xref: /openbmc/qemu/qemu-options.hx (revision 4a4ff4c5)
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    "                s390-squash-mcss=on|off (deprecated) controls support for squashing into default css (default=off)\n"
47    "                memory-encryption=@var{} memory encryption object to use (default=none)\n",
48    QEMU_ARCH_ALL)
49STEXI
50@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
51@findex -machine
52Select the emulated machine by @var{name}. Use @code{-machine help} to list
53available machines.
54
55For architectures which aim to support live migration compatibility
56across releases, each release will introduce a new versioned machine
57type. For example, the 2.8.0 release introduced machine types
58``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures.
59
60To allow live migration of guests from QEMU version 2.8.0, to QEMU
61version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8''
62and ``pc-q35-2.8'' machines too. To allow users live migrating VMs
63to skip multiple intermediate releases when upgrading, new releases
64of QEMU will support machine types from many previous versions.
65
66Supported machine properties are:
67@table @option
68@item accel=@var{accels1}[:@var{accels2}[:...]]
69This is used to enable an accelerator. Depending on the target architecture,
70kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
71more than one accelerator specified, the next one is used if the previous one
72fails to initialize.
73@item kernel_irqchip=on|off
74Controls in-kernel irqchip support for the chosen accelerator when available.
75@item gfx_passthru=on|off
76Enables IGD GFX passthrough support for the chosen machine when available.
77@item vmport=on|off|auto
78Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
79value based on accel. For accel=xen the default is off otherwise the default
80is on.
81@item kvm_shadow_mem=size
82Defines the size of the KVM shadow MMU.
83@item dump-guest-core=on|off
84Include guest memory in a core dump. The default is on.
85@item mem-merge=on|off
86Enables or disables memory merge support. This feature, when supported by
87the host, de-duplicates identical memory pages among VMs instances
88(enabled by default).
89@item aes-key-wrap=on|off
90Enables or disables AES key wrapping support on s390-ccw hosts. This feature
91controls whether AES wrapping keys will be created to allow
92execution of AES cryptographic functions.  The default is on.
93@item dea-key-wrap=on|off
94Enables or disables DEA key wrapping support on s390-ccw hosts. This feature
95controls whether DEA wrapping keys will be created to allow
96execution of DEA cryptographic functions.  The default is on.
97@item nvdimm=on|off
98Enables or disables NVDIMM support. The default is off.
99@item s390-squash-mcss=on|off
100Enables or disables squashing subchannels into the default css.
101The default is off.
102NOTE: This property is deprecated and will be removed in future releases.
103The ``s390-squash-mcss=on`` property has been obsoleted by allowing the
104cssid to be chosen freely. Instead of squashing subchannels into the
105default channel subsystem image for guests that do not support multiple
106channel subsystems, all devices can be put into the default channel
107subsystem image.
108@item enforce-config-section=on|off
109If @option{enforce-config-section} is set to @var{on}, force migration
110code to send configuration section even if the machine-type sets the
111@option{migration.send-configuration} property to @var{off}.
112NOTE: this parameter is deprecated. Please use @option{-global}
113@option{migration.send-configuration}=@var{on|off} instead.
114@item memory-encryption=@var{}
115Memory encryption object to use. The default is none.
116@end table
117ETEXI
118
119HXCOMM Deprecated by -machine
120DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
121
122DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
123    "-cpu cpu        select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
124STEXI
125@item -cpu @var{model}
126@findex -cpu
127Select CPU model (@code{-cpu help} for list and additional feature selection)
128ETEXI
129
130DEF("accel", HAS_ARG, QEMU_OPTION_accel,
131    "-accel [accel=]accelerator[,thread=single|multi]\n"
132    "                select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n"
133    "                thread=single|multi (enable multi-threaded TCG)", QEMU_ARCH_ALL)
134STEXI
135@item -accel @var{name}[,prop=@var{value}[,...]]
136@findex -accel
137This is used to enable an accelerator. Depending on the target architecture,
138kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
139more than one accelerator specified, the next one is used if the previous one
140fails to initialize.
141@table @option
142@item thread=single|multi
143Controls number of TCG threads. When the TCG is multi-threaded there will be one
144thread per vCPU therefor taking advantage of additional host cores. The default
145is to enable multi-threading where both the back-end and front-ends support it and
146no incompatible TCG features have been enabled (e.g. icount/replay).
