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, hvf, whpx 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 " memory-encryption=@var{} memory encryption object to use (default=none)\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
, hvf
, whpx 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 enforce
-config
-section
=on|off
99 If @option
{enforce
-config
-section
} is set to @
var{on
}, force migration
100 code to send configuration section even
if the machine
-type sets the
101 @option
{migration
.send
-configuration
} property to @
var{off
}.
102 NOTE
: this parameter is deprecated
. Please use @option
{-global
}
103 @option
{migration
.send
-configuration
}=@
var{on|off
} instead
.
104 @item memory
-encryption
=@
var{}
105 Memory encryption object to use
. The
default is none
.
109 HXCOMM Deprecated by
-machine
110 DEF("M", HAS_ARG
, QEMU_OPTION_M
, "", QEMU_ARCH_ALL
)
112 DEF("cpu", HAS_ARG
, QEMU_OPTION_cpu
,
113 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL
)
115 @item
-cpu @
var{model
}
117 Select CPU
model (@code
{-cpu help
} for list and additional feature selection
)
120 DEF("accel", HAS_ARG
, QEMU_OPTION_accel
,
121 "-accel [accel=]accelerator[,thread=single|multi]\n"
122 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n"
123 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL
)
125 @item
-accel @
var{name
}[,prop
=@
var{value
}[,...]]
127 This is used to enable an accelerator
. Depending on the target architecture
,
128 kvm
, xen
, hax
, hvf
, whpx or tcg can be available
. By
default, tcg is used
. If there is
129 more than one accelerator specified
, the next one is used
if the previous one
132 @item thread
=single|multi
133 Controls number of TCG threads
. When the TCG is multi
-threaded there will be one
134 thread per vCPU therefor taking advantage of additional host cores
. The
default
135 is to enable multi
-threading where both the back
-end and front
-ends support it and
136 no incompatible TCG features have been
enabled (e
.g
. icount
/replay
).
140 DEF("smp", HAS_ARG
, QEMU_OPTION_smp
,
141 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
142 " set the number of CPUs to 'n' [default=1]\n"
143 " maxcpus= maximum number of total cpus, including\n"
144 " offline CPUs for hotplug, etc\n"
145 " cores= number of CPU cores on one socket\n"
146 " threads= number of threads on one CPU core\n"
147 " sockets= number of discrete sockets in the system\n",
150 @item
-smp
[cpus
=]@
var{n
}[,cores
=@
var{cores
}][,threads
=@
var{threads
}][,sockets
=@
var{sockets
}][,maxcpus
=@
var{maxcpus
}]
152 Simulate an SMP system with @
var{n
} CPUs
. On the PC target
, up to
255
153 CPUs are supported
. On Sparc32 target
, Linux limits the number of usable CPUs
155 For the PC target
, the number of @
var{cores
} per socket
, the number
156 of @
var{threads
} per cores and the total number of @
var{sockets
} can be
157 specified
. Missing values will be computed
. If any on the three values is
158 given
, the total number of CPUs @
var{n
} can be omitted
. @
var{maxcpus
}
159 specifies the maximum number of hotpluggable CPUs
.
162 DEF("numa", HAS_ARG
, QEMU_OPTION_numa
,
163 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
164 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
165 "-numa dist,src=source,dst=destination,val=distance\n"
166 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n",
169 @item
-numa node
[,mem
=@
var{size
}][,cpus
=@
var{firstcpu
}[-@
var{lastcpu
}]][,nodeid
=@
var{node
}]
170 @itemx
-numa node
[,memdev
=@
var{id
}][,cpus
=@
var{firstcpu
}[-@
var{lastcpu
}]][,nodeid
=@
var{node
}]
171 @itemx
-numa dist
,src
=@
var{source
},dst
=@
var{destination
},val
=@
var{distance
}
172 @itemx
-numa cpu
,node
-id
=@
var{node
}[,socket
-id
=@
var{x
}][,core
-id
=@
var{y
}][,thread
-id
=@
var{z
}]
174 Define a NUMA node and assign RAM and VCPUs to it
.
175 Set the NUMA distance from a source node to a destination node
.
177 Legacy VCPU assignment uses @samp
{cpus
} option where
178 @
var{firstcpu
} and @
var{lastcpu
} are CPU indexes
. Each
179 @samp
{cpus
} option represent a contiguous range of CPU indexes
180 (or a single VCPU
if @
var{lastcpu
} is omitted
). A non
-contiguous
181 set of VCPUs can be represented by providing multiple @samp
{cpus
}
182 options
. If @samp
{cpus
} is omitted on all nodes
, VCPUs are automatically
185 For example
, the following option assigns VCPUs
0, 1, 2 and
5 to
188 -numa node
,cpus
=0-2,cpus
=5
191 @samp
{cpu
} option is a
new alternative to @samp
{cpus
} option
192 which uses @samp
{socket
-id|core
-id|thread
-id
} properties to assign
193 CPU objects to a @
var{node
} using topology layout properties of CPU
.
194 The set of properties is machine specific
, and depends on used
195 machine type
/@samp
{smp
} options
. It could be queried with
196 @samp
{hotpluggable
-cpus
} monitor command
.
197 @samp
{node
-id
} property specifies @
var{node
} to which CPU object
198 will be assigned
, it
's required for @var{node} to be declared
199 with @samp{node} option before it's used with @samp
{cpu
} option
.
204 -smp
1,sockets
=2,maxcpus
=2 \
205 -numa node
,nodeid
=0 -numa node
,nodeid
=1 \
206 -numa cpu
,node
-id
=0,socket
-id
=0 -numa cpu
,node
-id
=1,socket
-id
=1
209 @samp
{mem
} assigns a given RAM amount to a node
. @samp
{memdev
}
210 assigns RAM from a given memory backend device to a node
. If
211 @samp
{mem
} and @samp
{memdev
} are omitted
in all nodes
, RAM is
212 split equally between them
.
214 @samp
{mem
} and @samp
{memdev
} are mutually exclusive
. Furthermore
,
215 if one node uses @samp
{memdev
}, all of them have to use it
.
217 @
var{source
} and @
var{destination
} are NUMA node IDs
.
218 @
var{distance
} is the NUMA distance from @
var{source
} to @
var{destination
}.
219 The distance from a node to itself is always
10. If any pair of nodes is
220 given a distance
, then all pairs must be given distances
. Although
, when
221 distances are only given
in one direction
for each pair of nodes
, then
222 the distances
in the opposite directions are assumed to be the same
. If
,
223 however
, an asymmetrical pair of distances is given
for even one node
224 pair
, then all node pairs must be provided distance values
for both
225 directions
, even when they are symmetrical
. When a node is unreachable
226 from another node
, set the pair
's distance to 255.
228 Note that the -@option{numa} option doesn't allocate any of the
229 specified resources
, it just assigns existing resources to NUMA
230 nodes
. This means that one still has to use the @option
{-m
},
231 @option
{-smp
} options to allocate RAM and VCPUs respectively
.
235 DEF("add-fd", HAS_ARG
, QEMU_OPTION_add_fd
,
236 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
237 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL
)
239 @item
-add
-fd fd
=@
var{fd
},set
=@
var{set
}[,opaque
=@
var{opaque
}]
242 Add a file descriptor to an fd set
. Valid options are
:
246 This option defines the file descriptor of which a duplicate is added to fd set
.
247 The file descriptor cannot be stdin
, stdout
, or stderr
.
249 This option defines the ID of the fd set to add the file descriptor to
.
250 @item opaque
=@
var{opaque
}
251 This option defines a free
-form string that can be used to describe @
var{fd
}.
254 You can open an image
using pre
-opened file descriptors from an fd set
:
257 -add
-fd fd
=3,set
=2,opaque
="rdwr:/path/to/file"
258 -add
-fd fd
=4,set
=2,opaque
="rdonly:/path/to/file"
259 -drive file
=/dev
/fdset
/2,index
=0,media
=disk
263 DEF("set", HAS_ARG
, QEMU_OPTION_set
,
264 "-set group.id.arg=value\n"
265 " set <arg> parameter for item <id> of type <group>\n"
266 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL
)
268 @item
-set @
var{group
}.@
var{id
}.@
var{arg
}=@
var{value
}
270 Set parameter @
var{arg
} for item @
var{id
} of type @
var{group
}
273 DEF("global", HAS_ARG
, QEMU_OPTION_global
,
274 "-global driver.property=value\n"
275 "-global driver=driver,property=property,value=value\n"
276 " set a global default for a driver property\n",
279 @item
-global @
var{driver
}.@
var{prop
}=@
var{value
}
280 @itemx
-global driver
=@
var{driver
},property
=@
var{property
},value
=@
var{value
}
282 Set
default value of @
var{driver
}'s property @var{prop} to @var{value}, e.g.:
285 qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
288 In particular, you can use this to set driver properties for devices which are
289 created automatically by the machine model. To create a device which is not
290 created automatically and set properties on it, use -@option{device}.
292 -global @var{driver}.@var{prop}=@var{value} is shorthand for -global
293 driver=@var{driver},property=@var{prop},value=@var{value}. The
294 longhand syntax works even when @var{driver} contains a dot.
297 DEF("boot", HAS_ARG, QEMU_OPTION_boot,
298 "-boot [order=drives][,once=drives][,menu=on|off]\n"
299 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
300 " 'drives
': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
301 " 'sp_name
': the file's name that would be passed to bios as logo picture
, if menu
=on
\n"
302 " 'sp_time': the period that splash picture last
if menu
=on
, unit is ms
\n"
303 " 'rb_timeout': the timeout before guest reboot when boot failed
, unit is ms
\n",
306 @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]
308 Specify boot order @var{drives} as a string of drive letters. Valid
309 drive letters depend on the target architecture. The x86 PC uses: a, b
310 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
311 from network adapter 1-4), hard disk boot is the default. To apply a
312 particular boot order only on the first startup, specify it via
313 @option{once}. Note that the @option{order} or @option{once} parameter
314 should not be used together with the @option{bootindex} property of
315 devices, since the firmware implementations normally do not support both
318 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
319 as firmware/BIOS supports them. The default is non-interactive boot.
321 A splash picture could be passed to bios, enabling user to show it as logo,
322 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
323 supports them. Currently Seabios for X86 system support it.
324 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
325 format(true color). The resolution should be supported by the SVGA mode, so
326 the recommended is 320x240, 640x480, 800x640.
328 A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
329 when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
330 reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
333 Do strict boot via @option{strict=on} as far as firmware/BIOS
334 supports it. This only effects when boot priority is changed by
335 bootindex options. The default is non-strict boot.
338 # try to boot from network first, then from hard disk
339 qemu-system-i386 -boot order=nc
340 # boot from CD-ROM first, switch back to default order after reboot
341 qemu-system-i386 -boot once=d
342 # boot with a splash picture for 5 seconds.
343 qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
346 Note: The legacy format '-boot @var{drives}' is still supported but its
347 use is discouraged as it may be removed from future versions.
350 DEF("m
", HAS_ARG, QEMU_OPTION_m,
351 "-m
[size
=]megs
[,slots
=n
,maxmem
=size
]\n"
352 " configure guest RAM
\n"
353 " size
: initial amount of guest memory
\n"
354 " slots
: number of hotplug
slots (default: none
)\n"
355 " maxmem
: maximum amount of guest
memory (default: none
)\n"
356 "NOTE
: Some architectures might enforce a specific granularity
\n",
359 @item -m [size=]@var{megs}[,slots=n,maxmem=size]
361 Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
362 Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
363 megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
364 could be used to set amount of hotpluggable memory slots and maximum amount of
365 memory. Note that @var{maxmem} must be aligned to the page size.
367 For example, the following command-line sets the guest startup RAM size to
368 1GB, creates 3 slots to hotplug additional memory and sets the maximum
369 memory the guest can reach to 4GB:
372 qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
375 If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
376 be enabled and the guest startup RAM will never increase.
379 DEF("mem
-path
", HAS_ARG, QEMU_OPTION_mempath,
380 "-mem
-path FILE provide backing storage
for guest RAM
\n", QEMU_ARCH_ALL)
382 @item -mem-path @var{path}
384 Allocate guest RAM from a temporarily created file in @var{path}.
387 DEF("mem
-prealloc
", 0, QEMU_OPTION_mem_prealloc,
388 "-mem
-prealloc preallocate guest
memory (use with
-mem
-path
)\n",
392 @findex -mem-prealloc
393 Preallocate memory when using -mem-path.
396 DEF("k
", HAS_ARG, QEMU_OPTION_k,
397 "-k language use keyboard
layout (for example
'fr' for French
)\n",
400 @item -k @var{language}
402 Use keyboard layout @var{language} (for example @code{fr} for
403 French). This option is only needed where it is not easy to get raw PC
404 keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
405 display). You don't normally need to use it on PC/Linux or PC/Windows
408 The available layouts are:
410 ar de-ch es fo fr-ca hu ja mk no pt-br sv
411 da en-gb et fr fr-ch is lt nl pl ru th
412 de en-us fi fr-be hr it lv nl-be pt sl tr
415 The default is @code{en-us}.
419 DEF("audio
-help
", 0, QEMU_OPTION_audio_help,
420 "-audio
-help print list of audio drivers and their options
\n",
425 Will show the audio subsystem help: list of drivers, tunable
429 DEF("soundhw
", HAS_ARG, QEMU_OPTION_soundhw,
430 "-soundhw c1
,... enable audio support
\n"
431 " and only specified sound
cards (comma separated list
)\n"
432 " use
'-soundhw help' to get the list of supported cards
\n"
433 " use
'-soundhw all' to enable all of them
\n", QEMU_ARCH_ALL)
435 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
437 Enable audio and selected sound hardware. Use 'help' to print all
438 available sound hardware.
441 qemu-system-i386 -soundhw sb16,adlib disk.img
442 qemu-system-i386 -soundhw es1370 disk.img
443 qemu-system-i386 -soundhw ac97 disk.img
444 qemu-system-i386 -soundhw hda disk.img
445 qemu-system-i386 -soundhw all disk.img
446 qemu-system-i386 -soundhw help
449 Note that Linux's i810_audio OSS kernel (for AC97) module might
450 require manually specifying clocking.
453 modprobe i810_audio clocking=48000
457 DEF("device
", HAS_ARG, QEMU_OPTION_device,
458 "-device driver
[,prop
[=value
][,...]]\n"
459 " add
device (based on driver
)\n"
460 " prop
=value
,... sets driver properties
\n"
461 " use
'-device help' to print all possible drivers
\n"
462 " use
'-device driver,help' to print all possible properties
\n",
465 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
467 Add device @var{driver}. @var{prop}=@var{value} sets driver
468 properties. Valid properties depend on the driver. To get help on
469 possible drivers and properties, use @code{-device help} and
470 @code{-device @var{driver},help}.
473 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
475 Add an IPMI BMC. This is a simulation of a hardware management
476 interface processor that normally sits on a system. It provides
477 a watchdog and the ability to reset and power control the system.
478 You need to connect this to an IPMI interface to make it useful
480 The IPMI slave address to use for the BMC. The default is 0x20.
481 This address is the BMC's address on the I2C network of management
482 controllers. If you don't know what this means, it is safe to ignore
487 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
488 @item slave_addr=@var{val}
489 Define slave address to use for the BMC. The default is 0x20.
490 @item sdrfile=@var{file}
491 file containing raw Sensor Data Records (SDR) data. The default is none.
492 @item fruareasize=@var{val}
493 size of a Field Replaceable Unit (FRU) area. The default is 1024.
494 @item frudatafile=@var{file}
495 file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
498 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
500 Add a connection to an external IPMI BMC simulator. Instead of
501 locally emulating the BMC like the above item, instead connect
502 to an external entity that provides the IPMI services.
504 A connection is made to an external BMC simulator. If you do this, it
505 is strongly recommended that you use the "reconnect
=" chardev option
506 to reconnect to the simulator if the connection is lost. Note that if
507 this is not used carefully, it can be a security issue, as the
508 interface has the ability to send resets, NMIs, and power off the VM.
509 It's best if QEMU makes a connection to an external simulator running
510 on a secure port on localhost, so neither the simulator nor QEMU is
511 exposed to any outside network.
513 See the "lanserv
/README
.vm
" file in the OpenIPMI library for more
514 details on the external interface.
516 @item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
518 Add a KCS IPMI interafce on the ISA bus. This also adds a
519 corresponding ACPI and SMBIOS entries, if appropriate.
523 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
524 @item ioport=@var{val}
525 Define the I/O address of the interface. The default is 0xca0 for KCS.
527 Define the interrupt to use. The default is 5. To disable interrupts,
531 @item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
533 Like the KCS interface, but defines a BT interface. The default port is
534 0xe4 and the default interrupt is 5.
538 DEF("name
", HAS_ARG, QEMU_OPTION_name,
539 "-name string1
[,process
=string2
][,debug
-threads
=on|off
]\n"
540 " set the name of the guest
\n"
541 " string1 sets the window title and string2 the process name
\n"
542 " When debug
-threads is enabled
, individual threads are given a separate name
\n"
543 " NOTE
: The thread names are
for debugging and not a stable API
.\n",
546 @item -name @var{name}
548 Sets the @var{name} of the guest.
549 This name will be displayed in the SDL window caption.
550 The @var{name} will also be used for the VNC server.
551 Also optionally set the top visible process name in Linux.
552 Naming of individual threads can also be enabled on Linux to aid debugging.
555 DEF("uuid
", HAS_ARG, QEMU_OPTION_uuid,
556 "-uuid
%08x
-%04x
-%04x
-%04x
-%012x
\n"
557 " specify machine UUID
\n", QEMU_ARCH_ALL)
559 @item -uuid @var{uuid}
569 DEFHEADING(Block device options:)
574 DEF("fda
", HAS_ARG, QEMU_OPTION_fda,
575 "-fda
/-fdb file use
'file' as floppy disk
0/1 image
\n", QEMU_ARCH_ALL)
576 DEF("fdb
", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
578 @item -fda @var{file}
579 @itemx -fdb @var{file}
582 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
585 DEF("hda
", HAS_ARG, QEMU_OPTION_hda,
586 "-hda
/-hdb file use
'file' as IDE hard disk
0/1 image
\n", QEMU_ARCH_ALL)
587 DEF("hdb
", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
588 DEF("hdc
", HAS_ARG, QEMU_OPTION_hdc,
589 "-hdc
/-hdd file use
'file' as IDE hard disk
2/3 image
\n", QEMU_ARCH_ALL)
590 DEF("hdd
", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
592 @item -hda @var{file}
593 @itemx -hdb @var{file}
594 @itemx -hdc @var{file}
595 @itemx -hdd @var{file}
600 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
603 DEF("cdrom
", HAS_ARG, QEMU_OPTION_cdrom,
604 "-cdrom file use
'file' as IDE cdrom
image (cdrom is ide1 master
)\n",
607 @item -cdrom @var{file}
609 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
610 @option{-cdrom} at the same time). You can use the host CD-ROM by
611 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
614 DEF("blockdev
", HAS_ARG, QEMU_OPTION_blockdev,
615 "-blockdev
[driver
=]driver
[,node
-name
=N
][,discard
=ignore|unmap
]\n"
616 " [,cache
.direct
=on|off
][,cache
.no
-flush
=on|off
]\n"
617 " [,read
-only
=on|off
][,detect
-zeroes
=on|off|unmap
]\n"
618 " [,driver specific parameters
...]\n"
619 " configure a block backend
\n", QEMU_ARCH_ALL)
621 @item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
624 Define a new block driver node. Some of the options apply to all block drivers,
625 other options are only accepted for a specific block driver. See below for a
626 list of generic options and options for the most common block drivers.
