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 ? 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",
38 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
40 Select the emulated machine by @
var{name
}. Use @code
{-machine ?
} to list
41 available machines
. Supported machine properties are
:
43 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
44 This is used to enable an accelerator
. Depending on the target architecture
,
45 kvm
, xen
, or tcg can be available
. By
default, tcg is used
. If there is more
46 than one accelerator specified
, the next one is used
if the previous one fails
48 @item kernel_irqchip
=on|off
49 Enables
in-kernel irqchip support
for the chosen accelerator when available
.
53 HXCOMM Deprecated by
-machine
54 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
56 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
57 "-cpu cpu select CPU (-cpu ? for list)\n", QEMU_ARCH_ALL
)
59 @item
-cpu @
var{model
}
61 Select CPU
model (-cpu ?
for list and additional feature selection
)
64 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
65 "-smp n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
66 " set the number of CPUs to 'n' [default=1]\n"
67 " maxcpus= maximum number of total cpus, including\n"
68 " offline CPUs for hotplug, etc\n"
69 " cores= number of CPU cores on one socket\n"
70 " threads= number of threads on one CPU core\n"
71 " sockets= number of discrete sockets in the system\n",
74 @item
-smp @
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
76 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
77 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
79 For the PC target
, the number of @
var{cores
} per socket
, the number
80 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
81 specified
. Missing values will be computed
. If any on the three values is
82 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
83 specifies the maximum number of hotpluggable CPUs
.
86 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
87 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL
)
89 @item
-numa @
var{opts
}
91 Simulate a multi node NUMA system
. If mem and cpus are omitted
, resources
95 DEF("fda", HAS_ARG
, QEMU_OPTION_fda
,
96 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL
)
97 DEF("fdb", HAS_ARG
, QEMU_OPTION_fdb
, "", QEMU_ARCH_ALL
)
100 @item
-fdb @
var{file
}
103 Use @
var{file
} as floppy disk
0/1 image (@pxref
{disk_images
}). You can
104 use the host floppy by
using @file
{/dev
/fd0
} as
filename (@pxref
{host_drives
}).
107 DEF("hda", HAS_ARG
, QEMU_OPTION_hda
,
108 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL
)
109 DEF("hdb", HAS_ARG
, QEMU_OPTION_hdb
, "", QEMU_ARCH_ALL
)
110 DEF("hdc", HAS_ARG
, QEMU_OPTION_hdc
,
111 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL
)
112 DEF("hdd", HAS_ARG
, QEMU_OPTION_hdd
, "", QEMU_ARCH_ALL
)
114 @item
-hda @
var{file
}
115 @item
-hdb @
var{file
}
116 @item
-hdc @
var{file
}
117 @item
-hdd @
var{file
}
122 Use @
var{file
} as hard disk
0, 1, 2 or
3 image (@pxref
{disk_images
}).
125 DEF("cdrom", HAS_ARG
, QEMU_OPTION_cdrom
,
126 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
129 @item
-cdrom @
var{file
}
131 Use @
var{file
} as CD
-ROM
image (you cannot use @option
{-hdc
} and
132 @option
{-cdrom
} at the same time
). You can use the host CD
-ROM by
133 using @file
{/dev
/cdrom
} as
filename (@pxref
{host_drives
}).
136 DEF("drive", HAS_ARG
, QEMU_OPTION_drive
,
137 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
138 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
139 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
140 " [,serial=s][,addr=A][,id=name][,aio=threads|native]\n"
141 " [,readonly=on|off][,copy-on-read=on|off]\n"
142 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]][[,iops=i]|[[,iops_rd=r][,iops_wr=w]]\n"
143 " use 'file' as a drive image\n", QEMU_ARCH_ALL
)
145 @item
-drive @
var{option
}[,@
var{option
}[,@
var{option
}[,...]]]
148 Define a
new drive
. Valid options are
:
151 @item file
=@
var{file
}
152 This option defines which disk
image (@pxref
{disk_images
}) to use with
153 this drive
. If the filename contains comma
, you must double it
154 (for instance
, "file=my,,file" to use file
"my,file").
156 Special files such as iSCSI devices can be specified
using protocol
157 specific URLs
. See the section
for "Device URL Syntax" for more information
.
158 @item
if=@
var{interface}
159 This option defines on which type on
interface the drive is connected
.
160 Available types are
: ide
, scsi
, sd
, mtd
, floppy
, pflash
, virtio
.
161 @item bus
=@
var{bus
},unit
=@
var{unit
}
162 These options define where is connected the drive by defining the bus number and
164 @item index
=@
var{index
}
165 This option defines where is connected the drive by
using an index
in the list
166 of available connectors of a given
interface type
.
167 @item media
=@
var{media
}
168 This option defines the type of the media
: disk or cdrom
.
169 @item cyls
=@
var{c
},heads
=@
var{h
},secs
=@
var{s
}[,trans
=@
var{t
}]
170 These options have the same definition as they have
in @option
{-hdachs
}.
171 @item snapshot
=@
var{snapshot
}
172 @
var{snapshot
} is
"on" or
"off" and allows to enable snapshot
for given
drive (see @option
{-snapshot
}).
173 @item cache
=@
var{cache
}
174 @
var{cache
} is
"none", "writeback", "unsafe", "directsync" or
"writethrough" and controls how the host cache is used to access block data
.
176 @
var{aio
} is
"threads", or
"native" and selects between pthread based disk I
/O and native Linux AIO
.
177 @item format
=@
var{format
}
178 Specify which disk @
var{format
} will be used rather than detecting
179 the format
. Can be used to specifiy format
=raw to avoid interpreting
180 an untrusted format header
.
181 @item serial
=@
var{serial
}
182 This option specifies the serial number to assign to the device
.
183 @item addr
=@
var{addr
}
184 Specify the controller
's PCI address (if=virtio only).
185 @item werror=@var{action},rerror=@var{action}
186 Specify which @var{action} to take on write and read errors. Valid actions are:
187 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
188 "report" (report the error to the guest), "enospc" (pause QEMU only if the
189 host disk is full; report the error to the guest otherwise).
190 The default setting is @option{werror=enospc} and @option{rerror=report}.
192 Open drive @option{file} as read-only. Guest write attempts will fail.
193 @item copy-on-read=@var{copy-on-read}
194 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
195 file sectors into the image file.
198 By default, writethrough caching is used for all block device. This means that
199 the host page cache will be used to read and write data but write notification
200 will be sent to the guest only when the data has been reported as written by
201 the storage subsystem.
203 Writeback caching will report data writes as completed as soon as the data is
204 present in the host page cache. This is safe as long as you trust your host.
205 If your host crashes or loses power, then the guest may experience data
208 The host page cache can be avoided entirely with @option{cache=none}. This will
209 attempt to do disk IO directly to the guests memory. QEMU may still perform
210 an internal copy of the data.
212 The host page cache can be avoided while only sending write notifications to
213 the guest when the data has been reported as written by the storage subsystem
214 using @option{cache=directsync}.
216 Some block drivers perform badly with @option{cache=writethrough}, most notably,
217 qcow2. If performance is more important than correctness,
218 @option{cache=writeback} should be used with qcow2.
220 In case you don't care about data integrity over host failures
, use
221 cache
=unsafe
. This option tells qemu that it
never needs to write any data
222 to the disk but can instead keeps things
in cache
. If anything goes wrong
,
223 like your host losing power
, the disk storage getting disconnected accidentally
,
224 etc
. you
're image will most probably be rendered unusable. When using
225 the @option{-snapshot} option, unsafe caching is always used.
227 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
228 useful when the backing file is over a slow network. By default copy-on-read
231 Instead of @option{-cdrom} you can use:
233 qemu -drive file=file,index=2,media=cdrom
236 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
239 qemu -drive file=file,index=0,media=disk
240 qemu -drive file=file,index=1,media=disk
241 qemu -drive file=file,index=2,media=disk
242 qemu -drive file=file,index=3,media=disk
245 You can connect a CDROM to the slave of ide0:
247 qemu -drive file=file,if=ide,index=1,media=cdrom
250 If you don't specify the
"file=" argument
, you define an empty drive
:
252 qemu
-drive
if=ide
,index
=1,media
=cdrom
255 You can connect a SCSI disk with unit ID
6 on the bus #
0:
257 qemu
-drive file
=file
,if=scsi
,bus
=0,unit
=6
260 Instead of @option
{-fda
}, @option
{-fdb
}, you can use
:
262 qemu
-drive file
=file
,index
=0,if=floppy
263 qemu
-drive file
=file
,index
=1,if=floppy
266 By
default, @
var{interface} is
"ide" and @
var{index
} is automatically
269 qemu
-drive file
=a
-drive file
=b
"
277 DEF("set
", HAS_ARG, QEMU_OPTION_set,
278 "-set group
.id
.arg
=value
\n"
279 " set
<arg
> parameter
for item
<id
> of type
<group
>\n"
280 " i
.e
. -set drive
.$id
.file
=/path
/to
/image
\n", QEMU_ARCH_ALL)
287 DEF("global
", HAS_ARG, QEMU_OPTION_global,
288 "-global driver
.property
=value
\n"
289 " set a global
default for a driver property
\n",
297 DEF("mtdblock
", HAS_ARG, QEMU_OPTION_mtdblock,
298 "-mtdblock file use
'file' as on
-board Flash memory image
\n",
301 @item -mtdblock @var{file}
303 Use @var{file} as on-board Flash memory image.
306 DEF("sd
", HAS_ARG, QEMU_OPTION_sd,
307 "-sd file use
'file' as SecureDigital card image
\n", QEMU_ARCH_ALL)
311 Use @var{file} as SecureDigital card image.
314 DEF("pflash
", HAS_ARG, QEMU_OPTION_pflash,
315 "-pflash file use
'file' as a parallel flash image
\n", QEMU_ARCH_ALL)
317 @item -pflash @var{file}
319 Use @var{file} as a parallel flash image.
322 DEF("boot
", HAS_ARG, QEMU_OPTION_boot,
323 "-boot
[order
=drives
][,once
=drives
][,menu
=on|off
]\n"
324 " [,splash
=sp_name
][,splash
-time
=sp_time
]\n"
325 " 'drives': floppy (a
), hard
disk (c
), CD
-ROM (d
), network (n
)\n"
326 " 'sp_name': the file
's name that would be passed to bios as logo picture, if menu=on\n"
327 " 'sp_time
': the period that splash picture last if menu=on, unit is ms\n",
330 @item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}]
332 Specify boot order @var{drives} as a string of drive letters. Valid
333 drive letters depend on the target achitecture. The x86 PC uses: a, b
334 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
335 from network adapter 1-4), hard disk boot is the default. To apply a
336 particular boot order only on the first startup, specify it via
339 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
340 as firmware/BIOS supports them. The default is non-interactive boot.