147@end table
148ETEXI
149
150DEF("smp", HAS_ARG, QEMU_OPTION_smp,
151    "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
152    "                set the number of CPUs to 'n' [default=1]\n"
153    "                maxcpus= maximum number of total cpus, including\n"
154    "                offline CPUs for hotplug, etc\n"
155    "                cores= number of CPU cores on one socket\n"
156    "                threads= number of threads on one CPU core\n"
157    "                sockets= number of discrete sockets in the system\n",
158        QEMU_ARCH_ALL)
159STEXI
160@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
161@findex -smp
162Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
163CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
164to 4.
165For the PC target, the number of @var{cores} per socket, the number
166of @var{threads} per cores and the total number of @var{sockets} can be
167specified. Missing values will be computed. If any on the three values is
168given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
169specifies the maximum number of hotpluggable CPUs.
170ETEXI
171
172DEF("numa", HAS_ARG, QEMU_OPTION_numa,
173    "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
174    "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
175    "-numa dist,src=source,dst=destination,val=distance\n"
176    "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n",
177    QEMU_ARCH_ALL)
178STEXI
179@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
180@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
181@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance}
182@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}]
183@findex -numa
184Define a NUMA node and assign RAM and VCPUs to it.
185Set the NUMA distance from a source node to a destination node.
186
187Legacy VCPU assignment uses @samp{cpus} option where
188@var{firstcpu} and @var{lastcpu} are CPU indexes. Each
189@samp{cpus} option represent a contiguous range of CPU indexes
190(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous
191set of VCPUs can be represented by providing multiple @samp{cpus}
192options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically
193split between them.
194
195For example, the following option assigns VCPUs 0, 1, 2 and 5 to
196a NUMA node:
197@example
198-numa node,cpus=0-2,cpus=5
199@end example
200
201@samp{cpu} option is a new alternative to @samp{cpus} option
202which uses @samp{socket-id|core-id|thread-id} properties to assign
203CPU objects to a @var{node} using topology layout properties of CPU.
204The set of properties is machine specific, and depends on used
205machine type/@samp{smp} options. It could be queried with
206@samp{hotpluggable-cpus} monitor command.
207@samp{node-id} property specifies @var{node} to which CPU object
208will be assigned, it's required for @var{node} to be declared
209with @samp{node} option before it's used with @samp{cpu} option.
210
211For example:
212@example
213-M pc \
214-smp 1,sockets=2,maxcpus=2 \
215-numa node,nodeid=0 -numa node,nodeid=1 \
216-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
217@end example
218
219@samp{mem} assigns a given RAM amount to a node. @samp{memdev}
220assigns RAM from a given memory backend device to a node. If
221@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is
222split equally between them.
223
224@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
225if one node uses @samp{memdev}, all of them have to use it.
226
227@var{source} and @var{destination} are NUMA node IDs.
228@var{distance} is the NUMA distance from @var{source} to @var{destination}.
229The distance from a node to itself is always 10. If any pair of nodes is
230given a distance, then all pairs must be given distances. Although, when
231distances are only given in one direction for each pair of nodes, then
232the distances in the opposite directions are assumed to be the same. If,
233however, an asymmetrical pair of distances is given for even one node
234pair, then all node pairs must be provided distance values for both
235directions, even when they are symmetrical. When a node is unreachable
236from another node, set the pair's distance to 255.
237
238Note that the -@option{numa} option doesn't allocate any of the
239specified resources, it just assigns existing resources to NUMA
240nodes. This means that one still has to use the @option{-m},
241@option{-smp} options to allocate RAM and VCPUs respectively.
242
243ETEXI
244
245DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
246    "-add-fd fd=fd,set=set[,opaque=opaque]\n"
247    "                Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
248STEXI
249@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
250@findex -add-fd
251
252Add a file descriptor to an fd set.  Valid options are:
253
254@table @option
255@item fd=@var{fd}
256This option defines the file descriptor of which a duplicate is added to fd set.
257The file descriptor cannot be stdin, stdout, or stderr.
258@item set=@var{set}
259This option defines the ID of the fd set to add the file descriptor to.
260@item opaque=@var{opaque}
261This option defines a free-form string that can be used to describe @var{fd}.
262@end table
263
264You can open an image using pre-opened file descriptors from an fd set:
265@example
266qemu-system-i386
267-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
268-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
269-drive file=/dev/fdset/2,index=0,media=disk
270@end example
271ETEXI
272
273DEF("set", HAS_ARG, QEMU_OPTION_set,
274    "-set group.id.arg=value\n"
275    "                set <arg> parameter for item <id> of type <group>\n"
276    "                i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
277STEXI
278@item -set @var{group}.@var{id}.@var{arg}=@var{value}
279@findex -set
280Set parameter @var{arg} for item @var{id} of type @var{group}
281ETEXI
282
283DEF("global", HAS_ARG, QEMU_OPTION_global,
284    "-global driver.property=value\n"
285    "-global driver=driver,property=property,value=value\n"
286    "                set a global default for a driver property\n",
287    QEMU_ARCH_ALL)
288STEXI
289@item -global @var{driver}.@var{prop}=@var{value}
290@itemx -global driver=@var{driver},property=@var{property},value=@var{value}
291@findex -global
292Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
293
294@example
295qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
296@end example
297
298In particular, you can use this to set driver properties for devices which are
299created automatically by the machine model. To create a device which is not
300created automatically and set properties on it, use -@option{device}.
