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 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
37 " kvm_shadow_mem=size of KVM shadow MMU\n"
38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
39 " mem-merge=on|off controls memory merge support (default: on)\n"
40 " iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n"
41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n",
46 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
48 Select the emulated machine by @
var{name
}. Use @code
{-machine help
} to list
49 available machines
. Supported machine properties are
:
51 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
52 This is used to enable an accelerator
. Depending on the target architecture
,
53 kvm
, xen
, or tcg can be available
. By
default, tcg is used
. If there is more
54 than one accelerator specified
, the next one is used
if the previous one fails
56 @item kernel_irqchip
=on|off
57 Enables
in-kernel irqchip support
for the chosen accelerator when available
.
58 @item vmport
=on|off|auto
59 Enables emulation of VMWare IO port
, for vmmouse etc
. auto says to select the
60 value based on accel
. For accel
=xen the
default is off otherwise the
default
62 @item kvm_shadow_mem
=size
63 Defines the size of the KVM shadow MMU
.
64 @item dump
-guest
-core
=on|off
65 Include guest memory
in a core dump
. The
default is on
.
66 @item mem
-merge
=on|off
67 Enables or disables memory merge support
. This feature
, when supported by
68 the host
, de
-duplicates identical memory pages among VMs instances
71 Enables or disables emulated Intel
IOMMU (VT
-d
) support
. The
default is off
.
72 @item aes
-key
-wrap
=on|off
73 Enables or disables AES key wrapping support on s390
-ccw hosts
. This feature
74 controls whether AES wrapping keys will be created to allow
75 execution of AES cryptographic functions
. The
default is on
.
76 @item dea
-key
-wrap
=on|off
77 Enables or disables DEA key wrapping support on s390
-ccw hosts
. This feature
78 controls whether DEA wrapping keys will be created to allow
79 execution of DEA cryptographic functions
. The
default is on
.
83 HXCOMM Deprecated by
-machine
84 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
86 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
87 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
89 @item
-cpu @
var{model
}
91 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
94 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
95 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
96 " set the number of CPUs to 'n' [default=1]\n"
97 " maxcpus= maximum number of total cpus, including\n"
98 " offline CPUs for hotplug, etc\n"
99 " cores= number of CPU cores on one socket\n"
100 " threads= number of threads on one CPU core\n"
101 " sockets= number of discrete sockets in the system\n",
104 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
106 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
107 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
109 For the PC target
, the number of @
var{cores
} per socket
, the number
110 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
111 specified
. Missing values will be computed
. If any on the three values is
112 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
113 specifies the maximum number of hotpluggable CPUs
.
116 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
117 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n"
118 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL
)
120 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
121 @item
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
123 Simulate a multi node NUMA system
. If @samp
{mem
}, @samp
{memdev
}
124 and @samp
{cpus
} are omitted
, resources are split equally
. Also
, note
125 that the
-@option
{numa
} option doesn
't allocate any of the specified
126 resources. That is, it just assigns existing resources to NUMA nodes. This
127 means that one still has to use the @option{-m}, @option{-smp} options
128 to allocate RAM and VCPUs respectively, and possibly @option{-object}
129 to specify the memory backend for the @samp{memdev} suboption.
131 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
132 node uses @samp{memdev}, all of them have to use it.
135 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
136 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
137 " Add 'fd
' to fd 'set
'\n", QEMU_ARCH_ALL)
139 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
142 Add a file descriptor to an fd set. Valid options are:
146 This option defines the file descriptor of which a duplicate is added to fd set.
147 The file descriptor cannot be stdin, stdout, or stderr.
149 This option defines the ID of the fd set to add the file descriptor to.
150 @item opaque=@var{opaque}
151 This option defines a free-form string that can be used to describe @var{fd}.
154 You can open an image using pre-opened file descriptors from an fd set:
157 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
158 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
159 -drive file=/dev/fdset/2,index=0,media=disk
163 DEF("set", HAS_ARG, QEMU_OPTION_set,
164 "-set group.id.arg=value\n"
165 " set <arg> parameter for item <id> of type <group>\n"
166 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
168 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
170 Set parameter @var{arg} for item @var{id} of type @var{group}\n"
173 DEF("global", HAS_ARG, QEMU_OPTION_global,
174 "-global driver.prop=value\n"
175 " set a global default for a driver property\n",
178 @item -global @var{driver}.@var{prop}=@var{value}
180 Set default value of @var{driver}'s property @
var{prop
} to @
var{value
}, e
.g
.:
183 qemu
-system
-i386
-global ide
-drive
.physical_block_size
=4096 -drive file
=file
,if=ide
,index
=0,media
=disk
186 In particular
, you can use
this to set driver properties
for devices which are
187 created automatically by the machine model
. To create a device which is not
188 created automatically and set properties on it
, use
-@option
{device
}.
191 DEF("boot", HAS_ARG
, QEMU_OPTION_boot
,
192 "-boot [order=drives][,once=drives][,menu=on|off]\n"
193 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
194 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
195 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
196 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
197 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
200 @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
]
202 Specify boot order @
var{drives
} as a string of drive letters
. Valid
203 drive letters depend on the target achitecture
. The x86 PC uses
: a
, b
204 (floppy
1 and
2), c (first hard disk
), d (first CD
-ROM
), n
-p (Etherboot
205 from network adapter
1-4), hard disk boot is the
default. To apply a
206 particular boot order only on the first startup
, specify it via
209 Interactive boot menus
/prompts can be enabled via @option
{menu
=on
} as far
210 as firmware
/BIOS supports them
. The
default is non
-interactive boot
.
212 A splash picture could be passed to bios
, enabling user to show it as logo
,
213 when option splash
=@
var{sp_name
} is given and menu
=on
, If firmware
/BIOS
214 supports them
. Currently Seabios
for X86 system support it
.
215 limitation
: The splash file could be a jpeg file or a BMP file
in 24 BPP
216 format(true color
). The resolution should be supported by the SVGA mode
, so
217 the recommended is
320x240
, 640x480
, 800x640
.
219 A timeout could be passed to bios
, guest will pause
for @
var{rb_timeout
} ms
220 when boot failed
, then reboot
. If @
var{rb_timeout
} is
'-1', guest will not
221 reboot
, qemu passes
'-1' to bios by
default. Currently Seabios
for X86
224 Do strict boot via @option
{strict
=on
} as far as firmware
/BIOS
225 supports it
. This only effects when boot priority is changed by
226 bootindex options
. The
default is non
-strict boot
.
229 #
try to boot from network first
, then from hard disk
230 qemu
-system
-i386
-boot order
=nc
231 # boot from CD
-ROM first
, switch back to
default order after reboot
232 qemu
-system
-i386
-boot once
=d
233 # boot with a splash picture
for 5 seconds
.
234 qemu
-system
-i386
-boot menu
=on
,splash
=/root
/boot
.bmp
,splash
-time
=5000
237 Note
: The legacy format
'-boot @var{drives}' is still supported but its
238 use is discouraged as it may be removed from future versions
.
241 DEF("m", HAS_ARG
, QEMU_OPTION_m
,
242 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
243 " configure guest RAM\n"
244 " size: initial amount of guest memory\n"
245 " slots: number of hotplug slots (default: none)\n"
246 " maxmem: maximum amount of guest memory (default: none)\n"
247 "NOTE: Some architectures might enforce a specific granularity\n",
250 @item
-m
[size
=]@
var{megs
}[,slots
=n
,maxmem
=size
]
252 Sets guest startup RAM size to @
var{megs
} megabytes
. Default is
128 MiB
.
253 Optionally
, a suffix of ``M
'' or ``G
'' can be used to signify a value
in
254 megabytes or gigabytes respectively
. Optional pair @
var{slots
}, @
var{maxmem
}
255 could be used to set amount of hotpluggable memory slots and maximum amount of
256 memory
. Note that @
var{maxmem
} must be aligned to the page size
.
258 For example
, the following command
-line sets the guest startup RAM size to
259 1GB
, creates
3 slots to hotplug additional memory and sets the maximum
260 memory the guest can reach to
4GB
:
263 qemu
-system
-x86_64
-m
1G
,slots
=3,maxmem
=4G
266 If @
var{slots
} and @
var{maxmem
} are not specified
, memory hotplug won
't
267 be enabled and the guest startup RAM will never increase.
270 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
271 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
273 @item -mem-path @var{path}
275 Allocate guest RAM from a temporarily created file in @var{path}.
278 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
279 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
283 @findex -mem-prealloc
284 Preallocate memory when using -mem-path.
287 DEF("k", HAS_ARG, QEMU_OPTION_k,
288 "-k language use keyboard layout (for example 'fr
' for French)\n",
291 @item -k @var{language}
293 Use keyboard layout @var{language} (for example @code{fr} for
294 French). This option is only needed where it is not easy to get raw PC
295 keycodes (e.g. on Macs, with some X11 servers or with a VNC
296 display). You don't normally need to use it on PC
/Linux or PC
/Windows
299 The available layouts are
:
301 ar de
-ch es fo fr
-ca hu ja mk no pt
-br sv
302 da en
-gb et fr fr
-ch is lt nl pl ru th
303 de en
-us fi fr
-be hr it lv nl
-be pt sl tr
306 The
default is @code
{en
-us
}.
310 DEF("audio-help", 0, QEMU_OPTION_audio_help
,
311 "-audio-help print list of audio drivers and their options\n",
316 Will show the audio subsystem help
: list of drivers
, tunable
320 DEF("soundhw", HAS_ARG
, QEMU_OPTION_soundhw
,
321 "-soundhw c1,... enable audio support\n"
322 " and only specified sound cards (comma separated list)\n"
323 " use '-soundhw help' to get the list of supported cards\n"
324 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL
)
326 @item
-soundhw @
var{card1
}[,@
var{card2
},...] or
-soundhw all
328 Enable audio and selected sound hardware
. Use
'help' to print all
329 available sound hardware
.
332 qemu
-system
-i386
-soundhw sb16
,adlib disk
.img
333 qemu
-system
-i386
-soundhw es1370 disk
.img
334 qemu
-system
-i386
-soundhw ac97 disk
.img
335 qemu
-system
-i386
-soundhw hda disk
.img
336 qemu
-system
-i386
-soundhw all disk
.img
337 qemu
-system
-i386
-soundhw help
340 Note that Linux
's i810_audio OSS kernel (for AC97) module might
341 require manually specifying clocking.
344 modprobe i810_audio clocking=48000
348 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
349 "-balloon none disable balloon device\n"
350 "-balloon virtio[,addr=str]\n"
351 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
355 Disable balloon device.
356 @item -balloon virtio[,addr=@var{addr}]
357 Enable virtio balloon device (default), optionally with PCI address
361 DEF("device", HAS_ARG, QEMU_OPTION_device,
362 "-device driver[,prop[=value][,...]]\n"
363 " add device (based on driver)\n"
364 " prop=value,... sets driver properties\n"
365 " use '-device help
' to print all possible drivers\n"
366 " use '-device driver
,help
' to print all possible properties\n",
369 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
371 Add device @var{driver}. @var{prop}=@var{value} sets driver
372 properties. Valid properties depend on the driver. To get help on
373 possible drivers and properties, use @code{-device help} and
374 @code{-device @var{driver},help}.
377 DEF("name", HAS_ARG, QEMU_OPTION_name,
378 "-name string1[,process=string2][,debug-threads=on|off]\n"
379 " set the name of the guest\n"
380 " string1 sets the window title and string2 the process name (on Linux)\n"
381 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
382 " NOTE: The thread names are for debugging and not a stable API.\n",
385 @item -name @var{name}
387 Sets the @var{name} of the guest.
388 This name will be displayed in the SDL window caption.
389 The @var{name} will also be used for the VNC server.
390 Also optionally set the top visible process name in Linux.
391 Naming of individual threads can also be enabled on Linux to aid debugging.
394 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
395 "-uuid %08x-%04x-%04x-%04x-%012x\n"
396 " specify machine UUID\n", QEMU_ARCH_ALL)
398 @item -uuid @var{uuid}
408 DEFHEADING(Block device options:)
413 DEF("fda", HAS_ARG, QEMU_OPTION_fda,
414 "-fda/-fdb file use 'file
' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
415 DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
417 @item -fda @var{file}
418 @item -fdb @var{file}
421 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
424 DEF("hda", HAS_ARG, QEMU_OPTION_hda,
425 "-hda/-hdb file use 'file
' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
426 DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
427 DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
428 "-hdc/-hdd file use 'file
' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
429 DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
431 @item -hda @var{file}
432 @item -hdb @var{file}
433 @item -hdc @var{file}
434 @item -hdd @var{file}
439 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
442 DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
443 "-cdrom file use 'file
' as IDE cdrom image (cdrom is ide1 master)\n",
446 @item -cdrom @var{file}
448 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
449 @option{-cdrom} at the same time). You can use the host CD-ROM by
450 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
453 DEF("drive", HAS_ARG, QEMU_OPTION_drive,
454 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
455 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
456 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
457 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
458 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
459 " [,readonly=on|off][,copy-on-read=on|off]\n"
460 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
461 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
462 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
463 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
464 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
465 " [[,iops_size=is]]\n"
466 " use 'file
' as a drive image\n", QEMU_ARCH_ALL)
468 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
471 Define a new drive. Valid options are:
474 @item file=@var{file}
475 This option defines which disk image (@pxref{disk_images}) to use with
476 this drive. If the filename contains comma, you must double it
477 (for instance, "file=my,,file" to use file "my,file").
479 Special files such as iSCSI devices can be specified using protocol
480 specific URLs. See the section for "Device URL Syntax" for more information.
481 @item if=@var{interface}
482 This option defines on which type on interface the drive is connected.
483 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio.
484 @item bus=@var{bus},unit=@var{unit}
485 These options define where is connected the drive by defining the bus number and
487 @item index=@var{index}
488 This option defines where is connected the drive by using an index in the list
489 of available connectors of a given interface type.
