Update version for v2.12.0-rc4 release
[qemu.git] / qemu-options.hx
blobca4e412f2f89d9cb7cc202449bc211313b209e4b
1 HXCOMM Use DEFHEADING() to define headings in both help text and texi
2 HXCOMM Text between STEXI and ETEXI are copied to texi version and
3 HXCOMM discarded from C version
4 HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to
5 HXCOMM construct option structures, enums and help message for specified
6 HXCOMM architectures.
7 HXCOMM HXCOMM can be used for comments, discarded from both texi and C
9 DEFHEADING(Standard options:)
10 STEXI
11 @table @option
12 ETEXI
14 DEF("help", 0, QEMU_OPTION_h,
15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL)
16 STEXI
17 @item -h
18 @findex -h
19 Display help and exit
20 ETEXI
22 DEF("version", 0, QEMU_OPTION_version,
23 "-version display version information and exit\n", QEMU_ARCH_ALL)
24 STEXI
25 @item -version
26 @findex -version
27 Display version information and exit
28 ETEXI
30 DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
31 "-machine [type=]name[,prop[=value][,...]]\n"
32 " selects emulated machine ('-machine help' for list)\n"
33 " property accel=accel1[:accel2[:...]] selects accelerator\n"
34 " supported accelerators are kvm, xen, hax, hvf, whpx or tcg (default: tcg)\n"
35 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n"
36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
37 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n"
38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
39 " mem-merge=on|off controls memory merge support (default: on)\n"
40 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
44 " nvdimm=on|off controls NVDIMM support (default=off)\n"
45 " enforce-config-section=on|off enforce configuration section migration (default=off)\n"
46 " s390-squash-mcss=on|off (deprecated) controls support for squashing into default css (default=off)\n"
47 " memory-encryption=@var{} memory encryption object to use (default=none)\n",
48 QEMU_ARCH_ALL)
49 STEXI
50 @item -machine [type=]@var{name}[,prop=@var{value}[,...]]
51 @findex -machine
52 Select the emulated machine by @var{name}. Use @code{-machine help} to list
53 available machines.
55 For architectures which aim to support live migration compatibility
56 across releases, each release will introduce a new versioned machine
57 type. For example, the 2.8.0 release introduced machine types
58 ``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures.
60 To allow live migration of guests from QEMU version 2.8.0, to QEMU
61 version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8''
62 and ``pc-q35-2.8'' machines too. To allow users live migrating VMs
63 to skip multiple intermediate releases when upgrading, new releases
64 of QEMU will support machine types from many previous versions.
66 Supported machine properties are:
67 @table @option
68 @item accel=@var{accels1}[:@var{accels2}[:...]]
69 This is used to enable an accelerator. Depending on the target architecture,
70 kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
71 more than one accelerator specified, the next one is used if the previous one
72 fails to initialize.
73 @item kernel_irqchip=on|off
74 Controls in-kernel irqchip support for the chosen accelerator when available.
75 @item gfx_passthru=on|off
76 Enables IGD GFX passthrough support for the chosen machine when available.
77 @item vmport=on|off|auto
78 Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
79 value based on accel. For accel=xen the default is off otherwise the default
80 is on.
81 @item kvm_shadow_mem=size
82 Defines the size of the KVM shadow MMU.
83 @item dump-guest-core=on|off
84 Include guest memory in a core dump. The default is on.
85 @item mem-merge=on|off
86 Enables or disables memory merge support. This feature, when supported by
87 the host, de-duplicates identical memory pages among VMs instances
88 (enabled by default).
89 @item aes-key-wrap=on|off
90 Enables or disables AES key wrapping support on s390-ccw hosts. This feature
91 controls whether AES wrapping keys will be created to allow
92 execution of AES cryptographic functions. The default is on.
93 @item dea-key-wrap=on|off
94 Enables or disables DEA key wrapping support on s390-ccw hosts. This feature
95 controls whether DEA wrapping keys will be created to allow
96 execution of DEA cryptographic functions. The default is on.
97 @item nvdimm=on|off
98 Enables or disables NVDIMM support. The default is off.
99 @item s390-squash-mcss=on|off
100 Enables or disables squashing subchannels into the default css.
101 The default is off.
102 NOTE: This property is deprecated and will be removed in future releases.
103 The ``s390-squash-mcss=on`` property has been obsoleted by allowing the
104 cssid to be chosen freely. Instead of squashing subchannels into the
105 default channel subsystem image for guests that do not support multiple
106 channel subsystems, all devices can be put into the default channel
107 subsystem image.
108 @item enforce-config-section=on|off
109 If @option{enforce-config-section} is set to @var{on}, force migration
110 code to send configuration section even if the machine-type sets the
111 @option{migration.send-configuration} property to @var{off}.
112 NOTE: this parameter is deprecated. Please use @option{-global}
113 @option{migration.send-configuration}=@var{on|off} instead.
114 @item memory-encryption=@var{}
115 Memory encryption object to use. The default is none.
116 @end table
117 ETEXI
119 HXCOMM Deprecated by -machine
120 DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
122 DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
123 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
124 STEXI
125 @item -cpu @var{model}
126 @findex -cpu
127 Select CPU model (@code{-cpu help} for list and additional feature selection)
128 ETEXI
130 DEF("accel", HAS_ARG, QEMU_OPTION_accel,
131 "-accel [accel=]accelerator[,thread=single|multi]\n"
132 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n"
133 " thread=single|multi (enable multi-threaded TCG)", QEMU_ARCH_ALL)
134 STEXI
135 @item -accel @var{name}[,prop=@var{value}[,...]]
136 @findex -accel
137 This is used to enable an accelerator. Depending on the target architecture,
138 kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
139 more than one accelerator specified, the next one is used if the previous one
140 fails to initialize.
141 @table @option
142 @item thread=single|multi
143 Controls number of TCG threads. When the TCG is multi-threaded there will be one
144 thread per vCPU therefor taking advantage of additional host cores. The default
145 is to enable multi-threading where both the back-end and front-ends support it and
146 no incompatible TCG features have been enabled (e.g. icount/replay).
147 @end table
148 ETEXI
150 DEF("smp", HAS_ARG, QEMU_OPTION_smp,
151 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
152 " set the number of CPUs to 'n' [default=1]\n"
153 " maxcpus= maximum number of total cpus, including\n"
154 " offline CPUs for hotplug, etc\n"
155 " cores= number of CPU cores on one socket\n"
156 " threads= number of threads on one CPU core\n"
157 " sockets= number of discrete sockets in the system\n",
158 QEMU_ARCH_ALL)
159 STEXI
160 @item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
161 @findex -smp
162 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
163 CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
164 to 4.
165 For the PC target, the number of @var{cores} per socket, the number
166 of @var{threads} per cores and the total number of @var{sockets} can be
167 specified. Missing values will be computed. If any on the three values is
168 given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
169 specifies the maximum number of hotpluggable CPUs.
170 ETEXI
172 DEF("numa", HAS_ARG, QEMU_OPTION_numa,
173 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
174 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
175 "-numa dist,src=source,dst=destination,val=distance\n"
176 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n",
177 QEMU_ARCH_ALL)
178 STEXI
179 @item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
180 @itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
181 @itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance}
182 @itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}]
183 @findex -numa
184 Define a NUMA node and assign RAM and VCPUs to it.
185 Set the NUMA distance from a source node to a destination node.
187 Legacy VCPU assignment uses @samp{cpus} option where
188 @var{firstcpu} and @var{lastcpu} are CPU indexes. Each
189 @samp{cpus} option represent a contiguous range of CPU indexes
190 (or a single VCPU if @var{lastcpu} is omitted). A non-contiguous
191 set of VCPUs can be represented by providing multiple @samp{cpus}
192 options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically
193 split between them.
195 For example, the following option assigns VCPUs 0, 1, 2 and 5 to
196 a NUMA node:
197 @example
198 -numa node,cpus=0-2,cpus=5
199 @end example
201 @samp{cpu} option is a new alternative to @samp{cpus} option
202 which uses @samp{socket-id|core-id|thread-id} properties to assign
203 CPU objects to a @var{node} using topology layout properties of CPU.
204 The set of properties is machine specific, and depends on used
205 machine type/@samp{smp} options. It could be queried with
206 @samp{hotpluggable-cpus} monitor command.
207 @samp{node-id} property specifies @var{node} to which CPU object
208 will be assigned, it's required for @var{node} to be declared
209 with @samp{node} option before it's used with @samp{cpu} option.
211 For example:
212 @example
213 -M pc \
214 -smp 1,sockets=2,maxcpus=2 \
215 -numa node,nodeid=0 -numa node,nodeid=1 \
216 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
217 @end example
219 @samp{mem} assigns a given RAM amount to a node. @samp{memdev}
220 assigns RAM from a given memory backend device to a node. If
221 @samp{mem} and @samp{memdev} are omitted in all nodes, RAM is
222 split equally between them.
224 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
225 if one node uses @samp{memdev}, all of them have to use it.
227 @var{source} and @var{destination} are NUMA node IDs.
228 @var{distance} is the NUMA distance from @var{source} to @var{destination}.
229 The distance from a node to itself is always 10. If any pair of nodes is
230 given a distance, then all pairs must be given distances. Although, when
231 distances are only given in one direction for each pair of nodes, then
232 the distances in the opposite directions are assumed to be the same. If,
233 however, an asymmetrical pair of distances is given for even one node
234 pair, then all node pairs must be provided distance values for both
235 directions, even when they are symmetrical. When a node is unreachable
236 from another node, set the pair's distance to 255.
238 Note that the -@option{numa} option doesn't allocate any of the
239 specified resources, it just assigns existing resources to NUMA
240 nodes. This means that one still has to use the @option{-m},
241 @option{-smp} options to allocate RAM and VCPUs respectively.
243 ETEXI
245 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
246 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
247 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
248 STEXI
249 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
250 @findex -add-fd
252 Add a file descriptor to an fd set. Valid options are:
254 @table @option
255 @item fd=@var{fd}
256 This option defines the file descriptor of which a duplicate is added to fd set.
257 The file descriptor cannot be stdin, stdout, or stderr.
258 @item set=@var{set}
259 This option defines the ID of the fd set to add the file descriptor to.
260 @item opaque=@var{opaque}
261 This option defines a free-form string that can be used to describe @var{fd}.
262 @end table
264 You can open an image using pre-opened file descriptors from an fd set:
265 @example
266 qemu-system-i386
267 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
268 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
269 -drive file=/dev/fdset/2,index=0,media=disk
270 @end example
271 ETEXI
273 DEF("set", HAS_ARG, QEMU_OPTION_set,
274 "-set group.id.arg=value\n"
275 " set <arg> parameter for item <id> of type <group>\n"
276 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
277 STEXI
278 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
279 @findex -set
280 Set parameter @var{arg} for item @var{id} of type @var{group}
281 ETEXI
283 DEF("global", HAS_ARG, QEMU_OPTION_global,
284 "-global driver.property=value\n"
285 "-global driver=driver,property=property,value=value\n"
286 " set a global default for a driver property\n",
287 QEMU_ARCH_ALL)
288 STEXI
289 @item -global @var{driver}.@var{prop}=@var{value}
290 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
291 @findex -global
292 Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
294 @example
295 qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
296 @end example
298 In particular, you can use this to set driver properties for devices which are
299 created automatically by the machine model. To create a device which is not
300 created automatically and set properties on it, use -@option{device}.
302 -global @var{driver}.@var{prop}=@var{value} is shorthand for -global
303 driver=@var{driver},property=@var{prop},value=@var{value}. The
304 longhand syntax works even when @var{driver} contains a dot.
305 ETEXI
307 DEF("boot", HAS_ARG, QEMU_OPTION_boot,
308 "-boot [order=drives][,once=drives][,menu=on|off]\n"
309 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
310 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
311 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
312 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
313 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
314 QEMU_ARCH_ALL)
315 STEXI
316 @item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}][,reboot-timeout=@var{rb_timeout}][,strict=on|off]
317 @findex -boot
318 Specify boot order @var{drives} as a string of drive letters. Valid
319 drive letters depend on the target architecture. The x86 PC uses: a, b
320 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
321 from network adapter 1-4), hard disk boot is the default. To apply a
322 particular boot order only on the first startup, specify it via
323 @option{once}. Note that the @option{order} or @option{once} parameter
324 should not be used together with the @option{bootindex} property of
325 devices, since the firmware implementations normally do not support both
326 at the same time.
328 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
329 as firmware/BIOS supports them. The default is non-interactive boot.
331 A splash picture could be passed to bios, enabling user to show it as logo,
332 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
333 supports them. Currently Seabios for X86 system support it.
334 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
335 format(true color). The resolution should be supported by the SVGA mode, so
336 the recommended is 320x240, 640x480, 800x640.
338 A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
339 when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
340 reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
341 system support it.
343 Do strict boot via @option{strict=on} as far as firmware/BIOS
344 supports it. This only effects when boot priority is changed by
345 bootindex options. The default is non-strict boot.
347 @example
348 # try to boot from network first, then from hard disk
349 qemu-system-i386 -boot order=nc
350 # boot from CD-ROM first, switch back to default order after reboot
351 qemu-system-i386 -boot once=d
352 # boot with a splash picture for 5 seconds.
353 qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
354 @end example
356 Note: The legacy format '-boot @var{drives}' is still supported but its
357 use is discouraged as it may be removed from future versions.
358 ETEXI
360 DEF("m", HAS_ARG, QEMU_OPTION_m,
361 "-m [size=]megs[,slots=n,maxmem=size]\n"
362 " configure guest RAM\n"
363 " size: initial amount of guest memory\n"
364 " slots: number of hotplug slots (default: none)\n"
365 " maxmem: maximum amount of guest memory (default: none)\n"
366 "NOTE: Some architectures might enforce a specific granularity\n",
367 QEMU_ARCH_ALL)
368 STEXI
369 @item -m [size=]@var{megs}[,slots=n,maxmem=size]
370 @findex -m
371 Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
372 Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
373 megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
374 could be used to set amount of hotpluggable memory slots and maximum amount of
375 memory. Note that @var{maxmem} must be aligned to the page size.
377 For example, the following command-line sets the guest startup RAM size to
378 1GB, creates 3 slots to hotplug additional memory and sets the maximum
379 memory the guest can reach to 4GB:
381 @example
382 qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
383 @end example
385 If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
386 be enabled and the guest startup RAM will never increase.
387 ETEXI
389 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
390 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
391 STEXI
392 @item -mem-path @var{path}
393 @findex -mem-path
394 Allocate guest RAM from a temporarily created file in @var{path}.
395 ETEXI
397 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
398 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
399 QEMU_ARCH_ALL)
400 STEXI
401 @item -mem-prealloc
402 @findex -mem-prealloc
403 Preallocate memory when using -mem-path.
404 ETEXI
406 DEF("k", HAS_ARG, QEMU_OPTION_k,
407 "-k language use keyboard layout (for example 'fr' for French)\n",
408 QEMU_ARCH_ALL)
409 STEXI
410 @item -k @var{language}
411 @findex -k
412 Use keyboard layout @var{language} (for example @code{fr} for
413 French). This option is only needed where it is not easy to get raw PC
414 keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
415 display). You don't normally need to use it on PC/Linux or PC/Windows
416 hosts.
418 The available layouts are:
419 @example
420 ar de-ch es fo fr-ca hu ja mk no pt-br sv
421 da en-gb et fr fr-ch is lt nl pl ru th
422 de en-us fi fr-be hr it lv nl-be pt sl tr
423 @end example
425 The default is @code{en-us}.
426 ETEXI
429 DEF("audio-help", 0, QEMU_OPTION_audio_help,
430 "-audio-help print list of audio drivers and their options\n",
431 QEMU_ARCH_ALL)
432 STEXI
433 @item -audio-help
434 @findex -audio-help
435 Will show the audio subsystem help: list of drivers, tunable
436 parameters.
437 ETEXI
439 DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
440 "-soundhw c1,... enable audio support\n"
441 " and only specified sound cards (comma separated list)\n"
442 " use '-soundhw help' to get the list of supported cards\n"
443 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
444 STEXI
445 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
446 @findex -soundhw
447 Enable audio and selected sound hardware. Use 'help' to print all
448 available sound hardware.
450 @example
451 qemu-system-i386 -soundhw sb16,adlib disk.img
452 qemu-system-i386 -soundhw es1370 disk.img
453 qemu-system-i386 -soundhw ac97 disk.img
454 qemu-system-i386 -soundhw hda disk.img
455 qemu-system-i386 -soundhw all disk.img
456 qemu-system-i386 -soundhw help
457 @end example
459 Note that Linux's i810_audio OSS kernel (for AC97) module might
460 require manually specifying clocking.
462 @example
463 modprobe i810_audio clocking=48000
464 @end example
465 ETEXI
467 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
468 "-balloon virtio[,addr=str]\n"
469 " enable virtio balloon device (deprecated)\n", QEMU_ARCH_ALL)
470 STEXI
471 @item -balloon virtio[,addr=@var{addr}]
472 @findex -balloon
473 Enable virtio balloon device, optionally with PCI address @var{addr}. This
474 option is deprecated, use @option{--device virtio-balloon} instead.
475 ETEXI
477 DEF("device", HAS_ARG, QEMU_OPTION_device,
478 "-device driver[,prop[=value][,...]]\n"
479 " add device (based on driver)\n"
480 " prop=value,... sets driver properties\n"
481 " use '-device help' to print all possible drivers\n"
482 " use '-device driver,help' to print all possible properties\n",
483 QEMU_ARCH_ALL)
484 STEXI
485 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
486 @findex -device
487 Add device @var{driver}. @var{prop}=@var{value} sets driver
488 properties. Valid properties depend on the driver. To get help on
489 possible drivers and properties, use @code{-device help} and
490 @code{-device @var{driver},help}.
492 Some drivers are:
493 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
495 Add an IPMI BMC. This is a simulation of a hardware management
496 interface processor that normally sits on a system. It provides
497 a watchdog and the ability to reset and power control the system.
