SASL to authenticate with the VNC
2147 server. The exact choice of authentication method used is
2148 controlled from the system / user's SASL configuration file for
2149 the 'qemu' service. This is typically found in
2150 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user,
2151 an environment variable SASL\_CONF\_PATH can be used to make it
2152 search alternate locations for the service config. While some
2153 SASL auth methods can also provide data encryption (eg GSSAPI),
2154 it is recommended that SASL always be combined with the 'tls'
2155 and 'x509' settings to enable use of SSL and server
2156 certificates. This ensures a data encryption preventing
2157 compromise of authentication credentials. See the
2158 :ref:`vnc_005fsecurity` section for details on
2159 using SASL authentication.
2160
2161 ``sasl-authz=ID``
2162 Provides the ID of the QAuthZ authorization object against which
2163 the client's SASL username will validated. This object is only
2164 resolved at time of use, so can be deleted and recreated on the
2165 fly while the VNC server is active. If missing, it will default
2166 to denying access.
2167
2168 ``acl``
2169 Legacy method for enabling authorization of clients against the
2170 x509 distinguished name and SASL username. It results in the
2171 creation of two ``authz-list`` objects with IDs of
2172 ``vnc.username`` and ``vnc.x509dname``. The rules for these
2173 objects must be configured with the HMP ACL commands.
2174
2175 This option is deprecated and should no longer be used. The new
2176 ``sasl-authz`` and ``tls-authz`` options are a replacement.
2177
2178 ``lossy``
2179 Enable lossy compression methods (gradient, JPEG, ...). If this
2180 option is set, VNC client may receive lossy framebuffer updates
2181 depending on its encoding settings. Enabling this option can
2182 save a lot of bandwidth at the expense of quality.
2183
2184 ``non-adaptive``
2185 Disable adaptive encodings. Adaptive encodings are enabled by
2186 default. An adaptive encoding will try to detect frequently
2187 updated screen regions, and send updates in these regions using
2188 a lossy encoding (like JPEG). This can be really helpful to save
2189 bandwidth when playing videos. Disabling adaptive encodings
2190 restores the original static behavior of encodings like Tight.
2191
2192 ``share=[allow-exclusive|force-shared|ignore]``
2193 Set display sharing policy. 'allow-exclusive' allows clients to
2194 ask for exclusive access. As suggested by the rfb spec this is
2195 implemented by dropping other connections. Connecting multiple
2196 clients in parallel requires all clients asking for a shared
2197 session (vncviewer: -shared switch). This is the default.
2198 'force-shared' disables exclusive client access. Useful for
2199 shared desktop sessions, where you don't want someone forgetting
2200 specify -shared disconnect everybody else. 'ignore' completely
2201 ignores the shared flag and allows everybody connect
2202 unconditionally. Doesn't conform to the rfb spec but is
2203 traditional QEMU behavior.
2204
2205 ``key-delay-ms``
2206 Set keyboard delay, for key down and key up events, in
2207 milliseconds. Default is 10. Keyboards are low-bandwidth
2208 devices, so this slowdown can help the device and guest to keep
2209 up and not lose events in case events are arriving in bulk.
2210 Possible causes for the latter are flaky network connections, or
2211 scripts for automated testing.
2212
2213 ``audiodev=audiodev``
2214 Use the specified audiodev when the VNC client requests audio
2215 transmission. When not using an -audiodev argument, this option
2216 must be omitted, otherwise is must be present and specify a
2217 valid audiodev.
2218ERST
blueswir15824d652009-03-28 06:44:27 +00002219
Michael Ellermana3adb7a2011-12-19 17:19:31 +11002220ARCHHEADING(, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002221
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002222ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002223
blueswir15824d652009-03-28 06:44:27 +00002224DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
Blue Swirlad960902010-03-29 19:23:52 +00002225 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
2226 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002227SRST
2228``-win2k-hack``
2229 Use it when installing Windows 2000 to avoid a disk full bug. After
2230 Windows 2000 is installed, you no longer need this option (this
2231 option slows down the IDE transfers).
2232ERST
blueswir15824d652009-03-28 06:44:27 +00002233
blueswir15824d652009-03-28 06:44:27 +00002234DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
Blue Swirlad960902010-03-29 19:23:52 +00002235 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
2236 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002237SRST
2238``-no-fd-bootchk``
2239 Disable boot signature checking for floppy disks in BIOS. May be
2240 needed to boot from old floppy disks.
2241ERST
blueswir15824d652009-03-28 06:44:27 +00002242
blueswir15824d652009-03-28 06:44:27 +00002243DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
Shannon Zhaof5d8c8c2015-05-29 11:28:54 +01002244 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002245SRST
2246``-no-acpi``
2247 Disable ACPI (Advanced Configuration and Power Interface) support.
2248 Use it if your guest OS complains about ACPI problems (PC target
2249 machine only).
2250ERST
blueswir15824d652009-03-28 06:44:27 +00002251
blueswir15824d652009-03-28 06:44:27 +00002252DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
Blue Swirlad960902010-03-29 19:23:52 +00002253 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002254SRST
2255``-no-hpet``
2256 Disable HPET support.
2257ERST
blueswir15824d652009-03-28 06:44:27 +00002258
blueswir15824d652009-03-28 06:44:27 +00002259DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
Michael Tokarev104bf022011-05-12 18:44:17 +04002260 "-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 +00002261 " ACPI table description\n", QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002262SRST
2263``-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]...]``
2264 Add ACPI table with specified header fields and context from
2265 specified files. For file=, take whole ACPI table from the specified
2266 files, including all ACPI headers (possible overridden by other
2267 options). For data=, only data portion of the table is used, all
2268 header information is specified in the command line. If a SLIC table
2269 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id
2270 fields will override the same in the RSDT and the FADT (a.k.a.
2271 FACP), in order to ensure the field matches required by the
2272 Microsoft SLIC spec and the ACPI spec.
2273ERST
blueswir15824d652009-03-28 06:44:27 +00002274
aliguorib6f6e3d2009-04-17 18:59:56 +00002275DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
2276 "-smbios file=binary\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002277 " load SMBIOS entry from binary file\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002278 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
2279 " [,uefi=on|off]\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002280 " specify SMBIOS type 0 fields\n"
aliguorib6f6e3d2009-04-17 18:59:56 +00002281 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2282 " [,uuid=uuid][,sku=str][,family=str]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002283 " specify SMBIOS type 1 fields\n"
2284 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2285 " [,asset=str][,location=str]\n"
2286 " specify SMBIOS type 2 fields\n"
2287 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
2288 " [,sku=str]\n"
2289 " specify SMBIOS type 3 fields\n"
2290 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
Ying Fangc906e032020-08-06 11:56:33 +08002291 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002292 " specify SMBIOS type 4 fields\n"
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002293 "-smbios type=11[,value=str][,path=filename]\n"
2294 " specify SMBIOS type 11 fields\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002295 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
Gabriel L. Somlo3ebd6cc2015-03-11 13:58:01 -04002296 " [,asset=str][,part=str][,speed=%d]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002297 " specify SMBIOS type 17 fields\n",
Wei Huangc30e1562015-09-07 10:39:29 +01002298 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002299SRST
2300``-smbios file=binary``
2301 Load SMBIOS entry from binary file.
2302
2303``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]``
2304 Specify SMBIOS type 0 fields
2305
2306``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]``
2307 Specify SMBIOS type 1 fields
2308
2309``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]``
2310 Specify SMBIOS type 2 fields
2311
2312``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]``
2313 Specify SMBIOS type 3 fields
2314
2315``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str]``
2316 Specify SMBIOS type 4 fields
2317
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002318``-smbios type=11[,value=str][,path=filename]``
2319 Specify SMBIOS type 11 fields
2320
2321 This argument can be repeated multiple times, and values are added in the order they are parsed.
2322 Applications intending to use OEM strings data are encouraged to use their application name as
2323 a prefix for the value string. This facilitates passing information for multiple applications
2324 concurrently.
2325
2326 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax
2327 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes.
2328
2329 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to
2330 the SMBIOS table in the order in which they appear.
2331
2332 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535
2333 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the
2334 guest. Instead it should be used as a indicator to inform the guest where to locate the real
2335 data set, for example, by specifying the serial ID of a block device.
2336
2337 An example passing three strings is
2338
2339 .. parsed-literal::
2340
2341 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\
2342 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\
2343 path=/some/file/with/oemstringsdata.txt
2344
2345 In the guest OS this is visible with the ``dmidecode`` command
2346
2347 .. parsed-literal::
2348
2349 $ dmidecode -t 11
2350 Handle 0x0E00, DMI type 11, 5 bytes
2351 OEM Strings
2352 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/
2353 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os
2354 String 3: myapp:some extra data
2355
2356
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002357``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]``
2358 Specify SMBIOS type 17 fields
2359ERST
aliguorib6f6e3d2009-04-17 18:59:56 +00002360
Markus Armbrusterc70a01e2013-02-13 19:49:40 +01002361DEFHEADING()
blueswir15824d652009-03-28 06:44:27 +00002362
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002363DEFHEADING(Network options:)
blueswir15824d652009-03-28 06:44:27 +00002364
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002365DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
blueswir15824d652009-03-28 06:44:27 +00002366#ifdef CONFIG_SLIRP
Samuel Thibault0b11c032016-03-20 12:29:54 +01002367 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
2368 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
2369 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
Benjamin Drungf18d1372018-02-27 17:06:01 +01002370 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
Fam Zheng0fca92b2018-09-14 15:26:16 +08002371 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002372#ifndef _WIN32
Jan Kiszkac92ef6a2009-06-24 14:42:28 +02002373 "[,smb=dir[,smbserver=addr]]\n"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002374#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002375 " configure a user mode network backend with ID 'str',\n"
2376 " its DHCP server and optional services\n"
blueswir15824d652009-03-28 06:44:27 +00002377#endif
2378#ifdef _WIN32
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002379 "-netdev tap,id=str,ifname=name\n"
2380 " configure a host TAP network backend with ID 'str'\n"
blueswir15824d652009-03-28 06:44:27 +00002381#else
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002382 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002383 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002384 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002385 " [,poll-us=n]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002386 " configure a host TAP network backend with ID 'str'\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002387 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002388 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
2389 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
2390 " to deconfigure it\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002391 " use '[down]script=no' to disable script execution\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002392 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
2393 " configure it\n"
blueswir15824d652009-03-28 06:44:27 +00002394 " use 'fd=h' to connect to an already opened TAP interface\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002395 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002396 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
Michael S. Tsirkinf157ed22011-02-01 14:25:40 +02002397 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002398 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
2399 " 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 +02002400 " use vhost=on to enable experimental in kernel accelerator\n"
mst@redhat.com5430a282011-02-01 22:13:42 +02002401 " (only has effect for virtio guests which use MSIX)\n"
2402 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
Michael S. Tsirkin82b0d802010-03-17 13:08:24 +02002403 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002404 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
Jason Wangec396012013-02-22 22:57:52 +08002405 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002406 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
2407 " spent on busy polling for vhost net\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002408 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
2409 " configure a host TAP network backend with ID 'str' that is\n"
2410 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
2411 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
Mark McLoughlin0df0ff62009-06-18 18:21:34 +01002412#endif
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002413#ifdef __linux__
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002414 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
2415 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
2416 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
2417 " [,rxcookie=rxcookie][,offset=offset]\n"
2418 " configure a network backend with ID 'str' connected to\n"
2419 " an Ethernet over L2TPv3 pseudowire.\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002420 " Linux kernel 3.3+ as well as most routers can talk\n"
Michael Tokarev2f47b402014-07-24 20:10:17 +04002421 " L2TPv3. This transport allows connecting a VM to a VM,\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002422 " VM to a router and even VM to Host. It is a nearly-universal\n"
Stefan Hajnoczi21843dc2020-02-29 11:17:27 +00002423 " standard (RFC3931). Note - this implementation uses static\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002424 " pre-configured tunnels (same as the Linux kernel).\n"
2425 " use 'src=' to specify source address\n"
2426 " use 'dst=' to specify destination address\n"
2427 " use 'udp=on' to specify udp encapsulation\n"
Gonglei39526512014-08-14 14:35:48 +08002428 " use 'srcport=' to specify source udp port\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002429 " use 'dstport=' to specify destination udp port\n"
2430 " use 'ipv6=on' to force v6\n"
2431 " L2TPv3 uses cookies to prevent misconfiguration as\n"
2432 " well as a weak security measure\n"
2433 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
2434 " use 'txcookie=0x012345678' to specify a txcookie\n"
2435 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
2436 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
2437 " use 'pincounter=on' to work around broken counter handling in peer\n"
2438 " use 'offset=X' to add an extra offset between header and data\n"
2439#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002440 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
2441 " configure a network backend to connect to another network\n"
2442 " using a socket connection\n"
2443 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
2444 " configure a network backend to connect to a multicast maddr and port\n"
Mike Ryan3a75e742010-12-01 11:16:47 -08002445 " use 'localaddr=addr' to specify the host address to send packets from\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002446 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
2447 " configure a network backend to connect to another network\n"
2448 " using an UDP tunnel\n"
blueswir15824d652009-03-28 06:44:27 +00002449#ifdef CONFIG_VDE
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002450 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
2451 " configure a network backend to connect to port 'n' of a vde switch\n"
2452 " running on host and listening for incoming connections on 'socketpath'.\n"
blueswir15824d652009-03-28 06:44:27 +00002453 " Use group 'groupname' and mode 'octalmode' to change default\n"
2454 " ownership and permissions for communication port.\n"
2455#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002456#ifdef CONFIG_NETMAP
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002457 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
Vincenzo Maffione58952132013-11-06 11:44:06 +01002458 " attach to the existing netmap-enabled network interface 'name', or to a\n"
2459 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
2460 " netmap device, defaults to '/dev/netmap')\n"
2461#endif
Thomas Huth253dc142018-02-21 11:18:32 +01002462#ifdef CONFIG_POSIX
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002463 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2464 " configure a vhost-user network, backed by a chardev 'dev'\n"
Thomas Huth253dc142018-02-21 11:18:32 +01002465#endif
Cindy Lu108a6482020-07-01 22:55:37 +08002466#ifdef __linux__
2467 "-netdev vhost-vdpa,id=str,vhostdev=/path/to/dev\n"
2468 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n"
2469#endif
Thomas Huth18d65d22018-01-15 20:50:55 +01002470 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002471 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
Thomas Huth78cd6f72018-02-21 11:18:36 +01002472DEF("nic", HAS_ARG, QEMU_OPTION_nic,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002473 "-nic [tap|bridge|"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002474#ifdef CONFIG_SLIRP
2475 "user|"
2476#endif
2477#ifdef __linux__
2478 "l2tpv3|"
2479#endif
2480#ifdef CONFIG_VDE
2481 "vde|"
2482#endif
2483#ifdef CONFIG_NETMAP
2484 "netmap|"
2485#endif
2486#ifdef CONFIG_POSIX
2487 "vhost-user|"
2488#endif
2489 "socket][,option][,...][mac=macaddr]\n"
2490 " initialize an on-board / default host NIC (using MAC address\n"
2491 " macaddr) and connect it to the given host network backend\n"
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002492 "-nic none use it alone to have zero network devices (the default is to\n"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002493 " provided a 'user' network connection)\n",
2494 QEMU_ARCH_ALL)
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002495DEF("net", HAS_ARG, QEMU_OPTION_net,
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002496 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
Thomas Huth0e60a822017-12-19 16:28:55 +01002497 " configure or create an on-board (or machine default) NIC and\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002498 " connect it to hub 0 (please use -nic unless you need a hub)\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002499 "-net ["
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002500#ifdef CONFIG_SLIRP
2501 "user|"
2502#endif
2503 "tap|"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002504 "bridge|"
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002505#ifdef CONFIG_VDE
2506 "vde|"
2507#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002508#ifdef CONFIG_NETMAP
2509 "netmap|"
2510#endif
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002511 "socket][,option][,option][,...]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002512 " old way to initialize a host network interface\n"
2513 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002514SRST
2515``-nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]``
2516 This option is a shortcut for configuring both the on-board
2517 (default) guest NIC hardware and the host network backend in one go.