490 @item media=@var{media}
491 This option defines the type of the media: disk or cdrom.
492 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
493 These options have the same definition as they have in @option{-hdachs}.
494 @item snapshot=@var{snapshot}
495 @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
496 (see @option{-snapshot}).
497 @item cache=@var{cache}
498 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
500 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
501 @item discard=@var{discard}
502 @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.
503 @item format=@var{format}
504 Specify which disk @var{format} will be used rather than detecting
505 the format. Can be used to specifiy format=raw to avoid interpreting
506 an untrusted format header.
507 @item serial=@var{serial}
508 This option specifies the serial number to assign to the device.
509 @item addr=@var{addr}
510 Specify the controller's PCI
address (if=virtio only
).
511 @item werror
=@
var{action
},rerror
=@
var{action
}
512 Specify which @
var{action
} to take on write and read errors
. Valid actions are
:
513 "ignore" (ignore the error and
try to
continue), "stop" (pause QEMU
),
514 "report" (report the error to the guest
), "enospc" (pause QEMU only
if the
515 host disk is full
; report the error to the guest otherwise
).
516 The
default setting is @option
{werror
=enospc
} and @option
{rerror
=report
}.
518 Open drive @option
{file
} as read
-only
. Guest write attempts will fail
.
519 @item copy
-on
-read
=@
var{copy
-on
-read
}
520 @
var{copy
-on
-read
} is
"on" or
"off" and enables whether to copy read backing
521 file sectors into the image file
.
522 @item detect
-zeroes
=@
var{detect
-zeroes
}
523 @
var{detect
-zeroes
} is
"off", "on" or
"unmap" and enables the automatic
524 conversion of plain zero writes by the OS to driver specific optimized
525 zero write commands
. You may even choose
"unmap" if @
var{discard
} is set
526 to
"unmap" to allow a zero write to be converted to an UNMAP operation
.
529 By
default, the @option
{cache
=writeback
} mode is used
. It will report data
530 writes as completed as soon as the data is present
in the host page cache
.
531 This is safe as long as your guest OS makes sure to correctly flush disk caches
532 where needed
. If your guest OS does not handle volatile disk write caches
533 correctly and your host crashes or loses power
, then the guest may experience
536 For such guests
, you should consider
using @option
{cache
=writethrough
}. This
537 means that the host page cache will be used to read and write data
, but write
538 notification will be sent to the guest only after QEMU has made sure to flush
539 each write to the disk
. Be aware that
this has a major impact on performance
.
541 The host page cache can be avoided entirely with @option
{cache
=none
}. This will
542 attempt to
do disk IO directly to the guest
's memory. QEMU may still perform
543 an internal copy of the data. Note that this is considered a writeback mode and
544 the guest OS must handle the disk write cache correctly in order to avoid data
545 corruption on host crashes.
547 The host page cache can be avoided while only sending write notifications to
548 the guest when the data has been flushed to the disk using
549 @option{cache=directsync}.
551 In case you don't care about data integrity over host failures
, use
552 @option
{cache
=unsafe
}. This option tells QEMU that it
never needs to write any
553 data to the disk but can instead keep things
in cache
. If anything goes wrong
,
554 like your host losing power
, the disk storage getting disconnected accidentally
,
555 etc
. your image will most probably be rendered unusable
. When
using
556 the @option
{-snapshot
} option
, unsafe caching is always used
.
558 Copy
-on
-read avoids accessing the same backing file sectors repeatedly and is
559 useful when the backing file is over a slow network
. By
default copy
-on
-read
562 Instead of @option
{-cdrom
} you can use
:
564 qemu
-system
-i386
-drive file
=file
,index
=2,media
=cdrom
567 Instead of @option
{-hda
}, @option
{-hdb
}, @option
{-hdc
}, @option
{-hdd
}, you can
570 qemu
-system
-i386
-drive file
=file
,index
=0,media
=disk
571 qemu
-system
-i386
-drive file
=file
,index
=1,media
=disk
572 qemu
-system
-i386
-drive file
=file
,index
=2,media
=disk
573 qemu
-system
-i386
-drive file
=file
,index
=3,media
=disk
576 You can open an image
using pre
-opened file descriptors from an fd set
:
579 -add
-fd fd
=3,set
=2,opaque
="rdwr:/path/to/file"
580 -add
-fd fd
=4,set
=2,opaque
="rdonly:/path/to/file"
581 -drive file
=/dev
/fdset
/2,index
=0,media
=disk
584 You can connect a CDROM to the slave of ide0
:
586 qemu
-system
-i386
-drive file
=file
,if=ide
,index
=1,media
=cdrom
589 If you don
't specify the "file=" argument, you define an empty drive:
591 qemu-system-i386 -drive if=ide,index=1,media=cdrom
594 You can connect a SCSI disk with unit ID 6 on the bus #0:
596 qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6
599 Instead of @option{-fda}, @option{-fdb}, you can use:
601 qemu-system-i386 -drive file=file,index=0,if=floppy
602 qemu-system-i386 -drive file=file,index=1,if=floppy
605 By default, @var{interface} is "ide" and @var{index} is automatically
608 qemu-system-i386 -drive file=a -drive file=b"
612 qemu-system-i386 -hda a -hdb b
616 DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
617 "-mtdblock file use 'file
' as on-board Flash memory image\n",
620 @item -mtdblock @var{file}
622 Use @var{file} as on-board Flash memory image.
625 DEF("sd", HAS_ARG, QEMU_OPTION_sd,
626 "-sd file use 'file
' as SecureDigital card image\n", QEMU_ARCH_ALL)
630 Use @var{file} as SecureDigital card image.
633 DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
634 "-pflash file use 'file
' as a parallel flash image\n", QEMU_ARCH_ALL)
636 @item -pflash @var{file}
638 Use @var{file} as a parallel flash image.
641 DEF("snapshot", 0, QEMU_OPTION_snapshot,
642 "-snapshot write to temporary files instead of disk image files\n",
647 Write to temporary files instead of disk image files. In this case,
648 the raw disk image you use is not written back. You can however force
649 the write back by pressing @key{C-a s} (@pxref{disk_images}).
652 DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
653 "-hdachs c,h,s[,t]\n" \
654 " force hard disk 0 physical geometry and the optional BIOS\n" \
655 " translation (t=none or lba) (usually QEMU can guess them)\n",
658 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
660 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
661 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
662 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
663 all those parameters. This option is useful for old MS-DOS disk
667 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
668 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
669 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
674 @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}]
676 Define a new file system device. Valid options are:
679 This option specifies the fs driver backend to use.
680 Currently "local", "handle" and "proxy" file system drivers are supported.
682 Specifies identifier for this device
683 @item path=@var{path}
684 Specifies the export path for the file system device. Files under
685 this path will be available to the 9p client on the guest.
686 @item security_model=@var{security_model}
687 Specifies the security model to be used for this export path.
688 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
689 In "passthrough" security model, files are stored using the same
690 credentials as they are created on the guest. This requires QEMU
691 to run as root. In "mapped-xattr" security model, some of the file
692 attributes like uid, gid, mode bits and link target are stored as
693 file attributes. For "mapped-file" these attributes are stored in the
694 hidden .virtfs_metadata directory. Directories exported by this security model cannot
695 interact with other unix tools. "none" security model is same as
696 passthrough except the sever won't report failures
if it fails to
697 set file attributes like ownership
. Security model is mandatory
698 only
for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take
699 security model as a parameter.
700 @item writeout=@var{writeout}
701 This is an optional argument. The only supported value is "immediate".
702 This means that host page cache will be used to read and write data but
703 write notification will be sent to the guest only when the data has been
704 reported as written by the storage subsystem.
706 Enables exporting 9p share as a readonly mount for guests. By default
707 read-write access is given.
708 @item socket=@var{socket}
709 Enables proxy filesystem driver to use passed socket file for communicating
710 with virtfs-proxy-helper
711 @item sock_fd=@var{sock_fd}
712 Enables proxy filesystem driver to use passed socket descriptor for
713 communicating with virtfs-proxy-helper. Usually a helper like libvirt
714 will create socketpair and pass one of the fds as sock_fd
717 -fsdev option is used along with -device driver "virtio-9p-pci".
718 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
719 Options for virtio-9p-pci driver are:
722 Specifies the id value specified along with -fsdev option
723 @item mount_tag=@var{mount_tag}
724 Specifies the tag name to be used by the guest to mount this export point
729 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
730 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
731 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
736 @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}]
739 The general form of a Virtual File system pass-through options are:
742 This option specifies the fs driver backend to use.
743 Currently "local", "handle" and "proxy" file system drivers are supported.
745 Specifies identifier for this device
746 @item path=@var{path}
747 Specifies the export path for the file system device. Files under
748 this path will be available to the 9p client on the guest.
749 @item security_model=@var{security_model}
750 Specifies the security model to be used for this export path.
751 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
752 In "passthrough" security model, files are stored using the same
753 credentials as they are created on the guest. This requires QEMU
754 to run as root. In "mapped-xattr" security model, some of the file
755 attributes like uid, gid, mode bits and link target are stored as
756 file attributes. For "mapped-file" these attributes are stored in the
757 hidden .virtfs_metadata directory. Directories exported by this security model cannot
758 interact with other unix tools. "none" security model is same as
759 passthrough except the sever won't report failures
if it fails to
760 set file attributes like ownership
. Security model is mandatory only
761 for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take security
762 model as a parameter.
763 @item writeout=@var{writeout}
764 This is an optional argument. The only supported value is "immediate".
765 This means that host page cache will be used to read and write data but
766 write notification will be sent to the guest only when the data has been
767 reported as written by the storage subsystem.
769 Enables exporting 9p share as a readonly mount for guests. By default
770 read-write access is given.
771 @item socket=@var{socket}
772 Enables proxy filesystem driver to use passed socket file for
773 communicating with virtfs-proxy-helper. Usually a helper like libvirt
774 will create socketpair and pass one of the fds as sock_fd
776 Enables proxy filesystem driver to use passed 'sock_fd
' as the socket
777 descriptor for interfacing with virtfs-proxy-helper
781 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
782 "-virtfs_synth Create synthetic file system image\n",
786 @findex -virtfs_synth
787 Create synthetic file system image
795 DEFHEADING(USB options:)
800 DEF("usb", 0, QEMU_OPTION_usb,
801 "-usb enable the USB driver (will be the default soon)\n",
806 Enable the USB driver (will be the default soon)
809 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
810 "-usbdevice name add the host or guest USB device 'name
'\n",
814 @item -usbdevice @var{devname}
816 Add the USB device @var{devname}. @xref{usb_devices}.
821 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
824 Pointer device that uses absolute coordinates (like a touchscreen). This
825 means QEMU is able to report the mouse position without having to grab the
826 mouse. Also overrides the PS/2 mouse emulation when activated.
828 @item disk:[format=@var{format}]:@var{file}
829 Mass storage device based on file. The optional @var{format} argument
830 will be used rather than detecting the format. Can be used to specifiy
831 @code{format=raw} to avoid interpreting an untrusted format header.
833 @item host:@var{bus}.@var{addr}
834 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
836 @item host:@var{vendor_id}:@var{product_id}
837 Pass through the host device identified by @var{vendor_id}:@var{product_id}
840 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
841 Serial converter to host character device @var{dev}, see @code{-serial} for the
845 Braille device. This will use BrlAPI to display the braille output on a real
848 @item net:@var{options}
849 Network adapter that supports CDC ethernet and RNDIS protocols.
859 DEFHEADING(Display options:)
864 DEF("display", HAS_ARG, QEMU_OPTION_display,
865 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
866 " [,window_close=on|off]|curses|none|\n"
867 " gtk[,grab_on_hover=on|off]|\n"
868 " vnc=<display>[,<optargs>]\n"
869 " select display type\n", QEMU_ARCH_ALL)
871 @item -display @var{type}
873 Select type of display to use. This option is a replacement for the
874 old style -sdl/-curses/... options. Valid values for @var{type} are
877 Display video output via SDL (usually in a separate graphics
878 window; see the SDL documentation for other possibilities).
880 Display video output via curses. For graphics device models which
881 support a text mode, QEMU can display this output using a
882 curses/ncurses interface. Nothing is displayed when the graphics
883 device is in graphical mode or if the graphics device does not support
884 a text mode. Generally only the VGA device models support text mode.
886 Do not display video output. The guest will still see an emulated
887 graphics card, but its output will not be displayed to the QEMU
888 user. This option differs from the -nographic option in that it
889 only affects what is done with video output; -nographic also changes
890 the destination of the serial and parallel port data.
892 Display video output in a GTK window. This interface provides drop-down
893 menus and other UI elements to configure and control the VM during
896 Start a VNC server on display <arg>
900 DEF("nographic", 0, QEMU_OPTION_nographic,
901 "-nographic disable graphical output and redirect serial I/Os to console\n",
906 Normally, QEMU uses SDL to display the VGA output. With this option,
907 you can totally disable graphical output so that QEMU is a simple
908 command line application. The emulated serial port is redirected on
909 the console and muxed with the monitor (unless redirected elsewhere
910 explicitly). Therefore, you can still use QEMU to debug a Linux kernel
911 with a serial console. Use @key{C-a h} for help on switching between
912 the console and monitor.
915 DEF("curses", 0, QEMU_OPTION_curses,
916 "-curses use a curses/ncurses interface instead of SDL\n",
921 Normally, QEMU uses SDL to display the VGA output. With this option,
922 QEMU can display the VGA output when in text mode using a
923 curses/ncurses interface. Nothing is displayed in graphical mode.
926 DEF("no-frame", 0, QEMU_OPTION_no_frame,
927 "-no-frame open SDL window without a frame and window decorations\n",
932 Do not use decorations for SDL windows and start them using the whole
933 available screen space. This makes the using QEMU in a dedicated desktop
934 workspace more convenient.
937 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
938 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
943 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
944 affects the special keys (for fullscreen, monitor-mode switching, etc).
