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.property=value\n"
175 "-global driver=driver,property=property,value=value\n"
176 " set a global default for a driver property\n",
179 @item -global @var{driver}.@var{prop}=@var{value}
180 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
182 Set default value of @var{driver}'s property @
var{prop
} to @
var{value
}, e
.g
.:
185 qemu
-system
-i386
-global ide
-drive
.physical_block_size
=4096 -drive file
=file
,if=ide
,index
=0,media
=disk
188 In particular
, you can use
this to set driver properties
for devices which are
189 created automatically by the machine model
. To create a device which is not
190 created automatically and set properties on it
, use
-@option
{device
}.
192 The two syntaxes are equivalent
. The longer one works
for drivers whose name
196 DEF("boot", HAS_ARG
, QEMU_OPTION_boot
,
197 "-boot [order=drives][,once=drives][,menu=on|off]\n"
198 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
199 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
200 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
201 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
202 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
205 @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
]
207 Specify boot order @
var{drives
} as a string of drive letters
. Valid
208 drive letters depend on the target achitecture
. The x86 PC uses
: a
, b
209 (floppy
1 and
2), c (first hard disk
), d (first CD
-ROM
), n
-p (Etherboot
210 from network adapter
1-4), hard disk boot is the
default. To apply a
211 particular boot order only on the first startup
, specify it via
214 Interactive boot menus
/prompts can be enabled via @option
{menu
=on
} as far
215 as firmware
/BIOS supports them
. The
default is non
-interactive boot
.
217 A splash picture could be passed to bios
, enabling user to show it as logo
,
218 when option splash
=@
var{sp_name
} is given and menu
=on
, If firmware
/BIOS
219 supports them
. Currently Seabios
for X86 system support it
.
220 limitation
: The splash file could be a jpeg file or a BMP file
in 24 BPP
221 format(true color
). The resolution should be supported by the SVGA mode
, so
222 the recommended is
320x240
, 640x480
, 800x640
.
224 A timeout could be passed to bios
, guest will pause
for @
var{rb_timeout
} ms
225 when boot failed
, then reboot
. If @
var{rb_timeout
} is
'-1', guest will not
226 reboot
, qemu passes
'-1' to bios by
default. Currently Seabios
for X86
229 Do strict boot via @option
{strict
=on
} as far as firmware
/BIOS
230 supports it
. This only effects when boot priority is changed by
231 bootindex options
. The
default is non
-strict boot
.
234 #
try to boot from network first
, then from hard disk
235 qemu
-system
-i386
-boot order
=nc
236 # boot from CD
-ROM first
, switch back to
default order after reboot
237 qemu
-system
-i386
-boot once
=d
238 # boot with a splash picture
for 5 seconds
.
239 qemu
-system
-i386
-boot menu
=on
,splash
=/root
/boot
.bmp
,splash
-time
=5000
242 Note
: The legacy format
'-boot @var{drives}' is still supported but its
243 use is discouraged as it may be removed from future versions
.
246 DEF("m", HAS_ARG
, QEMU_OPTION_m
,
247 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
248 " configure guest RAM\n"
249 " size: initial amount of guest memory\n"
250 " slots: number of hotplug slots (default: none)\n"
251 " maxmem: maximum amount of guest memory (default: none)\n"
252 "NOTE: Some architectures might enforce a specific granularity\n",
255 @item
-m
[size
=]@
var{megs
}[,slots
=n
,maxmem
=size
]
257 Sets guest startup RAM size to @
var{megs
} megabytes
. Default is
128 MiB
.
258 Optionally
, a suffix of ``M
'' or ``G
'' can be used to signify a value
in
259 megabytes or gigabytes respectively
. Optional pair @
var{slots
}, @
var{maxmem
}
260 could be used to set amount of hotpluggable memory slots and maximum amount of
261 memory
. Note that @
var{maxmem
} must be aligned to the page size
.
263 For example
, the following command
-line sets the guest startup RAM size to
264 1GB
, creates
3 slots to hotplug additional memory and sets the maximum
265 memory the guest can reach to
4GB
:
268 qemu
-system
-x86_64
-m
1G
,slots
=3,maxmem
=4G
271 If @
var{slots
} and @
var{maxmem
} are not specified
, memory hotplug won
't
272 be enabled and the guest startup RAM will never increase.
275 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
276 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
278 @item -mem-path @var{path}
280 Allocate guest RAM from a temporarily created file in @var{path}.
283 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
284 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
288 @findex -mem-prealloc
289 Preallocate memory when using -mem-path.
292 DEF("k", HAS_ARG, QEMU_OPTION_k,
293 "-k language use keyboard layout (for example 'fr
' for French)\n",
296 @item -k @var{language}
298 Use keyboard layout @var{language} (for example @code{fr} for
299 French). This option is only needed where it is not easy to get raw PC
300 keycodes (e.g. on Macs, with some X11 servers or with a VNC
301 display). You don't normally need to use it on PC
/Linux or PC
/Windows
304 The available layouts are
:
306 ar de
-ch es fo fr
-ca hu ja mk no pt
-br sv
307 da en
-gb et fr fr
-ch is lt nl pl ru th
308 de en
-us fi fr
-be hr it lv nl
-be pt sl tr
311 The
default is @code
{en
-us
}.
315 DEF("audio-help", 0, QEMU_OPTION_audio_help
,
316 "-audio-help print list of audio drivers and their options\n",
321 Will show the audio subsystem help
: list of drivers
, tunable
325 DEF("soundhw", HAS_ARG
, QEMU_OPTION_soundhw
,
326 "-soundhw c1,... enable audio support\n"
327 " and only specified sound cards (comma separated list)\n"
328 " use '-soundhw help' to get the list of supported cards\n"
329 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL
)
331 @item
-soundhw @
var{card1
}[,@
var{card2
},...] or
-soundhw all
333 Enable audio and selected sound hardware
. Use
'help' to print all
334 available sound hardware
.
337 qemu
-system
-i386
-soundhw sb16
,adlib disk
.img
338 qemu
-system
-i386
-soundhw es1370 disk
.img
339 qemu
-system
-i386
-soundhw ac97 disk
.img
340 qemu
-system
-i386
-soundhw hda disk
.img
341 qemu
-system
-i386
-soundhw all disk
.img
342 qemu
-system
-i386
-soundhw help
345 Note that Linux
's i810_audio OSS kernel (for AC97) module might
346 require manually specifying clocking.
349 modprobe i810_audio clocking=48000
353 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
354 "-balloon none disable balloon device\n"
355 "-balloon virtio[,addr=str]\n"
356 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
360 Disable balloon device.
361 @item -balloon virtio[,addr=@var{addr}]
362 Enable virtio balloon device (default), optionally with PCI address
366 DEF("device", HAS_ARG, QEMU_OPTION_device,
367 "-device driver[,prop[=value][,...]]\n"
368 " add device (based on driver)\n"
369 " prop=value,... sets driver properties\n"
370 " use '-device help
' to print all possible drivers\n"
371 " use '-device driver
,help
' to print all possible properties\n",
374 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
376 Add device @var{driver}. @var{prop}=@var{value} sets driver
377 properties. Valid properties depend on the driver. To get help on
378 possible drivers and properties, use @code{-device help} and
379 @code{-device @var{driver},help}.
382 DEF("name", HAS_ARG, QEMU_OPTION_name,
383 "-name string1[,process=string2][,debug-threads=on|off]\n"
384 " set the name of the guest\n"
385 " string1 sets the window title and string2 the process name (on Linux)\n"
386 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
387 " NOTE: The thread names are for debugging and not a stable API.\n",
390 @item -name @var{name}
392 Sets the @var{name} of the guest.
393 This name will be displayed in the SDL window caption.
394 The @var{name} will also be used for the VNC server.
395 Also optionally set the top visible process name in Linux.
396 Naming of individual threads can also be enabled on Linux to aid debugging.
399 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
400 "-uuid %08x-%04x-%04x-%04x-%012x\n"
401 " specify machine UUID\n", QEMU_ARCH_ALL)
403 @item -uuid @var{uuid}
413 DEFHEADING(Block device options:)
418 DEF("fda", HAS_ARG, QEMU_OPTION_fda,
419 "-fda/-fdb file use 'file
' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
420 DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
422 @item -fda @var{file}
423 @item -fdb @var{file}
426 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
429 DEF("hda", HAS_ARG, QEMU_OPTION_hda,
430 "-hda/-hdb file use 'file
' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
431 DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
432 DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
433 "-hdc/-hdd file use 'file
' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
434 DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
436 @item -hda @var{file}
437 @item -hdb @var{file}
438 @item -hdc @var{file}
439 @item -hdd @var{file}
444 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
447 DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
448 "-cdrom file use 'file
' as IDE cdrom image (cdrom is ide1 master)\n",
451 @item -cdrom @var{file}
453 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
454 @option{-cdrom} at the same time). You can use the host CD-ROM by
455 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
458 DEF("drive", HAS_ARG, QEMU_OPTION_drive,
459 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
460 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
461 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
462 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
463 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
464 " [,readonly=on|off][,copy-on-read=on|off]\n"
465 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
466 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
467 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
468 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
469 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
470 " [[,iops_size=is]]\n"
472 " use 'file
' as a drive image\n", QEMU_ARCH_ALL)
474 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
477 Define a new drive. Valid options are:
480 @item file=@var{file}
481 This option defines which disk image (@pxref{disk_images}) to use with
482 this drive. If the filename contains comma, you must double it
483 (for instance, "file=my,,file" to use file "my,file").
485 Special files such as iSCSI devices can be specified using protocol
486 specific URLs. See the section for "Device URL Syntax" for more information.
487 @item if=@var{interface}
488 This option defines on which type on interface the drive is connected.
489 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio.
490 @item bus=@var{bus},unit=@var{unit}
491 These options define where is connected the drive by defining the bus number and
493 @item index=@var{index}
494 This option defines where is connected the drive by using an index in the list
495 of available connectors of a given interface type.
496 @item media=@var{media}
497 This option defines the type of the media: disk or cdrom.
498 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
499 These options have the same definition as they have in @option{-hdachs}.
500 @item snapshot=@var{snapshot}
501 @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
502 (see @option{-snapshot}).
503 @item cache=@var{cache}
504 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
506 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
507 @item discard=@var{discard}
508 @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.
509 @item format=@var{format}
510 Specify which disk @var{format} will be used rather than detecting
511 the format. Can be used to specifiy format=raw to avoid interpreting
512 an untrusted format header.
513 @item serial=@var{serial}
514 This option specifies the serial number to assign to the device.
515 @item addr=@var{addr}
516 Specify the controller's PCI
address (if=virtio only
).
517 @item werror
=@
var{action
},rerror
=@
var{action
}
518 Specify which @
var{action
} to take on write and read errors
. Valid actions are
:
519 "ignore" (ignore the error and
try to
continue), "stop" (pause QEMU
),
520 "report" (report the error to the guest
), "enospc" (pause QEMU only
if the
521 host disk is full
; report the error to the guest otherwise
).
522 The
default setting is @option
{werror
=enospc
} and @option
{rerror
=report
}.
524 Open drive @option
{file
} as read
-only
. Guest write attempts will fail
.
525 @item copy
-on
-read
=@
var{copy
-on
-read
}
526 @
var{copy
-on
-read
} is
"on" or
"off" and enables whether to copy read backing
527 file sectors into the image file
.
528 @item detect
-zeroes
=@
var{detect
-zeroes
}
529 @
var{detect
-zeroes
} is
"off", "on" or
"unmap" and enables the automatic
530 conversion of plain zero writes by the OS to driver specific optimized
531 zero write commands
. You may even choose
"unmap" if @
var{discard
} is set
532 to
"unmap" to allow a zero write to be converted to an UNMAP operation
.
535 By
default, the @option
{cache
=writeback
} mode is used
. It will report data
536 writes as completed as soon as the data is present
in the host page cache
.
537 This is safe as long as your guest OS makes sure to correctly flush disk caches
538 where needed
. If your guest OS does not handle volatile disk write caches
539 correctly and your host crashes or loses power
, then the guest may experience
542 For such guests
, you should consider
using @option
{cache
=writethrough
}. This
543 means that the host page cache will be used to read and write data
, but write
544 notification will be sent to the guest only after QEMU has made sure to flush
545 each write to the disk
. Be aware that
this has a major impact on performance
.
547 The host page cache can be avoided entirely with @option
{cache
=none
}. This will
548 attempt to
do disk IO directly to the guest
's memory. QEMU may still perform
549 an internal copy of the data. Note that this is considered a writeback mode and
550 the guest OS must handle the disk write cache correctly in order to avoid data
551 corruption on host crashes.
553 The host page cache can be avoided while only sending write notifications to
554 the guest when the data has been flushed to the disk using
555 @option{cache=directsync}.
557 In case you don't care about data integrity over host failures
, use
558 @option
{cache
=unsafe
}. This option tells QEMU that it
never needs to write any
559 data to the disk but can instead keep things
in cache
. If anything goes wrong
,
560 like your host losing power
, the disk storage getting disconnected accidentally
,
561 etc
. your image will most probably be rendered unusable
. When
using
562 the @option
{-snapshot
} option
, unsafe caching is always used
.