301
302-global @var{driver}.@var{prop}=@var{value} is shorthand for -global
303driver=@var{driver},property=@var{prop},value=@var{value}.  The
304longhand syntax works even when @var{driver} contains a dot.
305ETEXI
306
307DEF("boot", HAS_ARG, QEMU_OPTION_boot,
308    "-boot [order=drives][,once=drives][,menu=on|off]\n"
309    "      [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
310    "                'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
311    "                'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
312    "                'sp_time': the period that splash picture last if menu=on, unit is ms\n"
313    "                'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
314    QEMU_ARCH_ALL)
315STEXI
316@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]
317@findex -boot
318Specify boot order @var{drives} as a string of drive letters. Valid
319drive letters depend on the target architecture. The x86 PC uses: a, b
320(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
321from network adapter 1-4), hard disk boot is the default. To apply a
322particular boot order only on the first startup, specify it via
323@option{once}. Note that the @option{order} or @option{once} parameter
324should not be used together with the @option{bootindex} property of
325devices, since the firmware implementations normally do not support both
326at the same time.
327
328Interactive boot menus/prompts can be enabled via @option{menu=on} as far
329as firmware/BIOS supports them. The default is non-interactive boot.
330
331A splash picture could be passed to bios, enabling user to show it as logo,
332when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
333supports them. Currently Seabios for X86 system support it.
334limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
335format(true color). The resolution should be supported by the SVGA mode, so
336the recommended is 320x240, 640x480, 800x640.
337
338A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
339when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
340reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
341system support it.
342
343Do strict boot via @option{strict=on} as far as firmware/BIOS
344supports it. This only effects when boot priority is changed by
345bootindex options. The default is non-strict boot.
346
347@example
348# try to boot from network first, then from hard disk
349qemu-system-i386 -boot order=nc
350# boot from CD-ROM first, switch back to default order after reboot
351qemu-system-i386 -boot once=d
352# boot with a splash picture for 5 seconds.
353qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
354@end example
355
356Note: The legacy format '-boot @var{drives}' is still supported but its
357use is discouraged as it may be removed from future versions.
358ETEXI
359
360DEF("m", HAS_ARG, QEMU_OPTION_m,
361    "-m [size=]megs[,slots=n,maxmem=size]\n"
362    "                configure guest RAM\n"
363    "                size: initial amount of guest memory\n"
364    "                slots: number of hotplug slots (default: none)\n"
365    "                maxmem: maximum amount of guest memory (default: none)\n"
366    "NOTE: Some architectures might enforce a specific granularity\n",
367    QEMU_ARCH_ALL)
368STEXI
369@item -m [size=]@var{megs}[,slots=n,maxmem=size]
370@findex -m
371Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
372Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
373megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
374could be used to set amount of hotpluggable memory slots and maximum amount of
375memory. Note that @var{maxmem} must be aligned to the page size.
376
377For example, the following command-line sets the guest startup RAM size to
3781GB, creates 3 slots to hotplug additional memory and sets the maximum
379memory the guest can reach to 4GB:
380
381@example
382qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
383@end example
384
385If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
386be enabled and the guest startup RAM will never increase.
387ETEXI
388
389DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
390    "-mem-path FILE  provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
391STEXI
392@item -mem-path @var{path}
393@findex -mem-path
394Allocate guest RAM from a temporarily created file in @var{path}.
395ETEXI
396
397DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
398    "-mem-prealloc   preallocate guest memory (use with -mem-path)\n",
399    QEMU_ARCH_ALL)
400STEXI
401@item -mem-prealloc
402@findex -mem-prealloc
403Preallocate memory when using -mem-path.
404ETEXI
405
406DEF("k", HAS_ARG, QEMU_OPTION_k,
407    "-k language     use keyboard layout (for example 'fr' for French)\n",
408    QEMU_ARCH_ALL)
409STEXI
410@item -k @var{language}
411@findex -k
412Use keyboard layout @var{language} (for example @code{fr} for
413French). This option is only needed where it is not easy to get raw PC
414keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
415display). You don't normally need to use it on PC/Linux or PC/Windows
416hosts.
