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"
36 " kvm_shadow_mem=size of KVM shadow MMU\n",
39 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
41 Select the emulated machine by @
var{name
}. Use @code
{-machine ?
} to list
42 available machines
. Supported machine properties are
:
44 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
45 This is used to enable an accelerator
. Depending on the target architecture
,
46 kvm
, xen
, or tcg can be available
. By
default, tcg is used
. If there is more
47 than one accelerator specified
, the next one is used
if the previous one fails
49 @item kernel_irqchip
=on|off
50 Enables
in-kernel irqchip support
for the chosen accelerator when available
.
51 @item kvm_shadow_mem
=size
52 Defines the size of the KVM shadow MMU
.
56 HXCOMM Deprecated by
-machine
57 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
59 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
60 "-cpu cpu select CPU (-cpu ? for list)\n", QEMU_ARCH_ALL
)
62 @item
-cpu @
var{model
}
64 Select CPU
model (-cpu ?
for list and additional feature selection
)
67 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
68 "-smp n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
69 " set the number of CPUs to 'n' [default=1]\n"
70 " maxcpus= maximum number of total cpus, including\n"
71 " offline CPUs for hotplug, etc\n"
72 " cores= number of CPU cores on one socket\n"
73 " threads= number of threads on one CPU core\n"
74 " sockets= number of discrete sockets in the system\n",
77 @item
-smp @
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
79 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
80 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
82 For the PC target
, the number of @
var{cores
} per socket
, the number
83 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
84 specified
. Missing values will be computed
. If any on the three values is
85 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
86 specifies the maximum number of hotpluggable CPUs
.
89 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
90 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL
)
92 @item
-numa @
var{opts
}
94 Simulate a multi node NUMA system
. If mem and cpus are omitted
, resources
98 DEF("fda", HAS_ARG
, QEMU_OPTION_fda
,
99 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL
)
100 DEF("fdb", HAS_ARG
, QEMU_OPTION_fdb
, "", QEMU_ARCH_ALL
)
102 @item
-fda @
var{file
}
103 @item
-fdb @
var{file
}
106 Use @
var{file
} as floppy disk
0/1 image (@pxref
{disk_images
}). You can
107 use the host floppy by
using @file
{/dev
/fd0
} as
filename (@pxref
{host_drives
}).
110 DEF("hda", HAS_ARG
, QEMU_OPTION_hda
,
111 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL
)
112 DEF("hdb", HAS_ARG
, QEMU_OPTION_hdb
, "", QEMU_ARCH_ALL
)
113 DEF("hdc", HAS_ARG
, QEMU_OPTION_hdc
,
114 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL
)
115 DEF("hdd", HAS_ARG
, QEMU_OPTION_hdd
, "", QEMU_ARCH_ALL
)
117 @item
-hda @
var{file
}
118 @item
-hdb @
var{file
}
119 @item
-hdc @
var{file
}
120 @item
-hdd @
var{file
}
125 Use @
var{file
} as hard disk
0, 1, 2 or
3 image (@pxref
{disk_images
}).
128 DEF("cdrom", HAS_ARG
, QEMU_OPTION_cdrom
,
129 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
132 @item
-cdrom @
var{file
}
134 Use @
var{file
} as CD
-ROM
image (you cannot use @option
{-hdc
} and
135 @option
{-cdrom
} at the same time
). You can use the host CD
-ROM by
136 using @file
{/dev
/cdrom
} as
filename (@pxref
{host_drives
}).
139 DEF("drive", HAS_ARG
, QEMU_OPTION_drive
,
140 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
141 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
142 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
143 " [,serial=s][,addr=A][,id=name][,aio=threads|native]\n"
144 " [,readonly=on|off][,copy-on-read=on|off]\n"
145 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]][[,iops=i]|[[,iops_rd=r][,iops_wr=w]]\n"
146 " use 'file' as a drive image\n", QEMU_ARCH_ALL
)
148 @item
-drive @
var{option
}[,@
var{option
}[,@
var{option
}[,...]]]
151 Define a
new drive
. Valid options are
:
154 @item file
=@
var{file
}
155 This option defines which disk
image (@pxref
{disk_images
}) to use with
156 this drive
. If the filename contains comma
, you must double it
157 (for instance
, "file=my,,file" to use file
"my,file").
159 Special files such as iSCSI devices can be specified
using protocol
160 specific URLs
. See the section
for "Device URL Syntax" for more information
.
161 @item
if=@
var{interface}
162 This option defines on which type on
interface the drive is connected
.
163 Available types are
: ide
, scsi
, sd
, mtd
, floppy
, pflash
, virtio
.
164 @item bus
=@
var{bus
},unit
=@
var{unit
}
165 These options define where is connected the drive by defining the bus number and
167 @item index
=@
var{index
}
168 This option defines where is connected the drive by
using an index
in the list
169 of available connectors of a given
interface type
.
170 @item media
=@
var{media
}
171 This option defines the type of the media
: disk or cdrom
.
172 @item cyls
=@
var{c
},heads
=@
var{h
},secs
=@
var{s
}[,trans
=@
var{t
}]
173 These options have the same definition as they have
in @option
{-hdachs
}.
174 @item snapshot
=@
var{snapshot
}
175 @
var{snapshot
} is
"on" or
"off" and allows to enable snapshot
for given
drive (see @option
{-snapshot
}).
176 @item cache
=@
var{cache
}
177 @
var{cache
} is
"none", "writeback", "unsafe", "directsync" or
"writethrough" and controls how the host cache is used to access block data
.
179 @
var{aio
} is
"threads", or
"native" and selects between pthread based disk I
/O and native Linux AIO
.
180 @item format
=@
var{format
}
181 Specify which disk @
var{format
} will be used rather than detecting
182 the format
. Can be used to specifiy format
=raw to avoid interpreting
183 an untrusted format header
.
184 @item serial
=@
var{serial
}
185 This option specifies the serial number to assign to the device
.
186 @item addr
=@
var{addr
}
187 Specify the controller
's PCI address (if=virtio only).
188 @item werror=@var{action},rerror=@var{action}
189 Specify which @var{action} to take on write and read errors. Valid actions are:
190 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
191 "report" (report the error to the guest), "enospc" (pause QEMU only if the
192 host disk is full; report the error to the guest otherwise).
193 The default setting is @option{werror=enospc} and @option{rerror=report}.
195 Open drive @option{file} as read-only. Guest write attempts will fail.
196 @item copy-on-read=@var{copy-on-read}
197 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
198 file sectors into the image file.
201 By default, writethrough caching is used for all block device. This means that
202 the host page cache will be used to read and write data but write notification
203 will be sent to the guest only when the data has been reported as written by
204 the storage subsystem.
206 Writeback caching will report data writes as completed as soon as the data is
207 present in the host page cache. This is safe as long as you trust your host.
208 If your host crashes or loses power, then the guest may experience data
211 The host page cache can be avoided entirely with @option{cache=none}. This will
212 attempt to do disk IO directly to the guests memory. QEMU may still perform
213 an internal copy of the data.
215 The host page cache can be avoided while only sending write notifications to
216 the guest when the data has been reported as written by the storage subsystem
217 using @option{cache=directsync}.
219 Some block drivers perform badly with @option{cache=writethrough}, most notably,
220 qcow2. If performance is more important than correctness,
221 @option{cache=writeback} should be used with qcow2.
223 In case you don't care about data integrity over host failures
, use
224 cache
=unsafe
. This option tells qemu that it
never needs to write any data
225 to the disk but can instead keeps things
in cache
. If anything goes wrong
,
226 like your host losing power
, the disk storage getting disconnected accidentally
,
227 etc
. you
're image will most probably be rendered unusable. When using
228 the @option{-snapshot} option, unsafe caching is always used.
230 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
231 useful when the backing file is over a slow network. By default copy-on-read
234 Instead of @option{-cdrom} you can use:
236 qemu -drive file=file,index=2,media=cdrom
239 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
242 qemu -drive file=file,index=0,media=disk
243 qemu -drive file=file,index=1,media=disk
244 qemu -drive file=file,index=2,media=disk
245 qemu -drive file=file,index=3,media=disk
248 You can connect a CDROM to the slave of ide0:
250 qemu -drive file=file,if=ide,index=1,media=cdrom
253 If you don't specify the
"file=" argument
, you define an empty drive
:
255 qemu
-drive
if=ide
,index
=1,media
=cdrom
258 You can connect a SCSI disk with unit ID
6 on the bus #
0:
260 qemu
-drive file
=file
,if=scsi
,bus
=0,unit
=6
263 Instead of @option
{-fda
}, @option
{-fdb
}, you can use
:
265 qemu
-drive file
=file
,index
=0,if=floppy
266 qemu
-drive file
=file
,index
=1,if=floppy
269 By
default, @
var{interface} is
"ide" and @
var{index
} is automatically
272 qemu
-drive file
=a
-drive file
=b
"
280 DEF("set
", HAS_ARG, QEMU_OPTION_set,
281 "-set group
.id
.arg
=value
\n"
282 " set
<arg
> parameter
for item
<id
> of type
<group
>\n"
283 " i
.e
. -set drive
.$id
.file
=/path
/to
/image
\n", QEMU_ARCH_ALL)
290 DEF("global
", HAS_ARG, QEMU_OPTION_global,
291 "-global driver
.property
=value
\n"
292 " set a global
default for a driver property
\n",
300 DEF("mtdblock
", HAS_ARG, QEMU_OPTION_mtdblock,
301 "-mtdblock file use
'file' as on
-board Flash memory image
\n",
304 @item -mtdblock @var{file}
306 Use @var{file} as on-board Flash memory image.
309 DEF("sd
", HAS_ARG, QEMU_OPTION_sd,
310 "-sd file use
'file' as SecureDigital card image
\n", QEMU_ARCH_ALL)
314 Use @var{file} as SecureDigital card image.
317 DEF("pflash
", HAS_ARG, QEMU_OPTION_pflash,
318 "-pflash file use
'file' as a parallel flash image
\n", QEMU_ARCH_ALL)
320 @item -pflash @var{file}
322 Use @var{file} as a parallel flash image.
325 DEF("boot
", HAS_ARG, QEMU_OPTION_boot,
326 "-boot
[order
=drives
][,once
=drives
][,menu
=on|off
]\n"
327 " [,splash
=sp_name
][,splash
-time
=sp_time
]\n"
328 " 'drives': floppy (a
), hard
disk (c
), CD
-ROM (d
), network (n
)\n"
329 " 'sp_name': the file
's name that would be passed to bios as logo picture, if menu=on\n"
330 " 'sp_time
': the period that splash picture last if menu=on, unit is ms\n",
333 @item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}]
335 Specify boot order @var{drives} as a string of drive letters. Valid
336 drive letters depend on the target achitecture. The x86 PC uses: a, b
337 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
338 from network adapter 1-4), hard disk boot is the default. To apply a
339 particular boot order only on the first startup, specify it via
342 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
343 as firmware/BIOS supports them. The default is non-interactive boot.
