1 HXCOMM Use
DEFHEADING() to define headings
in both help text and texi
2 HXCOMM Text between STEXI and ETEXI are copied to texi version and
3 HXCOMM discarded from C version
4 HXCOMM
DEF(option
, HAS_ARG
/0, opt_enum
, opt_help
, arch_mask
) is used to
5 HXCOMM construct option structures
, enums and help message
for specified
7 HXCOMM HXCOMM can be used
for comments
, discarded from both texi and C
9 DEFHEADING(Standard options
:)
14 DEF("help", 0, QEMU_OPTION_h
,
15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL
)
22 DEF("version", 0, QEMU_OPTION_version
,
23 "-version display version information and exit\n", QEMU_ARCH_ALL
)
27 Display version information and exit
30 DEF("machine", HAS_ARG
, QEMU_OPTION_machine
, \
31 "-machine [type=]name[,prop[=value][,...]]\n"
32 " selects emulated machine ('-machine help' for list)\n"
33 " property accel=accel1[:accel2[:...]] selects accelerator\n"
34 " supported accelerators are kvm, xen, tcg (default: tcg)\n"
35 " kernel_irqchip=on|off controls accelerated irqchip support\n"
36 " kvm_shadow_mem=size of KVM shadow MMU\n"
37 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
38 " mem-merge=on|off controls memory merge support (default: on)\n",
41 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
43 Select the emulated machine by @
var{name
}. Use @code
{-machine help
} to list
44 available machines
. Supported machine properties are
:
46 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
47 This is used to enable an accelerator
. Depending on the target architecture
,
48 kvm
, xen
, or tcg can be available
. By
default, tcg is used
. If there is more
49 than one accelerator specified
, the next one is used
if the previous one fails
51 @item kernel_irqchip
=on|off
52 Enables
in-kernel irqchip support
for the chosen accelerator when available
.
53 @item kvm_shadow_mem
=size
54 Defines the size of the KVM shadow MMU
.
55 @item dump
-guest
-core
=on|off
56 Include guest memory
in a core dump
. The
default is on
.
57 @item mem
-merge
=on|off
58 Enables or disables memory merge support
. This feature
, when supported by
59 the host
, de
-duplicates identical memory pages among VMs instances
64 HXCOMM Deprecated by
-machine
65 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
67 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
68 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
70 @item
-cpu @
var{model
}
72 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
75 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
76 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
77 " set the number of CPUs to 'n' [default=1]\n"
78 " maxcpus= maximum number of total cpus, including\n"
79 " offline CPUs for hotplug, etc\n"
80 " cores= number of CPU cores on one socket\n"
81 " threads= number of threads on one CPU core\n"
82 " sockets= number of discrete sockets in the system\n",
85 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
87 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
88 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
90 For the PC target
, the number of @
var{cores
} per socket
, the number
91 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
92 specified
. Missing values will be computed
. If any on the three values is
93 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
94 specifies the maximum number of hotpluggable CPUs
.
97 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
98 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n"
99 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL
)
101 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
102 @item
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
104 Simulate a multi node NUMA system
. If @samp
{mem
}, @samp
{memdev
}
105 and @samp
{cpus
} are omitted
, resources are split equally
. Also
, note
106 that the
-@option
{numa
} option doesn
't allocate any of the specified
107 resources. That is, it just assigns existing resources to NUMA nodes. This
108 means that one still has to use the @option{-m}, @option{-smp} options
109 to allocate RAM and VCPUs respectively, and possibly @option{-object}
110 to specify the memory backend for the @samp{memdev} suboption.
112 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
113 node uses @samp{memdev}, all of them have to use it.
116 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
117 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
118 " Add 'fd
' to fd 'set
'\n", QEMU_ARCH_ALL)
120 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
123 Add a file descriptor to an fd set. Valid options are:
127 This option defines the file descriptor of which a duplicate is added to fd set.
128 The file descriptor cannot be stdin, stdout, or stderr.
130 This option defines the ID of the fd set to add the file descriptor to.
131 @item opaque=@var{opaque}
132 This option defines a free-form string that can be used to describe @var{fd}.
135 You can open an image using pre-opened file descriptors from an fd set:
138 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
139 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
140 -drive file=/dev/fdset/2,index=0,media=disk
144 DEF("set", HAS_ARG, QEMU_OPTION_set,
145 "-set group.id.arg=value\n"
146 " set <arg> parameter for item <id> of type <group>\n"
147 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
149 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
151 Set parameter @var{arg} for item @var{id} of type @var{group}\n"
154 DEF("global", HAS_ARG, QEMU_OPTION_global,
155 "-global driver.prop=value\n"
156 " set a global default for a driver property\n",
159 @item -global @var{driver}.@var{prop}=@var{value}
161 Set default value of @var{driver}'s property @
var{prop
} to @
var{value
}, e
.g
.:
164 qemu
-system
-i386
-global ide
-drive
.physical_block_size
=4096 -drive file
=file
,if=ide
,index
=0,media
=disk
167 In particular
, you can use
this to set driver properties
for devices which are
168 created automatically by the machine model
. To create a device which is not
169 created automatically and set properties on it
, use
-@option
{device
}.
172 DEF("boot", HAS_ARG
, QEMU_OPTION_boot
,
173 "-boot [order=drives][,once=drives][,menu=on|off]\n"
174 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
175 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
176 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
177 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
178 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
181 @item
-boot
[order
=@
var{drives
}][,once
=@
var{drives
}][,menu
=on|off
][,splash
=@
var{sp_name
}][,splash
-time
=@
var{sp_time
}][,reboot
-timeout
=@
var{rb_timeout
}][,strict
=on|off
]
183 Specify boot order @
var{drives
} as a string of drive letters
. Valid
184 drive letters depend on the target achitecture
. The x86 PC uses
: a
, b
185 (floppy
1 and
2), c (first hard disk
), d (first CD
-ROM
), n
-p (Etherboot
186 from network adapter
1-4), hard disk boot is the
default. To apply a
187 particular boot order only on the first startup
, specify it via
190 Interactive boot menus
/prompts can be enabled via @option
{menu
=on
} as far
191 as firmware
/BIOS supports them
. The
default is non
-interactive boot
.
193 A splash picture could be passed to bios
, enabling user to show it as logo
,
194 when option splash
=@
var{sp_name
} is given and menu
=on
, If firmware
/BIOS
195 supports them
. Currently Seabios
for X86 system support it
.
196 limitation
: The splash file could be a jpeg file or a BMP file
in 24 BPP
197 format(true color
). The resolution should be supported by the SVGA mode
, so
198 the recommended is
320x240
, 640x480
, 800x640
.
200 A timeout could be passed to bios
, guest will pause
for @
var{rb_timeout
} ms
201 when boot failed
, then reboot
. If @
var{rb_timeout
} is
'-1', guest will not
202 reboot
, qemu passes
'-1' to bios by
default. Currently Seabios
for X86
205 Do strict boot via @option
{strict
=on
} as far as firmware
/BIOS
206 supports it
. This only effects when boot priority is changed by
207 bootindex options
. The
default is non
-strict boot
.
210 #
try to boot from network first
, then from hard disk
211 qemu
-system
-i386
-boot order
=nc
212 # boot from CD
-ROM first
, switch back to
default order after reboot
213 qemu
-system
-i386
-boot once
=d
214 # boot with a splash picture
for 5 seconds
.
215 qemu
-system
-i386
-boot menu
=on
,splash
=/root
/boot
.bmp
,splash
-time
=5000
218 Note
: The legacy format
'-boot @var{drives}' is still supported but its
219 use is discouraged as it may be removed from future versions
.
222 DEF("m", HAS_ARG
, QEMU_OPTION_m
,
223 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
224 " configure guest RAM\n"
225 " size: initial amount of guest memory (default: "
226 stringify(DEFAULT_RAM_SIZE
) "MiB)\n"
227 " slots: number of hotplug slots (default: none)\n"
228 " maxmem: maximum amount of guest memory (default: none)\n"
229 "NOTE: Some architectures might enforce a specific granularity\n",
232 @item
-m
[size
=]@
var{megs
}
234 Set virtual RAM size to @
var{megs
} megabytes
. Default is
128 MiB
. Optionally
,
235 a suffix of ``M
'' or ``G
'' can be used to signify a value
in megabytes or
236 gigabytes respectively
. Optional pair @
var{slots
}, @
var{maxmem
} could be used
237 to set amount of hotluggable memory slots and possible maximum amount of memory
.
240 DEF("mem-path", HAS_ARG
, QEMU_OPTION_mempath
,
241 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL
)
243 @item
-mem
-path @
var{path
}
245 Allocate guest RAM from a temporarily created file
in @
var{path
}.
248 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc
,
249 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
253 @findex
-mem
-prealloc
254 Preallocate memory when
using -mem
-path
.
257 DEF("k", HAS_ARG
, QEMU_OPTION_k
,
258 "-k language use keyboard layout (for example 'fr' for French)\n",
261 @item
-k @
var{language
}
263 Use keyboard layout @
var{language
} (for example @code
{fr
} for
264 French
). This option is only needed where it is not easy to get raw PC
265 keycodes (e
.g
. on Macs
, with some X11 servers or with a VNC
266 display
). You don
't normally need to use it on PC/Linux or PC/Windows
269 The available layouts are:
271 ar de-ch es fo fr-ca hu ja mk no pt-br sv
272 da en-gb et fr fr-ch is lt nl pl ru th
273 de en-us fi fr-be hr it lv nl-be pt sl tr
276 The default is @code{en-us}.
280 DEF("audio-help", 0, QEMU_OPTION_audio_help,
281 "-audio-help print list of audio drivers and their options\n",
286 Will show the audio subsystem help: list of drivers, tunable
290 DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
291 "-soundhw c1,... enable audio support\n"
292 " and only specified sound cards (comma separated list)\n"
293 " use '-soundhw help
' to get the list of supported cards\n"
294 " use '-soundhw all
' to enable all of them\n", QEMU_ARCH_ALL)
296 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
298 Enable audio and selected sound hardware. Use 'help
' to print all
299 available sound hardware.
302 qemu-system-i386 -soundhw sb16,adlib disk.img
303 qemu-system-i386 -soundhw es1370 disk.img
304 qemu-system-i386 -soundhw ac97 disk.img
305 qemu-system-i386 -soundhw hda disk.img
306 qemu-system-i386 -soundhw all disk.img
307 qemu-system-i386 -soundhw help
310 Note that Linux's i810_audio OSS
kernel (for AC97
) module might
311 require manually specifying clocking
.
314 modprobe i810_audio clocking
=48000
318 DEF("balloon", HAS_ARG
, QEMU_OPTION_balloon
,
319 "-balloon none disable balloon device\n"
320 "-balloon virtio[,addr=str]\n"
321 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL
)
325 Disable balloon device
.
326 @item
-balloon virtio
[,addr
=@
var{addr
}]
327 Enable virtio balloon
device (default), optionally with PCI address
331 DEF("device", HAS_ARG
, QEMU_OPTION_device
,
332 "-device driver[,prop[=value][,...]]\n"
333 " add device (based on driver)\n"
334 " prop=value,... sets driver properties\n"
335 " use '-device help' to print all possible drivers\n"
336 " use '-device driver,help' to print all possible properties\n",
339 @item
-device @
var{driver
}[,@
var{prop
}[=@
var{value
}][,...]]
341 Add device @
var{driver
}. @
var{prop
}=@
var{value
} sets driver
342 properties
. Valid properties depend on the driver
. To get help on
343 possible drivers and properties
, use @code
{-device help
} and
344 @code
{-device @
var{driver
},help
}.
347 DEF("name", HAS_ARG
, QEMU_OPTION_name
,
348 "-name string1[,process=string2][,debug-threads=on|off]\n"
349 " set the name of the guest\n"
350 " string1 sets the window title and string2 the process name (on Linux)\n"
351 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
352 " NOTE: The thread names are for debugging and not a stable API.\n",
355 @item
-name @
var{name
}
357 Sets the @
var{name
} of the guest
.
358 This name will be displayed
in the SDL window caption
.
359 The @
var{name
} will also be used
for the VNC server
.
360 Also optionally set the top visible process name
in Linux
.
361 Naming of individual threads can also be enabled on Linux to aid debugging
.
364 DEF("uuid", HAS_ARG
, QEMU_OPTION_uuid
,
365 "-uuid %08x-%04x-%04x-%04x-%012x\n"
366 " specify machine UUID\n", QEMU_ARCH_ALL
)
368 @item
-uuid @
var{uuid
}
378 DEFHEADING(Block device options
:)
383 DEF("fda", HAS_ARG
, QEMU_OPTION_fda
,
384 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL
)
385 DEF("fdb", HAS_ARG
, QEMU_OPTION_fdb
, "", QEMU_ARCH_ALL
)
387 @item
-fda @
var{file
}
388 @item
-fdb @
var{file
}
391 Use @
var{file
} as floppy disk
0/1 image (@pxref
{disk_images
}). You can
392 use the host floppy by
using @file
{/dev
/fd0
} as
filename (@pxref
{host_drives
}).
395 DEF("hda", HAS_ARG
, QEMU_OPTION_hda
,
396 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL
)
397 DEF("hdb", HAS_ARG
, QEMU_OPTION_hdb
, "", QEMU_ARCH_ALL
)
398 DEF("hdc", HAS_ARG
, QEMU_OPTION_hdc
,
399 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL
)
400 DEF("hdd", HAS_ARG
, QEMU_OPTION_hdd
, "", QEMU_ARCH_ALL
)
402 @item
-hda @
var{file
}
403 @item
-hdb @
var{file
}
404 @item
-hdc @
var{file
}
405 @item
-hdd @
var{file
}
410 Use @
var{file
} as hard disk
0, 1, 2 or
3 image (@pxref
{disk_images
}).
413 DEF("cdrom", HAS_ARG
, QEMU_OPTION_cdrom
,
414 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
417 @item
-cdrom @
var{file
}
419 Use @
var{file
} as CD
-ROM
image (you cannot use @option
{-hdc
} and
420 @option
{-cdrom
} at the same time
). You can use the host CD
-ROM by
421 using @file
{/dev
/cdrom
} as
filename (@pxref
{host_drives
}).
