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, hax or tcg (default: tcg)\n"
35 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n"
36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
37 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n"
38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
39 " mem-merge=on|off controls memory merge support (default: on)\n"
40 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
44 " nvdimm=on|off controls NVDIMM support (default=off)\n"
45 " enforce-config-section=on|off enforce configuration section migration (default=off)\n"
46 " s390-squash-mcss=on|off controls support for squashing into default css (default=off)\n",
49 @item
-machine
[type
=]@
var{name
}[,prop
=@
var{value
}[,...]]
51 Select the emulated machine by @
var{name
}. Use @code
{-machine help
} to list
54 For architectures which aim to support live migration compatibility
55 across releases
, each release will introduce a
new versioned machine
56 type
. For example
, the
2.8.0 release introduced machine types
57 ``pc
-i440fx
-2.8'' and ``pc
-q35
-2.8'' for the x86_64
/i686 architectures
.
59 To allow live migration of guests from QEMU version
2.8.0, to QEMU
60 version
2.9.0, the
2.9.0 version must support the ``pc
-i440fx
-2.8''
61 and ``pc
-q35
-2.8'' machines too
. To allow users live migrating VMs
62 to skip multiple intermediate releases when upgrading
, new releases
63 of QEMU will support machine types from many previous versions
.
65 Supported machine properties are
:
67 @item accel
=@
var{accels1
}[:@
var{accels2
}[:...]]
68 This is used to enable an accelerator
. Depending on the target architecture
,
69 kvm
, xen
, hax or tcg can be available
. By
default, tcg is used
. If there is
70 more than one accelerator specified
, the next one is used
if the previous one
72 @item kernel_irqchip
=on|off
73 Controls
in-kernel irqchip support
for the chosen accelerator when available
.
74 @item gfx_passthru
=on|off
75 Enables IGD GFX passthrough support
for the chosen machine when available
.
76 @item vmport
=on|off|auto
77 Enables emulation of VMWare IO port
, for vmmouse etc
. auto says to select the
78 value based on accel
. For accel
=xen the
default is off otherwise the
default
80 @item kvm_shadow_mem
=size
81 Defines the size of the KVM shadow MMU
.
82 @item dump
-guest
-core
=on|off
83 Include guest memory
in a core dump
. The
default is on
.
84 @item mem
-merge
=on|off
85 Enables or disables memory merge support
. This feature
, when supported by
86 the host
, de
-duplicates identical memory pages among VMs instances
88 @item aes
-key
-wrap
=on|off
89 Enables or disables AES key wrapping support on s390
-ccw hosts
. This feature
90 controls whether AES wrapping keys will be created to allow
91 execution of AES cryptographic functions
. The
default is on
.
92 @item dea
-key
-wrap
=on|off
93 Enables or disables DEA key wrapping support on s390
-ccw hosts
. This feature
94 controls whether DEA wrapping keys will be created to allow
95 execution of DEA cryptographic functions
. The
default is on
.
97 Enables or disables NVDIMM support
. The
default is off
.
98 @item s390
-squash
-mcss
=on|off
99 Enables or disables squashing subchannels into the
default css
.
101 @item enforce
-config
-section
=on|off
102 If @option
{enforce
-config
-section
} is set to @
var{on
}, force migration
103 code to send configuration section even
if the machine
-type sets the
104 @option
{migration
.send
-configuration
} property to @
var{off
}.
105 NOTE
: this parameter is deprecated
. Please use @option
{-global
}
106 @option
{migration
.send
-configuration
}=@
var{on|off
} instead
.
110 HXCOMM Deprecated by
-machine
111 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
113 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
114 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
116 @item
-cpu @
var{model
}
118 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
121 DEF("accel", HAS_ARG
, QEMU_OPTION_accel
,
122 "-accel [accel=]accelerator[,thread=single|multi]\n"
123 " select accelerator (kvm, xen, hax or tcg; use 'help' for a list)\n"
124 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL
)
126 @item
-accel @
var{name
}[,prop
=@
var{value
}[,...]]
128 This is used to enable an accelerator
. Depending on the target architecture
,
129 kvm
, xen
, hax or tcg can be available
. By
default, tcg is used
. If there is
130 more than one accelerator specified
, the next one is used
if the previous one
133 @item thread
=single|multi
134 Controls number of TCG threads
. When the TCG is multi
-threaded there will be one
135 thread per vCPU therefor taking advantage of additional host cores
. The
default
136 is to enable multi
-threading where both the back
-end and front
-ends support it and
137 no incompatible TCG features have been
enabled (e
.g
. icount
/replay
).
141 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
142 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
143 " set the number of CPUs to 'n' [default=1]\n"
144 " maxcpus= maximum number of total cpus, including\n"
145 " offline CPUs for hotplug, etc\n"
146 " cores= number of CPU cores on one socket\n"
147 " threads= number of threads on one CPU core\n"
148 " sockets= number of discrete sockets in the system\n",
151 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
153 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
154 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
156 For the PC target
, the number of @
var{cores
} per socket
, the number
157 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
158 specified
. Missing values will be computed
. If any on the three values is
159 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
160 specifies the maximum number of hotpluggable CPUs
.
163 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
164 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
165 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
166 "-numa dist,src=source,dst=destination,val=distance\n", QEMU_ARCH_ALL
)
168 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{firstcpu
}[-@
var{lastcpu
}]][,nodeid
=@
var{node
}]
169 @itemx
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{firstcpu
}[-@
var{lastcpu
}]][,nodeid
=@
var{node
}]
170 @itemx
-numa dist
,src
=@
var{source
},dst
=@
var{destination
},val
=@
var{distance
}
171 @itemx
-numa cpu
,node
-id
=@
var{node
}[,socket
-id
=@
var{x
}][,core
-id
=@
var{y
}][,thread
-id
=@
var{z
}]
173 Define a NUMA node and assign RAM and VCPUs to it
.
174 Set the NUMA distance from a source node to a destination node
.
176 Legacy VCPU assignment uses @samp
{cpus
} option where
177 @
var{firstcpu
} and @
var{lastcpu
} are CPU indexes
. Each
178 @samp
{cpus
} option represent a contiguous range of CPU indexes
179 (or a single VCPU
if @
var{lastcpu
} is omitted
). A non
-contiguous
180 set of VCPUs can be represented by providing multiple @samp
{cpus
}
181 options
. If @samp
{cpus
} is omitted on all nodes
, VCPUs are automatically
184 For example
, the following option assigns VCPUs
0, 1, 2 and
5 to
187 -numa node
,cpus
=0-2,cpus
=5
190 @samp
{cpu
} option is a
new alternative to @samp
{cpus
} option
191 which uses @samp
{socket
-id|core
-id|thread
-id
} properties to assign
192 CPU objects to a @
var{node
} using topology layout properties of CPU
.
193 The set of properties is machine specific
, and depends on used
194 machine type
/@samp
{smp
} options
. It could be queried with
195 @samp
{hotpluggable
-cpus
} monitor command
.
196 @samp
{node
-id
} property specifies @
var{node
} to which CPU object
197 will be assigned
, it
's required for @var{node} to be declared
198 with @samp{node} option before it's used with @samp
{cpu
} option
.
203 -smp
1,sockets
=2,maxcpus
=2 \
204 -numa node
,nodeid
=0 -numa node
,nodeid
=1 \
205 -numa cpu
,node
-id
=0,socket
-id
=0 -numa cpu
,node
-id
=1,socket
-id
=1
208 @samp
{mem
} assigns a given RAM amount to a node
. @samp
{memdev
}
209 assigns RAM from a given memory backend device to a node
. If
210 @samp
{mem
} and @samp
{memdev
} are omitted
in all nodes
, RAM is
211 split equally between them
.
213 @samp
{mem
} and @samp
{memdev
} are mutually exclusive
. Furthermore
,
214 if one node uses @samp
{memdev
}, all of them have to use it
.
216 @
var{source
} and @
var{destination
} are NUMA node IDs
.
217 @
var{distance
} is the NUMA distance from @
var{source
} to @
var{destination
}.
218 The distance from a node to itself is always
10. If any pair of nodes is
219 given a distance
, then all pairs must be given distances
. Although
, when
220 distances are only given
in one direction
for each pair of nodes
, then
221 the distances
in the opposite directions are assumed to be the same
. If
,
222 however
, an asymmetrical pair of distances is given
for even one node
223 pair
, then all node pairs must be provided distance values
for both
224 directions
, even when they are symmetrical
. When a node is unreachable
225 from another node
, set the pair
's distance to 255.
227 Note that the -@option{numa} option doesn't allocate any of the
228 specified resources
, it just assigns existing resources to NUMA
229 nodes
. This means that one still has to use the @option
{-m
},
230 @option
{-smp
} options to allocate RAM and VCPUs respectively
.
234 DEF("add-fd", HAS_ARG
, QEMU_OPTION_add_fd
,
235 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
236 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL
)
238 @item
-add
-fd fd
=@
var{fd
},set
=@
var{set
}[,opaque
=@
var{opaque
}]
241 Add a file descriptor to an fd set
. Valid options are
:
245 This option defines the file descriptor of which a duplicate is added to fd set
.
246 The file descriptor cannot be stdin
, stdout
, or stderr
.
248 This option defines the ID of the fd set to add the file descriptor to
.
249 @item opaque
=@
var{opaque
}
250 This option defines a free
-form string that can be used to describe @
var{fd
}.
253 You can open an image
using pre
-opened file descriptors from an fd set
:
256 -add
-fd fd
=3,set
=2,opaque
="rdwr:/path/to/file"
257 -add
-fd fd
=4,set
=2,opaque
="rdonly:/path/to/file"
258 -drive file
=/dev
/fdset
/2,index
=0,media
=disk
262 DEF("set", HAS_ARG
, QEMU_OPTION_set
,
263 "-set group.id.arg=value\n"
264 " set <arg> parameter for item <id> of type <group>\n"
265 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL
)
267 @item
-set @
var{group
}.@
var{id
}.@
var{arg
}=@
var{value
}
269 Set parameter @
var{arg
} for item @
var{id
} of type @
var{group
}
272 DEF("global", HAS_ARG
, QEMU_OPTION_global
,
273 "-global driver.property=value\n"
274 "-global driver=driver,property=property,value=value\n"
275 " set a global default for a driver property\n",
278 @item
-global @
var{driver
}.@
var{prop
}=@
var{value
}
279 @itemx
-global driver
=@
var{driver
},property
=@
var{property
},value
=@
var{value
}
281 Set
default value of @
var{driver
}'s property @var{prop} to @var{value}, e.g.:
284 qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
287 In particular, you can use this to set driver properties for devices which are
288 created automatically by the machine model. To create a device which is not
289 created automatically and set properties on it, use -@option{device}.
291 -global @var{driver}.@var{prop}=@var{value} is shorthand for -global
292 driver=@var{driver},property=@var{prop},value=@var{value}. The
293 longhand syntax works even when @var{driver} contains a dot.
296 DEF("boot", HAS_ARG, QEMU_OPTION_boot,
297 "-boot [order=drives][,once=drives][,menu=on|off]\n"
298 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
299 " 'drives
': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
300 " 'sp_name
': the file's name that would be passed to bios as logo picture
, if menu
=on
\n"
301 " 'sp_time': the period that splash picture last
if menu
=on
, unit is ms
\n"
302 " 'rb_timeout': the timeout before guest reboot when boot failed
, unit is ms
\n",
305 @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]
307 Specify boot order @var{drives} as a string of drive letters. Valid
308 drive letters depend on the target architecture. The x86 PC uses: a, b
309 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
310 from network adapter 1-4), hard disk boot is the default. To apply a
311 particular boot order only on the first startup, specify it via
312 @option{once}. Note that the @option{order} or @option{once} parameter
313 should not be used together with the @option{bootindex} property of
314 devices, since the firmware implementations normally do not support both
317 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
318 as firmware/BIOS supports them. The default is non-interactive boot.
320 A splash picture could be passed to bios, enabling user to show it as logo,
321 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
322 supports them. Currently Seabios for X86 system support it.
323 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
324 format(true color). The resolution should be supported by the SVGA mode, so
325 the recommended is 320x240, 640x480, 800x640.
327 A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
328 when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
329 reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
332 Do strict boot via @option{strict=on} as far as firmware/BIOS
333 supports it. This only effects when boot priority is changed by
334 bootindex options. The default is non-strict boot.
337 # try to boot from network first, then from hard disk
338 qemu-system-i386 -boot order=nc
339 # boot from CD-ROM first, switch back to default order after reboot
340 qemu-system-i386 -boot once=d
341 # boot with a splash picture for 5 seconds.
342 qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
345 Note: The legacy format '-boot @var{drives}' is still supported but its
346 use is discouraged as it may be removed from future versions.
349 DEF("m
", HAS_ARG, QEMU_OPTION_m,
350 "-m
[size
=]megs
[,slots
=n
,maxmem
=size
]\n"
351 " configure guest RAM
\n"
352 " size
: initial amount of guest memory
\n"
353 " slots
: number of hotplug
slots (default: none
)\n"
354 " maxmem
: maximum amount of guest
memory (default: none
)\n"
355 "NOTE
: Some architectures might enforce a specific granularity
\n",
358 @item -m [size=]@var{megs}[,slots=n,maxmem=size]
360 Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
361 Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
362 megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
363 could be used to set amount of hotpluggable memory slots and maximum amount of
364 memory. Note that @var{maxmem} must be aligned to the page size.
366 For example, the following command-line sets the guest startup RAM size to
367 1GB, creates 3 slots to hotplug additional memory and sets the maximum
368 memory the guest can reach to 4GB:
371 qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
374 If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
375 be enabled and the guest startup RAM will never increase.
378 DEF("mem
-path
", HAS_ARG, QEMU_OPTION_mempath,
379 "-mem
-path FILE provide backing storage
for guest RAM
\n", QEMU_ARCH_ALL)
381 @item -mem-path @var{path}
383 Allocate guest RAM from a temporarily created file in @var{path}.
386 DEF("mem
-prealloc
", 0, QEMU_OPTION_mem_prealloc,
387 "-mem
-prealloc preallocate guest
memory (use with
-mem
-path
)\n",
391 @findex -mem-prealloc
392 Preallocate memory when using -mem-path.
395 DEF("k
", HAS_ARG, QEMU_OPTION_k,
396 "-k language use keyboard
layout (for example
'fr' for French
)\n",
399 @item -k @var{language}
401 Use keyboard layout @var{language} (for example @code{fr} for
402 French). This option is only needed where it is not easy to get raw PC
403 keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
404 display). You don't normally need to use it on PC/Linux or PC/Windows
407 The available layouts are:
409 ar de-ch es fo fr-ca hu ja mk no pt-br sv
410 da en-gb et fr fr-ch is lt nl pl ru th
411 de en-us fi fr-be hr it lv nl-be pt sl tr
414 The default is @code{en-us}.
418 DEF("audio
-help
", 0, QEMU_OPTION_audio_help,
419 "-audio
-help print list of audio drivers and their options
\n",
424 Will show the audio subsystem help: list of drivers, tunable
428 DEF("soundhw
", HAS_ARG, QEMU_OPTION_soundhw,
429 "-soundhw c1
,... enable audio support
\n"
430 " and only specified sound
cards (comma separated list
)\n"
431 " use
'-soundhw help' to get the list of supported cards
\n"
432 " use
'-soundhw all' to enable all of them
\n", QEMU_ARCH_ALL)
434 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
436 Enable audio and selected sound hardware. Use 'help' to print all
437 available sound hardware.
440 qemu-system-i386 -soundhw sb16,adlib disk.img
441 qemu-system-i386 -soundhw es1370 disk.img
442 qemu-system-i386 -soundhw ac97 disk.img
443 qemu-system-i386 -soundhw hda disk.img
444 qemu-system-i386 -soundhw all disk.img
445 qemu-system-i386 -soundhw help
448 Note that Linux's i810_audio OSS kernel (for AC97) module might
449 require manually specifying clocking.
452 modprobe i810_audio clocking=48000
456 DEF("balloon
", HAS_ARG, QEMU_OPTION_balloon,
457 "-balloon none disable balloon device
\n"
458 "-balloon virtio
[,addr
=str
]\n"
459 " enable virtio balloon
device (default)\n", QEMU_ARCH_ALL)
463 Disable balloon device.
464 @item -balloon virtio[,addr=@var{addr}]
465 Enable virtio balloon device (default), optionally with PCI address
469 DEF("device
", HAS_ARG, QEMU_OPTION_device,
470 "-device driver
[,prop
[=value
][,...]]\n"
471 " add
device (based on driver
)\n"
472 " prop
=value
,... sets driver properties
\n"
473 " use
'-device help' to print all possible drivers
\n"
474 " use
'-device driver,help' to print all possible properties
\n",
477 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
479 Add device @var{driver}. @var{prop}=@var{value} sets driver
480 properties. Valid properties depend on the driver. To get help on
481 possible drivers and properties, use @code{-device help} and
482 @code{-device @var{driver},help}.
485 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
487 Add an IPMI BMC. This is a simulation of a hardware management
488 interface processor that normally sits on a system. It provides
489 a watchdog and the ability to reset and power control the system.
490 You need to connect this to an IPMI interface to make it useful
492 The IPMI slave address to use for the BMC. The default is 0x20.
493 This address is the BMC's address on the I2C network of management
494 controllers. If you don't know what this means, it is safe to ignore
499 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
500 @item slave_addr=@var{val}
501 Define slave address to use for the BMC. The default is 0x20.
502 @item sdrfile=@var{file}
503 file containing raw Sensor Data Records (SDR) data. The default is none.
504 @item fruareasize=@var{val}
505 size of a Field Replaceable Unit (FRU) area. The default is 1024.
506 @item frudatafile=@var{file}
507 file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
510 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
512 Add a connection to an external IPMI BMC simulator. Instead of
513 locally emulating the BMC like the above item, instead connect
514 to an external entity that provides the IPMI services.
516 A connection is made to an external BMC simulator. If you do this, it
517 is strongly recommended that you use the "reconnect
=" chardev option
518 to reconnect to the simulator if the connection is lost. Note that if
519 this is not used carefully, it can be a security issue, as the
520 interface has the ability to send resets, NMIs, and power off the VM.
521 It's best if QEMU makes a connection to an external simulator running
522 on a secure port on localhost, so neither the simulator nor QEMU is
523 exposed to any outside network.
525 See the "lanserv
/README
.vm
" file in the OpenIPMI library for more
526 details on the external interface.
528 @item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
530 Add a KCS IPMI interafce on the ISA bus. This also adds a
531 corresponding ACPI and SMBIOS entries, if appropriate.
535 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
536 @item ioport=@var{val}
537 Define the I/O address of the interface. The default is 0xca0 for KCS.
539 Define the interrupt to use. The default is 5. To disable interrupts,
543 @item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
545 Like the KCS interface, but defines a BT interface. The default port is
546 0xe4 and the default interrupt is 5.