345 A splash picture could be passed to bios, enabling user to show it as logo,
346 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
347 supports them. Currently Seabios for X86 system support it.
348 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
349 format(true color). The resolution should be supported by the SVGA mode, so
350 the recommended is 320x240, 640x480, 800x640.
353 # try to boot from network first, then from hard disk
355 # boot from CD-ROM first, switch back to default order after reboot
357 # boot with a splash picture for 5 seconds.
358 qemu -boot menu=on,splash=/root/boot.bmp,splash-time=5000
361 Note: The legacy format '-boot @
var{drives
}' is still supported but its
362 use is discouraged as it may be removed from future versions.
365 DEF("snapshot", 0, QEMU_OPTION_snapshot,
366 "-snapshot write to temporary files instead of disk image files\n",
371 Write to temporary files instead of disk image files. In this case,
372 the raw disk image you use is not written back. You can however force
373 the write back by pressing @key{C-a s} (@pxref{disk_images}).
376 DEF("m", HAS_ARG, QEMU_OPTION_m,
377 "-m megs set virtual RAM size to megs MB [default="
378 stringify(DEFAULT_RAM_SIZE) "]\n", QEMU_ARCH_ALL)
382 Set virtual RAM size to @var{megs} megabytes. Default is 128 MiB. Optionally,
383 a suffix of ``M'' or ``G'' can be used to signify a value in megabytes or
384 gigabytes respectively.
387 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
388 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
390 @item -mem-path @var{path}
391 Allocate guest RAM from a temporarily created file in @var{path}.
395 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
396 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
400 Preallocate memory when using -mem-path.
404 DEF("k", HAS_ARG, QEMU_OPTION_k,
405 "-k language use keyboard layout (for example 'fr
' for French)\n",
408 @item -k @var{language}
410 Use keyboard layout @var{language} (for example @code{fr} for
411 French). This option is only needed where it is not easy to get raw PC
412 keycodes (e.g. on Macs, with some X11 servers or with a VNC
413 display). You don't normally need to use it on PC
/Linux or PC
/Windows
416 The available layouts are
:
418 ar de
-ch es fo fr
-ca hu ja mk no pt
-br sv
419 da en
-gb et fr fr
-ch is lt nl pl ru th
420 de en
-us fi fr
-be hr it lv nl
-be pt sl tr
423 The
default is @code
{en
-us
}.
427 DEF("audio-help", 0, QEMU_OPTION_audio_help
,
428 "-audio-help print list of audio drivers and their options\n",
433 Will show the audio subsystem help
: list of drivers
, tunable
437 DEF("soundhw", HAS_ARG
, QEMU_OPTION_soundhw
,
438 "-soundhw c1,... enable audio support\n"
439 " and only specified sound cards (comma separated list)\n"
440 " use -soundhw ? to get the list of supported cards\n"
441 " use -soundhw all to enable all of them\n", QEMU_ARCH_ALL
)
443 @item
-soundhw @
var{card1
}[,@
var{card2
},...] or
-soundhw all
445 Enable audio and selected sound hardware
. Use ? to print all
446 available sound hardware
.
449 qemu
-soundhw sb16
,adlib disk
.img
450 qemu
-soundhw es1370 disk
.img
451 qemu
-soundhw ac97 disk
.img
452 qemu
-soundhw hda disk
.img
453 qemu
-soundhw all disk
.img
457 Note that Linux
's i810_audio OSS kernel (for AC97) module might
458 require manually specifying clocking.
461 modprobe i810_audio clocking=48000
465 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
466 "-balloon none disable balloon device\n"
467 "-balloon virtio[,addr=str]\n"
468 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
472 Disable balloon device.
473 @item -balloon virtio[,addr=@var{addr}]
474 Enable virtio balloon device (default), optionally with PCI address
482 DEF("usb", 0, QEMU_OPTION_usb,
483 "-usb enable the USB driver (will be the default soon)\n",
491 Enable the USB driver (will be the default soon)
494 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
495 "-usbdevice name add the host or guest USB device 'name
'\n",
499 @item -usbdevice @var{devname}
501 Add the USB device @var{devname}. @xref{usb_devices}.
506 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
509 Pointer device that uses absolute coordinates (like a touchscreen). This
510 means qemu is able to report the mouse position without having to grab the
511 mouse. Also overrides the PS/2 mouse emulation when activated.
513 @item disk:[format=@var{format}]:@var{file}
514 Mass storage device based on file. The optional @var{format} argument
515 will be used rather than detecting the format. Can be used to specifiy
516 @code{format=raw} to avoid interpreting an untrusted format header.
518 @item host:@var{bus}.@var{addr}
519 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
521 @item host:@var{vendor_id}:@var{product_id}
522 Pass through the host device identified by @var{vendor_id}:@var{product_id}
525 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
526 Serial converter to host character device @var{dev}, see @code{-serial} for the
530 Braille device. This will use BrlAPI to display the braille output on a real
533 @item net:@var{options}
534 Network adapter that supports CDC ethernet and RNDIS protocols.
539 DEF("device", HAS_ARG, QEMU_OPTION_device,
540 "-device driver[,prop[=value][,...]]\n"
541 " add device (based on driver)\n"
542 " prop=value,... sets driver properties\n"
543 " use -device ? to print all possible drivers\n"
544 " use -device driver,? to print all possible properties\n",
547 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
549 Add device @var{driver}. @var{prop}=@var{value} sets driver
550 properties. Valid properties depend on the driver. To get help on
551 possible drivers and properties, use @code{-device ?} and
552 @code{-device @var{driver},?}.
557 DEFHEADING(File system options:)
559 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
560 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
561 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
566 @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}]
568 Define a new file system device. Valid options are:
571 This option specifies the fs driver backend to use.
572 Currently "local", "handle" and "proxy" file system drivers are supported.
574 Specifies identifier for this device
575 @item path=@var{path}
576 Specifies the export path for the file system device. Files under
577 this path will be available to the 9p client on the guest.
578 @item security_model=@var{security_model}
579 Specifies the security model to be used for this export path.
580 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
581 In "passthrough" security model, files are stored using the same
582 credentials as they are created on the guest. This requires qemu
583 to run as root. In "mapped-xattr" security model, some of the file
584 attributes like uid, gid, mode bits and link target are stored as
585 file attributes. For "mapped-file" these attributes are stored in the
586 hidden .virtfs_metadata directory. Directories exported by this security model cannot
587 interact with other unix tools. "none" security model is same as
588 passthrough except the sever won't report failures
if it fails to
589 set file attributes like ownership
. Security model is mandatory
590 only
for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take
591 security model as a parameter.
592 @item writeout=@var{writeout}
593 This is an optional argument. The only supported value is "immediate".
594 This means that host page cache will be used to read and write data but
595 write notification will be sent to the guest only when the data has been
596 reported as written by the storage subsystem.
598 Enables exporting 9p share as a readonly mount for guests. By default
599 read-write access is given.
600 @item socket=@var{socket}
601 Enables proxy filesystem driver to use passed socket file for communicating
602 with virtfs-proxy-helper
603 @item sock_fd=@var{sock_fd}
604 Enables proxy filesystem driver to use passed socket descriptor for
605 communicating with virtfs-proxy-helper. Usually a helper like libvirt
606 will create socketpair and pass one of the fds as sock_fd
609 -fsdev option is used along with -device driver "virtio-9p-pci".
610 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
611 Options for virtio-9p-pci driver are:
614 Specifies the id value specified along with -fsdev option
615 @item mount_tag=@var{mount_tag}
616 Specifies the tag name to be used by the guest to mount this export point
623 DEFHEADING(Virtual File system pass-through options:)
625 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
626 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
627 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
632 @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}]
635 The general form of a Virtual File system pass-through options are:
638 This option specifies the fs driver backend to use.
639 Currently "local", "handle" and "proxy" file system drivers are supported.
641 Specifies identifier for this device
642 @item path=@var{path}
643 Specifies the export path for the file system device. Files under
644 this path will be available to the 9p client on the guest.
645 @item security_model=@var{security_model}
646 Specifies the security model to be used for this export path.
647 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
648 In "passthrough" security model, files are stored using the same
649 credentials as they are created on the guest. This requires qemu
650 to run as root. In "mapped-xattr" security model, some of the file
651 attributes like uid, gid, mode bits and link target are stored as
652 file attributes. For "mapped-file" these attributes are stored in the
653 hidden .virtfs_metadata directory. Directories exported by this security model cannot
654 interact with other unix tools. "none" security model is same as
655 passthrough except the sever won't report failures
if it fails to
656 set file attributes like ownership
. Security model is mandatory only
657 for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take security
658 model as a parameter.
659 @item writeout=@var{writeout}
660 This is an optional argument. The only supported value is "immediate".
661 This means that host page cache will be used to read and write data but
662 write notification will be sent to the guest only when the data has been
663 reported as written by the storage subsystem.
665 Enables exporting 9p share as a readonly mount for guests. By default
666 read-write access is given.
