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\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 " iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n"
42 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
43 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
44 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
45 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n",
48 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
50 Select the emulated machine by @
var{name
}. Use @code
{-machine help
} to list
51 available machines
. Supported machine properties are
:
53 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
54 This is used to enable an accelerator
. Depending on the target architecture
,
55 kvm
, xen
, or tcg can be available
. By
default, tcg is used
. If there is more
56 than one accelerator specified
, the next one is used
if the previous one fails
58 @item kernel_irqchip
=on|off
59 Controls
in-kernel irqchip support
for the chosen accelerator when available
.
60 @item gfx_passthru
=on|off
61 Enables IGD GFX passthrough support
for the chosen machine when available
.
62 @item vmport
=on|off|auto
63 Enables emulation of VMWare IO port
, for vmmouse etc
. auto says to select the
64 value based on accel
. For accel
=xen the
default is off otherwise the
default
66 @item kvm_shadow_mem
=size
67 Defines the size of the KVM shadow MMU
.
68 @item dump
-guest
-core
=on|off
69 Include guest memory
in a core dump
. The
default is on
.
70 @item mem
-merge
=on|off
71 Enables or disables memory merge support
. This feature
, when supported by
72 the host
, de
-duplicates identical memory pages among VMs instances
75 Enables or disables emulated Intel
IOMMU (VT
-d
) support
. The
default is off
.
76 @item aes
-key
-wrap
=on|off
77 Enables or disables AES key wrapping support on s390
-ccw hosts
. This feature
78 controls whether AES wrapping keys will be created to allow
79 execution of AES cryptographic functions
. The
default is on
.
80 @item dea
-key
-wrap
=on|off
81 Enables or disables DEA key wrapping support on s390
-ccw hosts
. This feature
82 controls whether DEA wrapping keys will be created to allow
83 execution of DEA cryptographic functions
. The
default is on
.
87 HXCOMM Deprecated by
-machine
88 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
90 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
91 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
93 @item
-cpu @
var{model
}
95 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
98 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
99 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
100 " set the number of CPUs to 'n' [default=1]\n"
101 " maxcpus= maximum number of total cpus, including\n"
102 " offline CPUs for hotplug, etc\n"
103 " cores= number of CPU cores on one socket\n"
104 " threads= number of threads on one CPU core\n"
105 " sockets= number of discrete sockets in the system\n",
108 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
110 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
111 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
113 For the PC target
, the number of @
var{cores
} per socket
, the number
114 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
115 specified
. Missing values will be computed
. If any on the three values is
116 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
117 specifies the maximum number of hotpluggable CPUs
.
120 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
121 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n"
122 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL
)
124 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
125 @itemx
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{cpu
[-cpu
]}][,nodeid
=@
var{node
}]
127 Simulate a multi node NUMA system
. If @samp
{mem
}, @samp
{memdev
}
128 and @samp
{cpus
} are omitted
, resources are split equally
. Also
, note
129 that the
-@option
{numa
} option doesn
't allocate any of the specified
130 resources. That is, it just assigns existing resources to NUMA nodes. This
131 means that one still has to use the @option{-m}, @option{-smp} options
132 to allocate RAM and VCPUs respectively, and possibly @option{-object}
133 to specify the memory backend for the @samp{memdev} suboption.
135 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
136 node uses @samp{memdev}, all of them have to use it.
139 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
140 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
141 " Add 'fd
' to fd 'set
'\n", QEMU_ARCH_ALL)
143 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
146 Add a file descriptor to an fd set. Valid options are:
150 This option defines the file descriptor of which a duplicate is added to fd set.
151 The file descriptor cannot be stdin, stdout, or stderr.
153 This option defines the ID of the fd set to add the file descriptor to.
154 @item opaque=@var{opaque}
155 This option defines a free-form string that can be used to describe @var{fd}.
158 You can open an image using pre-opened file descriptors from an fd set:
161 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
162 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
163 -drive file=/dev/fdset/2,index=0,media=disk
167 DEF("set", HAS_ARG, QEMU_OPTION_set,
168 "-set group.id.arg=value\n"
169 " set <arg> parameter for item <id> of type <group>\n"
170 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
172 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
174 Set parameter @var{arg} for item @var{id} of type @var{group}\n"
177 DEF("global", HAS_ARG, QEMU_OPTION_global,
178 "-global driver.property=value\n"
179 "-global driver=driver,property=property,value=value\n"
180 " set a global default for a driver property\n",
183 @item -global @var{driver}.@var{prop}=@var{value}
184 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
186 Set default value of @var{driver}'s property @
var{prop
} to @
var{value
}, e
.g
.:
189 qemu
-system
-i386
-global ide
-drive
.physical_block_size
=4096 -drive file
=file
,if=ide
,index
=0,media
=disk
192 In particular
, you can use
this to set driver properties
for devices which are
193 created automatically by the machine model
. To create a device which is not
194 created automatically and set properties on it
, use
-@option
{device
}.
196 -global @
var{driver
}.@
var{prop
}=@
var{value
} is shorthand
for -global
197 driver
=@
var{driver
},property
=@
var{prop
},value
=@
var{value
}. The
198 longhand syntax works even when @
var{driver
} contains a dot
.
201 DEF("boot", HAS_ARG
, QEMU_OPTION_boot
,
202 "-boot [order=drives][,once=drives][,menu=on|off]\n"
203 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
204 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
205 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
206 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
207 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
210 @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
]
212 Specify boot order @
var{drives
} as a string of drive letters
. Valid
213 drive letters depend on the target architecture
. The x86 PC uses
: a
, b
214 (floppy
1 and
2), c (first hard disk
), d (first CD
-ROM
), n
-p (Etherboot
215 from network adapter
1-4), hard disk boot is the
default. To apply a
216 particular boot order only on the first startup
, specify it via
219 Interactive boot menus
/prompts can be enabled via @option
{menu
=on
} as far
220 as firmware
/BIOS supports them
. The
default is non
-interactive boot
.
222 A splash picture could be passed to bios
, enabling user to show it as logo
,
223 when option splash
=@
var{sp_name
} is given and menu
=on
, If firmware
/BIOS
224 supports them
. Currently Seabios
for X86 system support it
.
225 limitation
: The splash file could be a jpeg file or a BMP file
in 24 BPP
226 format(true color
). The resolution should be supported by the SVGA mode
, so
227 the recommended is
320x240
, 640x480
, 800x640
.
229 A timeout could be passed to bios
, guest will pause
for @
var{rb_timeout
} ms
230 when boot failed
, then reboot
. If @
var{rb_timeout
} is
'-1', guest will not
231 reboot
, qemu passes
'-1' to bios by
default. Currently Seabios
for X86
234 Do strict boot via @option
{strict
=on
} as far as firmware
/BIOS
235 supports it
. This only effects when boot priority is changed by
236 bootindex options
. The
default is non
-strict boot
.
239 #
try to boot from network first
, then from hard disk
240 qemu
-system
-i386
-boot order
=nc
241 # boot from CD
-ROM first
, switch back to
default order after reboot
242 qemu
-system
-i386
-boot once
=d
243 # boot with a splash picture
for 5 seconds
.
244 qemu
-system
-i386
-boot menu
=on
,splash
=/root
/boot
.bmp
,splash
-time
=5000
247 Note
: The legacy format
'-boot @var{drives}' is still supported but its
248 use is discouraged as it may be removed from future versions
.
251 DEF("m", HAS_ARG
, QEMU_OPTION_m
,
252 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
253 " configure guest RAM\n"
254 " size: initial amount of guest memory\n"
255 " slots: number of hotplug slots (default: none)\n"
256 " maxmem: maximum amount of guest memory (default: none)\n"
257 "NOTE: Some architectures might enforce a specific granularity\n",
260 @item
-m
[size
=]@
var{megs
}[,slots
=n
,maxmem
=size
]
262 Sets guest startup RAM size to @
var{megs
} megabytes
. Default is
128 MiB
.
263 Optionally
, a suffix of ``M
'' or ``G
'' can be used to signify a value
in
264 megabytes or gigabytes respectively
. Optional pair @
var{slots
}, @
var{maxmem
}
265 could be used to set amount of hotpluggable memory slots and maximum amount of
266 memory
. Note that @
var{maxmem
} must be aligned to the page size
.
268 For example
, the following command
-line sets the guest startup RAM size to
269 1GB
, creates
3 slots to hotplug additional memory and sets the maximum
270 memory the guest can reach to
4GB
:
273 qemu
-system
-x86_64
-m
1G
,slots
=3,maxmem
=4G
276 If @
var{slots
} and @
var{maxmem
} are not specified
, memory hotplug won
't
277 be enabled and the guest startup RAM will never increase.
280 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
281 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
283 @item -mem-path @var{path}
285 Allocate guest RAM from a temporarily created file in @var{path}.
288 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
289 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
293 @findex -mem-prealloc
294 Preallocate memory when using -mem-path.
297 DEF("k", HAS_ARG, QEMU_OPTION_k,
298 "-k language use keyboard layout (for example 'fr
' for French)\n",
301 @item -k @var{language}
303 Use keyboard layout @var{language} (for example @code{fr} for
304 French). This option is only needed where it is not easy to get raw PC
305 keycodes (e.g. on Macs, with some X11 servers or with a VNC
306 display). You don't normally need to use it on PC
/Linux or PC
/Windows
309 The available layouts are
:
311 ar de
-ch es fo fr
-ca hu ja mk no pt
-br sv
312 da en
-gb et fr fr
-ch is lt nl pl ru th
313 de en
-us fi fr
-be hr it lv nl
-be pt sl tr
316 The
default is @code
{en
-us
}.
320 DEF("audio-help", 0, QEMU_OPTION_audio_help
,
321 "-audio-help print list of audio drivers and their options\n",
326 Will show the audio subsystem help
: list of drivers
, tunable
330 DEF("soundhw", HAS_ARG
, QEMU_OPTION_soundhw
,
331 "-soundhw c1,... enable audio support\n"
332 " and only specified sound cards (comma separated list)\n"
333 " use '-soundhw help' to get the list of supported cards\n"
334 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL
)
336 @item
-soundhw @
var{card1
}[,@
var{card2
},...] or
-soundhw all
338 Enable audio and selected sound hardware
. Use
'help' to print all
339 available sound hardware
.
342 qemu
-system
-i386
-soundhw sb16
,adlib disk
.img
343 qemu
-system
-i386
-soundhw es1370 disk
.img
344 qemu
-system
-i386
-soundhw ac97 disk
.img
345 qemu
-system
-i386
-soundhw hda disk
.img
346 qemu
-system
-i386
-soundhw all disk
.img
347 qemu
-system
-i386
-soundhw help
350 Note that Linux
's i810_audio OSS kernel (for AC97) module might
351 require manually specifying clocking.
354 modprobe i810_audio clocking=48000
358 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
359 "-balloon none disable balloon device\n"
360 "-balloon virtio[,addr=str]\n"
361 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
365 Disable balloon device.
366 @item -balloon virtio[,addr=@var{addr}]
367 Enable virtio balloon device (default), optionally with PCI address
371 DEF("device", HAS_ARG, QEMU_OPTION_device,
372 "-device driver[,prop[=value][,...]]\n"
373 " add device (based on driver)\n"
374 " prop=value,... sets driver properties\n"
375 " use '-device help
' to print all possible drivers\n"
376 " use '-device driver
,help
' to print all possible properties\n",
379 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
381 Add device @var{driver}. @var{prop}=@var{value} sets driver
382 properties. Valid properties depend on the driver. To get help on
383 possible drivers and properties, use @code{-device help} and
384 @code{-device @var{driver},help}.
387 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}]
389 Add an IPMI BMC. This is a simulation of a hardware management
390 interface processor that normally sits on a system. It provides
391 a watchdog and the ability to reset and power control the system.
392 You need to connect this to an IPMI interface to make it useful
394 The IPMI slave address to use for the BMC. The default is 0x20.
395 This address is the BMC's address on the I2C network of management
396 controllers
. If you don
't know what this means, it is safe to ignore
399 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
401 Add a connection to an external IPMI BMC simulator. Instead of
402 locally emulating the BMC like the above item, instead connect
403 to an external entity that provides the IPMI services.
405 A connection is made to an external BMC simulator. If you do this, it
406 is strongly recommended that you use the "reconnect=" chardev option
407 to reconnect to the simulator if the connection is lost. Note that if
408 this is not used carefully, it can be a security issue, as the
409 interface has the ability to send resets, NMIs, and power off the VM.
410 It's best
if QEMU makes a connection to an external simulator running
411 on a secure port on localhost
, so neither the simulator nor QEMU is
412 exposed to any outside network
.
414 See the
"lanserv/README.vm" file
in the OpenIPMI library
for more
415 details on the external
interface.
417 @item
-device isa
-ipmi
-kcs
,bmc
=@
var{id
}[,ioport
=@
var{val
}][,irq
=@
var{val
}]
419 Add a KCS IPMI interafce on the ISA bus
. This also adds a
420 corresponding ACPI and SMBIOS entries
, if appropriate
.
424 The BMC to connect to
, one of ipmi
-bmc
-sim or ipmi
-bmc
-extern above
.
425 @item ioport
=@
var{val
}
426 Define the I
/O address of the
interface. The
default is
0xca0 for KCS
.
428 Define the interrupt to use
. The
default is
5. To disable interrupts
,
432 @item
-device isa
-ipmi
-bt
,bmc
=@
var{id
}[,ioport
=@
var{val
}][,irq
=@
var{val
}]
434 Like the KCS
interface, but defines a BT
interface. The
default port is
435 0xe4 and the
default interrupt is
5.
439 DEF("name", HAS_ARG
, QEMU_OPTION_name
,
440 "-name string1[,process=string2][,debug-threads=on|off]\n"
441 " set the name of the guest\n"
442 " string1 sets the window title and string2 the process name (on Linux)\n"
443 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
444 " NOTE: The thread names are for debugging and not a stable API.\n",
447 @item
-name @
var{name
}
449 Sets the @
var{name
} of the guest
.
450 This name will be displayed
in the SDL window caption
.
451 The @
var{name
} will also be used
for the VNC server
.
452 Also optionally set the top visible process name
in Linux
.
453 Naming of individual threads can also be enabled on Linux to aid debugging
.
456 DEF("uuid", HAS_ARG
, QEMU_OPTION_uuid
,
457 "-uuid %08x-%04x-%04x-%04x-%012x\n"
458 " specify machine UUID\n", QEMU_ARCH_ALL
)
460 @item
-uuid @
var{uuid
}
470 DEFHEADING(Block device options
:)
475 DEF("fda", HAS_ARG
, QEMU_OPTION_fda
,
476 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL
)
477 DEF("fdb", HAS_ARG
, QEMU_OPTION_fdb
, "", QEMU_ARCH_ALL
)
479 @item
-fda @
var{file
}
480 @itemx
-fdb @
var{file
}
483 Use @
var{file
} as floppy disk
0/1 image (@pxref
{disk_images
}).
486 DEF("hda", HAS_ARG
, QEMU_OPTION_hda
,
487 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL
)
488 DEF("hdb", HAS_ARG
, QEMU_OPTION_hdb
, "", QEMU_ARCH_ALL
)
489 DEF("hdc", HAS_ARG
, QEMU_OPTION_hdc
,
490 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL
)
491 DEF("hdd", HAS_ARG
, QEMU_OPTION_hdd
, "", QEMU_ARCH_ALL
)
493 @item
-hda @
var{file
}
494 @itemx
-hdb @
var{file
}
495 @itemx
-hdc @
var{file
}
496 @itemx
-hdd @
var{file
}
501 Use @
var{file
} as hard disk
0, 1, 2 or
3 image (@pxref
{disk_images
}).