947 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
948 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
953 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
954 affects the special keys (for fullscreen, monitor-mode switching, etc).
957 DEF("no-quit", 0, QEMU_OPTION_no_quit,
958 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
962 Disable SDL window close capability.
965 DEF("sdl", 0, QEMU_OPTION_sdl,
966 "-sdl enable SDL\n", QEMU_ARCH_ALL)
973 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
974 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
975 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
976 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
977 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
978 " [,tls-ciphers=<list>]\n"
979 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
980 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
981 " [,sasl][,password=<secret>][,disable-ticketing]\n"
982 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
983 " [,jpeg-wan-compression=[auto|never|always]]\n"
984 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
985 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
986 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
987 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
989 " at least one of {port, tls-port} is mandatory\n",
992 @item -spice @var{option}[,@var{option}[,...]]
994 Enable the spice remote desktop protocol. Valid options are
999 Set the TCP port spice is listening on for plaintext channels.
1002 Set the IP address spice is listening on. Default is any address.
1007 Force using the specified IP version.
1009 @item password=<secret>
1010 Set the password you need to authenticate.
1013 Require that the client use SASL to authenticate with the spice.
1014 The exact choice of authentication method used is controlled from the
1015 system / user's SASL configuration file
for the
'qemu' service
. This
1016 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
1017 unprivileged user
, an environment variable SASL_CONF_PATH can be used
1018 to make it search alternate locations
for the service config
.
1019 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
1020 it is recommended that SASL always be combined with the
'tls' and
1021 'x509' settings to enable use of SSL and server certificates
. This
1022 ensures a data encryption preventing compromise of authentication
1025 @item disable
-ticketing
1026 Allow client connects without authentication
.
1028 @item disable
-copy
-paste
1029 Disable copy paste between the client and the guest
.
1031 @item disable
-agent
-file
-xfer
1032 Disable spice
-vdagent based file
-xfer between the client and the guest
.
1035 Set the TCP port spice is listening on
for encrypted channels
.
1037 @item x509
-dir
=<dir
>
1038 Set the x509 file directory
. Expects same filenames as
-vnc $display
,x509
=$dir
1040 @item x509
-key
-file
=<file
>
1041 @item x509
-key
-password
=<file
>
1042 @item x509
-cert
-file
=<file
>
1043 @item x509
-cacert
-file
=<file
>
1044 @item x509
-dh
-key
-file
=<file
>
1045 The x509 file names can also be configured individually
.
1047 @item tls
-ciphers
=<list
>
1048 Specify which ciphers to use
.
1050 @item tls
-channel
=[main|display|cursor|inputs|record|playback
]
1051 @item plaintext
-channel
=[main|display|cursor|inputs|record|playback
]
1052 Force specific channel to be used with or without TLS encryption
. The
1053 options can be specified multiple times to configure multiple
1054 channels
. The special name
"default" can be used to set the
default
1055 mode
. For channels which are not explicitly forced into one mode the
1056 spice client is allowed to pick tls
/plaintext as he pleases
.
1058 @item image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]
1059 Configure image
compression (lossless
).
1060 Default is auto_glz
.
1062 @item jpeg
-wan
-compression
=[auto|
never|always
]
1063 @item zlib
-glz
-wan
-compression
=[auto|
never|always
]
1064 Configure wan image
compression (lossy
for slow links
).
1067 @item streaming
-video
=[off|all|filter
]
1068 Configure video stream detection
. Default is filter
.
1070 @item agent
-mouse
=[on|off
]
1071 Enable
/disable passing mouse events via vdagent
. Default is on
.
1073 @item playback
-compression
=[on|off
]
1074 Enable
/disable audio stream
compression (using celt
0.5.1). Default is on
.
1076 @item seamless
-migration
=[on|off
]
1077 Enable
/disable spice seamless migration
. Default is off
.
1082 DEF("portrait", 0, QEMU_OPTION_portrait
,
1083 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1088 Rotate graphical output
90 deg
left (only PXA LCD
).
1091 DEF("rotate", HAS_ARG
, QEMU_OPTION_rotate
,
1092 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1095 @item
-rotate @
var{deg
}
1097 Rotate graphical output some deg
left (only PXA LCD
).
1100 DEF("vga", HAS_ARG
, QEMU_OPTION_vga
,
1101 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|none]\n"
1102 " select video card type\n", QEMU_ARCH_ALL
)
1104 @item
-vga @
var{type
}
1106 Select type of VGA card to emulate
. Valid values
for @
var{type
} are
1109 Cirrus Logic GD5446 Video card
. All Windows versions starting from
1110 Windows
95 should recognize and use
this graphic card
. For optimal
1111 performances
, use
16 bit color depth
in the guest and the host OS
.
1112 (This one is the
default)
1114 Standard VGA card with Bochs VBE extensions
. If your guest OS
1115 supports the VESA
2.0 VBE
extensions (e
.g
. Windows XP
) and
if you want
1116 to use high resolution
modes (>= 1280x1024x16
) then you should use
1119 VMWare SVGA
-II compatible adapter
. Use it
if you have sufficiently
1120 recent XFree86
/XOrg server or Windows guest with a driver
for this
1123 QXL paravirtual graphic card
. It is VGA
compatible (including VESA
1124 2.0 VBE support
). Works best with qxl guest drivers installed though
.
1125 Recommended choice when
using the spice protocol
.
1127 (sun4m only
) Sun TCX framebuffer
. This is the
default framebuffer
for
1128 sun4m machines and offers both
8-bit and
24-bit colour depths at a
1129 fixed resolution of
1024x768
.
1131 (sun4m only
) Sun cgthree framebuffer
. This is a simple
8-bit framebuffer
1132 for sun4m machines available
in both
1024x768 (OpenBIOS
) and
1152x900 (OBP
)
1133 resolutions aimed at people wishing to run older Solaris versions
.
1139 DEF("full-screen", 0, QEMU_OPTION_full_screen
,
1140 "-full-screen start in full screen\n", QEMU_ARCH_ALL
)
1143 @findex
-full
-screen
1144 Start
in full screen
.
1147 DEF("g", 1, QEMU_OPTION_g
,
1148 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1149 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
1151 @item
-g @
var{width
}x@
var{height
}[x@
var{depth
}]
1153 Set the initial graphical resolution and
depth (PPC
, SPARC only
).
1156 DEF("vnc", HAS_ARG
, QEMU_OPTION_vnc
,
1157 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL
)
1159 @item
-vnc @
var{display
}[,@
var{option
}[,@
var{option
}[,...]]]
1161 Normally
, QEMU uses SDL to display the VGA output
. With
this option
,
1162 you can have QEMU listen on VNC display @
var{display
} and redirect the VGA
1163 display over the VNC session
. It is very useful to enable the usb
1164 tablet device when
using this option (option @option
{-usbdevice
1165 tablet
}). When
using the VNC display
, you must use the @option
{-k
}
1166 parameter to set the keyboard layout
if you are not
using en
-us
. Valid
1167 syntax
for the @
var{display
} is
1171 @item @
var{host
}:@
var{d
}
1173 TCP connections will only be allowed from @
var{host
} on display @
var{d
}.
1174 By convention the TCP port is
5900+@
var{d
}. Optionally
, @
var{host
} can
1175 be omitted
in which
case the server will accept connections from any host
.
1177 @item unix
:@
var{path
}
1179 Connections will be allowed over UNIX domain sockets where @
var{path
} is the
1180 location of a unix socket to listen
for connections on
.
1184 VNC is initialized but not started
. The monitor @code
{change
} command
1185 can be used to later start the VNC server
.
1189 Following the @
var{display
} value there may be one or more @
var{option
} flags
1190 separated by commas
. Valid options are
1196 Connect to a listening VNC client via a ``reverse
'' connection
. The
1197 client is specified by the @
var{display
}. For reverse network
1198 connections (@
var{host
}:@
var{d
},@code
{reverse
}), the @
var{d
} argument
1199 is a TCP port number
, not a display number
.
1203 Opens an additional TCP listening port dedicated to VNC Websocket connections
.
1204 By definition the Websocket port is
5700+@
var{display
}. If @
var{host
} is
1205 specified connections will only be allowed from
this host
.
1206 As an alternative the Websocket port could be specified by
using
1207 @code
{websocket
}=@
var{port
}.
1208 TLS encryption
for the Websocket connection is supported
if the required
1209 certificates are specified with the VNC option @option
{x509
}.
1213 Require that password based authentication is used
for client connections
.
1215 The password must be set separately
using the @code
{set_password
} command
in
1216 the @ref
{pcsys_monitor
}. The syntax to change your password is
:
1217 @code
{set_password
<protocol
> <password
>} where
<protocol
> could be either
1220 If you would like to change
<protocol
> password expiration
, you should use
1221 @code
{expire_password
<protocol
> <expiration
-time
>} where expiration time could
1222 be one of the following options
: now
, never, +seconds or UNIX time of
1223 expiration
, e
.g
. +60 to make password expire
in 60 seconds
, or
1335196800
1224 to make password expire on
"Mon Apr 23 12:00:00 EDT 2012" (UNIX time
for this
1227 You can also use keywords
"now" or
"never" for the expiration time to
1228 allow
<protocol
> password to expire immediately or
never expire
.
1232 Require that client use TLS when communicating with the VNC server
. This
1233 uses anonymous TLS credentials so is susceptible to a man
-in-the
-middle
1234 attack
. It is recommended that
this option be combined with either the
1235 @option
{x509
} or @option
{x509verify
} options
.
1237 @item x509
=@
var{/path
/to
/certificate
/dir
}
1239 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1240 for negotiating the TLS session
. The server will send its x509 certificate
1241 to the client
. It is recommended that a password be set on the VNC server
1242 to provide authentication of the client when
this is used
. The path following
1243 this option specifies where the x509 certificates are to be loaded from
.
1244 See the @ref
{vnc_security
} section
for details on generating certificates
.
1246 @item x509verify
=@
var{/path
/to
/certificate
/dir
}
1248 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1249 for negotiating the TLS session
. The server will send its x509 certificate
1250 to the client
, and request that the client send its own x509 certificate
.
1251 The server will validate the client
's certificate against the CA certificate,
1252 and reject clients when validation fails. If the certificate authority is
1253 trusted, this is a sufficient authentication mechanism. You may still wish
1254 to set a password on the VNC server as a second authentication layer. The
1255 path following this option specifies where the x509 certificates are to
1256 be loaded from. See the @ref{vnc_security} section for details on generating
1261 Require that the client use SASL to authenticate with the VNC server.
1262 The exact choice of authentication method used is controlled from the
1263 system / user's SASL configuration file
for the
'qemu' service
. This
1264 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
1265 unprivileged user
, an environment variable SASL_CONF_PATH can be used
1266 to make it search alternate locations
for the service config
.
1267 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
1268 it is recommended that SASL always be combined with the
'tls' and
1269 'x509' settings to enable use of SSL and server certificates
. This
1270 ensures a data encryption preventing compromise of authentication
1271 credentials
. See the @ref
{vnc_security
} section
for details on
using
1272 SASL authentication
.
1276 Turn on access control lists
for checking of the x509 client certificate
1277 and SASL party
. For x509 certs
, the ACL check is made against the
1278 certificate
's distinguished name. This is something that looks like
1279 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1280 made against the username, which depending on the SASL plugin, may
1281 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1282 When the @option{acl} flag is set, the initial access list will be
1283 empty, with a @code{deny} policy. Thus no one will be allowed to
1284 use the VNC server until the ACLs have been loaded. This can be
1285 achieved using the @code{acl} monitor command.
1289 Enable lossy compression methods (gradient, JPEG, ...). If this
1290 option is set, VNC client may receive lossy framebuffer updates
1291 depending on its encoding settings. Enabling this option can save
1292 a lot of bandwidth at the expense of quality.
1296 Disable adaptive encodings. Adaptive encodings are enabled by default.
1297 An adaptive encoding will try to detect frequently updated screen regions,
1298 and send updates in these regions using a lossy encoding (like JPEG).
1299 This can be really helpful to save bandwidth when playing videos. Disabling
1300 adaptive encodings restores the original static behavior of encodings
1303 @item share=[allow-exclusive|force-shared|ignore]
1305 Set display sharing policy. 'allow
-exclusive
' allows clients to ask
1306 for exclusive access. As suggested by the rfb spec this is
1307 implemented by dropping other connections. Connecting multiple
1308 clients in parallel requires all clients asking for a shared session
1309 (vncviewer: -shared switch). This is the default. 'force
-shared
'
1310 disables exclusive client access. Useful for shared desktop sessions,
1311 where you don't want someone forgetting specify
-shared disconnect
1312 everybody
else. 'ignore' completely ignores the shared flag and
1313 allows everybody connect unconditionally
. Doesn
't conform to the rfb
1314 spec but is traditional QEMU behavior.
1322 ARCHHEADING(, QEMU_ARCH_I386)
1324 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1329 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1330 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1335 Use it when installing Windows 2000 to avoid a disk full bug. After
1336 Windows 2000 is installed, you no longer need this option (this option
1337 slows down the IDE transfers).
1340 HXCOMM Deprecated by -rtc
1341 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1343 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1344 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1347 @item -no-fd-bootchk
1348 @findex -no-fd-bootchk
1349 Disable boot signature checking for floppy disks in BIOS. May
1350 be needed to boot from old floppy disks.
1353 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1354 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1358 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1359 it if your guest OS complains about ACPI problems (PC target machine
1363 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1364 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1368 Disable HPET support.
1371 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1372 "-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"
1373 " ACPI table description\n", QEMU_ARCH_I386)
1375 @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}]...]
