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1HXCOMM Use DEFHEADING() to define headings in both help text and texi
2HXCOMM Text between STEXI and ETEXI are copied to texi version and
3HXCOMM discarded from C version
4HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to
5HXCOMM construct option structures, enums and help message for specified
6HXCOMM architectures.
7HXCOMM HXCOMM can be used for comments, discarded from both texi and C
8
9DEFHEADING(Standard options:)
10STEXI
11@table @option
12ETEXI
13
14DEF("help", 0, QEMU_OPTION_h,
15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL)
16STEXI
17@item -h
18@findex -h
19Display help and exit
20ETEXI
21
22DEF("version", 0, QEMU_OPTION_version,
23 "-version display version information and exit\n", QEMU_ARCH_ALL)
24STEXI
25@item -version
26@findex -version
27Display version information and exit
28ETEXI
29
30DEF("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",
47 QEMU_ARCH_ALL)
48STEXI
49@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
50@findex -machine
51Select the emulated machine by @var{name}. Use @code{-machine help} to list
52available machines.
53
54For architectures which aim to support live migration compatibility
55across releases, each release will introduce a new versioned machine
56type. 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.
58
59To allow live migration of guests from QEMU version 2.8.0, to QEMU
60version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8''
61and ``pc-q35-2.8'' machines too. To allow users live migrating VMs
62to skip multiple intermediate releases when upgrading, new releases
63of QEMU will support machine types from many previous versions.
64
65Supported machine properties are:
66@table @option
67@item accel=@var{accels1}[:@var{accels2}[:...]]
68This is used to enable an accelerator. Depending on the target architecture,
69kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
70more than one accelerator specified, the next one is used if the previous one
71fails to initialize.
72@item kernel_irqchip=on|off
73Controls in-kernel irqchip support for the chosen accelerator when available.
74@item gfx_passthru=on|off
75Enables IGD GFX passthrough support for the chosen machine when available.
76@item vmport=on|off|auto
77Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
78value based on accel. For accel=xen the default is off otherwise the default
79is on.
80@item kvm_shadow_mem=size
81Defines the size of the KVM shadow MMU.
82@item dump-guest-core=on|off
83Include guest memory in a core dump. The default is on.
84@item mem-merge=on|off
85Enables or disables memory merge support. This feature, when supported by
86the host, de-duplicates identical memory pages among VMs instances
87(enabled by default).
88@item aes-key-wrap=on|off
89Enables or disables AES key wrapping support on s390-ccw hosts. This feature
90controls whether AES wrapping keys will be created to allow
91execution of AES cryptographic functions. The default is on.
92@item dea-key-wrap=on|off
93Enables or disables DEA key wrapping support on s390-ccw hosts. This feature
94controls whether DEA wrapping keys will be created to allow
95execution of DEA cryptographic functions. The default is on.
96@item nvdimm=on|off
97Enables or disables NVDIMM support. The default is off.
98@item enforce-config-section=on|off
99If @option{enforce-config-section} is set to @var{on}, force migration
100code to send configuration section even if the machine-type sets the
101@option{migration.send-configuration} property to @var{off}.
102NOTE: this parameter is deprecated. Please use @option{-global}
103@option{migration.send-configuration}=@var{on|off} instead.
104@item memory-encryption=@var{}
105Memory encryption object to use. The default is none.
106@end table
107ETEXI
108
109HXCOMM Deprecated by -machine
110DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
111
112DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
113 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
114STEXI
115@item -cpu @var{model}
116@findex -cpu
117Select CPU model (@code{-cpu help} for list and additional feature selection)
118ETEXI
119
120DEF("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)
124STEXI
125@item -accel @var{name}[,prop=@var{value}[,...]]
126@findex -accel
127This is used to enable an accelerator. Depending on the target architecture,
128kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
129more than one accelerator specified, the next one is used if the previous one
130fails to initialize.
131@table @option
132@item thread=single|multi
133Controls number of TCG threads. When the TCG is multi-threaded there will be one
134thread per vCPU therefor taking advantage of additional host cores. The default
135is to enable multi-threading where both the back-end and front-ends support it and
136no incompatible TCG features have been enabled (e.g. icount/replay).
137@end table
138ETEXI
139
140DEF("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",
148 QEMU_ARCH_ALL)
149STEXI
150@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
151@findex -smp
152Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
153CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
154to 4.
155For the PC target, the number of @var{cores} per socket, the number
156of @var{threads} per cores and the total number of @var{sockets} can be
157specified. Missing values will be computed. If any on the three values is
158given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
159specifies the maximum number of hotpluggable CPUs.
160ETEXI
161
162DEF("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",
167 QEMU_ARCH_ALL)
168STEXI
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}]
173@findex -numa
174Define a NUMA node and assign RAM and VCPUs to it.
175Set the NUMA distance from a source node to a destination node.
176
177Legacy 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
181set of VCPUs can be represented by providing multiple @samp{cpus}
182options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically
183split between them.
184
185For example, the following option assigns VCPUs 0, 1, 2 and 5 to
186a NUMA node:
187@example
188-numa node,cpus=0-2,cpus=5
189@end example
190
191@samp{cpu} option is a new alternative to @samp{cpus} option
192which uses @samp{socket-id|core-id|thread-id} properties to assign
193CPU objects to a @var{node} using topology layout properties of CPU.
194The set of properties is machine specific, and depends on used
195machine 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
198will be assigned, it's required for @var{node} to be declared
199with @samp{node} option before it's used with @samp{cpu} option.
200
201For example:
202@example
203-M pc \
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
207@end example
208
209@samp{mem} assigns a given RAM amount to a node. @samp{memdev}
210assigns RAM from a given memory backend device to a node. If
211@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is
212split equally between them.
213
214@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
215if one node uses @samp{memdev}, all of them have to use it.
216
217@var{source} and @var{destination} are NUMA node IDs.
218@var{distance} is the NUMA distance from @var{source} to @var{destination}.
219The distance from a node to itself is always 10. If any pair of nodes is
220given a distance, then all pairs must be given distances. Although, when
221distances are only given in one direction for each pair of nodes, then
222the distances in the opposite directions are assumed to be the same. If,
223however, an asymmetrical pair of distances is given for even one node
224pair, then all node pairs must be provided distance values for both
225directions, even when they are symmetrical. When a node is unreachable
226from another node, set the pair's distance to 255.
227
228Note that the -@option{numa} option doesn't allocate any of the
229specified resources, it just assigns existing resources to NUMA
230nodes. This means that one still has to use the @option{-m},
231@option{-smp} options to allocate RAM and VCPUs respectively.
232
233ETEXI
234
235DEF("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)
238STEXI
239@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
240@findex -add-fd
241
242Add a file descriptor to an fd set. Valid options are:
243
244@table @option
245@item fd=@var{fd}
246This option defines the file descriptor of which a duplicate is added to fd set.
247The file descriptor cannot be stdin, stdout, or stderr.
248@item set=@var{set}
249This option defines the ID of the fd set to add the file descriptor to.
250@item opaque=@var{opaque}
251This option defines a free-form string that can be used to describe @var{fd}.
252@end table
253
254You can open an image using pre-opened file descriptors from an fd set:
255@example
256qemu-system-i386
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
260@end example
261ETEXI
262
263DEF("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)
267STEXI
268@item -set @var{group}.@var{id}.@var{arg}=@var{value}
269@findex -set
270Set parameter @var{arg} for item @var{id} of type @var{group}
271ETEXI
272
273DEF("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",
277 QEMU_ARCH_ALL)
278STEXI
279@item -global @var{driver}.@var{prop}=@var{value}
280@itemx -global driver=@var{driver},property=@var{property},value=@var{value}
281@findex -global
282Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
283
284@example
285qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
286@end example
287
288In particular, you can use this to set driver properties for devices which are
289created automatically by the machine model. To create a device which is not
290created automatically and set properties on it, use -@option{device}.
291
292-global @var{driver}.@var{prop}=@var{value} is shorthand for -global
293driver=@var{driver},property=@var{prop},value=@var{value}. The
294longhand syntax works even when @var{driver} contains a dot.
295ETEXI
296
297DEF("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",
304 QEMU_ARCH_ALL)
305STEXI
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]
307@findex -boot
308Specify boot order @var{drives} as a string of drive letters. Valid
309drive 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
311from network adapter 1-4), hard disk boot is the default. To apply a
312particular boot order only on the first startup, specify it via
313@option{once}. Note that the @option{order} or @option{once} parameter
314should not be used together with the @option{bootindex} property of
315devices, since the firmware implementations normally do not support both
316at the same time.
317
318Interactive boot menus/prompts can be enabled via @option{menu=on} as far
319as firmware/BIOS supports them. The default is non-interactive boot.
320
321A splash picture could be passed to bios, enabling user to show it as logo,
322when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
323supports them. Currently Seabios for X86 system support it.
324limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
325format(true color). The resolution should be supported by the SVGA mode, so
326the recommended is 320x240, 640x480, 800x640.
327
328A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
329when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
330reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
331system support it.
332
333Do strict boot via @option{strict=on} as far as firmware/BIOS
334supports it. This only effects when boot priority is changed by
335bootindex options. The default is non-strict boot.
336
337@example
338# try to boot from network first, then from hard disk
339qemu-system-i386 -boot order=nc
340# boot from CD-ROM first, switch back to default order after reboot
341qemu-system-i386 -boot once=d
342# boot with a splash picture for 5 seconds.
343qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
344@end example
345
346Note: The legacy format '-boot @var{drives}' is still supported but its
347use is discouraged as it may be removed from future versions.
348ETEXI
349
350DEF("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",
357 QEMU_ARCH_ALL)
358STEXI
359@item -m [size=]@var{megs}[,slots=n,maxmem=size]
360@findex -m
361Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
362Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
363megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
364could be used to set amount of hotpluggable memory slots and maximum amount of
365memory. Note that @var{maxmem} must be aligned to the page size.
366
367For example, the following command-line sets the guest startup RAM size to
3681GB, creates 3 slots to hotplug additional memory and sets the maximum
369memory the guest can reach to 4GB:
370
371@example
372qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
373@end example
374
375If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
376be enabled and the guest startup RAM will never increase.
377ETEXI
378
379DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
380 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
381STEXI
382@item -mem-path @var{path}
383@findex -mem-path
384Allocate guest RAM from a temporarily created file in @var{path}.
385ETEXI
386
387DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
388 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
389 QEMU_ARCH_ALL)
390STEXI
391@item -mem-prealloc
392@findex -mem-prealloc
393Preallocate memory when using -mem-path.
394ETEXI
395
396DEF("k", HAS_ARG, QEMU_OPTION_k,
397 "-k language use keyboard layout (for example 'fr' for French)\n",
398 QEMU_ARCH_ALL)
399STEXI
400@item -k @var{language}
401@findex -k
402Use keyboard layout @var{language} (for example @code{fr} for
403French). This option is only needed where it is not easy to get raw PC
404keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
405display). You don't normally need to use it on PC/Linux or PC/Windows
406hosts.
407
408The available layouts are:
409@example
410ar de-ch es fo fr-ca hu ja mk no pt-br sv
411da en-gb et fr fr-ch is lt nl pl ru th
412de en-us fi fr-be hr it lv nl-be pt sl tr
413@end example
414
415The default is @code{en-us}.
416ETEXI
417
418
419DEF("audio-help", 0, QEMU_OPTION_audio_help,
420 "-audio-help print list of audio drivers and their options\n",
421 QEMU_ARCH_ALL)
422STEXI
423@item -audio-help
424@findex -audio-help
425Will show the audio subsystem help: list of drivers, tunable
426parameters.
427ETEXI
428
429DEF("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)
434STEXI
435@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
436@findex -soundhw
437Enable audio and selected sound hardware. Use 'help' to print all
438available sound hardware.
439
440@example
441qemu-system-i386 -soundhw sb16,adlib disk.img
442qemu-system-i386 -soundhw es1370 disk.img
443qemu-system-i386 -soundhw ac97 disk.img
444qemu-system-i386 -soundhw hda disk.img
445qemu-system-i386 -soundhw all disk.img
446qemu-system-i386 -soundhw help
447@end example
448
449Note that Linux's i810_audio OSS kernel (for AC97) module might
450require manually specifying clocking.
451
452@example
453modprobe i810_audio clocking=48000
454@end example
455ETEXI
456
457DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
458 "-balloon virtio[,addr=str]\n"
459 " enable virtio balloon device (deprecated)\n", QEMU_ARCH_ALL)
460STEXI
461@item -balloon virtio[,addr=@var{addr}]
462@findex -balloon
463Enable virtio balloon device, optionally with PCI address @var{addr}. This
464option is deprecated, use @option{-device virtio-balloon} instead.
465ETEXI
466
467DEF("device", HAS_ARG, QEMU_OPTION_device,
468 "-device driver[,prop[=value][,...]]\n"
469 " add device (based on driver)\n"
470 " prop=value,... sets driver properties\n"
471 " use '-device help' to print all possible drivers\n"
472 " use '-device driver,help' to print all possible properties\n",
473 QEMU_ARCH_ALL)
474STEXI
475@item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
476@findex -device
477Add device @var{driver}. @var{prop}=@var{value} sets driver
478properties. Valid properties depend on the driver. To get help on
479possible drivers and properties, use @code{-device help} and
480@code{-device @var{driver},help}.
481
482Some drivers are:
483@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
484
485Add an IPMI BMC. This is a simulation of a hardware management
486interface processor that normally sits on a system. It provides
487a watchdog and the ability to reset and power control the system.
488You need to connect this to an IPMI interface to make it useful
489
490The IPMI slave address to use for the BMC. The default is 0x20.
491This address is the BMC's address on the I2C network of management
492controllers. If you don't know what this means, it is safe to ignore
493it.
494
495@table @option
496@item bmc=@var{id}
497The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
498@item slave_addr=@var{val}
499Define slave address to use for the BMC. The default is 0x20.
500@item sdrfile=@var{file}
501file containing raw Sensor Data Records (SDR) data. The default is none.
502@item fruareasize=@var{val}
503size of a Field Replaceable Unit (FRU) area. The default is 1024.
504@item frudatafile=@var{file}
505file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
506@end table
507
508@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
509
510Add a connection to an external IPMI BMC simulator. Instead of
511locally emulating the BMC like the above item, instead connect
512to an external entity that provides the IPMI services.
513
514A connection is made to an external BMC simulator. If you do this, it
515is strongly recommended that you use the "reconnect=" chardev option
516to reconnect to the simulator if the connection is lost. Note that if
517this is not used carefully, it can be a security issue, as the
518interface has the ability to send resets, NMIs, and power off the VM.
519It's best if QEMU makes a connection to an external simulator running
520on a secure port on localhost, so neither the simulator nor QEMU is
521exposed to any outside network.
522
523See the "lanserv/README.vm" file in the OpenIPMI library for more
524details on the external interface.
525
526@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
527
528Add a KCS IPMI interafce on the ISA bus. This also adds a
529corresponding ACPI and SMBIOS entries, if appropriate.
530
531@table @option
532@item bmc=@var{id}
533The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
534@item ioport=@var{val}
535Define the I/O address of the interface. The default is 0xca0 for KCS.
536@item irq=@var{val}
537Define the interrupt to use. The default is 5. To disable interrupts,
538set this to 0.
539@end table
540
541@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
542
543Like the KCS interface, but defines a BT interface. The default port is
5440xe4 and the default interrupt is 5.
545
546ETEXI
547
548DEF("name", HAS_ARG, QEMU_OPTION_name,
549 "-name string1[,process=string2][,debug-threads=on|off]\n"
550 " set the name of the guest\n"
551 " string1 sets the window title and string2 the process name (on Linux)\n"
552 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
553 " NOTE: The thread names are for debugging and not a stable API.\n",
554 QEMU_ARCH_ALL)
555STEXI
556@item -name @var{name}
557@findex -name
558Sets the @var{name} of the guest.
559This name will be displayed in the SDL window caption.
560The @var{name} will also be used for the VNC server.
561Also optionally set the top visible process name in Linux.
562Naming of individual threads can also be enabled on Linux to aid debugging.
563ETEXI
564
565DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
566 "-uuid %08x-%04x-%04x-%04x-%012x\n"
567 " specify machine UUID\n", QEMU_ARCH_ALL)
568STEXI
569@item -uuid @var{uuid}
570@findex -uuid
571Set system UUID.
572ETEXI
573
574STEXI
575@end table
576ETEXI
577DEFHEADING()
578
579DEFHEADING(Block device options:)
580STEXI
581@table @option
582ETEXI
583
584DEF("fda", HAS_ARG, QEMU_OPTION_fda,
585 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
586DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
587STEXI
588@item -fda @var{file}
589@itemx -fdb @var{file}
590@findex -fda
591@findex -fdb
592Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
593ETEXI
594
595DEF("hda", HAS_ARG, QEMU_OPTION_hda,
596 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
597DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
598DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
599 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
600DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
601STEXI
602@item -hda @var{file}
603@itemx -hdb @var{file}
604@itemx -hdc @var{file}
605@itemx -hdd @var{file}
606@findex -hda
607@findex -hdb
608@findex -hdc
609@findex -hdd
610Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
611ETEXI
612
613DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
614 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
615 QEMU_ARCH_ALL)
616STEXI
617@item -cdrom @var{file}
618@findex -cdrom
619Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
620@option{-cdrom} at the same time). You can use the host CD-ROM by
621using @file{/dev/cdrom} as filename (@pxref{host_drives}).