498 You need to connect this to an IPMI interface to make it useful
500 The IPMI slave address to use for the BMC. The default is 0x20.
501 This address is the BMC's address on the I2C network of management
502 controllers. If you don't know what this means, it is safe to ignore
505 @table @option
506 @item bmc=@var{id}
507 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
508 @item slave_addr=@var{val}
509 Define slave address to use for the BMC. The default is 0x20.
510 @item sdrfile=@var{file}
511 file containing raw Sensor Data Records (SDR) data. The default is none.
512 @item fruareasize=@var{val}
513 size of a Field Replaceable Unit (FRU) area. The default is 1024.
514 @item frudatafile=@var{file}
515 file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
516 @end table
518 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
520 Add a connection to an external IPMI BMC simulator. Instead of
521 locally emulating the BMC like the above item, instead connect
522 to an external entity that provides the IPMI services.
524 A connection is made to an external BMC simulator. If you do this, it
525 is strongly recommended that you use the "reconnect=" chardev option
526 to reconnect to the simulator if the connection is lost. Note that if
527 this is not used carefully, it can be a security issue, as the
528 interface has the ability to send resets, NMIs, and power off the VM.
529 It's best if QEMU makes a connection to an external simulator running
530 on a secure port on localhost, so neither the simulator nor QEMU is
531 exposed to any outside network.
533 See the "lanserv/README.vm" file in the OpenIPMI library for more
534 details on the external interface.
536 @item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
538 Add a KCS IPMI interafce on the ISA bus. This also adds a
539 corresponding ACPI and SMBIOS entries, if appropriate.
541 @table @option
542 @item bmc=@var{id}
543 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
544 @item ioport=@var{val}
545 Define the I/O address of the interface. The default is 0xca0 for KCS.
546 @item irq=@var{val}
547 Define the interrupt to use. The default is 5. To disable interrupts,
548 set this to 0.
549 @end table
551 @item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
553 Like the KCS interface, but defines a BT interface. The default port is
554 0xe4 and the default interrupt is 5.
556 ETEXI
558 DEF("name", HAS_ARG, QEMU_OPTION_name,
559 "-name string1[,process=string2][,debug-threads=on|off]\n"
560 " set the name of the guest\n"
561 " string1 sets the window title and string2 the process name (on Linux)\n"
562 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
563 " NOTE: The thread names are for debugging and not a stable API.\n",
564 QEMU_ARCH_ALL)
565 STEXI
566 @item -name @var{name}
567 @findex -name
568 Sets the @var{name} of the guest.
569 This name will be displayed in the SDL window caption.
570 The @var{name} will also be used for the VNC server.
571 Also optionally set the top visible process name in Linux.
572 Naming of individual threads can also be enabled on Linux to aid debugging.
573 ETEXI
575 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
576 "-uuid %08x-%04x-%04x-%04x-%012x\n"
577 " specify machine UUID\n", QEMU_ARCH_ALL)
578 STEXI
579 @item -uuid @var{uuid}
580 @findex -uuid
581 Set system UUID.
582 ETEXI
584 STEXI
585 @end table
586 ETEXI
587 DEFHEADING()
589 DEFHEADING(Block device options:)
590 STEXI
591 @table @option
592 ETEXI
594 DEF("fda", HAS_ARG, QEMU_OPTION_fda,
595 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
596 DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
597 STEXI
598 @item -fda @var{file}
599 @itemx -fdb @var{file}
600 @findex -fda
601 @findex -fdb
602 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
603 ETEXI
605 DEF("hda", HAS_ARG, QEMU_OPTION_hda,
606 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
607 DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
608 DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
609 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
610 DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
611 STEXI
612 @item -hda @var{file}
613 @itemx -hdb @var{file}
614 @itemx -hdc @var{file}
615 @itemx -hdd @var{file}
616 @findex -hda
617 @findex -hdb
618 @findex -hdc
619 @findex -hdd
620 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
621 ETEXI
623 DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
624 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
625 QEMU_ARCH_ALL)
626 STEXI
627 @item -cdrom @var{file}
628 @findex -cdrom
629 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
630 @option{-cdrom} at the same time). You can use the host CD-ROM by
631 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
632 ETEXI
634 DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
635 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
636 " [,cache.direct=on|off][,cache.no-flush=on|off]\n"
637 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
638 " [,driver specific parameters...]\n"
639 " configure a block backend\n", QEMU_ARCH_ALL)
640 STEXI
641 @item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
642 @findex -blockdev
644 Define a new block driver node. Some of the options apply to all block drivers,
645 other options are only accepted for a specific block driver. See below for a
646 list of generic options and options for the most common block drivers.
648 Options that expect a reference to another node (e.g. @code{file}) can be
649 given in two ways. Either you specify the node name of an already existing node
650 (file=@var{node-name}), or you define a new node inline, adding options
651 for the referenced node after a dot (file.filename=@var{path},file.aio=native).
653 A block driver node created with @option{-blockdev} can be used for a guest
654 device by specifying its node name for the @code{drive} property in a
655 @option{-device} argument that defines a block device.
657 @table @option
658 @item Valid options for any block driver node:
660 @table @code
661 @item driver
662 Specifies the block driver to use for the given node.
663 @item node-name
664 This defines the name of the block driver node by which it will be referenced
665 later. The name must be unique, i.e. it must not match the name of a different
666 block driver node, or (if you use @option{-drive} as well) the ID of a drive.
668 If no node name is specified, it is automatically generated. The generated node
669 name is not intended to be predictable and changes between QEMU invocations.
670 For the top level, an explicit node name must be specified.
671 @item read-only
672 Open the node read-only. Guest write attempts will fail.
673 @item cache.direct
674 The host page cache can be avoided with @option{cache.direct=on}. This will
675 attempt to do disk IO directly to the guest's memory. QEMU may still perform an
676 internal copy of the data.
677 @item cache.no-flush
678 In case you don't care about data integrity over host failures, you can use
679 @option{cache.no-flush=on}. This option tells QEMU that it never needs to write
680 any data to the disk but can instead keep things in cache. If anything goes
681 wrong, like your host losing power, the disk storage getting disconnected
682 accidentally, etc. your image will most probably be rendered unusable.
683 @item discard=@var{discard}
684 @var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls
685 whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
686 ignored or passed to the filesystem. Some machine types may not support
687 discard requests.
688 @item detect-zeroes=@var{detect-zeroes}
689 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
690 conversion of plain zero writes by the OS to driver specific optimized
691 zero write commands. You may even choose "unmap" if @var{discard} is set
692 to "unmap" to allow a zero write to be converted to an @code{unmap} operation.
693 @end table
695 @item Driver-specific options for @code{file}
697 This is the protocol-level block driver for accessing regular files.
699 @table @code
700 @item filename
701 The path to the image file in the local filesystem
702 @item aio
703 Specifies the AIO backend (threads/native, default: threads)
704 @item locking
705 Specifies whether the image file is protected with Linux OFD / POSIX locks. The
706 default is to use the Linux Open File Descriptor API if available, otherwise no
707 lock is applied. (auto/on/off, default: auto)
708 @end table
709 Example:
710 @example
711 -blockdev driver=file,node-name=disk,filename=disk.img
712 @end example
714 @item Driver-specific options for @code{raw}
716 This is the image format block driver for raw images. It is usually
717 stacked on top of a protocol level block driver such as @code{file}.
719 @table @code
720 @item file
721 Reference to or definition of the data source block driver node
722 (e.g. a @code{file} driver node)
723 @end table
724 Example 1:
725 @example
726 -blockdev driver=file,node-name=disk_file,filename=disk.img
727 -blockdev driver=raw,node-name=disk,file=disk_file
728 @end example
729 Example 2:
730 @example
731 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
732 @end example
734 @item Driver-specific options for @code{qcow2}
736 This is the image format block driver for qcow2 images. It is usually
737 stacked on top of a protocol level block driver such as @code{file}.
739 @table @code
740 @item file
741 Reference to or definition of the data source block driver node
742 (e.g. a @code{file} driver node)
744 @item backing
745 Reference to or definition of the backing file block device (default is taken
746 from the image file). It is allowed to pass @code{null} here in order to disable
747 the default backing file.
749 @item lazy-refcounts
750 Whether to enable the lazy refcounts feature (on/off; default is taken from the
751 image file)
753 @item cache-size
754 The maximum total size of the L2 table and refcount block caches in bytes
755 (default: 1048576 bytes or 8 clusters, whichever is larger)
757 @item l2-cache-size
758 The maximum size of the L2 table cache in bytes
759 (default: 4/5 of the total cache size)
761 @item refcount-cache-size
762 The maximum size of the refcount block cache in bytes
763 (default: 1/5 of the total cache size)
765 @item cache-clean-interval
766 Clean unused entries in the L2 and refcount caches. The interval is in seconds.
767 The default value is 0 and it disables this feature.
769 @item pass-discard-request
770 Whether discard requests to the qcow2 device should be forwarded to the data
771 source (on/off; default: on if discard=unmap is specified, off otherwise)
773 @item pass-discard-snapshot
774 Whether discard requests for the data source should be issued when a snapshot
775 operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
776 default: on)
778 @item pass-discard-other
779 Whether discard requests for the data source should be issued on other
780 occasions where a cluster gets freed (on/off; default: off)
782 @item overlap-check
783 Which overlap checks to perform for writes to the image
784 (none/constant/cached/all; default: cached). For details or finer
785 granularity control refer to the QAPI documentation of @code{blockdev-add}.
786 @end table
788 Example 1:
789 @example
790 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
791 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
792 @end example
793 Example 2:
794 @example
795 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
796 @end example
798 @item Driver-specific options for other drivers
799 Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
801 @end table
803 ETEXI
805 DEF("drive", HAS_ARG, QEMU_OPTION_drive,
806 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
807 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
808 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
809 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
810 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
811 " [,readonly=on|off][,copy-on-read=on|off]\n"
812 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
813 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
814 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
815 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
816 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
817 " [[,iops_size=is]]\n"
818 " [[,group=g]]\n"
819 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
820 STEXI
821 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
822 @findex -drive
824 Define a new drive. This includes creating a block driver node (the backend) as
825 well as a guest device, and is mostly a shortcut for defining the corresponding
826 @option{-blockdev} and @option{-device} options.
828 @option{-drive} accepts all options that are accepted by @option{-blockdev}. In
829 addition, it knows the following options:
831 @table @option
832 @item file=@var{file}
833 This option defines which disk image (@pxref{disk_images}) to use with
834 this drive. If the filename contains comma, you must double it
835 (for instance, "file=my,,file" to use file "my,file").
837 Special files such as iSCSI devices can be specified using protocol
838 specific URLs. See the section for "Device URL Syntax" for more information.
839 @item if=@var{interface}
840 This option defines on which type on interface the drive is connected.
841 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
842 @item bus=@var{bus},unit=@var{unit}
843 These options define where is connected the drive by defining the bus number and
844 the unit id.
845 @item index=@var{index}
846 This option defines where is connected the drive by using an index in the list
847 of available connectors of a given interface type.
848 @item media=@var{media}
849 This option defines the type of the media: disk or cdrom.
850 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
851 Force disk physical geometry and the optional BIOS translation (trans=none or
852 lba). These parameters are deprecated, use the corresponding parameters
853 of @code{-device} instead.
854 @item snapshot=@var{snapshot}
855 @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
856 (see @option{-snapshot}).
857 @item cache=@var{cache}
858 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
859 and controls how the host cache is used to access block data. This is a
860 shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
861 options (as in @option{-blockdev}), and additionally @option{cache.writeback},
862 which provides a default for the @option{write-cache} option of block guest
863 devices (as in @option{-device}). The modes correspond to the following
864 settings:
866 @c Our texi2pod.pl script doesn't support @multitable, so fall back to using
867 @c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
868 @c and the HTML output.
869 @example
870 @ │ cache.writeback cache.direct cache.no-flush
871 ─────────────┼─────────────────────────────────────────────────
872 writeback │ on off off
873 none │ on on off
874 writethrough │ off off off
875 directsync │ off on off
876 unsafe │ on off on
877 @end example
879 The default mode is @option{cache=writeback}.
881 @item aio=@var{aio}
882 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
883 @item format=@var{format}
884 Specify which disk @var{format} will be used rather than detecting
885 the format. Can be used to specify format=raw to avoid interpreting
886 an untrusted format header.
887 @item serial=@var{serial}
888 This option specifies the serial number to assign to the device. This
889 parameter is deprecated, use the corresponding parameter of @code{-device}
890 instead.
891 @item addr=@var{addr}
892 Specify the controller's PCI address (if=virtio only). This parameter is
893 deprecated, use the corresponding parameter of @code{-device} instead.
894 @item werror=@var{action},rerror=@var{action}
895 Specify which @var{action} to take on write and read errors. Valid actions are:
896 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
897 "report" (report the error to the guest), "enospc" (pause QEMU only if the
898 host disk is full; report the error to the guest otherwise).
899 The default setting is @option{werror=enospc} and @option{rerror=report}.
900 @item copy-on-read=@var{copy-on-read}
901 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
902 file sectors into the image file.
903 @item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
904 Specify bandwidth throttling limits in bytes per second, either for all request
905 types or for reads or writes only. Small values can lead to timeouts or hangs
906 inside the guest. A safe minimum for disks is 2 MB/s.
907 @item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
908 Specify bursts in bytes per second, either for all request types or for reads
909 or writes only. Bursts allow the guest I/O to spike above the limit
910 temporarily.
911 @item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
912 Specify request rate limits in requests per second, either for all request
913 types or for reads or writes only.
914 @item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
915 Specify bursts in requests per second, either for all request types or for reads
916 or writes only. Bursts allow the guest I/O to spike above the limit
917 temporarily.
918 @item iops_size=@var{is}
919 Let every @var{is} bytes of a request count as a new request for iops
920 throttling purposes. Use this option to prevent guests from circumventing iops
921 limits by sending fewer but larger requests.
922 @item group=@var{g}
923 Join a throttling quota group with given name @var{g}. All drives that are
924 members of the same group are accounted for together. Use this option to
925 prevent guests from circumventing throttling limits by using many small disks
926 instead of a single larger disk.
927 @end table
929 By default, the @option{cache.writeback=on} mode is used. It will report data
930 writes as completed as soon as the data is present in the host page cache.
931 This is safe as long as your guest OS makes sure to correctly flush disk caches
932 where needed. If your guest OS does not handle volatile disk write caches
933 correctly and your host crashes or loses power, then the guest may experience
934 data corruption.
936 For such guests, you should consider using @option{cache.writeback=off}. This
937 means that the host page cache will be used to read and write data, but write
938 notification will be sent to the guest only after QEMU has made sure to flush
939 each write to the disk. Be aware that this has a major impact on performance.
941 When using the @option{-snapshot} option, unsafe caching is always used.
943 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
944 useful when the backing file is over a slow network. By default copy-on-read
945 is off.
947 Instead of @option{-cdrom} you can use:
948 @example
949 qemu-system-i386 -drive file=file,index=2,media=cdrom
950 @end example
952 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
953 use:
954 @example
955 qemu-system-i386 -drive file=file,index=0,media=disk
956 qemu-system-i386 -drive file=file,index=1,media=disk
957 qemu-system-i386 -drive file=file,index=2,media=disk
958 qemu-system-i386 -drive file=file,index=3,media=disk
959 @end example
961 You can open an image using pre-opened file descriptors from an fd set:
962 @example
963 qemu-system-i386
964 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
965 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
966 -drive file=/dev/fdset/2,index=0,media=disk
967 @end example
969 You can connect a CDROM to the slave of ide0:
970 @example
971 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
972 @end example
974 If you don't specify the "file=" argument, you define an empty drive:
975 @example
976 qemu-system-i386 -drive if=ide,index=1,media=cdrom
977 @end example
979 Instead of @option{-fda}, @option{-fdb}, you can use:
980 @example
981 qemu-system-i386 -drive file=file,index=0,if=floppy
982 qemu-system-i386 -drive file=file,index=1,if=floppy
983 @end example
985 By default, @var{interface} is "ide" and @var{index} is automatically
986 incremented:
987 @example
988 qemu-system-i386 -drive file=a -drive file=b"
989 @end example
990 is interpreted like:
991 @example
992 qemu-system-i386 -hda a -hdb b
993 @end example
994 ETEXI
996 DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
997 "-mtdblock file use 'file' as on-board Flash memory image\n",
998 QEMU_ARCH_ALL)
999 STEXI
1000 @item -mtdblock @var{file}
1001 @findex -mtdblock
1002 Use @var{file} as on-board Flash memory image.
1003 ETEXI
1005 DEF("sd", HAS_ARG, QEMU_OPTION_sd,
1006 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
1007 STEXI
1008 @item -sd @var{file}
1009 @findex -sd
1010 Use @var{file} as SecureDigital card image.
1011 ETEXI
1013 DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
1014 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
1015 STEXI
1016 @item -pflash @var{file}
1017 @findex -pflash
1018 Use @var{file} as a parallel flash image.
1019 ETEXI
1021 DEF("snapshot", 0, QEMU_OPTION_snapshot,
1022 "-snapshot write to temporary files instead of disk image files\n",
1023 QEMU_ARCH_ALL)
1024 STEXI
1025 @item -snapshot
1026 @findex -snapshot
1027 Write to temporary files instead of disk image files. In this case,
1028 the raw disk image you use is not written back. You can however force
1029 the write back by pressing @key{C-a s} (@pxref{disk_images}).
1030 ETEXI
1032 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
1033 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1034 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1035 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1036 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1037 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1038 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1039 " [[,throttling.iops-size=is]]\n",
1040 QEMU_ARCH_ALL)
1042 STEXI
1044 @item -fsdev @var{fsdriver},id=@var{id},path=@var{path},[security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}]
1045 @findex -fsdev
1046 Define a new file system device. Valid options are:
1047 @table @option
1048 @item @var{fsdriver}
1049 This option specifies the fs driver backend to use.
1050 Currently "local", "handle" and "proxy" file system drivers are supported.
1051 @item id=@var{id}
1052 Specifies identifier for this device
1053 @item path=@var{path}
1054 Specifies the export path for the file system device. Files under
1055 this path will be available to the 9p client on the guest.
