1 HXCOMM Use
DEFHEADING() to define headings
in both help text and texi
2 HXCOMM Text between STEXI and ETEXI are copied to texi version and
3 HXCOMM discarded from C version
4 HXCOMM
DEF(option
, HAS_ARG
/0, opt_enum
, opt_help
, arch_mask
) is used to
5 HXCOMM construct option structures
, enums and help message
for specified
7 HXCOMM HXCOMM can be used
for comments
, discarded from both texi and C
9 DEFHEADING(Standard options
:)
14 DEF("help", 0, QEMU_OPTION_h
,
15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL
)
22 DEF("version", 0, QEMU_OPTION_version
,
23 "-version display version information and exit\n", QEMU_ARCH_ALL
)
27 Display version information and exit
30 DEF("machine", HAS_ARG
, QEMU_OPTION_machine
, \
31 "-machine [type=]name[,prop[=value][,...]]\n"
32 " selects emulated machine ('-machine help' for list)\n"
33 " property accel=accel1[:accel2[:...]] selects accelerator\n"
34 " supported accelerators are kvm, xen, tcg (default: tcg)\n"
35 " kernel_irqchip=on|off controls accelerated irqchip support\n"
36 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n"
37 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
38 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n"
39 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
40 " mem-merge=on|off controls memory merge support (default: on)\n"
41 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
42 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
43 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
44 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
45 " nvdimm=on|off controls NVDIMM support (default=off)\n"
46 " enforce-config-section=on|off enforce configuration section migration (default=off)\n",
49 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
51 Select the emulated machine by @
var{name
}. Use @code
{-machine help
} to list
52 available machines
. Supported machine properties are
:
54 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
55 This is used to enable an accelerator
. Depending on the target architecture
,
56 kvm
, xen
, or tcg can be available
. By
default, tcg is used
. If there is more
57 than one accelerator specified
, the next one is used
if the previous one fails
59 @item kernel_irqchip
=on|off
60 Controls
in-kernel irqchip support
for the chosen accelerator when available
.
61 @item gfx_passthru
=on|off
62 Enables IGD GFX passthrough support
for the chosen machine when available
.
63 @item vmport
=on|off|auto
64 Enables emulation of VMWare IO port
, for vmmouse etc
. auto says to select the
65 value based on accel
. For accel
=xen the
default is off otherwise the
default
67 @item kvm_shadow_mem
=size
68 Defines the size of the KVM shadow MMU
.
69 @item dump
-guest
-core
=on|off
70 Include guest memory
in a core dump
. The
default is on
.
71 @item mem
-merge
=on|off
72 Enables or disables memory merge support
. This feature
, when supported by
73 the host
, de
-duplicates identical memory pages among VMs instances
75 @item aes
-key
-wrap
=on|off
76 Enables or disables AES key wrapping support on s390
-ccw hosts
. This feature
77 controls whether AES wrapping keys will be created to allow
78 execution of AES cryptographic functions
. The
default is on
.
79 @item dea
-key
-wrap
=on|off
80 Enables or disables DEA key wrapping support on s390
-ccw hosts
. This feature
81 controls whether DEA wrapping keys will be created to allow
82 execution of DEA cryptographic functions
. The
default is on
.
84 Enables or disables NVDIMM support
. The
default is off
.
88 HXCOMM Deprecated by
-machine
89 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
91 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
92 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
94 @item
-cpu @
var{model
}
96 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
99 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
100 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
101 " set the number of CPUs to 'n' [default=1]\n"
102 " maxcpus= maximum number of total cpus, including\n"
103 " offline CPUs for hotplug, etc\n"
104 " cores= number of CPU cores on one socket\n"
105 " threads= number of threads on one CPU core\n"
106 " sockets= number of discrete sockets in the system\n",
109 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
111 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
112 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
114 For the PC target
, the number of @
var{cores
} per socket
, the number
115 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
116 specified
. Missing values will be computed
. If any on the three values is
117 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
118 specifies the maximum number of hotpluggable CPUs
.
121 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
122 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n"
123 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL
)
125 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
126 @itemx
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
128 Simulate a multi node NUMA system
. If @samp
{mem
}, @samp
{memdev
}
129 and @samp
{cpus
} are omitted
, resources are split equally
. Also
, note
130 that the
-@option
{numa
} option doesn
't allocate any of the specified
131 resources. That is, it just assigns existing resources to NUMA nodes. This
132 means that one still has to use the @option{-m}, @option{-smp} options
133 to allocate RAM and VCPUs respectively, and possibly @option{-object}
134 to specify the memory backend for the @samp{memdev} suboption.
136 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
137 node uses @samp{memdev}, all of them have to use it.
140 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
141 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
142 " Add 'fd
' to fd 'set
'\n", QEMU_ARCH_ALL)
144 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
147 Add a file descriptor to an fd set. Valid options are:
151 This option defines the file descriptor of which a duplicate is added to fd set.
152 The file descriptor cannot be stdin, stdout, or stderr.
154 This option defines the ID of the fd set to add the file descriptor to.
155 @item opaque=@var{opaque}
156 This option defines a free-form string that can be used to describe @var{fd}.
159 You can open an image using pre-opened file descriptors from an fd set:
162 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
163 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
164 -drive file=/dev/fdset/2,index=0,media=disk
168 DEF("set", HAS_ARG, QEMU_OPTION_set,
169 "-set group.id.arg=value\n"
170 " set <arg> parameter for item <id> of type <group>\n"
171 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
173 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
175 Set parameter @var{arg} for item @var{id} of type @var{group}\n"
178 DEF("global", HAS_ARG, QEMU_OPTION_global,
179 "-global driver.property=value\n"
180 "-global driver=driver,property=property,value=value\n"
181 " set a global default for a driver property\n",
184 @item -global @var{driver}.@var{prop}=@var{value}
185 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
187 Set default value of @var{driver}'s property @
var{prop
} to @
var{value
}, e
.g
.:
190 qemu
-system
-i386
-global ide
-drive
.physical_block_size
=4096 -drive file
=file
,if=ide
,index
=0,media
=disk
193 In particular
, you can use
this to set driver properties
for devices which are
194 created automatically by the machine model
. To create a device which is not
195 created automatically and set properties on it
, use
-@option
{device
}.
197 -global @
var{driver
}.@
var{prop
}=@
var{value
} is shorthand
for -global
198 driver
=@
var{driver
},property
=@
var{prop
},value
=@
var{value
}. The
199 longhand syntax works even when @
var{driver
} contains a dot
.
202 DEF("boot", HAS_ARG
, QEMU_OPTION_boot
,
203 "-boot [order=drives][,once=drives][,menu=on|off]\n"
204 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
205 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
206 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
207 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
208 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
211 @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
]
213 Specify boot order @
var{drives
} as a string of drive letters
. Valid
214 drive letters depend on the target architecture
. The x86 PC uses
: a
, b
215 (floppy
1 and
2), c (first hard disk
), d (first CD
-ROM
), n
-p (Etherboot
216 from network adapter
1-4), hard disk boot is the
default. To apply a
217 particular boot order only on the first startup
, specify it via
220 Interactive boot menus
/prompts can be enabled via @option
{menu
=on
} as far
221 as firmware
/BIOS supports them
. The
default is non
-interactive boot
.
223 A splash picture could be passed to bios
, enabling user to show it as logo
,
224 when option splash
=@
var{sp_name
} is given and menu
=on
, If firmware
/BIOS
225 supports them
. Currently Seabios
for X86 system support it
.
226 limitation
: The splash file could be a jpeg file or a BMP file
in 24 BPP
227 format(true color
). The resolution should be supported by the SVGA mode
, so
228 the recommended is
320x240
, 640x480
, 800x640
.
230 A timeout could be passed to bios
, guest will pause
for @
var{rb_timeout
} ms
231 when boot failed
, then reboot
. If @
var{rb_timeout
} is
'-1', guest will not
232 reboot
, qemu passes
'-1' to bios by
default. Currently Seabios
for X86
235 Do strict boot via @option
{strict
=on
} as far as firmware
/BIOS
236 supports it
. This only effects when boot priority is changed by
237 bootindex options
. The
default is non
-strict boot
.
240 #
try to boot from network first
, then from hard disk
241 qemu
-system
-i386
-boot order
=nc
242 # boot from CD
-ROM first
, switch back to
default order after reboot
243 qemu
-system
-i386
-boot once
=d
244 # boot with a splash picture
for 5 seconds
.
245 qemu
-system
-i386
-boot menu
=on
,splash
=/root
/boot
.bmp
,splash
-time
=5000
248 Note
: The legacy format
'-boot @var{drives}' is still supported but its
249 use is discouraged as it may be removed from future versions
.
252 DEF("m", HAS_ARG
, QEMU_OPTION_m
,
253 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
254 " configure guest RAM\n"
255 " size: initial amount of guest memory\n"
256 " slots: number of hotplug slots (default: none)\n"
257 " maxmem: maximum amount of guest memory (default: none)\n"
258 "NOTE: Some architectures might enforce a specific granularity\n",
261 @item
-m
[size
=]@
var{megs
}[,slots
=n
,maxmem
=size
]
263 Sets guest startup RAM size to @
var{megs
} megabytes
. Default is
128 MiB
.
264 Optionally
, a suffix of ``M
'' or ``G
'' can be used to signify a value
in
265 megabytes or gigabytes respectively
. Optional pair @
var{slots
}, @
var{maxmem
}
266 could be used to set amount of hotpluggable memory slots and maximum amount of
267 memory
. Note that @
var{maxmem
} must be aligned to the page size
.
269 For example
, the following command
-line sets the guest startup RAM size to
270 1GB
, creates
3 slots to hotplug additional memory and sets the maximum
271 memory the guest can reach to
4GB
:
274 qemu
-system
-x86_64
-m
1G
,slots
=3,maxmem
=4G
277 If @
var{slots
} and @
var{maxmem
} are not specified
, memory hotplug won
't
278 be enabled and the guest startup RAM will never increase.
281 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
282 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
284 @item -mem-path @var{path}
286 Allocate guest RAM from a temporarily created file in @var{path}.
289 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
290 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
294 @findex -mem-prealloc
295 Preallocate memory when using -mem-path.
298 DEF("k", HAS_ARG, QEMU_OPTION_k,
299 "-k language use keyboard layout (for example 'fr
' for French)\n",
302 @item -k @var{language}
304 Use keyboard layout @var{language} (for example @code{fr} for
305 French). This option is only needed where it is not easy to get raw PC
306 keycodes (e.g. on Macs, with some X11 servers or with a VNC
307 display). You don't normally need to use it on PC
/Linux or PC
/Windows
310 The available layouts are
:
312 ar de
-ch es fo fr
-ca hu ja mk no pt
-br sv
313 da en
-gb et fr fr
-ch is lt nl pl ru th
314 de en
-us fi fr
-be hr it lv nl
-be pt sl tr
317 The
default is @code
{en
-us
}.
321 DEF("audio-help", 0, QEMU_OPTION_audio_help
,
322 "-audio-help print list of audio drivers and their options\n",
327 Will show the audio subsystem help
: list of drivers
, tunable
331 DEF("soundhw", HAS_ARG
, QEMU_OPTION_soundhw
,
332 "-soundhw c1,... enable audio support\n"
333 " and only specified sound cards (comma separated list)\n"
334 " use '-soundhw help' to get the list of supported cards\n"
335 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL
)
337 @item
-soundhw @
var{card1
}[,@
var{card2
},...] or
-soundhw all
339 Enable audio and selected sound hardware
. Use
'help' to print all
340 available sound hardware
.
343 qemu
-system
-i386
-soundhw sb16
,adlib disk
.img
344 qemu
-system
-i386
-soundhw es1370 disk
.img
345 qemu
-system
-i386
-soundhw ac97 disk
.img
346 qemu
-system
-i386
-soundhw hda disk
.img
347 qemu
-system
-i386
-soundhw all disk
.img
348 qemu
-system
-i386
-soundhw help
351 Note that Linux
's i810_audio OSS kernel (for AC97) module might
352 require manually specifying clocking.
355 modprobe i810_audio clocking=48000
359 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
360 "-balloon none disable balloon device\n"
361 "-balloon virtio[,addr=str]\n"
362 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
366 Disable balloon device.
367 @item -balloon virtio[,addr=@var{addr}]
368 Enable virtio balloon device (default), optionally with PCI address
372 DEF("device", HAS_ARG, QEMU_OPTION_device,
373 "-device driver[,prop[=value][,...]]\n"
374 " add device (based on driver)\n"
375 " prop=value,... sets driver properties\n"
376 " use '-device help
' to print all possible drivers\n"
377 " use '-device driver
,help
' to print all possible properties\n",
380 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
382 Add device @var{driver}. @var{prop}=@var{value} sets driver
383 properties. Valid properties depend on the driver. To get help on
384 possible drivers and properties, use @code{-device help} and
385 @code{-device @var{driver},help}.
388 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}]
390 Add an IPMI BMC. This is a simulation of a hardware management
391 interface processor that normally sits on a system. It provides
392 a watchdog and the ability to reset and power control the system.
393 You need to connect this to an IPMI interface to make it useful
395 The IPMI slave address to use for the BMC. The default is 0x20.
396 This address is the BMC's address on the I2C network of management
397 controllers
. If you don
't know what this means, it is safe to ignore
400 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
402 Add a connection to an external IPMI BMC simulator. Instead of
403 locally emulating the BMC like the above item, instead connect
404 to an external entity that provides the IPMI services.
406 A connection is made to an external BMC simulator. If you do this, it
407 is strongly recommended that you use the "reconnect=" chardev option
408 to reconnect to the simulator if the connection is lost. Note that if
409 this is not used carefully, it can be a security issue, as the
410 interface has the ability to send resets, NMIs, and power off the VM.
411 It's best
if QEMU makes a connection to an external simulator running
412 on a secure port on localhost
, so neither the simulator nor QEMU is
413 exposed to any outside network
.
415 See the
"lanserv/README.vm" file
in the OpenIPMI library
for more
416 details on the external
interface.
418 @item
-device isa
-ipmi
-kcs
,bmc
=@
var{id
}[,ioport
=@
var{val
}][,irq
=@
var{val
}]
420 Add a KCS IPMI interafce on the ISA bus
. This also adds a
421 corresponding ACPI and SMBIOS entries
, if appropriate
.
425 The BMC to connect to
, one of ipmi
-bmc
-sim or ipmi
-bmc
-extern above
.
426 @item ioport
=@
var{val
}
427 Define the I
/O address of the
interface. The
default is
0xca0 for KCS
.
429 Define the interrupt to use
. The
default is
5. To disable interrupts
,
433 @item
-device isa
-ipmi
-bt
,bmc
=@
var{id
}[,ioport
=@
var{val
}][,irq
=@
var{val
}]
435 Like the KCS
interface, but defines a BT
interface. The
default port is
436 0xe4 and the
default interrupt is
5.
440 DEF("name", HAS_ARG
, QEMU_OPTION_name
,
441 "-name string1[,process=string2][,debug-threads=on|off]\n"
442 " set the name of the guest\n"
443 " string1 sets the window title and string2 the process name (on Linux)\n"
444 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
445 " NOTE: The thread names are for debugging and not a stable API.\n",
448 @item
-name @
var{name
}
450 Sets the @
var{name
} of the guest
.
451 This name will be displayed
in the SDL window caption
.
452 The @
var{name
} will also be used
for the VNC server
.
453 Also optionally set the top visible process name
in Linux
.
454 Naming of individual threads can also be enabled on Linux to aid debugging
.
457 DEF("uuid", HAS_ARG
, QEMU_OPTION_uuid
,
458 "-uuid %08x-%04x-%04x-%04x-%012x\n"
459 " specify machine UUID\n", QEMU_ARCH_ALL
)
461 @item
-uuid @
var{uuid
}
471 DEFHEADING(Block device options
:)
476 DEF("fda", HAS_ARG
, QEMU_OPTION_fda
,
477 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL
)
478 DEF("fdb", HAS_ARG
, QEMU_OPTION_fdb
, "", QEMU_ARCH_ALL
)
480 @item
-fda @
var{file
}
481 @itemx
-fdb @
var{file
}
484 Use @
var{file
} as floppy disk
0/1 image (@pxref
{disk_images
}).