417
418The available layouts are:
419@example
420ar  de-ch  es  fo     fr-ca  hu  ja  mk     no  pt-br  sv
421da  en-gb  et  fr     fr-ch  is  lt  nl     pl  ru     th
422de  en-us  fi  fr-be  hr     it  lv  nl-be  pt  sl     tr
423@end example
424
425The default is @code{en-us}.
426ETEXI
427
428
429DEF("audio-help", 0, QEMU_OPTION_audio_help,
430    "-audio-help     print list of audio drivers and their options\n",
431    QEMU_ARCH_ALL)
432STEXI
433@item -audio-help
434@findex -audio-help
435Will show the audio subsystem help: list of drivers, tunable
436parameters.
437ETEXI
438
439DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
440    "-soundhw c1,... enable audio support\n"
441    "                and only specified sound cards (comma separated list)\n"
442    "                use '-soundhw help' to get the list of supported cards\n"
443    "                use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
444STEXI
445@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
446@findex -soundhw
447Enable audio and selected sound hardware. Use 'help' to print all
448available sound hardware.
449
450@example
451qemu-system-i386 -soundhw sb16,adlib disk.img
452qemu-system-i386 -soundhw es1370 disk.img
453qemu-system-i386 -soundhw ac97 disk.img
454qemu-system-i386 -soundhw hda disk.img
455qemu-system-i386 -soundhw all disk.img
456qemu-system-i386 -soundhw help
457@end example
458
459Note that Linux's i810_audio OSS kernel (for AC97) module might
460require manually specifying clocking.
461
462@example
463modprobe i810_audio clocking=48000
464@end example
465ETEXI
466
467DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
468    "-balloon virtio[,addr=str]\n"
469    "                enable virtio balloon device (deprecated)\n", QEMU_ARCH_ALL)
470STEXI
471@item -balloon virtio[,addr=@var{addr}]
472@findex -balloon
473Enable virtio balloon device, optionally with PCI address @var{addr}. This
474option is deprecated, use @option{--device virtio-balloon} instead.
475ETEXI
476
477DEF("device", HAS_ARG, QEMU_OPTION_device,
478    "-device driver[,prop[=value][,...]]\n"
479    "                add device (based on driver)\n"
480    "                prop=value,... sets driver properties\n"
481    "                use '-device help' to print all possible drivers\n"
482    "                use '-device driver,help' to print all possible properties\n",
483    QEMU_ARCH_ALL)
484STEXI
485@item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
486@findex -device
487Add device @var{driver}.  @var{prop}=@var{value} sets driver
488properties.  Valid properties depend on the driver.  To get help on
489possible drivers and properties, use @code{-device help} and
490@code{-device @var{driver},help}.
491
492Some drivers are:
493@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
494
495Add an IPMI BMC.  This is a simulation of a hardware management
496interface processor that normally sits on a system.  It provides
497a watchdog and the ability to reset and power control the system.
498You need to connect this to an IPMI interface to make it useful
499
500The IPMI slave address to use for the BMC.  The default is 0x20.
501This address is the BMC's address on the I2C network of management
502controllers.  If you don't know what this means, it is safe to ignore
503it.
504
505@table @option
506@item bmc=@var{id}
507The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
508@item slave_addr=@var{val}
509Define slave address to use for the BMC.  The default is 0x20.
510@item sdrfile=@var{file}
511file containing raw Sensor Data Records (SDR) data. The default is none.
512@item fruareasize=@var{val}
513size of a Field Replaceable Unit (FRU) area.  The default is 1024.
514@item frudatafile=@var{file}
515file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
516@end table
517
518@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
519
520Add a connection to an external IPMI BMC simulator.  Instead of
521locally emulating the BMC like the above item, instead connect
522to an external entity that provides the IPMI services.
523
524A connection is made to an external BMC simulator.  If you do this, it
525is strongly recommended that you use the "reconnect=" chardev option
526to reconnect to the simulator if the connection is lost.  Note that if
527this is not used carefully, it can be a security issue, as the
528interface has the ability to send resets, NMIs, and power off the VM.
529It's best if QEMU makes a connection to an external simulator running
530on a secure port on localhost, so neither the simulator nor QEMU is
531exposed to any outside network.
532
533See the "lanserv/README.vm" file in the OpenIPMI library for more
534details on the external interface.
535
536@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
537
538Add a KCS IPMI interafce on the ISA bus.  This also adds a
539corresponding ACPI and SMBIOS entries, if appropriate.
540
541@table @option
542@item bmc=@var{id}
543The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
544@item ioport=@var{val}
545Define the I/O address of the interface.  The default is 0xca0 for KCS.