342 A splash picture could be passed to bios, enabling user to show it as logo,
343 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
344 supports them. Currently Seabios for X86 system support it.
345 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
346 format(true color). The resolution should be supported by the SVGA mode, so
347 the recommended is 320x240, 640x480, 800x640.
350 # try to boot from network first, then from hard disk
352 # boot from CD-ROM first, switch back to default order after reboot
354 # boot with a splash picture for 5 seconds.
355 qemu -boot menu=on,splash=/root/boot.bmp,splash-time=5000
358 Note: The legacy format '-boot @
var{drives
}' is still supported but its
359 use is discouraged as it may be removed from future versions.
362 DEF("snapshot", 0, QEMU_OPTION_snapshot,
363 "-snapshot write to temporary files instead of disk image files\n",
368 Write to temporary files instead of disk image files. In this case,
369 the raw disk image you use is not written back. You can however force
370 the write back by pressing @key{C-a s} (@pxref{disk_images}).
373 DEF("m", HAS_ARG, QEMU_OPTION_m,
374 "-m megs set virtual RAM size to megs MB [default="
375 stringify(DEFAULT_RAM_SIZE) "]\n", QEMU_ARCH_ALL)
379 Set virtual RAM size to @var{megs} megabytes. Default is 128 MiB. Optionally,
380 a suffix of ``M'' or ``G'' can be used to signify a value in megabytes or
381 gigabytes respectively.
384 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
385 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
387 @item -mem-path @var{path}
388 Allocate guest RAM from a temporarily created file in @var{path}.
392 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
393 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
397 Preallocate memory when using -mem-path.
401 DEF("k", HAS_ARG, QEMU_OPTION_k,
402 "-k language use keyboard layout (for example 'fr
' for French)\n",
405 @item -k @var{language}
407 Use keyboard layout @var{language} (for example @code{fr} for
408 French). This option is only needed where it is not easy to get raw PC
409 keycodes (e.g. on Macs, with some X11 servers or with a VNC
410 display). You don't normally need to use it on PC
/Linux or PC
/Windows
413 The available layouts are
:
415 ar de
-ch es fo fr
-ca hu ja mk no pt
-br sv
416 da en
-gb et fr fr
-ch is lt nl pl ru th
417 de en
-us fi fr
-be hr it lv nl
-be pt sl tr
420 The
default is @code
{en
-us
}.
424 DEF("audio-help", 0, QEMU_OPTION_audio_help
,
425 "-audio-help print list of audio drivers and their options\n",
430 Will show the audio subsystem help
: list of drivers
, tunable
434 DEF("soundhw", HAS_ARG
, QEMU_OPTION_soundhw
,
435 "-soundhw c1,... enable audio support\n"
436 " and only specified sound cards (comma separated list)\n"
437 " use -soundhw ? to get the list of supported cards\n"
438 " use -soundhw all to enable all of them\n", QEMU_ARCH_ALL
)
440 @item
-soundhw @
var{card1
}[,@
var{card2
},...] or
-soundhw all
442 Enable audio and selected sound hardware
. Use ? to print all
443 available sound hardware
.
446 qemu
-soundhw sb16
,adlib disk
.img
447 qemu
-soundhw es1370 disk
.img
448 qemu
-soundhw ac97 disk
.img
449 qemu
-soundhw hda disk
.img
450 qemu
-soundhw all disk
.img
454 Note that Linux
's i810_audio OSS kernel (for AC97) module might
455 require manually specifying clocking.
458 modprobe i810_audio clocking=48000
462 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
463 "-balloon none disable balloon device\n"
464 "-balloon virtio[,addr=str]\n"
465 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
469 Disable balloon device.
470 @item -balloon virtio[,addr=@var{addr}]
471 Enable virtio balloon device (default), optionally with PCI address
479 DEF("usb", 0, QEMU_OPTION_usb,
480 "-usb enable the USB driver (will be the default soon)\n",
488 Enable the USB driver (will be the default soon)
491 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
492 "-usbdevice name add the host or guest USB device 'name
'\n",
496 @item -usbdevice @var{devname}
498 Add the USB device @var{devname}. @xref{usb_devices}.
503 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
506 Pointer device that uses absolute coordinates (like a touchscreen). This
507 means qemu is able to report the mouse position without having to grab the
508 mouse. Also overrides the PS/2 mouse emulation when activated.
510 @item disk:[format=@var{format}]:@var{file}
511 Mass storage device based on file. The optional @var{format} argument
512 will be used rather than detecting the format. Can be used to specifiy
513 @code{format=raw} to avoid interpreting an untrusted format header.
515 @item host:@var{bus}.@var{addr}
516 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
518 @item host:@var{vendor_id}:@var{product_id}
519 Pass through the host device identified by @var{vendor_id}:@var{product_id}
522 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
523 Serial converter to host character device @var{dev}, see @code{-serial} for the
527 Braille device. This will use BrlAPI to display the braille output on a real
530 @item net:@var{options}
531 Network adapter that supports CDC ethernet and RNDIS protocols.
536 DEF("device", HAS_ARG, QEMU_OPTION_device,
537 "-device driver[,prop[=value][,...]]\n"
538 " add device (based on driver)\n"
539 " prop=value,... sets driver properties\n"
540 " use -device ? to print all possible drivers\n"
541 " use -device driver,? to print all possible properties\n",
544 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
546 Add device @var{driver}. @var{prop}=@var{value} sets driver
547 properties. Valid properties depend on the driver. To get help on
548 possible drivers and properties, use @code{-device ?} and
549 @code{-device @var{driver},?}.
554 DEFHEADING(File system options:)
556 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
557 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped|passthrough|none}]\n"
558 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
563 @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}]
565 Define a new file system device. Valid options are:
568 This option specifies the fs driver backend to use.
569 Currently "local", "handle" and "proxy" file system drivers are supported.
571 Specifies identifier for this device
572 @item path=@var{path}
573 Specifies the export path for the file system device. Files under
574 this path will be available to the 9p client on the guest.
575 @item security_model=@var{security_model}
576 Specifies the security model to be used for this export path.
577 Supported security models are "passthrough", "mapped" and "none".
578 In "passthrough" security model, files are stored using the same
579 credentials as they are created on the guest. This requires qemu
580 to run as root. In "mapped" security model, some of the file
581 attributes like uid, gid, mode bits and link target are stored as
582 file attributes. Directories exported by this security model cannot
583 interact with other unix tools. "none" security model is same as
584 passthrough except the sever won't report failures
if it fails to
585 set file attributes like ownership
. Security model is mandatory
586 only
for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take
587 security model as a parameter.
588 @item writeout=@var{writeout}
589 This is an optional argument. The only supported value is "immediate".
590 This means that host page cache will be used to read and write data but
591 write notification will be sent to the guest only when the data has been
592 reported as written by the storage subsystem.
594 Enables exporting 9p share as a readonly mount for guests. By default
595 read-write access is given.
596 @item socket=@var{socket}
597 Enables proxy filesystem driver to use passed socket file for communicating
598 with virtfs-proxy-helper
599 @item sock_fd=@var{sock_fd}
600 Enables proxy filesystem driver to use passed socket descriptor for
601 communicating with virtfs-proxy-helper. Usually a helper like libvirt
602 will create socketpair and pass one of the fds as sock_fd
605 -fsdev option is used along with -device driver "virtio-9p-pci".
606 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
607 Options for virtio-9p-pci driver are:
610 Specifies the id value specified along with -fsdev option
611 @item mount_tag=@var{mount_tag}
612 Specifies the tag name to be used by the guest to mount this export point
619 DEFHEADING(Virtual File system pass-through options:)
621 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
622 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped|passthrough|none]\n"
623 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
628 @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}]
631 The general form of a Virtual File system pass-through options are:
634 This option specifies the fs driver backend to use.
635 Currently "local", "handle" and "proxy" file system drivers are supported.
637 Specifies identifier for this device
638 @item path=@var{path}
639 Specifies the export path for the file system device. Files under
640 this path will be available to the 9p client on the guest.
641 @item security_model=@var{security_model}
642 Specifies the security model to be used for this export path.
643 Supported security models are "passthrough", "mapped" and "none".
644 In "passthrough" security model, files are stored using the same
645 credentials as they are created on the guest. This requires qemu
646 to run as root. In "mapped" security model, some of the file
647 attributes like uid, gid, mode bits and link target are stored as
648 file attributes. Directories exported by this security model cannot
649 interact with other unix tools. "none" security model is same as
650 passthrough except the sever won't report failures
if it fails to
651 set file attributes like ownership
. Security model is mandatory only
652 for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take security
653 model as a parameter.
654 @item writeout=@var{writeout}
655 This is an optional argument. The only supported value is "immediate".
656 This means that host page cache will be used to read and write data but
657 write notification will be sent to the guest only when the data has been
658 reported as written by the storage subsystem.
