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
7 HXCOMM HXCOMM can be used
for comments
, discarded from both texi and C
9 DEFHEADING(Standard options
:)
14 DEF("help", 0, QEMU_OPTION_h
,
15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL
)
22 DEF("version", 0, QEMU_OPTION_version
,
23 "-version display version information and exit\n", QEMU_ARCH_ALL
)
27 Display version information and exit
30 DEF("machine", HAS_ARG
, QEMU_OPTION_machine
, \
31 "-machine [type=]name[,prop[=value][,...]]\n"
32 " selects emulated machine ('-machine help' for list)\n"
33 " property accel=accel1[:accel2[:...]] selects accelerator\n"
34 " supported accelerators are kvm, xen, hax, hvf, whpx or tcg (default: tcg)\n"
35 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n"
36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
37 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n"
38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
39 " mem-merge=on|off controls memory merge support (default: on)\n"
40 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
44 " nvdimm=on|off controls NVDIMM support (default=off)\n"
45 " enforce-config-section=on|off enforce configuration section migration (default=off)\n"
46 " memory-encryption=@var{} memory encryption object to use (default=none)\n",
49 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
51 Select the emulated machine by @
var{name
}. Use @code
{-machine help
} to list
54 For architectures which aim to support live migration compatibility
55 across releases
, each release will introduce a
new versioned machine
56 type
. For example
, the
2.8.0 release introduced machine types
57 ``pc
-i440fx
-2.8'' and ``pc
-q35
-2.8'' for the x86_64
/i686 architectures
.
59 To allow live migration of guests from QEMU version
2.8.0, to QEMU
60 version
2.9.0, the
2.9.0 version must support the ``pc
-i440fx
-2.8''
61 and ``pc
-q35
-2.8'' machines too
. To allow users live migrating VMs
62 to skip multiple intermediate releases when upgrading
, new releases
63 of QEMU will support machine types from many previous versions
.
65 Supported machine properties are
:
67 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
68 This is used to enable an accelerator
. Depending on the target architecture
,
69 kvm
, xen
, hax
, hvf
, whpx or tcg can be available
. By
default, tcg is used
. If there is
70 more than one accelerator specified
, the next one is used
if the previous one
72 @item kernel_irqchip
=on|off
73 Controls
in-kernel irqchip support
for the chosen accelerator when available
.
74 @item gfx_passthru
=on|off
75 Enables IGD GFX passthrough support
for the chosen machine when available
.
76 @item vmport
=on|off|auto
77 Enables emulation of VMWare IO port
, for vmmouse etc
. auto says to select the
78 value based on accel
. For accel
=xen the
default is off otherwise the
default
80 @item kvm_shadow_mem
=size
81 Defines the size of the KVM shadow MMU
.
82 @item dump
-guest
-core
=on|off
83 Include guest memory
in a core dump
. The
default is on
.
84 @item mem
-merge
=on|off
85 Enables or disables memory merge support
. This feature
, when supported by
86 the host
, de
-duplicates identical memory pages among VMs instances
88 @item aes
-key
-wrap
=on|off
89 Enables or disables AES key wrapping support on s390
-ccw hosts
. This feature
90 controls whether AES wrapping keys will be created to allow
91 execution of AES cryptographic functions
. The
default is on
.
92 @item dea
-key
-wrap
=on|off
93 Enables or disables DEA key wrapping support on s390
-ccw hosts
. This feature
94 controls whether DEA wrapping keys will be created to allow
95 execution of DEA cryptographic functions
. The
default is on
.
97 Enables or disables NVDIMM support
. The
default is off
.
98 @item enforce
-config
-section
=on|off
99 If @option
{enforce
-config
-section
} is set to @
var{on
}, force migration
100 code to send configuration section even
if the machine
-type sets the
101 @option
{migration
.send
-configuration
} property to @
var{off
}.
102 NOTE
: this parameter is deprecated
. Please use @option
{-global
}
103 @option
{migration
.send
-configuration
}=@
var{on|off
} instead
.
104 @item memory
-encryption
=@
var{}
105 Memory encryption object to use
. The
default is none
.
109 HXCOMM Deprecated by
-machine
110 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
112 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
113 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
115 @item
-cpu @
var{model
}
117 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
120 DEF("accel", HAS_ARG
, QEMU_OPTION_accel
,
121 "-accel [accel=]accelerator[,thread=single|multi]\n"
122 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n"
123 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL
)
125 @item
-accel @
var{name
}[,prop
=@
var{value
}[,...]]
127 This is used to enable an accelerator
. Depending on the target architecture
,
128 kvm
, xen
, hax
, hvf
, whpx or tcg can be available
. By
default, tcg is used
. If there is
129 more than one accelerator specified
, the next one is used
if the previous one
132 @item thread
=single|multi
133 Controls number of TCG threads
. When the TCG is multi
-threaded there will be one
134 thread per vCPU therefor taking advantage of additional host cores
. The
default
135 is to enable multi
-threading where both the back
-end and front
-ends support it and
136 no incompatible TCG features have been
enabled (e
.g
. icount
/replay
).
140 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
141 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
142 " set the number of CPUs to 'n' [default=1]\n"
143 " maxcpus= maximum number of total cpus, including\n"
144 " offline CPUs for hotplug, etc\n"
145 " cores= number of CPU cores on one socket\n"
146 " threads= number of threads on one CPU core\n"
147 " sockets= number of discrete sockets in the system\n",
150 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
152 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
153 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
155 For the PC target
, the number of @
var{cores
} per socket
, the number
156 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
157 specified
. Missing values will be computed
. If any on the three values is
158 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
159 specifies the maximum number of hotpluggable CPUs
.
162 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
163 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
164 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
165 "-numa dist,src=source,dst=destination,val=distance\n"
166 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n",
169 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{firstcpu
}[-@
var{lastcpu
}]][,nodeid
=@
var{node
}]
170 @itemx
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{firstcpu
}[-@
var{lastcpu
}]][,nodeid
=@
var{node
}]
171 @itemx
-numa dist
,src
=@
var{source
},dst
=@
var{destination
},val
=@
var{distance
}
172 @itemx
-numa cpu
,node
-id
=@
var{node
}[,socket
-id
=@
var{x
}][,core
-id
=@
var{y
}][,thread
-id
=@
var{z
}]
174 Define a NUMA node and assign RAM and VCPUs to it
.
175 Set the NUMA distance from a source node to a destination node
.
177 Legacy VCPU assignment uses @samp
{cpus
} option where
178 @
var{firstcpu
} and @
var{lastcpu
} are CPU indexes
. Each
179 @samp
{cpus
} option represent a contiguous range of CPU indexes
180 (or a single VCPU
if @
var{lastcpu
} is omitted
). A non
-contiguous
181 set of VCPUs can be represented by providing multiple @samp
{cpus
}
182 options
. If @samp
{cpus
} is omitted on all nodes
, VCPUs are automatically
185 For example
, the following option assigns VCPUs
0, 1, 2 and
5 to
188 -numa node
,cpus
=0-2,cpus
=5
191 @samp
{cpu
} option is a
new alternative to @samp
{cpus
} option
192 which uses @samp
{socket
-id|core
-id|thread
-id
} properties to assign
193 CPU objects to a @
var{node
} using topology layout properties of CPU
.
194 The set of properties is machine specific
, and depends on used
195 machine type
/@samp
{smp
} options
. It could be queried with
196 @samp
{hotpluggable
-cpus
} monitor command
.
197 @samp
{node
-id
} property specifies @
var{node
} to which CPU object
198 will be assigned
, it
's required for @var{node} to be declared
199 with @samp{node} option before it's used with @samp
{cpu
} option
.
204 -smp
1,sockets
=2,maxcpus
=2 \
205 -numa node
,nodeid
=0 -numa node
,nodeid
=1 \
206 -numa cpu
,node
-id
=0,socket
-id
=0 -numa cpu
,node
-id
=1,socket
-id
=1
209 @samp
{mem
} assigns a given RAM amount to a node
. @samp
{memdev
}
210 assigns RAM from a given memory backend device to a node
. If
211 @samp
{mem
} and @samp
{memdev
} are omitted
in all nodes
, RAM is
212 split equally between them
.
214 @samp
{mem
} and @samp
{memdev
} are mutually exclusive
. Furthermore
,
215 if one node uses @samp
{memdev
}, all of them have to use it
.
217 @
var{source
} and @
var{destination
} are NUMA node IDs
.
218 @
var{distance
} is the NUMA distance from @
var{source
} to @
var{destination
}.
219 The distance from a node to itself is always
10. If any pair of nodes is
220 given a distance
, then all pairs must be given distances
. Although
, when
221 distances are only given
in one direction
for each pair of nodes
, then
222 the distances
in the opposite directions are assumed to be the same
. If
,
223 however
, an asymmetrical pair of distances is given
for even one node
224 pair
, then all node pairs must be provided distance values
for both
225 directions
, even when they are symmetrical
. When a node is unreachable
226 from another node
, set the pair
's distance to 255.
228 Note that the -@option{numa} option doesn't allocate any of the
229 specified resources
, it just assigns existing resources to NUMA
230 nodes
. This means that one still has to use the @option
{-m
},
231 @option
{-smp
} options to allocate RAM and VCPUs respectively
.
235 DEF("add-fd", HAS_ARG
, QEMU_OPTION_add_fd
,
236 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
237 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL
)
239 @item
-add
-fd fd
=@
var{fd
},set
=@
var{set
}[,opaque
=@
var{opaque
}]
242 Add a file descriptor to an fd set
. Valid options are
:
246 This option defines the file descriptor of which a duplicate is added to fd set
.
247 The file descriptor cannot be stdin
, stdout
, or stderr
.
249 This option defines the ID of the fd set to add the file descriptor to
.
250 @item opaque
=@
var{opaque
}
251 This option defines a free
-form string that can be used to describe @
var{fd
}.
254 You can open an image
using pre
-opened file descriptors from an fd set
:
257 -add
-fd fd
=3,set
=2,opaque
="rdwr:/path/to/file"
258 -add
-fd fd
=4,set
=2,opaque
="rdonly:/path/to/file"
259 -drive file
=/dev
/fdset
/2,index
=0,media
=disk
263 DEF("set", HAS_ARG
, QEMU_OPTION_set
,
264 "-set group.id.arg=value\n"
265 " set <arg> parameter for item <id> of type <group>\n"
266 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL
)
268 @item
-set @
var{group
}.@
var{id
}.@
var{arg
}=@
var{value
}
270 Set parameter @
var{arg
} for item @
var{id
} of type @
var{group
}
273 DEF("global", HAS_ARG
, QEMU_OPTION_global
,
274 "-global driver.property=value\n"
275 "-global driver=driver,property=property,value=value\n"
276 " set a global default for a driver property\n",
279 @item
-global @
var{driver
}.@
var{prop
}=@
var{value
}
280 @itemx
-global driver
=@
var{driver
},property
=@
var{property
},value
=@
var{value
}
282 Set
default value of @
var{driver
}'s property @var{prop} to @var{value}, e.g.:
285 qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
288 In particular, you can use this to set driver properties for devices which are
289 created automatically by the machine model. To create a device which is not
290 created automatically and set properties on it, use -@option{device}.
292 -global @var{driver}.@var{prop}=@var{value} is shorthand for -global
293 driver=@var{driver},property=@var{prop},value=@var{value}. The
294 longhand syntax works even when @var{driver} contains a dot.
297 DEF("boot", HAS_ARG, QEMU_OPTION_boot,
298 "-boot [order=drives][,once=drives][,menu=on|off]\n"
299 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
300 " 'drives
': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
301 " 'sp_name
': the file's name that would be passed to bios as logo picture
, if menu
=on
\n"
302 " 'sp_time': the period that splash picture last
if menu
=on
, unit is ms
\n"
303 " 'rb_timeout': the timeout before guest reboot when boot failed
, unit is ms
\n",
306 @item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}][,reboot-timeout=@var{rb_timeout}][,strict=on|off]
308 Specify boot order @var{drives} as a string of drive letters. Valid
309 drive letters depend on the target architecture. The x86 PC uses: a, b
310 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
311 from network adapter 1-4), hard disk boot is the default. To apply a
312 particular boot order only on the first startup, specify it via
313 @option{once}. Note that the @option{order} or @option{once} parameter
314 should not be used together with the @option{bootindex} property of
315 devices, since the firmware implementations normally do not support both
318 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
319 as firmware/BIOS supports them. The default is non-interactive boot.
321 A splash picture could be passed to bios, enabling user to show it as logo,
322 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
323 supports them. Currently Seabios for X86 system support it.
324 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
325 format(true color). The resolution should be supported by the SVGA mode, so
326 the recommended is 320x240, 640x480, 800x640.
328 A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
329 when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
330 reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
333 Do strict boot via @option{strict=on} as far as firmware/BIOS
334 supports it. This only effects when boot priority is changed by
335 bootindex options. The default is non-strict boot.
338 # try to boot from network first, then from hard disk
339 qemu-system-i386 -boot order=nc
340 # boot from CD-ROM first, switch back to default order after reboot
341 qemu-system-i386 -boot once=d
342 # boot with a splash picture for 5 seconds.
343 qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
346 Note: The legacy format '-boot @var{drives}' is still supported but its
347 use is discouraged as it may be removed from future versions.
350 DEF("m
", HAS_ARG, QEMU_OPTION_m,
351 "-m
[size
=]megs
[,slots
=n
,maxmem
=size
]\n"
352 " configure guest RAM
\n"
353 " size
: initial amount of guest memory
\n"
354 " slots
: number of hotplug
slots (default: none
)\n"
355 " maxmem
: maximum amount of guest
memory (default: none
)\n"
356 "NOTE
: Some architectures might enforce a specific granularity
\n",
359 @item -m [size=]@var{megs}[,slots=n,maxmem=size]
361 Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
362 Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
363 megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
364 could be used to set amount of hotpluggable memory slots and maximum amount of
365 memory. Note that @var{maxmem} must be aligned to the page size.
367 For example, the following command-line sets the guest startup RAM size to
368 1GB, creates 3 slots to hotplug additional memory and sets the maximum
369 memory the guest can reach to 4GB:
372 qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
375 If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
376 be enabled and the guest startup RAM will never increase.
379 DEF("mem
-path
", HAS_ARG, QEMU_OPTION_mempath,
380 "-mem
-path FILE provide backing storage
for guest RAM
\n", QEMU_ARCH_ALL)
382 @item -mem-path @var{path}
384 Allocate guest RAM from a temporarily created file in @var{path}.
387 DEF("mem
-prealloc
", 0, QEMU_OPTION_mem_prealloc,
388 "-mem
-prealloc preallocate guest
memory (use with
-mem
-path
)\n",
392 @findex -mem-prealloc
393 Preallocate memory when using -mem-path.
396 DEF("k
", HAS_ARG, QEMU_OPTION_k,
397 "-k language use keyboard
layout (for example
'fr' for French
)\n",
400 @item -k @var{language}
402 Use keyboard layout @var{language} (for example @code{fr} for
403 French). This option is only needed where it is not easy to get raw PC
404 keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
405 display). You don't normally need to use it on PC/Linux or PC/Windows
408 The available layouts are:
410 ar de-ch es fo fr-ca hu ja mk no pt-br sv
411 da en-gb et fr fr-ch is lt nl pl ru th
412 de en-us fi fr-be hr it lv nl-be pt sl tr
415 The default is @code{en-us}.
419 HXCOMM Deprecated by -audiodev
420 DEF("audio
-help
", 0, QEMU_OPTION_audio_help,
421 "-audio
-help show
-audiodev equivalent of the currently specified audio settings
\n",
426 Will show the -audiodev equivalent of the currently specified
427 (deprecated) environment variables.
430 DEF("audiodev
", HAS_ARG, QEMU_OPTION_audiodev,
431 "-audiodev
[driver
=]driver
,id
=id
[,prop
[=value
][,...]]\n"
432 " specifies the audio backend to use
\n"
433 " id
= identifier of the backend
\n"
434 " timer
-period
= timer period
in microseconds
\n"
435 " in|out
.fixed
-settings
= use fixed settings
for host audio
\n"
436 " in|out
.frequency
= frequency to use with fixed settings
\n"
437 " in|out
.channels
= number of channels to use with fixed settings
\n"
438 " in|out
.format
= sample format to use with fixed settings
\n"
439 " valid values
: s8
, s16
, s32
, u8
, u16
, u32
\n"
440 " in|out
.voices
= number of voices to use
\n"
441 " in|out
.buffer
-len
= length of buffer
in microseconds
\n"
442 "-audiodev none
,id
=id
,[,prop
[=value
][,...]]\n"
443 " dummy driver that discards all output
\n"
444 #ifdef CONFIG_AUDIO_ALSA
445 "-audiodev alsa
,id
=id
[,prop
[=value
][,...]]\n"
446 " in|out
.dev
= name of the audio device to use
\n"
447 " in|out
.period
-len
= length of period
in microseconds
\n"
448 " in|out
.try-poll
= attempt to use poll mode
\n"
449 " threshold
= threshold (in microseconds
) when playback starts
\n"
451 #ifdef CONFIG_AUDIO_COREAUDIO
452 "-audiodev coreaudio
,id
=id
[,prop
[=value
][,...]]\n"
453 " in|out
.buffer
-count
= number of buffers
\n"
455 #ifdef CONFIG_AUDIO_DSOUND
456 "-audiodev dsound
,id
=id
[,prop
[=value
][,...]]\n"
457 " latency
= add extra latency to playback
in microseconds
\n"
459 #ifdef CONFIG_AUDIO_OSS
460 "-audiodev oss
,id
=id
[,prop
[=value
][,...]]\n"
461 " in|out
.dev
= path of the audio device to use
\n"
462 " in|out
.buffer
-count
= number of buffers
\n"
463 " in|out
.try-poll
= attempt to use poll mode
\n"
464 " try-mmap
= try using memory mapped access
\n"
465 " exclusive
= open device
in exclusive mode
\n"
466 " dsp
-policy
= set timing
policy (0..10), -1 to use fragment mode
\n"
468 #ifdef CONFIG_AUDIO_PA
469 "-audiodev pa
,id
=id
[,prop
[=value
][,...]]\n"
470 " server
= PulseAudio server address
\n"
471 " in|out
.name
= source
/sink device name
\n"
473 #ifdef CONFIG_AUDIO_SDL
474 "-audiodev sdl
,id
=id
[,prop
[=value
][,...]]\n"
477 "-audiodev spice
,id
=id
[,prop
[=value
][,...]]\n"
479 "-audiodev wav
,id
=id
[,prop
[=value
][,...]]\n"
480 " path
= path of wav file to record
\n",
483 @item -audiodev [driver=]@var{driver},id=@var{id}[,@var{prop}[=@var{value}][,...]]
485 Adds a new audio backend @var{driver} identified by @var{id}. There are
486 global and driver specific properties. Some values can be set
487 differently for input and output, they're marked with @code{in|out.}.
488 You can set the input's property with @code{in.@var{prop}} and the
489 output's property with @code{out.@var{prop}}. For example:
491 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000
492 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified
495 Valid global options are:
498 @item id=@var{identifier}
499 Identifies the audio backend.
501 @item timer-period=@var{period}
502 Sets the timer @var{period} used by the audio subsystem in microseconds.
503 Default is 10000 (10 ms).
505 @item in|out.fixed-settings=on|off
506 Use fixed settings for host audio. When off, it will change based on
507 how the guest opens the sound card. In this case you must not specify
508 @var{frequency}, @var{channels} or @var{format}. Default is on.
510 @item in|out.frequency=@var{frequency}
511 Specify the @var{frequency} to use when using @var{fixed-settings}.
514 @item in|out.channels=@var{channels}
515 Specify the number of @var{channels} to use when using
516 @var{fixed-settings}. Default is 2 (stereo).
518 @item in|out.format=@var{format}
519 Specify the sample @var{format} to use when using @var{fixed-settings}.
520 Valid values are: @code{s8}, @code{s16}, @code{s32}, @code{u8},
521 @code{u16}, @code{u32}. Default is @code{s16}.
523 @item in|out.voices=@var{voices}
524 Specify the number of @var{voices} to use. Default is 1.
526 @item in|out.buffer=@var{usecs}
527 Sets the size of the buffer in microseconds.
531 @item -audiodev none,id=@var{id}[,@var{prop}[=@var{value}][,...]]
532 Creates a dummy backend that discards all outputs. This backend has no
533 backend specific properties.
