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
.prop
=value
\n"
292 " set a global
default for a driver property
\n",
295 @item -global @var{driver}.@var{prop}=@var{value}
297 Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
300 qemu -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk
303 In particular, you can use this to set driver properties for devices which are
304 created automatically by the machine model. To create a device which is not
305 created automatically and set properties on it, use -@option{device}.
308 DEF("mtdblock
", HAS_ARG, QEMU_OPTION_mtdblock,
309 "-mtdblock file use
'file' as on
-board Flash memory image
\n",
312 @item -mtdblock @var{file}
314 Use @var{file} as on-board Flash memory image.
317 DEF("sd
", HAS_ARG, QEMU_OPTION_sd,
318 "-sd file use
'file' as SecureDigital card image
\n", QEMU_ARCH_ALL)
322 Use @var{file} as SecureDigital card image.
325 DEF("pflash
", HAS_ARG, QEMU_OPTION_pflash,
326 "-pflash file use
'file' as a parallel flash image
\n", QEMU_ARCH_ALL)
328 @item -pflash @var{file}
330 Use @var{file} as a parallel flash image.
333 DEF("boot
", HAS_ARG, QEMU_OPTION_boot,
334 "-boot
[order
=drives
][,once
=drives
][,menu
=on|off
]\n"
335 " [,splash
=sp_name
][,splash
-time
=sp_time
]\n"
336 " 'drives': floppy (a
), hard
disk (c
), CD
-ROM (d
), network (n
)\n"
337 " 'sp_name': the file
's name that would be passed to bios as logo picture, if menu=on\n"
338 " 'sp_time
': the period that splash picture last if menu=on, unit is ms\n",
341 @item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}]
343 Specify boot order @var{drives} as a string of drive letters. Valid
344 drive letters depend on the target achitecture. The x86 PC uses: a, b
345 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
346 from network adapter 1-4), hard disk boot is the default. To apply a
347 particular boot order only on the first startup, specify it via
350 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
351 as firmware/BIOS supports them. The default is non-interactive boot.
353 A splash picture could be passed to bios, enabling user to show it as logo,
354 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
355 supports them. Currently Seabios for X86 system support it.
356 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
357 format(true color). The resolution should be supported by the SVGA mode, so
358 the recommended is 320x240, 640x480, 800x640.
361 # try to boot from network first, then from hard disk
363 # boot from CD-ROM first, switch back to default order after reboot
365 # boot with a splash picture for 5 seconds.
366 qemu -boot menu=on,splash=/root/boot.bmp,splash-time=5000
369 Note: The legacy format '-boot @
var{drives
}' is still supported but its
370 use is discouraged as it may be removed from future versions.
373 DEF("snapshot", 0, QEMU_OPTION_snapshot,
374 "-snapshot write to temporary files instead of disk image files\n",
379 Write to temporary files instead of disk image files. In this case,
380 the raw disk image you use is not written back. You can however force
381 the write back by pressing @key{C-a s} (@pxref{disk_images}).
384 DEF("m", HAS_ARG, QEMU_OPTION_m,
385 "-m megs set virtual RAM size to megs MB [default="
386 stringify(DEFAULT_RAM_SIZE) "]\n", QEMU_ARCH_ALL)
390 Set virtual RAM size to @var{megs} megabytes. Default is 128 MiB. Optionally,
391 a suffix of ``M'' or ``G'' can be used to signify a value in megabytes or
392 gigabytes respectively.
395 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
396 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
398 @item -mem-path @var{path}
399 Allocate guest RAM from a temporarily created file in @var{path}.
403 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
404 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
408 Preallocate memory when using -mem-path.
412 DEF("k", HAS_ARG, QEMU_OPTION_k,
413 "-k language use keyboard layout (for example 'fr
' for French)\n",
416 @item -k @var{language}
418 Use keyboard layout @var{language} (for example @code{fr} for
419 French). This option is only needed where it is not easy to get raw PC
420 keycodes (e.g. on Macs, with some X11 servers or with a VNC
421 display). You don't normally need to use it on PC
/Linux or PC
/Windows
424 The available layouts are
:
426 ar de
-ch es fo fr
-ca hu ja mk no pt
-br sv
427 da en
-gb et fr fr
-ch is lt nl pl ru th
428 de en
-us fi fr
-be hr it lv nl
-be pt sl tr
431 The
default is @code
{en
-us
}.
435 DEF("audio-help", 0, QEMU_OPTION_audio_help
,
436 "-audio-help print list of audio drivers and their options\n",
441 Will show the audio subsystem help
: list of drivers
, tunable
445 DEF("soundhw", HAS_ARG
, QEMU_OPTION_soundhw
,
446 "-soundhw c1,... enable audio support\n"
447 " and only specified sound cards (comma separated list)\n"
448 " use -soundhw ? to get the list of supported cards\n"
449 " use -soundhw all to enable all of them\n", QEMU_ARCH_ALL
)
451 @item
-soundhw @
var{card1
}[,@
var{card2
},...] or
-soundhw all
453 Enable audio and selected sound hardware
. Use ? to print all
454 available sound hardware
.
457 qemu
-soundhw sb16
,adlib disk
.img
458 qemu
-soundhw es1370 disk
.img
459 qemu
-soundhw ac97 disk
.img
460 qemu
-soundhw hda disk
.img
461 qemu
-soundhw all disk
.img
465 Note that Linux
's i810_audio OSS kernel (for AC97) module might
466 require manually specifying clocking.
469 modprobe i810_audio clocking=48000
473 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
474 "-balloon none disable balloon device\n"
475 "-balloon virtio[,addr=str]\n"
476 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
480 Disable balloon device.
481 @item -balloon virtio[,addr=@var{addr}]
482 Enable virtio balloon device (default), optionally with PCI address
490 DEF("usb", 0, QEMU_OPTION_usb,
491 "-usb enable the USB driver (will be the default soon)\n",
499 Enable the USB driver (will be the default soon)
502 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
503 "-usbdevice name add the host or guest USB device 'name
'\n",
507 @item -usbdevice @var{devname}
509 Add the USB device @var{devname}. @xref{usb_devices}.
514 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
517 Pointer device that uses absolute coordinates (like a touchscreen). This
518 means qemu is able to report the mouse position without having to grab the
519 mouse. Also overrides the PS/2 mouse emulation when activated.
521 @item disk:[format=@var{format}]:@var{file}
522 Mass storage device based on file. The optional @var{format} argument
523 will be used rather than detecting the format. Can be used to specifiy
524 @code{format=raw} to avoid interpreting an untrusted format header.
526 @item host:@var{bus}.@var{addr}
527 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
529 @item host:@var{vendor_id}:@var{product_id}
530 Pass through the host device identified by @var{vendor_id}:@var{product_id}
533 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
534 Serial converter to host character device @var{dev}, see @code{-serial} for the
538 Braille device. This will use BrlAPI to display the braille output on a real
541 @item net:@var{options}
542 Network adapter that supports CDC ethernet and RNDIS protocols.
547 DEF("device", HAS_ARG, QEMU_OPTION_device,
548 "-device driver[,prop[=value][,...]]\n"
549 " add device (based on driver)\n"
550 " prop=value,... sets driver properties\n"
551 " use -device ? to print all possible drivers\n"
552 " use -device driver,? to print all possible properties\n",
555 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
557 Add device @var{driver}. @var{prop}=@var{value} sets driver
558 properties. Valid properties depend on the driver. To get help on
559 possible drivers and properties, use @code{-device ?} and
560 @code{-device @var{driver},?}.
565 DEFHEADING(File system options:)
567 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
568 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
569 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
574 @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}]
576 Define a new file system device. Valid options are:
579 This option specifies the fs driver backend to use.
580 Currently "local", "handle" and "proxy" file system drivers are supported.
582 Specifies identifier for this device
583 @item path=@var{path}
584 Specifies the export path for the file system device. Files under
585 this path will be available to the 9p client on the guest.
586 @item security_model=@var{security_model}
587 Specifies the security model to be used for this export path.
588 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
589 In "passthrough" security model, files are stored using the same
590 credentials as they are created on the guest. This requires qemu
591 to run as root. In "mapped-xattr" security model, some of the file
592 attributes like uid, gid, mode bits and link target are stored as
593 file attributes. For "mapped-file" these attributes are stored in the
594 hidden .virtfs_metadata directory. Directories exported by this security model cannot
595 interact with other unix tools. "none" security model is same as
596 passthrough except the sever won't report failures
if it fails to
597 set file attributes like ownership
. Security model is mandatory
598 only
for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take
599 security model as a parameter.
600 @item writeout=@var{writeout}
601 This is an optional argument. The only supported value is "immediate".
602 This means that host page cache will be used to read and write data but
603 write notification will be sent to the guest only when the data has been
604 reported as written by the storage subsystem.
606 Enables exporting 9p share as a readonly mount for guests. By default
607 read-write access is given.
