xref: /openbmc/qemu/qemu-options.hx (revision dd8d6a2d)
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 spice-app[,gl=on|off]\n"
1215    "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1216    "            [,window_close=on|off][,gl=on|core|es|off]\n"
1217    "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1218    "-display vnc=<display>[,<optargs>]\n"
1219    "-display curses\n"
1220    "-display none\n"
1221    "-display egl-headless[,rendernode=<file>]"
1222    "                select display type\n"
1223    "The default display is equivalent to\n"
1224#if defined(CONFIG_GTK)
1225            "\t\"-display gtk\"\n"
1226#elif defined(CONFIG_SDL)
1227            "\t\"-display sdl\"\n"
1228#elif defined(CONFIG_COCOA)
1229            "\t\"-display cocoa\"\n"
1230#elif defined(CONFIG_VNC)
1231            "\t\"-vnc localhost:0,to=99,id=default\"\n"
1232#else
1233            "\t\"-display none\"\n"
1234#endif
1235    , QEMU_ARCH_ALL)
1236STEXI
1237@item -display @var{type}
1238@findex -display
1239Select type of display to use. This option is a replacement for the
1240old style -sdl/-curses/... options. Valid values for @var{type} are
1241@table @option
1242@item sdl
1243Display video output via SDL (usually in a separate graphics
1244window; see the SDL documentation for other possibilities).
1245@item curses
1246Display video output via curses. For graphics device models which
1247support a text mode, QEMU can display this output using a
1248curses/ncurses interface. Nothing is displayed when the graphics
1249device is in graphical mode or if the graphics device does not support
1250a text mode. Generally only the VGA device models support text mode.
1251@item none
1252Do not display video output. The guest will still see an emulated
1253graphics card, but its output will not be displayed to the QEMU
1254user. This option differs from the -nographic option in that it
1255only affects what is done with video output; -nographic also changes
1256the destination of the serial and parallel port data.
1257@item gtk
1258Display video output in a GTK window. This interface provides drop-down
1259menus and other UI elements to configure and control the VM during
1260runtime.
1261@item vnc
1262Start a VNC server on display <arg>
1263@item egl-headless
1264Offload all OpenGL operations to a local DRI device. For any graphical display,
1265this display needs to be paired with either VNC or SPICE displays.
1266@item spice-app
1267Start QEMU as a Spice server and launch the default Spice client
1268application. The Spice server will redirect the serial consoles and
1269QEMU monitors. (Since 4.0)
1270@end table
1271ETEXI
1272
1273DEF("nographic", 0, QEMU_OPTION_nographic,
1274    "-nographic      disable graphical output and redirect serial I/Os to console\n",
1275    QEMU_ARCH_ALL)
1276STEXI
1277@item -nographic
1278@findex -nographic
1279Normally, if QEMU is compiled with graphical window support, it displays
1280output such as guest graphics, guest console, and the QEMU monitor in a
1281window. With this option, you can totally disable graphical output so
1282that QEMU is a simple command line application. The emulated serial port
1283is redirected on the console and muxed with the monitor (unless
1284redirected elsewhere explicitly). Therefore, you can still use QEMU to
1285debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1286switching between the console and monitor.
1287ETEXI
1288
1289DEF("curses", 0, QEMU_OPTION_curses,
1290    "-curses         shorthand for -display curses\n",
1291    QEMU_ARCH_ALL)
1292STEXI
1293@item -curses
1294@findex -curses
1295Normally, if QEMU is compiled with graphical window support, it displays
1296output such as guest graphics, guest console, and the QEMU monitor in a
1297window. With this option, QEMU can display the VGA output when in text
1298mode using a curses/ncurses interface. Nothing is displayed in graphical
1299mode.
1300ETEXI
1301
1302DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1303    "-alt-grab       use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1304    QEMU_ARCH_ALL)
1305STEXI
1306@item -alt-grab
1307@findex -alt-grab
1308Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1309affects the special keys (for fullscreen, monitor-mode switching, etc).
1310ETEXI
1311
1312DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1313    "-ctrl-grab      use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1314    QEMU_ARCH_ALL)
1315STEXI
1316@item -ctrl-grab
1317@findex -ctrl-grab
1318Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1319affects the special keys (for fullscreen, monitor-mode switching, etc).
1320ETEXI
1321
1322DEF("no-quit", 0, QEMU_OPTION_no_quit,
1323    "-no-quit        disable SDL window close capability\n", QEMU_ARCH_ALL)
1324STEXI
1325@item -no-quit
1326@findex -no-quit
1327Disable SDL window close capability.
1328ETEXI
1329
1330DEF("sdl", 0, QEMU_OPTION_sdl,
1331    "-sdl            shorthand for -display sdl\n", QEMU_ARCH_ALL)
1332STEXI
1333@item -sdl
1334@findex -sdl
1335Enable SDL.
1336ETEXI
1337
1338DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1339    "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1340    "       [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1341    "       [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1342    "       [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1343    "       [,tls-ciphers=<list>]\n"
1344    "       [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1345    "       [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1346    "       [,sasl][,password=<secret>][,disable-ticketing]\n"
1347    "       [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1348    "       [,jpeg-wan-compression=[auto|never|always]]\n"
1349    "       [,zlib-glz-wan-compression=[auto|never|always]]\n"
1350    "       [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1351    "       [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1352    "       [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1353    "       [,gl=[on|off]][,rendernode=<file>]\n"
1354    "   enable spice\n"
1355    "   at least one of {port, tls-port} is mandatory\n",
1356    QEMU_ARCH_ALL)
1357STEXI
1358@item -spice @var{option}[,@var{option}[,...]]
1359@findex -spice
1360Enable the spice remote desktop protocol. Valid options are
1361
1362@table @option
1363
1364@item port=<nr>
1365Set the TCP port spice is listening on for plaintext channels.
1366
1367@item addr=<addr>
1368Set the IP address spice is listening on.  Default is any address.
1369
1370@item ipv4
1371@itemx ipv6
1372@itemx unix
1373Force using the specified IP version.
1374
1375@item password=<secret>
1376Set the password you need to authenticate.
1377
1378@item sasl
1379Require that the client use SASL to authenticate with the spice.
1380The exact choice of authentication method used is controlled from the
1381system / user's SASL configuration file for the 'qemu' service. This
1382is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1383unprivileged user, an environment variable SASL_CONF_PATH can be used
1384to make it search alternate locations for the service config.
1385While some SASL auth methods can also provide data encryption (eg GSSAPI),
1386it is recommended that SASL always be combined with the 'tls' and
1387'x509' settings to enable use of SSL and server certificates. This
1388ensures a data encryption preventing compromise of authentication
1389credentials.
1390
1391@item disable-ticketing
1392Allow client connects without authentication.
1393
1394@item disable-copy-paste
1395Disable copy paste between the client and the guest.
1396
1397@item disable-agent-file-xfer
1398Disable spice-vdagent based file-xfer between the client and the guest.
1399
1400@item tls-port=<nr>
1401Set the TCP port spice is listening on for encrypted channels.
1402
1403@item x509-dir=<dir>
1404Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1405
1406@item x509-key-file=<file>
1407@itemx x509-key-password=<file>
1408@itemx x509-cert-file=<file>
1409@itemx x509-cacert-file=<file>
1410@itemx x509-dh-key-file=<file>
1411The x509 file names can also be configured individually.
1412
1413@item tls-ciphers=<list>
1414Specify which ciphers to use.
1415
1416@item tls-channel=[main|display|cursor|inputs|record|playback]
1417@itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1418Force specific channel to be used with or without TLS encryption.  The
1419options can be specified multiple times to configure multiple
1420channels.  The special name "default" can be used to set the default
1421mode.  For channels which are not explicitly forced into one mode the
1422spice client is allowed to pick tls/plaintext as he pleases.
1423
1424@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1425Configure image compression (lossless).
1426Default is auto_glz.
1427
1428@item jpeg-wan-compression=[auto|never|always]
1429@itemx zlib-glz-wan-compression=[auto|never|always]
1430Configure wan image compression (lossy for slow links).
1431Default is auto.
1432
1433@item streaming-video=[off|all|filter]
1434Configure video stream detection.  Default is off.
1435
1436@item agent-mouse=[on|off]
1437Enable/disable passing mouse events via vdagent.  Default is on.
1438
1439@item playback-compression=[on|off]
1440Enable/disable audio stream compression (using celt 0.5.1).  Default is on.
1441
1442@item seamless-migration=[on|off]
1443Enable/disable spice seamless migration. Default is off.
1444
1445@item gl=[on|off]
1446Enable/disable OpenGL context. Default is off.
1447
1448@item rendernode=<file>
1449DRM render node for OpenGL rendering. If not specified, it will pick
1450the first available. (Since 2.9)
1451
1452@end table
1453ETEXI
1454
1455DEF("portrait", 0, QEMU_OPTION_portrait,
1456    "-portrait       rotate graphical output 90 deg left (only PXA LCD)\n",
1457    QEMU_ARCH_ALL)
1458STEXI
1459@item -portrait
1460@findex -portrait
1461Rotate graphical output 90 deg left (only PXA LCD).
1462ETEXI
1463
1464DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1465    "-rotate <deg>   rotate graphical output some deg left (only PXA LCD)\n",
1466    QEMU_ARCH_ALL)
1467STEXI
1468@item -rotate @var{deg}
1469@findex -rotate
1470Rotate graphical output some deg left (only PXA LCD).
1471ETEXI
1472
1473DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1474    "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1475    "                select video card type\n", QEMU_ARCH_ALL)
1476STEXI
1477@item -vga @var{type}
1478@findex -vga
1479Select type of VGA card to emulate. Valid values for @var{type} are
1480@table @option
1481@item cirrus
1482Cirrus Logic GD5446 Video card. All Windows versions starting from
1483Windows 95 should recognize and use this graphic card. For optimal
1484performances, use 16 bit color depth in the guest and the host OS.
1485(This card was the default before QEMU 2.2)
1486@item std
1487Standard VGA card with Bochs VBE extensions.  If your guest OS
1488supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1489to use high resolution modes (>= 1280x1024x16) then you should use
1490this option. (This card is the default since QEMU 2.2)
1491@item vmware
1492VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1493recent XFree86/XOrg server or Windows guest with a driver for this
1494card.
1495@item qxl
1496QXL paravirtual graphic card.  It is VGA compatible (including VESA
14972.0 VBE support).  Works best with qxl guest drivers installed though.
1498Recommended choice when using the spice protocol.
1499@item tcx
1500(sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1501sun4m machines and offers both 8-bit and 24-bit colour depths at a
1502fixed resolution of 1024x768.
1503@item cg3
1504(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1505for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1506resolutions aimed at people wishing to run older Solaris versions.
1507@item virtio
1508Virtio VGA card.
1509@item none
1510Disable VGA card.
1511@end table
1512ETEXI
1513
1514DEF("full-screen", 0, QEMU_OPTION_full_screen,
1515    "-full-screen    start in full screen\n", QEMU_ARCH_ALL)
1516STEXI
1517@item -full-screen
1518@findex -full-screen
1519Start in full screen.
1520ETEXI
1521
1522DEF("g", 1, QEMU_OPTION_g ,
1523    "-g WxH[xDEPTH]  Set the initial graphical resolution and depth\n",
1524    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1525STEXI
1526@item -g @var{width}x@var{height}[x@var{depth}]
1527@findex -g
1528Set the initial graphical resolution and depth (PPC, SPARC only).
1529ETEXI
1530
1531DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1532    "-vnc <display>  shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1533STEXI
1534@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1535@findex -vnc
1536Normally, if QEMU is compiled with graphical window support, it displays
1537output such as guest graphics, guest console, and the QEMU monitor in a
1538window. With this option, you can have QEMU listen on VNC display
1539@var{display} and redirect the VGA display over the VNC session. It is
1540very useful to enable the usb tablet device when using this option
1541(option @option{-device usb-tablet}). When using the VNC display, you
1542must use the @option{-k} parameter to set the keyboard layout if you are
1543not using en-us. Valid syntax for the @var{display} is
1544
1545@table @option
1546
1547@item to=@var{L}
1548
1549With this option, QEMU will try next available VNC @var{display}s, until the
1550number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1551available, e.g. port 5900+@var{display} is already used by another
1552application. By default, to=0.
1553
1554@item @var{host}:@var{d}
1555
1556TCP connections will only be allowed from @var{host} on display @var{d}.
1557By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1558be omitted in which case the server will accept connections from any host.
1559
1560@item unix:@var{path}
1561
1562Connections will be allowed over UNIX domain sockets where @var{path} is the
1563location of a unix socket to listen for connections on.
1564
1565@item none
1566
1567VNC is initialized but not started. The monitor @code{change} command
1568can be used to later start the VNC server.
1569
1570@end table
1571
1572Following the @var{display} value there may be one or more @var{option} flags
1573separated by commas. Valid options are
1574
1575@table @option
1576
1577@item reverse
1578
1579Connect to a listening VNC client via a ``reverse'' connection. The
1580client is specified by the @var{display}. For reverse network
1581connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1582is a TCP port number, not a display number.
1583
1584@item websocket
1585
1586Opens an additional TCP listening port dedicated to VNC Websocket connections.
1587If a bare @var{websocket} option is given, the Websocket port is
15885700+@var{display}. An alternative port can be specified with the
1589syntax @code{websocket}=@var{port}.
1590
1591If @var{host} is specified connections will only be allowed from this host.
1592It is possible to control the websocket listen address independently, using
1593the syntax @code{websocket}=@var{host}:@var{port}.
1594
1595If no TLS credentials are provided, the websocket connection runs in
1596unencrypted mode. If TLS credentials are provided, the websocket connection
1597requires encrypted client connections.