424 DEF("drive", HAS_ARG
, QEMU_OPTION_drive
,
425 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
426 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
427 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
428 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
429 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
430 " [,readonly=on|off][,copy-on-read=on|off]\n"
431 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
432 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
433 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
434 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
435 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
436 " [[,iops_size=is]]\n"
437 " use 'file' as a drive image\n", QEMU_ARCH_ALL
)
439 @item
-drive @
var{option
}[,@
var{option
}[,@
var{option
}[,...]]]
442 Define a
new drive
. Valid options are
:
445 @item file
=@
var{file
}
446 This option defines which disk
image (@pxref
{disk_images
}) to use with
447 this drive
. If the filename contains comma
, you must double it
448 (for instance
, "file=my,,file" to use file
"my,file").
450 Special files such as iSCSI devices can be specified
using protocol
451 specific URLs
. See the section
for "Device URL Syntax" for more information
.
452 @item
if=@
var{interface}
453 This option defines on which type on
interface the drive is connected
.
454 Available types are
: ide
, scsi
, sd
, mtd
, floppy
, pflash
, virtio
.
455 @item bus
=@
var{bus
},unit
=@
var{unit
}
456 These options define where is connected the drive by defining the bus number and
458 @item index
=@
var{index
}
459 This option defines where is connected the drive by
using an index
in the list
460 of available connectors of a given
interface type
.
461 @item media
=@
var{media
}
462 This option defines the type of the media
: disk or cdrom
.
463 @item cyls
=@
var{c
},heads
=@
var{h
},secs
=@
var{s
}[,trans
=@
var{t
}]
464 These options have the same definition as they have
in @option
{-hdachs
}.
465 @item snapshot
=@
var{snapshot
}
466 @
var{snapshot
} is
"on" or
"off" and controls snapshot mode
for the given drive
467 (see @option
{-snapshot
}).
468 @item cache
=@
var{cache
}
469 @
var{cache
} is
"none", "writeback", "unsafe", "directsync" or
"writethrough" and controls how the host cache is used to access block data
.
471 @
var{aio
} is
"threads", or
"native" and selects between pthread based disk I
/O and native Linux AIO
.
472 @item discard
=@
var{discard
}
473 @
var{discard
} is one of
"ignore" (or
"off") or
"unmap" (or
"on") and controls whether @dfn
{discard
} (also known as @dfn
{trim
} or @dfn
{unmap
}) requests are ignored or passed to the filesystem
. Some machine types may not support discard requests
.
474 @item format
=@
var{format
}
475 Specify which disk @
var{format
} will be used rather than detecting
476 the format
. Can be used to specifiy format
=raw to avoid interpreting
477 an untrusted format header
.
478 @item serial
=@
var{serial
}
479 This option specifies the serial number to assign to the device
.
480 @item addr
=@
var{addr
}
481 Specify the controller
's PCI address (if=virtio only).
482 @item werror=@var{action},rerror=@var{action}
483 Specify which @var{action} to take on write and read errors. Valid actions are:
484 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
485 "report" (report the error to the guest), "enospc" (pause QEMU only if the
486 host disk is full; report the error to the guest otherwise).
487 The default setting is @option{werror=enospc} and @option{rerror=report}.
489 Open drive @option{file} as read-only. Guest write attempts will fail.
490 @item copy-on-read=@var{copy-on-read}
491 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
492 file sectors into the image file.
493 @item detect-zeroes=@var{detect-zeroes}
494 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
495 conversion of plain zero writes by the OS to driver specific optimized
496 zero write commands. You may even choose "unmap" if @var{discard} is set
497 to "unmap" to allow a zero write to be converted to an UNMAP operation.
500 By default, the @option{cache=writeback} mode is used. It will report data
501 writes as completed as soon as the data is present in the host page cache.
502 This is safe as long as your guest OS makes sure to correctly flush disk caches
503 where needed. If your guest OS does not handle volatile disk write caches
504 correctly and your host crashes or loses power, then the guest may experience
507 For such guests, you should consider using @option{cache=writethrough}. This
508 means that the host page cache will be used to read and write data, but write
509 notification will be sent to the guest only after QEMU has made sure to flush
510 each write to the disk. Be aware that this has a major impact on performance.
512 The host page cache can be avoided entirely with @option{cache=none}. This will
513 attempt to do disk IO directly to the guest's memory
. QEMU may still perform
514 an internal copy of the data
. Note that
this is considered a writeback mode and
515 the guest OS must handle the disk write cache correctly
in order to avoid data
516 corruption on host crashes
.
518 The host page cache can be avoided
while only sending write notifications to
519 the guest when the data has been flushed to the disk
using
520 @option
{cache
=directsync
}.
522 In
case you don
't care about data integrity over host failures, use
523 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
524 data to the disk but can instead keep things in cache. If anything goes wrong,
525 like your host losing power, the disk storage getting disconnected accidentally,
526 etc. your image will most probably be rendered unusable. When using
527 the @option{-snapshot} option, unsafe caching is always used.
529 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
530 useful when the backing file is over a slow network. By default copy-on-read
533 Instead of @option{-cdrom} you can use:
535 qemu-system-i386 -drive file=file,index=2,media=cdrom
538 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
541 qemu-system-i386 -drive file=file,index=0,media=disk
542 qemu-system-i386 -drive file=file,index=1,media=disk
543 qemu-system-i386 -drive file=file,index=2,media=disk
544 qemu-system-i386 -drive file=file,index=3,media=disk
547 You can open an image using pre-opened file descriptors from an fd set:
550 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
551 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
552 -drive file=/dev/fdset/2,index=0,media=disk
555 You can connect a CDROM to the slave of ide0:
557 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
560 If you don't specify the
"file=" argument
, you define an empty drive
:
562 qemu
-system
-i386
-drive
if=ide
,index
=1,media
=cdrom
565 You can connect a SCSI disk with unit ID
6 on the bus #
0:
567 qemu
-system
-i386
-drive file
=file
,if=scsi
,bus
=0,unit
=6
570 Instead of @option
{-fda
}, @option
{-fdb
}, you can use
:
572 qemu
-system
-i386
-drive file
=file
,index
=0,if=floppy
573 qemu
-system
-i386
-drive file
=file
,index
=1,if=floppy
576 By
default, @
var{interface} is
"ide" and @
var{index
} is automatically
579 qemu
-system
-i386
-drive file
=a
-drive file
=b
"
583 qemu-system-i386 -hda a -hdb b
587 DEF("mtdblock
", HAS_ARG, QEMU_OPTION_mtdblock,
588 "-mtdblock file use
'file' as on
-board Flash memory image
\n",
591 @item -mtdblock @var{file}
593 Use @var{file} as on-board Flash memory image.
596 DEF("sd
", HAS_ARG, QEMU_OPTION_sd,
597 "-sd file use
'file' as SecureDigital card image
\n", QEMU_ARCH_ALL)
601 Use @var{file} as SecureDigital card image.
604 DEF("pflash
", HAS_ARG, QEMU_OPTION_pflash,
605 "-pflash file use
'file' as a parallel flash image
\n", QEMU_ARCH_ALL)
607 @item -pflash @var{file}
609 Use @var{file} as a parallel flash image.
612 DEF("snapshot
", 0, QEMU_OPTION_snapshot,
613 "-snapshot write to temporary files instead of disk image files
\n",
618 Write to temporary files instead of disk image files. In this case,
619 the raw disk image you use is not written back. You can however force
620 the write back by pressing @key{C-a s} (@pxref{disk_images}).
623 DEF("hdachs
", HAS_ARG, QEMU_OPTION_hdachs, \
624 "-hdachs c
,h
,s
[,t
]\n" \
625 " force hard disk
0 physical geometry and the optional BIOS
\n" \
626 " translation (t
=none or lba
) (usually QEMU can guess them
)\n",
629 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
631 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
632 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
633 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
634 all those parameters. This option is useful for old MS-DOS disk
638 DEF("fsdev
", HAS_ARG, QEMU_OPTION_fsdev,
639 "-fsdev fsdriver
,id
=id
[,path
=path
,][security_model
={mapped
-xattr|mapped
-file|passthrough|none
}]\n"
640 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
645 @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}]
647 Define a new file system device. Valid options are:
650 This option specifies the fs driver backend to use.
651 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
653 Specifies identifier for this device
654 @item path=@var{path}
655 Specifies the export path for the file system device. Files under
656 this path will be available to the 9p client on the guest.
657 @item security_model=@var{security_model}
658 Specifies the security model to be used for this export path.
659 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
660 In "passthrough
" security model, files are stored using the same
661 credentials as they are created on the guest. This requires QEMU
662 to run as root. In "mapped
-xattr
" security model, some of the file
663 attributes like uid, gid, mode bits and link target are stored as
664 file attributes. For "mapped
-file
" these attributes are stored in the
665 hidden .virtfs_metadata directory. Directories exported by this security model cannot
666 interact with other unix tools. "none
" security model is same as
667 passthrough except the sever won't report failures if it fails to
668 set file attributes like ownership. Security model is mandatory
669 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
670 security model as a parameter.
671 @item writeout=@var{writeout}
672 This is an optional argument. The only supported value is "immediate
".
673 This means that host page cache will be used to read and write data but
674 write notification will be sent to the guest only when the data has been
675 reported as written by the storage subsystem.
677 Enables exporting 9p share as a readonly mount for guests. By default
678 read-write access is given.
679 @item socket=@var{socket}
680 Enables proxy filesystem driver to use passed socket file for communicating
681 with virtfs-proxy-helper
682 @item sock_fd=@var{sock_fd}
683 Enables proxy filesystem driver to use passed socket descriptor for
684 communicating with virtfs-proxy-helper. Usually a helper like libvirt
685 will create socketpair and pass one of the fds as sock_fd
688 -fsdev option is used along with -device driver "virtio
-9p
-pci
".
689 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
690 Options for virtio-9p-pci driver are:
693 Specifies the id value specified along with -fsdev option
694 @item mount_tag=@var{mount_tag}
695 Specifies the tag name to be used by the guest to mount this export point
700 DEF("virtfs
", HAS_ARG, QEMU_OPTION_virtfs,
701 "-virtfs local
,path
=path
,mount_tag
=tag
,security_model
=[mapped
-xattr|mapped
-file|passthrough|none
]\n"
702 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
707 @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}]
710 The general form of a Virtual File system pass-through options are:
713 This option specifies the fs driver backend to use.
714 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
716 Specifies identifier for this device
717 @item path=@var{path}
718 Specifies the export path for the file system device. Files under
719 this path will be available to the 9p client on the guest.
720 @item security_model=@var{security_model}
721 Specifies the security model to be used for this export path.
722 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
723 In "passthrough
" security model, files are stored using the same
724 credentials as they are created on the guest. This requires QEMU
725 to run as root. In "mapped
-xattr
" security model, some of the file
726 attributes like uid, gid, mode bits and link target are stored as
727 file attributes. For "mapped
-file
" these attributes are stored in the
728 hidden .virtfs_metadata directory. Directories exported by this security model cannot
729 interact with other unix tools. "none
" security model is same as
730 passthrough except the sever won't report failures if it fails to
731 set file attributes like ownership. Security model is mandatory only
732 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
733 model as a parameter.
734 @item writeout=@var{writeout}
735 This is an optional argument. The only supported value is "immediate
".
736 This means that host page cache will be used to read and write data but
737 write notification will be sent to the guest only when the data has been
738 reported as written by the storage subsystem.
740 Enables exporting 9p share as a readonly mount for guests. By default
741 read-write access is given.
742 @item socket=@var{socket}
743 Enables proxy filesystem driver to use passed socket file for
744 communicating with virtfs-proxy-helper. Usually a helper like libvirt
745 will create socketpair and pass one of the fds as sock_fd
747 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
748 descriptor for interfacing with virtfs-proxy-helper
752 DEF("virtfs_synth
", 0, QEMU_OPTION_virtfs_synth,
753 "-virtfs_synth Create synthetic file system image
\n",
757 @findex -virtfs_synth
758 Create synthetic file system image
766 DEFHEADING(USB options:)
771 DEF("usb
", 0, QEMU_OPTION_usb,
772 "-usb enable the USB
driver (will be the
default soon
)\n",
777 Enable the USB driver (will be the default soon)
780 DEF("usbdevice
", HAS_ARG, QEMU_OPTION_usbdevice,
781 "-usbdevice name add the host or guest USB device
'name'\n",
785 @item -usbdevice @var{devname}
787 Add the USB device @var{devname}. @xref{usb_devices}.
792 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
795 Pointer device that uses absolute coordinates (like a touchscreen). This
796 means QEMU is able to report the mouse position without having to grab the
797 mouse. Also overrides the PS/2 mouse emulation when activated.
799 @item disk:[format=@var{format}]:@var{file}
800 Mass storage device based on file. The optional @var{format} argument
801 will be used rather than detecting the format. Can be used to specifiy
802 @code{format=raw} to avoid interpreting an untrusted format header.
804 @item host:@var{bus}.@var{addr}
805 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
807 @item host:@var{vendor_id}:@var{product_id}
808 Pass through the host device identified by @var{vendor_id}:@var{product_id}
811 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
812 Serial converter to host character device @var{dev}, see @code{-serial} for the
816 Braille device. This will use BrlAPI to display the braille output on a real
819 @item net:@var{options}
820 Network adapter that supports CDC ethernet and RNDIS protocols.
830 DEFHEADING(Display options:)
835 DEF("display
", HAS_ARG, QEMU_OPTION_display,
836 "-display sdl
[,frame
=on|off
][,alt_grab
=on|off
][,ctrl_grab
=on|off
]\n"
837 " [,window_close
=on|off
]|curses|none|
\n"
838 " gtk
[,grab_on_hover
=on|off
]|
\n"
839 " vnc
=<display
>[,<optargs
>]\n"
840 " select display type
\n", QEMU_ARCH_ALL)
842 @item -display @var{type}
844 Select type of display to use. This option is a replacement for the
845 old style -sdl/-curses/... options. Valid values for @var{type} are
848 Display video output via SDL (usually in a separate graphics
849 window; see the SDL documentation for other possibilities).
851 Display video output via curses. For graphics device models which
852 support a text mode, QEMU can display this output using a
853 curses/ncurses interface. Nothing is displayed when the graphics
854 device is in graphical mode or if the graphics device does not support
855 a text mode. Generally only the VGA device models support text mode.