608 @item socket=@var{socket}
609 Enables proxy filesystem driver to use passed socket file for communicating
610 with virtfs-proxy-helper
611 @item sock_fd=@var{sock_fd}
612 Enables proxy filesystem driver to use passed socket descriptor for
613 communicating with virtfs-proxy-helper. Usually a helper like libvirt
614 will create socketpair and pass one of the fds as sock_fd
617 -fsdev option is used along with -device driver "virtio-9p-pci".
618 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
619 Options for virtio-9p-pci driver are:
622 Specifies the id value specified along with -fsdev option
623 @item mount_tag=@var{mount_tag}
624 Specifies the tag name to be used by the guest to mount this export point
631 DEFHEADING(Virtual File system pass-through options:)
633 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
634 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
635 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
640 @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}]
643 The general form of a Virtual File system pass-through options are:
646 This option specifies the fs driver backend to use.
647 Currently "local", "handle" and "proxy" file system drivers are supported.
649 Specifies identifier for this device
650 @item path=@var{path}
651 Specifies the export path for the file system device. Files under
652 this path will be available to the 9p client on the guest.
653 @item security_model=@var{security_model}
654 Specifies the security model to be used for this export path.
655 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
656 In "passthrough" security model, files are stored using the same
657 credentials as they are created on the guest. This requires qemu
658 to run as root. In "mapped-xattr" security model, some of the file
659 attributes like uid, gid, mode bits and link target are stored as
660 file attributes. For "mapped-file" these attributes are stored in the
661 hidden .virtfs_metadata directory. Directories exported by this security model cannot
662 interact with other unix tools. "none" security model is same as
663 passthrough except the sever won't report failures
if it fails to
664 set file attributes like ownership
. Security model is mandatory only
665 for local fsdriver
. Other
fsdrivers (like handle
, proxy
) don
't take security
666 model as a parameter.
667 @item writeout=@var{writeout}
668 This is an optional argument. The only supported value is "immediate".
669 This means that host page cache will be used to read and write data but
670 write notification will be sent to the guest only when the data has been
671 reported as written by the storage subsystem.
673 Enables exporting 9p share as a readonly mount for guests. By default
674 read-write access is given.
675 @item socket=@var{socket}
676 Enables proxy filesystem driver to use passed socket file for
677 communicating with virtfs-proxy-helper. Usually a helper like libvirt
678 will create socketpair and pass one of the fds as sock_fd
680 Enables proxy filesystem driver to use passed 'sock_fd
' as the socket
681 descriptor for interfacing with virtfs-proxy-helper
685 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
686 "-virtfs_synth Create synthetic file system image\n",
690 @findex -virtfs_synth
691 Create synthetic file system image
696 DEF("name", HAS_ARG, QEMU_OPTION_name,
697 "-name string1[,process=string2]\n"
698 " set the name of the guest\n"
699 " string1 sets the window title and string2 the process name (on Linux)\n",
702 @item -name @var{name}
704 Sets the @var{name} of the guest.
705 This name will be displayed in the SDL window caption.
706 The @var{name} will also be used for the VNC server.
707 Also optionally set the top visible process name in Linux.
710 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
711 "-uuid %08x-%04x-%04x-%04x-%012x\n"
712 " specify machine UUID\n", QEMU_ARCH_ALL)
714 @item -uuid @var{uuid}
725 DEFHEADING(Display options:)
731 DEF("display", HAS_ARG, QEMU_OPTION_display,
732 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
733 " [,window_close=on|off]|curses|none|\n"
734 " vnc=<display>[,<optargs>]\n"
735 " select display type\n", QEMU_ARCH_ALL)
737 @item -display @var{type}
739 Select type of display to use. This option is a replacement for the
740 old style -sdl/-curses/... options. Valid values for @var{type} are
743 Display video output via SDL (usually in a separate graphics
744 window; see the SDL documentation for other possibilities).
746 Display video output via curses. For graphics device models which
747 support a text mode, QEMU can display this output using a
748 curses/ncurses interface. Nothing is displayed when the graphics
749 device is in graphical mode or if the graphics device does not support
750 a text mode. Generally only the VGA device models support text mode.
752 Do not display video output. The guest will still see an emulated
753 graphics card, but its output will not be displayed to the QEMU
754 user. This option differs from the -nographic option in that it
755 only affects what is done with video output; -nographic also changes
756 the destination of the serial and parallel port data.
758 Start a VNC server on display <arg>
762 DEF("nographic", 0, QEMU_OPTION_nographic,
763 "-nographic disable graphical output and redirect serial I/Os to console\n",
768 Normally, QEMU uses SDL to display the VGA output. With this option,
769 you can totally disable graphical output so that QEMU is a simple
770 command line application. The emulated serial port is redirected on
771 the console. Therefore, you can still use QEMU to debug a Linux kernel
772 with a serial console.
775 DEF("curses", 0, QEMU_OPTION_curses,
776 "-curses use a curses/ncurses interface instead of SDL\n",
781 Normally, QEMU uses SDL to display the VGA output. With this option,
782 QEMU can display the VGA output when in text mode using a
783 curses/ncurses interface. Nothing is displayed in graphical mode.
786 DEF("no-frame", 0, QEMU_OPTION_no_frame,
787 "-no-frame open SDL window without a frame and window decorations\n",
792 Do not use decorations for SDL windows and start them using the whole
793 available screen space. This makes the using QEMU in a dedicated desktop
794 workspace more convenient.
797 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
798 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
803 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
804 affects the special keys (for fullscreen, monitor-mode switching, etc).
807 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
808 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
813 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
814 affects the special keys (for fullscreen, monitor-mode switching, etc).
817 DEF("no-quit", 0, QEMU_OPTION_no_quit,
818 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
822 Disable SDL window close capability.
825 DEF("sdl", 0, QEMU_OPTION_sdl,
826 "-sdl enable SDL\n", QEMU_ARCH_ALL)
833 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
834 "-spice <args> enable spice\n", QEMU_ARCH_ALL)
836 @item -spice @var{option}[,@var{option}[,...]]
838 Enable the spice remote desktop protocol. Valid options are
843 Set the TCP port spice is listening on for plaintext channels.
846 Set the IP address spice is listening on. Default is any address.
850 Force using the specified IP version.
852 @item password=<secret>
853 Set the password you need to authenticate.
856 Require that the client use SASL to authenticate with the spice.
857 The exact choice of authentication method used is controlled from the
858 system / user's SASL configuration file
for the
'qemu' service
. This
859 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
860 unprivileged user
, an environment variable SASL_CONF_PATH can be used
861 to make it search alternate locations
for the service config
.
862 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
863 it is recommended that SASL always be combined with the
'tls' and
864 'x509' settings to enable use of SSL and server certificates
. This
865 ensures a data encryption preventing compromise of authentication
868 @item disable
-ticketing
869 Allow client connects without authentication
.
871 @item disable
-copy
-paste
872 Disable copy paste between the client and the guest
.
875 Set the TCP port spice is listening on
for encrypted channels
.
878 Set the x509 file directory
. Expects same filenames as
-vnc $display
,x509
=$dir
880 @item x509
-key
-file
=<file
>
881 @item x509
-key
-password
=<file
>
882 @item x509
-cert
-file
=<file
>
883 @item x509
-cacert
-file
=<file
>
884 @item x509
-dh
-key
-file
=<file
>
885 The x509 file names can also be configured individually
.
887 @item tls
-ciphers
=<list
>
888 Specify which ciphers to use
.
890 @item tls
-channel
=[main|display|cursor|inputs|record|playback
]
891 @item plaintext
-channel
=[main|display|cursor|inputs|record|playback
]
892 Force specific channel to be used with or without TLS encryption
. The
893 options can be specified multiple times to configure multiple
894 channels
. The special name
"default" can be used to set the
default
895 mode
. For channels which are not explicitly forced into one mode the
896 spice client is allowed to pick tls
/plaintext as he pleases
.
898 @item image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]
899 Configure image
compression (lossless
).
902 @item jpeg
-wan
-compression
=[auto|
never|always
]
903 @item zlib
-glz
-wan
-compression
=[auto|
never|always
]
904 Configure wan image
compression (lossy
for slow links
).
907 @item streaming
-video
=[off|all|filter
]
908 Configure video stream detection
. Default is filter
.
910 @item agent
-mouse
=[on|off
]
911 Enable
/disable passing mouse events via vdagent
. Default is on
.
913 @item playback
-compression
=[on|off
]
914 Enable
/disable audio stream
compression (using celt
0.5.1). Default is on
.
919 DEF("portrait", 0, QEMU_OPTION_portrait
,
920 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
925 Rotate graphical output
90 deg
left (only PXA LCD
).
928 DEF("rotate", HAS_ARG
, QEMU_OPTION_rotate
,
929 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
934 Rotate graphical output some deg
left (only PXA LCD
).
937 DEF("vga", HAS_ARG
, QEMU_OPTION_vga
,
938 "-vga [std|cirrus|vmware|qxl|xenfb|none]\n"
939 " select video card type\n", QEMU_ARCH_ALL
)
941 @item
-vga @
var{type
}
943 Select type of VGA card to emulate
. Valid values
for @
var{type
} are
946 Cirrus Logic GD5446 Video card
. All Windows versions starting from
947 Windows
95 should recognize and use
this graphic card
. For optimal
948 performances
, use
16 bit color depth
in the guest and the host OS
.