2518 The host backend options are the same as with the corresponding
2519 ``-netdev`` options below. The guest NIC model can be set with
2520 ``model=modelname``. Use ``model=help`` to list the available device
2521 types. The hardware MAC address can be set with ``mac=macaddr``.
2522
2523 The following two example do exactly the same, to show how ``-nic``
2524 can be used to shorten the command line length:
2525
2526 .. parsed-literal::
2527
2528 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
2529 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2530
2531``-nic none``
2532 Indicate that no network devices should be configured. It is used to
2533 override the default configuration (default NIC with "user" host
2534 network backend) which is activated if no other networking options
2535 are provided.
2536
2537``-netdev user,id=id[,option][,option][,...]``
2538 Configure user mode host network backend which requires no
2539 administrator privilege to run. Valid options are:
2540
2541 ``id=id``
2542 Assign symbolic name for use in monitor commands.
2543
2544 ``ipv4=on|off and ipv6=on|off``
2545 Specify that either IPv4 or IPv6 must be enabled. If neither is
2546 specified both protocols are enabled.
2547
2548 ``net=addr[/mask]``
2549 Set IP network address the guest will see. Optionally specify
2550 the netmask, either in the form a.b.c.d or as number of valid
2551 top-most bits. Default is 10.0.2.0/24.
2552
2553 ``host=addr``
2554 Specify the guest-visible address of the host. Default is the
2555 2nd IP in the guest network, i.e. x.x.x.2.
2556
2557 ``ipv6-net=addr[/int]``
2558 Set IPv6 network address the guest will see (default is
2559 fec0::/64). The network prefix is given in the usual hexadecimal
2560 IPv6 address notation. The prefix size is optional, and is given
2561 as the number of valid top-most bits (default is 64).
2562
2563 ``ipv6-host=addr``
2564 Specify the guest-visible IPv6 address of the host. Default is
2565 the 2nd IPv6 in the guest network, i.e. xxxx::2.
2566
2567 ``restrict=on|off``
2568 If this option is enabled, the guest will be isolated, i.e. it
2569 will not be able to contact the host and no guest IP packets
2570 will be routed over the host to the outside. This option does
2571 not affect any explicitly set forwarding rules.
2572
2573 ``hostname=name``
2574 Specifies the client hostname reported by the built-in DHCP
2575 server.
2576
2577 ``dhcpstart=addr``
2578 Specify the first of the 16 IPs the built-in DHCP server can
2579 assign. Default is the 15th to 31st IP in the guest network,
2580 i.e. x.x.x.15 to x.x.x.31.
2581
2582 ``dns=addr``
2583 Specify the guest-visible address of the virtual nameserver. The
2584 address must be different from the host address. Default is the
2585 3rd IP in the guest network, i.e. x.x.x.3.
2586
2587 ``ipv6-dns=addr``
2588 Specify the guest-visible address of the IPv6 virtual
2589 nameserver. The address must be different from the host address.
2590 Default is the 3rd IP in the guest network, i.e. xxxx::3.
2591
2592 ``dnssearch=domain``
2593 Provides an entry for the domain-search list sent by the
2594 built-in DHCP server. More than one domain suffix can be
2595 transmitted by specifying this option multiple times. If
2596 supported, this will cause the guest to automatically try to
2597 append the given domain suffix(es) in case a domain name can not
2598 be resolved.
2599
2600 Example:
2601
2602 .. parsed-literal::
2603
2604 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2605
2606 ``domainname=domain``
2607 Specifies the client domain name reported by the built-in DHCP
2608 server.
2609
2610 ``tftp=dir``
2611 When using the user mode network stack, activate a built-in TFTP
2612 server. The files in dir will be exposed as the root of a TFTP
2613 server. The TFTP client on the guest must be configured in
2614 binary mode (use the command ``bin`` of the Unix TFTP client).
2615
2616 ``tftp-server-name=name``
2617 In BOOTP reply, broadcast name as the "TFTP server name"
2618 (RFC2132 option 66). This can be used to advise the guest to
2619 load boot files or configurations from a different server than
2620 the host address.
2621
2622 ``bootfile=file``
2623 When using the user mode network stack, broadcast file as the
2624 BOOTP filename. In conjunction with ``tftp``, this can be used
2625 to network boot a guest from a local directory.
2626
2627 Example (using pxelinux):
2628
2629 .. parsed-literal::
2630
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002631 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002632 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2633
2634 ``smb=dir[,smbserver=addr]``
2635 When using the user mode network stack, activate a built-in SMB
2636 server so that Windows OSes can access to the host files in
2637 ``dir`` transparently. The IP address of the SMB server can be
2638 set to addr. By default the 4th IP in the guest network is used,
2639 i.e. x.x.x.4.
2640
2641 In the guest Windows OS, the line:
2642
2643 ::
2644
2645 10.0.2.4 smbserver
2646
2647 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows
2648 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows
2649 NT/2000).
2650
2651 Then ``dir`` can be accessed in ``\\smbserver\qemu``.
2652
2653 Note that a SAMBA server must be installed on the host OS.
2654
2655 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport``
2656 Redirect incoming TCP or UDP connections to the host port
2657 hostport to the guest IP address guestaddr on guest port
2658 guestport. If guestaddr is not specified, its value is x.x.x.15
2659 (default first address given by the built-in DHCP server). By
2660 specifying hostaddr, the rule can be bound to a specific host
2661 interface. If no connection type is set, TCP is used. This
2662 option can be given multiple times.
2663
2664 For example, to redirect host X11 connection from screen 1 to
2665 guest screen 0, use the following:
2666
Peter Maydell09ce5f22020-02-28 15:36:13 +00002667 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002668
2669 # on the host
2670 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2671 # this host xterm should open in the guest X11 server
2672 xterm -display :1
2673
2674 To redirect telnet connections from host port 5555 to telnet
2675 port on the guest, use the following:
2676
Peter Maydell09ce5f22020-02-28 15:36:13 +00002677 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002678
2679 # on the host
2680 |qemu_system| -nic user,hostfwd=tcp::5555-:23
2681 telnet localhost 5555
2682
2683 Then when you use on the host ``telnet localhost 5555``, you
2684 connect to the guest telnet server.
2685
2686 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command``
2687 Forward guest TCP connections to the IP address server on port
2688 port to the character device dev or to a program executed by
2689 cmd:command which gets spawned for each connection. This option
2690 can be given multiple times.
2691
2692 You can either use a chardev directly and have that one used
2693 throughout QEMU's lifetime, like in the following example:
2694
Peter Maydell09ce5f22020-02-28 15:36:13 +00002695 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002696
2697 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2698 # the guest accesses it
2699 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
2700
2701 Or you can execute a command on every TCP connection established
2702 by the guest, so that QEMU behaves similar to an inetd process
2703 for that virtual server:
2704
Peter Maydell09ce5f22020-02-28 15:36:13 +00002705 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002706
2707 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2708 # and connect the TCP stream to its stdin/stdout
2709 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2710
2711``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]``
2712 Configure a host TAP network backend with ID id.
2713
2714 Use the network script file to configure it and the network script
2715 dfile to deconfigure it. If name is not provided, the OS
2716 automatically provides one. The default network configure script is
2717 ``/etc/qemu-ifup`` and the default network deconfigure script is
2718 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to
2719 disable script execution.
2720
2721 If running QEMU as an unprivileged user, use the network helper
Tianjia Zhang8d73ec82020-07-27 12:59:25 +08002722 to configure the TAP interface and attach it to the bridge.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002723 The default network helper executable is
2724 ``/path/to/qemu-bridge-helper`` and the default bridge device is
2725 ``br0``.
2726
2727 ``fd``\ =h can be used to specify the handle of an already opened
2728 host TAP interface.
2729
2730 Examples:
2731
Peter Maydell09ce5f22020-02-28 15:36:13 +00002732 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002733
2734 #launch a QEMU instance with the default network script
2735 |qemu_system| linux.img -nic tap
2736
Peter Maydell09ce5f22020-02-28 15:36:13 +00002737 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002738
2739 #launch a QEMU instance with two NICs, each one connected
2740 #to a TAP device
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002741 |qemu_system| linux.img \\
2742 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002743 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2744
Peter Maydell09ce5f22020-02-28 15:36:13 +00002745 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002746
2747 #launch a QEMU instance with the default network helper to
2748 #connect a TAP device to bridge br0
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002749 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002750 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
2751
2752``-netdev bridge,id=id[,br=bridge][,helper=helper]``
2753 Connect a host TAP network interface to a host bridge device.
2754
2755 Use the network helper helper to configure the TAP interface and
2756 attach it to the bridge. The default network helper executable is
2757 ``/path/to/qemu-bridge-helper`` and the default bridge device is
2758 ``br0``.
2759
2760 Examples:
2761
Peter Maydell09ce5f22020-02-28 15:36:13 +00002762 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002763
2764 #launch a QEMU instance with the default network helper to
2765 #connect a TAP device to bridge br0
2766 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
2767
Peter Maydell09ce5f22020-02-28 15:36:13 +00002768 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002769
2770 #launch a QEMU instance with the default network helper to
2771 #connect a TAP device to bridge qemubr0
2772 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
2773
2774``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]``
2775 This host network backend can be used to connect the guest's network
2776 to another QEMU virtual machine using a TCP socket connection. If
2777 ``listen`` is specified, QEMU waits for incoming connections on port
2778 (host is optional). ``connect`` is used to connect to another QEMU
2779 instance using the ``listen`` option. ``fd``\ =h specifies an
2780 already opened TCP socket.
2781
2782 Example:
2783
Peter Maydell09ce5f22020-02-28 15:36:13 +00002784 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002785
2786 # launch a first QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002787 |qemu_system| linux.img \\
2788 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002789 -netdev socket,id=n1,listen=:1234
2790 # connect the network of this instance to the network of the first instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002791 |qemu_system| linux.img \\
2792 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002793 -netdev socket,id=n2,connect=127.0.0.1:1234
2794
2795``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]``
2796 Configure a socket host network backend to share the guest's network
2797 traffic with another QEMU virtual machines using a UDP multicast
2798 socket, effectively making a bus for every QEMU with same multicast
2799 address maddr and port. NOTES:
2800
2801 1. Several QEMU can be running on different hosts and share same bus
2802 (assuming correct multicast setup for these hosts).
2803
2804 2. mcast support is compatible with User Mode Linux (argument
2805 ``ethN=mcast``), see http://user-mode-linux.sf.net.
2806
2807 3. Use ``fd=h`` to specify an already opened UDP multicast socket.
2808
2809 Example:
2810
Peter Maydell09ce5f22020-02-28 15:36:13 +00002811 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002812
2813 # launch one QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002814 |qemu_system| linux.img \\
2815 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002816 -netdev socket,id=n1,mcast=230.0.0.1:1234
2817 # launch another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002818 |qemu_system| linux.img \\
2819 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002820 -netdev socket,id=n2,mcast=230.0.0.1:1234
2821 # launch yet another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002822 |qemu_system| linux.img \\
2823 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002824 -netdev socket,id=n3,mcast=230.0.0.1:1234
2825
2826 Example (User Mode Linux compat.):
2827
Peter Maydell09ce5f22020-02-28 15:36:13 +00002828 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002829
2830 # launch QEMU instance (note mcast address selected is UML's default)
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002831 |qemu_system| linux.img \\
2832 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002833 -netdev socket,id=n1,mcast=239.192.168.1:1102
2834 # launch UML
2835 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2836
2837 Example (send packets from host's 1.2.3.4):
2838
2839 .. parsed-literal::
2840
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002841 |qemu_system| linux.img \\
2842 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002843 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2844
2845``-netdev l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]``
2846 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931)
2847 is a popular protocol to transport Ethernet (and other Layer 2) data
2848 frames between two systems. It is present in routers, firewalls and
2849 the Linux kernel (from version 3.3 onwards).
2850
2851 This transport allows a VM to communicate to another VM, router or
2852 firewall directly.
2853
2854 ``src=srcaddr``
2855 source address (mandatory)
2856
2857 ``dst=dstaddr``
2858 destination address (mandatory)
2859
2860 ``udp``
2861 select udp encapsulation (default is ip).
2862
2863 ``srcport=srcport``
2864 source udp port.
2865
2866 ``dstport=dstport``
2867 destination udp port.
2868
2869 ``ipv6``
2870 force v6, otherwise defaults to v4.
2871
2872 ``rxcookie=rxcookie``; \ ``txcookie=txcookie``
2873 Cookies are a weak form of security in the l2tpv3 specification.
2874 Their function is mostly to prevent misconfiguration. By default
2875 they are 32 bit.
2876
2877 ``cookie64``
2878 Set cookie size to 64 bit instead of the default 32
2879
2880 ``counter=off``
2881 Force a 'cut-down' L2TPv3 with no counter as in
2882 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2883
2884 ``pincounter=on``
2885 Work around broken counter handling in peer. This may also help
2886 on networks which have packet reorder.