1377 Add ACPI table with specified header fields and context from specified files.
1378 For file=, take whole ACPI table from the specified files, including all
1379 ACPI headers (possible overridden by other options).
1380 For data=, only data
1381 portion of the table is used, all header information is specified in the
1385 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1386 "-smbios file=binary\n"
1387 " load SMBIOS entry from binary file\n"
1388 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1390 " specify SMBIOS type 0 fields\n"
1391 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1392 " [,uuid=uuid][,sku=str][,family=str]\n"
1393 " specify SMBIOS type 1 fields\n"
1394 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1395 " [,asset=str][,location=str]\n"
1396 " specify SMBIOS type 2 fields\n"
1397 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1399 " specify SMBIOS type 3 fields\n"
1400 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1401 " [,asset=str][,part=str]\n"
1402 " specify SMBIOS type 4 fields\n"
1403 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1404 " [,asset=str][,part=str][,speed=%d]\n"
1405 " specify SMBIOS type 17 fields\n",
1408 @item -smbios file=@var{binary}
1410 Load SMBIOS entry from binary file.
1412 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1413 Specify SMBIOS type 0 fields
1415 @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}]
1416 Specify SMBIOS type 1 fields
1418 @item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}][,family=@var{str}]
1419 Specify SMBIOS type 2 fields
1421 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1422 Specify SMBIOS type 3 fields
1424 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1425 Specify SMBIOS type 4 fields
1427 @item -smbios type=17[,loc_pfx=@var{str}][,bank=@var{str}][,manufacturer=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}][,speed=@var{%d}]
1428 Specify SMBIOS type 17 fields
1436 DEFHEADING(Network options:)
1441 HXCOMM Legacy slirp options (now moved to -net user):
1443 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1444 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1445 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1447 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1451 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1453 "-netdev user,id=str[,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
1454 " [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n"
1455 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1457 "[,smb=dir[,smbserver=addr]]\n"
1459 " configure a user mode network backend with ID 'str
',\n"
1460 " its DHCP server and optional services\n"
1463 "-netdev tap,id=str,ifname=name\n"
1464 " configure a host TAP network backend with ID 'str
'\n"
1466 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1467 " [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1468 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1469 " configure a host TAP network backend with ID 'str
'\n"
1470 " use network scripts 'file
' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1471 " to configure it and 'dfile
' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1472 " to deconfigure it\n"
1473 " use '[down
]script
=no
' to disable script execution\n"
1474 " use network helper 'helper
' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1476 " use 'fd
=h
' to connect to an already opened TAP interface\n"
1477 " use 'fds
=x
:y
:...:z
' to connect to already opened multiqueue capable TAP interfaces\n"
1478 " use 'sndbuf
=nbytes
' to limit the size of the send buffer (the\n"
1479 " default is disabled 'sndbuf
=0' to enable flow control set 'sndbuf
=1048576')\n"
1480 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1481 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1482 " use vhost=on to enable experimental in kernel accelerator\n"
1483 " (only has effect for virtio guests which use MSIX)\n"
1484 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1485 " use 'vhostfd
=h
' to connect to an already opened vhost net device\n"
1486 " use 'vhostfds
=x
:y
:...:z to connect to multiple already opened vhost net devices
\n"
1487 " use
'queues=n' to specify the number of queues to be created
for multiqueue TAP
\n"
1488 "-netdev bridge
,id
=str
[,br
=bridge
][,helper
=helper
]\n"
1489 " configure a host TAP network backend with ID
'str' that is
\n"
1490 " connected to a
bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1491 " using the program
'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1494 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1495 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1496 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1497 " [,rxcookie=rxcookie][,offset=offset]\n"
1498 " configure a network backend with ID 'str
' connected to\n"
1499 " an Ethernet over L2TPv3 pseudowire.\n"
1500 " Linux kernel 3.3+ as well as most routers can talk\n"
1501 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1502 " VM to a router and even VM to Host. It is a nearly-universal\n"
1503 " standard (RFC3391). Note - this implementation uses static\n"
1504 " pre-configured tunnels (same as the Linux kernel).\n"
1505 " use 'src
=' to specify source address\n"
1506 " use 'dst
=' to specify destination address\n"
1507 " use 'udp
=on
' to specify udp encapsulation\n"
1508 " use 'srcport
=' to specify source udp port\n"
1509 " use 'dstport
=' to specify destination udp port\n"
1510 " use 'ipv6
=on
' to force v6\n"
1511 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1512 " well as a weak security measure\n"
1513 " use 'rxcookie
=0x012345678' to specify a rxcookie\n"
1514 " use 'txcookie
=0x012345678' to specify a txcookie\n"
1515 " use 'cookie64
=on
' to set cookie size to 64 bit, otherwise 32\n"
1516 " use 'counter
=off
' to force a 'cut
-down
' L2TPv3 with no counter\n"
1517 " use 'pincounter
=on
' to work around broken counter handling in peer\n"
1518 " use 'offset
=X
' to add an extra offset between header and data\n"
1520 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1521 " configure a network backend to connect to another network\n"
1522 " using a socket connection\n"
1523 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1524 " configure a network backend to connect to a multicast maddr and port\n"
1525 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1526 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1527 " configure a network backend to connect to another network\n"
1528 " using an UDP tunnel\n"
1530 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1531 " configure a network backend to connect to port 'n
' of a vde switch\n"
1532 " running on host and listening for incoming connections on 'socketpath
'.\n"
1533 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1534 " ownership and permissions for communication port.\n"
1536 #ifdef CONFIG_NETMAP
1537 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1538 " attach to the existing netmap-enabled network interface 'name
', or to a\n"
1539 " VALE port (created on the fly) called 'name
' ('nmname
' is name of the \n"
1540 " netmap device, defaults to '/dev
/netmap
')\n"
1542 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1543 " configure a vhost-user network, backed by a chardev 'dev
'\n"
1544 "-netdev hubport,id=str,hubid=n\n"
1545 " configure a hub port on QEMU VLAN 'n
'\n", QEMU_ARCH_ALL)
1546 DEF("net", HAS_ARG, QEMU_OPTION_net,
1547 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1548 " old way to create a new NIC and connect it to VLAN 'n
'\n"
1549 " (use the '-device devtype
,netdev
=str
' option if possible instead)\n"
1550 "-net dump[,vlan=n][,file=f][,len=n]\n"
1551 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
1552 "-net none use it alone to have zero network devices. If no -net option\n"
1553 " is provided, the default is '-net nic
-net user
'\n"
1563 #ifdef CONFIG_NETMAP
1566 "socket][,vlan=n][,option][,option][,...]\n"
1567 " old way to initialize a host network interface\n"
1568 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
1570 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1572 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1573 = 0 is the default). The NIC is an e1000 by default on the PC
1574 target. Optionally, the MAC address can be changed to @var{mac}, the
1575 device address set to @var{addr} (PCI cards only),
1576 and a @var{name} can be assigned for use in monitor commands.
1577 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1578 that the card should have; this option currently only affects virtio cards; set
1579 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1580 NIC is created. QEMU can emulate several different models of network card.
1581 Valid values for @var{type} are
1582 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1583 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1584 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1585 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1586 for a list of available devices for your target.
1588 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1590 @item -net user[,@var{option}][,@var{option}][,...]
1591 Use the user mode network stack which requires no administrator
1592 privilege to run. Valid options are:
1596 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1599 @item name=@var{name}
1600 Assign symbolic name for use in monitor commands.
1602 @item net=@var{addr}[/@var{mask}]
1603 Set IP network address the guest will see. Optionally specify the netmask,
1604 either in the form a.b.c.d or as number of valid top-most bits. Default is
1607 @item host=@var{addr}
1608 Specify the guest-visible address of the host. Default is the 2nd IP in the
1609 guest network, i.e. x.x.x.2.
1611 @item restrict=on|off
1612 If this option is enabled, the guest will be isolated, i.e. it will not be
1613 able to contact the host and no guest IP packets will be routed over the host
1614 to the outside. This option does not affect any explicitly set forwarding rules.
1616 @item hostname=@var{name}
1617 Specifies the client hostname reported by the built-in DHCP server.
1619 @item dhcpstart=@var{addr}
1620 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1621 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1623 @item dns=@var{addr}
1624 Specify the guest-visible address of the virtual nameserver. The address must
1625 be different from the host address. Default is the 3rd IP in the guest network,
1628 @item dnssearch=@var{domain}
1629 Provides an entry for the domain-search list sent by the built-in
1630 DHCP server. More than one domain suffix can be transmitted by specifying
1631 this option multiple times. If supported, this will cause the guest to
1632 automatically try to append the given domain suffix(es) in case a domain name
1633 can not be resolved.
1637 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1640 @item tftp=@var{dir}
1641 When using the user mode network stack, activate a built-in TFTP
1642 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1643 The TFTP client on the guest must be configured in binary mode (use the command
1644 @code{bin} of the Unix TFTP client).
1646 @item bootfile=@var{file}
1647 When using the user mode network stack, broadcast @var{file} as the BOOTP
1648 filename. In conjunction with @option{tftp}, this can be used to network boot
1649 a guest from a local directory.
1651 Example (using pxelinux):
1653 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1656 @item smb=@var{dir}[,smbserver=@var{addr}]
1657 When using the user mode network stack, activate a built-in SMB
1658 server so that Windows OSes can access to the host files in @file{@var{dir}}
1659 transparently. The IP address of the SMB server can be set to @var{addr}. By
1660 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1662 In the guest Windows OS, the line:
1666 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1667 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1669 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1671 Note that a SAMBA server must be installed on the host OS.
1672 QEMU was tested successfully with smbd versions from Red Hat 9,
1673 Fedora Core 3 and OpenSUSE 11.x.
1675 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1676 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1677 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1678 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1679 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1680 be bound to a specific host interface. If no connection type is set, TCP is
1681 used. This option can be given multiple times.
1683 For example, to redirect host X11 connection from screen 1 to guest
1684 screen 0, use the following:
1688 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1689 # this host xterm should open in the guest X11 server
1693 To redirect telnet connections from host port 5555 to telnet port on
1694 the guest, use the following:
1698 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1699 telnet localhost 5555
1702 Then when you use on the host @code{telnet localhost 5555}, you
1703 connect to the guest telnet server.
1705 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1706 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1707 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1708 to the character device @var{dev} or to a program executed by @var{cmd:command}
1709 which gets spawned for each connection. This option can be given multiple times.
1711 You can either use a chardev directly and have that one used throughout QEMU's
1712 lifetime
, like
in the following example
:
1715 # open
10.10.1.1:4321 on bootup
, connect
10.0.2.100:1234 to it whenever
1716 # the guest accesses it
1717 qemu
-net user
,guestfwd
=tcp
:10.0.2.100:1234-tcp
:10.10.1.1:4321 [...]
1720 Or you can execute a command on every TCP connection established by the guest
,
1721 so that QEMU behaves similar to an inetd process
for that virtual server
:
1724 # call
"netcat 10.10.1.1 4321" on every TCP connection to
10.0.2.100:1234
1725 # and connect the TCP stream to its stdin
/stdout
1726 qemu
-net
'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1731 Note
: Legacy stand
-alone options
-tftp
, -bootp
, -smb and
-redir are still
1732 processed and applied to
-net user
. Mixing them with the
new configuration
1733 syntax gives undefined results
. Their use
for new applications is discouraged
1734 as they will be removed from future versions
.
1736 @item
-netdev tap
,id
=@
var{id
}[,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1737 @item
-net tap
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1738 Connect the host TAP network
interface @
var{name
} to VLAN @
var{n
}.
1740 Use the network script @
var{file
} to configure it and the network script
1741 @
var{dfile
} to deconfigure it
. If @
var{name
} is not provided
, the OS
1742 automatically provides one
. The
default network configure script is
1743 @file
{/etc
/qemu
-ifup
} and the
default network deconfigure script is
1744 @file
{/etc
/qemu
-ifdown
}. Use @option
{script
=no
} or @option
{downscript
=no
}
1745 to disable script execution
.
1747 If running QEMU as an unprivileged user
, use the network helper
1748 @
var{helper
} to configure the TAP
interface. The
default network
1749 helper executable is @file
{/path
/to
/qemu
-bridge
-helper
}.
1751 @option
{fd
}=@
var{h
} can be used to specify the handle of an already
1752 opened host TAP
interface.
1757 #launch a QEMU instance with the
default network script
1758 qemu
-system
-i386 linux
.img
-net nic
-net tap
1762 #launch a QEMU instance with two NICs
, each one connected
1764 qemu
-system
-i386 linux
.img \
1765 -net nic
,vlan
=0 -net tap
,vlan
=0,ifname
=tap0 \
1766 -net nic
,vlan
=1 -net tap
,vlan
=1,ifname
=tap1
1770 #launch a QEMU instance with the
default network helper to
1771 #connect a TAP device to bridge br0
1772 qemu
-system
-i386 linux
.img \
1773 -net nic
-net tap
,"helper=/path/to/qemu-bridge-helper"
1776 @item
-netdev bridge
,id
=@
var{id
}[,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1777 @item
-net bridge
[,vlan
=@
var{n
}][,name
=@
var{name
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1778 Connect a host TAP network
interface to a host bridge device
.
1780 Use the network helper @
var{helper
} to configure the TAP
interface and
1781 attach it to the bridge
. The
default network helper executable is
1782 @file
{/path
/to
/qemu
-bridge
-helper
} and the
default bridge
1783 device is @file
{br0
}.
1788 #launch a QEMU instance with the
default network helper to
1789 #connect a TAP device to bridge br0
1790 qemu
-system
-i386 linux
.img
-net bridge
-net nic
,model
=virtio
1794 #launch a QEMU instance with the
default network helper to
1795 #connect a TAP device to bridge qemubr0
1796 qemu
-system
-i386 linux
.img
-net bridge
,br
=qemubr0
-net nic
,model
=virtio
1799 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1800 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}] [,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1802 Connect the VLAN @
var{n
} to a remote VLAN
in another QEMU virtual
1803 machine
using a TCP socket connection
. If @option
{listen
} is
1804 specified
, QEMU waits
for incoming connections on @
var{port
}
1805 (@
var{host
} is optional
). @option
{connect
} is used to connect to
1806 another QEMU instance
using the @option
{listen
} option
. @option
{fd
}=@
var{h
}
1807 specifies an already opened TCP socket
.