628 Options that expect a reference to another node (e.g. @code{file}) can be
629 given in two ways. Either you specify the node name of an already existing node
630 (file=@var{node-name}), or you define a new node inline, adding options
631 for the referenced node after a dot (file.filename=@var{path},file.aio=native).
633 A block driver node created with @option{-blockdev} can be used for a guest
634 device by specifying its node name for the @code{drive} property in a
635 @option{-device} argument that defines a block device.
638 @item Valid options for any block driver node:
642 Specifies the block driver to use for the given node.
644 This defines the name of the block driver node by which it will be referenced
645 later. The name must be unique, i.e. it must not match the name of a different
646 block driver node, or (if you use @option{-drive} as well) the ID of a drive.
648 If no node name is specified, it is automatically generated. The generated node
649 name is not intended to be predictable and changes between QEMU invocations.
650 For the top level, an explicit node name must be specified.
652 Open the node read-only. Guest write attempts will fail.
654 The host page cache can be avoided with @option{cache.direct=on}. This will
655 attempt to do disk IO directly to the guest's memory. QEMU may still perform an
656 internal copy of the data.
658 In case you don't care about data integrity over host failures, you can use
659 @option{cache.no-flush=on}. This option tells QEMU that it never needs to write
660 any data to the disk but can instead keep things in cache. If anything goes
661 wrong, like your host losing power, the disk storage getting disconnected
662 accidentally, etc. your image will most probably be rendered unusable.
663 @item discard=@var{discard}
664 @var{discard} is one of "ignore
" (or "off
") or "unmap
" (or "on
") and controls
665 whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
666 ignored or passed to the filesystem. Some machine types may not support
668 @item detect-zeroes=@var{detect-zeroes}
669 @var{detect-zeroes} is "off
", "on
" or "unmap
" and enables the automatic
670 conversion of plain zero writes by the OS to driver specific optimized
671 zero write commands. You may even choose "unmap
" if @var{discard} is set
672 to "unmap
" to allow a zero write to be converted to an @code{unmap} operation.
675 @item Driver-specific options for @code{file}
677 This is the protocol-level block driver for accessing regular files.
681 The path to the image file in the local filesystem
683 Specifies the AIO backend (threads/native, default: threads)
685 Specifies whether the image file is protected with Linux OFD / POSIX locks. The
686 default is to use the Linux Open File Descriptor API if available, otherwise no
687 lock is applied. (auto/on/off, default: auto)
691 -blockdev driver=file,node-name=disk,filename=disk.img
694 @item Driver-specific options for @code{raw}
696 This is the image format block driver for raw images. It is usually
697 stacked on top of a protocol level block driver such as @code{file}.
701 Reference to or definition of the data source block driver node
702 (e.g. a @code{file} driver node)
706 -blockdev driver=file,node-name=disk_file,filename=disk.img
707 -blockdev driver=raw,node-name=disk,file=disk_file
711 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
714 @item Driver-specific options for @code{qcow2}
716 This is the image format block driver for qcow2 images. It is usually
717 stacked on top of a protocol level block driver such as @code{file}.
721 Reference to or definition of the data source block driver node
722 (e.g. a @code{file} driver node)
725 Reference to or definition of the backing file block device (default is taken
726 from the image file). It is allowed to pass @code{null} here in order to disable
727 the default backing file.
730 Whether to enable the lazy refcounts feature (on/off; default is taken from the
734 The maximum total size of the L2 table and refcount block caches in bytes
735 (default: the sum of l2-cache-size and refcount-cache-size)
738 The maximum size of the L2 table cache in bytes
739 (default: if cache-size is not specified - 32M on Linux platforms, and 8M on
740 non-Linux platforms; otherwise, as large as possible within the cache-size,
741 while permitting the requested or the minimal refcount cache size)
743 @item refcount-cache-size
744 The maximum size of the refcount block cache in bytes
745 (default: 4 times the cluster size; or if cache-size is specified, the part of
746 it which is not used for the L2 cache)
748 @item cache-clean-interval
749 Clean unused entries in the L2 and refcount caches. The interval is in seconds.
750 The default value is 600 on supporting platforms, and 0 on other platforms.
751 Setting it to 0 disables this feature.
753 @item pass-discard-request
754 Whether discard requests to the qcow2 device should be forwarded to the data
755 source (on/off; default: on if discard=unmap is specified, off otherwise)
757 @item pass-discard-snapshot
758 Whether discard requests for the data source should be issued when a snapshot
759 operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
762 @item pass-discard-other
763 Whether discard requests for the data source should be issued on other
764 occasions where a cluster gets freed (on/off; default: off)
767 Which overlap checks to perform for writes to the image
768 (none/constant/cached/all; default: cached). For details or finer
769 granularity control refer to the QAPI documentation of @code{blockdev-add}.
774 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
775 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
779 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
782 @item Driver-specific options for other drivers
783 Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
789 DEF("drive
", HAS_ARG, QEMU_OPTION_drive,
790 "-drive
[file
=file
][,if=type
][,bus
=n
][,unit
=m
][,media
=d
][,index
=i
]\n"
791 " [,cache
=writethrough|writeback|none|directsync|unsafe
][,format
=f
]\n"
792 " [,snapshot
=on|off
][,rerror
=ignore|stop|report
]\n"
793 " [,werror
=ignore|stop|report|enospc
][,id
=name
][,aio
=threads|native
]\n"
794 " [,readonly
=on|off
][,copy
-on
-read
=on|off
]\n"
795 " [,discard
=ignore|unmap
][,detect
-zeroes
=on|off|unmap
]\n"
796 " [[,bps
=b
]|
[[,bps_rd
=r
][,bps_wr
=w
]]]\n"
797 " [[,iops
=i
]|
[[,iops_rd
=r
][,iops_wr
=w
]]]\n"
798 " [[,bps_max
=bm
]|
[[,bps_rd_max
=rm
][,bps_wr_max
=wm
]]]\n"
799 " [[,iops_max
=im
]|
[[,iops_rd_max
=irm
][,iops_wr_max
=iwm
]]]\n"
800 " [[,iops_size
=is
]]\n"
802 " use
'file' as a drive image
\n", QEMU_ARCH_ALL)
804 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
807 Define a new drive. This includes creating a block driver node (the backend) as
808 well as a guest device, and is mostly a shortcut for defining the corresponding
809 @option{-blockdev} and @option{-device} options.
811 @option{-drive} accepts all options that are accepted by @option{-blockdev}. In
812 addition, it knows the following options:
815 @item file=@var{file}
816 This option defines which disk image (@pxref{disk_images}) to use with
817 this drive. If the filename contains comma, you must double it
818 (for instance, "file
=my
,,file
" to use file "my
,file
").
820 Special files such as iSCSI devices can be specified using protocol
821 specific URLs. See the section for "Device URL Syntax
" for more information.
822 @item if=@var{interface}
823 This option defines on which type on interface the drive is connected.
824 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
825 @item bus=@var{bus},unit=@var{unit}
826 These options define where is connected the drive by defining the bus number and
828 @item index=@var{index}
829 This option defines where is connected the drive by using an index in the list
830 of available connectors of a given interface type.
831 @item media=@var{media}
832 This option defines the type of the media: disk or cdrom.
833 @item snapshot=@var{snapshot}
834 @var{snapshot} is "on
" or "off
" and controls snapshot mode for the given drive
835 (see @option{-snapshot}).
836 @item cache=@var{cache}
837 @var{cache} is "none
", "writeback
", "unsafe
", "directsync
" or "writethrough
"
838 and controls how the host cache is used to access block data. This is a
839 shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
840 options (as in @option{-blockdev}), and additionally @option{cache.writeback},
841 which provides a default for the @option{write-cache} option of block guest
842 devices (as in @option{-device}). The modes correspond to the following
845 @c Our texi2pod.pl script doesn't support @multitable, so fall back to using
846 @c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
847 @c and the HTML output.
849 @ │ cache.writeback cache.direct cache.no-flush
850 ─────────────┼─────────────────────────────────────────────────
851 writeback │ on off off
853 writethrough │ off off off
854 directsync │ off on off
858 The default mode is @option{cache=writeback}.
861 @var{aio} is "threads
", or "native
" and selects between pthread based disk I/O and native Linux AIO.
862 @item format=@var{format}
863 Specify which disk @var{format} will be used rather than detecting
864 the format. Can be used to specify format=raw to avoid interpreting
865 an untrusted format header.
866 @item werror=@var{action},rerror=@var{action}
867 Specify which @var{action} to take on write and read errors. Valid actions are:
868 "ignore
" (ignore the error and try to continue), "stop
" (pause QEMU),
869 "report
" (report the error to the guest), "enospc
" (pause QEMU only if the
870 host disk is full; report the error to the guest otherwise).
871 The default setting is @option{werror=enospc} and @option{rerror=report}.
872 @item copy-on-read=@var{copy-on-read}
873 @var{copy-on-read} is "on
" or "off
" and enables whether to copy read backing
874 file sectors into the image file.
875 @item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
876 Specify bandwidth throttling limits in bytes per second, either for all request
877 types or for reads or writes only. Small values can lead to timeouts or hangs
878 inside the guest. A safe minimum for disks is 2 MB/s.
879 @item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
880 Specify bursts in bytes per second, either for all request types or for reads
881 or writes only. Bursts allow the guest I/O to spike above the limit
883 @item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
884 Specify request rate limits in requests per second, either for all request
885 types or for reads or writes only.
886 @item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
887 Specify bursts in requests per second, either for all request types or for reads
888 or writes only. Bursts allow the guest I/O to spike above the limit
890 @item iops_size=@var{is}
891 Let every @var{is} bytes of a request count as a new request for iops
892 throttling purposes. Use this option to prevent guests from circumventing iops
893 limits by sending fewer but larger requests.
895 Join a throttling quota group with given name @var{g}. All drives that are
896 members of the same group are accounted for together. Use this option to
897 prevent guests from circumventing throttling limits by using many small disks
898 instead of a single larger disk.
901 By default, the @option{cache.writeback=on} mode is used. It will report data
902 writes as completed as soon as the data is present in the host page cache.
903 This is safe as long as your guest OS makes sure to correctly flush disk caches
904 where needed. If your guest OS does not handle volatile disk write caches
905 correctly and your host crashes or loses power, then the guest may experience
908 For such guests, you should consider using @option{cache.writeback=off}. This
909 means that the host page cache will be used to read and write data, but write
910 notification will be sent to the guest only after QEMU has made sure to flush
911 each write to the disk. Be aware that this has a major impact on performance.
913 When using the @option{-snapshot} option, unsafe caching is always used.
915 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
916 useful when the backing file is over a slow network. By default copy-on-read
919 Instead of @option{-cdrom} you can use:
921 qemu-system-i386 -drive file=file,index=2,media=cdrom
924 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
927 qemu-system-i386 -drive file=file,index=0,media=disk
928 qemu-system-i386 -drive file=file,index=1,media=disk
929 qemu-system-i386 -drive file=file,index=2,media=disk
930 qemu-system-i386 -drive file=file,index=3,media=disk
933 You can open an image using pre-opened file descriptors from an fd set:
936 -add-fd fd=3,set=2,opaque="rdwr
:/path
/to
/file
"
937 -add-fd fd=4,set=2,opaque="rdonly
:/path
/to
/file
"
938 -drive file=/dev/fdset/2,index=0,media=disk
941 You can connect a CDROM to the slave of ide0:
943 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
946 If you don't specify the "file
=" argument, you define an empty drive:
948 qemu-system-i386 -drive if=ide,index=1,media=cdrom
951 Instead of @option{-fda}, @option{-fdb}, you can use:
953 qemu-system-i386 -drive file=file,index=0,if=floppy
954 qemu-system-i386 -drive file=file,index=1,if=floppy
957 By default, @var{interface} is "ide
" and @var{index} is automatically
960 qemu-system-i386 -drive file=a -drive file=b"
964 qemu
-system
-i386
-hda a
-hdb b
968 DEF("mtdblock", HAS_ARG
, QEMU_OPTION_mtdblock
,
969 "-mtdblock file use 'file' as on-board Flash memory image\n",
972 @item
-mtdblock @
var{file
}
974 Use @
var{file
} as on
-board Flash memory image
.
977 DEF("sd", HAS_ARG
, QEMU_OPTION_sd
,
978 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL
)
982 Use @
var{file
} as SecureDigital card image
.
985 DEF("pflash", HAS_ARG
, QEMU_OPTION_pflash
,
986 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL
)
988 @item
-pflash @
var{file
}
990 Use @
var{file
} as a parallel flash image
.
993 DEF("snapshot", 0, QEMU_OPTION_snapshot
,
994 "-snapshot write to temporary files instead of disk image files\n",
999 Write to temporary files instead of disk image files
. In
this case,
1000 the raw disk image you use is not written back
. You can however force
1001 the write back by pressing @key
{C
-a s
} (@pxref
{disk_images
}).
1004 DEF("fsdev", HAS_ARG
, QEMU_OPTION_fsdev
,
1005 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1006 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1007 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1008 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1009 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1010 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1011 " [[,throttling.iops-size=is]]\n",
1016 @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
}]
1018 Define a
new file system device
. Valid options are
:
1020 @item @
var{fsdriver
}
1021 This option specifies the fs driver backend to use
.
1022 Currently
"local" and
"proxy" file system drivers are supported
.
1024 Specifies identifier
for this device
1025 @item path
=@
var{path
}
1026 Specifies the export path
for the file system device
. Files under
1027 this path will be available to the
9p client on the guest
.
1028 @item security_model
=@
var{security_model
}
1029 Specifies the security model to be used
for this export path
.
1030 Supported security models are
"passthrough", "mapped-xattr", "mapped-file" and
"none".
1031 In
"passthrough" security model
, files are stored
using the same
1032 credentials as they are created on the guest
. This requires QEMU
1033 to run as root
. In
"mapped-xattr" security model
, some of the file
1034 attributes like uid
, gid
, mode bits and link target are stored as
1035 file attributes
. For
"mapped-file" these attributes are stored
in the
1036 hidden
.virtfs_metadata directory
. Directories exported by
this security model cannot
1037 interact with other unix tools
. "none" security model is same as
1038 passthrough except the sever won
't report failures if it fails to
1039 set file attributes like ownership. Security model is mandatory
1040 only for local fsdriver. Other fsdrivers (like proxy) don't take
1041 security model as a parameter
.
1042 @item writeout
=@
var{writeout
}
1043 This is an optional argument
. The only supported value is
"immediate".
1044 This means that host page cache will be used to read and write data but
1045 write notification will be sent to the guest only when the data has been
1046 reported as written by the storage subsystem
.
1048 Enables exporting
9p share as a readonly mount
for guests
. By
default
1049 read
-write access is given
.
1050 @item socket
=@
var{socket
}
1051 Enables proxy filesystem driver to use passed socket file
for communicating
1052 with virtfs
-proxy
-helper
1053 @item sock_fd
=@
var{sock_fd
}
1054 Enables proxy filesystem driver to use passed socket descriptor
for
1055 communicating with virtfs
-proxy
-helper
. Usually a helper like libvirt
1056 will create socketpair and pass one of the fds as sock_fd
1057 @item fmode
=@
var{fmode
}
1058 Specifies the
default mode
for newly created files on the host
. Works only
1059 with security models
"mapped-xattr" and
"mapped-file".
1060 @item dmode
=@
var{dmode
}
1061 Specifies the
default mode
for newly created directories on the host
. Works
1062 only with security models
"mapped-xattr" and
"mapped-file".
1065 -fsdev option is used along with
-device driver
"virtio-9p-pci".
1066 @item
-device virtio
-9p
-pci
,fsdev
=@
var{id
},mount_tag
=@
var{mount_tag
}
1067 Options
for virtio
-9p
-pci driver are
:
1069 @item fsdev
=@
var{id
}
1070 Specifies the id value specified along with
-fsdev option
1071 @item mount_tag
=@
var{mount_tag
}
1072 Specifies the tag name to be used by the guest to mount
this export point
1077 DEF("virtfs", HAS_ARG
, QEMU_OPTION_virtfs
,
1078 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1079 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1084 @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
}]
1087 The general form of a Virtual File system pass
-through options are
:
1089 @item @
var{fsdriver
}
1090 This option specifies the fs driver backend to use
.
1091 Currently
"local" and
"proxy" file system drivers are supported
.
1093 Specifies identifier
for this device
1094 @item path
=@
var{path
}
1095 Specifies the export path
for the file system device
. Files under
1096 this path will be available to the
9p client on the guest
.
1097 @item security_model
=@
var{security_model
}
1098 Specifies the security model to be used
for this export path
.
1099 Supported security models are
"passthrough", "mapped-xattr", "mapped-file" and
"none".
1100 In
"passthrough" security model
, files are stored
using the same
1101 credentials as they are created on the guest
. This requires QEMU
1102 to run as root
. In
"mapped-xattr" security model
, some of the file
1103 attributes like uid
, gid
, mode bits and link target are stored as
1104 file attributes
. For
"mapped-file" these attributes are stored
in the
1105 hidden
.virtfs_metadata directory
. Directories exported by
this security model cannot
1106 interact with other unix tools
. "none" security model is same as
1107 passthrough except the sever won
't report failures if it fails to
1108 set file attributes like ownership. Security model is mandatory only
1109 for local fsdriver. Other fsdrivers (like proxy) don't take security
1110 model as a parameter
.
1111 @item writeout
=@
var{writeout
}
1112 This is an optional argument
. The only supported value is
"immediate".
1113 This means that host page cache will be used to read and write data but
1114 write notification will be sent to the guest only when the data has been
1115 reported as written by the storage subsystem
.
1117 Enables exporting
9p share as a readonly mount
for guests
. By
default
1118 read
-write access is given
.
1119 @item socket
=@
var{socket
}
1120 Enables proxy filesystem driver to use passed socket file
for
1121 communicating with virtfs
-proxy
-helper
. Usually a helper like libvirt
1122 will create socketpair and pass one of the fds as sock_fd
1124 Enables proxy filesystem driver to use passed
'sock_fd' as the socket
1125 descriptor
for interfacing with virtfs
-proxy
-helper
1126 @item fmode
=@
var{fmode
}
1127 Specifies the
default mode
for newly created files on the host
. Works only
1128 with security models
"mapped-xattr" and
"mapped-file".