564 Copy
-on
-read avoids accessing the same backing file sectors repeatedly and is
565 useful when the backing file is over a slow network
. By
default copy
-on
-read
568 Instead of @option
{-cdrom
} you can use
:
570 qemu
-system
-i386
-drive file
=file
,index
=2,media
=cdrom
573 Instead of @option
{-hda
}, @option
{-hdb
}, @option
{-hdc
}, @option
{-hdd
}, you can
576 qemu
-system
-i386
-drive file
=file
,index
=0,media
=disk
577 qemu
-system
-i386
-drive file
=file
,index
=1,media
=disk
578 qemu
-system
-i386
-drive file
=file
,index
=2,media
=disk
579 qemu
-system
-i386
-drive file
=file
,index
=3,media
=disk
582 You can open an image
using pre
-opened file descriptors from an fd set
:
585 -add
-fd fd
=3,set
=2,opaque
="rdwr:/path/to/file"
586 -add
-fd fd
=4,set
=2,opaque
="rdonly:/path/to/file"
587 -drive file
=/dev
/fdset
/2,index
=0,media
=disk
590 You can connect a CDROM to the slave of ide0
:
592 qemu
-system
-i386
-drive file
=file
,if=ide
,index
=1,media
=cdrom
595 If you don
't specify the "file=" argument, you define an empty drive:
597 qemu-system-i386 -drive if=ide,index=1,media=cdrom
600 You can connect a SCSI disk with unit ID 6 on the bus #0:
602 qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6
605 Instead of @option{-fda}, @option{-fdb}, you can use:
607 qemu-system-i386 -drive file=file,index=0,if=floppy
608 qemu-system-i386 -drive file=file,index=1,if=floppy
611 By default, @var{interface} is "ide" and @var{index} is automatically
614 qemu-system-i386 -drive file=a -drive file=b"
618 qemu-system-i386 -hda a -hdb b
622 DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
623 "-mtdblock file use 'file
' as on-board Flash memory image\n",
626 @item -mtdblock @var{file}
628 Use @var{file} as on-board Flash memory image.
631 DEF("sd", HAS_ARG, QEMU_OPTION_sd,
632 "-sd file use 'file
' as SecureDigital card image\n", QEMU_ARCH_ALL)
636 Use @var{file} as SecureDigital card image.
639 DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
640 "-pflash file use 'file
' as a parallel flash image\n", QEMU_ARCH_ALL)
642 @item -pflash @var{file}
644 Use @var{file} as a parallel flash image.
647 DEF("snapshot", 0, QEMU_OPTION_snapshot,
648 "-snapshot write to temporary files instead of disk image files\n",
653 Write to temporary files instead of disk image files. In this case,
654 the raw disk image you use is not written back. You can however force
655 the write back by pressing @key{C-a s} (@pxref{disk_images}).
658 DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
659 "-hdachs c,h,s[,t]\n" \
660 " force hard disk 0 physical geometry and the optional BIOS\n" \
661 " translation (t=none or lba) (usually QEMU can guess them)\n",
664 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
666 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
667 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
668 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
669 all those parameters. This option is useful for old MS-DOS disk
673 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
674 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
675 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
680 @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}]
682 Define a new file system device. Valid options are:
685 This option specifies the fs driver backend to use.
686 Currently "local", "handle" and "proxy" file system drivers are supported.
688 Specifies identifier for this device
689 @item path=@var{path}
690 Specifies the export path for the file system device. Files under
691 this path will be available to the 9p client on the guest.
692 @item security_model=@var{security_model}
693 Specifies the security model to be used for this export path.
694 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
695 In "passthrough" security model, files are stored using the same
696 credentials as they are created on the guest. This requires QEMU
697 to run as root. In "mapped-xattr" security model, some of the file
698 attributes like uid, gid, mode bits and link target are stored as
699 file attributes. For "mapped-file" these attributes are stored in the
700 hidden .virtfs_metadata directory. Directories exported by this security model cannot
701 interact with other unix tools. "none" security model is same as
702 passthrough except the sever won't report failures
if it fails to
703 set file attributes like ownership
. Security model is mandatory
704 only
for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take
705 security model as a parameter.
706 @item writeout=@var{writeout}
707 This is an optional argument. The only supported value is "immediate".
708 This means that host page cache will be used to read and write data but
709 write notification will be sent to the guest only when the data has been
710 reported as written by the storage subsystem.
712 Enables exporting 9p share as a readonly mount for guests. By default
713 read-write access is given.
714 @item socket=@var{socket}
715 Enables proxy filesystem driver to use passed socket file for communicating
716 with virtfs-proxy-helper
717 @item sock_fd=@var{sock_fd}
718 Enables proxy filesystem driver to use passed socket descriptor for
719 communicating with virtfs-proxy-helper. Usually a helper like libvirt
720 will create socketpair and pass one of the fds as sock_fd
723 -fsdev option is used along with -device driver "virtio-9p-pci".
724 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
725 Options for virtio-9p-pci driver are:
728 Specifies the id value specified along with -fsdev option
729 @item mount_tag=@var{mount_tag}
730 Specifies the tag name to be used by the guest to mount this export point
735 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
736 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
737 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
742 @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}]
745 The general form of a Virtual File system pass-through options are:
748 This option specifies the fs driver backend to use.
749 Currently "local", "handle" and "proxy" file system drivers are supported.
751 Specifies identifier for this device
752 @item path=@var{path}
753 Specifies the export path for the file system device. Files under
754 this path will be available to the 9p client on the guest.
755 @item security_model=@var{security_model}
756 Specifies the security model to be used for this export path.
757 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
758 In "passthrough" security model, files are stored using the same
759 credentials as they are created on the guest. This requires QEMU
760 to run as root. In "mapped-xattr" security model, some of the file
761 attributes like uid, gid, mode bits and link target are stored as
762 file attributes. For "mapped-file" these attributes are stored in the
763 hidden .virtfs_metadata directory. Directories exported by this security model cannot
764 interact with other unix tools. "none" security model is same as
765 passthrough except the sever won't report failures
if it fails to
766 set file attributes like ownership
. Security model is mandatory only
767 for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take security
768 model as a parameter.
769 @item writeout=@var{writeout}
770 This is an optional argument. The only supported value is "immediate".
771 This means that host page cache will be used to read and write data but
772 write notification will be sent to the guest only when the data has been
773 reported as written by the storage subsystem.
775 Enables exporting 9p share as a readonly mount for guests. By default
776 read-write access is given.
777 @item socket=@var{socket}
778 Enables proxy filesystem driver to use passed socket file for
779 communicating with virtfs-proxy-helper. Usually a helper like libvirt
780 will create socketpair and pass one of the fds as sock_fd
782 Enables proxy filesystem driver to use passed 'sock_fd
' as the socket
783 descriptor for interfacing with virtfs-proxy-helper
787 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
788 "-virtfs_synth Create synthetic file system image\n",
792 @findex -virtfs_synth
793 Create synthetic file system image
801 DEFHEADING(USB options:)
806 DEF("usb", 0, QEMU_OPTION_usb,
807 "-usb enable the USB driver (will be the default soon)\n",
812 Enable the USB driver (will be the default soon)
815 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
816 "-usbdevice name add the host or guest USB device 'name
'\n",
820 @item -usbdevice @var{devname}
822 Add the USB device @var{devname}. @xref{usb_devices}.
827 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
830 Pointer device that uses absolute coordinates (like a touchscreen). This
831 means QEMU is able to report the mouse position without having to grab the
832 mouse. Also overrides the PS/2 mouse emulation when activated.
834 @item disk:[format=@var{format}]:@var{file}
835 Mass storage device based on file. The optional @var{format} argument
836 will be used rather than detecting the format. Can be used to specifiy
837 @code{format=raw} to avoid interpreting an untrusted format header.
839 @item host:@var{bus}.@var{addr}
840 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
842 @item host:@var{vendor_id}:@var{product_id}
843 Pass through the host device identified by @var{vendor_id}:@var{product_id}
846 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
847 Serial converter to host character device @var{dev}, see @code{-serial} for the
851 Braille device. This will use BrlAPI to display the braille output on a real
854 @item net:@var{options}
855 Network adapter that supports CDC ethernet and RNDIS protocols.
865 DEFHEADING(Display options:)
870 DEF("display", HAS_ARG, QEMU_OPTION_display,
871 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
872 " [,window_close=on|off]|curses|none|\n"
873 " gtk[,grab_on_hover=on|off]|\n"
874 " vnc=<display>[,<optargs>]\n"
875 " select display type\n", QEMU_ARCH_ALL)
877 @item -display @var{type}
879 Select type of display to use. This option is a replacement for the
880 old style -sdl/-curses/... options. Valid values for @var{type} are
883 Display video output via SDL (usually in a separate graphics
884 window; see the SDL documentation for other possibilities).
886 Display video output via curses. For graphics device models which
887 support a text mode, QEMU can display this output using a
888 curses/ncurses interface. Nothing is displayed when the graphics
889 device is in graphical mode or if the graphics device does not support
890 a text mode. Generally only the VGA device models support text mode.
892 Do not display video output. The guest will still see an emulated
893 graphics card, but its output will not be displayed to the QEMU
894 user. This option differs from the -nographic option in that it
895 only affects what is done with video output; -nographic also changes
896 the destination of the serial and parallel port data.
898 Display video output in a GTK window. This interface provides drop-down
899 menus and other UI elements to configure and control the VM during
902 Start a VNC server on display <arg>
906 DEF("nographic", 0, QEMU_OPTION_nographic,
907 "-nographic disable graphical output and redirect serial I/Os to console\n",
912 Normally, QEMU uses SDL to display the VGA output. With this option,
913 you can totally disable graphical output so that QEMU is a simple
914 command line application. The emulated serial port is redirected on
915 the console and muxed with the monitor (unless redirected elsewhere
916 explicitly). Therefore, you can still use QEMU to debug a Linux kernel
917 with a serial console. Use @key{C-a h} for help on switching between
918 the console and monitor.
921 DEF("curses", 0, QEMU_OPTION_curses,
922 "-curses use a curses/ncurses interface instead of SDL\n",
927 Normally, QEMU uses SDL to display the VGA output. With this option,
928 QEMU can display the VGA output when in text mode using a
929 curses/ncurses interface. Nothing is displayed in graphical mode.
932 DEF("no-frame", 0, QEMU_OPTION_no_frame,
933 "-no-frame open SDL window without a frame and window decorations\n",
938 Do not use decorations for SDL windows and start them using the whole
939 available screen space. This makes the using QEMU in a dedicated desktop
940 workspace more convenient.
943 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
944 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
949 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
950 affects the special keys (for fullscreen, monitor-mode switching, etc).
953 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
954 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
959 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
960 affects the special keys (for fullscreen, monitor-mode switching, etc).
963 DEF("no-quit", 0, QEMU_OPTION_no_quit,
964 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
968 Disable SDL window close capability.
971 DEF("sdl", 0, QEMU_OPTION_sdl,
972 "-sdl enable SDL\n", QEMU_ARCH_ALL)
979 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
980 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
981 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
982 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
983 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
984 " [,tls-ciphers=<list>]\n"
985 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
986 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
987 " [,sasl][,password=<secret>][,disable-ticketing]\n"
988 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
989 " [,jpeg-wan-compression=[auto|never|always]]\n"
990 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
991 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
992 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
993 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
995 " at least one of {port, tls-port} is mandatory\n",
998 @item -spice @var{option}[,@var{option}[,...]]
1000 Enable the spice remote desktop protocol. Valid options are
1005 Set the TCP port spice is listening on for plaintext channels.
1008 Set the IP address spice is listening on. Default is any address.
1013 Force using the specified IP version.
1015 @item password=<secret>
1016 Set the password you need to authenticate.
1019 Require that the client use SASL to authenticate with the spice.
1020 The exact choice of authentication method used is controlled from the
1021 system / user's SASL configuration file
for the
'qemu' service
. This
1022 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
1023 unprivileged user
, an environment variable SASL_CONF_PATH can be used
1024 to make it search alternate locations
for the service config
.
1025 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
1026 it is recommended that SASL always be combined with the
'tls' and
1027 'x509' settings to enable use of SSL and server certificates
. This
1028 ensures a data encryption preventing compromise of authentication
1031 @item disable
-ticketing
1032 Allow client connects without authentication
.
1034 @item disable
-copy
-paste
1035 Disable copy paste between the client and the guest
.
1037 @item disable
-agent
-file
-xfer
1038 Disable spice
-vdagent based file
-xfer between the client and the guest
.
1041 Set the TCP port spice is listening on
for encrypted channels
.
1043 @item x509
-dir
=<dir
>
1044 Set the x509 file directory
. Expects same filenames as
-vnc $display
,x509
=$dir
1046 @item x509
-key
-file
=<file
>
1047 @item x509
-key
-password
=<file
>
1048 @item x509
-cert
-file
=<file
>
1049 @item x509
-cacert
-file
=<file
>
1050 @item x509
-dh
-key
-file
=<file
>
1051 The x509 file names can also be configured individually
.
1053 @item tls
-ciphers
=<list
>
1054 Specify which ciphers to use
.
1056 @item tls
-channel
=[main|display|cursor|inputs|record|playback
]
1057 @item plaintext
-channel
=[main|display|cursor|inputs|record|playback
]
1058 Force specific channel to be used with or without TLS encryption
. The
1059 options can be specified multiple times to configure multiple
1060 channels
. The special name
"default" can be used to set the
default
1061 mode
. For channels which are not explicitly forced into one mode the
1062 spice client is allowed to pick tls
/plaintext as he pleases
.
1064 @item image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]
1065 Configure image
compression (lossless
).
1066 Default is auto_glz
.
1068 @item jpeg
-wan
-compression
=[auto|
never|always
]
1069 @item zlib
-glz
-wan
-compression
=[auto|
never|always
]
1070 Configure wan image
compression (lossy
for slow links
).