487 DEF("hda", HAS_ARG
, QEMU_OPTION_hda
,
488 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL
)
489 DEF("hdb", HAS_ARG
, QEMU_OPTION_hdb
, "", QEMU_ARCH_ALL
)
490 DEF("hdc", HAS_ARG
, QEMU_OPTION_hdc
,
491 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL
)
492 DEF("hdd", HAS_ARG
, QEMU_OPTION_hdd
, "", QEMU_ARCH_ALL
)
494 @item
-hda @
var{file
}
495 @itemx
-hdb @
var{file
}
496 @itemx
-hdc @
var{file
}
497 @itemx
-hdd @
var{file
}
502 Use @
var{file
} as hard disk
0, 1, 2 or
3 image (@pxref
{disk_images
}).
505 DEF("cdrom", HAS_ARG
, QEMU_OPTION_cdrom
,
506 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
509 @item
-cdrom @
var{file
}
511 Use @
var{file
} as CD
-ROM
image (you cannot use @option
{-hdc
} and
512 @option
{-cdrom
} at the same time
). You can use the host CD
-ROM by
513 using @file
{/dev
/cdrom
} as
filename (@pxref
{host_drives
}).
516 DEF("drive", HAS_ARG
, QEMU_OPTION_drive
,
517 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
518 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
519 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
520 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
521 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
522 " [,readonly=on|off][,copy-on-read=on|off]\n"
523 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
524 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
525 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
526 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
527 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
528 " [[,iops_size=is]]\n"
530 " use 'file' as a drive image\n", QEMU_ARCH_ALL
)
532 @item
-drive @
var{option
}[,@
var{option
}[,@
var{option
}[,...]]]
535 Define a
new drive
. Valid options are
:
538 @item file
=@
var{file
}
539 This option defines which disk
image (@pxref
{disk_images
}) to use with
540 this drive
. If the filename contains comma
, you must double it
541 (for instance
, "file=my,,file" to use file
"my,file").
543 Special files such as iSCSI devices can be specified
using protocol
544 specific URLs
. See the section
for "Device URL Syntax" for more information
.
545 @item
if=@
var{interface}
546 This option defines on which type on
interface the drive is connected
.
547 Available types are
: ide
, scsi
, sd
, mtd
, floppy
, pflash
, virtio
.
548 @item bus
=@
var{bus
},unit
=@
var{unit
}
549 These options define where is connected the drive by defining the bus number and
551 @item index
=@
var{index
}
552 This option defines where is connected the drive by
using an index
in the list
553 of available connectors of a given
interface type
.
554 @item media
=@
var{media
}
555 This option defines the type of the media
: disk or cdrom
.
556 @item cyls
=@
var{c
},heads
=@
var{h
},secs
=@
var{s
}[,trans
=@
var{t
}]
557 These options have the same definition as they have
in @option
{-hdachs
}.
558 @item snapshot
=@
var{snapshot
}
559 @
var{snapshot
} is
"on" or
"off" and controls snapshot mode
for the given drive
560 (see @option
{-snapshot
}).
561 @item cache
=@
var{cache
}
562 @
var{cache
} is
"none", "writeback", "unsafe", "directsync" or
"writethrough" and controls how the host cache is used to access block data
.
564 @
var{aio
} is
"threads", or
"native" and selects between pthread based disk I
/O and native Linux AIO
.
565 @item discard
=@
var{discard
}
566 @
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
.
567 @item format
=@
var{format
}
568 Specify which disk @
var{format
} will be used rather than detecting
569 the format
. Can be used to specify format
=raw to avoid interpreting
570 an untrusted format header
.
571 @item serial
=@
var{serial
}
572 This option specifies the serial number to assign to the device
.
573 @item addr
=@
var{addr
}
574 Specify the controller
's PCI address (if=virtio only).
575 @item werror=@var{action},rerror=@var{action}
576 Specify which @var{action} to take on write and read errors. Valid actions are:
577 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
578 "report" (report the error to the guest), "enospc" (pause QEMU only if the
579 host disk is full; report the error to the guest otherwise).
580 The default setting is @option{werror=enospc} and @option{rerror=report}.
582 Open drive @option{file} as read-only. Guest write attempts will fail.
583 @item copy-on-read=@var{copy-on-read}
584 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
585 file sectors into the image file.
586 @item detect-zeroes=@var{detect-zeroes}
587 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
588 conversion of plain zero writes by the OS to driver specific optimized
589 zero write commands. You may even choose "unmap" if @var{discard} is set
590 to "unmap" to allow a zero write to be converted to an UNMAP operation.
593 By default, the @option{cache=writeback} mode is used. It will report data
594 writes as completed as soon as the data is present in the host page cache.
595 This is safe as long as your guest OS makes sure to correctly flush disk caches
596 where needed. If your guest OS does not handle volatile disk write caches
597 correctly and your host crashes or loses power, then the guest may experience
600 For such guests, you should consider using @option{cache=writethrough}. This
601 means that the host page cache will be used to read and write data, but write
602 notification will be sent to the guest only after QEMU has made sure to flush
603 each write to the disk. Be aware that this has a major impact on performance.
605 The host page cache can be avoided entirely with @option{cache=none}. This will
606 attempt to do disk IO directly to the guest's memory
. QEMU may still perform
607 an internal copy of the data
. Note that
this is considered a writeback mode and
608 the guest OS must handle the disk write cache correctly
in order to avoid data
609 corruption on host crashes
.
611 The host page cache can be avoided
while only sending write notifications to
612 the guest when the data has been flushed to the disk
using
613 @option
{cache
=directsync
}.
615 In
case you don
't care about data integrity over host failures, use
616 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
617 data to the disk but can instead keep things in cache. If anything goes wrong,
618 like your host losing power, the disk storage getting disconnected accidentally,
619 etc. your image will most probably be rendered unusable. When using
620 the @option{-snapshot} option, unsafe caching is always used.
622 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
623 useful when the backing file is over a slow network. By default copy-on-read
626 Instead of @option{-cdrom} you can use:
628 qemu-system-i386 -drive file=file,index=2,media=cdrom
631 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
634 qemu-system-i386 -drive file=file,index=0,media=disk
635 qemu-system-i386 -drive file=file,index=1,media=disk
636 qemu-system-i386 -drive file=file,index=2,media=disk
637 qemu-system-i386 -drive file=file,index=3,media=disk
640 You can open an image using pre-opened file descriptors from an fd set:
643 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
644 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
645 -drive file=/dev/fdset/2,index=0,media=disk
648 You can connect a CDROM to the slave of ide0:
650 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
653 If you don't specify the
"file=" argument
, you define an empty drive
:
655 qemu
-system
-i386
-drive
if=ide
,index
=1,media
=cdrom
658 You can connect a SCSI disk with unit ID
6 on the bus #
0:
660 qemu
-system
-i386
-drive file
=file
,if=scsi
,bus
=0,unit
=6
663 Instead of @option
{-fda
}, @option
{-fdb
}, you can use
:
665 qemu
-system
-i386
-drive file
=file
,index
=0,if=floppy
666 qemu
-system
-i386
-drive file
=file
,index
=1,if=floppy
669 By
default, @
var{interface} is
"ide" and @
var{index
} is automatically
672 qemu
-system
-i386
-drive file
=a
-drive file
=b
"
676 qemu-system-i386 -hda a -hdb b
680 DEF("mtdblock
", HAS_ARG, QEMU_OPTION_mtdblock,
681 "-mtdblock file use
'file' as on
-board Flash memory image
\n",
684 @item -mtdblock @var{file}
686 Use @var{file} as on-board Flash memory image.
689 DEF("sd
", HAS_ARG, QEMU_OPTION_sd,
690 "-sd file use
'file' as SecureDigital card image
\n", QEMU_ARCH_ALL)
694 Use @var{file} as SecureDigital card image.
697 DEF("pflash
", HAS_ARG, QEMU_OPTION_pflash,
698 "-pflash file use
'file' as a parallel flash image
\n", QEMU_ARCH_ALL)
700 @item -pflash @var{file}
702 Use @var{file} as a parallel flash image.
705 DEF("snapshot
", 0, QEMU_OPTION_snapshot,
706 "-snapshot write to temporary files instead of disk image files
\n",
711 Write to temporary files instead of disk image files. In this case,
712 the raw disk image you use is not written back. You can however force
713 the write back by pressing @key{C-a s} (@pxref{disk_images}).
716 DEF("hdachs
", HAS_ARG, QEMU_OPTION_hdachs, \
717 "-hdachs c
,h
,s
[,t
]\n" \
718 " force hard disk
0 physical geometry and the optional BIOS
\n" \
719 " translation (t
=none or lba
) (usually QEMU can guess them
)\n",
722 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
724 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
725 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
726 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
727 all those parameters. This option is useful for old MS-DOS disk
731 DEF("fsdev
", HAS_ARG, QEMU_OPTION_fsdev,
732 "-fsdev fsdriver
,id
=id
[,path
=path
,][security_model
={mapped
-xattr|mapped
-file|passthrough|none
}]\n"
733 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
738 @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}]
740 Define a new file system device. Valid options are:
743 This option specifies the fs driver backend to use.
744 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
746 Specifies identifier for this device
747 @item path=@var{path}
748 Specifies the export path for the file system device. Files under
749 this path will be available to the 9p client on the guest.
750 @item security_model=@var{security_model}
751 Specifies the security model to be used for this export path.
752 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
753 In "passthrough
" security model, files are stored using the same
754 credentials as they are created on the guest. This requires QEMU
755 to run as root. In "mapped
-xattr
" security model, some of the file
756 attributes like uid, gid, mode bits and link target are stored as
757 file attributes. For "mapped
-file
" these attributes are stored in the
758 hidden .virtfs_metadata directory. Directories exported by this security model cannot
759 interact with other unix tools. "none
" security model is same as
760 passthrough except the sever won't report failures if it fails to
761 set file attributes like ownership. Security model is mandatory
762 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
763 security model as a parameter.
764 @item writeout=@var{writeout}
765 This is an optional argument. The only supported value is "immediate
".
766 This means that host page cache will be used to read and write data but
767 write notification will be sent to the guest only when the data has been
768 reported as written by the storage subsystem.
770 Enables exporting 9p share as a readonly mount for guests. By default
771 read-write access is given.
772 @item socket=@var{socket}
773 Enables proxy filesystem driver to use passed socket file for communicating
774 with virtfs-proxy-helper
775 @item sock_fd=@var{sock_fd}
776 Enables proxy filesystem driver to use passed socket descriptor for
777 communicating with virtfs-proxy-helper. Usually a helper like libvirt
778 will create socketpair and pass one of the fds as sock_fd
781 -fsdev option is used along with -device driver "virtio
-9p
-pci
".
782 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
783 Options for virtio-9p-pci driver are:
786 Specifies the id value specified along with -fsdev option
787 @item mount_tag=@var{mount_tag}
788 Specifies the tag name to be used by the guest to mount this export point
793 DEF("virtfs
", HAS_ARG, QEMU_OPTION_virtfs,
794 "-virtfs local
,path
=path
,mount_tag
=tag
,security_model
=[mapped
-xattr|mapped
-file|passthrough|none
]\n"
795 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
800 @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}]
803 The general form of a Virtual File system pass-through options are:
806 This option specifies the fs driver backend to use.
807 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
809 Specifies identifier for this device
810 @item path=@var{path}
811 Specifies the export path for the file system device. Files under
812 this path will be available to the 9p client on the guest.
813 @item security_model=@var{security_model}
814 Specifies the security model to be used for this export path.
815 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
816 In "passthrough
" security model, files are stored using the same
817 credentials as they are created on the guest. This requires QEMU
818 to run as root. In "mapped
-xattr
" security model, some of the file
819 attributes like uid, gid, mode bits and link target are stored as
820 file attributes. For "mapped
-file
" these attributes are stored in the
821 hidden .virtfs_metadata directory. Directories exported by this security model cannot
822 interact with other unix tools. "none
" security model is same as
823 passthrough except the sever won't report failures if it fails to
824 set file attributes like ownership. Security model is mandatory only
825 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
826 model as a parameter.
827 @item writeout=@var{writeout}
828 This is an optional argument. The only supported value is "immediate
".
829 This means that host page cache will be used to read and write data but
830 write notification will be sent to the guest only when the data has been
831 reported as written by the storage subsystem.
833 Enables exporting 9p share as a readonly mount for guests. By default
834 read-write access is given.
835 @item socket=@var{socket}
836 Enables proxy filesystem driver to use passed socket file for
837 communicating with virtfs-proxy-helper. Usually a helper like libvirt
838 will create socketpair and pass one of the fds as sock_fd
840 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
841 descriptor for interfacing with virtfs-proxy-helper
845 DEF("virtfs_synth
", 0, QEMU_OPTION_virtfs_synth,
846 "-virtfs_synth Create synthetic file system image
\n",
850 @findex -virtfs_synth
851 Create synthetic file system image
859 DEFHEADING(USB options:)
864 DEF("usb
", 0, QEMU_OPTION_usb,
865 "-usb enable the USB
driver (will be the
default soon
)\n",
870 Enable the USB driver (will be the default soon)
873 DEF("usbdevice
", HAS_ARG, QEMU_OPTION_usbdevice,
874 "-usbdevice name add the host or guest USB device
'name'\n",
878 @item -usbdevice @var{devname}
880 Add the USB device @var{devname}. @xref{usb_devices}.
885 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
888 Pointer device that uses absolute coordinates (like a touchscreen). This
889 means QEMU is able to report the mouse position without having to grab the
890 mouse. Also overrides the PS/2 mouse emulation when activated.
892 @item disk:[format=@var{format}]:@var{file}
893 Mass storage device based on file. The optional @var{format} argument
894 will be used rather than detecting the format. Can be used to specify
895 @code{format=raw} to avoid interpreting an untrusted format header.
897 @item host:@var{bus}.@var{addr}
898 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
900 @item host:@var{vendor_id}:@var{product_id}
901 Pass through the host device identified by @var{vendor_id}:@var{product_id}
904 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
905 Serial converter to host character device @var{dev}, see @code{-serial} for the
909 Braille device. This will use BrlAPI to display the braille output on a real
912 @item net:@var{options}
913 Network adapter that supports CDC ethernet and RNDIS protocols.
923 DEFHEADING(Display options:)
928 DEF("display
", HAS_ARG, QEMU_OPTION_display,
929 "-display sdl
[,frame
=on|off
][,alt_grab
=on|off
][,ctrl_grab
=on|off
]\n"
930 " [,window_close
=on|off
][,gl
=on|off
]|curses|none|
\n"
931 "-display gtk
[,grab_on_hover
=on|off
][,gl
=on|off
]|
\n"
932 "-display vnc
=<display
>[,<optargs
>]\n"
935 " select display type
\n"
936 "The
default display is equivalent to
\n"
937 #if defined(CONFIG_GTK)
938 "\t\"-display gtk
\"\n"
939 #elif defined(CONFIG_SDL)
940 "\t\"-display sdl
\"\n"
941 #elif defined(CONFIG_COCOA)
942 "\t\"-display cocoa
\"\n"
943 #elif defined(CONFIG_VNC)
944 "\t\"-vnc localhost
:0,to
=99,id
=default\"\n"
946 "\t\"-display none
\"\n"
950 @item -display @var{type}
952 Select type of display to use. This option is a replacement for the
953 old style -sdl/-curses/... options. Valid values for @var{type} are
956 Display video output via SDL (usually in a separate graphics
957 window; see the SDL documentation for other possibilities).
959 Display video output via curses. For graphics device models which
960 support a text mode, QEMU can display this output using a
961 curses/ncurses interface. Nothing is displayed when the graphics
962 device is in graphical mode or if the graphics device does not support
963 a text mode. Generally only the VGA device models support text mode.
965 Do not display video output. The guest will still see an emulated
966 graphics card, but its output will not be displayed to the QEMU
967 user. This option differs from the -nographic option in that it
968 only affects what is done with video output; -nographic also changes
969 the destination of the serial and parallel port data.
