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, tcg (default: tcg)\n"
35 " kernel_irqchip=on|off controls accelerated irqchip support\n"
36 " kvm_shadow_mem=size of KVM shadow MMU\n"
37 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
38 " mem-merge=on|off controls memory merge support (default: on)\n",
41 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
43 Select the emulated machine by @
var{name
}. Use @code
{-machine help
} to list
44 available machines
. Supported machine properties are
:
46 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
47 This is used to enable an accelerator
. Depending on the target architecture
,
48 kvm
, xen
, or tcg can be available
. By
default, tcg is used
. If there is more
49 than one accelerator specified
, the next one is used
if the previous one fails
51 @item kernel_irqchip
=on|off
52 Enables
in-kernel irqchip support
for the chosen accelerator when available
.
53 @item kvm_shadow_mem
=size
54 Defines the size of the KVM shadow MMU
.
55 @item dump
-guest
-core
=on|off
56 Include guest memory
in a core dump
. The
default is on
.
57 @item mem
-merge
=on|off
58 Enables or disables memory merge support
. This feature
, when supported by
59 the host
, de
-duplicates identical memory pages among VMs instances
64 HXCOMM Deprecated by
-machine
65 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
67 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
68 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
70 @item
-cpu @
var{model
}
72 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
75 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
76 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
77 " set the number of CPUs to 'n' [default=1]\n"
78 " maxcpus= maximum number of total cpus, including\n"
79 " offline CPUs for hotplug, etc\n"
80 " cores= number of CPU cores on one socket\n"
81 " threads= number of threads on one CPU core\n"
82 " sockets= number of discrete sockets in the system\n",
85 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
87 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
88 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
90 For the PC target
, the number of @
var{cores
} per socket
, the number
91 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
92 specified
. Missing values will be computed
. If any on the three values is
93 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
94 specifies the maximum number of hotpluggable CPUs
.
97 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
98 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n"
99 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL
)
101 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
102 @item
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
104 Simulate a multi node NUMA system
. If @samp
{mem
}, @samp
{memdev
}
105 and @samp
{cpus
} are omitted
, resources are split equally
. Also
, note
106 that the
-@option
{numa
} option doesn
't allocate any of the specified
107 resources. That is, it just assigns existing resources to NUMA nodes. This
108 means that one still has to use the @option{-m}, @option{-smp} options
109 to allocate RAM and VCPUs respectively, and possibly @option{-object}
110 to specify the memory backend for the @samp{memdev} suboption.
112 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
113 node uses @samp{memdev}, all of them have to use it.
116 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
117 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
118 " Add 'fd
' to fd 'set
'\n", QEMU_ARCH_ALL)
120 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
123 Add a file descriptor to an fd set. Valid options are:
127 This option defines the file descriptor of which a duplicate is added to fd set.
128 The file descriptor cannot be stdin, stdout, or stderr.
130 This option defines the ID of the fd set to add the file descriptor to.
131 @item opaque=@var{opaque}
132 This option defines a free-form string that can be used to describe @var{fd}.
135 You can open an image using pre-opened file descriptors from an fd set:
138 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
139 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
140 -drive file=/dev/fdset/2,index=0,media=disk
144 DEF("set", HAS_ARG, QEMU_OPTION_set,
145 "-set group.id.arg=value\n"
146 " set <arg> parameter for item <id> of type <group>\n"
147 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
149 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
151 Set parameter @var{arg} for item @var{id} of type @var{group}\n"
154 DEF("global", HAS_ARG, QEMU_OPTION_global,
155 "-global driver.prop=value\n"
156 " set a global default for a driver property\n",
159 @item -global @var{driver}.@var{prop}=@var{value}
161 Set default value of @var{driver}'s property @
var{prop
} to @
var{value
}, e
.g
.:
164 qemu
-system
-i386
-global ide
-drive
.physical_block_size
=4096 -drive file
=file
,if=ide
,index
=0,media
=disk
167 In particular
, you can use
this to set driver properties
for devices which are
168 created automatically by the machine model
. To create a device which is not
169 created automatically and set properties on it
, use
-@option
{device
}.
172 DEF("boot", HAS_ARG
, QEMU_OPTION_boot
,
173 "-boot [order=drives][,once=drives][,menu=on|off]\n"
174 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
175 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
176 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
177 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
178 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
181 @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
]
183 Specify boot order @
var{drives
} as a string of drive letters
. Valid
184 drive letters depend on the target achitecture
. The x86 PC uses
: a
, b
185 (floppy
1 and
2), c (first hard disk
), d (first CD
-ROM
), n
-p (Etherboot
186 from network adapter
1-4), hard disk boot is the
default. To apply a
187 particular boot order only on the first startup
, specify it via
190 Interactive boot menus
/prompts can be enabled via @option
{menu
=on
} as far
191 as firmware
/BIOS supports them
. The
default is non
-interactive boot
.
193 A splash picture could be passed to bios
, enabling user to show it as logo
,
194 when option splash
=@
var{sp_name
} is given and menu
=on
, If firmware
/BIOS
195 supports them
. Currently Seabios
for X86 system support it
.
196 limitation
: The splash file could be a jpeg file or a BMP file
in 24 BPP
197 format(true color
). The resolution should be supported by the SVGA mode
, so
198 the recommended is
320x240
, 640x480
, 800x640
.
200 A timeout could be passed to bios
, guest will pause
for @
var{rb_timeout
} ms
201 when boot failed
, then reboot
. If @
var{rb_timeout
} is
'-1', guest will not
202 reboot
, qemu passes
'-1' to bios by
default. Currently Seabios
for X86
205 Do strict boot via @option
{strict
=on
} as far as firmware
/BIOS
206 supports it
. This only effects when boot priority is changed by
207 bootindex options
. The
default is non
-strict boot
.
210 #
try to boot from network first
, then from hard disk
211 qemu
-system
-i386
-boot order
=nc
212 # boot from CD
-ROM first
, switch back to
default order after reboot
213 qemu
-system
-i386
-boot once
=d
214 # boot with a splash picture
for 5 seconds
.
215 qemu
-system
-i386
-boot menu
=on
,splash
=/root
/boot
.bmp
,splash
-time
=5000
218 Note
: The legacy format
'-boot @var{drives}' is still supported but its
219 use is discouraged as it may be removed from future versions
.
222 DEF("m", HAS_ARG
, QEMU_OPTION_m
,
223 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
224 " configure guest RAM\n"
225 " size: initial amount of guest memory (default: "
226 stringify(DEFAULT_RAM_SIZE
) "MiB)\n"
227 " slots: number of hotplug slots (default: none)\n"
228 " maxmem: maximum amount of guest memory (default: none)\n",
231 @item
-m
[size
=]@
var{megs
}
233 Set virtual RAM size to @
var{megs
} megabytes
. Default is
128 MiB
. Optionally
,
234 a suffix of ``M
'' or ``G
'' can be used to signify a value
in megabytes or
235 gigabytes respectively
. Optional pair @
var{slots
}, @
var{maxmem
} could be used
236 to set amount of hotluggable memory slots and possible maximum amount of memory
.
239 DEF("mem-path", HAS_ARG
, QEMU_OPTION_mempath
,
240 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL
)
242 @item
-mem
-path @
var{path
}
244 Allocate guest RAM from a temporarily created file
in @
var{path
}.
247 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc
,
248 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
252 @findex
-mem
-prealloc
253 Preallocate memory when
using -mem
-path
.
256 DEF("k", HAS_ARG
, QEMU_OPTION_k
,
257 "-k language use keyboard layout (for example 'fr' for French)\n",
260 @item
-k @
var{language
}
262 Use keyboard layout @
var{language
} (for example @code
{fr
} for
263 French
). This option is only needed where it is not easy to get raw PC
264 keycodes (e
.g
. on Macs
, with some X11 servers or with a VNC
265 display
). You don
't normally need to use it on PC/Linux or PC/Windows
268 The available layouts are:
270 ar de-ch es fo fr-ca hu ja mk no pt-br sv
271 da en-gb et fr fr-ch is lt nl pl ru th
272 de en-us fi fr-be hr it lv nl-be pt sl tr
275 The default is @code{en-us}.
279 DEF("audio-help", 0, QEMU_OPTION_audio_help,
280 "-audio-help print list of audio drivers and their options\n",
285 Will show the audio subsystem help: list of drivers, tunable
289 DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
290 "-soundhw c1,... enable audio support\n"
291 " and only specified sound cards (comma separated list)\n"
292 " use '-soundhw help
' to get the list of supported cards\n"
293 " use '-soundhw all
' to enable all of them\n", QEMU_ARCH_ALL)
295 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
297 Enable audio and selected sound hardware. Use 'help
' to print all
298 available sound hardware.
301 qemu-system-i386 -soundhw sb16,adlib disk.img
302 qemu-system-i386 -soundhw es1370 disk.img
303 qemu-system-i386 -soundhw ac97 disk.img
304 qemu-system-i386 -soundhw hda disk.img
305 qemu-system-i386 -soundhw all disk.img
306 qemu-system-i386 -soundhw help
309 Note that Linux's i810_audio OSS
kernel (for AC97
) module might
310 require manually specifying clocking
.
313 modprobe i810_audio clocking
=48000
317 DEF("balloon", HAS_ARG
, QEMU_OPTION_balloon
,
318 "-balloon none disable balloon device\n"
319 "-balloon virtio[,addr=str]\n"
320 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL
)
324 Disable balloon device
.
325 @item
-balloon virtio
[,addr
=@
var{addr
}]
326 Enable virtio balloon
device (default), optionally with PCI address
330 DEF("device", HAS_ARG
, QEMU_OPTION_device
,
331 "-device driver[,prop[=value][,...]]\n"
332 " add device (based on driver)\n"
333 " prop=value,... sets driver properties\n"
334 " use '-device help' to print all possible drivers\n"
335 " use '-device driver,help' to print all possible properties\n",
338 @item
-device @
var{driver
}[,@
var{prop
}[=@
var{value
}][,...]]
340 Add device @
var{driver
}. @
var{prop
}=@
var{value
} sets driver
341 properties
. Valid properties depend on the driver
. To get help on
342 possible drivers and properties
, use @code
{-device help
} and
343 @code
{-device @
var{driver
},help
}.
346 DEF("name", HAS_ARG
, QEMU_OPTION_name
,
347 "-name string1[,process=string2][,debug-threads=on|off]\n"
348 " set the name of the guest\n"
349 " string1 sets the window title and string2 the process name (on Linux)\n"
350 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
351 " NOTE: The thread names are for debugging and not a stable API.\n",
354 @item
-name @
var{name
}
356 Sets the @
var{name
} of the guest
.
357 This name will be displayed
in the SDL window caption
.
358 The @
var{name
} will also be used
for the VNC server
.
359 Also optionally set the top visible process name
in Linux
.
360 Naming of individual threads can also be enabled on Linux to aid debugging
.
363 DEF("uuid", HAS_ARG
, QEMU_OPTION_uuid
,
364 "-uuid %08x-%04x-%04x-%04x-%012x\n"
365 " specify machine UUID\n", QEMU_ARCH_ALL
)
367 @item
-uuid @
var{uuid
}
377 DEFHEADING(Block device options
:)
382 DEF("fda", HAS_ARG
, QEMU_OPTION_fda
,
383 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL
)
384 DEF("fdb", HAS_ARG
, QEMU_OPTION_fdb
, "", QEMU_ARCH_ALL
)
386 @item
-fda @
var{file
}
387 @item
-fdb @
var{file
}
390 Use @
var{file
} as floppy disk
0/1 image (@pxref
{disk_images
}). You can
391 use the host floppy by
using @file
{/dev
/fd0
} as
filename (@pxref
{host_drives
}).
394 DEF("hda", HAS_ARG
, QEMU_OPTION_hda
,
395 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL
)
396 DEF("hdb", HAS_ARG
, QEMU_OPTION_hdb
, "", QEMU_ARCH_ALL
)
397 DEF("hdc", HAS_ARG
, QEMU_OPTION_hdc
,
398 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL
)
399 DEF("hdd", HAS_ARG
, QEMU_OPTION_hdd
, "", QEMU_ARCH_ALL
)
401 @item
-hda @
var{file
}
402 @item
-hdb @
var{file
}
403 @item
-hdc @
var{file
}
404 @item
-hdd @
var{file
}
409 Use @
var{file
} as hard disk
0, 1, 2 or
3 image (@pxref
{disk_images
}).
412 DEF("cdrom", HAS_ARG
, QEMU_OPTION_cdrom
,
413 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
416 @item
-cdrom @
var{file
}
418 Use @
var{file
} as CD
-ROM
image (you cannot use @option
{-hdc
} and
419 @option
{-cdrom
} at the same time
). You can use the host CD
-ROM by
420 using @file
{/dev
/cdrom
} as
filename (@pxref
{host_drives
}).
423 DEF("drive", HAS_ARG
, QEMU_OPTION_drive
,
424 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
425 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
426 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
427 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
428 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
429 " [,readonly=on|off][,copy-on-read=on|off]\n"
430 " [,detect-zeroes=on|off|unmap]\n"
431 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
432 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
433 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
434 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
435 " [[,iops_size=is]]\n"
436 " use 'file' as a drive image\n", QEMU_ARCH_ALL
)
438 @item
-drive @
var{option
}[,@
var{option
}[,@
var{option
}[,...]]]
441 Define a
new drive
. Valid options are
:
444 @item file
=@
var{file
}
445 This option defines which disk
image (@pxref
{disk_images
}) to use with
446 this drive
. If the filename contains comma
, you must double it
447 (for instance
, "file=my,,file" to use file
"my,file").
449 Special files such as iSCSI devices can be specified
using protocol
450 specific URLs
. See the section
for "Device URL Syntax" for more information
.
451 @item
if=@
var{interface}
452 This option defines on which type on
interface the drive is connected
.
453 Available types are
: ide
, scsi
, sd
, mtd
, floppy
, pflash
, virtio
.
