xref: /openbmc/qemu/qemu-options.hx (revision 503bb0b9)
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("device", HAS_ARG, QEMU_OPTION_device,
458    "-device driver[,prop[=value][,...]]\n"
459    "                add device (based on driver)\n"
460    "                prop=value,... sets driver properties\n"
461    "                use '-device help' to print all possible drivers\n"
462    "                use '-device driver,help' to print all possible properties\n",
463    QEMU_ARCH_ALL)
464STEXI
465@item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
466@findex -device
467Add device @var{driver}.  @var{prop}=@var{value} sets driver
468properties.  Valid properties depend on the driver.  To get help on
469possible drivers and properties, use @code{-device help} and
470@code{-device @var{driver},help}.
471
472Some drivers are:
473@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
474
475Add an IPMI BMC.  This is a simulation of a hardware management
476interface processor that normally sits on a system.  It provides
477a watchdog and the ability to reset and power control the system.
478You need to connect this to an IPMI interface to make it useful
479
480The IPMI slave address to use for the BMC.  The default is 0x20.
481This address is the BMC's address on the I2C network of management
482controllers.  If you don't know what this means, it is safe to ignore
483it.
484
485@table @option
486@item bmc=@var{id}
487The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
488@item slave_addr=@var{val}
489Define slave address to use for the BMC.  The default is 0x20.
490@item sdrfile=@var{file}
491file containing raw Sensor Data Records (SDR) data. The default is none.
492@item fruareasize=@var{val}
493size of a Field Replaceable Unit (FRU) area.  The default is 1024.
494@item frudatafile=@var{file}
495file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
496@end table
497
498@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
499
500Add a connection to an external IPMI BMC simulator.  Instead of
501locally emulating the BMC like the above item, instead connect
502to an external entity that provides the IPMI services.
503
504A connection is made to an external BMC simulator.  If you do this, it
505is strongly recommended that you use the "reconnect=" chardev option
506to reconnect to the simulator if the connection is lost.  Note that if
507this is not used carefully, it can be a security issue, as the
508interface has the ability to send resets, NMIs, and power off the VM.
509It's best if QEMU makes a connection to an external simulator running
510on a secure port on localhost, so neither the simulator nor QEMU is
511exposed to any outside network.
512
513See the "lanserv/README.vm" file in the OpenIPMI library for more
514details on the external interface.
515
516@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
517
518Add a KCS IPMI interafce on the ISA bus.  This also adds a
519corresponding ACPI and SMBIOS entries, if appropriate.
520
521@table @option
522@item bmc=@var{id}
523The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
524@item ioport=@var{val}
525Define the I/O address of the interface.  The default is 0xca0 for KCS.
526@item irq=@var{val}
527Define the interrupt to use.  The default is 5.  To disable interrupts,
528set this to 0.
529@end table
530
531@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
532
533Like the KCS interface, but defines a BT interface.  The default port is
5340xe4 and the default interrupt is 5.
535
536ETEXI
537
538DEF("name", HAS_ARG, QEMU_OPTION_name,
539    "-name string1[,process=string2][,debug-threads=on|off]\n"
540    "                set the name of the guest\n"
541    "                string1 sets the window title and string2 the process name\n"
542    "                When debug-threads is enabled, individual threads are given a separate name\n"
543    "                NOTE: The thread names are for debugging and not a stable API.\n",
544    QEMU_ARCH_ALL)
545STEXI
546@item -name @var{name}
547@findex -name
548Sets the @var{name} of the guest.
549This name will be displayed in the SDL window caption.
550The @var{name} will also be used for the VNC server.
551Also optionally set the top visible process name in Linux.
552Naming of individual threads can also be enabled on Linux to aid debugging.
553ETEXI
554
555DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
556    "-uuid %08x-%04x-%04x-%04x-%012x\n"
557    "                specify machine UUID\n", QEMU_ARCH_ALL)
558STEXI
559@item -uuid @var{uuid}
560@findex -uuid
561Set system UUID.
562ETEXI
563
564STEXI
565@end table
566ETEXI
567DEFHEADING()
568
569DEFHEADING(Block device options:)
570STEXI
571@table @option
572ETEXI
573
574DEF("fda", HAS_ARG, QEMU_OPTION_fda,
575    "-fda/-fdb file  use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
576DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
577STEXI
578@item -fda @var{file}
579@itemx -fdb @var{file}
580@findex -fda
581@findex -fdb
582Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
583ETEXI
584
585DEF("hda", HAS_ARG, QEMU_OPTION_hda,
586    "-hda/-hdb file  use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
587DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
588DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
589    "-hdc/-hdd file  use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
590DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
591STEXI
592@item -hda @var{file}
593@itemx -hdb @var{file}
594@itemx -hdc @var{file}
595@itemx -hdd @var{file}
596@findex -hda
597@findex -hdb
598@findex -hdc
599@findex -hdd
600Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
601ETEXI
602
603DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
604    "-cdrom file     use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
605    QEMU_ARCH_ALL)
606STEXI
607@item -cdrom @var{file}
608@findex -cdrom
609Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
610@option{-cdrom} at the same time). You can use the host CD-ROM by
611using @file{/dev/cdrom} as filename (@pxref{host_drives}).
612ETEXI
613
614DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
615    "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
616    "          [,cache.direct=on|off][,cache.no-flush=on|off]\n"
617    "          [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
618    "          [,driver specific parameters...]\n"
619    "                configure a block backend\n", QEMU_ARCH_ALL)
620STEXI
621@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
622@findex -blockdev
623
624Define a new block driver node. Some of the options apply to all block drivers,
625other options are only accepted for a specific block driver. See below for a
626list of generic options and options for the most common block drivers.
627
628Options that expect a reference to another node (e.g. @code{file}) can be
629given in two ways. Either you specify the node name of an already existing node
630(file=@var{node-name}), or you define a new node inline, adding options
631for the referenced node after a dot (file.filename=@var{path},file.aio=native).
632
633A block driver node created with @option{-blockdev} can be used for a guest
634device by specifying its node name for the @code{drive} property in a
635@option{-device} argument that defines a block device.
636
637@table @option
638@item Valid options for any block driver node:
639
640@table @code
641@item driver
642Specifies the block driver to use for the given node.
643@item node-name
644This defines the name of the block driver node by which it will be referenced
645later. The name must be unique, i.e. it must not match the name of a different
646block driver node, or (if you use @option{-drive} as well) the ID of a drive.
647
648If no node name is specified, it is automatically generated. The generated node
649name is not intended to be predictable and changes between QEMU invocations.
650For the top level, an explicit node name must be specified.
651@item read-only
652Open the node read-only. Guest write attempts will fail.
653@item cache.direct
654The host page cache can be avoided with @option{cache.direct=on}. This will
655attempt to do disk IO directly to the guest's memory. QEMU may still perform an
656internal copy of the data.
657@item cache.no-flush
658In case you don't care about data integrity over host failures, you can use
659@option{cache.no-flush=on}. This option tells QEMU that it never needs to write
660any data to the disk but can instead keep things in cache. If anything goes
661wrong, like your host losing power, the disk storage getting disconnected
662accidentally, etc. your image will most probably be rendered unusable.
663@item discard=@var{discard}
664@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls
665whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
666ignored or passed to the filesystem. Some machine types may not support
667discard requests.
668@item detect-zeroes=@var{detect-zeroes}
669@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
670conversion of plain zero writes by the OS to driver specific optimized
671zero write commands. You may even choose "unmap" if @var{discard} is set
672to "unmap" to allow a zero write to be converted to an @code{unmap} operation.
673@end table
674
675@item Driver-specific options for @code{file}
676
677This is the protocol-level block driver for accessing regular files.
678
679@table @code
680@item filename
681The path to the image file in the local filesystem
682@item aio
683Specifies the AIO backend (threads/native, default: threads)
684@item locking
685Specifies whether the image file is protected with Linux OFD / POSIX locks. The
686default is to use the Linux Open File Descriptor API if available, otherwise no
687lock is applied.  (auto/on/off, default: auto)
688@end table
689Example:
690@example
691-blockdev driver=file,node-name=disk,filename=disk.img
692@end example
693
694@item Driver-specific options for @code{raw}
695
696This is the image format block driver for raw images. It is usually
697stacked on top of a protocol level block driver such as @code{file}.
698
699@table @code
700@item file
701Reference to or definition of the data source block driver node
702(e.g. a @code{file} driver node)
703@end table
704Example 1:
705@example
706-blockdev driver=file,node-name=disk_file,filename=disk.img
707-blockdev driver=raw,node-name=disk,file=disk_file
708@end example
709Example 2:
710@example
711-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
712@end example
713
714@item Driver-specific options for @code{qcow2}
715
716This is the image format block driver for qcow2 images. It is usually
717stacked on top of a protocol level block driver such as @code{file}.
718
719@table @code
720@item file
721Reference to or definition of the data source block driver node
722(e.g. a @code{file} driver node)
723
724@item backing
725Reference to or definition of the backing file block device (default is taken
726from the image file). It is allowed to pass @code{null} here in order to disable
727the default backing file.
728
729@item lazy-refcounts
730Whether to enable the lazy refcounts feature (on/off; default is taken from the
731image file)
732
733@item cache-size
734The maximum total size of the L2 table and refcount block caches in bytes
735(default: the sum of l2-cache-size and refcount-cache-size)
736
737@item l2-cache-size
738The maximum size of the L2 table cache in bytes
739(default: if cache-size is not specified - 32M on Linux platforms, and 8M on
740non-Linux platforms; otherwise, as large as possible within the cache-size,
741while permitting the requested or the minimal refcount cache size)
742
743@item refcount-cache-size
744The maximum size of the refcount block cache in bytes
745(default: 4 times the cluster size; or if cache-size is specified, the part of
746it which is not used for the L2 cache)
747
748@item cache-clean-interval
749Clean unused entries in the L2 and refcount caches. The interval is in seconds.
750The default value is 600 on supporting platforms, and 0 on other platforms.
751Setting it to 0 disables this feature.
752
753@item pass-discard-request
754Whether discard requests to the qcow2 device should be forwarded to the data
755source (on/off; default: on if discard=unmap is specified, off otherwise)
756
757@item pass-discard-snapshot
758Whether discard requests for the data source should be issued when a snapshot
759operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
760default: on)
761
762@item pass-discard-other
763Whether discard requests for the data source should be issued on other
764occasions where a cluster gets freed (on/off; default: off)
765
766@item overlap-check
767Which overlap checks to perform for writes to the image
768(none/constant/cached/all; default: cached). For details or finer
769granularity control refer to the QAPI documentation of @code{blockdev-add}.
770@end table
771
772Example 1:
773@example
774-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
775-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
776@end example
777Example 2:
778@example
779-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
780@end example
781
782@item Driver-specific options for other drivers
783Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
784
785@end table
786
787ETEXI
788
789DEF("drive", HAS_ARG, QEMU_OPTION_drive,
790    "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
791    "       [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
792    "       [,snapshot=on|off][,rerror=ignore|stop|report]\n"
793    "       [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
794    "       [,readonly=on|off][,copy-on-read=on|off]\n"
795    "       [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
796    "       [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
797    "       [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
798    "       [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
799    "       [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
800    "       [[,iops_size=is]]\n"
801    "       [[,group=g]]\n"
802    "                use 'file' as a drive image\n", QEMU_ARCH_ALL)
803STEXI
804@item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
805@findex -drive
806
807Define a new drive. This includes creating a block driver node (the backend) as
808well as a guest device, and is mostly a shortcut for defining the corresponding
809@option{-blockdev} and @option{-device} options.
810
811@option{-drive} accepts all options that are accepted by @option{-blockdev}. In
812addition, it knows the following options:
813
814@table @option
815@item file=@var{file}
816This option defines which disk image (@pxref{disk_images}) to use with
817this drive. If the filename contains comma, you must double it
818(for instance, "file=my,,file" to use file "my,file").
819
820Special files such as iSCSI devices can be specified using protocol
821specific URLs. See the section for "Device URL Syntax" for more information.
822@item if=@var{interface}
823This option defines on which type on interface the drive is connected.
824Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
825@item bus=@var{bus},unit=@var{unit}
826These options define where is connected the drive by defining the bus number and
827the unit id.
828@item index=@var{index}
829This option defines where is connected the drive by using an index in the list
830of available connectors of a given interface type.
831@item media=@var{media}
832This option defines the type of the media: disk or cdrom.
833@item snapshot=@var{snapshot}
834@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
835(see @option{-snapshot}).
836@item cache=@var{cache}
837@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
838and controls how the host cache is used to access block data. This is a
839shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
840options (as in @option{-blockdev}), and additionally @option{cache.writeback},
841which provides a default for the @option{write-cache} option of block guest
842devices (as in @option{-device}). The modes correspond to the following
843settings:
844
845@c Our texi2pod.pl script doesn't support @multitable, so fall back to using
846@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
847@c and the HTML output.
848@example
849@             │ cache.writeback   cache.direct   cache.no-flush
850─────────────┼─────────────────────────────────────────────────
851writeback    │ on                off            off
852none         │ on                on             off
853writethrough │ off               off            off
854directsync   │ off               on             off
855unsafe       │ on                off            on
856@end example
857
858The default mode is @option{cache=writeback}.
859
860@item aio=@var{aio}
861@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
862@item format=@var{format}
863Specify which disk @var{format} will be used rather than detecting
864the format.  Can be used to specify format=raw to avoid interpreting
865an untrusted format header.
866@item werror=@var{action},rerror=@var{action}
867Specify which @var{action} to take on write and read errors. Valid actions are:
868"ignore" (ignore the error and try to continue), "stop" (pause QEMU),
869"report" (report the error to the guest), "enospc" (pause QEMU only if the
870host disk is full; report the error to the guest otherwise).
871The default setting is @option{werror=enospc} and @option{rerror=report}.
872@item copy-on-read=@var{copy-on-read}
873@var{copy-on-read} is "on" or "off" and enables whether to copy read backing
874file sectors into the image file.
875@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
876Specify bandwidth throttling limits in bytes per second, either for all request
877types or for reads or writes only.  Small values can lead to timeouts or hangs
878inside the guest.  A safe minimum for disks is 2 MB/s.
879@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
880Specify bursts in bytes per second, either for all request types or for reads
881or writes only.  Bursts allow the guest I/O to spike above the limit
882temporarily.
883@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
884Specify request rate limits in requests per second, either for all request
885types or for reads or writes only.
886@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
887Specify bursts in requests per second, either for all request types or for reads
888or writes only.  Bursts allow the guest I/O to spike above the limit
889temporarily.
890@item iops_size=@var{is}
891Let every @var{is} bytes of a request count as a new request for iops
892throttling purposes.  Use this option to prevent guests from circumventing iops
893limits by sending fewer but larger requests.
894@item group=@var{g}
895Join a throttling quota group with given name @var{g}.  All drives that are
896members of the same group are accounted for together.  Use this option to
897prevent guests from circumventing throttling limits by using many small disks
898instead of a single larger disk.
899@end table
900
901By default, the @option{cache.writeback=on} mode is used. It will report data
902writes as completed as soon as the data is present in the host page cache.
903This is safe as long as your guest OS makes sure to correctly flush disk caches
904where needed. If your guest OS does not handle volatile disk write caches
905correctly and your host crashes or loses power, then the guest may experience
906data corruption.
907
908For such guests, you should consider using @option{cache.writeback=off}. This
909means that the host page cache will be used to read and write data, but write
910notification will be sent to the guest only after QEMU has made sure to flush
911each write to the disk. Be aware that this has a major impact on performance.
912
913When using the @option{-snapshot} option, unsafe caching is always used.
914
915Copy-on-read avoids accessing the same backing file sectors repeatedly and is
916useful when the backing file is over a slow network.  By default copy-on-read
917is off.