660 Enables exporting 9p share as a readonly mount for guests. By default
661 read-write access is given.
662 @item socket=@var{socket}
663 Enables proxy filesystem driver to use passed socket file for
664 communicating with virtfs-proxy-helper. Usually a helper like libvirt
665 will create socketpair and pass one of the fds as sock_fd
667 Enables proxy filesystem driver to use passed 'sock_fd
' as the socket
668 descriptor for interfacing with virtfs-proxy-helper
672 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
673 "-virtfs_synth Create synthetic file system image\n",
677 @findex -virtfs_synth
678 Create synthetic file system image
683 DEF("name", HAS_ARG, QEMU_OPTION_name,
684 "-name string1[,process=string2]\n"
685 " set the name of the guest\n"
686 " string1 sets the window title and string2 the process name (on Linux)\n",
689 @item -name @var{name}
691 Sets the @var{name} of the guest.
692 This name will be displayed in the SDL window caption.
693 The @var{name} will also be used for the VNC server.
694 Also optionally set the top visible process name in Linux.
697 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
698 "-uuid %08x-%04x-%04x-%04x-%012x\n"
699 " specify machine UUID\n", QEMU_ARCH_ALL)
701 @item -uuid @var{uuid}
712 DEFHEADING(Display options:)
718 DEF("display", HAS_ARG, QEMU_OPTION_display,
719 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
720 " [,window_close=on|off]|curses|none|\n"
721 " vnc=<display>[,<optargs>]\n"
722 " select display type\n", QEMU_ARCH_ALL)
724 @item -display @var{type}
726 Select type of display to use. This option is a replacement for the
727 old style -sdl/-curses/... options. Valid values for @var{type} are
730 Display video output via SDL (usually in a separate graphics
731 window; see the SDL documentation for other possibilities).
733 Display video output via curses. For graphics device models which
734 support a text mode, QEMU can display this output using a
735 curses/ncurses interface. Nothing is displayed when the graphics
736 device is in graphical mode or if the graphics device does not support
737 a text mode. Generally only the VGA device models support text mode.
739 Do not display video output. The guest will still see an emulated
740 graphics card, but its output will not be displayed to the QEMU
741 user. This option differs from the -nographic option in that it
742 only affects what is done with video output; -nographic also changes
743 the destination of the serial and parallel port data.
745 Start a VNC server on display <arg>
749 DEF("nographic", 0, QEMU_OPTION_nographic,
750 "-nographic disable graphical output and redirect serial I/Os to console\n",
755 Normally, QEMU uses SDL to display the VGA output. With this option,
756 you can totally disable graphical output so that QEMU is a simple
757 command line application. The emulated serial port is redirected on
758 the console. Therefore, you can still use QEMU to debug a Linux kernel
759 with a serial console.
762 DEF("curses", 0, QEMU_OPTION_curses,
763 "-curses use a curses/ncurses interface instead of SDL\n",
768 Normally, QEMU uses SDL to display the VGA output. With this option,
769 QEMU can display the VGA output when in text mode using a
770 curses/ncurses interface. Nothing is displayed in graphical mode.
773 DEF("no-frame", 0, QEMU_OPTION_no_frame,
774 "-no-frame open SDL window without a frame and window decorations\n",
779 Do not use decorations for SDL windows and start them using the whole
780 available screen space. This makes the using QEMU in a dedicated desktop
781 workspace more convenient.
784 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
785 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
790 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
791 affects the special keys (for fullscreen, monitor-mode switching, etc).
794 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
795 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
800 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
801 affects the special keys (for fullscreen, monitor-mode switching, etc).
804 DEF("no-quit", 0, QEMU_OPTION_no_quit,
805 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
809 Disable SDL window close capability.
812 DEF("sdl", 0, QEMU_OPTION_sdl,
813 "-sdl enable SDL\n", QEMU_ARCH_ALL)
820 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
821 "-spice <args> enable spice\n", QEMU_ARCH_ALL)
823 @item -spice @var{option}[,@var{option}[,...]]
825 Enable the spice remote desktop protocol. Valid options are
830 Set the TCP port spice is listening on for plaintext channels.
833 Set the IP address spice is listening on. Default is any address.
837 Force using the specified IP version.
839 @item password=<secret>
840 Set the password you need to authenticate.
843 Require that the client use SASL to authenticate with the spice.
844 The exact choice of authentication method used is controlled from the
845 system / user's SASL configuration file
for the
'qemu' service
. This
846 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
847 unprivileged user
, an environment variable SASL_CONF_PATH can be used
848 to make it search alternate locations
for the service config
.
849 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
850 it is recommended that SASL always be combined with the
'tls' and
851 'x509' settings to enable use of SSL and server certificates
. This
852 ensures a data encryption preventing compromise of authentication
855 @item disable
-ticketing
856 Allow client connects without authentication
.
858 @item disable
-copy
-paste
859 Disable copy paste between the client and the guest
.
862 Set the TCP port spice is listening on
for encrypted channels
.
865 Set the x509 file directory
. Expects same filenames as
-vnc $display
,x509
=$dir
867 @item x509
-key
-file
=<file
>
868 @item x509
-key
-password
=<file
>
869 @item x509
-cert
-file
=<file
>
870 @item x509
-cacert
-file
=<file
>
871 @item x509
-dh
-key
-file
=<file
>
872 The x509 file names can also be configured individually
.
874 @item tls
-ciphers
=<list
>
875 Specify which ciphers to use
.
877 @item tls
-channel
=[main|display|cursor|inputs|record|playback
]
878 @item plaintext
-channel
=[main|display|cursor|inputs|record|playback
]
879 Force specific channel to be used with or without TLS encryption
. The
880 options can be specified multiple times to configure multiple
881 channels
. The special name
"default" can be used to set the
default
882 mode
. For channels which are not explicitly forced into one mode the
883 spice client is allowed to pick tls
/plaintext as he pleases
.
885 @item image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]
886 Configure image
compression (lossless
).
889 @item jpeg
-wan
-compression
=[auto|
never|always
]
890 @item zlib
-glz
-wan
-compression
=[auto|
never|always
]
891 Configure wan image
compression (lossy
for slow links
).
894 @item streaming
-video
=[off|all|filter
]
895 Configure video stream detection
. Default is filter
.
897 @item agent
-mouse
=[on|off
]
898 Enable
/disable passing mouse events via vdagent
. Default is on
.
900 @item playback
-compression
=[on|off
]
901 Enable
/disable audio stream
compression (using celt
0.5.1). Default is on
.
906 DEF("portrait", 0, QEMU_OPTION_portrait
,
907 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
912 Rotate graphical output
90 deg
left (only PXA LCD
).
915 DEF("rotate", HAS_ARG
, QEMU_OPTION_rotate
,
916 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
921 Rotate graphical output some deg
left (only PXA LCD
).
924 DEF("vga", HAS_ARG
, QEMU_OPTION_vga
,
925 "-vga [std|cirrus|vmware|qxl|xenfb|none]\n"
926 " select video card type\n", QEMU_ARCH_ALL
)
928 @item
-vga @
var{type
}
930 Select type of VGA card to emulate
. Valid values
for @
var{type
} are
933 Cirrus Logic GD5446 Video card
. All Windows versions starting from
934 Windows
95 should recognize and use
this graphic card
. For optimal
935 performances
, use
16 bit color depth
in the guest and the host OS
.
936 (This one is the
default)
938 Standard VGA card with Bochs VBE extensions
. If your guest OS
939 supports the VESA
2.0 VBE
extensions (e
.g
. Windows XP
) and
if you want
940 to use high resolution
modes (>= 1280x1024x16
) then you should use
943 VMWare SVGA
-II compatible adapter
. Use it
if you have sufficiently
944 recent XFree86
/XOrg server or Windows guest with a driver
for this
947 QXL paravirtual graphic card
. It is VGA
compatible (including VESA
948 2.0 VBE support
). Works best with qxl guest drivers installed though
.
949 Recommended choice when
using the spice protocol
.
955 DEF("full-screen", 0, QEMU_OPTION_full_screen
,
956 "-full-screen start in full screen\n", QEMU_ARCH_ALL
)
960 Start
in full screen
.
963 DEF("g", 1, QEMU_OPTION_g
,
964 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
965 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
967 @item
-g @
var{width
}x@
var{height
}[x@
var{depth
}]
969 Set the initial graphical resolution and
depth (PPC
, SPARC only
).
972 DEF("vnc", HAS_ARG
, QEMU_OPTION_vnc
,
973 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL
)
975 @item
-vnc @
var{display
}[,@
var{option
}[,@
var{option
}[,...]]]
977 Normally
, QEMU uses SDL to display the VGA output
. With
this option
,
978 you can have QEMU listen on VNC display @
var{display
} and redirect the VGA
979 display over the VNC session
. It is very useful to enable the usb
980 tablet device when
using this option (option @option
{-usbdevice
981 tablet
}). When
using the VNC display
, you must use the @option
{-k
}
982 parameter to set the keyboard layout
if you are not
using en
-us
. Valid
983 syntax
for the @
var{display
} is
987 @item @
var{host
}:@
var{d
}
989 TCP connections will only be allowed from @
var{host
} on display @
var{d
}.
990 By convention the TCP port is
5900+@
var{d
}. Optionally
, @
var{host
} can
991 be omitted
in which
case the server will accept connections from any host
.
993 @item unix
:@
var{path
}
995 Connections will be allowed over UNIX domain sockets where @
var{path
} is the
996 location of a unix socket to listen
for connections on
.
1000 VNC is initialized but not started
. The monitor @code
{change
} command
1001 can be used to later start the VNC server
.
