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"
39 " iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n",
42 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
44 Select the emulated machine by @
var{name
}. Use @code
{-machine help
} to list
45 available machines
. Supported machine properties are
:
47 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
48 This is used to enable an accelerator
. Depending on the target architecture
,
49 kvm
, xen
, or tcg can be available
. By
default, tcg is used
. If there is more
50 than one accelerator specified
, the next one is used
if the previous one fails
52 @item kernel_irqchip
=on|off
53 Enables
in-kernel irqchip support
for the chosen accelerator when available
.
54 @item kvm_shadow_mem
=size
55 Defines the size of the KVM shadow MMU
.
56 @item dump
-guest
-core
=on|off
57 Include guest memory
in a core dump
. The
default is on
.
58 @item mem
-merge
=on|off
59 Enables or disables memory merge support
. This feature
, when supported by
60 the host
, de
-duplicates identical memory pages among VMs instances
63 Enables or disables emulated Intel
IOMMU (VT
-d
) support
. The
default is off
.
67 HXCOMM Deprecated by
-machine
68 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
70 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
71 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
73 @item
-cpu @
var{model
}
75 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
78 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
79 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
80 " set the number of CPUs to 'n' [default=1]\n"
81 " maxcpus= maximum number of total cpus, including\n"
82 " offline CPUs for hotplug, etc\n"
83 " cores= number of CPU cores on one socket\n"
84 " threads= number of threads on one CPU core\n"
85 " sockets= number of discrete sockets in the system\n",
88 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
90 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
91 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
93 For the PC target
, the number of @
var{cores
} per socket
, the number
94 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
95 specified
. Missing values will be computed
. If any on the three values is
96 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
97 specifies the maximum number of hotpluggable CPUs
.
100 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
101 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n"
102 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL
)
104 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
105 @item
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
107 Simulate a multi node NUMA system
. If @samp
{mem
}, @samp
{memdev
}
108 and @samp
{cpus
} are omitted
, resources are split equally
. Also
, note
109 that the
-@option
{numa
} option doesn
't allocate any of the specified
110 resources. That is, it just assigns existing resources to NUMA nodes. This
111 means that one still has to use the @option{-m}, @option{-smp} options
112 to allocate RAM and VCPUs respectively, and possibly @option{-object}
113 to specify the memory backend for the @samp{memdev} suboption.
115 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
116 node uses @samp{memdev}, all of them have to use it.
119 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
120 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
121 " Add 'fd
' to fd 'set
'\n", QEMU_ARCH_ALL)
123 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
126 Add a file descriptor to an fd set. Valid options are:
130 This option defines the file descriptor of which a duplicate is added to fd set.
131 The file descriptor cannot be stdin, stdout, or stderr.
133 This option defines the ID of the fd set to add the file descriptor to.
134 @item opaque=@var{opaque}
135 This option defines a free-form string that can be used to describe @var{fd}.
138 You can open an image using pre-opened file descriptors from an fd set:
141 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
142 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
143 -drive file=/dev/fdset/2,index=0,media=disk
147 DEF("set", HAS_ARG, QEMU_OPTION_set,
148 "-set group.id.arg=value\n"
149 " set <arg> parameter for item <id> of type <group>\n"
150 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
152 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
154 Set parameter @var{arg} for item @var{id} of type @var{group}\n"
157 DEF("global", HAS_ARG, QEMU_OPTION_global,
158 "-global driver.prop=value\n"
159 " set a global default for a driver property\n",
162 @item -global @var{driver}.@var{prop}=@var{value}
164 Set default value of @var{driver}'s property @
var{prop
} to @
var{value
}, e
.g
.:
167 qemu
-system
-i386
-global ide
-drive
.physical_block_size
=4096 -drive file
=file
,if=ide
,index
=0,media
=disk
170 In particular
, you can use
this to set driver properties
for devices which are
171 created automatically by the machine model
. To create a device which is not
172 created automatically and set properties on it
, use
-@option
{device
}.
175 DEF("boot", HAS_ARG
, QEMU_OPTION_boot
,
176 "-boot [order=drives][,once=drives][,menu=on|off]\n"
177 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
178 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
179 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
180 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
181 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
184 @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
]
186 Specify boot order @
var{drives
} as a string of drive letters
. Valid
187 drive letters depend on the target achitecture
. The x86 PC uses
: a
, b
188 (floppy
1 and
2), c (first hard disk
), d (first CD
-ROM
), n
-p (Etherboot
189 from network adapter
1-4), hard disk boot is the
default. To apply a
190 particular boot order only on the first startup
, specify it via
193 Interactive boot menus
/prompts can be enabled via @option
{menu
=on
} as far
194 as firmware
/BIOS supports them
. The
default is non
-interactive boot
.
196 A splash picture could be passed to bios
, enabling user to show it as logo
,
197 when option splash
=@
var{sp_name
} is given and menu
=on
, If firmware
/BIOS
198 supports them
. Currently Seabios
for X86 system support it
.
199 limitation
: The splash file could be a jpeg file or a BMP file
in 24 BPP
200 format(true color
). The resolution should be supported by the SVGA mode
, so
201 the recommended is
320x240
, 640x480
, 800x640
.
203 A timeout could be passed to bios
, guest will pause
for @
var{rb_timeout
} ms
204 when boot failed
, then reboot
. If @
var{rb_timeout
} is
'-1', guest will not
205 reboot
, qemu passes
'-1' to bios by
default. Currently Seabios
for X86
208 Do strict boot via @option
{strict
=on
} as far as firmware
/BIOS
209 supports it
. This only effects when boot priority is changed by
210 bootindex options
. The
default is non
-strict boot
.
213 #
try to boot from network first
, then from hard disk
214 qemu
-system
-i386
-boot order
=nc
215 # boot from CD
-ROM first
, switch back to
default order after reboot
216 qemu
-system
-i386
-boot once
=d
217 # boot with a splash picture
for 5 seconds
.
218 qemu
-system
-i386
-boot menu
=on
,splash
=/root
/boot
.bmp
,splash
-time
=5000
221 Note
: The legacy format
'-boot @var{drives}' is still supported but its
222 use is discouraged as it may be removed from future versions
.
225 DEF("m", HAS_ARG
, QEMU_OPTION_m
,
226 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
227 " configure guest RAM\n"
228 " size: initial amount of guest memory (default: "
229 stringify(DEFAULT_RAM_SIZE
) "MiB)\n"
230 " slots: number of hotplug slots (default: none)\n"
231 " maxmem: maximum amount of guest memory (default: none)\n",
234 @item
-m
[size
=]@
var{megs
}
236 Set virtual RAM size to @
var{megs
} megabytes
. Default is
128 MiB
. Optionally
,
237 a suffix of ``M
'' or ``G
'' can be used to signify a value
in megabytes or
238 gigabytes respectively
. Optional pair @
var{slots
}, @
var{maxmem
} could be used
239 to set amount of hotluggable memory slots and possible maximum amount of memory
.
242 DEF("mem-path", HAS_ARG
, QEMU_OPTION_mempath
,
243 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL
)
245 @item
-mem
-path @
var{path
}
247 Allocate guest RAM from a temporarily created file
in @
var{path
}.
250 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc
,
251 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
255 @findex
-mem
-prealloc
256 Preallocate memory when
using -mem
-path
.
259 DEF("k", HAS_ARG
, QEMU_OPTION_k
,
260 "-k language use keyboard layout (for example 'fr' for French)\n",
263 @item
-k @
var{language
}
265 Use keyboard layout @
var{language
} (for example @code
{fr
} for
266 French
). This option is only needed where it is not easy to get raw PC
267 keycodes (e
.g
. on Macs
, with some X11 servers or with a VNC
268 display
). You don
't normally need to use it on PC/Linux or PC/Windows
271 The available layouts are:
273 ar de-ch es fo fr-ca hu ja mk no pt-br sv
274 da en-gb et fr fr-ch is lt nl pl ru th
275 de en-us fi fr-be hr it lv nl-be pt sl tr
278 The default is @code{en-us}.
282 DEF("audio-help", 0, QEMU_OPTION_audio_help,
283 "-audio-help print list of audio drivers and their options\n",
288 Will show the audio subsystem help: list of drivers, tunable
292 DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
293 "-soundhw c1,... enable audio support\n"
294 " and only specified sound cards (comma separated list)\n"
295 " use '-soundhw help
' to get the list of supported cards\n"
296 " use '-soundhw all
' to enable all of them\n", QEMU_ARCH_ALL)
298 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
300 Enable audio and selected sound hardware. Use 'help
' to print all
301 available sound hardware.
304 qemu-system-i386 -soundhw sb16,adlib disk.img
305 qemu-system-i386 -soundhw es1370 disk.img
306 qemu-system-i386 -soundhw ac97 disk.img
307 qemu-system-i386 -soundhw hda disk.img
308 qemu-system-i386 -soundhw all disk.img
309 qemu-system-i386 -soundhw help
312 Note that Linux's i810_audio OSS
kernel (for AC97
) module might
313 require manually specifying clocking
.
316 modprobe i810_audio clocking
=48000
320 DEF("balloon", HAS_ARG
, QEMU_OPTION_balloon
,
321 "-balloon none disable balloon device\n"
322 "-balloon virtio[,addr=str]\n"
323 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL
)
327 Disable balloon device
.
328 @item
-balloon virtio
[,addr
=@
var{addr
}]
329 Enable virtio balloon
device (default), optionally with PCI address
333 DEF("device", HAS_ARG
, QEMU_OPTION_device
,
334 "-device driver[,prop[=value][,...]]\n"
335 " add device (based on driver)\n"
336 " prop=value,... sets driver properties\n"
337 " use '-device help' to print all possible drivers\n"
338 " use '-device driver,help' to print all possible properties\n",
341 @item
-device @
var{driver
}[,@
var{prop
}[=@
var{value
}][,...]]
343 Add device @
var{driver
}. @
var{prop
}=@
var{value
} sets driver
344 properties
. Valid properties depend on the driver
. To get help on
345 possible drivers and properties
, use @code
{-device help
} and
346 @code
{-device @
var{driver
},help
}.
349 DEF("name", HAS_ARG
, QEMU_OPTION_name
,
350 "-name string1[,process=string2][,debug-threads=on|off]\n"
351 " set the name of the guest\n"
352 " string1 sets the window title and string2 the process name (on Linux)\n"
353 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
354 " NOTE: The thread names are for debugging and not a stable API.\n",
357 @item
-name @
var{name
}
359 Sets the @
var{name
} of the guest
.
360 This name will be displayed
in the SDL window caption
.
361 The @
var{name
} will also be used
for the VNC server
.
362 Also optionally set the top visible process name
in Linux
.
363 Naming of individual threads can also be enabled on Linux to aid debugging
.
366 DEF("uuid", HAS_ARG
, QEMU_OPTION_uuid
,
367 "-uuid %08x-%04x-%04x-%04x-%012x\n"
368 " specify machine UUID\n", QEMU_ARCH_ALL
)
370 @item
-uuid @
var{uuid
}
380 DEFHEADING(Block device options
:)
385 DEF("fda", HAS_ARG
, QEMU_OPTION_fda
,
386 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL
)
387 DEF("fdb", HAS_ARG
, QEMU_OPTION_fdb
, "", QEMU_ARCH_ALL
)
389 @item
-fda @
var{file
}
390 @item
-fdb @
var{file
}
393 Use @
var{file
} as floppy disk
0/1 image (@pxref
{disk_images
}). You can
394 use the host floppy by
using @file
{/dev
/fd0
} as
filename (@pxref
{host_drives
}).
397 DEF("hda", HAS_ARG
, QEMU_OPTION_hda
,
398 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL
)
399 DEF("hdb", HAS_ARG
, QEMU_OPTION_hdb
, "", QEMU_ARCH_ALL
)
400 DEF("hdc", HAS_ARG
, QEMU_OPTION_hdc
,
401 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL
)
402 DEF("hdd", HAS_ARG
, QEMU_OPTION_hdd
, "", QEMU_ARCH_ALL
)
404 @item
-hda @
var{file
}
405 @item
-hdb @
var{file
}
406 @item
-hdc @
var{file
}
407 @item
-hdd @
var{file
}
412 Use @
var{file
} as hard disk
0, 1, 2 or
3 image (@pxref
{disk_images
}).
415 DEF("cdrom", HAS_ARG
, QEMU_OPTION_cdrom
,
416 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
419 @item
-cdrom @
var{file
}
421 Use @
var{file
} as CD
-ROM
image (you cannot use @option
{-hdc
} and
422 @option
{-cdrom
} at the same time
). You can use the host CD
-ROM by
423 using @file
{/dev
/cdrom
} as
filename (@pxref
{host_drives
}).
426 DEF("drive", HAS_ARG
, QEMU_OPTION_drive
,
427 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
428 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
429 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
430 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
431 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
432 " [,readonly=on|off][,copy-on-read=on|off]\n"
433 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
434 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
435 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
436 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
437 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
438 " [[,iops_size=is]]\n"
439 " use 'file' as a drive image\n", QEMU_ARCH_ALL
)
441 @item
-drive @
var{option
}[,@
var{option
}[,@
var{option
}[,...]]]
444 Define a
new drive
. Valid options are
:
447 @item file
=@
var{file
}
448 This option defines which disk
image (@pxref
{disk_images
}) to use with
449 this drive
. If the filename contains comma
, you must double it
450 (for instance
, "file=my,,file" to use file
"my,file").
452 Special files such as iSCSI devices can be specified
using protocol
453 specific URLs
. See the section
for "Device URL Syntax" for more information
.
454 @item
if=@
var{interface}
455 This option defines on which type on
interface the drive is connected
.
456 Available types are
: ide
, scsi
, sd
, mtd
, floppy
, pflash
, virtio
.
