migration: add postcopy migration of dirty bitmaps
[qemu/kevin.git] / qemu-options.hx
blob6585058c6cded02f1c18607afb7e782217100875
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 virtio[,addr=str]\n"
466 " enable virtio balloon device (deprecated)\n", QEMU_ARCH_ALL)
467 STEXI
468 @item -balloon virtio[,addr=@var{addr}]
469 @findex -balloon
470 Enable virtio balloon device, optionally with PCI address @var{addr}. This
471 option is deprecated, use @option{--device virtio-balloon} instead.
472 ETEXI
474 DEF("device", HAS_ARG, QEMU_OPTION_device,
475 "-device driver[,prop[=value][,...]]\n"
476 " add device (based on driver)\n"
477 " prop=value,... sets driver properties\n"
478 " use '-device help' to print all possible drivers\n"
479 " use '-device driver,help' to print all possible properties\n",
480 QEMU_ARCH_ALL)
481 STEXI
482 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
483 @findex -device
484 Add device @var{driver}. @var{prop}=@var{value} sets driver
485 properties. Valid properties depend on the driver. To get help on
486 possible drivers and properties, use @code{-device help} and
487 @code{-device @var{driver},help}.
489 Some drivers are:
490 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
492 Add an IPMI BMC. This is a simulation of a hardware management
493 interface processor that normally sits on a system. It provides
494 a watchdog and the ability to reset and power control the system.
495 You need to connect this to an IPMI interface to make it useful
497 The IPMI slave address to use for the BMC. The default is 0x20.
498 This address is the BMC's address on the I2C network of management
499 controllers. If you don't know what this means, it is safe to ignore
502 @table @option
503 @item bmc=@var{id}
504 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
505 @item slave_addr=@var{val}
506 Define slave address to use for the BMC. The default is 0x20.
507 @item sdrfile=@var{file}
508 file containing raw Sensor Data Records (SDR) data. The default is none.
509 @item fruareasize=@var{val}
510 size of a Field Replaceable Unit (FRU) area. The default is 1024.
511 @item frudatafile=@var{file}
512 file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
513 @end table
515 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
517 Add a connection to an external IPMI BMC simulator. Instead of
518 locally emulating the BMC like the above item, instead connect
519 to an external entity that provides the IPMI services.
521 A connection is made to an external BMC simulator. If you do this, it
522 is strongly recommended that you use the "reconnect=" chardev option
523 to reconnect to the simulator if the connection is lost. Note that if
524 this is not used carefully, it can be a security issue, as the
525 interface has the ability to send resets, NMIs, and power off the VM.
526 It's best if QEMU makes a connection to an external simulator running
527 on a secure port on localhost, so neither the simulator nor QEMU is
528 exposed to any outside network.
530 See the "lanserv/README.vm" file in the OpenIPMI library for more
531 details on the external interface.
533 @item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
535 Add a KCS IPMI interafce on the ISA bus. This also adds a
536 corresponding ACPI and SMBIOS entries, if appropriate.
538 @table @option
539 @item bmc=@var{id}
540 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
541 @item ioport=@var{val}
542 Define the I/O address of the interface. The default is 0xca0 for KCS.
543 @item irq=@var{val}
544 Define the interrupt to use. The default is 5. To disable interrupts,
545 set this to 0.
546 @end table
548 @item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
550 Like the KCS interface, but defines a BT interface. The default port is
551 0xe4 and the default interrupt is 5.
553 ETEXI
555 DEF("name", HAS_ARG, QEMU_OPTION_name,
556 "-name string1[,process=string2][,debug-threads=on|off]\n"
557 " set the name of the guest\n"
558 " string1 sets the window title and string2 the process name (on Linux)\n"
559 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
560 " NOTE: The thread names are for debugging and not a stable API.\n",
561 QEMU_ARCH_ALL)
562 STEXI
563 @item -name @var{name}
564 @findex -name
565 Sets the @var{name} of the guest.
566 This name will be displayed in the SDL window caption.
567 The @var{name} will also be used for the VNC server.
568 Also optionally set the top visible process name in Linux.
569 Naming of individual threads can also be enabled on Linux to aid debugging.
570 ETEXI
572 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
573 "-uuid %08x-%04x-%04x-%04x-%012x\n"
574 " specify machine UUID\n", QEMU_ARCH_ALL)
575 STEXI
576 @item -uuid @var{uuid}
577 @findex -uuid
578 Set system UUID.
579 ETEXI
581 STEXI
582 @end table
583 ETEXI
584 DEFHEADING()
586 DEFHEADING(Block device options:)
587 STEXI
588 @table @option
589 ETEXI
591 DEF("fda", HAS_ARG, QEMU_OPTION_fda,
592 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
593 DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
594 STEXI
595 @item -fda @var{file}
596 @itemx -fdb @var{file}
597 @findex -fda
598 @findex -fdb
599 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
600 ETEXI
602 DEF("hda", HAS_ARG, QEMU_OPTION_hda,
603 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
604 DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
605 DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
606 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
607 DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
608 STEXI
609 @item -hda @var{file}
610 @itemx -hdb @var{file}
611 @itemx -hdc @var{file}
612 @itemx -hdd @var{file}
613 @findex -hda
614 @findex -hdb
615 @findex -hdc
616 @findex -hdd
617 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
618 ETEXI
620 DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
621 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
622 QEMU_ARCH_ALL)
623 STEXI
624 @item -cdrom @var{file}
625 @findex -cdrom
626 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
627 @option{-cdrom} at the same time). You can use the host CD-ROM by
628 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
629 ETEXI
631 DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
632 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
633 " [,cache.direct=on|off][,cache.no-flush=on|off]\n"
634 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
635 " [,driver specific parameters...]\n"
636 " configure a block backend\n", QEMU_ARCH_ALL)
637 STEXI
638 @item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
639 @findex -blockdev
641 Define a new block driver node. Some of the options apply to all block drivers,
642 other options are only accepted for a specific block driver. See below for a
643 list of generic options and options for the most common block drivers.
645 Options that expect a reference to another node (e.g. @code{file}) can be
646 given in two ways. Either you specify the node name of an already existing node
647 (file=@var{node-name}), or you define a new node inline, adding options
648 for the referenced node after a dot (file.filename=@var{path},file.aio=native).
650 A block driver node created with @option{-blockdev} can be used for a guest
651 device by specifying its node name for the @code{drive} property in a
652 @option{-device} argument that defines a block device.
654 @table @option
655 @item Valid options for any block driver node:
657 @table @code
658 @item driver
659 Specifies the block driver to use for the given node.
660 @item node-name
661 This defines the name of the block driver node by which it will be referenced
662 later. The name must be unique, i.e. it must not match the name of a different
663 block driver node, or (if you use @option{-drive} as well) the ID of a drive.
665 If no node name is specified, it is automatically generated. The generated node
666 name is not intended to be predictable and changes between QEMU invocations.
667 For the top level, an explicit node name must be specified.
668 @item read-only
669 Open the node read-only. Guest write attempts will fail.
670 @item cache.direct
671 The host page cache can be avoided with @option{cache.direct=on}. This will
672 attempt to do disk IO directly to the guest's memory. QEMU may still perform an
673 internal copy of the data.
674 @item cache.no-flush
675 In case you don't care about data integrity over host failures, you can use
676 @option{cache.no-flush=on}. This option tells QEMU that it never needs to write
677 any data to the disk but can instead keep things in cache. If anything goes
678 wrong, like your host losing power, the disk storage getting disconnected
679 accidentally, etc. your image will most probably be rendered unusable.
680 @item discard=@var{discard}
681 @var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls
682 whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
683 ignored or passed to the filesystem. Some machine types may not support
684 discard requests.
685 @item detect-zeroes=@var{detect-zeroes}
686 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
687 conversion of plain zero writes by the OS to driver specific optimized
688 zero write commands. You may even choose "unmap" if @var{discard} is set
689 to "unmap" to allow a zero write to be converted to an @code{unmap} operation.
690 @end table
692 @item Driver-specific options for @code{file}
694 This is the protocol-level block driver for accessing regular files.
696 @table @code
697 @item filename
698 The path to the image file in the local filesystem
699 @item aio
700 Specifies the AIO backend (threads/native, default: threads)
701 @item locking
702 Specifies whether the image file is protected with Linux OFD / POSIX locks. The
703 default is to use the Linux Open File Descriptor API if available, otherwise no
704 lock is applied. (auto/on/off, default: auto)
705 @end table
706 Example:
707 @example
708 -blockdev driver=file,node-name=disk,filename=disk.img
709 @end example
711 @item Driver-specific options for @code{raw}
713 This is the image format block driver for raw images. It is usually
714 stacked on top of a protocol level block driver such as @code{file}.
716 @table @code
717 @item file
718 Reference to or definition of the data source block driver node
719 (e.g. a @code{file} driver node)
720 @end table
721 Example 1:
722 @example
723 -blockdev driver=file,node-name=disk_file,filename=disk.img
724 -blockdev driver=raw,node-name=disk,file=disk_file
725 @end example
726 Example 2:
727 @example
728 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
729 @end example
731 @item Driver-specific options for @code{qcow2}
733 This is the image format block driver for qcow2 images. It is usually
734 stacked on top of a protocol level block driver such as @code{file}.
736 @table @code
737 @item file
738 Reference to or definition of the data source block driver node
739 (e.g. a @code{file} driver node)
741 @item backing
742 Reference to or definition of the backing file block device (default is taken
743 from the image file). It is allowed to pass an empty string here in order to
744 disable the default backing file.
746 @item lazy-refcounts
747 Whether to enable the lazy refcounts feature (on/off; default is taken from the
748 image file)
750 @item cache-size
751 The maximum total size of the L2 table and refcount block caches in bytes
752 (default: 1048576 bytes or 8 clusters, whichever is larger)
754 @item l2-cache-size
755 The maximum size of the L2 table cache in bytes
756 (default: 4/5 of the total cache size)
758 @item refcount-cache-size
759 The maximum size of the refcount block cache in bytes
760 (default: 1/5 of the total cache size)
762 @item cache-clean-interval
763 Clean unused entries in the L2 and refcount caches. The interval is in seconds.
764 The default value is 0 and it disables this feature.
766 @item pass-discard-request
767 Whether discard requests to the qcow2 device should be forwarded to the data
768 source (on/off; default: on if discard=unmap is specified, off otherwise)
770 @item pass-discard-snapshot
771 Whether discard requests for the data source should be issued when a snapshot
772 operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
773 default: on)
775 @item pass-discard-other
776 Whether discard requests for the data source should be issued on other
777 occasions where a cluster gets freed (on/off; default: off)
779 @item overlap-check
780 Which overlap checks to perform for writes to the image
781 (none/constant/cached/all; default: cached). For details or finer
782 granularity control refer to the QAPI documentation of @code{blockdev-add}.
783 @end table
785 Example 1:
786 @example
787 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
788 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
789 @end example
790 Example 2:
791 @example
792 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
793 @end example
795 @item Driver-specific options for other drivers
796 Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
798 @end table
800 ETEXI
802 DEF("drive", HAS_ARG, QEMU_OPTION_drive,
803 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
804 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
805 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
806 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
807 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
808 " [,readonly=on|off][,copy-on-read=on|off]\n"
809 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
810 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
811 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
812 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
813 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
814 " [[,iops_size=is]]\n"
815 " [[,group=g]]\n"
816 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
817 STEXI
818 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
819 @findex -drive
821 Define a new drive. This includes creating a block driver node (the backend) as
822 well as a guest device, and is mostly a shortcut for defining the corresponding
823 @option{-blockdev} and @option{-device} options.
825 @option{-drive} accepts all options that are accepted by @option{-blockdev}. In
826 addition, it knows the following options:
828 @table @option
829 @item file=@var{file}
830 This option defines which disk image (@pxref{disk_images}) to use with
831 this drive. If the filename contains comma, you must double it
832 (for instance, "file=my,,file" to use file "my,file").
834 Special files such as iSCSI devices can be specified using protocol
835 specific URLs. See the section for "Device URL Syntax" for more information.
836 @item if=@var{interface}
837 This option defines on which type on interface the drive is connected.
838 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
839 @item bus=@var{bus},unit=@var{unit}
840 These options define where is connected the drive by defining the bus number and
841 the unit id.
842 @item index=@var{index}
843 This option defines where is connected the drive by using an index in the list
844 of available connectors of a given interface type.
845 @item media=@var{media}
846 This option defines the type of the media: disk or cdrom.
847 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
848 Force disk physical geometry and the optional BIOS translation (trans=none or
849 lba). These parameters are deprecated, use the corresponding parameters
850 of @code{-device} instead.
851 @item snapshot=@var{snapshot}
852 @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
853 (see @option{-snapshot}).
854 @item cache=@var{cache}
855 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
856 and controls how the host cache is used to access block data. This is a
857 shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
858 options (as in @option{-blockdev}), and additionally @option{cache.writeback},
859 which provides a default for the @option{write-cache} option of block guest
860 devices (as in @option{-device}). The modes correspond to the following
861 settings:
863 @c Our texi2pod.pl script doesn't support @multitable, so fall back to using
864 @c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
865 @c and the HTML output.
866 @example
867 @ │ cache.writeback cache.direct cache.no-flush
868 ─────────────┼─────────────────────────────────────────────────
869 writeback │ on off off
870 none │ on on off
871 writethrough │ off off off
872 directsync │ off on off
873 unsafe │ on off on
874 @end example
876 The default mode is @option{cache=writeback}.
878 @item aio=@var{aio}
879 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
880 @item format=@var{format}
881 Specify which disk @var{format} will be used rather than detecting
882 the format. Can be used to specify format=raw to avoid interpreting
883 an untrusted format header.
884 @item serial=@var{serial}
885 This option specifies the serial number to assign to the device. This
886 parameter is deprecated, use the corresponding parameter of @code{-device}
887 instead.
888 @item addr=@var{addr}
889 Specify the controller's PCI address (if=virtio only). This parameter is
890 deprecated, use the corresponding parameter of @code{-device} instead.
891 @item werror=@var{action},rerror=@var{action}
892 Specify which @var{action} to take on write and read errors. Valid actions are:
893 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
894 "report" (report the error to the guest), "enospc" (pause QEMU only if the
895 host disk is full; report the error to the guest otherwise).
896 The default setting is @option{werror=enospc} and @option{rerror=report}.
897 @item copy-on-read=@var{copy-on-read}
898 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
899 file sectors into the image file.
900 @item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
901 Specify bandwidth throttling limits in bytes per second, either for all request
902 types or for reads or writes only. Small values can lead to timeouts or hangs
903 inside the guest. A safe minimum for disks is 2 MB/s.
904 @item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
905 Specify bursts in bytes per second, either for all request types or for reads
906 or writes only. Bursts allow the guest I/O to spike above the limit
907 temporarily.
908 @item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
909 Specify request rate limits in requests per second, either for all request
910 types or for reads or writes only.
911 @item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
912 Specify bursts in requests per second, either for all request types or for reads
913 or writes only. Bursts allow the guest I/O to spike above the limit
914 temporarily.
915 @item iops_size=@var{is}
916 Let every @var{is} bytes of a request count as a new request for iops
917 throttling purposes. Use this option to prevent guests from circumventing iops
918 limits by sending fewer but larger requests.
919 @item group=@var{g}
920 Join a throttling quota group with given name @var{g}. All drives that are
921 members of the same group are accounted for together. Use this option to
922 prevent guests from circumventing throttling limits by using many small disks
923 instead of a single larger disk.