504 DEF("cdrom", HAS_ARG
, QEMU_OPTION_cdrom
,
505 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
508 @item
-cdrom @
var{file
}
510 Use @
var{file
} as CD
-ROM
image (you cannot use @option
{-hdc
} and
511 @option
{-cdrom
} at the same time
). You can use the host CD
-ROM by
512 using @file
{/dev
/cdrom
} as
filename (@pxref
{host_drives
}).
515 DEF("drive", HAS_ARG
, QEMU_OPTION_drive
,
516 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
517 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
518 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
519 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
520 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
521 " [,readonly=on|off][,copy-on-read=on|off]\n"
522 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
523 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
524 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
525 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
526 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
527 " [[,iops_size=is]]\n"
529 " use 'file' as a drive image\n", QEMU_ARCH_ALL
)
531 @item
-drive @
var{option
}[,@
var{option
}[,@
var{option
}[,...]]]
534 Define a
new drive
. Valid options are
:
537 @item file
=@
var{file
}
538 This option defines which disk
image (@pxref
{disk_images
}) to use with
539 this drive
. If the filename contains comma
, you must double it
540 (for instance
, "file=my,,file" to use file
"my,file").
542 Special files such as iSCSI devices can be specified
using protocol
543 specific URLs
. See the section
for "Device URL Syntax" for more information
.
544 @item
if=@
var{interface}
545 This option defines on which type on
interface the drive is connected
.
546 Available types are
: ide
, scsi
, sd
, mtd
, floppy
, pflash
, virtio
.
547 @item bus
=@
var{bus
},unit
=@
var{unit
}
548 These options define where is connected the drive by defining the bus number and
550 @item index
=@
var{index
}
551 This option defines where is connected the drive by
using an index
in the list
552 of available connectors of a given
interface type
.
553 @item media
=@
var{media
}
554 This option defines the type of the media
: disk or cdrom
.
555 @item cyls
=@
var{c
},heads
=@
var{h
},secs
=@
var{s
}[,trans
=@
var{t
}]
556 These options have the same definition as they have
in @option
{-hdachs
}.
557 @item snapshot
=@
var{snapshot
}
558 @
var{snapshot
} is
"on" or
"off" and controls snapshot mode
for the given drive
559 (see @option
{-snapshot
}).
560 @item cache
=@
var{cache
}
561 @
var{cache
} is
"none", "writeback", "unsafe", "directsync" or
"writethrough" and controls how the host cache is used to access block data
.
563 @
var{aio
} is
"threads", or
"native" and selects between pthread based disk I
/O and native Linux AIO
.
564 @item discard
=@
var{discard
}
565 @
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
.
566 @item format
=@
var{format
}
567 Specify which disk @
var{format
} will be used rather than detecting
568 the format
. Can be used to specifiy format
=raw to avoid interpreting
569 an untrusted format header
.
570 @item serial
=@
var{serial
}
571 This option specifies the serial number to assign to the device
.
572 @item addr
=@
var{addr
}
573 Specify the controller
's PCI address (if=virtio only).
574 @item werror=@var{action},rerror=@var{action}
575 Specify which @var{action} to take on write and read errors. Valid actions are:
576 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
577 "report" (report the error to the guest), "enospc" (pause QEMU only if the
578 host disk is full; report the error to the guest otherwise).
579 The default setting is @option{werror=enospc} and @option{rerror=report}.
581 Open drive @option{file} as read-only. Guest write attempts will fail.
582 @item copy-on-read=@var{copy-on-read}
583 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
584 file sectors into the image file.
585 @item detect-zeroes=@var{detect-zeroes}
586 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
587 conversion of plain zero writes by the OS to driver specific optimized
588 zero write commands. You may even choose "unmap" if @var{discard} is set
589 to "unmap" to allow a zero write to be converted to an UNMAP operation.
592 By default, the @option{cache=writeback} mode is used. It will report data
593 writes as completed as soon as the data is present in the host page cache.
594 This is safe as long as your guest OS makes sure to correctly flush disk caches
595 where needed. If your guest OS does not handle volatile disk write caches
596 correctly and your host crashes or loses power, then the guest may experience
599 For such guests, you should consider using @option{cache=writethrough}. This
600 means that the host page cache will be used to read and write data, but write
601 notification will be sent to the guest only after QEMU has made sure to flush
602 each write to the disk. Be aware that this has a major impact on performance.
604 The host page cache can be avoided entirely with @option{cache=none}. This will
605 attempt to do disk IO directly to the guest's memory
. QEMU may still perform
606 an internal copy of the data
. Note that
this is considered a writeback mode and
607 the guest OS must handle the disk write cache correctly
in order to avoid data
608 corruption on host crashes
.
610 The host page cache can be avoided
while only sending write notifications to
611 the guest when the data has been flushed to the disk
using
612 @option
{cache
=directsync
}.
614 In
case you don
't care about data integrity over host failures, use
615 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
616 data to the disk but can instead keep things in cache. If anything goes wrong,
617 like your host losing power, the disk storage getting disconnected accidentally,
618 etc. your image will most probably be rendered unusable. When using
619 the @option{-snapshot} option, unsafe caching is always used.
621 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
622 useful when the backing file is over a slow network. By default copy-on-read
625 Instead of @option{-cdrom} you can use:
627 qemu-system-i386 -drive file=file,index=2,media=cdrom
630 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
633 qemu-system-i386 -drive file=file,index=0,media=disk
634 qemu-system-i386 -drive file=file,index=1,media=disk
635 qemu-system-i386 -drive file=file,index=2,media=disk
636 qemu-system-i386 -drive file=file,index=3,media=disk
639 You can open an image using pre-opened file descriptors from an fd set:
642 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
643 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
644 -drive file=/dev/fdset/2,index=0,media=disk
647 You can connect a CDROM to the slave of ide0:
649 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
652 If you don't specify the
"file=" argument
, you define an empty drive
:
654 qemu
-system
-i386
-drive
if=ide
,index
=1,media
=cdrom
657 You can connect a SCSI disk with unit ID
6 on the bus #
0:
659 qemu
-system
-i386
-drive file
=file
,if=scsi
,bus
=0,unit
=6
662 Instead of @option
{-fda
}, @option
{-fdb
}, you can use
:
664 qemu
-system
-i386
-drive file
=file
,index
=0,if=floppy
665 qemu
-system
-i386
-drive file
=file
,index
=1,if=floppy
668 By
default, @
var{interface} is
"ide" and @
var{index
} is automatically
671 qemu
-system
-i386
-drive file
=a
-drive file
=b
"
675 qemu-system-i386 -hda a -hdb b
679 DEF("mtdblock
", HAS_ARG, QEMU_OPTION_mtdblock,
680 "-mtdblock file use
'file' as on
-board Flash memory image
\n",
683 @item -mtdblock @var{file}
685 Use @var{file} as on-board Flash memory image.
688 DEF("sd
", HAS_ARG, QEMU_OPTION_sd,
689 "-sd file use
'file' as SecureDigital card image
\n", QEMU_ARCH_ALL)
693 Use @var{file} as SecureDigital card image.
696 DEF("pflash
", HAS_ARG, QEMU_OPTION_pflash,
697 "-pflash file use
'file' as a parallel flash image
\n", QEMU_ARCH_ALL)
699 @item -pflash @var{file}
701 Use @var{file} as a parallel flash image.
704 DEF("snapshot
", 0, QEMU_OPTION_snapshot,
705 "-snapshot write to temporary files instead of disk image files
\n",
710 Write to temporary files instead of disk image files. In this case,
711 the raw disk image you use is not written back. You can however force
712 the write back by pressing @key{C-a s} (@pxref{disk_images}).
715 DEF("hdachs
", HAS_ARG, QEMU_OPTION_hdachs, \
716 "-hdachs c
,h
,s
[,t
]\n" \
717 " force hard disk
0 physical geometry and the optional BIOS
\n" \
718 " translation (t
=none or lba
) (usually QEMU can guess them
)\n",
721 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
723 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
724 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
725 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
726 all those parameters. This option is useful for old MS-DOS disk
730 DEF("fsdev
", HAS_ARG, QEMU_OPTION_fsdev,
731 "-fsdev fsdriver
,id
=id
[,path
=path
,][security_model
={mapped
-xattr|mapped
-file|passthrough|none
}]\n"
732 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
737 @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}]
739 Define a new file system device. Valid options are:
742 This option specifies the fs driver backend to use.
743 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
745 Specifies identifier for this device
746 @item path=@var{path}
747 Specifies the export path for the file system device. Files under
748 this path will be available to the 9p client on the guest.
749 @item security_model=@var{security_model}
750 Specifies the security model to be used for this export path.
751 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
752 In "passthrough
" security model, files are stored using the same
753 credentials as they are created on the guest. This requires QEMU
754 to run as root. In "mapped
-xattr
" security model, some of the file
755 attributes like uid, gid, mode bits and link target are stored as
756 file attributes. For "mapped
-file
" these attributes are stored in the
757 hidden .virtfs_metadata directory. Directories exported by this security model cannot
758 interact with other unix tools. "none
" security model is same as
759 passthrough except the sever won't report failures if it fails to
760 set file attributes like ownership. Security model is mandatory
761 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
762 security model as a parameter.
763 @item writeout=@var{writeout}
764 This is an optional argument. The only supported value is "immediate
".
765 This means that host page cache will be used to read and write data but
766 write notification will be sent to the guest only when the data has been
767 reported as written by the storage subsystem.
769 Enables exporting 9p share as a readonly mount for guests. By default
770 read-write access is given.
771 @item socket=@var{socket}
772 Enables proxy filesystem driver to use passed socket file for communicating
773 with virtfs-proxy-helper
774 @item sock_fd=@var{sock_fd}
775 Enables proxy filesystem driver to use passed socket descriptor for
776 communicating with virtfs-proxy-helper. Usually a helper like libvirt
777 will create socketpair and pass one of the fds as sock_fd
780 -fsdev option is used along with -device driver "virtio
-9p
-pci
".
781 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
782 Options for virtio-9p-pci driver are:
785 Specifies the id value specified along with -fsdev option
786 @item mount_tag=@var{mount_tag}
787 Specifies the tag name to be used by the guest to mount this export point
792 DEF("virtfs
", HAS_ARG, QEMU_OPTION_virtfs,
793 "-virtfs local
,path
=path
,mount_tag
=tag
,security_model
=[mapped
-xattr|mapped
-file|passthrough|none
]\n"
794 " [,writeout
=immediate
][,readonly
][,socket
=socket|sock_fd
=sock_fd
]\n",
799 @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}]
802 The general form of a Virtual File system pass-through options are:
805 This option specifies the fs driver backend to use.
806 Currently "local
", "handle
" and "proxy
" file system drivers are supported.
808 Specifies identifier for this device
809 @item path=@var{path}
810 Specifies the export path for the file system device. Files under
811 this path will be available to the 9p client on the guest.
812 @item security_model=@var{security_model}
813 Specifies the security model to be used for this export path.
814 Supported security models are "passthrough
", "mapped
-xattr
", "mapped
-file
" and "none
".
815 In "passthrough
" security model, files are stored using the same
816 credentials as they are created on the guest. This requires QEMU
817 to run as root. In "mapped
-xattr
" security model, some of the file
818 attributes like uid, gid, mode bits and link target are stored as
819 file attributes. For "mapped
-file
" these attributes are stored in the
820 hidden .virtfs_metadata directory. Directories exported by this security model cannot
821 interact with other unix tools. "none
" security model is same as
822 passthrough except the sever won't report failures if it fails to
823 set file attributes like ownership. Security model is mandatory only
824 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
825 model as a parameter.
826 @item writeout=@var{writeout}
827 This is an optional argument. The only supported value is "immediate
".
828 This means that host page cache will be used to read and write data but
829 write notification will be sent to the guest only when the data has been
830 reported as written by the storage subsystem.
832 Enables exporting 9p share as a readonly mount for guests. By default
833 read-write access is given.
834 @item socket=@var{socket}
835 Enables proxy filesystem driver to use passed socket file for
836 communicating with virtfs-proxy-helper. Usually a helper like libvirt
837 will create socketpair and pass one of the fds as sock_fd
839 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
840 descriptor for interfacing with virtfs-proxy-helper
844 DEF("virtfs_synth
", 0, QEMU_OPTION_virtfs_synth,
845 "-virtfs_synth Create synthetic file system image
\n",
849 @findex -virtfs_synth
850 Create synthetic file system image
858 DEFHEADING(USB options:)
863 DEF("usb
", 0, QEMU_OPTION_usb,
864 "-usb enable the USB
driver (will be the
default soon
)\n",
869 Enable the USB driver (will be the default soon)
872 DEF("usbdevice
", HAS_ARG, QEMU_OPTION_usbdevice,
873 "-usbdevice name add the host or guest USB device
'name'\n",
877 @item -usbdevice @var{devname}
879 Add the USB device @var{devname}. @xref{usb_devices}.
884 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
887 Pointer device that uses absolute coordinates (like a touchscreen). This
888 means QEMU is able to report the mouse position without having to grab the
889 mouse. Also overrides the PS/2 mouse emulation when activated.
891 @item disk:[format=@var{format}]:@var{file}
892 Mass storage device based on file. The optional @var{format} argument
893 will be used rather than detecting the format. Can be used to specifiy
894 @code{format=raw} to avoid interpreting an untrusted format header.
896 @item host:@var{bus}.@var{addr}
897 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
899 @item host:@var{vendor_id}:@var{product_id}
900 Pass through the host device identified by @var{vendor_id}:@var{product_id}
903 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
904 Serial converter to host character device @var{dev}, see @code{-serial} for the
908 Braille device. This will use BrlAPI to display the braille output on a real
911 @item net:@var{options}
912 Network adapter that supports CDC ethernet and RNDIS protocols.
922 DEFHEADING(Display options:)
927 DEF("display
", HAS_ARG, QEMU_OPTION_display,
928 "-display sdl
[,frame
=on|off
][,alt_grab
=on|off
][,ctrl_grab
=on|off
]\n"
929 " [,window_close
=on|off
]|curses|none|
\n"
930 " gtk
[,grab_on_hover
=on|off
]|
\n"
931 " vnc
=<display
>[,<optargs
>]\n"
932 " select display type
\n", QEMU_ARCH_ALL)
934 @item -display @var{type}
936 Select type of display to use. This option is a replacement for the
937 old style -sdl/-curses/... options. Valid values for @var{type} are
940 Display video output via SDL (usually in a separate graphics
941 window; see the SDL documentation for other possibilities).
943 Display video output via curses. For graphics device models which
944 support a text mode, QEMU can display this output using a
945 curses/ncurses interface. Nothing is displayed when the graphics
946 device is in graphical mode or if the graphics device does not support
947 a text mode. Generally only the VGA device models support text mode.
949 Do not display video output. The guest will still see an emulated
950 graphics card, but its output will not be displayed to the QEMU
951 user. This option differs from the -nographic option in that it
952 only affects what is done with video output; -nographic also changes
953 the destination of the serial and parallel port data.
