Remove the deprecated -balloon option
[qemu.git] / qemu-options.hx
blobccf7155454b0f10c94a7b463e32982173133da78
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 " memory-encryption=@var{} memory encryption object to use (default=none)\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 enforce-config-section=on|off
99 If @option{enforce-config-section} is set to @var{on}, force migration
100 code to send configuration section even if the machine-type sets the
101 @option{migration.send-configuration} property to @var{off}.
102 NOTE: this parameter is deprecated. Please use @option{-global}
103 @option{migration.send-configuration}=@var{on|off} instead.
104 @item memory-encryption=@var{}
105 Memory encryption object to use. The default is none.
106 @end table
107 ETEXI
109 HXCOMM Deprecated by -machine
110 DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
112 DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
113 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
114 STEXI
115 @item -cpu @var{model}
116 @findex -cpu
117 Select CPU model (@code{-cpu help} for list and additional feature selection)
118 ETEXI
120 DEF("accel", HAS_ARG, QEMU_OPTION_accel,
121 "-accel [accel=]accelerator[,thread=single|multi]\n"
122 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n"
123 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL)
124 STEXI
125 @item -accel @var{name}[,prop=@var{value}[,...]]
126 @findex -accel
127 This is used to enable an accelerator. Depending on the target architecture,
128 kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
129 more than one accelerator specified, the next one is used if the previous one
130 fails to initialize.
131 @table @option
132 @item thread=single|multi
133 Controls number of TCG threads. When the TCG is multi-threaded there will be one
134 thread per vCPU therefor taking advantage of additional host cores. The default
135 is to enable multi-threading where both the back-end and front-ends support it and
136 no incompatible TCG features have been enabled (e.g. icount/replay).
137 @end table
138 ETEXI
140 DEF("smp", HAS_ARG, QEMU_OPTION_smp,
141 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
142 " set the number of CPUs to 'n' [default=1]\n"
143 " maxcpus= maximum number of total cpus, including\n"
144 " offline CPUs for hotplug, etc\n"
145 " cores= number of CPU cores on one socket\n"
146 " threads= number of threads on one CPU core\n"
147 " sockets= number of discrete sockets in the system\n",
148 QEMU_ARCH_ALL)
149 STEXI
150 @item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
151 @findex -smp
152 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
153 CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
154 to 4.
155 For the PC target, the number of @var{cores} per socket, the number
156 of @var{threads} per cores and the total number of @var{sockets} can be
157 specified. Missing values will be computed. If any on the three values is
158 given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
159 specifies the maximum number of hotpluggable CPUs.
160 ETEXI
162 DEF("numa", HAS_ARG, QEMU_OPTION_numa,
163 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
164 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
165 "-numa dist,src=source,dst=destination,val=distance\n"
166 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n",
167 QEMU_ARCH_ALL)
168 STEXI
169 @item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
170 @itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
171 @itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance}
172 @itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}]
173 @findex -numa
174 Define a NUMA node and assign RAM and VCPUs to it.
175 Set the NUMA distance from a source node to a destination node.
177 Legacy VCPU assignment uses @samp{cpus} option where
178 @var{firstcpu} and @var{lastcpu} are CPU indexes. Each
179 @samp{cpus} option represent a contiguous range of CPU indexes
180 (or a single VCPU if @var{lastcpu} is omitted). A non-contiguous
181 set of VCPUs can be represented by providing multiple @samp{cpus}
182 options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically
183 split between them.
185 For example, the following option assigns VCPUs 0, 1, 2 and 5 to
186 a NUMA node:
187 @example
188 -numa node,cpus=0-2,cpus=5
189 @end example
191 @samp{cpu} option is a new alternative to @samp{cpus} option
192 which uses @samp{socket-id|core-id|thread-id} properties to assign
193 CPU objects to a @var{node} using topology layout properties of CPU.
194 The set of properties is machine specific, and depends on used
195 machine type/@samp{smp} options. It could be queried with
196 @samp{hotpluggable-cpus} monitor command.
197 @samp{node-id} property specifies @var{node} to which CPU object
198 will be assigned, it's required for @var{node} to be declared
199 with @samp{node} option before it's used with @samp{cpu} option.
201 For example:
202 @example
203 -M pc \
204 -smp 1,sockets=2,maxcpus=2 \
205 -numa node,nodeid=0 -numa node,nodeid=1 \
206 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
207 @end example
209 @samp{mem} assigns a given RAM amount to a node. @samp{memdev}
210 assigns RAM from a given memory backend device to a node. If
211 @samp{mem} and @samp{memdev} are omitted in all nodes, RAM is
212 split equally between them.
214 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
215 if one node uses @samp{memdev}, all of them have to use it.
217 @var{source} and @var{destination} are NUMA node IDs.
218 @var{distance} is the NUMA distance from @var{source} to @var{destination}.
219 The distance from a node to itself is always 10. If any pair of nodes is
220 given a distance, then all pairs must be given distances. Although, when
221 distances are only given in one direction for each pair of nodes, then
222 the distances in the opposite directions are assumed to be the same. If,
223 however, an asymmetrical pair of distances is given for even one node
224 pair, then all node pairs must be provided distance values for both
225 directions, even when they are symmetrical. When a node is unreachable
226 from another node, set the pair's distance to 255.
228 Note that the -@option{numa} option doesn't allocate any of the
229 specified resources, it just assigns existing resources to NUMA
230 nodes. This means that one still has to use the @option{-m},
231 @option{-smp} options to allocate RAM and VCPUs respectively.
233 ETEXI
235 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
236 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
237 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
238 STEXI
239 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
240 @findex -add-fd
242 Add a file descriptor to an fd set. Valid options are:
244 @table @option
245 @item fd=@var{fd}
246 This option defines the file descriptor of which a duplicate is added to fd set.
247 The file descriptor cannot be stdin, stdout, or stderr.
248 @item set=@var{set}
249 This option defines the ID of the fd set to add the file descriptor to.
250 @item opaque=@var{opaque}
251 This option defines a free-form string that can be used to describe @var{fd}.
252 @end table
254 You can open an image using pre-opened file descriptors from an fd set:
255 @example
256 qemu-system-i386
257 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
258 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
259 -drive file=/dev/fdset/2,index=0,media=disk
260 @end example
261 ETEXI
263 DEF("set", HAS_ARG, QEMU_OPTION_set,
264 "-set group.id.arg=value\n"
265 " set <arg> parameter for item <id> of type <group>\n"
266 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
267 STEXI
268 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
269 @findex -set
270 Set parameter @var{arg} for item @var{id} of type @var{group}
271 ETEXI
273 DEF("global", HAS_ARG, QEMU_OPTION_global,
274 "-global driver.property=value\n"
275 "-global driver=driver,property=property,value=value\n"
276 " set a global default for a driver property\n",
277 QEMU_ARCH_ALL)
278 STEXI
279 @item -global @var{driver}.@var{prop}=@var{value}
280 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
281 @findex -global
282 Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
284 @example
285 qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
286 @end example
288 In particular, you can use this to set driver properties for devices which are
289 created automatically by the machine model. To create a device which is not
290 created automatically and set properties on it, use -@option{device}.
292 -global @var{driver}.@var{prop}=@var{value} is shorthand for -global
293 driver=@var{driver},property=@var{prop},value=@var{value}. The
294 longhand syntax works even when @var{driver} contains a dot.
295 ETEXI
297 DEF("boot", HAS_ARG, QEMU_OPTION_boot,
298 "-boot [order=drives][,once=drives][,menu=on|off]\n"
299 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
300 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
301 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
302 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
303 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
304 QEMU_ARCH_ALL)
305 STEXI
306 @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]
307 @findex -boot
308 Specify boot order @var{drives} as a string of drive letters. Valid
309 drive letters depend on the target architecture. The x86 PC uses: a, b
310 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
311 from network adapter 1-4), hard disk boot is the default. To apply a
312 particular boot order only on the first startup, specify it via
313 @option{once}. Note that the @option{order} or @option{once} parameter
314 should not be used together with the @option{bootindex} property of
315 devices, since the firmware implementations normally do not support both
316 at the same time.
318 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
319 as firmware/BIOS supports them. The default is non-interactive boot.
321 A splash picture could be passed to bios, enabling user to show it as logo,
322 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
323 supports them. Currently Seabios for X86 system support it.
324 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
325 format(true color). The resolution should be supported by the SVGA mode, so
326 the recommended is 320x240, 640x480, 800x640.
328 A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
329 when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
330 reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
331 system support it.
333 Do strict boot via @option{strict=on} as far as firmware/BIOS
334 supports it. This only effects when boot priority is changed by
335 bootindex options. The default is non-strict boot.
337 @example
338 # try to boot from network first, then from hard disk
339 qemu-system-i386 -boot order=nc
340 # boot from CD-ROM first, switch back to default order after reboot
341 qemu-system-i386 -boot once=d
342 # boot with a splash picture for 5 seconds.
343 qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
344 @end example
346 Note: The legacy format '-boot @var{drives}' is still supported but its
347 use is discouraged as it may be removed from future versions.
348 ETEXI
350 DEF("m", HAS_ARG, QEMU_OPTION_m,
351 "-m [size=]megs[,slots=n,maxmem=size]\n"
352 " configure guest RAM\n"
353 " size: initial amount of guest memory\n"
354 " slots: number of hotplug slots (default: none)\n"
355 " maxmem: maximum amount of guest memory (default: none)\n"
356 "NOTE: Some architectures might enforce a specific granularity\n",
357 QEMU_ARCH_ALL)
358 STEXI
359 @item -m [size=]@var{megs}[,slots=n,maxmem=size]
360 @findex -m
361 Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
362 Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
363 megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
364 could be used to set amount of hotpluggable memory slots and maximum amount of
365 memory. Note that @var{maxmem} must be aligned to the page size.
367 For example, the following command-line sets the guest startup RAM size to
368 1GB, creates 3 slots to hotplug additional memory and sets the maximum
369 memory the guest can reach to 4GB:
371 @example
372 qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
373 @end example
375 If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
376 be enabled and the guest startup RAM will never increase.
377 ETEXI
379 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
380 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
381 STEXI
382 @item -mem-path @var{path}
383 @findex -mem-path
384 Allocate guest RAM from a temporarily created file in @var{path}.
385 ETEXI
387 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
388 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
389 QEMU_ARCH_ALL)
390 STEXI
391 @item -mem-prealloc
392 @findex -mem-prealloc
393 Preallocate memory when using -mem-path.
394 ETEXI
396 DEF("k", HAS_ARG, QEMU_OPTION_k,
397 "-k language use keyboard layout (for example 'fr' for French)\n",
398 QEMU_ARCH_ALL)
399 STEXI
400 @item -k @var{language}
401 @findex -k
402 Use keyboard layout @var{language} (for example @code{fr} for
403 French). This option is only needed where it is not easy to get raw PC
404 keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
405 display). You don't normally need to use it on PC/Linux or PC/Windows
406 hosts.
408 The available layouts are:
409 @example
410 ar de-ch es fo fr-ca hu ja mk no pt-br sv
411 da en-gb et fr fr-ch is lt nl pl ru th
412 de en-us fi fr-be hr it lv nl-be pt sl tr
413 @end example
415 The default is @code{en-us}.
416 ETEXI
419 DEF("audio-help", 0, QEMU_OPTION_audio_help,
420 "-audio-help print list of audio drivers and their options\n",
421 QEMU_ARCH_ALL)
422 STEXI
423 @item -audio-help
424 @findex -audio-help
425 Will show the audio subsystem help: list of drivers, tunable
426 parameters.
427 ETEXI
429 DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
430 "-soundhw c1,... enable audio support\n"
431 " and only specified sound cards (comma separated list)\n"
432 " use '-soundhw help' to get the list of supported cards\n"
433 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
434 STEXI
435 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
436 @findex -soundhw
437 Enable audio and selected sound hardware. Use 'help' to print all
438 available sound hardware.
440 @example
441 qemu-system-i386 -soundhw sb16,adlib disk.img
442 qemu-system-i386 -soundhw es1370 disk.img
443 qemu-system-i386 -soundhw ac97 disk.img
444 qemu-system-i386 -soundhw hda disk.img
445 qemu-system-i386 -soundhw all disk.img
446 qemu-system-i386 -soundhw help
447 @end example
449 Note that Linux's i810_audio OSS kernel (for AC97) module might
450 require manually specifying clocking.
452 @example
453 modprobe i810_audio clocking=48000
454 @end example
455 ETEXI
457 DEF("device", HAS_ARG, QEMU_OPTION_device,
458 "-device driver[,prop[=value][,...]]\n"
459 " add device (based on driver)\n"
460 " prop=value,... sets driver properties\n"
461 " use '-device help' to print all possible drivers\n"
462 " use '-device driver,help' to print all possible properties\n",
463 QEMU_ARCH_ALL)
464 STEXI
465 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
466 @findex -device
467 Add device @var{driver}. @var{prop}=@var{value} sets driver
468 properties. Valid properties depend on the driver. To get help on
469 possible drivers and properties, use @code{-device help} and
470 @code{-device @var{driver},help}.
472 Some drivers are:
473 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
475 Add an IPMI BMC. This is a simulation of a hardware management
476 interface processor that normally sits on a system. It provides
477 a watchdog and the ability to reset and power control the system.
478 You need to connect this to an IPMI interface to make it useful
480 The IPMI slave address to use for the BMC. The default is 0x20.
481 This address is the BMC's address on the I2C network of management
482 controllers. If you don't know what this means, it is safe to ignore
485 @table @option
486 @item bmc=@var{id}
487 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
488 @item slave_addr=@var{val}
489 Define slave address to use for the BMC. The default is 0x20.
490 @item sdrfile=@var{file}
491 file containing raw Sensor Data Records (SDR) data. The default is none.
492 @item fruareasize=@var{val}
493 size of a Field Replaceable Unit (FRU) area. The default is 1024.
494 @item frudatafile=@var{file}
495 file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
496 @end table
498 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
500 Add a connection to an external IPMI BMC simulator. Instead of
501 locally emulating the BMC like the above item, instead connect
502 to an external entity that provides the IPMI services.
504 A connection is made to an external BMC simulator. If you do this, it
505 is strongly recommended that you use the "reconnect=" chardev option
506 to reconnect to the simulator if the connection is lost. Note that if
507 this is not used carefully, it can be a security issue, as the
508 interface has the ability to send resets, NMIs, and power off the VM.
509 It's best if QEMU makes a connection to an external simulator running
510 on a secure port on localhost, so neither the simulator nor QEMU is
511 exposed to any outside network.
513 See the "lanserv/README.vm" file in the OpenIPMI library for more
514 details on the external interface.
516 @item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
518 Add a KCS IPMI interafce on the ISA bus. This also adds a
519 corresponding ACPI and SMBIOS entries, if appropriate.
521 @table @option
522 @item bmc=@var{id}
523 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
524 @item ioport=@var{val}
525 Define the I/O address of the interface. The default is 0xca0 for KCS.
526 @item irq=@var{val}
527 Define the interrupt to use. The default is 5. To disable interrupts,
528 set this to 0.
529 @end table
531 @item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
533 Like the KCS interface, but defines a BT interface. The default port is
534 0xe4 and the default interrupt is 5.
536 ETEXI
538 DEF("name", HAS_ARG, QEMU_OPTION_name,
539 "-name string1[,process=string2][,debug-threads=on|off]\n"
540 " set the name of the guest\n"
541 " string1 sets the window title and string2 the process name (on Linux)\n"
542 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
543 " NOTE: The thread names are for debugging and not a stable API.\n",
544 QEMU_ARCH_ALL)
545 STEXI
546 @item -name @var{name}
547 @findex -name
548 Sets the @var{name} of the guest.
549 This name will be displayed in the SDL window caption.
550 The @var{name} will also be used for the VNC server.
551 Also optionally set the top visible process name in Linux.
552 Naming of individual threads can also be enabled on Linux to aid debugging.
553 ETEXI
555 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
556 "-uuid %08x-%04x-%04x-%04x-%012x\n"
557 " specify machine UUID\n", QEMU_ARCH_ALL)
558 STEXI
559 @item -uuid @var{uuid}
560 @findex -uuid
561 Set system UUID.
562 ETEXI
564 STEXI
565 @end table
566 ETEXI
567 DEFHEADING()
569 DEFHEADING(Block device options:)
570 STEXI
571 @table @option
572 ETEXI
574 DEF("fda", HAS_ARG, QEMU_OPTION_fda,
575 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
576 DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
577 STEXI
578 @item -fda @var{file}
579 @itemx -fdb @var{file}
580 @findex -fda
581 @findex -fdb
582 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
583 ETEXI
585 DEF("hda", HAS_ARG, QEMU_OPTION_hda,
586 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
587 DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
588 DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
589 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
590 DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
591 STEXI
592 @item -hda @var{file}
593 @itemx -hdb @var{file}
594 @itemx -hdc @var{file}
595 @itemx -hdd @var{file}
596 @findex -hda
597 @findex -hdb
598 @findex -hdc
599 @findex -hdd
600 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
601 ETEXI
603 DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
604 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
605 QEMU_ARCH_ALL)
606 STEXI
607 @item -cdrom @var{file}
608 @findex -cdrom
609 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
610 @option{-cdrom} at the same time). You can use the host CD-ROM by
611 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
612 ETEXI
614 DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
615 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
616 " [,cache.direct=on|off][,cache.no-flush=on|off]\n"
617 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
618 " [,driver specific parameters...]\n"
619 " configure a block backend\n", QEMU_ARCH_ALL)
620 STEXI
621 @item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
622 @findex -blockdev
624 Define a new block driver node. Some of the options apply to all block drivers,
625 other options are only accepted for a specific block driver. See below for a
626 list of generic options and options for the most common block drivers.