924 @end table
926 By default, the @option{cache.writeback=on} mode is used. It will report data
927 writes as completed as soon as the data is present in the host page cache.
928 This is safe as long as your guest OS makes sure to correctly flush disk caches
929 where needed. If your guest OS does not handle volatile disk write caches
930 correctly and your host crashes or loses power, then the guest may experience
931 data corruption.
933 For such guests, you should consider using @option{cache.writeback=off}. This
934 means that the host page cache will be used to read and write data, but write
935 notification will be sent to the guest only after QEMU has made sure to flush
936 each write to the disk. Be aware that this has a major impact on performance.
938 When using the @option{-snapshot} option, unsafe caching is always used.
940 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
941 useful when the backing file is over a slow network. By default copy-on-read
942 is off.
944 Instead of @option{-cdrom} you can use:
945 @example
946 qemu-system-i386 -drive file=file,index=2,media=cdrom
947 @end example
949 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
950 use:
951 @example
952 qemu-system-i386 -drive file=file,index=0,media=disk
953 qemu-system-i386 -drive file=file,index=1,media=disk
954 qemu-system-i386 -drive file=file,index=2,media=disk
955 qemu-system-i386 -drive file=file,index=3,media=disk
956 @end example
958 You can open an image using pre-opened file descriptors from an fd set:
959 @example
960 qemu-system-i386
961 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
962 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
963 -drive file=/dev/fdset/2,index=0,media=disk
964 @end example
966 You can connect a CDROM to the slave of ide0:
967 @example
968 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
969 @end example
971 If you don't specify the "file=" argument, you define an empty drive:
972 @example
973 qemu-system-i386 -drive if=ide,index=1,media=cdrom
974 @end example
976 Instead of @option{-fda}, @option{-fdb}, you can use:
977 @example
978 qemu-system-i386 -drive file=file,index=0,if=floppy
979 qemu-system-i386 -drive file=file,index=1,if=floppy
980 @end example
982 By default, @var{interface} is "ide" and @var{index} is automatically
983 incremented:
984 @example
985 qemu-system-i386 -drive file=a -drive file=b"
986 @end example
987 is interpreted like:
988 @example
989 qemu-system-i386 -hda a -hdb b
990 @end example
991 ETEXI
993 DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
994 "-mtdblock file use 'file' as on-board Flash memory image\n",
995 QEMU_ARCH_ALL)
996 STEXI
997 @item -mtdblock @var{file}
998 @findex -mtdblock
999 Use @var{file} as on-board Flash memory image.
1000 ETEXI
1002 DEF("sd", HAS_ARG, QEMU_OPTION_sd,
1003 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
1004 STEXI
1005 @item -sd @var{file}
1006 @findex -sd
1007 Use @var{file} as SecureDigital card image.
1008 ETEXI
1010 DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
1011 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
1012 STEXI
1013 @item -pflash @var{file}
1014 @findex -pflash
1015 Use @var{file} as a parallel flash image.
1016 ETEXI
1018 DEF("snapshot", 0, QEMU_OPTION_snapshot,
1019 "-snapshot write to temporary files instead of disk image files\n",
1020 QEMU_ARCH_ALL)
1021 STEXI
1022 @item -snapshot
1023 @findex -snapshot
1024 Write to temporary files instead of disk image files. In this case,
1025 the raw disk image you use is not written back. You can however force
1026 the write back by pressing @key{C-a s} (@pxref{disk_images}).
1027 ETEXI
1029 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
1030 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1031 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1032 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1033 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1034 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1035 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1036 " [[,throttling.iops-size=is]]\n",
1037 QEMU_ARCH_ALL)
1039 STEXI
1041 @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}]
1042 @findex -fsdev
1043 Define a new file system device. Valid options are:
1044 @table @option
1045 @item @var{fsdriver}
1046 This option specifies the fs driver backend to use.
1047 Currently "local", "handle" and "proxy" file system drivers are supported.
1048 @item id=@var{id}
1049 Specifies identifier for this device
1050 @item path=@var{path}
1051 Specifies the export path for the file system device. Files under
1052 this path will be available to the 9p client on the guest.
1053 @item security_model=@var{security_model}
1054 Specifies the security model to be used for this export path.
1055 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1056 In "passthrough" security model, files are stored using the same
1057 credentials as they are created on the guest. This requires QEMU
1058 to run as root. In "mapped-xattr" security model, some of the file
1059 attributes like uid, gid, mode bits and link target are stored as
1060 file attributes. For "mapped-file" these attributes are stored in the
1061 hidden .virtfs_metadata directory. Directories exported by this security model cannot
1062 interact with other unix tools. "none" security model is same as
1063 passthrough except the sever won't report failures if it fails to
1064 set file attributes like ownership. Security model is mandatory
1065 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
1066 security model as a parameter.
1067 @item writeout=@var{writeout}
1068 This is an optional argument. The only supported value is "immediate".
1069 This means that host page cache will be used to read and write data but
1070 write notification will be sent to the guest only when the data has been
1071 reported as written by the storage subsystem.
1072 @item readonly
1073 Enables exporting 9p share as a readonly mount for guests. By default
1074 read-write access is given.
1075 @item socket=@var{socket}
1076 Enables proxy filesystem driver to use passed socket file for communicating
1077 with virtfs-proxy-helper
1078 @item sock_fd=@var{sock_fd}
1079 Enables proxy filesystem driver to use passed socket descriptor for
1080 communicating with virtfs-proxy-helper. Usually a helper like libvirt
1081 will create socketpair and pass one of the fds as sock_fd
1082 @item fmode=@var{fmode}
1083 Specifies the default mode for newly created files on the host. Works only
1084 with security models "mapped-xattr" and "mapped-file".
1085 @item dmode=@var{dmode}
1086 Specifies the default mode for newly created directories on the host. Works
1087 only with security models "mapped-xattr" and "mapped-file".
1088 @end table
1090 -fsdev option is used along with -device driver "virtio-9p-pci".
1091 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
1092 Options for virtio-9p-pci driver are:
1093 @table @option
1094 @item fsdev=@var{id}
1095 Specifies the id value specified along with -fsdev option
1096 @item mount_tag=@var{mount_tag}
1097 Specifies the tag name to be used by the guest to mount this export point
1098 @end table
1100 ETEXI
1102 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
1103 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1104 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1105 QEMU_ARCH_ALL)
1107 STEXI
1109 @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}]
1110 @findex -virtfs
1112 The general form of a Virtual File system pass-through options are:
1113 @table @option
1114 @item @var{fsdriver}
1115 This option specifies the fs driver backend to use.
1116 Currently "local", "handle" and "proxy" file system drivers are supported.
1117 @item id=@var{id}
1118 Specifies identifier for this device
1119 @item path=@var{path}
1120 Specifies the export path for the file system device. Files under
1121 this path will be available to the 9p client on the guest.
1122 @item security_model=@var{security_model}
1123 Specifies the security model to be used for this export path.
1124 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1125 In "passthrough" security model, files are stored using the same
1126 credentials as they are created on the guest. This requires QEMU
1127 to run as root. In "mapped-xattr" security model, some of the file
1128 attributes like uid, gid, mode bits and link target are stored as
1129 file attributes. For "mapped-file" these attributes are stored in the
1130 hidden .virtfs_metadata directory. Directories exported by this security model cannot
1131 interact with other unix tools. "none" security model is same as
1132 passthrough except the sever won't report failures if it fails to
1133 set file attributes like ownership. Security model is mandatory only
1134 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
1135 model as a parameter.
1136 @item writeout=@var{writeout}
1137 This is an optional argument. The only supported value is "immediate".
1138 This means that host page cache will be used to read and write data but
1139 write notification will be sent to the guest only when the data has been
1140 reported as written by the storage subsystem.
1141 @item readonly
1142 Enables exporting 9p share as a readonly mount for guests. By default
1143 read-write access is given.
1144 @item socket=@var{socket}
1145 Enables proxy filesystem driver to use passed socket file for
1146 communicating with virtfs-proxy-helper. Usually a helper like libvirt
1147 will create socketpair and pass one of the fds as sock_fd
1148 @item sock_fd
1149 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
1150 descriptor for interfacing with virtfs-proxy-helper
1151 @item fmode=@var{fmode}
1152 Specifies the default mode for newly created files on the host. Works only
1153 with security models "mapped-xattr" and "mapped-file".
1154 @item dmode=@var{dmode}
1155 Specifies the default mode for newly created directories on the host. Works
1156 only with security models "mapped-xattr" and "mapped-file".
1157 @end table
1158 ETEXI
1160 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
1161 "-virtfs_synth Create synthetic file system image\n",
1162 QEMU_ARCH_ALL)
1163 STEXI
1164 @item -virtfs_synth
1165 @findex -virtfs_synth
1166 Create synthetic file system image
1167 ETEXI
1169 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1170 "-iscsi [user=user][,password=password]\n"
1171 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1172 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1173 " [,timeout=timeout]\n"
1174 " iSCSI session parameters\n", QEMU_ARCH_ALL)
1176 STEXI
1177 @item -iscsi
1178 @findex -iscsi
1179 Configure iSCSI session parameters.
1180 ETEXI
1182 STEXI
1183 @end table
1184 ETEXI
1185 DEFHEADING()
1187 DEFHEADING(USB options:)
1188 STEXI
1189 @table @option
1190 ETEXI
1192 DEF("usb", 0, QEMU_OPTION_usb,
1193 "-usb enable the USB driver (if it is not used by default yet)\n",
1194 QEMU_ARCH_ALL)
1195 STEXI
1196 @item -usb
1197 @findex -usb
1198 Enable the USB driver (if it is not used by default yet).
1199 ETEXI
1201 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1202 "-usbdevice name add the host or guest USB device 'name'\n",
1203 QEMU_ARCH_ALL)
1204 STEXI
1206 @item -usbdevice @var{devname}
1207 @findex -usbdevice
1208 Add the USB device @var{devname}. Note that this option is deprecated,
1209 please use @code{-device usb-...} instead. @xref{usb_devices}.
1211 @table @option
1213 @item mouse
1214 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1216 @item tablet
1217 Pointer device that uses absolute coordinates (like a touchscreen). This
1218 means QEMU is able to report the mouse position without having to grab the
1219 mouse. Also overrides the PS/2 mouse emulation when activated.
1221 @item braille
1222 Braille device. This will use BrlAPI to display the braille output on a real
1223 or fake device.
1225 @end table
1226 ETEXI
1228 STEXI
1229 @end table
1230 ETEXI
1231 DEFHEADING()
1233 DEFHEADING(Display options:)
1234 STEXI
1235 @table @option
1236 ETEXI
1238 DEF("display", HAS_ARG, QEMU_OPTION_display,
1239 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1240 " [,window_close=on|off][,gl=on|off]\n"
1241 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1242 "-display vnc=<display>[,<optargs>]\n"
1243 "-display curses\n"
1244 "-display none"
1245 " select display type\n"
1246 "The default display is equivalent to\n"
1247 #if defined(CONFIG_GTK)
1248 "\t\"-display gtk\"\n"
1249 #elif defined(CONFIG_SDL)
1250 "\t\"-display sdl\"\n"
1251 #elif defined(CONFIG_COCOA)
1252 "\t\"-display cocoa\"\n"
1253 #elif defined(CONFIG_VNC)
1254 "\t\"-vnc localhost:0,to=99,id=default\"\n"
1255 #else
1256 "\t\"-display none\"\n"
1257 #endif
1258 , QEMU_ARCH_ALL)
1259 STEXI
1260 @item -display @var{type}
1261 @findex -display
1262 Select type of display to use. This option is a replacement for the
1263 old style -sdl/-curses/... options. Valid values for @var{type} are
1264 @table @option
1265 @item sdl
1266 Display video output via SDL (usually in a separate graphics
1267 window; see the SDL documentation for other possibilities).
1268 @item curses
1269 Display video output via curses. For graphics device models which
1270 support a text mode, QEMU can display this output using a
1271 curses/ncurses interface. Nothing is displayed when the graphics
1272 device is in graphical mode or if the graphics device does not support
1273 a text mode. Generally only the VGA device models support text mode.
1274 @item none
1275 Do not display video output. The guest will still see an emulated
1276 graphics card, but its output will not be displayed to the QEMU
1277 user. This option differs from the -nographic option in that it
1278 only affects what is done with video output; -nographic also changes
1279 the destination of the serial and parallel port data.
1280 @item gtk
1281 Display video output in a GTK window. This interface provides drop-down
1282 menus and other UI elements to configure and control the VM during
1283 runtime.
1284 @item vnc
1285 Start a VNC server on display <arg>
1286 @end table
1287 ETEXI
1289 DEF("nographic", 0, QEMU_OPTION_nographic,
1290 "-nographic disable graphical output and redirect serial I/Os to console\n",
1291 QEMU_ARCH_ALL)
1292 STEXI
1293 @item -nographic
1294 @findex -nographic
1295 Normally, if QEMU is compiled with graphical window support, it displays
1296 output such as guest graphics, guest console, and the QEMU monitor in a
1297 window. With this option, you can totally disable graphical output so
1298 that QEMU is a simple command line application. The emulated serial port
1299 is redirected on the console and muxed with the monitor (unless
1300 redirected elsewhere explicitly). Therefore, you can still use QEMU to
1301 debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1302 switching between the console and monitor.
1303 ETEXI
1305 DEF("curses", 0, QEMU_OPTION_curses,
1306 "-curses shorthand for -display curses\n",
1307 QEMU_ARCH_ALL)
1308 STEXI
1309 @item -curses
1310 @findex -curses
1311 Normally, if QEMU is compiled with graphical window support, it displays
1312 output such as guest graphics, guest console, and the QEMU monitor in a
1313 window. With this option, QEMU can display the VGA output when in text
1314 mode using a curses/ncurses interface. Nothing is displayed in graphical
1315 mode.
1316 ETEXI
1318 DEF("no-frame", 0, QEMU_OPTION_no_frame,
1319 "-no-frame open SDL window without a frame and window decorations\n",
1320 QEMU_ARCH_ALL)
1321 STEXI
1322 @item -no-frame
1323 @findex -no-frame
1324 Do not use decorations for SDL windows and start them using the whole
1325 available screen space. This makes the using QEMU in a dedicated desktop
1326 workspace more convenient.
1327 ETEXI
1329 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1330 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1331 QEMU_ARCH_ALL)
1332 STEXI
1333 @item -alt-grab
1334 @findex -alt-grab
1335 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1336 affects the special keys (for fullscreen, monitor-mode switching, etc).
1337 ETEXI
1339 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1340 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1341 QEMU_ARCH_ALL)
1342 STEXI
1343 @item -ctrl-grab
1344 @findex -ctrl-grab
1345 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1346 affects the special keys (for fullscreen, monitor-mode switching, etc).
1347 ETEXI
1349 DEF("no-quit", 0, QEMU_OPTION_no_quit,
1350 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
1351 STEXI
1352 @item -no-quit
1353 @findex -no-quit
1354 Disable SDL window close capability.
1355 ETEXI
1357 DEF("sdl", 0, QEMU_OPTION_sdl,
1358 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL)
1359 STEXI
1360 @item -sdl
1361 @findex -sdl
1362 Enable SDL.
1363 ETEXI
1365 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1366 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1367 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1368 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1369 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1370 " [,tls-ciphers=<list>]\n"
1371 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1372 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1373 " [,sasl][,password=<secret>][,disable-ticketing]\n"
1374 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1375 " [,jpeg-wan-compression=[auto|never|always]]\n"
1376 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
1377 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1378 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1379 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1380 " [,gl=[on|off]][,rendernode=<file>]\n"
1381 " enable spice\n"
1382 " at least one of {port, tls-port} is mandatory\n",
1383 QEMU_ARCH_ALL)
1384 STEXI
1385 @item -spice @var{option}[,@var{option}[,...]]