955 Display video output in a GTK window. This interface provides drop-down
956 menus and other UI elements to configure and control the VM during
959 Start a VNC server on display <arg>
963 DEF("nographic
", 0, QEMU_OPTION_nographic,
964 "-nographic disable graphical output and redirect serial I
/Os to console
\n",
969 Normally, QEMU uses SDL to display the VGA output. With this option,
970 you can totally disable graphical output so that QEMU is a simple
971 command line application. The emulated serial port is redirected on
972 the console and muxed with the monitor (unless redirected elsewhere
973 explicitly). Therefore, you can still use QEMU to debug a Linux kernel
974 with a serial console. Use @key{C-a h} for help on switching between
975 the console and monitor.
978 DEF("curses
", 0, QEMU_OPTION_curses,
979 "-curses use a curses
/ncurses
interface instead of SDL
\n",
984 Normally, QEMU uses SDL to display the VGA output. With this option,
985 QEMU can display the VGA output when in text mode using a
986 curses/ncurses interface. Nothing is displayed in graphical mode.
989 DEF("no
-frame
", 0, QEMU_OPTION_no_frame,
990 "-no
-frame open SDL window without a frame and window decorations
\n",
995 Do not use decorations for SDL windows and start them using the whole
996 available screen space. This makes the using QEMU in a dedicated desktop
997 workspace more convenient.
1000 DEF("alt
-grab
", 0, QEMU_OPTION_alt_grab,
1001 "-alt
-grab use Ctrl
-Alt
-Shift to grab
mouse (instead of Ctrl
-Alt
)\n",
1006 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1007 affects the special keys (for fullscreen, monitor-mode switching, etc).
1010 DEF("ctrl
-grab
", 0, QEMU_OPTION_ctrl_grab,
1011 "-ctrl
-grab use Right
-Ctrl to grab
mouse (instead of Ctrl
-Alt
)\n",
1016 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1017 affects the special keys (for fullscreen, monitor-mode switching, etc).
1020 DEF("no
-quit
", 0, QEMU_OPTION_no_quit,
1021 "-no
-quit disable SDL window close capability
\n", QEMU_ARCH_ALL)
1025 Disable SDL window close capability.
1028 DEF("sdl
", 0, QEMU_OPTION_sdl,
1029 "-sdl enable SDL
\n", QEMU_ARCH_ALL)
1036 DEF("spice
", HAS_ARG, QEMU_OPTION_spice,
1037 "-spice
[port
=port
][,tls
-port
=secured
-port
][,x509
-dir
=<dir
>]\n"
1038 " [,x509
-key
-file
=<file
>][,x509
-key
-password
=<file
>]\n"
1039 " [,x509
-cert
-file
=<file
>][,x509
-cacert
-file
=<file
>]\n"
1040 " [,x509
-dh
-key
-file
=<file
>][,addr
=addr
][,ipv4|ipv6|unix
]\n"
1041 " [,tls
-ciphers
=<list
>]\n"
1042 " [,tls
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
1043 " [,plaintext
-channel
=[main|display|cursor|inputs|record|playback
]]\n"
1044 " [,sasl
][,password
=<secret
>][,disable
-ticketing
]\n"
1045 " [,image
-compression
=[auto_glz|auto_lz|quic|glz|lz|off
]]\n"
1046 " [,jpeg
-wan
-compression
=[auto|
never|always
]]\n"
1047 " [,zlib
-glz
-wan
-compression
=[auto|
never|always
]]\n"
1048 " [,streaming
-video
=[off|all|filter
]][,disable
-copy
-paste
]\n"
1049 " [,disable
-agent
-file
-xfer
][,agent
-mouse
=[on|off
]]\n"
1050 " [,playback
-compression
=[on|off
]][,seamless
-migration
=[on|off
]]\n"
1052 " at least one of
{port
, tls
-port
} is mandatory
\n",
1055 @item -spice @var{option}[,@var{option}[,...]]
1057 Enable the spice remote desktop protocol. Valid options are
1062 Set the TCP port spice is listening on for plaintext channels.
1065 Set the IP address spice is listening on. Default is any address.
1070 Force using the specified IP version.
1072 @item password=<secret>
1073 Set the password you need to authenticate.
1076 Require that the client use SASL to authenticate with the spice.
1077 The exact choice of authentication method used is controlled from the
1078 system / user's SASL configuration file for the 'qemu' service. This
1079 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1080 unprivileged user, an environment variable SASL_CONF_PATH can be used
1081 to make it search alternate locations for the service config.
1082 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1083 it is recommended that SASL always be combined with the 'tls' and
1084 'x509' settings to enable use of SSL and server certificates. This
1085 ensures a data encryption preventing compromise of authentication
1088 @item disable-ticketing
1089 Allow client connects without authentication.
1091 @item disable-copy-paste
1092 Disable copy paste between the client and the guest.
1094 @item disable-agent-file-xfer
1095 Disable spice-vdagent based file-xfer between the client and the guest.
1098 Set the TCP port spice is listening on for encrypted channels.
1100 @item x509-dir=<dir>
1101 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1103 @item x509-key-file=<file>
1104 @itemx x509-key-password=<file>
1105 @itemx x509-cert-file=<file>
1106 @itemx x509-cacert-file=<file>
1107 @itemx x509-dh-key-file=<file>
1108 The x509 file names can also be configured individually.
1110 @item tls-ciphers=<list>
1111 Specify which ciphers to use.
1113 @item tls-channel=[main|display|cursor|inputs|record|playback]
1114 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1115 Force specific channel to be used with or without TLS encryption. The
1116 options can be specified multiple times to configure multiple
1117 channels. The special name "default" can be used to set the default
1118 mode. For channels which are not explicitly forced into one mode the
1119 spice client is allowed to pick tls/plaintext as he pleases.
1121 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1122 Configure image compression (lossless).
1123 Default is auto_glz.
1125 @item jpeg-wan-compression=[auto|never|always]
1126 @itemx zlib-glz-wan-compression=[auto|never|always]
1127 Configure wan image compression (lossy for slow links).
1130 @item streaming-video=[off|all|filter]
1131 Configure video stream detection. Default is filter.
1133 @item agent-mouse=[on|off]
1134 Enable/disable passing mouse events via vdagent. Default is on.
1136 @item playback-compression=[on|off]
1137 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1139 @item seamless-migration=[on|off]
1140 Enable/disable spice seamless migration. Default is off.
1145 DEF("portrait
", 0, QEMU_OPTION_portrait,
1146 "-portrait rotate graphical output
90 deg
left (only PXA LCD
)\n",
1151 Rotate graphical output 90 deg left (only PXA LCD).
1154 DEF("rotate
", HAS_ARG, QEMU_OPTION_rotate,
1155 "-rotate
<deg
> rotate graphical output some deg
left (only PXA LCD
)\n",
1158 @item -rotate @var{deg}
1160 Rotate graphical output some deg left (only PXA LCD).
1163 DEF("vga
", HAS_ARG, QEMU_OPTION_vga,
1164 "-vga
[std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none
]\n"
1165 " select video card type
\n", QEMU_ARCH_ALL)
1167 @item -vga @var{type}
1169 Select type of VGA card to emulate. Valid values for @var{type} are
1172 Cirrus Logic GD5446 Video card. All Windows versions starting from
1173 Windows 95 should recognize and use this graphic card. For optimal
1174 performances, use 16 bit color depth in the guest and the host OS.
1175 (This one is the default)
1177 Standard VGA card with Bochs VBE extensions. If your guest OS
1178 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1179 to use high resolution modes (>= 1280x1024x16) then you should use
1182 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1183 recent XFree86/XOrg server or Windows guest with a driver for this
1186 QXL paravirtual graphic card. It is VGA compatible (including VESA
1187 2.0 VBE support). Works best with qxl guest drivers installed though.
1188 Recommended choice when using the spice protocol.
1190 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1191 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1192 fixed resolution of 1024x768.
1194 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1195 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1196 resolutions aimed at people wishing to run older Solaris versions.
1204 DEF("full
-screen
", 0, QEMU_OPTION_full_screen,
1205 "-full
-screen start
in full screen
\n", QEMU_ARCH_ALL)
1208 @findex -full-screen
1209 Start in full screen.
1212 DEF("g
", 1, QEMU_OPTION_g ,
1213 "-g WxH
[xDEPTH
] Set the initial graphical resolution and depth
\n",
1214 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1216 @item -g @var{width}x@var{height}[x@var{depth}]
1218 Set the initial graphical resolution and depth (PPC, SPARC only).
1221 DEF("vnc
", HAS_ARG, QEMU_OPTION_vnc ,
1222 "-vnc display start a VNC server on display
\n", QEMU_ARCH_ALL)
1224 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1226 Normally, QEMU uses SDL to display the VGA output. With this option,
1227 you can have QEMU listen on VNC display @var{display} and redirect the VGA
1228 display over the VNC session. It is very useful to enable the usb
1229 tablet device when using this option (option @option{-usbdevice
1230 tablet}). When using the VNC display, you must use the @option{-k}
1231 parameter to set the keyboard layout if you are not using en-us. Valid
1232 syntax for the @var{display} is
1236 @item @var{host}:@var{d}
1238 TCP connections will only be allowed from @var{host} on display @var{d}.
1239 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1240 be omitted in which case the server will accept connections from any host.
1242 @item unix:@var{path}
1244 Connections will be allowed over UNIX domain sockets where @var{path} is the
1245 location of a unix socket to listen for connections on.
1249 VNC is initialized but not started. The monitor @code{change} command
1250 can be used to later start the VNC server.
1254 Following the @var{display} value there may be one or more @var{option} flags
1255 separated by commas. Valid options are
1261 Connect to a listening VNC client via a ``reverse'' connection. The
1262 client is specified by the @var{display}. For reverse network
1263 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1264 is a TCP port number, not a display number.
1268 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1269 By definition the Websocket port is 5700+@var{display}. If @var{host} is
1270 specified connections will only be allowed from this host.
1271 As an alternative the Websocket port could be specified by using
1272 @code{websocket}=@var{port}.
1273 If no TLS credentials are provided, the websocket connection runs in
1274 unencrypted mode. If TLS credentials are provided, the websocket connection
1275 requires encrypted client connections.
1279 Require that password based authentication is used for client connections.
1281 The password must be set separately using the @code{set_password} command in
1282 the @ref{pcsys_monitor}. The syntax to change your password is:
1283 @code{set_password <protocol> <password>} where <protocol> could be either
1286 If you would like to change <protocol> password expiration, you should use
1287 @code{expire_password <protocol> <expiration-time>} where expiration time could
1288 be one of the following options: now, never, +seconds or UNIX time of
1289 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1290 to make password expire on "Mon Apr
23 12:00:00 EDT
2012" (UNIX time for this
1293 You can also use keywords "now
" or "never" for the expiration time to
1294 allow <protocol> password to expire immediately or never expire.
1296 @item tls-creds=@var{ID}
1298 Provides the ID of a set of TLS credentials to use to secure the
1299 VNC server. They will apply to both the normal VNC server socket
1300 and the websocket socket (if enabled). Setting TLS credentials
1301 will cause the VNC server socket to enable the VeNCrypt auth
1302 mechanism. The credentials should have been previously created
1303 using the @option{-object tls-creds} argument.
1305 The @option{tls-creds} parameter obsoletes the @option{tls},
1306 @option{x509}, and @option{x509verify} options, and as such
1307 it is not permitted to set both new and old type options at
1312 Require that client use TLS when communicating with the VNC server. This
1313 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1314 attack. It is recommended that this option be combined with either the
1315 @option{x509} or @option{x509verify} options.
1317 This option is now deprecated in favor of using the @option{tls-creds}
1320 @item x509=@var{/path/to/certificate/dir}
1322 Valid if @option{tls} is specified. Require that x509 credentials are used
1323 for negotiating the TLS session. The server will send its x509 certificate
1324 to the client. It is recommended that a password be set on the VNC server
1325 to provide authentication of the client when this is used. The path following
1326 this option specifies where the x509 certificates are to be loaded from.
1327 See the @ref{vnc_security} section for details on generating certificates.
1329 This option is now deprecated in favour of using the @option{tls-creds}
1332 @item x509verify=@var{/path/to/certificate/dir}
1334 Valid if @option{tls} is specified. Require that x509 credentials are used
1335 for negotiating the TLS session. The server will send its x509 certificate
1336 to the client, and request that the client send its own x509 certificate.
1337 The server will validate the client's certificate against the CA certificate,
1338 and reject clients when validation fails. If the certificate authority is
1339 trusted, this is a sufficient authentication mechanism. You may still wish
1340 to set a password on the VNC server as a second authentication layer. The
1341 path following this option specifies where the x509 certificates are to
1342 be loaded from. See the @ref{vnc_security} section for details on generating
1345 This option is now deprecated in favour of using the @option{tls-creds}
1350 Require that the client use SASL to authenticate with the VNC server.
1351 The exact choice of authentication method used is controlled from the
1352 system / user's SASL configuration file for the 'qemu' service. This
1353 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1354 unprivileged user, an environment variable SASL_CONF_PATH can be used
1355 to make it search alternate locations for the service config.
1356 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1357 it is recommended that SASL always be combined with the 'tls' and
1358 'x509' settings to enable use of SSL and server certificates. This
1359 ensures a data encryption preventing compromise of authentication
1360 credentials. See the @ref{vnc_security} section for details on using
1361 SASL authentication.
1365 Turn on access control lists for checking of the x509 client certificate
1366 and SASL party. For x509 certs, the ACL check is made against the
1367 certificate's distinguished name. This is something that looks like
1368 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1369 made against the username, which depending on the SASL plugin, may
1370 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1371 When the @option{acl} flag is set, the initial access list will be
1372 empty, with a @code{deny} policy. Thus no one will be allowed to
1373 use the VNC server until the ACLs have been loaded. This can be
1374 achieved using the @code{acl} monitor command.
1378 Enable lossy compression methods (gradient, JPEG, ...). If this
1379 option is set, VNC client may receive lossy framebuffer updates
1380 depending on its encoding settings. Enabling this option can save
1381 a lot of bandwidth at the expense of quality.
1385 Disable adaptive encodings. Adaptive encodings are enabled by default.
1386 An adaptive encoding will try to detect frequently updated screen regions,
1387 and send updates in these regions using a lossy encoding (like JPEG).
1388 This can be really helpful to save bandwidth when playing videos. Disabling
1389 adaptive encodings restores the original static behavior of encodings
1392 @item share=[allow-exclusive|force-shared|ignore]
1394 Set display sharing policy. 'allow-exclusive' allows clients to ask
1395 for exclusive access. As suggested by the rfb spec this is
1396 implemented by dropping other connections. Connecting multiple
1397 clients in parallel requires all clients asking for a shared session
1398 (vncviewer: -shared switch). This is the default. 'force-shared'
1399 disables exclusive client access. Useful for shared desktop sessions,
1400 where you don't want someone forgetting specify -shared disconnect
1401 everybody else. 'ignore' completely ignores the shared flag and
1402 allows everybody connect unconditionally. Doesn't conform to the rfb
1403 spec but is traditional QEMU behavior.
1411 ARCHHEADING(, QEMU_ARCH_I386)
1413 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1418 DEF("win2k
-hack
", 0, QEMU_OPTION_win2k_hack,
1419 "-win2k
-hack use it when installing Windows
2000 to avoid a disk full bug
\n",
1424 Use it when installing Windows 2000 to avoid a disk full bug. After
1425 Windows 2000 is installed, you no longer need this option (this option
1426 slows down the IDE transfers).