622ETEXI
623
624DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
625 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
626 " [,cache.direct=on|off][,cache.no-flush=on|off]\n"
627 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
628 " [,driver specific parameters...]\n"
629 " configure a block backend\n", QEMU_ARCH_ALL)
630STEXI
631@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
632@findex -blockdev
633
634Define a new block driver node. Some of the options apply to all block drivers,
635other options are only accepted for a specific block driver. See below for a
636list of generic options and options for the most common block drivers.
637
638Options that expect a reference to another node (e.g. @code{file}) can be
639given in two ways. Either you specify the node name of an already existing node
640(file=@var{node-name}), or you define a new node inline, adding options
641for the referenced node after a dot (file.filename=@var{path},file.aio=native).
642
643A block driver node created with @option{-blockdev} can be used for a guest
644device by specifying its node name for the @code{drive} property in a
645@option{-device} argument that defines a block device.
646
647@table @option
648@item Valid options for any block driver node:
649
650@table @code
651@item driver
652Specifies the block driver to use for the given node.
653@item node-name
654This defines the name of the block driver node by which it will be referenced
655later. The name must be unique, i.e. it must not match the name of a different
656block driver node, or (if you use @option{-drive} as well) the ID of a drive.
657
658If no node name is specified, it is automatically generated. The generated node
659name is not intended to be predictable and changes between QEMU invocations.
660For the top level, an explicit node name must be specified.
661@item read-only
662Open the node read-only. Guest write attempts will fail.
663@item cache.direct
664The host page cache can be avoided with @option{cache.direct=on}. This will
665attempt to do disk IO directly to the guest's memory. QEMU may still perform an
666internal copy of the data.
667@item cache.no-flush
668In case you don't care about data integrity over host failures, you can use
669@option{cache.no-flush=on}. This option tells QEMU that it never needs to write
670any data to the disk but can instead keep things in cache. If anything goes
671wrong, like your host losing power, the disk storage getting disconnected
672accidentally, etc. your image will most probably be rendered unusable.
673@item discard=@var{discard}
674@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls
675whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
676ignored or passed to the filesystem. Some machine types may not support
677discard requests.
678@item detect-zeroes=@var{detect-zeroes}
679@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
680conversion of plain zero writes by the OS to driver specific optimized
681zero write commands. You may even choose "unmap" if @var{discard} is set
682to "unmap" to allow a zero write to be converted to an @code{unmap} operation.
683@end table
684
685@item Driver-specific options for @code{file}
686
687This is the protocol-level block driver for accessing regular files.
688
689@table @code
690@item filename
691The path to the image file in the local filesystem
692@item aio
693Specifies the AIO backend (threads/native, default: threads)
694@item locking
695Specifies whether the image file is protected with Linux OFD / POSIX locks. The
696default is to use the Linux Open File Descriptor API if available, otherwise no
697lock is applied. (auto/on/off, default: auto)
698@end table
699Example:
700@example
701-blockdev driver=file,node-name=disk,filename=disk.img
702@end example
703
704@item Driver-specific options for @code{raw}
705
706This is the image format block driver for raw images. It is usually
707stacked on top of a protocol level block driver such as @code{file}.
708
709@table @code
710@item file
711Reference to or definition of the data source block driver node
712(e.g. a @code{file} driver node)
713@end table
714Example 1:
715@example
716-blockdev driver=file,node-name=disk_file,filename=disk.img
717-blockdev driver=raw,node-name=disk,file=disk_file
718@end example
719Example 2:
720@example
721-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
722@end example
723
724@item Driver-specific options for @code{qcow2}
725
726This is the image format block driver for qcow2 images. It is usually
727stacked on top of a protocol level block driver such as @code{file}.
728
729@table @code
730@item file
731Reference to or definition of the data source block driver node
732(e.g. a @code{file} driver node)
733
734@item backing
735Reference to or definition of the backing file block device (default is taken
736from the image file). It is allowed to pass @code{null} here in order to disable
737the default backing file.
738
739@item lazy-refcounts
740Whether to enable the lazy refcounts feature (on/off; default is taken from the
741image file)
742
743@item cache-size
744The maximum total size of the L2 table and refcount block caches in bytes
745(default: 1048576 bytes or 8 clusters, whichever is larger)
746
747@item l2-cache-size
748The maximum size of the L2 table cache in bytes
749(default: 4/5 of the total cache size)
750
751@item refcount-cache-size
752The maximum size of the refcount block cache in bytes
753(default: 1/5 of the total cache size)
754
755@item cache-clean-interval
756Clean unused entries in the L2 and refcount caches. The interval is in seconds.
757The default value is 0 and it disables this feature.
758
759@item pass-discard-request
760Whether discard requests to the qcow2 device should be forwarded to the data
761source (on/off; default: on if discard=unmap is specified, off otherwise)
762
763@item pass-discard-snapshot
764Whether discard requests for the data source should be issued when a snapshot
765operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
766default: on)
767
768@item pass-discard-other
769Whether discard requests for the data source should be issued on other
770occasions where a cluster gets freed (on/off; default: off)
771
772@item overlap-check
773Which overlap checks to perform for writes to the image
774(none/constant/cached/all; default: cached). For details or finer
775granularity control refer to the QAPI documentation of @code{blockdev-add}.
776@end table
777
778Example 1:
779@example
780-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
781-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
782@end example
783Example 2:
784@example
785-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
786@end example
787
788@item Driver-specific options for other drivers
789Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
790
791@end table
792
793ETEXI
794
795DEF("drive", HAS_ARG, QEMU_OPTION_drive,
796 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
797 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
798 " [,snapshot=on|off][,rerror=ignore|stop|report]\n"
799 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
800 " [,readonly=on|off][,copy-on-read=on|off]\n"
801 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
802 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
803 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
804 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
805 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
806 " [[,iops_size=is]]\n"
807 " [[,group=g]]\n"
808 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
809STEXI
810@item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
811@findex -drive
812
813Define a new drive. This includes creating a block driver node (the backend) as
814well as a guest device, and is mostly a shortcut for defining the corresponding
815@option{-blockdev} and @option{-device} options.
816
817@option{-drive} accepts all options that are accepted by @option{-blockdev}. In
818addition, it knows the following options:
819
820@table @option
821@item file=@var{file}
822This option defines which disk image (@pxref{disk_images}) to use with
823this drive. If the filename contains comma, you must double it
824(for instance, "file=my,,file" to use file "my,file").
825
826Special files such as iSCSI devices can be specified using protocol
827specific URLs. See the section for "Device URL Syntax" for more information.
828@item if=@var{interface}
829This option defines on which type on interface the drive is connected.
830Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
831@item bus=@var{bus},unit=@var{unit}
832These options define where is connected the drive by defining the bus number and
833the unit id.
834@item index=@var{index}
835This option defines where is connected the drive by using an index in the list
836of available connectors of a given interface type.
837@item media=@var{media}
838This option defines the type of the media: disk or cdrom.
839@item snapshot=@var{snapshot}
840@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
841(see @option{-snapshot}).
842@item cache=@var{cache}
843@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
844and controls how the host cache is used to access block data. This is a
845shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
846options (as in @option{-blockdev}), and additionally @option{cache.writeback},
847which provides a default for the @option{write-cache} option of block guest
848devices (as in @option{-device}). The modes correspond to the following
849settings:
850
851@c Our texi2pod.pl script doesn't support @multitable, so fall back to using
852@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
853@c and the HTML output.
854@example
855@ │ cache.writeback cache.direct cache.no-flush
856─────────────┼─────────────────────────────────────────────────
857writeback │ on off off
858none │ on on off
859writethrough │ off off off
860directsync │ off on off
861unsafe │ on off on
862@end example
863
864The default mode is @option{cache=writeback}.
865
866@item aio=@var{aio}
867@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
868@item format=@var{format}
869Specify which disk @var{format} will be used rather than detecting
870the format. Can be used to specify format=raw to avoid interpreting
871an untrusted format header.
872@item werror=@var{action},rerror=@var{action}
873Specify which @var{action} to take on write and read errors. Valid actions are:
874"ignore" (ignore the error and try to continue), "stop" (pause QEMU),
875"report" (report the error to the guest), "enospc" (pause QEMU only if the
876host disk is full; report the error to the guest otherwise).
877The default setting is @option{werror=enospc} and @option{rerror=report}.
878@item copy-on-read=@var{copy-on-read}
879@var{copy-on-read} is "on" or "off" and enables whether to copy read backing
880file sectors into the image file.
881@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
882Specify bandwidth throttling limits in bytes per second, either for all request
883types or for reads or writes only. Small values can lead to timeouts or hangs
884inside the guest. A safe minimum for disks is 2 MB/s.
885@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
886Specify bursts in bytes per second, either for all request types or for reads
887or writes only. Bursts allow the guest I/O to spike above the limit
888temporarily.
889@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
890Specify request rate limits in requests per second, either for all request
891types or for reads or writes only.
892@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
893Specify bursts in requests per second, either for all request types or for reads
894or writes only. Bursts allow the guest I/O to spike above the limit
895temporarily.
896@item iops_size=@var{is}
897Let every @var{is} bytes of a request count as a new request for iops
898throttling purposes. Use this option to prevent guests from circumventing iops
899limits by sending fewer but larger requests.
900@item group=@var{g}
901Join a throttling quota group with given name @var{g}. All drives that are
902members of the same group are accounted for together. Use this option to
903prevent guests from circumventing throttling limits by using many small disks
904instead of a single larger disk.
905@end table
906
907By default, the @option{cache.writeback=on} mode is used. It will report data
908writes as completed as soon as the data is present in the host page cache.
909This is safe as long as your guest OS makes sure to correctly flush disk caches
910where needed. If your guest OS does not handle volatile disk write caches
911correctly and your host crashes or loses power, then the guest may experience
912data corruption.
913
914For such guests, you should consider using @option{cache.writeback=off}. This
915means that the host page cache will be used to read and write data, but write
916notification will be sent to the guest only after QEMU has made sure to flush
917each write to the disk. Be aware that this has a major impact on performance.
918
919When using the @option{-snapshot} option, unsafe caching is always used.
920
921Copy-on-read avoids accessing the same backing file sectors repeatedly and is
922useful when the backing file is over a slow network. By default copy-on-read
923is off.
924
925Instead of @option{-cdrom} you can use:
926@example
927qemu-system-i386 -drive file=file,index=2,media=cdrom
928@end example
929
930Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
931use:
932@example
933qemu-system-i386 -drive file=file,index=0,media=disk
934qemu-system-i386 -drive file=file,index=1,media=disk
935qemu-system-i386 -drive file=file,index=2,media=disk
936qemu-system-i386 -drive file=file,index=3,media=disk
937@end example
938
939You can open an image using pre-opened file descriptors from an fd set:
940@example
941qemu-system-i386
942-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
943-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
944-drive file=/dev/fdset/2,index=0,media=disk
945@end example
946
947You can connect a CDROM to the slave of ide0:
948@example
949qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
950@end example
951
952If you don't specify the "file=" argument, you define an empty drive:
953@example
954qemu-system-i386 -drive if=ide,index=1,media=cdrom
955@end example
956
957Instead of @option{-fda}, @option{-fdb}, you can use:
958@example
959qemu-system-i386 -drive file=file,index=0,if=floppy
960qemu-system-i386 -drive file=file,index=1,if=floppy
961@end example
962
963By default, @var{interface} is "ide" and @var{index} is automatically
964incremented:
965@example
966qemu-system-i386 -drive file=a -drive file=b"
967@end example
968is interpreted like:
969@example
970qemu-system-i386 -hda a -hdb b
971@end example
972ETEXI
973
974DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
975 "-mtdblock file use 'file' as on-board Flash memory image\n",
976 QEMU_ARCH_ALL)
977STEXI
978@item -mtdblock @var{file}
979@findex -mtdblock
980Use @var{file} as on-board Flash memory image.
981ETEXI
982
983DEF("sd", HAS_ARG, QEMU_OPTION_sd,
984 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
985STEXI
986@item -sd @var{file}
987@findex -sd
988Use @var{file} as SecureDigital card image.
989ETEXI
990
991DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
992 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
993STEXI
994@item -pflash @var{file}
995@findex -pflash
996Use @var{file} as a parallel flash image.
997ETEXI
998
999DEF("snapshot", 0, QEMU_OPTION_snapshot,
1000 "-snapshot write to temporary files instead of disk image files\n",
1001 QEMU_ARCH_ALL)
1002STEXI
1003@item -snapshot
1004@findex -snapshot
1005Write to temporary files instead of disk image files. In this case,
1006the raw disk image you use is not written back. You can however force
1007the write back by pressing @key{C-a s} (@pxref{disk_images}).
1008ETEXI
1009
1010DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
1011 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1012 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1013 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1014 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1015 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1016 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1017 " [[,throttling.iops-size=is]]\n",
1018 QEMU_ARCH_ALL)
1019
1020STEXI
1021
1022@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}]
1023@findex -fsdev
1024Define a new file system device. Valid options are:
1025@table @option
1026@item @var{fsdriver}
1027This option specifies the fs driver backend to use.
1028Currently "local", "handle" and "proxy" file system drivers are supported.
1029@item id=@var{id}
1030Specifies identifier for this device
1031@item path=@var{path}
1032Specifies the export path for the file system device. Files under
1033this path will be available to the 9p client on the guest.
1034@item security_model=@var{security_model}
1035Specifies the security model to be used for this export path.
1036Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1037In "passthrough" security model, files are stored using the same
1038credentials as they are created on the guest. This requires QEMU
1039to run as root. In "mapped-xattr" security model, some of the file
1040attributes like uid, gid, mode bits and link target are stored as
1041file attributes. For "mapped-file" these attributes are stored in the
1042hidden .virtfs_metadata directory. Directories exported by this security model cannot
1043interact with other unix tools. "none" security model is same as
1044passthrough except the sever won't report failures if it fails to
1045set file attributes like ownership. Security model is mandatory
1046only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
1047security model as a parameter.
1048@item writeout=@var{writeout}
1049This is an optional argument. The only supported value is "immediate".
1050This means that host page cache will be used to read and write data but
1051write notification will be sent to the guest only when the data has been
1052reported as written by the storage subsystem.
1053@item readonly
1054Enables exporting 9p share as a readonly mount for guests. By default
1055read-write access is given.
1056@item socket=@var{socket}
1057Enables proxy filesystem driver to use passed socket file for communicating
1058with virtfs-proxy-helper
1059@item sock_fd=@var{sock_fd}
1060Enables proxy filesystem driver to use passed socket descriptor for
1061communicating with virtfs-proxy-helper. Usually a helper like libvirt
1062will create socketpair and pass one of the fds as sock_fd
1063@item fmode=@var{fmode}
1064Specifies the default mode for newly created files on the host. Works only
1065with security models "mapped-xattr" and "mapped-file".
1066@item dmode=@var{dmode}
1067Specifies the default mode for newly created directories on the host. Works
1068only with security models "mapped-xattr" and "mapped-file".
1069@end table
1070
1071-fsdev option is used along with -device driver "virtio-9p-pci".
1072@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
1073Options for virtio-9p-pci driver are:
1074@table @option
1075@item fsdev=@var{id}
1076Specifies the id value specified along with -fsdev option
1077@item mount_tag=@var{mount_tag}
1078Specifies the tag name to be used by the guest to mount this export point
1079@end table
1080
1081ETEXI
1082
1083DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
1084 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1085 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1086 QEMU_ARCH_ALL)
1087
1088STEXI
1089
1090@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}]
1091@findex -virtfs
1092
1093The general form of a Virtual File system pass-through options are:
1094@table @option
1095@item @var{fsdriver}
1096This option specifies the fs driver backend to use.
1097Currently "local", "handle" and "proxy" file system drivers are supported.
1098@item id=@var{id}
1099Specifies identifier for this device
1100@item path=@var{path}
1101Specifies the export path for the file system device. Files under
1102this path will be available to the 9p client on the guest.
1103@item security_model=@var{security_model}
1104Specifies the security model to be used for this export path.
1105Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1106In "passthrough" security model, files are stored using the same
1107credentials as they are created on the guest. This requires QEMU
1108to run as root. In "mapped-xattr" security model, some of the file
1109attributes like uid, gid, mode bits and link target are stored as
1110file attributes. For "mapped-file" these attributes are stored in the
1111hidden .virtfs_metadata directory. Directories exported by this security model cannot
1112interact with other unix tools. "none" security model is same as
1113passthrough except the sever won't report failures if it fails to
1114set file attributes like ownership. Security model is mandatory only
1115for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
1116model as a parameter.
1117@item writeout=@var{writeout}
1118This is an optional argument. The only supported value is "immediate".
1119This means that host page cache will be used to read and write data but
1120write notification will be sent to the guest only when the data has been
1121reported as written by the storage subsystem.
1122@item readonly
1123Enables exporting 9p share as a readonly mount for guests. By default
1124read-write access is given.
1125@item socket=@var{socket}
1126Enables proxy filesystem driver to use passed socket file for
1127communicating with virtfs-proxy-helper. Usually a helper like libvirt
1128will create socketpair and pass one of the fds as sock_fd
1129@item sock_fd
1130Enables proxy filesystem driver to use passed 'sock_fd' as the socket
1131descriptor for interfacing with virtfs-proxy-helper
1132@item fmode=@var{fmode}
1133Specifies the default mode for newly created files on the host. Works only
1134with security models "mapped-xattr" and "mapped-file".
1135@item dmode=@var{dmode}
1136Specifies the default mode for newly created directories on the host. Works
1137only with security models "mapped-xattr" and "mapped-file".