1005 Following the @
var{display
} value there may be one or more @
var{option
} flags
1006 separated by commas
. Valid options are
1012 Connect to a listening VNC client via a ``reverse
'' connection
. The
1013 client is specified by the @
var{display
}. For reverse network
1014 connections (@
var{host
}:@
var{d
},@code
{reverse
}), the @
var{d
} argument
1015 is a TCP port number
, not a display number
.
1019 Require that password based authentication is used
for client connections
.
1020 The password must be set separately
using the @code
{change
} command
in the
1025 Require that client use TLS when communicating with the VNC server
. This
1026 uses anonymous TLS credentials so is susceptible to a man
-in-the
-middle
1027 attack
. It is recommended that
this option be combined with either the
1028 @option
{x509
} or @option
{x509verify
} options
.
1030 @item x509
=@
var{/path
/to
/certificate
/dir
}
1032 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1033 for negotiating the TLS session
. The server will send its x509 certificate
1034 to the client
. It is recommended that a password be set on the VNC server
1035 to provide authentication of the client when
this is used
. The path following
1036 this option specifies where the x509 certificates are to be loaded from
.
1037 See the @ref
{vnc_security
} section
for details on generating certificates
.
1039 @item x509verify
=@
var{/path
/to
/certificate
/dir
}
1041 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1042 for negotiating the TLS session
. The server will send its x509 certificate
1043 to the client
, and request that the client send its own x509 certificate
.
1044 The server will validate the client
's certificate against the CA certificate,
1045 and reject clients when validation fails. If the certificate authority is
1046 trusted, this is a sufficient authentication mechanism. You may still wish
1047 to set a password on the VNC server as a second authentication layer. The
1048 path following this option specifies where the x509 certificates are to
1049 be loaded from. See the @ref{vnc_security} section for details on generating
1054 Require that the client use SASL to authenticate with the VNC server.
1055 The exact choice of authentication method used is controlled from the
1056 system / user's SASL configuration file
for the
'qemu' service
. This
1057 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
1058 unprivileged user
, an environment variable SASL_CONF_PATH can be used
1059 to make it search alternate locations
for the service config
.
1060 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
1061 it is recommended that SASL always be combined with the
'tls' and
1062 'x509' settings to enable use of SSL and server certificates
. This
1063 ensures a data encryption preventing compromise of authentication
1064 credentials
. See the @ref
{vnc_security
} section
for details on
using
1065 SASL authentication
.
1069 Turn on access control lists
for checking of the x509 client certificate
1070 and SASL party
. For x509 certs
, the ACL check is made against the
1071 certificate
's distinguished name. This is something that looks like
1072 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1073 made against the username, which depending on the SASL plugin, may
1074 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1075 When the @option{acl} flag is set, the initial access list will be
1076 empty, with a @code{deny} policy. Thus no one will be allowed to
1077 use the VNC server until the ACLs have been loaded. This can be
1078 achieved using the @code{acl} monitor command.
1082 Enable lossy compression methods (gradient, JPEG, ...). If this
1083 option is set, VNC client may receive lossy framebuffer updates
1084 depending on its encoding settings. Enabling this option can save
1085 a lot of bandwidth at the expense of quality.
1089 Disable adaptive encodings. Adaptive encodings are enabled by default.
1090 An adaptive encoding will try to detect frequently updated screen regions,
1091 and send updates in these regions using a lossy encoding (like JPEG).
1092 This can be really helpful to save bandwidth when playing videos. Disabling
1093 adaptive encodings allows to restore the original static behavior of encodings
1103 ARCHHEADING(, QEMU_ARCH_I386)
1105 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1110 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1111 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1116 Use it when installing Windows 2000 to avoid a disk full bug. After
1117 Windows 2000 is installed, you no longer need this option (this option
1118 slows down the IDE transfers).
1121 HXCOMM Deprecated by -rtc
1122 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1124 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1125 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1128 @item -no-fd-bootchk
1129 @findex -no-fd-bootchk
1130 Disable boot signature checking for floppy disks in Bochs BIOS. It may
1131 be needed to boot from old floppy disks.
1132 TODO: check reference to Bochs BIOS.
1135 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1136 "-no-acpi disable ACPI\n", QEMU_ARCH_I386)
1140 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1141 it if your guest OS complains about ACPI problems (PC target machine
1145 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1146 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1150 Disable HPET support.
1153 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1154 "-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"
1155 " ACPI table description\n", QEMU_ARCH_I386)
1157 @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}]...]
1159 Add ACPI table with specified header fields and context from specified files.
1160 For file=, take whole ACPI table from the specified files, including all
1161 ACPI headers (possible overridden by other options).
1162 For data=, only data
1163 portion of the table is used, all header information is specified in the
1167 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1168 "-smbios file=binary\n"
1169 " load SMBIOS entry from binary file\n"
1170 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1171 " specify SMBIOS type 0 fields\n"
1172 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1173 " [,uuid=uuid][,sku=str][,family=str]\n"
1174 " specify SMBIOS type 1 fields\n", QEMU_ARCH_I386)
1176 @item -smbios file=@var{binary}
1178 Load SMBIOS entry from binary file.
1180 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}]
1182 Specify SMBIOS type 0 fields
1184 @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}]
1185 Specify SMBIOS type 1 fields
1193 DEFHEADING(Network options:)
1198 HXCOMM Legacy slirp options (now moved to -net user):
1200 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1201 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1202 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1204 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1208 DEF("net", HAS_ARG, QEMU_OPTION_net,
1209 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1210 " create a new Network Interface Card and connect it to VLAN 'n
'\n"
1212 "-net user[,vlan=n][,name=str][,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
1213 " [,hostname=host][,dhcpstart=addr][,dns=addr][,tftp=dir][,bootfile=f]\n"
1214 " [,hostfwd=rule][,guestfwd=rule]"
1216 "[,smb=dir[,smbserver=addr]]\n"
1218 " connect the user mode network stack to VLAN 'n
', configure its\n"
1219 " DHCP server and enabled optional services\n"
1222 "-net tap[,vlan=n][,name=str],ifname=name\n"
1223 " connect the host TAP network interface to VLAN 'n
'\n"
1225 "-net tap[,vlan=n][,name=str][,fd=h][,ifname=name][,script=file][,downscript=dfile][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off][,vhostfd=h][,vhostforce=on|off]\n"
1226 " connect the host TAP network interface to VLAN 'n
' and use the\n"
1227 " network scripts 'file
' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1228 " and 'dfile
' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1229 " use '[down
]script
=no
' to disable script execution\n"
1230 " use 'fd
=h
' to connect to an already opened TAP interface\n"
1231 " use 'sndbuf
=nbytes
' to limit the size of the send buffer (the\n"
1232 " default is disabled 'sndbuf
=0' to enable flow control set 'sndbuf
=1048576')\n"
1233 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1234 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1235 " use vhost=on to enable experimental in kernel accelerator\n"
1236 " (only has effect for virtio guests which use MSIX)\n"
1237 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1238 " use 'vhostfd
=h
' to connect to an already opened vhost net device\n"
1240 "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
1241 " connect the vlan 'n
' to another VLAN using a socket connection\n"
1242 "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1243 " connect the vlan 'n
' to multicast maddr and port\n"
1244 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1245 "-net socket[,vlan=n][,name=str][,fd=h][,udp=host:port][,localaddr=host:port]\n"
1246 " connect the vlan 'n
' to another VLAN using an UDP tunnel\n"
1248 "-net vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1249 " connect the vlan 'n
' to port 'n
' of a vde switch running\n"
1250 " on host and listening for incoming connections on 'socketpath
'.\n"
1251 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1252 " ownership and permissions for communication port.\n"
1254 "-net dump[,vlan=n][,file=f][,len=n]\n"
1255 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
1256 "-net none use it alone to have zero network devices. If no -net option\n"
1257 " is provided, the default is '-net nic
-net user
'\n", QEMU_ARCH_ALL)
1258 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1267 "socket],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
1269 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1271 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1272 = 0 is the default). The NIC is an e1000 by default on the PC
1273 target. Optionally, the MAC address can be changed to @var{mac}, the
1274 device address set to @var{addr} (PCI cards only),
1275 and a @var{name} can be assigned for use in monitor commands.
1276 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1277 that the card should have; this option currently only affects virtio cards; set
1278 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1279 NIC is created. Qemu can emulate several different models of network card.
1280 Valid values for @var{type} are
1281 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1282 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1283 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1284 Not all devices are supported on all targets. Use -net nic,model=?
1285 for a list of available devices for your target.
1287 @item -net user[,@var{option}][,@var{option}][,...]
1288 Use the user mode network stack which requires no administrator
1289 privilege to run. Valid options are:
1293 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1295 @item name=@var{name}
1296 Assign symbolic name for use in monitor commands.
1298 @item net=@var{addr}[/@var{mask}]
1299 Set IP network address the guest will see. Optionally specify the netmask,
1300 either in the form a.b.c.d or as number of valid top-most bits. Default is
1303 @item host=@var{addr}
1304 Specify the guest-visible address of the host. Default is the 2nd IP in the
1305 guest network, i.e. x.x.x.2.
1307 @item restrict=on|off
1308 If this option is enabled, the guest will be isolated, i.e. it will not be
1309 able to contact the host and no guest IP packets will be routed over the host
1310 to the outside. This option does not affect any explicitly set forwarding rules.
1312 @item hostname=@var{name}
1313 Specifies the client hostname reported by the builtin DHCP server.
1315 @item dhcpstart=@var{addr}
1316 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1317 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1319 @item dns=@var{addr}
1320 Specify the guest-visible address of the virtual nameserver. The address must
1321 be different from the host address. Default is the 3rd IP in the guest network,
1324 @item tftp=@var{dir}
1325 When using the user mode network stack, activate a built-in TFTP
1326 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1327 The TFTP client on the guest must be configured in binary mode (use the command
1328 @code{bin} of the Unix TFTP client).
