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 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n"
37 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
38 " kvm_shadow_mem=size of KVM shadow MMU\n"
39 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
40 " mem-merge=on|off controls memory merge support (default: on)\n"
41 " iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n"
42 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
43 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
44 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
45 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n",
48 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
50 Select the emulated machine by @
var{name
}. Use @code
{-machine help
} to list
51 available machines
. Supported machine properties are
:
53 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
54 This is used to enable an accelerator
. Depending on the target architecture
,
55 kvm
, xen
, or tcg can be available
. By
default, tcg is used
. If there is more
56 than one accelerator specified
, the next one is used
if the previous one fails
58 @item kernel_irqchip
=on|off
59 Controls
in-kernel irqchip support
for the chosen accelerator when available
.
60 @item gfx_passthru
=on|off
61 Enables IGD GFX passthrough support
for the chosen machine when available
.
62 @item vmport
=on|off|auto
63 Enables emulation of VMWare IO port
, for vmmouse etc
. auto says to select the
64 value based on accel
. For accel
=xen the
default is off otherwise the
default
66 @item kvm_shadow_mem
=size
67 Defines the size of the KVM shadow MMU
.
68 @item dump
-guest
-core
=on|off
69 Include guest memory
in a core dump
. The
default is on
.
70 @item mem
-merge
=on|off
71 Enables or disables memory merge support
. This feature
, when supported by
72 the host
, de
-duplicates identical memory pages among VMs instances
75 Enables or disables emulated Intel
IOMMU (VT
-d
) support
. The
default is off
.
76 @item aes
-key
-wrap
=on|off
77 Enables or disables AES key wrapping support on s390
-ccw hosts
. This feature
78 controls whether AES wrapping keys will be created to allow
79 execution of AES cryptographic functions
. The
default is on
.
80 @item dea
-key
-wrap
=on|off
81 Enables or disables DEA key wrapping support on s390
-ccw hosts
. This feature
82 controls whether DEA wrapping keys will be created to allow
83 execution of DEA cryptographic functions
. The
default is on
.
87 HXCOMM Deprecated by
-machine
88 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
90 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
91 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
93 @item
-cpu @
var{model
}
95 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
98 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
99 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
100 " set the number of CPUs to 'n' [default=1]\n"
101 " maxcpus= maximum number of total cpus, including\n"
102 " offline CPUs for hotplug, etc\n"
103 " cores= number of CPU cores on one socket\n"
104 " threads= number of threads on one CPU core\n"
105 " sockets= number of discrete sockets in the system\n",
108 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
110 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
111 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
113 For the PC target
, the number of @
var{cores
} per socket
, the number
114 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
115 specified
. Missing values will be computed
. If any on the three values is
116 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
117 specifies the maximum number of hotpluggable CPUs
.
120 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
121 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n"
122 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL
)
124 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
125 @itemx
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
127 Simulate a multi node NUMA system
. If @samp
{mem
}, @samp
{memdev
}
128 and @samp
{cpus
} are omitted
, resources are split equally
. Also
, note
129 that the
-@option
{numa
} option doesn
't allocate any of the specified
130 resources. That is, it just assigns existing resources to NUMA nodes. This
131 means that one still has to use the @option{-m}, @option{-smp} options
132 to allocate RAM and VCPUs respectively, and possibly @option{-object}
133 to specify the memory backend for the @samp{memdev} suboption.
135 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
136 node uses @samp{memdev}, all of them have to use it.
139 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
140 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
141 " Add 'fd
' to fd 'set
'\n", QEMU_ARCH_ALL)
143 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
146 Add a file descriptor to an fd set. Valid options are:
150 This option defines the file descriptor of which a duplicate is added to fd set.
151 The file descriptor cannot be stdin, stdout, or stderr.
153 This option defines the ID of the fd set to add the file descriptor to.
154 @item opaque=@var{opaque}
155 This option defines a free-form string that can be used to describe @var{fd}.
158 You can open an image using pre-opened file descriptors from an fd set:
161 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
162 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
163 -drive file=/dev/fdset/2,index=0,media=disk
167 DEF("set", HAS_ARG, QEMU_OPTION_set,
168 "-set group.id.arg=value\n"
169 " set <arg> parameter for item <id> of type <group>\n"
170 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
172 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
174 Set parameter @var{arg} for item @var{id} of type @var{group}\n"
177 DEF("global", HAS_ARG, QEMU_OPTION_global,
178 "-global driver.property=value\n"
179 "-global driver=driver,property=property,value=value\n"
180 " set a global default for a driver property\n",
183 @item -global @var{driver}.@var{prop}=@var{value}
184 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
186 Set default value of @var{driver}'s property @
var{prop
} to @
var{value
}, e
.g
.:
189 qemu
-system
-i386
-global ide
-drive
.physical_block_size
=4096 -drive file
=file
,if=ide
,index
=0,media
=disk
192 In particular
, you can use
this to set driver properties
for devices which are
193 created automatically by the machine model
. To create a device which is not
194 created automatically and set properties on it
, use
-@option
{device
}.
196 -global @
var{driver
}.@
var{prop
}=@
var{value
} is shorthand
for -global
197 driver
=@
var{driver
},property
=@
var{prop
},value
=@
var{value
}. The
198 longhand syntax works even when @
var{driver
} contains a dot
.
201 DEF("boot", HAS_ARG
, QEMU_OPTION_boot
,
202 "-boot [order=drives][,once=drives][,menu=on|off]\n"
203 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
204 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
205 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
206 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
207 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
210 @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
]
212 Specify boot order @
var{drives
} as a string of drive letters
. Valid
213 drive letters depend on the target architecture
. The x86 PC uses
: a
, b
214 (floppy
1 and
2), c (first hard disk
), d (first CD
-ROM
), n
-p (Etherboot
215 from network adapter
1-4), hard disk boot is the
default. To apply a
216 particular boot order only on the first startup
, specify it via
219 Interactive boot menus
/prompts can be enabled via @option
{menu
=on
} as far
220 as firmware
/BIOS supports them
. The
default is non
-interactive boot
.
222 A splash picture could be passed to bios
, enabling user to show it as logo
,
223 when option splash
=@
var{sp_name
} is given and menu
=on
, If firmware
/BIOS
224 supports them
. Currently Seabios
for X86 system support it
.
225 limitation
: The splash file could be a jpeg file or a BMP file
in 24 BPP
226 format(true color
). The resolution should be supported by the SVGA mode
, so
227 the recommended is
320x240
, 640x480
, 800x640
.
229 A timeout could be passed to bios
, guest will pause
for @
var{rb_timeout
} ms
230 when boot failed
, then reboot
. If @
var{rb_timeout
} is
'-1', guest will not
231 reboot
, qemu passes
'-1' to bios by
default. Currently Seabios
for X86
234 Do strict boot via @option
{strict
=on
} as far as firmware
/BIOS
235 supports it
. This only effects when boot priority is changed by
236 bootindex options
. The
default is non
-strict boot
.
239 #
try to boot from network first
, then from hard disk
240 qemu
-system
-i386
-boot order
=nc
241 # boot from CD
-ROM first
, switch back to
default order after reboot
242 qemu
-system
-i386
-boot once
=d
243 # boot with a splash picture
for 5 seconds
.
244 qemu
-system
-i386
-boot menu
=on
,splash
=/root
/boot
.bmp
,splash
-time
=5000
247 Note
: The legacy format
'-boot @var{drives}' is still supported but its
248 use is discouraged as it may be removed from future versions
.
251 DEF("m", HAS_ARG
, QEMU_OPTION_m
,
252 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
253 " configure guest RAM\n"
254 " size: initial amount of guest memory\n"
255 " slots: number of hotplug slots (default: none)\n"
256 " maxmem: maximum amount of guest memory (default: none)\n"
257 "NOTE: Some architectures might enforce a specific granularity\n",
260 @item
-m
[size
=]@
var{megs
}[,slots
=n
,maxmem
=size
]
262 Sets guest startup RAM size to @
var{megs
} megabytes
. Default is
128 MiB
.
263 Optionally
, a suffix of ``M
'' or ``G
'' can be used to signify a value
in
264 megabytes or gigabytes respectively
. Optional pair @
var{slots
}, @
var{maxmem
}
265 could be used to set amount of hotpluggable memory slots and maximum amount of
266 memory
. Note that @
var{maxmem
} must be aligned to the page size
.
268 For example
, the following command
-line sets the guest startup RAM size to
269 1GB
, creates
3 slots to hotplug additional memory and sets the maximum
270 memory the guest can reach to
4GB
:
273 qemu
-system
-x86_64
-m
1G
,slots
=3,maxmem
=4G
276 If @
var{slots
} and @
var{maxmem
} are not specified
, memory hotplug won
't
277 be enabled and the guest startup RAM will never increase.
280 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
281 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
283 @item -mem-path @var{path}
285 Allocate guest RAM from a temporarily created file in @var{path}.
288 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
289 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
293 @findex -mem-prealloc
294 Preallocate memory when using -mem-path.
297 DEF("k", HAS_ARG, QEMU_OPTION_k,
298 "-k language use keyboard layout (for example 'fr
' for French)\n",
301 @item -k @var{language}
303 Use keyboard layout @var{language} (for example @code{fr} for
304 French). This option is only needed where it is not easy to get raw PC
305 keycodes (e.g. on Macs, with some X11 servers or with a VNC
306 display). You don't normally need to use it on PC
/Linux or PC
/Windows
309 The available layouts are
:
311 ar de
-ch es fo fr
-ca hu ja mk no pt
-br sv
312 da en
-gb et fr fr
-ch is lt nl pl ru th
313 de en
-us fi fr
-be hr it lv nl
-be pt sl tr
316 The
default is @code
{en
-us
}.
320 DEF("audio-help", 0, QEMU_OPTION_audio_help
,
321 "-audio-help print list of audio drivers and their options\n",
326 Will show the audio subsystem help
: list of drivers
, tunable
330 DEF("soundhw", HAS_ARG
, QEMU_OPTION_soundhw
,
331 "-soundhw c1,... enable audio support\n"
332 " and only specified sound cards (comma separated list)\n"
333 " use '-soundhw help' to get the list of supported cards\n"
334 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL
)
336 @item
-soundhw @
var{card1
}[,@
var{card2
},...] or
-soundhw all
338 Enable audio and selected sound hardware
. Use
'help' to print all
339 available sound hardware
.
342 qemu
-system
-i386
-soundhw sb16
,adlib disk
.img
343 qemu
-system
-i386
-soundhw es1370 disk
.img
344 qemu
-system
-i386
-soundhw ac97 disk
.img
345 qemu
-system
-i386
-soundhw hda disk
.img
346 qemu
-system
-i386
-soundhw all disk
.img
347 qemu
-system
-i386
-soundhw help
350 Note that Linux
's i810_audio OSS kernel (for AC97) module might
351 require manually specifying clocking.
354 modprobe i810_audio clocking=48000
358 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
359 "-balloon none disable balloon device\n"
360 "-balloon virtio[,addr=str]\n"
361 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
365 Disable balloon device.
366 @item -balloon virtio[,addr=@var{addr}]
367 Enable virtio balloon device (default), optionally with PCI address
371 DEF("device", HAS_ARG, QEMU_OPTION_device,
372 "-device driver[,prop[=value][,...]]\n"
373 " add device (based on driver)\n"
374 " prop=value,... sets driver properties\n"
375 " use '-device help
' to print all possible drivers\n"
376 " use '-device driver
,help
' to print all possible properties\n",
379 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
381 Add device @var{driver}. @var{prop}=@var{value} sets driver
382 properties. Valid properties depend on the driver. To get help on
383 possible drivers and properties, use @code{-device help} and
384 @code{-device @var{driver},help}.
387 DEF("name", HAS_ARG, QEMU_OPTION_name,
388 "-name string1[,process=string2][,debug-threads=on|off]\n"
389 " set the name of the guest\n"
390 " string1 sets the window title and string2 the process name (on Linux)\n"
391 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
392 " NOTE: The thread names are for debugging and not a stable API.\n",
395 @item -name @var{name}
397 Sets the @var{name} of the guest.
398 This name will be displayed in the SDL window caption.
399 The @var{name} will also be used for the VNC server.
400 Also optionally set the top visible process name in Linux.
401 Naming of individual threads can also be enabled on Linux to aid debugging.
404 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
405 "-uuid %08x-%04x-%04x-%04x-%012x\n"
406 " specify machine UUID\n", QEMU_ARCH_ALL)
408 @item -uuid @var{uuid}
418 DEFHEADING(Block device options:)
423 DEF("fda", HAS_ARG, QEMU_OPTION_fda,
424 "-fda/-fdb file use 'file
' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
425 DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
427 @item -fda @var{file}
428 @itemx -fdb @var{file}
431 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
434 DEF("hda", HAS_ARG, QEMU_OPTION_hda,
435 "-hda/-hdb file use 'file
' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
436 DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
437 DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
438 "-hdc/-hdd file use 'file
' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
439 DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
441 @item -hda @var{file}
442 @itemx -hdb @var{file}
443 @itemx -hdc @var{file}
444 @itemx -hdd @var{file}
449 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
452 DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
453 "-cdrom file use 'file
' as IDE cdrom image (cdrom is ide1 master)\n",
456 @item -cdrom @var{file}
458 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
459 @option{-cdrom} at the same time). You can use the host CD-ROM by
460 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
463 DEF("drive", HAS_ARG, QEMU_OPTION_drive,
464 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
465 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
466 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
467 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
468 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
469 " [,readonly=on|off][,copy-on-read=on|off]\n"
470 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
471 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
472 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
473 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
474 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
475 " [[,iops_size=is]]\n"
477 " use 'file
' as a drive image\n", QEMU_ARCH_ALL)
479 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
482 Define a new drive. Valid options are:
485 @item file=@var{file}
486 This option defines which disk image (@pxref{disk_images}) to use with
487 this drive. If the filename contains comma, you must double it
488 (for instance, "file=my,,file" to use file "my,file").
490 Special files such as iSCSI devices can be specified using protocol
491 specific URLs. See the section for "Device URL Syntax" for more information.
492 @item if=@var{interface}
493 This option defines on which type on interface the drive is connected.
494 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio.
495 @item bus=@var{bus},unit=@var{unit}
496 These options define where is connected the drive by defining the bus number and
498 @item index=@var{index}
499 This option defines where is connected the drive by using an index in the list
500 of available connectors of a given interface type.
501 @item media=@var{media}
502 This option defines the type of the media: disk or cdrom.
503 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
504 These options have the same definition as they have in @option{-hdachs}.
505 @item snapshot=@var{snapshot}
506 @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
507 (see @option{-snapshot}).
508 @item cache=@var{cache}
509 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
511 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
512 @item discard=@var{discard}
513 @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.
