qcow2: Split do_perform_cow() into _read(), _encrypt() and _write()
[qemu/ar7.git] / qemu-options.hx
blob896ff177c311f688fb6b5f9de24ee81e2f16b1c8
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 or tcg (default: tcg)\n"
35 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n"
36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
37 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n"
38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
39 " mem-merge=on|off controls memory merge support (default: on)\n"
40 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
44 " nvdimm=on|off controls NVDIMM support (default=off)\n"
45 " enforce-config-section=on|off enforce configuration section migration (default=off)\n"
46 " s390-squash-mcss=on|off controls support for squashing into default css (default=off)\n",
47 QEMU_ARCH_ALL)
48 STEXI
49 @item -machine [type=]@var{name}[,prop=@var{value}[,...]]
50 @findex -machine
51 Select the emulated machine by @var{name}. Use @code{-machine help} to list
52 available machines. Supported machine properties are:
53 @table @option
54 @item accel=@var{accels1}[:@var{accels2}[:...]]
55 This is used to enable an accelerator. Depending on the target architecture,
56 kvm, xen, hax or tcg can be available. By default, tcg is used. If there is
57 more than one accelerator specified, the next one is used if the previous one
58 fails to initialize.
59 @item kernel_irqchip=on|off
60 Controls in-kernel irqchip support for the chosen accelerator when available.
61 @item gfx_passthru=on|off
62 Enables IGD GFX passthrough support for the chosen machine when available.
63 @item vmport=on|off|auto
64 Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
65 value based on accel. For accel=xen the default is off otherwise the default
66 is on.
67 @item kvm_shadow_mem=size
68 Defines the size of the KVM shadow MMU.
69 @item dump-guest-core=on|off
70 Include guest memory in a core dump. The default is on.
71 @item mem-merge=on|off
72 Enables or disables memory merge support. This feature, when supported by
73 the host, de-duplicates identical memory pages among VMs instances
74 (enabled by default).
75 @item aes-key-wrap=on|off
76 Enables or disables AES key wrapping support on s390-ccw hosts. This feature
77 controls whether AES wrapping keys will be created to allow
78 execution of AES cryptographic functions. The default is on.
79 @item dea-key-wrap=on|off
80 Enables or disables DEA key wrapping support on s390-ccw hosts. This feature
81 controls whether DEA wrapping keys will be created to allow
82 execution of DEA cryptographic functions. The default is on.
83 @item nvdimm=on|off
84 Enables or disables NVDIMM support. The default is off.
85 @item s390-squash-mcss=on|off
86 Enables or disables squashing subchannels into the default css.
87 The default is off.
88 @end table
89 ETEXI
91 HXCOMM Deprecated by -machine
92 DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
94 DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
95 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
96 STEXI
97 @item -cpu @var{model}
98 @findex -cpu
99 Select CPU model (@code{-cpu help} for list and additional feature selection)
100 ETEXI
102 DEF("accel", HAS_ARG, QEMU_OPTION_accel,
103 "-accel [accel=]accelerator[,thread=single|multi]\n"
104 " select accelerator (kvm, xen, hax or tcg; use 'help' for a list)\n"
105 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL)
106 STEXI
107 @item -accel @var{name}[,prop=@var{value}[,...]]
108 @findex -accel
109 This is used to enable an accelerator. Depending on the target architecture,
110 kvm, xen, hax or tcg can be available. By default, tcg is used. If there is
111 more than one accelerator specified, the next one is used if the previous one
112 fails to initialize.
113 @table @option
114 @item thread=single|multi
115 Controls number of TCG threads. When the TCG is multi-threaded there will be one
116 thread per vCPU therefor taking advantage of additional host cores. The default
117 is to enable multi-threading where both the back-end and front-ends support it and
118 no incompatible TCG features have been enabled (e.g. icount/replay).
119 @end table
120 ETEXI
122 DEF("smp", HAS_ARG, QEMU_OPTION_smp,
123 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
124 " set the number of CPUs to 'n' [default=1]\n"
125 " maxcpus= maximum number of total cpus, including\n"
126 " offline CPUs for hotplug, etc\n"
127 " cores= number of CPU cores on one socket\n"
128 " threads= number of threads on one CPU core\n"
129 " sockets= number of discrete sockets in the system\n",
130 QEMU_ARCH_ALL)
131 STEXI
132 @item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
133 @findex -smp
134 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
135 CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
136 to 4.
137 For the PC target, the number of @var{cores} per socket, the number
138 of @var{threads} per cores and the total number of @var{sockets} can be
139 specified. Missing values will be computed. If any on the three values is
140 given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
141 specifies the maximum number of hotpluggable CPUs.
142 ETEXI
144 DEF("numa", HAS_ARG, QEMU_OPTION_numa,
145 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
146 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
147 "-numa dist,src=source,dst=destination,val=distance\n", QEMU_ARCH_ALL)
148 STEXI
149 @item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
150 @itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
151 @itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance}
152 @itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}]
153 @findex -numa
154 Define a NUMA node and assign RAM and VCPUs to it.
155 Set the NUMA distance from a source node to a destination node.
157 Legacy VCPU assignment uses @samp{cpus} option where
158 @var{firstcpu} and @var{lastcpu} are CPU indexes. Each
159 @samp{cpus} option represent a contiguous range of CPU indexes
160 (or a single VCPU if @var{lastcpu} is omitted). A non-contiguous
161 set of VCPUs can be represented by providing multiple @samp{cpus}
162 options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically
163 split between them.
165 For example, the following option assigns VCPUs 0, 1, 2 and 5 to
166 a NUMA node:
167 @example
168 -numa node,cpus=0-2,cpus=5
169 @end example
171 @samp{cpu} option is a new alternative to @samp{cpus} option
172 which uses @samp{socket-id|core-id|thread-id} properties to assign
173 CPU objects to a @var{node} using topology layout properties of CPU.
174 The set of properties is machine specific, and depends on used
175 machine type/@samp{smp} options. It could be queried with
176 @samp{hotpluggable-cpus} monitor command.
177 @samp{node-id} property specifies @var{node} to which CPU object
178 will be assigned, it's required for @var{node} to be declared
179 with @samp{node} option before it's used with @samp{cpu} option.
181 For example:
182 @example
183 -M pc \
184 -smp 1,sockets=2,maxcpus=2 \
185 -numa node,nodeid=0 -numa node,nodeid=1 \
186 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
187 @end example
189 @samp{mem} assigns a given RAM amount to a node. @samp{memdev}
190 assigns RAM from a given memory backend device to a node. If
191 @samp{mem} and @samp{memdev} are omitted in all nodes, RAM is
192 split equally between them.
194 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
195 if one node uses @samp{memdev}, all of them have to use it.
197 @var{source} and @var{destination} are NUMA node IDs.
198 @var{distance} is the NUMA distance from @var{source} to @var{destination}.
199 The distance from a node to itself is always 10. If any pair of nodes is
200 given a distance, then all pairs must be given distances. Although, when
201 distances are only given in one direction for each pair of nodes, then
202 the distances in the opposite directions are assumed to be the same. If,
203 however, an asymmetrical pair of distances is given for even one node
204 pair, then all node pairs must be provided distance values for both
205 directions, even when they are symmetrical. When a node is unreachable
206 from another node, set the pair's distance to 255.
208 Note that the -@option{numa} option doesn't allocate any of the
209 specified resources, it just assigns existing resources to NUMA
210 nodes. This means that one still has to use the @option{-m},
211 @option{-smp} options to allocate RAM and VCPUs respectively.
213 ETEXI
215 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
216 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
217 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
218 STEXI
219 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
220 @findex -add-fd
222 Add a file descriptor to an fd set. Valid options are:
224 @table @option
225 @item fd=@var{fd}
226 This option defines the file descriptor of which a duplicate is added to fd set.
227 The file descriptor cannot be stdin, stdout, or stderr.
228 @item set=@var{set}
229 This option defines the ID of the fd set to add the file descriptor to.
230 @item opaque=@var{opaque}
231 This option defines a free-form string that can be used to describe @var{fd}.
232 @end table
234 You can open an image using pre-opened file descriptors from an fd set:
235 @example
236 qemu-system-i386
237 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
238 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
239 -drive file=/dev/fdset/2,index=0,media=disk
240 @end example
241 ETEXI
243 DEF("set", HAS_ARG, QEMU_OPTION_set,
244 "-set group.id.arg=value\n"
245 " set <arg> parameter for item <id> of type <group>\n"
246 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
247 STEXI
248 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
249 @findex -set
250 Set parameter @var{arg} for item @var{id} of type @var{group}
251 ETEXI
253 DEF("global", HAS_ARG, QEMU_OPTION_global,
254 "-global driver.property=value\n"
255 "-global driver=driver,property=property,value=value\n"
256 " set a global default for a driver property\n",
257 QEMU_ARCH_ALL)
258 STEXI
259 @item -global @var{driver}.@var{prop}=@var{value}
260 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
261 @findex -global
262 Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
264 @example
265 qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
266 @end example
268 In particular, you can use this to set driver properties for devices which are
269 created automatically by the machine model. To create a device which is not
270 created automatically and set properties on it, use -@option{device}.
272 -global @var{driver}.@var{prop}=@var{value} is shorthand for -global
273 driver=@var{driver},property=@var{prop},value=@var{value}. The
274 longhand syntax works even when @var{driver} contains a dot.
275 ETEXI
277 DEF("boot", HAS_ARG, QEMU_OPTION_boot,
278 "-boot [order=drives][,once=drives][,menu=on|off]\n"
279 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
280 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
281 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
282 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
283 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
284 QEMU_ARCH_ALL)
285 STEXI
286 @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]
287 @findex -boot
288 Specify boot order @var{drives} as a string of drive letters. Valid
289 drive letters depend on the target architecture. The x86 PC uses: a, b
290 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
291 from network adapter 1-4), hard disk boot is the default. To apply a
292 particular boot order only on the first startup, specify it via
293 @option{once}. Note that the @option{order} or @option{once} parameter
294 should not be used together with the @option{bootindex} property of
295 devices, since the firmware implementations normally do not support both
296 at the same time.
298 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
299 as firmware/BIOS supports them. The default is non-interactive boot.
301 A splash picture could be passed to bios, enabling user to show it as logo,
302 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
303 supports them. Currently Seabios for X86 system support it.
304 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
305 format(true color). The resolution should be supported by the SVGA mode, so
306 the recommended is 320x240, 640x480, 800x640.
308 A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
309 when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
310 reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
311 system support it.
313 Do strict boot via @option{strict=on} as far as firmware/BIOS
314 supports it. This only effects when boot priority is changed by
315 bootindex options. The default is non-strict boot.
317 @example
318 # try to boot from network first, then from hard disk
319 qemu-system-i386 -boot order=nc
320 # boot from CD-ROM first, switch back to default order after reboot
321 qemu-system-i386 -boot once=d
322 # boot with a splash picture for 5 seconds.
323 qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
324 @end example
326 Note: The legacy format '-boot @var{drives}' is still supported but its
327 use is discouraged as it may be removed from future versions.
328 ETEXI
330 DEF("m", HAS_ARG, QEMU_OPTION_m,
331 "-m [size=]megs[,slots=n,maxmem=size]\n"
332 " configure guest RAM\n"
333 " size: initial amount of guest memory\n"
334 " slots: number of hotplug slots (default: none)\n"
335 " maxmem: maximum amount of guest memory (default: none)\n"
336 "NOTE: Some architectures might enforce a specific granularity\n",
337 QEMU_ARCH_ALL)
338 STEXI
339 @item -m [size=]@var{megs}[,slots=n,maxmem=size]
340 @findex -m
341 Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
342 Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
343 megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
344 could be used to set amount of hotpluggable memory slots and maximum amount of
345 memory. Note that @var{maxmem} must be aligned to the page size.
347 For example, the following command-line sets the guest startup RAM size to
348 1GB, creates 3 slots to hotplug additional memory and sets the maximum
349 memory the guest can reach to 4GB:
351 @example
352 qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
353 @end example
355 If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
356 be enabled and the guest startup RAM will never increase.
357 ETEXI
359 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
360 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
361 STEXI
362 @item -mem-path @var{path}
363 @findex -mem-path
364 Allocate guest RAM from a temporarily created file in @var{path}.
365 ETEXI
367 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
368 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
369 QEMU_ARCH_ALL)
370 STEXI
371 @item -mem-prealloc
372 @findex -mem-prealloc
373 Preallocate memory when using -mem-path.
374 ETEXI
376 DEF("k", HAS_ARG, QEMU_OPTION_k,
377 "-k language use keyboard layout (for example 'fr' for French)\n",
378 QEMU_ARCH_ALL)
379 STEXI
380 @item -k @var{language}
381 @findex -k
382 Use keyboard layout @var{language} (for example @code{fr} for
383 French). This option is only needed where it is not easy to get raw PC
384 keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
385 display). You don't normally need to use it on PC/Linux or PC/Windows
386 hosts.
388 The available layouts are:
389 @example
390 ar de-ch es fo fr-ca hu ja mk no pt-br sv
391 da en-gb et fr fr-ch is lt nl pl ru th
392 de en-us fi fr-be hr it lv nl-be pt sl tr
393 @end example
395 The default is @code{en-us}.
396 ETEXI
399 DEF("audio-help", 0, QEMU_OPTION_audio_help,
400 "-audio-help print list of audio drivers and their options\n",
401 QEMU_ARCH_ALL)
402 STEXI
403 @item -audio-help
404 @findex -audio-help
405 Will show the audio subsystem help: list of drivers, tunable
406 parameters.
407 ETEXI
409 DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
410 "-soundhw c1,... enable audio support\n"
411 " and only specified sound cards (comma separated list)\n"
412 " use '-soundhw help' to get the list of supported cards\n"
413 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
414 STEXI
415 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
416 @findex -soundhw
417 Enable audio and selected sound hardware. Use 'help' to print all
418 available sound hardware.
420 @example
421 qemu-system-i386 -soundhw sb16,adlib disk.img
422 qemu-system-i386 -soundhw es1370 disk.img
423 qemu-system-i386 -soundhw ac97 disk.img
424 qemu-system-i386 -soundhw hda disk.img
425 qemu-system-i386 -soundhw all disk.img
426 qemu-system-i386 -soundhw help
427 @end example
429 Note that Linux's i810_audio OSS kernel (for AC97) module might
430 require manually specifying clocking.
432 @example
433 modprobe i810_audio clocking=48000
434 @end example
435 ETEXI
437 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
438 "-balloon none disable balloon device\n"
439 "-balloon virtio[,addr=str]\n"
440 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
441 STEXI
442 @item -balloon none
443 @findex -balloon
444 Disable balloon device.
445 @item -balloon virtio[,addr=@var{addr}]
446 Enable virtio balloon device (default), optionally with PCI address
447 @var{addr}.
448 ETEXI
450 DEF("device", HAS_ARG, QEMU_OPTION_device,
451 "-device driver[,prop[=value][,...]]\n"
452 " add device (based on driver)\n"
453 " prop=value,... sets driver properties\n"
454 " use '-device help' to print all possible drivers\n"
455 " use '-device driver,help' to print all possible properties\n",
456 QEMU_ARCH_ALL)
457 STEXI
458 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
459 @findex -device
460 Add device @var{driver}. @var{prop}=@var{value} sets driver
461 properties. Valid properties depend on the driver. To get help on
462 possible drivers and properties, use @code{-device help} and
463 @code{-device @var{driver},help}.
465 Some drivers are:
466 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
468 Add an IPMI BMC. This is a simulation of a hardware management
469 interface processor that normally sits on a system. It provides
470 a watchdog and the ability to reset and power control the system.
471 You need to connect this to an IPMI interface to make it useful
473 The IPMI slave address to use for the BMC. The default is 0x20.
474 This address is the BMC's address on the I2C network of management
475 controllers. If you don't know what this means, it is safe to ignore
478 @table @option
479 @item bmc=@var{id}
480 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
481 @item slave_addr=@var{val}
482 Define slave address to use for the BMC. The default is 0x20.
483 @item sdrfile=@var{file}
484 file containing raw Sensor Data Records (SDR) data. The default is none.
485 @item fruareasize=@var{val}
486 size of a Field Replaceable Unit (FRU) area. The default is 1024.
487 @item frudatafile=@var{file}
488 file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
489 @end table
491 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
493 Add a connection to an external IPMI BMC simulator. Instead of
494 locally emulating the BMC like the above item, instead connect
495 to an external entity that provides the IPMI services.
497 A connection is made to an external BMC simulator. If you do this, it
498 is strongly recommended that you use the "reconnect=" chardev option
499 to reconnect to the simulator if the connection is lost. Note that if
500 this is not used carefully, it can be a security issue, as the
501 interface has the ability to send resets, NMIs, and power off the VM.
502 It's best if QEMU makes a connection to an external simulator running
503 on a secure port on localhost, so neither the simulator nor QEMU is
504 exposed to any outside network.
506 See the "lanserv/README.vm" file in the OpenIPMI library for more
507 details on the external interface.
509 @item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
511 Add a KCS IPMI interafce on the ISA bus. This also adds a
512 corresponding ACPI and SMBIOS entries, if appropriate.
514 @table @option
515 @item bmc=@var{id}
516 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
517 @item ioport=@var{val}
518 Define the I/O address of the interface. The default is 0xca0 for KCS.
519 @item irq=@var{val}
520 Define the interrupt to use. The default is 5. To disable interrupts,
521 set this to 0.