628 Options that expect a reference to another node (e.g. @code{file}) can be
629 given in two ways. Either you specify the node name of an already existing node
630 (file=@var{node-name}), or you define a new node inline, adding options
631 for the referenced node after a dot (file.filename=@var{path},file.aio=native).
633 A block driver node created with @option{-blockdev} can be used for a guest
634 device by specifying its node name for the @code{drive} property in a
635 @option{-device} argument that defines a block device.
637 @table @option
638 @item Valid options for any block driver node:
640 @table @code
641 @item driver
642 Specifies the block driver to use for the given node.
643 @item node-name
644 This defines the name of the block driver node by which it will be referenced
645 later. The name must be unique, i.e. it must not match the name of a different
646 block driver node, or (if you use @option{-drive} as well) the ID of a drive.
648 If no node name is specified, it is automatically generated. The generated node
649 name is not intended to be predictable and changes between QEMU invocations.
650 For the top level, an explicit node name must be specified.
651 @item read-only
652 Open the node read-only. Guest write attempts will fail.
653 @item cache.direct
654 The host page cache can be avoided with @option{cache.direct=on}. This will
655 attempt to do disk IO directly to the guest's memory. QEMU may still perform an
656 internal copy of the data.
657 @item cache.no-flush
658 In case you don't care about data integrity over host failures, you can use
659 @option{cache.no-flush=on}. This option tells QEMU that it never needs to write
660 any data to the disk but can instead keep things in cache. If anything goes
661 wrong, like your host losing power, the disk storage getting disconnected
662 accidentally, etc. your image will most probably be rendered unusable.
663 @item discard=@var{discard}
664 @var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls
665 whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
666 ignored or passed to the filesystem. Some machine types may not support
667 discard requests.
668 @item detect-zeroes=@var{detect-zeroes}
669 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
670 conversion of plain zero writes by the OS to driver specific optimized
671 zero write commands. You may even choose "unmap" if @var{discard} is set
672 to "unmap" to allow a zero write to be converted to an @code{unmap} operation.
673 @end table
675 @item Driver-specific options for @code{file}
677 This is the protocol-level block driver for accessing regular files.
679 @table @code
680 @item filename
681 The path to the image file in the local filesystem
682 @item aio
683 Specifies the AIO backend (threads/native, default: threads)
684 @item locking
685 Specifies whether the image file is protected with Linux OFD / POSIX locks. The
686 default is to use the Linux Open File Descriptor API if available, otherwise no
687 lock is applied. (auto/on/off, default: auto)
688 @end table
689 Example:
690 @example
691 -blockdev driver=file,node-name=disk,filename=disk.img
692 @end example
694 @item Driver-specific options for @code{raw}
696 This is the image format block driver for raw images. It is usually
697 stacked on top of a protocol level block driver such as @code{file}.
699 @table @code
700 @item file
701 Reference to or definition of the data source block driver node
702 (e.g. a @code{file} driver node)
703 @end table
704 Example 1:
705 @example
706 -blockdev driver=file,node-name=disk_file,filename=disk.img
707 -blockdev driver=raw,node-name=disk,file=disk_file
708 @end example
709 Example 2:
710 @example
711 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
712 @end example
714 @item Driver-specific options for @code{qcow2}
716 This is the image format block driver for qcow2 images. It is usually
717 stacked on top of a protocol level block driver such as @code{file}.
719 @table @code
720 @item file
721 Reference to or definition of the data source block driver node
722 (e.g. a @code{file} driver node)
724 @item backing
725 Reference to or definition of the backing file block device (default is taken
726 from the image file). It is allowed to pass @code{null} here in order to disable
727 the default backing file.
729 @item lazy-refcounts
730 Whether to enable the lazy refcounts feature (on/off; default is taken from the
731 image file)
733 @item cache-size
734 The maximum total size of the L2 table and refcount block caches in bytes
735 (default: 1048576 bytes or 8 clusters, whichever is larger)
737 @item l2-cache-size
738 The maximum size of the L2 table cache in bytes
739 (default: 4/5 of the total cache size)
741 @item refcount-cache-size
742 The maximum size of the refcount block cache in bytes
743 (default: 1/5 of the total cache size)
745 @item cache-clean-interval
746 Clean unused entries in the L2 and refcount caches. The interval is in seconds.
747 The default value is 0 and it disables this feature.
749 @item pass-discard-request
750 Whether discard requests to the qcow2 device should be forwarded to the data
751 source (on/off; default: on if discard=unmap is specified, off otherwise)
753 @item pass-discard-snapshot
754 Whether discard requests for the data source should be issued when a snapshot
755 operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
756 default: on)
758 @item pass-discard-other
759 Whether discard requests for the data source should be issued on other
760 occasions where a cluster gets freed (on/off; default: off)
762 @item overlap-check
763 Which overlap checks to perform for writes to the image
764 (none/constant/cached/all; default: cached). For details or finer
765 granularity control refer to the QAPI documentation of @code{blockdev-add}.
766 @end table
768 Example 1:
769 @example
770 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
771 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
772 @end example
773 Example 2:
774 @example
775 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
776 @end example
778 @item Driver-specific options for other drivers
779 Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
781 @end table
783 ETEXI
785 DEF("drive", HAS_ARG, QEMU_OPTION_drive,
786 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
787 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
788 " [,snapshot=on|off][,rerror=ignore|stop|report]\n"
789 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
790 " [,readonly=on|off][,copy-on-read=on|off]\n"
791 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
792 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
793 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
794 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
795 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
796 " [[,iops_size=is]]\n"
797 " [[,group=g]]\n"
798 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
799 STEXI
800 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
801 @findex -drive
803 Define a new drive. This includes creating a block driver node (the backend) as
804 well as a guest device, and is mostly a shortcut for defining the corresponding
805 @option{-blockdev} and @option{-device} options.
807 @option{-drive} accepts all options that are accepted by @option{-blockdev}. In
808 addition, it knows the following options:
810 @table @option
811 @item file=@var{file}
812 This option defines which disk image (@pxref{disk_images}) to use with
813 this drive. If the filename contains comma, you must double it
814 (for instance, "file=my,,file" to use file "my,file").
816 Special files such as iSCSI devices can be specified using protocol
817 specific URLs. See the section for "Device URL Syntax" for more information.
818 @item if=@var{interface}
819 This option defines on which type on interface the drive is connected.
820 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
821 @item bus=@var{bus},unit=@var{unit}
822 These options define where is connected the drive by defining the bus number and
823 the unit id.
824 @item index=@var{index}
825 This option defines where is connected the drive by using an index in the list
826 of available connectors of a given interface type.
827 @item media=@var{media}
828 This option defines the type of the media: disk or cdrom.
829 @item snapshot=@var{snapshot}
830 @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
831 (see @option{-snapshot}).
832 @item cache=@var{cache}
833 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
834 and controls how the host cache is used to access block data. This is a
835 shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
836 options (as in @option{-blockdev}), and additionally @option{cache.writeback},
837 which provides a default for the @option{write-cache} option of block guest
838 devices (as in @option{-device}). The modes correspond to the following
839 settings:
841 @c Our texi2pod.pl script doesn't support @multitable, so fall back to using
842 @c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
843 @c and the HTML output.
844 @example
845 @ │ cache.writeback cache.direct cache.no-flush
846 ─────────────┼─────────────────────────────────────────────────
847 writeback │ on off off
848 none │ on on off
849 writethrough │ off off off
850 directsync │ off on off
851 unsafe │ on off on
852 @end example
854 The default mode is @option{cache=writeback}.
856 @item aio=@var{aio}
857 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
858 @item format=@var{format}
859 Specify which disk @var{format} will be used rather than detecting
860 the format. Can be used to specify format=raw to avoid interpreting
861 an untrusted format header.
862 @item werror=@var{action},rerror=@var{action}
863 Specify which @var{action} to take on write and read errors. Valid actions are:
864 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
865 "report" (report the error to the guest), "enospc" (pause QEMU only if the
866 host disk is full; report the error to the guest otherwise).
867 The default setting is @option{werror=enospc} and @option{rerror=report}.
868 @item copy-on-read=@var{copy-on-read}
869 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
870 file sectors into the image file.
871 @item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
872 Specify bandwidth throttling limits in bytes per second, either for all request
873 types or for reads or writes only. Small values can lead to timeouts or hangs
874 inside the guest. A safe minimum for disks is 2 MB/s.
875 @item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
876 Specify bursts in bytes per second, either for all request types or for reads
877 or writes only. Bursts allow the guest I/O to spike above the limit
878 temporarily.
879 @item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
880 Specify request rate limits in requests per second, either for all request
881 types or for reads or writes only.
882 @item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
883 Specify bursts in requests per second, either for all request types or for reads
884 or writes only. Bursts allow the guest I/O to spike above the limit
885 temporarily.
886 @item iops_size=@var{is}
887 Let every @var{is} bytes of a request count as a new request for iops
888 throttling purposes. Use this option to prevent guests from circumventing iops
889 limits by sending fewer but larger requests.
890 @item group=@var{g}
891 Join a throttling quota group with given name @var{g}. All drives that are
892 members of the same group are accounted for together. Use this option to
893 prevent guests from circumventing throttling limits by using many small disks
894 instead of a single larger disk.
895 @end table
897 By default, the @option{cache.writeback=on} mode is used. It will report data
898 writes as completed as soon as the data is present in the host page cache.
899 This is safe as long as your guest OS makes sure to correctly flush disk caches
900 where needed. If your guest OS does not handle volatile disk write caches
901 correctly and your host crashes or loses power, then the guest may experience
902 data corruption.
904 For such guests, you should consider using @option{cache.writeback=off}. This
905 means that the host page cache will be used to read and write data, but write
906 notification will be sent to the guest only after QEMU has made sure to flush
907 each write to the disk. Be aware that this has a major impact on performance.
909 When using the @option{-snapshot} option, unsafe caching is always used.
911 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
912 useful when the backing file is over a slow network. By default copy-on-read
913 is off.
915 Instead of @option{-cdrom} you can use:
916 @example
917 qemu-system-i386 -drive file=file,index=2,media=cdrom
918 @end example
920 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
921 use:
922 @example
923 qemu-system-i386 -drive file=file,index=0,media=disk
924 qemu-system-i386 -drive file=file,index=1,media=disk
925 qemu-system-i386 -drive file=file,index=2,media=disk
926 qemu-system-i386 -drive file=file,index=3,media=disk
927 @end example
929 You can open an image using pre-opened file descriptors from an fd set:
930 @example
931 qemu-system-i386
932 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
933 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
934 -drive file=/dev/fdset/2,index=0,media=disk
935 @end example
937 You can connect a CDROM to the slave of ide0:
938 @example
939 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
940 @end example
942 If you don't specify the "file=" argument, you define an empty drive:
943 @example
944 qemu-system-i386 -drive if=ide,index=1,media=cdrom
945 @end example
947 Instead of @option{-fda}, @option{-fdb}, you can use:
948 @example
949 qemu-system-i386 -drive file=file,index=0,if=floppy
950 qemu-system-i386 -drive file=file,index=1,if=floppy
951 @end example
953 By default, @var{interface} is "ide" and @var{index} is automatically
954 incremented:
955 @example
956 qemu-system-i386 -drive file=a -drive file=b"
957 @end example
958 is interpreted like:
959 @example
960 qemu-system-i386 -hda a -hdb b
961 @end example
962 ETEXI
964 DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
965 "-mtdblock file use 'file' as on-board Flash memory image\n",
966 QEMU_ARCH_ALL)
967 STEXI
968 @item -mtdblock @var{file}
969 @findex -mtdblock
970 Use @var{file} as on-board Flash memory image.
971 ETEXI
973 DEF("sd", HAS_ARG, QEMU_OPTION_sd,
974 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
975 STEXI
976 @item -sd @var{file}
977 @findex -sd
978 Use @var{file} as SecureDigital card image.
979 ETEXI
981 DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
982 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
983 STEXI
984 @item -pflash @var{file}
985 @findex -pflash
986 Use @var{file} as a parallel flash image.
987 ETEXI
989 DEF("snapshot", 0, QEMU_OPTION_snapshot,
990 "-snapshot write to temporary files instead of disk image files\n",
991 QEMU_ARCH_ALL)
992 STEXI
993 @item -snapshot
994 @findex -snapshot
995 Write to temporary files instead of disk image files. In this case,
996 the raw disk image you use is not written back. You can however force
997 the write back by pressing @key{C-a s} (@pxref{disk_images}).
998 ETEXI
1000 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
1001 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1002 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1003 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1004 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1005 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1006 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1007 " [[,throttling.iops-size=is]]\n",
1008 QEMU_ARCH_ALL)
1010 STEXI
1012 @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}]
1013 @findex -fsdev
1014 Define a new file system device. Valid options are:
1015 @table @option
1016 @item @var{fsdriver}
1017 This option specifies the fs driver backend to use.
1018 Currently "local", "handle" and "proxy" file system drivers are supported.
1019 @item id=@var{id}
1020 Specifies identifier for this device
1021 @item path=@var{path}
1022 Specifies the export path for the file system device. Files under
1023 this path will be available to the 9p client on the guest.
1024 @item security_model=@var{security_model}
1025 Specifies the security model to be used for this export path.
1026 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1027 In "passthrough" security model, files are stored using the same
1028 credentials as they are created on the guest. This requires QEMU
1029 to run as root. In "mapped-xattr" security model, some of the file
1030 attributes like uid, gid, mode bits and link target are stored as
1031 file attributes. For "mapped-file" these attributes are stored in the
1032 hidden .virtfs_metadata directory. Directories exported by this security model cannot
1033 interact with other unix tools. "none" security model is same as
1034 passthrough except the sever won't report failures if it fails to
1035 set file attributes like ownership. Security model is mandatory
1036 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
1037 security model as a parameter.
1038 @item writeout=@var{writeout}
1039 This is an optional argument. The only supported value is "immediate".
1040 This means that host page cache will be used to read and write data but
1041 write notification will be sent to the guest only when the data has been
1042 reported as written by the storage subsystem.
1043 @item readonly
1044 Enables exporting 9p share as a readonly mount for guests. By default
1045 read-write access is given.
1046 @item socket=@var{socket}
1047 Enables proxy filesystem driver to use passed socket file for communicating
1048 with virtfs-proxy-helper
1049 @item sock_fd=@var{sock_fd}
1050 Enables proxy filesystem driver to use passed socket descriptor for
1051 communicating with virtfs-proxy-helper. Usually a helper like libvirt
1052 will create socketpair and pass one of the fds as sock_fd
1053 @item fmode=@var{fmode}
1054 Specifies the default mode for newly created files on the host. Works only
1055 with security models "mapped-xattr" and "mapped-file".
1056 @item dmode=@var{dmode}
1057 Specifies the default mode for newly created directories on the host. Works
1058 only with security models "mapped-xattr" and "mapped-file".
1059 @end table
1061 -fsdev option is used along with -device driver "virtio-9p-pci".
1062 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
1063 Options for virtio-9p-pci driver are:
1064 @table @option
1065 @item fsdev=@var{id}
1066 Specifies the id value specified along with -fsdev option
1067 @item mount_tag=@var{mount_tag}
1068 Specifies the tag name to be used by the guest to mount this export point
1069 @end table
1071 ETEXI
1073 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
1074 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1075 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1076 QEMU_ARCH_ALL)
1078 STEXI
1080 @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}]
1081 @findex -virtfs
1083 The general form of a Virtual File system pass-through options are:
1084 @table @option
1085 @item @var{fsdriver}
1086 This option specifies the fs driver backend to use.
1087 Currently "local", "handle" and "proxy" file system drivers are supported.
1088 @item id=@var{id}
1089 Specifies identifier for this device
1090 @item path=@var{path}
1091 Specifies the export path for the file system device. Files under
1092 this path will be available to the 9p client on the guest.
1093 @item security_model=@var{security_model}
1094 Specifies the security model to be used for this export path.
1095 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1096 In "passthrough" security model, files are stored using the same
1097 credentials as they are created on the guest. This requires QEMU
1098 to run as root. In "mapped-xattr" security model, some of the file
1099 attributes like uid, gid, mode bits and link target are stored as
1100 file attributes. For "mapped-file" these attributes are stored in the
1101 hidden .virtfs_metadata directory. Directories exported by this security model cannot
1102 interact with other unix tools. "none" security model is same as
1103 passthrough except the sever won't report failures if it fails to
1104 set file attributes like ownership. Security model is mandatory only
1105 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
1106 model as a parameter.
1107 @item writeout=@var{writeout}
1108 This is an optional argument. The only supported value is "immediate".
1109 This means that host page cache will be used to read and write data but
1110 write notification will be sent to the guest only when the data has been
1111 reported as written by the storage subsystem.
1112 @item readonly
1113 Enables exporting 9p share as a readonly mount for guests. By default
1114 read-write access is given.