1129 @item dmode
=@
var{dmode
}
1130 Specifies the
default mode
for newly created directories on the host
. Works
1131 only with security models
"mapped-xattr" and
"mapped-file".
1135 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth
,
1136 "-virtfs_synth Create synthetic file system image\n",
1140 @findex
-virtfs_synth
1141 Create synthetic file system image
1144 DEF("iscsi", HAS_ARG
, QEMU_OPTION_iscsi
,
1145 "-iscsi [user=user][,password=password]\n"
1146 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1147 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1148 " [,timeout=timeout]\n"
1149 " iSCSI session parameters\n", QEMU_ARCH_ALL
)
1154 Configure iSCSI session parameters
.
1162 DEFHEADING(USB options
:)
1167 DEF("usb", 0, QEMU_OPTION_usb
,
1168 "-usb enable the USB driver (if it is not used by default yet)\n",
1173 Enable the USB
driver (if it is not used by
default yet
).
1176 DEF("usbdevice", HAS_ARG
, QEMU_OPTION_usbdevice
,
1177 "-usbdevice name add the host or guest USB device 'name'\n",
1181 @item
-usbdevice @
var{devname
}
1183 Add the USB device @
var{devname
}. Note that
this option is deprecated
,
1184 please use @code
{-device usb
-...} instead
. @xref
{usb_devices
}.
1189 Virtual Mouse
. This will
override the PS
/2 mouse emulation when activated
.
1192 Pointer device that uses absolute
coordinates (like a touchscreen
). This
1193 means QEMU is able to report the mouse position without having to grab the
1194 mouse
. Also overrides the PS
/2 mouse emulation when activated
.
1197 Braille device
. This will use BrlAPI to display the braille output on a real
1208 DEFHEADING(Display options
:)
1213 DEF("display", HAS_ARG
, QEMU_OPTION_display
,
1214 "-display spice-app[,gl=on|off]\n"
1215 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1216 " [,window_close=on|off][,gl=on|core|es|off]\n"
1217 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1218 "-display vnc=<display>[,<optargs>]\n"
1219 "-display curses[,charset=<encoding>]\n"
1221 "-display egl-headless[,rendernode=<file>]"
1222 " select display type\n"
1223 "The default display is equivalent to\n"
1224 #
if defined(CONFIG_GTK
)
1225 "\t\"-display gtk\"\n"
1226 #elif
defined(CONFIG_SDL
)
1227 "\t\"-display sdl\"\n"
1228 #elif
defined(CONFIG_COCOA
)
1229 "\t\"-display cocoa\"\n"
1230 #elif
defined(CONFIG_VNC
)
1231 "\t\"-vnc localhost:0,to=99,id=default\"\n"
1233 "\t\"-display none\"\n"
1237 @item
-display @
var{type
}
1239 Select type of display to use
. This option is a replacement
for the
1240 old style
-sdl
/-curses
/... options
. Valid values
for @
var{type
} are
1243 Display video output via
SDL (usually
in a separate graphics
1244 window
; see the SDL documentation
for other possibilities
).
1246 Display video output via curses
. For graphics device models which
1247 support a text mode
, QEMU can display
this output
using a
1248 curses
/ncurses
interface. Nothing is displayed when the graphics
1249 device is
in graphical mode or
if the graphics device does not support
1250 a text mode
. Generally only the VGA device models support text mode
.
1251 The font charset used by the guest can be specified with the
1252 @code
{charset
} option
, for example @code
{charset
=CP850
} for IBM CP850
1253 encoding
. The
default is @code
{CP437
}.
1255 Do not display video output
. The guest will still see an emulated
1256 graphics card
, but its output will not be displayed to the QEMU
1257 user
. This option differs from the
-nographic option
in that it
1258 only affects what is done with video output
; -nographic also changes
1259 the destination of the serial and parallel port data
.
1261 Display video output
in a GTK window
. This
interface provides drop
-down
1262 menus and other UI elements to configure and control the VM during
1265 Start a VNC server on display
<arg
>
1267 Offload all OpenGL operations to a local DRI device
. For any graphical display
,
1268 this display needs to be paired with either VNC or SPICE displays
.
1270 Start QEMU as a Spice server and launch the
default Spice client
1271 application
. The Spice server will redirect the serial consoles and
1272 QEMU monitors
. (Since
4.0)
1276 DEF("nographic", 0, QEMU_OPTION_nographic
,
1277 "-nographic disable graphical output and redirect serial I/Os to console\n",
1282 Normally
, if QEMU is compiled with graphical window support
, it displays
1283 output such as guest graphics
, guest console
, and the QEMU monitor
in a
1284 window
. With
this option
, you can totally disable graphical output so
1285 that QEMU is a simple command line application
. The emulated serial port
1286 is redirected on the console and muxed with the
monitor (unless
1287 redirected elsewhere explicitly
). Therefore
, you can still use QEMU to
1288 debug a Linux kernel with a serial console
. Use @key
{C
-a h
} for help on
1289 switching between the console and monitor
.
1292 DEF("curses", 0, QEMU_OPTION_curses
,
1293 "-curses shorthand for -display curses\n",
1298 Normally
, if QEMU is compiled with graphical window support
, it displays
1299 output such as guest graphics
, guest console
, and the QEMU monitor
in a
1300 window
. With
this option
, QEMU can display the VGA output when
in text
1301 mode
using a curses
/ncurses
interface. Nothing is displayed
in graphical
1305 DEF("alt-grab", 0, QEMU_OPTION_alt_grab
,
1306 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1311 Use Ctrl
-Alt
-Shift to grab
mouse (instead of Ctrl
-Alt
). Note that
this also
1312 affects the special
keys (for fullscreen
, monitor
-mode switching
, etc
).
1315 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab
,
1316 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1321 Use Right
-Ctrl to grab
mouse (instead of Ctrl
-Alt
). Note that
this also
1322 affects the special
keys (for fullscreen
, monitor
-mode switching
, etc
).
1325 DEF("no-quit", 0, QEMU_OPTION_no_quit
,
1326 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL
)
1330 Disable SDL window close capability
.
1333 DEF("sdl", 0, QEMU_OPTION_sdl
,
1334 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL
)
1341 DEF("spice", HAS_ARG
, QEMU_OPTION_spice
,
1342 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1343 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1344 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1345 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1346 " [,tls-ciphers=<list>]\n"
1347 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1348 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1349 " [,sasl][,password=<secret>][,disable-ticketing]\n"
1350 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1351 " [,jpeg-wan-compression=[auto|never|always]]\n"
1352 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
1353 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1354 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1355 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1356 " [,gl=[on|off]][,rendernode=<file>]\n"
1358 " at least one of {port, tls-port} is mandatory\n",
1361 @item
-spice @
var{option
}[,@
var{option
}[,...]]
1363 Enable the spice remote desktop protocol
. Valid options are
1368 Set the TCP port spice is listening on
for plaintext channels
.
1371 Set the IP address spice is listening on
. Default is any address
.
1376 Force
using the specified IP version
.
1378 @item password
=<secret
>
1379 Set the password you need to authenticate
.
1382 Require that the client use SASL to authenticate with the spice
.
1383 The exact choice of authentication method used is controlled from the
1384 system
/ user
's SASL configuration file for the 'qemu
' service. This
1385 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1386 unprivileged user, an environment variable SASL_CONF_PATH can be used
1387 to make it search alternate locations for the service config.
1388 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1389 it is recommended that SASL always be combined with the 'tls
' and
1390 'x509
' settings to enable use of SSL and server certificates. This
1391 ensures a data encryption preventing compromise of authentication
1394 @item disable-ticketing
1395 Allow client connects without authentication.
1397 @item disable-copy-paste
1398 Disable copy paste between the client and the guest.
1400 @item disable-agent-file-xfer
1401 Disable spice-vdagent based file-xfer between the client and the guest.
1404 Set the TCP port spice is listening on for encrypted channels.
1406 @item x509-dir=<dir>
1407 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1409 @item x509-key-file=<file>
1410 @itemx x509-key-password=<file>
1411 @itemx x509-cert-file=<file>
1412 @itemx x509-cacert-file=<file>
1413 @itemx x509-dh-key-file=<file>
1414 The x509 file names can also be configured individually.
1416 @item tls-ciphers=<list>
1417 Specify which ciphers to use.
1419 @item tls-channel=[main|display|cursor|inputs|record|playback]
1420 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1421 Force specific channel to be used with or without TLS encryption. The
1422 options can be specified multiple times to configure multiple
1423 channels. The special name "default" can be used to set the default
1424 mode. For channels which are not explicitly forced into one mode the
1425 spice client is allowed to pick tls/plaintext as he pleases.
1427 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1428 Configure image compression (lossless).
1429 Default is auto_glz.
1431 @item jpeg-wan-compression=[auto|never|always]
1432 @itemx zlib-glz-wan-compression=[auto|never|always]
1433 Configure wan image compression (lossy for slow links).
1436 @item streaming-video=[off|all|filter]
1437 Configure video stream detection. Default is off.
1439 @item agent-mouse=[on|off]
1440 Enable/disable passing mouse events via vdagent. Default is on.
1442 @item playback-compression=[on|off]
1443 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1445 @item seamless-migration=[on|off]
1446 Enable/disable spice seamless migration. Default is off.
1449 Enable/disable OpenGL context. Default is off.
1451 @item rendernode=<file>
1452 DRM render node for OpenGL rendering. If not specified, it will pick
1453 the first available. (Since 2.9)
1458 DEF("portrait", 0, QEMU_OPTION_portrait,
1459 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1464 Rotate graphical output 90 deg left (only PXA LCD).
1467 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1468 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1471 @item -rotate @var{deg}
1473 Rotate graphical output some deg left (only PXA LCD).
1476 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1477 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1478 " select video card type\n", QEMU_ARCH_ALL)
1480 @item -vga @var{type}
1482 Select type of VGA card to emulate. Valid values for @var{type} are
1485 Cirrus Logic GD5446 Video card. All Windows versions starting from
1486 Windows 95 should recognize and use this graphic card. For optimal
1487 performances, use 16 bit color depth in the guest and the host OS.
1488 (This card was the default before QEMU 2.2)
1490 Standard VGA card with Bochs VBE extensions. If your guest OS
1491 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1492 to use high resolution modes (>= 1280x1024x16) then you should use
1493 this option. (This card is the default since QEMU 2.2)
1495 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1496 recent XFree86/XOrg server or Windows guest with a driver for this
1499 QXL paravirtual graphic card. It is VGA compatible (including VESA
1500 2.0 VBE support). Works best with qxl guest drivers installed though.
1501 Recommended choice when using the spice protocol.
1503 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1504 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1505 fixed resolution of 1024x768.
1507 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1508 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1509 resolutions aimed at people wishing to run older Solaris versions.
1517 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1518 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1521 @findex -full-screen
1522 Start in full screen.
1525 DEF("g", 1, QEMU_OPTION_g ,
1526 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1527 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1529 @item -g @var{width}x@var{height}[x@var{depth}]
1531 Set the initial graphical resolution and depth (PPC, SPARC only).
1534 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1535 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1537 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1539 Normally, if QEMU is compiled with graphical window support, it displays
1540 output such as guest graphics, guest console, and the QEMU monitor in a
1541 window. With this option, you can have QEMU listen on VNC display
1542 @var{display} and redirect the VGA display over the VNC session. It is
1543 very useful to enable the usb tablet device when using this option
1544 (option @option{-device usb-tablet}). When using the VNC display, you
1545 must use the @option{-k} parameter to set the keyboard layout if you are
1546 not using en-us. Valid syntax for the @var{display} is
1552 With this option, QEMU will try next available VNC @var{display}s, until the
1553 number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1554 available, e.g. port 5900+@var{display} is already used by another
1555 application. By default, to=0.
1557 @item @var{host}:@var{d}
1559 TCP connections will only be allowed from @var{host} on display @var{d}.
1560 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1561 be omitted in which case the server will accept connections from any host.
1563 @item unix:@var{path}
1565 Connections will be allowed over UNIX domain sockets where @var{path} is the
1566 location of a unix socket to listen for connections on.
1570 VNC is initialized but not started. The monitor @code{change} command
1571 can be used to later start the VNC server.
1575 Following the @var{display} value there may be one or more @var{option} flags
1576 separated by commas. Valid options are
1582 Connect to a listening VNC client via a ``reverse'' connection. The
1583 client is specified by the @var{display}. For reverse network
1584 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1585 is a TCP port number, not a display number.
1589 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1590 If a bare @var{websocket} option is given, the Websocket port is
1591 5700+@var{display}. An alternative port can be specified with the
1592 syntax @code{websocket}=@var{port}.
1594 If @var{host} is specified connections will only be allowed from this host.
1595 It is possible to control the websocket listen address independently, using
1596 the syntax @code{websocket}=@var{host}:@var{port}.
1598 If no TLS credentials are provided, the websocket connection runs in
1599 unencrypted mode. If TLS credentials are provided, the websocket connection
1600 requires encrypted client connections.
1604 Require that password based authentication is used for client connections.
1606 The password must be set separately using the @code{set_password} command in
1607 the @ref{pcsys_monitor}. The syntax to change your password is:
1608 @code{set_password <protocol> <password>} where <protocol> could be either
1611 If you would like to change <protocol> password expiration, you should use
1612 @code{expire_password <protocol> <expiration-time>} where expiration time could
1613 be one of the following options: now, never, +seconds or UNIX time of
1614 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1615 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1618 You can also use keywords "now" or "never" for the expiration time to
1619 allow <protocol> password to expire immediately or never expire.
1621 @item tls-creds=@var{ID}
1623 Provides the ID of a set of TLS credentials to use to secure the
1624 VNC server. They will apply to both the normal VNC server socket
1625 and the websocket socket (if enabled). Setting TLS credentials
1626 will cause the VNC server socket to enable the VeNCrypt auth
1627 mechanism. The credentials should have been previously created
1628 using the @option{-object tls-creds} argument.
1630 @item tls-authz=@var{ID}
1632 Provides the ID of the QAuthZ authorization object against which
1633 the client's x509 distinguished name will validated
. This object is
1634 only resolved at time of use
, so can be deleted and recreated on the
1635 fly
while the VNC server is active
. If missing
, it will
default
1640 Require that the client use SASL to authenticate with the VNC server
.
1641 The exact choice of authentication method used is controlled from the
1642 system
/ user
's SASL configuration file for the 'qemu
' service. This
1643 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1644 unprivileged user, an environment variable SASL_CONF_PATH can be used
1645 to make it search alternate locations for the service config.
1646 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1647 it is recommended that SASL always be combined with the 'tls
' and
1648 'x509
' settings to enable use of SSL and server certificates. This
1649 ensures a data encryption preventing compromise of authentication
1650 credentials. See the @ref{vnc_security} section for details on using
1651 SASL authentication.
1653 @item sasl-authz=@var{ID}
1655 Provides the ID of the QAuthZ authorization object against which
1656 the client's SASL username will validated
. This object is
1657 only resolved at time of use
, so can be deleted and recreated on the
1658 fly
while the VNC server is active
. If missing
, it will
default
1663 Legacy method
for enabling authorization of clients against the
1664 x509 distinguished name and SASL username
. It results
in the creation
1665 of two @code
{authz
-list
} objects with IDs of @code
{vnc
.username
} and
1666 @code
{vnc
.x509dname
}. The rules
for these objects must be configured
1667 with the HMP ACL commands
.
1669 This option is deprecated and should no longer be used
. The
new
1670 @option
{sasl
-authz
} and @option
{tls
-authz
} options are a
1675 Enable lossy compression
methods (gradient
, JPEG
, ...). If
this
1676 option is set
, VNC client may receive lossy framebuffer updates
1677 depending on its encoding settings
. Enabling
this option can save
1678 a lot of bandwidth at the expense of quality
.
1682 Disable adaptive encodings
. Adaptive encodings are enabled by
default.
1683 An adaptive encoding will
try to detect frequently updated screen regions
,
1684 and send updates
in these regions
using a lossy
encoding (like JPEG
).
1685 This can be really helpful to save bandwidth when playing videos
. Disabling
1686 adaptive encodings restores the original
static behavior of encodings
1689 @item share
=[allow
-exclusive|force
-shared|ignore
]
1691 Set display sharing policy
. 'allow-exclusive' allows clients to ask
1692 for exclusive access
. As suggested by the rfb spec
this is
1693 implemented by dropping other connections
. Connecting multiple
1694 clients
in parallel requires all clients asking
for a shared session
1695 (vncviewer
: -shared
switch). This is the
default. 'force-shared'
1696 disables exclusive client access
. Useful
for shared desktop sessions
,
1697 where you don
't want someone forgetting specify -shared disconnect
1698 everybody else. 'ignore
' completely ignores the shared flag and
1699 allows everybody connect unconditionally. Doesn't conform to the rfb
1700 spec but is traditional QEMU behavior
.
1704 Set keyboard delay
, for key down and key up events
, in milliseconds
.
1705 Default is
10. Keyboards are low
-bandwidth devices
, so
this slowdown
1706 can help the device and guest to keep up and not lose events
in case
1707 events are arriving
in bulk
. Possible causes
for the latter are flaky
1708 network connections
, or scripts
for automated testing
.
1716 ARCHHEADING(, QEMU_ARCH_I386
)
1718 ARCHHEADING(i386 target only
:, QEMU_ARCH_I386
)
1723 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack
,
1724 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1729 Use it when installing Windows
2000 to avoid a disk full bug
. After
1730 Windows
2000 is installed
, you no longer need
this option (this option
1731 slows down the IDE transfers
).
1734 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk
,
1735 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1738 @item
-no
-fd
-bootchk
1739 @findex
-no
-fd
-bootchk
1740 Disable boot signature checking
for floppy disks
in BIOS
. May
1741 be needed to boot from old floppy disks
.
1744 DEF("no-acpi", 0, QEMU_OPTION_no_acpi
,
1745 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM
)
1749 Disable
ACPI (Advanced Configuration and Power Interface
) support
. Use
1750 it
if your guest OS complains about ACPI
problems (PC target machine
1754 DEF("no-hpet", 0, QEMU_OPTION_no_hpet
,
1755 "-no-hpet disable HPET\n", QEMU_ARCH_I386
)
1759 Disable HPET support
.
1762 DEF("acpitable", HAS_ARG
, QEMU_OPTION_acpitable
,
1763 "-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"
1764 " ACPI table description\n", QEMU_ARCH_I386
)
1766 @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
}]...]
1768 Add ACPI table with specified header fields and context from specified files
.
1769 For file
=, take whole ACPI table from the specified files
, including all
1770 ACPI
headers (possible overridden by other options
).