1811 # launch a first QEMU instance
1812 qemu
-system
-i386 linux
.img \
1813 -net nic
,macaddr
=52:54:00:12:34:56 \
1814 -net socket
,listen
=:1234
1815 # connect the VLAN
0 of
this instance to the VLAN
0
1816 # of the first instance
1817 qemu
-system
-i386 linux
.img \
1818 -net nic
,macaddr
=52:54:00:12:34:57 \
1819 -net socket
,connect
=127.0.0.1:1234
1822 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1823 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1825 Create a VLAN @
var{n
} shared with another QEMU virtual
1826 machines
using a UDP multicast socket
, effectively making a bus
for
1827 every QEMU with same multicast address @
var{maddr
} and @
var{port
}.
1831 Several QEMU can be running on different hosts and share same
bus (assuming
1832 correct multicast setup
for these hosts
).
1834 mcast support is compatible with User Mode
Linux (argument @option
{eth@
var{N
}=mcast
}), see
1835 @url
{http
://user-mode-linux.sf.net}.
1837 Use @option
{fd
=h
} to specify an already opened UDP multicast socket
.
1842 # launch one QEMU instance
1843 qemu
-system
-i386 linux
.img \
1844 -net nic
,macaddr
=52:54:00:12:34:56 \
1845 -net socket
,mcast
=230.0.0.1:1234
1846 # launch another QEMU instance on same
"bus"
1847 qemu
-system
-i386 linux
.img \
1848 -net nic
,macaddr
=52:54:00:12:34:57 \
1849 -net socket
,mcast
=230.0.0.1:1234
1850 # launch yet another QEMU instance on same
"bus"
1851 qemu
-system
-i386 linux
.img \
1852 -net nic
,macaddr
=52:54:00:12:34:58 \
1853 -net socket
,mcast
=230.0.0.1:1234
1856 Example (User Mode Linux compat
.):
1858 # launch QEMU
instance (note mcast address selected
1860 qemu-system-i386 linux.img \
1861 -net nic,macaddr=52:54:00:12:34:56 \
1862 -net socket,mcast=239.192.168.1:1102
1864 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1867 Example (send packets from host's
1.2.3.4):
1869 qemu
-system
-i386 linux
.img \
1870 -net nic
,macaddr
=52:54:00:12:34:56 \
1871 -net socket
,mcast
=239.192.168.1:1102,localaddr
=1.2.3.4
1874 @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
}]
1875 @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
}]
1876 Connect VLAN @
var{n
} to L2TPv3 pseudowire
. L2TPv3 (RFC3391
) is a popular
1877 protocol to transport
Ethernet (and other Layer
2) data frames between
1878 two systems
. It is present
in routers
, firewalls and the Linux kernel
1879 (from version
3.3 onwards
).
1881 This transport allows a VM to communicate to another VM
, router or firewall directly
.
1883 @item src
=@
var{srcaddr
}
1884 source
address (mandatory
)
1885 @item dst
=@
var{dstaddr
}
1886 destination
address (mandatory
)
1888 select udp
encapsulation (default is ip
).
1889 @item srcport
=@
var{srcport
}
1891 @item dstport
=@
var{dstport
}
1892 destination udp port
.
1894 force v6
, otherwise defaults to v4
.
1895 @item rxcookie
=@
var{rxcookie
}
1896 @item txcookie
=@
var{txcookie
}
1897 Cookies are a weak form of security
in the l2tpv3 specification
.
1898 Their
function is mostly to prevent misconfiguration
. By
default they are
32
1901 Set cookie size to
64 bit instead of the
default 32
1903 Force a
'cut-down' L2TPv3 with no counter as
in
1904 draft
-mkonstan
-l2tpext
-keyed
-ipv6
-tunnel
-00
1906 Work around broken counter handling
in peer
. This may also help on
1907 networks which have packet reorder
.
1908 @item offset
=@
var{offset
}
1909 Add an extra offset between header and data
1911 For example
, to attach a VM running on host
4.3.2.1 via L2TPv3 to the bridge br
-lan
1912 on the remote Linux host
1.2.3.4:
1914 # Setup tunnel on linux host
using raw ip as encapsulation
1916 ip l2tp add tunnel remote
4.3.2.1 local
1.2.3.4 tunnel_id
1 peer_tunnel_id
1 \
1917 encap udp udp_sport
16384 udp_dport
16384
1918 ip l2tp add session tunnel_id
1 name vmtunnel0 session_id \
1919 0xFFFFFFFF peer_session_id
0xFFFFFFFF
1920 ifconfig vmtunnel0 mtu
1500
1921 ifconfig vmtunnel0 up
1922 brctl addif br
-lan vmtunnel0
1926 # launch QEMU instance
- if your network has reorder or is very lossy add
,pincounter
1928 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
1933 @item
-netdev vde
,id
=@
var{id
}[,sock
=@
var{socketpath
}][,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1934 @item
-net vde
[,vlan
=@
var{n
}][,name
=@
var{name
}][,sock
=@
var{socketpath
}] [,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1935 Connect VLAN @
var{n
} to PORT @
var{n
} of a vde
switch running on host and
1936 listening
for incoming connections on @
var{socketpath
}. Use GROUP @
var{groupname
}
1937 and MODE @
var{octalmode
} to change
default ownership and permissions
for
1938 communication port
. This option is only available
if QEMU has been compiled
1939 with vde support enabled
.
1944 vde_switch
-F
-sock
/tmp
/myswitch
1945 # launch QEMU instance
1946 qemu
-system
-i386 linux
.img
-net nic
-net vde
,sock
=/tmp
/myswitch
1949 @item
-netdev hubport
,id
=@
var{id
},hubid
=@
var{hubid
}
1951 Create a hub port on QEMU
"vlan" @
var{hubid
}.
1953 The hubport netdev lets you connect a NIC to a QEMU
"vlan" instead of a single
1954 netdev
. @code
{-net
} and @code
{-device
} with parameter @option
{vlan
} create the
1955 required hub automatically
.
1957 @item
-netdev vhost
-user
,chardev
=@
var{id
}[,vhostforce
=on|off
][,queues
=n
]
1959 Establish a vhost
-user netdev
, backed by a chardev @
var{id
}. The chardev should
1960 be a unix domain socket backed one
. The vhost
-user uses a specifically defined
1961 protocol to pass vhost ioctl replacement messages to an application on the other
1962 end of the socket
. On non
-MSIX guests
, the feature can be forced with
1963 @
var{vhostforce
}. Use
'queues=@var{n}' to specify the number of queues to
1964 be created
for multiqueue vhost
-user
.
1968 qemu
-m
512 -object memory
-backend
-file
,id
=mem
,size
=512M
,mem
-path
=/hugetlbfs
,share
=on \
1969 -numa node
,memdev
=mem \
1970 -chardev socket
,path
=/path
/to
/socket \
1971 -netdev type
=vhost
-user
,id
=net0
,chardev
=chr0 \
1972 -device virtio
-net
-pci
,netdev
=net0
1975 @item
-net dump
[,vlan
=@
var{n
}][,file
=@
var{file
}][,len
=@
var{len
}]
1976 Dump network traffic on VLAN @
var{n
} to file @
var{file
} (@file
{qemu
-vlan0
.pcap
} by
default).
1977 At most @
var{len
} bytes (64k by
default) per packet are stored
. The file format is
1978 libpcap
, so it can be analyzed with tools such as tcpdump or Wireshark
.
1981 Indicate that no network devices should be configured
. It is used to
1982 override the
default configuration (@option
{-net nic
-net user
}) which
1983 is activated
if no @option
{-net
} options are provided
.
1991 DEFHEADING(Character device options
:)
1994 The general form of a character device option is
:
1998 DEF("chardev", HAS_ARG
, QEMU_OPTION_chardev
,
1999 "-chardev null,id=id[,mux=on|off]\n"
2000 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2001 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (tcp)\n"
2002 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (unix)\n"
2003 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2004 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2005 "-chardev msmouse,id=id[,mux=on|off]\n"
2006 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2008 "-chardev ringbuf,id=id[,size=size]\n"
2009 "-chardev file,id=id,path=path[,mux=on|off]\n"
2010 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
2012 "-chardev console,id=id[,mux=on|off]\n"
2013 "-chardev serial,id=id,path=path[,mux=on|off]\n"
2015 "-chardev pty,id=id[,mux=on|off]\n"
2016 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
2018 #ifdef CONFIG_BRLAPI
2019 "-chardev braille,id=id[,mux=on|off]\n"
2021 #
if defined(__linux__
) ||
defined(__sun__
) ||
defined(__FreeBSD__
) \
2022 ||
defined(__NetBSD__
) ||
defined(__OpenBSD__
) ||
defined(__DragonFly__
)
2023 "-chardev serial,id=id,path=path[,mux=on|off]\n"
2024 "-chardev tty,id=id,path=path[,mux=on|off]\n"
2026 #
if defined(__linux__
) ||
defined(__FreeBSD__
) ||
defined(__DragonFly__
)
2027 "-chardev parallel,id=id,path=path[,mux=on|off]\n"
2028 "-chardev parport,id=id,path=path[,mux=on|off]\n"
2030 #
if defined(CONFIG_SPICE
)
2031 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
2032 "-chardev spiceport,id=id,name=name[,debug=debug]\n"
2038 @item
-chardev @
var{backend
} ,id
=@
var{id
} [,mux
=on|off
] [,@
var{options
}]
2059 The specific backend will determine the applicable options
.
2061 All devices must have an id
, which can be any string up to
127 characters long
.
2062 It is used to uniquely identify
this device
in other command line directives
.
2064 A character device may be used
in multiplexing mode by multiple front
-ends
.
2065 The key sequence of @key
{Control
-a
} and @key
{c
} will rotate the input focus
2066 between attached front
-ends
. Specify @option
{mux
=on
} to enable
this mode
.
2068 Options to each backend are described below
.
2070 @item
-chardev
null ,id
=@
var{id
}
2071 A void device
. This device will not emit any data
, and will drop any data it
2072 receives
. The
null backend does not take any options
.
2074 @item
-chardev socket
,id
=@
var{id
} [@
var{TCP options
} or @
var{unix options
}] [,server
] [,nowait
] [,telnet
] [,reconnect
=@
var{seconds
}]
2076 Create a two
-way stream socket
, which can be either a TCP or a unix socket
. A
2077 unix socket will be created
if @option
{path
} is specified
. Behaviour is
2078 undefined
if TCP options are specified
for a unix socket
.
2080 @option
{server
} specifies that the socket shall be a listening socket
.
2082 @option
{nowait
} specifies that QEMU should not block waiting
for a client to
2083 connect to a listening socket
.
2085 @option
{telnet
} specifies that traffic on the socket should interpret telnet
2088 @option
{reconnect
} sets the timeout
for reconnecting on non
-server sockets when
2089 the remote end goes away
. qemu will delay
this many seconds and then attempt
2090 to reconnect
. Zero disables reconnecting
, and is the
default.
2092 TCP and unix socket options are given below
:
2096 @item TCP options
: port
=@
var{port
} [,host
=@
var{host
}] [,to
=@
var{to
}] [,ipv4
] [,ipv6
] [,nodelay
]
2098 @option
{host
} for a listening socket specifies the local address to be bound
.
2099 For a connecting socket species the remote host to connect to
. @option
{host
} is
2100 optional
for listening sockets
. If not specified it defaults to @code
{0.0.0.0}.
2102 @option
{port
} for a listening socket specifies the local port to be bound
. For a
2103 connecting socket specifies the port on the remote host to connect to
.
2104 @option
{port
} can be given as either a port number or a service name
.
2105 @option
{port
} is required
.
2107 @option
{to
} is only relevant to listening sockets
. If it is specified
, and
2108 @option
{port
} cannot be bound
, QEMU will attempt to bind to subsequent ports up
2109 to and including @option
{to
} until it succeeds
. @option
{to
} must be specified
2112 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2113 If neither is specified the socket may use either protocol
.
2115 @option
{nodelay
} disables the Nagle algorithm
.
2117 @item unix options
: path
=@
var{path
}
2119 @option
{path
} specifies the local path of the unix socket
. @option
{path
} is
2124 @item
-chardev udp
,id
=@
var{id
} [,host
=@
var{host
}] ,port
=@
var{port
} [,localaddr
=@
var{localaddr
}] [,localport
=@
var{localport
}] [,ipv4
] [,ipv6
]
2126 Sends all traffic from the guest to a remote host over UDP
.
2128 @option
{host
} specifies the remote host to connect to
. If not specified it
2129 defaults to @code
{localhost
}.
2131 @option
{port
} specifies the port on the remote host to connect to
. @option
{port
}
2134 @option
{localaddr
} specifies the local address to bind to
. If not specified it
2135 defaults to @code
{0.0.0.0}.
2137 @option
{localport
} specifies the local port to bind to
. If not specified any
2138 available local port will be used
.
2140 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2141 If neither is specified the device may use either protocol
.
2143 @item
-chardev msmouse
,id
=@
var{id
}
2145 Forward QEMU
's emulated msmouse events to the guest. @option{msmouse} does not
2148 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2150 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2153 @option{width} and @option{height} specify the width and height respectively of
2154 the console, in pixels.
2156 @option{cols} and @option{rows} specify that the console be sized to fit a text
2157 console with the given dimensions.
2159 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2161 Create a ring buffer with fixed size @option{size}.
2162 @var{size} must be a power of two, and defaults to @code{64K}).
2164 @item -chardev file ,id=@var{id} ,path=@var{path}
2166 Log all traffic received from the guest to a file.
2168 @option{path} specifies the path of the file to be opened. This file will be
2169 created if it does not already exist, and overwritten if it does. @option{path}
2172 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2174 Create a two-way connection to the guest. The behaviour differs slightly between
2175 Windows hosts and other hosts:
2177 On Windows, a single duplex pipe will be created at
2178 @file{\\.pipe\@option{path}}.