1598
1599@item password
1600
1601Require that password based authentication is used for client connections.
1602
1603The password must be set separately using the @code{set_password} command in
1604the @ref{pcsys_monitor}. The syntax to change your password is:
1605@code{set_password <protocol> <password>} where <protocol> could be either
1606"vnc" or "spice".
1607
1608If you would like to change <protocol> password expiration, you should use
1609@code{expire_password <protocol> <expiration-time>} where expiration time could
1610be one of the following options: now, never, +seconds or UNIX time of
1611expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1612to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1613date and time).
1614
1615You can also use keywords "now" or "never" for the expiration time to
1616allow <protocol> password to expire immediately or never expire.
1617
1618@item tls-creds=@var{ID}
1619
1620Provides the ID of a set of TLS credentials to use to secure the
1621VNC server. They will apply to both the normal VNC server socket
1622and the websocket socket (if enabled). Setting TLS credentials
1623will cause the VNC server socket to enable the VeNCrypt auth
1624mechanism.  The credentials should have been previously created
1625using the @option{-object tls-creds} argument.
1626
1627@item sasl
1628
1629Require that the client use SASL to authenticate with the VNC server.
1630The exact choice of authentication method used is controlled from the
1631system / user's SASL configuration file for the 'qemu' service. This
1632is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1633unprivileged user, an environment variable SASL_CONF_PATH can be used
1634to make it search alternate locations for the service config.
1635While some SASL auth methods can also provide data encryption (eg GSSAPI),
1636it is recommended that SASL always be combined with the 'tls' and
1637'x509' settings to enable use of SSL and server certificates. This
1638ensures a data encryption preventing compromise of authentication
1639credentials. See the @ref{vnc_security} section for details on using
1640SASL authentication.
1641
1642@item acl
1643
1644Turn on access control lists for checking of the x509 client certificate
1645and SASL party. For x509 certs, the ACL check is made against the
1646certificate's distinguished name. This is something that looks like
1647@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1648made against the username, which depending on the SASL plugin, may
1649include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1650When the @option{acl} flag is set, the initial access list will be
1651empty, with a @code{deny} policy. Thus no one will be allowed to
1652use the VNC server until the ACLs have been loaded. This can be
1653achieved using the @code{acl} monitor command.
1654
1655@item lossy
1656
1657Enable lossy compression methods (gradient, JPEG, ...). If this
1658option is set, VNC client may receive lossy framebuffer updates
1659depending on its encoding settings. Enabling this option can save
1660a lot of bandwidth at the expense of quality.
1661
1662@item non-adaptive
1663
1664Disable adaptive encodings. Adaptive encodings are enabled by default.
1665An adaptive encoding will try to detect frequently updated screen regions,
1666and send updates in these regions using a lossy encoding (like JPEG).
1667This can be really helpful to save bandwidth when playing videos. Disabling
1668adaptive encodings restores the original static behavior of encodings
1669like Tight.
1670
1671@item share=[allow-exclusive|force-shared|ignore]
1672
1673Set display sharing policy.  'allow-exclusive' allows clients to ask
1674for exclusive access.  As suggested by the rfb spec this is
1675implemented by dropping other connections.  Connecting multiple
1676clients in parallel requires all clients asking for a shared session
1677(vncviewer: -shared switch).  This is the default.  'force-shared'
1678disables exclusive client access.  Useful for shared desktop sessions,
1679where you don't want someone forgetting specify -shared disconnect
1680everybody else.  'ignore' completely ignores the shared flag and
1681allows everybody connect unconditionally.  Doesn't conform to the rfb
1682spec but is traditional QEMU behavior.
1683
1684@item key-delay-ms
1685
1686Set keyboard delay, for key down and key up events, in milliseconds.
1687Default is 10.  Keyboards are low-bandwidth devices, so this slowdown
1688can help the device and guest to keep up and not lose events in case
1689events are arriving in bulk.  Possible causes for the latter are flaky
1690network connections, or scripts for automated testing.
1691
1692@end table
1693ETEXI
1694
1695STEXI
1696@end table
1697ETEXI
1698ARCHHEADING(, QEMU_ARCH_I386)
1699
1700ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1701STEXI
1702@table @option
1703ETEXI
1704
1705DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1706    "-win2k-hack     use it when installing Windows 2000 to avoid a disk full bug\n",
1707    QEMU_ARCH_I386)
1708STEXI
1709@item -win2k-hack
1710@findex -win2k-hack
1711Use it when installing Windows 2000 to avoid a disk full bug. After
1712Windows 2000 is installed, you no longer need this option (this option
1713slows down the IDE transfers).
1714ETEXI
1715
1716DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1717    "-no-fd-bootchk  disable boot signature checking for floppy disks\n",
1718    QEMU_ARCH_I386)
1719STEXI
1720@item -no-fd-bootchk
1721@findex -no-fd-bootchk
1722Disable boot signature checking for floppy disks in BIOS. May
1723be needed to boot from old floppy disks.
1724ETEXI
1725
1726DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1727           "-no-acpi        disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1728STEXI
1729@item -no-acpi
1730@findex -no-acpi
1731Disable ACPI (Advanced Configuration and Power Interface) support. Use
1732it if your guest OS complains about ACPI problems (PC target machine
1733only).
1734ETEXI
1735
1736DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1737    "-no-hpet        disable HPET\n", QEMU_ARCH_I386)
1738STEXI
1739@item -no-hpet
1740@findex -no-hpet
1741Disable HPET support.
1742ETEXI
1743
1744DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1745    "-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"
1746    "                ACPI table description\n", QEMU_ARCH_I386)
1747STEXI
1748@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}]...]
1749@findex -acpitable
1750Add ACPI table with specified header fields and context from specified files.
1751For file=, take whole ACPI table from the specified files, including all
1752ACPI headers (possible overridden by other options).
1753For data=, only data
1754portion of the table is used, all header information is specified in the
1755command line.
1756If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1757fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1758to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1759spec.
1760ETEXI
1761
1762DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1763    "-smbios file=binary\n"
1764    "                load SMBIOS entry from binary file\n"
1765    "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1766    "              [,uefi=on|off]\n"
1767    "                specify SMBIOS type 0 fields\n"
1768    "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1769    "              [,uuid=uuid][,sku=str][,family=str]\n"
1770    "                specify SMBIOS type 1 fields\n"
1771    "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1772    "              [,asset=str][,location=str]\n"
1773    "                specify SMBIOS type 2 fields\n"
1774    "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1775    "              [,sku=str]\n"
1776    "                specify SMBIOS type 3 fields\n"
1777    "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1778    "              [,asset=str][,part=str]\n"
1779    "                specify SMBIOS type 4 fields\n"
1780    "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1781    "               [,asset=str][,part=str][,speed=%d]\n"
1782    "                specify SMBIOS type 17 fields\n",
1783    QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1784STEXI
1785@item -smbios file=@var{binary}
1786@findex -smbios
1787Load SMBIOS entry from binary file.
1788
1789@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1790Specify SMBIOS type 0 fields
1791
1792@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}]
1793Specify SMBIOS type 1 fields
1794
1795@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}]
1796Specify SMBIOS type 2 fields
1797
1798@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1799Specify SMBIOS type 3 fields
1800
1801@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1802Specify SMBIOS type 4 fields
1803
1804@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}]
1805Specify SMBIOS type 17 fields
1806ETEXI
1807
1808STEXI
1809@end table
1810ETEXI
1811DEFHEADING()
1812
1813DEFHEADING(Network options:)
1814STEXI
1815@table @option
1816ETEXI
1817
1818DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1819#ifdef CONFIG_SLIRP
1820    "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1821    "         [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1822    "         [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1823    "         [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
1824    "         [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1825#ifndef _WIN32
1826                                             "[,smb=dir[,smbserver=addr]]\n"
1827#endif
1828    "                configure a user mode network backend with ID 'str',\n"
1829    "                its DHCP server and optional services\n"
1830#endif
1831#ifdef _WIN32
1832    "-netdev tap,id=str,ifname=name\n"
1833    "                configure a host TAP network backend with ID 'str'\n"
1834#else
1835    "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1836    "         [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1837    "         [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1838    "         [,poll-us=n]\n"
1839    "                configure a host TAP network backend with ID 'str'\n"
1840    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1841    "                use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1842    "                to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1843    "                to deconfigure it\n"
1844    "                use '[down]script=no' to disable script execution\n"
1845    "                use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1846    "                configure it\n"
1847    "                use 'fd=h' to connect to an already opened TAP interface\n"
1848    "                use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1849    "                use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1850    "                default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1851    "                use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1852    "                use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1853    "                use vhost=on to enable experimental in kernel accelerator\n"
1854    "                    (only has effect for virtio guests which use MSIX)\n"
1855    "                use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1856    "                use 'vhostfd=h' to connect to an already opened vhost net device\n"
1857    "                use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1858    "                use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1859    "                use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1860    "                spent on busy polling for vhost net\n"
1861    "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1862    "                configure a host TAP network backend with ID 'str' that is\n"
1863    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1864    "                using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1865#endif
1866#ifdef __linux__
1867    "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1868    "         [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1869    "         [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1870    "         [,rxcookie=rxcookie][,offset=offset]\n"
1871    "                configure a network backend with ID 'str' connected to\n"
1872    "                an Ethernet over L2TPv3 pseudowire.\n"
1873    "                Linux kernel 3.3+ as well as most routers can talk\n"
1874    "                L2TPv3. This transport allows connecting a VM to a VM,\n"
1875    "                VM to a router and even VM to Host. It is a nearly-universal\n"
1876    "                standard (RFC3391). Note - this implementation uses static\n"
1877    "                pre-configured tunnels (same as the Linux kernel).\n"
1878    "                use 'src=' to specify source address\n"
1879    "                use 'dst=' to specify destination address\n"
1880    "                use 'udp=on' to specify udp encapsulation\n"
1881    "                use 'srcport=' to specify source udp port\n"
1882    "                use 'dstport=' to specify destination udp port\n"
1883    "                use 'ipv6=on' to force v6\n"
1884    "                L2TPv3 uses cookies to prevent misconfiguration as\n"
1885    "                well as a weak security measure\n"
1886    "                use 'rxcookie=0x012345678' to specify a rxcookie\n"
1887    "                use 'txcookie=0x012345678' to specify a txcookie\n"
1888    "                use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1889    "                use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1890    "                use 'pincounter=on' to work around broken counter handling in peer\n"
1891    "                use 'offset=X' to add an extra offset between header and data\n"
1892#endif
1893    "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1894    "                configure a network backend to connect to another network\n"
1895    "                using a socket connection\n"
1896    "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1897    "                configure a network backend to connect to a multicast maddr and port\n"
1898    "                use 'localaddr=addr' to specify the host address to send packets from\n"
1899    "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1900    "                configure a network backend to connect to another network\n"
1901    "                using an UDP tunnel\n"
1902#ifdef CONFIG_VDE
1903    "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1904    "                configure a network backend to connect to port 'n' of a vde switch\n"
1905    "                running on host and listening for incoming connections on 'socketpath'.\n"
1906    "                Use group 'groupname' and mode 'octalmode' to change default\n"
1907    "                ownership and permissions for communication port.\n"
1908#endif
1909#ifdef CONFIG_NETMAP
1910    "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1911    "                attach to the existing netmap-enabled network interface 'name', or to a\n"
1912    "                VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1913    "                netmap device, defaults to '/dev/netmap')\n"
1914#endif
1915#ifdef CONFIG_POSIX
1916    "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1917    "                configure a vhost-user network, backed by a chardev 'dev'\n"
1918#endif
1919    "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
1920    "                configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
1921DEF("nic", HAS_ARG, QEMU_OPTION_nic,
1922    "-nic [tap|bridge|"
1923#ifdef CONFIG_SLIRP
1924    "user|"
1925#endif
1926#ifdef __linux__
1927    "l2tpv3|"
1928#endif
1929#ifdef CONFIG_VDE
1930    "vde|"
1931#endif
1932#ifdef CONFIG_NETMAP
1933    "netmap|"
1934#endif
1935#ifdef CONFIG_POSIX
1936    "vhost-user|"
1937#endif
1938    "socket][,option][,...][mac=macaddr]\n"
1939    "                initialize an on-board / default host NIC (using MAC address\n"
1940    "                macaddr) and connect it to the given host network backend\n"
1941    "-nic none       use it alone to have zero network devices (the default is to\n"
1942    "                provided a 'user' network connection)\n",
1943    QEMU_ARCH_ALL)
1944DEF("net", HAS_ARG, QEMU_OPTION_net,
1945    "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1946    "                configure or create an on-board (or machine default) NIC and\n"
1947    "                connect it to hub 0 (please use -nic unless you need a hub)\n"
1948    "-net ["
1949#ifdef CONFIG_SLIRP
1950    "user|"
1951#endif
1952    "tap|"
1953    "bridge|"
1954#ifdef CONFIG_VDE
1955    "vde|"
1956#endif
1957#ifdef CONFIG_NETMAP
1958    "netmap|"
1959#endif
1960    "socket][,option][,option][,...]\n"
1961    "                old way to initialize a host network interface\n"
1962    "                (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
1963STEXI
1964@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]
1965@findex -nic
1966This option is a shortcut for configuring both the on-board (default) guest
1967NIC hardware and the host network backend in one go. The host backend options
1968are the same as with the corresponding @option{-netdev} options below.
1969The guest NIC model can be set with @option{model=@var{modelname}}.
1970Use @option{model=help} to list the available device types.
1971The hardware MAC address can be set with @option{mac=@var{macaddr}}.