857 Do not display video output. The guest will still see an emulated
858 graphics card, but its output will not be displayed to the QEMU
859 user. This option differs from the -nographic option in that it
860 only affects what is done with video output; -nographic also changes
861 the destination of the serial and parallel port data.
863 Display video output in a GTK window. This interface provides drop-down
864 menus and other UI elements to configure and control the VM during
867 Start a VNC server on display <arg>
871 DEF("nographic
", 0, QEMU_OPTION_nographic,
872 "-nographic disable graphical output and redirect serial I
/Os to console
\n",
877 Normally, QEMU uses SDL to display the VGA output. With this option,
878 you can totally disable graphical output so that QEMU is a simple
879 command line application. The emulated serial port is redirected on
880 the console and muxed with the monitor (unless redirected elsewhere
881 explicitly). Therefore, you can still use QEMU to debug a Linux kernel
882 with a serial console. Use @key{C-a h} for help on switching between
883 the console and monitor.
886 DEF("curses
", 0, QEMU_OPTION_curses,
887 "-curses use a curses
/ncurses
interface instead of SDL
\n",
892 Normally, QEMU uses SDL to display the VGA output. With this option,
893 QEMU can display the VGA output when in text mode using a
894 curses/ncurses interface. Nothing is displayed in graphical mode.
897 DEF("no
-frame
", 0, QEMU_OPTION_no_frame,
898 "-no
-frame open SDL window without a frame and window decorations
\n",
903 Do not use decorations for SDL windows and start them using the whole
904 available screen space. This makes the using QEMU in a dedicated desktop
905 workspace more convenient.
908 DEF("alt
-grab
", 0, QEMU_OPTION_alt_grab,
909 "-alt
-grab use Ctrl
-Alt
-Shift to grab
mouse (instead of Ctrl
-Alt
)\n",
914 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
915 affects the special keys (for fullscreen, monitor-mode switching, etc).
918 DEF("ctrl
-grab
", 0, QEMU_OPTION_ctrl_grab,
919 "-ctrl
-grab use Right
-Ctrl to grab
mouse (instead of Ctrl
-Alt
)\n",
924 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
925 affects the special keys (for fullscreen, monitor-mode switching, etc).
928 DEF("no
-quit
", 0, QEMU_OPTION_no_quit,
929 "-no
-quit disable SDL window close capability
\n", QEMU_ARCH_ALL)
933 Disable SDL window close capability.
936 DEF("sdl
", 0, QEMU_OPTION_sdl,
937 "-sdl enable SDL
\n", QEMU_ARCH_ALL)
944 DEF("spice
", HAS_ARG, QEMU_OPTION_spice,
945 "-spice
[port
=port
][,tls
-port
=secured
-port
][,x509
-dir
=<dir
>]\n"
946 " [,x509
-key
-file
=<file
>][,x509
-key
-password
=<file
>]\n"
947 " [,x509
-cert
-file
=<file
>][,x509
-cacert
-file
=<file
>]\n"
948 " [,x509
-dh
-key
-file
=<file
>][,addr
=addr
][,ipv4|ipv6
]\n"
949 " [,tls
-ciphers
=<list
>]\n"
950 " [,tls
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
951 " [,plaintext
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
952 " [,sasl
][,password
=<secret
>][,disable
-ticketing
]\n"
953 " [,image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]]\n"
954 " [,jpeg
-wan
-compression
=[auto|
never|always
]]\n"
955 " [,zlib
-glz
-wan
-compression
=[auto|
never|always
]]\n"
956 " [,streaming
-video
=[off|all|filter
]][,disable
-copy
-paste
]\n"
957 " [,disable
-agent
-file
-xfer
][,agent
-mouse
=[on|off
]]\n"
958 " [,playback
-compression
=[on|off
]][,seamless
-migration
=[on|off
]]\n"
960 " at least one of
{port
, tls
-port
} is mandatory
\n",
963 @item -spice @var{option}[,@var{option}[,...]]
965 Enable the spice remote desktop protocol. Valid options are
970 Set the TCP port spice is listening on for plaintext channels.
973 Set the IP address spice is listening on. Default is any address.
977 Force using the specified IP version.
979 @item password=<secret>
980 Set the password you need to authenticate.
983 Require that the client use SASL to authenticate with the spice.
984 The exact choice of authentication method used is controlled from the
985 system / user's SASL configuration file for the 'qemu' service. This
986 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
987 unprivileged user, an environment variable SASL_CONF_PATH can be used
988 to make it search alternate locations for the service config.
989 While some SASL auth methods can also provide data encryption (eg GSSAPI),
990 it is recommended that SASL always be combined with the 'tls' and
991 'x509' settings to enable use of SSL and server certificates. This
992 ensures a data encryption preventing compromise of authentication
995 @item disable-ticketing
996 Allow client connects without authentication.
998 @item disable-copy-paste
999 Disable copy paste between the client and the guest.
1001 @item disable-agent-file-xfer
1002 Disable spice-vdagent based file-xfer between the client and the guest.
1005 Set the TCP port spice is listening on for encrypted channels.
1007 @item x509-dir=<dir>
1008 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1010 @item x509-key-file=<file>
1011 @item x509-key-password=<file>
1012 @item x509-cert-file=<file>
1013 @item x509-cacert-file=<file>
1014 @item x509-dh-key-file=<file>
1015 The x509 file names can also be configured individually.
1017 @item tls-ciphers=<list>
1018 Specify which ciphers to use.
1020 @item tls-channel=[main|display|cursor|inputs|record|playback]
1021 @item plaintext-channel=[main|display|cursor|inputs|record|playback]
1022 Force specific channel to be used with or without TLS encryption. The
1023 options can be specified multiple times to configure multiple
1024 channels. The special name "default" can be used to set the default
1025 mode. For channels which are not explicitly forced into one mode the
1026 spice client is allowed to pick tls/plaintext as he pleases.
1028 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1029 Configure image compression (lossless).
1030 Default is auto_glz.
1032 @item jpeg-wan-compression=[auto|never|always]
1033 @item zlib-glz-wan-compression=[auto|never|always]
1034 Configure wan image compression (lossy for slow links).
1037 @item streaming-video=[off|all|filter]
1038 Configure video stream detection. Default is filter.
1040 @item agent-mouse=[on|off]
1041 Enable/disable passing mouse events via vdagent. Default is on.
1043 @item playback-compression=[on|off]
1044 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1046 @item seamless-migration=[on|off]
1047 Enable/disable spice seamless migration. Default is off.
1052 DEF("portrait
", 0, QEMU_OPTION_portrait,
1053 "-portrait rotate graphical output
90 deg
left (only PXA LCD
)\n",
1058 Rotate graphical output 90 deg left (only PXA LCD).
1061 DEF("rotate
", HAS_ARG, QEMU_OPTION_rotate,
1062 "-rotate
<deg
> rotate graphical output some deg
left (only PXA LCD
)\n",
1065 @item -rotate @var{deg}
1067 Rotate graphical output some deg left (only PXA LCD).
1070 DEF("vga
", HAS_ARG, QEMU_OPTION_vga,
1071 "-vga
[std|cirrus|vmware|qxl|xenfb|tcx|cg3|none
]\n"
1072 " select video card type
\n", QEMU_ARCH_ALL)
1074 @item -vga @var{type}
1076 Select type of VGA card to emulate. Valid values for @var{type} are
1079 Cirrus Logic GD5446 Video card. All Windows versions starting from
1080 Windows 95 should recognize and use this graphic card. For optimal
1081 performances, use 16 bit color depth in the guest and the host OS.
1082 (This one is the default)
1084 Standard VGA card with Bochs VBE extensions. If your guest OS
1085 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1086 to use high resolution modes (>= 1280x1024x16) then you should use
1089 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1090 recent XFree86/XOrg server or Windows guest with a driver for this
1093 QXL paravirtual graphic card. It is VGA compatible (including VESA
1094 2.0 VBE support). Works best with qxl guest drivers installed though.
1095 Recommended choice when using the spice protocol.
1097 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1098 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1099 fixed resolution of 1024x768.
1101 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1102 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1103 resolutions aimed at people wishing to run older Solaris versions.
1109 DEF("full
-screen
", 0, QEMU_OPTION_full_screen,
1110 "-full
-screen start
in full screen
\n", QEMU_ARCH_ALL)
1113 @findex -full-screen
1114 Start in full screen.
1117 DEF("g
", 1, QEMU_OPTION_g ,
1118 "-g WxH
[xDEPTH
] Set the initial graphical resolution and depth
\n",
1119 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1121 @item -g @var{width}x@var{height}[x@var{depth}]
1123 Set the initial graphical resolution and depth (PPC, SPARC only).
1126 DEF("vnc
", HAS_ARG, QEMU_OPTION_vnc ,
1127 "-vnc display start a VNC server on display
\n", QEMU_ARCH_ALL)
1129 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1131 Normally, QEMU uses SDL to display the VGA output. With this option,
1132 you can have QEMU listen on VNC display @var{display} and redirect the VGA
1133 display over the VNC session. It is very useful to enable the usb
1134 tablet device when using this option (option @option{-usbdevice
1135 tablet}). When using the VNC display, you must use the @option{-k}
1136 parameter to set the keyboard layout if you are not using en-us. Valid
1137 syntax for the @var{display} is
1141 @item @var{host}:@var{d}
1143 TCP connections will only be allowed from @var{host} on display @var{d}.
1144 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1145 be omitted in which case the server will accept connections from any host.
1147 @item unix:@var{path}
1149 Connections will be allowed over UNIX domain sockets where @var{path} is the
1150 location of a unix socket to listen for connections on.
1154 VNC is initialized but not started. The monitor @code{change} command
1155 can be used to later start the VNC server.
1159 Following the @var{display} value there may be one or more @var{option} flags
1160 separated by commas. Valid options are
1166 Connect to a listening VNC client via a ``reverse'' connection. The
1167 client is specified by the @var{display}. For reverse network
1168 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1169 is a TCP port number, not a display number.
1173 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1174 By definition the Websocket port is 5700+@var{display}. If @var{host} is
1175 specified connections will only be allowed from this host.
1176 As an alternative the Websocket port could be specified by using
1177 @code{websocket}=@var{port}.
1178 TLS encryption for the Websocket connection is supported if the required
1179 certificates are specified with the VNC option @option{x509}.
1183 Require that password based authentication is used for client connections.
1185 The password must be set separately using the @code{set_password} command in
1186 the @ref{pcsys_monitor}. The syntax to change your password is:
1187 @code{set_password <protocol> <password>} where <protocol> could be either
1190 If you would like to change <protocol> password expiration, you should use
1191 @code{expire_password <protocol> <expiration-time>} where expiration time could
1192 be one of the following options: now, never, +seconds or UNIX time of
1193 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1194 to make password expire on "Mon Apr
23 12:00:00 EDT
2012" (UNIX time for this
1197 You can also use keywords "now
" or "never" for the expiration time to
1198 allow <protocol> password to expire immediately or never expire.
1202 Require that client use TLS when communicating with the VNC server. This
1203 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1204 attack. It is recommended that this option be combined with either the
1205 @option{x509} or @option{x509verify} options.
1207 @item x509=@var{/path/to/certificate/dir}
1209 Valid if @option{tls} is specified. Require that x509 credentials are used
1210 for negotiating the TLS session. The server will send its x509 certificate
1211 to the client. It is recommended that a password be set on the VNC server
1212 to provide authentication of the client when this is used. The path following
1213 this option specifies where the x509 certificates are to be loaded from.
1214 See the @ref{vnc_security} section for details on generating certificates.
1216 @item x509verify=@var{/path/to/certificate/dir}
1218 Valid if @option{tls} is specified. Require that x509 credentials are used
1219 for negotiating the TLS session. The server will send its x509 certificate
1220 to the client, and request that the client send its own x509 certificate.
1221 The server will validate the client's certificate against the CA certificate,
1222 and reject clients when validation fails. If the certificate authority is
1223 trusted, this is a sufficient authentication mechanism. You may still wish
1224 to set a password on the VNC server as a second authentication layer. The
1225 path following this option specifies where the x509 certificates are to
1226 be loaded from. See the @ref{vnc_security} section for details on generating
1231 Require that the client use SASL to authenticate with the VNC server.
1232 The exact choice of authentication method used is controlled from the
1233 system / user's SASL configuration file for the 'qemu' service. This
1234 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1235 unprivileged user, an environment variable SASL_CONF_PATH can be used
1236 to make it search alternate locations for the service config.
1237 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1238 it is recommended that SASL always be combined with the 'tls' and
1239 'x509' settings to enable use of SSL and server certificates. This
1240 ensures a data encryption preventing compromise of authentication
1241 credentials. See the @ref{vnc_security} section for details on using
1242 SASL authentication.
1246 Turn on access control lists for checking of the x509 client certificate
1247 and SASL party. For x509 certs, the ACL check is made against the
1248 certificate's distinguished name. This is something that looks like
1249 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1250 made against the username, which depending on the SASL plugin, may
1251 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1252 When the @option{acl} flag is set, the initial access list will be
1253 empty, with a @code{deny} policy. Thus no one will be allowed to
1254 use the VNC server until the ACLs have been loaded. This can be
1255 achieved using the @code{acl} monitor command.
1259 Enable lossy compression methods (gradient, JPEG, ...). If this
1260 option is set, VNC client may receive lossy framebuffer updates
1261 depending on its encoding settings. Enabling this option can save
1262 a lot of bandwidth at the expense of quality.
1266 Disable adaptive encodings. Adaptive encodings are enabled by default.
1267 An adaptive encoding will try to detect frequently updated screen regions,
1268 and send updates in these regions using a lossy encoding (like JPEG).
1269 This can be really helpful to save bandwidth when playing videos. Disabling
1270 adaptive encodings restores the original static behavior of encodings
1273 @item share=[allow-exclusive|force-shared|ignore]
1275 Set display sharing policy. 'allow-exclusive' allows clients to ask
1276 for exclusive access. As suggested by the rfb spec this is
1277 implemented by dropping other connections. Connecting multiple
1278 clients in parallel requires all clients asking for a shared session
1279 (vncviewer: -shared switch). This is the default. 'force-shared'
1280 disables exclusive client access. Useful for shared desktop sessions,
1281 where you don't want someone forgetting specify -shared disconnect
1282 everybody else. 'ignore' completely ignores the shared flag and
1283 allows everybody connect unconditionally. Doesn't conform to the rfb
1284 spec but is traditional QEMU behavior.