1429 HXCOMM Deprecated by -rtc
1430 DEF("rtc
-td
-hack
", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1432 DEF("no
-fd
-bootchk
", 0, QEMU_OPTION_no_fd_bootchk,
1433 "-no
-fd
-bootchk disable boot signature checking
for floppy disks
\n",
1436 @item -no-fd-bootchk
1437 @findex -no-fd-bootchk
1438 Disable boot signature checking for floppy disks in BIOS. May
1439 be needed to boot from old floppy disks.
1442 DEF("no
-acpi
", 0, QEMU_OPTION_no_acpi,
1443 "-no
-acpi disable ACPI
\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1447 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1448 it if your guest OS complains about ACPI problems (PC target machine
1452 DEF("no
-hpet
", 0, QEMU_OPTION_no_hpet,
1453 "-no
-hpet disable HPET
\n", QEMU_ARCH_I386)
1457 Disable HPET support.
1460 DEF("acpitable
", HAS_ARG, QEMU_OPTION_acpitable,
1461 "-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"
1462 " ACPI table description
\n", QEMU_ARCH_I386)
1464 @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}]...]
1466 Add ACPI table with specified header fields and context from specified files.
1467 For file=, take whole ACPI table from the specified files, including all
1468 ACPI headers (possible overridden by other options).
1469 For data=, only data
1470 portion of the table is used, all header information is specified in the
1474 DEF("smbios
", HAS_ARG, QEMU_OPTION_smbios,
1475 "-smbios file
=binary
\n"
1476 " load SMBIOS entry from binary file
\n"
1477 "-smbios type
=0[,vendor
=str
][,version
=str
][,date
=str
][,release
=%d
.%d
]\n"
1479 " specify SMBIOS type
0 fields
\n"
1480 "-smbios type
=1[,manufacturer
=str
][,product
=str
][,version
=str
][,serial
=str
]\n"
1481 " [,uuid
=uuid
][,sku
=str
][,family
=str
]\n"
1482 " specify SMBIOS type
1 fields
\n"
1483 "-smbios type
=2[,manufacturer
=str
][,product
=str
][,version
=str
][,serial
=str
]\n"
1484 " [,asset
=str
][,location
=str
]\n"
1485 " specify SMBIOS type
2 fields
\n"
1486 "-smbios type
=3[,manufacturer
=str
][,version
=str
][,serial
=str
][,asset
=str
]\n"
1488 " specify SMBIOS type
3 fields
\n"
1489 "-smbios type
=4[,sock_pfx
=str
][,manufacturer
=str
][,version
=str
][,serial
=str
]\n"
1490 " [,asset
=str
][,part
=str
]\n"
1491 " specify SMBIOS type
4 fields
\n"
1492 "-smbios type
=17[,loc_pfx
=str
][,bank
=str
][,manufacturer
=str
][,serial
=str
]\n"
1493 " [,asset
=str
][,part
=str
][,speed
=%d
]\n"
1494 " specify SMBIOS type
17 fields
\n",
1495 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1497 @item -smbios file=@var{binary}
1499 Load SMBIOS entry from binary file.
1501 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1502 Specify SMBIOS type 0 fields
1504 @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}]
1505 Specify SMBIOS type 1 fields
1507 @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}]
1508 Specify SMBIOS type 2 fields
1510 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1511 Specify SMBIOS type 3 fields
1513 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1514 Specify SMBIOS type 4 fields
1516 @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}]
1517 Specify SMBIOS type 17 fields
1525 DEFHEADING(Network options:)
1530 HXCOMM Legacy slirp options (now moved to -net user):
1532 DEF("tftp
", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1533 DEF("bootp
", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1534 DEF("redir
", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1536 DEF("smb
", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1540 DEF("netdev
", HAS_ARG, QEMU_OPTION_netdev,
1542 "-netdev user
,id
=str
[,net
=addr
[/mask
]][,host
=addr
][,restrict
=on|off
]\n"
1543 " [,hostname
=host
][,dhcpstart
=addr
][,dns
=addr
][,dnssearch
=domain
][,tftp
=dir
]\n"
1544 " [,bootfile
=f
][,hostfwd
=rule
][,guestfwd
=rule
]"
1546 "[,smb
=dir
[,smbserver
=addr
]]\n"
1548 " configure a user mode network backend with ID
'str',\n"
1549 " its DHCP server and optional services
\n"
1552 "-netdev tap
,id
=str
,ifname
=name
\n"
1553 " configure a host TAP network backend with ID
'str'\n"
1555 "-netdev tap
,id
=str
[,fd
=h
][,fds
=x
:y
:...:z
][,ifname
=name
][,script
=file
][,downscript
=dfile
]\n"
1556 " [,helper
=helper
][,sndbuf
=nbytes
][,vnet_hdr
=on|off
][,vhost
=on|off
]\n"
1557 " [,vhostfd
=h
][,vhostfds
=x
:y
:...:z
][,vhostforce
=on|off
][,queues
=n
]\n"
1558 " configure a host TAP network backend with ID
'str'\n"
1559 " use network scripts
'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1560 " to configure it and
'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1561 " to deconfigure it
\n"
1562 " use
'[down]script=no' to disable script execution
\n"
1563 " use network helper
'helper' (default=" DEFAULT_BRIDGE_HELPER ") to
\n"
1565 " use
'fd=h' to connect to an already opened TAP
interface\n"
1566 " use
'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces
\n"
1567 " use
'sndbuf=nbytes' to limit the size of the send
buffer (the
\n"
1568 " default is disabled
'sndbuf=0' to enable flow control set
'sndbuf=1048576')\n"
1569 " use vnet_hdr
=off to avoid enabling the IFF_VNET_HDR tap flag
\n"
1570 " use vnet_hdr
=on to make the lack of IFF_VNET_HDR support an error condition
\n"
1571 " use vhost
=on to enable experimental
in kernel accelerator
\n"
1572 " (only has effect
for virtio guests which use MSIX
)\n"
1573 " use vhostforce
=on to force vhost on
for non
-MSIX virtio guests
\n"
1574 " use
'vhostfd=h' to connect to an already opened vhost net device
\n"
1575 " use
'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1576 " use 'queues
=n
' to specify the number of queues to be created for multiqueue TAP\n"
1577 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1578 " configure a host TAP network backend with ID 'str
' that is\n"
1579 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1580 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1583 "-netdev l2tpv3
,id
=str
,src
=srcaddr
,dst
=dstaddr
[,srcport
=srcport
][,dstport
=dstport
]\n"
1584 " [,rxsession
=rxsession
],txsession
=txsession
[,ipv6
=on
/off
][,udp
=on
/off
]\n"
1585 " [,cookie64
=on
/off
][,counter
][,pincounter
][,txcookie
=txcookie
]\n"
1586 " [,rxcookie
=rxcookie
][,offset
=offset
]\n"
1587 " configure a network backend with ID
'str' connected to
\n"
1588 " an Ethernet over L2TPv3 pseudowire
.\n"
1589 " Linux kernel
3.3+ as well as most routers can talk
\n"
1590 " L2TPv3
. This transport allows connecting a VM to a VM
,\n"
1591 " VM to a router and even VM to Host
. It is a nearly
-universal
\n"
1592 " standard (RFC3391
). Note
- this implementation uses
static\n"
1593 " pre
-configured
tunnels (same as the Linux kernel
).\n"
1594 " use
'src=' to specify source address
\n"
1595 " use
'dst=' to specify destination address
\n"
1596 " use
'udp=on' to specify udp encapsulation
\n"
1597 " use
'srcport=' to specify source udp port
\n"
1598 " use
'dstport=' to specify destination udp port
\n"
1599 " use
'ipv6=on' to force v6
\n"
1600 " L2TPv3 uses cookies to prevent misconfiguration as
\n"
1601 " well as a weak security measure
\n"
1602 " use
'rxcookie=0x012345678' to specify a rxcookie
\n"
1603 " use
'txcookie=0x012345678' to specify a txcookie
\n"
1604 " use
'cookie64=on' to set cookie size to
64 bit
, otherwise
32\n"
1605 " use
'counter=off' to force a
'cut-down' L2TPv3 with no counter
\n"
1606 " use
'pincounter=on' to work around broken counter handling
in peer
\n"
1607 " use
'offset=X' to add an extra offset between header and data
\n"
1609 "-netdev socket
,id
=str
[,fd
=h
][,listen
=[host
]:port
][,connect
=host
:port
]\n"
1610 " configure a network backend to connect to another network
\n"
1611 " using a socket connection
\n"
1612 "-netdev socket
,id
=str
[,fd
=h
][,mcast
=maddr
:port
[,localaddr
=addr
]]\n"
1613 " configure a network backend to connect to a multicast maddr and port
\n"
1614 " use
'localaddr=addr' to specify the host address to send packets from
\n"
1615 "-netdev socket
,id
=str
[,fd
=h
][,udp
=host
:port
][,localaddr
=host
:port
]\n"
1616 " configure a network backend to connect to another network
\n"
1617 " using an UDP tunnel
\n"
1619 "-netdev vde
,id
=str
[,sock
=socketpath
][,port
=n
][,group
=groupname
][,mode
=octalmode
]\n"
1620 " configure a network backend to connect to port
'n' of a vde
switch\n"
1621 " running on host and listening
for incoming connections on
'socketpath'.\n"
1622 " Use group
'groupname' and mode
'octalmode' to change
default\n"
1623 " ownership and permissions
for communication port
.\n"
1625 #ifdef CONFIG_NETMAP
1626 "-netdev netmap
,id
=str
,ifname
=name
[,devname
=nmname
]\n"
1627 " attach to the existing netmap
-enabled network
interface 'name', or to a
\n"
1628 " VALE
port (created on the fly
) called
'name' ('nmname' is name of the
\n"
1629 " netmap device
, defaults to
'/dev/netmap')\n"
1631 "-netdev vhost
-user
,id
=str
,chardev
=dev
[,vhostforce
=on|off
]\n"
1632 " configure a vhost
-user network
, backed by a chardev
'dev'\n"
1633 "-netdev hubport
,id
=str
,hubid
=n
\n"
1634 " configure a hub port on QEMU VLAN
'n'\n", QEMU_ARCH_ALL)
1635 DEF("net
", HAS_ARG, QEMU_OPTION_net,
1636 "-net nic
[,vlan
=n
][,macaddr
=mac
][,model
=type
][,name
=str
][,addr
=str
][,vectors
=v
]\n"
1637 " old way to create a
new NIC and connect it to VLAN
'n'\n"
1638 " (use the
'-device devtype,netdev=str' option
if possible instead
)\n"
1639 "-net dump
[,vlan
=n
][,file
=f
][,len
=n
]\n"
1640 " dump traffic on vlan
'n' to file
'f' (max n bytes per packet
)\n"
1641 "-net none use it alone to have zero network devices
. If no
-net option
\n"
1642 " is provided
, the
default is
'-net nic -net user'\n"
1652 #ifdef CONFIG_NETMAP
1655 "socket
][,vlan
=n
][,option
][,option
][,...]\n"
1656 " old way to initialize a host network
interface\n"
1657 " (use the
-netdev option
if possible instead
)\n", QEMU_ARCH_ALL)
1659 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1661 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1662 = 0 is the default). The NIC is an e1000 by default on the PC
1663 target. Optionally, the MAC address can be changed to @var{mac}, the
1664 device address set to @var{addr} (PCI cards only),
1665 and a @var{name} can be assigned for use in monitor commands.
1666 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1667 that the card should have; this option currently only affects virtio cards; set
1668 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1669 NIC is created. QEMU can emulate several different models of network card.
1670 Valid values for @var{type} are
1671 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1672 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1673 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1674 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1675 for a list of available devices for your target.
1677 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1679 @item -net user[,@var{option}][,@var{option}][,...]
1680 Use the user mode network stack which requires no administrator
1681 privilege to run. Valid options are:
1685 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1688 @itemx name=@var{name}
1689 Assign symbolic name for use in monitor commands.
1691 @item net=@var{addr}[/@var{mask}]
1692 Set IP network address the guest will see. Optionally specify the netmask,
1693 either in the form a.b.c.d or as number of valid top-most bits. Default is
1696 @item host=@var{addr}
1697 Specify the guest-visible address of the host. Default is the 2nd IP in the
1698 guest network, i.e. x.x.x.2.
1700 @item restrict=on|off
1701 If this option is enabled, the guest will be isolated, i.e. it will not be
1702 able to contact the host and no guest IP packets will be routed over the host
1703 to the outside. This option does not affect any explicitly set forwarding rules.
1705 @item hostname=@var{name}
1706 Specifies the client hostname reported by the built-in DHCP server.
1708 @item dhcpstart=@var{addr}
1709 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1710 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1712 @item dns=@var{addr}
1713 Specify the guest-visible address of the virtual nameserver. The address must
1714 be different from the host address. Default is the 3rd IP in the guest network,
1717 @item dnssearch=@var{domain}
1718 Provides an entry for the domain-search list sent by the built-in
1719 DHCP server. More than one domain suffix can be transmitted by specifying
1720 this option multiple times. If supported, this will cause the guest to
1721 automatically try to append the given domain suffix(es) in case a domain name
1722 can not be resolved.
1726 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1729 @item tftp=@var{dir}
1730 When using the user mode network stack, activate a built-in TFTP
1731 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1732 The TFTP client on the guest must be configured in binary mode (use the command
1733 @code{bin} of the Unix TFTP client).
1735 @item bootfile=@var{file}
1736 When using the user mode network stack, broadcast @var{file} as the BOOTP
1737 filename. In conjunction with @option{tftp}, this can be used to network boot
1738 a guest from a local directory.
1740 Example (using pxelinux):
1742 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1745 @item smb=@var{dir}[,smbserver=@var{addr}]
1746 When using the user mode network stack, activate a built-in SMB
1747 server so that Windows OSes can access to the host files in @file{@var{dir}}
1748 transparently. The IP address of the SMB server can be set to @var{addr}. By
1749 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1751 In the guest Windows OS, the line:
1755 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1756 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1758 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1760 Note that a SAMBA server must be installed on the host OS.
1761 QEMU was tested successfully with smbd versions from Red Hat 9,
1762 Fedora Core 3 and OpenSUSE 11.x.
1764 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1765 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1766 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1767 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1768 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1769 be bound to a specific host interface. If no connection type is set, TCP is
1770 used. This option can be given multiple times.
1772 For example, to redirect host X11 connection from screen 1 to guest
1773 screen 0, use the following:
1777 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1778 # this host xterm should open in the guest X11 server
1782 To redirect telnet connections from host port 5555 to telnet port on
1783 the guest, use the following:
1787 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1788 telnet localhost 5555
1791 Then when you use on the host @code{telnet localhost 5555}, you
1792 connect to the guest telnet server.
1794 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1795 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1796 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1797 to the character device @var{dev} or to a program executed by @var{cmd:command}
1798 which gets spawned for each connection. This option can be given multiple times.
1800 You can either use a chardev directly and have that one used throughout QEMU's
1801 lifetime, like in the following example:
1804 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
1805 # the guest accesses it
1806 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
1809 Or you can execute a command on every TCP connection established by the guest,
1810 so that QEMU behaves similar to an inetd process for that virtual server:
1813 # call "netcat
10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
1814 # and connect the TCP stream to its stdin/stdout
1815 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1820 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1821 processed and applied to -net user. Mixing them with the new configuration
1822 syntax gives undefined results. Their use for new applications is discouraged
1823 as they will be removed from future versions.