535 @item -audiodev alsa,id=@var{id}[,@var{prop}[=@var{value}][,...]]
536 Creates backend using the ALSA. This backend is only available on
539 ALSA specific options are:
543 @item in|out.dev=@var{device}
544 Specify the ALSA @var{device} to use for input and/or output. Default
547 @item in|out.period-len=@var{usecs}
548 Sets the period length in microseconds.
550 @item in|out.try-poll=on|off
551 Attempt to use poll mode with the device. Default is on.
553 @item threshold=@var{threshold}
554 Threshold (in microseconds) when playback starts. Default is 0.
558 @item -audiodev coreaudio,id=@var{id}[,@var{prop}[=@var{value}][,...]]
559 Creates a backend using Apple's Core Audio. This backend is only
560 available on Mac OS and only supports playback.
562 Core Audio specific options are:
566 @item in|out.buffer-count=@var{count}
567 Sets the @var{count} of the buffers.
571 @item -audiodev dsound,id=@var{id}[,@var{prop}[=@var{value}][,...]]
572 Creates a backend using Microsoft's DirectSound. This backend is only
573 available on Windows and only supports playback.
575 DirectSound specific options are:
579 @item latency=@var{usecs}
580 Add extra @var{usecs} microseconds latency to playback. Default is
585 @item -audiodev oss,id=@var{id}[,@var{prop}[=@var{value}][,...]]
586 Creates a backend using OSS. This backend is available on most
589 OSS specific options are:
593 @item in|out.dev=@var{device}
594 Specify the file name of the OSS @var{device} to use. Default is
597 @item in|out.buffer-count=@var{count}
598 Sets the @var{count} of the buffers.
600 @item in|out.try-poll=on|of
601 Attempt to use poll mode with the device. Default is on.
603 @item try-mmap=on|off
604 Try using memory mapped device access. Default is off.
606 @item exclusive=on|off
607 Open the device in exclusive mode (vmix won't work in this case).
610 @item dsp-policy=@var{policy}
611 Sets the timing policy (between 0 and 10, where smaller number means
612 smaller latency but higher CPU usage). Use -1 to use buffer sizes
613 specified by @code{buffer} and @code{buffer-count}. This option is
614 ignored if you do not have OSS 4. Default is 5.
618 @item -audiodev pa,id=@var{id}[,@var{prop}[=@var{value}][,...]]
619 Creates a backend using PulseAudio. This backend is available on most
622 PulseAudio specific options are:
626 @item server=@var{server}
627 Sets the PulseAudio @var{server} to connect to.
629 @item in|out.name=@var{sink}
630 Use the specified source/sink for recording/playback.
634 @item -audiodev sdl,id=@var{id}[,@var{prop}[=@var{value}][,...]]
635 Creates a backend using SDL. This backend is available on most systems,
636 but you should use your platform's native backend if possible. This
637 backend has no backend specific properties.
639 @item -audiodev spice,id=@var{id}[,@var{prop}[=@var{value}][,...]]
640 Creates a backend that sends audio through SPICE. This backend requires
641 @code{-spice} and automatically selected in that case, so usually you
642 can ignore this option. This backend has no backend specific
645 @item -audiodev wav,id=@var{id}[,@var{prop}[=@var{value}][,...]]
646 Creates a backend that writes audio to a WAV file.
648 Backend specific options are:
652 @item path=@var{path}
653 Write recorded audio into the specified file. Default is
659 DEF("soundhw
", HAS_ARG, QEMU_OPTION_soundhw,
660 "-soundhw c1
,... enable audio support
\n"
661 " and only specified sound
cards (comma separated list
)\n"
662 " use
'-soundhw help' to get the list of supported cards
\n"
663 " use
'-soundhw all' to enable all of them
\n", QEMU_ARCH_ALL)
665 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
667 Enable audio and selected sound hardware. Use 'help' to print all
668 available sound hardware.
671 qemu-system-i386 -soundhw sb16,adlib disk.img
672 qemu-system-i386 -soundhw es1370 disk.img
673 qemu-system-i386 -soundhw ac97 disk.img
674 qemu-system-i386 -soundhw hda disk.img
675 qemu-system-i386 -soundhw all disk.img
676 qemu-system-i386 -soundhw help
679 Note that Linux's i810_audio OSS kernel (for AC97) module might
680 require manually specifying clocking.
683 modprobe i810_audio clocking=48000
687 DEF("device
", HAS_ARG, QEMU_OPTION_device,
688 "-device driver
[,prop
[=value
][,...]]\n"
689 " add
device (based on driver
)\n"
690 " prop
=value
,... sets driver properties
\n"
691 " use
'-device help' to print all possible drivers
\n"
692 " use
'-device driver,help' to print all possible properties
\n",
695 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
697 Add device @var{driver}. @var{prop}=@var{value} sets driver
698 properties. Valid properties depend on the driver. To get help on
699 possible drivers and properties, use @code{-device help} and
700 @code{-device @var{driver},help}.
703 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
705 Add an IPMI BMC. This is a simulation of a hardware management
706 interface processor that normally sits on a system. It provides
707 a watchdog and the ability to reset and power control the system.
708 You need to connect this to an IPMI interface to make it useful
710 The IPMI slave address to use for the BMC. The default is 0x20.
711 This address is the BMC's address on the I2C network of management
712 controllers. If you don't know what this means, it is safe to ignore
717 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
718 @item slave_addr=@var{val}
719 Define slave address to use for the BMC. The default is 0x20.
720 @item sdrfile=@var{file}
721 file containing raw Sensor Data Records (SDR) data. The default is none.
722 @item fruareasize=@var{val}
723 size of a Field Replaceable Unit (FRU) area. The default is 1024.
724 @item frudatafile=@var{file}
725 file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
728 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
730 Add a connection to an external IPMI BMC simulator. Instead of
731 locally emulating the BMC like the above item, instead connect
732 to an external entity that provides the IPMI services.
734 A connection is made to an external BMC simulator. If you do this, it
735 is strongly recommended that you use the "reconnect
=" chardev option
736 to reconnect to the simulator if the connection is lost. Note that if
737 this is not used carefully, it can be a security issue, as the
738 interface has the ability to send resets, NMIs, and power off the VM.
739 It's best if QEMU makes a connection to an external simulator running
740 on a secure port on localhost, so neither the simulator nor QEMU is
741 exposed to any outside network.
743 See the "lanserv
/README
.vm
" file in the OpenIPMI library for more
744 details on the external interface.
746 @item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
748 Add a KCS IPMI interafce on the ISA bus. This also adds a
749 corresponding ACPI and SMBIOS entries, if appropriate.
753 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
754 @item ioport=@var{val}
755 Define the I/O address of the interface. The default is 0xca0 for KCS.
757 Define the interrupt to use. The default is 5. To disable interrupts,
761 @item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
763 Like the KCS interface, but defines a BT interface. The default port is
764 0xe4 and the default interrupt is 5.
768 DEF("name
", HAS_ARG, QEMU_OPTION_name,
769 "-name string1
[,process
=string2
][,debug
-threads
=on|off
]\n"
770 " set the name of the guest
\n"
771 " string1 sets the window title and string2 the process name
\n"
772 " When debug
-threads is enabled
, individual threads are given a separate name
\n"
773 " NOTE
: The thread names are
for debugging and not a stable API
.\n",
776 @item -name @var{name}
778 Sets the @var{name} of the guest.
779 This name will be displayed in the SDL window caption.
780 The @var{name} will also be used for the VNC server.
781 Also optionally set the top visible process name in Linux.
782 Naming of individual threads can also be enabled on Linux to aid debugging.
785 DEF("uuid
", HAS_ARG, QEMU_OPTION_uuid,
786 "-uuid
%08x
-%04x
-%04x
-%04x
-%012x
\n"
787 " specify machine UUID
\n", QEMU_ARCH_ALL)
789 @item -uuid @var{uuid}
799 DEFHEADING(Block device options:)
804 DEF("fda
", HAS_ARG, QEMU_OPTION_fda,
805 "-fda
/-fdb file use
'file' as floppy disk
0/1 image
\n", QEMU_ARCH_ALL)
806 DEF("fdb
", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
808 @item -fda @var{file}
809 @itemx -fdb @var{file}
812 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
815 DEF("hda
", HAS_ARG, QEMU_OPTION_hda,
816 "-hda
/-hdb file use
'file' as IDE hard disk
0/1 image
\n", QEMU_ARCH_ALL)
817 DEF("hdb
", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
818 DEF("hdc
", HAS_ARG, QEMU_OPTION_hdc,
819 "-hdc
/-hdd file use
'file' as IDE hard disk
2/3 image
\n", QEMU_ARCH_ALL)
820 DEF("hdd
", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
822 @item -hda @var{file}
823 @itemx -hdb @var{file}
824 @itemx -hdc @var{file}
825 @itemx -hdd @var{file}
830 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
833 DEF("cdrom
", HAS_ARG, QEMU_OPTION_cdrom,
834 "-cdrom file use
'file' as IDE cdrom
image (cdrom is ide1 master
)\n",
837 @item -cdrom @var{file}
839 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
840 @option{-cdrom} at the same time). You can use the host CD-ROM by
841 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
844 DEF("blockdev
", HAS_ARG, QEMU_OPTION_blockdev,
845 "-blockdev
[driver
=]driver
[,node
-name
=N
][,discard
=ignore|unmap
]\n"
846 " [,cache
.direct
=on|off
][,cache
.no
-flush
=on|off
]\n"
847 " [,read
-only
=on|off
][,detect
-zeroes
=on|off|unmap
]\n"
848 " [,driver specific parameters
...]\n"
849 " configure a block backend
\n", QEMU_ARCH_ALL)
851 @item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
854 Define a new block driver node. Some of the options apply to all block drivers,
855 other options are only accepted for a specific block driver. See below for a
856 list of generic options and options for the most common block drivers.
858 Options that expect a reference to another node (e.g. @code{file}) can be
859 given in two ways. Either you specify the node name of an already existing node
860 (file=@var{node-name}), or you define a new node inline, adding options
861 for the referenced node after a dot (file.filename=@var{path},file.aio=native).
863 A block driver node created with @option{-blockdev} can be used for a guest
864 device by specifying its node name for the @code{drive} property in a
865 @option{-device} argument that defines a block device.
868 @item Valid options for any block driver node:
872 Specifies the block driver to use for the given node.
874 This defines the name of the block driver node by which it will be referenced
875 later. The name must be unique, i.e. it must not match the name of a different
876 block driver node, or (if you use @option{-drive} as well) the ID of a drive.
878 If no node name is specified, it is automatically generated. The generated node
879 name is not intended to be predictable and changes between QEMU invocations.
880 For the top level, an explicit node name must be specified.
882 Open the node read-only. Guest write attempts will fail.
884 The host page cache can be avoided with @option{cache.direct=on}. This will
885 attempt to do disk IO directly to the guest's memory. QEMU may still perform an
886 internal copy of the data.
888 In case you don't care about data integrity over host failures, you can use
889 @option{cache.no-flush=on}. This option tells QEMU that it never needs to write
890 any data to the disk but can instead keep things in cache. If anything goes
891 wrong, like your host losing power, the disk storage getting disconnected
892 accidentally, etc. your image will most probably be rendered unusable.
893 @item discard=@var{discard}
894 @var{discard} is one of "ignore
" (or "off
") or "unmap
" (or "on
") and controls
895 whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
896 ignored or passed to the filesystem. Some machine types may not support
898 @item detect-zeroes=@var{detect-zeroes}
899 @var{detect-zeroes} is "off
", "on
" or "unmap
" and enables the automatic
900 conversion of plain zero writes by the OS to driver specific optimized
901 zero write commands. You may even choose "unmap
" if @var{discard} is set
902 to "unmap
" to allow a zero write to be converted to an @code{unmap} operation.
905 @item Driver-specific options for @code{file}
907 This is the protocol-level block driver for accessing regular files.
911 The path to the image file in the local filesystem
913 Specifies the AIO backend (threads/native, default: threads)
915 Specifies whether the image file is protected with Linux OFD / POSIX locks. The
916 default is to use the Linux Open File Descriptor API if available, otherwise no
917 lock is applied. (auto/on/off, default: auto)
921 -blockdev driver=file,node-name=disk,filename=disk.img
924 @item Driver-specific options for @code{raw}
926 This is the image format block driver for raw images. It is usually
927 stacked on top of a protocol level block driver such as @code{file}.
931 Reference to or definition of the data source block driver node
932 (e.g. a @code{file} driver node)
936 -blockdev driver=file,node-name=disk_file,filename=disk.img
937 -blockdev driver=raw,node-name=disk,file=disk_file
941 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
944 @item Driver-specific options for @code{qcow2}
946 This is the image format block driver for qcow2 images. It is usually
947 stacked on top of a protocol level block driver such as @code{file}.
951 Reference to or definition of the data source block driver node
952 (e.g. a @code{file} driver node)
955 Reference to or definition of the backing file block device (default is taken
956 from the image file). It is allowed to pass @code{null} here in order to disable
957 the default backing file.
960 Whether to enable the lazy refcounts feature (on/off; default is taken from the
964 The maximum total size of the L2 table and refcount block caches in bytes
965 (default: the sum of l2-cache-size and refcount-cache-size)
968 The maximum size of the L2 table cache in bytes
969 (default: if cache-size is not specified - 32M on Linux platforms, and 8M on
970 non-Linux platforms; otherwise, as large as possible within the cache-size,
971 while permitting the requested or the minimal refcount cache size)
973 @item refcount-cache-size
974 The maximum size of the refcount block cache in bytes
975 (default: 4 times the cluster size; or if cache-size is specified, the part of
976 it which is not used for the L2 cache)
978 @item cache-clean-interval
979 Clean unused entries in the L2 and refcount caches. The interval is in seconds.
980 The default value is 600 on supporting platforms, and 0 on other platforms.
981 Setting it to 0 disables this feature.
983 @item pass-discard-request
984 Whether discard requests to the qcow2 device should be forwarded to the data
985 source (on/off; default: on if discard=unmap is specified, off otherwise)
987 @item pass-discard-snapshot
988 Whether discard requests for the data source should be issued when a snapshot
989 operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
992 @item pass-discard-other
993 Whether discard requests for the data source should be issued on other
994 occasions where a cluster gets freed (on/off; default: off)
997 Which overlap checks to perform for writes to the image
998 (none/constant/cached/all; default: cached). For details or finer
999 granularity control refer to the QAPI documentation of @code{blockdev-add}.
1004 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
1005 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
1009 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
1012 @item Driver-specific options for other drivers
1013 Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
1019 DEF("drive
", HAS_ARG, QEMU_OPTION_drive,
1020 "-drive
[file
=file
][,if=type
][,bus
=n
][,unit
=m
][,media
=d
][,index
=i
]\n"
1021 " [,cache
=writethrough|writeback|none|directsync|unsafe
][,format
=f
]\n"
1022 " [,snapshot
=on|off
][,rerror
=ignore|stop|report
]\n"
1023 " [,werror
=ignore|stop|report|enospc
][,id
=name
][,aio
=threads|native
]\n"
1024 " [,readonly
=on|off
][,copy
-on
-read
=on|off
]\n"
1025 " [,discard
=ignore|unmap
][,detect
-zeroes
=on|off|unmap
]\n"
1026 " [[,bps
=b
]|
[[,bps_rd
=r
][,bps_wr
=w
]]]\n"
1027 " [[,iops
=i
]|
[[,iops_rd
=r
][,iops_wr
=w
]]]\n"
1028 " [[,bps_max
=bm
]|
[[,bps_rd_max
=rm
][,bps_wr_max
=wm
]]]\n"
1029 " [[,iops_max
=im
]|
[[,iops_rd_max
=irm
][,iops_wr_max
=iwm
]]]\n"
1030 " [[,iops_size
=is
]]\n"
1032 " use
'file' as a drive image
\n", QEMU_ARCH_ALL)
1034 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
1037 Define a new drive. This includes creating a block driver node (the backend) as
1038 well as a guest device, and is mostly a shortcut for defining the corresponding
1039 @option{-blockdev} and @option{-device} options.
1041 @option{-drive} accepts all options that are accepted by @option{-blockdev}. In
1042 addition, it knows the following options:
1045 @item file=@var{file}
1046 This option defines which disk image (@pxref{disk_images}) to use with
1047 this drive. If the filename contains comma, you must double it
1048 (for instance, "file
=my
,,file
" to use file "my
,file
").
1050 Special files such as iSCSI devices can be specified using protocol
1051 specific URLs. See the section for "Device URL Syntax
" for more information.
1052 @item if=@var{interface}
1053 This option defines on which type on interface the drive is connected.
1054 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
1055 @item bus=@var{bus},unit=@var{unit}
1056 These options define where is connected the drive by defining the bus number and
1058 @item index=@var{index}
1059 This option defines where is connected the drive by using an index in the list
1060 of available connectors of a given interface type.
1061 @item media=@var{media}
1062 This option defines the type of the media: disk or cdrom.
1063 @item snapshot=@var{snapshot}
1064 @var{snapshot} is "on
" or "off
" and controls snapshot mode for the given drive
1065 (see @option{-snapshot}).
1066 @item cache=@var{cache}
1067 @var{cache} is "none
", "writeback
", "unsafe
", "directsync
" or "writethrough
"
1068 and controls how the host cache is used to access block data. This is a
1069 shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
1070 options (as in @option{-blockdev}), and additionally @option{cache.writeback},
1071 which provides a default for the @option{write-cache} option of block guest
1072 devices (as in @option{-device}). The modes correspond to the following
1075 @c Our texi2pod.pl script doesn't support @multitable, so fall back to using
1076 @c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
1077 @c and the HTML output.
1079 @ │ cache.writeback cache.direct cache.no-flush
1080 ─────────────┼─────────────────────────────────────────────────
1081 writeback │ on off off
1083 writethrough │ off off off
1084 directsync │ off on off
1085 unsafe │ on off on
1088 The default mode is @option{cache=writeback}.
1091 @var{aio} is "threads
", or "native
" and selects between pthread based disk I/O and native Linux AIO.
1092 @item format=@var{format}
1093 Specify which disk @var{format} will be used rather than detecting
1094 the format. Can be used to specify format=raw to avoid interpreting
1095 an untrusted format header.
1096 @item werror=@var{action},rerror=@var{action}
1097 Specify which @var{action} to take on write and read errors. Valid actions are:
1098 "ignore
" (ignore the error and try to continue), "stop
" (pause QEMU),
1099 "report
" (report the error to the guest), "enospc
" (pause QEMU only if the
1100 host disk is full; report the error to the guest otherwise).
1101 The default setting is @option{werror=enospc} and @option{rerror=report}.
1102 @item copy-on-read=@var{copy-on-read}
1103 @var{copy-on-read} is "on
" or "off
" and enables whether to copy read backing
1104 file sectors into the image file.
1105 @item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
1106 Specify bandwidth throttling limits in bytes per second, either for all request
1107 types or for reads or writes only. Small values can lead to timeouts or hangs
1108 inside the guest. A safe minimum for disks is 2 MB/s.
1109 @item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
1110 Specify bursts in bytes per second, either for all request types or for reads
1111 or writes only. Bursts allow the guest I/O to spike above the limit
1113 @item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
1114 Specify request rate limits in requests per second, either for all request
1115 types or for reads or writes only.
1116 @item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
1117 Specify bursts in requests per second, either for all request types or for reads
1118 or writes only. Bursts allow the guest I/O to spike above the limit
1120 @item iops_size=@var{is}
1121 Let every @var{is} bytes of a request count as a new request for iops
1122 throttling purposes. Use this option to prevent guests from circumventing iops
1123 limits by sending fewer but larger requests.
1125 Join a throttling quota group with given name @var{g}. All drives that are
1126 members of the same group are accounted for together. Use this option to
1127 prevent guests from circumventing throttling limits by using many small disks
1128 instead of a single larger disk.
1131 By default, the @option{cache.writeback=on} mode is used. It will report data
1132 writes as completed as soon as the data is present in the host page cache.
1133 This is safe as long as your guest OS makes sure to correctly flush disk caches
1134 where needed. If your guest OS does not handle volatile disk write caches
1135 correctly and your host crashes or loses power, then the guest may experience
1138 For such guests, you should consider using @option{cache.writeback=off}. This
1139 means that the host page cache will be used to read and write data, but write
1140 notification will be sent to the guest only after QEMU has made sure to flush
1141 each write to the disk. Be aware that this has a major impact on performance.