2180 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2181 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2182 received by the guest. Data written by the guest can be read from
2183 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2186 @option{path} forms part of the pipe path as described above. @option{path} is
2189 @item -chardev console ,id=@var{id}
2191 Send traffic from the guest to QEMU's standard output
. @option
{console
} does not
2194 @option
{console
} is only available on Windows hosts
.
2196 @item
-chardev serial
,id
=@
var{id
} ,path
=@option
{path
}
2198 Send traffic from the guest to a serial device on the host
.
2200 On Unix hosts serial will actually accept any tty device
,
2201 not only serial lines
.
2203 @option
{path
} specifies the name of the serial device to open
.
2205 @item
-chardev pty
,id
=@
var{id
}
2207 Create a
new pseudo
-terminal on the host and connect to it
. @option
{pty
} does
2208 not take any options
.
2210 @option
{pty
} is not available on Windows hosts
.
2212 @item
-chardev stdio
,id
=@
var{id
} [,signal
=on|off
]
2213 Connect to standard input and standard output of the QEMU process
.
2215 @option
{signal
} controls
if signals are enabled on the terminal
, that includes
2216 exiting QEMU with the key sequence @key
{Control
-c
}. This option is enabled by
2217 default, use @option
{signal
=off
} to disable it
.
2219 @option
{stdio
} is not available on Windows hosts
.
2221 @item
-chardev braille
,id
=@
var{id
}
2223 Connect to a local BrlAPI server
. @option
{braille
} does not take any options
.
2225 @item
-chardev tty
,id
=@
var{id
} ,path
=@
var{path
}
2227 @option
{tty
} is only available on Linux
, Sun
, FreeBSD
, NetBSD
, OpenBSD and
2228 DragonFlyBSD hosts
. It is an alias
for @option
{serial
}.
2230 @option
{path
} specifies the path to the tty
. @option
{path
} is required
.
2232 @item
-chardev parallel
,id
=@
var{id
} ,path
=@
var{path
}
2233 @item
-chardev parport
,id
=@
var{id
} ,path
=@
var{path
}
2235 @option
{parallel
} is only available on Linux
, FreeBSD and DragonFlyBSD hosts
.
2237 Connect to a local parallel port
.
2239 @option
{path
} specifies the path to the parallel port device
. @option
{path
} is
2242 @item
-chardev spicevmc
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2244 @option
{spicevmc
} is only available when spice support is built
in.
2246 @option
{debug
} debug level
for spicevmc
2248 @option
{name
} name of spice channel to connect to
2250 Connect to a spice virtual machine channel
, such as vdiport
.
2252 @item
-chardev spiceport
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2254 @option
{spiceport
} is only available when spice support is built
in.
2256 @option
{debug
} debug level
for spicevmc
2258 @option
{name
} name of spice port to connect to
2260 Connect to a spice port
, allowing a Spice client to handle the traffic
2261 identified by a
name (preferably a fqdn
).
2269 DEFHEADING(Device URL Syntax
:)
2272 In addition to
using normal file images
for the emulated storage devices
,
2273 QEMU can also use networked resources such as iSCSI devices
. These are
2274 specified
using a special URL syntax
.
2278 iSCSI support allows QEMU to access iSCSI resources directly and use as
2279 images
for the guest storage
. Both disk and cdrom images are supported
.
2281 Syntax
for specifying iSCSI LUNs is
2282 ``iscsi
://<target-ip>[:<port>]/<target-iqn>/<lun>''
2284 By
default qemu will use the iSCSI initiator
-name
2285 'iqn.2008-11.org.linux-kvm[:<name>]' but
this can also be set from the command
2286 line or a configuration file
.
2289 Example (without authentication
):
2291 qemu
-system
-i386
-iscsi initiator
-name
=iqn
.2001-04.com
.example
:my
-initiator \
2292 -cdrom iscsi
://192.0.2.1/iqn.2001-04.com.example/2 \
2293 -drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2296 Example (CHAP username
/password via URL
):
2298 qemu
-system
-i386
-drive file
=iscsi
://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2301 Example (CHAP username
/password via environment variables
):
2303 LIBISCSI_CHAP_USERNAME
="user" \
2304 LIBISCSI_CHAP_PASSWORD
="password" \
2305 qemu
-system
-i386
-drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2308 iSCSI support is an optional feature of QEMU and only available when
2309 compiled and linked against libiscsi
.
2311 DEF("iscsi", HAS_ARG
, QEMU_OPTION_iscsi
,
2312 "-iscsi [user=user][,password=password]\n"
2313 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2314 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2315 " iSCSI session parameters\n", QEMU_ARCH_ALL
)
2318 iSCSI parameters such as username and password can also be specified via
2319 a configuration file
. See qemu
-doc
for more information and examples
.
2322 QEMU supports
NBD (Network Block Devices
) both
using TCP protocol as well
2323 as Unix Domain Sockets
.
2325 Syntax
for specifying a NBD device
using TCP
2326 ``nbd
:<server
-ip
>:<port
>[:exportname
=<export
>]''
2328 Syntax
for specifying a NBD device
using Unix Domain Sockets
2329 ``nbd
:unix
:<domain
-socket
>[:exportname
=<export
>]''
2334 qemu
-system
-i386
--drive file
=nbd
:192.0.2.1:30000
2337 Example
for Unix Domain Sockets
2339 qemu
-system
-i386
--drive file
=nbd
:unix
:/tmp
/nbd
-socket
2343 QEMU supports
SSH (Secure Shell
) access to remote disks
.
2347 qemu
-system
-i386
-drive file
=ssh
://user@@host/path/to/disk.img
2348 qemu
-system
-i386
-drive file
.driver
=ssh
,file
.user
=user
,file
.host
=host
,file
.port
=22,file
.path
=/path
/to
/disk
.img
2351 Currently authentication must be done
using ssh
-agent
. Other
2352 authentication methods may be supported
in future
.
2355 Sheepdog is a distributed storage system
for QEMU
.
2356 QEMU supports
using either local sheepdog devices or remote networked
2359 Syntax
for specifying a sheepdog device
2361 sheepdog
[+tcp|
+unix
]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2366 qemu
-system
-i386
--drive file
=sheepdog
://192.0.2.1:30000/MyVirtualMachine
2369 See also @url
{http
://http://www.osrg.net/sheepdog/}.
2372 GlusterFS is an user space distributed file system
.
2373 QEMU supports the use of GlusterFS volumes
for hosting VM disk images
using
2374 TCP
, Unix Domain Sockets and RDMA transport protocols
.
2376 Syntax
for specifying a VM disk image on GlusterFS volume is
2378 gluster
[+transport
]://[server[:port]]/volname/image[?socket=...]
2384 qemu
-system
-x86_64
--drive file
=gluster
://192.0.2.1/testvol/a.img
2387 See also @url
{http
://www.gluster.org}.
2389 @item HTTP
/HTTPS
/FTP
/FTPS
/TFTP
2390 QEMU supports read
-only access to files accessed over
http(s
), ftp(s
) and tftp
.
2392 Syntax
using a single filename
:
2394 <protocol
>://[<username>[:<password>]@@]<host>/<path>
2400 'http', 'https', 'ftp', 'ftps', or
'tftp'.
2403 Optional username
for authentication to the remote server
.
2406 Optional password
for authentication to the remote server
.
2409 Address of the remote server
.
2412 Path on the remote server
, including any query string
.
2415 The following options are also supported
:
2418 The full URL when passing options to the driver explicitly
.
2421 The amount of data to read ahead with each range request to the remote server
.
2422 This value may optionally have the suffix
'T', 'G', 'M', 'K', 'k' or
'b'. If it
2423 does not have a suffix
, it will be assumed to be
in bytes
. The value must be a
2424 multiple of
512 bytes
. It defaults to
256k
.
2427 Whether to verify the remote server
's certificate when connecting over SSL. It
2428 can have the value 'on
' or 'off
'. It defaults to 'on
'.
2431 Send this cookie (it can also be a list of cookies separated by ';') with
2432 each outgoing request. Only supported when using protocols such as HTTP
2433 which support cookies, otherwise ignored.
2436 Set the timeout in seconds of the CURL connection. This timeout is the time
2437 that CURL waits for a response from the remote server to get the size of the
2438 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2441 Note that when passing options to qemu explicitly, @option{driver} is the value
2444 Example: boot from a remote Fedora 20 live ISO image
2446 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
2448 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
2451 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2452 writes, copy-on-read, and a readahead of 64k
2454 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
2456 qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
2459 Example: boot from an image stored on a VMware vSphere server with a self-signed
2460 certificate using a local overlay for writes, a readahead of 64k and a timeout
2463 qemu-img create -f qcow2 -o backing_file='json
:@
{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@
}' /tmp/test.qcow2
2465 qemu-system-x86_64 -drive file=/tmp/test.qcow2
2473 DEFHEADING(Bluetooth(R) options:)
2478 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2479 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands
\n" \
2480 "-bt hci
,host
[:id
]\n" \
2481 " use host
's HCI with the given name\n" \
2482 "-bt hci[,vlan=n]\n" \
2483 " emulate a standard HCI in virtual scatternet 'n
'\n" \
2484 "-bt vhci[,vlan=n]\n" \
2485 " add host computer to virtual scatternet 'n
' using VHCI\n" \
2486 "-bt device:dev[,vlan=n]\n" \
2487 " emulate a bluetooth device 'dev
' in scatternet 'n
'\n",
2492 Defines the function of the corresponding Bluetooth HCI. -bt options
2493 are matched with the HCIs present in the chosen machine type. For
2494 example when emulating a machine with only one HCI built into it, only
2495 the first @code{-bt hci[...]} option is valid and defines the HCI's
2496 logic
. The Transport Layer is decided by the machine type
. Currently
2497 the machines @code
{n800
} and @code
{n810
} have one HCI and all other
2501 The following three types are recognized
:
2505 (default) The corresponding Bluetooth HCI assumes no internal logic
2506 and will not respond to any HCI commands or emit events
.
2508 @item
-bt hci
,host
[:@
var{id
}]
2509 (@code
{bluez
} only
) The corresponding HCI passes commands
/ events
2510 to
/ from the physical HCI identified by the name @
var{id
} (default:
2511 @code
{hci0
}) on the computer running QEMU
. Only available on @code
{bluez
}
2512 capable systems like Linux
.
2514 @item
-bt hci
[,vlan
=@
var{n
}]
2515 Add a virtual
, standard HCI that will participate
in the Bluetooth
2516 scatternet @
var{n
} (default @code
{0}). Similarly to @option
{-net
}
2517 VLANs
, devices inside a bluetooth network @
var{n
} can only communicate
2518 with other devices
in the same
network (scatternet
).
2521 @item
-bt vhci
[,vlan
=@
var{n
}]
2522 (Linux
-host only
) Create a HCI
in scatternet @
var{n
} (default 0) attached
2523 to the host bluetooth stack instead of to the emulated target
. This
2524 allows the host and target machines to participate
in a common scatternet
2525 and communicate
. Requires the Linux @code
{vhci
} driver installed
. Can
2526 be used as following
:
2529 qemu
-system
-i386
[...OPTIONS
...] -bt hci
,vlan
=5 -bt vhci
,vlan
=5
2532 @item
-bt device
:@
var{dev
}[,vlan
=@
var{n
}]
2533 Emulate a bluetooth device @
var{dev
} and place it
in network @
var{n
}
2534 (default @code
{0}). QEMU can only emulate one type of bluetooth devices
2539 Virtual wireless keyboard implementing the HIDP bluetooth profile
.
2549 DEFHEADING(TPM device options
:)
2551 DEF("tpmdev", HAS_ARG
, QEMU_OPTION_tpmdev
, \
2552 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2553 " use path to provide path to a character device; default is /dev/tpm0\n"
2554 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2555 " not provided it will be searched for in /sys/class/misc/tpm?/device\n",
2559 The general form of a TPM device option is
:
2562 @item
-tpmdev @
var{backend
} ,id
=@
var{id
} [,@
var{options
}]
2564 Backend type must be
:
2565 @option
{passthrough
}.
2567 The specific backend type will determine the applicable options
.
2568 The @code
{-tpmdev
} option creates the TPM backend and requires a
2569 @code
{-device
} option that specifies the TPM frontend
interface model
.
2571 Options to each backend are described below
.
2573 Use
'help' to print all available TPM backend types
.
2578 @item
-tpmdev passthrough
, id
=@
var{id
}, path
=@
var{path
}, cancel
-path
=@
var{cancel
-path
}
2580 (Linux
-host only
) Enable access to the host
's TPM using the passthrough
2583 @option{path} specifies the path to the host's TPM device
, i
.e
., on
2584 a Linux host
this would be @code
{/dev
/tpm0
}.
2585 @option
{path
} is optional and by
default @code
{/dev
/tpm0
} is used
.
2587 @option
{cancel
-path
} specifies the path to the host TPM device
's sysfs
2588 entry allowing for cancellation of an ongoing TPM command.
2589 @option{cancel-path} is optional and by default QEMU will search for the
2592 Some notes about using the host's TPM with the passthrough driver
:
2594 The TPM device accessed by the passthrough driver must not be
2595 used by any other application on the host
.
2597 Since the host
's firmware (BIOS/UEFI) has already initialized the TPM,
2598 the VM's
firmware (BIOS
/UEFI
) will not be able to initialize the
2599 TPM again and may therefore not show a TPM
-specific menu that would
2600 otherwise allow the user to configure the TPM
, e
.g
., allow the user to
2601 enable
/disable or activate
/deactivate the TPM
.
2602 Further
, if TPM ownership is released from within a VM then the host
's TPM
2603 will get disabled and deactivated. To enable and activate the
2604 TPM again afterwards, the host has to be rebooted and the user is
2605 required to enter the firmware's menu to enable and activate the TPM
.
2606 If the TPM is left disabled and
/or deactivated most TPM commands will fail
.