514 @item format=@var{format}
515 Specify which disk @var{format} will be used rather than detecting
516 the format. Can be used to specifiy format=raw to avoid interpreting
517 an untrusted format header.
518 @item serial=@var{serial}
519 This option specifies the serial number to assign to the device.
520 @item addr=@var{addr}
521 Specify the controller's PCI
address (if=virtio only
).
522 @item werror
=@
var{action
},rerror
=@
var{action
}
523 Specify which @
var{action
} to take on write and read errors
. Valid actions are
:
524 "ignore" (ignore the error and
try to
continue), "stop" (pause QEMU
),
525 "report" (report the error to the guest
), "enospc" (pause QEMU only
if the
526 host disk is full
; report the error to the guest otherwise
).
527 The
default setting is @option
{werror
=enospc
} and @option
{rerror
=report
}.
529 Open drive @option
{file
} as read
-only
. Guest write attempts will fail
.
530 @item copy
-on
-read
=@
var{copy
-on
-read
}
531 @
var{copy
-on
-read
} is
"on" or
"off" and enables whether to copy read backing
532 file sectors into the image file
.
533 @item detect
-zeroes
=@
var{detect
-zeroes
}
534 @
var{detect
-zeroes
} is
"off", "on" or
"unmap" and enables the automatic
535 conversion of plain zero writes by the OS to driver specific optimized
536 zero write commands
. You may even choose
"unmap" if @
var{discard
} is set
537 to
"unmap" to allow a zero write to be converted to an UNMAP operation
.
540 By
default, the @option
{cache
=writeback
} mode is used
. It will report data
541 writes as completed as soon as the data is present
in the host page cache
.
542 This is safe as long as your guest OS makes sure to correctly flush disk caches
543 where needed
. If your guest OS does not handle volatile disk write caches
544 correctly and your host crashes or loses power
, then the guest may experience
547 For such guests
, you should consider
using @option
{cache
=writethrough
}. This
548 means that the host page cache will be used to read and write data
, but write
549 notification will be sent to the guest only after QEMU has made sure to flush
550 each write to the disk
. Be aware that
this has a major impact on performance
.
552 The host page cache can be avoided entirely with @option
{cache
=none
}. This will
553 attempt to
do disk IO directly to the guest
's memory. QEMU may still perform
554 an internal copy of the data. Note that this is considered a writeback mode and
555 the guest OS must handle the disk write cache correctly in order to avoid data
556 corruption on host crashes.
558 The host page cache can be avoided while only sending write notifications to
559 the guest when the data has been flushed to the disk using
560 @option{cache=directsync}.
562 In case you don't care about data integrity over host failures
, use
563 @option
{cache
=unsafe
}. This option tells QEMU that it
never needs to write any
564 data to the disk but can instead keep things
in cache
. If anything goes wrong
,
565 like your host losing power
, the disk storage getting disconnected accidentally
,
566 etc
. your image will most probably be rendered unusable
. When
using
567 the @option
{-snapshot
} option
, unsafe caching is always used
.
569 Copy
-on
-read avoids accessing the same backing file sectors repeatedly and is
570 useful when the backing file is over a slow network
. By
default copy
-on
-read
573 Instead of @option
{-cdrom
} you can use
:
575 qemu
-system
-i386
-drive file
=file
,index
=2,media
=cdrom
578 Instead of @option
{-hda
}, @option
{-hdb
}, @option
{-hdc
}, @option
{-hdd
}, you can
581 qemu
-system
-i386
-drive file
=file
,index
=0,media
=disk
582 qemu
-system
-i386
-drive file
=file
,index
=1,media
=disk
583 qemu
-system
-i386
-drive file
=file
,index
=2,media
=disk
584 qemu
-system
-i386
-drive file
=file
,index
=3,media
=disk
587 You can open an image
using pre
-opened file descriptors from an fd set
:
590 -add
-fd fd
=3,set
=2,opaque
="rdwr:/path/to/file"
591 -add
-fd fd
=4,set
=2,opaque
="rdonly:/path/to/file"
592 -drive file
=/dev
/fdset
/2,index
=0,media
=disk
595 You can connect a CDROM to the slave of ide0
:
597 qemu
-system
-i386
-drive file
=file
,if=ide
,index
=1,media
=cdrom
600 If you don
't specify the "file=" argument, you define an empty drive:
602 qemu-system-i386 -drive if=ide,index=1,media=cdrom
605 You can connect a SCSI disk with unit ID 6 on the bus #0:
607 qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6
610 Instead of @option{-fda}, @option{-fdb}, you can use:
612 qemu-system-i386 -drive file=file,index=0,if=floppy
613 qemu-system-i386 -drive file=file,index=1,if=floppy
616 By default, @var{interface} is "ide" and @var{index} is automatically
619 qemu-system-i386 -drive file=a -drive file=b"
623 qemu-system-i386 -hda a -hdb b
627 DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
628 "-mtdblock file use 'file
' as on-board Flash memory image\n",
631 @item -mtdblock @var{file}
633 Use @var{file} as on-board Flash memory image.
636 DEF("sd", HAS_ARG, QEMU_OPTION_sd,
637 "-sd file use 'file
' as SecureDigital card image\n", QEMU_ARCH_ALL)
641 Use @var{file} as SecureDigital card image.
644 DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
645 "-pflash file use 'file
' as a parallel flash image\n", QEMU_ARCH_ALL)
647 @item -pflash @var{file}
649 Use @var{file} as a parallel flash image.
652 DEF("snapshot", 0, QEMU_OPTION_snapshot,
653 "-snapshot write to temporary files instead of disk image files\n",
658 Write to temporary files instead of disk image files. In this case,
659 the raw disk image you use is not written back. You can however force
660 the write back by pressing @key{C-a s} (@pxref{disk_images}).
663 DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
664 "-hdachs c,h,s[,t]\n" \
665 " force hard disk 0 physical geometry and the optional BIOS\n" \
666 " translation (t=none or lba) (usually QEMU can guess them)\n",
669 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
671 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
672 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
673 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
674 all those parameters. This option is useful for old MS-DOS disk
678 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
679 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
680 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
685 @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}]
687 Define a new file system device. Valid options are:
690 This option specifies the fs driver backend to use.
691 Currently "local", "handle" and "proxy" file system drivers are supported.
693 Specifies identifier for this device
694 @item path=@var{path}
695 Specifies the export path for the file system device. Files under
696 this path will be available to the 9p client on the guest.
697 @item security_model=@var{security_model}
698 Specifies the security model to be used for this export path.
699 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
700 In "passthrough" security model, files are stored using the same
701 credentials as they are created on the guest. This requires QEMU
702 to run as root. In "mapped-xattr" security model, some of the file
703 attributes like uid, gid, mode bits and link target are stored as
704 file attributes. For "mapped-file" these attributes are stored in the
705 hidden .virtfs_metadata directory. Directories exported by this security model cannot
706 interact with other unix tools. "none" security model is same as
707 passthrough except the sever won't report failures
if it fails to
708 set file attributes like ownership
. Security model is mandatory
709 only
for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take
710 security model as a parameter.
711 @item writeout=@var{writeout}
712 This is an optional argument. The only supported value is "immediate".
713 This means that host page cache will be used to read and write data but
714 write notification will be sent to the guest only when the data has been
715 reported as written by the storage subsystem.
717 Enables exporting 9p share as a readonly mount for guests. By default
718 read-write access is given.
719 @item socket=@var{socket}
720 Enables proxy filesystem driver to use passed socket file for communicating
721 with virtfs-proxy-helper
722 @item sock_fd=@var{sock_fd}
723 Enables proxy filesystem driver to use passed socket descriptor for
724 communicating with virtfs-proxy-helper. Usually a helper like libvirt
725 will create socketpair and pass one of the fds as sock_fd
728 -fsdev option is used along with -device driver "virtio-9p-pci".
729 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
730 Options for virtio-9p-pci driver are:
733 Specifies the id value specified along with -fsdev option
734 @item mount_tag=@var{mount_tag}
735 Specifies the tag name to be used by the guest to mount this export point
740 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
741 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
742 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
747 @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}]
750 The general form of a Virtual File system pass-through options are:
753 This option specifies the fs driver backend to use.
754 Currently "local", "handle" and "proxy" file system drivers are supported.
756 Specifies identifier for this device
757 @item path=@var{path}
758 Specifies the export path for the file system device. Files under
759 this path will be available to the 9p client on the guest.
760 @item security_model=@var{security_model}
761 Specifies the security model to be used for this export path.
762 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
763 In "passthrough" security model, files are stored using the same
764 credentials as they are created on the guest. This requires QEMU
765 to run as root. In "mapped-xattr" security model, some of the file
766 attributes like uid, gid, mode bits and link target are stored as
767 file attributes. For "mapped-file" these attributes are stored in the
768 hidden .virtfs_metadata directory. Directories exported by this security model cannot
769 interact with other unix tools. "none" security model is same as
770 passthrough except the sever won't report failures
if it fails to
771 set file attributes like ownership
. Security model is mandatory only
772 for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take security
773 model as a parameter.
774 @item writeout=@var{writeout}
775 This is an optional argument. The only supported value is "immediate".
776 This means that host page cache will be used to read and write data but
777 write notification will be sent to the guest only when the data has been
778 reported as written by the storage subsystem.
780 Enables exporting 9p share as a readonly mount for guests. By default
781 read-write access is given.
782 @item socket=@var{socket}
783 Enables proxy filesystem driver to use passed socket file for
784 communicating with virtfs-proxy-helper. Usually a helper like libvirt
785 will create socketpair and pass one of the fds as sock_fd
787 Enables proxy filesystem driver to use passed 'sock_fd
' as the socket
788 descriptor for interfacing with virtfs-proxy-helper
792 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
793 "-virtfs_synth Create synthetic file system image\n",
797 @findex -virtfs_synth
798 Create synthetic file system image
806 DEFHEADING(USB options:)
811 DEF("usb", 0, QEMU_OPTION_usb,
812 "-usb enable the USB driver (will be the default soon)\n",
817 Enable the USB driver (will be the default soon)
820 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
821 "-usbdevice name add the host or guest USB device 'name
'\n",
825 @item -usbdevice @var{devname}
827 Add the USB device @var{devname}. @xref{usb_devices}.
832 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
835 Pointer device that uses absolute coordinates (like a touchscreen). This
836 means QEMU is able to report the mouse position without having to grab the
837 mouse. Also overrides the PS/2 mouse emulation when activated.
839 @item disk:[format=@var{format}]:@var{file}
840 Mass storage device based on file. The optional @var{format} argument
841 will be used rather than detecting the format. Can be used to specifiy
842 @code{format=raw} to avoid interpreting an untrusted format header.
844 @item host:@var{bus}.@var{addr}
845 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
847 @item host:@var{vendor_id}:@var{product_id}
848 Pass through the host device identified by @var{vendor_id}:@var{product_id}
851 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
852 Serial converter to host character device @var{dev}, see @code{-serial} for the
856 Braille device. This will use BrlAPI to display the braille output on a real
859 @item net:@var{options}
860 Network adapter that supports CDC ethernet and RNDIS protocols.
870 DEFHEADING(Display options:)
875 DEF("display", HAS_ARG, QEMU_OPTION_display,
876 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
877 " [,window_close=on|off]|curses|none|\n"
878 " gtk[,grab_on_hover=on|off]|\n"
879 " vnc=<display>[,<optargs>]\n"
880 " select display type\n", QEMU_ARCH_ALL)
882 @item -display @var{type}
884 Select type of display to use. This option is a replacement for the
885 old style -sdl/-curses/... options. Valid values for @var{type} are
888 Display video output via SDL (usually in a separate graphics
889 window; see the SDL documentation for other possibilities).
891 Display video output via curses. For graphics device models which
892 support a text mode, QEMU can display this output using a
893 curses/ncurses interface. Nothing is displayed when the graphics
894 device is in graphical mode or if the graphics device does not support
895 a text mode. Generally only the VGA device models support text mode.
897 Do not display video output. The guest will still see an emulated
898 graphics card, but its output will not be displayed to the QEMU
899 user. This option differs from the -nographic option in that it
900 only affects what is done with video output; -nographic also changes
901 the destination of the serial and parallel port data.
903 Display video output in a GTK window. This interface provides drop-down
904 menus and other UI elements to configure and control the VM during
907 Start a VNC server on display <arg>
911 DEF("nographic", 0, QEMU_OPTION_nographic,
912 "-nographic disable graphical output and redirect serial I/Os to console\n",
917 Normally, QEMU uses SDL to display the VGA output. With this option,
918 you can totally disable graphical output so that QEMU is a simple
919 command line application. The emulated serial port is redirected on
920 the console and muxed with the monitor (unless redirected elsewhere
921 explicitly). Therefore, you can still use QEMU to debug a Linux kernel
922 with a serial console. Use @key{C-a h} for help on switching between
923 the console and monitor.
926 DEF("curses", 0, QEMU_OPTION_curses,
927 "-curses use a curses/ncurses interface instead of SDL\n",
932 Normally, QEMU uses SDL to display the VGA output. With this option,
933 QEMU can display the VGA output when in text mode using a
934 curses/ncurses interface. Nothing is displayed in graphical mode.
937 DEF("no-frame", 0, QEMU_OPTION_no_frame,
938 "-no-frame open SDL window without a frame and window decorations\n",
943 Do not use decorations for SDL windows and start them using the whole
944 available screen space. This makes the using QEMU in a dedicated desktop
945 workspace more convenient.
948 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
949 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
954 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
955 affects the special keys (for fullscreen, monitor-mode switching, etc).
958 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
959 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
964 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
965 affects the special keys (for fullscreen, monitor-mode switching, etc).
968 DEF("no-quit", 0, QEMU_OPTION_no_quit,
969 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
973 Disable SDL window close capability.
976 DEF("sdl", 0, QEMU_OPTION_sdl,
977 "-sdl enable SDL\n", QEMU_ARCH_ALL)
984 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
985 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
986 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
987 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
988 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
989 " [,tls-ciphers=<list>]\n"
990 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
991 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
992 " [,sasl][,password=<secret>][,disable-ticketing]\n"
993 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
994 " [,jpeg-wan-compression=[auto|never|always]]\n"
995 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
996 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
997 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
998 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1000 " at least one of {port, tls-port} is mandatory\n",
1003 @item -spice @var{option}[,@var{option}[,...]]
1005 Enable the spice remote desktop protocol. Valid options are
1010 Set the TCP port spice is listening on for plaintext channels.
1013 Set the IP address spice is listening on. Default is any address.
1018 Force using the specified IP version.
1020 @item password=<secret>
1021 Set the password you need to authenticate.
1024 Require that the client use SASL to authenticate with the spice.
1025 The exact choice of authentication method used is controlled from the
1026 system / user's SASL configuration file
for the
'qemu' service
. This
1027 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
1028 unprivileged user
, an environment variable SASL_CONF_PATH can be used
1029 to make it search alternate locations
for the service config
.