667 @item socket=@var{socket}
668 Enables proxy filesystem driver to use passed socket file for
669 communicating with virtfs-proxy-helper. Usually a helper like libvirt
670 will create socketpair and pass one of the fds as sock_fd
672 Enables proxy filesystem driver to use passed 'sock_fd
' as the socket
673 descriptor for interfacing with virtfs-proxy-helper
677 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
678 "-virtfs_synth Create synthetic file system image\n",
682 @findex -virtfs_synth
683 Create synthetic file system image
688 DEF("name", HAS_ARG, QEMU_OPTION_name,
689 "-name string1[,process=string2]\n"
690 " set the name of the guest\n"
691 " string1 sets the window title and string2 the process name (on Linux)\n",
694 @item -name @var{name}
696 Sets the @var{name} of the guest.
697 This name will be displayed in the SDL window caption.
698 The @var{name} will also be used for the VNC server.
699 Also optionally set the top visible process name in Linux.
702 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
703 "-uuid %08x-%04x-%04x-%04x-%012x\n"
704 " specify machine UUID\n", QEMU_ARCH_ALL)
706 @item -uuid @var{uuid}
717 DEFHEADING(Display options:)
723 DEF("display", HAS_ARG, QEMU_OPTION_display,
724 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
725 " [,window_close=on|off]|curses|none|\n"
726 " vnc=<display>[,<optargs>]\n"
727 " select display type\n", QEMU_ARCH_ALL)
729 @item -display @var{type}
731 Select type of display to use. This option is a replacement for the
732 old style -sdl/-curses/... options. Valid values for @var{type} are
735 Display video output via SDL (usually in a separate graphics
736 window; see the SDL documentation for other possibilities).
738 Display video output via curses. For graphics device models which
739 support a text mode, QEMU can display this output using a
740 curses/ncurses interface. Nothing is displayed when the graphics
741 device is in graphical mode or if the graphics device does not support
742 a text mode. Generally only the VGA device models support text mode.
744 Do not display video output. The guest will still see an emulated
745 graphics card, but its output will not be displayed to the QEMU
746 user. This option differs from the -nographic option in that it
747 only affects what is done with video output; -nographic also changes
748 the destination of the serial and parallel port data.
750 Start a VNC server on display <arg>
754 DEF("nographic", 0, QEMU_OPTION_nographic,
755 "-nographic disable graphical output and redirect serial I/Os to console\n",
760 Normally, QEMU uses SDL to display the VGA output. With this option,
761 you can totally disable graphical output so that QEMU is a simple
762 command line application. The emulated serial port is redirected on
763 the console. Therefore, you can still use QEMU to debug a Linux kernel
764 with a serial console.
767 DEF("curses", 0, QEMU_OPTION_curses,
768 "-curses use a curses/ncurses interface instead of SDL\n",
773 Normally, QEMU uses SDL to display the VGA output. With this option,
774 QEMU can display the VGA output when in text mode using a
775 curses/ncurses interface. Nothing is displayed in graphical mode.
778 DEF("no-frame", 0, QEMU_OPTION_no_frame,
779 "-no-frame open SDL window without a frame and window decorations\n",
784 Do not use decorations for SDL windows and start them using the whole
785 available screen space. This makes the using QEMU in a dedicated desktop
786 workspace more convenient.
789 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
790 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
795 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
796 affects the special keys (for fullscreen, monitor-mode switching, etc).
799 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
800 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
805 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
806 affects the special keys (for fullscreen, monitor-mode switching, etc).
809 DEF("no-quit", 0, QEMU_OPTION_no_quit,
810 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
814 Disable SDL window close capability.
817 DEF("sdl", 0, QEMU_OPTION_sdl,
818 "-sdl enable SDL\n", QEMU_ARCH_ALL)
825 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
826 "-spice <args> enable spice\n", QEMU_ARCH_ALL)
828 @item -spice @var{option}[,@var{option}[,...]]
830 Enable the spice remote desktop protocol. Valid options are
835 Set the TCP port spice is listening on for plaintext channels.
838 Set the IP address spice is listening on. Default is any address.
842 Force using the specified IP version.
844 @item password=<secret>
845 Set the password you need to authenticate.
848 Require that the client use SASL to authenticate with the spice.
849 The exact choice of authentication method used is controlled from the
850 system / user's SASL configuration file
for the
'qemu' service
. This
851 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
852 unprivileged user
, an environment variable SASL_CONF_PATH can be used
853 to make it search alternate locations
for the service config
.
854 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
855 it is recommended that SASL always be combined with the
'tls' and
856 'x509' settings to enable use of SSL and server certificates
. This
857 ensures a data encryption preventing compromise of authentication
860 @item disable
-ticketing
861 Allow client connects without authentication
.
863 @item disable
-copy
-paste
864 Disable copy paste between the client and the guest
.
867 Set the TCP port spice is listening on
for encrypted channels
.
870 Set the x509 file directory
. Expects same filenames as
-vnc $display
,x509
=$dir
872 @item x509
-key
-file
=<file
>
873 @item x509
-key
-password
=<file
>
874 @item x509
-cert
-file
=<file
>
875 @item x509
-cacert
-file
=<file
>
876 @item x509
-dh
-key
-file
=<file
>
877 The x509 file names can also be configured individually
.
879 @item tls
-ciphers
=<list
>
880 Specify which ciphers to use
.
882 @item tls
-channel
=[main|display|cursor|inputs|record|playback
]
883 @item plaintext
-channel
=[main|display|cursor|inputs|record|playback
]
884 Force specific channel to be used with or without TLS encryption
. The
885 options can be specified multiple times to configure multiple
886 channels
. The special name
"default" can be used to set the
default
887 mode
. For channels which are not explicitly forced into one mode the
888 spice client is allowed to pick tls
/plaintext as he pleases
.
890 @item image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]
891 Configure image
compression (lossless
).
894 @item jpeg
-wan
-compression
=[auto|
never|always
]
895 @item zlib
-glz
-wan
-compression
=[auto|
never|always
]
896 Configure wan image
compression (lossy
for slow links
).
899 @item streaming
-video
=[off|all|filter
]
900 Configure video stream detection
. Default is filter
.
902 @item agent
-mouse
=[on|off
]
903 Enable
/disable passing mouse events via vdagent
. Default is on
.
905 @item playback
-compression
=[on|off
]
906 Enable
/disable audio stream
compression (using celt
0.5.1). Default is on
.
911 DEF("portrait", 0, QEMU_OPTION_portrait
,
912 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
917 Rotate graphical output
90 deg
left (only PXA LCD
).
920 DEF("rotate", HAS_ARG
, QEMU_OPTION_rotate
,
921 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
926 Rotate graphical output some deg
left (only PXA LCD
).
929 DEF("vga", HAS_ARG
, QEMU_OPTION_vga
,
930 "-vga [std|cirrus|vmware|qxl|xenfb|none]\n"
931 " select video card type\n", QEMU_ARCH_ALL
)
933 @item
-vga @
var{type
}
935 Select type of VGA card to emulate
. Valid values
for @
var{type
} are
938 Cirrus Logic GD5446 Video card
. All Windows versions starting from
939 Windows
95 should recognize and use
this graphic card
. For optimal
940 performances
, use
16 bit color depth
in the guest and the host OS
.
941 (This one is the
default)
943 Standard VGA card with Bochs VBE extensions
. If your guest OS
944 supports the VESA
2.0 VBE
extensions (e
.g
. Windows XP
) and
if you want
945 to use high resolution
modes (>= 1280x1024x16
) then you should use
948 VMWare SVGA
-II compatible adapter
. Use it
if you have sufficiently
949 recent XFree86
/XOrg server or Windows guest with a driver
for this
952 QXL paravirtual graphic card
. It is VGA
compatible (including VESA
953 2.0 VBE support
). Works best with qxl guest drivers installed though
.
954 Recommended choice when
using the spice protocol
.
960 DEF("full-screen", 0, QEMU_OPTION_full_screen
,
961 "-full-screen start in full screen\n", QEMU_ARCH_ALL
)
965 Start
in full screen
.
968 DEF("g", 1, QEMU_OPTION_g
,
969 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
970 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
972 @item
-g @
var{width
}x@
var{height
}[x@
var{depth
}]
974 Set the initial graphical resolution and
depth (PPC
, SPARC only
).
977 DEF("vnc", HAS_ARG
, QEMU_OPTION_vnc
,
978 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL
)
980 @item
-vnc @
var{display
}[,@
var{option
}[,@
var{option
}[,...]]]
982 Normally
, QEMU uses SDL to display the VGA output
. With
this option
,
983 you can have QEMU listen on VNC display @
var{display
} and redirect the VGA
984 display over the VNC session
. It is very useful to enable the usb
985 tablet device when
using this option (option @option
{-usbdevice
986 tablet
}). When
using the VNC display
, you must use the @option
{-k
}
987 parameter to set the keyboard layout
if you are not
using en
-us
. Valid
988 syntax
for the @
var{display
} is
992 @item @
var{host
}:@
var{d
}
994 TCP connections will only be allowed from @
var{host
} on display @
var{d
}.
995 By convention the TCP port is
5900+@
var{d
}. Optionally
, @
var{host
} can
996 be omitted
in which
case the server will accept connections from any host
.
998 @item unix
:@
var{path
}
1000 Connections will be allowed over UNIX domain sockets where @
var{path
} is the
1001 location of a unix socket to listen
for connections on
.
1005 VNC is initialized but not started
. The monitor @code
{change
} command
1006 can be used to later start the VNC server
.
1010 Following the @
var{display
} value there may be one or more @
var{option
} flags
1011 separated by commas
. Valid options are
1017 Connect to a listening VNC client via a ``reverse
'' connection
. The
1018 client is specified by the @
var{display
}. For reverse network
1019 connections (@
var{host
}:@
var{d
},@code
{reverse
}), the @
var{d
} argument
1020 is a TCP port number
, not a display number
.
1024 Require that password based authentication is used
for client connections
.
1025 The password must be set separately
using the @code
{change
} command
in the
1030 Require that client use TLS when communicating with the VNC server
. This
1031 uses anonymous TLS credentials so is susceptible to a man
-in-the
-middle
1032 attack
. It is recommended that
this option be combined with either the
1033 @option
{x509
} or @option
{x509verify
} options
.