1972
1973The following two example do exactly the same, to show how @option{-nic} can
1974be used to shorten the command line length (note that the e1000 is the default
1975on i386, so the @option{model=e1000} parameter could even be omitted here, too):
1976@example
1977qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
1978qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
1979@end example
1980
1981@item -nic none
1982Indicate that no network devices should be configured. It is used to override
1983the default configuration (default NIC with ``user'' host network backend)
1984which is activated if no other networking options are provided.
1985
1986@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1987@findex -netdev
1988Configure user mode host network backend which requires no administrator
1989privilege to run. Valid options are:
1990
1991@table @option
1992@item id=@var{id}
1993Assign symbolic name for use in monitor commands.
1994
1995@item ipv4=on|off and ipv6=on|off
1996Specify that either IPv4 or IPv6 must be enabled. If neither is specified
1997both protocols are enabled.
1998
1999@item net=@var{addr}[/@var{mask}]
2000Set IP network address the guest will see. Optionally specify the netmask,
2001either in the form a.b.c.d or as number of valid top-most bits. Default is
200210.0.2.0/24.
2003
2004@item host=@var{addr}
2005Specify the guest-visible address of the host. Default is the 2nd IP in the
2006guest network, i.e. x.x.x.2.
2007
2008@item ipv6-net=@var{addr}[/@var{int}]
2009Set IPv6 network address the guest will see (default is fec0::/64). The
2010network prefix is given in the usual hexadecimal IPv6 address
2011notation. The prefix size is optional, and is given as the number of
2012valid top-most bits (default is 64).
2013
2014@item ipv6-host=@var{addr}
2015Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2016the guest network, i.e. xxxx::2.
2017
2018@item restrict=on|off
2019If this option is enabled, the guest will be isolated, i.e. it will not be
2020able to contact the host and no guest IP packets will be routed over the host
2021to the outside. This option does not affect any explicitly set forwarding rules.
2022
2023@item hostname=@var{name}
2024Specifies the client hostname reported by the built-in DHCP server.
2025
2026@item dhcpstart=@var{addr}
2027Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2028is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2029
2030@item dns=@var{addr}
2031Specify the guest-visible address of the virtual nameserver. The address must
2032be different from the host address. Default is the 3rd IP in the guest network,
2033i.e. x.x.x.3.
2034
2035@item ipv6-dns=@var{addr}
2036Specify the guest-visible address of the IPv6 virtual nameserver. The address
2037must be different from the host address. Default is the 3rd IP in the guest
2038network, i.e. xxxx::3.
2039
2040@item dnssearch=@var{domain}
2041Provides an entry for the domain-search list sent by the built-in
2042DHCP server. More than one domain suffix can be transmitted by specifying
2043this option multiple times. If supported, this will cause the guest to
2044automatically try to append the given domain suffix(es) in case a domain name
2045can not be resolved.
2046
2047Example:
2048@example
2049qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2050@end example
2051
2052@item domainname=@var{domain}
2053Specifies the client domain name reported by the built-in DHCP server.
2054
2055@item tftp=@var{dir}
2056When using the user mode network stack, activate a built-in TFTP
2057server. The files in @var{dir} will be exposed as the root of a TFTP server.
2058The TFTP client on the guest must be configured in binary mode (use the command
2059@code{bin} of the Unix TFTP client).
2060
2061@item tftp-server-name=@var{name}
2062In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option
206366). This can be used to advise the guest to load boot files or configurations
2064from a different server than the host address.
2065
2066@item bootfile=@var{file}
2067When using the user mode network stack, broadcast @var{file} as the BOOTP
2068filename. In conjunction with @option{tftp}, this can be used to network boot
2069a guest from a local directory.
2070
2071Example (using pxelinux):
2072@example
2073qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2074    -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2075@end example
2076
2077@item smb=@var{dir}[,smbserver=@var{addr}]
2078When using the user mode network stack, activate a built-in SMB
2079server so that Windows OSes can access to the host files in @file{@var{dir}}
2080transparently. The IP address of the SMB server can be set to @var{addr}. By
2081default the 4th IP in the guest network is used, i.e. x.x.x.4.
2082
2083In the guest Windows OS, the line:
2084@example
208510.0.2.4 smbserver
2086@end example
2087must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2088or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2089
2090Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2091
2092Note that a SAMBA server must be installed on the host OS.
2093
2094@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2095Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2096the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2097@var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2098given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2099be bound to a specific host interface. If no connection type is set, TCP is
2100used. This option can be given multiple times.
2101
2102For example, to redirect host X11 connection from screen 1 to guest
2103screen 0, use the following:
2104
2105@example
2106# on the host
2107qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2108# this host xterm should open in the guest X11 server
2109xterm -display :1
2110@end example
2111
2112To redirect telnet connections from host port 5555 to telnet port on
2113the guest, use the following:
2114
2115@example
2116# on the host
2117qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2118telnet localhost 5555
2119@end example
2120
2121Then when you use on the host @code{telnet localhost 5555}, you
2122connect to the guest telnet server.
2123
2124@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2125@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2126Forward guest TCP connections to the IP address @var{server} on port @var{port}
2127to the character device @var{dev} or to a program executed by @var{cmd:command}
2128which gets spawned for each connection. This option can be given multiple times.
2129
2130You can either use a chardev directly and have that one used throughout QEMU's
2131lifetime, like in the following example:
2132
2133@example
2134# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2135# the guest accesses it
2136qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
2137@end example
2138
2139Or you can execute a command on every TCP connection established by the guest,
2140so that QEMU behaves similar to an inetd process for that virtual server:
2141
2142@example
2143# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2144# and connect the TCP stream to its stdin/stdout
2145qemu-system-i386 -nic  'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2146@end example
2147
2148@end table
2149
2150@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2151Configure a host TAP network backend with ID @var{id}.
2152
2153Use the network script @var{file} to configure it and the network script
2154@var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2155automatically provides one. The default network configure script is
2156@file{/etc/qemu-ifup} and the default network deconfigure script is
2157@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2158to disable script execution.
2159
2160If running QEMU as an unprivileged user, use the network helper
2161@var{helper} to configure the TAP interface and attach it to the bridge.
2162The default network helper executable is @file{/path/to/qemu-bridge-helper}
2163and the default bridge device is @file{br0}.
2164
2165@option{fd}=@var{h} can be used to specify the handle of an already
2166opened host TAP interface.
2167
2168Examples:
2169
2170@example
2171#launch a QEMU instance with the default network script
2172qemu-system-i386 linux.img -nic tap
2173@end example
2174
2175@example
2176#launch a QEMU instance with two NICs, each one connected
2177#to a TAP device
2178qemu-system-i386 linux.img \
2179        -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2180        -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2181@end example
2182
2183@example
2184#launch a QEMU instance with the default network helper to
2185#connect a TAP device to bridge br0
2186qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \
2187        -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
2188@end example
2189
2190@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2191Connect a host TAP network interface to a host bridge device.
2192
2193Use the network helper @var{helper} to configure the TAP interface and
2194attach it to the bridge. The default network helper executable is
2195@file{/path/to/qemu-bridge-helper} and the default bridge
2196device is @file{br0}.
2197
2198Examples:
2199
2200@example
2201#launch a QEMU instance with the default network helper to
2202#connect a TAP device to bridge br0
2203qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
2204@end example
2205
2206@example
2207#launch a QEMU instance with the default network helper to
2208#connect a TAP device to bridge qemubr0
2209qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
2210@end example
2211
2212@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2213
2214This host network backend can be used to connect the guest's network to
2215another QEMU virtual machine using a TCP socket connection. If @option{listen}
2216is specified, QEMU waits for incoming connections on @var{port}
2217(@var{host} is optional). @option{connect} is used to connect to
2218another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2219specifies an already opened TCP socket.
2220
2221Example:
2222@example
2223# launch a first QEMU instance
2224qemu-system-i386 linux.img \
2225                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2226                 -netdev socket,id=n1,listen=:1234
2227# connect the network of this instance to the network of the first instance
2228qemu-system-i386 linux.img \
2229                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2230                 -netdev socket,id=n2,connect=127.0.0.1:1234
2231@end example
2232
2233@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2234
2235Configure a socket host network backend to share the guest's network traffic
2236with another QEMU virtual machines using a UDP multicast socket, effectively
2237making a bus for every QEMU with same multicast address @var{maddr} and @var{port}.
2238NOTES:
2239@enumerate
2240@item
2241Several QEMU can be running on different hosts and share same bus (assuming
2242correct multicast setup for these hosts).
2243@item
2244mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2245@url{http://user-mode-linux.sf.net}.
2246@item
2247Use @option{fd=h} to specify an already opened UDP multicast socket.
2248@end enumerate
2249
2250Example:
2251@example
2252# launch one QEMU instance
2253qemu-system-i386 linux.img \
2254                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2255                 -netdev socket,id=n1,mcast=230.0.0.1:1234
2256# launch another QEMU instance on same "bus"
2257qemu-system-i386 linux.img \
2258                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2259                 -netdev socket,id=n2,mcast=230.0.0.1:1234
2260# launch yet another QEMU instance on same "bus"
2261qemu-system-i386 linux.img \
2262                 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \
2263                 -netdev socket,id=n3,mcast=230.0.0.1:1234
2264@end example
2265
2266Example (User Mode Linux compat.):
2267@example
2268# launch QEMU instance (note mcast address selected is UML's default)
2269qemu-system-i386 linux.img \
2270                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2271                 -netdev socket,id=n1,mcast=239.192.168.1:1102
2272# launch UML
2273/path/to/linux ubd0=/path/to/root_fs eth0=mcast
2274@end example
2275
2276Example (send packets from host's 1.2.3.4):
2277@example
2278qemu-system-i386 linux.img \
2279                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2280                 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2281@end example
2282
2283@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}]
2284Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a
2285popular protocol to transport Ethernet (and other Layer 2) data frames between
2286two systems. It is present in routers, firewalls and the Linux kernel
2287(from version 3.3 onwards).
2288
2289This transport allows a VM to communicate to another VM, router or firewall directly.
2290
2291@table @option
2292@item src=@var{srcaddr}
2293    source address (mandatory)
2294@item dst=@var{dstaddr}
2295    destination address (mandatory)
2296@item udp
2297    select udp encapsulation (default is ip).
2298@item srcport=@var{srcport}
2299    source udp port.
2300@item dstport=@var{dstport}
2301    destination udp port.
2302@item ipv6
2303    force v6, otherwise defaults to v4.
2304@item rxcookie=@var{rxcookie}
2305@itemx txcookie=@var{txcookie}
2306    Cookies are a weak form of security in the l2tpv3 specification.
2307Their function is mostly to prevent misconfiguration. By default they are 32
2308bit.
2309@item cookie64
2310    Set cookie size to 64 bit instead of the default 32
2311@item counter=off
2312    Force a 'cut-down' L2TPv3 with no counter as in
2313draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2314@item pincounter=on
2315    Work around broken counter handling in peer. This may also help on
2316networks which have packet reorder.
2317@item offset=@var{offset}
2318    Add an extra offset between header and data
2319@end table
2320
2321For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2322on the remote Linux host 1.2.3.4:
2323@example
2324# Setup tunnel on linux host using raw ip as encapsulation
2325# on 1.2.3.4
2326ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2327    encap udp udp_sport 16384 udp_dport 16384
2328ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2329    0xFFFFFFFF peer_session_id 0xFFFFFFFF
2330ifconfig vmtunnel0 mtu 1500
2331ifconfig vmtunnel0 up
2332brctl addif br-lan vmtunnel0
2333
2334
2335# on 4.3.2.1
2336# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2337
2338qemu-system-i386 linux.img -device e1000,netdev=n1 \
2339    -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2340
2341@end example
2342
2343@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2344Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and
2345listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2346and MODE @var{octalmode} to change default ownership and permissions for
2347communication port. This option is only available if QEMU has been compiled
2348with vde support enabled.
2349
2350Example:
2351@example
2352# launch vde switch
2353vde_switch -F -sock /tmp/myswitch
2354# launch QEMU instance
2355qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch
2356@end example
2357
2358@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2359
2360Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2361be a unix domain socket backed one. The vhost-user uses a specifically defined
2362protocol to pass vhost ioctl replacement messages to an application on the other
2363end of the socket. On non-MSIX guests, the feature can be forced with
2364@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2365be created for multiqueue vhost-user.
2366
2367Example:
2368@example
2369qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2370     -numa node,memdev=mem \
2371     -chardev socket,id=chr0,path=/path/to/socket \
2372     -netdev type=vhost-user,id=net0,chardev=chr0 \
2373     -device virtio-net-pci,netdev=net0
2374@end example
2375
2376@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2377
2378Create a hub port on the emulated hub with ID @var{hubid}.
2379
2380The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2381single netdev. Alternatively, you can also connect the hubport to another
2382netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option.
2383
2384@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2385@findex -net
2386Legacy option to configure or create an on-board (or machine default) Network
2387Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e.
2388the default hub), or to the netdev @var{nd}.
2389The NIC is an e1000 by default on the PC target. Optionally, the MAC address
2390can be changed to @var{mac}, the device address set to @var{addr} (PCI cards
2391only), and a @var{name} can be assigned for use in monitor commands.
2392Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2393that the card should have; this option currently only affects virtio cards; set
2394@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2395NIC is created.  QEMU can emulate several different models of network card.
2396Use @code{-net nic,model=help} for a list of available devices for your target.
2397
2398@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}]
2399Configure a host network backend (with the options corresponding to the same
2400@option{-netdev} option) and connect it to the emulated hub 0 (the default
2401hub). Use @var{name} to specify the name of the hub port.