1030 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
1031 it is recommended that SASL always be combined with the
'tls' and
1032 'x509' settings to enable use of SSL and server certificates
. This
1033 ensures a data encryption preventing compromise of authentication
1036 @item disable
-ticketing
1037 Allow client connects without authentication
.
1039 @item disable
-copy
-paste
1040 Disable copy paste between the client and the guest
.
1042 @item disable
-agent
-file
-xfer
1043 Disable spice
-vdagent based file
-xfer between the client and the guest
.
1046 Set the TCP port spice is listening on
for encrypted channels
.
1048 @item x509
-dir
=<dir
>
1049 Set the x509 file directory
. Expects same filenames as
-vnc $display
,x509
=$dir
1051 @item x509
-key
-file
=<file
>
1052 @itemx x509
-key
-password
=<file
>
1053 @itemx x509
-cert
-file
=<file
>
1054 @itemx x509
-cacert
-file
=<file
>
1055 @itemx x509
-dh
-key
-file
=<file
>
1056 The x509 file names can also be configured individually
.
1058 @item tls
-ciphers
=<list
>
1059 Specify which ciphers to use
.
1061 @item tls
-channel
=[main|display|cursor|inputs|record|playback
]
1062 @itemx plaintext
-channel
=[main|display|cursor|inputs|record|playback
]
1063 Force specific channel to be used with or without TLS encryption
. The
1064 options can be specified multiple times to configure multiple
1065 channels
. The special name
"default" can be used to set the
default
1066 mode
. For channels which are not explicitly forced into one mode the
1067 spice client is allowed to pick tls
/plaintext as he pleases
.
1069 @item image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]
1070 Configure image
compression (lossless
).
1071 Default is auto_glz
.
1073 @item jpeg
-wan
-compression
=[auto|
never|always
]
1074 @itemx zlib
-glz
-wan
-compression
=[auto|
never|always
]
1075 Configure wan image
compression (lossy
for slow links
).
1078 @item streaming
-video
=[off|all|filter
]
1079 Configure video stream detection
. Default is filter
.
1081 @item agent
-mouse
=[on|off
]
1082 Enable
/disable passing mouse events via vdagent
. Default is on
.
1084 @item playback
-compression
=[on|off
]
1085 Enable
/disable audio stream
compression (using celt
0.5.1). Default is on
.
1087 @item seamless
-migration
=[on|off
]
1088 Enable
/disable spice seamless migration
. Default is off
.
1093 DEF("portrait", 0, QEMU_OPTION_portrait
,
1094 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1099 Rotate graphical output
90 deg
left (only PXA LCD
).
1102 DEF("rotate", HAS_ARG
, QEMU_OPTION_rotate
,
1103 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1106 @item
-rotate @
var{deg
}
1108 Rotate graphical output some deg
left (only PXA LCD
).
1111 DEF("vga", HAS_ARG
, QEMU_OPTION_vga
,
1112 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1113 " select video card type\n", QEMU_ARCH_ALL
)
1115 @item
-vga @
var{type
}
1117 Select type of VGA card to emulate
. Valid values
for @
var{type
} are
1120 Cirrus Logic GD5446 Video card
. All Windows versions starting from
1121 Windows
95 should recognize and use
this graphic card
. For optimal
1122 performances
, use
16 bit color depth
in the guest and the host OS
.
1123 (This one is the
default)
1125 Standard VGA card with Bochs VBE extensions
. If your guest OS
1126 supports the VESA
2.0 VBE
extensions (e
.g
. Windows XP
) and
if you want
1127 to use high resolution
modes (>= 1280x1024x16
) then you should use
1130 VMWare SVGA
-II compatible adapter
. Use it
if you have sufficiently
1131 recent XFree86
/XOrg server or Windows guest with a driver
for this
1134 QXL paravirtual graphic card
. It is VGA
compatible (including VESA
1135 2.0 VBE support
). Works best with qxl guest drivers installed though
.
1136 Recommended choice when
using the spice protocol
.
1138 (sun4m only
) Sun TCX framebuffer
. This is the
default framebuffer
for
1139 sun4m machines and offers both
8-bit and
24-bit colour depths at a
1140 fixed resolution of
1024x768
.
1142 (sun4m only
) Sun cgthree framebuffer
. This is a simple
8-bit framebuffer
1143 for sun4m machines available
in both
1024x768 (OpenBIOS
) and
1152x900 (OBP
)
1144 resolutions aimed at people wishing to run older Solaris versions
.
1152 DEF("full-screen", 0, QEMU_OPTION_full_screen
,
1153 "-full-screen start in full screen\n", QEMU_ARCH_ALL
)
1156 @findex
-full
-screen
1157 Start
in full screen
.
1160 DEF("g", 1, QEMU_OPTION_g
,
1161 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1162 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
1164 @item
-g @
var{width
}x@
var{height
}[x@
var{depth
}]
1166 Set the initial graphical resolution and
depth (PPC
, SPARC only
).
1169 DEF("vnc", HAS_ARG
, QEMU_OPTION_vnc
,
1170 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL
)
1172 @item
-vnc @
var{display
}[,@
var{option
}[,@
var{option
}[,...]]]
1174 Normally
, QEMU uses SDL to display the VGA output
. With
this option
,
1175 you can have QEMU listen on VNC display @
var{display
} and redirect the VGA
1176 display over the VNC session
. It is very useful to enable the usb
1177 tablet device when
using this option (option @option
{-usbdevice
1178 tablet
}). When
using the VNC display
, you must use the @option
{-k
}
1179 parameter to set the keyboard layout
if you are not
using en
-us
. Valid
1180 syntax
for the @
var{display
} is
1184 @item @
var{host
}:@
var{d
}
1186 TCP connections will only be allowed from @
var{host
} on display @
var{d
}.
1187 By convention the TCP port is
5900+@
var{d
}. Optionally
, @
var{host
} can
1188 be omitted
in which
case the server will accept connections from any host
.
1190 @item unix
:@
var{path
}
1192 Connections will be allowed over UNIX domain sockets where @
var{path
} is the
1193 location of a unix socket to listen
for connections on
.
1197 VNC is initialized but not started
. The monitor @code
{change
} command
1198 can be used to later start the VNC server
.
1202 Following the @
var{display
} value there may be one or more @
var{option
} flags
1203 separated by commas
. Valid options are
1209 Connect to a listening VNC client via a ``reverse
'' connection
. The
1210 client is specified by the @
var{display
}. For reverse network
1211 connections (@
var{host
}:@
var{d
},@code
{reverse
}), the @
var{d
} argument
1212 is a TCP port number
, not a display number
.
1216 Opens an additional TCP listening port dedicated to VNC Websocket connections
.
1217 By definition the Websocket port is
5700+@
var{display
}. If @
var{host
} is
1218 specified connections will only be allowed from
this host
.
1219 As an alternative the Websocket port could be specified by
using
1220 @code
{websocket
}=@
var{port
}.
1221 If no TLS credentials are provided
, the websocket connection runs
in
1222 unencrypted mode
. If TLS credentials are provided
, the websocket connection
1223 requires encrypted client connections
.
1227 Require that password based authentication is used
for client connections
.
1229 The password must be set separately
using the @code
{set_password
} command
in
1230 the @ref
{pcsys_monitor
}. The syntax to change your password is
:
1231 @code
{set_password
<protocol
> <password
>} where
<protocol
> could be either
1234 If you would like to change
<protocol
> password expiration
, you should use
1235 @code
{expire_password
<protocol
> <expiration
-time
>} where expiration time could
1236 be one of the following options
: now
, never, +seconds or UNIX time of
1237 expiration
, e
.g
. +60 to make password expire
in 60 seconds
, or
1335196800
1238 to make password expire on
"Mon Apr 23 12:00:00 EDT 2012" (UNIX time
for this
1241 You can also use keywords
"now" or
"never" for the expiration time to
1242 allow
<protocol
> password to expire immediately or
never expire
.
1244 @item tls
-creds
=@
var{ID
}
1246 Provides the ID of a set of TLS credentials to use to secure the
1247 VNC server
. They will apply to both the normal VNC server socket
1248 and the websocket
socket (if enabled
). Setting TLS credentials
1249 will cause the VNC server socket to enable the VeNCrypt auth
1250 mechanism
. The credentials should have been previously created
1251 using the @option
{-object tls
-creds
} argument
.
1253 The @option
{tls
-creds
} parameter obsoletes the @option
{tls
},
1254 @option
{x509
}, and @option
{x509verify
} options
, and as such
1255 it is not permitted to set both
new and old type options at
1260 Require that client use TLS when communicating with the VNC server
. This
1261 uses anonymous TLS credentials so is susceptible to a man
-in-the
-middle
1262 attack
. It is recommended that
this option be combined with either the
1263 @option
{x509
} or @option
{x509verify
} options
.
1265 This option is now deprecated
in favor of
using the @option
{tls
-creds
}
1268 @item x509
=@
var{/path
/to
/certificate
/dir
}
1270 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1271 for negotiating the TLS session
. The server will send its x509 certificate
1272 to the client
. It is recommended that a password be set on the VNC server
1273 to provide authentication of the client when
this is used
. The path following
1274 this option specifies where the x509 certificates are to be loaded from
.
1275 See the @ref
{vnc_security
} section
for details on generating certificates
.
1277 This option is now deprecated
in favour of
using the @option
{tls
-creds
}
1280 @item x509verify
=@
var{/path
/to
/certificate
/dir
}
1282 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1283 for negotiating the TLS session
. The server will send its x509 certificate
1284 to the client
, and request that the client send its own x509 certificate
.
1285 The server will validate the client
's certificate against the CA certificate,
1286 and reject clients when validation fails. If the certificate authority is
1287 trusted, this is a sufficient authentication mechanism. You may still wish
1288 to set a password on the VNC server as a second authentication layer. The
1289 path following this option specifies where the x509 certificates are to
1290 be loaded from. See the @ref{vnc_security} section for details on generating
1293 This option is now deprecated in favour of using the @option{tls-creds}
1298 Require that the client use SASL to authenticate with the VNC server.
1299 The exact choice of authentication method used is controlled from the
1300 system / user's SASL configuration file
for the
'qemu' service
. This
1301 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
1302 unprivileged user
, an environment variable SASL_CONF_PATH can be used
1303 to make it search alternate locations
for the service config
.
1304 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
1305 it is recommended that SASL always be combined with the
'tls' and
1306 'x509' settings to enable use of SSL and server certificates
. This
1307 ensures a data encryption preventing compromise of authentication
1308 credentials
. See the @ref
{vnc_security
} section
for details on
using
1309 SASL authentication
.
1313 Turn on access control lists
for checking of the x509 client certificate
1314 and SASL party
. For x509 certs
, the ACL check is made against the
1315 certificate
's distinguished name. This is something that looks like
1316 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1317 made against the username, which depending on the SASL plugin, may
1318 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1319 When the @option{acl} flag is set, the initial access list will be
1320 empty, with a @code{deny} policy. Thus no one will be allowed to
1321 use the VNC server until the ACLs have been loaded. This can be
1322 achieved using the @code{acl} monitor command.
1326 Enable lossy compression methods (gradient, JPEG, ...). If this
1327 option is set, VNC client may receive lossy framebuffer updates
1328 depending on its encoding settings. Enabling this option can save
1329 a lot of bandwidth at the expense of quality.
1333 Disable adaptive encodings. Adaptive encodings are enabled by default.
1334 An adaptive encoding will try to detect frequently updated screen regions,
1335 and send updates in these regions using a lossy encoding (like JPEG).
1336 This can be really helpful to save bandwidth when playing videos. Disabling
1337 adaptive encodings restores the original static behavior of encodings
1340 @item share=[allow-exclusive|force-shared|ignore]
1342 Set display sharing policy. 'allow
-exclusive
' allows clients to ask
1343 for exclusive access. As suggested by the rfb spec this is
1344 implemented by dropping other connections. Connecting multiple
1345 clients in parallel requires all clients asking for a shared session
1346 (vncviewer: -shared switch). This is the default. 'force
-shared
'
1347 disables exclusive client access. Useful for shared desktop sessions,
1348 where you don't want someone forgetting specify
-shared disconnect
1349 everybody
else. 'ignore' completely ignores the shared flag and
1350 allows everybody connect unconditionally
. Doesn
't conform to the rfb
1351 spec but is traditional QEMU behavior.
1359 ARCHHEADING(, QEMU_ARCH_I386)
1361 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1366 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1367 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1372 Use it when installing Windows 2000 to avoid a disk full bug. After
1373 Windows 2000 is installed, you no longer need this option (this option
1374 slows down the IDE transfers).
1377 HXCOMM Deprecated by -rtc
1378 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1380 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1381 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1384 @item -no-fd-bootchk
1385 @findex -no-fd-bootchk
1386 Disable boot signature checking for floppy disks in BIOS. May
1387 be needed to boot from old floppy disks.
1390 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1391 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1395 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1396 it if your guest OS complains about ACPI problems (PC target machine
1400 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1401 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1405 Disable HPET support.
1408 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1409 "-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"
1410 " ACPI table description\n", QEMU_ARCH_I386)
1412 @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}]...]