454 @item bus
=@
var{bus
},unit
=@
var{unit
}
455 These options define where is connected the drive by defining the bus number and
457 @item index
=@
var{index
}
458 This option defines where is connected the drive by
using an index
in the list
459 of available connectors of a given
interface type
.
460 @item media
=@
var{media
}
461 This option defines the type of the media
: disk or cdrom
.
462 @item cyls
=@
var{c
},heads
=@
var{h
},secs
=@
var{s
}[,trans
=@
var{t
}]
463 These options have the same definition as they have
in @option
{-hdachs
}.
464 @item snapshot
=@
var{snapshot
}
465 @
var{snapshot
} is
"on" or
"off" and controls snapshot mode
for the given drive
466 (see @option
{-snapshot
}).
467 @item cache
=@
var{cache
}
468 @
var{cache
} is
"none", "writeback", "unsafe", "directsync" or
"writethrough" and controls how the host cache is used to access block data
.
470 @
var{aio
} is
"threads", or
"native" and selects between pthread based disk I
/O and native Linux AIO
.
471 @item discard
=@
var{discard
}
472 @
var{discard
} is one of
"ignore" (or
"off") or
"unmap" (or
"on") and controls whether @dfn
{discard
} (also known as @dfn
{trim
} or @dfn
{unmap
}) requests are ignored or passed to the filesystem
. Some machine types may not support discard requests
.
473 @item format
=@
var{format
}
474 Specify which disk @
var{format
} will be used rather than detecting
475 the format
. Can be used to specifiy format
=raw to avoid interpreting
476 an untrusted format header
.
477 @item serial
=@
var{serial
}
478 This option specifies the serial number to assign to the device
.
479 @item addr
=@
var{addr
}
480 Specify the controller
's PCI address (if=virtio only).
481 @item werror=@var{action},rerror=@var{action}
482 Specify which @var{action} to take on write and read errors. Valid actions are:
483 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
484 "report" (report the error to the guest), "enospc" (pause QEMU only if the
485 host disk is full; report the error to the guest otherwise).
486 The default setting is @option{werror=enospc} and @option{rerror=report}.
488 Open drive @option{file} as read-only. Guest write attempts will fail.
489 @item copy-on-read=@var{copy-on-read}
490 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
491 file sectors into the image file.
492 @item detect-zeroes=@var{detect-zeroes}
493 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
494 conversion of plain zero writes by the OS to driver specific optimized
495 zero write commands. You may even choose "unmap" if @var{discard} is set
496 to "unmap" to allow a zero write to be converted to an UNMAP operation.
499 By default, the @option{cache=writeback} mode is used. It will report data
500 writes as completed as soon as the data is present in the host page cache.
501 This is safe as long as your guest OS makes sure to correctly flush disk caches
502 where needed. If your guest OS does not handle volatile disk write caches
503 correctly and your host crashes or loses power, then the guest may experience
506 For such guests, you should consider using @option{cache=writethrough}. This
507 means that the host page cache will be used to read and write data, but write
508 notification will be sent to the guest only after QEMU has made sure to flush
509 each write to the disk. Be aware that this has a major impact on performance.
511 The host page cache can be avoided entirely with @option{cache=none}. This will
512 attempt to do disk IO directly to the guest's memory
. QEMU may still perform
513 an internal copy of the data
. Note that
this is considered a writeback mode and
514 the guest OS must handle the disk write cache correctly
in order to avoid data
515 corruption on host crashes
.
517 The host page cache can be avoided
while only sending write notifications to
518 the guest when the data has been flushed to the disk
using
519 @option
{cache
=directsync
}.
521 In
case you don
't care about data integrity over host failures, use
522 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
523 data to the disk but can instead keep things in cache. If anything goes wrong,
524 like your host losing power, the disk storage getting disconnected accidentally,
525 etc. your image will most probably be rendered unusable. When using
526 the @option{-snapshot} option, unsafe caching is always used.
528 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
529 useful when the backing file is over a slow network. By default copy-on-read
532 Instead of @option{-cdrom} you can use:
534 qemu-system-i386 -drive file=file,index=2,media=cdrom
537 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
540 qemu-system-i386 -drive file=file,index=0,media=disk
541 qemu-system-i386 -drive file=file,index=1,media=disk
542 qemu-system-i386 -drive file=file,index=2,media=disk
543 qemu-system-i386 -drive file=file,index=3,media=disk
546 You can open an image using pre-opened file descriptors from an fd set:
549 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
550 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
551 -drive file=/dev/fdset/2,index=0,media=disk
554 You can connect a CDROM to the slave of ide0:
556 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
559 If you don't specify the
"file=" argument
, you define an empty drive
:
561 qemu
-system
-i386
-drive
if=ide
,index
=1,media
=cdrom
564 You can connect a SCSI disk with unit ID
6 on the bus #
0:
566 qemu
-system
-i386
-drive file
=file
,if=scsi
,bus
=0,unit
=6
569 Instead of @option
{-fda
}, @option
{-fdb
}, you can use
:
571 qemu
-system
-i386
-drive file
=file
,index
=0,if=floppy
572 qemu
-system
-i386
-drive file
=file
,index
=1,if=floppy
575 By
default, @
var{interface} is
"ide" and @
var{index
} is automatically
578 qemu
-system
-i386
-drive file
=a
-drive file
=b
"
582 qemu-system-i386 -hda a -hdb b
586 DEF("mtdblock
", HAS_ARG, QEMU_OPTION_mtdblock,
587 "-mtdblock file use
'file' as on
-board Flash memory image
\n",
590 @item -mtdblock @var{file}
592 Use @var{file} as on-board Flash memory image.
595 DEF("sd
", HAS_ARG, QEMU_OPTION_sd,
596 "-sd file use
'file' as SecureDigital card image
\n", QEMU_ARCH_ALL)
600 Use @var{file} as SecureDigital card image.
603 DEF("pflash
", HAS_ARG, QEMU_OPTION_pflash,
604 "-pflash file use
'file' as a parallel flash image
\n", QEMU_ARCH_ALL)
606 @item -pflash @var{file}
608 Use @var{file} as a parallel flash image.
611 DEF("snapshot
", 0, QEMU_OPTION_snapshot,
612 "-snapshot write to temporary files instead of disk image files
\n",
617 Write to temporary files instead of disk image files. In this case,
618 the raw disk image you use is not written back. You can however force
619 the write back by pressing @key{C-a s} (@pxref{disk_images}).
622 DEF("hdachs
", HAS_ARG, QEMU_OPTION_hdachs, \
623 "-hdachs c
,h
,s
[,t
]\n" \
624 " force hard disk
0 physical geometry and the optional BIOS
\n" \
625 " translation (t
=none or lba
) (usually QEMU can guess them
)\n",
628 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
630 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
631 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
632 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
633 all those parameters. This option is useful for old MS-DOS disk
637 DEF("fsdev
", HAS_ARG, QEMU_OPTION_fsdev,
638 "-fsdev fsdriver
,id
=id
[,path
=path
,][security_model
={mapped
-xattr|mapped
-file|passthrough|none
}]\n"
639 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
644 @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}]
646 Define a new file system device. Valid options are:
649 This option specifies the fs driver backend to use.
650 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
652 Specifies identifier for this device
653 @item path=@var{path}
654 Specifies the export path for the file system device. Files under
655 this path will be available to the 9p client on the guest.
656 @item security_model=@var{security_model}
657 Specifies the security model to be used for this export path.
658 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
659 In "passthrough
" security model, files are stored using the same
660 credentials as they are created on the guest. This requires QEMU
661 to run as root. In "mapped
-xattr
" security model, some of the file
662 attributes like uid, gid, mode bits and link target are stored as
663 file attributes. For "mapped
-file
" these attributes are stored in the
664 hidden .virtfs_metadata directory. Directories exported by this security model cannot
665 interact with other unix tools. "none
" security model is same as
666 passthrough except the sever won't report failures if it fails to
667 set file attributes like ownership. Security model is mandatory
668 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
669 security model as a parameter.
670 @item writeout=@var{writeout}
671 This is an optional argument. The only supported value is "immediate
".
672 This means that host page cache will be used to read and write data but
673 write notification will be sent to the guest only when the data has been
674 reported as written by the storage subsystem.
676 Enables exporting 9p share as a readonly mount for guests. By default
677 read-write access is given.
678 @item socket=@var{socket}
679 Enables proxy filesystem driver to use passed socket file for communicating
680 with virtfs-proxy-helper
681 @item sock_fd=@var{sock_fd}
682 Enables proxy filesystem driver to use passed socket descriptor for
683 communicating with virtfs-proxy-helper. Usually a helper like libvirt
684 will create socketpair and pass one of the fds as sock_fd
687 -fsdev option is used along with -device driver "virtio
-9p
-pci
".
688 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
689 Options for virtio-9p-pci driver are:
692 Specifies the id value specified along with -fsdev option
693 @item mount_tag=@var{mount_tag}
694 Specifies the tag name to be used by the guest to mount this export point
699 DEF("virtfs
", HAS_ARG, QEMU_OPTION_virtfs,
700 "-virtfs local
,path
=path
,mount_tag
=tag
,security_model
=[mapped
-xattr|mapped
-file|passthrough|none
]\n"
701 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
706 @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}]
709 The general form of a Virtual File system pass-through options are:
712 This option specifies the fs driver backend to use.
713 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
715 Specifies identifier for this device
716 @item path=@var{path}
717 Specifies the export path for the file system device. Files under
718 this path will be available to the 9p client on the guest.
719 @item security_model=@var{security_model}
720 Specifies the security model to be used for this export path.
721 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
722 In "passthrough
" security model, files are stored using the same
723 credentials as they are created on the guest. This requires QEMU
724 to run as root. In "mapped
-xattr
" security model, some of the file
725 attributes like uid, gid, mode bits and link target are stored as
726 file attributes. For "mapped
-file
" these attributes are stored in the
727 hidden .virtfs_metadata directory. Directories exported by this security model cannot
728 interact with other unix tools. "none
" security model is same as
729 passthrough except the sever won't report failures if it fails to
730 set file attributes like ownership. Security model is mandatory only
731 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
732 model as a parameter.
733 @item writeout=@var{writeout}
734 This is an optional argument. The only supported value is "immediate
".
735 This means that host page cache will be used to read and write data but
736 write notification will be sent to the guest only when the data has been
737 reported as written by the storage subsystem.
739 Enables exporting 9p share as a readonly mount for guests. By default
740 read-write access is given.
741 @item socket=@var{socket}
742 Enables proxy filesystem driver to use passed socket file for
743 communicating with virtfs-proxy-helper. Usually a helper like libvirt
744 will create socketpair and pass one of the fds as sock_fd
746 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
747 descriptor for interfacing with virtfs-proxy-helper
751 DEF("virtfs_synth
", 0, QEMU_OPTION_virtfs_synth,
752 "-virtfs_synth Create synthetic file system image
\n",
756 @findex -virtfs_synth
757 Create synthetic file system image
765 DEFHEADING(USB options:)
770 DEF("usb
", 0, QEMU_OPTION_usb,
771 "-usb enable the USB
driver (will be the
default soon
)\n",
776 Enable the USB driver (will be the default soon)
779 DEF("usbdevice
", HAS_ARG, QEMU_OPTION_usbdevice,
780 "-usbdevice name add the host or guest USB device
'name'\n",
784 @item -usbdevice @var{devname}
786 Add the USB device @var{devname}. @xref{usb_devices}.
791 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
794 Pointer device that uses absolute coordinates (like a touchscreen). This
795 means QEMU is able to report the mouse position without having to grab the
796 mouse. Also overrides the PS/2 mouse emulation when activated.
798 @item disk:[format=@var{format}]:@var{file}
799 Mass storage device based on file. The optional @var{format} argument
800 will be used rather than detecting the format. Can be used to specifiy
801 @code{format=raw} to avoid interpreting an untrusted format header.
803 @item host:@var{bus}.@var{addr}
804 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
806 @item host:@var{vendor_id}:@var{product_id}
807 Pass through the host device identified by @var{vendor_id}:@var{product_id}
810 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
811 Serial converter to host character device @var{dev}, see @code{-serial} for the
815 Braille device. This will use BrlAPI to display the braille output on a real
818 @item net:@var{options}
819 Network adapter that supports CDC ethernet and RNDIS protocols.
829 DEFHEADING(Display options:)
834 DEF("display
", HAS_ARG, QEMU_OPTION_display,
835 "-display sdl
[,frame
=on|off
][,alt_grab
=on|off
][,ctrl_grab
=on|off
]\n"
836 " [,window_close
=on|off
]|curses|none|
\n"
837 " gtk
[,grab_on_hover
=on|off
]|
\n"
838 " vnc
=<display
>[,<optargs
>]\n"
839 " select display type
\n", QEMU_ARCH_ALL)
841 @item -display @var{type}
843 Select type of display to use. This option is a replacement for the
844 old style -sdl/-curses/... options. Valid values for @var{type} are
847 Display video output via SDL (usually in a separate graphics
848 window; see the SDL documentation for other possibilities).
850 Display video output via curses. For graphics device models which
851 support a text mode, QEMU can display this output using a
852 curses/ncurses interface. Nothing is displayed when the graphics
853 device is in graphical mode or if the graphics device does not support
854 a text mode. Generally only the VGA device models support text mode.
856 Do not display video output. The guest will still see an emulated
857 graphics card, but its output will not be displayed to the QEMU
858 user. This option differs from the -nographic option in that it
859 only affects what is done with video output; -nographic also changes
860 the destination of the serial and parallel port data.
862 Display video output in a GTK window. This interface provides drop-down
863 menus and other UI elements to configure and control the VM during
866 Start a VNC server on display <arg>
870 DEF("nographic
", 0, QEMU_OPTION_nographic,
871 "-nographic disable graphical output and redirect serial I
/Os to console
\n",
876 Normally, QEMU uses SDL to display the VGA output. With this option,
877 you can totally disable graphical output so that QEMU is a simple
878 command line application. The emulated serial port is redirected on
879 the console and muxed with the monitor (unless redirected elsewhere
880 explicitly). Therefore, you can still use QEMU to debug a Linux kernel
881 with a serial console. Use @key{C-a h} for help on switching between
882 the console and monitor.