1056 @item security_model=@var{security_model}
1057 Specifies the security model to be used for this export path.
1058 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1059 In "passthrough" security model, files are stored using the same
1060 credentials as they are created on the guest. This requires QEMU
1061 to run as root. In "mapped-xattr" security model, some of the file
1062 attributes like uid, gid, mode bits and link target are stored as
1063 file attributes. For "mapped-file" these attributes are stored in the
1064 hidden .virtfs_metadata directory. Directories exported by this security model cannot
1065 interact with other unix tools. "none" security model is same as
1066 passthrough except the sever won't report failures if it fails to
1067 set file attributes like ownership. Security model is mandatory
1068 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
1069 security model as a parameter.
1070 @item writeout=@var{writeout}
1071 This is an optional argument. The only supported value is "immediate".
1072 This means that host page cache will be used to read and write data but
1073 write notification will be sent to the guest only when the data has been
1074 reported as written by the storage subsystem.
1075 @item readonly
1076 Enables exporting 9p share as a readonly mount for guests. By default
1077 read-write access is given.
1078 @item socket=@var{socket}
1079 Enables proxy filesystem driver to use passed socket file for communicating
1080 with virtfs-proxy-helper
1081 @item sock_fd=@var{sock_fd}
1082 Enables proxy filesystem driver to use passed socket descriptor for
1083 communicating with virtfs-proxy-helper. Usually a helper like libvirt
1084 will create socketpair and pass one of the fds as sock_fd
1085 @item fmode=@var{fmode}
1086 Specifies the default mode for newly created files on the host. Works only
1087 with security models "mapped-xattr" and "mapped-file".
1088 @item dmode=@var{dmode}
1089 Specifies the default mode for newly created directories on the host. Works
1090 only with security models "mapped-xattr" and "mapped-file".
1091 @end table
1093 -fsdev option is used along with -device driver "virtio-9p-pci".
1094 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
1095 Options for virtio-9p-pci driver are:
1096 @table @option
1097 @item fsdev=@var{id}
1098 Specifies the id value specified along with -fsdev option
1099 @item mount_tag=@var{mount_tag}
1100 Specifies the tag name to be used by the guest to mount this export point
1101 @end table
1103 ETEXI
1105 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
1106 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1107 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1108 QEMU_ARCH_ALL)
1110 STEXI
1112 @item -virtfs @var{fsdriver}[,path=@var{path}],mount_tag=@var{mount_tag}[,security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}]
1113 @findex -virtfs
1115 The general form of a Virtual File system pass-through options are:
1116 @table @option
1117 @item @var{fsdriver}
1118 This option specifies the fs driver backend to use.
1119 Currently "local", "handle" and "proxy" file system drivers are supported.
1120 @item id=@var{id}
1121 Specifies identifier for this device
1122 @item path=@var{path}
1123 Specifies the export path for the file system device. Files under
1124 this path will be available to the 9p client on the guest.
1125 @item security_model=@var{security_model}
1126 Specifies the security model to be used for this export path.
1127 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1128 In "passthrough" security model, files are stored using the same
1129 credentials as they are created on the guest. This requires QEMU
1130 to run as root. In "mapped-xattr" security model, some of the file
1131 attributes like uid, gid, mode bits and link target are stored as
1132 file attributes. For "mapped-file" these attributes are stored in the
1133 hidden .virtfs_metadata directory. Directories exported by this security model cannot
1134 interact with other unix tools. "none" security model is same as
1135 passthrough except the sever won't report failures if it fails to
1136 set file attributes like ownership. Security model is mandatory only
1137 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
1138 model as a parameter.
1139 @item writeout=@var{writeout}
1140 This is an optional argument. The only supported value is "immediate".
1141 This means that host page cache will be used to read and write data but
1142 write notification will be sent to the guest only when the data has been
1143 reported as written by the storage subsystem.
1144 @item readonly
1145 Enables exporting 9p share as a readonly mount for guests. By default
1146 read-write access is given.
1147 @item socket=@var{socket}
1148 Enables proxy filesystem driver to use passed socket file for
1149 communicating with virtfs-proxy-helper. Usually a helper like libvirt
1150 will create socketpair and pass one of the fds as sock_fd
1151 @item sock_fd
1152 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
1153 descriptor for interfacing with virtfs-proxy-helper
1154 @item fmode=@var{fmode}
1155 Specifies the default mode for newly created files on the host. Works only
1156 with security models "mapped-xattr" and "mapped-file".
1157 @item dmode=@var{dmode}
1158 Specifies the default mode for newly created directories on the host. Works
1159 only with security models "mapped-xattr" and "mapped-file".
1160 @end table
1161 ETEXI
1163 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
1164 "-virtfs_synth Create synthetic file system image\n",
1165 QEMU_ARCH_ALL)
1166 STEXI
1167 @item -virtfs_synth
1168 @findex -virtfs_synth
1169 Create synthetic file system image
1170 ETEXI
1172 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1173 "-iscsi [user=user][,password=password]\n"
1174 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1175 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1176 " [,timeout=timeout]\n"
1177 " iSCSI session parameters\n", QEMU_ARCH_ALL)
1179 STEXI
1180 @item -iscsi
1181 @findex -iscsi
1182 Configure iSCSI session parameters.
1183 ETEXI
1185 STEXI
1186 @end table
1187 ETEXI
1188 DEFHEADING()
1190 DEFHEADING(USB options:)
1191 STEXI
1192 @table @option
1193 ETEXI
1195 DEF("usb", 0, QEMU_OPTION_usb,
1196 "-usb enable the USB driver (if it is not used by default yet)\n",
1197 QEMU_ARCH_ALL)
1198 STEXI
1199 @item -usb
1200 @findex -usb
1201 Enable the USB driver (if it is not used by default yet).
1202 ETEXI
1204 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1205 "-usbdevice name add the host or guest USB device 'name'\n",
1206 QEMU_ARCH_ALL)
1207 STEXI
1209 @item -usbdevice @var{devname}
1210 @findex -usbdevice
1211 Add the USB device @var{devname}. Note that this option is deprecated,
1212 please use @code{-device usb-...} instead. @xref{usb_devices}.
1214 @table @option
1216 @item mouse
1217 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1219 @item tablet
1220 Pointer device that uses absolute coordinates (like a touchscreen). This
1221 means QEMU is able to report the mouse position without having to grab the
1222 mouse. Also overrides the PS/2 mouse emulation when activated.
1224 @item braille
1225 Braille device. This will use BrlAPI to display the braille output on a real
1226 or fake device.
1228 @end table
1229 ETEXI
1231 STEXI
1232 @end table
1233 ETEXI
1234 DEFHEADING()
1236 DEFHEADING(Display options:)
1237 STEXI
1238 @table @option
1239 ETEXI
1241 DEF("display", HAS_ARG, QEMU_OPTION_display,
1242 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1243 " [,window_close=on|off][,gl=on|off]\n"
1244 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1245 "-display vnc=<display>[,<optargs>]\n"
1246 "-display curses\n"
1247 "-display none"
1248 " select display type\n"
1249 "The default display is equivalent to\n"
1250 #if defined(CONFIG_GTK)
1251 "\t\"-display gtk\"\n"
1252 #elif defined(CONFIG_SDL)
1253 "\t\"-display sdl\"\n"
1254 #elif defined(CONFIG_COCOA)
1255 "\t\"-display cocoa\"\n"
1256 #elif defined(CONFIG_VNC)
1257 "\t\"-vnc localhost:0,to=99,id=default\"\n"
1258 #else
1259 "\t\"-display none\"\n"
1260 #endif
1261 , QEMU_ARCH_ALL)
1262 STEXI
1263 @item -display @var{type}
1264 @findex -display
1265 Select type of display to use. This option is a replacement for the
1266 old style -sdl/-curses/... options. Valid values for @var{type} are
1267 @table @option
1268 @item sdl
1269 Display video output via SDL (usually in a separate graphics
1270 window; see the SDL documentation for other possibilities).
1271 @item curses
1272 Display video output via curses. For graphics device models which
1273 support a text mode, QEMU can display this output using a
1274 curses/ncurses interface. Nothing is displayed when the graphics
1275 device is in graphical mode or if the graphics device does not support
1276 a text mode. Generally only the VGA device models support text mode.
1277 @item none
1278 Do not display video output. The guest will still see an emulated
1279 graphics card, but its output will not be displayed to the QEMU
1280 user. This option differs from the -nographic option in that it
1281 only affects what is done with video output; -nographic also changes
1282 the destination of the serial and parallel port data.
1283 @item gtk
1284 Display video output in a GTK window. This interface provides drop-down
1285 menus and other UI elements to configure and control the VM during
1286 runtime.
1287 @item vnc
1288 Start a VNC server on display <arg>
1289 @end table
1290 ETEXI
1292 DEF("nographic", 0, QEMU_OPTION_nographic,
1293 "-nographic disable graphical output and redirect serial I/Os to console\n",
1294 QEMU_ARCH_ALL)
1295 STEXI
1296 @item -nographic
1297 @findex -nographic
1298 Normally, if QEMU is compiled with graphical window support, it displays
1299 output such as guest graphics, guest console, and the QEMU monitor in a
1300 window. With this option, you can totally disable graphical output so
1301 that QEMU is a simple command line application. The emulated serial port
1302 is redirected on the console and muxed with the monitor (unless
1303 redirected elsewhere explicitly). Therefore, you can still use QEMU to
1304 debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1305 switching between the console and monitor.
1306 ETEXI
1308 DEF("curses", 0, QEMU_OPTION_curses,
1309 "-curses shorthand for -display curses\n",
1310 QEMU_ARCH_ALL)
1311 STEXI
1312 @item -curses
1313 @findex -curses
1314 Normally, if QEMU is compiled with graphical window support, it displays
1315 output such as guest graphics, guest console, and the QEMU monitor in a
1316 window. With this option, QEMU can display the VGA output when in text
1317 mode using a curses/ncurses interface. Nothing is displayed in graphical
1318 mode.
1319 ETEXI
1321 DEF("no-frame", 0, QEMU_OPTION_no_frame,
1322 "-no-frame open SDL window without a frame and window decorations\n",
1323 QEMU_ARCH_ALL)
1324 STEXI
1325 @item -no-frame
1326 @findex -no-frame
1327 Do not use decorations for SDL windows and start them using the whole
1328 available screen space. This makes the using QEMU in a dedicated desktop
1329 workspace more convenient.
1330 ETEXI
1332 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1333 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1334 QEMU_ARCH_ALL)
1335 STEXI
1336 @item -alt-grab
1337 @findex -alt-grab
1338 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1339 affects the special keys (for fullscreen, monitor-mode switching, etc).
1340 ETEXI
1342 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1343 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1344 QEMU_ARCH_ALL)
1345 STEXI
1346 @item -ctrl-grab
1347 @findex -ctrl-grab
1348 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1349 affects the special keys (for fullscreen, monitor-mode switching, etc).
1350 ETEXI
1352 DEF("no-quit", 0, QEMU_OPTION_no_quit,
1353 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
1354 STEXI
1355 @item -no-quit
1356 @findex -no-quit
1357 Disable SDL window close capability.
1358 ETEXI
1360 DEF("sdl", 0, QEMU_OPTION_sdl,
1361 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL)
1362 STEXI
1363 @item -sdl
1364 @findex -sdl
1365 Enable SDL.
1366 ETEXI
1368 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1369 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1370 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1371 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1372 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1373 " [,tls-ciphers=<list>]\n"
1374 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1375 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1376 " [,sasl][,password=<secret>][,disable-ticketing]\n"
1377 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1378 " [,jpeg-wan-compression=[auto|never|always]]\n"
1379 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
1380 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1381 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1382 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1383 " [,gl=[on|off]][,rendernode=<file>]\n"
1384 " enable spice\n"
1385 " at least one of {port, tls-port} is mandatory\n",
1386 QEMU_ARCH_ALL)
1387 STEXI
1388 @item -spice @var{option}[,@var{option}[,...]]
1389 @findex -spice
1390 Enable the spice remote desktop protocol. Valid options are
1392 @table @option
1394 @item port=<nr>
1395 Set the TCP port spice is listening on for plaintext channels.
1397 @item addr=<addr>
1398 Set the IP address spice is listening on. Default is any address.
1400 @item ipv4
1401 @itemx ipv6
1402 @itemx unix
1403 Force using the specified IP version.
1405 @item password=<secret>
1406 Set the password you need to authenticate.
1408 @item sasl
1409 Require that the client use SASL to authenticate with the spice.
1410 The exact choice of authentication method used is controlled from the
1411 system / user's SASL configuration file for the 'qemu' service. This
1412 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1413 unprivileged user, an environment variable SASL_CONF_PATH can be used
1414 to make it search alternate locations for the service config.
1415 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1416 it is recommended that SASL always be combined with the 'tls' and
1417 'x509' settings to enable use of SSL and server certificates. This
1418 ensures a data encryption preventing compromise of authentication
1419 credentials.
1421 @item disable-ticketing
1422 Allow client connects without authentication.
1424 @item disable-copy-paste
1425 Disable copy paste between the client and the guest.
1427 @item disable-agent-file-xfer
1428 Disable spice-vdagent based file-xfer between the client and the guest.
1430 @item tls-port=<nr>
1431 Set the TCP port spice is listening on for encrypted channels.
1433 @item x509-dir=<dir>
1434 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1436 @item x509-key-file=<file>
1437 @itemx x509-key-password=<file>
1438 @itemx x509-cert-file=<file>
1439 @itemx x509-cacert-file=<file>
1440 @itemx x509-dh-key-file=<file>
1441 The x509 file names can also be configured individually.
1443 @item tls-ciphers=<list>
1444 Specify which ciphers to use.
1446 @item tls-channel=[main|display|cursor|inputs|record|playback]
1447 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1448 Force specific channel to be used with or without TLS encryption. The
1449 options can be specified multiple times to configure multiple
1450 channels. The special name "default" can be used to set the default
1451 mode. For channels which are not explicitly forced into one mode the
1452 spice client is allowed to pick tls/plaintext as he pleases.
1454 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1455 Configure image compression (lossless).
1456 Default is auto_glz.
1458 @item jpeg-wan-compression=[auto|never|always]
1459 @itemx zlib-glz-wan-compression=[auto|never|always]
1460 Configure wan image compression (lossy for slow links).
1461 Default is auto.
1463 @item streaming-video=[off|all|filter]
1464 Configure video stream detection. Default is off.
1466 @item agent-mouse=[on|off]
1467 Enable/disable passing mouse events via vdagent. Default is on.
1469 @item playback-compression=[on|off]
1470 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1472 @item seamless-migration=[on|off]
1473 Enable/disable spice seamless migration. Default is off.
1475 @item gl=[on|off]
1476 Enable/disable OpenGL context. Default is off.
1478 @item rendernode=<file>
1479 DRM render node for OpenGL rendering. If not specified, it will pick
1480 the first available. (Since 2.9)
1482 @end table
1483 ETEXI
1485 DEF("portrait", 0, QEMU_OPTION_portrait,
1486 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1487 QEMU_ARCH_ALL)
1488 STEXI
1489 @item -portrait
1490 @findex -portrait
1491 Rotate graphical output 90 deg left (only PXA LCD).
1492 ETEXI
1494 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1495 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1496 QEMU_ARCH_ALL)
1497 STEXI
1498 @item -rotate @var{deg}
1499 @findex -rotate
1500 Rotate graphical output some deg left (only PXA LCD).
1501 ETEXI
1503 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1504 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1505 " select video card type\n", QEMU_ARCH_ALL)
1506 STEXI
1507 @item -vga @var{type}
1508 @findex -vga
1509 Select type of VGA card to emulate. Valid values for @var{type} are
1510 @table @option
1511 @item cirrus
1512 Cirrus Logic GD5446 Video card. All Windows versions starting from
1513 Windows 95 should recognize and use this graphic card. For optimal
1514 performances, use 16 bit color depth in the guest and the host OS.
1515 (This card was the default before QEMU 2.2)
1516 @item std
1517 Standard VGA card with Bochs VBE extensions. If your guest OS
1518 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1519 to use high resolution modes (>= 1280x1024x16) then you should use
1520 this option. (This card is the default since QEMU 2.2)
1521 @item vmware
1522 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1523 recent XFree86/XOrg server or Windows guest with a driver for this
1524 card.
1525 @item qxl
1526 QXL paravirtual graphic card. It is VGA compatible (including VESA
1527 2.0 VBE support). Works best with qxl guest drivers installed though.
1528 Recommended choice when using the spice protocol.
1529 @item tcx
1530 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1531 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1532 fixed resolution of 1024x768.
1533 @item cg3
1534 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1535 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1536 resolutions aimed at people wishing to run older Solaris versions.
1537 @item virtio
1538 Virtio VGA card.
1539 @item none
1540 Disable VGA card.
1541 @end table
1542 ETEXI
1544 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1545 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1546 STEXI
1547 @item -full-screen
1548 @findex -full-screen
1549 Start in full screen.
1550 ETEXI
1552 DEF("g", 1, QEMU_OPTION_g ,
1553 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1554 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1555 STEXI
1556 @item -g @var{width}x@var{height}[x@var{depth}]
1557 @findex -g
1558 Set the initial graphical resolution and depth (PPC, SPARC only).
1559 ETEXI
1561 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1562 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1563 STEXI
1564 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1565 @findex -vnc
1566 Normally, if QEMU is compiled with graphical window support, it displays
1567 output such as guest graphics, guest console, and the QEMU monitor in a
1568 window. With this option, you can have QEMU listen on VNC display
1569 @var{display} and redirect the VGA display over the VNC session. It is
1570 very useful to enable the usb tablet device when using this option
1571 (option @option{-device usb-tablet}). When using the VNC display, you
1572 must use the @option{-k} parameter to set the keyboard layout if you are
1573 not using en-us. Valid syntax for the @var{display} is
1575 @table @option
1577 @item to=@var{L}
1579 With this option, QEMU will try next available VNC @var{display}s, until the
1580 number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1581 available, e.g. port 5900+@var{display} is already used by another
1582 application. By default, to=0.