457 @item bus
=@
var{bus
},unit
=@
var{unit
}
458 These options define where is connected the drive by defining the bus number and
460 @item index
=@
var{index
}
461 This option defines where is connected the drive by
using an index
in the list
462 of available connectors of a given
interface type
.
463 @item media
=@
var{media
}
464 This option defines the type of the media
: disk or cdrom
.
465 @item cyls
=@
var{c
},heads
=@
var{h
},secs
=@
var{s
}[,trans
=@
var{t
}]
466 These options have the same definition as they have
in @option
{-hdachs
}.
467 @item snapshot
=@
var{snapshot
}
468 @
var{snapshot
} is
"on" or
"off" and controls snapshot mode
for the given drive
469 (see @option
{-snapshot
}).
470 @item cache
=@
var{cache
}
471 @
var{cache
} is
"none", "writeback", "unsafe", "directsync" or
"writethrough" and controls how the host cache is used to access block data
.
473 @
var{aio
} is
"threads", or
"native" and selects between pthread based disk I
/O and native Linux AIO
.
474 @item discard
=@
var{discard
}
475 @
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
.
476 @item format
=@
var{format
}
477 Specify which disk @
var{format
} will be used rather than detecting
478 the format
. Can be used to specifiy format
=raw to avoid interpreting
479 an untrusted format header
.
480 @item serial
=@
var{serial
}
481 This option specifies the serial number to assign to the device
.
482 @item addr
=@
var{addr
}
483 Specify the controller
's PCI address (if=virtio only).
484 @item werror=@var{action},rerror=@var{action}
485 Specify which @var{action} to take on write and read errors. Valid actions are:
486 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
487 "report" (report the error to the guest), "enospc" (pause QEMU only if the
488 host disk is full; report the error to the guest otherwise).
489 The default setting is @option{werror=enospc} and @option{rerror=report}.
491 Open drive @option{file} as read-only. Guest write attempts will fail.
492 @item copy-on-read=@var{copy-on-read}
493 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
494 file sectors into the image file.
495 @item detect-zeroes=@var{detect-zeroes}
496 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
497 conversion of plain zero writes by the OS to driver specific optimized
498 zero write commands. You may even choose "unmap" if @var{discard} is set
499 to "unmap" to allow a zero write to be converted to an UNMAP operation.
502 By default, the @option{cache=writeback} mode is used. It will report data
503 writes as completed as soon as the data is present in the host page cache.
504 This is safe as long as your guest OS makes sure to correctly flush disk caches
505 where needed. If your guest OS does not handle volatile disk write caches
506 correctly and your host crashes or loses power, then the guest may experience
509 For such guests, you should consider using @option{cache=writethrough}. This
510 means that the host page cache will be used to read and write data, but write
511 notification will be sent to the guest only after QEMU has made sure to flush
512 each write to the disk. Be aware that this has a major impact on performance.
514 The host page cache can be avoided entirely with @option{cache=none}. This will
515 attempt to do disk IO directly to the guest's memory
. QEMU may still perform
516 an internal copy of the data
. Note that
this is considered a writeback mode and
517 the guest OS must handle the disk write cache correctly
in order to avoid data
518 corruption on host crashes
.
520 The host page cache can be avoided
while only sending write notifications to
521 the guest when the data has been flushed to the disk
using
522 @option
{cache
=directsync
}.
524 In
case you don
't care about data integrity over host failures, use
525 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
526 data to the disk but can instead keep things in cache. If anything goes wrong,
527 like your host losing power, the disk storage getting disconnected accidentally,
528 etc. your image will most probably be rendered unusable. When using
529 the @option{-snapshot} option, unsafe caching is always used.
531 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
532 useful when the backing file is over a slow network. By default copy-on-read
535 Instead of @option{-cdrom} you can use:
537 qemu-system-i386 -drive file=file,index=2,media=cdrom
540 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
543 qemu-system-i386 -drive file=file,index=0,media=disk
544 qemu-system-i386 -drive file=file,index=1,media=disk
545 qemu-system-i386 -drive file=file,index=2,media=disk
546 qemu-system-i386 -drive file=file,index=3,media=disk
549 You can open an image using pre-opened file descriptors from an fd set:
552 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
553 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
554 -drive file=/dev/fdset/2,index=0,media=disk
557 You can connect a CDROM to the slave of ide0:
559 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
562 If you don't specify the
"file=" argument
, you define an empty drive
:
564 qemu
-system
-i386
-drive
if=ide
,index
=1,media
=cdrom
567 You can connect a SCSI disk with unit ID
6 on the bus #
0:
569 qemu
-system
-i386
-drive file
=file
,if=scsi
,bus
=0,unit
=6
572 Instead of @option
{-fda
}, @option
{-fdb
}, you can use
:
574 qemu
-system
-i386
-drive file
=file
,index
=0,if=floppy
575 qemu
-system
-i386
-drive file
=file
,index
=1,if=floppy
578 By
default, @
var{interface} is
"ide" and @
var{index
} is automatically
581 qemu
-system
-i386
-drive file
=a
-drive file
=b
"
585 qemu-system-i386 -hda a -hdb b
589 DEF("mtdblock
", HAS_ARG, QEMU_OPTION_mtdblock,
590 "-mtdblock file use
'file' as on
-board Flash memory image
\n",
593 @item -mtdblock @var{file}
595 Use @var{file} as on-board Flash memory image.
598 DEF("sd
", HAS_ARG, QEMU_OPTION_sd,
599 "-sd file use
'file' as SecureDigital card image
\n", QEMU_ARCH_ALL)
603 Use @var{file} as SecureDigital card image.
606 DEF("pflash
", HAS_ARG, QEMU_OPTION_pflash,
607 "-pflash file use
'file' as a parallel flash image
\n", QEMU_ARCH_ALL)
609 @item -pflash @var{file}
611 Use @var{file} as a parallel flash image.
614 DEF("snapshot
", 0, QEMU_OPTION_snapshot,
615 "-snapshot write to temporary files instead of disk image files
\n",
620 Write to temporary files instead of disk image files. In this case,
621 the raw disk image you use is not written back. You can however force
622 the write back by pressing @key{C-a s} (@pxref{disk_images}).
625 DEF("hdachs
", HAS_ARG, QEMU_OPTION_hdachs, \
626 "-hdachs c
,h
,s
[,t
]\n" \
627 " force hard disk
0 physical geometry and the optional BIOS
\n" \
628 " translation (t
=none or lba
) (usually QEMU can guess them
)\n",
631 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
633 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
634 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
635 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
636 all those parameters. This option is useful for old MS-DOS disk
640 DEF("fsdev
", HAS_ARG, QEMU_OPTION_fsdev,
641 "-fsdev fsdriver
,id
=id
[,path
=path
,][security_model
={mapped
-xattr|mapped
-file|passthrough|none
}]\n"
642 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
647 @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}]
649 Define a new file system device. Valid options are:
652 This option specifies the fs driver backend to use.
653 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
655 Specifies identifier for this device
656 @item path=@var{path}
657 Specifies the export path for the file system device. Files under
658 this path will be available to the 9p client on the guest.
659 @item security_model=@var{security_model}
660 Specifies the security model to be used for this export path.
661 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
662 In "passthrough
" security model, files are stored using the same
663 credentials as they are created on the guest. This requires QEMU
664 to run as root. In "mapped
-xattr
" security model, some of the file
665 attributes like uid, gid, mode bits and link target are stored as
666 file attributes. For "mapped
-file
" these attributes are stored in the
667 hidden .virtfs_metadata directory. Directories exported by this security model cannot
668 interact with other unix tools. "none
" security model is same as
669 passthrough except the sever won't report failures if it fails to
670 set file attributes like ownership. Security model is mandatory
671 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
672 security model as a parameter.
673 @item writeout=@var{writeout}
674 This is an optional argument. The only supported value is "immediate
".
675 This means that host page cache will be used to read and write data but
676 write notification will be sent to the guest only when the data has been
677 reported as written by the storage subsystem.
679 Enables exporting 9p share as a readonly mount for guests. By default
680 read-write access is given.
681 @item socket=@var{socket}
682 Enables proxy filesystem driver to use passed socket file for communicating
683 with virtfs-proxy-helper
684 @item sock_fd=@var{sock_fd}
685 Enables proxy filesystem driver to use passed socket descriptor for
686 communicating with virtfs-proxy-helper. Usually a helper like libvirt
687 will create socketpair and pass one of the fds as sock_fd
690 -fsdev option is used along with -device driver "virtio
-9p
-pci
".
691 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
692 Options for virtio-9p-pci driver are:
695 Specifies the id value specified along with -fsdev option
696 @item mount_tag=@var{mount_tag}
697 Specifies the tag name to be used by the guest to mount this export point
702 DEF("virtfs
", HAS_ARG, QEMU_OPTION_virtfs,
703 "-virtfs local
,path
=path
,mount_tag
=tag
,security_model
=[mapped
-xattr|mapped
-file|passthrough|none
]\n"
704 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
709 @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}]
712 The general form of a Virtual File system pass-through options are:
715 This option specifies the fs driver backend to use.
716 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
718 Specifies identifier for this device
719 @item path=@var{path}
720 Specifies the export path for the file system device. Files under
721 this path will be available to the 9p client on the guest.
722 @item security_model=@var{security_model}
723 Specifies the security model to be used for this export path.
724 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
725 In "passthrough
" security model, files are stored using the same
726 credentials as they are created on the guest. This requires QEMU
727 to run as root. In "mapped
-xattr
" security model, some of the file
728 attributes like uid, gid, mode bits and link target are stored as
729 file attributes. For "mapped
-file
" these attributes are stored in the
730 hidden .virtfs_metadata directory. Directories exported by this security model cannot
731 interact with other unix tools. "none
" security model is same as
732 passthrough except the sever won't report failures if it fails to
733 set file attributes like ownership. Security model is mandatory only
734 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
735 model as a parameter.
736 @item writeout=@var{writeout}
737 This is an optional argument. The only supported value is "immediate
".
738 This means that host page cache will be used to read and write data but
739 write notification will be sent to the guest only when the data has been
740 reported as written by the storage subsystem.
742 Enables exporting 9p share as a readonly mount for guests. By default
743 read-write access is given.
744 @item socket=@var{socket}
745 Enables proxy filesystem driver to use passed socket file for
746 communicating with virtfs-proxy-helper. Usually a helper like libvirt
747 will create socketpair and pass one of the fds as sock_fd
749 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
750 descriptor for interfacing with virtfs-proxy-helper
754 DEF("virtfs_synth
", 0, QEMU_OPTION_virtfs_synth,
755 "-virtfs_synth Create synthetic file system image
\n",
759 @findex -virtfs_synth
760 Create synthetic file system image
768 DEFHEADING(USB options:)
773 DEF("usb
", 0, QEMU_OPTION_usb,
774 "-usb enable the USB
driver (will be the
default soon
)\n",
779 Enable the USB driver (will be the default soon)
782 DEF("usbdevice
", HAS_ARG, QEMU_OPTION_usbdevice,
783 "-usbdevice name add the host or guest USB device
'name'\n",
787 @item -usbdevice @var{devname}
789 Add the USB device @var{devname}. @xref{usb_devices}.
794 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
797 Pointer device that uses absolute coordinates (like a touchscreen). This
798 means QEMU is able to report the mouse position without having to grab the
799 mouse. Also overrides the PS/2 mouse emulation when activated.
801 @item disk:[format=@var{format}]:@var{file}
802 Mass storage device based on file. The optional @var{format} argument
803 will be used rather than detecting the format. Can be used to specifiy
804 @code{format=raw} to avoid interpreting an untrusted format header.
806 @item host:@var{bus}.@var{addr}
807 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
809 @item host:@var{vendor_id}:@var{product_id}
810 Pass through the host device identified by @var{vendor_id}:@var{product_id}
813 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
814 Serial converter to host character device @var{dev}, see @code{-serial} for the
818 Braille device. This will use BrlAPI to display the braille output on a real
821 @item net:@var{options}
822 Network adapter that supports CDC ethernet and RNDIS protocols.
832 DEFHEADING(Display options:)
837 DEF("display
", HAS_ARG, QEMU_OPTION_display,
838 "-display sdl
[,frame
=on|off
][,alt_grab
=on|off
][,ctrl_grab
=on|off
]\n"
839 " [,window_close
=on|off
]|curses|none|
\n"
840 " gtk
[,grab_on_hover
=on|off
]|
\n"
841 " vnc
=<display
>[,<optargs
>]\n"
842 " select display type
\n", QEMU_ARCH_ALL)
844 @item -display @var{type}
846 Select type of display to use. This option is a replacement for the
847 old style -sdl/-curses/... options. Valid values for @var{type} are
850 Display video output via SDL (usually in a separate graphics
851 window; see the SDL documentation for other possibilities).
853 Display video output via curses. For graphics device models which
854 support a text mode, QEMU can display this output using a
855 curses/ncurses interface. Nothing is displayed when the graphics
856 device is in graphical mode or if the graphics device does not support
857 a text mode. Generally only the VGA device models support text mode.
859 Do not display video output. The guest will still see an emulated
860 graphics card, but its output will not be displayed to the QEMU
861 user. This option differs from the -nographic option in that it
862 only affects what is done with video output; -nographic also changes
863 the destination of the serial and parallel port data.
865 Display video output in a GTK window. This interface provides drop-down
866 menus and other UI elements to configure and control the VM during
869 Start a VNC server on display <arg>
873 DEF("nographic
", 0, QEMU_OPTION_nographic,
874 "-nographic disable graphical output and redirect serial I
/Os to console
\n",
879 Normally, QEMU uses SDL to display the VGA output. With this option,
880 you can totally disable graphical output so that QEMU is a simple
881 command line application. The emulated serial port is redirected on
882 the console and muxed with the monitor (unless redirected elsewhere
883 explicitly). Therefore, you can still use QEMU to debug a Linux kernel
884 with a serial console. Use @key{C-a h} for help on switching between
885 the console and monitor.