1035 @item x509
=@
var{/path
/to
/certificate
/dir
}
1037 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1038 for negotiating the TLS session
. The server will send its x509 certificate
1039 to the client
. It is recommended that a password be set on the VNC server
1040 to provide authentication of the client when
this is used
. The path following
1041 this option specifies where the x509 certificates are to be loaded from
.
1042 See the @ref
{vnc_security
} section
for details on generating certificates
.
1044 @item x509verify
=@
var{/path
/to
/certificate
/dir
}
1046 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1047 for negotiating the TLS session
. The server will send its x509 certificate
1048 to the client
, and request that the client send its own x509 certificate
.
1049 The server will validate the client
's certificate against the CA certificate,
1050 and reject clients when validation fails. If the certificate authority is
1051 trusted, this is a sufficient authentication mechanism. You may still wish
1052 to set a password on the VNC server as a second authentication layer. The
1053 path following this option specifies where the x509 certificates are to
1054 be loaded from. See the @ref{vnc_security} section for details on generating
1059 Require that the client use SASL to authenticate with the VNC server.
1060 The exact choice of authentication method used is controlled from the
1061 system / user's SASL configuration file
for the
'qemu' service
. This
1062 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
1063 unprivileged user
, an environment variable SASL_CONF_PATH can be used
1064 to make it search alternate locations
for the service config
.
1065 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
1066 it is recommended that SASL always be combined with the
'tls' and
1067 'x509' settings to enable use of SSL and server certificates
. This
1068 ensures a data encryption preventing compromise of authentication
1069 credentials
. See the @ref
{vnc_security
} section
for details on
using
1070 SASL authentication
.
1074 Turn on access control lists
for checking of the x509 client certificate
1075 and SASL party
. For x509 certs
, the ACL check is made against the
1076 certificate
's distinguished name. This is something that looks like
1077 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1078 made against the username, which depending on the SASL plugin, may
1079 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1080 When the @option{acl} flag is set, the initial access list will be
1081 empty, with a @code{deny} policy. Thus no one will be allowed to
1082 use the VNC server until the ACLs have been loaded. This can be
1083 achieved using the @code{acl} monitor command.
1087 Enable lossy compression methods (gradient, JPEG, ...). If this
1088 option is set, VNC client may receive lossy framebuffer updates
1089 depending on its encoding settings. Enabling this option can save
1090 a lot of bandwidth at the expense of quality.
1094 Disable adaptive encodings. Adaptive encodings are enabled by default.
1095 An adaptive encoding will try to detect frequently updated screen regions,
1096 and send updates in these regions using a lossy encoding (like JPEG).
1097 This can be really helpful to save bandwidth when playing videos. Disabling
1098 adaptive encodings allows to restore the original static behavior of encodings
1101 @item share=[allow-exclusive|force-shared|ignore]
1103 Set display sharing policy. 'allow
-exclusive
' allows clients to ask
1104 for exclusive access. As suggested by the rfb spec this is
1105 implemented by dropping other connections. Connecting multiple
1106 clients in parallel requires all clients asking for a shared session
1107 (vncviewer: -shared switch). This is the default. 'force
-shared
'
1108 disables exclusive client access. Useful for shared desktop sessions,
1109 where you don't want someone forgetting specify
-shared disconnect
1110 everybody
else. 'ignore' completely ignores the shared flag and
1111 allows everybody connect unconditionally
. Doesn
't conform to the rfb
1112 spec but is traditional qemu behavior.
1121 ARCHHEADING(, QEMU_ARCH_I386)
1123 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1128 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1129 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1134 Use it when installing Windows 2000 to avoid a disk full bug. After
1135 Windows 2000 is installed, you no longer need this option (this option
1136 slows down the IDE transfers).
1139 HXCOMM Deprecated by -rtc
1140 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1142 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1143 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1146 @item -no-fd-bootchk
1147 @findex -no-fd-bootchk
1148 Disable boot signature checking for floppy disks in Bochs BIOS. It may
1149 be needed to boot from old floppy disks.
1150 TODO: check reference to Bochs BIOS.
1153 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1154 "-no-acpi disable ACPI\n", QEMU_ARCH_I386)
1158 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1159 it if your guest OS complains about ACPI problems (PC target machine
1163 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1164 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1168 Disable HPET support.
1171 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1172 "-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"
1173 " ACPI table description\n", QEMU_ARCH_I386)
1175 @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}]...]
1177 Add ACPI table with specified header fields and context from specified files.
1178 For file=, take whole ACPI table from the specified files, including all
1179 ACPI headers (possible overridden by other options).
1180 For data=, only data
1181 portion of the table is used, all header information is specified in the
1185 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1186 "-smbios file=binary\n"
1187 " load SMBIOS entry from binary file\n"
1188 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1189 " specify SMBIOS type 0 fields\n"
1190 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1191 " [,uuid=uuid][,sku=str][,family=str]\n"
1192 " specify SMBIOS type 1 fields\n", QEMU_ARCH_I386)
1194 @item -smbios file=@var{binary}
1196 Load SMBIOS entry from binary file.
1198 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}]
1200 Specify SMBIOS type 0 fields
1202 @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}]
1203 Specify SMBIOS type 1 fields
1211 DEFHEADING(Network options:)
1216 HXCOMM Legacy slirp options (now moved to -net user):
1218 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1219 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1220 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1222 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1226 DEF("net", HAS_ARG, QEMU_OPTION_net,
1227 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1228 " create a new Network Interface Card and connect it to VLAN 'n
'\n"
1230 "-net user[,vlan=n][,name=str][,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
1231 " [,hostname=host][,dhcpstart=addr][,dns=addr][,tftp=dir][,bootfile=f]\n"
1232 " [,hostfwd=rule][,guestfwd=rule]"
1234 "[,smb=dir[,smbserver=addr]]\n"
1236 " connect the user mode network stack to VLAN 'n
', configure its\n"
1237 " DHCP server and enabled optional services\n"
1240 "-net tap[,vlan=n][,name=str],ifname=name\n"
1241 " connect the host TAP network interface to VLAN 'n
'\n"
1243 "-net tap[,vlan=n][,name=str][,fd=h][,ifname=name][,script=file][,downscript=dfile][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off][,vhostfd=h][,vhostforce=on|off]\n"
1244 " connect the host TAP network interface to VLAN 'n
' \n"
1245 " use network scripts 'file
' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1246 " to configure it and 'dfile
' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1247 " to deconfigure it\n"
1248 " use '[down
]script
=no
' to disable script execution\n"
1249 " use network helper 'helper
' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1251 " use 'fd
=h
' to connect to an already opened TAP interface\n"
1252 " use 'sndbuf
=nbytes
' to limit the size of the send buffer (the\n"
1253 " default is disabled 'sndbuf
=0' to enable flow control set 'sndbuf
=1048576')\n"
1254 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1255 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1256 " use vhost=on to enable experimental in kernel accelerator\n"
1257 " (only has effect for virtio guests which use MSIX)\n"
1258 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1259 " use 'vhostfd
=h
' to connect to an already opened vhost net device\n"
1260 "-net bridge[,vlan=n][,name=str][,br=bridge][,helper=helper]\n"
1261 " connects a host TAP network interface to a host bridge device 'br
'\n"
1262 " (default=" DEFAULT_BRIDGE_INTERFACE ") using the program 'helper
'\n"
1263 " (default=" DEFAULT_BRIDGE_HELPER ")\n"
1265 "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
1266 " connect the vlan 'n
' to another VLAN using a socket connection\n"
1267 "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1268 " connect the vlan 'n
' to multicast maddr and port\n"
1269 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1270 "-net socket[,vlan=n][,name=str][,fd=h][,udp=host:port][,localaddr=host:port]\n"
1271 " connect the vlan 'n
' to another VLAN using an UDP tunnel\n"
1273 "-net vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1274 " connect the vlan 'n
' to port 'n
' of a vde switch running\n"
1275 " on host and listening for incoming connections on 'socketpath
'.\n"
1276 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1277 " ownership and permissions for communication port.\n"
1279 "-net dump[,vlan=n][,file=f][,len=n]\n"
1280 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
1281 "-net none use it alone to have zero network devices. If no -net option\n"
1282 " is provided, the default is '-net nic
-net user
'\n", QEMU_ARCH_ALL)
1283 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1293 "socket],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
1295 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1297 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1298 = 0 is the default). The NIC is an e1000 by default on the PC
1299 target. Optionally, the MAC address can be changed to @var{mac}, the
1300 device address set to @var{addr} (PCI cards only),
1301 and a @var{name} can be assigned for use in monitor commands.
1302 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1303 that the card should have; this option currently only affects virtio cards; set
1304 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1305 NIC is created. Qemu can emulate several different models of network card.
1306 Valid values for @var{type} are
1307 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1308 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1309 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1310 Not all devices are supported on all targets. Use -net nic,model=?
1311 for a list of available devices for your target.
1313 @item -net user[,@var{option}][,@var{option}][,...]
1314 Use the user mode network stack which requires no administrator
1315 privilege to run. Valid options are:
1319 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1321 @item name=@var{name}
1322 Assign symbolic name for use in monitor commands.
1324 @item net=@var{addr}[/@var{mask}]
1325 Set IP network address the guest will see. Optionally specify the netmask,
1326 either in the form a.b.c.d or as number of valid top-most bits. Default is
1329 @item host=@var{addr}
1330 Specify the guest-visible address of the host. Default is the 2nd IP in the
1331 guest network, i.e. x.x.x.2.
1333 @item restrict=on|off
1334 If this option is enabled, the guest will be isolated, i.e. it will not be
1335 able to contact the host and no guest IP packets will be routed over the host
1336 to the outside. This option does not affect any explicitly set forwarding rules.
1338 @item hostname=@var{name}
1339 Specifies the client hostname reported by the builtin DHCP server.
1341 @item dhcpstart=@var{addr}
1342 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1343 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1345 @item dns=@var{addr}
1346 Specify the guest-visible address of the virtual nameserver. The address must
1347 be different from the host address. Default is the 3rd IP in the guest network,
1350 @item tftp=@var{dir}
1351 When using the user mode network stack, activate a built-in TFTP
1352 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1353 The TFTP client on the guest must be configured in binary mode (use the command
1354 @code{bin} of the Unix TFTP client).