1584 @item @var{host}:@var{d}
1586 TCP connections will only be allowed from @var{host} on display @var{d}.
1587 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1588 be omitted in which case the server will accept connections from any host.
1590 @item unix:@var{path}
1592 Connections will be allowed over UNIX domain sockets where @var{path} is the
1593 location of a unix socket to listen for connections on.
1595 @item none
1597 VNC is initialized but not started. The monitor @code{change} command
1598 can be used to later start the VNC server.
1600 @end table
1602 Following the @var{display} value there may be one or more @var{option} flags
1603 separated by commas. Valid options are
1605 @table @option
1607 @item reverse
1609 Connect to a listening VNC client via a ``reverse'' connection. The
1610 client is specified by the @var{display}. For reverse network
1611 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1612 is a TCP port number, not a display number.
1614 @item websocket
1616 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1617 If a bare @var{websocket} option is given, the Websocket port is
1618 5700+@var{display}. An alternative port can be specified with the
1619 syntax @code{websocket}=@var{port}.
1621 If @var{host} is specified connections will only be allowed from this host.
1622 It is possible to control the websocket listen address independently, using
1623 the syntax @code{websocket}=@var{host}:@var{port}.
1625 If no TLS credentials are provided, the websocket connection runs in
1626 unencrypted mode. If TLS credentials are provided, the websocket connection
1627 requires encrypted client connections.
1629 @item password
1631 Require that password based authentication is used for client connections.
1633 The password must be set separately using the @code{set_password} command in
1634 the @ref{pcsys_monitor}. The syntax to change your password is:
1635 @code{set_password <protocol> <password>} where <protocol> could be either
1636 "vnc" or "spice".
1638 If you would like to change <protocol> password expiration, you should use
1639 @code{expire_password <protocol> <expiration-time>} where expiration time could
1640 be one of the following options: now, never, +seconds or UNIX time of
1641 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1642 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1643 date and time).
1645 You can also use keywords "now" or "never" for the expiration time to
1646 allow <protocol> password to expire immediately or never expire.
1648 @item tls-creds=@var{ID}
1650 Provides the ID of a set of TLS credentials to use to secure the
1651 VNC server. They will apply to both the normal VNC server socket
1652 and the websocket socket (if enabled). Setting TLS credentials
1653 will cause the VNC server socket to enable the VeNCrypt auth
1654 mechanism. The credentials should have been previously created
1655 using the @option{-object tls-creds} argument.
1657 The @option{tls-creds} parameter obsoletes the @option{tls},
1658 @option{x509}, and @option{x509verify} options, and as such
1659 it is not permitted to set both new and old type options at
1660 the same time.
1662 @item tls
1664 Require that client use TLS when communicating with the VNC server. This
1665 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1666 attack. It is recommended that this option be combined with either the
1667 @option{x509} or @option{x509verify} options.
1669 This option is now deprecated in favor of using the @option{tls-creds}
1670 argument.
1672 @item x509=@var{/path/to/certificate/dir}
1674 Valid if @option{tls} is specified. Require that x509 credentials are used
1675 for negotiating the TLS session. The server will send its x509 certificate
1676 to the client. It is recommended that a password be set on the VNC server
1677 to provide authentication of the client when this is used. The path following
1678 this option specifies where the x509 certificates are to be loaded from.
1679 See the @ref{vnc_security} section for details on generating certificates.
1681 This option is now deprecated in favour of using the @option{tls-creds}
1682 argument.
1684 @item x509verify=@var{/path/to/certificate/dir}
1686 Valid if @option{tls} is specified. Require that x509 credentials are used
1687 for negotiating the TLS session. The server will send its x509 certificate
1688 to the client, and request that the client send its own x509 certificate.
1689 The server will validate the client's certificate against the CA certificate,
1690 and reject clients when validation fails. If the certificate authority is
1691 trusted, this is a sufficient authentication mechanism. You may still wish
1692 to set a password on the VNC server as a second authentication layer. The
1693 path following this option specifies where the x509 certificates are to
1694 be loaded from. See the @ref{vnc_security} section for details on generating
1695 certificates.
1697 This option is now deprecated in favour of using the @option{tls-creds}
1698 argument.
1700 @item sasl
1702 Require that the client use SASL to authenticate with the VNC server.
1703 The exact choice of authentication method used is controlled from the
1704 system / user's SASL configuration file for the 'qemu' service. This
1705 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1706 unprivileged user, an environment variable SASL_CONF_PATH can be used
1707 to make it search alternate locations for the service config.
1708 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1709 it is recommended that SASL always be combined with the 'tls' and
1710 'x509' settings to enable use of SSL and server certificates. This
1711 ensures a data encryption preventing compromise of authentication
1712 credentials. See the @ref{vnc_security} section for details on using
1713 SASL authentication.
1715 @item acl
1717 Turn on access control lists for checking of the x509 client certificate
1718 and SASL party. For x509 certs, the ACL check is made against the
1719 certificate's distinguished name. This is something that looks like
1720 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1721 made against the username, which depending on the SASL plugin, may
1722 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1723 When the @option{acl} flag is set, the initial access list will be
1724 empty, with a @code{deny} policy. Thus no one will be allowed to
1725 use the VNC server until the ACLs have been loaded. This can be
1726 achieved using the @code{acl} monitor command.
1728 @item lossy
1730 Enable lossy compression methods (gradient, JPEG, ...). If this
1731 option is set, VNC client may receive lossy framebuffer updates
1732 depending on its encoding settings. Enabling this option can save
1733 a lot of bandwidth at the expense of quality.
1735 @item non-adaptive
1737 Disable adaptive encodings. Adaptive encodings are enabled by default.
1738 An adaptive encoding will try to detect frequently updated screen regions,
1739 and send updates in these regions using a lossy encoding (like JPEG).
1740 This can be really helpful to save bandwidth when playing videos. Disabling
1741 adaptive encodings restores the original static behavior of encodings
1742 like Tight.
1744 @item share=[allow-exclusive|force-shared|ignore]
1746 Set display sharing policy. 'allow-exclusive' allows clients to ask
1747 for exclusive access. As suggested by the rfb spec this is
1748 implemented by dropping other connections. Connecting multiple
1749 clients in parallel requires all clients asking for a shared session
1750 (vncviewer: -shared switch). This is the default. 'force-shared'
1751 disables exclusive client access. Useful for shared desktop sessions,
1752 where you don't want someone forgetting specify -shared disconnect
1753 everybody else. 'ignore' completely ignores the shared flag and
1754 allows everybody connect unconditionally. Doesn't conform to the rfb
1755 spec but is traditional QEMU behavior.
1757 @item key-delay-ms
1759 Set keyboard delay, for key down and key up events, in milliseconds.
1760 Default is 10. Keyboards are low-bandwidth devices, so this slowdown
1761 can help the device and guest to keep up and not lose events in case
1762 events are arriving in bulk. Possible causes for the latter are flaky
1763 network connections, or scripts for automated testing.
1765 @end table
1766 ETEXI
1768 STEXI
1769 @end table
1770 ETEXI
1771 ARCHHEADING(, QEMU_ARCH_I386)
1773 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1774 STEXI
1775 @table @option
1776 ETEXI
1778 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1779 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1780 QEMU_ARCH_I386)
1781 STEXI
1782 @item -win2k-hack
1783 @findex -win2k-hack
1784 Use it when installing Windows 2000 to avoid a disk full bug. After
1785 Windows 2000 is installed, you no longer need this option (this option
1786 slows down the IDE transfers).
1787 ETEXI
1789 HXCOMM Deprecated by -rtc
1790 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1792 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1793 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1794 QEMU_ARCH_I386)
1795 STEXI
1796 @item -no-fd-bootchk
1797 @findex -no-fd-bootchk
1798 Disable boot signature checking for floppy disks in BIOS. May
1799 be needed to boot from old floppy disks.
1800 ETEXI
1802 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1803 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1804 STEXI
1805 @item -no-acpi
1806 @findex -no-acpi
1807 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1808 it if your guest OS complains about ACPI problems (PC target machine
1809 only).
1810 ETEXI
1812 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1813 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1814 STEXI
1815 @item -no-hpet
1816 @findex -no-hpet
1817 Disable HPET support.
1818 ETEXI
1820 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1821 "-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"
1822 " ACPI table description\n", QEMU_ARCH_I386)
1823 STEXI
1824 @item -acpitable [sig=@var{str}][,rev=@var{n}][,oem_id=@var{str}][,oem_table_id=@var{str}][,oem_rev=@var{n}] [,asl_compiler_id=@var{str}][,asl_compiler_rev=@var{n}][,data=@var{file1}[:@var{file2}]...]
1825 @findex -acpitable
1826 Add ACPI table with specified header fields and context from specified files.
1827 For file=, take whole ACPI table from the specified files, including all
1828 ACPI headers (possible overridden by other options).
1829 For data=, only data
1830 portion of the table is used, all header information is specified in the
1831 command line.
1832 If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1833 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1834 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1835 spec.
1836 ETEXI
1838 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1839 "-smbios file=binary\n"
1840 " load SMBIOS entry from binary file\n"
1841 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1842 " [,uefi=on|off]\n"
1843 " specify SMBIOS type 0 fields\n"
1844 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1845 " [,uuid=uuid][,sku=str][,family=str]\n"
1846 " specify SMBIOS type 1 fields\n"
1847 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1848 " [,asset=str][,location=str]\n"
1849 " specify SMBIOS type 2 fields\n"
1850 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1851 " [,sku=str]\n"
1852 " specify SMBIOS type 3 fields\n"
1853 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1854 " [,asset=str][,part=str]\n"
1855 " specify SMBIOS type 4 fields\n"
1856 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1857 " [,asset=str][,part=str][,speed=%d]\n"
1858 " specify SMBIOS type 17 fields\n",
1859 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1860 STEXI
1861 @item -smbios file=@var{binary}
1862 @findex -smbios
1863 Load SMBIOS entry from binary file.
1865 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1866 Specify SMBIOS type 0 fields
1868 @item -smbios type=1[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,uuid=@var{uuid}][,sku=@var{str}][,family=@var{str}]
1869 Specify SMBIOS type 1 fields
1871 @item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}][,family=@var{str}]
1872 Specify SMBIOS type 2 fields
1874 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1875 Specify SMBIOS type 3 fields
1877 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1878 Specify SMBIOS type 4 fields
1880 @item -smbios type=17[,loc_pfx=@var{str}][,bank=@var{str}][,manufacturer=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}][,speed=@var{%d}]
1881 Specify SMBIOS type 17 fields
1882 ETEXI
1884 STEXI
1885 @end table
1886 ETEXI
1887 DEFHEADING()
1889 DEFHEADING(Network options:)
1890 STEXI
1891 @table @option
1892 ETEXI
1894 HXCOMM Legacy slirp options (now moved to -net user):
1895 #ifdef CONFIG_SLIRP
1896 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1897 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1898 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1899 #ifndef _WIN32
1900 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1901 #endif
1902 #endif
1904 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1905 #ifdef CONFIG_SLIRP
1906 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1907 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1908 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1909 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
1910 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1911 #ifndef _WIN32
1912 "[,smb=dir[,smbserver=addr]]\n"
1913 #endif
1914 " configure a user mode network backend with ID 'str',\n"
1915 " its DHCP server and optional services\n"
1916 #endif
1917 #ifdef _WIN32
1918 "-netdev tap,id=str,ifname=name\n"
1919 " configure a host TAP network backend with ID 'str'\n"
1920 #else
1921 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1922 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1923 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1924 " [,poll-us=n]\n"
1925 " configure a host TAP network backend with ID 'str'\n"
1926 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1927 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1928 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1929 " to deconfigure it\n"
1930 " use '[down]script=no' to disable script execution\n"
1931 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1932 " configure it\n"
1933 " use 'fd=h' to connect to an already opened TAP interface\n"
1934 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1935 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1936 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1937 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1938 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1939 " use vhost=on to enable experimental in kernel accelerator\n"
1940 " (only has effect for virtio guests which use MSIX)\n"
1941 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1942 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
1943 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1944 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1945 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1946 " spent on busy polling for vhost net\n"
1947 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1948 " configure a host TAP network backend with ID 'str' that is\n"
1949 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1950 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1951 #endif
1952 #ifdef __linux__
1953 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1954 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1955 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1956 " [,rxcookie=rxcookie][,offset=offset]\n"
1957 " configure a network backend with ID 'str' connected to\n"
1958 " an Ethernet over L2TPv3 pseudowire.\n"
1959 " Linux kernel 3.3+ as well as most routers can talk\n"
1960 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1961 " VM to a router and even VM to Host. It is a nearly-universal\n"
1962 " standard (RFC3391). Note - this implementation uses static\n"
1963 " pre-configured tunnels (same as the Linux kernel).\n"
1964 " use 'src=' to specify source address\n"
1965 " use 'dst=' to specify destination address\n"
1966 " use 'udp=on' to specify udp encapsulation\n"
1967 " use 'srcport=' to specify source udp port\n"
1968 " use 'dstport=' to specify destination udp port\n"
1969 " use 'ipv6=on' to force v6\n"
1970 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1971 " well as a weak security measure\n"
1972 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
1973 " use 'txcookie=0x012345678' to specify a txcookie\n"
1974 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1975 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1976 " use 'pincounter=on' to work around broken counter handling in peer\n"
1977 " use 'offset=X' to add an extra offset between header and data\n"
1978 #endif
1979 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1980 " configure a network backend to connect to another network\n"
1981 " using a socket connection\n"
1982 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1983 " configure a network backend to connect to a multicast maddr and port\n"
1984 " use 'localaddr=addr' to specify the host address to send packets from\n"
1985 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1986 " configure a network backend to connect to another network\n"
1987 " using an UDP tunnel\n"
1988 #ifdef CONFIG_VDE
1989 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1990 " configure a network backend to connect to port 'n' of a vde switch\n"
1991 " running on host and listening for incoming connections on 'socketpath'.\n"
1992 " Use group 'groupname' and mode 'octalmode' to change default\n"
1993 " ownership and permissions for communication port.\n"
1994 #endif
1995 #ifdef CONFIG_NETMAP
1996 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1997 " attach to the existing netmap-enabled network interface 'name', or to a\n"
1998 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1999 " netmap device, defaults to '/dev/netmap')\n"
2000 #endif
2001 #ifdef CONFIG_POSIX
2002 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2003 " configure a vhost-user network, backed by a chardev 'dev'\n"
2004 #endif
2005 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
2006 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
2007 DEF("nic", HAS_ARG, QEMU_OPTION_nic,
2008 "--nic [tap|bridge|"
2009 #ifdef CONFIG_SLIRP
2010 "user|"
2011 #endif
2012 #ifdef __linux__
2013 "l2tpv3|"
2014 #endif
2015 #ifdef CONFIG_VDE
2016 "vde|"
2017 #endif
2018 #ifdef CONFIG_NETMAP
2019 "netmap|"
2020 #endif
2021 #ifdef CONFIG_POSIX
2022 "vhost-user|"
2023 #endif
2024 "socket][,option][,...][mac=macaddr]\n"
2025 " initialize an on-board / default host NIC (using MAC address\n"
2026 " macaddr) and connect it to the given host network backend\n"
2027 "--nic none use it alone to have zero network devices (the default is to\n"
2028 " provided a 'user' network connection)\n",
2029 QEMU_ARCH_ALL)
2030 DEF("net", HAS_ARG, QEMU_OPTION_net,
2031 "-net nic[,vlan=n][,netdev=nd][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
2032 " configure or create an on-board (or machine default) NIC and\n"
2033 " connect it either to VLAN 'n' or the netdev 'nd' (for pluggable\n"
2034 " NICs please use '-device devtype,netdev=nd' instead)\n"
2035 "-net ["
2036 #ifdef CONFIG_SLIRP
2037 "user|"
2038 #endif
2039 "tap|"
2040 "bridge|"
2041 #ifdef CONFIG_VDE
2042 "vde|"
2043 #endif
2044 #ifdef CONFIG_NETMAP
2045 "netmap|"
2046 #endif
2047 "socket][,vlan=n][,option][,option][,...]\n"
2048 " old way to initialize a host network interface\n"
2049 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2050 STEXI
2051 @item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]
2052 @findex -nic
2053 This option is a shortcut for configuring both the on-board (default) guest
2054 NIC hardware and the host network backend in one go. The host backend options
2055 are the same as with the corresponding @option{-netdev} options below.
2056 The guest NIC model can be set with @option{model=@var{modelname}}.
2057 Use @option{model=help} to list the available device types.
2058 The hardware MAC address can be set with @option{mac=@var{macaddr}}.
2060 The following two example do exactly the same, to show how @option{-nic} can
2061 be used to shorten the command line length (note that the e1000 is the default
2062 on i386, so the @option{model=e1000} parameter could even be omitted here, too):
2063 @example
2064 qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
2065 qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2066 @end example
2068 @item -nic none
2069 Indicate that no network devices should be configured. It is used to override
2070 the default configuration (default NIC with ``user'' host network backend)
2071 which is activated if no other networking options are provided.
2073 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2074 @findex -netdev
2075 Configure user mode host network backend which requires no administrator
2076 privilege to run. Valid options are:
2078 @table @option
2079 @item id=@var{id}
2080 Assign symbolic name for use in monitor commands.
2082 @item ipv4=on|off and ipv6=on|off
2083 Specify that either IPv4 or IPv6 must be enabled. If neither is specified
2084 both protocols are enabled.
2086 @item net=@var{addr}[/@var{mask}]
2087 Set IP network address the guest will see. Optionally specify the netmask,
2088 either in the form a.b.c.d or as number of valid top-most bits. Default is
2089 10.0.2.0/24.
2091 @item host=@var{addr}
2092 Specify the guest-visible address of the host. Default is the 2nd IP in the
2093 guest network, i.e. x.x.x.2.