1143 When using the @option{-snapshot} option, unsafe caching is always used.
1145 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
1146 useful when the backing file is over a slow network. By default copy-on-read
1149 Instead of @option{-cdrom} you can use:
1151 qemu-system-i386 -drive file=file,index=2,media=cdrom
1154 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
1157 qemu-system-i386 -drive file=file,index=0,media=disk
1158 qemu-system-i386 -drive file=file,index=1,media=disk
1159 qemu-system-i386 -drive file=file,index=2,media=disk
1160 qemu-system-i386 -drive file=file,index=3,media=disk
1163 You can open an image using pre-opened file descriptors from an fd set:
1166 -add-fd fd=3,set=2,opaque="rdwr
:/path
/to
/file
"
1167 -add-fd fd=4,set=2,opaque="rdonly
:/path
/to
/file
"
1168 -drive file=/dev/fdset/2,index=0,media=disk
1171 You can connect a CDROM to the slave of ide0:
1173 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
1176 If you don't specify the "file
=" argument, you define an empty drive:
1178 qemu-system-i386 -drive if=ide,index=1,media=cdrom
1181 Instead of @option{-fda}, @option{-fdb}, you can use:
1183 qemu-system-i386 -drive file=file,index=0,if=floppy
1184 qemu-system-i386 -drive file=file,index=1,if=floppy
1187 By default, @var{interface} is "ide
" and @var{index} is automatically
1190 qemu-system-i386 -drive file=a -drive file=b"
1192 is interpreted like
:
1194 qemu
-system
-i386
-hda a
-hdb b
1198 DEF("mtdblock", HAS_ARG
, QEMU_OPTION_mtdblock
,
1199 "-mtdblock file use 'file' as on-board Flash memory image\n",
1202 @item
-mtdblock @
var{file
}
1204 Use @
var{file
} as on
-board Flash memory image
.
1207 DEF("sd", HAS_ARG
, QEMU_OPTION_sd
,
1208 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL
)
1210 @item
-sd @
var{file
}
1212 Use @
var{file
} as SecureDigital card image
.
1215 DEF("pflash", HAS_ARG
, QEMU_OPTION_pflash
,
1216 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL
)
1218 @item
-pflash @
var{file
}
1220 Use @
var{file
} as a parallel flash image
.
1223 DEF("snapshot", 0, QEMU_OPTION_snapshot
,
1224 "-snapshot write to temporary files instead of disk image files\n",
1229 Write to temporary files instead of disk image files
. In
this case,
1230 the raw disk image you use is not written back
. You can however force
1231 the write back by pressing @key
{C
-a s
} (@pxref
{disk_images
}).
1234 DEF("fsdev", HAS_ARG
, QEMU_OPTION_fsdev
,
1235 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1236 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1237 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1238 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1239 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1240 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1241 " [[,throttling.iops-size=is]]\n",
1246 @item
-fsdev @
var{fsdriver
},id
=@
var{id
},path
=@
var{path
},[security_model
=@
var{security_model
}][,writeout
=@
var{writeout
}][,readonly
][,socket
=@
var{socket
}|sock_fd
=@
var{sock_fd
}][,fmode
=@
var{fmode
}][,dmode
=@
var{dmode
}]
1248 Define a
new file system device
. Valid options are
:
1250 @item @
var{fsdriver
}
1251 This option specifies the fs driver backend to use
.
1252 Currently
"local" and
"proxy" file system drivers are supported
.
1254 Specifies identifier
for this device
1255 @item path
=@
var{path
}
1256 Specifies the export path
for the file system device
. Files under
1257 this path will be available to the
9p client on the guest
.
1258 @item security_model
=@
var{security_model
}
1259 Specifies the security model to be used
for this export path
.
1260 Supported security models are
"passthrough", "mapped-xattr", "mapped-file" and
"none".
1261 In
"passthrough" security model
, files are stored
using the same
1262 credentials as they are created on the guest
. This requires QEMU
1263 to run as root
. In
"mapped-xattr" security model
, some of the file
1264 attributes like uid
, gid
, mode bits and link target are stored as
1265 file attributes
. For
"mapped-file" these attributes are stored
in the
1266 hidden
.virtfs_metadata directory
. Directories exported by
this security model cannot
1267 interact with other unix tools
. "none" security model is same as
1268 passthrough except the sever won
't report failures if it fails to
1269 set file attributes like ownership. Security model is mandatory
1270 only for local fsdriver. Other fsdrivers (like proxy) don't take
1271 security model as a parameter
.
1272 @item writeout
=@
var{writeout
}
1273 This is an optional argument
. The only supported value is
"immediate".
1274 This means that host page cache will be used to read and write data but
1275 write notification will be sent to the guest only when the data has been
1276 reported as written by the storage subsystem
.
1278 Enables exporting
9p share as a readonly mount
for guests
. By
default
1279 read
-write access is given
.
1280 @item socket
=@
var{socket
}
1281 Enables proxy filesystem driver to use passed socket file
for communicating
1282 with virtfs
-proxy
-helper
1283 @item sock_fd
=@
var{sock_fd
}
1284 Enables proxy filesystem driver to use passed socket descriptor
for
1285 communicating with virtfs
-proxy
-helper
. Usually a helper like libvirt
1286 will create socketpair and pass one of the fds as sock_fd
1287 @item fmode
=@
var{fmode
}
1288 Specifies the
default mode
for newly created files on the host
. Works only
1289 with security models
"mapped-xattr" and
"mapped-file".
1290 @item dmode
=@
var{dmode
}
1291 Specifies the
default mode
for newly created directories on the host
. Works
1292 only with security models
"mapped-xattr" and
"mapped-file".
1295 -fsdev option is used along with
-device driver
"virtio-9p-pci".
1296 @item
-device virtio
-9p
-pci
,fsdev
=@
var{id
},mount_tag
=@
var{mount_tag
}
1297 Options
for virtio
-9p
-pci driver are
:
1299 @item fsdev
=@
var{id
}
1300 Specifies the id value specified along with
-fsdev option
1301 @item mount_tag
=@
var{mount_tag
}
1302 Specifies the tag name to be used by the guest to mount
this export point
1307 DEF("virtfs", HAS_ARG
, QEMU_OPTION_virtfs
,
1308 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1309 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1314 @item
-virtfs @
var{fsdriver
}[,path
=@
var{path
}],mount_tag
=@
var{mount_tag
}[,security_model
=@
var{security_model
}][,writeout
=@
var{writeout
}][,readonly
][,socket
=@
var{socket
}|sock_fd
=@
var{sock_fd
}][,fmode
=@
var{fmode
}][,dmode
=@
var{dmode
}]
1317 The general form of a Virtual File system pass
-through options are
:
1319 @item @
var{fsdriver
}
1320 This option specifies the fs driver backend to use
.
1321 Currently
"local" and
"proxy" file system drivers are supported
.
1323 Specifies identifier
for this device
1324 @item path
=@
var{path
}
1325 Specifies the export path
for the file system device
. Files under
1326 this path will be available to the
9p client on the guest
.
1327 @item security_model
=@
var{security_model
}
1328 Specifies the security model to be used
for this export path
.
1329 Supported security models are
"passthrough", "mapped-xattr", "mapped-file" and
"none".
1330 In
"passthrough" security model
, files are stored
using the same
1331 credentials as they are created on the guest
. This requires QEMU
1332 to run as root
. In
"mapped-xattr" security model
, some of the file
1333 attributes like uid
, gid
, mode bits and link target are stored as
1334 file attributes
. For
"mapped-file" these attributes are stored
in the
1335 hidden
.virtfs_metadata directory
. Directories exported by
this security model cannot
1336 interact with other unix tools
. "none" security model is same as
1337 passthrough except the sever won
't report failures if it fails to
1338 set file attributes like ownership. Security model is mandatory only
1339 for local fsdriver. Other fsdrivers (like proxy) don't take security
1340 model as a parameter
.
1341 @item writeout
=@
var{writeout
}
1342 This is an optional argument
. The only supported value is
"immediate".
1343 This means that host page cache will be used to read and write data but
1344 write notification will be sent to the guest only when the data has been
1345 reported as written by the storage subsystem
.
1347 Enables exporting
9p share as a readonly mount
for guests
. By
default
1348 read
-write access is given
.
1349 @item socket
=@
var{socket
}
1350 Enables proxy filesystem driver to use passed socket file
for
1351 communicating with virtfs
-proxy
-helper
. Usually a helper like libvirt
1352 will create socketpair and pass one of the fds as sock_fd
1354 Enables proxy filesystem driver to use passed
'sock_fd' as the socket
1355 descriptor
for interfacing with virtfs
-proxy
-helper
1356 @item fmode
=@
var{fmode
}
1357 Specifies the
default mode
for newly created files on the host
. Works only
1358 with security models
"mapped-xattr" and
"mapped-file".
1359 @item dmode
=@
var{dmode
}
1360 Specifies the
default mode
for newly created directories on the host
. Works
1361 only with security models
"mapped-xattr" and
"mapped-file".
1365 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth
,
1366 "-virtfs_synth Create synthetic file system image\n",
1370 @findex
-virtfs_synth
1371 Create synthetic file system image
. Note that
this option is now deprecated
.
1372 Please use @code
{-fsdev synth
} and @code
{-device virtio
-9p
-...} instead
.
1375 DEF("iscsi", HAS_ARG
, QEMU_OPTION_iscsi
,
1376 "-iscsi [user=user][,password=password]\n"
1377 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1378 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1379 " [,timeout=timeout]\n"
1380 " iSCSI session parameters\n", QEMU_ARCH_ALL
)
1385 Configure iSCSI session parameters
.
1393 DEFHEADING(USB options
:)
1398 DEF("usb", 0, QEMU_OPTION_usb
,
1399 "-usb enable the USB driver (if it is not used by default yet)\n",
1404 Enable the USB
driver (if it is not used by
default yet
).
1407 DEF("usbdevice", HAS_ARG
, QEMU_OPTION_usbdevice
,
1408 "-usbdevice name add the host or guest USB device 'name'\n",
1412 @item
-usbdevice @
var{devname
}
1414 Add the USB device @
var{devname
}. Note that
this option is deprecated
,
1415 please use @code
{-device usb
-...} instead
. @xref
{usb_devices
}.
1420 Virtual Mouse
. This will
override the PS
/2 mouse emulation when activated
.
1423 Pointer device that uses absolute
coordinates (like a touchscreen
). This
1424 means QEMU is able to report the mouse position without having to grab the
1425 mouse
. Also overrides the PS
/2 mouse emulation when activated
.
1428 Braille device
. This will use BrlAPI to display the braille output on a real
1439 DEFHEADING(Display options
:)
1444 DEF("display", HAS_ARG
, QEMU_OPTION_display
,
1445 "-display spice-app[,gl=on|off]\n"
1446 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1447 " [,window_close=on|off][,gl=on|core|es|off]\n"
1448 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1449 "-display vnc=<display>[,<optargs>]\n"
1450 "-display curses[,charset=<encoding>]\n"
1452 "-display egl-headless[,rendernode=<file>]"
1453 " select display type\n"
1454 "The default display is equivalent to\n"
1455 #
if defined(CONFIG_GTK
)
1456 "\t\"-display gtk\"\n"
1457 #elif
defined(CONFIG_SDL
)
1458 "\t\"-display sdl\"\n"
1459 #elif
defined(CONFIG_COCOA
)
1460 "\t\"-display cocoa\"\n"
1461 #elif
defined(CONFIG_VNC
)
1462 "\t\"-vnc localhost:0,to=99,id=default\"\n"
1464 "\t\"-display none\"\n"
1468 @item
-display @
var{type
}
1470 Select type of display to use
. This option is a replacement
for the
1471 old style
-sdl
/-curses
/... options
. Valid values
for @
var{type
} are
1474 Display video output via
SDL (usually
in a separate graphics
1475 window
; see the SDL documentation
for other possibilities
).
1477 Display video output via curses
. For graphics device models which
1478 support a text mode
, QEMU can display
this output
using a
1479 curses
/ncurses
interface. Nothing is displayed when the graphics
1480 device is
in graphical mode or
if the graphics device does not support
1481 a text mode
. Generally only the VGA device models support text mode
.
1482 The font charset used by the guest can be specified with the
1483 @code
{charset
} option
, for example @code
{charset
=CP850
} for IBM CP850
1484 encoding
. The
default is @code
{CP437
}.
1486 Do not display video output
. The guest will still see an emulated
1487 graphics card
, but its output will not be displayed to the QEMU
1488 user
. This option differs from the
-nographic option
in that it
1489 only affects what is done with video output
; -nographic also changes
1490 the destination of the serial and parallel port data
.
1492 Display video output
in a GTK window
. This
interface provides drop
-down
1493 menus and other UI elements to configure and control the VM during
1496 Start a VNC server on display
<arg
>
1498 Offload all OpenGL operations to a local DRI device
. For any graphical display
,
1499 this display needs to be paired with either VNC or SPICE displays
.
1501 Start QEMU as a Spice server and launch the
default Spice client
1502 application
. The Spice server will redirect the serial consoles and
1503 QEMU monitors
. (Since
4.0)
1507 DEF("nographic", 0, QEMU_OPTION_nographic
,
1508 "-nographic disable graphical output and redirect serial I/Os to console\n",
1513 Normally
, if QEMU is compiled with graphical window support
, it displays
1514 output such as guest graphics
, guest console
, and the QEMU monitor
in a
1515 window
. With
this option
, you can totally disable graphical output so
1516 that QEMU is a simple command line application
. The emulated serial port
1517 is redirected on the console and muxed with the
monitor (unless
1518 redirected elsewhere explicitly
). Therefore
, you can still use QEMU to
1519 debug a Linux kernel with a serial console
. Use @key
{C
-a h
} for help on
1520 switching between the console and monitor
.
1523 DEF("curses", 0, QEMU_OPTION_curses
,
1524 "-curses shorthand for -display curses\n",
1529 Normally
, if QEMU is compiled with graphical window support
, it displays
1530 output such as guest graphics
, guest console
, and the QEMU monitor
in a
1531 window
. With
this option
, QEMU can display the VGA output when
in text
1532 mode
using a curses
/ncurses
interface. Nothing is displayed
in graphical
1536 DEF("alt-grab", 0, QEMU_OPTION_alt_grab
,
1537 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1542 Use Ctrl
-Alt
-Shift to grab
mouse (instead of Ctrl
-Alt
). Note that
this also
1543 affects the special
keys (for fullscreen
, monitor
-mode switching
, etc
).
1546 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab
,
1547 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1552 Use Right
-Ctrl to grab
mouse (instead of Ctrl
-Alt
). Note that
this also
1553 affects the special
keys (for fullscreen
, monitor
-mode switching
, etc
).
1556 DEF("no-quit", 0, QEMU_OPTION_no_quit
,
1557 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL
)
1561 Disable SDL window close capability
.
1564 DEF("sdl", 0, QEMU_OPTION_sdl
,
1565 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL
)
1572 DEF("spice", HAS_ARG
, QEMU_OPTION_spice
,
1573 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1574 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1575 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1576 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1577 " [,tls-ciphers=<list>]\n"
1578 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1579 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1580 " [,sasl][,password=<secret>][,disable-ticketing]\n"
1581 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1582 " [,jpeg-wan-compression=[auto|never|always]]\n"
1583 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
1584 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1585 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1586 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1587 " [,gl=[on|off]][,rendernode=<file>]\n"
1589 " at least one of {port, tls-port} is mandatory\n",
1592 @item
-spice @
var{option
}[,@
var{option
}[,...]]
1594 Enable the spice remote desktop protocol
. Valid options are
1599 Set the TCP port spice is listening on
for plaintext channels
.
1602 Set the IP address spice is listening on
. Default is any address
.
1607 Force
using the specified IP version
.
1609 @item password
=<secret
>
1610 Set the password you need to authenticate
.
1613 Require that the client use SASL to authenticate with the spice
.
1614 The exact choice of authentication method used is controlled from the
1615 system
/ user
's SASL configuration file for the 'qemu
' service. This
1616 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1617 unprivileged user, an environment variable SASL_CONF_PATH can be used
1618 to make it search alternate locations for the service config.
1619 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1620 it is recommended that SASL always be combined with the 'tls
' and
1621 'x509
' settings to enable use of SSL and server certificates. This
1622 ensures a data encryption preventing compromise of authentication
1625 @item disable-ticketing
1626 Allow client connects without authentication.
1628 @item disable-copy-paste
1629 Disable copy paste between the client and the guest.
1631 @item disable-agent-file-xfer
1632 Disable spice-vdagent based file-xfer between the client and the guest.
1635 Set the TCP port spice is listening on for encrypted channels.
1637 @item x509-dir=<dir>
1638 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1640 @item x509-key-file=<file>
1641 @itemx x509-key-password=<file>
1642 @itemx x509-cert-file=<file>
1643 @itemx x509-cacert-file=<file>
1644 @itemx x509-dh-key-file=<file>
1645 The x509 file names can also be configured individually.
1647 @item tls-ciphers=<list>
1648 Specify which ciphers to use.
1650 @item tls-channel=[main|display|cursor|inputs|record|playback]
1651 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1652 Force specific channel to be used with or without TLS encryption. The
1653 options can be specified multiple times to configure multiple
1654 channels. The special name "default" can be used to set the default
1655 mode. For channels which are not explicitly forced into one mode the
1656 spice client is allowed to pick tls/plaintext as he pleases.
1658 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1659 Configure image compression (lossless).
1660 Default is auto_glz.
1662 @item jpeg-wan-compression=[auto|never|always]
1663 @itemx zlib-glz-wan-compression=[auto|never|always]
1664 Configure wan image compression (lossy for slow links).
1667 @item streaming-video=[off|all|filter]
1668 Configure video stream detection. Default is off.
1670 @item agent-mouse=[on|off]
1671 Enable/disable passing mouse events via vdagent. Default is on.
1673 @item playback-compression=[on|off]
1674 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1676 @item seamless-migration=[on|off]
1677 Enable/disable spice seamless migration. Default is off.
1680 Enable/disable OpenGL context. Default is off.
1682 @item rendernode=<file>
1683 DRM render node for OpenGL rendering. If not specified, it will pick
1684 the first available. (Since 2.9)
1689 DEF("portrait", 0, QEMU_OPTION_portrait,
1690 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1695 Rotate graphical output 90 deg left (only PXA LCD).
1698 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1699 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1702 @item -rotate @var{deg}
1704 Rotate graphical output some deg left (only PXA LCD).
1707 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1708 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1709 " select video card type\n", QEMU_ARCH_ALL)
1711 @item -vga @var{type}
1713 Select type of VGA card to emulate. Valid values for @var{type} are
1716 Cirrus Logic GD5446 Video card. All Windows versions starting from
1717 Windows 95 should recognize and use this graphic card. For optimal
1718 performances, use 16 bit color depth in the guest and the host OS.
1719 (This card was the default before QEMU 2.2)
1721 Standard VGA card with Bochs VBE extensions. If your guest OS
1722 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1723 to use high resolution modes (>= 1280x1024x16) then you should use
1724 this option. (This card is the default since QEMU 2.2)
1726 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1727 recent XFree86/XOrg server or Windows guest with a driver for this
1730 QXL paravirtual graphic card. It is VGA compatible (including VESA
1731 2.0 VBE support). Works best with qxl guest drivers installed though.
1732 Recommended choice when using the spice protocol.
1734 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1735 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1736 fixed resolution of 1024x768.
1738 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1739 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1740 resolutions aimed at people wishing to run older Solaris versions.
1748 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1749 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1752 @findex -full-screen
1753 Start in full screen.
1756 DEF("g", 1, QEMU_OPTION_g ,
1757 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1758 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1760 @item -g @var{width}x@var{height}[x@var{depth}]
1762 Set the initial graphical resolution and depth (PPC, SPARC only).
1765 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1766 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1768 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1770 Normally, if QEMU is compiled with graphical window support, it displays
1771 output such as guest graphics, guest console, and the QEMU monitor in a
1772 window. With this option, you can have QEMU listen on VNC display
1773 @var{display} and redirect the VGA display over the VNC session. It is
1774 very useful to enable the usb tablet device when using this option
1775 (option @option{-device usb-tablet}). When using the VNC display, you
1776 must use the @option{-k} parameter to set the keyboard layout if you are
1777 not using en-us. Valid syntax for the @var{display} is
1783 With this option, QEMU will try next available VNC @var{display}s, until the
1784 number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1785 available, e.g. port 5900+@var{display} is already used by another
1786 application. By default, to=0.