2402ETEXI
2403
2404STEXI
2405@end table
2406ETEXI
2407DEFHEADING()
2408
2409DEFHEADING(Character device options:)
2410
2411DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2412    "-chardev help\n"
2413    "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2414    "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2415    "         [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n"
2416    "         [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2417    "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n"
2418    "         [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2419    "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2420    "         [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2421    "         [,logfile=PATH][,logappend=on|off]\n"
2422    "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2423    "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2424    "         [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2425    "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2426    "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2427    "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2428#ifdef _WIN32
2429    "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2430    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2431#else
2432    "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2433    "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2434#endif
2435#ifdef CONFIG_BRLAPI
2436    "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2437#endif
2438#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2439        || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2440    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2441    "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2442#endif
2443#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2444    "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2445    "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2446#endif
2447#if defined(CONFIG_SPICE)
2448    "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2449    "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2450#endif
2451    , QEMU_ARCH_ALL
2452)
2453
2454STEXI
2455
2456The general form of a character device option is:
2457@table @option
2458@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2459@findex -chardev
2460Backend is one of:
2461@option{null},
2462@option{socket},
2463@option{udp},
2464@option{msmouse},
2465@option{vc},
2466@option{ringbuf},
2467@option{file},
2468@option{pipe},
2469@option{console},
2470@option{serial},
2471@option{pty},
2472@option{stdio},
2473@option{braille},
2474@option{tty},
2475@option{parallel},
2476@option{parport},
2477@option{spicevmc},
2478@option{spiceport}.
2479The specific backend will determine the applicable options.
2480
2481Use @code{-chardev help} to print all available chardev backend types.
2482
2483All devices must have an id, which can be any string up to 127 characters long.
2484It is used to uniquely identify this device in other command line directives.
2485
2486A character device may be used in multiplexing mode by multiple front-ends.
2487Specify @option{mux=on} to enable this mode.
2488A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2489backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2490If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2491create a multiplexer with your specified ID, and you can then configure multiple
2492front ends to use that chardev ID for their input/output. Up to four different
2493front ends can be connected to a single multiplexed chardev. (Without
2494multiplexing enabled, a chardev can only be used by a single front end.)
2495For instance you could use this to allow a single stdio chardev to be used by
2496two serial ports and the QEMU monitor:
2497
2498@example
2499-chardev stdio,mux=on,id=char0 \
2500-mon chardev=char0,mode=readline \
2501-serial chardev:char0 \
2502-serial chardev:char0
2503@end example
2504
2505You can have more than one multiplexer in a system configuration; for instance
2506you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2507multiplexed between the QEMU monitor and a parallel port:
2508
2509@example
2510-chardev stdio,mux=on,id=char0 \
2511-mon chardev=char0,mode=readline \
2512-parallel chardev:char0 \
2513-chardev tcp,...,mux=on,id=char1 \
2514-serial chardev:char1 \
2515-serial chardev:char1
2516@end example
2517
2518When you're using a multiplexed character device, some escape sequences are
2519interpreted in the input. @xref{mux_keys, Keys in the character backend
2520multiplexer}.
2521
2522Note that some other command line options may implicitly create multiplexed
2523character backends; for instance @option{-serial mon:stdio} creates a
2524multiplexed stdio backend connected to the serial port and the QEMU monitor,
2525and @option{-nographic} also multiplexes the console and the monitor to
2526stdio.
2527
2528There is currently no support for multiplexing in the other direction
2529(where a single QEMU front end takes input and output from multiple chardevs).
2530
2531Every backend supports the @option{logfile} option, which supplies the path
2532to a file to record all data transmitted via the backend. The @option{logappend}
2533option controls whether the log file will be truncated or appended to when
2534opened.
2535
2536@end table
2537
2538The available backends are:
2539
2540@table @option
2541@item -chardev null,id=@var{id}
2542A void device. This device will not emit any data, and will drop any data it
2543receives. The null backend does not take any options.
2544
2545@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,websocket][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2546
2547Create a two-way stream socket, which can be either a TCP or a unix socket. A
2548unix socket will be created if @option{path} is specified. Behaviour is
2549undefined if TCP options are specified for a unix socket.
2550
2551@option{server} specifies that the socket shall be a listening socket.
2552
2553@option{nowait} specifies that QEMU should not block waiting for a client to
2554connect to a listening socket.
2555
2556@option{telnet} specifies that traffic on the socket should interpret telnet
2557escape sequences.
2558
2559@option{websocket} specifies that the socket uses WebSocket protocol for
2560communication.
2561
2562@option{reconnect} sets the timeout for reconnecting on non-server sockets when
2563the remote end goes away.  qemu will delay this many seconds and then attempt
2564to reconnect.  Zero disables reconnecting, and is the default.
2565
2566@option{tls-creds} requests enablement of the TLS protocol for encryption,
2567and specifies the id of the TLS credentials to use for the handshake. The
2568credentials must be previously created with the @option{-object tls-creds}
2569argument.
2570
2571TCP and unix socket options are given below:
2572
2573@table @option
2574
2575@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2576
2577@option{host} for a listening socket specifies the local address to be bound.
2578For a connecting socket species the remote host to connect to. @option{host} is
2579optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2580
2581@option{port} for a listening socket specifies the local port to be bound. For a
2582connecting socket specifies the port on the remote host to connect to.
2583@option{port} can be given as either a port number or a service name.
2584@option{port} is required.
2585
2586@option{to} is only relevant to listening sockets. If it is specified, and
2587@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2588to and including @option{to} until it succeeds. @option{to} must be specified
2589as a port number.
2590
2591@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2592If neither is specified the socket may use either protocol.
2593
2594@option{nodelay} disables the Nagle algorithm.
2595
2596@item unix options: path=@var{path}
2597
2598@option{path} specifies the local path of the unix socket. @option{path} is
2599required.
2600
2601@end table
2602
2603@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2604
2605Sends all traffic from the guest to a remote host over UDP.
2606
2607@option{host} specifies the remote host to connect to. If not specified it
2608defaults to @code{localhost}.
2609
2610@option{port} specifies the port on the remote host to connect to. @option{port}
2611is required.
2612
2613@option{localaddr} specifies the local address to bind to. If not specified it
2614defaults to @code{0.0.0.0}.
2615
2616@option{localport} specifies the local port to bind to. If not specified any
2617available local port will be used.
2618
2619@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2620If neither is specified the device may use either protocol.
2621
2622@item -chardev msmouse,id=@var{id}
2623
2624Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2625take any options.
2626
2627@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2628
2629Connect to a QEMU text console. @option{vc} may optionally be given a specific
2630size.
2631
2632@option{width} and @option{height} specify the width and height respectively of
2633the console, in pixels.
2634
2635@option{cols} and @option{rows} specify that the console be sized to fit a text
2636console with the given dimensions.
2637
2638@item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2639
2640Create a ring buffer with fixed size @option{size}.
2641@var{size} must be a power of two and defaults to @code{64K}.
2642
2643@item -chardev file,id=@var{id},path=@var{path}
2644
2645Log all traffic received from the guest to a file.
2646
2647@option{path} specifies the path of the file to be opened. This file will be
2648created if it does not already exist, and overwritten if it does. @option{path}
2649is required.
2650
2651@item -chardev pipe,id=@var{id},path=@var{path}
2652
2653Create a two-way connection to the guest. The behaviour differs slightly between
2654Windows hosts and other hosts:
2655
2656On Windows, a single duplex pipe will be created at
2657@file{\\.pipe\@option{path}}.
2658
2659On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2660@file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2661received by the guest. Data written by the guest can be read from
2662@file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2663be present.
2664
2665@option{path} forms part of the pipe path as described above. @option{path} is
2666required.
2667
2668@item -chardev console,id=@var{id}
2669
2670Send traffic from the guest to QEMU's standard output. @option{console} does not
2671take any options.
2672
2673@option{console} is only available on Windows hosts.
2674
2675@item -chardev serial,id=@var{id},path=@option{path}
2676
2677Send traffic from the guest to a serial device on the host.
2678
2679On Unix hosts serial will actually accept any tty device,
2680not only serial lines.
2681
2682@option{path} specifies the name of the serial device to open.
2683
2684@item -chardev pty,id=@var{id}
2685
2686Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2687not take any options.
2688
2689@option{pty} is not available on Windows hosts.
2690
2691@item -chardev stdio,id=@var{id}[,signal=on|off]
2692Connect to standard input and standard output of the QEMU process.
2693
2694@option{signal} controls if signals are enabled on the terminal, that includes
2695exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2696default, use @option{signal=off} to disable it.
2697
2698@item -chardev braille,id=@var{id}
2699
2700Connect to a local BrlAPI server. @option{braille} does not take any options.
2701
2702@item -chardev tty,id=@var{id},path=@var{path}
2703
2704@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2705DragonFlyBSD hosts.  It is an alias for @option{serial}.
2706
2707@option{path} specifies the path to the tty. @option{path} is required.
2708
2709@item -chardev parallel,id=@var{id},path=@var{path}
2710@itemx -chardev parport,id=@var{id},path=@var{path}
2711
2712@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2713
2714Connect to a local parallel port.
2715
2716@option{path} specifies the path to the parallel port device. @option{path} is
2717required.
2718
2719@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2720
2721@option{spicevmc} is only available when spice support is built in.
2722
2723@option{debug} debug level for spicevmc
2724
2725@option{name} name of spice channel to connect to
2726
2727Connect to a spice virtual machine channel, such as vdiport.
2728
2729@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2730
2731@option{spiceport} is only available when spice support is built in.
2732
2733@option{debug} debug level for spicevmc
2734
2735@option{name} name of spice port to connect to
2736
2737Connect to a spice port, allowing a Spice client to handle the traffic
2738identified by a name (preferably a fqdn).
2739ETEXI
2740
2741STEXI
2742@end table
2743ETEXI
2744DEFHEADING()
2745
2746DEFHEADING(Bluetooth(R) options:)
2747STEXI
2748@table @option
2749ETEXI
2750
2751DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2752    "-bt hci,null    dumb bluetooth HCI - doesn't respond to commands\n" \
2753    "-bt hci,host[:id]\n" \
2754    "                use host's HCI with the given name\n" \
2755    "-bt hci[,vlan=n]\n" \
2756    "                emulate a standard HCI in virtual scatternet 'n'\n" \
2757    "-bt vhci[,vlan=n]\n" \
2758    "                add host computer to virtual scatternet 'n' using VHCI\n" \
2759    "-bt device:dev[,vlan=n]\n" \
2760    "                emulate a bluetooth device 'dev' in scatternet 'n'\n",
2761    QEMU_ARCH_ALL)
2762STEXI
2763@item -bt hci[...]
2764@findex -bt
2765Defines the function of the corresponding Bluetooth HCI.  -bt options
2766are matched with the HCIs present in the chosen machine type.  For
2767example when emulating a machine with only one HCI built into it, only
2768the first @code{-bt hci[...]} option is valid and defines the HCI's
2769logic.  The Transport Layer is decided by the machine type.  Currently
2770the machines @code{n800} and @code{n810} have one HCI and all other
2771machines have none.
2772
2773Note: This option and the whole bluetooth subsystem is considered as deprecated.
2774If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where
2775you describe your usecase.
2776
2777@anchor{bt-hcis}
2778The following three types are recognized:
2779
2780@table @option
2781@item -bt hci,null
2782(default) The corresponding Bluetooth HCI assumes no internal logic
2783and will not respond to any HCI commands or emit events.
2784
2785@item -bt hci,host[:@var{id}]
2786(@code{bluez} only) The corresponding HCI passes commands / events
2787to / from the physical HCI identified by the name @var{id} (default:
2788@code{hci0}) on the computer running QEMU.  Only available on @code{bluez}
2789capable systems like Linux.
2790
2791@item -bt hci[,vlan=@var{n}]
2792Add a virtual, standard HCI that will participate in the Bluetooth
2793scatternet @var{n} (default @code{0}).  Similarly to @option{-net}
2794VLANs, devices inside a bluetooth network @var{n} can only communicate
2795with other devices in the same network (scatternet).
2796@end table
2797
2798@item -bt vhci[,vlan=@var{n}]
2799(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2800to the host bluetooth stack instead of to the emulated target.  This
2801allows the host and target machines to participate in a common scatternet
2802and communicate.  Requires the Linux @code{vhci} driver installed.  Can
2803be used as following:
2804
2805@example
2806qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2807@end example
2808
2809@item -bt device:@var{dev}[,vlan=@var{n}]
2810Emulate a bluetooth device @var{dev} and place it in network @var{n}
2811(default @code{0}).  QEMU can only emulate one type of bluetooth devices
2812currently:
2813
2814@table @option
2815@item keyboard
2816Virtual wireless keyboard implementing the HIDP bluetooth profile.
2817@end table
2818ETEXI
2819
2820STEXI
2821@end table
2822ETEXI
2823DEFHEADING()
2824
2825#ifdef CONFIG_TPM
2826DEFHEADING(TPM device options:)
2827
2828DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2829    "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2830    "                use path to provide path to a character device; default is /dev/tpm0\n"
2831    "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2832    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2833    "-tpmdev emulator,id=id,chardev=dev\n"
2834    "                configure the TPM device using chardev backend\n",
2835    QEMU_ARCH_ALL)
2836STEXI
2837
2838The general form of a TPM device option is:
2839@table @option
2840
2841@item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2842@findex -tpmdev
2843
2844The specific backend type will determine the applicable options.
2845The @code{-tpmdev} option creates the TPM backend and requires a
2846@code{-device} option that specifies the TPM frontend interface model.
2847
2848Use @code{-tpmdev help} to print all available TPM backend types.