2887
2888 ``offset=offset``
2889 Add an extra offset between header and data
2890
2891 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to
2892 the bridge br-lan on the remote Linux host 1.2.3.4:
2893
Peter Maydell09ce5f22020-02-28 15:36:13 +00002894 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002895
2896 # Setup tunnel on linux host using raw ip as encapsulation
2897 # on 1.2.3.4
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002898 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 +00002899 encap udp udp_sport 16384 udp_dport 16384
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002900 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002901 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2902 ifconfig vmtunnel0 mtu 1500
2903 ifconfig vmtunnel0 up
2904 brctl addif br-lan vmtunnel0
2905
2906
2907 # on 4.3.2.1
2908 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2909
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002910 |qemu_system| linux.img -device e1000,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002911 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2912
2913``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]``
2914 Configure VDE backend to connect to PORT n of a vde switch running
2915 on host and listening for incoming connections on socketpath. Use
2916 GROUP groupname and MODE octalmode to change default ownership and
2917 permissions for communication port. This option is only available if
2918 QEMU has been compiled with vde support enabled.
2919
2920 Example:
2921
Peter Maydell09ce5f22020-02-28 15:36:13 +00002922 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002923
2924 # launch vde switch
2925 vde_switch -F -sock /tmp/myswitch
2926 # launch QEMU instance
2927 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch
2928
2929``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]``
2930 Establish a vhost-user netdev, backed by a chardev id. The chardev
2931 should be a unix domain socket backed one. The vhost-user uses a
2932 specifically defined protocol to pass vhost ioctl replacement
2933 messages to an application on the other end of the socket. On
2934 non-MSIX guests, the feature can be forced with vhostforce. Use
2935 'queues=n' to specify the number of queues to be created for
2936 multiqueue vhost-user.
2937
2938 Example:
2939
2940 ::
2941
2942 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2943 -numa node,memdev=mem \
2944 -chardev socket,id=chr0,path=/path/to/socket \
2945 -netdev type=vhost-user,id=net0,chardev=chr0 \
2946 -device virtio-net-pci,netdev=net0
2947
Cindy Lu108a6482020-07-01 22:55:37 +08002948``-netdev vhost-vdpa,vhostdev=/path/to/dev``
2949 Establish a vhost-vdpa netdev.
2950
2951 vDPA device is a device that uses a datapath which complies with
2952 the virtio specifications with a vendor specific control path.
2953 vDPA devices can be both physically located on the hardware or
2954 emulated by software.
2955
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002956``-netdev hubport,id=id,hubid=hubid[,netdev=nd]``
2957 Create a hub port on the emulated hub with ID hubid.
2958
2959 The hubport netdev lets you connect a NIC to a QEMU emulated hub
2960 instead of a single netdev. Alternatively, you can also connect the
2961 hubport to another netdev with ID nd by using the ``netdev=nd``
2962 option.
2963
2964``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]``
2965 Legacy option to configure or create an on-board (or machine
2966 default) Network Interface Card(NIC) and connect it either to the
2967 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd.
2968 If model is omitted, then the default NIC model associated with the
2969 machine type is used. Note that the default NIC model may change in
2970 future QEMU releases, so it is highly recommended to always specify
2971 a model. Optionally, the MAC address can be changed to mac, the
2972 device address set to addr (PCI cards only), and a name can be
2973 assigned for use in monitor commands. Optionally, for PCI cards, you
2974 can specify the number v of MSI-X vectors that the card should have;
2975 this option currently only affects virtio cards; set v = 0 to
2976 disable MSI-X. If no ``-net`` option is specified, a single NIC is
2977 created. QEMU can emulate several different models of network card.
2978 Use ``-net nic,model=help`` for a list of available devices for your
2979 target.
2980
2981``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]``
2982 Configure a host network backend (with the options corresponding to
2983 the same ``-netdev`` option) and connect it to the emulated hub 0
2984 (the default hub). Use name to specify the name of the hub port.
2985ERST
blueswir15824d652009-03-28 06:44:27 +00002986
Matthew Booth7273a2d2009-10-30 13:41:12 +00002987DEFHEADING()
2988
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002989DEFHEADING(Character device options:)
Matthew Booth7273a2d2009-10-30 13:41:12 +00002990
2991DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
Lin Ma517b3d42016-08-17 01:13:52 +08002992 "-chardev help\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00002993 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Corey Minyard5dd1f022014-10-02 11:17:37 -05002994 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
Julia Suvorova981b06e2018-10-19 01:35:00 +03002995 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n"
Daniel P. Berrangefd4a5fd2019-03-08 15:21:50 +00002996 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n"
Julia Suvorova981b06e2018-10-19 01:35:00 +03002997 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n"
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08002998 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00002999 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
Jan Kiszka97331282010-04-06 16:55:54 +02003000 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003001 " [,logfile=PATH][,logappend=on|off]\n"
3002 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003003 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003004 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3005 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
3006 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3007 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003008#ifdef _WIN32
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003009 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3010 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003011#else
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003012 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3013 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003014#endif
3015#ifdef CONFIG_BRLAPI
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003016 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003017#endif
3018#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
3019 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003020 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3021 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003022#endif
3023#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003024 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3025 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003026#endif
Alon Levycbcc6332011-01-19 10:49:50 +02003027#if defined(CONFIG_SPICE)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003028 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
3029 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
Alon Levycbcc6332011-01-19 10:49:50 +02003030#endif
Blue Swirlad960902010-03-29 19:23:52 +00003031 , QEMU_ARCH_ALL
Matthew Booth7273a2d2009-10-30 13:41:12 +00003032)
3033
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003034SRST
3035The general form of a character device option is:
3036
3037``-chardev backend,id=id[,mux=on|off][,options]``
3038 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``,
3039 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``,
3040 ``pty``, ``stdio``, ``braille``, ``tty``, ``parallel``, ``parport``,
3041 ``spicevmc``, ``spiceport``. The specific backend will determine the
3042 applicable options.
3043
3044 Use ``-chardev help`` to print all available chardev backend types.
3045
3046 All devices must have an id, which can be any string up to 127
3047 characters long. It is used to uniquely identify this device in
3048 other command line directives.
3049
3050 A character device may be used in multiplexing mode by multiple
3051 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is
3052 a "1:N" device, and here the "1" end is your specified chardev
3053 backend, and the "N" end is the various parts of QEMU that can talk
3054 to a chardev. If you create a chardev with ``id=myid`` and
3055 ``mux=on``, QEMU will create a multiplexer with your specified ID,
3056 and you can then configure multiple front ends to use that chardev
3057 ID for their input/output. Up to four different front ends can be
3058 connected to a single multiplexed chardev. (Without multiplexing
3059 enabled, a chardev can only be used by a single front end.) For
3060 instance you could use this to allow a single stdio chardev to be
3061 used by two serial ports and the QEMU monitor:
3062
3063 ::
3064
3065 -chardev stdio,mux=on,id=char0 \
3066 -mon chardev=char0,mode=readline \
3067 -serial chardev:char0 \
3068 -serial chardev:char0
3069
3070 You can have more than one multiplexer in a system configuration;
3071 for instance you could have a TCP port multiplexed between UART 0
3072 and UART 1, and stdio multiplexed between the QEMU monitor and a
3073 parallel port:
3074
3075 ::
3076
3077 -chardev stdio,mux=on,id=char0 \
3078 -mon chardev=char0,mode=readline \
3079 -parallel chardev:char0 \
3080 -chardev tcp,...,mux=on,id=char1 \
3081 -serial chardev:char1 \
3082 -serial chardev:char1
3083
3084 When you're using a multiplexed character device, some escape
3085 sequences are interpreted in the input. See :ref:`mux_005fkeys`.
3086
3087 Note that some other command line options may implicitly create
3088 multiplexed character backends; for instance ``-serial mon:stdio``
3089 creates a multiplexed stdio backend connected to the serial port and
3090 the QEMU monitor, and ``-nographic`` also multiplexes the console
3091 and the monitor to stdio.
3092
3093 There is currently no support for multiplexing in the other
3094 direction (where a single QEMU front end takes input and output from
3095 multiple chardevs).
3096
3097 Every backend supports the ``logfile`` option, which supplies the
3098 path to a file to record all data transmitted via the backend. The
3099 ``logappend`` option controls whether the log file will be truncated
3100 or appended to when opened.
3101
3102The available backends are:
3103
3104``-chardev null,id=id``
3105 A void device. This device will not emit any data, and will drop any
3106 data it receives. The null backend does not take any options.
3107
3108``-chardev socket,id=id[,TCP options or unix options][,server][,nowait][,telnet][,websocket][,reconnect=seconds][,tls-creds=id][,tls-authz=id]``
3109 Create a two-way stream socket, which can be either a TCP or a unix
3110 socket. A unix socket will be created if ``path`` is specified.
3111 Behaviour is undefined if TCP options are specified for a unix
3112 socket.
3113
3114 ``server`` specifies that the socket shall be a listening socket.
3115
3116 ``nowait`` specifies that QEMU should not block waiting for a client
3117 to connect to a listening socket.
3118
3119 ``telnet`` specifies that traffic on the socket should interpret
3120 telnet escape sequences.
3121
3122 ``websocket`` specifies that the socket uses WebSocket protocol for
3123 communication.
3124
3125 ``reconnect`` sets the timeout for reconnecting on non-server
3126 sockets when the remote end goes away. qemu will delay this many
3127 seconds and then attempt to reconnect. Zero disables reconnecting,
3128 and is the default.
3129
3130 ``tls-creds`` requests enablement of the TLS protocol for
3131 encryption, and specifies the id of the TLS credentials to use for
3132 the handshake. The credentials must be previously created with the
3133 ``-object tls-creds`` argument.
3134
3135 ``tls-auth`` provides the ID of the QAuthZ authorization object
3136 against which the client's x509 distinguished name will be
3137 validated. This object is only resolved at time of use, so can be
3138 deleted and recreated on the fly while the chardev server is active.
3139 If missing, it will default to denying access.
3140
3141 TCP and unix socket options are given below:
3142
3143 ``TCP options: port=port[,host=host][,to=to][,ipv4][,ipv6][,nodelay]``
3144 ``host`` for a listening socket specifies the local address to
3145 be bound. For a connecting socket species the remote host to
3146 connect to. ``host`` is optional for listening sockets. If not
3147 specified it defaults to ``0.0.0.0``.
3148
3149 ``port`` for a listening socket specifies the local port to be
3150 bound. For a connecting socket specifies the port on the remote
3151 host to connect to. ``port`` can be given as either a port
3152 number or a service name. ``port`` is required.
3153
3154 ``to`` is only relevant to listening sockets. If it is
3155 specified, and ``port`` cannot be bound, QEMU will attempt to
3156 bind to subsequent ports up to and including ``to`` until it
3157 succeeds. ``to`` must be specified as a port number.
3158
3159 ``ipv4`` and ``ipv6`` specify that either IPv4 or IPv6 must be
3160 used. If neither is specified the socket may use either
3161 protocol.
3162
3163 ``nodelay`` disables the Nagle algorithm.
3164
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003165 ``unix options: path=path[,abstract=on|off][,tight=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003166 ``path`` specifies the local path of the unix socket. ``path``
3167 is required.
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003168 ``abstract`` specifies the use of the abstract socket namespace,
3169 rather than the filesystem. Optional, defaults to false.
3170 ``tight`` sets the socket length of abstract sockets to their minimum,
3171 rather than the full sun_path length. Optional, defaults to true.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003172
3173``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4][,ipv6]``
3174 Sends all traffic from the guest to a remote host over UDP.
3175
3176 ``host`` specifies the remote host to connect to. If not specified
3177 it defaults to ``localhost``.
3178
3179 ``port`` specifies the port on the remote host to connect to.
3180 ``port`` is required.
3181
3182 ``localaddr`` specifies the local address to bind to. If not
3183 specified it defaults to ``0.0.0.0``.
3184
3185 ``localport`` specifies the local port to bind to. If not specified
3186 any available local port will be used.
3187
3188 ``ipv4`` and ``ipv6`` specify that either IPv4 or IPv6 must be used.
3189 If neither is specified the device may use either protocol.
3190
3191``-chardev msmouse,id=id``
3192 Forward QEMU's emulated msmouse events to the guest. ``msmouse``
3193 does not take any options.
3194
3195``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]``
3196 Connect to a QEMU text console. ``vc`` may optionally be given a
3197 specific size.
3198
3199 ``width`` and ``height`` specify the width and height respectively
3200 of the console, in pixels.
3201
3202 ``cols`` and ``rows`` specify that the console be sized to fit a
3203 text console with the given dimensions.
3204
3205``-chardev ringbuf,id=id[,size=size]``
3206 Create a ring buffer with fixed size ``size``. size must be a power
3207 of two and defaults to ``64K``.
3208
3209``-chardev file,id=id,path=path``
3210 Log all traffic received from the guest to a file.
3211
3212 ``path`` specifies the path of the file to be opened. This file will
3213 be created if it does not already exist, and overwritten if it does.
3214 ``path`` is required.
3215
3216``-chardev pipe,id=id,path=path``
3217 Create a two-way connection to the guest. The behaviour differs
3218 slightly between Windows hosts and other hosts:
3219
3220 On Windows, a single duplex pipe will be created at
3221 ``\\.pipe\path``.
3222
3223 On other hosts, 2 pipes will be created called ``path.in`` and
3224 ``path.out``. Data written to ``path.in`` will be received by the
3225 guest. Data written by the guest can be read from ``path.out``. QEMU
3226 will not create these fifos, and requires them to be present.
3227
3228 ``path`` forms part of the pipe path as described above. ``path`` is
3229 required.
3230
3231``-chardev console,id=id``
3232 Send traffic from the guest to QEMU's standard output. ``console``
3233 does not take any options.
3234
3235 ``console`` is only available on Windows hosts.
3236
3237``-chardev serial,id=id,path=path``
3238 Send traffic from the guest to a serial device on the host.
3239
3240 On Unix hosts serial will actually accept any tty device, not only
3241 serial lines.
3242
3243 ``path`` specifies the name of the serial device to open.
3244
3245``-chardev pty,id=id``
3246 Create a new pseudo-terminal on the host and connect to it. ``pty``
3247 does not take any options.
3248
3249 ``pty`` is not available on Windows hosts.
3250
3251``-chardev stdio,id=id[,signal=on|off]``
3252 Connect to standard input and standard output of the QEMU process.
3253
3254 ``signal`` controls if signals are enabled on the terminal, that
3255 includes exiting QEMU with the key sequence Control-c. This option
3256 is enabled by default, use ``signal=off`` to disable it.
3257
3258``-chardev braille,id=id``
3259 Connect to a local BrlAPI server. ``braille`` does not take any
3260 options.
3261
3262``-chardev tty,id=id,path=path``
3263 ``tty`` is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD
3264 and DragonFlyBSD hosts. It is an alias for ``serial``.
3265
3266 ``path`` specifies the path to the tty. ``path`` is required.
3267
Peter Maydell09ce5f22020-02-28 15:36:13 +00003268``-chardev parallel,id=id,path=path``
3269 \
3270``-chardev parport,id=id,path=path``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003271 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD
3272 hosts.
3273
3274 Connect to a local parallel port.
3275
3276 ``path`` specifies the path to the parallel port device. ``path`` is
3277 required.
3278
3279``-chardev spicevmc,id=id,debug=debug,name=name``
3280 ``spicevmc`` is only available when spice support is built in.
3281
3282 ``debug`` debug level for spicevmc
3283
3284 ``name`` name of spice channel to connect to
3285
3286 Connect to a spice virtual machine channel, such as vdiport.
3287
3288``-chardev spiceport,id=id,debug=debug,name=name``
3289 ``spiceport`` is only available when spice support is built in.