1788 @item @var{host}:@var{d}
1790 TCP connections will only be allowed from @var{host} on display @var{d}.
1791 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1792 be omitted in which case the server will accept connections from any host.
1794 @item unix:@var{path}
1796 Connections will be allowed over UNIX domain sockets where @var{path} is the
1797 location of a unix socket to listen for connections on.
1801 VNC is initialized but not started. The monitor @code{change} command
1802 can be used to later start the VNC server.
1806 Following the @var{display} value there may be one or more @var{option} flags
1807 separated by commas. Valid options are
1813 Connect to a listening VNC client via a ``reverse'' connection. The
1814 client is specified by the @var{display}. For reverse network
1815 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1816 is a TCP port number, not a display number.
1820 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1821 If a bare @var{websocket} option is given, the Websocket port is
1822 5700+@var{display}. An alternative port can be specified with the
1823 syntax @code{websocket}=@var{port}.
1825 If @var{host} is specified connections will only be allowed from this host.
1826 It is possible to control the websocket listen address independently, using
1827 the syntax @code{websocket}=@var{host}:@var{port}.
1829 If no TLS credentials are provided, the websocket connection runs in
1830 unencrypted mode. If TLS credentials are provided, the websocket connection
1831 requires encrypted client connections.
1835 Require that password based authentication is used for client connections.
1837 The password must be set separately using the @code{set_password} command in
1838 the @ref{pcsys_monitor}. The syntax to change your password is:
1839 @code{set_password <protocol> <password>} where <protocol> could be either
1842 If you would like to change <protocol> password expiration, you should use
1843 @code{expire_password <protocol> <expiration-time>} where expiration time could
1844 be one of the following options: now, never, +seconds or UNIX time of
1845 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1846 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1849 You can also use keywords "now" or "never" for the expiration time to
1850 allow <protocol> password to expire immediately or never expire.
1852 @item tls-creds=@var{ID}
1854 Provides the ID of a set of TLS credentials to use to secure the
1855 VNC server. They will apply to both the normal VNC server socket
1856 and the websocket socket (if enabled). Setting TLS credentials
1857 will cause the VNC server socket to enable the VeNCrypt auth
1858 mechanism. The credentials should have been previously created
1859 using the @option{-object tls-creds} argument.
1861 @item tls-authz=@var{ID}
1863 Provides the ID of the QAuthZ authorization object against which
1864 the client's x509 distinguished name will validated
. This object is
1865 only resolved at time of use
, so can be deleted and recreated on the
1866 fly
while the VNC server is active
. If missing
, it will
default
1871 Require that the client use SASL to authenticate with the VNC server
.
1872 The exact choice of authentication method used is controlled from the
1873 system
/ user
's SASL configuration file for the 'qemu
' service. This
1874 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1875 unprivileged user, an environment variable SASL_CONF_PATH can be used
1876 to make it search alternate locations for the service config.
1877 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1878 it is recommended that SASL always be combined with the 'tls
' and
1879 'x509
' settings to enable use of SSL and server certificates. This
1880 ensures a data encryption preventing compromise of authentication
1881 credentials. See the @ref{vnc_security} section for details on using
1882 SASL authentication.
1884 @item sasl-authz=@var{ID}
1886 Provides the ID of the QAuthZ authorization object against which
1887 the client's SASL username will validated
. This object is
1888 only resolved at time of use
, so can be deleted and recreated on the
1889 fly
while the VNC server is active
. If missing
, it will
default
1894 Legacy method
for enabling authorization of clients against the
1895 x509 distinguished name and SASL username
. It results
in the creation
1896 of two @code
{authz
-list
} objects with IDs of @code
{vnc
.username
} and
1897 @code
{vnc
.x509dname
}. The rules
for these objects must be configured
1898 with the HMP ACL commands
.
1900 This option is deprecated and should no longer be used
. The
new
1901 @option
{sasl
-authz
} and @option
{tls
-authz
} options are a
1906 Enable lossy compression
methods (gradient
, JPEG
, ...). If
this
1907 option is set
, VNC client may receive lossy framebuffer updates
1908 depending on its encoding settings
. Enabling
this option can save
1909 a lot of bandwidth at the expense of quality
.
1913 Disable adaptive encodings
. Adaptive encodings are enabled by
default.
1914 An adaptive encoding will
try to detect frequently updated screen regions
,
1915 and send updates
in these regions
using a lossy
encoding (like JPEG
).
1916 This can be really helpful to save bandwidth when playing videos
. Disabling
1917 adaptive encodings restores the original
static behavior of encodings
1920 @item share
=[allow
-exclusive|force
-shared|ignore
]
1922 Set display sharing policy
. 'allow-exclusive' allows clients to ask
1923 for exclusive access
. As suggested by the rfb spec
this is
1924 implemented by dropping other connections
. Connecting multiple
1925 clients
in parallel requires all clients asking
for a shared session
1926 (vncviewer
: -shared
switch). This is the
default. 'force-shared'
1927 disables exclusive client access
. Useful
for shared desktop sessions
,
1928 where you don
't want someone forgetting specify -shared disconnect
1929 everybody else. 'ignore
' completely ignores the shared flag and
1930 allows everybody connect unconditionally. Doesn't conform to the rfb
1931 spec but is traditional QEMU behavior
.
1935 Set keyboard delay
, for key down and key up events
, in milliseconds
.
1936 Default is
10. Keyboards are low
-bandwidth devices
, so
this slowdown
1937 can help the device and guest to keep up and not lose events
in case
1938 events are arriving
in bulk
. Possible causes
for the latter are flaky
1939 network connections
, or scripts
for automated testing
.
1947 ARCHHEADING(, QEMU_ARCH_I386
)
1949 ARCHHEADING(i386 target only
:, QEMU_ARCH_I386
)
1954 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack
,
1955 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1960 Use it when installing Windows
2000 to avoid a disk full bug
. After
1961 Windows
2000 is installed
, you no longer need
this option (this option
1962 slows down the IDE transfers
).
1965 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk
,
1966 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1969 @item
-no
-fd
-bootchk
1970 @findex
-no
-fd
-bootchk
1971 Disable boot signature checking
for floppy disks
in BIOS
. May
1972 be needed to boot from old floppy disks
.
1975 DEF("no-acpi", 0, QEMU_OPTION_no_acpi
,
1976 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM
)
1980 Disable
ACPI (Advanced Configuration and Power Interface
) support
. Use
1981 it
if your guest OS complains about ACPI
problems (PC target machine
1985 DEF("no-hpet", 0, QEMU_OPTION_no_hpet
,
1986 "-no-hpet disable HPET\n", QEMU_ARCH_I386
)
1990 Disable HPET support
.
1993 DEF("acpitable", HAS_ARG
, QEMU_OPTION_acpitable
,
1994 "-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"
1995 " ACPI table description\n", QEMU_ARCH_I386
)
1997 @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
}]...]
1999 Add ACPI table with specified header fields and context from specified files
.
2000 For file
=, take whole ACPI table from the specified files
, including all
2001 ACPI
headers (possible overridden by other options
).
2002 For data
=, only data
2003 portion of the table is used
, all header information is specified
in the
2005 If a SLIC table is supplied to QEMU
, then the SLIC
's oem_id and oem_table_id
2006 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
2007 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
2011 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
2012 "-smbios file=binary\n"
2013 " load SMBIOS entry from binary file\n"
2014 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
2016 " specify SMBIOS type 0 fields\n"
2017 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2018 " [,uuid=uuid][,sku=str][,family=str]\n"
2019 " specify SMBIOS type 1 fields\n"
2020 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2021 " [,asset=str][,location=str]\n"
2022 " specify SMBIOS type 2 fields\n"
2023 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
2025 " specify SMBIOS type 3 fields\n"
2026 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
2027 " [,asset=str][,part=str]\n"
2028 " specify SMBIOS type 4 fields\n"
2029 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
2030 " [,asset=str][,part=str][,speed=%d]\n"
2031 " specify SMBIOS type 17 fields\n",
2032 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
2034 @item -smbios file=@var{binary}
2036 Load SMBIOS entry from binary file.
2038 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
2039 Specify SMBIOS type 0 fields
2041 @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}]
2042 Specify SMBIOS type 1 fields
2044 @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}]
2045 Specify SMBIOS type 2 fields
2047 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
2048 Specify SMBIOS type 3 fields
2050 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
2051 Specify SMBIOS type 4 fields
2053 @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}]
2054 Specify SMBIOS type 17 fields
2062 DEFHEADING(Network options:)
2067 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
2069 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
2070 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
2071 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
2072 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
2073 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
2075 "[,smb=dir[,smbserver=addr]]\n"
2077 " configure a user mode network backend with ID 'str
',\n"
2078 " its DHCP server and optional services\n"
2081 "-netdev tap,id=str,ifname=name\n"
2082 " configure a host TAP network backend with ID 'str
'\n"
2084 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
2085 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
2086 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
2088 " configure a host TAP network backend with ID 'str
'\n"
2089 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
2090 " use network scripts 'file
' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
2091 " to configure it and 'dfile
' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
2092 " to deconfigure it\n"
2093 " use '[down
]script
=no
' to disable script execution\n"
2094 " use network helper 'helper
' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
2096 " use 'fd
=h
' to connect to an already opened TAP interface\n"
2097 " use 'fds
=x
:y
:...:z
' to connect to already opened multiqueue capable TAP interfaces\n"
2098 " use 'sndbuf
=nbytes
' to limit the size of the send buffer (the\n"
2099 " default is disabled 'sndbuf
=0' to enable flow control set 'sndbuf
=1048576')\n"
2100 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
2101 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
2102 " use vhost=on to enable experimental in kernel accelerator\n"
2103 " (only has effect for virtio guests which use MSIX)\n"
2104 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
2105 " use 'vhostfd
=h
' to connect to an already opened vhost net device\n"
2106 " use 'vhostfds
=x
:y
:...:z to connect to multiple already opened vhost net devices
\n"
2107 " use
'queues=n' to specify the number of queues to be created
for multiqueue TAP
\n"
2108 " use
'poll-us=n' to speciy the maximum number of microseconds that could be
\n"
2109 " spent on busy polling
for vhost net
\n"
2110 "-netdev bridge
,id
=str
[,br
=bridge
][,helper
=helper
]\n"
2111 " configure a host TAP network backend with ID
'str' that is
\n"
2112 " connected to a
bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
2113 " using the program
'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
2116 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
2117 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
2118 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
2119 " [,rxcookie=rxcookie][,offset=offset]\n"
2120 " configure a network backend with ID 'str
' connected to\n"
2121 " an Ethernet over L2TPv3 pseudowire.\n"
2122 " Linux kernel 3.3+ as well as most routers can talk\n"
2123 " L2TPv3. This transport allows connecting a VM to a VM,\n"
2124 " VM to a router and even VM to Host. It is a nearly-universal\n"
2125 " standard (RFC3391). Note - this implementation uses static\n"
2126 " pre-configured tunnels (same as the Linux kernel).\n"
2127 " use 'src
=' to specify source address\n"
2128 " use 'dst
=' to specify destination address\n"
2129 " use 'udp
=on
' to specify udp encapsulation\n"
2130 " use 'srcport
=' to specify source udp port\n"
2131 " use 'dstport
=' to specify destination udp port\n"
2132 " use 'ipv6
=on
' to force v6\n"
2133 " L2TPv3 uses cookies to prevent misconfiguration as\n"
2134 " well as a weak security measure\n"
2135 " use 'rxcookie
=0x012345678' to specify a rxcookie\n"
2136 " use 'txcookie
=0x012345678' to specify a txcookie\n"
2137 " use 'cookie64
=on
' to set cookie size to 64 bit, otherwise 32\n"
2138 " use 'counter
=off
' to force a 'cut
-down
' L2TPv3 with no counter\n"
2139 " use 'pincounter
=on
' to work around broken counter handling in peer\n"
2140 " use 'offset
=X
' to add an extra offset between header and data\n"
2142 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
2143 " configure a network backend to connect to another network\n"
2144 " using a socket connection\n"
2145 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
2146 " configure a network backend to connect to a multicast maddr and port\n"
2147 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
2148 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
2149 " configure a network backend to connect to another network\n"
2150 " using an UDP tunnel\n"
2152 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
2153 " configure a network backend to connect to port 'n
' of a vde switch\n"
2154 " running on host and listening for incoming connections on 'socketpath
'.\n"
2155 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
2156 " ownership and permissions for communication port.\n"
2158 #ifdef CONFIG_NETMAP
2159 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
2160 " attach to the existing netmap-enabled network interface 'name
', or to a\n"
2161 " VALE port (created on the fly) called 'name
' ('nmname
' is name of the \n"
2162 " netmap device, defaults to '/dev
/netmap
')\n"
2165 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2166 " configure a vhost-user network, backed by a chardev 'dev
'\n"
2168 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
2169 " configure a hub port on the hub with ID 'n
'\n", QEMU_ARCH_ALL)
2170 DEF("nic", HAS_ARG, QEMU_OPTION_nic,
2181 #ifdef CONFIG_NETMAP
2187 "socket][,option][,...][mac=macaddr]\n"
2188 " initialize an on-board / default host NIC (using MAC address\n"
2189 " macaddr) and connect it to the given host network backend\n"
2190 "-nic none use it alone to have zero network devices (the default is to\n"
2191 " provided a 'user
' network connection)\n",
2193 DEF("net", HAS_ARG, QEMU_OPTION_net,
2194 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
2195 " configure or create an on-board (or machine default) NIC and\n"
2196 " connect it to hub 0 (please use -nic unless you need a hub)\n"
2206 #ifdef CONFIG_NETMAP
2209 "socket][,option][,option][,...]\n"
2210 " old way to initialize a host network interface\n"
2211 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2213 @item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]
2215 This option is a shortcut for configuring both the on-board (default) guest
2216 NIC hardware and the host network backend in one go. The host backend options
2217 are the same as with the corresponding @option{-netdev} options below.
2218 The guest NIC model can be set with @option{model=@var{modelname}}.
2219 Use @option{model=help} to list the available device types.
2220 The hardware MAC address can be set with @option{mac=@var{macaddr}}.
2222 The following two example do exactly the same, to show how @option{-nic} can
2223 be used to shorten the command line length (note that the e1000 is the default
2224 on i386, so the @option{model=e1000} parameter could even be omitted here, too):
2226 qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
2227 qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2231 Indicate that no network devices should be configured. It is used to override
2232 the default configuration (default NIC with ``user'' host network backend)
2233 which is activated if no other networking options are provided.
2235 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2237 Configure user mode host network backend which requires no administrator
2238 privilege to run. Valid options are:
2242 Assign symbolic name for use in monitor commands.
2244 @item ipv4=on|off and ipv6=on|off
2245 Specify that either IPv4 or IPv6 must be enabled. If neither is specified
2246 both protocols are enabled.
2248 @item net=@var{addr}[/@var{mask}]
2249 Set IP network address the guest will see. Optionally specify the netmask,
2250 either in the form a.b.c.d or as number of valid top-most bits. Default is
2253 @item host=@var{addr}
2254 Specify the guest-visible address of the host. Default is the 2nd IP in the
2255 guest network, i.e. x.x.x.2.
2257 @item ipv6-net=@var{addr}[/@var{int}]
2258 Set IPv6 network address the guest will see (default is fec0::/64). The
2259 network prefix is given in the usual hexadecimal IPv6 address
2260 notation. The prefix size is optional, and is given as the number of
2261 valid top-most bits (default is 64).
2263 @item ipv6-host=@var{addr}
2264 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2265 the guest network, i.e. xxxx::2.
2267 @item restrict=on|off
2268 If this option is enabled, the guest will be isolated, i.e. it will not be
2269 able to contact the host and no guest IP packets will be routed over the host
2270 to the outside. This option does not affect any explicitly set forwarding rules.
2272 @item hostname=@var{name}
2273 Specifies the client hostname reported by the built-in DHCP server.
2275 @item dhcpstart=@var{addr}
2276 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2277 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2279 @item dns=@var{addr}
2280 Specify the guest-visible address of the virtual nameserver. The address must
2281 be different from the host address. Default is the 3rd IP in the guest network,
2284 @item ipv6-dns=@var{addr}
2285 Specify the guest-visible address of the IPv6 virtual nameserver. The address
2286 must be different from the host address. Default is the 3rd IP in the guest
2287 network, i.e. xxxx::3.
2289 @item dnssearch=@var{domain}
2290 Provides an entry for the domain-search list sent by the built-in
2291 DHCP server. More than one domain suffix can be transmitted by specifying
2292 this option multiple times. If supported, this will cause the guest to
2293 automatically try to append the given domain suffix(es) in case a domain name
2294 can not be resolved.
2298 qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2301 @item domainname=@var{domain}
2302 Specifies the client domain name reported by the built-in DHCP server.
2304 @item tftp=@var{dir}
2305 When using the user mode network stack, activate a built-in TFTP
2306 server. The files in @var{dir} will be exposed as the root of a TFTP server.
2307 The TFTP client on the guest must be configured in binary mode (use the command
2308 @code{bin} of the Unix TFTP client).
2310 @item tftp-server-name=@var{name}
2311 In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option
2312 66). This can be used to advise the guest to load boot files or configurations
2313 from a different server than the host address.
2315 @item bootfile=@var{file}
2316 When using the user mode network stack, broadcast @var{file} as the BOOTP
2317 filename. In conjunction with @option{tftp}, this can be used to network boot
2318 a guest from a local directory.
2320 Example (using pxelinux):
2322 qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2323 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2326 @item smb=@var{dir}[,smbserver=@var{addr}]
2327 When using the user mode network stack, activate a built-in SMB
2328 server so that Windows OSes can access to the host files in @file{@var{dir}}
2329 transparently. The IP address of the SMB server can be set to @var{addr}. By
2330 default the 4th IP in the guest network is used, i.e. x.x.x.4.
2332 In the guest Windows OS, the line:
2336 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2337 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2339 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2341 Note that a SAMBA server must be installed on the host OS.
2343 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2344 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2345 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2346 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2347 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2348 be bound to a specific host interface. If no connection type is set, TCP is
2349 used. This option can be given multiple times.
2351 For example, to redirect host X11 connection from screen 1 to guest
2352 screen 0, use the following:
2356 qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2357 # this host xterm should open in the guest X11 server
2361 To redirect telnet connections from host port 5555 to telnet port on
2362 the guest, use the following:
2366 qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2367 telnet localhost 5555
2370 Then when you use on the host @code{telnet localhost 5555}, you
2371 connect to the guest telnet server.
2373 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2374 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2375 Forward guest TCP connections to the IP address @var{server} on port @var{port}
2376 to the character device @var{dev} or to a program executed by @var{cmd:command}
2377 which gets spawned for each connection. This option can be given multiple times.
2379 You can either use a chardev directly and have that one used throughout QEMU's
2380 lifetime
, like
in the following example
:
2383 # open
10.10.1.1:4321 on bootup
, connect
10.0.2.100:1234 to it whenever
2384 # the guest accesses it
2385 qemu
-system
-i386
-nic user
,guestfwd
=tcp
:10.0.2.100:1234-tcp
:10.10.1.1:4321
2388 Or you can execute a command on every TCP connection established by the guest
,
2389 so that QEMU behaves similar to an inetd process
for that virtual server
:
2392 # call
"netcat 10.10.1.1 4321" on every TCP connection to
10.0.2.100:1234
2393 # and connect the TCP stream to its stdin
/stdout
2394 qemu
-system
-i386
-nic
'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2399 @item
-netdev tap
,id
=@
var{id
}[,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
2400 Configure a host TAP network backend with ID @
var{id
}.
2402 Use the network script @
var{file
} to configure it and the network script
2403 @
var{dfile
} to deconfigure it
. If @
var{name
} is not provided
, the OS
2404 automatically provides one
. The
default network configure script is
2405 @file
{/etc
/qemu
-ifup
} and the
default network deconfigure script is
2406 @file
{/etc
/qemu
-ifdown
}. Use @option
{script
=no
} or @option
{downscript
=no
}
2407 to disable script execution
.
2409 If running QEMU as an unprivileged user
, use the network helper
2410 @
var{helper
} to configure the TAP
interface and attach it to the bridge
.
