net: Make net_client_init() static
[qemu.git] / qemu-options.hx
blob57815998f106b55836af809622d54c1706f437dc
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 QEMU_ARCH_ALL)
48 STEXI
49 @item -machine [type=]@var{name}[,prop=@var{value}[,...]]
50 @findex -machine
51 Select the emulated machine by @var{name}. Use @code{-machine help} to list
52 available machines.
54 For architectures which aim to support live migration compatibility
55 across releases, each release will introduce a new versioned machine
56 type. For example, the 2.8.0 release introduced machine types
57 ``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures.
59 To allow live migration of guests from QEMU version 2.8.0, to QEMU
60 version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8''
61 and ``pc-q35-2.8'' machines too. To allow users live migrating VMs
62 to skip multiple intermediate releases when upgrading, new releases
63 of QEMU will support machine types from many previous versions.
65 Supported machine properties are:
66 @table @option
67 @item accel=@var{accels1}[:@var{accels2}[:...]]
68 This is used to enable an accelerator. Depending on the target architecture,
69 kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
70 more than one accelerator specified, the next one is used if the previous one
71 fails to initialize.
72 @item kernel_irqchip=on|off
73 Controls in-kernel irqchip support for the chosen accelerator when available.
74 @item gfx_passthru=on|off
75 Enables IGD GFX passthrough support for the chosen machine when available.
76 @item vmport=on|off|auto
77 Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
78 value based on accel. For accel=xen the default is off otherwise the default
79 is on.
80 @item kvm_shadow_mem=size
81 Defines the size of the KVM shadow MMU.
82 @item dump-guest-core=on|off
83 Include guest memory in a core dump. The default is on.
84 @item mem-merge=on|off
85 Enables or disables memory merge support. This feature, when supported by
86 the host, de-duplicates identical memory pages among VMs instances
87 (enabled by default).
88 @item aes-key-wrap=on|off
89 Enables or disables AES key wrapping support on s390-ccw hosts. This feature
90 controls whether AES wrapping keys will be created to allow
91 execution of AES cryptographic functions. The default is on.
92 @item dea-key-wrap=on|off
93 Enables or disables DEA key wrapping support on s390-ccw hosts. This feature
94 controls whether DEA wrapping keys will be created to allow
95 execution of DEA cryptographic functions. The default is on.
96 @item nvdimm=on|off
97 Enables or disables NVDIMM support. The default is off.
98 @item s390-squash-mcss=on|off
99 Enables or disables squashing subchannels into the default css.
100 The default is off.
101 NOTE: This property is deprecated and will be removed in future releases.
102 The ``s390-squash-mcss=on`` property has been obsoleted by allowing the
103 cssid to be chosen freely. Instead of squashing subchannels into the
104 default channel subsystem image for guests that do not support multiple
105 channel subsystems, all devices can be put into the default channel
106 subsystem image.
107 @item enforce-config-section=on|off
108 If @option{enforce-config-section} is set to @var{on}, force migration
109 code to send configuration section even if the machine-type sets the
110 @option{migration.send-configuration} property to @var{off}.
111 NOTE: this parameter is deprecated. Please use @option{-global}
112 @option{migration.send-configuration}=@var{on|off} instead.
113 @end table
114 ETEXI
116 HXCOMM Deprecated by -machine
117 DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
119 DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
120 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
121 STEXI
122 @item -cpu @var{model}
123 @findex -cpu
124 Select CPU model (@code{-cpu help} for list and additional feature selection)
125 ETEXI
127 DEF("accel", HAS_ARG, QEMU_OPTION_accel,
128 "-accel [accel=]accelerator[,thread=single|multi]\n"
129 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n"
130 " thread=single|multi (enable multi-threaded TCG)", QEMU_ARCH_ALL)
131 STEXI
132 @item -accel @var{name}[,prop=@var{value}[,...]]
133 @findex -accel
134 This is used to enable an accelerator. Depending on the target architecture,
135 kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
136 more than one accelerator specified, the next one is used if the previous one
137 fails to initialize.
138 @table @option
139 @item thread=single|multi
140 Controls number of TCG threads. When the TCG is multi-threaded there will be one
141 thread per vCPU therefor taking advantage of additional host cores. The default
142 is to enable multi-threading where both the back-end and front-ends support it and
143 no incompatible TCG features have been enabled (e.g. icount/replay).
144 @end table
145 ETEXI
147 DEF("smp", HAS_ARG, QEMU_OPTION_smp,
148 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
149 " set the number of CPUs to 'n' [default=1]\n"
150 " maxcpus= maximum number of total cpus, including\n"
151 " offline CPUs for hotplug, etc\n"
152 " cores= number of CPU cores on one socket\n"
153 " threads= number of threads on one CPU core\n"
154 " sockets= number of discrete sockets in the system\n",
155 QEMU_ARCH_ALL)
156 STEXI
157 @item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
158 @findex -smp
159 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
160 CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
161 to 4.
162 For the PC target, the number of @var{cores} per socket, the number
163 of @var{threads} per cores and the total number of @var{sockets} can be
164 specified. Missing values will be computed. If any on the three values is
165 given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
166 specifies the maximum number of hotpluggable CPUs.
167 ETEXI
169 DEF("numa", HAS_ARG, QEMU_OPTION_numa,
170 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
171 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
172 "-numa dist,src=source,dst=destination,val=distance\n"
173 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n",
174 QEMU_ARCH_ALL)
175 STEXI
176 @item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
177 @itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
178 @itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance}
179 @itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}]
180 @findex -numa
181 Define a NUMA node and assign RAM and VCPUs to it.
182 Set the NUMA distance from a source node to a destination node.
184 Legacy VCPU assignment uses @samp{cpus} option where
185 @var{firstcpu} and @var{lastcpu} are CPU indexes. Each
186 @samp{cpus} option represent a contiguous range of CPU indexes
187 (or a single VCPU if @var{lastcpu} is omitted). A non-contiguous
188 set of VCPUs can be represented by providing multiple @samp{cpus}
189 options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically
190 split between them.
192 For example, the following option assigns VCPUs 0, 1, 2 and 5 to
193 a NUMA node:
194 @example
195 -numa node,cpus=0-2,cpus=5
196 @end example
198 @samp{cpu} option is a new alternative to @samp{cpus} option
199 which uses @samp{socket-id|core-id|thread-id} properties to assign
200 CPU objects to a @var{node} using topology layout properties of CPU.
201 The set of properties is machine specific, and depends on used
202 machine type/@samp{smp} options. It could be queried with
203 @samp{hotpluggable-cpus} monitor command.
204 @samp{node-id} property specifies @var{node} to which CPU object
205 will be assigned, it's required for @var{node} to be declared
206 with @samp{node} option before it's used with @samp{cpu} option.
208 For example:
209 @example
210 -M pc \
211 -smp 1,sockets=2,maxcpus=2 \
212 -numa node,nodeid=0 -numa node,nodeid=1 \
213 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
214 @end example
216 @samp{mem} assigns a given RAM amount to a node. @samp{memdev}
217 assigns RAM from a given memory backend device to a node. If
218 @samp{mem} and @samp{memdev} are omitted in all nodes, RAM is
219 split equally between them.
221 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
222 if one node uses @samp{memdev}, all of them have to use it.
224 @var{source} and @var{destination} are NUMA node IDs.
225 @var{distance} is the NUMA distance from @var{source} to @var{destination}.
226 The distance from a node to itself is always 10. If any pair of nodes is
227 given a distance, then all pairs must be given distances. Although, when
228 distances are only given in one direction for each pair of nodes, then
229 the distances in the opposite directions are assumed to be the same. If,
230 however, an asymmetrical pair of distances is given for even one node
231 pair, then all node pairs must be provided distance values for both
232 directions, even when they are symmetrical. When a node is unreachable
233 from another node, set the pair's distance to 255.
235 Note that the -@option{numa} option doesn't allocate any of the
236 specified resources, it just assigns existing resources to NUMA
237 nodes. This means that one still has to use the @option{-m},
238 @option{-smp} options to allocate RAM and VCPUs respectively.
240 ETEXI
242 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
243 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
244 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
245 STEXI
246 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
247 @findex -add-fd
249 Add a file descriptor to an fd set. Valid options are:
251 @table @option
252 @item fd=@var{fd}
253 This option defines the file descriptor of which a duplicate is added to fd set.
254 The file descriptor cannot be stdin, stdout, or stderr.
255 @item set=@var{set}
256 This option defines the ID of the fd set to add the file descriptor to.
257 @item opaque=@var{opaque}
258 This option defines a free-form string that can be used to describe @var{fd}.
259 @end table
261 You can open an image using pre-opened file descriptors from an fd set:
262 @example
263 qemu-system-i386
264 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
265 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
266 -drive file=/dev/fdset/2,index=0,media=disk
267 @end example
268 ETEXI
270 DEF("set", HAS_ARG, QEMU_OPTION_set,
271 "-set group.id.arg=value\n"
272 " set <arg> parameter for item <id> of type <group>\n"
273 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
274 STEXI
275 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
276 @findex -set
277 Set parameter @var{arg} for item @var{id} of type @var{group}
278 ETEXI
280 DEF("global", HAS_ARG, QEMU_OPTION_global,
281 "-global driver.property=value\n"
282 "-global driver=driver,property=property,value=value\n"
283 " set a global default for a driver property\n",
284 QEMU_ARCH_ALL)
285 STEXI
286 @item -global @var{driver}.@var{prop}=@var{value}
287 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
288 @findex -global
289 Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
291 @example
292 qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
293 @end example
295 In particular, you can use this to set driver properties for devices which are
296 created automatically by the machine model. To create a device which is not
297 created automatically and set properties on it, use -@option{device}.
299 -global @var{driver}.@var{prop}=@var{value} is shorthand for -global
300 driver=@var{driver},property=@var{prop},value=@var{value}. The
301 longhand syntax works even when @var{driver} contains a dot.
302 ETEXI
304 DEF("boot", HAS_ARG, QEMU_OPTION_boot,
305 "-boot [order=drives][,once=drives][,menu=on|off]\n"
306 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
307 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
308 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
309 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
310 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
311 QEMU_ARCH_ALL)
312 STEXI
313 @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]
314 @findex -boot
315 Specify boot order @var{drives} as a string of drive letters. Valid
316 drive letters depend on the target architecture. The x86 PC uses: a, b
317 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
318 from network adapter 1-4), hard disk boot is the default. To apply a
319 particular boot order only on the first startup, specify it via
320 @option{once}. Note that the @option{order} or @option{once} parameter
321 should not be used together with the @option{bootindex} property of
322 devices, since the firmware implementations normally do not support both
323 at the same time.
325 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
326 as firmware/BIOS supports them. The default is non-interactive boot.
328 A splash picture could be passed to bios, enabling user to show it as logo,
329 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
330 supports them. Currently Seabios for X86 system support it.
331 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
332 format(true color). The resolution should be supported by the SVGA mode, so
333 the recommended is 320x240, 640x480, 800x640.