2849
2850@end table
2851
2852The available backends are:
2853
2854@table @option
2855
2856@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2857
2858(Linux-host only) Enable access to the host's TPM using the passthrough
2859driver.
2860
2861@option{path} specifies the path to the host's TPM device, i.e., on
2862a Linux host this would be @code{/dev/tpm0}.
2863@option{path} is optional and by default @code{/dev/tpm0} is used.
2864
2865@option{cancel-path} specifies the path to the host TPM device's sysfs
2866entry allowing for cancellation of an ongoing TPM command.
2867@option{cancel-path} is optional and by default QEMU will search for the
2868sysfs entry to use.
2869
2870Some notes about using the host's TPM with the passthrough driver:
2871
2872The TPM device accessed by the passthrough driver must not be
2873used by any other application on the host.
2874
2875Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2876the VM's firmware (BIOS/UEFI) will not be able to initialize the
2877TPM again and may therefore not show a TPM-specific menu that would
2878otherwise allow the user to configure the TPM, e.g., allow the user to
2879enable/disable or activate/deactivate the TPM.
2880Further, if TPM ownership is released from within a VM then the host's TPM
2881will get disabled and deactivated. To enable and activate the
2882TPM again afterwards, the host has to be rebooted and the user is
2883required to enter the firmware's menu to enable and activate the TPM.
2884If the TPM is left disabled and/or deactivated most TPM commands will fail.
2885
2886To create a passthrough TPM use the following two options:
2887@example
2888-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2889@end example
2890Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2891@code{tpmdev=tpm0} in the device option.
2892
2893@item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2894
2895(Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2896chardev backend.
2897
2898@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2899
2900To create a TPM emulator backend device with chardev socket backend:
2901@example
2902
2903-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2904
2905@end example
2906
2907ETEXI
2908
2909STEXI
2910@end table
2911ETEXI
2912DEFHEADING()
2913
2914#endif
2915
2916DEFHEADING(Linux/Multiboot boot specific:)
2917STEXI
2918
2919When using these options, you can use a given Linux or Multiboot
2920kernel without installing it in the disk image. It can be useful
2921for easier testing of various kernels.
2922
2923@table @option
2924ETEXI
2925
2926DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
2927    "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
2928STEXI
2929@item -kernel @var{bzImage}
2930@findex -kernel
2931Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2932or in multiboot format.
2933ETEXI
2934
2935DEF("append", HAS_ARG, QEMU_OPTION_append, \
2936    "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
2937STEXI
2938@item -append @var{cmdline}
2939@findex -append
2940Use @var{cmdline} as kernel command line
2941ETEXI
2942
2943DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
2944           "-initrd file    use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
2945STEXI
2946@item -initrd @var{file}
2947@findex -initrd
2948Use @var{file} as initial ram disk.
2949
2950@item -initrd "@var{file1} arg=foo,@var{file2}"
2951
2952This syntax is only available with multiboot.
2953
2954Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2955first module.
2956ETEXI
2957
2958DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
2959    "-dtb    file    use 'file' as device tree image\n", QEMU_ARCH_ALL)
2960STEXI
2961@item -dtb @var{file}
2962@findex -dtb
2963Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2964on boot.
2965ETEXI
2966
2967STEXI
2968@end table
2969ETEXI
2970DEFHEADING()
2971
2972DEFHEADING(Debug/Expert options:)
2973STEXI
2974@table @option
2975ETEXI
2976
2977DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
2978    "-fw_cfg [name=]<name>,file=<file>\n"
2979    "                add named fw_cfg entry with contents from file\n"
2980    "-fw_cfg [name=]<name>,string=<str>\n"
2981    "                add named fw_cfg entry with contents from string\n",
2982    QEMU_ARCH_ALL)
2983STEXI
2984
2985@item -fw_cfg [name=]@var{name},file=@var{file}
2986@findex -fw_cfg
2987Add named fw_cfg entry with contents from file @var{file}.
2988
2989@item -fw_cfg [name=]@var{name},string=@var{str}
2990Add named fw_cfg entry with contents from string @var{str}.
2991
2992The terminating NUL character of the contents of @var{str} will not be
2993included as part of the fw_cfg item data. To insert contents with
2994embedded NUL characters, you have to use the @var{file} parameter.
2995
2996The fw_cfg entries are passed by QEMU through to the guest.
2997
2998Example:
2999@example
3000    -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3001@end example
3002creates an fw_cfg entry named opt/com.mycompany/blob with contents
3003from ./my_blob.bin.
3004
3005ETEXI
3006
3007DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3008    "-serial dev     redirect the serial port to char device 'dev'\n",
3009    QEMU_ARCH_ALL)
3010STEXI
3011@item -serial @var{dev}
3012@findex -serial
3013Redirect the virtual serial port to host character device
3014@var{dev}. The default device is @code{vc} in graphical mode and
3015@code{stdio} in non graphical mode.
3016
3017This option can be used several times to simulate up to 4 serial
3018ports.
3019
3020Use @code{-serial none} to disable all serial ports.
3021
3022Available character devices are:
3023@table @option
3024@item vc[:@var{W}x@var{H}]
3025Virtual console. Optionally, a width and height can be given in pixel with
3026@example
3027vc:800x600
3028@end example
3029It is also possible to specify width or height in characters:
3030@example
3031vc:80Cx24C
3032@end example
3033@item pty
3034[Linux only] Pseudo TTY (a new PTY is automatically allocated)
3035@item none
3036No device is allocated.
3037@item null
3038void device
3039@item chardev:@var{id}
3040Use a named character device defined with the @code{-chardev} option.
3041@item /dev/XXX
3042[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3043parameters are set according to the emulated ones.
3044@item /dev/parport@var{N}
3045[Linux only, parallel port only] Use host parallel port
3046@var{N}. Currently SPP and EPP parallel port features can be used.
3047@item file:@var{filename}
3048Write output to @var{filename}. No character can be read.
3049@item stdio
3050[Unix only] standard input/output
3051@item pipe:@var{filename}
3052name pipe @var{filename}
3053@item COM@var{n}
3054[Windows only] Use host serial port @var{n}
3055@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3056This implements UDP Net Console.
3057When @var{remote_host} or @var{src_ip} are not specified
3058they default to @code{0.0.0.0}.
3059When not using a specified @var{src_port} a random port is automatically chosen.
3060
3061If you just want a simple readonly console you can use @code{netcat} or
3062@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3063@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3064will appear in the netconsole session.
3065
3066If you plan to send characters back via netconsole or you want to stop
3067and start QEMU a lot of times, you should have QEMU use the same
3068source port each time by using something like @code{-serial
3069udp::4555@@:4556} to QEMU. Another approach is to use a patched
3070version of netcat which can listen to a TCP port and send and receive
3071characters via udp.  If you have a patched version of netcat which
3072activates telnet remote echo and single char transfer, then you can
3073use the following options to set up a netcat redirector to allow
3074telnet on port 5555 to access the QEMU port.
3075@table @code
3076@item QEMU Options:
3077-serial udp::4555@@:4556
3078@item netcat options:
3079-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3080@item telnet options:
3081localhost 5555
3082@end table
3083
3084@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3085The TCP Net Console has two modes of operation.  It can send the serial
3086I/O to a location or wait for a connection from a location.  By default
3087the TCP Net Console is sent to @var{host} at the @var{port}.  If you use
3088the @var{server} option QEMU will wait for a client socket application
3089to connect to the port before continuing, unless the @code{nowait}
3090option was specified.  The @code{nodelay} option disables the Nagle buffering
3091algorithm.  The @code{reconnect} option only applies if @var{noserver} is
3092set, if the connection goes down it will attempt to reconnect at the
3093given interval.  If @var{host} is omitted, 0.0.0.0 is assumed. Only
3094one TCP connection at a time is accepted. You can use @code{telnet} to
3095connect to the corresponding character device.
3096@table @code
3097@item Example to send tcp console to 192.168.0.2 port 4444
3098-serial tcp:192.168.0.2:4444
3099@item Example to listen and wait on port 4444 for connection
3100-serial tcp::4444,server
3101@item Example to not wait and listen on ip 192.168.0.100 port 4444
3102-serial tcp:192.168.0.100:4444,server,nowait
3103@end table
3104
3105@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3106The telnet protocol is used instead of raw tcp sockets.  The options
3107work the same as if you had specified @code{-serial tcp}.  The
3108difference is that the port acts like a telnet server or client using
3109telnet option negotiation.  This will also allow you to send the
3110MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3111sequence.  Typically in unix telnet you do it with Control-] and then
3112type "send break" followed by pressing the enter key.
3113
3114@item websocket:@var{host}:@var{port},server[,nowait][,nodelay]
3115The WebSocket protocol is used instead of raw tcp socket. The port acts as
3116a WebSocket server. Client mode is not supported.
3117
3118@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3119A unix domain socket is used instead of a tcp socket.  The option works the
3120same as if you had specified @code{-serial tcp} except the unix domain socket
3121@var{path} is used for connections.
3122
3123@item mon:@var{dev_string}
3124This is a special option to allow the monitor to be multiplexed onto
3125another serial port.  The monitor is accessed with key sequence of
3126@key{Control-a} and then pressing @key{c}.
3127@var{dev_string} should be any one of the serial devices specified
3128above.  An example to multiplex the monitor onto a telnet server
3129listening on port 4444 would be:
3130@table @code
3131@item -serial mon:telnet::4444,server,nowait
3132@end table
3133When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3134QEMU any more but will be passed to the guest instead.
3135
3136@item braille
3137Braille device.  This will use BrlAPI to display the braille output on a real
3138or fake device.
3139
3140@item msmouse
3141Three button serial mouse. Configure the guest to use Microsoft protocol.
3142@end table
3143ETEXI
3144
3145DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3146    "-parallel dev   redirect the parallel port to char device 'dev'\n",
3147    QEMU_ARCH_ALL)
3148STEXI
3149@item -parallel @var{dev}
3150@findex -parallel
3151Redirect the virtual parallel port to host device @var{dev} (same
3152devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3153be used to use hardware devices connected on the corresponding host
3154parallel port.
3155
3156This option can be used several times to simulate up to 3 parallel
3157ports.
3158
3159Use @code{-parallel none} to disable all parallel ports.
3160ETEXI
3161
3162DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3163    "-monitor dev    redirect the monitor to char device 'dev'\n",
3164    QEMU_ARCH_ALL)
3165STEXI
3166@item -monitor @var{dev}
3167@findex -monitor
3168Redirect the monitor to host device @var{dev} (same devices as the
3169serial port).
3170The default device is @code{vc} in graphical mode and @code{stdio} in
3171non graphical mode.
3172Use @code{-monitor none} to disable the default monitor.
3173ETEXI
3174DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3175    "-qmp dev        like -monitor but opens in 'control' mode\n",
3176    QEMU_ARCH_ALL)
3177STEXI
3178@item -qmp @var{dev}
3179@findex -qmp
3180Like -monitor but opens in 'control' mode.
3181ETEXI
3182DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3183    "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3184    QEMU_ARCH_ALL)
3185STEXI
3186@item -qmp-pretty @var{dev}
3187@findex -qmp-pretty
3188Like -qmp but uses pretty JSON formatting.
3189ETEXI
3190
3191DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3192    "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3193STEXI
3194@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3195@findex -mon
3196Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3197easing human reading and debugging.
3198ETEXI
3199
3200DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3201    "-debugcon dev   redirect the debug console to char device 'dev'\n",
3202    QEMU_ARCH_ALL)
3203STEXI
3204@item -debugcon @var{dev}
3205@findex -debugcon
3206Redirect the debug console to host device @var{dev} (same devices as the
3207serial port).  The debug console is an I/O port which is typically port
32080xe9; writing to that I/O port sends output to this device.
3209The default device is @code{vc} in graphical mode and @code{stdio} in
3210non graphical mode.
3211ETEXI
3212
3213DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3214    "-pidfile file   write PID to 'file'\n", QEMU_ARCH_ALL)
3215STEXI
3216@item -pidfile @var{file}
3217@findex -pidfile
3218Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3219from a script.
3220ETEXI
3221
3222DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3223    "-singlestep     always run in singlestep mode\n", QEMU_ARCH_ALL)
3224STEXI
3225@item -singlestep
3226@findex -singlestep
3227Run the emulation in single step mode.
3228ETEXI
3229
3230DEF("preconfig", 0, QEMU_OPTION_preconfig, \
3231    "--preconfig     pause QEMU before machine is initialized (experimental)\n",
3232    QEMU_ARCH_ALL)
3233STEXI
3234@item --preconfig
3235@findex --preconfig
3236Pause QEMU for interactive configuration before the machine is created,
3237which allows querying and configuring properties that will affect
3238machine initialization.  Use QMP command 'x-exit-preconfig' to exit
3239the preconfig state and move to the next state (i.e. run guest if -S
3240isn't used or pause the second time if -S is used).  This option is
3241experimental.
3242ETEXI
3243
3244DEF("S", 0, QEMU_OPTION_S, \
3245    "-S              freeze CPU at startup (use 'c' to start execution)\n",
3246    QEMU_ARCH_ALL)
3247STEXI
3248@item -S
3249@findex -S
3250Do not start CPU at startup (you must type 'c' in the monitor).
3251ETEXI
3252
3253DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3254    "-realtime [mlock=on|off]\n"
3255    "                run qemu with realtime features\n"
3256    "                mlock=on|off controls mlock support (default: on)\n",
3257    QEMU_ARCH_ALL)
3258STEXI
3259@item -realtime mlock=on|off
3260@findex -realtime
3261Run qemu with realtime features.
3262mlocking qemu and guest memory can be enabled via @option{mlock=on}
3263(enabled by default).