1115 @item socket=@var{socket}
1116 Enables proxy filesystem driver to use passed socket file for
1117 communicating with virtfs-proxy-helper. Usually a helper like libvirt
1118 will create socketpair and pass one of the fds as sock_fd
1119 @item sock_fd
1120 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
1121 descriptor for interfacing with virtfs-proxy-helper
1122 @item fmode=@var{fmode}
1123 Specifies the default mode for newly created files on the host. Works only
1124 with security models "mapped-xattr" and "mapped-file".
1125 @item dmode=@var{dmode}
1126 Specifies the default mode for newly created directories on the host. Works
1127 only with security models "mapped-xattr" and "mapped-file".
1128 @end table
1129 ETEXI
1131 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
1132 "-virtfs_synth Create synthetic file system image\n",
1133 QEMU_ARCH_ALL)
1134 STEXI
1135 @item -virtfs_synth
1136 @findex -virtfs_synth
1137 Create synthetic file system image
1138 ETEXI
1140 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1141 "-iscsi [user=user][,password=password]\n"
1142 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1143 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1144 " [,timeout=timeout]\n"
1145 " iSCSI session parameters\n", QEMU_ARCH_ALL)
1147 STEXI
1148 @item -iscsi
1149 @findex -iscsi
1150 Configure iSCSI session parameters.
1151 ETEXI
1153 STEXI
1154 @end table
1155 ETEXI
1156 DEFHEADING()
1158 DEFHEADING(USB options:)
1159 STEXI
1160 @table @option
1161 ETEXI
1163 DEF("usb", 0, QEMU_OPTION_usb,
1164 "-usb enable the USB driver (if it is not used by default yet)\n",
1165 QEMU_ARCH_ALL)
1166 STEXI
1167 @item -usb
1168 @findex -usb
1169 Enable the USB driver (if it is not used by default yet).
1170 ETEXI
1172 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1173 "-usbdevice name add the host or guest USB device 'name'\n",
1174 QEMU_ARCH_ALL)
1175 STEXI
1177 @item -usbdevice @var{devname}
1178 @findex -usbdevice
1179 Add the USB device @var{devname}. Note that this option is deprecated,
1180 please use @code{-device usb-...} instead. @xref{usb_devices}.
1182 @table @option
1184 @item mouse
1185 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1187 @item tablet
1188 Pointer device that uses absolute coordinates (like a touchscreen). This
1189 means QEMU is able to report the mouse position without having to grab the
1190 mouse. Also overrides the PS/2 mouse emulation when activated.
1192 @item braille
1193 Braille device. This will use BrlAPI to display the braille output on a real
1194 or fake device.
1196 @end table
1197 ETEXI
1199 STEXI
1200 @end table
1201 ETEXI
1202 DEFHEADING()
1204 DEFHEADING(Display options:)
1205 STEXI
1206 @table @option
1207 ETEXI
1209 DEF("display", HAS_ARG, QEMU_OPTION_display,
1210 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1211 " [,window_close=on|off][,gl=on|core|es|off]\n"
1212 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1213 "-display vnc=<display>[,<optargs>]\n"
1214 "-display curses\n"
1215 "-display none"
1216 " select display type\n"
1217 "The default display is equivalent to\n"
1218 #if defined(CONFIG_GTK)
1219 "\t\"-display gtk\"\n"
1220 #elif defined(CONFIG_SDL)
1221 "\t\"-display sdl\"\n"
1222 #elif defined(CONFIG_COCOA)
1223 "\t\"-display cocoa\"\n"
1224 #elif defined(CONFIG_VNC)
1225 "\t\"-vnc localhost:0,to=99,id=default\"\n"
1226 #else
1227 "\t\"-display none\"\n"
1228 #endif
1229 , QEMU_ARCH_ALL)
1230 STEXI
1231 @item -display @var{type}
1232 @findex -display
1233 Select type of display to use. This option is a replacement for the
1234 old style -sdl/-curses/... options. Valid values for @var{type} are
1235 @table @option
1236 @item sdl
1237 Display video output via SDL (usually in a separate graphics
1238 window; see the SDL documentation for other possibilities).
1239 @item curses
1240 Display video output via curses. For graphics device models which
1241 support a text mode, QEMU can display this output using a
1242 curses/ncurses interface. Nothing is displayed when the graphics
1243 device is in graphical mode or if the graphics device does not support
1244 a text mode. Generally only the VGA device models support text mode.
1245 @item none
1246 Do not display video output. The guest will still see an emulated
1247 graphics card, but its output will not be displayed to the QEMU
1248 user. This option differs from the -nographic option in that it
1249 only affects what is done with video output; -nographic also changes
1250 the destination of the serial and parallel port data.
1251 @item gtk
1252 Display video output in a GTK window. This interface provides drop-down
1253 menus and other UI elements to configure and control the VM during
1254 runtime.
1255 @item vnc
1256 Start a VNC server on display <arg>
1257 @end table
1258 ETEXI
1260 DEF("nographic", 0, QEMU_OPTION_nographic,
1261 "-nographic disable graphical output and redirect serial I/Os to console\n",
1262 QEMU_ARCH_ALL)
1263 STEXI
1264 @item -nographic
1265 @findex -nographic
1266 Normally, if QEMU is compiled with graphical window support, it displays
1267 output such as guest graphics, guest console, and the QEMU monitor in a
1268 window. With this option, you can totally disable graphical output so
1269 that QEMU is a simple command line application. The emulated serial port
1270 is redirected on the console and muxed with the monitor (unless
1271 redirected elsewhere explicitly). Therefore, you can still use QEMU to
1272 debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1273 switching between the console and monitor.
1274 ETEXI
1276 DEF("curses", 0, QEMU_OPTION_curses,
1277 "-curses shorthand for -display curses\n",
1278 QEMU_ARCH_ALL)
1279 STEXI
1280 @item -curses
1281 @findex -curses
1282 Normally, if QEMU is compiled with graphical window support, it displays
1283 output such as guest graphics, guest console, and the QEMU monitor in a
1284 window. With this option, QEMU can display the VGA output when in text
1285 mode using a curses/ncurses interface. Nothing is displayed in graphical
1286 mode.
1287 ETEXI
1289 DEF("no-frame", 0, QEMU_OPTION_no_frame,
1290 "-no-frame open SDL window without a frame and window decorations\n",
1291 QEMU_ARCH_ALL)
1292 STEXI
1293 @item -no-frame
1294 @findex -no-frame
1295 Do not use decorations for SDL windows and start them using the whole
1296 available screen space. This makes the using QEMU in a dedicated desktop
1297 workspace more convenient.
1298 ETEXI
1300 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1301 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1302 QEMU_ARCH_ALL)
1303 STEXI
1304 @item -alt-grab
1305 @findex -alt-grab
1306 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1307 affects the special keys (for fullscreen, monitor-mode switching, etc).
1308 ETEXI
1310 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1311 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1312 QEMU_ARCH_ALL)
1313 STEXI
1314 @item -ctrl-grab
1315 @findex -ctrl-grab
1316 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1317 affects the special keys (for fullscreen, monitor-mode switching, etc).
1318 ETEXI
1320 DEF("no-quit", 0, QEMU_OPTION_no_quit,
1321 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
1322 STEXI
1323 @item -no-quit
1324 @findex -no-quit
1325 Disable SDL window close capability.
1326 ETEXI
1328 DEF("sdl", 0, QEMU_OPTION_sdl,
1329 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL)
1330 STEXI
1331 @item -sdl
1332 @findex -sdl
1333 Enable SDL.
1334 ETEXI
1336 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1337 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1338 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1339 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1340 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1341 " [,tls-ciphers=<list>]\n"
1342 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1343 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1344 " [,sasl][,password=<secret>][,disable-ticketing]\n"
1345 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1346 " [,jpeg-wan-compression=[auto|never|always]]\n"
1347 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
1348 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1349 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1350 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1351 " [,gl=[on|off]][,rendernode=<file>]\n"
1352 " enable spice\n"
1353 " at least one of {port, tls-port} is mandatory\n",
1354 QEMU_ARCH_ALL)
1355 STEXI
1356 @item -spice @var{option}[,@var{option}[,...]]
1357 @findex -spice
1358 Enable the spice remote desktop protocol. Valid options are
1360 @table @option
1362 @item port=<nr>
1363 Set the TCP port spice is listening on for plaintext channels.
1365 @item addr=<addr>
1366 Set the IP address spice is listening on. Default is any address.
1368 @item ipv4
1369 @itemx ipv6
1370 @itemx unix
1371 Force using the specified IP version.
1373 @item password=<secret>
1374 Set the password you need to authenticate.
1376 @item sasl
1377 Require that the client use SASL to authenticate with the spice.
1378 The exact choice of authentication method used is controlled from the
1379 system / user's SASL configuration file for the 'qemu' service. This
1380 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1381 unprivileged user, an environment variable SASL_CONF_PATH can be used
1382 to make it search alternate locations for the service config.
1383 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1384 it is recommended that SASL always be combined with the 'tls' and
1385 'x509' settings to enable use of SSL and server certificates. This
1386 ensures a data encryption preventing compromise of authentication
1387 credentials.
1389 @item disable-ticketing
1390 Allow client connects without authentication.
1392 @item disable-copy-paste
1393 Disable copy paste between the client and the guest.
1395 @item disable-agent-file-xfer
1396 Disable spice-vdagent based file-xfer between the client and the guest.
1398 @item tls-port=<nr>
1399 Set the TCP port spice is listening on for encrypted channels.
1401 @item x509-dir=<dir>
1402 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1404 @item x509-key-file=<file>
1405 @itemx x509-key-password=<file>
1406 @itemx x509-cert-file=<file>
1407 @itemx x509-cacert-file=<file>
1408 @itemx x509-dh-key-file=<file>
1409 The x509 file names can also be configured individually.
1411 @item tls-ciphers=<list>
1412 Specify which ciphers to use.
1414 @item tls-channel=[main|display|cursor|inputs|record|playback]
1415 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1416 Force specific channel to be used with or without TLS encryption. The
1417 options can be specified multiple times to configure multiple
1418 channels. The special name "default" can be used to set the default
1419 mode. For channels which are not explicitly forced into one mode the
1420 spice client is allowed to pick tls/plaintext as he pleases.
1422 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1423 Configure image compression (lossless).
1424 Default is auto_glz.
1426 @item jpeg-wan-compression=[auto|never|always]
1427 @itemx zlib-glz-wan-compression=[auto|never|always]
1428 Configure wan image compression (lossy for slow links).
1429 Default is auto.
1431 @item streaming-video=[off|all|filter]
1432 Configure video stream detection. Default is off.
1434 @item agent-mouse=[on|off]
1435 Enable/disable passing mouse events via vdagent. Default is on.
1437 @item playback-compression=[on|off]
1438 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1440 @item seamless-migration=[on|off]
1441 Enable/disable spice seamless migration. Default is off.
1443 @item gl=[on|off]
1444 Enable/disable OpenGL context. Default is off.
1446 @item rendernode=<file>
1447 DRM render node for OpenGL rendering. If not specified, it will pick
1448 the first available. (Since 2.9)
1450 @end table
1451 ETEXI
1453 DEF("portrait", 0, QEMU_OPTION_portrait,
1454 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1455 QEMU_ARCH_ALL)
1456 STEXI
1457 @item -portrait
1458 @findex -portrait
1459 Rotate graphical output 90 deg left (only PXA LCD).
1460 ETEXI
1462 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1463 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1464 QEMU_ARCH_ALL)
1465 STEXI
1466 @item -rotate @var{deg}
1467 @findex -rotate
1468 Rotate graphical output some deg left (only PXA LCD).
1469 ETEXI
1471 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1472 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1473 " select video card type\n", QEMU_ARCH_ALL)
1474 STEXI
1475 @item -vga @var{type}
1476 @findex -vga
1477 Select type of VGA card to emulate. Valid values for @var{type} are
1478 @table @option
1479 @item cirrus
1480 Cirrus Logic GD5446 Video card. All Windows versions starting from
1481 Windows 95 should recognize and use this graphic card. For optimal
1482 performances, use 16 bit color depth in the guest and the host OS.
1483 (This card was the default before QEMU 2.2)
1484 @item std
1485 Standard VGA card with Bochs VBE extensions. If your guest OS
1486 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1487 to use high resolution modes (>= 1280x1024x16) then you should use
1488 this option. (This card is the default since QEMU 2.2)
1489 @item vmware
1490 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1491 recent XFree86/XOrg server or Windows guest with a driver for this
1492 card.
1493 @item qxl
1494 QXL paravirtual graphic card. It is VGA compatible (including VESA
1495 2.0 VBE support). Works best with qxl guest drivers installed though.
1496 Recommended choice when using the spice protocol.
1497 @item tcx
1498 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1499 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1500 fixed resolution of 1024x768.
1501 @item cg3
1502 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1503 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1504 resolutions aimed at people wishing to run older Solaris versions.
1505 @item virtio
1506 Virtio VGA card.
1507 @item none
1508 Disable VGA card.
1509 @end table
1510 ETEXI
1512 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1513 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1514 STEXI
1515 @item -full-screen
1516 @findex -full-screen
1517 Start in full screen.
1518 ETEXI
1520 DEF("g", 1, QEMU_OPTION_g ,
1521 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1522 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1523 STEXI
1524 @item -g @var{width}x@var{height}[x@var{depth}]
1525 @findex -g
1526 Set the initial graphical resolution and depth (PPC, SPARC only).
1527 ETEXI
1529 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1530 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1531 STEXI
1532 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1533 @findex -vnc
1534 Normally, if QEMU is compiled with graphical window support, it displays
1535 output such as guest graphics, guest console, and the QEMU monitor in a
1536 window. With this option, you can have QEMU listen on VNC display
1537 @var{display} and redirect the VGA display over the VNC session. It is
1538 very useful to enable the usb tablet device when using this option
1539 (option @option{-device usb-tablet}). When using the VNC display, you
1540 must use the @option{-k} parameter to set the keyboard layout if you are
1541 not using en-us. Valid syntax for the @var{display} is
1543 @table @option
1545 @item to=@var{L}
1547 With this option, QEMU will try next available VNC @var{display}s, until the
1548 number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1549 available, e.g. port 5900+@var{display} is already used by another
1550 application. By default, to=0.
1552 @item @var{host}:@var{d}
1554 TCP connections will only be allowed from @var{host} on display @var{d}.
1555 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1556 be omitted in which case the server will accept connections from any host.
1558 @item unix:@var{path}
1560 Connections will be allowed over UNIX domain sockets where @var{path} is the
1561 location of a unix socket to listen for connections on.
1563 @item none
1565 VNC is initialized but not started. The monitor @code{change} command
1566 can be used to later start the VNC server.
1568 @end table
1570 Following the @var{display} value there may be one or more @var{option} flags
1571 separated by commas. Valid options are
1573 @table @option
1575 @item reverse
1577 Connect to a listening VNC client via a ``reverse'' connection. The
1578 client is specified by the @var{display}. For reverse network
1579 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1580 is a TCP port number, not a display number.
1582 @item websocket
1584 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1585 If a bare @var{websocket} option is given, the Websocket port is
1586 5700+@var{display}. An alternative port can be specified with the
1587 syntax @code{websocket}=@var{port}.
1589 If @var{host} is specified connections will only be allowed from this host.
1590 It is possible to control the websocket listen address independently, using
1591 the syntax @code{websocket}=@var{host}:@var{port}.
1593 If no TLS credentials are provided, the websocket connection runs in
1594 unencrypted mode. If TLS credentials are provided, the websocket connection
1595 requires encrypted client connections.
1597 @item password
1599 Require that password based authentication is used for client connections.
1601 The password must be set separately using the @code{set_password} command in
1602 the @ref{pcsys_monitor}. The syntax to change your password is:
1603 @code{set_password <protocol> <password>} where <protocol> could be either
1604 "vnc" or "spice".
1606 If you would like to change <protocol> password expiration, you should use
1607 @code{expire_password <protocol> <expiration-time>} where expiration time could
1608 be one of the following options: now, never, +seconds or UNIX time of
1609 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1610 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1611 date and time).
1613 You can also use keywords "now" or "never" for the expiration time to
1614 allow <protocol> password to expire immediately or never expire.
1616 @item tls-creds=@var{ID}
1618 Provides the ID of a set of TLS credentials to use to secure the
1619 VNC server. They will apply to both the normal VNC server socket
1620 and the websocket socket (if enabled). Setting TLS credentials
1621 will cause the VNC server socket to enable the VeNCrypt auth
1622 mechanism. The credentials should have been previously created
1623 using the @option{-object tls-creds} argument.
1625 @item sasl
1627 Require that the client use SASL to authenticate with the VNC server.
1628 The exact choice of authentication method used is controlled from the
1629 system / user's SASL configuration file for the 'qemu' service. This
1630 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1631 unprivileged user, an environment variable SASL_CONF_PATH can be used
1632 to make it search alternate locations for the service config.
1633 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1634 it is recommended that SASL always be combined with the 'tls' and
1635 'x509' settings to enable use of SSL and server certificates. This
1636 ensures a data encryption preventing compromise of authentication
1637 credentials. See the @ref{vnc_security} section for details on using
1638 SASL authentication.
1640 @item acl
1642 Turn on access control lists for checking of the x509 client certificate
1643 and SASL party. For x509 certs, the ACL check is made against the
1644 certificate's distinguished name. This is something that looks like
1645 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1646 made against the username, which depending on the SASL plugin, may
1647 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1648 When the @option{acl} flag is set, the initial access list will be
1649 empty, with a @code{deny} policy. Thus no one will be allowed to
1650 use the VNC server until the ACLs have been loaded. This can be
1651 achieved using the @code{acl} monitor command.