888 DEF("curses
", 0, QEMU_OPTION_curses,
889 "-curses use a curses
/ncurses
interface instead of SDL
\n",
894 Normally, QEMU uses SDL to display the VGA output. With this option,
895 QEMU can display the VGA output when in text mode using a
896 curses/ncurses interface. Nothing is displayed in graphical mode.
899 DEF("no
-frame
", 0, QEMU_OPTION_no_frame,
900 "-no
-frame open SDL window without a frame and window decorations
\n",
905 Do not use decorations for SDL windows and start them using the whole
906 available screen space. This makes the using QEMU in a dedicated desktop
907 workspace more convenient.
910 DEF("alt
-grab
", 0, QEMU_OPTION_alt_grab,
911 "-alt
-grab use Ctrl
-Alt
-Shift to grab
mouse (instead of Ctrl
-Alt
)\n",
916 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
917 affects the special keys (for fullscreen, monitor-mode switching, etc).
920 DEF("ctrl
-grab
", 0, QEMU_OPTION_ctrl_grab,
921 "-ctrl
-grab use Right
-Ctrl to grab
mouse (instead of Ctrl
-Alt
)\n",
926 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
927 affects the special keys (for fullscreen, monitor-mode switching, etc).
930 DEF("no
-quit
", 0, QEMU_OPTION_no_quit,
931 "-no
-quit disable SDL window close capability
\n", QEMU_ARCH_ALL)
935 Disable SDL window close capability.
938 DEF("sdl
", 0, QEMU_OPTION_sdl,
939 "-sdl enable SDL
\n", QEMU_ARCH_ALL)
946 DEF("spice
", HAS_ARG, QEMU_OPTION_spice,
947 "-spice
[port
=port
][,tls
-port
=secured
-port
][,x509
-dir
=<dir
>]\n"
948 " [,x509
-key
-file
=<file
>][,x509
-key
-password
=<file
>]\n"
949 " [,x509
-cert
-file
=<file
>][,x509
-cacert
-file
=<file
>]\n"
950 " [,x509
-dh
-key
-file
=<file
>][,addr
=addr
][,ipv4|ipv6
]\n"
951 " [,tls
-ciphers
=<list
>]\n"
952 " [,tls
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
953 " [,plaintext
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
954 " [,sasl
][,password
=<secret
>][,disable
-ticketing
]\n"
955 " [,image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]]\n"
956 " [,jpeg
-wan
-compression
=[auto|
never|always
]]\n"
957 " [,zlib
-glz
-wan
-compression
=[auto|
never|always
]]\n"
958 " [,streaming
-video
=[off|all|filter
]][,disable
-copy
-paste
]\n"
959 " [,disable
-agent
-file
-xfer
][,agent
-mouse
=[on|off
]]\n"
960 " [,playback
-compression
=[on|off
]][,seamless
-migration
=[on|off
]]\n"
962 " at least one of
{port
, tls
-port
} is mandatory
\n",
965 @item -spice @var{option}[,@var{option}[,...]]
967 Enable the spice remote desktop protocol. Valid options are
972 Set the TCP port spice is listening on for plaintext channels.
975 Set the IP address spice is listening on. Default is any address.
979 Force using the specified IP version.
981 @item password=<secret>
982 Set the password you need to authenticate.
985 Require that the client use SASL to authenticate with the spice.
986 The exact choice of authentication method used is controlled from the
987 system / user's SASL configuration file for the 'qemu' service. This
988 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
989 unprivileged user, an environment variable SASL_CONF_PATH can be used
990 to make it search alternate locations for the service config.
991 While some SASL auth methods can also provide data encryption (eg GSSAPI),
992 it is recommended that SASL always be combined with the 'tls' and
993 'x509' settings to enable use of SSL and server certificates. This
994 ensures a data encryption preventing compromise of authentication
997 @item disable-ticketing
998 Allow client connects without authentication.
1000 @item disable-copy-paste
1001 Disable copy paste between the client and the guest.
1003 @item disable-agent-file-xfer
1004 Disable spice-vdagent based file-xfer between the client and the guest.
1007 Set the TCP port spice is listening on for encrypted channels.
1009 @item x509-dir=<dir>
1010 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1012 @item x509-key-file=<file>
1013 @item x509-key-password=<file>
1014 @item x509-cert-file=<file>
1015 @item x509-cacert-file=<file>
1016 @item x509-dh-key-file=<file>
1017 The x509 file names can also be configured individually.
1019 @item tls-ciphers=<list>
1020 Specify which ciphers to use.
1022 @item tls-channel=[main|display|cursor|inputs|record|playback]
1023 @item plaintext-channel=[main|display|cursor|inputs|record|playback]
1024 Force specific channel to be used with or without TLS encryption. The
1025 options can be specified multiple times to configure multiple
1026 channels. The special name "default" can be used to set the default
1027 mode. For channels which are not explicitly forced into one mode the
1028 spice client is allowed to pick tls/plaintext as he pleases.
1030 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1031 Configure image compression (lossless).
1032 Default is auto_glz.
1034 @item jpeg-wan-compression=[auto|never|always]
1035 @item zlib-glz-wan-compression=[auto|never|always]
1036 Configure wan image compression (lossy for slow links).
1039 @item streaming-video=[off|all|filter]
1040 Configure video stream detection. Default is filter.
1042 @item agent-mouse=[on|off]
1043 Enable/disable passing mouse events via vdagent. Default is on.
1045 @item playback-compression=[on|off]
1046 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1048 @item seamless-migration=[on|off]
1049 Enable/disable spice seamless migration. Default is off.
1054 DEF("portrait
", 0, QEMU_OPTION_portrait,
1055 "-portrait rotate graphical output
90 deg
left (only PXA LCD
)\n",
1060 Rotate graphical output 90 deg left (only PXA LCD).
1063 DEF("rotate
", HAS_ARG, QEMU_OPTION_rotate,
1064 "-rotate
<deg
> rotate graphical output some deg
left (only PXA LCD
)\n",
1067 @item -rotate @var{deg}
1069 Rotate graphical output some deg left (only PXA LCD).
1072 DEF("vga
", HAS_ARG, QEMU_OPTION_vga,
1073 "-vga
[std|cirrus|vmware|qxl|xenfb|tcx|cg3|none
]\n"
1074 " select video card type
\n", QEMU_ARCH_ALL)
1076 @item -vga @var{type}
1078 Select type of VGA card to emulate. Valid values for @var{type} are
1081 Cirrus Logic GD5446 Video card. All Windows versions starting from
1082 Windows 95 should recognize and use this graphic card. For optimal
1083 performances, use 16 bit color depth in the guest and the host OS.
1084 (This one is the default)
1086 Standard VGA card with Bochs VBE extensions. If your guest OS
1087 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1088 to use high resolution modes (>= 1280x1024x16) then you should use
1091 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1092 recent XFree86/XOrg server or Windows guest with a driver for this
1095 QXL paravirtual graphic card. It is VGA compatible (including VESA
1096 2.0 VBE support). Works best with qxl guest drivers installed though.
1097 Recommended choice when using the spice protocol.
1099 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1100 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1101 fixed resolution of 1024x768.
1103 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1104 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1105 resolutions aimed at people wishing to run older Solaris versions.
1111 DEF("full
-screen
", 0, QEMU_OPTION_full_screen,
1112 "-full
-screen start
in full screen
\n", QEMU_ARCH_ALL)
1115 @findex -full-screen
1116 Start in full screen.
1119 DEF("g
", 1, QEMU_OPTION_g ,
1120 "-g WxH
[xDEPTH
] Set the initial graphical resolution and depth
\n",
1121 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1123 @item -g @var{width}x@var{height}[x@var{depth}]
1125 Set the initial graphical resolution and depth (PPC, SPARC only).
1128 DEF("vnc
", HAS_ARG, QEMU_OPTION_vnc ,
1129 "-vnc display start a VNC server on display
\n", QEMU_ARCH_ALL)
1131 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1133 Normally, QEMU uses SDL to display the VGA output. With this option,
1134 you can have QEMU listen on VNC display @var{display} and redirect the VGA
1135 display over the VNC session. It is very useful to enable the usb
1136 tablet device when using this option (option @option{-usbdevice
1137 tablet}). When using the VNC display, you must use the @option{-k}
1138 parameter to set the keyboard layout if you are not using en-us. Valid
1139 syntax for the @var{display} is
1143 @item @var{host}:@var{d}
1145 TCP connections will only be allowed from @var{host} on display @var{d}.
1146 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1147 be omitted in which case the server will accept connections from any host.
1149 @item unix:@var{path}
1151 Connections will be allowed over UNIX domain sockets where @var{path} is the
1152 location of a unix socket to listen for connections on.
1156 VNC is initialized but not started. The monitor @code{change} command
1157 can be used to later start the VNC server.
1161 Following the @var{display} value there may be one or more @var{option} flags
1162 separated by commas. Valid options are
1168 Connect to a listening VNC client via a ``reverse'' connection. The
1169 client is specified by the @var{display}. For reverse network
1170 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1171 is a TCP port number, not a display number.
1175 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1176 By definition the Websocket port is 5700+@var{display}. If @var{host} is
1177 specified connections will only be allowed from this host.
1178 As an alternative the Websocket port could be specified by using
1179 @code{websocket}=@var{port}.
1180 TLS encryption for the Websocket connection is supported if the required
1181 certificates are specified with the VNC option @option{x509}.
1185 Require that password based authentication is used for client connections.
1187 The password must be set separately using the @code{set_password} command in
1188 the @ref{pcsys_monitor}. The syntax to change your password is:
1189 @code{set_password <protocol> <password>} where <protocol> could be either
1192 If you would like to change <protocol> password expiration, you should use
1193 @code{expire_password <protocol> <expiration-time>} where expiration time could
1194 be one of the following options: now, never, +seconds or UNIX time of
1195 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1196 to make password expire on "Mon Apr
23 12:00:00 EDT
2012" (UNIX time for this
1199 You can also use keywords "now
" or "never" for the expiration time to
1200 allow <protocol> password to expire immediately or never expire.
1204 Require that client use TLS when communicating with the VNC server. This
1205 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1206 attack. It is recommended that this option be combined with either the
1207 @option{x509} or @option{x509verify} options.
1209 @item x509=@var{/path/to/certificate/dir}
1211 Valid if @option{tls} is specified. Require that x509 credentials are used
1212 for negotiating the TLS session. The server will send its x509 certificate
1213 to the client. It is recommended that a password be set on the VNC server
1214 to provide authentication of the client when this is used. The path following
1215 this option specifies where the x509 certificates are to be loaded from.
1216 See the @ref{vnc_security} section for details on generating certificates.
1218 @item x509verify=@var{/path/to/certificate/dir}
1220 Valid if @option{tls} is specified. Require that x509 credentials are used
1221 for negotiating the TLS session. The server will send its x509 certificate
1222 to the client, and request that the client send its own x509 certificate.
1223 The server will validate the client's certificate against the CA certificate,
1224 and reject clients when validation fails. If the certificate authority is
1225 trusted, this is a sufficient authentication mechanism. You may still wish
1226 to set a password on the VNC server as a second authentication layer. The
1227 path following this option specifies where the x509 certificates are to
1228 be loaded from. See the @ref{vnc_security} section for details on generating
1233 Require that the client use SASL to authenticate with the VNC server.
1234 The exact choice of authentication method used is controlled from the
1235 system / user's SASL configuration file for the 'qemu' service. This
1236 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1237 unprivileged user, an environment variable SASL_CONF_PATH can be used
1238 to make it search alternate locations for the service config.
1239 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1240 it is recommended that SASL always be combined with the 'tls' and
1241 'x509' settings to enable use of SSL and server certificates. This
1242 ensures a data encryption preventing compromise of authentication
1243 credentials. See the @ref{vnc_security} section for details on using
1244 SASL authentication.
1248 Turn on access control lists for checking of the x509 client certificate
1249 and SASL party. For x509 certs, the ACL check is made against the
1250 certificate's distinguished name. This is something that looks like
1251 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1252 made against the username, which depending on the SASL plugin, may
1253 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1254 When the @option{acl} flag is set, the initial access list will be
1255 empty, with a @code{deny} policy. Thus no one will be allowed to
1256 use the VNC server until the ACLs have been loaded. This can be
1257 achieved using the @code{acl} monitor command.
1261 Enable lossy compression methods (gradient, JPEG, ...). If this
1262 option is set, VNC client may receive lossy framebuffer updates
1263 depending on its encoding settings. Enabling this option can save
1264 a lot of bandwidth at the expense of quality.
1268 Disable adaptive encodings. Adaptive encodings are enabled by default.
1269 An adaptive encoding will try to detect frequently updated screen regions,
1270 and send updates in these regions using a lossy encoding (like JPEG).
1271 This can be really helpful to save bandwidth when playing videos. Disabling
1272 adaptive encodings restores the original static behavior of encodings
1275 @item share=[allow-exclusive|force-shared|ignore]
1277 Set display sharing policy. 'allow-exclusive' allows clients to ask
1278 for exclusive access. As suggested by the rfb spec this is
1279 implemented by dropping other connections. Connecting multiple
1280 clients in parallel requires all clients asking for a shared session
1281 (vncviewer: -shared switch). This is the default. 'force-shared'
1282 disables exclusive client access. Useful for shared desktop sessions,
1283 where you don't want someone forgetting specify -shared disconnect
1284 everybody else. 'ignore' completely ignores the shared flag and
1285 allows everybody connect unconditionally. Doesn't conform to the rfb
1286 spec but is traditional QEMU behavior.