2608 To create a passthrough TPM use the following two options
:
2610 -tpmdev passthrough
,id
=tpm0
-device tpm
-tis
,tpmdev
=tpm0
2612 Note that the @code
{-tpmdev
} id is @code
{tpm0
} and is referenced by
2613 @code
{tpmdev
=tpm0
} in the device option
.
2623 DEFHEADING(Linux
/Multiboot boot specific
:)
2626 When
using these options
, you can use a given Linux or Multiboot
2627 kernel without installing it
in the disk image
. It can be useful
2628 for easier testing of various kernels
.
2633 DEF("kernel", HAS_ARG
, QEMU_OPTION_kernel
, \
2634 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL
)
2636 @item
-kernel @
var{bzImage
}
2638 Use @
var{bzImage
} as kernel image
. The kernel can be either a Linux kernel
2639 or
in multiboot format
.
2642 DEF("append", HAS_ARG
, QEMU_OPTION_append
, \
2643 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL
)
2645 @item
-append @
var{cmdline
}
2647 Use @
var{cmdline
} as kernel command line
2650 DEF("initrd", HAS_ARG
, QEMU_OPTION_initrd
, \
2651 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL
)
2653 @item
-initrd @
var{file
}
2655 Use @
var{file
} as initial ram disk
.
2657 @item
-initrd
"@var{file1} arg=foo,@var{file2}"
2659 This syntax is only available with multiboot
.
2661 Use @
var{file1
} and @
var{file2
} as modules and pass arg
=foo as parameter to the
2665 DEF("dtb", HAS_ARG
, QEMU_OPTION_dtb
, \
2666 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL
)
2668 @item
-dtb @
var{file
}
2670 Use @
var{file
} as a device tree
binary (dtb
) image and pass it to the kernel
2679 DEFHEADING(Debug
/Expert options
:)
2684 DEF("serial", HAS_ARG
, QEMU_OPTION_serial
, \
2685 "-serial dev redirect the serial port to char device 'dev'\n",
2688 @item
-serial @
var{dev
}
2690 Redirect the virtual serial port to host character device
2691 @
var{dev
}. The
default device is @code
{vc
} in graphical mode and
2692 @code
{stdio
} in non graphical mode
.
2694 This option can be used several times to simulate up to
4 serial
2697 Use @code
{-serial none
} to disable all serial ports
.
2699 Available character devices are
:
2701 @item vc
[:@
var{W
}x@
var{H
}]
2702 Virtual console
. Optionally
, a width and height can be given
in pixel with
2706 It is also possible to specify width or height
in characters
:
2711 [Linux only
] Pseudo
TTY (a
new PTY is automatically allocated
)
2713 No device is allocated
.
2716 @item chardev
:@
var{id
}
2717 Use a named character device defined with the @code
{-chardev
} option
.
2719 [Linux only
] Use host tty
, e
.g
. @file
{/dev
/ttyS0
}. The host serial port
2720 parameters are set according to the emulated ones
.
2721 @item
/dev
/parport@
var{N
}
2722 [Linux only
, parallel port only
] Use host parallel port
2723 @
var{N
}. Currently SPP and EPP parallel port features can be used
.
2724 @item file
:@
var{filename
}
2725 Write output to @
var{filename
}. No character can be read
.
2727 [Unix only
] standard input
/output
2728 @item pipe
:@
var{filename
}
2729 name pipe @
var{filename
}
2731 [Windows only
] Use host serial port @
var{n
}
2732 @item udp
:[@
var{remote_host
}]:@
var{remote_port
}[@@
[@
var{src_ip
}]:@
var{src_port
}]
2733 This
implements UDP Net Console
.
2734 When @
var{remote_host
} or @
var{src_ip
} are not specified
2735 they
default to @code
{0.0.0.0}.
2736 When not
using a specified @
var{src_port
} a random port is automatically chosen
.
2738 If you just want a simple readonly console you can use @code
{netcat
} or
2739 @code
{nc
}, by starting QEMU with
: @code
{-serial udp
::4555} and nc as
:
2740 @code
{nc
-u
-l
-p
4555}. Any time QEMU writes something to that port it
2741 will appear
in the netconsole session
.
2743 If you plan to send characters back via netconsole or you want to stop
2744 and start QEMU a lot of times
, you should have QEMU use the same
2745 source port each time by
using something like @code
{-serial
2746 udp
::4555@@
:4556} to QEMU
. Another approach is to use a patched
2747 version of netcat which can listen to a TCP port and send and receive
2748 characters via udp
. If you have a patched version of netcat which
2749 activates telnet remote echo and single char transfer
, then you can
2750 use the following options to step up a netcat redirector to allow
2751 telnet on port
5555 to access the QEMU port
.
2754 -serial udp
::4555@@
:4556
2755 @item netcat options
:
2756 -u
-P
4555 -L
0.0.0.0:4556 -t
-p
5555 -I
-T
2757 @item telnet options
:
2761 @item tcp
:[@
var{host
}]:@
var{port
}[,@
var{server
}][,nowait
][,nodelay
][,reconnect
=@
var{seconds
}]
2762 The TCP Net Console has two modes of operation
. It can send the serial
2763 I
/O to a location or wait
for a connection from a location
. By
default
2764 the TCP Net Console is sent to @
var{host
} at the @
var{port
}. If you use
2765 the @
var{server
} option QEMU will wait
for a client socket application
2766 to connect to the port before continuing
, unless the @code
{nowait
}
2767 option was specified
. The @code
{nodelay
} option disables the Nagle buffering
2768 algorithm
. The @code
{reconnect
} option only applies
if @
var{noserver
} is
2769 set
, if the connection goes down it will attempt to reconnect at the
2770 given interval
. If @
var{host
} is omitted
, 0.0.0.0 is assumed
. Only
2771 one TCP connection at a time is accepted
. You can use @code
{telnet
} to
2772 connect to the corresponding character device
.
2774 @item Example to send tcp console to
192.168.0.2 port
4444
2775 -serial tcp
:192.168.0.2:4444
2776 @item Example to listen and wait on port
4444 for connection
2777 -serial tcp
::4444,server
2778 @item Example to not wait and listen on ip
192.168.0.100 port
4444
2779 -serial tcp
:192.168.0.100:4444,server
,nowait
2782 @item telnet
:@
var{host
}:@
var{port
}[,server
][,nowait
][,nodelay
]
2783 The telnet protocol is used instead of raw tcp sockets
. The options
2784 work the same as
if you had specified @code
{-serial tcp
}. The
2785 difference is that the port acts like a telnet server or client
using
2786 telnet option negotiation
. This will also allow you to send the
2787 MAGIC_SYSRQ sequence
if you use a telnet that supports sending the
break
2788 sequence
. Typically
in unix telnet you
do it with Control
-] and then
2789 type
"send break" followed by pressing the enter key
.
2791 @item unix
:@
var{path
}[,server
][,nowait
][,reconnect
=@
var{seconds
}]
2792 A unix domain socket is used instead of a tcp socket
. The option works the
2793 same as
if you had specified @code
{-serial tcp
} except the unix domain socket
2794 @
var{path
} is used
for connections
.
2796 @item mon
:@
var{dev_string
}
2797 This is a special option to allow the monitor to be multiplexed onto
2798 another serial port
. The monitor is accessed with key sequence of
2799 @key
{Control
-a
} and then pressing @key
{c
}.
2800 @
var{dev_string
} should be any one of the serial devices specified
2801 above
. An example to multiplex the monitor onto a telnet server
2802 listening on port
4444 would be
:
2804 @item
-serial mon
:telnet
::4444,server
,nowait
2806 When the monitor is multiplexed to stdio
in this way
, Ctrl
+C will not terminate
2807 QEMU any more but will be passed to the guest instead
.
2810 Braille device
. This will use BrlAPI to display the braille output on a real
2814 Three button serial mouse
. Configure the guest to use Microsoft protocol
.
2818 DEF("parallel", HAS_ARG
, QEMU_OPTION_parallel
, \
2819 "-parallel dev redirect the parallel port to char device 'dev'\n",
2822 @item
-parallel @
var{dev
}
2824 Redirect the virtual parallel port to host device @
var{dev
} (same
2825 devices as the serial port
). On Linux hosts
, @file
{/dev
/parportN
} can
2826 be used to use hardware devices connected on the corresponding host
2829 This option can be used several times to simulate up to
3 parallel
2832 Use @code
{-parallel none
} to disable all parallel ports
.
2835 DEF("monitor", HAS_ARG
, QEMU_OPTION_monitor
, \
2836 "-monitor dev redirect the monitor to char device 'dev'\n",
2839 @item
-monitor @
var{dev
}
2841 Redirect the monitor to host device @
var{dev
} (same devices as the
2843 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2845 Use @code
{-monitor none
} to disable the
default monitor
.
2847 DEF("qmp", HAS_ARG
, QEMU_OPTION_qmp
, \
2848 "-qmp dev like -monitor but opens in 'control' mode\n",
2851 @item
-qmp @
var{dev
}
2853 Like
-monitor but opens
in 'control' mode
.
2855 DEF("qmp-pretty", HAS_ARG
, QEMU_OPTION_qmp_pretty
, \
2856 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
2859 @item
-qmp
-pretty @
var{dev
}
2861 Like
-qmp but uses pretty JSON formatting
.
2864 DEF("mon", HAS_ARG
, QEMU_OPTION_mon
, \
2865 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL
)
2867 @item
-mon
[chardev
=]name
[,mode
=readline|control
][,default]
2869 Setup monitor on chardev @
var{name
}.
2872 DEF("debugcon", HAS_ARG
, QEMU_OPTION_debugcon
, \
2873 "-debugcon dev redirect the debug console to char device 'dev'\n",
2876 @item
-debugcon @
var{dev
}
2878 Redirect the debug console to host device @
var{dev
} (same devices as the
2879 serial port
). The debug console is an I
/O port which is typically port
2880 0xe9; writing to that I
/O port sends output to
this device
.
2881 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2885 DEF("pidfile", HAS_ARG
, QEMU_OPTION_pidfile
, \
2886 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL
)
2888 @item
-pidfile @
var{file
}
2890 Store the QEMU process PID
in @
var{file
}. It is useful
if you launch QEMU
2894 DEF("singlestep", 0, QEMU_OPTION_singlestep
, \
2895 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL
)
2899 Run the emulation
in single step mode
.
2902 DEF("S", 0, QEMU_OPTION_S
, \
2903 "-S freeze CPU at startup (use 'c' to start execution)\n",
2908 Do not start CPU at
startup (you must type
'c' in the monitor
).
2911 DEF("realtime", HAS_ARG
, QEMU_OPTION_realtime
,
2912 "-realtime [mlock=on|off]\n"
2913 " run qemu with realtime features\n"
2914 " mlock=on|off controls mlock support (default: on)\n",
2917 @item
-realtime mlock
=on|off
2919 Run qemu with realtime features
.
2920 mlocking qemu and guest memory can be enabled via @option
{mlock
=on
}
2921 (enabled by
default).
2924 DEF("gdb", HAS_ARG
, QEMU_OPTION_gdb
, \
2925 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL
)
2927 @item
-gdb @
var{dev
}
2929 Wait
for gdb connection on device @
var{dev
} (@pxref
{gdb_usage
}). Typical
2930 connections will likely be TCP
-based
, but also UDP
, pseudo TTY
, or even
2931 stdio are reasonable use
case. The latter is allowing to start QEMU from
2932 within gdb and establish the connection via a pipe
:
2934 (gdb
) target remote | exec qemu
-system
-i386
-gdb stdio
...
2938 DEF("s", 0, QEMU_OPTION_s
, \
2939 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT
"\n",
2944 Shorthand
for -gdb tcp
::1234, i
.e
. open a gdbserver on TCP port
1234
2945 (@pxref
{gdb_usage
}).
2948 DEF("d", HAS_ARG
, QEMU_OPTION_d
, \
2949 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
2952 @item
-d @
var{item1
}[,...]
2954 Enable logging of specified items
. Use
'-d help' for a list of log items
.
2957 DEF("D", HAS_ARG
, QEMU_OPTION_D
, \
2958 "-D logfile output log to logfile (default stderr)\n",
2961 @item
-D @
var{logfile
}
2963 Output log
in @
var{logfile
} instead of to stderr
2966 DEF("L", HAS_ARG
, QEMU_OPTION_L
, \
2967 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2972 Set the directory
for the BIOS
, VGA BIOS and keymaps
.
2975 DEF("bios", HAS_ARG
, QEMU_OPTION_bios
, \
2976 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL
)
2978 @item
-bios @
var{file
}
2980 Set the filename
for the BIOS
.
2983 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm
, \
2984 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL
)
2988 Enable KVM full virtualization support
. This option is only available
2989 if KVM support is enabled when compiling
.
2992 DEF("xen-domid", HAS_ARG
, QEMU_OPTION_xen_domid
,
2993 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL
)
2994 DEF("xen-create", 0, QEMU_OPTION_xen_create
,
2995 "-xen-create create domain using xen hypercalls, bypassing xend\n"
2996 " warning: should not be used when xend is in use\n",
2998 DEF("xen-attach", 0, QEMU_OPTION_xen_attach
,
2999 "-xen-attach attach to existing xen domain\n"
3000 " xend will use this when starting QEMU\n",
3003 @item
-xen
-domid @
var{id
}
3005 Specify xen guest domain @
var{id
} (XEN only
).
3008 Create domain
using xen hypercalls
, bypassing xend
.
3009 Warning
: should not be used when xend is
in use (XEN only
).
3012 Attach to existing xen domain
.
3013 xend will use
this when starting
QEMU (XEN only
).
3016 DEF("no-reboot", 0, QEMU_OPTION_no_reboot
, \
3017 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL
)
3021 Exit instead of rebooting
.
3024 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown
, \
3025 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL
)
3028 @findex
-no
-shutdown
3029 Don
't exit QEMU on guest shutdown, but instead only stop the emulation.