1330 @item bootfile=@var{file}
1331 When using the user mode network stack, broadcast @var{file} as the BOOTP
1332 filename. In conjunction with @option{tftp}, this can be used to network boot
1333 a guest from a local directory.
1335 Example (using pxelinux):
1337 qemu -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1340 @item smb=@var{dir}[,smbserver=@var{addr}]
1341 When using the user mode network stack, activate a built-in SMB
1342 server so that Windows OSes can access to the host files in @file{@var{dir}}
1343 transparently. The IP address of the SMB server can be set to @var{addr}. By
1344 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1346 In the guest Windows OS, the line:
1350 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1351 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1353 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1355 Note that a SAMBA server must be installed on the host OS.
1356 QEMU was tested successfully with smbd versions from Red Hat 9,
1357 Fedora Core 3 and OpenSUSE 11.x.
1359 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1360 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1361 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1362 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1363 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1364 be bound to a specific host interface. If no connection type is set, TCP is
1365 used. This option can be given multiple times.
1367 For example, to redirect host X11 connection from screen 1 to guest
1368 screen 0, use the following:
1372 qemu -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1373 # this host xterm should open in the guest X11 server
1377 To redirect telnet connections from host port 5555 to telnet port on
1378 the guest, use the following:
1382 qemu -net user,hostfwd=tcp::5555-:23 [...]
1383 telnet localhost 5555
1386 Then when you use on the host @code{telnet localhost 5555}, you
1387 connect to the guest telnet server.
1389 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1390 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1391 to the character device @var{dev}. This option can be given multiple times.
1395 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1396 processed and applied to -net user. Mixing them with the new configuration
1397 syntax gives undefined results. Their use for new applications is discouraged
1398 as they will be removed from future versions.
1400 @item -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}] [,script=@var{file}][,downscript=@var{dfile}]
1401 Connect the host TAP network interface @var{name} to VLAN @var{n}, use
1402 the network script @var{file} to configure it and the network script
1403 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1404 automatically provides one. @option{fd}=@var{h} can be used to specify
1405 the handle of an already opened host TAP interface. The default network
1406 configure script is @file{/etc/qemu-ifup} and the default network
1407 deconfigure script is @file{/etc/qemu-ifdown}. Use @option{script=no}
1408 or @option{downscript=no} to disable script execution. Example:
1411 qemu linux.img -net nic -net tap
1414 More complicated example (two NICs, each one connected to a TAP device)
1416 qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1417 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1420 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1422 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1423 machine using a TCP socket connection. If @option{listen} is
1424 specified, QEMU waits for incoming connections on @var{port}
1425 (@var{host} is optional). @option{connect} is used to connect to
1426 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1427 specifies an already opened TCP socket.
1431 # launch a first QEMU instance
1432 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
1433 -net socket,listen=:1234
1434 # connect the VLAN 0 of this instance to the VLAN 0
1435 # of the first instance
1436 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
1437 -net socket,connect=127.0.0.1:1234
1440 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1442 Create a VLAN @var{n} shared with another QEMU virtual
1443 machines using a UDP multicast socket, effectively making a bus for
1444 every QEMU with same multicast address @var{maddr} and @var{port}.
1448 Several QEMU can be running on different hosts and share same bus (assuming
1449 correct multicast setup for these hosts).
1451 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1452 @url{http://user-mode-linux.sf.net}.
1454 Use @option{fd=h} to specify an already opened UDP multicast socket.
1459 # launch one QEMU instance
1460 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
1461 -net socket,mcast=230.0.0.1:1234
1462 # launch another QEMU instance on same "bus"
1463 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
1464 -net socket,mcast=230.0.0.1:1234
1465 # launch yet another QEMU instance on same "bus"
1466 qemu linux.img -net nic,macaddr=52:54:00:12:34:58 \
1467 -net socket,mcast=230.0.0.1:1234
1470 Example (User Mode Linux compat.):
1472 # launch QEMU instance (note mcast address selected
1474 qemu linux
.img
-net nic
,macaddr
=52:54:00:12:34:56 \
1475 -net socket
,mcast
=239.192.168.1:1102
1477 /path
/to
/linux ubd0
=/path
/to
/root_fs eth0
=mcast
1480 Example (send packets from host
's 1.2.3.4):
1482 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
1483 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
1486 @item -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
1487 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
1488 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
1489 and MODE @var{octalmode} to change default ownership and permissions for
1490 communication port. This option is only available if QEMU has been compiled
1491 with vde support enabled.
1496 vde_switch -F -sock /tmp/myswitch
1497 # launch QEMU instance
1498 qemu linux.img -net nic -net vde,sock=/tmp/myswitch
1501 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
1502 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
1503 At most @var{len} bytes (64k by default) per packet are stored. The file format is
1504 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
1507 Indicate that no network devices should be configured. It is used to
1508 override the default configuration (@option{-net nic -net user}) which
1509 is activated if no @option{-net} options are provided.
1516 DEFHEADING(Character device options:)
1518 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
1519 "-chardev null,id=id[,mux=on|off]\n"
1520 "-chardev socket,id=id[,host=host],port=host[,to=to][,ipv4][,ipv6][,nodelay]\n"
1521 " [,server][,nowait][,telnet][,mux=on|off] (tcp)\n"
1522 "-chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix)\n"
1523 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
1524 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
1525 "-chardev msmouse,id=id[,mux=on|off]\n"
1526 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
1528 "-chardev file,id=id,path=path[,mux=on|off]\n"
1529 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
1531 "-chardev console,id=id[,mux=on|off]\n"
1532 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1534 "-chardev pty,id=id[,mux=on|off]\n"
1535 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
1537 #ifdef CONFIG_BRLAPI
1538 "-chardev braille,id=id[,mux=on|off]\n"
1540 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
1541 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
1542 "-chardev tty,id=id,path=path[,mux=on|off]\n"
1544 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
1545 "-chardev parport,id=id,path=path[,mux=on|off]\n"
1547 #if defined(CONFIG_SPICE)
1548 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
1555 The general form of a character device option is:
1558 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
1576 The specific backend will determine the applicable options.
1578 All devices must have an id, which can be any string up to 127 characters long.
1579 It is used to uniquely identify this device in other command line directives.
1581 A character device may be used in multiplexing mode by multiple front-ends.
1582 The key sequence of @key{Control-a} and @key{c} will rotate the input focus
1583 between attached front-ends. Specify @option{mux=on} to enable this mode.
1585 Options to each backend are described below.
1587 @item -chardev null ,id=@var{id}
1588 A void device. This device will not emit any data, and will drop any data it
1589 receives. The null backend does not take any options.
1591 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet]
1593 Create a two-way stream socket, which can be either a TCP or a unix socket. A
1594 unix socket will be created if @option{path} is specified. Behaviour is
1595 undefined if TCP options are specified for a unix socket.
1597 @option{server} specifies that the socket shall be a listening socket.
1599 @option{nowait} specifies that QEMU should not block waiting for a client to
1600 connect to a listening socket.
1602 @option{telnet} specifies that traffic on the socket should interpret telnet
1605 TCP and unix socket options are given below:
1609 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
1611 @option{host} for a listening socket specifies the local address to be bound.
1612 For a connecting socket species the remote host to connect to. @option{host} is
1613 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
1615 @option{port} for a listening socket specifies the local port to be bound. For a
1616 connecting socket specifies the port on the remote host to connect to.
1617 @option{port} can be given as either a port number or a service name.
1618 @option{port} is required.
1620 @option{to} is only relevant to listening sockets. If it is specified, and
1621 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
1622 to and including @option{to} until it succeeds. @option{to} must be specified
1625 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1626 If neither is specified the socket may use either protocol.
1628 @option{nodelay} disables the Nagle algorithm.
1630 @item unix options: path=@var{path}
1632 @option{path} specifies the local path of the unix socket. @option{path} is
1637 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
1639 Sends all traffic from the guest to a remote host over UDP.
1641 @option{host} specifies the remote host to connect to. If not specified it
1642 defaults to @code{localhost}.
1644 @option{port} specifies the port on the remote host to connect to. @option{port}
1647 @option{localaddr} specifies the local address to bind to. If not specified it
1648 defaults to @code{0.0.0.0}.
1650 @option{localport} specifies the local port to bind to. If not specified any
1651 available local port will be used.
1653 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1654 If neither is specified the device may use either protocol.
1656 @item -chardev msmouse ,id=@var{id}
1658 Forward QEMU's emulated msmouse events to the guest
. @option
{msmouse
} does not
1661 @item
-chardev vc
,id
=@
var{id
} [[,width
=@
var{width
}] [,height
=@
var{height
}]] [[,cols
=@
var{cols
}] [,rows
=@
var{rows
}]]
1663 Connect to a QEMU text console
. @option
{vc
} may optionally be given a specific
1666 @option
{width
} and @option
{height
} specify the width and height respectively of
1667 the console
, in pixels
.
1669 @option
{cols
} and @option
{rows
} specify that the console be sized to fit a text
1670 console with the given dimensions
.
1672 @item
-chardev file
,id
=@
var{id
} ,path
=@
var{path
}
1674 Log all traffic received from the guest to a file
.
1676 @option
{path
} specifies the path of the file to be opened
. This file will be
1677 created
if it does not already exist
, and overwritten
if it does
. @option
{path
}
1680 @item
-chardev pipe
,id
=@
var{id
} ,path
=@
var{path
}
1682 Create a two
-way connection to the guest
. The behaviour differs slightly between
1683 Windows hosts and other hosts
:
1685 On Windows
, a single duplex pipe will be created at
1686 @file
{\\.pipe\@option
{path
}}.