918
919Instead of @option{-cdrom} you can use:
920@example
921qemu-system-i386 -drive file=file,index=2,media=cdrom
922@end example
923
924Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
925use:
926@example
927qemu-system-i386 -drive file=file,index=0,media=disk
928qemu-system-i386 -drive file=file,index=1,media=disk
929qemu-system-i386 -drive file=file,index=2,media=disk
930qemu-system-i386 -drive file=file,index=3,media=disk
931@end example
932
933You can open an image using pre-opened file descriptors from an fd set:
934@example
935qemu-system-i386
936-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
937-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
938-drive file=/dev/fdset/2,index=0,media=disk
939@end example
940
941You can connect a CDROM to the slave of ide0:
942@example
943qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
944@end example
945
946If you don't specify the "file=" argument, you define an empty drive:
947@example
948qemu-system-i386 -drive if=ide,index=1,media=cdrom
949@end example
950
951Instead of @option{-fda}, @option{-fdb}, you can use:
952@example
953qemu-system-i386 -drive file=file,index=0,if=floppy
954qemu-system-i386 -drive file=file,index=1,if=floppy
955@end example
956
957By default, @var{interface} is "ide" and @var{index} is automatically
958incremented:
959@example
960qemu-system-i386 -drive file=a -drive file=b"
961@end example
962is interpreted like:
963@example
964qemu-system-i386 -hda a -hdb b
965@end example
966ETEXI
967
968DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
969    "-mtdblock file  use 'file' as on-board Flash memory image\n",
970    QEMU_ARCH_ALL)
971STEXI
972@item -mtdblock @var{file}
973@findex -mtdblock
974Use @var{file} as on-board Flash memory image.
975ETEXI
976
977DEF("sd", HAS_ARG, QEMU_OPTION_sd,
978    "-sd file        use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
979STEXI
980@item -sd @var{file}
981@findex -sd
982Use @var{file} as SecureDigital card image.
983ETEXI
984
985DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
986    "-pflash file    use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
987STEXI
988@item -pflash @var{file}
989@findex -pflash
990Use @var{file} as a parallel flash image.
991ETEXI
992
993DEF("snapshot", 0, QEMU_OPTION_snapshot,
994    "-snapshot       write to temporary files instead of disk image files\n",
995    QEMU_ARCH_ALL)
996STEXI
997@item -snapshot
998@findex -snapshot
999Write to temporary files instead of disk image files. In this case,
1000the raw disk image you use is not written back. You can however force
1001the write back by pressing @key{C-a s} (@pxref{disk_images}).
1002ETEXI
1003
1004DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
1005    "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1006    " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1007    " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1008    " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1009    " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1010    " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1011    " [[,throttling.iops-size=is]]\n",
1012    QEMU_ARCH_ALL)
1013
1014STEXI
1015
1016@item -fsdev @var{fsdriver},id=@var{id},path=@var{path},[security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}]
1017@findex -fsdev
1018Define a new file system device. Valid options are:
1019@table @option
1020@item @var{fsdriver}
1021This option specifies the fs driver backend to use.
1022Currently "local" and "proxy" file system drivers are supported.
1023@item id=@var{id}
1024Specifies identifier for this device
1025@item path=@var{path}
1026Specifies the export path for the file system device. Files under
1027this path will be available to the 9p client on the guest.
1028@item security_model=@var{security_model}
1029Specifies the security model to be used for this export path.
1030Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1031In "passthrough" security model, files are stored using the same
1032credentials as they are created on the guest. This requires QEMU
1033to run as root. In "mapped-xattr" security model, some of the file
1034attributes like uid, gid, mode bits and link target are stored as
1035file attributes. For "mapped-file" these attributes are stored in the
1036hidden .virtfs_metadata directory. Directories exported by this security model cannot
1037interact with other unix tools. "none" security model is same as
1038passthrough except the sever won't report failures if it fails to
1039set file attributes like ownership. Security model is mandatory
1040only for local fsdriver. Other fsdrivers (like proxy) don't take
1041security model as a parameter.
1042@item writeout=@var{writeout}
1043This is an optional argument. The only supported value is "immediate".
1044This means that host page cache will be used to read and write data but
1045write notification will be sent to the guest only when the data has been
1046reported as written by the storage subsystem.
1047@item readonly
1048Enables exporting 9p share as a readonly mount for guests. By default
1049read-write access is given.
1050@item socket=@var{socket}
1051Enables proxy filesystem driver to use passed socket file for communicating
1052with virtfs-proxy-helper
1053@item sock_fd=@var{sock_fd}
1054Enables proxy filesystem driver to use passed socket descriptor for
1055communicating with virtfs-proxy-helper. Usually a helper like libvirt
1056will create socketpair and pass one of the fds as sock_fd
1057@item fmode=@var{fmode}
1058Specifies the default mode for newly created files on the host. Works only
1059with security models "mapped-xattr" and "mapped-file".
1060@item dmode=@var{dmode}
1061Specifies the default mode for newly created directories on the host. Works
1062only with security models "mapped-xattr" and "mapped-file".
1063@end table
1064
1065-fsdev option is used along with -device driver "virtio-9p-pci".
1066@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
1067Options for virtio-9p-pci driver are:
1068@table @option
1069@item fsdev=@var{id}
1070Specifies the id value specified along with -fsdev option
1071@item mount_tag=@var{mount_tag}
1072Specifies the tag name to be used by the guest to mount this export point
1073@end table
1074
1075ETEXI
1076
1077DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
1078    "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1079    "        [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1080    QEMU_ARCH_ALL)
1081
1082STEXI
1083
1084@item -virtfs @var{fsdriver}[,path=@var{path}],mount_tag=@var{mount_tag}[,security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}]
1085@findex -virtfs
1086
1087The general form of a Virtual File system pass-through options are:
1088@table @option
1089@item @var{fsdriver}
1090This option specifies the fs driver backend to use.
1091Currently "local" and "proxy" file system drivers are supported.
1092@item id=@var{id}
1093Specifies identifier for this device
1094@item path=@var{path}
1095Specifies the export path for the file system device. Files under
1096this path will be available to the 9p client on the guest.
1097@item security_model=@var{security_model}
1098Specifies the security model to be used for this export path.
1099Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1100In "passthrough" security model, files are stored using the same
1101credentials as they are created on the guest. This requires QEMU
1102to run as root. In "mapped-xattr" security model, some of the file
1103attributes like uid, gid, mode bits and link target are stored as
1104file attributes. For "mapped-file" these attributes are stored in the
1105hidden .virtfs_metadata directory. Directories exported by this security model cannot
1106interact with other unix tools. "none" security model is same as
1107passthrough except the sever won't report failures if it fails to
1108set file attributes like ownership. Security model is mandatory only
1109for local fsdriver. Other fsdrivers (like proxy) don't take security
1110model as a parameter.
1111@item writeout=@var{writeout}
1112This is an optional argument. The only supported value is "immediate".
1113This means that host page cache will be used to read and write data but
1114write notification will be sent to the guest only when the data has been
1115reported as written by the storage subsystem.
1116@item readonly
1117Enables exporting 9p share as a readonly mount for guests. By default
1118read-write access is given.
1119@item socket=@var{socket}
1120Enables proxy filesystem driver to use passed socket file for
1121communicating with virtfs-proxy-helper. Usually a helper like libvirt
1122will create socketpair and pass one of the fds as sock_fd
1123@item sock_fd
1124Enables proxy filesystem driver to use passed 'sock_fd' as the socket
1125descriptor for interfacing with virtfs-proxy-helper
1126@item fmode=@var{fmode}
1127Specifies the default mode for newly created files on the host. Works only
1128with security models "mapped-xattr" and "mapped-file".
1129@item dmode=@var{dmode}
1130Specifies the default mode for newly created directories on the host. Works
1131only with security models "mapped-xattr" and "mapped-file".
1132@end table
1133ETEXI
1134
1135DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
1136    "-virtfs_synth Create synthetic file system image\n",
1137    QEMU_ARCH_ALL)
1138STEXI
1139@item -virtfs_synth
1140@findex -virtfs_synth
1141Create synthetic file system image
1142ETEXI
1143
1144DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1145    "-iscsi [user=user][,password=password]\n"
1146    "       [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1147    "       [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1148    "       [,timeout=timeout]\n"
1149    "                iSCSI session parameters\n", QEMU_ARCH_ALL)
1150
1151STEXI
1152@item -iscsi
1153@findex -iscsi
1154Configure iSCSI session parameters.
1155ETEXI
1156
1157STEXI
1158@end table
1159ETEXI
1160DEFHEADING()
1161
1162DEFHEADING(USB options:)
1163STEXI
1164@table @option
1165ETEXI
1166
1167DEF("usb", 0, QEMU_OPTION_usb,
1168    "-usb            enable the USB driver (if it is not used by default yet)\n",
1169    QEMU_ARCH_ALL)
1170STEXI
1171@item -usb
1172@findex -usb
1173Enable the USB driver (if it is not used by default yet).
1174ETEXI
1175
1176DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1177    "-usbdevice name add the host or guest USB device 'name'\n",
1178    QEMU_ARCH_ALL)
1179STEXI
1180
1181@item -usbdevice @var{devname}
1182@findex -usbdevice
1183Add the USB device @var{devname}. Note that this option is deprecated,
1184please use @code{-device usb-...} instead. @xref{usb_devices}.
1185
1186@table @option
1187
1188@item mouse
1189Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1190
1191@item tablet
1192Pointer device that uses absolute coordinates (like a touchscreen). This
1193means QEMU is able to report the mouse position without having to grab the
1194mouse. Also overrides the PS/2 mouse emulation when activated.
1195
1196@item braille
1197Braille device.  This will use BrlAPI to display the braille output on a real
1198or fake device.
1199
1200@end table
1201ETEXI
1202
1203STEXI
1204@end table
1205ETEXI
1206DEFHEADING()
1207
1208DEFHEADING(Display options:)
1209STEXI
1210@table @option
1211ETEXI
1212
1213DEF("display", HAS_ARG, QEMU_OPTION_display,
1214    "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1215    "            [,window_close=on|off][,gl=on|core|es|off]\n"
1216    "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1217    "-display vnc=<display>[,<optargs>]\n"
1218    "-display curses\n"
1219    "-display none\n"
1220    "-display egl-headless[,rendernode=<file>]"
1221    "                select display type\n"
1222    "The default display is equivalent to\n"
1223#if defined(CONFIG_GTK)
1224            "\t\"-display gtk\"\n"
1225#elif defined(CONFIG_SDL)
1226            "\t\"-display sdl\"\n"
1227#elif defined(CONFIG_COCOA)
1228            "\t\"-display cocoa\"\n"
1229#elif defined(CONFIG_VNC)
1230            "\t\"-vnc localhost:0,to=99,id=default\"\n"
1231#else
1232            "\t\"-display none\"\n"
1233#endif
1234    , QEMU_ARCH_ALL)
1235STEXI
1236@item -display @var{type}
1237@findex -display
1238Select type of display to use. This option is a replacement for the
1239old style -sdl/-curses/... options. Valid values for @var{type} are
1240@table @option
1241@item sdl
1242Display video output via SDL (usually in a separate graphics
1243window; see the SDL documentation for other possibilities).
1244@item curses
1245Display video output via curses. For graphics device models which
1246support a text mode, QEMU can display this output using a
1247curses/ncurses interface. Nothing is displayed when the graphics
1248device is in graphical mode or if the graphics device does not support
1249a text mode. Generally only the VGA device models support text mode.
1250@item none
1251Do not display video output. The guest will still see an emulated
1252graphics card, but its output will not be displayed to the QEMU
1253user. This option differs from the -nographic option in that it
1254only affects what is done with video output; -nographic also changes
1255the destination of the serial and parallel port data.
1256@item gtk
1257Display video output in a GTK window. This interface provides drop-down
1258menus and other UI elements to configure and control the VM during
1259runtime.
1260@item vnc
1261Start a VNC server on display <arg>
1262@item egl-headless
1263Offload all OpenGL operations to a local DRI device. For any graphical display,
1264this display needs to be paired with either VNC or SPICE displays.
1265@end table
1266ETEXI
1267
1268DEF("nographic", 0, QEMU_OPTION_nographic,
1269    "-nographic      disable graphical output and redirect serial I/Os to console\n",
1270    QEMU_ARCH_ALL)
1271STEXI
1272@item -nographic
1273@findex -nographic
1274Normally, if QEMU is compiled with graphical window support, it displays
1275output such as guest graphics, guest console, and the QEMU monitor in a
1276window. With this option, you can totally disable graphical output so
1277that QEMU is a simple command line application. The emulated serial port
1278is redirected on the console and muxed with the monitor (unless
1279redirected elsewhere explicitly). Therefore, you can still use QEMU to
1280debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1281switching between the console and monitor.
1282ETEXI
1283
1284DEF("curses", 0, QEMU_OPTION_curses,
1285    "-curses         shorthand for -display curses\n",
1286    QEMU_ARCH_ALL)
1287STEXI
1288@item -curses
1289@findex -curses
1290Normally, if QEMU is compiled with graphical window support, it displays
1291output such as guest graphics, guest console, and the QEMU monitor in a
1292window. With this option, QEMU can display the VGA output when in text
1293mode using a curses/ncurses interface. Nothing is displayed in graphical
1294mode.
1295ETEXI
1296
1297DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1298    "-alt-grab       use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1299    QEMU_ARCH_ALL)
1300STEXI
1301@item -alt-grab
1302@findex -alt-grab
1303Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1304affects the special keys (for fullscreen, monitor-mode switching, etc).
1305ETEXI
1306
1307DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1308    "-ctrl-grab      use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1309    QEMU_ARCH_ALL)
1310STEXI
1311@item -ctrl-grab
1312@findex -ctrl-grab
1313Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1314affects the special keys (for fullscreen, monitor-mode switching, etc).
1315ETEXI
1316
1317DEF("no-quit", 0, QEMU_OPTION_no_quit,
1318    "-no-quit        disable SDL window close capability\n", QEMU_ARCH_ALL)
1319STEXI
1320@item -no-quit
1321@findex -no-quit
1322Disable SDL window close capability.
1323ETEXI
1324
1325DEF("sdl", 0, QEMU_OPTION_sdl,
1326    "-sdl            shorthand for -display sdl\n", QEMU_ARCH_ALL)
1327STEXI
1328@item -sdl
1329@findex -sdl
1330Enable SDL.
1331ETEXI
1332
1333DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1334    "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1335    "       [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1336    "       [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1337    "       [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1338    "       [,tls-ciphers=<list>]\n"
1339    "       [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1340    "       [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1341    "       [,sasl][,password=<secret>][,disable-ticketing]\n"
1342    "       [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1343    "       [,jpeg-wan-compression=[auto|never|always]]\n"
1344    "       [,zlib-glz-wan-compression=[auto|never|always]]\n"
1345    "       [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1346    "       [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1347    "       [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1348    "       [,gl=[on|off]][,rendernode=<file>]\n"
1349    "   enable spice\n"
1350    "   at least one of {port, tls-port} is mandatory\n",
1351    QEMU_ARCH_ALL)
1352STEXI
1353@item -spice @var{option}[,@var{option}[,...]]
1354@findex -spice
1355Enable the spice remote desktop protocol. Valid options are
1356
1357@table @option
1358
1359@item port=<nr>
1360Set the TCP port spice is listening on for plaintext channels.
1361
1362@item addr=<addr>
1363Set the IP address spice is listening on.  Default is any address.
1364
1365@item ipv4
1366@itemx ipv6
1367@itemx unix
1368Force using the specified IP version.
1369
1370@item password=<secret>
1371Set the password you need to authenticate.
1372
1373@item sasl
1374Require that the client use SASL to authenticate with the spice.
1375The exact choice of authentication method used is controlled from the
1376system / user's SASL configuration file for the 'qemu' service. This
1377is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1378unprivileged user, an environment variable SASL_CONF_PATH can be used
1379to make it search alternate locations for the service config.
1380While some SASL auth methods can also provide data encryption (eg GSSAPI),
1381it is recommended that SASL always be combined with the 'tls' and
1382'x509' settings to enable use of SSL and server certificates. This
1383ensures a data encryption preventing compromise of authentication
1384credentials.
1385
1386@item disable-ticketing
1387Allow client connects without authentication.
1388
1389@item disable-copy-paste
1390Disable copy paste between the client and the guest.
1391
1392@item disable-agent-file-xfer
1393Disable spice-vdagent based file-xfer between the client and the guest.
1394
1395@item tls-port=<nr>
1396Set the TCP port spice is listening on for encrypted channels.
1397
1398@item x509-dir=<dir>
1399Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1400
1401@item x509-key-file=<file>
1402@itemx x509-key-password=<file>
1403@itemx x509-cert-file=<file>
1404@itemx x509-cacert-file=<file>
1405@itemx x509-dh-key-file=<file>
1406The x509 file names can also be configured individually.
1407
1408@item tls-ciphers=<list>
1409Specify which ciphers to use.