971 Display video output in a GTK window. This interface provides drop-down
972 menus and other UI elements to configure and control the VM during
975 Start a VNC server on display <arg>
979 DEF("nographic
", 0, QEMU_OPTION_nographic,
980 "-nographic disable graphical output and redirect serial I
/Os to console
\n",
985 Normally, if QEMU is compiled with graphical window support, it displays
986 output such as guest graphics, guest console, and the QEMU monitor in a
987 window. With this option, you can totally disable graphical output so
988 that QEMU is a simple command line application. The emulated serial port
989 is redirected on the console and muxed with the monitor (unless
990 redirected elsewhere explicitly). Therefore, you can still use QEMU to
991 debug a Linux kernel with a serial console. Use @key{C-a h} for help on
992 switching between the console and monitor.
995 DEF("curses
", 0, QEMU_OPTION_curses,
996 "-curses shorthand
for -display curses
\n",
1001 Normally, if QEMU is compiled with graphical window support, it displays
1002 output such as guest graphics, guest console, and the QEMU monitor in a
1003 window. With this option, QEMU can display the VGA output when in text
1004 mode using a curses/ncurses interface. Nothing is displayed in graphical
1008 DEF("no
-frame
", 0, QEMU_OPTION_no_frame,
1009 "-no
-frame open SDL window without a frame and window decorations
\n",
1014 Do not use decorations for SDL windows and start them using the whole
1015 available screen space. This makes the using QEMU in a dedicated desktop
1016 workspace more convenient.
1019 DEF("alt
-grab
", 0, QEMU_OPTION_alt_grab,
1020 "-alt
-grab use Ctrl
-Alt
-Shift to grab
mouse (instead of Ctrl
-Alt
)\n",
1025 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1026 affects the special keys (for fullscreen, monitor-mode switching, etc).
1029 DEF("ctrl
-grab
", 0, QEMU_OPTION_ctrl_grab,
1030 "-ctrl
-grab use Right
-Ctrl to grab
mouse (instead of Ctrl
-Alt
)\n",
1035 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1036 affects the special keys (for fullscreen, monitor-mode switching, etc).
1039 DEF("no
-quit
", 0, QEMU_OPTION_no_quit,
1040 "-no
-quit disable SDL window close capability
\n", QEMU_ARCH_ALL)
1044 Disable SDL window close capability.
1047 DEF("sdl
", 0, QEMU_OPTION_sdl,
1048 "-sdl shorthand
for -display sdl
\n", QEMU_ARCH_ALL)
1055 DEF("spice
", HAS_ARG, QEMU_OPTION_spice,
1056 "-spice
[port
=port
][,tls
-port
=secured
-port
][,x509
-dir
=<dir
>]\n"
1057 " [,x509
-key
-file
=<file
>][,x509
-key
-password
=<file
>]\n"
1058 " [,x509
-cert
-file
=<file
>][,x509
-cacert
-file
=<file
>]\n"
1059 " [,x509
-dh
-key
-file
=<file
>][,addr
=addr
][,ipv4|ipv6|unix
]\n"
1060 " [,tls
-ciphers
=<list
>]\n"
1061 " [,tls
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
1062 " [,plaintext
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
1063 " [,sasl
][,password
=<secret
>][,disable
-ticketing
]\n"
1064 " [,image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]]\n"
1065 " [,jpeg
-wan
-compression
=[auto|
never|always
]]\n"
1066 " [,zlib
-glz
-wan
-compression
=[auto|
never|always
]]\n"
1067 " [,streaming
-video
=[off|all|filter
]][,disable
-copy
-paste
]\n"
1068 " [,disable
-agent
-file
-xfer
][,agent
-mouse
=[on|off
]]\n"
1069 " [,playback
-compression
=[on|off
]][,seamless
-migration
=[on|off
]]\n"
1072 " at least one of
{port
, tls
-port
} is mandatory
\n",
1075 @item -spice @var{option}[,@var{option}[,...]]
1077 Enable the spice remote desktop protocol. Valid options are
1082 Set the TCP port spice is listening on for plaintext channels.
1085 Set the IP address spice is listening on. Default is any address.
1090 Force using the specified IP version.
1092 @item password=<secret>
1093 Set the password you need to authenticate.
1096 Require that the client use SASL to authenticate with the spice.
1097 The exact choice of authentication method used is controlled from the
1098 system / user's SASL configuration file for the 'qemu' service. This
1099 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1100 unprivileged user, an environment variable SASL_CONF_PATH can be used
1101 to make it search alternate locations for the service config.
1102 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1103 it is recommended that SASL always be combined with the 'tls' and
1104 'x509' settings to enable use of SSL and server certificates. This
1105 ensures a data encryption preventing compromise of authentication
1108 @item disable-ticketing
1109 Allow client connects without authentication.
1111 @item disable-copy-paste
1112 Disable copy paste between the client and the guest.
1114 @item disable-agent-file-xfer
1115 Disable spice-vdagent based file-xfer between the client and the guest.
1118 Set the TCP port spice is listening on for encrypted channels.
1120 @item x509-dir=<dir>
1121 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1123 @item x509-key-file=<file>
1124 @itemx x509-key-password=<file>
1125 @itemx x509-cert-file=<file>
1126 @itemx x509-cacert-file=<file>
1127 @itemx x509-dh-key-file=<file>
1128 The x509 file names can also be configured individually.
1130 @item tls-ciphers=<list>
1131 Specify which ciphers to use.
1133 @item tls-channel=[main|display|cursor|inputs|record|playback]
1134 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1135 Force specific channel to be used with or without TLS encryption. The
1136 options can be specified multiple times to configure multiple
1137 channels. The special name "default" can be used to set the default
1138 mode. For channels which are not explicitly forced into one mode the
1139 spice client is allowed to pick tls/plaintext as he pleases.
1141 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1142 Configure image compression (lossless).
1143 Default is auto_glz.
1145 @item jpeg-wan-compression=[auto|never|always]
1146 @itemx zlib-glz-wan-compression=[auto|never|always]
1147 Configure wan image compression (lossy for slow links).
1150 @item streaming-video=[off|all|filter]
1151 Configure video stream detection. Default is off.
1153 @item agent-mouse=[on|off]
1154 Enable/disable passing mouse events via vdagent. Default is on.
1156 @item playback-compression=[on|off]
1157 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1159 @item seamless-migration=[on|off]
1160 Enable/disable spice seamless migration. Default is off.
1163 Enable/disable OpenGL context. Default is off.
1168 DEF("portrait
", 0, QEMU_OPTION_portrait,
1169 "-portrait rotate graphical output
90 deg
left (only PXA LCD
)\n",
1174 Rotate graphical output 90 deg left (only PXA LCD).
1177 DEF("rotate
", HAS_ARG, QEMU_OPTION_rotate,
1178 "-rotate
<deg
> rotate graphical output some deg
left (only PXA LCD
)\n",
1181 @item -rotate @var{deg}
1183 Rotate graphical output some deg left (only PXA LCD).
1186 DEF("vga
", HAS_ARG, QEMU_OPTION_vga,
1187 "-vga
[std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none
]\n"
1188 " select video card type
\n", QEMU_ARCH_ALL)
1190 @item -vga @var{type}
1192 Select type of VGA card to emulate. Valid values for @var{type} are
1195 Cirrus Logic GD5446 Video card. All Windows versions starting from
1196 Windows 95 should recognize and use this graphic card. For optimal
1197 performances, use 16 bit color depth in the guest and the host OS.
1198 (This one is the default)
1200 Standard VGA card with Bochs VBE extensions. If your guest OS
1201 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1202 to use high resolution modes (>= 1280x1024x16) then you should use
1205 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1206 recent XFree86/XOrg server or Windows guest with a driver for this
1209 QXL paravirtual graphic card. It is VGA compatible (including VESA
1210 2.0 VBE support). Works best with qxl guest drivers installed though.
1211 Recommended choice when using the spice protocol.
1213 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1214 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1215 fixed resolution of 1024x768.
1217 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1218 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1219 resolutions aimed at people wishing to run older Solaris versions.
1227 DEF("full
-screen
", 0, QEMU_OPTION_full_screen,
1228 "-full
-screen start
in full screen
\n", QEMU_ARCH_ALL)
1231 @findex -full-screen
1232 Start in full screen.
1235 DEF("g
", 1, QEMU_OPTION_g ,
1236 "-g WxH
[xDEPTH
] Set the initial graphical resolution and depth
\n",
1237 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1239 @item -g @var{width}x@var{height}[x@var{depth}]
1241 Set the initial graphical resolution and depth (PPC, SPARC only).
1244 DEF("vnc
", HAS_ARG, QEMU_OPTION_vnc ,
1245 "-vnc
<display
> shorthand
for -display vnc
=<display
>\n", QEMU_ARCH_ALL)
1247 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1249 Normally, if QEMU is compiled with graphical window support, it displays
1250 output such as guest graphics, guest console, and the QEMU monitor in a
1251 window. With this option, you can have QEMU listen on VNC display
1252 @var{display} and redirect the VGA display over the VNC session. It is
1253 very useful to enable the usb tablet device when using this option
1254 (option @option{-usbdevice tablet}). When using the VNC display, you
1255 must use the @option{-k} parameter to set the keyboard layout if you are
1256 not using en-us. Valid syntax for the @var{display} is
1262 With this option, QEMU will try next available VNC @var{display}s, until the
1263 number @var{L}, if the origianlly defined "-vnc @
var{display
}" is not
1264 available, e.g. port 5900+@var{display} is already used by another
1265 application. By default, to=0.
1267 @item @var{host}:@var{d}
1269 TCP connections will only be allowed from @var{host} on display @var{d}.
1270 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1271 be omitted in which case the server will accept connections from any host.
1273 @item unix:@var{path}
1275 Connections will be allowed over UNIX domain sockets where @var{path} is the
1276 location of a unix socket to listen for connections on.
1280 VNC is initialized but not started. The monitor @code{change} command
1281 can be used to later start the VNC server.
1285 Following the @var{display} value there may be one or more @var{option} flags
1286 separated by commas. Valid options are
1292 Connect to a listening VNC client via a ``reverse'' connection. The
1293 client is specified by the @var{display}. For reverse network
1294 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1295 is a TCP port number, not a display number.
1299 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1300 By definition the Websocket port is 5700+@var{display}. If @var{host} is
1301 specified connections will only be allowed from this host.
1302 As an alternative the Websocket port could be specified by using
1303 @code{websocket}=@var{port}.
1304 If no TLS credentials are provided, the websocket connection runs in
1305 unencrypted mode. If TLS credentials are provided, the websocket connection
1306 requires encrypted client connections.
1310 Require that password based authentication is used for client connections.
1312 The password must be set separately using the @code{set_password} command in
1313 the @ref{pcsys_monitor}. The syntax to change your password is:
1314 @code{set_password <protocol> <password>} where <protocol> could be either
1317 If you would like to change <protocol> password expiration, you should use
1318 @code{expire_password <protocol> <expiration-time>} where expiration time could
1319 be one of the following options: now, never, +seconds or UNIX time of
1320 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1321 to make password expire on "Mon Apr
23 12:00:00 EDT
2012" (UNIX time for this
1324 You can also use keywords "now
" or "never" for the expiration time to
1325 allow <protocol> password to expire immediately or never expire.
1327 @item tls-creds=@var{ID}
1329 Provides the ID of a set of TLS credentials to use to secure the
1330 VNC server. They will apply to both the normal VNC server socket
1331 and the websocket socket (if enabled). Setting TLS credentials
1332 will cause the VNC server socket to enable the VeNCrypt auth
1333 mechanism. The credentials should have been previously created
1334 using the @option{-object tls-creds} argument.
1336 The @option{tls-creds} parameter obsoletes the @option{tls},
1337 @option{x509}, and @option{x509verify} options, and as such
1338 it is not permitted to set both new and old type options at
1343 Require that client use TLS when communicating with the VNC server. This
1344 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1345 attack. It is recommended that this option be combined with either the
1346 @option{x509} or @option{x509verify} options.
1348 This option is now deprecated in favor of using the @option{tls-creds}
1351 @item x509=@var{/path/to/certificate/dir}
1353 Valid if @option{tls} is specified. Require that x509 credentials are used
1354 for negotiating the TLS session. The server will send its x509 certificate
1355 to the client. It is recommended that a password be set on the VNC server
1356 to provide authentication of the client when this is used. The path following
1357 this option specifies where the x509 certificates are to be loaded from.
1358 See the @ref{vnc_security} section for details on generating certificates.
1360 This option is now deprecated in favour of using the @option{tls-creds}
1363 @item x509verify=@var{/path/to/certificate/dir}
1365 Valid if @option{tls} is specified. Require that x509 credentials are used
1366 for negotiating the TLS session. The server will send its x509 certificate
1367 to the client, and request that the client send its own x509 certificate.
1368 The server will validate the client's certificate against the CA certificate,
1369 and reject clients when validation fails. If the certificate authority is
1370 trusted, this is a sufficient authentication mechanism. You may still wish
1371 to set a password on the VNC server as a second authentication layer. The
1372 path following this option specifies where the x509 certificates are to
1373 be loaded from. See the @ref{vnc_security} section for details on generating
1376 This option is now deprecated in favour of using the @option{tls-creds}
1381 Require that the client use SASL to authenticate with the VNC server.
1382 The exact choice of authentication method used is controlled from the
1383 system / user's SASL configuration file for the 'qemu' service. This
1384 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1385 unprivileged user, an environment variable SASL_CONF_PATH can be used
1386 to make it search alternate locations for the service config.
1387 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1388 it is recommended that SASL always be combined with the 'tls' and
1389 'x509' settings to enable use of SSL and server certificates. This
1390 ensures a data encryption preventing compromise of authentication
1391 credentials. See the @ref{vnc_security} section for details on using
1392 SASL authentication.
1396 Turn on access control lists for checking of the x509 client certificate
1397 and SASL party. For x509 certs, the ACL check is made against the
1398 certificate's distinguished name. This is something that looks like
1399 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1400 made against the username, which depending on the SASL plugin, may
1401 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1402 When the @option{acl} flag is set, the initial access list will be
1403 empty, with a @code{deny} policy. Thus no one will be allowed to
1404 use the VNC server until the ACLs have been loaded. This can be
1405 achieved using the @code{acl} monitor command.
1409 Enable lossy compression methods (gradient, JPEG, ...). If this
1410 option is set, VNC client may receive lossy framebuffer updates
1411 depending on its encoding settings. Enabling this option can save
1412 a lot of bandwidth at the expense of quality.
1416 Disable adaptive encodings. Adaptive encodings are enabled by default.
1417 An adaptive encoding will try to detect frequently updated screen regions,
1418 and send updates in these regions using a lossy encoding (like JPEG).
1419 This can be really helpful to save bandwidth when playing videos. Disabling
1420 adaptive encodings restores the original static behavior of encodings
1423 @item share=[allow-exclusive|force-shared|ignore]
1425 Set display sharing policy. 'allow-exclusive' allows clients to ask
1426 for exclusive access. As suggested by the rfb spec this is
1427 implemented by dropping other connections. Connecting multiple
1428 clients in parallel requires all clients asking for a shared session
1429 (vncviewer: -shared switch). This is the default. 'force-shared'
1430 disables exclusive client access. Useful for shared desktop sessions,
1431 where you don't want someone forgetting specify -shared disconnect
1432 everybody else. 'ignore' completely ignores the shared flag and
1433 allows everybody connect unconditionally. Doesn't conform to the rfb
1434 spec but is traditional QEMU behavior.
1438 Set keyboard delay, for key down and key up events, in milliseconds.
1439 Default is 1. Keyboards are low-bandwidth devices, so this slowdown
1440 can help the device and guest to keep up and not lose events in case
1441 events are arriving in bulk. Possible causes for the latter are flaky
1442 network connections, or scripts for automated testing.
1450 ARCHHEADING(, QEMU_ARCH_I386)
1452 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1457 DEF("win2k
-hack
", 0, QEMU_OPTION_win2k_hack,
1458 "-win2k
-hack use it when installing Windows
2000 to avoid a disk full bug
\n",
1463 Use it when installing Windows 2000 to avoid a disk full bug. After
1464 Windows 2000 is installed, you no longer need this option (this option
1465 slows down the IDE transfers).