3264ETEXI
3265
3266DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit,
3267    "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n"
3268    "                run qemu with overcommit hints\n"
3269    "                mem-lock=on|off controls memory lock support (default: off)\n"
3270    "                cpu-pm=on|off controls cpu power management (default: off)\n",
3271    QEMU_ARCH_ALL)
3272STEXI
3273@item -overcommit mem-lock=on|off
3274@item -overcommit cpu-pm=on|off
3275@findex -overcommit
3276Run qemu with hints about host resource overcommit. The default is
3277to assume that host overcommits all resources.
3278
3279Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled
3280by default).  This works when host memory is not overcommitted and reduces the
3281worst-case latency for guest.  This is equivalent to @option{realtime}.
3282
3283Guest ability to manage power state of host cpus (increasing latency for other
3284processes on the same host cpu, but decreasing latency for guest) can be
3285enabled via @option{cpu-pm=on} (disabled by default).  This works best when
3286host CPU is not overcommitted. When used, host estimates of CPU cycle and power
3287utilization will be incorrect, not taking into account guest idle time.
3288ETEXI
3289
3290DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3291    "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3292STEXI
3293@item -gdb @var{dev}
3294@findex -gdb
3295Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3296connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3297stdio are reasonable use case. The latter is allowing to start QEMU from
3298within gdb and establish the connection via a pipe:
3299@example
3300(gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3301@end example
3302ETEXI
3303
3304DEF("s", 0, QEMU_OPTION_s, \
3305    "-s              shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3306    QEMU_ARCH_ALL)
3307STEXI
3308@item -s
3309@findex -s
3310Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3311(@pxref{gdb_usage}).
3312ETEXI
3313
3314DEF("d", HAS_ARG, QEMU_OPTION_d, \
3315    "-d item1,...    enable logging of specified items (use '-d help' for a list of log items)\n",
3316    QEMU_ARCH_ALL)
3317STEXI
3318@item -d @var{item1}[,...]
3319@findex -d
3320Enable logging of specified items. Use '-d help' for a list of log items.
3321ETEXI
3322
3323DEF("D", HAS_ARG, QEMU_OPTION_D, \
3324    "-D logfile      output log to logfile (default stderr)\n",
3325    QEMU_ARCH_ALL)
3326STEXI
3327@item -D @var{logfile}
3328@findex -D
3329Output log in @var{logfile} instead of to stderr
3330ETEXI
3331
3332DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3333    "-dfilter range,..  filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3334    QEMU_ARCH_ALL)
3335STEXI
3336@item -dfilter @var{range1}[,...]
3337@findex -dfilter
3338Filter debug output to that relevant to a range of target addresses. The filter
3339spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3340@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3341addresses and sizes required. For example:
3342@example
3343    -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3344@end example
3345Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3346the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3347block starting at 0xffffffc00005f000.
3348ETEXI
3349
3350DEF("L", HAS_ARG, QEMU_OPTION_L, \
3351    "-L path         set the directory for the BIOS, VGA BIOS and keymaps\n",
3352    QEMU_ARCH_ALL)
3353STEXI
3354@item -L  @var{path}
3355@findex -L
3356Set the directory for the BIOS, VGA BIOS and keymaps.
3357
3358To list all the data directories, use @code{-L help}.
3359ETEXI
3360
3361DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3362    "-bios file      set the filename for the BIOS\n", QEMU_ARCH_ALL)
3363STEXI
3364@item -bios @var{file}
3365@findex -bios
3366Set the filename for the BIOS.
3367ETEXI
3368
3369DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3370    "-enable-kvm     enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3371STEXI
3372@item -enable-kvm
3373@findex -enable-kvm
3374Enable KVM full virtualization support. This option is only available
3375if KVM support is enabled when compiling.
3376ETEXI
3377
3378DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3379    "-xen-domid id   specify xen guest domain id\n", QEMU_ARCH_ALL)
3380DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3381    "-xen-attach     attach to existing xen domain\n"
3382    "                libxl will use this when starting QEMU\n",
3383    QEMU_ARCH_ALL)
3384DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3385    "-xen-domid-restrict     restrict set of available xen operations\n"
3386    "                        to specified domain id. (Does not affect\n"
3387    "                        xenpv machine type).\n",
3388    QEMU_ARCH_ALL)
3389STEXI
3390@item -xen-domid @var{id}
3391@findex -xen-domid
3392Specify xen guest domain @var{id} (XEN only).
3393@item -xen-attach
3394@findex -xen-attach
3395Attach to existing xen domain.
3396libxl will use this when starting QEMU (XEN only).
3397@findex -xen-domid-restrict
3398Restrict set of available xen operations to specified domain id (XEN only).
3399ETEXI
3400
3401DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3402    "-no-reboot      exit instead of rebooting\n", QEMU_ARCH_ALL)
3403STEXI
3404@item -no-reboot
3405@findex -no-reboot
3406Exit instead of rebooting.
3407ETEXI
3408
3409DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3410    "-no-shutdown    stop before shutdown\n", QEMU_ARCH_ALL)
3411STEXI
3412@item -no-shutdown
3413@findex -no-shutdown
3414Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3415This allows for instance switching to monitor to commit changes to the
3416disk image.
3417ETEXI
3418
3419DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3420    "-loadvm [tag|id]\n" \
3421    "                start right away with a saved state (loadvm in monitor)\n",
3422    QEMU_ARCH_ALL)
3423STEXI
3424@item -loadvm @var{file}
3425@findex -loadvm
3426Start right away with a saved state (@code{loadvm} in monitor)
3427ETEXI
3428
3429#ifndef _WIN32
3430DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3431    "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3432#endif
3433STEXI
3434@item -daemonize
3435@findex -daemonize
3436Daemonize the QEMU process after initialization.  QEMU will not detach from
3437standard IO until it is ready to receive connections on any of its devices.
3438This option is a useful way for external programs to launch QEMU without having
3439to cope with initialization race conditions.
3440ETEXI
3441
3442DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3443    "-option-rom rom load a file, rom, into the option ROM space\n",
3444    QEMU_ARCH_ALL)
3445STEXI
3446@item -option-rom @var{file}
3447@findex -option-rom
3448Load the contents of @var{file} as an option ROM.
3449This option is useful to load things like EtherBoot.
3450ETEXI
3451
3452DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3453    "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3454    "                set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3455    QEMU_ARCH_ALL)
3456
3457STEXI
3458
3459@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew]
3460@findex -rtc
3461Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3462UTC or local time, respectively. @code{localtime} is required for correct date in
3463MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the
3464format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3465
3466By default the RTC is driven by the host system time. This allows using of the
3467RTC as accurate reference clock inside the guest, specifically if the host
3468time is smoothly following an accurate external reference clock, e.g. via NTP.
3469If you want to isolate the guest time from the host, you can set @option{clock}
3470to @code{rt} instead, which provides a host monotonic clock if host support it.
3471To even prevent the RTC from progressing during suspension, you can set @option{clock}
3472to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in
3473icount mode in order to preserve determinism; however, note that in icount mode
3474the speed of the virtual clock is variable and can in general differ from the
3475host clock.
3476
3477Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3478specifically with Windows' ACPI HAL. This option will try to figure out how
3479many timer interrupts were not processed by the Windows guest and will
3480re-inject them.
3481ETEXI
3482
3483DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3484    "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3485    "                enable virtual instruction counter with 2^N clock ticks per\n" \
3486    "                instruction, enable aligning the host and virtual clocks\n" \
3487    "                or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3488STEXI
3489@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3490@findex -icount
3491Enable virtual instruction counter.  The virtual cpu will execute one
3492instruction every 2^@var{N} ns of virtual time.  If @code{auto} is specified
3493then the virtual cpu speed will be automatically adjusted to keep virtual
3494time within a few seconds of real time.
3495
3496When the virtual cpu is sleeping, the virtual time will advance at default
3497speed unless @option{sleep=on|off} is specified.
3498With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3499instantly whenever the virtual cpu goes to sleep mode and will not advance
3500if no timer is enabled. This behavior give deterministic execution times from
3501the guest point of view.
3502
3503Note that while this option can give deterministic behavior, it does not
3504provide cycle accurate emulation.  Modern CPUs contain superscalar out of
3505order cores with complex cache hierarchies.  The number of instructions
3506executed often has little or no correlation with actual performance.
3507
3508@option{align=on} will activate the delay algorithm which will try
3509to synchronise the host clock and the virtual clock. The goal is to
3510have a guest running at the real frequency imposed by the shift option.
3511Whenever the guest clock is behind the host clock and if
3512@option{align=on} is specified then we print a message to the user
3513to inform about the delay.
3514Currently this option does not work when @option{shift} is @code{auto}.
3515Note: The sync algorithm will work for those shift values for which
3516the guest clock runs ahead of the host clock. Typically this happens
3517when the shift value is high (how high depends on the host machine).
3518
3519When @option{rr} option is specified deterministic record/replay is enabled.
3520Replay log is written into @var{filename} file in record mode and
3521read from this file in replay mode.
3522
3523Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3524at the start of execution recording. In replay mode this option is used
3525to load the initial VM state.
3526ETEXI
3527
3528DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3529    "-watchdog model\n" \
3530    "                enable virtual hardware watchdog [default=none]\n",
3531    QEMU_ARCH_ALL)
3532STEXI
3533@item -watchdog @var{model}
3534@findex -watchdog
3535Create a virtual hardware watchdog device.  Once enabled (by a guest
3536action), the watchdog must be periodically polled by an agent inside
3537the guest or else the guest will be restarted. Choose a model for
3538which your guest has drivers.
3539
3540The @var{model} is the model of hardware watchdog to emulate. Use
3541@code{-watchdog help} to list available hardware models. Only one
3542watchdog can be enabled for a guest.
3543
3544The following models may be available:
3545@table @option
3546@item ib700
3547iBASE 700 is a very simple ISA watchdog with a single timer.
3548@item i6300esb
3549Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3550dual-timer watchdog.
3551@item diag288
3552A virtual watchdog for s390x backed by the diagnose 288 hypercall
3553(currently KVM only).
3554@end table
3555ETEXI
3556
3557DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3558    "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3559    "                action when watchdog fires [default=reset]\n",
3560    QEMU_ARCH_ALL)
3561STEXI
3562@item -watchdog-action @var{action}
3563@findex -watchdog-action
3564
3565The @var{action} controls what QEMU will do when the watchdog timer
3566expires.
3567The default is
3568@code{reset} (forcefully reset the guest).
3569Other possible actions are:
3570@code{shutdown} (attempt to gracefully shutdown the guest),
3571@code{poweroff} (forcefully poweroff the guest),
3572@code{inject-nmi} (inject a NMI into the guest),
3573@code{pause} (pause the guest),
3574@code{debug} (print a debug message and continue), or
3575@code{none} (do nothing).
3576
3577Note that the @code{shutdown} action requires that the guest responds
3578to ACPI signals, which it may not be able to do in the sort of
3579situations where the watchdog would have expired, and thus
3580@code{-watchdog-action shutdown} is not recommended for production use.
3581
3582Examples:
3583
3584@table @code
3585@item -watchdog i6300esb -watchdog-action pause
3586@itemx -watchdog ib700
3587@end table
3588ETEXI
3589
3590DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3591    "-echr chr       set terminal escape character instead of ctrl-a\n",
3592    QEMU_ARCH_ALL)
3593STEXI
3594
3595@item -echr @var{numeric_ascii_value}
3596@findex -echr
3597Change the escape character used for switching to the monitor when using
3598monitor and serial sharing.  The default is @code{0x01} when using the
3599@code{-nographic} option.  @code{0x01} is equal to pressing
3600@code{Control-a}.  You can select a different character from the ascii
3601control keys where 1 through 26 map to Control-a through Control-z.  For
3602instance you could use the either of the following to change the escape
3603character to Control-t.
3604@table @code
3605@item -echr 0x14
3606@itemx -echr 20
3607@end table
3608ETEXI
3609
3610DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3611    "-show-cursor    show cursor\n", QEMU_ARCH_ALL)
3612STEXI
3613@item -show-cursor
3614@findex -show-cursor
3615Show cursor.
3616ETEXI
3617
3618DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3619    "-tb-size n      set TB size\n", QEMU_ARCH_ALL)
3620STEXI
3621@item -tb-size @var{n}
3622@findex -tb-size
3623Set TB size.
3624ETEXI
3625
3626DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3627    "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3628    "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3629    "-incoming unix:socketpath\n" \
3630    "                prepare for incoming migration, listen on\n" \
3631    "                specified protocol and socket address\n" \
3632    "-incoming fd:fd\n" \
3633    "-incoming exec:cmdline\n" \
3634    "                accept incoming migration on given file descriptor\n" \
3635    "                or from given external command\n" \
3636    "-incoming defer\n" \
3637    "                wait for the URI to be specified via migrate_incoming\n",
3638    QEMU_ARCH_ALL)
3639STEXI
3640@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3641@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3642@findex -incoming
3643Prepare for incoming migration, listen on a given tcp port.
3644
3645@item -incoming unix:@var{socketpath}
3646Prepare for incoming migration, listen on a given unix socket.
3647
3648@item -incoming fd:@var{fd}
3649Accept incoming migration from a given filedescriptor.
3650
3651@item -incoming exec:@var{cmdline}
3652Accept incoming migration as an output from specified external command.
3653
3654@item -incoming defer
3655Wait for the URI to be specified via migrate_incoming.  The monitor can
3656be used to change settings (such as migration parameters) prior to issuing
3657the migrate_incoming to allow the migration to begin.