1138@end table
1139ETEXI
1140
1141DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
1142 "-virtfs_synth Create synthetic file system image\n",
1143 QEMU_ARCH_ALL)
1144STEXI
1145@item -virtfs_synth
1146@findex -virtfs_synth
1147Create synthetic file system image
1148ETEXI
1149
1150DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1151 "-iscsi [user=user][,password=password]\n"
1152 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1153 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1154 " [,timeout=timeout]\n"
1155 " iSCSI session parameters\n", QEMU_ARCH_ALL)
1156
1157STEXI
1158@item -iscsi
1159@findex -iscsi
1160Configure iSCSI session parameters.
1161ETEXI
1162
1163STEXI
1164@end table
1165ETEXI
1166DEFHEADING()
1167
1168DEFHEADING(USB options:)
1169STEXI
1170@table @option
1171ETEXI
1172
1173DEF("usb", 0, QEMU_OPTION_usb,
1174 "-usb enable the USB driver (if it is not used by default yet)\n",
1175 QEMU_ARCH_ALL)
1176STEXI
1177@item -usb
1178@findex -usb
1179Enable the USB driver (if it is not used by default yet).
1180ETEXI
1181
1182DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1183 "-usbdevice name add the host or guest USB device 'name'\n",
1184 QEMU_ARCH_ALL)
1185STEXI
1186
1187@item -usbdevice @var{devname}
1188@findex -usbdevice
1189Add the USB device @var{devname}. Note that this option is deprecated,
1190please use @code{-device usb-...} instead. @xref{usb_devices}.
1191
1192@table @option
1193
1194@item mouse
1195Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1196
1197@item tablet
1198Pointer device that uses absolute coordinates (like a touchscreen). This
1199means QEMU is able to report the mouse position without having to grab the
1200mouse. Also overrides the PS/2 mouse emulation when activated.
1201
1202@item braille
1203Braille device. This will use BrlAPI to display the braille output on a real
1204or fake device.
1205
1206@end table
1207ETEXI
1208
1209STEXI
1210@end table
1211ETEXI
1212DEFHEADING()
1213
1214DEFHEADING(Display options:)
1215STEXI
1216@table @option
1217ETEXI
1218
1219DEF("display", HAS_ARG, QEMU_OPTION_display,
1220 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1221 " [,window_close=on|off][,gl=on|core|es|off]\n"
1222 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1223 "-display vnc=<display>[,<optargs>]\n"
1224 "-display curses\n"
1225 "-display none"
1226 " select display type\n"
1227 "The default display is equivalent to\n"
1228#if defined(CONFIG_GTK)
1229 "\t\"-display gtk\"\n"
1230#elif defined(CONFIG_SDL)
1231 "\t\"-display sdl\"\n"
1232#elif defined(CONFIG_COCOA)
1233 "\t\"-display cocoa\"\n"
1234#elif defined(CONFIG_VNC)
1235 "\t\"-vnc localhost:0,to=99,id=default\"\n"
1236#else
1237 "\t\"-display none\"\n"
1238#endif
1239 , QEMU_ARCH_ALL)
1240STEXI
1241@item -display @var{type}
1242@findex -display
1243Select type of display to use. This option is a replacement for the
1244old style -sdl/-curses/... options. Valid values for @var{type} are
1245@table @option
1246@item sdl
1247Display video output via SDL (usually in a separate graphics
1248window; see the SDL documentation for other possibilities).
1249@item curses
1250Display video output via curses. For graphics device models which
1251support a text mode, QEMU can display this output using a
1252curses/ncurses interface. Nothing is displayed when the graphics
1253device is in graphical mode or if the graphics device does not support
1254a text mode. Generally only the VGA device models support text mode.
1255@item none
1256Do not display video output. The guest will still see an emulated
1257graphics card, but its output will not be displayed to the QEMU
1258user. This option differs from the -nographic option in that it
1259only affects what is done with video output; -nographic also changes
1260the destination of the serial and parallel port data.
1261@item gtk
1262Display video output in a GTK window. This interface provides drop-down
1263menus and other UI elements to configure and control the VM during
1264runtime.
1265@item vnc
1266Start a VNC server on display <arg>
1267@end table
1268ETEXI
1269
1270DEF("nographic", 0, QEMU_OPTION_nographic,
1271 "-nographic disable graphical output and redirect serial I/Os to console\n",
1272 QEMU_ARCH_ALL)
1273STEXI
1274@item -nographic
1275@findex -nographic
1276Normally, if QEMU is compiled with graphical window support, it displays
1277output such as guest graphics, guest console, and the QEMU monitor in a
1278window. With this option, you can totally disable graphical output so
1279that QEMU is a simple command line application. The emulated serial port
1280is redirected on the console and muxed with the monitor (unless
1281redirected elsewhere explicitly). Therefore, you can still use QEMU to
1282debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1283switching between the console and monitor.
1284ETEXI
1285
1286DEF("curses", 0, QEMU_OPTION_curses,
1287 "-curses shorthand for -display curses\n",
1288 QEMU_ARCH_ALL)
1289STEXI
1290@item -curses
1291@findex -curses
1292Normally, if QEMU is compiled with graphical window support, it displays
1293output such as guest graphics, guest console, and the QEMU monitor in a
1294window. With this option, QEMU can display the VGA output when in text
1295mode using a curses/ncurses interface. Nothing is displayed in graphical
1296mode.
1297ETEXI
1298
1299DEF("no-frame", 0, QEMU_OPTION_no_frame,
1300 "-no-frame open SDL window without a frame and window decorations\n",
1301 QEMU_ARCH_ALL)
1302STEXI
1303@item -no-frame
1304@findex -no-frame
1305Do not use decorations for SDL windows and start them using the whole
1306available screen space. This makes the using QEMU in a dedicated desktop
1307workspace more convenient.
1308ETEXI
1309
1310DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1311 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1312 QEMU_ARCH_ALL)
1313STEXI
1314@item -alt-grab
1315@findex -alt-grab
1316Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1317affects the special keys (for fullscreen, monitor-mode switching, etc).
1318ETEXI
1319
1320DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1321 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1322 QEMU_ARCH_ALL)
1323STEXI
1324@item -ctrl-grab
1325@findex -ctrl-grab
1326Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1327affects the special keys (for fullscreen, monitor-mode switching, etc).
1328ETEXI
1329
1330DEF("no-quit", 0, QEMU_OPTION_no_quit,
1331 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
1332STEXI
1333@item -no-quit
1334@findex -no-quit
1335Disable SDL window close capability.
1336ETEXI
1337
1338DEF("sdl", 0, QEMU_OPTION_sdl,
1339 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL)
1340STEXI
1341@item -sdl
1342@findex -sdl
1343Enable SDL.
1344ETEXI
1345
1346DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1347 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1348 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1349 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1350 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1351 " [,tls-ciphers=<list>]\n"
1352 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1353 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1354 " [,sasl][,password=<secret>][,disable-ticketing]\n"
1355 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1356 " [,jpeg-wan-compression=[auto|never|always]]\n"
1357 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
1358 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1359 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1360 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1361 " [,gl=[on|off]][,rendernode=<file>]\n"
1362 " enable spice\n"
1363 " at least one of {port, tls-port} is mandatory\n",
1364 QEMU_ARCH_ALL)
1365STEXI
1366@item -spice @var{option}[,@var{option}[,...]]
1367@findex -spice
1368Enable the spice remote desktop protocol. Valid options are
1369
1370@table @option
1371
1372@item port=<nr>
1373Set the TCP port spice is listening on for plaintext channels.
1374
1375@item addr=<addr>
1376Set the IP address spice is listening on. Default is any address.
1377
1378@item ipv4
1379@itemx ipv6
1380@itemx unix
1381Force using the specified IP version.
1382
1383@item password=<secret>
1384Set the password you need to authenticate.
1385
1386@item sasl
1387Require that the client use SASL to authenticate with the spice.
1388The exact choice of authentication method used is controlled from the
1389system / user's SASL configuration file for the 'qemu' service. This
1390is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1391unprivileged user, an environment variable SASL_CONF_PATH can be used
1392to make it search alternate locations for the service config.
1393While some SASL auth methods can also provide data encryption (eg GSSAPI),
1394it is recommended that SASL always be combined with the 'tls' and
1395'x509' settings to enable use of SSL and server certificates. This
1396ensures a data encryption preventing compromise of authentication
1397credentials.
1398
1399@item disable-ticketing
1400Allow client connects without authentication.
1401
1402@item disable-copy-paste
1403Disable copy paste between the client and the guest.
1404
1405@item disable-agent-file-xfer
1406Disable spice-vdagent based file-xfer between the client and the guest.
1407
1408@item tls-port=<nr>
1409Set the TCP port spice is listening on for encrypted channels.
1410
1411@item x509-dir=<dir>
1412Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1413
1414@item x509-key-file=<file>
1415@itemx x509-key-password=<file>
1416@itemx x509-cert-file=<file>
1417@itemx x509-cacert-file=<file>
1418@itemx x509-dh-key-file=<file>
1419The x509 file names can also be configured individually.
1420
1421@item tls-ciphers=<list>
1422Specify which ciphers to use.
1423
1424@item tls-channel=[main|display|cursor|inputs|record|playback]
1425@itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1426Force specific channel to be used with or without TLS encryption. The
1427options can be specified multiple times to configure multiple
1428channels. The special name "default" can be used to set the default
1429mode. For channels which are not explicitly forced into one mode the
1430spice client is allowed to pick tls/plaintext as he pleases.
1431
1432@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1433Configure image compression (lossless).
1434Default is auto_glz.
1435
1436@item jpeg-wan-compression=[auto|never|always]
1437@itemx zlib-glz-wan-compression=[auto|never|always]
1438Configure wan image compression (lossy for slow links).
1439Default is auto.
1440
1441@item streaming-video=[off|all|filter]
1442Configure video stream detection. Default is off.
1443
1444@item agent-mouse=[on|off]
1445Enable/disable passing mouse events via vdagent. Default is on.
1446
1447@item playback-compression=[on|off]
1448Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1449
1450@item seamless-migration=[on|off]
1451Enable/disable spice seamless migration. Default is off.
1452
1453@item gl=[on|off]
1454Enable/disable OpenGL context. Default is off.
1455
1456@item rendernode=<file>
1457DRM render node for OpenGL rendering. If not specified, it will pick
1458the first available. (Since 2.9)
1459
1460@end table
1461ETEXI
1462
1463DEF("portrait", 0, QEMU_OPTION_portrait,
1464 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1465 QEMU_ARCH_ALL)
1466STEXI
1467@item -portrait
1468@findex -portrait
1469Rotate graphical output 90 deg left (only PXA LCD).
1470ETEXI
1471
1472DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1473 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1474 QEMU_ARCH_ALL)
1475STEXI
1476@item -rotate @var{deg}
1477@findex -rotate
1478Rotate graphical output some deg left (only PXA LCD).
1479ETEXI
1480
1481DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1482 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1483 " select video card type\n", QEMU_ARCH_ALL)
1484STEXI
1485@item -vga @var{type}
1486@findex -vga
1487Select type of VGA card to emulate. Valid values for @var{type} are
1488@table @option
1489@item cirrus
1490Cirrus Logic GD5446 Video card. All Windows versions starting from
1491Windows 95 should recognize and use this graphic card. For optimal
1492performances, use 16 bit color depth in the guest and the host OS.
1493(This card was the default before QEMU 2.2)
1494@item std
1495Standard VGA card with Bochs VBE extensions. If your guest OS
1496supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1497to use high resolution modes (>= 1280x1024x16) then you should use
1498this option. (This card is the default since QEMU 2.2)
1499@item vmware
1500VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1501recent XFree86/XOrg server or Windows guest with a driver for this
1502card.
1503@item qxl
1504QXL paravirtual graphic card. It is VGA compatible (including VESA
15052.0 VBE support). Works best with qxl guest drivers installed though.
1506Recommended choice when using the spice protocol.
1507@item tcx
1508(sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1509sun4m machines and offers both 8-bit and 24-bit colour depths at a
1510fixed resolution of 1024x768.
1511@item cg3
1512(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1513for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1514resolutions aimed at people wishing to run older Solaris versions.
1515@item virtio
1516Virtio VGA card.
1517@item none
1518Disable VGA card.
1519@end table
1520ETEXI
1521
1522DEF("full-screen", 0, QEMU_OPTION_full_screen,
1523 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1524STEXI
1525@item -full-screen
1526@findex -full-screen
1527Start in full screen.
1528ETEXI
1529
1530DEF("g", 1, QEMU_OPTION_g ,
1531 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1532 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1533STEXI
1534@item -g @var{width}x@var{height}[x@var{depth}]
1535@findex -g
1536Set the initial graphical resolution and depth (PPC, SPARC only).
1537ETEXI
1538
1539DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1540 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1541STEXI
1542@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1543@findex -vnc
1544Normally, if QEMU is compiled with graphical window support, it displays
1545output such as guest graphics, guest console, and the QEMU monitor in a
1546window. With this option, you can have QEMU listen on VNC display
1547@var{display} and redirect the VGA display over the VNC session. It is
1548very useful to enable the usb tablet device when using this option
1549(option @option{-device usb-tablet}). When using the VNC display, you
1550must use the @option{-k} parameter to set the keyboard layout if you are
1551not using en-us. Valid syntax for the @var{display} is
1552
1553@table @option
1554
1555@item to=@var{L}
1556
1557With this option, QEMU will try next available VNC @var{display}s, until the
1558number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1559available, e.g. port 5900+@var{display} is already used by another
1560application. By default, to=0.
1561
1562@item @var{host}:@var{d}
1563
1564TCP connections will only be allowed from @var{host} on display @var{d}.
1565By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1566be omitted in which case the server will accept connections from any host.
1567
1568@item unix:@var{path}
1569
1570Connections will be allowed over UNIX domain sockets where @var{path} is the
1571location of a unix socket to listen for connections on.
1572
1573@item none
1574
1575VNC is initialized but not started. The monitor @code{change} command
1576can be used to later start the VNC server.
1577
1578@end table
1579
1580Following the @var{display} value there may be one or more @var{option} flags
1581separated by commas. Valid options are
1582
1583@table @option
1584
1585@item reverse
1586
1587Connect to a listening VNC client via a ``reverse'' connection. The
1588client is specified by the @var{display}. For reverse network
1589connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1590is a TCP port number, not a display number.
1591
1592@item websocket
1593
1594Opens an additional TCP listening port dedicated to VNC Websocket connections.
1595If a bare @var{websocket} option is given, the Websocket port is
15965700+@var{display}. An alternative port can be specified with the
1597syntax @code{websocket}=@var{port}.
1598
1599If @var{host} is specified connections will only be allowed from this host.
1600It is possible to control the websocket listen address independently, using
1601the syntax @code{websocket}=@var{host}:@var{port}.
1602
1603If no TLS credentials are provided, the websocket connection runs in
1604unencrypted mode. If TLS credentials are provided, the websocket connection
1605requires encrypted client connections.
1606
1607@item password
1608
1609Require that password based authentication is used for client connections.
1610
1611The password must be set separately using the @code{set_password} command in
1612the @ref{pcsys_monitor}. The syntax to change your password is:
1613@code{set_password <protocol> <password>} where <protocol> could be either
1614"vnc" or "spice".
1615
1616If you would like to change <protocol> password expiration, you should use
1617@code{expire_password <protocol> <expiration-time>} where expiration time could
1618be one of the following options: now, never, +seconds or UNIX time of
1619expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1620to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1621date and time).
1622
1623You can also use keywords "now" or "never" for the expiration time to
1624allow <protocol> password to expire immediately or never expire.
1625
1626@item tls-creds=@var{ID}
1627
1628Provides the ID of a set of TLS credentials to use to secure the
1629VNC server. They will apply to both the normal VNC server socket
1630and the websocket socket (if enabled). Setting TLS credentials
1631will cause the VNC server socket to enable the VeNCrypt auth
1632mechanism. The credentials should have been previously created
1633using the @option{-object tls-creds} argument.
1634
1635The @option{tls-creds} parameter obsoletes the @option{tls},
1636@option{x509}, and @option{x509verify} options, and as such
1637it is not permitted to set both new and old type options at
1638the same time.
1639
1640@item tls
1641
1642Require that client use TLS when communicating with the VNC server. This
1643uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1644attack. It is recommended that this option be combined with either the
1645@option{x509} or @option{x509verify} options.
1646
1647This option is now deprecated in favor of using the @option{tls-creds}
1648argument.
1649
1650@item x509=@var{/path/to/certificate/dir}
1651
1652Valid if @option{tls} is specified. Require that x509 credentials are used
1653for negotiating the TLS session. The server will send its x509 certificate
1654to the client. It is recommended that a password be set on the VNC server
1655to provide authentication of the client when this is used. The path following
1656this option specifies where the x509 certificates are to be loaded from.
1657See the @ref{vnc_security} section for details on generating certificates.
1658
1659This option is now deprecated in favour of using the @option{tls-creds}
1660argument.
1661
1662@item x509verify=@var{/path/to/certificate/dir}
1663
1664Valid if @option{tls} is specified. Require that x509 credentials are used
1665for negotiating the TLS session. The server will send its x509 certificate
1666to the client, and request that the client send its own x509 certificate.
1667The server will validate the client's certificate against the CA certificate,
1668and reject clients when validation fails. If the certificate authority is
1669trusted, this is a sufficient authentication mechanism. You may still wish
1670to set a password on the VNC server as a second authentication layer. The
1671path following this option specifies where the x509 certificates are to
1672be loaded from. See the @ref{vnc_security} section for details on generating
1673certificates.
1674
1675This option is now deprecated in favour of using the @option{tls-creds}
1676argument.
1677
1678@item sasl
1679
1680Require that the client use SASL to authenticate with the VNC server.