550 DEF("name
", HAS_ARG, QEMU_OPTION_name,
551 "-name string1
[,process
=string2
][,debug
-threads
=on|off
]\n"
552 " set the name of the guest
\n"
553 " string1 sets the window title and string2 the process
name (on Linux
)\n"
554 " When debug
-threads is enabled
, individual threads are given a separate
name (on Linux
)\n"
555 " NOTE
: The thread names are
for debugging and not a stable API
.\n",
558 @item -name @var{name}
560 Sets the @var{name} of the guest.
561 This name will be displayed in the SDL window caption.
562 The @var{name} will also be used for the VNC server.
563 Also optionally set the top visible process name in Linux.
564 Naming of individual threads can also be enabled on Linux to aid debugging.
567 DEF("uuid
", HAS_ARG, QEMU_OPTION_uuid,
568 "-uuid
%08x
-%04x
-%04x
-%04x
-%012x
\n"
569 " specify machine UUID
\n", QEMU_ARCH_ALL)
571 @item -uuid @var{uuid}
581 DEFHEADING(Block device options)
586 DEF("fda
", HAS_ARG, QEMU_OPTION_fda,
587 "-fda
/-fdb file use
'file' as floppy disk
0/1 image
\n", QEMU_ARCH_ALL)
588 DEF("fdb
", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
590 @item -fda @var{file}
591 @itemx -fdb @var{file}
594 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
597 DEF("hda
", HAS_ARG, QEMU_OPTION_hda,
598 "-hda
/-hdb file use
'file' as IDE hard disk
0/1 image
\n", QEMU_ARCH_ALL)
599 DEF("hdb
", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
600 DEF("hdc
", HAS_ARG, QEMU_OPTION_hdc,
601 "-hdc
/-hdd file use
'file' as IDE hard disk
2/3 image
\n", QEMU_ARCH_ALL)
602 DEF("hdd
", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
604 @item -hda @var{file}
605 @itemx -hdb @var{file}
606 @itemx -hdc @var{file}
607 @itemx -hdd @var{file}
612 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
615 DEF("cdrom
", HAS_ARG, QEMU_OPTION_cdrom,
616 "-cdrom file use
'file' as IDE cdrom
image (cdrom is ide1 master
)\n",
619 @item -cdrom @var{file}
621 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
622 @option{-cdrom} at the same time). You can use the host CD-ROM by
623 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
626 DEF("blockdev
", HAS_ARG, QEMU_OPTION_blockdev,
627 "-blockdev
[driver
=]driver
[,node
-name
=N
][,discard
=ignore|unmap
]\n"
628 " [,cache
.direct
=on|off
][,cache
.no
-flush
=on|off
]\n"
629 " [,read
-only
=on|off
][,detect
-zeroes
=on|off|unmap
]\n"
630 " [,driver specific parameters
...]\n"
631 " configure a block backend
\n", QEMU_ARCH_ALL)
633 @item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
636 Define a new block driver node. Some of the options apply to all block drivers,
637 other options are only accepted for a specific block driver. See below for a
638 list of generic options and options for the most common block drivers.
640 Options that expect a reference to another node (e.g. @code{file}) can be
641 given in two ways. Either you specify the node name of an already existing node
642 (file=@var{node-name}), or you define a new node inline, adding options
643 for the referenced node after a dot (file.filename=@var{path},file.aio=native).
645 A block driver node created with @option{-blockdev} can be used for a guest
646 device by specifying its node name for the @code{drive} property in a
647 @option{-device} argument that defines a block device.
650 @item Valid options for any block driver node:
654 Specifies the block driver to use for the given node.
656 This defines the name of the block driver node by which it will be referenced
657 later. The name must be unique, i.e. it must not match the name of a different
658 block driver node, or (if you use @option{-drive} as well) the ID of a drive.
660 If no node name is specified, it is automatically generated. The generated node
661 name is not intended to be predictable and changes between QEMU invocations.
662 For the top level, an explicit node name must be specified.
664 Open the node read-only. Guest write attempts will fail.
666 The host page cache can be avoided with @option{cache.direct=on}. This will
667 attempt to do disk IO directly to the guest's memory. QEMU may still perform an
668 internal copy of the data.
670 In case you don't care about data integrity over host failures, you can use
671 @option{cache.no-flush=on}. This option tells QEMU that it never needs to write
672 any data to the disk but can instead keep things in cache. If anything goes
673 wrong, like your host losing power, the disk storage getting disconnected
674 accidentally, etc. your image will most probably be rendered unusable.
675 @item discard=@var{discard}
676 @var{discard} is one of "ignore
" (or "off
") or "unmap
" (or "on
") and controls
677 whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
678 ignored or passed to the filesystem. Some machine types may not support
680 @item detect-zeroes=@var{detect-zeroes}
681 @var{detect-zeroes} is "off
", "on
" or "unmap
" and enables the automatic
682 conversion of plain zero writes by the OS to driver specific optimized
683 zero write commands. You may even choose "unmap
" if @var{discard} is set
684 to "unmap
" to allow a zero write to be converted to an @code{unmap} operation.
687 @item Driver-specific options for @code{file}
689 This is the protocol-level block driver for accessing regular files.
693 The path to the image file in the local filesystem
695 Specifies the AIO backend (threads/native, default: threads)
697 Specifies whether the image file is protected with Linux OFD / POSIX locks. The
698 default is to use the Linux Open File Descriptor API if available, otherwise no
699 lock is applied. (auto/on/off, default: auto)
703 -blockdev driver=file,node-name=disk,filename=disk.img
706 @item Driver-specific options for @code{raw}
708 This is the image format block driver for raw images. It is usually
709 stacked on top of a protocol level block driver such as @code{file}.
713 Reference to or definition of the data source block driver node
714 (e.g. a @code{file} driver node)
718 -blockdev driver=file,node-name=disk_file,filename=disk.img
719 -blockdev driver=raw,node-name=disk,file=disk_file
723 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
726 @item Driver-specific options for @code{qcow2}
728 This is the image format block driver for qcow2 images. It is usually
729 stacked on top of a protocol level block driver such as @code{file}.
733 Reference to or definition of the data source block driver node
734 (e.g. a @code{file} driver node)
737 Reference to or definition of the backing file block device (default is taken
738 from the image file). It is allowed to pass an empty string here in order to
739 disable the default backing file.
742 Whether to enable the lazy refcounts feature (on/off; default is taken from the
746 The maximum total size of the L2 table and refcount block caches in bytes
747 (default: 1048576 bytes or 8 clusters, whichever is larger)
750 The maximum size of the L2 table cache in bytes
751 (default: 4/5 of the total cache size)
753 @item refcount-cache-size
754 The maximum size of the refcount block cache in bytes
755 (default: 1/5 of the total cache size)
757 @item cache-clean-interval
758 Clean unused entries in the L2 and refcount caches. The interval is in seconds.
759 The default value is 0 and it disables this feature.
761 @item pass-discard-request
762 Whether discard requests to the qcow2 device should be forwarded to the data
763 source (on/off; default: on if discard=unmap is specified, off otherwise)
765 @item pass-discard-snapshot
766 Whether discard requests for the data source should be issued when a snapshot
767 operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
770 @item pass-discard-other
771 Whether discard requests for the data source should be issued on other
772 occasions where a cluster gets freed (on/off; default: off)
775 Which overlap checks to perform for writes to the image
776 (none/constant/cached/all; default: cached). For details or finer
777 granularity control refer to the QAPI documentation of @code{blockdev-add}.
782 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
783 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
787 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
790 @item Driver-specific options for other drivers
791 Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
797 DEF("drive
", HAS_ARG, QEMU_OPTION_drive,
798 "-drive
[file
=file
][,if=type
][,bus
=n
][,unit
=m
][,media
=d
][,index
=i
]\n"
799 " [,cyls
=c
,heads
=h
,secs
=s
[,trans
=t
]][,snapshot
=on|off
]\n"
800 " [,cache
=writethrough|writeback|none|directsync|unsafe
][,format
=f
]\n"
801 " [,serial
=s
][,addr
=A
][,rerror
=ignore|stop|report
]\n"
802 " [,werror
=ignore|stop|report|enospc
][,id
=name
][,aio
=threads|native
]\n"
803 " [,readonly
=on|off
][,copy
-on
-read
=on|off
]\n"
804 " [,discard
=ignore|unmap
][,detect
-zeroes
=on|off|unmap
]\n"
805 " [[,bps
=b
]|
[[,bps_rd
=r
][,bps_wr
=w
]]]\n"
806 " [[,iops
=i
]|
[[,iops_rd
=r
][,iops_wr
=w
]]]\n"
807 " [[,bps_max
=bm
]|
[[,bps_rd_max
=rm
][,bps_wr_max
=wm
]]]\n"
808 " [[,iops_max
=im
]|
[[,iops_rd_max
=irm
][,iops_wr_max
=iwm
]]]\n"
809 " [[,iops_size
=is
]]\n"
811 " use
'file' as a drive image
\n", QEMU_ARCH_ALL)
813 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
816 Define a new drive. This includes creating a block driver node (the backend) as
817 well as a guest device, and is mostly a shortcut for defining the corresponding
818 @option{-blockdev} and @option{-device} options.
820 @option{-drive} accepts all options that are accepted by @option{-blockdev}. In
821 addition, it knows the following options:
824 @item file=@var{file}
825 This option defines which disk image (@pxref{disk_images}) to use with
826 this drive. If the filename contains comma, you must double it
827 (for instance, "file
=my
,,file
" to use file "my
,file
").
829 Special files such as iSCSI devices can be specified using protocol
830 specific URLs. See the section for "Device URL Syntax
" for more information.
831 @item if=@var{interface}
832 This option defines on which type on interface the drive is connected.
833 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
834 @item bus=@var{bus},unit=@var{unit}
835 These options define where is connected the drive by defining the bus number and
837 @item index=@var{index}
838 This option defines where is connected the drive by using an index in the list
839 of available connectors of a given interface type.
840 @item media=@var{media}
841 This option defines the type of the media: disk or cdrom.
842 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
843 These options have the same definition as they have in @option{-hdachs}.
844 These parameters are deprecated, use the corresponding parameters
845 of @code{-device} instead.
846 @item snapshot=@var{snapshot}
847 @var{snapshot} is "on
" or "off
" and controls snapshot mode for the given drive
848 (see @option{-snapshot}).
849 @item cache=@var{cache}
850 @var{cache} is "none
", "writeback
", "unsafe
", "directsync
" or "writethrough
"
851 and controls how the host cache is used to access block data. This is a
852 shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
853 options (as in @option{-blockdev}), and additionally @option{cache.writeback},
854 which provides a default for the @option{write-cache} option of block guest
855 devices (as in @option{-device}). The modes correspond to the following
858 @c Our texi2pod.pl script doesn't support @multitable, so fall back to using
859 @c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
860 @c and the HTML output.
862 @ │ cache.writeback cache.direct cache.no-flush
863 ─────────────┼─────────────────────────────────────────────────
864 writeback │ on off off
866 writethrough │ off off off
867 directsync │ off on off
871 The default mode is @option{cache=writeback}.
874 @var{aio} is "threads
", or "native
" and selects between pthread based disk I/O and native Linux AIO.
875 @item format=@var{format}
876 Specify which disk @var{format} will be used rather than detecting
877 the format. Can be used to specify format=raw to avoid interpreting
878 an untrusted format header.
879 @item serial=@var{serial}
880 This option specifies the serial number to assign to the device. This
881 parameter is deprecated, use the corresponding parameter of @code{-device}
883 @item addr=@var{addr}
884 Specify the controller's PCI address (if=virtio only). This parameter is
885 deprecated, use the corresponding parameter of @code{-device} instead.
886 @item werror=@var{action},rerror=@var{action}
887 Specify which @var{action} to take on write and read errors. Valid actions are:
888 "ignore
" (ignore the error and try to continue), "stop
" (pause QEMU),
889 "report
" (report the error to the guest), "enospc
" (pause QEMU only if the
890 host disk is full; report the error to the guest otherwise).
891 The default setting is @option{werror=enospc} and @option{rerror=report}.
892 @item copy-on-read=@var{copy-on-read}
893 @var{copy-on-read} is "on
" or "off
" and enables whether to copy read backing
894 file sectors into the image file.
895 @item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
896 Specify bandwidth throttling limits in bytes per second, either for all request
897 types or for reads or writes only. Small values can lead to timeouts or hangs
898 inside the guest. A safe minimum for disks is 2 MB/s.
899 @item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
900 Specify bursts in bytes per second, either for all request types or for reads
901 or writes only. Bursts allow the guest I/O to spike above the limit
903 @item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
904 Specify request rate limits in requests per second, either for all request
905 types or for reads or writes only.
906 @item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
907 Specify bursts in requests per second, either for all request types or for reads
908 or writes only. Bursts allow the guest I/O to spike above the limit
910 @item iops_size=@var{is}
911 Let every @var{is} bytes of a request count as a new request for iops
912 throttling purposes. Use this option to prevent guests from circumventing iops
913 limits by sending fewer but larger requests.
915 Join a throttling quota group with given name @var{g}. All drives that are
916 members of the same group are accounted for together. Use this option to
917 prevent guests from circumventing throttling limits by using many small disks
918 instead of a single larger disk.
921 By default, the @option{cache.writeback=on} mode is used. It will report data
922 writes as completed as soon as the data is present in the host page cache.
923 This is safe as long as your guest OS makes sure to correctly flush disk caches
924 where needed. If your guest OS does not handle volatile disk write caches
925 correctly and your host crashes or loses power, then the guest may experience
928 For such guests, you should consider using @option{cache.writeback=off}. This
929 means that the host page cache will be used to read and write data, but write
930 notification will be sent to the guest only after QEMU has made sure to flush
931 each write to the disk. Be aware that this has a major impact on performance.
933 When using the @option{-snapshot} option, unsafe caching is always used.
935 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
936 useful when the backing file is over a slow network. By default copy-on-read
939 Instead of @option{-cdrom} you can use:
941 qemu-system-i386 -drive file=file,index=2,media=cdrom
944 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
947 qemu-system-i386 -drive file=file,index=0,media=disk
948 qemu-system-i386 -drive file=file,index=1,media=disk
949 qemu-system-i386 -drive file=file,index=2,media=disk
950 qemu-system-i386 -drive file=file,index=3,media=disk
953 You can open an image using pre-opened file descriptors from an fd set:
956 -add-fd fd=3,set=2,opaque="rdwr
:/path
/to
/file
"
957 -add-fd fd=4,set=2,opaque="rdonly
:/path
/to
/file
"
958 -drive file=/dev/fdset/2,index=0,media=disk
961 You can connect a CDROM to the slave of ide0:
963 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
966 If you don't specify the "file
=" argument, you define an empty drive:
968 qemu-system-i386 -drive if=ide,index=1,media=cdrom
971 Instead of @option{-fda}, @option{-fdb}, you can use:
973 qemu-system-i386 -drive file=file,index=0,if=floppy
974 qemu-system-i386 -drive file=file,index=1,if=floppy
977 By default, @var{interface} is "ide
" and @var{index} is automatically
980 qemu-system-i386 -drive file=a -drive file=b"
984 qemu
-system
-i386
-hda a
-hdb b
988 DEF("mtdblock", HAS_ARG
, QEMU_OPTION_mtdblock
,
989 "-mtdblock file use 'file' as on-board Flash memory image\n",
992 @item
-mtdblock @
var{file
}
994 Use @
var{file
} as on
-board Flash memory image
.
997 DEF("sd", HAS_ARG
, QEMU_OPTION_sd
,
998 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL
)
1000 @item
-sd @
var{file
}
1002 Use @
var{file
} as SecureDigital card image
.
1005 DEF("pflash", HAS_ARG
, QEMU_OPTION_pflash
,
1006 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL
)
1008 @item
-pflash @
var{file
}
1010 Use @
var{file
} as a parallel flash image
.
1013 DEF("snapshot", 0, QEMU_OPTION_snapshot
,
1014 "-snapshot write to temporary files instead of disk image files\n",
1019 Write to temporary files instead of disk image files
. In
this case,
1020 the raw disk image you use is not written back
. You can however force
1021 the write back by pressing @key
{C
-a s
} (@pxref
{disk_images
}).
1024 DEF("hdachs", HAS_ARG
, QEMU_OPTION_hdachs
, \
1025 "-hdachs c,h,s[,t]\n" \
1026 " force hard disk 0 physical geometry and the optional BIOS\n" \
1027 " translation (t=none or lba) (usually QEMU can guess them)\n",
1030 @item
-hdachs @
var{c
},@
var{h
},@
var{s
},[,@
var{t
}]
1032 Force hard disk
0 physical
geometry (1 <= @
var{c
} <= 16383, 1 <=
1033 @
var{h
} <= 16, 1 <= @
var{s
} <= 63) and optionally force the BIOS
1034 translation
mode (@
var{t
}=none
, lba or auto
). Usually QEMU can guess
1035 all those parameters
. This option is deprecated
, please use
1036 @code
{-device ide
-hd
,cyls
=c
,heads
=h
,secs
=s
,...} instead
.
1039 DEF("fsdev", HAS_ARG
, QEMU_OPTION_fsdev
,
1040 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1041 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1042 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1043 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1044 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1045 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1046 " [[,throttling.iops-size=is]]\n",
1051 @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
}][,fmode
=@
var{fmode
}][,dmode
=@
var{dmode
}]
1053 Define a
new file system device
. Valid options are
:
1055 @item @
var{fsdriver
}
1056 This option specifies the fs driver backend to use
.
1057 Currently
"local", "handle" and
"proxy" file system drivers are supported
.
1059 Specifies identifier
for this device
1060 @item path
=@
var{path
}
1061 Specifies the export path
for the file system device
. Files under
1062 this path will be available to the
9p client on the guest
.
1063 @item security_model
=@
var{security_model
}
1064 Specifies the security model to be used
for this export path
.
1065 Supported security models are
"passthrough", "mapped-xattr", "mapped-file" and
"none".
1066 In
"passthrough" security model
, files are stored
using the same
1067 credentials as they are created on the guest
. This requires QEMU
1068 to run as root
. In
"mapped-xattr" security model
, some of the file
1069 attributes like uid
, gid
, mode bits and link target are stored as
1070 file attributes
. For
"mapped-file" these attributes are stored
in the
1071 hidden
.virtfs_metadata directory
. Directories exported by
this security model cannot
1072 interact with other unix tools
. "none" security model is same as
1073 passthrough except the sever won
't report failures if it fails to
1074 set file attributes like ownership. Security model is mandatory
1075 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
1076 security model as a parameter
.