1292 ARCHHEADING(, QEMU_ARCH_I386)
1294 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1299 DEF("win2k
-hack
", 0, QEMU_OPTION_win2k_hack,
1300 "-win2k
-hack use it when installing Windows
2000 to avoid a disk full bug
\n",
1305 Use it when installing Windows 2000 to avoid a disk full bug. After
1306 Windows 2000 is installed, you no longer need this option (this option
1307 slows down the IDE transfers).
1310 HXCOMM Deprecated by -rtc
1311 DEF("rtc
-td
-hack
", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1313 DEF("no
-fd
-bootchk
", 0, QEMU_OPTION_no_fd_bootchk,
1314 "-no
-fd
-bootchk disable boot signature checking
for floppy disks
\n",
1317 @item -no-fd-bootchk
1318 @findex -no-fd-bootchk
1319 Disable boot signature checking for floppy disks in BIOS. May
1320 be needed to boot from old floppy disks.
1323 DEF("no
-acpi
", 0, QEMU_OPTION_no_acpi,
1324 "-no
-acpi disable ACPI
\n", QEMU_ARCH_I386)
1328 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1329 it if your guest OS complains about ACPI problems (PC target machine
1333 DEF("no
-hpet
", 0, QEMU_OPTION_no_hpet,
1334 "-no
-hpet disable HPET
\n", QEMU_ARCH_I386)
1338 Disable HPET support.
1341 DEF("acpitable
", HAS_ARG, QEMU_OPTION_acpitable,
1342 "-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"
1343 " ACPI table description
\n", QEMU_ARCH_I386)
1345 @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}]...]
1347 Add ACPI table with specified header fields and context from specified files.
1348 For file=, take whole ACPI table from the specified files, including all
1349 ACPI headers (possible overridden by other options).
1350 For data=, only data
1351 portion of the table is used, all header information is specified in the
1355 DEF("smbios
", HAS_ARG, QEMU_OPTION_smbios,
1356 "-smbios file
=binary
\n"
1357 " load SMBIOS entry from binary file
\n"
1358 "-smbios type
=0[,vendor
=str
][,version
=str
][,date
=str
][,release
=%d
.%d
][,uefi
=on|off
]\n"
1359 " specify SMBIOS type
0 fields
\n"
1360 "-smbios type
=1[,manufacturer
=str
][,product
=str
][,version
=str
][,serial
=str
]\n"
1361 " [,uuid
=uuid
][,sku
=str
][,family
=str
]\n"
1362 " specify SMBIOS type
1 fields
\n", QEMU_ARCH_I386)
1364 @item -smbios file=@var{binary}
1366 Load SMBIOS entry from binary file.
1368 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1369 Specify SMBIOS type 0 fields
1371 @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}]
1372 Specify SMBIOS type 1 fields
1380 DEFHEADING(Network options:)
1385 HXCOMM Legacy slirp options (now moved to -net user):
1387 DEF("tftp
", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1388 DEF("bootp
", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1389 DEF("redir
", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1391 DEF("smb
", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1395 DEF("net
", HAS_ARG, QEMU_OPTION_net,
1396 "-net nic
[,vlan
=n
][,macaddr
=mac
][,model
=type
][,name
=str
][,addr
=str
][,vectors
=v
]\n"
1397 " create a
new Network Interface Card and connect it to VLAN
'n'\n"
1399 "-net user
[,vlan
=n
][,name
=str
][,net
=addr
[/mask
]][,host
=addr
][,restrict
=on|off
]\n"
1400 " [,hostname
=host
][,dhcpstart
=addr
][,dns
=addr
][,dnssearch
=domain
][,tftp
=dir
]\n"
1401 " [,bootfile
=f
][,hostfwd
=rule
][,guestfwd
=rule
]"
1403 "[,smb
=dir
[,smbserver
=addr
]]\n"
1405 " connect the user mode network stack to VLAN
'n', configure its
\n"
1406 " DHCP server and enabled optional services
\n"
1409 "-net tap
[,vlan
=n
][,name
=str
],ifname
=name
\n"
1410 " connect the host TAP network
interface to VLAN
'n'\n"
1412 "-net tap
[,vlan
=n
][,name
=str
][,fd
=h
][,fds
=x
:y
:...:z
][,ifname
=name
][,script
=file
][,downscript
=dfile
][,helper
=helper
][,sndbuf
=nbytes
][,vnet_hdr
=on|off
][,vhost
=on|off
][,vhostfd
=h
][,vhostfds
=x
:y
:...:z
][,vhostforce
=on|off
][,queues
=n
]\n"
1413 " connect the host TAP network
interface to VLAN
'n'\n"
1414 " use network scripts
'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1415 " to configure it and
'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1416 " to deconfigure it
\n"
1417 " use
'[down]script=no' to disable script execution
\n"
1418 " use network helper
'helper' (default=" DEFAULT_BRIDGE_HELPER ") to
\n"
1420 " use
'fd=h' to connect to an already opened TAP
interface\n"
1421 " use
'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces
\n"
1422 " use
'sndbuf=nbytes' to limit the size of the send
buffer (the
\n"
1423 " default is disabled
'sndbuf=0' to enable flow control set
'sndbuf=1048576')\n"
1424 " use vnet_hdr
=off to avoid enabling the IFF_VNET_HDR tap flag
\n"
1425 " use vnet_hdr
=on to make the lack of IFF_VNET_HDR support an error condition
\n"
1426 " use vhost
=on to enable experimental
in kernel accelerator
\n"
1427 " (only has effect
for virtio guests which use MSIX
)\n"
1428 " use vhostforce
=on to force vhost on
for non
-MSIX virtio guests
\n"
1429 " use
'vhostfd=h' to connect to an already opened vhost net device
\n"
1430 " use
'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1431 " use 'queues
=n
' to specify the number of queues to be created for multiqueue TAP\n"
1432 "-net bridge[,vlan=n][,name=str][,br=bridge][,helper=helper]\n"
1433 " connects a host TAP network interface to a host bridge device 'br
'\n"
1434 " (default=" DEFAULT_BRIDGE_INTERFACE ") using the program 'helper
'\n"
1435 " (default=" DEFAULT_BRIDGE_HELPER ")\n"
1438 "-net l2tpv3[,vlan=n][,name=str],src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6=on/off][,udp=on/off][,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]\n"
1439 " connect the VLAN to an Ethernet over L2TPv3 pseudowire\n"
1440 " Linux kernel 3.3+ as well as most routers can talk\n"
1441 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1442 " VM to a router and even VM to Host. It is a nearly-universal\n"
1443 " standard (RFC3391). Note - this implementation uses static\n"
1444 " pre-configured tunnels (same as the Linux kernel).\n"
1445 " use 'src
=' to specify source address\n"
1446 " use 'dst
=' to specify destination address\n"
1447 " use 'udp
=on
' to specify udp encapsulation\n"
1448 " use 'srcport
=' to specify source udp port\n"
1449 " use 'dstport
=' to specify destination udp port\n"
1450 " use 'ipv6
=on
' to force v6\n"
1451 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1452 " well as a weak security measure\n"
1453 " use 'rxcookie
=0x012345678' to specify a rxcookie\n"
1454 " use 'txcookie
=0x012345678' to specify a txcookie\n"
1455 " use 'cookie64
=on
' to set cookie size to 64 bit, otherwise 32\n"
1456 " use 'counter
=off
' to force a 'cut
-down
' L2TPv3 with no counter\n"
1457 " use 'pincounter
=on
' to work around broken counter handling in peer\n"
1458 " use 'offset
=X
' to add an extra offset between header and data\n"
1460 "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
1461 " connect the vlan 'n
' to another VLAN using a socket connection\n"
1462 "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1463 " connect the vlan 'n
' to multicast maddr and port\n"
1464 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1465 "-net socket[,vlan=n][,name=str][,fd=h][,udp=host:port][,localaddr=host:port]\n"
1466 " connect the vlan 'n
' to another VLAN using an UDP tunnel\n"
1468 "-net vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1469 " connect the vlan 'n
' to port 'n
' of a vde switch running\n"
1470 " on host and listening for incoming connections on 'socketpath
'.\n"
1471 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1472 " ownership and permissions for communication port.\n"
1474 #ifdef CONFIG_NETMAP
1475 "-net netmap,ifname=name[,devname=nmname]\n"
1476 " attach to the existing netmap-enabled network interface 'name
', or to a\n"
1477 " VALE port (created on the fly) called 'name
' ('nmname
' is name of the \n"
1478 " netmap device, defaults to '/dev
/netmap
')\n"
1480 "-net dump[,vlan=n][,file=f][,len=n]\n"
1481 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
1482 "-net none use it alone to have zero network devices. If no -net option\n"
1483 " is provided, the default is '-net nic
-net user
'\n", QEMU_ARCH_ALL)
1484 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1494 #ifdef CONFIG_NETMAP
1499 "hubport],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
1501 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1503 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1504 = 0 is the default). The NIC is an e1000 by default on the PC
1505 target. Optionally, the MAC address can be changed to @var{mac}, the
1506 device address set to @var{addr} (PCI cards only),
1507 and a @var{name} can be assigned for use in monitor commands.
1508 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1509 that the card should have; this option currently only affects virtio cards; set
1510 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1511 NIC is created. QEMU can emulate several different models of network card.
1512 Valid values for @var{type} are
1513 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1514 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1515 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1516 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1517 for a list of available devices for your target.
1519 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1521 @item -net user[,@var{option}][,@var{option}][,...]
1522 Use the user mode network stack which requires no administrator
1523 privilege to run. Valid options are:
1527 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1530 @item name=@var{name}
1531 Assign symbolic name for use in monitor commands.
1533 @item net=@var{addr}[/@var{mask}]
1534 Set IP network address the guest will see. Optionally specify the netmask,
1535 either in the form a.b.c.d or as number of valid top-most bits. Default is
1538 @item host=@var{addr}
1539 Specify the guest-visible address of the host. Default is the 2nd IP in the
1540 guest network, i.e. x.x.x.2.
1542 @item restrict=on|off
1543 If this option is enabled, the guest will be isolated, i.e. it will not be
1544 able to contact the host and no guest IP packets will be routed over the host
1545 to the outside. This option does not affect any explicitly set forwarding rules.
1547 @item hostname=@var{name}
1548 Specifies the client hostname reported by the built-in DHCP server.
1550 @item dhcpstart=@var{addr}
1551 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1552 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1554 @item dns=@var{addr}
1555 Specify the guest-visible address of the virtual nameserver. The address must
1556 be different from the host address. Default is the 3rd IP in the guest network,
1559 @item dnssearch=@var{domain}
1560 Provides an entry for the domain-search list sent by the built-in
1561 DHCP server. More than one domain suffix can be transmitted by specifying
1562 this option multiple times. If supported, this will cause the guest to
1563 automatically try to append the given domain suffix(es) in case a domain name
1564 can not be resolved.
1568 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1571 @item tftp=@var{dir}
1572 When using the user mode network stack, activate a built-in TFTP
1573 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1574 The TFTP client on the guest must be configured in binary mode (use the command
1575 @code{bin} of the Unix TFTP client).
1577 @item bootfile=@var{file}
1578 When using the user mode network stack, broadcast @var{file} as the BOOTP
1579 filename. In conjunction with @option{tftp}, this can be used to network boot
1580 a guest from a local directory.
1582 Example (using pxelinux):
1584 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1587 @item smb=@var{dir}[,smbserver=@var{addr}]
1588 When using the user mode network stack, activate a built-in SMB
1589 server so that Windows OSes can access to the host files in @file{@var{dir}}
1590 transparently. The IP address of the SMB server can be set to @var{addr}. By
1591 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1593 In the guest Windows OS, the line:
1597 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1598 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1600 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1602 Note that a SAMBA server must be installed on the host OS.
1603 QEMU was tested successfully with smbd versions from Red Hat 9,
1604 Fedora Core 3 and OpenSUSE 11.x.
1606 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1607 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1608 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1609 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1610 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1611 be bound to a specific host interface. If no connection type is set, TCP is
1612 used. This option can be given multiple times.
1614 For example, to redirect host X11 connection from screen 1 to guest
1615 screen 0, use the following:
1619 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1620 # this host xterm should open in the guest X11 server
1624 To redirect telnet connections from host port 5555 to telnet port on
1625 the guest, use the following:
1629 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1630 telnet localhost 5555
1633 Then when you use on the host @code{telnet localhost 5555}, you
1634 connect to the guest telnet server.
1636 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1637 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1638 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1639 to the character device @var{dev} or to a program executed by @var{cmd:command}
1640 which gets spawned for each connection. This option can be given multiple times.
1642 You can either use a chardev directly and have that one used throughout QEMU's
1643 lifetime
, like
in the following example
:
1646 # open
10.10.1.1:4321 on bootup
, connect
10.0.2.100:1234 to it whenever
1647 # the guest accesses it
1648 qemu
-net user
,guestfwd
=tcp
:10.0.2.100:1234-tcp
:10.10.1.1:4321 [...]
1651 Or you can execute a command on every TCP connection established by the guest
,
1652 so that QEMU behaves similar to an inetd process
for that virtual server
:
1655 # call
"netcat 10.10.1.1 4321" on every TCP connection to
10.0.2.100:1234
1656 # and connect the TCP stream to its stdin
/stdout
1657 qemu
-net
'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1662 Note
: Legacy stand
-alone options
-tftp
, -bootp
, -smb and
-redir are still
1663 processed and applied to
-net user
. Mixing them with the
new configuration
1664 syntax gives undefined results
. Their use
for new applications is discouraged
1665 as they will be removed from future versions
.
1667 @item
-netdev tap
,id
=@
var{id
}[,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1668 @item
-net tap
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,helper
=@
var{helper
}]
1669 Connect the host TAP network
interface @
var{name
} to VLAN @
var{n
}.
1671 Use the network script @
var{file
} to configure it and the network script
1672 @
var{dfile
} to deconfigure it
. If @
var{name
} is not provided
, the OS
1673 automatically provides one
. The
default network configure script is
1674 @file
{/etc
/qemu
-ifup
} and the
default network deconfigure script is
1675 @file
{/etc
/qemu
-ifdown
}. Use @option
{script
=no
} or @option
{downscript
=no
}
1676 to disable script execution
.