3658ETEXI
3659
3660DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3661    "-only-migratable     allow only migratable devices\n", QEMU_ARCH_ALL)
3662STEXI
3663@item -only-migratable
3664@findex -only-migratable
3665Only allow migratable devices. Devices will not be allowed to enter an
3666unmigratable state.
3667ETEXI
3668
3669DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3670    "-nodefaults     don't create default devices\n", QEMU_ARCH_ALL)
3671STEXI
3672@item -nodefaults
3673@findex -nodefaults
3674Don't create default devices. Normally, QEMU sets the default devices like serial
3675port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3676CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3677default devices.
3678ETEXI
3679
3680#ifndef _WIN32
3681DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3682    "-chroot dir     chroot to dir just before starting the VM\n",
3683    QEMU_ARCH_ALL)
3684#endif
3685STEXI
3686@item -chroot @var{dir}
3687@findex -chroot
3688Immediately before starting guest execution, chroot to the specified
3689directory.  Especially useful in combination with -runas.
3690ETEXI
3691
3692#ifndef _WIN32
3693DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3694    "-runas user     change to user id user just before starting the VM\n" \
3695    "                user can be numeric uid:gid instead\n",
3696    QEMU_ARCH_ALL)
3697#endif
3698STEXI
3699@item -runas @var{user}
3700@findex -runas
3701Immediately before starting guest execution, drop root privileges, switching
3702to the specified user.
3703ETEXI
3704
3705DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3706    "-prom-env variable=value\n"
3707    "                set OpenBIOS nvram variables\n",
3708    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3709STEXI
3710@item -prom-env @var{variable}=@var{value}
3711@findex -prom-env
3712Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3713ETEXI
3714DEF("semihosting", 0, QEMU_OPTION_semihosting,
3715    "-semihosting    semihosting mode\n",
3716    QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3717    QEMU_ARCH_MIPS)
3718STEXI
3719@item -semihosting
3720@findex -semihosting
3721Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3722ETEXI
3723DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3724    "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3725    "                semihosting configuration\n",
3726QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3727QEMU_ARCH_MIPS)
3728STEXI
3729@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3730@findex -semihosting-config
3731Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3732@table @option
3733@item target=@code{native|gdb|auto}
3734Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3735or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3736during debug sessions and @code{native} otherwise.
3737@item arg=@var{str1},arg=@var{str2},...
3738Allows the user to pass input arguments, and can be used multiple times to build
3739up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3740command line is still supported for backward compatibility. If both the
3741@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3742specified, the former is passed to semihosting as it always takes precedence.
3743@end table
3744ETEXI
3745DEF("old-param", 0, QEMU_OPTION_old_param,
3746    "-old-param      old param mode\n", QEMU_ARCH_ARM)
3747STEXI
3748@item -old-param
3749@findex -old-param (ARM)
3750Old param mode (ARM only).
3751ETEXI
3752
3753DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3754    "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3755    "          [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3756    "                Enable seccomp mode 2 system call filter (default 'off').\n" \
3757    "                use 'obsolete' to allow obsolete system calls that are provided\n" \
3758    "                    by the kernel, but typically no longer used by modern\n" \
3759    "                    C library implementations.\n" \
3760    "                use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3761    "                    its privileges by blacklisting all set*uid|gid system calls.\n" \
3762    "                    The value 'children' will deny set*uid|gid system calls for\n" \
3763    "                    main QEMU process but will allow forks and execves to run unprivileged\n" \
3764    "                use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3765    "                     blacklisting *fork and execve\n" \
3766    "                use 'resourcecontrol' to disable process affinity and schedular priority\n",
3767    QEMU_ARCH_ALL)
3768STEXI
3769@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3770@findex -sandbox
3771Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3772disable it.  The default is 'off'.
3773@table @option
3774@item obsolete=@var{string}
3775Enable Obsolete system calls
3776@item elevateprivileges=@var{string}
3777Disable set*uid|gid system calls
3778@item spawn=@var{string}
3779Disable *fork and execve
3780@item resourcecontrol=@var{string}
3781Disable process affinity and schedular priority
3782@end table
3783ETEXI
3784
3785DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3786    "-readconfig <file>\n", QEMU_ARCH_ALL)
3787STEXI
3788@item -readconfig @var{file}
3789@findex -readconfig
3790Read device configuration from @var{file}. This approach is useful when you want to spawn
3791QEMU process with many command line options but you don't want to exceed the command line
3792character limit.
3793ETEXI
3794DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3795    "-writeconfig <file>\n"
3796    "                read/write config file\n", QEMU_ARCH_ALL)
3797STEXI
3798@item -writeconfig @var{file}
3799@findex -writeconfig
3800Write device configuration to @var{file}. The @var{file} can be either filename to save
3801command line and device configuration into file or dash @code{-}) character to print the
3802output to stdout. This can be later used as input file for @code{-readconfig} option.
3803ETEXI
3804
3805DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3806    "-no-user-config\n"
3807    "                do not load default user-provided config files at startup\n",
3808    QEMU_ARCH_ALL)
3809STEXI
3810@item -no-user-config
3811@findex -no-user-config
3812The @code{-no-user-config} option makes QEMU not load any of the user-provided
3813config files on @var{sysconfdir}.
3814ETEXI
3815
3816DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3817    "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3818    "                specify tracing options\n",
3819    QEMU_ARCH_ALL)
3820STEXI
3821HXCOMM This line is not accurate, as some sub-options are backend-specific but
3822HXCOMM HX does not support conditional compilation of text.
3823@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3824@findex -trace
3825@include qemu-option-trace.texi
3826ETEXI
3827
3828HXCOMM Internal use
3829DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3830DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3831
3832#ifdef __linux__
3833DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3834    "-enable-fips    enable FIPS 140-2 compliance\n",
3835    QEMU_ARCH_ALL)
3836#endif
3837STEXI
3838@item -enable-fips
3839@findex -enable-fips
3840Enable FIPS 140-2 compliance mode.
3841ETEXI
3842
3843HXCOMM Deprecated by -machine accel=tcg property
3844DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3845
3846DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3847    "-msg timestamp[=on|off]\n"
3848    "                change the format of messages\n"
3849    "                on|off controls leading timestamps (default:on)\n",
3850    QEMU_ARCH_ALL)
3851STEXI
3852@item -msg timestamp[=on|off]
3853@findex -msg
3854prepend a timestamp to each log message.(default:on)
3855ETEXI
3856
3857DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3858    "-dump-vmstate <file>\n"
3859    "                Output vmstate information in JSON format to file.\n"
3860    "                Use the scripts/vmstate-static-checker.py file to\n"
3861    "                check for possible regressions in migration code\n"
3862    "                by comparing two such vmstate dumps.\n",
3863    QEMU_ARCH_ALL)
3864STEXI
3865@item -dump-vmstate @var{file}
3866@findex -dump-vmstate
3867Dump json-encoded vmstate information for current machine type to file
3868in @var{file}
3869ETEXI
3870
3871DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
3872    "-enable-sync-profile\n"
3873    "                enable synchronization profiling\n",
3874    QEMU_ARCH_ALL)
3875STEXI
3876@item -enable-sync-profile
3877@findex -enable-sync-profile
3878Enable synchronization profiling.
3879ETEXI
3880
3881STEXI
3882@end table
3883ETEXI
3884DEFHEADING()
3885
3886DEFHEADING(Generic object creation:)
3887STEXI
3888@table @option
3889ETEXI
3890
3891DEF("object", HAS_ARG, QEMU_OPTION_object,
3892    "-object TYPENAME[,PROP1=VALUE1,...]\n"
3893    "                create a new object of type TYPENAME setting properties\n"
3894    "                in the order they are specified.  Note that the 'id'\n"
3895    "                property must be set.  These objects are placed in the\n"
3896    "                '/objects' path.\n",
3897    QEMU_ARCH_ALL)
3898STEXI
3899@item -object @var{typename}[,@var{prop1}=@var{value1},...]
3900@findex -object
3901Create a new object of type @var{typename} setting properties
3902in the order they are specified.  Note that the 'id'
3903property must be set.  These objects are placed in the
3904'/objects' path.
3905
3906@table @option
3907
3908@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}
3909
3910Creates a memory file backend object, which can be used to back
3911the guest RAM with huge pages.
3912
3913The @option{id} parameter is a unique ID that will be used to reference this
3914memory region when configuring the @option{-numa} argument.
3915
3916The @option{size} option provides the size of the memory region, and accepts
3917common suffixes, eg @option{500M}.
3918
3919The @option{mem-path} provides the path to either a shared memory or huge page
3920filesystem mount.
3921
3922The @option{share} boolean option determines whether the memory
3923region is marked as private to QEMU, or shared. The latter allows
3924a co-operating external process to access the QEMU memory region.
3925
3926The @option{share} is also required for pvrdma devices due to
3927limitations in the RDMA API provided by Linux.
3928
3929Setting share=on might affect the ability to configure NUMA
3930bindings for the memory backend under some circumstances, see
3931Documentation/vm/numa_memory_policy.txt on the Linux kernel
3932source tree for additional details.
3933
3934Setting the @option{discard-data} boolean option to @var{on}
3935indicates that file contents can be destroyed when QEMU exits,
3936to avoid unnecessarily flushing data to the backing file.  Note
3937that @option{discard-data} is only an optimization, and QEMU
3938might not discard file contents if it aborts unexpectedly or is
3939terminated using SIGKILL.
3940
3941The @option{merge} boolean option enables memory merge, also known as
3942MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
3943memory deduplication.
3944
3945Setting the @option{dump} boolean option to @var{off} excludes the memory from
3946core dumps. This feature is also known as MADV_DONTDUMP.
3947
3948The @option{prealloc} boolean option enables memory preallocation.
3949
3950The @option{host-nodes} option binds the memory range to a list of NUMA host
3951nodes.
3952
3953The @option{policy} option sets the NUMA policy to one of the following values:
3954
3955@table @option
3956@item @var{default}
3957default host policy
3958
3959@item @var{preferred}
3960prefer the given host node list for allocation
3961
3962@item @var{bind}
3963restrict memory allocation to the given host node list
3964
3965@item @var{interleave}
3966interleave memory allocations across the given host node list
3967@end table
3968
3969The @option{align} option specifies the base address alignment when
3970QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
3971@option{2M}. Some backend store specified by @option{mem-path}
3972requires an alignment different than the default one used by QEMU, eg
3973the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
3974such cases, users can specify the required alignment via this option.
3975
3976The @option{pmem} option specifies whether the backing file specified
3977by @option{mem-path} is in host persistent memory that can be accessed
3978using the SNIA NVM programming model (e.g. Intel NVDIMM).
3979If @option{pmem} is set to 'on', QEMU will take necessary operations to
3980guarantee the persistence of its own writes to @option{mem-path}
3981(e.g. in vNVDIMM label emulation and live migration).
3982
3983@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}
3984
3985Creates a memory backend object, which can be used to back the guest RAM.
3986Memory backend objects offer more control than the @option{-m} option that is
3987traditionally used to define guest RAM. Please refer to
3988@option{memory-backend-file} for a description of the options.
3989
3990@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}
3991
3992Creates an anonymous memory file backend object, which allows QEMU to
3993share the memory with an external process (e.g. when using
3994vhost-user). The memory is allocated with memfd and optional
3995sealing. (Linux only)
3996
3997The @option{seal} option creates a sealed-file, that will block
3998further resizing the memory ('on' by default).
3999
4000The @option{hugetlb} option specify the file to be created resides in
4001the hugetlbfs filesystem (since Linux 4.14).  Used in conjunction with
4002the @option{hugetlb} option, the @option{hugetlbsize} option specify
4003the hugetlb page size on systems that support multiple hugetlb page
4004sizes (it must be a power of 2 value supported by the system).
4005
4006In some versions of Linux, the @option{hugetlb} option is incompatible
4007with the @option{seal} option (requires at least Linux 4.16).
4008
4009Please refer to @option{memory-backend-file} for a description of the
4010other options.
4011
4012The @option{share} boolean option is @var{on} by default with memfd.
4013
4014@item -object rng-random,id=@var{id},filename=@var{/dev/random}
4015
4016Creates a random number generator backend which obtains entropy from
4017a device on the host. The @option{id} parameter is a unique ID that
4018will be used to reference this entropy backend from the @option{virtio-rng}
4019device. The @option{filename} parameter specifies which file to obtain
4020entropy from and if omitted defaults to @option{/dev/random}.
4021
4022@item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4023
4024Creates a random number generator backend which obtains entropy from
4025an external daemon running on the host. The @option{id} parameter is
4026a unique ID that will be used to reference this entropy backend from
4027the @option{virtio-rng} device. The @option{chardev} parameter is
4028the unique ID of a character device backend that provides the connection
4029to the RNG daemon.
4030
4031@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4032
4033Creates a TLS anonymous credentials object, which can be used to provide
4034TLS support on network backends. The @option{id} parameter is a unique
4035ID which network backends will use to access the credentials. The
4036@option{endpoint} is either @option{server} or @option{client} depending
4037on whether the QEMU network backend that uses the credentials will be
4038acting as a client or as a server. If @option{verify-peer} is enabled
4039(the default) then once the handshake is completed, the peer credentials
4040will be verified, though this is a no-op for anonymous credentials.
4041
4042The @var{dir} parameter tells QEMU where to find the credential
4043files. For server endpoints, this directory may contain a file
4044@var{dh-params.pem} providing diffie-hellman parameters to use
4045for the TLS server. If the file is missing, QEMU will generate
4046a set of DH parameters at startup. This is a computationally
4047expensive operation that consumes random pool entropy, so it is
4048recommended that a persistent set of parameters be generated
4049upfront and saved.