1073 @item streaming
-video
=[off|all|filter
]
1074 Configure video stream detection
. Default is filter
.
1076 @item agent
-mouse
=[on|off
]
1077 Enable
/disable passing mouse events via vdagent
. Default is on
.
1079 @item playback
-compression
=[on|off
]
1080 Enable
/disable audio stream
compression (using celt
0.5.1). Default is on
.
1082 @item seamless
-migration
=[on|off
]
1083 Enable
/disable spice seamless migration
. Default is off
.
1088 DEF("portrait", 0, QEMU_OPTION_portrait
,
1089 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1094 Rotate graphical output
90 deg
left (only PXA LCD
).
1097 DEF("rotate", HAS_ARG
, QEMU_OPTION_rotate
,
1098 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1101 @item
-rotate @
var{deg
}
1103 Rotate graphical output some deg
left (only PXA LCD
).
1106 DEF("vga", HAS_ARG
, QEMU_OPTION_vga
,
1107 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|none]\n"
1108 " select video card type\n", QEMU_ARCH_ALL
)
1110 @item
-vga @
var{type
}
1112 Select type of VGA card to emulate
. Valid values
for @
var{type
} are
1115 Cirrus Logic GD5446 Video card
. All Windows versions starting from
1116 Windows
95 should recognize and use
this graphic card
. For optimal
1117 performances
, use
16 bit color depth
in the guest and the host OS
.
1118 (This one is the
default)
1120 Standard VGA card with Bochs VBE extensions
. If your guest OS
1121 supports the VESA
2.0 VBE
extensions (e
.g
. Windows XP
) and
if you want
1122 to use high resolution
modes (>= 1280x1024x16
) then you should use
1125 VMWare SVGA
-II compatible adapter
. Use it
if you have sufficiently
1126 recent XFree86
/XOrg server or Windows guest with a driver
for this
1129 QXL paravirtual graphic card
. It is VGA
compatible (including VESA
1130 2.0 VBE support
). Works best with qxl guest drivers installed though
.
1131 Recommended choice when
using the spice protocol
.
1133 (sun4m only
) Sun TCX framebuffer
. This is the
default framebuffer
for
1134 sun4m machines and offers both
8-bit and
24-bit colour depths at a
1135 fixed resolution of
1024x768
.
1137 (sun4m only
) Sun cgthree framebuffer
. This is a simple
8-bit framebuffer
1138 for sun4m machines available
in both
1024x768 (OpenBIOS
) and
1152x900 (OBP
)
1139 resolutions aimed at people wishing to run older Solaris versions
.
1145 DEF("full-screen", 0, QEMU_OPTION_full_screen
,
1146 "-full-screen start in full screen\n", QEMU_ARCH_ALL
)
1149 @findex
-full
-screen
1150 Start
in full screen
.
1153 DEF("g", 1, QEMU_OPTION_g
,
1154 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1155 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
1157 @item
-g @
var{width
}x@
var{height
}[x@
var{depth
}]
1159 Set the initial graphical resolution and
depth (PPC
, SPARC only
).
1162 DEF("vnc", HAS_ARG
, QEMU_OPTION_vnc
,
1163 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL
)
1165 @item
-vnc @
var{display
}[,@
var{option
}[,@
var{option
}[,...]]]
1167 Normally
, QEMU uses SDL to display the VGA output
. With
this option
,
1168 you can have QEMU listen on VNC display @
var{display
} and redirect the VGA
1169 display over the VNC session
. It is very useful to enable the usb
1170 tablet device when
using this option (option @option
{-usbdevice
1171 tablet
}). When
using the VNC display
, you must use the @option
{-k
}
1172 parameter to set the keyboard layout
if you are not
using en
-us
. Valid
1173 syntax
for the @
var{display
} is
1177 @item @
var{host
}:@
var{d
}
1179 TCP connections will only be allowed from @
var{host
} on display @
var{d
}.
1180 By convention the TCP port is
5900+@
var{d
}. Optionally
, @
var{host
} can
1181 be omitted
in which
case the server will accept connections from any host
.
1183 @item unix
:@
var{path
}
1185 Connections will be allowed over UNIX domain sockets where @
var{path
} is the
1186 location of a unix socket to listen
for connections on
.
1190 VNC is initialized but not started
. The monitor @code
{change
} command
1191 can be used to later start the VNC server
.
1195 Following the @
var{display
} value there may be one or more @
var{option
} flags
1196 separated by commas
. Valid options are
1202 Connect to a listening VNC client via a ``reverse
'' connection
. The
1203 client is specified by the @
var{display
}. For reverse network
1204 connections (@
var{host
}:@
var{d
},@code
{reverse
}), the @
var{d
} argument
1205 is a TCP port number
, not a display number
.
1209 Opens an additional TCP listening port dedicated to VNC Websocket connections
.
1210 By definition the Websocket port is
5700+@
var{display
}. If @
var{host
} is
1211 specified connections will only be allowed from
this host
.
1212 As an alternative the Websocket port could be specified by
using
1213 @code
{websocket
}=@
var{port
}.
1214 TLS encryption
for the Websocket connection is supported
if the required
1215 certificates are specified with the VNC option @option
{x509
}.
1219 Require that password based authentication is used
for client connections
.
1221 The password must be set separately
using the @code
{set_password
} command
in
1222 the @ref
{pcsys_monitor
}. The syntax to change your password is
:
1223 @code
{set_password
<protocol
> <password
>} where
<protocol
> could be either
1226 If you would like to change
<protocol
> password expiration
, you should use
1227 @code
{expire_password
<protocol
> <expiration
-time
>} where expiration time could
1228 be one of the following options
: now
, never, +seconds or UNIX time of
1229 expiration
, e
.g
. +60 to make password expire
in 60 seconds
, or
1335196800
1230 to make password expire on
"Mon Apr 23 12:00:00 EDT 2012" (UNIX time
for this
1233 You can also use keywords
"now" or
"never" for the expiration time to
1234 allow
<protocol
> password to expire immediately or
never expire
.
1238 Require that client use TLS when communicating with the VNC server
. This
1239 uses anonymous TLS credentials so is susceptible to a man
-in-the
-middle
1240 attack
. It is recommended that
this option be combined with either the
1241 @option
{x509
} or @option
{x509verify
} options
.
1243 @item x509
=@
var{/path
/to
/certificate
/dir
}
1245 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1246 for negotiating the TLS session
. The server will send its x509 certificate
1247 to the client
. It is recommended that a password be set on the VNC server
1248 to provide authentication of the client when
this is used
. The path following
1249 this option specifies where the x509 certificates are to be loaded from
.
1250 See the @ref
{vnc_security
} section
for details on generating certificates
.
1252 @item x509verify
=@
var{/path
/to
/certificate
/dir
}
1254 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1255 for negotiating the TLS session
. The server will send its x509 certificate
1256 to the client
, and request that the client send its own x509 certificate
.
1257 The server will validate the client
's certificate against the CA certificate,
1258 and reject clients when validation fails. If the certificate authority is
1259 trusted, this is a sufficient authentication mechanism. You may still wish
1260 to set a password on the VNC server as a second authentication layer. The
1261 path following this option specifies where the x509 certificates are to
1262 be loaded from. See the @ref{vnc_security} section for details on generating
1267 Require that the client use SASL to authenticate with the VNC server.
1268 The exact choice of authentication method used is controlled from the
1269 system / user's SASL configuration file
for the
'qemu' service
. This
1270 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
1271 unprivileged user
, an environment variable SASL_CONF_PATH can be used
1272 to make it search alternate locations
for the service config
.
1273 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
1274 it is recommended that SASL always be combined with the
'tls' and
1275 'x509' settings to enable use of SSL and server certificates
. This
1276 ensures a data encryption preventing compromise of authentication
1277 credentials
. See the @ref
{vnc_security
} section
for details on
using
1278 SASL authentication
.
1282 Turn on access control lists
for checking of the x509 client certificate
1283 and SASL party
. For x509 certs
, the ACL check is made against the
1284 certificate
's distinguished name. This is something that looks like
1285 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1286 made against the username, which depending on the SASL plugin, may
1287 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1288 When the @option{acl} flag is set, the initial access list will be
1289 empty, with a @code{deny} policy. Thus no one will be allowed to
1290 use the VNC server until the ACLs have been loaded. This can be
1291 achieved using the @code{acl} monitor command.
1295 Enable lossy compression methods (gradient, JPEG, ...). If this
1296 option is set, VNC client may receive lossy framebuffer updates
1297 depending on its encoding settings. Enabling this option can save
1298 a lot of bandwidth at the expense of quality.
1302 Disable adaptive encodings. Adaptive encodings are enabled by default.
1303 An adaptive encoding will try to detect frequently updated screen regions,
1304 and send updates in these regions using a lossy encoding (like JPEG).
1305 This can be really helpful to save bandwidth when playing videos. Disabling
1306 adaptive encodings restores the original static behavior of encodings
1309 @item share=[allow-exclusive|force-shared|ignore]
1311 Set display sharing policy. 'allow
-exclusive
' allows clients to ask
1312 for exclusive access. As suggested by the rfb spec this is
1313 implemented by dropping other connections. Connecting multiple
1314 clients in parallel requires all clients asking for a shared session
1315 (vncviewer: -shared switch). This is the default. 'force
-shared
'
1316 disables exclusive client access. Useful for shared desktop sessions,
1317 where you don't want someone forgetting specify
-shared disconnect
1318 everybody
else. 'ignore' completely ignores the shared flag and
1319 allows everybody connect unconditionally
. Doesn
't conform to the rfb
1320 spec but is traditional QEMU behavior.
1328 ARCHHEADING(, QEMU_ARCH_I386)
1330 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1335 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1336 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1341 Use it when installing Windows 2000 to avoid a disk full bug. After
1342 Windows 2000 is installed, you no longer need this option (this option
1343 slows down the IDE transfers).
1346 HXCOMM Deprecated by -rtc
1347 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1349 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1350 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1353 @item -no-fd-bootchk
1354 @findex -no-fd-bootchk
1355 Disable boot signature checking for floppy disks in BIOS. May
1356 be needed to boot from old floppy disks.
1359 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1360 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1364 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1365 it if your guest OS complains about ACPI problems (PC target machine
1369 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1370 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1374 Disable HPET support.
1377 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1378 "-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"
1379 " ACPI table description\n", QEMU_ARCH_I386)
1381 @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}]...]
1383 Add ACPI table with specified header fields and context from specified files.
1384 For file=, take whole ACPI table from the specified files, including all
1385 ACPI headers (possible overridden by other options).
1386 For data=, only data
1387 portion of the table is used, all header information is specified in the
1391 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1392 "-smbios file=binary\n"
1393 " load SMBIOS entry from binary file\n"
1394 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1396 " specify SMBIOS type 0 fields\n"
1397 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1398 " [,uuid=uuid][,sku=str][,family=str]\n"
1399 " specify SMBIOS type 1 fields\n"
1400 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1401 " [,asset=str][,location=str]\n"
1402 " specify SMBIOS type 2 fields\n"
1403 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1405 " specify SMBIOS type 3 fields\n"
1406 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1407 " [,asset=str][,part=str]\n"
1408 " specify SMBIOS type 4 fields\n"
1409 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1410 " [,asset=str][,part=str][,speed=%d]\n"