1771 For data
=, only data
1772 portion of the table is used
, all header information is specified
in the
1774 If a SLIC table is supplied to QEMU
, then the SLIC
's oem_id and oem_table_id
1775 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1776 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1780 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1781 "-smbios file=binary\n"
1782 " load SMBIOS entry from binary file\n"
1783 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1785 " specify SMBIOS type 0 fields\n"
1786 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1787 " [,uuid=uuid][,sku=str][,family=str]\n"
1788 " specify SMBIOS type 1 fields\n"
1789 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1790 " [,asset=str][,location=str]\n"
1791 " specify SMBIOS type 2 fields\n"
1792 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1794 " specify SMBIOS type 3 fields\n"
1795 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1796 " [,asset=str][,part=str]\n"
1797 " specify SMBIOS type 4 fields\n"
1798 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1799 " [,asset=str][,part=str][,speed=%d]\n"
1800 " specify SMBIOS type 17 fields\n",
1801 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1803 @item -smbios file=@var{binary}
1805 Load SMBIOS entry from binary file.
1807 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1808 Specify SMBIOS type 0 fields
1810 @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}]
1811 Specify SMBIOS type 1 fields
1813 @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}]
1814 Specify SMBIOS type 2 fields
1816 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1817 Specify SMBIOS type 3 fields
1819 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1820 Specify SMBIOS type 4 fields
1822 @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}]
1823 Specify SMBIOS type 17 fields
1831 DEFHEADING(Network options:)
1836 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1838 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1839 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1840 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1841 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
1842 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1844 "[,smb=dir[,smbserver=addr]]\n"
1846 " configure a user mode network backend with ID 'str
',\n"
1847 " its DHCP server and optional services\n"
1850 "-netdev tap,id=str,ifname=name\n"
1851 " configure a host TAP network backend with ID 'str
'\n"
1853 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1854 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1855 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1857 " configure a host TAP network backend with ID 'str
'\n"
1858 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1859 " use network scripts 'file
' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1860 " to configure it and 'dfile
' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1861 " to deconfigure it\n"
1862 " use '[down
]script
=no
' to disable script execution\n"
1863 " use network helper 'helper
' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1865 " use 'fd
=h
' to connect to an already opened TAP interface\n"
1866 " use 'fds
=x
:y
:...:z
' to connect to already opened multiqueue capable TAP interfaces\n"
1867 " use 'sndbuf
=nbytes
' to limit the size of the send buffer (the\n"
1868 " default is disabled 'sndbuf
=0' to enable flow control set 'sndbuf
=1048576')\n"
1869 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1870 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1871 " use vhost=on to enable experimental in kernel accelerator\n"
1872 " (only has effect for virtio guests which use MSIX)\n"
1873 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1874 " use 'vhostfd
=h
' to connect to an already opened vhost net device\n"
1875 " use 'vhostfds
=x
:y
:...:z to connect to multiple already opened vhost net devices
\n"
1876 " use
'queues=n' to specify the number of queues to be created
for multiqueue TAP
\n"
1877 " use
'poll-us=n' to speciy the maximum number of microseconds that could be
\n"
1878 " spent on busy polling
for vhost net
\n"
1879 "-netdev bridge
,id
=str
[,br
=bridge
][,helper
=helper
]\n"
1880 " configure a host TAP network backend with ID
'str' that is
\n"
1881 " connected to a
bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1882 " using the program
'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1885 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1886 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1887 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1888 " [,rxcookie=rxcookie][,offset=offset]\n"
1889 " configure a network backend with ID 'str
' connected to\n"
1890 " an Ethernet over L2TPv3 pseudowire.\n"
1891 " Linux kernel 3.3+ as well as most routers can talk\n"
1892 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1893 " VM to a router and even VM to Host. It is a nearly-universal\n"
1894 " standard (RFC3391). Note - this implementation uses static\n"
1895 " pre-configured tunnels (same as the Linux kernel).\n"
1896 " use 'src
=' to specify source address\n"
1897 " use 'dst
=' to specify destination address\n"
1898 " use 'udp
=on
' to specify udp encapsulation\n"
1899 " use 'srcport
=' to specify source udp port\n"
1900 " use 'dstport
=' to specify destination udp port\n"
1901 " use 'ipv6
=on
' to force v6\n"
1902 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1903 " well as a weak security measure\n"
1904 " use 'rxcookie
=0x012345678' to specify a rxcookie\n"
1905 " use 'txcookie
=0x012345678' to specify a txcookie\n"
1906 " use 'cookie64
=on
' to set cookie size to 64 bit, otherwise 32\n"
1907 " use 'counter
=off
' to force a 'cut
-down
' L2TPv3 with no counter\n"
1908 " use 'pincounter
=on
' to work around broken counter handling in peer\n"
1909 " use 'offset
=X
' to add an extra offset between header and data\n"
1911 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1912 " configure a network backend to connect to another network\n"
1913 " using a socket connection\n"
1914 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1915 " configure a network backend to connect to a multicast maddr and port\n"
1916 " use 'localaddr
=addr
' to specify the host address to send packets from\n"
1917 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1918 " configure a network backend to connect to another network\n"
1919 " using an UDP tunnel\n"
1921 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1922 " configure a network backend to connect to port 'n
' of a vde switch\n"
1923 " running on host and listening for incoming connections on 'socketpath
'.\n"
1924 " Use group 'groupname
' and mode 'octalmode
' to change default\n"
1925 " ownership and permissions for communication port.\n"
1927 #ifdef CONFIG_NETMAP
1928 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1929 " attach to the existing netmap-enabled network interface 'name
', or to a\n"
1930 " VALE port (created on the fly) called 'name
' ('nmname
' is name of the \n"
1931 " netmap device, defaults to '/dev
/netmap
')\n"
1934 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1935 " configure a vhost-user network, backed by a chardev 'dev
'\n"
1937 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
1938 " configure a hub port on the hub with ID 'n
'\n", QEMU_ARCH_ALL)
1939 DEF("nic", HAS_ARG, QEMU_OPTION_nic,
1950 #ifdef CONFIG_NETMAP
1956 "socket][,option][,...][mac=macaddr]\n"
1957 " initialize an on-board / default host NIC (using MAC address\n"
1958 " macaddr) and connect it to the given host network backend\n"
1959 "-nic none use it alone to have zero network devices (the default is to\n"
1960 " provided a 'user
' network connection)\n",
1962 DEF("net", HAS_ARG, QEMU_OPTION_net,
1963 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1964 " configure or create an on-board (or machine default) NIC and\n"
1965 " connect it to hub 0 (please use -nic unless you need a hub)\n"
1975 #ifdef CONFIG_NETMAP
1978 "socket][,option][,option][,...]\n"
1979 " old way to initialize a host network interface\n"
1980 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
1982 @item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]
1984 This option is a shortcut for configuring both the on-board (default) guest
1985 NIC hardware and the host network backend in one go. The host backend options
1986 are the same as with the corresponding @option{-netdev} options below.
1987 The guest NIC model can be set with @option{model=@var{modelname}}.
1988 Use @option{model=help} to list the available device types.
1989 The hardware MAC address can be set with @option{mac=@var{macaddr}}.
1991 The following two example do exactly the same, to show how @option{-nic} can
1992 be used to shorten the command line length (note that the e1000 is the default
1993 on i386, so the @option{model=e1000} parameter could even be omitted here, too):
1995 qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
1996 qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2000 Indicate that no network devices should be configured. It is used to override
2001 the default configuration (default NIC with ``user'' host network backend)
2002 which is activated if no other networking options are provided.
2004 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2006 Configure user mode host network backend which requires no administrator
2007 privilege to run. Valid options are:
2011 Assign symbolic name for use in monitor commands.
2013 @item ipv4=on|off and ipv6=on|off
2014 Specify that either IPv4 or IPv6 must be enabled. If neither is specified
2015 both protocols are enabled.
2017 @item net=@var{addr}[/@var{mask}]
2018 Set IP network address the guest will see. Optionally specify the netmask,
2019 either in the form a.b.c.d or as number of valid top-most bits. Default is
2022 @item host=@var{addr}
2023 Specify the guest-visible address of the host. Default is the 2nd IP in the
2024 guest network, i.e. x.x.x.2.
2026 @item ipv6-net=@var{addr}[/@var{int}]
2027 Set IPv6 network address the guest will see (default is fec0::/64). The
2028 network prefix is given in the usual hexadecimal IPv6 address
2029 notation. The prefix size is optional, and is given as the number of
2030 valid top-most bits (default is 64).
2032 @item ipv6-host=@var{addr}
2033 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2034 the guest network, i.e. xxxx::2.
2036 @item restrict=on|off
2037 If this option is enabled, the guest will be isolated, i.e. it will not be
2038 able to contact the host and no guest IP packets will be routed over the host
2039 to the outside. This option does not affect any explicitly set forwarding rules.
2041 @item hostname=@var{name}
2042 Specifies the client hostname reported by the built-in DHCP server.
2044 @item dhcpstart=@var{addr}
2045 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2046 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2048 @item dns=@var{addr}
2049 Specify the guest-visible address of the virtual nameserver. The address must
2050 be different from the host address. Default is the 3rd IP in the guest network,
2053 @item ipv6-dns=@var{addr}
2054 Specify the guest-visible address of the IPv6 virtual nameserver. The address
2055 must be different from the host address. Default is the 3rd IP in the guest
2056 network, i.e. xxxx::3.
2058 @item dnssearch=@var{domain}
2059 Provides an entry for the domain-search list sent by the built-in
2060 DHCP server. More than one domain suffix can be transmitted by specifying
2061 this option multiple times. If supported, this will cause the guest to
2062 automatically try to append the given domain suffix(es) in case a domain name
2063 can not be resolved.
2067 qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2070 @item domainname=@var{domain}
2071 Specifies the client domain name reported by the built-in DHCP server.
2073 @item tftp=@var{dir}
2074 When using the user mode network stack, activate a built-in TFTP
2075 server. The files in @var{dir} will be exposed as the root of a TFTP server.
2076 The TFTP client on the guest must be configured in binary mode (use the command
2077 @code{bin} of the Unix TFTP client).
2079 @item tftp-server-name=@var{name}
2080 In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option
2081 66). This can be used to advise the guest to load boot files or configurations
2082 from a different server than the host address.
2084 @item bootfile=@var{file}
2085 When using the user mode network stack, broadcast @var{file} as the BOOTP
2086 filename. In conjunction with @option{tftp}, this can be used to network boot
2087 a guest from a local directory.
2089 Example (using pxelinux):
2091 qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2092 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2095 @item smb=@var{dir}[,smbserver=@var{addr}]
2096 When using the user mode network stack, activate a built-in SMB
2097 server so that Windows OSes can access to the host files in @file{@var{dir}}
2098 transparently. The IP address of the SMB server can be set to @var{addr}. By
2099 default the 4th IP in the guest network is used, i.e. x.x.x.4.
2101 In the guest Windows OS, the line:
2105 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2106 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2108 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2110 Note that a SAMBA server must be installed on the host OS.
2112 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2113 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2114 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2115 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2116 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2117 be bound to a specific host interface. If no connection type is set, TCP is
2118 used. This option can be given multiple times.
2120 For example, to redirect host X11 connection from screen 1 to guest
2121 screen 0, use the following:
2125 qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2126 # this host xterm should open in the guest X11 server
2130 To redirect telnet connections from host port 5555 to telnet port on
2131 the guest, use the following:
2135 qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2136 telnet localhost 5555
2139 Then when you use on the host @code{telnet localhost 5555}, you
2140 connect to the guest telnet server.
2142 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2143 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2144 Forward guest TCP connections to the IP address @var{server} on port @var{port}
2145 to the character device @var{dev} or to a program executed by @var{cmd:command}
2146 which gets spawned for each connection. This option can be given multiple times.
2148 You can either use a chardev directly and have that one used throughout QEMU's
2149 lifetime
, like
in the following example
:
2152 # open
10.10.1.1:4321 on bootup
, connect
10.0.2.100:1234 to it whenever
2153 # the guest accesses it
2154 qemu
-system
-i386
-nic user
,guestfwd
=tcp
:10.0.2.100:1234-tcp
:10.10.1.1:4321
2157 Or you can execute a command on every TCP connection established by the guest
,
2158 so that QEMU behaves similar to an inetd process
for that virtual server
:
2161 # call
"netcat 10.10.1.1 4321" on every TCP connection to
10.0.2.100:1234
2162 # and connect the TCP stream to its stdin
/stdout
2163 qemu
-system
-i386
-nic
'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2168 @item
-netdev tap
,id
=@
var{id
}[,fd
=@
var{h
}][,ifname
=@
var{name
}][,script
=@
var{file
}][,downscript
=@
var{dfile
}][,br
=@
var{bridge
}][,helper
=@
var{helper
}]
2169 Configure a host TAP network backend with ID @
var{id
}.
2171 Use the network script @
var{file
} to configure it and the network script
2172 @
var{dfile
} to deconfigure it
. If @
var{name
} is not provided
, the OS
2173 automatically provides one
. The
default network configure script is
2174 @file
{/etc
/qemu
-ifup
} and the
default network deconfigure script is
2175 @file
{/etc
/qemu
-ifdown
}. Use @option
{script
=no
} or @option
{downscript
=no
}
2176 to disable script execution
.
2178 If running QEMU as an unprivileged user
, use the network helper
2179 @
var{helper
} to configure the TAP
interface and attach it to the bridge
.
2180 The
default network helper executable is @file
{/path
/to
/qemu
-bridge
-helper
}
2181 and the
default bridge device is @file
{br0
}.
2183 @option
{fd
}=@
var{h
} can be used to specify the handle of an already
2184 opened host TAP
interface.
2189 #launch a QEMU instance with the
default network script
2190 qemu
-system
-i386 linux
.img
-nic tap
2194 #launch a QEMU instance with two NICs
, each one connected
2196 qemu
-system
-i386 linux
.img \
2197 -netdev tap
,id
=nd0
,ifname
=tap0
-device e1000
,netdev
=nd0 \
2198 -netdev tap
,id
=nd1
,ifname
=tap1
-device rtl8139
,netdev
=nd1
2202 #launch a QEMU instance with the
default network helper to
2203 #connect a TAP device to bridge br0
2204 qemu
-system
-i386 linux
.img
-device virtio
-net
-pci
,netdev
=n1 \
2205 -netdev tap
,id
=n1
,"helper=/path/to/qemu-bridge-helper"
2208 @item
-netdev bridge
,id
=@
var{id
}[,br
=@
var{bridge
}][,helper
=@
var{helper
}]
2209 Connect a host TAP network
interface to a host bridge device
.
2211 Use the network helper @
var{helper
} to configure the TAP
interface and
2212 attach it to the bridge
. The
default network helper executable is
2213 @file
{/path
/to
/qemu
-bridge
-helper
} and the
default bridge
2214 device is @file
{br0
}.
2219 #launch a QEMU instance with the
default network helper to
2220 #connect a TAP device to bridge br0
2221 qemu
-system
-i386 linux
.img
-netdev bridge
,id
=n1
-device virtio
-net
,netdev
=n1
2225 #launch a QEMU instance with the
default network helper to
2226 #connect a TAP device to bridge qemubr0
2227 qemu
-system
-i386 linux
.img
-netdev bridge
,br
=qemubr0
,id
=n1
-device virtio
-net
,netdev
=n1
2230 @item
-netdev socket
,id
=@
var{id
}[,fd
=@
var{h
}][,listen
=[@
var{host
}]:@
var{port
}][,connect
=@
var{host
}:@
var{port
}]
2232 This host network backend can be used to connect the guest
's network to
2233 another QEMU virtual machine using a TCP socket connection. If @option{listen}
2234 is specified, QEMU waits for incoming connections on @var{port}
2235 (@var{host} is optional). @option{connect} is used to connect to
2236 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2237 specifies an already opened TCP socket.
2241 # launch a first QEMU instance
2242 qemu-system-i386 linux.img \
2243 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2244 -netdev socket,id=n1,listen=:1234
2245 # connect the network of this instance to the network of the first instance
2246 qemu-system-i386 linux.img \
2247 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2248 -netdev socket,id=n2,connect=127.0.0.1:1234
2251 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2253 Configure a socket host network backend to share the guest's network traffic
2254 with another QEMU virtual machines
using a UDP multicast socket
, effectively
2255 making a bus
for every QEMU with same multicast address @
var{maddr
} and @
var{port
}.
2259 Several QEMU can be running on different hosts and share same
bus (assuming
2260 correct multicast setup
for these hosts
).
2262 mcast support is compatible with User Mode
Linux (argument @option
{eth@
var{N
}=mcast
}), see
2263 @url
{http
://user-mode-linux.sf.net}.
2265 Use @option
{fd
=h
} to specify an already opened UDP multicast socket
.
2270 # launch one QEMU instance
2271 qemu
-system
-i386 linux
.img \
2272 -device e1000
,netdev
=n1
,mac
=52:54:00:12:34:56 \
2273 -netdev socket
,id
=n1
,mcast
=230.0.0.1:1234
2274 # launch another QEMU instance on same
"bus"
2275 qemu
-system
-i386 linux
.img \
2276 -device e1000
,netdev
=n2
,mac
=52:54:00:12:34:57 \
2277 -netdev socket
,id
=n2
,mcast
=230.0.0.1:1234
2278 # launch yet another QEMU instance on same
"bus"
2279 qemu
-system
-i386 linux
.img \
2280 -device e1000
,netdev
=n3
,mac
=52:54:00:12:34:58 \
2281 -netdev socket
,id
=n3
,mcast
=230.0.0.1:1234
2284 Example (User Mode Linux compat
.):
2286 # launch QEMU
instance (note mcast address selected is UML
's default)
2287 qemu-system-i386 linux.img \
2288 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2289 -netdev socket,id=n1,mcast=239.192.168.1:1102
2291 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2294 Example (send packets from host's
1.2.3.4):
2296 qemu
-system
-i386 linux
.img \
2297 -device e1000
,netdev
=n1
,mac
=52:54:00:12:34:56 \
2298 -netdev socket
,id
=n1
,mcast
=239.192.168.1:1102,localaddr
=1.2.3.4
2301 @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
}]
2302 Configure a L2TPv3 pseudowire host network backend
. L2TPv3 (RFC3391
) is a
2303 popular protocol to transport
Ethernet (and other Layer
2) data frames between
2304 two systems
. It is present
in routers
, firewalls and the Linux kernel
2305 (from version
3.3 onwards
).
2307 This transport allows a VM to communicate to another VM
, router or firewall directly
.
2310 @item src
=@
var{srcaddr
}
2311 source
address (mandatory
)
2312 @item dst
=@
var{dstaddr
}
2313 destination
address (mandatory
)
2315 select udp
encapsulation (default is ip
).
2316 @item srcport
=@
var{srcport
}
2318 @item dstport
=@
var{dstport
}
2319 destination udp port
.
2321 force v6
, otherwise defaults to v4
.
2322 @item rxcookie
=@
var{rxcookie
}
2323 @itemx txcookie
=@
var{txcookie
}
2324 Cookies are a weak form of security
in the l2tpv3 specification
.
2325 Their
function is mostly to prevent misconfiguration
. By
default they are
32
2328 Set cookie size to
64 bit instead of the
default 32
2330 Force a
'cut-down' L2TPv3 with no counter as
in
2331 draft
-mkonstan
-l2tpext
-keyed
-ipv6
-tunnel
-00
2333 Work around broken counter handling
in peer
. This may also help on
2334 networks which have packet reorder
.