1077 @item writeout
=@
var{writeout
}
1078 This is an optional argument
. The only supported value is
"immediate".
1079 This means that host page cache will be used to read and write data but
1080 write notification will be sent to the guest only when the data has been
1081 reported as written by the storage subsystem
.
1083 Enables exporting
9p share as a readonly mount
for guests
. By
default
1084 read
-write access is given
.
1085 @item socket
=@
var{socket
}
1086 Enables proxy filesystem driver to use passed socket file
for communicating
1087 with virtfs
-proxy
-helper
1088 @item sock_fd
=@
var{sock_fd
}
1089 Enables proxy filesystem driver to use passed socket descriptor
for
1090 communicating with virtfs
-proxy
-helper
. Usually a helper like libvirt
1091 will create socketpair and pass one of the fds as sock_fd
1092 @item fmode
=@
var{fmode
}
1093 Specifies the
default mode
for newly created files on the host
. Works only
1094 with security models
"mapped-xattr" and
"mapped-file".
1095 @item dmode
=@
var{dmode
}
1096 Specifies the
default mode
for newly created directories on the host
. Works
1097 only with security models
"mapped-xattr" and
"mapped-file".
1100 -fsdev option is used along with
-device driver
"virtio-9p-pci".
1101 @item
-device virtio
-9p
-pci
,fsdev
=@
var{id
},mount_tag
=@
var{mount_tag
}
1102 Options
for virtio
-9p
-pci driver are
:
1104 @item fsdev
=@
var{id
}
1105 Specifies the id value specified along with
-fsdev option
1106 @item mount_tag
=@
var{mount_tag
}
1107 Specifies the tag name to be used by the guest to mount
this export point
1112 DEF("virtfs", HAS_ARG
, QEMU_OPTION_virtfs
,
1113 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1114 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1119 @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
}][,fmode
=@
var{fmode
}][,dmode
=@
var{dmode
}]
1122 The general form of a Virtual File system pass
-through options are
:
1124 @item @
var{fsdriver
}
1125 This option specifies the fs driver backend to use
.
1126 Currently
"local", "handle" and
"proxy" file system drivers are supported
.
1128 Specifies identifier
for this device
1129 @item path
=@
var{path
}
1130 Specifies the export path
for the file system device
. Files under
1131 this path will be available to the
9p client on the guest
.
1132 @item security_model
=@
var{security_model
}
1133 Specifies the security model to be used
for this export path
.
1134 Supported security models are
"passthrough", "mapped-xattr", "mapped-file" and
"none".
1135 In
"passthrough" security model
, files are stored
using the same
1136 credentials as they are created on the guest
. This requires QEMU
1137 to run as root
. In
"mapped-xattr" security model
, some of the file
1138 attributes like uid
, gid
, mode bits and link target are stored as
1139 file attributes
. For
"mapped-file" these attributes are stored
in the
1140 hidden
.virtfs_metadata directory
. Directories exported by
this security model cannot
1141 interact with other unix tools
. "none" security model is same as
1142 passthrough except the sever won
't report failures if it fails to
1143 set file attributes like ownership. Security model is mandatory only
1144 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
1145 model as a parameter
.
1146 @item writeout
=@
var{writeout
}
1147 This is an optional argument
. The only supported value is
"immediate".
1148 This means that host page cache will be used to read and write data but
1149 write notification will be sent to the guest only when the data has been
1150 reported as written by the storage subsystem
.
1152 Enables exporting
9p share as a readonly mount
for guests
. By
default
1153 read
-write access is given
.
1154 @item socket
=@
var{socket
}
1155 Enables proxy filesystem driver to use passed socket file
for
1156 communicating with virtfs
-proxy
-helper
. Usually a helper like libvirt
1157 will create socketpair and pass one of the fds as sock_fd
1159 Enables proxy filesystem driver to use passed
'sock_fd' as the socket
1160 descriptor
for interfacing with virtfs
-proxy
-helper
1161 @item fmode
=@
var{fmode
}
1162 Specifies the
default mode
for newly created files on the host
. Works only
1163 with security models
"mapped-xattr" and
"mapped-file".
1164 @item dmode
=@
var{dmode
}
1165 Specifies the
default mode
for newly created directories on the host
. Works
1166 only with security models
"mapped-xattr" and
"mapped-file".
1170 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth
,
1171 "-virtfs_synth Create synthetic file system image\n",
1175 @findex
-virtfs_synth
1176 Create synthetic file system image
1184 DEFHEADING(USB options
)
1189 DEF("usb", 0, QEMU_OPTION_usb
,
1190 "-usb enable the USB driver (if it is not used by default yet)\n",
1195 Enable the USB
driver (if it is not used by
default yet
).
1198 DEF("usbdevice", HAS_ARG
, QEMU_OPTION_usbdevice
,
1199 "-usbdevice name add the host or guest USB device 'name'\n",
1203 @item
-usbdevice @
var{devname
}
1205 Add the USB device @
var{devname
}. Note that
this option is deprecated
,
1206 please use @code
{-device usb
-...} instead
. @xref
{usb_devices
}.
1211 Virtual Mouse
. This will
override the PS
/2 mouse emulation when activated
.
1214 Pointer device that uses absolute
coordinates (like a touchscreen
). This
1215 means QEMU is able to report the mouse position without having to grab the
1216 mouse
. Also overrides the PS
/2 mouse emulation when activated
.
1218 @item disk
:[format
=@
var{format
}]:@
var{file
}
1219 Mass storage device based on file
. The optional @
var{format
} argument
1220 will be used rather than detecting the format
. Can be used to specify
1221 @code
{format
=raw
} to avoid interpreting an untrusted format header
.
1223 @item host
:@
var{bus
}.@
var{addr
}
1224 Pass through the host device identified by @
var{bus
}.@
var{addr
} (Linux only
).
1226 @item host
:@
var{vendor_id
}:@
var{product_id
}
1227 Pass through the host device identified by @
var{vendor_id
}:@
var{product_id
}
1230 @item serial
:[vendorid
=@
var{vendor_id
}][,productid
=@
var{product_id
}]:@
var{dev
}
1231 Serial converter to host character device @
var{dev
}, see @code
{-serial
} for the
1235 Braille device
. This will use BrlAPI to display the braille output on a real
1238 @item net
:@
var{options
}
1239 Network adapter that supports CDC ethernet and RNDIS protocols
.
1249 DEFHEADING(Display options
)
1254 DEF("display", HAS_ARG
, QEMU_OPTION_display
,
1255 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1256 " [,window_close=on|off][,gl=on|off]\n"
1257 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1258 "-display vnc=<display>[,<optargs>]\n"
1261 " select display type\n"
1262 "The default display is equivalent to\n"
1263 #
if defined(CONFIG_GTK
)
1264 "\t\"-display gtk\"\n"
1265 #elif
defined(CONFIG_SDL
)
1266 "\t\"-display sdl\"\n"
1267 #elif
defined(CONFIG_COCOA
)
1268 "\t\"-display cocoa\"\n"
1269 #elif
defined(CONFIG_VNC
)
1270 "\t\"-vnc localhost:0,to=99,id=default\"\n"
1272 "\t\"-display none\"\n"
1276 @item
-display @
var{type
}
1278 Select type of display to use
. This option is a replacement
for the
1279 old style
-sdl
/-curses
/... options
. Valid values
for @
var{type
} are
1282 Display video output via
SDL (usually
in a separate graphics
1283 window
; see the SDL documentation
for other possibilities
).
1285 Display video output via curses
. For graphics device models which
1286 support a text mode
, QEMU can display
this output
using a
1287 curses
/ncurses
interface. Nothing is displayed when the graphics
1288 device is
in graphical mode or
if the graphics device does not support
1289 a text mode
. Generally only the VGA device models support text mode
.
1291 Do not display video output
. The guest will still see an emulated
1292 graphics card
, but its output will not be displayed to the QEMU
1293 user
. This option differs from the
-nographic option
in that it
1294 only affects what is done with video output
; -nographic also changes
1295 the destination of the serial and parallel port data
.
1297 Display video output
in a GTK window
. This
interface provides drop
-down
1298 menus and other UI elements to configure and control the VM during
1301 Start a VNC server on display
<arg
>
1305 DEF("nographic", 0, QEMU_OPTION_nographic
,
1306 "-nographic disable graphical output and redirect serial I/Os to console\n",
1311 Normally
, if QEMU is compiled with graphical window support
, it displays
1312 output such as guest graphics
, guest console
, and the QEMU monitor
in a
1313 window
. With
this option
, you can totally disable graphical output so
1314 that QEMU is a simple command line application
. The emulated serial port
1315 is redirected on the console and muxed with the
monitor (unless
1316 redirected elsewhere explicitly
). Therefore
, you can still use QEMU to
1317 debug a Linux kernel with a serial console
. Use @key
{C
-a h
} for help on
1318 switching between the console and monitor
.
1321 DEF("curses", 0, QEMU_OPTION_curses
,
1322 "-curses shorthand for -display curses\n",
1327 Normally
, if QEMU is compiled with graphical window support
, it displays
1328 output such as guest graphics
, guest console
, and the QEMU monitor
in a
1329 window
. With
this option
, QEMU can display the VGA output when
in text
1330 mode
using a curses
/ncurses
interface. Nothing is displayed
in graphical
1334 DEF("no-frame", 0, QEMU_OPTION_no_frame
,
1335 "-no-frame open SDL window without a frame and window decorations\n",
1340 Do not use decorations
for SDL windows and start them
using the whole
1341 available screen space
. This makes the
using QEMU
in a dedicated desktop
1342 workspace more convenient
.
1345 DEF("alt-grab", 0, QEMU_OPTION_alt_grab
,
1346 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1351 Use Ctrl
-Alt
-Shift to grab
mouse (instead of Ctrl
-Alt
). Note that
this also
1352 affects the special
keys (for fullscreen
, monitor
-mode switching
, etc
).
1355 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab
,
1356 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1361 Use Right
-Ctrl to grab
mouse (instead of Ctrl
-Alt
). Note that
this also
1362 affects the special
keys (for fullscreen
, monitor
-mode switching
, etc
).
1365 DEF("no-quit", 0, QEMU_OPTION_no_quit
,
1366 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL
)
1370 Disable SDL window close capability
.
1373 DEF("sdl", 0, QEMU_OPTION_sdl
,
1374 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL
)
1381 DEF("spice", HAS_ARG
, QEMU_OPTION_spice
,
1382 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1383 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1384 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1385 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1386 " [,tls-ciphers=<list>]\n"
1387 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1388 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1389 " [,sasl][,password=<secret>][,disable-ticketing]\n"
1390 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1391 " [,jpeg-wan-compression=[auto|never|always]]\n"
1392 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
1393 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1394 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1395 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1396 " [,gl=[on|off]][,rendernode=<file>]\n"
1398 " at least one of {port, tls-port} is mandatory\n",
1401 @item
-spice @
var{option
}[,@
var{option
}[,...]]
1403 Enable the spice remote desktop protocol
. Valid options are
1408 Set the TCP port spice is listening on
for plaintext channels
.
1411 Set the IP address spice is listening on
. Default is any address
.
1416 Force
using the specified IP version
.
1418 @item password
=<secret
>
1419 Set the password you need to authenticate
.
1422 Require that the client use SASL to authenticate with the spice
.
1423 The exact choice of authentication method used is controlled from the
1424 system
/ user
's SASL configuration file for the 'qemu
' service. This
1425 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1426 unprivileged user, an environment variable SASL_CONF_PATH can be used
1427 to make it search alternate locations for the service config.
1428 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1429 it is recommended that SASL always be combined with the 'tls
' and
1430 'x509
' settings to enable use of SSL and server certificates. This
1431 ensures a data encryption preventing compromise of authentication
1434 @item disable-ticketing
1435 Allow client connects without authentication.
1437 @item disable-copy-paste
1438 Disable copy paste between the client and the guest.
1440 @item disable-agent-file-xfer
1441 Disable spice-vdagent based file-xfer between the client and the guest.
1444 Set the TCP port spice is listening on for encrypted channels.
1446 @item x509-dir=<dir>
1447 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1449 @item x509-key-file=<file>
1450 @itemx x509-key-password=<file>
1451 @itemx x509-cert-file=<file>
1452 @itemx x509-cacert-file=<file>
1453 @itemx x509-dh-key-file=<file>
1454 The x509 file names can also be configured individually.
1456 @item tls-ciphers=<list>
1457 Specify which ciphers to use.
1459 @item tls-channel=[main|display|cursor|inputs|record|playback]
1460 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1461 Force specific channel to be used with or without TLS encryption. The
1462 options can be specified multiple times to configure multiple
1463 channels. The special name "default" can be used to set the default
1464 mode. For channels which are not explicitly forced into one mode the
1465 spice client is allowed to pick tls/plaintext as he pleases.
1467 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1468 Configure image compression (lossless).
1469 Default is auto_glz.
1471 @item jpeg-wan-compression=[auto|never|always]
1472 @itemx zlib-glz-wan-compression=[auto|never|always]
1473 Configure wan image compression (lossy for slow links).
1476 @item streaming-video=[off|all|filter]
1477 Configure video stream detection. Default is off.
1479 @item agent-mouse=[on|off]
1480 Enable/disable passing mouse events via vdagent. Default is on.
1482 @item playback-compression=[on|off]
1483 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1485 @item seamless-migration=[on|off]
1486 Enable/disable spice seamless migration. Default is off.
1489 Enable/disable OpenGL context. Default is off.
1491 @item rendernode=<file>
1492 DRM render node for OpenGL rendering. If not specified, it will pick
1493 the first available. (Since 2.9)
1498 DEF("portrait", 0, QEMU_OPTION_portrait,
1499 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1504 Rotate graphical output 90 deg left (only PXA LCD).
1507 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1508 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1511 @item -rotate @var{deg}
1513 Rotate graphical output some deg left (only PXA LCD).
1516 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1517 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1518 " select video card type\n", QEMU_ARCH_ALL)
1520 @item -vga @var{type}
1522 Select type of VGA card to emulate. Valid values for @var{type} are
1525 Cirrus Logic GD5446 Video card. All Windows versions starting from
1526 Windows 95 should recognize and use this graphic card. For optimal
1527 performances, use 16 bit color depth in the guest and the host OS.
1528 (This card was the default before QEMU 2.2)
1530 Standard VGA card with Bochs VBE extensions. If your guest OS
1531 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1532 to use high resolution modes (>= 1280x1024x16) then you should use
1533 this option. (This card is the default since QEMU 2.2)
1535 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1536 recent XFree86/XOrg server or Windows guest with a driver for this
1539 QXL paravirtual graphic card. It is VGA compatible (including VESA
1540 2.0 VBE support). Works best with qxl guest drivers installed though.
1541 Recommended choice when using the spice protocol.
1543 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1544 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1545 fixed resolution of 1024x768.
1547 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1548 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1549 resolutions aimed at people wishing to run older Solaris versions.
1557 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1558 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1561 @findex -full-screen
1562 Start in full screen.
1565 DEF("g", 1, QEMU_OPTION_g ,
1566 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1567 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1569 @item -g @var{width}x@var{height}[x@var{depth}]
1571 Set the initial graphical resolution and depth (PPC, SPARC only).
1574 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1575 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1577 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1579 Normally, if QEMU is compiled with graphical window support, it displays
1580 output such as guest graphics, guest console, and the QEMU monitor in a
1581 window. With this option, you can have QEMU listen on VNC display
1582 @var{display} and redirect the VGA display over the VNC session. It is
1583 very useful to enable the usb tablet device when using this option
1584 (option @option{-device usb-tablet}). When using the VNC display, you
1585 must use the @option{-k} parameter to set the keyboard layout if you are
1586 not using en-us. Valid syntax for the @var{display} is
1592 With this option, QEMU will try next available VNC @var{display}s, until the
1593 number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1594 available, e.g. port 5900+@var{display} is already used by another
1595 application. By default, to=0.
1597 @item @var{host}:@var{d}
1599 TCP connections will only be allowed from @var{host} on display @var{d}.
1600 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1601 be omitted in which case the server will accept connections from any host.
1603 @item unix:@var{path}
1605 Connections will be allowed over UNIX domain sockets where @var{path} is the
1606 location of a unix socket to listen for connections on.
1610 VNC is initialized but not started. The monitor @code{change} command
1611 can be used to later start the VNC server.
1615 Following the @var{display} value there may be one or more @var{option} flags
1616 separated by commas. Valid options are
1622 Connect to a listening VNC client via a ``reverse'' connection. The
1623 client is specified by the @var{display}. For reverse network
1624 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1625 is a TCP port number, not a display number.
1629 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1630 If a bare @var{websocket} option is given, the Websocket port is
1631 5700+@var{display}. An alternative port can be specified with the
1632 syntax @code{websocket}=@var{port}.
1634 If @var{host} is specified connections will only be allowed from this host.
1635 It is possible to control the websocket listen address independently, using
1636 the syntax @code{websocket}=@var{host}:@var{port}.
1638 If no TLS credentials are provided, the websocket connection runs in
1639 unencrypted mode. If TLS credentials are provided, the websocket connection
1640 requires encrypted client connections.
1644 Require that password based authentication is used for client connections.
1646 The password must be set separately using the @code{set_password} command in
1647 the @ref{pcsys_monitor}. The syntax to change your password is:
1648 @code{set_password <protocol> <password>} where <protocol> could be either
1651 If you would like to change <protocol> password expiration, you should use
1652 @code{expire_password <protocol> <expiration-time>} where expiration time could
1653 be one of the following options: now, never, +seconds or UNIX time of
1654 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1655 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1658 You can also use keywords "now" or "never" for the expiration time to
1659 allow <protocol> password to expire immediately or never expire.
1661 @item tls-creds=@var{ID}
1663 Provides the ID of a set of TLS credentials to use to secure the
1664 VNC server. They will apply to both the normal VNC server socket
1665 and the websocket socket (if enabled). Setting TLS credentials
1666 will cause the VNC server socket to enable the VeNCrypt auth
1667 mechanism. The credentials should have been previously created
1668 using the @option{-object tls-creds} argument.
1670 The @option{tls-creds} parameter obsoletes the @option{tls},
1671 @option{x509}, and @option{x509verify} options, and as such
1672 it is not permitted to set both new and old type options at
1677 Require that client use TLS when communicating with the VNC server. This
1678 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1679 attack. It is recommended that this option be combined with either the
1680 @option{x509} or @option{x509verify} options.
1682 This option is now deprecated in favor of using the @option{tls-creds}
1685 @item x509=@var{/path/to/certificate/dir}
1687 Valid if @option{tls} is specified. Require that x509 credentials are used
1688 for negotiating the TLS session. The server will send its x509 certificate
1689 to the client. It is recommended that a password be set on the VNC server
1690 to provide authentication of the client when this is used. The path following
1691 this option specifies where the x509 certificates are to be loaded from.