1678 If running QEMU as an unprivileged user
, use the network helper
1679 @
var{helper
} to configure the TAP
interface. The
default network
1680 helper executable is @file
{/path
/to
/qemu
-bridge
-helper
}.
1682 @option
{fd
}=@
var{h
} can be used to specify the handle of an already
1683 opened host TAP
interface.
1688 #launch a QEMU instance with the
default network script
1689 qemu
-system
-i386 linux
.img
-net nic
-net tap
1693 #launch a QEMU instance with two NICs
, each one connected
1695 qemu
-system
-i386 linux
.img \
1696 -net nic
,vlan
=0 -net tap
,vlan
=0,ifname
=tap0 \
1697 -net nic
,vlan
=1 -net tap
,vlan
=1,ifname
=tap1
1701 #launch a QEMU instance with the
default network helper to
1702 #connect a TAP device to bridge br0
1703 qemu
-system
-i386 linux
.img \
1704 -net nic
-net tap
,"helper=/path/to/qemu-bridge-helper"
1707 @item
-netdev bridge
,id
=@
var{id
}[,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1708 @item
-net bridge
[,vlan
=@
var{n
}][,name
=@
var{name
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
1709 Connect a host TAP network
interface to a host bridge device
.
1711 Use the network helper @
var{helper
} to configure the TAP
interface and
1712 attach it to the bridge
. The
default network helper executable is
1713 @file
{/path
/to
/qemu
-bridge
-helper
} and the
default bridge
1714 device is @file
{br0
}.
1719 #launch a QEMU instance with the
default network helper to
1720 #connect a TAP device to bridge br0
1721 qemu
-system
-i386 linux
.img
-net bridge
-net nic
,model
=virtio
1725 #launch a QEMU instance with the
default network helper to
1726 #connect a TAP device to bridge qemubr0
1727 qemu
-system
-i386 linux
.img
-net bridge
,br
=qemubr0
-net nic
,model
=virtio
1730 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1731 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}] [,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
1733 Connect the VLAN @
var{n
} to a remote VLAN
in another QEMU virtual
1734 machine
using a TCP socket connection
. If @option
{listen
} is
1735 specified
, QEMU waits
for incoming connections on @
var{port
}
1736 (@
var{host
} is optional
). @option
{connect
} is used to connect to
1737 another QEMU instance
using the @option
{listen
} option
. @option
{fd
}=@
var{h
}
1738 specifies an already opened TCP socket
.
1742 # launch a first QEMU instance
1743 qemu
-system
-i386 linux
.img \
1744 -net nic
,macaddr
=52:54:00:12:34:56 \
1745 -net socket
,listen
=:1234
1746 # connect the VLAN
0 of
this instance to the VLAN
0
1747 # of the first instance
1748 qemu
-system
-i386 linux
.img \
1749 -net nic
,macaddr
=52:54:00:12:34:57 \
1750 -net socket
,connect
=127.0.0.1:1234
1753 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1754 @item
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
1756 Create a VLAN @
var{n
} shared with another QEMU virtual
1757 machines
using a UDP multicast socket
, effectively making a bus
for
1758 every QEMU with same multicast address @
var{maddr
} and @
var{port
}.
1762 Several QEMU can be running on different hosts and share same
bus (assuming
1763 correct multicast setup
for these hosts
).
1765 mcast support is compatible with User Mode
Linux (argument @option
{eth@
var{N
}=mcast
}), see
1766 @url
{http
://user-mode-linux.sf.net}.
1768 Use @option
{fd
=h
} to specify an already opened UDP multicast socket
.
1773 # launch one QEMU instance
1774 qemu
-system
-i386 linux
.img \
1775 -net nic
,macaddr
=52:54:00:12:34:56 \
1776 -net socket
,mcast
=230.0.0.1:1234
1777 # launch another QEMU instance on same
"bus"
1778 qemu
-system
-i386 linux
.img \
1779 -net nic
,macaddr
=52:54:00:12:34:57 \
1780 -net socket
,mcast
=230.0.0.1:1234
1781 # launch yet another QEMU instance on same
"bus"
1782 qemu
-system
-i386 linux
.img \
1783 -net nic
,macaddr
=52:54:00:12:34:58 \
1784 -net socket
,mcast
=230.0.0.1:1234
1787 Example (User Mode Linux compat
.):
1789 # launch QEMU
instance (note mcast address selected
1791 qemu-system-i386 linux.img \
1792 -net nic,macaddr=52:54:00:12:34:56 \
1793 -net socket,mcast=239.192.168.1:1102
1795 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1798 Example (send packets from host's
1.2.3.4):
1800 qemu
-system
-i386 linux
.img \
1801 -net nic
,macaddr
=52:54:00:12:34:56 \
1802 -net socket
,mcast
=239.192.168.1:1102,localaddr
=1.2.3.4
1805 @item
-netdev l2tpv3
,id
=@
var{id
},src
=@
var{srcaddr
},dst
=@
var{dstaddr
}[,srcport
=@
var{srcport
}][,dstport
=@
var{dstport
}],txsession
=@
var{txsession
}[,rxsession
=@
var{rxsession
}][,ipv6
][,udp
][,cookie64
][,counter
][,pincounter
][,txcookie
=@
var{txcookie
}][,rxcookie
=@
var{rxcookie
}][,offset
=@
var{offset
}]
1806 @item
-net l2tpv3
[,vlan
=@
var{n
}][,name
=@
var{name
}],src
=@
var{srcaddr
},dst
=@
var{dstaddr
}[,srcport
=@
var{srcport
}][,dstport
=@
var{dstport
}],txsession
=@
var{txsession
}[,rxsession
=@
var{rxsession
}][,ipv6
][,udp
][,cookie64
][,counter
][,pincounter
][,txcookie
=@
var{txcookie
}][,rxcookie
=@
var{rxcookie
}][,offset
=@
var{offset
}]
1807 Connect VLAN @
var{n
} to L2TPv3 pseudowire
. L2TPv3 (RFC3391
) is a popular
1808 protocol to transport
Ethernet (and other Layer
2) data frames between
1809 two systems
. It is present
in routers
, firewalls and the Linux kernel
1810 (from version
3.3 onwards
).
1812 This transport allows a VM to communicate to another VM
, router or firewall directly
.
1814 @item src
=@
var{srcaddr
}
1815 source
address (mandatory
)
1816 @item dst
=@
var{dstaddr
}
1817 destination
address (mandatory
)
1819 select udp
encapsulation (default is ip
).
1820 @item srcport
=@
var{srcport
}
1822 @item dstport
=@
var{dstport
}
1823 destination udp port
.
1825 force v6
, otherwise defaults to v4
.
1826 @item rxcookie
=@
var{rxcookie
}
1827 @item txcookie
=@
var{txcookie
}
1828 Cookies are a weak form of security
in the l2tpv3 specification
.
1829 Their
function is mostly to prevent misconfiguration
. By
default they are
32
1832 Set cookie size to
64 bit instead of the
default 32
1834 Force a
'cut-down' L2TPv3 with no counter as
in
1835 draft
-mkonstan
-l2tpext
-keyed
-ipv6
-tunnel
-00
1837 Work around broken counter handling
in peer
. This may also help on
1838 networks which have packet reorder
.
1839 @item offset
=@
var{offset
}
1840 Add an extra offset between header and data
1842 For example
, to attach a VM running on host
4.3.2.1 via L2TPv3 to the bridge br
-lan
1843 on the remote Linux host
1.2.3.4:
1845 # Setup tunnel on linux host
using raw ip as encapsulation
1847 ip l2tp add tunnel remote
4.3.2.1 local
1.2.3.4 tunnel_id
1 peer_tunnel_id
1 \
1848 encap udp udp_sport
16384 udp_dport
16384
1849 ip l2tp add session tunnel_id
1 name vmtunnel0 session_id \
1850 0xFFFFFFFF peer_session_id
0xFFFFFFFF
1851 ifconfig vmtunnel0 mtu
1500
1852 ifconfig vmtunnel0 up
1853 brctl addif br
-lan vmtunnel0
1857 # launch QEMU instance
- if your network has reorder or is very lossy add
,pincounter
1859 qemu
-system
-i386 linux
.img
-net nic
-net l2tpv3
,src
=4.2.3.1,dst
=1.2.3.4,udp
,srcport
=16384,dstport
=16384,rxsession
=0xffffffff,txsession
=0xffffffff,counter
1864 @item
-netdev vde
,id
=@
var{id
}[,sock
=@
var{socketpath
}][,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1865 @item
-net vde
[,vlan
=@
var{n
}][,name
=@
var{name
}][,sock
=@
var{socketpath
}] [,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
1866 Connect VLAN @
var{n
} to PORT @
var{n
} of a vde
switch running on host and
1867 listening
for incoming connections on @
var{socketpath
}. Use GROUP @
var{groupname
}
1868 and MODE @
var{octalmode
} to change
default ownership and permissions
for
1869 communication port
. This option is only available
if QEMU has been compiled
1870 with vde support enabled
.
1875 vde_switch
-F
-sock
/tmp
/myswitch
1876 # launch QEMU instance
1877 qemu
-system
-i386 linux
.img
-net nic
-net vde
,sock
=/tmp
/myswitch
1880 @item
-netdev hubport
,id
=@
var{id
},hubid
=@
var{hubid
}
1882 Create a hub port on QEMU
"vlan" @
var{hubid
}.
1884 The hubport netdev lets you connect a NIC to a QEMU
"vlan" instead of a single
1885 netdev
. @code
{-net
} and @code
{-device
} with parameter @option
{vlan
} create the
1886 required hub automatically
.
1888 @item
-netdev vhost
-user
,chardev
=@
var{id
}[,vhostforce
=on|off
]
1890 Establish a vhost
-user netdev
, backed by a chardev @
var{id
}. The chardev should
1891 be a unix domain socket backed one
. The vhost
-user uses a specifically defined
1892 protocol to pass vhost ioctl replacement messages to an application on the other
1893 end of the socket
. On non
-MSIX guests
, the feature can be forced with
1898 qemu
-m
512 -object memory
-backend
-file
,id
=mem
,size
=512M
,mem
-path
=/hugetlbfs
,share
=on \
1899 -numa node
,memdev
=mem \
1900 -chardev socket
,path
=/path
/to
/socket \
1901 -netdev type
=vhost
-user
,id
=net0
,chardev
=chr0 \
1902 -device virtio
-net
-pci
,netdev
=net0
1905 @item
-net dump
[,vlan
=@
var{n
}][,file
=@
var{file
}][,len
=@
var{len
}]
1906 Dump network traffic on VLAN @
var{n
} to file @
var{file
} (@file
{qemu
-vlan0
.pcap
} by
default).
1907 At most @
var{len
} bytes (64k by
default) per packet are stored
. The file format is
1908 libpcap
, so it can be analyzed with tools such as tcpdump or Wireshark
.
1911 Indicate that no network devices should be configured
. It is used to
1912 override the
default configuration (@option
{-net nic
-net user
}) which
1913 is activated
if no @option
{-net
} options are provided
.
1921 DEFHEADING(Character device options
:)
1924 The general form of a character device option is
:
1928 DEF("chardev", HAS_ARG
, QEMU_OPTION_chardev
,
1929 "-chardev null,id=id[,mux=on|off]\n"
1930 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay]\n"
1931 " [,server][,nowait][,telnet][,mux=on|off] (tcp)\n"
1932 "-chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix)\n"
1933 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
1934 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
1935 "-chardev msmouse,id=id[,mux=on|off]\n"
1936 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
1938 "-chardev ringbuf,id=id[,size=size]\n"
1939 "-chardev file,id=id,path=path[,mux=on|off]\n"
1940 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
1942 "-chardev console,id=id[,mux=on|off]\n"
1943 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1945 "-chardev pty,id=id[,mux=on|off]\n"
1946 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
1948 #ifdef CONFIG_BRLAPI
1949 "-chardev braille,id=id[,mux=on|off]\n"
1951 #
if defined(__linux__
) ||
defined(__sun__
) ||
defined(__FreeBSD__
) \
1952 ||
defined(__NetBSD__
) ||
defined(__OpenBSD__
) ||
defined(__DragonFly__
)
1953 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1954 "-chardev tty,id=id,path=path[,mux=on|off]\n"
1956 #
if defined(__linux__
) ||
defined(__FreeBSD__
) ||
defined(__DragonFly__
)
1957 "-chardev parallel,id=id,path=path[,mux=on|off]\n"
1958 "-chardev parport,id=id,path=path[,mux=on|off]\n"
1960 #
if defined(CONFIG_SPICE
)
1961 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
1962 "-chardev spiceport,id=id,name=name[,debug=debug]\n"
1968 @item
-chardev @
var{backend
} ,id
=@
var{id
} [,mux
=on|off
] [,@
var{options
}]
1989 The specific backend will determine the applicable options
.
1991 All devices must have an id
, which can be any string up to
127 characters long
.
1992 It is used to uniquely identify
this device
in other command line directives
.
1994 A character device may be used
in multiplexing mode by multiple front
-ends
.
1995 The key sequence of @key
{Control
-a
} and @key
{c
} will rotate the input focus
1996 between attached front
-ends
. Specify @option
{mux
=on
} to enable
this mode
.
1998 Options to each backend are described below
.
2000 @item
-chardev
null ,id
=@
var{id
}
2001 A void device
. This device will not emit any data
, and will drop any data it
2002 receives
. The
null backend does not take any options
.
2004 @item
-chardev socket
,id
=@
var{id
} [@
var{TCP options
} or @
var{unix options
}] [,server
] [,nowait
] [,telnet
]
2006 Create a two
-way stream socket
, which can be either a TCP or a unix socket
. A
2007 unix socket will be created
if @option
{path
} is specified
. Behaviour is
2008 undefined
if TCP options are specified
for a unix socket
.
2010 @option
{server
} specifies that the socket shall be a listening socket
.
2012 @option
{nowait
} specifies that QEMU should not block waiting
for a client to
2013 connect to a listening socket
.
2015 @option
{telnet
} specifies that traffic on the socket should interpret telnet
2018 TCP and unix socket options are given below
:
2022 @item TCP options
: port
=@
var{port
} [,host
=@
var{host
}] [,to
=@
var{to
}] [,ipv4
] [,ipv6
] [,nodelay
]
2024 @option
{host
} for a listening socket specifies the local address to be bound
.