2095 @item ipv6-net=@var{addr}[/@var{int}]
2096 Set IPv6 network address the guest will see (default is fec0::/64). The
2097 network prefix is given in the usual hexadecimal IPv6 address
2098 notation. The prefix size is optional, and is given as the number of
2099 valid top-most bits (default is 64).
2101 @item ipv6-host=@var{addr}
2102 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2103 the guest network, i.e. xxxx::2.
2105 @item restrict=on|off
2106 If this option is enabled, the guest will be isolated, i.e. it will not be
2107 able to contact the host and no guest IP packets will be routed over the host
2108 to the outside. This option does not affect any explicitly set forwarding rules.
2110 @item hostname=@var{name}
2111 Specifies the client hostname reported by the built-in DHCP server.
2113 @item dhcpstart=@var{addr}
2114 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2115 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2117 @item dns=@var{addr}
2118 Specify the guest-visible address of the virtual nameserver. The address must
2119 be different from the host address. Default is the 3rd IP in the guest network,
2120 i.e. x.x.x.3.
2122 @item ipv6-dns=@var{addr}
2123 Specify the guest-visible address of the IPv6 virtual nameserver. The address
2124 must be different from the host address. Default is the 3rd IP in the guest
2125 network, i.e. xxxx::3.
2127 @item dnssearch=@var{domain}
2128 Provides an entry for the domain-search list sent by the built-in
2129 DHCP server. More than one domain suffix can be transmitted by specifying
2130 this option multiple times. If supported, this will cause the guest to
2131 automatically try to append the given domain suffix(es) in case a domain name
2132 can not be resolved.
2134 Example:
2135 @example
2136 qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2137 @end example
2139 @item tftp=@var{dir}
2140 When using the user mode network stack, activate a built-in TFTP
2141 server. The files in @var{dir} will be exposed as the root of a TFTP server.
2142 The TFTP client on the guest must be configured in binary mode (use the command
2143 @code{bin} of the Unix TFTP client).
2145 @item bootfile=@var{file}
2146 When using the user mode network stack, broadcast @var{file} as the BOOTP
2147 filename. In conjunction with @option{tftp}, this can be used to network boot
2148 a guest from a local directory.
2150 Example (using pxelinux):
2151 @example
2152 qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2153 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2154 @end example
2156 @item smb=@var{dir}[,smbserver=@var{addr}]
2157 When using the user mode network stack, activate a built-in SMB
2158 server so that Windows OSes can access to the host files in @file{@var{dir}}
2159 transparently. The IP address of the SMB server can be set to @var{addr}. By
2160 default the 4th IP in the guest network is used, i.e. x.x.x.4.
2162 In the guest Windows OS, the line:
2163 @example
2164 10.0.2.4 smbserver
2165 @end example
2166 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2167 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2169 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2171 Note that a SAMBA server must be installed on the host OS.
2173 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2174 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2175 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2176 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2177 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2178 be bound to a specific host interface. If no connection type is set, TCP is
2179 used. This option can be given multiple times.
2181 For example, to redirect host X11 connection from screen 1 to guest
2182 screen 0, use the following:
2184 @example
2185 # on the host
2186 qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2187 # this host xterm should open in the guest X11 server
2188 xterm -display :1
2189 @end example
2191 To redirect telnet connections from host port 5555 to telnet port on
2192 the guest, use the following:
2194 @example
2195 # on the host
2196 qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2197 telnet localhost 5555
2198 @end example
2200 Then when you use on the host @code{telnet localhost 5555}, you
2201 connect to the guest telnet server.
2203 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2204 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2205 Forward guest TCP connections to the IP address @var{server} on port @var{port}
2206 to the character device @var{dev} or to a program executed by @var{cmd:command}
2207 which gets spawned for each connection. This option can be given multiple times.
2209 You can either use a chardev directly and have that one used throughout QEMU's
2210 lifetime, like in the following example:
2212 @example
2213 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2214 # the guest accesses it
2215 qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
2216 @end example
2218 Or you can execute a command on every TCP connection established by the guest,
2219 so that QEMU behaves similar to an inetd process for that virtual server:
2221 @example
2222 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2223 # and connect the TCP stream to its stdin/stdout
2224 qemu-system-i386 -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2225 @end example
2227 @end table
2229 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2230 processed and applied to -net user. Mixing them with the new configuration
2231 syntax gives undefined results. Their use for new applications is discouraged
2232 as they will be removed from future versions.
2234 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2235 Configure a host TAP network backend with ID @var{id}.
2237 Use the network script @var{file} to configure it and the network script
2238 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2239 automatically provides one. The default network configure script is
2240 @file{/etc/qemu-ifup} and the default network deconfigure script is
2241 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2242 to disable script execution.
2244 If running QEMU as an unprivileged user, use the network helper
2245 @var{helper} to configure the TAP interface and attach it to the bridge.
2246 The default network helper executable is @file{/path/to/qemu-bridge-helper}
2247 and the default bridge device is @file{br0}.
2249 @option{fd}=@var{h} can be used to specify the handle of an already
2250 opened host TAP interface.
2252 Examples:
2254 @example
2255 #launch a QEMU instance with the default network script
2256 qemu-system-i386 linux.img -nic tap
2257 @end example
2259 @example
2260 #launch a QEMU instance with two NICs, each one connected
2261 #to a TAP device
2262 qemu-system-i386 linux.img \
2263 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2264 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2265 @end example
2267 @example
2268 #launch a QEMU instance with the default network helper to
2269 #connect a TAP device to bridge br0
2270 qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \
2271 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
2272 @end example
2274 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2275 Connect a host TAP network interface to a host bridge device.
2277 Use the network helper @var{helper} to configure the TAP interface and
2278 attach it to the bridge. The default network helper executable is
2279 @file{/path/to/qemu-bridge-helper} and the default bridge
2280 device is @file{br0}.
2282 Examples:
2284 @example
2285 #launch a QEMU instance with the default network helper to
2286 #connect a TAP device to bridge br0
2287 qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
2288 @end example
2290 @example
2291 #launch a QEMU instance with the default network helper to
2292 #connect a TAP device to bridge qemubr0
2293 qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
2294 @end example
2296 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2298 This host network backend can be used to connect the guest's network to
2299 another QEMU virtual machine using a TCP socket connection. If @option{listen}
2300 is specified, QEMU waits for incoming connections on @var{port}
2301 (@var{host} is optional). @option{connect} is used to connect to
2302 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2303 specifies an already opened TCP socket.
2305 Example:
2306 @example
2307 # launch a first QEMU instance
2308 qemu-system-i386 linux.img \
2309 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2310 -netdev socket,id=n1,listen=:1234
2311 # connect the network of this instance to the network of the first instance
2312 qemu-system-i386 linux.img \
2313 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2314 -netdev socket,id=n2,connect=127.0.0.1:1234
2315 @end example
2317 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2319 Configure a socket host network backend to share the guest's network traffic
2320 with another QEMU virtual machines using a UDP multicast socket, effectively
2321 making a bus for every QEMU with same multicast address @var{maddr} and @var{port}.
2322 NOTES:
2323 @enumerate
2324 @item
2325 Several QEMU can be running on different hosts and share same bus (assuming
2326 correct multicast setup for these hosts).
2327 @item
2328 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2329 @url{http://user-mode-linux.sf.net}.
2330 @item
2331 Use @option{fd=h} to specify an already opened UDP multicast socket.
2332 @end enumerate
2334 Example:
2335 @example
2336 # launch one QEMU instance
2337 qemu-system-i386 linux.img \
2338 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2339 -netdev socket,id=n1,mcast=230.0.0.1:1234
2340 # launch another QEMU instance on same "bus"
2341 qemu-system-i386 linux.img \
2342 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2343 -netdev socket,id=n2,mcast=230.0.0.1:1234
2344 # launch yet another QEMU instance on same "bus"
2345 qemu-system-i386 linux.img \
2346 -device e1000,netdev=n3,macaddr=52:54:00:12:34:58 \
2347 -netdev socket,id=n3,mcast=230.0.0.1:1234
2348 @end example
2350 Example (User Mode Linux compat.):
2351 @example
2352 # launch QEMU instance (note mcast address selected is UML's default)
2353 qemu-system-i386 linux.img \
2354 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2355 -netdev socket,id=n1,mcast=239.192.168.1:1102
2356 # launch UML
2357 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2358 @end example
2360 Example (send packets from host's 1.2.3.4):
2361 @example
2362 qemu-system-i386 linux.img \
2363 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2364 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2365 @end example
2367 @item -netdev l2tpv3,id=@var{id},src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}]
2368 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a
2369 popular protocol to transport Ethernet (and other Layer 2) data frames between
2370 two systems. It is present in routers, firewalls and the Linux kernel
2371 (from version 3.3 onwards).
2373 This transport allows a VM to communicate to another VM, router or firewall directly.
2375 @table @option
2376 @item src=@var{srcaddr}
2377 source address (mandatory)
2378 @item dst=@var{dstaddr}
2379 destination address (mandatory)
2380 @item udp
2381 select udp encapsulation (default is ip).
2382 @item srcport=@var{srcport}
2383 source udp port.
2384 @item dstport=@var{dstport}
2385 destination udp port.
2386 @item ipv6
2387 force v6, otherwise defaults to v4.
2388 @item rxcookie=@var{rxcookie}
2389 @itemx txcookie=@var{txcookie}
2390 Cookies are a weak form of security in the l2tpv3 specification.
2391 Their function is mostly to prevent misconfiguration. By default they are 32
2392 bit.
2393 @item cookie64
2394 Set cookie size to 64 bit instead of the default 32
2395 @item counter=off
2396 Force a 'cut-down' L2TPv3 with no counter as in
2397 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2398 @item pincounter=on
2399 Work around broken counter handling in peer. This may also help on
2400 networks which have packet reorder.
2401 @item offset=@var{offset}
2402 Add an extra offset between header and data
2403 @end table
2405 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2406 on the remote Linux host 1.2.3.4:
2407 @example
2408 # Setup tunnel on linux host using raw ip as encapsulation
2409 # on 1.2.3.4
2410 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2411 encap udp udp_sport 16384 udp_dport 16384
2412 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2413 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2414 ifconfig vmtunnel0 mtu 1500
2415 ifconfig vmtunnel0 up
2416 brctl addif br-lan vmtunnel0
2419 # on 4.3.2.1
2420 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2422 qemu-system-i386 linux.img -device e1000,netdev=n1 \
2423 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2425 @end example
2427 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2428 Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and
2429 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2430 and MODE @var{octalmode} to change default ownership and permissions for
2431 communication port. This option is only available if QEMU has been compiled
2432 with vde support enabled.
2434 Example:
2435 @example
2436 # launch vde switch
2437 vde_switch -F -sock /tmp/myswitch
2438 # launch QEMU instance
2439 qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch
2440 @end example
2442 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2444 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2445 be a unix domain socket backed one. The vhost-user uses a specifically defined
2446 protocol to pass vhost ioctl replacement messages to an application on the other
2447 end of the socket. On non-MSIX guests, the feature can be forced with
2448 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2449 be created for multiqueue vhost-user.
2451 Example:
2452 @example
2453 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2454 -numa node,memdev=mem \
2455 -chardev socket,id=chr0,path=/path/to/socket \
2456 -netdev type=vhost-user,id=net0,chardev=chr0 \
2457 -device virtio-net-pci,netdev=net0
2458 @end example
2460 @item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2462 Create a hub port on the emulated hub with ID @var{hubid}.
2464 The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2465 single netdev. @code{-net} and @code{-device} with the parameter @option{vlan}
2466 (deprecated), or @code{-nic hubport} can also be used to connect a
2467 network device or a NIC to a hub. Alternatively, you can also connect the
2468 hubport to another netdev with ID @var{nd} by using the @option{netdev=@var{nd}}
2469 option.
2471 @item -net nic[,vlan=@var{n}][,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2472 @findex -net
2473 Legacy option to configure or create an on-board (or machine default) Network
2474 Interface Card(NIC) and connect it either to the emulated hub port ("vlan")
2475 with number @var{n} (@var{n} = 0 is the default), or to the netdev @var{nd}.
2476 The NIC is an e1000 by default on the PC target. Optionally, the MAC address
2477 can be changed to @var{mac}, the device address set to @var{addr} (PCI cards
2478 only), and a @var{name} can be assigned for use in monitor commands.
2479 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2480 that the card should have; this option currently only affects virtio cards; set
2481 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2482 NIC is created. QEMU can emulate several different models of network card.
2483 Use @code{-net nic,model=help} for a list of available devices for your target.
2485 @item -net user|tap|bridge|socket|l2tpv3|vde[,...][,vlan=@var{n}][,name=@var{name}]
2486 Configure a host network backend (with the options corresponding to the same
2487 @option{-netdev} option) and connect it to the emulated hub ("vlan") with the
2488 number @var{n} (default is number 0). Use @var{name} to specify the name of the
2489 hub port.
2490 ETEXI
2492 STEXI
2493 @end table
2494 ETEXI
2495 DEFHEADING()
2497 DEFHEADING(Character device options:)
2499 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2500 "-chardev help\n"
2501 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2502 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2503 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2504 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2505 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2506 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2507 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2508 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2509 " [,logfile=PATH][,logappend=on|off]\n"
2510 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2511 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2512 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2513 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2514 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2515 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2516 #ifdef _WIN32
2517 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2518 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2519 #else
2520 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2521 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2522 #endif
2523 #ifdef CONFIG_BRLAPI
2524 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2525 #endif
2526 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2527 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2528 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2529 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2530 #endif
2531 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2532 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2533 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2534 #endif
2535 #if defined(CONFIG_SPICE)
2536 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2537 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2538 #endif
2539 , QEMU_ARCH_ALL
2542 STEXI
2544 The general form of a character device option is:
2545 @table @option
2546 @item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2547 @findex -chardev
2548 Backend is one of:
2549 @option{null},
2550 @option{socket},
2551 @option{udp},
2552 @option{msmouse},
2553 @option{vc},
2554 @option{ringbuf},
2555 @option{file},
2556 @option{pipe},
2557 @option{console},
2558 @option{serial},
2559 @option{pty},
2560 @option{stdio},
2561 @option{braille},
2562 @option{tty},
2563 @option{parallel},
2564 @option{parport},
2565 @option{spicevmc},
2566 @option{spiceport}.
2567 The specific backend will determine the applicable options.
2569 Use @code{-chardev help} to print all available chardev backend types.
2571 All devices must have an id, which can be any string up to 127 characters long.
2572 It is used to uniquely identify this device in other command line directives.
2574 A character device may be used in multiplexing mode by multiple front-ends.
2575 Specify @option{mux=on} to enable this mode.
2576 A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2577 backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2578 If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2579 create a multiplexer with your specified ID, and you can then configure multiple
2580 front ends to use that chardev ID for their input/output. Up to four different
2581 front ends can be connected to a single multiplexed chardev. (Without
2582 multiplexing enabled, a chardev can only be used by a single front end.)
2583 For instance you could use this to allow a single stdio chardev to be used by
2584 two serial ports and the QEMU monitor:
2586 @example
2587 -chardev stdio,mux=on,id=char0 \
2588 -mon chardev=char0,mode=readline \
2589 -serial chardev:char0 \
2590 -serial chardev:char0
2591 @end example
2593 You can have more than one multiplexer in a system configuration; for instance
2594 you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2595 multiplexed between the QEMU monitor and a parallel port:
2597 @example
2598 -chardev stdio,mux=on,id=char0 \
2599 -mon chardev=char0,mode=readline \
2600 -parallel chardev:char0 \
2601 -chardev tcp,...,mux=on,id=char1 \
2602 -serial chardev:char1 \
2603 -serial chardev:char1
2604 @end example
2606 When you're using a multiplexed character device, some escape sequences are
2607 interpreted in the input. @xref{mux_keys, Keys in the character backend
2608 multiplexer}.
2610 Note that some other command line options may implicitly create multiplexed
2611 character backends; for instance @option{-serial mon:stdio} creates a
2612 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2613 and @option{-nographic} also multiplexes the console and the monitor to
2614 stdio.
2616 There is currently no support for multiplexing in the other direction
2617 (where a single QEMU front end takes input and output from multiple chardevs).
2619 Every backend supports the @option{logfile} option, which supplies the path
2620 to a file to record all data transmitted via the backend. The @option{logappend}
2621 option controls whether the log file will be truncated or appended to when
2622 opened.
2624 @end table
2626 The available backends are:
2628 @table @option
2629 @item -chardev null,id=@var{id}
2630 A void device. This device will not emit any data, and will drop any data it
2631 receives. The null backend does not take any options.
2633 @item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2635 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2636 unix socket will be created if @option{path} is specified. Behaviour is
2637 undefined if TCP options are specified for a unix socket.
2639 @option{server} specifies that the socket shall be a listening socket.
2641 @option{nowait} specifies that QEMU should not block waiting for a client to
2642 connect to a listening socket.
2644 @option{telnet} specifies that traffic on the socket should interpret telnet
2645 escape sequences.
2647 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2648 the remote end goes away. qemu will delay this many seconds and then attempt
2649 to reconnect. Zero disables reconnecting, and is the default.
2651 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2652 and specifies the id of the TLS credentials to use for the handshake. The
2653 credentials must be previously created with the @option{-object tls-creds}
2654 argument.
2656 TCP and unix socket options are given below:
2658 @table @option
2660 @item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2662 @option{host} for a listening socket specifies the local address to be bound.
2663 For a connecting socket species the remote host to connect to. @option{host} is
2664 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2666 @option{port} for a listening socket specifies the local port to be bound. For a
2667 connecting socket specifies the port on the remote host to connect to.
2668 @option{port} can be given as either a port number or a service name.
2669 @option{port} is required.
2671 @option{to} is only relevant to listening sockets. If it is specified, and
2672 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2673 to and including @option{to} until it succeeds. @option{to} must be specified
2674 as a port number.
2676 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2677 If neither is specified the socket may use either protocol.
2679 @option{nodelay} disables the Nagle algorithm.
2681 @item unix options: path=@var{path}
2683 @option{path} specifies the local path of the unix socket. @option{path} is
2684 required.
2686 @end table
2688 @item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2690 Sends all traffic from the guest to a remote host over UDP.