2335 @item offset
=@
var{offset
}
2336 Add an extra offset between header and data
2339 For example
, to attach a VM running on host
4.3.2.1 via L2TPv3 to the bridge br
-lan
2340 on the remote Linux host
1.2.3.4:
2342 # Setup tunnel on linux host
using raw ip as encapsulation
2344 ip l2tp add tunnel remote
4.3.2.1 local
1.2.3.4 tunnel_id
1 peer_tunnel_id
1 \
2345 encap udp udp_sport
16384 udp_dport
16384
2346 ip l2tp add session tunnel_id
1 name vmtunnel0 session_id \
2347 0xFFFFFFFF peer_session_id
0xFFFFFFFF
2348 ifconfig vmtunnel0 mtu
1500
2349 ifconfig vmtunnel0 up
2350 brctl addif br
-lan vmtunnel0
2354 # launch QEMU instance
- if your network has reorder or is very lossy add
,pincounter
2356 qemu
-system
-i386 linux
.img
-device e1000
,netdev
=n1 \
2357 -netdev l2tpv3
,id
=n1
,src
=4.2.3.1,dst
=1.2.3.4,udp
,srcport
=16384,dstport
=16384,rxsession
=0xffffffff,txsession
=0xffffffff,counter
2361 @item
-netdev vde
,id
=@
var{id
}[,sock
=@
var{socketpath
}][,port
=@
var{n
}][,group
=@
var{groupname
}][,mode
=@
var{octalmode
}]
2362 Configure VDE backend to connect to PORT @
var{n
} of a vde
switch running on host and
2363 listening
for incoming connections on @
var{socketpath
}. Use GROUP @
var{groupname
}
2364 and MODE @
var{octalmode
} to change
default ownership and permissions
for
2365 communication port
. This option is only available
if QEMU has been compiled
2366 with vde support enabled
.
2371 vde_switch
-F
-sock
/tmp
/myswitch
2372 # launch QEMU instance
2373 qemu
-system
-i386 linux
.img
-nic vde
,sock
=/tmp
/myswitch
2376 @item
-netdev vhost
-user
,chardev
=@
var{id
}[,vhostforce
=on|off
][,queues
=n
]
2378 Establish a vhost
-user netdev
, backed by a chardev @
var{id
}. The chardev should
2379 be a unix domain socket backed one
. The vhost
-user uses a specifically defined
2380 protocol to pass vhost ioctl replacement messages to an application on the other
2381 end of the socket
. On non
-MSIX guests
, the feature can be forced with
2382 @
var{vhostforce
}. Use
'queues=@var{n}' to specify the number of queues to
2383 be created
for multiqueue vhost
-user
.
2387 qemu
-m
512 -object memory
-backend
-file
,id
=mem
,size
=512M
,mem
-path
=/hugetlbfs
,share
=on \
2388 -numa node
,memdev
=mem \
2389 -chardev socket
,id
=chr0
,path
=/path
/to
/socket \
2390 -netdev type
=vhost
-user
,id
=net0
,chardev
=chr0 \
2391 -device virtio
-net
-pci
,netdev
=net0
2394 @item
-netdev hubport
,id
=@
var{id
},hubid
=@
var{hubid
}[,netdev
=@
var{nd
}]
2396 Create a hub port on the emulated hub with ID @
var{hubid
}.
2398 The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2399 single netdev
. Alternatively
, you can also connect the hubport to another
2400 netdev with ID @
var{nd
} by
using the @option
{netdev
=@
var{nd
}} option
.
2402 @item
-net nic
[,netdev
=@
var{nd
}][,macaddr
=@
var{mac
}][,model
=@
var{type
}] [,name
=@
var{name
}][,addr
=@
var{addr
}][,vectors
=@
var{v
}]
2404 Legacy option to configure or create an on
-board (or machine
default) Network
2405 Interface
Card(NIC
) and connect it either to the emulated hub with ID
0 (i
.e
.
2406 the
default hub
), or to the netdev @
var{nd
}.
2407 The NIC is an e1000 by
default on the PC target
. Optionally
, the MAC address
2408 can be changed to @
var{mac
}, the device address set to @
var{addr
} (PCI cards
2409 only
), and a @
var{name
} can be assigned
for use
in monitor commands
.
2410 Optionally
, for PCI cards
, you can specify the number @
var{v
} of MSI
-X vectors
2411 that the card should have
; this option currently only affects virtio cards
; set
2412 @
var{v
} = 0 to disable MSI
-X
. If no @option
{-net
} option is specified
, a single
2413 NIC is created
. QEMU can emulate several different models of network card
.
2414 Use @code
{-net nic
,model
=help
} for a list of available devices
for your target
.
2416 @item
-net user|tap|bridge|socket|l2tpv3|vde
[,...][,name
=@
var{name
}]
2417 Configure a host network
backend (with the options corresponding to the same
2418 @option
{-netdev
} option
) and connect it to the emulated hub
0 (the
default
2419 hub
). Use @
var{name
} to specify the name of the hub port
.
2427 DEFHEADING(Character device options
:)
2429 DEF("chardev", HAS_ARG
, QEMU_OPTION_chardev
,
2431 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2432 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2433 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n"
2434 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n"
2435 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n"
2436 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2437 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2438 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2439 " [,logfile=PATH][,logappend=on|off]\n"
2440 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2441 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2442 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2443 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2444 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2445 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2447 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2448 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2450 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2451 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2453 #ifdef CONFIG_BRLAPI
2454 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2456 #
if defined(__linux__
) ||
defined(__sun__
) ||
defined(__FreeBSD__
) \
2457 ||
defined(__NetBSD__
) ||
defined(__OpenBSD__
) ||
defined(__DragonFly__
)
2458 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2459 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2461 #
if defined(__linux__
) ||
defined(__FreeBSD__
) ||
defined(__DragonFly__
)
2462 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2463 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2465 #
if defined(CONFIG_SPICE
)
2466 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2467 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2474 The general form of a character device option is
:
2476 @item
-chardev @
var{backend
},id
=@
var{id
}[,mux
=on|off
][,@
var{options
}]
2497 The specific backend will determine the applicable options
.
2499 Use @code
{-chardev help
} to print all available chardev backend types
.
2501 All devices must have an id
, which can be any string up to
127 characters long
.
2502 It is used to uniquely identify
this device
in other command line directives
.
2504 A character device may be used
in multiplexing mode by multiple front
-ends
.
2505 Specify @option
{mux
=on
} to enable
this mode
.
2506 A multiplexer is a
"1:N" device
, and
here the
"1" end is your specified chardev
2507 backend
, and the
"N" end is the various parts of QEMU that can talk to a chardev
.
2508 If you create a chardev with @option
{id
=myid
} and @option
{mux
=on
}, QEMU will
2509 create a multiplexer with your specified ID
, and you can then configure multiple
2510 front ends to use that chardev ID
for their input
/output
. Up to four different
2511 front ends can be connected to a single multiplexed chardev
. (Without
2512 multiplexing enabled
, a chardev can only be used by a single front end
.)
2513 For instance you could use
this to allow a single stdio chardev to be used by
2514 two serial ports and the QEMU monitor
:
2517 -chardev stdio
,mux
=on
,id
=char0 \
2518 -mon chardev
=char0
,mode
=readline \
2519 -serial chardev
:char0 \
2520 -serial chardev
:char0
2523 You can have more than one multiplexer
in a system configuration
; for instance
2524 you could have a TCP port multiplexed between UART
0 and UART
1, and stdio
2525 multiplexed between the QEMU monitor and a parallel port
:
2528 -chardev stdio
,mux
=on
,id
=char0 \
2529 -mon chardev
=char0
,mode
=readline \
2530 -parallel chardev
:char0 \
2531 -chardev tcp
,...,mux
=on
,id
=char1 \
2532 -serial chardev
:char1 \
2533 -serial chardev
:char1
2536 When you
're using a multiplexed character device, some escape sequences are
2537 interpreted in the input. @xref{mux_keys, Keys in the character backend
2540 Note that some other command line options may implicitly create multiplexed
2541 character backends; for instance @option{-serial mon:stdio} creates a
2542 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2543 and @option{-nographic} also multiplexes the console and the monitor to
2546 There is currently no support for multiplexing in the other direction
2547 (where a single QEMU front end takes input and output from multiple chardevs).
2549 Every backend supports the @option{logfile} option, which supplies the path
2550 to a file to record all data transmitted via the backend. The @option{logappend}
2551 option controls whether the log file will be truncated or appended to when
2556 The available backends are:
2559 @item -chardev null,id=@var{id}
2560 A void device. This device will not emit any data, and will drop any data it
2561 receives. The null backend does not take any options.
2563 @item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,websocket][,reconnect=@var{seconds}][,tls-creds=@var{id}][,tls-authz=@var{id}]
2565 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2566 unix socket will be created if @option{path} is specified. Behaviour is
2567 undefined if TCP options are specified for a unix socket.
2569 @option{server} specifies that the socket shall be a listening socket.
2571 @option{nowait} specifies that QEMU should not block waiting for a client to
2572 connect to a listening socket.
2574 @option{telnet} specifies that traffic on the socket should interpret telnet
2577 @option{websocket} specifies that the socket uses WebSocket protocol for
2580 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2581 the remote end goes away. qemu will delay this many seconds and then attempt
2582 to reconnect. Zero disables reconnecting, and is the default.
2584 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2585 and specifies the id of the TLS credentials to use for the handshake. The
2586 credentials must be previously created with the @option{-object tls-creds}
2589 @option{tls-auth} provides the ID of the QAuthZ authorization object against
2590 which the client's x509 distinguished name will be validated
. This object is
2591 only resolved at time of use
, so can be deleted and recreated on the fly
2592 while the chardev server is active
. If missing
, it will
default to denying
2595 TCP and unix socket options are given below
:
2599 @item TCP options
: port
=@
var{port
}[,host
=@
var{host
}][,to
=@
var{to
}][,ipv4
][,ipv6
][,nodelay
]
2601 @option
{host
} for a listening socket specifies the local address to be bound
.
2602 For a connecting socket species the remote host to connect to
. @option
{host
} is
2603 optional
for listening sockets
. If not specified it defaults to @code
{0.0.0.0}.
2605 @option
{port
} for a listening socket specifies the local port to be bound
. For a
2606 connecting socket specifies the port on the remote host to connect to
.
2607 @option
{port
} can be given as either a port number or a service name
.
2608 @option
{port
} is required
.
2610 @option
{to
} is only relevant to listening sockets
. If it is specified
, and
2611 @option
{port
} cannot be bound
, QEMU will attempt to bind to subsequent ports up
2612 to and including @option
{to
} until it succeeds
. @option
{to
} must be specified
2615 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2616 If neither is specified the socket may use either protocol
.
2618 @option
{nodelay
} disables the Nagle algorithm
.
2620 @item unix options
: path
=@
var{path
}
2622 @option
{path
} specifies the local path of the unix socket
. @option
{path
} is
2627 @item
-chardev udp
,id
=@
var{id
}[,host
=@
var{host
}],port
=@
var{port
}[,localaddr
=@
var{localaddr
}][,localport
=@
var{localport
}][,ipv4
][,ipv6
]
2629 Sends all traffic from the guest to a remote host over UDP
.
2631 @option
{host
} specifies the remote host to connect to
. If not specified it
2632 defaults to @code
{localhost
}.
2634 @option
{port
} specifies the port on the remote host to connect to
. @option
{port
}
2637 @option
{localaddr
} specifies the local address to bind to
. If not specified it
2638 defaults to @code
{0.0.0.0}.
2640 @option
{localport
} specifies the local port to bind to
. If not specified any
2641 available local port will be used
.
2643 @option
{ipv4
} and @option
{ipv6
} specify that either IPv4 or IPv6 must be used
.
2644 If neither is specified the device may use either protocol
.
2646 @item
-chardev msmouse
,id
=@
var{id
}
2648 Forward QEMU
's emulated msmouse events to the guest. @option{msmouse} does not
2651 @item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2653 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2656 @option{width} and @option{height} specify the width and height respectively of
2657 the console, in pixels.
2659 @option{cols} and @option{rows} specify that the console be sized to fit a text
2660 console with the given dimensions.
2662 @item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2664 Create a ring buffer with fixed size @option{size}.
2665 @var{size} must be a power of two and defaults to @code{64K}.
2667 @item -chardev file,id=@var{id},path=@var{path}
2669 Log all traffic received from the guest to a file.
2671 @option{path} specifies the path of the file to be opened. This file will be
2672 created if it does not already exist, and overwritten if it does. @option{path}
2675 @item -chardev pipe,id=@var{id},path=@var{path}
2677 Create a two-way connection to the guest. The behaviour differs slightly between
2678 Windows hosts and other hosts:
2680 On Windows, a single duplex pipe will be created at
2681 @file{\\.pipe\@option{path}}.
2683 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2684 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2685 received by the guest. Data written by the guest can be read from
2686 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2689 @option{path} forms part of the pipe path as described above. @option{path} is
2692 @item -chardev console,id=@var{id}
2694 Send traffic from the guest to QEMU's standard output
. @option
{console
} does not
2697 @option
{console
} is only available on Windows hosts
.
2699 @item
-chardev serial
,id
=@
var{id
},path
=@option
{path
}
2701 Send traffic from the guest to a serial device on the host
.
2703 On Unix hosts serial will actually accept any tty device
,
2704 not only serial lines
.
2706 @option
{path
} specifies the name of the serial device to open
.
2708 @item
-chardev pty
,id
=@
var{id
}
2710 Create a
new pseudo
-terminal on the host and connect to it
. @option
{pty
} does
2711 not take any options
.
2713 @option
{pty
} is not available on Windows hosts
.
2715 @item
-chardev stdio
,id
=@
var{id
}[,signal
=on|off
]
2716 Connect to standard input and standard output of the QEMU process
.
2718 @option
{signal
} controls
if signals are enabled on the terminal
, that includes
2719 exiting QEMU with the key sequence @key
{Control
-c
}. This option is enabled by
2720 default, use @option
{signal
=off
} to disable it
.
2722 @item
-chardev braille
,id
=@
var{id
}
2724 Connect to a local BrlAPI server
. @option
{braille
} does not take any options
.
2726 @item
-chardev tty
,id
=@
var{id
},path
=@
var{path
}
2728 @option
{tty
} is only available on Linux
, Sun
, FreeBSD
, NetBSD
, OpenBSD and
2729 DragonFlyBSD hosts
. It is an alias
for @option
{serial
}.
2731 @option
{path
} specifies the path to the tty
. @option
{path
} is required
.
2733 @item
-chardev parallel
,id
=@
var{id
},path
=@
var{path
}
2734 @itemx
-chardev parport
,id
=@
var{id
},path
=@
var{path
}
2736 @option
{parallel
} is only available on Linux
, FreeBSD and DragonFlyBSD hosts
.
2738 Connect to a local parallel port
.
2740 @option
{path
} specifies the path to the parallel port device
. @option
{path
} is
2743 @item
-chardev spicevmc
,id
=@
var{id
},debug
=@
var{debug
},name
=@
var{name
}
2745 @option
{spicevmc
} is only available when spice support is built
in.
2747 @option
{debug
} debug level
for spicevmc
2749 @option
{name
} name of spice channel to connect to
2751 Connect to a spice virtual machine channel
, such as vdiport
.
2753 @item
-chardev spiceport
,id
=@
var{id
},debug
=@
var{debug
},name
=@
var{name
}
2755 @option
{spiceport
} is only available when spice support is built
in.
2757 @option
{debug
} debug level
for spicevmc
2759 @option
{name
} name of spice port to connect to
2761 Connect to a spice port
, allowing a Spice client to handle the traffic
2762 identified by a
name (preferably a fqdn
).
2770 DEFHEADING(Bluetooth(R
) options
:)
2775 DEF("bt", HAS_ARG
, QEMU_OPTION_bt
, \
2776 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2777 "-bt hci,host[:id]\n" \
2778 " use host's HCI with the given name\n" \
2779 "-bt hci[,vlan=n]\n" \
2780 " emulate a standard HCI in virtual scatternet 'n'\n" \
2781 "-bt vhci[,vlan=n]\n" \
2782 " add host computer to virtual scatternet 'n' using VHCI\n" \
2783 "-bt device:dev[,vlan=n]\n" \
2784 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2789 Defines the
function of the corresponding Bluetooth HCI
. -bt options
2790 are matched with the HCIs present
in the chosen machine type
. For
2791 example when emulating a machine with only one HCI built into it
, only
2792 the first @code
{-bt hci
[...]} option is valid and defines the HCI
's
2793 logic. The Transport Layer is decided by the machine type. Currently
2794 the machines @code{n800} and @code{n810} have one HCI and all other
2797 Note: This option and the whole bluetooth subsystem is considered as deprecated.
2798 If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where
2799 you describe your usecase.
2802 The following three types are recognized:
2806 (default) The corresponding Bluetooth HCI assumes no internal logic
2807 and will not respond to any HCI commands or emit events.
2809 @item -bt hci,host[:@var{id}]
2810 (@code{bluez} only) The corresponding HCI passes commands / events
2811 to / from the physical HCI identified by the name @var{id} (default:
2812 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2813 capable systems like Linux.
2815 @item -bt hci[,vlan=@var{n}]
2816 Add a virtual, standard HCI that will participate in the Bluetooth
2817 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2818 VLANs, devices inside a bluetooth network @var{n} can only communicate
2819 with other devices in the same network (scatternet).
2822 @item -bt vhci[,vlan=@var{n}]
2823 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2824 to the host bluetooth stack instead of to the emulated target. This
2825 allows the host and target machines to participate in a common scatternet
2826 and communicate. Requires the Linux @code{vhci} driver installed. Can
2827 be used as following:
2830 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2833 @item -bt device:@var{dev}[,vlan=@var{n}]
2834 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2835 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2840 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2850 DEFHEADING(TPM device options:)
2852 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2853 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2854 " use path to provide path to a character device; default is /dev/tpm0\n"
2855 " use cancel-path to provide path to TPM's cancel sysfs entry
; if\n"
2856 " not provided it will be searched
for in /sys
/class/misc
/tpm?
/device
\n"
2857 "-tpmdev emulator
,id
=id
,chardev
=dev
\n"
2858 " configure the TPM device
using chardev backend
\n",
2862 The general form of a TPM device option is:
2865 @item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2868 The specific backend type will determine the applicable options.
2869 The @code{-tpmdev} option creates the TPM backend and requires a
2870 @code{-device} option that specifies the TPM frontend interface model.
2872 Use @code{-tpmdev help} to print all available TPM backend types.
2876 The available backends are:
2880 @item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2882 (Linux-host only) Enable access to the host's TPM using the passthrough
2885 @option{path} specifies the path to the host's TPM device, i.e., on
2886 a Linux host this would be @code{/dev/tpm0}.
2887 @option{path} is optional and by default @code{/dev/tpm0} is used.