335 A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
336 when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
337 reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
338 system support it.
340 Do strict boot via @option{strict=on} as far as firmware/BIOS
341 supports it. This only effects when boot priority is changed by
342 bootindex options. The default is non-strict boot.
344 @example
345 # try to boot from network first, then from hard disk
346 qemu-system-i386 -boot order=nc
347 # boot from CD-ROM first, switch back to default order after reboot
348 qemu-system-i386 -boot once=d
349 # boot with a splash picture for 5 seconds.
350 qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
351 @end example
353 Note: The legacy format '-boot @var{drives}' is still supported but its
354 use is discouraged as it may be removed from future versions.
355 ETEXI
357 DEF("m", HAS_ARG, QEMU_OPTION_m,
358 "-m [size=]megs[,slots=n,maxmem=size]\n"
359 " configure guest RAM\n"
360 " size: initial amount of guest memory\n"
361 " slots: number of hotplug slots (default: none)\n"
362 " maxmem: maximum amount of guest memory (default: none)\n"
363 "NOTE: Some architectures might enforce a specific granularity\n",
364 QEMU_ARCH_ALL)
365 STEXI
366 @item -m [size=]@var{megs}[,slots=n,maxmem=size]
367 @findex -m
368 Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
369 Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
370 megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
371 could be used to set amount of hotpluggable memory slots and maximum amount of
372 memory. Note that @var{maxmem} must be aligned to the page size.
374 For example, the following command-line sets the guest startup RAM size to
375 1GB, creates 3 slots to hotplug additional memory and sets the maximum
376 memory the guest can reach to 4GB:
378 @example
379 qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
380 @end example
382 If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
383 be enabled and the guest startup RAM will never increase.
384 ETEXI
386 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
387 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
388 STEXI
389 @item -mem-path @var{path}
390 @findex -mem-path
391 Allocate guest RAM from a temporarily created file in @var{path}.
392 ETEXI
394 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
395 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
396 QEMU_ARCH_ALL)
397 STEXI
398 @item -mem-prealloc
399 @findex -mem-prealloc
400 Preallocate memory when using -mem-path.
401 ETEXI
403 DEF("k", HAS_ARG, QEMU_OPTION_k,
404 "-k language use keyboard layout (for example 'fr' for French)\n",
405 QEMU_ARCH_ALL)
406 STEXI
407 @item -k @var{language}
408 @findex -k
409 Use keyboard layout @var{language} (for example @code{fr} for
410 French). This option is only needed where it is not easy to get raw PC
411 keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
412 display). You don't normally need to use it on PC/Linux or PC/Windows
413 hosts.
415 The available layouts are:
416 @example
417 ar de-ch es fo fr-ca hu ja mk no pt-br sv
418 da en-gb et fr fr-ch is lt nl pl ru th
419 de en-us fi fr-be hr it lv nl-be pt sl tr
420 @end example
422 The default is @code{en-us}.
423 ETEXI
426 DEF("audio-help", 0, QEMU_OPTION_audio_help,
427 "-audio-help print list of audio drivers and their options\n",
428 QEMU_ARCH_ALL)
429 STEXI
430 @item -audio-help
431 @findex -audio-help
432 Will show the audio subsystem help: list of drivers, tunable
433 parameters.
434 ETEXI
436 DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
437 "-soundhw c1,... enable audio support\n"
438 " and only specified sound cards (comma separated list)\n"
439 " use '-soundhw help' to get the list of supported cards\n"
440 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
441 STEXI
442 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
443 @findex -soundhw
444 Enable audio and selected sound hardware. Use 'help' to print all
445 available sound hardware.
447 @example
448 qemu-system-i386 -soundhw sb16,adlib disk.img
449 qemu-system-i386 -soundhw es1370 disk.img
450 qemu-system-i386 -soundhw ac97 disk.img
451 qemu-system-i386 -soundhw hda disk.img
452 qemu-system-i386 -soundhw all disk.img
453 qemu-system-i386 -soundhw help
454 @end example
456 Note that Linux's i810_audio OSS kernel (for AC97) module might
457 require manually specifying clocking.
459 @example
460 modprobe i810_audio clocking=48000
461 @end example
462 ETEXI
464 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
465 "-balloon none disable balloon device\n"
466 "-balloon virtio[,addr=str]\n"
467 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
468 STEXI
469 @item -balloon none
470 @findex -balloon
471 Disable balloon device.
472 @item -balloon virtio[,addr=@var{addr}]
473 Enable virtio balloon device (default), optionally with PCI address
474 @var{addr}.
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 an empty string here in order to
747 disable 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("net", HAS_ARG, QEMU_OPTION_net,
2008 "-net nic[,vlan=n][,netdev=nd][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
2009 " configure or create an on-board (or machine default) NIC and\n"
2010 " connect it either to VLAN 'n' or the netdev 'nd' (for pluggable\n"
2011 " NICs please use '-device devtype,netdev=nd' instead)\n"
2012 "-net dump[,vlan=n][,file=f][,len=n]\n"
2013 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n"
2014 "-net none use it alone to have zero network devices. If no -net option\n"
2015 " is provided, the default is '-net nic -net user'\n"
2016 "-net ["
2017 #ifdef CONFIG_SLIRP
2018 "user|"
2019 #endif
2020 "tap|"
2021 "bridge|"
2022 #ifdef CONFIG_VDE
2023 "vde|"
2024 #endif
2025 #ifdef CONFIG_NETMAP
2026 "netmap|"
2027 #endif
2028 "socket][,vlan=n][,option][,option][,...]\n"
2029 " old way to initialize a host network interface\n"
2030 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2031 STEXI
2032 @item -net nic[,vlan=@var{n}][,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2033 @findex -net
2034 Configure or create an on-board (or machine default) Network Interface Card
2035 (NIC) and connect it either to VLAN @var{n} (@var{n} = 0 is the default), or
2036 to the netdev @var{nd}. The NIC is an e1000 by default on the PC
2037 target. Optionally, the MAC address can be changed to @var{mac}, the
2038 device address set to @var{addr} (PCI cards only),
2039 and a @var{name} can be assigned for use in monitor commands.
2040 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2041 that the card should have; this option currently only affects virtio cards; set
2042 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2043 NIC is created. QEMU can emulate several different models of network card.
2044 Valid values for @var{type} are
2045 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
2046 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
2047 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
2048 Not all devices are supported on all targets. Use @code{-net nic,model=help}
2049 for a list of available devices for your target.
2051 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2052 @findex -netdev
2053 @item -net user[,@var{option}][,@var{option}][,...]
2054 Use the user mode network stack which requires no administrator
2055 privilege to run. Valid options are:
2057 @table @option
2058 @item vlan=@var{n}
2059 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
2061 @item id=@var{id}
2062 @itemx name=@var{name}
2063 Assign symbolic name for use in monitor commands.
2065 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
2066 be enabled. If neither is specified both protocols are enabled.
2068 @item net=@var{addr}[/@var{mask}]
2069 Set IP network address the guest will see. Optionally specify the netmask,
2070 either in the form a.b.c.d or as number of valid top-most bits. Default is
2071 10.0.2.0/24.
2073 @item host=@var{addr}
2074 Specify the guest-visible address of the host. Default is the 2nd IP in the
2075 guest network, i.e. x.x.x.2.
2077 @item ipv6-net=@var{addr}[/@var{int}]
2078 Set IPv6 network address the guest will see (default is fec0::/64). The
2079 network prefix is given in the usual hexadecimal IPv6 address
2080 notation. The prefix size is optional, and is given as the number of
2081 valid top-most bits (default is 64).
2083 @item ipv6-host=@var{addr}
2084 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2085 the guest network, i.e. xxxx::2.
2087 @item restrict=on|off
2088 If this option is enabled, the guest will be isolated, i.e. it will not be
2089 able to contact the host and no guest IP packets will be routed over the host
2090 to the outside. This option does not affect any explicitly set forwarding rules.
2092 @item hostname=@var{name}
2093 Specifies the client hostname reported by the built-in DHCP server.
2095 @item dhcpstart=@var{addr}
2096 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2097 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2099 @item dns=@var{addr}
2100 Specify the guest-visible address of the virtual nameserver. The address must
2101 be different from the host address. Default is the 3rd IP in the guest network,
2102 i.e. x.x.x.3.
2104 @item ipv6-dns=@var{addr}
2105 Specify the guest-visible address of the IPv6 virtual nameserver. The address
2106 must be different from the host address. Default is the 3rd IP in the guest
2107 network, i.e. xxxx::3.
2109 @item dnssearch=@var{domain}
2110 Provides an entry for the domain-search list sent by the built-in
2111 DHCP server. More than one domain suffix can be transmitted by specifying
2112 this option multiple times. If supported, this will cause the guest to
2113 automatically try to append the given domain suffix(es) in case a domain name
2114 can not be resolved.
2116 Example:
2117 @example
2118 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
2119 @end example
2121 @item tftp=@var{dir}
2122 When using the user mode network stack, activate a built-in TFTP
2123 server. The files in @var{dir} will be exposed as the root of a TFTP server.
2124 The TFTP client on the guest must be configured in binary mode (use the command
2125 @code{bin} of the Unix TFTP client).
2127 @item bootfile=@var{file}
2128 When using the user mode network stack, broadcast @var{file} as the BOOTP
2129 filename. In conjunction with @option{tftp}, this can be used to network boot
2130 a guest from a local directory.
2132 Example (using pxelinux):
2133 @example
2134 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2135 @end example
2137 @item smb=@var{dir}[,smbserver=@var{addr}]
2138 When using the user mode network stack, activate a built-in SMB
2139 server so that Windows OSes can access to the host files in @file{@var{dir}}
2140 transparently. The IP address of the SMB server can be set to @var{addr}. By
2141 default the 4th IP in the guest network is used, i.e. x.x.x.4.
2143 In the guest Windows OS, the line:
2144 @example
2145 10.0.2.4 smbserver
2146 @end example
2147 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2148 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2150 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2152 Note that a SAMBA server must be installed on the host OS.
2153 QEMU was tested successfully with smbd versions from Red Hat 9,
2154 Fedora Core 3 and OpenSUSE 11.x.
2156 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2157 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2158 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2159 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2160 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2161 be bound to a specific host interface. If no connection type is set, TCP is
2162 used. This option can be given multiple times.
2164 For example, to redirect host X11 connection from screen 1 to guest
2165 screen 0, use the following:
2167 @example
2168 # on the host
2169 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
2170 # this host xterm should open in the guest X11 server
2171 xterm -display :1
2172 @end example
2174 To redirect telnet connections from host port 5555 to telnet port on
2175 the guest, use the following:
2177 @example
2178 # on the host
2179 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
2180 telnet localhost 5555
2181 @end example
2183 Then when you use on the host @code{telnet localhost 5555}, you
2184 connect to the guest telnet server.
2186 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2187 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2188 Forward guest TCP connections to the IP address @var{server} on port @var{port}
2189 to the character device @var{dev} or to a program executed by @var{cmd:command}
2190 which gets spawned for each connection. This option can be given multiple times.