949 (This one is the
default)
951 Standard VGA card with Bochs VBE extensions
. If your guest OS
952 supports the VESA
2.0 VBE
extensions (e
.g
. Windows XP
) and
if you want
953 to use high resolution
modes (>= 1280x1024x16
) then you should use
956 VMWare SVGA
-II compatible adapter
. Use it
if you have sufficiently
957 recent XFree86
/XOrg server or Windows guest with a driver
for this
960 QXL paravirtual graphic card
. It is VGA
compatible (including VESA
961 2.0 VBE support
). Works best with qxl guest drivers installed though
.
962 Recommended choice when
using the spice protocol
.
968 DEF("full-screen", 0, QEMU_OPTION_full_screen
,
969 "-full-screen start in full screen\n", QEMU_ARCH_ALL
)
973 Start
in full screen
.
976 DEF("g", 1, QEMU_OPTION_g
,
977 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
978 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
980 @item
-g @
var{width
}x@
var{height
}[x@
var{depth
}]
982 Set the initial graphical resolution and
depth (PPC
, SPARC only
).
985 DEF("vnc", HAS_ARG
, QEMU_OPTION_vnc
,
986 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL
)
988 @item
-vnc @
var{display
}[,@
var{option
}[,@
var{option
}[,...]]]
990 Normally
, QEMU uses SDL to display the VGA output
. With
this option
,
991 you can have QEMU listen on VNC display @
var{display
} and redirect the VGA
992 display over the VNC session
. It is very useful to enable the usb
993 tablet device when
using this option (option @option
{-usbdevice
994 tablet
}). When
using the VNC display
, you must use the @option
{-k
}
995 parameter to set the keyboard layout
if you are not
using en
-us
. Valid
996 syntax
for the @
var{display
} is
1000 @item @
var{host
}:@
var{d
}
1002 TCP connections will only be allowed from @
var{host
} on display @
var{d
}.
1003 By convention the TCP port is
5900+@
var{d
}. Optionally
, @
var{host
} can
1004 be omitted
in which
case the server will accept connections from any host
.
1006 @item unix
:@
var{path
}
1008 Connections will be allowed over UNIX domain sockets where @
var{path
} is the
1009 location of a unix socket to listen
for connections on
.
1013 VNC is initialized but not started
. The monitor @code
{change
} command
1014 can be used to later start the VNC server
.
1018 Following the @
var{display
} value there may be one or more @
var{option
} flags
1019 separated by commas
. Valid options are
1025 Connect to a listening VNC client via a ``reverse
'' connection
. The
1026 client is specified by the @
var{display
}. For reverse network
1027 connections (@
var{host
}:@
var{d
},@code
{reverse
}), the @
var{d
} argument
1028 is a TCP port number
, not a display number
.
1032 Require that password based authentication is used
for client connections
.
1033 The password must be set separately
using the @code
{change
} command
in the
1038 Require that client use TLS when communicating with the VNC server
. This
1039 uses anonymous TLS credentials so is susceptible to a man
-in-the
-middle
1040 attack
. It is recommended that
this option be combined with either the
1041 @option
{x509
} or @option
{x509verify
} options
.
1043 @item x509
=@
var{/path
/to
/certificate
/dir
}
1045 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1046 for negotiating the TLS session
. The server will send its x509 certificate
1047 to the client
. It is recommended that a password be set on the VNC server
1048 to provide authentication of the client when
this is used
. The path following
1049 this option specifies where the x509 certificates are to be loaded from
.
1050 See the @ref
{vnc_security
} section
for details on generating certificates
.
1052 @item x509verify
=@
var{/path
/to
/certificate
/dir
}
1054 Valid
if @option
{tls
} is specified
. Require that x509 credentials are used
1055 for negotiating the TLS session
. The server will send its x509 certificate
1056 to the client
, and request that the client send its own x509 certificate
.
1057 The server will validate the client
's certificate against the CA certificate,
1058 and reject clients when validation fails. If the certificate authority is
1059 trusted, this is a sufficient authentication mechanism. You may still wish
1060 to set a password on the VNC server as a second authentication layer. The
1061 path following this option specifies where the x509 certificates are to
1062 be loaded from. See the @ref{vnc_security} section for details on generating
1067 Require that the client use SASL to authenticate with the VNC server.
1068 The exact choice of authentication method used is controlled from the
1069 system / user's SASL configuration file
for the
'qemu' service
. This
1070 is typically found
in /etc
/sasl2
/qemu
.conf
. If running QEMU as an
1071 unprivileged user
, an environment variable SASL_CONF_PATH can be used
1072 to make it search alternate locations
for the service config
.
1073 While some SASL auth methods can also provide data
encryption (eg GSSAPI
),
1074 it is recommended that SASL always be combined with the
'tls' and
1075 'x509' settings to enable use of SSL and server certificates
. This
1076 ensures a data encryption preventing compromise of authentication
1077 credentials
. See the @ref
{vnc_security
} section
for details on
using
1078 SASL authentication
.
1082 Turn on access control lists
for checking of the x509 client certificate
1083 and SASL party
. For x509 certs
, the ACL check is made against the
1084 certificate
's distinguished name. This is something that looks like
1085 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1086 made against the username, which depending on the SASL plugin, may
1087 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1088 When the @option{acl} flag is set, the initial access list will be
1089 empty, with a @code{deny} policy. Thus no one will be allowed to
1090 use the VNC server until the ACLs have been loaded. This can be
1091 achieved using the @code{acl} monitor command.
1095 Enable lossy compression methods (gradient, JPEG, ...). If this
1096 option is set, VNC client may receive lossy framebuffer updates
1097 depending on its encoding settings. Enabling this option can save
1098 a lot of bandwidth at the expense of quality.
1102 Disable adaptive encodings. Adaptive encodings are enabled by default.
1103 An adaptive encoding will try to detect frequently updated screen regions,
1104 and send updates in these regions using a lossy encoding (like JPEG).
1105 This can be really helpful to save bandwidth when playing videos. Disabling
1106 adaptive encodings allows to restore the original static behavior of encodings
1109 @item share=[allow-exclusive|force-shared|ignore]
1111 Set display sharing policy. 'allow
-exclusive
' allows clients to ask
1112 for exclusive access. As suggested by the rfb spec this is
1113 implemented by dropping other connections. Connecting multiple
1114 clients in parallel requires all clients asking for a shared session
1115 (vncviewer: -shared switch). This is the default. 'force
-shared
'
1116 disables exclusive client access. Useful for shared desktop sessions,
1117 where you don't want someone forgetting specify
-shared disconnect
1118 everybody
else. 'ignore' completely ignores the shared flag and
1119 allows everybody connect unconditionally
. Doesn
't conform to the rfb
1120 spec but is traditional qemu behavior.
1129 ARCHHEADING(, QEMU_ARCH_I386)
1131 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1136 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1137 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1142 Use it when installing Windows 2000 to avoid a disk full bug. After
1143 Windows 2000 is installed, you no longer need this option (this option
1144 slows down the IDE transfers).
1147 HXCOMM Deprecated by -rtc
1148 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1150 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1151 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1154 @item -no-fd-bootchk
1155 @findex -no-fd-bootchk
1156 Disable boot signature checking for floppy disks in Bochs BIOS. It may
1157 be needed to boot from old floppy disks.
1158 TODO: check reference to Bochs BIOS.
1161 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1162 "-no-acpi disable ACPI\n", QEMU_ARCH_I386)
1166 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1167 it if your guest OS complains about ACPI problems (PC target machine
1171 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1172 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1176 Disable HPET support.
1179 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1180 "-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"
1181 " ACPI table description\n", QEMU_ARCH_I386)
1183 @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}]...]