1386 @findex -spice
1387 Enable the spice remote desktop protocol. Valid options are
1389 @table @option
1391 @item port=<nr>
1392 Set the TCP port spice is listening on for plaintext channels.
1394 @item addr=<addr>
1395 Set the IP address spice is listening on. Default is any address.
1397 @item ipv4
1398 @itemx ipv6
1399 @itemx unix
1400 Force using the specified IP version.
1402 @item password=<secret>
1403 Set the password you need to authenticate.
1405 @item sasl
1406 Require that the client use SASL to authenticate with the spice.
1407 The exact choice of authentication method used is controlled from the
1408 system / user's SASL configuration file for the 'qemu' service. This
1409 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1410 unprivileged user, an environment variable SASL_CONF_PATH can be used
1411 to make it search alternate locations for the service config.
1412 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1413 it is recommended that SASL always be combined with the 'tls' and
1414 'x509' settings to enable use of SSL and server certificates. This
1415 ensures a data encryption preventing compromise of authentication
1416 credentials.
1418 @item disable-ticketing
1419 Allow client connects without authentication.
1421 @item disable-copy-paste
1422 Disable copy paste between the client and the guest.
1424 @item disable-agent-file-xfer
1425 Disable spice-vdagent based file-xfer between the client and the guest.
1427 @item tls-port=<nr>
1428 Set the TCP port spice is listening on for encrypted channels.
1430 @item x509-dir=<dir>
1431 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1433 @item x509-key-file=<file>
1434 @itemx x509-key-password=<file>
1435 @itemx x509-cert-file=<file>
1436 @itemx x509-cacert-file=<file>
1437 @itemx x509-dh-key-file=<file>
1438 The x509 file names can also be configured individually.
1440 @item tls-ciphers=<list>
1441 Specify which ciphers to use.
1443 @item tls-channel=[main|display|cursor|inputs|record|playback]
1444 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1445 Force specific channel to be used with or without TLS encryption. The
1446 options can be specified multiple times to configure multiple
1447 channels. The special name "default" can be used to set the default
1448 mode. For channels which are not explicitly forced into one mode the
1449 spice client is allowed to pick tls/plaintext as he pleases.
1451 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1452 Configure image compression (lossless).
1453 Default is auto_glz.
1455 @item jpeg-wan-compression=[auto|never|always]
1456 @itemx zlib-glz-wan-compression=[auto|never|always]
1457 Configure wan image compression (lossy for slow links).
1458 Default is auto.
1460 @item streaming-video=[off|all|filter]
1461 Configure video stream detection. Default is off.
1463 @item agent-mouse=[on|off]
1464 Enable/disable passing mouse events via vdagent. Default is on.
1466 @item playback-compression=[on|off]
1467 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1469 @item seamless-migration=[on|off]
1470 Enable/disable spice seamless migration. Default is off.
1472 @item gl=[on|off]
1473 Enable/disable OpenGL context. Default is off.
1475 @item rendernode=<file>
1476 DRM render node for OpenGL rendering. If not specified, it will pick
1477 the first available. (Since 2.9)
1479 @end table
1480 ETEXI
1482 DEF("portrait", 0, QEMU_OPTION_portrait,
1483 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1484 QEMU_ARCH_ALL)
1485 STEXI
1486 @item -portrait
1487 @findex -portrait
1488 Rotate graphical output 90 deg left (only PXA LCD).
1489 ETEXI
1491 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1492 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1493 QEMU_ARCH_ALL)
1494 STEXI
1495 @item -rotate @var{deg}
1496 @findex -rotate
1497 Rotate graphical output some deg left (only PXA LCD).
1498 ETEXI
1500 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1501 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1502 " select video card type\n", QEMU_ARCH_ALL)
1503 STEXI
1504 @item -vga @var{type}
1505 @findex -vga
1506 Select type of VGA card to emulate. Valid values for @var{type} are
1507 @table @option
1508 @item cirrus
1509 Cirrus Logic GD5446 Video card. All Windows versions starting from
1510 Windows 95 should recognize and use this graphic card. For optimal
1511 performances, use 16 bit color depth in the guest and the host OS.
1512 (This card was the default before QEMU 2.2)
1513 @item std
1514 Standard VGA card with Bochs VBE extensions. If your guest OS
1515 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1516 to use high resolution modes (>= 1280x1024x16) then you should use
1517 this option. (This card is the default since QEMU 2.2)
1518 @item vmware
1519 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1520 recent XFree86/XOrg server or Windows guest with a driver for this
1521 card.
1522 @item qxl
1523 QXL paravirtual graphic card. It is VGA compatible (including VESA
1524 2.0 VBE support). Works best with qxl guest drivers installed though.
1525 Recommended choice when using the spice protocol.
1526 @item tcx
1527 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1528 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1529 fixed resolution of 1024x768.
1530 @item cg3
1531 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1532 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1533 resolutions aimed at people wishing to run older Solaris versions.
1534 @item virtio
1535 Virtio VGA card.
1536 @item none
1537 Disable VGA card.
1538 @end table
1539 ETEXI
1541 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1542 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1543 STEXI
1544 @item -full-screen
1545 @findex -full-screen
1546 Start in full screen.
1547 ETEXI
1549 DEF("g", 1, QEMU_OPTION_g ,
1550 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1551 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1552 STEXI
1553 @item -g @var{width}x@var{height}[x@var{depth}]
1554 @findex -g
1555 Set the initial graphical resolution and depth (PPC, SPARC only).
1556 ETEXI
1558 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1559 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1560 STEXI
1561 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1562 @findex -vnc
1563 Normally, if QEMU is compiled with graphical window support, it displays
1564 output such as guest graphics, guest console, and the QEMU monitor in a
1565 window. With this option, you can have QEMU listen on VNC display
1566 @var{display} and redirect the VGA display over the VNC session. It is
1567 very useful to enable the usb tablet device when using this option
1568 (option @option{-device usb-tablet}). When using the VNC display, you
1569 must use the @option{-k} parameter to set the keyboard layout if you are
1570 not using en-us. Valid syntax for the @var{display} is
1572 @table @option
1574 @item to=@var{L}
1576 With this option, QEMU will try next available VNC @var{display}s, until the
1577 number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1578 available, e.g. port 5900+@var{display} is already used by another
1579 application. By default, to=0.
1581 @item @var{host}:@var{d}
1583 TCP connections will only be allowed from @var{host} on display @var{d}.
1584 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1585 be omitted in which case the server will accept connections from any host.
1587 @item unix:@var{path}
1589 Connections will be allowed over UNIX domain sockets where @var{path} is the
1590 location of a unix socket to listen for connections on.
1592 @item none
1594 VNC is initialized but not started. The monitor @code{change} command
1595 can be used to later start the VNC server.
1597 @end table
1599 Following the @var{display} value there may be one or more @var{option} flags
1600 separated by commas. Valid options are
1602 @table @option
1604 @item reverse
1606 Connect to a listening VNC client via a ``reverse'' connection. The
1607 client is specified by the @var{display}. For reverse network
1608 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1609 is a TCP port number, not a display number.
1611 @item websocket
1613 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1614 If a bare @var{websocket} option is given, the Websocket port is
1615 5700+@var{display}. An alternative port can be specified with the
1616 syntax @code{websocket}=@var{port}.
1618 If @var{host} is specified connections will only be allowed from this host.
1619 It is possible to control the websocket listen address independently, using
1620 the syntax @code{websocket}=@var{host}:@var{port}.
1622 If no TLS credentials are provided, the websocket connection runs in
1623 unencrypted mode. If TLS credentials are provided, the websocket connection
1624 requires encrypted client connections.
1626 @item password
1628 Require that password based authentication is used for client connections.
1630 The password must be set separately using the @code{set_password} command in
1631 the @ref{pcsys_monitor}. The syntax to change your password is:
1632 @code{set_password <protocol> <password>} where <protocol> could be either
1633 "vnc" or "spice".
1635 If you would like to change <protocol> password expiration, you should use
1636 @code{expire_password <protocol> <expiration-time>} where expiration time could
1637 be one of the following options: now, never, +seconds or UNIX time of
1638 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1639 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1640 date and time).
1642 You can also use keywords "now" or "never" for the expiration time to
1643 allow <protocol> password to expire immediately or never expire.
1645 @item tls-creds=@var{ID}
1647 Provides the ID of a set of TLS credentials to use to secure the
1648 VNC server. They will apply to both the normal VNC server socket
1649 and the websocket socket (if enabled). Setting TLS credentials
1650 will cause the VNC server socket to enable the VeNCrypt auth
1651 mechanism. The credentials should have been previously created
1652 using the @option{-object tls-creds} argument.
1654 The @option{tls-creds} parameter obsoletes the @option{tls},
1655 @option{x509}, and @option{x509verify} options, and as such
1656 it is not permitted to set both new and old type options at
1657 the same time.
1659 @item tls
1661 Require that client use TLS when communicating with the VNC server. This
1662 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1663 attack. It is recommended that this option be combined with either the
1664 @option{x509} or @option{x509verify} options.
1666 This option is now deprecated in favor of using the @option{tls-creds}
1667 argument.
1669 @item x509=@var{/path/to/certificate/dir}
1671 Valid if @option{tls} is specified. Require that x509 credentials are used
1672 for negotiating the TLS session. The server will send its x509 certificate
1673 to the client. It is recommended that a password be set on the VNC server
1674 to provide authentication of the client when this is used. The path following
1675 this option specifies where the x509 certificates are to be loaded from.
1676 See the @ref{vnc_security} section for details on generating certificates.
1678 This option is now deprecated in favour of using the @option{tls-creds}
1679 argument.
1681 @item x509verify=@var{/path/to/certificate/dir}
1683 Valid if @option{tls} is specified. Require that x509 credentials are used
1684 for negotiating the TLS session. The server will send its x509 certificate
1685 to the client, and request that the client send its own x509 certificate.
1686 The server will validate the client's certificate against the CA certificate,
1687 and reject clients when validation fails. If the certificate authority is
1688 trusted, this is a sufficient authentication mechanism. You may still wish
1689 to set a password on the VNC server as a second authentication layer. The
1690 path following this option specifies where the x509 certificates are to
1691 be loaded from. See the @ref{vnc_security} section for details on generating
1692 certificates.
1694 This option is now deprecated in favour of using the @option{tls-creds}
1695 argument.
1697 @item sasl
1699 Require that the client use SASL to authenticate with the VNC server.
1700 The exact choice of authentication method used is controlled from the
1701 system / user's SASL configuration file for the 'qemu' service. This
1702 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1703 unprivileged user, an environment variable SASL_CONF_PATH can be used
1704 to make it search alternate locations for the service config.
1705 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1706 it is recommended that SASL always be combined with the 'tls' and
1707 'x509' settings to enable use of SSL and server certificates. This
1708 ensures a data encryption preventing compromise of authentication
1709 credentials. See the @ref{vnc_security} section for details on using
1710 SASL authentication.
1712 @item acl
1714 Turn on access control lists for checking of the x509 client certificate
1715 and SASL party. For x509 certs, the ACL check is made against the
1716 certificate's distinguished name. This is something that looks like
1717 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1718 made against the username, which depending on the SASL plugin, may
1719 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1720 When the @option{acl} flag is set, the initial access list will be
1721 empty, with a @code{deny} policy. Thus no one will be allowed to
1722 use the VNC server until the ACLs have been loaded. This can be
1723 achieved using the @code{acl} monitor command.
1725 @item lossy
1727 Enable lossy compression methods (gradient, JPEG, ...). If this
1728 option is set, VNC client may receive lossy framebuffer updates
1729 depending on its encoding settings. Enabling this option can save
1730 a lot of bandwidth at the expense of quality.
1732 @item non-adaptive
1734 Disable adaptive encodings. Adaptive encodings are enabled by default.
1735 An adaptive encoding will try to detect frequently updated screen regions,
1736 and send updates in these regions using a lossy encoding (like JPEG).
1737 This can be really helpful to save bandwidth when playing videos. Disabling
1738 adaptive encodings restores the original static behavior of encodings
1739 like Tight.
1741 @item share=[allow-exclusive|force-shared|ignore]
1743 Set display sharing policy. 'allow-exclusive' allows clients to ask
1744 for exclusive access. As suggested by the rfb spec this is
1745 implemented by dropping other connections. Connecting multiple
1746 clients in parallel requires all clients asking for a shared session
1747 (vncviewer: -shared switch). This is the default. 'force-shared'
1748 disables exclusive client access. Useful for shared desktop sessions,
1749 where you don't want someone forgetting specify -shared disconnect
1750 everybody else. 'ignore' completely ignores the shared flag and
1751 allows everybody connect unconditionally. Doesn't conform to the rfb
1752 spec but is traditional QEMU behavior.
1754 @item key-delay-ms
1756 Set keyboard delay, for key down and key up events, in milliseconds.
1757 Default is 10. Keyboards are low-bandwidth devices, so this slowdown
1758 can help the device and guest to keep up and not lose events in case
1759 events are arriving in bulk. Possible causes for the latter are flaky
1760 network connections, or scripts for automated testing.
1762 @end table
1763 ETEXI
1765 STEXI
1766 @end table
1767 ETEXI
1768 ARCHHEADING(, QEMU_ARCH_I386)
1770 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1771 STEXI
1772 @table @option
1773 ETEXI
1775 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1776 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1777 QEMU_ARCH_I386)
1778 STEXI
1779 @item -win2k-hack
1780 @findex -win2k-hack
1781 Use it when installing Windows 2000 to avoid a disk full bug. After
1782 Windows 2000 is installed, you no longer need this option (this option
1783 slows down the IDE transfers).
1784 ETEXI
1786 HXCOMM Deprecated by -rtc
1787 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1789 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1790 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1791 QEMU_ARCH_I386)
1792 STEXI
1793 @item -no-fd-bootchk
1794 @findex -no-fd-bootchk
1795 Disable boot signature checking for floppy disks in BIOS. May
1796 be needed to boot from old floppy disks.
1797 ETEXI
1799 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1800 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1801 STEXI
1802 @item -no-acpi
1803 @findex -no-acpi
1804 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1805 it if your guest OS complains about ACPI problems (PC target machine
1806 only).
1807 ETEXI
1809 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1810 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1811 STEXI
1812 @item -no-hpet
1813 @findex -no-hpet
1814 Disable HPET support.
1815 ETEXI
1817 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1818 "-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"
1819 " ACPI table description\n", QEMU_ARCH_I386)
1820 STEXI
1821 @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}]...]
1822 @findex -acpitable
1823 Add ACPI table with specified header fields and context from specified files.
1824 For file=, take whole ACPI table from the specified files, including all
1825 ACPI headers (possible overridden by other options).
1826 For data=, only data
1827 portion of the table is used, all header information is specified in the
1828 command line.
1829 If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1830 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1831 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1832 spec.