1414 Add ACPI table with specified header fields and context from specified files.
1415 For file=, take whole ACPI table from the specified files, including all
1416 ACPI headers (possible overridden by other options).
1417 For data=, only data
1418 portion of the table is used, all header information is specified in the
1422 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1423 "-smbios file=binary\n"
1424 " load SMBIOS entry from binary file\n"
1425 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1427 " specify SMBIOS type 0 fields\n"
1428 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1429 " [,uuid=uuid][,sku=str][,family=str]\n"
1430 " specify SMBIOS type 1 fields\n"
1431 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1432 " [,asset=str][,location=str]\n"
1433 " specify SMBIOS type 2 fields\n"
1434 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1436 " specify SMBIOS type 3 fields\n"
1437 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1438 " [,asset=str][,part=str]\n"
1439 " specify SMBIOS type 4 fields\n"
1440 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1441 " [,asset=str][,part=str][,speed=%d]\n"
1442 " specify SMBIOS type 17 fields\n",
1443 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1445 @item -smbios file=@var{binary}
1447 Load SMBIOS entry from binary file.
1449 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1450 Specify SMBIOS type 0 fields
1452 @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}]
1453 Specify SMBIOS type 1 fields
1455 @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}]
1456 Specify SMBIOS type 2 fields
1458 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1459 Specify SMBIOS type 3 fields
1461 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1462 Specify SMBIOS type 4 fields
1464 @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}]
1465 Specify SMBIOS type 17 fields
1473 DEFHEADING(Network options:)
1478 HXCOMM Legacy slirp options (now moved to -net user):
1480 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1481 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1482 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1484 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1488 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1490 "-netdev user,id=str[,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
1491 " [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n"
1492 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1494 "[,smb=dir[,smbserver=addr]]\n"
1496 " configure a user mode network backend with ID 'str
',\n"
1497 " its DHCP server and optional services\n"
1500 "-netdev tap,id=str,ifname=name\n"
1501 " configure a host TAP network backend with ID 'str
'\n"
1503 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1504 " [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1505 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1506 " configure a host TAP network backend with ID 'str
'\n"
1507 " use network scripts 'file
' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1508 " to configure it and 'dfile
' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1509 " to deconfigure it\n"
1510 " use '[down
]script
=no
' to disable script execution\n"
1511 " use network helper 'helper
' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1513 " use 'fd
=h
' to connect to an already opened TAP interface\n"
1514 " use 'fds
=x
:y
:...:z
' to connect to already opened multiqueue capable TAP interfaces\n"
1515 " use 'sndbuf
=nbytes
' to limit the size of the send buffer (the\n"
1516 " default is disabled 'sndbuf
=0' to enable flow control set 'sndbuf
=1048576')\n"
1517 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1518 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1519 " use vhost=on to enable experimental in kernel accelerator\n"
1520 " (only has effect for virtio guests which use MSIX)\n"
1521 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1522 " use 'vhostfd
=h
' to connect to an already opened vhost net device\n"
1523 " use 'vhostfds
=x
:y
:...:z to connect to multiple already opened vhost net devices
\n"
1524 " use
'queues=n' to specify the number of queues to be created
for multiqueue TAP
\n"
1525 "-netdev bridge
,id
=str
[,br
=bridge
][,helper
=helper
]\n"
1526 " configure a host TAP network backend with ID
'str' that is
\n"
1527 " connected to a
bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1528 " using the program
'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1531 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1532 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1533 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1534 " [,rxcookie=rxcookie][,offset=offset]\n"
1535 " configure a network backend with ID 'str
' connected to\n"
1536 " an Ethernet over L2TPv3 pseudowire.\n"
1537 " Linux kernel 3.3+ as well as most routers can talk\n"
1538 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1539 " VM to a router and even VM to Host. It is a nearly-universal\n"
1540 " standard (RFC3391). Note - this implementation uses static\n"
1541 " pre-configured tunnels (same as the Linux kernel).\n"
1542 " use 'src
=' to specify source address\n"
1543 " use 'dst
=' to specify destination address\n"
1544 " use 'udp
=on
' to specify udp encapsulation\n"
1545 " use 'srcport
=' to specify source udp port\n"
1546 " use 'dstport
=' to specify destination udp port\n"
1547 " use 'ipv6
=on
' to force v6\n"
1548 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1549 " well as a weak security measure\n"
1550 " use 'rxcookie
=0x012345678' to specify a rxcookie\n"
1551 " use 'txcookie
=0x012345678' to specify a txcookie\n"
1552 " use 'cookie64
=on
' to set cookie size to 64 bit, otherwise 32\n"
1553 " use 'counter
=off
' to force a 'cut
-down
' L2TPv3 with no counter\n"
1554 " use 'pincounter
=on
' to work around broken counter handling in peer\n"
1555 " use 'offset
=X
' to add an extra offset between header and data\n"
1557 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1558 " configure a network backend to connect to another network\n"
1559 " using a socket connection\n"
1560 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1561 " configure a network backend to connect to a multicast maddr and port\n"
1562 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1563 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1564 " configure a network backend to connect to another network\n"
1565 " using an UDP tunnel\n"
1567 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1568 " configure a network backend to connect to port 'n
' of a vde switch\n"
1569 " running on host and listening for incoming connections on 'socketpath
'.\n"
1570 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1571 " ownership and permissions for communication port.\n"
1573 #ifdef CONFIG_NETMAP
1574 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1575 " attach to the existing netmap-enabled network interface 'name
', or to a\n"
1576 " VALE port (created on the fly) called 'name
' ('nmname
' is name of the \n"
1577 " netmap device, defaults to '/dev
/netmap
')\n"
1579 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1580 " configure a vhost-user network, backed by a chardev 'dev
'\n"
1581 "-netdev hubport,id=str,hubid=n\n"
1582 " configure a hub port on QEMU VLAN 'n
'\n", QEMU_ARCH_ALL)
1583 DEF("net", HAS_ARG, QEMU_OPTION_net,
1584 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1585 " old way to create a new NIC and connect it to VLAN 'n
'\n"
1586 " (use the '-device devtype
,netdev
=str
' option if possible instead)\n"
1587 "-net dump[,vlan=n][,file=f][,len=n]\n"
1588 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
1589 "-net none use it alone to have zero network devices. If no -net option\n"
1590 " is provided, the default is '-net nic
-net user
'\n"
1600 #ifdef CONFIG_NETMAP
1603 "socket][,vlan=n][,option][,option][,...]\n"
1604 " old way to initialize a host network interface\n"
1605 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
1607 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1609 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1610 = 0 is the default). The NIC is an e1000 by default on the PC
1611 target. Optionally, the MAC address can be changed to @var{mac}, the
1612 device address set to @var{addr} (PCI cards only),
1613 and a @var{name} can be assigned for use in monitor commands.
1614 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1615 that the card should have; this option currently only affects virtio cards; set
1616 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1617 NIC is created. QEMU can emulate several different models of network card.
1618 Valid values for @var{type} are
1619 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1620 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1621 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1622 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1623 for a list of available devices for your target.
1625 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1627 @item -net user[,@var{option}][,@var{option}][,...]
1628 Use the user mode network stack which requires no administrator
1629 privilege to run. Valid options are:
1633 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1636 @itemx name=@var{name}
1637 Assign symbolic name for use in monitor commands.
1639 @item net=@var{addr}[/@var{mask}]
1640 Set IP network address the guest will see. Optionally specify the netmask,
1641 either in the form a.b.c.d or as number of valid top-most bits. Default is
1644 @item host=@var{addr}
1645 Specify the guest-visible address of the host. Default is the 2nd IP in the
1646 guest network, i.e. x.x.x.2.
1648 @item restrict=on|off
1649 If this option is enabled, the guest will be isolated, i.e. it will not be
1650 able to contact the host and no guest IP packets will be routed over the host
1651 to the outside. This option does not affect any explicitly set forwarding rules.
1653 @item hostname=@var{name}
1654 Specifies the client hostname reported by the built-in DHCP server.
1656 @item dhcpstart=@var{addr}
1657 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1658 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1660 @item dns=@var{addr}
1661 Specify the guest-visible address of the virtual nameserver. The address must
1662 be different from the host address. Default is the 3rd IP in the guest network,
1665 @item dnssearch=@var{domain}
1666 Provides an entry for the domain-search list sent by the built-in
1667 DHCP server. More than one domain suffix can be transmitted by specifying
1668 this option multiple times. If supported, this will cause the guest to
1669 automatically try to append the given domain suffix(es) in case a domain name
1670 can not be resolved.
1674 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1677 @item tftp=@var{dir}
1678 When using the user mode network stack, activate a built-in TFTP
1679 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1680 The TFTP client on the guest must be configured in binary mode (use the command
1681 @code{bin} of the Unix TFTP client).
1683 @item bootfile=@var{file}
1684 When using the user mode network stack, broadcast @var{file} as the BOOTP
1685 filename. In conjunction with @option{tftp}, this can be used to network boot
1686 a guest from a local directory.
1688 Example (using pxelinux):
1690 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1693 @item smb=@var{dir}[,smbserver=@var{addr}]
1694 When using the user mode network stack, activate a built-in SMB
1695 server so that Windows OSes can access to the host files in @file{@var{dir}}
1696 transparently. The IP address of the SMB server can be set to @var{addr}. By
1697 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1699 In the guest Windows OS, the line:
1703 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1704 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1706 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1708 Note that a SAMBA server must be installed on the host OS.
1709 QEMU was tested successfully with smbd versions from Red Hat 9,
1710 Fedora Core 3 and OpenSUSE 11.x.
1712 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1713 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1714 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1715 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1716 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1717 be bound to a specific host interface. If no connection type is set, TCP is
1718 used. This option can be given multiple times.
1720 For example, to redirect host X11 connection from screen 1 to guest
1721 screen 0, use the following:
1725 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1726 # this host xterm should open in the guest X11 server
1730 To redirect telnet connections from host port 5555 to telnet port on
1731 the guest, use the following:
1735 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1736 telnet localhost 5555
1739 Then when you use on the host @code{telnet localhost 5555}, you
1740 connect to the guest telnet server.
1742 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1743 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1744 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1745 to the character device @var{dev} or to a program executed by @var{cmd:command}
1746 which gets spawned for each connection. This option can be given multiple times.
1748 You can either use a chardev directly and have that one used throughout QEMU's
1749 lifetime
, like
in the following example
:
1752 # open
10.10.1.1:4321 on bootup
, connect
10.0.2.100:1234 to it whenever
1753 # the guest accesses it
1754 qemu
-net user
,guestfwd
=tcp
:10.0.2.100:1234-tcp
:10.10.1.1:4321 [...]
1757 Or you can execute a command on every TCP connection established by the guest
,
1758 so that QEMU behaves similar to an inetd process
for that virtual server
:
1761 # call
"netcat 10.10.1.1 4321" on every TCP connection to
10.0.2.100:1234
1762 # and connect the TCP stream to its stdin
/stdout
1763 qemu
-net
'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1768 Note
: Legacy stand
-alone options
-tftp
, -bootp
, -smb and
-redir are still
1769 processed and applied to
-net user
. Mixing them with the
new configuration
1770 syntax gives undefined results
. Their use
for new applications is discouraged
1771 as they will be removed from future versions
.
1773 @item
-netdev tap
,id
=@
var{id
}[,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1774 @itemx
-net tap
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1775 Connect the host TAP network
interface @
var{name
} to VLAN @
var{n
}.
1777 Use the network script @
var{file
} to configure it and the network script
1778 @
var{dfile
} to deconfigure it
. If @
var{name
} is not provided
, the OS
1779 automatically provides one
. The
default network configure script is
1780 @file
{/etc
/qemu
-ifup
} and the
default network deconfigure script is
1781 @file
{/etc
/qemu
-ifdown
}. Use @option
{script
=no
} or @option
{downscript
=no
}
1782 to disable script execution
.
1784 If running QEMU as an unprivileged user
, use the network helper
1785 @
var{helper
} to configure the TAP
interface. The
default network
1786 helper executable is @file
{/path
/to
/qemu
-bridge
-helper
}.
1788 @option
{fd
}=@
var{h
} can be used to specify the handle of an already
1789 opened host TAP
interface.
1794 #launch a QEMU instance with the
default network script
1795 qemu
-system
-i386 linux
.img
-net nic
-net tap
1799 #launch a QEMU instance with two NICs
, each one connected
1801 qemu
-system
-i386 linux
.img \
1802 -net nic
,vlan
=0 -net tap
,vlan
=0,ifname
=tap0 \
1803 -net nic
,vlan
=1 -net tap
,vlan
=1,ifname
=tap1
1807 #launch a QEMU instance with the
default network helper to
1808 #connect a TAP device to bridge br0
1809 qemu
-system
-i386 linux
.img \
1810 -net nic
-net tap
,"helper=/path/to/qemu-bridge-helper"
1813 @item
-netdev bridge
,id
=@
var{id
}[,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1814 @itemx
-net bridge
[,vlan
=@
var{n
}][,name
=@
var{name
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1815 Connect a host TAP network
interface to a host bridge device
.
1817 Use the network helper @
var{helper
} to configure the TAP
interface and
1818 attach it to the bridge
. The
default network helper executable is
1819 @file
{/path
/to
/qemu
-bridge
-helper
} and the
default bridge
1820 device is @file
{br0
}.
1825 #launch a QEMU instance with the
default network helper to
1826 #connect a TAP device to bridge br0
1827 qemu
-system
-i386 linux
.img
-net bridge
-net nic
,model
=virtio
1831 #launch a QEMU instance with the
default network helper to
1832 #connect a TAP device to bridge qemubr0
1833 qemu
-system
-i386 linux
.img
-net bridge
,br
=qemubr0
-net nic
,model
=virtio
1836 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1837 @itemx
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}] [,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1839 Connect the VLAN @
var{n
} to a remote VLAN
in another QEMU virtual
1840 machine
using a TCP socket connection
. If @option
{listen
} is
1841 specified
, QEMU waits
for incoming connections on @
var{port
}
1842 (@
var{host
} is optional
). @option
{connect
} is used to connect to
1843 another QEMU instance
using the @option
{listen
} option
. @option
{fd
}=@
var{h
}
1844 specifies an already opened TCP socket
.
1848 # launch a first QEMU instance
1849 qemu
-system
-i386 linux
.img \
1850 -net nic
,macaddr
=52:54:00:12:34:56 \
1851 -net socket
,listen
=:1234
1852 # connect the VLAN
0 of
this instance to the VLAN
0
1853 # of the first instance
1854 qemu
-system
-i386 linux
.img \
1855 -net nic
,macaddr
=52:54:00:12:34:57 \
1856 -net socket
,connect
=127.0.0.1:1234
1859 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1860 @itemx
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1862 Create a VLAN @
var{n
} shared with another QEMU virtual
1863 machines
using a UDP multicast socket
, effectively making a bus
for
1864 every QEMU with same multicast address @
var{maddr
} and @
var{port
}.
1868 Several QEMU can be running on different hosts and share same
bus (assuming
1869 correct multicast setup
for these hosts
).
1871 mcast support is compatible with User Mode
Linux (argument @option
{eth@
var{N
}=mcast
}), see
1872 @url
{http
://user-mode-linux.sf.net}.
1874 Use @option
{fd
=h
} to specify an already opened UDP multicast socket
.
1879 # launch one QEMU instance
1880 qemu
-system
-i386 linux
.img \
1881 -net nic
,macaddr
=52:54:00:12:34:56 \
1882 -net socket
,mcast
=230.0.0.1:1234
1883 # launch another QEMU instance on same
"bus"
1884 qemu
-system
-i386 linux
.img \
1885 -net nic
,macaddr
=52:54:00:12:34:57 \
1886 -net socket
,mcast
=230.0.0.1:1234
1887 # launch yet another QEMU instance on same
"bus"
1888 qemu
-system
-i386 linux
.img \
1889 -net nic
,macaddr
=52:54:00:12:34:58 \
1890 -net socket
,mcast
=230.0.0.1:1234
1893 Example (User Mode Linux compat
.):
1895 # launch QEMU
instance (note mcast address selected
1897 qemu-system-i386 linux.img \
1898 -net nic,macaddr=52:54:00:12:34:56 \
1899 -net socket,mcast=239.192.168.1:1102
1901 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1904 Example (send packets from host's
1.2.3.4):
1906 qemu
-system
-i386 linux
.img \
1907 -net nic
,macaddr
=52:54:00:12:34:56 \
1908 -net socket
,mcast
=239.192.168.1:1102,localaddr
=1.2.3.4
1911 @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
}]
1912 @itemx
-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
}]
1913 Connect VLAN @
var{n
} to L2TPv3 pseudowire
. L2TPv3 (RFC3391
) is a popular
1914 protocol to transport
Ethernet (and other Layer
2) data frames between
1915 two systems
. It is present
in routers
, firewalls and the Linux kernel
1916 (from version
3.3 onwards
).