1294 ARCHHEADING(, QEMU_ARCH_I386)
1296 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1301 DEF("win2k
-hack
", 0, QEMU_OPTION_win2k_hack,
1302 "-win2k
-hack use it when installing Windows
2000 to avoid a disk full bug
\n",
1307 Use it when installing Windows 2000 to avoid a disk full bug. After
1308 Windows 2000 is installed, you no longer need this option (this option
1309 slows down the IDE transfers).
1312 HXCOMM Deprecated by -rtc
1313 DEF("rtc
-td
-hack
", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1315 DEF("no
-fd
-bootchk
", 0, QEMU_OPTION_no_fd_bootchk,
1316 "-no
-fd
-bootchk disable boot signature checking
for floppy disks
\n",
1319 @item -no-fd-bootchk
1320 @findex -no-fd-bootchk
1321 Disable boot signature checking for floppy disks in BIOS. May
1322 be needed to boot from old floppy disks.
1325 DEF("no
-acpi
", 0, QEMU_OPTION_no_acpi,
1326 "-no
-acpi disable ACPI
\n", QEMU_ARCH_I386)
1330 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1331 it if your guest OS complains about ACPI problems (PC target machine
1335 DEF("no
-hpet
", 0, QEMU_OPTION_no_hpet,
1336 "-no
-hpet disable HPET
\n", QEMU_ARCH_I386)
1340 Disable HPET support.
1343 DEF("acpitable
", HAS_ARG, QEMU_OPTION_acpitable,
1344 "-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"
1345 " ACPI table description
\n", QEMU_ARCH_I386)
1347 @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}]...]
1349 Add ACPI table with specified header fields and context from specified files.
1350 For file=, take whole ACPI table from the specified files, including all
1351 ACPI headers (possible overridden by other options).
1352 For data=, only data
1353 portion of the table is used, all header information is specified in the
1357 DEF("smbios
", HAS_ARG, QEMU_OPTION_smbios,
1358 "-smbios file
=binary
\n"
1359 " load SMBIOS entry from binary file
\n"
1360 "-smbios type
=0[,vendor
=str
][,version
=str
][,date
=str
][,release
=%d
.%d
][,uefi
=on|off
]\n"
1361 " specify SMBIOS type
0 fields
\n"
1362 "-smbios type
=1[,manufacturer
=str
][,product
=str
][,version
=str
][,serial
=str
]\n"
1363 " [,uuid
=uuid
][,sku
=str
][,family
=str
]\n"
1364 " specify SMBIOS type
1 fields
\n", QEMU_ARCH_I386)
1366 @item -smbios file=@var{binary}
1368 Load SMBIOS entry from binary file.
1370 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1371 Specify SMBIOS type 0 fields
1373 @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}]
1374 Specify SMBIOS type 1 fields
1382 DEFHEADING(Network options:)
1387 HXCOMM Legacy slirp options (now moved to -net user):
1389 DEF("tftp
", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1390 DEF("bootp
", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1391 DEF("redir
", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1393 DEF("smb
", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1397 DEF("net
", HAS_ARG, QEMU_OPTION_net,
1398 "-net nic
[,vlan
=n
][,macaddr
=mac
][,model
=type
][,name
=str
][,addr
=str
][,vectors
=v
]\n"
1399 " create a
new Network Interface Card and connect it to VLAN
'n'\n"
1401 "-net user
[,vlan
=n
][,name
=str
][,net
=addr
[/mask
]][,host
=addr
][,restrict
=on|off
]\n"
1402 " [,hostname
=host
][,dhcpstart
=addr
][,dns
=addr
][,dnssearch
=domain
][,tftp
=dir
]\n"
1403 " [,bootfile
=f
][,hostfwd
=rule
][,guestfwd
=rule
]"
1405 "[,smb
=dir
[,smbserver
=addr
]]\n"
1407 " connect the user mode network stack to VLAN
'n', configure its
\n"
1408 " DHCP server and enabled optional services
\n"
1411 "-net tap
[,vlan
=n
][,name
=str
],ifname
=name
\n"
1412 " connect the host TAP network
interface to VLAN
'n'\n"
1414 "-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"
1415 " connect the host TAP network
interface to VLAN
'n'\n"
1416 " use network scripts
'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1417 " to configure it and
'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1418 " to deconfigure it
\n"
1419 " use
'[down]script=no' to disable script execution
\n"
1420 " use network helper
'helper' (default=" DEFAULT_BRIDGE_HELPER ") to
\n"
1422 " use
'fd=h' to connect to an already opened TAP
interface\n"
1423 " use
'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces
\n"
1424 " use
'sndbuf=nbytes' to limit the size of the send
buffer (the
\n"
1425 " default is disabled
'sndbuf=0' to enable flow control set
'sndbuf=1048576')\n"
1426 " use vnet_hdr
=off to avoid enabling the IFF_VNET_HDR tap flag
\n"
1427 " use vnet_hdr
=on to make the lack of IFF_VNET_HDR support an error condition
\n"
1428 " use vhost
=on to enable experimental
in kernel accelerator
\n"
1429 " (only has effect
for virtio guests which use MSIX
)\n"
1430 " use vhostforce
=on to force vhost on
for non
-MSIX virtio guests
\n"
1431 " use
'vhostfd=h' to connect to an already opened vhost net device
\n"
1432 " use
'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1433 " use 'queues
=n
' to specify the number of queues to be created for multiqueue TAP\n"
1434 "-net bridge[,vlan=n][,name=str][,br=bridge][,helper=helper]\n"
1435 " connects a host TAP network interface to a host bridge device 'br
'\n"
1436 " (default=" DEFAULT_BRIDGE_INTERFACE ") using the program 'helper
'\n"
1437 " (default=" DEFAULT_BRIDGE_HELPER ")\n"
1440 "-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"
1441 " connect the VLAN to an Ethernet over L2TPv3 pseudowire\n"
1442 " Linux kernel 3.3+ as well as most routers can talk\n"
1443 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1444 " VM to a router and even VM to Host. It is a nearly-universal\n"
1445 " standard (RFC3391). Note - this implementation uses static\n"
1446 " pre-configured tunnels (same as the Linux kernel).\n"
1447 " use 'src
=' to specify source address\n"
1448 " use 'dst
=' to specify destination address\n"
1449 " use 'udp
=on
' to specify udp encapsulation\n"
1450 " use 'srcport
=' to specify source udp port\n"
1451 " use 'dstport
=' to specify destination udp port\n"
1452 " use 'ipv6
=on
' to force v6\n"
1453 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1454 " well as a weak security measure\n"
1455 " use 'rxcookie
=0x012345678' to specify a rxcookie\n"
1456 " use 'txcookie
=0x012345678' to specify a txcookie\n"
1457 " use 'cookie64
=on
' to set cookie size to 64 bit, otherwise 32\n"
1458 " use 'counter
=off
' to force a 'cut
-down
' L2TPv3 with no counter\n"
1459 " use 'pincounter
=on
' to work around broken counter handling in peer\n"
1460 " use 'offset
=X
' to add an extra offset between header and data\n"
1462 "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
1463 " connect the vlan 'n
' to another VLAN using a socket connection\n"
1464 "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1465 " connect the vlan 'n
' to multicast maddr and port\n"
1466 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1467 "-net socket[,vlan=n][,name=str][,fd=h][,udp=host:port][,localaddr=host:port]\n"
1468 " connect the vlan 'n
' to another VLAN using an UDP tunnel\n"
1470 "-net vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1471 " connect the vlan 'n
' to port 'n
' of a vde switch running\n"
1472 " on host and listening for incoming connections on 'socketpath
'.\n"
1473 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1474 " ownership and permissions for communication port.\n"
1476 #ifdef CONFIG_NETMAP
1477 "-net netmap,ifname=name[,devname=nmname]\n"
1478 " attach to the existing netmap-enabled network interface 'name
', or to a\n"
1479 " VALE port (created on the fly) called 'name
' ('nmname
' is name of the \n"
1480 " netmap device, defaults to '/dev
/netmap
')\n"
1482 "-net dump[,vlan=n][,file=f][,len=n]\n"
1483 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
1484 "-net none use it alone to have zero network devices. If no -net option\n"
1485 " is provided, the default is '-net nic
-net user
'\n", QEMU_ARCH_ALL)
1486 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1496 #ifdef CONFIG_NETMAP
1501 "hubport],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
1503 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1505 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1506 = 0 is the default). The NIC is an e1000 by default on the PC
1507 target. Optionally, the MAC address can be changed to @var{mac}, the
1508 device address set to @var{addr} (PCI cards only),
1509 and a @var{name} can be assigned for use in monitor commands.
1510 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1511 that the card should have; this option currently only affects virtio cards; set
1512 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1513 NIC is created. QEMU can emulate several different models of network card.
1514 Valid values for @var{type} are
1515 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1516 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1517 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1518 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1519 for a list of available devices for your target.
1521 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1523 @item -net user[,@var{option}][,@var{option}][,...]
1524 Use the user mode network stack which requires no administrator
1525 privilege to run. Valid options are:
1529 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1532 @item name=@var{name}
1533 Assign symbolic name for use in monitor commands.
1535 @item net=@var{addr}[/@var{mask}]
1536 Set IP network address the guest will see. Optionally specify the netmask,
1537 either in the form a.b.c.d or as number of valid top-most bits. Default is
1540 @item host=@var{addr}
1541 Specify the guest-visible address of the host. Default is the 2nd IP in the
1542 guest network, i.e. x.x.x.2.
1544 @item restrict=on|off
1545 If this option is enabled, the guest will be isolated, i.e. it will not be
1546 able to contact the host and no guest IP packets will be routed over the host
1547 to the outside. This option does not affect any explicitly set forwarding rules.
1549 @item hostname=@var{name}
1550 Specifies the client hostname reported by the built-in DHCP server.
1552 @item dhcpstart=@var{addr}
1553 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1554 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1556 @item dns=@var{addr}
1557 Specify the guest-visible address of the virtual nameserver. The address must
1558 be different from the host address. Default is the 3rd IP in the guest network,
1561 @item dnssearch=@var{domain}
1562 Provides an entry for the domain-search list sent by the built-in
1563 DHCP server. More than one domain suffix can be transmitted by specifying
1564 this option multiple times. If supported, this will cause the guest to
1565 automatically try to append the given domain suffix(es) in case a domain name
1566 can not be resolved.
1570 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1573 @item tftp=@var{dir}
1574 When using the user mode network stack, activate a built-in TFTP
1575 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1576 The TFTP client on the guest must be configured in binary mode (use the command
1577 @code{bin} of the Unix TFTP client).
1579 @item bootfile=@var{file}
1580 When using the user mode network stack, broadcast @var{file} as the BOOTP
1581 filename. In conjunction with @option{tftp}, this can be used to network boot
1582 a guest from a local directory.
1584 Example (using pxelinux):
1586 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1589 @item smb=@var{dir}[,smbserver=@var{addr}]
1590 When using the user mode network stack, activate a built-in SMB
1591 server so that Windows OSes can access to the host files in @file{@var{dir}}
1592 transparently. The IP address of the SMB server can be set to @var{addr}. By
1593 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1595 In the guest Windows OS, the line:
1599 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1600 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1602 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1604 Note that a SAMBA server must be installed on the host OS.
1605 QEMU was tested successfully with smbd versions from Red Hat 9,
1606 Fedora Core 3 and OpenSUSE 11.x.
1608 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1609 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1610 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1611 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1612 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1613 be bound to a specific host interface. If no connection type is set, TCP is
1614 used. This option can be given multiple times.
1616 For example, to redirect host X11 connection from screen 1 to guest
1617 screen 0, use the following:
1621 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1622 # this host xterm should open in the guest X11 server
1626 To redirect telnet connections from host port 5555 to telnet port on
1627 the guest, use the following:
1631 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1632 telnet localhost 5555
1635 Then when you use on the host @code{telnet localhost 5555}, you
1636 connect to the guest telnet server.
1638 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1639 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1640 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1641 to the character device @var{dev} or to a program executed by @var{cmd:command}
1642 which gets spawned for each connection. This option can be given multiple times.
1644 You can either use a chardev directly and have that one used throughout QEMU's
1645 lifetime
, like
in the following example
:
1648 # open
10.10.1.1:4321 on bootup
, connect
10.0.2.100:1234 to it whenever
1649 # the guest accesses it
1650 qemu
-net user
,guestfwd
=tcp
:10.0.2.100:1234-tcp
:10.10.1.1:4321 [...]
1653 Or you can execute a command on every TCP connection established by the guest
,
1654 so that QEMU behaves similar to an inetd process
for that virtual server
:
1657 # call
"netcat 10.10.1.1 4321" on every TCP connection to
10.0.2.100:1234
1658 # and connect the TCP stream to its stdin
/stdout
1659 qemu
-net
'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1664 Note
: Legacy stand
-alone options
-tftp
, -bootp
, -smb and
-redir are still
1665 processed and applied to
-net user
. Mixing them with the
new configuration
1666 syntax gives undefined results
. Their use
for new applications is discouraged
1667 as they will be removed from future versions
.
1669 @item
-netdev tap
,id
=@
var{id
}[,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1670 @item
-net tap
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1671 Connect the host TAP network
interface @
var{name
} to VLAN @
var{n
}.
1673 Use the network script @
var{file
} to configure it and the network script
1674 @
var{dfile
} to deconfigure it
. If @
var{name
} is not provided
, the OS
1675 automatically provides one
. The
default network configure script is
1676 @file
{/etc
/qemu
-ifup
} and the
default network deconfigure script is
1677 @file
{/etc
/qemu
-ifdown
}. Use @option
{script
=no
} or @option
{downscript
=no
}
1678 to disable script execution
.