1833 ETEXI
1835 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1836 "-smbios file=binary\n"
1837 " load SMBIOS entry from binary file\n"
1838 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1839 " [,uefi=on|off]\n"
1840 " specify SMBIOS type 0 fields\n"
1841 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1842 " [,uuid=uuid][,sku=str][,family=str]\n"
1843 " specify SMBIOS type 1 fields\n"
1844 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1845 " [,asset=str][,location=str]\n"
1846 " specify SMBIOS type 2 fields\n"
1847 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1848 " [,sku=str]\n"
1849 " specify SMBIOS type 3 fields\n"
1850 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1851 " [,asset=str][,part=str]\n"
1852 " specify SMBIOS type 4 fields\n"
1853 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1854 " [,asset=str][,part=str][,speed=%d]\n"
1855 " specify SMBIOS type 17 fields\n",
1856 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1857 STEXI
1858 @item -smbios file=@var{binary}
1859 @findex -smbios
1860 Load SMBIOS entry from binary file.
1862 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1863 Specify SMBIOS type 0 fields
1865 @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}]
1866 Specify SMBIOS type 1 fields
1868 @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}]
1869 Specify SMBIOS type 2 fields
1871 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1872 Specify SMBIOS type 3 fields
1874 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1875 Specify SMBIOS type 4 fields
1877 @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}]
1878 Specify SMBIOS type 17 fields
1879 ETEXI
1881 STEXI
1882 @end table
1883 ETEXI
1884 DEFHEADING()
1886 DEFHEADING(Network options:)
1887 STEXI
1888 @table @option
1889 ETEXI
1891 HXCOMM Legacy slirp options (now moved to -net user):
1892 #ifdef CONFIG_SLIRP
1893 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1894 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1895 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1896 #ifndef _WIN32
1897 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1898 #endif
1899 #endif
1901 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1902 #ifdef CONFIG_SLIRP
1903 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1904 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1905 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1906 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
1907 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1908 #ifndef _WIN32
1909 "[,smb=dir[,smbserver=addr]]\n"
1910 #endif
1911 " configure a user mode network backend with ID 'str',\n"
1912 " its DHCP server and optional services\n"
1913 #endif
1914 #ifdef _WIN32
1915 "-netdev tap,id=str,ifname=name\n"
1916 " configure a host TAP network backend with ID 'str'\n"
1917 #else
1918 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1919 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1920 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1921 " [,poll-us=n]\n"
1922 " configure a host TAP network backend with ID 'str'\n"
1923 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1924 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1925 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1926 " to deconfigure it\n"
1927 " use '[down]script=no' to disable script execution\n"
1928 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1929 " configure it\n"
1930 " use 'fd=h' to connect to an already opened TAP interface\n"
1931 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1932 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1933 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1934 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1935 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1936 " use vhost=on to enable experimental in kernel accelerator\n"
1937 " (only has effect for virtio guests which use MSIX)\n"
1938 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1939 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
1940 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1941 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1942 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1943 " spent on busy polling for vhost net\n"
1944 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1945 " configure a host TAP network backend with ID 'str' that is\n"
1946 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1947 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1948 #endif
1949 #ifdef __linux__
1950 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1951 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1952 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1953 " [,rxcookie=rxcookie][,offset=offset]\n"
1954 " configure a network backend with ID 'str' connected to\n"
1955 " an Ethernet over L2TPv3 pseudowire.\n"
1956 " Linux kernel 3.3+ as well as most routers can talk\n"
1957 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1958 " VM to a router and even VM to Host. It is a nearly-universal\n"
1959 " standard (RFC3391). Note - this implementation uses static\n"
1960 " pre-configured tunnels (same as the Linux kernel).\n"
1961 " use 'src=' to specify source address\n"
1962 " use 'dst=' to specify destination address\n"
1963 " use 'udp=on' to specify udp encapsulation\n"
1964 " use 'srcport=' to specify source udp port\n"
1965 " use 'dstport=' to specify destination udp port\n"
1966 " use 'ipv6=on' to force v6\n"
1967 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1968 " well as a weak security measure\n"
1969 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
1970 " use 'txcookie=0x012345678' to specify a txcookie\n"
1971 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1972 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1973 " use 'pincounter=on' to work around broken counter handling in peer\n"
1974 " use 'offset=X' to add an extra offset between header and data\n"
1975 #endif
1976 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1977 " configure a network backend to connect to another network\n"
1978 " using a socket connection\n"
1979 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1980 " configure a network backend to connect to a multicast maddr and port\n"
1981 " use 'localaddr=addr' to specify the host address to send packets from\n"
1982 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1983 " configure a network backend to connect to another network\n"
1984 " using an UDP tunnel\n"
1985 #ifdef CONFIG_VDE
1986 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1987 " configure a network backend to connect to port 'n' of a vde switch\n"
1988 " running on host and listening for incoming connections on 'socketpath'.\n"
1989 " Use group 'groupname' and mode 'octalmode' to change default\n"
1990 " ownership and permissions for communication port.\n"
1991 #endif
1992 #ifdef CONFIG_NETMAP
1993 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1994 " attach to the existing netmap-enabled network interface 'name', or to a\n"
1995 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1996 " netmap device, defaults to '/dev/netmap')\n"
1997 #endif
1998 #ifdef CONFIG_POSIX
1999 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2000 " configure a vhost-user network, backed by a chardev 'dev'\n"
2001 #endif
2002 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
2003 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
2004 DEF("nic", HAS_ARG, QEMU_OPTION_nic,
2005 "--nic [tap|bridge|"
2006 #ifdef CONFIG_SLIRP
2007 "user|"
2008 #endif
2009 #ifdef __linux__
2010 "l2tpv3|"
2011 #endif
2012 #ifdef CONFIG_VDE
2013 "vde|"
2014 #endif
2015 #ifdef CONFIG_NETMAP
2016 "netmap|"
2017 #endif
2018 #ifdef CONFIG_POSIX
2019 "vhost-user|"
2020 #endif
2021 "socket][,option][,...][mac=macaddr]\n"
2022 " initialize an on-board / default host NIC (using MAC address\n"
2023 " macaddr) and connect it to the given host network backend\n"
2024 "--nic none use it alone to have zero network devices (the default is to\n"
2025 " provided a 'user' network connection)\n",
2026 QEMU_ARCH_ALL)
2027 DEF("net", HAS_ARG, QEMU_OPTION_net,
2028 "-net nic[,vlan=n][,netdev=nd][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
2029 " configure or create an on-board (or machine default) NIC and\n"
2030 " connect it either to VLAN 'n' or the netdev 'nd' (for pluggable\n"
2031 " NICs please use '-device devtype,netdev=nd' instead)\n"
2032 "-net ["
2033 #ifdef CONFIG_SLIRP
2034 "user|"
2035 #endif
2036 "tap|"
2037 "bridge|"
2038 #ifdef CONFIG_VDE
2039 "vde|"
2040 #endif
2041 #ifdef CONFIG_NETMAP
2042 "netmap|"
2043 #endif
2044 "socket][,vlan=n][,option][,option][,...]\n"
2045 " old way to initialize a host network interface\n"
2046 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2047 STEXI
2048 @item -net nic[,vlan=@var{n}][,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2049 @findex -net
2050 Configure or create an on-board (or machine default) Network Interface Card
2051 (NIC) and connect it either to VLAN @var{n} (@var{n} = 0 is the default), or
2052 to the netdev @var{nd}. The NIC is an e1000 by default on the PC
2053 target. Optionally, the MAC address can be changed to @var{mac}, the
2054 device address set to @var{addr} (PCI cards only),
2055 and a @var{name} can be assigned for use in monitor commands.
2056 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2057 that the card should have; this option currently only affects virtio cards; set
2058 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2059 NIC is created. QEMU can emulate several different models of network card.
2060 Valid values for @var{type} are
2061 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
2062 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
2063 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
2064 Not all devices are supported on all targets. Use @code{-net nic,model=help}
2065 for a list of available devices for your target.
2067 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2068 @findex -netdev
2069 @item -net user[,@var{option}][,@var{option}][,...]
2070 Use the user mode network stack which requires no administrator
2071 privilege to run. Valid options are:
2073 @table @option
2074 @item vlan=@var{n}
2075 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
2077 @item id=@var{id}
2078 @itemx name=@var{name}
2079 Assign symbolic name for use in monitor commands.
2081 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
2082 be enabled. If neither is specified both protocols are enabled.
2084 @item net=@var{addr}[/@var{mask}]
2085 Set IP network address the guest will see. Optionally specify the netmask,
2086 either in the form a.b.c.d or as number of valid top-most bits. Default is
2087 10.0.2.0/24.
2089 @item host=@var{addr}
2090 Specify the guest-visible address of the host. Default is the 2nd IP in the
2091 guest network, i.e. x.x.x.2.
2093 @item ipv6-net=@var{addr}[/@var{int}]
2094 Set IPv6 network address the guest will see (default is fec0::/64). The
2095 network prefix is given in the usual hexadecimal IPv6 address
2096 notation. The prefix size is optional, and is given as the number of
2097 valid top-most bits (default is 64).
2099 @item ipv6-host=@var{addr}
2100 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2101 the guest network, i.e. xxxx::2.
2103 @item restrict=on|off
2104 If this option is enabled, the guest will be isolated, i.e. it will not be
2105 able to contact the host and no guest IP packets will be routed over the host
2106 to the outside. This option does not affect any explicitly set forwarding rules.
2108 @item hostname=@var{name}
2109 Specifies the client hostname reported by the built-in DHCP server.
2111 @item dhcpstart=@var{addr}
2112 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2113 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2115 @item dns=@var{addr}
2116 Specify the guest-visible address of the virtual nameserver. The address must
2117 be different from the host address. Default is the 3rd IP in the guest network,
2118 i.e. x.x.x.3.
2120 @item ipv6-dns=@var{addr}
2121 Specify the guest-visible address of the IPv6 virtual nameserver. The address
2122 must be different from the host address. Default is the 3rd IP in the guest
2123 network, i.e. xxxx::3.
2125 @item dnssearch=@var{domain}
2126 Provides an entry for the domain-search list sent by the built-in
2127 DHCP server. More than one domain suffix can be transmitted by specifying
2128 this option multiple times. If supported, this will cause the guest to
2129 automatically try to append the given domain suffix(es) in case a domain name
2130 can not be resolved.
2132 Example:
2133 @example
2134 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
2135 @end example
2137 @item tftp=@var{dir}
2138 When using the user mode network stack, activate a built-in TFTP
2139 server. The files in @var{dir} will be exposed as the root of a TFTP server.
2140 The TFTP client on the guest must be configured in binary mode (use the command
2141 @code{bin} of the Unix TFTP client).
2143 @item bootfile=@var{file}
2144 When using the user mode network stack, broadcast @var{file} as the BOOTP
2145 filename. In conjunction with @option{tftp}, this can be used to network boot
2146 a guest from a local directory.
2148 Example (using pxelinux):
2149 @example
2150 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2151 @end example
2153 @item smb=@var{dir}[,smbserver=@var{addr}]
2154 When using the user mode network stack, activate a built-in SMB
2155 server so that Windows OSes can access to the host files in @file{@var{dir}}
2156 transparently. The IP address of the SMB server can be set to @var{addr}. By
2157 default the 4th IP in the guest network is used, i.e. x.x.x.4.
2159 In the guest Windows OS, the line:
2160 @example
2161 10.0.2.4 smbserver
2162 @end example
2163 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2164 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2166 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2168 Note that a SAMBA server must be installed on the host OS.
2169 QEMU was tested successfully with smbd versions from Red Hat 9,
2170 Fedora Core 3 and OpenSUSE 11.x.
2172 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2173 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2174 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2175 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2176 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2177 be bound to a specific host interface. If no connection type is set, TCP is
2178 used. This option can be given multiple times.
2180 For example, to redirect host X11 connection from screen 1 to guest
2181 screen 0, use the following:
2183 @example
2184 # on the host
2185 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
2186 # this host xterm should open in the guest X11 server
2187 xterm -display :1
2188 @end example
2190 To redirect telnet connections from host port 5555 to telnet port on
2191 the guest, use the following:
2193 @example
2194 # on the host
2195 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
2196 telnet localhost 5555
2197 @end example
2199 Then when you use on the host @code{telnet localhost 5555}, you
2200 connect to the guest telnet server.
2202 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2203 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2204 Forward guest TCP connections to the IP address @var{server} on port @var{port}
2205 to the character device @var{dev} or to a program executed by @var{cmd:command}
2206 which gets spawned for each connection. This option can be given multiple times.
2208 You can either use a chardev directly and have that one used throughout QEMU's
2209 lifetime, like in the following example:
2211 @example
2212 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2213 # the guest accesses it
2214 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
2215 @end example
2217 Or you can execute a command on every TCP connection established by the guest,
2218 so that QEMU behaves similar to an inetd process for that virtual server:
2220 @example
2221 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2222 # and connect the TCP stream to its stdin/stdout
2223 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2224 @end example
2226 @end table
2228 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2229 processed and applied to -net user. Mixing them with the new configuration
2230 syntax gives undefined results. Their use for new applications is discouraged
2231 as they will be removed from future versions.
2233 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2234 @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}]
2235 Connect the host TAP network interface @var{name} to VLAN @var{n}.
2237 Use the network script @var{file} to configure it and the network script
2238 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2239 automatically provides one. The default network configure script is
2240 @file{/etc/qemu-ifup} and the default network deconfigure script is
2241 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2242 to disable script execution.
2244 If running QEMU as an unprivileged user, use the network helper
2245 @var{helper} to configure the TAP interface and attach it to the bridge.
2246 The default network helper executable is @file{/path/to/qemu-bridge-helper}
2247 and the default bridge device is @file{br0}.
2249 @option{fd}=@var{h} can be used to specify the handle of an already
2250 opened host TAP interface.
2252 Examples:
2254 @example
2255 #launch a QEMU instance with the default network script
2256 qemu-system-i386 linux.img -net nic -net tap
2257 @end example
2259 @example
2260 #launch a QEMU instance with two NICs, each one connected
2261 #to a TAP device
2262 qemu-system-i386 linux.img \
2263 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2264 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2265 @end example
2267 @example
2268 #launch a QEMU instance with the default network helper to
2269 #connect a TAP device to bridge br0
2270 qemu-system-i386 linux.img \
2271 -net nic -net tap,"helper=/path/to/qemu-bridge-helper"
2272 @end example
2274 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2275 @itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
2276 Connect a host TAP network interface to a host bridge device.
2278 Use the network helper @var{helper} to configure the TAP interface and
2279 attach it to the bridge. The default network helper executable is
2280 @file{/path/to/qemu-bridge-helper} and the default bridge
2281 device is @file{br0}.
2283 Examples:
2285 @example
2286 #launch a QEMU instance with the default network helper to
2287 #connect a TAP device to bridge br0
2288 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
2289 @end example
2291 @example
2292 #launch a QEMU instance with the default network helper to
2293 #connect a TAP device to bridge qemubr0
2294 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
2295 @end example
2297 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2298 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2300 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
2301 machine using a TCP socket connection. If @option{listen} is
2302 specified, QEMU waits for incoming connections on @var{port}
2303 (@var{host} is optional). @option{connect} is used to connect to
2304 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2305 specifies an already opened TCP socket.
2307 Example:
2308 @example
2309 # launch a first QEMU instance
2310 qemu-system-i386 linux.img \
2311 -net nic,macaddr=52:54:00:12:34:56 \
2312 -net socket,listen=:1234
2313 # connect the VLAN 0 of this instance to the VLAN 0
2314 # of the first instance
2315 qemu-system-i386 linux.img \
2316 -net nic,macaddr=52:54:00:12:34:57 \
2317 -net socket,connect=127.0.0.1:1234
2318 @end example
2320 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2321 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2323 Create a VLAN @var{n} shared with another QEMU virtual
2324 machines using a UDP multicast socket, effectively making a bus for
2325 every QEMU with same multicast address @var{maddr} and @var{port}.