1825 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1826 @itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1827 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1829 Use the network script @var{file} to configure it and the network script
1830 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1831 automatically provides one. The default network configure script is
1832 @file{/etc/qemu-ifup} and the default network deconfigure script is
1833 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1834 to disable script execution.
1836 If running QEMU as an unprivileged user, use the network helper
1837 @var{helper} to configure the TAP interface. The default network
1838 helper executable is @file{/path/to/qemu-bridge-helper}.
1840 @option{fd}=@var{h} can be used to specify the handle of an already
1841 opened host TAP interface.
1846 #launch a QEMU instance with the default network script
1847 qemu-system-i386 linux.img -net nic -net tap
1851 #launch a QEMU instance with two NICs, each one connected
1853 qemu-system-i386 linux.img \
1854 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1855 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1859 #launch a QEMU instance with the default network helper to
1860 #connect a TAP device to bridge br0
1861 qemu-system-i386 linux.img \
1862 -net nic -net tap,"helper
=/path
/to
/qemu
-bridge
-helper
"
1865 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
1866 @itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1867 Connect a host TAP network interface to a host bridge device.
1869 Use the network helper @var{helper} to configure the TAP interface and
1870 attach it to the bridge. The default network helper executable is
1871 @file{/path/to/qemu-bridge-helper} and the default bridge
1872 device is @file{br0}.
1877 #launch a QEMU instance with the default network helper to
1878 #connect a TAP device to bridge br0
1879 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
1883 #launch a QEMU instance with the default network helper to
1884 #connect a TAP device to bridge qemubr0
1885 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1888 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1889 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1891 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1892 machine using a TCP socket connection. If @option{listen} is
1893 specified, QEMU waits for incoming connections on @var{port}
1894 (@var{host} is optional). @option{connect} is used to connect to
1895 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1896 specifies an already opened TCP socket.
1900 # launch a first QEMU instance
1901 qemu-system-i386 linux.img \
1902 -net nic,macaddr=52:54:00:12:34:56 \
1903 -net socket,listen=:1234
1904 # connect the VLAN 0 of this instance to the VLAN 0
1905 # of the first instance
1906 qemu-system-i386 linux.img \
1907 -net nic,macaddr=52:54:00:12:34:57 \
1908 -net socket,connect=127.0.0.1:1234
1911 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1912 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1914 Create a VLAN @var{n} shared with another QEMU virtual
1915 machines using a UDP multicast socket, effectively making a bus for
1916 every QEMU with same multicast address @var{maddr} and @var{port}.
1920 Several QEMU can be running on different hosts and share same bus (assuming
1921 correct multicast setup for these hosts).
1923 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1924 @url{http://user-mode-linux.sf.net}.
1926 Use @option{fd=h} to specify an already opened UDP multicast socket.
1931 # launch one QEMU instance
1932 qemu-system-i386 linux.img \
1933 -net nic,macaddr=52:54:00:12:34:56 \
1934 -net socket,mcast=230.0.0.1:1234
1935 # launch another QEMU instance on same "bus
"
1936 qemu-system-i386 linux.img \
1937 -net nic,macaddr=52:54:00:12:34:57 \
1938 -net socket,mcast=230.0.0.1:1234
1939 # launch yet another QEMU instance on same "bus
"
1940 qemu-system-i386 linux.img \
1941 -net nic,macaddr=52:54:00:12:34:58 \
1942 -net socket,mcast=230.0.0.1:1234
1945 Example (User Mode Linux compat.):
1947 # launch QEMU instance (note mcast address selected
1949 qemu-system-i386 linux.img \
1950 -net nic,macaddr=52:54:00:12:34:56 \
1951 -net socket,mcast=239.192.168.1:1102
1953 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1956 Example (send packets from host's 1.2.3.4):
1958 qemu-system-i386 linux.img \
1959 -net nic,macaddr=52:54:00:12:34:56 \
1960 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
1963 @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}]
1964 @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}]
1965 Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
1966 protocol to transport Ethernet (and other Layer 2) data frames between
1967 two systems. It is present in routers, firewalls and the Linux kernel
1968 (from version 3.3 onwards).
1970 This transport allows a VM to communicate to another VM, router or firewall directly.
1972 @item src=@var{srcaddr}
1973 source address (mandatory)
1974 @item dst=@var{dstaddr}
1975 destination address (mandatory)
1977 select udp encapsulation (default is ip).
1978 @item srcport=@var{srcport}
1980 @item dstport=@var{dstport}
1981 destination udp port.
1983 force v6, otherwise defaults to v4.
1984 @item rxcookie=@var{rxcookie}
1985 @itemx txcookie=@var{txcookie}
1986 Cookies are a weak form of security in the l2tpv3 specification.
1987 Their function is mostly to prevent misconfiguration. By default they are 32
1990 Set cookie size to 64 bit instead of the default 32
1992 Force a 'cut-down' L2TPv3 with no counter as in
1993 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
1995 Work around broken counter handling in peer. This may also help on
1996 networks which have packet reorder.
1997 @item offset=@var{offset}
1998 Add an extra offset between header and data
2000 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2001 on the remote Linux host 1.2.3.4:
2003 # Setup tunnel on linux host using raw ip as encapsulation
2005 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2006 encap udp udp_sport 16384 udp_dport 16384
2007 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2008 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2009 ifconfig vmtunnel0 mtu 1500
2010 ifconfig vmtunnel0 up
2011 brctl addif br-lan vmtunnel0
2015 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2017 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
2022 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2023 @itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2024 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2025 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2026 and MODE @var{octalmode} to change default ownership and permissions for
2027 communication port. This option is only available if QEMU has been compiled
2028 with vde support enabled.
2033 vde_switch -F -sock /tmp/myswitch
2034 # launch QEMU instance
2035 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2038 @item -netdev hubport,id=@var{id},hubid=@var{hubid}
2040 Create a hub port on QEMU "vlan
" @var{hubid}.
2042 The hubport netdev lets you connect a NIC to a QEMU "vlan
" instead of a single
2043 netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
2044 required hub automatically.
2046 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2048 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2049 be a unix domain socket backed one. The vhost-user uses a specifically defined
2050 protocol to pass vhost ioctl replacement messages to an application on the other
2051 end of the socket. On non-MSIX guests, the feature can be forced with
2052 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2053 be created for multiqueue vhost-user.
2057 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2058 -numa node,memdev=mem \
2059 -chardev socket,path=/path/to/socket \
2060 -netdev type=vhost-user,id=net0,chardev=chr0 \
2061 -device virtio-net-pci,netdev=net0
2064 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
2065 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
2066 At most @var{len} bytes (64k by default) per packet are stored. The file format is
2067 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
2068 Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
2071 Indicate that no network devices should be configured. It is used to
2072 override the default configuration (@option{-net nic -net user}) which
2073 is activated if no @option{-net} options are provided.
2081 DEFHEADING(Character device options:)
2084 The general form of a character device option is:
2088 DEF("chardev
", HAS_ARG, QEMU_OPTION_chardev,
2089 "-chardev
null,id
=id
[,mux
=on|off
]\n"
2090 "-chardev socket
,id
=id
[,host
=host
],port
=port
[,to
=to
][,ipv4
][,ipv6
][,nodelay
][,reconnect
=seconds
]\n"
2091 " [,server
][,nowait
][,telnet
][,reconnect
=seconds
][,mux
=on|off
] (tcp
)\n"
2092 "-chardev socket
,id
=id
,path
=path
[,server
][,nowait
][,telnet
][,reconnect
=seconds
][,mux
=on|off
] (unix
)\n"
2093 "-chardev udp
,id
=id
[,host
=host
],port
=port
[,localaddr
=localaddr
]\n"
2094 " [,localport
=localport
][,ipv4
][,ipv6
][,mux
=on|off
]\n"
2095 "-chardev msmouse
,id
=id
[,mux
=on|off
]\n"
2096 "-chardev vc
,id
=id
[[,width
=width
][,height
=height
]][[,cols
=cols
][,rows
=rows
]]\n"
2098 "-chardev ringbuf
,id
=id
[,size
=size
]\n"
2099 "-chardev file
,id
=id
,path
=path
[,mux
=on|off
]\n"
2100 "-chardev pipe
,id
=id
,path
=path
[,mux
=on|off
]\n"
2102 "-chardev console
,id
=id
[,mux
=on|off
]\n"
2103 "-chardev serial
,id
=id
,path
=path
[,mux
=on|off
]\n"
2105 "-chardev pty
,id
=id
[,mux
=on|off
]\n"
2106 "-chardev stdio
,id
=id
[,mux
=on|off
][,signal
=on|off
]\n"
2108 #ifdef CONFIG_BRLAPI
2109 "-chardev braille
,id
=id
[,mux
=on|off
]\n"
2111 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2112 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2113 "-chardev serial
,id
=id
,path
=path
[,mux
=on|off
]\n"
2114 "-chardev tty
,id
=id
,path
=path
[,mux
=on|off
]\n"
2116 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2117 "-chardev parallel
,id
=id
,path
=path
[,mux
=on|off
]\n"
2118 "-chardev parport
,id
=id
,path
=path
[,mux
=on|off
]\n"
2120 #if defined(CONFIG_SPICE)
2121 "-chardev spicevmc
,id
=id
,name
=name
[,debug
=debug
]\n"
2122 "-chardev spiceport
,id
=id
,name
=name
[,debug
=debug
]\n"
2128 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
2149 The specific backend will determine the applicable options.
2151 All devices must have an id, which can be any string up to 127 characters long.
2152 It is used to uniquely identify this device in other command line directives.
2154 A character device may be used in multiplexing mode by multiple front-ends.
2155 The key sequence of @key{Control-a} and @key{c} will rotate the input focus
2156 between attached front-ends. Specify @option{mux=on} to enable this mode.
2158 Options to each backend are described below.
2160 @item -chardev null ,id=@var{id}
2161 A void device. This device will not emit any data, and will drop any data it
2162 receives. The null backend does not take any options.
2164 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}]
2166 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2167 unix socket will be created if @option{path} is specified. Behaviour is
2168 undefined if TCP options are specified for a unix socket.
2170 @option{server} specifies that the socket shall be a listening socket.
2172 @option{nowait} specifies that QEMU should not block waiting for a client to
2173 connect to a listening socket.
2175 @option{telnet} specifies that traffic on the socket should interpret telnet
2178 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2179 the remote end goes away. qemu will delay this many seconds and then attempt
2180 to reconnect. Zero disables reconnecting, and is the default.
2182 TCP and unix socket options are given below:
2186 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2188 @option{host} for a listening socket specifies the local address to be bound.
2189 For a connecting socket species the remote host to connect to. @option{host} is
2190 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2192 @option{port} for a listening socket specifies the local port to be bound. For a
2193 connecting socket specifies the port on the remote host to connect to.
2194 @option{port} can be given as either a port number or a service name.
2195 @option{port} is required.
2197 @option{to} is only relevant to listening sockets. If it is specified, and
2198 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2199 to and including @option{to} until it succeeds. @option{to} must be specified
2202 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2203 If neither is specified the socket may use either protocol.
2205 @option{nodelay} disables the Nagle algorithm.
2207 @item unix options: path=@var{path}
2209 @option{path} specifies the local path of the unix socket. @option{path} is
2214 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2216 Sends all traffic from the guest to a remote host over UDP.
2218 @option{host} specifies the remote host to connect to. If not specified it
2219 defaults to @code{localhost}.
2221 @option{port} specifies the port on the remote host to connect to. @option{port}
2224 @option{localaddr} specifies the local address to bind to. If not specified it
2225 defaults to @code{0.0.0.0}.
2227 @option{localport} specifies the local port to bind to. If not specified any
2228 available local port will be used.
2230 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2231 If neither is specified the device may use either protocol.
2233 @item -chardev msmouse ,id=@var{id}
2235 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2238 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2240 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2243 @option{width} and @option{height} specify the width and height respectively of
2244 the console, in pixels.
2246 @option{cols} and @option{rows} specify that the console be sized to fit a text
2247 console with the given dimensions.
2249 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2251 Create a ring buffer with fixed size @option{size}.
2252 @var{size} must be a power of two, and defaults to @code{64K}).
2254 @item -chardev file ,id=@var{id} ,path=@var{path}
2256 Log all traffic received from the guest to a file.
2258 @option{path} specifies the path of the file to be opened. This file will be
2259 created if it does not already exist, and overwritten if it does. @option{path}
2262 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2264 Create a two-way connection to the guest. The behaviour differs slightly between
2265 Windows hosts and other hosts:
2267 On Windows, a single duplex pipe will be created at
2268 @file{\\.pipe\@option{path}}.
2270 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2271 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2272 received by the guest. Data written by the guest can be read from
2273 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2276 @option{path} forms part of the pipe path as described above. @option{path} is
2279 @item -chardev console ,id=@var{id}
2281 Send traffic from the guest to QEMU's standard output. @option{console} does not
2284 @option{console} is only available on Windows hosts.
2286 @item -chardev serial ,id=@var{id} ,path=@option{path}
2288 Send traffic from the guest to a serial device on the host.
2290 On Unix hosts serial will actually accept any tty device,
2291 not only serial lines.
2293 @option{path} specifies the name of the serial device to open.
2295 @item -chardev pty ,id=@var{id}
2297 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2298 not take any options.
2300 @option{pty} is not available on Windows hosts.
2302 @item -chardev stdio ,id=@var{id} [,signal=on|off]
2303 Connect to standard input and standard output of the QEMU process.
2305 @option{signal} controls if signals are enabled on the terminal, that includes
2306 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2307 default, use @option{signal=off} to disable it.
2309 @option{stdio} is not available on Windows hosts.
2311 @item -chardev braille ,id=@var{id}
2313 Connect to a local BrlAPI server. @option{braille} does not take any options.
2315 @item -chardev tty ,id=@var{id} ,path=@var{path}
2317 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2318 DragonFlyBSD hosts. It is an alias for @option{serial}.
2320 @option{path} specifies the path to the tty. @option{path} is required.
2322 @item -chardev parallel ,id=@var{id} ,path=@var{path}
2323 @itemx -chardev parport ,id=@var{id} ,path=@var{path}
2325 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2327 Connect to a local parallel port.
2329 @option{path} specifies the path to the parallel port device. @option{path} is
2332 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2334 @option{spicevmc} is only available when spice support is built in.
2336 @option{debug} debug level for spicevmc
2338 @option{name} name of spice channel to connect to
2340 Connect to a spice virtual machine channel, such as vdiport.
2342 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2344 @option{spiceport} is only available when spice support is built in.
2346 @option{debug} debug level for spicevmc
2348 @option{name} name of spice port to connect to
2350 Connect to a spice port, allowing a Spice client to handle the traffic
2351 identified by a name (preferably a fqdn).
2359 DEFHEADING(Device URL Syntax:)
2362 In addition to using normal file images for the emulated storage devices,
2363 QEMU can also use networked resources such as iSCSI devices. These are
2364 specified using a special URL syntax.
2368 iSCSI support allows QEMU to access iSCSI resources directly and use as
2369 images for the guest storage. Both disk and cdrom images are supported.
2371 Syntax for specifying iSCSI LUNs is
2372 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2374 By default qemu will use the iSCSI initiator-name
2375 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2376 line or a configuration file.
2378 Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2379 stalled requests and force a reestablishment of the session. The timeout
2380 is specified in seconds. The default is 0 which means no timeout. Libiscsi
2381 1.15.0 or greater is required for this feature.