2889 @option{cancel-path} specifies the path to the host TPM device's sysfs
2890 entry allowing for cancellation of an ongoing TPM command.
2891 @option{cancel-path} is optional and by default QEMU will search for the
2894 Some notes about using the host's TPM with the passthrough driver:
2896 The TPM device accessed by the passthrough driver must not be
2897 used by any other application on the host.
2899 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2900 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2901 TPM again and may therefore not show a TPM-specific menu that would
2902 otherwise allow the user to configure the TPM, e.g., allow the user to
2903 enable/disable or activate/deactivate the TPM.
2904 Further, if TPM ownership is released from within a VM then the host's TPM
2905 will get disabled and deactivated. To enable and activate the
2906 TPM again afterwards, the host has to be rebooted and the user is
2907 required to enter the firmware's menu to enable and activate the TPM.
2908 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2910 To create a passthrough TPM use the following two options:
2912 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2914 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2915 @code{tpmdev=tpm0} in the device option.
2917 @item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2919 (Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2922 @option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2924 To create a TPM emulator backend device with chardev socket backend:
2927 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2940 DEFHEADING(Linux/Multiboot boot specific:)
2943 When using these options, you can use a given Linux or Multiboot
2944 kernel without installing it in the disk image. It can be useful
2945 for easier testing of various kernels.
2950 DEF("kernel
", HAS_ARG, QEMU_OPTION_kernel, \
2951 "-kernel bzImage use
'bzImage' as kernel image
\n", QEMU_ARCH_ALL)
2953 @item -kernel @var{bzImage}
2955 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2956 or in multiboot format.
2959 DEF("append
", HAS_ARG, QEMU_OPTION_append, \
2960 "-append cmdline use
'cmdline' as kernel command line
\n", QEMU_ARCH_ALL)
2962 @item -append @var{cmdline}
2964 Use @var{cmdline} as kernel command line
2967 DEF("initrd
", HAS_ARG, QEMU_OPTION_initrd, \
2968 "-initrd file use
'file' as initial ram disk
\n", QEMU_ARCH_ALL)
2970 @item -initrd @var{file}
2972 Use @var{file} as initial ram disk.
2974 @item -initrd "@
var{file1
} arg
=foo
,@
var{file2
}"
2976 This syntax is only available with multiboot.
2978 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2982 DEF("dtb
", HAS_ARG, QEMU_OPTION_dtb, \
2983 "-dtb file use
'file' as device tree image
\n", QEMU_ARCH_ALL)
2985 @item -dtb @var{file}
2987 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2996 DEFHEADING(Debug/Expert options:)
3001 DEF("fw_cfg
", HAS_ARG, QEMU_OPTION_fwcfg,
3002 "-fw_cfg
[name
=]<name
>,file
=<file
>\n"
3003 " add named fw_cfg entry with contents from file
\n"
3004 "-fw_cfg
[name
=]<name
>,string
=<str
>\n"
3005 " add named fw_cfg entry with contents from string
\n",
3009 @item -fw_cfg [name=]@var{name},file=@var{file}
3011 Add named fw_cfg entry with contents from file @var{file}.
3013 @item -fw_cfg [name=]@var{name},string=@var{str}
3014 Add named fw_cfg entry with contents from string @var{str}.
3016 The terminating NUL character of the contents of @var{str} will not be
3017 included as part of the fw_cfg item data. To insert contents with
3018 embedded NUL characters, you have to use the @var{file} parameter.
3020 The fw_cfg entries are passed by QEMU through to the guest.
3024 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3026 creates an fw_cfg entry named opt/com.mycompany/blob with contents
3031 DEF("serial
", HAS_ARG, QEMU_OPTION_serial, \
3032 "-serial dev redirect the serial port to char device
'dev'\n",
3035 @item -serial @var{dev}
3037 Redirect the virtual serial port to host character device
3038 @var{dev}. The default device is @code{vc} in graphical mode and
3039 @code{stdio} in non graphical mode.
3041 This option can be used several times to simulate up to 4 serial
3044 Use @code{-serial none} to disable all serial ports.
3046 Available character devices are:
3048 @item vc[:@var{W}x@var{H}]
3049 Virtual console. Optionally, a width and height can be given in pixel with
3053 It is also possible to specify width or height in characters:
3058 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3060 No device is allocated.
3063 @item chardev:@var{id}
3064 Use a named character device defined with the @code{-chardev} option.
3066 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3067 parameters are set according to the emulated ones.
3068 @item /dev/parport@var{N}
3069 [Linux only, parallel port only] Use host parallel port
3070 @var{N}. Currently SPP and EPP parallel port features can be used.
3071 @item file:@var{filename}
3072 Write output to @var{filename}. No character can be read.
3074 [Unix only] standard input/output
3075 @item pipe:@var{filename}
3076 name pipe @var{filename}
3078 [Windows only] Use host serial port @var{n}
3079 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3080 This implements UDP Net Console.
3081 When @var{remote_host} or @var{src_ip} are not specified
3082 they default to @code{0.0.0.0}.
3083 When not using a specified @var{src_port} a random port is automatically chosen.
3085 If you just want a simple readonly console you can use @code{netcat} or
3086 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3087 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3088 will appear in the netconsole session.
3090 If you plan to send characters back via netconsole or you want to stop
3091 and start QEMU a lot of times, you should have QEMU use the same
3092 source port each time by using something like @code{-serial
3093 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3094 version of netcat which can listen to a TCP port and send and receive
3095 characters via udp. If you have a patched version of netcat which
3096 activates telnet remote echo and single char transfer, then you can
3097 use the following options to set up a netcat redirector to allow
3098 telnet on port 5555 to access the QEMU port.
3101 -serial udp::4555@@:4556
3102 @item netcat options:
3103 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3104 @item telnet options:
3108 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3109 The TCP Net Console has two modes of operation. It can send the serial
3110 I/O to a location or wait for a connection from a location. By default
3111 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3112 the @var{server} option QEMU will wait for a client socket application
3113 to connect to the port before continuing, unless the @code{nowait}
3114 option was specified. The @code{nodelay} option disables the Nagle buffering
3115 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3116 set, if the connection goes down it will attempt to reconnect at the
3117 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3118 one TCP connection at a time is accepted. You can use @code{telnet} to
3119 connect to the corresponding character device.
3121 @item Example to send tcp console to 192.168.0.2 port 4444
3122 -serial tcp:192.168.0.2:4444
3123 @item Example to listen and wait on port 4444 for connection
3124 -serial tcp::4444,server
3125 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3126 -serial tcp:192.168.0.100:4444,server,nowait
3129 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3130 The telnet protocol is used instead of raw tcp sockets. The options
3131 work the same as if you had specified @code{-serial tcp}. The
3132 difference is that the port acts like a telnet server or client using
3133 telnet option negotiation. This will also allow you to send the
3134 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3135 sequence. Typically in unix telnet you do it with Control-] and then
3136 type "send
break" followed by pressing the enter key.
3138 @item websocket:@var{host}:@var{port},server[,nowait][,nodelay]
3139 The WebSocket protocol is used instead of raw tcp socket. The port acts as
3140 a WebSocket server. Client mode is not supported.
3142 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3143 A unix domain socket is used instead of a tcp socket. The option works the
3144 same as if you had specified @code{-serial tcp} except the unix domain socket
3145 @var{path} is used for connections.
3147 @item mon:@var{dev_string}
3148 This is a special option to allow the monitor to be multiplexed onto
3149 another serial port. The monitor is accessed with key sequence of
3150 @key{Control-a} and then pressing @key{c}.
3151 @var{dev_string} should be any one of the serial devices specified
3152 above. An example to multiplex the monitor onto a telnet server
3153 listening on port 4444 would be:
3155 @item -serial mon:telnet::4444,server,nowait
3157 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3158 QEMU any more but will be passed to the guest instead.
3161 Braille device. This will use BrlAPI to display the braille output on a real
3165 Three button serial mouse. Configure the guest to use Microsoft protocol.
3169 DEF("parallel
", HAS_ARG, QEMU_OPTION_parallel, \
3170 "-parallel dev redirect the parallel port to char device
'dev'\n",
3173 @item -parallel @var{dev}
3175 Redirect the virtual parallel port to host device @var{dev} (same
3176 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3177 be used to use hardware devices connected on the corresponding host
3180 This option can be used several times to simulate up to 3 parallel
3183 Use @code{-parallel none} to disable all parallel ports.
3186 DEF("monitor
", HAS_ARG, QEMU_OPTION_monitor, \
3187 "-monitor dev redirect the monitor to char device
'dev'\n",
3190 @item -monitor @var{dev}
3192 Redirect the monitor to host device @var{dev} (same devices as the
3194 The default device is @code{vc} in graphical mode and @code{stdio} in
3196 Use @code{-monitor none} to disable the default monitor.
3198 DEF("qmp
", HAS_ARG, QEMU_OPTION_qmp, \
3199 "-qmp dev like
-monitor but opens
in 'control' mode
\n",
3202 @item -qmp @var{dev}
3204 Like -monitor but opens in 'control' mode.
3206 DEF("qmp
-pretty
", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3207 "-qmp
-pretty dev like
-qmp but uses pretty JSON formatting
\n",
3210 @item -qmp-pretty @var{dev}
3212 Like -qmp but uses pretty JSON formatting.
3215 DEF("mon
", HAS_ARG, QEMU_OPTION_mon, \
3216 "-mon
[chardev
=]name
[,mode
=readline|control
][,pretty
[=on|off
]]\n", QEMU_ARCH_ALL)
3218 @item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3220 Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3221 easing human reading and debugging.
3224 DEF("debugcon
", HAS_ARG, QEMU_OPTION_debugcon, \
3225 "-debugcon dev redirect the debug console to char device
'dev'\n",
3228 @item -debugcon @var{dev}
3230 Redirect the debug console to host device @var{dev} (same devices as the
3231 serial port). The debug console is an I/O port which is typically port
3232 0xe9; writing to that I/O port sends output to this device.
3233 The default device is @code{vc} in graphical mode and @code{stdio} in
3237 DEF("pidfile
", HAS_ARG, QEMU_OPTION_pidfile, \
3238 "-pidfile file write PID to
'file'\n", QEMU_ARCH_ALL)
3240 @item -pidfile @var{file}
3242 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3246 DEF("singlestep
", 0, QEMU_OPTION_singlestep, \
3247 "-singlestep always run
in singlestep mode
\n", QEMU_ARCH_ALL)
3251 Run the emulation in single step mode.
3254 DEF("preconfig
", 0, QEMU_OPTION_preconfig, \
3255 "--preconfig pause QEMU before machine is
initialized (experimental
)\n",
3260 Pause QEMU for interactive configuration before the machine is created,
3261 which allows querying and configuring properties that will affect
3262 machine initialization. Use QMP command 'x-exit-preconfig' to exit
3263 the preconfig state and move to the next state (i.e. run guest if -S
3264 isn't used or pause the second time if -S is used). This option is
3268 DEF("S
", 0, QEMU_OPTION_S, \
3269 "-S freeze CPU at
startup (use
'c' to start execution
)\n",
3274 Do not start CPU at startup (you must type 'c' in the monitor).
3277 DEF("realtime
", HAS_ARG, QEMU_OPTION_realtime,
3278 "-realtime
[mlock
=on|off
]\n"
3279 " run qemu with realtime features
\n"
3280 " mlock
=on|off controls mlock
support (default: on
)\n",
3283 @item -realtime mlock=on|off
3285 Run qemu with realtime features.
3286 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3287 (enabled by default).
3290 DEF("overcommit
", HAS_ARG, QEMU_OPTION_overcommit,
3291 "-overcommit
[mem
-lock
=on|off
][cpu
-pm
=on|off
]\n"
3292 " run qemu with overcommit hints
\n"
3293 " mem
-lock
=on|off controls memory lock
support (default: off
)\n"
3294 " cpu
-pm
=on|off controls cpu power
management (default: off
)\n",
3297 @item -overcommit mem-lock=on|off
3298 @item -overcommit cpu-pm=on|off
3300 Run qemu with hints about host resource overcommit. The default is
3301 to assume that host overcommits all resources.
3303 Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled
3304 by default). This works when host memory is not overcommitted and reduces the
3305 worst-case latency for guest. This is equivalent to @option{realtime}.
3307 Guest ability to manage power state of host cpus (increasing latency for other
3308 processes on the same host cpu, but decreasing latency for guest) can be
3309 enabled via @option{cpu-pm=on} (disabled by default). This works best when
3310 host CPU is not overcommitted. When used, host estimates of CPU cycle and power
3311 utilization will be incorrect, not taking into account guest idle time.
3314 DEF("gdb
", HAS_ARG, QEMU_OPTION_gdb, \
3315 "-gdb dev wait
for gdb connection on
'dev'\n", QEMU_ARCH_ALL)
3317 @item -gdb @var{dev}
3319 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3320 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3321 stdio are reasonable use case. The latter is allowing to start QEMU from
3322 within gdb and establish the connection via a pipe:
3324 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3328 DEF("s
", 0, QEMU_OPTION_s, \
3329 "-s shorthand
for -gdb tcp
::" DEFAULT_GDBSTUB_PORT "\n",
3334 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3335 (@pxref{gdb_usage}).
3338 DEF("d
", HAS_ARG, QEMU_OPTION_d, \
3339 "-d item1
,... enable logging of specified
items (use
'-d help' for a list of log items
)\n",
3342 @item -d @var{item1}[,...]
3344 Enable logging of specified items. Use '-d help' for a list of log items.
3347 DEF("D
", HAS_ARG, QEMU_OPTION_D, \
3348 "-D logfile output log to
logfile (default stderr
)\n",
3351 @item -D @var{logfile}
3353 Output log in @var{logfile} instead of to stderr
3356 DEF("dfilter
", HAS_ARG, QEMU_OPTION_DFILTER, \
3357 "-dfilter range
,.. filter debug output to range of
addresses (useful
for -d cpu
,exec
,etc
..)\n",
3360 @item -dfilter @var{range1}[,...]
3362 Filter debug output to that relevant to a range of target addresses. The filter
3363 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3364 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3365 addresses and sizes required. For example:
3367 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3369 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3370 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3371 block starting at 0xffffffc00005f000.
3374 DEF("L
", HAS_ARG, QEMU_OPTION_L, \
3375 "-L path set the directory
for the BIOS
, VGA BIOS and keymaps
\n",
3380 Set the directory for the BIOS, VGA BIOS and keymaps.
3382 To list all the data directories, use @code{-L help}.
3385 DEF("bios
", HAS_ARG, QEMU_OPTION_bios, \
3386 "-bios file set the filename
for the BIOS
\n", QEMU_ARCH_ALL)
3388 @item -bios @var{file}
3390 Set the filename for the BIOS.
3393 DEF("enable
-kvm
", 0, QEMU_OPTION_enable_kvm, \
3394 "-enable
-kvm enable KVM full virtualization support
\n", QEMU_ARCH_ALL)
3398 Enable KVM full virtualization support. This option is only available
3399 if KVM support is enabled when compiling.
3402 DEF("xen
-domid
", HAS_ARG, QEMU_OPTION_xen_domid,
3403 "-xen
-domid id specify xen guest domain id
\n", QEMU_ARCH_ALL)
3404 DEF("xen
-attach
", 0, QEMU_OPTION_xen_attach,
3405 "-xen
-attach attach to existing xen domain
\n"
3406 " libxl will use
this when starting QEMU
\n",
3408 DEF("xen
-domid
-restrict
", 0, QEMU_OPTION_xen_domid_restrict,
3409 "-xen
-domid
-restrict restrict set of available xen operations
\n"
3410 " to specified domain id
. (Does not affect
\n"
3411 " xenpv machine type
).\n",
3414 @item -xen-domid @var{id}
3416 Specify xen guest domain @var{id} (XEN only).
3419 Attach to existing xen domain.
3420 libxl will use this when starting QEMU (XEN only).
3421 @findex -xen-domid-restrict
3422 Restrict set of available xen operations to specified domain id (XEN only).
3425 DEF("no
-reboot
", 0, QEMU_OPTION_no_reboot, \
3426 "-no
-reboot exit instead of rebooting
\n", QEMU_ARCH_ALL)
3430 Exit instead of rebooting.
3433 DEF("no
-shutdown
", 0, QEMU_OPTION_no_shutdown, \
3434 "-no
-shutdown stop before shutdown
\n", QEMU_ARCH_ALL)
3437 @findex -no-shutdown
3438 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3439 This allows for instance switching to monitor to commit changes to the
3443 DEF("loadvm
", HAS_ARG, QEMU_OPTION_loadvm, \
3444 "-loadvm
[tag|id
]\n" \
3445 " start right away with a saved
state (loadvm
in monitor
)\n",
3448 @item -loadvm @var{file}
3450 Start right away with a saved state (@code{loadvm} in monitor)
3454 DEF("daemonize
", 0, QEMU_OPTION_daemonize, \
3455 "-daemonize daemonize QEMU after initializing
\n", QEMU_ARCH_ALL)
3460 Daemonize the QEMU process after initialization. QEMU will not detach from
3461 standard IO until it is ready to receive connections on any of its devices.
3462 This option is a useful way for external programs to launch QEMU without having
3463 to cope with initialization race conditions.
3466 DEF("option
-rom
", HAS_ARG, QEMU_OPTION_option_rom, \
3467 "-option
-rom rom load a file
, rom
, into the option ROM space
\n",
3470 @item -option-rom @var{file}
3472 Load the contents of @var{file} as an option ROM.
3473 This option is useful to load things like EtherBoot.
3476 DEF("rtc
", HAS_ARG, QEMU_OPTION_rtc, \
3477 "-rtc
[base
=utc|localtime|
<datetime
>][,clock
=host|rt|vm
][,driftfix
=none|slew
]\n" \
3478 " set the RTC base and clock
, enable drift fix
for clock
ticks (x86 only
)\n",
3483 @item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew]
3485 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3486 UTC or local time, respectively. @code{localtime} is required for correct date in
3487 MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the
3488 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3490 By default the RTC is driven by the host system time. This allows using of the
3491 RTC as accurate reference clock inside the guest, specifically if the host
3492 time is smoothly following an accurate external reference clock, e.g. via NTP.
3493 If you want to isolate the guest time from the host, you can set @option{clock}
3494 to @code{rt} instead, which provides a host monotonic clock if host support it.
3495 To even prevent the RTC from progressing during suspension, you can set @option{clock}
3496 to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in
3497 icount mode in order to preserve determinism; however, note that in icount mode
3498 the speed of the virtual clock is variable and can in general differ from the
3501 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3502 specifically with Windows' ACPI HAL. This option will try to figure out how
3503 many timer interrupts were not processed by the Windows guest and will
3507 DEF("icount
", HAS_ARG, QEMU_OPTION_icount, \
3508 "-icount
[shift
=N|auto
][,align
=on|off
][,sleep
=on|off
,rr
=record|replay
,rrfile
=<filename
>,rrsnapshot
=<snapshot
>]\n" \
3509 " enable virtual instruction counter with
2^N clock ticks per
\n" \
3510 " instruction
, enable aligning the host and virtual clocks
\n" \
3511 " or disable real time cpu sleeping
\n", QEMU_ARCH_ALL)
3513 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3515 Enable virtual instruction counter. The virtual cpu will execute one
3516 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3517 then the virtual cpu speed will be automatically adjusted to keep virtual
3518 time within a few seconds of real time.