2192 You can either use a chardev directly and have that one used throughout QEMU's
2193 lifetime, like in the following example:
2195 @example
2196 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2197 # the guest accesses it
2198 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
2199 @end example
2201 Or you can execute a command on every TCP connection established by the guest,
2202 so that QEMU behaves similar to an inetd process for that virtual server:
2204 @example
2205 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2206 # and connect the TCP stream to its stdin/stdout
2207 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2208 @end example
2210 @end table
2212 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2213 processed and applied to -net user. Mixing them with the new configuration
2214 syntax gives undefined results. Their use for new applications is discouraged
2215 as they will be removed from future versions.
2217 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2218 @itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2219 Connect the host TAP network interface @var{name} to VLAN @var{n}.
2221 Use the network script @var{file} to configure it and the network script
2222 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2223 automatically provides one. The default network configure script is
2224 @file{/etc/qemu-ifup} and the default network deconfigure script is
2225 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2226 to disable script execution.
2228 If running QEMU as an unprivileged user, use the network helper
2229 @var{helper} to configure the TAP interface and attach it to the bridge.
2230 The default network helper executable is @file{/path/to/qemu-bridge-helper}
2231 and the default bridge device is @file{br0}.
2233 @option{fd}=@var{h} can be used to specify the handle of an already
2234 opened host TAP interface.
2236 Examples:
2238 @example
2239 #launch a QEMU instance with the default network script
2240 qemu-system-i386 linux.img -net nic -net tap
2241 @end example
2243 @example
2244 #launch a QEMU instance with two NICs, each one connected
2245 #to a TAP device
2246 qemu-system-i386 linux.img \
2247 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2248 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2249 @end example
2251 @example
2252 #launch a QEMU instance with the default network helper to
2253 #connect a TAP device to bridge br0
2254 qemu-system-i386 linux.img \
2255 -net nic -net tap,"helper=/path/to/qemu-bridge-helper"
2256 @end example
2258 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2259 @itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
2260 Connect a host TAP network interface to a host bridge device.
2262 Use the network helper @var{helper} to configure the TAP interface and
2263 attach it to the bridge. The default network helper executable is
2264 @file{/path/to/qemu-bridge-helper} and the default bridge
2265 device is @file{br0}.
2267 Examples:
2269 @example
2270 #launch a QEMU instance with the default network helper to
2271 #connect a TAP device to bridge br0
2272 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
2273 @end example
2275 @example
2276 #launch a QEMU instance with the default network helper to
2277 #connect a TAP device to bridge qemubr0
2278 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
2279 @end example
2281 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2282 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2284 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
2285 machine using a TCP socket connection. If @option{listen} is
2286 specified, QEMU waits for incoming connections on @var{port}
2287 (@var{host} is optional). @option{connect} is used to connect to
2288 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2289 specifies an already opened TCP socket.
2291 Example:
2292 @example
2293 # launch a first QEMU instance
2294 qemu-system-i386 linux.img \
2295 -net nic,macaddr=52:54:00:12:34:56 \
2296 -net socket,listen=:1234
2297 # connect the VLAN 0 of this instance to the VLAN 0
2298 # of the first instance
2299 qemu-system-i386 linux.img \
2300 -net nic,macaddr=52:54:00:12:34:57 \
2301 -net socket,connect=127.0.0.1:1234
2302 @end example
2304 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2305 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2307 Create a VLAN @var{n} shared with another QEMU virtual
2308 machines using a UDP multicast socket, effectively making a bus for
2309 every QEMU with same multicast address @var{maddr} and @var{port}.
2310 NOTES:
2311 @enumerate
2312 @item
2313 Several QEMU can be running on different hosts and share same bus (assuming
2314 correct multicast setup for these hosts).
2315 @item
2316 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2317 @url{http://user-mode-linux.sf.net}.
2318 @item
2319 Use @option{fd=h} to specify an already opened UDP multicast socket.
2320 @end enumerate
2322 Example:
2323 @example
2324 # launch one QEMU instance
2325 qemu-system-i386 linux.img \
2326 -net nic,macaddr=52:54:00:12:34:56 \
2327 -net socket,mcast=230.0.0.1:1234
2328 # launch another QEMU instance on same "bus"
2329 qemu-system-i386 linux.img \
2330 -net nic,macaddr=52:54:00:12:34:57 \
2331 -net socket,mcast=230.0.0.1:1234
2332 # launch yet another QEMU instance on same "bus"
2333 qemu-system-i386 linux.img \
2334 -net nic,macaddr=52:54:00:12:34:58 \
2335 -net socket,mcast=230.0.0.1:1234
2336 @end example
2338 Example (User Mode Linux compat.):
2339 @example
2340 # launch QEMU instance (note mcast address selected
2341 # is UML's default)
2342 qemu-system-i386 linux.img \
2343 -net nic,macaddr=52:54:00:12:34:56 \
2344 -net socket,mcast=239.192.168.1:1102
2345 # launch UML
2346 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2347 @end example
2349 Example (send packets from host's 1.2.3.4):
2350 @example
2351 qemu-system-i386 linux.img \
2352 -net nic,macaddr=52:54:00:12:34:56 \
2353 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2354 @end example
2356 @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}]
2357 @itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],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}]
2358 Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
2359 protocol to transport Ethernet (and other Layer 2) data frames between
2360 two systems. It is present in routers, firewalls and the Linux kernel
2361 (from version 3.3 onwards).
2363 This transport allows a VM to communicate to another VM, router or firewall directly.
2365 @table @option
2366 @item src=@var{srcaddr}
2367 source address (mandatory)
2368 @item dst=@var{dstaddr}
2369 destination address (mandatory)
2370 @item udp
2371 select udp encapsulation (default is ip).
2372 @item srcport=@var{srcport}
2373 source udp port.
2374 @item dstport=@var{dstport}
2375 destination udp port.
2376 @item ipv6
2377 force v6, otherwise defaults to v4.
2378 @item rxcookie=@var{rxcookie}
2379 @itemx txcookie=@var{txcookie}
2380 Cookies are a weak form of security in the l2tpv3 specification.
2381 Their function is mostly to prevent misconfiguration. By default they are 32
2382 bit.
2383 @item cookie64
2384 Set cookie size to 64 bit instead of the default 32
2385 @item counter=off
2386 Force a 'cut-down' L2TPv3 with no counter as in
2387 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2388 @item pincounter=on
2389 Work around broken counter handling in peer. This may also help on
2390 networks which have packet reorder.
2391 @item offset=@var{offset}
2392 Add an extra offset between header and data
2393 @end table
2395 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2396 on the remote Linux host 1.2.3.4:
2397 @example
2398 # Setup tunnel on linux host using raw ip as encapsulation
2399 # on 1.2.3.4
2400 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2401 encap udp udp_sport 16384 udp_dport 16384
2402 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2403 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2404 ifconfig vmtunnel0 mtu 1500
2405 ifconfig vmtunnel0 up
2406 brctl addif br-lan vmtunnel0
2409 # on 4.3.2.1
2410 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2412 qemu-system-i386 linux.img -net nic -net l2tpv3,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2415 @end example
2417 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2418 @itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2419 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2420 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2421 and MODE @var{octalmode} to change default ownership and permissions for
2422 communication port. This option is only available if QEMU has been compiled
2423 with vde support enabled.
2425 Example:
2426 @example
2427 # launch vde switch
2428 vde_switch -F -sock /tmp/myswitch
2429 # launch QEMU instance
2430 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2431 @end example
2433 @item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2435 Create a hub port on QEMU "vlan" @var{hubid}.
2437 The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single
2438 netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
2439 required hub automatically. Alternatively, you can also connect the hubport
2440 to another netdev with ID @var{nd} by using the @option{netdev=@var{nd}}
2441 option.
2443 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2445 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2446 be a unix domain socket backed one. The vhost-user uses a specifically defined
2447 protocol to pass vhost ioctl replacement messages to an application on the other
2448 end of the socket. On non-MSIX guests, the feature can be forced with
2449 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2450 be created for multiqueue vhost-user.
2452 Example:
2453 @example
2454 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2455 -numa node,memdev=mem \
2456 -chardev socket,id=chr0,path=/path/to/socket \
2457 -netdev type=vhost-user,id=net0,chardev=chr0 \
2458 -device virtio-net-pci,netdev=net0
2459 @end example
2461 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
2462 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
2463 At most @var{len} bytes (64k by default) per packet are stored. The file format is
2464 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
2465 Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
2467 @item -net none
2468 Indicate that no network devices should be configured. It is used to
2469 override the default configuration (@option{-net nic -net user}) which
2470 is activated if no @option{-net} options are provided.
2471 ETEXI
2473 STEXI
2474 @end table
2475 ETEXI
2476 DEFHEADING()
2478 DEFHEADING(Character device options:)
2480 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2481 "-chardev help\n"
2482 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2483 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2484 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2485 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2486 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2487 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2488 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2489 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2490 " [,logfile=PATH][,logappend=on|off]\n"
2491 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2492 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2493 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2494 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2495 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2496 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2497 #ifdef _WIN32
2498 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2499 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2500 #else
2501 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2502 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2503 #endif
2504 #ifdef CONFIG_BRLAPI
2505 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2506 #endif
2507 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2508 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2509 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2510 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2511 #endif
2512 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2513 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2514 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2515 #endif
2516 #if defined(CONFIG_SPICE)
2517 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2518 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2519 #endif
2520 , QEMU_ARCH_ALL
2523 STEXI
2525 The general form of a character device option is:
2526 @table @option
2527 @item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2528 @findex -chardev
2529 Backend is one of:
2530 @option{null},
2531 @option{socket},
2532 @option{udp},
2533 @option{msmouse},
2534 @option{vc},
2535 @option{ringbuf},
2536 @option{file},
2537 @option{pipe},
2538 @option{console},
2539 @option{serial},
2540 @option{pty},
2541 @option{stdio},
2542 @option{braille},
2543 @option{tty},
2544 @option{parallel},
2545 @option{parport},
2546 @option{spicevmc},
2547 @option{spiceport}.
2548 The specific backend will determine the applicable options.
2550 Use @code{-chardev help} to print all available chardev backend types.
2552 All devices must have an id, which can be any string up to 127 characters long.
2553 It is used to uniquely identify this device in other command line directives.
2555 A character device may be used in multiplexing mode by multiple front-ends.
2556 Specify @option{mux=on} to enable this mode.
2557 A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2558 backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2559 If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2560 create a multiplexer with your specified ID, and you can then configure multiple
2561 front ends to use that chardev ID for their input/output. Up to four different
2562 front ends can be connected to a single multiplexed chardev. (Without
2563 multiplexing enabled, a chardev can only be used by a single front end.)