2411 The
default network helper executable is @file
{/path
/to
/qemu
-bridge
-helper
}
2412 and the
default bridge device is @file
{br0
}.
2414 @option
{fd
}=@
var{h
} can be used to specify the handle of an already
2415 opened host TAP
interface.
2420 #launch a QEMU instance with the
default network script
2421 qemu
-system
-i386 linux
.img
-nic tap
2425 #launch a QEMU instance with two NICs
, each one connected
2427 qemu
-system
-i386 linux
.img \
2428 -netdev tap
,id
=nd0
,ifname
=tap0
-device e1000
,netdev
=nd0 \
2429 -netdev tap
,id
=nd1
,ifname
=tap1
-device rtl8139
,netdev
=nd1
2433 #launch a QEMU instance with the
default network helper to
2434 #connect a TAP device to bridge br0
2435 qemu
-system
-i386 linux
.img
-device virtio
-net
-pci
,netdev
=n1 \
2436 -netdev tap
,id
=n1
,"helper=/path/to/qemu-bridge-helper"
2439 @item
-netdev bridge
,id
=@
var{id
}[,br
=@
var{bridge
}][,helper
=@
var{helper
}]
2440 Connect a host TAP network
interface to a host bridge device
.
2442 Use the network helper @
var{helper
} to configure the TAP
interface and
2443 attach it to the bridge
. The
default network helper executable is
2444 @file
{/path
/to
/qemu
-bridge
-helper
} and the
default bridge
2445 device is @file
{br0
}.
2450 #launch a QEMU instance with the
default network helper to
2451 #connect a TAP device to bridge br0
2452 qemu
-system
-i386 linux
.img
-netdev bridge
,id
=n1
-device virtio
-net
,netdev
=n1
2456 #launch a QEMU instance with the
default network helper to
2457 #connect a TAP device to bridge qemubr0
2458 qemu
-system
-i386 linux
.img
-netdev bridge
,br
=qemubr0
,id
=n1
-device virtio
-net
,netdev
=n1
2461 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
2463 This host network backend can be used to connect the guest
's network to
2464 another QEMU virtual machine using a TCP socket connection. If @option{listen}
2465 is specified, QEMU waits for incoming connections on @var{port}
2466 (@var{host} is optional). @option{connect} is used to connect to
2467 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2468 specifies an already opened TCP socket.
2472 # launch a first QEMU instance
2473 qemu-system-i386 linux.img \
2474 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2475 -netdev socket,id=n1,listen=:1234
2476 # connect the network of this instance to the network of the first instance
2477 qemu-system-i386 linux.img \
2478 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2479 -netdev socket,id=n2,connect=127.0.0.1:1234
2482 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2484 Configure a socket host network backend to share the guest's network traffic
2485 with another QEMU virtual machines
using a UDP multicast socket
, effectively
2486 making a bus
for every QEMU with same multicast address @
var{maddr
} and @
var{port
}.
2490 Several QEMU can be running on different hosts and share same
bus (assuming
2491 correct multicast setup
for these hosts
).
2493 mcast support is compatible with User Mode
Linux (argument @option
{eth@
var{N
}=mcast
}), see
2494 @url
{http
://user-mode-linux.sf.net}.
2496 Use @option
{fd
=h
} to specify an already opened UDP multicast socket
.
2501 # launch one QEMU instance
2502 qemu
-system
-i386 linux
.img \
2503 -device e1000
,netdev
=n1
,mac
=52:54:00:12:34:56 \
2504 -netdev socket
,id
=n1
,mcast
=230.0.0.1:1234
2505 # launch another QEMU instance on same
"bus"
2506 qemu
-system
-i386 linux
.img \
2507 -device e1000
,netdev
=n2
,mac
=52:54:00:12:34:57 \
2508 -netdev socket
,id
=n2
,mcast
=230.0.0.1:1234
2509 # launch yet another QEMU instance on same
"bus"
2510 qemu
-system
-i386 linux
.img \
2511 -device e1000
,netdev
=n3
,mac
=52:54:00:12:34:58 \
2512 -netdev socket
,id
=n3
,mcast
=230.0.0.1:1234
2515 Example (User Mode Linux compat
.):
2517 # launch QEMU
instance (note mcast address selected is UML
's default)
2518 qemu-system-i386 linux.img \
2519 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2520 -netdev socket,id=n1,mcast=239.192.168.1:1102
2522 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2525 Example (send packets from host's
1.2.3.4):
2527 qemu
-system
-i386 linux
.img \
2528 -device e1000
,netdev
=n1
,mac
=52:54:00:12:34:56 \
2529 -netdev socket
,id
=n1
,mcast
=239.192.168.1:1102,localaddr
=1.2.3.4
2532 @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
}]
2533 Configure a L2TPv3 pseudowire host network backend
. L2TPv3 (RFC3391
) is a
2534 popular protocol to transport
Ethernet (and other Layer
2) data frames between
2535 two systems
. It is present
in routers
, firewalls and the Linux kernel
2536 (from version
3.3 onwards
).
2538 This transport allows a VM to communicate to another VM
, router or firewall directly
.
2541 @item src
=@
var{srcaddr
}
2542 source
address (mandatory
)
2543 @item dst
=@
var{dstaddr
}
2544 destination
address (mandatory
)
2546 select udp
encapsulation (default is ip
).
2547 @item srcport
=@
var{srcport
}
2549 @item dstport
=@
var{dstport
}
2550 destination udp port
.
2552 force v6
, otherwise defaults to v4
.
2553 @item rxcookie
=@
var{rxcookie
}
2554 @itemx txcookie
=@
var{txcookie
}
2555 Cookies are a weak form of security
in the l2tpv3 specification
.
2556 Their
function is mostly to prevent misconfiguration
. By
default they are
32
2559 Set cookie size to
64 bit instead of the
default 32
2561 Force a
'cut-down' L2TPv3 with no counter as
in
2562 draft
-mkonstan
-l2tpext
-keyed
-ipv6
-tunnel
-00
2564 Work around broken counter handling
in peer
. This may also help on
2565 networks which have packet reorder
.
2566 @item offset
=@
var{offset
}
2567 Add an extra offset between header and data
2570 For example
, to attach a VM running on host
4.3.2.1 via L2TPv3 to the bridge br
-lan
2571 on the remote Linux host
1.2.3.4:
2573 # Setup tunnel on linux host
using raw ip as encapsulation
2575 ip l2tp add tunnel remote
4.3.2.1 local
1.2.3.4 tunnel_id
1 peer_tunnel_id
1 \
2576 encap udp udp_sport
16384 udp_dport
16384
2577 ip l2tp add session tunnel_id
1 name vmtunnel0 session_id \
2578 0xFFFFFFFF peer_session_id
0xFFFFFFFF
2579 ifconfig vmtunnel0 mtu
1500
2580 ifconfig vmtunnel0 up
2581 brctl addif br
-lan vmtunnel0
2585 # launch QEMU instance
- if your network has reorder or is very lossy add
,pincounter
2587 qemu
-system
-i386 linux
.img
-device e1000
,netdev
=n1 \
2588 -netdev l2tpv3
,id
=n1
,src
=4.2.3.1,dst
=1.2.3.4,udp
,srcport
=16384,dstport
=16384,rxsession
=0xffffffff,txsession
=0xffffffff,counter
2592 @item
-netdev vde
,id
=@
var{id
}[,sock
=@
var{socketpath
}][,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
2593 Configure VDE backend to connect to PORT @
var{n
} of a vde
switch running on host and
2594 listening
for incoming connections on @
var{socketpath
}. Use GROUP @
var{groupname
}
2595 and MODE @
var{octalmode
} to change
default ownership and permissions
for
2596 communication port
. This option is only available
if QEMU has been compiled
2597 with vde support enabled
.
2602 vde_switch
-F
-sock
/tmp
/myswitch
2603 # launch QEMU instance
2604 qemu
-system
-i386 linux
.img
-nic vde
,sock
=/tmp
/myswitch
2607 @item
-netdev vhost
-user
,chardev
=@
var{id
}[,vhostforce
=on|off
][,queues
=n
]
2609 Establish a vhost
-user netdev
, backed by a chardev @
var{id
}. The chardev should
2610 be a unix domain socket backed one
. The vhost
-user uses a specifically defined
2611 protocol to pass vhost ioctl replacement messages to an application on the other
2612 end of the socket
. On non
-MSIX guests
, the feature can be forced with
2613 @
var{vhostforce
}. Use
'queues=@var{n}' to specify the number of queues to
2614 be created
for multiqueue vhost
-user
.
2618 qemu
-m
512 -object memory
-backend
-file
,id
=mem
,size
=512M
,mem
-path
=/hugetlbfs
,share
=on \
2619 -numa node
,memdev
=mem \
2620 -chardev socket
,id
=chr0
,path
=/path
/to
/socket \
2621 -netdev type
=vhost
-user
,id
=net0
,chardev
=chr0 \
2622 -device virtio
-net
-pci
,netdev
=net0
2625 @item
-netdev hubport
,id
=@
var{id
},hubid
=@
var{hubid
}[,netdev
=@
var{nd
}]
2627 Create a hub port on the emulated hub with ID @
var{hubid
}.
2629 The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2630 single netdev
. Alternatively
, you can also connect the hubport to another
2631 netdev with ID @
var{nd
} by
using the @option
{netdev
=@
var{nd
}} option
.
2633 @item
-net nic
[,netdev
=@
var{nd
}][,macaddr
=@
var{mac
}][,model
=@
var{type
}] [,name
=@
var{name
}][,addr
=@
var{addr
}][,vectors
=@
var{v
}]
2635 Legacy option to configure or create an on
-board (or machine
default) Network
2636 Interface
Card(NIC
) and connect it either to the emulated hub with ID
0 (i
.e
.
2637 the
default hub
), or to the netdev @
var{nd
}.
2638 The NIC is an e1000 by
default on the PC target
. Optionally
, the MAC address
2639 can be changed to @
var{mac
}, the device address set to @
var{addr
} (PCI cards
2640 only
), and a @
var{name
} can be assigned
for use
in monitor commands
.
2641 Optionally
, for PCI cards
, you can specify the number @
var{v
} of MSI
-X vectors
2642 that the card should have
; this option currently only affects virtio cards
; set
2643 @
var{v
} = 0 to disable MSI
-X
. If no @option
{-net
} option is specified
, a single
2644 NIC is created
. QEMU can emulate several different models of network card
.
2645 Use @code
{-net nic
,model
=help
} for a list of available devices
for your target
.
2647 @item
-net user|tap|bridge|socket|l2tpv3|vde
[,...][,name
=@
var{name
}]
2648 Configure a host network
backend (with the options corresponding to the same
2649 @option
{-netdev
} option
) and connect it to the emulated hub
0 (the
default
2650 hub
). Use @
var{name
} to specify the name of the hub port
.
2658 DEFHEADING(Character device options
:)
2660 DEF("chardev", HAS_ARG
, QEMU_OPTION_chardev
,
2662 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2663 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2664 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n"
2665 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n"
2666 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n"
2667 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2668 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2669 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2670 " [,logfile=PATH][,logappend=on|off]\n"
2671 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2672 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2673 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2674 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2675 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2676 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2678 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2679 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2681 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2682 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2684 #ifdef CONFIG_BRLAPI
2685 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2687 #
if defined(__linux__
) ||
defined(__sun__
) ||
defined(__FreeBSD__
) \
2688 ||
defined(__NetBSD__
) ||
defined(__OpenBSD__
) ||
defined(__DragonFly__
)
2689 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2690 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2692 #
if defined(__linux__
) ||
defined(__FreeBSD__
) ||
defined(__DragonFly__
)
2693 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2694 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2696 #
if defined(CONFIG_SPICE
)
2697 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2698 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2705 The general form of a character device option is
:
2707 @item
-chardev @
var{backend
},id
=@
var{id
}[,mux
=on|off
][,@
var{options
}]
2728 The specific backend will determine the applicable options
.
2730 Use @code
{-chardev help
} to print all available chardev backend types
.
2732 All devices must have an id
, which can be any string up to
127 characters long
.
2733 It is used to uniquely identify
this device
in other command line directives
.
2735 A character device may be used
in multiplexing mode by multiple front
-ends
.
2736 Specify @option
{mux
=on
} to enable
this mode
.
2737 A multiplexer is a
"1:N" device
, and
here the
"1" end is your specified chardev
2738 backend
, and the
"N" end is the various parts of QEMU that can talk to a chardev
.
2739 If you create a chardev with @option
{id
=myid
} and @option
{mux
=on
}, QEMU will
2740 create a multiplexer with your specified ID
, and you can then configure multiple
2741 front ends to use that chardev ID
for their input
/output
. Up to four different
2742 front ends can be connected to a single multiplexed chardev
. (Without
2743 multiplexing enabled
, a chardev can only be used by a single front end
.)
2744 For instance you could use
this to allow a single stdio chardev to be used by
2745 two serial ports and the QEMU monitor
:
2748 -chardev stdio
,mux
=on
,id
=char0 \
2749 -mon chardev
=char0
,mode
=readline \
2750 -serial chardev
:char0 \
2751 -serial chardev
:char0
2754 You can have more than one multiplexer
in a system configuration
; for instance
2755 you could have a TCP port multiplexed between UART
0 and UART
1, and stdio
2756 multiplexed between the QEMU monitor and a parallel port
:
2759 -chardev stdio
,mux
=on
,id
=char0 \
2760 -mon chardev
=char0
,mode
=readline \
2761 -parallel chardev
:char0 \
2762 -chardev tcp
,...,mux
=on
,id
=char1 \
2763 -serial chardev
:char1 \
2764 -serial chardev
:char1
2767 When you
're using a multiplexed character device, some escape sequences are
2768 interpreted in the input. @xref{mux_keys, Keys in the character backend
2771 Note that some other command line options may implicitly create multiplexed
2772 character backends; for instance @option{-serial mon:stdio} creates a
2773 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2774 and @option{-nographic} also multiplexes the console and the monitor to
2777 There is currently no support for multiplexing in the other direction
2778 (where a single QEMU front end takes input and output from multiple chardevs).
2780 Every backend supports the @option{logfile} option, which supplies the path
2781 to a file to record all data transmitted via the backend. The @option{logappend}
2782 option controls whether the log file will be truncated or appended to when
2787 The available backends are:
2790 @item -chardev null,id=@var{id}
2791 A void device. This device will not emit any data, and will drop any data it
2792 receives. The null backend does not take any options.
2794 @item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,websocket][,reconnect=@var{seconds}][,tls-creds=@var{id}][,tls-authz=@var{id}]
2796 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2797 unix socket will be created if @option{path} is specified. Behaviour is
2798 undefined if TCP options are specified for a unix socket.
2800 @option{server} specifies that the socket shall be a listening socket.
2802 @option{nowait} specifies that QEMU should not block waiting for a client to
2803 connect to a listening socket.
2805 @option{telnet} specifies that traffic on the socket should interpret telnet
2808 @option{websocket} specifies that the socket uses WebSocket protocol for
2811 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2812 the remote end goes away. qemu will delay this many seconds and then attempt
2813 to reconnect. Zero disables reconnecting, and is the default.
2815 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2816 and specifies the id of the TLS credentials to use for the handshake. The
2817 credentials must be previously created with the @option{-object tls-creds}
2820 @option{tls-auth} provides the ID of the QAuthZ authorization object against
2821 which the client's x509 distinguished name will be validated
. This object is
2822 only resolved at time of use
, so can be deleted and recreated on the fly
2823 while the chardev server is active
. If missing
, it will
default to denying
2826 TCP and unix socket options are given below
:
2830 @item TCP options
: port
=@
var{port
}[,host
=@
var{host
}][,to
=@
var{to
}][,ipv4
][,ipv6
][,nodelay
]
2832 @option
{host
} for a listening socket specifies the local address to be bound
.
2833 For a connecting socket species the remote host to connect to
. @option
{host
} is
2834 optional
for listening sockets
. If not specified it defaults to @code
{0.0.0.0}.
2836 @option
{port
} for a listening socket specifies the local port to be bound
. For a
2837 connecting socket specifies the port on the remote host to connect to
.
2838 @option
{port
} can be given as either a port number or a service name
.
2839 @option
{port
} is required
.
2841 @option
{to
} is only relevant to listening sockets
. If it is specified
, and
2842 @option
{port
} cannot be bound
, QEMU will attempt to bind to subsequent ports up
2843 to and including @option
{to
} until it succeeds
. @option
{to
} must be specified
2846 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2847 If neither is specified the socket may use either protocol
.
2849 @option
{nodelay
} disables the Nagle algorithm
.
2851 @item unix options
: path
=@
var{path
}
2853 @option
{path
} specifies the local path of the unix socket
. @option
{path
} is
2858 @item
-chardev udp
,id
=@
var{id
}[,host
=@
var{host
}],port
=@
var{port
}[,localaddr
=@
var{localaddr
}][,localport
=@
var{localport
}][,ipv4
][,ipv6
]
2860 Sends all traffic from the guest to a remote host over UDP
.
2862 @option
{host
} specifies the remote host to connect to
. If not specified it
2863 defaults to @code
{localhost
}.
2865 @option
{port
} specifies the port on the remote host to connect to
. @option
{port
}
2868 @option
{localaddr
} specifies the local address to bind to
. If not specified it
2869 defaults to @code
{0.0.0.0}.
2871 @option
{localport
} specifies the local port to bind to
. If not specified any
2872 available local port will be used
.
2874 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2875 If neither is specified the device may use either protocol
.
2877 @item
-chardev msmouse
,id
=@
var{id
}
2879 Forward QEMU
's emulated msmouse events to the guest. @option{msmouse} does not
2882 @item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2884 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2887 @option{width} and @option{height} specify the width and height respectively of
2888 the console, in pixels.
2890 @option{cols} and @option{rows} specify that the console be sized to fit a text
2891 console with the given dimensions.
2893 @item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2895 Create a ring buffer with fixed size @option{size}.
2896 @var{size} must be a power of two and defaults to @code{64K}.
2898 @item -chardev file,id=@var{id},path=@var{path}
2900 Log all traffic received from the guest to a file.
2902 @option{path} specifies the path of the file to be opened. This file will be
2903 created if it does not already exist, and overwritten if it does. @option{path}
2906 @item -chardev pipe,id=@var{id},path=@var{path}
2908 Create a two-way connection to the guest. The behaviour differs slightly between
2909 Windows hosts and other hosts:
2911 On Windows, a single duplex pipe will be created at
2912 @file{\\.pipe\@option{path}}.
2914 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2915 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2916 received by the guest. Data written by the guest can be read from
2917 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2920 @option{path} forms part of the pipe path as described above. @option{path} is
2923 @item -chardev console,id=@var{id}
2925 Send traffic from the guest to QEMU's standard output
. @option
{console
} does not
2928 @option
{console
} is only available on Windows hosts
.
2930 @item
-chardev serial
,id
=@
var{id
},path
=@option
{path
}
2932 Send traffic from the guest to a serial device on the host
.
2934 On Unix hosts serial will actually accept any tty device
,
2935 not only serial lines
.
2937 @option
{path
} specifies the name of the serial device to open
.
2939 @item
-chardev pty
,id
=@
var{id
}
2941 Create a
new pseudo
-terminal on the host and connect to it
. @option
{pty
} does
2942 not take any options
.
2944 @option
{pty
} is not available on Windows hosts
.
2946 @item
-chardev stdio
,id
=@
var{id
}[,signal
=on|off
]
2947 Connect to standard input and standard output of the QEMU process
.
2949 @option
{signal
} controls
if signals are enabled on the terminal
, that includes
2950 exiting QEMU with the key sequence @key
{Control
-c
}. This option is enabled by
2951 default, use @option
{signal
=off
} to disable it
.
2953 @item
-chardev braille
,id
=@
var{id
}
2955 Connect to a local BrlAPI server
. @option
{braille
} does not take any options
.
2957 @item
-chardev tty
,id
=@
var{id
},path
=@
var{path
}
2959 @option
{tty
} is only available on Linux
, Sun
, FreeBSD
, NetBSD
, OpenBSD and
2960 DragonFlyBSD hosts
. It is an alias
for @option
{serial
}.
2962 @option
{path
} specifies the path to the tty
. @option
{path
} is required
.
2964 @item
-chardev parallel
,id
=@
var{id
},path
=@
var{path
}
2965 @itemx
-chardev parport
,id
=@
var{id
},path
=@
var{path
}
2967 @option
{parallel
} is only available on Linux
, FreeBSD and DragonFlyBSD hosts
.