1680 If running QEMU as an unprivileged user
, use the network helper
1681 @
var{helper
} to configure the TAP
interface. The
default network
1682 helper executable is @file
{/path
/to
/qemu
-bridge
-helper
}.
1684 @option
{fd
}=@
var{h
} can be used to specify the handle of an already
1685 opened host TAP
interface.
1690 #launch a QEMU instance with the
default network script
1691 qemu
-system
-i386 linux
.img
-net nic
-net tap
1695 #launch a QEMU instance with two NICs
, each one connected
1697 qemu
-system
-i386 linux
.img \
1698 -net nic
,vlan
=0 -net tap
,vlan
=0,ifname
=tap0 \
1699 -net nic
,vlan
=1 -net tap
,vlan
=1,ifname
=tap1
1703 #launch a QEMU instance with the
default network helper to
1704 #connect a TAP device to bridge br0
1705 qemu
-system
-i386 linux
.img \
1706 -net nic
-net tap
,"helper=/path/to/qemu-bridge-helper"
1709 @item
-netdev bridge
,id
=@
var{id
}[,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1710 @item
-net bridge
[,vlan
=@
var{n
}][,name
=@
var{name
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1711 Connect a host TAP network
interface to a host bridge device
.
1713 Use the network helper @
var{helper
} to configure the TAP
interface and
1714 attach it to the bridge
. The
default network helper executable is
1715 @file
{/path
/to
/qemu
-bridge
-helper
} and the
default bridge
1716 device is @file
{br0
}.
1721 #launch a QEMU instance with the
default network helper to
1722 #connect a TAP device to bridge br0
1723 qemu
-system
-i386 linux
.img
-net bridge
-net nic
,model
=virtio
1727 #launch a QEMU instance with the
default network helper to
1728 #connect a TAP device to bridge qemubr0
1729 qemu
-system
-i386 linux
.img
-net bridge
,br
=qemubr0
-net nic
,model
=virtio
1732 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1733 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}] [,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1735 Connect the VLAN @
var{n
} to a remote VLAN
in another QEMU virtual
1736 machine
using a TCP socket connection
. If @option
{listen
} is
1737 specified
, QEMU waits
for incoming connections on @
var{port
}
1738 (@
var{host
} is optional
). @option
{connect
} is used to connect to
1739 another QEMU instance
using the @option
{listen
} option
. @option
{fd
}=@
var{h
}
1740 specifies an already opened TCP socket
.
1744 # launch a first QEMU instance
1745 qemu
-system
-i386 linux
.img \
1746 -net nic
,macaddr
=52:54:00:12:34:56 \
1747 -net socket
,listen
=:1234
1748 # connect the VLAN
0 of
this instance to the VLAN
0
1749 # of the first instance
1750 qemu
-system
-i386 linux
.img \
1751 -net nic
,macaddr
=52:54:00:12:34:57 \
1752 -net socket
,connect
=127.0.0.1:1234
1755 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1756 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1758 Create a VLAN @
var{n
} shared with another QEMU virtual
1759 machines
using a UDP multicast socket
, effectively making a bus
for
1760 every QEMU with same multicast address @
var{maddr
} and @
var{port
}.
1764 Several QEMU can be running on different hosts and share same
bus (assuming
1765 correct multicast setup
for these hosts
).
1767 mcast support is compatible with User Mode
Linux (argument @option
{eth@
var{N
}=mcast
}), see
1768 @url
{http
://user-mode-linux.sf.net}.
1770 Use @option
{fd
=h
} to specify an already opened UDP multicast socket
.
1775 # launch one QEMU instance
1776 qemu
-system
-i386 linux
.img \
1777 -net nic
,macaddr
=52:54:00:12:34:56 \
1778 -net socket
,mcast
=230.0.0.1:1234
1779 # launch another QEMU instance on same
"bus"
1780 qemu
-system
-i386 linux
.img \
1781 -net nic
,macaddr
=52:54:00:12:34:57 \
1782 -net socket
,mcast
=230.0.0.1:1234
1783 # launch yet another QEMU instance on same
"bus"
1784 qemu
-system
-i386 linux
.img \
1785 -net nic
,macaddr
=52:54:00:12:34:58 \
1786 -net socket
,mcast
=230.0.0.1:1234
1789 Example (User Mode Linux compat
.):
1791 # launch QEMU
instance (note mcast address selected
1793 qemu-system-i386 linux.img \
1794 -net nic,macaddr=52:54:00:12:34:56 \
1795 -net socket,mcast=239.192.168.1:1102
1797 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1800 Example (send packets from host's
1.2.3.4):
1802 qemu
-system
-i386 linux
.img \
1803 -net nic
,macaddr
=52:54:00:12:34:56 \
1804 -net socket
,mcast
=239.192.168.1:1102,localaddr
=1.2.3.4
1807 @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
}]
1808 @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
}]
1809 Connect VLAN @
var{n
} to L2TPv3 pseudowire
. L2TPv3 (RFC3391
) is a popular
1810 protocol to transport
Ethernet (and other Layer
2) data frames between
1811 two systems
. It is present
in routers
, firewalls and the Linux kernel
1812 (from version
3.3 onwards
).
1814 This transport allows a VM to communicate to another VM
, router or firewall directly
.
1816 @item src
=@
var{srcaddr
}
1817 source
address (mandatory
)
1818 @item dst
=@
var{dstaddr
}
1819 destination
address (mandatory
)
1821 select udp
encapsulation (default is ip
).
1822 @item srcport
=@
var{srcport
}
1824 @item dstport
=@
var{dstport
}
1825 destination udp port
.
1827 force v6
, otherwise defaults to v4
.
1828 @item rxcookie
=@
var{rxcookie
}
1829 @item txcookie
=@
var{txcookie
}
1830 Cookies are a weak form of security
in the l2tpv3 specification
.
1831 Their
function is mostly to prevent misconfiguration
. By
default they are
32
1834 Set cookie size to
64 bit instead of the
default 32
1836 Force a
'cut-down' L2TPv3 with no counter as
in
1837 draft
-mkonstan
-l2tpext
-keyed
-ipv6
-tunnel
-00
1839 Work around broken counter handling
in peer
. This may also help on
1840 networks which have packet reorder
.
1841 @item offset
=@
var{offset
}
1842 Add an extra offset between header and data
1844 For example
, to attach a VM running on host
4.3.2.1 via L2TPv3 to the bridge br
-lan
1845 on the remote Linux host
1.2.3.4:
1847 # Setup tunnel on linux host
using raw ip as encapsulation
1849 ip l2tp add tunnel remote
4.3.2.1 local
1.2.3.4 tunnel_id
1 peer_tunnel_id
1 \
1850 encap udp udp_sport
16384 udp_dport
16384
1851 ip l2tp add session tunnel_id
1 name vmtunnel0 session_id \
1852 0xFFFFFFFF peer_session_id
0xFFFFFFFF
1853 ifconfig vmtunnel0 mtu
1500
1854 ifconfig vmtunnel0 up
1855 brctl addif br
-lan vmtunnel0
1859 # launch QEMU instance
- if your network has reorder or is very lossy add
,pincounter
1861 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
1866 @item
-netdev vde
,id
=@
var{id
}[,sock
=@
var{socketpath
}][,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1867 @item
-net vde
[,vlan
=@
var{n
}][,name
=@
var{name
}][,sock
=@
var{socketpath
}] [,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1868 Connect VLAN @
var{n
} to PORT @
var{n
} of a vde
switch running on host and
1869 listening
for incoming connections on @
var{socketpath
}. Use GROUP @
var{groupname
}
1870 and MODE @
var{octalmode
} to change
default ownership and permissions
for
1871 communication port
. This option is only available
if QEMU has been compiled
1872 with vde support enabled
.
1877 vde_switch
-F
-sock
/tmp
/myswitch
1878 # launch QEMU instance
1879 qemu
-system
-i386 linux
.img
-net nic
-net vde
,sock
=/tmp
/myswitch
1882 @item
-netdev hubport
,id
=@
var{id
},hubid
=@
var{hubid
}
1884 Create a hub port on QEMU
"vlan" @
var{hubid
}.
1886 The hubport netdev lets you connect a NIC to a QEMU
"vlan" instead of a single
1887 netdev
. @code
{-net
} and @code
{-device
} with parameter @option
{vlan
} create the
1888 required hub automatically
.
1890 @item
-netdev vhost
-user
,chardev
=@
var{id
}[,vhostforce
=on|off
]
1892 Establish a vhost
-user netdev
, backed by a chardev @
var{id
}. The chardev should
1893 be a unix domain socket backed one
. The vhost
-user uses a specifically defined
1894 protocol to pass vhost ioctl replacement messages to an application on the other
1895 end of the socket
. On non
-MSIX guests
, the feature can be forced with
1900 qemu
-m
512 -object memory
-backend
-file
,id
=mem
,size
=512M
,mem
-path
=/hugetlbfs
,share
=on \
1901 -numa node
,memdev
=mem \
1902 -chardev socket
,path
=/path
/to
/socket \
1903 -netdev type
=vhost
-user
,id
=net0
,chardev
=chr0 \
1904 -device virtio
-net
-pci
,netdev
=net0
1907 @item
-net dump
[,vlan
=@
var{n
}][,file
=@
var{file
}][,len
=@
var{len
}]
1908 Dump network traffic on VLAN @
var{n
} to file @
var{file
} (@file
{qemu
-vlan0
.pcap
} by
default).
1909 At most @
var{len
} bytes (64k by
default) per packet are stored
. The file format is
1910 libpcap
, so it can be analyzed with tools such as tcpdump or Wireshark
.
1913 Indicate that no network devices should be configured
. It is used to
1914 override the
default configuration (@option
{-net nic
-net user
}) which
1915 is activated
if no @option
{-net
} options are provided
.
1923 DEFHEADING(Character device options
:)
1926 The general form of a character device option is
:
1930 DEF("chardev", HAS_ARG
, QEMU_OPTION_chardev
,
1931 "-chardev null,id=id[,mux=on|off]\n"
1932 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay]\n"
1933 " [,server][,nowait][,telnet][,mux=on|off] (tcp)\n"
1934 "-chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix)\n"
1935 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
1936 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
1937 "-chardev msmouse,id=id[,mux=on|off]\n"
1938 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
1940 "-chardev ringbuf,id=id[,size=size]\n"
1941 "-chardev file,id=id,path=path[,mux=on|off]\n"
1942 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
1944 "-chardev console,id=id[,mux=on|off]\n"
1945 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1947 "-chardev pty,id=id[,mux=on|off]\n"
1948 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
1950 #ifdef CONFIG_BRLAPI
1951 "-chardev braille,id=id[,mux=on|off]\n"
1953 #
if defined(__linux__
) ||
defined(__sun__
) ||
defined(__FreeBSD__
) \
1954 ||
defined(__NetBSD__
) ||
defined(__OpenBSD__
) ||
defined(__DragonFly__
)
1955 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1956 "-chardev tty,id=id,path=path[,mux=on|off]\n"
1958 #
if defined(__linux__
) ||
defined(__FreeBSD__
) ||
defined(__DragonFly__
)
1959 "-chardev parallel,id=id,path=path[,mux=on|off]\n"
1960 "-chardev parport,id=id,path=path[,mux=on|off]\n"
1962 #
if defined(CONFIG_SPICE
)
1963 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
1964 "-chardev spiceport,id=id,name=name[,debug=debug]\n"
1970 @item
-chardev @
var{backend
} ,id
=@
var{id
} [,mux
=on|off
] [,@
var{options
}]
1991 The specific backend will determine the applicable options
.
1993 All devices must have an id
, which can be any string up to
127 characters long
.
1994 It is used to uniquely identify
this device
in other command line directives
.
1996 A character device may be used
in multiplexing mode by multiple front
-ends
.
1997 The key sequence of @key
{Control
-a
} and @key
{c
} will rotate the input focus
1998 between attached front
-ends
. Specify @option
{mux
=on
} to enable
this mode
.
2000 Options to each backend are described below
.
2002 @item
-chardev
null ,id
=@
var{id
}
2003 A void device
. This device will not emit any data
, and will drop any data it
2004 receives
. The
null backend does not take any options
.
2006 @item
-chardev socket
,id
=@
var{id
} [@
var{TCP options
} or @
var{unix options
}] [,server
] [,nowait
] [,telnet
]
2008 Create a two
-way stream socket
, which can be either a TCP or a unix socket
. A
2009 unix socket will be created
if @option
{path
} is specified
. Behaviour is
2010 undefined
if TCP options are specified
for a unix socket
.
2012 @option
{server
} specifies that the socket shall be a listening socket
.
2014 @option
{nowait
} specifies that QEMU should not block waiting
for a client to
2015 connect to a listening socket
.
2017 @option
{telnet
} specifies that traffic on the socket should interpret telnet
2020 TCP and unix socket options are given below
:
2024 @item TCP options
: port
=@
var{port
} [,host
=@
var{host
}] [,to
=@
var{to
}] [,ipv4
] [,ipv6
] [,nodelay
]
2026 @option
{host
} for a listening socket specifies the local address to be bound
.
2027 For a connecting socket species the remote host to connect to
. @option
{host
} is
2028 optional
for listening sockets
. If not specified it defaults to @code
{0.0.0.0}.
2030 @option
{port
} for a listening socket specifies the local port to be bound
. For a
2031 connecting socket specifies the port on the remote host to connect to
.
2032 @option
{port
} can be given as either a port number or a service name
.
2033 @option
{port
} is required
.
2035 @option
{to
} is only relevant to listening sockets
. If it is specified
, and
2036 @option
{port
} cannot be bound
, QEMU will attempt to bind to subsequent ports up
2037 to and including @option
{to
} until it succeeds
. @option
{to
} must be specified
2040 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2041 If neither is specified the socket may use either protocol
.
2043 @option
{nodelay
} disables the Nagle algorithm
.