1410
1411@item tls-channel=[main|display|cursor|inputs|record|playback]
1412@itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1413Force specific channel to be used with or without TLS encryption.  The
1414options can be specified multiple times to configure multiple
1415channels.  The special name "default" can be used to set the default
1416mode.  For channels which are not explicitly forced into one mode the
1417spice client is allowed to pick tls/plaintext as he pleases.
1418
1419@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1420Configure image compression (lossless).
1421Default is auto_glz.
1422
1423@item jpeg-wan-compression=[auto|never|always]
1424@itemx zlib-glz-wan-compression=[auto|never|always]
1425Configure wan image compression (lossy for slow links).
1426Default is auto.
1427
1428@item streaming-video=[off|all|filter]
1429Configure video stream detection.  Default is off.
1430
1431@item agent-mouse=[on|off]
1432Enable/disable passing mouse events via vdagent.  Default is on.
1433
1434@item playback-compression=[on|off]
1435Enable/disable audio stream compression (using celt 0.5.1).  Default is on.
1436
1437@item seamless-migration=[on|off]
1438Enable/disable spice seamless migration. Default is off.
1439
1440@item gl=[on|off]
1441Enable/disable OpenGL context. Default is off.
1442
1443@item rendernode=<file>
1444DRM render node for OpenGL rendering. If not specified, it will pick
1445the first available. (Since 2.9)
1446
1447@end table
1448ETEXI
1449
1450DEF("portrait", 0, QEMU_OPTION_portrait,
1451    "-portrait       rotate graphical output 90 deg left (only PXA LCD)\n",
1452    QEMU_ARCH_ALL)
1453STEXI
1454@item -portrait
1455@findex -portrait
1456Rotate graphical output 90 deg left (only PXA LCD).
1457ETEXI
1458
1459DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1460    "-rotate <deg>   rotate graphical output some deg left (only PXA LCD)\n",
1461    QEMU_ARCH_ALL)
1462STEXI
1463@item -rotate @var{deg}
1464@findex -rotate
1465Rotate graphical output some deg left (only PXA LCD).
1466ETEXI
1467
1468DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1469    "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1470    "                select video card type\n", QEMU_ARCH_ALL)
1471STEXI
1472@item -vga @var{type}
1473@findex -vga
1474Select type of VGA card to emulate. Valid values for @var{type} are
1475@table @option
1476@item cirrus
1477Cirrus Logic GD5446 Video card. All Windows versions starting from
1478Windows 95 should recognize and use this graphic card. For optimal
1479performances, use 16 bit color depth in the guest and the host OS.
1480(This card was the default before QEMU 2.2)
1481@item std
1482Standard VGA card with Bochs VBE extensions.  If your guest OS
1483supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1484to use high resolution modes (>= 1280x1024x16) then you should use
1485this option. (This card is the default since QEMU 2.2)
1486@item vmware
1487VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1488recent XFree86/XOrg server or Windows guest with a driver for this
1489card.
1490@item qxl
1491QXL paravirtual graphic card.  It is VGA compatible (including VESA
14922.0 VBE support).  Works best with qxl guest drivers installed though.
1493Recommended choice when using the spice protocol.
1494@item tcx
1495(sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1496sun4m machines and offers both 8-bit and 24-bit colour depths at a
1497fixed resolution of 1024x768.
1498@item cg3
1499(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1500for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1501resolutions aimed at people wishing to run older Solaris versions.
1502@item virtio
1503Virtio VGA card.
1504@item none
1505Disable VGA card.
1506@end table
1507ETEXI
1508
1509DEF("full-screen", 0, QEMU_OPTION_full_screen,
1510    "-full-screen    start in full screen\n", QEMU_ARCH_ALL)
1511STEXI
1512@item -full-screen
1513@findex -full-screen
1514Start in full screen.
1515ETEXI
1516
1517DEF("g", 1, QEMU_OPTION_g ,
1518    "-g WxH[xDEPTH]  Set the initial graphical resolution and depth\n",
1519    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1520STEXI
1521@item -g @var{width}x@var{height}[x@var{depth}]
1522@findex -g
1523Set the initial graphical resolution and depth (PPC, SPARC only).
1524ETEXI
1525
1526DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1527    "-vnc <display>  shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1528STEXI
1529@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1530@findex -vnc
1531Normally, if QEMU is compiled with graphical window support, it displays
1532output such as guest graphics, guest console, and the QEMU monitor in a
1533window. With this option, you can have QEMU listen on VNC display
1534@var{display} and redirect the VGA display over the VNC session. It is
1535very useful to enable the usb tablet device when using this option
1536(option @option{-device usb-tablet}). When using the VNC display, you
1537must use the @option{-k} parameter to set the keyboard layout if you are
1538not using en-us. Valid syntax for the @var{display} is
1539
1540@table @option
1541
1542@item to=@var{L}
1543
1544With this option, QEMU will try next available VNC @var{display}s, until the
1545number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1546available, e.g. port 5900+@var{display} is already used by another
1547application. By default, to=0.
1548
1549@item @var{host}:@var{d}
1550
1551TCP connections will only be allowed from @var{host} on display @var{d}.
1552By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1553be omitted in which case the server will accept connections from any host.
1554
1555@item unix:@var{path}
1556
1557Connections will be allowed over UNIX domain sockets where @var{path} is the
1558location of a unix socket to listen for connections on.
1559
1560@item none
1561
1562VNC is initialized but not started. The monitor @code{change} command
1563can be used to later start the VNC server.
1564
1565@end table
1566
1567Following the @var{display} value there may be one or more @var{option} flags
1568separated by commas. Valid options are
1569
1570@table @option
1571
1572@item reverse
1573
1574Connect to a listening VNC client via a ``reverse'' connection. The
1575client is specified by the @var{display}. For reverse network
1576connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1577is a TCP port number, not a display number.
1578
1579@item websocket
1580
1581Opens an additional TCP listening port dedicated to VNC Websocket connections.
1582If a bare @var{websocket} option is given, the Websocket port is
15835700+@var{display}. An alternative port can be specified with the
1584syntax @code{websocket}=@var{port}.
1585
1586If @var{host} is specified connections will only be allowed from this host.
1587It is possible to control the websocket listen address independently, using
1588the syntax @code{websocket}=@var{host}:@var{port}.
1589
1590If no TLS credentials are provided, the websocket connection runs in
1591unencrypted mode. If TLS credentials are provided, the websocket connection
1592requires encrypted client connections.
1593
1594@item password
1595
1596Require that password based authentication is used for client connections.
1597
1598The password must be set separately using the @code{set_password} command in
1599the @ref{pcsys_monitor}. The syntax to change your password is:
1600@code{set_password <protocol> <password>} where <protocol> could be either
1601"vnc" or "spice".
1602
1603If you would like to change <protocol> password expiration, you should use
1604@code{expire_password <protocol> <expiration-time>} where expiration time could
1605be one of the following options: now, never, +seconds or UNIX time of
1606expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1607to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1608date and time).
1609
1610You can also use keywords "now" or "never" for the expiration time to
1611allow <protocol> password to expire immediately or never expire.
1612
1613@item tls-creds=@var{ID}
1614
1615Provides the ID of a set of TLS credentials to use to secure the
1616VNC server. They will apply to both the normal VNC server socket
1617and the websocket socket (if enabled). Setting TLS credentials
1618will cause the VNC server socket to enable the VeNCrypt auth
1619mechanism.  The credentials should have been previously created
1620using the @option{-object tls-creds} argument.
1621
1622@item sasl
1623
1624Require that the client use SASL to authenticate with the VNC server.
1625The exact choice of authentication method used is controlled from the
1626system / user's SASL configuration file for the 'qemu' service. This
1627is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1628unprivileged user, an environment variable SASL_CONF_PATH can be used
1629to make it search alternate locations for the service config.
1630While some SASL auth methods can also provide data encryption (eg GSSAPI),
1631it is recommended that SASL always be combined with the 'tls' and
1632'x509' settings to enable use of SSL and server certificates. This
1633ensures a data encryption preventing compromise of authentication
1634credentials. See the @ref{vnc_security} section for details on using
1635SASL authentication.
1636
1637@item acl
1638
1639Turn on access control lists for checking of the x509 client certificate
1640and SASL party. For x509 certs, the ACL check is made against the
1641certificate's distinguished name. This is something that looks like
1642@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1643made against the username, which depending on the SASL plugin, may
1644include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1645When the @option{acl} flag is set, the initial access list will be
1646empty, with a @code{deny} policy. Thus no one will be allowed to
1647use the VNC server until the ACLs have been loaded. This can be
1648achieved using the @code{acl} monitor command.
1649
1650@item lossy
1651
1652Enable lossy compression methods (gradient, JPEG, ...). If this
1653option is set, VNC client may receive lossy framebuffer updates
1654depending on its encoding settings. Enabling this option can save
1655a lot of bandwidth at the expense of quality.
1656
1657@item non-adaptive
1658
1659Disable adaptive encodings. Adaptive encodings are enabled by default.
1660An adaptive encoding will try to detect frequently updated screen regions,
1661and send updates in these regions using a lossy encoding (like JPEG).
1662This can be really helpful to save bandwidth when playing videos. Disabling
1663adaptive encodings restores the original static behavior of encodings
1664like Tight.
1665
1666@item share=[allow-exclusive|force-shared|ignore]
1667
1668Set display sharing policy.  'allow-exclusive' allows clients to ask
1669for exclusive access.  As suggested by the rfb spec this is
1670implemented by dropping other connections.  Connecting multiple
1671clients in parallel requires all clients asking for a shared session
1672(vncviewer: -shared switch).  This is the default.  'force-shared'
1673disables exclusive client access.  Useful for shared desktop sessions,
1674where you don't want someone forgetting specify -shared disconnect
1675everybody else.  'ignore' completely ignores the shared flag and
1676allows everybody connect unconditionally.  Doesn't conform to the rfb
1677spec but is traditional QEMU behavior.
1678
1679@item key-delay-ms
1680
1681Set keyboard delay, for key down and key up events, in milliseconds.
1682Default is 10.  Keyboards are low-bandwidth devices, so this slowdown
1683can help the device and guest to keep up and not lose events in case
1684events are arriving in bulk.  Possible causes for the latter are flaky
1685network connections, or scripts for automated testing.
1686
1687@end table
1688ETEXI
1689
1690STEXI
1691@end table
1692ETEXI
1693ARCHHEADING(, QEMU_ARCH_I386)
1694
1695ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1696STEXI
1697@table @option
1698ETEXI
1699
1700DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1701    "-win2k-hack     use it when installing Windows 2000 to avoid a disk full bug\n",
1702    QEMU_ARCH_I386)
1703STEXI
1704@item -win2k-hack
1705@findex -win2k-hack
1706Use it when installing Windows 2000 to avoid a disk full bug. After
1707Windows 2000 is installed, you no longer need this option (this option
1708slows down the IDE transfers).
1709ETEXI
1710
1711DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1712    "-no-fd-bootchk  disable boot signature checking for floppy disks\n",
1713    QEMU_ARCH_I386)
1714STEXI
1715@item -no-fd-bootchk
1716@findex -no-fd-bootchk
1717Disable boot signature checking for floppy disks in BIOS. May
1718be needed to boot from old floppy disks.
1719ETEXI
1720
1721DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1722           "-no-acpi        disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1723STEXI
1724@item -no-acpi
1725@findex -no-acpi
1726Disable ACPI (Advanced Configuration and Power Interface) support. Use
1727it if your guest OS complains about ACPI problems (PC target machine
1728only).
1729ETEXI
1730
1731DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1732    "-no-hpet        disable HPET\n", QEMU_ARCH_I386)
1733STEXI
1734@item -no-hpet
1735@findex -no-hpet
1736Disable HPET support.
1737ETEXI
1738
1739DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1740    "-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"
1741    "                ACPI table description\n", QEMU_ARCH_I386)
1742STEXI
1743@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}]...]
1744@findex -acpitable
1745Add ACPI table with specified header fields and context from specified files.
1746For file=, take whole ACPI table from the specified files, including all
1747ACPI headers (possible overridden by other options).
1748For data=, only data
1749portion of the table is used, all header information is specified in the
1750command line.
1751If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1752fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1753to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1754spec.
1755ETEXI
1756
1757DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1758    "-smbios file=binary\n"
1759    "                load SMBIOS entry from binary file\n"
1760    "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1761    "              [,uefi=on|off]\n"
1762    "                specify SMBIOS type 0 fields\n"
1763    "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1764    "              [,uuid=uuid][,sku=str][,family=str]\n"
1765    "                specify SMBIOS type 1 fields\n"
1766    "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1767    "              [,asset=str][,location=str]\n"
1768    "                specify SMBIOS type 2 fields\n"
1769    "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1770    "              [,sku=str]\n"
1771    "                specify SMBIOS type 3 fields\n"
1772    "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1773    "              [,asset=str][,part=str]\n"
1774    "                specify SMBIOS type 4 fields\n"
1775    "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1776    "               [,asset=str][,part=str][,speed=%d]\n"
1777    "                specify SMBIOS type 17 fields\n",
1778    QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1779STEXI
1780@item -smbios file=@var{binary}
1781@findex -smbios
1782Load SMBIOS entry from binary file.