1692 See the @ref{vnc_security} section for details on generating certificates.
1694 This option is now deprecated in favour of using the @option{tls-creds}
1697 @item x509verify=@var{/path/to/certificate/dir}
1699 Valid if @option{tls} is specified. Require that x509 credentials are used
1700 for negotiating the TLS session. The server will send its x509 certificate
1701 to the client, and request that the client send its own x509 certificate.
1702 The server will validate the client's certificate against the CA certificate
,
1703 and reject clients when validation fails
. If the certificate authority is
1704 trusted
, this is a sufficient authentication mechanism
. You may still wish
1705 to set a password on the VNC server as a second authentication layer
. The
1706 path following
this option specifies where the x509 certificates are to
1707 be loaded from
. See the @ref
{vnc_security
} section
for details on generating
1710 This option is now deprecated
in favour of
using the @option
{tls
-creds
}
1715 Require that the client use SASL to authenticate with the VNC server
.
1716 The exact choice of authentication method used is controlled from the
1717 system
/ user
's SASL configuration file for the 'qemu
' service. This
1718 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1719 unprivileged user, an environment variable SASL_CONF_PATH can be used
1720 to make it search alternate locations for the service config.
1721 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1722 it is recommended that SASL always be combined with the 'tls
' and
1723 'x509
' settings to enable use of SSL and server certificates. This
1724 ensures a data encryption preventing compromise of authentication
1725 credentials. See the @ref{vnc_security} section for details on using
1726 SASL authentication.
1730 Turn on access control lists for checking of the x509 client certificate
1731 and SASL party. For x509 certs, the ACL check is made against the
1732 certificate's distinguished name
. This is something that looks like
1733 @code
{C
=GB
,O
=ACME
,L
=Boston
,CN
=bob
}. For SASL party
, the ACL check is
1734 made against the username
, which depending on the SASL plugin
, may
1735 include a realm component
, eg @code
{bob
} or @code
{bob@@EXAMPLE
.COM
}.
1736 When the @option
{acl
} flag is set
, the initial access list will be
1737 empty
, with a @code
{deny
} policy
. Thus no one will be allowed to
1738 use the VNC server until the ACLs have been loaded
. This can be
1739 achieved
using the @code
{acl
} monitor command
.
1743 Enable lossy compression
methods (gradient
, JPEG
, ...). If
this
1744 option is set
, VNC client may receive lossy framebuffer updates
1745 depending on its encoding settings
. Enabling
this option can save
1746 a lot of bandwidth at the expense of quality
.
1750 Disable adaptive encodings
. Adaptive encodings are enabled by
default.
1751 An adaptive encoding will
try to detect frequently updated screen regions
,
1752 and send updates
in these regions
using a lossy
encoding (like JPEG
).
1753 This can be really helpful to save bandwidth when playing videos
. Disabling
1754 adaptive encodings restores the original
static behavior of encodings
1757 @item share
=[allow
-exclusive|force
-shared|ignore
]
1759 Set display sharing policy
. 'allow-exclusive' allows clients to ask
1760 for exclusive access
. As suggested by the rfb spec
this is
1761 implemented by dropping other connections
. Connecting multiple
1762 clients
in parallel requires all clients asking
for a shared session
1763 (vncviewer
: -shared
switch). This is the
default. 'force-shared'
1764 disables exclusive client access
. Useful
for shared desktop sessions
,
1765 where you don
't want someone forgetting specify -shared disconnect
1766 everybody else. 'ignore
' completely ignores the shared flag and
1767 allows everybody connect unconditionally. Doesn't conform to the rfb
1768 spec but is traditional QEMU behavior
.
1772 Set keyboard delay
, for key down and key up events
, in milliseconds
.
1773 Default is
10. Keyboards are low
-bandwidth devices
, so
this slowdown
1774 can help the device and guest to keep up and not lose events
in case
1775 events are arriving
in bulk
. Possible causes
for the latter are flaky
1776 network connections
, or scripts
for automated testing
.
1784 ARCHHEADING(, QEMU_ARCH_I386
)
1786 ARCHHEADING(i386 target only
, QEMU_ARCH_I386
)
1791 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack
,
1792 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1797 Use it when installing Windows
2000 to avoid a disk full bug
. After
1798 Windows
2000 is installed
, you no longer need
this option (this option
1799 slows down the IDE transfers
).
1802 HXCOMM Deprecated by
-rtc
1803 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack
, "", QEMU_ARCH_I386
)
1805 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk
,
1806 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1809 @item
-no
-fd
-bootchk
1810 @findex
-no
-fd
-bootchk
1811 Disable boot signature checking
for floppy disks
in BIOS
. May
1812 be needed to boot from old floppy disks
.
1815 DEF("no-acpi", 0, QEMU_OPTION_no_acpi
,
1816 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM
)
1820 Disable
ACPI (Advanced Configuration and Power Interface
) support
. Use
1821 it
if your guest OS complains about ACPI
problems (PC target machine
1825 DEF("no-hpet", 0, QEMU_OPTION_no_hpet
,
1826 "-no-hpet disable HPET\n", QEMU_ARCH_I386
)
1830 Disable HPET support
.
1833 DEF("acpitable", HAS_ARG
, QEMU_OPTION_acpitable
,
1834 "-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"
1835 " ACPI table description\n", QEMU_ARCH_I386
)
1837 @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
}]...]
1839 Add ACPI table with specified header fields and context from specified files
.
1840 For file
=, take whole ACPI table from the specified files
, including all
1841 ACPI
headers (possible overridden by other options
).
1842 For data
=, only data
1843 portion of the table is used
, all header information is specified
in the
1845 If a SLIC table is supplied to QEMU
, then the SLIC
's oem_id and oem_table_id
1846 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1847 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1851 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1852 "-smbios file=binary\n"
1853 " load SMBIOS entry from binary file\n"
1854 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1856 " specify SMBIOS type 0 fields\n"
1857 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1858 " [,uuid=uuid][,sku=str][,family=str]\n"
1859 " specify SMBIOS type 1 fields\n"
1860 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1861 " [,asset=str][,location=str]\n"
1862 " specify SMBIOS type 2 fields\n"
1863 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1865 " specify SMBIOS type 3 fields\n"
1866 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1867 " [,asset=str][,part=str]\n"
1868 " specify SMBIOS type 4 fields\n"
1869 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1870 " [,asset=str][,part=str][,speed=%d]\n"
1871 " specify SMBIOS type 17 fields\n",
1872 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1874 @item -smbios file=@var{binary}
1876 Load SMBIOS entry from binary file.
1878 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1879 Specify SMBIOS type 0 fields
1881 @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}]
1882 Specify SMBIOS type 1 fields
1884 @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}]
1885 Specify SMBIOS type 2 fields
1887 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1888 Specify SMBIOS type 3 fields
1890 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1891 Specify SMBIOS type 4 fields
1893 @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}]
1894 Specify SMBIOS type 17 fields
1902 DEFHEADING(Network options)
1907 HXCOMM Legacy slirp options (now moved to -net user):
1909 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1910 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1911 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1913 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1917 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1919 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1920 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1921 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1922 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
1923 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1925 "[,smb=dir[,smbserver=addr]]\n"
1927 " configure a user mode network backend with ID 'str
',\n"
1928 " its DHCP server and optional services\n"
1931 "-netdev tap,id=str,ifname=name\n"
1932 " configure a host TAP network backend with ID 'str
'\n"
1934 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1935 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1936 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1938 " configure a host TAP network backend with ID 'str
'\n"
1939 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1940 " use network scripts 'file
' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1941 " to configure it and 'dfile
' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1942 " to deconfigure it\n"
1943 " use '[down
]script
=no
' to disable script execution\n"
1944 " use network helper 'helper
' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1946 " use 'fd
=h
' to connect to an already opened TAP interface\n"
1947 " use 'fds
=x
:y
:...:z
' to connect to already opened multiqueue capable TAP interfaces\n"
1948 " use 'sndbuf
=nbytes
' to limit the size of the send buffer (the\n"
1949 " default is disabled 'sndbuf
=0' to enable flow control set 'sndbuf
=1048576')\n"
1950 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1951 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1952 " use vhost=on to enable experimental in kernel accelerator\n"
1953 " (only has effect for virtio guests which use MSIX)\n"
1954 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1955 " use 'vhostfd
=h
' to connect to an already opened vhost net device\n"
1956 " use 'vhostfds
=x
:y
:...:z to connect to multiple already opened vhost net devices
\n"
1957 " use
'queues=n' to specify the number of queues to be created
for multiqueue TAP
\n"
1958 " use
'poll-us=n' to speciy the maximum number of microseconds that could be
\n"
1959 " spent on busy polling
for vhost net
\n"
1960 "-netdev bridge
,id
=str
[,br
=bridge
][,helper
=helper
]\n"
1961 " configure a host TAP network backend with ID
'str' that is
\n"
1962 " connected to a
bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1963 " using the program
'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1966 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1967 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1968 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1969 " [,rxcookie=rxcookie][,offset=offset]\n"
1970 " configure a network backend with ID 'str
' connected to\n"
1971 " an Ethernet over L2TPv3 pseudowire.\n"
1972 " Linux kernel 3.3+ as well as most routers can talk\n"
1973 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1974 " VM to a router and even VM to Host. It is a nearly-universal\n"
1975 " standard (RFC3391). Note - this implementation uses static\n"
1976 " pre-configured tunnels (same as the Linux kernel).\n"
1977 " use 'src
=' to specify source address\n"
1978 " use 'dst
=' to specify destination address\n"
1979 " use 'udp
=on
' to specify udp encapsulation\n"
1980 " use 'srcport
=' to specify source udp port\n"
1981 " use 'dstport
=' to specify destination udp port\n"
1982 " use 'ipv6
=on
' to force v6\n"
1983 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1984 " well as a weak security measure\n"
1985 " use 'rxcookie
=0x012345678' to specify a rxcookie\n"
1986 " use 'txcookie
=0x012345678' to specify a txcookie\n"
1987 " use 'cookie64
=on
' to set cookie size to 64 bit, otherwise 32\n"
1988 " use 'counter
=off
' to force a 'cut
-down
' L2TPv3 with no counter\n"
1989 " use 'pincounter
=on
' to work around broken counter handling in peer\n"
1990 " use 'offset
=X
' to add an extra offset between header and data\n"
1992 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1993 " configure a network backend to connect to another network\n"
1994 " using a socket connection\n"
1995 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1996 " configure a network backend to connect to a multicast maddr and port\n"
1997 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1998 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1999 " configure a network backend to connect to another network\n"
2000 " using an UDP tunnel\n"
2002 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
2003 " configure a network backend to connect to port 'n
' of a vde switch\n"
2004 " running on host and listening for incoming connections on 'socketpath
'.\n"
2005 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
2006 " ownership and permissions for communication port.\n"
2008 #ifdef CONFIG_NETMAP
2009 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
2010 " attach to the existing netmap-enabled network interface 'name
', or to a\n"
2011 " VALE port (created on the fly) called 'name
' ('nmname
' is name of the \n"
2012 " netmap device, defaults to '/dev
/netmap
')\n"
2014 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2015 " configure a vhost-user network, backed by a chardev 'dev
'\n"
2016 "-netdev hubport,id=str,hubid=n\n"
2017 " configure a hub port on QEMU VLAN 'n
'\n", QEMU_ARCH_ALL)
2018 DEF("net", HAS_ARG, QEMU_OPTION_net,
2019 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
2020 " old way to create a new NIC and connect it to VLAN 'n
'\n"
2021 " (use the '-device devtype
,netdev
=str
' option if possible instead)\n"
2022 "-net dump[,vlan=n][,file=f][,len=n]\n"
2023 " dump traffic on vlan 'n
' to file 'f
' (max n bytes per packet)\n"
2024 "-net none use it alone to have zero network devices. If no -net option\n"
2025 " is provided, the default is '-net nic
-net user
'\n"
2035 #ifdef CONFIG_NETMAP
2038 "socket][,vlan=n][,option][,option][,...]\n"
2039 " old way to initialize a host network interface\n"
2040 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2042 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2044 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
2045 = 0 is the default). The NIC is an e1000 by default on the PC
2046 target. Optionally, the MAC address can be changed to @var{mac}, the
2047 device address set to @var{addr} (PCI cards only),
2048 and a @var{name} can be assigned for use in monitor commands.
2049 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2050 that the card should have; this option currently only affects virtio cards; set
2051 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2052 NIC is created. QEMU can emulate several different models of network card.
2053 Valid values for @var{type} are
2054 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
2055 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
2056 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
2057 Not all devices are supported on all targets. Use @code{-net nic,model=help}
2058 for a list of available devices for your target.
2060 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2062 @item -net user[,@var{option}][,@var{option}][,...]
2063 Use the user mode network stack which requires no administrator
2064 privilege to run. Valid options are:
2068 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
2071 @itemx name=@var{name}
2072 Assign symbolic name for use in monitor commands.
2074 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
2075 be enabled. If neither is specified both protocols are enabled.
2077 @item net=@var{addr}[/@var{mask}]
2078 Set IP network address the guest will see. Optionally specify the netmask,
2079 either in the form a.b.c.d or as number of valid top-most bits. Default is
2082 @item host=@var{addr}
2083 Specify the guest-visible address of the host. Default is the 2nd IP in the
2084 guest network, i.e. x.x.x.2.
2086 @item ipv6-net=@var{addr}[/@var{int}]
2087 Set IPv6 network address the guest will see (default is fec0::/64). The
2088 network prefix is given in the usual hexadecimal IPv6 address
2089 notation. The prefix size is optional, and is given as the number of
2090 valid top-most bits (default is 64).
2092 @item ipv6-host=@var{addr}
2093 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2094 the guest network, i.e. xxxx::2.
2096 @item restrict=on|off
2097 If this option is enabled, the guest will be isolated, i.e. it will not be
2098 able to contact the host and no guest IP packets will be routed over the host
2099 to the outside. This option does not affect any explicitly set forwarding rules.
2101 @item hostname=@var{name}
2102 Specifies the client hostname reported by the built-in DHCP server.
2104 @item dhcpstart=@var{addr}
2105 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2106 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2108 @item dns=@var{addr}
2109 Specify the guest-visible address of the virtual nameserver. The address must
2110 be different from the host address. Default is the 3rd IP in the guest network,
2113 @item ipv6-dns=@var{addr}
2114 Specify the guest-visible address of the IPv6 virtual nameserver. The address
2115 must be different from the host address. Default is the 3rd IP in the guest
2116 network, i.e. xxxx::3.
2118 @item dnssearch=@var{domain}
2119 Provides an entry for the domain-search list sent by the built-in
2120 DHCP server. More than one domain suffix can be transmitted by specifying
2121 this option multiple times. If supported, this will cause the guest to
2122 automatically try to append the given domain suffix(es) in case a domain name
2123 can not be resolved.
2127 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
2130 @item tftp=@var{dir}
2131 When using the user mode network stack, activate a built-in TFTP
2132 server. The files in @var{dir} will be exposed as the root of a TFTP server.
2133 The TFTP client on the guest must be configured in binary mode (use the command
2134 @code{bin} of the Unix TFTP client).
2136 @item bootfile=@var{file}
2137 When using the user mode network stack, broadcast @var{file} as the BOOTP
2138 filename. In conjunction with @option{tftp}, this can be used to network boot
2139 a guest from a local directory.
2141 Example (using pxelinux):
2143 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2146 @item smb=@var{dir}[,smbserver=@var{addr}]
2147 When using the user mode network stack, activate a built-in SMB
2148 server so that Windows OSes can access to the host files in @file{@var{dir}}
2149 transparently. The IP address of the SMB server can be set to @var{addr}. By
2150 default the 4th IP in the guest network is used, i.e. x.x.x.4.
2152 In the guest Windows OS, the line:
2156 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2157 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2159 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2161 Note that a SAMBA server must be installed on the host OS.
2162 QEMU was tested successfully with smbd versions from Red Hat 9,
2163 Fedora Core 3 and OpenSUSE 11.x.
2165 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2166 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2167 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2168 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2169 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2170 be bound to a specific host interface. If no connection type is set, TCP is
2171 used. This option can be given multiple times.
2173 For example, to redirect host X11 connection from screen 1 to guest
2174 screen 0, use the following:
2178 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
2179 # this host xterm should open in the guest X11 server
2183 To redirect telnet connections from host port 5555 to telnet port on
2184 the guest, use the following:
2188 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
2189 telnet localhost 5555
2192 Then when you use on the host @code{telnet localhost 5555}, you
2193 connect to the guest telnet server.
2195 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2196 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2197 Forward guest TCP connections to the IP address @var{server} on port @var{port}
2198 to the character device @var{dev} or to a program executed by @var{cmd:command}
2199 which gets spawned for each connection. This option can be given multiple times.
2201 You can either use a chardev directly and have that one used throughout QEMU's
2202 lifetime
, like
in the following example
:
2205 # open
10.10.1.1:4321 on bootup
, connect
10.0.2.100:1234 to it whenever
2206 # the guest accesses it
2207 qemu
-net user
,guestfwd
=tcp
:10.0.2.100:1234-tcp
:10.10.1.1:4321 [...]
2210 Or you can execute a command on every TCP connection established by the guest
,
2211 so that QEMU behaves similar to an inetd process
for that virtual server
:
2214 # call
"netcat 10.10.1.1 4321" on every TCP connection to
10.0.2.100:1234
2215 # and connect the TCP stream to its stdin
/stdout
2216 qemu
-net
'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2221 Note
: Legacy stand
-alone options
-tftp
, -bootp
, -smb and
-redir are still
2222 processed and applied to
-net user
. Mixing them with the
new configuration
2223 syntax gives undefined results
. Their use
for new applications is discouraged
2224 as they will be removed from future versions
.
2226 @item
-netdev tap
,id
=@
var{id
}[,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
2227 @itemx
-net tap
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
2228 Connect the host TAP network
interface @
var{name
} to VLAN @
var{n
}.
2230 Use the network script @
var{file
} to configure it and the network script
2231 @
var{dfile
} to deconfigure it
. If @
var{name
} is not provided
, the OS
2232 automatically provides one
. The
default network configure script is
2233 @file
{/etc
/qemu
-ifup
} and the
default network deconfigure script is
2234 @file
{/etc
/qemu
-ifdown
}. Use @option
{script
=no
} or @option
{downscript
=no
}
2235 to disable script execution
.
2237 If running QEMU as an unprivileged user
, use the network helper
2238 @
var{helper
} to configure the TAP
interface and attach it to the bridge
.
2239 The
default network helper executable is @file
{/path
/to
/qemu
-bridge
-helper
}
2240 and the
default bridge device is @file
{br0
}.