1356 @item bootfile=@var{file}
1357 When using the user mode network stack, broadcast @var{file} as the BOOTP
1358 filename. In conjunction with @option{tftp}, this can be used to network boot
1359 a guest from a local directory.
1361 Example (using pxelinux):
1363 qemu -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1366 @item smb=@var{dir}[,smbserver=@var{addr}]
1367 When using the user mode network stack, activate a built-in SMB
1368 server so that Windows OSes can access to the host files in @file{@var{dir}}
1369 transparently. The IP address of the SMB server can be set to @var{addr}. By
1370 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1372 In the guest Windows OS, the line:
1376 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1377 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1379 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1381 Note that a SAMBA server must be installed on the host OS.
1382 QEMU was tested successfully with smbd versions from Red Hat 9,
1383 Fedora Core 3 and OpenSUSE 11.x.
1385 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1386 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1387 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1388 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1389 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1390 be bound to a specific host interface. If no connection type is set, TCP is
1391 used. This option can be given multiple times.
1393 For example, to redirect host X11 connection from screen 1 to guest
1394 screen 0, use the following:
1398 qemu -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1399 # this host xterm should open in the guest X11 server
1403 To redirect telnet connections from host port 5555 to telnet port on
1404 the guest, use the following:
1408 qemu -net user,hostfwd=tcp::5555-:23 [...]
1409 telnet localhost 5555
1412 Then when you use on the host @code{telnet localhost 5555}, you
1413 connect to the guest telnet server.
1415 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1416 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1417 to the character device @var{dev}. This option can be given multiple times.
1421 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1422 processed and applied to -net user. Mixing them with the new configuration
1423 syntax gives undefined results. Their use for new applications is discouraged
1424 as they will be removed from future versions.
1426 @item -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1427 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1429 Use the network script @var{file} to configure it and the network script
1430 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1431 automatically provides one. The default network configure script is
1432 @file{/etc/qemu-ifup} and the default network deconfigure script is
1433 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1434 to disable script execution.
1436 If running QEMU as an unprivileged user, use the network helper
1437 @var{helper} to configure the TAP interface. The default network
1438 helper executable is @file{/usr/local/libexec/qemu-bridge-helper}.
1440 @option{fd}=@var{h} can be used to specify the handle of an already
1441 opened host TAP interface.
1446 #launch a QEMU instance with the default network script
1447 qemu linux.img -net nic -net tap
1451 #launch a QEMU instance with two NICs, each one connected
1453 qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1454 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1458 #launch a QEMU instance with the default network helper to
1459 #connect a TAP device to bridge br0
1460 qemu linux.img -net nic -net tap,"helper=/usr/local/libexec/qemu-bridge-helper"
1463 @item -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1464 Connect a host TAP network interface to a host bridge device.
1466 Use the network helper @var{helper} to configure the TAP interface and
1467 attach it to the bridge. The default network helper executable is
1468 @file{/usr/local/libexec/qemu-bridge-helper} and the default bridge
1469 device is @file{br0}.
1474 #launch a QEMU instance with the default network helper to
1475 #connect a TAP device to bridge br0
1476 qemu linux.img -net bridge -net nic,model=virtio
1480 #launch a QEMU instance with the default network helper to
1481 #connect a TAP device to bridge qemubr0
1482 qemu linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1485 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1487 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1488 machine using a TCP socket connection. If @option{listen} is
1489 specified, QEMU waits for incoming connections on @var{port}
1490 (@var{host} is optional). @option{connect} is used to connect to
1491 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1492 specifies an already opened TCP socket.
1496 # launch a first QEMU instance
1497 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
1498 -net socket,listen=:1234
1499 # connect the VLAN 0 of this instance to the VLAN 0
1500 # of the first instance
1501 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
1502 -net socket,connect=127.0.0.1:1234
1505 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1507 Create a VLAN @var{n} shared with another QEMU virtual
1508 machines using a UDP multicast socket, effectively making a bus for
1509 every QEMU with same multicast address @var{maddr} and @var{port}.
1513 Several QEMU can be running on different hosts and share same bus (assuming
1514 correct multicast setup for these hosts).
1516 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1517 @url{http://user-mode-linux.sf.net}.
1519 Use @option{fd=h} to specify an already opened UDP multicast socket.
1524 # launch one QEMU instance
1525 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
1526 -net socket,mcast=230.0.0.1:1234
1527 # launch another QEMU instance on same "bus"
1528 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
1529 -net socket,mcast=230.0.0.1:1234
1530 # launch yet another QEMU instance on same "bus"
1531 qemu linux.img -net nic,macaddr=52:54:00:12:34:58 \
1532 -net socket,mcast=230.0.0.1:1234
1535 Example (User Mode Linux compat.):
1537 # launch QEMU instance (note mcast address selected
1539 qemu linux
.img
-net nic
,macaddr
=52:54:00:12:34:56 \
1540 -net socket
,mcast
=239.192.168.1:1102
1542 /path
/to
/linux ubd0
=/path
/to
/root_fs eth0
=mcast
1545 Example (send packets from host
's 1.2.3.4):
1547 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
1548 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
1551 @item -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
1552 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
1553 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
1554 and MODE @var{octalmode} to change default ownership and permissions for
1555 communication port. This option is only available if QEMU has been compiled
1556 with vde support enabled.
1561 vde_switch -F -sock /tmp/myswitch
1562 # launch QEMU instance
1563 qemu linux.img -net nic -net vde,sock=/tmp/myswitch
1566 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
1567 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
1568 At most @var{len} bytes (64k by default) per packet are stored. The file format is
1569 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
1572 Indicate that no network devices should be configured. It is used to
1573 override the default configuration (@option{-net nic -net user}) which
1574 is activated if no @option{-net} options are provided.
1581 DEFHEADING(Character device options:)
1583 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
1584 "-chardev null,id=id[,mux=on|off]\n"
1585 "-chardev socket,id=id[,host=host],port=host[,to=to][,ipv4][,ipv6][,nodelay]\n"
1586 " [,server][,nowait][,telnet][,mux=on|off] (tcp)\n"
1587 "-chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix)\n"
1588 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
1589 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
1590 "-chardev msmouse,id=id[,mux=on|off]\n"
1591 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
1593 "-chardev file,id=id,path=path[,mux=on|off]\n"
1594 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
1596 "-chardev console,id=id[,mux=on|off]\n"
1597 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1599 "-chardev pty,id=id[,mux=on|off]\n"
1600 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
1602 #ifdef CONFIG_BRLAPI
1603 "-chardev braille,id=id[,mux=on|off]\n"
1605 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
1606 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
1607 "-chardev tty,id=id,path=path[,mux=on|off]\n"
1609 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
1610 "-chardev parport,id=id,path=path[,mux=on|off]\n"
1612 #if defined(CONFIG_SPICE)
1613 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
1620 The general form of a character device option is:
1623 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
1641 The specific backend will determine the applicable options.
1643 All devices must have an id, which can be any string up to 127 characters long.
1644 It is used to uniquely identify this device in other command line directives.
1646 A character device may be used in multiplexing mode by multiple front-ends.
1647 The key sequence of @key{Control-a} and @key{c} will rotate the input focus
1648 between attached front-ends. Specify @option{mux=on} to enable this mode.
1650 Options to each backend are described below.
1652 @item -chardev null ,id=@var{id}
1653 A void device. This device will not emit any data, and will drop any data it
1654 receives. The null backend does not take any options.
1656 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet]
1658 Create a two-way stream socket, which can be either a TCP or a unix socket. A
1659 unix socket will be created if @option{path} is specified. Behaviour is
1660 undefined if TCP options are specified for a unix socket.
1662 @option{server} specifies that the socket shall be a listening socket.
1664 @option{nowait} specifies that QEMU should not block waiting for a client to
1665 connect to a listening socket.
1667 @option{telnet} specifies that traffic on the socket should interpret telnet
1670 TCP and unix socket options are given below:
1674 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
1676 @option{host} for a listening socket specifies the local address to be bound.
1677 For a connecting socket species the remote host to connect to. @option{host} is
1678 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
1680 @option{port} for a listening socket specifies the local port to be bound. For a
1681 connecting socket specifies the port on the remote host to connect to.
1682 @option{port} can be given as either a port number or a service name.
1683 @option{port} is required.
1685 @option{to} is only relevant to listening sockets. If it is specified, and
1686 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
1687 to and including @option{to} until it succeeds. @option{to} must be specified
1690 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1691 If neither is specified the socket may use either protocol.
1693 @option{nodelay} disables the Nagle algorithm.
1695 @item unix options: path=@var{path}
1697 @option{path} specifies the local path of the unix socket. @option{path} is
1702 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
1704 Sends all traffic from the guest to a remote host over UDP.
1706 @option{host} specifies the remote host to connect to. If not specified it
1707 defaults to @code{localhost}.
1709 @option{port} specifies the port on the remote host to connect to. @option{port}
1712 @option{localaddr} specifies the local address to bind to. If not specified it
1713 defaults to @code{0.0.0.0}.
1715 @option{localport} specifies the local port to bind to. If not specified any
1716 available local port will be used.
1718 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1719 If neither is specified the device may use either protocol.
1721 @item -chardev msmouse ,id=@var{id}
1723 Forward QEMU's emulated msmouse events to the guest
. @option
{msmouse
} does not
1726 @item
-chardev vc
,id
=@
var{id
} [[,width
=@
var{width
}] [,height
=@
var{height
}]] [[,cols
=@
var{cols
}] [,rows
=@
var{rows
}]]
1728 Connect to a QEMU text console
. @option
{vc
} may optionally be given a specific
1731 @option
{width
} and @option
{height
} specify the width and height respectively of
1732 the console
, in pixels
.
1734 @option
{cols
} and @option
{rows
} specify that the console be sized to fit a text
1735 console with the given dimensions
.
1737 @item
-chardev file
,id
=@
var{id
} ,path
=@
var{path
}
1739 Log all traffic received from the guest to a file
.