885 DEF("curses
", 0, QEMU_OPTION_curses,
886 "-curses use a curses
/ncurses
interface instead of SDL
\n",
891 Normally, QEMU uses SDL to display the VGA output. With this option,
892 QEMU can display the VGA output when in text mode using a
893 curses/ncurses interface. Nothing is displayed in graphical mode.
896 DEF("no
-frame
", 0, QEMU_OPTION_no_frame,
897 "-no
-frame open SDL window without a frame and window decorations
\n",
902 Do not use decorations for SDL windows and start them using the whole
903 available screen space. This makes the using QEMU in a dedicated desktop
904 workspace more convenient.
907 DEF("alt
-grab
", 0, QEMU_OPTION_alt_grab,
908 "-alt
-grab use Ctrl
-Alt
-Shift to grab
mouse (instead of Ctrl
-Alt
)\n",
913 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
914 affects the special keys (for fullscreen, monitor-mode switching, etc).
917 DEF("ctrl
-grab
", 0, QEMU_OPTION_ctrl_grab,
918 "-ctrl
-grab use Right
-Ctrl to grab
mouse (instead of Ctrl
-Alt
)\n",
923 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
924 affects the special keys (for fullscreen, monitor-mode switching, etc).
927 DEF("no
-quit
", 0, QEMU_OPTION_no_quit,
928 "-no
-quit disable SDL window close capability
\n", QEMU_ARCH_ALL)
932 Disable SDL window close capability.
935 DEF("sdl
", 0, QEMU_OPTION_sdl,
936 "-sdl enable SDL
\n", QEMU_ARCH_ALL)
943 DEF("spice
", HAS_ARG, QEMU_OPTION_spice,
944 "-spice
[port
=port
][,tls
-port
=secured
-port
][,x509
-dir
=<dir
>]\n"
945 " [,x509
-key
-file
=<file
>][,x509
-key
-password
=<file
>]\n"
946 " [,x509
-cert
-file
=<file
>][,x509
-cacert
-file
=<file
>]\n"
947 " [,x509
-dh
-key
-file
=<file
>][,addr
=addr
][,ipv4|ipv6
]\n"
948 " [,tls
-ciphers
=<list
>]\n"
949 " [,tls
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
950 " [,plaintext
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
951 " [,sasl
][,password
=<secret
>][,disable
-ticketing
]\n"
952 " [,image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]]\n"
953 " [,jpeg
-wan
-compression
=[auto|
never|always
]]\n"
954 " [,zlib
-glz
-wan
-compression
=[auto|
never|always
]]\n"
955 " [,streaming
-video
=[off|all|filter
]][,disable
-copy
-paste
]\n"
956 " [,disable
-agent
-file
-xfer
][,agent
-mouse
=[on|off
]]\n"
957 " [,playback
-compression
=[on|off
]][,seamless
-migration
=[on|off
]]\n"
959 " at least one of
{port
, tls
-port
} is mandatory
\n",
962 @item -spice @var{option}[,@var{option}[,...]]
964 Enable the spice remote desktop protocol. Valid options are
969 Set the TCP port spice is listening on for plaintext channels.
972 Set the IP address spice is listening on. Default is any address.
976 Force using the specified IP version.
978 @item password=<secret>
979 Set the password you need to authenticate.
982 Require that the client use SASL to authenticate with the spice.
983 The exact choice of authentication method used is controlled from the
984 system / user's SASL configuration file for the 'qemu' service. This
985 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
986 unprivileged user, an environment variable SASL_CONF_PATH can be used
987 to make it search alternate locations for the service config.
988 While some SASL auth methods can also provide data encryption (eg GSSAPI),
989 it is recommended that SASL always be combined with the 'tls' and
990 'x509' settings to enable use of SSL and server certificates. This
991 ensures a data encryption preventing compromise of authentication
994 @item disable-ticketing
995 Allow client connects without authentication.
997 @item disable-copy-paste
998 Disable copy paste between the client and the guest.
1000 @item disable-agent-file-xfer
1001 Disable spice-vdagent based file-xfer between the client and the guest.
1004 Set the TCP port spice is listening on for encrypted channels.
1006 @item x509-dir=<dir>
1007 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1009 @item x509-key-file=<file>
1010 @item x509-key-password=<file>
1011 @item x509-cert-file=<file>
1012 @item x509-cacert-file=<file>
1013 @item x509-dh-key-file=<file>
1014 The x509 file names can also be configured individually.
1016 @item tls-ciphers=<list>
1017 Specify which ciphers to use.
1019 @item tls-channel=[main|display|cursor|inputs|record|playback]
1020 @item plaintext-channel=[main|display|cursor|inputs|record|playback]
1021 Force specific channel to be used with or without TLS encryption. The
1022 options can be specified multiple times to configure multiple
1023 channels. The special name "default" can be used to set the default
1024 mode. For channels which are not explicitly forced into one mode the
1025 spice client is allowed to pick tls/plaintext as he pleases.
1027 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1028 Configure image compression (lossless).
1029 Default is auto_glz.
1031 @item jpeg-wan-compression=[auto|never|always]
1032 @item zlib-glz-wan-compression=[auto|never|always]
1033 Configure wan image compression (lossy for slow links).
1036 @item streaming-video=[off|all|filter]
1037 Configure video stream detection. Default is filter.
1039 @item agent-mouse=[on|off]
1040 Enable/disable passing mouse events via vdagent. Default is on.
1042 @item playback-compression=[on|off]
1043 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1045 @item seamless-migration=[on|off]
1046 Enable/disable spice seamless migration. Default is off.
1051 DEF("portrait
", 0, QEMU_OPTION_portrait,
1052 "-portrait rotate graphical output
90 deg
left (only PXA LCD
)\n",
1057 Rotate graphical output 90 deg left (only PXA LCD).
1060 DEF("rotate
", HAS_ARG, QEMU_OPTION_rotate,
1061 "-rotate
<deg
> rotate graphical output some deg
left (only PXA LCD
)\n",
1064 @item -rotate @var{deg}
1066 Rotate graphical output some deg left (only PXA LCD).
1069 DEF("vga
", HAS_ARG, QEMU_OPTION_vga,
1070 "-vga
[std|cirrus|vmware|qxl|xenfb|tcx|cg3|none
]\n"
1071 " select video card type
\n", QEMU_ARCH_ALL)
1073 @item -vga @var{type}
1075 Select type of VGA card to emulate. Valid values for @var{type} are
1078 Cirrus Logic GD5446 Video card. All Windows versions starting from
1079 Windows 95 should recognize and use this graphic card. For optimal
1080 performances, use 16 bit color depth in the guest and the host OS.
1081 (This one is the default)
1083 Standard VGA card with Bochs VBE extensions. If your guest OS
1084 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1085 to use high resolution modes (>= 1280x1024x16) then you should use
1088 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1089 recent XFree86/XOrg server or Windows guest with a driver for this
1092 QXL paravirtual graphic card. It is VGA compatible (including VESA
1093 2.0 VBE support). Works best with qxl guest drivers installed though.
1094 Recommended choice when using the spice protocol.
1096 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1097 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1098 fixed resolution of 1024x768.
1100 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1101 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1102 resolutions aimed at people wishing to run older Solaris versions.
1108 DEF("full
-screen
", 0, QEMU_OPTION_full_screen,
1109 "-full
-screen start
in full screen
\n", QEMU_ARCH_ALL)
1112 @findex -full-screen
1113 Start in full screen.
1116 DEF("g
", 1, QEMU_OPTION_g ,
1117 "-g WxH
[xDEPTH
] Set the initial graphical resolution and depth
\n",
1118 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1120 @item -g @var{width}x@var{height}[x@var{depth}]
1122 Set the initial graphical resolution and depth (PPC, SPARC only).
1125 DEF("vnc
", HAS_ARG, QEMU_OPTION_vnc ,
1126 "-vnc display start a VNC server on display
\n", QEMU_ARCH_ALL)
1128 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1130 Normally, QEMU uses SDL to display the VGA output. With this option,
1131 you can have QEMU listen on VNC display @var{display} and redirect the VGA
1132 display over the VNC session. It is very useful to enable the usb
1133 tablet device when using this option (option @option{-usbdevice
1134 tablet}). When using the VNC display, you must use the @option{-k}
1135 parameter to set the keyboard layout if you are not using en-us. Valid
1136 syntax for the @var{display} is
1140 @item @var{host}:@var{d}
1142 TCP connections will only be allowed from @var{host} on display @var{d}.
1143 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1144 be omitted in which case the server will accept connections from any host.
1146 @item unix:@var{path}
1148 Connections will be allowed over UNIX domain sockets where @var{path} is the
1149 location of a unix socket to listen for connections on.
1153 VNC is initialized but not started. The monitor @code{change} command
1154 can be used to later start the VNC server.
1158 Following the @var{display} value there may be one or more @var{option} flags
1159 separated by commas. Valid options are
1165 Connect to a listening VNC client via a ``reverse'' connection. The
1166 client is specified by the @var{display}. For reverse network
1167 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1168 is a TCP port number, not a display number.
1172 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1173 By definition the Websocket port is 5700+@var{display}. If @var{host} is
1174 specified connections will only be allowed from this host.
1175 As an alternative the Websocket port could be specified by using
1176 @code{websocket}=@var{port}.
1177 TLS encryption for the Websocket connection is supported if the required
1178 certificates are specified with the VNC option @option{x509}.
1182 Require that password based authentication is used for client connections.
1184 The password must be set separately using the @code{set_password} command in
1185 the @ref{pcsys_monitor}. The syntax to change your password is:
1186 @code{set_password <protocol> <password>} where <protocol> could be either
1189 If you would like to change <protocol> password expiration, you should use
1190 @code{expire_password <protocol> <expiration-time>} where expiration time could
1191 be one of the following options: now, never, +seconds or UNIX time of
1192 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1193 to make password expire on "Mon Apr
23 12:00:00 EDT
2012" (UNIX time for this
1196 You can also use keywords "now
" or "never" for the expiration time to
1197 allow <protocol> password to expire immediately or never expire.
1201 Require that client use TLS when communicating with the VNC server. This
1202 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1203 attack. It is recommended that this option be combined with either the
1204 @option{x509} or @option{x509verify} options.
1206 @item x509=@var{/path/to/certificate/dir}
1208 Valid if @option{tls} is specified. Require that x509 credentials are used
1209 for negotiating the TLS session. The server will send its x509 certificate
1210 to the client. It is recommended that a password be set on the VNC server
1211 to provide authentication of the client when this is used. The path following
1212 this option specifies where the x509 certificates are to be loaded from.
1213 See the @ref{vnc_security} section for details on generating certificates.
1215 @item x509verify=@var{/path/to/certificate/dir}
1217 Valid if @option{tls} is specified. Require that x509 credentials are used
1218 for negotiating the TLS session. The server will send its x509 certificate
1219 to the client, and request that the client send its own x509 certificate.
1220 The server will validate the client's certificate against the CA certificate,
1221 and reject clients when validation fails. If the certificate authority is
1222 trusted, this is a sufficient authentication mechanism. You may still wish
1223 to set a password on the VNC server as a second authentication layer. The
1224 path following this option specifies where the x509 certificates are to
1225 be loaded from. See the @ref{vnc_security} section for details on generating
1230 Require that the client use SASL to authenticate with the VNC server.
1231 The exact choice of authentication method used is controlled from the
1232 system / user's SASL configuration file for the 'qemu' service. This
1233 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1234 unprivileged user, an environment variable SASL_CONF_PATH can be used
1235 to make it search alternate locations for the service config.
1236 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1237 it is recommended that SASL always be combined with the 'tls' and
1238 'x509' settings to enable use of SSL and server certificates. This
1239 ensures a data encryption preventing compromise of authentication
1240 credentials. See the @ref{vnc_security} section for details on using
1241 SASL authentication.
1245 Turn on access control lists for checking of the x509 client certificate
1246 and SASL party. For x509 certs, the ACL check is made against the
1247 certificate's distinguished name. This is something that looks like
1248 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1249 made against the username, which depending on the SASL plugin, may
1250 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1251 When the @option{acl} flag is set, the initial access list will be
1252 empty, with a @code{deny} policy. Thus no one will be allowed to
1253 use the VNC server until the ACLs have been loaded. This can be
1254 achieved using the @code{acl} monitor command.
1258 Enable lossy compression methods (gradient, JPEG, ...). If this
1259 option is set, VNC client may receive lossy framebuffer updates
1260 depending on its encoding settings. Enabling this option can save
1261 a lot of bandwidth at the expense of quality.
1265 Disable adaptive encodings. Adaptive encodings are enabled by default.
1266 An adaptive encoding will try to detect frequently updated screen regions,
1267 and send updates in these regions using a lossy encoding (like JPEG).
1268 This can be really helpful to save bandwidth when playing videos. Disabling
1269 adaptive encodings restores the original static behavior of encodings
1272 @item share=[allow-exclusive|force-shared|ignore]
1274 Set display sharing policy. 'allow-exclusive' allows clients to ask
1275 for exclusive access. As suggested by the rfb spec this is
1276 implemented by dropping other connections. Connecting multiple
1277 clients in parallel requires all clients asking for a shared session
1278 (vncviewer: -shared switch). This is the default. 'force-shared'
1279 disables exclusive client access. Useful for shared desktop sessions,
1280 where you don't want someone forgetting specify -shared disconnect
1281 everybody else. 'ignore' completely ignores the shared flag and
1282 allows everybody connect unconditionally. Doesn't conform to the rfb
1283 spec but is traditional QEMU behavior.