2969 Connect to a local parallel port
.
2971 @option
{path
} specifies the path to the parallel port device
. @option
{path
} is
2974 @item
-chardev spicevmc
,id
=@
var{id
},debug
=@
var{debug
},name
=@
var{name
}
2976 @option
{spicevmc
} is only available when spice support is built
in.
2978 @option
{debug
} debug level
for spicevmc
2980 @option
{name
} name of spice channel to connect to
2982 Connect to a spice virtual machine channel
, such as vdiport
.
2984 @item
-chardev spiceport
,id
=@
var{id
},debug
=@
var{debug
},name
=@
var{name
}
2986 @option
{spiceport
} is only available when spice support is built
in.
2988 @option
{debug
} debug level
for spicevmc
2990 @option
{name
} name of spice port to connect to
2992 Connect to a spice port
, allowing a Spice client to handle the traffic
2993 identified by a
name (preferably a fqdn
).
3001 DEFHEADING(Bluetooth(R
) options
:)
3006 DEF("bt", HAS_ARG
, QEMU_OPTION_bt
, \
3007 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
3008 "-bt hci,host[:id]\n" \
3009 " use host's HCI with the given name\n" \
3010 "-bt hci[,vlan=n]\n" \
3011 " emulate a standard HCI in virtual scatternet 'n'\n" \
3012 "-bt vhci[,vlan=n]\n" \
3013 " add host computer to virtual scatternet 'n' using VHCI\n" \
3014 "-bt device:dev[,vlan=n]\n" \
3015 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
3020 Defines the
function of the corresponding Bluetooth HCI
. -bt options
3021 are matched with the HCIs present
in the chosen machine type
. For
3022 example when emulating a machine with only one HCI built into it
, only
3023 the first @code
{-bt hci
[...]} option is valid and defines the HCI
's
3024 logic. The Transport Layer is decided by the machine type. Currently
3025 the machines @code{n800} and @code{n810} have one HCI and all other
3028 Note: This option and the whole bluetooth subsystem is considered as deprecated.
3029 If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where
3030 you describe your usecase.
3033 The following three types are recognized:
3037 (default) The corresponding Bluetooth HCI assumes no internal logic
3038 and will not respond to any HCI commands or emit events.
3040 @item -bt hci,host[:@var{id}]
3041 (@code{bluez} only) The corresponding HCI passes commands / events
3042 to / from the physical HCI identified by the name @var{id} (default:
3043 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
3044 capable systems like Linux.
3046 @item -bt hci[,vlan=@var{n}]
3047 Add a virtual, standard HCI that will participate in the Bluetooth
3048 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
3049 VLANs, devices inside a bluetooth network @var{n} can only communicate
3050 with other devices in the same network (scatternet).
3053 @item -bt vhci[,vlan=@var{n}]
3054 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
3055 to the host bluetooth stack instead of to the emulated target. This
3056 allows the host and target machines to participate in a common scatternet
3057 and communicate. Requires the Linux @code{vhci} driver installed. Can
3058 be used as following:
3061 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
3064 @item -bt device:@var{dev}[,vlan=@var{n}]
3065 Emulate a bluetooth device @var{dev} and place it in network @var{n}
3066 (default @code{0}). QEMU can only emulate one type of bluetooth devices
3071 Virtual wireless keyboard implementing the HIDP bluetooth profile.
3081 DEFHEADING(TPM device options:)
3083 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
3084 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
3085 " use path to provide path to a character device; default is /dev/tpm0\n"
3086 " use cancel-path to provide path to TPM's cancel sysfs entry
; if\n"
3087 " not provided it will be searched
for in /sys
/class/misc
/tpm?
/device
\n"
3088 "-tpmdev emulator
,id
=id
,chardev
=dev
\n"
3089 " configure the TPM device
using chardev backend
\n",
3093 The general form of a TPM device option is:
3096 @item -tpmdev @var{backend},id=@var{id}[,@var{options}]
3099 The specific backend type will determine the applicable options.
3100 The @code{-tpmdev} option creates the TPM backend and requires a
3101 @code{-device} option that specifies the TPM frontend interface model.
3103 Use @code{-tpmdev help} to print all available TPM backend types.
3107 The available backends are:
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
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
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:
3143 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
3145 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
3146 @code{tpmdev=tpm0} in the device option.
3148 @item -tpmdev emulator,id=@var{id},chardev=@var{dev}
3150 (Linux-host only) Enable access to a TPM emulator using Unix domain socket based
3153 @option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
3155 To create a TPM emulator backend device with chardev socket backend:
3158 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
3171 DEFHEADING(Linux/Multiboot boot specific:)
3174 When using these options, you can use a given Linux or Multiboot
3175 kernel without installing it in the disk image. It can be useful
3176 for easier testing of various kernels.
3181 DEF("kernel
", HAS_ARG, QEMU_OPTION_kernel, \
3182 "-kernel bzImage use
'bzImage' as kernel image
\n", QEMU_ARCH_ALL)
3184 @item -kernel @var{bzImage}
3186 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
3187 or in multiboot format.
3190 DEF("append
", HAS_ARG, QEMU_OPTION_append, \
3191 "-append cmdline use
'cmdline' as kernel command line
\n", QEMU_ARCH_ALL)
3193 @item -append @var{cmdline}
3195 Use @var{cmdline} as kernel command line
3198 DEF("initrd
", HAS_ARG, QEMU_OPTION_initrd, \
3199 "-initrd file use
'file' as initial ram disk
\n", QEMU_ARCH_ALL)
3201 @item -initrd @var{file}
3203 Use @var{file} as initial ram disk.
3205 @item -initrd "@
var{file1
} arg
=foo
,@
var{file2
}"
3207 This syntax is only available with multiboot.
3209 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3213 DEF("dtb
", HAS_ARG, QEMU_OPTION_dtb, \
3214 "-dtb file use
'file' as device tree image
\n", QEMU_ARCH_ALL)
3216 @item -dtb @var{file}
3218 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3227 DEFHEADING(Debug/Expert options:)
3232 DEF("fw_cfg
", HAS_ARG, QEMU_OPTION_fwcfg,
3233 "-fw_cfg
[name
=]<name
>,file
=<file
>\n"
3234 " add named fw_cfg entry with contents from file
\n"
3235 "-fw_cfg
[name
=]<name
>,string
=<str
>\n"
3236 " add named fw_cfg entry with contents from string
\n",
3240 @item -fw_cfg [name=]@var{name},file=@var{file}
3242 Add named fw_cfg entry with contents from file @var{file}.
3244 @item -fw_cfg [name=]@var{name},string=@var{str}
3245 Add named fw_cfg entry with contents from string @var{str}.
3247 The terminating NUL character of the contents of @var{str} will not be
3248 included as part of the fw_cfg item data. To insert contents with
3249 embedded NUL characters, you have to use the @var{file} parameter.
3251 The fw_cfg entries are passed by QEMU through to the guest.
3255 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3257 creates an fw_cfg entry named opt/com.mycompany/blob with contents
3262 DEF("serial
", HAS_ARG, QEMU_OPTION_serial, \
3263 "-serial dev redirect the serial port to char device
'dev'\n",
3266 @item -serial @var{dev}
3268 Redirect the virtual serial port to host character device
3269 @var{dev}. The default device is @code{vc} in graphical mode and
3270 @code{stdio} in non graphical mode.
3272 This option can be used several times to simulate up to 4 serial
3275 Use @code{-serial none} to disable all serial ports.
3277 Available character devices are:
3279 @item vc[:@var{W}x@var{H}]
3280 Virtual console. Optionally, a width and height can be given in pixel with
3284 It is also possible to specify width or height in characters:
3289 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3291 No device is allocated.
3294 @item chardev:@var{id}
3295 Use a named character device defined with the @code{-chardev} option.
3297 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3298 parameters are set according to the emulated ones.
3299 @item /dev/parport@var{N}
3300 [Linux only, parallel port only] Use host parallel port
3301 @var{N}. Currently SPP and EPP parallel port features can be used.
3302 @item file:@var{filename}
3303 Write output to @var{filename}. No character can be read.
3305 [Unix only] standard input/output
3306 @item pipe:@var{filename}
3307 name pipe @var{filename}
3309 [Windows only] Use host serial port @var{n}
3310 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3311 This implements UDP Net Console.
3312 When @var{remote_host} or @var{src_ip} are not specified
3313 they default to @code{0.0.0.0}.
3314 When not using a specified @var{src_port} a random port is automatically chosen.
3316 If you just want a simple readonly console you can use @code{netcat} or
3317 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3318 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3319 will appear in the netconsole session.
3321 If you plan to send characters back via netconsole or you want to stop
3322 and start QEMU a lot of times, you should have QEMU use the same
3323 source port each time by using something like @code{-serial
3324 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3325 version of netcat which can listen to a TCP port and send and receive
3326 characters via udp. If you have a patched version of netcat which
3327 activates telnet remote echo and single char transfer, then you can
3328 use the following options to set up a netcat redirector to allow
3329 telnet on port 5555 to access the QEMU port.
3332 -serial udp::4555@@:4556
3333 @item netcat options:
3334 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3335 @item telnet options:
3339 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3340 The TCP Net Console has two modes of operation. It can send the serial
3341 I/O to a location or wait for a connection from a location. By default
3342 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3343 the @var{server} option QEMU will wait for a client socket application
3344 to connect to the port before continuing, unless the @code{nowait}
3345 option was specified. The @code{nodelay} option disables the Nagle buffering
3346 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3347 set, if the connection goes down it will attempt to reconnect at the
3348 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3349 one TCP connection at a time is accepted. You can use @code{telnet} to
3350 connect to the corresponding character device.
3352 @item Example to send tcp console to 192.168.0.2 port 4444
3353 -serial tcp:192.168.0.2:4444
3354 @item Example to listen and wait on port 4444 for connection
3355 -serial tcp::4444,server
3356 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3357 -serial tcp:192.168.0.100:4444,server,nowait
3360 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3361 The telnet protocol is used instead of raw tcp sockets. The options
3362 work the same as if you had specified @code{-serial tcp}. The
3363 difference is that the port acts like a telnet server or client using
3364 telnet option negotiation. This will also allow you to send the
3365 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3366 sequence. Typically in unix telnet you do it with Control-] and then
3367 type "send
break" followed by pressing the enter key.
3369 @item websocket:@var{host}:@var{port},server[,nowait][,nodelay]
3370 The WebSocket protocol is used instead of raw tcp socket. The port acts as
3371 a WebSocket server. Client mode is not supported.
3373 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3374 A unix domain socket is used instead of a tcp socket. The option works the
3375 same as if you had specified @code{-serial tcp} except the unix domain socket
3376 @var{path} is used for connections.
3378 @item mon:@var{dev_string}
3379 This is a special option to allow the monitor to be multiplexed onto
3380 another serial port. The monitor is accessed with key sequence of
3381 @key{Control-a} and then pressing @key{c}.
3382 @var{dev_string} should be any one of the serial devices specified
3383 above. An example to multiplex the monitor onto a telnet server
3384 listening on port 4444 would be:
3386 @item -serial mon:telnet::4444,server,nowait
3388 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3389 QEMU any more but will be passed to the guest instead.
3392 Braille device. This will use BrlAPI to display the braille output on a real
3396 Three button serial mouse. Configure the guest to use Microsoft protocol.
3400 DEF("parallel
", HAS_ARG, QEMU_OPTION_parallel, \
3401 "-parallel dev redirect the parallel port to char device
'dev'\n",
3404 @item -parallel @var{dev}
3406 Redirect the virtual parallel port to host device @var{dev} (same
3407 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3408 be used to use hardware devices connected on the corresponding host
3411 This option can be used several times to simulate up to 3 parallel
3414 Use @code{-parallel none} to disable all parallel ports.
3417 DEF("monitor
", HAS_ARG, QEMU_OPTION_monitor, \
3418 "-monitor dev redirect the monitor to char device
'dev'\n",
3421 @item -monitor @var{dev}
3423 Redirect the monitor to host device @var{dev} (same devices as the
3425 The default device is @code{vc} in graphical mode and @code{stdio} in
3427 Use @code{-monitor none} to disable the default monitor.
3429 DEF("qmp
", HAS_ARG, QEMU_OPTION_qmp, \
3430 "-qmp dev like
-monitor but opens
in 'control' mode
\n",
3433 @item -qmp @var{dev}
3435 Like -monitor but opens in 'control' mode.
3437 DEF("qmp
-pretty
", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3438 "-qmp
-pretty dev like
-qmp but uses pretty JSON formatting
\n",
3441 @item -qmp-pretty @var{dev}
3443 Like -qmp but uses pretty JSON formatting.
3446 DEF("mon
", HAS_ARG, QEMU_OPTION_mon, \
3447 "-mon
[chardev
=]name
[,mode
=readline|control
][,pretty
[=on|off
]]\n", QEMU_ARCH_ALL)
3449 @item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3451 Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3452 easing human reading and debugging.
3455 DEF("debugcon
", HAS_ARG, QEMU_OPTION_debugcon, \
3456 "-debugcon dev redirect the debug console to char device
'dev'\n",
3459 @item -debugcon @var{dev}
3461 Redirect the debug console to host device @var{dev} (same devices as the
3462 serial port). The debug console is an I/O port which is typically port
3463 0xe9; writing to that I/O port sends output to this device.
3464 The default device is @code{vc} in graphical mode and @code{stdio} in
3468 DEF("pidfile
", HAS_ARG, QEMU_OPTION_pidfile, \
3469 "-pidfile file write PID to
'file'\n", QEMU_ARCH_ALL)
3471 @item -pidfile @var{file}
3473 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3477 DEF("singlestep
", 0, QEMU_OPTION_singlestep, \
3478 "-singlestep always run
in singlestep mode
\n", QEMU_ARCH_ALL)
3482 Run the emulation in single step mode.
3485 DEF("preconfig
", 0, QEMU_OPTION_preconfig, \
3486 "--preconfig pause QEMU before machine is
initialized (experimental
)\n",
3491 Pause QEMU for interactive configuration before the machine is created,
3492 which allows querying and configuring properties that will affect
3493 machine initialization. Use QMP command 'x-exit-preconfig' to exit
3494 the preconfig state and move to the next state (i.e. run guest if -S
3495 isn't used or pause the second time if -S is used). This option is
3499 DEF("S
", 0, QEMU_OPTION_S, \
3500 "-S freeze CPU at
startup (use
'c' to start execution
)\n",
3505 Do not start CPU at startup (you must type 'c' in the monitor).
3508 DEF("realtime
", HAS_ARG, QEMU_OPTION_realtime,
3509 "-realtime
[mlock
=on|off
]\n"
3510 " run qemu with realtime features
\n"
3511 " mlock
=on|off controls mlock
support (default: on
)\n",
3514 @item -realtime mlock=on|off
3516 Run qemu with realtime features.
3517 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3518 (enabled by default).
3521 DEF("overcommit
", HAS_ARG, QEMU_OPTION_overcommit,
3522 "-overcommit
[mem
-lock
=on|off
][cpu
-pm
=on|off
]\n"
3523 " run qemu with overcommit hints
\n"
3524 " mem
-lock
=on|off controls memory lock
support (default: off
)\n"
3525 " cpu
-pm
=on|off controls cpu power
management (default: off
)\n",
3528 @item -overcommit mem-lock=on|off
3529 @item -overcommit cpu-pm=on|off
3531 Run qemu with hints about host resource overcommit. The default is
3532 to assume that host overcommits all resources.
3534 Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled
3535 by default). This works when host memory is not overcommitted and reduces the
3536 worst-case latency for guest. This is equivalent to @option{realtime}.
3538 Guest ability to manage power state of host cpus (increasing latency for other
3539 processes on the same host cpu, but decreasing latency for guest) can be
3540 enabled via @option{cpu-pm=on} (disabled by default). This works best when
3541 host CPU is not overcommitted. When used, host estimates of CPU cycle and power
3542 utilization will be incorrect, not taking into account guest idle time.
3545 DEF("gdb
", HAS_ARG, QEMU_OPTION_gdb, \
3546 "-gdb dev wait
for gdb connection on
'dev'\n", QEMU_ARCH_ALL)
3548 @item -gdb @var{dev}
3550 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3551 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3552 stdio are reasonable use case. The latter is allowing to start QEMU from
3553 within gdb and establish the connection via a pipe:
3555 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3559 DEF("s
", 0, QEMU_OPTION_s, \
3560 "-s shorthand
for -gdb tcp
::" DEFAULT_GDBSTUB_PORT "\n",
3565 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3566 (@pxref{gdb_usage}).
3569 DEF("d
", HAS_ARG, QEMU_OPTION_d, \
3570 "-d item1
,... enable logging of specified
items (use
'-d help' for a list of log items
)\n",
3573 @item -d @var{item1}[,...]
3575 Enable logging of specified items. Use '-d help' for a list of log items.
3578 DEF("D
", HAS_ARG, QEMU_OPTION_D, \
3579 "-D logfile output log to
logfile (default stderr
)\n",
3582 @item -D @var{logfile}
3584 Output log in @var{logfile} instead of to stderr
3587 DEF("dfilter
", HAS_ARG, QEMU_OPTION_DFILTER, \
3588 "-dfilter range
,.. filter debug output to range of
addresses (useful
for -d cpu
,exec
,etc
..)\n",
3591 @item -dfilter @var{range1}[,...]
3593 Filter debug output to that relevant to a range of target addresses. The filter
3594 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3595 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3596 addresses and sizes required. For example:
3598 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3600 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3601 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3602 block starting at 0xffffffc00005f000.
3605 DEF("L
", HAS_ARG, QEMU_OPTION_L, \
3606 "-L path set the directory
for the BIOS
, VGA BIOS and keymaps
\n",
3611 Set the directory for the BIOS, VGA BIOS and keymaps.
3613 To list all the data directories, use @code{-L help}.
3616 DEF("bios
", HAS_ARG, QEMU_OPTION_bios, \
3617 "-bios file set the filename
for the BIOS
\n", QEMU_ARCH_ALL)
3619 @item -bios @var{file}
3621 Set the filename for the BIOS.
3624 DEF("enable
-kvm
", 0, QEMU_OPTION_enable_kvm, \
3625 "-enable
-kvm enable KVM full virtualization support
\n", QEMU_ARCH_ALL)
3629 Enable KVM full virtualization support. This option is only available
3630 if KVM support is enabled when compiling.
3633 DEF("xen
-domid
", HAS_ARG, QEMU_OPTION_xen_domid,
3634 "-xen
-domid id specify xen guest domain id
\n", QEMU_ARCH_ALL)
3635 DEF("xen
-attach
", 0, QEMU_OPTION_xen_attach,
3636 "-xen
-attach attach to existing xen domain
\n"
3637 " libxl will use
this when starting QEMU
\n",
3639 DEF("xen
-domid
-restrict
", 0, QEMU_OPTION_xen_domid_restrict,
3640 "-xen
-domid
-restrict restrict set of available xen operations
\n"
3641 " to specified domain id
. (Does not affect
\n"
3642 " xenpv machine type
).\n",
3645 @item -xen-domid @var{id}
3647 Specify xen guest domain @var{id} (XEN only).
3650 Attach to existing xen domain.
3651 libxl will use this when starting QEMU (XEN only).
3652 @findex -xen-domid-restrict
3653 Restrict set of available xen operations to specified domain id (XEN only).
3656 DEF("no
-reboot
", 0, QEMU_OPTION_no_reboot, \
3657 "-no
-reboot exit instead of rebooting
\n", QEMU_ARCH_ALL)
3661 Exit instead of rebooting.
3664 DEF("no
-shutdown
", 0, QEMU_OPTION_no_shutdown, \
3665 "-no
-shutdown stop before shutdown
\n", QEMU_ARCH_ALL)
3668 @findex -no-shutdown
3669 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3670 This allows for instance switching to monitor to commit changes to the
3674 DEF("loadvm
", HAS_ARG, QEMU_OPTION_loadvm, \
3675 "-loadvm
[tag|id
]\n" \
3676 " start right away with a saved
state (loadvm
in monitor
)\n",
3679 @item -loadvm @var{file}
3681 Start right away with a saved state (@code{loadvm} in monitor)
3685 DEF("daemonize
", 0, QEMU_OPTION_daemonize, \
3686 "-daemonize daemonize QEMU after initializing
\n", QEMU_ARCH_ALL)
3691 Daemonize the QEMU process after initialization. QEMU will not detach from
3692 standard IO until it is ready to receive connections on any of its devices.