1411 " specify SMBIOS type 17 fields\n",
1414 @item -smbios file=@var{binary}
1416 Load SMBIOS entry from binary file.
1418 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1419 Specify SMBIOS type 0 fields
1421 @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}]
1422 Specify SMBIOS type 1 fields
1424 @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}]
1425 Specify SMBIOS type 2 fields
1427 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1428 Specify SMBIOS type 3 fields
1430 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1431 Specify SMBIOS type 4 fields
1433 @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}]
1434 Specify SMBIOS type 17 fields
1442 DEFHEADING(Network options:)
1447 HXCOMM Legacy slirp options (now moved to -net user):
1449 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1450 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1451 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1453 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1457 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1459 "-netdev user,id=str[,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
1460 " [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n"
1461 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1463 "[,smb=dir[,smbserver=addr]]\n"
1465 " configure a user mode network backend with ID 'str
',\n"
1466 " its DHCP server and optional services\n"
1469 "-netdev tap,id=str,ifname=name\n"
1470 " configure a host TAP network backend with ID 'str
'\n"
1472 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1473 " [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1474 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1475 " configure a host TAP network backend with ID 'str
'\n"
1476 " use network scripts 'file
' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1477 " to configure it and 'dfile
' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1478 " to deconfigure it\n"
1479 " use '[down
]script
=no
' to disable script execution\n"
1480 " use network helper 'helper
' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1482 " use 'fd
=h
' to connect to an already opened TAP interface\n"
1483 " use 'fds
=x
:y
:...:z
' to connect to already opened multiqueue capable TAP interfaces\n"
1484 " use 'sndbuf
=nbytes
' to limit the size of the send buffer (the\n"
1485 " default is disabled 'sndbuf
=0' to enable flow control set 'sndbuf
=1048576')\n"
1486 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1487 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1488 " use vhost=on to enable experimental in kernel accelerator\n"
1489 " (only has effect for virtio guests which use MSIX)\n"
1490 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1491 " use 'vhostfd
=h
' to connect to an already opened vhost net device\n"
1492 " use 'vhostfds
=x
:y
:...:z to connect to multiple already opened vhost net devices
\n"
1493 " use
'queues=n' to specify the number of queues to be created
for multiqueue TAP
\n"
1494 "-netdev bridge
,id
=str
[,br
=bridge
][,helper
=helper
]\n"
1495 " configure a host TAP network backend with ID
'str' that is
\n"
1496 " connected to a
bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1497 " using the program
'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1500 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1501 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1502 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1503 " [,rxcookie=rxcookie][,offset=offset]\n"
1504 " configure a network backend with ID 'str
' connected to\n"
1505 " an Ethernet over L2TPv3 pseudowire.\n"
1506 " Linux kernel 3.3+ as well as most routers can talk\n"
1507 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1508 " VM to a router and even VM to Host. It is a nearly-universal\n"
1509 " standard (RFC3391). Note - this implementation uses static\n"
1510 " pre-configured tunnels (same as the Linux kernel).\n"
1511 " use 'src
=' to specify source address\n"
1512 " use 'dst
=' to specify destination address\n"
1513 " use 'udp
=on
' to specify udp encapsulation\n"
1514 " use 'srcport
=' to specify source udp port\n"
1515 " use 'dstport
=' to specify destination udp port\n"
1516 " use 'ipv6
=on
' to force v6\n"
1517 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1518 " well as a weak security measure\n"
1519 " use 'rxcookie
=0x012345678' to specify a rxcookie\n"
1520 " use 'txcookie
=0x012345678' to specify a txcookie\n"
1521 " use 'cookie64
=on
' to set cookie size to 64 bit, otherwise 32\n"
1522 " use 'counter
=off
' to force a 'cut
-down
' L2TPv3 with no counter\n"
1523 " use 'pincounter
=on
' to work around broken counter handling in peer\n"
1524 " use 'offset
=X
' to add an extra offset between header and data\n"
1526 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1527 " configure a network backend to connect to another network\n"
1528 " using a socket connection\n"
1529 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1530 " configure a network backend to connect to a multicast maddr and port\n"
1531 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1532 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1533 " configure a network backend to connect to another network\n"
1534 " using an UDP tunnel\n"
1536 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1537 " configure a network backend to connect to port 'n
' of a vde switch\n"
1538 " running on host and listening for incoming connections on 'socketpath
'.\n"
1539 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1540 " ownership and permissions for communication port.\n"
1542 #ifdef CONFIG_NETMAP
1543 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1544 " attach to the existing netmap-enabled network interface 'name
', or to a\n"
1545 " VALE port (created on the fly) called 'name
' ('nmname
' is name of the \n"
1546 " netmap device, defaults to '/dev
/netmap
')\n"
1548 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1549 " configure a vhost-user network, backed by a chardev 'dev
'\n"
1550 "-netdev hubport,id=str,hubid=n\n"
1551 " configure a hub port on QEMU VLAN 'n
'\n", QEMU_ARCH_ALL)
1552 DEF("net", HAS_ARG, QEMU_OPTION_net,
1553 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1554 " old way to create a new NIC and connect it to VLAN 'n
'\n"
1555 " (use the '-device devtype
,netdev
=str
' option if possible instead)\n"
1556 "-net dump[,vlan=n][,file=f][,len=n]\n"
1557 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
1558 "-net none use it alone to have zero network devices. If no -net option\n"
1559 " is provided, the default is '-net nic
-net user
'\n"
1569 #ifdef CONFIG_NETMAP
1572 "socket][,vlan=n][,option][,option][,...]\n"
1573 " old way to initialize a host network interface\n"
1574 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
1576 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1578 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1579 = 0 is the default). The NIC is an e1000 by default on the PC
1580 target. Optionally, the MAC address can be changed to @var{mac}, the
1581 device address set to @var{addr} (PCI cards only),
1582 and a @var{name} can be assigned for use in monitor commands.
1583 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1584 that the card should have; this option currently only affects virtio cards; set
1585 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1586 NIC is created. QEMU can emulate several different models of network card.
1587 Valid values for @var{type} are
1588 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1589 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1590 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1591 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1592 for a list of available devices for your target.
1594 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1596 @item -net user[,@var{option}][,@var{option}][,...]
1597 Use the user mode network stack which requires no administrator
1598 privilege to run. Valid options are:
1602 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1605 @item name=@var{name}
1606 Assign symbolic name for use in monitor commands.
1608 @item net=@var{addr}[/@var{mask}]
1609 Set IP network address the guest will see. Optionally specify the netmask,
1610 either in the form a.b.c.d or as number of valid top-most bits. Default is
1613 @item host=@var{addr}
1614 Specify the guest-visible address of the host. Default is the 2nd IP in the
1615 guest network, i.e. x.x.x.2.
1617 @item restrict=on|off
1618 If this option is enabled, the guest will be isolated, i.e. it will not be
1619 able to contact the host and no guest IP packets will be routed over the host
1620 to the outside. This option does not affect any explicitly set forwarding rules.
1622 @item hostname=@var{name}
1623 Specifies the client hostname reported by the built-in DHCP server.
1625 @item dhcpstart=@var{addr}
1626 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1627 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1629 @item dns=@var{addr}
1630 Specify the guest-visible address of the virtual nameserver. The address must
1631 be different from the host address. Default is the 3rd IP in the guest network,
1634 @item dnssearch=@var{domain}
1635 Provides an entry for the domain-search list sent by the built-in
1636 DHCP server. More than one domain suffix can be transmitted by specifying
1637 this option multiple times. If supported, this will cause the guest to
1638 automatically try to append the given domain suffix(es) in case a domain name
1639 can not be resolved.
1643 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1646 @item tftp=@var{dir}
1647 When using the user mode network stack, activate a built-in TFTP
1648 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1649 The TFTP client on the guest must be configured in binary mode (use the command
1650 @code{bin} of the Unix TFTP client).
1652 @item bootfile=@var{file}
1653 When using the user mode network stack, broadcast @var{file} as the BOOTP
1654 filename. In conjunction with @option{tftp}, this can be used to network boot
1655 a guest from a local directory.
1657 Example (using pxelinux):
1659 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1662 @item smb=@var{dir}[,smbserver=@var{addr}]
1663 When using the user mode network stack, activate a built-in SMB
1664 server so that Windows OSes can access to the host files in @file{@var{dir}}
1665 transparently. The IP address of the SMB server can be set to @var{addr}. By
1666 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1668 In the guest Windows OS, the line:
1672 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1673 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1675 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1677 Note that a SAMBA server must be installed on the host OS.
1678 QEMU was tested successfully with smbd versions from Red Hat 9,
1679 Fedora Core 3 and OpenSUSE 11.x.
1681 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1682 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1683 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1684 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1685 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1686 be bound to a specific host interface. If no connection type is set, TCP is
1687 used. This option can be given multiple times.
1689 For example, to redirect host X11 connection from screen 1 to guest
1690 screen 0, use the following:
1694 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1695 # this host xterm should open in the guest X11 server
1699 To redirect telnet connections from host port 5555 to telnet port on
1700 the guest, use the following:
1704 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1705 telnet localhost 5555
1708 Then when you use on the host @code{telnet localhost 5555}, you
1709 connect to the guest telnet server.
1711 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1712 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1713 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1714 to the character device @var{dev} or to a program executed by @var{cmd:command}
1715 which gets spawned for each connection. This option can be given multiple times.
1717 You can either use a chardev directly and have that one used throughout QEMU's
1718 lifetime
, like
in the following example
:
1721 # open
10.10.1.1:4321 on bootup
, connect
10.0.2.100:1234 to it whenever
1722 # the guest accesses it
1723 qemu
-net user
,guestfwd
=tcp
:10.0.2.100:1234-tcp
:10.10.1.1:4321 [...]
1726 Or you can execute a command on every TCP connection established by the guest
,
1727 so that QEMU behaves similar to an inetd process
for that virtual server
:
1730 # call
"netcat 10.10.1.1 4321" on every TCP connection to
10.0.2.100:1234
1731 # and connect the TCP stream to its stdin
/stdout
1732 qemu
-net
'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1737 Note
: Legacy stand
-alone options
-tftp
, -bootp
, -smb and
-redir are still
1738 processed and applied to
-net user
. Mixing them with the
new configuration
1739 syntax gives undefined results
. Their use
for new applications is discouraged
1740 as they will be removed from future versions
.
1742 @item
-netdev tap
,id
=@
var{id
}[,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1743 @item
-net tap
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1744 Connect the host TAP network
interface @
var{name
} to VLAN @
var{n
}.
1746 Use the network script @
var{file
} to configure it and the network script
1747 @
var{dfile
} to deconfigure it
. If @
var{name
} is not provided
, the OS
1748 automatically provides one
. The
default network configure script is
1749 @file
{/etc
/qemu
-ifup
} and the
default network deconfigure script is
1750 @file
{/etc
/qemu
-ifdown
}. Use @option
{script
=no
} or @option
{downscript
=no
}
1751 to disable script execution
.
1753 If running QEMU as an unprivileged user
, use the network helper
1754 @
var{helper
} to configure the TAP
interface. The
default network
1755 helper executable is @file
{/path
/to
/qemu
-bridge
-helper
}.
1757 @option
{fd
}=@
var{h
} can be used to specify the handle of an already
1758 opened host TAP
interface.
1763 #launch a QEMU instance with the
default network script
1764 qemu
-system
-i386 linux
.img
-net nic
-net tap
1768 #launch a QEMU instance with two NICs
, each one connected
1770 qemu
-system
-i386 linux
.img \
1771 -net nic
,vlan
=0 -net tap
,vlan
=0,ifname
=tap0 \
1772 -net nic
,vlan
=1 -net tap
,vlan
=1,ifname
=tap1
1776 #launch a QEMU instance with the
default network helper to
1777 #connect a TAP device to bridge br0
1778 qemu
-system
-i386 linux
.img \
1779 -net nic
-net tap
,"helper=/path/to/qemu-bridge-helper"
1782 @item
-netdev bridge
,id
=@
var{id
}[,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1783 @item
-net bridge
[,vlan
=@
var{n
}][,name
=@
var{name
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1784 Connect a host TAP network
interface to a host bridge device
.
1786 Use the network helper @
var{helper
} to configure the TAP
interface and
1787 attach it to the bridge
. The
default network helper executable is
1788 @file
{/path
/to
/qemu
-bridge
-helper
} and the
default bridge
1789 device is @file
{br0
}.
1794 #launch a QEMU instance with the
default network helper to
1795 #connect a TAP device to bridge br0
1796 qemu
-system
-i386 linux
.img
-net bridge
-net nic
,model
=virtio
1800 #launch a QEMU instance with the
default network helper to
1801 #connect a TAP device to bridge qemubr0
1802 qemu
-system
-i386 linux
.img
-net bridge
,br
=qemubr0
-net nic
,model
=virtio
1805 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1806 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}] [,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1808 Connect the VLAN @
var{n
} to a remote VLAN
in another QEMU virtual
1809 machine
using a TCP socket connection
. If @option
{listen
} is
1810 specified
, QEMU waits
for incoming connections on @
var{port
}
1811 (@
var{host
} is optional
). @option
{connect
} is used to connect to
1812 another QEMU instance
using the @option
{listen
} option
. @option
{fd
}=@
var{h
}
1813 specifies an already opened TCP socket
.
1817 # launch a first QEMU instance
1818 qemu
-system
-i386 linux
.img \
1819 -net nic
,macaddr
=52:54:00:12:34:56 \
1820 -net socket
,listen
=:1234
1821 # connect the VLAN
0 of
this instance to the VLAN
0
1822 # of the first instance
1823 qemu
-system
-i386 linux
.img \
1824 -net nic
,macaddr
=52:54:00:12:34:57 \
1825 -net socket
,connect
=127.0.0.1:1234
1828 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1829 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1831 Create a VLAN @
var{n
} shared with another QEMU virtual
1832 machines
using a UDP multicast socket
, effectively making a bus
for
1833 every QEMU with same multicast address @
var{maddr
} and @
var{port
}.
1837 Several QEMU can be running on different hosts and share same
bus (assuming
1838 correct multicast setup
for these hosts
).
1840 mcast support is compatible with User Mode
Linux (argument @option
{eth@
var{N
}=mcast
}), see
1841 @url
{http
://user-mode-linux.sf.net}.
1843 Use @option
{fd
=h
} to specify an already opened UDP multicast socket
.
1848 # launch one QEMU instance
1849 qemu
-system
-i386 linux
.img \
1850 -net nic
,macaddr
=52:54:00:12:34:56 \
1851 -net socket
,mcast
=230.0.0.1:1234
1852 # launch another QEMU instance on same
"bus"
1853 qemu
-system
-i386 linux
.img \
1854 -net nic
,macaddr
=52:54:00:12:34:57 \
1855 -net socket
,mcast
=230.0.0.1:1234
1856 # launch yet another QEMU instance on same
"bus"
1857 qemu
-system
-i386 linux
.img \
1858 -net nic
,macaddr
=52:54:00:12:34:58 \
1859 -net socket
,mcast
=230.0.0.1:1234
1862 Example (User Mode Linux compat
.):
1864 # launch QEMU
instance (note mcast address selected
1866 qemu-system-i386 linux.img \
1867 -net nic,macaddr=52:54:00:12:34:56 \
1868 -net socket,mcast=239.192.168.1:1102
1870 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1873 Example (send packets from host's
1.2.3.4):
1875 qemu
-system
-i386 linux
.img \
1876 -net nic
,macaddr
=52:54:00:12:34:56 \
1877 -net socket
,mcast
=239.192.168.1:1102,localaddr
=1.2.3.4
1880 @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
}]
1881 @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
}]
1882 Connect VLAN @
var{n
} to L2TPv3 pseudowire
. L2TPv3 (RFC3391
) is a popular
1883 protocol to transport
Ethernet (and other Layer
2) data frames between
1884 two systems
. It is present
in routers
, firewalls and the Linux kernel
1885 (from version
3.3 onwards
).