1291 ARCHHEADING(, QEMU_ARCH_I386)
1293 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1298 DEF("win2k
-hack
", 0, QEMU_OPTION_win2k_hack,
1299 "-win2k
-hack use it when installing Windows
2000 to avoid a disk full bug
\n",
1304 Use it when installing Windows 2000 to avoid a disk full bug. After
1305 Windows 2000 is installed, you no longer need this option (this option
1306 slows down the IDE transfers).
1309 HXCOMM Deprecated by -rtc
1310 DEF("rtc
-td
-hack
", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1312 DEF("no
-fd
-bootchk
", 0, QEMU_OPTION_no_fd_bootchk,
1313 "-no
-fd
-bootchk disable boot signature checking
for floppy disks
\n",
1316 @item -no-fd-bootchk
1317 @findex -no-fd-bootchk
1318 Disable boot signature checking for floppy disks in BIOS. May
1319 be needed to boot from old floppy disks.
1322 DEF("no
-acpi
", 0, QEMU_OPTION_no_acpi,
1323 "-no
-acpi disable ACPI
\n", QEMU_ARCH_I386)
1327 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1328 it if your guest OS complains about ACPI problems (PC target machine
1332 DEF("no
-hpet
", 0, QEMU_OPTION_no_hpet,
1333 "-no
-hpet disable HPET
\n", QEMU_ARCH_I386)
1337 Disable HPET support.
1340 DEF("acpitable
", HAS_ARG, QEMU_OPTION_acpitable,
1341 "-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"
1342 " ACPI table description
\n", QEMU_ARCH_I386)
1344 @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}]...]
1346 Add ACPI table with specified header fields and context from specified files.
1347 For file=, take whole ACPI table from the specified files, including all
1348 ACPI headers (possible overridden by other options).
1349 For data=, only data
1350 portion of the table is used, all header information is specified in the
1354 DEF("smbios
", HAS_ARG, QEMU_OPTION_smbios,
1355 "-smbios file
=binary
\n"
1356 " load SMBIOS entry from binary file
\n"
1357 "-smbios type
=0[,vendor
=str
][,version
=str
][,date
=str
][,release
=%d
.%d
][,uefi
=on|off
]\n"
1358 " specify SMBIOS type
0 fields
\n"
1359 "-smbios type
=1[,manufacturer
=str
][,product
=str
][,version
=str
][,serial
=str
]\n"
1360 " [,uuid
=uuid
][,sku
=str
][,family
=str
]\n"
1361 " specify SMBIOS type
1 fields
\n", QEMU_ARCH_I386)
1363 @item -smbios file=@var{binary}
1365 Load SMBIOS entry from binary file.
1367 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1368 Specify SMBIOS type 0 fields
1370 @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}]
1371 Specify SMBIOS type 1 fields
1379 DEFHEADING(Network options:)
1384 HXCOMM Legacy slirp options (now moved to -net user):
1386 DEF("tftp
", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1387 DEF("bootp
", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1388 DEF("redir
", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1390 DEF("smb
", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1394 DEF("net
", HAS_ARG, QEMU_OPTION_net,
1395 "-net nic
[,vlan
=n
][,macaddr
=mac
][,model
=type
][,name
=str
][,addr
=str
][,vectors
=v
]\n"
1396 " create a
new Network Interface Card and connect it to VLAN
'n'\n"
1398 "-net user
[,vlan
=n
][,name
=str
][,net
=addr
[/mask
]][,host
=addr
][,restrict
=on|off
]\n"
1399 " [,hostname
=host
][,dhcpstart
=addr
][,dns
=addr
][,dnssearch
=domain
][,tftp
=dir
]\n"
1400 " [,bootfile
=f
][,hostfwd
=rule
][,guestfwd
=rule
]"
1402 "[,smb
=dir
[,smbserver
=addr
]]\n"
1404 " connect the user mode network stack to VLAN
'n', configure its
\n"
1405 " DHCP server and enabled optional services
\n"
1408 "-net tap
[,vlan
=n
][,name
=str
],ifname
=name
\n"
1409 " connect the host TAP network
interface to VLAN
'n'\n"
1411 "-net tap
[,vlan
=n
][,name
=str
][,fd
=h
][,fds
=x
:y
:...:z
][,ifname
=name
][,script
=file
][,downscript
=dfile
][,helper
=helper
][,sndbuf
=nbytes
][,vnet_hdr
=on|off
][,vhost
=on|off
][,vhostfd
=h
][,vhostfds
=x
:y
:...:z
][,vhostforce
=on|off
][,queues
=n
]\n"
1412 " connect the host TAP network
interface to VLAN
'n'\n"
1413 " use network scripts
'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1414 " to configure it and
'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1415 " to deconfigure it
\n"
1416 " use
'[down]script=no' to disable script execution
\n"
1417 " use network helper
'helper' (default=" DEFAULT_BRIDGE_HELPER ") to
\n"
1419 " use
'fd=h' to connect to an already opened TAP
interface\n"
1420 " use
'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces
\n"
1421 " use
'sndbuf=nbytes' to limit the size of the send
buffer (the
\n"
1422 " default is disabled
'sndbuf=0' to enable flow control set
'sndbuf=1048576')\n"
1423 " use vnet_hdr
=off to avoid enabling the IFF_VNET_HDR tap flag
\n"
1424 " use vnet_hdr
=on to make the lack of IFF_VNET_HDR support an error condition
\n"
1425 " use vhost
=on to enable experimental
in kernel accelerator
\n"
1426 " (only has effect
for virtio guests which use MSIX
)\n"
1427 " use vhostforce
=on to force vhost on
for non
-MSIX virtio guests
\n"
1428 " use
'vhostfd=h' to connect to an already opened vhost net device
\n"
1429 " use
'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1430 " use 'queues
=n
' to specify the number of queues to be created for multiqueue TAP\n"
1431 "-net bridge[,vlan=n][,name=str][,br=bridge][,helper=helper]\n"
1432 " connects a host TAP network interface to a host bridge device 'br
'\n"
1433 " (default=" DEFAULT_BRIDGE_INTERFACE ") using the program 'helper
'\n"
1434 " (default=" DEFAULT_BRIDGE_HELPER ")\n"
1437 "-net l2tpv3[,vlan=n][,name=str],src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6=on/off][,udp=on/off][,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]\n"
1438 " connect the VLAN to an Ethernet over L2TPv3 pseudowire\n"
1439 " Linux kernel 3.3+ as well as most routers can talk\n"
1440 " L2TPv3. This transport allows to connect a VM to a VM,\n"
1441 " VM to a router and even VM to Host. It is a nearly-universal\n"
1442 " standard (RFC3391). Note - this implementation uses static\n"
1443 " pre-configured tunnels (same as the Linux kernel).\n"
1444 " use 'src
=' to specify source address\n"
1445 " use 'dst
=' to specify destination address\n"
1446 " use 'udp
=on
' to specify udp encapsulation\n"
1447 " use 'dstport
=' to specify destination udp port\n"
1448 " use 'dstport
=' to specify destination udp port\n"
1449 " use 'ipv6
=on
' to force v6\n"
1450 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1451 " well as a weak security measure\n"
1452 " use 'rxcookie
=0x012345678' to specify a rxcookie\n"
1453 " use 'txcookie
=0x012345678' to specify a txcookie\n"
1454 " use 'cookie64
=on
' to set cookie size to 64 bit, otherwise 32\n"
1455 " use 'counter
=off
' to force a 'cut
-down
' L2TPv3 with no counter\n"
1456 " use 'pincounter
=on
' to work around broken counter handling in peer\n"
1457 " use 'offset
=X
' to add an extra offset between header and data\n"
1459 "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
1460 " connect the vlan 'n
' to another VLAN using a socket connection\n"
1461 "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1462 " connect the vlan 'n
' to multicast maddr and port\n"
1463 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1464 "-net socket[,vlan=n][,name=str][,fd=h][,udp=host:port][,localaddr=host:port]\n"
1465 " connect the vlan 'n
' to another VLAN using an UDP tunnel\n"
1467 "-net vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1468 " connect the vlan 'n
' to port 'n
' of a vde switch running\n"
1469 " on host and listening for incoming connections on 'socketpath
'.\n"
1470 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1471 " ownership and permissions for communication port.\n"
1473 #ifdef CONFIG_NETMAP
1474 "-net netmap,ifname=name[,devname=nmname]\n"
1475 " attach to the existing netmap-enabled network interface 'name
', or to a\n"
1476 " VALE port (created on the fly) called 'name
' ('nmname
' is name of the \n"
1477 " netmap device, defaults to '/dev
/netmap
')\n"
1479 "-net dump[,vlan=n][,file=f][,len=n]\n"
1480 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
1481 "-net none use it alone to have zero network devices. If no -net option\n"
1482 " is provided, the default is '-net nic
-net user
'\n", QEMU_ARCH_ALL)
1483 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1493 #ifdef CONFIG_NETMAP
1498 "hubport],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
1500 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1502 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1503 = 0 is the default). The NIC is an e1000 by default on the PC
1504 target. Optionally, the MAC address can be changed to @var{mac}, the
1505 device address set to @var{addr} (PCI cards only),
1506 and a @var{name} can be assigned for use in monitor commands.
1507 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1508 that the card should have; this option currently only affects virtio cards; set
1509 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1510 NIC is created. QEMU can emulate several different models of network card.
1511 Valid values for @var{type} are
1512 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1513 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1514 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1515 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1516 for a list of available devices for your target.
1518 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1520 @item -net user[,@var{option}][,@var{option}][,...]
1521 Use the user mode network stack which requires no administrator
1522 privilege to run. Valid options are:
1526 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1529 @item name=@var{name}
1530 Assign symbolic name for use in monitor commands.
1532 @item net=@var{addr}[/@var{mask}]
1533 Set IP network address the guest will see. Optionally specify the netmask,
1534 either in the form a.b.c.d or as number of valid top-most bits. Default is
1537 @item host=@var{addr}
1538 Specify the guest-visible address of the host. Default is the 2nd IP in the
1539 guest network, i.e. x.x.x.2.
1541 @item restrict=on|off
1542 If this option is enabled, the guest will be isolated, i.e. it will not be
1543 able to contact the host and no guest IP packets will be routed over the host
1544 to the outside. This option does not affect any explicitly set forwarding rules.
1546 @item hostname=@var{name}
1547 Specifies the client hostname reported by the built-in DHCP server.
1549 @item dhcpstart=@var{addr}
1550 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1551 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1553 @item dns=@var{addr}
1554 Specify the guest-visible address of the virtual nameserver. The address must
1555 be different from the host address. Default is the 3rd IP in the guest network,
1558 @item dnssearch=@var{domain}
1559 Provides an entry for the domain-search list sent by the built-in
1560 DHCP server. More than one domain suffix can be transmitted by specifying
1561 this option multiple times. If supported, this will cause the guest to
1562 automatically try to append the given domain suffix(es) in case a domain name
1563 can not be resolved.
1567 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1570 @item tftp=@var{dir}
1571 When using the user mode network stack, activate a built-in TFTP
1572 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1573 The TFTP client on the guest must be configured in binary mode (use the command
1574 @code{bin} of the Unix TFTP client).
1576 @item bootfile=@var{file}
1577 When using the user mode network stack, broadcast @var{file} as the BOOTP
1578 filename. In conjunction with @option{tftp}, this can be used to network boot
1579 a guest from a local directory.
1581 Example (using pxelinux):
1583 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1586 @item smb=@var{dir}[,smbserver=@var{addr}]
1587 When using the user mode network stack, activate a built-in SMB
1588 server so that Windows OSes can access to the host files in @file{@var{dir}}
1589 transparently. The IP address of the SMB server can be set to @var{addr}. By
1590 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1592 In the guest Windows OS, the line:
1596 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1597 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1599 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1601 Note that a SAMBA server must be installed on the host OS.
1602 QEMU was tested successfully with smbd versions from Red Hat 9,
1603 Fedora Core 3 and OpenSUSE 11.x.
1605 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1606 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1607 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1608 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1609 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1610 be bound to a specific host interface. If no connection type is set, TCP is
1611 used. This option can be given multiple times.
1613 For example, to redirect host X11 connection from screen 1 to guest
1614 screen 0, use the following:
1618 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1619 # this host xterm should open in the guest X11 server
1623 To redirect telnet connections from host port 5555 to telnet port on
1624 the guest, use the following:
1628 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1629 telnet localhost 5555
1632 Then when you use on the host @code{telnet localhost 5555}, you
1633 connect to the guest telnet server.
1635 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1636 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1637 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1638 to the character device @var{dev} or to a program executed by @var{cmd:command}
1639 which gets spawned for each connection. This option can be given multiple times.
1641 You can either use a chardev directly and have that one used throughout QEMU's
1642 lifetime
, like
in the following example
:
1645 # open
10.10.1.1:4321 on bootup
, connect
10.0.2.100:1234 to it whenever
1646 # the guest accesses it
1647 qemu
-net user
,guestfwd
=tcp
:10.0.2.100:1234-tcp
:10.10.1.1:4321 [...]
1650 Or you can execute a command on every TCP connection established by the guest
,
1651 so that QEMU behaves similar to an inetd process
for that virtual server
:
1654 # call
"netcat 10.10.1.1 4321" on every TCP connection to
10.0.2.100:1234
1655 # and connect the TCP stream to its stdin
/stdout
1656 qemu
-net
'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1661 Note
: Legacy stand
-alone options
-tftp
, -bootp
, -smb and
-redir are still
1662 processed and applied to
-net user
. Mixing them with the
new configuration
1663 syntax gives undefined results
. Their use
for new applications is discouraged
1664 as they will be removed from future versions
.
1666 @item
-netdev tap
,id
=@
var{id
}[,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1667 @item
-net tap
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1668 Connect the host TAP network
interface @
var{name
} to VLAN @
var{n
}.