2692 @option{host} specifies the remote host to connect to. If not specified it
2693 defaults to @code{localhost}.
2695 @option{port} specifies the port on the remote host to connect to. @option{port}
2696 is required.
2698 @option{localaddr} specifies the local address to bind to. If not specified it
2699 defaults to @code{0.0.0.0}.
2701 @option{localport} specifies the local port to bind to. If not specified any
2702 available local port will be used.
2704 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2705 If neither is specified the device may use either protocol.
2707 @item -chardev msmouse,id=@var{id}
2709 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2710 take any options.
2712 @item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2714 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2715 size.
2717 @option{width} and @option{height} specify the width and height respectively of
2718 the console, in pixels.
2720 @option{cols} and @option{rows} specify that the console be sized to fit a text
2721 console with the given dimensions.
2723 @item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2725 Create a ring buffer with fixed size @option{size}.
2726 @var{size} must be a power of two and defaults to @code{64K}.
2728 @item -chardev file,id=@var{id},path=@var{path}
2730 Log all traffic received from the guest to a file.
2732 @option{path} specifies the path of the file to be opened. This file will be
2733 created if it does not already exist, and overwritten if it does. @option{path}
2734 is required.
2736 @item -chardev pipe,id=@var{id},path=@var{path}
2738 Create a two-way connection to the guest. The behaviour differs slightly between
2739 Windows hosts and other hosts:
2741 On Windows, a single duplex pipe will be created at
2742 @file{\\.pipe\@option{path}}.
2744 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2745 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2746 received by the guest. Data written by the guest can be read from
2747 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2748 be present.
2750 @option{path} forms part of the pipe path as described above. @option{path} is
2751 required.
2753 @item -chardev console,id=@var{id}
2755 Send traffic from the guest to QEMU's standard output. @option{console} does not
2756 take any options.
2758 @option{console} is only available on Windows hosts.
2760 @item -chardev serial,id=@var{id},path=@option{path}
2762 Send traffic from the guest to a serial device on the host.
2764 On Unix hosts serial will actually accept any tty device,
2765 not only serial lines.
2767 @option{path} specifies the name of the serial device to open.
2769 @item -chardev pty,id=@var{id}
2771 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2772 not take any options.
2774 @option{pty} is not available on Windows hosts.
2776 @item -chardev stdio,id=@var{id}[,signal=on|off]
2777 Connect to standard input and standard output of the QEMU process.
2779 @option{signal} controls if signals are enabled on the terminal, that includes
2780 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2781 default, use @option{signal=off} to disable it.
2783 @item -chardev braille,id=@var{id}
2785 Connect to a local BrlAPI server. @option{braille} does not take any options.
2787 @item -chardev tty,id=@var{id},path=@var{path}
2789 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2790 DragonFlyBSD hosts. It is an alias for @option{serial}.
2792 @option{path} specifies the path to the tty. @option{path} is required.
2794 @item -chardev parallel,id=@var{id},path=@var{path}
2795 @itemx -chardev parport,id=@var{id},path=@var{path}
2797 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2799 Connect to a local parallel port.
2801 @option{path} specifies the path to the parallel port device. @option{path} is
2802 required.
2804 @item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2806 @option{spicevmc} is only available when spice support is built in.
2808 @option{debug} debug level for spicevmc
2810 @option{name} name of spice channel to connect to
2812 Connect to a spice virtual machine channel, such as vdiport.
2814 @item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2816 @option{spiceport} is only available when spice support is built in.
2818 @option{debug} debug level for spicevmc
2820 @option{name} name of spice port to connect to
2822 Connect to a spice port, allowing a Spice client to handle the traffic
2823 identified by a name (preferably a fqdn).
2824 ETEXI
2826 STEXI
2827 @end table
2828 ETEXI
2829 DEFHEADING()
2831 DEFHEADING(Bluetooth(R) options:)
2832 STEXI
2833 @table @option
2834 ETEXI
2836 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2837 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2838 "-bt hci,host[:id]\n" \
2839 " use host's HCI with the given name\n" \
2840 "-bt hci[,vlan=n]\n" \
2841 " emulate a standard HCI in virtual scatternet 'n'\n" \
2842 "-bt vhci[,vlan=n]\n" \
2843 " add host computer to virtual scatternet 'n' using VHCI\n" \
2844 "-bt device:dev[,vlan=n]\n" \
2845 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2846 QEMU_ARCH_ALL)
2847 STEXI
2848 @item -bt hci[...]
2849 @findex -bt
2850 Defines the function of the corresponding Bluetooth HCI. -bt options
2851 are matched with the HCIs present in the chosen machine type. For
2852 example when emulating a machine with only one HCI built into it, only
2853 the first @code{-bt hci[...]} option is valid and defines the HCI's
2854 logic. The Transport Layer is decided by the machine type. Currently
2855 the machines @code{n800} and @code{n810} have one HCI and all other
2856 machines have none.
2858 @anchor{bt-hcis}
2859 The following three types are recognized:
2861 @table @option
2862 @item -bt hci,null
2863 (default) The corresponding Bluetooth HCI assumes no internal logic
2864 and will not respond to any HCI commands or emit events.
2866 @item -bt hci,host[:@var{id}]
2867 (@code{bluez} only) The corresponding HCI passes commands / events
2868 to / from the physical HCI identified by the name @var{id} (default:
2869 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2870 capable systems like Linux.
2872 @item -bt hci[,vlan=@var{n}]
2873 Add a virtual, standard HCI that will participate in the Bluetooth
2874 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2875 VLANs, devices inside a bluetooth network @var{n} can only communicate
2876 with other devices in the same network (scatternet).
2877 @end table
2879 @item -bt vhci[,vlan=@var{n}]
2880 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2881 to the host bluetooth stack instead of to the emulated target. This
2882 allows the host and target machines to participate in a common scatternet
2883 and communicate. Requires the Linux @code{vhci} driver installed. Can
2884 be used as following:
2886 @example
2887 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2888 @end example
2890 @item -bt device:@var{dev}[,vlan=@var{n}]
2891 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2892 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2893 currently:
2895 @table @option
2896 @item keyboard
2897 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2898 @end table
2899 ETEXI
2901 STEXI
2902 @end table
2903 ETEXI
2904 DEFHEADING()
2906 #ifdef CONFIG_TPM
2907 DEFHEADING(TPM device options:)
2909 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2910 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2911 " use path to provide path to a character device; default is /dev/tpm0\n"
2912 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2913 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2914 "-tpmdev emulator,id=id,chardev=dev\n"
2915 " configure the TPM device using chardev backend\n",
2916 QEMU_ARCH_ALL)
2917 STEXI
2919 The general form of a TPM device option is:
2920 @table @option
2922 @item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2923 @findex -tpmdev
2925 The specific backend type will determine the applicable options.
2926 The @code{-tpmdev} option creates the TPM backend and requires a
2927 @code{-device} option that specifies the TPM frontend interface model.
2929 Use @code{-tpmdev help} to print all available TPM backend types.
2931 @end table
2933 The available backends are:
2935 @table @option
2937 @item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2939 (Linux-host only) Enable access to the host's TPM using the passthrough
2940 driver.
2942 @option{path} specifies the path to the host's TPM device, i.e., on
2943 a Linux host this would be @code{/dev/tpm0}.
2944 @option{path} is optional and by default @code{/dev/tpm0} is used.
2946 @option{cancel-path} specifies the path to the host TPM device's sysfs
2947 entry allowing for cancellation of an ongoing TPM command.
2948 @option{cancel-path} is optional and by default QEMU will search for the
2949 sysfs entry to use.
2951 Some notes about using the host's TPM with the passthrough driver:
2953 The TPM device accessed by the passthrough driver must not be
2954 used by any other application on the host.
2956 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2957 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2958 TPM again and may therefore not show a TPM-specific menu that would
2959 otherwise allow the user to configure the TPM, e.g., allow the user to
2960 enable/disable or activate/deactivate the TPM.
2961 Further, if TPM ownership is released from within a VM then the host's TPM
2962 will get disabled and deactivated. To enable and activate the
2963 TPM again afterwards, the host has to be rebooted and the user is
2964 required to enter the firmware's menu to enable and activate the TPM.
2965 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2967 To create a passthrough TPM use the following two options:
2968 @example
2969 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2970 @end example
2971 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2972 @code{tpmdev=tpm0} in the device option.
2974 @item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2976 (Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2977 chardev backend.
2979 @option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2981 To create a TPM emulator backend device with chardev socket backend:
2982 @example
2984 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2986 @end example
2988 ETEXI
2990 STEXI
2991 @end table
2992 ETEXI
2993 DEFHEADING()
2995 #endif
2997 DEFHEADING(Linux/Multiboot boot specific:)
2998 STEXI
3000 When using these options, you can use a given Linux or Multiboot
3001 kernel without installing it in the disk image. It can be useful
3002 for easier testing of various kernels.
3004 @table @option
3005 ETEXI
3007 DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
3008 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
3009 STEXI
3010 @item -kernel @var{bzImage}
3011 @findex -kernel
3012 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
3013 or in multiboot format.
3014 ETEXI
3016 DEF("append", HAS_ARG, QEMU_OPTION_append, \
3017 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
3018 STEXI
3019 @item -append @var{cmdline}
3020 @findex -append
3021 Use @var{cmdline} as kernel command line
3022 ETEXI
3024 DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
3025 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
3026 STEXI
3027 @item -initrd @var{file}
3028 @findex -initrd
3029 Use @var{file} as initial ram disk.
3031 @item -initrd "@var{file1} arg=foo,@var{file2}"
3033 This syntax is only available with multiboot.
3035 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3036 first module.
3037 ETEXI
3039 DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
3040 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
3041 STEXI
3042 @item -dtb @var{file}
3043 @findex -dtb
3044 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3045 on boot.
3046 ETEXI
3048 STEXI
3049 @end table
3050 ETEXI
3051 DEFHEADING()
3053 DEFHEADING(Debug/Expert options:)
3054 STEXI
3055 @table @option
3056 ETEXI
3058 DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3059 "-fw_cfg [name=]<name>,file=<file>\n"
3060 " add named fw_cfg entry with contents from file\n"
3061 "-fw_cfg [name=]<name>,string=<str>\n"
3062 " add named fw_cfg entry with contents from string\n",
3063 QEMU_ARCH_ALL)
3064 STEXI
3066 @item -fw_cfg [name=]@var{name},file=@var{file}
3067 @findex -fw_cfg
3068 Add named fw_cfg entry with contents from file @var{file}.
3070 @item -fw_cfg [name=]@var{name},string=@var{str}
3071 Add named fw_cfg entry with contents from string @var{str}.
3073 The terminating NUL character of the contents of @var{str} will not be
3074 included as part of the fw_cfg item data. To insert contents with
3075 embedded NUL characters, you have to use the @var{file} parameter.
3077 The fw_cfg entries are passed by QEMU through to the guest.
3079 Example:
3080 @example
3081 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3082 @end example
3083 creates an fw_cfg entry named opt/com.mycompany/blob with contents
3084 from ./my_blob.bin.
3086 ETEXI
3088 DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3089 "-serial dev redirect the serial port to char device 'dev'\n",
3090 QEMU_ARCH_ALL)
3091 STEXI
3092 @item -serial @var{dev}
3093 @findex -serial
3094 Redirect the virtual serial port to host character device
3095 @var{dev}. The default device is @code{vc} in graphical mode and
3096 @code{stdio} in non graphical mode.
3098 This option can be used several times to simulate up to 4 serial
3099 ports.
3101 Use @code{-serial none} to disable all serial ports.
3103 Available character devices are:
3104 @table @option
3105 @item vc[:@var{W}x@var{H}]
3106 Virtual console. Optionally, a width and height can be given in pixel with
3107 @example
3108 vc:800x600
3109 @end example
3110 It is also possible to specify width or height in characters:
3111 @example
3112 vc:80Cx24C
3113 @end example
3114 @item pty
3115 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3116 @item none
3117 No device is allocated.
3118 @item null
3119 void device
3120 @item chardev:@var{id}
3121 Use a named character device defined with the @code{-chardev} option.
3122 @item /dev/XXX
3123 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3124 parameters are set according to the emulated ones.
3125 @item /dev/parport@var{N}
3126 [Linux only, parallel port only] Use host parallel port
3127 @var{N}. Currently SPP and EPP parallel port features can be used.
3128 @item file:@var{filename}
3129 Write output to @var{filename}. No character can be read.
3130 @item stdio
3131 [Unix only] standard input/output
3132 @item pipe:@var{filename}
3133 name pipe @var{filename}
3134 @item COM@var{n}
3135 [Windows only] Use host serial port @var{n}
3136 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3137 This implements UDP Net Console.
3138 When @var{remote_host} or @var{src_ip} are not specified
3139 they default to @code{0.0.0.0}.
3140 When not using a specified @var{src_port} a random port is automatically chosen.
3142 If you just want a simple readonly console you can use @code{netcat} or
3143 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3144 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3145 will appear in the netconsole session.
3147 If you plan to send characters back via netconsole or you want to stop
3148 and start QEMU a lot of times, you should have QEMU use the same
3149 source port each time by using something like @code{-serial
3150 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3151 version of netcat which can listen to a TCP port and send and receive
3152 characters via udp. If you have a patched version of netcat which
3153 activates telnet remote echo and single char transfer, then you can
3154 use the following options to set up a netcat redirector to allow
3155 telnet on port 5555 to access the QEMU port.
3156 @table @code
3157 @item QEMU Options:
3158 -serial udp::4555@@:4556
3159 @item netcat options:
3160 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3161 @item telnet options:
3162 localhost 5555
3163 @end table
3165 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3166 The TCP Net Console has two modes of operation. It can send the serial
3167 I/O to a location or wait for a connection from a location. By default
3168 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3169 the @var{server} option QEMU will wait for a client socket application
3170 to connect to the port before continuing, unless the @code{nowait}
3171 option was specified. The @code{nodelay} option disables the Nagle buffering
3172 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3173 set, if the connection goes down it will attempt to reconnect at the
3174 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3175 one TCP connection at a time is accepted. You can use @code{telnet} to
3176 connect to the corresponding character device.
3177 @table @code
3178 @item Example to send tcp console to 192.168.0.2 port 4444
3179 -serial tcp:192.168.0.2:4444
3180 @item Example to listen and wait on port 4444 for connection
3181 -serial tcp::4444,server
3182 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3183 -serial tcp:192.168.0.100:4444,server,nowait
3184 @end table
3186 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3187 The telnet protocol is used instead of raw tcp sockets. The options
3188 work the same as if you had specified @code{-serial tcp}. The
3189 difference is that the port acts like a telnet server or client using
3190 telnet option negotiation. This will also allow you to send the
3191 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3192 sequence. Typically in unix telnet you do it with Control-] and then
3193 type "send break" followed by pressing the enter key.
3195 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3196 A unix domain socket is used instead of a tcp socket. The option works the
3197 same as if you had specified @code{-serial tcp} except the unix domain socket
3198 @var{path} is used for connections.
3200 @item mon:@var{dev_string}
3201 This is a special option to allow the monitor to be multiplexed onto
3202 another serial port. The monitor is accessed with key sequence of
3203 @key{Control-a} and then pressing @key{c}.
3204 @var{dev_string} should be any one of the serial devices specified
3205 above. An example to multiplex the monitor onto a telnet server
3206 listening on port 4444 would be:
3207 @table @code
3208 @item -serial mon:telnet::4444,server,nowait
3209 @end table
3210 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3211 QEMU any more but will be passed to the guest instead.
3213 @item braille
3214 Braille device. This will use BrlAPI to display the braille output on a real
3215 or fake device.
3217 @item msmouse
3218 Three button serial mouse. Configure the guest to use Microsoft protocol.
3219 @end table
3220 ETEXI
3222 DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3223 "-parallel dev redirect the parallel port to char device 'dev'\n",
3224 QEMU_ARCH_ALL)
3225 STEXI
3226 @item -parallel @var{dev}
3227 @findex -parallel
3228 Redirect the virtual parallel port to host device @var{dev} (same
3229 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3230 be used to use hardware devices connected on the corresponding host
3231 parallel port.
3233 This option can be used several times to simulate up to 3 parallel
3234 ports.
3236 Use @code{-parallel none} to disable all parallel ports.
3237 ETEXI
3239 DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3240 "-monitor dev redirect the monitor to char device 'dev'\n",
3241 QEMU_ARCH_ALL)
3242 STEXI
3243 @item -monitor @var{dev}
3244 @findex -monitor
3245 Redirect the monitor to host device @var{dev} (same devices as the
3246 serial port).
3247 The default device is @code{vc} in graphical mode and @code{stdio} in
3248 non graphical mode.
3249 Use @code{-monitor none} to disable the default monitor.
3250 ETEXI
3251 DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3252 "-qmp dev like -monitor but opens in 'control' mode\n",
3253 QEMU_ARCH_ALL)
3254 STEXI
3255 @item -qmp @var{dev}
3256 @findex -qmp
3257 Like -monitor but opens in 'control' mode.
3258 ETEXI
3259 DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3260 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3261 QEMU_ARCH_ALL)
3262 STEXI
3263 @item -qmp-pretty @var{dev}
3264 @findex -qmp-pretty
3265 Like -qmp but uses pretty JSON formatting.
3266 ETEXI
3268 DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3269 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3270 STEXI
3271 @item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3272 @findex -mon
3273 Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3274 easing human reading and debugging.
3275 ETEXI
3277 DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3278 "-debugcon dev redirect the debug console to char device 'dev'\n",
3279 QEMU_ARCH_ALL)
3280 STEXI
3281 @item -debugcon @var{dev}
3282 @findex -debugcon
3283 Redirect the debug console to host device @var{dev} (same devices as the
3284 serial port). The debug console is an I/O port which is typically port
3285 0xe9; writing to that I/O port sends output to this device.
3286 The default device is @code{vc} in graphical mode and @code{stdio} in
3287 non graphical mode.
3288 ETEXI
3290 DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3291 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
3292 STEXI
3293 @item -pidfile @var{file}
3294 @findex -pidfile
3295 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3296 from a script.