3693 This option is a useful way for external programs to launch QEMU without having
3694 to cope with initialization race conditions.
3697 DEF("option
-rom
", HAS_ARG, QEMU_OPTION_option_rom, \
3698 "-option
-rom rom load a file
, rom
, into the option ROM space
\n",
3701 @item -option-rom @var{file}
3703 Load the contents of @var{file} as an option ROM.
3704 This option is useful to load things like EtherBoot.
3707 DEF("rtc
", HAS_ARG, QEMU_OPTION_rtc, \
3708 "-rtc
[base
=utc|localtime|
<datetime
>][,clock
=host|rt|vm
][,driftfix
=none|slew
]\n" \
3709 " set the RTC base and clock
, enable drift fix
for clock
ticks (x86 only
)\n",
3714 @item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew]
3716 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3717 UTC or local time, respectively. @code{localtime} is required for correct date in
3718 MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the
3719 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3721 By default the RTC is driven by the host system time. This allows using of the
3722 RTC as accurate reference clock inside the guest, specifically if the host
3723 time is smoothly following an accurate external reference clock, e.g. via NTP.
3724 If you want to isolate the guest time from the host, you can set @option{clock}
3725 to @code{rt} instead, which provides a host monotonic clock if host support it.
3726 To even prevent the RTC from progressing during suspension, you can set @option{clock}
3727 to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in
3728 icount mode in order to preserve determinism; however, note that in icount mode
3729 the speed of the virtual clock is variable and can in general differ from the
3732 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3733 specifically with Windows' ACPI HAL. This option will try to figure out how
3734 many timer interrupts were not processed by the Windows guest and will
3738 DEF("icount
", HAS_ARG, QEMU_OPTION_icount, \
3739 "-icount
[shift
=N|auto
][,align
=on|off
][,sleep
=on|off
,rr
=record|replay
,rrfile
=<filename
>,rrsnapshot
=<snapshot
>]\n" \
3740 " enable virtual instruction counter with
2^N clock ticks per
\n" \
3741 " instruction
, enable aligning the host and virtual clocks
\n" \
3742 " or disable real time cpu sleeping
\n", QEMU_ARCH_ALL)
3744 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3746 Enable virtual instruction counter. The virtual cpu will execute one
3747 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3748 then the virtual cpu speed will be automatically adjusted to keep virtual
3749 time within a few seconds of real time.
3751 When the virtual cpu is sleeping, the virtual time will advance at default
3752 speed unless @option{sleep=on|off} is specified.
3753 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3754 instantly whenever the virtual cpu goes to sleep mode and will not advance
3755 if no timer is enabled. This behavior give deterministic execution times from
3756 the guest point of view.
3758 Note that while this option can give deterministic behavior, it does not
3759 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3760 order cores with complex cache hierarchies. The number of instructions
3761 executed often has little or no correlation with actual performance.
3763 @option{align=on} will activate the delay algorithm which will try
3764 to synchronise the host clock and the virtual clock. The goal is to
3765 have a guest running at the real frequency imposed by the shift option.
3766 Whenever the guest clock is behind the host clock and if
3767 @option{align=on} is specified then we print a message to the user
3768 to inform about the delay.
3769 Currently this option does not work when @option{shift} is @code{auto}.
3770 Note: The sync algorithm will work for those shift values for which
3771 the guest clock runs ahead of the host clock. Typically this happens
3772 when the shift value is high (how high depends on the host machine).
3774 When @option{rr} option is specified deterministic record/replay is enabled.
3775 Replay log is written into @var{filename} file in record mode and
3776 read from this file in replay mode.
3778 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3779 at the start of execution recording. In replay mode this option is used
3780 to load the initial VM state.
3783 DEF("watchdog
", HAS_ARG, QEMU_OPTION_watchdog, \
3784 "-watchdog model
\n" \
3785 " enable virtual hardware watchdog
[default=none
]\n",
3788 @item -watchdog @var{model}
3790 Create a virtual hardware watchdog device. Once enabled (by a guest
3791 action), the watchdog must be periodically polled by an agent inside
3792 the guest or else the guest will be restarted. Choose a model for
3793 which your guest has drivers.
3795 The @var{model} is the model of hardware watchdog to emulate. Use
3796 @code{-watchdog help} to list available hardware models. Only one
3797 watchdog can be enabled for a guest.
3799 The following models may be available:
3802 iBASE 700 is a very simple ISA watchdog with a single timer.
3804 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3805 dual-timer watchdog.
3807 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3808 (currently KVM only).
3812 DEF("watchdog
-action
", HAS_ARG, QEMU_OPTION_watchdog_action, \
3813 "-watchdog
-action reset|shutdown|poweroff|inject
-nmi|pause|debug|none
\n" \
3814 " action when watchdog fires
[default=reset
]\n",
3817 @item -watchdog-action @var{action}
3818 @findex -watchdog-action
3820 The @var{action} controls what QEMU will do when the watchdog timer
3823 @code{reset} (forcefully reset the guest).
3824 Other possible actions are:
3825 @code{shutdown} (attempt to gracefully shutdown the guest),
3826 @code{poweroff} (forcefully poweroff the guest),
3827 @code{inject-nmi} (inject a NMI into the guest),
3828 @code{pause} (pause the guest),
3829 @code{debug} (print a debug message and continue), or
3830 @code{none} (do nothing).
3832 Note that the @code{shutdown} action requires that the guest responds
3833 to ACPI signals, which it may not be able to do in the sort of
3834 situations where the watchdog would have expired, and thus
3835 @code{-watchdog-action shutdown} is not recommended for production use.
3840 @item -watchdog i6300esb -watchdog-action pause
3841 @itemx -watchdog ib700
3845 DEF("echr
", HAS_ARG, QEMU_OPTION_echr, \
3846 "-echr chr set terminal escape character instead of ctrl
-a
\n",
3850 @item -echr @var{numeric_ascii_value}
3852 Change the escape character used for switching to the monitor when using
3853 monitor and serial sharing. The default is @code{0x01} when using the
3854 @code{-nographic} option. @code{0x01} is equal to pressing
3855 @code{Control-a}. You can select a different character from the ascii
3856 control keys where 1 through 26 map to Control-a through Control-z. For
3857 instance you could use the either of the following to change the escape
3858 character to Control-t.
3865 DEF("show
-cursor
", 0, QEMU_OPTION_show_cursor, \
3866 "-show
-cursor show cursor
\n", QEMU_ARCH_ALL)
3869 @findex -show-cursor
3873 DEF("tb
-size
", HAS_ARG, QEMU_OPTION_tb_size, \
3874 "-tb
-size n set TB size
\n", QEMU_ARCH_ALL)
3876 @item -tb-size @var{n}
3881 DEF("incoming
", HAS_ARG, QEMU_OPTION_incoming, \
3882 "-incoming tcp
:[host
]:port
[,to
=maxport
][,ipv4
][,ipv6
]\n" \
3883 "-incoming rdma
:host
:port
[,ipv4
][,ipv6
]\n" \
3884 "-incoming unix
:socketpath
\n" \
3885 " prepare
for incoming migration
, listen on
\n" \
3886 " specified protocol and socket address
\n" \
3887 "-incoming fd
:fd
\n" \
3888 "-incoming exec
:cmdline
\n" \
3889 " accept incoming migration on given file descriptor
\n" \
3890 " or from given external command
\n" \
3891 "-incoming defer
\n" \
3892 " wait
for the URI to be specified via migrate_incoming
\n",
3895 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3896 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3898 Prepare for incoming migration, listen on a given tcp port.
3900 @item -incoming unix:@var{socketpath}
3901 Prepare for incoming migration, listen on a given unix socket.
3903 @item -incoming fd:@var{fd}
3904 Accept incoming migration from a given filedescriptor.
3906 @item -incoming exec:@var{cmdline}
3907 Accept incoming migration as an output from specified external command.
3909 @item -incoming defer
3910 Wait for the URI to be specified via migrate_incoming. The monitor can
3911 be used to change settings (such as migration parameters) prior to issuing
3912 the migrate_incoming to allow the migration to begin.
3915 DEF("only
-migratable
", 0, QEMU_OPTION_only_migratable, \
3916 "-only
-migratable allow only migratable devices
\n", QEMU_ARCH_ALL)
3918 @item -only-migratable
3919 @findex -only-migratable
3920 Only allow migratable devices. Devices will not be allowed to enter an
3924 DEF("nodefaults
", 0, QEMU_OPTION_nodefaults, \
3925 "-nodefaults don
't create default devices\n", QEMU_ARCH_ALL)
3929 Don't create
default devices
. Normally
, QEMU sets the
default devices like serial
3930 port
, parallel port
, virtual console
, monitor device
, VGA adapter
, floppy and
3931 CD
-ROM drive and others
. The @code
{-nodefaults
} option will disable all those
3936 DEF("chroot", HAS_ARG
, QEMU_OPTION_chroot
, \
3937 "-chroot dir chroot to dir just before starting the VM\n",
3941 @item
-chroot @
var{dir
}
3943 Immediately before starting guest execution
, chroot to the specified
3944 directory
. Especially useful
in combination with
-runas
.
3948 DEF("runas", HAS_ARG
, QEMU_OPTION_runas
, \
3949 "-runas user change to user id user just before starting the VM\n" \
3950 " user can be numeric uid:gid instead\n",
3954 @item
-runas @
var{user
}
3956 Immediately before starting guest execution
, drop root privileges
, switching
3957 to the specified user
.
3960 DEF("prom-env", HAS_ARG
, QEMU_OPTION_prom_env
,
3961 "-prom-env variable=value\n"
3962 " set OpenBIOS nvram variables\n",
3963 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
3965 @item
-prom
-env @
var{variable
}=@
var{value
}
3967 Set OpenBIOS nvram @
var{variable
} to given @
var{value
} (PPC
, SPARC only
).
3969 DEF("semihosting", 0, QEMU_OPTION_semihosting
,
3970 "-semihosting semihosting mode\n",
3971 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3972 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2
)
3975 @findex
-semihosting
3976 Enable semihosting
mode (ARM
, M68K
, Xtensa
, MIPS
, Nios II only
).
3978 DEF("semihosting-config", HAS_ARG
, QEMU_OPTION_semihosting_config
,
3979 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3980 " semihosting configuration\n",
3981 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3982 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2
)
3984 @item
-semihosting
-config
[enable
=on|off
][,target
=native|gdb|auto
][,arg
=str
[,...]]
3985 @findex
-semihosting
-config
3986 Enable and configure
semihosting (ARM
, M68K
, Xtensa
, MIPS
, Nios II only
).
3988 @item target
=@code
{native|gdb|auto
}
3989 Defines where the semihosting calls will be addressed
, to
QEMU (@code
{native
})
3990 or to
GDB (@code
{gdb
}). The
default is @code
{auto
}, which means @code
{gdb
}
3991 during debug sessions and @code
{native
} otherwise
.
3992 @item arg
=@
var{str1
},arg
=@
var{str2
},...
3993 Allows the user to pass input arguments
, and can be used multiple times to build
3994 up a list
. The old
-style @code
{-kernel
}/@code
{-append
} method of passing a
3995 command line is still supported
for backward compatibility
. If both the
3996 @code
{--semihosting
-config arg
} and the @code
{-kernel
}/@code
{-append
} are
3997 specified
, the former is passed to semihosting as it always takes precedence
.
4000 DEF("old-param", 0, QEMU_OPTION_old_param
,
4001 "-old-param old param mode\n", QEMU_ARCH_ARM
)
4004 @findex
-old
-param (ARM
)
4005 Old param
mode (ARM only
).
4008 DEF("sandbox", HAS_ARG
, QEMU_OPTION_sandbox
, \
4009 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
4010 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
4011 " Enable seccomp mode 2 system call filter (default 'off').\n" \
4012 " use 'obsolete' to allow obsolete system calls that are provided\n" \
4013 " by the kernel, but typically no longer used by modern\n" \
4014 " C library implementations.\n" \
4015 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
4016 " its privileges by blacklisting all set*uid|gid system calls.\n" \
4017 " The value 'children' will deny set*uid|gid system calls for\n" \
4018 " main QEMU process but will allow forks and execves to run unprivileged\n" \
4019 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
4020 " blacklisting *fork and execve\n" \
4021 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
4024 @item
-sandbox @
var{arg
}[,obsolete
=@
var{string
}][,elevateprivileges
=@
var{string
}][,spawn
=@
var{string
}][,resourcecontrol
=@
var{string
}]
4026 Enable Seccomp mode
2 system call filter
. 'on' will enable syscall filtering and
'off' will
4027 disable it
. The
default is
'off'.
4029 @item obsolete
=@
var{string
}
4030 Enable Obsolete system calls
4031 @item elevateprivileges
=@
var{string
}
4032 Disable set
*uid|gid system calls
4033 @item spawn
=@
var{string
}
4034 Disable
*fork and execve
4035 @item resourcecontrol
=@
var{string
}
4036 Disable process affinity and schedular priority
4040 DEF("readconfig", HAS_ARG
, QEMU_OPTION_readconfig
,
4041 "-readconfig <file>\n", QEMU_ARCH_ALL
)
4043 @item
-readconfig @
var{file
}
4045 Read device configuration from @
var{file
}. This approach is useful when you want to spawn
4046 QEMU process with many command line options but you don
't want to exceed the command line
4049 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
4050 "-writeconfig <file>\n"
4051 " read/write config file\n", QEMU_ARCH_ALL)
4053 @item -writeconfig @var{file}
4054 @findex -writeconfig
4055 Write device configuration to @var{file}. The @var{file} can be either filename to save
4056 command line and device configuration into file or dash @code{-}) character to print the
4057 output to stdout. This can be later used as input file for @code{-readconfig} option.
4060 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
4062 " do not load default user-provided config files at startup\n",
4065 @item -no-user-config
4066 @findex -no-user-config
4067 The @code{-no-user-config} option makes QEMU not load any of the user-provided
4068 config files on @var{sysconfdir}.
4071 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
4072 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
4073 " specify tracing options\n",
4076 HXCOMM This line is not accurate, as some sub-options are backend-specific but
4077 HXCOMM HX does not support conditional compilation of text.
4078 @item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
4080 @include qemu-option-trace.texi
4084 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
4085 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
4088 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
4089 "-enable-fips enable FIPS 140-2 compliance\n",
4094 @findex -enable-fips
4095 Enable FIPS 140-2 compliance mode.
4098 HXCOMM Deprecated by -machine accel=tcg property
4099 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
4101 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
4102 "-msg timestamp[=on|off]\n"
4103 " change the format of messages\n"
4104 " on|off controls leading timestamps (default:on)\n",
4107 @item -msg timestamp[=on|off]
4109 prepend a timestamp to each log message.(default:on)
4112 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
4113 "-dump-vmstate <file>\n"
4114 " Output vmstate information in JSON format to file.\n"
4115 " Use the scripts/vmstate-static-checker.py file to\n"
4116 " check for possible regressions in migration code\n"
4117 " by comparing two such vmstate dumps.\n",
4120 @item -dump-vmstate @var{file}
4121 @findex -dump-vmstate
4122 Dump json-encoded vmstate information for current machine type to file
4126 DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
4127 "-enable-sync-profile\n"
4128 " enable synchronization profiling\n",
4131 @item -enable-sync-profile
4132 @findex -enable-sync-profile
4133 Enable synchronization profiling.
4141 DEFHEADING(Generic object creation:)
4146 DEF("object", HAS_ARG, QEMU_OPTION_object,
4147 "-object TYPENAME[,PROP1=VALUE1,...]\n"
4148 " create a new object of type TYPENAME setting properties\n"
4149 " in the order they are specified. Note that the 'id
'\n"
4150 " property must be set. These objects are placed in the\n"
4151 " '/objects
' path.\n",
4154 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
4156 Create a new object of type @var{typename} setting properties
4157 in the order they are specified. Note that the 'id
'
4158 property must be set. These objects are placed in the
4163 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},align=@var{align}
4165 Creates a memory file backend object, which can be used to back
4166 the guest RAM with huge pages.
4168 The @option{id} parameter is a unique ID that will be used to reference this
4169 memory region when configuring the @option{-numa} argument.
4171 The @option{size} option provides the size of the memory region, and accepts
4172 common suffixes, eg @option{500M}.
4174 The @option{mem-path} provides the path to either a shared memory or huge page
4177 The @option{share} boolean option determines whether the memory
4178 region is marked as private to QEMU, or shared. The latter allows
4179 a co-operating external process to access the QEMU memory region.
4181 The @option{share} is also required for pvrdma devices due to
4182 limitations in the RDMA API provided by Linux.
4184 Setting share=on might affect the ability to configure NUMA
4185 bindings for the memory backend under some circumstances, see
4186 Documentation/vm/numa_memory_policy.txt on the Linux kernel
4187 source tree for additional details.
4189 Setting the @option{discard-data} boolean option to @var{on}
4190 indicates that file contents can be destroyed when QEMU exits,
4191 to avoid unnecessarily flushing data to the backing file. Note
4192 that @option{discard-data} is only an optimization, and QEMU
4193 might not discard file contents if it aborts unexpectedly or is
4194 terminated using SIGKILL.
4196 The @option{merge} boolean option enables memory merge, also known as
4197 MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
4198 memory deduplication.
4200 Setting the @option{dump} boolean option to @var{off} excludes the memory from
4201 core dumps. This feature is also known as MADV_DONTDUMP.
4203 The @option{prealloc} boolean option enables memory preallocation.
4205 The @option{host-nodes} option binds the memory range to a list of NUMA host
4208 The @option{policy} option sets the NUMA policy to one of the following values:
4214 @item @var{preferred}
4215 prefer the given host node list for allocation
4218 restrict memory allocation to the given host node list
4220 @item @var{interleave}
4221 interleave memory allocations across the given host node list
4224 The @option{align} option specifies the base address alignment when
4225 QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
4226 @option{2M}. Some backend store specified by @option{mem-path}
4227 requires an alignment different than the default one used by QEMU, eg
4228 the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4229 such cases, users can specify the required alignment via this option.
4231 The @option{pmem} option specifies whether the backing file specified
4232 by @option{mem-path} is in host persistent memory that can be accessed
4233 using the SNIA NVM programming model (e.g. Intel NVDIMM).
4234 If @option{pmem} is set to 'on
', QEMU will take necessary operations to
4235 guarantee the persistence of its own writes to @option{mem-path}
4236 (e.g. in vNVDIMM label emulation and live migration).
4237 Also, we will map the backend-file with MAP_SYNC flag, which ensures the
4238 file metadata is in sync for @option{mem-path} in case of host crash
4239 or a power failure. MAP_SYNC requires support from both the host kernel
4240 (since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted
4243 @item -object memory-backend-ram,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave}
4245 Creates a memory backend object, which can be used to back the guest RAM.
4246 Memory backend objects offer more control than the @option{-m} option that is
4247 traditionally used to define guest RAM. Please refer to
4248 @option{memory-backend-file} for a description of the options.
4250 @item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},seal=@var{on|off},hugetlb=@var{on|off},hugetlbsize=@var{size}
4252 Creates an anonymous memory file backend object, which allows QEMU to
4253 share the memory with an external process (e.g. when using
4254 vhost-user). The memory is allocated with memfd and optional
4255 sealing. (Linux only)
4257 The @option{seal} option creates a sealed-file, that will block
4258 further resizing the memory ('on
' by default).
4260 The @option{hugetlb} option specify the file to be created resides in
4261 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with
4262 the @option{hugetlb} option, the @option{hugetlbsize} option specify
4263 the hugetlb page size on systems that support multiple hugetlb page
4264 sizes (it must be a power of 2 value supported by the system).
4266 In some versions of Linux, the @option{hugetlb} option is incompatible
4267 with the @option{seal} option (requires at least Linux 4.16).
4269 Please refer to @option{memory-backend-file} for a description of the
4272 The @option{share} boolean option is @var{on} by default with memfd.
4274 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
4276 Creates a random number generator backend which obtains entropy from
4277 a device on the host. The @option{id} parameter is a unique ID that
4278 will be used to reference this entropy backend from the @option{virtio-rng}
4279 device. The @option{filename} parameter specifies which file to obtain
4280 entropy from and if omitted defaults to @option{/dev/random}.