1653 @item lossy
1655 Enable lossy compression methods (gradient, JPEG, ...). If this
1656 option is set, VNC client may receive lossy framebuffer updates
1657 depending on its encoding settings. Enabling this option can save
1658 a lot of bandwidth at the expense of quality.
1660 @item non-adaptive
1662 Disable adaptive encodings. Adaptive encodings are enabled by default.
1663 An adaptive encoding will try to detect frequently updated screen regions,
1664 and send updates in these regions using a lossy encoding (like JPEG).
1665 This can be really helpful to save bandwidth when playing videos. Disabling
1666 adaptive encodings restores the original static behavior of encodings
1667 like Tight.
1669 @item share=[allow-exclusive|force-shared|ignore]
1671 Set display sharing policy. 'allow-exclusive' allows clients to ask
1672 for exclusive access. As suggested by the rfb spec this is
1673 implemented by dropping other connections. Connecting multiple
1674 clients in parallel requires all clients asking for a shared session
1675 (vncviewer: -shared switch). This is the default. 'force-shared'
1676 disables exclusive client access. Useful for shared desktop sessions,
1677 where you don't want someone forgetting specify -shared disconnect
1678 everybody else. 'ignore' completely ignores the shared flag and
1679 allows everybody connect unconditionally. Doesn't conform to the rfb
1680 spec but is traditional QEMU behavior.
1682 @item key-delay-ms
1684 Set keyboard delay, for key down and key up events, in milliseconds.
1685 Default is 10. Keyboards are low-bandwidth devices, so this slowdown
1686 can help the device and guest to keep up and not lose events in case
1687 events are arriving in bulk. Possible causes for the latter are flaky
1688 network connections, or scripts for automated testing.
1690 @end table
1691 ETEXI
1693 STEXI
1694 @end table
1695 ETEXI
1696 ARCHHEADING(, QEMU_ARCH_I386)
1698 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1699 STEXI
1700 @table @option
1701 ETEXI
1703 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1704 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1705 QEMU_ARCH_I386)
1706 STEXI
1707 @item -win2k-hack
1708 @findex -win2k-hack
1709 Use it when installing Windows 2000 to avoid a disk full bug. After
1710 Windows 2000 is installed, you no longer need this option (this option
1711 slows down the IDE transfers).
1712 ETEXI
1714 HXCOMM Deprecated by -rtc
1715 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1717 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1718 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1719 QEMU_ARCH_I386)
1720 STEXI
1721 @item -no-fd-bootchk
1722 @findex -no-fd-bootchk
1723 Disable boot signature checking for floppy disks in BIOS. May
1724 be needed to boot from old floppy disks.
1725 ETEXI
1727 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1728 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1729 STEXI
1730 @item -no-acpi
1731 @findex -no-acpi
1732 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1733 it if your guest OS complains about ACPI problems (PC target machine
1734 only).
1735 ETEXI
1737 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1738 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1739 STEXI
1740 @item -no-hpet
1741 @findex -no-hpet
1742 Disable HPET support.
1743 ETEXI
1745 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1746 "-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"
1747 " ACPI table description\n", QEMU_ARCH_I386)
1748 STEXI
1749 @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}]...]
1750 @findex -acpitable
1751 Add ACPI table with specified header fields and context from specified files.
1752 For file=, take whole ACPI table from the specified files, including all
1753 ACPI headers (possible overridden by other options).
1754 For data=, only data
1755 portion of the table is used, all header information is specified in the
1756 command line.
1757 If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1758 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1759 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1760 spec.
1761 ETEXI
1763 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1764 "-smbios file=binary\n"
1765 " load SMBIOS entry from binary file\n"
1766 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1767 " [,uefi=on|off]\n"
1768 " specify SMBIOS type 0 fields\n"
1769 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1770 " [,uuid=uuid][,sku=str][,family=str]\n"
1771 " specify SMBIOS type 1 fields\n"
1772 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1773 " [,asset=str][,location=str]\n"
1774 " specify SMBIOS type 2 fields\n"
1775 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1776 " [,sku=str]\n"
1777 " specify SMBIOS type 3 fields\n"
1778 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1779 " [,asset=str][,part=str]\n"
1780 " specify SMBIOS type 4 fields\n"
1781 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1782 " [,asset=str][,part=str][,speed=%d]\n"
1783 " specify SMBIOS type 17 fields\n",
1784 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1785 STEXI
1786 @item -smbios file=@var{binary}
1787 @findex -smbios
1788 Load SMBIOS entry from binary file.
1790 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1791 Specify SMBIOS type 0 fields
1793 @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}]
1794 Specify SMBIOS type 1 fields
1796 @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}]
1797 Specify SMBIOS type 2 fields
1799 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1800 Specify SMBIOS type 3 fields
1802 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1803 Specify SMBIOS type 4 fields
1805 @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}]
1806 Specify SMBIOS type 17 fields
1807 ETEXI
1809 STEXI
1810 @end table
1811 ETEXI
1812 DEFHEADING()
1814 DEFHEADING(Network options:)
1815 STEXI
1816 @table @option
1817 ETEXI
1819 HXCOMM Legacy slirp options (now moved to -net user):
1820 #ifdef CONFIG_SLIRP
1821 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1822 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1823 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1824 #ifndef _WIN32
1825 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1826 #endif
1827 #endif
1829 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1830 #ifdef CONFIG_SLIRP
1831 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1832 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1833 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1834 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
1835 " [,tftp=dir][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1836 #ifndef _WIN32
1837 "[,smb=dir[,smbserver=addr]]\n"
1838 #endif
1839 " configure a user mode network backend with ID 'str',\n"
1840 " its DHCP server and optional services\n"
1841 #endif
1842 #ifdef _WIN32
1843 "-netdev tap,id=str,ifname=name\n"
1844 " configure a host TAP network backend with ID 'str'\n"
1845 #else
1846 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1847 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1848 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1849 " [,poll-us=n]\n"
1850 " configure a host TAP network backend with ID 'str'\n"
1851 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1852 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1853 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1854 " to deconfigure it\n"
1855 " use '[down]script=no' to disable script execution\n"
1856 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1857 " configure it\n"
1858 " use 'fd=h' to connect to an already opened TAP interface\n"
1859 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1860 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1861 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1862 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1863 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1864 " use vhost=on to enable experimental in kernel accelerator\n"
1865 " (only has effect for virtio guests which use MSIX)\n"
1866 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1867 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
1868 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1869 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1870 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1871 " spent on busy polling for vhost net\n"
1872 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1873 " configure a host TAP network backend with ID 'str' that is\n"
1874 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1875 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1876 #endif
1877 #ifdef __linux__
1878 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1879 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1880 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1881 " [,rxcookie=rxcookie][,offset=offset]\n"
1882 " configure a network backend with ID 'str' connected to\n"
1883 " an Ethernet over L2TPv3 pseudowire.\n"
1884 " Linux kernel 3.3+ as well as most routers can talk\n"
1885 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1886 " VM to a router and even VM to Host. It is a nearly-universal\n"
1887 " standard (RFC3391). Note - this implementation uses static\n"
1888 " pre-configured tunnels (same as the Linux kernel).\n"
1889 " use 'src=' to specify source address\n"
1890 " use 'dst=' to specify destination address\n"
1891 " use 'udp=on' to specify udp encapsulation\n"
1892 " use 'srcport=' to specify source udp port\n"
1893 " use 'dstport=' to specify destination udp port\n"
1894 " use 'ipv6=on' to force v6\n"
1895 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1896 " well as a weak security measure\n"
1897 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
1898 " use 'txcookie=0x012345678' to specify a txcookie\n"
1899 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1900 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1901 " use 'pincounter=on' to work around broken counter handling in peer\n"
1902 " use 'offset=X' to add an extra offset between header and data\n"
1903 #endif
1904 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1905 " configure a network backend to connect to another network\n"
1906 " using a socket connection\n"
1907 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1908 " configure a network backend to connect to a multicast maddr and port\n"
1909 " use 'localaddr=addr' to specify the host address to send packets from\n"
1910 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1911 " configure a network backend to connect to another network\n"
1912 " using an UDP tunnel\n"
1913 #ifdef CONFIG_VDE
1914 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1915 " configure a network backend to connect to port 'n' of a vde switch\n"
1916 " running on host and listening for incoming connections on 'socketpath'.\n"
1917 " Use group 'groupname' and mode 'octalmode' to change default\n"
1918 " ownership and permissions for communication port.\n"
1919 #endif
1920 #ifdef CONFIG_NETMAP
1921 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1922 " attach to the existing netmap-enabled network interface 'name', or to a\n"
1923 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1924 " netmap device, defaults to '/dev/netmap')\n"
1925 #endif
1926 #ifdef CONFIG_POSIX
1927 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1928 " configure a vhost-user network, backed by a chardev 'dev'\n"
1929 #endif
1930 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
1931 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
1932 DEF("nic", HAS_ARG, QEMU_OPTION_nic,
1933 "-nic [tap|bridge|"
1934 #ifdef CONFIG_SLIRP
1935 "user|"
1936 #endif
1937 #ifdef __linux__
1938 "l2tpv3|"
1939 #endif
1940 #ifdef CONFIG_VDE
1941 "vde|"
1942 #endif
1943 #ifdef CONFIG_NETMAP
1944 "netmap|"
1945 #endif
1946 #ifdef CONFIG_POSIX
1947 "vhost-user|"
1948 #endif
1949 "socket][,option][,...][mac=macaddr]\n"
1950 " initialize an on-board / default host NIC (using MAC address\n"
1951 " macaddr) and connect it to the given host network backend\n"
1952 "-nic none use it alone to have zero network devices (the default is to\n"
1953 " provided a 'user' network connection)\n",
1954 QEMU_ARCH_ALL)
1955 DEF("net", HAS_ARG, QEMU_OPTION_net,
1956 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1957 " configure or create an on-board (or machine default) NIC and\n"
1958 " connect it to hub 0 (please use -nic unless you need a hub)\n"
1959 "-net ["
1960 #ifdef CONFIG_SLIRP
1961 "user|"
1962 #endif
1963 "tap|"
1964 "bridge|"
1965 #ifdef CONFIG_VDE
1966 "vde|"
1967 #endif
1968 #ifdef CONFIG_NETMAP
1969 "netmap|"
1970 #endif
1971 "socket][,option][,option][,...]\n"
1972 " old way to initialize a host network interface\n"
1973 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
1974 STEXI
1975 @item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]
1976 @findex -nic
1977 This option is a shortcut for configuring both the on-board (default) guest
1978 NIC hardware and the host network backend in one go. The host backend options
1979 are the same as with the corresponding @option{-netdev} options below.
1980 The guest NIC model can be set with @option{model=@var{modelname}}.
1981 Use @option{model=help} to list the available device types.
1982 The hardware MAC address can be set with @option{mac=@var{macaddr}}.
1984 The following two example do exactly the same, to show how @option{-nic} can
1985 be used to shorten the command line length (note that the e1000 is the default
1986 on i386, so the @option{model=e1000} parameter could even be omitted here, too):
1987 @example
1988 qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
1989 qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
1990 @end example
1992 @item -nic none
1993 Indicate that no network devices should be configured. It is used to override
1994 the default configuration (default NIC with ``user'' host network backend)
1995 which is activated if no other networking options are provided.
1997 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1998 @findex -netdev
1999 Configure user mode host network backend which requires no administrator
2000 privilege to run. Valid options are:
2002 @table @option
2003 @item id=@var{id}
2004 Assign symbolic name for use in monitor commands.
2006 @item ipv4=on|off and ipv6=on|off
2007 Specify that either IPv4 or IPv6 must be enabled. If neither is specified
2008 both protocols are enabled.
2010 @item net=@var{addr}[/@var{mask}]
2011 Set IP network address the guest will see. Optionally specify the netmask,
2012 either in the form a.b.c.d or as number of valid top-most bits. Default is
2013 10.0.2.0/24.
2015 @item host=@var{addr}
2016 Specify the guest-visible address of the host. Default is the 2nd IP in the
2017 guest network, i.e. x.x.x.2.
2019 @item ipv6-net=@var{addr}[/@var{int}]
2020 Set IPv6 network address the guest will see (default is fec0::/64). The
2021 network prefix is given in the usual hexadecimal IPv6 address
2022 notation. The prefix size is optional, and is given as the number of
2023 valid top-most bits (default is 64).
2025 @item ipv6-host=@var{addr}
2026 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2027 the guest network, i.e. xxxx::2.
2029 @item restrict=on|off
2030 If this option is enabled, the guest will be isolated, i.e. it will not be
2031 able to contact the host and no guest IP packets will be routed over the host
2032 to the outside. This option does not affect any explicitly set forwarding rules.
2034 @item hostname=@var{name}
2035 Specifies the client hostname reported by the built-in DHCP server.
2037 @item dhcpstart=@var{addr}
2038 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2039 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2041 @item dns=@var{addr}
2042 Specify the guest-visible address of the virtual nameserver. The address must
2043 be different from the host address. Default is the 3rd IP in the guest network,
2044 i.e. x.x.x.3.
2046 @item ipv6-dns=@var{addr}
2047 Specify the guest-visible address of the IPv6 virtual nameserver. The address
2048 must be different from the host address. Default is the 3rd IP in the guest
2049 network, i.e. xxxx::3.
2051 @item dnssearch=@var{domain}
2052 Provides an entry for the domain-search list sent by the built-in
2053 DHCP server. More than one domain suffix can be transmitted by specifying
2054 this option multiple times. If supported, this will cause the guest to
2055 automatically try to append the given domain suffix(es) in case a domain name
2056 can not be resolved.
2058 Example:
2059 @example
2060 qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2061 @end example
2063 @item domainname=@var{domain}
2064 Specifies the client domain name reported by the built-in DHCP server.
2066 @item tftp=@var{dir}
2067 When using the user mode network stack, activate a built-in TFTP
2068 server. The files in @var{dir} will be exposed as the root of a TFTP server.
2069 The TFTP client on the guest must be configured in binary mode (use the command
2070 @code{bin} of the Unix TFTP client).
2072 @item bootfile=@var{file}
2073 When using the user mode network stack, broadcast @var{file} as the BOOTP
2074 filename. In conjunction with @option{tftp}, this can be used to network boot
2075 a guest from a local directory.
2077 Example (using pxelinux):
2078 @example
2079 qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2080 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2081 @end example
2083 @item smb=@var{dir}[,smbserver=@var{addr}]
2084 When using the user mode network stack, activate a built-in SMB
2085 server so that Windows OSes can access to the host files in @file{@var{dir}}
2086 transparently. The IP address of the SMB server can be set to @var{addr}. By
2087 default the 4th IP in the guest network is used, i.e. x.x.x.4.
2089 In the guest Windows OS, the line:
2090 @example
2091 10.0.2.4 smbserver
2092 @end example
2093 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2094 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2096 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2098 Note that a SAMBA server must be installed on the host OS.
2100 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2101 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2102 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2103 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2104 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2105 be bound to a specific host interface. If no connection type is set, TCP is
2106 used. This option can be given multiple times.
2108 For example, to redirect host X11 connection from screen 1 to guest
2109 screen 0, use the following:
2111 @example
2112 # on the host
2113 qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2114 # this host xterm should open in the guest X11 server
2115 xterm -display :1
2116 @end example
2118 To redirect telnet connections from host port 5555 to telnet port on
2119 the guest, use the following:
2121 @example
2122 # on the host
2123 qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2124 telnet localhost 5555
2125 @end example
2127 Then when you use on the host @code{telnet localhost 5555}, you
2128 connect to the guest telnet server.
2130 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2131 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2132 Forward guest TCP connections to the IP address @var{server} on port @var{port}
2133 to the character device @var{dev} or to a program executed by @var{cmd:command}
2134 which gets spawned for each connection. This option can be given multiple times.
2136 You can either use a chardev directly and have that one used throughout QEMU's
2137 lifetime, like in the following example:
2139 @example
2140 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2141 # the guest accesses it
2142 qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
2143 @end example
2145 Or you can execute a command on every TCP connection established by the guest,
2146 so that QEMU behaves similar to an inetd process for that virtual server:
2148 @example
2149 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2150 # and connect the TCP stream to its stdin/stdout
2151 qemu-system-i386 -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2152 @end example
2154 @end table
2156 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2157 processed and applied to -net user. Mixing them with the new configuration
2158 syntax gives undefined results. Their use for new applications is discouraged
2159 as they will be removed from future versions.
2161 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2162 Configure a host TAP network backend with ID @var{id}.
2164 Use the network script @var{file} to configure it and the network script
2165 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2166 automatically provides one. The default network configure script is
2167 @file{/etc/qemu-ifup} and the default network deconfigure script is
2168 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2169 to disable script execution.
2171 If running QEMU as an unprivileged user, use the network helper
2172 @var{helper} to configure the TAP interface and attach it to the bridge.
2173 The default network helper executable is @file{/path/to/qemu-bridge-helper}
2174 and the default bridge device is @file{br0}.
2176 @option{fd}=@var{h} can be used to specify the handle of an already
2177 opened host TAP interface.