2242 @option
{fd
}=@
var{h
} can be used to specify the handle of an already
2243 opened host TAP
interface.
2248 #launch a QEMU instance with the
default network script
2249 qemu
-system
-i386 linux
.img
-net nic
-net tap
2253 #launch a QEMU instance with two NICs
, each one connected
2255 qemu
-system
-i386 linux
.img \
2256 -net nic
,vlan
=0 -net tap
,vlan
=0,ifname
=tap0 \
2257 -net nic
,vlan
=1 -net tap
,vlan
=1,ifname
=tap1
2261 #launch a QEMU instance with the
default network helper to
2262 #connect a TAP device to bridge br0
2263 qemu
-system
-i386 linux
.img \
2264 -net nic
-net tap
,"helper=/path/to/qemu-bridge-helper"
2267 @item
-netdev bridge
,id
=@
var{id
}[,br
=@
var{bridge
}][,helper
=@
var{helper
}]
2268 @itemx
-net bridge
[,vlan
=@
var{n
}][,name
=@
var{name
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
2269 Connect a host TAP network
interface to a host bridge device
.
2271 Use the network helper @
var{helper
} to configure the TAP
interface and
2272 attach it to the bridge
. The
default network helper executable is
2273 @file
{/path
/to
/qemu
-bridge
-helper
} and the
default bridge
2274 device is @file
{br0
}.
2279 #launch a QEMU instance with the
default network helper to
2280 #connect a TAP device to bridge br0
2281 qemu
-system
-i386 linux
.img
-net bridge
-net nic
,model
=virtio
2285 #launch a QEMU instance with the
default network helper to
2286 #connect a TAP device to bridge qemubr0
2287 qemu
-system
-i386 linux
.img
-net bridge
,br
=qemubr0
-net nic
,model
=virtio
2290 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
2291 @itemx
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}] [,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
2293 Connect the VLAN @
var{n
} to a remote VLAN
in another QEMU virtual
2294 machine
using a TCP socket connection
. If @option
{listen
} is
2295 specified
, QEMU waits
for incoming connections on @
var{port
}
2296 (@
var{host
} is optional
). @option
{connect
} is used to connect to
2297 another QEMU instance
using the @option
{listen
} option
. @option
{fd
}=@
var{h
}
2298 specifies an already opened TCP socket
.
2302 # launch a first QEMU instance
2303 qemu
-system
-i386 linux
.img \
2304 -net nic
,macaddr
=52:54:00:12:34:56 \
2305 -net socket
,listen
=:1234
2306 # connect the VLAN
0 of
this instance to the VLAN
0
2307 # of the first instance
2308 qemu
-system
-i386 linux
.img \
2309 -net nic
,macaddr
=52:54:00:12:34:57 \
2310 -net socket
,connect
=127.0.0.1:1234
2313 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
2314 @itemx
-net socket
[,vlan
=@
var{n
}][,name
=@
var{name
}][,fd
=@
var{h
}][,mcast
=@
var{maddr
}:@
var{port
}[,localaddr
=@
var{addr
}]]
2316 Create a VLAN @
var{n
} shared with another QEMU virtual
2317 machines
using a UDP multicast socket
, effectively making a bus
for
2318 every QEMU with same multicast address @
var{maddr
} and @
var{port
}.
2322 Several QEMU can be running on different hosts and share same
bus (assuming
2323 correct multicast setup
for these hosts
).
2325 mcast support is compatible with User Mode
Linux (argument @option
{eth@
var{N
}=mcast
}), see
2326 @url
{http
://user-mode-linux.sf.net}.
2328 Use @option
{fd
=h
} to specify an already opened UDP multicast socket
.
2333 # launch one QEMU instance
2334 qemu
-system
-i386 linux
.img \
2335 -net nic
,macaddr
=52:54:00:12:34:56 \
2336 -net socket
,mcast
=230.0.0.1:1234
2337 # launch another QEMU instance on same
"bus"
2338 qemu
-system
-i386 linux
.img \
2339 -net nic
,macaddr
=52:54:00:12:34:57 \
2340 -net socket
,mcast
=230.0.0.1:1234
2341 # launch yet another QEMU instance on same
"bus"
2342 qemu
-system
-i386 linux
.img \
2343 -net nic
,macaddr
=52:54:00:12:34:58 \
2344 -net socket
,mcast
=230.0.0.1:1234
2347 Example (User Mode Linux compat
.):
2349 # launch QEMU
instance (note mcast address selected
2351 qemu-system-i386 linux.img \
2352 -net nic,macaddr=52:54:00:12:34:56 \
2353 -net socket,mcast=239.192.168.1:1102
2355 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2358 Example (send packets from host's
1.2.3.4):
2360 qemu
-system
-i386 linux
.img \
2361 -net nic
,macaddr
=52:54:00:12:34:56 \
2362 -net socket
,mcast
=239.192.168.1:1102,localaddr
=1.2.3.4
2365 @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
}]
2366 @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
}]
2367 Connect VLAN @
var{n
} to L2TPv3 pseudowire
. L2TPv3 (RFC3391
) is a popular
2368 protocol to transport
Ethernet (and other Layer
2) data frames between
2369 two systems
. It is present
in routers
, firewalls and the Linux kernel
2370 (from version
3.3 onwards
).
2372 This transport allows a VM to communicate to another VM
, router or firewall directly
.
2374 @item src
=@
var{srcaddr
}
2375 source
address (mandatory
)
2376 @item dst
=@
var{dstaddr
}
2377 destination
address (mandatory
)
2379 select udp
encapsulation (default is ip
).
2380 @item srcport
=@
var{srcport
}
2382 @item dstport
=@
var{dstport
}
2383 destination udp port
.
2385 force v6
, otherwise defaults to v4
.
2386 @item rxcookie
=@
var{rxcookie
}
2387 @itemx txcookie
=@
var{txcookie
}
2388 Cookies are a weak form of security
in the l2tpv3 specification
.
2389 Their
function is mostly to prevent misconfiguration
. By
default they are
32
2392 Set cookie size to
64 bit instead of the
default 32
2394 Force a
'cut-down' L2TPv3 with no counter as
in
2395 draft
-mkonstan
-l2tpext
-keyed
-ipv6
-tunnel
-00
2397 Work around broken counter handling
in peer
. This may also help on
2398 networks which have packet reorder
.
2399 @item offset
=@
var{offset
}
2400 Add an extra offset between header and data
2402 For example
, to attach a VM running on host
4.3.2.1 via L2TPv3 to the bridge br
-lan
2403 on the remote Linux host
1.2.3.4:
2405 # Setup tunnel on linux host
using raw ip as encapsulation
2407 ip l2tp add tunnel remote
4.3.2.1 local
1.2.3.4 tunnel_id
1 peer_tunnel_id
1 \
2408 encap udp udp_sport
16384 udp_dport
16384
2409 ip l2tp add session tunnel_id
1 name vmtunnel0 session_id \
2410 0xFFFFFFFF peer_session_id
0xFFFFFFFF
2411 ifconfig vmtunnel0 mtu
1500
2412 ifconfig vmtunnel0 up
2413 brctl addif br
-lan vmtunnel0
2417 # launch QEMU instance
- if your network has reorder or is very lossy add
,pincounter
2419 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
2424 @item
-netdev vde
,id
=@
var{id
}[,sock
=@
var{socketpath
}][,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
2425 @itemx
-net vde
[,vlan
=@
var{n
}][,name
=@
var{name
}][,sock
=@
var{socketpath
}] [,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
2426 Connect VLAN @
var{n
} to PORT @
var{n
} of a vde
switch running on host and
2427 listening
for incoming connections on @
var{socketpath
}. Use GROUP @
var{groupname
}
2428 and MODE @
var{octalmode
} to change
default ownership and permissions
for
2429 communication port
. This option is only available
if QEMU has been compiled
2430 with vde support enabled
.
2435 vde_switch
-F
-sock
/tmp
/myswitch
2436 # launch QEMU instance
2437 qemu
-system
-i386 linux
.img
-net nic
-net vde
,sock
=/tmp
/myswitch
2440 @item
-netdev hubport
,id
=@
var{id
},hubid
=@
var{hubid
}
2442 Create a hub port on QEMU
"vlan" @
var{hubid
}.
2444 The hubport netdev lets you connect a NIC to a QEMU
"vlan" instead of a single
2445 netdev
. @code
{-net
} and @code
{-device
} with parameter @option
{vlan
} create the
2446 required hub automatically
.
2448 @item
-netdev vhost
-user
,chardev
=@
var{id
}[,vhostforce
=on|off
][,queues
=n
]
2450 Establish a vhost
-user netdev
, backed by a chardev @
var{id
}. The chardev should
2451 be a unix domain socket backed one
. The vhost
-user uses a specifically defined
2452 protocol to pass vhost ioctl replacement messages to an application on the other
2453 end of the socket
. On non
-MSIX guests
, the feature can be forced with
2454 @
var{vhostforce
}. Use
'queues=@var{n}' to specify the number of queues to
2455 be created
for multiqueue vhost
-user
.
2459 qemu
-m
512 -object memory
-backend
-file
,id
=mem
,size
=512M
,mem
-path
=/hugetlbfs
,share
=on \
2460 -numa node
,memdev
=mem \
2461 -chardev socket
,id
=chr0
,path
=/path
/to
/socket \
2462 -netdev type
=vhost
-user
,id
=net0
,chardev
=chr0 \
2463 -device virtio
-net
-pci
,netdev
=net0
2466 @item
-net dump
[,vlan
=@
var{n
}][,file
=@
var{file
}][,len
=@
var{len
}]
2467 Dump network traffic on VLAN @
var{n
} to file @
var{file
} (@file
{qemu
-vlan0
.pcap
} by
default).
2468 At most @
var{len
} bytes (64k by
default) per packet are stored
. The file format is
2469 libpcap
, so it can be analyzed with tools such as tcpdump or Wireshark
.
2470 Note
: For devices created with
'-netdev', use
'-object filter-dump,...' instead
.
2473 Indicate that no network devices should be configured
. It is used to
2474 override the
default configuration (@option
{-net nic
-net user
}) which
2475 is activated
if no @option
{-net
} options are provided
.
2483 DEFHEADING(Character device options
)
2486 The general form of a character device option is
:
2490 DEF("chardev", HAS_ARG
, QEMU_OPTION_chardev
,
2492 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2493 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2494 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2495 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2496 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2497 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2498 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2499 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2500 " [,logfile=PATH][,logappend=on|off]\n"
2501 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2502 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2503 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2504 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2505 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2506 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2508 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2509 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2511 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2512 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2514 #ifdef CONFIG_BRLAPI
2515 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2517 #
if defined(__linux__
) ||
defined(__sun__
) ||
defined(__FreeBSD__
) \
2518 ||
defined(__NetBSD__
) ||
defined(__OpenBSD__
) ||
defined(__DragonFly__
)
2519 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2520 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2522 #
if defined(__linux__
) ||
defined(__FreeBSD__
) ||
defined(__DragonFly__
)
2523 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2524 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2526 #
if defined(CONFIG_SPICE
)
2527 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2528 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2534 @item
-chardev @
var{backend
} ,id
=@
var{id
} [,mux
=on|off
] [,@
var{options
}]
2555 The specific backend will determine the applicable options
.
2557 Use
"-chardev help" to print all available chardev backend types
.
2559 All devices must have an id
, which can be any string up to
127 characters long
.
2560 It is used to uniquely identify
this device
in other command line directives
.
2562 A character device may be used
in multiplexing mode by multiple front
-ends
.
2563 Specify @option
{mux
=on
} to enable
this mode
.
2564 A multiplexer is a
"1:N" device
, and
here the
"1" end is your specified chardev
2565 backend
, and the
"N" end is the various parts of QEMU that can talk to a chardev
.
2566 If you create a chardev with @option
{id
=myid
} and @option
{mux
=on
}, QEMU will
2567 create a multiplexer with your specified ID
, and you can then configure multiple
2568 front ends to use that chardev ID
for their input
/output
. Up to four different
2569 front ends can be connected to a single multiplexed chardev
. (Without
2570 multiplexing enabled
, a chardev can only be used by a single front end
.)
2571 For instance you could use
this to allow a single stdio chardev to be used by
2572 two serial ports and the QEMU monitor
:
2575 -chardev stdio
,mux
=on
,id
=char0 \
2576 -mon chardev
=char0
,mode
=readline \
2577 -serial chardev
:char0 \
2578 -serial chardev
:char0
2581 You can have more than one multiplexer
in a system configuration
; for instance
2582 you could have a TCP port multiplexed between UART
0 and UART
1, and stdio
2583 multiplexed between the QEMU monitor and a parallel port
:
2586 -chardev stdio
,mux
=on
,id
=char0 \
2587 -mon chardev
=char0
,mode
=readline \
2588 -parallel chardev
:char0 \
2589 -chardev tcp
,...,mux
=on
,id
=char1 \
2590 -serial chardev
:char1 \
2591 -serial chardev
:char1
2594 When you
're using a multiplexed character device, some escape sequences are
2595 interpreted in the input. @xref{mux_keys, Keys in the character backend
2598 Note that some other command line options may implicitly create multiplexed
2599 character backends; for instance @option{-serial mon:stdio} creates a
2600 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2601 and @option{-nographic} also multiplexes the console and the monitor to
2604 There is currently no support for multiplexing in the other direction
2605 (where a single QEMU front end takes input and output from multiple chardevs).
2607 Every backend supports the @option{logfile} option, which supplies the path
2608 to a file to record all data transmitted via the backend. The @option{logappend}
2609 option controls whether the log file will be truncated or appended to when
2612 Further options to each backend are described below.
2614 @item -chardev null ,id=@var{id}
2615 A void device. This device will not emit any data, and will drop any data it
2616 receives. The null backend does not take any options.
2618 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}]
2620 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2621 unix socket will be created if @option{path} is specified. Behaviour is
2622 undefined if TCP options are specified for a unix socket.
2624 @option{server} specifies that the socket shall be a listening socket.
2626 @option{nowait} specifies that QEMU should not block waiting for a client to
2627 connect to a listening socket.
2629 @option{telnet} specifies that traffic on the socket should interpret telnet
2632 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2633 the remote end goes away. qemu will delay this many seconds and then attempt
2634 to reconnect. Zero disables reconnecting, and is the default.
2636 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2637 and specifies the id of the TLS credentials to use for the handshake. The
2638 credentials must be previously created with the @option{-object tls-creds}
2641 TCP and unix socket options are given below:
2645 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2647 @option{host} for a listening socket specifies the local address to be bound.
2648 For a connecting socket species the remote host to connect to. @option{host} is
2649 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2651 @option{port} for a listening socket specifies the local port to be bound. For a
2652 connecting socket specifies the port on the remote host to connect to.
2653 @option{port} can be given as either a port number or a service name.
2654 @option{port} is required.
2656 @option{to} is only relevant to listening sockets. If it is specified, and
2657 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2658 to and including @option{to} until it succeeds. @option{to} must be specified
2661 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2662 If neither is specified the socket may use either protocol.
2664 @option{nodelay} disables the Nagle algorithm.
2666 @item unix options: path=@var{path}
2668 @option{path} specifies the local path of the unix socket. @option{path} is
2673 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2675 Sends all traffic from the guest to a remote host over UDP.
2677 @option{host} specifies the remote host to connect to. If not specified it
2678 defaults to @code{localhost}.
2680 @option{port} specifies the port on the remote host to connect to. @option{port}
2683 @option{localaddr} specifies the local address to bind to. If not specified it
2684 defaults to @code{0.0.0.0}.
2686 @option{localport} specifies the local port to bind to. If not specified any
2687 available local port will be used.
2689 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2690 If neither is specified the device may use either protocol.
2692 @item -chardev msmouse ,id=@var{id}
2694 Forward QEMU's emulated msmouse events to the guest
. @option
{msmouse
} does not
2697 @item
-chardev vc
,id
=@
var{id
} [[,width
=@
var{width
}] [,height
=@
var{height
}]] [[,cols
=@
var{cols
}] [,rows
=@
var{rows
}]]
2699 Connect to a QEMU text console
. @option
{vc
} may optionally be given a specific
2702 @option
{width
} and @option
{height
} specify the width and height respectively of
2703 the console
, in pixels
.
2705 @option
{cols
} and @option
{rows
} specify that the console be sized to fit a text
2706 console with the given dimensions
.
2708 @item
-chardev ringbuf
,id
=@
var{id
} [,size
=@
var{size
}]
2710 Create a ring buffer with fixed size @option
{size
}.
2711 @
var{size
} must be a power of two and defaults to @code
{64K
}.
2713 @item
-chardev file
,id
=@
var{id
} ,path
=@
var{path
}
2715 Log all traffic received from the guest to a file
.
2717 @option
{path
} specifies the path of the file to be opened
. This file will be
2718 created
if it does not already exist
, and overwritten
if it does
. @option
{path
}
2721 @item
-chardev pipe
,id
=@
var{id
} ,path
=@
var{path
}
2723 Create a two
-way connection to the guest
. The behaviour differs slightly between
2724 Windows hosts and other hosts
:
2726 On Windows
, a single duplex pipe will be created at
2727 @file
{\\.pipe\@option
{path
}}.
2729 On other hosts
, 2 pipes will be created called @file
{@option
{path
}.in} and
2730 @file
{@option
{path
}.out
}. Data written to @file
{@option
{path
}.in} will be
2731 received by the guest
. Data written by the guest can be read from
2732 @file
{@option
{path
}.out
}. QEMU will not create these fifos
, and requires them to
2735 @option
{path
} forms part of the pipe path as described above
. @option
{path
} is
2738 @item
-chardev console
,id
=@
var{id
}
2740 Send traffic from the guest to QEMU
's standard output. @option{console} does not
2743 @option{console} is only available on Windows hosts.
2745 @item -chardev serial ,id=@var{id} ,path=@option{path}
2747 Send traffic from the guest to a serial device on the host.
2749 On Unix hosts serial will actually accept any tty device,
2750 not only serial lines.
2752 @option{path} specifies the name of the serial device to open.
2754 @item -chardev pty ,id=@var{id}
2756 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2757 not take any options.
2759 @option{pty} is not available on Windows hosts.
2761 @item -chardev stdio ,id=@var{id} [,signal=on|off]
2762 Connect to standard input and standard output of the QEMU process.
2764 @option{signal} controls if signals are enabled on the terminal, that includes
2765 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2766 default, use @option{signal=off} to disable it.
2768 @item -chardev braille ,id=@var{id}
2770 Connect to a local BrlAPI server. @option{braille} does not take any options.
2772 @item -chardev tty ,id=@var{id} ,path=@var{path}
2774 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2775 DragonFlyBSD hosts. It is an alias for @option{serial}.
2777 @option{path} specifies the path to the tty. @option{path} is required.