1887 This transport allows a VM to communicate to another VM
, router or firewall directly
.
1889 @item src
=@
var{srcaddr
}
1890 source
address (mandatory
)
1891 @item dst
=@
var{dstaddr
}
1892 destination
address (mandatory
)
1894 select udp
encapsulation (default is ip
).
1895 @item srcport
=@
var{srcport
}
1897 @item dstport
=@
var{dstport
}
1898 destination udp port
.
1900 force v6
, otherwise defaults to v4
.
1901 @item rxcookie
=@
var{rxcookie
}
1902 @item txcookie
=@
var{txcookie
}
1903 Cookies are a weak form of security
in the l2tpv3 specification
.
1904 Their
function is mostly to prevent misconfiguration
. By
default they are
32
1907 Set cookie size to
64 bit instead of the
default 32
1909 Force a
'cut-down' L2TPv3 with no counter as
in
1910 draft
-mkonstan
-l2tpext
-keyed
-ipv6
-tunnel
-00
1912 Work around broken counter handling
in peer
. This may also help on
1913 networks which have packet reorder
.
1914 @item offset
=@
var{offset
}
1915 Add an extra offset between header and data
1917 For example
, to attach a VM running on host
4.3.2.1 via L2TPv3 to the bridge br
-lan
1918 on the remote Linux host
1.2.3.4:
1920 # Setup tunnel on linux host
using raw ip as encapsulation
1922 ip l2tp add tunnel remote
4.3.2.1 local
1.2.3.4 tunnel_id
1 peer_tunnel_id
1 \
1923 encap udp udp_sport
16384 udp_dport
16384
1924 ip l2tp add session tunnel_id
1 name vmtunnel0 session_id \
1925 0xFFFFFFFF peer_session_id
0xFFFFFFFF
1926 ifconfig vmtunnel0 mtu
1500
1927 ifconfig vmtunnel0 up
1928 brctl addif br
-lan vmtunnel0
1932 # launch QEMU instance
- if your network has reorder or is very lossy add
,pincounter
1934 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
1939 @item
-netdev vde
,id
=@
var{id
}[,sock
=@
var{socketpath
}][,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1940 @item
-net vde
[,vlan
=@
var{n
}][,name
=@
var{name
}][,sock
=@
var{socketpath
}] [,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1941 Connect VLAN @
var{n
} to PORT @
var{n
} of a vde
switch running on host and
1942 listening
for incoming connections on @
var{socketpath
}. Use GROUP @
var{groupname
}
1943 and MODE @
var{octalmode
} to change
default ownership and permissions
for
1944 communication port
. This option is only available
if QEMU has been compiled
1945 with vde support enabled
.
1950 vde_switch
-F
-sock
/tmp
/myswitch
1951 # launch QEMU instance
1952 qemu
-system
-i386 linux
.img
-net nic
-net vde
,sock
=/tmp
/myswitch
1955 @item
-netdev hubport
,id
=@
var{id
},hubid
=@
var{hubid
}
1957 Create a hub port on QEMU
"vlan" @
var{hubid
}.
1959 The hubport netdev lets you connect a NIC to a QEMU
"vlan" instead of a single
1960 netdev
. @code
{-net
} and @code
{-device
} with parameter @option
{vlan
} create the
1961 required hub automatically
.
1963 @item
-netdev vhost
-user
,chardev
=@
var{id
}[,vhostforce
=on|off
][,queues
=n
]
1965 Establish a vhost
-user netdev
, backed by a chardev @
var{id
}. The chardev should
1966 be a unix domain socket backed one
. The vhost
-user uses a specifically defined
1967 protocol to pass vhost ioctl replacement messages to an application on the other
1968 end of the socket
. On non
-MSIX guests
, the feature can be forced with
1969 @
var{vhostforce
}. Use
'queues=@var{n}' to specify the number of queues to
1970 be created
for multiqueue vhost
-user
.
1974 qemu
-m
512 -object memory
-backend
-file
,id
=mem
,size
=512M
,mem
-path
=/hugetlbfs
,share
=on \
1975 -numa node
,memdev
=mem \
1976 -chardev socket
,path
=/path
/to
/socket \
1977 -netdev type
=vhost
-user
,id
=net0
,chardev
=chr0 \
1978 -device virtio
-net
-pci
,netdev
=net0
1981 @item
-net dump
[,vlan
=@
var{n
}][,file
=@
var{file
}][,len
=@
var{len
}]
1982 Dump network traffic on VLAN @
var{n
} to file @
var{file
} (@file
{qemu
-vlan0
.pcap
} by
default).
1983 At most @
var{len
} bytes (64k by
default) per packet are stored
. The file format is
1984 libpcap
, so it can be analyzed with tools such as tcpdump or Wireshark
.
1987 Indicate that no network devices should be configured
. It is used to
1988 override the
default configuration (@option
{-net nic
-net user
}) which
1989 is activated
if no @option
{-net
} options are provided
.
1997 DEFHEADING(Character device options
:)
2000 The general form of a character device option is
:
2004 DEF("chardev", HAS_ARG
, QEMU_OPTION_chardev
,
2005 "-chardev null,id=id[,mux=on|off]\n"
2006 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2007 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (tcp)\n"
2008 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (unix)\n"
2009 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2010 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2011 "-chardev msmouse,id=id[,mux=on|off]\n"
2012 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2014 "-chardev ringbuf,id=id[,size=size]\n"
2015 "-chardev file,id=id,path=path[,mux=on|off]\n"
2016 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
2018 "-chardev console,id=id[,mux=on|off]\n"
2019 "-chardev serial,id=id,path=path[,mux=on|off]\n"
2021 "-chardev pty,id=id[,mux=on|off]\n"
2022 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
2024 #ifdef CONFIG_BRLAPI
2025 "-chardev braille,id=id[,mux=on|off]\n"
2027 #
if defined(__linux__
) ||
defined(__sun__
) ||
defined(__FreeBSD__
) \
2028 ||
defined(__NetBSD__
) ||
defined(__OpenBSD__
) ||
defined(__DragonFly__
)
2029 "-chardev serial,id=id,path=path[,mux=on|off]\n"
2030 "-chardev tty,id=id,path=path[,mux=on|off]\n"
2032 #
if defined(__linux__
) ||
defined(__FreeBSD__
) ||
defined(__DragonFly__
)
2033 "-chardev parallel,id=id,path=path[,mux=on|off]\n"
2034 "-chardev parport,id=id,path=path[,mux=on|off]\n"
2036 #
if defined(CONFIG_SPICE
)
2037 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
2038 "-chardev spiceport,id=id,name=name[,debug=debug]\n"
2044 @item
-chardev @
var{backend
} ,id
=@
var{id
} [,mux
=on|off
] [,@
var{options
}]
2065 The specific backend will determine the applicable options
.
2067 All devices must have an id
, which can be any string up to
127 characters long
.
2068 It is used to uniquely identify
this device
in other command line directives
.
2070 A character device may be used
in multiplexing mode by multiple front
-ends
.
2071 The key sequence of @key
{Control
-a
} and @key
{c
} will rotate the input focus
2072 between attached front
-ends
. Specify @option
{mux
=on
} to enable
this mode
.
2074 Options to each backend are described below
.
2076 @item
-chardev
null ,id
=@
var{id
}
2077 A void device
. This device will not emit any data
, and will drop any data it
2078 receives
. The
null backend does not take any options
.
2080 @item
-chardev socket
,id
=@
var{id
} [@
var{TCP options
} or @
var{unix options
}] [,server
] [,nowait
] [,telnet
] [,reconnect
=@
var{seconds
}]
2082 Create a two
-way stream socket
, which can be either a TCP or a unix socket
. A
2083 unix socket will be created
if @option
{path
} is specified
. Behaviour is
2084 undefined
if TCP options are specified
for a unix socket
.
2086 @option
{server
} specifies that the socket shall be a listening socket
.
2088 @option
{nowait
} specifies that QEMU should not block waiting
for a client to
2089 connect to a listening socket
.
2091 @option
{telnet
} specifies that traffic on the socket should interpret telnet
2094 @option
{reconnect
} sets the timeout
for reconnecting on non
-server sockets when
2095 the remote end goes away
. qemu will delay
this many seconds and then attempt
2096 to reconnect
. Zero disables reconnecting
, and is the
default.
2098 TCP and unix socket options are given below
:
2102 @item TCP options
: port
=@
var{port
} [,host
=@
var{host
}] [,to
=@
var{to
}] [,ipv4
] [,ipv6
] [,nodelay
]
2104 @option
{host
} for a listening socket specifies the local address to be bound
.
2105 For a connecting socket species the remote host to connect to
. @option
{host
} is
2106 optional
for listening sockets
. If not specified it defaults to @code
{0.0.0.0}.
2108 @option
{port
} for a listening socket specifies the local port to be bound
. For a
2109 connecting socket specifies the port on the remote host to connect to
.
2110 @option
{port
} can be given as either a port number or a service name
.
2111 @option
{port
} is required
.
2113 @option
{to
} is only relevant to listening sockets
. If it is specified
, and
2114 @option
{port
} cannot be bound
, QEMU will attempt to bind to subsequent ports up
2115 to and including @option
{to
} until it succeeds
. @option
{to
} must be specified
2118 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2119 If neither is specified the socket may use either protocol
.
2121 @option
{nodelay
} disables the Nagle algorithm
.
2123 @item unix options
: path
=@
var{path
}
2125 @option
{path
} specifies the local path of the unix socket
. @option
{path
} is
2130 @item
-chardev udp
,id
=@
var{id
} [,host
=@
var{host
}] ,port
=@
var{port
} [,localaddr
=@
var{localaddr
}] [,localport
=@
var{localport
}] [,ipv4
] [,ipv6
]
2132 Sends all traffic from the guest to a remote host over UDP
.
2134 @option
{host
} specifies the remote host to connect to
. If not specified it
2135 defaults to @code
{localhost
}.
2137 @option
{port
} specifies the port on the remote host to connect to
. @option
{port
}
2140 @option
{localaddr
} specifies the local address to bind to
. If not specified it
2141 defaults to @code
{0.0.0.0}.
2143 @option
{localport
} specifies the local port to bind to
. If not specified any
2144 available local port will be used
.
2146 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2147 If neither is specified the device may use either protocol
.
2149 @item
-chardev msmouse
,id
=@
var{id
}
2151 Forward QEMU
's emulated msmouse events to the guest. @option{msmouse} does not
2154 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2156 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2159 @option{width} and @option{height} specify the width and height respectively of
2160 the console, in pixels.
2162 @option{cols} and @option{rows} specify that the console be sized to fit a text
2163 console with the given dimensions.
2165 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2167 Create a ring buffer with fixed size @option{size}.
2168 @var{size} must be a power of two, and defaults to @code{64K}).
2170 @item -chardev file ,id=@var{id} ,path=@var{path}
2172 Log all traffic received from the guest to a file.
2174 @option{path} specifies the path of the file to be opened. This file will be
2175 created if it does not already exist, and overwritten if it does. @option{path}
2178 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2180 Create a two-way connection to the guest. The behaviour differs slightly between
2181 Windows hosts and other hosts:
2183 On Windows, a single duplex pipe will be created at
2184 @file{\\.pipe\@option{path}}.
2186 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2187 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2188 received by the guest. Data written by the guest can be read from
2189 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2192 @option{path} forms part of the pipe path as described above. @option{path} is
2195 @item -chardev console ,id=@var{id}
2197 Send traffic from the guest to QEMU's standard output
. @option
{console
} does not
2200 @option
{console
} is only available on Windows hosts
.
2202 @item
-chardev serial
,id
=@
var{id
} ,path
=@option
{path
}
2204 Send traffic from the guest to a serial device on the host
.
2206 On Unix hosts serial will actually accept any tty device
,
2207 not only serial lines
.
2209 @option
{path
} specifies the name of the serial device to open
.
2211 @item
-chardev pty
,id
=@
var{id
}
2213 Create a
new pseudo
-terminal on the host and connect to it
. @option
{pty
} does
2214 not take any options
.
2216 @option
{pty
} is not available on Windows hosts
.
2218 @item
-chardev stdio
,id
=@
var{id
} [,signal
=on|off
]
2219 Connect to standard input and standard output of the QEMU process
.
2221 @option
{signal
} controls
if signals are enabled on the terminal
, that includes
2222 exiting QEMU with the key sequence @key
{Control
-c
}. This option is enabled by
2223 default, use @option
{signal
=off
} to disable it
.
2225 @option
{stdio
} is not available on Windows hosts
.
2227 @item
-chardev braille
,id
=@
var{id
}
2229 Connect to a local BrlAPI server
. @option
{braille
} does not take any options
.
2231 @item
-chardev tty
,id
=@
var{id
} ,path
=@
var{path
}
2233 @option
{tty
} is only available on Linux
, Sun
, FreeBSD
, NetBSD
, OpenBSD and
2234 DragonFlyBSD hosts
. It is an alias
for @option
{serial
}.
2236 @option
{path
} specifies the path to the tty
. @option
{path
} is required
.
2238 @item
-chardev parallel
,id
=@
var{id
} ,path
=@
var{path
}
2239 @item
-chardev parport
,id
=@
var{id
} ,path
=@
var{path
}
2241 @option
{parallel
} is only available on Linux
, FreeBSD and DragonFlyBSD hosts
.