546@item irq=@var{val}
547Define the interrupt to use.  The default is 5.  To disable interrupts,
548set this to 0.
549@end table
550
551@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
552
553Like the KCS interface, but defines a BT interface.  The default port is
5540xe4 and the default interrupt is 5.
555
556ETEXI
557
558DEF("name", HAS_ARG, QEMU_OPTION_name,
559    "-name string1[,process=string2][,debug-threads=on|off]\n"
560    "                set the name of the guest\n"
561    "                string1 sets the window title and string2 the process name (on Linux)\n"
562    "                When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
563    "                NOTE: The thread names are for debugging and not a stable API.\n",
564    QEMU_ARCH_ALL)
565STEXI
566@item -name @var{name}
567@findex -name
568Sets the @var{name} of the guest.
569This name will be displayed in the SDL window caption.
570The @var{name} will also be used for the VNC server.
571Also optionally set the top visible process name in Linux.
572Naming of individual threads can also be enabled on Linux to aid debugging.
573ETEXI
574
575DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
576    "-uuid %08x-%04x-%04x-%04x-%012x\n"
577    "                specify machine UUID\n", QEMU_ARCH_ALL)
578STEXI
579@item -uuid @var{uuid}
580@findex -uuid
581Set system UUID.
582ETEXI
583
584STEXI
585@end table
586ETEXI
587DEFHEADING()
588
589DEFHEADING(Block device options:)
590STEXI
591@table @option
592ETEXI
593
594DEF("fda", HAS_ARG, QEMU_OPTION_fda,
595    "-fda/-fdb file  use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
596DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
597STEXI
598@item -fda @var{file}
599@itemx -fdb @var{file}
600@findex -fda
601@findex -fdb
602Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
603ETEXI
604
605DEF("hda", HAS_ARG, QEMU_OPTION_hda,
606    "-hda/-hdb file  use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
607DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
608DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
609    "-hdc/-hdd file  use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
610DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
611STEXI
612@item -hda @var{file}
613@itemx -hdb @var{file}
614@itemx -hdc @var{file}
615@itemx -hdd @var{file}
616@findex -hda
617@findex -hdb
618@findex -hdc
619@findex -hdd
620Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
621ETEXI
622
623DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
624    "-cdrom file     use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
625    QEMU_ARCH_ALL)
626STEXI
627@item -cdrom @var{file}
628@findex -cdrom
629Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
630@option{-cdrom} at the same time). You can use the host CD-ROM by
631using @file{/dev/cdrom} as filename (@pxref{host_drives}).
632ETEXI
633
634DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
635    "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
636    "          [,cache.direct=on|off][,cache.no-flush=on|off]\n"
637    "          [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
638    "          [,driver specific parameters...]\n"
639    "                configure a block backend\n", QEMU_ARCH_ALL)
640STEXI
641@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
642@findex -blockdev
643
644Define a new block driver node. Some of the options apply to all block drivers,
645other options are only accepted for a specific block driver. See below for a
646list of generic options and options for the most common block drivers.
647
648Options that expect a reference to another node (e.g. @code{file}) can be
649given in two ways. Either you specify the node name of an already existing node
650(file=@var{node-name}), or you define a new node inline, adding options
651for the referenced node after a dot (file.filename=@var{path},file.aio=native).
652
653A block driver node created with @option{-blockdev} can be used for a guest
654device by specifying its node name for the @code{drive} property in a
655@option{-device} argument that defines a block device.
656
657@table @option
658@item Valid options for any block driver node:
659
660@table @code
661@item driver
662Specifies the block driver to use for the given node.
663@item node-name
664This defines the name of the block driver node by which it will be referenced
665later. The name must be unique, i.e. it must not match the name of a different
666block driver node, or (if you use @option{-drive} as well) the ID of a drive.
667
668If no node name is specified, it is automatically generated. The generated node
669name is not intended to be predictable and changes between QEMU invocations.
670For the top level, an explicit node name must be specified.
671@item read-only
672Open the node read-only. Guest write attempts will fail.
673@item cache.direct
674The host page cache can be avoided with @option{cache.direct=on}. This will
675attempt to do disk IO directly to the guest's memory. QEMU may still perform an
676internal copy of the data.
677@item cache.no-flush
678In case you don't care about data integrity over host failures, you can use
679@option{cache.no-flush=on}. This option tells QEMU that it never needs to write
680any data to the disk but can instead keep things in cache. If anything goes
681wrong, like your host losing power, the disk storage getting disconnected
682accidentally, etc. your image will most probably be rendered unusable.
683@item discard=@var{discard}
684@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls
685whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
686ignored or passed to the filesystem. Some machine types may not support
687discard requests.