2045 @item unix options
: path
=@
var{path
}
2047 @option
{path
} specifies the local path of the unix socket
. @option
{path
} is
2052 @item
-chardev udp
,id
=@
var{id
} [,host
=@
var{host
}] ,port
=@
var{port
} [,localaddr
=@
var{localaddr
}] [,localport
=@
var{localport
}] [,ipv4
] [,ipv6
]
2054 Sends all traffic from the guest to a remote host over UDP
.
2056 @option
{host
} specifies the remote host to connect to
. If not specified it
2057 defaults to @code
{localhost
}.
2059 @option
{port
} specifies the port on the remote host to connect to
. @option
{port
}
2062 @option
{localaddr
} specifies the local address to bind to
. If not specified it
2063 defaults to @code
{0.0.0.0}.
2065 @option
{localport
} specifies the local port to bind to
. If not specified any
2066 available local port will be used
.
2068 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2069 If neither is specified the device may use either protocol
.
2071 @item
-chardev msmouse
,id
=@
var{id
}
2073 Forward QEMU
's emulated msmouse events to the guest. @option{msmouse} does not
2076 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2078 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2081 @option{width} and @option{height} specify the width and height respectively of
2082 the console, in pixels.
2084 @option{cols} and @option{rows} specify that the console be sized to fit a text
2085 console with the given dimensions.
2087 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2089 Create a ring buffer with fixed size @option{size}.
2090 @var{size} must be a power of two, and defaults to @code{64K}).
2092 @item -chardev file ,id=@var{id} ,path=@var{path}
2094 Log all traffic received from the guest to a file.
2096 @option{path} specifies the path of the file to be opened. This file will be
2097 created if it does not already exist, and overwritten if it does. @option{path}
2100 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2102 Create a two-way connection to the guest. The behaviour differs slightly between
2103 Windows hosts and other hosts:
2105 On Windows, a single duplex pipe will be created at
2106 @file{\\.pipe\@option{path}}.
2108 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2109 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2110 received by the guest. Data written by the guest can be read from
2111 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2114 @option{path} forms part of the pipe path as described above. @option{path} is
2117 @item -chardev console ,id=@var{id}
2119 Send traffic from the guest to QEMU's standard output
. @option
{console
} does not
2122 @option
{console
} is only available on Windows hosts
.
2124 @item
-chardev serial
,id
=@
var{id
} ,path
=@option
{path
}
2126 Send traffic from the guest to a serial device on the host
.
2128 On Unix hosts serial will actually accept any tty device
,
2129 not only serial lines
.
2131 @option
{path
} specifies the name of the serial device to open
.
2133 @item
-chardev pty
,id
=@
var{id
}
2135 Create a
new pseudo
-terminal on the host and connect to it
. @option
{pty
} does
2136 not take any options
.
2138 @option
{pty
} is not available on Windows hosts
.
2140 @item
-chardev stdio
,id
=@
var{id
} [,signal
=on|off
]
2141 Connect to standard input and standard output of the QEMU process
.
2143 @option
{signal
} controls
if signals are enabled on the terminal
, that includes
2144 exiting QEMU with the key sequence @key
{Control
-c
}. This option is enabled by
2145 default, use @option
{signal
=off
} to disable it
.
2147 @option
{stdio
} is not available on Windows hosts
.
2149 @item
-chardev braille
,id
=@
var{id
}
2151 Connect to a local BrlAPI server
. @option
{braille
} does not take any options
.
2153 @item
-chardev tty
,id
=@
var{id
} ,path
=@
var{path
}
2155 @option
{tty
} is only available on Linux
, Sun
, FreeBSD
, NetBSD
, OpenBSD and
2156 DragonFlyBSD hosts
. It is an alias
for @option
{serial
}.
2158 @option
{path
} specifies the path to the tty
. @option
{path
} is required
.
2160 @item
-chardev parallel
,id
=@
var{id
} ,path
=@
var{path
}
2161 @item
-chardev parport
,id
=@
var{id
} ,path
=@
var{path
}
2163 @option
{parallel
} is only available on Linux
, FreeBSD and DragonFlyBSD hosts
.
2165 Connect to a local parallel port
.
2167 @option
{path
} specifies the path to the parallel port device
. @option
{path
} is
2170 @item
-chardev spicevmc
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2172 @option
{spicevmc
} is only available when spice support is built
in.
2174 @option
{debug
} debug level
for spicevmc
2176 @option
{name
} name of spice channel to connect to
2178 Connect to a spice virtual machine channel
, such as vdiport
.
2180 @item
-chardev spiceport
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2182 @option
{spiceport
} is only available when spice support is built
in.
2184 @option
{debug
} debug level
for spicevmc
2186 @option
{name
} name of spice port to connect to
2188 Connect to a spice port
, allowing a Spice client to handle the traffic
2189 identified by a
name (preferably a fqdn
).
2197 DEFHEADING(Device URL Syntax
:)
2200 In addition to
using normal file images
for the emulated storage devices
,
2201 QEMU can also use networked resources such as iSCSI devices
. These are
2202 specified
using a special URL syntax
.
2206 iSCSI support allows QEMU to access iSCSI resources directly and use as
2207 images
for the guest storage
. Both disk and cdrom images are supported
.
2209 Syntax
for specifying iSCSI LUNs is
2210 ``iscsi
://<target-ip>[:<port>]/<target-iqn>/<lun>''
2212 By
default qemu will use the iSCSI initiator
-name
2213 'iqn.2008-11.org.linux-kvm[:<name>]' but
this can also be set from the command
2214 line or a configuration file
.
2217 Example (without authentication
):
2219 qemu
-system
-i386
-iscsi initiator
-name
=iqn
.2001-04.com
.example
:my
-initiator \
2220 -cdrom iscsi
://192.0.2.1/iqn.2001-04.com.example/2 \
2221 -drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2224 Example (CHAP username
/password via URL
):
2226 qemu
-system
-i386
-drive file
=iscsi
://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2229 Example (CHAP username
/password via environment variables
):
2231 LIBISCSI_CHAP_USERNAME
="user" \
2232 LIBISCSI_CHAP_PASSWORD
="password" \
2233 qemu
-system
-i386
-drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2236 iSCSI support is an optional feature of QEMU and only available when
2237 compiled and linked against libiscsi
.
2239 DEF("iscsi", HAS_ARG
, QEMU_OPTION_iscsi
,
2240 "-iscsi [user=user][,password=password]\n"
2241 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2242 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2243 " iSCSI session parameters\n", QEMU_ARCH_ALL
)
2246 iSCSI parameters such as username and password can also be specified via
2247 a configuration file
. See qemu
-doc
for more information and examples
.
2250 QEMU supports
NBD (Network Block Devices
) both
using TCP protocol as well
2251 as Unix Domain Sockets
.
2253 Syntax
for specifying a NBD device
using TCP
2254 ``nbd
:<server
-ip
>:<port
>[:exportname
=<export
>]''
2256 Syntax
for specifying a NBD device
using Unix Domain Sockets
2257 ``nbd
:unix
:<domain
-socket
>[:exportname
=<export
>]''
2262 qemu
-system
-i386
--drive file
=nbd
:192.0.2.1:30000
2265 Example
for Unix Domain Sockets
2267 qemu
-system
-i386
--drive file
=nbd
:unix
:/tmp
/nbd
-socket
2271 QEMU supports
SSH (Secure Shell
) access to remote disks
.
2275 qemu
-system
-i386
-drive file
=ssh
://user@@host/path/to/disk.img
2276 qemu
-system
-i386
-drive file
.driver
=ssh
,file
.user
=user
,file
.host
=host
,file
.port
=22,file
.path
=/path
/to
/disk
.img
2279 Currently authentication must be done
using ssh
-agent
. Other
2280 authentication methods may be supported
in future
.
2283 Sheepdog is a distributed storage system
for QEMU
.
2284 QEMU supports
using either local sheepdog devices or remote networked
2287 Syntax
for specifying a sheepdog device
2289 sheepdog
[+tcp|
+unix
]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2294 qemu
-system
-i386
--drive file
=sheepdog
://192.0.2.1:30000/MyVirtualMachine
2297 See also @url
{http
://http://www.osrg.net/sheepdog/}.
2300 GlusterFS is an user space distributed file system
.
2301 QEMU supports the use of GlusterFS volumes
for hosting VM disk images
using
2302 TCP
, Unix Domain Sockets and RDMA transport protocols
.
2304 Syntax
for specifying a VM disk image on GlusterFS volume is
2306 gluster
[+transport
]://[server[:port]]/volname/image[?socket=...]
2312 qemu
-system
-x86_64
--drive file
=gluster
://192.0.2.1/testvol/a.img
2315 See also @url
{http
://www.gluster.org}.
2317 @item HTTP
/HTTPS
/FTP
/FTPS
/TFTP
2318 QEMU supports read
-only access to files accessed over
http(s
), ftp(s
) and tftp
.
2320 Syntax
using a single filename
:
2322 <protocol
>://[<username>[:<password>]@@]<host>/<path>
2328 'http', 'https', 'ftp', 'ftps', or
'tftp'.
2331 Optional username
for authentication to the remote server
.
2334 Optional password
for authentication to the remote server
.
2337 Address of the remote server
.
2340 Path on the remote server
, including any query string
.
2343 The following options are also supported
:
2346 The full URL when passing options to the driver explicitly
.
2349 The amount of data to read ahead with each range request to the remote server
.
2350 This value may optionally have the suffix
'T', 'G', 'M', 'K', 'k' or
'b'. If it
2351 does not have a suffix
, it will be assumed to be
in bytes
. The value must be a
2352 multiple of
512 bytes
. It defaults to
256k
.
2355 Whether to verify the remote server
's certificate when connecting over SSL. It
2356 can have the value 'on
' or 'off
'. It defaults to 'on
'.
2359 Note that when passing options to qemu explicitly, @option{driver} is the value
2362 Example: boot from a remote Fedora 20 live ISO image
2364 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
2366 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
2369 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2370 writes, copy-on-read, and a readahead of 64k
2372 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
2374 qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
2377 Example: boot from an image stored on a VMware vSphere server with a self-signed
2378 certificate using a local overlay for writes and a readahead of 64k
2380 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
2382 qemu-system-x86_64 -drive file=/tmp/test.qcow2
2390 DEFHEADING(Bluetooth(R) options:)
2395 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2396 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands
\n" \
2397 "-bt hci
,host
[:id
]\n" \
2398 " use host
's HCI with the given name\n" \
2399 "-bt hci[,vlan=n]\n" \
2400 " emulate a standard HCI in virtual scatternet 'n
'\n" \
2401 "-bt vhci[,vlan=n]\n" \
2402 " add host computer to virtual scatternet 'n
' using VHCI\n" \
2403 "-bt device:dev[,vlan=n]\n" \
2404 " emulate a bluetooth device 'dev
' in scatternet 'n
'\n",
2409 Defines the function of the corresponding Bluetooth HCI. -bt options
2410 are matched with the HCIs present in the chosen machine type. For
2411 example when emulating a machine with only one HCI built into it, only
2412 the first @code{-bt hci[...]} option is valid and defines the HCI's
2413 logic
. The Transport Layer is decided by the machine type
. Currently
2414 the machines @code
{n800
} and @code
{n810
} have one HCI and all other
2418 The following three types are recognized
:
2422 (default) The corresponding Bluetooth HCI assumes no internal logic
2423 and will not respond to any HCI commands or emit events
.
2425 @item
-bt hci
,host
[:@
var{id
}]
2426 (@code
{bluez
} only
) The corresponding HCI passes commands
/ events
2427 to
/ from the physical HCI identified by the name @
var{id
} (default:
2428 @code
{hci0
}) on the computer running QEMU
. Only available on @code
{bluez
}
2429 capable systems like Linux
.
2431 @item
-bt hci
[,vlan
=@
var{n
}]
2432 Add a virtual
, standard HCI that will participate
in the Bluetooth
2433 scatternet @
var{n
} (default @code
{0}). Similarly to @option
{-net
}
2434 VLANs
, devices inside a bluetooth network @
var{n
} can only communicate
2435 with other devices
in the same
network (scatternet
).
2438 @item
-bt vhci
[,vlan
=@
var{n
}]
2439 (Linux
-host only
) Create a HCI
in scatternet @
var{n
} (default 0) attached
2440 to the host bluetooth stack instead of to the emulated target
. This
2441 allows the host and target machines to participate
in a common scatternet
2442 and communicate
. Requires the Linux @code
{vhci
} driver installed
. Can
2443 be used as following
:
2446 qemu
-system
-i386
[...OPTIONS
...] -bt hci
,vlan
=5 -bt vhci
,vlan
=5
2449 @item
-bt device
:@
var{dev
}[,vlan
=@
var{n
}]
2450 Emulate a bluetooth device @
var{dev
} and place it
in network @
var{n
}
2451 (default @code
{0}). QEMU can only emulate one type of bluetooth devices
2456 Virtual wireless keyboard implementing the HIDP bluetooth profile
.
2466 DEFHEADING(TPM device options
:)
2468 DEF("tpmdev", HAS_ARG
, QEMU_OPTION_tpmdev
, \
2469 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2470 " use path to provide path to a character device; default is /dev/tpm0\n"
2471 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2472 " not provided it will be searched for in /sys/class/misc/tpm?/device\n",
2476 The general form of a TPM device option is
:
2479 @item
-tpmdev @
var{backend
} ,id
=@
var{id
} [,@
var{options
}]
2481 Backend type must be
:
2482 @option
{passthrough
}.
2484 The specific backend type will determine the applicable options
.
2485 The @code
{-tpmdev
} option creates the TPM backend and requires a
2486 @code
{-device
} option that specifies the TPM frontend
interface model
.
2488 Options to each backend are described below
.