2243 Connect to a local parallel port
.
2245 @option
{path
} specifies the path to the parallel port device
. @option
{path
} is
2248 @item
-chardev spicevmc
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2250 @option
{spicevmc
} is only available when spice support is built
in.
2252 @option
{debug
} debug level
for spicevmc
2254 @option
{name
} name of spice channel to connect to
2256 Connect to a spice virtual machine channel
, such as vdiport
.
2258 @item
-chardev spiceport
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2260 @option
{spiceport
} is only available when spice support is built
in.
2262 @option
{debug
} debug level
for spicevmc
2264 @option
{name
} name of spice port to connect to
2266 Connect to a spice port
, allowing a Spice client to handle the traffic
2267 identified by a
name (preferably a fqdn
).
2275 DEFHEADING(Device URL Syntax
:)
2278 In addition to
using normal file images
for the emulated storage devices
,
2279 QEMU can also use networked resources such as iSCSI devices
. These are
2280 specified
using a special URL syntax
.
2284 iSCSI support allows QEMU to access iSCSI resources directly and use as
2285 images
for the guest storage
. Both disk and cdrom images are supported
.
2287 Syntax
for specifying iSCSI LUNs is
2288 ``iscsi
://<target-ip>[:<port>]/<target-iqn>/<lun>''
2290 By
default qemu will use the iSCSI initiator
-name
2291 'iqn.2008-11.org.linux-kvm[:<name>]' but
this can also be set from the command
2292 line or a configuration file
.
2295 Example (without authentication
):
2297 qemu
-system
-i386
-iscsi initiator
-name
=iqn
.2001-04.com
.example
:my
-initiator \
2298 -cdrom iscsi
://192.0.2.1/iqn.2001-04.com.example/2 \
2299 -drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2302 Example (CHAP username
/password via URL
):
2304 qemu
-system
-i386
-drive file
=iscsi
://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2307 Example (CHAP username
/password via environment variables
):
2309 LIBISCSI_CHAP_USERNAME
="user" \
2310 LIBISCSI_CHAP_PASSWORD
="password" \
2311 qemu
-system
-i386
-drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2314 iSCSI support is an optional feature of QEMU and only available when
2315 compiled and linked against libiscsi
.
2317 DEF("iscsi", HAS_ARG
, QEMU_OPTION_iscsi
,
2318 "-iscsi [user=user][,password=password]\n"
2319 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2320 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2321 " iSCSI session parameters\n", QEMU_ARCH_ALL
)
2324 iSCSI parameters such as username and password can also be specified via
2325 a configuration file
. See qemu
-doc
for more information and examples
.
2328 QEMU supports
NBD (Network Block Devices
) both
using TCP protocol as well
2329 as Unix Domain Sockets
.
2331 Syntax
for specifying a NBD device
using TCP
2332 ``nbd
:<server
-ip
>:<port
>[:exportname
=<export
>]''
2334 Syntax
for specifying a NBD device
using Unix Domain Sockets
2335 ``nbd
:unix
:<domain
-socket
>[:exportname
=<export
>]''
2340 qemu
-system
-i386
--drive file
=nbd
:192.0.2.1:30000
2343 Example
for Unix Domain Sockets
2345 qemu
-system
-i386
--drive file
=nbd
:unix
:/tmp
/nbd
-socket
2349 QEMU supports
SSH (Secure Shell
) access to remote disks
.
2353 qemu
-system
-i386
-drive file
=ssh
://user@@host/path/to/disk.img
2354 qemu
-system
-i386
-drive file
.driver
=ssh
,file
.user
=user
,file
.host
=host
,file
.port
=22,file
.path
=/path
/to
/disk
.img
2357 Currently authentication must be done
using ssh
-agent
. Other
2358 authentication methods may be supported
in future
.
2361 Sheepdog is a distributed storage system
for QEMU
.
2362 QEMU supports
using either local sheepdog devices or remote networked
2365 Syntax
for specifying a sheepdog device
2367 sheepdog
[+tcp|
+unix
]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2372 qemu
-system
-i386
--drive file
=sheepdog
://192.0.2.1:30000/MyVirtualMachine
2375 See also @url
{http
://http://www.osrg.net/sheepdog/}.
2378 GlusterFS is an user space distributed file system
.
2379 QEMU supports the use of GlusterFS volumes
for hosting VM disk images
using
2380 TCP
, Unix Domain Sockets and RDMA transport protocols
.
2382 Syntax
for specifying a VM disk image on GlusterFS volume is
2384 gluster
[+transport
]://[server[:port]]/volname/image[?socket=...]
2390 qemu
-system
-x86_64
--drive file
=gluster
://192.0.2.1/testvol/a.img
2393 See also @url
{http
://www.gluster.org}.
2395 @item HTTP
/HTTPS
/FTP
/FTPS
/TFTP
2396 QEMU supports read
-only access to files accessed over
http(s
), ftp(s
) and tftp
.
2398 Syntax
using a single filename
:
2400 <protocol
>://[<username>[:<password>]@@]<host>/<path>
2406 'http', 'https', 'ftp', 'ftps', or
'tftp'.
2409 Optional username
for authentication to the remote server
.
2412 Optional password
for authentication to the remote server
.
2415 Address of the remote server
.
2418 Path on the remote server
, including any query string
.
2421 The following options are also supported
:
2424 The full URL when passing options to the driver explicitly
.
2427 The amount of data to read ahead with each range request to the remote server
.
2428 This value may optionally have the suffix
'T', 'G', 'M', 'K', 'k' or
'b'. If it
2429 does not have a suffix
, it will be assumed to be
in bytes
. The value must be a
2430 multiple of
512 bytes
. It defaults to
256k
.
2433 Whether to verify the remote server
's certificate when connecting over SSL. It
2434 can have the value 'on
' or 'off
'. It defaults to 'on
'.
2437 Send this cookie (it can also be a list of cookies separated by ';') with
2438 each outgoing request. Only supported when using protocols such as HTTP
2439 which support cookies, otherwise ignored.
2442 Set the timeout in seconds of the CURL connection. This timeout is the time
2443 that CURL waits for a response from the remote server to get the size of the
2444 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2447 Note that when passing options to qemu explicitly, @option{driver} is the value
2450 Example: boot from a remote Fedora 20 live ISO image
2452 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
2454 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
2457 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2458 writes, copy-on-read, and a readahead of 64k
2460 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
2462 qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
2465 Example: boot from an image stored on a VMware vSphere server with a self-signed
2466 certificate using a local overlay for writes, a readahead of 64k and a timeout
2469 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
2471 qemu-system-x86_64 -drive file=/tmp/test.qcow2
2479 DEFHEADING(Bluetooth(R) options:)
2484 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2485 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands
\n" \
2486 "-bt hci
,host
[:id
]\n" \
2487 " use host
's HCI with the given name\n" \
2488 "-bt hci[,vlan=n]\n" \
2489 " emulate a standard HCI in virtual scatternet 'n
'\n" \
2490 "-bt vhci[,vlan=n]\n" \
2491 " add host computer to virtual scatternet 'n
' using VHCI\n" \
2492 "-bt device:dev[,vlan=n]\n" \
2493 " emulate a bluetooth device 'dev
' in scatternet 'n
'\n",
2498 Defines the function of the corresponding Bluetooth HCI. -bt options
2499 are matched with the HCIs present in the chosen machine type. For
2500 example when emulating a machine with only one HCI built into it, only
2501 the first @code{-bt hci[...]} option is valid and defines the HCI's
2502 logic
. The Transport Layer is decided by the machine type
. Currently
2503 the machines @code
{n800
} and @code
{n810
} have one HCI and all other
2507 The following three types are recognized
:
2511 (default) The corresponding Bluetooth HCI assumes no internal logic
2512 and will not respond to any HCI commands or emit events
.
2514 @item
-bt hci
,host
[:@
var{id
}]
2515 (@code
{bluez
} only
) The corresponding HCI passes commands
/ events
2516 to
/ from the physical HCI identified by the name @
var{id
} (default:
2517 @code
{hci0
}) on the computer running QEMU
. Only available on @code
{bluez
}
2518 capable systems like Linux
.
2520 @item
-bt hci
[,vlan
=@
var{n
}]
2521 Add a virtual
, standard HCI that will participate
in the Bluetooth
2522 scatternet @
var{n
} (default @code
{0}). Similarly to @option
{-net
}
2523 VLANs
, devices inside a bluetooth network @
var{n
} can only communicate
2524 with other devices
in the same
network (scatternet
).
2527 @item
-bt vhci
[,vlan
=@
var{n
}]
2528 (Linux
-host only
) Create a HCI
in scatternet @
var{n
} (default 0) attached
2529 to the host bluetooth stack instead of to the emulated target
. This
2530 allows the host and target machines to participate
in a common scatternet
2531 and communicate
. Requires the Linux @code
{vhci
} driver installed
. Can
2532 be used as following
:
2535 qemu
-system
-i386
[...OPTIONS
...] -bt hci
,vlan
=5 -bt vhci
,vlan
=5
2538 @item
-bt device
:@
var{dev
}[,vlan
=@
var{n
}]
2539 Emulate a bluetooth device @
var{dev
} and place it
in network @
var{n
}
2540 (default @code
{0}). QEMU can only emulate one type of bluetooth devices
2545 Virtual wireless keyboard implementing the HIDP bluetooth profile
.
2555 DEFHEADING(TPM device options
:)
2557 DEF("tpmdev", HAS_ARG
, QEMU_OPTION_tpmdev
, \
2558 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2559 " use path to provide path to a character device; default is /dev/tpm0\n"
2560 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2561 " not provided it will be searched for in /sys/class/misc/tpm?/device\n",
2565 The general form of a TPM device option is
:
2568 @item
-tpmdev @
var{backend
} ,id
=@
var{id
} [,@
var{options
}]
2570 Backend type must be
:
2571 @option
{passthrough
}.
2573 The specific backend type will determine the applicable options
.
2574 The @code
{-tpmdev
} option creates the TPM backend and requires a
2575 @code
{-device
} option that specifies the TPM frontend
interface model
.
2577 Options to each backend are described below
.
2579 Use
'help' to print all available TPM backend types
.
2584 @item
-tpmdev passthrough
, id
=@
var{id
}, path
=@
var{path
}, cancel
-path
=@
var{cancel
-path
}
2586 (Linux
-host only
) Enable access to the host
's TPM using the passthrough
2589 @option{path} specifies the path to the host's TPM device
, i
.e
., on
2590 a Linux host
this would be @code
{/dev
/tpm0
}.
2591 @option
{path
} is optional and by
default @code
{/dev
/tpm0
} is used
.
2593 @option
{cancel
-path
} specifies the path to the host TPM device
's sysfs
2594 entry allowing for cancellation of an ongoing TPM command.
2595 @option{cancel-path} is optional and by default QEMU will search for the
2598 Some notes about using the host's TPM with the passthrough driver
:
2600 The TPM device accessed by the passthrough driver must not be
2601 used by any other application on the host
.
2603 Since the host
's firmware (BIOS/UEFI) has already initialized the TPM,
2604 the VM's
firmware (BIOS
/UEFI
) will not be able to initialize the
2605 TPM again and may therefore not show a TPM
-specific menu that would
2606 otherwise allow the user to configure the TPM
, e
.g
., allow the user to
2607 enable
/disable or activate
/deactivate the TPM
.
2608 Further
, if TPM ownership is released from within a VM then the host
's TPM
2609 will get disabled and deactivated. To enable and activate the
2610 TPM again afterwards, the host has to be rebooted and the user is
2611 required to enter the firmware's menu to enable and activate the TPM
.
2612 If the TPM is left disabled and
/or deactivated most TPM commands will fail
.
2614 To create a passthrough TPM use the following two options
:
2616 -tpmdev passthrough
,id
=tpm0
-device tpm
-tis
,tpmdev
=tpm0
2618 Note that the @code
{-tpmdev
} id is @code
{tpm0
} and is referenced by
2619 @code
{tpmdev
=tpm0
} in the device option
.
2629 DEFHEADING(Linux
/Multiboot boot specific
:)
2632 When
using these options
, you can use a given Linux or Multiboot
2633 kernel without installing it
in the disk image
. It can be useful
2634 for easier testing of various kernels
.
2639 DEF("kernel", HAS_ARG
, QEMU_OPTION_kernel
, \
2640 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL
)
2642 @item
-kernel @
var{bzImage
}
2644 Use @
var{bzImage
} as kernel image
. The kernel can be either a Linux kernel
2645 or
in multiboot format
.
2648 DEF("append", HAS_ARG
, QEMU_OPTION_append
, \
2649 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL
)
2651 @item
-append @
var{cmdline
}
2653 Use @
var{cmdline
} as kernel command line
2656 DEF("initrd", HAS_ARG
, QEMU_OPTION_initrd
, \
2657 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL
)
2659 @item
-initrd @
var{file
}
2661 Use @
var{file
} as initial ram disk
.
2663 @item
-initrd
"@var{file1} arg=foo,@var{file2}"
2665 This syntax is only available with multiboot
.