2564 For instance you could use this to allow a single stdio chardev to be used by
2565 two serial ports and the QEMU monitor:
2567 @example
2568 -chardev stdio,mux=on,id=char0 \
2569 -mon chardev=char0,mode=readline \
2570 -serial chardev:char0 \
2571 -serial chardev:char0
2572 @end example
2574 You can have more than one multiplexer in a system configuration; for instance
2575 you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2576 multiplexed between the QEMU monitor and a parallel port:
2578 @example
2579 -chardev stdio,mux=on,id=char0 \
2580 -mon chardev=char0,mode=readline \
2581 -parallel chardev:char0 \
2582 -chardev tcp,...,mux=on,id=char1 \
2583 -serial chardev:char1 \
2584 -serial chardev:char1
2585 @end example
2587 When you're using a multiplexed character device, some escape sequences are
2588 interpreted in the input. @xref{mux_keys, Keys in the character backend
2589 multiplexer}.
2591 Note that some other command line options may implicitly create multiplexed
2592 character backends; for instance @option{-serial mon:stdio} creates a
2593 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2594 and @option{-nographic} also multiplexes the console and the monitor to
2595 stdio.
2597 There is currently no support for multiplexing in the other direction
2598 (where a single QEMU front end takes input and output from multiple chardevs).
2600 Every backend supports the @option{logfile} option, which supplies the path
2601 to a file to record all data transmitted via the backend. The @option{logappend}
2602 option controls whether the log file will be truncated or appended to when
2603 opened.
2605 @end table
2607 The available backends are:
2609 @table @option
2610 @item -chardev null,id=@var{id}
2611 A void device. This device will not emit any data, and will drop any data it
2612 receives. The null backend does not take any options.
2614 @item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2616 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2617 unix socket will be created if @option{path} is specified. Behaviour is
2618 undefined if TCP options are specified for a unix socket.
2620 @option{server} specifies that the socket shall be a listening socket.
2622 @option{nowait} specifies that QEMU should not block waiting for a client to
2623 connect to a listening socket.
2625 @option{telnet} specifies that traffic on the socket should interpret telnet
2626 escape sequences.
2628 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2629 the remote end goes away. qemu will delay this many seconds and then attempt
2630 to reconnect. Zero disables reconnecting, and is the default.
2632 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2633 and specifies the id of the TLS credentials to use for the handshake. The
2634 credentials must be previously created with the @option{-object tls-creds}
2635 argument.
2637 TCP and unix socket options are given below:
2639 @table @option
2641 @item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2643 @option{host} for a listening socket specifies the local address to be bound.
2644 For a connecting socket species the remote host to connect to. @option{host} is
2645 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2647 @option{port} for a listening socket specifies the local port to be bound. For a
2648 connecting socket specifies the port on the remote host to connect to.
2649 @option{port} can be given as either a port number or a service name.
2650 @option{port} is required.
2652 @option{to} is only relevant to listening sockets. If it is specified, and
2653 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2654 to and including @option{to} until it succeeds. @option{to} must be specified
2655 as a port number.
2657 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2658 If neither is specified the socket may use either protocol.
2660 @option{nodelay} disables the Nagle algorithm.
2662 @item unix options: path=@var{path}
2664 @option{path} specifies the local path of the unix socket. @option{path} is
2665 required.
2667 @end table
2669 @item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2671 Sends all traffic from the guest to a remote host over UDP.
2673 @option{host} specifies the remote host to connect to. If not specified it
2674 defaults to @code{localhost}.
2676 @option{port} specifies the port on the remote host to connect to. @option{port}
2677 is required.
2679 @option{localaddr} specifies the local address to bind to. If not specified it
2680 defaults to @code{0.0.0.0}.
2682 @option{localport} specifies the local port to bind to. If not specified any
2683 available local port will be used.
2685 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2686 If neither is specified the device may use either protocol.
2688 @item -chardev msmouse,id=@var{id}
2690 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2691 take any options.
2693 @item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2695 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2696 size.
2698 @option{width} and @option{height} specify the width and height respectively of
2699 the console, in pixels.
2701 @option{cols} and @option{rows} specify that the console be sized to fit a text
2702 console with the given dimensions.
2704 @item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2706 Create a ring buffer with fixed size @option{size}.
2707 @var{size} must be a power of two and defaults to @code{64K}.
2709 @item -chardev file,id=@var{id},path=@var{path}
2711 Log all traffic received from the guest to a file.
2713 @option{path} specifies the path of the file to be opened. This file will be
2714 created if it does not already exist, and overwritten if it does. @option{path}
2715 is required.
2717 @item -chardev pipe,id=@var{id},path=@var{path}
2719 Create a two-way connection to the guest. The behaviour differs slightly between
2720 Windows hosts and other hosts:
2722 On Windows, a single duplex pipe will be created at
2723 @file{\\.pipe\@option{path}}.
2725 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2726 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2727 received by the guest. Data written by the guest can be read from
2728 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2729 be present.
2731 @option{path} forms part of the pipe path as described above. @option{path} is
2732 required.
2734 @item -chardev console,id=@var{id}
2736 Send traffic from the guest to QEMU's standard output. @option{console} does not
2737 take any options.
2739 @option{console} is only available on Windows hosts.
2741 @item -chardev serial,id=@var{id},path=@option{path}
2743 Send traffic from the guest to a serial device on the host.
2745 On Unix hosts serial will actually accept any tty device,
2746 not only serial lines.
2748 @option{path} specifies the name of the serial device to open.
2750 @item -chardev pty,id=@var{id}
2752 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2753 not take any options.
2755 @option{pty} is not available on Windows hosts.
2757 @item -chardev stdio,id=@var{id}[,signal=on|off]
2758 Connect to standard input and standard output of the QEMU process.
2760 @option{signal} controls if signals are enabled on the terminal, that includes
2761 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2762 default, use @option{signal=off} to disable it.
2764 @item -chardev braille,id=@var{id}
2766 Connect to a local BrlAPI server. @option{braille} does not take any options.
2768 @item -chardev tty,id=@var{id},path=@var{path}
2770 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2771 DragonFlyBSD hosts. It is an alias for @option{serial}.
2773 @option{path} specifies the path to the tty. @option{path} is required.
2775 @item -chardev parallel,id=@var{id},path=@var{path}
2776 @itemx -chardev parport,id=@var{id},path=@var{path}
2778 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2780 Connect to a local parallel port.
2782 @option{path} specifies the path to the parallel port device. @option{path} is
2783 required.
2785 @item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2787 @option{spicevmc} is only available when spice support is built in.
2789 @option{debug} debug level for spicevmc
2791 @option{name} name of spice channel to connect to
2793 Connect to a spice virtual machine channel, such as vdiport.
2795 @item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2797 @option{spiceport} is only available when spice support is built in.
2799 @option{debug} debug level for spicevmc
2801 @option{name} name of spice port to connect to
2803 Connect to a spice port, allowing a Spice client to handle the traffic
2804 identified by a name (preferably a fqdn).
2805 ETEXI
2807 STEXI
2808 @end table
2809 ETEXI
2810 DEFHEADING()
2812 DEFHEADING(Bluetooth(R) options:)
2813 STEXI
2814 @table @option
2815 ETEXI
2817 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2818 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2819 "-bt hci,host[:id]\n" \
2820 " use host's HCI with the given name\n" \
2821 "-bt hci[,vlan=n]\n" \
2822 " emulate a standard HCI in virtual scatternet 'n'\n" \
2823 "-bt vhci[,vlan=n]\n" \
2824 " add host computer to virtual scatternet 'n' using VHCI\n" \
2825 "-bt device:dev[,vlan=n]\n" \
2826 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2827 QEMU_ARCH_ALL)
2828 STEXI
2829 @item -bt hci[...]
2830 @findex -bt
2831 Defines the function of the corresponding Bluetooth HCI. -bt options
2832 are matched with the HCIs present in the chosen machine type. For
2833 example when emulating a machine with only one HCI built into it, only
2834 the first @code{-bt hci[...]} option is valid and defines the HCI's
2835 logic. The Transport Layer is decided by the machine type. Currently
2836 the machines @code{n800} and @code{n810} have one HCI and all other
2837 machines have none.
2839 @anchor{bt-hcis}
2840 The following three types are recognized:
2842 @table @option
2843 @item -bt hci,null
2844 (default) The corresponding Bluetooth HCI assumes no internal logic
2845 and will not respond to any HCI commands or emit events.
2847 @item -bt hci,host[:@var{id}]
2848 (@code{bluez} only) The corresponding HCI passes commands / events
2849 to / from the physical HCI identified by the name @var{id} (default:
2850 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2851 capable systems like Linux.
2853 @item -bt hci[,vlan=@var{n}]
2854 Add a virtual, standard HCI that will participate in the Bluetooth
2855 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2856 VLANs, devices inside a bluetooth network @var{n} can only communicate
2857 with other devices in the same network (scatternet).
2858 @end table
2860 @item -bt vhci[,vlan=@var{n}]
2861 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2862 to the host bluetooth stack instead of to the emulated target. This
2863 allows the host and target machines to participate in a common scatternet
2864 and communicate. Requires the Linux @code{vhci} driver installed. Can
2865 be used as following:
2867 @example
2868 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2869 @end example
2871 @item -bt device:@var{dev}[,vlan=@var{n}]
2872 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2873 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2874 currently:
2876 @table @option
2877 @item keyboard
2878 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2879 @end table
2880 ETEXI
2882 STEXI
2883 @end table
2884 ETEXI
2885 DEFHEADING()
2887 #ifdef CONFIG_TPM
2888 DEFHEADING(TPM device options:)
2890 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2891 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2892 " use path to provide path to a character device; default is /dev/tpm0\n"
2893 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2894 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2895 "-tpmdev emulator,id=id,chardev=dev\n"
2896 " configure the TPM device using chardev backend\n",
2897 QEMU_ARCH_ALL)
2898 STEXI
2900 The general form of a TPM device option is:
2901 @table @option
2903 @item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2904 @findex -tpmdev
2906 The specific backend type will determine the applicable options.
2907 The @code{-tpmdev} option creates the TPM backend and requires a
2908 @code{-device} option that specifies the TPM frontend interface model.
2910 Use @code{-tpmdev help} to print all available TPM backend types.
2912 @end table
2914 The available backends are:
2916 @table @option
2918 @item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2920 (Linux-host only) Enable access to the host's TPM using the passthrough
2921 driver.
2923 @option{path} specifies the path to the host's TPM device, i.e., on
2924 a Linux host this would be @code{/dev/tpm0}.
2925 @option{path} is optional and by default @code{/dev/tpm0} is used.
2927 @option{cancel-path} specifies the path to the host TPM device's sysfs
2928 entry allowing for cancellation of an ongoing TPM command.
2929 @option{cancel-path} is optional and by default QEMU will search for the
2930 sysfs entry to use.
2932 Some notes about using the host's TPM with the passthrough driver:
2934 The TPM device accessed by the passthrough driver must not be
2935 used by any other application on the host.
2937 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2938 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2939 TPM again and may therefore not show a TPM-specific menu that would
2940 otherwise allow the user to configure the TPM, e.g., allow the user to
2941 enable/disable or activate/deactivate the TPM.