2326 NOTES:
2327 @enumerate
2328 @item
2329 Several QEMU can be running on different hosts and share same bus (assuming
2330 correct multicast setup for these hosts).
2331 @item
2332 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2333 @url{http://user-mode-linux.sf.net}.
2334 @item
2335 Use @option{fd=h} to specify an already opened UDP multicast socket.
2336 @end enumerate
2338 Example:
2339 @example
2340 # launch one QEMU instance
2341 qemu-system-i386 linux.img \
2342 -net nic,macaddr=52:54:00:12:34:56 \
2343 -net socket,mcast=230.0.0.1:1234
2344 # launch another QEMU instance on same "bus"
2345 qemu-system-i386 linux.img \
2346 -net nic,macaddr=52:54:00:12:34:57 \
2347 -net socket,mcast=230.0.0.1:1234
2348 # launch yet another QEMU instance on same "bus"
2349 qemu-system-i386 linux.img \
2350 -net nic,macaddr=52:54:00:12:34:58 \
2351 -net socket,mcast=230.0.0.1:1234
2352 @end example
2354 Example (User Mode Linux compat.):
2355 @example
2356 # launch QEMU instance (note mcast address selected
2357 # is UML's default)
2358 qemu-system-i386 linux.img \
2359 -net nic,macaddr=52:54:00:12:34:56 \
2360 -net socket,mcast=239.192.168.1:1102
2361 # launch UML
2362 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2363 @end example
2365 Example (send packets from host's 1.2.3.4):
2366 @example
2367 qemu-system-i386 linux.img \
2368 -net nic,macaddr=52:54:00:12:34:56 \
2369 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2370 @end example
2372 @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}]
2373 @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}]
2374 Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
2375 protocol to transport Ethernet (and other Layer 2) data frames between
2376 two systems. It is present in routers, firewalls and the Linux kernel
2377 (from version 3.3 onwards).
2379 This transport allows a VM to communicate to another VM, router or firewall directly.
2381 @table @option
2382 @item src=@var{srcaddr}
2383 source address (mandatory)
2384 @item dst=@var{dstaddr}
2385 destination address (mandatory)
2386 @item udp
2387 select udp encapsulation (default is ip).
2388 @item srcport=@var{srcport}
2389 source udp port.
2390 @item dstport=@var{dstport}
2391 destination udp port.
2392 @item ipv6
2393 force v6, otherwise defaults to v4.
2394 @item rxcookie=@var{rxcookie}
2395 @itemx txcookie=@var{txcookie}
2396 Cookies are a weak form of security in the l2tpv3 specification.
2397 Their function is mostly to prevent misconfiguration. By default they are 32
2398 bit.
2399 @item cookie64
2400 Set cookie size to 64 bit instead of the default 32
2401 @item counter=off
2402 Force a 'cut-down' L2TPv3 with no counter as in
2403 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2404 @item pincounter=on
2405 Work around broken counter handling in peer. This may also help on
2406 networks which have packet reorder.
2407 @item offset=@var{offset}
2408 Add an extra offset between header and data
2409 @end table
2411 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2412 on the remote Linux host 1.2.3.4:
2413 @example
2414 # Setup tunnel on linux host using raw ip as encapsulation
2415 # on 1.2.3.4
2416 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2417 encap udp udp_sport 16384 udp_dport 16384
2418 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2419 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2420 ifconfig vmtunnel0 mtu 1500
2421 ifconfig vmtunnel0 up
2422 brctl addif br-lan vmtunnel0
2425 # on 4.3.2.1
2426 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2428 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
2431 @end example
2433 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2434 @itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2435 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2436 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2437 and MODE @var{octalmode} to change default ownership and permissions for
2438 communication port. This option is only available if QEMU has been compiled
2439 with vde support enabled.
2441 Example:
2442 @example
2443 # launch vde switch
2444 vde_switch -F -sock /tmp/myswitch
2445 # launch QEMU instance
2446 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2447 @end example
2449 @item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2451 Create a hub port on QEMU "vlan" @var{hubid}.
2453 The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single
2454 netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
2455 required hub automatically. Alternatively, you can also connect the hubport
2456 to another netdev with ID @var{nd} by using the @option{netdev=@var{nd}}
2457 option.
2459 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2461 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2462 be a unix domain socket backed one. The vhost-user uses a specifically defined
2463 protocol to pass vhost ioctl replacement messages to an application on the other
2464 end of the socket. On non-MSIX guests, the feature can be forced with
2465 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2466 be created for multiqueue vhost-user.
2468 Example:
2469 @example
2470 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2471 -numa node,memdev=mem \
2472 -chardev socket,id=chr0,path=/path/to/socket \
2473 -netdev type=vhost-user,id=net0,chardev=chr0 \
2474 -device virtio-net-pci,netdev=net0
2475 @end example
2477 @item --nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr]
2479 This option is a shortcut for setting both, the on-board (default) guest NIC
2480 hardware and the host network backend in one go. The host backend options are
2481 the same as with the corresponding @option{--netdev} option. The guest NIC
2482 hardware MAC address can be set with @option{mac=@var{macaddr}}.
2484 @item --nic none
2485 Indicate that no network devices should be configured. It is used to override
2486 the default configuration (default NIC with @option{--net user} backend) which
2487 is activated if no other networking options are provided.
2488 ETEXI
2490 STEXI
2491 @end table
2492 ETEXI
2493 DEFHEADING()
2495 DEFHEADING(Character device options:)
2497 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2498 "-chardev help\n"
2499 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2500 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2501 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2502 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2503 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2504 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2505 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2506 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2507 " [,logfile=PATH][,logappend=on|off]\n"
2508 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2509 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2510 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2511 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2512 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2513 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2514 #ifdef _WIN32
2515 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2516 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2517 #else
2518 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2519 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2520 #endif
2521 #ifdef CONFIG_BRLAPI
2522 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2523 #endif
2524 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2525 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2526 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2527 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2528 #endif
2529 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2530 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2531 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2532 #endif
2533 #if defined(CONFIG_SPICE)
2534 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2535 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2536 #endif
2537 , QEMU_ARCH_ALL
2540 STEXI
2542 The general form of a character device option is:
2543 @table @option
2544 @item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2545 @findex -chardev
2546 Backend is one of:
2547 @option{null},
2548 @option{socket},
2549 @option{udp},
2550 @option{msmouse},
2551 @option{vc},
2552 @option{ringbuf},
2553 @option{file},
2554 @option{pipe},
2555 @option{console},
2556 @option{serial},
2557 @option{pty},
2558 @option{stdio},
2559 @option{braille},
2560 @option{tty},
2561 @option{parallel},
2562 @option{parport},
2563 @option{spicevmc},
2564 @option{spiceport}.
2565 The specific backend will determine the applicable options.
2567 Use @code{-chardev help} to print all available chardev backend types.
2569 All devices must have an id, which can be any string up to 127 characters long.
2570 It is used to uniquely identify this device in other command line directives.
2572 A character device may be used in multiplexing mode by multiple front-ends.
2573 Specify @option{mux=on} to enable this mode.
2574 A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2575 backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2576 If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2577 create a multiplexer with your specified ID, and you can then configure multiple
2578 front ends to use that chardev ID for their input/output. Up to four different
2579 front ends can be connected to a single multiplexed chardev. (Without
2580 multiplexing enabled, a chardev can only be used by a single front end.)
2581 For instance you could use this to allow a single stdio chardev to be used by
2582 two serial ports and the QEMU monitor:
2584 @example
2585 -chardev stdio,mux=on,id=char0 \
2586 -mon chardev=char0,mode=readline \
2587 -serial chardev:char0 \
2588 -serial chardev:char0
2589 @end example
2591 You can have more than one multiplexer in a system configuration; for instance
2592 you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2593 multiplexed between the QEMU monitor and a parallel port:
2595 @example
2596 -chardev stdio,mux=on,id=char0 \
2597 -mon chardev=char0,mode=readline \
2598 -parallel chardev:char0 \
2599 -chardev tcp,...,mux=on,id=char1 \
2600 -serial chardev:char1 \
2601 -serial chardev:char1
2602 @end example
2604 When you're using a multiplexed character device, some escape sequences are
2605 interpreted in the input. @xref{mux_keys, Keys in the character backend
2606 multiplexer}.
2608 Note that some other command line options may implicitly create multiplexed
2609 character backends; for instance @option{-serial mon:stdio} creates a
2610 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2611 and @option{-nographic} also multiplexes the console and the monitor to
2612 stdio.
2614 There is currently no support for multiplexing in the other direction
2615 (where a single QEMU front end takes input and output from multiple chardevs).
2617 Every backend supports the @option{logfile} option, which supplies the path
2618 to a file to record all data transmitted via the backend. The @option{logappend}
2619 option controls whether the log file will be truncated or appended to when
2620 opened.
2622 @end table
2624 The available backends are:
2626 @table @option
2627 @item -chardev null,id=@var{id}
2628 A void device. This device will not emit any data, and will drop any data it
2629 receives. The null backend does not take any options.
2631 @item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2633 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2634 unix socket will be created if @option{path} is specified. Behaviour is
2635 undefined if TCP options are specified for a unix socket.
2637 @option{server} specifies that the socket shall be a listening socket.
2639 @option{nowait} specifies that QEMU should not block waiting for a client to
2640 connect to a listening socket.
2642 @option{telnet} specifies that traffic on the socket should interpret telnet
2643 escape sequences.
2645 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2646 the remote end goes away. qemu will delay this many seconds and then attempt
2647 to reconnect. Zero disables reconnecting, and is the default.
2649 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2650 and specifies the id of the TLS credentials to use for the handshake. The
2651 credentials must be previously created with the @option{-object tls-creds}
2652 argument.
2654 TCP and unix socket options are given below:
2656 @table @option
2658 @item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2660 @option{host} for a listening socket specifies the local address to be bound.
2661 For a connecting socket species the remote host to connect to. @option{host} is
2662 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2664 @option{port} for a listening socket specifies the local port to be bound. For a
2665 connecting socket specifies the port on the remote host to connect to.
2666 @option{port} can be given as either a port number or a service name.
2667 @option{port} is required.
2669 @option{to} is only relevant to listening sockets. If it is specified, and
2670 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2671 to and including @option{to} until it succeeds. @option{to} must be specified
2672 as a port number.
2674 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2675 If neither is specified the socket may use either protocol.
2677 @option{nodelay} disables the Nagle algorithm.
2679 @item unix options: path=@var{path}
2681 @option{path} specifies the local path of the unix socket. @option{path} is
2682 required.
2684 @end table
2686 @item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2688 Sends all traffic from the guest to a remote host over UDP.
2690 @option{host} specifies the remote host to connect to. If not specified it
2691 defaults to @code{localhost}.
2693 @option{port} specifies the port on the remote host to connect to. @option{port}
2694 is required.
2696 @option{localaddr} specifies the local address to bind to. If not specified it
2697 defaults to @code{0.0.0.0}.
2699 @option{localport} specifies the local port to bind to. If not specified any
2700 available local port will be used.
2702 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2703 If neither is specified the device may use either protocol.
2705 @item -chardev msmouse,id=@var{id}
2707 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2708 take any options.
2710 @item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2712 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2713 size.
2715 @option{width} and @option{height} specify the width and height respectively of
2716 the console, in pixels.
2718 @option{cols} and @option{rows} specify that the console be sized to fit a text
2719 console with the given dimensions.
2721 @item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2723 Create a ring buffer with fixed size @option{size}.
2724 @var{size} must be a power of two and defaults to @code{64K}.
2726 @item -chardev file,id=@var{id},path=@var{path}
2728 Log all traffic received from the guest to a file.
2730 @option{path} specifies the path of the file to be opened. This file will be
2731 created if it does not already exist, and overwritten if it does. @option{path}
2732 is required.
2734 @item -chardev pipe,id=@var{id},path=@var{path}
2736 Create a two-way connection to the guest. The behaviour differs slightly between
2737 Windows hosts and other hosts:
2739 On Windows, a single duplex pipe will be created at
2740 @file{\\.pipe\@option{path}}.
2742 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2743 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2744 received by the guest. Data written by the guest can be read from
2745 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2746 be present.
2748 @option{path} forms part of the pipe path as described above. @option{path} is
2749 required.
2751 @item -chardev console,id=@var{id}
2753 Send traffic from the guest to QEMU's standard output. @option{console} does not
2754 take any options.
2756 @option{console} is only available on Windows hosts.
2758 @item -chardev serial,id=@var{id},path=@option{path}
2760 Send traffic from the guest to a serial device on the host.
2762 On Unix hosts serial will actually accept any tty device,
2763 not only serial lines.
2765 @option{path} specifies the name of the serial device to open.
2767 @item -chardev pty,id=@var{id}
2769 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2770 not take any options.
2772 @option{pty} is not available on Windows hosts.
2774 @item -chardev stdio,id=@var{id}[,signal=on|off]
2775 Connect to standard input and standard output of the QEMU process.
2777 @option{signal} controls if signals are enabled on the terminal, that includes
2778 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2779 default, use @option{signal=off} to disable it.
2781 @item -chardev braille,id=@var{id}
2783 Connect to a local BrlAPI server. @option{braille} does not take any options.
2785 @item -chardev tty,id=@var{id},path=@var{path}
2787 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2788 DragonFlyBSD hosts. It is an alias for @option{serial}.
2790 @option{path} specifies the path to the tty. @option{path} is required.
2792 @item -chardev parallel,id=@var{id},path=@var{path}
2793 @itemx -chardev parport,id=@var{id},path=@var{path}
2795 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2797 Connect to a local parallel port.
2799 @option{path} specifies the path to the parallel port device. @option{path} is
2800 required.
2802 @item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2804 @option{spicevmc} is only available when spice support is built in.
2806 @option{debug} debug level for spicevmc
2808 @option{name} name of spice channel to connect to
2810 Connect to a spice virtual machine channel, such as vdiport.
2812 @item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2814 @option{spiceport} is only available when spice support is built in.
2816 @option{debug} debug level for spicevmc
2818 @option{name} name of spice port to connect to
2820 Connect to a spice port, allowing a Spice client to handle the traffic
2821 identified by a name (preferably a fqdn).
2822 ETEXI
2824 STEXI
2825 @end table
2826 ETEXI
2827 DEFHEADING()
2829 DEFHEADING(Bluetooth(R) options:)
2830 STEXI
2831 @table @option
2832 ETEXI
2834 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2835 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2836 "-bt hci,host[:id]\n" \
2837 " use host's HCI with the given name\n" \
2838 "-bt hci[,vlan=n]\n" \
2839 " emulate a standard HCI in virtual scatternet 'n'\n" \
2840 "-bt vhci[,vlan=n]\n" \
2841 " add host computer to virtual scatternet 'n' using VHCI\n" \
2842 "-bt device:dev[,vlan=n]\n" \
2843 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2844 QEMU_ARCH_ALL)
2845 STEXI
2846 @item -bt hci[...]
2847 @findex -bt
2848 Defines the function of the corresponding Bluetooth HCI. -bt options
2849 are matched with the HCIs present in the chosen machine type. For
2850 example when emulating a machine with only one HCI built into it, only
2851 the first @code{-bt hci[...]} option is valid and defines the HCI's
2852 logic. The Transport Layer is decided by the machine type. Currently
2853 the machines @code{n800} and @code{n810} have one HCI and all other
2854 machines have none.
2856 @anchor{bt-hcis}
2857 The following three types are recognized:
2859 @table @option
2860 @item -bt hci,null
2861 (default) The corresponding Bluetooth HCI assumes no internal logic
2862 and will not respond to any HCI commands or emit events.