3030 This allows for instance switching to monitor to commit changes to the
3034 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3035 "-loadvm [tag|id]\n" \
3036 " start right away with a saved state (loadvm in monitor)\n",
3039 @item -loadvm @var{file}
3041 Start right away with a saved state (@code{loadvm} in monitor)
3045 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3046 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3051 Daemonize the QEMU process after initialization. QEMU will not detach from
3052 standard IO until it is ready to receive connections on any of its devices.
3053 This option is a useful way for external programs to launch QEMU without having
3054 to cope with initialization race conditions.
3057 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3058 "-option-rom rom load a file, rom, into the option ROM space\n",
3061 @item -option-rom @var{file}
3063 Load the contents of @var{file} as an option ROM.
3064 This option is useful to load things like EtherBoot.
3067 HXCOMM Silently ignored for compatibility
3068 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3070 HXCOMM Options deprecated by -rtc
3071 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3072 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3074 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3075 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3076 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3081 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3083 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3084 UTC or local time, respectively. @code{localtime} is required for correct date in
3085 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3086 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3088 By default the RTC is driven by the host system time. This allows using of the
3089 RTC as accurate reference clock inside the guest, specifically if the host
3090 time is smoothly following an accurate external reference clock, e.g. via NTP.
3091 If you want to isolate the guest time from the host, you can set @option{clock}
3092 to @code{rt} instead. To even prevent it from progressing during suspension,
3093 you can set it to @code{vm}.
3095 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3096 specifically with Windows' ACPI HAL
. This option will
try to figure out how
3097 many timer interrupts were not processed by the Windows guest and will
3101 DEF("icount", HAS_ARG
, QEMU_OPTION_icount
, \
3102 "-icount [shift=N|auto][,align=on|off]\n" \
3103 " enable virtual instruction counter with 2^N clock ticks per\n" \
3104 " instruction and enable aligning the host and virtual clocks\n", QEMU_ARCH_ALL
)
3106 @item
-icount
[shift
=@
var{N
}|auto
]
3108 Enable virtual instruction counter
. The virtual cpu will execute one
3109 instruction every
2^@
var{N
} ns of virtual time
. If @code
{auto
} is specified
3110 then the virtual cpu speed will be automatically adjusted to keep virtual
3111 time within a few seconds of real time
.
3113 Note that
while this option can give deterministic behavior
, it does not
3114 provide cycle accurate emulation
. Modern CPUs contain superscalar out of
3115 order cores with complex cache hierarchies
. The number of instructions
3116 executed often has little or no correlation with actual performance
.
3118 @option
{align
=on
} will activate the delay algorithm which will
try to
3119 to synchronise the host clock and the virtual clock
. The goal is to
3120 have a guest running at the real frequency imposed by the shift option
.
3121 Whenever the guest clock is behind the host clock and
if
3122 @option
{align
=on
} is specified then we print a message to the user
3123 to inform about the delay
.
3124 Currently
this option does not work when @option
{shift
} is @code
{auto
}.
3125 Note
: The sync algorithm will work
for those shift values
for which
3126 the guest clock runs ahead of the host clock
. Typically
this happens
3127 when the shift value is
high (how high depends on the host machine
).
3130 DEF("watchdog", HAS_ARG
, QEMU_OPTION_watchdog
, \
3131 "-watchdog i6300esb|ib700\n" \
3132 " enable virtual hardware watchdog [default=none]\n",
3135 @item
-watchdog @
var{model
}
3137 Create a virtual hardware watchdog device
. Once
enabled (by a guest
3138 action
), the watchdog must be periodically polled by an agent inside
3139 the guest or
else the guest will be restarted
.
3141 The @
var{model
} is the model of hardware watchdog to emulate
. Choices
3142 for model are
: @code
{ib700
} (iBASE
700) which is a very simple ISA
3143 watchdog with a single timer
, or @code
{i6300esb
} (Intel
6300ESB I
/O
3144 controller hub
) which is a much more featureful PCI
-based dual
-timer
3145 watchdog
. Choose a model
for which your guest has drivers
.
3147 Use @code
{-watchdog help
} to list available hardware models
. Only one
3148 watchdog can be enabled
for a guest
.
3151 DEF("watchdog-action", HAS_ARG
, QEMU_OPTION_watchdog_action
, \
3152 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3153 " action when watchdog fires [default=reset]\n",
3156 @item
-watchdog
-action @
var{action
}
3157 @findex
-watchdog
-action
3159 The @
var{action
} controls what QEMU will
do when the watchdog timer
3162 @code
{reset
} (forcefully reset the guest
).
3163 Other possible actions are
:
3164 @code
{shutdown
} (attempt to gracefully shutdown the guest
),
3165 @code
{poweroff
} (forcefully poweroff the guest
),
3166 @code
{pause
} (pause the guest
),
3167 @code
{debug
} (print a debug message and
continue), or
3168 @code
{none
} (do nothing
).
3170 Note that the @code
{shutdown
} action requires that the guest responds
3171 to ACPI signals
, which it may not be able to
do in the sort of
3172 situations where the watchdog would have expired
, and thus
3173 @code
{-watchdog
-action shutdown
} is not recommended
for production use
.
3178 @item
-watchdog i6300esb
-watchdog
-action pause
3179 @item
-watchdog ib700
3183 DEF("echr", HAS_ARG
, QEMU_OPTION_echr
, \
3184 "-echr chr set terminal escape character instead of ctrl-a\n",
3188 @item
-echr @
var{numeric_ascii_value
}
3190 Change the escape character used
for switching to the monitor when
using
3191 monitor and serial sharing
. The
default is @code
{0x01} when
using the
3192 @code
{-nographic
} option
. @code
{0x01} is equal to pressing
3193 @code
{Control
-a
}. You can select a different character from the ascii
3194 control keys where
1 through
26 map to Control
-a through Control
-z
. For
3195 instance you could use the either of the following to change the escape
3196 character to Control
-t
.
3203 DEF("virtioconsole", HAS_ARG
, QEMU_OPTION_virtiocon
, \
3204 "-virtioconsole c\n" \
3205 " set virtio console\n", QEMU_ARCH_ALL
)
3207 @item
-virtioconsole @
var{c
}
3208 @findex
-virtioconsole
3211 This option is maintained
for backward compatibility
.
3213 Please use @code
{-device virtconsole
} for the
new way of invocation
.
3216 DEF("show-cursor", 0, QEMU_OPTION_show_cursor
, \
3217 "-show-cursor show cursor\n", QEMU_ARCH_ALL
)
3220 @findex
-show
-cursor
3224 DEF("tb-size", HAS_ARG
, QEMU_OPTION_tb_size
, \
3225 "-tb-size n set TB size\n", QEMU_ARCH_ALL
)
3227 @item
-tb
-size @
var{n
}
3232 DEF("incoming", HAS_ARG
, QEMU_OPTION_incoming
, \
3233 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3234 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3235 "-incoming unix:socketpath\n" \
3236 " prepare for incoming migration, listen on\n" \
3237 " specified protocol and socket address\n" \
3238 "-incoming fd:fd\n" \
3239 "-incoming exec:cmdline\n" \
3240 " accept incoming migration on given file descriptor\n" \
3241 " or from given external command\n" \
3242 "-incoming defer\n" \
3243 " wait for the URI to be specified via migrate_incoming\n",
3246 @item
-incoming tcp
:[@
var{host
}]:@
var{port
}[,to
=@
var{maxport
}][,ipv4
][,ipv6
]
3247 @item
-incoming rdma
:@
var{host
}:@
var{port
}[,ipv4
][,ipv6
]
3249 Prepare
for incoming migration
, listen on a given tcp port
.
3251 @item
-incoming unix
:@
var{socketpath
}
3252 Prepare
for incoming migration
, listen on a given unix socket
.
3254 @item
-incoming fd
:@
var{fd
}
3255 Accept incoming migration from a given filedescriptor
.
3257 @item
-incoming exec
:@
var{cmdline
}
3258 Accept incoming migration as an output from specified external command
.
3260 @item
-incoming defer
3261 Wait
for the URI to be specified via migrate_incoming
. The monitor can
3262 be used to change
settings (such as migration parameters
) prior to issuing
3263 the migrate_incoming to allow the migration to begin
.
3266 DEF("nodefaults", 0, QEMU_OPTION_nodefaults
, \
3267 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL
)
3271 Don
't create default devices. Normally, QEMU sets the default devices like serial
3272 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3273 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3278 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3279 "-chroot dir chroot to dir just before starting the VM\n",
3283 @item -chroot @var{dir}
3285 Immediately before starting guest execution, chroot to the specified
3286 directory. Especially useful in combination with -runas.
3290 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3291 "-runas user change to user id user just before starting the VM\n",
3295 @item -runas @var{user}
3297 Immediately before starting guest execution, drop root privileges, switching
3298 to the specified user.
3301 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3302 "-prom-env variable=value\n"
3303 " set OpenBIOS nvram variables\n",
3304 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3306 @item -prom-env @var{variable}=@var{value}
3308 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3310 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3311 "-semihosting semihosting mode\n",
3312 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32)
3315 @findex -semihosting
3316 Enable semihosting mode (ARM, M68K, Xtensa only).
3318 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3319 "-semihosting-config [enable=on|off,]target=native|gdb|auto semihosting configuration\n",
3320 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32)
3322 @item -semihosting-config [enable=on|off,]target=native|gdb|auto
3323 @findex -semihosting-config
3324 Enable semihosting and define where the semihosting calls will be addressed,
3325 to QEMU (@code{native}) or to GDB (@code{gdb}). The default is @code{auto}, which means
3326 @code{gdb} during debug sessions and @code{native} otherwise (ARM, M68K, Xtensa only).
3328 DEF("old-param", 0, QEMU_OPTION_old_param,
3329 "-old-param old param mode\n", QEMU_ARCH_ARM)
3332 @findex -old-param (ARM)
3333 Old param mode (ARM only).
3336 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3337 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off
').\n",
3340 @item -sandbox @var{arg}
3342 Enable Seccomp mode 2 system call filter. 'on
' will enable syscall filtering and 'off
' will
3343 disable it. The default is 'off
'.
3346 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3347 "-readconfig <file>\n", QEMU_ARCH_ALL)
3349 @item -readconfig @var{file}
3351 Read device configuration from @var{file}. This approach is useful when you want to spawn
3352 QEMU process with many command line options but you don't want to exceed the command line
3355 DEF("writeconfig", HAS_ARG
, QEMU_OPTION_writeconfig
,
3356 "-writeconfig <file>\n"
3357 " read/write config file\n", QEMU_ARCH_ALL
)
3359 @item
-writeconfig @
var{file
}
3360 @findex
-writeconfig
3361 Write device configuration to @
var{file
}. The @
var{file
} can be either filename to save
3362 command line and device configuration into file or dash @code
{-}) character to print the
3363 output to stdout
. This can be later used as input file
for @code
{-readconfig
} option
.
3365 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig
,
3367 " do not load default config files at startup\n",
3371 @findex
-nodefconfig
3372 Normally QEMU loads configuration files from @
var{sysconfdir
} and @
var{datadir
} at startup
.
3373 The @code
{-nodefconfig
} option will prevent QEMU from loading any of those config files
.
3375 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig
,
3377 " do not load user-provided config files at startup\n",
3380 @item
-no
-user
-config
3381 @findex
-no
-user
-config
3382 The @code
{-no
-user
-config
} option makes QEMU not load any of the user
-provided
3383 config files on @
var{sysconfdir
}, but won
't make it skip the QEMU-provided config
3384 files from @var{datadir}.
3386 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3387 "-trace [events=<file>][,file=<file>]\n"
3388 " specify tracing options\n",
3391 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3392 HXCOMM HX does not support conditional compilation of text.
3393 @item -trace [events=@var{file}][,file=@var{file}]
3396 Specify tracing options.
3399 @item events=@var{file}
3400 Immediately enable events listed in @var{file}.
3401 The file must contain one event name (as listed in the @var{trace-events} file)
3403 This option is only available if QEMU has been compiled with
3404 either @var{simple} or @var{stderr} tracing backend.
3405 @item file=@var{file}
3406 Log output traces to @var{file}.
3408 This option is only available if QEMU has been compiled with
3409 the @var{simple} tracing backend.
3414 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3415 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3418 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3419 "-enable-fips enable FIPS 140-2 compliance\n",
3424 @findex -enable-fips
3425 Enable FIPS 140-2 compliance mode.
3428 HXCOMM Deprecated by -machine accel=tcg property
3429 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3431 HXCOMM Deprecated by kvm-pit driver properties
3432 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3435 HXCOMM Deprecated (ignored)
3436 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
3438 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3439 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3441 HXCOMM Deprecated (ignored)
3442 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3444 DEF("object", HAS_ARG, QEMU_OPTION_object,
3445 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3446 " create an new object of type TYPENAME setting properties\n"
3447 " in the order they are specified. Note that the 'id
'\n"
3448 " property must be set. These objects are placed in the\n"
3449 " '/objects
' path.\n",
3452 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3454 Create an new object of type @var{typename} setting properties
3455 in the order they are specified. Note that the 'id
'
3456 property must be set. These objects are placed in the
3460 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3461 "-msg timestamp[=on|off]\n"
3462 " change the format of messages\n"
3463 " on|off controls leading timestamps (default:on)\n",
3466 @item -msg timestamp[=on|off]
3468 prepend a timestamp to each log message.(default:on)
3471 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3472 "-dump-vmstate <file>\n"
3473 " Output vmstate information in JSON format to file.\n"
3474 " Use the scripts/vmstate-static-checker.py file to\n"
3475 " check for possible regressions in migration code\n"
3476 " by comparing two such vmstate dumps.",
3479 @item -dump-vmstate @var{file}
3480 @findex -dump-vmstate
3481 Dump json-encoded vmstate information for current machine type to file
3485 HXCOMM This is the last statement. Insert new options before this line!