2490 Use
'help' to print all available TPM backend types
.
2495 @item
-tpmdev passthrough
, id
=@
var{id
}, path
=@
var{path
}, cancel
-path
=@
var{cancel
-path
}
2497 (Linux
-host only
) Enable access to the host
's TPM using the passthrough
2500 @option{path} specifies the path to the host's TPM device
, i
.e
., on
2501 a Linux host
this would be @code
{/dev
/tpm0
}.
2502 @option
{path
} is optional and by
default @code
{/dev
/tpm0
} is used
.
2504 @option
{cancel
-path
} specifies the path to the host TPM device
's sysfs
2505 entry allowing for cancellation of an ongoing TPM command.
2506 @option{cancel-path} is optional and by default QEMU will search for the
2509 Some notes about using the host's TPM with the passthrough driver
:
2511 The TPM device accessed by the passthrough driver must not be
2512 used by any other application on the host
.
2514 Since the host
's firmware (BIOS/UEFI) has already initialized the TPM,
2515 the VM's
firmware (BIOS
/UEFI
) will not be able to initialize the
2516 TPM again and may therefore not show a TPM
-specific menu that would
2517 otherwise allow the user to configure the TPM
, e
.g
., allow the user to
2518 enable
/disable or activate
/deactivate the TPM
.
2519 Further
, if TPM ownership is released from within a VM then the host
's TPM
2520 will get disabled and deactivated. To enable and activate the
2521 TPM again afterwards, the host has to be rebooted and the user is
2522 required to enter the firmware's menu to enable and activate the TPM
.
2523 If the TPM is left disabled and
/or deactivated most TPM commands will fail
.
2525 To create a passthrough TPM use the following two options
:
2527 -tpmdev passthrough
,id
=tpm0
-device tpm
-tis
,tpmdev
=tpm0
2529 Note that the @code
{-tpmdev
} id is @code
{tpm0
} and is referenced by
2530 @code
{tpmdev
=tpm0
} in the device option
.
2540 DEFHEADING(Linux
/Multiboot boot specific
:)
2543 When
using these options
, you can use a given Linux or Multiboot
2544 kernel without installing it
in the disk image
. It can be useful
2545 for easier testing of various kernels
.
2550 DEF("kernel", HAS_ARG
, QEMU_OPTION_kernel
, \
2551 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL
)
2553 @item
-kernel @
var{bzImage
}
2555 Use @
var{bzImage
} as kernel image
. The kernel can be either a Linux kernel
2556 or
in multiboot format
.
2559 DEF("append", HAS_ARG
, QEMU_OPTION_append
, \
2560 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL
)
2562 @item
-append @
var{cmdline
}
2564 Use @
var{cmdline
} as kernel command line
2567 DEF("initrd", HAS_ARG
, QEMU_OPTION_initrd
, \
2568 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL
)
2570 @item
-initrd @
var{file
}
2572 Use @
var{file
} as initial ram disk
.
2574 @item
-initrd
"@var{file1} arg=foo,@var{file2}"
2576 This syntax is only available with multiboot
.
2578 Use @
var{file1
} and @
var{file2
} as modules and pass arg
=foo as parameter to the
2582 DEF("dtb", HAS_ARG
, QEMU_OPTION_dtb
, \
2583 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL
)
2585 @item
-dtb @
var{file
}
2587 Use @
var{file
} as a device tree
binary (dtb
) image and pass it to the kernel
2596 DEFHEADING(Debug
/Expert options
:)
2601 DEF("serial", HAS_ARG
, QEMU_OPTION_serial
, \
2602 "-serial dev redirect the serial port to char device 'dev'\n",
2605 @item
-serial @
var{dev
}
2607 Redirect the virtual serial port to host character device
2608 @
var{dev
}. The
default device is @code
{vc
} in graphical mode and
2609 @code
{stdio
} in non graphical mode
.
2611 This option can be used several times to simulate up to
4 serial
2614 Use @code
{-serial none
} to disable all serial ports
.
2616 Available character devices are
:
2618 @item vc
[:@
var{W
}x@
var{H
}]
2619 Virtual console
. Optionally
, a width and height can be given
in pixel with
2623 It is also possible to specify width or height
in characters
:
2628 [Linux only
] Pseudo
TTY (a
new PTY is automatically allocated
)
2630 No device is allocated
.
2633 @item chardev
:@
var{id
}
2634 Use a named character device defined with the @code
{-chardev
} option
.
2636 [Linux only
] Use host tty
, e
.g
. @file
{/dev
/ttyS0
}. The host serial port
2637 parameters are set according to the emulated ones
.
2638 @item
/dev
/parport@
var{N
}
2639 [Linux only
, parallel port only
] Use host parallel port
2640 @
var{N
}. Currently SPP and EPP parallel port features can be used
.
2641 @item file
:@
var{filename
}
2642 Write output to @
var{filename
}. No character can be read
.
2644 [Unix only
] standard input
/output
2645 @item pipe
:@
var{filename
}
2646 name pipe @
var{filename
}
2648 [Windows only
] Use host serial port @
var{n
}
2649 @item udp
:[@
var{remote_host
}]:@
var{remote_port
}[@@
[@
var{src_ip
}]:@
var{src_port
}]
2650 This
implements UDP Net Console
.
2651 When @
var{remote_host
} or @
var{src_ip
} are not specified
2652 they
default to @code
{0.0.0.0}.
2653 When not
using a specified @
var{src_port
} a random port is automatically chosen
.
2655 If you just want a simple readonly console you can use @code
{netcat
} or
2656 @code
{nc
}, by starting QEMU with
: @code
{-serial udp
::4555} and nc as
:
2657 @code
{nc
-u
-l
-p
4555}. Any time QEMU writes something to that port it
2658 will appear
in the netconsole session
.
2660 If you plan to send characters back via netconsole or you want to stop
2661 and start QEMU a lot of times
, you should have QEMU use the same
2662 source port each time by
using something like @code
{-serial
2663 udp
::4555@@
:4556} to QEMU
. Another approach is to use a patched
2664 version of netcat which can listen to a TCP port and send and receive
2665 characters via udp
. If you have a patched version of netcat which
2666 activates telnet remote echo and single char transfer
, then you can
2667 use the following options to step up a netcat redirector to allow
2668 telnet on port
5555 to access the QEMU port
.
2671 -serial udp
::4555@@
:4556
2672 @item netcat options
:
2673 -u
-P
4555 -L
0.0.0.0:4556 -t
-p
5555 -I
-T
2674 @item telnet options
:
2678 @item tcp
:[@
var{host
}]:@
var{port
}[,@
var{server
}][,nowait
][,nodelay
]
2679 The TCP Net Console has two modes of operation
. It can send the serial
2680 I
/O to a location or wait
for a connection from a location
. By
default
2681 the TCP Net Console is sent to @
var{host
} at the @
var{port
}. If you use
2682 the @
var{server
} option QEMU will wait
for a client socket application
2683 to connect to the port before continuing
, unless the @code
{nowait
}
2684 option was specified
. The @code
{nodelay
} option disables the Nagle buffering
2685 algorithm
. If @
var{host
} is omitted
, 0.0.0.0 is assumed
. Only
2686 one TCP connection at a time is accepted
. You can use @code
{telnet
} to
2687 connect to the corresponding character device
.
2689 @item Example to send tcp console to
192.168.0.2 port
4444
2690 -serial tcp
:192.168.0.2:4444
2691 @item Example to listen and wait on port
4444 for connection
2692 -serial tcp
::4444,server
2693 @item Example to not wait and listen on ip
192.168.0.100 port
4444
2694 -serial tcp
:192.168.0.100:4444,server
,nowait
2697 @item telnet
:@
var{host
}:@
var{port
}[,server
][,nowait
][,nodelay
]
2698 The telnet protocol is used instead of raw tcp sockets
. The options
2699 work the same as
if you had specified @code
{-serial tcp
}. The
2700 difference is that the port acts like a telnet server or client
using
2701 telnet option negotiation
. This will also allow you to send the
2702 MAGIC_SYSRQ sequence
if you use a telnet that supports sending the
break
2703 sequence
. Typically
in unix telnet you
do it with Control
-] and then
2704 type
"send break" followed by pressing the enter key
.
2706 @item unix
:@
var{path
}[,server
][,nowait
]
2707 A unix domain socket is used instead of a tcp socket
. The option works the
2708 same as
if you had specified @code
{-serial tcp
} except the unix domain socket
2709 @
var{path
} is used
for connections
.
2711 @item mon
:@
var{dev_string
}
2712 This is a special option to allow the monitor to be multiplexed onto
2713 another serial port
. The monitor is accessed with key sequence of
2714 @key
{Control
-a
} and then pressing @key
{c
}.
2715 @
var{dev_string
} should be any one of the serial devices specified
2716 above
. An example to multiplex the monitor onto a telnet server
2717 listening on port
4444 would be
:
2719 @item
-serial mon
:telnet
::4444,server
,nowait
2721 When the monitor is multiplexed to stdio
in this way
, Ctrl
+C will not terminate
2722 QEMU any more but will be passed to the guest instead
.
2725 Braille device
. This will use BrlAPI to display the braille output on a real
2729 Three button serial mouse
. Configure the guest to use Microsoft protocol
.
2733 DEF("parallel", HAS_ARG
, QEMU_OPTION_parallel
, \
2734 "-parallel dev redirect the parallel port to char device 'dev'\n",
2737 @item
-parallel @
var{dev
}
2739 Redirect the virtual parallel port to host device @
var{dev
} (same
2740 devices as the serial port
). On Linux hosts
, @file
{/dev
/parportN
} can
2741 be used to use hardware devices connected on the corresponding host
2744 This option can be used several times to simulate up to
3 parallel
2747 Use @code
{-parallel none
} to disable all parallel ports
.
2750 DEF("monitor", HAS_ARG
, QEMU_OPTION_monitor
, \
2751 "-monitor dev redirect the monitor to char device 'dev'\n",
2754 @item
-monitor @
var{dev
}
2756 Redirect the monitor to host device @
var{dev
} (same devices as the
2758 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2760 Use @code
{-monitor none
} to disable the
default monitor
.
2762 DEF("qmp", HAS_ARG
, QEMU_OPTION_qmp
, \
2763 "-qmp dev like -monitor but opens in 'control' mode\n",
2766 @item
-qmp @
var{dev
}
2768 Like
-monitor but opens
in 'control' mode
.
2771 DEF("mon", HAS_ARG
, QEMU_OPTION_mon
, \
2772 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL
)
2774 @item
-mon
[chardev
=]name
[,mode
=readline|control
][,default]
2776 Setup monitor on chardev @
var{name
}.
2779 DEF("debugcon", HAS_ARG
, QEMU_OPTION_debugcon
, \
2780 "-debugcon dev redirect the debug console to char device 'dev'\n",
2783 @item
-debugcon @
var{dev
}
2785 Redirect the debug console to host device @
var{dev
} (same devices as the
2786 serial port
). The debug console is an I
/O port which is typically port
2787 0xe9; writing to that I
/O port sends output to
this device
.
2788 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2792 DEF("pidfile", HAS_ARG
, QEMU_OPTION_pidfile
, \
2793 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL
)
2795 @item
-pidfile @
var{file
}
2797 Store the QEMU process PID
in @
var{file
}. It is useful
if you launch QEMU
2801 DEF("singlestep", 0, QEMU_OPTION_singlestep
, \
2802 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL
)
2806 Run the emulation
in single step mode
.
2809 DEF("S", 0, QEMU_OPTION_S
, \
2810 "-S freeze CPU at startup (use 'c' to start execution)\n",
2815 Do not start CPU at
startup (you must type
'c' in the monitor
).
2818 DEF("realtime", HAS_ARG
, QEMU_OPTION_realtime
,
2819 "-realtime [mlock=on|off]\n"
2820 " run qemu with realtime features\n"
2821 " mlock=on|off controls mlock support (default: on)\n",
2824 @item
-realtime mlock
=on|off
2826 Run qemu with realtime features
.
2827 mlocking qemu and guest memory can be enabled via @option
{mlock
=on
}
2828 (enabled by
default).
2831 DEF("gdb", HAS_ARG
, QEMU_OPTION_gdb
, \
2832 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL
)
2834 @item
-gdb @
var{dev
}
2836 Wait
for gdb connection on device @
var{dev
} (@pxref
{gdb_usage
}). Typical
2837 connections will likely be TCP
-based
, but also UDP
, pseudo TTY
, or even
2838 stdio are reasonable use
case. The latter is allowing to start QEMU from
2839 within gdb and establish the connection via a pipe
:
2841 (gdb
) target remote | exec qemu
-system
-i386
-gdb stdio
...
2845 DEF("s", 0, QEMU_OPTION_s
, \
2846 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT
"\n",
2851 Shorthand
for -gdb tcp
::1234, i
.e
. open a gdbserver on TCP port
1234
2852 (@pxref
{gdb_usage
}).
2855 DEF("d", HAS_ARG
, QEMU_OPTION_d
, \
2856 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
2859 @item
-d @
var{item1
}[,...]
2861 Enable logging of specified items
. Use
'-d help' for a list of log items
.
2864 DEF("D", HAS_ARG
, QEMU_OPTION_D
, \
2865 "-D logfile output log to logfile (default stderr)\n",
2868 @item
-D @
var{logfile
}
2870 Output log
in @
var{logfile
} instead of to stderr
2873 DEF("L", HAS_ARG
, QEMU_OPTION_L
, \
2874 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2879 Set the directory
for the BIOS
, VGA BIOS and keymaps
.
2882 DEF("bios", HAS_ARG
, QEMU_OPTION_bios
, \
2883 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL
)
2885 @item
-bios @
var{file
}
2887 Set the filename
for the BIOS
.