2864 @item -bt hci,host[:@var{id}]
2865 (@code{bluez} only) The corresponding HCI passes commands / events
2866 to / from the physical HCI identified by the name @var{id} (default:
2867 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2868 capable systems like Linux.
2870 @item -bt hci[,vlan=@var{n}]
2871 Add a virtual, standard HCI that will participate in the Bluetooth
2872 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2873 VLANs, devices inside a bluetooth network @var{n} can only communicate
2874 with other devices in the same network (scatternet).
2875 @end table
2877 @item -bt vhci[,vlan=@var{n}]
2878 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2879 to the host bluetooth stack instead of to the emulated target. This
2880 allows the host and target machines to participate in a common scatternet
2881 and communicate. Requires the Linux @code{vhci} driver installed. Can
2882 be used as following:
2884 @example
2885 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2886 @end example
2888 @item -bt device:@var{dev}[,vlan=@var{n}]
2889 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2890 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2891 currently:
2893 @table @option
2894 @item keyboard
2895 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2896 @end table
2897 ETEXI
2899 STEXI
2900 @end table
2901 ETEXI
2902 DEFHEADING()
2904 #ifdef CONFIG_TPM
2905 DEFHEADING(TPM device options:)
2907 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2908 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2909 " use path to provide path to a character device; default is /dev/tpm0\n"
2910 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2911 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2912 "-tpmdev emulator,id=id,chardev=dev\n"
2913 " configure the TPM device using chardev backend\n",
2914 QEMU_ARCH_ALL)
2915 STEXI
2917 The general form of a TPM device option is:
2918 @table @option
2920 @item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2921 @findex -tpmdev
2923 The specific backend type will determine the applicable options.
2924 The @code{-tpmdev} option creates the TPM backend and requires a
2925 @code{-device} option that specifies the TPM frontend interface model.
2927 Use @code{-tpmdev help} to print all available TPM backend types.
2929 @end table
2931 The available backends are:
2933 @table @option
2935 @item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2937 (Linux-host only) Enable access to the host's TPM using the passthrough
2938 driver.
2940 @option{path} specifies the path to the host's TPM device, i.e., on
2941 a Linux host this would be @code{/dev/tpm0}.
2942 @option{path} is optional and by default @code{/dev/tpm0} is used.
2944 @option{cancel-path} specifies the path to the host TPM device's sysfs
2945 entry allowing for cancellation of an ongoing TPM command.
2946 @option{cancel-path} is optional and by default QEMU will search for the
2947 sysfs entry to use.
2949 Some notes about using the host's TPM with the passthrough driver:
2951 The TPM device accessed by the passthrough driver must not be
2952 used by any other application on the host.
2954 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2955 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2956 TPM again and may therefore not show a TPM-specific menu that would
2957 otherwise allow the user to configure the TPM, e.g., allow the user to
2958 enable/disable or activate/deactivate the TPM.
2959 Further, if TPM ownership is released from within a VM then the host's TPM
2960 will get disabled and deactivated. To enable and activate the
2961 TPM again afterwards, the host has to be rebooted and the user is
2962 required to enter the firmware's menu to enable and activate the TPM.
2963 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2965 To create a passthrough TPM use the following two options:
2966 @example
2967 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2968 @end example
2969 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2970 @code{tpmdev=tpm0} in the device option.
2972 @item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2974 (Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2975 chardev backend.
2977 @option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2979 To create a TPM emulator backend device with chardev socket backend:
2980 @example
2982 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2984 @end example
2986 ETEXI
2988 STEXI
2989 @end table
2990 ETEXI
2991 DEFHEADING()
2993 #endif
2995 DEFHEADING(Linux/Multiboot boot specific:)
2996 STEXI
2998 When using these options, you can use a given Linux or Multiboot
2999 kernel without installing it in the disk image. It can be useful
3000 for easier testing of various kernels.
3002 @table @option
3003 ETEXI
3005 DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
3006 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
3007 STEXI
3008 @item -kernel @var{bzImage}
3009 @findex -kernel
3010 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
3011 or in multiboot format.
3012 ETEXI
3014 DEF("append", HAS_ARG, QEMU_OPTION_append, \
3015 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
3016 STEXI
3017 @item -append @var{cmdline}
3018 @findex -append
3019 Use @var{cmdline} as kernel command line
3020 ETEXI
3022 DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
3023 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
3024 STEXI
3025 @item -initrd @var{file}
3026 @findex -initrd
3027 Use @var{file} as initial ram disk.
3029 @item -initrd "@var{file1} arg=foo,@var{file2}"
3031 This syntax is only available with multiboot.
3033 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3034 first module.
3035 ETEXI
3037 DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
3038 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
3039 STEXI
3040 @item -dtb @var{file}
3041 @findex -dtb
3042 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3043 on boot.
3044 ETEXI
3046 STEXI
3047 @end table
3048 ETEXI
3049 DEFHEADING()
3051 DEFHEADING(Debug/Expert options:)
3052 STEXI
3053 @table @option
3054 ETEXI
3056 DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3057 "-fw_cfg [name=]<name>,file=<file>\n"
3058 " add named fw_cfg entry with contents from file\n"
3059 "-fw_cfg [name=]<name>,string=<str>\n"
3060 " add named fw_cfg entry with contents from string\n",
3061 QEMU_ARCH_ALL)
3062 STEXI
3064 @item -fw_cfg [name=]@var{name},file=@var{file}
3065 @findex -fw_cfg
3066 Add named fw_cfg entry with contents from file @var{file}.
3068 @item -fw_cfg [name=]@var{name},string=@var{str}
3069 Add named fw_cfg entry with contents from string @var{str}.
3071 The terminating NUL character of the contents of @var{str} will not be
3072 included as part of the fw_cfg item data. To insert contents with
3073 embedded NUL characters, you have to use the @var{file} parameter.
3075 The fw_cfg entries are passed by QEMU through to the guest.
3077 Example:
3078 @example
3079 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3080 @end example
3081 creates an fw_cfg entry named opt/com.mycompany/blob with contents
3082 from ./my_blob.bin.
3084 ETEXI
3086 DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3087 "-serial dev redirect the serial port to char device 'dev'\n",
3088 QEMU_ARCH_ALL)
3089 STEXI
3090 @item -serial @var{dev}
3091 @findex -serial
3092 Redirect the virtual serial port to host character device
3093 @var{dev}. The default device is @code{vc} in graphical mode and
3094 @code{stdio} in non graphical mode.
3096 This option can be used several times to simulate up to 4 serial
3097 ports.
3099 Use @code{-serial none} to disable all serial ports.
3101 Available character devices are:
3102 @table @option
3103 @item vc[:@var{W}x@var{H}]
3104 Virtual console. Optionally, a width and height can be given in pixel with
3105 @example
3106 vc:800x600
3107 @end example
3108 It is also possible to specify width or height in characters:
3109 @example
3110 vc:80Cx24C
3111 @end example
3112 @item pty
3113 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3114 @item none
3115 No device is allocated.
3116 @item null
3117 void device
3118 @item chardev:@var{id}
3119 Use a named character device defined with the @code{-chardev} option.
3120 @item /dev/XXX
3121 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3122 parameters are set according to the emulated ones.
3123 @item /dev/parport@var{N}
3124 [Linux only, parallel port only] Use host parallel port
3125 @var{N}. Currently SPP and EPP parallel port features can be used.
3126 @item file:@var{filename}
3127 Write output to @var{filename}. No character can be read.
3128 @item stdio
3129 [Unix only] standard input/output
3130 @item pipe:@var{filename}
3131 name pipe @var{filename}
3132 @item COM@var{n}
3133 [Windows only] Use host serial port @var{n}
3134 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3135 This implements UDP Net Console.
3136 When @var{remote_host} or @var{src_ip} are not specified
3137 they default to @code{0.0.0.0}.
3138 When not using a specified @var{src_port} a random port is automatically chosen.
3140 If you just want a simple readonly console you can use @code{netcat} or
3141 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3142 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3143 will appear in the netconsole session.
3145 If you plan to send characters back via netconsole or you want to stop
3146 and start QEMU a lot of times, you should have QEMU use the same
3147 source port each time by using something like @code{-serial
3148 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3149 version of netcat which can listen to a TCP port and send and receive
3150 characters via udp. If you have a patched version of netcat which
3151 activates telnet remote echo and single char transfer, then you can
3152 use the following options to set up a netcat redirector to allow
3153 telnet on port 5555 to access the QEMU port.
3154 @table @code
3155 @item QEMU Options:
3156 -serial udp::4555@@:4556
3157 @item netcat options:
3158 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3159 @item telnet options:
3160 localhost 5555
3161 @end table
3163 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3164 The TCP Net Console has two modes of operation. It can send the serial
3165 I/O to a location or wait for a connection from a location. By default
3166 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3167 the @var{server} option QEMU will wait for a client socket application
3168 to connect to the port before continuing, unless the @code{nowait}
3169 option was specified. The @code{nodelay} option disables the Nagle buffering
3170 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3171 set, if the connection goes down it will attempt to reconnect at the
3172 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3173 one TCP connection at a time is accepted. You can use @code{telnet} to
3174 connect to the corresponding character device.
3175 @table @code
3176 @item Example to send tcp console to 192.168.0.2 port 4444
3177 -serial tcp:192.168.0.2:4444
3178 @item Example to listen and wait on port 4444 for connection
3179 -serial tcp::4444,server
3180 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3181 -serial tcp:192.168.0.100:4444,server,nowait
3182 @end table
3184 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3185 The telnet protocol is used instead of raw tcp sockets. The options
3186 work the same as if you had specified @code{-serial tcp}. The
3187 difference is that the port acts like a telnet server or client using
3188 telnet option negotiation. This will also allow you to send the
3189 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3190 sequence. Typically in unix telnet you do it with Control-] and then
3191 type "send break" followed by pressing the enter key.
3193 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3194 A unix domain socket is used instead of a tcp socket. The option works the
3195 same as if you had specified @code{-serial tcp} except the unix domain socket
3196 @var{path} is used for connections.
3198 @item mon:@var{dev_string}
3199 This is a special option to allow the monitor to be multiplexed onto
3200 another serial port. The monitor is accessed with key sequence of
3201 @key{Control-a} and then pressing @key{c}.
3202 @var{dev_string} should be any one of the serial devices specified
3203 above. An example to multiplex the monitor onto a telnet server
3204 listening on port 4444 would be:
3205 @table @code
3206 @item -serial mon:telnet::4444,server,nowait
3207 @end table
3208 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3209 QEMU any more but will be passed to the guest instead.
3211 @item braille
3212 Braille device. This will use BrlAPI to display the braille output on a real
3213 or fake device.
3215 @item msmouse
3216 Three button serial mouse. Configure the guest to use Microsoft protocol.
3217 @end table
3218 ETEXI
3220 DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3221 "-parallel dev redirect the parallel port to char device 'dev'\n",
3222 QEMU_ARCH_ALL)
3223 STEXI
3224 @item -parallel @var{dev}
3225 @findex -parallel
3226 Redirect the virtual parallel port to host device @var{dev} (same
3227 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3228 be used to use hardware devices connected on the corresponding host
3229 parallel port.
3231 This option can be used several times to simulate up to 3 parallel
3232 ports.
3234 Use @code{-parallel none} to disable all parallel ports.
3235 ETEXI
3237 DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3238 "-monitor dev redirect the monitor to char device 'dev'\n",
3239 QEMU_ARCH_ALL)
3240 STEXI
3241 @item -monitor @var{dev}
3242 @findex -monitor
3243 Redirect the monitor to host device @var{dev} (same devices as the
3244 serial port).
3245 The default device is @code{vc} in graphical mode and @code{stdio} in
3246 non graphical mode.
3247 Use @code{-monitor none} to disable the default monitor.
3248 ETEXI
3249 DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3250 "-qmp dev like -monitor but opens in 'control' mode\n",
3251 QEMU_ARCH_ALL)
3252 STEXI
3253 @item -qmp @var{dev}
3254 @findex -qmp
3255 Like -monitor but opens in 'control' mode.
3256 ETEXI
3257 DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3258 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3259 QEMU_ARCH_ALL)
3260 STEXI
3261 @item -qmp-pretty @var{dev}
3262 @findex -qmp-pretty
3263 Like -qmp but uses pretty JSON formatting.
3264 ETEXI
3266 DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3267 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3268 STEXI
3269 @item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3270 @findex -mon
3271 Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3272 easing human reading and debugging.
3273 ETEXI
3275 DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3276 "-debugcon dev redirect the debug console to char device 'dev'\n",
3277 QEMU_ARCH_ALL)
3278 STEXI
3279 @item -debugcon @var{dev}
3280 @findex -debugcon
3281 Redirect the debug console to host device @var{dev} (same devices as the
3282 serial port). The debug console is an I/O port which is typically port
3283 0xe9; writing to that I/O port sends output to this device.
3284 The default device is @code{vc} in graphical mode and @code{stdio} in
3285 non graphical mode.
3286 ETEXI
3288 DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3289 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
3290 STEXI
3291 @item -pidfile @var{file}
3292 @findex -pidfile
3293 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3294 from a script.
3295 ETEXI
3297 DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3298 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
3299 STEXI
3300 @item -singlestep
3301 @findex -singlestep
3302 Run the emulation in single step mode.
3303 ETEXI
3305 DEF("S", 0, QEMU_OPTION_S, \
3306 "-S freeze CPU at startup (use 'c' to start execution)\n",
3307 QEMU_ARCH_ALL)
3308 STEXI
3309 @item -S
3310 @findex -S
3311 Do not start CPU at startup (you must type 'c' in the monitor).
3312 ETEXI
3314 DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3315 "-realtime [mlock=on|off]\n"
3316 " run qemu with realtime features\n"
3317 " mlock=on|off controls mlock support (default: on)\n",
3318 QEMU_ARCH_ALL)
3319 STEXI
3320 @item -realtime mlock=on|off
3321 @findex -realtime
3322 Run qemu with realtime features.
3323 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3324 (enabled by default).
3325 ETEXI
3327 DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3328 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3329 STEXI
3330 @item -gdb @var{dev}
3331 @findex -gdb
3332 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3333 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3334 stdio are reasonable use case. The latter is allowing to start QEMU from
3335 within gdb and establish the connection via a pipe:
3336 @example
3337 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3338 @end example
3339 ETEXI
3341 DEF("s", 0, QEMU_OPTION_s, \
3342 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3343 QEMU_ARCH_ALL)
3344 STEXI
3345 @item -s
3346 @findex -s
3347 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3348 (@pxref{gdb_usage}).
3349 ETEXI
3351 DEF("d", HAS_ARG, QEMU_OPTION_d, \
3352 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
3353 QEMU_ARCH_ALL)
3354 STEXI
3355 @item -d @var{item1}[,...]
3356 @findex -d
3357 Enable logging of specified items. Use '-d help' for a list of log items.
3358 ETEXI
3360 DEF("D", HAS_ARG, QEMU_OPTION_D, \
3361 "-D logfile output log to logfile (default stderr)\n",
3362 QEMU_ARCH_ALL)
3363 STEXI
3364 @item -D @var{logfile}
3365 @findex -D
3366 Output log in @var{logfile} instead of to stderr
3367 ETEXI
3369 DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3370 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3371 QEMU_ARCH_ALL)
3372 STEXI
3373 @item -dfilter @var{range1}[,...]
3374 @findex -dfilter
3375 Filter debug output to that relevant to a range of target addresses. The filter
3376 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3377 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3378 addresses and sizes required. For example:
3379 @example
3380 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3381 @end example
3382 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3383 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3384 block starting at 0xffffffc00005f000.