2779 @item -chardev parallel ,id=@var{id} ,path=@var{path}
2780 @itemx -chardev parport ,id=@var{id} ,path=@var{path}
2782 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2784 Connect to a local parallel port.
2786 @option{path} specifies the path to the parallel port device. @option{path} is
2789 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2791 @option{spicevmc} is only available when spice support is built in.
2793 @option{debug} debug level for spicevmc
2795 @option{name} name of spice channel to connect to
2797 Connect to a spice virtual machine channel, such as vdiport.
2799 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2801 @option{spiceport} is only available when spice support is built in.
2803 @option{debug} debug level for spicevmc
2805 @option{name} name of spice port to connect to
2807 Connect to a spice port, allowing a Spice client to handle the traffic
2808 identified by a name (preferably a fqdn).
2816 DEFHEADING(Device URL Syntax)
2819 In addition to using normal file images for the emulated storage devices,
2820 QEMU can also use networked resources such as iSCSI devices. These are
2821 specified using a special URL syntax.
2825 iSCSI support allows QEMU to access iSCSI resources directly and use as
2826 images for the guest storage. Both disk and cdrom images are supported.
2828 Syntax for specifying iSCSI LUNs is
2829 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2831 By default qemu will use the iSCSI initiator-name
2832 'iqn
.2008-11.org
.linux
-kvm
[:<name
>]' but this can also be set from the command
2833 line or a configuration file.
2835 Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2836 stalled requests and force a reestablishment of the session. The timeout
2837 is specified in seconds. The default is 0 which means no timeout. Libiscsi
2838 1.15.0 or greater is required for this feature.
2840 Example (without authentication):
2842 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2843 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2844 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2847 Example (CHAP username/password via URL):
2849 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2852 Example (CHAP username/password via environment variables):
2854 LIBISCSI_CHAP_USERNAME="user" \
2855 LIBISCSI_CHAP_PASSWORD="password" \
2856 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2859 iSCSI support is an optional feature of QEMU and only available when
2860 compiled and linked against libiscsi.
2862 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
2863 "-iscsi [user=user][,password=password]\n"
2864 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2865 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2866 " [,timeout=timeout]\n"
2867 " iSCSI session parameters\n", QEMU_ARCH_ALL)
2870 iSCSI parameters such as username and password can also be specified via
2871 a configuration file. See qemu-doc for more information and examples.
2874 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2875 as Unix Domain Sockets.
2877 Syntax for specifying a NBD device using TCP
2878 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2880 Syntax for specifying a NBD device using Unix Domain Sockets
2881 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2886 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2889 Example for Unix Domain Sockets
2891 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2895 QEMU supports SSH (Secure Shell) access to remote disks.
2899 qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2900 qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2903 Currently authentication must be done using ssh-agent. Other
2904 authentication methods may be supported in future.
2907 Sheepdog is a distributed storage system for QEMU.
2908 QEMU supports using either local sheepdog devices or remote networked
2911 Syntax for specifying a sheepdog device
2913 sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2918 qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2921 See also @url{https://sheepdog.github.io/sheepdog/}.
2924 GlusterFS is a user space distributed file system.
2925 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2926 TCP, Unix Domain Sockets and RDMA transport protocols.
2928 Syntax for specifying a VM disk image on GlusterFS volume is
2932 gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]
2935 'json
:@
{"driver":"qcow2","file":@
{"driver":"gluster","volume":"testvol","path":"a.img","debug":N
,"logfile":"...",
2936 @
"server":[@
{"type":"tcp","host":"...","port":"..."@
},
2937 @ @
{"type":"unix","socket":"..."@
}]@
}@
}'
2944 qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img,
2945 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log
2948 qemu-system-x86_64 'json
:@
{"driver":"qcow2",
2949 @
"file":@
{"driver":"gluster",
2950 @
"volume":"testvol","path":"a.img",
2951 @
"debug":9,"logfile":"/var/log/qemu-gluster.log",
2952 @
"server":[@
{"type":"tcp","host":"1.2.3.4","port":24007@
},
2953 @ @
{"type":"unix","socket":"/var/run/glusterd.socket"@
}]@
}@
}'
2954 qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
2955 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log,
2956 @ file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
2957 @ file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket
2960 See also @url{http://www.gluster.org}.
2962 @item HTTP/HTTPS/FTP/FTPS
2963 QEMU supports read-only access to files accessed over http(s) and ftp(s).
2965 Syntax using a single filename:
2967 <protocol>://[<username>[:<password>]@@]<host>/<path>
2973 'http
', 'https
', 'ftp
', or 'ftps
'.
2976 Optional username for authentication to the remote server.
2979 Optional password for authentication to the remote server.
2982 Address of the remote server.
2985 Path on the remote server, including any query string.
2988 The following options are also supported:
2991 The full URL when passing options to the driver explicitly.
2994 The amount of data to read ahead with each range request to the remote server.
2995 This value may optionally have the suffix 'T
', 'G
', 'M
', 'K
', 'k
' or 'b
'. If it
2996 does not have a suffix, it will be assumed to be in bytes. The value must be a
2997 multiple of 512 bytes. It defaults to 256k.
3000 Whether to verify the remote server's certificate when connecting over SSL
. It
3001 can have the value
'on' or
'off'. It defaults to
'on'.
3004 Send
this cookie (it can also be a list of cookies separated by
';') with
3005 each outgoing request
. Only supported when
using protocols such as HTTP
3006 which support cookies
, otherwise ignored
.
3009 Set the timeout
in seconds of the CURL connection
. This timeout is the time
3010 that CURL waits
for a response from the remote server to get the size of the
3011 image to be downloaded
. If not set
, the
default timeout of
5 seconds is used
.
3014 Note that when passing options to qemu explicitly
, @option
{driver
} is the value
3017 Example
: boot from a remote Fedora
20 live ISO image
3019 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
3021 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
3024 Example
: boot from a remote Fedora
20 cloud image
using a local overlay
for
3025 writes
, copy
-on
-read
, and a readahead of
64k
3027 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
3029 qemu
-system
-x86_64
-drive file
=/tmp
/Fedora
-x86_64
-20-20131211.1-sda
.qcow2
,copy
-on
-read
=on
3032 Example
: boot from an image stored on a VMware vSphere server with a self
-signed
3033 certificate
using a local overlay
for writes
, a readahead of
64k and a timeout
3036 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
3038 qemu
-system
-x86_64
-drive file
=/tmp
/test
.qcow2
3046 DEFHEADING(Bluetooth(R
) options
)
3051 DEF("bt", HAS_ARG
, QEMU_OPTION_bt
, \
3052 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
3053 "-bt hci,host[:id]\n" \
3054 " use host's HCI with the given name\n" \
3055 "-bt hci[,vlan=n]\n" \
3056 " emulate a standard HCI in virtual scatternet 'n'\n" \
3057 "-bt vhci[,vlan=n]\n" \
3058 " add host computer to virtual scatternet 'n' using VHCI\n" \
3059 "-bt device:dev[,vlan=n]\n" \
3060 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
3065 Defines the
function of the corresponding Bluetooth HCI
. -bt options
3066 are matched with the HCIs present
in the chosen machine type
. For
3067 example when emulating a machine with only one HCI built into it
, only
3068 the first @code
{-bt hci
[...]} option is valid and defines the HCI
's
3069 logic. The Transport Layer is decided by the machine type. Currently
3070 the machines @code{n800} and @code{n810} have one HCI and all other
3074 The following three types are recognized:
3078 (default) The corresponding Bluetooth HCI assumes no internal logic
3079 and will not respond to any HCI commands or emit events.
3081 @item -bt hci,host[:@var{id}]
3082 (@code{bluez} only) The corresponding HCI passes commands / events
3083 to / from the physical HCI identified by the name @var{id} (default:
3084 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
3085 capable systems like Linux.
3087 @item -bt hci[,vlan=@var{n}]
3088 Add a virtual, standard HCI that will participate in the Bluetooth
3089 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
3090 VLANs, devices inside a bluetooth network @var{n} can only communicate
3091 with other devices in the same network (scatternet).
3094 @item -bt vhci[,vlan=@var{n}]
3095 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
3096 to the host bluetooth stack instead of to the emulated target. This
3097 allows the host and target machines to participate in a common scatternet
3098 and communicate. Requires the Linux @code{vhci} driver installed. Can
3099 be used as following:
3102 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
3105 @item -bt device:@var{dev}[,vlan=@var{n}]
3106 Emulate a bluetooth device @var{dev} and place it in network @var{n}
3107 (default @code{0}). QEMU can only emulate one type of bluetooth devices
3112 Virtual wireless keyboard implementing the HIDP bluetooth profile.
3122 DEFHEADING(TPM device options)
3124 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
3125 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
3126 " use path to provide path to a character device; default is /dev/tpm0\n"
3127 " use cancel-path to provide path to TPM's cancel sysfs entry
; if\n"
3128 " not provided it will be searched
for in /sys
/class/misc
/tpm?
/device
\n"
3129 "-tpmdev emulator
,id
=id
,chardev
=dev
\n"
3130 " configure the TPM device
using chardev backend
\n",
3134 The general form of a TPM device option is:
3137 @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
3139 Backend type must be either one of the following:
3140 @option{passthrough}, @option{emulator}.
3142 The specific backend type will determine the applicable options.
3143 The @code{-tpmdev} option creates the TPM backend and requires a
3144 @code{-device} option that specifies the TPM frontend interface model.
3146 Options to each backend are described below.
3148 Use 'help' to print all available TPM backend types.
3153 @item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
3155 (Linux-host only) Enable access to the host's TPM using the passthrough
3158 @option{path} specifies the path to the host's TPM device, i.e., on
3159 a Linux host this would be @code{/dev/tpm0}.
3160 @option{path} is optional and by default @code{/dev/tpm0} is used.
3162 @option{cancel-path} specifies the path to the host TPM device's sysfs
3163 entry allowing for cancellation of an ongoing TPM command.
3164 @option{cancel-path} is optional and by default QEMU will search for the
3167 Some notes about using the host's TPM with the passthrough driver:
3169 The TPM device accessed by the passthrough driver must not be
3170 used by any other application on the host.
3172 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
3173 the VM's firmware (BIOS/UEFI) will not be able to initialize the
3174 TPM again and may therefore not show a TPM-specific menu that would
3175 otherwise allow the user to configure the TPM, e.g., allow the user to
3176 enable/disable or activate/deactivate the TPM.
3177 Further, if TPM ownership is released from within a VM then the host's TPM
3178 will get disabled and deactivated. To enable and activate the
3179 TPM again afterwards, the host has to be rebooted and the user is
3180 required to enter the firmware's menu to enable and activate the TPM.
3181 If the TPM is left disabled and/or deactivated most TPM commands will fail.
3183 To create a passthrough TPM use the following two options:
3185 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
3187 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
3188 @code{tpmdev=tpm0} in the device option.
3190 @item -tpmdev emulator, id=@var{id}, chardev=@var{dev}
3192 (Linux-host only) Enable access to a TPM emulator using Unix domain socket based
3195 @option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
3197 To create a TPM emulator backend device with chardev socket backend:
3200 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
3212 DEFHEADING(Linux/Multiboot boot specific)
3215 When using these options, you can use a given Linux or Multiboot
3216 kernel without installing it in the disk image. It can be useful
3217 for easier testing of various kernels.
3222 DEF("kernel
", HAS_ARG, QEMU_OPTION_kernel, \
3223 "-kernel bzImage use
'bzImage' as kernel image
\n", QEMU_ARCH_ALL)
3225 @item -kernel @var{bzImage}
3227 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
3228 or in multiboot format.
3231 DEF("append
", HAS_ARG, QEMU_OPTION_append, \
3232 "-append cmdline use
'cmdline' as kernel command line
\n", QEMU_ARCH_ALL)
3234 @item -append @var{cmdline}
3236 Use @var{cmdline} as kernel command line
3239 DEF("initrd
", HAS_ARG, QEMU_OPTION_initrd, \
3240 "-initrd file use
'file' as initial ram disk
\n", QEMU_ARCH_ALL)
3242 @item -initrd @var{file}
3244 Use @var{file} as initial ram disk.
3246 @item -initrd "@
var{file1
} arg
=foo
,@
var{file2
}"
3248 This syntax is only available with multiboot.
3250 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3254 DEF("dtb
", HAS_ARG, QEMU_OPTION_dtb, \
3255 "-dtb file use
'file' as device tree image
\n", QEMU_ARCH_ALL)
3257 @item -dtb @var{file}
3259 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3268 DEFHEADING(Debug/Expert options)
3273 DEF("fw_cfg
", HAS_ARG, QEMU_OPTION_fwcfg,
3274 "-fw_cfg
[name
=]<name
>,file
=<file
>\n"
3275 " add named fw_cfg entry with contents from file
\n"
3276 "-fw_cfg
[name
=]<name
>,string
=<str
>\n"
3277 " add named fw_cfg entry with contents from string
\n",
3281 @item -fw_cfg [name=]@var{name},file=@var{file}
3283 Add named fw_cfg entry with contents from file @var{file}.
3285 @item -fw_cfg [name=]@var{name},string=@var{str}
3286 Add named fw_cfg entry with contents from string @var{str}.
3288 The terminating NUL character of the contents of @var{str} will not be
3289 included as part of the fw_cfg item data. To insert contents with
3290 embedded NUL characters, you have to use the @var{file} parameter.
3292 The fw_cfg entries are passed by QEMU through to the guest.
3296 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3298 creates an fw_cfg entry named opt/com.mycompany/blob with contents
3303 DEF("serial
", HAS_ARG, QEMU_OPTION_serial, \
3304 "-serial dev redirect the serial port to char device
'dev'\n",
3307 @item -serial @var{dev}
3309 Redirect the virtual serial port to host character device
3310 @var{dev}. The default device is @code{vc} in graphical mode and
3311 @code{stdio} in non graphical mode.
3313 This option can be used several times to simulate up to 4 serial
3316 Use @code{-serial none} to disable all serial ports.
3318 Available character devices are:
3320 @item vc[:@var{W}x@var{H}]
3321 Virtual console. Optionally, a width and height can be given in pixel with
3325 It is also possible to specify width or height in characters:
3330 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3332 No device is allocated.
3335 @item chardev:@var{id}
3336 Use a named character device defined with the @code{-chardev} option.
3338 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3339 parameters are set according to the emulated ones.
3340 @item /dev/parport@var{N}
3341 [Linux only, parallel port only] Use host parallel port
3342 @var{N}. Currently SPP and EPP parallel port features can be used.
3343 @item file:@var{filename}
3344 Write output to @var{filename}. No character can be read.
3346 [Unix only] standard input/output
3347 @item pipe:@var{filename}
3348 name pipe @var{filename}
3350 [Windows only] Use host serial port @var{n}
3351 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3352 This implements UDP Net Console.
3353 When @var{remote_host} or @var{src_ip} are not specified
3354 they default to @code{0.0.0.0}.
3355 When not using a specified @var{src_port} a random port is automatically chosen.
3357 If you just want a simple readonly console you can use @code{netcat} or
3358 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3359 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3360 will appear in the netconsole session.
3362 If you plan to send characters back via netconsole or you want to stop
3363 and start QEMU a lot of times, you should have QEMU use the same
3364 source port each time by using something like @code{-serial
3365 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3366 version of netcat which can listen to a TCP port and send and receive
3367 characters via udp. If you have a patched version of netcat which
3368 activates telnet remote echo and single char transfer, then you can
3369 use the following options to set up a netcat redirector to allow
3370 telnet on port 5555 to access the QEMU port.
3373 -serial udp::4555@@:4556
3374 @item netcat options:
3375 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3376 @item telnet options:
3380 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3381 The TCP Net Console has two modes of operation. It can send the serial
3382 I/O to a location or wait for a connection from a location. By default
3383 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3384 the @var{server} option QEMU will wait for a client socket application
3385 to connect to the port before continuing, unless the @code{nowait}
3386 option was specified. The @code{nodelay} option disables the Nagle buffering
3387 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3388 set, if the connection goes down it will attempt to reconnect at the
3389 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3390 one TCP connection at a time is accepted. You can use @code{telnet} to
3391 connect to the corresponding character device.
3393 @item Example to send tcp console to 192.168.0.2 port 4444
3394 -serial tcp:192.168.0.2:4444
3395 @item Example to listen and wait on port 4444 for connection
3396 -serial tcp::4444,server
3397 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3398 -serial tcp:192.168.0.100:4444,server,nowait
3401 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3402 The telnet protocol is used instead of raw tcp sockets. The options
3403 work the same as if you had specified @code{-serial tcp}. The
3404 difference is that the port acts like a telnet server or client using
3405 telnet option negotiation. This will also allow you to send the
3406 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3407 sequence. Typically in unix telnet you do it with Control-] and then
3408 type "send
break" followed by pressing the enter key.
3410 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3411 A unix domain socket is used instead of a tcp socket. The option works the
3412 same as if you had specified @code{-serial tcp} except the unix domain socket
3413 @var{path} is used for connections.
3415 @item mon:@var{dev_string}
3416 This is a special option to allow the monitor to be multiplexed onto
3417 another serial port. The monitor is accessed with key sequence of
3418 @key{Control-a} and then pressing @key{c}.
3419 @var{dev_string} should be any one of the serial devices specified
3420 above. An example to multiplex the monitor onto a telnet server
3421 listening on port 4444 would be:
3423 @item -serial mon:telnet::4444,server,nowait
3425 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3426 QEMU any more but will be passed to the guest instead.
3429 Braille device. This will use BrlAPI to display the braille output on a real
3433 Three button serial mouse. Configure the guest to use Microsoft protocol.
3437 DEF("parallel
", HAS_ARG, QEMU_OPTION_parallel, \
3438 "-parallel dev redirect the parallel port to char device
'dev'\n",
3441 @item -parallel @var{dev}
3443 Redirect the virtual parallel port to host device @var{dev} (same
3444 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3445 be used to use hardware devices connected on the corresponding host
3448 This option can be used several times to simulate up to 3 parallel
3451 Use @code{-parallel none} to disable all parallel ports.
3454 DEF("monitor
", HAS_ARG, QEMU_OPTION_monitor, \
3455 "-monitor dev redirect the monitor to char device
'dev'\n",
3458 @item -monitor @var{dev}
3460 Redirect the monitor to host device @var{dev} (same devices as the
3462 The default device is @code{vc} in graphical mode and @code{stdio} in
3464 Use @code{-monitor none} to disable the default monitor.
3466 DEF("qmp
", HAS_ARG, QEMU_OPTION_qmp, \
3467 "-qmp dev like
-monitor but opens
in 'control' mode
\n",
3470 @item -qmp @var{dev}
3472 Like -monitor but opens in 'control' mode.
3474 DEF("qmp
-pretty
", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3475 "-qmp
-pretty dev like
-qmp but uses pretty JSON formatting
\n",
3478 @item -qmp-pretty @var{dev}
3480 Like -qmp but uses pretty JSON formatting.
3483 DEF("mon
", HAS_ARG, QEMU_OPTION_mon, \
3484 "-mon
[chardev
=]name
[,mode
=readline|control
]\n", QEMU_ARCH_ALL)
3486 @item -mon [chardev=]name[,mode=readline|control]
3488 Setup monitor on chardev @var{name}.
3491 DEF("debugcon
", HAS_ARG, QEMU_OPTION_debugcon, \
3492 "-debugcon dev redirect the debug console to char device
'dev'\n",
3495 @item -debugcon @var{dev}
3497 Redirect the debug console to host device @var{dev} (same devices as the
3498 serial port). The debug console is an I/O port which is typically port
3499 0xe9; writing to that I/O port sends output to this device.