1783
1784@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1785Specify SMBIOS type 0 fields
1786
1787@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}]
1788Specify SMBIOS type 1 fields
1789
1790@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}]
1791Specify SMBIOS type 2 fields
1792
1793@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1794Specify SMBIOS type 3 fields
1795
1796@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1797Specify SMBIOS type 4 fields
1798
1799@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}]
1800Specify SMBIOS type 17 fields
1801ETEXI
1802
1803STEXI
1804@end table
1805ETEXI
1806DEFHEADING()
1807
1808DEFHEADING(Network options:)
1809STEXI
1810@table @option
1811ETEXI
1812
1813DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1814#ifdef CONFIG_SLIRP
1815    "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1816    "         [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1817    "         [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1818    "         [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
1819    "         [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1820#ifndef _WIN32
1821                                             "[,smb=dir[,smbserver=addr]]\n"
1822#endif
1823    "                configure a user mode network backend with ID 'str',\n"
1824    "                its DHCP server and optional services\n"
1825#endif
1826#ifdef _WIN32
1827    "-netdev tap,id=str,ifname=name\n"
1828    "                configure a host TAP network backend with ID 'str'\n"
1829#else
1830    "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1831    "         [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1832    "         [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1833    "         [,poll-us=n]\n"
1834    "                configure a host TAP network backend with ID 'str'\n"
1835    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1836    "                use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1837    "                to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1838    "                to deconfigure it\n"
1839    "                use '[down]script=no' to disable script execution\n"
1840    "                use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1841    "                configure it\n"
1842    "                use 'fd=h' to connect to an already opened TAP interface\n"
1843    "                use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1844    "                use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1845    "                default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1846    "                use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1847    "                use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1848    "                use vhost=on to enable experimental in kernel accelerator\n"
1849    "                    (only has effect for virtio guests which use MSIX)\n"
1850    "                use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1851    "                use 'vhostfd=h' to connect to an already opened vhost net device\n"
1852    "                use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1853    "                use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1854    "                use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1855    "                spent on busy polling for vhost net\n"
1856    "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1857    "                configure a host TAP network backend with ID 'str' that is\n"
1858    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1859    "                using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1860#endif
1861#ifdef __linux__
1862    "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1863    "         [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1864    "         [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1865    "         [,rxcookie=rxcookie][,offset=offset]\n"
1866    "                configure a network backend with ID 'str' connected to\n"
1867    "                an Ethernet over L2TPv3 pseudowire.\n"
1868    "                Linux kernel 3.3+ as well as most routers can talk\n"
1869    "                L2TPv3. This transport allows connecting a VM to a VM,\n"
1870    "                VM to a router and even VM to Host. It is a nearly-universal\n"
1871    "                standard (RFC3391). Note - this implementation uses static\n"
1872    "                pre-configured tunnels (same as the Linux kernel).\n"
1873    "                use 'src=' to specify source address\n"
1874    "                use 'dst=' to specify destination address\n"
1875    "                use 'udp=on' to specify udp encapsulation\n"
1876    "                use 'srcport=' to specify source udp port\n"
1877    "                use 'dstport=' to specify destination udp port\n"
1878    "                use 'ipv6=on' to force v6\n"
1879    "                L2TPv3 uses cookies to prevent misconfiguration as\n"
1880    "                well as a weak security measure\n"
1881    "                use 'rxcookie=0x012345678' to specify a rxcookie\n"
1882    "                use 'txcookie=0x012345678' to specify a txcookie\n"
1883    "                use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1884    "                use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1885    "                use 'pincounter=on' to work around broken counter handling in peer\n"
1886    "                use 'offset=X' to add an extra offset between header and data\n"
1887#endif
1888    "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1889    "                configure a network backend to connect to another network\n"
1890    "                using a socket connection\n"
1891    "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1892    "                configure a network backend to connect to a multicast maddr and port\n"
1893    "                use 'localaddr=addr' to specify the host address to send packets from\n"
1894    "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1895    "                configure a network backend to connect to another network\n"
1896    "                using an UDP tunnel\n"
1897#ifdef CONFIG_VDE
1898    "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1899    "                configure a network backend to connect to port 'n' of a vde switch\n"
1900    "                running on host and listening for incoming connections on 'socketpath'.\n"
1901    "                Use group 'groupname' and mode 'octalmode' to change default\n"
1902    "                ownership and permissions for communication port.\n"
1903#endif
1904#ifdef CONFIG_NETMAP
1905    "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1906    "                attach to the existing netmap-enabled network interface 'name', or to a\n"
1907    "                VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1908    "                netmap device, defaults to '/dev/netmap')\n"
1909#endif
1910#ifdef CONFIG_POSIX
1911    "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1912    "                configure a vhost-user network, backed by a chardev 'dev'\n"
1913#endif
1914    "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
1915    "                configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
1916DEF("nic", HAS_ARG, QEMU_OPTION_nic,
1917    "-nic [tap|bridge|"
1918#ifdef CONFIG_SLIRP
1919    "user|"
1920#endif
1921#ifdef __linux__
1922    "l2tpv3|"
1923#endif
1924#ifdef CONFIG_VDE
1925    "vde|"
1926#endif
1927#ifdef CONFIG_NETMAP
1928    "netmap|"
1929#endif
1930#ifdef CONFIG_POSIX
1931    "vhost-user|"
1932#endif
1933    "socket][,option][,...][mac=macaddr]\n"
1934    "                initialize an on-board / default host NIC (using MAC address\n"
1935    "                macaddr) and connect it to the given host network backend\n"
1936    "-nic none       use it alone to have zero network devices (the default is to\n"
1937    "                provided a 'user' network connection)\n",
1938    QEMU_ARCH_ALL)
1939DEF("net", HAS_ARG, QEMU_OPTION_net,
1940    "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1941    "                configure or create an on-board (or machine default) NIC and\n"
1942    "                connect it to hub 0 (please use -nic unless you need a hub)\n"
1943    "-net ["
1944#ifdef CONFIG_SLIRP
1945    "user|"
1946#endif
1947    "tap|"
1948    "bridge|"
1949#ifdef CONFIG_VDE
1950    "vde|"
1951#endif
1952#ifdef CONFIG_NETMAP
1953    "netmap|"
1954#endif
1955    "socket][,option][,option][,...]\n"
1956    "                old way to initialize a host network interface\n"
1957    "                (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
1958STEXI
1959@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]
1960@findex -nic
1961This option is a shortcut for configuring both the on-board (default) guest
1962NIC hardware and the host network backend in one go. The host backend options
1963are the same as with the corresponding @option{-netdev} options below.
1964The guest NIC model can be set with @option{model=@var{modelname}}.
1965Use @option{model=help} to list the available device types.
1966The hardware MAC address can be set with @option{mac=@var{macaddr}}.
1967
1968The following two example do exactly the same, to show how @option{-nic} can
1969be used to shorten the command line length (note that the e1000 is the default
1970on i386, so the @option{model=e1000} parameter could even be omitted here, too):
1971@example
1972qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
1973qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
1974@end example
1975
1976@item -nic none
1977Indicate that no network devices should be configured. It is used to override
1978the default configuration (default NIC with ``user'' host network backend)
1979which is activated if no other networking options are provided.
1980
1981@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1982@findex -netdev
1983Configure user mode host network backend which requires no administrator
1984privilege to run. Valid options are:
1985
1986@table @option
1987@item id=@var{id}
1988Assign symbolic name for use in monitor commands.
1989
1990@item ipv4=on|off and ipv6=on|off
1991Specify that either IPv4 or IPv6 must be enabled. If neither is specified
1992both protocols are enabled.
1993
1994@item net=@var{addr}[/@var{mask}]
1995Set IP network address the guest will see. Optionally specify the netmask,
1996either in the form a.b.c.d or as number of valid top-most bits. Default is
199710.0.2.0/24.
1998
1999@item host=@var{addr}
2000Specify the guest-visible address of the host. Default is the 2nd IP in the
2001guest network, i.e. x.x.x.2.
2002
2003@item ipv6-net=@var{addr}[/@var{int}]
2004Set IPv6 network address the guest will see (default is fec0::/64). The
2005network prefix is given in the usual hexadecimal IPv6 address
2006notation. The prefix size is optional, and is given as the number of
2007valid top-most bits (default is 64).
2008
2009@item ipv6-host=@var{addr}
2010Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2011the guest network, i.e. xxxx::2.
2012
2013@item restrict=on|off
2014If this option is enabled, the guest will be isolated, i.e. it will not be
2015able to contact the host and no guest IP packets will be routed over the host
2016to the outside. This option does not affect any explicitly set forwarding rules.
2017
2018@item hostname=@var{name}
2019Specifies the client hostname reported by the built-in DHCP server.
2020
2021@item dhcpstart=@var{addr}
2022Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2023is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2024
2025@item dns=@var{addr}
2026Specify the guest-visible address of the virtual nameserver. The address must
2027be different from the host address. Default is the 3rd IP in the guest network,
2028i.e. x.x.x.3.
2029
2030@item ipv6-dns=@var{addr}
2031Specify the guest-visible address of the IPv6 virtual nameserver. The address
2032must be different from the host address. Default is the 3rd IP in the guest
2033network, i.e. xxxx::3.
2034
2035@item dnssearch=@var{domain}
2036Provides an entry for the domain-search list sent by the built-in
2037DHCP server. More than one domain suffix can be transmitted by specifying
2038this option multiple times. If supported, this will cause the guest to
2039automatically try to append the given domain suffix(es) in case a domain name
2040can not be resolved.
2041
2042Example:
2043@example
2044qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2045@end example
2046
2047@item domainname=@var{domain}
2048Specifies the client domain name reported by the built-in DHCP server.
2049
2050@item tftp=@var{dir}
2051When using the user mode network stack, activate a built-in TFTP
2052server. The files in @var{dir} will be exposed as the root of a TFTP server.
2053The TFTP client on the guest must be configured in binary mode (use the command
2054@code{bin} of the Unix TFTP client).
2055
2056@item tftp-server-name=@var{name}
2057In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option
205866). This can be used to advise the guest to load boot files or configurations
2059from a different server than the host address.
2060
2061@item bootfile=@var{file}
2062When using the user mode network stack, broadcast @var{file} as the BOOTP
2063filename. In conjunction with @option{tftp}, this can be used to network boot
2064a guest from a local directory.
2065
2066Example (using pxelinux):
2067@example
2068qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2069    -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2070@end example
2071
2072@item smb=@var{dir}[,smbserver=@var{addr}]
2073When using the user mode network stack, activate a built-in SMB
2074server so that Windows OSes can access to the host files in @file{@var{dir}}
2075transparently. The IP address of the SMB server can be set to @var{addr}. By
2076default the 4th IP in the guest network is used, i.e. x.x.x.4.
2077
2078In the guest Windows OS, the line:
2079@example
208010.0.2.4 smbserver
2081@end example
2082must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2083or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2084
2085Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2086
2087Note that a SAMBA server must be installed on the host OS.
2088
2089@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2090Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2091the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2092@var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2093given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2094be bound to a specific host interface. If no connection type is set, TCP is
2095used. This option can be given multiple times.
2096
2097For example, to redirect host X11 connection from screen 1 to guest
2098screen 0, use the following:
2099
2100@example
2101# on the host
2102qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2103# this host xterm should open in the guest X11 server
2104xterm -display :1
2105@end example
2106
2107To redirect telnet connections from host port 5555 to telnet port on
2108the guest, use the following:
2109
2110@example
2111# on the host
2112qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2113telnet localhost 5555
2114@end example
2115
2116Then when you use on the host @code{telnet localhost 5555}, you
2117connect to the guest telnet server.
2118
2119@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2120@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2121Forward guest TCP connections to the IP address @var{server} on port @var{port}
2122to the character device @var{dev} or to a program executed by @var{cmd:command}
2123which gets spawned for each connection. This option can be given multiple times.
2124
2125You can either use a chardev directly and have that one used throughout QEMU's
2126lifetime, like in the following example:
2127
2128@example
2129# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2130# the guest accesses it
2131qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
2132@end example
2133
2134Or you can execute a command on every TCP connection established by the guest,
2135so that QEMU behaves similar to an inetd process for that virtual server:
2136
2137@example
2138# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2139# and connect the TCP stream to its stdin/stdout
2140qemu-system-i386 -nic  'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2141@end example
2142
2143@end table
2144
2145@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2146Configure a host TAP network backend with ID @var{id}.
2147
2148Use the network script @var{file} to configure it and the network script
2149@var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2150automatically provides one. The default network configure script is
2151@file{/etc/qemu-ifup} and the default network deconfigure script is
2152@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2153to disable script execution.
2154
2155If running QEMU as an unprivileged user, use the network helper
2156@var{helper} to configure the TAP interface and attach it to the bridge.
2157The default network helper executable is @file{/path/to/qemu-bridge-helper}
2158and the default bridge device is @file{br0}.
2159
2160@option{fd}=@var{h} can be used to specify the handle of an already
2161opened host TAP interface.
2162
2163Examples:
2164
2165@example
2166#launch a QEMU instance with the default network script
2167qemu-system-i386 linux.img -nic tap
2168@end example
2169
2170@example
2171#launch a QEMU instance with two NICs, each one connected
2172#to a TAP device
2173qemu-system-i386 linux.img \
2174        -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2175        -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2176@end example
2177
2178@example
2179#launch a QEMU instance with the default network helper to
2180#connect a TAP device to bridge br0
2181qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \
2182        -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
2183@end example
2184
2185@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2186Connect a host TAP network interface to a host bridge device.
2187
2188Use the network helper @var{helper} to configure the TAP interface and
2189attach it to the bridge. The default network helper executable is
2190@file{/path/to/qemu-bridge-helper} and the default bridge
2191device is @file{br0}.
2192
2193Examples:
2194
2195@example
2196#launch a QEMU instance with the default network helper to
2197#connect a TAP device to bridge br0
2198qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
2199@end example
2200
2201@example
2202#launch a QEMU instance with the default network helper to
2203#connect a TAP device to bridge qemubr0
2204qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
2205@end example
2206
2207@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2208
2209This host network backend can be used to connect the guest's network to
2210another QEMU virtual machine using a TCP socket connection. If @option{listen}
2211is specified, QEMU waits for incoming connections on @var{port}
2212(@var{host} is optional). @option{connect} is used to connect to
2213another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2214specifies an already opened TCP socket.
2215
2216Example:
2217@example
2218# launch a first QEMU instance
2219qemu-system-i386 linux.img \
2220                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2221                 -netdev socket,id=n1,listen=:1234
2222# connect the network of this instance to the network of the first instance
2223qemu-system-i386 linux.img \
2224                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2225                 -netdev socket,id=n2,connect=127.0.0.1:1234
2226@end example
2227
2228@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2229
2230Configure a socket host network backend to share the guest's network traffic
2231with another QEMU virtual machines using a UDP multicast socket, effectively
2232making a bus for every QEMU with same multicast address @var{maddr} and @var{port}.
2233NOTES:
2234@enumerate
2235@item
2236Several QEMU can be running on different hosts and share same bus (assuming
2237correct multicast setup for these hosts).
2238@item
2239mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2240@url{http://user-mode-linux.sf.net}.
2241@item
2242Use @option{fd=h} to specify an already opened UDP multicast socket.
2243@end enumerate
2244
2245Example:
2246@example
2247# launch one QEMU instance
2248qemu-system-i386 linux.img \
2249                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2250                 -netdev socket,id=n1,mcast=230.0.0.1:1234
2251# launch another QEMU instance on same "bus"
2252qemu-system-i386 linux.img \
2253                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2254                 -netdev socket,id=n2,mcast=230.0.0.1:1234
2255# launch yet another QEMU instance on same "bus"
2256qemu-system-i386 linux.img \
2257                 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \
2258                 -netdev socket,id=n3,mcast=230.0.0.1:1234
2259@end example
2260
2261Example (User Mode Linux compat.):
2262@example
2263# launch QEMU instance (note mcast address selected is UML's default)
2264qemu-system-i386 linux.img \
2265                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2266                 -netdev socket,id=n1,mcast=239.192.168.1:1102
2267# launch UML
2268/path/to/linux ubd0=/path/to/root_fs eth0=mcast
2269@end example
2270
2271Example (send packets from host's 1.2.3.4):
2272@example
2273qemu-system-i386 linux.img \
2274                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2275                 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2276@end example
2277
2278@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}]
2279Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a
2280popular protocol to transport Ethernet (and other Layer 2) data frames between
2281two systems. It is present in routers, firewalls and the Linux kernel
2282(from version 3.3 onwards).
2283
2284This transport allows a VM to communicate to another VM, router or firewall directly.
2285
2286@table @option
2287@item src=@var{srcaddr}
2288    source address (mandatory)
2289@item dst=@var{dstaddr}
2290    destination address (mandatory)
2291@item udp
2292    select udp encapsulation (default is ip).
2293@item srcport=@var{srcport}
2294    source udp port.
2295@item dstport=@var{dstport}
2296    destination udp port.
2297@item ipv6
2298    force v6, otherwise defaults to v4.
2299@item rxcookie=@var{rxcookie}
2300@itemx txcookie=@var{txcookie}
2301    Cookies are a weak form of security in the l2tpv3 specification.
2302Their function is mostly to prevent misconfiguration. By default they are 32
2303bit.
2304@item cookie64
2305    Set cookie size to 64 bit instead of the default 32
2306@item counter=off
2307    Force a 'cut-down' L2TPv3 with no counter as in
2308draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2309@item pincounter=on
2310    Work around broken counter handling in peer. This may also help on
2311networks which have packet reorder.
2312@item offset=@var{offset}
2313    Add an extra offset between header and data
2314@end table
2315
2316For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2317on the remote Linux host 1.2.3.4:
2318@example
2319# Setup tunnel on linux host using raw ip as encapsulation
2320# on 1.2.3.4
2321ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2322    encap udp udp_sport 16384 udp_dport 16384
2323ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2324    0xFFFFFFFF peer_session_id 0xFFFFFFFF
2325ifconfig vmtunnel0 mtu 1500
2326ifconfig vmtunnel0 up
2327brctl addif br-lan vmtunnel0
2328
2329
2330# on 4.3.2.1
2331# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2332
2333qemu-system-i386 linux.img -device e1000,netdev=n1 \
2334    -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2335
2336@end example
2337
2338@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2339Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and
2340listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2341and MODE @var{octalmode} to change default ownership and permissions for
2342communication port. This option is only available if QEMU has been compiled
2343with vde support enabled.
2344
2345Example:
2346@example
2347# launch vde switch
2348vde_switch -F -sock /tmp/myswitch
2349# launch QEMU instance
2350qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch
2351@end example
2352
2353@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2354
2355Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2356be a unix domain socket backed one. The vhost-user uses a specifically defined
2357protocol to pass vhost ioctl replacement messages to an application on the other
2358end of the socket. On non-MSIX guests, the feature can be forced with
2359@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2360be created for multiqueue vhost-user.
2361
2362Example:
2363@example
2364qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2365     -numa node,memdev=mem \
2366     -chardev socket,id=chr0,path=/path/to/socket \
2367     -netdev type=vhost-user,id=net0,chardev=chr0 \
2368     -device virtio-net-pci,netdev=net0
2369@end example
2370
2371@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2372
2373Create a hub port on the emulated hub with ID @var{hubid}.
2374
2375The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2376single netdev. Alternatively, you can also connect the hubport to another
2377netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option.
2378
2379@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2380@findex -net
2381Legacy option to configure or create an on-board (or machine default) Network
2382Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e.
2383the default hub), or to the netdev @var{nd}.