1918 This transport allows a VM to communicate to another VM
, router or firewall directly
.
1920 @item src
=@
var{srcaddr
}
1921 source
address (mandatory
)
1922 @item dst
=@
var{dstaddr
}
1923 destination
address (mandatory
)
1925 select udp
encapsulation (default is ip
).
1926 @item srcport
=@
var{srcport
}
1928 @item dstport
=@
var{dstport
}
1929 destination udp port
.
1931 force v6
, otherwise defaults to v4
.
1932 @item rxcookie
=@
var{rxcookie
}
1933 @itemx txcookie
=@
var{txcookie
}
1934 Cookies are a weak form of security
in the l2tpv3 specification
.
1935 Their
function is mostly to prevent misconfiguration
. By
default they are
32
1938 Set cookie size to
64 bit instead of the
default 32
1940 Force a
'cut-down' L2TPv3 with no counter as
in
1941 draft
-mkonstan
-l2tpext
-keyed
-ipv6
-tunnel
-00
1943 Work around broken counter handling
in peer
. This may also help on
1944 networks which have packet reorder
.
1945 @item offset
=@
var{offset
}
1946 Add an extra offset between header and data
1948 For example
, to attach a VM running on host
4.3.2.1 via L2TPv3 to the bridge br
-lan
1949 on the remote Linux host
1.2.3.4:
1951 # Setup tunnel on linux host
using raw ip as encapsulation
1953 ip l2tp add tunnel remote
4.3.2.1 local
1.2.3.4 tunnel_id
1 peer_tunnel_id
1 \
1954 encap udp udp_sport
16384 udp_dport
16384
1955 ip l2tp add session tunnel_id
1 name vmtunnel0 session_id \
1956 0xFFFFFFFF peer_session_id
0xFFFFFFFF
1957 ifconfig vmtunnel0 mtu
1500
1958 ifconfig vmtunnel0 up
1959 brctl addif br
-lan vmtunnel0
1963 # launch QEMU instance
- if your network has reorder or is very lossy add
,pincounter
1965 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
1970 @item
-netdev vde
,id
=@
var{id
}[,sock
=@
var{socketpath
}][,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1971 @itemx
-net vde
[,vlan
=@
var{n
}][,name
=@
var{name
}][,sock
=@
var{socketpath
}] [,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1972 Connect VLAN @
var{n
} to PORT @
var{n
} of a vde
switch running on host and
1973 listening
for incoming connections on @
var{socketpath
}. Use GROUP @
var{groupname
}
1974 and MODE @
var{octalmode
} to change
default ownership and permissions
for
1975 communication port
. This option is only available
if QEMU has been compiled
1976 with vde support enabled
.
1981 vde_switch
-F
-sock
/tmp
/myswitch
1982 # launch QEMU instance
1983 qemu
-system
-i386 linux
.img
-net nic
-net vde
,sock
=/tmp
/myswitch
1986 @item
-netdev hubport
,id
=@
var{id
},hubid
=@
var{hubid
}
1988 Create a hub port on QEMU
"vlan" @
var{hubid
}.
1990 The hubport netdev lets you connect a NIC to a QEMU
"vlan" instead of a single
1991 netdev
. @code
{-net
} and @code
{-device
} with parameter @option
{vlan
} create the
1992 required hub automatically
.
1994 @item
-netdev vhost
-user
,chardev
=@
var{id
}[,vhostforce
=on|off
][,queues
=n
]
1996 Establish a vhost
-user netdev
, backed by a chardev @
var{id
}. The chardev should
1997 be a unix domain socket backed one
. The vhost
-user uses a specifically defined
1998 protocol to pass vhost ioctl replacement messages to an application on the other
1999 end of the socket
. On non
-MSIX guests
, the feature can be forced with
2000 @
var{vhostforce
}. Use
'queues=@var{n}' to specify the number of queues to
2001 be created
for multiqueue vhost
-user
.
2005 qemu
-m
512 -object memory
-backend
-file
,id
=mem
,size
=512M
,mem
-path
=/hugetlbfs
,share
=on \
2006 -numa node
,memdev
=mem \
2007 -chardev socket
,path
=/path
/to
/socket \
2008 -netdev type
=vhost
-user
,id
=net0
,chardev
=chr0 \
2009 -device virtio
-net
-pci
,netdev
=net0
2012 @item
-net dump
[,vlan
=@
var{n
}][,file
=@
var{file
}][,len
=@
var{len
}]
2013 Dump network traffic on VLAN @
var{n
} to file @
var{file
} (@file
{qemu
-vlan0
.pcap
} by
default).
2014 At most @
var{len
} bytes (64k by
default) per packet are stored
. The file format is
2015 libpcap
, so it can be analyzed with tools such as tcpdump or Wireshark
.
2016 Note
: For devices created with
'-netdev', use
'-object filter-dump,...' instead
.
2019 Indicate that no network devices should be configured
. It is used to
2020 override the
default configuration (@option
{-net nic
-net user
}) which
2021 is activated
if no @option
{-net
} options are provided
.
2029 DEFHEADING(Character device options
:)
2032 The general form of a character device option is
:
2036 DEF("chardev", HAS_ARG
, QEMU_OPTION_chardev
,
2037 "-chardev null,id=id[,mux=on|off]\n"
2038 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2039 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (tcp)\n"
2040 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (unix)\n"
2041 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2042 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2043 "-chardev msmouse,id=id[,mux=on|off]\n"
2044 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2046 "-chardev ringbuf,id=id[,size=size]\n"
2047 "-chardev file,id=id,path=path[,mux=on|off]\n"
2048 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
2050 "-chardev console,id=id[,mux=on|off]\n"
2051 "-chardev serial,id=id,path=path[,mux=on|off]\n"
2053 "-chardev pty,id=id[,mux=on|off]\n"
2054 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
2056 #ifdef CONFIG_BRLAPI
2057 "-chardev braille,id=id[,mux=on|off]\n"
2059 #
if defined(__linux__
) ||
defined(__sun__
) ||
defined(__FreeBSD__
) \
2060 ||
defined(__NetBSD__
) ||
defined(__OpenBSD__
) ||
defined(__DragonFly__
)
2061 "-chardev serial,id=id,path=path[,mux=on|off]\n"
2062 "-chardev tty,id=id,path=path[,mux=on|off]\n"
2064 #
if defined(__linux__
) ||
defined(__FreeBSD__
) ||
defined(__DragonFly__
)
2065 "-chardev parallel,id=id,path=path[,mux=on|off]\n"
2066 "-chardev parport,id=id,path=path[,mux=on|off]\n"
2068 #
if defined(CONFIG_SPICE
)
2069 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
2070 "-chardev spiceport,id=id,name=name[,debug=debug]\n"
2076 @item
-chardev @
var{backend
} ,id
=@
var{id
} [,mux
=on|off
] [,@
var{options
}]
2097 The specific backend will determine the applicable options
.
2099 All devices must have an id
, which can be any string up to
127 characters long
.
2100 It is used to uniquely identify
this device
in other command line directives
.
2102 A character device may be used
in multiplexing mode by multiple front
-ends
.
2103 The key sequence of @key
{Control
-a
} and @key
{c
} will rotate the input focus
2104 between attached front
-ends
. Specify @option
{mux
=on
} to enable
this mode
.
2106 Options to each backend are described below
.
2108 @item
-chardev
null ,id
=@
var{id
}
2109 A void device
. This device will not emit any data
, and will drop any data it
2110 receives
. The
null backend does not take any options
.
2112 @item
-chardev socket
,id
=@
var{id
} [@
var{TCP options
} or @
var{unix options
}] [,server
] [,nowait
] [,telnet
] [,reconnect
=@
var{seconds
}]
2114 Create a two
-way stream socket
, which can be either a TCP or a unix socket
. A
2115 unix socket will be created
if @option
{path
} is specified
. Behaviour is
2116 undefined
if TCP options are specified
for a unix socket
.
2118 @option
{server
} specifies that the socket shall be a listening socket
.
2120 @option
{nowait
} specifies that QEMU should not block waiting
for a client to
2121 connect to a listening socket
.
2123 @option
{telnet
} specifies that traffic on the socket should interpret telnet
2126 @option
{reconnect
} sets the timeout
for reconnecting on non
-server sockets when
2127 the remote end goes away
. qemu will delay
this many seconds and then attempt
2128 to reconnect
. Zero disables reconnecting
, and is the
default.
2130 TCP and unix socket options are given below
:
2134 @item TCP options
: port
=@
var{port
} [,host
=@
var{host
}] [,to
=@
var{to
}] [,ipv4
] [,ipv6
] [,nodelay
]
2136 @option
{host
} for a listening socket specifies the local address to be bound
.
2137 For a connecting socket species the remote host to connect to
. @option
{host
} is
2138 optional
for listening sockets
. If not specified it defaults to @code
{0.0.0.0}.
2140 @option
{port
} for a listening socket specifies the local port to be bound
. For a
2141 connecting socket specifies the port on the remote host to connect to
.
2142 @option
{port
} can be given as either a port number or a service name
.
2143 @option
{port
} is required
.
2145 @option
{to
} is only relevant to listening sockets
. If it is specified
, and
2146 @option
{port
} cannot be bound
, QEMU will attempt to bind to subsequent ports up
2147 to and including @option
{to
} until it succeeds
. @option
{to
} must be specified
2150 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2151 If neither is specified the socket may use either protocol
.
2153 @option
{nodelay
} disables the Nagle algorithm
.
2155 @item unix options
: path
=@
var{path
}
2157 @option
{path
} specifies the local path of the unix socket
. @option
{path
} is
2162 @item
-chardev udp
,id
=@
var{id
} [,host
=@
var{host
}] ,port
=@
var{port
} [,localaddr
=@
var{localaddr
}] [,localport
=@
var{localport
}] [,ipv4
] [,ipv6
]
2164 Sends all traffic from the guest to a remote host over UDP
.
2166 @option
{host
} specifies the remote host to connect to
. If not specified it
2167 defaults to @code
{localhost
}.
2169 @option
{port
} specifies the port on the remote host to connect to
. @option
{port
}
2172 @option
{localaddr
} specifies the local address to bind to
. If not specified it
2173 defaults to @code
{0.0.0.0}.
2175 @option
{localport
} specifies the local port to bind to
. If not specified any
2176 available local port will be used
.
2178 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2179 If neither is specified the device may use either protocol
.
2181 @item
-chardev msmouse
,id
=@
var{id
}
2183 Forward QEMU
's emulated msmouse events to the guest. @option{msmouse} does not
2186 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2188 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2191 @option{width} and @option{height} specify the width and height respectively of
2192 the console, in pixels.
2194 @option{cols} and @option{rows} specify that the console be sized to fit a text
2195 console with the given dimensions.
2197 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2199 Create a ring buffer with fixed size @option{size}.
2200 @var{size} must be a power of two, and defaults to @code{64K}).
2202 @item -chardev file ,id=@var{id} ,path=@var{path}
2204 Log all traffic received from the guest to a file.
2206 @option{path} specifies the path of the file to be opened. This file will be
2207 created if it does not already exist, and overwritten if it does. @option{path}
2210 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2212 Create a two-way connection to the guest. The behaviour differs slightly between
2213 Windows hosts and other hosts:
2215 On Windows, a single duplex pipe will be created at
2216 @file{\\.pipe\@option{path}}.
2218 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2219 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2220 received by the guest. Data written by the guest can be read from
2221 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2224 @option{path} forms part of the pipe path as described above. @option{path} is
2227 @item -chardev console ,id=@var{id}
2229 Send traffic from the guest to QEMU's standard output
. @option
{console
} does not
2232 @option
{console
} is only available on Windows hosts
.
2234 @item
-chardev serial
,id
=@
var{id
} ,path
=@option
{path
}
2236 Send traffic from the guest to a serial device on the host
.
2238 On Unix hosts serial will actually accept any tty device
,
2239 not only serial lines
.
2241 @option
{path
} specifies the name of the serial device to open
.
2243 @item
-chardev pty
,id
=@
var{id
}
2245 Create a
new pseudo
-terminal on the host and connect to it
. @option
{pty
} does
2246 not take any options
.
2248 @option
{pty
} is not available on Windows hosts
.
2250 @item
-chardev stdio
,id
=@
var{id
} [,signal
=on|off
]
2251 Connect to standard input and standard output of the QEMU process
.
2253 @option
{signal
} controls
if signals are enabled on the terminal
, that includes
2254 exiting QEMU with the key sequence @key
{Control
-c
}. This option is enabled by
2255 default, use @option
{signal
=off
} to disable it
.
2257 @option
{stdio
} is not available on Windows hosts
.
2259 @item
-chardev braille
,id
=@
var{id
}
2261 Connect to a local BrlAPI server
. @option
{braille
} does not take any options
.
2263 @item
-chardev tty
,id
=@
var{id
} ,path
=@
var{path
}
2265 @option
{tty
} is only available on Linux
, Sun
, FreeBSD
, NetBSD
, OpenBSD and
2266 DragonFlyBSD hosts
. It is an alias
for @option
{serial
}.
2268 @option
{path
} specifies the path to the tty
. @option
{path
} is required
.
2270 @item
-chardev parallel
,id
=@
var{id
} ,path
=@
var{path
}
2271 @itemx
-chardev parport
,id
=@
var{id
} ,path
=@
var{path
}
2273 @option
{parallel
} is only available on Linux
, FreeBSD and DragonFlyBSD hosts
.
2275 Connect to a local parallel port
.
2277 @option
{path
} specifies the path to the parallel port device
. @option
{path
} is
2280 @item
-chardev spicevmc
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2282 @option
{spicevmc
} is only available when spice support is built
in.
2284 @option
{debug
} debug level
for spicevmc
2286 @option
{name
} name of spice channel to connect to
2288 Connect to a spice virtual machine channel
, such as vdiport
.
2290 @item
-chardev spiceport
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2292 @option
{spiceport
} is only available when spice support is built
in.
2294 @option
{debug
} debug level
for spicevmc
2296 @option
{name
} name of spice port to connect to
2298 Connect to a spice port
, allowing a Spice client to handle the traffic
2299 identified by a
name (preferably a fqdn
).
2307 DEFHEADING(Device URL Syntax
:)
2310 In addition to
using normal file images
for the emulated storage devices
,
2311 QEMU can also use networked resources such as iSCSI devices
. These are
2312 specified
using a special URL syntax
.