2942 Further, if TPM ownership is released from within a VM then the host's TPM
2943 will get disabled and deactivated. To enable and activate the
2944 TPM again afterwards, the host has to be rebooted and the user is
2945 required to enter the firmware's menu to enable and activate the TPM.
2946 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2948 To create a passthrough TPM use the following two options:
2949 @example
2950 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2951 @end example
2952 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2953 @code{tpmdev=tpm0} in the device option.
2955 @item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2957 (Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2958 chardev backend.
2960 @option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2962 To create a TPM emulator backend device with chardev socket backend:
2963 @example
2965 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2967 @end example
2969 ETEXI
2971 STEXI
2972 @end table
2973 ETEXI
2974 DEFHEADING()
2976 #endif
2978 DEFHEADING(Linux/Multiboot boot specific:)
2979 STEXI
2981 When using these options, you can use a given Linux or Multiboot
2982 kernel without installing it in the disk image. It can be useful
2983 for easier testing of various kernels.
2985 @table @option
2986 ETEXI
2988 DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
2989 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
2990 STEXI
2991 @item -kernel @var{bzImage}
2992 @findex -kernel
2993 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2994 or in multiboot format.
2995 ETEXI
2997 DEF("append", HAS_ARG, QEMU_OPTION_append, \
2998 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
2999 STEXI
3000 @item -append @var{cmdline}
3001 @findex -append
3002 Use @var{cmdline} as kernel command line
3003 ETEXI
3005 DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
3006 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
3007 STEXI
3008 @item -initrd @var{file}
3009 @findex -initrd
3010 Use @var{file} as initial ram disk.
3012 @item -initrd "@var{file1} arg=foo,@var{file2}"
3014 This syntax is only available with multiboot.
3016 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3017 first module.
3018 ETEXI
3020 DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
3021 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
3022 STEXI
3023 @item -dtb @var{file}
3024 @findex -dtb
3025 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3026 on boot.
3027 ETEXI
3029 STEXI
3030 @end table
3031 ETEXI
3032 DEFHEADING()
3034 DEFHEADING(Debug/Expert options:)
3035 STEXI
3036 @table @option
3037 ETEXI
3039 DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3040 "-fw_cfg [name=]<name>,file=<file>\n"
3041 " add named fw_cfg entry with contents from file\n"
3042 "-fw_cfg [name=]<name>,string=<str>\n"
3043 " add named fw_cfg entry with contents from string\n",
3044 QEMU_ARCH_ALL)
3045 STEXI
3047 @item -fw_cfg [name=]@var{name},file=@var{file}
3048 @findex -fw_cfg
3049 Add named fw_cfg entry with contents from file @var{file}.
3051 @item -fw_cfg [name=]@var{name},string=@var{str}
3052 Add named fw_cfg entry with contents from string @var{str}.
3054 The terminating NUL character of the contents of @var{str} will not be
3055 included as part of the fw_cfg item data. To insert contents with
3056 embedded NUL characters, you have to use the @var{file} parameter.
3058 The fw_cfg entries are passed by QEMU through to the guest.
3060 Example:
3061 @example
3062 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3063 @end example
3064 creates an fw_cfg entry named opt/com.mycompany/blob with contents
3065 from ./my_blob.bin.
3067 ETEXI
3069 DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3070 "-serial dev redirect the serial port to char device 'dev'\n",
3071 QEMU_ARCH_ALL)
3072 STEXI
3073 @item -serial @var{dev}
3074 @findex -serial
3075 Redirect the virtual serial port to host character device
3076 @var{dev}. The default device is @code{vc} in graphical mode and
3077 @code{stdio} in non graphical mode.
3079 This option can be used several times to simulate up to 4 serial
3080 ports.
3082 Use @code{-serial none} to disable all serial ports.
3084 Available character devices are:
3085 @table @option
3086 @item vc[:@var{W}x@var{H}]
3087 Virtual console. Optionally, a width and height can be given in pixel with
3088 @example
3089 vc:800x600
3090 @end example
3091 It is also possible to specify width or height in characters:
3092 @example
3093 vc:80Cx24C
3094 @end example
3095 @item pty
3096 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3097 @item none
3098 No device is allocated.
3099 @item null
3100 void device
3101 @item chardev:@var{id}
3102 Use a named character device defined with the @code{-chardev} option.
3103 @item /dev/XXX
3104 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3105 parameters are set according to the emulated ones.
3106 @item /dev/parport@var{N}
3107 [Linux only, parallel port only] Use host parallel port
3108 @var{N}. Currently SPP and EPP parallel port features can be used.
3109 @item file:@var{filename}
3110 Write output to @var{filename}. No character can be read.
3111 @item stdio
3112 [Unix only] standard input/output
3113 @item pipe:@var{filename}
3114 name pipe @var{filename}
3115 @item COM@var{n}
3116 [Windows only] Use host serial port @var{n}
3117 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3118 This implements UDP Net Console.
3119 When @var{remote_host} or @var{src_ip} are not specified
3120 they default to @code{0.0.0.0}.
3121 When not using a specified @var{src_port} a random port is automatically chosen.
3123 If you just want a simple readonly console you can use @code{netcat} or
3124 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3125 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3126 will appear in the netconsole session.
3128 If you plan to send characters back via netconsole or you want to stop
3129 and start QEMU a lot of times, you should have QEMU use the same
3130 source port each time by using something like @code{-serial
3131 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3132 version of netcat which can listen to a TCP port and send and receive
3133 characters via udp. If you have a patched version of netcat which
3134 activates telnet remote echo and single char transfer, then you can
3135 use the following options to set up a netcat redirector to allow
3136 telnet on port 5555 to access the QEMU port.
3137 @table @code
3138 @item QEMU Options:
3139 -serial udp::4555@@:4556
3140 @item netcat options:
3141 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3142 @item telnet options:
3143 localhost 5555
3144 @end table
3146 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3147 The TCP Net Console has two modes of operation. It can send the serial
3148 I/O to a location or wait for a connection from a location. By default
3149 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3150 the @var{server} option QEMU will wait for a client socket application
3151 to connect to the port before continuing, unless the @code{nowait}
3152 option was specified. The @code{nodelay} option disables the Nagle buffering
3153 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3154 set, if the connection goes down it will attempt to reconnect at the
3155 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3156 one TCP connection at a time is accepted. You can use @code{telnet} to
3157 connect to the corresponding character device.
3158 @table @code
3159 @item Example to send tcp console to 192.168.0.2 port 4444
3160 -serial tcp:192.168.0.2:4444
3161 @item Example to listen and wait on port 4444 for connection
3162 -serial tcp::4444,server
3163 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3164 -serial tcp:192.168.0.100:4444,server,nowait
3165 @end table
3167 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3168 The telnet protocol is used instead of raw tcp sockets. The options
3169 work the same as if you had specified @code{-serial tcp}. The
3170 difference is that the port acts like a telnet server or client using
3171 telnet option negotiation. This will also allow you to send the
3172 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3173 sequence. Typically in unix telnet you do it with Control-] and then
3174 type "send break" followed by pressing the enter key.
3176 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3177 A unix domain socket is used instead of a tcp socket. The option works the
3178 same as if you had specified @code{-serial tcp} except the unix domain socket
3179 @var{path} is used for connections.
3181 @item mon:@var{dev_string}
3182 This is a special option to allow the monitor to be multiplexed onto
3183 another serial port. The monitor is accessed with key sequence of
3184 @key{Control-a} and then pressing @key{c}.
3185 @var{dev_string} should be any one of the serial devices specified
3186 above. An example to multiplex the monitor onto a telnet server
3187 listening on port 4444 would be:
3188 @table @code
3189 @item -serial mon:telnet::4444,server,nowait
3190 @end table
3191 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3192 QEMU any more but will be passed to the guest instead.
3194 @item braille
3195 Braille device. This will use BrlAPI to display the braille output on a real
3196 or fake device.
3198 @item msmouse
3199 Three button serial mouse. Configure the guest to use Microsoft protocol.
3200 @end table
3201 ETEXI
3203 DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3204 "-parallel dev redirect the parallel port to char device 'dev'\n",
3205 QEMU_ARCH_ALL)
3206 STEXI
3207 @item -parallel @var{dev}
3208 @findex -parallel
3209 Redirect the virtual parallel port to host device @var{dev} (same
3210 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3211 be used to use hardware devices connected on the corresponding host
3212 parallel port.
3214 This option can be used several times to simulate up to 3 parallel
3215 ports.
3217 Use @code{-parallel none} to disable all parallel ports.
3218 ETEXI
3220 DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3221 "-monitor dev redirect the monitor to char device 'dev'\n",
3222 QEMU_ARCH_ALL)
3223 STEXI
3224 @item -monitor @var{dev}
3225 @findex -monitor
3226 Redirect the monitor to host device @var{dev} (same devices as the
3227 serial port).
3228 The default device is @code{vc} in graphical mode and @code{stdio} in
3229 non graphical mode.
3230 Use @code{-monitor none} to disable the default monitor.
3231 ETEXI
3232 DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3233 "-qmp dev like -monitor but opens in 'control' mode\n",
3234 QEMU_ARCH_ALL)
3235 STEXI
3236 @item -qmp @var{dev}
3237 @findex -qmp
3238 Like -monitor but opens in 'control' mode.
3239 ETEXI
3240 DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3241 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3242 QEMU_ARCH_ALL)
3243 STEXI
3244 @item -qmp-pretty @var{dev}
3245 @findex -qmp-pretty
3246 Like -qmp but uses pretty JSON formatting.
3247 ETEXI
3249 DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3250 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3251 STEXI
3252 @item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3253 @findex -mon
3254 Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3255 easing human reading and debugging.
3256 ETEXI
3258 DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3259 "-debugcon dev redirect the debug console to char device 'dev'\n",
3260 QEMU_ARCH_ALL)
3261 STEXI
3262 @item -debugcon @var{dev}
3263 @findex -debugcon
3264 Redirect the debug console to host device @var{dev} (same devices as the
3265 serial port). The debug console is an I/O port which is typically port
3266 0xe9; writing to that I/O port sends output to this device.
3267 The default device is @code{vc} in graphical mode and @code{stdio} in
3268 non graphical mode.
3269 ETEXI
3271 DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3272 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
3273 STEXI
3274 @item -pidfile @var{file}
3275 @findex -pidfile
3276 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3277 from a script.
3278 ETEXI
3280 DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3281 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
3282 STEXI
3283 @item -singlestep
3284 @findex -singlestep
3285 Run the emulation in single step mode.
3286 ETEXI
3288 DEF("S", 0, QEMU_OPTION_S, \
3289 "-S freeze CPU at startup (use 'c' to start execution)\n",
3290 QEMU_ARCH_ALL)
3291 STEXI
3292 @item -S
3293 @findex -S
3294 Do not start CPU at startup (you must type 'c' in the monitor).
3295 ETEXI
3297 DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3298 "-realtime [mlock=on|off]\n"
3299 " run qemu with realtime features\n"
3300 " mlock=on|off controls mlock support (default: on)\n",
3301 QEMU_ARCH_ALL)
3302 STEXI
3303 @item -realtime mlock=on|off
3304 @findex -realtime
3305 Run qemu with realtime features.
3306 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3307 (enabled by default).