688@item detect-zeroes=@var{detect-zeroes}
689@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
690conversion of plain zero writes by the OS to driver specific optimized
691zero write commands. You may even choose "unmap" if @var{discard} is set
692to "unmap" to allow a zero write to be converted to an @code{unmap} operation.
693@end table
694
695@item Driver-specific options for @code{file}
696
697This is the protocol-level block driver for accessing regular files.
698
699@table @code
700@item filename
701The path to the image file in the local filesystem
702@item aio
703Specifies the AIO backend (threads/native, default: threads)
704@item locking
705Specifies whether the image file is protected with Linux OFD / POSIX locks. The
706default is to use the Linux Open File Descriptor API if available, otherwise no
707lock is applied.  (auto/on/off, default: auto)
708@end table
709Example:
710@example
711-blockdev driver=file,node-name=disk,filename=disk.img
712@end example
713
714@item Driver-specific options for @code{raw}
715
716This is the image format block driver for raw 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@end table
724Example 1:
725@example
726-blockdev driver=file,node-name=disk_file,filename=disk.img
727-blockdev driver=raw,node-name=disk,file=disk_file
728@end example
729Example 2:
730@example
731-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
732@end example
733
734@item Driver-specific options for @code{qcow2}
735
736This is the image format block driver for qcow2 images. It is usually
737stacked on top of a protocol level block driver such as @code{file}.
738
739@table @code
740@item file
741Reference to or definition of the data source block driver node
742(e.g. a @code{file} driver node)
743
744@item backing
745Reference to or definition of the backing file block device (default is taken
746from the image file). It is allowed to pass @code{null} here in order to disable
747the default backing file.
748
749@item lazy-refcounts
750Whether to enable the lazy refcounts feature (on/off; default is taken from the
751image file)
752
753@item cache-size
754The maximum total size of the L2 table and refcount block caches in bytes
755(default: 1048576 bytes or 8 clusters, whichever is larger)
756
757@item l2-cache-size
758The maximum size of the L2 table cache in bytes
759(default: 4/5 of the total cache size)
760
761@item refcount-cache-size
762The maximum size of the refcount block cache in bytes
763(default: 1/5 of the total cache size)
764
765@item cache-clean-interval
766Clean unused entries in the L2 and refcount caches. The interval is in seconds.
767The default value is 0 and it disables this feature.
768
769@item pass-discard-request
770Whether discard requests to the qcow2 device should be forwarded to the data
771source (on/off; default: on if discard=unmap is specified, off otherwise)
772
773@item pass-discard-snapshot
774Whether discard requests for the data source should be issued when a snapshot
775operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
776default: on)
777
778@item pass-discard-other
779Whether discard requests for the data source should be issued on other
780occasions where a cluster gets freed (on/off; default: off)
781
782@item overlap-check
783Which overlap checks to perform for writes to the image
784(none/constant/cached/all; default: cached). For details or finer
785granularity control refer to the QAPI documentation of @code{blockdev-add}.
786@end table
787
788Example 1:
789@example
790-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
791-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
792@end example
793Example 2:
794@example
795-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
796@end example
797
798@item Driver-specific options for other drivers
799Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
800
801@end table
802
803ETEXI
804
805DEF("drive", HAS_ARG, QEMU_OPTION_drive,
806    "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
807    "       [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
808    "       [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
809    "       [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
810    "       [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
811    "       [,readonly=on|off][,copy-on-read=on|off]\n"
812    "       [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
813    "       [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
814    "       [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
815    "       [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
816    "       [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
817    "       [[,iops_size=is]]\n"
818    "       [[,group=g]]\n"
819    "                use 'file' as a drive image\n", QEMU_ARCH_ALL)
820STEXI
821@item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
822@findex -drive
823
824Define a new drive. This includes creating a block driver node (the backend) as
825well as a guest device, and is mostly a shortcut for defining the corresponding
826@option{-blockdev} and @option{-device} options.
827
828@option{-drive} accepts all options that are accepted by @option{-blockdev}. In
829addition, it knows the following options:
830
831@table @option
832@item file=@var{file}
833This option defines which disk image (@pxref{disk_images}) to use with
834this drive. If the filename contains comma, you must double it
835(for instance, "file=my,,file" to use file "my,file").
836
837Special files such as iSCSI devices can be specified using protocol
838specific URLs. See the section for "Device URL Syntax" for more information.
839@item if=@var{interface}
840This option defines on which type on interface the drive is connected.
841Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
842@item bus=@var{bus},unit=@var{unit}
843These options define where is connected the drive by defining the bus number and
844the unit id.