2316 iSCSI support allows QEMU to access iSCSI resources directly and use as
2317 images
for the guest storage
. Both disk and cdrom images are supported
.
2319 Syntax
for specifying iSCSI LUNs is
2320 ``iscsi
://<target-ip>[:<port>]/<target-iqn>/<lun>''
2322 By
default qemu will use the iSCSI initiator
-name
2323 'iqn.2008-11.org.linux-kvm[:<name>]' but
this can also be set from the command
2324 line or a configuration file
.
2326 Since version Qemu
2.4 it is possible to specify a iSCSI request timeout to detect
2327 stalled requests and force a reestablishment of the session
. The timeout
2328 is specified
in seconds
. The
default is
0 which means no timeout
. Libiscsi
2329 1.15.0 or greater is required
for this feature
.
2331 Example (without authentication
):
2333 qemu
-system
-i386
-iscsi initiator
-name
=iqn
.2001-04.com
.example
:my
-initiator \
2334 -cdrom iscsi
://192.0.2.1/iqn.2001-04.com.example/2 \
2335 -drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2338 Example (CHAP username
/password via URL
):
2340 qemu
-system
-i386
-drive file
=iscsi
://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2343 Example (CHAP username
/password via environment variables
):
2345 LIBISCSI_CHAP_USERNAME
="user" \
2346 LIBISCSI_CHAP_PASSWORD
="password" \
2347 qemu
-system
-i386
-drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2350 iSCSI support is an optional feature of QEMU and only available when
2351 compiled and linked against libiscsi
.
2353 DEF("iscsi", HAS_ARG
, QEMU_OPTION_iscsi
,
2354 "-iscsi [user=user][,password=password]\n"
2355 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2356 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2357 " [,timeout=timeout]\n"
2358 " iSCSI session parameters\n", QEMU_ARCH_ALL
)
2361 iSCSI parameters such as username and password can also be specified via
2362 a configuration file
. See qemu
-doc
for more information and examples
.
2365 QEMU supports
NBD (Network Block Devices
) both
using TCP protocol as well
2366 as Unix Domain Sockets
.
2368 Syntax
for specifying a NBD device
using TCP
2369 ``nbd
:<server
-ip
>:<port
>[:exportname
=<export
>]''
2371 Syntax
for specifying a NBD device
using Unix Domain Sockets
2372 ``nbd
:unix
:<domain
-socket
>[:exportname
=<export
>]''
2377 qemu
-system
-i386
--drive file
=nbd
:192.0.2.1:30000
2380 Example
for Unix Domain Sockets
2382 qemu
-system
-i386
--drive file
=nbd
:unix
:/tmp
/nbd
-socket
2386 QEMU supports
SSH (Secure Shell
) access to remote disks
.
2390 qemu
-system
-i386
-drive file
=ssh
://user@@host/path/to/disk.img
2391 qemu
-system
-i386
-drive file
.driver
=ssh
,file
.user
=user
,file
.host
=host
,file
.port
=22,file
.path
=/path
/to
/disk
.img
2394 Currently authentication must be done
using ssh
-agent
. Other
2395 authentication methods may be supported
in future
.
2398 Sheepdog is a distributed storage system
for QEMU
.
2399 QEMU supports
using either local sheepdog devices or remote networked
2402 Syntax
for specifying a sheepdog device
2404 sheepdog
[+tcp|
+unix
]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2409 qemu
-system
-i386
--drive file
=sheepdog
://192.0.2.1:30000/MyVirtualMachine
2412 See also @url
{http
://http://www.osrg.net/sheepdog/}.
2415 GlusterFS is an user space distributed file system
.
2416 QEMU supports the use of GlusterFS volumes
for hosting VM disk images
using
2417 TCP
, Unix Domain Sockets and RDMA transport protocols
.
2419 Syntax
for specifying a VM disk image on GlusterFS volume is
2421 gluster
[+transport
]://[server[:port]]/volname/image[?socket=...]
2427 qemu
-system
-x86_64
--drive file
=gluster
://192.0.2.1/testvol/a.img
2430 See also @url
{http
://www.gluster.org}.
2432 @item HTTP
/HTTPS
/FTP
/FTPS
/TFTP
2433 QEMU supports read
-only access to files accessed over
http(s
), ftp(s
) and tftp
.
2435 Syntax
using a single filename
:
2437 <protocol
>://[<username>[:<password>]@@]<host>/<path>
2443 'http', 'https', 'ftp', 'ftps', or
'tftp'.
2446 Optional username
for authentication to the remote server
.
2449 Optional password
for authentication to the remote server
.
2452 Address of the remote server
.
2455 Path on the remote server
, including any query string
.
2458 The following options are also supported
:
2461 The full URL when passing options to the driver explicitly
.
2464 The amount of data to read ahead with each range request to the remote server
.
2465 This value may optionally have the suffix
'T', 'G', 'M', 'K', 'k' or
'b'. If it
2466 does not have a suffix
, it will be assumed to be
in bytes
. The value must be a
2467 multiple of
512 bytes
. It defaults to
256k
.
2470 Whether to verify the remote server
's certificate when connecting over SSL. It
2471 can have the value 'on
' or 'off
'. It defaults to 'on
'.
2474 Send this cookie (it can also be a list of cookies separated by ';') with
2475 each outgoing request. Only supported when using protocols such as HTTP
2476 which support cookies, otherwise ignored.
2479 Set the timeout in seconds of the CURL connection. This timeout is the time
2480 that CURL waits for a response from the remote server to get the size of the
2481 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2484 Note that when passing options to qemu explicitly, @option{driver} is the value
2487 Example: boot from a remote Fedora 20 live ISO image
2489 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
2491 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
2494 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2495 writes, copy-on-read, and a readahead of 64k
2497 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
2499 qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
2502 Example: boot from an image stored on a VMware vSphere server with a self-signed
2503 certificate using a local overlay for writes, a readahead of 64k and a timeout
2506 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
2508 qemu-system-x86_64 -drive file=/tmp/test.qcow2
2516 DEFHEADING(Bluetooth(R) options:)
2521 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2522 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands
\n" \
2523 "-bt hci
,host
[:id
]\n" \
2524 " use host
's HCI with the given name\n" \
2525 "-bt hci[,vlan=n]\n" \
2526 " emulate a standard HCI in virtual scatternet 'n
'\n" \
2527 "-bt vhci[,vlan=n]\n" \
2528 " add host computer to virtual scatternet 'n
' using VHCI\n" \
2529 "-bt device:dev[,vlan=n]\n" \
2530 " emulate a bluetooth device 'dev
' in scatternet 'n
'\n",
2535 Defines the function of the corresponding Bluetooth HCI. -bt options
2536 are matched with the HCIs present in the chosen machine type. For
2537 example when emulating a machine with only one HCI built into it, only
2538 the first @code{-bt hci[...]} option is valid and defines the HCI's
2539 logic
. The Transport Layer is decided by the machine type
. Currently
2540 the machines @code
{n800
} and @code
{n810
} have one HCI and all other
2544 The following three types are recognized
:
2548 (default) The corresponding Bluetooth HCI assumes no internal logic
2549 and will not respond to any HCI commands or emit events
.
2551 @item
-bt hci
,host
[:@
var{id
}]
2552 (@code
{bluez
} only
) The corresponding HCI passes commands
/ events
2553 to
/ from the physical HCI identified by the name @
var{id
} (default:
2554 @code
{hci0
}) on the computer running QEMU
. Only available on @code
{bluez
}
2555 capable systems like Linux
.
2557 @item
-bt hci
[,vlan
=@
var{n
}]
2558 Add a virtual
, standard HCI that will participate
in the Bluetooth
2559 scatternet @
var{n
} (default @code
{0}). Similarly to @option
{-net
}
2560 VLANs
, devices inside a bluetooth network @
var{n
} can only communicate
2561 with other devices
in the same
network (scatternet
).
2564 @item
-bt vhci
[,vlan
=@
var{n
}]
2565 (Linux
-host only
) Create a HCI
in scatternet @
var{n
} (default 0) attached
2566 to the host bluetooth stack instead of to the emulated target
. This
2567 allows the host and target machines to participate
in a common scatternet
2568 and communicate
. Requires the Linux @code
{vhci
} driver installed
. Can
2569 be used as following
:
2572 qemu
-system
-i386
[...OPTIONS
...] -bt hci
,vlan
=5 -bt vhci
,vlan
=5
2575 @item
-bt device
:@
var{dev
}[,vlan
=@
var{n
}]
2576 Emulate a bluetooth device @
var{dev
} and place it
in network @
var{n
}
2577 (default @code
{0}). QEMU can only emulate one type of bluetooth devices
2582 Virtual wireless keyboard implementing the HIDP bluetooth profile
.
2592 DEFHEADING(TPM device options
:)
2594 DEF("tpmdev", HAS_ARG
, QEMU_OPTION_tpmdev
, \
2595 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2596 " use path to provide path to a character device; default is /dev/tpm0\n"
2597 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2598 " not provided it will be searched for in /sys/class/misc/tpm?/device\n",
2602 The general form of a TPM device option is
:
2605 @item
-tpmdev @
var{backend
} ,id
=@
var{id
} [,@
var{options
}]
2607 Backend type must be
:
2608 @option
{passthrough
}.
2610 The specific backend type will determine the applicable options
.
2611 The @code
{-tpmdev
} option creates the TPM backend and requires a
2612 @code
{-device
} option that specifies the TPM frontend
interface model
.
2614 Options to each backend are described below
.
2616 Use
'help' to print all available TPM backend types
.
2621 @item
-tpmdev passthrough
, id
=@
var{id
}, path
=@
var{path
}, cancel
-path
=@
var{cancel
-path
}
2623 (Linux
-host only
) Enable access to the host
's TPM using the passthrough
2626 @option{path} specifies the path to the host's TPM device
, i
.e
., on
2627 a Linux host
this would be @code
{/dev
/tpm0
}.
2628 @option
{path
} is optional and by
default @code
{/dev
/tpm0
} is used
.
2630 @option
{cancel
-path
} specifies the path to the host TPM device
's sysfs
2631 entry allowing for cancellation of an ongoing TPM command.
2632 @option{cancel-path} is optional and by default QEMU will search for the
2635 Some notes about using the host's TPM with the passthrough driver
:
2637 The TPM device accessed by the passthrough driver must not be
2638 used by any other application on the host
.
2640 Since the host
's firmware (BIOS/UEFI) has already initialized the TPM,
2641 the VM's
firmware (BIOS
/UEFI
) will not be able to initialize the
2642 TPM again and may therefore not show a TPM
-specific menu that would
2643 otherwise allow the user to configure the TPM
, e
.g
., allow the user to
2644 enable
/disable or activate
/deactivate the TPM
.
2645 Further
, if TPM ownership is released from within a VM then the host
's TPM
2646 will get disabled and deactivated. To enable and activate the
2647 TPM again afterwards, the host has to be rebooted and the user is
2648 required to enter the firmware's menu to enable and activate the TPM
.
2649 If the TPM is left disabled and
/or deactivated most TPM commands will fail
.
2651 To create a passthrough TPM use the following two options
:
2653 -tpmdev passthrough
,id
=tpm0
-device tpm
-tis
,tpmdev
=tpm0
2655 Note that the @code
{-tpmdev
} id is @code
{tpm0
} and is referenced by
2656 @code
{tpmdev
=tpm0
} in the device option
.
2666 DEFHEADING(Linux
/Multiboot boot specific
:)
2669 When
using these options
, you can use a given Linux or Multiboot
2670 kernel without installing it
in the disk image
. It can be useful
2671 for easier testing of various kernels
.
2676 DEF("kernel", HAS_ARG
, QEMU_OPTION_kernel
, \
2677 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL
)
2679 @item
-kernel @
var{bzImage
}
2681 Use @
var{bzImage
} as kernel image
. The kernel can be either a Linux kernel
2682 or
in multiboot format
.
2685 DEF("append", HAS_ARG
, QEMU_OPTION_append
, \
2686 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL
)
2688 @item
-append @
var{cmdline
}
2690 Use @
var{cmdline
} as kernel command line
2693 DEF("initrd", HAS_ARG
, QEMU_OPTION_initrd
, \
2694 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL
)
2696 @item
-initrd @
var{file
}
2698 Use @
var{file
} as initial ram disk
.
2700 @item
-initrd
"@var{file1} arg=foo,@var{file2}"
2702 This syntax is only available with multiboot
.
2704 Use @
var{file1
} and @
var{file2
} as modules and pass arg
=foo as parameter to the
2708 DEF("dtb", HAS_ARG
, QEMU_OPTION_dtb
, \
2709 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL
)
2711 @item
-dtb @
var{file
}
2713 Use @
var{file
} as a device tree
binary (dtb
) image and pass it to the kernel
2722 DEFHEADING(Debug
/Expert options
:)
2727 DEF("fw_cfg", HAS_ARG
, QEMU_OPTION_fwcfg
,
2728 "-fw_cfg [name=]<name>,file=<file>\n"
2729 " add named fw_cfg entry from file\n"
2730 "-fw_cfg [name=]<name>,string=<str>\n"
2731 " add named fw_cfg entry from string\n",
2734 @item
-fw_cfg
[name
=]@
var{name
},file
=@
var{file
}
2736 Add named fw_cfg entry from file
. @
var{name
} determines the name of
2737 the entry
in the fw_cfg file directory exposed to the guest
.
2739 @item
-fw_cfg
[name
=]@
var{name
},string
=@
var{str
}
2740 Add named fw_cfg entry from string
.
2743 DEF("serial", HAS_ARG
, QEMU_OPTION_serial
, \
2744 "-serial dev redirect the serial port to char device 'dev'\n",
2747 @item
-serial @
var{dev
}
2749 Redirect the virtual serial port to host character device
2750 @
var{dev
}. The
default device is @code
{vc
} in graphical mode and
2751 @code
{stdio
} in non graphical mode
.
2753 This option can be used several times to simulate up to
4 serial
2756 Use @code
{-serial none
} to disable all serial ports
.
2758 Available character devices are
:
2760 @item vc
[:@
var{W
}x@
var{H
}]
2761 Virtual console
. Optionally
, a width and height can be given
in pixel with
2765 It is also possible to specify width or height
in characters
:
2770 [Linux only
] Pseudo
TTY (a
new PTY is automatically allocated
)
2772 No device is allocated
.
2775 @item chardev
:@
var{id
}
2776 Use a named character device defined with the @code
{-chardev
} option
.
2778 [Linux only
] Use host tty
, e
.g
. @file
{/dev
/ttyS0
}. The host serial port
2779 parameters are set according to the emulated ones
.
2780 @item
/dev
/parport@
var{N
}
2781 [Linux only
, parallel port only
] Use host parallel port
2782 @
var{N
}. Currently SPP and EPP parallel port features can be used
.
2783 @item file
:@
var{filename
}
2784 Write output to @
var{filename
}. No character can be read
.