2025 For a connecting socket species the remote host to connect to
. @option
{host
} is
2026 optional
for listening sockets
. If not specified it defaults to @code
{0.0.0.0}.
2028 @option
{port
} for a listening socket specifies the local port to be bound
. For a
2029 connecting socket specifies the port on the remote host to connect to
.
2030 @option
{port
} can be given as either a port number or a service name
.
2031 @option
{port
} is required
.
2033 @option
{to
} is only relevant to listening sockets
. If it is specified
, and
2034 @option
{port
} cannot be bound
, QEMU will attempt to bind to subsequent ports up
2035 to and including @option
{to
} until it succeeds
. @option
{to
} must be specified
2038 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2039 If neither is specified the socket may use either protocol
.
2041 @option
{nodelay
} disables the Nagle algorithm
.
2043 @item unix options
: path
=@
var{path
}
2045 @option
{path
} specifies the local path of the unix socket
. @option
{path
} is
2050 @item
-chardev udp
,id
=@
var{id
} [,host
=@
var{host
}] ,port
=@
var{port
} [,localaddr
=@
var{localaddr
}] [,localport
=@
var{localport
}] [,ipv4
] [,ipv6
]
2052 Sends all traffic from the guest to a remote host over UDP
.
2054 @option
{host
} specifies the remote host to connect to
. If not specified it
2055 defaults to @code
{localhost
}.
2057 @option
{port
} specifies the port on the remote host to connect to
. @option
{port
}
2060 @option
{localaddr
} specifies the local address to bind to
. If not specified it
2061 defaults to @code
{0.0.0.0}.
2063 @option
{localport
} specifies the local port to bind to
. If not specified any
2064 available local port will be used
.
2066 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2067 If neither is specified the device may use either protocol
.
2069 @item
-chardev msmouse
,id
=@
var{id
}
2071 Forward QEMU
's emulated msmouse events to the guest. @option{msmouse} does not
2074 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2076 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2079 @option{width} and @option{height} specify the width and height respectively of
2080 the console, in pixels.
2082 @option{cols} and @option{rows} specify that the console be sized to fit a text
2083 console with the given dimensions.
2085 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2087 Create a ring buffer with fixed size @option{size}.
2088 @var{size} must be a power of two, and defaults to @code{64K}).
2090 @item -chardev file ,id=@var{id} ,path=@var{path}
2092 Log all traffic received from the guest to a file.
2094 @option{path} specifies the path of the file to be opened. This file will be
2095 created if it does not already exist, and overwritten if it does. @option{path}
2098 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2100 Create a two-way connection to the guest. The behaviour differs slightly between
2101 Windows hosts and other hosts:
2103 On Windows, a single duplex pipe will be created at
2104 @file{\\.pipe\@option{path}}.
2106 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2107 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2108 received by the guest. Data written by the guest can be read from
2109 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2112 @option{path} forms part of the pipe path as described above. @option{path} is
2115 @item -chardev console ,id=@var{id}
2117 Send traffic from the guest to QEMU's standard output
. @option
{console
} does not
2120 @option
{console
} is only available on Windows hosts
.
2122 @item
-chardev serial
,id
=@
var{id
} ,path
=@option
{path
}
2124 Send traffic from the guest to a serial device on the host
.
2126 On Unix hosts serial will actually accept any tty device
,
2127 not only serial lines
.
2129 @option
{path
} specifies the name of the serial device to open
.
2131 @item
-chardev pty
,id
=@
var{id
}
2133 Create a
new pseudo
-terminal on the host and connect to it
. @option
{pty
} does
2134 not take any options
.
2136 @option
{pty
} is not available on Windows hosts
.
2138 @item
-chardev stdio
,id
=@
var{id
} [,signal
=on|off
]
2139 Connect to standard input and standard output of the QEMU process
.
2141 @option
{signal
} controls
if signals are enabled on the terminal
, that includes
2142 exiting QEMU with the key sequence @key
{Control
-c
}. This option is enabled by
2143 default, use @option
{signal
=off
} to disable it
.
2145 @option
{stdio
} is not available on Windows hosts
.
2147 @item
-chardev braille
,id
=@
var{id
}
2149 Connect to a local BrlAPI server
. @option
{braille
} does not take any options
.
2151 @item
-chardev tty
,id
=@
var{id
} ,path
=@
var{path
}
2153 @option
{tty
} is only available on Linux
, Sun
, FreeBSD
, NetBSD
, OpenBSD and
2154 DragonFlyBSD hosts
. It is an alias
for @option
{serial
}.
2156 @option
{path
} specifies the path to the tty
. @option
{path
} is required
.
2158 @item
-chardev parallel
,id
=@
var{id
} ,path
=@
var{path
}
2159 @item
-chardev parport
,id
=@
var{id
} ,path
=@
var{path
}
2161 @option
{parallel
} is only available on Linux
, FreeBSD and DragonFlyBSD hosts
.
2163 Connect to a local parallel port
.
2165 @option
{path
} specifies the path to the parallel port device
. @option
{path
} is
2168 @item
-chardev spicevmc
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2170 @option
{spicevmc
} is only available when spice support is built
in.
2172 @option
{debug
} debug level
for spicevmc
2174 @option
{name
} name of spice channel to connect to
2176 Connect to a spice virtual machine channel
, such as vdiport
.
2178 @item
-chardev spiceport
,id
=@
var{id
} ,debug
=@
var{debug
}, name
=@
var{name
}
2180 @option
{spiceport
} is only available when spice support is built
in.
2182 @option
{debug
} debug level
for spicevmc
2184 @option
{name
} name of spice port to connect to
2186 Connect to a spice port
, allowing a Spice client to handle the traffic
2187 identified by a
name (preferably a fqdn
).
2195 DEFHEADING(Device URL Syntax
:)
2198 In addition to
using normal file images
for the emulated storage devices
,
2199 QEMU can also use networked resources such as iSCSI devices
. These are
2200 specified
using a special URL syntax
.
2204 iSCSI support allows QEMU to access iSCSI resources directly and use as
2205 images
for the guest storage
. Both disk and cdrom images are supported
.
2207 Syntax
for specifying iSCSI LUNs is
2208 ``iscsi
://<target-ip>[:<port>]/<target-iqn>/<lun>''
2210 By
default qemu will use the iSCSI initiator
-name
2211 'iqn.2008-11.org.linux-kvm[:<name>]' but
this can also be set from the command
2212 line or a configuration file
.
2215 Example (without authentication
):
2217 qemu
-system
-i386
-iscsi initiator
-name
=iqn
.2001-04.com
.example
:my
-initiator \
2218 -cdrom iscsi
://192.0.2.1/iqn.2001-04.com.example/2 \
2219 -drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2222 Example (CHAP username
/password via URL
):
2224 qemu
-system
-i386
-drive file
=iscsi
://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2227 Example (CHAP username
/password via environment variables
):
2229 LIBISCSI_CHAP_USERNAME
="user" \
2230 LIBISCSI_CHAP_PASSWORD
="password" \
2231 qemu
-system
-i386
-drive file
=iscsi
://192.0.2.1/iqn.2001-04.com.example/1
2234 iSCSI support is an optional feature of QEMU and only available when
2235 compiled and linked against libiscsi
.
2237 DEF("iscsi", HAS_ARG
, QEMU_OPTION_iscsi
,
2238 "-iscsi [user=user][,password=password]\n"
2239 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2240 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2241 " iSCSI session parameters\n", QEMU_ARCH_ALL
)
2244 iSCSI parameters such as username and password can also be specified via
2245 a configuration file
. See qemu
-doc
for more information and examples
.
2248 QEMU supports
NBD (Network Block Devices
) both
using TCP protocol as well
2249 as Unix Domain Sockets
.
2251 Syntax
for specifying a NBD device
using TCP
2252 ``nbd
:<server
-ip
>:<port
>[:exportname
=<export
>]''
2254 Syntax
for specifying a NBD device
using Unix Domain Sockets
2255 ``nbd
:unix
:<domain
-socket
>[:exportname
=<export
>]''
2260 qemu
-system
-i386
--drive file
=nbd
:192.0.2.1:30000
2263 Example
for Unix Domain Sockets
2265 qemu
-system
-i386
--drive file
=nbd
:unix
:/tmp
/nbd
-socket
2269 QEMU supports
SSH (Secure Shell
) access to remote disks
.
2273 qemu
-system
-i386
-drive file
=ssh
://user@@host/path/to/disk.img
2274 qemu
-system
-i386
-drive file
.driver
=ssh
,file
.user
=user
,file
.host
=host
,file
.port
=22,file
.path
=/path
/to
/disk
.img
2277 Currently authentication must be done
using ssh
-agent
. Other
2278 authentication methods may be supported
in future
.
2281 Sheepdog is a distributed storage system
for QEMU
.
2282 QEMU supports
using either local sheepdog devices or remote networked
2285 Syntax
for specifying a sheepdog device
2287 sheepdog
[+tcp|
+unix
]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2292 qemu
-system
-i386
--drive file
=sheepdog
://192.0.2.1:30000/MyVirtualMachine
2295 See also @url
{http
://http://www.osrg.net/sheepdog/}.
2298 GlusterFS is an user space distributed file system
.
2299 QEMU supports the use of GlusterFS volumes
for hosting VM disk images
using
2300 TCP
, Unix Domain Sockets and RDMA transport protocols
.
2302 Syntax
for specifying a VM disk image on GlusterFS volume is
2304 gluster
[+transport
]://[server[:port]]/volname/image[?socket=...]
2310 qemu
-system
-x86_64
--drive file
=gluster
://192.0.2.1/testvol/a.img
2313 See also @url
{http
://www.gluster.org}.
2315 @item HTTP
/HTTPS
/FTP
/FTPS
/TFTP
2316 QEMU supports read
-only access to files accessed over
http(s
), ftp(s
) and tftp
.
2318 Syntax
using a single filename
:
2320 <protocol
>://[<username>[:<password>]@@]<host>/<path>
2326 'http', 'https', 'ftp', 'ftps', or
'tftp'.
2329 Optional username
for authentication to the remote server
.
2332 Optional password
for authentication to the remote server
.
2335 Address of the remote server
.
2338 Path on the remote server
, including any query string
.
2341 The following options are also supported
:
2344 The full URL when passing options to the driver explicitly
.
2347 The amount of data to read ahead with each range request to the remote server
.
2348 This value may optionally have the suffix
'T', 'G', 'M', 'K', 'k' or
'b'. If it
2349 does not have a suffix
, it will be assumed to be
in bytes
. The value must be a
2350 multiple of
512 bytes
. It defaults to
256k
.
2353 Whether to verify the remote server
's certificate when connecting over SSL. It
2354 can have the value 'on
' or 'off
'. It defaults to 'on
'.
2357 Send this cookie (it can also be a list of cookies separated by ';') with
2358 each outgoing request. Only supported when using protocols such as HTTP
2359 which support cookies, otherwise ignored.
2362 Set the timeout in seconds of the CURL connection. This timeout is the time
2363 that CURL waits for a response from the remote server to get the size of the
2364 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2367 Note that when passing options to qemu explicitly, @option{driver} is the value
2370 Example: boot from a remote Fedora 20 live ISO image
2372 qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2374 qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2377 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2378 writes, copy-on-read, and a readahead of 64k
2380 qemu-img create -f qcow2 -o backing_file='json
:@
{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@
}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2
2382 qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
2385 Example: boot from an image stored on a VMware vSphere server with a self-signed
2386 certificate using a local overlay for writes, a readahead of 64k and a timeout
2389 qemu-img create -f qcow2 -o backing_file='json
:@
{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@
}' /tmp/test.qcow2
2391 qemu-system-x86_64 -drive file=/tmp/test.qcow2
2399 DEFHEADING(Bluetooth(R) options:)
2404 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2405 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands
\n" \
2406 "-bt hci
,host
[:id
]\n" \
2407 " use host
's HCI with the given name\n" \
2408 "-bt hci[,vlan=n]\n" \
2409 " emulate a standard HCI in virtual scatternet 'n
'\n" \
2410 "-bt vhci[,vlan=n]\n" \
2411 " add host computer to virtual scatternet 'n
' using VHCI\n" \
2412 "-bt device:dev[,vlan=n]\n" \
2413 " emulate a bluetooth device 'dev
' in scatternet 'n
'\n",
2418 Defines the function of the corresponding Bluetooth HCI. -bt options
2419 are matched with the HCIs present in the chosen machine type. For
2420 example when emulating a machine with only one HCI built into it, only
2421 the first @code{-bt hci[...]} option is valid and defines the HCI's
2422 logic
. The Transport Layer is decided by the machine type
. Currently
2423 the machines @code
{n800
} and @code
{n810
} have one HCI and all other
2427 The following three types are recognized
:
2431 (default) The corresponding Bluetooth HCI assumes no internal logic
2432 and will not respond to any HCI commands or emit events
.
2434 @item
-bt hci
,host
[:@
var{id
}]
2435 (@code
{bluez
} only
) The corresponding HCI passes commands
/ events
2436 to
/ from the physical HCI identified by the name @
var{id
} (default:
2437 @code
{hci0
}) on the computer running QEMU
. Only available on @code
{bluez
}
2438 capable systems like Linux
.
2440 @item
-bt hci
[,vlan
=@
var{n
}]
2441 Add a virtual
, standard HCI that will participate
in the Bluetooth
2442 scatternet @
var{n
} (default @code
{0}). Similarly to @option
{-net
}
2443 VLANs
, devices inside a bluetooth network @
var{n
} can only communicate
2444 with other devices
in the same
network (scatternet
).
2447 @item
-bt vhci
[,vlan
=@
var{n
}]
2448 (Linux
-host only
) Create a HCI
in scatternet @
var{n
} (default 0) attached
2449 to the host bluetooth stack instead of to the emulated target
. This
2450 allows the host and target machines to participate
in a common scatternet
2451 and communicate
. Requires the Linux @code
{vhci
} driver installed
. Can
2452 be used as following
:
2455 qemu
-system
-i386
[...OPTIONS
...] -bt hci
,vlan
=5 -bt vhci
,vlan
=5
2458 @item
-bt device
:@
var{dev
}[,vlan
=@
var{n
}]
2459 Emulate a bluetooth device @
var{dev
} and place it
in network @
var{n
}
2460 (default @code
{0}). QEMU can only emulate one type of bluetooth devices
2465 Virtual wireless keyboard implementing the HIDP bluetooth profile
.