2179 Examples:
2181 @example
2182 #launch a QEMU instance with the default network script
2183 qemu-system-i386 linux.img -nic tap
2184 @end example
2186 @example
2187 #launch a QEMU instance with two NICs, each one connected
2188 #to a TAP device
2189 qemu-system-i386 linux.img \
2190 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2191 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2192 @end example
2194 @example
2195 #launch a QEMU instance with the default network helper to
2196 #connect a TAP device to bridge br0
2197 qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \
2198 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
2199 @end example
2201 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2202 Connect a host TAP network interface to a host bridge device.
2204 Use the network helper @var{helper} to configure the TAP interface and
2205 attach it to the bridge. The default network helper executable is
2206 @file{/path/to/qemu-bridge-helper} and the default bridge
2207 device is @file{br0}.
2209 Examples:
2211 @example
2212 #launch a QEMU instance with the default network helper to
2213 #connect a TAP device to bridge br0
2214 qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
2215 @end example
2217 @example
2218 #launch a QEMU instance with the default network helper to
2219 #connect a TAP device to bridge qemubr0
2220 qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
2221 @end example
2223 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2225 This host network backend can be used to connect the guest's network to
2226 another QEMU virtual machine using a TCP socket connection. If @option{listen}
2227 is specified, QEMU waits for incoming connections on @var{port}
2228 (@var{host} is optional). @option{connect} is used to connect to
2229 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2230 specifies an already opened TCP socket.
2232 Example:
2233 @example
2234 # launch a first QEMU instance
2235 qemu-system-i386 linux.img \
2236 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2237 -netdev socket,id=n1,listen=:1234
2238 # connect the network of this instance to the network of the first instance
2239 qemu-system-i386 linux.img \
2240 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2241 -netdev socket,id=n2,connect=127.0.0.1:1234
2242 @end example
2244 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2246 Configure a socket host network backend to share the guest's network traffic
2247 with another QEMU virtual machines using a UDP multicast socket, effectively
2248 making a bus for every QEMU with same multicast address @var{maddr} and @var{port}.
2249 NOTES:
2250 @enumerate
2251 @item
2252 Several QEMU can be running on different hosts and share same bus (assuming
2253 correct multicast setup for these hosts).
2254 @item
2255 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2256 @url{http://user-mode-linux.sf.net}.
2257 @item
2258 Use @option{fd=h} to specify an already opened UDP multicast socket.
2259 @end enumerate
2261 Example:
2262 @example
2263 # launch one QEMU instance
2264 qemu-system-i386 linux.img \
2265 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2266 -netdev socket,id=n1,mcast=230.0.0.1:1234
2267 # launch another QEMU instance on same "bus"
2268 qemu-system-i386 linux.img \
2269 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2270 -netdev socket,id=n2,mcast=230.0.0.1:1234
2271 # launch yet another QEMU instance on same "bus"
2272 qemu-system-i386 linux.img \
2273 -device e1000,netdev=n3,macaddr=52:54:00:12:34:58 \
2274 -netdev socket,id=n3,mcast=230.0.0.1:1234
2275 @end example
2277 Example (User Mode Linux compat.):
2278 @example
2279 # launch QEMU instance (note mcast address selected is UML's default)
2280 qemu-system-i386 linux.img \
2281 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2282 -netdev socket,id=n1,mcast=239.192.168.1:1102
2283 # launch UML
2284 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2285 @end example
2287 Example (send packets from host's 1.2.3.4):
2288 @example
2289 qemu-system-i386 linux.img \
2290 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2291 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2292 @end example
2294 @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}]
2295 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a
2296 popular protocol to transport Ethernet (and other Layer 2) data frames between
2297 two systems. It is present in routers, firewalls and the Linux kernel
2298 (from version 3.3 onwards).
2300 This transport allows a VM to communicate to another VM, router or firewall directly.
2302 @table @option
2303 @item src=@var{srcaddr}
2304 source address (mandatory)
2305 @item dst=@var{dstaddr}
2306 destination address (mandatory)
2307 @item udp
2308 select udp encapsulation (default is ip).
2309 @item srcport=@var{srcport}
2310 source udp port.
2311 @item dstport=@var{dstport}
2312 destination udp port.
2313 @item ipv6
2314 force v6, otherwise defaults to v4.
2315 @item rxcookie=@var{rxcookie}
2316 @itemx txcookie=@var{txcookie}
2317 Cookies are a weak form of security in the l2tpv3 specification.
2318 Their function is mostly to prevent misconfiguration. By default they are 32
2319 bit.
2320 @item cookie64
2321 Set cookie size to 64 bit instead of the default 32
2322 @item counter=off
2323 Force a 'cut-down' L2TPv3 with no counter as in
2324 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2325 @item pincounter=on
2326 Work around broken counter handling in peer. This may also help on
2327 networks which have packet reorder.
2328 @item offset=@var{offset}
2329 Add an extra offset between header and data
2330 @end table
2332 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2333 on the remote Linux host 1.2.3.4:
2334 @example
2335 # Setup tunnel on linux host using raw ip as encapsulation
2336 # on 1.2.3.4
2337 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2338 encap udp udp_sport 16384 udp_dport 16384
2339 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2340 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2341 ifconfig vmtunnel0 mtu 1500
2342 ifconfig vmtunnel0 up
2343 brctl addif br-lan vmtunnel0
2346 # on 4.3.2.1
2347 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2349 qemu-system-i386 linux.img -device e1000,netdev=n1 \
2350 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2352 @end example
2354 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2355 Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and
2356 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2357 and MODE @var{octalmode} to change default ownership and permissions for
2358 communication port. This option is only available if QEMU has been compiled
2359 with vde support enabled.
2361 Example:
2362 @example
2363 # launch vde switch
2364 vde_switch -F -sock /tmp/myswitch
2365 # launch QEMU instance
2366 qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch
2367 @end example
2369 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2371 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2372 be a unix domain socket backed one. The vhost-user uses a specifically defined
2373 protocol to pass vhost ioctl replacement messages to an application on the other
2374 end of the socket. On non-MSIX guests, the feature can be forced with
2375 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2376 be created for multiqueue vhost-user.
2378 Example:
2379 @example
2380 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2381 -numa node,memdev=mem \
2382 -chardev socket,id=chr0,path=/path/to/socket \
2383 -netdev type=vhost-user,id=net0,chardev=chr0 \
2384 -device virtio-net-pci,netdev=net0
2385 @end example
2387 @item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2389 Create a hub port on the emulated hub with ID @var{hubid}.
2391 The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2392 single netdev. Alternatively, you can also connect the hubport to another
2393 netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option.
2395 @item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2396 @findex -net
2397 Legacy option to configure or create an on-board (or machine default) Network
2398 Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e.
2399 the default hub), or to the netdev @var{nd}.
2400 The NIC is an e1000 by default on the PC target. Optionally, the MAC address
2401 can be changed to @var{mac}, the device address set to @var{addr} (PCI cards
2402 only), and a @var{name} can be assigned for use in monitor commands.
2403 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2404 that the card should have; this option currently only affects virtio cards; set
2405 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2406 NIC is created. QEMU can emulate several different models of network card.
2407 Use @code{-net nic,model=help} for a list of available devices for your target.
2409 @item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}]
2410 Configure a host network backend (with the options corresponding to the same
2411 @option{-netdev} option) and connect it to the emulated hub 0 (the default
2412 hub). Use @var{name} to specify the name of the hub port.
2413 ETEXI
2415 STEXI
2416 @end table
2417 ETEXI
2418 DEFHEADING()
2420 DEFHEADING(Character device options:)
2422 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2423 "-chardev help\n"
2424 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2425 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2426 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2427 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2428 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2429 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2430 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2431 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2432 " [,logfile=PATH][,logappend=on|off]\n"
2433 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2434 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2435 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2436 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2437 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2438 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2439 #ifdef _WIN32
2440 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2441 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2442 #else
2443 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2444 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2445 #endif
2446 #ifdef CONFIG_BRLAPI
2447 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2448 #endif
2449 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2450 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2451 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2452 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2453 #endif
2454 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2455 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2456 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2457 #endif
2458 #if defined(CONFIG_SPICE)
2459 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2460 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2461 #endif
2462 , QEMU_ARCH_ALL
2465 STEXI
2467 The general form of a character device option is:
2468 @table @option
2469 @item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2470 @findex -chardev
2471 Backend is one of:
2472 @option{null},
2473 @option{socket},
2474 @option{udp},
2475 @option{msmouse},
2476 @option{vc},
2477 @option{ringbuf},
2478 @option{file},
2479 @option{pipe},
2480 @option{console},
2481 @option{serial},
2482 @option{pty},
2483 @option{stdio},
2484 @option{braille},
2485 @option{tty},
2486 @option{parallel},
2487 @option{parport},
2488 @option{spicevmc},
2489 @option{spiceport}.
2490 The specific backend will determine the applicable options.
2492 Use @code{-chardev help} to print all available chardev backend types.
2494 All devices must have an id, which can be any string up to 127 characters long.
2495 It is used to uniquely identify this device in other command line directives.
2497 A character device may be used in multiplexing mode by multiple front-ends.
2498 Specify @option{mux=on} to enable this mode.
2499 A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2500 backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2501 If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2502 create a multiplexer with your specified ID, and you can then configure multiple
2503 front ends to use that chardev ID for their input/output. Up to four different
2504 front ends can be connected to a single multiplexed chardev. (Without
2505 multiplexing enabled, a chardev can only be used by a single front end.)
2506 For instance you could use this to allow a single stdio chardev to be used by
2507 two serial ports and the QEMU monitor:
2509 @example
2510 -chardev stdio,mux=on,id=char0 \
2511 -mon chardev=char0,mode=readline \
2512 -serial chardev:char0 \
2513 -serial chardev:char0
2514 @end example
2516 You can have more than one multiplexer in a system configuration; for instance
2517 you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2518 multiplexed between the QEMU monitor and a parallel port:
2520 @example
2521 -chardev stdio,mux=on,id=char0 \
2522 -mon chardev=char0,mode=readline \
2523 -parallel chardev:char0 \
2524 -chardev tcp,...,mux=on,id=char1 \
2525 -serial chardev:char1 \
2526 -serial chardev:char1
2527 @end example
2529 When you're using a multiplexed character device, some escape sequences are
2530 interpreted in the input. @xref{mux_keys, Keys in the character backend
2531 multiplexer}.
2533 Note that some other command line options may implicitly create multiplexed
2534 character backends; for instance @option{-serial mon:stdio} creates a
2535 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2536 and @option{-nographic} also multiplexes the console and the monitor to
2537 stdio.
2539 There is currently no support for multiplexing in the other direction
2540 (where a single QEMU front end takes input and output from multiple chardevs).
2542 Every backend supports the @option{logfile} option, which supplies the path
2543 to a file to record all data transmitted via the backend. The @option{logappend}
2544 option controls whether the log file will be truncated or appended to when
2545 opened.
2547 @end table
2549 The available backends are:
2551 @table @option
2552 @item -chardev null,id=@var{id}
2553 A void device. This device will not emit any data, and will drop any data it
2554 receives. The null backend does not take any options.
2556 @item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2558 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2559 unix socket will be created if @option{path} is specified. Behaviour is
2560 undefined if TCP options are specified for a unix socket.
2562 @option{server} specifies that the socket shall be a listening socket.
2564 @option{nowait} specifies that QEMU should not block waiting for a client to
2565 connect to a listening socket.
2567 @option{telnet} specifies that traffic on the socket should interpret telnet
2568 escape sequences.
2570 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2571 the remote end goes away. qemu will delay this many seconds and then attempt
2572 to reconnect. Zero disables reconnecting, and is the default.
2574 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2575 and specifies the id of the TLS credentials to use for the handshake. The
2576 credentials must be previously created with the @option{-object tls-creds}
2577 argument.
2579 TCP and unix socket options are given below:
2581 @table @option
2583 @item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2585 @option{host} for a listening socket specifies the local address to be bound.
2586 For a connecting socket species the remote host to connect to. @option{host} is
2587 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2589 @option{port} for a listening socket specifies the local port to be bound. For a
2590 connecting socket specifies the port on the remote host to connect to.
2591 @option{port} can be given as either a port number or a service name.
2592 @option{port} is required.
2594 @option{to} is only relevant to listening sockets. If it is specified, and
2595 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2596 to and including @option{to} until it succeeds. @option{to} must be specified
2597 as a port number.
2599 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2600 If neither is specified the socket may use either protocol.
2602 @option{nodelay} disables the Nagle algorithm.
2604 @item unix options: path=@var{path}
2606 @option{path} specifies the local path of the unix socket. @option{path} is
2607 required.
2609 @end table
2611 @item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2613 Sends all traffic from the guest to a remote host over UDP.
2615 @option{host} specifies the remote host to connect to. If not specified it
2616 defaults to @code{localhost}.
2618 @option{port} specifies the port on the remote host to connect to. @option{port}
2619 is required.
2621 @option{localaddr} specifies the local address to bind to. If not specified it
2622 defaults to @code{0.0.0.0}.
2624 @option{localport} specifies the local port to bind to. If not specified any
2625 available local port will be used.
2627 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2628 If neither is specified the device may use either protocol.
2630 @item -chardev msmouse,id=@var{id}
2632 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2633 take any options.
2635 @item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2637 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2638 size.
2640 @option{width} and @option{height} specify the width and height respectively of
2641 the console, in pixels.
2643 @option{cols} and @option{rows} specify that the console be sized to fit a text
2644 console with the given dimensions.
2646 @item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2648 Create a ring buffer with fixed size @option{size}.
2649 @var{size} must be a power of two and defaults to @code{64K}.
2651 @item -chardev file,id=@var{id},path=@var{path}
2653 Log all traffic received from the guest to a file.
2655 @option{path} specifies the path of the file to be opened. This file will be
2656 created if it does not already exist, and overwritten if it does. @option{path}
2657 is required.
2659 @item -chardev pipe,id=@var{id},path=@var{path}
2661 Create a two-way connection to the guest. The behaviour differs slightly between
2662 Windows hosts and other hosts:
2664 On Windows, a single duplex pipe will be created at
2665 @file{\\.pipe\@option{path}}.
2667 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2668 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2669 received by the guest. Data written by the guest can be read from
2670 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2671 be present.
2673 @option{path} forms part of the pipe path as described above. @option{path} is
2674 required.
2676 @item -chardev console,id=@var{id}
2678 Send traffic from the guest to QEMU's standard output. @option{console} does not
2679 take any options.
2681 @option{console} is only available on Windows hosts.
2683 @item -chardev serial,id=@var{id},path=@option{path}
2685 Send traffic from the guest to a serial device on the host.
2687 On Unix hosts serial will actually accept any tty device,
2688 not only serial lines.
2690 @option{path} specifies the name of the serial device to open.
2692 @item -chardev pty,id=@var{id}
2694 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2695 not take any options.
2697 @option{pty} is not available on Windows hosts.
2699 @item -chardev stdio,id=@var{id}[,signal=on|off]
2700 Connect to standard input and standard output of the QEMU process.
2702 @option{signal} controls if signals are enabled on the terminal, that includes
2703 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2704 default, use @option{signal=off} to disable it.
2706 @item -chardev braille,id=@var{id}
2708 Connect to a local BrlAPI server. @option{braille} does not take any options.
2710 @item -chardev tty,id=@var{id},path=@var{path}
2712 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2713 DragonFlyBSD hosts. It is an alias for @option{serial}.
2715 @option{path} specifies the path to the tty. @option{path} is required.
2717 @item -chardev parallel,id=@var{id},path=@var{path}
2718 @itemx -chardev parport,id=@var{id},path=@var{path}
2720 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2722 Connect to a local parallel port.
2724 @option{path} specifies the path to the parallel port device. @option{path} is
2725 required.
2727 @item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2729 @option{spicevmc} is only available when spice support is built in.
2731 @option{debug} debug level for spicevmc
2733 @option{name} name of spice channel to connect to
2735 Connect to a spice virtual machine channel, such as vdiport.
2737 @item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2739 @option{spiceport} is only available when spice support is built in.
2741 @option{debug} debug level for spicevmc
2743 @option{name} name of spice port to connect to
2745 Connect to a spice port, allowing a Spice client to handle the traffic
2746 identified by a name (preferably a fqdn).
2747 ETEXI
2749 STEXI
2750 @end table
2751 ETEXI
2752 DEFHEADING()
2754 DEFHEADING(Bluetooth(R) options:)
2755 STEXI
2756 @table @option
2757 ETEXI
2759 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2760 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2761 "-bt hci,host[:id]\n" \
2762 " use host's HCI with the given name\n" \
2763 "-bt hci[,vlan=n]\n" \
2764 " emulate a standard HCI in virtual scatternet 'n'\n" \
2765 "-bt vhci[,vlan=n]\n" \
2766 " add host computer to virtual scatternet 'n' using VHCI\n" \
2767 "-bt device:dev[,vlan=n]\n" \
2768 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2769 QEMU_ARCH_ALL)
2770 STEXI
2771 @item -bt hci[...]
2772 @findex -bt
2773 Defines the function of the corresponding Bluetooth HCI. -bt options
2774 are matched with the HCIs present in the chosen machine type. For
2775 example when emulating a machine with only one HCI built into it, only
2776 the first @code{-bt hci[...]} option is valid and defines the HCI's
2777 logic. The Transport Layer is decided by the machine type. Currently
2778 the machines @code{n800} and @code{n810} have one HCI and all other
2779 machines have none.
2781 @anchor{bt-hcis}
2782 The following three types are recognized:
2784 @table @option
2785 @item -bt hci,null
2786 (default) The corresponding Bluetooth HCI assumes no internal logic
2787 and will not respond to any HCI commands or emit events.