1468 HXCOMM Deprecated by -rtc
1469 DEF("rtc
-td
-hack
", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1471 DEF("no
-fd
-bootchk
", 0, QEMU_OPTION_no_fd_bootchk,
1472 "-no
-fd
-bootchk disable boot signature checking
for floppy disks
\n",
1475 @item -no-fd-bootchk
1476 @findex -no-fd-bootchk
1477 Disable boot signature checking for floppy disks in BIOS. May
1478 be needed to boot from old floppy disks.
1481 DEF("no
-acpi
", 0, QEMU_OPTION_no_acpi,
1482 "-no
-acpi disable ACPI
\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1486 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1487 it if your guest OS complains about ACPI problems (PC target machine
1491 DEF("no
-hpet
", 0, QEMU_OPTION_no_hpet,
1492 "-no
-hpet disable HPET
\n", QEMU_ARCH_I386)
1496 Disable HPET support.
1499 DEF("acpitable
", HAS_ARG, QEMU_OPTION_acpitable,
1500 "-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"
1501 " ACPI table description
\n", QEMU_ARCH_I386)
1503 @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}]...]
1505 Add ACPI table with specified header fields and context from specified files.
1506 For file=, take whole ACPI table from the specified files, including all
1507 ACPI headers (possible overridden by other options).
1508 For data=, only data
1509 portion of the table is used, all header information is specified in the
1511 If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1512 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1513 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1517 DEF("smbios
", HAS_ARG, QEMU_OPTION_smbios,
1518 "-smbios file
=binary
\n"
1519 " load SMBIOS entry from binary file
\n"
1520 "-smbios type
=0[,vendor
=str
][,version
=str
][,date
=str
][,release
=%d
.%d
]\n"
1522 " specify SMBIOS type
0 fields
\n"
1523 "-smbios type
=1[,manufacturer
=str
][,product
=str
][,version
=str
][,serial
=str
]\n"
1524 " [,uuid
=uuid
][,sku
=str
][,family
=str
]\n"
1525 " specify SMBIOS type
1 fields
\n"
1526 "-smbios type
=2[,manufacturer
=str
][,product
=str
][,version
=str
][,serial
=str
]\n"
1527 " [,asset
=str
][,location
=str
]\n"
1528 " specify SMBIOS type
2 fields
\n"
1529 "-smbios type
=3[,manufacturer
=str
][,version
=str
][,serial
=str
][,asset
=str
]\n"
1531 " specify SMBIOS type
3 fields
\n"
1532 "-smbios type
=4[,sock_pfx
=str
][,manufacturer
=str
][,version
=str
][,serial
=str
]\n"
1533 " [,asset
=str
][,part
=str
]\n"
1534 " specify SMBIOS type
4 fields
\n"
1535 "-smbios type
=17[,loc_pfx
=str
][,bank
=str
][,manufacturer
=str
][,serial
=str
]\n"
1536 " [,asset
=str
][,part
=str
][,speed
=%d
]\n"
1537 " specify SMBIOS type
17 fields
\n",
1538 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1540 @item -smbios file=@var{binary}
1542 Load SMBIOS entry from binary file.
1544 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1545 Specify SMBIOS type 0 fields
1547 @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}]
1548 Specify SMBIOS type 1 fields
1550 @item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}][,family=@var{str}]
1551 Specify SMBIOS type 2 fields
1553 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1554 Specify SMBIOS type 3 fields
1556 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1557 Specify SMBIOS type 4 fields
1559 @item -smbios type=17[,loc_pfx=@var{str}][,bank=@var{str}][,manufacturer=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}][,speed=@var{%d}]
1560 Specify SMBIOS type 17 fields
1568 DEFHEADING(Network options:)
1573 HXCOMM Legacy slirp options (now moved to -net user):
1575 DEF("tftp
", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1576 DEF("bootp
", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1577 DEF("redir
", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1579 DEF("smb
", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1583 DEF("netdev
", HAS_ARG, QEMU_OPTION_netdev,
1585 "-netdev user
,id
=str
[,ipv4
[=on|off
]][,net
=addr
[/mask
]][,host
=addr
]\n"
1586 " [,ipv6
[=on|off
]][,ipv6
-net
=addr
[/int
]][,ipv6
-host
=addr
]\n"
1587 " [,restrict
=on|off
][,hostname
=host
][,dhcpstart
=addr
]\n"
1588 " [,dns
=addr
][,ipv6
-dns
=addr
][,dnssearch
=domain
][,tftp
=dir
]\n"
1589 " [,bootfile
=f
][,hostfwd
=rule
][,guestfwd
=rule
]"
1591 "[,smb
=dir
[,smbserver
=addr
]]\n"
1593 " configure a user mode network backend with ID
'str',\n"
1594 " its DHCP server and optional services
\n"
1597 "-netdev tap
,id
=str
,ifname
=name
\n"
1598 " configure a host TAP network backend with ID
'str'\n"
1600 "-netdev tap
,id
=str
[,fd
=h
][,fds
=x
:y
:...:z
][,ifname
=name
][,script
=file
][,downscript
=dfile
]\n"
1601 " [,helper
=helper
][,sndbuf
=nbytes
][,vnet_hdr
=on|off
][,vhost
=on|off
]\n"
1602 " [,vhostfd
=h
][,vhostfds
=x
:y
:...:z
][,vhostforce
=on|off
][,queues
=n
]\n"
1604 " configure a host TAP network backend with ID
'str'\n"
1605 " use network scripts
'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1606 " to configure it and
'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1607 " to deconfigure it
\n"
1608 " use
'[down]script=no' to disable script execution
\n"
1609 " use network helper
'helper' (default=" DEFAULT_BRIDGE_HELPER ") to
\n"
1611 " use
'fd=h' to connect to an already opened TAP
interface\n"
1612 " use
'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces
\n"
1613 " use
'sndbuf=nbytes' to limit the size of the send
buffer (the
\n"
1614 " default is disabled
'sndbuf=0' to enable flow control set
'sndbuf=1048576')\n"
1615 " use vnet_hdr
=off to avoid enabling the IFF_VNET_HDR tap flag
\n"
1616 " use vnet_hdr
=on to make the lack of IFF_VNET_HDR support an error condition
\n"
1617 " use vhost
=on to enable experimental
in kernel accelerator
\n"
1618 " (only has effect
for virtio guests which use MSIX
)\n"
1619 " use vhostforce
=on to force vhost on
for non
-MSIX virtio guests
\n"
1620 " use
'vhostfd=h' to connect to an already opened vhost net device
\n"
1621 " use
'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1622 " use 'queues
=n
' to specify the number of queues to be created for multiqueue TAP\n"
1623 " use 'poll
-us
=n
' to speciy the maximum number of microseconds that could be\n"
1624 " spent on busy polling for vhost net\n"
1625 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1626 " configure a host TAP network backend with ID 'str
' that is\n"
1627 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1628 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1631 "-netdev l2tpv3
,id
=str
,src
=srcaddr
,dst
=dstaddr
[,srcport
=srcport
][,dstport
=dstport
]\n"
1632 " [,rxsession
=rxsession
],txsession
=txsession
[,ipv6
=on
/off
][,udp
=on
/off
]\n"
1633 " [,cookie64
=on
/off
][,counter
][,pincounter
][,txcookie
=txcookie
]\n"
1634 " [,rxcookie
=rxcookie
][,offset
=offset
]\n"
1635 " configure a network backend with ID
'str' connected to
\n"
1636 " an Ethernet over L2TPv3 pseudowire
.\n"
1637 " Linux kernel
3.3+ as well as most routers can talk
\n"
1638 " L2TPv3
. This transport allows connecting a VM to a VM
,\n"
1639 " VM to a router and even VM to Host
. It is a nearly
-universal
\n"
1640 " standard (RFC3391
). Note
- this implementation uses
static\n"
1641 " pre
-configured
tunnels (same as the Linux kernel
).\n"
1642 " use
'src=' to specify source address
\n"
1643 " use
'dst=' to specify destination address
\n"
1644 " use
'udp=on' to specify udp encapsulation
\n"
1645 " use
'srcport=' to specify source udp port
\n"
1646 " use
'dstport=' to specify destination udp port
\n"
1647 " use
'ipv6=on' to force v6
\n"
1648 " L2TPv3 uses cookies to prevent misconfiguration as
\n"
1649 " well as a weak security measure
\n"
1650 " use
'rxcookie=0x012345678' to specify a rxcookie
\n"
1651 " use
'txcookie=0x012345678' to specify a txcookie
\n"
1652 " use
'cookie64=on' to set cookie size to
64 bit
, otherwise
32\n"
1653 " use
'counter=off' to force a
'cut-down' L2TPv3 with no counter
\n"
1654 " use
'pincounter=on' to work around broken counter handling
in peer
\n"
1655 " use
'offset=X' to add an extra offset between header and data
\n"
1657 "-netdev socket
,id
=str
[,fd
=h
][,listen
=[host
]:port
][,connect
=host
:port
]\n"
1658 " configure a network backend to connect to another network
\n"
1659 " using a socket connection
\n"
1660 "-netdev socket
,id
=str
[,fd
=h
][,mcast
=maddr
:port
[,localaddr
=addr
]]\n"
1661 " configure a network backend to connect to a multicast maddr and port
\n"
1662 " use
'localaddr=addr' to specify the host address to send packets from
\n"
1663 "-netdev socket
,id
=str
[,fd
=h
][,udp
=host
:port
][,localaddr
=host
:port
]\n"
1664 " configure a network backend to connect to another network
\n"
1665 " using an UDP tunnel
\n"
1667 "-netdev vde
,id
=str
[,sock
=socketpath
][,port
=n
][,group
=groupname
][,mode
=octalmode
]\n"
1668 " configure a network backend to connect to port
'n' of a vde
switch\n"
1669 " running on host and listening
for incoming connections on
'socketpath'.\n"
1670 " Use group
'groupname' and mode
'octalmode' to change
default\n"
1671 " ownership and permissions
for communication port
.\n"
1673 #ifdef CONFIG_NETMAP
1674 "-netdev netmap
,id
=str
,ifname
=name
[,devname
=nmname
]\n"
1675 " attach to the existing netmap
-enabled network
interface 'name', or to a
\n"
1676 " VALE
port (created on the fly
) called
'name' ('nmname' is name of the
\n"
1677 " netmap device
, defaults to
'/dev/netmap')\n"
1679 "-netdev vhost
-user
,id
=str
,chardev
=dev
[,vhostforce
=on|off
]\n"
1680 " configure a vhost
-user network
, backed by a chardev
'dev'\n"
1681 "-netdev hubport
,id
=str
,hubid
=n
\n"
1682 " configure a hub port on QEMU VLAN
'n'\n", QEMU_ARCH_ALL)
1683 DEF("net
", HAS_ARG, QEMU_OPTION_net,
1684 "-net nic
[,vlan
=n
][,macaddr
=mac
][,model
=type
][,name
=str
][,addr
=str
][,vectors
=v
]\n"
1685 " old way to create a
new NIC and connect it to VLAN
'n'\n"
1686 " (use the
'-device devtype,netdev=str' option
if possible instead
)\n"
1687 "-net dump
[,vlan
=n
][,file
=f
][,len
=n
]\n"
1688 " dump traffic on vlan
'n' to file
'f' (max n bytes per packet
)\n"
1689 "-net none use it alone to have zero network devices
. If no
-net option
\n"
1690 " is provided
, the
default is
'-net nic -net user'\n"
1700 #ifdef CONFIG_NETMAP
1703 "socket
][,vlan
=n
][,option
][,option
][,...]\n"
1704 " old way to initialize a host network
interface\n"
1705 " (use the
-netdev option
if possible instead
)\n", QEMU_ARCH_ALL)
1707 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1709 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1710 = 0 is the default). The NIC is an e1000 by default on the PC
1711 target. Optionally, the MAC address can be changed to @var{mac}, the
1712 device address set to @var{addr} (PCI cards only),
1713 and a @var{name} can be assigned for use in monitor commands.
1714 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1715 that the card should have; this option currently only affects virtio cards; set
1716 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1717 NIC is created. QEMU can emulate several different models of network card.
1718 Valid values for @var{type} are
1719 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1720 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1721 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1722 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1723 for a list of available devices for your target.
1725 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1727 @item -net user[,@var{option}][,@var{option}][,...]
1728 Use the user mode network stack which requires no administrator
1729 privilege to run. Valid options are:
1733 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1736 @itemx name=@var{name}
1737 Assign symbolic name for use in monitor commands.
1739 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
1740 be enabled. If neither is specified both protocols are enabled.
1742 @item net=@var{addr}[/@var{mask}]
1743 Set IP network address the guest will see. Optionally specify the netmask,
1744 either in the form a.b.c.d or as number of valid top-most bits. Default is
1747 @item host=@var{addr}
1748 Specify the guest-visible address of the host. Default is the 2nd IP in the
1749 guest network, i.e. x.x.x.2.
1751 @item ipv6-net=@var{addr}[/@var{int}]
1752 Set IPv6 network address the guest will see (default is fec0::/64). The
1753 network prefix is given in the usual hexadecimal IPv6 address
1754 notation. The prefix size is optional, and is given as the number of
1755 valid top-most bits (default is 64).
1757 @item ipv6-host=@var{addr}
1758 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
1759 the guest network, i.e. xxxx::2.
1761 @item restrict=on|off
1762 If this option is enabled, the guest will be isolated, i.e. it will not be
1763 able to contact the host and no guest IP packets will be routed over the host
1764 to the outside. This option does not affect any explicitly set forwarding rules.
1766 @item hostname=@var{name}
1767 Specifies the client hostname reported by the built-in DHCP server.
1769 @item dhcpstart=@var{addr}
1770 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1771 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1773 @item dns=@var{addr}
1774 Specify the guest-visible address of the virtual nameserver. The address must
1775 be different from the host address. Default is the 3rd IP in the guest network,
1778 @item ipv6-dns=@var{addr}
1779 Specify the guest-visible address of the IPv6 virtual nameserver. The address
1780 must be different from the host address. Default is the 3rd IP in the guest
1781 network, i.e. xxxx::3.
1783 @item dnssearch=@var{domain}
1784 Provides an entry for the domain-search list sent by the built-in
1785 DHCP server. More than one domain suffix can be transmitted by specifying
1786 this option multiple times. If supported, this will cause the guest to
1787 automatically try to append the given domain suffix(es) in case a domain name
1788 can not be resolved.
1792 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1795 @item tftp=@var{dir}
1796 When using the user mode network stack, activate a built-in TFTP
1797 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1798 The TFTP client on the guest must be configured in binary mode (use the command
1799 @code{bin} of the Unix TFTP client).
1801 @item bootfile=@var{file}
1802 When using the user mode network stack, broadcast @var{file} as the BOOTP
1803 filename. In conjunction with @option{tftp}, this can be used to network boot
1804 a guest from a local directory.
1806 Example (using pxelinux):
1808 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1811 @item smb=@var{dir}[,smbserver=@var{addr}]
1812 When using the user mode network stack, activate a built-in SMB
1813 server so that Windows OSes can access to the host files in @file{@var{dir}}
1814 transparently. The IP address of the SMB server can be set to @var{addr}. By
1815 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1817 In the guest Windows OS, the line:
1821 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1822 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1824 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1826 Note that a SAMBA server must be installed on the host OS.
1827 QEMU was tested successfully with smbd versions from Red Hat 9,
1828 Fedora Core 3 and OpenSUSE 11.x.
1830 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1831 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1832 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1833 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1834 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1835 be bound to a specific host interface. If no connection type is set, TCP is
1836 used. This option can be given multiple times.
1838 For example, to redirect host X11 connection from screen 1 to guest
1839 screen 0, use the following:
1843 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1844 # this host xterm should open in the guest X11 server
1848 To redirect telnet connections from host port 5555 to telnet port on
1849 the guest, use the following:
1853 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1854 telnet localhost 5555
1857 Then when you use on the host @code{telnet localhost 5555}, you
1858 connect to the guest telnet server.
1860 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1861 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1862 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1863 to the character device @var{dev} or to a program executed by @var{cmd:command}
1864 which gets spawned for each connection. This option can be given multiple times.