1185 Add ACPI table with specified header fields and context from specified files.
1186 For file=, take whole ACPI table from the specified files, including all
1187 ACPI headers (possible overridden by other options).
1188 For data=, only data
1189 portion of the table is used, all header information is specified in the
1193 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1194 "-smbios file=binary\n"
1195 " load SMBIOS entry from binary file\n"
1196 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1197 " specify SMBIOS type 0 fields\n"
1198 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1199 " [,uuid=uuid][,sku=str][,family=str]\n"
1200 " specify SMBIOS type 1 fields\n", QEMU_ARCH_I386)
1202 @item -smbios file=@var{binary}
1204 Load SMBIOS entry from binary file.
1206 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}]
1208 Specify SMBIOS type 0 fields
1210 @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}]
1211 Specify SMBIOS type 1 fields
1219 DEFHEADING(Network options:)
1224 HXCOMM Legacy slirp options (now moved to -net user):
1226 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1227 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1228 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1230 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1234 DEF("net", HAS_ARG, QEMU_OPTION_net,
1235 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1236 " create a new Network Interface Card and connect it to VLAN 'n
'\n"
1238 "-net user[,vlan=n][,name=str][,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
1239 " [,hostname=host][,dhcpstart=addr][,dns=addr][,tftp=dir][,bootfile=f]\n"
1240 " [,hostfwd=rule][,guestfwd=rule]"
1242 "[,smb=dir[,smbserver=addr]]\n"
1244 " connect the user mode network stack to VLAN 'n
', configure its\n"
1245 " DHCP server and enabled optional services\n"
1248 "-net tap[,vlan=n][,name=str],ifname=name\n"
1249 " connect the host TAP network interface to VLAN 'n
'\n"
1251 "-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"
1252 " connect the host TAP network interface to VLAN 'n
' \n"
1253 " use network scripts 'file
' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1254 " to configure it and 'dfile
' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1255 " to deconfigure it\n"
1256 " use '[down
]script
=no
' to disable script execution\n"
1257 " use network helper 'helper
' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1259 " use 'fd
=h
' to connect to an already opened TAP interface\n"
1260 " use 'sndbuf
=nbytes
' to limit the size of the send buffer (the\n"
1261 " default is disabled 'sndbuf
=0' to enable flow control set 'sndbuf
=1048576')\n"
1262 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1263 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1264 " use vhost=on to enable experimental in kernel accelerator\n"
1265 " (only has effect for virtio guests which use MSIX)\n"
1266 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1267 " use 'vhostfd
=h
' to connect to an already opened vhost net device\n"
1268 "-net bridge[,vlan=n][,name=str][,br=bridge][,helper=helper]\n"
1269 " connects a host TAP network interface to a host bridge device 'br
'\n"
1270 " (default=" DEFAULT_BRIDGE_INTERFACE ") using the program 'helper
'\n"
1271 " (default=" DEFAULT_BRIDGE_HELPER ")\n"
1273 "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
1274 " connect the vlan 'n
' to another VLAN using a socket connection\n"
1275 "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1276 " connect the vlan 'n
' to multicast maddr and port\n"
1277 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1278 "-net socket[,vlan=n][,name=str][,fd=h][,udp=host:port][,localaddr=host:port]\n"
1279 " connect the vlan 'n
' to another VLAN using an UDP tunnel\n"
1281 "-net vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1282 " connect the vlan 'n
' to port 'n
' of a vde switch running\n"
1283 " on host and listening for incoming connections on 'socketpath
'.\n"
1284 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1285 " ownership and permissions for communication port.\n"
1287 "-net dump[,vlan=n][,file=f][,len=n]\n"
1288 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
1289 "-net none use it alone to have zero network devices. If no -net option\n"
1290 " is provided, the default is '-net nic
-net user
'\n", QEMU_ARCH_ALL)
1291 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1301 "socket],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
1303 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1305 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1306 = 0 is the default). The NIC is an e1000 by default on the PC
1307 target. Optionally, the MAC address can be changed to @var{mac}, the
1308 device address set to @var{addr} (PCI cards only),
1309 and a @var{name} can be assigned for use in monitor commands.
1310 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1311 that the card should have; this option currently only affects virtio cards; set
1312 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1313 NIC is created. Qemu can emulate several different models of network card.
1314 Valid values for @var{type} are
1315 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1316 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1317 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1318 Not all devices are supported on all targets. Use -net nic,model=?
1319 for a list of available devices for your target.
1321 @item -net user[,@var{option}][,@var{option}][,...]
1322 Use the user mode network stack which requires no administrator
1323 privilege to run. Valid options are:
1327 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1329 @item name=@var{name}
1330 Assign symbolic name for use in monitor commands.
1332 @item net=@var{addr}[/@var{mask}]
1333 Set IP network address the guest will see. Optionally specify the netmask,
1334 either in the form a.b.c.d or as number of valid top-most bits. Default is
1337 @item host=@var{addr}
1338 Specify the guest-visible address of the host. Default is the 2nd IP in the
1339 guest network, i.e. x.x.x.2.
1341 @item restrict=on|off
1342 If this option is enabled, the guest will be isolated, i.e. it will not be
1343 able to contact the host and no guest IP packets will be routed over the host
1344 to the outside. This option does not affect any explicitly set forwarding rules.
1346 @item hostname=@var{name}
1347 Specifies the client hostname reported by the builtin DHCP server.
1349 @item dhcpstart=@var{addr}
1350 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1351 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1353 @item dns=@var{addr}
1354 Specify the guest-visible address of the virtual nameserver. The address must
1355 be different from the host address. Default is the 3rd IP in the guest network,
1358 @item tftp=@var{dir}
1359 When using the user mode network stack, activate a built-in TFTP
1360 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1361 The TFTP client on the guest must be configured in binary mode (use the command
1362 @code{bin} of the Unix TFTP client).
1364 @item bootfile=@var{file}
1365 When using the user mode network stack, broadcast @var{file} as the BOOTP
1366 filename. In conjunction with @option{tftp}, this can be used to network boot
1367 a guest from a local directory.
1369 Example (using pxelinux):
1371 qemu -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1374 @item smb=@var{dir}[,smbserver=@var{addr}]
1375 When using the user mode network stack, activate a built-in SMB
1376 server so that Windows OSes can access to the host files in @file{@var{dir}}
1377 transparently. The IP address of the SMB server can be set to @var{addr}. By
1378 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1380 In the guest Windows OS, the line:
1384 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1385 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1387 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1389 Note that a SAMBA server must be installed on the host OS.
1390 QEMU was tested successfully with smbd versions from Red Hat 9,
1391 Fedora Core 3 and OpenSUSE 11.x.
1393 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1394 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1395 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1396 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1397 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1398 be bound to a specific host interface. If no connection type is set, TCP is
1399 used. This option can be given multiple times.
1401 For example, to redirect host X11 connection from screen 1 to guest
1402 screen 0, use the following:
1406 qemu -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1407 # this host xterm should open in the guest X11 server
1411 To redirect telnet connections from host port 5555 to telnet port on
1412 the guest, use the following:
1416 qemu -net user,hostfwd=tcp::5555-:23 [...]
1417 telnet localhost 5555
1420 Then when you use on the host @code{telnet localhost 5555}, you
1421 connect to the guest telnet server.
1423 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1424 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1425 to the character device @var{dev}. This option can be given multiple times.
1429 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1430 processed and applied to -net user. Mixing them with the new configuration
1431 syntax gives undefined results. Their use for new applications is discouraged
1432 as they will be removed from future versions.
1434 @item -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1435 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1437 Use the network script @var{file} to configure it and the network script
1438 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1439 automatically provides one. The default network configure script is
1440 @file{/etc/qemu-ifup} and the default network deconfigure script is
1441 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1442 to disable script execution.
1444 If running QEMU as an unprivileged user, use the network helper
1445 @var{helper} to configure the TAP interface. The default network
1446 helper executable is @file{/usr/local/libexec/qemu-bridge-helper}.
1448 @option{fd}=@var{h} can be used to specify the handle of an already
1449 opened host TAP interface.
1454 #launch a QEMU instance with the default network script
1455 qemu linux.img -net nic -net tap
1459 #launch a QEMU instance with two NICs, each one connected
1461 qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1462 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1466 #launch a QEMU instance with the default network helper to
1467 #connect a TAP device to bridge br0
1468 qemu linux.img -net nic -net tap,"helper=/usr/local/libexec/qemu-bridge-helper"
1471 @item -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1472 Connect a host TAP network interface to a host bridge device.
1474 Use the network helper @var{helper} to configure the TAP interface and
1475 attach it to the bridge. The default network helper executable is
1476 @file{/usr/local/libexec/qemu-bridge-helper} and the default bridge
1477 device is @file{br0}.
1482 #launch a QEMU instance with the default network helper to
1483 #connect a TAP device to bridge br0
1484 qemu linux.img -net bridge -net nic,model=virtio
1488 #launch a QEMU instance with the default network helper to
1489 #connect a TAP device to bridge qemubr0
1490 qemu linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1493 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1495 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1496 machine using a TCP socket connection. If @option{listen} is
1497 specified, QEMU waits for incoming connections on @var{port}
1498 (@var{host} is optional). @option{connect} is used to connect to
1499 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1500 specifies an already opened TCP socket.
1504 # launch a first QEMU instance
1505 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
1506 -net socket,listen=:1234
1507 # connect the VLAN 0 of this instance to the VLAN 0
1508 # of the first instance
1509 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
1510 -net socket,connect=127.0.0.1:1234
1513 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1515 Create a VLAN @var{n} shared with another QEMU virtual
1516 machines using a UDP multicast socket, effectively making a bus for
1517 every QEMU with same multicast address @var{maddr} and @var{port}.
1521 Several QEMU can be running on different hosts and share same bus (assuming
1522 correct multicast setup for these hosts).
1524 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1525 @url{http://user-mode-linux.sf.net}.