2789 @item -bt hci,host[:@var{id}]
2790 (@code{bluez} only) The corresponding HCI passes commands / events
2791 to / from the physical HCI identified by the name @var{id} (default:
2792 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2793 capable systems like Linux.
2795 @item -bt hci[,vlan=@var{n}]
2796 Add a virtual, standard HCI that will participate in the Bluetooth
2797 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2798 VLANs, devices inside a bluetooth network @var{n} can only communicate
2799 with other devices in the same network (scatternet).
2800 @end table
2802 @item -bt vhci[,vlan=@var{n}]
2803 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2804 to the host bluetooth stack instead of to the emulated target. This
2805 allows the host and target machines to participate in a common scatternet
2806 and communicate. Requires the Linux @code{vhci} driver installed. Can
2807 be used as following:
2809 @example
2810 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2811 @end example
2813 @item -bt device:@var{dev}[,vlan=@var{n}]
2814 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2815 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2816 currently:
2818 @table @option
2819 @item keyboard
2820 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2821 @end table
2822 ETEXI
2824 STEXI
2825 @end table
2826 ETEXI
2827 DEFHEADING()
2829 #ifdef CONFIG_TPM
2830 DEFHEADING(TPM device options:)
2832 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2833 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2834 " use path to provide path to a character device; default is /dev/tpm0\n"
2835 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2836 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2837 "-tpmdev emulator,id=id,chardev=dev\n"
2838 " configure the TPM device using chardev backend\n",
2839 QEMU_ARCH_ALL)
2840 STEXI
2842 The general form of a TPM device option is:
2843 @table @option
2845 @item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2846 @findex -tpmdev
2848 The specific backend type will determine the applicable options.
2849 The @code{-tpmdev} option creates the TPM backend and requires a
2850 @code{-device} option that specifies the TPM frontend interface model.
2852 Use @code{-tpmdev help} to print all available TPM backend types.
2854 @end table
2856 The available backends are:
2858 @table @option
2860 @item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2862 (Linux-host only) Enable access to the host's TPM using the passthrough
2863 driver.
2865 @option{path} specifies the path to the host's TPM device, i.e., on
2866 a Linux host this would be @code{/dev/tpm0}.
2867 @option{path} is optional and by default @code{/dev/tpm0} is used.
2869 @option{cancel-path} specifies the path to the host TPM device's sysfs
2870 entry allowing for cancellation of an ongoing TPM command.
2871 @option{cancel-path} is optional and by default QEMU will search for the
2872 sysfs entry to use.
2874 Some notes about using the host's TPM with the passthrough driver:
2876 The TPM device accessed by the passthrough driver must not be
2877 used by any other application on the host.
2879 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2880 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2881 TPM again and may therefore not show a TPM-specific menu that would
2882 otherwise allow the user to configure the TPM, e.g., allow the user to
2883 enable/disable or activate/deactivate the TPM.
2884 Further, if TPM ownership is released from within a VM then the host's TPM
2885 will get disabled and deactivated. To enable and activate the
2886 TPM again afterwards, the host has to be rebooted and the user is
2887 required to enter the firmware's menu to enable and activate the TPM.
2888 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2890 To create a passthrough TPM use the following two options:
2891 @example
2892 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2893 @end example
2894 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2895 @code{tpmdev=tpm0} in the device option.
2897 @item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2899 (Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2900 chardev backend.
2902 @option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2904 To create a TPM emulator backend device with chardev socket backend:
2905 @example
2907 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2909 @end example
2911 ETEXI
2913 STEXI
2914 @end table
2915 ETEXI
2916 DEFHEADING()
2918 #endif
2920 DEFHEADING(Linux/Multiboot boot specific:)
2921 STEXI
2923 When using these options, you can use a given Linux or Multiboot
2924 kernel without installing it in the disk image. It can be useful
2925 for easier testing of various kernels.
2927 @table @option
2928 ETEXI
2930 DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
2931 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
2932 STEXI
2933 @item -kernel @var{bzImage}
2934 @findex -kernel
2935 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2936 or in multiboot format.
2937 ETEXI
2939 DEF("append", HAS_ARG, QEMU_OPTION_append, \
2940 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
2941 STEXI
2942 @item -append @var{cmdline}
2943 @findex -append
2944 Use @var{cmdline} as kernel command line
2945 ETEXI
2947 DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
2948 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
2949 STEXI
2950 @item -initrd @var{file}
2951 @findex -initrd
2952 Use @var{file} as initial ram disk.
2954 @item -initrd "@var{file1} arg=foo,@var{file2}"
2956 This syntax is only available with multiboot.
2958 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2959 first module.
2960 ETEXI
2962 DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
2963 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
2964 STEXI
2965 @item -dtb @var{file}
2966 @findex -dtb
2967 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2968 on boot.
2969 ETEXI
2971 STEXI
2972 @end table
2973 ETEXI
2974 DEFHEADING()
2976 DEFHEADING(Debug/Expert options:)
2977 STEXI
2978 @table @option
2979 ETEXI
2981 DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
2982 "-fw_cfg [name=]<name>,file=<file>\n"
2983 " add named fw_cfg entry with contents from file\n"
2984 "-fw_cfg [name=]<name>,string=<str>\n"
2985 " add named fw_cfg entry with contents from string\n",
2986 QEMU_ARCH_ALL)
2987 STEXI
2989 @item -fw_cfg [name=]@var{name},file=@var{file}
2990 @findex -fw_cfg
2991 Add named fw_cfg entry with contents from file @var{file}.
2993 @item -fw_cfg [name=]@var{name},string=@var{str}
2994 Add named fw_cfg entry with contents from string @var{str}.
2996 The terminating NUL character of the contents of @var{str} will not be
2997 included as part of the fw_cfg item data. To insert contents with
2998 embedded NUL characters, you have to use the @var{file} parameter.
3000 The fw_cfg entries are passed by QEMU through to the guest.
3002 Example:
3003 @example
3004 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3005 @end example
3006 creates an fw_cfg entry named opt/com.mycompany/blob with contents
3007 from ./my_blob.bin.
3009 ETEXI
3011 DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3012 "-serial dev redirect the serial port to char device 'dev'\n",
3013 QEMU_ARCH_ALL)
3014 STEXI
3015 @item -serial @var{dev}
3016 @findex -serial
3017 Redirect the virtual serial port to host character device
3018 @var{dev}. The default device is @code{vc} in graphical mode and
3019 @code{stdio} in non graphical mode.
3021 This option can be used several times to simulate up to 4 serial
3022 ports.
3024 Use @code{-serial none} to disable all serial ports.
3026 Available character devices are:
3027 @table @option
3028 @item vc[:@var{W}x@var{H}]
3029 Virtual console. Optionally, a width and height can be given in pixel with
3030 @example
3031 vc:800x600
3032 @end example
3033 It is also possible to specify width or height in characters:
3034 @example
3035 vc:80Cx24C
3036 @end example
3037 @item pty
3038 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3039 @item none
3040 No device is allocated.
3041 @item null
3042 void device
3043 @item chardev:@var{id}
3044 Use a named character device defined with the @code{-chardev} option.
3045 @item /dev/XXX
3046 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3047 parameters are set according to the emulated ones.
3048 @item /dev/parport@var{N}
3049 [Linux only, parallel port only] Use host parallel port
3050 @var{N}. Currently SPP and EPP parallel port features can be used.
3051 @item file:@var{filename}
3052 Write output to @var{filename}. No character can be read.
3053 @item stdio
3054 [Unix only] standard input/output
3055 @item pipe:@var{filename}
3056 name pipe @var{filename}
3057 @item COM@var{n}
3058 [Windows only] Use host serial port @var{n}
3059 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3060 This implements UDP Net Console.
3061 When @var{remote_host} or @var{src_ip} are not specified
3062 they default to @code{0.0.0.0}.
3063 When not using a specified @var{src_port} a random port is automatically chosen.
3065 If you just want a simple readonly console you can use @code{netcat} or
3066 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3067 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3068 will appear in the netconsole session.
3070 If you plan to send characters back via netconsole or you want to stop
3071 and start QEMU a lot of times, you should have QEMU use the same
3072 source port each time by using something like @code{-serial
3073 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3074 version of netcat which can listen to a TCP port and send and receive
3075 characters via udp. If you have a patched version of netcat which
3076 activates telnet remote echo and single char transfer, then you can
3077 use the following options to set up a netcat redirector to allow
3078 telnet on port 5555 to access the QEMU port.
3079 @table @code
3080 @item QEMU Options:
3081 -serial udp::4555@@:4556
3082 @item netcat options:
3083 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3084 @item telnet options:
3085 localhost 5555
3086 @end table
3088 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3089 The TCP Net Console has two modes of operation. It can send the serial
3090 I/O to a location or wait for a connection from a location. By default
3091 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3092 the @var{server} option QEMU will wait for a client socket application
3093 to connect to the port before continuing, unless the @code{nowait}
3094 option was specified. The @code{nodelay} option disables the Nagle buffering
3095 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3096 set, if the connection goes down it will attempt to reconnect at the
3097 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3098 one TCP connection at a time is accepted. You can use @code{telnet} to
3099 connect to the corresponding character device.
3100 @table @code
3101 @item Example to send tcp console to 192.168.0.2 port 4444
3102 -serial tcp:192.168.0.2:4444
3103 @item Example to listen and wait on port 4444 for connection
3104 -serial tcp::4444,server
3105 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3106 -serial tcp:192.168.0.100:4444,server,nowait
3107 @end table
3109 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3110 The telnet protocol is used instead of raw tcp sockets. The options
3111 work the same as if you had specified @code{-serial tcp}. The
3112 difference is that the port acts like a telnet server or client using
3113 telnet option negotiation. This will also allow you to send the
3114 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3115 sequence. Typically in unix telnet you do it with Control-] and then
3116 type "send break" followed by pressing the enter key.
3118 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3119 A unix domain socket is used instead of a tcp socket. The option works the
3120 same as if you had specified @code{-serial tcp} except the unix domain socket
3121 @var{path} is used for connections.
3123 @item mon:@var{dev_string}
3124 This is a special option to allow the monitor to be multiplexed onto
3125 another serial port. The monitor is accessed with key sequence of
3126 @key{Control-a} and then pressing @key{c}.
3127 @var{dev_string} should be any one of the serial devices specified
3128 above. An example to multiplex the monitor onto a telnet server
3129 listening on port 4444 would be:
3130 @table @code
3131 @item -serial mon:telnet::4444,server,nowait
3132 @end table
3133 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3134 QEMU any more but will be passed to the guest instead.
3136 @item braille
3137 Braille device. This will use BrlAPI to display the braille output on a real
3138 or fake device.
3140 @item msmouse
3141 Three button serial mouse. Configure the guest to use Microsoft protocol.
3142 @end table
3143 ETEXI
3145 DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3146 "-parallel dev redirect the parallel port to char device 'dev'\n",
3147 QEMU_ARCH_ALL)
3148 STEXI
3149 @item -parallel @var{dev}
3150 @findex -parallel
3151 Redirect the virtual parallel port to host device @var{dev} (same
3152 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3153 be used to use hardware devices connected on the corresponding host
3154 parallel port.
3156 This option can be used several times to simulate up to 3 parallel
3157 ports.
3159 Use @code{-parallel none} to disable all parallel ports.
3160 ETEXI
3162 DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3163 "-monitor dev redirect the monitor to char device 'dev'\n",
3164 QEMU_ARCH_ALL)
3165 STEXI
3166 @item -monitor @var{dev}
3167 @findex -monitor
3168 Redirect the monitor to host device @var{dev} (same devices as the
3169 serial port).
3170 The default device is @code{vc} in graphical mode and @code{stdio} in
3171 non graphical mode.
3172 Use @code{-monitor none} to disable the default monitor.
3173 ETEXI
3174 DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3175 "-qmp dev like -monitor but opens in 'control' mode\n",
3176 QEMU_ARCH_ALL)
3177 STEXI
3178 @item -qmp @var{dev}
3179 @findex -qmp
3180 Like -monitor but opens in 'control' mode.
3181 ETEXI
3182 DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3183 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3184 QEMU_ARCH_ALL)
3185 STEXI
3186 @item -qmp-pretty @var{dev}
3187 @findex -qmp-pretty
3188 Like -qmp but uses pretty JSON formatting.
3189 ETEXI
3191 DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3192 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3193 STEXI
3194 @item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3195 @findex -mon
3196 Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3197 easing human reading and debugging.
3198 ETEXI
3200 DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3201 "-debugcon dev redirect the debug console to char device 'dev'\n",
3202 QEMU_ARCH_ALL)
3203 STEXI
3204 @item -debugcon @var{dev}
3205 @findex -debugcon
3206 Redirect the debug console to host device @var{dev} (same devices as the
3207 serial port). The debug console is an I/O port which is typically port
3208 0xe9; writing to that I/O port sends output to this device.
3209 The default device is @code{vc} in graphical mode and @code{stdio} in
3210 non graphical mode.
3211 ETEXI
3213 DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3214 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
3215 STEXI
3216 @item -pidfile @var{file}
3217 @findex -pidfile
3218 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3219 from a script.
3220 ETEXI
3222 DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3223 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
3224 STEXI
3225 @item -singlestep
3226 @findex -singlestep
3227 Run the emulation in single step mode.
3228 ETEXI
3230 DEF("preconfig", 0, QEMU_OPTION_preconfig, \
3231 "--preconfig pause QEMU before machine is initialized (experimental)\n",
3232 QEMU_ARCH_ALL)
3233 STEXI
3234 @item --preconfig
3235 @findex --preconfig
3236 Pause QEMU for interactive configuration before the machine is created,
3237 which allows querying and configuring properties that will affect
3238 machine initialization. Use QMP command 'x-exit-preconfig' to exit
3239 the preconfig state and move to the next state (i.e. run guest if -S
3240 isn't used or pause the second time if -S is used). This option is
3241 experimental.
3242 ETEXI
3244 DEF("S", 0, QEMU_OPTION_S, \
3245 "-S freeze CPU at startup (use 'c' to start execution)\n",
3246 QEMU_ARCH_ALL)
3247 STEXI
3248 @item -S
3249 @findex -S
3250 Do not start CPU at startup (you must type 'c' in the monitor).
3251 ETEXI
3253 DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3254 "-realtime [mlock=on|off]\n"
3255 " run qemu with realtime features\n"
3256 " mlock=on|off controls mlock support (default: on)\n",
3257 QEMU_ARCH_ALL)
3258 STEXI
3259 @item -realtime mlock=on|off
3260 @findex -realtime
3261 Run qemu with realtime features.
3262 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3263 (enabled by default).
3264 ETEXI
3266 DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit,
3267 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n"
3268 " run qemu with overcommit hints\n"
3269 " mem-lock=on|off controls memory lock support (default: off)\n"
3270 " cpu-pm=on|off controls cpu power management (default: off)\n",
3271 QEMU_ARCH_ALL)
3272 STEXI
3273 @item -overcommit mem-lock=on|off
3274 @item -overcommit cpu-pm=on|off
3275 @findex -overcommit
3276 Run qemu with hints about host resource overcommit. The default is
3277 to assume that host overcommits all resources.
3279 Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled
3280 by default). This works when host memory is not overcommitted and reduces the
3281 worst-case latency for guest. This is equivalent to @option{realtime}.
3283 Guest ability to manage power state of host cpus (increasing latency for other
3284 processes on the same host cpu, but decreasing latency for guest) can be
3285 enabled via @option{cpu-pm=on} (disabled by default). This works best when
3286 host CPU is not overcommitted. When used, host estimates of CPU cycle and power
3287 utilization will be incorrect, not taking into account guest idle time.
3288 ETEXI
3290 DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3291 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3292 STEXI
3293 @item -gdb @var{dev}
3294 @findex -gdb
3295 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3296 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3297 stdio are reasonable use case. The latter is allowing to start QEMU from
3298 within gdb and establish the connection via a pipe:
3299 @example
3300 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3301 @end example
3302 ETEXI
3304 DEF("s", 0, QEMU_OPTION_s, \
3305 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3306 QEMU_ARCH_ALL)
3307 STEXI
3308 @item -s
3309 @findex -s
3310 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3311 (@pxref{gdb_usage}).
3312 ETEXI
3314 DEF("d", HAS_ARG, QEMU_OPTION_d, \
3315 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
3316 QEMU_ARCH_ALL)
3317 STEXI
3318 @item -d @var{item1}[,...]
3319 @findex -d
3320 Enable logging of specified items. Use '-d help' for a list of log items.
3321 ETEXI
3323 DEF("D", HAS_ARG, QEMU_OPTION_D, \
3324 "-D logfile output log to logfile (default stderr)\n",
3325 QEMU_ARCH_ALL)
3326 STEXI
3327 @item -D @var{logfile}
3328 @findex -D
3329 Output log in @var{logfile} instead of to stderr
3330 ETEXI
3332 DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3333 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3334 QEMU_ARCH_ALL)
3335 STEXI
3336 @item -dfilter @var{range1}[,...]
3337 @findex -dfilter
3338 Filter debug output to that relevant to a range of target addresses. The filter
3339 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3340 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3341 addresses and sizes required. For example:
3342 @example
3343 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3344 @end example
3345 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3346 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3347 block starting at 0xffffffc00005f000.