1741 @option
{path
} specifies the path of the file to be opened
. This file will be
1742 created
if it does not already exist
, and overwritten
if it does
. @option
{path
}
1745 @item
-chardev pipe
,id
=@
var{id
} ,path
=@
var{path
}
1747 Create a two
-way connection to the guest
. The behaviour differs slightly between
1748 Windows hosts and other hosts
:
1750 On Windows
, a single duplex pipe will be created at
1751 @file
{\\.pipe\@option
{path
}}.
1753 On other hosts
, 2 pipes will be created called @file
{@option
{path
}.in} and
1754 @file
{@option
{path
}.out
}. Data written to @file
{@option
{path
}.in} will be
1755 received by the guest
. Data written by the guest can be read from
1756 @file
{@option
{path
}.out
}. QEMU will not create these fifos
, and requires them to
1759 @option
{path
} forms part of the pipe path as described above
. @option
{path
} is
1762 @item
-chardev console
,id
=@
var{id
}
1764 Send traffic from the guest to QEMU
's standard output. @option{console} does not
1767 @option{console} is only available on Windows hosts.
1769 @item -chardev serial ,id=@var{id} ,path=@option{path}
1771 Send traffic from the guest to a serial device on the host.
1774 only available on Windows hosts.
1776 @option{path} specifies the name of the serial device to open.
1778 @item -chardev pty ,id=@var{id}
1780 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
1781 not take any options.
1783 @option{pty} is not available on Windows hosts.
1785 @item -chardev stdio ,id=@var{id} [,signal=on|off]
1786 Connect to standard input and standard output of the qemu process.
1788 @option{signal} controls if signals are enabled on the terminal, that includes
1789 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
1790 default, use @option{signal=off} to disable it.
1792 @option{stdio} is not available on Windows hosts.
1794 @item -chardev braille ,id=@var{id}
1796 Connect to a local BrlAPI server. @option{braille} does not take any options.
1798 @item -chardev tty ,id=@var{id} ,path=@var{path}
1800 Connect to a local tty device.
1802 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
1805 @option{path} specifies the path to the tty. @option{path} is required.
1807 @item -chardev parport ,id=@var{id} ,path=@var{path}
1809 @option{parport} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
1811 Connect to a local parallel port.
1813 @option{path} specifies the path to the parallel port device. @option{path} is
1816 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
1818 @option{spicevmc} is only available when spice support is built in.
1820 @option{debug} debug level for spicevmc
1822 @option{name} name of spice channel to connect to
1824 Connect to a spice virtual machine channel, such as vdiport.
1832 DEFHEADING(Device URL Syntax:)
1834 In addition to using normal file images for the emulated storage devices,
1835 QEMU can also use networked resources such as iSCSI devices. These are
1836 specified using a special URL syntax.
1840 iSCSI support allows QEMU to access iSCSI resources directly and use as
1841 images for the guest storage. Both disk and cdrom images are supported.
1843 Syntax for specifying iSCSI LUNs is
1844 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
1846 Example (without authentication):
1848 qemu -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
1849 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
1850 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
1853 Example (CHAP username/password via URL):
1855 qemu -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
1858 Example (CHAP username/password via environment variables):
1860 LIBISCSI_CHAP_USERNAME="user" \
1861 LIBISCSI_CHAP_PASSWORD="password" \
1862 qemu -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
1865 iSCSI support is an optional feature of QEMU and only available when
1866 compiled and linked against libiscsi.
1868 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1869 "-iscsi [user=user][,password=password]\n"
1870 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1871 " [,initiator-name=iqn]\n"
1872 " iSCSI session parameters\n", QEMU_ARCH_ALL)
1876 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
1877 as Unix Domain Sockets.
1879 Syntax for specifying a NBD device using TCP
1880 ``nbd:<server-ip>:<port>[:exportname=<export>]''
1882 Syntax for specifying a NBD device using Unix Domain Sockets
1883 ``nbd:unix:<domain-socket>[:exportname=<export>]''
1888 qemu --drive file=nbd:192.0.2.1:30000
1891 Example for Unix Domain Sockets
1893 qemu --drive file=nbd:unix:/tmp/nbd-socket
1897 Sheepdog is a distributed storage system for QEMU.
1898 QEMU supports using either local sheepdog devices or remote networked
1901 Syntax for specifying a sheepdog device
1903 ``sheepdog:<vdiname>''
1905 ``sheepdog:<vdiname>:<snapid>''
1907 ``sheepdog:<vdiname>:<tag>''
1909 ``sheepdog:<host>:<port>:<vdiname>''
1911 ``sheepdog:<host>:<port>:<vdiname>:<snapid>''
1913 ``sheepdog:<host>:<port>:<vdiname>:<tag>''
1918 qemu --drive file=sheepdog:192.0.2.1:30000:MyVirtualMachine
1921 See also @url{http://http://www.osrg.net/sheepdog/}.
1926 DEFHEADING(Bluetooth(R) options:)
1928 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
1929 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands
\n" \
1930 "-bt hci
,host
[:id
]\n" \
1931 " use host
's HCI with the given name\n" \
1932 "-bt hci[,vlan=n]\n" \
1933 " emulate a standard HCI in virtual scatternet 'n
'\n" \
1934 "-bt vhci[,vlan=n]\n" \
1935 " add host computer to virtual scatternet 'n
' using VHCI\n" \
1936 "-bt device:dev[,vlan=n]\n" \
1937 " emulate a bluetooth device 'dev
' in scatternet 'n
'\n",
1944 Defines the function of the corresponding Bluetooth HCI. -bt options
1945 are matched with the HCIs present in the chosen machine type. For
1946 example when emulating a machine with only one HCI built into it, only
1947 the first @code{-bt hci[...]} option is valid and defines the HCI's
1948 logic
. The Transport Layer is decided by the machine type
. Currently
1949 the machines @code
{n800
} and @code
{n810
} have one HCI and all other
1953 The following three types are recognized
:
1957 (default) The corresponding Bluetooth HCI assumes no internal logic
1958 and will not respond to any HCI commands or emit events
.
1960 @item
-bt hci
,host
[:@
var{id
}]
1961 (@code
{bluez
} only
) The corresponding HCI passes commands
/ events
1962 to
/ from the physical HCI identified by the name @
var{id
} (default:
1963 @code
{hci0
}) on the computer running QEMU
. Only available on @code
{bluez
}
1964 capable systems like Linux
.
1966 @item
-bt hci
[,vlan
=@
var{n
}]
1967 Add a virtual
, standard HCI that will participate
in the Bluetooth
1968 scatternet @
var{n
} (default @code
{0}). Similarly to @option
{-net
}
1969 VLANs
, devices inside a bluetooth network @
var{n
} can only communicate
1970 with other devices
in the same
network (scatternet
).
1973 @item
-bt vhci
[,vlan
=@
var{n
}]
1974 (Linux
-host only
) Create a HCI
in scatternet @
var{n
} (default 0) attached
1975 to the host bluetooth stack instead of to the emulated target
. This
1976 allows the host and target machines to participate
in a common scatternet
1977 and communicate
. Requires the Linux @code
{vhci
} driver installed
. Can
1978 be used as following
:
1981 qemu
[...OPTIONS
...] -bt hci
,vlan
=5 -bt vhci
,vlan
=5
1984 @item
-bt device
:@
var{dev
}[,vlan
=@
var{n
}]
1985 Emulate a bluetooth device @
var{dev
} and place it
in network @
var{n
}
1986 (default @code
{0}). QEMU can only emulate one type of bluetooth devices
1991 Virtual wireless keyboard implementing the HIDP bluetooth profile
.
1998 DEFHEADING(Linux
/Multiboot boot specific
:)
2001 When
using these options
, you can use a given Linux or Multiboot
2002 kernel without installing it
in the disk image
. It can be useful
2003 for easier testing of various kernels
.
2008 DEF("kernel", HAS_ARG
, QEMU_OPTION_kernel
, \
2009 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL
)
2011 @item
-kernel @
var{bzImage
}
2013 Use @
var{bzImage
} as kernel image
. The kernel can be either a Linux kernel
2014 or
in multiboot format
.
2017 DEF("append", HAS_ARG
, QEMU_OPTION_append
, \
2018 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL
)
2020 @item
-append @
var{cmdline
}
2022 Use @
var{cmdline
} as kernel command line
2025 DEF("initrd", HAS_ARG
, QEMU_OPTION_initrd
, \
2026 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL
)
2028 @item
-initrd @
var{file
}
2030 Use @
var{file
} as initial ram disk
.
2032 @item
-initrd
"@var{file1} arg=foo,@var{file2}"
2034 This syntax is only available with multiboot
.
2036 Use @
var{file1
} and @
var{file2
} as modules and pass arg
=foo as parameter to the
2040 DEF("dtb", HAS_ARG
, QEMU_OPTION_dtb
, \
2041 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ARM
)
2043 @item
-dtb @
var{file
}
2045 Use @
var{file
} as a device tree
binary (dtb
) image and pass it to the kernel
2055 DEFHEADING(Debug
/Expert options
:)
2061 DEF("serial", HAS_ARG
, QEMU_OPTION_serial
, \
2062 "-serial dev redirect the serial port to char device 'dev'\n",
2065 @item
-serial @
var{dev
}
2067 Redirect the virtual serial port to host character device
2068 @
var{dev
}. The
default device is @code
{vc
} in graphical mode and
2069 @code
{stdio
} in non graphical mode
.
2071 This option can be used several times to simulate up to
4 serial
2074 Use @code
{-serial none
} to disable all serial ports
.
2076 Available character devices are
:
2078 @item vc
[:@
var{W
}x@
var{H
}]
2079 Virtual console
. Optionally
, a width and height can be given
in pixel with
2083 It is also possible to specify width or height
in characters
:
2088 [Linux only
] Pseudo
TTY (a
new PTY is automatically allocated
)
2090 No device is allocated
.
2094 [Linux only
] Use host tty
, e
.g
. @file
{/dev
/ttyS0
}. The host serial port
2095 parameters are set according to the emulated ones
.