3297 ETEXI
3299 DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3300 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
3301 STEXI
3302 @item -singlestep
3303 @findex -singlestep
3304 Run the emulation in single step mode.
3305 ETEXI
3307 DEF("S", 0, QEMU_OPTION_S, \
3308 "-S freeze CPU at startup (use 'c' to start execution)\n",
3309 QEMU_ARCH_ALL)
3310 STEXI
3311 @item -S
3312 @findex -S
3313 Do not start CPU at startup (you must type 'c' in the monitor).
3314 ETEXI
3316 DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3317 "-realtime [mlock=on|off]\n"
3318 " run qemu with realtime features\n"
3319 " mlock=on|off controls mlock support (default: on)\n",
3320 QEMU_ARCH_ALL)
3321 STEXI
3322 @item -realtime mlock=on|off
3323 @findex -realtime
3324 Run qemu with realtime features.
3325 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3326 (enabled by default).
3327 ETEXI
3329 DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3330 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3331 STEXI
3332 @item -gdb @var{dev}
3333 @findex -gdb
3334 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3335 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3336 stdio are reasonable use case. The latter is allowing to start QEMU from
3337 within gdb and establish the connection via a pipe:
3338 @example
3339 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3340 @end example
3341 ETEXI
3343 DEF("s", 0, QEMU_OPTION_s, \
3344 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3345 QEMU_ARCH_ALL)
3346 STEXI
3347 @item -s
3348 @findex -s
3349 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3350 (@pxref{gdb_usage}).
3351 ETEXI
3353 DEF("d", HAS_ARG, QEMU_OPTION_d, \
3354 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
3355 QEMU_ARCH_ALL)
3356 STEXI
3357 @item -d @var{item1}[,...]
3358 @findex -d
3359 Enable logging of specified items. Use '-d help' for a list of log items.
3360 ETEXI
3362 DEF("D", HAS_ARG, QEMU_OPTION_D, \
3363 "-D logfile output log to logfile (default stderr)\n",
3364 QEMU_ARCH_ALL)
3365 STEXI
3366 @item -D @var{logfile}
3367 @findex -D
3368 Output log in @var{logfile} instead of to stderr
3369 ETEXI
3371 DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3372 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3373 QEMU_ARCH_ALL)
3374 STEXI
3375 @item -dfilter @var{range1}[,...]
3376 @findex -dfilter
3377 Filter debug output to that relevant to a range of target addresses. The filter
3378 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3379 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3380 addresses and sizes required. For example:
3381 @example
3382 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3383 @end example
3384 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3385 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3386 block starting at 0xffffffc00005f000.
3387 ETEXI
3389 DEF("L", HAS_ARG, QEMU_OPTION_L, \
3390 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
3391 QEMU_ARCH_ALL)
3392 STEXI
3393 @item -L @var{path}
3394 @findex -L
3395 Set the directory for the BIOS, VGA BIOS and keymaps.
3397 To list all the data directories, use @code{-L help}.
3398 ETEXI
3400 DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3401 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
3402 STEXI
3403 @item -bios @var{file}
3404 @findex -bios
3405 Set the filename for the BIOS.
3406 ETEXI
3408 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3409 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3410 STEXI
3411 @item -enable-kvm
3412 @findex -enable-kvm
3413 Enable KVM full virtualization support. This option is only available
3414 if KVM support is enabled when compiling.
3415 ETEXI
3417 DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3418 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386)
3419 STEXI
3420 @item -enable-hax
3421 @findex -enable-hax
3422 Enable HAX (Hardware-based Acceleration eXecution) support. This option
3423 is only available if HAX support is enabled when compiling. HAX is only
3424 applicable to MAC and Windows platform, and thus does not conflict with
3425 KVM.
3426 ETEXI
3428 DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3429 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
3430 DEF("xen-create", 0, QEMU_OPTION_xen_create,
3431 "-xen-create create domain using xen hypercalls, bypassing xend\n"
3432 " warning: should not be used when xend is in use\n",
3433 QEMU_ARCH_ALL)
3434 DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3435 "-xen-attach attach to existing xen domain\n"
3436 " xend will use this when starting QEMU\n",
3437 QEMU_ARCH_ALL)
3438 DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3439 "-xen-domid-restrict restrict set of available xen operations\n"
3440 " to specified domain id. (Does not affect\n"
3441 " xenpv machine type).\n",
3442 QEMU_ARCH_ALL)
3443 STEXI
3444 @item -xen-domid @var{id}
3445 @findex -xen-domid
3446 Specify xen guest domain @var{id} (XEN only).
3447 @item -xen-create
3448 @findex -xen-create
3449 Create domain using xen hypercalls, bypassing xend.
3450 Warning: should not be used when xend is in use (XEN only).
3451 @item -xen-attach
3452 @findex -xen-attach
3453 Attach to existing xen domain.
3454 xend will use this when starting QEMU (XEN only).
3455 @findex -xen-domid-restrict
3456 Restrict set of available xen operations to specified domain id (XEN only).
3457 ETEXI
3459 DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3460 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
3461 STEXI
3462 @item -no-reboot
3463 @findex -no-reboot
3464 Exit instead of rebooting.
3465 ETEXI
3467 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3468 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
3469 STEXI
3470 @item -no-shutdown
3471 @findex -no-shutdown
3472 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3473 This allows for instance switching to monitor to commit changes to the
3474 disk image.
3475 ETEXI
3477 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3478 "-loadvm [tag|id]\n" \
3479 " start right away with a saved state (loadvm in monitor)\n",
3480 QEMU_ARCH_ALL)
3481 STEXI
3482 @item -loadvm @var{file}
3483 @findex -loadvm
3484 Start right away with a saved state (@code{loadvm} in monitor)
3485 ETEXI
3487 #ifndef _WIN32
3488 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3489 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3490 #endif
3491 STEXI
3492 @item -daemonize
3493 @findex -daemonize
3494 Daemonize the QEMU process after initialization. QEMU will not detach from
3495 standard IO until it is ready to receive connections on any of its devices.
3496 This option is a useful way for external programs to launch QEMU without having
3497 to cope with initialization race conditions.
3498 ETEXI
3500 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3501 "-option-rom rom load a file, rom, into the option ROM space\n",
3502 QEMU_ARCH_ALL)
3503 STEXI
3504 @item -option-rom @var{file}
3505 @findex -option-rom
3506 Load the contents of @var{file} as an option ROM.
3507 This option is useful to load things like EtherBoot.
3508 ETEXI
3510 HXCOMM Silently ignored for compatibility
3511 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3513 HXCOMM Options deprecated by -rtc
3514 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3515 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3517 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3518 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3519 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3520 QEMU_ARCH_ALL)
3522 STEXI
3524 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3525 @findex -rtc
3526 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3527 UTC or local time, respectively. @code{localtime} is required for correct date in
3528 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3529 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3531 By default the RTC is driven by the host system time. This allows using of the
3532 RTC as accurate reference clock inside the guest, specifically if the host
3533 time is smoothly following an accurate external reference clock, e.g. via NTP.
3534 If you want to isolate the guest time from the host, you can set @option{clock}
3535 to @code{rt} instead. To even prevent it from progressing during suspension,
3536 you can set it to @code{vm}.
3538 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3539 specifically with Windows' ACPI HAL. This option will try to figure out how
3540 many timer interrupts were not processed by the Windows guest and will
3541 re-inject them.
3542 ETEXI
3544 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3545 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3546 " enable virtual instruction counter with 2^N clock ticks per\n" \
3547 " instruction, enable aligning the host and virtual clocks\n" \
3548 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3549 STEXI
3550 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3551 @findex -icount
3552 Enable virtual instruction counter. The virtual cpu will execute one
3553 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3554 then the virtual cpu speed will be automatically adjusted to keep virtual
3555 time within a few seconds of real time.
3557 When the virtual cpu is sleeping, the virtual time will advance at default
3558 speed unless @option{sleep=on|off} is specified.
3559 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3560 instantly whenever the virtual cpu goes to sleep mode and will not advance
3561 if no timer is enabled. This behavior give deterministic execution times from
3562 the guest point of view.
3564 Note that while this option can give deterministic behavior, it does not
3565 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3566 order cores with complex cache hierarchies. The number of instructions
3567 executed often has little or no correlation with actual performance.
3569 @option{align=on} will activate the delay algorithm which will try
3570 to synchronise the host clock and the virtual clock. The goal is to
3571 have a guest running at the real frequency imposed by the shift option.
3572 Whenever the guest clock is behind the host clock and if
3573 @option{align=on} is specified then we print a message to the user
3574 to inform about the delay.
3575 Currently this option does not work when @option{shift} is @code{auto}.
3576 Note: The sync algorithm will work for those shift values for which
3577 the guest clock runs ahead of the host clock. Typically this happens
3578 when the shift value is high (how high depends on the host machine).
3580 When @option{rr} option is specified deterministic record/replay is enabled.
3581 Replay log is written into @var{filename} file in record mode and
3582 read from this file in replay mode.
3584 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3585 at the start of execution recording. In replay mode this option is used
3586 to load the initial VM state.
3587 ETEXI
3589 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3590 "-watchdog model\n" \
3591 " enable virtual hardware watchdog [default=none]\n",
3592 QEMU_ARCH_ALL)
3593 STEXI
3594 @item -watchdog @var{model}
3595 @findex -watchdog
3596 Create a virtual hardware watchdog device. Once enabled (by a guest
3597 action), the watchdog must be periodically polled by an agent inside
3598 the guest or else the guest will be restarted. Choose a model for
3599 which your guest has drivers.
3601 The @var{model} is the model of hardware watchdog to emulate. Use
3602 @code{-watchdog help} to list available hardware models. Only one
3603 watchdog can be enabled for a guest.
3605 The following models may be available:
3606 @table @option
3607 @item ib700
3608 iBASE 700 is a very simple ISA watchdog with a single timer.
3609 @item i6300esb
3610 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3611 dual-timer watchdog.
3612 @item diag288
3613 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3614 (currently KVM only).
3615 @end table
3616 ETEXI
3618 DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3619 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3620 " action when watchdog fires [default=reset]\n",
3621 QEMU_ARCH_ALL)
3622 STEXI
3623 @item -watchdog-action @var{action}
3624 @findex -watchdog-action
3626 The @var{action} controls what QEMU will do when the watchdog timer
3627 expires.
3628 The default is
3629 @code{reset} (forcefully reset the guest).
3630 Other possible actions are:
3631 @code{shutdown} (attempt to gracefully shutdown the guest),
3632 @code{poweroff} (forcefully poweroff the guest),
3633 @code{inject-nmi} (inject a NMI into the guest),
3634 @code{pause} (pause the guest),
3635 @code{debug} (print a debug message and continue), or
3636 @code{none} (do nothing).
3638 Note that the @code{shutdown} action requires that the guest responds
3639 to ACPI signals, which it may not be able to do in the sort of
3640 situations where the watchdog would have expired, and thus
3641 @code{-watchdog-action shutdown} is not recommended for production use.
3643 Examples:
3645 @table @code
3646 @item -watchdog i6300esb -watchdog-action pause
3647 @itemx -watchdog ib700
3648 @end table
3649 ETEXI
3651 DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3652 "-echr chr set terminal escape character instead of ctrl-a\n",
3653 QEMU_ARCH_ALL)
3654 STEXI
3656 @item -echr @var{numeric_ascii_value}
3657 @findex -echr
3658 Change the escape character used for switching to the monitor when using
3659 monitor and serial sharing. The default is @code{0x01} when using the
3660 @code{-nographic} option. @code{0x01} is equal to pressing
3661 @code{Control-a}. You can select a different character from the ascii
3662 control keys where 1 through 26 map to Control-a through Control-z. For
3663 instance you could use the either of the following to change the escape
3664 character to Control-t.
3665 @table @code
3666 @item -echr 0x14
3667 @itemx -echr 20
3668 @end table
3669 ETEXI
3671 DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3672 "-virtioconsole c\n" \
3673 " set virtio console\n", QEMU_ARCH_ALL)
3674 STEXI
3675 @item -virtioconsole @var{c}
3676 @findex -virtioconsole
3677 Set virtio console.
3679 This option is maintained for backward compatibility.
3681 Please use @code{-device virtconsole} for the new way of invocation.
3682 ETEXI
3684 DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3685 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
3686 STEXI
3687 @item -show-cursor
3688 @findex -show-cursor
3689 Show cursor.
3690 ETEXI
3692 DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3693 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
3694 STEXI
3695 @item -tb-size @var{n}
3696 @findex -tb-size
3697 Set TB size.
3698 ETEXI
3700 DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3701 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3702 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3703 "-incoming unix:socketpath\n" \
3704 " prepare for incoming migration, listen on\n" \
3705 " specified protocol and socket address\n" \
3706 "-incoming fd:fd\n" \
3707 "-incoming exec:cmdline\n" \
3708 " accept incoming migration on given file descriptor\n" \
3709 " or from given external command\n" \
3710 "-incoming defer\n" \
3711 " wait for the URI to be specified via migrate_incoming\n",
3712 QEMU_ARCH_ALL)
3713 STEXI
3714 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3715 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3716 @findex -incoming
3717 Prepare for incoming migration, listen on a given tcp port.
3719 @item -incoming unix:@var{socketpath}
3720 Prepare for incoming migration, listen on a given unix socket.
3722 @item -incoming fd:@var{fd}
3723 Accept incoming migration from a given filedescriptor.
3725 @item -incoming exec:@var{cmdline}
3726 Accept incoming migration as an output from specified external command.
3728 @item -incoming defer
3729 Wait for the URI to be specified via migrate_incoming. The monitor can
3730 be used to change settings (such as migration parameters) prior to issuing
3731 the migrate_incoming to allow the migration to begin.
3732 ETEXI
3734 DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3735 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
3736 STEXI
3737 @item -only-migratable
3738 @findex -only-migratable
3739 Only allow migratable devices. Devices will not be allowed to enter an
3740 unmigratable state.
3741 ETEXI
3743 DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3744 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
3745 STEXI
3746 @item -nodefaults
3747 @findex -nodefaults
3748 Don't create default devices. Normally, QEMU sets the default devices like serial
3749 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3750 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3751 default devices.
3752 ETEXI
3754 #ifndef _WIN32
3755 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3756 "-chroot dir chroot to dir just before starting the VM\n",
3757 QEMU_ARCH_ALL)
3758 #endif
3759 STEXI
3760 @item -chroot @var{dir}
3761 @findex -chroot
3762 Immediately before starting guest execution, chroot to the specified
3763 directory. Especially useful in combination with -runas.
3764 ETEXI
3766 #ifndef _WIN32
3767 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3768 "-runas user change to user id user just before starting the VM\n",
3769 QEMU_ARCH_ALL)
3770 #endif
3771 STEXI
3772 @item -runas @var{user}
3773 @findex -runas
3774 Immediately before starting guest execution, drop root privileges, switching
3775 to the specified user.
3776 ETEXI
3778 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3779 "-prom-env variable=value\n"
3780 " set OpenBIOS nvram variables\n",
3781 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3782 STEXI
3783 @item -prom-env @var{variable}=@var{value}
3784 @findex -prom-env
3785 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3786 ETEXI
3787 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3788 "-semihosting semihosting mode\n",
3789 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3790 QEMU_ARCH_MIPS)
3791 STEXI
3792 @item -semihosting
3793 @findex -semihosting
3794 Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3795 ETEXI
3796 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3797 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3798 " semihosting configuration\n",
3799 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3800 QEMU_ARCH_MIPS)
3801 STEXI
3802 @item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3803 @findex -semihosting-config
3804 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3805 @table @option
3806 @item target=@code{native|gdb|auto}
3807 Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3808 or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3809 during debug sessions and @code{native} otherwise.
3810 @item arg=@var{str1},arg=@var{str2},...
3811 Allows the user to pass input arguments, and can be used multiple times to build
3812 up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3813 command line is still supported for backward compatibility. If both the
3814 @code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3815 specified, the former is passed to semihosting as it always takes precedence.
3816 @end table
3817 ETEXI
3818 DEF("old-param", 0, QEMU_OPTION_old_param,
3819 "-old-param old param mode\n", QEMU_ARCH_ARM)
3820 STEXI
3821 @item -old-param
3822 @findex -old-param (ARM)
3823 Old param mode (ARM only).
3824 ETEXI
3826 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3827 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3828 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3829 " Enable seccomp mode 2 system call filter (default 'off').\n" \
3830 " use 'obsolete' to allow obsolete system calls that are provided\n" \
3831 " by the kernel, but typically no longer used by modern\n" \
3832 " C library implementations.\n" \
3833 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3834 " its privileges by blacklisting all set*uid|gid system calls.\n" \
3835 " The value 'children' will deny set*uid|gid system calls for\n" \
3836 " main QEMU process but will allow forks and execves to run unprivileged\n" \
3837 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3838 " blacklisting *fork and execve\n" \
3839 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
3840 QEMU_ARCH_ALL)
3841 STEXI
3842 @item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3843 @findex -sandbox
3844 Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3845 disable it. The default is 'off'.
3846 @table @option
3847 @item obsolete=@var{string}
3848 Enable Obsolete system calls
3849 @item elevateprivileges=@var{string}
3850 Disable set*uid|gid system calls
3851 @item spawn=@var{string}
3852 Disable *fork and execve
3853 @item resourcecontrol=@var{string}
3854 Disable process affinity and schedular priority
3855 @end table
3856 ETEXI
3858 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3859 "-readconfig <file>\n", QEMU_ARCH_ALL)
3860 STEXI
3861 @item -readconfig @var{file}
3862 @findex -readconfig
3863 Read device configuration from @var{file}. This approach is useful when you want to spawn
3864 QEMU process with many command line options but you don't want to exceed the command line
3865 character limit.
3866 ETEXI
3867 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3868 "-writeconfig <file>\n"
3869 " read/write config file\n", QEMU_ARCH_ALL)
3870 STEXI
3871 @item -writeconfig @var{file}
3872 @findex -writeconfig
3873 Write device configuration to @var{file}. The @var{file} can be either filename to save
3874 command line and device configuration into file or dash @code{-}) character to print the
3875 output to stdout. This can be later used as input file for @code{-readconfig} option.