1681The exact choice of authentication method used is controlled from the
1682system / user's SASL configuration file for the 'qemu' service. This
1683is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1684unprivileged user, an environment variable SASL_CONF_PATH can be used
1685to make it search alternate locations for the service config.
1686While some SASL auth methods can also provide data encryption (eg GSSAPI),
1687it is recommended that SASL always be combined with the 'tls' and
1688'x509' settings to enable use of SSL and server certificates. This
1689ensures a data encryption preventing compromise of authentication
1690credentials. See the @ref{vnc_security} section for details on using
1691SASL authentication.
1692
1693@item acl
1694
1695Turn on access control lists for checking of the x509 client certificate
1696and SASL party. For x509 certs, the ACL check is made against the
1697certificate's distinguished name. This is something that looks like
1698@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1699made against the username, which depending on the SASL plugin, may
1700include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1701When the @option{acl} flag is set, the initial access list will be
1702empty, with a @code{deny} policy. Thus no one will be allowed to
1703use the VNC server until the ACLs have been loaded. This can be
1704achieved using the @code{acl} monitor command.
1705
1706@item lossy
1707
1708Enable lossy compression methods (gradient, JPEG, ...). If this
1709option is set, VNC client may receive lossy framebuffer updates
1710depending on its encoding settings. Enabling this option can save
1711a lot of bandwidth at the expense of quality.
1712
1713@item non-adaptive
1714
1715Disable adaptive encodings. Adaptive encodings are enabled by default.
1716An adaptive encoding will try to detect frequently updated screen regions,
1717and send updates in these regions using a lossy encoding (like JPEG).
1718This can be really helpful to save bandwidth when playing videos. Disabling
1719adaptive encodings restores the original static behavior of encodings
1720like Tight.
1721
1722@item share=[allow-exclusive|force-shared|ignore]
1723
1724Set display sharing policy. 'allow-exclusive' allows clients to ask
1725for exclusive access. As suggested by the rfb spec this is
1726implemented by dropping other connections. Connecting multiple
1727clients in parallel requires all clients asking for a shared session
1728(vncviewer: -shared switch). This is the default. 'force-shared'
1729disables exclusive client access. Useful for shared desktop sessions,
1730where you don't want someone forgetting specify -shared disconnect
1731everybody else. 'ignore' completely ignores the shared flag and
1732allows everybody connect unconditionally. Doesn't conform to the rfb
1733spec but is traditional QEMU behavior.
1734
1735@item key-delay-ms
1736
1737Set keyboard delay, for key down and key up events, in milliseconds.
1738Default is 10. Keyboards are low-bandwidth devices, so this slowdown
1739can help the device and guest to keep up and not lose events in case
1740events are arriving in bulk. Possible causes for the latter are flaky
1741network connections, or scripts for automated testing.
1742
1743@end table
1744ETEXI
1745
1746STEXI
1747@end table
1748ETEXI
1749ARCHHEADING(, QEMU_ARCH_I386)
1750
1751ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1752STEXI
1753@table @option
1754ETEXI
1755
1756DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1757 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1758 QEMU_ARCH_I386)
1759STEXI
1760@item -win2k-hack
1761@findex -win2k-hack
1762Use it when installing Windows 2000 to avoid a disk full bug. After
1763Windows 2000 is installed, you no longer need this option (this option
1764slows down the IDE transfers).
1765ETEXI
1766
1767HXCOMM Deprecated by -rtc
1768DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1769
1770DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1771 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1772 QEMU_ARCH_I386)
1773STEXI
1774@item -no-fd-bootchk
1775@findex -no-fd-bootchk
1776Disable boot signature checking for floppy disks in BIOS. May
1777be needed to boot from old floppy disks.
1778ETEXI
1779
1780DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1781 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1782STEXI
1783@item -no-acpi
1784@findex -no-acpi
1785Disable ACPI (Advanced Configuration and Power Interface) support. Use
1786it if your guest OS complains about ACPI problems (PC target machine
1787only).
1788ETEXI
1789
1790DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1791 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1792STEXI
1793@item -no-hpet
1794@findex -no-hpet
1795Disable HPET support.
1796ETEXI
1797
1798DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1799 "-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"
1800 " ACPI table description\n", QEMU_ARCH_I386)
1801STEXI
1802@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}]...]
1803@findex -acpitable
1804Add ACPI table with specified header fields and context from specified files.
1805For file=, take whole ACPI table from the specified files, including all
1806ACPI headers (possible overridden by other options).
1807For data=, only data
1808portion of the table is used, all header information is specified in the
1809command line.
1810If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1811fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1812to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1813spec.
1814ETEXI
1815
1816DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1817 "-smbios file=binary\n"
1818 " load SMBIOS entry from binary file\n"
1819 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1820 " [,uefi=on|off]\n"
1821 " specify SMBIOS type 0 fields\n"
1822 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1823 " [,uuid=uuid][,sku=str][,family=str]\n"
1824 " specify SMBIOS type 1 fields\n"
1825 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1826 " [,asset=str][,location=str]\n"
1827 " specify SMBIOS type 2 fields\n"
1828 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1829 " [,sku=str]\n"
1830 " specify SMBIOS type 3 fields\n"
1831 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1832 " [,asset=str][,part=str]\n"
1833 " specify SMBIOS type 4 fields\n"
1834 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1835 " [,asset=str][,part=str][,speed=%d]\n"
1836 " specify SMBIOS type 17 fields\n",
1837 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1838STEXI
1839@item -smbios file=@var{binary}
1840@findex -smbios
1841Load SMBIOS entry from binary file.
1842
1843@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1844Specify SMBIOS type 0 fields
1845
1846@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}]
1847Specify SMBIOS type 1 fields
1848
1849@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}]
1850Specify SMBIOS type 2 fields
1851
1852@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1853Specify SMBIOS type 3 fields
1854
1855@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1856Specify SMBIOS type 4 fields
1857
1858@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}]
1859Specify SMBIOS type 17 fields
1860ETEXI
1861
1862STEXI
1863@end table
1864ETEXI
1865DEFHEADING()
1866
1867DEFHEADING(Network options:)
1868STEXI
1869@table @option
1870ETEXI
1871
1872HXCOMM Legacy slirp options (now moved to -net user):
1873#ifdef CONFIG_SLIRP
1874DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1875DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1876DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1877#ifndef _WIN32
1878DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1879#endif
1880#endif
1881
1882DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1883#ifdef CONFIG_SLIRP
1884 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1885 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1886 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1887 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
1888 " [,tftp=dir][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1889#ifndef _WIN32
1890 "[,smb=dir[,smbserver=addr]]\n"
1891#endif
1892 " configure a user mode network backend with ID 'str',\n"
1893 " its DHCP server and optional services\n"
1894#endif
1895#ifdef _WIN32
1896 "-netdev tap,id=str,ifname=name\n"
1897 " configure a host TAP network backend with ID 'str'\n"
1898#else
1899 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1900 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1901 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1902 " [,poll-us=n]\n"
1903 " configure a host TAP network backend with ID 'str'\n"
1904 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1905 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1906 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1907 " to deconfigure it\n"
1908 " use '[down]script=no' to disable script execution\n"
1909 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1910 " configure it\n"
1911 " use 'fd=h' to connect to an already opened TAP interface\n"
1912 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1913 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1914 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1915 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1916 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1917 " use vhost=on to enable experimental in kernel accelerator\n"
1918 " (only has effect for virtio guests which use MSIX)\n"
1919 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1920 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
1921 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1922 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1923 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1924 " spent on busy polling for vhost net\n"
1925 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1926 " configure a host TAP network backend with ID 'str' that is\n"
1927 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1928 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1929#endif
1930#ifdef __linux__
1931 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1932 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1933 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1934 " [,rxcookie=rxcookie][,offset=offset]\n"
1935 " configure a network backend with ID 'str' connected to\n"
1936 " an Ethernet over L2TPv3 pseudowire.\n"
1937 " Linux kernel 3.3+ as well as most routers can talk\n"
1938 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1939 " VM to a router and even VM to Host. It is a nearly-universal\n"
1940 " standard (RFC3391). Note - this implementation uses static\n"
1941 " pre-configured tunnels (same as the Linux kernel).\n"
1942 " use 'src=' to specify source address\n"
1943 " use 'dst=' to specify destination address\n"
1944 " use 'udp=on' to specify udp encapsulation\n"
1945 " use 'srcport=' to specify source udp port\n"
1946 " use 'dstport=' to specify destination udp port\n"
1947 " use 'ipv6=on' to force v6\n"
1948 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1949 " well as a weak security measure\n"
1950 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
1951 " use 'txcookie=0x012345678' to specify a txcookie\n"
1952 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1953 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1954 " use 'pincounter=on' to work around broken counter handling in peer\n"
1955 " use 'offset=X' to add an extra offset between header and data\n"
1956#endif
1957 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1958 " configure a network backend to connect to another network\n"
1959 " using a socket connection\n"
1960 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1961 " configure a network backend to connect to a multicast maddr and port\n"
1962 " use 'localaddr=addr' to specify the host address to send packets from\n"
1963 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1964 " configure a network backend to connect to another network\n"
1965 " using an UDP tunnel\n"
1966#ifdef CONFIG_VDE
1967 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1968 " configure a network backend to connect to port 'n' of a vde switch\n"
1969 " running on host and listening for incoming connections on 'socketpath'.\n"
1970 " Use group 'groupname' and mode 'octalmode' to change default\n"
1971 " ownership and permissions for communication port.\n"
1972#endif
1973#ifdef CONFIG_NETMAP
1974 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1975 " attach to the existing netmap-enabled network interface 'name', or to a\n"
1976 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1977 " netmap device, defaults to '/dev/netmap')\n"
1978#endif
1979#ifdef CONFIG_POSIX
1980 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1981 " configure a vhost-user network, backed by a chardev 'dev'\n"
1982#endif
1983 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
1984 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
1985DEF("nic", HAS_ARG, QEMU_OPTION_nic,
1986 "-nic [tap|bridge|"
1987#ifdef CONFIG_SLIRP
1988 "user|"
1989#endif
1990#ifdef __linux__
1991 "l2tpv3|"
1992#endif
1993#ifdef CONFIG_VDE
1994 "vde|"
1995#endif
1996#ifdef CONFIG_NETMAP
1997 "netmap|"
1998#endif
1999#ifdef CONFIG_POSIX
2000 "vhost-user|"
2001#endif
2002 "socket][,option][,...][mac=macaddr]\n"
2003 " initialize an on-board / default host NIC (using MAC address\n"
2004 " macaddr) and connect it to the given host network backend\n"
2005 "-nic none use it alone to have zero network devices (the default is to\n"
2006 " provided a 'user' network connection)\n",
2007 QEMU_ARCH_ALL)
2008DEF("net", HAS_ARG, QEMU_OPTION_net,
2009 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
2010 " configure or create an on-board (or machine default) NIC and\n"
2011 " connect it to hub 0 (please use -nic unless you need a hub)\n"
2012 "-net ["
2013#ifdef CONFIG_SLIRP
2014 "user|"
2015#endif
2016 "tap|"
2017 "bridge|"
2018#ifdef CONFIG_VDE
2019 "vde|"
2020#endif
2021#ifdef CONFIG_NETMAP
2022 "netmap|"
2023#endif
2024 "socket][,option][,option][,...]\n"
2025 " old way to initialize a host network interface\n"
2026 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2027STEXI
2028@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]
2029@findex -nic
2030This option is a shortcut for configuring both the on-board (default) guest
2031NIC hardware and the host network backend in one go. The host backend options
2032are the same as with the corresponding @option{-netdev} options below.
2033The guest NIC model can be set with @option{model=@var{modelname}}.
2034Use @option{model=help} to list the available device types.
2035The hardware MAC address can be set with @option{mac=@var{macaddr}}.
2036
2037The following two example do exactly the same, to show how @option{-nic} can
2038be used to shorten the command line length (note that the e1000 is the default
2039on i386, so the @option{model=e1000} parameter could even be omitted here, too):
2040@example
2041qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
2042qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2043@end example
2044
2045@item -nic none
2046Indicate that no network devices should be configured. It is used to override
2047the default configuration (default NIC with ``user'' host network backend)
2048which is activated if no other networking options are provided.
2049
2050@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2051@findex -netdev
2052Configure user mode host network backend which requires no administrator
2053privilege to run. Valid options are:
2054
2055@table @option
2056@item id=@var{id}
2057Assign symbolic name for use in monitor commands.
2058
2059@item ipv4=on|off and ipv6=on|off
2060Specify that either IPv4 or IPv6 must be enabled. If neither is specified
2061both protocols are enabled.
2062
2063@item net=@var{addr}[/@var{mask}]
2064Set IP network address the guest will see. Optionally specify the netmask,
2065either in the form a.b.c.d or as number of valid top-most bits. Default is
206610.0.2.0/24.
2067
2068@item host=@var{addr}
2069Specify the guest-visible address of the host. Default is the 2nd IP in the
2070guest network, i.e. x.x.x.2.
2071
2072@item ipv6-net=@var{addr}[/@var{int}]
2073Set IPv6 network address the guest will see (default is fec0::/64). The
2074network prefix is given in the usual hexadecimal IPv6 address
2075notation. The prefix size is optional, and is given as the number of
2076valid top-most bits (default is 64).
2077
2078@item ipv6-host=@var{addr}
2079Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2080the guest network, i.e. xxxx::2.
2081
2082@item restrict=on|off
2083If this option is enabled, the guest will be isolated, i.e. it will not be
2084able to contact the host and no guest IP packets will be routed over the host
2085to the outside. This option does not affect any explicitly set forwarding rules.
2086
2087@item hostname=@var{name}
2088Specifies the client hostname reported by the built-in DHCP server.
2089
2090@item dhcpstart=@var{addr}
2091Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2092is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2093
2094@item dns=@var{addr}
2095Specify the guest-visible address of the virtual nameserver. The address must
2096be different from the host address. Default is the 3rd IP in the guest network,
2097i.e. x.x.x.3.
2098
2099@item ipv6-dns=@var{addr}
2100Specify the guest-visible address of the IPv6 virtual nameserver. The address
2101must be different from the host address. Default is the 3rd IP in the guest
2102network, i.e. xxxx::3.
2103
2104@item dnssearch=@var{domain}
2105Provides an entry for the domain-search list sent by the built-in
2106DHCP server. More than one domain suffix can be transmitted by specifying
2107this option multiple times. If supported, this will cause the guest to
2108automatically try to append the given domain suffix(es) in case a domain name
2109can not be resolved.
2110
2111Example:
2112@example
2113qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2114@end example
2115
2116@item domainname=@var{domain}
2117Specifies the client domain name reported by the built-in DHCP server.
2118
2119@item tftp=@var{dir}
2120When using the user mode network stack, activate a built-in TFTP
2121server. The files in @var{dir} will be exposed as the root of a TFTP server.
2122The TFTP client on the guest must be configured in binary mode (use the command
2123@code{bin} of the Unix TFTP client).
2124
2125@item bootfile=@var{file}
2126When using the user mode network stack, broadcast @var{file} as the BOOTP
2127filename. In conjunction with @option{tftp}, this can be used to network boot
2128a guest from a local directory.
2129
2130Example (using pxelinux):
2131@example
2132qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2133 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2134@end example
2135
2136@item smb=@var{dir}[,smbserver=@var{addr}]
2137When using the user mode network stack, activate a built-in SMB
2138server so that Windows OSes can access to the host files in @file{@var{dir}}
2139transparently. The IP address of the SMB server can be set to @var{addr}. By
2140default the 4th IP in the guest network is used, i.e. x.x.x.4.
2141
2142In the guest Windows OS, the line:
2143@example
214410.0.2.4 smbserver
2145@end example
2146must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2147or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2148
2149Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2150
2151Note that a SAMBA server must be installed on the host OS.
2152
2153@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2154Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2155the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2156@var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2157given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2158be bound to a specific host interface. If no connection type is set, TCP is
2159used. This option can be given multiple times.
2160
2161For example, to redirect host X11 connection from screen 1 to guest
2162screen 0, use the following:
2163
2164@example
2165# on the host
2166qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2167# this host xterm should open in the guest X11 server
2168xterm -display :1
2169@end example
2170
2171To redirect telnet connections from host port 5555 to telnet port on
2172the guest, use the following:
2173
2174@example
2175# on the host
2176qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2177telnet localhost 5555
2178@end example
2179
2180Then when you use on the host @code{telnet localhost 5555}, you
2181connect to the guest telnet server.
2182
2183@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2184@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2185Forward guest TCP connections to the IP address @var{server} on port @var{port}
2186to the character device @var{dev} or to a program executed by @var{cmd:command}
2187which gets spawned for each connection. This option can be given multiple times.
2188
2189You can either use a chardev directly and have that one used throughout QEMU's
2190lifetime, like in the following example:
2191
2192@example
2193# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2194# the guest accesses it
2195qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
2196@end example
2197
2198Or you can execute a command on every TCP connection established by the guest,
2199so that QEMU behaves similar to an inetd process for that virtual server:
2200
2201@example
2202# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2203# and connect the TCP stream to its stdin/stdout
2204qemu-system-i386 -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2205@end example
2206
2207@end table
2208
2209Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2210processed and applied to -net user. Mixing them with the new configuration
2211syntax gives undefined results. Their use for new applications is discouraged
2212as they will be removed from future versions.
2213
2214@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2215Configure a host TAP network backend with ID @var{id}.
2216
2217Use the network script @var{file} to configure it and the network script
2218@var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2219automatically provides one. The default network configure script is
2220@file{/etc/qemu-ifup} and the default network deconfigure script is
2221@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2222to disable script execution.