2786 [Unix only
] standard input
/output
2787 @item pipe
:@
var{filename
}
2788 name pipe @
var{filename
}
2790 [Windows only
] Use host serial port @
var{n
}
2791 @item udp
:[@
var{remote_host
}]:@
var{remote_port
}[@@
[@
var{src_ip
}]:@
var{src_port
}]
2792 This
implements UDP Net Console
.
2793 When @
var{remote_host
} or @
var{src_ip
} are not specified
2794 they
default to @code
{0.0.0.0}.
2795 When not
using a specified @
var{src_port
} a random port is automatically chosen
.
2797 If you just want a simple readonly console you can use @code
{netcat
} or
2798 @code
{nc
}, by starting QEMU with
: @code
{-serial udp
::4555} and nc as
:
2799 @code
{nc
-u
-l
-p
4555}. Any time QEMU writes something to that port it
2800 will appear
in the netconsole session
.
2802 If you plan to send characters back via netconsole or you want to stop
2803 and start QEMU a lot of times
, you should have QEMU use the same
2804 source port each time by
using something like @code
{-serial
2805 udp
::4555@@
:4556} to QEMU
. Another approach is to use a patched
2806 version of netcat which can listen to a TCP port and send and receive
2807 characters via udp
. If you have a patched version of netcat which
2808 activates telnet remote echo and single char transfer
, then you can
2809 use the following options to step up a netcat redirector to allow
2810 telnet on port
5555 to access the QEMU port
.
2813 -serial udp
::4555@@
:4556
2814 @item netcat options
:
2815 -u
-P
4555 -L
0.0.0.0:4556 -t
-p
5555 -I
-T
2816 @item telnet options
:
2820 @item tcp
:[@
var{host
}]:@
var{port
}[,@
var{server
}][,nowait
][,nodelay
][,reconnect
=@
var{seconds
}]
2821 The TCP Net Console has two modes of operation
. It can send the serial
2822 I
/O to a location or wait
for a connection from a location
. By
default
2823 the TCP Net Console is sent to @
var{host
} at the @
var{port
}. If you use
2824 the @
var{server
} option QEMU will wait
for a client socket application
2825 to connect to the port before continuing
, unless the @code
{nowait
}
2826 option was specified
. The @code
{nodelay
} option disables the Nagle buffering
2827 algorithm
. The @code
{reconnect
} option only applies
if @
var{noserver
} is
2828 set
, if the connection goes down it will attempt to reconnect at the
2829 given interval
. If @
var{host
} is omitted
, 0.0.0.0 is assumed
. Only
2830 one TCP connection at a time is accepted
. You can use @code
{telnet
} to
2831 connect to the corresponding character device
.
2833 @item Example to send tcp console to
192.168.0.2 port
4444
2834 -serial tcp
:192.168.0.2:4444
2835 @item Example to listen and wait on port
4444 for connection
2836 -serial tcp
::4444,server
2837 @item Example to not wait and listen on ip
192.168.0.100 port
4444
2838 -serial tcp
:192.168.0.100:4444,server
,nowait
2841 @item telnet
:@
var{host
}:@
var{port
}[,server
][,nowait
][,nodelay
]
2842 The telnet protocol is used instead of raw tcp sockets
. The options
2843 work the same as
if you had specified @code
{-serial tcp
}. The
2844 difference is that the port acts like a telnet server or client
using
2845 telnet option negotiation
. This will also allow you to send the
2846 MAGIC_SYSRQ sequence
if you use a telnet that supports sending the
break
2847 sequence
. Typically
in unix telnet you
do it with Control
-] and then
2848 type
"send break" followed by pressing the enter key
.
2850 @item unix
:@
var{path
}[,server
][,nowait
][,reconnect
=@
var{seconds
}]
2851 A unix domain socket is used instead of a tcp socket
. The option works the
2852 same as
if you had specified @code
{-serial tcp
} except the unix domain socket
2853 @
var{path
} is used
for connections
.
2855 @item mon
:@
var{dev_string
}
2856 This is a special option to allow the monitor to be multiplexed onto
2857 another serial port
. The monitor is accessed with key sequence of
2858 @key
{Control
-a
} and then pressing @key
{c
}.
2859 @
var{dev_string
} should be any one of the serial devices specified
2860 above
. An example to multiplex the monitor onto a telnet server
2861 listening on port
4444 would be
:
2863 @item
-serial mon
:telnet
::4444,server
,nowait
2865 When the monitor is multiplexed to stdio
in this way
, Ctrl
+C will not terminate
2866 QEMU any more but will be passed to the guest instead
.
2869 Braille device
. This will use BrlAPI to display the braille output on a real
2873 Three button serial mouse
. Configure the guest to use Microsoft protocol
.
2877 DEF("parallel", HAS_ARG
, QEMU_OPTION_parallel
, \
2878 "-parallel dev redirect the parallel port to char device 'dev'\n",
2881 @item
-parallel @
var{dev
}
2883 Redirect the virtual parallel port to host device @
var{dev
} (same
2884 devices as the serial port
). On Linux hosts
, @file
{/dev
/parportN
} can
2885 be used to use hardware devices connected on the corresponding host
2888 This option can be used several times to simulate up to
3 parallel
2891 Use @code
{-parallel none
} to disable all parallel ports
.
2894 DEF("monitor", HAS_ARG
, QEMU_OPTION_monitor
, \
2895 "-monitor dev redirect the monitor to char device 'dev'\n",
2898 @item
-monitor @
var{dev
}
2900 Redirect the monitor to host device @
var{dev
} (same devices as the
2902 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2904 Use @code
{-monitor none
} to disable the
default monitor
.
2906 DEF("qmp", HAS_ARG
, QEMU_OPTION_qmp
, \
2907 "-qmp dev like -monitor but opens in 'control' mode\n",
2910 @item
-qmp @
var{dev
}
2912 Like
-monitor but opens
in 'control' mode
.
2914 DEF("qmp-pretty", HAS_ARG
, QEMU_OPTION_qmp_pretty
, \
2915 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
2918 @item
-qmp
-pretty @
var{dev
}
2920 Like
-qmp but uses pretty JSON formatting
.
2923 DEF("mon", HAS_ARG
, QEMU_OPTION_mon
, \
2924 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL
)
2926 @item
-mon
[chardev
=]name
[,mode
=readline|control
][,default]
2928 Setup monitor on chardev @
var{name
}.
2931 DEF("debugcon", HAS_ARG
, QEMU_OPTION_debugcon
, \
2932 "-debugcon dev redirect the debug console to char device 'dev'\n",
2935 @item
-debugcon @
var{dev
}
2937 Redirect the debug console to host device @
var{dev
} (same devices as the
2938 serial port
). The debug console is an I
/O port which is typically port
2939 0xe9; writing to that I
/O port sends output to
this device
.
2940 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2944 DEF("pidfile", HAS_ARG
, QEMU_OPTION_pidfile
, \
2945 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL
)
2947 @item
-pidfile @
var{file
}
2949 Store the QEMU process PID
in @
var{file
}. It is useful
if you launch QEMU
2953 DEF("singlestep", 0, QEMU_OPTION_singlestep
, \
2954 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL
)
2958 Run the emulation
in single step mode
.
2961 DEF("S", 0, QEMU_OPTION_S
, \
2962 "-S freeze CPU at startup (use 'c' to start execution)\n",
2967 Do not start CPU at
startup (you must type
'c' in the monitor
).
2970 DEF("realtime", HAS_ARG
, QEMU_OPTION_realtime
,
2971 "-realtime [mlock=on|off]\n"
2972 " run qemu with realtime features\n"
2973 " mlock=on|off controls mlock support (default: on)\n",
2976 @item
-realtime mlock
=on|off
2978 Run qemu with realtime features
.
2979 mlocking qemu and guest memory can be enabled via @option
{mlock
=on
}
2980 (enabled by
default).
2983 DEF("gdb", HAS_ARG
, QEMU_OPTION_gdb
, \
2984 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL
)
2986 @item
-gdb @
var{dev
}
2988 Wait
for gdb connection on device @
var{dev
} (@pxref
{gdb_usage
}). Typical
2989 connections will likely be TCP
-based
, but also UDP
, pseudo TTY
, or even
2990 stdio are reasonable use
case. The latter is allowing to start QEMU from
2991 within gdb and establish the connection via a pipe
:
2993 (gdb
) target remote | exec qemu
-system
-i386
-gdb stdio
...
2997 DEF("s", 0, QEMU_OPTION_s
, \
2998 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT
"\n",
3003 Shorthand
for -gdb tcp
::1234, i
.e
. open a gdbserver on TCP port
1234
3004 (@pxref
{gdb_usage
}).
3007 DEF("d", HAS_ARG
, QEMU_OPTION_d
, \
3008 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
3011 @item
-d @
var{item1
}[,...]
3013 Enable logging of specified items
. Use
'-d help' for a list of log items
.
3016 DEF("D", HAS_ARG
, QEMU_OPTION_D
, \
3017 "-D logfile output log to logfile (default stderr)\n",
3020 @item
-D @
var{logfile
}
3022 Output log
in @
var{logfile
} instead of to stderr
3025 DEF("L", HAS_ARG
, QEMU_OPTION_L
, \
3026 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
3031 Set the directory
for the BIOS
, VGA BIOS and keymaps
.
3034 DEF("bios", HAS_ARG
, QEMU_OPTION_bios
, \
3035 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL
)
3037 @item
-bios @
var{file
}
3039 Set the filename
for the BIOS
.
3042 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm
, \
3043 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL
)
3047 Enable KVM full virtualization support
. This option is only available
3048 if KVM support is enabled when compiling
.
3051 DEF("xen-domid", HAS_ARG
, QEMU_OPTION_xen_domid
,
3052 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL
)
3053 DEF("xen-create", 0, QEMU_OPTION_xen_create
,
3054 "-xen-create create domain using xen hypercalls, bypassing xend\n"
3055 " warning: should not be used when xend is in use\n",
3057 DEF("xen-attach", 0, QEMU_OPTION_xen_attach
,
3058 "-xen-attach attach to existing xen domain\n"
3059 " xend will use this when starting QEMU\n",
3062 @item
-xen
-domid @
var{id
}
3064 Specify xen guest domain @
var{id
} (XEN only
).
3067 Create domain
using xen hypercalls
, bypassing xend
.
3068 Warning
: should not be used when xend is
in use (XEN only
).
3071 Attach to existing xen domain
.
3072 xend will use
this when starting
QEMU (XEN only
).
3075 DEF("no-reboot", 0, QEMU_OPTION_no_reboot
, \
3076 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL
)
3080 Exit instead of rebooting
.
3083 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown
, \
3084 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL
)
3087 @findex
-no
-shutdown
3088 Don
't exit QEMU on guest shutdown, but instead only stop the emulation.
3089 This allows for instance switching to monitor to commit changes to the
3093 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3094 "-loadvm [tag|id]\n" \
3095 " start right away with a saved state (loadvm in monitor)\n",
3098 @item -loadvm @var{file}
3100 Start right away with a saved state (@code{loadvm} in monitor)
3104 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3105 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3110 Daemonize the QEMU process after initialization. QEMU will not detach from
3111 standard IO until it is ready to receive connections on any of its devices.
3112 This option is a useful way for external programs to launch QEMU without having
3113 to cope with initialization race conditions.
3116 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3117 "-option-rom rom load a file, rom, into the option ROM space\n",
3120 @item -option-rom @var{file}
3122 Load the contents of @var{file} as an option ROM.
3123 This option is useful to load things like EtherBoot.
3126 HXCOMM Silently ignored for compatibility
3127 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3129 HXCOMM Options deprecated by -rtc
3130 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3131 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3133 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3134 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3135 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3140 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3142 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3143 UTC or local time, respectively. @code{localtime} is required for correct date in
3144 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3145 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3147 By default the RTC is driven by the host system time. This allows using of the
3148 RTC as accurate reference clock inside the guest, specifically if the host
3149 time is smoothly following an accurate external reference clock, e.g. via NTP.
3150 If you want to isolate the guest time from the host, you can set @option{clock}
3151 to @code{rt} instead. To even prevent it from progressing during suspension,
3152 you can set it to @code{vm}.
3154 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3155 specifically with Windows' ACPI HAL
. This option will
try to figure out how
3156 many timer interrupts were not processed by the Windows guest and will
3160 DEF("icount", HAS_ARG
, QEMU_OPTION_icount
, \
3161 "-icount [shift=N|auto][,align=on|off][,sleep=no,rr=record|replay,rrfile=<filename>]\n" \
3162 " enable virtual instruction counter with 2^N clock ticks per\n" \
3163 " instruction, enable aligning the host and virtual clocks\n" \
3164 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL
)
3166 @item
-icount
[shift
=@
var{N
}|auto
][,rr
=record|replay
,rrfile
=@
var{filename
}]
3168 Enable virtual instruction counter
. The virtual cpu will execute one
3169 instruction every
2^@
var{N
} ns of virtual time
. If @code
{auto
} is specified
3170 then the virtual cpu speed will be automatically adjusted to keep virtual
3171 time within a few seconds of real time
.
3173 When the virtual cpu is sleeping
, the virtual time will advance at
default
3174 speed unless @option
{sleep
=no
} is specified
.
3175 With @option
{sleep
=no
}, the virtual time will jump to the next timer deadline
3176 instantly whenever the virtual cpu goes to sleep mode and will not advance
3177 if no timer is enabled
. This behavior give deterministic execution times from
3178 the guest point of view
.
3180 Note that
while this option can give deterministic behavior
, it does not
3181 provide cycle accurate emulation
. Modern CPUs contain superscalar out of
3182 order cores with complex cache hierarchies
. The number of instructions
3183 executed often has little or no correlation with actual performance
.
3185 @option
{align
=on
} will activate the delay algorithm which will
try
3186 to synchronise the host clock and the virtual clock
. The goal is to
3187 have a guest running at the real frequency imposed by the shift option
.
3188 Whenever the guest clock is behind the host clock and
if
3189 @option
{align
=on
} is specified then we print a message to the user
3190 to inform about the delay
.
3191 Currently
this option does not work when @option
{shift
} is @code
{auto
}.
3192 Note
: The sync algorithm will work
for those shift values
for which
3193 the guest clock runs ahead of the host clock
. Typically
this happens
3194 when the shift value is
high (how high depends on the host machine
).
3196 When @option
{rr
} option is specified deterministic record
/replay is enabled
.
3197 Replay log is written into @
var{filename
} file
in record mode and
3198 read from
this file
in replay mode
.
3201 DEF("watchdog", HAS_ARG
, QEMU_OPTION_watchdog
, \
3202 "-watchdog model\n" \
3203 " enable virtual hardware watchdog [default=none]\n",
3206 @item
-watchdog @
var{model
}
3208 Create a virtual hardware watchdog device
. Once
enabled (by a guest
3209 action
), the watchdog must be periodically polled by an agent inside
3210 the guest or
else the guest will be restarted
. Choose a model
for
3211 which your guest has drivers
.