2890 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm
, \
2891 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL
)
2895 Enable KVM full virtualization support
. This option is only available
2896 if KVM support is enabled when compiling
.
2899 DEF("xen-domid", HAS_ARG
, QEMU_OPTION_xen_domid
,
2900 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL
)
2901 DEF("xen-create", 0, QEMU_OPTION_xen_create
,
2902 "-xen-create create domain using xen hypercalls, bypassing xend\n"
2903 " warning: should not be used when xend is in use\n",
2905 DEF("xen-attach", 0, QEMU_OPTION_xen_attach
,
2906 "-xen-attach attach to existing xen domain\n"
2907 " xend will use this when starting QEMU\n",
2910 @item
-xen
-domid @
var{id
}
2912 Specify xen guest domain @
var{id
} (XEN only
).
2915 Create domain
using xen hypercalls
, bypassing xend
.
2916 Warning
: should not be used when xend is
in use (XEN only
).
2919 Attach to existing xen domain
.
2920 xend will use
this when starting
QEMU (XEN only
).
2923 DEF("no-reboot", 0, QEMU_OPTION_no_reboot
, \
2924 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL
)
2928 Exit instead of rebooting
.
2931 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown
, \
2932 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL
)
2935 @findex
-no
-shutdown
2936 Don
't exit QEMU on guest shutdown, but instead only stop the emulation.
2937 This allows for instance switching to monitor to commit changes to the
2941 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
2942 "-loadvm [tag|id]\n" \
2943 " start right away with a saved state (loadvm in monitor)\n",
2946 @item -loadvm @var{file}
2948 Start right away with a saved state (@code{loadvm} in monitor)
2952 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
2953 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
2958 Daemonize the QEMU process after initialization. QEMU will not detach from
2959 standard IO until it is ready to receive connections on any of its devices.
2960 This option is a useful way for external programs to launch QEMU without having
2961 to cope with initialization race conditions.
2964 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
2965 "-option-rom rom load a file, rom, into the option ROM space\n",
2968 @item -option-rom @var{file}
2970 Load the contents of @var{file} as an option ROM.
2971 This option is useful to load things like EtherBoot.
2974 DEF("clock", HAS_ARG, QEMU_OPTION_clock, \
2975 "-clock force the use of the given methods for timer alarm.\n" \
2976 " To see what timers are available use '-clock help
'\n",
2979 @item -clock @var{method}
2981 Force the use of the given methods for timer alarm. To see what timers
2982 are available use @code{-clock help}.
2985 HXCOMM Options deprecated by -rtc
2986 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
2987 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
2989 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
2990 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
2991 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
2996 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
2998 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
2999 UTC or local time, respectively. @code{localtime} is required for correct date in
3000 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3001 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3003 By default the RTC is driven by the host system time. This allows using of the
3004 RTC as accurate reference clock inside the guest, specifically if the host
3005 time is smoothly following an accurate external reference clock, e.g. via NTP.
3006 If you want to isolate the guest time from the host, you can set @option{clock}
3007 to @code{rt} instead. To even prevent it from progressing during suspension,
3008 you can set it to @code{vm}.
3010 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3011 specifically with Windows' ACPI HAL
. This option will
try to figure out how
3012 many timer interrupts were not processed by the Windows guest and will
3016 DEF("icount", HAS_ARG
, QEMU_OPTION_icount
, \
3017 "-icount [shift=N|auto][,align=on|off]\n" \
3018 " enable virtual instruction counter with 2^N clock ticks per\n" \
3019 " instruction and enable aligning the host and virtual clocks\n", QEMU_ARCH_ALL
)
3021 @item
-icount
[shift
=@
var{N
}|auto
]
3023 Enable virtual instruction counter
. The virtual cpu will execute one
3024 instruction every
2^@
var{N
} ns of virtual time
. If @code
{auto
} is specified
3025 then the virtual cpu speed will be automatically adjusted to keep virtual
3026 time within a few seconds of real time
.
3028 Note that
while this option can give deterministic behavior
, it does not
3029 provide cycle accurate emulation
. Modern CPUs contain superscalar out of
3030 order cores with complex cache hierarchies
. The number of instructions
3031 executed often has little or no correlation with actual performance
.
3033 @option
{align
=on
} will activate the delay algorithm which will
try to
3034 to synchronise the host clock and the virtual clock
. The goal is to
3035 have a guest running at the real frequency imposed by the shift option
.
3036 Whenever the guest clock is behind the host clock and
if
3037 @option
{align
=on
} is specified then we print a messsage to the user
3038 to inform about the delay
.
3039 Currently
this option does not work when @option
{shift
} is @code
{auto
}.
3040 Note
: The sync algorithm will work
for those shift values
for which
3041 the guest clock runs ahead of the host clock
. Typically
this happens
3042 when the shift value is
high (how high depends on the host machine
).
3045 DEF("watchdog", HAS_ARG
, QEMU_OPTION_watchdog
, \
3046 "-watchdog i6300esb|ib700\n" \
3047 " enable virtual hardware watchdog [default=none]\n",
3050 @item
-watchdog @
var{model
}
3052 Create a virtual hardware watchdog device
. Once
enabled (by a guest
3053 action
), the watchdog must be periodically polled by an agent inside
3054 the guest or
else the guest will be restarted
.
3056 The @
var{model
} is the model of hardware watchdog to emulate
. Choices
3057 for model are
: @code
{ib700
} (iBASE
700) which is a very simple ISA
3058 watchdog with a single timer
, or @code
{i6300esb
} (Intel
6300ESB I
/O
3059 controller hub
) which is a much more featureful PCI
-based dual
-timer
3060 watchdog
. Choose a model
for which your guest has drivers
.
3062 Use @code
{-watchdog help
} to list available hardware models
. Only one
3063 watchdog can be enabled
for a guest
.
3066 DEF("watchdog-action", HAS_ARG
, QEMU_OPTION_watchdog_action
, \
3067 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3068 " action when watchdog fires [default=reset]\n",
3071 @item
-watchdog
-action @
var{action
}
3072 @findex
-watchdog
-action
3074 The @
var{action
} controls what QEMU will
do when the watchdog timer
3077 @code
{reset
} (forcefully reset the guest
).
3078 Other possible actions are
:
3079 @code
{shutdown
} (attempt to gracefully shutdown the guest
),
3080 @code
{poweroff
} (forcefully poweroff the guest
),
3081 @code
{pause
} (pause the guest
),
3082 @code
{debug
} (print a debug message and
continue), or
3083 @code
{none
} (do nothing
).
3085 Note that the @code
{shutdown
} action requires that the guest responds
3086 to ACPI signals
, which it may not be able to
do in the sort of
3087 situations where the watchdog would have expired
, and thus
3088 @code
{-watchdog
-action shutdown
} is not recommended
for production use
.
3093 @item
-watchdog i6300esb
-watchdog
-action pause
3094 @item
-watchdog ib700
3098 DEF("echr", HAS_ARG
, QEMU_OPTION_echr
, \
3099 "-echr chr set terminal escape character instead of ctrl-a\n",
3103 @item
-echr @
var{numeric_ascii_value
}
3105 Change the escape character used
for switching to the monitor when
using
3106 monitor and serial sharing
. The
default is @code
{0x01} when
using the
3107 @code
{-nographic
} option
. @code
{0x01} is equal to pressing
3108 @code
{Control
-a
}. You can select a different character from the ascii
3109 control keys where
1 through
26 map to Control
-a through Control
-z
. For
3110 instance you could use the either of the following to change the escape
3111 character to Control
-t
.
3118 DEF("virtioconsole", HAS_ARG
, QEMU_OPTION_virtiocon
, \
3119 "-virtioconsole c\n" \
3120 " set virtio console\n", QEMU_ARCH_ALL
)
3122 @item
-virtioconsole @
var{c
}
3123 @findex
-virtioconsole
3126 This option is maintained
for backward compatibility
.
3128 Please use @code
{-device virtconsole
} for the
new way of invocation
.
3131 DEF("show-cursor", 0, QEMU_OPTION_show_cursor
, \
3132 "-show-cursor show cursor\n", QEMU_ARCH_ALL
)
3135 @findex
-show
-cursor
3139 DEF("tb-size", HAS_ARG
, QEMU_OPTION_tb_size
, \
3140 "-tb-size n set TB size\n", QEMU_ARCH_ALL
)
3142 @item
-tb
-size @
var{n
}
3147 DEF("incoming", HAS_ARG
, QEMU_OPTION_incoming
, \
3148 "-incoming p prepare for incoming migration, listen on port p\n",
3151 @item
-incoming @
var{port
}
3153 Prepare
for incoming migration
, listen on @
var{port
}.
3156 DEF("nodefaults", 0, QEMU_OPTION_nodefaults
, \
3157 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL
)
3161 Don
't create default devices. Normally, QEMU sets the default devices like serial
3162 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3163 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3168 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3169 "-chroot dir chroot to dir just before starting the VM\n",
3173 @item -chroot @var{dir}
3175 Immediately before starting guest execution, chroot to the specified
3176 directory. Especially useful in combination with -runas.
3180 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3181 "-runas user change to user id user just before starting the VM\n",
3185 @item -runas @var{user}
3187 Immediately before starting guest execution, drop root privileges, switching
3188 to the specified user.
3191 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3192 "-prom-env variable=value\n"
3193 " set OpenBIOS nvram variables\n",
3194 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3196 @item -prom-env @var{variable}=@var{value}
3198 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3200 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3201 "-semihosting semihosting mode\n",
3202 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32)
3205 @findex -semihosting
3206 Semihosting mode (ARM, M68K, Xtensa only).
3208 DEF("old-param", 0, QEMU_OPTION_old_param,
3209 "-old-param old param mode\n", QEMU_ARCH_ARM)
3212 @findex -old-param (ARM)
3213 Old param mode (ARM only).
3216 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3217 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off
').\n",
3220 @item -sandbox @var{arg}
3222 Enable Seccomp mode 2 system call filter. 'on
' will enable syscall filtering and 'off
' will
3223 disable it. The default is 'off
'.
3226 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3227 "-readconfig <file>\n", QEMU_ARCH_ALL)
3229 @item -readconfig @var{file}
3231 Read device configuration from @var{file}. This approach is useful when you want to spawn
3232 QEMU process with many command line options but you don't want to exceed the command line
3235 DEF("writeconfig", HAS_ARG
, QEMU_OPTION_writeconfig
,
3236 "-writeconfig <file>\n"
3237 " read/write config file\n", QEMU_ARCH_ALL
)
3239 @item
-writeconfig @
var{file
}
3240 @findex
-writeconfig
3241 Write device configuration to @
var{file
}. The @
var{file
} can be either filename to save
3242 command line and device configuration into file or dash @code
{-}) character to print the
3243 output to stdout
. This can be later used as input file
for @code
{-readconfig
} option
.
3245 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig
,
3247 " do not load default config files at startup\n",
3251 @findex
-nodefconfig
3252 Normally QEMU loads configuration files from @
var{sysconfdir
} and @
var{datadir
} at startup
.
3253 The @code
{-nodefconfig
} option will prevent QEMU from loading any of those config files
.
3255 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig
,
3257 " do not load user-provided config files at startup\n",
3260 @item
-no
-user
-config
3261 @findex
-no
-user
-config
3262 The @code
{-no
-user
-config
} option makes QEMU not load any of the user
-provided
3263 config files on @
var{sysconfdir
}, but won
't make it skip the QEMU-provided config
3264 files from @var{datadir}.
3266 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3267 "-trace [events=<file>][,file=<file>]\n"
3268 " specify tracing options\n",
3271 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3272 HXCOMM HX does not support conditional compilation of text.
3273 @item -trace [events=@var{file}][,file=@var{file}]
3276 Specify tracing options.
3279 @item events=@var{file}
3280 Immediately enable events listed in @var{file}.
3281 The file must contain one event name (as listed in the @var{trace-events} file)
3283 This option is only available if QEMU has been compiled with
3284 either @var{simple} or @var{stderr} tracing backend.
3285 @item file=@var{file}
3286 Log output traces to @var{file}.
3288 This option is only available if QEMU has been compiled with
3289 the @var{simple} tracing backend.
3294 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3295 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3298 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3299 "-enable-fips enable FIPS 140-2 compliance\n",
3304 @findex -enable-fips
3305 Enable FIPS 140-2 compliance mode.
3308 HXCOMM Deprecated by -machine accel=tcg property
3309 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3311 HXCOMM Deprecated by kvm-pit driver properties
3312 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3315 HXCOMM Deprecated (ignored)
3316 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
3318 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3319 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3321 HXCOMM Deprecated (ignored)
3322 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3324 DEF("object", HAS_ARG, QEMU_OPTION_object,
3325 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3326 " create an new object of type TYPENAME setting properties\n"
3327 " in the order they are specified. Note that the 'id
'\n"
3328 " property must be set. These objects are placed in the\n"
3329 " '/objects
' path.\n",
3332 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3334 Create an new object of type @var{typename} setting properties
3335 in the order they are specified. Note that the 'id
'
3336 property must be set. These objects are placed in the
3340 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3341 "-msg timestamp[=on|off]\n"
3342 " change the format of messages\n"
3343 " on|off controls leading timestamps (default:on)\n",
3346 @item -msg timestamp[=on|off]
3348 prepend a timestamp to each log message.(default:on)
3351 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3352 "-dump-vmstate <file>\n"
3353 " Output vmstate information in JSON format to file.\n"
3354 " Use the scripts/vmstate-static-checker.py file to\n"
3355 " check for possible regressions in migration code\n"
3356 " by comparing two such vmstate dumps.",
3359 @item -dump-vmstate @var{file}
3360 @findex -dump-vmstate
3361 Dump json-encoded vmstate information for current machine type to file
3365 HXCOMM This is the last statement. Insert new options before this line!