1527 Use @option{fd=h} to specify an already opened UDP multicast socket.
1532 # launch one QEMU instance
1533 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
1534 -net socket,mcast=230.0.0.1:1234
1535 # launch another QEMU instance on same "bus"
1536 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
1537 -net socket,mcast=230.0.0.1:1234
1538 # launch yet another QEMU instance on same "bus"
1539 qemu linux.img -net nic,macaddr=52:54:00:12:34:58 \
1540 -net socket,mcast=230.0.0.1:1234
1543 Example (User Mode Linux compat.):
1545 # launch QEMU instance (note mcast address selected
1547 qemu linux
.img
-net nic
,macaddr
=52:54:00:12:34:56 \
1548 -net socket
,mcast
=239.192.168.1:1102
1550 /path
/to
/linux ubd0
=/path
/to
/root_fs eth0
=mcast
1553 Example (send packets from host
's 1.2.3.4):
1555 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
1556 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
1559 @item -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
1560 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
1561 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
1562 and MODE @var{octalmode} to change default ownership and permissions for
1563 communication port. This option is only available if QEMU has been compiled
1564 with vde support enabled.
1569 vde_switch -F -sock /tmp/myswitch
1570 # launch QEMU instance
1571 qemu linux.img -net nic -net vde,sock=/tmp/myswitch
1574 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
1575 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
1576 At most @var{len} bytes (64k by default) per packet are stored. The file format is
1577 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
1580 Indicate that no network devices should be configured. It is used to
1581 override the default configuration (@option{-net nic -net user}) which
1582 is activated if no @option{-net} options are provided.
1589 DEFHEADING(Character device options:)
1591 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
1592 "-chardev null,id=id[,mux=on|off]\n"
1593 "-chardev socket,id=id[,host=host],port=host[,to=to][,ipv4][,ipv6][,nodelay]\n"
1594 " [,server][,nowait][,telnet][,mux=on|off] (tcp)\n"
1595 "-chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix)\n"
1596 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
1597 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
1598 "-chardev msmouse,id=id[,mux=on|off]\n"
1599 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
1601 "-chardev file,id=id,path=path[,mux=on|off]\n"
1602 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
1604 "-chardev console,id=id[,mux=on|off]\n"
1605 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1607 "-chardev pty,id=id[,mux=on|off]\n"
1608 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
1610 #ifdef CONFIG_BRLAPI
1611 "-chardev braille,id=id[,mux=on|off]\n"
1613 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
1614 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
1615 "-chardev tty,id=id,path=path[,mux=on|off]\n"
1617 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
1618 "-chardev parport,id=id,path=path[,mux=on|off]\n"
1620 #if defined(CONFIG_SPICE)
1621 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
1628 The general form of a character device option is:
1631 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
1649 The specific backend will determine the applicable options.
1651 All devices must have an id, which can be any string up to 127 characters long.
1652 It is used to uniquely identify this device in other command line directives.
1654 A character device may be used in multiplexing mode by multiple front-ends.
1655 The key sequence of @key{Control-a} and @key{c} will rotate the input focus
1656 between attached front-ends. Specify @option{mux=on} to enable this mode.
1658 Options to each backend are described below.
1660 @item -chardev null ,id=@var{id}
1661 A void device. This device will not emit any data, and will drop any data it
1662 receives. The null backend does not take any options.
1664 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet]
1666 Create a two-way stream socket, which can be either a TCP or a unix socket. A
1667 unix socket will be created if @option{path} is specified. Behaviour is
1668 undefined if TCP options are specified for a unix socket.
1670 @option{server} specifies that the socket shall be a listening socket.
1672 @option{nowait} specifies that QEMU should not block waiting for a client to
1673 connect to a listening socket.
1675 @option{telnet} specifies that traffic on the socket should interpret telnet
1678 TCP and unix socket options are given below:
1682 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
1684 @option{host} for a listening socket specifies the local address to be bound.
1685 For a connecting socket species the remote host to connect to. @option{host} is
1686 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
1688 @option{port} for a listening socket specifies the local port to be bound. For a
1689 connecting socket specifies the port on the remote host to connect to.
1690 @option{port} can be given as either a port number or a service name.
1691 @option{port} is required.
1693 @option{to} is only relevant to listening sockets. If it is specified, and
1694 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
1695 to and including @option{to} until it succeeds. @option{to} must be specified
1698 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1699 If neither is specified the socket may use either protocol.
1701 @option{nodelay} disables the Nagle algorithm.
1703 @item unix options: path=@var{path}
1705 @option{path} specifies the local path of the unix socket. @option{path} is
1710 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
1712 Sends all traffic from the guest to a remote host over UDP.
1714 @option{host} specifies the remote host to connect to. If not specified it
1715 defaults to @code{localhost}.
1717 @option{port} specifies the port on the remote host to connect to. @option{port}
1720 @option{localaddr} specifies the local address to bind to. If not specified it
1721 defaults to @code{0.0.0.0}.
1723 @option{localport} specifies the local port to bind to. If not specified any
1724 available local port will be used.
1726 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1727 If neither is specified the device may use either protocol.
1729 @item -chardev msmouse ,id=@var{id}
1731 Forward QEMU's emulated msmouse events to the guest
. @option
{msmouse
} does not
1734 @item
-chardev vc
,id
=@
var{id
} [[,width
=@
var{width
}] [,height
=@
var{height
}]] [[,cols
=@
var{cols
}] [,rows
=@
var{rows
}]]
1736 Connect to a QEMU text console
. @option
{vc
} may optionally be given a specific
1739 @option
{width
} and @option
{height
} specify the width and height respectively of
1740 the console
, in pixels
.
1742 @option
{cols
} and @option
{rows
} specify that the console be sized to fit a text
1743 console with the given dimensions
.
1745 @item
-chardev file
,id
=@
var{id
} ,path
=@
var{path
}
1747 Log all traffic received from the guest to a file
.
1749 @option
{path
} specifies the path of the file to be opened
. This file will be
1750 created
if it does not already exist
, and overwritten
if it does
. @option
{path
}
1753 @item
-chardev pipe
,id
=@
var{id
} ,path
=@
var{path
}
1755 Create a two
-way connection to the guest
. The behaviour differs slightly between
1756 Windows hosts and other hosts
:
1758 On Windows
, a single duplex pipe will be created at
1759 @file
{\\.pipe\@option
{path
}}.
1761 On other hosts
, 2 pipes will be created called @file
{@option
{path
}.in} and
1762 @file
{@option
{path
}.out
}. Data written to @file
{@option
{path
}.in} will be
1763 received by the guest
. Data written by the guest can be read from
1764 @file
{@option
{path
}.out
}. QEMU will not create these fifos
, and requires them to
1767 @option
{path
} forms part of the pipe path as described above
. @option
{path
} is
1770 @item
-chardev console
,id
=@
var{id
}
1772 Send traffic from the guest to QEMU
's standard output. @option{console} does not
1775 @option{console} is only available on Windows hosts.
1777 @item -chardev serial ,id=@var{id} ,path=@option{path}
1779 Send traffic from the guest to a serial device on the host.
1782 only available on Windows hosts.
1784 @option{path} specifies the name of the serial device to open.
1786 @item -chardev pty ,id=@var{id}
1788 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
1789 not take any options.
1791 @option{pty} is not available on Windows hosts.
1793 @item -chardev stdio ,id=@var{id} [,signal=on|off]
1794 Connect to standard input and standard output of the qemu process.
1796 @option{signal} controls if signals are enabled on the terminal, that includes
1797 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
1798 default, use @option{signal=off} to disable it.
1800 @option{stdio} is not available on Windows hosts.
1802 @item -chardev braille ,id=@var{id}
1804 Connect to a local BrlAPI server. @option{braille} does not take any options.
1806 @item -chardev tty ,id=@var{id} ,path=@var{path}
1808 Connect to a local tty device.
1810 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
1813 @option{path} specifies the path to the tty. @option{path} is required.
1815 @item -chardev parport ,id=@var{id} ,path=@var{path}
1817 @option{parport} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
1819 Connect to a local parallel port.
1821 @option{path} specifies the path to the parallel port device. @option{path} is
1824 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
1826 @option{spicevmc} is only available when spice support is built in.
1828 @option{debug} debug level for spicevmc
1830 @option{name} name of spice channel to connect to
1832 Connect to a spice virtual machine channel, such as vdiport.
1840 DEFHEADING(Device URL Syntax:)
1842 In addition to using normal file images for the emulated storage devices,
1843 QEMU can also use networked resources such as iSCSI devices. These are
1844 specified using a special URL syntax.
1848 iSCSI support allows QEMU to access iSCSI resources directly and use as
1849 images for the guest storage. Both disk and cdrom images are supported.
1851 Syntax for specifying iSCSI LUNs is
1852 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
1854 Example (without authentication):
1856 qemu -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
1857 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
1858 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
1861 Example (CHAP username/password via URL):
1863 qemu -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
1866 Example (CHAP username/password via environment variables):
1868 LIBISCSI_CHAP_USERNAME="user" \
1869 LIBISCSI_CHAP_PASSWORD="password" \
1870 qemu -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
1873 iSCSI support is an optional feature of QEMU and only available when
1874 compiled and linked against libiscsi.