2667 Use @
var{file1
} and @
var{file2
} as modules and pass arg
=foo as parameter to the
2671 DEF("dtb", HAS_ARG
, QEMU_OPTION_dtb
, \
2672 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL
)
2674 @item
-dtb @
var{file
}
2676 Use @
var{file
} as a device tree
binary (dtb
) image and pass it to the kernel
2685 DEFHEADING(Debug
/Expert options
:)
2690 DEF("fw_cfg", HAS_ARG
, QEMU_OPTION_fwcfg
,
2691 "-fw_cfg [name=]<name>,file=<file>\n"
2692 " add named fw_cfg entry from file\n",
2695 @item
-fw_cfg
[name
=]@
var{name
},file
=@
var{file
}
2697 Add named fw_cfg entry from file
. @
var{name
} determines the name of
2698 the entry
in the fw_cfg file directory exposed to the guest
.
2701 DEF("serial", HAS_ARG
, QEMU_OPTION_serial
, \
2702 "-serial dev redirect the serial port to char device 'dev'\n",
2705 @item
-serial @
var{dev
}
2707 Redirect the virtual serial port to host character device
2708 @
var{dev
}. The
default device is @code
{vc
} in graphical mode and
2709 @code
{stdio
} in non graphical mode
.
2711 This option can be used several times to simulate up to
4 serial
2714 Use @code
{-serial none
} to disable all serial ports
.
2716 Available character devices are
:
2718 @item vc
[:@
var{W
}x@
var{H
}]
2719 Virtual console
. Optionally
, a width and height can be given
in pixel with
2723 It is also possible to specify width or height
in characters
:
2728 [Linux only
] Pseudo
TTY (a
new PTY is automatically allocated
)
2730 No device is allocated
.
2733 @item chardev
:@
var{id
}
2734 Use a named character device defined with the @code
{-chardev
} option
.
2736 [Linux only
] Use host tty
, e
.g
. @file
{/dev
/ttyS0
}. The host serial port
2737 parameters are set according to the emulated ones
.
2738 @item
/dev
/parport@
var{N
}
2739 [Linux only
, parallel port only
] Use host parallel port
2740 @
var{N
}. Currently SPP and EPP parallel port features can be used
.
2741 @item file
:@
var{filename
}
2742 Write output to @
var{filename
}. No character can be read
.
2744 [Unix only
] standard input
/output
2745 @item pipe
:@
var{filename
}
2746 name pipe @
var{filename
}
2748 [Windows only
] Use host serial port @
var{n
}
2749 @item udp
:[@
var{remote_host
}]:@
var{remote_port
}[@@
[@
var{src_ip
}]:@
var{src_port
}]
2750 This
implements UDP Net Console
.
2751 When @
var{remote_host
} or @
var{src_ip
} are not specified
2752 they
default to @code
{0.0.0.0}.
2753 When not
using a specified @
var{src_port
} a random port is automatically chosen
.
2755 If you just want a simple readonly console you can use @code
{netcat
} or
2756 @code
{nc
}, by starting QEMU with
: @code
{-serial udp
::4555} and nc as
:
2757 @code
{nc
-u
-l
-p
4555}. Any time QEMU writes something to that port it
2758 will appear
in the netconsole session
.
2760 If you plan to send characters back via netconsole or you want to stop
2761 and start QEMU a lot of times
, you should have QEMU use the same
2762 source port each time by
using something like @code
{-serial
2763 udp
::4555@@
:4556} to QEMU
. Another approach is to use a patched
2764 version of netcat which can listen to a TCP port and send and receive
2765 characters via udp
. If you have a patched version of netcat which
2766 activates telnet remote echo and single char transfer
, then you can
2767 use the following options to step up a netcat redirector to allow
2768 telnet on port
5555 to access the QEMU port
.
2771 -serial udp
::4555@@
:4556
2772 @item netcat options
:
2773 -u
-P
4555 -L
0.0.0.0:4556 -t
-p
5555 -I
-T
2774 @item telnet options
:
2778 @item tcp
:[@
var{host
}]:@
var{port
}[,@
var{server
}][,nowait
][,nodelay
][,reconnect
=@
var{seconds
}]
2779 The TCP Net Console has two modes of operation
. It can send the serial
2780 I
/O to a location or wait
for a connection from a location
. By
default
2781 the TCP Net Console is sent to @
var{host
} at the @
var{port
}. If you use
2782 the @
var{server
} option QEMU will wait
for a client socket application
2783 to connect to the port before continuing
, unless the @code
{nowait
}
2784 option was specified
. The @code
{nodelay
} option disables the Nagle buffering
2785 algorithm
. The @code
{reconnect
} option only applies
if @
var{noserver
} is
2786 set
, if the connection goes down it will attempt to reconnect at the
2787 given interval
. If @
var{host
} is omitted
, 0.0.0.0 is assumed
. Only
2788 one TCP connection at a time is accepted
. You can use @code
{telnet
} to
2789 connect to the corresponding character device
.
2791 @item Example to send tcp console to
192.168.0.2 port
4444
2792 -serial tcp
:192.168.0.2:4444
2793 @item Example to listen and wait on port
4444 for connection
2794 -serial tcp
::4444,server
2795 @item Example to not wait and listen on ip
192.168.0.100 port
4444
2796 -serial tcp
:192.168.0.100:4444,server
,nowait
2799 @item telnet
:@
var{host
}:@
var{port
}[,server
][,nowait
][,nodelay
]
2800 The telnet protocol is used instead of raw tcp sockets
. The options
2801 work the same as
if you had specified @code
{-serial tcp
}. The
2802 difference is that the port acts like a telnet server or client
using
2803 telnet option negotiation
. This will also allow you to send the
2804 MAGIC_SYSRQ sequence
if you use a telnet that supports sending the
break
2805 sequence
. Typically
in unix telnet you
do it with Control
-] and then
2806 type
"send break" followed by pressing the enter key
.
2808 @item unix
:@
var{path
}[,server
][,nowait
][,reconnect
=@
var{seconds
}]
2809 A unix domain socket is used instead of a tcp socket
. The option works the
2810 same as
if you had specified @code
{-serial tcp
} except the unix domain socket
2811 @
var{path
} is used
for connections
.
2813 @item mon
:@
var{dev_string
}
2814 This is a special option to allow the monitor to be multiplexed onto
2815 another serial port
. The monitor is accessed with key sequence of
2816 @key
{Control
-a
} and then pressing @key
{c
}.
2817 @
var{dev_string
} should be any one of the serial devices specified
2818 above
. An example to multiplex the monitor onto a telnet server
2819 listening on port
4444 would be
:
2821 @item
-serial mon
:telnet
::4444,server
,nowait
2823 When the monitor is multiplexed to stdio
in this way
, Ctrl
+C will not terminate
2824 QEMU any more but will be passed to the guest instead
.
2827 Braille device
. This will use BrlAPI to display the braille output on a real
2831 Three button serial mouse
. Configure the guest to use Microsoft protocol
.
2835 DEF("parallel", HAS_ARG
, QEMU_OPTION_parallel
, \
2836 "-parallel dev redirect the parallel port to char device 'dev'\n",
2839 @item
-parallel @
var{dev
}
2841 Redirect the virtual parallel port to host device @
var{dev
} (same
2842 devices as the serial port
). On Linux hosts
, @file
{/dev
/parportN
} can
2843 be used to use hardware devices connected on the corresponding host
2846 This option can be used several times to simulate up to
3 parallel
2849 Use @code
{-parallel none
} to disable all parallel ports
.
2852 DEF("monitor", HAS_ARG
, QEMU_OPTION_monitor
, \
2853 "-monitor dev redirect the monitor to char device 'dev'\n",
2856 @item
-monitor @
var{dev
}
2858 Redirect the monitor to host device @
var{dev
} (same devices as the
2860 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2862 Use @code
{-monitor none
} to disable the
default monitor
.
2864 DEF("qmp", HAS_ARG
, QEMU_OPTION_qmp
, \
2865 "-qmp dev like -monitor but opens in 'control' mode\n",
2868 @item
-qmp @
var{dev
}
2870 Like
-monitor but opens
in 'control' mode
.
2872 DEF("qmp-pretty", HAS_ARG
, QEMU_OPTION_qmp_pretty
, \
2873 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
2876 @item
-qmp
-pretty @
var{dev
}
2878 Like
-qmp but uses pretty JSON formatting
.
2881 DEF("mon", HAS_ARG
, QEMU_OPTION_mon
, \
2882 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL
)
2884 @item
-mon
[chardev
=]name
[,mode
=readline|control
][,default]
2886 Setup monitor on chardev @
var{name
}.
2889 DEF("debugcon", HAS_ARG
, QEMU_OPTION_debugcon
, \
2890 "-debugcon dev redirect the debug console to char device 'dev'\n",
2893 @item
-debugcon @
var{dev
}
2895 Redirect the debug console to host device @
var{dev
} (same devices as the
2896 serial port
). The debug console is an I
/O port which is typically port
2897 0xe9; writing to that I
/O port sends output to
this device
.
2898 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2902 DEF("pidfile", HAS_ARG
, QEMU_OPTION_pidfile
, \
2903 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL
)
2905 @item
-pidfile @
var{file
}
2907 Store the QEMU process PID
in @
var{file
}. It is useful
if you launch QEMU
2911 DEF("singlestep", 0, QEMU_OPTION_singlestep
, \
2912 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL
)
2916 Run the emulation
in single step mode
.
2919 DEF("S", 0, QEMU_OPTION_S
, \
2920 "-S freeze CPU at startup (use 'c' to start execution)\n",
2925 Do not start CPU at
startup (you must type
'c' in the monitor
).
2928 DEF("realtime", HAS_ARG
, QEMU_OPTION_realtime
,
2929 "-realtime [mlock=on|off]\n"
2930 " run qemu with realtime features\n"
2931 " mlock=on|off controls mlock support (default: on)\n",
2934 @item
-realtime mlock
=on|off
2936 Run qemu with realtime features
.
2937 mlocking qemu and guest memory can be enabled via @option
{mlock
=on
}
2938 (enabled by
default).
2941 DEF("gdb", HAS_ARG
, QEMU_OPTION_gdb
, \
2942 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL
)
2944 @item
-gdb @
var{dev
}
2946 Wait
for gdb connection on device @
var{dev
} (@pxref
{gdb_usage
}). Typical
2947 connections will likely be TCP
-based
, but also UDP
, pseudo TTY
, or even
2948 stdio are reasonable use
case. The latter is allowing to start QEMU from
2949 within gdb and establish the connection via a pipe
:
2951 (gdb
) target remote | exec qemu
-system
-i386
-gdb stdio
...
2955 DEF("s", 0, QEMU_OPTION_s
, \
2956 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT
"\n",
2961 Shorthand
for -gdb tcp
::1234, i
.e
. open a gdbserver on TCP port
1234
2962 (@pxref
{gdb_usage
}).
2965 DEF("d", HAS_ARG
, QEMU_OPTION_d
, \
2966 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
2969 @item
-d @
var{item1
}[,...]
2971 Enable logging of specified items
. Use
'-d help' for a list of log items
.
2974 DEF("D", HAS_ARG
, QEMU_OPTION_D
, \
2975 "-D logfile output log to logfile (default stderr)\n",
2978 @item
-D @
var{logfile
}
2980 Output log
in @
var{logfile
} instead of to stderr
2983 DEF("L", HAS_ARG
, QEMU_OPTION_L
, \
2984 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2989 Set the directory
for the BIOS
, VGA BIOS and keymaps
.
2992 DEF("bios", HAS_ARG
, QEMU_OPTION_bios
, \
2993 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL
)
2995 @item
-bios @
var{file
}
2997 Set the filename
for the BIOS
.
3000 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm
, \
3001 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL
)
3005 Enable KVM full virtualization support
. This option is only available
3006 if KVM support is enabled when compiling
.
3009 DEF("xen-domid", HAS_ARG
, QEMU_OPTION_xen_domid
,
3010 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL
)
3011 DEF("xen-create", 0, QEMU_OPTION_xen_create
,
3012 "-xen-create create domain using xen hypercalls, bypassing xend\n"
3013 " warning: should not be used when xend is in use\n",
3015 DEF("xen-attach", 0, QEMU_OPTION_xen_attach
,
3016 "-xen-attach attach to existing xen domain\n"
3017 " xend will use this when starting QEMU\n",
3020 @item
-xen
-domid @
var{id
}
3022 Specify xen guest domain @
var{id
} (XEN only
).
3025 Create domain
using xen hypercalls
, bypassing xend
.
3026 Warning
: should not be used when xend is
in use (XEN only
).
3029 Attach to existing xen domain
.
3030 xend will use
this when starting
QEMU (XEN only
).
3033 DEF("no-reboot", 0, QEMU_OPTION_no_reboot
, \
3034 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL
)
3038 Exit instead of rebooting
.
3041 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown
, \
3042 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL
)
3045 @findex
-no
-shutdown
3046 Don
't exit QEMU on guest shutdown, but instead only stop the emulation.
3047 This allows for instance switching to monitor to commit changes to the
3051 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3052 "-loadvm [tag|id]\n" \
3053 " start right away with a saved state (loadvm in monitor)\n",
3056 @item -loadvm @var{file}
3058 Start right away with a saved state (@code{loadvm} in monitor)
3062 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3063 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3068 Daemonize the QEMU process after initialization. QEMU will not detach from
3069 standard IO until it is ready to receive connections on any of its devices.
3070 This option is a useful way for external programs to launch QEMU without having
3071 to cope with initialization race conditions.