1688 On other hosts
, 2 pipes will be created called @file
{@option
{path
}.in} and
1689 @file
{@option
{path
}.out
}. Data written to @file
{@option
{path
}.in} will be
1690 received by the guest
. Data written by the guest can be read from
1691 @file
{@option
{path
}.out
}. QEMU will not create these fifos
, and requires them to
1694 @option
{path
} forms part of the pipe path as described above
. @option
{path
} is
1697 @item
-chardev console
,id
=@
var{id
}
1699 Send traffic from the guest to QEMU
's standard output. @option{console} does not
1702 @option{console} is only available on Windows hosts.
1704 @item -chardev serial ,id=@var{id} ,path=@option{path}
1706 Send traffic from the guest to a serial device on the host.
1709 only available on Windows hosts.
1711 @option{path} specifies the name of the serial device to open.
1713 @item -chardev pty ,id=@var{id}
1715 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
1716 not take any options.
1718 @option{pty} is not available on Windows hosts.
1720 @item -chardev stdio ,id=@var{id} [,signal=on|off]
1721 Connect to standard input and standard output of the qemu process.
1723 @option{signal} controls if signals are enabled on the terminal, that includes
1724 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
1725 default, use @option{signal=off} to disable it.
1727 @option{stdio} is not available on Windows hosts.
1729 @item -chardev braille ,id=@var{id}
1731 Connect to a local BrlAPI server. @option{braille} does not take any options.
1733 @item -chardev tty ,id=@var{id} ,path=@var{path}
1735 Connect to a local tty device.
1737 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
1740 @option{path} specifies the path to the tty. @option{path} is required.
1742 @item -chardev parport ,id=@var{id} ,path=@var{path}
1744 @option{parport} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
1746 Connect to a local parallel port.
1748 @option{path} specifies the path to the parallel port device. @option{path} is
1751 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
1753 @option{spicevmc} is only available when spice support is built in.
1755 @option{debug} debug level for spicevmc
1757 @option{name} name of spice channel to connect to
1759 Connect to a spice virtual machine channel, such as vdiport.
1767 DEFHEADING(Device URL Syntax:)
1769 In addition to using normal file images for the emulated storage devices,
1770 QEMU can also use networked resources such as iSCSI devices. These are
1771 specified using a special URL syntax.
1775 iSCSI support allows QEMU to access iSCSI resources directly and use as
1776 images for the guest storage. Both disk and cdrom images are supported.
1778 Syntax for specifying iSCSI LUNs is
1779 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
1781 Example (without authentication):
1783 qemu -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
1784 --drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
1787 Example (CHAP username/password via URL):
1789 qemu --drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
1792 Example (CHAP username/password via environment variables):
1794 LIBISCSI_CHAP_USERNAME="user" \
1795 LIBISCSI_CHAP_PASSWORD="password" \
1796 qemu --drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
1799 iSCSI support is an optional feature of QEMU and only available when
1800 compiled and linked against libiscsi.
1803 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
1804 as Unix Domain Sockets.
1806 Syntax for specifying a NBD device using TCP
1807 ``nbd:<server-ip>:<port>[:exportname=<export>]''
1809 Syntax for specifying a NBD device using Unix Domain Sockets
1810 ``nbd:unix:<domain-socket>[:exportname=<export>]''
1815 qemu --drive file=nbd:192.0.2.1:30000
1818 Example for Unix Domain Sockets
1820 qemu --drive file=nbd:unix:/tmp/nbd-socket
1824 Sheepdog is a distributed storage system for QEMU.
1825 QEMU supports using either local sheepdog devices or remote networked
1828 Syntax for specifying a sheepdog device
1830 ``sheepdog:<vdiname>''
1832 ``sheepdog:<vdiname>:<snapid>''
1834 ``sheepdog:<vdiname>:<tag>''
1836 ``sheepdog:<host>:<port>:<vdiname>''
1838 ``sheepdog:<host>:<port>:<vdiname>:<snapid>''
1840 ``sheepdog:<host>:<port>:<vdiname>:<tag>''
1845 qemu --drive file=sheepdog:192.0.2.1:30000:MyVirtualMachine
1848 See also @url{http://http://www.osrg.net/sheepdog/}.
1853 DEFHEADING(Bluetooth(R) options:)
1855 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
1856 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands
\n" \
1857 "-bt hci
,host
[:id
]\n" \
1858 " use host
's HCI with the given name\n" \
1859 "-bt hci[,vlan=n]\n" \
1860 " emulate a standard HCI in virtual scatternet 'n
'\n" \
1861 "-bt vhci[,vlan=n]\n" \
1862 " add host computer to virtual scatternet 'n
' using VHCI\n" \
1863 "-bt device:dev[,vlan=n]\n" \
1864 " emulate a bluetooth device 'dev
' in scatternet 'n
'\n",
1871 Defines the function of the corresponding Bluetooth HCI. -bt options
1872 are matched with the HCIs present in the chosen machine type. For
1873 example when emulating a machine with only one HCI built into it, only
1874 the first @code{-bt hci[...]} option is valid and defines the HCI's
1875 logic
. The Transport Layer is decided by the machine type
. Currently
1876 the machines @code
{n800
} and @code
{n810
} have one HCI and all other
1880 The following three types are recognized
:
1884 (default) The corresponding Bluetooth HCI assumes no internal logic
1885 and will not respond to any HCI commands or emit events
.
1887 @item
-bt hci
,host
[:@
var{id
}]
1888 (@code
{bluez
} only
) The corresponding HCI passes commands
/ events
1889 to
/ from the physical HCI identified by the name @
var{id
} (default:
1890 @code
{hci0
}) on the computer running QEMU
. Only available on @code
{bluez
}
1891 capable systems like Linux
.
1893 @item
-bt hci
[,vlan
=@
var{n
}]
1894 Add a virtual
, standard HCI that will participate
in the Bluetooth
1895 scatternet @
var{n
} (default @code
{0}). Similarly to @option
{-net
}
1896 VLANs
, devices inside a bluetooth network @
var{n
} can only communicate
1897 with other devices
in the same
network (scatternet
).
1900 @item
-bt vhci
[,vlan
=@
var{n
}]
1901 (Linux
-host only
) Create a HCI
in scatternet @
var{n
} (default 0) attached
1902 to the host bluetooth stack instead of to the emulated target
. This
1903 allows the host and target machines to participate
in a common scatternet
1904 and communicate
. Requires the Linux @code
{vhci
} driver installed
. Can
1905 be used as following
:
1908 qemu
[...OPTIONS
...] -bt hci
,vlan
=5 -bt vhci
,vlan
=5
1911 @item
-bt device
:@
var{dev
}[,vlan
=@
var{n
}]
1912 Emulate a bluetooth device @
var{dev
} and place it
in network @
var{n
}
1913 (default @code
{0}). QEMU can only emulate one type of bluetooth devices
1918 Virtual wireless keyboard implementing the HIDP bluetooth profile
.
1925 DEFHEADING(Linux
/Multiboot boot specific
:)
1928 When
using these options
, you can use a given Linux or Multiboot
1929 kernel without installing it
in the disk image
. It can be useful
1930 for easier testing of various kernels
.
1935 DEF("kernel", HAS_ARG
, QEMU_OPTION_kernel
, \
1936 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL
)
1938 @item
-kernel @
var{bzImage
}
1940 Use @
var{bzImage
} as kernel image
. The kernel can be either a Linux kernel
1941 or
in multiboot format
.
1944 DEF("append", HAS_ARG
, QEMU_OPTION_append
, \
1945 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL
)
1947 @item
-append @
var{cmdline
}
1949 Use @
var{cmdline
} as kernel command line
1952 DEF("initrd", HAS_ARG
, QEMU_OPTION_initrd
, \
1953 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL
)
1955 @item
-initrd @
var{file
}
1957 Use @
var{file
} as initial ram disk
.
1959 @item
-initrd
"@var{file1} arg=foo,@var{file2}"
1961 This syntax is only available with multiboot
.
1963 Use @
var{file1
} and @
var{file2
} as modules and pass arg
=foo as parameter to the
1973 DEFHEADING(Debug
/Expert options
:)
1979 DEF("serial", HAS_ARG
, QEMU_OPTION_serial
, \
1980 "-serial dev redirect the serial port to char device 'dev'\n",
1983 @item
-serial @
var{dev
}
1985 Redirect the virtual serial port to host character device
1986 @
var{dev
}. The
default device is @code
{vc
} in graphical mode and
1987 @code
{stdio
} in non graphical mode
.
1989 This option can be used several times to simulate up to
4 serial
1992 Use @code
{-serial none
} to disable all serial ports
.
1994 Available character devices are
:
1996 @item vc
[:@
var{W
}x@
var{H
}]
1997 Virtual console
. Optionally
, a width and height can be given
in pixel with
2001 It is also possible to specify width or height
in characters
:
2006 [Linux only
] Pseudo
TTY (a
new PTY is automatically allocated
)
2008 No device is allocated
.
2012 [Linux only
] Use host tty
, e
.g
. @file
{/dev
/ttyS0
}. The host serial port
2013 parameters are set according to the emulated ones
.
2014 @item
/dev
/parport@
var{N
}
2015 [Linux only
, parallel port only
] Use host parallel port
2016 @
var{N
}. Currently SPP and EPP parallel port features can be used
.
2017 @item file
:@
var{filename
}
2018 Write output to @
var{filename
}. No character can be read
.
2020 [Unix only
] standard input
/output
2021 @item pipe
:@
var{filename
}
2022 name pipe @
var{filename
}
2024 [Windows only
] Use host serial port @
var{n
}
2025 @item udp
:[@
var{remote_host
}]:@
var{remote_port
}[@@
[@
var{src_ip
}]:@
var{src_port
}]
2026 This
implements UDP Net Console
.
2027 When @
var{remote_host
} or @
var{src_ip
} are not specified
2028 they
default to @code
{0.0.0.0}.