3213 The @
var{model
} is the model of hardware watchdog to emulate
. Use
3214 @code
{-watchdog help
} to list available hardware models
. Only one
3215 watchdog can be enabled
for a guest
.
3217 The following models may be available
:
3220 iBASE
700 is a very simple ISA watchdog with a single timer
.
3222 Intel
6300ESB I
/O controller hub is a much more featureful PCI
-based
3223 dual
-timer watchdog
.
3225 A virtual watchdog
for s390x backed by the diagnose
288 hypercall
3226 (currently KVM only
).
3230 DEF("watchdog-action", HAS_ARG
, QEMU_OPTION_watchdog_action
, \
3231 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3232 " action when watchdog fires [default=reset]\n",
3235 @item
-watchdog
-action @
var{action
}
3236 @findex
-watchdog
-action
3238 The @
var{action
} controls what QEMU will
do when the watchdog timer
3241 @code
{reset
} (forcefully reset the guest
).
3242 Other possible actions are
:
3243 @code
{shutdown
} (attempt to gracefully shutdown the guest
),
3244 @code
{poweroff
} (forcefully poweroff the guest
),
3245 @code
{pause
} (pause the guest
),
3246 @code
{debug
} (print a debug message and
continue), or
3247 @code
{none
} (do nothing
).
3249 Note that the @code
{shutdown
} action requires that the guest responds
3250 to ACPI signals
, which it may not be able to
do in the sort of
3251 situations where the watchdog would have expired
, and thus
3252 @code
{-watchdog
-action shutdown
} is not recommended
for production use
.
3257 @item
-watchdog i6300esb
-watchdog
-action pause
3258 @itemx
-watchdog ib700
3262 DEF("echr", HAS_ARG
, QEMU_OPTION_echr
, \
3263 "-echr chr set terminal escape character instead of ctrl-a\n",
3267 @item
-echr @
var{numeric_ascii_value
}
3269 Change the escape character used
for switching to the monitor when
using
3270 monitor and serial sharing
. The
default is @code
{0x01} when
using the
3271 @code
{-nographic
} option
. @code
{0x01} is equal to pressing
3272 @code
{Control
-a
}. You can select a different character from the ascii
3273 control keys where
1 through
26 map to Control
-a through Control
-z
. For
3274 instance you could use the either of the following to change the escape
3275 character to Control
-t
.
3282 DEF("virtioconsole", HAS_ARG
, QEMU_OPTION_virtiocon
, \
3283 "-virtioconsole c\n" \
3284 " set virtio console\n", QEMU_ARCH_ALL
)
3286 @item
-virtioconsole @
var{c
}
3287 @findex
-virtioconsole
3290 This option is maintained
for backward compatibility
.
3292 Please use @code
{-device virtconsole
} for the
new way of invocation
.
3295 DEF("show-cursor", 0, QEMU_OPTION_show_cursor
, \
3296 "-show-cursor show cursor\n", QEMU_ARCH_ALL
)
3299 @findex
-show
-cursor
3303 DEF("tb-size", HAS_ARG
, QEMU_OPTION_tb_size
, \
3304 "-tb-size n set TB size\n", QEMU_ARCH_ALL
)
3306 @item
-tb
-size @
var{n
}
3311 DEF("incoming", HAS_ARG
, QEMU_OPTION_incoming
, \
3312 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3313 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3314 "-incoming unix:socketpath\n" \
3315 " prepare for incoming migration, listen on\n" \
3316 " specified protocol and socket address\n" \
3317 "-incoming fd:fd\n" \
3318 "-incoming exec:cmdline\n" \
3319 " accept incoming migration on given file descriptor\n" \
3320 " or from given external command\n" \
3321 "-incoming defer\n" \
3322 " wait for the URI to be specified via migrate_incoming\n",
3325 @item
-incoming tcp
:[@
var{host
}]:@
var{port
}[,to
=@
var{maxport
}][,ipv4
][,ipv6
]
3326 @itemx
-incoming rdma
:@
var{host
}:@
var{port
}[,ipv4
][,ipv6
]
3328 Prepare
for incoming migration
, listen on a given tcp port
.
3330 @item
-incoming unix
:@
var{socketpath
}
3331 Prepare
for incoming migration
, listen on a given unix socket
.
3333 @item
-incoming fd
:@
var{fd
}
3334 Accept incoming migration from a given filedescriptor
.
3336 @item
-incoming exec
:@
var{cmdline
}
3337 Accept incoming migration as an output from specified external command
.
3339 @item
-incoming defer
3340 Wait
for the URI to be specified via migrate_incoming
. The monitor can
3341 be used to change
settings (such as migration parameters
) prior to issuing
3342 the migrate_incoming to allow the migration to begin
.
3345 DEF("nodefaults", 0, QEMU_OPTION_nodefaults
, \
3346 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL
)
3350 Don
't create default devices. Normally, QEMU sets the default devices like serial
3351 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3352 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3357 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3358 "-chroot dir chroot to dir just before starting the VM\n",
3362 @item -chroot @var{dir}
3364 Immediately before starting guest execution, chroot to the specified
3365 directory. Especially useful in combination with -runas.
3369 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3370 "-runas user change to user id user just before starting the VM\n",
3374 @item -runas @var{user}
3376 Immediately before starting guest execution, drop root privileges, switching
3377 to the specified user.
3380 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3381 "-prom-env variable=value\n"
3382 " set OpenBIOS nvram variables\n",
3383 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3385 @item -prom-env @var{variable}=@var{value}
3387 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3389 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3390 "-semihosting semihosting mode\n",
3391 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3395 @findex -semihosting
3396 Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3398 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3399 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3400 " semihosting configuration\n",
3401 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3404 @item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3405 @findex -semihosting-config
3406 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3408 @item target=@code{native|gdb|auto}
3409 Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3410 or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3411 during debug sessions and @code{native} otherwise.
3412 @item arg=@var{str1},arg=@var{str2},...
3413 Allows the user to pass input arguments, and can be used multiple times to build
3414 up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3415 command line is still supported for backward compatibility. If both the
3416 @code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3417 specified, the former is passed to semihosting as it always takes precedence.
3420 DEF("old-param", 0, QEMU_OPTION_old_param,
3421 "-old-param old param mode\n", QEMU_ARCH_ARM)
3424 @findex -old-param (ARM)
3425 Old param mode (ARM only).
3428 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3429 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off
').\n",
3432 @item -sandbox @var{arg}
3434 Enable Seccomp mode 2 system call filter. 'on
' will enable syscall filtering and 'off
' will
3435 disable it. The default is 'off
'.
3438 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3439 "-readconfig <file>\n", QEMU_ARCH_ALL)
3441 @item -readconfig @var{file}
3443 Read device configuration from @var{file}. This approach is useful when you want to spawn
3444 QEMU process with many command line options but you don't want to exceed the command line
3447 DEF("writeconfig", HAS_ARG
, QEMU_OPTION_writeconfig
,
3448 "-writeconfig <file>\n"
3449 " read/write config file\n", QEMU_ARCH_ALL
)
3451 @item
-writeconfig @
var{file
}
3452 @findex
-writeconfig
3453 Write device configuration to @
var{file
}. The @
var{file
} can be either filename to save
3454 command line and device configuration into file or dash @code
{-}) character to print the
3455 output to stdout
. This can be later used as input file
for @code
{-readconfig
} option
.
3457 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig
,
3459 " do not load default config files at startup\n",
3463 @findex
-nodefconfig
3464 Normally QEMU loads configuration files from @
var{sysconfdir
} and @
var{datadir
} at startup
.
3465 The @code
{-nodefconfig
} option will prevent QEMU from loading any of those config files
.
3467 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig
,
3469 " do not load user-provided config files at startup\n",
3472 @item
-no
-user
-config
3473 @findex
-no
-user
-config
3474 The @code
{-no
-user
-config
} option makes QEMU not load any of the user
-provided
3475 config files on @
var{sysconfdir
}, but won
't make it skip the QEMU-provided config
3476 files from @var{datadir}.
3478 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3479 "-trace [events=<file>][,file=<file>]\n"
3480 " specify tracing options\n",
3483 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3484 HXCOMM HX does not support conditional compilation of text.
3485 @item -trace [events=@var{file}][,file=@var{file}]
3488 Specify tracing options.
3491 @item events=@var{file}
3492 Immediately enable events listed in @var{file}.
3493 The file must contain one event name (as listed in the @var{trace-events} file)
3495 This option is only available if QEMU has been compiled with
3496 either @var{simple} or @var{stderr} tracing backend.
3497 @item file=@var{file}
3498 Log output traces to @var{file}.
3500 This option is only available if QEMU has been compiled with
3501 the @var{simple} tracing backend.
3506 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3507 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3510 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3511 "-enable-fips enable FIPS 140-2 compliance\n",
3516 @findex -enable-fips
3517 Enable FIPS 140-2 compliance mode.
3520 HXCOMM Deprecated by -machine accel=tcg property
3521 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3523 HXCOMM Deprecated by kvm-pit driver properties
3524 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3527 HXCOMM Deprecated (ignored)
3528 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
3530 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3531 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3533 HXCOMM Deprecated (ignored)
3534 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3536 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3537 "-msg timestamp[=on|off]\n"
3538 " change the format of messages\n"
3539 " on|off controls leading timestamps (default:on)\n",
3542 @item -msg timestamp[=on|off]
3544 prepend a timestamp to each log message.(default:on)
3547 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3548 "-dump-vmstate <file>\n"
3549 " Output vmstate information in JSON format to file.\n"
3550 " Use the scripts/vmstate-static-checker.py file to\n"
3551 " check for possible regressions in migration code\n"
3552 " by comparing two such vmstate dumps.\n",
3555 @item -dump-vmstate @var{file}
3556 @findex -dump-vmstate
3557 Dump json-encoded vmstate information for current machine type to file
3561 DEFHEADING(Generic object creation)
3563 DEF("object", HAS_ARG, QEMU_OPTION_object,
3564 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3565 " create a new object of type TYPENAME setting properties\n"
3566 " in the order they are specified. Note that the 'id
'\n"
3567 " property must be set. These objects are placed in the\n"
3568 " '/objects
' path.\n",
3571 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3573 Create a new object of type @var{typename} setting properties
3574 in the order they are specified. Note that the 'id
'
3575 property must be set. These objects are placed in the
3580 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off}
3582 Creates a memory file backend object, which can be used to back
3583 the guest RAM with huge pages. The @option{id} parameter is a
3584 unique ID that will be used to reference this memory region
3585 when configuring the @option{-numa} argument. The @option{size}
3586 option provides the size of the memory region, and accepts
3587 common suffixes, eg @option{500M}. The @option{mem-path} provides
3588 the path to either a shared memory or huge page filesystem mount.
3589 The @option{share} boolean option determines whether the memory
3590 region is marked as private to QEMU, or shared. The latter allows
3591 a co-operating external process to access the QEMU memory region.
3593 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
3595 Creates a random number generator backend which obtains entropy from
3596 a device on the host. The @option{id} parameter is a unique ID that
3597 will be used to reference this entropy backend from the @option{virtio-rng}
3598 device. The @option{filename} parameter specifies which file to obtain
3599 entropy from and if omitted defaults to @option{/dev/random}.
3601 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
3603 Creates a random number generator backend which obtains entropy from
3604 an external daemon running on the host. The @option{id} parameter is
3605 a unique ID that will be used to reference this entropy backend from
3606 the @option{virtio-rng} device. The @option{chardev} parameter is
3607 the unique ID of a character device backend that provides the connection
3610 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
3612 Creates a TLS anonymous credentials object, which can be used to provide
3613 TLS support on network backends. The @option{id} parameter is a unique
3614 ID which network backends will use to access the credentials. The
3615 @option{endpoint} is either @option{server} or @option{client} depending
3616 on whether the QEMU network backend that uses the credentials will be
3617 acting as a client or as a server. If @option{verify-peer} is enabled
3618 (the default) then once the handshake is completed, the peer credentials
3619 will be verified, though this is a no-op for anonymous credentials.
3621 The @var{dir} parameter tells QEMU where to find the credential
3622 files. For server endpoints, this directory may contain a file
3623 @var{dh-params.pem} providing diffie-hellman parameters to use
3624 for the TLS server. If the file is missing, QEMU will generate
3625 a set of DH parameters at startup. This is a computationally
3626 expensive operation that consumes random pool entropy, so it is
3627 recommended that a persistent set of parameters be generated
3630 @item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
3632 Creates a TLS anonymous credentials object, which can be used to provide
3633 TLS support on network backends. The @option{id} parameter is a unique
3634 ID which network backends will use to access the credentials. The
3635 @option{endpoint} is either @option{server} or @option{client} depending
3636 on whether the QEMU network backend that uses the credentials will be
3637 acting as a client or as a server. If @option{verify-peer} is enabled
3638 (the default) then once the handshake is completed, the peer credentials
3639 will be verified. With x509 certificates, this implies that the clients
3640 must be provided with valid client certificates too.
3642 The @var{dir} parameter tells QEMU where to find the credential
3643 files. For server endpoints, this directory may contain a file
3644 @var{dh-params.pem} providing diffie-hellman parameters to use
3645 for the TLS server. If the file is missing, QEMU will generate
3646 a set of DH parameters at startup. This is a computationally
3647 expensive operation that consumes random pool entropy, so it is
3648 recommended that a persistent set of parameters be generated
3651 For x509 certificate credentials the directory will contain further files
3652 providing the x509 certificates. The certificates must be stored
3653 in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
3654 @var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
3655 @var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
3657 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}]
3659 Interval @var{t} can't be
0, this filter batches the packet delivery
: all
3660 packets arriving
in a given interval on netdev @
var{netdevid
} are delayed
3661 until the end of the interval
. Interval is
in microseconds
.
3663 queue @
var{all|rx|tx
} is an option that can be applied to any netfilter
.
3665 @option
{all
}: the filter is attached both to the receive and the transmit
3666 queue of the
netdev (default).
3668 @option
{rx
}: the filter is attached to the receive queue of the netdev
,
3669 where it will receive packets sent to the netdev
.
3671 @option
{tx
}: the filter is attached to the transmit queue of the netdev
,
3672 where it will receive packets sent by the netdev
.
3674 @item
-object filter
-dump
,id
=@
var{id
},netdev
=@
var{dev
},file
=@
var{filename
}][,maxlen
=@
var{len
}]
3676 Dump the network traffic on netdev @
var{dev
} to the file specified by
3677 @
var{filename
}. At most @
var{len
} bytes (64k by
default) per packet are stored
.
3678 The file format is libpcap
, so it can be analyzed with tools such as tcpdump
3686 HXCOMM This is the last statement
. Insert
new options before
this line
!