3876 ETEXI
3877 HXCOMM Deprecated, same as -no-user-config
3878 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
3879 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3880 "-no-user-config\n"
3881 " do not load default user-provided config files at startup\n",
3882 QEMU_ARCH_ALL)
3883 STEXI
3884 @item -no-user-config
3885 @findex -no-user-config
3886 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3887 config files on @var{sysconfdir}.
3888 ETEXI
3889 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3890 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3891 " specify tracing options\n",
3892 QEMU_ARCH_ALL)
3893 STEXI
3894 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3895 HXCOMM HX does not support conditional compilation of text.
3896 @item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3897 @findex -trace
3898 @include qemu-option-trace.texi
3899 ETEXI
3901 HXCOMM Internal use
3902 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3903 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3905 #ifdef __linux__
3906 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3907 "-enable-fips enable FIPS 140-2 compliance\n",
3908 QEMU_ARCH_ALL)
3909 #endif
3910 STEXI
3911 @item -enable-fips
3912 @findex -enable-fips
3913 Enable FIPS 140-2 compliance mode.
3914 ETEXI
3916 HXCOMM Deprecated by -machine accel=tcg property
3917 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3919 HXCOMM Deprecated by kvm-pit driver properties
3920 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3921 "", QEMU_ARCH_I386)
3923 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3924 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3926 HXCOMM Deprecated (ignored)
3927 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3929 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3930 "-msg timestamp[=on|off]\n"
3931 " change the format of messages\n"
3932 " on|off controls leading timestamps (default:on)\n",
3933 QEMU_ARCH_ALL)
3934 STEXI
3935 @item -msg timestamp[=on|off]
3936 @findex -msg
3937 prepend a timestamp to each log message.(default:on)
3938 ETEXI
3940 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3941 "-dump-vmstate <file>\n"
3942 " Output vmstate information in JSON format to file.\n"
3943 " Use the scripts/vmstate-static-checker.py file to\n"
3944 " check for possible regressions in migration code\n"
3945 " by comparing two such vmstate dumps.\n",
3946 QEMU_ARCH_ALL)
3947 STEXI
3948 @item -dump-vmstate @var{file}
3949 @findex -dump-vmstate
3950 Dump json-encoded vmstate information for current machine type to file
3951 in @var{file}
3952 ETEXI
3954 STEXI
3955 @end table
3956 ETEXI
3957 DEFHEADING()
3959 DEFHEADING(Generic object creation:)
3960 STEXI
3961 @table @option
3962 ETEXI
3964 DEF("object", HAS_ARG, QEMU_OPTION_object,
3965 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3966 " create a new object of type TYPENAME setting properties\n"
3967 " in the order they are specified. Note that the 'id'\n"
3968 " property must be set. These objects are placed in the\n"
3969 " '/objects' path.\n",
3970 QEMU_ARCH_ALL)
3971 STEXI
3972 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3973 @findex -object
3974 Create a new object of type @var{typename} setting properties
3975 in the order they are specified. Note that the 'id'
3976 property must be set. These objects are placed in the
3977 '/objects' path.
3979 @table @option
3981 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},align=@var{align}
3983 Creates a memory file backend object, which can be used to back
3984 the guest RAM with huge pages.
3986 The @option{id} parameter is a unique ID that will be used to reference this
3987 memory region when configuring the @option{-numa} argument.
3989 The @option{size} option provides the size of the memory region, and accepts
3990 common suffixes, eg @option{500M}.
3992 The @option{mem-path} provides the path to either a shared memory or huge page
3993 filesystem mount.
3995 The @option{share} boolean option determines whether the memory
3996 region is marked as private to QEMU, or shared. The latter allows
3997 a co-operating external process to access the QEMU memory region.
3999 The @option{share} is also required for pvrdma devices due to
4000 limitations in the RDMA API provided by Linux.
4002 Setting share=on might affect the ability to configure NUMA
4003 bindings for the memory backend under some circumstances, see
4004 Documentation/vm/numa_memory_policy.txt on the Linux kernel
4005 source tree for additional details.
4007 Setting the @option{discard-data} boolean option to @var{on}
4008 indicates that file contents can be destroyed when QEMU exits,
4009 to avoid unnecessarily flushing data to the backing file. Note
4010 that @option{discard-data} is only an optimization, and QEMU
4011 might not discard file contents if it aborts unexpectedly or is
4012 terminated using SIGKILL.
4014 The @option{merge} boolean option enables memory merge, also known as
4015 MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
4016 memory deduplication.
4018 Setting the @option{dump} boolean option to @var{off} excludes the memory from
4019 core dumps. This feature is also known as MADV_DONTDUMP.
4021 The @option{prealloc} boolean option enables memory preallocation.
4023 The @option{host-nodes} option binds the memory range to a list of NUMA host
4024 nodes.
4026 The @option{policy} option sets the NUMA policy to one of the following values:
4028 @table @option
4029 @item @var{default}
4030 default host policy
4032 @item @var{preferred}
4033 prefer the given host node list for allocation
4035 @item @var{bind}
4036 restrict memory allocation to the given host node list
4038 @item @var{interleave}
4039 interleave memory allocations across the given host node list
4040 @end table
4042 The @option{align} option specifies the base address alignment when
4043 QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
4044 @option{2M}. Some backend store specified by @option{mem-path}
4045 requires an alignment different than the default one used by QEMU, eg
4046 the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4047 such cases, users can specify the required alignment via this option.
4049 @item -object memory-backend-ram,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave}
4051 Creates a memory backend object, which can be used to back the guest RAM.
4052 Memory backend objects offer more control than the @option{-m} option that is
4053 traditionally used to define guest RAM. Please refer to
4054 @option{memory-backend-file} for a description of the options.
4056 @item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},seal=@var{on|off},hugetlb=@var{on|off},hugetlbsize=@var{size}
4058 Creates an anonymous memory file backend object, which allows QEMU to
4059 share the memory with an external process (e.g. when using
4060 vhost-user). The memory is allocated with memfd and optional
4061 sealing. (Linux only)
4063 The @option{seal} option creates a sealed-file, that will block
4064 further resizing the memory ('on' by default).
4066 The @option{hugetlb} option specify the file to be created resides in
4067 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with
4068 the @option{hugetlb} option, the @option{hugetlbsize} option specify
4069 the hugetlb page size on systems that support multiple hugetlb page
4070 sizes (it must be a power of 2 value supported by the system).
4072 In some versions of Linux, the @option{hugetlb} option is incompatible
4073 with the @option{seal} option (requires at least Linux 4.16).
4075 Please refer to @option{memory-backend-file} for a description of the
4076 other options.
4078 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
4080 Creates a random number generator backend which obtains entropy from
4081 a device on the host. The @option{id} parameter is a unique ID that
4082 will be used to reference this entropy backend from the @option{virtio-rng}
4083 device. The @option{filename} parameter specifies which file to obtain
4084 entropy from and if omitted defaults to @option{/dev/random}.
4086 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4088 Creates a random number generator backend which obtains entropy from
4089 an external daemon running on the host. The @option{id} parameter is
4090 a unique ID that will be used to reference this entropy backend from
4091 the @option{virtio-rng} device. The @option{chardev} parameter is
4092 the unique ID of a character device backend that provides the connection
4093 to the RNG daemon.
4095 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4097 Creates a TLS anonymous credentials object, which can be used to provide
4098 TLS support on network backends. The @option{id} parameter is a unique
4099 ID which network backends will use to access the credentials. The
4100 @option{endpoint} is either @option{server} or @option{client} depending
4101 on whether the QEMU network backend that uses the credentials will be
4102 acting as a client or as a server. If @option{verify-peer} is enabled
4103 (the default) then once the handshake is completed, the peer credentials
4104 will be verified, though this is a no-op for anonymous credentials.
4106 The @var{dir} parameter tells QEMU where to find the credential
4107 files. For server endpoints, this directory may contain a file
4108 @var{dh-params.pem} providing diffie-hellman parameters to use
4109 for the TLS server. If the file is missing, QEMU will generate
4110 a set of DH parameters at startup. This is a computationally
4111 expensive operation that consumes random pool entropy, so it is
4112 recommended that a persistent set of parameters be generated
4113 upfront and saved.
4115 @item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},priority=@var{priority},verify-peer=@var{on|off},passwordid=@var{id}
4117 Creates a TLS anonymous credentials object, which can be used to provide
4118 TLS support on network backends. The @option{id} parameter is a unique
4119 ID which network backends will use to access the credentials. The
4120 @option{endpoint} is either @option{server} or @option{client} depending
4121 on whether the QEMU network backend that uses the credentials will be
4122 acting as a client or as a server. If @option{verify-peer} is enabled
4123 (the default) then once the handshake is completed, the peer credentials
4124 will be verified. With x509 certificates, this implies that the clients
4125 must be provided with valid client certificates too.
4127 The @var{dir} parameter tells QEMU where to find the credential
4128 files. For server endpoints, this directory may contain a file
4129 @var{dh-params.pem} providing diffie-hellman parameters to use
4130 for the TLS server. If the file is missing, QEMU will generate
4131 a set of DH parameters at startup. This is a computationally
4132 expensive operation that consumes random pool entropy, so it is
4133 recommended that a persistent set of parameters be generated
4134 upfront and saved.
4136 For x509 certificate credentials the directory will contain further files
4137 providing the x509 certificates. The certificates must be stored
4138 in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4139 @var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4140 @var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4142 For the @var{server-key.pem} and @var{client-key.pem} files which
4143 contain sensitive private keys, it is possible to use an encrypted
4144 version by providing the @var{passwordid} parameter. This provides
4145 the ID of a previously created @code{secret} object containing the
4146 password for decryption.
4148 The @var{priority} parameter allows to override the global default
4149 priority used by gnutls. This can be useful if the system administrator
4150 needs to use a weaker set of crypto priorities for QEMU without
4151 potentially forcing the weakness onto all applications. Or conversely
4152 if one wants wants a stronger default for QEMU than for all other
4153 applications, they can do this through this parameter. Its format is
4154 a gnutls priority string as described at
4155 @url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4157 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4159 Interval @var{t} can't be 0, this filter batches the packet delivery: all
4160 packets arriving in a given interval on netdev @var{netdevid} are delayed
4161 until the end of the interval. Interval is in microseconds.
4162 @option{status} is optional that indicate whether the netfilter is
4163 on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4165 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4167 @option{all}: the filter is attached both to the receive and the transmit
4168 queue of the netdev (default).
4170 @option{rx}: the filter is attached to the receive queue of the netdev,
4171 where it will receive packets sent to the netdev.
4173 @option{tx}: the filter is attached to the transmit queue of the netdev,
4174 where it will receive packets sent by the netdev.
4176 @item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4178 filter-mirror on netdev @var{netdevid},mirror net packet to chardev@var{chardevid}, if it has the vnet_hdr_support flag, filter-mirror will mirror packet with vnet_hdr_len.
4180 @item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4182 filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4183 @var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4184 filter-redirector will redirect packet with vnet_hdr_len.
4185 Create a filter-redirector we need to differ outdev id from indev id, id can not
4186 be the same. we can just use indev or outdev, but at least one of indev or outdev
4187 need to be specified.
4189 @item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4191 Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4192 secondary from primary to keep secondary tcp connection,and rewrite
4193 tcp packet to primary from secondary make tcp packet can be handled by
4194 client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4196 usage:
4197 colo secondary:
4198 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4199 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4200 -object filter-rewriter,id=rew0,netdev=hn0,queue=all
4202 @item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4204 Dump the network traffic on netdev @var{dev} to the file specified by
4205 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4206 The file format is libpcap, so it can be analyzed with tools such as tcpdump
4207 or Wireshark.
4209 @item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4211 Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4212 secondary packet. If the packets are same, we will output primary
4213 packet to outdev@var{chardevid}, else we will notify colo-frame
4214 do checkpoint and send primary packet to outdev@var{chardevid}.
4215 if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4217 we must use it with the help of filter-mirror and filter-redirector.
4219 @example
4221 primary:
4222 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4223 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4224 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4225 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4226 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4227 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4228 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4229 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4230 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4231 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4232 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4233 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4235 secondary:
4236 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4237 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4238 -chardev socket,id=red0,host=3.3.3.3,port=9003
4239 -chardev socket,id=red1,host=3.3.3.3,port=9004
4240 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4241 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4243 @end example
4245 If you want to know the detail of above command line, you can read
4246 the colo-compare git log.
4248 @item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4250 Creates a cryptodev backend which executes crypto opreation from
4251 the QEMU cipher APIS. The @var{id} parameter is
4252 a unique ID that will be used to reference this cryptodev backend from
4253 the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4254 which specify the queue number of cryptodev backend, the default of
4255 @var{queues} is 1.
4257 @example
4259 # qemu-system-x86_64 \
4260 [...] \
4261 -object cryptodev-backend-builtin,id=cryptodev0 \
4262 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4263 [...]
4264 @end example
4266 @item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4268 Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4269 The @var{id} parameter is a unique ID that will be used to reference this
4270 cryptodev backend from the @option{virtio-crypto} device.
4271 The chardev should be a unix domain socket backed one. The vhost-user uses
4272 a specifically defined protocol to pass vhost ioctl replacement messages
4273 to an application on the other end of the socket.
4274 The @var{queues} parameter is optional, which specify the queue number
4275 of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4277 @example
4279 # qemu-system-x86_64 \
4280 [...] \
4281 -chardev socket,id=chardev0,path=/path/to/socket \
4282 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4283 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4284 [...]
4285 @end example
4287 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4288 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4290 Defines a secret to store a password, encryption key, or some other sensitive
4291 data. The sensitive data can either be passed directly via the @var{data}
4292 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4293 parameter is insecure unless the sensitive data is encrypted.
4295 The sensitive data can be provided in raw format (the default), or base64.
4296 When encoded as JSON, the raw format only supports valid UTF-8 characters,
4297 so base64 is recommended for sending binary data. QEMU will convert from
4298 which ever format is provided to the format it needs internally. eg, an
4299 RBD password can be provided in raw format, even though it will be base64
4300 encoded when passed onto the RBD sever.
4302 For added protection, it is possible to encrypt the data associated with
4303 a secret using the AES-256-CBC cipher. Use of encryption is indicated
4304 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4305 parameter provides the ID of a previously defined secret that contains
4306 the AES-256 decryption key. This key should be 32-bytes long and be
4307 base64 encoded. The @var{iv} parameter provides the random initialization
4308 vector used for encryption of this particular secret and should be a
4309 base64 encrypted string of the 16-byte IV.
4311 The simplest (insecure) usage is to provide the secret inline
4313 @example
4315 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4317 @end example
4319 The simplest secure usage is to provide the secret via a file
4321 # printf "letmein" > mypasswd.txt
4322 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4324 For greater security, AES-256-CBC should be used. To illustrate usage,
4325 consider the openssl command line tool which can encrypt the data. Note
4326 that when encrypting, the plaintext must be padded to the cipher block
4327 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4329 First a master key needs to be created in base64 encoding:
4331 @example
4332 # openssl rand -base64 32 > key.b64
4333 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
4334 @end example
4336 Each secret to be encrypted needs to have a random initialization vector
4337 generated. These do not need to be kept secret
4339 @example
4340 # openssl rand -base64 16 > iv.b64
4341 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
4342 @end example
4344 The secret to be defined can now be encrypted, in this case we're
4345 telling openssl to base64 encode the result, but it could be left
4346 as raw bytes if desired.
4348 @example
4349 # SECRET=$(printf "letmein" |
4350 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4351 @end example
4353 When launching QEMU, create a master secret pointing to @code{key.b64}
4354 and specify that to be used to decrypt the user password. Pass the
4355 contents of @code{iv.b64} to the second secret
4357 @example
4358 # $QEMU \
4359 -object secret,id=secmaster0,format=base64,file=key.b64 \
4360 -object secret,id=sec0,keyid=secmaster0,format=base64,\
4361 data=$SECRET,iv=$(<iv.b64)
4362 @end example
4364 @item -object sev-guest,id=@var{id},cbitpos=@var{cbitpos},reduced-phys-bits=@var{val},[sev-device=@var{string},policy=@var{policy},handle=@var{handle},dh-cert-file=@var{file},session-file=@var{file}]
4366 Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4367 to provide the guest memory encryption support on AMD processors.
4369 When memory encryption is enabled, one of the physical address bit (aka the
4370 C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4371 is used to provide the C-bit position. The C-bit position is Host family dependent
4372 hence user must provide this value. On EPYC, the value should be 47.
4374 When memory encryption is enabled, we loose certain bits in physical address space.
4375 The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4376 physical address space. Similar to C-bit, the value is Host family dependent.
4377 On EPYC, the value should be 5.
4379 The @option{sev-device} provides the device file to use for communicating with
4380 the SEV firmware running inside AMD Secure Processor. The default device is
4381 '/dev/sev'. If hardware supports memory encryption then /dev/sev devices are
4382 created by CCP driver.
4384 The @option{policy} provides the guest policy to be enforced by the SEV firmware
4385 and restrict what configuration and operational commands can be performed on this
4386 guest by the hypervisor. The policy should be provided by the guest owner and is
4387 bound to the guest and cannot be changed throughout the lifetime of the guest.
4388 The default is 0.
4390 If guest @option{policy} allows sharing the key with another SEV guest then
4391 @option{handle} can be use to provide handle of the guest from which to share
4392 the key.
4394 The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4395 Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters
4396 are used for establishing a cryptographic session with the guest owner to
4397 negotiate keys used for attestation. The file must be encoded in base64.
4399 e.g to launch a SEV guest
4400 @example
4401 # $QEMU \
4402 ......
4403 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \
4404 -machine ...,memory-encryption=sev0
4405 .....
4407 @end example
4408 @end table
4410 ETEXI
4413 HXCOMM This is the last statement. Insert new options before this line!
4414 STEXI
4415 @end table
4416 ETEXI