2223
2224If running QEMU as an unprivileged user, use the network helper
2225@var{helper} to configure the TAP interface and attach it to the bridge.
2226The default network helper executable is @file{/path/to/qemu-bridge-helper}
2227and the default bridge device is @file{br0}.
2228
2229@option{fd}=@var{h} can be used to specify the handle of an already
2230opened host TAP interface.
2231
2232Examples:
2233
2234@example
2235#launch a QEMU instance with the default network script
2236qemu-system-i386 linux.img -nic tap
2237@end example
2238
2239@example
2240#launch a QEMU instance with two NICs, each one connected
2241#to a TAP device
2242qemu-system-i386 linux.img \
2243 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2244 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2245@end example
2246
2247@example
2248#launch a QEMU instance with the default network helper to
2249#connect a TAP device to bridge br0
2250qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \
2251 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
2252@end example
2253
2254@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2255Connect a host TAP network interface to a host bridge device.
2256
2257Use the network helper @var{helper} to configure the TAP interface and
2258attach it to the bridge. The default network helper executable is
2259@file{/path/to/qemu-bridge-helper} and the default bridge
2260device is @file{br0}.
2261
2262Examples:
2263
2264@example
2265#launch a QEMU instance with the default network helper to
2266#connect a TAP device to bridge br0
2267qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
2268@end example
2269
2270@example
2271#launch a QEMU instance with the default network helper to
2272#connect a TAP device to bridge qemubr0
2273qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
2274@end example
2275
2276@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2277
2278This host network backend can be used to connect the guest's network to
2279another QEMU virtual machine using a TCP socket connection. If @option{listen}
2280is specified, QEMU waits for incoming connections on @var{port}
2281(@var{host} is optional). @option{connect} is used to connect to
2282another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2283specifies an already opened TCP socket.
2284
2285Example:
2286@example
2287# launch a first QEMU instance
2288qemu-system-i386 linux.img \
2289 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2290 -netdev socket,id=n1,listen=:1234
2291# connect the network of this instance to the network of the first instance
2292qemu-system-i386 linux.img \
2293 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2294 -netdev socket,id=n2,connect=127.0.0.1:1234
2295@end example
2296
2297@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2298
2299Configure a socket host network backend to share the guest's network traffic
2300with another QEMU virtual machines using a UDP multicast socket, effectively
2301making a bus for every QEMU with same multicast address @var{maddr} and @var{port}.
2302NOTES:
2303@enumerate
2304@item
2305Several QEMU can be running on different hosts and share same bus (assuming
2306correct multicast setup for these hosts).
2307@item
2308mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2309@url{http://user-mode-linux.sf.net}.
2310@item
2311Use @option{fd=h} to specify an already opened UDP multicast socket.
2312@end enumerate
2313
2314Example:
2315@example
2316# launch one QEMU instance
2317qemu-system-i386 linux.img \
2318 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2319 -netdev socket,id=n1,mcast=230.0.0.1:1234
2320# launch another QEMU instance on same "bus"
2321qemu-system-i386 linux.img \
2322 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2323 -netdev socket,id=n2,mcast=230.0.0.1:1234
2324# launch yet another QEMU instance on same "bus"
2325qemu-system-i386 linux.img \
2326 -device e1000,netdev=n3,macaddr=52:54:00:12:34:58 \
2327 -netdev socket,id=n3,mcast=230.0.0.1:1234
2328@end example
2329
2330Example (User Mode Linux compat.):
2331@example
2332# launch QEMU instance (note mcast address selected is UML's default)
2333qemu-system-i386 linux.img \
2334 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2335 -netdev socket,id=n1,mcast=239.192.168.1:1102
2336# launch UML
2337/path/to/linux ubd0=/path/to/root_fs eth0=mcast
2338@end example
2339
2340Example (send packets from host's 1.2.3.4):
2341@example
2342qemu-system-i386 linux.img \
2343 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2344 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2345@end example
2346
2347@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}]
2348Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a
2349popular protocol to transport Ethernet (and other Layer 2) data frames between
2350two systems. It is present in routers, firewalls and the Linux kernel
2351(from version 3.3 onwards).
2352
2353This transport allows a VM to communicate to another VM, router or firewall directly.
2354
2355@table @option
2356@item src=@var{srcaddr}
2357 source address (mandatory)
2358@item dst=@var{dstaddr}
2359 destination address (mandatory)
2360@item udp
2361 select udp encapsulation (default is ip).
2362@item srcport=@var{srcport}
2363 source udp port.
2364@item dstport=@var{dstport}
2365 destination udp port.
2366@item ipv6
2367 force v6, otherwise defaults to v4.
2368@item rxcookie=@var{rxcookie}
2369@itemx txcookie=@var{txcookie}
2370 Cookies are a weak form of security in the l2tpv3 specification.
2371Their function is mostly to prevent misconfiguration. By default they are 32
2372bit.
2373@item cookie64
2374 Set cookie size to 64 bit instead of the default 32
2375@item counter=off
2376 Force a 'cut-down' L2TPv3 with no counter as in
2377draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2378@item pincounter=on
2379 Work around broken counter handling in peer. This may also help on
2380networks which have packet reorder.
2381@item offset=@var{offset}
2382 Add an extra offset between header and data
2383@end table
2384
2385For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2386on the remote Linux host 1.2.3.4:
2387@example
2388# Setup tunnel on linux host using raw ip as encapsulation
2389# on 1.2.3.4
2390ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2391 encap udp udp_sport 16384 udp_dport 16384
2392ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2393 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2394ifconfig vmtunnel0 mtu 1500
2395ifconfig vmtunnel0 up
2396brctl addif br-lan vmtunnel0
2397
2398
2399# on 4.3.2.1
2400# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2401
2402qemu-system-i386 linux.img -device e1000,netdev=n1 \
2403 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2404
2405@end example
2406
2407@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2408Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and
2409listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2410and MODE @var{octalmode} to change default ownership and permissions for
2411communication port. This option is only available if QEMU has been compiled
2412with vde support enabled.
2413
2414Example:
2415@example
2416# launch vde switch
2417vde_switch -F -sock /tmp/myswitch
2418# launch QEMU instance
2419qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch
2420@end example
2421
2422@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2423
2424Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2425be a unix domain socket backed one. The vhost-user uses a specifically defined
2426protocol to pass vhost ioctl replacement messages to an application on the other
2427end of the socket. On non-MSIX guests, the feature can be forced with
2428@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2429be created for multiqueue vhost-user.
2430
2431Example:
2432@example
2433qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2434 -numa node,memdev=mem \
2435 -chardev socket,id=chr0,path=/path/to/socket \
2436 -netdev type=vhost-user,id=net0,chardev=chr0 \
2437 -device virtio-net-pci,netdev=net0
2438@end example
2439
2440@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2441
2442Create a hub port on the emulated hub with ID @var{hubid}.
2443
2444The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2445single netdev. Alternatively, you can also connect the hubport to another
2446netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option.
2447
2448@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2449@findex -net
2450Legacy option to configure or create an on-board (or machine default) Network
2451Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e.
2452the default hub), or to the netdev @var{nd}.
2453The NIC is an e1000 by default on the PC target. Optionally, the MAC address
2454can be changed to @var{mac}, the device address set to @var{addr} (PCI cards
2455only), and a @var{name} can be assigned for use in monitor commands.
2456Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2457that the card should have; this option currently only affects virtio cards; set
2458@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2459NIC is created. QEMU can emulate several different models of network card.
2460Use @code{-net nic,model=help} for a list of available devices for your target.
2461
2462@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}]
2463Configure a host network backend (with the options corresponding to the same
2464@option{-netdev} option) and connect it to the emulated hub 0 (the default
2465hub). Use @var{name} to specify the name of the hub port.
2466ETEXI
2467
2468STEXI
2469@end table
2470ETEXI
2471DEFHEADING()
2472
2473DEFHEADING(Character device options:)
2474
2475DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2476 "-chardev help\n"
2477 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2478 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2479 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2480 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2481 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2482 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2483 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2484 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2485 " [,logfile=PATH][,logappend=on|off]\n"
2486 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2487 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2488 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2489 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2490 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2491 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2492#ifdef _WIN32
2493 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2494 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2495#else
2496 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2497 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2498#endif
2499#ifdef CONFIG_BRLAPI
2500 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2501#endif
2502#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2503 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2504 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2505 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2506#endif
2507#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2508 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2509 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2510#endif
2511#if defined(CONFIG_SPICE)
2512 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2513 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2514#endif
2515 , QEMU_ARCH_ALL
2516)
2517
2518STEXI
2519
2520The general form of a character device option is:
2521@table @option
2522@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2523@findex -chardev
2524Backend is one of:
2525@option{null},
2526@option{socket},
2527@option{udp},
2528@option{msmouse},
2529@option{vc},
2530@option{ringbuf},
2531@option{file},
2532@option{pipe},
2533@option{console},
2534@option{serial},
2535@option{pty},
2536@option{stdio},
2537@option{braille},
2538@option{tty},
2539@option{parallel},
2540@option{parport},
2541@option{spicevmc},
2542@option{spiceport}.
2543The specific backend will determine the applicable options.
2544
2545Use @code{-chardev help} to print all available chardev backend types.
2546
2547All devices must have an id, which can be any string up to 127 characters long.
2548It is used to uniquely identify this device in other command line directives.
2549
2550A character device may be used in multiplexing mode by multiple front-ends.
2551Specify @option{mux=on} to enable this mode.
2552A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2553backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2554If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2555create a multiplexer with your specified ID, and you can then configure multiple
2556front ends to use that chardev ID for their input/output. Up to four different
2557front ends can be connected to a single multiplexed chardev. (Without
2558multiplexing enabled, a chardev can only be used by a single front end.)
2559For instance you could use this to allow a single stdio chardev to be used by
2560two serial ports and the QEMU monitor:
2561
2562@example
2563-chardev stdio,mux=on,id=char0 \
2564-mon chardev=char0,mode=readline \
2565-serial chardev:char0 \
2566-serial chardev:char0
2567@end example
2568
2569You can have more than one multiplexer in a system configuration; for instance
2570you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2571multiplexed between the QEMU monitor and a parallel port:
2572
2573@example
2574-chardev stdio,mux=on,id=char0 \
2575-mon chardev=char0,mode=readline \
2576-parallel chardev:char0 \
2577-chardev tcp,...,mux=on,id=char1 \
2578-serial chardev:char1 \
2579-serial chardev:char1
2580@end example
2581
2582When you're using a multiplexed character device, some escape sequences are
2583interpreted in the input. @xref{mux_keys, Keys in the character backend
2584multiplexer}.
2585
2586Note that some other command line options may implicitly create multiplexed
2587character backends; for instance @option{-serial mon:stdio} creates a
2588multiplexed stdio backend connected to the serial port and the QEMU monitor,
2589and @option{-nographic} also multiplexes the console and the monitor to
2590stdio.
2591
2592There is currently no support for multiplexing in the other direction
2593(where a single QEMU front end takes input and output from multiple chardevs).
2594
2595Every backend supports the @option{logfile} option, which supplies the path
2596to a file to record all data transmitted via the backend. The @option{logappend}
2597option controls whether the log file will be truncated or appended to when
2598opened.
2599
2600@end table
2601
2602The available backends are:
2603
2604@table @option
2605@item -chardev null,id=@var{id}
2606A void device. This device will not emit any data, and will drop any data it
2607receives. The null backend does not take any options.
2608
2609@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2610
2611Create a two-way stream socket, which can be either a TCP or a unix socket. A
2612unix socket will be created if @option{path} is specified. Behaviour is
2613undefined if TCP options are specified for a unix socket.
2614
2615@option{server} specifies that the socket shall be a listening socket.
2616
2617@option{nowait} specifies that QEMU should not block waiting for a client to
2618connect to a listening socket.
2619
2620@option{telnet} specifies that traffic on the socket should interpret telnet
2621escape sequences.
2622
2623@option{reconnect} sets the timeout for reconnecting on non-server sockets when
2624the remote end goes away. qemu will delay this many seconds and then attempt
2625to reconnect. Zero disables reconnecting, and is the default.
2626
2627@option{tls-creds} requests enablement of the TLS protocol for encryption,
2628and specifies the id of the TLS credentials to use for the handshake. The
2629credentials must be previously created with the @option{-object tls-creds}
2630argument.
2631
2632TCP and unix socket options are given below:
2633
2634@table @option
2635
2636@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2637
2638@option{host} for a listening socket specifies the local address to be bound.
2639For a connecting socket species the remote host to connect to. @option{host} is
2640optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2641
2642@option{port} for a listening socket specifies the local port to be bound. For a
2643connecting socket specifies the port on the remote host to connect to.
2644@option{port} can be given as either a port number or a service name.
2645@option{port} is required.
2646
2647@option{to} is only relevant to listening sockets. If it is specified, and
2648@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2649to and including @option{to} until it succeeds. @option{to} must be specified
2650as a port number.
2651
2652@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2653If neither is specified the socket may use either protocol.
2654
2655@option{nodelay} disables the Nagle algorithm.
2656
2657@item unix options: path=@var{path}
2658
2659@option{path} specifies the local path of the unix socket. @option{path} is
2660required.
2661
2662@end table
2663
2664@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2665
2666Sends all traffic from the guest to a remote host over UDP.
2667
2668@option{host} specifies the remote host to connect to. If not specified it
2669defaults to @code{localhost}.
2670
2671@option{port} specifies the port on the remote host to connect to. @option{port}
2672is required.
2673
2674@option{localaddr} specifies the local address to bind to. If not specified it
2675defaults to @code{0.0.0.0}.
2676
2677@option{localport} specifies the local port to bind to. If not specified any
2678available local port will be used.
2679
2680@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2681If neither is specified the device may use either protocol.
2682
2683@item -chardev msmouse,id=@var{id}
2684
2685Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2686take any options.
2687
2688@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2689
2690Connect to a QEMU text console. @option{vc} may optionally be given a specific
2691size.
2692
2693@option{width} and @option{height} specify the width and height respectively of
2694the console, in pixels.
2695
2696@option{cols} and @option{rows} specify that the console be sized to fit a text
2697console with the given dimensions.
2698
2699@item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2700
2701Create a ring buffer with fixed size @option{size}.
2702@var{size} must be a power of two and defaults to @code{64K}.
2703
2704@item -chardev file,id=@var{id},path=@var{path}
2705
2706Log all traffic received from the guest to a file.
2707
2708@option{path} specifies the path of the file to be opened. This file will be
2709created if it does not already exist, and overwritten if it does. @option{path}
2710is required.
2711
2712@item -chardev pipe,id=@var{id},path=@var{path}
2713
2714Create a two-way connection to the guest. The behaviour differs slightly between
2715Windows hosts and other hosts:
2716
2717On Windows, a single duplex pipe will be created at
2718@file{\\.pipe\@option{path}}.
2719
2720On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2721@file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2722received by the guest. Data written by the guest can be read from
2723@file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2724be present.
2725
2726@option{path} forms part of the pipe path as described above. @option{path} is
2727required.
2728
2729@item -chardev console,id=@var{id}
2730
2731Send traffic from the guest to QEMU's standard output. @option{console} does not
2732take any options.
2733
2734@option{console} is only available on Windows hosts.
2735
2736@item -chardev serial,id=@var{id},path=@option{path}
2737
2738Send traffic from the guest to a serial device on the host.
2739
2740On Unix hosts serial will actually accept any tty device,
2741not only serial lines.
2742
2743@option{path} specifies the name of the serial device to open.
2744
2745@item -chardev pty,id=@var{id}
2746
2747Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2748not take any options.
2749
2750@option{pty} is not available on Windows hosts.
2751
2752@item -chardev stdio,id=@var{id}[,signal=on|off]
2753Connect to standard input and standard output of the QEMU process.
2754
2755@option{signal} controls if signals are enabled on the terminal, that includes
2756exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2757default, use @option{signal=off} to disable it.
2758
2759@item -chardev braille,id=@var{id}
2760
2761Connect to a local BrlAPI server. @option{braille} does not take any options.
2762
2763@item -chardev tty,id=@var{id},path=@var{path}
2764
2765@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2766DragonFlyBSD hosts. It is an alias for @option{serial}.
2767
2768@option{path} specifies the path to the tty. @option{path} is required.
2769
2770@item -chardev parallel,id=@var{id},path=@var{path}
2771@itemx -chardev parport,id=@var{id},path=@var{path}
2772
2773@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2774
2775Connect to a local parallel port.
2776
2777@option{path} specifies the path to the parallel port device. @option{path} is
2778required.
2779
2780@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2781
2782@option{spicevmc} is only available when spice support is built in.
2783
2784@option{debug} debug level for spicevmc
2785
2786@option{name} name of spice channel to connect to
2787
2788Connect to a spice virtual machine channel, such as vdiport.
2789
2790@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2791
2792@option{spiceport} is only available when spice support is built in.
2793
2794@option{debug} debug level for spicevmc
2795
2796@option{name} name of spice port to connect to
2797
2798Connect to a spice port, allowing a Spice client to handle the traffic
2799identified by a name (preferably a fqdn).
2800ETEXI
2801
2802STEXI
2803@end table
2804ETEXI
2805DEFHEADING()
2806
2807DEFHEADING(Bluetooth(R) options:)
2808STEXI
2809@table @option
2810ETEXI
2811
2812DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2813 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2814 "-bt hci,host[:id]\n" \
2815 " use host's HCI with the given name\n" \
2816 "-bt hci[,vlan=n]\n" \
2817 " emulate a standard HCI in virtual scatternet 'n'\n" \
2818 "-bt vhci[,vlan=n]\n" \
2819 " add host computer to virtual scatternet 'n' using VHCI\n" \
2820 "-bt device:dev[,vlan=n]\n" \
2821 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2822 QEMU_ARCH_ALL)
2823STEXI
2824@item -bt hci[...]