1670 Use the network script @
var{file
} to configure it and the network script
1671 @
var{dfile
} to deconfigure it
. If @
var{name
} is not provided
, the OS
1672 automatically provides one
. The
default network configure script is
1673 @file
{/etc
/qemu
-ifup
} and the
default network deconfigure script is
1674 @file
{/etc
/qemu
-ifdown
}. Use @option
{script
=no
} or @option
{downscript
=no
}
1675 to disable script execution
.
1677 If running QEMU as an unprivileged user
, use the network helper
1678 @
var{helper
} to configure the TAP
interface. The
default network
1679 helper executable is @file
{/path
/to
/qemu
-bridge
-helper
}.
1681 @option
{fd
}=@
var{h
} can be used to specify the handle of an already
1682 opened host TAP
interface.
1687 #launch a QEMU instance with the
default network script
1688 qemu
-system
-i386 linux
.img
-net nic
-net tap
1692 #launch a QEMU instance with two NICs
, each one connected
1694 qemu
-system
-i386 linux
.img \
1695 -net nic
,vlan
=0 -net tap
,vlan
=0,ifname
=tap0 \
1696 -net nic
,vlan
=1 -net tap
,vlan
=1,ifname
=tap1
1700 #launch a QEMU instance with the
default network helper to
1701 #connect a TAP device to bridge br0
1702 qemu
-system
-i386 linux
.img \
1703 -net nic
-net tap
,"helper=/path/to/qemu-bridge-helper"
1706 @item
-netdev bridge
,id
=@
var{id
}[,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1707 @item
-net bridge
[,vlan
=@
var{n
}][,name
=@
var{name
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1708 Connect a host TAP network
interface to a host bridge device
.
1710 Use the network helper @
var{helper
} to configure the TAP
interface and
1711 attach it to the bridge
. The
default network helper executable is
1712 @file
{/path
/to
/qemu
-bridge
-helper
} and the
default bridge
1713 device is @file
{br0
}.
1718 #launch a QEMU instance with the
default network helper to
1719 #connect a TAP device to bridge br0
1720 qemu
-system
-i386 linux
.img
-net bridge
-net nic
,model
=virtio
1724 #launch a QEMU instance with the
default network helper to
1725 #connect a TAP device to bridge qemubr0
1726 qemu
-system
-i386 linux
.img
-net bridge
,br
=qemubr0
-net nic
,model
=virtio
1729 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1730 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}] [,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1732 Connect the VLAN @
var{n
} to a remote VLAN
in another QEMU virtual
1733 machine
using a TCP socket connection
. If @option
{listen
} is
1734 specified
, QEMU waits
for incoming connections on @
var{port
}
1735 (@
var{host
} is optional
). @option
{connect
} is used to connect to
1736 another QEMU instance
using the @option
{listen
} option
. @option
{fd
}=@
var{h
}
1737 specifies an already opened TCP socket
.
1741 # launch a first QEMU instance
1742 qemu
-system
-i386 linux
.img \
1743 -net nic
,macaddr
=52:54:00:12:34:56 \
1744 -net socket
,listen
=:1234
1745 # connect the VLAN
0 of
this instance to the VLAN
0
1746 # of the first instance
1747 qemu
-system
-i386 linux
.img \
1748 -net nic
,macaddr
=52:54:00:12:34:57 \
1749 -net socket
,connect
=127.0.0.1:1234
1752 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1753 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1755 Create a VLAN @
var{n
} shared with another QEMU virtual
1756 machines
using a UDP multicast socket
, effectively making a bus
for
1757 every QEMU with same multicast address @
var{maddr
} and @
var{port
}.
1761 Several QEMU can be running on different hosts and share same
bus (assuming
1762 correct multicast setup
for these hosts
).
1764 mcast support is compatible with User Mode
Linux (argument @option
{eth@
var{N
}=mcast
}), see
1765 @url
{http
://user-mode-linux.sf.net}.
1767 Use @option
{fd
=h
} to specify an already opened UDP multicast socket
.
1772 # launch one QEMU instance
1773 qemu
-system
-i386 linux
.img \
1774 -net nic
,macaddr
=52:54:00:12:34:56 \
1775 -net socket
,mcast
=230.0.0.1:1234
1776 # launch another QEMU instance on same
"bus"
1777 qemu
-system
-i386 linux
.img \
1778 -net nic
,macaddr
=52:54:00:12:34:57 \
1779 -net socket
,mcast
=230.0.0.1:1234
1780 # launch yet another QEMU instance on same
"bus"
1781 qemu
-system
-i386 linux
.img \
1782 -net nic
,macaddr
=52:54:00:12:34:58 \
1783 -net socket
,mcast
=230.0.0.1:1234
1786 Example (User Mode Linux compat
.):
1788 # launch QEMU
instance (note mcast address selected
1790 qemu-system-i386 linux.img \
1791 -net nic,macaddr=52:54:00:12:34:56 \
1792 -net socket,mcast=239.192.168.1:1102
1794 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1797 Example (send packets from host's
1.2.3.4):
1799 qemu
-system
-i386 linux
.img \
1800 -net nic
,macaddr
=52:54:00:12:34:56 \
1801 -net socket
,mcast
=239.192.168.1:1102,localaddr
=1.2.3.4
1804 @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
}]
1805 @item
-net l2tpv3
[,vlan
=@
var{n
}][,name
=@
var{name
}],src
=@
var{srcaddr
},dst
=@
var{dstaddr
}[,srcport
=@
var{srcport
}][,dstport
=@
var{dstport
}],txsession
=@
var{txsession
}[,rxsession
=@
var{rxsession
}][,ipv6
][,udp
][,cookie64
][,counter
][,pincounter
][,txcookie
=@
var{txcookie
}][,rxcookie
=@
var{rxcookie
}][,offset
=@
var{offset
}]
1806 Connect VLAN @
var{n
} to L2TPv3 pseudowire
. L2TPv3 (RFC3391
) is a popular
1807 protocol to transport
Ethernet (and other Layer
2) data frames between
1808 two systems
. It is present
in routers
, firewalls and the Linux kernel
1809 (from version
3.3 onwards
).
1811 This transport allows a VM to communicate to another VM
, router or firewall directly
.
1813 @item src
=@
var{srcaddr
}
1814 source
address (mandatory
)
1815 @item dst
=@
var{dstaddr
}
1816 destination
address (mandatory
)
1818 select udp
encapsulation (default is ip
).
1819 @item srcport
=@
var{srcport
}
1821 @item dstport
=@
var{dstport
}
1822 destination udp port
.
1824 force v6
, otherwise defaults to v4
.
1825 @item rxcookie
=@
var{rxcookie
}
1826 @item txcookie
=@
var{txcookie
}
1827 Cookies are a weak form of security
in the l2tpv3 specification
.
1828 Their
function is mostly to prevent misconfiguration
. By
default they are
32
1831 Set cookie size to
64 bit instead of the
default 32
1833 Force a
'cut-down' L2TPv3 with no counter as
in
1834 draft
-mkonstan
-l2tpext
-keyed
-ipv6
-tunnel
-00
1836 Work around broken counter handling
in peer
. This may also help on
1837 networks which have packet reorder
.
1838 @item offset
=@
var{offset
}
1839 Add an extra offset between header and data
1841 For example
, to attach a VM running on host
4.3.2.1 via L2TPv3 to the bridge br
-lan
1842 on the remote Linux host
1.2.3.4:
1844 # Setup tunnel on linux host
using raw ip as encapsulation
1846 ip l2tp add tunnel remote
4.3.2.1 local
1.2.3.4 tunnel_id
1 peer_tunnel_id
1 \
1847 encap udp udp_sport
16384 udp_dport
16384
1848 ip l2tp add session tunnel_id
1 name vmtunnel0 session_id \
1849 0xFFFFFFFF peer_session_id
0xFFFFFFFF
1850 ifconfig vmtunnel0 mtu
1500
1851 ifconfig vmtunnel0 up
1852 brctl addif br
-lan vmtunnel0
1856 # launch QEMU instance
- if your network has reorder or is very lossy add
,pincounter
1858 qemu
-system
-i386 linux
.img
-net nic
-net l2tpv3
,src
=4.2.3.1,dst
=1.2.3.4,udp
,srcport
=16384,dstport
=16384,rxsession
=0xffffffff,txsession
=0xffffffff,counter
1863 @item
-netdev vde
,id
=@
var{id
}[,sock
=@
var{socketpath
}][,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1864 @item
-net vde
[,vlan
=@
var{n
}][,name
=@
var{name
}][,sock
=@
var{socketpath
}] [,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1865 Connect VLAN @
var{n
} to PORT @
var{n
} of a vde
switch running on host and
1866 listening
for incoming connections on @
var{socketpath
}. Use GROUP @
var{groupname
}
1867 and MODE @
var{octalmode
} to change
default ownership and permissions
for
1868 communication port
. This option is only available
if QEMU has been compiled
1869 with vde support enabled
.
1874 vde_switch
-F
-sock
/tmp
/myswitch
1875 # launch QEMU instance
1876 qemu
-system
-i386 linux
.img
-net nic
-net vde
,sock
=/tmp
/myswitch
1879 @item
-netdev hubport
,id
=@
var{id
},hubid
=@
var{hubid
}
1881 Create a hub port on QEMU
"vlan" @
var{hubid
}.
1883 The hubport netdev lets you connect a NIC to a QEMU
"vlan" instead of a single
1884 netdev
. @code
{-net
} and @code
{-device
} with parameter @option
{vlan
} create the
1885 required hub automatically
.
1887 @item
-netdev vhost
-user
,chardev
=@
var{id
}[,vhostforce
=on|off
]
1889 Establish a vhost
-user netdev
, backed by a chardev @
var{id
}. The chardev should
1890 be a unix domain socket backed one
. The vhost
-user uses a specifically defined
1891 protocol to pass vhost ioctl replacement messages to an application on the other
1892 end of the socket
. On non
-MSIX guests
, the feature can be forced with
1897 qemu
-m
512 -object memory
-backend
-file
,id
=mem
,size
=512M
,mem
-path
=/hugetlbfs
,share
=on \
1898 -numa node
,memdev
=mem \
1899 -chardev socket
,path
=/path
/to
/socket \
1900 -netdev type
=vhost
-user
,id
=net0
,chardev
=chr0 \
1901 -device virtio
-net
-pci
,netdev
=net0
1904 @item
-net dump
[,vlan
=@
var{n
}][,file
=@
var{file
}][,len
=@
var{len
}]
1905 Dump network traffic on VLAN @
var{n
} to file @
var{file
} (@file
{qemu
-vlan0
.pcap
} by
default).
1906 At most @
var{len
} bytes (64k by
default) per packet are stored
. The file format is
1907 libpcap
, so it can be analyzed with tools such as tcpdump or Wireshark
.
1910 Indicate that no network devices should be configured
. It is used to
1911 override the
default configuration (@option
{-net nic
-net user
}) which
1912 is activated
if no @option
{-net
} options are provided
.
1920 DEFHEADING(Character device options
:)
1923 The general form of a character device option is
:
1927 DEF("chardev", HAS_ARG
, QEMU_OPTION_chardev
,
1928 "-chardev null,id=id[,mux=on|off]\n"
1929 "-chardev socket,id=id[,host=host],port=host[,to=to][,ipv4][,ipv6][,nodelay]\n"
1930 " [,server][,nowait][,telnet][,mux=on|off] (tcp)\n"
1931 "-chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix)\n"
1932 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
1933 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
1934 "-chardev msmouse,id=id[,mux=on|off]\n"
1935 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
1937 "-chardev ringbuf,id=id[,size=size]\n"
1938 "-chardev file,id=id,path=path[,mux=on|off]\n"
1939 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
1941 "-chardev console,id=id[,mux=on|off]\n"
1942 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1944 "-chardev pty,id=id[,mux=on|off]\n"
1945 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
1947 #ifdef CONFIG_BRLAPI
1948 "-chardev braille,id=id[,mux=on|off]\n"
1950 #
if defined(__linux__
) ||
defined(__sun__
) ||
defined(__FreeBSD__
) \
1951 ||
defined(__NetBSD__
) ||
defined(__OpenBSD__
) ||
defined(__DragonFly__
)
1952 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1953 "-chardev tty,id=id,path=path[,mux=on|off]\n"
1955 #
if defined(__linux__
) ||
defined(__FreeBSD__
) ||
defined(__DragonFly__
)
1956 "-chardev parallel,id=id,path=path[,mux=on|off]\n"
1957 "-chardev parport,id=id,path=path[,mux=on|off]\n"
1959 #
if defined(CONFIG_SPICE
)
1960 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
1961 "-chardev spiceport,id=id,name=name[,debug=debug]\n"
1967 @item
-chardev @
var{backend
} ,id
=@
var{id
} [,mux
=on|off
] [,@
var{options
}]
1988 The specific backend will determine the applicable options
.
1990 All devices must have an id
, which can be any string up to
127 characters long
.
1991 It is used to uniquely identify
this device
in other command line directives
.
1993 A character device may be used
in multiplexing mode by multiple front
-ends
.
1994 The key sequence of @key
{Control
-a
} and @key
{c
} will rotate the input focus
1995 between attached front
-ends
. Specify @option
{mux
=on
} to enable
this mode
.
1997 Options to each backend are described below
.
1999 @item
-chardev
null ,id
=@
var{id
}
2000 A void device
. This device will not emit any data
, and will drop any data it
2001 receives
. The
null backend does not take any options
.
2003 @item
-chardev socket
,id
=@
var{id
} [@
var{TCP options
} or @
var{unix options
}] [,server
] [,nowait
] [,telnet
]
2005 Create a two
-way stream socket
, which can be either a TCP or a unix socket
. A
2006 unix socket will be created
if @option
{path
} is specified
. Behaviour is
2007 undefined
if TCP options are specified
for a unix socket
.
2009 @option
{server
} specifies that the socket shall be a listening socket
.
2011 @option
{nowait
} specifies that QEMU should not block waiting
for a client to
2012 connect to a listening socket
.