3385 ETEXI
3387 DEF("L", HAS_ARG, QEMU_OPTION_L, \
3388 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
3389 QEMU_ARCH_ALL)
3390 STEXI
3391 @item -L @var{path}
3392 @findex -L
3393 Set the directory for the BIOS, VGA BIOS and keymaps.
3395 To list all the data directories, use @code{-L help}.
3396 ETEXI
3398 DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3399 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
3400 STEXI
3401 @item -bios @var{file}
3402 @findex -bios
3403 Set the filename for the BIOS.
3404 ETEXI
3406 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3407 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3408 STEXI
3409 @item -enable-kvm
3410 @findex -enable-kvm
3411 Enable KVM full virtualization support. This option is only available
3412 if KVM support is enabled when compiling.
3413 ETEXI
3415 DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3416 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386)
3417 STEXI
3418 @item -enable-hax
3419 @findex -enable-hax
3420 Enable HAX (Hardware-based Acceleration eXecution) support. This option
3421 is only available if HAX support is enabled when compiling. HAX is only
3422 applicable to MAC and Windows platform, and thus does not conflict with
3423 KVM.
3424 ETEXI
3426 DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3427 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
3428 DEF("xen-create", 0, QEMU_OPTION_xen_create,
3429 "-xen-create create domain using xen hypercalls, bypassing xend\n"
3430 " warning: should not be used when xend is in use\n",
3431 QEMU_ARCH_ALL)
3432 DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3433 "-xen-attach attach to existing xen domain\n"
3434 " xend will use this when starting QEMU\n",
3435 QEMU_ARCH_ALL)
3436 DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3437 "-xen-domid-restrict restrict set of available xen operations\n"
3438 " to specified domain id. (Does not affect\n"
3439 " xenpv machine type).\n",
3440 QEMU_ARCH_ALL)
3441 STEXI
3442 @item -xen-domid @var{id}
3443 @findex -xen-domid
3444 Specify xen guest domain @var{id} (XEN only).
3445 @item -xen-create
3446 @findex -xen-create
3447 Create domain using xen hypercalls, bypassing xend.
3448 Warning: should not be used when xend is in use (XEN only).
3449 @item -xen-attach
3450 @findex -xen-attach
3451 Attach to existing xen domain.
3452 xend will use this when starting QEMU (XEN only).
3453 @findex -xen-domid-restrict
3454 Restrict set of available xen operations to specified domain id (XEN only).
3455 ETEXI
3457 DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3458 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
3459 STEXI
3460 @item -no-reboot
3461 @findex -no-reboot
3462 Exit instead of rebooting.
3463 ETEXI
3465 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3466 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
3467 STEXI
3468 @item -no-shutdown
3469 @findex -no-shutdown
3470 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3471 This allows for instance switching to monitor to commit changes to the
3472 disk image.
3473 ETEXI
3475 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3476 "-loadvm [tag|id]\n" \
3477 " start right away with a saved state (loadvm in monitor)\n",
3478 QEMU_ARCH_ALL)
3479 STEXI
3480 @item -loadvm @var{file}
3481 @findex -loadvm
3482 Start right away with a saved state (@code{loadvm} in monitor)
3483 ETEXI
3485 #ifndef _WIN32
3486 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3487 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3488 #endif
3489 STEXI
3490 @item -daemonize
3491 @findex -daemonize
3492 Daemonize the QEMU process after initialization. QEMU will not detach from
3493 standard IO until it is ready to receive connections on any of its devices.
3494 This option is a useful way for external programs to launch QEMU without having
3495 to cope with initialization race conditions.
3496 ETEXI
3498 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3499 "-option-rom rom load a file, rom, into the option ROM space\n",
3500 QEMU_ARCH_ALL)
3501 STEXI
3502 @item -option-rom @var{file}
3503 @findex -option-rom
3504 Load the contents of @var{file} as an option ROM.
3505 This option is useful to load things like EtherBoot.
3506 ETEXI
3508 HXCOMM Silently ignored for compatibility
3509 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3511 HXCOMM Options deprecated by -rtc
3512 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3513 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3515 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3516 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3517 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3518 QEMU_ARCH_ALL)
3520 STEXI
3522 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3523 @findex -rtc
3524 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3525 UTC or local time, respectively. @code{localtime} is required for correct date in
3526 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3527 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3529 By default the RTC is driven by the host system time. This allows using of the
3530 RTC as accurate reference clock inside the guest, specifically if the host
3531 time is smoothly following an accurate external reference clock, e.g. via NTP.
3532 If you want to isolate the guest time from the host, you can set @option{clock}
3533 to @code{rt} instead. To even prevent it from progressing during suspension,
3534 you can set it to @code{vm}.
3536 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3537 specifically with Windows' ACPI HAL. This option will try to figure out how
3538 many timer interrupts were not processed by the Windows guest and will
3539 re-inject them.
3540 ETEXI
3542 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3543 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3544 " enable virtual instruction counter with 2^N clock ticks per\n" \
3545 " instruction, enable aligning the host and virtual clocks\n" \
3546 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3547 STEXI
3548 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3549 @findex -icount
3550 Enable virtual instruction counter. The virtual cpu will execute one
3551 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3552 then the virtual cpu speed will be automatically adjusted to keep virtual
3553 time within a few seconds of real time.
3555 When the virtual cpu is sleeping, the virtual time will advance at default
3556 speed unless @option{sleep=on|off} is specified.
3557 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3558 instantly whenever the virtual cpu goes to sleep mode and will not advance
3559 if no timer is enabled. This behavior give deterministic execution times from
3560 the guest point of view.
3562 Note that while this option can give deterministic behavior, it does not
3563 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3564 order cores with complex cache hierarchies. The number of instructions
3565 executed often has little or no correlation with actual performance.
3567 @option{align=on} will activate the delay algorithm which will try
3568 to synchronise the host clock and the virtual clock. The goal is to
3569 have a guest running at the real frequency imposed by the shift option.
3570 Whenever the guest clock is behind the host clock and if
3571 @option{align=on} is specified then we print a message to the user
3572 to inform about the delay.
3573 Currently this option does not work when @option{shift} is @code{auto}.
3574 Note: The sync algorithm will work for those shift values for which
3575 the guest clock runs ahead of the host clock. Typically this happens
3576 when the shift value is high (how high depends on the host machine).
3578 When @option{rr} option is specified deterministic record/replay is enabled.
3579 Replay log is written into @var{filename} file in record mode and
3580 read from this file in replay mode.
3582 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3583 at the start of execution recording. In replay mode this option is used
3584 to load the initial VM state.
3585 ETEXI
3587 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3588 "-watchdog model\n" \
3589 " enable virtual hardware watchdog [default=none]\n",
3590 QEMU_ARCH_ALL)
3591 STEXI
3592 @item -watchdog @var{model}
3593 @findex -watchdog
3594 Create a virtual hardware watchdog device. Once enabled (by a guest
3595 action), the watchdog must be periodically polled by an agent inside
3596 the guest or else the guest will be restarted. Choose a model for
3597 which your guest has drivers.
3599 The @var{model} is the model of hardware watchdog to emulate. Use
3600 @code{-watchdog help} to list available hardware models. Only one
3601 watchdog can be enabled for a guest.
3603 The following models may be available:
3604 @table @option
3605 @item ib700
3606 iBASE 700 is a very simple ISA watchdog with a single timer.
3607 @item i6300esb
3608 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3609 dual-timer watchdog.
3610 @item diag288
3611 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3612 (currently KVM only).
3613 @end table
3614 ETEXI
3616 DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3617 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3618 " action when watchdog fires [default=reset]\n",
3619 QEMU_ARCH_ALL)
3620 STEXI
3621 @item -watchdog-action @var{action}
3622 @findex -watchdog-action
3624 The @var{action} controls what QEMU will do when the watchdog timer
3625 expires.
3626 The default is
3627 @code{reset} (forcefully reset the guest).
3628 Other possible actions are:
3629 @code{shutdown} (attempt to gracefully shutdown the guest),
3630 @code{poweroff} (forcefully poweroff the guest),
3631 @code{inject-nmi} (inject a NMI into the guest),
3632 @code{pause} (pause the guest),
3633 @code{debug} (print a debug message and continue), or
3634 @code{none} (do nothing).
3636 Note that the @code{shutdown} action requires that the guest responds
3637 to ACPI signals, which it may not be able to do in the sort of
3638 situations where the watchdog would have expired, and thus
3639 @code{-watchdog-action shutdown} is not recommended for production use.
3641 Examples:
3643 @table @code
3644 @item -watchdog i6300esb -watchdog-action pause
3645 @itemx -watchdog ib700
3646 @end table
3647 ETEXI
3649 DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3650 "-echr chr set terminal escape character instead of ctrl-a\n",
3651 QEMU_ARCH_ALL)
3652 STEXI
3654 @item -echr @var{numeric_ascii_value}
3655 @findex -echr
3656 Change the escape character used for switching to the monitor when using
3657 monitor and serial sharing. The default is @code{0x01} when using the
3658 @code{-nographic} option. @code{0x01} is equal to pressing
3659 @code{Control-a}. You can select a different character from the ascii
3660 control keys where 1 through 26 map to Control-a through Control-z. For
3661 instance you could use the either of the following to change the escape
3662 character to Control-t.
3663 @table @code
3664 @item -echr 0x14
3665 @itemx -echr 20
3666 @end table
3667 ETEXI
3669 DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3670 "-virtioconsole c\n" \
3671 " set virtio console\n", QEMU_ARCH_ALL)
3672 STEXI
3673 @item -virtioconsole @var{c}
3674 @findex -virtioconsole
3675 Set virtio console.
3677 This option is maintained for backward compatibility.
3679 Please use @code{-device virtconsole} for the new way of invocation.
3680 ETEXI
3682 DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3683 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
3684 STEXI
3685 @item -show-cursor
3686 @findex -show-cursor
3687 Show cursor.
3688 ETEXI
3690 DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3691 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
3692 STEXI
3693 @item -tb-size @var{n}
3694 @findex -tb-size
3695 Set TB size.
3696 ETEXI
3698 DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3699 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3700 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3701 "-incoming unix:socketpath\n" \
3702 " prepare for incoming migration, listen on\n" \
3703 " specified protocol and socket address\n" \
3704 "-incoming fd:fd\n" \
3705 "-incoming exec:cmdline\n" \
3706 " accept incoming migration on given file descriptor\n" \
3707 " or from given external command\n" \
3708 "-incoming defer\n" \
3709 " wait for the URI to be specified via migrate_incoming\n",
3710 QEMU_ARCH_ALL)
3711 STEXI
3712 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3713 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3714 @findex -incoming
3715 Prepare for incoming migration, listen on a given tcp port.
3717 @item -incoming unix:@var{socketpath}
3718 Prepare for incoming migration, listen on a given unix socket.
3720 @item -incoming fd:@var{fd}
3721 Accept incoming migration from a given filedescriptor.
3723 @item -incoming exec:@var{cmdline}
3724 Accept incoming migration as an output from specified external command.
3726 @item -incoming defer
3727 Wait for the URI to be specified via migrate_incoming. The monitor can
3728 be used to change settings (such as migration parameters) prior to issuing
3729 the migrate_incoming to allow the migration to begin.
3730 ETEXI
3732 DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3733 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
3734 STEXI
3735 @item -only-migratable
3736 @findex -only-migratable
3737 Only allow migratable devices. Devices will not be allowed to enter an
3738 unmigratable state.
3739 ETEXI
3741 DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3742 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
3743 STEXI
3744 @item -nodefaults
3745 @findex -nodefaults
3746 Don't create default devices. Normally, QEMU sets the default devices like serial
3747 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3748 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3749 default devices.
3750 ETEXI
3752 #ifndef _WIN32
3753 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3754 "-chroot dir chroot to dir just before starting the VM\n",
3755 QEMU_ARCH_ALL)
3756 #endif
3757 STEXI
3758 @item -chroot @var{dir}
3759 @findex -chroot
3760 Immediately before starting guest execution, chroot to the specified
3761 directory. Especially useful in combination with -runas.
3762 ETEXI
3764 #ifndef _WIN32
3765 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3766 "-runas user change to user id user just before starting the VM\n",
3767 QEMU_ARCH_ALL)
3768 #endif
3769 STEXI
3770 @item -runas @var{user}
3771 @findex -runas
3772 Immediately before starting guest execution, drop root privileges, switching
3773 to the specified user.
3774 ETEXI
3776 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3777 "-prom-env variable=value\n"
3778 " set OpenBIOS nvram variables\n",
3779 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3780 STEXI
3781 @item -prom-env @var{variable}=@var{value}
3782 @findex -prom-env
3783 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3784 ETEXI
3785 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3786 "-semihosting semihosting mode\n",
3787 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3788 QEMU_ARCH_MIPS)
3789 STEXI
3790 @item -semihosting
3791 @findex -semihosting
3792 Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3793 ETEXI
3794 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3795 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3796 " semihosting configuration\n",
3797 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3798 QEMU_ARCH_MIPS)
3799 STEXI
3800 @item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3801 @findex -semihosting-config
3802 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3803 @table @option
3804 @item target=@code{native|gdb|auto}
3805 Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3806 or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3807 during debug sessions and @code{native} otherwise.
3808 @item arg=@var{str1},arg=@var{str2},...
3809 Allows the user to pass input arguments, and can be used multiple times to build
3810 up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3811 command line is still supported for backward compatibility. If both the
3812 @code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3813 specified, the former is passed to semihosting as it always takes precedence.
3814 @end table
3815 ETEXI
3816 DEF("old-param", 0, QEMU_OPTION_old_param,
3817 "-old-param old param mode\n", QEMU_ARCH_ARM)
3818 STEXI
3819 @item -old-param
3820 @findex -old-param (ARM)
3821 Old param mode (ARM only).
3822 ETEXI
3824 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3825 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3826 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3827 " Enable seccomp mode 2 system call filter (default 'off').\n" \
3828 " use 'obsolete' to allow obsolete system calls that are provided\n" \
3829 " by the kernel, but typically no longer used by modern\n" \
3830 " C library implementations.\n" \
3831 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3832 " its privileges by blacklisting all set*uid|gid system calls.\n" \
3833 " The value 'children' will deny set*uid|gid system calls for\n" \
3834 " main QEMU process but will allow forks and execves to run unprivileged\n" \
3835 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3836 " blacklisting *fork and execve\n" \
3837 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
3838 QEMU_ARCH_ALL)
3839 STEXI
3840 @item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3841 @findex -sandbox
3842 Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3843 disable it. The default is 'off'.
3844 @table @option
3845 @item obsolete=@var{string}
3846 Enable Obsolete system calls
3847 @item elevateprivileges=@var{string}
3848 Disable set*uid|gid system calls
3849 @item spawn=@var{string}
3850 Disable *fork and execve
3851 @item resourcecontrol=@var{string}
3852 Disable process affinity and schedular priority
3853 @end table
3854 ETEXI
3856 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3857 "-readconfig <file>\n", QEMU_ARCH_ALL)
3858 STEXI
3859 @item -readconfig @var{file}
3860 @findex -readconfig
3861 Read device configuration from @var{file}. This approach is useful when you want to spawn
3862 QEMU process with many command line options but you don't want to exceed the command line
3863 character limit.
3864 ETEXI
3865 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3866 "-writeconfig <file>\n"
3867 " read/write config file\n", QEMU_ARCH_ALL)
3868 STEXI
3869 @item -writeconfig @var{file}
3870 @findex -writeconfig
3871 Write device configuration to @var{file}. The @var{file} can be either filename to save
3872 command line and device configuration into file or dash @code{-}) character to print the
3873 output to stdout. This can be later used as input file for @code{-readconfig} option.