2825@findex -bt
2826Defines the function of the corresponding Bluetooth HCI. -bt options
2827are matched with the HCIs present in the chosen machine type. For
2828example when emulating a machine with only one HCI built into it, only
2829the first @code{-bt hci[...]} option is valid and defines the HCI's
2830logic. The Transport Layer is decided by the machine type. Currently
2831the machines @code{n800} and @code{n810} have one HCI and all other
2832machines have none.
2833
2834@anchor{bt-hcis}
2835The following three types are recognized:
2836
2837@table @option
2838@item -bt hci,null
2839(default) The corresponding Bluetooth HCI assumes no internal logic
2840and will not respond to any HCI commands or emit events.
2841
2842@item -bt hci,host[:@var{id}]
2843(@code{bluez} only) The corresponding HCI passes commands / events
2844to / from the physical HCI identified by the name @var{id} (default:
2845@code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2846capable systems like Linux.
2847
2848@item -bt hci[,vlan=@var{n}]
2849Add a virtual, standard HCI that will participate in the Bluetooth
2850scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2851VLANs, devices inside a bluetooth network @var{n} can only communicate
2852with other devices in the same network (scatternet).
2853@end table
2854
2855@item -bt vhci[,vlan=@var{n}]
2856(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2857to the host bluetooth stack instead of to the emulated target. This
2858allows the host and target machines to participate in a common scatternet
2859and communicate. Requires the Linux @code{vhci} driver installed. Can
2860be used as following:
2861
2862@example
2863qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2864@end example
2865
2866@item -bt device:@var{dev}[,vlan=@var{n}]
2867Emulate a bluetooth device @var{dev} and place it in network @var{n}
2868(default @code{0}). QEMU can only emulate one type of bluetooth devices
2869currently:
2870
2871@table @option
2872@item keyboard
2873Virtual wireless keyboard implementing the HIDP bluetooth profile.
2874@end table
2875ETEXI
2876
2877STEXI
2878@end table
2879ETEXI
2880DEFHEADING()
2881
2882#ifdef CONFIG_TPM
2883DEFHEADING(TPM device options:)
2884
2885DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2886 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2887 " use path to provide path to a character device; default is /dev/tpm0\n"
2888 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2889 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2890 "-tpmdev emulator,id=id,chardev=dev\n"
2891 " configure the TPM device using chardev backend\n",
2892 QEMU_ARCH_ALL)
2893STEXI
2894
2895The general form of a TPM device option is:
2896@table @option
2897
2898@item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2899@findex -tpmdev
2900
2901The specific backend type will determine the applicable options.
2902The @code{-tpmdev} option creates the TPM backend and requires a
2903@code{-device} option that specifies the TPM frontend interface model.
2904
2905Use @code{-tpmdev help} to print all available TPM backend types.
2906
2907@end table
2908
2909The available backends are:
2910
2911@table @option
2912
2913@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2914
2915(Linux-host only) Enable access to the host's TPM using the passthrough
2916driver.
2917
2918@option{path} specifies the path to the host's TPM device, i.e., on
2919a Linux host this would be @code{/dev/tpm0}.
2920@option{path} is optional and by default @code{/dev/tpm0} is used.
2921
2922@option{cancel-path} specifies the path to the host TPM device's sysfs
2923entry allowing for cancellation of an ongoing TPM command.
2924@option{cancel-path} is optional and by default QEMU will search for the
2925sysfs entry to use.
2926
2927Some notes about using the host's TPM with the passthrough driver:
2928
2929The TPM device accessed by the passthrough driver must not be
2930used by any other application on the host.
2931
2932Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2933the VM's firmware (BIOS/UEFI) will not be able to initialize the
2934TPM again and may therefore not show a TPM-specific menu that would
2935otherwise allow the user to configure the TPM, e.g., allow the user to
2936enable/disable or activate/deactivate the TPM.
2937Further, if TPM ownership is released from within a VM then the host's TPM
2938will get disabled and deactivated. To enable and activate the
2939TPM again afterwards, the host has to be rebooted and the user is
2940required to enter the firmware's menu to enable and activate the TPM.
2941If the TPM is left disabled and/or deactivated most TPM commands will fail.
2942
2943To create a passthrough TPM use the following two options:
2944@example
2945-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2946@end example
2947Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2948@code{tpmdev=tpm0} in the device option.
2949
2950@item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2951
2952(Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2953chardev backend.
2954
2955@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2956
2957To create a TPM emulator backend device with chardev socket backend:
2958@example
2959
2960-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2961
2962@end example
2963
2964ETEXI
2965
2966STEXI
2967@end table
2968ETEXI
2969DEFHEADING()
2970
2971#endif
2972
2973DEFHEADING(Linux/Multiboot boot specific:)
2974STEXI
2975
2976When using these options, you can use a given Linux or Multiboot
2977kernel without installing it in the disk image. It can be useful
2978for easier testing of various kernels.
2979
2980@table @option
2981ETEXI
2982
2983DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
2984 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
2985STEXI
2986@item -kernel @var{bzImage}
2987@findex -kernel
2988Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2989or in multiboot format.
2990ETEXI
2991
2992DEF("append", HAS_ARG, QEMU_OPTION_append, \
2993 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
2994STEXI
2995@item -append @var{cmdline}
2996@findex -append
2997Use @var{cmdline} as kernel command line
2998ETEXI
2999
3000DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
3001 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
3002STEXI
3003@item -initrd @var{file}
3004@findex -initrd
3005Use @var{file} as initial ram disk.
3006
3007@item -initrd "@var{file1} arg=foo,@var{file2}"
3008
3009This syntax is only available with multiboot.
3010
3011Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3012first module.
3013ETEXI
3014
3015DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
3016 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
3017STEXI
3018@item -dtb @var{file}
3019@findex -dtb
3020Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3021on boot.
3022ETEXI
3023
3024STEXI
3025@end table
3026ETEXI
3027DEFHEADING()
3028
3029DEFHEADING(Debug/Expert options:)
3030STEXI
3031@table @option
3032ETEXI
3033
3034DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3035 "-fw_cfg [name=]<name>,file=<file>\n"
3036 " add named fw_cfg entry with contents from file\n"
3037 "-fw_cfg [name=]<name>,string=<str>\n"
3038 " add named fw_cfg entry with contents from string\n",
3039 QEMU_ARCH_ALL)
3040STEXI
3041
3042@item -fw_cfg [name=]@var{name},file=@var{file}
3043@findex -fw_cfg
3044Add named fw_cfg entry with contents from file @var{file}.
3045
3046@item -fw_cfg [name=]@var{name},string=@var{str}
3047Add named fw_cfg entry with contents from string @var{str}.
3048
3049The terminating NUL character of the contents of @var{str} will not be
3050included as part of the fw_cfg item data. To insert contents with
3051embedded NUL characters, you have to use the @var{file} parameter.
3052
3053The fw_cfg entries are passed by QEMU through to the guest.
3054
3055Example:
3056@example
3057 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3058@end example
3059creates an fw_cfg entry named opt/com.mycompany/blob with contents
3060from ./my_blob.bin.
3061
3062ETEXI
3063
3064DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3065 "-serial dev redirect the serial port to char device 'dev'\n",
3066 QEMU_ARCH_ALL)
3067STEXI
3068@item -serial @var{dev}
3069@findex -serial
3070Redirect the virtual serial port to host character device
3071@var{dev}. The default device is @code{vc} in graphical mode and
3072@code{stdio} in non graphical mode.
3073
3074This option can be used several times to simulate up to 4 serial
3075ports.
3076
3077Use @code{-serial none} to disable all serial ports.
3078
3079Available character devices are:
3080@table @option
3081@item vc[:@var{W}x@var{H}]
3082Virtual console. Optionally, a width and height can be given in pixel with
3083@example
3084vc:800x600
3085@end example
3086It is also possible to specify width or height in characters:
3087@example
3088vc:80Cx24C
3089@end example
3090@item pty
3091[Linux only] Pseudo TTY (a new PTY is automatically allocated)
3092@item none
3093No device is allocated.
3094@item null
3095void device
3096@item chardev:@var{id}
3097Use a named character device defined with the @code{-chardev} option.
3098@item /dev/XXX
3099[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3100parameters are set according to the emulated ones.
3101@item /dev/parport@var{N}
3102[Linux only, parallel port only] Use host parallel port
3103@var{N}. Currently SPP and EPP parallel port features can be used.
3104@item file:@var{filename}
3105Write output to @var{filename}. No character can be read.
3106@item stdio
3107[Unix only] standard input/output
3108@item pipe:@var{filename}
3109name pipe @var{filename}
3110@item COM@var{n}
3111[Windows only] Use host serial port @var{n}
3112@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3113This implements UDP Net Console.
3114When @var{remote_host} or @var{src_ip} are not specified
3115they default to @code{0.0.0.0}.
3116When not using a specified @var{src_port} a random port is automatically chosen.
3117
3118If you just want a simple readonly console you can use @code{netcat} or
3119@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3120@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3121will appear in the netconsole session.
3122
3123If you plan to send characters back via netconsole or you want to stop
3124and start QEMU a lot of times, you should have QEMU use the same
3125source port each time by using something like @code{-serial
3126udp::4555@@:4556} to QEMU. Another approach is to use a patched
3127version of netcat which can listen to a TCP port and send and receive
3128characters via udp. If you have a patched version of netcat which
3129activates telnet remote echo and single char transfer, then you can
3130use the following options to set up a netcat redirector to allow
3131telnet on port 5555 to access the QEMU port.
3132@table @code
3133@item QEMU Options:
3134-serial udp::4555@@:4556
3135@item netcat options:
3136-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3137@item telnet options:
3138localhost 5555
3139@end table
3140
3141@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3142The TCP Net Console has two modes of operation. It can send the serial
3143I/O to a location or wait for a connection from a location. By default
3144the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3145the @var{server} option QEMU will wait for a client socket application
3146to connect to the port before continuing, unless the @code{nowait}
3147option was specified. The @code{nodelay} option disables the Nagle buffering
3148algorithm. The @code{reconnect} option only applies if @var{noserver} is
3149set, if the connection goes down it will attempt to reconnect at the
3150given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3151one TCP connection at a time is accepted. You can use @code{telnet} to
3152connect to the corresponding character device.
3153@table @code
3154@item Example to send tcp console to 192.168.0.2 port 4444
3155-serial tcp:192.168.0.2:4444
3156@item Example to listen and wait on port 4444 for connection
3157-serial tcp::4444,server
3158@item Example to not wait and listen on ip 192.168.0.100 port 4444
3159-serial tcp:192.168.0.100:4444,server,nowait
3160@end table
3161
3162@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3163The telnet protocol is used instead of raw tcp sockets. The options
3164work the same as if you had specified @code{-serial tcp}. The
3165difference is that the port acts like a telnet server or client using
3166telnet option negotiation. This will also allow you to send the
3167MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3168sequence. Typically in unix telnet you do it with Control-] and then
3169type "send break" followed by pressing the enter key.
3170
3171@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3172A unix domain socket is used instead of a tcp socket. The option works the
3173same as if you had specified @code{-serial tcp} except the unix domain socket
3174@var{path} is used for connections.
3175
3176@item mon:@var{dev_string}
3177This is a special option to allow the monitor to be multiplexed onto
3178another serial port. The monitor is accessed with key sequence of
3179@key{Control-a} and then pressing @key{c}.
3180@var{dev_string} should be any one of the serial devices specified
3181above. An example to multiplex the monitor onto a telnet server
3182listening on port 4444 would be:
3183@table @code
3184@item -serial mon:telnet::4444,server,nowait
3185@end table
3186When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3187QEMU any more but will be passed to the guest instead.
3188
3189@item braille
3190Braille device. This will use BrlAPI to display the braille output on a real
3191or fake device.
3192
3193@item msmouse
3194Three button serial mouse. Configure the guest to use Microsoft protocol.
3195@end table
3196ETEXI
3197
3198DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3199 "-parallel dev redirect the parallel port to char device 'dev'\n",
3200 QEMU_ARCH_ALL)
3201STEXI
3202@item -parallel @var{dev}
3203@findex -parallel
3204Redirect the virtual parallel port to host device @var{dev} (same
3205devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3206be used to use hardware devices connected on the corresponding host
3207parallel port.
3208
3209This option can be used several times to simulate up to 3 parallel
3210ports.
3211
3212Use @code{-parallel none} to disable all parallel ports.
3213ETEXI
3214
3215DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3216 "-monitor dev redirect the monitor to char device 'dev'\n",
3217 QEMU_ARCH_ALL)
3218STEXI
3219@item -monitor @var{dev}
3220@findex -monitor
3221Redirect the monitor to host device @var{dev} (same devices as the
3222serial port).
3223The default device is @code{vc} in graphical mode and @code{stdio} in
3224non graphical mode.
3225Use @code{-monitor none} to disable the default monitor.
3226ETEXI
3227DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3228 "-qmp dev like -monitor but opens in 'control' mode\n",
3229 QEMU_ARCH_ALL)
3230STEXI
3231@item -qmp @var{dev}
3232@findex -qmp
3233Like -monitor but opens in 'control' mode.
3234ETEXI
3235DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3236 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3237 QEMU_ARCH_ALL)
3238STEXI
3239@item -qmp-pretty @var{dev}
3240@findex -qmp-pretty
3241Like -qmp but uses pretty JSON formatting.
3242ETEXI
3243
3244DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3245 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3246STEXI
3247@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3248@findex -mon
3249Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3250easing human reading and debugging.
3251ETEXI
3252
3253DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3254 "-debugcon dev redirect the debug console to char device 'dev'\n",
3255 QEMU_ARCH_ALL)
3256STEXI
3257@item -debugcon @var{dev}
3258@findex -debugcon
3259Redirect the debug console to host device @var{dev} (same devices as the
3260serial port). The debug console is an I/O port which is typically port
32610xe9; writing to that I/O port sends output to this device.
3262The default device is @code{vc} in graphical mode and @code{stdio} in
3263non graphical mode.
3264ETEXI
3265
3266DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3267 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
3268STEXI
3269@item -pidfile @var{file}
3270@findex -pidfile
3271Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3272from a script.
3273ETEXI
3274
3275DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3276 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
3277STEXI
3278@item -singlestep
3279@findex -singlestep
3280Run the emulation in single step mode.
3281ETEXI
3282
3283DEF("preconfig", 0, QEMU_OPTION_preconfig, \
3284 "--preconfig pause QEMU before machine is initialized (experimental)\n",
3285 QEMU_ARCH_ALL)
3286STEXI
3287@item --preconfig
3288@findex --preconfig
3289Pause QEMU for interactive configuration before the machine is created,
3290which allows querying and configuring properties that will affect
3291machine initialization. Use QMP command 'x-exit-preconfig' to exit
3292the preconfig state and move to the next state (i.e. run guest if -S
3293isn't used or pause the second time if -S is used). This option is
3294experimental.
3295ETEXI
3296
3297DEF("S", 0, QEMU_OPTION_S, \
3298 "-S freeze CPU at startup (use 'c' to start execution)\n",
3299 QEMU_ARCH_ALL)
3300STEXI
3301@item -S
3302@findex -S
3303Do not start CPU at startup (you must type 'c' in the monitor).
3304ETEXI
3305
3306DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3307 "-realtime [mlock=on|off]\n"
3308 " run qemu with realtime features\n"
3309 " mlock=on|off controls mlock support (default: on)\n",
3310 QEMU_ARCH_ALL)
3311STEXI
3312@item -realtime mlock=on|off
3313@findex -realtime
3314Run qemu with realtime features.
3315mlocking qemu and guest memory can be enabled via @option{mlock=on}
3316(enabled by default).
3317ETEXI
3318
3319DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit,
3320 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n"
3321 " run qemu with overcommit hints\n"
3322 " mem-lock=on|off controls memory lock support (default: off)\n"
3323 " cpu-pm=on|off controls cpu power management (default: off)\n",
3324 QEMU_ARCH_ALL)
3325STEXI
3326@item -overcommit mem-lock=on|off
3327@item -overcommit cpu-pm=on|off
3328@findex -overcommit
3329Run qemu with hints about host resource overcommit. The default is
3330to assume that host overcommits all resources.
3331
3332Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled
3333by default). This works when host memory is not overcommitted and reduces the
3334worst-case latency for guest. This is equivalent to @option{realtime}.
3335
3336Guest ability to manage power state of host cpus (increasing latency for other
3337processes on the same host cpu, but decreasing latency for guest) can be
3338enabled via @option{cpu-pm=on} (disabled by default). This works best when
3339host CPU is not overcommitted. When used, host estimates of CPU cycle and power
3340utilization will be incorrect, not taking into account guest idle time.
3341ETEXI
3342
3343DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3344 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3345STEXI
3346@item -gdb @var{dev}
3347@findex -gdb
3348Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3349connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3350stdio are reasonable use case. The latter is allowing to start QEMU from
3351within gdb and establish the connection via a pipe:
3352@example
3353(gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3354@end example
3355ETEXI
3356
3357DEF("s", 0, QEMU_OPTION_s, \
3358 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3359 QEMU_ARCH_ALL)
3360STEXI
3361@item -s
3362@findex -s
3363Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3364(@pxref{gdb_usage}).
3365ETEXI
3366
3367DEF("d", HAS_ARG, QEMU_OPTION_d, \
3368 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
3369 QEMU_ARCH_ALL)
3370STEXI
3371@item -d @var{item1}[,...]