1866 You can either use a chardev directly and have that one used throughout QEMU's
1867 lifetime, like in the following example:
1870 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
1871 # the guest accesses it
1872 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
1875 Or you can execute a command on every TCP connection established by the guest,
1876 so that QEMU behaves similar to an inetd process for that virtual server:
1879 # call "netcat
10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
1880 # and connect the TCP stream to its stdin/stdout
1881 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1886 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1887 processed and applied to -net user. Mixing them with the new configuration
1888 syntax gives undefined results. Their use for new applications is discouraged
1889 as they will be removed from future versions.
1891 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1892 @itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1893 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1895 Use the network script @var{file} to configure it and the network script
1896 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1897 automatically provides one. The default network configure script is
1898 @file{/etc/qemu-ifup} and the default network deconfigure script is
1899 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1900 to disable script execution.
1902 If running QEMU as an unprivileged user, use the network helper
1903 @var{helper} to configure the TAP interface. The default network
1904 helper executable is @file{/path/to/qemu-bridge-helper}.
1906 @option{fd}=@var{h} can be used to specify the handle of an already
1907 opened host TAP interface.
1912 #launch a QEMU instance with the default network script
1913 qemu-system-i386 linux.img -net nic -net tap
1917 #launch a QEMU instance with two NICs, each one connected
1919 qemu-system-i386 linux.img \
1920 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1921 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1925 #launch a QEMU instance with the default network helper to
1926 #connect a TAP device to bridge br0
1927 qemu-system-i386 linux.img \
1928 -net nic -net tap,"helper
=/path
/to
/qemu
-bridge
-helper
"
1931 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
1932 @itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1933 Connect a host TAP network interface to a host bridge device.
1935 Use the network helper @var{helper} to configure the TAP interface and
1936 attach it to the bridge. The default network helper executable is
1937 @file{/path/to/qemu-bridge-helper} and the default bridge
1938 device is @file{br0}.
1943 #launch a QEMU instance with the default network helper to
1944 #connect a TAP device to bridge br0
1945 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
1949 #launch a QEMU instance with the default network helper to
1950 #connect a TAP device to bridge qemubr0
1951 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1954 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1955 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1957 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1958 machine using a TCP socket connection. If @option{listen} is
1959 specified, QEMU waits for incoming connections on @var{port}
1960 (@var{host} is optional). @option{connect} is used to connect to
1961 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1962 specifies an already opened TCP socket.
1966 # launch a first QEMU instance
1967 qemu-system-i386 linux.img \
1968 -net nic,macaddr=52:54:00:12:34:56 \
1969 -net socket,listen=:1234
1970 # connect the VLAN 0 of this instance to the VLAN 0
1971 # of the first instance
1972 qemu-system-i386 linux.img \
1973 -net nic,macaddr=52:54:00:12:34:57 \
1974 -net socket,connect=127.0.0.1:1234
1977 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1978 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1980 Create a VLAN @var{n} shared with another QEMU virtual
1981 machines using a UDP multicast socket, effectively making a bus for
1982 every QEMU with same multicast address @var{maddr} and @var{port}.
1986 Several QEMU can be running on different hosts and share same bus (assuming
1987 correct multicast setup for these hosts).
1989 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1990 @url{http://user-mode-linux.sf.net}.
1992 Use @option{fd=h} to specify an already opened UDP multicast socket.
1997 # launch one QEMU instance
1998 qemu-system-i386 linux.img \
1999 -net nic,macaddr=52:54:00:12:34:56 \
2000 -net socket,mcast=230.0.0.1:1234
2001 # launch another QEMU instance on same "bus
"
2002 qemu-system-i386 linux.img \
2003 -net nic,macaddr=52:54:00:12:34:57 \
2004 -net socket,mcast=230.0.0.1:1234
2005 # launch yet another QEMU instance on same "bus
"
2006 qemu-system-i386 linux.img \
2007 -net nic,macaddr=52:54:00:12:34:58 \
2008 -net socket,mcast=230.0.0.1:1234
2011 Example (User Mode Linux compat.):
2013 # launch QEMU instance (note mcast address selected
2015 qemu-system-i386 linux.img \
2016 -net nic,macaddr=52:54:00:12:34:56 \
2017 -net socket,mcast=239.192.168.1:1102
2019 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2022 Example (send packets from host's 1.2.3.4):
2024 qemu-system-i386 linux.img \
2025 -net nic,macaddr=52:54:00:12:34:56 \
2026 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2029 @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}]
2030 @itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}]
2031 Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
2032 protocol to transport Ethernet (and other Layer 2) data frames between
2033 two systems. It is present in routers, firewalls and the Linux kernel
2034 (from version 3.3 onwards).
2036 This transport allows a VM to communicate to another VM, router or firewall directly.
2038 @item src=@var{srcaddr}
2039 source address (mandatory)
2040 @item dst=@var{dstaddr}
2041 destination address (mandatory)
2043 select udp encapsulation (default is ip).
2044 @item srcport=@var{srcport}
2046 @item dstport=@var{dstport}
2047 destination udp port.
2049 force v6, otherwise defaults to v4.
2050 @item rxcookie=@var{rxcookie}
2051 @itemx txcookie=@var{txcookie}
2052 Cookies are a weak form of security in the l2tpv3 specification.
2053 Their function is mostly to prevent misconfiguration. By default they are 32
2056 Set cookie size to 64 bit instead of the default 32
2058 Force a 'cut-down' L2TPv3 with no counter as in
2059 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2061 Work around broken counter handling in peer. This may also help on
2062 networks which have packet reorder.
2063 @item offset=@var{offset}
2064 Add an extra offset between header and data
2066 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2067 on the remote Linux host 1.2.3.4:
2069 # Setup tunnel on linux host using raw ip as encapsulation
2071 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2072 encap udp udp_sport 16384 udp_dport 16384
2073 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2074 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2075 ifconfig vmtunnel0 mtu 1500
2076 ifconfig vmtunnel0 up
2077 brctl addif br-lan vmtunnel0
2081 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2083 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
2088 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2089 @itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2090 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2091 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2092 and MODE @var{octalmode} to change default ownership and permissions for
2093 communication port. This option is only available if QEMU has been compiled
2094 with vde support enabled.
2099 vde_switch -F -sock /tmp/myswitch
2100 # launch QEMU instance
2101 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2104 @item -netdev hubport,id=@var{id},hubid=@var{hubid}
2106 Create a hub port on QEMU "vlan
" @var{hubid}.
2108 The hubport netdev lets you connect a NIC to a QEMU "vlan
" instead of a single
2109 netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
2110 required hub automatically.
2112 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2114 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2115 be a unix domain socket backed one. The vhost-user uses a specifically defined
2116 protocol to pass vhost ioctl replacement messages to an application on the other
2117 end of the socket. On non-MSIX guests, the feature can be forced with
2118 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2119 be created for multiqueue vhost-user.
2123 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2124 -numa node,memdev=mem \
2125 -chardev socket,path=/path/to/socket \
2126 -netdev type=vhost-user,id=net0,chardev=chr0 \
2127 -device virtio-net-pci,netdev=net0
2130 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
2131 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
2132 At most @var{len} bytes (64k by default) per packet are stored. The file format is
2133 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
2134 Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
2137 Indicate that no network devices should be configured. It is used to
2138 override the default configuration (@option{-net nic -net user}) which
2139 is activated if no @option{-net} options are provided.
2147 DEFHEADING(Character device options:)
2150 The general form of a character device option is:
2154 DEF("chardev
", HAS_ARG, QEMU_OPTION_chardev,
2155 "-chardev
null,id
=id
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2156 "-chardev socket
,id
=id
[,host
=host
],port
=port
[,to
=to
][,ipv4
][,ipv6
][,nodelay
][,reconnect
=seconds
]\n"
2157 " [,server
][,nowait
][,telnet
][,reconnect
=seconds
][,mux
=on|off
]\n"
2158 " [,logfile
=PATH
][,logappend
=on|off
][,tls
-creds
=ID
] (tcp
)\n"
2159 "-chardev socket
,id
=id
,path
=path
[,server
][,nowait
][,telnet
][,reconnect
=seconds
]\n"
2160 " [,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
] (unix
)\n"
2161 "-chardev udp
,id
=id
[,host
=host
],port
=port
[,localaddr
=localaddr
]\n"
2162 " [,localport
=localport
][,ipv4
][,ipv6
][,mux
=on|off
]\n"
2163 " [,logfile
=PATH
][,logappend
=on|off
]\n"
2164 "-chardev msmouse
,id
=id
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2165 "-chardev vc
,id
=id
[[,width
=width
][,height
=height
]][[,cols
=cols
][,rows
=rows
]]\n"
2166 " [,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2167 "-chardev ringbuf
,id
=id
[,size
=size
][,logfile
=PATH
][,logappend
=on|off
]\n"
2168 "-chardev file
,id
=id
,path
=path
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2169 "-chardev pipe
,id
=id
,path
=path
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2171 "-chardev console
,id
=id
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2172 "-chardev serial
,id
=id
,path
=path
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2174 "-chardev pty
,id
=id
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2175 "-chardev stdio
,id
=id
[,mux
=on|off
][,signal
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2177 #ifdef CONFIG_BRLAPI
2178 "-chardev braille
,id
=id
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2180 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2181 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2182 "-chardev serial
,id
=id
,path
=path
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2183 "-chardev tty
,id
=id
,path
=path
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2185 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2186 "-chardev parallel
,id
=id
,path
=path
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2187 "-chardev parport
,id
=id
,path
=path
[,mux
=on|off
][,logfile
=PATH
][,logappend
=on|off
]\n"
2189 #if defined(CONFIG_SPICE)
2190 "-chardev spicevmc
,id
=id
,name
=name
[,debug
=debug
][,logfile
=PATH
][,logappend
=on|off
]\n"
2191 "-chardev spiceport
,id
=id
,name
=name
[,debug
=debug
][,logfile
=PATH
][,logappend
=on|off
]\n"
2197 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
2218 The specific backend will determine the applicable options.
2220 All devices must have an id, which can be any string up to 127 characters long.
2221 It is used to uniquely identify this device in other command line directives.
2223 A character device may be used in multiplexing mode by multiple front-ends.
2224 Specify @option{mux=on} to enable this mode.
2225 A multiplexer is a "1:N
" device, and here the "1" end is your specified chardev
2226 backend, and the "N
" end is the various parts of QEMU that can talk to a chardev.
2227 If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2228 create a multiplexer with your specified ID, and you can then configure multiple
2229 front ends to use that chardev ID for their input/output. Up to four different
2230 front ends can be connected to a single multiplexed chardev. (Without
2231 multiplexing enabled, a chardev can only be used by a single front end.)
2232 For instance you could use this to allow a single stdio chardev to be used by
2233 two serial ports and the QEMU monitor:
2236 -chardev stdio,mux=on,id=char0 \
2237 -mon chardev=char0,mode=readline,default \
2238 -serial chardev:char0 \
2239 -serial chardev:char0
2242 You can have more than one multiplexer in a system configuration; for instance
2243 you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2244 multiplexed between the QEMU monitor and a parallel port:
2247 -chardev stdio,mux=on,id=char0 \
2248 -mon chardev=char0,mode=readline,default \
2249 -parallel chardev:char0 \
2250 -chardev tcp,...,mux=on,id=char1 \
2251 -serial chardev:char1 \
2252 -serial chardev:char1
2255 When you're using a multiplexed character device, some escape sequences are
2256 interpreted in the input. @xref{mux_keys, Keys in the character backend
2259 Note that some other command line options may implicitly create multiplexed
2260 character backends; for instance @option{-serial mon:stdio} creates a
2261 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2262 and @option{-nographic} also multiplexes the console and the monitor to
2265 There is currently no support for multiplexing in the other direction
2266 (where a single QEMU front end takes input and output from multiple chardevs).
2268 Every backend supports the @option{logfile} option, which supplies the path
2269 to a file to record all data transmitted via the backend. The @option{logappend}
2270 option controls whether the log file will be truncated or appended to when
2273 Further options to each backend are described below.
2275 @item -chardev null ,id=@var{id}
2276 A void device. This device will not emit any data, and will drop any data it
2277 receives. The null backend does not take any options.
2279 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}]
2281 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2282 unix socket will be created if @option{path} is specified. Behaviour is
2283 undefined if TCP options are specified for a unix socket.
2285 @option{server} specifies that the socket shall be a listening socket.
2287 @option{nowait} specifies that QEMU should not block waiting for a client to
2288 connect to a listening socket.
2290 @option{telnet} specifies that traffic on the socket should interpret telnet
2293 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2294 the remote end goes away. qemu will delay this many seconds and then attempt
2295 to reconnect. Zero disables reconnecting, and is the default.
2297 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2298 and specifies the id of the TLS credentials to use for the handshake. The
2299 credentials must be previously created with the @option{-object tls-creds}
2302 TCP and unix socket options are given below:
2306 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2308 @option{host} for a listening socket specifies the local address to be bound.
2309 For a connecting socket species the remote host to connect to. @option{host} is
2310 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2312 @option{port} for a listening socket specifies the local port to be bound. For a
2313 connecting socket specifies the port on the remote host to connect to.
2314 @option{port} can be given as either a port number or a service name.
2315 @option{port} is required.
2317 @option{to} is only relevant to listening sockets. If it is specified, and
2318 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2319 to and including @option{to} until it succeeds. @option{to} must be specified
2322 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2323 If neither is specified the socket may use either protocol.
2325 @option{nodelay} disables the Nagle algorithm.
2327 @item unix options: path=@var{path}
2329 @option{path} specifies the local path of the unix socket. @option{path} is
2334 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2336 Sends all traffic from the guest to a remote host over UDP.
2338 @option{host} specifies the remote host to connect to. If not specified it
2339 defaults to @code{localhost}.
2341 @option{port} specifies the port on the remote host to connect to. @option{port}
2344 @option{localaddr} specifies the local address to bind to. If not specified it
2345 defaults to @code{0.0.0.0}.
2347 @option{localport} specifies the local port to bind to. If not specified any
2348 available local port will be used.
2350 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2351 If neither is specified the device may use either protocol.
2353 @item -chardev msmouse ,id=@var{id}
2355 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2358 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2360 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2363 @option{width} and @option{height} specify the width and height respectively of
2364 the console, in pixels.
2366 @option{cols} and @option{rows} specify that the console be sized to fit a text
2367 console with the given dimensions.
2369 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2371 Create a ring buffer with fixed size @option{size}.
2372 @var{size} must be a power of two, and defaults to @code{64K}).
2374 @item -chardev file ,id=@var{id} ,path=@var{path}
2376 Log all traffic received from the guest to a file.
2378 @option{path} specifies the path of the file to be opened. This file will be
2379 created if it does not already exist, and overwritten if it does. @option{path}
2382 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2384 Create a two-way connection to the guest. The behaviour differs slightly between
2385 Windows hosts and other hosts:
2387 On Windows, a single duplex pipe will be created at
2388 @file{\\.pipe\@option{path}}.
2390 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2391 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2392 received by the guest. Data written by the guest can be read from
2393 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2396 @option{path} forms part of the pipe path as described above. @option{path} is
2399 @item -chardev console ,id=@var{id}
2401 Send traffic from the guest to QEMU's standard output. @option{console} does not
2404 @option{console} is only available on Windows hosts.
2406 @item -chardev serial ,id=@var{id} ,path=@option{path}
2408 Send traffic from the guest to a serial device on the host.
2410 On Unix hosts serial will actually accept any tty device,
2411 not only serial lines.
2413 @option{path} specifies the name of the serial device to open.
2415 @item -chardev pty ,id=@var{id}
2417 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2418 not take any options.
2420 @option{pty} is not available on Windows hosts.
2422 @item -chardev stdio ,id=@var{id} [,signal=on|off]
2423 Connect to standard input and standard output of the QEMU process.
2425 @option{signal} controls if signals are enabled on the terminal, that includes
2426 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2427 default, use @option{signal=off} to disable it.
2429 @option{stdio} is not available on Windows hosts.
2431 @item -chardev braille ,id=@var{id}
2433 Connect to a local BrlAPI server. @option{braille} does not take any options.
2435 @item -chardev tty ,id=@var{id} ,path=@var{path}
2437 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2438 DragonFlyBSD hosts. It is an alias for @option{serial}.
2440 @option{path} specifies the path to the tty. @option{path} is required.