522 @end table
524 @item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
526 Like the KCS interface, but defines a BT interface. The default port is
527 0xe4 and the default interrupt is 5.
529 ETEXI
531 DEF("name", HAS_ARG, QEMU_OPTION_name,
532 "-name string1[,process=string2][,debug-threads=on|off]\n"
533 " set the name of the guest\n"
534 " string1 sets the window title and string2 the process name (on Linux)\n"
535 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
536 " NOTE: The thread names are for debugging and not a stable API.\n",
537 QEMU_ARCH_ALL)
538 STEXI
539 @item -name @var{name}
540 @findex -name
541 Sets the @var{name} of the guest.
542 This name will be displayed in the SDL window caption.
543 The @var{name} will also be used for the VNC server.
544 Also optionally set the top visible process name in Linux.
545 Naming of individual threads can also be enabled on Linux to aid debugging.
546 ETEXI
548 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
549 "-uuid %08x-%04x-%04x-%04x-%012x\n"
550 " specify machine UUID\n", QEMU_ARCH_ALL)
551 STEXI
552 @item -uuid @var{uuid}
553 @findex -uuid
554 Set system UUID.
555 ETEXI
557 STEXI
558 @end table
559 ETEXI
560 DEFHEADING()
562 DEFHEADING(Block device options)
563 STEXI
564 @table @option
565 ETEXI
567 DEF("fda", HAS_ARG, QEMU_OPTION_fda,
568 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
569 DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
570 STEXI
571 @item -fda @var{file}
572 @itemx -fdb @var{file}
573 @findex -fda
574 @findex -fdb
575 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
576 ETEXI
578 DEF("hda", HAS_ARG, QEMU_OPTION_hda,
579 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
580 DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
581 DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
582 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
583 DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
584 STEXI
585 @item -hda @var{file}
586 @itemx -hdb @var{file}
587 @itemx -hdc @var{file}
588 @itemx -hdd @var{file}
589 @findex -hda
590 @findex -hdb
591 @findex -hdc
592 @findex -hdd
593 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
594 ETEXI
596 DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
597 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
598 QEMU_ARCH_ALL)
599 STEXI
600 @item -cdrom @var{file}
601 @findex -cdrom
602 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
603 @option{-cdrom} at the same time). You can use the host CD-ROM by
604 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
605 ETEXI
607 DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
608 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
609 " [,cache.direct=on|off][,cache.no-flush=on|off]\n"
610 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
611 " [,driver specific parameters...]\n"
612 " configure a block backend\n", QEMU_ARCH_ALL)
613 STEXI
614 @item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
615 @findex -blockdev
617 Define a new block driver node. Some of the options apply to all block drivers,
618 other options are only accepted for a specific block driver. See below for a
619 list of generic options and options for the most common block drivers.
621 Options that expect a reference to another node (e.g. @code{file}) can be
622 given in two ways. Either you specify the node name of an already existing node
623 (file=@var{node-name}), or you define a new node inline, adding options
624 for the referenced node after a dot (file.filename=@var{path},file.aio=native).
626 A block driver node created with @option{-blockdev} can be used for a guest
627 device by specifying its node name for the @code{drive} property in a
628 @option{-device} argument that defines a block device.
630 @table @option
631 @item Valid options for any block driver node:
633 @table @code
634 @item driver
635 Specifies the block driver to use for the given node.
636 @item node-name
637 This defines the name of the block driver node by which it will be referenced
638 later. The name must be unique, i.e. it must not match the name of a different
639 block driver node, or (if you use @option{-drive} as well) the ID of a drive.
641 If no node name is specified, it is automatically generated. The generated node
642 name is not intended to be predictable and changes between QEMU invocations.
643 For the top level, an explicit node name must be specified.
644 @item read-only
645 Open the node read-only. Guest write attempts will fail.
646 @item cache.direct
647 The host page cache can be avoided with @option{cache.direct=on}. This will
648 attempt to do disk IO directly to the guest's memory. QEMU may still perform an
649 internal copy of the data.
650 @item cache.no-flush
651 In case you don't care about data integrity over host failures, you can use
652 @option{cache.no-flush=on}. This option tells QEMU that it never needs to write
653 any data to the disk but can instead keep things in cache. If anything goes
654 wrong, like your host losing power, the disk storage getting disconnected
655 accidentally, etc. your image will most probably be rendered unusable.
656 @item discard=@var{discard}
657 @var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls
658 whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
659 ignored or passed to the filesystem. Some machine types may not support
660 discard requests.
661 @item detect-zeroes=@var{detect-zeroes}
662 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
663 conversion of plain zero writes by the OS to driver specific optimized
664 zero write commands. You may even choose "unmap" if @var{discard} is set
665 to "unmap" to allow a zero write to be converted to an @code{unmap} operation.
666 @end table
668 @item Driver-specific options for @code{file}
670 This is the protocol-level block driver for accessing regular files.
672 @table @code
673 @item filename
674 The path to the image file in the local filesystem
675 @item aio
676 Specifies the AIO backend (threads/native, default: threads)
677 @end table
678 Example:
679 @example
680 -blockdev driver=file,node-name=disk,filename=disk.img
681 @end example
683 @item Driver-specific options for @code{raw}
685 This is the image format block driver for raw images. It is usually
686 stacked on top of a protocol level block driver such as @code{file}.
688 @table @code
689 @item file
690 Reference to or definition of the data source block driver node
691 (e.g. a @code{file} driver node)
692 @end table
693 Example 1:
694 @example
695 -blockdev driver=file,node-name=disk_file,filename=disk.img
696 -blockdev driver=raw,node-name=disk,file=disk_file
697 @end example
698 Example 2:
699 @example
700 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
701 @end example
703 @item Driver-specific options for @code{qcow2}
705 This is the image format block driver for qcow2 images. It is usually
706 stacked on top of a protocol level block driver such as @code{file}.
708 @table @code
709 @item file
710 Reference to or definition of the data source block driver node
711 (e.g. a @code{file} driver node)
713 @item backing
714 Reference to or definition of the backing file block device (default is taken
715 from the image file). It is allowed to pass an empty string here in order to
716 disable the default backing file.
718 @item lazy-refcounts
719 Whether to enable the lazy refcounts feature (on/off; default is taken from the
720 image file)
722 @item cache-size
723 The maximum total size of the L2 table and refcount block caches in bytes
724 (default: 1048576 bytes or 8 clusters, whichever is larger)
726 @item l2-cache-size
727 The maximum size of the L2 table cache in bytes
728 (default: 4/5 of the total cache size)
730 @item refcount-cache-size
731 The maximum size of the refcount block cache in bytes
732 (default: 1/5 of the total cache size)
734 @item cache-clean-interval
735 Clean unused entries in the L2 and refcount caches. The interval is in seconds.
736 The default value is 0 and it disables this feature.
738 @item pass-discard-request
739 Whether discard requests to the qcow2 device should be forwarded to the data
740 source (on/off; default: on if discard=unmap is specified, off otherwise)
742 @item pass-discard-snapshot
743 Whether discard requests for the data source should be issued when a snapshot
744 operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
745 default: on)
747 @item pass-discard-other
748 Whether discard requests for the data source should be issued on other
749 occasions where a cluster gets freed (on/off; default: off)
751 @item overlap-check
752 Which overlap checks to perform for writes to the image
753 (none/constant/cached/all; default: cached). For details or finer
754 granularity control refer to the QAPI documentation of @code{blockdev-add}.
755 @end table
757 Example 1:
758 @example
759 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
760 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
761 @end example
762 Example 2:
763 @example
764 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
765 @end example
767 @item Driver-specific options for other drivers
768 Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
770 @end table
772 ETEXI
774 DEF("drive", HAS_ARG, QEMU_OPTION_drive,
775 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
776 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
777 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
778 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
779 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
780 " [,readonly=on|off][,copy-on-read=on|off]\n"
781 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
782 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
783 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
784 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
785 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
786 " [[,iops_size=is]]\n"
787 " [[,group=g]]\n"
788 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
789 STEXI
790 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
791 @findex -drive
793 Define a new drive. This includes creating a block driver node (the backend) as
794 well as a guest device, and is mostly a shortcut for defining the corresponding
795 @option{-blockdev} and @option{-device} options.
797 @option{-drive} accepts all options that are accepted by @option{-blockdev}. In
798 addition, it knows the following options:
800 @table @option
801 @item file=@var{file}
802 This option defines which disk image (@pxref{disk_images}) to use with
803 this drive. If the filename contains comma, you must double it
804 (for instance, "file=my,,file" to use file "my,file").
806 Special files such as iSCSI devices can be specified using protocol
807 specific URLs. See the section for "Device URL Syntax" for more information.
808 @item if=@var{interface}
809 This option defines on which type on interface the drive is connected.
810 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
811 @item bus=@var{bus},unit=@var{unit}
812 These options define where is connected the drive by defining the bus number and
813 the unit id.
814 @item index=@var{index}
815 This option defines where is connected the drive by using an index in the list
816 of available connectors of a given interface type.
817 @item media=@var{media}
818 This option defines the type of the media: disk or cdrom.
819 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
820 These options have the same definition as they have in @option{-hdachs}.
821 @item snapshot=@var{snapshot}
822 @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
823 (see @option{-snapshot}).
824 @item cache=@var{cache}
825 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
826 and controls how the host cache is used to access block data. This is a
827 shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
828 options (as in @option{-blockdev}), and additionally @option{cache.writeback},
829 which provides a default for the @option{write-cache} option of block guest
830 devices (as in @option{-device}). The modes correspond to the following
831 settings:
833 @c Our texi2pod.pl script doesn't support @multitable, so fall back to using
834 @c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
835 @c and the HTML output.
836 @example
837 @ │ cache.writeback cache.direct cache.no-flush
838 ─────────────┼─────────────────────────────────────────────────
839 writeback │ on off off
840 none │ on on off
841 writethrough │ off off off
842 directsync │ off on off
843 unsafe │ on off on
844 @end example
846 The default mode is @option{cache=writeback}.
848 @item aio=@var{aio}
849 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
850 @item format=@var{format}
851 Specify which disk @var{format} will be used rather than detecting
852 the format. Can be used to specify format=raw to avoid interpreting
853 an untrusted format header.
854 @item serial=@var{serial}
855 This option specifies the serial number to assign to the device.
856 @item addr=@var{addr}
857 Specify the controller's PCI address (if=virtio only).
858 @item werror=@var{action},rerror=@var{action}
859 Specify which @var{action} to take on write and read errors. Valid actions are:
860 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
861 "report" (report the error to the guest), "enospc" (pause QEMU only if the
862 host disk is full; report the error to the guest otherwise).
863 The default setting is @option{werror=enospc} and @option{rerror=report}.
864 @item copy-on-read=@var{copy-on-read}
865 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
866 file sectors into the image file.
867 @item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
868 Specify bandwidth throttling limits in bytes per second, either for all request
869 types or for reads or writes only. Small values can lead to timeouts or hangs
870 inside the guest. A safe minimum for disks is 2 MB/s.
871 @item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
872 Specify bursts in bytes per second, either for all request types or for reads
873 or writes only. Bursts allow the guest I/O to spike above the limit
874 temporarily.
875 @item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
876 Specify request rate limits in requests per second, either for all request
877 types or for reads or writes only.
878 @item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
879 Specify bursts in requests per second, either for all request types or for reads
880 or writes only. Bursts allow the guest I/O to spike above the limit
881 temporarily.
882 @item iops_size=@var{is}
883 Let every @var{is} bytes of a request count as a new request for iops
884 throttling purposes. Use this option to prevent guests from circumventing iops
885 limits by sending fewer but larger requests.
886 @item group=@var{g}
887 Join a throttling quota group with given name @var{g}. All drives that are
888 members of the same group are accounted for together. Use this option to
889 prevent guests from circumventing throttling limits by using many small disks
890 instead of a single larger disk.
891 @end table
893 By default, the @option{cache.writeback=on} mode is used. It will report data
894 writes as completed as soon as the data is present in the host page cache.
895 This is safe as long as your guest OS makes sure to correctly flush disk caches
896 where needed. If your guest OS does not handle volatile disk write caches
897 correctly and your host crashes or loses power, then the guest may experience
898 data corruption.
900 For such guests, you should consider using @option{cache.writeback=off}. This
901 means that the host page cache will be used to read and write data, but write
902 notification will be sent to the guest only after QEMU has made sure to flush
903 each write to the disk. Be aware that this has a major impact on performance.
905 When using the @option{-snapshot} option, unsafe caching is always used.
907 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
908 useful when the backing file is over a slow network. By default copy-on-read
909 is off.
911 Instead of @option{-cdrom} you can use:
912 @example
913 qemu-system-i386 -drive file=file,index=2,media=cdrom
914 @end example
916 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
917 use:
918 @example
919 qemu-system-i386 -drive file=file,index=0,media=disk
920 qemu-system-i386 -drive file=file,index=1,media=disk
921 qemu-system-i386 -drive file=file,index=2,media=disk
922 qemu-system-i386 -drive file=file,index=3,media=disk
923 @end example
925 You can open an image using pre-opened file descriptors from an fd set:
926 @example
927 qemu-system-i386
928 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
929 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
930 -drive file=/dev/fdset/2,index=0,media=disk
931 @end example
933 You can connect a CDROM to the slave of ide0:
934 @example
935 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
936 @end example
938 If you don't specify the "file=" argument, you define an empty drive:
939 @example
940 qemu-system-i386 -drive if=ide,index=1,media=cdrom
941 @end example
943 Instead of @option{-fda}, @option{-fdb}, you can use:
944 @example
945 qemu-system-i386 -drive file=file,index=0,if=floppy
946 qemu-system-i386 -drive file=file,index=1,if=floppy
947 @end example
949 By default, @var{interface} is "ide" and @var{index} is automatically
950 incremented:
951 @example
952 qemu-system-i386 -drive file=a -drive file=b"
953 @end example
954 is interpreted like:
955 @example
956 qemu-system-i386 -hda a -hdb b
957 @end example
958 ETEXI
960 DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
961 "-mtdblock file use 'file' as on-board Flash memory image\n",
962 QEMU_ARCH_ALL)
963 STEXI
964 @item -mtdblock @var{file}
965 @findex -mtdblock
966 Use @var{file} as on-board Flash memory image.
967 ETEXI
969 DEF("sd", HAS_ARG, QEMU_OPTION_sd,
970 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
971 STEXI
972 @item -sd @var{file}
973 @findex -sd
974 Use @var{file} as SecureDigital card image.
975 ETEXI
977 DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
978 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
979 STEXI
980 @item -pflash @var{file}
981 @findex -pflash
982 Use @var{file} as a parallel flash image.
983 ETEXI
985 DEF("snapshot", 0, QEMU_OPTION_snapshot,
986 "-snapshot write to temporary files instead of disk image files\n",
987 QEMU_ARCH_ALL)
988 STEXI
989 @item -snapshot
990 @findex -snapshot
991 Write to temporary files instead of disk image files. In this case,
992 the raw disk image you use is not written back. You can however force
993 the write back by pressing @key{C-a s} (@pxref{disk_images}).
994 ETEXI
996 DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
997 "-hdachs c,h,s[,t]\n" \
998 " force hard disk 0 physical geometry and the optional BIOS\n" \
999 " translation (t=none or lba) (usually QEMU can guess them)\n",
1000 QEMU_ARCH_ALL)
1001 STEXI
1002 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
1003 @findex -hdachs
1004 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
1005 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
1006 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
1007 all those parameters. This option is deprecated, please use
1008 @code{-device ide-hd,cyls=c,heads=h,secs=s,...} instead.
1009 ETEXI
1011 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
1012 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1013 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n"
1014 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1015 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1016 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1017 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1018 " [[,throttling.iops-size=is]]\n",
1019 QEMU_ARCH_ALL)
1021 STEXI
1023 @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}]
1024 @findex -fsdev
1025 Define a new file system device. Valid options are:
1026 @table @option
1027 @item @var{fsdriver}
1028 This option specifies the fs driver backend to use.
1029 Currently "local", "handle" and "proxy" file system drivers are supported.
1030 @item id=@var{id}
1031 Specifies identifier for this device
1032 @item path=@var{path}
1033 Specifies the export path for the file system device. Files under
1034 this path will be available to the 9p client on the guest.
1035 @item security_model=@var{security_model}
1036 Specifies the security model to be used for this export path.
1037 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1038 In "passthrough" security model, files are stored using the same
1039 credentials as they are created on the guest. This requires QEMU
1040 to run as root. In "mapped-xattr" security model, some of the file
1041 attributes like uid, gid, mode bits and link target are stored as
1042 file attributes. For "mapped-file" these attributes are stored in the
1043 hidden .virtfs_metadata directory. Directories exported by this security model cannot
1044 interact with other unix tools. "none" security model is same as
1045 passthrough except the sever won't report failures if it fails to
1046 set file attributes like ownership. Security model is mandatory
1047 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
1048 security model as a parameter.
1049 @item writeout=@var{writeout}
1050 This is an optional argument. The only supported value is "immediate".
1051 This means that host page cache will be used to read and write data but
1052 write notification will be sent to the guest only when the data has been
1053 reported as written by the storage subsystem.
1054 @item readonly
1055 Enables exporting 9p share as a readonly mount for guests. By default
1056 read-write access is given.