3520 When the virtual cpu is sleeping, the virtual time will advance at default
3521 speed unless @option{sleep=on|off} is specified.
3522 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3523 instantly whenever the virtual cpu goes to sleep mode and will not advance
3524 if no timer is enabled. This behavior give deterministic execution times from
3525 the guest point of view.
3527 Note that while this option can give deterministic behavior, it does not
3528 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3529 order cores with complex cache hierarchies. The number of instructions
3530 executed often has little or no correlation with actual performance.
3532 @option{align=on} will activate the delay algorithm which will try
3533 to synchronise the host clock and the virtual clock. The goal is to
3534 have a guest running at the real frequency imposed by the shift option.
3535 Whenever the guest clock is behind the host clock and if
3536 @option{align=on} is specified then we print a message to the user
3537 to inform about the delay.
3538 Currently this option does not work when @option{shift} is @code{auto}.
3539 Note: The sync algorithm will work for those shift values for which
3540 the guest clock runs ahead of the host clock. Typically this happens
3541 when the shift value is high (how high depends on the host machine).
3543 When @option{rr} option is specified deterministic record/replay is enabled.
3544 Replay log is written into @var{filename} file in record mode and
3545 read from this file in replay mode.
3547 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3548 at the start of execution recording. In replay mode this option is used
3549 to load the initial VM state.
3552 DEF("watchdog
", HAS_ARG, QEMU_OPTION_watchdog, \
3553 "-watchdog model
\n" \
3554 " enable virtual hardware watchdog
[default=none
]\n",
3557 @item -watchdog @var{model}
3559 Create a virtual hardware watchdog device. Once enabled (by a guest
3560 action), the watchdog must be periodically polled by an agent inside
3561 the guest or else the guest will be restarted. Choose a model for
3562 which your guest has drivers.
3564 The @var{model} is the model of hardware watchdog to emulate. Use
3565 @code{-watchdog help} to list available hardware models. Only one
3566 watchdog can be enabled for a guest.
3568 The following models may be available:
3571 iBASE 700 is a very simple ISA watchdog with a single timer.
3573 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3574 dual-timer watchdog.
3576 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3577 (currently KVM only).
3581 DEF("watchdog
-action
", HAS_ARG, QEMU_OPTION_watchdog_action, \
3582 "-watchdog
-action reset|shutdown|poweroff|inject
-nmi|pause|debug|none
\n" \
3583 " action when watchdog fires
[default=reset
]\n",
3586 @item -watchdog-action @var{action}
3587 @findex -watchdog-action
3589 The @var{action} controls what QEMU will do when the watchdog timer
3592 @code{reset} (forcefully reset the guest).
3593 Other possible actions are:
3594 @code{shutdown} (attempt to gracefully shutdown the guest),
3595 @code{poweroff} (forcefully poweroff the guest),
3596 @code{inject-nmi} (inject a NMI into the guest),
3597 @code{pause} (pause the guest),
3598 @code{debug} (print a debug message and continue), or
3599 @code{none} (do nothing).
3601 Note that the @code{shutdown} action requires that the guest responds
3602 to ACPI signals, which it may not be able to do in the sort of
3603 situations where the watchdog would have expired, and thus
3604 @code{-watchdog-action shutdown} is not recommended for production use.
3609 @item -watchdog i6300esb -watchdog-action pause
3610 @itemx -watchdog ib700
3614 DEF("echr
", HAS_ARG, QEMU_OPTION_echr, \
3615 "-echr chr set terminal escape character instead of ctrl
-a
\n",
3619 @item -echr @var{numeric_ascii_value}
3621 Change the escape character used for switching to the monitor when using
3622 monitor and serial sharing. The default is @code{0x01} when using the
3623 @code{-nographic} option. @code{0x01} is equal to pressing
3624 @code{Control-a}. You can select a different character from the ascii
3625 control keys where 1 through 26 map to Control-a through Control-z. For
3626 instance you could use the either of the following to change the escape
3627 character to Control-t.
3634 DEF("show
-cursor
", 0, QEMU_OPTION_show_cursor, \
3635 "-show
-cursor show cursor
\n", QEMU_ARCH_ALL)
3638 @findex -show-cursor
3642 DEF("tb
-size
", HAS_ARG, QEMU_OPTION_tb_size, \
3643 "-tb
-size n set TB size
\n", QEMU_ARCH_ALL)
3645 @item -tb-size @var{n}
3650 DEF("incoming
", HAS_ARG, QEMU_OPTION_incoming, \
3651 "-incoming tcp
:[host
]:port
[,to
=maxport
][,ipv4
][,ipv6
]\n" \
3652 "-incoming rdma
:host
:port
[,ipv4
][,ipv6
]\n" \
3653 "-incoming unix
:socketpath
\n" \
3654 " prepare
for incoming migration
, listen on
\n" \
3655 " specified protocol and socket address
\n" \
3656 "-incoming fd
:fd
\n" \
3657 "-incoming exec
:cmdline
\n" \
3658 " accept incoming migration on given file descriptor
\n" \
3659 " or from given external command
\n" \
3660 "-incoming defer
\n" \
3661 " wait
for the URI to be specified via migrate_incoming
\n",
3664 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3665 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3667 Prepare for incoming migration, listen on a given tcp port.
3669 @item -incoming unix:@var{socketpath}
3670 Prepare for incoming migration, listen on a given unix socket.
3672 @item -incoming fd:@var{fd}
3673 Accept incoming migration from a given filedescriptor.
3675 @item -incoming exec:@var{cmdline}
3676 Accept incoming migration as an output from specified external command.
3678 @item -incoming defer
3679 Wait for the URI to be specified via migrate_incoming. The monitor can
3680 be used to change settings (such as migration parameters) prior to issuing
3681 the migrate_incoming to allow the migration to begin.
3684 DEF("only
-migratable
", 0, QEMU_OPTION_only_migratable, \
3685 "-only
-migratable allow only migratable devices
\n", QEMU_ARCH_ALL)
3687 @item -only-migratable
3688 @findex -only-migratable
3689 Only allow migratable devices. Devices will not be allowed to enter an
3693 DEF("nodefaults
", 0, QEMU_OPTION_nodefaults, \
3694 "-nodefaults don
't create default devices\n", QEMU_ARCH_ALL)
3698 Don't create
default devices
. Normally
, QEMU sets the
default devices like serial
3699 port
, parallel port
, virtual console
, monitor device
, VGA adapter
, floppy and
3700 CD
-ROM drive and others
. The @code
{-nodefaults
} option will disable all those
3705 DEF("chroot", HAS_ARG
, QEMU_OPTION_chroot
, \
3706 "-chroot dir chroot to dir just before starting the VM\n",
3710 @item
-chroot @
var{dir
}
3712 Immediately before starting guest execution
, chroot to the specified
3713 directory
. Especially useful
in combination with
-runas
.
3717 DEF("runas", HAS_ARG
, QEMU_OPTION_runas
, \
3718 "-runas user change to user id user just before starting the VM\n" \
3719 " user can be numeric uid:gid instead\n",
3723 @item
-runas @
var{user
}
3725 Immediately before starting guest execution
, drop root privileges
, switching
3726 to the specified user
.
3729 DEF("prom-env", HAS_ARG
, QEMU_OPTION_prom_env
,
3730 "-prom-env variable=value\n"
3731 " set OpenBIOS nvram variables\n",
3732 QEMU_ARCH_PPC | QEMU_ARCH_SPARC
)
3734 @item
-prom
-env @
var{variable
}=@
var{value
}
3736 Set OpenBIOS nvram @
var{variable
} to given @
var{value
} (PPC
, SPARC only
).
3738 DEF("semihosting", 0, QEMU_OPTION_semihosting
,
3739 "-semihosting semihosting mode\n",
3740 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3744 @findex
-semihosting
3745 Enable semihosting
mode (ARM
, M68K
, Xtensa
, MIPS only
).
3747 DEF("semihosting-config", HAS_ARG
, QEMU_OPTION_semihosting_config
,
3748 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3749 " semihosting configuration\n",
3750 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3753 @item
-semihosting
-config
[enable
=on|off
][,target
=native|gdb|auto
][,arg
=str
[,...]]
3754 @findex
-semihosting
-config
3755 Enable and configure
semihosting (ARM
, M68K
, Xtensa
, MIPS only
).
3757 @item target
=@code
{native|gdb|auto
}
3758 Defines where the semihosting calls will be addressed
, to
QEMU (@code
{native
})
3759 or to
GDB (@code
{gdb
}). The
default is @code
{auto
}, which means @code
{gdb
}
3760 during debug sessions and @code
{native
} otherwise
.
3761 @item arg
=@
var{str1
},arg
=@
var{str2
},...
3762 Allows the user to pass input arguments
, and can be used multiple times to build
3763 up a list
. The old
-style @code
{-kernel
}/@code
{-append
} method of passing a
3764 command line is still supported
for backward compatibility
. If both the
3765 @code
{--semihosting
-config arg
} and the @code
{-kernel
}/@code
{-append
} are
3766 specified
, the former is passed to semihosting as it always takes precedence
.
3769 DEF("old-param", 0, QEMU_OPTION_old_param
,
3770 "-old-param old param mode\n", QEMU_ARCH_ARM
)
3773 @findex
-old
-param (ARM
)
3774 Old param
mode (ARM only
).
3777 DEF("sandbox", HAS_ARG
, QEMU_OPTION_sandbox
, \
3778 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3779 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3780 " Enable seccomp mode 2 system call filter (default 'off').\n" \
3781 " use 'obsolete' to allow obsolete system calls that are provided\n" \
3782 " by the kernel, but typically no longer used by modern\n" \
3783 " C library implementations.\n" \
3784 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3785 " its privileges by blacklisting all set*uid|gid system calls.\n" \
3786 " The value 'children' will deny set*uid|gid system calls for\n" \
3787 " main QEMU process but will allow forks and execves to run unprivileged\n" \
3788 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3789 " blacklisting *fork and execve\n" \
3790 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
3793 @item
-sandbox @
var{arg
}[,obsolete
=@
var{string
}][,elevateprivileges
=@
var{string
}][,spawn
=@
var{string
}][,resourcecontrol
=@
var{string
}]
3795 Enable Seccomp mode
2 system call filter
. 'on' will enable syscall filtering and
'off' will
3796 disable it
. The
default is
'off'.
3798 @item obsolete
=@
var{string
}
3799 Enable Obsolete system calls
3800 @item elevateprivileges
=@
var{string
}
3801 Disable set
*uid|gid system calls
3802 @item spawn
=@
var{string
}
3803 Disable
*fork and execve
3804 @item resourcecontrol
=@
var{string
}
3805 Disable process affinity and schedular priority
3809 DEF("readconfig", HAS_ARG
, QEMU_OPTION_readconfig
,
3810 "-readconfig <file>\n", QEMU_ARCH_ALL
)
3812 @item
-readconfig @
var{file
}
3814 Read device configuration from @
var{file
}. This approach is useful when you want to spawn
3815 QEMU process with many command line options but you don
't want to exceed the command line
3818 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3819 "-writeconfig <file>\n"
3820 " read/write config file\n", QEMU_ARCH_ALL)
3822 @item -writeconfig @var{file}
3823 @findex -writeconfig
3824 Write device configuration to @var{file}. The @var{file} can be either filename to save
3825 command line and device configuration into file or dash @code{-}) character to print the
3826 output to stdout. This can be later used as input file for @code{-readconfig} option.
3829 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3831 " do not load default user-provided config files at startup\n",
3834 @item -no-user-config
3835 @findex -no-user-config
3836 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3837 config files on @var{sysconfdir}.
3840 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3841 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3842 " specify tracing options\n",
3845 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3846 HXCOMM HX does not support conditional compilation of text.
3847 @item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3849 @include qemu-option-trace.texi
3853 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3854 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3857 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3858 "-enable-fips enable FIPS 140-2 compliance\n",
3863 @findex -enable-fips
3864 Enable FIPS 140-2 compliance mode.
3867 HXCOMM Deprecated by -machine accel=tcg property
3868 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3870 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3871 "-msg timestamp[=on|off]\n"
3872 " change the format of messages\n"
3873 " on|off controls leading timestamps (default:on)\n",
3876 @item -msg timestamp[=on|off]
3878 prepend a timestamp to each log message.(default:on)
3881 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3882 "-dump-vmstate <file>\n"
3883 " Output vmstate information in JSON format to file.\n"
3884 " Use the scripts/vmstate-static-checker.py file to\n"
3885 " check for possible regressions in migration code\n"
3886 " by comparing two such vmstate dumps.\n",
3889 @item -dump-vmstate @var{file}
3890 @findex -dump-vmstate
3891 Dump json-encoded vmstate information for current machine type to file
3895 DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
3896 "-enable-sync-profile\n"
3897 " enable synchronization profiling\n",
3900 @item -enable-sync-profile
3901 @findex -enable-sync-profile
3902 Enable synchronization profiling.
3910 DEFHEADING(Generic object creation:)
3915 DEF("object", HAS_ARG, QEMU_OPTION_object,
3916 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3917 " create a new object of type TYPENAME setting properties\n"
3918 " in the order they are specified. Note that the 'id
'\n"
3919 " property must be set. These objects are placed in the\n"
3920 " '/objects
' path.\n",
3923 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3925 Create a new object of type @var{typename} setting properties
3926 in the order they are specified. Note that the 'id
'
3927 property must be set. These objects are placed in the
3932 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},align=@var{align}
3934 Creates a memory file backend object, which can be used to back
3935 the guest RAM with huge pages.
3937 The @option{id} parameter is a unique ID that will be used to reference this
3938 memory region when configuring the @option{-numa} argument.
3940 The @option{size} option provides the size of the memory region, and accepts
3941 common suffixes, eg @option{500M}.
3943 The @option{mem-path} provides the path to either a shared memory or huge page
3946 The @option{share} boolean option determines whether the memory
3947 region is marked as private to QEMU, or shared. The latter allows
3948 a co-operating external process to access the QEMU memory region.
3950 The @option{share} is also required for pvrdma devices due to
3951 limitations in the RDMA API provided by Linux.
3953 Setting share=on might affect the ability to configure NUMA
3954 bindings for the memory backend under some circumstances, see
3955 Documentation/vm/numa_memory_policy.txt on the Linux kernel
3956 source tree for additional details.
3958 Setting the @option{discard-data} boolean option to @var{on}
3959 indicates that file contents can be destroyed when QEMU exits,
3960 to avoid unnecessarily flushing data to the backing file. Note
3961 that @option{discard-data} is only an optimization, and QEMU
3962 might not discard file contents if it aborts unexpectedly or is
3963 terminated using SIGKILL.
3965 The @option{merge} boolean option enables memory merge, also known as
3966 MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
3967 memory deduplication.
3969 Setting the @option{dump} boolean option to @var{off} excludes the memory from
3970 core dumps. This feature is also known as MADV_DONTDUMP.
3972 The @option{prealloc} boolean option enables memory preallocation.
3974 The @option{host-nodes} option binds the memory range to a list of NUMA host
3977 The @option{policy} option sets the NUMA policy to one of the following values:
3983 @item @var{preferred}
3984 prefer the given host node list for allocation
3987 restrict memory allocation to the given host node list
3989 @item @var{interleave}
3990 interleave memory allocations across the given host node list
3993 The @option{align} option specifies the base address alignment when
3994 QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
3995 @option{2M}. Some backend store specified by @option{mem-path}
3996 requires an alignment different than the default one used by QEMU, eg
3997 the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
3998 such cases, users can specify the required alignment via this option.
4000 The @option{pmem} option specifies whether the backing file specified
4001 by @option{mem-path} is in host persistent memory that can be accessed
4002 using the SNIA NVM programming model (e.g. Intel NVDIMM).
4003 If @option{pmem} is set to 'on
', QEMU will take necessary operations to
4004 guarantee the persistence of its own writes to @option{mem-path}
4005 (e.g. in vNVDIMM label emulation and live migration).
4007 @item -object memory-backend-ram,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave}
4009 Creates a memory backend object, which can be used to back the guest RAM.
4010 Memory backend objects offer more control than the @option{-m} option that is
4011 traditionally used to define guest RAM. Please refer to
4012 @option{memory-backend-file} for a description of the options.
4014 @item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},seal=@var{on|off},hugetlb=@var{on|off},hugetlbsize=@var{size}
4016 Creates an anonymous memory file backend object, which allows QEMU to
4017 share the memory with an external process (e.g. when using
4018 vhost-user). The memory is allocated with memfd and optional
4019 sealing. (Linux only)
4021 The @option{seal} option creates a sealed-file, that will block
4022 further resizing the memory ('on
' by default).
4024 The @option{hugetlb} option specify the file to be created resides in
4025 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with
4026 the @option{hugetlb} option, the @option{hugetlbsize} option specify
4027 the hugetlb page size on systems that support multiple hugetlb page
4028 sizes (it must be a power of 2 value supported by the system).
4030 In some versions of Linux, the @option{hugetlb} option is incompatible
4031 with the @option{seal} option (requires at least Linux 4.16).
4033 Please refer to @option{memory-backend-file} for a description of the
4036 The @option{share} boolean option is @var{on} by default with memfd.
4038 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
4040 Creates a random number generator backend which obtains entropy from
4041 a device on the host. The @option{id} parameter is a unique ID that
4042 will be used to reference this entropy backend from the @option{virtio-rng}
4043 device. The @option{filename} parameter specifies which file to obtain
4044 entropy from and if omitted defaults to @option{/dev/random}.
4046 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4048 Creates a random number generator backend which obtains entropy from
4049 an external daemon running on the host. The @option{id} parameter is
4050 a unique ID that will be used to reference this entropy backend from
4051 the @option{virtio-rng} device. The @option{chardev} parameter is
4052 the unique ID of a character device backend that provides the connection
4055 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4057 Creates a TLS anonymous credentials object, which can be used to provide
4058 TLS support on network backends. The @option{id} parameter is a unique
4059 ID which network backends will use to access the credentials. The
4060 @option{endpoint} is either @option{server} or @option{client} depending
4061 on whether the QEMU network backend that uses the credentials will be
4062 acting as a client or as a server. If @option{verify-peer} is enabled
4063 (the default) then once the handshake is completed, the peer credentials
4064 will be verified, though this is a no-op for anonymous credentials.