2384The NIC is an e1000 by default on the PC target. Optionally, the MAC address
2385can be changed to @var{mac}, the device address set to @var{addr} (PCI cards
2386only), and a @var{name} can be assigned for use in monitor commands.
2387Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2388that the card should have; this option currently only affects virtio cards; set
2389@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2390NIC is created.  QEMU can emulate several different models of network card.
2391Use @code{-net nic,model=help} for a list of available devices for your target.
2392
2393@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}]
2394Configure a host network backend (with the options corresponding to the same
2395@option{-netdev} option) and connect it to the emulated hub 0 (the default
2396hub). Use @var{name} to specify the name of the hub port.
2397ETEXI
2398
2399STEXI
2400@end table
2401ETEXI
2402DEFHEADING()
2403
2404DEFHEADING(Character device options:)
2405
2406DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2407    "-chardev help\n"
2408    "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2409    "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2410    "         [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n"
2411    "         [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2412    "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n"
2413    "         [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2414    "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2415    "         [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2416    "         [,logfile=PATH][,logappend=on|off]\n"
2417    "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2418    "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2419    "         [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2420    "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2421    "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2422    "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2423#ifdef _WIN32
2424    "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2425    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2426#else
2427    "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2428    "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2429#endif
2430#ifdef CONFIG_BRLAPI
2431    "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2432#endif
2433#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2434        || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2435    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2436    "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2437#endif
2438#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2439    "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2440    "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2441#endif
2442#if defined(CONFIG_SPICE)
2443    "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2444    "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2445#endif
2446    , QEMU_ARCH_ALL
2447)
2448
2449STEXI
2450
2451The general form of a character device option is:
2452@table @option
2453@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2454@findex -chardev
2455Backend is one of:
2456@option{null},
2457@option{socket},
2458@option{udp},
2459@option{msmouse},
2460@option{vc},
2461@option{ringbuf},
2462@option{file},
2463@option{pipe},
2464@option{console},
2465@option{serial},
2466@option{pty},
2467@option{stdio},
2468@option{braille},
2469@option{tty},
2470@option{parallel},
2471@option{parport},
2472@option{spicevmc},
2473@option{spiceport}.
2474The specific backend will determine the applicable options.
2475
2476Use @code{-chardev help} to print all available chardev backend types.
2477
2478All devices must have an id, which can be any string up to 127 characters long.
2479It is used to uniquely identify this device in other command line directives.
2480
2481A character device may be used in multiplexing mode by multiple front-ends.
2482Specify @option{mux=on} to enable this mode.
2483A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2484backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2485If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2486create a multiplexer with your specified ID, and you can then configure multiple
2487front ends to use that chardev ID for their input/output. Up to four different
2488front ends can be connected to a single multiplexed chardev. (Without
2489multiplexing enabled, a chardev can only be used by a single front end.)
2490For instance you could use this to allow a single stdio chardev to be used by
2491two serial ports and the QEMU monitor:
2492
2493@example
2494-chardev stdio,mux=on,id=char0 \
2495-mon chardev=char0,mode=readline \
2496-serial chardev:char0 \
2497-serial chardev:char0
2498@end example
2499
2500You can have more than one multiplexer in a system configuration; for instance
2501you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2502multiplexed between the QEMU monitor and a parallel port:
2503
2504@example
2505-chardev stdio,mux=on,id=char0 \
2506-mon chardev=char0,mode=readline \
2507-parallel chardev:char0 \
2508-chardev tcp,...,mux=on,id=char1 \
2509-serial chardev:char1 \
2510-serial chardev:char1
2511@end example
2512
2513When you're using a multiplexed character device, some escape sequences are
2514interpreted in the input. @xref{mux_keys, Keys in the character backend
2515multiplexer}.
2516
2517Note that some other command line options may implicitly create multiplexed
2518character backends; for instance @option{-serial mon:stdio} creates a
2519multiplexed stdio backend connected to the serial port and the QEMU monitor,
2520and @option{-nographic} also multiplexes the console and the monitor to
2521stdio.
2522
2523There is currently no support for multiplexing in the other direction
2524(where a single QEMU front end takes input and output from multiple chardevs).
2525
2526Every backend supports the @option{logfile} option, which supplies the path
2527to a file to record all data transmitted via the backend. The @option{logappend}
2528option controls whether the log file will be truncated or appended to when
2529opened.
2530
2531@end table
2532
2533The available backends are:
2534
2535@table @option
2536@item -chardev null,id=@var{id}
2537A void device. This device will not emit any data, and will drop any data it
2538receives. The null backend does not take any options.
2539
2540@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,websocket][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2541
2542Create a two-way stream socket, which can be either a TCP or a unix socket. A
2543unix socket will be created if @option{path} is specified. Behaviour is
2544undefined if TCP options are specified for a unix socket.
2545
2546@option{server} specifies that the socket shall be a listening socket.
2547
2548@option{nowait} specifies that QEMU should not block waiting for a client to
2549connect to a listening socket.
2550
2551@option{telnet} specifies that traffic on the socket should interpret telnet
2552escape sequences.
2553
2554@option{websocket} specifies that the socket uses WebSocket protocol for
2555communication.
2556
2557@option{reconnect} sets the timeout for reconnecting on non-server sockets when
2558the remote end goes away.  qemu will delay this many seconds and then attempt
2559to reconnect.  Zero disables reconnecting, and is the default.
2560
2561@option{tls-creds} requests enablement of the TLS protocol for encryption,
2562and specifies the id of the TLS credentials to use for the handshake. The
2563credentials must be previously created with the @option{-object tls-creds}
2564argument.
2565
2566TCP and unix socket options are given below:
2567
2568@table @option
2569
2570@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2571
2572@option{host} for a listening socket specifies the local address to be bound.
2573For a connecting socket species the remote host to connect to. @option{host} is
2574optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2575
2576@option{port} for a listening socket specifies the local port to be bound. For a
2577connecting socket specifies the port on the remote host to connect to.
2578@option{port} can be given as either a port number or a service name.
2579@option{port} is required.
2580
2581@option{to} is only relevant to listening sockets. If it is specified, and
2582@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2583to and including @option{to} until it succeeds. @option{to} must be specified
2584as a port number.
2585
2586@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2587If neither is specified the socket may use either protocol.
2588
2589@option{nodelay} disables the Nagle algorithm.
2590
2591@item unix options: path=@var{path}
2592
2593@option{path} specifies the local path of the unix socket. @option{path} is
2594required.
2595
2596@end table
2597
2598@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2599
2600Sends all traffic from the guest to a remote host over UDP.
2601
2602@option{host} specifies the remote host to connect to. If not specified it
2603defaults to @code{localhost}.
2604
2605@option{port} specifies the port on the remote host to connect to. @option{port}
2606is required.
2607
2608@option{localaddr} specifies the local address to bind to. If not specified it
2609defaults to @code{0.0.0.0}.
2610
2611@option{localport} specifies the local port to bind to. If not specified any
2612available local port will be used.
2613
2614@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2615If neither is specified the device may use either protocol.
2616
2617@item -chardev msmouse,id=@var{id}
2618
2619Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2620take any options.
2621
2622@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2623
2624Connect to a QEMU text console. @option{vc} may optionally be given a specific
2625size.
2626
2627@option{width} and @option{height} specify the width and height respectively of
2628the console, in pixels.
2629
2630@option{cols} and @option{rows} specify that the console be sized to fit a text
2631console with the given dimensions.
2632
2633@item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2634
2635Create a ring buffer with fixed size @option{size}.
2636@var{size} must be a power of two and defaults to @code{64K}.
2637
2638@item -chardev file,id=@var{id},path=@var{path}
2639
2640Log all traffic received from the guest to a file.
2641
2642@option{path} specifies the path of the file to be opened. This file will be
2643created if it does not already exist, and overwritten if it does. @option{path}
2644is required.
2645
2646@item -chardev pipe,id=@var{id},path=@var{path}
2647
2648Create a two-way connection to the guest. The behaviour differs slightly between
2649Windows hosts and other hosts:
2650
2651On Windows, a single duplex pipe will be created at
2652@file{\\.pipe\@option{path}}.
2653
2654On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2655@file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2656received by the guest. Data written by the guest can be read from
2657@file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2658be present.
2659
2660@option{path} forms part of the pipe path as described above. @option{path} is
2661required.
2662
2663@item -chardev console,id=@var{id}
2664
2665Send traffic from the guest to QEMU's standard output. @option{console} does not
2666take any options.
2667
2668@option{console} is only available on Windows hosts.
2669
2670@item -chardev serial,id=@var{id},path=@option{path}
2671
2672Send traffic from the guest to a serial device on the host.
2673
2674On Unix hosts serial will actually accept any tty device,
2675not only serial lines.
2676
2677@option{path} specifies the name of the serial device to open.
2678
2679@item -chardev pty,id=@var{id}
2680
2681Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2682not take any options.
2683
2684@option{pty} is not available on Windows hosts.
2685
2686@item -chardev stdio,id=@var{id}[,signal=on|off]
2687Connect to standard input and standard output of the QEMU process.
2688
2689@option{signal} controls if signals are enabled on the terminal, that includes
2690exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2691default, use @option{signal=off} to disable it.
2692
2693@item -chardev braille,id=@var{id}
2694
2695Connect to a local BrlAPI server. @option{braille} does not take any options.
2696
2697@item -chardev tty,id=@var{id},path=@var{path}
2698
2699@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2700DragonFlyBSD hosts.  It is an alias for @option{serial}.
2701
2702@option{path} specifies the path to the tty. @option{path} is required.
2703
2704@item -chardev parallel,id=@var{id},path=@var{path}
2705@itemx -chardev parport,id=@var{id},path=@var{path}
2706
2707@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2708
2709Connect to a local parallel port.
2710
2711@option{path} specifies the path to the parallel port device. @option{path} is
2712required.
2713
2714@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2715
2716@option{spicevmc} is only available when spice support is built in.
2717
2718@option{debug} debug level for spicevmc
2719
2720@option{name} name of spice channel to connect to
2721
2722Connect to a spice virtual machine channel, such as vdiport.
2723
2724@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2725
2726@option{spiceport} is only available when spice support is built in.
2727
2728@option{debug} debug level for spicevmc
2729
2730@option{name} name of spice port to connect to
2731
2732Connect to a spice port, allowing a Spice client to handle the traffic
2733identified by a name (preferably a fqdn).
2734ETEXI
2735
2736STEXI
2737@end table
2738ETEXI
2739DEFHEADING()
2740
2741DEFHEADING(Bluetooth(R) options:)
2742STEXI
2743@table @option
2744ETEXI
2745
2746DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2747    "-bt hci,null    dumb bluetooth HCI - doesn't respond to commands\n" \
2748    "-bt hci,host[:id]\n" \
2749    "                use host's HCI with the given name\n" \
2750    "-bt hci[,vlan=n]\n" \
2751    "                emulate a standard HCI in virtual scatternet 'n'\n" \
2752    "-bt vhci[,vlan=n]\n" \
2753    "                add host computer to virtual scatternet 'n' using VHCI\n" \
2754    "-bt device:dev[,vlan=n]\n" \
2755    "                emulate a bluetooth device 'dev' in scatternet 'n'\n",
2756    QEMU_ARCH_ALL)
2757STEXI
2758@item -bt hci[...]
2759@findex -bt
2760Defines the function of the corresponding Bluetooth HCI.  -bt options
2761are matched with the HCIs present in the chosen machine type.  For
2762example when emulating a machine with only one HCI built into it, only
2763the first @code{-bt hci[...]} option is valid and defines the HCI's
2764logic.  The Transport Layer is decided by the machine type.  Currently
2765the machines @code{n800} and @code{n810} have one HCI and all other
2766machines have none.
2767
2768Note: This option and the whole bluetooth subsystem is considered as deprecated.
2769If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where
2770you describe your usecase.
2771
2772@anchor{bt-hcis}
2773The following three types are recognized:
2774
2775@table @option
2776@item -bt hci,null
2777(default) The corresponding Bluetooth HCI assumes no internal logic
2778and will not respond to any HCI commands or emit events.
2779
2780@item -bt hci,host[:@var{id}]
2781(@code{bluez} only) The corresponding HCI passes commands / events
2782to / from the physical HCI identified by the name @var{id} (default:
2783@code{hci0}) on the computer running QEMU.  Only available on @code{bluez}
2784capable systems like Linux.
2785
2786@item -bt hci[,vlan=@var{n}]
2787Add a virtual, standard HCI that will participate in the Bluetooth
2788scatternet @var{n} (default @code{0}).  Similarly to @option{-net}
2789VLANs, devices inside a bluetooth network @var{n} can only communicate
2790with other devices in the same network (scatternet).
2791@end table
2792
2793@item -bt vhci[,vlan=@var{n}]
2794(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2795to the host bluetooth stack instead of to the emulated target.  This
2796allows the host and target machines to participate in a common scatternet
2797and communicate.  Requires the Linux @code{vhci} driver installed.  Can
2798be used as following:
2799
2800@example
2801qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2802@end example
2803
2804@item -bt device:@var{dev}[,vlan=@var{n}]
2805Emulate a bluetooth device @var{dev} and place it in network @var{n}
2806(default @code{0}).  QEMU can only emulate one type of bluetooth devices
2807currently:
2808
2809@table @option
2810@item keyboard
2811Virtual wireless keyboard implementing the HIDP bluetooth profile.
2812@end table
2813ETEXI
2814
2815STEXI
2816@end table
2817ETEXI
2818DEFHEADING()
2819
2820#ifdef CONFIG_TPM
2821DEFHEADING(TPM device options:)
2822
2823DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2824    "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2825    "                use path to provide path to a character device; default is /dev/tpm0\n"
2826    "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2827    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2828    "-tpmdev emulator,id=id,chardev=dev\n"
2829    "                configure the TPM device using chardev backend\n",
2830    QEMU_ARCH_ALL)
2831STEXI
2832
2833The general form of a TPM device option is:
2834@table @option
2835
2836@item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2837@findex -tpmdev
2838
2839The specific backend type will determine the applicable options.
2840The @code{-tpmdev} option creates the TPM backend and requires a
2841@code{-device} option that specifies the TPM frontend interface model.
2842
2843Use @code{-tpmdev help} to print all available TPM backend types.
2844
2845@end table
2846
2847The available backends are:
2848
2849@table @option
2850
2851@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2852
2853(Linux-host only) Enable access to the host's TPM using the passthrough
2854driver.
2855
2856@option{path} specifies the path to the host's TPM device, i.e., on
2857a Linux host this would be @code{/dev/tpm0}.
2858@option{path} is optional and by default @code{/dev/tpm0} is used.
2859
2860@option{cancel-path} specifies the path to the host TPM device's sysfs
2861entry allowing for cancellation of an ongoing TPM command.
2862@option{cancel-path} is optional and by default QEMU will search for the
2863sysfs entry to use.
2864
2865Some notes about using the host's TPM with the passthrough driver:
2866
2867The TPM device accessed by the passthrough driver must not be
2868used by any other application on the host.
2869
2870Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2871the VM's firmware (BIOS/UEFI) will not be able to initialize the
2872TPM again and may therefore not show a TPM-specific menu that would
2873otherwise allow the user to configure the TPM, e.g., allow the user to
2874enable/disable or activate/deactivate the TPM.
2875Further, if TPM ownership is released from within a VM then the host's TPM
2876will get disabled and deactivated. To enable and activate the
2877TPM again afterwards, the host has to be rebooted and the user is
2878required to enter the firmware's menu to enable and activate the TPM.
2879If the TPM is left disabled and/or deactivated most TPM commands will fail.
2880
2881To create a passthrough TPM use the following two options:
2882@example
2883-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2884@end example
2885Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2886@code{tpmdev=tpm0} in the device option.
2887
2888@item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2889
2890(Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2891chardev backend.
2892
2893@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2894
2895To create a TPM emulator backend device with chardev socket backend:
2896@example
2897
2898-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2899
2900@end example
2901
2902ETEXI
2903
2904STEXI
2905@end table
2906ETEXI
2907DEFHEADING()
2908
2909#endif
2910
2911DEFHEADING(Linux/Multiboot boot specific:)
2912STEXI
2913
2914When using these options, you can use a given Linux or Multiboot
2915kernel without installing it in the disk image. It can be useful
2916for easier testing of various kernels.