2475 DEFHEADING(TPM device options
:)
2477 DEF("tpmdev", HAS_ARG
, QEMU_OPTION_tpmdev
, \
2478 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2479 " use path to provide path to a character device; default is /dev/tpm0\n"
2480 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2481 " not provided it will be searched for in /sys/class/misc/tpm?/device\n",
2485 The general form of a TPM device option is
:
2488 @item
-tpmdev @
var{backend
} ,id
=@
var{id
} [,@
var{options
}]
2490 Backend type must be
:
2491 @option
{passthrough
}.
2493 The specific backend type will determine the applicable options
.
2494 The @code
{-tpmdev
} option creates the TPM backend and requires a
2495 @code
{-device
} option that specifies the TPM frontend
interface model
.
2497 Options to each backend are described below
.
2499 Use
'help' to print all available TPM backend types
.
2504 @item
-tpmdev passthrough
, id
=@
var{id
}, path
=@
var{path
}, cancel
-path
=@
var{cancel
-path
}
2506 (Linux
-host only
) Enable access to the host
's TPM using the passthrough
2509 @option{path} specifies the path to the host's TPM device
, i
.e
., on
2510 a Linux host
this would be @code
{/dev
/tpm0
}.
2511 @option
{path
} is optional and by
default @code
{/dev
/tpm0
} is used
.
2513 @option
{cancel
-path
} specifies the path to the host TPM device
's sysfs
2514 entry allowing for cancellation of an ongoing TPM command.
2515 @option{cancel-path} is optional and by default QEMU will search for the
2518 Some notes about using the host's TPM with the passthrough driver
:
2520 The TPM device accessed by the passthrough driver must not be
2521 used by any other application on the host
.
2523 Since the host
's firmware (BIOS/UEFI) has already initialized the TPM,
2524 the VM's
firmware (BIOS
/UEFI
) will not be able to initialize the
2525 TPM again and may therefore not show a TPM
-specific menu that would
2526 otherwise allow the user to configure the TPM
, e
.g
., allow the user to
2527 enable
/disable or activate
/deactivate the TPM
.
2528 Further
, if TPM ownership is released from within a VM then the host
's TPM
2529 will get disabled and deactivated. To enable and activate the
2530 TPM again afterwards, the host has to be rebooted and the user is
2531 required to enter the firmware's menu to enable and activate the TPM
.
2532 If the TPM is left disabled and
/or deactivated most TPM commands will fail
.
2534 To create a passthrough TPM use the following two options
:
2536 -tpmdev passthrough
,id
=tpm0
-device tpm
-tis
,tpmdev
=tpm0
2538 Note that the @code
{-tpmdev
} id is @code
{tpm0
} and is referenced by
2539 @code
{tpmdev
=tpm0
} in the device option
.
2549 DEFHEADING(Linux
/Multiboot boot specific
:)
2552 When
using these options
, you can use a given Linux or Multiboot
2553 kernel without installing it
in the disk image
. It can be useful
2554 for easier testing of various kernels
.
2559 DEF("kernel", HAS_ARG
, QEMU_OPTION_kernel
, \
2560 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL
)
2562 @item
-kernel @
var{bzImage
}
2564 Use @
var{bzImage
} as kernel image
. The kernel can be either a Linux kernel
2565 or
in multiboot format
.
2568 DEF("append", HAS_ARG
, QEMU_OPTION_append
, \
2569 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL
)
2571 @item
-append @
var{cmdline
}
2573 Use @
var{cmdline
} as kernel command line
2576 DEF("initrd", HAS_ARG
, QEMU_OPTION_initrd
, \
2577 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL
)
2579 @item
-initrd @
var{file
}
2581 Use @
var{file
} as initial ram disk
.
2583 @item
-initrd
"@var{file1} arg=foo,@var{file2}"
2585 This syntax is only available with multiboot
.
2587 Use @
var{file1
} and @
var{file2
} as modules and pass arg
=foo as parameter to the
2591 DEF("dtb", HAS_ARG
, QEMU_OPTION_dtb
, \
2592 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL
)
2594 @item
-dtb @
var{file
}
2596 Use @
var{file
} as a device tree
binary (dtb
) image and pass it to the kernel
2605 DEFHEADING(Debug
/Expert options
:)
2610 DEF("serial", HAS_ARG
, QEMU_OPTION_serial
, \
2611 "-serial dev redirect the serial port to char device 'dev'\n",
2614 @item
-serial @
var{dev
}
2616 Redirect the virtual serial port to host character device
2617 @
var{dev
}. The
default device is @code
{vc
} in graphical mode and
2618 @code
{stdio
} in non graphical mode
.
2620 This option can be used several times to simulate up to
4 serial
2623 Use @code
{-serial none
} to disable all serial ports
.
2625 Available character devices are
:
2627 @item vc
[:@
var{W
}x@
var{H
}]
2628 Virtual console
. Optionally
, a width and height can be given
in pixel with
2632 It is also possible to specify width or height
in characters
:
2637 [Linux only
] Pseudo
TTY (a
new PTY is automatically allocated
)
2639 No device is allocated
.
2642 @item chardev
:@
var{id
}
2643 Use a named character device defined with the @code
{-chardev
} option
.
2645 [Linux only
] Use host tty
, e
.g
. @file
{/dev
/ttyS0
}. The host serial port
2646 parameters are set according to the emulated ones
.
2647 @item
/dev
/parport@
var{N
}
2648 [Linux only
, parallel port only
] Use host parallel port
2649 @
var{N
}. Currently SPP and EPP parallel port features can be used
.
2650 @item file
:@
var{filename
}
2651 Write output to @
var{filename
}. No character can be read
.
2653 [Unix only
] standard input
/output
2654 @item pipe
:@
var{filename
}
2655 name pipe @
var{filename
}
2657 [Windows only
] Use host serial port @
var{n
}
2658 @item udp
:[@
var{remote_host
}]:@
var{remote_port
}[@@
[@
var{src_ip
}]:@
var{src_port
}]
2659 This
implements UDP Net Console
.
2660 When @
var{remote_host
} or @
var{src_ip
} are not specified
2661 they
default to @code
{0.0.0.0}.
2662 When not
using a specified @
var{src_port
} a random port is automatically chosen
.
2664 If you just want a simple readonly console you can use @code
{netcat
} or
2665 @code
{nc
}, by starting QEMU with
: @code
{-serial udp
::4555} and nc as
:
2666 @code
{nc
-u
-l
-p
4555}. Any time QEMU writes something to that port it
2667 will appear
in the netconsole session
.
2669 If you plan to send characters back via netconsole or you want to stop
2670 and start QEMU a lot of times
, you should have QEMU use the same
2671 source port each time by
using something like @code
{-serial
2672 udp
::4555@@
:4556} to QEMU
. Another approach is to use a patched
2673 version of netcat which can listen to a TCP port and send and receive
2674 characters via udp
. If you have a patched version of netcat which
2675 activates telnet remote echo and single char transfer
, then you can
2676 use the following options to step up a netcat redirector to allow
2677 telnet on port
5555 to access the QEMU port
.
2680 -serial udp
::4555@@
:4556
2681 @item netcat options
:
2682 -u
-P
4555 -L
0.0.0.0:4556 -t
-p
5555 -I
-T
2683 @item telnet options
:
2687 @item tcp
:[@
var{host
}]:@
var{port
}[,@
var{server
}][,nowait
][,nodelay
]
2688 The TCP Net Console has two modes of operation
. It can send the serial
2689 I
/O to a location or wait
for a connection from a location
. By
default
2690 the TCP Net Console is sent to @
var{host
} at the @
var{port
}. If you use
2691 the @
var{server
} option QEMU will wait
for a client socket application
2692 to connect to the port before continuing
, unless the @code
{nowait
}
2693 option was specified
. The @code
{nodelay
} option disables the Nagle buffering
2694 algorithm
. If @
var{host
} is omitted
, 0.0.0.0 is assumed
. Only
2695 one TCP connection at a time is accepted
. You can use @code
{telnet
} to
2696 connect to the corresponding character device
.
2698 @item Example to send tcp console to
192.168.0.2 port
4444
2699 -serial tcp
:192.168.0.2:4444
2700 @item Example to listen and wait on port
4444 for connection
2701 -serial tcp
::4444,server
2702 @item Example to not wait and listen on ip
192.168.0.100 port
4444
2703 -serial tcp
:192.168.0.100:4444,server
,nowait
2706 @item telnet
:@
var{host
}:@
var{port
}[,server
][,nowait
][,nodelay
]
2707 The telnet protocol is used instead of raw tcp sockets
. The options
2708 work the same as
if you had specified @code
{-serial tcp
}. The
2709 difference is that the port acts like a telnet server or client
using
2710 telnet option negotiation
. This will also allow you to send the
2711 MAGIC_SYSRQ sequence
if you use a telnet that supports sending the
break
2712 sequence
. Typically
in unix telnet you
do it with Control
-] and then
2713 type
"send break" followed by pressing the enter key
.
2715 @item unix
:@
var{path
}[,server
][,nowait
]
2716 A unix domain socket is used instead of a tcp socket
. The option works the
2717 same as
if you had specified @code
{-serial tcp
} except the unix domain socket
2718 @
var{path
} is used
for connections
.
2720 @item mon
:@
var{dev_string
}
2721 This is a special option to allow the monitor to be multiplexed onto
2722 another serial port
. The monitor is accessed with key sequence of
2723 @key
{Control
-a
} and then pressing @key
{c
}.
2724 @
var{dev_string
} should be any one of the serial devices specified
2725 above
. An example to multiplex the monitor onto a telnet server
2726 listening on port
4444 would be
:
2728 @item
-serial mon
:telnet
::4444,server
,nowait
2730 When the monitor is multiplexed to stdio
in this way
, Ctrl
+C will not terminate
2731 QEMU any more but will be passed to the guest instead
.
2734 Braille device
. This will use BrlAPI to display the braille output on a real
2738 Three button serial mouse
. Configure the guest to use Microsoft protocol
.
2742 DEF("parallel", HAS_ARG
, QEMU_OPTION_parallel
, \
2743 "-parallel dev redirect the parallel port to char device 'dev'\n",
2746 @item
-parallel @
var{dev
}
2748 Redirect the virtual parallel port to host device @
var{dev
} (same
2749 devices as the serial port
). On Linux hosts
, @file
{/dev
/parportN
} can
2750 be used to use hardware devices connected on the corresponding host
2753 This option can be used several times to simulate up to
3 parallel
2756 Use @code
{-parallel none
} to disable all parallel ports
.
2759 DEF("monitor", HAS_ARG
, QEMU_OPTION_monitor
, \
2760 "-monitor dev redirect the monitor to char device 'dev'\n",
2763 @item
-monitor @
var{dev
}
2765 Redirect the monitor to host device @
var{dev
} (same devices as the
2767 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2769 Use @code
{-monitor none
} to disable the
default monitor
.
2771 DEF("qmp", HAS_ARG
, QEMU_OPTION_qmp
, \
2772 "-qmp dev like -monitor but opens in 'control' mode\n",
2775 @item
-qmp @
var{dev
}
2777 Like
-monitor but opens
in 'control' mode
.
2780 DEF("mon", HAS_ARG
, QEMU_OPTION_mon
, \
2781 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL
)
2783 @item
-mon
[chardev
=]name
[,mode
=readline|control
][,default]
2785 Setup monitor on chardev @
var{name
}.
2788 DEF("debugcon", HAS_ARG
, QEMU_OPTION_debugcon
, \
2789 "-debugcon dev redirect the debug console to char device 'dev'\n",
2792 @item
-debugcon @
var{dev
}
2794 Redirect the debug console to host device @
var{dev
} (same devices as the
2795 serial port
). The debug console is an I
/O port which is typically port
2796 0xe9; writing to that I
/O port sends output to
this device
.
2797 The
default device is @code
{vc
} in graphical mode and @code
{stdio
} in
2801 DEF("pidfile", HAS_ARG
, QEMU_OPTION_pidfile
, \
2802 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL
)
2804 @item
-pidfile @
var{file
}
2806 Store the QEMU process PID
in @
var{file
}. It is useful
if you launch QEMU
2810 DEF("singlestep", 0, QEMU_OPTION_singlestep
, \
2811 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL
)
2815 Run the emulation
in single step mode
.
2818 DEF("S", 0, QEMU_OPTION_S
, \
2819 "-S freeze CPU at startup (use 'c' to start execution)\n",
2824 Do not start CPU at
startup (you must type
'c' in the monitor
).
2827 DEF("realtime", HAS_ARG
, QEMU_OPTION_realtime
,
2828 "-realtime [mlock=on|off]\n"
2829 " run qemu with realtime features\n"
2830 " mlock=on|off controls mlock support (default: on)\n",
2833 @item
-realtime mlock
=on|off
2835 Run qemu with realtime features
.
2836 mlocking qemu and guest memory can be enabled via @option
{mlock
=on
}
2837 (enabled by
default).
2840 DEF("gdb", HAS_ARG
, QEMU_OPTION_gdb
, \
2841 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL
)
2843 @item
-gdb @
var{dev
}
2845 Wait
for gdb connection on device @
var{dev
} (@pxref
{gdb_usage
}). Typical
2846 connections will likely be TCP
-based
, but also UDP
, pseudo TTY
, or even
2847 stdio are reasonable use
case. The latter is allowing to start QEMU from
2848 within gdb and establish the connection via a pipe
:
2850 (gdb
) target remote | exec qemu
-system
-i386
-gdb stdio
...
2854 DEF("s", 0, QEMU_OPTION_s
, \
2855 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT
"\n",
2860 Shorthand
for -gdb tcp
::1234, i
.e
. open a gdbserver on TCP port
1234
2861 (@pxref
{gdb_usage
}).
2864 DEF("d", HAS_ARG
, QEMU_OPTION_d
, \
2865 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
2868 @item
-d @
var{item1
}[,...]
2870 Enable logging of specified items
. Use
'-d help' for a list of log items
.