3290
3291 ``debug`` debug level for spicevmc
3292
3293 ``name`` name of spice port to connect to
3294
3295 Connect to a spice port, allowing a Spice client to handle the
3296 traffic identified by a name (preferably a fqdn).
3297ERST
Matthew Booth7273a2d2009-10-30 13:41:12 +00003298
3299DEFHEADING()
3300
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003301#ifdef CONFIG_TPM
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003302DEFHEADING(TPM device options:)
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003303
3304DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
Stefan Berger92dcc232013-02-27 12:47:54 -05003305 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
3306 " use path to provide path to a character device; default is /dev/tpm0\n"
3307 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
Amarnath Vallurif4ede812017-09-29 14:10:20 +03003308 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
3309 "-tpmdev emulator,id=id,chardev=dev\n"
3310 " configure the TPM device using chardev backend\n",
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003311 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003312SRST
3313The general form of a TPM device option is:
3314
3315``-tpmdev backend,id=id[,options]``
3316 The specific backend type will determine the applicable options. The
3317 ``-tpmdev`` option creates the TPM backend and requires a
3318 ``-device`` option that specifies the TPM frontend interface model.
3319
3320 Use ``-tpmdev help`` to print all available TPM backend types.
3321
3322The available backends are:
3323
3324``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path``
3325 (Linux-host only) Enable access to the host's TPM using the
3326 passthrough driver.
3327
3328 ``path`` specifies the path to the host's TPM device, i.e., on a
3329 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by
3330 default ``/dev/tpm0`` is used.
3331
3332 ``cancel-path`` specifies the path to the host TPM device's sysfs
3333 entry allowing for cancellation of an ongoing TPM command.
3334 ``cancel-path`` is optional and by default QEMU will search for the
3335 sysfs entry to use.
3336
3337 Some notes about using the host's TPM with the passthrough driver:
3338
3339 The TPM device accessed by the passthrough driver must not be used
3340 by any other application on the host.
3341
3342 Since the host's firmware (BIOS/UEFI) has already initialized the
3343 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize
3344 the TPM again and may therefore not show a TPM-specific menu that
3345 would otherwise allow the user to configure the TPM, e.g., allow the
3346 user to enable/disable or activate/deactivate the TPM. Further, if
3347 TPM ownership is released from within a VM then the host's TPM will
3348 get disabled and deactivated. To enable and activate the TPM again
3349 afterwards, the host has to be rebooted and the user is required to
3350 enter the firmware's menu to enable and activate the TPM. If the TPM
3351 is left disabled and/or deactivated most TPM commands will fail.
3352
3353 To create a passthrough TPM use the following two options:
3354
3355 ::
3356
3357 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
3358
3359 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by
3360 ``tpmdev=tpm0`` in the device option.
3361
3362``-tpmdev emulator,id=id,chardev=dev``
3363 (Linux-host only) Enable access to a TPM emulator using Unix domain
3364 socket based chardev backend.
3365
3366 ``chardev`` specifies the unique ID of a character device backend
3367 that provides connection to the software TPM server.
3368
3369 To create a TPM emulator backend device with chardev socket backend:
3370
3371 ::
3372
3373 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
3374ERST
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003375
3376DEFHEADING()
3377
3378#endif
3379
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003380DEFHEADING(Linux/Multiboot boot specific:)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003381SRST
3382When using these options, you can use a given Linux or Multiboot kernel
3383without installing it in the disk image. It can be useful for easier
3384testing of various kernels.
3385
3386
3387ERST
blueswir15824d652009-03-28 06:44:27 +00003388
3389DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
Blue Swirlad960902010-03-29 19:23:52 +00003390 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003391SRST
3392``-kernel bzImage``
3393 Use bzImage as kernel image. The kernel can be either a Linux kernel
3394 or in multiboot format.
3395ERST
blueswir15824d652009-03-28 06:44:27 +00003396
3397DEF("append", HAS_ARG, QEMU_OPTION_append, \
Blue Swirlad960902010-03-29 19:23:52 +00003398 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003399SRST
3400``-append cmdline``
3401 Use cmdline as kernel command line
3402ERST
blueswir15824d652009-03-28 06:44:27 +00003403
3404DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
Blue Swirlad960902010-03-29 19:23:52 +00003405 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003406SRST
3407``-initrd file``
3408 Use file as initial ram disk.
3409
3410``-initrd "file1 arg=foo,file2"``
3411 This syntax is only available with multiboot.
3412
3413 Use file1 and file2 as modules and pass arg=foo as parameter to the
3414 first module.
3415ERST
blueswir15824d652009-03-28 06:44:27 +00003416
Grant Likely412beee2012-03-02 11:56:38 +00003417DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
Peter A. G. Crosthwaite379b5c72012-03-04 21:03:54 +10003418 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003419SRST
3420``-dtb file``
3421 Use file as a device tree binary (dtb) image and pass it to the
3422 kernel on boot.
3423ERST
Grant Likely412beee2012-03-02 11:56:38 +00003424
blueswir15824d652009-03-28 06:44:27 +00003425DEFHEADING()
3426
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003427DEFHEADING(Debug/Expert options:)
blueswir15824d652009-03-28 06:44:27 +00003428
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04003429DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3430 "-fw_cfg [name=]<name>,file=<file>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02003431 " add named fw_cfg entry with contents from file\n"
Gabriel L. Somlo6407d762015-09-29 12:29:01 -04003432 "-fw_cfg [name=]<name>,string=<str>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02003433 " add named fw_cfg entry with contents from string\n",
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04003434 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003435SRST
3436``-fw_cfg [name=]name,file=file``
3437 Add named fw\_cfg entry with contents from file file.
3438
3439``-fw_cfg [name=]name,string=str``
3440 Add named fw\_cfg entry with contents from string str.
3441
3442 The terminating NUL character of the contents of str will not be
3443 included as part of the fw\_cfg item data. To insert contents with
3444 embedded NUL characters, you have to use the file parameter.
3445
3446 The fw\_cfg entries are passed by QEMU through to the guest.
3447
3448 Example:
3449
3450 ::
3451
3452 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3453
3454 creates an fw\_cfg entry named opt/com.mycompany/blob with contents
3455 from ./my\_blob.bin.
3456ERST
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04003457
blueswir15824d652009-03-28 06:44:27 +00003458DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
Blue Swirlad960902010-03-29 19:23:52 +00003459 "-serial dev redirect the serial port to char device 'dev'\n",
3460 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003461SRST
3462``-serial dev``
3463 Redirect the virtual serial port to host character device dev. The
3464 default device is ``vc`` in graphical mode and ``stdio`` in non
3465 graphical mode.
3466
3467 This option can be used several times to simulate up to 4 serial
3468 ports.
3469
3470 Use ``-serial none`` to disable all serial ports.
3471
3472 Available character devices are:
3473
3474 ``vc[:WxH]``
3475 Virtual console. Optionally, a width and height can be given in
3476 pixel with
3477
3478 ::
3479
3480 vc:800x600
3481
3482 It is also possible to specify width or height in characters:
3483
3484 ::
3485
3486 vc:80Cx24C
3487
3488 ``pty``
3489 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3490
3491 ``none``
3492 No device is allocated.
3493
3494 ``null``
3495 void device
3496
3497 ``chardev:id``
3498 Use a named character device defined with the ``-chardev``
3499 option.
3500
3501 ``/dev/XXX``
3502 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial
3503 port parameters are set according to the emulated ones.
3504
3505 ``/dev/parportN``
3506 [Linux only, parallel port only] Use host parallel port N.
3507 Currently SPP and EPP parallel port features can be used.
3508
3509 ``file:filename``
3510 Write output to filename. No character can be read.
3511
3512 ``stdio``
3513 [Unix only] standard input/output
3514
3515 ``pipe:filename``
3516 name pipe filename
3517
3518 ``COMn``
3519 [Windows only] Use host serial port n
3520
3521 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]``
3522 This implements UDP Net Console. When remote\_host or src\_ip
3523 are not specified they default to ``0.0.0.0``. When not using a
3524 specified src\_port a random port is automatically chosen.
3525
3526 If you just want a simple readonly console you can use
3527 ``netcat`` or ``nc``, by starting QEMU with:
3528 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time
3529 QEMU writes something to that port it will appear in the
3530 netconsole session.
3531
3532 If you plan to send characters back via netconsole or you want
3533 to stop and start QEMU a lot of times, you should have QEMU use
3534 the same source port each time by using something like ``-serial
3535 udp::4555@:4556`` to QEMU. Another approach is to use a patched
3536 version of netcat which can listen to a TCP port and send and
3537 receive characters via udp. If you have a patched version of
3538 netcat which activates telnet remote echo and single char
3539 transfer, then you can use the following options to set up a
3540 netcat redirector to allow telnet on port 5555 to access the
3541 QEMU port.
3542
3543 ``QEMU Options:``
3544 -serial udp::4555@:4556
3545
3546 ``netcat options:``
3547 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3548
3549 ``telnet options:``
3550 localhost 5555
3551
3552 ``tcp:[host]:port[,server][,nowait][,nodelay][,reconnect=seconds]``
3553 The TCP Net Console has two modes of operation. It can send the
3554 serial I/O to a location or wait for a connection from a
3555 location. By default the TCP Net Console is sent to host at the
3556 port. If you use the server option QEMU will wait for a client
3557 socket application to connect to the port before continuing,
3558 unless the ``nowait`` option was specified. The ``nodelay``
3559 option disables the Nagle buffering algorithm. The ``reconnect``
3560 option only applies if noserver is set, if the connection goes
3561 down it will attempt to reconnect at the given interval. If host
3562 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a
3563 time is accepted. You can use ``telnet`` to connect to the
3564 corresponding character device.
3565
3566 ``Example to send tcp console to 192.168.0.2 port 4444``
3567 -serial tcp:192.168.0.2:4444
3568
3569 ``Example to listen and wait on port 4444 for connection``
3570 -serial tcp::4444,server
3571
3572 ``Example to not wait and listen on ip 192.168.0.100 port 4444``
3573 -serial tcp:192.168.0.100:4444,server,nowait
3574
3575 ``telnet:host:port[,server][,nowait][,nodelay]``
3576 The telnet protocol is used instead of raw tcp sockets. The
3577 options work the same as if you had specified ``-serial tcp``.
3578 The difference is that the port acts like a telnet server or
3579 client using telnet option negotiation. This will also allow you
3580 to send the MAGIC\_SYSRQ sequence if you use a telnet that
3581 supports sending the break sequence. Typically in unix telnet
3582 you do it with Control-] and then type "send break" followed by
3583 pressing the enter key.
3584
3585 ``websocket:host:port,server[,nowait][,nodelay]``
3586 The WebSocket protocol is used instead of raw tcp socket. The
3587 port acts as a WebSocket server. Client mode is not supported.
3588
3589 ``unix:path[,server][,nowait][,reconnect=seconds]``
3590 A unix domain socket is used instead of a tcp socket. The option
3591 works the same as if you had specified ``-serial tcp`` except
3592 the unix domain socket path is used for connections.
3593
3594 ``mon:dev_string``
3595 This is a special option to allow the monitor to be multiplexed
3596 onto another serial port. The monitor is accessed with key
3597 sequence of Control-a and then pressing c. dev\_string should be
3598 any one of the serial devices specified above. An example to
3599 multiplex the monitor onto a telnet server listening on port
3600 4444 would be:
3601
3602 ``-serial mon:telnet::4444,server,nowait``
3603
3604 When the monitor is multiplexed to stdio in this way, Ctrl+C
3605 will not terminate QEMU any more but will be passed to the guest
3606 instead.
3607
3608 ``braille``
3609 Braille device. This will use BrlAPI to display the braille
3610 output on a real or fake device.
3611
3612 ``msmouse``
3613 Three button serial mouse. Configure the guest to use Microsoft
3614 protocol.
3615ERST
blueswir15824d652009-03-28 06:44:27 +00003616
3617DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
Blue Swirlad960902010-03-29 19:23:52 +00003618 "-parallel dev redirect the parallel port to char device 'dev'\n",
3619 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003620SRST
3621``-parallel dev``
3622 Redirect the virtual parallel port to host device dev (same devices
3623 as the serial port). On Linux hosts, ``/dev/parportN`` can be used
3624 to use hardware devices connected on the corresponding host parallel
3625 port.
3626
3627 This option can be used several times to simulate up to 3 parallel
3628 ports.
3629
3630 Use ``-parallel none`` to disable all parallel ports.
3631ERST
blueswir15824d652009-03-28 06:44:27 +00003632
3633DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
Blue Swirlad960902010-03-29 19:23:52 +00003634 "-monitor dev redirect the monitor to char device 'dev'\n",
3635 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003636SRST
3637``-monitor dev``
3638 Redirect the monitor to host device dev (same devices as the serial
3639 port). The default device is ``vc`` in graphical mode and ``stdio``
3640 in non graphical mode. Use ``-monitor none`` to disable the default
3641 monitor.
3642ERST
Gerd Hoffmann6ca55822009-12-08 13:11:52 +01003643DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
Blue Swirlad960902010-03-29 19:23:52 +00003644 "-qmp dev like -monitor but opens in 'control' mode\n",
3645 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003646SRST
3647``-qmp dev``
3648 Like -monitor but opens in 'control' mode.
3649ERST
Max Reitz4821cd42014-11-17 13:31:04 +01003650DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3651 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3652 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003653SRST
3654``-qmp-pretty dev``
3655 Like -qmp but uses pretty JSON formatting.
3656ERST
blueswir15824d652009-03-28 06:44:27 +00003657
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01003658DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
Vicente Jimenez Aguilaref670722017-11-14 09:11:27 +01003659 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003660SRST
3661``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]``
3662 Setup monitor on chardev name. ``pretty`` turns on JSON pretty
3663 printing easing human reading and debugging.
3664ERST
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01003665
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08003666DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
Blue Swirlad960902010-03-29 19:23:52 +00003667 "-debugcon dev redirect the debug console to char device 'dev'\n",
3668 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003669SRST
3670``-debugcon dev``
3671 Redirect the debug console to host device dev (same devices as the
3672 serial port). The debug console is an I/O port which is typically
3673 port 0xe9; writing to that I/O port sends output to this device. The
3674 default device is ``vc`` in graphical mode and ``stdio`` in non
3675 graphical mode.
3676ERST
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08003677
blueswir15824d652009-03-28 06:44:27 +00003678DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
Blue Swirlad960902010-03-29 19:23:52 +00003679 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003680SRST
3681``-pidfile file``
3682 Store the QEMU process PID in file. It is useful if you launch QEMU
3683 from a script.