2096 @item
/dev
/parport@
var{N
}
2097 [Linux only
, parallel port only
] Use host parallel port
2098 @
var{N
}. Currently SPP and EPP parallel port features can be used
.
2099 @item file
:@
var{filename
}
2100 Write output to @
var{filename
}. No character can be read
.
2102 [Unix only
] standard input
/output
2103 @item pipe
:@
var{filename
}
2104 name pipe @
var{filename
}
2106 [Windows only
] Use host serial port @
var{n
}
2107 @item udp
:[@
var{remote_host
}]:@
var{remote_port
}[@@
[@
var{src_ip
}]:@
var{src_port
}]
2108 This
implements UDP Net Console
.
2109 When @
var{remote_host
} or @
var{src_ip
} are not specified
2110 they
default to @code
{0.0.0.0}.
2111 When not
using a specified @
var{src_port
} a random port is automatically chosen
.
2113 If you just want a simple readonly console you can use @code
{netcat
} or
2114 @code
{nc
}, by starting qemu with
: @code
{-serial udp
::4555} and nc as
:
2115 @code
{nc
-u
-l
-p
4555}. Any time qemu writes something to that port it
2116 will appear
in the netconsole session
.
2118 If you plan to send characters back via netconsole or you want to stop
2119 and start qemu a lot of times
, you should have qemu use the same
2120 source port each time by
using something like @code
{-serial
2121 udp
::4555@@
:4556} to qemu
. Another approach is to use a patched
2122 version of netcat which can listen to a TCP port and send and receive
2123 characters via udp
. If you have a patched version of netcat which
2124 activates telnet remote echo and single char transfer
, then you can
2125 use the following options to step up a netcat redirector to allow
2126 telnet on port
5555 to access the qemu port
.
2129 -serial udp
::4555@@
:4556
2130 @item netcat options
:
2131 -u
-P
4555 -L
0.0.0.0:4556 -t
-p
5555 -I
-T
2132 @item telnet options
:
2136 @item tcp
:[@
var{host
}]:@
var{port
}[,@
var{server
}][,nowait
][,nodelay
]
2137 The TCP Net Console has two modes of operation
. It can send the serial
2138 I
/O to a location or wait
for a connection from a location
. By
default
2139 the TCP Net Console is sent to @
var{host
} at the @
var{port
}. If you use
2140 the @
var{server
} option QEMU will wait
for a client socket application
2141 to connect to the port before continuing
, unless the @code
{nowait
}
2142 option was specified
. The @code
{nodelay
} option disables the Nagle buffering
2143 algorithm
. If @
var{host
} is omitted
, 0.0.0.0 is assumed
. Only
2144 one TCP connection at a time is accepted
. You can use @code
{telnet
} to
2145 connect to the corresponding character device
.
2147 @item Example to send tcp console to
192.168.0.2 port
4444
2148 -serial tcp
:192.168.0.2:4444
2149 @item Example to listen and wait on port
4444 for connection
2150 -serial tcp
::4444,server
2151 @item Example to not wait and listen on ip
192.168.0.100 port
4444
2152 -serial tcp
:192.168.0.100:4444,server
,nowait
2155 @item telnet
:@
var{host
}:@
var{port
}[,server
][,nowait
][,nodelay
]
2156 The telnet protocol is used instead of raw tcp sockets
. The options
2157 work the same as
if you had specified @code
{-serial tcp
}. The
2158 difference is that the port acts like a telnet server or client
using
2159 telnet option negotiation
. This will also allow you to send the
2160 MAGIC_SYSRQ sequence
if you use a telnet that supports sending the
break
2161 sequence
. Typically
in unix telnet you
do it with Control
-] and then
2162 type
"send break" followed by pressing the enter key
.
2164 @item unix
:@
var{path
}[,server
][,nowait
]
2165 A unix domain socket is used instead of a tcp socket
. The option works the
2166 same as
if you had specified @code
{-serial tcp
} except the unix domain socket
2167 @
var{path
} is used
for connections
.
2169 @item mon
:@
var{dev_string
}
2170 This is a special option to allow the monitor to be multiplexed onto
2171 another serial port
. The monitor is accessed with key sequence of
2172 @key
{Control
-a
} and then pressing @key
{c
}. See monitor access
2173 @ref
{pcsys_keys
} in the
-nographic section
for more keys
.
2174 @
var{dev_string
} should be any one of the serial devices specified
2175 above
. An example to multiplex the monitor onto a telnet server
2176 listening on port
4444 would be
:
2178 @item
-serial mon
:telnet
::4444,server
,nowait
2182 Braille device
. This will use BrlAPI to display the braille output on a real
2186 Three button serial mouse
. Configure the guest to use Microsoft protocol
.
2190 DEF("parallel", HAS_ARG
, QEMU_OPTION_parallel
, \
2191 "-parallel dev redirect the parallel port to char device 'dev'\n",
2194 @item
-parallel @
var{dev
}
2196 Redirect the virtual parallel port to host device @
var{dev
} (same
2197 devices as the serial port
). On Linux hosts
, @file
{/dev
/parportN
} can
2198 be used to use hardware devices connected on the corresponding host
2201 This option can be used several times to simulate up to
3 parallel
2204 Use @code
{-parallel none
} to disable all parallel ports
.
2207 DEF("monitor", HAS_ARG
, QEMU_OPTION_monitor
, \
2208 "-monitor dev redirect the monitor to char device 'dev'\n",
2211 @item
-monitor @
var{dev
}
2213 Redirect the monitor to host device @
var{dev
} (same devices as the
2215 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2218 DEF("qmp", HAS_ARG
, QEMU_OPTION_qmp
, \
2219 "-qmp dev like -monitor but opens in 'control' mode\n",
2222 @item
-qmp @
var{dev
}
2224 Like
-monitor but opens
in 'control' mode
.
2227 DEF("mon", HAS_ARG
, QEMU_OPTION_mon
, \
2228 "-mon chardev=[name][,mode=readline|control][,default]\n", QEMU_ARCH_ALL
)
2230 @item
-mon chardev
=[name
][,mode
=readline|control
][,default]
2232 Setup monitor on chardev @
var{name
}.
2235 DEF("debugcon", HAS_ARG
, QEMU_OPTION_debugcon
, \
2236 "-debugcon dev redirect the debug console to char device 'dev'\n",
2239 @item
-debugcon @
var{dev
}
2241 Redirect the debug console to host device @
var{dev
} (same devices as the
2242 serial port
). The debug console is an I
/O port which is typically port
2243 0xe9; writing to that I
/O port sends output to
this device
.
2244 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2248 DEF("pidfile", HAS_ARG
, QEMU_OPTION_pidfile
, \
2249 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL
)
2251 @item
-pidfile @
var{file
}
2253 Store the QEMU process PID
in @
var{file
}. It is useful
if you launch QEMU
2257 DEF("singlestep", 0, QEMU_OPTION_singlestep
, \
2258 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL
)
2262 Run the emulation
in single step mode
.
2265 DEF("S", 0, QEMU_OPTION_S
, \
2266 "-S freeze CPU at startup (use 'c' to start execution)\n",
2271 Do not start CPU at
startup (you must type
'c' in the monitor
).
2274 DEF("gdb", HAS_ARG
, QEMU_OPTION_gdb
, \
2275 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL
)
2277 @item
-gdb @
var{dev
}
2279 Wait
for gdb connection on device @
var{dev
} (@pxref
{gdb_usage
}). Typical
2280 connections will likely be TCP
-based
, but also UDP
, pseudo TTY
, or even
2281 stdio are reasonable use
case. The latter is allowing to start qemu from
2282 within gdb and establish the connection via a pipe
:
2284 (gdb
) target remote | exec qemu
-gdb stdio
...
2288 DEF("s", 0, QEMU_OPTION_s
, \
2289 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT
"\n",
2294 Shorthand
for -gdb tcp
::1234, i
.e
. open a gdbserver on TCP port
1234
2295 (@pxref
{gdb_usage
}).
2298 DEF("d", HAS_ARG
, QEMU_OPTION_d
, \
2299 "-d item1,... output log to /tmp/qemu.log (use -d ? for a list of log items)\n",
2304 Output log
in /tmp
/qemu
.log
2307 DEF("D", HAS_ARG
, QEMU_OPTION_D
, \
2308 "-D logfile output log to logfile (instead of the default /tmp/qemu.log)\n",
2313 Output log
in logfile instead of
/tmp
/qemu
.log
2316 DEF("hdachs", HAS_ARG
, QEMU_OPTION_hdachs
, \
2317 "-hdachs c,h,s[,t]\n" \
2318 " force hard disk 0 physical geometry and the optional BIOS\n" \
2319 " translation (t=none or lba) (usually qemu can guess them)\n",
2322 @item
-hdachs @
var{c
},@
var{h
},@
var{s
},[,@
var{t
}]
2324 Force hard disk
0 physical
geometry (1 <= @
var{c
} <= 16383, 1 <=
2325 @
var{h
} <= 16, 1 <= @
var{s
} <= 63) and optionally force the BIOS
2326 translation
mode (@
var{t
}=none
, lba or auto
). Usually QEMU can guess
2327 all those parameters
. This option is useful
for old MS
-DOS disk
2331 DEF("L", HAS_ARG
, QEMU_OPTION_L
, \
2332 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2337 Set the directory
for the BIOS
, VGA BIOS and keymaps
.
2340 DEF("bios", HAS_ARG
, QEMU_OPTION_bios
, \
2341 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL
)
2343 @item
-bios @
var{file
}
2345 Set the filename
for the BIOS
.
2348 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm
, \
2349 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL
)
2353 Enable KVM full virtualization support
. This option is only available
2354 if KVM support is enabled when compiling
.
2357 DEF("xen-domid", HAS_ARG
, QEMU_OPTION_xen_domid
,
2358 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL
)
2359 DEF("xen-create", 0, QEMU_OPTION_xen_create
,
2360 "-xen-create create domain using xen hypercalls, bypassing xend\n"
2361 " warning: should not be used when xend is in use\n",
2363 DEF("xen-attach", 0, QEMU_OPTION_xen_attach
,
2364 "-xen-attach attach to existing xen domain\n"
2365 " xend will use this when starting qemu\n",
2368 @item
-xen
-domid @
var{id
}
2370 Specify xen guest domain @
var{id
} (XEN only
).