1057 @item socket=@var{socket}
1058 Enables proxy filesystem driver to use passed socket file for communicating
1059 with virtfs-proxy-helper
1060 @item sock_fd=@var{sock_fd}
1061 Enables proxy filesystem driver to use passed socket descriptor for
1062 communicating with virtfs-proxy-helper. Usually a helper like libvirt
1063 will create socketpair and pass one of the fds as sock_fd
1064 @end table
1066 -fsdev option is used along with -device driver "virtio-9p-pci".
1067 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
1068 Options for virtio-9p-pci driver are:
1069 @table @option
1070 @item fsdev=@var{id}
1071 Specifies the id value specified along with -fsdev option
1072 @item mount_tag=@var{mount_tag}
1073 Specifies the tag name to be used by the guest to mount this export point
1074 @end table
1076 ETEXI
1078 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
1079 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1080 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
1081 QEMU_ARCH_ALL)
1083 STEXI
1085 @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}]
1086 @findex -virtfs
1088 The general form of a Virtual File system pass-through options are:
1089 @table @option
1090 @item @var{fsdriver}
1091 This option specifies the fs driver backend to use.
1092 Currently "local", "handle" and "proxy" file system drivers are supported.
1093 @item id=@var{id}
1094 Specifies identifier for this device
1095 @item path=@var{path}
1096 Specifies the export path for the file system device. Files under
1097 this path will be available to the 9p client on the guest.
1098 @item security_model=@var{security_model}
1099 Specifies the security model to be used for this export path.
1100 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1101 In "passthrough" security model, files are stored using the same
1102 credentials as they are created on the guest. This requires QEMU
1103 to run as root. In "mapped-xattr" security model, some of the file
1104 attributes like uid, gid, mode bits and link target are stored as
1105 file attributes. For "mapped-file" these attributes are stored in the
1106 hidden .virtfs_metadata directory. Directories exported by this security model cannot
1107 interact with other unix tools. "none" security model is same as
1108 passthrough except the sever won't report failures if it fails to
1109 set file attributes like ownership. Security model is mandatory only
1110 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
1111 model as a parameter.
1112 @item writeout=@var{writeout}
1113 This is an optional argument. The only supported value is "immediate".
1114 This means that host page cache will be used to read and write data but
1115 write notification will be sent to the guest only when the data has been
1116 reported as written by the storage subsystem.
1117 @item readonly
1118 Enables exporting 9p share as a readonly mount for guests. By default
1119 read-write access is given.
1120 @item socket=@var{socket}
1121 Enables proxy filesystem driver to use passed socket file for
1122 communicating with virtfs-proxy-helper. Usually a helper like libvirt
1123 will create socketpair and pass one of the fds as sock_fd
1124 @item sock_fd
1125 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
1126 descriptor for interfacing with virtfs-proxy-helper
1127 @end table
1128 ETEXI
1130 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
1131 "-virtfs_synth Create synthetic file system image\n",
1132 QEMU_ARCH_ALL)
1133 STEXI
1134 @item -virtfs_synth
1135 @findex -virtfs_synth
1136 Create synthetic file system image
1137 ETEXI
1139 STEXI
1140 @end table
1141 ETEXI
1142 DEFHEADING()
1144 DEFHEADING(USB options)
1145 STEXI
1146 @table @option
1147 ETEXI
1149 DEF("usb", 0, QEMU_OPTION_usb,
1150 "-usb enable the USB driver (if it is not used by default yet)\n",
1151 QEMU_ARCH_ALL)
1152 STEXI
1153 @item -usb
1154 @findex -usb
1155 Enable the USB driver (if it is not used by default yet).
1156 ETEXI
1158 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1159 "-usbdevice name add the host or guest USB device 'name'\n",
1160 QEMU_ARCH_ALL)
1161 STEXI
1163 @item -usbdevice @var{devname}
1164 @findex -usbdevice
1165 Add the USB device @var{devname}. Note that this option is deprecated,
1166 please use @code{-device usb-...} instead. @xref{usb_devices}.
1168 @table @option
1170 @item mouse
1171 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1173 @item tablet
1174 Pointer device that uses absolute coordinates (like a touchscreen). This
1175 means QEMU is able to report the mouse position without having to grab the
1176 mouse. Also overrides the PS/2 mouse emulation when activated.
1178 @item disk:[format=@var{format}]:@var{file}
1179 Mass storage device based on file. The optional @var{format} argument
1180 will be used rather than detecting the format. Can be used to specify
1181 @code{format=raw} to avoid interpreting an untrusted format header.
1183 @item host:@var{bus}.@var{addr}
1184 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
1186 @item host:@var{vendor_id}:@var{product_id}
1187 Pass through the host device identified by @var{vendor_id}:@var{product_id}
1188 (Linux only).
1190 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
1191 Serial converter to host character device @var{dev}, see @code{-serial} for the
1192 available devices.
1194 @item braille
1195 Braille device. This will use BrlAPI to display the braille output on a real
1196 or fake device.
1198 @item net:@var{options}
1199 Network adapter that supports CDC ethernet and RNDIS protocols.
1201 @end table
1202 ETEXI
1204 STEXI
1205 @end table
1206 ETEXI
1207 DEFHEADING()
1209 DEFHEADING(Display options)
1210 STEXI
1211 @table @option
1212 ETEXI
1214 DEF("display", HAS_ARG, QEMU_OPTION_display,
1215 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1216 " [,window_close=on|off][,gl=on|off]\n"
1217 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1218 "-display vnc=<display>[,<optargs>]\n"
1219 "-display curses\n"
1220 "-display none"
1221 " select display type\n"
1222 "The default display is equivalent to\n"
1223 #if defined(CONFIG_GTK)
1224 "\t\"-display gtk\"\n"
1225 #elif defined(CONFIG_SDL)
1226 "\t\"-display sdl\"\n"
1227 #elif defined(CONFIG_COCOA)
1228 "\t\"-display cocoa\"\n"
1229 #elif defined(CONFIG_VNC)
1230 "\t\"-vnc localhost:0,to=99,id=default\"\n"
1231 #else
1232 "\t\"-display none\"\n"
1233 #endif
1234 , QEMU_ARCH_ALL)
1235 STEXI
1236 @item -display @var{type}
1237 @findex -display
1238 Select type of display to use. This option is a replacement for the
1239 old style -sdl/-curses/... options. Valid values for @var{type} are
1240 @table @option
1241 @item sdl
1242 Display video output via SDL (usually in a separate graphics
1243 window; see the SDL documentation for other possibilities).
1244 @item curses
1245 Display video output via curses. For graphics device models which
1246 support a text mode, QEMU can display this output using a
1247 curses/ncurses interface. Nothing is displayed when the graphics
1248 device is in graphical mode or if the graphics device does not support
1249 a text mode. Generally only the VGA device models support text mode.
1250 @item none
1251 Do not display video output. The guest will still see an emulated
1252 graphics card, but its output will not be displayed to the QEMU
1253 user. This option differs from the -nographic option in that it
1254 only affects what is done with video output; -nographic also changes
1255 the destination of the serial and parallel port data.
1256 @item gtk
1257 Display video output in a GTK window. This interface provides drop-down
1258 menus and other UI elements to configure and control the VM during
1259 runtime.
1260 @item vnc
1261 Start a VNC server on display <arg>
1262 @end table
1263 ETEXI
1265 DEF("nographic", 0, QEMU_OPTION_nographic,
1266 "-nographic disable graphical output and redirect serial I/Os to console\n",
1267 QEMU_ARCH_ALL)
1268 STEXI
1269 @item -nographic
1270 @findex -nographic
1271 Normally, if QEMU is compiled with graphical window support, it displays
1272 output such as guest graphics, guest console, and the QEMU monitor in a
1273 window. With this option, you can totally disable graphical output so
1274 that QEMU is a simple command line application. The emulated serial port
1275 is redirected on the console and muxed with the monitor (unless
1276 redirected elsewhere explicitly). Therefore, you can still use QEMU to
1277 debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1278 switching between the console and monitor.
1279 ETEXI
1281 DEF("curses", 0, QEMU_OPTION_curses,
1282 "-curses shorthand for -display curses\n",
1283 QEMU_ARCH_ALL)
1284 STEXI
1285 @item -curses
1286 @findex -curses
1287 Normally, if QEMU is compiled with graphical window support, it displays
1288 output such as guest graphics, guest console, and the QEMU monitor in a
1289 window. With this option, QEMU can display the VGA output when in text
1290 mode using a curses/ncurses interface. Nothing is displayed in graphical
1291 mode.
1292 ETEXI
1294 DEF("no-frame", 0, QEMU_OPTION_no_frame,
1295 "-no-frame open SDL window without a frame and window decorations\n",
1296 QEMU_ARCH_ALL)
1297 STEXI
1298 @item -no-frame
1299 @findex -no-frame
1300 Do not use decorations for SDL windows and start them using the whole
1301 available screen space. This makes the using QEMU in a dedicated desktop
1302 workspace more convenient.
1303 ETEXI
1305 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1306 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1307 QEMU_ARCH_ALL)
1308 STEXI
1309 @item -alt-grab
1310 @findex -alt-grab
1311 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1312 affects the special keys (for fullscreen, monitor-mode switching, etc).
1313 ETEXI
1315 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1316 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1317 QEMU_ARCH_ALL)
1318 STEXI
1319 @item -ctrl-grab
1320 @findex -ctrl-grab
1321 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1322 affects the special keys (for fullscreen, monitor-mode switching, etc).
1323 ETEXI
1325 DEF("no-quit", 0, QEMU_OPTION_no_quit,
1326 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
1327 STEXI
1328 @item -no-quit
1329 @findex -no-quit
1330 Disable SDL window close capability.
1331 ETEXI
1333 DEF("sdl", 0, QEMU_OPTION_sdl,
1334 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL)
1335 STEXI
1336 @item -sdl
1337 @findex -sdl
1338 Enable SDL.
1339 ETEXI
1341 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1342 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1343 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1344 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1345 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1346 " [,tls-ciphers=<list>]\n"
1347 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1348 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1349 " [,sasl][,password=<secret>][,disable-ticketing]\n"
1350 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1351 " [,jpeg-wan-compression=[auto|never|always]]\n"
1352 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
1353 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1354 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1355 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1356 " [,gl=[on|off]][,rendernode=<file>]\n"
1357 " enable spice\n"
1358 " at least one of {port, tls-port} is mandatory\n",
1359 QEMU_ARCH_ALL)
1360 STEXI
1361 @item -spice @var{option}[,@var{option}[,...]]
1362 @findex -spice
1363 Enable the spice remote desktop protocol. Valid options are
1365 @table @option
1367 @item port=<nr>
1368 Set the TCP port spice is listening on for plaintext channels.
1370 @item addr=<addr>
1371 Set the IP address spice is listening on. Default is any address.
1373 @item ipv4
1374 @itemx ipv6
1375 @itemx unix
1376 Force using the specified IP version.
1378 @item password=<secret>
1379 Set the password you need to authenticate.
1381 @item sasl
1382 Require that the client use SASL to authenticate with the spice.
1383 The exact choice of authentication method used is controlled from the
1384 system / user's SASL configuration file for the 'qemu' service. This
1385 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1386 unprivileged user, an environment variable SASL_CONF_PATH can be used
1387 to make it search alternate locations for the service config.
1388 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1389 it is recommended that SASL always be combined with the 'tls' and
1390 'x509' settings to enable use of SSL and server certificates. This
1391 ensures a data encryption preventing compromise of authentication
1392 credentials.
1394 @item disable-ticketing
1395 Allow client connects without authentication.
1397 @item disable-copy-paste
1398 Disable copy paste between the client and the guest.
1400 @item disable-agent-file-xfer
1401 Disable spice-vdagent based file-xfer between the client and the guest.
1403 @item tls-port=<nr>
1404 Set the TCP port spice is listening on for encrypted channels.
1406 @item x509-dir=<dir>
1407 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1409 @item x509-key-file=<file>
1410 @itemx x509-key-password=<file>
1411 @itemx x509-cert-file=<file>
1412 @itemx x509-cacert-file=<file>
1413 @itemx x509-dh-key-file=<file>
1414 The x509 file names can also be configured individually.
1416 @item tls-ciphers=<list>
1417 Specify which ciphers to use.
1419 @item tls-channel=[main|display|cursor|inputs|record|playback]
1420 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1421 Force specific channel to be used with or without TLS encryption. The
1422 options can be specified multiple times to configure multiple
1423 channels. The special name "default" can be used to set the default
1424 mode. For channels which are not explicitly forced into one mode the
1425 spice client is allowed to pick tls/plaintext as he pleases.
1427 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1428 Configure image compression (lossless).
1429 Default is auto_glz.
1431 @item jpeg-wan-compression=[auto|never|always]
1432 @itemx zlib-glz-wan-compression=[auto|never|always]
1433 Configure wan image compression (lossy for slow links).
1434 Default is auto.
1436 @item streaming-video=[off|all|filter]
1437 Configure video stream detection. Default is off.
1439 @item agent-mouse=[on|off]
1440 Enable/disable passing mouse events via vdagent. Default is on.
1442 @item playback-compression=[on|off]
1443 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1445 @item seamless-migration=[on|off]
1446 Enable/disable spice seamless migration. Default is off.
1448 @item gl=[on|off]
1449 Enable/disable OpenGL context. Default is off.
1451 @item rendernode=<file>
1452 DRM render node for OpenGL rendering. If not specified, it will pick
1453 the first available. (Since 2.9)
1455 @end table
1456 ETEXI
1458 DEF("portrait", 0, QEMU_OPTION_portrait,
1459 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1460 QEMU_ARCH_ALL)
1461 STEXI
1462 @item -portrait
1463 @findex -portrait
1464 Rotate graphical output 90 deg left (only PXA LCD).
1465 ETEXI
1467 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1468 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1469 QEMU_ARCH_ALL)
1470 STEXI
1471 @item -rotate @var{deg}
1472 @findex -rotate
1473 Rotate graphical output some deg left (only PXA LCD).
1474 ETEXI
1476 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1477 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1478 " select video card type\n", QEMU_ARCH_ALL)
1479 STEXI
1480 @item -vga @var{type}
1481 @findex -vga
1482 Select type of VGA card to emulate. Valid values for @var{type} are
1483 @table @option
1484 @item cirrus
1485 Cirrus Logic GD5446 Video card. All Windows versions starting from
1486 Windows 95 should recognize and use this graphic card. For optimal
1487 performances, use 16 bit color depth in the guest and the host OS.
1488 (This card was the default before QEMU 2.2)
1489 @item std
1490 Standard VGA card with Bochs VBE extensions. If your guest OS
1491 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1492 to use high resolution modes (>= 1280x1024x16) then you should use
1493 this option. (This card is the default since QEMU 2.2)
1494 @item vmware
1495 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1496 recent XFree86/XOrg server or Windows guest with a driver for this
1497 card.
1498 @item qxl
1499 QXL paravirtual graphic card. It is VGA compatible (including VESA
1500 2.0 VBE support). Works best with qxl guest drivers installed though.
1501 Recommended choice when using the spice protocol.
1502 @item tcx
1503 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1504 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1505 fixed resolution of 1024x768.
1506 @item cg3
1507 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1508 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1509 resolutions aimed at people wishing to run older Solaris versions.
1510 @item virtio
1511 Virtio VGA card.
1512 @item none
1513 Disable VGA card.
1514 @end table
1515 ETEXI
1517 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1518 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1519 STEXI
1520 @item -full-screen
1521 @findex -full-screen
1522 Start in full screen.
1523 ETEXI
1525 DEF("g", 1, QEMU_OPTION_g ,
1526 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1527 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1528 STEXI
1529 @item -g @var{width}x@var{height}[x@var{depth}]
1530 @findex -g
1531 Set the initial graphical resolution and depth (PPC, SPARC only).
1532 ETEXI
1534 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1535 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1536 STEXI
1537 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1538 @findex -vnc
1539 Normally, if QEMU is compiled with graphical window support, it displays
1540 output such as guest graphics, guest console, and the QEMU monitor in a
1541 window. With this option, you can have QEMU listen on VNC display
1542 @var{display} and redirect the VGA display over the VNC session. It is
1543 very useful to enable the usb tablet device when using this option
1544 (option @option{-device usb-tablet}). When using the VNC display, you
1545 must use the @option{-k} parameter to set the keyboard layout if you are
1546 not using en-us. Valid syntax for the @var{display} is
1548 @table @option
1550 @item to=@var{L}
1552 With this option, QEMU will try next available VNC @var{display}s, until the
1553 number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1554 available, e.g. port 5900+@var{display} is already used by another
1555 application. By default, to=0.
1557 @item @var{host}:@var{d}
1559 TCP connections will only be allowed from @var{host} on display @var{d}.
1560 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1561 be omitted in which case the server will accept connections from any host.
1563 @item unix:@var{path}
1565 Connections will be allowed over UNIX domain sockets where @var{path} is the
1566 location of a unix socket to listen for connections on.
1568 @item none
1570 VNC is initialized but not started. The monitor @code{change} command
1571 can be used to later start the VNC server.
1573 @end table
1575 Following the @var{display} value there may be one or more @var{option} flags
1576 separated by commas. Valid options are
1578 @table @option
1580 @item reverse
1582 Connect to a listening VNC client via a ``reverse'' connection. The
1583 client is specified by the @var{display}. For reverse network
1584 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1585 is a TCP port number, not a display number.
1587 @item websocket
1589 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1590 If a bare @var{websocket} option is given, the Websocket port is
1591 5700+@var{display}. An alternative port can be specified with the
1592 syntax @code{websocket}=@var{port}.