3684ERST
blueswir15824d652009-03-28 06:44:27 +00003685
aurel321b530a62009-04-05 20:08:59 +00003686DEF("singlestep", 0, QEMU_OPTION_singlestep, \
Blue Swirlad960902010-03-29 19:23:52 +00003687 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003688SRST
3689``-singlestep``
3690 Run the emulation in single step mode.
3691ERST
aurel321b530a62009-04-05 20:08:59 +00003692
Igor Mammedov047f7032018-05-11 19:24:43 +02003693DEF("preconfig", 0, QEMU_OPTION_preconfig, \
Markus Armbruster361ac942018-07-05 11:14:02 +02003694 "--preconfig pause QEMU before machine is initialized (experimental)\n",
Igor Mammedov047f7032018-05-11 19:24:43 +02003695 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003696SRST
3697``--preconfig``
3698 Pause QEMU for interactive configuration before the machine is
3699 created, which allows querying and configuring properties that will
3700 affect machine initialization. Use QMP command 'x-exit-preconfig' to
3701 exit the preconfig state and move to the next state (i.e. run guest
3702 if -S isn't used or pause the second time if -S is used). This
3703 option is experimental.
3704ERST
Igor Mammedov047f7032018-05-11 19:24:43 +02003705
blueswir15824d652009-03-28 06:44:27 +00003706DEF("S", 0, QEMU_OPTION_S, \
Blue Swirlad960902010-03-29 19:23:52 +00003707 "-S freeze CPU at startup (use 'c' to start execution)\n",
3708 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003709SRST
3710``-S``
3711 Do not start CPU at startup (you must type 'c' in the monitor).
3712ERST
blueswir15824d652009-03-28 06:44:27 +00003713
Satoru Moriya888a6bc2013-04-19 16:42:06 +02003714DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3715 "-realtime [mlock=on|off]\n"
3716 " run qemu with realtime features\n"
3717 " mlock=on|off controls mlock support (default: on)\n",
3718 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003719SRST
3720``-realtime mlock=on|off``
3721 Run qemu with realtime features. mlocking qemu and guest memory can
3722 be enabled via ``mlock=on`` (enabled by default).
3723ERST
Satoru Moriya888a6bc2013-04-19 16:42:06 +02003724
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03003725DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02003726 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n"
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03003727 " run qemu with overcommit hints\n"
3728 " mem-lock=on|off controls memory lock support (default: off)\n"
3729 " cpu-pm=on|off controls cpu power management (default: off)\n",
3730 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003731SRST
3732``-overcommit mem-lock=on|off``
Peter Maydell09ce5f22020-02-28 15:36:13 +00003733 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003734``-overcommit cpu-pm=on|off``
3735 Run qemu with hints about host resource overcommit. The default is
3736 to assume that host overcommits all resources.
3737
3738 Locking qemu and guest memory can be enabled via ``mem-lock=on``
3739 (disabled by default). This works when host memory is not
3740 overcommitted and reduces the worst-case latency for guest. This is
3741 equivalent to ``realtime``.
3742
3743 Guest ability to manage power state of host cpus (increasing latency
3744 for other processes on the same host cpu, but decreasing latency for
3745 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This
3746 works best when host CPU is not overcommitted. When used, host
3747 estimates of CPU cycle and power utilization will be incorrect, not
3748 taking into account guest idle time.
3749ERST
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03003750
aliguori59030a82009-04-05 18:43:41 +00003751DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
Peter Maydelle5910d42020-04-03 10:40:14 +01003752 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n"
3753 " the guest without waiting for gdb to connect; use -S too\n"
3754 " if you want it to not start execution.)\n",
3755 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003756SRST
3757``-gdb dev``
Peter Maydelle5910d42020-04-03 10:40:14 +01003758 Accept a gdb connection on device dev (see
3759 :ref:`gdb_005fusage`). Note that this option does not pause QEMU
3760 execution -- if you want QEMU to not start the guest until you
3761 connect with gdb and issue a ``continue`` command, you will need to
3762 also pass the ``-S`` option to QEMU.
3763
3764 The most usual configuration is to listen on a local TCP socket::
3765
3766 -gdb tcp::3117
3767
3768 but you can specify other backends; UDP, pseudo TTY, or even stdio
3769 are all reasonable use cases. For example, a stdio connection
3770 allows you to start QEMU from within gdb and establish the
3771 connection via a pipe:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003772
Peter Maydell09ce5f22020-02-28 15:36:13 +00003773 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003774
3775 (gdb) target remote | exec |qemu_system| -gdb stdio ...
3776ERST
blueswir15824d652009-03-28 06:44:27 +00003777
aliguori59030a82009-04-05 18:43:41 +00003778DEF("s", 0, QEMU_OPTION_s, \
Blue Swirlad960902010-03-29 19:23:52 +00003779 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3780 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003781SRST
3782``-s``
3783 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3784 (see :ref:`gdb_005fusage`).
3785ERST
blueswir15824d652009-03-28 06:44:27 +00003786
3787DEF("d", HAS_ARG, QEMU_OPTION_d, \
Peter Maydell989b6972013-02-26 17:52:40 +00003788 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
Blue Swirlad960902010-03-29 19:23:52 +00003789 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003790SRST
3791``-d item1[,...]``
3792 Enable logging of specified items. Use '-d help' for a list of log
3793 items.
3794ERST
blueswir15824d652009-03-28 06:44:27 +00003795
Matthew Fernandezc235d732011-06-07 16:32:40 +00003796DEF("D", HAS_ARG, QEMU_OPTION_D, \
Peter Maydell989b6972013-02-26 17:52:40 +00003797 "-D logfile output log to logfile (default stderr)\n",
Matthew Fernandezc235d732011-06-07 16:32:40 +00003798 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003799SRST
3800``-D logfile``
3801 Output log in logfile instead of to stderr
3802ERST
Matthew Fernandezc235d732011-06-07 16:32:40 +00003803
Alex Bennée35145522016-03-15 14:30:20 +00003804DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3805 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3806 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003807SRST
3808``-dfilter range1[,...]``
3809 Filter debug output to that relevant to a range of target addresses.
3810 The filter spec can be either start+size, start-size or start..end
3811 where start end and size are the addresses and sizes required. For
3812 example:
3813
3814 ::
3815
3816 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3817
3818 Will dump output for any code in the 0x1000 sized block starting at
3819 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and
3820 another 0x1000 sized block starting at 0xffffffc00005f000.
3821ERST
Alex Bennée35145522016-03-15 14:30:20 +00003822
Richard Henderson9c09a252019-03-14 13:06:29 -07003823DEF("seed", HAS_ARG, QEMU_OPTION_seed, \
3824 "-seed number seed the pseudo-random number generator\n",
3825 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003826SRST
3827``-seed number``
3828 Force the guest to use a deterministic pseudo-random number
3829 generator, seeded with number. This does not affect crypto routines
3830 within the host.
3831ERST
Richard Henderson9c09a252019-03-14 13:06:29 -07003832
blueswir15824d652009-03-28 06:44:27 +00003833DEF("L", HAS_ARG, QEMU_OPTION_L, \
Blue Swirlad960902010-03-29 19:23:52 +00003834 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
3835 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003836SRST
3837``-L path``
3838 Set the directory for the BIOS, VGA BIOS and keymaps.
3839
3840 To list all the data directories, use ``-L help``.
3841ERST
blueswir15824d652009-03-28 06:44:27 +00003842
3843DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
Blue Swirlad960902010-03-29 19:23:52 +00003844 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003845SRST
3846``-bios file``
3847 Set the filename for the BIOS.
3848ERST
blueswir15824d652009-03-28 06:44:27 +00003849
blueswir15824d652009-03-28 06:44:27 +00003850DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
Blue Swirlad960902010-03-29 19:23:52 +00003851 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003852SRST
3853``-enable-kvm``
3854 Enable KVM full virtualization support. This option is only
3855 available if KVM support is enabled when compiling.
3856ERST
blueswir15824d652009-03-28 06:44:27 +00003857
aliguorie37630c2009-04-22 15:19:10 +00003858DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
Blue Swirlad960902010-03-29 19:23:52 +00003859 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
aliguorie37630c2009-04-22 15:19:10 +00003860DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3861 "-xen-attach attach to existing xen domain\n"
Anthony PERARD1077bca2018-09-14 12:18:30 +01003862 " libxl will use this when starting QEMU\n",
Blue Swirlad960902010-03-29 19:23:52 +00003863 QEMU_ARCH_ALL)
Paul Durrant1c599472017-03-22 09:39:15 +00003864DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3865 "-xen-domid-restrict restrict set of available xen operations\n"
3866 " to specified domain id. (Does not affect\n"
3867 " xenpv machine type).\n",
3868 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003869SRST
3870``-xen-domid id``
3871 Specify xen guest domain id (XEN only).
3872
3873``-xen-attach``
3874 Attach to existing xen domain. libxl will use this when starting
3875 QEMU (XEN only). Restrict set of available xen operations to
3876 specified domain id (XEN only).
3877ERST
aliguorie37630c2009-04-22 15:19:10 +00003878
blueswir15824d652009-03-28 06:44:27 +00003879DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
Blue Swirlad960902010-03-29 19:23:52 +00003880 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003881SRST
3882``-no-reboot``
3883 Exit instead of rebooting.
3884ERST
blueswir15824d652009-03-28 06:44:27 +00003885
3886DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
Blue Swirlad960902010-03-29 19:23:52 +00003887 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003888SRST
3889``-no-shutdown``
3890 Don't exit QEMU on guest shutdown, but instead only stop the
3891 emulation. This allows for instance switching to monitor to commit
3892 changes to the disk image.
3893ERST
blueswir15824d652009-03-28 06:44:27 +00003894
3895DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3896 "-loadvm [tag|id]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00003897 " start right away with a saved state (loadvm in monitor)\n",
3898 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003899SRST
3900``-loadvm file``
3901 Start right away with a saved state (``loadvm`` in monitor)
3902ERST
blueswir15824d652009-03-28 06:44:27 +00003903
3904#ifndef _WIN32
3905DEF("daemonize", 0, QEMU_OPTION_daemonize, \
Blue Swirlad960902010-03-29 19:23:52 +00003906 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00003907#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003908SRST
3909``-daemonize``
3910 Daemonize the QEMU process after initialization. QEMU will not
3911 detach from standard IO until it is ready to receive connections on
3912 any of its devices. This option is a useful way for external
3913 programs to launch QEMU without having to cope with initialization
3914 race conditions.
3915ERST
blueswir15824d652009-03-28 06:44:27 +00003916
3917DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
Blue Swirlad960902010-03-29 19:23:52 +00003918 "-option-rom rom load a file, rom, into the option ROM space\n",
3919 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003920SRST
3921``-option-rom file``
3922 Load the contents of file as an option ROM. This option is useful to
3923 load things like EtherBoot.
3924ERST
blueswir15824d652009-03-28 06:44:27 +00003925
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02003926DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
Artem Pisarenko238d1242018-10-18 13:12:52 +06003927 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00003928 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3929 QEMU_ARCH_ALL)
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02003930
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003931SRST
3932``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]``
3933 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at
3934 the current UTC or local time, respectively. ``localtime`` is
3935 required for correct date in MS-DOS or Windows. To start at a
3936 specific point in time, provide datetime in the format
3937 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC.
3938
3939 By default the RTC is driven by the host system time. This allows
3940 using of the RTC as accurate reference clock inside the guest,
3941 specifically if the host time is smoothly following an accurate
3942 external reference clock, e.g. via NTP. If you want to isolate the
3943 guest time from the host, you can set ``clock`` to ``rt`` instead,
3944 which provides a host monotonic clock if host support it. To even
3945 prevent the RTC from progressing during suspension, you can set
3946 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is
3947 recommended especially in icount mode in order to preserve
3948 determinism; however, note that in icount mode the speed of the
3949 virtual clock is variable and can in general differ from the host
3950 clock.
3951
3952 Enable ``driftfix`` (i386 targets only) if you experience time drift
3953 problems, specifically with Windows' ACPI HAL. This option will try
3954 to figure out how many timer interrupts were not processed by the
3955 Windows guest and will re-inject them.
3956ERST
blueswir15824d652009-03-28 06:44:27 +00003957
3958DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
Pavel Dovgalyuk9c2037d2017-01-24 10:17:47 +03003959 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
aliguoribc14ca22009-04-05 18:43:37 +00003960 " enable virtual instruction counter with 2^N clock ticks per\n" \
Victor CLEMENTf1f4b572015-05-29 17:14:05 +02003961 " instruction, enable aligning the host and virtual clocks\n" \
3962 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003963SRST
3964``-icount [shift=N|auto][,rr=record|replay,rrfile=filename,rrsnapshot=snapshot]``
3965 Enable virtual instruction counter. The virtual cpu will execute one
3966 instruction every 2^N ns of virtual time. If ``auto`` is specified
3967 then the virtual cpu speed will be automatically adjusted to keep
3968 virtual time within a few seconds of real time.
3969
3970 When the virtual cpu is sleeping, the virtual time will advance at
3971 default speed unless ``sleep=on|off`` is specified. With
3972 ``sleep=on|off``, the virtual time will jump to the next timer
3973 deadline instantly whenever the virtual cpu goes to sleep mode and
3974 will not advance if no timer is enabled. This behavior give
3975 deterministic execution times from the guest point of view.
3976
3977 Note that while this option can give deterministic behavior, it does
3978 not provide cycle accurate emulation. Modern CPUs contain
3979 superscalar out of order cores with complex cache hierarchies. The
3980 number of instructions executed often has little or no correlation
3981 with actual performance.
3982
3983 ``align=on`` will activate the delay algorithm which will try to
3984 synchronise the host clock and the virtual clock. The goal is to
3985 have a guest running at the real frequency imposed by the shift
3986 option. Whenever the guest clock is behind the host clock and if
3987 ``align=on`` is specified then we print a message to the user to
3988 inform about the delay. Currently this option does not work when
3989 ``shift`` is ``auto``. Note: The sync algorithm will work for those
3990 shift values for which the guest clock runs ahead of the host clock.
3991 Typically this happens when the shift value is high (how high
3992 depends on the host machine).
3993
3994 When ``rr`` option is specified deterministic record/replay is
3995 enabled. Replay log is written into filename file in record mode and
3996 read from this file in replay mode.
3997
3998 Option rrsnapshot is used to create new vm snapshot named snapshot
3999 at the start of execution recording. In replay mode this option is
4000 used to load the initial VM state.
4001ERST
blueswir15824d652009-03-28 06:44:27 +00004002
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004003DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
Xu Wangd7933ef2015-06-11 17:32:05 +02004004 "-watchdog model\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004005 " enable virtual hardware watchdog [default=none]\n",
4006 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004007SRST
4008``-watchdog model``
4009 Create a virtual hardware watchdog device. Once enabled (by a guest
4010 action), the watchdog must be periodically polled by an agent inside
4011 the guest or else the guest will be restarted. Choose a model for
4012 which your guest has drivers.
4013
4014 The model is the model of hardware watchdog to emulate. Use
4015 ``-watchdog help`` to list available hardware models. Only one
4016 watchdog can be enabled for a guest.
4017
4018 The following models may be available:
4019
4020 ``ib700``
4021 iBASE 700 is a very simple ISA watchdog with a single timer.