3874 ETEXI
3875 HXCOMM Deprecated, same as -no-user-config
3876 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
3877 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3878 "-no-user-config\n"
3879 " do not load default user-provided config files at startup\n",
3880 QEMU_ARCH_ALL)
3881 STEXI
3882 @item -no-user-config
3883 @findex -no-user-config
3884 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3885 config files on @var{sysconfdir}.
3886 ETEXI
3887 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3888 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3889 " specify tracing options\n",
3890 QEMU_ARCH_ALL)
3891 STEXI
3892 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3893 HXCOMM HX does not support conditional compilation of text.
3894 @item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3895 @findex -trace
3896 @include qemu-option-trace.texi
3897 ETEXI
3899 HXCOMM Internal use
3900 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3901 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3903 #ifdef __linux__
3904 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3905 "-enable-fips enable FIPS 140-2 compliance\n",
3906 QEMU_ARCH_ALL)
3907 #endif
3908 STEXI
3909 @item -enable-fips
3910 @findex -enable-fips
3911 Enable FIPS 140-2 compliance mode.
3912 ETEXI
3914 HXCOMM Deprecated by -machine accel=tcg property
3915 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3917 HXCOMM Deprecated by kvm-pit driver properties
3918 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3919 "", QEMU_ARCH_I386)
3921 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3922 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3924 HXCOMM Deprecated (ignored)
3925 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3927 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3928 "-msg timestamp[=on|off]\n"
3929 " change the format of messages\n"
3930 " on|off controls leading timestamps (default:on)\n",
3931 QEMU_ARCH_ALL)
3932 STEXI
3933 @item -msg timestamp[=on|off]
3934 @findex -msg
3935 prepend a timestamp to each log message.(default:on)
3936 ETEXI
3938 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3939 "-dump-vmstate <file>\n"
3940 " Output vmstate information in JSON format to file.\n"
3941 " Use the scripts/vmstate-static-checker.py file to\n"
3942 " check for possible regressions in migration code\n"
3943 " by comparing two such vmstate dumps.\n",
3944 QEMU_ARCH_ALL)
3945 STEXI
3946 @item -dump-vmstate @var{file}
3947 @findex -dump-vmstate
3948 Dump json-encoded vmstate information for current machine type to file
3949 in @var{file}
3950 ETEXI
3952 STEXI
3953 @end table
3954 ETEXI
3955 DEFHEADING()
3957 DEFHEADING(Generic object creation:)
3958 STEXI
3959 @table @option
3960 ETEXI
3962 DEF("object", HAS_ARG, QEMU_OPTION_object,
3963 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3964 " create a new object of type TYPENAME setting properties\n"
3965 " in the order they are specified. Note that the 'id'\n"
3966 " property must be set. These objects are placed in the\n"
3967 " '/objects' path.\n",
3968 QEMU_ARCH_ALL)
3969 STEXI
3970 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3971 @findex -object
3972 Create a new object of type @var{typename} setting properties
3973 in the order they are specified. Note that the 'id'
3974 property must be set. These objects are placed in the
3975 '/objects' path.
3977 @table @option
3979 @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}
3981 Creates a memory file backend object, which can be used to back
3982 the guest RAM with huge pages.
3984 The @option{id} parameter is a unique ID that will be used to reference this
3985 memory region when configuring the @option{-numa} argument.
3987 The @option{size} option provides the size of the memory region, and accepts
3988 common suffixes, eg @option{500M}.
3990 The @option{mem-path} provides the path to either a shared memory or huge page
3991 filesystem mount.
3993 The @option{share} boolean option determines whether the memory
3994 region is marked as private to QEMU, or shared. The latter allows
3995 a co-operating external process to access the QEMU memory region.
3997 The @option{share} is also required for pvrdma devices due to
3998 limitations in the RDMA API provided by Linux.
4000 Setting share=on might affect the ability to configure NUMA
4001 bindings for the memory backend under some circumstances, see
4002 Documentation/vm/numa_memory_policy.txt on the Linux kernel
4003 source tree for additional details.
4005 Setting the @option{discard-data} boolean option to @var{on}
4006 indicates that file contents can be destroyed when QEMU exits,
4007 to avoid unnecessarily flushing data to the backing file. Note
4008 that @option{discard-data} is only an optimization, and QEMU
4009 might not discard file contents if it aborts unexpectedly or is
4010 terminated using SIGKILL.
4012 The @option{merge} boolean option enables memory merge, also known as
4013 MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
4014 memory deduplication.
4016 Setting the @option{dump} boolean option to @var{off} excludes the memory from
4017 core dumps. This feature is also known as MADV_DONTDUMP.
4019 The @option{prealloc} boolean option enables memory preallocation.
4021 The @option{host-nodes} option binds the memory range to a list of NUMA host
4022 nodes.
4024 The @option{policy} option sets the NUMA policy to one of the following values:
4026 @table @option
4027 @item @var{default}
4028 default host policy
4030 @item @var{preferred}
4031 prefer the given host node list for allocation
4033 @item @var{bind}
4034 restrict memory allocation to the given host node list
4036 @item @var{interleave}
4037 interleave memory allocations across the given host node list
4038 @end table
4040 The @option{align} option specifies the base address alignment when
4041 QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
4042 @option{2M}. Some backend store specified by @option{mem-path}
4043 requires an alignment different than the default one used by QEMU, eg
4044 the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4045 such cases, users can specify the required alignment via this option.
4047 @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}
4049 Creates a memory backend object, which can be used to back the guest RAM.
4050 Memory backend objects offer more control than the @option{-m} option that is
4051 traditionally used to define guest RAM. Please refer to
4052 @option{memory-backend-file} for a description of the options.
4054 @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}
4056 Creates an anonymous memory file backend object, which allows QEMU to
4057 share the memory with an external process (e.g. when using
4058 vhost-user). The memory is allocated with memfd and optional
4059 sealing. (Linux only)
4061 The @option{seal} option creates a sealed-file, that will block
4062 further resizing the memory ('on' by default).
4064 The @option{hugetlb} option specify the file to be created resides in
4065 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with
4066 the @option{hugetlb} option, the @option{hugetlbsize} option specify
4067 the hugetlb page size on systems that support multiple hugetlb page
4068 sizes (it must be a power of 2 value supported by the system).
4070 In some versions of Linux, the @option{hugetlb} option is incompatible
4071 with the @option{seal} option (requires at least Linux 4.16).
4073 Please refer to @option{memory-backend-file} for a description of the
4074 other options.
4076 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
4078 Creates a random number generator backend which obtains entropy from
4079 a device on the host. The @option{id} parameter is a unique ID that
4080 will be used to reference this entropy backend from the @option{virtio-rng}
4081 device. The @option{filename} parameter specifies which file to obtain
4082 entropy from and if omitted defaults to @option{/dev/random}.
4084 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4086 Creates a random number generator backend which obtains entropy from
4087 an external daemon running on the host. The @option{id} parameter is
4088 a unique ID that will be used to reference this entropy backend from
4089 the @option{virtio-rng} device. The @option{chardev} parameter is
4090 the unique ID of a character device backend that provides the connection
4091 to the RNG daemon.
4093 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4095 Creates a TLS anonymous credentials object, which can be used to provide
4096 TLS support on network backends. The @option{id} parameter is a unique
4097 ID which network backends will use to access the credentials. The
4098 @option{endpoint} is either @option{server} or @option{client} depending
4099 on whether the QEMU network backend that uses the credentials will be
4100 acting as a client or as a server. If @option{verify-peer} is enabled
4101 (the default) then once the handshake is completed, the peer credentials
4102 will be verified, though this is a no-op for anonymous credentials.
4104 The @var{dir} parameter tells QEMU where to find the credential
4105 files. For server endpoints, this directory may contain a file
4106 @var{dh-params.pem} providing diffie-hellman parameters to use
4107 for the TLS server. If the file is missing, QEMU will generate
4108 a set of DH parameters at startup. This is a computationally
4109 expensive operation that consumes random pool entropy, so it is
4110 recommended that a persistent set of parameters be generated
4111 upfront and saved.
4113 @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}
4115 Creates a TLS anonymous credentials object, which can be used to provide
4116 TLS support on network backends. The @option{id} parameter is a unique
4117 ID which network backends will use to access the credentials. The
4118 @option{endpoint} is either @option{server} or @option{client} depending
4119 on whether the QEMU network backend that uses the credentials will be
4120 acting as a client or as a server. If @option{verify-peer} is enabled
4121 (the default) then once the handshake is completed, the peer credentials
4122 will be verified. With x509 certificates, this implies that the clients
4123 must be provided with valid client certificates too.
4125 The @var{dir} parameter tells QEMU where to find the credential
4126 files. For server endpoints, this directory may contain a file
4127 @var{dh-params.pem} providing diffie-hellman parameters to use
4128 for the TLS server. If the file is missing, QEMU will generate
4129 a set of DH parameters at startup. This is a computationally
4130 expensive operation that consumes random pool entropy, so it is
4131 recommended that a persistent set of parameters be generated
4132 upfront and saved.
4134 For x509 certificate credentials the directory will contain further files
4135 providing the x509 certificates. The certificates must be stored
4136 in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4137 @var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4138 @var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4140 For the @var{server-key.pem} and @var{client-key.pem} files which
4141 contain sensitive private keys, it is possible to use an encrypted
4142 version by providing the @var{passwordid} parameter. This provides
4143 the ID of a previously created @code{secret} object containing the
4144 password for decryption.
4146 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4148 Interval @var{t} can't be 0, this filter batches the packet delivery: all
4149 packets arriving in a given interval on netdev @var{netdevid} are delayed
4150 until the end of the interval. Interval is in microseconds.
4151 @option{status} is optional that indicate whether the netfilter is
4152 on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4154 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4156 @option{all}: the filter is attached both to the receive and the transmit
4157 queue of the netdev (default).
4159 @option{rx}: the filter is attached to the receive queue of the netdev,
4160 where it will receive packets sent to the netdev.
4162 @option{tx}: the filter is attached to the transmit queue of the netdev,
4163 where it will receive packets sent by the netdev.
4165 @item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4167 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.
4169 @item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4171 filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4172 @var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4173 filter-redirector will redirect packet with vnet_hdr_len.
4174 Create a filter-redirector we need to differ outdev id from indev id, id can not
4175 be the same. we can just use indev or outdev, but at least one of indev or outdev
4176 need to be specified.
4178 @item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4180 Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4181 secondary from primary to keep secondary tcp connection,and rewrite
4182 tcp packet to primary from secondary make tcp packet can be handled by
4183 client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4185 usage:
4186 colo secondary:
4187 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4188 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4189 -object filter-rewriter,id=rew0,netdev=hn0,queue=all
4191 @item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4193 Dump the network traffic on netdev @var{dev} to the file specified by
4194 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4195 The file format is libpcap, so it can be analyzed with tools such as tcpdump
4196 or Wireshark.
4198 @item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4200 Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4201 secondary packet. If the packets are same, we will output primary
4202 packet to outdev@var{chardevid}, else we will notify colo-frame
4203 do checkpoint and send primary packet to outdev@var{chardevid}.
4204 if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4206 we must use it with the help of filter-mirror and filter-redirector.
4208 @example
4210 primary:
4211 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4212 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4213 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4214 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4215 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4216 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4217 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4218 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4219 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4220 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4221 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4222 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4224 secondary:
4225 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4226 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4227 -chardev socket,id=red0,host=3.3.3.3,port=9003
4228 -chardev socket,id=red1,host=3.3.3.3,port=9004
4229 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4230 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4232 @end example
4234 If you want to know the detail of above command line, you can read
4235 the colo-compare git log.
4237 @item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4239 Creates a cryptodev backend which executes crypto opreation from
4240 the QEMU cipher APIS. The @var{id} parameter is
4241 a unique ID that will be used to reference this cryptodev backend from
4242 the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4243 which specify the queue number of cryptodev backend, the default of
4244 @var{queues} is 1.
4246 @example
4248 # qemu-system-x86_64 \
4249 [...] \
4250 -object cryptodev-backend-builtin,id=cryptodev0 \
4251 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4252 [...]
4253 @end example
4255 @item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4257 Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4258 The @var{id} parameter is a unique ID that will be used to reference this
4259 cryptodev backend from the @option{virtio-crypto} device.
4260 The chardev should be a unix domain socket backed one. The vhost-user uses
4261 a specifically defined protocol to pass vhost ioctl replacement messages
4262 to an application on the other end of the socket.
4263 The @var{queues} parameter is optional, which specify the queue number
4264 of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4266 @example
4268 # qemu-system-x86_64 \
4269 [...] \
4270 -chardev socket,id=chardev0,path=/path/to/socket \
4271 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4272 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4273 [...]
4274 @end example
4276 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4277 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4279 Defines a secret to store a password, encryption key, or some other sensitive
4280 data. The sensitive data can either be passed directly via the @var{data}
4281 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4282 parameter is insecure unless the sensitive data is encrypted.
4284 The sensitive data can be provided in raw format (the default), or base64.
4285 When encoded as JSON, the raw format only supports valid UTF-8 characters,
4286 so base64 is recommended for sending binary data. QEMU will convert from
4287 which ever format is provided to the format it needs internally. eg, an
4288 RBD password can be provided in raw format, even though it will be base64
4289 encoded when passed onto the RBD sever.
4291 For added protection, it is possible to encrypt the data associated with
4292 a secret using the AES-256-CBC cipher. Use of encryption is indicated
4293 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4294 parameter provides the ID of a previously defined secret that contains
4295 the AES-256 decryption key. This key should be 32-bytes long and be
4296 base64 encoded. The @var{iv} parameter provides the random initialization
4297 vector used for encryption of this particular secret and should be a
4298 base64 encrypted string of the 16-byte IV.
4300 The simplest (insecure) usage is to provide the secret inline
4302 @example
4304 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4306 @end example
4308 The simplest secure usage is to provide the secret via a file
4310 # printf "letmein" > mypasswd.txt
4311 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4313 For greater security, AES-256-CBC should be used. To illustrate usage,
4314 consider the openssl command line tool which can encrypt the data. Note
4315 that when encrypting, the plaintext must be padded to the cipher block
4316 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4318 First a master key needs to be created in base64 encoding:
4320 @example
4321 # openssl rand -base64 32 > key.b64
4322 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
4323 @end example
4325 Each secret to be encrypted needs to have a random initialization vector
4326 generated. These do not need to be kept secret
4328 @example
4329 # openssl rand -base64 16 > iv.b64
4330 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
4331 @end example
4333 The secret to be defined can now be encrypted, in this case we're
4334 telling openssl to base64 encode the result, but it could be left
4335 as raw bytes if desired.
4337 @example
4338 # SECRET=$(printf "letmein" |
4339 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4340 @end example
4342 When launching QEMU, create a master secret pointing to @code{key.b64}
4343 and specify that to be used to decrypt the user password. Pass the
4344 contents of @code{iv.b64} to the second secret
4346 @example
4347 # $QEMU \
4348 -object secret,id=secmaster0,format=base64,file=key.b64 \
4349 -object secret,id=sec0,keyid=secmaster0,format=base64,\
4350 data=$SECRET,iv=$(<iv.b64)
4351 @end example
4353 @end table
4355 ETEXI
4358 HXCOMM This is the last statement. Insert new options before this line!
4359 STEXI
4360 @end table
4361 ETEXI