2014 @option
{telnet
} specifies that traffic on the socket should interpret telnet
2017 TCP and unix socket options are given below
:
2021 @item TCP options
: port
=@
var{port
} [,host
=@
var{host
}] [,to
=@
var{to
}] [,ipv4
] [,ipv6
] [,nodelay
]
2023 @option
{host
} for a listening socket specifies the local address to be bound
.
2024 For a connecting socket species the remote host to connect to
. @option
{host
} is
2025 optional
for listening sockets
. If not specified it defaults to @code
{0.0.0.0}.
2027 @option
{port
} for a listening socket specifies the local port to be bound
. For a
2028 connecting socket specifies the port on the remote host to connect to
.
2029 @option
{port
} can be given as either a port number or a service name
.
2030 @option
{port
} is required
.
2032 @option
{to
} is only relevant to listening sockets
. If it is specified
, and
2033 @option
{port
} cannot be bound
, QEMU will attempt to bind to subsequent ports up
2034 to and including @option
{to
} until it succeeds
. @option
{to
} must be specified
2037 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2038 If neither is specified the socket may use either protocol
.
2040 @option
{nodelay
} disables the Nagle algorithm
.
2042 @item unix options
: path
=@
var{path
}
2044 @option
{path
} specifies the local path of the unix socket
. @option
{path
} is
2049 @item
-chardev udp
,id
=@
var{id
} [,host
=@
var{host
}] ,port
=@
var{port
} [,localaddr
=@
var{localaddr
}] [,localport
=@
var{localport
}] [,ipv4
] [,ipv6
]
2051 Sends all traffic from the guest to a remote host over UDP
.
2053 @option
{host
} specifies the remote host to connect to
. If not specified it
2054 defaults to @code
{localhost
}.
2056 @option
{port
} specifies the port on the remote host to connect to
. @option
{port
}
2059 @option
{localaddr
} specifies the local address to bind to
. If not specified it
2060 defaults to @code
{0.0.0.0}.
2062 @option
{localport
} specifies the local port to bind to
. If not specified any
2063 available local port will be used
.
2065 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2066 If neither is specified the device may use either protocol
.
2068 @item
-chardev msmouse
,id
=@
var{id
}
2070 Forward QEMU
's emulated msmouse events to the guest. @option{msmouse} does not
2073 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2075 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2078 @option{width} and @option{height} specify the width and height respectively of
2079 the console, in pixels.
2081 @option{cols} and @option{rows} specify that the console be sized to fit a text
2082 console with the given dimensions.
2084 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2086 Create a ring buffer with fixed size @option{size}.
2087 @var{size} must be a power of two, and defaults to @code{64K}).
2089 @item -chardev file ,id=@var{id} ,path=@var{path}
2091 Log all traffic received from the guest to a file.
2093 @option{path} specifies the path of the file to be opened. This file will be
2094 created if it does not already exist, and overwritten if it does. @option{path}
2097 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2099 Create a two-way connection to the guest. The behaviour differs slightly between
2100 Windows hosts and other hosts:
2102 On Windows, a single duplex pipe will be created at
2103 @file{\\.pipe\@option{path}}.
2105 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2106 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2107 received by the guest. Data written by the guest can be read from
2108 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2111 @option{path} forms part of the pipe path as described above. @option{path} is
2114 @item -chardev console ,id=@var{id}
2116 Send traffic from the guest to QEMU's standard output
. @option
{console
} does not
2119 @option
{console
} is only available on Windows hosts
.
2121 @item
-chardev serial
,id
=@
var{id
} ,path
=@option
{path
}
2123 Send traffic from the guest to a serial device on the host
.
2125 On Unix hosts serial will actually accept any tty device
,
2126 not only serial lines
.
2128 @option
{path
} specifies the name of the serial device to open
.
2130 @item
-chardev pty
,id
=@
var{id
}
2132 Create a
new pseudo
-terminal on the host and connect to it
. @option
{pty
} does
2133 not take any options
.
2135 @option
{pty
} is not available on Windows hosts
.
2137 @item
-chardev stdio
,id
=@
var{id
} [,signal
=on|off
]
2138 Connect to standard input and standard output of the QEMU process
.
2140 @option
{signal
} controls
if signals are enabled on the terminal
, that includes
2141 exiting QEMU with the key sequence @key
{Control
-c
}. This option is enabled by
2142 default, use @option
{signal
=off
} to disable it
.
2144 @option
{stdio
} is not available on Windows hosts
.
2146 @item
-chardev braille
,id
=@
var{id
}
2148 Connect to a local BrlAPI server
. @option
{braille
} does not take any options
.
2150 @item
-chardev tty
,id
=@
var{id
} ,path
=@
var{path
}
2152 @option
{tty
} is only available on Linux
, Sun
, FreeBSD
, NetBSD
, OpenBSD and
2153 DragonFlyBSD hosts
. It is an alias
for @option
{serial
}.
2155 @option
{path
} specifies the path to the tty
. @option
{path
} is required
.
2157 @item
-chardev parallel
,id
=@
var{id
} ,path
=@
var{path
}
2158 @item
-chardev parport
,id
=@
var{id
} ,path
=@
var{path
}
2160 @option
{parallel
} is only available on Linux
, FreeBSD and DragonFlyBSD hosts
.
2162 Connect to a local parallel port
.
2164 @option
{path
} specifies the path to the parallel port device
. @option
{path
} is
2167 @item
-chardev spicevmc
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2169 @option
{spicevmc
} is only available when spice support is built
in.
2171 @option
{debug
} debug level
for spicevmc
2173 @option
{name
} name of spice channel to connect to
2175 Connect to a spice virtual machine channel
, such as vdiport
.
2177 @item
-chardev spiceport
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2179 @option
{spiceport
} is only available when spice support is built
in.
2181 @option
{debug
} debug level
for spicevmc
2183 @option
{name
} name of spice port to connect to
2185 Connect to a spice port
, allowing a Spice client to handle the traffic
2186 identified by a
name (preferably a fqdn
).
2194 DEFHEADING(Device URL Syntax
:)
2197 In addition to
using normal file images
for the emulated storage devices
,
2198 QEMU can also use networked resources such as iSCSI devices
. These are
2199 specified
using a special URL syntax
.
2203 iSCSI support allows QEMU to access iSCSI resources directly and use as
2204 images
for the guest storage
. Both disk and cdrom images are supported
.
2206 Syntax
for specifying iSCSI LUNs is
2207 ``iscsi
://<target-ip>[:<port>]/<target-iqn>/<lun>''
2209 By
default qemu will use the iSCSI initiator
-name
2210 'iqn.2008-11.org.linux-kvm[:<name>]' but
this can also be set from the command
2211 line or a configuration file
.
2214 Example (without authentication
):
2216 qemu
-system
-i386
-iscsi initiator
-name
=iqn
.2001-04.com
.example
:my
-initiator \
2217 -cdrom iscsi
://192.0.2.1/iqn.2001-04.com.example/2 \
2218 -drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2221 Example (CHAP username
/password via URL
):
2223 qemu
-system
-i386
-drive file
=iscsi
://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2226 Example (CHAP username
/password via environment variables
):
2228 LIBISCSI_CHAP_USERNAME
="user" \
2229 LIBISCSI_CHAP_PASSWORD
="password" \
2230 qemu
-system
-i386
-drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2233 iSCSI support is an optional feature of QEMU and only available when
2234 compiled and linked against libiscsi
.
2236 DEF("iscsi", HAS_ARG
, QEMU_OPTION_iscsi
,
2237 "-iscsi [user=user][,password=password]\n"
2238 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2239 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2240 " iSCSI session parameters\n", QEMU_ARCH_ALL
)
2243 iSCSI parameters such as username and password can also be specified via
2244 a configuration file
. See qemu
-doc
for more information and examples
.
2247 QEMU supports
NBD (Network Block Devices
) both
using TCP protocol as well
2248 as Unix Domain Sockets
.
2250 Syntax
for specifying a NBD device
using TCP
2251 ``nbd
:<server
-ip
>:<port
>[:exportname
=<export
>]''
2253 Syntax
for specifying a NBD device
using Unix Domain Sockets
2254 ``nbd
:unix
:<domain
-socket
>[:exportname
=<export
>]''
2259 qemu
-system
-i386
--drive file
=nbd
:192.0.2.1:30000
2262 Example
for Unix Domain Sockets
2264 qemu
-system
-i386
--drive file
=nbd
:unix
:/tmp
/nbd
-socket
2268 QEMU supports
SSH (Secure Shell
) access to remote disks
.
2272 qemu
-system
-i386
-drive file
=ssh
://user@@host/path/to/disk.img
2273 qemu
-system
-i386
-drive file
.driver
=ssh
,file
.user
=user
,file
.host
=host
,file
.port
=22,file
.path
=/path
/to
/disk
.img
2276 Currently authentication must be done
using ssh
-agent
. Other
2277 authentication methods may be supported
in future
.
2280 Sheepdog is a distributed storage system
for QEMU
.
2281 QEMU supports
using either local sheepdog devices or remote networked
2284 Syntax
for specifying a sheepdog device
2286 sheepdog
[+tcp|
+unix
]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2291 qemu
-system
-i386
--drive file
=sheepdog
://192.0.2.1:30000/MyVirtualMachine
2294 See also @url
{http
://http://www.osrg.net/sheepdog/}.
2297 GlusterFS is an user space distributed file system
.
2298 QEMU supports the use of GlusterFS volumes
for hosting VM disk images
using
2299 TCP
, Unix Domain Sockets and RDMA transport protocols
.
2301 Syntax
for specifying a VM disk image on GlusterFS volume is
2303 gluster
[+transport
]://[server[:port]]/volname/image[?socket=...]
2309 qemu
-system
-x86_64
--drive file
=gluster
://192.0.2.1/testvol/a.img
2312 See also @url
{http
://www.gluster.org}.
2314 @item HTTP
/HTTPS
/FTP
/FTPS
/TFTP
2315 QEMU supports read
-only access to files accessed over
http(s
), ftp(s
) and tftp
.
2317 Syntax
using a single filename
:
2319 <protocol
>://[<username>[:<password>]@@]<host>/<path>
2325 'http', 'https', 'ftp', 'ftps', or
'tftp'.
2328 Optional username
for authentication to the remote server
.
2331 Optional password
for authentication to the remote server
.
2334 Address of the remote server
.
2337 Path on the remote server
, including any query string
.
2340 The following options are also supported
:
2343 The full URL when passing options to the driver explicitly
.
2346 The amount of data to read ahead with each range request to the remote server
.
2347 This value may optionally have the suffix
'T', 'G', 'M', 'K', 'k' or
'b'. If it
2348 does not have a suffix
, it will be assumed to be
in bytes
. The value must be a
2349 multiple of
512 bytes
. It defaults to
256k
.
2352 Whether to verify the remote server
's certificate when connecting over SSL. It
2353 can have the value 'on
' or 'off
'. It defaults to 'on
'.
2356 Note that when passing options to qemu explicitly, @option{driver} is the value
2359 Example: boot from a remote Fedora 20 live ISO image
2361 qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2363 qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2366 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2367 writes, copy-on-read, and a readahead of 64k
2369 qemu-img create -f qcow2 -o backing_file='json
:@
{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@
}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2
2371 qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
2374 Example: boot from an image stored on a VMware vSphere server with a self-signed
2375 certificate using a local overlay for writes and a readahead of 64k
2377 qemu-img create -f qcow2 -o backing_file='json
:@
{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k"@
}' /tmp/test.qcow2
2379 qemu-system-x86_64 -drive file=/tmp/test.qcow2
2387 DEFHEADING(Bluetooth(R) options:)
2392 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2393 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands
\n" \
2394 "-bt hci
,host
[:id
]\n" \
2395 " use host
's HCI with the given name\n" \
2396 "-bt hci[,vlan=n]\n" \
2397 " emulate a standard HCI in virtual scatternet 'n
'\n" \
2398 "-bt vhci[,vlan=n]\n" \
2399 " add host computer to virtual scatternet 'n
' using VHCI\n" \
2400 "-bt device:dev[,vlan=n]\n" \
2401 " emulate a bluetooth device 'dev
' in scatternet 'n
'\n",
2406 Defines the function of the corresponding Bluetooth HCI. -bt options
2407 are matched with the HCIs present in the chosen machine type. For
2408 example when emulating a machine with only one HCI built into it, only
2409 the first @code{-bt hci[...]} option is valid and defines the HCI's
2410 logic
. The Transport Layer is decided by the machine type
. Currently
2411 the machines @code
{n800
} and @code
{n810
} have one HCI and all other
2415 The following three types are recognized
:
2419 (default) The corresponding Bluetooth HCI assumes no internal logic
2420 and will not respond to any HCI commands or emit events
.
2422 @item
-bt hci
,host
[:@
var{id
}]
2423 (@code
{bluez
} only
) The corresponding HCI passes commands
/ events
2424 to
/ from the physical HCI identified by the name @
var{id
} (default:
2425 @code
{hci0
}) on the computer running QEMU
. Only available on @code
{bluez
}
2426 capable systems like Linux
.
2428 @item
-bt hci
[,vlan
=@
var{n
}]
2429 Add a virtual
, standard HCI that will participate
in the Bluetooth
2430 scatternet @
var{n
} (default @code
{0}). Similarly to @option
{-net
}
2431 VLANs
, devices inside a bluetooth network @
var{n
} can only communicate
2432 with other devices
in the same
network (scatternet
).
2435 @item
-bt vhci
[,vlan
=@
var{n
}]
2436 (Linux
-host only
) Create a HCI
in scatternet @
var{n
} (default 0) attached
2437 to the host bluetooth stack instead of to the emulated target
. This
2438 allows the host and target machines to participate
in a common scatternet
2439 and communicate
. Requires the Linux @code
{vhci
} driver installed
. Can
2440 be used as following
:
2443 qemu
-system
-i386
[...OPTIONS
...] -bt hci
,vlan
=5 -bt vhci
,vlan
=5
2446 @item
-bt device
:@
var{dev
}[,vlan
=@
var{n
}]
2447 Emulate a bluetooth device @
var{dev
} and place it
in network @
var{n
}
2448 (default @code
{0}). QEMU can only emulate one type of bluetooth devices
2453 Virtual wireless keyboard implementing the HIDP bluetooth profile
.