3500 The default device is @code{vc} in graphical mode and @code{stdio} in
3504 DEF("pidfile
", HAS_ARG, QEMU_OPTION_pidfile, \
3505 "-pidfile file write PID to
'file'\n", QEMU_ARCH_ALL)
3507 @item -pidfile @var{file}
3509 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3513 DEF("singlestep
", 0, QEMU_OPTION_singlestep, \
3514 "-singlestep always run
in singlestep mode
\n", QEMU_ARCH_ALL)
3518 Run the emulation in single step mode.
3521 DEF("S
", 0, QEMU_OPTION_S, \
3522 "-S freeze CPU at
startup (use
'c' to start execution
)\n",
3527 Do not start CPU at startup (you must type 'c' in the monitor).
3530 DEF("realtime
", HAS_ARG, QEMU_OPTION_realtime,
3531 "-realtime
[mlock
=on|off
]\n"
3532 " run qemu with realtime features
\n"
3533 " mlock
=on|off controls mlock
support (default: on
)\n",
3536 @item -realtime mlock=on|off
3538 Run qemu with realtime features.
3539 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3540 (enabled by default).
3543 DEF("gdb
", HAS_ARG, QEMU_OPTION_gdb, \
3544 "-gdb dev wait
for gdb connection on
'dev'\n", QEMU_ARCH_ALL)
3546 @item -gdb @var{dev}
3548 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3549 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3550 stdio are reasonable use case. The latter is allowing to start QEMU from
3551 within gdb and establish the connection via a pipe:
3553 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3557 DEF("s
", 0, QEMU_OPTION_s, \
3558 "-s shorthand
for -gdb tcp
::" DEFAULT_GDBSTUB_PORT "\n",
3563 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3564 (@pxref{gdb_usage}).
3567 DEF("d
", HAS_ARG, QEMU_OPTION_d, \
3568 "-d item1
,... enable logging of specified
items (use
'-d help' for a list of log items
)\n",
3571 @item -d @var{item1}[,...]
3573 Enable logging of specified items. Use '-d help' for a list of log items.
3576 DEF("D
", HAS_ARG, QEMU_OPTION_D, \
3577 "-D logfile output log to
logfile (default stderr
)\n",
3580 @item -D @var{logfile}
3582 Output log in @var{logfile} instead of to stderr
3585 DEF("dfilter
", HAS_ARG, QEMU_OPTION_DFILTER, \
3586 "-dfilter range
,.. filter debug output to range of
addresses (useful
for -d cpu
,exec
,etc
..)\n",
3589 @item -dfilter @var{range1}[,...]
3591 Filter debug output to that relevant to a range of target addresses. The filter
3592 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3593 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3594 addresses and sizes required. For example:
3596 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3598 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3599 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3600 block starting at 0xffffffc00005f000.
3603 DEF("L
", HAS_ARG, QEMU_OPTION_L, \
3604 "-L path set the directory
for the BIOS
, VGA BIOS and keymaps
\n",
3609 Set the directory for the BIOS, VGA BIOS and keymaps.
3611 To list all the data directories, use @code{-L help}.
3614 DEF("bios
", HAS_ARG, QEMU_OPTION_bios, \
3615 "-bios file set the filename
for the BIOS
\n", QEMU_ARCH_ALL)
3617 @item -bios @var{file}
3619 Set the filename for the BIOS.
3622 DEF("enable
-kvm
", 0, QEMU_OPTION_enable_kvm, \
3623 "-enable
-kvm enable KVM full virtualization support
\n", QEMU_ARCH_ALL)
3627 Enable KVM full virtualization support. This option is only available
3628 if KVM support is enabled when compiling.
3631 DEF("enable
-hax
", 0, QEMU_OPTION_enable_hax, \
3632 "-enable
-hax enable HAX virtualization support
\n", QEMU_ARCH_I386)
3636 Enable HAX (Hardware-based Acceleration eXecution) support. This option
3637 is only available if HAX support is enabled when compiling. HAX is only
3638 applicable to MAC and Windows platform, and thus does not conflict with
3642 DEF("xen
-domid
", HAS_ARG, QEMU_OPTION_xen_domid,
3643 "-xen
-domid id specify xen guest domain id
\n", QEMU_ARCH_ALL)
3644 DEF("xen
-create
", 0, QEMU_OPTION_xen_create,
3645 "-xen
-create create domain
using xen hypercalls
, bypassing xend
\n"
3646 " warning
: should not be used when xend is
in use
\n",
3648 DEF("xen
-attach
", 0, QEMU_OPTION_xen_attach,
3649 "-xen
-attach attach to existing xen domain
\n"
3650 " xend will use
this when starting QEMU
\n",
3652 DEF("xen
-domid
-restrict
", 0, QEMU_OPTION_xen_domid_restrict,
3653 "-xen
-domid
-restrict restrict set of available xen operations
\n"
3654 " to specified domain id
. (Does not affect
\n"
3655 " xenpv machine type
).\n",
3658 @item -xen-domid @var{id}
3660 Specify xen guest domain @var{id} (XEN only).
3663 Create domain using xen hypercalls, bypassing xend.
3664 Warning: should not be used when xend is in use (XEN only).
3667 Attach to existing xen domain.
3668 xend will use this when starting QEMU (XEN only).
3669 @findex -xen-domid-restrict
3670 Restrict set of available xen operations to specified domain id (XEN only).
3673 DEF("no
-reboot
", 0, QEMU_OPTION_no_reboot, \
3674 "-no
-reboot exit instead of rebooting
\n", QEMU_ARCH_ALL)
3678 Exit instead of rebooting.
3681 DEF("no
-shutdown
", 0, QEMU_OPTION_no_shutdown, \
3682 "-no
-shutdown stop before shutdown
\n", QEMU_ARCH_ALL)
3685 @findex -no-shutdown
3686 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3687 This allows for instance switching to monitor to commit changes to the
3691 DEF("loadvm
", HAS_ARG, QEMU_OPTION_loadvm, \
3692 "-loadvm
[tag|id
]\n" \
3693 " start right away with a saved
state (loadvm
in monitor
)\n",
3696 @item -loadvm @var{file}
3698 Start right away with a saved state (@code{loadvm} in monitor)
3702 DEF("daemonize
", 0, QEMU_OPTION_daemonize, \
3703 "-daemonize daemonize QEMU after initializing
\n", QEMU_ARCH_ALL)
3708 Daemonize the QEMU process after initialization. QEMU will not detach from
3709 standard IO until it is ready to receive connections on any of its devices.
3710 This option is a useful way for external programs to launch QEMU without having
3711 to cope with initialization race conditions.
3714 DEF("option
-rom
", HAS_ARG, QEMU_OPTION_option_rom, \
3715 "-option
-rom rom load a file
, rom
, into the option ROM space
\n",
3718 @item -option-rom @var{file}
3720 Load the contents of @var{file} as an option ROM.
3721 This option is useful to load things like EtherBoot.
3724 HXCOMM Silently ignored for compatibility
3725 DEF("clock
", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3727 HXCOMM Options deprecated by -rtc
3728 DEF("localtime
", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3729 DEF("startdate
", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3731 DEF("rtc
", HAS_ARG, QEMU_OPTION_rtc, \
3732 "-rtc
[base
=utc|localtime|date
][,clock
=host|rt|vm
][,driftfix
=none|slew
]\n" \
3733 " set the RTC base and clock
, enable drift fix
for clock
ticks (x86 only
)\n",
3738 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3740 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3741 UTC or local time, respectively. @code{localtime} is required for correct date in
3742 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3743 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3745 By default the RTC is driven by the host system time. This allows using of the
3746 RTC as accurate reference clock inside the guest, specifically if the host
3747 time is smoothly following an accurate external reference clock, e.g. via NTP.
3748 If you want to isolate the guest time from the host, you can set @option{clock}
3749 to @code{rt} instead. To even prevent it from progressing during suspension,
3750 you can set it to @code{vm}.
3752 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3753 specifically with Windows' ACPI HAL. This option will try to figure out how
3754 many timer interrupts were not processed by the Windows guest and will
3758 DEF("icount
", HAS_ARG, QEMU_OPTION_icount, \
3759 "-icount
[shift
=N|auto
][,align
=on|off
][,sleep
=on|off
,rr
=record|replay
,rrfile
=<filename
>,rrsnapshot
=<snapshot
>]\n" \
3760 " enable virtual instruction counter with
2^N clock ticks per
\n" \
3761 " instruction
, enable aligning the host and virtual clocks
\n" \
3762 " or disable real time cpu sleeping
\n", QEMU_ARCH_ALL)
3764 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3766 Enable virtual instruction counter. The virtual cpu will execute one
3767 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3768 then the virtual cpu speed will be automatically adjusted to keep virtual
3769 time within a few seconds of real time.
3771 When the virtual cpu is sleeping, the virtual time will advance at default
3772 speed unless @option{sleep=on|off} is specified.
3773 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3774 instantly whenever the virtual cpu goes to sleep mode and will not advance
3775 if no timer is enabled. This behavior give deterministic execution times from
3776 the guest point of view.
3778 Note that while this option can give deterministic behavior, it does not
3779 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3780 order cores with complex cache hierarchies. The number of instructions
3781 executed often has little or no correlation with actual performance.
3783 @option{align=on} will activate the delay algorithm which will try
3784 to synchronise the host clock and the virtual clock. The goal is to
3785 have a guest running at the real frequency imposed by the shift option.
3786 Whenever the guest clock is behind the host clock and if
3787 @option{align=on} is specified then we print a message to the user
3788 to inform about the delay.
3789 Currently this option does not work when @option{shift} is @code{auto}.
3790 Note: The sync algorithm will work for those shift values for which
3791 the guest clock runs ahead of the host clock. Typically this happens
3792 when the shift value is high (how high depends on the host machine).
3794 When @option{rr} option is specified deterministic record/replay is enabled.
3795 Replay log is written into @var{filename} file in record mode and
3796 read from this file in replay mode.
3798 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3799 at the start of execution recording. In replay mode this option is used
3800 to load the initial VM state.
3803 DEF("watchdog
", HAS_ARG, QEMU_OPTION_watchdog, \
3804 "-watchdog model
\n" \
3805 " enable virtual hardware watchdog
[default=none
]\n",
3808 @item -watchdog @var{model}
3810 Create a virtual hardware watchdog device. Once enabled (by a guest
3811 action), the watchdog must be periodically polled by an agent inside
3812 the guest or else the guest will be restarted. Choose a model for
3813 which your guest has drivers.
3815 The @var{model} is the model of hardware watchdog to emulate. Use
3816 @code{-watchdog help} to list available hardware models. Only one
3817 watchdog can be enabled for a guest.
3819 The following models may be available:
3822 iBASE 700 is a very simple ISA watchdog with a single timer.
3824 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3825 dual-timer watchdog.
3827 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3828 (currently KVM only).
3832 DEF("watchdog
-action
", HAS_ARG, QEMU_OPTION_watchdog_action, \
3833 "-watchdog
-action reset|shutdown|poweroff|pause|debug|none
\n" \
3834 " action when watchdog fires
[default=reset
]\n",
3837 @item -watchdog-action @var{action}
3838 @findex -watchdog-action
3840 The @var{action} controls what QEMU will do when the watchdog timer
3843 @code{reset} (forcefully reset the guest).
3844 Other possible actions are:
3845 @code{shutdown} (attempt to gracefully shutdown the guest),
3846 @code{poweroff} (forcefully poweroff the guest),
3847 @code{pause} (pause the guest),
3848 @code{debug} (print a debug message and continue), or
3849 @code{none} (do nothing).
3851 Note that the @code{shutdown} action requires that the guest responds
3852 to ACPI signals, which it may not be able to do in the sort of
3853 situations where the watchdog would have expired, and thus
3854 @code{-watchdog-action shutdown} is not recommended for production use.
3859 @item -watchdog i6300esb -watchdog-action pause
3860 @itemx -watchdog ib700
3864 DEF("echr
", HAS_ARG, QEMU_OPTION_echr, \
3865 "-echr chr set terminal escape character instead of ctrl
-a
\n",
3869 @item -echr @var{numeric_ascii_value}
3871 Change the escape character used for switching to the monitor when using
3872 monitor and serial sharing. The default is @code{0x01} when using the
3873 @code{-nographic} option. @code{0x01} is equal to pressing
3874 @code{Control-a}. You can select a different character from the ascii
3875 control keys where 1 through 26 map to Control-a through Control-z. For
3876 instance you could use the either of the following to change the escape
3877 character to Control-t.
3884 DEF("virtioconsole
", HAS_ARG, QEMU_OPTION_virtiocon, \
3885 "-virtioconsole c
\n" \
3886 " set virtio console
\n", QEMU_ARCH_ALL)
3888 @item -virtioconsole @var{c}
3889 @findex -virtioconsole
3892 This option is maintained for backward compatibility.
3894 Please use @code{-device virtconsole} for the new way of invocation.
3897 DEF("show
-cursor
", 0, QEMU_OPTION_show_cursor, \
3898 "-show
-cursor show cursor
\n", QEMU_ARCH_ALL)
3901 @findex -show-cursor
3905 DEF("tb
-size
", HAS_ARG, QEMU_OPTION_tb_size, \
3906 "-tb
-size n set TB size
\n", QEMU_ARCH_ALL)
3908 @item -tb-size @var{n}
3913 DEF("incoming
", HAS_ARG, QEMU_OPTION_incoming, \
3914 "-incoming tcp
:[host
]:port
[,to
=maxport
][,ipv4
][,ipv6
]\n" \
3915 "-incoming rdma
:host
:port
[,ipv4
][,ipv6
]\n" \
3916 "-incoming unix
:socketpath
\n" \
3917 " prepare
for incoming migration
, listen on
\n" \
3918 " specified protocol and socket address
\n" \
3919 "-incoming fd
:fd
\n" \
3920 "-incoming exec
:cmdline
\n" \
3921 " accept incoming migration on given file descriptor
\n" \
3922 " or from given external command
\n" \
3923 "-incoming defer
\n" \
3924 " wait
for the URI to be specified via migrate_incoming
\n",
3927 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3928 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3930 Prepare for incoming migration, listen on a given tcp port.
3932 @item -incoming unix:@var{socketpath}
3933 Prepare for incoming migration, listen on a given unix socket.
3935 @item -incoming fd:@var{fd}
3936 Accept incoming migration from a given filedescriptor.
3938 @item -incoming exec:@var{cmdline}
3939 Accept incoming migration as an output from specified external command.
3941 @item -incoming defer
3942 Wait for the URI to be specified via migrate_incoming. The monitor can
3943 be used to change settings (such as migration parameters) prior to issuing
3944 the migrate_incoming to allow the migration to begin.
3947 DEF("only
-migratable
", 0, QEMU_OPTION_only_migratable, \
3948 "-only
-migratable allow only migratable devices
\n", QEMU_ARCH_ALL)
3950 @item -only-migratable
3951 @findex -only-migratable
3952 Only allow migratable devices. Devices will not be allowed to enter an
3956 DEF("nodefaults
", 0, QEMU_OPTION_nodefaults, \
3957 "-nodefaults don
't create default devices\n", QEMU_ARCH_ALL)
3961 Don't create
default devices
. Normally
, QEMU sets the
default devices like serial
3962 port
, parallel port
, virtual console
, monitor device
, VGA adapter
, floppy and
3963 CD
-ROM drive and others
. The @code
{-nodefaults
} option will disable all those
3968 DEF("chroot", HAS_ARG
, QEMU_OPTION_chroot
, \
3969 "-chroot dir chroot to dir just before starting the VM\n",
3973 @item
-chroot @
var{dir
}
3975 Immediately before starting guest execution
, chroot to the specified
3976 directory
. Especially useful
in combination with
-runas
.
3980 DEF("runas", HAS_ARG
, QEMU_OPTION_runas
, \
3981 "-runas user change to user id user just before starting the VM\n",
3985 @item
-runas @
var{user
}
3987 Immediately before starting guest execution
, drop root privileges
, switching
3988 to the specified user
.
3991 DEF("prom-env", HAS_ARG
, QEMU_OPTION_prom_env
,
3992 "-prom-env variable=value\n"
3993 " set OpenBIOS nvram variables\n",
3994 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
3996 @item
-prom
-env @
var{variable
}=@
var{value
}
3998 Set OpenBIOS nvram @
var{variable
} to given @
var{value
} (PPC
, SPARC only
).
4000 DEF("semihosting", 0, QEMU_OPTION_semihosting
,
4001 "-semihosting semihosting mode\n",
4002 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
4006 @findex
-semihosting
4007 Enable semihosting
mode (ARM
, M68K
, Xtensa
, MIPS only
).
4009 DEF("semihosting-config", HAS_ARG
, QEMU_OPTION_semihosting_config
,
4010 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
4011 " semihosting configuration\n",
4012 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
4015 @item
-semihosting
-config
[enable
=on|off
][,target
=native|gdb|auto
][,arg
=str
[,...]]
4016 @findex
-semihosting
-config
4017 Enable and configure
semihosting (ARM
, M68K
, Xtensa
, MIPS only
).
4019 @item target
=@code
{native|gdb|auto
}
4020 Defines where the semihosting calls will be addressed
, to
QEMU (@code
{native
})
4021 or to
GDB (@code
{gdb
}). The
default is @code
{auto
}, which means @code
{gdb
}
4022 during debug sessions and @code
{native
} otherwise
.
4023 @item arg
=@
var{str1
},arg
=@
var{str2
},...
4024 Allows the user to pass input arguments
, and can be used multiple times to build
4025 up a list
. The old
-style @code
{-kernel
}/@code
{-append
} method of passing a
4026 command line is still supported
for backward compatibility
. If both the
4027 @code
{--semihosting
-config arg
} and the @code
{-kernel
}/@code
{-append
} are
4028 specified
, the former is passed to semihosting as it always takes precedence
.