3308 ETEXI
3310 DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3311 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3312 STEXI
3313 @item -gdb @var{dev}
3314 @findex -gdb
3315 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3316 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3317 stdio are reasonable use case. The latter is allowing to start QEMU from
3318 within gdb and establish the connection via a pipe:
3319 @example
3320 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3321 @end example
3322 ETEXI
3324 DEF("s", 0, QEMU_OPTION_s, \
3325 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3326 QEMU_ARCH_ALL)
3327 STEXI
3328 @item -s
3329 @findex -s
3330 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3331 (@pxref{gdb_usage}).
3332 ETEXI
3334 DEF("d", HAS_ARG, QEMU_OPTION_d, \
3335 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
3336 QEMU_ARCH_ALL)
3337 STEXI
3338 @item -d @var{item1}[,...]
3339 @findex -d
3340 Enable logging of specified items. Use '-d help' for a list of log items.
3341 ETEXI
3343 DEF("D", HAS_ARG, QEMU_OPTION_D, \
3344 "-D logfile output log to logfile (default stderr)\n",
3345 QEMU_ARCH_ALL)
3346 STEXI
3347 @item -D @var{logfile}
3348 @findex -D
3349 Output log in @var{logfile} instead of to stderr
3350 ETEXI
3352 DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3353 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3354 QEMU_ARCH_ALL)
3355 STEXI
3356 @item -dfilter @var{range1}[,...]
3357 @findex -dfilter
3358 Filter debug output to that relevant to a range of target addresses. The filter
3359 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3360 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3361 addresses and sizes required. For example:
3362 @example
3363 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3364 @end example
3365 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3366 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3367 block starting at 0xffffffc00005f000.
3368 ETEXI
3370 DEF("L", HAS_ARG, QEMU_OPTION_L, \
3371 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
3372 QEMU_ARCH_ALL)
3373 STEXI
3374 @item -L @var{path}
3375 @findex -L
3376 Set the directory for the BIOS, VGA BIOS and keymaps.
3378 To list all the data directories, use @code{-L help}.
3379 ETEXI
3381 DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3382 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
3383 STEXI
3384 @item -bios @var{file}
3385 @findex -bios
3386 Set the filename for the BIOS.
3387 ETEXI
3389 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3390 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3391 STEXI
3392 @item -enable-kvm
3393 @findex -enable-kvm
3394 Enable KVM full virtualization support. This option is only available
3395 if KVM support is enabled when compiling.
3396 ETEXI
3398 DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3399 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386)
3400 STEXI
3401 @item -enable-hax
3402 @findex -enable-hax
3403 Enable HAX (Hardware-based Acceleration eXecution) support. This option
3404 is only available if HAX support is enabled when compiling. HAX is only
3405 applicable to MAC and Windows platform, and thus does not conflict with
3406 KVM.
3407 ETEXI
3409 DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3410 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
3411 DEF("xen-create", 0, QEMU_OPTION_xen_create,
3412 "-xen-create create domain using xen hypercalls, bypassing xend\n"
3413 " warning: should not be used when xend is in use\n",
3414 QEMU_ARCH_ALL)
3415 DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3416 "-xen-attach attach to existing xen domain\n"
3417 " xend will use this when starting QEMU\n",
3418 QEMU_ARCH_ALL)
3419 DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3420 "-xen-domid-restrict restrict set of available xen operations\n"
3421 " to specified domain id. (Does not affect\n"
3422 " xenpv machine type).\n",
3423 QEMU_ARCH_ALL)
3424 STEXI
3425 @item -xen-domid @var{id}
3426 @findex -xen-domid
3427 Specify xen guest domain @var{id} (XEN only).
3428 @item -xen-create
3429 @findex -xen-create
3430 Create domain using xen hypercalls, bypassing xend.
3431 Warning: should not be used when xend is in use (XEN only).
3432 @item -xen-attach
3433 @findex -xen-attach
3434 Attach to existing xen domain.
3435 xend will use this when starting QEMU (XEN only).
3436 @findex -xen-domid-restrict
3437 Restrict set of available xen operations to specified domain id (XEN only).
3438 ETEXI
3440 DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3441 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
3442 STEXI
3443 @item -no-reboot
3444 @findex -no-reboot
3445 Exit instead of rebooting.
3446 ETEXI
3448 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3449 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
3450 STEXI
3451 @item -no-shutdown
3452 @findex -no-shutdown
3453 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3454 This allows for instance switching to monitor to commit changes to the
3455 disk image.
3456 ETEXI
3458 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3459 "-loadvm [tag|id]\n" \
3460 " start right away with a saved state (loadvm in monitor)\n",
3461 QEMU_ARCH_ALL)
3462 STEXI
3463 @item -loadvm @var{file}
3464 @findex -loadvm
3465 Start right away with a saved state (@code{loadvm} in monitor)
3466 ETEXI
3468 #ifndef _WIN32
3469 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3470 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3471 #endif
3472 STEXI
3473 @item -daemonize
3474 @findex -daemonize
3475 Daemonize the QEMU process after initialization. QEMU will not detach from
3476 standard IO until it is ready to receive connections on any of its devices.
3477 This option is a useful way for external programs to launch QEMU without having
3478 to cope with initialization race conditions.
3479 ETEXI
3481 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3482 "-option-rom rom load a file, rom, into the option ROM space\n",
3483 QEMU_ARCH_ALL)
3484 STEXI
3485 @item -option-rom @var{file}
3486 @findex -option-rom
3487 Load the contents of @var{file} as an option ROM.
3488 This option is useful to load things like EtherBoot.
3489 ETEXI
3491 HXCOMM Silently ignored for compatibility
3492 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3494 HXCOMM Options deprecated by -rtc
3495 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3496 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3498 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3499 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3500 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3501 QEMU_ARCH_ALL)
3503 STEXI
3505 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3506 @findex -rtc
3507 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3508 UTC or local time, respectively. @code{localtime} is required for correct date in
3509 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3510 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3512 By default the RTC is driven by the host system time. This allows using of the
3513 RTC as accurate reference clock inside the guest, specifically if the host
3514 time is smoothly following an accurate external reference clock, e.g. via NTP.
3515 If you want to isolate the guest time from the host, you can set @option{clock}
3516 to @code{rt} instead. To even prevent it from progressing during suspension,
3517 you can set it to @code{vm}.
3519 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3520 specifically with Windows' ACPI HAL. This option will try to figure out how
3521 many timer interrupts were not processed by the Windows guest and will
3522 re-inject them.
3523 ETEXI
3525 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3526 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3527 " enable virtual instruction counter with 2^N clock ticks per\n" \
3528 " instruction, enable aligning the host and virtual clocks\n" \
3529 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3530 STEXI
3531 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3532 @findex -icount
3533 Enable virtual instruction counter. The virtual cpu will execute one
3534 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3535 then the virtual cpu speed will be automatically adjusted to keep virtual
3536 time within a few seconds of real time.
3538 When the virtual cpu is sleeping, the virtual time will advance at default
3539 speed unless @option{sleep=on|off} is specified.
3540 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3541 instantly whenever the virtual cpu goes to sleep mode and will not advance
3542 if no timer is enabled. This behavior give deterministic execution times from
3543 the guest point of view.
3545 Note that while this option can give deterministic behavior, it does not
3546 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3547 order cores with complex cache hierarchies. The number of instructions
3548 executed often has little or no correlation with actual performance.
3550 @option{align=on} will activate the delay algorithm which will try
3551 to synchronise the host clock and the virtual clock. The goal is to
3552 have a guest running at the real frequency imposed by the shift option.
3553 Whenever the guest clock is behind the host clock and if
3554 @option{align=on} is specified then we print a message to the user
3555 to inform about the delay.
3556 Currently this option does not work when @option{shift} is @code{auto}.
3557 Note: The sync algorithm will work for those shift values for which
3558 the guest clock runs ahead of the host clock. Typically this happens
3559 when the shift value is high (how high depends on the host machine).
3561 When @option{rr} option is specified deterministic record/replay is enabled.
3562 Replay log is written into @var{filename} file in record mode and
3563 read from this file in replay mode.
3565 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3566 at the start of execution recording. In replay mode this option is used
3567 to load the initial VM state.
3568 ETEXI
3570 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3571 "-watchdog model\n" \
3572 " enable virtual hardware watchdog [default=none]\n",
3573 QEMU_ARCH_ALL)
3574 STEXI
3575 @item -watchdog @var{model}
3576 @findex -watchdog
3577 Create a virtual hardware watchdog device. Once enabled (by a guest
3578 action), the watchdog must be periodically polled by an agent inside
3579 the guest or else the guest will be restarted. Choose a model for
3580 which your guest has drivers.
3582 The @var{model} is the model of hardware watchdog to emulate. Use
3583 @code{-watchdog help} to list available hardware models. Only one
3584 watchdog can be enabled for a guest.
3586 The following models may be available:
3587 @table @option
3588 @item ib700
3589 iBASE 700 is a very simple ISA watchdog with a single timer.
3590 @item i6300esb
3591 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3592 dual-timer watchdog.
3593 @item diag288
3594 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3595 (currently KVM only).
3596 @end table
3597 ETEXI
3599 DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3600 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3601 " action when watchdog fires [default=reset]\n",
3602 QEMU_ARCH_ALL)
3603 STEXI
3604 @item -watchdog-action @var{action}
3605 @findex -watchdog-action
3607 The @var{action} controls what QEMU will do when the watchdog timer
3608 expires.
3609 The default is
3610 @code{reset} (forcefully reset the guest).
3611 Other possible actions are:
3612 @code{shutdown} (attempt to gracefully shutdown the guest),
3613 @code{poweroff} (forcefully poweroff the guest),
3614 @code{inject-nmi} (inject a NMI into the guest),
3615 @code{pause} (pause the guest),
3616 @code{debug} (print a debug message and continue), or
3617 @code{none} (do nothing).
3619 Note that the @code{shutdown} action requires that the guest responds
3620 to ACPI signals, which it may not be able to do in the sort of
3621 situations where the watchdog would have expired, and thus
3622 @code{-watchdog-action shutdown} is not recommended for production use.
3624 Examples:
3626 @table @code
3627 @item -watchdog i6300esb -watchdog-action pause
3628 @itemx -watchdog ib700
3629 @end table
3630 ETEXI
3632 DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3633 "-echr chr set terminal escape character instead of ctrl-a\n",
3634 QEMU_ARCH_ALL)
3635 STEXI
3637 @item -echr @var{numeric_ascii_value}
3638 @findex -echr
3639 Change the escape character used for switching to the monitor when using
3640 monitor and serial sharing. The default is @code{0x01} when using the
3641 @code{-nographic} option. @code{0x01} is equal to pressing
3642 @code{Control-a}. You can select a different character from the ascii
3643 control keys where 1 through 26 map to Control-a through Control-z. For
3644 instance you could use the either of the following to change the escape
3645 character to Control-t.