2463 DEFHEADING(TPM device options
:)
2465 DEF("tpmdev", HAS_ARG
, QEMU_OPTION_tpmdev
, \
2466 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2467 " use path to provide path to a character device; default is /dev/tpm0\n"
2468 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2469 " not provided it will be searched for in /sys/class/misc/tpm?/device\n",
2473 The general form of a TPM device option is
:
2476 @item
-tpmdev @
var{backend
} ,id
=@
var{id
} [,@
var{options
}]
2478 Backend type must be
:
2479 @option
{passthrough
}.
2481 The specific backend type will determine the applicable options
.
2482 The @code
{-tpmdev
} option creates the TPM backend and requires a
2483 @code
{-device
} option that specifies the TPM frontend
interface model
.
2485 Options to each backend are described below
.
2487 Use
'help' to print all available TPM backend types
.
2492 @item
-tpmdev passthrough
, id
=@
var{id
}, path
=@
var{path
}, cancel
-path
=@
var{cancel
-path
}
2494 (Linux
-host only
) Enable access to the host
's TPM using the passthrough
2497 @option{path} specifies the path to the host's TPM device
, i
.e
., on
2498 a Linux host
this would be @code
{/dev
/tpm0
}.
2499 @option
{path
} is optional and by
default @code
{/dev
/tpm0
} is used
.
2501 @option
{cancel
-path
} specifies the path to the host TPM device
's sysfs
2502 entry allowing for cancellation of an ongoing TPM command.
2503 @option{cancel-path} is optional and by default QEMU will search for the
2506 Some notes about using the host's TPM with the passthrough driver
:
2508 The TPM device accessed by the passthrough driver must not be
2509 used by any other application on the host
.
2511 Since the host
's firmware (BIOS/UEFI) has already initialized the TPM,
2512 the VM's
firmware (BIOS
/UEFI
) will not be able to initialize the
2513 TPM again and may therefore not show a TPM
-specific menu that would
2514 otherwise allow the user to configure the TPM
, e
.g
., allow the user to
2515 enable
/disable or activate
/deactivate the TPM
.
2516 Further
, if TPM ownership is released from within a VM then the host
's TPM
2517 will get disabled and deactivated. To enable and activate the
2518 TPM again afterwards, the host has to be rebooted and the user is
2519 required to enter the firmware's menu to enable and activate the TPM
.
2520 If the TPM is left disabled and
/or deactivated most TPM commands will fail
.
2522 To create a passthrough TPM use the following two options
:
2524 -tpmdev passthrough
,id
=tpm0
-device tpm
-tis
,tpmdev
=tpm0
2526 Note that the @code
{-tpmdev
} id is @code
{tpm0
} and is referenced by
2527 @code
{tpmdev
=tpm0
} in the device option
.
2537 DEFHEADING(Linux
/Multiboot boot specific
:)
2540 When
using these options
, you can use a given Linux or Multiboot
2541 kernel without installing it
in the disk image
. It can be useful
2542 for easier testing of various kernels
.
2547 DEF("kernel", HAS_ARG
, QEMU_OPTION_kernel
, \
2548 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL
)
2550 @item
-kernel @
var{bzImage
}
2552 Use @
var{bzImage
} as kernel image
. The kernel can be either a Linux kernel
2553 or
in multiboot format
.
2556 DEF("append", HAS_ARG
, QEMU_OPTION_append
, \
2557 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL
)
2559 @item
-append @
var{cmdline
}
2561 Use @
var{cmdline
} as kernel command line
2564 DEF("initrd", HAS_ARG
, QEMU_OPTION_initrd
, \
2565 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL
)
2567 @item
-initrd @
var{file
}
2569 Use @
var{file
} as initial ram disk
.
2571 @item
-initrd
"@var{file1} arg=foo,@var{file2}"
2573 This syntax is only available with multiboot
.
2575 Use @
var{file1
} and @
var{file2
} as modules and pass arg
=foo as parameter to the
2579 DEF("dtb", HAS_ARG
, QEMU_OPTION_dtb
, \
2580 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL
)
2582 @item
-dtb @
var{file
}
2584 Use @
var{file
} as a device tree
binary (dtb
) image and pass it to the kernel
2593 DEFHEADING(Debug
/Expert options
:)
2598 DEF("serial", HAS_ARG
, QEMU_OPTION_serial
, \
2599 "-serial dev redirect the serial port to char device 'dev'\n",
2602 @item
-serial @
var{dev
}
2604 Redirect the virtual serial port to host character device
2605 @
var{dev
}. The
default device is @code
{vc
} in graphical mode and
2606 @code
{stdio
} in non graphical mode
.
2608 This option can be used several times to simulate up to
4 serial
2611 Use @code
{-serial none
} to disable all serial ports
.
2613 Available character devices are
:
2615 @item vc
[:@
var{W
}x@
var{H
}]
2616 Virtual console
. Optionally
, a width and height can be given
in pixel with
2620 It is also possible to specify width or height
in characters
:
2625 [Linux only
] Pseudo
TTY (a
new PTY is automatically allocated
)
2627 No device is allocated
.
2630 @item chardev
:@
var{id
}
2631 Use a named character device defined with the @code
{-chardev
} option
.
2633 [Linux only
] Use host tty
, e
.g
. @file
{/dev
/ttyS0
}. The host serial port
2634 parameters are set according to the emulated ones
.
2635 @item
/dev
/parport@
var{N
}
2636 [Linux only
, parallel port only
] Use host parallel port
2637 @
var{N
}. Currently SPP and EPP parallel port features can be used
.
2638 @item file
:@
var{filename
}
2639 Write output to @
var{filename
}. No character can be read
.
2641 [Unix only
] standard input
/output
2642 @item pipe
:@
var{filename
}
2643 name pipe @
var{filename
}
2645 [Windows only
] Use host serial port @
var{n
}
2646 @item udp
:[@
var{remote_host
}]:@
var{remote_port
}[@@
[@
var{src_ip
}]:@
var{src_port
}]
2647 This
implements UDP Net Console
.
2648 When @
var{remote_host
} or @
var{src_ip
} are not specified
2649 they
default to @code
{0.0.0.0}.
2650 When not
using a specified @
var{src_port
} a random port is automatically chosen
.
2652 If you just want a simple readonly console you can use @code
{netcat
} or
2653 @code
{nc
}, by starting QEMU with
: @code
{-serial udp
::4555} and nc as
:
2654 @code
{nc
-u
-l
-p
4555}. Any time QEMU writes something to that port it
2655 will appear
in the netconsole session
.
2657 If you plan to send characters back via netconsole or you want to stop
2658 and start QEMU a lot of times
, you should have QEMU use the same
2659 source port each time by
using something like @code
{-serial
2660 udp
::4555@@
:4556} to QEMU
. Another approach is to use a patched
2661 version of netcat which can listen to a TCP port and send and receive
2662 characters via udp
. If you have a patched version of netcat which
2663 activates telnet remote echo and single char transfer
, then you can
2664 use the following options to step up a netcat redirector to allow
2665 telnet on port
5555 to access the QEMU port
.
2668 -serial udp
::4555@@
:4556
2669 @item netcat options
:
2670 -u
-P
4555 -L
0.0.0.0:4556 -t
-p
5555 -I
-T
2671 @item telnet options
:
2675 @item tcp
:[@
var{host
}]:@
var{port
}[,@
var{server
}][,nowait
][,nodelay
]
2676 The TCP Net Console has two modes of operation
. It can send the serial
2677 I
/O to a location or wait
for a connection from a location
. By
default
2678 the TCP Net Console is sent to @
var{host
} at the @
var{port
}. If you use
2679 the @
var{server
} option QEMU will wait
for a client socket application
2680 to connect to the port before continuing
, unless the @code
{nowait
}
2681 option was specified
. The @code
{nodelay
} option disables the Nagle buffering
2682 algorithm
. If @
var{host
} is omitted
, 0.0.0.0 is assumed
. Only
2683 one TCP connection at a time is accepted
. You can use @code
{telnet
} to
2684 connect to the corresponding character device
.
2686 @item Example to send tcp console to
192.168.0.2 port
4444
2687 -serial tcp
:192.168.0.2:4444
2688 @item Example to listen and wait on port
4444 for connection
2689 -serial tcp
::4444,server
2690 @item Example to not wait and listen on ip
192.168.0.100 port
4444
2691 -serial tcp
:192.168.0.100:4444,server
,nowait
2694 @item telnet
:@
var{host
}:@
var{port
}[,server
][,nowait
][,nodelay
]
2695 The telnet protocol is used instead of raw tcp sockets
. The options
2696 work the same as
if you had specified @code
{-serial tcp
}. The
2697 difference is that the port acts like a telnet server or client
using
2698 telnet option negotiation
. This will also allow you to send the
2699 MAGIC_SYSRQ sequence
if you use a telnet that supports sending the
break
2700 sequence
. Typically
in unix telnet you
do it with Control
-] and then
2701 type
"send break" followed by pressing the enter key
.
2703 @item unix
:@
var{path
}[,server
][,nowait
]
2704 A unix domain socket is used instead of a tcp socket
. The option works the
2705 same as
if you had specified @code
{-serial tcp
} except the unix domain socket
2706 @
var{path
} is used
for connections
.
2708 @item mon
:@
var{dev_string
}
2709 This is a special option to allow the monitor to be multiplexed onto
2710 another serial port
. The monitor is accessed with key sequence of
2711 @key
{Control
-a
} and then pressing @key
{c
}.
2712 @
var{dev_string
} should be any one of the serial devices specified
2713 above
. An example to multiplex the monitor onto a telnet server
2714 listening on port
4444 would be
:
2716 @item
-serial mon
:telnet
::4444,server
,nowait
2718 When the monitor is multiplexed to stdio
in this way
, Ctrl
+C will not terminate
2719 QEMU any more but will be passed to the guest instead
.
2722 Braille device
. This will use BrlAPI to display the braille output on a real
2726 Three button serial mouse
. Configure the guest to use Microsoft protocol
.
2730 DEF("parallel", HAS_ARG
, QEMU_OPTION_parallel
, \
2731 "-parallel dev redirect the parallel port to char device 'dev'\n",
2734 @item
-parallel @
var{dev
}
2736 Redirect the virtual parallel port to host device @
var{dev
} (same
2737 devices as the serial port
). On Linux hosts
, @file
{/dev
/parportN
} can
2738 be used to use hardware devices connected on the corresponding host
2741 This option can be used several times to simulate up to
3 parallel
2744 Use @code
{-parallel none
} to disable all parallel ports
.
2747 DEF("monitor", HAS_ARG
, QEMU_OPTION_monitor
, \
2748 "-monitor dev redirect the monitor to char device 'dev'\n",
2751 @item
-monitor @
var{dev
}
2753 Redirect the monitor to host device @
var{dev
} (same devices as the
2755 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2757 Use @code
{-monitor none
} to disable the
default monitor
.
2759 DEF("qmp", HAS_ARG
, QEMU_OPTION_qmp
, \
2760 "-qmp dev like -monitor but opens in 'control' mode\n",
2763 @item
-qmp @
var{dev
}
2765 Like
-monitor but opens
in 'control' mode
.
2768 DEF("mon", HAS_ARG
, QEMU_OPTION_mon
, \
2769 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL
)
2771 @item
-mon
[chardev
=]name
[,mode
=readline|control
][,default]
2773 Setup monitor on chardev @
var{name
}.
2776 DEF("debugcon", HAS_ARG
, QEMU_OPTION_debugcon
, \
2777 "-debugcon dev redirect the debug console to char device 'dev'\n",
2780 @item
-debugcon @
var{dev
}
2782 Redirect the debug console to host device @
var{dev
} (same devices as the
2783 serial port
). The debug console is an I
/O port which is typically port
2784 0xe9; writing to that I
/O port sends output to
this device
.
2785 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2789 DEF("pidfile", HAS_ARG
, QEMU_OPTION_pidfile
, \
2790 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL
)
2792 @item
-pidfile @
var{file
}
2794 Store the QEMU process PID
in @
var{file
}. It is useful
if you launch QEMU
2798 DEF("singlestep", 0, QEMU_OPTION_singlestep
, \
2799 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL
)
2803 Run the emulation
in single step mode
.
2806 DEF("S", 0, QEMU_OPTION_S
, \
2807 "-S freeze CPU at startup (use 'c' to start execution)\n",
2812 Do not start CPU at
startup (you must type
'c' in the monitor
).
2815 DEF("realtime", HAS_ARG
, QEMU_OPTION_realtime
,
2816 "-realtime [mlock=on|off]\n"
2817 " run qemu with realtime features\n"
2818 " mlock=on|off controls mlock support (default: on)\n",
2821 @item
-realtime mlock
=on|off
2823 Run qemu with realtime features
.
2824 mlocking qemu and guest memory can be enabled via @option
{mlock
=on
}
2825 (enabled by
default).
2828 DEF("gdb", HAS_ARG
, QEMU_OPTION_gdb
, \
2829 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL
)
2831 @item
-gdb @
var{dev
}
2833 Wait
for gdb connection on device @
var{dev
} (@pxref
{gdb_usage
}). Typical
2834 connections will likely be TCP
-based
, but also UDP
, pseudo TTY
, or even
2835 stdio are reasonable use
case. The latter is allowing to start QEMU from
2836 within gdb and establish the connection via a pipe
:
2838 (gdb
) target remote | exec qemu
-system
-i386
-gdb stdio
...
2842 DEF("s", 0, QEMU_OPTION_s
, \
2843 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT
"\n",
2848 Shorthand
for -gdb tcp
::1234, i
.e
. open a gdbserver on TCP port
1234
2849 (@pxref
{gdb_usage
}).