2029 When not
using a specified @
var{src_port
} a random port is automatically chosen
.
2031 If you just want a simple readonly console you can use @code
{netcat
} or
2032 @code
{nc
}, by starting qemu with
: @code
{-serial udp
::4555} and nc as
:
2033 @code
{nc
-u
-l
-p
4555}. Any time qemu writes something to that port it
2034 will appear
in the netconsole session
.
2036 If you plan to send characters back via netconsole or you want to stop
2037 and start qemu a lot of times
, you should have qemu use the same
2038 source port each time by
using something like @code
{-serial
2039 udp
::4555@@
:4556} to qemu
. Another approach is to use a patched
2040 version of netcat which can listen to a TCP port and send and receive
2041 characters via udp
. If you have a patched version of netcat which
2042 activates telnet remote echo and single char transfer
, then you can
2043 use the following options to step up a netcat redirector to allow
2044 telnet on port
5555 to access the qemu port
.
2047 -serial udp
::4555@@
:4556
2048 @item netcat options
:
2049 -u
-P
4555 -L
0.0.0.0:4556 -t
-p
5555 -I
-T
2050 @item telnet options
:
2054 @item tcp
:[@
var{host
}]:@
var{port
}[,@
var{server
}][,nowait
][,nodelay
]
2055 The TCP Net Console has two modes of operation
. It can send the serial
2056 I
/O to a location or wait
for a connection from a location
. By
default
2057 the TCP Net Console is sent to @
var{host
} at the @
var{port
}. If you use
2058 the @
var{server
} option QEMU will wait
for a client socket application
2059 to connect to the port before continuing
, unless the @code
{nowait
}
2060 option was specified
. The @code
{nodelay
} option disables the Nagle buffering
2061 algorithm
. If @
var{host
} is omitted
, 0.0.0.0 is assumed
. Only
2062 one TCP connection at a time is accepted
. You can use @code
{telnet
} to
2063 connect to the corresponding character device
.
2065 @item Example to send tcp console to
192.168.0.2 port
4444
2066 -serial tcp
:192.168.0.2:4444
2067 @item Example to listen and wait on port
4444 for connection
2068 -serial tcp
::4444,server
2069 @item Example to not wait and listen on ip
192.168.0.100 port
4444
2070 -serial tcp
:192.168.0.100:4444,server
,nowait
2073 @item telnet
:@
var{host
}:@
var{port
}[,server
][,nowait
][,nodelay
]
2074 The telnet protocol is used instead of raw tcp sockets
. The options
2075 work the same as
if you had specified @code
{-serial tcp
}. The
2076 difference is that the port acts like a telnet server or client
using
2077 telnet option negotiation
. This will also allow you to send the
2078 MAGIC_SYSRQ sequence
if you use a telnet that supports sending the
break
2079 sequence
. Typically
in unix telnet you
do it with Control
-] and then
2080 type
"send break" followed by pressing the enter key
.
2082 @item unix
:@
var{path
}[,server
][,nowait
]
2083 A unix domain socket is used instead of a tcp socket
. The option works the
2084 same as
if you had specified @code
{-serial tcp
} except the unix domain socket
2085 @
var{path
} is used
for connections
.
2087 @item mon
:@
var{dev_string
}
2088 This is a special option to allow the monitor to be multiplexed onto
2089 another serial port
. The monitor is accessed with key sequence of
2090 @key
{Control
-a
} and then pressing @key
{c
}. See monitor access
2091 @ref
{pcsys_keys
} in the
-nographic section
for more keys
.
2092 @
var{dev_string
} should be any one of the serial devices specified
2093 above
. An example to multiplex the monitor onto a telnet server
2094 listening on port
4444 would be
:
2096 @item
-serial mon
:telnet
::4444,server
,nowait
2100 Braille device
. This will use BrlAPI to display the braille output on a real
2104 Three button serial mouse
. Configure the guest to use Microsoft protocol
.
2108 DEF("parallel", HAS_ARG
, QEMU_OPTION_parallel
, \
2109 "-parallel dev redirect the parallel port to char device 'dev'\n",
2112 @item
-parallel @
var{dev
}
2114 Redirect the virtual parallel port to host device @
var{dev
} (same
2115 devices as the serial port
). On Linux hosts
, @file
{/dev
/parportN
} can
2116 be used to use hardware devices connected on the corresponding host
2119 This option can be used several times to simulate up to
3 parallel
2122 Use @code
{-parallel none
} to disable all parallel ports
.
2125 DEF("monitor", HAS_ARG
, QEMU_OPTION_monitor
, \
2126 "-monitor dev redirect the monitor to char device 'dev'\n",
2129 @item
-monitor @
var{dev
}
2131 Redirect the monitor to host device @
var{dev
} (same devices as the
2133 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2136 DEF("qmp", HAS_ARG
, QEMU_OPTION_qmp
, \
2137 "-qmp dev like -monitor but opens in 'control' mode\n",
2140 @item
-qmp @
var{dev
}
2142 Like
-monitor but opens
in 'control' mode
.
2145 DEF("mon", HAS_ARG
, QEMU_OPTION_mon
, \
2146 "-mon chardev=[name][,mode=readline|control][,default]\n", QEMU_ARCH_ALL
)
2148 @item
-mon chardev
=[name
][,mode
=readline|control
][,default]
2150 Setup monitor on chardev @
var{name
}.
2153 DEF("debugcon", HAS_ARG
, QEMU_OPTION_debugcon
, \
2154 "-debugcon dev redirect the debug console to char device 'dev'\n",
2157 @item
-debugcon @
var{dev
}
2159 Redirect the debug console to host device @
var{dev
} (same devices as the
2160 serial port
). The debug console is an I
/O port which is typically port
2161 0xe9; writing to that I
/O port sends output to
this device
.
2162 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2166 DEF("pidfile", HAS_ARG
, QEMU_OPTION_pidfile
, \
2167 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL
)
2169 @item
-pidfile @
var{file
}
2171 Store the QEMU process PID
in @
var{file
}. It is useful
if you launch QEMU
2175 DEF("singlestep", 0, QEMU_OPTION_singlestep
, \
2176 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL
)
2180 Run the emulation
in single step mode
.
2183 DEF("S", 0, QEMU_OPTION_S
, \
2184 "-S freeze CPU at startup (use 'c' to start execution)\n",
2189 Do not start CPU at
startup (you must type
'c' in the monitor
).
2192 DEF("gdb", HAS_ARG
, QEMU_OPTION_gdb
, \
2193 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL
)
2195 @item
-gdb @
var{dev
}
2197 Wait
for gdb connection on device @
var{dev
} (@pxref
{gdb_usage
}). Typical
2198 connections will likely be TCP
-based
, but also UDP
, pseudo TTY
, or even
2199 stdio are reasonable use
case. The latter is allowing to start qemu from
2200 within gdb and establish the connection via a pipe
:
2202 (gdb
) target remote | exec qemu
-gdb stdio
...
2206 DEF("s", 0, QEMU_OPTION_s
, \
2207 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT
"\n",
2212 Shorthand
for -gdb tcp
::1234, i
.e
. open a gdbserver on TCP port
1234
2213 (@pxref
{gdb_usage
}).
2216 DEF("d", HAS_ARG
, QEMU_OPTION_d
, \
2217 "-d item1,... output log to /tmp/qemu.log (use -d ? for a list of log items)\n",
2222 Output log
in /tmp
/qemu
.log
2225 DEF("D", HAS_ARG
, QEMU_OPTION_D
, \
2226 "-D logfile output log to logfile (instead of the default /tmp/qemu.log)\n",
2231 Output log
in logfile instead of
/tmp
/qemu
.log
2234 DEF("hdachs", HAS_ARG
, QEMU_OPTION_hdachs
, \
2235 "-hdachs c,h,s[,t]\n" \
2236 " force hard disk 0 physical geometry and the optional BIOS\n" \
2237 " translation (t=none or lba) (usually qemu can guess them)\n",
2240 @item
-hdachs @
var{c
},@
var{h
},@
var{s
},[,@
var{t
}]
2242 Force hard disk
0 physical
geometry (1 <= @
var{c
} <= 16383, 1 <=
2243 @
var{h
} <= 16, 1 <= @
var{s
} <= 63) and optionally force the BIOS
2244 translation
mode (@
var{t
}=none
, lba or auto
). Usually QEMU can guess
2245 all those parameters
. This option is useful
for old MS
-DOS disk
2249 DEF("L", HAS_ARG
, QEMU_OPTION_L
, \
2250 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2255 Set the directory
for the BIOS
, VGA BIOS and keymaps
.
2258 DEF("bios", HAS_ARG
, QEMU_OPTION_bios
, \
2259 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL
)
2261 @item
-bios @
var{file
}
2263 Set the filename
for the BIOS
.
2266 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm
, \
2267 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL
)
2271 Enable KVM full virtualization support
. This option is only available
2272 if KVM support is enabled when compiling
.
2275 DEF("xen-domid", HAS_ARG
, QEMU_OPTION_xen_domid
,
2276 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL
)
2277 DEF("xen-create", 0, QEMU_OPTION_xen_create
,
2278 "-xen-create create domain using xen hypercalls, bypassing xend\n"
2279 " warning: should not be used when xend is in use\n",
2281 DEF("xen-attach", 0, QEMU_OPTION_xen_attach
,
2282 "-xen-attach attach to existing xen domain\n"
2283 " xend will use this when starting qemu\n",
2286 @item
-xen
-domid @
var{id
}
2288 Specify xen guest domain @
var{id
} (XEN only
).
2291 Create domain
using xen hypercalls
, bypassing xend
.
2292 Warning
: should not be used when xend is
in use (XEN only
).
2295 Attach to existing xen domain
.