4282 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4284 Creates a random number generator backend which obtains entropy from
4285 an external daemon running on the host. The @option{id} parameter is
4286 a unique ID that will be used to reference this entropy backend from
4287 the @option{virtio-rng} device. The @option{chardev} parameter is
4288 the unique ID of a character device backend that provides the connection
4291 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4293 Creates a TLS anonymous credentials object, which can be used to provide
4294 TLS support on network backends. The @option{id} parameter is a unique
4295 ID which network backends will use to access the credentials. The
4296 @option{endpoint} is either @option{server} or @option{client} depending
4297 on whether the QEMU network backend that uses the credentials will be
4298 acting as a client or as a server. If @option{verify-peer} is enabled
4299 (the default) then once the handshake is completed, the peer credentials
4300 will be verified, though this is a no-op for anonymous credentials.
4302 The @var{dir} parameter tells QEMU where to find the credential
4303 files. For server endpoints, this directory may contain a file
4304 @var{dh-params.pem} providing diffie-hellman parameters to use
4305 for the TLS server. If the file is missing, QEMU will generate
4306 a set of DH parameters at startup. This is a computationally
4307 expensive operation that consumes random pool entropy, so it is
4308 recommended that a persistent set of parameters be generated
4311 @item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}]
4313 Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide
4314 TLS support on network backends. The @option{id} parameter is a unique
4315 ID which network backends will use to access the credentials. The
4316 @option{endpoint} is either @option{server} or @option{client} depending
4317 on whether the QEMU network backend that uses the credentials will be
4318 acting as a client or as a server. For clients only, @option{username}
4319 is the username which will be sent to the server. If omitted
4320 it defaults to ``qemu''.
4322 The @var{dir} parameter tells QEMU where to find the keys file.
4323 It is called ``@var{dir}/keys.psk'' and contains ``username:key''
4324 pairs. This file can most easily be created using the GnuTLS
4325 @code{psktool} program.
4327 For server endpoints, @var{dir} may also contain a file
4328 @var{dh-params.pem} providing diffie-hellman parameters to use
4329 for the TLS server. If the file is missing, QEMU will generate
4330 a set of DH parameters at startup. This is a computationally
4331 expensive operation that consumes random pool entropy, so it is
4332 recommended that a persistent set of parameters be generated
4335 @item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},priority=@var{priority},verify-peer=@var{on|off},passwordid=@var{id}
4337 Creates a TLS anonymous credentials object, which can be used to provide
4338 TLS support on network backends. The @option{id} parameter is a unique
4339 ID which network backends will use to access the credentials. The
4340 @option{endpoint} is either @option{server} or @option{client} depending
4341 on whether the QEMU network backend that uses the credentials will be
4342 acting as a client or as a server. If @option{verify-peer} is enabled
4343 (the default) then once the handshake is completed, the peer credentials
4344 will be verified. With x509 certificates, this implies that the clients
4345 must be provided with valid client certificates too.
4347 The @var{dir} parameter tells QEMU where to find the credential
4348 files. For server endpoints, this directory may contain a file
4349 @var{dh-params.pem} providing diffie-hellman parameters to use
4350 for the TLS server. If the file is missing, QEMU will generate
4351 a set of DH parameters at startup. This is a computationally
4352 expensive operation that consumes random pool entropy, so it is
4353 recommended that a persistent set of parameters be generated
4356 For x509 certificate credentials the directory will contain further files
4357 providing the x509 certificates. The certificates must be stored
4358 in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4359 @var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4360 @var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4362 For the @var{server-key.pem} and @var{client-key.pem} files which
4363 contain sensitive private keys, it is possible to use an encrypted
4364 version by providing the @var{passwordid} parameter. This provides
4365 the ID of a previously created @code{secret} object containing the
4366 password for decryption.
4368 The @var{priority} parameter allows to override the global default
4369 priority used by gnutls. This can be useful if the system administrator
4370 needs to use a weaker set of crypto priorities for QEMU without
4371 potentially forcing the weakness onto all applications. Or conversely
4372 if one wants wants a stronger default for QEMU than for all other
4373 applications, they can do this through this parameter. Its format is
4374 a gnutls priority string as described at
4375 @url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4377 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4379 Interval @var{t} can't be
0, this filter batches the packet delivery
: all
4380 packets arriving
in a given interval on netdev @
var{netdevid
} are delayed
4381 until the end of the interval
. Interval is
in microseconds
.
4382 @option
{status
} is optional that indicate whether the netfilter is
4383 on (enabled
) or
off (disabled
), the
default status
for netfilter will be
'on'.
4385 queue @
var{all|rx|tx
} is an option that can be applied to any netfilter
.
4387 @option
{all
}: the filter is attached both to the receive and the transmit
4388 queue of the
netdev (default).
4390 @option
{rx
}: the filter is attached to the receive queue of the netdev
,
4391 where it will receive packets sent to the netdev
.
4393 @option
{tx
}: the filter is attached to the transmit queue of the netdev
,
4394 where it will receive packets sent by the netdev
.
4396 @item
-object filter
-mirror
,id
=@
var{id
},netdev
=@
var{netdevid
},outdev
=@
var{chardevid
},queue
=@
var{all|rx|tx
}[,vnet_hdr_support
]
4398 filter
-mirror on netdev @
var{netdevid
},mirror net packet to chardev@
var{chardevid
}, if it has the vnet_hdr_support flag
, filter
-mirror will mirror packet with vnet_hdr_len
.
4400 @item
-object filter
-redirector
,id
=@
var{id
},netdev
=@
var{netdevid
},indev
=@
var{chardevid
},outdev
=@
var{chardevid
},queue
=@
var{all|rx|tx
}[,vnet_hdr_support
]
4402 filter
-redirector on netdev @
var{netdevid
},redirect filter
's net packet to chardev
4403 @var{chardevid},and redirect indev's packet to filter
.if it has the vnet_hdr_support flag
,
4404 filter
-redirector will redirect packet with vnet_hdr_len
.
4405 Create a filter
-redirector we need to differ outdev id from indev id
, id can not
4406 be the same
. we can just use indev or outdev
, but at least one of indev or outdev
4407 need to be specified
.
4409 @item
-object filter
-rewriter
,id
=@
var{id
},netdev
=@
var{netdevid
},queue
=@
var{all|rx|tx
},[vnet_hdr_support
]
4411 Filter
-rewriter is a part of COLO project
.It will rewrite tcp packet to
4412 secondary from primary to keep secondary tcp connection
,and rewrite
4413 tcp packet to primary from secondary make tcp packet can be handled by
4414 client
.if it has the vnet_hdr_support flag
, we can parse packet with vnet header
.
4418 -object filter
-redirector
,id
=f1
,netdev
=hn0
,queue
=tx
,indev
=red0
4419 -object filter
-redirector
,id
=f2
,netdev
=hn0
,queue
=rx
,outdev
=red1
4420 -object filter
-rewriter
,id
=rew0
,netdev
=hn0
,queue
=all
4422 @item
-object filter
-dump
,id
=@
var{id
},netdev
=@
var{dev
}[,file
=@
var{filename
}][,maxlen
=@
var{len
}]
4424 Dump the network traffic on netdev @
var{dev
} to the file specified by
4425 @
var{filename
}. At most @
var{len
} bytes (64k by
default) per packet are stored
.
4426 The file format is libpcap
, so it can be analyzed with tools such as tcpdump
4429 @item
-object colo
-compare
,id
=@
var{id
},primary_in
=@
var{chardevid
},secondary_in
=@
var{chardevid
},outdev
=@
var{chardevid
},iothread
=@
var{id
}[,vnet_hdr_support
]
4431 Colo
-compare gets packet from primary_in@
var{chardevid
} and secondary_in@
var{chardevid
}, than compare primary packet with
4432 secondary packet
. If the packets are same
, we will output primary
4433 packet to outdev@
var{chardevid
}, else we will notify colo
-frame
4434 do checkpoint and send primary packet to outdev@
var{chardevid
}.
4435 In order to improve efficiency
, we need to put the task of comparison
4436 in another thread
. If it has the vnet_hdr_support flag
, colo compare
4437 will send
/recv packet with vnet_hdr_len
.
4439 we must use it with the help of filter
-mirror and filter
-redirector
.
4444 -netdev tap
,id
=hn0
,vhost
=off
,script
=/etc
/qemu
-ifup
,downscript
=/etc
/qemu
-ifdown
4445 -device e1000
,id
=e0
,netdev
=hn0
,mac
=52:a4
:00:12:78:66
4446 -chardev socket
,id
=mirror0
,host
=3.3.3.3,port
=9003,server
,nowait
4447 -chardev socket
,id
=compare1
,host
=3.3.3.3,port
=9004,server
,nowait
4448 -chardev socket
,id
=compare0
,host
=3.3.3.3,port
=9001,server
,nowait
4449 -chardev socket
,id
=compare0
-0,host
=3.3.3.3,port
=9001
4450 -chardev socket
,id
=compare_out
,host
=3.3.3.3,port
=9005,server
,nowait
4451 -chardev socket
,id
=compare_out0
,host
=3.3.3.3,port
=9005
4452 -object iothread
,id
=iothread1
4453 -object filter
-mirror
,id
=m0
,netdev
=hn0
,queue
=tx
,outdev
=mirror0
4454 -object filter
-redirector
,netdev
=hn0
,id
=redire0
,queue
=rx
,indev
=compare_out
4455 -object filter
-redirector
,netdev
=hn0
,id
=redire1
,queue
=rx
,outdev
=compare0
4456 -object colo
-compare
,id
=comp0
,primary_in
=compare0
-0,secondary_in
=compare1
,outdev
=compare_out0
,iothread
=iothread1
4459 -netdev tap
,id
=hn0
,vhost
=off
,script
=/etc
/qemu
-ifup
,down script
=/etc
/qemu
-ifdown
4460 -device e1000
,netdev
=hn0
,mac
=52:a4
:00:12:78:66
4461 -chardev socket
,id
=red0
,host
=3.3.3.3,port
=9003
4462 -chardev socket
,id
=red1
,host
=3.3.3.3,port
=9004
4463 -object filter
-redirector
,id
=f1
,netdev
=hn0
,queue
=tx
,indev
=red0
4464 -object filter
-redirector
,id
=f2
,netdev
=hn0
,queue
=rx
,outdev
=red1
4468 If you want to know the detail of above command line
, you can read
4469 the colo
-compare git log
.
4471 @item
-object cryptodev
-backend
-builtin
,id
=@
var{id
}[,queues
=@
var{queues
}]
4473 Creates a cryptodev backend which executes crypto opreation from
4474 the QEMU cipher APIS
. The @
var{id
} parameter is
4475 a unique ID that will be used to reference
this cryptodev backend from
4476 the @option
{virtio
-crypto
} device
. The @
var{queues
} parameter is optional
,
4477 which specify the queue number of cryptodev backend
, the
default of
4482 # qemu
-system
-x86_64 \
4484 -object cryptodev
-backend
-builtin
,id
=cryptodev0 \
4485 -device virtio
-crypto
-pci
,id
=crypto0
,cryptodev
=cryptodev0 \
4489 @item
-object cryptodev
-vhost
-user
,id
=@
var{id
},chardev
=@
var{chardevid
}[,queues
=@
var{queues
}]
4491 Creates a vhost
-user cryptodev backend
, backed by a chardev @
var{chardevid
}.
4492 The @
var{id
} parameter is a unique ID that will be used to reference
this
4493 cryptodev backend from the @option
{virtio
-crypto
} device
.
4494 The chardev should be a unix domain socket backed one
. The vhost
-user uses
4495 a specifically defined protocol to pass vhost ioctl replacement messages
4496 to an application on the other end of the socket
.
4497 The @
var{queues
} parameter is optional
, which specify the queue number
4498 of cryptodev backend
for multiqueue vhost
-user
, the
default of @
var{queues
} is
1.
4502 # qemu
-system
-x86_64 \
4504 -chardev socket
,id
=chardev0
,path
=/path
/to
/socket \
4505 -object cryptodev
-vhost
-user
,id
=cryptodev0
,chardev
=chardev0 \
4506 -device virtio
-crypto
-pci
,id
=crypto0
,cryptodev
=cryptodev0 \
4510 @item
-object secret
,id
=@
var{id
},data
=@
var{string
},format
=@
var{raw|base64
}[,keyid
=@
var{secretid
},iv
=@
var{string
}]
4511 @item
-object secret
,id
=@
var{id
},file
=@
var{filename
},format
=@
var{raw|base64
}[,keyid
=@
var{secretid
},iv
=@
var{string
}]
4513 Defines a secret to store a password
, encryption key
, or some other sensitive
4514 data
. The sensitive data can either be passed directly via the @
var{data
}
4515 parameter
, or indirectly via the @
var{file
} parameter
. Using the @
var{data
}
4516 parameter is insecure unless the sensitive data is encrypted
.
4518 The sensitive data can be provided
in raw
format (the
default), or base64
.
4519 When encoded as JSON
, the raw format only supports valid UTF
-8 characters
,
4520 so base64 is recommended
for sending binary data
. QEMU will convert from
4521 which ever format is provided to the format it needs internally
. eg
, an
4522 RBD password can be provided
in raw format
, even though it will be base64
4523 encoded when passed onto the RBD sever
.
4525 For added protection
, it is possible to encrypt the data associated with
4526 a secret
using the AES
-256-CBC cipher
. Use of encryption is indicated
4527 by providing the @
var{keyid
} and @
var{iv
} parameters
. The @
var{keyid
}
4528 parameter provides the ID of a previously defined secret that contains
4529 the AES
-256 decryption key
. This key should be
32-bytes long and be
4530 base64 encoded
. The @
var{iv
} parameter provides the random initialization
4531 vector used
for encryption of
this particular secret and should be a
4532 base64 encrypted string of the
16-byte IV
.
4534 The
simplest (insecure
) usage is to provide the secret
inline
4538 # $QEMU
-object secret
,id
=sec0
,data
=letmein
,format
=raw
4542 The simplest secure usage is to provide the secret via a file
4544 # printf
"letmein" > mypasswd
.txt
4545 # $QEMU
-object secret
,id
=sec0
,file
=mypasswd
.txt
,format
=raw
4547 For greater security
, AES
-256-CBC should be used
. To illustrate usage
,
4548 consider the openssl command line tool which can encrypt the data
. Note
4549 that when encrypting
, the plaintext must be padded to the cipher block
4550 size (32 bytes
) using the standard PKCS#
5/6 compatible padding algorithm
.
4552 First a master key needs to be created
in base64 encoding
:
4555 # openssl rand
-base64
32 > key
.b64
4556 # KEY
=$
(base64
-d key
.b64 | hexdump
-v
-e
'/1 "%02X"')
4559 Each secret to be encrypted needs to have a random initialization vector
4560 generated
. These
do not need to be kept secret
4563 # openssl rand
-base64
16 > iv
.b64
4564 # IV
=$
(base64
-d iv
.b64 | hexdump
-v
-e
'/1 "%02X"')
4567 The secret to be defined can now be encrypted
, in this case we
're
4568 telling openssl to base64 encode the result, but it could be left
4569 as raw bytes if desired.
4572 # SECRET=$(printf "letmein" |
4573 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4576 When launching QEMU, create a master secret pointing to @code{key.b64}
4577 and specify that to be used to decrypt the user password. Pass the
4578 contents of @code{iv.b64} to the second secret
4582 -object secret,id=secmaster0,format=base64,file=key.b64 \
4583 -object secret,id=sec0,keyid=secmaster0,format=base64,\
4584 data=$SECRET,iv=$(<iv.b64)
4587 @item -object sev-guest,id=@var{id},cbitpos=@var{cbitpos},reduced-phys-bits=@var{val},[sev-device=@var{string},policy=@var{policy},handle=@var{handle},dh-cert-file=@var{file},session-file=@var{file}]
4589 Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4590 to provide the guest memory encryption support on AMD processors.
4592 When memory encryption is enabled, one of the physical address bit (aka the
4593 C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4594 is used to provide the C-bit position. The C-bit position is Host family dependent
4595 hence user must provide this value. On EPYC, the value should be 47.
4597 When memory encryption is enabled, we loose certain bits in physical address space.
4598 The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4599 physical address space. Similar to C-bit, the value is Host family dependent.
4600 On EPYC, the value should be 5.
4602 The @option{sev-device} provides the device file to use for communicating with
4603 the SEV firmware running inside AMD Secure Processor. The default device is
4604 '/dev
/sev
'. If hardware supports memory encryption then /dev/sev devices are
4605 created by CCP driver.
4607 The @option{policy} provides the guest policy to be enforced by the SEV firmware
4608 and restrict what configuration and operational commands can be performed on this
4609 guest by the hypervisor. The policy should be provided by the guest owner and is
4610 bound to the guest and cannot be changed throughout the lifetime of the guest.
4613 If guest @option{policy} allows sharing the key with another SEV guest then
4614 @option{handle} can be use to provide handle of the guest from which to share
4617 The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4618 Public Diffie
-Hillman key defined
in SEV spec
. The PDH and session parameters
4619 are used
for establishing a cryptographic session with the guest owner to
4620 negotiate keys used
for attestation
. The file must be encoded
in base64
.
4622 e
.g to launch a SEV guest
4626 -object sev
-guest
,id
=sev0
,cbitpos
=47,reduced
-phys
-bits
=5 \
4627 -machine
...,memory
-encryption
=sev0
4633 @item
-object authz
-simple
,id
=@
var{id
},identity
=@
var{string
}
4635 Create an authorization object that will control access to network services
.
4637 The @option
{identity
} parameter is identifies the user and its format
4638 depends on the network service that authorization object is associated
4639 with
. For authorizing based on TLS x509 certificates
, the identity must
4640 be the x509 distinguished name
. Note that care must be taken to escape
4641 any commas
in the distinguished name
.
4643 An example authorization object to validate a x509 distinguished name
4648 -object
'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \
4652 Note the use of quotes due to the x509 distinguished name containing
4653 whitespace
, and escaping of
','.
4655 @item
-object authz
-listfile
,id
=@
var{id
},filename
=@
var{path
},refresh
=@
var{yes|no
}
4657 Create an authorization object that will control access to network services
.
4659 The @option
{filename
} parameter is the fully qualified path to a file
4660 containing the access control list rules
in JSON format
.
4662 An example set of rules that match against SASL usernames might look
4668 @
{ "match": "fred", "policy": "allow", "format": "exact" @
},
4669 @
{ "match": "bob", "policy": "allow", "format": "exact" @
},
4670 @
{ "match": "danb", "policy": "deny", "format": "glob" @
},
4671 @
{ "match": "dan*", "policy": "allow", "format": "exact" @
},
4677 When checking access the object will iterate over all the rules and
4678 the first rule to match will have its @option
{policy
} value returned
4679 as the result
. If no rules match
, then the
default @option
{policy
}
4682 The rules can either be an exact string match
, or they can use the
4683 simple UNIX glob pattern matching to allow wildcards to be used
.
4685 If @option
{refresh
} is set to
true the file will be monitored
4686 and automatically reloaded whenever its content changes
.
4688 As with the @code
{authz
-simple
} object
, the format of the identity
4689 strings being matched depends on the network service
, but is usually
4690 a TLS x509 distinguished name
, or a SASL username
.
4692 An example authorization object to validate a SASL username
4697 -object authz
-simple
,id
=auth0
,filename
=/etc
/qemu
/vnc
-sasl
.acl
,refresh
=yes
4701 @item
-object authz
-pam
,id
=@
var{id
},service
=@
var{string
}
4703 Create an authorization object that will control access to network services
.
4705 The @option
{service
} parameter provides the name of a PAM service to use
4706 for authorization
. It requires that a file @code
{/etc
/pam
.d
/@
var{service
}}
4707 exist to provide the configuration
for the @code
{account
} subsystem
.
4709 An example authorization object to validate a TLS x509 distinguished
4710 name would look like
:
4715 -object authz
-pam
,id
=auth0
,service
=qemu
-vnc
4719 There would then be a corresponding config file
for PAM at
4720 @code
{/etc
/pam
.d
/qemu
-vnc
} that contains
:
4723 account requisite pam_listfile
.so item
=user sense
=allow \
4724 file
=/etc
/qemu
/vnc
.allow
4727 Finally the @code
{/etc
/qemu
/vnc
.allow
} file would contain
4728 the list of x509 distingished names that are permitted
4732 CN
=laptop
.example
.com
,O
=Example Home
,L
=London
,ST
=London
,C
=GB
4741 HXCOMM This is the last statement
. Insert
new options before
this line
!