2917
2918@table @option
2919ETEXI
2920
2921DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
2922    "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
2923STEXI
2924@item -kernel @var{bzImage}
2925@findex -kernel
2926Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2927or in multiboot format.
2928ETEXI
2929
2930DEF("append", HAS_ARG, QEMU_OPTION_append, \
2931    "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
2932STEXI
2933@item -append @var{cmdline}
2934@findex -append
2935Use @var{cmdline} as kernel command line
2936ETEXI
2937
2938DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
2939           "-initrd file    use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
2940STEXI
2941@item -initrd @var{file}
2942@findex -initrd
2943Use @var{file} as initial ram disk.
2944
2945@item -initrd "@var{file1} arg=foo,@var{file2}"
2946
2947This syntax is only available with multiboot.
2948
2949Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2950first module.
2951ETEXI
2952
2953DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
2954    "-dtb    file    use 'file' as device tree image\n", QEMU_ARCH_ALL)
2955STEXI
2956@item -dtb @var{file}
2957@findex -dtb
2958Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2959on boot.
2960ETEXI
2961
2962STEXI
2963@end table
2964ETEXI
2965DEFHEADING()
2966
2967DEFHEADING(Debug/Expert options:)
2968STEXI
2969@table @option
2970ETEXI
2971
2972DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
2973    "-fw_cfg [name=]<name>,file=<file>\n"
2974    "                add named fw_cfg entry with contents from file\n"
2975    "-fw_cfg [name=]<name>,string=<str>\n"
2976    "                add named fw_cfg entry with contents from string\n",
2977    QEMU_ARCH_ALL)
2978STEXI
2979
2980@item -fw_cfg [name=]@var{name},file=@var{file}
2981@findex -fw_cfg
2982Add named fw_cfg entry with contents from file @var{file}.
2983
2984@item -fw_cfg [name=]@var{name},string=@var{str}
2985Add named fw_cfg entry with contents from string @var{str}.
2986
2987The terminating NUL character of the contents of @var{str} will not be
2988included as part of the fw_cfg item data. To insert contents with
2989embedded NUL characters, you have to use the @var{file} parameter.
2990
2991The fw_cfg entries are passed by QEMU through to the guest.
2992
2993Example:
2994@example
2995    -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
2996@end example
2997creates an fw_cfg entry named opt/com.mycompany/blob with contents
2998from ./my_blob.bin.
2999
3000ETEXI
3001
3002DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3003    "-serial dev     redirect the serial port to char device 'dev'\n",
3004    QEMU_ARCH_ALL)
3005STEXI
3006@item -serial @var{dev}
3007@findex -serial
3008Redirect the virtual serial port to host character device
3009@var{dev}. The default device is @code{vc} in graphical mode and
3010@code{stdio} in non graphical mode.
3011
3012This option can be used several times to simulate up to 4 serial
3013ports.
3014
3015Use @code{-serial none} to disable all serial ports.
3016
3017Available character devices are:
3018@table @option
3019@item vc[:@var{W}x@var{H}]
3020Virtual console. Optionally, a width and height can be given in pixel with
3021@example
3022vc:800x600
3023@end example
3024It is also possible to specify width or height in characters:
3025@example
3026vc:80Cx24C
3027@end example
3028@item pty
3029[Linux only] Pseudo TTY (a new PTY is automatically allocated)
3030@item none
3031No device is allocated.
3032@item null
3033void device
3034@item chardev:@var{id}
3035Use a named character device defined with the @code{-chardev} option.
3036@item /dev/XXX
3037[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3038parameters are set according to the emulated ones.
3039@item /dev/parport@var{N}
3040[Linux only, parallel port only] Use host parallel port
3041@var{N}. Currently SPP and EPP parallel port features can be used.
3042@item file:@var{filename}
3043Write output to @var{filename}. No character can be read.
3044@item stdio
3045[Unix only] standard input/output
3046@item pipe:@var{filename}
3047name pipe @var{filename}
3048@item COM@var{n}
3049[Windows only] Use host serial port @var{n}
3050@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3051This implements UDP Net Console.
3052When @var{remote_host} or @var{src_ip} are not specified
3053they default to @code{0.0.0.0}.
3054When not using a specified @var{src_port} a random port is automatically chosen.
3055
3056If you just want a simple readonly console you can use @code{netcat} or
3057@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3058@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3059will appear in the netconsole session.
3060
3061If you plan to send characters back via netconsole or you want to stop
3062and start QEMU a lot of times, you should have QEMU use the same
3063source port each time by using something like @code{-serial
3064udp::4555@@:4556} to QEMU. Another approach is to use a patched
3065version of netcat which can listen to a TCP port and send and receive
3066characters via udp.  If you have a patched version of netcat which
3067activates telnet remote echo and single char transfer, then you can
3068use the following options to set up a netcat redirector to allow
3069telnet on port 5555 to access the QEMU port.
3070@table @code
3071@item QEMU Options:
3072-serial udp::4555@@:4556
3073@item netcat options:
3074-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3075@item telnet options:
3076localhost 5555
3077@end table
3078
3079@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3080The TCP Net Console has two modes of operation.  It can send the serial
3081I/O to a location or wait for a connection from a location.  By default
3082the TCP Net Console is sent to @var{host} at the @var{port}.  If you use
3083the @var{server} option QEMU will wait for a client socket application
3084to connect to the port before continuing, unless the @code{nowait}
3085option was specified.  The @code{nodelay} option disables the Nagle buffering
3086algorithm.  The @code{reconnect} option only applies if @var{noserver} is
3087set, if the connection goes down it will attempt to reconnect at the
3088given interval.  If @var{host} is omitted, 0.0.0.0 is assumed. Only
3089one TCP connection at a time is accepted. You can use @code{telnet} to
3090connect to the corresponding character device.
3091@table @code
3092@item Example to send tcp console to 192.168.0.2 port 4444
3093-serial tcp:192.168.0.2:4444
3094@item Example to listen and wait on port 4444 for connection
3095-serial tcp::4444,server
3096@item Example to not wait and listen on ip 192.168.0.100 port 4444
3097-serial tcp:192.168.0.100:4444,server,nowait
3098@end table
3099
3100@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3101The telnet protocol is used instead of raw tcp sockets.  The options
3102work the same as if you had specified @code{-serial tcp}.  The
3103difference is that the port acts like a telnet server or client using
3104telnet option negotiation.  This will also allow you to send the
3105MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3106sequence.  Typically in unix telnet you do it with Control-] and then
3107type "send break" followed by pressing the enter key.
3108
3109@item websocket:@var{host}:@var{port},server[,nowait][,nodelay]
3110The WebSocket protocol is used instead of raw tcp socket. The port acts as
3111a WebSocket server. Client mode is not supported.
3112
3113@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3114A unix domain socket is used instead of a tcp socket.  The option works the
3115same as if you had specified @code{-serial tcp} except the unix domain socket
3116@var{path} is used for connections.
3117
3118@item mon:@var{dev_string}
3119This is a special option to allow the monitor to be multiplexed onto
3120another serial port.  The monitor is accessed with key sequence of
3121@key{Control-a} and then pressing @key{c}.
3122@var{dev_string} should be any one of the serial devices specified
3123above.  An example to multiplex the monitor onto a telnet server
3124listening on port 4444 would be:
3125@table @code
3126@item -serial mon:telnet::4444,server,nowait
3127@end table
3128When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3129QEMU any more but will be passed to the guest instead.
3130
3131@item braille
3132Braille device.  This will use BrlAPI to display the braille output on a real
3133or fake device.
3134
3135@item msmouse
3136Three button serial mouse. Configure the guest to use Microsoft protocol.
3137@end table
3138ETEXI
3139
3140DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3141    "-parallel dev   redirect the parallel port to char device 'dev'\n",
3142    QEMU_ARCH_ALL)
3143STEXI
3144@item -parallel @var{dev}
3145@findex -parallel
3146Redirect the virtual parallel port to host device @var{dev} (same
3147devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3148be used to use hardware devices connected on the corresponding host
3149parallel port.
3150
3151This option can be used several times to simulate up to 3 parallel
3152ports.
3153
3154Use @code{-parallel none} to disable all parallel ports.
3155ETEXI
3156
3157DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3158    "-monitor dev    redirect the monitor to char device 'dev'\n",
3159    QEMU_ARCH_ALL)
3160STEXI
3161@item -monitor @var{dev}
3162@findex -monitor
3163Redirect the monitor to host device @var{dev} (same devices as the
3164serial port).
3165The default device is @code{vc} in graphical mode and @code{stdio} in
3166non graphical mode.
3167Use @code{-monitor none} to disable the default monitor.
3168ETEXI
3169DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3170    "-qmp dev        like -monitor but opens in 'control' mode\n",
3171    QEMU_ARCH_ALL)
3172STEXI
3173@item -qmp @var{dev}
3174@findex -qmp
3175Like -monitor but opens in 'control' mode.
3176ETEXI
3177DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3178    "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3179    QEMU_ARCH_ALL)
3180STEXI
3181@item -qmp-pretty @var{dev}
3182@findex -qmp-pretty
3183Like -qmp but uses pretty JSON formatting.
3184ETEXI
3185
3186DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3187    "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3188STEXI
3189@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3190@findex -mon
3191Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3192easing human reading and debugging.
3193ETEXI
3194
3195DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3196    "-debugcon dev   redirect the debug console to char device 'dev'\n",
3197    QEMU_ARCH_ALL)
3198STEXI
3199@item -debugcon @var{dev}
3200@findex -debugcon
3201Redirect the debug console to host device @var{dev} (same devices as the
3202serial port).  The debug console is an I/O port which is typically port
32030xe9; writing to that I/O port sends output to this device.
3204The default device is @code{vc} in graphical mode and @code{stdio} in
3205non graphical mode.
3206ETEXI
3207
3208DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3209    "-pidfile file   write PID to 'file'\n", QEMU_ARCH_ALL)
3210STEXI
3211@item -pidfile @var{file}
3212@findex -pidfile
3213Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3214from a script.
3215ETEXI
3216
3217DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3218    "-singlestep     always run in singlestep mode\n", QEMU_ARCH_ALL)
3219STEXI
3220@item -singlestep
3221@findex -singlestep
3222Run the emulation in single step mode.
3223ETEXI
3224
3225DEF("preconfig", 0, QEMU_OPTION_preconfig, \
3226    "--preconfig     pause QEMU before machine is initialized (experimental)\n",
3227    QEMU_ARCH_ALL)
3228STEXI
3229@item --preconfig
3230@findex --preconfig
3231Pause QEMU for interactive configuration before the machine is created,
3232which allows querying and configuring properties that will affect
3233machine initialization.  Use QMP command 'x-exit-preconfig' to exit
3234the preconfig state and move to the next state (i.e. run guest if -S
3235isn't used or pause the second time if -S is used).  This option is
3236experimental.
3237ETEXI
3238
3239DEF("S", 0, QEMU_OPTION_S, \
3240    "-S              freeze CPU at startup (use 'c' to start execution)\n",
3241    QEMU_ARCH_ALL)
3242STEXI
3243@item -S
3244@findex -S
3245Do not start CPU at startup (you must type 'c' in the monitor).
3246ETEXI
3247
3248DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3249    "-realtime [mlock=on|off]\n"
3250    "                run qemu with realtime features\n"
3251    "                mlock=on|off controls mlock support (default: on)\n",
3252    QEMU_ARCH_ALL)
3253STEXI
3254@item -realtime mlock=on|off
3255@findex -realtime
3256Run qemu with realtime features.
3257mlocking qemu and guest memory can be enabled via @option{mlock=on}
3258(enabled by default).
3259ETEXI
3260
3261DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit,
3262    "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n"
3263    "                run qemu with overcommit hints\n"
3264    "                mem-lock=on|off controls memory lock support (default: off)\n"
3265    "                cpu-pm=on|off controls cpu power management (default: off)\n",
3266    QEMU_ARCH_ALL)
3267STEXI
3268@item -overcommit mem-lock=on|off
3269@item -overcommit cpu-pm=on|off
3270@findex -overcommit
3271Run qemu with hints about host resource overcommit. The default is
3272to assume that host overcommits all resources.
3273
3274Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled
3275by default).  This works when host memory is not overcommitted and reduces the
3276worst-case latency for guest.  This is equivalent to @option{realtime}.
3277
3278Guest ability to manage power state of host cpus (increasing latency for other
3279processes on the same host cpu, but decreasing latency for guest) can be
3280enabled via @option{cpu-pm=on} (disabled by default).  This works best when
3281host CPU is not overcommitted. When used, host estimates of CPU cycle and power
3282utilization will be incorrect, not taking into account guest idle time.
3283ETEXI
3284
3285DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3286    "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3287STEXI
3288@item -gdb @var{dev}
3289@findex -gdb
3290Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3291connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3292stdio are reasonable use case. The latter is allowing to start QEMU from
3293within gdb and establish the connection via a pipe:
3294@example
3295(gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3296@end example
3297ETEXI
3298
3299DEF("s", 0, QEMU_OPTION_s, \
3300    "-s              shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3301    QEMU_ARCH_ALL)
3302STEXI
3303@item -s
3304@findex -s
3305Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3306(@pxref{gdb_usage}).
3307ETEXI
3308
3309DEF("d", HAS_ARG, QEMU_OPTION_d, \
3310    "-d item1,...    enable logging of specified items (use '-d help' for a list of log items)\n",
3311    QEMU_ARCH_ALL)
3312STEXI
3313@item -d @var{item1}[,...]
3314@findex -d
3315Enable logging of specified items. Use '-d help' for a list of log items.
3316ETEXI
3317
3318DEF("D", HAS_ARG, QEMU_OPTION_D, \
3319    "-D logfile      output log to logfile (default stderr)\n",
3320    QEMU_ARCH_ALL)
3321STEXI
3322@item -D @var{logfile}
3323@findex -D
3324Output log in @var{logfile} instead of to stderr
3325ETEXI
3326
3327DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3328    "-dfilter range,..  filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3329    QEMU_ARCH_ALL)
3330STEXI
3331@item -dfilter @var{range1}[,...]
3332@findex -dfilter
3333Filter debug output to that relevant to a range of target addresses. The filter
3334spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3335@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3336addresses and sizes required. For example:
3337@example
3338    -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3339@end example
3340Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3341the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3342block starting at 0xffffffc00005f000.
3343ETEXI
3344
3345DEF("L", HAS_ARG, QEMU_OPTION_L, \
3346    "-L path         set the directory for the BIOS, VGA BIOS and keymaps\n",
3347    QEMU_ARCH_ALL)
3348STEXI
3349@item -L  @var{path}
3350@findex -L
3351Set the directory for the BIOS, VGA BIOS and keymaps.
3352
3353To list all the data directories, use @code{-L help}.
3354ETEXI
3355
3356DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3357    "-bios file      set the filename for the BIOS\n", QEMU_ARCH_ALL)
3358STEXI
3359@item -bios @var{file}
3360@findex -bios
3361Set the filename for the BIOS.
3362ETEXI
3363
3364DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3365    "-enable-kvm     enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3366STEXI
3367@item -enable-kvm
3368@findex -enable-kvm
3369Enable KVM full virtualization support. This option is only available
3370if KVM support is enabled when compiling.
3371ETEXI
3372
3373DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3374    "-xen-domid id   specify xen guest domain id\n", QEMU_ARCH_ALL)
3375DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3376    "-xen-attach     attach to existing xen domain\n"
3377    "                libxl will use this when starting QEMU\n",
3378    QEMU_ARCH_ALL)
3379DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3380    "-xen-domid-restrict     restrict set of available xen operations\n"
3381    "                        to specified domain id. (Does not affect\n"
3382    "                        xenpv machine type).\n",
3383    QEMU_ARCH_ALL)
3384STEXI
3385@item -xen-domid @var{id}
3386@findex -xen-domid
3387Specify xen guest domain @var{id} (XEN only).
3388@item -xen-attach
3389@findex -xen-attach
3390Attach to existing xen domain.
3391libxl will use this when starting QEMU (XEN only).
3392@findex -xen-domid-restrict
3393Restrict set of available xen operations to specified domain id (XEN only).
3394ETEXI
3395
3396DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3397    "-no-reboot      exit instead of rebooting\n", QEMU_ARCH_ALL)
3398STEXI
3399@item -no-reboot
3400@findex -no-reboot
3401Exit instead of rebooting.