845@item index=@var{index}
846This option defines where is connected the drive by using an index in the list
847of available connectors of a given interface type.
848@item media=@var{media}
849This option defines the type of the media: disk or cdrom.
850@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
851Force disk physical geometry and the optional BIOS translation (trans=none or
852lba). These parameters are deprecated, use the corresponding parameters
853of @code{-device} instead.
854@item snapshot=@var{snapshot}
855@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
856(see @option{-snapshot}).
857@item cache=@var{cache}
858@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
859and controls how the host cache is used to access block data. This is a
860shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
861options (as in @option{-blockdev}), and additionally @option{cache.writeback},
862which provides a default for the @option{write-cache} option of block guest
863devices (as in @option{-device}). The modes correspond to the following
864settings:
865
866@c Our texi2pod.pl script doesn't support @multitable, so fall back to using
867@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
868@c and the HTML output.
869@example
870@             │ cache.writeback   cache.direct   cache.no-flush
871─────────────┼─────────────────────────────────────────────────
872writeback    │ on                off            off
873none         │ on                on             off
874writethrough │ off               off            off
875directsync   │ off               on             off
876unsafe       │ on                off            on
877@end example
878
879The default mode is @option{cache=writeback}.
880
881@item aio=@var{aio}
882@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
883@item format=@var{format}
884Specify which disk @var{format} will be used rather than detecting
885the format.  Can be used to specify format=raw to avoid interpreting
886an untrusted format header.
887@item serial=@var{serial}
888This option specifies the serial number to assign to the device. This
889parameter is deprecated, use the corresponding parameter of @code{-device}
890instead.
891@item addr=@var{addr}
892Specify the controller's PCI address (if=virtio only). This parameter is
893deprecated, use the corresponding parameter of @code{-device} instead.
894@item werror=@var{action},rerror=@var{action}
895Specify which @var{action} to take on write and read errors. Valid actions are:
896"ignore" (ignore the error and try to continue), "stop" (pause QEMU),
897"report" (report the error to the guest), "enospc" (pause QEMU only if the
898host disk is full; report the error to the guest otherwise).
899The default setting is @option{werror=enospc} and @option{rerror=report}.
900@item copy-on-read=@var{copy-on-read}
901@var{copy-on-read} is "on" or "off" and enables whether to copy read backing
902file sectors into the image file.
903@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
904Specify bandwidth throttling limits in bytes per second, either for all request
905types or for reads or writes only.  Small values can lead to timeouts or hangs
906inside the guest.  A safe minimum for disks is 2 MB/s.
907@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
908Specify bursts in bytes per second, either for all request types or for reads
909or writes only.  Bursts allow the guest I/O to spike above the limit
910temporarily.
911@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
912Specify request rate limits in requests per second, either for all request
913types or for reads or writes only.
914@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
915Specify bursts in requests per second, either for all request types or for reads
916or writes only.  Bursts allow the guest I/O to spike above the limit
917temporarily.
918@item iops_size=@var{is}
919Let every @var{is} bytes of a request count as a new request for iops
920throttling purposes.  Use this option to prevent guests from circumventing iops
921limits by sending fewer but larger requests.
922@item group=@var{g}
923Join a throttling quota group with given name @var{g}.  All drives that are
924members of the same group are accounted for together.  Use this option to
925prevent guests from circumventing throttling limits by using many small disks
926instead of a single larger disk.
927@end table
928
929By default, the @option{cache.writeback=on} mode is used. It will report data
930writes as completed as soon as the data is present in the host page cache.
931This is safe as long as your guest OS makes sure to correctly flush disk caches
932where needed. If your guest OS does not handle volatile disk write caches
933correctly and your host crashes or loses power, then the guest may experience
934data corruption.
935
936For such guests, you should consider using @option{cache.writeback=off}. This
937means that the host page cache will be used to read and write data, but write
938notification will be sent to the guest only after QEMU has made sure to flush
939each write to the disk. Be aware that this has a major impact on performance.
940
941When using the @option{-snapshot} option, unsafe caching is always used.
942
943Copy-on-read avoids accessing the same backing file sectors repeatedly and is
944useful when the backing file is over a slow network.  By default copy-on-read
945is off.