2296 xend will use
this when starting
qemu (XEN only
).
2299 DEF("no-reboot", 0, QEMU_OPTION_no_reboot
, \
2300 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL
)
2304 Exit instead of rebooting
.
2307 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown
, \
2308 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL
)
2311 @findex
-no
-shutdown
2312 Don
't exit QEMU on guest shutdown, but instead only stop the emulation.
2313 This allows for instance switching to monitor to commit changes to the
2317 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
2318 "-loadvm [tag|id]\n" \
2319 " start right away with a saved state (loadvm in monitor)\n",
2322 @item -loadvm @var{file}
2324 Start right away with a saved state (@code{loadvm} in monitor)
2328 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
2329 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
2334 Daemonize the QEMU process after initialization. QEMU will not detach from
2335 standard IO until it is ready to receive connections on any of its devices.
2336 This option is a useful way for external programs to launch QEMU without having
2337 to cope with initialization race conditions.
2340 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
2341 "-option-rom rom load a file, rom, into the option ROM space\n",
2344 @item -option-rom @var{file}
2346 Load the contents of @var{file} as an option ROM.
2347 This option is useful to load things like EtherBoot.
2350 DEF("clock", HAS_ARG, QEMU_OPTION_clock, \
2351 "-clock force the use of the given methods for timer alarm.\n" \
2352 " To see what timers are available use -clock ?\n",
2355 @item -clock @var{method}
2357 Force the use of the given methods for timer alarm. To see what timers
2358 are available use -clock ?.
2361 HXCOMM Options deprecated by -rtc
2362 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
2363 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
2365 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
2366 "-rtc [base=utc|localtime|date][,clock=host|vm][,driftfix=none|slew]\n" \
2367 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
2372 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
2374 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
2375 UTC or local time, respectively. @code{localtime} is required for correct date in
2376 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
2377 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
2379 By default the RTC is driven by the host system time. This allows to use the
2380 RTC as accurate reference clock inside the guest, specifically if the host
2381 time is smoothly following an accurate external reference clock, e.g. via NTP.
2382 If you want to isolate the guest time from the host, even prevent it from
2383 progressing during suspension, you can set @option{clock} to @code{vm} instead.
2385 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
2386 specifically with Windows' ACPI HAL
. This option will
try to figure out how
2387 many timer interrupts were not processed by the Windows guest and will
2391 DEF("icount", HAS_ARG
, QEMU_OPTION_icount
, \
2392 "-icount [N|auto]\n" \
2393 " enable virtual instruction counter with 2^N clock ticks per\n" \
2394 " instruction\n", QEMU_ARCH_ALL
)
2396 @item
-icount
[@
var{N
}|auto
]
2398 Enable virtual instruction counter
. The virtual cpu will execute one
2399 instruction every
2^@
var{N
} ns of virtual time
. If @code
{auto
} is specified
2400 then the virtual cpu speed will be automatically adjusted to keep virtual
2401 time within a few seconds of real time
.
2403 Note that
while this option can give deterministic behavior
, it does not
2404 provide cycle accurate emulation
. Modern CPUs contain superscalar out of
2405 order cores with complex cache hierarchies
. The number of instructions
2406 executed often has little or no correlation with actual performance
.
2409 DEF("watchdog", HAS_ARG
, QEMU_OPTION_watchdog
, \
2410 "-watchdog i6300esb|ib700\n" \
2411 " enable virtual hardware watchdog [default=none]\n",
2414 @item
-watchdog @
var{model
}
2416 Create a virtual hardware watchdog device
. Once
enabled (by a guest
2417 action
), the watchdog must be periodically polled by an agent inside
2418 the guest or
else the guest will be restarted
.
2420 The @
var{model
} is the model of hardware watchdog to emulate
. Choices
2421 for model are
: @code
{ib700
} (iBASE
700) which is a very simple ISA
2422 watchdog with a single timer
, or @code
{i6300esb
} (Intel
6300ESB I
/O
2423 controller hub
) which is a much more featureful PCI
-based dual
-timer
2424 watchdog
. Choose a model
for which your guest has drivers
.
2426 Use @code
{-watchdog ?
} to list available hardware models
. Only one
2427 watchdog can be enabled
for a guest
.
2430 DEF("watchdog-action", HAS_ARG
, QEMU_OPTION_watchdog_action
, \
2431 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
2432 " action when watchdog fires [default=reset]\n",
2435 @item
-watchdog
-action @
var{action
}
2437 The @
var{action
} controls what QEMU will
do when the watchdog timer
2440 @code
{reset
} (forcefully reset the guest
).
2441 Other possible actions are
:
2442 @code
{shutdown
} (attempt to gracefully shutdown the guest
),
2443 @code
{poweroff
} (forcefully poweroff the guest
),
2444 @code
{pause
} (pause the guest
),
2445 @code
{debug
} (print a debug message and
continue), or
2446 @code
{none
} (do nothing
).
2448 Note that the @code
{shutdown
} action requires that the guest responds
2449 to ACPI signals
, which it may not be able to
do in the sort of
2450 situations where the watchdog would have expired
, and thus
2451 @code
{-watchdog
-action shutdown
} is not recommended
for production use
.
2456 @item
-watchdog i6300esb
-watchdog
-action pause
2457 @item
-watchdog ib700
2461 DEF("echr", HAS_ARG
, QEMU_OPTION_echr
, \
2462 "-echr chr set terminal escape character instead of ctrl-a\n",
2466 @item
-echr @
var{numeric_ascii_value
}
2468 Change the escape character used
for switching to the monitor when
using
2469 monitor and serial sharing
. The
default is @code
{0x01} when
using the
2470 @code
{-nographic
} option
. @code
{0x01} is equal to pressing
2471 @code
{Control
-a
}. You can select a different character from the ascii
2472 control keys where
1 through
26 map to Control
-a through Control
-z
. For
2473 instance you could use the either of the following to change the escape
2474 character to Control
-t
.
2481 DEF("virtioconsole", HAS_ARG
, QEMU_OPTION_virtiocon
, \
2482 "-virtioconsole c\n" \
2483 " set virtio console\n", QEMU_ARCH_ALL
)
2485 @item
-virtioconsole @
var{c
}
2486 @findex
-virtioconsole
2489 This option is maintained
for backward compatibility
.
2491 Please use @code
{-device virtconsole
} for the
new way of invocation
.
2494 DEF("show-cursor", 0, QEMU_OPTION_show_cursor
, \
2495 "-show-cursor show cursor\n", QEMU_ARCH_ALL
)
2498 @findex
-show
-cursor
2502 DEF("tb-size", HAS_ARG
, QEMU_OPTION_tb_size
, \
2503 "-tb-size n set TB size\n", QEMU_ARCH_ALL
)
2505 @item
-tb
-size @
var{n
}
2510 DEF("incoming", HAS_ARG
, QEMU_OPTION_incoming
, \
2511 "-incoming p prepare for incoming migration, listen on port p\n",
2514 @item
-incoming @
var{port
}
2516 Prepare
for incoming migration
, listen on @
var{port
}.
2519 DEF("nodefaults", 0, QEMU_OPTION_nodefaults
, \
2520 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL
)
2524 Don
't create default devices.
2528 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
2529 "-chroot dir chroot to dir just before starting the VM\n",
2533 @item -chroot @var{dir}
2535 Immediately before starting guest execution, chroot to the specified
2536 directory. Especially useful in combination with -runas.
2540 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
2541 "-runas user change to user id user just before starting the VM\n",
2545 @item -runas @var{user}
2547 Immediately before starting guest execution, drop root privileges, switching
2548 to the specified user.
2551 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
2552 "-prom-env variable=value\n"
2553 " set OpenBIOS nvram variables\n",
2554 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
2556 @item -prom-env @var{variable}=@var{value}
2558 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
2560 DEF("semihosting", 0, QEMU_OPTION_semihosting,
2561 "-semihosting semihosting mode\n", QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA)
2564 @findex -semihosting
2565 Semihosting mode (ARM, M68K, Xtensa only).
2567 DEF("old-param", 0, QEMU_OPTION_old_param,
2568 "-old-param old param mode\n", QEMU_ARCH_ARM)
2571 @findex -old-param (ARM)
2572 Old param mode (ARM only).
2575 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
2576 "-readconfig <file>\n", QEMU_ARCH_ALL)
2578 @item -readconfig @var{file}
2580 Read device configuration from @var{file}.
2582 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
2583 "-writeconfig <file>\n"
2584 " read/write config file\n", QEMU_ARCH_ALL)
2586 @item -writeconfig @var{file}
2587 @findex -writeconfig
2588 Write device configuration to @var{file}.
2590 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
2592 " do not load default config files at startup\n",
2596 @findex -nodefconfig
2597 Normally QEMU loads a configuration file from @var{sysconfdir}/qemu.conf and
2598 @var{sysconfdir}/target-@var{ARCH}.conf on startup. The @code{-nodefconfig}
2599 option will prevent QEMU from loading these configuration files at startup.
2601 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
2602 "-trace [events=<file>][,file=<file>]\n"
2603 " specify tracing options\n",
2606 HXCOMM This line is not accurate, as some sub-options are backend-specific but
2607 HXCOMM HX does not support conditional compilation of text.
2608 @item -trace [events=@var{file}][,file=@var{file}]
2611 Specify tracing options.
2614 @item events=@var{file}
2615 Immediately enable events listed in @var{file}.
2616 The file must contain one event name (as listed in the @var{trace-events} file)
2618 This option is only available if QEMU has been compiled with
2619 either @var{simple} or @var{stderr} tracing backend.
2620 @item file=@var{file}
2621 Log output traces to @var{file}.
2623 This option is only available if QEMU has been compiled with
2624 the @var{simple} tracing backend.
2628 HXCOMM This is the last statement. Insert new options before this line!