2442 @item -chardev parallel ,id=@var{id} ,path=@var{path}
2443 @itemx -chardev parport ,id=@var{id} ,path=@var{path}
2445 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2447 Connect to a local parallel port.
2449 @option{path} specifies the path to the parallel port device. @option{path} is
2452 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2454 @option{spicevmc} is only available when spice support is built in.
2456 @option{debug} debug level for spicevmc
2458 @option{name} name of spice channel to connect to
2460 Connect to a spice virtual machine channel, such as vdiport.
2462 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2464 @option{spiceport} is only available when spice support is built in.
2466 @option{debug} debug level for spicevmc
2468 @option{name} name of spice port to connect to
2470 Connect to a spice port, allowing a Spice client to handle the traffic
2471 identified by a name (preferably a fqdn).
2479 DEFHEADING(Device URL Syntax:)
2482 In addition to using normal file images for the emulated storage devices,
2483 QEMU can also use networked resources such as iSCSI devices. These are
2484 specified using a special URL syntax.
2488 iSCSI support allows QEMU to access iSCSI resources directly and use as
2489 images for the guest storage. Both disk and cdrom images are supported.
2491 Syntax for specifying iSCSI LUNs is
2492 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2494 By default qemu will use the iSCSI initiator-name
2495 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2496 line or a configuration file.
2498 Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2499 stalled requests and force a reestablishment of the session. The timeout
2500 is specified in seconds. The default is 0 which means no timeout. Libiscsi
2501 1.15.0 or greater is required for this feature.
2503 Example (without authentication):
2505 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2506 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2507 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2510 Example (CHAP username/password via URL):
2512 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2515 Example (CHAP username/password via environment variables):
2517 LIBISCSI_CHAP_USERNAME="user
" \
2518 LIBISCSI_CHAP_PASSWORD="password
" \
2519 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2522 iSCSI support is an optional feature of QEMU and only available when
2523 compiled and linked against libiscsi.
2525 DEF("iscsi
", HAS_ARG, QEMU_OPTION_iscsi,
2526 "-iscsi
[user
=user
][,password
=password
]\n"
2527 " [,header
-digest
=CRC32C|CR32C
-NONE|NONE
-CRC32C|NONE
\n"
2528 " [,initiator
-name
=initiator
-iqn
][,id
=target
-iqn
]\n"
2529 " [,timeout
=timeout
]\n"
2530 " iSCSI session parameters
\n", QEMU_ARCH_ALL)
2533 iSCSI parameters such as username and password can also be specified via
2534 a configuration file. See qemu-doc for more information and examples.
2537 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2538 as Unix Domain Sockets.
2540 Syntax for specifying a NBD device using TCP
2541 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2543 Syntax for specifying a NBD device using Unix Domain Sockets
2544 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2549 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2552 Example for Unix Domain Sockets
2554 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2558 QEMU supports SSH (Secure Shell) access to remote disks.
2562 qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2563 qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2566 Currently authentication must be done using ssh-agent. Other
2567 authentication methods may be supported in future.
2570 Sheepdog is a distributed storage system for QEMU.
2571 QEMU supports using either local sheepdog devices or remote networked
2574 Syntax for specifying a sheepdog device
2576 sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2581 qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2584 See also @url{http://http://www.osrg.net/sheepdog/}.
2587 GlusterFS is an user space distributed file system.
2588 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2589 TCP, Unix Domain Sockets and RDMA transport protocols.
2591 Syntax for specifying a VM disk image on GlusterFS volume is
2593 gluster[+transport]://[server[:port]]/volname/image[?socket=...]
2599 qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img
2602 See also @url{http://www.gluster.org}.
2604 @item HTTP/HTTPS/FTP/FTPS/TFTP
2605 QEMU supports read-only access to files accessed over http(s), ftp(s) and tftp.
2607 Syntax using a single filename:
2609 <protocol>://[<username>[:<password>]@@]<host>/<path>
2615 'http', 'https', 'ftp', 'ftps', or 'tftp'.
2618 Optional username for authentication to the remote server.
2621 Optional password for authentication to the remote server.
2624 Address of the remote server.
2627 Path on the remote server, including any query string.
2630 The following options are also supported:
2633 The full URL when passing options to the driver explicitly.
2636 The amount of data to read ahead with each range request to the remote server.
2637 This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
2638 does not have a suffix, it will be assumed to be in bytes. The value must be a
2639 multiple of 512 bytes. It defaults to 256k.
2642 Whether to verify the remote server's certificate when connecting over SSL. It
2643 can have the value 'on' or 'off'. It defaults to 'on'.
2646 Send this cookie (it can also be a list of cookies separated by ';') with
2647 each outgoing request. Only supported when using protocols such as HTTP
2648 which support cookies, otherwise ignored.
2651 Set the timeout in seconds of the CURL connection. This timeout is the time
2652 that CURL waits for a response from the remote server to get the size of the
2653 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2656 Note that when passing options to qemu explicitly, @option{driver} is the value
2659 Example: boot from a remote Fedora 20 live ISO image
2661 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
2663 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
2666 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2667 writes, copy-on-read, and a readahead of 64k
2669 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
2671 qemu
-system
-x86_64
-drive file
=/tmp
/Fedora
-x86_64
-20-20131211.1-sda
.qcow2
,copy
-on
-read
=on
2674 Example
: boot from an image stored on a VMware vSphere server with a self
-signed
2675 certificate
using a local overlay
for writes
, a readahead of
64k and a timeout
2678 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
2680 qemu
-system
-x86_64
-drive file
=/tmp
/test
.qcow2
2688 DEFHEADING(Bluetooth(R
) options
:)
2693 DEF("bt", HAS_ARG
, QEMU_OPTION_bt
, \
2694 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2695 "-bt hci,host[:id]\n" \
2696 " use host's HCI with the given name\n" \
2697 "-bt hci[,vlan=n]\n" \
2698 " emulate a standard HCI in virtual scatternet 'n'\n" \
2699 "-bt vhci[,vlan=n]\n" \
2700 " add host computer to virtual scatternet 'n' using VHCI\n" \
2701 "-bt device:dev[,vlan=n]\n" \
2702 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2707 Defines the
function of the corresponding Bluetooth HCI
. -bt options
2708 are matched with the HCIs present
in the chosen machine type
. For
2709 example when emulating a machine with only one HCI built into it
, only
2710 the first @code
{-bt hci
[...]} option is valid and defines the HCI
's
2711 logic. The Transport Layer is decided by the machine type. Currently
2712 the machines @code{n800} and @code{n810} have one HCI and all other
2716 The following three types are recognized:
2720 (default) The corresponding Bluetooth HCI assumes no internal logic
2721 and will not respond to any HCI commands or emit events.
2723 @item -bt hci,host[:@var{id}]
2724 (@code{bluez} only) The corresponding HCI passes commands / events
2725 to / from the physical HCI identified by the name @var{id} (default:
2726 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2727 capable systems like Linux.
2729 @item -bt hci[,vlan=@var{n}]
2730 Add a virtual, standard HCI that will participate in the Bluetooth
2731 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2732 VLANs, devices inside a bluetooth network @var{n} can only communicate
2733 with other devices in the same network (scatternet).
2736 @item -bt vhci[,vlan=@var{n}]
2737 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2738 to the host bluetooth stack instead of to the emulated target. This
2739 allows the host and target machines to participate in a common scatternet
2740 and communicate. Requires the Linux @code{vhci} driver installed. Can
2741 be used as following:
2744 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2747 @item -bt device:@var{dev}[,vlan=@var{n}]
2748 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2749 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2754 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2764 DEFHEADING(TPM device options:)
2766 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2767 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2768 " use path to provide path to a character device; default is /dev/tpm0\n"
2769 " use cancel-path to provide path to TPM's cancel sysfs entry
; if\n"
2770 " not provided it will be searched
for in /sys
/class/misc
/tpm?
/device
\n",
2774 The general form of a TPM device option is:
2777 @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
2779 Backend type must be:
2780 @option{passthrough}.
2782 The specific backend type will determine the applicable options.
2783 The @code{-tpmdev} option creates the TPM backend and requires a
2784 @code{-device} option that specifies the TPM frontend interface model.
2786 Options to each backend are described below.
2788 Use 'help' to print all available TPM backend types.
2793 @item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
2795 (Linux-host only) Enable access to the host's TPM using the passthrough
2798 @option{path} specifies the path to the host's TPM device, i.e., on
2799 a Linux host this would be @code{/dev/tpm0}.
2800 @option{path} is optional and by default @code{/dev/tpm0} is used.
2802 @option{cancel-path} specifies the path to the host TPM device's sysfs
2803 entry allowing for cancellation of an ongoing TPM command.
2804 @option{cancel-path} is optional and by default QEMU will search for the
2807 Some notes about using the host's TPM with the passthrough driver:
2809 The TPM device accessed by the passthrough driver must not be
2810 used by any other application on the host.
2812 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2813 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2814 TPM again and may therefore not show a TPM-specific menu that would
2815 otherwise allow the user to configure the TPM, e.g., allow the user to
2816 enable/disable or activate/deactivate the TPM.
2817 Further, if TPM ownership is released from within a VM then the host's TPM
2818 will get disabled and deactivated. To enable and activate the
2819 TPM again afterwards, the host has to be rebooted and the user is
2820 required to enter the firmware's menu to enable and activate the TPM.
2821 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2823 To create a passthrough TPM use the following two options:
2825 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2827 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2828 @code{tpmdev=tpm0} in the device option.
2838 DEFHEADING(Linux/Multiboot boot specific:)
2841 When using these options, you can use a given Linux or Multiboot
2842 kernel without installing it in the disk image. It can be useful
2843 for easier testing of various kernels.
2848 DEF("kernel
", HAS_ARG, QEMU_OPTION_kernel, \
2849 "-kernel bzImage use
'bzImage' as kernel image
\n", QEMU_ARCH_ALL)
2851 @item -kernel @var{bzImage}
2853 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2854 or in multiboot format.
2857 DEF("append
", HAS_ARG, QEMU_OPTION_append, \
2858 "-append cmdline use
'cmdline' as kernel command line
\n", QEMU_ARCH_ALL)
2860 @item -append @var{cmdline}
2862 Use @var{cmdline} as kernel command line
2865 DEF("initrd
", HAS_ARG, QEMU_OPTION_initrd, \
2866 "-initrd file use
'file' as initial ram disk
\n", QEMU_ARCH_ALL)
2868 @item -initrd @var{file}
2870 Use @var{file} as initial ram disk.
2872 @item -initrd "@
var{file1
} arg
=foo
,@
var{file2
}"
2874 This syntax is only available with multiboot.
2876 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2880 DEF("dtb
", HAS_ARG, QEMU_OPTION_dtb, \
2881 "-dtb file use
'file' as device tree image
\n", QEMU_ARCH_ALL)
2883 @item -dtb @var{file}
2885 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2894 DEFHEADING(Debug/Expert options:)
2899 DEF("fw_cfg
", HAS_ARG, QEMU_OPTION_fwcfg,
2900 "-fw_cfg
[name
=]<name
>,file
=<file
>\n"
2901 " add named fw_cfg entry with contents from file
\n"
2902 "-fw_cfg
[name
=]<name
>,string
=<str
>\n"
2903 " add named fw_cfg entry with contents from string
\n",
2907 @item -fw_cfg [name=]@var{name},file=@var{file}
2909 Add named fw_cfg entry with contents from file @var{file}.
2911 @item -fw_cfg [name=]@var{name},string=@var{str}
2912 Add named fw_cfg entry with contents from string @var{str}.
2914 The terminating NUL character of the contents of @var{str} will not be
2915 included as part of the fw_cfg item data. To insert contents with
2916 embedded NUL characters, you have to use the @var{file} parameter.
2918 The fw_cfg entries are passed by QEMU through to the guest.
2922 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
2924 creates an fw_cfg entry named opt/com.mycompany/blob with contents
2929 DEF("serial
", HAS_ARG, QEMU_OPTION_serial, \
2930 "-serial dev redirect the serial port to char device
'dev'\n",
2933 @item -serial @var{dev}
2935 Redirect the virtual serial port to host character device
2936 @var{dev}. The default device is @code{vc} in graphical mode and
2937 @code{stdio} in non graphical mode.
2939 This option can be used several times to simulate up to 4 serial
2942 Use @code{-serial none} to disable all serial ports.
2944 Available character devices are:
2946 @item vc[:@var{W}x@var{H}]
2947 Virtual console. Optionally, a width and height can be given in pixel with
2951 It is also possible to specify width or height in characters:
2956 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
2958 No device is allocated.
2961 @item chardev:@var{id}
2962 Use a named character device defined with the @code{-chardev} option.
2964 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
2965 parameters are set according to the emulated ones.
2966 @item /dev/parport@var{N}
2967 [Linux only, parallel port only] Use host parallel port
2968 @var{N}. Currently SPP and EPP parallel port features can be used.
2969 @item file:@var{filename}
2970 Write output to @var{filename}. No character can be read.
2972 [Unix only] standard input/output
2973 @item pipe:@var{filename}
2974 name pipe @var{filename}
2976 [Windows only] Use host serial port @var{n}
2977 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
2978 This implements UDP Net Console.
2979 When @var{remote_host} or @var{src_ip} are not specified
2980 they default to @code{0.0.0.0}.
2981 When not using a specified @var{src_port} a random port is automatically chosen.
2983 If you just want a simple readonly console you can use @code{netcat} or
2984 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
2985 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
2986 will appear in the netconsole session.
2988 If you plan to send characters back via netconsole or you want to stop
2989 and start QEMU a lot of times, you should have QEMU use the same
2990 source port each time by using something like @code{-serial
2991 udp::4555@@:4556} to QEMU. Another approach is to use a patched
2992 version of netcat which can listen to a TCP port and send and receive
2993 characters via udp. If you have a patched version of netcat which
2994 activates telnet remote echo and single char transfer, then you can
2995 use the following options to step up a netcat redirector to allow
2996 telnet on port 5555 to access the QEMU port.
2999 -serial udp::4555@@:4556
3000 @item netcat options:
3001 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3002 @item telnet options:
3006 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3007 The TCP Net Console has two modes of operation. It can send the serial
3008 I/O to a location or wait for a connection from a location. By default
3009 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3010 the @var{server} option QEMU will wait for a client socket application
3011 to connect to the port before continuing, unless the @code{nowait}
3012 option was specified. The @code{nodelay} option disables the Nagle buffering
3013 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3014 set, if the connection goes down it will attempt to reconnect at the
3015 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3016 one TCP connection at a time is accepted. You can use @code{telnet} to
3017 connect to the corresponding character device.
3019 @item Example to send tcp console to 192.168.0.2 port 4444
3020 -serial tcp:192.168.0.2:4444
3021 @item Example to listen and wait on port 4444 for connection
3022 -serial tcp::4444,server
3023 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3024 -serial tcp:192.168.0.100:4444,server,nowait
3027 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3028 The telnet protocol is used instead of raw tcp sockets. The options
3029 work the same as if you had specified @code{-serial tcp}. The
3030 difference is that the port acts like a telnet server or client using
3031 telnet option negotiation. This will also allow you to send the
3032 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3033 sequence. Typically in unix telnet you do it with Control-] and then
3034 type "send
break" followed by pressing the enter key.
3036 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3037 A unix domain socket is used instead of a tcp socket. The option works the
3038 same as if you had specified @code{-serial tcp} except the unix domain socket
3039 @var{path} is used for connections.
3041 @item mon:@var{dev_string}
3042 This is a special option to allow the monitor to be multiplexed onto
3043 another serial port. The monitor is accessed with key sequence of
3044 @key{Control-a} and then pressing @key{c}.
3045 @var{dev_string} should be any one of the serial devices specified
3046 above. An example to multiplex the monitor onto a telnet server
3047 listening on port 4444 would be:
3049 @item -serial mon:telnet::4444,server,nowait
3051 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3052 QEMU any more but will be passed to the guest instead.