1876 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1877 "-iscsi [user=user][,password=password]\n"
1878 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1879 " [,initiator-name=iqn]\n"
1880 " iSCSI session parameters\n", QEMU_ARCH_ALL)
1884 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
1885 as Unix Domain Sockets.
1887 Syntax for specifying a NBD device using TCP
1888 ``nbd:<server-ip>:<port>[:exportname=<export>]''
1890 Syntax for specifying a NBD device using Unix Domain Sockets
1891 ``nbd:unix:<domain-socket>[:exportname=<export>]''
1896 qemu --drive file=nbd:192.0.2.1:30000
1899 Example for Unix Domain Sockets
1901 qemu --drive file=nbd:unix:/tmp/nbd-socket
1905 Sheepdog is a distributed storage system for QEMU.
1906 QEMU supports using either local sheepdog devices or remote networked
1909 Syntax for specifying a sheepdog device
1911 ``sheepdog:<vdiname>''
1913 ``sheepdog:<vdiname>:<snapid>''
1915 ``sheepdog:<vdiname>:<tag>''
1917 ``sheepdog:<host>:<port>:<vdiname>''
1919 ``sheepdog:<host>:<port>:<vdiname>:<snapid>''
1921 ``sheepdog:<host>:<port>:<vdiname>:<tag>''
1926 qemu --drive file=sheepdog:192.0.2.1:30000:MyVirtualMachine
1929 See also @url{http://http://www.osrg.net/sheepdog/}.
1934 DEFHEADING(Bluetooth(R) options:)
1936 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
1937 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands
\n" \
1938 "-bt hci
,host
[:id
]\n" \
1939 " use host
's HCI with the given name\n" \
1940 "-bt hci[,vlan=n]\n" \
1941 " emulate a standard HCI in virtual scatternet 'n
'\n" \
1942 "-bt vhci[,vlan=n]\n" \
1943 " add host computer to virtual scatternet 'n
' using VHCI\n" \
1944 "-bt device:dev[,vlan=n]\n" \
1945 " emulate a bluetooth device 'dev
' in scatternet 'n
'\n",
1952 Defines the function of the corresponding Bluetooth HCI. -bt options
1953 are matched with the HCIs present in the chosen machine type. For
1954 example when emulating a machine with only one HCI built into it, only
1955 the first @code{-bt hci[...]} option is valid and defines the HCI's
1956 logic
. The Transport Layer is decided by the machine type
. Currently
1957 the machines @code
{n800
} and @code
{n810
} have one HCI and all other
1961 The following three types are recognized
:
1965 (default) The corresponding Bluetooth HCI assumes no internal logic
1966 and will not respond to any HCI commands or emit events
.
1968 @item
-bt hci
,host
[:@
var{id
}]
1969 (@code
{bluez
} only
) The corresponding HCI passes commands
/ events
1970 to
/ from the physical HCI identified by the name @
var{id
} (default:
1971 @code
{hci0
}) on the computer running QEMU
. Only available on @code
{bluez
}
1972 capable systems like Linux
.
1974 @item
-bt hci
[,vlan
=@
var{n
}]
1975 Add a virtual
, standard HCI that will participate
in the Bluetooth
1976 scatternet @
var{n
} (default @code
{0}). Similarly to @option
{-net
}
1977 VLANs
, devices inside a bluetooth network @
var{n
} can only communicate
1978 with other devices
in the same
network (scatternet
).
1981 @item
-bt vhci
[,vlan
=@
var{n
}]
1982 (Linux
-host only
) Create a HCI
in scatternet @
var{n
} (default 0) attached
1983 to the host bluetooth stack instead of to the emulated target
. This
1984 allows the host and target machines to participate
in a common scatternet
1985 and communicate
. Requires the Linux @code
{vhci
} driver installed
. Can
1986 be used as following
:
1989 qemu
[...OPTIONS
...] -bt hci
,vlan
=5 -bt vhci
,vlan
=5
1992 @item
-bt device
:@
var{dev
}[,vlan
=@
var{n
}]
1993 Emulate a bluetooth device @
var{dev
} and place it
in network @
var{n
}
1994 (default @code
{0}). QEMU can only emulate one type of bluetooth devices
1999 Virtual wireless keyboard implementing the HIDP bluetooth profile
.
2006 DEFHEADING(Linux
/Multiboot boot specific
:)
2009 When
using these options
, you can use a given Linux or Multiboot
2010 kernel without installing it
in the disk image
. It can be useful
2011 for easier testing of various kernels
.
2016 DEF("kernel", HAS_ARG
, QEMU_OPTION_kernel
, \
2017 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL
)
2019 @item
-kernel @
var{bzImage
}
2021 Use @
var{bzImage
} as kernel image
. The kernel can be either a Linux kernel
2022 or
in multiboot format
.
2025 DEF("append", HAS_ARG
, QEMU_OPTION_append
, \
2026 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL
)
2028 @item
-append @
var{cmdline
}
2030 Use @
var{cmdline
} as kernel command line
2033 DEF("initrd", HAS_ARG
, QEMU_OPTION_initrd
, \
2034 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL
)
2036 @item
-initrd @
var{file
}
2038 Use @
var{file
} as initial ram disk
.
2040 @item
-initrd
"@var{file1} arg=foo,@var{file2}"
2042 This syntax is only available with multiboot
.
2044 Use @
var{file1
} and @
var{file2
} as modules and pass arg
=foo as parameter to the
2048 DEF("dtb", HAS_ARG
, QEMU_OPTION_dtb
, \
2049 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL
)
2051 @item
-dtb @
var{file
}
2053 Use @
var{file
} as a device tree
binary (dtb
) image and pass it to the kernel
2063 DEFHEADING(Debug
/Expert options
:)
2069 DEF("serial", HAS_ARG
, QEMU_OPTION_serial
, \
2070 "-serial dev redirect the serial port to char device 'dev'\n",
2073 @item
-serial @
var{dev
}
2075 Redirect the virtual serial port to host character device
2076 @
var{dev
}. The
default device is @code
{vc
} in graphical mode and
2077 @code
{stdio
} in non graphical mode
.
2079 This option can be used several times to simulate up to
4 serial
2082 Use @code
{-serial none
} to disable all serial ports
.
2084 Available character devices are
:
2086 @item vc
[:@
var{W
}x@
var{H
}]
2087 Virtual console
. Optionally
, a width and height can be given
in pixel with
2091 It is also possible to specify width or height
in characters
:
2096 [Linux only
] Pseudo
TTY (a
new PTY is automatically allocated
)
2098 No device is allocated
.
2102 [Linux only
] Use host tty
, e
.g
. @file
{/dev
/ttyS0
}. The host serial port
2103 parameters are set according to the emulated ones
.
2104 @item
/dev
/parport@
var{N
}
2105 [Linux only
, parallel port only
] Use host parallel port
2106 @
var{N
}. Currently SPP and EPP parallel port features can be used
.
2107 @item file
:@
var{filename
}
2108 Write output to @
var{filename
}. No character can be read
.
2110 [Unix only
] standard input
/output
2111 @item pipe
:@
var{filename
}
2112 name pipe @
var{filename
}
2114 [Windows only
] Use host serial port @
var{n
}
2115 @item udp
:[@
var{remote_host
}]:@
var{remote_port
}[@@
[@
var{src_ip
}]:@
var{src_port
}]
2116 This
implements UDP Net Console
.
2117 When @
var{remote_host
} or @
var{src_ip
} are not specified
2118 they
default to @code
{0.0.0.0}.
2119 When not
using a specified @
var{src_port
} a random port is automatically chosen
.
2121 If you just want a simple readonly console you can use @code
{netcat
} or
2122 @code
{nc
}, by starting qemu with
: @code
{-serial udp
::4555} and nc as
:
2123 @code
{nc
-u
-l
-p
4555}. Any time qemu writes something to that port it
2124 will appear
in the netconsole session
.
2126 If you plan to send characters back via netconsole or you want to stop
2127 and start qemu a lot of times
, you should have qemu use the same
2128 source port each time by
using something like @code
{-serial
2129 udp
::4555@@
:4556} to qemu
. Another approach is to use a patched
2130 version of netcat which can listen to a TCP port and send and receive
2131 characters via udp
. If you have a patched version of netcat which
2132 activates telnet remote echo and single char transfer
, then you can
2133 use the following options to step up a netcat redirector to allow
2134 telnet on port
5555 to access the qemu port
.
2137 -serial udp
::4555@@
:4556
2138 @item netcat options
:
2139 -u
-P
4555 -L
0.0.0.0:4556 -t
-p
5555 -I
-T
2140 @item telnet options
:
2144 @item tcp
:[@
var{host
}]:@
var{port
}[,@
var{server
}][,nowait
][,nodelay
]
2145 The TCP Net Console has two modes of operation
. It can send the serial
2146 I
/O to a location or wait
for a connection from a location
. By
default
2147 the TCP Net Console is sent to @
var{host
} at the @
var{port
}. If you use
2148 the @
var{server
} option QEMU will wait
for a client socket application
2149 to connect to the port before continuing
, unless the @code
{nowait
}
2150 option was specified
. The @code
{nodelay
} option disables the Nagle buffering
2151 algorithm
. If @
var{host
} is omitted
, 0.0.0.0 is assumed
. Only
2152 one TCP connection at a time is accepted
. You can use @code
{telnet
} to
2153 connect to the corresponding character device
.