3348 ETEXI
3350 DEF("L", HAS_ARG, QEMU_OPTION_L, \
3351 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
3352 QEMU_ARCH_ALL)
3353 STEXI
3354 @item -L @var{path}
3355 @findex -L
3356 Set the directory for the BIOS, VGA BIOS and keymaps.
3358 To list all the data directories, use @code{-L help}.
3359 ETEXI
3361 DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3362 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
3363 STEXI
3364 @item -bios @var{file}
3365 @findex -bios
3366 Set the filename for the BIOS.
3367 ETEXI
3369 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3370 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3371 STEXI
3372 @item -enable-kvm
3373 @findex -enable-kvm
3374 Enable KVM full virtualization support. This option is only available
3375 if KVM support is enabled when compiling.
3376 ETEXI
3378 DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3379 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386)
3380 STEXI
3381 @item -enable-hax
3382 @findex -enable-hax
3383 Enable HAX (Hardware-based Acceleration eXecution) support. This option
3384 is only available if HAX support is enabled when compiling. HAX is only
3385 applicable to MAC and Windows platform, and thus does not conflict with
3386 KVM. This option is deprecated, use @option{-accel hax} instead.
3387 ETEXI
3389 DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3390 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
3391 DEF("xen-create", 0, QEMU_OPTION_xen_create,
3392 "-xen-create create domain using xen hypercalls, bypassing xend\n"
3393 " warning: should not be used when xend is in use\n",
3394 QEMU_ARCH_ALL)
3395 DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3396 "-xen-attach attach to existing xen domain\n"
3397 " xend will use this when starting QEMU\n",
3398 QEMU_ARCH_ALL)
3399 DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3400 "-xen-domid-restrict restrict set of available xen operations\n"
3401 " to specified domain id. (Does not affect\n"
3402 " xenpv machine type).\n",
3403 QEMU_ARCH_ALL)
3404 STEXI
3405 @item -xen-domid @var{id}
3406 @findex -xen-domid
3407 Specify xen guest domain @var{id} (XEN only).
3408 @item -xen-create
3409 @findex -xen-create
3410 Create domain using xen hypercalls, bypassing xend.
3411 Warning: should not be used when xend is in use (XEN only).
3412 @item -xen-attach
3413 @findex -xen-attach
3414 Attach to existing xen domain.
3415 xend will use this when starting QEMU (XEN only).
3416 @findex -xen-domid-restrict
3417 Restrict set of available xen operations to specified domain id (XEN only).
3418 ETEXI
3420 DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3421 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
3422 STEXI
3423 @item -no-reboot
3424 @findex -no-reboot
3425 Exit instead of rebooting.
3426 ETEXI
3428 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3429 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
3430 STEXI
3431 @item -no-shutdown
3432 @findex -no-shutdown
3433 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3434 This allows for instance switching to monitor to commit changes to the
3435 disk image.
3436 ETEXI
3438 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3439 "-loadvm [tag|id]\n" \
3440 " start right away with a saved state (loadvm in monitor)\n",
3441 QEMU_ARCH_ALL)
3442 STEXI
3443 @item -loadvm @var{file}
3444 @findex -loadvm
3445 Start right away with a saved state (@code{loadvm} in monitor)
3446 ETEXI
3448 #ifndef _WIN32
3449 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3450 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3451 #endif
3452 STEXI
3453 @item -daemonize
3454 @findex -daemonize
3455 Daemonize the QEMU process after initialization. QEMU will not detach from
3456 standard IO until it is ready to receive connections on any of its devices.
3457 This option is a useful way for external programs to launch QEMU without having
3458 to cope with initialization race conditions.
3459 ETEXI
3461 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3462 "-option-rom rom load a file, rom, into the option ROM space\n",
3463 QEMU_ARCH_ALL)
3464 STEXI
3465 @item -option-rom @var{file}
3466 @findex -option-rom
3467 Load the contents of @var{file} as an option ROM.
3468 This option is useful to load things like EtherBoot.
3469 ETEXI
3471 HXCOMM Silently ignored for compatibility
3472 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3474 HXCOMM Options deprecated by -rtc
3475 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3476 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3478 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3479 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3480 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3481 QEMU_ARCH_ALL)
3483 STEXI
3485 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3486 @findex -rtc
3487 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3488 UTC or local time, respectively. @code{localtime} is required for correct date in
3489 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3490 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3492 By default the RTC is driven by the host system time. This allows using of the
3493 RTC as accurate reference clock inside the guest, specifically if the host
3494 time is smoothly following an accurate external reference clock, e.g. via NTP.
3495 If you want to isolate the guest time from the host, you can set @option{clock}
3496 to @code{rt} instead. To even prevent it from progressing during suspension,
3497 you can set it to @code{vm}.
3499 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3500 specifically with Windows' ACPI HAL. This option will try to figure out how
3501 many timer interrupts were not processed by the Windows guest and will
3502 re-inject them.
3503 ETEXI
3505 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3506 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3507 " enable virtual instruction counter with 2^N clock ticks per\n" \
3508 " instruction, enable aligning the host and virtual clocks\n" \
3509 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3510 STEXI
3511 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3512 @findex -icount
3513 Enable virtual instruction counter. The virtual cpu will execute one
3514 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3515 then the virtual cpu speed will be automatically adjusted to keep virtual
3516 time within a few seconds of real time.
3518 When the virtual cpu is sleeping, the virtual time will advance at default
3519 speed unless @option{sleep=on|off} is specified.
3520 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3521 instantly whenever the virtual cpu goes to sleep mode and will not advance
3522 if no timer is enabled. This behavior give deterministic execution times from
3523 the guest point of view.
3525 Note that while this option can give deterministic behavior, it does not
3526 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3527 order cores with complex cache hierarchies. The number of instructions
3528 executed often has little or no correlation with actual performance.
3530 @option{align=on} will activate the delay algorithm which will try
3531 to synchronise the host clock and the virtual clock. The goal is to
3532 have a guest running at the real frequency imposed by the shift option.
3533 Whenever the guest clock is behind the host clock and if
3534 @option{align=on} is specified then we print a message to the user
3535 to inform about the delay.
3536 Currently this option does not work when @option{shift} is @code{auto}.
3537 Note: The sync algorithm will work for those shift values for which
3538 the guest clock runs ahead of the host clock. Typically this happens
3539 when the shift value is high (how high depends on the host machine).
3541 When @option{rr} option is specified deterministic record/replay is enabled.
3542 Replay log is written into @var{filename} file in record mode and
3543 read from this file in replay mode.
3545 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3546 at the start of execution recording. In replay mode this option is used
3547 to load the initial VM state.
3548 ETEXI
3550 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3551 "-watchdog model\n" \
3552 " enable virtual hardware watchdog [default=none]\n",
3553 QEMU_ARCH_ALL)
3554 STEXI
3555 @item -watchdog @var{model}
3556 @findex -watchdog
3557 Create a virtual hardware watchdog device. Once enabled (by a guest
3558 action), the watchdog must be periodically polled by an agent inside
3559 the guest or else the guest will be restarted. Choose a model for
3560 which your guest has drivers.
3562 The @var{model} is the model of hardware watchdog to emulate. Use
3563 @code{-watchdog help} to list available hardware models. Only one
3564 watchdog can be enabled for a guest.
3566 The following models may be available:
3567 @table @option
3568 @item ib700
3569 iBASE 700 is a very simple ISA watchdog with a single timer.
3570 @item i6300esb
3571 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3572 dual-timer watchdog.
3573 @item diag288
3574 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3575 (currently KVM only).
3576 @end table
3577 ETEXI
3579 DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3580 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3581 " action when watchdog fires [default=reset]\n",
3582 QEMU_ARCH_ALL)
3583 STEXI
3584 @item -watchdog-action @var{action}
3585 @findex -watchdog-action
3587 The @var{action} controls what QEMU will do when the watchdog timer
3588 expires.
3589 The default is
3590 @code{reset} (forcefully reset the guest).
3591 Other possible actions are:
3592 @code{shutdown} (attempt to gracefully shutdown the guest),
3593 @code{poweroff} (forcefully poweroff the guest),
3594 @code{inject-nmi} (inject a NMI into the guest),
3595 @code{pause} (pause the guest),
3596 @code{debug} (print a debug message and continue), or
3597 @code{none} (do nothing).
3599 Note that the @code{shutdown} action requires that the guest responds
3600 to ACPI signals, which it may not be able to do in the sort of
3601 situations where the watchdog would have expired, and thus
3602 @code{-watchdog-action shutdown} is not recommended for production use.
3604 Examples:
3606 @table @code
3607 @item -watchdog i6300esb -watchdog-action pause
3608 @itemx -watchdog ib700
3609 @end table
3610 ETEXI
3612 DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3613 "-echr chr set terminal escape character instead of ctrl-a\n",
3614 QEMU_ARCH_ALL)
3615 STEXI
3617 @item -echr @var{numeric_ascii_value}
3618 @findex -echr
3619 Change the escape character used for switching to the monitor when using
3620 monitor and serial sharing. The default is @code{0x01} when using the
3621 @code{-nographic} option. @code{0x01} is equal to pressing
3622 @code{Control-a}. You can select a different character from the ascii
3623 control keys where 1 through 26 map to Control-a through Control-z. For
3624 instance you could use the either of the following to change the escape
3625 character to Control-t.
3626 @table @code
3627 @item -echr 0x14
3628 @itemx -echr 20
3629 @end table
3630 ETEXI
3632 DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3633 "-virtioconsole c\n" \
3634 " set virtio console\n", QEMU_ARCH_ALL)
3635 STEXI
3636 @item -virtioconsole @var{c}
3637 @findex -virtioconsole
3638 Set virtio console.
3639 This option is deprecated, please use @option{-device virtconsole} instead.
3640 ETEXI
3642 DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3643 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
3644 STEXI
3645 @item -show-cursor
3646 @findex -show-cursor
3647 Show cursor.
3648 ETEXI
3650 DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3651 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
3652 STEXI
3653 @item -tb-size @var{n}
3654 @findex -tb-size
3655 Set TB size.
3656 ETEXI
3658 DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3659 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3660 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3661 "-incoming unix:socketpath\n" \
3662 " prepare for incoming migration, listen on\n" \
3663 " specified protocol and socket address\n" \
3664 "-incoming fd:fd\n" \
3665 "-incoming exec:cmdline\n" \
3666 " accept incoming migration on given file descriptor\n" \
3667 " or from given external command\n" \
3668 "-incoming defer\n" \
3669 " wait for the URI to be specified via migrate_incoming\n",
3670 QEMU_ARCH_ALL)
3671 STEXI
3672 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3673 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3674 @findex -incoming
3675 Prepare for incoming migration, listen on a given tcp port.
3677 @item -incoming unix:@var{socketpath}
3678 Prepare for incoming migration, listen on a given unix socket.
3680 @item -incoming fd:@var{fd}
3681 Accept incoming migration from a given filedescriptor.
3683 @item -incoming exec:@var{cmdline}
3684 Accept incoming migration as an output from specified external command.
3686 @item -incoming defer
3687 Wait for the URI to be specified via migrate_incoming. The monitor can
3688 be used to change settings (such as migration parameters) prior to issuing
3689 the migrate_incoming to allow the migration to begin.
3690 ETEXI
3692 DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3693 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
3694 STEXI
3695 @item -only-migratable
3696 @findex -only-migratable
3697 Only allow migratable devices. Devices will not be allowed to enter an
3698 unmigratable state.
3699 ETEXI
3701 DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3702 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
3703 STEXI
3704 @item -nodefaults
3705 @findex -nodefaults
3706 Don't create default devices. Normally, QEMU sets the default devices like serial
3707 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3708 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3709 default devices.
3710 ETEXI
3712 #ifndef _WIN32
3713 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3714 "-chroot dir chroot to dir just before starting the VM\n",
3715 QEMU_ARCH_ALL)
3716 #endif
3717 STEXI
3718 @item -chroot @var{dir}
3719 @findex -chroot
3720 Immediately before starting guest execution, chroot to the specified
3721 directory. Especially useful in combination with -runas.
3722 ETEXI
3724 #ifndef _WIN32
3725 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3726 "-runas user change to user id user just before starting the VM\n" \
3727 " user can be numeric uid:gid instead\n",
3728 QEMU_ARCH_ALL)
3729 #endif
3730 STEXI
3731 @item -runas @var{user}
3732 @findex -runas
3733 Immediately before starting guest execution, drop root privileges, switching
3734 to the specified user.
3735 ETEXI
3737 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3738 "-prom-env variable=value\n"
3739 " set OpenBIOS nvram variables\n",
3740 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3741 STEXI
3742 @item -prom-env @var{variable}=@var{value}
3743 @findex -prom-env
3744 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3745 ETEXI
3746 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3747 "-semihosting semihosting mode\n",
3748 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3749 QEMU_ARCH_MIPS)
3750 STEXI
3751 @item -semihosting
3752 @findex -semihosting
3753 Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3754 ETEXI
3755 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3756 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3757 " semihosting configuration\n",
3758 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3759 QEMU_ARCH_MIPS)
3760 STEXI
3761 @item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3762 @findex -semihosting-config
3763 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3764 @table @option
3765 @item target=@code{native|gdb|auto}
3766 Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3767 or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3768 during debug sessions and @code{native} otherwise.
3769 @item arg=@var{str1},arg=@var{str2},...
3770 Allows the user to pass input arguments, and can be used multiple times to build
3771 up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3772 command line is still supported for backward compatibility. If both the
3773 @code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3774 specified, the former is passed to semihosting as it always takes precedence.
3775 @end table
3776 ETEXI
3777 DEF("old-param", 0, QEMU_OPTION_old_param,
3778 "-old-param old param mode\n", QEMU_ARCH_ARM)
3779 STEXI
3780 @item -old-param
3781 @findex -old-param (ARM)
3782 Old param mode (ARM only).
3783 ETEXI
3785 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3786 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3787 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3788 " Enable seccomp mode 2 system call filter (default 'off').\n" \
3789 " use 'obsolete' to allow obsolete system calls that are provided\n" \
3790 " by the kernel, but typically no longer used by modern\n" \
3791 " C library implementations.\n" \
3792 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3793 " its privileges by blacklisting all set*uid|gid system calls.\n" \
3794 " The value 'children' will deny set*uid|gid system calls for\n" \
3795 " main QEMU process but will allow forks and execves to run unprivileged\n" \
3796 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3797 " blacklisting *fork and execve\n" \
3798 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
3799 QEMU_ARCH_ALL)
3800 STEXI
3801 @item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3802 @findex -sandbox
3803 Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3804 disable it. The default is 'off'.
3805 @table @option
3806 @item obsolete=@var{string}
3807 Enable Obsolete system calls
3808 @item elevateprivileges=@var{string}
3809 Disable set*uid|gid system calls
3810 @item spawn=@var{string}
3811 Disable *fork and execve
3812 @item resourcecontrol=@var{string}
3813 Disable process affinity and schedular priority
3814 @end table
3815 ETEXI
3817 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3818 "-readconfig <file>\n", QEMU_ARCH_ALL)
3819 STEXI
3820 @item -readconfig @var{file}
3821 @findex -readconfig
3822 Read device configuration from @var{file}. This approach is useful when you want to spawn
3823 QEMU process with many command line options but you don't want to exceed the command line
3824 character limit.
3825 ETEXI
3826 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3827 "-writeconfig <file>\n"
3828 " read/write config file\n", QEMU_ARCH_ALL)
3829 STEXI
3830 @item -writeconfig @var{file}
3831 @findex -writeconfig
3832 Write device configuration to @var{file}. The @var{file} can be either filename to save
3833 command line and device configuration into file or dash @code{-}) character to print the
3834 output to stdout. This can be later used as input file for @code{-readconfig} option.
3835 ETEXI
3836 HXCOMM Deprecated, same as -no-user-config
3837 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
3838 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3839 "-no-user-config\n"
3840 " do not load default user-provided config files at startup\n",
3841 QEMU_ARCH_ALL)
3842 STEXI
3843 @item -no-user-config
3844 @findex -no-user-config
3845 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3846 config files on @var{sysconfdir}.
3847 ETEXI
3848 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3849 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3850 " specify tracing options\n",
3851 QEMU_ARCH_ALL)
3852 STEXI
3853 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3854 HXCOMM HX does not support conditional compilation of text.