3372@findex -d
3373Enable logging of specified items. Use '-d help' for a list of log items.
3374ETEXI
3375
3376DEF("D", HAS_ARG, QEMU_OPTION_D, \
3377 "-D logfile output log to logfile (default stderr)\n",
3378 QEMU_ARCH_ALL)
3379STEXI
3380@item -D @var{logfile}
3381@findex -D
3382Output log in @var{logfile} instead of to stderr
3383ETEXI
3384
3385DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3386 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3387 QEMU_ARCH_ALL)
3388STEXI
3389@item -dfilter @var{range1}[,...]
3390@findex -dfilter
3391Filter debug output to that relevant to a range of target addresses. The filter
3392spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3393@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3394addresses and sizes required. For example:
3395@example
3396 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3397@end example
3398Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3399the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3400block starting at 0xffffffc00005f000.
3401ETEXI
3402
3403DEF("L", HAS_ARG, QEMU_OPTION_L, \
3404 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
3405 QEMU_ARCH_ALL)
3406STEXI
3407@item -L @var{path}
3408@findex -L
3409Set the directory for the BIOS, VGA BIOS and keymaps.
3410
3411To list all the data directories, use @code{-L help}.
3412ETEXI
3413
3414DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3415 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
3416STEXI
3417@item -bios @var{file}
3418@findex -bios
3419Set the filename for the BIOS.
3420ETEXI
3421
3422DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3423 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3424STEXI
3425@item -enable-kvm
3426@findex -enable-kvm
3427Enable KVM full virtualization support. This option is only available
3428if KVM support is enabled when compiling.
3429ETEXI
3430
3431DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3432 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386)
3433STEXI
3434@item -enable-hax
3435@findex -enable-hax
3436Enable HAX (Hardware-based Acceleration eXecution) support. This option
3437is only available if HAX support is enabled when compiling. HAX is only
3438applicable to MAC and Windows platform, and thus does not conflict with
3439KVM. This option is deprecated, use @option{-accel hax} instead.
3440ETEXI
3441
3442DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3443 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
3444DEF("xen-create", 0, QEMU_OPTION_xen_create,
3445 "-xen-create create domain using xen hypercalls, bypassing xend\n"
3446 " warning: should not be used when xend is in use\n",
3447 QEMU_ARCH_ALL)
3448DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3449 "-xen-attach attach to existing xen domain\n"
3450 " xend will use this when starting QEMU\n",
3451 QEMU_ARCH_ALL)
3452DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3453 "-xen-domid-restrict restrict set of available xen operations\n"
3454 " to specified domain id. (Does not affect\n"
3455 " xenpv machine type).\n",
3456 QEMU_ARCH_ALL)
3457STEXI
3458@item -xen-domid @var{id}
3459@findex -xen-domid
3460Specify xen guest domain @var{id} (XEN only).
3461@item -xen-create
3462@findex -xen-create
3463Create domain using xen hypercalls, bypassing xend.
3464Warning: should not be used when xend is in use (XEN only).
3465@item -xen-attach
3466@findex -xen-attach
3467Attach to existing xen domain.
3468xend will use this when starting QEMU (XEN only).
3469@findex -xen-domid-restrict
3470Restrict set of available xen operations to specified domain id (XEN only).
3471ETEXI
3472
3473DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3474 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
3475STEXI
3476@item -no-reboot
3477@findex -no-reboot
3478Exit instead of rebooting.
3479ETEXI
3480
3481DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3482 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
3483STEXI
3484@item -no-shutdown
3485@findex -no-shutdown
3486Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3487This allows for instance switching to monitor to commit changes to the
3488disk image.
3489ETEXI
3490
3491DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3492 "-loadvm [tag|id]\n" \
3493 " start right away with a saved state (loadvm in monitor)\n",
3494 QEMU_ARCH_ALL)
3495STEXI
3496@item -loadvm @var{file}
3497@findex -loadvm
3498Start right away with a saved state (@code{loadvm} in monitor)
3499ETEXI
3500
3501#ifndef _WIN32
3502DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3503 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3504#endif
3505STEXI
3506@item -daemonize
3507@findex -daemonize
3508Daemonize the QEMU process after initialization. QEMU will not detach from
3509standard IO until it is ready to receive connections on any of its devices.
3510This option is a useful way for external programs to launch QEMU without having
3511to cope with initialization race conditions.
3512ETEXI
3513
3514DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3515 "-option-rom rom load a file, rom, into the option ROM space\n",
3516 QEMU_ARCH_ALL)
3517STEXI
3518@item -option-rom @var{file}
3519@findex -option-rom
3520Load the contents of @var{file} as an option ROM.
3521This option is useful to load things like EtherBoot.
3522ETEXI
3523
3524HXCOMM Silently ignored for compatibility
3525DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3526
3527HXCOMM Options deprecated by -rtc
3528DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3529DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3530
3531DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3532 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3533 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3534 QEMU_ARCH_ALL)
3535
3536STEXI
3537
3538@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3539@findex -rtc
3540Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3541UTC or local time, respectively. @code{localtime} is required for correct date in
3542MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3543format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3544
3545By default the RTC is driven by the host system time. This allows using of the
3546RTC as accurate reference clock inside the guest, specifically if the host
3547time is smoothly following an accurate external reference clock, e.g. via NTP.
3548If you want to isolate the guest time from the host, you can set @option{clock}
3549to @code{rt} instead. To even prevent it from progressing during suspension,
3550you can set it to @code{vm}.
3551
3552Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3553specifically with Windows' ACPI HAL. This option will try to figure out how
3554many timer interrupts were not processed by the Windows guest and will
3555re-inject them.
3556ETEXI
3557
3558DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3559 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3560 " enable virtual instruction counter with 2^N clock ticks per\n" \
3561 " instruction, enable aligning the host and virtual clocks\n" \
3562 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3563STEXI
3564@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3565@findex -icount
3566Enable virtual instruction counter. The virtual cpu will execute one
3567instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3568then the virtual cpu speed will be automatically adjusted to keep virtual
3569time within a few seconds of real time.
3570
3571When the virtual cpu is sleeping, the virtual time will advance at default
3572speed unless @option{sleep=on|off} is specified.
3573With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3574instantly whenever the virtual cpu goes to sleep mode and will not advance
3575if no timer is enabled. This behavior give deterministic execution times from
3576the guest point of view.
3577
3578Note that while this option can give deterministic behavior, it does not
3579provide cycle accurate emulation. Modern CPUs contain superscalar out of
3580order cores with complex cache hierarchies. The number of instructions
3581executed often has little or no correlation with actual performance.
3582
3583@option{align=on} will activate the delay algorithm which will try
3584to synchronise the host clock and the virtual clock. The goal is to
3585have a guest running at the real frequency imposed by the shift option.
3586Whenever the guest clock is behind the host clock and if
3587@option{align=on} is specified then we print a message to the user
3588to inform about the delay.
3589Currently this option does not work when @option{shift} is @code{auto}.
3590Note: The sync algorithm will work for those shift values for which
3591the guest clock runs ahead of the host clock. Typically this happens
3592when the shift value is high (how high depends on the host machine).
3593
3594When @option{rr} option is specified deterministic record/replay is enabled.
3595Replay log is written into @var{filename} file in record mode and
3596read from this file in replay mode.
3597
3598Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3599at the start of execution recording. In replay mode this option is used
3600to load the initial VM state.
3601ETEXI
3602
3603DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3604 "-watchdog model\n" \
3605 " enable virtual hardware watchdog [default=none]\n",
3606 QEMU_ARCH_ALL)
3607STEXI
3608@item -watchdog @var{model}
3609@findex -watchdog
3610Create a virtual hardware watchdog device. Once enabled (by a guest
3611action), the watchdog must be periodically polled by an agent inside
3612the guest or else the guest will be restarted. Choose a model for
3613which your guest has drivers.
3614
3615The @var{model} is the model of hardware watchdog to emulate. Use
3616@code{-watchdog help} to list available hardware models. Only one
3617watchdog can be enabled for a guest.
3618
3619The following models may be available:
3620@table @option
3621@item ib700
3622iBASE 700 is a very simple ISA watchdog with a single timer.
3623@item i6300esb
3624Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3625dual-timer watchdog.
3626@item diag288
3627A virtual watchdog for s390x backed by the diagnose 288 hypercall
3628(currently KVM only).
3629@end table
3630ETEXI
3631
3632DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3633 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3634 " action when watchdog fires [default=reset]\n",
3635 QEMU_ARCH_ALL)
3636STEXI
3637@item -watchdog-action @var{action}
3638@findex -watchdog-action
3639
3640The @var{action} controls what QEMU will do when the watchdog timer
3641expires.
3642The default is
3643@code{reset} (forcefully reset the guest).
3644Other possible actions are:
3645@code{shutdown} (attempt to gracefully shutdown the guest),
3646@code{poweroff} (forcefully poweroff the guest),
3647@code{inject-nmi} (inject a NMI into the guest),
3648@code{pause} (pause the guest),
3649@code{debug} (print a debug message and continue), or
3650@code{none} (do nothing).
3651
3652Note that the @code{shutdown} action requires that the guest responds
3653to ACPI signals, which it may not be able to do in the sort of
3654situations where the watchdog would have expired, and thus
3655@code{-watchdog-action shutdown} is not recommended for production use.
3656
3657Examples:
3658
3659@table @code
3660@item -watchdog i6300esb -watchdog-action pause
3661@itemx -watchdog ib700
3662@end table
3663ETEXI
3664
3665DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3666 "-echr chr set terminal escape character instead of ctrl-a\n",
3667 QEMU_ARCH_ALL)
3668STEXI
3669
3670@item -echr @var{numeric_ascii_value}
3671@findex -echr
3672Change the escape character used for switching to the monitor when using
3673monitor and serial sharing. The default is @code{0x01} when using the
3674@code{-nographic} option. @code{0x01} is equal to pressing
3675@code{Control-a}. You can select a different character from the ascii
3676control keys where 1 through 26 map to Control-a through Control-z. For
3677instance you could use the either of the following to change the escape
3678character to Control-t.
3679@table @code
3680@item -echr 0x14
3681@itemx -echr 20
3682@end table
3683ETEXI
3684
3685DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3686 "-virtioconsole c\n" \
3687 " set virtio console\n", QEMU_ARCH_ALL)
3688STEXI
3689@item -virtioconsole @var{c}
3690@findex -virtioconsole
3691Set virtio console.
3692This option is deprecated, please use @option{-device virtconsole} instead.
3693ETEXI
3694
3695DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3696 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
3697STEXI
3698@item -show-cursor
3699@findex -show-cursor
3700Show cursor.
3701ETEXI
3702
3703DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3704 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
3705STEXI
3706@item -tb-size @var{n}
3707@findex -tb-size
3708Set TB size.
3709ETEXI
3710
3711DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3712 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3713 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3714 "-incoming unix:socketpath\n" \
3715 " prepare for incoming migration, listen on\n" \
3716 " specified protocol and socket address\n" \
3717 "-incoming fd:fd\n" \
3718 "-incoming exec:cmdline\n" \
3719 " accept incoming migration on given file descriptor\n" \
3720 " or from given external command\n" \
3721 "-incoming defer\n" \
3722 " wait for the URI to be specified via migrate_incoming\n",
3723 QEMU_ARCH_ALL)
3724STEXI
3725@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3726@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3727@findex -incoming
3728Prepare for incoming migration, listen on a given tcp port.
3729
3730@item -incoming unix:@var{socketpath}
3731Prepare for incoming migration, listen on a given unix socket.
3732
3733@item -incoming fd:@var{fd}
3734Accept incoming migration from a given filedescriptor.
3735
3736@item -incoming exec:@var{cmdline}
3737Accept incoming migration as an output from specified external command.
3738
3739@item -incoming defer
3740Wait for the URI to be specified via migrate_incoming. The monitor can
3741be used to change settings (such as migration parameters) prior to issuing
3742the migrate_incoming to allow the migration to begin.
3743ETEXI
3744
3745DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3746 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
3747STEXI
3748@item -only-migratable
3749@findex -only-migratable
3750Only allow migratable devices. Devices will not be allowed to enter an
3751unmigratable state.
3752ETEXI
3753
3754DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3755 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
3756STEXI
3757@item -nodefaults
3758@findex -nodefaults
3759Don't create default devices. Normally, QEMU sets the default devices like serial
3760port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3761CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3762default devices.
3763ETEXI
3764
3765#ifndef _WIN32
3766DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3767 "-chroot dir chroot to dir just before starting the VM\n",
3768 QEMU_ARCH_ALL)
3769#endif
3770STEXI
3771@item -chroot @var{dir}
3772@findex -chroot
3773Immediately before starting guest execution, chroot to the specified
3774directory. Especially useful in combination with -runas.
3775ETEXI
3776
3777#ifndef _WIN32
3778DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3779 "-runas user change to user id user just before starting the VM\n" \
3780 " user can be numeric uid:gid instead\n",
3781 QEMU_ARCH_ALL)
3782#endif
3783STEXI
3784@item -runas @var{user}
3785@findex -runas
3786Immediately before starting guest execution, drop root privileges, switching
3787to the specified user.
3788ETEXI
3789
3790DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3791 "-prom-env variable=value\n"
3792 " set OpenBIOS nvram variables\n",
3793 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3794STEXI
3795@item -prom-env @var{variable}=@var{value}
3796@findex -prom-env
3797Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3798ETEXI
3799DEF("semihosting", 0, QEMU_OPTION_semihosting,
3800 "-semihosting semihosting mode\n",
3801 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3802 QEMU_ARCH_MIPS)
3803STEXI
3804@item -semihosting
3805@findex -semihosting
3806Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3807ETEXI
3808DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3809 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3810 " semihosting configuration\n",
3811QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3812QEMU_ARCH_MIPS)
3813STEXI
3814@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3815@findex -semihosting-config
3816Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3817@table @option
3818@item target=@code{native|gdb|auto}
3819Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3820or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3821during debug sessions and @code{native} otherwise.
3822@item arg=@var{str1},arg=@var{str2},...
3823Allows the user to pass input arguments, and can be used multiple times to build
3824up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3825command line is still supported for backward compatibility. If both the
3826@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3827specified, the former is passed to semihosting as it always takes precedence.
3828@end table
3829ETEXI
3830DEF("old-param", 0, QEMU_OPTION_old_param,
3831 "-old-param old param mode\n", QEMU_ARCH_ARM)
3832STEXI
3833@item -old-param
3834@findex -old-param (ARM)
3835Old param mode (ARM only).
3836ETEXI
3837
3838DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3839 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3840 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3841 " Enable seccomp mode 2 system call filter (default 'off').\n" \
3842 " use 'obsolete' to allow obsolete system calls that are provided\n" \
3843 " by the kernel, but typically no longer used by modern\n" \
3844 " C library implementations.\n" \
3845 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3846 " its privileges by blacklisting all set*uid|gid system calls.\n" \
3847 " The value 'children' will deny set*uid|gid system calls for\n" \
3848 " main QEMU process but will allow forks and execves to run unprivileged\n" \
3849 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3850 " blacklisting *fork and execve\n" \
3851 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
3852 QEMU_ARCH_ALL)
3853STEXI
3854@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3855@findex -sandbox
3856Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3857disable it. The default is 'off'.
3858@table @option
3859@item obsolete=@var{string}
3860Enable Obsolete system calls
3861@item elevateprivileges=@var{string}
3862Disable set*uid|gid system calls
3863@item spawn=@var{string}
3864Disable *fork and execve
3865@item resourcecontrol=@var{string}
3866Disable process affinity and schedular priority
3867@end table
3868ETEXI
3869
3870DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3871 "-readconfig <file>\n", QEMU_ARCH_ALL)
3872STEXI
3873@item -readconfig @var{file}
3874@findex -readconfig
3875Read device configuration from @var{file}. This approach is useful when you want to spawn
3876QEMU process with many command line options but you don't want to exceed the command line
3877character limit.
3878ETEXI
3879DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3880 "-writeconfig <file>\n"
3881 " read/write config file\n", QEMU_ARCH_ALL)
3882STEXI
3883@item -writeconfig @var{file}
3884@findex -writeconfig
3885Write device configuration to @var{file}. The @var{file} can be either filename to save
3886command line and device configuration into file or dash @code{-}) character to print the
3887output to stdout. This can be later used as input file for @code{-readconfig} option.
3888ETEXI
3889HXCOMM Deprecated, same as -no-user-config
3890DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
3891DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3892 "-no-user-config\n"
3893 " do not load default user-provided config files at startup\n",
3894 QEMU_ARCH_ALL)
3895STEXI
3896@item -no-user-config
3897@findex -no-user-config
3898The @code{-no-user-config} option makes QEMU not load any of the user-provided
3899config files on @var{sysconfdir}.
3900ETEXI
3901DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3902 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3903 " specify tracing options\n",
3904 QEMU_ARCH_ALL)
3905STEXI
3906HXCOMM This line is not accurate, as some sub-options are backend-specific but
3907HXCOMM HX does not support conditional compilation of text.
3908@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3909@findex -trace
3910@include qemu-option-trace.texi
3911ETEXI
3912
3913HXCOMM Internal use
3914DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3915DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3916
3917#ifdef __linux__
3918DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3919 "-enable-fips enable FIPS 140-2 compliance\n",
3920 QEMU_ARCH_ALL)
3921#endif
3922STEXI
3923@item -enable-fips
3924@findex -enable-fips
3925Enable FIPS 140-2 compliance mode.