3402ETEXI
3403
3404DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3405    "-no-shutdown    stop before shutdown\n", QEMU_ARCH_ALL)
3406STEXI
3407@item -no-shutdown
3408@findex -no-shutdown
3409Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3410This allows for instance switching to monitor to commit changes to the
3411disk image.
3412ETEXI
3413
3414DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3415    "-loadvm [tag|id]\n" \
3416    "                start right away with a saved state (loadvm in monitor)\n",
3417    QEMU_ARCH_ALL)
3418STEXI
3419@item -loadvm @var{file}
3420@findex -loadvm
3421Start right away with a saved state (@code{loadvm} in monitor)
3422ETEXI
3423
3424#ifndef _WIN32
3425DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3426    "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3427#endif
3428STEXI
3429@item -daemonize
3430@findex -daemonize
3431Daemonize the QEMU process after initialization.  QEMU will not detach from
3432standard IO until it is ready to receive connections on any of its devices.
3433This option is a useful way for external programs to launch QEMU without having
3434to cope with initialization race conditions.
3435ETEXI
3436
3437DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3438    "-option-rom rom load a file, rom, into the option ROM space\n",
3439    QEMU_ARCH_ALL)
3440STEXI
3441@item -option-rom @var{file}
3442@findex -option-rom
3443Load the contents of @var{file} as an option ROM.
3444This option is useful to load things like EtherBoot.
3445ETEXI
3446
3447DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3448    "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3449    "                set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3450    QEMU_ARCH_ALL)
3451
3452STEXI
3453
3454@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew]
3455@findex -rtc
3456Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3457UTC or local time, respectively. @code{localtime} is required for correct date in
3458MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the
3459format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3460
3461By default the RTC is driven by the host system time. This allows using of the
3462RTC as accurate reference clock inside the guest, specifically if the host
3463time is smoothly following an accurate external reference clock, e.g. via NTP.
3464If you want to isolate the guest time from the host, you can set @option{clock}
3465to @code{rt} instead, which provides a host monotonic clock if host support it.
3466To even prevent the RTC from progressing during suspension, you can set @option{clock}
3467to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in
3468icount mode in order to preserve determinism; however, note that in icount mode
3469the speed of the virtual clock is variable and can in general differ from the
3470host clock.
3471
3472Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3473specifically with Windows' ACPI HAL. This option will try to figure out how
3474many timer interrupts were not processed by the Windows guest and will
3475re-inject them.
3476ETEXI
3477
3478DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3479    "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3480    "                enable virtual instruction counter with 2^N clock ticks per\n" \
3481    "                instruction, enable aligning the host and virtual clocks\n" \
3482    "                or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3483STEXI
3484@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3485@findex -icount
3486Enable virtual instruction counter.  The virtual cpu will execute one
3487instruction every 2^@var{N} ns of virtual time.  If @code{auto} is specified
3488then the virtual cpu speed will be automatically adjusted to keep virtual
3489time within a few seconds of real time.
3490
3491When the virtual cpu is sleeping, the virtual time will advance at default
3492speed unless @option{sleep=on|off} is specified.
3493With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3494instantly whenever the virtual cpu goes to sleep mode and will not advance
3495if no timer is enabled. This behavior give deterministic execution times from
3496the guest point of view.
3497
3498Note that while this option can give deterministic behavior, it does not
3499provide cycle accurate emulation.  Modern CPUs contain superscalar out of
3500order cores with complex cache hierarchies.  The number of instructions
3501executed often has little or no correlation with actual performance.
3502
3503@option{align=on} will activate the delay algorithm which will try
3504to synchronise the host clock and the virtual clock. The goal is to
3505have a guest running at the real frequency imposed by the shift option.
3506Whenever the guest clock is behind the host clock and if
3507@option{align=on} is specified then we print a message to the user
3508to inform about the delay.
3509Currently this option does not work when @option{shift} is @code{auto}.
3510Note: The sync algorithm will work for those shift values for which
3511the guest clock runs ahead of the host clock. Typically this happens
3512when the shift value is high (how high depends on the host machine).
3513
3514When @option{rr} option is specified deterministic record/replay is enabled.
3515Replay log is written into @var{filename} file in record mode and
3516read from this file in replay mode.
3517
3518Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3519at the start of execution recording. In replay mode this option is used
3520to load the initial VM state.
3521ETEXI
3522
3523DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3524    "-watchdog model\n" \
3525    "                enable virtual hardware watchdog [default=none]\n",
3526    QEMU_ARCH_ALL)
3527STEXI
3528@item -watchdog @var{model}
3529@findex -watchdog
3530Create a virtual hardware watchdog device.  Once enabled (by a guest
3531action), the watchdog must be periodically polled by an agent inside
3532the guest or else the guest will be restarted. Choose a model for
3533which your guest has drivers.
3534
3535The @var{model} is the model of hardware watchdog to emulate. Use
3536@code{-watchdog help} to list available hardware models. Only one
3537watchdog can be enabled for a guest.
3538
3539The following models may be available:
3540@table @option
3541@item ib700
3542iBASE 700 is a very simple ISA watchdog with a single timer.
3543@item i6300esb
3544Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3545dual-timer watchdog.
3546@item diag288
3547A virtual watchdog for s390x backed by the diagnose 288 hypercall
3548(currently KVM only).
3549@end table
3550ETEXI
3551
3552DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3553    "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3554    "                action when watchdog fires [default=reset]\n",
3555    QEMU_ARCH_ALL)
3556STEXI
3557@item -watchdog-action @var{action}
3558@findex -watchdog-action
3559
3560The @var{action} controls what QEMU will do when the watchdog timer
3561expires.
3562The default is
3563@code{reset} (forcefully reset the guest).
3564Other possible actions are:
3565@code{shutdown} (attempt to gracefully shutdown the guest),
3566@code{poweroff} (forcefully poweroff the guest),
3567@code{inject-nmi} (inject a NMI into the guest),
3568@code{pause} (pause the guest),
3569@code{debug} (print a debug message and continue), or
3570@code{none} (do nothing).
3571
3572Note that the @code{shutdown} action requires that the guest responds
3573to ACPI signals, which it may not be able to do in the sort of
3574situations where the watchdog would have expired, and thus
3575@code{-watchdog-action shutdown} is not recommended for production use.
3576
3577Examples:
3578
3579@table @code
3580@item -watchdog i6300esb -watchdog-action pause
3581@itemx -watchdog ib700
3582@end table
3583ETEXI
3584
3585DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3586    "-echr chr       set terminal escape character instead of ctrl-a\n",
3587    QEMU_ARCH_ALL)
3588STEXI
3589
3590@item -echr @var{numeric_ascii_value}
3591@findex -echr
3592Change the escape character used for switching to the monitor when using
3593monitor and serial sharing.  The default is @code{0x01} when using the
3594@code{-nographic} option.  @code{0x01} is equal to pressing
3595@code{Control-a}.  You can select a different character from the ascii
3596control keys where 1 through 26 map to Control-a through Control-z.  For
3597instance you could use the either of the following to change the escape
3598character to Control-t.
3599@table @code
3600@item -echr 0x14
3601@itemx -echr 20
3602@end table
3603ETEXI
3604
3605DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3606    "-show-cursor    show cursor\n", QEMU_ARCH_ALL)
3607STEXI
3608@item -show-cursor
3609@findex -show-cursor
3610Show cursor.
3611ETEXI
3612
3613DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3614    "-tb-size n      set TB size\n", QEMU_ARCH_ALL)
3615STEXI
3616@item -tb-size @var{n}
3617@findex -tb-size
3618Set TB size.
3619ETEXI
3620
3621DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3622    "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3623    "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3624    "-incoming unix:socketpath\n" \
3625    "                prepare for incoming migration, listen on\n" \
3626    "                specified protocol and socket address\n" \
3627    "-incoming fd:fd\n" \
3628    "-incoming exec:cmdline\n" \
3629    "                accept incoming migration on given file descriptor\n" \
3630    "                or from given external command\n" \
3631    "-incoming defer\n" \
3632    "                wait for the URI to be specified via migrate_incoming\n",
3633    QEMU_ARCH_ALL)
3634STEXI
3635@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3636@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3637@findex -incoming
3638Prepare for incoming migration, listen on a given tcp port.
3639
3640@item -incoming unix:@var{socketpath}
3641Prepare for incoming migration, listen on a given unix socket.
3642
3643@item -incoming fd:@var{fd}
3644Accept incoming migration from a given filedescriptor.
3645
3646@item -incoming exec:@var{cmdline}
3647Accept incoming migration as an output from specified external command.
3648
3649@item -incoming defer
3650Wait for the URI to be specified via migrate_incoming.  The monitor can
3651be used to change settings (such as migration parameters) prior to issuing
3652the migrate_incoming to allow the migration to begin.
3653ETEXI
3654
3655DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3656    "-only-migratable     allow only migratable devices\n", QEMU_ARCH_ALL)
3657STEXI
3658@item -only-migratable
3659@findex -only-migratable
3660Only allow migratable devices. Devices will not be allowed to enter an
3661unmigratable state.
3662ETEXI
3663
3664DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3665    "-nodefaults     don't create default devices\n", QEMU_ARCH_ALL)
3666STEXI
3667@item -nodefaults
3668@findex -nodefaults
3669Don't create default devices. Normally, QEMU sets the default devices like serial
3670port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3671CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3672default devices.
3673ETEXI
3674
3675#ifndef _WIN32
3676DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3677    "-chroot dir     chroot to dir just before starting the VM\n",
3678    QEMU_ARCH_ALL)
3679#endif
3680STEXI
3681@item -chroot @var{dir}
3682@findex -chroot
3683Immediately before starting guest execution, chroot to the specified
3684directory.  Especially useful in combination with -runas.
3685ETEXI
3686
3687#ifndef _WIN32
3688DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3689    "-runas user     change to user id user just before starting the VM\n" \
3690    "                user can be numeric uid:gid instead\n",
3691    QEMU_ARCH_ALL)
3692#endif
3693STEXI
3694@item -runas @var{user}
3695@findex -runas
3696Immediately before starting guest execution, drop root privileges, switching
3697to the specified user.
3698ETEXI
3699
3700DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3701    "-prom-env variable=value\n"
3702    "                set OpenBIOS nvram variables\n",
3703    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3704STEXI
3705@item -prom-env @var{variable}=@var{value}
3706@findex -prom-env
3707Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3708ETEXI
3709DEF("semihosting", 0, QEMU_OPTION_semihosting,
3710    "-semihosting    semihosting mode\n",
3711    QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3712    QEMU_ARCH_MIPS)
3713STEXI
3714@item -semihosting
3715@findex -semihosting
3716Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3717ETEXI
3718DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3719    "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3720    "                semihosting configuration\n",
3721QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3722QEMU_ARCH_MIPS)
3723STEXI
3724@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3725@findex -semihosting-config
3726Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3727@table @option
3728@item target=@code{native|gdb|auto}
3729Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3730or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3731during debug sessions and @code{native} otherwise.
3732@item arg=@var{str1},arg=@var{str2},...
3733Allows the user to pass input arguments, and can be used multiple times to build
3734up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3735command line is still supported for backward compatibility. If both the
3736@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3737specified, the former is passed to semihosting as it always takes precedence.
3738@end table
3739ETEXI
3740DEF("old-param", 0, QEMU_OPTION_old_param,
3741    "-old-param      old param mode\n", QEMU_ARCH_ARM)
3742STEXI
3743@item -old-param
3744@findex -old-param (ARM)
3745Old param mode (ARM only).
3746ETEXI
3747
3748DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3749    "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3750    "          [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3751    "                Enable seccomp mode 2 system call filter (default 'off').\n" \
3752    "                use 'obsolete' to allow obsolete system calls that are provided\n" \
3753    "                    by the kernel, but typically no longer used by modern\n" \
3754    "                    C library implementations.\n" \
3755    "                use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3756    "                    its privileges by blacklisting all set*uid|gid system calls.\n" \
3757    "                    The value 'children' will deny set*uid|gid system calls for\n" \
3758    "                    main QEMU process but will allow forks and execves to run unprivileged\n" \
3759    "                use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3760    "                     blacklisting *fork and execve\n" \
3761    "                use 'resourcecontrol' to disable process affinity and schedular priority\n",
3762    QEMU_ARCH_ALL)
3763STEXI
3764@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3765@findex -sandbox
3766Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3767disable it.  The default is 'off'.
3768@table @option
3769@item obsolete=@var{string}
3770Enable Obsolete system calls
3771@item elevateprivileges=@var{string}
3772Disable set*uid|gid system calls
3773@item spawn=@var{string}
3774Disable *fork and execve
3775@item resourcecontrol=@var{string}
3776Disable process affinity and schedular priority
3777@end table
3778ETEXI
3779
3780DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3781    "-readconfig <file>\n", QEMU_ARCH_ALL)
3782STEXI
3783@item -readconfig @var{file}
3784@findex -readconfig
3785Read device configuration from @var{file}. This approach is useful when you want to spawn
3786QEMU process with many command line options but you don't want to exceed the command line
3787character limit.
3788ETEXI
3789DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3790    "-writeconfig <file>\n"
3791    "                read/write config file\n", QEMU_ARCH_ALL)
3792STEXI
3793@item -writeconfig @var{file}
3794@findex -writeconfig
3795Write device configuration to @var{file}. The @var{file} can be either filename to save
3796command line and device configuration into file or dash @code{-}) character to print the
3797output to stdout. This can be later used as input file for @code{-readconfig} option.
3798ETEXI
3799
3800DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3801    "-no-user-config\n"
3802    "                do not load default user-provided config files at startup\n",
3803    QEMU_ARCH_ALL)
3804STEXI
3805@item -no-user-config
3806@findex -no-user-config
3807The @code{-no-user-config} option makes QEMU not load any of the user-provided
3808config files on @var{sysconfdir}.
3809ETEXI
3810
3811DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3812    "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3813    "                specify tracing options\n",
3814    QEMU_ARCH_ALL)
3815STEXI
3816HXCOMM This line is not accurate, as some sub-options are backend-specific but
3817HXCOMM HX does not support conditional compilation of text.
3818@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3819@findex -trace
3820@include qemu-option-trace.texi
3821ETEXI
3822
3823HXCOMM Internal use
3824DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3825DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3826
3827#ifdef __linux__
3828DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3829    "-enable-fips    enable FIPS 140-2 compliance\n",
3830    QEMU_ARCH_ALL)
3831#endif
3832STEXI
3833@item -enable-fips
3834@findex -enable-fips
3835Enable FIPS 140-2 compliance mode.
3836ETEXI
3837
3838HXCOMM Deprecated by -machine accel=tcg property
3839DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3840
3841DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3842    "-msg timestamp[=on|off]\n"
3843    "                change the format of messages\n"
3844    "                on|off controls leading timestamps (default:on)\n",
3845    QEMU_ARCH_ALL)
3846STEXI
3847@item -msg timestamp[=on|off]
3848@findex -msg
3849prepend a timestamp to each log message.(default:on)
3850ETEXI
3851
3852DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3853    "-dump-vmstate <file>\n"
3854    "                Output vmstate information in JSON format to file.\n"
3855    "                Use the scripts/vmstate-static-checker.py file to\n"
3856    "                check for possible regressions in migration code\n"
3857    "                by comparing two such vmstate dumps.\n",
3858    QEMU_ARCH_ALL)
3859STEXI
3860@item -dump-vmstate @var{file}
3861@findex -dump-vmstate
3862Dump json-encoded vmstate information for current machine type to file
3863in @var{file}
3864ETEXI
3865
3866DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
3867    "-enable-sync-profile\n"
3868    "                enable synchronization profiling\n",
3869    QEMU_ARCH_ALL)
3870STEXI
3871@item -enable-sync-profile
3872@findex -enable-sync-profile
3873Enable synchronization profiling.
3874ETEXI
3875
3876STEXI
3877@end table
3878ETEXI
3879DEFHEADING()
3880
3881DEFHEADING(Generic object creation:)
3882STEXI
3883@table @option
3884ETEXI
3885
3886DEF("object", HAS_ARG, QEMU_OPTION_object,
3887    "-object TYPENAME[,PROP1=VALUE1,...]\n"
3888    "                create a new object of type TYPENAME setting properties\n"
3889    "                in the order they are specified.  Note that the 'id'\n"
3890    "                property must be set.  These objects are placed in the\n"
3891    "                '/objects' path.\n",
3892    QEMU_ARCH_ALL)
3893STEXI
3894@item -object @var{typename}[,@var{prop1}=@var{value1},...]