3055 Braille device. This will use BrlAPI to display the braille output on a real
3059 Three button serial mouse. Configure the guest to use Microsoft protocol.
3063 DEF("parallel
", HAS_ARG, QEMU_OPTION_parallel, \
3064 "-parallel dev redirect the parallel port to char device
'dev'\n",
3067 @item -parallel @var{dev}
3069 Redirect the virtual parallel port to host device @var{dev} (same
3070 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3071 be used to use hardware devices connected on the corresponding host
3074 This option can be used several times to simulate up to 3 parallel
3077 Use @code{-parallel none} to disable all parallel ports.
3080 DEF("monitor
", HAS_ARG, QEMU_OPTION_monitor, \
3081 "-monitor dev redirect the monitor to char device
'dev'\n",
3084 @item -monitor @var{dev}
3086 Redirect the monitor to host device @var{dev} (same devices as the
3088 The default device is @code{vc} in graphical mode and @code{stdio} in
3090 Use @code{-monitor none} to disable the default monitor.
3092 DEF("qmp
", HAS_ARG, QEMU_OPTION_qmp, \
3093 "-qmp dev like
-monitor but opens
in 'control' mode
\n",
3096 @item -qmp @var{dev}
3098 Like -monitor but opens in 'control' mode.
3100 DEF("qmp
-pretty
", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3101 "-qmp
-pretty dev like
-qmp but uses pretty JSON formatting
\n",
3104 @item -qmp-pretty @var{dev}
3106 Like -qmp but uses pretty JSON formatting.
3109 DEF("mon
", HAS_ARG, QEMU_OPTION_mon, \
3110 "-mon
[chardev
=]name
[,mode
=readline|control
][,default]\n", QEMU_ARCH_ALL)
3112 @item -mon [chardev=]name[,mode=readline|control][,default]
3114 Setup monitor on chardev @var{name}.
3117 DEF("debugcon
", HAS_ARG, QEMU_OPTION_debugcon, \
3118 "-debugcon dev redirect the debug console to char device
'dev'\n",
3121 @item -debugcon @var{dev}
3123 Redirect the debug console to host device @var{dev} (same devices as the
3124 serial port). The debug console is an I/O port which is typically port
3125 0xe9; writing to that I/O port sends output to this device.
3126 The default device is @code{vc} in graphical mode and @code{stdio} in
3130 DEF("pidfile
", HAS_ARG, QEMU_OPTION_pidfile, \
3131 "-pidfile file write PID to
'file'\n", QEMU_ARCH_ALL)
3133 @item -pidfile @var{file}
3135 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3139 DEF("singlestep
", 0, QEMU_OPTION_singlestep, \
3140 "-singlestep always run
in singlestep mode
\n", QEMU_ARCH_ALL)
3144 Run the emulation in single step mode.
3147 DEF("S
", 0, QEMU_OPTION_S, \
3148 "-S freeze CPU at
startup (use
'c' to start execution
)\n",
3153 Do not start CPU at startup (you must type 'c' in the monitor).
3156 DEF("realtime
", HAS_ARG, QEMU_OPTION_realtime,
3157 "-realtime
[mlock
=on|off
]\n"
3158 " run qemu with realtime features
\n"
3159 " mlock
=on|off controls mlock
support (default: on
)\n",
3162 @item -realtime mlock=on|off
3164 Run qemu with realtime features.
3165 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3166 (enabled by default).
3169 DEF("gdb
", HAS_ARG, QEMU_OPTION_gdb, \
3170 "-gdb dev wait
for gdb connection on
'dev'\n", QEMU_ARCH_ALL)
3172 @item -gdb @var{dev}
3174 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3175 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3176 stdio are reasonable use case. The latter is allowing to start QEMU from
3177 within gdb and establish the connection via a pipe:
3179 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3183 DEF("s
", 0, QEMU_OPTION_s, \
3184 "-s shorthand
for -gdb tcp
::" DEFAULT_GDBSTUB_PORT "\n",
3189 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3190 (@pxref{gdb_usage}).
3193 DEF("d
", HAS_ARG, QEMU_OPTION_d, \
3194 "-d item1
,... enable logging of specified
items (use
'-d help' for a list of log items
)\n",
3197 @item -d @var{item1}[,...]
3199 Enable logging of specified items. Use '-d help' for a list of log items.
3202 DEF("D
", HAS_ARG, QEMU_OPTION_D, \
3203 "-D logfile output log to
logfile (default stderr
)\n",
3206 @item -D @var{logfile}
3208 Output log in @var{logfile} instead of to stderr
3211 DEF("dfilter
", HAS_ARG, QEMU_OPTION_DFILTER, \
3212 "-dfilter range
,.. filter debug output to range of
addresses (useful
for -d cpu
,exec
,etc
..)\n",
3215 @item -dfilter @var{range1}[,...]
3217 Filter debug output to that relevant to a range of target addresses. The filter
3218 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3219 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3220 addresses and sizes required. For example:
3222 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3224 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3225 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3226 block starting at 0xffffffc00005f000.
3229 DEF("L
", HAS_ARG, QEMU_OPTION_L, \
3230 "-L path set the directory
for the BIOS
, VGA BIOS and keymaps
\n",
3235 Set the directory for the BIOS, VGA BIOS and keymaps.
3237 To list all the data directories, use @code{-L help}.
3240 DEF("bios
", HAS_ARG, QEMU_OPTION_bios, \
3241 "-bios file set the filename
for the BIOS
\n", QEMU_ARCH_ALL)
3243 @item -bios @var{file}
3245 Set the filename for the BIOS.
3248 DEF("enable
-kvm
", 0, QEMU_OPTION_enable_kvm, \
3249 "-enable
-kvm enable KVM full virtualization support
\n", QEMU_ARCH_ALL)
3253 Enable KVM full virtualization support. This option is only available
3254 if KVM support is enabled when compiling.
3257 DEF("xen
-domid
", HAS_ARG, QEMU_OPTION_xen_domid,
3258 "-xen
-domid id specify xen guest domain id
\n", QEMU_ARCH_ALL)
3259 DEF("xen
-create
", 0, QEMU_OPTION_xen_create,
3260 "-xen
-create create domain
using xen hypercalls
, bypassing xend
\n"
3261 " warning
: should not be used when xend is
in use
\n",
3263 DEF("xen
-attach
", 0, QEMU_OPTION_xen_attach,
3264 "-xen
-attach attach to existing xen domain
\n"
3265 " xend will use
this when starting QEMU
\n",
3268 @item -xen-domid @var{id}
3270 Specify xen guest domain @var{id} (XEN only).
3273 Create domain using xen hypercalls, bypassing xend.
3274 Warning: should not be used when xend is in use (XEN only).
3277 Attach to existing xen domain.
3278 xend will use this when starting QEMU (XEN only).
3281 DEF("no
-reboot
", 0, QEMU_OPTION_no_reboot, \
3282 "-no
-reboot exit instead of rebooting
\n", QEMU_ARCH_ALL)
3286 Exit instead of rebooting.
3289 DEF("no
-shutdown
", 0, QEMU_OPTION_no_shutdown, \
3290 "-no
-shutdown stop before shutdown
\n", QEMU_ARCH_ALL)
3293 @findex -no-shutdown
3294 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3295 This allows for instance switching to monitor to commit changes to the
3299 DEF("loadvm
", HAS_ARG, QEMU_OPTION_loadvm, \
3300 "-loadvm
[tag|id
]\n" \
3301 " start right away with a saved
state (loadvm
in monitor
)\n",
3304 @item -loadvm @var{file}
3306 Start right away with a saved state (@code{loadvm} in monitor)
3310 DEF("daemonize
", 0, QEMU_OPTION_daemonize, \
3311 "-daemonize daemonize QEMU after initializing
\n", QEMU_ARCH_ALL)
3316 Daemonize the QEMU process after initialization. QEMU will not detach from
3317 standard IO until it is ready to receive connections on any of its devices.
3318 This option is a useful way for external programs to launch QEMU without having
3319 to cope with initialization race conditions.
3322 DEF("option
-rom
", HAS_ARG, QEMU_OPTION_option_rom, \
3323 "-option
-rom rom load a file
, rom
, into the option ROM space
\n",
3326 @item -option-rom @var{file}
3328 Load the contents of @var{file} as an option ROM.
3329 This option is useful to load things like EtherBoot.
3332 HXCOMM Silently ignored for compatibility
3333 DEF("clock
", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3335 HXCOMM Options deprecated by -rtc
3336 DEF("localtime
", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3337 DEF("startdate
", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3339 DEF("rtc
", HAS_ARG, QEMU_OPTION_rtc, \
3340 "-rtc
[base
=utc|localtime|date
][,clock
=host|rt|vm
][,driftfix
=none|slew
]\n" \
3341 " set the RTC base and clock
, enable drift fix
for clock
ticks (x86 only
)\n",
3346 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3348 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3349 UTC or local time, respectively. @code{localtime} is required for correct date in
3350 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3351 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3353 By default the RTC is driven by the host system time. This allows using of the
3354 RTC as accurate reference clock inside the guest, specifically if the host
3355 time is smoothly following an accurate external reference clock, e.g. via NTP.
3356 If you want to isolate the guest time from the host, you can set @option{clock}
3357 to @code{rt} instead. To even prevent it from progressing during suspension,
3358 you can set it to @code{vm}.
3360 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3361 specifically with Windows' ACPI HAL. This option will try to figure out how
3362 many timer interrupts were not processed by the Windows guest and will
3366 DEF("icount
", HAS_ARG, QEMU_OPTION_icount, \
3367 "-icount
[shift
=N|auto
][,align
=on|off
][,sleep
=on|off
,rr
=record|replay
,rrfile
=<filename
>]\n" \
3368 " enable virtual instruction counter with
2^N clock ticks per
\n" \
3369 " instruction
, enable aligning the host and virtual clocks
\n" \
3370 " or disable real time cpu sleeping
\n", QEMU_ARCH_ALL)
3372 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename}]
3374 Enable virtual instruction counter. The virtual cpu will execute one
3375 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3376 then the virtual cpu speed will be automatically adjusted to keep virtual
3377 time within a few seconds of real time.
3379 When the virtual cpu is sleeping, the virtual time will advance at default
3380 speed unless @option{sleep=on|off} is specified.
3381 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3382 instantly whenever the virtual cpu goes to sleep mode and will not advance
3383 if no timer is enabled. This behavior give deterministic execution times from
3384 the guest point of view.
3386 Note that while this option can give deterministic behavior, it does not
3387 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3388 order cores with complex cache hierarchies. The number of instructions
3389 executed often has little or no correlation with actual performance.
3391 @option{align=on} will activate the delay algorithm which will try
3392 to synchronise the host clock and the virtual clock. The goal is to
3393 have a guest running at the real frequency imposed by the shift option.
3394 Whenever the guest clock is behind the host clock and if
3395 @option{align=on} is specified then we print a message to the user
3396 to inform about the delay.
3397 Currently this option does not work when @option{shift} is @code{auto}.
3398 Note: The sync algorithm will work for those shift values for which
3399 the guest clock runs ahead of the host clock. Typically this happens
3400 when the shift value is high (how high depends on the host machine).
3402 When @option{rr} option is specified deterministic record/replay is enabled.
3403 Replay log is written into @var{filename} file in record mode and
3404 read from this file in replay mode.
3407 DEF("watchdog
", HAS_ARG, QEMU_OPTION_watchdog, \
3408 "-watchdog model
\n" \
3409 " enable virtual hardware watchdog
[default=none
]\n",
3412 @item -watchdog @var{model}
3414 Create a virtual hardware watchdog device. Once enabled (by a guest
3415 action), the watchdog must be periodically polled by an agent inside
3416 the guest or else the guest will be restarted. Choose a model for
3417 which your guest has drivers.
3419 The @var{model} is the model of hardware watchdog to emulate. Use
3420 @code{-watchdog help} to list available hardware models. Only one
3421 watchdog can be enabled for a guest.
3423 The following models may be available:
3426 iBASE 700 is a very simple ISA watchdog with a single timer.
3428 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3429 dual-timer watchdog.
3431 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3432 (currently KVM only).
3436 DEF("watchdog
-action
", HAS_ARG, QEMU_OPTION_watchdog_action, \
3437 "-watchdog
-action reset|shutdown|poweroff|pause|debug|none
\n" \
3438 " action when watchdog fires
[default=reset
]\n",
3441 @item -watchdog-action @var{action}
3442 @findex -watchdog-action
3444 The @var{action} controls what QEMU will do when the watchdog timer
3447 @code{reset} (forcefully reset the guest).
3448 Other possible actions are:
3449 @code{shutdown} (attempt to gracefully shutdown the guest),
3450 @code{poweroff} (forcefully poweroff the guest),
3451 @code{pause} (pause the guest),
3452 @code{debug} (print a debug message and continue), or
3453 @code{none} (do nothing).
3455 Note that the @code{shutdown} action requires that the guest responds
3456 to ACPI signals, which it may not be able to do in the sort of
3457 situations where the watchdog would have expired, and thus
3458 @code{-watchdog-action shutdown} is not recommended for production use.
3463 @item -watchdog i6300esb -watchdog-action pause
3464 @itemx -watchdog ib700
3468 DEF("echr
", HAS_ARG, QEMU_OPTION_echr, \
3469 "-echr chr set terminal escape character instead of ctrl
-a
\n",
3473 @item -echr @var{numeric_ascii_value}
3475 Change the escape character used for switching to the monitor when using
3476 monitor and serial sharing. The default is @code{0x01} when using the
3477 @code{-nographic} option. @code{0x01} is equal to pressing
3478 @code{Control-a}. You can select a different character from the ascii
3479 control keys where 1 through 26 map to Control-a through Control-z. For
3480 instance you could use the either of the following to change the escape
3481 character to Control-t.
3488 DEF("virtioconsole
", HAS_ARG, QEMU_OPTION_virtiocon, \
3489 "-virtioconsole c
\n" \
3490 " set virtio console
\n", QEMU_ARCH_ALL)
3492 @item -virtioconsole @var{c}
3493 @findex -virtioconsole
3496 This option is maintained for backward compatibility.
3498 Please use @code{-device virtconsole} for the new way of invocation.
3501 DEF("show
-cursor
", 0, QEMU_OPTION_show_cursor, \
3502 "-show
-cursor show cursor
\n", QEMU_ARCH_ALL)
3505 @findex -show-cursor
3509 DEF("tb
-size
", HAS_ARG, QEMU_OPTION_tb_size, \
3510 "-tb
-size n set TB size
\n", QEMU_ARCH_ALL)
3512 @item -tb-size @var{n}
3517 DEF("incoming
", HAS_ARG, QEMU_OPTION_incoming, \
3518 "-incoming tcp
:[host
]:port
[,to
=maxport
][,ipv4
][,ipv6
]\n" \
3519 "-incoming rdma
:host
:port
[,ipv4
][,ipv6
]\n" \
3520 "-incoming unix
:socketpath
\n" \
3521 " prepare
for incoming migration
, listen on
\n" \
3522 " specified protocol and socket address
\n" \
3523 "-incoming fd
:fd
\n" \
3524 "-incoming exec
:cmdline
\n" \
3525 " accept incoming migration on given file descriptor
\n" \
3526 " or from given external command
\n" \
3527 "-incoming defer
\n" \
3528 " wait
for the URI to be specified via migrate_incoming
\n",
3531 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3532 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3534 Prepare for incoming migration, listen on a given tcp port.
3536 @item -incoming unix:@var{socketpath}
3537 Prepare for incoming migration, listen on a given unix socket.
3539 @item -incoming fd:@var{fd}
3540 Accept incoming migration from a given filedescriptor.
3542 @item -incoming exec:@var{cmdline}
3543 Accept incoming migration as an output from specified external command.
3545 @item -incoming defer
3546 Wait for the URI to be specified via migrate_incoming. The monitor can
3547 be used to change settings (such as migration parameters) prior to issuing
3548 the migrate_incoming to allow the migration to begin.
3551 DEF("nodefaults
", 0, QEMU_OPTION_nodefaults, \
3552 "-nodefaults don
't create default devices\n", QEMU_ARCH_ALL)
3556 Don't create
default devices
. Normally
, QEMU sets the
default devices like serial
3557 port
, parallel port
, virtual console
, monitor device
, VGA adapter
, floppy and
3558 CD
-ROM drive and others
. The @code
{-nodefaults
} option will disable all those
3563 DEF("chroot", HAS_ARG
, QEMU_OPTION_chroot
, \
3564 "-chroot dir chroot to dir just before starting the VM\n",
3568 @item
-chroot @
var{dir
}
3570 Immediately before starting guest execution
, chroot to the specified
3571 directory
. Especially useful
in combination with
-runas
.