3926ETEXI
3927
3928HXCOMM Deprecated by -machine accel=tcg property
3929DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3930
3931DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3932 "-msg timestamp[=on|off]\n"
3933 " change the format of messages\n"
3934 " on|off controls leading timestamps (default:on)\n",
3935 QEMU_ARCH_ALL)
3936STEXI
3937@item -msg timestamp[=on|off]
3938@findex -msg
3939prepend a timestamp to each log message.(default:on)
3940ETEXI
3941
3942DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3943 "-dump-vmstate <file>\n"
3944 " Output vmstate information in JSON format to file.\n"
3945 " Use the scripts/vmstate-static-checker.py file to\n"
3946 " check for possible regressions in migration code\n"
3947 " by comparing two such vmstate dumps.\n",
3948 QEMU_ARCH_ALL)
3949STEXI
3950@item -dump-vmstate @var{file}
3951@findex -dump-vmstate
3952Dump json-encoded vmstate information for current machine type to file
3953in @var{file}
3954ETEXI
3955
3956DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
3957 "-enable-sync-profile\n"
3958 " enable synchronization profiling\n",
3959 QEMU_ARCH_ALL)
3960STEXI
3961@item -enable-sync-profile
3962@findex -enable-sync-profile
3963Enable synchronization profiling.
3964ETEXI
3965
3966STEXI
3967@end table
3968ETEXI
3969DEFHEADING()
3970
3971DEFHEADING(Generic object creation:)
3972STEXI
3973@table @option
3974ETEXI
3975
3976DEF("object", HAS_ARG, QEMU_OPTION_object,
3977 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3978 " create a new object of type TYPENAME setting properties\n"
3979 " in the order they are specified. Note that the 'id'\n"
3980 " property must be set. These objects are placed in the\n"
3981 " '/objects' path.\n",
3982 QEMU_ARCH_ALL)
3983STEXI
3984@item -object @var{typename}[,@var{prop1}=@var{value1},...]
3985@findex -object
3986Create a new object of type @var{typename} setting properties
3987in the order they are specified. Note that the 'id'
3988property must be set. These objects are placed in the
3989'/objects' path.
3990
3991@table @option
3992
3993@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}
3994
3995Creates a memory file backend object, which can be used to back
3996the guest RAM with huge pages.
3997
3998The @option{id} parameter is a unique ID that will be used to reference this
3999memory region when configuring the @option{-numa} argument.
4000
4001The @option{size} option provides the size of the memory region, and accepts
4002common suffixes, eg @option{500M}.
4003
4004The @option{mem-path} provides the path to either a shared memory or huge page
4005filesystem mount.
4006
4007The @option{share} boolean option determines whether the memory
4008region is marked as private to QEMU, or shared. The latter allows
4009a co-operating external process to access the QEMU memory region.
4010
4011The @option{share} is also required for pvrdma devices due to
4012limitations in the RDMA API provided by Linux.
4013
4014Setting share=on might affect the ability to configure NUMA
4015bindings for the memory backend under some circumstances, see
4016Documentation/vm/numa_memory_policy.txt on the Linux kernel
4017source tree for additional details.
4018
4019Setting the @option{discard-data} boolean option to @var{on}
4020indicates that file contents can be destroyed when QEMU exits,
4021to avoid unnecessarily flushing data to the backing file. Note
4022that @option{discard-data} is only an optimization, and QEMU
4023might not discard file contents if it aborts unexpectedly or is
4024terminated using SIGKILL.
4025
4026The @option{merge} boolean option enables memory merge, also known as
4027MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
4028memory deduplication.
4029
4030Setting the @option{dump} boolean option to @var{off} excludes the memory from
4031core dumps. This feature is also known as MADV_DONTDUMP.
4032
4033The @option{prealloc} boolean option enables memory preallocation.
4034
4035The @option{host-nodes} option binds the memory range to a list of NUMA host
4036nodes.
4037
4038The @option{policy} option sets the NUMA policy to one of the following values:
4039
4040@table @option
4041@item @var{default}
4042default host policy
4043
4044@item @var{preferred}
4045prefer the given host node list for allocation
4046
4047@item @var{bind}
4048restrict memory allocation to the given host node list
4049
4050@item @var{interleave}
4051interleave memory allocations across the given host node list
4052@end table
4053
4054The @option{align} option specifies the base address alignment when
4055QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
4056@option{2M}. Some backend store specified by @option{mem-path}
4057requires an alignment different than the default one used by QEMU, eg
4058the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4059such cases, users can specify the required alignment via this option.
4060
4061The @option{pmem} option specifies whether the backing file specified
4062by @option{mem-path} is in host persistent memory that can be accessed
4063using the SNIA NVM programming model (e.g. Intel NVDIMM).
4064If @option{pmem} is set to 'on', QEMU will take necessary operations to
4065guarantee the persistence of its own writes to @option{mem-path}
4066(e.g. in vNVDIMM label emulation and live migration).
4067
4068@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}
4069
4070Creates a memory backend object, which can be used to back the guest RAM.
4071Memory backend objects offer more control than the @option{-m} option that is
4072traditionally used to define guest RAM. Please refer to
4073@option{memory-backend-file} for a description of the options.
4074
4075@item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@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}
4076
4077Creates an anonymous memory file backend object, which allows QEMU to
4078share the memory with an external process (e.g. when using
4079vhost-user). The memory is allocated with memfd and optional
4080sealing. (Linux only)
4081
4082The @option{seal} option creates a sealed-file, that will block
4083further resizing the memory ('on' by default).
4084
4085The @option{hugetlb} option specify the file to be created resides in
4086the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with
4087the @option{hugetlb} option, the @option{hugetlbsize} option specify
4088the hugetlb page size on systems that support multiple hugetlb page
4089sizes (it must be a power of 2 value supported by the system).
4090
4091In some versions of Linux, the @option{hugetlb} option is incompatible
4092with the @option{seal} option (requires at least Linux 4.16).
4093
4094Please refer to @option{memory-backend-file} for a description of the
4095other options.
4096
4097@item -object rng-random,id=@var{id},filename=@var{/dev/random}
4098
4099Creates a random number generator backend which obtains entropy from
4100a device on the host. The @option{id} parameter is a unique ID that
4101will be used to reference this entropy backend from the @option{virtio-rng}
4102device. The @option{filename} parameter specifies which file to obtain
4103entropy from and if omitted defaults to @option{/dev/random}.
4104
4105@item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4106
4107Creates a random number generator backend which obtains entropy from
4108an external daemon running on the host. The @option{id} parameter is
4109a unique ID that will be used to reference this entropy backend from
4110the @option{virtio-rng} device. The @option{chardev} parameter is
4111the unique ID of a character device backend that provides the connection
4112to the RNG daemon.
4113
4114@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4115
4116Creates a TLS anonymous credentials object, which can be used to provide
4117TLS support on network backends. The @option{id} parameter is a unique
4118ID which network backends will use to access the credentials. The
4119@option{endpoint} is either @option{server} or @option{client} depending
4120on whether the QEMU network backend that uses the credentials will be
4121acting as a client or as a server. If @option{verify-peer} is enabled
4122(the default) then once the handshake is completed, the peer credentials
4123will be verified, though this is a no-op for anonymous credentials.
4124
4125The @var{dir} parameter tells QEMU where to find the credential
4126files. For server endpoints, this directory may contain a file
4127@var{dh-params.pem} providing diffie-hellman parameters to use
4128for the TLS server. If the file is missing, QEMU will generate
4129a set of DH parameters at startup. This is a computationally
4130expensive operation that consumes random pool entropy, so it is
4131recommended that a persistent set of parameters be generated
4132upfront and saved.
4133
4134@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}]
4135
4136Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide
4137TLS support on network backends. The @option{id} parameter is a unique
4138ID which network backends will use to access the credentials. The
4139@option{endpoint} is either @option{server} or @option{client} depending
4140on whether the QEMU network backend that uses the credentials will be
4141acting as a client or as a server. For clients only, @option{username}
4142is the username which will be sent to the server. If omitted
4143it defaults to ``qemu''.
4144
4145The @var{dir} parameter tells QEMU where to find the keys file.
4146It is called ``@var{dir}/keys.psk'' and contains ``username:key''
4147pairs. This file can most easily be created using the GnuTLS
4148@code{psktool} program.
4149
4150For server endpoints, @var{dir} may also contain a file
4151@var{dh-params.pem} providing diffie-hellman parameters to use
4152for the TLS server. If the file is missing, QEMU will generate
4153a set of DH parameters at startup. This is a computationally
4154expensive operation that consumes random pool entropy, so it is
4155recommended that a persistent set of parameters be generated
4156up front and saved.
4157
4158@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}
4159
4160Creates a TLS anonymous credentials object, which can be used to provide
4161TLS support on network backends. The @option{id} parameter is a unique
4162ID which network backends will use to access the credentials. The
4163@option{endpoint} is either @option{server} or @option{client} depending
4164on whether the QEMU network backend that uses the credentials will be
4165acting as a client or as a server. If @option{verify-peer} is enabled
4166(the default) then once the handshake is completed, the peer credentials
4167will be verified. With x509 certificates, this implies that the clients
4168must be provided with valid client certificates too.
4169
4170The @var{dir} parameter tells QEMU where to find the credential
4171files. For server endpoints, this directory may contain a file
4172@var{dh-params.pem} providing diffie-hellman parameters to use
4173for the TLS server. If the file is missing, QEMU will generate
4174a set of DH parameters at startup. This is a computationally
4175expensive operation that consumes random pool entropy, so it is
4176recommended that a persistent set of parameters be generated
4177upfront and saved.
4178
4179For x509 certificate credentials the directory will contain further files
4180providing the x509 certificates. The certificates must be stored
4181in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4182@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4183@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4184
4185For the @var{server-key.pem} and @var{client-key.pem} files which
4186contain sensitive private keys, it is possible to use an encrypted
4187version by providing the @var{passwordid} parameter. This provides
4188the ID of a previously created @code{secret} object containing the
4189password for decryption.
4190
4191The @var{priority} parameter allows to override the global default
4192priority used by gnutls. This can be useful if the system administrator
4193needs to use a weaker set of crypto priorities for QEMU without
4194potentially forcing the weakness onto all applications. Or conversely
4195if one wants wants a stronger default for QEMU than for all other
4196applications, they can do this through this parameter. Its format is
4197a gnutls priority string as described at
4198@url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4199
4200@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4201
4202Interval @var{t} can't be 0, this filter batches the packet delivery: all
4203packets arriving in a given interval on netdev @var{netdevid} are delayed
4204until the end of the interval. Interval is in microseconds.
4205@option{status} is optional that indicate whether the netfilter is
4206on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4207
4208queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4209
4210@option{all}: the filter is attached both to the receive and the transmit
4211 queue of the netdev (default).
4212
4213@option{rx}: the filter is attached to the receive queue of the netdev,
4214 where it will receive packets sent to the netdev.
4215
4216@option{tx}: the filter is attached to the transmit queue of the netdev,
4217 where it will receive packets sent by the netdev.
4218
4219@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4220
4221filter-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.
4222
4223@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4224
4225filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4226@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4227filter-redirector will redirect packet with vnet_hdr_len.
4228Create a filter-redirector we need to differ outdev id from indev id, id can not
4229be the same. we can just use indev or outdev, but at least one of indev or outdev
4230need to be specified.
4231
4232@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4233
4234Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4235secondary from primary to keep secondary tcp connection,and rewrite
4236tcp packet to primary from secondary make tcp packet can be handled by
4237client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4238
4239usage:
4240colo secondary:
4241-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4242-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4243-object filter-rewriter,id=rew0,netdev=hn0,queue=all
4244
4245@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4246
4247Dump the network traffic on netdev @var{dev} to the file specified by
4248@var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4249The file format is libpcap, so it can be analyzed with tools such as tcpdump
4250or Wireshark.
4251
4252@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4253
4254Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4255secondary packet. If the packets are same, we will output primary
4256packet to outdev@var{chardevid}, else we will notify colo-frame
4257do checkpoint and send primary packet to outdev@var{chardevid}.
4258if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4259
4260we must use it with the help of filter-mirror and filter-redirector.
4261
4262@example
4263
4264primary:
4265-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4266-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4267-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4268-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4269-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4270-chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4271-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4272-chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4273-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4274-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4275-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4276-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4277
4278secondary:
4279-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4280-device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4281-chardev socket,id=red0,host=3.3.3.3,port=9003
4282-chardev socket,id=red1,host=3.3.3.3,port=9004
4283-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4284-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4285
4286@end example
4287
4288If you want to know the detail of above command line, you can read
4289the colo-compare git log.
4290
4291@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4292
4293Creates a cryptodev backend which executes crypto opreation from
4294the QEMU cipher APIS. The @var{id} parameter is
4295a unique ID that will be used to reference this cryptodev backend from
4296the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4297which specify the queue number of cryptodev backend, the default of
4298@var{queues} is 1.
4299
4300@example
4301
4302 # qemu-system-x86_64 \
4303 [...] \
4304 -object cryptodev-backend-builtin,id=cryptodev0 \
4305 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4306 [...]
4307@end example
4308
4309@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4310
4311Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4312The @var{id} parameter is a unique ID that will be used to reference this
4313cryptodev backend from the @option{virtio-crypto} device.
4314The chardev should be a unix domain socket backed one. The vhost-user uses
4315a specifically defined protocol to pass vhost ioctl replacement messages
4316to an application on the other end of the socket.
4317The @var{queues} parameter is optional, which specify the queue number
4318of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4319
4320@example
4321
4322 # qemu-system-x86_64 \
4323 [...] \
4324 -chardev socket,id=chardev0,path=/path/to/socket \
4325 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4326 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4327 [...]
4328@end example
4329
4330@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4331@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4332
4333Defines a secret to store a password, encryption key, or some other sensitive
4334data. The sensitive data can either be passed directly via the @var{data}
4335parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4336parameter is insecure unless the sensitive data is encrypted.
4337
4338The sensitive data can be provided in raw format (the default), or base64.
4339When encoded as JSON, the raw format only supports valid UTF-8 characters,
4340so base64 is recommended for sending binary data. QEMU will convert from
4341which ever format is provided to the format it needs internally. eg, an
4342RBD password can be provided in raw format, even though it will be base64
4343encoded when passed onto the RBD sever.
4344
4345For added protection, it is possible to encrypt the data associated with
4346a secret using the AES-256-CBC cipher. Use of encryption is indicated
4347by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4348parameter provides the ID of a previously defined secret that contains
4349the AES-256 decryption key. This key should be 32-bytes long and be
4350base64 encoded. The @var{iv} parameter provides the random initialization
4351vector used for encryption of this particular secret and should be a
4352base64 encrypted string of the 16-byte IV.
4353
4354The simplest (insecure) usage is to provide the secret inline
4355
4356@example
4357
4358 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4359
4360@end example
4361
4362The simplest secure usage is to provide the secret via a file
4363
4364 # printf "letmein" > mypasswd.txt
4365 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4366
4367For greater security, AES-256-CBC should be used. To illustrate usage,
4368consider the openssl command line tool which can encrypt the data. Note
4369that when encrypting, the plaintext must be padded to the cipher block
4370size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4371
4372First a master key needs to be created in base64 encoding:
4373
4374@example
4375 # openssl rand -base64 32 > key.b64
4376 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
4377@end example
4378
4379Each secret to be encrypted needs to have a random initialization vector
4380generated. These do not need to be kept secret
4381
4382@example
4383 # openssl rand -base64 16 > iv.b64
4384 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
4385@end example
4386
4387The secret to be defined can now be encrypted, in this case we're
4388telling openssl to base64 encode the result, but it could be left
4389as raw bytes if desired.
4390
4391@example
4392 # SECRET=$(printf "letmein" |
4393 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4394@end example
4395
4396When launching QEMU, create a master secret pointing to @code{key.b64}
4397and specify that to be used to decrypt the user password. Pass the
4398contents of @code{iv.b64} to the second secret
4399
4400@example
4401 # $QEMU \
4402 -object secret,id=secmaster0,format=base64,file=key.b64 \
4403 -object secret,id=sec0,keyid=secmaster0,format=base64,\
4404 data=$SECRET,iv=$(<iv.b64)
4405@end example
4406
4407@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}]
4408
4409Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4410to provide the guest memory encryption support on AMD processors.
4411
4412When memory encryption is enabled, one of the physical address bit (aka the
4413C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4414is used to provide the C-bit position. The C-bit position is Host family dependent
4415hence user must provide this value. On EPYC, the value should be 47.
4416
4417When memory encryption is enabled, we loose certain bits in physical address space.
4418The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4419physical address space. Similar to C-bit, the value is Host family dependent.
4420On EPYC, the value should be 5.
4421
4422The @option{sev-device} provides the device file to use for communicating with
4423the SEV firmware running inside AMD Secure Processor. The default device is
4424'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are
4425created by CCP driver.
4426
4427The @option{policy} provides the guest policy to be enforced by the SEV firmware
4428and restrict what configuration and operational commands can be performed on this
4429guest by the hypervisor. The policy should be provided by the guest owner and is
4430bound to the guest and cannot be changed throughout the lifetime of the guest.
4431The default is 0.
4432
4433If guest @option{policy} allows sharing the key with another SEV guest then
4434@option{handle} can be use to provide handle of the guest from which to share
4435the key.
4436
4437The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4438Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters
4439are used for establishing a cryptographic session with the guest owner to
4440negotiate keys used for attestation. The file must be encoded in base64.
4441
4442e.g to launch a SEV guest
4443@example
4444 # $QEMU \
4445 ......
4446 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \
4447 -machine ...,memory-encryption=sev0
4448 .....
4449
4450@end example
4451@end table
4452
4453ETEXI
4454
4455
4456HXCOMM This is the last statement. Insert new options before this line!
4457STEXI
4458@end table
4459ETEXI
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