3074 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3075 "-option-rom rom load a file, rom, into the option ROM space\n",
3078 @item -option-rom @var{file}
3080 Load the contents of @var{file} as an option ROM.
3081 This option is useful to load things like EtherBoot.
3084 HXCOMM Silently ignored for compatibility
3085 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3087 HXCOMM Options deprecated by -rtc
3088 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3089 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3091 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3092 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3093 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3098 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3100 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3101 UTC or local time, respectively. @code{localtime} is required for correct date in
3102 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3103 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3105 By default the RTC is driven by the host system time. This allows using of the
3106 RTC as accurate reference clock inside the guest, specifically if the host
3107 time is smoothly following an accurate external reference clock, e.g. via NTP.
3108 If you want to isolate the guest time from the host, you can set @option{clock}
3109 to @code{rt} instead. To even prevent it from progressing during suspension,
3110 you can set it to @code{vm}.
3112 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3113 specifically with Windows' ACPI HAL
. This option will
try to figure out how
3114 many timer interrupts were not processed by the Windows guest and will
3118 DEF("icount", HAS_ARG
, QEMU_OPTION_icount
, \
3119 "-icount [shift=N|auto][,align=on|off][,sleep=no]\n" \
3120 " enable virtual instruction counter with 2^N clock ticks per\n" \
3121 " instruction, enable aligning the host and virtual clocks\n" \
3122 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL
)
3124 @item
-icount
[shift
=@
var{N
}|auto
]
3126 Enable virtual instruction counter
. The virtual cpu will execute one
3127 instruction every
2^@
var{N
} ns of virtual time
. If @code
{auto
} is specified
3128 then the virtual cpu speed will be automatically adjusted to keep virtual
3129 time within a few seconds of real time
.
3131 When the virtual cpu is sleeping
, the virtual time will advance at
default
3132 speed unless @option
{sleep
=no
} is specified
.
3133 With @option
{sleep
=no
}, the virtual time will jump to the next timer deadline
3134 instantly whenever the virtual cpu goes to sleep mode and will not advance
3135 if no timer is enabled
. This behavior give deterministic execution times from
3136 the guest point of view
.
3138 Note that
while this option can give deterministic behavior
, it does not
3139 provide cycle accurate emulation
. Modern CPUs contain superscalar out of
3140 order cores with complex cache hierarchies
. The number of instructions
3141 executed often has little or no correlation with actual performance
.
3143 @option
{align
=on
} will activate the delay algorithm which will
try to
3144 to synchronise the host clock and the virtual clock
. The goal is to
3145 have a guest running at the real frequency imposed by the shift option
.
3146 Whenever the guest clock is behind the host clock and
if
3147 @option
{align
=on
} is specified then we print a message to the user
3148 to inform about the delay
.
3149 Currently
this option does not work when @option
{shift
} is @code
{auto
}.
3150 Note
: The sync algorithm will work
for those shift values
for which
3151 the guest clock runs ahead of the host clock
. Typically
this happens
3152 when the shift value is
high (how high depends on the host machine
).
3155 DEF("watchdog", HAS_ARG
, QEMU_OPTION_watchdog
, \
3156 "-watchdog model\n" \
3157 " enable virtual hardware watchdog [default=none]\n",
3160 @item
-watchdog @
var{model
}
3162 Create a virtual hardware watchdog device
. Once
enabled (by a guest
3163 action
), the watchdog must be periodically polled by an agent inside
3164 the guest or
else the guest will be restarted
. Choose a model
for
3165 which your guest has drivers
.
3167 The @
var{model
} is the model of hardware watchdog to emulate
. Use
3168 @code
{-watchdog help
} to list available hardware models
. Only one
3169 watchdog can be enabled
for a guest
.
3171 The following models may be available
:
3174 iBASE
700 is a very simple ISA watchdog with a single timer
.
3176 Intel
6300ESB I
/O controller hub is a much more featureful PCI
-based
3177 dual
-timer watchdog
.
3179 A virtual watchdog
for s390x backed by the diagnose
288 hypercall
3180 (currently KVM only
).
3184 DEF("watchdog-action", HAS_ARG
, QEMU_OPTION_watchdog_action
, \
3185 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3186 " action when watchdog fires [default=reset]\n",
3189 @item
-watchdog
-action @
var{action
}
3190 @findex
-watchdog
-action
3192 The @
var{action
} controls what QEMU will
do when the watchdog timer
3195 @code
{reset
} (forcefully reset the guest
).
3196 Other possible actions are
:
3197 @code
{shutdown
} (attempt to gracefully shutdown the guest
),
3198 @code
{poweroff
} (forcefully poweroff the guest
),
3199 @code
{pause
} (pause the guest
),
3200 @code
{debug
} (print a debug message and
continue), or
3201 @code
{none
} (do nothing
).
3203 Note that the @code
{shutdown
} action requires that the guest responds
3204 to ACPI signals
, which it may not be able to
do in the sort of
3205 situations where the watchdog would have expired
, and thus
3206 @code
{-watchdog
-action shutdown
} is not recommended
for production use
.
3211 @item
-watchdog i6300esb
-watchdog
-action pause
3212 @item
-watchdog ib700
3216 DEF("echr", HAS_ARG
, QEMU_OPTION_echr
, \
3217 "-echr chr set terminal escape character instead of ctrl-a\n",
3221 @item
-echr @
var{numeric_ascii_value
}
3223 Change the escape character used
for switching to the monitor when
using
3224 monitor and serial sharing
. The
default is @code
{0x01} when
using the
3225 @code
{-nographic
} option
. @code
{0x01} is equal to pressing
3226 @code
{Control
-a
}. You can select a different character from the ascii
3227 control keys where
1 through
26 map to Control
-a through Control
-z
. For
3228 instance you could use the either of the following to change the escape
3229 character to Control
-t
.
3236 DEF("virtioconsole", HAS_ARG
, QEMU_OPTION_virtiocon
, \
3237 "-virtioconsole c\n" \
3238 " set virtio console\n", QEMU_ARCH_ALL
)
3240 @item
-virtioconsole @
var{c
}
3241 @findex
-virtioconsole
3244 This option is maintained
for backward compatibility
.
3246 Please use @code
{-device virtconsole
} for the
new way of invocation
.
3249 DEF("show-cursor", 0, QEMU_OPTION_show_cursor
, \
3250 "-show-cursor show cursor\n", QEMU_ARCH_ALL
)
3253 @findex
-show
-cursor
3257 DEF("tb-size", HAS_ARG
, QEMU_OPTION_tb_size
, \
3258 "-tb-size n set TB size\n", QEMU_ARCH_ALL
)
3260 @item
-tb
-size @
var{n
}
3265 DEF("incoming", HAS_ARG
, QEMU_OPTION_incoming
, \
3266 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3267 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3268 "-incoming unix:socketpath\n" \
3269 " prepare for incoming migration, listen on\n" \
3270 " specified protocol and socket address\n" \
3271 "-incoming fd:fd\n" \
3272 "-incoming exec:cmdline\n" \
3273 " accept incoming migration on given file descriptor\n" \
3274 " or from given external command\n" \
3275 "-incoming defer\n" \
3276 " wait for the URI to be specified via migrate_incoming\n",
3279 @item
-incoming tcp
:[@
var{host
}]:@
var{port
}[,to
=@
var{maxport
}][,ipv4
][,ipv6
]
3280 @item
-incoming rdma
:@
var{host
}:@
var{port
}[,ipv4
][,ipv6
]
3282 Prepare
for incoming migration
, listen on a given tcp port
.
3284 @item
-incoming unix
:@
var{socketpath
}
3285 Prepare
for incoming migration
, listen on a given unix socket
.
3287 @item
-incoming fd
:@
var{fd
}
3288 Accept incoming migration from a given filedescriptor
.
3290 @item
-incoming exec
:@
var{cmdline
}
3291 Accept incoming migration as an output from specified external command
.
3293 @item
-incoming defer
3294 Wait
for the URI to be specified via migrate_incoming
. The monitor can
3295 be used to change
settings (such as migration parameters
) prior to issuing
3296 the migrate_incoming to allow the migration to begin
.
3299 DEF("nodefaults", 0, QEMU_OPTION_nodefaults
, \
3300 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL
)
3304 Don
't create default devices. Normally, QEMU sets the default devices like serial
3305 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3306 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3311 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3312 "-chroot dir chroot to dir just before starting the VM\n",
3316 @item -chroot @var{dir}
3318 Immediately before starting guest execution, chroot to the specified
3319 directory. Especially useful in combination with -runas.
3323 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3324 "-runas user change to user id user just before starting the VM\n",
3328 @item -runas @var{user}
3330 Immediately before starting guest execution, drop root privileges, switching
3331 to the specified user.
3334 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3335 "-prom-env variable=value\n"
3336 " set OpenBIOS nvram variables\n",
3337 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3339 @item -prom-env @var{variable}=@var{value}
3341 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3343 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3344 "-semihosting semihosting mode\n",
3345 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32)
3348 @findex -semihosting
3349 Enable semihosting mode (ARM, M68K, Xtensa only).
3351 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3352 "-semihosting-config [enable=on|off,]target=native|gdb|auto semihosting configuration\n",
3353 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32)
3355 @item -semihosting-config [enable=on|off,]target=native|gdb|auto
3356 @findex -semihosting-config
3357 Enable semihosting and define where the semihosting calls will be addressed,
3358 to QEMU (@code{native}) or to GDB (@code{gdb}). The default is @code{auto}, which means
3359 @code{gdb} during debug sessions and @code{native} otherwise (ARM, M68K, Xtensa only).
3361 DEF("old-param", 0, QEMU_OPTION_old_param,
3362 "-old-param old param mode\n", QEMU_ARCH_ARM)
3365 @findex -old-param (ARM)
3366 Old param mode (ARM only).
3369 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3370 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off
').\n",
3373 @item -sandbox @var{arg}
3375 Enable Seccomp mode 2 system call filter. 'on
' will enable syscall filtering and 'off
' will
3376 disable it. The default is 'off
'.
3379 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3380 "-readconfig <file>\n", QEMU_ARCH_ALL)
3382 @item -readconfig @var{file}
3384 Read device configuration from @var{file}. This approach is useful when you want to spawn
3385 QEMU process with many command line options but you don't want to exceed the command line
3388 DEF("writeconfig", HAS_ARG
, QEMU_OPTION_writeconfig
,
3389 "-writeconfig <file>\n"
3390 " read/write config file\n", QEMU_ARCH_ALL
)
3392 @item
-writeconfig @
var{file
}
3393 @findex
-writeconfig
3394 Write device configuration to @
var{file
}. The @
var{file
} can be either filename to save
3395 command line and device configuration into file or dash @code
{-}) character to print the
3396 output to stdout
. This can be later used as input file
for @code
{-readconfig
} option
.
3398 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig
,
3400 " do not load default config files at startup\n",
3404 @findex
-nodefconfig
3405 Normally QEMU loads configuration files from @
var{sysconfdir
} and @
var{datadir
} at startup
.
3406 The @code
{-nodefconfig
} option will prevent QEMU from loading any of those config files
.
3408 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig
,
3410 " do not load user-provided config files at startup\n",
3413 @item
-no
-user
-config
3414 @findex
-no
-user
-config
3415 The @code
{-no
-user
-config
} option makes QEMU not load any of the user
-provided
3416 config files on @
var{sysconfdir
}, but won
't make it skip the QEMU-provided config
3417 files from @var{datadir}.
3419 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3420 "-trace [events=<file>][,file=<file>]\n"
3421 " specify tracing options\n",
3424 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3425 HXCOMM HX does not support conditional compilation of text.
3426 @item -trace [events=@var{file}][,file=@var{file}]
3429 Specify tracing options.
3432 @item events=@var{file}
3433 Immediately enable events listed in @var{file}.
3434 The file must contain one event name (as listed in the @var{trace-events} file)
3436 This option is only available if QEMU has been compiled with
3437 either @var{simple} or @var{stderr} tracing backend.
3438 @item file=@var{file}
3439 Log output traces to @var{file}.
3441 This option is only available if QEMU has been compiled with
3442 the @var{simple} tracing backend.
3447 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3448 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3451 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3452 "-enable-fips enable FIPS 140-2 compliance\n",
3457 @findex -enable-fips
3458 Enable FIPS 140-2 compliance mode.
3461 HXCOMM Deprecated by -machine accel=tcg property
3462 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3464 HXCOMM Deprecated by kvm-pit driver properties
3465 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3468 HXCOMM Deprecated (ignored)
3469 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
3471 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3472 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3474 HXCOMM Deprecated (ignored)
3475 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3477 DEF("object", HAS_ARG, QEMU_OPTION_object,
3478 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3479 " create an new object of type TYPENAME setting properties\n"
3480 " in the order they are specified. Note that the 'id
'\n"
3481 " property must be set. These objects are placed in the\n"
3482 " '/objects
' path.\n",
3485 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3487 Create an new object of type @var{typename} setting properties
3488 in the order they are specified. Note that the 'id
'
3489 property must be set. These objects are placed in the
3493 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3494 "-msg timestamp[=on|off]\n"
3495 " change the format of messages\n"
3496 " on|off controls leading timestamps (default:on)\n",
3499 @item -msg timestamp[=on|off]
3501 prepend a timestamp to each log message.(default:on)
3504 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3505 "-dump-vmstate <file>\n"
3506 " Output vmstate information in JSON format to file.\n"
3507 " Use the scripts/vmstate-static-checker.py file to\n"
3508 " check for possible regressions in migration code\n"
3509 " by comparing two such vmstate dumps.",
3512 @item -dump-vmstate @var{file}
3513 @findex -dump-vmstate
3514 Dump json-encoded vmstate information for current machine type to file
3518 HXCOMM This is the last statement. Insert new options before this line!