3646 @table @code
3647 @item -echr 0x14
3648 @itemx -echr 20
3649 @end table
3650 ETEXI
3652 DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3653 "-virtioconsole c\n" \
3654 " set virtio console\n", QEMU_ARCH_ALL)
3655 STEXI
3656 @item -virtioconsole @var{c}
3657 @findex -virtioconsole
3658 Set virtio console.
3660 This option is maintained for backward compatibility.
3662 Please use @code{-device virtconsole} for the new way of invocation.
3663 ETEXI
3665 DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3666 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
3667 STEXI
3668 @item -show-cursor
3669 @findex -show-cursor
3670 Show cursor.
3671 ETEXI
3673 DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3674 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
3675 STEXI
3676 @item -tb-size @var{n}
3677 @findex -tb-size
3678 Set TB size.
3679 ETEXI
3681 DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3682 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3683 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3684 "-incoming unix:socketpath\n" \
3685 " prepare for incoming migration, listen on\n" \
3686 " specified protocol and socket address\n" \
3687 "-incoming fd:fd\n" \
3688 "-incoming exec:cmdline\n" \
3689 " accept incoming migration on given file descriptor\n" \
3690 " or from given external command\n" \
3691 "-incoming defer\n" \
3692 " wait for the URI to be specified via migrate_incoming\n",
3693 QEMU_ARCH_ALL)
3694 STEXI
3695 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3696 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3697 @findex -incoming
3698 Prepare for incoming migration, listen on a given tcp port.
3700 @item -incoming unix:@var{socketpath}
3701 Prepare for incoming migration, listen on a given unix socket.
3703 @item -incoming fd:@var{fd}
3704 Accept incoming migration from a given filedescriptor.
3706 @item -incoming exec:@var{cmdline}
3707 Accept incoming migration as an output from specified external command.
3709 @item -incoming defer
3710 Wait for the URI to be specified via migrate_incoming. The monitor can
3711 be used to change settings (such as migration parameters) prior to issuing
3712 the migrate_incoming to allow the migration to begin.
3713 ETEXI
3715 DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3716 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
3717 STEXI
3718 @item -only-migratable
3719 @findex -only-migratable
3720 Only allow migratable devices. Devices will not be allowed to enter an
3721 unmigratable state.
3722 ETEXI
3724 DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3725 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
3726 STEXI
3727 @item -nodefaults
3728 @findex -nodefaults
3729 Don't create default devices. Normally, QEMU sets the default devices like serial
3730 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3731 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3732 default devices.
3733 ETEXI
3735 #ifndef _WIN32
3736 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3737 "-chroot dir chroot to dir just before starting the VM\n",
3738 QEMU_ARCH_ALL)
3739 #endif
3740 STEXI
3741 @item -chroot @var{dir}
3742 @findex -chroot
3743 Immediately before starting guest execution, chroot to the specified
3744 directory. Especially useful in combination with -runas.
3745 ETEXI
3747 #ifndef _WIN32
3748 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3749 "-runas user change to user id user just before starting the VM\n",
3750 QEMU_ARCH_ALL)
3751 #endif
3752 STEXI
3753 @item -runas @var{user}
3754 @findex -runas
3755 Immediately before starting guest execution, drop root privileges, switching
3756 to the specified user.
3757 ETEXI
3759 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3760 "-prom-env variable=value\n"
3761 " set OpenBIOS nvram variables\n",
3762 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3763 STEXI
3764 @item -prom-env @var{variable}=@var{value}
3765 @findex -prom-env
3766 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3767 ETEXI
3768 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3769 "-semihosting semihosting mode\n",
3770 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3771 QEMU_ARCH_MIPS)
3772 STEXI
3773 @item -semihosting
3774 @findex -semihosting
3775 Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3776 ETEXI
3777 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3778 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3779 " semihosting configuration\n",
3780 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3781 QEMU_ARCH_MIPS)
3782 STEXI
3783 @item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3784 @findex -semihosting-config
3785 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3786 @table @option
3787 @item target=@code{native|gdb|auto}
3788 Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3789 or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3790 during debug sessions and @code{native} otherwise.
3791 @item arg=@var{str1},arg=@var{str2},...
3792 Allows the user to pass input arguments, and can be used multiple times to build
3793 up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3794 command line is still supported for backward compatibility. If both the
3795 @code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3796 specified, the former is passed to semihosting as it always takes precedence.
3797 @end table
3798 ETEXI
3799 DEF("old-param", 0, QEMU_OPTION_old_param,
3800 "-old-param old param mode\n", QEMU_ARCH_ARM)
3801 STEXI
3802 @item -old-param
3803 @findex -old-param (ARM)
3804 Old param mode (ARM only).
3805 ETEXI
3807 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3808 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3809 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3810 " Enable seccomp mode 2 system call filter (default 'off').\n" \
3811 " use 'obsolete' to allow obsolete system calls that are provided\n" \
3812 " by the kernel, but typically no longer used by modern\n" \
3813 " C library implementations.\n" \
3814 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3815 " its privileges by blacklisting all set*uid|gid system calls.\n" \
3816 " The value 'children' will deny set*uid|gid system calls for\n" \
3817 " main QEMU process but will allow forks and execves to run unprivileged\n" \
3818 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3819 " blacklisting *fork and execve\n" \
3820 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
3821 QEMU_ARCH_ALL)
3822 STEXI
3823 @item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3824 @findex -sandbox
3825 Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3826 disable it. The default is 'off'.
3827 @table @option
3828 @item obsolete=@var{string}
3829 Enable Obsolete system calls
3830 @item elevateprivileges=@var{string}
3831 Disable set*uid|gid system calls
3832 @item spawn=@var{string}
3833 Disable *fork and execve
3834 @item resourcecontrol=@var{string}
3835 Disable process affinity and schedular priority
3836 @end table
3837 ETEXI
3839 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3840 "-readconfig <file>\n", QEMU_ARCH_ALL)
3841 STEXI
3842 @item -readconfig @var{file}
3843 @findex -readconfig
3844 Read device configuration from @var{file}. This approach is useful when you want to spawn
3845 QEMU process with many command line options but you don't want to exceed the command line
3846 character limit.
3847 ETEXI
3848 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3849 "-writeconfig <file>\n"
3850 " read/write config file\n", QEMU_ARCH_ALL)
3851 STEXI
3852 @item -writeconfig @var{file}
3853 @findex -writeconfig
3854 Write device configuration to @var{file}. The @var{file} can be either filename to save
3855 command line and device configuration into file or dash @code{-}) character to print the
3856 output to stdout. This can be later used as input file for @code{-readconfig} option.
3857 ETEXI
3858 HXCOMM Deprecated, same as -no-user-config
3859 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
3860 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3861 "-no-user-config\n"
3862 " do not load default user-provided config files at startup\n",
3863 QEMU_ARCH_ALL)
3864 STEXI
3865 @item -no-user-config
3866 @findex -no-user-config
3867 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3868 config files on @var{sysconfdir}.
3869 ETEXI
3870 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3871 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3872 " specify tracing options\n",
3873 QEMU_ARCH_ALL)
3874 STEXI
3875 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3876 HXCOMM HX does not support conditional compilation of text.
3877 @item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3878 @findex -trace
3879 @include qemu-option-trace.texi
3880 ETEXI
3882 HXCOMM Internal use
3883 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3884 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3886 #ifdef __linux__
3887 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3888 "-enable-fips enable FIPS 140-2 compliance\n",
3889 QEMU_ARCH_ALL)
3890 #endif
3891 STEXI
3892 @item -enable-fips
3893 @findex -enable-fips
3894 Enable FIPS 140-2 compliance mode.
3895 ETEXI
3897 HXCOMM Deprecated by -machine accel=tcg property
3898 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3900 HXCOMM Deprecated by kvm-pit driver properties
3901 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3902 "", QEMU_ARCH_I386)
3904 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3905 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3907 HXCOMM Deprecated (ignored)
3908 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3910 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3911 "-msg timestamp[=on|off]\n"
3912 " change the format of messages\n"
3913 " on|off controls leading timestamps (default:on)\n",
3914 QEMU_ARCH_ALL)
3915 STEXI
3916 @item -msg timestamp[=on|off]
3917 @findex -msg
3918 prepend a timestamp to each log message.(default:on)
3919 ETEXI
3921 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3922 "-dump-vmstate <file>\n"
3923 " Output vmstate information in JSON format to file.\n"
3924 " Use the scripts/vmstate-static-checker.py file to\n"
3925 " check for possible regressions in migration code\n"
3926 " by comparing two such vmstate dumps.\n",
3927 QEMU_ARCH_ALL)
3928 STEXI
3929 @item -dump-vmstate @var{file}
3930 @findex -dump-vmstate
3931 Dump json-encoded vmstate information for current machine type to file
3932 in @var{file}
3933 ETEXI
3935 STEXI
3936 @end table
3937 ETEXI
3938 DEFHEADING()
3940 DEFHEADING(Generic object creation:)
3941 STEXI
3942 @table @option
3943 ETEXI
3945 DEF("object", HAS_ARG, QEMU_OPTION_object,
3946 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3947 " create a new object of type TYPENAME setting properties\n"
3948 " in the order they are specified. Note that the 'id'\n"
3949 " property must be set. These objects are placed in the\n"
3950 " '/objects' path.\n",
3951 QEMU_ARCH_ALL)
3952 STEXI
3953 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3954 @findex -object
3955 Create a new object of type @var{typename} setting properties
3956 in the order they are specified. Note that the 'id'
3957 property must be set. These objects are placed in the
3958 '/objects' path.
3960 @table @option
3962 @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}
3964 Creates a memory file backend object, which can be used to back
3965 the guest RAM with huge pages.
3967 The @option{id} parameter is a unique ID that will be used to reference this
3968 memory region when configuring the @option{-numa} argument.
3970 The @option{size} option provides the size of the memory region, and accepts
3971 common suffixes, eg @option{500M}.
3973 The @option{mem-path} provides the path to either a shared memory or huge page
3974 filesystem mount.
3976 The @option{share} boolean option determines whether the memory
3977 region is marked as private to QEMU, or shared. The latter allows
3978 a co-operating external process to access the QEMU memory region.
3980 The @option{share} is also required for pvrdma devices due to
3981 limitations in the RDMA API provided by Linux.
3983 Setting share=on might affect the ability to configure NUMA
3984 bindings for the memory backend under some circumstances, see
3985 Documentation/vm/numa_memory_policy.txt on the Linux kernel
3986 source tree for additional details.
3988 Setting the @option{discard-data} boolean option to @var{on}
3989 indicates that file contents can be destroyed when QEMU exits,
3990 to avoid unnecessarily flushing data to the backing file. Note
3991 that @option{discard-data} is only an optimization, and QEMU
3992 might not discard file contents if it aborts unexpectedly or is
3993 terminated using SIGKILL.
3995 The @option{merge} boolean option enables memory merge, also known as
3996 MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
3997 memory deduplication.