1594 If @var{host} is specified connections will only be allowed from this host.
1595 It is possible to control the websocket listen address independently, using
1596 the syntax @code{websocket}=@var{host}:@var{port}.
1598 If no TLS credentials are provided, the websocket connection runs in
1599 unencrypted mode. If TLS credentials are provided, the websocket connection
1600 requires encrypted client connections.
1602 @item password
1604 Require that password based authentication is used for client connections.
1606 The password must be set separately using the @code{set_password} command in
1607 the @ref{pcsys_monitor}. The syntax to change your password is:
1608 @code{set_password <protocol> <password>} where <protocol> could be either
1609 "vnc" or "spice".
1611 If you would like to change <protocol> password expiration, you should use
1612 @code{expire_password <protocol> <expiration-time>} where expiration time could
1613 be one of the following options: now, never, +seconds or UNIX time of
1614 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1615 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1616 date and time).
1618 You can also use keywords "now" or "never" for the expiration time to
1619 allow <protocol> password to expire immediately or never expire.
1621 @item tls-creds=@var{ID}
1623 Provides the ID of a set of TLS credentials to use to secure the
1624 VNC server. They will apply to both the normal VNC server socket
1625 and the websocket socket (if enabled). Setting TLS credentials
1626 will cause the VNC server socket to enable the VeNCrypt auth
1627 mechanism. The credentials should have been previously created
1628 using the @option{-object tls-creds} argument.
1630 The @option{tls-creds} parameter obsoletes the @option{tls},
1631 @option{x509}, and @option{x509verify} options, and as such
1632 it is not permitted to set both new and old type options at
1633 the same time.
1635 @item tls
1637 Require that client use TLS when communicating with the VNC server. This
1638 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1639 attack. It is recommended that this option be combined with either the
1640 @option{x509} or @option{x509verify} options.
1642 This option is now deprecated in favor of using the @option{tls-creds}
1643 argument.
1645 @item x509=@var{/path/to/certificate/dir}
1647 Valid if @option{tls} is specified. Require that x509 credentials are used
1648 for negotiating the TLS session. The server will send its x509 certificate
1649 to the client. It is recommended that a password be set on the VNC server
1650 to provide authentication of the client when this is used. The path following
1651 this option specifies where the x509 certificates are to be loaded from.
1652 See the @ref{vnc_security} section for details on generating certificates.
1654 This option is now deprecated in favour of using the @option{tls-creds}
1655 argument.
1657 @item x509verify=@var{/path/to/certificate/dir}
1659 Valid if @option{tls} is specified. Require that x509 credentials are used
1660 for negotiating the TLS session. The server will send its x509 certificate
1661 to the client, and request that the client send its own x509 certificate.
1662 The server will validate the client's certificate against the CA certificate,
1663 and reject clients when validation fails. If the certificate authority is
1664 trusted, this is a sufficient authentication mechanism. You may still wish
1665 to set a password on the VNC server as a second authentication layer. The
1666 path following this option specifies where the x509 certificates are to
1667 be loaded from. See the @ref{vnc_security} section for details on generating
1668 certificates.
1670 This option is now deprecated in favour of using the @option{tls-creds}
1671 argument.
1673 @item sasl
1675 Require that the client use SASL to authenticate with the VNC server.
1676 The exact choice of authentication method used is controlled from the
1677 system / user's SASL configuration file for the 'qemu' service. This
1678 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1679 unprivileged user, an environment variable SASL_CONF_PATH can be used
1680 to make it search alternate locations for the service config.
1681 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1682 it is recommended that SASL always be combined with the 'tls' and
1683 'x509' settings to enable use of SSL and server certificates. This
1684 ensures a data encryption preventing compromise of authentication
1685 credentials. See the @ref{vnc_security} section for details on using
1686 SASL authentication.
1688 @item acl
1690 Turn on access control lists for checking of the x509 client certificate
1691 and SASL party. For x509 certs, the ACL check is made against the
1692 certificate's distinguished name. This is something that looks like
1693 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1694 made against the username, which depending on the SASL plugin, may
1695 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1696 When the @option{acl} flag is set, the initial access list will be
1697 empty, with a @code{deny} policy. Thus no one will be allowed to
1698 use the VNC server until the ACLs have been loaded. This can be
1699 achieved using the @code{acl} monitor command.
1701 @item lossy
1703 Enable lossy compression methods (gradient, JPEG, ...). If this
1704 option is set, VNC client may receive lossy framebuffer updates
1705 depending on its encoding settings. Enabling this option can save
1706 a lot of bandwidth at the expense of quality.
1708 @item non-adaptive
1710 Disable adaptive encodings. Adaptive encodings are enabled by default.
1711 An adaptive encoding will try to detect frequently updated screen regions,
1712 and send updates in these regions using a lossy encoding (like JPEG).
1713 This can be really helpful to save bandwidth when playing videos. Disabling
1714 adaptive encodings restores the original static behavior of encodings
1715 like Tight.
1717 @item share=[allow-exclusive|force-shared|ignore]
1719 Set display sharing policy. 'allow-exclusive' allows clients to ask
1720 for exclusive access. As suggested by the rfb spec this is
1721 implemented by dropping other connections. Connecting multiple
1722 clients in parallel requires all clients asking for a shared session
1723 (vncviewer: -shared switch). This is the default. 'force-shared'
1724 disables exclusive client access. Useful for shared desktop sessions,
1725 where you don't want someone forgetting specify -shared disconnect
1726 everybody else. 'ignore' completely ignores the shared flag and
1727 allows everybody connect unconditionally. Doesn't conform to the rfb
1728 spec but is traditional QEMU behavior.
1730 @item key-delay-ms
1732 Set keyboard delay, for key down and key up events, in milliseconds.
1733 Default is 1. Keyboards are low-bandwidth devices, so this slowdown
1734 can help the device and guest to keep up and not lose events in case
1735 events are arriving in bulk. Possible causes for the latter are flaky
1736 network connections, or scripts for automated testing.
1738 @end table
1739 ETEXI
1741 STEXI
1742 @end table
1743 ETEXI
1744 ARCHHEADING(, QEMU_ARCH_I386)
1746 ARCHHEADING(i386 target only, QEMU_ARCH_I386)
1747 STEXI
1748 @table @option
1749 ETEXI
1751 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1752 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1753 QEMU_ARCH_I386)
1754 STEXI
1755 @item -win2k-hack
1756 @findex -win2k-hack
1757 Use it when installing Windows 2000 to avoid a disk full bug. After
1758 Windows 2000 is installed, you no longer need this option (this option
1759 slows down the IDE transfers).
1760 ETEXI
1762 HXCOMM Deprecated by -rtc
1763 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1765 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1766 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1767 QEMU_ARCH_I386)
1768 STEXI
1769 @item -no-fd-bootchk
1770 @findex -no-fd-bootchk
1771 Disable boot signature checking for floppy disks in BIOS. May
1772 be needed to boot from old floppy disks.
1773 ETEXI
1775 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1776 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1777 STEXI
1778 @item -no-acpi
1779 @findex -no-acpi
1780 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1781 it if your guest OS complains about ACPI problems (PC target machine
1782 only).
1783 ETEXI
1785 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1786 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1787 STEXI
1788 @item -no-hpet
1789 @findex -no-hpet
1790 Disable HPET support.
1791 ETEXI
1793 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1794 "-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"
1795 " ACPI table description\n", QEMU_ARCH_I386)
1796 STEXI
1797 @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}]...]
1798 @findex -acpitable
1799 Add ACPI table with specified header fields and context from specified files.
1800 For file=, take whole ACPI table from the specified files, including all
1801 ACPI headers (possible overridden by other options).
1802 For data=, only data
1803 portion of the table is used, all header information is specified in the
1804 command line.
1805 If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1806 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1807 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1808 spec.
1809 ETEXI
1811 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1812 "-smbios file=binary\n"
1813 " load SMBIOS entry from binary file\n"
1814 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1815 " [,uefi=on|off]\n"
1816 " specify SMBIOS type 0 fields\n"
1817 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1818 " [,uuid=uuid][,sku=str][,family=str]\n"
1819 " specify SMBIOS type 1 fields\n"
1820 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1821 " [,asset=str][,location=str]\n"
1822 " specify SMBIOS type 2 fields\n"
1823 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1824 " [,sku=str]\n"
1825 " specify SMBIOS type 3 fields\n"
1826 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1827 " [,asset=str][,part=str]\n"
1828 " specify SMBIOS type 4 fields\n"
1829 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1830 " [,asset=str][,part=str][,speed=%d]\n"
1831 " specify SMBIOS type 17 fields\n",
1832 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1833 STEXI
1834 @item -smbios file=@var{binary}
1835 @findex -smbios
1836 Load SMBIOS entry from binary file.
1838 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1839 Specify SMBIOS type 0 fields
1841 @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}]
1842 Specify SMBIOS type 1 fields
1844 @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}]
1845 Specify SMBIOS type 2 fields
1847 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1848 Specify SMBIOS type 3 fields
1850 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1851 Specify SMBIOS type 4 fields
1853 @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}]
1854 Specify SMBIOS type 17 fields
1855 ETEXI
1857 STEXI
1858 @end table
1859 ETEXI
1860 DEFHEADING()
1862 DEFHEADING(Network options)
1863 STEXI
1864 @table @option
1865 ETEXI
1867 HXCOMM Legacy slirp options (now moved to -net user):
1868 #ifdef CONFIG_SLIRP
1869 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1870 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1871 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1872 #ifndef _WIN32
1873 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1874 #endif
1875 #endif
1877 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1878 #ifdef CONFIG_SLIRP
1879 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1880 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1881 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1882 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
1883 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1884 #ifndef _WIN32
1885 "[,smb=dir[,smbserver=addr]]\n"
1886 #endif
1887 " configure a user mode network backend with ID 'str',\n"
1888 " its DHCP server and optional services\n"
1889 #endif
1890 #ifdef _WIN32
1891 "-netdev tap,id=str,ifname=name\n"
1892 " configure a host TAP network backend with ID 'str'\n"
1893 #else
1894 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1895 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1896 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1897 " [,poll-us=n]\n"
1898 " configure a host TAP network backend with ID 'str'\n"
1899 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1900 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1901 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1902 " to deconfigure it\n"
1903 " use '[down]script=no' to disable script execution\n"
1904 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1905 " configure it\n"
1906 " use 'fd=h' to connect to an already opened TAP interface\n"
1907 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1908 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1909 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1910 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1911 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1912 " use vhost=on to enable experimental in kernel accelerator\n"
1913 " (only has effect for virtio guests which use MSIX)\n"
1914 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1915 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
1916 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1917 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1918 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1919 " spent on busy polling for vhost net\n"
1920 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1921 " configure a host TAP network backend with ID 'str' that is\n"
1922 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1923 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1924 #endif
1925 #ifdef __linux__
1926 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1927 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1928 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1929 " [,rxcookie=rxcookie][,offset=offset]\n"
1930 " configure a network backend with ID 'str' connected to\n"
1931 " an Ethernet over L2TPv3 pseudowire.\n"
1932 " Linux kernel 3.3+ as well as most routers can talk\n"
1933 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1934 " VM to a router and even VM to Host. It is a nearly-universal\n"
1935 " standard (RFC3391). Note - this implementation uses static\n"
1936 " pre-configured tunnels (same as the Linux kernel).\n"
1937 " use 'src=' to specify source address\n"
1938 " use 'dst=' to specify destination address\n"
1939 " use 'udp=on' to specify udp encapsulation\n"
1940 " use 'srcport=' to specify source udp port\n"
1941 " use 'dstport=' to specify destination udp port\n"
1942 " use 'ipv6=on' to force v6\n"
1943 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1944 " well as a weak security measure\n"
1945 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
1946 " use 'txcookie=0x012345678' to specify a txcookie\n"
1947 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1948 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1949 " use 'pincounter=on' to work around broken counter handling in peer\n"
1950 " use 'offset=X' to add an extra offset between header and data\n"
1951 #endif
1952 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1953 " configure a network backend to connect to another network\n"
1954 " using a socket connection\n"
1955 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1956 " configure a network backend to connect to a multicast maddr and port\n"
1957 " use 'localaddr=addr' to specify the host address to send packets from\n"
1958 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1959 " configure a network backend to connect to another network\n"
1960 " using an UDP tunnel\n"
1961 #ifdef CONFIG_VDE
1962 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1963 " configure a network backend to connect to port 'n' of a vde switch\n"
1964 " running on host and listening for incoming connections on 'socketpath'.\n"
1965 " Use group 'groupname' and mode 'octalmode' to change default\n"
1966 " ownership and permissions for communication port.\n"
1967 #endif
1968 #ifdef CONFIG_NETMAP
1969 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1970 " attach to the existing netmap-enabled network interface 'name', or to a\n"
1971 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1972 " netmap device, defaults to '/dev/netmap')\n"
1973 #endif
1974 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1975 " configure a vhost-user network, backed by a chardev 'dev'\n"
1976 "-netdev hubport,id=str,hubid=n\n"
1977 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
1978 DEF("net", HAS_ARG, QEMU_OPTION_net,
1979 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1980 " old way to create a new NIC and connect it to VLAN 'n'\n"
1981 " (use the '-device devtype,netdev=str' option if possible instead)\n"
1982 "-net dump[,vlan=n][,file=f][,len=n]\n"
1983 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n"
1984 "-net none use it alone to have zero network devices. If no -net option\n"
1985 " is provided, the default is '-net nic -net user'\n"
1986 "-net ["
1987 #ifdef CONFIG_SLIRP
1988 "user|"
1989 #endif
1990 "tap|"
1991 "bridge|"
1992 #ifdef CONFIG_VDE
1993 "vde|"
1994 #endif
1995 #ifdef CONFIG_NETMAP
1996 "netmap|"
1997 #endif
1998 "socket][,vlan=n][,option][,option][,...]\n"
1999 " old way to initialize a host network interface\n"
2000 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2001 STEXI
2002 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2003 @findex -net
2004 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
2005 = 0 is the default). The NIC is an e1000 by default on the PC
2006 target. Optionally, the MAC address can be changed to @var{mac}, the
2007 device address set to @var{addr} (PCI cards only),
2008 and a @var{name} can be assigned for use in monitor commands.
2009 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2010 that the card should have; this option currently only affects virtio cards; set
2011 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2012 NIC is created. QEMU can emulate several different models of network card.
2013 Valid values for @var{type} are
2014 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
2015 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
2016 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
2017 Not all devices are supported on all targets. Use @code{-net nic,model=help}
2018 for a list of available devices for your target.
2020 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2021 @findex -netdev
2022 @item -net user[,@var{option}][,@var{option}][,...]
2023 Use the user mode network stack which requires no administrator
2024 privilege to run. Valid options are:
2026 @table @option
2027 @item vlan=@var{n}
2028 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
2030 @item id=@var{id}
2031 @itemx name=@var{name}
2032 Assign symbolic name for use in monitor commands.
2034 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
2035 be enabled. If neither is specified both protocols are enabled.
2037 @item net=@var{addr}[/@var{mask}]
2038 Set IP network address the guest will see. Optionally specify the netmask,
2039 either in the form a.b.c.d or as number of valid top-most bits. Default is
2040 10.0.2.0/24.
2042 @item host=@var{addr}
2043 Specify the guest-visible address of the host. Default is the 2nd IP in the
2044 guest network, i.e. x.x.x.2.
2046 @item ipv6-net=@var{addr}[/@var{int}]
2047 Set IPv6 network address the guest will see (default is fec0::/64). The
2048 network prefix is given in the usual hexadecimal IPv6 address
2049 notation. The prefix size is optional, and is given as the number of
2050 valid top-most bits (default is 64).
2052 @item ipv6-host=@var{addr}
2053 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2054 the guest network, i.e. xxxx::2.
2056 @item restrict=on|off
2057 If this option is enabled, the guest will be isolated, i.e. it will not be
2058 able to contact the host and no guest IP packets will be routed over the host
2059 to the outside. This option does not affect any explicitly set forwarding rules.
2061 @item hostname=@var{name}
2062 Specifies the client hostname reported by the built-in DHCP server.
2064 @item dhcpstart=@var{addr}
2065 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2066 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2068 @item dns=@var{addr}
2069 Specify the guest-visible address of the virtual nameserver. The address must
2070 be different from the host address. Default is the 3rd IP in the guest network,
2071 i.e. x.x.x.3.
2073 @item ipv6-dns=@var{addr}
2074 Specify the guest-visible address of the IPv6 virtual nameserver. The address
2075 must be different from the host address. Default is the 3rd IP in the guest
2076 network, i.e. xxxx::3.
2078 @item dnssearch=@var{domain}
2079 Provides an entry for the domain-search list sent by the built-in
2080 DHCP server. More than one domain suffix can be transmitted by specifying
2081 this option multiple times. If supported, this will cause the guest to
2082 automatically try to append the given domain suffix(es) in case a domain name
2083 can not be resolved.
2085 Example:
2086 @example
2087 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
2088 @end example
2090 @item tftp=@var{dir}
2091 When using the user mode network stack, activate a built-in TFTP
2092 server. The files in @var{dir} will be exposed as the root of a TFTP server.
2093 The TFTP client on the guest must be configured in binary mode (use the command
2094 @code{bin} of the Unix TFTP client).
2096 @item bootfile=@var{file}
2097 When using the user mode network stack, broadcast @var{file} as the BOOTP
2098 filename. In conjunction with @option{tftp}, this can be used to network boot
2099 a guest from a local directory.