2852 DEF("d", HAS_ARG
, QEMU_OPTION_d
, \
2853 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
2856 @item
-d @
var{item1
}[,...]
2858 Enable logging of specified items
. Use
'-d help' for a list of log items
.
2861 DEF("D", HAS_ARG
, QEMU_OPTION_D
, \
2862 "-D logfile output log to logfile (default stderr)\n",
2865 @item
-D @
var{logfile
}
2867 Output log
in @
var{logfile
} instead of to stderr
2870 DEF("L", HAS_ARG
, QEMU_OPTION_L
, \
2871 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2876 Set the directory
for the BIOS
, VGA BIOS and keymaps
.
2879 DEF("bios", HAS_ARG
, QEMU_OPTION_bios
, \
2880 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL
)
2882 @item
-bios @
var{file
}
2884 Set the filename
for the BIOS
.
2887 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm
, \
2888 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL
)
2892 Enable KVM full virtualization support
. This option is only available
2893 if KVM support is enabled when compiling
.
2896 DEF("xen-domid", HAS_ARG
, QEMU_OPTION_xen_domid
,
2897 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL
)
2898 DEF("xen-create", 0, QEMU_OPTION_xen_create
,
2899 "-xen-create create domain using xen hypercalls, bypassing xend\n"
2900 " warning: should not be used when xend is in use\n",
2902 DEF("xen-attach", 0, QEMU_OPTION_xen_attach
,
2903 "-xen-attach attach to existing xen domain\n"
2904 " xend will use this when starting QEMU\n",
2907 @item
-xen
-domid @
var{id
}
2909 Specify xen guest domain @
var{id
} (XEN only
).
2912 Create domain
using xen hypercalls
, bypassing xend
.
2913 Warning
: should not be used when xend is
in use (XEN only
).
2916 Attach to existing xen domain
.
2917 xend will use
this when starting
QEMU (XEN only
).
2920 DEF("no-reboot", 0, QEMU_OPTION_no_reboot
, \
2921 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL
)
2925 Exit instead of rebooting
.
2928 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown
, \
2929 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL
)
2932 @findex
-no
-shutdown
2933 Don
't exit QEMU on guest shutdown, but instead only stop the emulation.
2934 This allows for instance switching to monitor to commit changes to the
2938 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
2939 "-loadvm [tag|id]\n" \
2940 " start right away with a saved state (loadvm in monitor)\n",
2943 @item -loadvm @var{file}
2945 Start right away with a saved state (@code{loadvm} in monitor)
2949 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
2950 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
2955 Daemonize the QEMU process after initialization. QEMU will not detach from
2956 standard IO until it is ready to receive connections on any of its devices.
2957 This option is a useful way for external programs to launch QEMU without having
2958 to cope with initialization race conditions.
2961 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
2962 "-option-rom rom load a file, rom, into the option ROM space\n",
2965 @item -option-rom @var{file}
2967 Load the contents of @var{file} as an option ROM.
2968 This option is useful to load things like EtherBoot.
2971 DEF("clock", HAS_ARG, QEMU_OPTION_clock, \
2972 "-clock force the use of the given methods for timer alarm.\n" \
2973 " To see what timers are available use '-clock help
'\n",
2976 @item -clock @var{method}
2978 Force the use of the given methods for timer alarm. To see what timers
2979 are available use @code{-clock help}.
2982 HXCOMM Options deprecated by -rtc
2983 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
2984 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
2986 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
2987 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
2988 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
2993 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
2995 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
2996 UTC or local time, respectively. @code{localtime} is required for correct date in
2997 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
2998 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3000 By default the RTC is driven by the host system time. This allows using of the
3001 RTC as accurate reference clock inside the guest, specifically if the host
3002 time is smoothly following an accurate external reference clock, e.g. via NTP.
3003 If you want to isolate the guest time from the host, you can set @option{clock}
3004 to @code{rt} instead. To even prevent it from progressing during suspension,
3005 you can set it to @code{vm}.
3007 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3008 specifically with Windows' ACPI HAL
. This option will
try to figure out how
3009 many timer interrupts were not processed by the Windows guest and will
3013 DEF("icount", HAS_ARG
, QEMU_OPTION_icount
, \
3014 "-icount [N|auto]\n" \
3015 " enable virtual instruction counter with 2^N clock ticks per\n" \
3016 " instruction\n", QEMU_ARCH_ALL
)
3018 @item
-icount
[@
var{N
}|auto
]
3020 Enable virtual instruction counter
. The virtual cpu will execute one
3021 instruction every
2^@
var{N
} ns of virtual time
. If @code
{auto
} is specified
3022 then the virtual cpu speed will be automatically adjusted to keep virtual
3023 time within a few seconds of real time
.
3025 Note that
while this option can give deterministic behavior
, it does not
3026 provide cycle accurate emulation
. Modern CPUs contain superscalar out of
3027 order cores with complex cache hierarchies
. The number of instructions
3028 executed often has little or no correlation with actual performance
.
3031 DEF("watchdog", HAS_ARG
, QEMU_OPTION_watchdog
, \
3032 "-watchdog i6300esb|ib700\n" \
3033 " enable virtual hardware watchdog [default=none]\n",
3036 @item
-watchdog @
var{model
}
3038 Create a virtual hardware watchdog device
. Once
enabled (by a guest
3039 action
), the watchdog must be periodically polled by an agent inside
3040 the guest or
else the guest will be restarted
.
3042 The @
var{model
} is the model of hardware watchdog to emulate
. Choices
3043 for model are
: @code
{ib700
} (iBASE
700) which is a very simple ISA
3044 watchdog with a single timer
, or @code
{i6300esb
} (Intel
6300ESB I
/O
3045 controller hub
) which is a much more featureful PCI
-based dual
-timer
3046 watchdog
. Choose a model
for which your guest has drivers
.
3048 Use @code
{-watchdog help
} to list available hardware models
. Only one
3049 watchdog can be enabled
for a guest
.
3052 DEF("watchdog-action", HAS_ARG
, QEMU_OPTION_watchdog_action
, \
3053 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3054 " action when watchdog fires [default=reset]\n",
3057 @item
-watchdog
-action @
var{action
}
3058 @findex
-watchdog
-action
3060 The @
var{action
} controls what QEMU will
do when the watchdog timer
3063 @code
{reset
} (forcefully reset the guest
).
3064 Other possible actions are
:
3065 @code
{shutdown
} (attempt to gracefully shutdown the guest
),
3066 @code
{poweroff
} (forcefully poweroff the guest
),
3067 @code
{pause
} (pause the guest
),
3068 @code
{debug
} (print a debug message and
continue), or
3069 @code
{none
} (do nothing
).
3071 Note that the @code
{shutdown
} action requires that the guest responds
3072 to ACPI signals
, which it may not be able to
do in the sort of
3073 situations where the watchdog would have expired
, and thus
3074 @code
{-watchdog
-action shutdown
} is not recommended
for production use
.
3079 @item
-watchdog i6300esb
-watchdog
-action pause
3080 @item
-watchdog ib700
3084 DEF("echr", HAS_ARG
, QEMU_OPTION_echr
, \
3085 "-echr chr set terminal escape character instead of ctrl-a\n",
3089 @item
-echr @
var{numeric_ascii_value
}
3091 Change the escape character used
for switching to the monitor when
using
3092 monitor and serial sharing
. The
default is @code
{0x01} when
using the
3093 @code
{-nographic
} option
. @code
{0x01} is equal to pressing
3094 @code
{Control
-a
}. You can select a different character from the ascii
3095 control keys where
1 through
26 map to Control
-a through Control
-z
. For
3096 instance you could use the either of the following to change the escape
3097 character to Control
-t
.
3104 DEF("virtioconsole", HAS_ARG
, QEMU_OPTION_virtiocon
, \
3105 "-virtioconsole c\n" \
3106 " set virtio console\n", QEMU_ARCH_ALL
)
3108 @item
-virtioconsole @
var{c
}
3109 @findex
-virtioconsole
3112 This option is maintained
for backward compatibility
.
3114 Please use @code
{-device virtconsole
} for the
new way of invocation
.
3117 DEF("show-cursor", 0, QEMU_OPTION_show_cursor
, \
3118 "-show-cursor show cursor\n", QEMU_ARCH_ALL
)
3121 @findex
-show
-cursor
3125 DEF("tb-size", HAS_ARG
, QEMU_OPTION_tb_size
, \
3126 "-tb-size n set TB size\n", QEMU_ARCH_ALL
)
3128 @item
-tb
-size @
var{n
}
3133 DEF("incoming", HAS_ARG
, QEMU_OPTION_incoming
, \
3134 "-incoming p prepare for incoming migration, listen on port p\n",
3137 @item
-incoming @
var{port
}
3139 Prepare
for incoming migration
, listen on @
var{port
}.
3142 DEF("nodefaults", 0, QEMU_OPTION_nodefaults
, \
3143 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL
)
3147 Don
't create default devices. Normally, QEMU sets the default devices like serial
3148 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3149 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3154 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3155 "-chroot dir chroot to dir just before starting the VM\n",
3159 @item -chroot @var{dir}
3161 Immediately before starting guest execution, chroot to the specified
3162 directory. Especially useful in combination with -runas.
3166 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3167 "-runas user change to user id user just before starting the VM\n",
3171 @item -runas @var{user}
3173 Immediately before starting guest execution, drop root privileges, switching
3174 to the specified user.
3177 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3178 "-prom-env variable=value\n"
3179 " set OpenBIOS nvram variables\n",
3180 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3182 @item -prom-env @var{variable}=@var{value}
3184 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3186 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3187 "-semihosting semihosting mode\n",
3188 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32)
3191 @findex -semihosting
3192 Semihosting mode (ARM, M68K, Xtensa only).
3194 DEF("old-param", 0, QEMU_OPTION_old_param,
3195 "-old-param old param mode\n", QEMU_ARCH_ARM)
3198 @findex -old-param (ARM)
3199 Old param mode (ARM only).
3202 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3203 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off
').\n",
3206 @item -sandbox @var{arg}
3208 Enable Seccomp mode 2 system call filter. 'on
' will enable syscall filtering and 'off
' will
3209 disable it. The default is 'off
'.
3212 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3213 "-readconfig <file>\n", QEMU_ARCH_ALL)
3215 @item -readconfig @var{file}
3217 Read device configuration from @var{file}. This approach is useful when you want to spawn
3218 QEMU process with many command line options but you don't want to exceed the command line
3221 DEF("writeconfig", HAS_ARG
, QEMU_OPTION_writeconfig
,
3222 "-writeconfig <file>\n"
3223 " read/write config file\n", QEMU_ARCH_ALL
)
3225 @item
-writeconfig @
var{file
}
3226 @findex
-writeconfig
3227 Write device configuration to @
var{file
}. The @
var{file
} can be either filename to save
3228 command line and device configuration into file or dash @code
{-}) character to print the
3229 output to stdout
. This can be later used as input file
for @code
{-readconfig
} option
.
3231 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig
,
3233 " do not load default config files at startup\n",
3237 @findex
-nodefconfig
3238 Normally QEMU loads configuration files from @
var{sysconfdir
} and @
var{datadir
} at startup
.
3239 The @code
{-nodefconfig
} option will prevent QEMU from loading any of those config files
.
3241 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig
,
3243 " do not load user-provided config files at startup\n",
3246 @item
-no
-user
-config
3247 @findex
-no
-user
-config
3248 The @code
{-no
-user
-config
} option makes QEMU not load any of the user
-provided
3249 config files on @
var{sysconfdir
}, but won
't make it skip the QEMU-provided config
3250 files from @var{datadir}.
3252 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3253 "-trace [events=<file>][,file=<file>]\n"
3254 " specify tracing options\n",
3257 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3258 HXCOMM HX does not support conditional compilation of text.
3259 @item -trace [events=@var{file}][,file=@var{file}]
3262 Specify tracing options.
3265 @item events=@var{file}
3266 Immediately enable events listed in @var{file}.
3267 The file must contain one event name (as listed in the @var{trace-events} file)
3269 This option is only available if QEMU has been compiled with
3270 either @var{simple} or @var{stderr} tracing backend.
3271 @item file=@var{file}
3272 Log output traces to @var{file}.
3274 This option is only available if QEMU has been compiled with
3275 the @var{simple} tracing backend.
3280 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3281 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3284 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3285 "-enable-fips enable FIPS 140-2 compliance\n",
3290 @findex -enable-fips
3291 Enable FIPS 140-2 compliance mode.
3294 HXCOMM Deprecated by -machine accel=tcg property
3295 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3297 HXCOMM Deprecated by kvm-pit driver properties
3298 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3301 HXCOMM Deprecated (ignored)
3302 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
3304 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3305 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3307 HXCOMM Deprecated (ignored)
3308 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3310 DEF("object", HAS_ARG, QEMU_OPTION_object,
3311 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3312 " create an new object of type TYPENAME setting properties\n"
3313 " in the order they are specified. Note that the 'id
'\n"
3314 " property must be set. These objects are placed in the\n"
3315 " '/objects
' path.\n",
3318 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3320 Create an new object of type @var{typename} setting properties
3321 in the order they are specified. Note that the 'id
'
3322 property must be set. These objects are placed in the
3326 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3327 "-msg timestamp[=on|off]\n"
3328 " change the format of messages\n"
3329 " on|off controls leading timestamps (default:on)\n",
3332 @item -msg timestamp[=on|off]
3334 prepend a timestamp to each log message.(default:on)
3337 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3338 "-dump-vmstate <file>\n"
3339 " Output vmstate information in JSON format to file.\n"
3340 " Use the scripts/vmstate-static-checker.py file to\n"
3341 " check for possible regressions in migration code\n"
3342 " by comparing two such vmstate dumps.",
3345 @item -dump-vmstate @var{file}
3346 @findex -dump-vmstate
3347 Dump json-encoded vmstate information for current machine type to file
3351 HXCOMM This is the last statement. Insert new options before this line!