4031 DEF("old-param", 0, QEMU_OPTION_old_param
,
4032 "-old-param old param mode\n", QEMU_ARCH_ARM
)
4035 @findex
-old
-param (ARM
)
4036 Old param
mode (ARM only
).
4039 DEF("sandbox", HAS_ARG
, QEMU_OPTION_sandbox
, \
4040 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
4041 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
4042 " Enable seccomp mode 2 system call filter (default 'off').\n" \
4043 " use 'obsolete' to allow obsolete system calls that are provided\n" \
4044 " by the kernel, but typically no longer used by modern\n" \
4045 " C library implementations.\n" \
4046 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
4047 " its privileges by blacklisting all set*uid|gid system calls.\n" \
4048 " The value 'children' will deny set*uid|gid system calls for\n" \
4049 " main QEMU process but will allow forks and execves to run unprivileged\n" \
4050 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
4051 " blacklisting *fork and execve\n" \
4052 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
4055 @item
-sandbox @
var{arg
}[,obsolete
=@
var{string
}][,elevateprivileges
=@
var{string
}][,spawn
=@
var{string
}][,resourcecontrol
=@
var{string
}]
4057 Enable Seccomp mode
2 system call filter
. 'on' will enable syscall filtering and
'off' will
4058 disable it
. The
default is
'off'.
4060 @item obsolete
=@
var{string
}
4061 Enable Obsolete system calls
4062 @item elevateprivileges
=@
var{string
}
4063 Disable set
*uid|gid system calls
4064 @item spawn
=@
var{string
}
4065 Disable
*fork and execve
4066 @item resourcecontrol
=@
var{string
}
4067 Disable process affinity and schedular priority
4071 DEF("readconfig", HAS_ARG
, QEMU_OPTION_readconfig
,
4072 "-readconfig <file>\n", QEMU_ARCH_ALL
)
4074 @item
-readconfig @
var{file
}
4076 Read device configuration from @
var{file
}. This approach is useful when you want to spawn
4077 QEMU process with many command line options but you don
't want to exceed the command line
4080 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
4081 "-writeconfig <file>\n"
4082 " read/write config file\n", QEMU_ARCH_ALL)
4084 @item -writeconfig @var{file}
4085 @findex -writeconfig
4086 Write device configuration to @var{file}. The @var{file} can be either filename to save
4087 command line and device configuration into file or dash @code{-}) character to print the
4088 output to stdout. This can be later used as input file for @code{-readconfig} option.
4090 HXCOMM Deprecated, same as -no-user-config
4091 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
4092 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
4094 " do not load default user-provided config files at startup\n",
4097 @item -no-user-config
4098 @findex -no-user-config
4099 The @code{-no-user-config} option makes QEMU not load any of the user-provided
4100 config files on @var{sysconfdir}.
4102 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
4103 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
4104 " specify tracing options\n",
4107 HXCOMM This line is not accurate, as some sub-options are backend-specific but
4108 HXCOMM HX does not support conditional compilation of text.
4109 @item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
4111 @include qemu-option-trace.texi
4115 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
4116 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
4119 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
4120 "-enable-fips enable FIPS 140-2 compliance\n",
4125 @findex -enable-fips
4126 Enable FIPS 140-2 compliance mode.
4129 HXCOMM Deprecated by -machine accel=tcg property
4130 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
4132 HXCOMM Deprecated by kvm-pit driver properties
4133 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
4136 HXCOMM Deprecated (ignored)
4137 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
4139 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
4140 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
4142 HXCOMM Deprecated (ignored)
4143 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
4145 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
4146 "-msg timestamp[=on|off]\n"
4147 " change the format of messages\n"
4148 " on|off controls leading timestamps (default:on)\n",
4151 @item -msg timestamp[=on|off]
4153 prepend a timestamp to each log message.(default:on)
4156 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
4157 "-dump-vmstate <file>\n"
4158 " Output vmstate information in JSON format to file.\n"
4159 " Use the scripts/vmstate-static-checker.py file to\n"
4160 " check for possible regressions in migration code\n"
4161 " by comparing two such vmstate dumps.\n",
4164 @item -dump-vmstate @var{file}
4165 @findex -dump-vmstate
4166 Dump json-encoded vmstate information for current machine type to file
4174 DEFHEADING(Generic object creation)
4179 DEF("object", HAS_ARG, QEMU_OPTION_object,
4180 "-object TYPENAME[,PROP1=VALUE1,...]\n"
4181 " create a new object of type TYPENAME setting properties\n"
4182 " in the order they are specified. Note that the 'id
'\n"
4183 " property must be set. These objects are placed in the\n"
4184 " '/objects
' path.\n",
4187 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
4189 Create a new object of type @var{typename} setting properties
4190 in the order they are specified. Note that the 'id
'
4191 property must be set. These objects are placed in the
4196 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off}
4198 Creates a memory file backend object, which can be used to back
4199 the guest RAM with huge pages. The @option{id} parameter is a
4200 unique ID that will be used to reference this memory region
4201 when configuring the @option{-numa} argument. The @option{size}
4202 option provides the size of the memory region, and accepts
4203 common suffixes, eg @option{500M}. The @option{mem-path} provides
4204 the path to either a shared memory or huge page filesystem mount.
4205 The @option{share} boolean option determines whether the memory
4206 region is marked as private to QEMU, or shared. The latter allows
4207 a co-operating external process to access the QEMU memory region.
4208 Setting the @option{discard-data} boolean option to @var{on}
4209 indicates that file contents can be destroyed when QEMU exits,
4210 to avoid unnecessarily flushing data to the backing file. Note
4211 that @option{discard-data} is only an optimization, and QEMU
4212 might not discard file contents if it aborts unexpectedly or is
4213 terminated using SIGKILL.
4215 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
4217 Creates a random number generator backend which obtains entropy from
4218 a device on the host. The @option{id} parameter is a unique ID that
4219 will be used to reference this entropy backend from the @option{virtio-rng}
4220 device. The @option{filename} parameter specifies which file to obtain
4221 entropy from and if omitted defaults to @option{/dev/random}.
4223 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4225 Creates a random number generator backend which obtains entropy from
4226 an external daemon running on the host. The @option{id} parameter is
4227 a unique ID that will be used to reference this entropy backend from
4228 the @option{virtio-rng} device. The @option{chardev} parameter is
4229 the unique ID of a character device backend that provides the connection
4232 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4234 Creates a TLS anonymous credentials object, which can be used to provide
4235 TLS support on network backends. The @option{id} parameter is a unique
4236 ID which network backends will use to access the credentials. The
4237 @option{endpoint} is either @option{server} or @option{client} depending
4238 on whether the QEMU network backend that uses the credentials will be
4239 acting as a client or as a server. If @option{verify-peer} is enabled
4240 (the default) then once the handshake is completed, the peer credentials
4241 will be verified, though this is a no-op for anonymous credentials.
4243 The @var{dir} parameter tells QEMU where to find the credential
4244 files. For server endpoints, this directory may contain a file
4245 @var{dh-params.pem} providing diffie-hellman parameters to use
4246 for the TLS server. If the file is missing, QEMU will generate
4247 a set of DH parameters at startup. This is a computationally
4248 expensive operation that consumes random pool entropy, so it is
4249 recommended that a persistent set of parameters be generated
4252 @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}
4254 Creates a TLS anonymous credentials object, which can be used to provide
4255 TLS support on network backends. The @option{id} parameter is a unique
4256 ID which network backends will use to access the credentials. The
4257 @option{endpoint} is either @option{server} or @option{client} depending
4258 on whether the QEMU network backend that uses the credentials will be
4259 acting as a client or as a server. If @option{verify-peer} is enabled
4260 (the default) then once the handshake is completed, the peer credentials
4261 will be verified. With x509 certificates, this implies that the clients
4262 must be provided with valid client certificates too.
4264 The @var{dir} parameter tells QEMU where to find the credential
4265 files. For server endpoints, this directory may contain a file
4266 @var{dh-params.pem} providing diffie-hellman parameters to use
4267 for the TLS server. If the file is missing, QEMU will generate
4268 a set of DH parameters at startup. This is a computationally
4269 expensive operation that consumes random pool entropy, so it is
4270 recommended that a persistent set of parameters be generated
4273 For x509 certificate credentials the directory will contain further files
4274 providing the x509 certificates. The certificates must be stored
4275 in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4276 @var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4277 @var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4279 For the @var{server-key.pem} and @var{client-key.pem} files which
4280 contain sensitive private keys, it is possible to use an encrypted
4281 version by providing the @var{passwordid} parameter. This provides
4282 the ID of a previously created @code{secret} object containing the
4283 password for decryption.
4285 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4287 Interval @var{t} can't be
0, this filter batches the packet delivery
: all
4288 packets arriving
in a given interval on netdev @
var{netdevid
} are delayed
4289 until the end of the interval
. Interval is
in microseconds
.
4290 @option
{status
} is optional that indicate whether the netfilter is
4291 on (enabled
) or
off (disabled
), the
default status
for netfilter will be
'on'.
4293 queue @
var{all|rx|tx
} is an option that can be applied to any netfilter
.
4295 @option
{all
}: the filter is attached both to the receive and the transmit
4296 queue of the
netdev (default).
4298 @option
{rx
}: the filter is attached to the receive queue of the netdev
,
4299 where it will receive packets sent to the netdev
.
4301 @option
{tx
}: the filter is attached to the transmit queue of the netdev
,
4302 where it will receive packets sent by the netdev
.
4304 @item
-object filter
-mirror
,id
=@
var{id
},netdev
=@
var{netdevid
},outdev
=@
var{chardevid
},queue
=@
var{all|rx|tx
}[,vnet_hdr_support
]
4306 filter
-mirror on netdev @
var{netdevid
},mirror net packet to chardev@
var{chardevid
}, if it has the vnet_hdr_support flag
, filter
-mirror will mirror packet with vnet_hdr_len
.
4308 @item
-object filter
-redirector
,id
=@
var{id
},netdev
=@
var{netdevid
},indev
=@
var{chardevid
},outdev
=@
var{chardevid
},queue
=@
var{all|rx|tx
}[,vnet_hdr_support
]
4310 filter
-redirector on netdev @
var{netdevid
},redirect filter
's net packet to chardev
4311 @var{chardevid},and redirect indev's packet to filter
.if it has the vnet_hdr_support flag
,
4312 filter
-redirector will redirect packet with vnet_hdr_len
.
4313 Create a filter
-redirector we need to differ outdev id from indev id
, id can not
4314 be the same
. we can just use indev or outdev
, but at least one of indev or outdev
4315 need to be specified
.
4317 @item
-object filter
-rewriter
,id
=@
var{id
},netdev
=@
var{netdevid
},queue
=@
var{all|rx|tx
},[vnet_hdr_support
]
4319 Filter
-rewriter is a part of COLO project
.It will rewrite tcp packet to
4320 secondary from primary to keep secondary tcp connection
,and rewrite
4321 tcp packet to primary from secondary make tcp packet can be handled by
4322 client
.if it has the vnet_hdr_support flag
, we can parse packet with vnet header
.
4326 -object filter
-redirector
,id
=f1
,netdev
=hn0
,queue
=tx
,indev
=red0
4327 -object filter
-redirector
,id
=f2
,netdev
=hn0
,queue
=rx
,outdev
=red1
4328 -object filter
-rewriter
,id
=rew0
,netdev
=hn0
,queue
=all
4330 @item
-object filter
-dump
,id
=@
var{id
},netdev
=@
var{dev
}[,file
=@
var{filename
}][,maxlen
=@
var{len
}]
4332 Dump the network traffic on netdev @
var{dev
} to the file specified by
4333 @
var{filename
}. At most @
var{len
} bytes (64k by
default) per packet are stored
.
4334 The file format is libpcap
, so it can be analyzed with tools such as tcpdump
4337 @item
-object colo
-compare
,id
=@
var{id
},primary_in
=@
var{chardevid
},secondary_in
=@
var{chardevid
},outdev
=@
var{chardevid
}[,vnet_hdr_support
]
4339 Colo
-compare gets packet from primary_in@
var{chardevid
} and secondary_in@
var{chardevid
}, than compare primary packet with
4340 secondary packet
. If the packets are same
, we will output primary
4341 packet to outdev@
var{chardevid
}, else we will notify colo
-frame
4342 do checkpoint and send primary packet to outdev@
var{chardevid
}.
4343 if it has the vnet_hdr_support flag
, colo compare will send
/recv packet with vnet_hdr_len
.
4345 we must use it with the help of filter
-mirror and filter
-redirector
.
4350 -netdev tap
,id
=hn0
,vhost
=off
,script
=/etc
/qemu
-ifup
,downscript
=/etc
/qemu
-ifdown
4351 -device e1000
,id
=e0
,netdev
=hn0
,mac
=52:a4
:00:12:78:66
4352 -chardev socket
,id
=mirror0
,host
=3.3.3.3,port
=9003,server
,nowait
4353 -chardev socket
,id
=compare1
,host
=3.3.3.3,port
=9004,server
,nowait
4354 -chardev socket
,id
=compare0
,host
=3.3.3.3,port
=9001,server
,nowait
4355 -chardev socket
,id
=compare0
-0,host
=3.3.3.3,port
=9001
4356 -chardev socket
,id
=compare_out
,host
=3.3.3.3,port
=9005,server
,nowait
4357 -chardev socket
,id
=compare_out0
,host
=3.3.3.3,port
=9005
4358 -object filter
-mirror
,id
=m0
,netdev
=hn0
,queue
=tx
,outdev
=mirror0
4359 -object filter
-redirector
,netdev
=hn0
,id
=redire0
,queue
=rx
,indev
=compare_out
4360 -object filter
-redirector
,netdev
=hn0
,id
=redire1
,queue
=rx
,outdev
=compare0
4361 -object colo
-compare
,id
=comp0
,primary_in
=compare0
-0,secondary_in
=compare1
,outdev
=compare_out0
4364 -netdev tap
,id
=hn0
,vhost
=off
,script
=/etc
/qemu
-ifup
,down script
=/etc
/qemu
-ifdown
4365 -device e1000
,netdev
=hn0
,mac
=52:a4
:00:12:78:66
4366 -chardev socket
,id
=red0
,host
=3.3.3.3,port
=9003
4367 -chardev socket
,id
=red1
,host
=3.3.3.3,port
=9004
4368 -object filter
-redirector
,id
=f1
,netdev
=hn0
,queue
=tx
,indev
=red0
4369 -object filter
-redirector
,id
=f2
,netdev
=hn0
,queue
=rx
,outdev
=red1
4373 If you want to know the detail of above command line
, you can read
4374 the colo
-compare git log
.
4376 @item
-object cryptodev
-backend
-builtin
,id
=@
var{id
}[,queues
=@
var{queues
}]
4378 Creates a cryptodev backend which executes crypto opreation from
4379 the QEMU cipher APIS
. The @
var{id
} parameter is
4380 a unique ID that will be used to reference
this cryptodev backend from
4381 the @option
{virtio
-crypto
} device
. The @
var{queues
} parameter is optional
,
4382 which specify the queue number of cryptodev backend
, the
default of
4387 # qemu
-system
-x86_64 \
4389 -object cryptodev
-backend
-builtin
,id
=cryptodev0 \
4390 -device virtio
-crypto
-pci
,id
=crypto0
,cryptodev
=cryptodev0 \
4394 @item
-object secret
,id
=@
var{id
},data
=@
var{string
},format
=@
var{raw|base64
}[,keyid
=@
var{secretid
},iv
=@
var{string
}]
4395 @item
-object secret
,id
=@
var{id
},file
=@
var{filename
},format
=@
var{raw|base64
}[,keyid
=@
var{secretid
},iv
=@
var{string
}]
4397 Defines a secret to store a password
, encryption key
, or some other sensitive
4398 data
. The sensitive data can either be passed directly via the @
var{data
}
4399 parameter
, or indirectly via the @
var{file
} parameter
. Using the @
var{data
}
4400 parameter is insecure unless the sensitive data is encrypted
.
4402 The sensitive data can be provided
in raw
format (the
default), or base64
.
4403 When encoded as JSON
, the raw format only supports valid UTF
-8 characters
,
4404 so base64 is recommended
for sending binary data
. QEMU will convert from
4405 which ever format is provided to the format it needs internally
. eg
, an
4406 RBD password can be provided
in raw format
, even though it will be base64
4407 encoded when passed onto the RBD sever
.
4409 For added protection
, it is possible to encrypt the data associated with
4410 a secret
using the AES
-256-CBC cipher
. Use of encryption is indicated
4411 by providing the @
var{keyid
} and @
var{iv
} parameters
. The @
var{keyid
}
4412 parameter provides the ID of a previously defined secret that contains
4413 the AES
-256 decryption key
. This key should be
32-bytes long and be
4414 base64 encoded
. The @
var{iv
} parameter provides the random initialization
4415 vector used
for encryption of
this particular secret and should be a
4416 base64 encrypted string of the
16-byte IV
.
4418 The
simplest (insecure
) usage is to provide the secret
inline
4422 # $QEMU
-object secret
,id
=sec0
,data
=letmein
,format
=raw
4426 The simplest secure usage is to provide the secret via a file
4428 # printf
"letmein" > mypasswd
.txt
4429 # $QEMU
-object secret
,id
=sec0
,file
=mypasswd
.txt
,format
=raw
4431 For greater security
, AES
-256-CBC should be used
. To illustrate usage
,
4432 consider the openssl command line tool which can encrypt the data
. Note
4433 that when encrypting
, the plaintext must be padded to the cipher block
4434 size (32 bytes
) using the standard PKCS#
5/6 compatible padding algorithm
.
4436 First a master key needs to be created
in base64 encoding
:
4439 # openssl rand
-base64
32 > key
.b64
4440 # KEY
=$
(base64
-d key
.b64 | hexdump
-v
-e
'/1 "%02X"')
4443 Each secret to be encrypted needs to have a random initialization vector
4444 generated
. These
do not need to be kept secret
4447 # openssl rand
-base64
16 > iv
.b64
4448 # IV
=$
(base64
-d iv
.b64 | hexdump
-v
-e
'/1 "%02X"')
4451 The secret to be defined can now be encrypted
, in this case we
're
4452 telling openssl to base64 encode the result, but it could be left
4453 as raw bytes if desired.
4456 # SECRET=$(printf "letmein" |
4457 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4460 When launching QEMU, create a master secret pointing to @code{key.b64}
4461 and specify that to be used to decrypt the user password. Pass the
4462 contents of @code{iv.b64} to the second secret
4466 -object secret,id=secmaster0,format=base64,file=key.b64 \
4467 -object secret,id=sec0,keyid=secmaster0,format=base64,\
4468 data=$SECRET,iv=$(<iv.b64)
4476 HXCOMM This is the last statement. Insert new options before this line!