4022
4023 ``i6300esb``
4024 Intel 6300ESB I/O controller hub is a much more featureful
4025 PCI-based dual-timer watchdog.
4026
4027 ``diag288``
4028 A virtual watchdog for s390x backed by the diagnose 288
4029 hypercall (currently KVM only).
4030ERST
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004031
4032DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
Markus Armbruster7ad92702017-10-02 16:03:07 +02004033 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004034 " action when watchdog fires [default=reset]\n",
4035 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004036SRST
4037``-watchdog-action action``
4038 The action controls what QEMU will do when the watchdog timer
4039 expires. The default is ``reset`` (forcefully reset the guest).
4040 Other possible actions are: ``shutdown`` (attempt to gracefully
4041 shutdown the guest), ``poweroff`` (forcefully poweroff the guest),
4042 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the
4043 guest), ``debug`` (print a debug message and continue), or ``none``
4044 (do nothing).
4045
4046 Note that the ``shutdown`` action requires that the guest responds
4047 to ACPI signals, which it may not be able to do in the sort of
4048 situations where the watchdog would have expired, and thus
4049 ``-watchdog-action shutdown`` is not recommended for production use.
4050
4051 Examples:
4052
4053 ``-watchdog i6300esb -watchdog-action pause``; \ ``-watchdog ib700``
4054
4055ERST
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004056
blueswir15824d652009-03-28 06:44:27 +00004057DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
Blue Swirlad960902010-03-29 19:23:52 +00004058 "-echr chr set terminal escape character instead of ctrl-a\n",
4059 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004060SRST
4061``-echr numeric_ascii_value``
4062 Change the escape character used for switching to the monitor when
4063 using monitor and serial sharing. The default is ``0x01`` when using
4064 the ``-nographic`` option. ``0x01`` is equal to pressing
4065 ``Control-a``. You can select a different character from the ascii
4066 control keys where 1 through 26 map to Control-a through Control-z.
4067 For instance you could use the either of the following to change the
4068 escape character to Control-t.
4069
4070 ``-echr 0x14``; \ ``-echr 20``
4071
4072ERST
blueswir15824d652009-03-28 06:44:27 +00004073
blueswir15824d652009-03-28 06:44:27 +00004074DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
Blue Swirlad960902010-03-29 19:23:52 +00004075 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004076SRST
4077``-show-cursor``
4078 Show cursor.
4079ERST
blueswir15824d652009-03-28 06:44:27 +00004080
4081DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
Blue Swirlad960902010-03-29 19:23:52 +00004082 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004083SRST
4084``-tb-size n``
4085 Set TCG translation block cache size. Deprecated, use
4086 '\ ``-accel tcg,tb-size=n``\ ' instead.
4087ERST
blueswir15824d652009-03-28 06:44:27 +00004088
4089DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
Michael Tokarev7c601802015-02-10 22:40:47 +03004090 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
4091 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
4092 "-incoming unix:socketpath\n" \
4093 " prepare for incoming migration, listen on\n" \
4094 " specified protocol and socket address\n" \
4095 "-incoming fd:fd\n" \
4096 "-incoming exec:cmdline\n" \
4097 " accept incoming migration on given file descriptor\n" \
Dr. David Alan Gilbert15970512015-05-29 19:52:52 +01004098 " or from given external command\n" \
4099 "-incoming defer\n" \
4100 " wait for the URI to be specified via migrate_incoming\n",
Blue Swirlad960902010-03-29 19:23:52 +00004101 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004102SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00004103``-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]``
4104 \
4105``-incoming rdma:host:port[,ipv4][,ipv6]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004106 Prepare for incoming migration, listen on a given tcp port.
4107
4108``-incoming unix:socketpath``
4109 Prepare for incoming migration, listen on a given unix socket.
4110
4111``-incoming fd:fd``
4112 Accept incoming migration from a given filedescriptor.
4113
4114``-incoming exec:cmdline``
4115 Accept incoming migration as an output from specified external
4116 command.
4117
4118``-incoming defer``
4119 Wait for the URI to be specified via migrate\_incoming. The monitor
4120 can be used to change settings (such as migration parameters) prior
4121 to issuing the migrate\_incoming to allow the migration to begin.
4122ERST
blueswir15824d652009-03-28 06:44:27 +00004123
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304124DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
4125 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004126SRST
4127``-only-migratable``
4128 Only allow migratable devices. Devices will not be allowed to enter
4129 an unmigratable state.
4130ERST
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304131
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004132DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
Blue Swirlad960902010-03-29 19:23:52 +00004133 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004134SRST
4135``-nodefaults``
4136 Don't create default devices. Normally, QEMU sets the default
4137 devices like serial port, parallel port, virtual console, monitor
4138 device, VGA adapter, floppy and CD-ROM drive and others. The
4139 ``-nodefaults`` option will disable all those default devices.
4140ERST
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004141
blueswir15824d652009-03-28 06:44:27 +00004142#ifndef _WIN32
4143DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
Blue Swirlad960902010-03-29 19:23:52 +00004144 "-chroot dir chroot to dir just before starting the VM\n",
4145 QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004146#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004147SRST
4148``-chroot dir``
4149 Immediately before starting guest execution, chroot to the specified
4150 directory. Especially useful in combination with -runas.
4151ERST
blueswir15824d652009-03-28 06:44:27 +00004152
4153#ifndef _WIN32
4154DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
Ian Jackson2c42f1e2017-09-15 18:10:44 +01004155 "-runas user change to user id user just before starting the VM\n" \
4156 " user can be numeric uid:gid instead\n",
Blue Swirlad960902010-03-29 19:23:52 +00004157 QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004158#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004159SRST
4160``-runas user``
4161 Immediately before starting guest execution, drop root privileges,
4162 switching to the specified user.
4163ERST
blueswir15824d652009-03-28 06:44:27 +00004164
blueswir15824d652009-03-28 06:44:27 +00004165DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
4166 "-prom-env variable=value\n"
Blue Swirlad960902010-03-29 19:23:52 +00004167 " set OpenBIOS nvram variables\n",
4168 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004169SRST
4170``-prom-env variable=value``
4171 Set OpenBIOS nvram variable to given value (PPC, SPARC only).
4172
4173 ::
4174
4175 qemu-system-sparc -prom-env 'auto-boot?=false' \
4176 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
4177
4178 ::
4179
4180 qemu-system-ppc -prom-env 'auto-boot?=false' \
4181 -prom-env 'boot-device=hd:2,\yaboot' \
4182 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
4183ERST
blueswir15824d652009-03-28 06:44:27 +00004184DEF("semihosting", 0, QEMU_OPTION_semihosting,
Michael Wallef7bbcfb2014-04-22 20:18:42 +02004185 "-semihosting semihosting mode\n",
Leon Alrae3b3c1692015-06-19 11:08:43 +01004186 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
Sandra Loosemore413a99a2019-04-03 13:53:05 -06004187 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004188SRST
4189``-semihosting``
4190 Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only).
4191
4192 Note that this allows guest direct access to the host filesystem, so
4193 should only be used with a trusted guest OS.
4194
4195 See the -semihosting-config option documentation for further
4196 information about the facilities this enables.
4197ERST
Liviu Ionescua38bb072014-12-11 12:07:48 +00004198DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
Alex Bennée4e7f9032019-05-14 15:30:14 +01004199 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \
Leon Alraea59d31a2015-06-19 14:17:45 +01004200 " semihosting configuration\n",
Leon Alrae3b3c1692015-06-19 11:08:43 +01004201QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
Sandra Loosemore413a99a2019-04-03 13:53:05 -06004202QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004203SRST
4204``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]``
4205 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II
4206 only).
4207
4208 Note that this allows guest direct access to the host filesystem, so
4209 should only be used with a trusted guest OS.
4210
4211 On Arm this implements the standard semihosting API, version 2.0.
4212
4213 On M68K this implements the "ColdFire GDB" interface used by
4214 libgloss.
4215
4216 Xtensa semihosting provides basic file IO calls, such as
4217 open/read/write/seek/select. Tensilica baremetal libc for ISS and
4218 linux platform "sim" use this interface.
4219
4220 ``target=native|gdb|auto``
4221 Defines where the semihosting calls will be addressed, to QEMU
4222 (``native``) or to GDB (``gdb``). The default is ``auto``, which
4223 means ``gdb`` during debug sessions and ``native`` otherwise.
4224
4225 ``chardev=str1``
4226 Send the output to a chardev backend output for native or auto
4227 output when not in gdb
4228
4229 ``arg=str1,arg=str2,...``
4230 Allows the user to pass input arguments, and can be used
4231 multiple times to build up a list. The old-style
4232 ``-kernel``/``-append`` method of passing a command line is
4233 still supported for backward compatibility. If both the
4234 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are
4235 specified, the former is passed to semihosting as it always
4236 takes precedence.
4237ERST
blueswir15824d652009-03-28 06:44:27 +00004238DEF("old-param", 0, QEMU_OPTION_old_param,
Blue Swirlad960902010-03-29 19:23:52 +00004239 "-old-param old param mode\n", QEMU_ARCH_ARM)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004240SRST
4241``-old-param``
4242 Old param mode (ARM only).
4243ERST
Stefan Weil95d5f082010-01-20 22:25:27 +01004244
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03004245DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01004246 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01004247 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
Eduardo Otubo2b716fa2017-03-01 23:17:29 +01004248 " Enable seccomp mode 2 system call filter (default 'off').\n" \
4249 " use 'obsolete' to allow obsolete system calls that are provided\n" \
4250 " by the kernel, but typically no longer used by modern\n" \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01004251 " C library implementations.\n" \
4252 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
4253 " its privileges by blacklisting all set*uid|gid system calls.\n" \
4254 " The value 'children' will deny set*uid|gid system calls for\n" \
Eduardo Otubo995a2262017-03-13 22:16:01 +01004255 " main QEMU process but will allow forks and execves to run unprivileged\n" \
4256 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01004257 " blacklisting *fork and execve\n" \
4258 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03004259 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004260SRST
4261``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]``
4262 Enable Seccomp mode 2 system call filter. 'on' will enable syscall
4263 filtering and 'off' will disable it. The default is 'off'.
4264
4265 ``obsolete=string``
4266 Enable Obsolete system calls
4267
4268 ``elevateprivileges=string``
4269 Disable set\*uid\|gid system calls
4270
4271 ``spawn=string``
4272 Disable \*fork and execve
4273
4274 ``resourcecontrol=string``
4275 Disable process affinity and schedular priority
4276ERST
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03004277
Gerd Hoffmann715a6642009-10-14 10:39:28 +02004278DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
Blue Swirlad960902010-03-29 19:23:52 +00004279 "-readconfig <file>\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004280SRST
4281``-readconfig file``
4282 Read device configuration from file. This approach is useful when
4283 you want to spawn QEMU process with many command line options but
4284 you don't want to exceed the command line character limit.
4285ERST
Gerd Hoffmann715a6642009-10-14 10:39:28 +02004286DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
4287 "-writeconfig <file>\n"
Blue Swirlad960902010-03-29 19:23:52 +00004288 " read/write config file\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004289SRST
4290``-writeconfig file``
4291 Write device configuration to file. The file can be either filename
4292 to save command line and device configuration into file or dash
4293 ``-``) character to print the output to stdout. This can be later
4294 used as input file for ``-readconfig`` option.
4295ERST
Thomas Huth2feac452018-08-21 12:59:56 +02004296
Eduardo Habkostf29a5612012-05-02 13:07:29 -03004297DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
4298 "-no-user-config\n"
Eduardo Habkost3478eae2017-10-04 00:00:25 -03004299 " do not load default user-provided config files at startup\n",
Eduardo Habkostf29a5612012-05-02 13:07:29 -03004300 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004301SRST
4302``-no-user-config``
4303 The ``-no-user-config`` option makes QEMU not load any of the
4304 user-provided config files on sysconfdir.
4305ERST
Thomas Huth2feac452018-08-21 12:59:56 +02004306
Prerna Saxenaab6540d2010-08-09 11:48:32 +01004307DEF("trace", HAS_ARG, QEMU_OPTION_trace,
Paolo Bonzini10578a22016-01-07 16:55:26 +03004308 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
Lluís23d15e82011-08-31 20:31:31 +02004309 " specify tracing options\n",
Prerna Saxenaab6540d2010-08-09 11:48:32 +01004310 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004311SRST
4312``-trace [[enable=]pattern][,events=file][,file=file]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004313 .. include:: ../qemu-option-trace.rst.inc
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004314
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004315ERST
Lluís Vilanova42229a72017-07-24 17:28:22 +03004316DEF("plugin", HAS_ARG, QEMU_OPTION_plugin,
4317 "-plugin [file=]<file>[,arg=<string>]\n"
4318 " load a plugin\n",
4319 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004320SRST
4321``-plugin file=file[,arg=string]``
4322 Load a plugin.
4323
4324 ``file=file``
4325 Load the given plugin from a shared library file.
4326
4327 ``arg=string``
4328 Argument string passed to the plugin. (Can be given multiple
4329 times.)
4330ERST
Stefan Weil3dbf2c72010-01-16 18:19:44 +01004331
Markus Armbruster31e70d62013-02-13 19:49:37 +01004332HXCOMM Internal use
4333DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
4334DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
Anthony Liguoric7f0f3b2012-03-28 15:42:02 +02004335
Paul Moore0f669982012-08-03 14:39:21 -04004336#ifdef __linux__
4337DEF("enable-fips", 0, QEMU_OPTION_enablefips,
4338 "-enable-fips enable FIPS 140-2 compliance\n",
4339 QEMU_ARCH_ALL)
4340#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004341SRST
4342``-enable-fips``
4343 Enable FIPS 140-2 compliance mode.
4344ERST
Paul Moore0f669982012-08-03 14:39:21 -04004345
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04004346DEF("msg", HAS_ARG, QEMU_OPTION_msg,
Mario Smarduch2880ffb2020-06-26 13:19:00 -07004347 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n"
Markus Armbrusterdeda4972019-10-10 10:15:08 +02004348 " control error message format\n"
Mario Smarduch2880ffb2020-06-26 13:19:00 -07004349 " timestamp=on enables timestamps (default: off)\n"
4350 " guest-name=on enables guest name prefix but only if\n"
4351 " -name guest option is set (default: off)\n",
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04004352 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004353SRST
Mario Smarduch2880ffb2020-06-26 13:19:00 -07004354``-msg [timestamp[=on|off]][,guest-name[=on|off]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004355 Control error message format.