2155 @item Example to send tcp console to
192.168.0.2 port
4444
2156 -serial tcp
:192.168.0.2:4444
2157 @item Example to listen and wait on port
4444 for connection
2158 -serial tcp
::4444,server
2159 @item Example to not wait and listen on ip
192.168.0.100 port
4444
2160 -serial tcp
:192.168.0.100:4444,server
,nowait
2163 @item telnet
:@
var{host
}:@
var{port
}[,server
][,nowait
][,nodelay
]
2164 The telnet protocol is used instead of raw tcp sockets
. The options
2165 work the same as
if you had specified @code
{-serial tcp
}. The
2166 difference is that the port acts like a telnet server or client
using
2167 telnet option negotiation
. This will also allow you to send the
2168 MAGIC_SYSRQ sequence
if you use a telnet that supports sending the
break
2169 sequence
. Typically
in unix telnet you
do it with Control
-] and then
2170 type
"send break" followed by pressing the enter key
.
2172 @item unix
:@
var{path
}[,server
][,nowait
]
2173 A unix domain socket is used instead of a tcp socket
. The option works the
2174 same as
if you had specified @code
{-serial tcp
} except the unix domain socket
2175 @
var{path
} is used
for connections
.
2177 @item mon
:@
var{dev_string
}
2178 This is a special option to allow the monitor to be multiplexed onto
2179 another serial port
. The monitor is accessed with key sequence of
2180 @key
{Control
-a
} and then pressing @key
{c
}. See monitor access
2181 @ref
{pcsys_keys
} in the
-nographic section
for more keys
.
2182 @
var{dev_string
} should be any one of the serial devices specified
2183 above
. An example to multiplex the monitor onto a telnet server
2184 listening on port
4444 would be
:
2186 @item
-serial mon
:telnet
::4444,server
,nowait
2190 Braille device
. This will use BrlAPI to display the braille output on a real
2194 Three button serial mouse
. Configure the guest to use Microsoft protocol
.
2198 DEF("parallel", HAS_ARG
, QEMU_OPTION_parallel
, \
2199 "-parallel dev redirect the parallel port to char device 'dev'\n",
2202 @item
-parallel @
var{dev
}
2204 Redirect the virtual parallel port to host device @
var{dev
} (same
2205 devices as the serial port
). On Linux hosts
, @file
{/dev
/parportN
} can
2206 be used to use hardware devices connected on the corresponding host
2209 This option can be used several times to simulate up to
3 parallel
2212 Use @code
{-parallel none
} to disable all parallel ports
.
2215 DEF("monitor", HAS_ARG
, QEMU_OPTION_monitor
, \
2216 "-monitor dev redirect the monitor to char device 'dev'\n",
2219 @item
-monitor @
var{dev
}
2221 Redirect the monitor to host device @
var{dev
} (same devices as the
2223 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2226 DEF("qmp", HAS_ARG
, QEMU_OPTION_qmp
, \
2227 "-qmp dev like -monitor but opens in 'control' mode\n",
2230 @item
-qmp @
var{dev
}
2232 Like
-monitor but opens
in 'control' mode
.
2235 DEF("mon", HAS_ARG
, QEMU_OPTION_mon
, \
2236 "-mon chardev=[name][,mode=readline|control][,default]\n", QEMU_ARCH_ALL
)
2238 @item
-mon chardev
=[name
][,mode
=readline|control
][,default]
2240 Setup monitor on chardev @
var{name
}.
2243 DEF("debugcon", HAS_ARG
, QEMU_OPTION_debugcon
, \
2244 "-debugcon dev redirect the debug console to char device 'dev'\n",
2247 @item
-debugcon @
var{dev
}
2249 Redirect the debug console to host device @
var{dev
} (same devices as the
2250 serial port
). The debug console is an I
/O port which is typically port
2251 0xe9; writing to that I
/O port sends output to
this device
.
2252 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2256 DEF("pidfile", HAS_ARG
, QEMU_OPTION_pidfile
, \
2257 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL
)
2259 @item
-pidfile @
var{file
}
2261 Store the QEMU process PID
in @
var{file
}. It is useful
if you launch QEMU
2265 DEF("singlestep", 0, QEMU_OPTION_singlestep
, \
2266 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL
)
2270 Run the emulation
in single step mode
.
2273 DEF("S", 0, QEMU_OPTION_S
, \
2274 "-S freeze CPU at startup (use 'c' to start execution)\n",
2279 Do not start CPU at
startup (you must type
'c' in the monitor
).
2282 DEF("gdb", HAS_ARG
, QEMU_OPTION_gdb
, \
2283 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL
)
2285 @item
-gdb @
var{dev
}
2287 Wait
for gdb connection on device @
var{dev
} (@pxref
{gdb_usage
}). Typical
2288 connections will likely be TCP
-based
, but also UDP
, pseudo TTY
, or even
2289 stdio are reasonable use
case. The latter is allowing to start qemu from
2290 within gdb and establish the connection via a pipe
:
2292 (gdb
) target remote | exec qemu
-gdb stdio
...
2296 DEF("s", 0, QEMU_OPTION_s
, \
2297 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT
"\n",
2302 Shorthand
for -gdb tcp
::1234, i
.e
. open a gdbserver on TCP port
1234
2303 (@pxref
{gdb_usage
}).
2306 DEF("d", HAS_ARG
, QEMU_OPTION_d
, \
2307 "-d item1,... output log to /tmp/qemu.log (use -d ? for a list of log items)\n",
2312 Output log
in /tmp
/qemu
.log
2315 DEF("D", HAS_ARG
, QEMU_OPTION_D
, \
2316 "-D logfile output log to logfile (instead of the default /tmp/qemu.log)\n",
2321 Output log
in logfile instead of
/tmp
/qemu
.log
2324 DEF("hdachs", HAS_ARG
, QEMU_OPTION_hdachs
, \
2325 "-hdachs c,h,s[,t]\n" \
2326 " force hard disk 0 physical geometry and the optional BIOS\n" \
2327 " translation (t=none or lba) (usually qemu can guess them)\n",
2330 @item
-hdachs @
var{c
},@
var{h
},@
var{s
},[,@
var{t
}]
2332 Force hard disk
0 physical
geometry (1 <= @
var{c
} <= 16383, 1 <=
2333 @
var{h
} <= 16, 1 <= @
var{s
} <= 63) and optionally force the BIOS
2334 translation
mode (@
var{t
}=none
, lba or auto
). Usually QEMU can guess
2335 all those parameters
. This option is useful
for old MS
-DOS disk
2339 DEF("L", HAS_ARG
, QEMU_OPTION_L
, \
2340 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2345 Set the directory
for the BIOS
, VGA BIOS and keymaps
.
2348 DEF("bios", HAS_ARG
, QEMU_OPTION_bios
, \
2349 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL
)
2351 @item
-bios @
var{file
}
2353 Set the filename
for the BIOS
.
2356 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm
, \
2357 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL
)
2361 Enable KVM full virtualization support
. This option is only available
2362 if KVM support is enabled when compiling
.
2365 DEF("xen-domid", HAS_ARG
, QEMU_OPTION_xen_domid
,
2366 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL
)
2367 DEF("xen-create", 0, QEMU_OPTION_xen_create
,
2368 "-xen-create create domain using xen hypercalls, bypassing xend\n"
2369 " warning: should not be used when xend is in use\n",
2371 DEF("xen-attach", 0, QEMU_OPTION_xen_attach
,
2372 "-xen-attach attach to existing xen domain\n"
2373 " xend will use this when starting qemu\n",
2376 @item
-xen
-domid @
var{id
}
2378 Specify xen guest domain @
var{id
} (XEN only
).
2381 Create domain
using xen hypercalls
, bypassing xend
.
2382 Warning
: should not be used when xend is
in use (XEN only
).
2385 Attach to existing xen domain
.
2386 xend will use
this when starting
qemu (XEN only
).
2389 DEF("no-reboot", 0, QEMU_OPTION_no_reboot
, \
2390 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL
)
2394 Exit instead of rebooting
.
2397 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown
, \
2398 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL
)
2401 @findex
-no
-shutdown
2402 Don
't exit QEMU on guest shutdown, but instead only stop the emulation.
2403 This allows for instance switching to monitor to commit changes to the
2407 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
2408 "-loadvm [tag|id]\n" \
2409 " start right away with a saved state (loadvm in monitor)\n",
2412 @item -loadvm @var{file}
2414 Start right away with a saved state (@code{loadvm} in monitor)
2418 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
2419 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
2424 Daemonize the QEMU process after initialization. QEMU will not detach from
2425 standard IO until it is ready to receive connections on any of its devices.
2426 This option is a useful way for external programs to launch QEMU without having
2427 to cope with initialization race conditions.