3855 @item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3856 @findex -trace
3857 @include qemu-option-trace.texi
3858 ETEXI
3860 HXCOMM Internal use
3861 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3862 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3864 #ifdef __linux__
3865 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3866 "-enable-fips enable FIPS 140-2 compliance\n",
3867 QEMU_ARCH_ALL)
3868 #endif
3869 STEXI
3870 @item -enable-fips
3871 @findex -enable-fips
3872 Enable FIPS 140-2 compliance mode.
3873 ETEXI
3875 HXCOMM Deprecated by -machine accel=tcg property
3876 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3878 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3879 "-msg timestamp[=on|off]\n"
3880 " change the format of messages\n"
3881 " on|off controls leading timestamps (default:on)\n",
3882 QEMU_ARCH_ALL)
3883 STEXI
3884 @item -msg timestamp[=on|off]
3885 @findex -msg
3886 prepend a timestamp to each log message.(default:on)
3887 ETEXI
3889 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3890 "-dump-vmstate <file>\n"
3891 " Output vmstate information in JSON format to file.\n"
3892 " Use the scripts/vmstate-static-checker.py file to\n"
3893 " check for possible regressions in migration code\n"
3894 " by comparing two such vmstate dumps.\n",
3895 QEMU_ARCH_ALL)
3896 STEXI
3897 @item -dump-vmstate @var{file}
3898 @findex -dump-vmstate
3899 Dump json-encoded vmstate information for current machine type to file
3900 in @var{file}
3901 ETEXI
3903 DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
3904 "-enable-sync-profile\n"
3905 " enable synchronization profiling\n",
3906 QEMU_ARCH_ALL)
3907 STEXI
3908 @item -enable-sync-profile
3909 @findex -enable-sync-profile
3910 Enable synchronization profiling.
3911 ETEXI
3913 STEXI
3914 @end table
3915 ETEXI
3916 DEFHEADING()
3918 DEFHEADING(Generic object creation:)
3919 STEXI
3920 @table @option
3921 ETEXI
3923 DEF("object", HAS_ARG, QEMU_OPTION_object,
3924 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3925 " create a new object of type TYPENAME setting properties\n"
3926 " in the order they are specified. Note that the 'id'\n"
3927 " property must be set. These objects are placed in the\n"
3928 " '/objects' path.\n",
3929 QEMU_ARCH_ALL)
3930 STEXI
3931 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3932 @findex -object
3933 Create a new object of type @var{typename} setting properties
3934 in the order they are specified. Note that the 'id'
3935 property must be set. These objects are placed in the
3936 '/objects' path.
3938 @table @option
3940 @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}
3942 Creates a memory file backend object, which can be used to back
3943 the guest RAM with huge pages.
3945 The @option{id} parameter is a unique ID that will be used to reference this
3946 memory region when configuring the @option{-numa} argument.
3948 The @option{size} option provides the size of the memory region, and accepts
3949 common suffixes, eg @option{500M}.
3951 The @option{mem-path} provides the path to either a shared memory or huge page
3952 filesystem mount.
3954 The @option{share} boolean option determines whether the memory
3955 region is marked as private to QEMU, or shared. The latter allows
3956 a co-operating external process to access the QEMU memory region.
3958 The @option{share} is also required for pvrdma devices due to
3959 limitations in the RDMA API provided by Linux.
3961 Setting share=on might affect the ability to configure NUMA
3962 bindings for the memory backend under some circumstances, see
3963 Documentation/vm/numa_memory_policy.txt on the Linux kernel
3964 source tree for additional details.
3966 Setting the @option{discard-data} boolean option to @var{on}
3967 indicates that file contents can be destroyed when QEMU exits,
3968 to avoid unnecessarily flushing data to the backing file. Note
3969 that @option{discard-data} is only an optimization, and QEMU
3970 might not discard file contents if it aborts unexpectedly or is
3971 terminated using SIGKILL.
3973 The @option{merge} boolean option enables memory merge, also known as
3974 MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
3975 memory deduplication.
3977 Setting the @option{dump} boolean option to @var{off} excludes the memory from
3978 core dumps. This feature is also known as MADV_DONTDUMP.
3980 The @option{prealloc} boolean option enables memory preallocation.
3982 The @option{host-nodes} option binds the memory range to a list of NUMA host
3983 nodes.
3985 The @option{policy} option sets the NUMA policy to one of the following values:
3987 @table @option
3988 @item @var{default}
3989 default host policy
3991 @item @var{preferred}
3992 prefer the given host node list for allocation
3994 @item @var{bind}
3995 restrict memory allocation to the given host node list
3997 @item @var{interleave}
3998 interleave memory allocations across the given host node list
3999 @end table
4001 The @option{align} option specifies the base address alignment when
4002 QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
4003 @option{2M}. Some backend store specified by @option{mem-path}
4004 requires an alignment different than the default one used by QEMU, eg
4005 the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4006 such cases, users can specify the required alignment via this option.
4008 The @option{pmem} option specifies whether the backing file specified
4009 by @option{mem-path} is in host persistent memory that can be accessed
4010 using the SNIA NVM programming model (e.g. Intel NVDIMM).
4011 If @option{pmem} is set to 'on', QEMU will take necessary operations to
4012 guarantee the persistence of its own writes to @option{mem-path}
4013 (e.g. in vNVDIMM label emulation and live migration).
4015 @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}
4017 Creates a memory backend object, which can be used to back the guest RAM.
4018 Memory backend objects offer more control than the @option{-m} option that is
4019 traditionally used to define guest RAM. Please refer to
4020 @option{memory-backend-file} for a description of the options.
4022 @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}
4024 Creates an anonymous memory file backend object, which allows QEMU to
4025 share the memory with an external process (e.g. when using
4026 vhost-user). The memory is allocated with memfd and optional
4027 sealing. (Linux only)
4029 The @option{seal} option creates a sealed-file, that will block
4030 further resizing the memory ('on' by default).
4032 The @option{hugetlb} option specify the file to be created resides in
4033 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with
4034 the @option{hugetlb} option, the @option{hugetlbsize} option specify
4035 the hugetlb page size on systems that support multiple hugetlb page
4036 sizes (it must be a power of 2 value supported by the system).
4038 In some versions of Linux, the @option{hugetlb} option is incompatible
4039 with the @option{seal} option (requires at least Linux 4.16).
4041 Please refer to @option{memory-backend-file} for a description of the
4042 other options.
4044 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
4046 Creates a random number generator backend which obtains entropy from
4047 a device on the host. The @option{id} parameter is a unique ID that
4048 will be used to reference this entropy backend from the @option{virtio-rng}
4049 device. The @option{filename} parameter specifies which file to obtain
4050 entropy from and if omitted defaults to @option{/dev/random}.
4052 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4054 Creates a random number generator backend which obtains entropy from
4055 an external daemon running on the host. The @option{id} parameter is
4056 a unique ID that will be used to reference this entropy backend from
4057 the @option{virtio-rng} device. The @option{chardev} parameter is
4058 the unique ID of a character device backend that provides the connection
4059 to the RNG daemon.
4061 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4063 Creates a TLS anonymous credentials object, which can be used to provide
4064 TLS support on network backends. The @option{id} parameter is a unique
4065 ID which network backends will use to access the credentials. The
4066 @option{endpoint} is either @option{server} or @option{client} depending
4067 on whether the QEMU network backend that uses the credentials will be
4068 acting as a client or as a server. If @option{verify-peer} is enabled
4069 (the default) then once the handshake is completed, the peer credentials
4070 will be verified, though this is a no-op for anonymous credentials.
4072 The @var{dir} parameter tells QEMU where to find the credential
4073 files. For server endpoints, this directory may contain a file
4074 @var{dh-params.pem} providing diffie-hellman parameters to use
4075 for the TLS server. If the file is missing, QEMU will generate
4076 a set of DH parameters at startup. This is a computationally
4077 expensive operation that consumes random pool entropy, so it is
4078 recommended that a persistent set of parameters be generated
4079 upfront and saved.
4081 @item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}]
4083 Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide
4084 TLS support on network backends. The @option{id} parameter is a unique
4085 ID which network backends will use to access the credentials. The
4086 @option{endpoint} is either @option{server} or @option{client} depending
4087 on whether the QEMU network backend that uses the credentials will be
4088 acting as a client or as a server. For clients only, @option{username}
4089 is the username which will be sent to the server. If omitted
4090 it defaults to ``qemu''.
4092 The @var{dir} parameter tells QEMU where to find the keys file.
4093 It is called ``@var{dir}/keys.psk'' and contains ``username:key''
4094 pairs. This file can most easily be created using the GnuTLS
4095 @code{psktool} program.
4097 For server endpoints, @var{dir} may also contain a file
4098 @var{dh-params.pem} providing diffie-hellman parameters to use
4099 for the TLS server. If the file is missing, QEMU will generate
4100 a set of DH parameters at startup. This is a computationally
4101 expensive operation that consumes random pool entropy, so it is
4102 recommended that a persistent set of parameters be generated
4103 up front and saved.
4105 @item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},priority=@var{priority},verify-peer=@var{on|off},passwordid=@var{id}
4107 Creates a TLS anonymous credentials object, which can be used to provide
4108 TLS support on network backends. The @option{id} parameter is a unique
4109 ID which network backends will use to access the credentials. The
4110 @option{endpoint} is either @option{server} or @option{client} depending
4111 on whether the QEMU network backend that uses the credentials will be
4112 acting as a client or as a server. If @option{verify-peer} is enabled
4113 (the default) then once the handshake is completed, the peer credentials
4114 will be verified. With x509 certificates, this implies that the clients
4115 must be provided with valid client certificates too.
4117 The @var{dir} parameter tells QEMU where to find the credential
4118 files. For server endpoints, this directory may contain a file
4119 @var{dh-params.pem} providing diffie-hellman parameters to use
4120 for the TLS server. If the file is missing, QEMU will generate
4121 a set of DH parameters at startup. This is a computationally
4122 expensive operation that consumes random pool entropy, so it is
4123 recommended that a persistent set of parameters be generated
4124 upfront and saved.
4126 For x509 certificate credentials the directory will contain further files
4127 providing the x509 certificates. The certificates must be stored
4128 in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4129 @var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4130 @var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4132 For the @var{server-key.pem} and @var{client-key.pem} files which
4133 contain sensitive private keys, it is possible to use an encrypted
4134 version by providing the @var{passwordid} parameter. This provides
4135 the ID of a previously created @code{secret} object containing the
4136 password for decryption.
4138 The @var{priority} parameter allows to override the global default
4139 priority used by gnutls. This can be useful if the system administrator
4140 needs to use a weaker set of crypto priorities for QEMU without
4141 potentially forcing the weakness onto all applications. Or conversely
4142 if one wants wants a stronger default for QEMU than for all other
4143 applications, they can do this through this parameter. Its format is
4144 a gnutls priority string as described at
4145 @url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4147 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4149 Interval @var{t} can't be 0, this filter batches the packet delivery: all
4150 packets arriving in a given interval on netdev @var{netdevid} are delayed
4151 until the end of the interval. Interval is in microseconds.
4152 @option{status} is optional that indicate whether the netfilter is
4153 on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4155 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4157 @option{all}: the filter is attached both to the receive and the transmit
4158 queue of the netdev (default).
4160 @option{rx}: the filter is attached to the receive queue of the netdev,
4161 where it will receive packets sent to the netdev.
4163 @option{tx}: the filter is attached to the transmit queue of the netdev,
4164 where it will receive packets sent by the netdev.
4166 @item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4168 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.
4170 @item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4172 filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4173 @var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4174 filter-redirector will redirect packet with vnet_hdr_len.
4175 Create a filter-redirector we need to differ outdev id from indev id, id can not
4176 be the same. we can just use indev or outdev, but at least one of indev or outdev
4177 need to be specified.
4179 @item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4181 Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4182 secondary from primary to keep secondary tcp connection,and rewrite
4183 tcp packet to primary from secondary make tcp packet can be handled by
4184 client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4186 usage:
4187 colo secondary:
4188 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4189 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4190 -object filter-rewriter,id=rew0,netdev=hn0,queue=all
4192 @item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4194 Dump the network traffic on netdev @var{dev} to the file specified by
4195 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4196 The file format is libpcap, so it can be analyzed with tools such as tcpdump
4197 or Wireshark.
4199 @item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4201 Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4202 secondary packet. If the packets are same, we will output primary
4203 packet to outdev@var{chardevid}, else we will notify colo-frame
4204 do checkpoint and send primary packet to outdev@var{chardevid}.
4205 if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4207 we must use it with the help of filter-mirror and filter-redirector.
4209 @example
4211 primary:
4212 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4213 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4214 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4215 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4216 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4217 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4218 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4219 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4220 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4221 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4222 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4223 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4225 secondary:
4226 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4227 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4228 -chardev socket,id=red0,host=3.3.3.3,port=9003
4229 -chardev socket,id=red1,host=3.3.3.3,port=9004
4230 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4231 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4233 @end example
4235 If you want to know the detail of above command line, you can read
4236 the colo-compare git log.
4238 @item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4240 Creates a cryptodev backend which executes crypto opreation from
4241 the QEMU cipher APIS. The @var{id} parameter is
4242 a unique ID that will be used to reference this cryptodev backend from
4243 the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4244 which specify the queue number of cryptodev backend, the default of
4245 @var{queues} is 1.
4247 @example
4249 # qemu-system-x86_64 \
4250 [...] \
4251 -object cryptodev-backend-builtin,id=cryptodev0 \
4252 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4253 [...]
4254 @end example
4256 @item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4258 Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4259 The @var{id} parameter is a unique ID that will be used to reference this
4260 cryptodev backend from the @option{virtio-crypto} device.
4261 The chardev should be a unix domain socket backed one. The vhost-user uses
4262 a specifically defined protocol to pass vhost ioctl replacement messages
4263 to an application on the other end of the socket.
4264 The @var{queues} parameter is optional, which specify the queue number
4265 of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4267 @example
4269 # qemu-system-x86_64 \
4270 [...] \
4271 -chardev socket,id=chardev0,path=/path/to/socket \
4272 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4273 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4274 [...]
4275 @end example
4277 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4278 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4280 Defines a secret to store a password, encryption key, or some other sensitive
4281 data. The sensitive data can either be passed directly via the @var{data}
4282 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4283 parameter is insecure unless the sensitive data is encrypted.
4285 The sensitive data can be provided in raw format (the default), or base64.
4286 When encoded as JSON, the raw format only supports valid UTF-8 characters,
4287 so base64 is recommended for sending binary data. QEMU will convert from
4288 which ever format is provided to the format it needs internally. eg, an
4289 RBD password can be provided in raw format, even though it will be base64
4290 encoded when passed onto the RBD sever.
4292 For added protection, it is possible to encrypt the data associated with
4293 a secret using the AES-256-CBC cipher. Use of encryption is indicated
4294 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4295 parameter provides the ID of a previously defined secret that contains
4296 the AES-256 decryption key. This key should be 32-bytes long and be
4297 base64 encoded. The @var{iv} parameter provides the random initialization
4298 vector used for encryption of this particular secret and should be a
4299 base64 encrypted string of the 16-byte IV.
4301 The simplest (insecure) usage is to provide the secret inline
4303 @example
4305 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4307 @end example
4309 The simplest secure usage is to provide the secret via a file
4311 # printf "letmein" > mypasswd.txt
4312 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4314 For greater security, AES-256-CBC should be used. To illustrate usage,
4315 consider the openssl command line tool which can encrypt the data. Note
4316 that when encrypting, the plaintext must be padded to the cipher block
4317 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4319 First a master key needs to be created in base64 encoding:
4321 @example
4322 # openssl rand -base64 32 > key.b64
4323 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
4324 @end example
4326 Each secret to be encrypted needs to have a random initialization vector
4327 generated. These do not need to be kept secret
4329 @example
4330 # openssl rand -base64 16 > iv.b64
4331 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
4332 @end example
4334 The secret to be defined can now be encrypted, in this case we're
4335 telling openssl to base64 encode the result, but it could be left
4336 as raw bytes if desired.
4338 @example
4339 # SECRET=$(printf "letmein" |
4340 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4341 @end example
4343 When launching QEMU, create a master secret pointing to @code{key.b64}
4344 and specify that to be used to decrypt the user password. Pass the
4345 contents of @code{iv.b64} to the second secret
4347 @example
4348 # $QEMU \
4349 -object secret,id=secmaster0,format=base64,file=key.b64 \
4350 -object secret,id=sec0,keyid=secmaster0,format=base64,\
4351 data=$SECRET,iv=$(<iv.b64)
4352 @end example
4354 @item -object sev-guest,id=@var{id},cbitpos=@var{cbitpos},reduced-phys-bits=@var{val},[sev-device=@var{string},policy=@var{policy},handle=@var{handle},dh-cert-file=@var{file},session-file=@var{file}]
4356 Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4357 to provide the guest memory encryption support on AMD processors.
4359 When memory encryption is enabled, one of the physical address bit (aka the
4360 C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4361 is used to provide the C-bit position. The C-bit position is Host family dependent
4362 hence user must provide this value. On EPYC, the value should be 47.
4364 When memory encryption is enabled, we loose certain bits in physical address space.
4365 The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4366 physical address space. Similar to C-bit, the value is Host family dependent.
4367 On EPYC, the value should be 5.
4369 The @option{sev-device} provides the device file to use for communicating with
4370 the SEV firmware running inside AMD Secure Processor. The default device is
4371 '/dev/sev'. If hardware supports memory encryption then /dev/sev devices are
4372 created by CCP driver.
4374 The @option{policy} provides the guest policy to be enforced by the SEV firmware
4375 and restrict what configuration and operational commands can be performed on this
4376 guest by the hypervisor. The policy should be provided by the guest owner and is
4377 bound to the guest and cannot be changed throughout the lifetime of the guest.
4378 The default is 0.
4380 If guest @option{policy} allows sharing the key with another SEV guest then
4381 @option{handle} can be use to provide handle of the guest from which to share
4382 the key.
4384 The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4385 Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters
4386 are used for establishing a cryptographic session with the guest owner to
4387 negotiate keys used for attestation. The file must be encoded in base64.
4389 e.g to launch a SEV guest
4390 @example
4391 # $QEMU \
4392 ......
4393 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \
4394 -machine ...,memory-encryption=sev0
4395 .....
4397 @end example
4398 @end table
4400 ETEXI
4403 HXCOMM This is the last statement. Insert new options before this line!
4404 STEXI
4405 @end table
4406 ETEXI