2373 Create domain
using xen hypercalls
, bypassing xend
.
2374 Warning
: should not be used when xend is
in use (XEN only
).
2377 Attach to existing xen domain
.
2378 xend will use
this when starting
qemu (XEN only
).
2381 DEF("no-reboot", 0, QEMU_OPTION_no_reboot
, \
2382 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL
)
2386 Exit instead of rebooting
.
2389 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown
, \
2390 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL
)
2393 @findex
-no
-shutdown
2394 Don
't exit QEMU on guest shutdown, but instead only stop the emulation.
2395 This allows for instance switching to monitor to commit changes to the
2399 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
2400 "-loadvm [tag|id]\n" \
2401 " start right away with a saved state (loadvm in monitor)\n",
2404 @item -loadvm @var{file}
2406 Start right away with a saved state (@code{loadvm} in monitor)
2410 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
2411 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
2416 Daemonize the QEMU process after initialization. QEMU will not detach from
2417 standard IO until it is ready to receive connections on any of its devices.
2418 This option is a useful way for external programs to launch QEMU without having
2419 to cope with initialization race conditions.
2422 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
2423 "-option-rom rom load a file, rom, into the option ROM space\n",
2426 @item -option-rom @var{file}
2428 Load the contents of @var{file} as an option ROM.
2429 This option is useful to load things like EtherBoot.
2432 DEF("clock", HAS_ARG, QEMU_OPTION_clock, \
2433 "-clock force the use of the given methods for timer alarm.\n" \
2434 " To see what timers are available use -clock ?\n",
2437 @item -clock @var{method}
2439 Force the use of the given methods for timer alarm. To see what timers
2440 are available use -clock ?.
2443 HXCOMM Options deprecated by -rtc
2444 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
2445 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
2447 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
2448 "-rtc [base=utc|localtime|date][,clock=host|vm][,driftfix=none|slew]\n" \
2449 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
2454 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
2456 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
2457 UTC or local time, respectively. @code{localtime} is required for correct date in
2458 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
2459 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
2461 By default the RTC is driven by the host system time. This allows to use the
2462 RTC as accurate reference clock inside the guest, specifically if the host
2463 time is smoothly following an accurate external reference clock, e.g. via NTP.
2464 If you want to isolate the guest time from the host, even prevent it from
2465 progressing during suspension, you can set @option{clock} to @code{vm} instead.
2467 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
2468 specifically with Windows' ACPI HAL
. This option will
try to figure out how
2469 many timer interrupts were not processed by the Windows guest and will
2473 DEF("icount", HAS_ARG
, QEMU_OPTION_icount
, \
2474 "-icount [N|auto]\n" \
2475 " enable virtual instruction counter with 2^N clock ticks per\n" \
2476 " instruction\n", QEMU_ARCH_ALL
)
2478 @item
-icount
[@
var{N
}|auto
]
2480 Enable virtual instruction counter
. The virtual cpu will execute one
2481 instruction every
2^@
var{N
} ns of virtual time
. If @code
{auto
} is specified
2482 then the virtual cpu speed will be automatically adjusted to keep virtual
2483 time within a few seconds of real time
.
2485 Note that
while this option can give deterministic behavior
, it does not
2486 provide cycle accurate emulation
. Modern CPUs contain superscalar out of
2487 order cores with complex cache hierarchies
. The number of instructions
2488 executed often has little or no correlation with actual performance
.
2491 DEF("watchdog", HAS_ARG
, QEMU_OPTION_watchdog
, \
2492 "-watchdog i6300esb|ib700\n" \
2493 " enable virtual hardware watchdog [default=none]\n",
2496 @item
-watchdog @
var{model
}
2498 Create a virtual hardware watchdog device
. Once
enabled (by a guest
2499 action
), the watchdog must be periodically polled by an agent inside
2500 the guest or
else the guest will be restarted
.
2502 The @
var{model
} is the model of hardware watchdog to emulate
. Choices
2503 for model are
: @code
{ib700
} (iBASE
700) which is a very simple ISA
2504 watchdog with a single timer
, or @code
{i6300esb
} (Intel
6300ESB I
/O
2505 controller hub
) which is a much more featureful PCI
-based dual
-timer
2506 watchdog
. Choose a model
for which your guest has drivers
.
2508 Use @code
{-watchdog ?
} to list available hardware models
. Only one
2509 watchdog can be enabled
for a guest
.
2512 DEF("watchdog-action", HAS_ARG
, QEMU_OPTION_watchdog_action
, \
2513 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
2514 " action when watchdog fires [default=reset]\n",
2517 @item
-watchdog
-action @
var{action
}
2519 The @
var{action
} controls what QEMU will
do when the watchdog timer
2522 @code
{reset
} (forcefully reset the guest
).
2523 Other possible actions are
:
2524 @code
{shutdown
} (attempt to gracefully shutdown the guest
),
2525 @code
{poweroff
} (forcefully poweroff the guest
),
2526 @code
{pause
} (pause the guest
),
2527 @code
{debug
} (print a debug message and
continue), or
2528 @code
{none
} (do nothing
).
2530 Note that the @code
{shutdown
} action requires that the guest responds
2531 to ACPI signals
, which it may not be able to
do in the sort of
2532 situations where the watchdog would have expired
, and thus
2533 @code
{-watchdog
-action shutdown
} is not recommended
for production use
.
2538 @item
-watchdog i6300esb
-watchdog
-action pause
2539 @item
-watchdog ib700
2543 DEF("echr", HAS_ARG
, QEMU_OPTION_echr
, \
2544 "-echr chr set terminal escape character instead of ctrl-a\n",
2548 @item
-echr @
var{numeric_ascii_value
}
2550 Change the escape character used
for switching to the monitor when
using
2551 monitor and serial sharing
. The
default is @code
{0x01} when
using the
2552 @code
{-nographic
} option
. @code
{0x01} is equal to pressing
2553 @code
{Control
-a
}. You can select a different character from the ascii
2554 control keys where
1 through
26 map to Control
-a through Control
-z
. For
2555 instance you could use the either of the following to change the escape
2556 character to Control
-t
.
2563 DEF("virtioconsole", HAS_ARG
, QEMU_OPTION_virtiocon
, \
2564 "-virtioconsole c\n" \
2565 " set virtio console\n", QEMU_ARCH_ALL
)
2567 @item
-virtioconsole @
var{c
}
2568 @findex
-virtioconsole
2571 This option is maintained
for backward compatibility
.
2573 Please use @code
{-device virtconsole
} for the
new way of invocation
.
2576 DEF("show-cursor", 0, QEMU_OPTION_show_cursor
, \
2577 "-show-cursor show cursor\n", QEMU_ARCH_ALL
)
2580 @findex
-show
-cursor
2584 DEF("tb-size", HAS_ARG
, QEMU_OPTION_tb_size
, \
2585 "-tb-size n set TB size\n", QEMU_ARCH_ALL
)
2587 @item
-tb
-size @
var{n
}
2592 DEF("incoming", HAS_ARG
, QEMU_OPTION_incoming
, \
2593 "-incoming p prepare for incoming migration, listen on port p\n",
2596 @item
-incoming @
var{port
}
2598 Prepare
for incoming migration
, listen on @
var{port
}.
2601 DEF("nodefaults", 0, QEMU_OPTION_nodefaults
, \
2602 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL
)
2606 Don
't create default devices.
2610 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
2611 "-chroot dir chroot to dir just before starting the VM\n",
2615 @item -chroot @var{dir}
2617 Immediately before starting guest execution, chroot to the specified
2618 directory. Especially useful in combination with -runas.
2622 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
2623 "-runas user change to user id user just before starting the VM\n",
2627 @item -runas @var{user}
2629 Immediately before starting guest execution, drop root privileges, switching
2630 to the specified user.
2633 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
2634 "-prom-env variable=value\n"
2635 " set OpenBIOS nvram variables\n",
2636 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
2638 @item -prom-env @var{variable}=@var{value}
2640 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
2642 DEF("semihosting", 0, QEMU_OPTION_semihosting,
2643 "-semihosting semihosting mode\n", QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA)
2646 @findex -semihosting
2647 Semihosting mode (ARM, M68K, Xtensa only).
2649 DEF("old-param", 0, QEMU_OPTION_old_param,
2650 "-old-param old param mode\n", QEMU_ARCH_ARM)
2653 @findex -old-param (ARM)
2654 Old param mode (ARM only).
2657 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
2658 "-readconfig <file>\n", QEMU_ARCH_ALL)
2660 @item -readconfig @var{file}
2662 Read device configuration from @var{file}.
2664 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
2665 "-writeconfig <file>\n"
2666 " read/write config file\n", QEMU_ARCH_ALL)
2668 @item -writeconfig @var{file}
2669 @findex -writeconfig
2670 Write device configuration to @var{file}.
2672 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
2674 " do not load default config files at startup\n",
2678 @findex -nodefconfig
2679 Normally QEMU loads a configuration file from @var{sysconfdir}/qemu.conf and
2680 @var{sysconfdir}/target-@var{ARCH}.conf on startup. The @code{-nodefconfig}
2681 option will prevent QEMU from loading these configuration files at startup.
2683 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
2684 "-trace [events=<file>][,file=<file>]\n"
2685 " specify tracing options\n",
2688 HXCOMM This line is not accurate, as some sub-options are backend-specific but
2689 HXCOMM HX does not support conditional compilation of text.
2690 @item -trace [events=@var{file}][,file=@var{file}]
2693 Specify tracing options.
2696 @item events=@var{file}
2697 Immediately enable events listed in @var{file}.
2698 The file must contain one event name (as listed in the @var{trace-events} file)
2700 This option is only available if QEMU has been compiled with
2701 either @var{simple} or @var{stderr} tracing backend.
2702 @item file=@var{file}
2703 Log output traces to @var{file}.
2705 This option is only available if QEMU has been compiled with
2706 the @var{simple} tracing backend.
2710 HXCOMM This is the last statement. Insert new options before this line!