2383 Example (without authentication):
2385 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2386 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2387 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2390 Example (CHAP username/password via URL):
2392 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2395 Example (CHAP username/password via environment variables):
2397 LIBISCSI_CHAP_USERNAME="user
" \
2398 LIBISCSI_CHAP_PASSWORD="password
" \
2399 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2402 iSCSI support is an optional feature of QEMU and only available when
2403 compiled and linked against libiscsi.
2405 DEF("iscsi
", HAS_ARG, QEMU_OPTION_iscsi,
2406 "-iscsi
[user
=user
][,password
=password
]\n"
2407 " [,header
-digest
=CRC32C|CR32C
-NONE|NONE
-CRC32C|NONE
\n"
2408 " [,initiator
-name
=initiator
-iqn
][,id
=target
-iqn
]\n"
2409 " [,timeout
=timeout
]\n"
2410 " iSCSI session parameters
\n", QEMU_ARCH_ALL)
2413 iSCSI parameters such as username and password can also be specified via
2414 a configuration file. See qemu-doc for more information and examples.
2417 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2418 as Unix Domain Sockets.
2420 Syntax for specifying a NBD device using TCP
2421 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2423 Syntax for specifying a NBD device using Unix Domain Sockets
2424 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2429 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2432 Example for Unix Domain Sockets
2434 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2438 QEMU supports SSH (Secure Shell) access to remote disks.
2442 qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2443 qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2446 Currently authentication must be done using ssh-agent. Other
2447 authentication methods may be supported in future.
2450 Sheepdog is a distributed storage system for QEMU.
2451 QEMU supports using either local sheepdog devices or remote networked
2454 Syntax for specifying a sheepdog device
2456 sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2461 qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2464 See also @url{http://http://www.osrg.net/sheepdog/}.
2467 GlusterFS is an user space distributed file system.
2468 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2469 TCP, Unix Domain Sockets and RDMA transport protocols.
2471 Syntax for specifying a VM disk image on GlusterFS volume is
2473 gluster[+transport]://[server[:port]]/volname/image[?socket=...]
2479 qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img
2482 See also @url{http://www.gluster.org}.
2484 @item HTTP/HTTPS/FTP/FTPS/TFTP
2485 QEMU supports read-only access to files accessed over http(s), ftp(s) and tftp.
2487 Syntax using a single filename:
2489 <protocol>://[<username>[:<password>]@@]<host>/<path>
2495 'http', 'https', 'ftp', 'ftps', or 'tftp'.
2498 Optional username for authentication to the remote server.
2501 Optional password for authentication to the remote server.
2504 Address of the remote server.
2507 Path on the remote server, including any query string.
2510 The following options are also supported:
2513 The full URL when passing options to the driver explicitly.
2516 The amount of data to read ahead with each range request to the remote server.
2517 This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
2518 does not have a suffix, it will be assumed to be in bytes. The value must be a
2519 multiple of 512 bytes. It defaults to 256k.
2522 Whether to verify the remote server's certificate when connecting over SSL. It
2523 can have the value 'on' or 'off'. It defaults to 'on'.
2526 Send this cookie (it can also be a list of cookies separated by ';') with
2527 each outgoing request. Only supported when using protocols such as HTTP
2528 which support cookies, otherwise ignored.
2531 Set the timeout in seconds of the CURL connection. This timeout is the time
2532 that CURL waits for a response from the remote server to get the size of the
2533 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2536 Note that when passing options to qemu explicitly, @option{driver} is the value
2539 Example: boot from a remote Fedora 20 live ISO image
2541 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
2543 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
2546 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2547 writes, copy-on-read, and a readahead of 64k
2549 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
2551 qemu
-system
-x86_64
-drive file
=/tmp
/Fedora
-x86_64
-20-20131211.1-sda
.qcow2
,copy
-on
-read
=on
2554 Example
: boot from an image stored on a VMware vSphere server with a self
-signed
2555 certificate
using a local overlay
for writes
, a readahead of
64k and a timeout
2558 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
2560 qemu
-system
-x86_64
-drive file
=/tmp
/test
.qcow2
2568 DEFHEADING(Bluetooth(R
) options
:)
2573 DEF("bt", HAS_ARG
, QEMU_OPTION_bt
, \
2574 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2575 "-bt hci,host[:id]\n" \
2576 " use host's HCI with the given name\n" \
2577 "-bt hci[,vlan=n]\n" \
2578 " emulate a standard HCI in virtual scatternet 'n'\n" \
2579 "-bt vhci[,vlan=n]\n" \
2580 " add host computer to virtual scatternet 'n' using VHCI\n" \
2581 "-bt device:dev[,vlan=n]\n" \
2582 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2587 Defines the
function of the corresponding Bluetooth HCI
. -bt options
2588 are matched with the HCIs present
in the chosen machine type
. For
2589 example when emulating a machine with only one HCI built into it
, only
2590 the first @code
{-bt hci
[...]} option is valid and defines the HCI
's
2591 logic. The Transport Layer is decided by the machine type. Currently
2592 the machines @code{n800} and @code{n810} have one HCI and all other
2596 The following three types are recognized:
2600 (default) The corresponding Bluetooth HCI assumes no internal logic
2601 and will not respond to any HCI commands or emit events.
2603 @item -bt hci,host[:@var{id}]
2604 (@code{bluez} only) The corresponding HCI passes commands / events
2605 to / from the physical HCI identified by the name @var{id} (default:
2606 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2607 capable systems like Linux.
2609 @item -bt hci[,vlan=@var{n}]
2610 Add a virtual, standard HCI that will participate in the Bluetooth
2611 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2612 VLANs, devices inside a bluetooth network @var{n} can only communicate
2613 with other devices in the same network (scatternet).
2616 @item -bt vhci[,vlan=@var{n}]
2617 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2618 to the host bluetooth stack instead of to the emulated target. This
2619 allows the host and target machines to participate in a common scatternet
2620 and communicate. Requires the Linux @code{vhci} driver installed. Can
2621 be used as following:
2624 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2627 @item -bt device:@var{dev}[,vlan=@var{n}]
2628 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2629 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2634 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2644 DEFHEADING(TPM device options:)
2646 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2647 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2648 " use path to provide path to a character device; default is /dev/tpm0\n"
2649 " use cancel-path to provide path to TPM's cancel sysfs entry
; if\n"
2650 " not provided it will be searched
for in /sys
/class/misc
/tpm?
/device
\n",
2654 The general form of a TPM device option is:
2657 @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
2659 Backend type must be:
2660 @option{passthrough}.
2662 The specific backend type will determine the applicable options.
2663 The @code{-tpmdev} option creates the TPM backend and requires a
2664 @code{-device} option that specifies the TPM frontend interface model.
2666 Options to each backend are described below.
2668 Use 'help' to print all available TPM backend types.
2673 @item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
2675 (Linux-host only) Enable access to the host's TPM using the passthrough
2678 @option{path} specifies the path to the host's TPM device, i.e., on
2679 a Linux host this would be @code{/dev/tpm0}.
2680 @option{path} is optional and by default @code{/dev/tpm0} is used.
2682 @option{cancel-path} specifies the path to the host TPM device's sysfs
2683 entry allowing for cancellation of an ongoing TPM command.
2684 @option{cancel-path} is optional and by default QEMU will search for the
2687 Some notes about using the host's TPM with the passthrough driver:
2689 The TPM device accessed by the passthrough driver must not be
2690 used by any other application on the host.
2692 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2693 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2694 TPM again and may therefore not show a TPM-specific menu that would
2695 otherwise allow the user to configure the TPM, e.g., allow the user to
2696 enable/disable or activate/deactivate the TPM.
2697 Further, if TPM ownership is released from within a VM then the host's TPM
2698 will get disabled and deactivated. To enable and activate the
2699 TPM again afterwards, the host has to be rebooted and the user is
2700 required to enter the firmware's menu to enable and activate the TPM.
2701 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2703 To create a passthrough TPM use the following two options:
2705 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2707 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2708 @code{tpmdev=tpm0} in the device option.
2718 DEFHEADING(Linux/Multiboot boot specific:)
2721 When using these options, you can use a given Linux or Multiboot
2722 kernel without installing it in the disk image. It can be useful
2723 for easier testing of various kernels.
2728 DEF("kernel
", HAS_ARG, QEMU_OPTION_kernel, \
2729 "-kernel bzImage use
'bzImage' as kernel image
\n", QEMU_ARCH_ALL)
2731 @item -kernel @var{bzImage}
2733 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2734 or in multiboot format.
2737 DEF("append
", HAS_ARG, QEMU_OPTION_append, \
2738 "-append cmdline use
'cmdline' as kernel command line
\n", QEMU_ARCH_ALL)
2740 @item -append @var{cmdline}
2742 Use @var{cmdline} as kernel command line
2745 DEF("initrd
", HAS_ARG, QEMU_OPTION_initrd, \
2746 "-initrd file use
'file' as initial ram disk
\n", QEMU_ARCH_ALL)
2748 @item -initrd @var{file}
2750 Use @var{file} as initial ram disk.
2752 @item -initrd "@
var{file1
} arg
=foo
,@
var{file2
}"
2754 This syntax is only available with multiboot.
2756 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2760 DEF("dtb
", HAS_ARG, QEMU_OPTION_dtb, \
2761 "-dtb file use
'file' as device tree image
\n", QEMU_ARCH_ALL)
2763 @item -dtb @var{file}
2765 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2774 DEFHEADING(Debug/Expert options:)
2779 DEF("fw_cfg
", HAS_ARG, QEMU_OPTION_fwcfg,
2780 "-fw_cfg
[name
=]<name
>,file
=<file
>\n"
2781 " add named fw_cfg entry from file
\n"
2782 "-fw_cfg
[name
=]<name
>,string
=<str
>\n"
2783 " add named fw_cfg entry from string
\n",
2786 @item -fw_cfg [name=]@var{name},file=@var{file}
2788 Add named fw_cfg entry from file. @var{name} determines the name of
2789 the entry in the fw_cfg file directory exposed to the guest.
2791 @item -fw_cfg [name=]@var{name},string=@var{str}
2792 Add named fw_cfg entry from string.
2795 DEF("serial
", HAS_ARG, QEMU_OPTION_serial, \
2796 "-serial dev redirect the serial port to char device
'dev'\n",
2799 @item -serial @var{dev}
2801 Redirect the virtual serial port to host character device
2802 @var{dev}. The default device is @code{vc} in graphical mode and
2803 @code{stdio} in non graphical mode.
2805 This option can be used several times to simulate up to 4 serial
2808 Use @code{-serial none} to disable all serial ports.
2810 Available character devices are:
2812 @item vc[:@var{W}x@var{H}]
2813 Virtual console. Optionally, a width and height can be given in pixel with
2817 It is also possible to specify width or height in characters:
2822 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
2824 No device is allocated.
2827 @item chardev:@var{id}
2828 Use a named character device defined with the @code{-chardev} option.
2830 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
2831 parameters are set according to the emulated ones.
2832 @item /dev/parport@var{N}
2833 [Linux only, parallel port only] Use host parallel port
2834 @var{N}. Currently SPP and EPP parallel port features can be used.
2835 @item file:@var{filename}
2836 Write output to @var{filename}. No character can be read.
2838 [Unix only] standard input/output
2839 @item pipe:@var{filename}
2840 name pipe @var{filename}
2842 [Windows only] Use host serial port @var{n}
2843 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
2844 This implements UDP Net Console.
2845 When @var{remote_host} or @var{src_ip} are not specified
2846 they default to @code{0.0.0.0}.
2847 When not using a specified @var{src_port} a random port is automatically chosen.
2849 If you just want a simple readonly console you can use @code{netcat} or
2850 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
2851 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
2852 will appear in the netconsole session.
2854 If you plan to send characters back via netconsole or you want to stop
2855 and start QEMU a lot of times, you should have QEMU use the same
2856 source port each time by using something like @code{-serial
2857 udp::4555@@:4556} to QEMU. Another approach is to use a patched
2858 version of netcat which can listen to a TCP port and send and receive
2859 characters via udp. If you have a patched version of netcat which
2860 activates telnet remote echo and single char transfer, then you can
2861 use the following options to step up a netcat redirector to allow
2862 telnet on port 5555 to access the QEMU port.
2865 -serial udp::4555@@:4556
2866 @item netcat options:
2867 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
2868 @item telnet options:
2872 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
2873 The TCP Net Console has two modes of operation. It can send the serial
2874 I/O to a location or wait for a connection from a location. By default
2875 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
2876 the @var{server} option QEMU will wait for a client socket application
2877 to connect to the port before continuing, unless the @code{nowait}
2878 option was specified. The @code{nodelay} option disables the Nagle buffering
2879 algorithm. The @code{reconnect} option only applies if @var{noserver} is
2880 set, if the connection goes down it will attempt to reconnect at the
2881 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
2882 one TCP connection at a time is accepted. You can use @code{telnet} to
2883 connect to the corresponding character device.
2885 @item Example to send tcp console to 192.168.0.2 port 4444
2886 -serial tcp:192.168.0.2:4444
2887 @item Example to listen and wait on port 4444 for connection
2888 -serial tcp::4444,server
2889 @item Example to not wait and listen on ip 192.168.0.100 port 4444
2890 -serial tcp:192.168.0.100:4444,server,nowait
2893 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
2894 The telnet protocol is used instead of raw tcp sockets. The options
2895 work the same as if you had specified @code{-serial tcp}. The
2896 difference is that the port acts like a telnet server or client using
2897 telnet option negotiation. This will also allow you to send the
2898 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
2899 sequence. Typically in unix telnet you do it with Control-] and then
2900 type "send
break" followed by pressing the enter key.
2902 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
2903 A unix domain socket is used instead of a tcp socket. The option works the
2904 same as if you had specified @code{-serial tcp} except the unix domain socket
2905 @var{path} is used for connections.
2907 @item mon:@var{dev_string}
2908 This is a special option to allow the monitor to be multiplexed onto
2909 another serial port. The monitor is accessed with key sequence of
2910 @key{Control-a} and then pressing @key{c}.
2911 @var{dev_string} should be any one of the serial devices specified
2912 above. An example to multiplex the monitor onto a telnet server
2913 listening on port 4444 would be:
2915 @item -serial mon:telnet::4444,server,nowait
2917 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
2918 QEMU any more but will be passed to the guest instead.
2921 Braille device. This will use BrlAPI to display the braille output on a real
2925 Three button serial mouse. Configure the guest to use Microsoft protocol.
2929 DEF("parallel
", HAS_ARG, QEMU_OPTION_parallel, \
2930 "-parallel dev redirect the parallel port to char device
'dev'\n",
2933 @item -parallel @var{dev}
2935 Redirect the virtual parallel port to host device @var{dev} (same
2936 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
2937 be used to use hardware devices connected on the corresponding host
2940 This option can be used several times to simulate up to 3 parallel
2943 Use @code{-parallel none} to disable all parallel ports.
2946 DEF("monitor
", HAS_ARG, QEMU_OPTION_monitor, \
2947 "-monitor dev redirect the monitor to char device
'dev'\n",
2950 @item -monitor @var{dev}
2952 Redirect the monitor to host device @var{dev} (same devices as the
2954 The default device is @code{vc} in graphical mode and @code{stdio} in
2956 Use @code{-monitor none} to disable the default monitor.
2958 DEF("qmp
", HAS_ARG, QEMU_OPTION_qmp, \
2959 "-qmp dev like
-monitor but opens
in 'control' mode
\n",
2962 @item -qmp @var{dev}
2964 Like -monitor but opens in 'control' mode.
2966 DEF("qmp
-pretty
", HAS_ARG, QEMU_OPTION_qmp_pretty, \
2967 "-qmp
-pretty dev like
-qmp but uses pretty JSON formatting
\n",
2970 @item -qmp-pretty @var{dev}
2972 Like -qmp but uses pretty JSON formatting.
2975 DEF("mon
", HAS_ARG, QEMU_OPTION_mon, \
2976 "-mon
[chardev
=]name
[,mode
=readline|control
][,default]\n", QEMU_ARCH_ALL)
2978 @item -mon [chardev=]name[,mode=readline|control][,default]
2980 Setup monitor on chardev @var{name}.
2983 DEF("debugcon
", HAS_ARG, QEMU_OPTION_debugcon, \
2984 "-debugcon dev redirect the debug console to char device
'dev'\n",
2987 @item -debugcon @var{dev}
2989 Redirect the debug console to host device @var{dev} (same devices as the
2990 serial port). The debug console is an I/O port which is typically port
2991 0xe9; writing to that I/O port sends output to this device.