3575 DEF("runas", HAS_ARG
, QEMU_OPTION_runas
, \
3576 "-runas user change to user id user just before starting the VM\n",
3580 @item
-runas @
var{user
}
3582 Immediately before starting guest execution
, drop root privileges
, switching
3583 to the specified user
.
3586 DEF("prom-env", HAS_ARG
, QEMU_OPTION_prom_env
,
3587 "-prom-env variable=value\n"
3588 " set OpenBIOS nvram variables\n",
3589 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
3591 @item
-prom
-env @
var{variable
}=@
var{value
}
3593 Set OpenBIOS nvram @
var{variable
} to given @
var{value
} (PPC
, SPARC only
).
3595 DEF("semihosting", 0, QEMU_OPTION_semihosting
,
3596 "-semihosting semihosting mode\n",
3597 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3601 @findex
-semihosting
3602 Enable semihosting
mode (ARM
, M68K
, Xtensa
, MIPS only
).
3604 DEF("semihosting-config", HAS_ARG
, QEMU_OPTION_semihosting_config
,
3605 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3606 " semihosting configuration\n",
3607 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3610 @item
-semihosting
-config
[enable
=on|off
][,target
=native|gdb|auto
][,arg
=str
[,...]]
3611 @findex
-semihosting
-config
3612 Enable and configure
semihosting (ARM
, M68K
, Xtensa
, MIPS only
).
3614 @item target
=@code
{native|gdb|auto
}
3615 Defines where the semihosting calls will be addressed
, to
QEMU (@code
{native
})
3616 or to
GDB (@code
{gdb
}). The
default is @code
{auto
}, which means @code
{gdb
}
3617 during debug sessions and @code
{native
} otherwise
.
3618 @item arg
=@
var{str1
},arg
=@
var{str2
},...
3619 Allows the user to pass input arguments
, and can be used multiple times to build
3620 up a list
. The old
-style @code
{-kernel
}/@code
{-append
} method of passing a
3621 command line is still supported
for backward compatibility
. If both the
3622 @code
{--semihosting
-config arg
} and the @code
{-kernel
}/@code
{-append
} are
3623 specified
, the former is passed to semihosting as it always takes precedence
.
3626 DEF("old-param", 0, QEMU_OPTION_old_param
,
3627 "-old-param old param mode\n", QEMU_ARCH_ARM
)
3630 @findex
-old
-param (ARM
)
3631 Old param
mode (ARM only
).
3634 DEF("sandbox", HAS_ARG
, QEMU_OPTION_sandbox
, \
3635 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n",
3638 @item
-sandbox @
var{arg
}
3640 Enable Seccomp mode
2 system call filter
. 'on' will enable syscall filtering and
'off' will
3641 disable it
. The
default is
'off'.
3644 DEF("readconfig", HAS_ARG
, QEMU_OPTION_readconfig
,
3645 "-readconfig <file>\n", QEMU_ARCH_ALL
)
3647 @item
-readconfig @
var{file
}
3649 Read device configuration from @
var{file
}. This approach is useful when you want to spawn
3650 QEMU process with many command line options but you don
't want to exceed the command line
3653 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3654 "-writeconfig <file>\n"
3655 " read/write config file\n", QEMU_ARCH_ALL)
3657 @item -writeconfig @var{file}
3658 @findex -writeconfig
3659 Write device configuration to @var{file}. The @var{file} can be either filename to save
3660 command line and device configuration into file or dash @code{-}) character to print the
3661 output to stdout. This can be later used as input file for @code{-readconfig} option.
3663 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
3665 " do not load default config files at startup\n",
3669 @findex -nodefconfig
3670 Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
3671 The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
3673 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3675 " do not load user-provided config files at startup\n",
3678 @item -no-user-config
3679 @findex -no-user-config
3680 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3681 config files on @var{sysconfdir}, but won't make it skip the QEMU
-provided config
3682 files from @
var{datadir
}.
3684 DEF("trace", HAS_ARG
, QEMU_OPTION_trace
,
3685 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3686 " specify tracing options\n",
3689 HXCOMM This line is not accurate
, as some sub
-options are backend
-specific but
3690 HXCOMM HX does not support conditional compilation of text
.
3691 @item
-trace [[enable
=]@
var{pattern
}][,events
=@
var{file
}][,file
=@
var{file
}]
3693 @include qemu
-option
-trace.texi
3697 DEF("qtest", HAS_ARG
, QEMU_OPTION_qtest
, "", QEMU_ARCH_ALL
)
3698 DEF("qtest-log", HAS_ARG
, QEMU_OPTION_qtest_log
, "", QEMU_ARCH_ALL
)
3701 DEF("enable-fips", 0, QEMU_OPTION_enablefips
,
3702 "-enable-fips enable FIPS 140-2 compliance\n",
3707 @findex
-enable
-fips
3708 Enable FIPS
140-2 compliance mode
.
3711 HXCOMM Deprecated by
-machine accel
=tcg property
3712 DEF("no-kvm", 0, QEMU_OPTION_no_kvm
, "", QEMU_ARCH_I386
)
3714 HXCOMM Deprecated by kvm
-pit driver properties
3715 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection
,
3718 HXCOMM
Deprecated (ignored
)
3719 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit
, "", QEMU_ARCH_I386
)
3721 HXCOMM Deprecated by
-machine kernel_irqchip
=on|off property
3722 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip
, "", QEMU_ARCH_I386
)
3724 HXCOMM
Deprecated (ignored
)
3725 DEF("tdf", 0, QEMU_OPTION_tdf
,"", QEMU_ARCH_ALL
)
3727 DEF("msg", HAS_ARG
, QEMU_OPTION_msg
,
3728 "-msg timestamp[=on|off]\n"
3729 " change the format of messages\n"
3730 " on|off controls leading timestamps (default:on)\n",
3733 @item
-msg timestamp
[=on|off
]
3735 prepend a timestamp to each log message
.(default:on
)
3738 DEF("dump-vmstate", HAS_ARG
, QEMU_OPTION_dump_vmstate
,
3739 "-dump-vmstate <file>\n"
3740 " Output vmstate information in JSON format to file.\n"
3741 " Use the scripts/vmstate-static-checker.py file to\n"
3742 " check for possible regressions in migration code\n"
3743 " by comparing two such vmstate dumps.\n",
3746 @item
-dump
-vmstate @
var{file
}
3747 @findex
-dump
-vmstate
3748 Dump json
-encoded vmstate information
for current machine type to file
3752 DEFHEADING(Generic object creation
)
3754 DEF("object", HAS_ARG
, QEMU_OPTION_object
,
3755 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3756 " create a new object of type TYPENAME setting properties\n"
3757 " in the order they are specified. Note that the 'id'\n"
3758 " property must be set. These objects are placed in the\n"
3759 " '/objects' path.\n",
3762 @item
-object @
var{typename
}[,@
var{prop1
}=@
var{value1
},...]
3764 Create a
new object of type @
var{typename
} setting properties
3765 in the order they are specified
. Note that the
'id'
3766 property must be set
. These objects are placed
in the
3771 @item
-object memory
-backend
-file
,id
=@
var{id
},size
=@
var{size
},mem
-path
=@
var{dir
},share
=@
var{on|off
}
3773 Creates a memory file backend object
, which can be used to back
3774 the guest RAM with huge pages
. The @option
{id
} parameter is a
3775 unique ID that will be used to reference
this memory region
3776 when configuring the @option
{-numa
} argument
. The @option
{size
}
3777 option provides the size of the memory region
, and accepts
3778 common suffixes
, eg @option
{500M
}. The @option
{mem
-path
} provides
3779 the path to either a shared memory or huge page filesystem mount
.
3780 The @option
{share
} boolean option determines whether the memory
3781 region is marked as
private to QEMU
, or shared
. The latter allows
3782 a co
-operating external process to access the QEMU memory region
.
3784 @item
-object rng
-random
,id
=@
var{id
},filename
=@
var{/dev
/random
}
3786 Creates a random number generator backend which obtains entropy from
3787 a device on the host
. The @option
{id
} parameter is a unique ID that
3788 will be used to reference
this entropy backend from the @option
{virtio
-rng
}
3789 device
. The @option
{filename
} parameter specifies which file to obtain
3790 entropy from and
if omitted defaults to @option
{/dev
/random
}.
3792 @item
-object rng
-egd
,id
=@
var{id
},chardev
=@
var{chardevid
}
3794 Creates a random number generator backend which obtains entropy from
3795 an external daemon running on the host
. The @option
{id
} parameter is
3796 a unique ID that will be used to reference
this entropy backend from
3797 the @option
{virtio
-rng
} device
. The @option
{chardev
} parameter is
3798 the unique ID of a character device backend that provides the connection
3801 @item
-object tls
-creds
-anon
,id
=@
var{id
},endpoint
=@
var{endpoint
},dir
=@
var{/path
/to
/cred
/dir
},verify
-peer
=@
var{on|off
}
3803 Creates a TLS anonymous credentials object
, which can be used to provide
3804 TLS support on network backends
. The @option
{id
} parameter is a unique
3805 ID which network backends will use to access the credentials
. The
3806 @option
{endpoint
} is either @option
{server
} or @option
{client
} depending
3807 on whether the QEMU network backend that uses the credentials will be
3808 acting as a client or as a server
. If @option
{verify
-peer
} is enabled
3809 (the
default) then once the handshake is completed
, the peer credentials
3810 will be verified
, though
this is a no
-op
for anonymous credentials
.
3812 The @
var{dir
} parameter tells QEMU where to find the credential
3813 files
. For server endpoints
, this directory may contain a file
3814 @
var{dh
-params
.pem
} providing diffie
-hellman parameters to use
3815 for the TLS server
. If the file is missing
, QEMU will generate
3816 a set of DH parameters at startup
. This is a computationally
3817 expensive operation that consumes random pool entropy
, so it is
3818 recommended that a persistent set of parameters be generated
3821 @item
-object tls
-creds
-x509
,id
=@
var{id
},endpoint
=@
var{endpoint
},dir
=@
var{/path
/to
/cred
/dir
},verify
-peer
=@
var{on|off
},passwordid
=@
var{id
}
3823 Creates a TLS anonymous credentials object
, which can be used to provide
3824 TLS support on network backends
. The @option
{id
} parameter is a unique
3825 ID which network backends will use to access the credentials
. The
3826 @option
{endpoint
} is either @option
{server
} or @option
{client
} depending
3827 on whether the QEMU network backend that uses the credentials will be
3828 acting as a client or as a server
. If @option
{verify
-peer
} is enabled
3829 (the
default) then once the handshake is completed
, the peer credentials
3830 will be verified
. With x509 certificates
, this implies that the clients
3831 must be provided with valid client certificates too
.
3833 The @
var{dir
} parameter tells QEMU where to find the credential
3834 files
. For server endpoints
, this directory may contain a file
3835 @
var{dh
-params
.pem
} providing diffie
-hellman parameters to use
3836 for the TLS server
. If the file is missing
, QEMU will generate
3837 a set of DH parameters at startup
. This is a computationally
3838 expensive operation that consumes random pool entropy
, so it is
3839 recommended that a persistent set of parameters be generated
3842 For x509 certificate credentials the directory will contain further files
3843 providing the x509 certificates
. The certificates must be stored
3844 in PEM format
, in filenames @
var{ca
-cert
.pem
}, @
var{ca
-crl
.pem
} (optional
),
3845 @
var{server
-cert
.pem
} (only servers
), @
var{server
-key
.pem
} (only servers
),
3846 @
var{client
-cert
.pem
} (only clients
), and @
var{client
-key
.pem
} (only clients
).
3848 For the @
var{server
-key
.pem
} and @
var{client
-key
.pem
} files which
3849 contain sensitive
private keys
, it is possible to use an encrypted
3850 version by providing the @
var{passwordid
} parameter
. This provides
3851 the ID of a previously created @code
{secret
} object containing the
3852 password
for decryption
.
3854 @item
-object filter
-buffer
,id
=@
var{id
},netdev
=@
var{netdevid
},interval
=@
var{t
}[,queue
=@
var{all|rx|tx
}][,status
=@
var{on|off
}]
3856 Interval @
var{t
} can
't be 0, this filter batches the packet delivery: all
3857 packets arriving in a given interval on netdev @var{netdevid} are delayed
3858 until the end of the interval. Interval is in microseconds.
3859 @option{status} is optional that indicate whether the netfilter is
3860 on (enabled) or off (disabled), the default status for netfilter will be 'on
'.
3862 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
3864 @option{all}: the filter is attached both to the receive and the transmit
3865 queue of the netdev (default).
3867 @option{rx}: the filter is attached to the receive queue of the netdev,
3868 where it will receive packets sent to the netdev.
3870 @option{tx}: the filter is attached to the transmit queue of the netdev,
3871 where it will receive packets sent by the netdev.
3873 @item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
3875 filter-mirror on netdev @var{netdevid},mirror net packet to chardev
3878 @item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},
3879 outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
3881 filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
3882 @
var{chardevid
},and redirect indev
's packet to filter.
3883 Create a filter-redirector we need to differ outdev id from indev id, id can not
3884 be the same. we can just use indev or outdev, but at least one of indev or outdev
3885 need to be specified.
3887 @item -object filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}]
3889 Dump the network traffic on netdev @var{dev} to the file specified by
3890 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
3891 The file format is libpcap, so it can be analyzed with tools such as tcpdump
3894 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
3895 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
3897 Defines a secret to store a password, encryption key, or some other sensitive
3898 data. The sensitive data can either be passed directly via the @var{data}
3899 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
3900 parameter is insecure unless the sensitive data is encrypted.
3902 The sensitive data can be provided in raw format (the default), or base64.
3903 When encoded as JSON, the raw format only supports valid UTF-8 characters,
3904 so base64 is recommended for sending binary data. QEMU will convert from
3905 which ever format is provided to the format it needs internally. eg, an
3906 RBD password can be provided in raw format, even though it will be base64
3907 encoded when passed onto the RBD sever.
3909 For added protection, it is possible to encrypt the data associated with
3910 a secret using the AES-256-CBC cipher. Use of encryption is indicated
3911 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
3912 parameter provides the ID of a previously defined secret that contains
3913 the AES-256 decryption key. This key should be 32-bytes long and be
3914 base64 encoded. The @var{iv} parameter provides the random initialization
3915 vector used for encryption of this particular secret and should be a
3916 base64 encrypted string of the 16-byte IV.
3918 The simplest (insecure) usage is to provide the secret inline
3922 # $QEMU -object secret,id=sec0,data=letmein,format=raw
3926 The simplest secure usage is to provide the secret via a file
3928 # echo -n "letmein" > mypasswd.txt
3929 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
3931 For greater security, AES-256-CBC should be used. To illustrate usage,
3932 consider the openssl command line tool which can encrypt the data. Note
3933 that when encrypting, the plaintext must be padded to the cipher block
3934 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
3936 First a master key needs to be created in base64 encoding:
3939 # openssl rand -base64 32 > key.b64
3940 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
3943 Each secret to be encrypted needs to have a random initialization vector
3944 generated. These do not need to be kept secret
3947 # openssl rand -base64 16 > iv.b64
3948 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
3951 The secret to be defined can now be encrypted, in this case we're
3952 telling openssl to base64 encode the result
, but it could be left
3953 as raw bytes
if desired
.
3956 # SECRET
=$
(echo
-n
"letmein" |
3957 openssl enc
-aes
-256-cbc
-a
-K $KEY
-iv $IV
)
3960 When launching QEMU
, create a master secret pointing to @code
{key
.b64
}
3961 and specify that to be used to decrypt the user password
. Pass the
3962 contents of @code
{iv
.b64
} to the second secret
3966 -object secret
,id
=secmaster0
,format
=base64
,file
=key
.b64 \
3967 -object secret
,id
=sec0
,keyid
=secmaster0
,format
=base64
,\
3968 data
=$SECRET
,iv
=$
(<iv
.b64
)
3976 HXCOMM This is the last statement
. Insert
new options before
this line
!