2101 Example (using pxelinux):
2102 @example
2103 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2104 @end example
2106 @item smb=@var{dir}[,smbserver=@var{addr}]
2107 When using the user mode network stack, activate a built-in SMB
2108 server so that Windows OSes can access to the host files in @file{@var{dir}}
2109 transparently. The IP address of the SMB server can be set to @var{addr}. By
2110 default the 4th IP in the guest network is used, i.e. x.x.x.4.
2112 In the guest Windows OS, the line:
2113 @example
2114 10.0.2.4 smbserver
2115 @end example
2116 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2117 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2119 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2121 Note that a SAMBA server must be installed on the host OS.
2122 QEMU was tested successfully with smbd versions from Red Hat 9,
2123 Fedora Core 3 and OpenSUSE 11.x.
2125 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2126 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2127 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2128 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2129 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2130 be bound to a specific host interface. If no connection type is set, TCP is
2131 used. This option can be given multiple times.
2133 For example, to redirect host X11 connection from screen 1 to guest
2134 screen 0, use the following:
2136 @example
2137 # on the host
2138 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
2139 # this host xterm should open in the guest X11 server
2140 xterm -display :1
2141 @end example
2143 To redirect telnet connections from host port 5555 to telnet port on
2144 the guest, use the following:
2146 @example
2147 # on the host
2148 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
2149 telnet localhost 5555
2150 @end example
2152 Then when you use on the host @code{telnet localhost 5555}, you
2153 connect to the guest telnet server.
2155 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2156 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2157 Forward guest TCP connections to the IP address @var{server} on port @var{port}
2158 to the character device @var{dev} or to a program executed by @var{cmd:command}
2159 which gets spawned for each connection. This option can be given multiple times.
2161 You can either use a chardev directly and have that one used throughout QEMU's
2162 lifetime, like in the following example:
2164 @example
2165 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2166 # the guest accesses it
2167 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
2168 @end example
2170 Or you can execute a command on every TCP connection established by the guest,
2171 so that QEMU behaves similar to an inetd process for that virtual server:
2173 @example
2174 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2175 # and connect the TCP stream to its stdin/stdout
2176 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2177 @end example
2179 @end table
2181 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2182 processed and applied to -net user. Mixing them with the new configuration
2183 syntax gives undefined results. Their use for new applications is discouraged
2184 as they will be removed from future versions.
2186 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2187 @itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2188 Connect the host TAP network interface @var{name} to VLAN @var{n}.
2190 Use the network script @var{file} to configure it and the network script
2191 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2192 automatically provides one. The default network configure script is
2193 @file{/etc/qemu-ifup} and the default network deconfigure script is
2194 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2195 to disable script execution.
2197 If running QEMU as an unprivileged user, use the network helper
2198 @var{helper} to configure the TAP interface and attach it to the bridge.
2199 The default network helper executable is @file{/path/to/qemu-bridge-helper}
2200 and the default bridge device is @file{br0}.
2202 @option{fd}=@var{h} can be used to specify the handle of an already
2203 opened host TAP interface.
2205 Examples:
2207 @example
2208 #launch a QEMU instance with the default network script
2209 qemu-system-i386 linux.img -net nic -net tap
2210 @end example
2212 @example
2213 #launch a QEMU instance with two NICs, each one connected
2214 #to a TAP device
2215 qemu-system-i386 linux.img \
2216 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
2217 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
2218 @end example
2220 @example
2221 #launch a QEMU instance with the default network helper to
2222 #connect a TAP device to bridge br0
2223 qemu-system-i386 linux.img \
2224 -net nic -net tap,"helper=/path/to/qemu-bridge-helper"
2225 @end example
2227 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2228 @itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
2229 Connect a host TAP network interface to a host bridge device.
2231 Use the network helper @var{helper} to configure the TAP interface and
2232 attach it to the bridge. The default network helper executable is
2233 @file{/path/to/qemu-bridge-helper} and the default bridge
2234 device is @file{br0}.
2236 Examples:
2238 @example
2239 #launch a QEMU instance with the default network helper to
2240 #connect a TAP device to bridge br0
2241 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
2242 @end example
2244 @example
2245 #launch a QEMU instance with the default network helper to
2246 #connect a TAP device to bridge qemubr0
2247 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
2248 @end example
2250 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2251 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2253 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
2254 machine using a TCP socket connection. If @option{listen} is
2255 specified, QEMU waits for incoming connections on @var{port}
2256 (@var{host} is optional). @option{connect} is used to connect to
2257 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2258 specifies an already opened TCP socket.
2260 Example:
2261 @example
2262 # launch a first QEMU instance
2263 qemu-system-i386 linux.img \
2264 -net nic,macaddr=52:54:00:12:34:56 \
2265 -net socket,listen=:1234
2266 # connect the VLAN 0 of this instance to the VLAN 0
2267 # of the first instance
2268 qemu-system-i386 linux.img \
2269 -net nic,macaddr=52:54:00:12:34:57 \
2270 -net socket,connect=127.0.0.1:1234
2271 @end example
2273 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2274 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2276 Create a VLAN @var{n} shared with another QEMU virtual
2277 machines using a UDP multicast socket, effectively making a bus for
2278 every QEMU with same multicast address @var{maddr} and @var{port}.
2279 NOTES:
2280 @enumerate
2281 @item
2282 Several QEMU can be running on different hosts and share same bus (assuming
2283 correct multicast setup for these hosts).
2284 @item
2285 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2286 @url{http://user-mode-linux.sf.net}.
2287 @item
2288 Use @option{fd=h} to specify an already opened UDP multicast socket.
2289 @end enumerate
2291 Example:
2292 @example
2293 # launch one QEMU instance
2294 qemu-system-i386 linux.img \
2295 -net nic,macaddr=52:54:00:12:34:56 \
2296 -net socket,mcast=230.0.0.1:1234
2297 # launch another QEMU instance on same "bus"
2298 qemu-system-i386 linux.img \
2299 -net nic,macaddr=52:54:00:12:34:57 \
2300 -net socket,mcast=230.0.0.1:1234
2301 # launch yet another QEMU instance on same "bus"
2302 qemu-system-i386 linux.img \
2303 -net nic,macaddr=52:54:00:12:34:58 \
2304 -net socket,mcast=230.0.0.1:1234
2305 @end example
2307 Example (User Mode Linux compat.):
2308 @example
2309 # launch QEMU instance (note mcast address selected
2310 # is UML's default)
2311 qemu-system-i386 linux.img \
2312 -net nic,macaddr=52:54:00:12:34:56 \
2313 -net socket,mcast=239.192.168.1:1102
2314 # launch UML
2315 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2316 @end example
2318 Example (send packets from host's 1.2.3.4):
2319 @example
2320 qemu-system-i386 linux.img \
2321 -net nic,macaddr=52:54:00:12:34:56 \
2322 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2323 @end example
2325 @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}]
2326 @itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}]
2327 Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
2328 protocol to transport Ethernet (and other Layer 2) data frames between
2329 two systems. It is present in routers, firewalls and the Linux kernel
2330 (from version 3.3 onwards).
2332 This transport allows a VM to communicate to another VM, router or firewall directly.
2334 @item src=@var{srcaddr}
2335 source address (mandatory)
2336 @item dst=@var{dstaddr}
2337 destination address (mandatory)
2338 @item udp
2339 select udp encapsulation (default is ip).
2340 @item srcport=@var{srcport}
2341 source udp port.
2342 @item dstport=@var{dstport}
2343 destination udp port.
2344 @item ipv6
2345 force v6, otherwise defaults to v4.
2346 @item rxcookie=@var{rxcookie}
2347 @itemx txcookie=@var{txcookie}
2348 Cookies are a weak form of security in the l2tpv3 specification.
2349 Their function is mostly to prevent misconfiguration. By default they are 32
2350 bit.
2351 @item cookie64
2352 Set cookie size to 64 bit instead of the default 32
2353 @item counter=off
2354 Force a 'cut-down' L2TPv3 with no counter as in
2355 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2356 @item pincounter=on
2357 Work around broken counter handling in peer. This may also help on
2358 networks which have packet reorder.
2359 @item offset=@var{offset}
2360 Add an extra offset between header and data
2362 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2363 on the remote Linux host 1.2.3.4:
2364 @example
2365 # Setup tunnel on linux host using raw ip as encapsulation
2366 # on 1.2.3.4
2367 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2368 encap udp udp_sport 16384 udp_dport 16384
2369 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2370 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2371 ifconfig vmtunnel0 mtu 1500
2372 ifconfig vmtunnel0 up
2373 brctl addif br-lan vmtunnel0
2376 # on 4.3.2.1
2377 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2379 qemu-system-i386 linux.img -net nic -net l2tpv3,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2382 @end example
2384 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2385 @itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2386 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2387 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2388 and MODE @var{octalmode} to change default ownership and permissions for
2389 communication port. This option is only available if QEMU has been compiled
2390 with vde support enabled.
2392 Example:
2393 @example
2394 # launch vde switch
2395 vde_switch -F -sock /tmp/myswitch
2396 # launch QEMU instance
2397 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2398 @end example
2400 @item -netdev hubport,id=@var{id},hubid=@var{hubid}
2402 Create a hub port on QEMU "vlan" @var{hubid}.
2404 The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single
2405 netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
2406 required hub automatically.
2408 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2410 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2411 be a unix domain socket backed one. The vhost-user uses a specifically defined
2412 protocol to pass vhost ioctl replacement messages to an application on the other
2413 end of the socket. On non-MSIX guests, the feature can be forced with
2414 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2415 be created for multiqueue vhost-user.
2417 Example:
2418 @example
2419 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2420 -numa node,memdev=mem \
2421 -chardev socket,id=chr0,path=/path/to/socket \
2422 -netdev type=vhost-user,id=net0,chardev=chr0 \
2423 -device virtio-net-pci,netdev=net0
2424 @end example
2426 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
2427 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
2428 At most @var{len} bytes (64k by default) per packet are stored. The file format is
2429 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
2430 Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
2432 @item -net none
2433 Indicate that no network devices should be configured. It is used to
2434 override the default configuration (@option{-net nic -net user}) which
2435 is activated if no @option{-net} options are provided.
2436 ETEXI
2438 STEXI
2439 @end table
2440 ETEXI
2441 DEFHEADING()
2443 DEFHEADING(Character device options)
2444 STEXI
2446 The general form of a character device option is:
2447 @table @option
2448 ETEXI
2450 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2451 "-chardev help\n"
2452 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2453 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2454 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2455 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2456 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2457 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2458 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2459 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2460 " [,logfile=PATH][,logappend=on|off]\n"
2461 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2462 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2463 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2464 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2465 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2466 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2467 #ifdef _WIN32
2468 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2469 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2470 #else
2471 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2472 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2473 #endif
2474 #ifdef CONFIG_BRLAPI
2475 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2476 #endif
2477 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2478 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2479 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2480 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2481 #endif
2482 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2483 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2484 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2485 #endif
2486 #if defined(CONFIG_SPICE)
2487 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2488 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2489 #endif
2490 , QEMU_ARCH_ALL
2493 STEXI
2494 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
2495 @findex -chardev
2496 Backend is one of:
2497 @option{null},
2498 @option{socket},
2499 @option{udp},
2500 @option{msmouse},
2501 @option{vc},
2502 @option{ringbuf},
2503 @option{file},
2504 @option{pipe},
2505 @option{console},
2506 @option{serial},
2507 @option{pty},
2508 @option{stdio},
2509 @option{braille},
2510 @option{tty},
2511 @option{parallel},
2512 @option{parport},
2513 @option{spicevmc}.
2514 @option{spiceport}.
2515 The specific backend will determine the applicable options.
2517 Use "-chardev help" to print all available chardev backend types.
2519 All devices must have an id, which can be any string up to 127 characters long.
2520 It is used to uniquely identify this device in other command line directives.
2522 A character device may be used in multiplexing mode by multiple front-ends.
2523 Specify @option{mux=on} to enable this mode.
2524 A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2525 backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2526 If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2527 create a multiplexer with your specified ID, and you can then configure multiple
2528 front ends to use that chardev ID for their input/output. Up to four different
2529 front ends can be connected to a single multiplexed chardev. (Without
2530 multiplexing enabled, a chardev can only be used by a single front end.)
2531 For instance you could use this to allow a single stdio chardev to be used by
2532 two serial ports and the QEMU monitor:
2534 @example
2535 -chardev stdio,mux=on,id=char0 \
2536 -mon chardev=char0,mode=readline \
2537 -serial chardev:char0 \
2538 -serial chardev:char0
2539 @end example
2541 You can have more than one multiplexer in a system configuration; for instance
2542 you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2543 multiplexed between the QEMU monitor and a parallel port:
2545 @example
2546 -chardev stdio,mux=on,id=char0 \
2547 -mon chardev=char0,mode=readline \
2548 -parallel chardev:char0 \
2549 -chardev tcp,...,mux=on,id=char1 \
2550 -serial chardev:char1 \
2551 -serial chardev:char1
2552 @end example
2554 When you're using a multiplexed character device, some escape sequences are
2555 interpreted in the input. @xref{mux_keys, Keys in the character backend
2556 multiplexer}.
2558 Note that some other command line options may implicitly create multiplexed
2559 character backends; for instance @option{-serial mon:stdio} creates a
2560 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2561 and @option{-nographic} also multiplexes the console and the monitor to
2562 stdio.
2564 There is currently no support for multiplexing in the other direction
2565 (where a single QEMU front end takes input and output from multiple chardevs).
2567 Every backend supports the @option{logfile} option, which supplies the path
2568 to a file to record all data transmitted via the backend. The @option{logappend}
2569 option controls whether the log file will be truncated or appended to when
2570 opened.
2572 Further options to each backend are described below.
2574 @item -chardev null ,id=@var{id}
2575 A void device. This device will not emit any data, and will drop any data it
2576 receives. The null backend does not take any options.
2578 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}]
2580 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2581 unix socket will be created if @option{path} is specified. Behaviour is
2582 undefined if TCP options are specified for a unix socket.
2584 @option{server} specifies that the socket shall be a listening socket.
2586 @option{nowait} specifies that QEMU should not block waiting for a client to
2587 connect to a listening socket.
2589 @option{telnet} specifies that traffic on the socket should interpret telnet
2590 escape sequences.
2592 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2593 the remote end goes away. qemu will delay this many seconds and then attempt
2594 to reconnect. Zero disables reconnecting, and is the default.
2596 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2597 and specifies the id of the TLS credentials to use for the handshake. The
2598 credentials must be previously created with the @option{-object tls-creds}
2599 argument.
2601 TCP and unix socket options are given below:
2603 @table @option
2605 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2607 @option{host} for a listening socket specifies the local address to be bound.
2608 For a connecting socket species the remote host to connect to. @option{host} is
2609 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2611 @option{port} for a listening socket specifies the local port to be bound. For a
2612 connecting socket specifies the port on the remote host to connect to.
2613 @option{port} can be given as either a port number or a service name.
2614 @option{port} is required.
2616 @option{to} is only relevant to listening sockets. If it is specified, and
2617 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2618 to and including @option{to} until it succeeds. @option{to} must be specified
2619 as a port number.
2621 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2622 If neither is specified the socket may use either protocol.
2624 @option{nodelay} disables the Nagle algorithm.
2626 @item unix options: path=@var{path}
2628 @option{path} specifies the local path of the unix socket. @option{path} is
2629 required.
2631 @end table
2633 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2635 Sends all traffic from the guest to a remote host over UDP.
2637 @option{host} specifies the remote host to connect to. If not specified it
2638 defaults to @code{localhost}.
2640 @option{port} specifies the port on the remote host to connect to. @option{port}
2641 is required.
2643 @option{localaddr} specifies the local address to bind to. If not specified it
2644 defaults to @code{0.0.0.0}.
2646 @option{localport} specifies the local port to bind to. If not specified any
2647 available local port will be used.
2649 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2650 If neither is specified the device may use either protocol.
2652 @item -chardev msmouse ,id=@var{id}
2654 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2655 take any options.
2657 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2659 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2660 size.
2662 @option{width} and @option{height} specify the width and height respectively of
2663 the console, in pixels.
2665 @option{cols} and @option{rows} specify that the console be sized to fit a text
2666 console with the given dimensions.
2668 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2670 Create a ring buffer with fixed size @option{size}.
2671 @var{size} must be a power of two and defaults to @code{64K}.
2673 @item -chardev file ,id=@var{id} ,path=@var{path}
2675 Log all traffic received from the guest to a file.
2677 @option{path} specifies the path of the file to be opened. This file will be
2678 created if it does not already exist, and overwritten if it does. @option{path}
2679 is required.
2681 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2683 Create a two-way connection to the guest. The behaviour differs slightly between
2684 Windows hosts and other hosts:
2686 On Windows, a single duplex pipe will be created at
2687 @file{\\.pipe\@option{path}}.
2689 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2690 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2691 received by the guest. Data written by the guest can be read from
2692 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2693 be present.
2695 @option{path} forms part of the pipe path as described above. @option{path} is
2696 required.
2698 @item -chardev console ,id=@var{id}
2700 Send traffic from the guest to QEMU's standard output. @option{console} does not
2701 take any options.
2703 @option{console} is only available on Windows hosts.
2705 @item -chardev serial ,id=@var{id} ,path=@option{path}
2707 Send traffic from the guest to a serial device on the host.
2709 On Unix hosts serial will actually accept any tty device,
2710 not only serial lines.
2712 @option{path} specifies the name of the serial device to open.