4356
4357 ``timestamp=on|off``
4358 Prefix messages with a timestamp. Default is off.
Mario Smarduch2880ffb2020-06-26 13:19:00 -07004359
4360 ``guest-name=on|off``
4361 Prefix messages with guest name but only if -name guest option is set
4362 otherwise the option is ignored. Default is off.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004363ERST
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04004364
Amit Shahabfd9ce2014-06-20 18:56:08 +05304365DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
4366 "-dump-vmstate <file>\n"
4367 " Output vmstate information in JSON format to file.\n"
4368 " Use the scripts/vmstate-static-checker.py file to\n"
4369 " check for possible regressions in migration code\n"
Laurent Vivier23820532015-09-04 21:30:04 +02004370 " by comparing two such vmstate dumps.\n",
Amit Shahabfd9ce2014-06-20 18:56:08 +05304371 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004372SRST
4373``-dump-vmstate file``
4374 Dump json-encoded vmstate information for current machine type to
4375 file in file
4376ERST
Amit Shahabfd9ce2014-06-20 18:56:08 +05304377
Emilio G. Cota12df1892018-08-15 11:42:49 -04004378DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
4379 "-enable-sync-profile\n"
4380 " enable synchronization profiling\n",
4381 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004382SRST
4383``-enable-sync-profile``
4384 Enable synchronization profiling.
4385ERST
Emilio G. Cota12df1892018-08-15 11:42:49 -04004386
Paolo Bonzini43f187a2017-01-04 13:50:37 +01004387DEFHEADING()
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02004388
4389DEFHEADING(Generic object creation:)
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01004390
4391DEF("object", HAS_ARG, QEMU_OPTION_object,
4392 "-object TYPENAME[,PROP1=VALUE1,...]\n"
4393 " create a new object of type TYPENAME setting properties\n"
4394 " in the order they are specified. Note that the 'id'\n"
4395 " property must be set. These objects are placed in the\n"
4396 " '/objects' path.\n",
4397 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004398SRST
4399``-object typename[,prop1=value1,...]``
4400 Create a new object of type typename setting properties in the order
4401 they are specified. Note that the 'id' property must be set. These
4402 objects are placed in the '/objects' path.
4403
4404 ``-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``
4405 Creates a memory file backend object, which can be used to back
4406 the guest RAM with huge pages.
4407
4408 The ``id`` parameter is a unique ID that will be used to
4409 reference this memory region when configuring the ``-numa``
4410 argument.
4411
4412 The ``size`` option provides the size of the memory region, and
4413 accepts common suffixes, eg ``500M``.
4414
4415 The ``mem-path`` provides the path to either a shared memory or
4416 huge page filesystem mount.
4417
4418 The ``share`` boolean option determines whether the memory
4419 region is marked as private to QEMU, or shared. The latter
4420 allows a co-operating external process to access the QEMU memory
4421 region.
4422
4423 The ``share`` is also required for pvrdma devices due to
4424 limitations in the RDMA API provided by Linux.
4425
4426 Setting share=on might affect the ability to configure NUMA
4427 bindings for the memory backend under some circumstances, see
4428 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel
4429 source tree for additional details.
4430
4431 Setting the ``discard-data`` boolean option to on indicates that
4432 file contents can be destroyed when QEMU exits, to avoid
4433 unnecessarily flushing data to the backing file. Note that
4434 ``discard-data`` is only an optimization, and QEMU might not
4435 discard file contents if it aborts unexpectedly or is terminated
4436 using SIGKILL.
4437
4438 The ``merge`` boolean option enables memory merge, also known as
4439 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider
4440 the pages for memory deduplication.
4441
4442 Setting the ``dump`` boolean option to off excludes the memory
4443 from core dumps. This feature is also known as MADV\_DONTDUMP.
4444
4445 The ``prealloc`` boolean option enables memory preallocation.
4446
4447 The ``host-nodes`` option binds the memory range to a list of
4448 NUMA host nodes.
4449
4450 The ``policy`` option sets the NUMA policy to one of the
4451 following values:
4452
4453 ``default``
4454 default host policy
4455
4456 ``preferred``
4457 prefer the given host node list for allocation
4458
4459 ``bind``
4460 restrict memory allocation to the given host node list
4461
4462 ``interleave``
4463 interleave memory allocations across the given host node
4464 list
4465
4466 The ``align`` option specifies the base address alignment when
4467 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg
4468 ``2M``. Some backend store specified by ``mem-path`` requires an
4469 alignment different than the default one used by QEMU, eg the
4470 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4471 such cases, users can specify the required alignment via this
4472 option.
4473
4474 The ``pmem`` option specifies whether the backing file specified
4475 by ``mem-path`` is in host persistent memory that can be
4476 accessed using the SNIA NVM programming model (e.g. Intel
4477 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary
4478 operations to guarantee the persistence of its own writes to
4479 ``mem-path`` (e.g. in vNVDIMM label emulation and live
4480 migration). Also, we will map the backend-file with MAP\_SYNC
4481 flag, which ensures the file metadata is in sync for
4482 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC
4483 requires support from both the host kernel (since Linux kernel
4484 4.15) and the filesystem of ``mem-path`` mounted with DAX
4485 option.
4486
4487 ``-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``
4488 Creates a memory backend object, which can be used to back the
4489 guest RAM. Memory backend objects offer more control than the
4490 ``-m`` option that is traditionally used to define guest RAM.
4491 Please refer to ``memory-backend-file`` for a description of the
4492 options.
4493
4494 ``-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``
4495 Creates an anonymous memory file backend object, which allows
4496 QEMU to share the memory with an external process (e.g. when
4497 using vhost-user). The memory is allocated with memfd and
4498 optional sealing. (Linux only)
4499
4500 The ``seal`` option creates a sealed-file, that will block
4501 further resizing the memory ('on' by default).
4502
4503 The ``hugetlb`` option specify the file to be created resides in
4504 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction
4505 with the ``hugetlb`` option, the ``hugetlbsize`` option specify
4506 the hugetlb page size on systems that support multiple hugetlb
4507 page sizes (it must be a power of 2 value supported by the
4508 system).
4509
4510 In some versions of Linux, the ``hugetlb`` option is
4511 incompatible with the ``seal`` option (requires at least Linux
4512 4.16).
4513
4514 Please refer to ``memory-backend-file`` for a description of the
4515 other options.
4516
4517 The ``share`` boolean option is on by default with memfd.
4518
4519 ``-object rng-builtin,id=id``
4520 Creates a random number generator backend which obtains entropy
4521 from QEMU builtin functions. The ``id`` parameter is a unique ID
4522 that will be used to reference this entropy backend from the
4523 ``virtio-rng`` device. By default, the ``virtio-rng`` device
4524 uses this RNG backend.
4525
4526 ``-object rng-random,id=id,filename=/dev/random``
4527 Creates a random number generator backend which obtains entropy
4528 from a device on the host. The ``id`` parameter is a unique ID
4529 that will be used to reference this entropy backend from the
4530 ``virtio-rng`` device. The ``filename`` parameter specifies
4531 which file to obtain entropy from and if omitted defaults to
4532 ``/dev/urandom``.
4533
4534 ``-object rng-egd,id=id,chardev=chardevid``
4535 Creates a random number generator backend which obtains entropy
4536 from an external daemon running on the host. The ``id``
4537 parameter is a unique ID that will be used to reference this
4538 entropy backend from the ``virtio-rng`` device. The ``chardev``
4539 parameter is the unique ID of a character device backend that
4540 provides the connection to the RNG daemon.
4541
4542 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off``
4543 Creates a TLS anonymous credentials object, which can be used to
4544 provide TLS support on network backends. The ``id`` parameter is
4545 a unique ID which network backends will use to access the
4546 credentials. The ``endpoint`` is either ``server`` or ``client``
4547 depending on whether the QEMU network backend that uses the
4548 credentials will be acting as a client or as a server. If
4549 ``verify-peer`` is enabled (the default) then once the handshake
4550 is completed, the peer credentials will be verified, though this
4551 is a no-op for anonymous credentials.
4552
4553 The dir parameter tells QEMU where to find the credential files.
4554 For server endpoints, this directory may contain a file
4555 dh-params.pem providing diffie-hellman parameters to use for the
4556 TLS server. If the file is missing, QEMU will generate a set of
4557 DH parameters at startup. This is a computationally expensive
4558 operation that consumes random pool entropy, so it is
4559 recommended that a persistent set of parameters be generated
4560 upfront and saved.
4561
4562 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]``
4563 Creates a TLS Pre-Shared Keys (PSK) credentials object, which
4564 can be used to provide TLS support on network backends. The
4565 ``id`` parameter is a unique ID which network backends will use
4566 to access the credentials. The ``endpoint`` is either ``server``
4567 or ``client`` depending on whether the QEMU network backend that
4568 uses the credentials will be acting as a client or as a server.
4569 For clients only, ``username`` is the username which will be
4570 sent to the server. If omitted it defaults to "qemu".
4571
4572 The dir parameter tells QEMU where to find the keys file. It is
4573 called "dir/keys.psk" and contains "username:key" pairs. This
4574 file can most easily be created using the GnuTLS ``psktool``
4575 program.
4576
4577 For server endpoints, dir may also contain a file dh-params.pem
4578 providing diffie-hellman parameters to use for the TLS server.
4579 If the file is missing, QEMU will generate a set of DH
4580 parameters at startup. This is a computationally expensive
4581 operation that consumes random pool entropy, so it is
4582 recommended that a persistent set of parameters be generated up
4583 front and saved.
4584
4585 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id``
4586 Creates a TLS anonymous credentials object, which can be used to
4587 provide TLS support on network backends. The ``id`` parameter is
4588 a unique ID which network backends will use to access the
4589 credentials. The ``endpoint`` is either ``server`` or ``client``
4590 depending on whether the QEMU network backend that uses the
4591 credentials will be acting as a client or as a server. If
4592 ``verify-peer`` is enabled (the default) then once the handshake
4593 is completed, the peer credentials will be verified. With x509
4594 certificates, this implies that the clients must be provided
4595 with valid client certificates too.
4596
4597 The dir parameter tells QEMU where to find the credential files.
4598 For server endpoints, this directory may contain a file
4599 dh-params.pem providing diffie-hellman parameters to use for the
4600 TLS server. If the file is missing, QEMU will generate a set of
4601 DH parameters at startup. This is a computationally expensive
4602 operation that consumes random pool entropy, so it is
4603 recommended that a persistent set of parameters be generated
4604 upfront and saved.
4605
4606 For x509 certificate credentials the directory will contain
4607 further files providing the x509 certificates. The certificates
4608 must be stored in PEM format, in filenames ca-cert.pem,
4609 ca-crl.pem (optional), server-cert.pem (only servers),
4610 server-key.pem (only servers), client-cert.pem (only clients),
4611 and client-key.pem (only clients).
4612
4613 For the server-key.pem and client-key.pem files which contain
4614 sensitive private keys, it is possible to use an encrypted
4615 version by providing the passwordid parameter. This provides the
4616 ID of a previously created ``secret`` object containing the
4617 password for decryption.
4618
4619 The priority parameter allows to override the global default
4620 priority used by gnutls. This can be useful if the system
4621 administrator needs to use a weaker set of crypto priorities for
4622 QEMU without potentially forcing the weakness onto all
4623 applications. Or conversely if one wants wants a stronger
4624 default for QEMU than for all other applications, they can do
4625 this through this parameter. Its format is a gnutls priority
4626 string as described at
4627 https://gnutls.org/manual/html_node/Priority-Strings.html.
4628
Philippe Mathieu-Daudé993aec22018-10-11 20:21:11 +02004629 ``-object tls-cipher-suites,id=id,priority=priority``
4630 Creates a TLS cipher suites object, which can be used to control
4631 the TLS cipher/protocol algorithms that applications are permitted
4632 to use.
4633
4634 The ``id`` parameter is a unique ID which frontends will use to
4635 access the ordered list of permitted TLS cipher suites from the
4636 host.
4637
4638 The ``priority`` parameter allows to override the global default
4639 priority used by gnutls. This can be useful if the system
4640 administrator needs to use a weaker set of crypto priorities for
4641 QEMU without potentially forcing the weakness onto all
4642 applications. Or conversely if one wants wants a stronger
4643 default for QEMU than for all other applications, they can do
4644 this through this parameter. Its format is a gnutls priority
4645 string as described at
4646 https://gnutls.org/manual/html_node/Priority-Strings.html.
4647
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02004648 An example of use of this object is to control UEFI HTTPS Boot.
4649 The tls-cipher-suites object exposes the ordered list of permitted
4650 TLS cipher suites from the host side to the guest firmware, via
4651 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER
4652 objects. The firmware uses the IANA_TLS_CIPHER array for configuring
4653 guest-side TLS.
4654
4655 In the following example, the priority at which the host-side policy
4656 is retrieved is given by the ``priority`` property.
4657 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to
4658 refer to /etc/crypto-policies/back-ends/gnutls.config.
4659
4660 .. parsed-literal::
4661
Laszlo Ersek353a06b2020-09-08 19:21:11 +02004662 # |qemu_system| \\
4663 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02004664 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0
4665
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004666 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]``
4667 Interval t can't be 0, this filter batches the packet delivery:
4668 all packets arriving in a given interval on netdev netdevid are
4669 delayed until the end of the interval. Interval is in
4670 microseconds. ``status`` is optional that indicate whether the
4671 netfilter is on (enabled) or off (disabled), the default status
4672 for netfilter will be 'on'.
4673
4674 queue all\|rx\|tx is an option that can be applied to any
4675 netfilter.
4676
4677 ``all``: the filter is attached both to the receive and the
4678 transmit queue of the netdev (default).
4679
4680 ``rx``: the filter is attached to the receive queue of the
4681 netdev, where it will receive packets sent to the netdev.
4682
4683 ``tx``: the filter is attached to the transmit queue of the
4684 netdev, where it will receive packets sent by the netdev.
4685
4686 position head\|tail\|id=<id> is an option to specify where the
4687 filter should be inserted in the filter list. It can be applied
4688 to any netfilter.
4689
4690 ``head``: the filter is inserted at the head of the filter list,
4691 before any existing filters.
4692
4693 ``tail``: the filter is inserted at the tail of the filter list,
4694 behind any existing filters (default).
4695
4696 ``id=<id>``: the filter is inserted before or behind the filter
4697 specified by <id>, see the insert option below.
4698
4699 insert behind\|before is an option to specify where to insert
4700 the new filter relative to the one specified with
4701 position=id=<id>. It can be applied to any netfilter.
4702
4703 ``before``: insert before the specified filter.
4704
4705 ``behind``: insert behind the specified filter (default).
4706
4707 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
4708 filter-mirror on netdev netdevid,mirror net packet to
4709 chardevchardevid, if it has the vnet\_hdr\_support flag,
4710 filter-mirror will mirror packet with vnet\_hdr\_len.
4711
4712 ``-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]``
4713 filter-redirector on netdev netdevid,redirect filter's net
4714 packet to chardev chardevid,and redirect indev's packet to
4715 filter.if it has the vnet\_hdr\_support flag, filter-redirector
4716 will redirect packet with vnet\_hdr\_len. Create a
4717 filter-redirector we need to differ outdev id from indev id, id
4718 can not be the same. we can just use indev or outdev, but at
4719 least one of indev or outdev need to be specified.
4720
4721 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
4722 Filter-rewriter is a part of COLO project.It will rewrite tcp
4723 packet to secondary from primary to keep secondary tcp
4724 connection,and rewrite tcp packet to primary from secondary make
4725 tcp packet can be handled by client.if it has the
4726 vnet\_hdr\_support flag, we can parse packet with vnet header.