4066 The @var{dir} parameter tells QEMU where to find the credential
4067 files. For server endpoints, this directory may contain a file
4068 @var{dh-params.pem} providing diffie-hellman parameters to use
4069 for the TLS server. If the file is missing, QEMU will generate
4070 a set of DH parameters at startup. This is a computationally
4071 expensive operation that consumes random pool entropy, so it is
4072 recommended that a persistent set of parameters be generated
4075 @item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}]
4077 Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide
4078 TLS support on network backends. The @option{id} parameter is a unique
4079 ID which network backends will use to access the credentials. The
4080 @option{endpoint} is either @option{server} or @option{client} depending
4081 on whether the QEMU network backend that uses the credentials will be
4082 acting as a client or as a server. For clients only, @option{username}
4083 is the username which will be sent to the server. If omitted
4084 it defaults to ``qemu''.
4086 The @var{dir} parameter tells QEMU where to find the keys file.
4087 It is called ``@var{dir}/keys.psk'' and contains ``username:key''
4088 pairs. This file can most easily be created using the GnuTLS
4089 @code{psktool} program.
4091 For server endpoints, @var{dir} may also contain a file
4092 @var{dh-params.pem} providing diffie-hellman parameters to use
4093 for the TLS server. If the file is missing, QEMU will generate
4094 a set of DH parameters at startup. This is a computationally
4095 expensive operation that consumes random pool entropy, so it is
4096 recommended that a persistent set of parameters be generated
4099 @item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},priority=@var{priority},verify-peer=@var{on|off},passwordid=@var{id}
4101 Creates a TLS anonymous credentials object, which can be used to provide
4102 TLS support on network backends. The @option{id} parameter is a unique
4103 ID which network backends will use to access the credentials. The
4104 @option{endpoint} is either @option{server} or @option{client} depending
4105 on whether the QEMU network backend that uses the credentials will be
4106 acting as a client or as a server. If @option{verify-peer} is enabled
4107 (the default) then once the handshake is completed, the peer credentials
4108 will be verified. With x509 certificates, this implies that the clients
4109 must be provided with valid client certificates too.
4111 The @var{dir} parameter tells QEMU where to find the credential
4112 files. For server endpoints, this directory may contain a file
4113 @var{dh-params.pem} providing diffie-hellman parameters to use
4114 for the TLS server. If the file is missing, QEMU will generate
4115 a set of DH parameters at startup. This is a computationally
4116 expensive operation that consumes random pool entropy, so it is
4117 recommended that a persistent set of parameters be generated
4120 For x509 certificate credentials the directory will contain further files
4121 providing the x509 certificates. The certificates must be stored
4122 in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4123 @var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4124 @var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4126 For the @var{server-key.pem} and @var{client-key.pem} files which
4127 contain sensitive private keys, it is possible to use an encrypted
4128 version by providing the @var{passwordid} parameter. This provides
4129 the ID of a previously created @code{secret} object containing the
4130 password for decryption.
4132 The @var{priority} parameter allows to override the global default
4133 priority used by gnutls. This can be useful if the system administrator
4134 needs to use a weaker set of crypto priorities for QEMU without
4135 potentially forcing the weakness onto all applications. Or conversely
4136 if one wants wants a stronger default for QEMU than for all other
4137 applications, they can do this through this parameter. Its format is
4138 a gnutls priority string as described at
4139 @url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4141 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4143 Interval @var{t} can't be
0, this filter batches the packet delivery
: all
4144 packets arriving
in a given interval on netdev @
var{netdevid
} are delayed
4145 until the end of the interval
. Interval is
in microseconds
.
4146 @option
{status
} is optional that indicate whether the netfilter is
4147 on (enabled
) or
off (disabled
), the
default status
for netfilter will be
'on'.
4149 queue @
var{all|rx|tx
} is an option that can be applied to any netfilter
.
4151 @option
{all
}: the filter is attached both to the receive and the transmit
4152 queue of the
netdev (default).
4154 @option
{rx
}: the filter is attached to the receive queue of the netdev
,
4155 where it will receive packets sent to the netdev
.
4157 @option
{tx
}: the filter is attached to the transmit queue of the netdev
,
4158 where it will receive packets sent by the netdev
.
4160 @item
-object filter
-mirror
,id
=@
var{id
},netdev
=@
var{netdevid
},outdev
=@
var{chardevid
},queue
=@
var{all|rx|tx
}[,vnet_hdr_support
]
4162 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
.
4164 @item
-object filter
-redirector
,id
=@
var{id
},netdev
=@
var{netdevid
},indev
=@
var{chardevid
},outdev
=@
var{chardevid
},queue
=@
var{all|rx|tx
}[,vnet_hdr_support
]
4166 filter
-redirector on netdev @
var{netdevid
},redirect filter
's net packet to chardev
4167 @var{chardevid},and redirect indev's packet to filter
.if it has the vnet_hdr_support flag
,
4168 filter
-redirector will redirect packet with vnet_hdr_len
.
4169 Create a filter
-redirector we need to differ outdev id from indev id
, id can not
4170 be the same
. we can just use indev or outdev
, but at least one of indev or outdev
4171 need to be specified
.
4173 @item
-object filter
-rewriter
,id
=@
var{id
},netdev
=@
var{netdevid
},queue
=@
var{all|rx|tx
},[vnet_hdr_support
]
4175 Filter
-rewriter is a part of COLO project
.It will rewrite tcp packet to
4176 secondary from primary to keep secondary tcp connection
,and rewrite
4177 tcp packet to primary from secondary make tcp packet can be handled by
4178 client
.if it has the vnet_hdr_support flag
, we can parse packet with vnet header
.
4182 -object filter
-redirector
,id
=f1
,netdev
=hn0
,queue
=tx
,indev
=red0
4183 -object filter
-redirector
,id
=f2
,netdev
=hn0
,queue
=rx
,outdev
=red1
4184 -object filter
-rewriter
,id
=rew0
,netdev
=hn0
,queue
=all
4186 @item
-object filter
-dump
,id
=@
var{id
},netdev
=@
var{dev
}[,file
=@
var{filename
}][,maxlen
=@
var{len
}]
4188 Dump the network traffic on netdev @
var{dev
} to the file specified by
4189 @
var{filename
}. At most @
var{len
} bytes (64k by
default) per packet are stored
.
4190 The file format is libpcap
, so it can be analyzed with tools such as tcpdump
4193 @item
-object colo
-compare
,id
=@
var{id
},primary_in
=@
var{chardevid
},secondary_in
=@
var{chardevid
},outdev
=@
var{chardevid
}[,vnet_hdr_support
]
4195 Colo
-compare gets packet from primary_in@
var{chardevid
} and secondary_in@
var{chardevid
}, than compare primary packet with
4196 secondary packet
. If the packets are same
, we will output primary
4197 packet to outdev@
var{chardevid
}, else we will notify colo
-frame
4198 do checkpoint and send primary packet to outdev@
var{chardevid
}.
4199 if it has the vnet_hdr_support flag
, colo compare will send
/recv packet with vnet_hdr_len
.
4201 we must use it with the help of filter
-mirror and filter
-redirector
.
4206 -netdev tap
,id
=hn0
,vhost
=off
,script
=/etc
/qemu
-ifup
,downscript
=/etc
/qemu
-ifdown
4207 -device e1000
,id
=e0
,netdev
=hn0
,mac
=52:a4
:00:12:78:66
4208 -chardev socket
,id
=mirror0
,host
=3.3.3.3,port
=9003,server
,nowait
4209 -chardev socket
,id
=compare1
,host
=3.3.3.3,port
=9004,server
,nowait
4210 -chardev socket
,id
=compare0
,host
=3.3.3.3,port
=9001,server
,nowait
4211 -chardev socket
,id
=compare0
-0,host
=3.3.3.3,port
=9001
4212 -chardev socket
,id
=compare_out
,host
=3.3.3.3,port
=9005,server
,nowait
4213 -chardev socket
,id
=compare_out0
,host
=3.3.3.3,port
=9005
4214 -object filter
-mirror
,id
=m0
,netdev
=hn0
,queue
=tx
,outdev
=mirror0
4215 -object filter
-redirector
,netdev
=hn0
,id
=redire0
,queue
=rx
,indev
=compare_out
4216 -object filter
-redirector
,netdev
=hn0
,id
=redire1
,queue
=rx
,outdev
=compare0
4217 -object colo
-compare
,id
=comp0
,primary_in
=compare0
-0,secondary_in
=compare1
,outdev
=compare_out0
4220 -netdev tap
,id
=hn0
,vhost
=off
,script
=/etc
/qemu
-ifup
,down script
=/etc
/qemu
-ifdown
4221 -device e1000
,netdev
=hn0
,mac
=52:a4
:00:12:78:66
4222 -chardev socket
,id
=red0
,host
=3.3.3.3,port
=9003
4223 -chardev socket
,id
=red1
,host
=3.3.3.3,port
=9004
4224 -object filter
-redirector
,id
=f1
,netdev
=hn0
,queue
=tx
,indev
=red0
4225 -object filter
-redirector
,id
=f2
,netdev
=hn0
,queue
=rx
,outdev
=red1
4229 If you want to know the detail of above command line
, you can read
4230 the colo
-compare git log
.
4232 @item
-object cryptodev
-backend
-builtin
,id
=@
var{id
}[,queues
=@
var{queues
}]
4234 Creates a cryptodev backend which executes crypto opreation from
4235 the QEMU cipher APIS
. The @
var{id
} parameter is
4236 a unique ID that will be used to reference
this cryptodev backend from
4237 the @option
{virtio
-crypto
} device
. The @
var{queues
} parameter is optional
,
4238 which specify the queue number of cryptodev backend
, the
default of
4243 # qemu
-system
-x86_64 \
4245 -object cryptodev
-backend
-builtin
,id
=cryptodev0 \
4246 -device virtio
-crypto
-pci
,id
=crypto0
,cryptodev
=cryptodev0 \
4250 @item
-object cryptodev
-vhost
-user
,id
=@
var{id
},chardev
=@
var{chardevid
}[,queues
=@
var{queues
}]
4252 Creates a vhost
-user cryptodev backend
, backed by a chardev @
var{chardevid
}.
4253 The @
var{id
} parameter is a unique ID that will be used to reference
this
4254 cryptodev backend from the @option
{virtio
-crypto
} device
.
4255 The chardev should be a unix domain socket backed one
. The vhost
-user uses
4256 a specifically defined protocol to pass vhost ioctl replacement messages
4257 to an application on the other end of the socket
.
4258 The @
var{queues
} parameter is optional
, which specify the queue number
4259 of cryptodev backend
for multiqueue vhost
-user
, the
default of @
var{queues
} is
1.
4263 # qemu
-system
-x86_64 \
4265 -chardev socket
,id
=chardev0
,path
=/path
/to
/socket \
4266 -object cryptodev
-vhost
-user
,id
=cryptodev0
,chardev
=chardev0 \
4267 -device virtio
-crypto
-pci
,id
=crypto0
,cryptodev
=cryptodev0 \
4271 @item
-object secret
,id
=@
var{id
},data
=@
var{string
},format
=@
var{raw|base64
}[,keyid
=@
var{secretid
},iv
=@
var{string
}]
4272 @item
-object secret
,id
=@
var{id
},file
=@
var{filename
},format
=@
var{raw|base64
}[,keyid
=@
var{secretid
},iv
=@
var{string
}]
4274 Defines a secret to store a password
, encryption key
, or some other sensitive
4275 data
. The sensitive data can either be passed directly via the @
var{data
}
4276 parameter
, or indirectly via the @
var{file
} parameter
. Using the @
var{data
}
4277 parameter is insecure unless the sensitive data is encrypted
.
4279 The sensitive data can be provided
in raw
format (the
default), or base64
.
4280 When encoded as JSON
, the raw format only supports valid UTF
-8 characters
,
4281 so base64 is recommended
for sending binary data
. QEMU will convert from
4282 which ever format is provided to the format it needs internally
. eg
, an
4283 RBD password can be provided
in raw format
, even though it will be base64
4284 encoded when passed onto the RBD sever
.
4286 For added protection
, it is possible to encrypt the data associated with
4287 a secret
using the AES
-256-CBC cipher
. Use of encryption is indicated
4288 by providing the @
var{keyid
} and @
var{iv
} parameters
. The @
var{keyid
}
4289 parameter provides the ID of a previously defined secret that contains
4290 the AES
-256 decryption key
. This key should be
32-bytes long and be
4291 base64 encoded
. The @
var{iv
} parameter provides the random initialization
4292 vector used
for encryption of
this particular secret and should be a
4293 base64 encrypted string of the
16-byte IV
.
4295 The
simplest (insecure
) usage is to provide the secret
inline
4299 # $QEMU
-object secret
,id
=sec0
,data
=letmein
,format
=raw
4303 The simplest secure usage is to provide the secret via a file
4305 # printf
"letmein" > mypasswd
.txt
4306 # $QEMU
-object secret
,id
=sec0
,file
=mypasswd
.txt
,format
=raw
4308 For greater security
, AES
-256-CBC should be used
. To illustrate usage
,
4309 consider the openssl command line tool which can encrypt the data
. Note
4310 that when encrypting
, the plaintext must be padded to the cipher block
4311 size (32 bytes
) using the standard PKCS#
5/6 compatible padding algorithm
.
4313 First a master key needs to be created
in base64 encoding
:
4316 # openssl rand
-base64
32 > key
.b64
4317 # KEY
=$
(base64
-d key
.b64 | hexdump
-v
-e
'/1 "%02X"')
4320 Each secret to be encrypted needs to have a random initialization vector
4321 generated
. These
do not need to be kept secret
4324 # openssl rand
-base64
16 > iv
.b64
4325 # IV
=$
(base64
-d iv
.b64 | hexdump
-v
-e
'/1 "%02X"')
4328 The secret to be defined can now be encrypted
, in this case we
're
4329 telling openssl to base64 encode the result, but it could be left
4330 as raw bytes if desired.
4333 # SECRET=$(printf "letmein" |
4334 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4337 When launching QEMU, create a master secret pointing to @code{key.b64}
4338 and specify that to be used to decrypt the user password. Pass the
4339 contents of @code{iv.b64} to the second secret
4343 -object secret,id=secmaster0,format=base64,file=key.b64 \
4344 -object secret,id=sec0,keyid=secmaster0,format=base64,\
4345 data=$SECRET,iv=$(<iv.b64)
4348 @item -object sev-guest,id=@var{id},cbitpos=@var{cbitpos},reduced-phys-bits=@var{val},[sev-device=@var{string},policy=@var{policy},handle=@var{handle},dh-cert-file=@var{file},session-file=@var{file}]
4350 Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4351 to provide the guest memory encryption support on AMD processors.
4353 When memory encryption is enabled, one of the physical address bit (aka the
4354 C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4355 is used to provide the C-bit position. The C-bit position is Host family dependent
4356 hence user must provide this value. On EPYC, the value should be 47.
4358 When memory encryption is enabled, we loose certain bits in physical address space.
4359 The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4360 physical address space. Similar to C-bit, the value is Host family dependent.
4361 On EPYC, the value should be 5.
4363 The @option{sev-device} provides the device file to use for communicating with
4364 the SEV firmware running inside AMD Secure Processor. The default device is
4365 '/dev
/sev
'. If hardware supports memory encryption then /dev/sev devices are
4366 created by CCP driver.
4368 The @option{policy} provides the guest policy to be enforced by the SEV firmware
4369 and restrict what configuration and operational commands can be performed on this
4370 guest by the hypervisor. The policy should be provided by the guest owner and is
4371 bound to the guest and cannot be changed throughout the lifetime of the guest.
4374 If guest @option{policy} allows sharing the key with another SEV guest then
4375 @option{handle} can be use to provide handle of the guest from which to share
4378 The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4379 Public Diffie
-Hillman key defined
in SEV spec
. The PDH and session parameters
4380 are used
for establishing a cryptographic session with the guest owner to
4381 negotiate keys used
for attestation
. The file must be encoded
in base64
.
4383 e
.g to launch a SEV guest
4387 -object sev
-guest
,id
=sev0
,cbitpos
=47,reduced
-phys
-bits
=5 \
4388 -machine
...,memory
-encryption
=sev0
4394 @item
-object authz
-simple
,id
=@
var{id
},identity
=@
var{string
}
4396 Create an authorization object that will control access to network services
.
4398 The @option
{identity
} parameter is identifies the user and its format
4399 depends on the network service that authorization object is associated
4400 with
. For authorizing based on TLS x509 certificates
, the identity must
4401 be the x509 distinguished name
. Note that care must be taken to escape
4402 any commas
in the distinguished name
.
4404 An example authorization object to validate a x509 distinguished name
4409 -object
'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \
4413 Note the use of quotes due to the x509 distinguished name containing
4414 whitespace
, and escaping of
','.
4416 @item
-object authz
-listfile
,id
=@
var{id
},filename
=@
var{path
},refresh
=@
var{yes|no
}
4418 Create an authorization object that will control access to network services
.
4420 The @option
{filename
} parameter is the fully qualified path to a file
4421 containing the access control list rules
in JSON format
.
4423 An example set of rules that match against SASL usernames might look
4429 @
{ "match": "fred", "policy": "allow", "format": "exact" @
},
4430 @
{ "match": "bob", "policy": "allow", "format": "exact" @
},
4431 @
{ "match": "danb", "policy": "deny", "format": "glob" @
},
4432 @
{ "match": "dan*", "policy": "allow", "format": "exact" @
},
4438 When checking access the object will iterate over all the rules and
4439 the first rule to match will have its @option
{policy
} value returned
4440 as the result
. If no rules match
, then the
default @option
{policy
}
4443 The rules can either be an exact string match
, or they can use the
4444 simple UNIX glob pattern matching to allow wildcards to be used
.
4446 If @option
{refresh
} is set to
true the file will be monitored
4447 and automatically reloaded whenever its content changes
.
4449 As with the @code
{authz
-simple
} object
, the format of the identity
4450 strings being matched depends on the network service
, but is usually
4451 a TLS x509 distinguished name
, or a SASL username
.
4453 An example authorization object to validate a SASL username
4458 -object authz
-simple
,id
=auth0
,filename
=/etc
/qemu
/vnc
-sasl
.acl
,refresh
=yes
4462 @item
-object authz
-pam
,id
=@
var{id
},service
=@
var{string
}
4464 Create an authorization object that will control access to network services
.
4466 The @option
{service
} parameter provides the name of a PAM service to use
4467 for authorization
. It requires that a file @code
{/etc
/pam
.d
/@
var{service
}}
4468 exist to provide the configuration
for the @code
{account
} subsystem
.
4470 An example authorization object to validate a TLS x509 distinguished
4471 name would look like
:
4476 -object authz
-pam
,id
=auth0
,service
=qemu
-vnc
4480 There would then be a corresponding config file
for PAM at
4481 @code
{/etc
/pam
.d
/qemu
-vnc
} that contains
:
4484 account requisite pam_listfile
.so item
=user sense
=allow \
4485 file
=/etc
/qemu
/vnc
.allow
4488 Finally the @code
{/etc
/qemu
/vnc
.allow
} file would contain
4489 the list of x509 distingished names that are permitted
4493 CN
=laptop
.example
.com
,O
=Example Home
,L
=London
,ST
=London
,C
=GB
4502 HXCOMM This is the last statement
. Insert
new options before
this line
!