2714 @item -chardev pty ,id=@var{id}
2716 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2717 not take any options.
2719 @option{pty} is not available on Windows hosts.
2721 @item -chardev stdio ,id=@var{id} [,signal=on|off]
2722 Connect to standard input and standard output of the QEMU process.
2724 @option{signal} controls if signals are enabled on the terminal, that includes
2725 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2726 default, use @option{signal=off} to disable it.
2728 @item -chardev braille ,id=@var{id}
2730 Connect to a local BrlAPI server. @option{braille} does not take any options.
2732 @item -chardev tty ,id=@var{id} ,path=@var{path}
2734 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2735 DragonFlyBSD hosts. It is an alias for @option{serial}.
2737 @option{path} specifies the path to the tty. @option{path} is required.
2739 @item -chardev parallel ,id=@var{id} ,path=@var{path}
2740 @itemx -chardev parport ,id=@var{id} ,path=@var{path}
2742 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2744 Connect to a local parallel port.
2746 @option{path} specifies the path to the parallel port device. @option{path} is
2747 required.
2749 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2751 @option{spicevmc} is only available when spice support is built in.
2753 @option{debug} debug level for spicevmc
2755 @option{name} name of spice channel to connect to
2757 Connect to a spice virtual machine channel, such as vdiport.
2759 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2761 @option{spiceport} is only available when spice support is built in.
2763 @option{debug} debug level for spicevmc
2765 @option{name} name of spice port to connect to
2767 Connect to a spice port, allowing a Spice client to handle the traffic
2768 identified by a name (preferably a fqdn).
2769 ETEXI
2771 STEXI
2772 @end table
2773 ETEXI
2774 DEFHEADING()
2776 DEFHEADING(Device URL Syntax)
2777 STEXI
2779 In addition to using normal file images for the emulated storage devices,
2780 QEMU can also use networked resources such as iSCSI devices. These are
2781 specified using a special URL syntax.
2783 @table @option
2784 @item iSCSI
2785 iSCSI support allows QEMU to access iSCSI resources directly and use as
2786 images for the guest storage. Both disk and cdrom images are supported.
2788 Syntax for specifying iSCSI LUNs is
2789 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2791 By default qemu will use the iSCSI initiator-name
2792 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2793 line or a configuration file.
2795 Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2796 stalled requests and force a reestablishment of the session. The timeout
2797 is specified in seconds. The default is 0 which means no timeout. Libiscsi
2798 1.15.0 or greater is required for this feature.
2800 Example (without authentication):
2801 @example
2802 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2803 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2804 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2805 @end example
2807 Example (CHAP username/password via URL):
2808 @example
2809 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2810 @end example
2812 Example (CHAP username/password via environment variables):
2813 @example
2814 LIBISCSI_CHAP_USERNAME="user" \
2815 LIBISCSI_CHAP_PASSWORD="password" \
2816 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2817 @end example
2819 iSCSI support is an optional feature of QEMU and only available when
2820 compiled and linked against libiscsi.
2821 ETEXI
2822 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
2823 "-iscsi [user=user][,password=password]\n"
2824 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2825 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2826 " [,timeout=timeout]\n"
2827 " iSCSI session parameters\n", QEMU_ARCH_ALL)
2828 STEXI
2830 iSCSI parameters such as username and password can also be specified via
2831 a configuration file. See qemu-doc for more information and examples.
2833 @item NBD
2834 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2835 as Unix Domain Sockets.
2837 Syntax for specifying a NBD device using TCP
2838 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2840 Syntax for specifying a NBD device using Unix Domain Sockets
2841 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2844 Example for TCP
2845 @example
2846 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2847 @end example
2849 Example for Unix Domain Sockets
2850 @example
2851 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2852 @end example
2854 @item SSH
2855 QEMU supports SSH (Secure Shell) access to remote disks.
2857 Examples:
2858 @example
2859 qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2860 qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2861 @end example
2863 Currently authentication must be done using ssh-agent. Other
2864 authentication methods may be supported in future.
2866 @item Sheepdog
2867 Sheepdog is a distributed storage system for QEMU.
2868 QEMU supports using either local sheepdog devices or remote networked
2869 devices.
2871 Syntax for specifying a sheepdog device
2872 @example
2873 sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2874 @end example
2876 Example
2877 @example
2878 qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2879 @end example
2881 See also @url{https://sheepdog.github.io/sheepdog/}.
2883 @item GlusterFS
2884 GlusterFS is a user space distributed file system.
2885 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2886 TCP, Unix Domain Sockets and RDMA transport protocols.
2888 Syntax for specifying a VM disk image on GlusterFS volume is
2889 @example
2891 URI:
2892 gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]
2894 JSON:
2895 'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
2896 @ "server":[@{"type":"tcp","host":"...","port":"..."@},
2897 @ @{"type":"unix","socket":"..."@}]@}@}'
2898 @end example
2901 Example
2902 @example
2903 URI:
2904 qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img,
2905 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log
2907 JSON:
2908 qemu-system-x86_64 'json:@{"driver":"qcow2",
2909 @ "file":@{"driver":"gluster",
2910 @ "volume":"testvol","path":"a.img",
2911 @ "debug":9,"logfile":"/var/log/qemu-gluster.log",
2912 @ "server":[@{"type":"tcp","host":"1.2.3.4","port":24007@},
2913 @ @{"type":"unix","socket":"/var/run/glusterd.socket"@}]@}@}'
2914 qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
2915 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log,
2916 @ file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
2917 @ file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket
2918 @end example
2920 See also @url{http://www.gluster.org}.
2922 @item HTTP/HTTPS/FTP/FTPS
2923 QEMU supports read-only access to files accessed over http(s) and ftp(s).
2925 Syntax using a single filename:
2926 @example
2927 <protocol>://[<username>[:<password>]@@]<host>/<path>
2928 @end example
2930 where:
2931 @table @option
2932 @item protocol
2933 'http', 'https', 'ftp', or 'ftps'.
2935 @item username
2936 Optional username for authentication to the remote server.
2938 @item password
2939 Optional password for authentication to the remote server.
2941 @item host
2942 Address of the remote server.
2944 @item path
2945 Path on the remote server, including any query string.
2946 @end table
2948 The following options are also supported:
2949 @table @option
2950 @item url
2951 The full URL when passing options to the driver explicitly.
2953 @item readahead
2954 The amount of data to read ahead with each range request to the remote server.
2955 This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
2956 does not have a suffix, it will be assumed to be in bytes. The value must be a
2957 multiple of 512 bytes. It defaults to 256k.
2959 @item sslverify
2960 Whether to verify the remote server's certificate when connecting over SSL. It
2961 can have the value 'on' or 'off'. It defaults to 'on'.
2963 @item cookie
2964 Send this cookie (it can also be a list of cookies separated by ';') with
2965 each outgoing request. Only supported when using protocols such as HTTP
2966 which support cookies, otherwise ignored.
2968 @item timeout
2969 Set the timeout in seconds of the CURL connection. This timeout is the time
2970 that CURL waits for a response from the remote server to get the size of the
2971 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2972 @end table
2974 Note that when passing options to qemu explicitly, @option{driver} is the value
2975 of <protocol>.
2977 Example: boot from a remote Fedora 20 live ISO image
2978 @example
2979 qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2981 qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2982 @end example
2984 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2985 writes, copy-on-read, and a readahead of 64k
2986 @example
2987 qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2
2989 qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
2990 @end example
2992 Example: boot from an image stored on a VMware vSphere server with a self-signed
2993 certificate using a local overlay for writes, a readahead of 64k and a timeout
2994 of 10 seconds.
2995 @example
2996 qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@}' /tmp/test.qcow2
2998 qemu-system-x86_64 -drive file=/tmp/test.qcow2
2999 @end example
3000 ETEXI
3002 STEXI
3003 @end table
3004 ETEXI
3006 DEFHEADING(Bluetooth(R) options)
3007 STEXI
3008 @table @option
3009 ETEXI
3011 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
3012 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
3013 "-bt hci,host[:id]\n" \
3014 " use host's HCI with the given name\n" \
3015 "-bt hci[,vlan=n]\n" \
3016 " emulate a standard HCI in virtual scatternet 'n'\n" \
3017 "-bt vhci[,vlan=n]\n" \
3018 " add host computer to virtual scatternet 'n' using VHCI\n" \
3019 "-bt device:dev[,vlan=n]\n" \
3020 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
3021 QEMU_ARCH_ALL)
3022 STEXI
3023 @item -bt hci[...]
3024 @findex -bt
3025 Defines the function of the corresponding Bluetooth HCI. -bt options
3026 are matched with the HCIs present in the chosen machine type. For
3027 example when emulating a machine with only one HCI built into it, only
3028 the first @code{-bt hci[...]} option is valid and defines the HCI's
3029 logic. The Transport Layer is decided by the machine type. Currently
3030 the machines @code{n800} and @code{n810} have one HCI and all other
3031 machines have none.
3033 @anchor{bt-hcis}
3034 The following three types are recognized:
3036 @table @option
3037 @item -bt hci,null
3038 (default) The corresponding Bluetooth HCI assumes no internal logic
3039 and will not respond to any HCI commands or emit events.
3041 @item -bt hci,host[:@var{id}]
3042 (@code{bluez} only) The corresponding HCI passes commands / events
3043 to / from the physical HCI identified by the name @var{id} (default:
3044 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
3045 capable systems like Linux.
3047 @item -bt hci[,vlan=@var{n}]
3048 Add a virtual, standard HCI that will participate in the Bluetooth
3049 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
3050 VLANs, devices inside a bluetooth network @var{n} can only communicate
3051 with other devices in the same network (scatternet).
3052 @end table
3054 @item -bt vhci[,vlan=@var{n}]
3055 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
3056 to the host bluetooth stack instead of to the emulated target. This
3057 allows the host and target machines to participate in a common scatternet
3058 and communicate. Requires the Linux @code{vhci} driver installed. Can
3059 be used as following:
3061 @example
3062 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
3063 @end example
3065 @item -bt device:@var{dev}[,vlan=@var{n}]
3066 Emulate a bluetooth device @var{dev} and place it in network @var{n}
3067 (default @code{0}). QEMU can only emulate one type of bluetooth devices
3068 currently:
3070 @table @option
3071 @item keyboard
3072 Virtual wireless keyboard implementing the HIDP bluetooth profile.
3073 @end table
3074 ETEXI
3076 STEXI
3077 @end table
3078 ETEXI
3079 DEFHEADING()
3081 #ifdef CONFIG_TPM
3082 DEFHEADING(TPM device options)
3084 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
3085 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
3086 " use path to provide path to a character device; default is /dev/tpm0\n"
3087 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
3088 " not provided it will be searched for in /sys/class/misc/tpm?/device\n",
3089 QEMU_ARCH_ALL)
3090 STEXI
3092 The general form of a TPM device option is:
3093 @table @option
3095 @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
3096 @findex -tpmdev
3097 Backend type must be:
3098 @option{passthrough}.
3100 The specific backend type will determine the applicable options.
3101 The @code{-tpmdev} option creates the TPM backend and requires a
3102 @code{-device} option that specifies the TPM frontend interface model.
3104 Options to each backend are described below.
3106 Use 'help' to print all available TPM backend types.
3107 @example
3108 qemu -tpmdev help
3109 @end example
3111 @item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
3113 (Linux-host only) Enable access to the host's TPM using the passthrough
3114 driver.
3116 @option{path} specifies the path to the host's TPM device, i.e., on
3117 a Linux host this would be @code{/dev/tpm0}.
3118 @option{path} is optional and by default @code{/dev/tpm0} is used.
3120 @option{cancel-path} specifies the path to the host TPM device's sysfs
3121 entry allowing for cancellation of an ongoing TPM command.
3122 @option{cancel-path} is optional and by default QEMU will search for the
3123 sysfs entry to use.
3125 Some notes about using the host's TPM with the passthrough driver:
3127 The TPM device accessed by the passthrough driver must not be
3128 used by any other application on the host.
3130 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
3131 the VM's firmware (BIOS/UEFI) will not be able to initialize the
3132 TPM again and may therefore not show a TPM-specific menu that would
3133 otherwise allow the user to configure the TPM, e.g., allow the user to
3134 enable/disable or activate/deactivate the TPM.
3135 Further, if TPM ownership is released from within a VM then the host's TPM
3136 will get disabled and deactivated. To enable and activate the
3137 TPM again afterwards, the host has to be rebooted and the user is
3138 required to enter the firmware's menu to enable and activate the TPM.
3139 If the TPM is left disabled and/or deactivated most TPM commands will fail.
3141 To create a passthrough TPM use the following two options:
3142 @example
3143 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
3144 @end example
3145 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
3146 @code{tpmdev=tpm0} in the device option.
3148 @end table
3150 ETEXI
3152 DEFHEADING()
3154 #endif
3156 DEFHEADING(Linux/Multiboot boot specific)
3157 STEXI
3159 When using these options, you can use a given Linux or Multiboot
3160 kernel without installing it in the disk image. It can be useful
3161 for easier testing of various kernels.
3163 @table @option
3164 ETEXI
3166 DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
3167 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
3168 STEXI
3169 @item -kernel @var{bzImage}
3170 @findex -kernel
3171 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
3172 or in multiboot format.
3173 ETEXI
3175 DEF("append", HAS_ARG, QEMU_OPTION_append, \
3176 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
3177 STEXI
3178 @item -append @var{cmdline}
3179 @findex -append
3180 Use @var{cmdline} as kernel command line
3181 ETEXI
3183 DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
3184 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
3185 STEXI
3186 @item -initrd @var{file}
3187 @findex -initrd
3188 Use @var{file} as initial ram disk.
3190 @item -initrd "@var{file1} arg=foo,@var{file2}"
3192 This syntax is only available with multiboot.
3194 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3195 first module.
3196 ETEXI
3198 DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
3199 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
3200 STEXI
3201 @item -dtb @var{file}
3202 @findex -dtb
3203 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3204 on boot.
3205 ETEXI
3207 STEXI
3208 @end table
3209 ETEXI
3210 DEFHEADING()
3212 DEFHEADING(Debug/Expert options)
3213 STEXI
3214 @table @option
3215 ETEXI
3217 DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3218 "-fw_cfg [name=]<name>,file=<file>\n"
3219 " add named fw_cfg entry with contents from file\n"
3220 "-fw_cfg [name=]<name>,string=<str>\n"
3221 " add named fw_cfg entry with contents from string\n",
3222 QEMU_ARCH_ALL)
3223 STEXI
3225 @item -fw_cfg [name=]@var{name},file=@var{file}
3226 @findex -fw_cfg
3227 Add named fw_cfg entry with contents from file @var{file}.
3229 @item -fw_cfg [name=]@var{name},string=@var{str}
3230 Add named fw_cfg entry with contents from string @var{str}.
3232 The terminating NUL character of the contents of @var{str} will not be
3233 included as part of the fw_cfg item data. To insert contents with
3234 embedded NUL characters, you have to use the @var{file} parameter.
3236 The fw_cfg entries are passed by QEMU through to the guest.
3238 Example:
3239 @example
3240 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3241 @end example
3242 creates an fw_cfg entry named opt/com.mycompany/blob with contents
3243 from ./my_blob.bin.
3245 ETEXI
3247 DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3248 "-serial dev redirect the serial port to char device 'dev'\n",
3249 QEMU_ARCH_ALL)
3250 STEXI
3251 @item -serial @var{dev}
3252 @findex -serial
3253 Redirect the virtual serial port to host character device
3254 @var{dev}. The default device is @code{vc} in graphical mode and
3255 @code{stdio} in non graphical mode.
3257 This option can be used several times to simulate up to 4 serial
3258 ports.
3260 Use @code{-serial none} to disable all serial ports.
3262 Available character devices are:
3263 @table @option
3264 @item vc[:@var{W}x@var{H}]
3265 Virtual console. Optionally, a width and height can be given in pixel with
3266 @example
3267 vc:800x600
3268 @end example
3269 It is also possible to specify width or height in characters:
3270 @example
3271 vc:80Cx24C
3272 @end example
3273 @item pty
3274 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3275 @item none
3276 No device is allocated.
3277 @item null
3278 void device
3279 @item chardev:@var{id}
3280 Use a named character device defined with the @code{-chardev} option.
3281 @item /dev/XXX
3282 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3283 parameters are set according to the emulated ones.
3284 @item /dev/parport@var{N}
3285 [Linux only, parallel port only] Use host parallel port
3286 @var{N}. Currently SPP and EPP parallel port features can be used.
3287 @item file:@var{filename}
3288 Write output to @var{filename}. No character can be read.
3289 @item stdio
3290 [Unix only] standard input/output
3291 @item pipe:@var{filename}
3292 name pipe @var{filename}
3293 @item COM@var{n}
3294 [Windows only] Use host serial port @var{n}
3295 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3296 This implements UDP Net Console.
3297 When @var{remote_host} or @var{src_ip} are not specified
3298 they default to @code{0.0.0.0}.
3299 When not using a specified @var{src_port} a random port is automatically chosen.
3301 If you just want a simple readonly console you can use @code{netcat} or
3302 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3303 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3304 will appear in the netconsole session.
3306 If you plan to send characters back via netconsole or you want to stop
3307 and start QEMU a lot of times, you should have QEMU use the same
3308 source port each time by using something like @code{-serial
3309 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3310 version of netcat which can listen to a TCP port and send and receive
3311 characters via udp. If you have a patched version of netcat which
3312 activates telnet remote echo and single char transfer, then you can
3313 use the following options to set up a netcat redirector to allow
3314 telnet on port 5555 to access the QEMU port.