4727
4728 usage: colo secondary: -object
4729 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object
4730 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object
4731 filter-rewriter,id=rew0,netdev=hn0,queue=all
4732
4733 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]``
4734 Dump the network traffic on netdev dev to the file specified by
4735 filename. At most len bytes (64k by default) per packet are
4736 stored. The file format is libpcap, so it can be analyzed with
4737 tools such as tcpdump or Wireshark.
4738
Zhang Chena2e5cb72020-06-24 09:20:41 +08004739 ``-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 +08004740 Colo-compare gets packet from primary\_in chardevid and
4741 secondary\_in, then compare whether the payload of primary packet
4742 and secondary packet are the same. If same, it will output
4743 primary packet to out\_dev, else it will notify COLO-framework to do
4744 checkpoint and send primary packet to out\_dev. In order to
4745 improve efficiency, we need to put the task of comparison in
4746 another iothread. If it has the vnet\_hdr\_support flag,
4747 colo compare will send/recv packet with vnet\_hdr\_len.
4748 The compare\_timeout=@var{ms} determines the maximum time of the
4749 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms}
4750 is to set the period of scanning expired primary node network packets.
4751 The max\_queue\_size=@var{size} is to set the max compare queue
4752 size depend on user environment.
4753 If user want to use Xen COLO, need to add the notify\_dev to
Zhang Chen9cc43c92020-03-18 16:23:19 +08004754 notify Xen colo-frame to do checkpoint.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004755
Zhang Chen2b28a7e2020-06-24 09:20:42 +08004756 COLO-compare must be used with the help of filter-mirror,
4757 filter-redirector and filter-rewriter.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004758
4759 ::
4760
4761 KVM COLO
4762
4763 primary:
4764 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4765 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4766 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4767 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4768 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4769 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4770 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4771 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4772 -object iothread,id=iothread1
4773 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4774 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4775 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4776 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1
4777
4778 secondary:
4779 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4780 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4781 -chardev socket,id=red0,host=3.3.3.3,port=9003
4782 -chardev socket,id=red1,host=3.3.3.3,port=9004
4783 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4784 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4785
4786
4787 Xen COLO
4788
4789 primary:
4790 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4791 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4792 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4793 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4794 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4795 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4796 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4797 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4798 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait
4799 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4800 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4801 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4802 -object iothread,id=iothread1
4803 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1
4804
4805 secondary:
4806 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4807 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4808 -chardev socket,id=red0,host=3.3.3.3,port=9003
4809 -chardev socket,id=red1,host=3.3.3.3,port=9004
4810 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4811 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4812
4813 If you want to know the detail of above command line, you can
4814 read the colo-compare git log.
4815
4816 ``-object cryptodev-backend-builtin,id=id[,queues=queues]``
4817 Creates a cryptodev backend which executes crypto opreation from
4818 the QEMU cipher APIS. The id parameter is a unique ID that will
4819 be used to reference this cryptodev backend from the
4820 ``virtio-crypto`` device. The queues parameter is optional,
4821 which specify the queue number of cryptodev backend, the default
4822 of queues is 1.
4823
Peter Maydell09ce5f22020-02-28 15:36:13 +00004824 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004825
Laszlo Ersek353a06b2020-09-08 19:21:11 +02004826 # |qemu_system| \\
4827 [...] \\
4828 -object cryptodev-backend-builtin,id=cryptodev0 \\
4829 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004830 [...]
4831
4832 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]``
4833 Creates a vhost-user cryptodev backend, backed by a chardev
4834 chardevid. The id parameter is a unique ID that will be used to
4835 reference this cryptodev backend from the ``virtio-crypto``
4836 device. The chardev should be a unix domain socket backed one.
4837 The vhost-user uses a specifically defined protocol to pass
4838 vhost ioctl replacement messages to an application on the other
4839 end of the socket. The queues parameter is optional, which
4840 specify the queue number of cryptodev backend for multiqueue
4841 vhost-user, the default of queues is 1.
4842
Peter Maydell09ce5f22020-02-28 15:36:13 +00004843 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004844
Laszlo Ersek353a06b2020-09-08 19:21:11 +02004845 # |qemu_system| \\
4846 [...] \\
4847 -chardev socket,id=chardev0,path=/path/to/socket \\
4848 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\
4849 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004850 [...]
4851
4852 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004853 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004854 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]``
4855 Defines a secret to store a password, encryption key, or some
4856 other sensitive data. The sensitive data can either be passed
4857 directly via the data parameter, or indirectly via the file
4858 parameter. Using the data parameter is insecure unless the
4859 sensitive data is encrypted.
4860
4861 The sensitive data can be provided in raw format (the default),
4862 or base64. When encoded as JSON, the raw format only supports
4863 valid UTF-8 characters, so base64 is recommended for sending
4864 binary data. QEMU will convert from which ever format is
4865 provided to the format it needs internally. eg, an RBD password
4866 can be provided in raw format, even though it will be base64
4867 encoded when passed onto the RBD sever.
4868
4869 For added protection, it is possible to encrypt the data
4870 associated with a secret using the AES-256-CBC cipher. Use of
4871 encryption is indicated by providing the keyid and iv
4872 parameters. The keyid parameter provides the ID of a previously
4873 defined secret that contains the AES-256 decryption key. This
4874 key should be 32-bytes long and be base64 encoded. The iv
4875 parameter provides the random initialization vector used for
4876 encryption of this particular secret and should be a base64
4877 encrypted string of the 16-byte IV.
4878
4879 The simplest (insecure) usage is to provide the secret inline
4880
Peter Maydell09ce5f22020-02-28 15:36:13 +00004881 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004882
4883 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw
4884
4885 The simplest secure usage is to provide the secret via a file
4886
4887 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object
4888 secret,id=sec0,file=mypasswd.txt,format=raw
4889
4890 For greater security, AES-256-CBC should be used. To illustrate
4891 usage, consider the openssl command line tool which can encrypt
4892 the data. Note that when encrypting, the plaintext must be
4893 padded to the cipher block size (32 bytes) using the standard
4894 PKCS#5/6 compatible padding algorithm.
4895
4896 First a master key needs to be created in base64 encoding:
4897
4898 ::
4899
4900 # openssl rand -base64 32 > key.b64
4901 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
4902
4903 Each secret to be encrypted needs to have a random
4904 initialization vector generated. These do not need to be kept
4905 secret
4906
4907 ::
4908
4909 # openssl rand -base64 16 > iv.b64
4910 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
4911
4912 The secret to be defined can now be encrypted, in this case
4913 we're telling openssl to base64 encode the result, but it could
4914 be left as raw bytes if desired.
4915
4916 ::
4917
4918 # SECRET=$(printf "letmein" |
4919 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4920
4921 When launching QEMU, create a master secret pointing to
4922 ``key.b64`` and specify that to be used to decrypt the user
4923 password. Pass the contents of ``iv.b64`` to the second secret
4924
Peter Maydell09ce5f22020-02-28 15:36:13 +00004925 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004926
Laszlo Ersek353a06b2020-09-08 19:21:11 +02004927 # |qemu_system| \\
4928 -object secret,id=secmaster0,format=base64,file=key.b64 \\
4929 -object secret,id=sec0,keyid=secmaster0,format=base64,\\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004930 data=$SECRET,iv=$(<iv.b64)
4931
4932 ``-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]``
4933 Create a Secure Encrypted Virtualization (SEV) guest object,
4934 which can be used to provide the guest memory encryption support
4935 on AMD processors.
4936
4937 When memory encryption is enabled, one of the physical address
4938 bit (aka the C-bit) is utilized to mark if a memory page is
4939 protected. The ``cbitpos`` is used to provide the C-bit
4940 position. The C-bit position is Host family dependent hence user
4941 must provide this value. On EPYC, the value should be 47.
4942
4943 When memory encryption is enabled, we loose certain bits in
4944 physical address space. The ``reduced-phys-bits`` is used to
4945 provide the number of bits we loose in physical address space.
4946 Similar to C-bit, the value is Host family dependent. On EPYC,
4947 the value should be 5.
4948
4949 The ``sev-device`` provides the device file to use for
4950 communicating with the SEV firmware running inside AMD Secure
4951 Processor. The default device is '/dev/sev'. If hardware
4952 supports memory encryption then /dev/sev devices are created by
4953 CCP driver.
4954
4955 The ``policy`` provides the guest policy to be enforced by the
4956 SEV firmware and restrict what configuration and operational
4957 commands can be performed on this guest by the hypervisor. The
4958 policy should be provided by the guest owner and is bound to the
4959 guest and cannot be changed throughout the lifetime of the
4960 guest. The default is 0.
4961
4962 If guest ``policy`` allows sharing the key with another SEV
4963 guest then ``handle`` can be use to provide handle of the guest
4964 from which to share the key.
4965
4966 The ``dh-cert-file`` and ``session-file`` provides the guest
4967 owner's Public Diffie-Hillman key defined in SEV spec. The PDH
4968 and session parameters are used for establishing a cryptographic
4969 session with the guest owner to negotiate keys used for
4970 attestation. The file must be encoded in base64.
4971
4972 e.g to launch a SEV guest
4973
Peter Maydell09ce5f22020-02-28 15:36:13 +00004974 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004975
Laszlo Ersek353a06b2020-09-08 19:21:11 +02004976 # |qemu_system_x86| \\
4977 ...... \\
4978 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \\
4979 -machine ...,memory-encryption=sev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004980 .....
4981
4982 ``-object authz-simple,id=id,identity=string``
4983 Create an authorization object that will control access to
4984 network services.
4985
4986 The ``identity`` parameter is identifies the user and its format
4987 depends on the network service that authorization object is
4988 associated with. For authorizing based on TLS x509 certificates,
4989 the identity must be the x509 distinguished name. Note that care
4990 must be taken to escape any commas in the distinguished name.
4991
4992 An example authorization object to validate a x509 distinguished
4993 name would look like:
4994
Peter Maydell09ce5f22020-02-28 15:36:13 +00004995 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004996
Laszlo Ersek353a06b2020-09-08 19:21:11 +02004997 # |qemu_system| \\
4998 ... \\
4999 -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 +00005000 ...
5001
5002 Note the use of quotes due to the x509 distinguished name
5003 containing whitespace, and escaping of ','.
5004
5005 ``-object authz-listfile,id=id,filename=path,refresh=yes|no``
5006 Create an authorization object that will control access to
5007 network services.
5008
5009 The ``filename`` parameter is the fully qualified path to a file
5010 containing the access control list rules in JSON format.
5011
5012 An example set of rules that match against SASL usernames might
5013 look like:
5014
5015 ::
5016
5017 {
5018 "rules": [
5019 { "match": "fred", "policy": "allow", "format": "exact" },
5020 { "match": "bob", "policy": "allow", "format": "exact" },
5021 { "match": "danb", "policy": "deny", "format": "glob" },
5022 { "match": "dan*", "policy": "allow", "format": "exact" },
5023 ],
5024 "policy": "deny"
5025 }
5026
5027 When checking access the object will iterate over all the rules
5028 and the first rule to match will have its ``policy`` value
5029 returned as the result. If no rules match, then the default
5030 ``policy`` value is returned.
5031
5032 The rules can either be an exact string match, or they can use
5033 the simple UNIX glob pattern matching to allow wildcards to be
5034 used.
5035
5036 If ``refresh`` is set to true the file will be monitored and
5037 automatically reloaded whenever its content changes.
5038
5039 As with the ``authz-simple`` object, the format of the identity
5040 strings being matched depends on the network service, but is
5041 usually a TLS x509 distinguished name, or a SASL username.
5042
5043 An example authorization object to validate a SASL username
5044 would look like:
5045
Peter Maydell09ce5f22020-02-28 15:36:13 +00005046 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005047
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005048 # |qemu_system| \\
5049 ... \\
5050 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005051 ...
5052
5053 ``-object authz-pam,id=id,service=string``
5054 Create an authorization object that will control access to
5055 network services.
5056
5057 The ``service`` parameter provides the name of a PAM service to
5058 use for authorization. It requires that a file
5059 ``/etc/pam.d/service`` exist to provide the configuration for
5060 the ``account`` subsystem.
5061
5062 An example authorization object to validate a TLS x509
5063 distinguished name would look like:
5064
Peter Maydell09ce5f22020-02-28 15:36:13 +00005065 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005066
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005067 # |qemu_system| \\
5068 ... \\
5069 -object authz-pam,id=auth0,service=qemu-vnc \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005070 ...
5071
5072 There would then be a corresponding config file for PAM at
5073 ``/etc/pam.d/qemu-vnc`` that contains:
5074
5075 ::
5076
5077 account requisite pam_listfile.so item=user sense=allow \
5078 file=/etc/qemu/vnc.allow
5079
5080 Finally the ``/etc/qemu/vnc.allow`` file would contain the list
5081 of x509 distingished names that are permitted access
5082
5083 ::
5084
5085 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB
5086
5087 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink``
5088 Creates a dedicated event loop thread that devices can be
5089 assigned to. This is known as an IOThread. By default device
5090 emulation happens in vCPU threads or the main event loop thread.
5091 This can become a scalability bottleneck. IOThreads allow device
5092 emulation and I/O to run on other host CPUs.
5093
5094 The ``id`` parameter is a unique ID that will be used to
5095 reference this IOThread from ``-device ...,iothread=id``.
5096 Multiple devices can be assigned to an IOThread. Note that not
5097 all devices support an ``iothread`` parameter.
5098
5099 The ``query-iothreads`` QMP command lists IOThreads and reports
5100 their thread IDs so that the user can configure host CPU
5101 pinning/affinity.
5102
5103 IOThreads use an adaptive polling algorithm to reduce event loop
5104 latency. Instead of entering a blocking system call to monitor
5105 file descriptors and then pay the cost of being woken up when an
5106 event occurs, the polling algorithm spins waiting for events for
5107 a short time. The algorithm's default parameters are suitable
5108 for many cases but can be adjusted based on knowledge of the
5109 workload and/or host device latency.
5110
5111 The ``poll-max-ns`` parameter is the maximum number of
5112 nanoseconds to busy wait for events. Polling can be disabled by
5113 setting this value to 0.
5114
5115 The ``poll-grow`` parameter is the multiplier used to increase
5116 the polling time when the algorithm detects it is missing events
5117 due to not polling long enough.
5118
5119 The ``poll-shrink`` parameter is the divisor used to decrease
5120 the polling time when the algorithm detects it is spending too
5121 long polling without encountering events.
5122
5123 The polling parameters can be modified at run-time using the
5124 ``qom-set`` command (where ``iothread1`` is the IOThread's
5125 ``id``):
5126
5127 ::
5128
5129 (qemu) qom-set /objects/iothread1 poll-max-ns 100000
5130ERST
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01005131
5132
Stefan Weil3dbf2c72010-01-16 18:19:44 +01005133HXCOMM This is the last statement. Insert new options before this line!