3999 Setting the @option{dump} boolean option to @var{off} excludes the memory from
4000 core dumps. This feature is also known as MADV_DONTDUMP.
4002 The @option{prealloc} boolean option enables memory preallocation.
4004 The @option{host-nodes} option binds the memory range to a list of NUMA host
4005 nodes.
4007 The @option{policy} option sets the NUMA policy to one of the following values:
4009 @table @option
4010 @item @var{default}
4011 default host policy
4013 @item @var{preferred}
4014 prefer the given host node list for allocation
4016 @item @var{bind}
4017 restrict memory allocation to the given host node list
4019 @item @var{interleave}
4020 interleave memory allocations across the given host node list
4021 @end table
4023 The @option{align} option specifies the base address alignment when
4024 QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
4025 @option{2M}. Some backend store specified by @option{mem-path}
4026 requires an alignment different than the default one used by QEMU, eg
4027 the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4028 such cases, users can specify the required alignment via this option.
4030 @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}
4032 Creates a memory backend object, which can be used to back the guest RAM.
4033 Memory backend objects offer more control than the @option{-m} option that is
4034 traditionally used to define guest RAM. Please refer to
4035 @option{memory-backend-file} for a description of the options.
4037 @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}
4039 Creates an anonymous memory file backend object, which allows QEMU to
4040 share the memory with an external process (e.g. when using
4041 vhost-user). The memory is allocated with memfd and optional
4042 sealing. (Linux only)
4044 The @option{seal} option creates a sealed-file, that will block
4045 further resizing the memory ('on' by default).
4047 The @option{hugetlb} option specify the file to be created resides in
4048 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with
4049 the @option{hugetlb} option, the @option{hugetlbsize} option specify
4050 the hugetlb page size on systems that support multiple hugetlb page
4051 sizes (it must be a power of 2 value supported by the system).
4053 In some versions of Linux, the @option{hugetlb} option is incompatible
4054 with the @option{seal} option (requires at least Linux 4.16).
4056 Please refer to @option{memory-backend-file} for a description of the
4057 other options.
4059 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
4061 Creates a random number generator backend which obtains entropy from
4062 a device on the host. The @option{id} parameter is a unique ID that
4063 will be used to reference this entropy backend from the @option{virtio-rng}
4064 device. The @option{filename} parameter specifies which file to obtain
4065 entropy from and if omitted defaults to @option{/dev/random}.
4067 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4069 Creates a random number generator backend which obtains entropy from
4070 an external daemon running on the host. The @option{id} parameter is
4071 a unique ID that will be used to reference this entropy backend from
4072 the @option{virtio-rng} device. The @option{chardev} parameter is
4073 the unique ID of a character device backend that provides the connection
4074 to the RNG daemon.
4076 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4078 Creates a TLS anonymous credentials object, which can be used to provide
4079 TLS support on network backends. The @option{id} parameter is a unique
4080 ID which network backends will use to access the credentials. The
4081 @option{endpoint} is either @option{server} or @option{client} depending
4082 on whether the QEMU network backend that uses the credentials will be
4083 acting as a client or as a server. If @option{verify-peer} is enabled
4084 (the default) then once the handshake is completed, the peer credentials
4085 will be verified, though this is a no-op for anonymous credentials.
4087 The @var{dir} parameter tells QEMU where to find the credential
4088 files. For server endpoints, this directory may contain a file
4089 @var{dh-params.pem} providing diffie-hellman parameters to use
4090 for the TLS server. If the file is missing, QEMU will generate
4091 a set of DH parameters at startup. This is a computationally
4092 expensive operation that consumes random pool entropy, so it is
4093 recommended that a persistent set of parameters be generated
4094 upfront and saved.
4096 @item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off},passwordid=@var{id}
4098 Creates a TLS anonymous credentials object, which can be used to provide
4099 TLS support on network backends. The @option{id} parameter is a unique
4100 ID which network backends will use to access the credentials. The
4101 @option{endpoint} is either @option{server} or @option{client} depending
4102 on whether the QEMU network backend that uses the credentials will be
4103 acting as a client or as a server. If @option{verify-peer} is enabled
4104 (the default) then once the handshake is completed, the peer credentials
4105 will be verified. With x509 certificates, this implies that the clients
4106 must be provided with valid client certificates too.
4108 The @var{dir} parameter tells QEMU where to find the credential
4109 files. For server endpoints, this directory may contain a file
4110 @var{dh-params.pem} providing diffie-hellman parameters to use
4111 for the TLS server. If the file is missing, QEMU will generate
4112 a set of DH parameters at startup. This is a computationally
4113 expensive operation that consumes random pool entropy, so it is
4114 recommended that a persistent set of parameters be generated
4115 upfront and saved.
4117 For x509 certificate credentials the directory will contain further files
4118 providing the x509 certificates. The certificates must be stored
4119 in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4120 @var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4121 @var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4123 For the @var{server-key.pem} and @var{client-key.pem} files which
4124 contain sensitive private keys, it is possible to use an encrypted
4125 version by providing the @var{passwordid} parameter. This provides
4126 the ID of a previously created @code{secret} object containing the
4127 password for decryption.
4129 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4131 Interval @var{t} can't be 0, this filter batches the packet delivery: all
4132 packets arriving in a given interval on netdev @var{netdevid} are delayed
4133 until the end of the interval. Interval is in microseconds.
4134 @option{status} is optional that indicate whether the netfilter is
4135 on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4137 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4139 @option{all}: the filter is attached both to the receive and the transmit
4140 queue of the netdev (default).
4142 @option{rx}: the filter is attached to the receive queue of the netdev,
4143 where it will receive packets sent to the netdev.
4145 @option{tx}: the filter is attached to the transmit queue of the netdev,
4146 where it will receive packets sent by the netdev.
4148 @item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4150 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.
4152 @item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4154 filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4155 @var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4156 filter-redirector will redirect packet with vnet_hdr_len.
4157 Create a filter-redirector we need to differ outdev id from indev id, id can not
4158 be the same. we can just use indev or outdev, but at least one of indev or outdev
4159 need to be specified.
4161 @item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4163 Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4164 secondary from primary to keep secondary tcp connection,and rewrite
4165 tcp packet to primary from secondary make tcp packet can be handled by
4166 client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4168 usage:
4169 colo secondary:
4170 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4171 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4172 -object filter-rewriter,id=rew0,netdev=hn0,queue=all
4174 @item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4176 Dump the network traffic on netdev @var{dev} to the file specified by
4177 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4178 The file format is libpcap, so it can be analyzed with tools such as tcpdump
4179 or Wireshark.
4181 @item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4183 Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4184 secondary packet. If the packets are same, we will output primary
4185 packet to outdev@var{chardevid}, else we will notify colo-frame
4186 do checkpoint and send primary packet to outdev@var{chardevid}.
4187 if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4189 we must use it with the help of filter-mirror and filter-redirector.
4191 @example
4193 primary:
4194 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4195 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4196 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4197 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4198 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4199 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4200 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4201 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4202 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4203 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4204 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4205 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4207 secondary:
4208 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4209 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4210 -chardev socket,id=red0,host=3.3.3.3,port=9003
4211 -chardev socket,id=red1,host=3.3.3.3,port=9004
4212 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4213 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4215 @end example
4217 If you want to know the detail of above command line, you can read
4218 the colo-compare git log.
4220 @item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4222 Creates a cryptodev backend which executes crypto opreation from
4223 the QEMU cipher APIS. The @var{id} parameter is
4224 a unique ID that will be used to reference this cryptodev backend from
4225 the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4226 which specify the queue number of cryptodev backend, the default of
4227 @var{queues} is 1.
4229 @example
4231 # qemu-system-x86_64 \
4232 [...] \
4233 -object cryptodev-backend-builtin,id=cryptodev0 \
4234 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4235 [...]
4236 @end example
4238 @item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4240 Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4241 The @var{id} parameter is a unique ID that will be used to reference this
4242 cryptodev backend from the @option{virtio-crypto} device.
4243 The chardev should be a unix domain socket backed one. The vhost-user uses
4244 a specifically defined protocol to pass vhost ioctl replacement messages
4245 to an application on the other end of the socket.
4246 The @var{queues} parameter is optional, which specify the queue number
4247 of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4249 @example
4251 # qemu-system-x86_64 \
4252 [...] \
4253 -chardev socket,id=chardev0,path=/path/to/socket \
4254 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4255 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4256 [...]
4257 @end example
4259 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4260 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4262 Defines a secret to store a password, encryption key, or some other sensitive
4263 data. The sensitive data can either be passed directly via the @var{data}
4264 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4265 parameter is insecure unless the sensitive data is encrypted.
4267 The sensitive data can be provided in raw format (the default), or base64.
4268 When encoded as JSON, the raw format only supports valid UTF-8 characters,
4269 so base64 is recommended for sending binary data. QEMU will convert from
4270 which ever format is provided to the format it needs internally. eg, an
4271 RBD password can be provided in raw format, even though it will be base64
4272 encoded when passed onto the RBD sever.
4274 For added protection, it is possible to encrypt the data associated with
4275 a secret using the AES-256-CBC cipher. Use of encryption is indicated
4276 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4277 parameter provides the ID of a previously defined secret that contains
4278 the AES-256 decryption key. This key should be 32-bytes long and be
4279 base64 encoded. The @var{iv} parameter provides the random initialization
4280 vector used for encryption of this particular secret and should be a
4281 base64 encrypted string of the 16-byte IV.
4283 The simplest (insecure) usage is to provide the secret inline
4285 @example
4287 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4289 @end example
4291 The simplest secure usage is to provide the secret via a file
4293 # printf "letmein" > mypasswd.txt
4294 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4296 For greater security, AES-256-CBC should be used. To illustrate usage,
4297 consider the openssl command line tool which can encrypt the data. Note
4298 that when encrypting, the plaintext must be padded to the cipher block
4299 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4301 First a master key needs to be created in base64 encoding:
4303 @example
4304 # openssl rand -base64 32 > key.b64
4305 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
4306 @end example
4308 Each secret to be encrypted needs to have a random initialization vector
4309 generated. These do not need to be kept secret
4311 @example
4312 # openssl rand -base64 16 > iv.b64
4313 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
4314 @end example
4316 The secret to be defined can now be encrypted, in this case we're
4317 telling openssl to base64 encode the result, but it could be left
4318 as raw bytes if desired.
4320 @example
4321 # SECRET=$(printf "letmein" |
4322 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4323 @end example
4325 When launching QEMU, create a master secret pointing to @code{key.b64}
4326 and specify that to be used to decrypt the user password. Pass the
4327 contents of @code{iv.b64} to the second secret
4329 @example
4330 # $QEMU \
4331 -object secret,id=secmaster0,format=base64,file=key.b64 \
4332 -object secret,id=sec0,keyid=secmaster0,format=base64,\
4333 data=$SECRET,iv=$(<iv.b64)
4334 @end example
4336 @end table
4338 ETEXI
4341 HXCOMM This is the last statement. Insert new options before this line!
4342 STEXI
4343 @end table
4344 ETEXI