3895@findex -object
3896Create a new object of type @var{typename} setting properties
3897in the order they are specified.  Note that the 'id'
3898property must be set.  These objects are placed in the
3899'/objects' path.
3900
3901@table @option
3902
3903@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}
3904
3905Creates a memory file backend object, which can be used to back
3906the guest RAM with huge pages.
3907
3908The @option{id} parameter is a unique ID that will be used to reference this
3909memory region when configuring the @option{-numa} argument.
3910
3911The @option{size} option provides the size of the memory region, and accepts
3912common suffixes, eg @option{500M}.
3913
3914The @option{mem-path} provides the path to either a shared memory or huge page
3915filesystem mount.
3916
3917The @option{share} boolean option determines whether the memory
3918region is marked as private to QEMU, or shared. The latter allows
3919a co-operating external process to access the QEMU memory region.
3920
3921The @option{share} is also required for pvrdma devices due to
3922limitations in the RDMA API provided by Linux.
3923
3924Setting share=on might affect the ability to configure NUMA
3925bindings for the memory backend under some circumstances, see
3926Documentation/vm/numa_memory_policy.txt on the Linux kernel
3927source tree for additional details.
3928
3929Setting the @option{discard-data} boolean option to @var{on}
3930indicates that file contents can be destroyed when QEMU exits,
3931to avoid unnecessarily flushing data to the backing file.  Note
3932that @option{discard-data} is only an optimization, and QEMU
3933might not discard file contents if it aborts unexpectedly or is
3934terminated using SIGKILL.
3935
3936The @option{merge} boolean option enables memory merge, also known as
3937MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
3938memory deduplication.
3939
3940Setting the @option{dump} boolean option to @var{off} excludes the memory from
3941core dumps. This feature is also known as MADV_DONTDUMP.
3942
3943The @option{prealloc} boolean option enables memory preallocation.
3944
3945The @option{host-nodes} option binds the memory range to a list of NUMA host
3946nodes.
3947
3948The @option{policy} option sets the NUMA policy to one of the following values:
3949
3950@table @option
3951@item @var{default}
3952default host policy
3953
3954@item @var{preferred}
3955prefer the given host node list for allocation
3956
3957@item @var{bind}
3958restrict memory allocation to the given host node list
3959
3960@item @var{interleave}
3961interleave memory allocations across the given host node list
3962@end table
3963
3964The @option{align} option specifies the base address alignment when
3965QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
3966@option{2M}. Some backend store specified by @option{mem-path}
3967requires an alignment different than the default one used by QEMU, eg
3968the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
3969such cases, users can specify the required alignment via this option.
3970
3971The @option{pmem} option specifies whether the backing file specified
3972by @option{mem-path} is in host persistent memory that can be accessed
3973using the SNIA NVM programming model (e.g. Intel NVDIMM).
3974If @option{pmem} is set to 'on', QEMU will take necessary operations to
3975guarantee the persistence of its own writes to @option{mem-path}
3976(e.g. in vNVDIMM label emulation and live migration).
3977
3978@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}
3979
3980Creates a memory backend object, which can be used to back the guest RAM.
3981Memory backend objects offer more control than the @option{-m} option that is
3982traditionally used to define guest RAM. Please refer to
3983@option{memory-backend-file} for a description of the options.
3984
3985@item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},seal=@var{on|off},hugetlb=@var{on|off},hugetlbsize=@var{size}
3986
3987Creates an anonymous memory file backend object, which allows QEMU to
3988share the memory with an external process (e.g. when using
3989vhost-user). The memory is allocated with memfd and optional
3990sealing. (Linux only)
3991
3992The @option{seal} option creates a sealed-file, that will block
3993further resizing the memory ('on' by default).
3994
3995The @option{hugetlb} option specify the file to be created resides in
3996the hugetlbfs filesystem (since Linux 4.14).  Used in conjunction with
3997the @option{hugetlb} option, the @option{hugetlbsize} option specify
3998the hugetlb page size on systems that support multiple hugetlb page
3999sizes (it must be a power of 2 value supported by the system).
4000
4001In some versions of Linux, the @option{hugetlb} option is incompatible
4002with the @option{seal} option (requires at least Linux 4.16).
4003
4004Please refer to @option{memory-backend-file} for a description of the
4005other options.
4006
4007The @option{share} boolean option is @var{on} by default with memfd.
4008
4009@item -object rng-random,id=@var{id},filename=@var{/dev/random}
4010
4011Creates a random number generator backend which obtains entropy from
4012a device on the host. The @option{id} parameter is a unique ID that
4013will be used to reference this entropy backend from the @option{virtio-rng}
4014device. The @option{filename} parameter specifies which file to obtain
4015entropy from and if omitted defaults to @option{/dev/random}.
4016
4017@item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4018
4019Creates a random number generator backend which obtains entropy from
4020an external daemon running on the host. The @option{id} parameter is
4021a unique ID that will be used to reference this entropy backend from
4022the @option{virtio-rng} device. The @option{chardev} parameter is
4023the unique ID of a character device backend that provides the connection
4024to the RNG daemon.
4025
4026@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4027
4028Creates a TLS anonymous credentials object, which can be used to provide
4029TLS support on network backends. The @option{id} parameter is a unique
4030ID which network backends will use to access the credentials. The
4031@option{endpoint} is either @option{server} or @option{client} depending
4032on whether the QEMU network backend that uses the credentials will be
4033acting as a client or as a server. If @option{verify-peer} is enabled
4034(the default) then once the handshake is completed, the peer credentials
4035will be verified, though this is a no-op for anonymous credentials.
4036
4037The @var{dir} parameter tells QEMU where to find the credential
4038files. For server endpoints, this directory may contain a file
4039@var{dh-params.pem} providing diffie-hellman parameters to use
4040for the TLS server. If the file is missing, QEMU will generate
4041a set of DH parameters at startup. This is a computationally
4042expensive operation that consumes random pool entropy, so it is
4043recommended that a persistent set of parameters be generated
4044upfront and saved.
4045
4046@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}]
4047
4048Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide
4049TLS support on network backends. The @option{id} parameter is a unique
4050ID which network backends will use to access the credentials. The
4051@option{endpoint} is either @option{server} or @option{client} depending
4052on whether the QEMU network backend that uses the credentials will be
4053acting as a client or as a server. For clients only, @option{username}
4054is the username which will be sent to the server.  If omitted
4055it defaults to ``qemu''.
4056
4057The @var{dir} parameter tells QEMU where to find the keys file.
4058It is called ``@var{dir}/keys.psk'' and contains ``username:key''
4059pairs.  This file can most easily be created using the GnuTLS
4060@code{psktool} program.
4061
4062For server endpoints, @var{dir} may also contain a file
4063@var{dh-params.pem} providing diffie-hellman parameters to use
4064for the TLS server. If the file is missing, QEMU will generate
4065a set of DH parameters at startup. This is a computationally
4066expensive operation that consumes random pool entropy, so it is
4067recommended that a persistent set of parameters be generated
4068up front and saved.
4069
4070@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}
4071
4072Creates a TLS anonymous credentials object, which can be used to provide
4073TLS support on network backends. The @option{id} parameter is a unique
4074ID which network backends will use to access the credentials. The
4075@option{endpoint} is either @option{server} or @option{client} depending
4076on whether the QEMU network backend that uses the credentials will be
4077acting as a client or as a server. If @option{verify-peer} is enabled
4078(the default) then once the handshake is completed, the peer credentials
4079will be verified. With x509 certificates, this implies that the clients
4080must be provided with valid client certificates too.
4081
4082The @var{dir} parameter tells QEMU where to find the credential
4083files. For server endpoints, this directory may contain a file
4084@var{dh-params.pem} providing diffie-hellman parameters to use
4085for the TLS server. If the file is missing, QEMU will generate
4086a set of DH parameters at startup. This is a computationally
4087expensive operation that consumes random pool entropy, so it is
4088recommended that a persistent set of parameters be generated
4089upfront and saved.
4090
4091For x509 certificate credentials the directory will contain further files
4092providing the x509 certificates. The certificates must be stored
4093in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4094@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4095@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4096
4097For the @var{server-key.pem} and @var{client-key.pem} files which
4098contain sensitive private keys, it is possible to use an encrypted
4099version by providing the @var{passwordid} parameter. This provides
4100the ID of a previously created @code{secret} object containing the
4101password for decryption.
4102
4103The @var{priority} parameter allows to override the global default
4104priority used by gnutls. This can be useful if the system administrator
4105needs to use a weaker set of crypto priorities for QEMU without
4106potentially forcing the weakness onto all applications. Or conversely
4107if one wants wants a stronger default for QEMU than for all other
4108applications, they can do this through this parameter. Its format is
4109a gnutls priority string as described at
4110@url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4111
4112@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4113
4114Interval @var{t} can't be 0, this filter batches the packet delivery: all
4115packets arriving in a given interval on netdev @var{netdevid} are delayed
4116until the end of the interval. Interval is in microseconds.
4117@option{status} is optional that indicate whether the netfilter is
4118on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4119
4120queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4121
4122@option{all}: the filter is attached both to the receive and the transmit
4123              queue of the netdev (default).
4124
4125@option{rx}: the filter is attached to the receive queue of the netdev,
4126             where it will receive packets sent to the netdev.
4127
4128@option{tx}: the filter is attached to the transmit queue of the netdev,
4129             where it will receive packets sent by the netdev.
4130
4131@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4132
4133filter-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.
4134
4135@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4136
4137filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4138@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4139filter-redirector will redirect packet with vnet_hdr_len.
4140Create a filter-redirector we need to differ outdev id from indev id, id can not
4141be the same. we can just use indev or outdev, but at least one of indev or outdev
4142need to be specified.
4143
4144@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4145
4146Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4147secondary from primary to keep secondary tcp connection,and rewrite
4148tcp packet to primary from secondary make tcp packet can be handled by
4149client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4150
4151usage:
4152colo secondary:
4153-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4154-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4155-object filter-rewriter,id=rew0,netdev=hn0,queue=all
4156
4157@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4158
4159Dump the network traffic on netdev @var{dev} to the file specified by
4160@var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4161The file format is libpcap, so it can be analyzed with tools such as tcpdump
4162or Wireshark.
4163
4164@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4165
4166Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4167secondary packet. If the packets are same, we will output primary
4168packet to outdev@var{chardevid}, else we will notify colo-frame
4169do checkpoint and send primary packet to outdev@var{chardevid}.
4170if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4171
4172we must use it with the help of filter-mirror and filter-redirector.
4173
4174@example
4175
4176primary:
4177-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4178-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4179-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4180-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4181-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4182-chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4183-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4184-chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4185-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4186-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4187-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4188-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4189
4190secondary:
4191-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4192-device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4193-chardev socket,id=red0,host=3.3.3.3,port=9003
4194-chardev socket,id=red1,host=3.3.3.3,port=9004
4195-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4196-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4197
4198@end example
4199
4200If you want to know the detail of above command line, you can read
4201the colo-compare git log.
4202
4203@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4204
4205Creates a cryptodev backend which executes crypto opreation from
4206the QEMU cipher APIS. The @var{id} parameter is
4207a unique ID that will be used to reference this cryptodev backend from
4208the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4209which specify the queue number of cryptodev backend, the default of
4210@var{queues} is 1.
4211
4212@example
4213
4214 # qemu-system-x86_64 \
4215   [...] \
4216       -object cryptodev-backend-builtin,id=cryptodev0 \
4217       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4218   [...]
4219@end example
4220
4221@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4222
4223Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4224The @var{id} parameter is a unique ID that will be used to reference this
4225cryptodev backend from the @option{virtio-crypto} device.
4226The chardev should be a unix domain socket backed one. The vhost-user uses
4227a specifically defined protocol to pass vhost ioctl replacement messages
4228to an application on the other end of the socket.
4229The @var{queues} parameter is optional, which specify the queue number
4230of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4231
4232@example
4233
4234 # qemu-system-x86_64 \
4235   [...] \
4236       -chardev socket,id=chardev0,path=/path/to/socket \
4237       -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4238       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4239   [...]
4240@end example
4241
4242@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4243@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4244
4245Defines a secret to store a password, encryption key, or some other sensitive
4246data. The sensitive data can either be passed directly via the @var{data}
4247parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4248parameter is insecure unless the sensitive data is encrypted.
4249
4250The sensitive data can be provided in raw format (the default), or base64.
4251When encoded as JSON, the raw format only supports valid UTF-8 characters,
4252so base64 is recommended for sending binary data. QEMU will convert from
4253which ever format is provided to the format it needs internally. eg, an
4254RBD password can be provided in raw format, even though it will be base64
4255encoded when passed onto the RBD sever.
4256
4257For added protection, it is possible to encrypt the data associated with
4258a secret using the AES-256-CBC cipher. Use of encryption is indicated
4259by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4260parameter provides the ID of a previously defined secret that contains
4261the AES-256 decryption key. This key should be 32-bytes long and be
4262base64 encoded. The @var{iv} parameter provides the random initialization
4263vector used for encryption of this particular secret and should be a
4264base64 encrypted string of the 16-byte IV.
4265
4266The simplest (insecure) usage is to provide the secret inline
4267
4268@example
4269
4270 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4271
4272@end example
4273
4274The simplest secure usage is to provide the secret via a file
4275
4276 # printf "letmein" > mypasswd.txt
4277 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4278
4279For greater security, AES-256-CBC should be used. To illustrate usage,
4280consider the openssl command line tool which can encrypt the data. Note
4281that when encrypting, the plaintext must be padded to the cipher block
4282size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4283
4284First a master key needs to be created in base64 encoding:
4285
4286@example
4287 # openssl rand -base64 32 > key.b64
4288 # KEY=$(base64 -d key.b64 | hexdump  -v -e '/1 "%02X"')
4289@end example
4290
4291Each secret to be encrypted needs to have a random initialization vector
4292generated. These do not need to be kept secret
4293
4294@example
4295 # openssl rand -base64 16 > iv.b64
4296 # IV=$(base64 -d iv.b64 | hexdump  -v -e '/1 "%02X"')
4297@end example
4298
4299The secret to be defined can now be encrypted, in this case we're
4300telling openssl to base64 encode the result, but it could be left
4301as raw bytes if desired.
4302
4303@example
4304 # SECRET=$(printf "letmein" |
4305            openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4306@end example
4307
4308When launching QEMU, create a master secret pointing to @code{key.b64}
4309and specify that to be used to decrypt the user password. Pass the
4310contents of @code{iv.b64} to the second secret
4311
4312@example
4313 # $QEMU \
4314     -object secret,id=secmaster0,format=base64,file=key.b64 \
4315     -object secret,id=sec0,keyid=secmaster0,format=base64,\
4316         data=$SECRET,iv=$(<iv.b64)
4317@end example
4318
4319@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}]
4320
4321Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4322to provide the guest memory encryption support on AMD processors.
4323
4324When memory encryption is enabled, one of the physical address bit (aka the
4325C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4326is used to provide the C-bit position. The C-bit position is Host family dependent
4327hence user must provide this value. On EPYC, the value should be 47.
4328
4329When memory encryption is enabled, we loose certain bits in physical address space.
4330The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4331physical address space. Similar to C-bit, the value is Host family dependent.
4332On EPYC, the value should be 5.
4333
4334The @option{sev-device} provides the device file to use for communicating with
4335the SEV firmware running inside AMD Secure Processor. The default device is
4336'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are
4337created by CCP driver.
4338
4339The @option{policy} provides the guest policy to be enforced by the SEV firmware
4340and restrict what configuration and operational commands can be performed on this
4341guest by the hypervisor. The policy should be provided by the guest owner and is
4342bound to the guest and cannot be changed throughout the lifetime of the guest.
4343The default is 0.
4344
4345If guest @option{policy} allows sharing the key with another SEV guest then
4346@option{handle} can be use to provide handle of the guest from which to share
4347the key.
4348
4349The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4350Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters
4351are used for establishing a cryptographic session with the guest owner to
4352negotiate keys used for attestation. The file must be encoded in base64.
4353
4354e.g to launch a SEV guest
4355@example
4356 # $QEMU \
4357     ......
4358     -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \
4359     -machine ...,memory-encryption=sev0
4360     .....
4361
4362@end example
4363@end table
4364
4365ETEXI
4366
4367
4368HXCOMM This is the last statement. Insert new options before this line!
4369STEXI
4370@end table
4371ETEXI
4372