3315 @table @code
3316 @item QEMU Options:
3317 -serial udp::4555@@:4556
3318 @item netcat options:
3319 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3320 @item telnet options:
3321 localhost 5555
3322 @end table
3324 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3325 The TCP Net Console has two modes of operation. It can send the serial
3326 I/O to a location or wait for a connection from a location. By default
3327 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3328 the @var{server} option QEMU will wait for a client socket application
3329 to connect to the port before continuing, unless the @code{nowait}
3330 option was specified. The @code{nodelay} option disables the Nagle buffering
3331 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3332 set, if the connection goes down it will attempt to reconnect at the
3333 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3334 one TCP connection at a time is accepted. You can use @code{telnet} to
3335 connect to the corresponding character device.
3336 @table @code
3337 @item Example to send tcp console to 192.168.0.2 port 4444
3338 -serial tcp:192.168.0.2:4444
3339 @item Example to listen and wait on port 4444 for connection
3340 -serial tcp::4444,server
3341 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3342 -serial tcp:192.168.0.100:4444,server,nowait
3343 @end table
3345 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3346 The telnet protocol is used instead of raw tcp sockets. The options
3347 work the same as if you had specified @code{-serial tcp}. The
3348 difference is that the port acts like a telnet server or client using
3349 telnet option negotiation. This will also allow you to send the
3350 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3351 sequence. Typically in unix telnet you do it with Control-] and then
3352 type "send break" followed by pressing the enter key.
3354 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3355 A unix domain socket is used instead of a tcp socket. The option works the
3356 same as if you had specified @code{-serial tcp} except the unix domain socket
3357 @var{path} is used for connections.
3359 @item mon:@var{dev_string}
3360 This is a special option to allow the monitor to be multiplexed onto
3361 another serial port. The monitor is accessed with key sequence of
3362 @key{Control-a} and then pressing @key{c}.
3363 @var{dev_string} should be any one of the serial devices specified
3364 above. An example to multiplex the monitor onto a telnet server
3365 listening on port 4444 would be:
3366 @table @code
3367 @item -serial mon:telnet::4444,server,nowait
3368 @end table
3369 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3370 QEMU any more but will be passed to the guest instead.
3372 @item braille
3373 Braille device. This will use BrlAPI to display the braille output on a real
3374 or fake device.
3376 @item msmouse
3377 Three button serial mouse. Configure the guest to use Microsoft protocol.
3378 @end table
3379 ETEXI
3381 DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3382 "-parallel dev redirect the parallel port to char device 'dev'\n",
3383 QEMU_ARCH_ALL)
3384 STEXI
3385 @item -parallel @var{dev}
3386 @findex -parallel
3387 Redirect the virtual parallel port to host device @var{dev} (same
3388 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3389 be used to use hardware devices connected on the corresponding host
3390 parallel port.
3392 This option can be used several times to simulate up to 3 parallel
3393 ports.
3395 Use @code{-parallel none} to disable all parallel ports.
3396 ETEXI
3398 DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3399 "-monitor dev redirect the monitor to char device 'dev'\n",
3400 QEMU_ARCH_ALL)
3401 STEXI
3402 @item -monitor @var{dev}
3403 @findex -monitor
3404 Redirect the monitor to host device @var{dev} (same devices as the
3405 serial port).
3406 The default device is @code{vc} in graphical mode and @code{stdio} in
3407 non graphical mode.
3408 Use @code{-monitor none} to disable the default monitor.
3409 ETEXI
3410 DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3411 "-qmp dev like -monitor but opens in 'control' mode\n",
3412 QEMU_ARCH_ALL)
3413 STEXI
3414 @item -qmp @var{dev}
3415 @findex -qmp
3416 Like -monitor but opens in 'control' mode.
3417 ETEXI
3418 DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3419 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3420 QEMU_ARCH_ALL)
3421 STEXI
3422 @item -qmp-pretty @var{dev}
3423 @findex -qmp-pretty
3424 Like -qmp but uses pretty JSON formatting.
3425 ETEXI
3427 DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3428 "-mon [chardev=]name[,mode=readline|control]\n", QEMU_ARCH_ALL)
3429 STEXI
3430 @item -mon [chardev=]name[,mode=readline|control]
3431 @findex -mon
3432 Setup monitor on chardev @var{name}.
3433 ETEXI
3435 DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3436 "-debugcon dev redirect the debug console to char device 'dev'\n",
3437 QEMU_ARCH_ALL)
3438 STEXI
3439 @item -debugcon @var{dev}
3440 @findex -debugcon
3441 Redirect the debug console to host device @var{dev} (same devices as the
3442 serial port). The debug console is an I/O port which is typically port
3443 0xe9; writing to that I/O port sends output to this device.
3444 The default device is @code{vc} in graphical mode and @code{stdio} in
3445 non graphical mode.
3446 ETEXI
3448 DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3449 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
3450 STEXI
3451 @item -pidfile @var{file}
3452 @findex -pidfile
3453 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3454 from a script.
3455 ETEXI
3457 DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3458 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
3459 STEXI
3460 @item -singlestep
3461 @findex -singlestep
3462 Run the emulation in single step mode.
3463 ETEXI
3465 DEF("S", 0, QEMU_OPTION_S, \
3466 "-S freeze CPU at startup (use 'c' to start execution)\n",
3467 QEMU_ARCH_ALL)
3468 STEXI
3469 @item -S
3470 @findex -S
3471 Do not start CPU at startup (you must type 'c' in the monitor).
3472 ETEXI
3474 DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3475 "-realtime [mlock=on|off]\n"
3476 " run qemu with realtime features\n"
3477 " mlock=on|off controls mlock support (default: on)\n",
3478 QEMU_ARCH_ALL)
3479 STEXI
3480 @item -realtime mlock=on|off
3481 @findex -realtime
3482 Run qemu with realtime features.
3483 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3484 (enabled by default).
3485 ETEXI
3487 DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3488 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3489 STEXI
3490 @item -gdb @var{dev}
3491 @findex -gdb
3492 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3493 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3494 stdio are reasonable use case. The latter is allowing to start QEMU from
3495 within gdb and establish the connection via a pipe:
3496 @example
3497 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3498 @end example
3499 ETEXI
3501 DEF("s", 0, QEMU_OPTION_s, \
3502 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3503 QEMU_ARCH_ALL)
3504 STEXI
3505 @item -s
3506 @findex -s
3507 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3508 (@pxref{gdb_usage}).
3509 ETEXI
3511 DEF("d", HAS_ARG, QEMU_OPTION_d, \
3512 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
3513 QEMU_ARCH_ALL)
3514 STEXI
3515 @item -d @var{item1}[,...]
3516 @findex -d
3517 Enable logging of specified items. Use '-d help' for a list of log items.
3518 ETEXI
3520 DEF("D", HAS_ARG, QEMU_OPTION_D, \
3521 "-D logfile output log to logfile (default stderr)\n",
3522 QEMU_ARCH_ALL)
3523 STEXI
3524 @item -D @var{logfile}
3525 @findex -D
3526 Output log in @var{logfile} instead of to stderr
3527 ETEXI
3529 DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3530 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3531 QEMU_ARCH_ALL)
3532 STEXI
3533 @item -dfilter @var{range1}[,...]
3534 @findex -dfilter
3535 Filter debug output to that relevant to a range of target addresses. The filter
3536 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3537 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3538 addresses and sizes required. For example:
3539 @example
3540 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3541 @end example
3542 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3543 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3544 block starting at 0xffffffc00005f000.
3545 ETEXI
3547 DEF("L", HAS_ARG, QEMU_OPTION_L, \
3548 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
3549 QEMU_ARCH_ALL)
3550 STEXI
3551 @item -L @var{path}
3552 @findex -L
3553 Set the directory for the BIOS, VGA BIOS and keymaps.
3555 To list all the data directories, use @code{-L help}.
3556 ETEXI
3558 DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3559 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
3560 STEXI
3561 @item -bios @var{file}
3562 @findex -bios
3563 Set the filename for the BIOS.
3564 ETEXI
3566 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3567 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3568 STEXI
3569 @item -enable-kvm
3570 @findex -enable-kvm
3571 Enable KVM full virtualization support. This option is only available
3572 if KVM support is enabled when compiling.
3573 ETEXI
3575 DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3576 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386)
3577 STEXI
3578 @item -enable-hax
3579 @findex -enable-hax
3580 Enable HAX (Hardware-based Acceleration eXecution) support. This option
3581 is only available if HAX support is enabled when compiling. HAX is only
3582 applicable to MAC and Windows platform, and thus does not conflict with
3583 KVM.
3584 ETEXI
3586 DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3587 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
3588 DEF("xen-create", 0, QEMU_OPTION_xen_create,
3589 "-xen-create create domain using xen hypercalls, bypassing xend\n"
3590 " warning: should not be used when xend is in use\n",
3591 QEMU_ARCH_ALL)
3592 DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3593 "-xen-attach attach to existing xen domain\n"
3594 " xend will use this when starting QEMU\n",
3595 QEMU_ARCH_ALL)
3596 DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3597 "-xen-domid-restrict restrict set of available xen operations\n"
3598 " to specified domain id. (Does not affect\n"
3599 " xenpv machine type).\n",
3600 QEMU_ARCH_ALL)
3601 STEXI
3602 @item -xen-domid @var{id}
3603 @findex -xen-domid
3604 Specify xen guest domain @var{id} (XEN only).
3605 @item -xen-create
3606 @findex -xen-create
3607 Create domain using xen hypercalls, bypassing xend.
3608 Warning: should not be used when xend is in use (XEN only).
3609 @item -xen-attach
3610 @findex -xen-attach
3611 Attach to existing xen domain.
3612 xend will use this when starting QEMU (XEN only).
3613 @findex -xen-domid-restrict
3614 Restrict set of available xen operations to specified domain id (XEN only).
3615 ETEXI
3617 DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3618 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
3619 STEXI
3620 @item -no-reboot
3621 @findex -no-reboot
3622 Exit instead of rebooting.
3623 ETEXI
3625 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3626 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
3627 STEXI
3628 @item -no-shutdown
3629 @findex -no-shutdown
3630 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3631 This allows for instance switching to monitor to commit changes to the
3632 disk image.
3633 ETEXI
3635 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3636 "-loadvm [tag|id]\n" \
3637 " start right away with a saved state (loadvm in monitor)\n",
3638 QEMU_ARCH_ALL)
3639 STEXI
3640 @item -loadvm @var{file}
3641 @findex -loadvm
3642 Start right away with a saved state (@code{loadvm} in monitor)
3643 ETEXI
3645 #ifndef _WIN32
3646 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3647 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3648 #endif
3649 STEXI
3650 @item -daemonize
3651 @findex -daemonize
3652 Daemonize the QEMU process after initialization. QEMU will not detach from
3653 standard IO until it is ready to receive connections on any of its devices.
3654 This option is a useful way for external programs to launch QEMU without having
3655 to cope with initialization race conditions.
3656 ETEXI
3658 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3659 "-option-rom rom load a file, rom, into the option ROM space\n",
3660 QEMU_ARCH_ALL)
3661 STEXI
3662 @item -option-rom @var{file}
3663 @findex -option-rom
3664 Load the contents of @var{file} as an option ROM.
3665 This option is useful to load things like EtherBoot.
3666 ETEXI
3668 HXCOMM Silently ignored for compatibility
3669 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3671 HXCOMM Options deprecated by -rtc
3672 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3673 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3675 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3676 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3677 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3678 QEMU_ARCH_ALL)
3680 STEXI
3682 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3683 @findex -rtc
3684 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3685 UTC or local time, respectively. @code{localtime} is required for correct date in
3686 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3687 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3689 By default the RTC is driven by the host system time. This allows using of the
3690 RTC as accurate reference clock inside the guest, specifically if the host
3691 time is smoothly following an accurate external reference clock, e.g. via NTP.
3692 If you want to isolate the guest time from the host, you can set @option{clock}
3693 to @code{rt} instead. To even prevent it from progressing during suspension,
3694 you can set it to @code{vm}.
3696 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3697 specifically with Windows' ACPI HAL. This option will try to figure out how
3698 many timer interrupts were not processed by the Windows guest and will
3699 re-inject them.
3700 ETEXI
3702 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3703 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3704 " enable virtual instruction counter with 2^N clock ticks per\n" \
3705 " instruction, enable aligning the host and virtual clocks\n" \
3706 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3707 STEXI
3708 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3709 @findex -icount
3710 Enable virtual instruction counter. The virtual cpu will execute one
3711 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3712 then the virtual cpu speed will be automatically adjusted to keep virtual
3713 time within a few seconds of real time.
3715 When the virtual cpu is sleeping, the virtual time will advance at default
3716 speed unless @option{sleep=on|off} is specified.
3717 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3718 instantly whenever the virtual cpu goes to sleep mode and will not advance
3719 if no timer is enabled. This behavior give deterministic execution times from
3720 the guest point of view.
3722 Note that while this option can give deterministic behavior, it does not
3723 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3724 order cores with complex cache hierarchies. The number of instructions
3725 executed often has little or no correlation with actual performance.
3727 @option{align=on} will activate the delay algorithm which will try
3728 to synchronise the host clock and the virtual clock. The goal is to
3729 have a guest running at the real frequency imposed by the shift option.
3730 Whenever the guest clock is behind the host clock and if
3731 @option{align=on} is specified then we print a message to the user
3732 to inform about the delay.
3733 Currently this option does not work when @option{shift} is @code{auto}.
3734 Note: The sync algorithm will work for those shift values for which
3735 the guest clock runs ahead of the host clock. Typically this happens
3736 when the shift value is high (how high depends on the host machine).
3738 When @option{rr} option is specified deterministic record/replay is enabled.
3739 Replay log is written into @var{filename} file in record mode and
3740 read from this file in replay mode.
3742 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3743 at the start of execution recording. In replay mode this option is used
3744 to load the initial VM state.
3745 ETEXI
3747 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3748 "-watchdog model\n" \
3749 " enable virtual hardware watchdog [default=none]\n",
3750 QEMU_ARCH_ALL)
3751 STEXI
3752 @item -watchdog @var{model}
3753 @findex -watchdog
3754 Create a virtual hardware watchdog device. Once enabled (by a guest
3755 action), the watchdog must be periodically polled by an agent inside
3756 the guest or else the guest will be restarted. Choose a model for
3757 which your guest has drivers.
3759 The @var{model} is the model of hardware watchdog to emulate. Use
3760 @code{-watchdog help} to list available hardware models. Only one
3761 watchdog can be enabled for a guest.
3763 The following models may be available:
3764 @table @option
3765 @item ib700
3766 iBASE 700 is a very simple ISA watchdog with a single timer.
3767 @item i6300esb
3768 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3769 dual-timer watchdog.
3770 @item diag288
3771 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3772 (currently KVM only).
3773 @end table
3774 ETEXI
3776 DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3777 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3778 " action when watchdog fires [default=reset]\n",
3779 QEMU_ARCH_ALL)
3780 STEXI
3781 @item -watchdog-action @var{action}
3782 @findex -watchdog-action
3784 The @var{action} controls what QEMU will do when the watchdog timer
3785 expires.
3786 The default is
3787 @code{reset} (forcefully reset the guest).
3788 Other possible actions are:
3789 @code{shutdown} (attempt to gracefully shutdown the guest),
3790 @code{poweroff} (forcefully poweroff the guest),
3791 @code{pause} (pause the guest),
3792 @code{debug} (print a debug message and continue), or
3793 @code{none} (do nothing).
3795 Note that the @code{shutdown} action requires that the guest responds
3796 to ACPI signals, which it may not be able to do in the sort of
3797 situations where the watchdog would have expired, and thus
3798 @code{-watchdog-action shutdown} is not recommended for production use.
3800 Examples:
3802 @table @code
3803 @item -watchdog i6300esb -watchdog-action pause
3804 @itemx -watchdog ib700
3805 @end table
3806 ETEXI
3808 DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3809 "-echr chr set terminal escape character instead of ctrl-a\n",
3810 QEMU_ARCH_ALL)
3811 STEXI
3813 @item -echr @var{numeric_ascii_value}
3814 @findex -echr
3815 Change the escape character used for switching to the monitor when using
3816 monitor and serial sharing. The default is @code{0x01} when using the
3817 @code{-nographic} option. @code{0x01} is equal to pressing
3818 @code{Control-a}. You can select a different character from the ascii
3819 control keys where 1 through 26 map to Control-a through Control-z. For
3820 instance you could use the either of the following to change the escape
3821 character to Control-t.