2873 DEF("D", HAS_ARG
, QEMU_OPTION_D
, \
2874 "-D logfile output log to logfile (default stderr)\n",
2877 @item
-D @
var{logfile
}
2879 Output log
in @
var{logfile
} instead of to stderr
2882 DEF("L", HAS_ARG
, QEMU_OPTION_L
, \
2883 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2888 Set the directory
for the BIOS
, VGA BIOS and keymaps
.
2891 DEF("bios", HAS_ARG
, QEMU_OPTION_bios
, \
2892 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL
)
2894 @item
-bios @
var{file
}
2896 Set the filename
for the BIOS
.
2899 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm
, \
2900 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL
)
2904 Enable KVM full virtualization support
. This option is only available
2905 if KVM support is enabled when compiling
.
2908 DEF("xen-domid", HAS_ARG
, QEMU_OPTION_xen_domid
,
2909 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL
)
2910 DEF("xen-create", 0, QEMU_OPTION_xen_create
,
2911 "-xen-create create domain using xen hypercalls, bypassing xend\n"
2912 " warning: should not be used when xend is in use\n",
2914 DEF("xen-attach", 0, QEMU_OPTION_xen_attach
,
2915 "-xen-attach attach to existing xen domain\n"
2916 " xend will use this when starting QEMU\n",
2919 @item
-xen
-domid @
var{id
}
2921 Specify xen guest domain @
var{id
} (XEN only
).
2924 Create domain
using xen hypercalls
, bypassing xend
.
2925 Warning
: should not be used when xend is
in use (XEN only
).
2928 Attach to existing xen domain
.
2929 xend will use
this when starting
QEMU (XEN only
).
2932 DEF("no-reboot", 0, QEMU_OPTION_no_reboot
, \
2933 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL
)
2937 Exit instead of rebooting
.
2940 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown
, \
2941 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL
)
2944 @findex
-no
-shutdown
2945 Don
't exit QEMU on guest shutdown, but instead only stop the emulation.
2946 This allows for instance switching to monitor to commit changes to the
2950 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
2951 "-loadvm [tag|id]\n" \
2952 " start right away with a saved state (loadvm in monitor)\n",
2955 @item -loadvm @var{file}
2957 Start right away with a saved state (@code{loadvm} in monitor)
2961 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
2962 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
2967 Daemonize the QEMU process after initialization. QEMU will not detach from
2968 standard IO until it is ready to receive connections on any of its devices.
2969 This option is a useful way for external programs to launch QEMU without having
2970 to cope with initialization race conditions.
2973 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
2974 "-option-rom rom load a file, rom, into the option ROM space\n",
2977 @item -option-rom @var{file}
2979 Load the contents of @var{file} as an option ROM.
2980 This option is useful to load things like EtherBoot.
2983 DEF("clock", HAS_ARG, QEMU_OPTION_clock, \
2984 "-clock force the use of the given methods for timer alarm.\n" \
2985 " To see what timers are available use '-clock help
'\n",
2988 @item -clock @var{method}
2990 Force the use of the given methods for timer alarm. To see what timers
2991 are available use @code{-clock help}.
2994 HXCOMM Options deprecated by -rtc
2995 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
2996 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
2998 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
2999 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3000 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3005 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3007 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3008 UTC or local time, respectively. @code{localtime} is required for correct date in
3009 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3010 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3012 By default the RTC is driven by the host system time. This allows using of the
3013 RTC as accurate reference clock inside the guest, specifically if the host
3014 time is smoothly following an accurate external reference clock, e.g. via NTP.
3015 If you want to isolate the guest time from the host, you can set @option{clock}
3016 to @code{rt} instead. To even prevent it from progressing during suspension,
3017 you can set it to @code{vm}.
3019 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3020 specifically with Windows' ACPI HAL
. This option will
try to figure out how
3021 many timer interrupts were not processed by the Windows guest and will
3025 DEF("icount", HAS_ARG
, QEMU_OPTION_icount
, \
3026 "-icount [shift=N|auto][,align=on|off]\n" \
3027 " enable virtual instruction counter with 2^N clock ticks per\n" \
3028 " instruction and enable aligning the host and virtual clocks\n", QEMU_ARCH_ALL
)
3030 @item
-icount
[shift
=@
var{N
}|auto
]
3032 Enable virtual instruction counter
. The virtual cpu will execute one
3033 instruction every
2^@
var{N
} ns of virtual time
. If @code
{auto
} is specified
3034 then the virtual cpu speed will be automatically adjusted to keep virtual
3035 time within a few seconds of real time
.
3037 Note that
while this option can give deterministic behavior
, it does not
3038 provide cycle accurate emulation
. Modern CPUs contain superscalar out of
3039 order cores with complex cache hierarchies
. The number of instructions
3040 executed often has little or no correlation with actual performance
.
3042 @option
{align
=on
} will activate the delay algorithm which will
try to
3043 to synchronise the host clock and the virtual clock
. The goal is to
3044 have a guest running at the real frequency imposed by the shift option
.
3045 Whenever the guest clock is behind the host clock and
if
3046 @option
{align
=on
} is specified then we print a messsage to the user
3047 to inform about the delay
.
3048 Currently
this option does not work when @option
{shift
} is @code
{auto
}.
3049 Note
: The sync algorithm will work
for those shift values
for which
3050 the guest clock runs ahead of the host clock
. Typically
this happens
3051 when the shift value is
high (how high depends on the host machine
).
3054 DEF("watchdog", HAS_ARG
, QEMU_OPTION_watchdog
, \
3055 "-watchdog i6300esb|ib700\n" \
3056 " enable virtual hardware watchdog [default=none]\n",
3059 @item
-watchdog @
var{model
}
3061 Create a virtual hardware watchdog device
. Once
enabled (by a guest
3062 action
), the watchdog must be periodically polled by an agent inside
3063 the guest or
else the guest will be restarted
.
3065 The @
var{model
} is the model of hardware watchdog to emulate
. Choices
3066 for model are
: @code
{ib700
} (iBASE
700) which is a very simple ISA
3067 watchdog with a single timer
, or @code
{i6300esb
} (Intel
6300ESB I
/O
3068 controller hub
) which is a much more featureful PCI
-based dual
-timer
3069 watchdog
. Choose a model
for which your guest has drivers
.
3071 Use @code
{-watchdog help
} to list available hardware models
. Only one
3072 watchdog can be enabled
for a guest
.
3075 DEF("watchdog-action", HAS_ARG
, QEMU_OPTION_watchdog_action
, \
3076 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3077 " action when watchdog fires [default=reset]\n",
3080 @item
-watchdog
-action @
var{action
}
3081 @findex
-watchdog
-action
3083 The @
var{action
} controls what QEMU will
do when the watchdog timer
3086 @code
{reset
} (forcefully reset the guest
).
3087 Other possible actions are
:
3088 @code
{shutdown
} (attempt to gracefully shutdown the guest
),
3089 @code
{poweroff
} (forcefully poweroff the guest
),
3090 @code
{pause
} (pause the guest
),
3091 @code
{debug
} (print a debug message and
continue), or
3092 @code
{none
} (do nothing
).
3094 Note that the @code
{shutdown
} action requires that the guest responds
3095 to ACPI signals
, which it may not be able to
do in the sort of
3096 situations where the watchdog would have expired
, and thus
3097 @code
{-watchdog
-action shutdown
} is not recommended
for production use
.
3102 @item
-watchdog i6300esb
-watchdog
-action pause
3103 @item
-watchdog ib700
3107 DEF("echr", HAS_ARG
, QEMU_OPTION_echr
, \
3108 "-echr chr set terminal escape character instead of ctrl-a\n",
3112 @item
-echr @
var{numeric_ascii_value
}
3114 Change the escape character used
for switching to the monitor when
using
3115 monitor and serial sharing
. The
default is @code
{0x01} when
using the
3116 @code
{-nographic
} option
. @code
{0x01} is equal to pressing
3117 @code
{Control
-a
}. You can select a different character from the ascii
3118 control keys where
1 through
26 map to Control
-a through Control
-z
. For
3119 instance you could use the either of the following to change the escape
3120 character to Control
-t
.
3127 DEF("virtioconsole", HAS_ARG
, QEMU_OPTION_virtiocon
, \
3128 "-virtioconsole c\n" \
3129 " set virtio console\n", QEMU_ARCH_ALL
)
3131 @item
-virtioconsole @
var{c
}
3132 @findex
-virtioconsole
3135 This option is maintained
for backward compatibility
.
3137 Please use @code
{-device virtconsole
} for the
new way of invocation
.
3140 DEF("show-cursor", 0, QEMU_OPTION_show_cursor
, \
3141 "-show-cursor show cursor\n", QEMU_ARCH_ALL
)
3144 @findex
-show
-cursor
3148 DEF("tb-size", HAS_ARG
, QEMU_OPTION_tb_size
, \
3149 "-tb-size n set TB size\n", QEMU_ARCH_ALL
)
3151 @item
-tb
-size @
var{n
}
3156 DEF("incoming", HAS_ARG
, QEMU_OPTION_incoming
, \
3157 "-incoming p prepare for incoming migration, listen on port p\n",
3160 @item
-incoming @
var{port
}
3162 Prepare
for incoming migration
, listen on @
var{port
}.
3165 DEF("nodefaults", 0, QEMU_OPTION_nodefaults
, \
3166 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL
)
3170 Don
't create default devices. Normally, QEMU sets the default devices like serial
3171 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3172 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3177 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3178 "-chroot dir chroot to dir just before starting the VM\n",
3182 @item -chroot @var{dir}
3184 Immediately before starting guest execution, chroot to the specified
3185 directory. Especially useful in combination with -runas.
3189 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3190 "-runas user change to user id user just before starting the VM\n",
3194 @item -runas @var{user}
3196 Immediately before starting guest execution, drop root privileges, switching
3197 to the specified user.
3200 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3201 "-prom-env variable=value\n"
3202 " set OpenBIOS nvram variables\n",
3203 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3205 @item -prom-env @var{variable}=@var{value}
3207 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3209 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3210 "-semihosting semihosting mode\n",
3211 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32)
3214 @findex -semihosting
3215 Semihosting mode (ARM, M68K, Xtensa only).
3217 DEF("old-param", 0, QEMU_OPTION_old_param,
3218 "-old-param old param mode\n", QEMU_ARCH_ARM)
3221 @findex -old-param (ARM)
3222 Old param mode (ARM only).
3225 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3226 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off
').\n",
3229 @item -sandbox @var{arg}
3231 Enable Seccomp mode 2 system call filter. 'on
' will enable syscall filtering and 'off
' will
3232 disable it. The default is 'off
'.
3235 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3236 "-readconfig <file>\n", QEMU_ARCH_ALL)
3238 @item -readconfig @var{file}
3240 Read device configuration from @var{file}. This approach is useful when you want to spawn
3241 QEMU process with many command line options but you don't want to exceed the command line
3244 DEF("writeconfig", HAS_ARG
, QEMU_OPTION_writeconfig
,
3245 "-writeconfig <file>\n"
3246 " read/write config file\n", QEMU_ARCH_ALL
)
3248 @item
-writeconfig @
var{file
}
3249 @findex
-writeconfig
3250 Write device configuration to @
var{file
}. The @
var{file
} can be either filename to save
3251 command line and device configuration into file or dash @code
{-}) character to print the
3252 output to stdout
. This can be later used as input file
for @code
{-readconfig
} option
.
3254 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig
,
3256 " do not load default config files at startup\n",
3260 @findex
-nodefconfig
3261 Normally QEMU loads configuration files from @
var{sysconfdir
} and @
var{datadir
} at startup
.
3262 The @code
{-nodefconfig
} option will prevent QEMU from loading any of those config files
.
3264 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig
,
3266 " do not load user-provided config files at startup\n",
3269 @item
-no
-user
-config
3270 @findex
-no
-user
-config
3271 The @code
{-no
-user
-config
} option makes QEMU not load any of the user
-provided
3272 config files on @
var{sysconfdir
}, but won
't make it skip the QEMU-provided config
3273 files from @var{datadir}.
3275 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3276 "-trace [events=<file>][,file=<file>]\n"
3277 " specify tracing options\n",
3280 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3281 HXCOMM HX does not support conditional compilation of text.
3282 @item -trace [events=@var{file}][,file=@var{file}]
3285 Specify tracing options.
3288 @item events=@var{file}
3289 Immediately enable events listed in @var{file}.
3290 The file must contain one event name (as listed in the @var{trace-events} file)
3292 This option is only available if QEMU has been compiled with
3293 either @var{simple} or @var{stderr} tracing backend.
3294 @item file=@var{file}
3295 Log output traces to @var{file}.
3297 This option is only available if QEMU has been compiled with
3298 the @var{simple} tracing backend.
3303 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3304 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3307 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3308 "-enable-fips enable FIPS 140-2 compliance\n",
3313 @findex -enable-fips
3314 Enable FIPS 140-2 compliance mode.
3317 HXCOMM Deprecated by -machine accel=tcg property
3318 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3320 HXCOMM Deprecated by kvm-pit driver properties
3321 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3324 HXCOMM Deprecated (ignored)
3325 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
3327 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3328 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3330 HXCOMM Deprecated (ignored)
3331 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3333 DEF("object", HAS_ARG, QEMU_OPTION_object,
3334 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3335 " create an new object of type TYPENAME setting properties\n"
3336 " in the order they are specified. Note that the 'id
'\n"
3337 " property must be set. These objects are placed in the\n"
3338 " '/objects
' path.\n",
3341 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3343 Create an new object of type @var{typename} setting properties
3344 in the order they are specified. Note that the 'id
'
3345 property must be set. These objects are placed in the
3349 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3350 "-msg timestamp[=on|off]\n"
3351 " change the format of messages\n"
3352 " on|off controls leading timestamps (default:on)\n",
3355 @item -msg timestamp[=on|off]
3357 prepend a timestamp to each log message.(default:on)
3360 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3361 "-dump-vmstate <file>\n"
3362 " Output vmstate information in JSON format to file.\n"
3363 " Use the scripts/vmstate-static-checker.py file to\n"
3364 " check for possible regressions in migration code\n"
3365 " by comparing two such vmstate dumps.",
3368 @item -dump-vmstate @var{file}
3369 @findex -dump-vmstate
3370 Dump json-encoded vmstate information for current machine type to file
3374 HXCOMM This is the last statement. Insert new options before this line!