2992 The default device is @code{vc} in graphical mode and @code{stdio} in
2996 DEF("pidfile
", HAS_ARG, QEMU_OPTION_pidfile, \
2997 "-pidfile file write PID to
'file'\n", QEMU_ARCH_ALL)
2999 @item -pidfile @var{file}
3001 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3005 DEF("singlestep
", 0, QEMU_OPTION_singlestep, \
3006 "-singlestep always run
in singlestep mode
\n", QEMU_ARCH_ALL)
3010 Run the emulation in single step mode.
3013 DEF("S
", 0, QEMU_OPTION_S, \
3014 "-S freeze CPU at
startup (use
'c' to start execution
)\n",
3019 Do not start CPU at startup (you must type 'c' in the monitor).
3022 DEF("realtime
", HAS_ARG, QEMU_OPTION_realtime,
3023 "-realtime
[mlock
=on|off
]\n"
3024 " run qemu with realtime features
\n"
3025 " mlock
=on|off controls mlock
support (default: on
)\n",
3028 @item -realtime mlock=on|off
3030 Run qemu with realtime features.
3031 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3032 (enabled by default).
3035 DEF("gdb
", HAS_ARG, QEMU_OPTION_gdb, \
3036 "-gdb dev wait
for gdb connection on
'dev'\n", QEMU_ARCH_ALL)
3038 @item -gdb @var{dev}
3040 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3041 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3042 stdio are reasonable use case. The latter is allowing to start QEMU from
3043 within gdb and establish the connection via a pipe:
3045 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3049 DEF("s
", 0, QEMU_OPTION_s, \
3050 "-s shorthand
for -gdb tcp
::" DEFAULT_GDBSTUB_PORT "\n",
3055 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3056 (@pxref{gdb_usage}).
3059 DEF("d
", HAS_ARG, QEMU_OPTION_d, \
3060 "-d item1
,... enable logging of specified
items (use
'-d help' for a list of log items
)\n",
3063 @item -d @var{item1}[,...]
3065 Enable logging of specified items. Use '-d help' for a list of log items.
3068 DEF("D
", HAS_ARG, QEMU_OPTION_D, \
3069 "-D logfile output log to
logfile (default stderr
)\n",
3072 @item -D @var{logfile}
3074 Output log in @var{logfile} instead of to stderr
3077 DEF("L
", HAS_ARG, QEMU_OPTION_L, \
3078 "-L path set the directory
for the BIOS
, VGA BIOS and keymaps
\n",
3083 Set the directory for the BIOS, VGA BIOS and keymaps.
3086 DEF("bios
", HAS_ARG, QEMU_OPTION_bios, \
3087 "-bios file set the filename
for the BIOS
\n", QEMU_ARCH_ALL)
3089 @item -bios @var{file}
3091 Set the filename for the BIOS.
3094 DEF("enable
-kvm
", 0, QEMU_OPTION_enable_kvm, \
3095 "-enable
-kvm enable KVM full virtualization support
\n", QEMU_ARCH_ALL)
3099 Enable KVM full virtualization support. This option is only available
3100 if KVM support is enabled when compiling.
3103 DEF("xen
-domid
", HAS_ARG, QEMU_OPTION_xen_domid,
3104 "-xen
-domid id specify xen guest domain id
\n", QEMU_ARCH_ALL)
3105 DEF("xen
-create
", 0, QEMU_OPTION_xen_create,
3106 "-xen
-create create domain
using xen hypercalls
, bypassing xend
\n"
3107 " warning
: should not be used when xend is
in use
\n",
3109 DEF("xen
-attach
", 0, QEMU_OPTION_xen_attach,
3110 "-xen
-attach attach to existing xen domain
\n"
3111 " xend will use
this when starting QEMU
\n",
3114 @item -xen-domid @var{id}
3116 Specify xen guest domain @var{id} (XEN only).
3119 Create domain using xen hypercalls, bypassing xend.
3120 Warning: should not be used when xend is in use (XEN only).
3123 Attach to existing xen domain.
3124 xend will use this when starting QEMU (XEN only).
3127 DEF("no
-reboot
", 0, QEMU_OPTION_no_reboot, \
3128 "-no
-reboot exit instead of rebooting
\n", QEMU_ARCH_ALL)
3132 Exit instead of rebooting.
3135 DEF("no
-shutdown
", 0, QEMU_OPTION_no_shutdown, \
3136 "-no
-shutdown stop before shutdown
\n", QEMU_ARCH_ALL)
3139 @findex -no-shutdown
3140 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3141 This allows for instance switching to monitor to commit changes to the
3145 DEF("loadvm
", HAS_ARG, QEMU_OPTION_loadvm, \
3146 "-loadvm
[tag|id
]\n" \
3147 " start right away with a saved
state (loadvm
in monitor
)\n",
3150 @item -loadvm @var{file}
3152 Start right away with a saved state (@code{loadvm} in monitor)
3156 DEF("daemonize
", 0, QEMU_OPTION_daemonize, \
3157 "-daemonize daemonize QEMU after initializing
\n", QEMU_ARCH_ALL)
3162 Daemonize the QEMU process after initialization. QEMU will not detach from
3163 standard IO until it is ready to receive connections on any of its devices.
3164 This option is a useful way for external programs to launch QEMU without having
3165 to cope with initialization race conditions.
3168 DEF("option
-rom
", HAS_ARG, QEMU_OPTION_option_rom, \
3169 "-option
-rom rom load a file
, rom
, into the option ROM space
\n",
3172 @item -option-rom @var{file}
3174 Load the contents of @var{file} as an option ROM.
3175 This option is useful to load things like EtherBoot.
3178 HXCOMM Silently ignored for compatibility
3179 DEF("clock
", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3181 HXCOMM Options deprecated by -rtc
3182 DEF("localtime
", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3183 DEF("startdate
", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3185 DEF("rtc
", HAS_ARG, QEMU_OPTION_rtc, \
3186 "-rtc
[base
=utc|localtime|date
][,clock
=host|rt|vm
][,driftfix
=none|slew
]\n" \
3187 " set the RTC base and clock
, enable drift fix
for clock
ticks (x86 only
)\n",
3192 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3194 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3195 UTC or local time, respectively. @code{localtime} is required for correct date in
3196 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3197 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3199 By default the RTC is driven by the host system time. This allows using of the
3200 RTC as accurate reference clock inside the guest, specifically if the host
3201 time is smoothly following an accurate external reference clock, e.g. via NTP.
3202 If you want to isolate the guest time from the host, you can set @option{clock}
3203 to @code{rt} instead. To even prevent it from progressing during suspension,
3204 you can set it to @code{vm}.
3206 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3207 specifically with Windows' ACPI HAL. This option will try to figure out how
3208 many timer interrupts were not processed by the Windows guest and will
3212 DEF("icount
", HAS_ARG, QEMU_OPTION_icount, \
3213 "-icount
[shift
=N|auto
][,align
=on|off
][,sleep
=no
,rr
=record|replay
,rrfile
=<filename
>]\n" \
3214 " enable virtual instruction counter with
2^N clock ticks per
\n" \
3215 " instruction
, enable aligning the host and virtual clocks
\n" \
3216 " or disable real time cpu sleeping
\n", QEMU_ARCH_ALL)
3218 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename}]
3220 Enable virtual instruction counter. The virtual cpu will execute one
3221 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3222 then the virtual cpu speed will be automatically adjusted to keep virtual
3223 time within a few seconds of real time.
3225 When the virtual cpu is sleeping, the virtual time will advance at default
3226 speed unless @option{sleep=no} is specified.
3227 With @option{sleep=no}, the virtual time will jump to the next timer deadline
3228 instantly whenever the virtual cpu goes to sleep mode and will not advance
3229 if no timer is enabled. This behavior give deterministic execution times from
3230 the guest point of view.
3232 Note that while this option can give deterministic behavior, it does not
3233 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3234 order cores with complex cache hierarchies. The number of instructions
3235 executed often has little or no correlation with actual performance.
3237 @option{align=on} will activate the delay algorithm which will try
3238 to synchronise the host clock and the virtual clock. The goal is to
3239 have a guest running at the real frequency imposed by the shift option.
3240 Whenever the guest clock is behind the host clock and if
3241 @option{align=on} is specified then we print a message to the user
3242 to inform about the delay.
3243 Currently this option does not work when @option{shift} is @code{auto}.
3244 Note: The sync algorithm will work for those shift values for which
3245 the guest clock runs ahead of the host clock. Typically this happens
3246 when the shift value is high (how high depends on the host machine).
3248 When @option{rr} option is specified deterministic record/replay is enabled.
3249 Replay log is written into @var{filename} file in record mode and
3250 read from this file in replay mode.
3253 DEF("watchdog
", HAS_ARG, QEMU_OPTION_watchdog, \
3254 "-watchdog model
\n" \
3255 " enable virtual hardware watchdog
[default=none
]\n",
3258 @item -watchdog @var{model}
3260 Create a virtual hardware watchdog device. Once enabled (by a guest
3261 action), the watchdog must be periodically polled by an agent inside
3262 the guest or else the guest will be restarted. Choose a model for
3263 which your guest has drivers.
3265 The @var{model} is the model of hardware watchdog to emulate. Use
3266 @code{-watchdog help} to list available hardware models. Only one
3267 watchdog can be enabled for a guest.
3269 The following models may be available:
3272 iBASE 700 is a very simple ISA watchdog with a single timer.
3274 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3275 dual-timer watchdog.
3277 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3278 (currently KVM only).
3282 DEF("watchdog
-action
", HAS_ARG, QEMU_OPTION_watchdog_action, \
3283 "-watchdog
-action reset|shutdown|poweroff|pause|debug|none
\n" \
3284 " action when watchdog fires
[default=reset
]\n",
3287 @item -watchdog-action @var{action}
3288 @findex -watchdog-action
3290 The @var{action} controls what QEMU will do when the watchdog timer
3293 @code{reset} (forcefully reset the guest).
3294 Other possible actions are:
3295 @code{shutdown} (attempt to gracefully shutdown the guest),
3296 @code{poweroff} (forcefully poweroff the guest),
3297 @code{pause} (pause the guest),
3298 @code{debug} (print a debug message and continue), or
3299 @code{none} (do nothing).
3301 Note that the @code{shutdown} action requires that the guest responds
3302 to ACPI signals, which it may not be able to do in the sort of
3303 situations where the watchdog would have expired, and thus
3304 @code{-watchdog-action shutdown} is not recommended for production use.
3309 @item -watchdog i6300esb -watchdog-action pause
3310 @itemx -watchdog ib700
3314 DEF("echr
", HAS_ARG, QEMU_OPTION_echr, \
3315 "-echr chr set terminal escape character instead of ctrl
-a
\n",
3319 @item -echr @var{numeric_ascii_value}
3321 Change the escape character used for switching to the monitor when using
3322 monitor and serial sharing. The default is @code{0x01} when using the
3323 @code{-nographic} option. @code{0x01} is equal to pressing
3324 @code{Control-a}. You can select a different character from the ascii
3325 control keys where 1 through 26 map to Control-a through Control-z. For
3326 instance you could use the either of the following to change the escape
3327 character to Control-t.
3334 DEF("virtioconsole
", HAS_ARG, QEMU_OPTION_virtiocon, \
3335 "-virtioconsole c
\n" \
3336 " set virtio console
\n", QEMU_ARCH_ALL)
3338 @item -virtioconsole @var{c}
3339 @findex -virtioconsole
3342 This option is maintained for backward compatibility.
3344 Please use @code{-device virtconsole} for the new way of invocation.
3347 DEF("show
-cursor
", 0, QEMU_OPTION_show_cursor, \
3348 "-show
-cursor show cursor
\n", QEMU_ARCH_ALL)
3351 @findex -show-cursor
3355 DEF("tb
-size
", HAS_ARG, QEMU_OPTION_tb_size, \
3356 "-tb
-size n set TB size
\n", QEMU_ARCH_ALL)
3358 @item -tb-size @var{n}
3363 DEF("incoming
", HAS_ARG, QEMU_OPTION_incoming, \
3364 "-incoming tcp
:[host
]:port
[,to
=maxport
][,ipv4
][,ipv6
]\n" \
3365 "-incoming rdma
:host
:port
[,ipv4
][,ipv6
]\n" \
3366 "-incoming unix
:socketpath
\n" \
3367 " prepare
for incoming migration
, listen on
\n" \
3368 " specified protocol and socket address
\n" \
3369 "-incoming fd
:fd
\n" \
3370 "-incoming exec
:cmdline
\n" \
3371 " accept incoming migration on given file descriptor
\n" \
3372 " or from given external command
\n" \
3373 "-incoming defer
\n" \
3374 " wait
for the URI to be specified via migrate_incoming
\n",
3377 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3378 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3380 Prepare for incoming migration, listen on a given tcp port.
3382 @item -incoming unix:@var{socketpath}
3383 Prepare for incoming migration, listen on a given unix socket.
3385 @item -incoming fd:@var{fd}
3386 Accept incoming migration from a given filedescriptor.
3388 @item -incoming exec:@var{cmdline}
3389 Accept incoming migration as an output from specified external command.
3391 @item -incoming defer
3392 Wait for the URI to be specified via migrate_incoming. The monitor can
3393 be used to change settings (such as migration parameters) prior to issuing
3394 the migrate_incoming to allow the migration to begin.
3397 DEF("nodefaults
", 0, QEMU_OPTION_nodefaults, \
3398 "-nodefaults don
't create default devices\n", QEMU_ARCH_ALL)
3402 Don't create
default devices
. Normally
, QEMU sets the
default devices like serial
3403 port
, parallel port
, virtual console
, monitor device
, VGA adapter
, floppy and
3404 CD
-ROM drive and others
. The @code
{-nodefaults
} option will disable all those
3409 DEF("chroot", HAS_ARG
, QEMU_OPTION_chroot
, \
3410 "-chroot dir chroot to dir just before starting the VM\n",
3414 @item
-chroot @
var{dir
}
3416 Immediately before starting guest execution
, chroot to the specified
3417 directory
. Especially useful
in combination with
-runas
.
3421 DEF("runas", HAS_ARG
, QEMU_OPTION_runas
, \
3422 "-runas user change to user id user just before starting the VM\n",
3426 @item
-runas @
var{user
}
3428 Immediately before starting guest execution
, drop root privileges
, switching
3429 to the specified user
.