3822 @table @code
3823 @item -echr 0x14
3824 @itemx -echr 20
3825 @end table
3826 ETEXI
3828 DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3829 "-virtioconsole c\n" \
3830 " set virtio console\n", QEMU_ARCH_ALL)
3831 STEXI
3832 @item -virtioconsole @var{c}
3833 @findex -virtioconsole
3834 Set virtio console.
3836 This option is maintained for backward compatibility.
3838 Please use @code{-device virtconsole} for the new way of invocation.
3839 ETEXI
3841 DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3842 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
3843 STEXI
3844 @item -show-cursor
3845 @findex -show-cursor
3846 Show cursor.
3847 ETEXI
3849 DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3850 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
3851 STEXI
3852 @item -tb-size @var{n}
3853 @findex -tb-size
3854 Set TB size.
3855 ETEXI
3857 DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3858 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3859 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3860 "-incoming unix:socketpath\n" \
3861 " prepare for incoming migration, listen on\n" \
3862 " specified protocol and socket address\n" \
3863 "-incoming fd:fd\n" \
3864 "-incoming exec:cmdline\n" \
3865 " accept incoming migration on given file descriptor\n" \
3866 " or from given external command\n" \
3867 "-incoming defer\n" \
3868 " wait for the URI to be specified via migrate_incoming\n",
3869 QEMU_ARCH_ALL)
3870 STEXI
3871 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3872 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3873 @findex -incoming
3874 Prepare for incoming migration, listen on a given tcp port.
3876 @item -incoming unix:@var{socketpath}
3877 Prepare for incoming migration, listen on a given unix socket.
3879 @item -incoming fd:@var{fd}
3880 Accept incoming migration from a given filedescriptor.
3882 @item -incoming exec:@var{cmdline}
3883 Accept incoming migration as an output from specified external command.
3885 @item -incoming defer
3886 Wait for the URI to be specified via migrate_incoming. The monitor can
3887 be used to change settings (such as migration parameters) prior to issuing
3888 the migrate_incoming to allow the migration to begin.
3889 ETEXI
3891 DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3892 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
3893 STEXI
3894 @item -only-migratable
3895 @findex -only-migratable
3896 Only allow migratable devices. Devices will not be allowed to enter an
3897 unmigratable state.
3898 ETEXI
3900 DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3901 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
3902 STEXI
3903 @item -nodefaults
3904 @findex -nodefaults
3905 Don't create default devices. Normally, QEMU sets the default devices like serial
3906 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3907 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3908 default devices.
3909 ETEXI
3911 #ifndef _WIN32
3912 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3913 "-chroot dir chroot to dir just before starting the VM\n",
3914 QEMU_ARCH_ALL)
3915 #endif
3916 STEXI
3917 @item -chroot @var{dir}
3918 @findex -chroot
3919 Immediately before starting guest execution, chroot to the specified
3920 directory. Especially useful in combination with -runas.
3921 ETEXI
3923 #ifndef _WIN32
3924 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3925 "-runas user change to user id user just before starting the VM\n",
3926 QEMU_ARCH_ALL)
3927 #endif
3928 STEXI
3929 @item -runas @var{user}
3930 @findex -runas
3931 Immediately before starting guest execution, drop root privileges, switching
3932 to the specified user.
3933 ETEXI
3935 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3936 "-prom-env variable=value\n"
3937 " set OpenBIOS nvram variables\n",
3938 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3939 STEXI
3940 @item -prom-env @var{variable}=@var{value}
3941 @findex -prom-env
3942 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3943 ETEXI
3944 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3945 "-semihosting semihosting mode\n",
3946 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3947 QEMU_ARCH_MIPS)
3948 STEXI
3949 @item -semihosting
3950 @findex -semihosting
3951 Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3952 ETEXI
3953 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3954 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3955 " semihosting configuration\n",
3956 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3957 QEMU_ARCH_MIPS)
3958 STEXI
3959 @item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3960 @findex -semihosting-config
3961 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3962 @table @option
3963 @item target=@code{native|gdb|auto}
3964 Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3965 or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3966 during debug sessions and @code{native} otherwise.
3967 @item arg=@var{str1},arg=@var{str2},...
3968 Allows the user to pass input arguments, and can be used multiple times to build
3969 up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3970 command line is still supported for backward compatibility. If both the
3971 @code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3972 specified, the former is passed to semihosting as it always takes precedence.
3973 @end table
3974 ETEXI
3975 DEF("old-param", 0, QEMU_OPTION_old_param,
3976 "-old-param old param mode\n", QEMU_ARCH_ARM)
3977 STEXI
3978 @item -old-param
3979 @findex -old-param (ARM)
3980 Old param mode (ARM only).
3981 ETEXI
3983 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3984 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n",
3985 QEMU_ARCH_ALL)
3986 STEXI
3987 @item -sandbox @var{arg}
3988 @findex -sandbox
3989 Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3990 disable it. The default is 'off'.
3991 ETEXI
3993 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3994 "-readconfig <file>\n", QEMU_ARCH_ALL)
3995 STEXI
3996 @item -readconfig @var{file}
3997 @findex -readconfig
3998 Read device configuration from @var{file}. This approach is useful when you want to spawn
3999 QEMU process with many command line options but you don't want to exceed the command line
4000 character limit.
4001 ETEXI
4002 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
4003 "-writeconfig <file>\n"
4004 " read/write config file\n", QEMU_ARCH_ALL)
4005 STEXI
4006 @item -writeconfig @var{file}
4007 @findex -writeconfig
4008 Write device configuration to @var{file}. The @var{file} can be either filename to save
4009 command line and device configuration into file or dash @code{-}) character to print the
4010 output to stdout. This can be later used as input file for @code{-readconfig} option.
4011 ETEXI
4012 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
4013 "-nodefconfig\n"
4014 " do not load default config files at startup\n",
4015 QEMU_ARCH_ALL)
4016 STEXI
4017 @item -nodefconfig
4018 @findex -nodefconfig
4019 Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
4020 The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
4021 ETEXI
4022 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
4023 "-no-user-config\n"
4024 " do not load user-provided config files at startup\n",
4025 QEMU_ARCH_ALL)
4026 STEXI
4027 @item -no-user-config
4028 @findex -no-user-config
4029 The @code{-no-user-config} option makes QEMU not load any of the user-provided
4030 config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config
4031 files from @var{datadir}.
4032 ETEXI
4033 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
4034 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
4035 " specify tracing options\n",
4036 QEMU_ARCH_ALL)
4037 STEXI
4038 HXCOMM This line is not accurate, as some sub-options are backend-specific but
4039 HXCOMM HX does not support conditional compilation of text.
4040 @item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
4041 @findex -trace
4042 @include qemu-option-trace.texi
4043 ETEXI
4045 HXCOMM Internal use
4046 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
4047 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
4049 #ifdef __linux__
4050 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
4051 "-enable-fips enable FIPS 140-2 compliance\n",
4052 QEMU_ARCH_ALL)
4053 #endif
4054 STEXI
4055 @item -enable-fips
4056 @findex -enable-fips
4057 Enable FIPS 140-2 compliance mode.
4058 ETEXI
4060 HXCOMM Deprecated by -machine accel=tcg property
4061 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
4063 HXCOMM Deprecated by kvm-pit driver properties
4064 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
4065 "", QEMU_ARCH_I386)
4067 HXCOMM Deprecated (ignored)
4068 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
4070 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
4071 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
4073 HXCOMM Deprecated (ignored)
4074 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
4076 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
4077 "-msg timestamp[=on|off]\n"
4078 " change the format of messages\n"
4079 " on|off controls leading timestamps (default:on)\n",
4080 QEMU_ARCH_ALL)
4081 STEXI
4082 @item -msg timestamp[=on|off]
4083 @findex -msg
4084 prepend a timestamp to each log message.(default:on)
4085 ETEXI
4087 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
4088 "-dump-vmstate <file>\n"
4089 " Output vmstate information in JSON format to file.\n"
4090 " Use the scripts/vmstate-static-checker.py file to\n"
4091 " check for possible regressions in migration code\n"
4092 " by comparing two such vmstate dumps.\n",
4093 QEMU_ARCH_ALL)
4094 STEXI
4095 @item -dump-vmstate @var{file}
4096 @findex -dump-vmstate
4097 Dump json-encoded vmstate information for current machine type to file
4098 in @var{file}
4099 ETEXI
4101 STEXI
4102 @end table
4103 ETEXI
4104 DEFHEADING()
4105 DEFHEADING(Generic object creation)
4106 STEXI
4107 @table @option
4108 ETEXI
4110 DEF("object", HAS_ARG, QEMU_OPTION_object,
4111 "-object TYPENAME[,PROP1=VALUE1,...]\n"
4112 " create a new object of type TYPENAME setting properties\n"
4113 " in the order they are specified. Note that the 'id'\n"
4114 " property must be set. These objects are placed in the\n"
4115 " '/objects' path.\n",
4116 QEMU_ARCH_ALL)
4117 STEXI
4118 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
4119 @findex -object
4120 Create a new object of type @var{typename} setting properties
4121 in the order they are specified. Note that the 'id'
4122 property must be set. These objects are placed in the
4123 '/objects' path.
4125 @table @option
4127 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off}
4129 Creates a memory file backend object, which can be used to back
4130 the guest RAM with huge pages. The @option{id} parameter is a
4131 unique ID that will be used to reference this memory region
4132 when configuring the @option{-numa} argument. The @option{size}
4133 option provides the size of the memory region, and accepts
4134 common suffixes, eg @option{500M}. The @option{mem-path} provides
4135 the path to either a shared memory or huge page filesystem mount.
4136 The @option{share} boolean option determines whether the memory
4137 region is marked as private to QEMU, or shared. The latter allows
4138 a co-operating external process to access the QEMU memory region.
4140 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
4142 Creates a random number generator backend which obtains entropy from
4143 a device on the host. The @option{id} parameter is a unique ID that
4144 will be used to reference this entropy backend from the @option{virtio-rng}
4145 device. The @option{filename} parameter specifies which file to obtain
4146 entropy from and if omitted defaults to @option{/dev/random}.
4148 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4150 Creates a random number generator backend which obtains entropy from
4151 an external daemon running on the host. The @option{id} parameter is
4152 a unique ID that will be used to reference this entropy backend from
4153 the @option{virtio-rng} device. The @option{chardev} parameter is
4154 the unique ID of a character device backend that provides the connection
4155 to the RNG daemon.
4157 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4159 Creates a TLS anonymous credentials object, which can be used to provide
4160 TLS support on network backends. The @option{id} parameter is a unique
4161 ID which network backends will use to access the credentials. The
4162 @option{endpoint} is either @option{server} or @option{client} depending
4163 on whether the QEMU network backend that uses the credentials will be
4164 acting as a client or as a server. If @option{verify-peer} is enabled
4165 (the default) then once the handshake is completed, the peer credentials
4166 will be verified, though this is a no-op for anonymous credentials.
4168 The @var{dir} parameter tells QEMU where to find the credential
4169 files. For server endpoints, this directory may contain a file
4170 @var{dh-params.pem} providing diffie-hellman parameters to use
4171 for the TLS server. If the file is missing, QEMU will generate
4172 a set of DH parameters at startup. This is a computationally
4173 expensive operation that consumes random pool entropy, so it is
4174 recommended that a persistent set of parameters be generated
4175 upfront and saved.
4177 @item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off},passwordid=@var{id}
4179 Creates a TLS anonymous credentials object, which can be used to provide
4180 TLS support on network backends. The @option{id} parameter is a unique
4181 ID which network backends will use to access the credentials. The
4182 @option{endpoint} is either @option{server} or @option{client} depending
4183 on whether the QEMU network backend that uses the credentials will be
4184 acting as a client or as a server. If @option{verify-peer} is enabled
4185 (the default) then once the handshake is completed, the peer credentials
4186 will be verified. With x509 certificates, this implies that the clients
4187 must be provided with valid client certificates too.
4189 The @var{dir} parameter tells QEMU where to find the credential
4190 files. For server endpoints, this directory may contain a file
4191 @var{dh-params.pem} providing diffie-hellman parameters to use
4192 for the TLS server. If the file is missing, QEMU will generate
4193 a set of DH parameters at startup. This is a computationally
4194 expensive operation that consumes random pool entropy, so it is
4195 recommended that a persistent set of parameters be generated
4196 upfront and saved.
4198 For x509 certificate credentials the directory will contain further files
4199 providing the x509 certificates. The certificates must be stored
4200 in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4201 @var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4202 @var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4204 For the @var{server-key.pem} and @var{client-key.pem} files which
4205 contain sensitive private keys, it is possible to use an encrypted
4206 version by providing the @var{passwordid} parameter. This provides
4207 the ID of a previously created @code{secret} object containing the
4208 password for decryption.
4210 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4212 Interval @var{t} can't be 0, this filter batches the packet delivery: all
4213 packets arriving in a given interval on netdev @var{netdevid} are delayed
4214 until the end of the interval. Interval is in microseconds.
4215 @option{status} is optional that indicate whether the netfilter is
4216 on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4218 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4220 @option{all}: the filter is attached both to the receive and the transmit
4221 queue of the netdev (default).
4223 @option{rx}: the filter is attached to the receive queue of the netdev,
4224 where it will receive packets sent to the netdev.
4226 @option{tx}: the filter is attached to the transmit queue of the netdev,
4227 where it will receive packets sent by the netdev.
4229 @item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
4231 filter-mirror on netdev @var{netdevid},mirror net packet to chardev
4232 @var{chardevid}
4234 @item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},
4235 outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
4237 filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4238 @var{chardevid},and redirect indev's packet to filter.
4239 Create a filter-redirector we need to differ outdev id from indev id, id can not
4240 be the same. we can just use indev or outdev, but at least one of indev or outdev
4241 need to be specified.
4243 @item -object filter-rewriter,id=@var{id},netdev=@var{netdevid}[,queue=@var{all|rx|tx}]
4245 Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4246 secondary from primary to keep secondary tcp connection,and rewrite
4247 tcp packet to primary from secondary make tcp packet can be handled by
4248 client.
4250 usage:
4251 colo secondary:
4252 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4253 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4254 -object filter-rewriter,id=rew0,netdev=hn0,queue=all
4256 @item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4258 Dump the network traffic on netdev @var{dev} to the file specified by
4259 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4260 The file format is libpcap, so it can be analyzed with tools such as tcpdump
4261 or Wireshark.
4263 @item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},
4264 outdev=@var{chardevid}
4266 Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4267 secondary packet. If the packets are same, we will output primary
4268 packet to outdev@var{chardevid}, else we will notify colo-frame
4269 do checkpoint and send primary packet to outdev@var{chardevid}.
4271 we must use it with the help of filter-mirror and filter-redirector.
4273 @example
4275 primary:
4276 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4277 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4278 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4279 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4280 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4281 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4282 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4283 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4284 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4285 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4286 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4287 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4289 secondary:
4290 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4291 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4292 -chardev socket,id=red0,host=3.3.3.3,port=9003
4293 -chardev socket,id=red1,host=3.3.3.3,port=9004
4294 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4295 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4297 @end example
4299 If you want to know the detail of above command line, you can read
4300 the colo-compare git log.
4302 @item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4304 Creates a cryptodev backend which executes crypto opreation from
4305 the QEMU cipher APIS. The @var{id} parameter is
4306 a unique ID that will be used to reference this cryptodev backend from
4307 the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4308 which specify the queue number of cryptodev backend, the default of
4309 @var{queues} is 1.
4311 @example
4313 # qemu-system-x86_64 \
4314 [...] \
4315 -object cryptodev-backend-builtin,id=cryptodev0 \
4316 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4317 [...]
4318 @end example
4320 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4321 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4323 Defines a secret to store a password, encryption key, or some other sensitive
4324 data. The sensitive data can either be passed directly via the @var{data}
4325 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4326 parameter is insecure unless the sensitive data is encrypted.
4328 The sensitive data can be provided in raw format (the default), or base64.
4329 When encoded as JSON, the raw format only supports valid UTF-8 characters,
4330 so base64 is recommended for sending binary data. QEMU will convert from
4331 which ever format is provided to the format it needs internally. eg, an
4332 RBD password can be provided in raw format, even though it will be base64
4333 encoded when passed onto the RBD sever.
4335 For added protection, it is possible to encrypt the data associated with
4336 a secret using the AES-256-CBC cipher. Use of encryption is indicated
4337 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4338 parameter provides the ID of a previously defined secret that contains
4339 the AES-256 decryption key. This key should be 32-bytes long and be
4340 base64 encoded. The @var{iv} parameter provides the random initialization
4341 vector used for encryption of this particular secret and should be a
4342 base64 encrypted string of the 16-byte IV.
4344 The simplest (insecure) usage is to provide the secret inline
4346 @example
4348 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4350 @end example
4352 The simplest secure usage is to provide the secret via a file
4354 # echo -n "letmein" > mypasswd.txt
4355 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4357 For greater security, AES-256-CBC should be used. To illustrate usage,
4358 consider the openssl command line tool which can encrypt the data. Note
4359 that when encrypting, the plaintext must be padded to the cipher block
4360 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4362 First a master key needs to be created in base64 encoding:
4364 @example
4365 # openssl rand -base64 32 > key.b64
4366 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
4367 @end example
4369 Each secret to be encrypted needs to have a random initialization vector
4370 generated. These do not need to be kept secret
4372 @example
4373 # openssl rand -base64 16 > iv.b64
4374 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
4375 @end example
4377 The secret to be defined can now be encrypted, in this case we're
4378 telling openssl to base64 encode the result, but it could be left
4379 as raw bytes if desired.
4381 @example
4382 # SECRET=$(echo -n "letmein" |
4383 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4384 @end example
4386 When launching QEMU, create a master secret pointing to @code{key.b64}
4387 and specify that to be used to decrypt the user password. Pass the
4388 contents of @code{iv.b64} to the second secret
4390 @example
4391 # $QEMU \
4392 -object secret,id=secmaster0,format=base64,file=key.b64 \
4393 -object secret,id=sec0,keyid=secmaster0,format=base64,\
4394 data=$SECRET,iv=$(<iv.b64)
4395 @end example
4397 @end table
4399 ETEXI
4402 HXCOMM This is the last statement. Insert new options before this line!
4403 STEXI
4404 @end table
4405 ETEXI