2430 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
2431 "-option-rom rom load a file, rom, into the option ROM space\n",
2434 @item -option-rom @var{file}
2436 Load the contents of @var{file} as an option ROM.
2437 This option is useful to load things like EtherBoot.
2440 DEF("clock", HAS_ARG, QEMU_OPTION_clock, \
2441 "-clock force the use of the given methods for timer alarm.\n" \
2442 " To see what timers are available use -clock ?\n",
2445 @item -clock @var{method}
2447 Force the use of the given methods for timer alarm. To see what timers
2448 are available use -clock ?.
2451 HXCOMM Options deprecated by -rtc
2452 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
2453 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
2455 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
2456 "-rtc [base=utc|localtime|date][,clock=host|vm][,driftfix=none|slew]\n" \
2457 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
2462 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
2464 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
2465 UTC or local time, respectively. @code{localtime} is required for correct date in
2466 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
2467 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
2469 By default the RTC is driven by the host system time. This allows to use the
2470 RTC as accurate reference clock inside the guest, specifically if the host
2471 time is smoothly following an accurate external reference clock, e.g. via NTP.
2472 If you want to isolate the guest time from the host, even prevent it from
2473 progressing during suspension, you can set @option{clock} to @code{vm} instead.
2475 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
2476 specifically with Windows' ACPI HAL
. This option will
try to figure out how
2477 many timer interrupts were not processed by the Windows guest and will
2481 DEF("icount", HAS_ARG
, QEMU_OPTION_icount
, \
2482 "-icount [N|auto]\n" \
2483 " enable virtual instruction counter with 2^N clock ticks per\n" \
2484 " instruction\n", QEMU_ARCH_ALL
)
2486 @item
-icount
[@
var{N
}|auto
]
2488 Enable virtual instruction counter
. The virtual cpu will execute one
2489 instruction every
2^@
var{N
} ns of virtual time
. If @code
{auto
} is specified
2490 then the virtual cpu speed will be automatically adjusted to keep virtual
2491 time within a few seconds of real time
.
2493 Note that
while this option can give deterministic behavior
, it does not
2494 provide cycle accurate emulation
. Modern CPUs contain superscalar out of
2495 order cores with complex cache hierarchies
. The number of instructions
2496 executed often has little or no correlation with actual performance
.
2499 DEF("watchdog", HAS_ARG
, QEMU_OPTION_watchdog
, \
2500 "-watchdog i6300esb|ib700\n" \
2501 " enable virtual hardware watchdog [default=none]\n",
2504 @item
-watchdog @
var{model
}
2506 Create a virtual hardware watchdog device
. Once
enabled (by a guest
2507 action
), the watchdog must be periodically polled by an agent inside
2508 the guest or
else the guest will be restarted
.
2510 The @
var{model
} is the model of hardware watchdog to emulate
. Choices
2511 for model are
: @code
{ib700
} (iBASE
700) which is a very simple ISA
2512 watchdog with a single timer
, or @code
{i6300esb
} (Intel
6300ESB I
/O
2513 controller hub
) which is a much more featureful PCI
-based dual
-timer
2514 watchdog
. Choose a model
for which your guest has drivers
.
2516 Use @code
{-watchdog ?
} to list available hardware models
. Only one
2517 watchdog can be enabled
for a guest
.
2520 DEF("watchdog-action", HAS_ARG
, QEMU_OPTION_watchdog_action
, \
2521 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
2522 " action when watchdog fires [default=reset]\n",
2525 @item
-watchdog
-action @
var{action
}
2527 The @
var{action
} controls what QEMU will
do when the watchdog timer
2530 @code
{reset
} (forcefully reset the guest
).
2531 Other possible actions are
:
2532 @code
{shutdown
} (attempt to gracefully shutdown the guest
),
2533 @code
{poweroff
} (forcefully poweroff the guest
),
2534 @code
{pause
} (pause the guest
),
2535 @code
{debug
} (print a debug message and
continue), or
2536 @code
{none
} (do nothing
).
2538 Note that the @code
{shutdown
} action requires that the guest responds
2539 to ACPI signals
, which it may not be able to
do in the sort of
2540 situations where the watchdog would have expired
, and thus
2541 @code
{-watchdog
-action shutdown
} is not recommended
for production use
.
2546 @item
-watchdog i6300esb
-watchdog
-action pause
2547 @item
-watchdog ib700
2551 DEF("echr", HAS_ARG
, QEMU_OPTION_echr
, \
2552 "-echr chr set terminal escape character instead of ctrl-a\n",
2556 @item
-echr @
var{numeric_ascii_value
}
2558 Change the escape character used
for switching to the monitor when
using
2559 monitor and serial sharing
. The
default is @code
{0x01} when
using the
2560 @code
{-nographic
} option
. @code
{0x01} is equal to pressing
2561 @code
{Control
-a
}. You can select a different character from the ascii
2562 control keys where
1 through
26 map to Control
-a through Control
-z
. For
2563 instance you could use the either of the following to change the escape
2564 character to Control
-t
.
2571 DEF("virtioconsole", HAS_ARG
, QEMU_OPTION_virtiocon
, \
2572 "-virtioconsole c\n" \
2573 " set virtio console\n", QEMU_ARCH_ALL
)
2575 @item
-virtioconsole @
var{c
}
2576 @findex
-virtioconsole
2579 This option is maintained
for backward compatibility
.
2581 Please use @code
{-device virtconsole
} for the
new way of invocation
.
2584 DEF("show-cursor", 0, QEMU_OPTION_show_cursor
, \
2585 "-show-cursor show cursor\n", QEMU_ARCH_ALL
)
2588 @findex
-show
-cursor
2592 DEF("tb-size", HAS_ARG
, QEMU_OPTION_tb_size
, \
2593 "-tb-size n set TB size\n", QEMU_ARCH_ALL
)
2595 @item
-tb
-size @
var{n
}
2600 DEF("incoming", HAS_ARG
, QEMU_OPTION_incoming
, \
2601 "-incoming p prepare for incoming migration, listen on port p\n",
2604 @item
-incoming @
var{port
}
2606 Prepare
for incoming migration
, listen on @
var{port
}.
2609 DEF("nodefaults", 0, QEMU_OPTION_nodefaults
, \
2610 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL
)
2614 Don
't create default devices.
2618 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
2619 "-chroot dir chroot to dir just before starting the VM\n",
2623 @item -chroot @var{dir}
2625 Immediately before starting guest execution, chroot to the specified
2626 directory. Especially useful in combination with -runas.
2630 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
2631 "-runas user change to user id user just before starting the VM\n",
2635 @item -runas @var{user}
2637 Immediately before starting guest execution, drop root privileges, switching
2638 to the specified user.
2641 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
2642 "-prom-env variable=value\n"
2643 " set OpenBIOS nvram variables\n",
2644 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
2646 @item -prom-env @var{variable}=@var{value}
2648 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
2650 DEF("semihosting", 0, QEMU_OPTION_semihosting,
2651 "-semihosting semihosting mode\n", QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA)
2654 @findex -semihosting
2655 Semihosting mode (ARM, M68K, Xtensa only).
2657 DEF("old-param", 0, QEMU_OPTION_old_param,
2658 "-old-param old param mode\n", QEMU_ARCH_ARM)
2661 @findex -old-param (ARM)
2662 Old param mode (ARM only).
2665 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
2666 "-readconfig <file>\n", QEMU_ARCH_ALL)
2668 @item -readconfig @var{file}
2670 Read device configuration from @var{file}.
2672 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
2673 "-writeconfig <file>\n"
2674 " read/write config file\n", QEMU_ARCH_ALL)
2676 @item -writeconfig @var{file}
2677 @findex -writeconfig
2678 Write device configuration to @var{file}.
2680 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
2682 " do not load default config files at startup\n",
2686 @findex -nodefconfig
2687 Normally QEMU loads a configuration file from @var{sysconfdir}/qemu.conf and
2688 @var{sysconfdir}/target-@var{ARCH}.conf on startup. The @code{-nodefconfig}
2689 option will prevent QEMU from loading these configuration files at startup.
2691 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
2692 "-trace [events=<file>][,file=<file>]\n"
2693 " specify tracing options\n",
2696 HXCOMM This line is not accurate, as some sub-options are backend-specific but
2697 HXCOMM HX does not support conditional compilation of text.
2698 @item -trace [events=@var{file}][,file=@var{file}]
2701 Specify tracing options.
2704 @item events=@var{file}
2705 Immediately enable events listed in @var{file}.
2706 The file must contain one event name (as listed in the @var{trace-events} file)
2708 This option is only available if QEMU has been compiled with
2709 either @var{simple} or @var{stderr} tracing backend.
2710 @item file=@var{file}
2711 Log output traces to @var{file}.
2713 This option is only available if QEMU has been compiled with
2714 the @var{simple} tracing backend.
2718 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest,
2719 "-qtest CHR specify tracing options\n",
2722 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log,
2723 "-qtest-log LOG specify tracing options\n",
2726 HXCOMM This is the last statement. Insert new options before this line!