3432 DEF("prom-env", HAS_ARG
, QEMU_OPTION_prom_env
,
3433 "-prom-env variable=value\n"
3434 " set OpenBIOS nvram variables\n",
3435 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
3437 @item
-prom
-env @
var{variable
}=@
var{value
}
3439 Set OpenBIOS nvram @
var{variable
} to given @
var{value
} (PPC
, SPARC only
).
3441 DEF("semihosting", 0, QEMU_OPTION_semihosting
,
3442 "-semihosting semihosting mode\n",
3443 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3447 @findex
-semihosting
3448 Enable semihosting
mode (ARM
, M68K
, Xtensa
, MIPS only
).
3450 DEF("semihosting-config", HAS_ARG
, QEMU_OPTION_semihosting_config
,
3451 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3452 " semihosting configuration\n",
3453 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3456 @item
-semihosting
-config
[enable
=on|off
][,target
=native|gdb|auto
][,arg
=str
[,...]]
3457 @findex
-semihosting
-config
3458 Enable and configure
semihosting (ARM
, M68K
, Xtensa
, MIPS only
).
3460 @item target
=@code
{native|gdb|auto
}
3461 Defines where the semihosting calls will be addressed
, to
QEMU (@code
{native
})
3462 or to
GDB (@code
{gdb
}). The
default is @code
{auto
}, which means @code
{gdb
}
3463 during debug sessions and @code
{native
} otherwise
.
3464 @item arg
=@
var{str1
},arg
=@
var{str2
},...
3465 Allows the user to pass input arguments
, and can be used multiple times to build
3466 up a list
. The old
-style @code
{-kernel
}/@code
{-append
} method of passing a
3467 command line is still supported
for backward compatibility
. If both the
3468 @code
{--semihosting
-config arg
} and the @code
{-kernel
}/@code
{-append
} are
3469 specified
, the former is passed to semihosting as it always takes precedence
.
3472 DEF("old-param", 0, QEMU_OPTION_old_param
,
3473 "-old-param old param mode\n", QEMU_ARCH_ARM
)
3476 @findex
-old
-param (ARM
)
3477 Old param
mode (ARM only
).
3480 DEF("sandbox", HAS_ARG
, QEMU_OPTION_sandbox
, \
3481 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n",
3484 @item
-sandbox @
var{arg
}
3486 Enable Seccomp mode
2 system call filter
. 'on' will enable syscall filtering and
'off' will
3487 disable it
. The
default is
'off'.
3490 DEF("readconfig", HAS_ARG
, QEMU_OPTION_readconfig
,
3491 "-readconfig <file>\n", QEMU_ARCH_ALL
)
3493 @item
-readconfig @
var{file
}
3495 Read device configuration from @
var{file
}. This approach is useful when you want to spawn
3496 QEMU process with many command line options but you don
't want to exceed the command line
3499 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3500 "-writeconfig <file>\n"
3501 " read/write config file\n", QEMU_ARCH_ALL)
3503 @item -writeconfig @var{file}
3504 @findex -writeconfig
3505 Write device configuration to @var{file}. The @var{file} can be either filename to save
3506 command line and device configuration into file or dash @code{-}) character to print the
3507 output to stdout. This can be later used as input file for @code{-readconfig} option.
3509 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
3511 " do not load default config files at startup\n",
3515 @findex -nodefconfig
3516 Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
3517 The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
3519 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3521 " do not load user-provided config files at startup\n",
3524 @item -no-user-config
3525 @findex -no-user-config
3526 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3527 config files on @var{sysconfdir}, but won't make it skip the QEMU
-provided config
3528 files from @
var{datadir
}.
3530 DEF("trace", HAS_ARG
, QEMU_OPTION_trace
,
3531 "-trace [events=<file>][,file=<file>]\n"
3532 " specify tracing options\n",
3535 HXCOMM This line is not accurate
, as some sub
-options are backend
-specific but
3536 HXCOMM HX does not support conditional compilation of text
.
3537 @item
-trace [events
=@
var{file
}][,file
=@
var{file
}]
3540 Specify tracing options
.
3543 @item events
=@
var{file
}
3544 Immediately enable events listed
in @
var{file
}.
3545 The file must contain one event
name (as listed
in the @
var{trace-events
} file
)
3547 This option is only available
if QEMU has been compiled with
3548 either @
var{simple
} or @
var{stderr
} tracing backend
.
3549 @item file
=@
var{file
}
3550 Log output traces to @
var{file
}.
3552 This option is only available
if QEMU has been compiled with
3553 the @
var{simple
} tracing backend
.
3558 DEF("qtest", HAS_ARG
, QEMU_OPTION_qtest
, "", QEMU_ARCH_ALL
)
3559 DEF("qtest-log", HAS_ARG
, QEMU_OPTION_qtest_log
, "", QEMU_ARCH_ALL
)
3562 DEF("enable-fips", 0, QEMU_OPTION_enablefips
,
3563 "-enable-fips enable FIPS 140-2 compliance\n",
3568 @findex
-enable
-fips
3569 Enable FIPS
140-2 compliance mode
.
3572 HXCOMM Deprecated by
-machine accel
=tcg property
3573 DEF("no-kvm", 0, QEMU_OPTION_no_kvm
, "", QEMU_ARCH_I386
)
3575 HXCOMM Deprecated by kvm
-pit driver properties
3576 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection
,
3579 HXCOMM
Deprecated (ignored
)
3580 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit
, "", QEMU_ARCH_I386
)
3582 HXCOMM Deprecated by
-machine kernel_irqchip
=on|off property
3583 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip
, "", QEMU_ARCH_I386
)
3585 HXCOMM
Deprecated (ignored
)
3586 DEF("tdf", 0, QEMU_OPTION_tdf
,"", QEMU_ARCH_ALL
)
3588 DEF("msg", HAS_ARG
, QEMU_OPTION_msg
,
3589 "-msg timestamp[=on|off]\n"
3590 " change the format of messages\n"
3591 " on|off controls leading timestamps (default:on)\n",
3594 @item
-msg timestamp
[=on|off
]
3596 prepend a timestamp to each log message
.(default:on
)
3599 DEF("dump-vmstate", HAS_ARG
, QEMU_OPTION_dump_vmstate
,
3600 "-dump-vmstate <file>\n"
3601 " Output vmstate information in JSON format to file.\n"
3602 " Use the scripts/vmstate-static-checker.py file to\n"
3603 " check for possible regressions in migration code\n"
3604 " by comparing two such vmstate dumps.\n",
3607 @item
-dump
-vmstate @
var{file
}
3608 @findex
-dump
-vmstate
3609 Dump json
-encoded vmstate information
for current machine type to file
3613 DEFHEADING(Generic object creation
)
3615 DEF("object", HAS_ARG
, QEMU_OPTION_object
,
3616 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3617 " create a new object of type TYPENAME setting properties\n"
3618 " in the order they are specified. Note that the 'id'\n"
3619 " property must be set. These objects are placed in the\n"
3620 " '/objects' path.\n",
3623 @item
-object @
var{typename
}[,@
var{prop1
}=@
var{value1
},...]
3625 Create a
new object of type @
var{typename
} setting properties
3626 in the order they are specified
. Note that the
'id'
3627 property must be set
. These objects are placed
in the
3632 @item
-object memory
-backend
-file
,id
=@
var{id
},size
=@
var{size
},mem
-path
=@
var{dir
},share
=@
var{on|off
}
3634 Creates a memory file backend object
, which can be used to back
3635 the guest RAM with huge pages
. The @option
{id
} parameter is a
3636 unique ID that will be used to reference
this memory region
3637 when configuring the @option
{-numa
} argument
. The @option
{size
}
3638 option provides the size of the memory region
, and accepts
3639 common suffixes
, eg @option
{500M
}. The @option
{mem
-path
} provides
3640 the path to either a shared memory or huge page filesystem mount
.
3641 The @option
{share
} boolean option determines whether the memory
3642 region is marked as
private to QEMU
, or shared
. The latter allows
3643 a co
-operating external process to access the QEMU memory region
.
3645 @item
-object rng
-random
,id
=@
var{id
},filename
=@
var{/dev
/random
}
3647 Creates a random number generator backend which obtains entropy from
3648 a device on the host
. The @option
{id
} parameter is a unique ID that
3649 will be used to reference
this entropy backend from the @option
{virtio
-rng
}
3650 device
. The @option
{filename
} parameter specifies which file to obtain
3651 entropy from and
if omitted defaults to @option
{/dev
/random
}.
3653 @item
-object rng
-egd
,id
=@
var{id
},chardev
=@
var{chardevid
}
3655 Creates a random number generator backend which obtains entropy from
3656 an external daemon running on the host
. The @option
{id
} parameter is
3657 a unique ID that will be used to reference
this entropy backend from
3658 the @option
{virtio
-rng
} device
. The @option
{chardev
} parameter is
3659 the unique ID of a character device backend that provides the connection
3662 @item
-object tls
-creds
-anon
,id
=@
var{id
},endpoint
=@
var{endpoint
},dir
=@
var{/path
/to
/cred
/dir
},verify
-peer
=@
var{on|off
}
3664 Creates a TLS anonymous credentials object
, which can be used to provide
3665 TLS support on network backends
. The @option
{id
} parameter is a unique
3666 ID which network backends will use to access the credentials
. The
3667 @option
{endpoint
} is either @option
{server
} or @option
{client
} depending
3668 on whether the QEMU network backend that uses the credentials will be
3669 acting as a client or as a server
. If @option
{verify
-peer
} is enabled
3670 (the
default) then once the handshake is completed
, the peer credentials
3671 will be verified
, though
this is a no
-op
for anonymous credentials
.
3673 The @
var{dir
} parameter tells QEMU where to find the credential
3674 files
. For server endpoints
, this directory may contain a file
3675 @
var{dh
-params
.pem
} providing diffie
-hellman parameters to use
3676 for the TLS server
. If the file is missing
, QEMU will generate
3677 a set of DH parameters at startup
. This is a computationally
3678 expensive operation that consumes random pool entropy
, so it is
3679 recommended that a persistent set of parameters be generated
3682 @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
}
3684 Creates a TLS anonymous credentials object
, which can be used to provide
3685 TLS support on network backends
. The @option
{id
} parameter is a unique
3686 ID which network backends will use to access the credentials
. The
3687 @option
{endpoint
} is either @option
{server
} or @option
{client
} depending
3688 on whether the QEMU network backend that uses the credentials will be
3689 acting as a client or as a server
. If @option
{verify
-peer
} is enabled
3690 (the
default) then once the handshake is completed
, the peer credentials
3691 will be verified
. With x509 certificates
, this implies that the clients
3692 must be provided with valid client certificates too
.
3694 The @
var{dir
} parameter tells QEMU where to find the credential
3695 files
. For server endpoints
, this directory may contain a file
3696 @
var{dh
-params
.pem
} providing diffie
-hellman parameters to use
3697 for the TLS server
. If the file is missing
, QEMU will generate
3698 a set of DH parameters at startup
. This is a computationally
3699 expensive operation that consumes random pool entropy
, so it is
3700 recommended that a persistent set of parameters be generated
3703 For x509 certificate credentials the directory will contain further files
3704 providing the x509 certificates
. The certificates must be stored
3705 in PEM format
, in filenames @
var{ca
-cert
.pem
}, @
var{ca
-crl
.pem
} (optional
),
3706 @
var{server
-cert
.pem
} (only servers
), @
var{server
-key
.pem
} (only servers
),
3707 @
var{client
-cert
.pem
} (only clients
), and @
var{client
-key
.pem
} (only clients
).
3709 For the @
var{server
-key
.pem
} and @
var{client
-key
.pem
} files which
3710 contain sensitive
private keys
, it is possible to use an encrypted
3711 version by providing the @
var{passwordid
} parameter
. This provides
3712 the ID of a previously created @code
{secret
} object containing the
3713 password
for decryption
.
3715 @item
-object filter
-buffer
,id
=@
var{id
},netdev
=@
var{netdevid
},interval
=@
var{t
}[,queue
=@
var{all|rx|tx
}]
3717 Interval @
var{t
} can
't be 0, this filter batches the packet delivery: all
3718 packets arriving in a given interval on netdev @var{netdevid} are delayed
3719 until the end of the interval. Interval is in microseconds.
3721 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
3723 @option{all}: the filter is attached both to the receive and the transmit
3724 queue of the netdev (default).
3726 @option{rx}: the filter is attached to the receive queue of the netdev,
3727 where it will receive packets sent to the netdev.
3729 @option{tx}: the filter is attached to the transmit queue of the netdev,
3730 where it will receive packets sent by the netdev.
3732 @item -object filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}]
3734 Dump the network traffic on netdev @var{dev} to the file specified by
3735 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
3736 The file format is libpcap, so it can be analyzed with tools such as tcpdump
3739 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
3740 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
3742 Defines a secret to store a password, encryption key, or some other sensitive
3743 data. The sensitive data can either be passed directly via the @var{data}
3744 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
3745 parameter is insecure unless the sensitive data is encrypted.
3747 The sensitive data can be provided in raw format (the default), or base64.
3748 When encoded as JSON, the raw format only supports valid UTF-8 characters,
3749 so base64 is recommended for sending binary data. QEMU will convert from
3750 which ever format is provided to the format it needs internally. eg, an
3751 RBD password can be provided in raw format, even though it will be base64
3752 encoded when passed onto the RBD sever.
3754 For added protection, it is possible to encrypt the data associated with
3755 a secret using the AES-256-CBC cipher. Use of encryption is indicated
3756 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
3757 parameter provides the ID of a previously defined secret that contains
3758 the AES-256 decryption key. This key should be 32-bytes long and be
3759 base64 encoded. The @var{iv} parameter provides the random initialization
3760 vector used for encryption of this particular secret and should be a
3761 base64 encrypted string of the 32-byte IV.
3763 The simplest (insecure) usage is to provide the secret inline
3767 # $QEMU -object secret,id=sec0,data=letmein,format=raw
3771 The simplest secure usage is to provide the secret via a file
3773 # echo -n "letmein" > mypasswd.txt
3774 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
3776 For greater security, AES-256-CBC should be used. To illustrate usage,
3777 consider the openssl command line tool which can encrypt the data. Note
3778 that when encrypting, the plaintext must be padded to the cipher block
3779 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
3781 First a master key needs to be created in base64 encoding:
3784 # openssl rand -base64 32 > key.b64
3785 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
3788 Each secret to be encrypted needs to have a random initialization vector
3789 generated. These do not need to be kept secret
3792 # openssl rand -base64 16 > iv.b64
3793 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
3796 The secret to be defined can now be encrypted, in this case we're
3797 telling openssl to base64 encode the result
, but it could be left
3798 as raw bytes
if desired
.
3801 # SECRET
=$
(echo
-n
"letmein" |
3802 openssl enc
-aes
-256-cbc
-a
-K $KEY
-iv $IV
)
3805 When launching QEMU
, create a master secret pointing to @code
{key
.b64
}
3806 and specify that to be used to decrypt the user password
. Pass the
3807 contents of @code
{iv
.b64
} to the second secret
3811 -object secret
,id
=secmaster0
,format
=base64
,file
=key
.b64 \
3812 -object secret
,id
=sec0
,keyid
=secmaster0
,format
=base64
,\
3813 data
=$SECRET
,iv
=$
(<iv
.b64
)
3821 HXCOMM This is the last statement
. Insert
new options before
this line
!