4050
4051@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}]
4052
4053Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide
4054TLS support on network backends. The @option{id} parameter is a unique
4055ID which network backends will use to access the credentials. The
4056@option{endpoint} is either @option{server} or @option{client} depending
4057on whether the QEMU network backend that uses the credentials will be
4058acting as a client or as a server. For clients only, @option{username}
4059is the username which will be sent to the server.  If omitted
4060it defaults to ``qemu''.
4061
4062The @var{dir} parameter tells QEMU where to find the keys file.
4063It is called ``@var{dir}/keys.psk'' and contains ``username:key''
4064pairs.  This file can most easily be created using the GnuTLS
4065@code{psktool} program.
4066
4067For server endpoints, @var{dir} may also contain a file
4068@var{dh-params.pem} providing diffie-hellman parameters to use
4069for the TLS server. If the file is missing, QEMU will generate
4070a set of DH parameters at startup. This is a computationally
4071expensive operation that consumes random pool entropy, so it is
4072recommended that a persistent set of parameters be generated
4073up front and saved.
4074
4075@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}
4076
4077Creates a TLS anonymous credentials object, which can be used to provide
4078TLS support on network backends. The @option{id} parameter is a unique
4079ID which network backends will use to access the credentials. The
4080@option{endpoint} is either @option{server} or @option{client} depending
4081on whether the QEMU network backend that uses the credentials will be
4082acting as a client or as a server. If @option{verify-peer} is enabled
4083(the default) then once the handshake is completed, the peer credentials
4084will be verified. With x509 certificates, this implies that the clients
4085must be provided with valid client certificates too.
4086
4087The @var{dir} parameter tells QEMU where to find the credential
4088files. For server endpoints, this directory may contain a file
4089@var{dh-params.pem} providing diffie-hellman parameters to use
4090for the TLS server. If the file is missing, QEMU will generate
4091a set of DH parameters at startup. This is a computationally
4092expensive operation that consumes random pool entropy, so it is
4093recommended that a persistent set of parameters be generated
4094upfront and saved.
4095
4096For x509 certificate credentials the directory will contain further files
4097providing the x509 certificates. The certificates must be stored
4098in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4099@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4100@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4101
4102For the @var{server-key.pem} and @var{client-key.pem} files which
4103contain sensitive private keys, it is possible to use an encrypted
4104version by providing the @var{passwordid} parameter. This provides
4105the ID of a previously created @code{secret} object containing the
4106password for decryption.
4107
4108The @var{priority} parameter allows to override the global default
4109priority used by gnutls. This can be useful if the system administrator
4110needs to use a weaker set of crypto priorities for QEMU without
4111potentially forcing the weakness onto all applications. Or conversely
4112if one wants wants a stronger default for QEMU than for all other
4113applications, they can do this through this parameter. Its format is
4114a gnutls priority string as described at
4115@url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4116
4117@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4118
4119Interval @var{t} can't be 0, this filter batches the packet delivery: all
4120packets arriving in a given interval on netdev @var{netdevid} are delayed
4121until the end of the interval. Interval is in microseconds.
4122@option{status} is optional that indicate whether the netfilter is
4123on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4124
4125queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4126
4127@option{all}: the filter is attached both to the receive and the transmit
4128              queue of the netdev (default).
4129
4130@option{rx}: the filter is attached to the receive queue of the netdev,
4131             where it will receive packets sent to the netdev.
4132
4133@option{tx}: the filter is attached to the transmit queue of the netdev,
4134             where it will receive packets sent by the netdev.
4135
4136@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4137
4138filter-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.
4139
4140@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4141
4142filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4143@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4144filter-redirector will redirect packet with vnet_hdr_len.
4145Create a filter-redirector we need to differ outdev id from indev id, id can not
4146be the same. we can just use indev or outdev, but at least one of indev or outdev
4147need to be specified.
4148
4149@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4150
4151Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4152secondary from primary to keep secondary tcp connection,and rewrite
4153tcp packet to primary from secondary make tcp packet can be handled by
4154client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4155
4156usage:
4157colo secondary:
4158-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4159-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4160-object filter-rewriter,id=rew0,netdev=hn0,queue=all
4161
4162@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4163
4164Dump the network traffic on netdev @var{dev} to the file specified by
4165@var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4166The file format is libpcap, so it can be analyzed with tools such as tcpdump
4167or Wireshark.
4168
4169@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4170
4171Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4172secondary packet. If the packets are same, we will output primary
4173packet to outdev@var{chardevid}, else we will notify colo-frame
4174do checkpoint and send primary packet to outdev@var{chardevid}.
4175if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4176
4177we must use it with the help of filter-mirror and filter-redirector.
4178
4179@example
4180
4181primary:
4182-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4183-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4184-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4185-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4186-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4187-chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4188-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4189-chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4190-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4191-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4192-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4193-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4194
4195secondary:
4196-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4197-device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4198-chardev socket,id=red0,host=3.3.3.3,port=9003
4199-chardev socket,id=red1,host=3.3.3.3,port=9004
4200-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4201-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4202
4203@end example
4204
4205If you want to know the detail of above command line, you can read
4206the colo-compare git log.
4207
4208@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4209
4210Creates a cryptodev backend which executes crypto opreation from
4211the QEMU cipher APIS. The @var{id} parameter is
4212a unique ID that will be used to reference this cryptodev backend from
4213the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4214which specify the queue number of cryptodev backend, the default of
4215@var{queues} is 1.
4216
4217@example
4218
4219 # qemu-system-x86_64 \
4220   [...] \
4221       -object cryptodev-backend-builtin,id=cryptodev0 \
4222       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4223   [...]
4224@end example
4225
4226@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4227
4228Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4229The @var{id} parameter is a unique ID that will be used to reference this
4230cryptodev backend from the @option{virtio-crypto} device.
4231The chardev should be a unix domain socket backed one. The vhost-user uses
4232a specifically defined protocol to pass vhost ioctl replacement messages
4233to an application on the other end of the socket.
4234The @var{queues} parameter is optional, which specify the queue number
4235of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4236
4237@example
4238
4239 # qemu-system-x86_64 \
4240   [...] \
4241       -chardev socket,id=chardev0,path=/path/to/socket \
4242       -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4243       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4244   [...]
4245@end example
4246
4247@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4248@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4249
4250Defines a secret to store a password, encryption key, or some other sensitive
4251data. The sensitive data can either be passed directly via the @var{data}
4252parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4253parameter is insecure unless the sensitive data is encrypted.
4254
4255The sensitive data can be provided in raw format (the default), or base64.
4256When encoded as JSON, the raw format only supports valid UTF-8 characters,
4257so base64 is recommended for sending binary data. QEMU will convert from
4258which ever format is provided to the format it needs internally. eg, an
4259RBD password can be provided in raw format, even though it will be base64
4260encoded when passed onto the RBD sever.
4261
4262For added protection, it is possible to encrypt the data associated with
4263a secret using the AES-256-CBC cipher. Use of encryption is indicated
4264by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4265parameter provides the ID of a previously defined secret that contains
4266the AES-256 decryption key. This key should be 32-bytes long and be
4267base64 encoded. The @var{iv} parameter provides the random initialization
4268vector used for encryption of this particular secret and should be a
4269base64 encrypted string of the 16-byte IV.
4270
4271The simplest (insecure) usage is to provide the secret inline
4272
4273@example
4274
4275 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4276
4277@end example
4278
4279The simplest secure usage is to provide the secret via a file
4280
4281 # printf "letmein" > mypasswd.txt
4282 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4283
4284For greater security, AES-256-CBC should be used. To illustrate usage,
4285consider the openssl command line tool which can encrypt the data. Note
4286that when encrypting, the plaintext must be padded to the cipher block
4287size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4288
4289First a master key needs to be created in base64 encoding:
4290
4291@example
4292 # openssl rand -base64 32 > key.b64
4293 # KEY=$(base64 -d key.b64 | hexdump  -v -e '/1 "%02X"')
4294@end example
4295
4296Each secret to be encrypted needs to have a random initialization vector
4297generated. These do not need to be kept secret
4298
4299@example
4300 # openssl rand -base64 16 > iv.b64
4301 # IV=$(base64 -d iv.b64 | hexdump  -v -e '/1 "%02X"')
4302@end example
4303
4304The secret to be defined can now be encrypted, in this case we're
4305telling openssl to base64 encode the result, but it could be left
4306as raw bytes if desired.
4307
4308@example
4309 # SECRET=$(printf "letmein" |
4310            openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4311@end example
4312
4313When launching QEMU, create a master secret pointing to @code{key.b64}
4314and specify that to be used to decrypt the user password. Pass the
4315contents of @code{iv.b64} to the second secret
4316
4317@example
4318 # $QEMU \
4319     -object secret,id=secmaster0,format=base64,file=key.b64 \
4320     -object secret,id=sec0,keyid=secmaster0,format=base64,\
4321         data=$SECRET,iv=$(<iv.b64)
4322@end example
4323
4324@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}]
4325
4326Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4327to provide the guest memory encryption support on AMD processors.
4328
4329When memory encryption is enabled, one of the physical address bit (aka the
4330C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4331is used to provide the C-bit position. The C-bit position is Host family dependent
4332hence user must provide this value. On EPYC, the value should be 47.
4333
4334When memory encryption is enabled, we loose certain bits in physical address space.
4335The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4336physical address space. Similar to C-bit, the value is Host family dependent.
4337On EPYC, the value should be 5.
4338
4339The @option{sev-device} provides the device file to use for communicating with
4340the SEV firmware running inside AMD Secure Processor. The default device is
4341'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are
4342created by CCP driver.
4343
4344The @option{policy} provides the guest policy to be enforced by the SEV firmware
4345and restrict what configuration and operational commands can be performed on this
4346guest by the hypervisor. The policy should be provided by the guest owner and is
4347bound to the guest and cannot be changed throughout the lifetime of the guest.
4348The default is 0.
4349
4350If guest @option{policy} allows sharing the key with another SEV guest then
4351@option{handle} can be use to provide handle of the guest from which to share
4352the key.
4353
4354The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4355Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters
4356are used for establishing a cryptographic session with the guest owner to
4357negotiate keys used for attestation. The file must be encoded in base64.
4358
4359e.g to launch a SEV guest
4360@example
4361 # $QEMU \
4362     ......
4363     -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \
4364     -machine ...,memory-encryption=sev0
4365     .....
4366
4367@end example
4368
4369
4370@item -object authz-simple,id=@var{id},identity=@var{string}
4371
4372Create an authorization object that will control access to network services.
4373
4374The @option{identity} parameter is identifies the user and its format
4375depends on the network service that authorization object is associated
4376with. For authorizing based on TLS x509 certificates, the identity must
4377be the x509 distinguished name. Note that care must be taken to escape
4378any commas in the distinguished name.
4379
4380An example authorization object to validate a x509 distinguished name
4381would look like:
4382@example
4383 # $QEMU \
4384     ...
4385     -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \
4386     ...
4387@end example
4388
4389Note the use of quotes due to the x509 distinguished name containing
4390whitespace, and escaping of ','.
4391
4392@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no}
4393
4394Create an authorization object that will control access to network services.
4395
4396The @option{filename} parameter is the fully qualified path to a file
4397containing the access control list rules in JSON format.
4398
4399An example set of rules that match against SASL usernames might look
4400like:
4401
4402@example
4403  @{
4404    "rules": [
4405       @{ "match": "fred", "policy": "allow", "format": "exact" @},
4406       @{ "match": "bob", "policy": "allow", "format": "exact" @},
4407       @{ "match": "danb", "policy": "deny", "format": "glob" @},
4408       @{ "match": "dan*", "policy": "allow", "format": "exact" @},
4409    ],
4410    "policy": "deny"
4411  @}
4412@end example
4413
4414When checking access the object will iterate over all the rules and
4415the first rule to match will have its @option{policy} value returned
4416as the result. If no rules match, then the default @option{policy}
4417value is returned.
4418
4419The rules can either be an exact string match, or they can use the
4420simple UNIX glob pattern matching to allow wildcards to be used.
4421
4422If @option{refresh} is set to true the file will be monitored
4423and automatically reloaded whenever its content changes.
4424
4425As with the @code{authz-simple} object, the format of the identity
4426strings being matched depends on the network service, but is usually
4427a TLS x509 distinguished name, or a SASL username.
4428
4429An example authorization object to validate a SASL username
4430would look like:
4431@example
4432 # $QEMU \
4433     ...
4434     -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes
4435     ...
4436@end example
4437
4438@item -object authz-pam,id=@var{id},service=@var{string}
4439
4440Create an authorization object that will control access to network services.
4441
4442The @option{service} parameter provides the name of a PAM service to use
4443for authorization. It requires that a file @code{/etc/pam.d/@var{service}}
4444exist to provide the configuration for the @code{account} subsystem.
4445
4446An example authorization object to validate a TLS x509 distinguished
4447name would look like:
4448
4449@example
4450 # $QEMU \
4451     ...
4452     -object authz-pam,id=auth0,service=qemu-vnc
4453     ...
4454@end example
4455
4456There would then be a corresponding config file for PAM at
4457@code{/etc/pam.d/qemu-vnc} that contains:
4458
4459@example
4460account requisite  pam_listfile.so item=user sense=allow \
4461           file=/etc/qemu/vnc.allow
4462@end example
4463
4464Finally the @code{/etc/qemu/vnc.allow} file would contain
4465the list of x509 distingished names that are permitted
4466access
4467
4468@example
4469CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB
4470@end example
4471
4472
4473@end table
4474
4475ETEXI
4476
4477
4478HXCOMM This is the last statement. Insert new options before this line!
4479STEXI
4480@end table
4481ETEXI
4482