946
947Instead of @option{-cdrom} you can use:
948@example
949qemu-system-i386 -drive file=file,index=2,media=cdrom
950@end example
951
952Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
953use:
954@example
955qemu-system-i386 -drive file=file,index=0,media=disk
956qemu-system-i386 -drive file=file,index=1,media=disk
957qemu-system-i386 -drive file=file,index=2,media=disk
958qemu-system-i386 -drive file=file,index=3,media=disk
959@end example
960
961You can open an image using pre-opened file descriptors from an fd set:
962@example
963qemu-system-i386
964-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
965-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
966-drive file=/dev/fdset/2,index=0,media=disk
967@end example
968
969You can connect a CDROM to the slave of ide0:
970@example
971qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
972@end example
973
974If you don't specify the "file=" argument, you define an empty drive:
975@example
976qemu-system-i386 -drive if=ide,index=1,media=cdrom
977@end example
978
979Instead of @option{-fda}, @option{-fdb}, you can use:
980@example
981qemu-system-i386 -drive file=file,index=0,if=floppy
982qemu-system-i386 -drive file=file,index=1,if=floppy
983@end example
984
985By default, @var{interface} is "ide" and @var{index} is automatically
986incremented:
987@example
988qemu-system-i386 -drive file=a -drive file=b"
989@end example
990is interpreted like:
991@example
992qemu-system-i386 -hda a -hdb b
993@end example
994ETEXI
995
996DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
997    "-mtdblock file  use 'file' as on-board Flash memory image\n",
998    QEMU_ARCH_ALL)
999STEXI
1000@item -mtdblock @var{file}
1001@findex -mtdblock
1002Use @var{file} as on-board Flash memory image.
1003ETEXI
1004
1005DEF("sd", HAS_ARG, QEMU_OPTION_sd,
1006    "-sd file        use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
1007STEXI
1008@item -sd @var{file}
1009@findex -sd
1010Use @var{file} as SecureDigital card image.
1011ETEXI
1012
1013DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
1014    "-pflash file    use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
1015STEXI
1016@item -pflash @var{file}
1017@findex -pflash
1018Use @var{file} as a parallel flash image.
1019ETEXI
1020
1021DEF("snapshot", 0, QEMU_OPTION_snapshot,
1022    "-snapshot       write to temporary files instead of disk image files\n",
1023    QEMU_ARCH_ALL)
1024STEXI
1025@item -snapshot
1026@findex -snapshot
1027Write to temporary files instead of disk image files. In this case,
1028the raw disk image you use is not written back. You can however force
1029the write back by pressing @key{C-a s} (@pxref{disk_images}).
1030ETEXI
1031
1032DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
1033    "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1034    " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1035    " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1036    " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1037    " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1038    " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1039    " [[,throttling.iops-size=is]]\n",
1040    QEMU_ARCH_ALL)
1041
1042STEXI
1043
1044@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}]
1045@findex -fsdev
1046Define a new file system device. Valid options are:
1047@table @option
1048@item @var{fsdriver}
1049This option specifies the fs driver backend to use.
1050Currently "local", "handle" and "proxy" file system drivers are supported.
1051@item id=@var{id}
1052Specifies identifier for this device
1053@item path=@var{path}
1054Specifies the export path for the file system device. Files under
1055this path will be available to the 9p client on the guest.
1056@item security_model=@var{security_model}
1057Specifies the security model to be used for this export path.
1058Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1059In "passthrough" security model, files are stored using the same
1060credentials as they are created on the guest. This requires QEMU
1061to run as root. In "mapped-xattr" security model, some of the file
1062attributes like uid, gid, mode bits and link target are stored as
1063file attributes. For "mapped-file" these attributes are stored in the
1064hidden .virtfs_metadata directory. Directories exported by this security model cannot
1065interact with other unix tools. "none" security model is same as
1066passthrough except the sever won't report failures if it fails to
1067set file attributes like ownership. Security model is mandatory
1068only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
1069security model as a parameter.
1070@item writeout=@var{writeout}
1071This is an optional argument. The only supported value is "immediate".
1072This means that host page cache will be used to read and write data but
1073write notification will be sent to the guest only when the data has been
1074reported as written by the storage subsystem.
1075@item readonly
1076Enables exporting 9p share as a readonly mount for guests. By default
1077read-write access is given.
1078@item socket=@var{socket}
1079Enables proxy filesystem driver to use passed socket file for communicating
1080with virtfs-proxy-helper
1081@item sock_fd=@var{sock_fd}
1082Enables proxy filesystem driver to use passed socket descriptor for
1083communicating with virtfs-proxy-helper. Usually a helper like libvirt
1084will create socketpair and pass one of the fds as sock_fd
1085@item fmode=@var{fmode}
1086Specifies the default mode for newly created files on the host. Works only
1087with security models "mapped-xattr" and "mapped-file".
1088@item dmode=@var{dmode}
1089Specifies the default mode for newly created directories on the host. Works
1090only with security models "mapped-xattr" and "mapped-file".
1091@end table
1092
1093-fsdev option is used along with -device driver "virtio-9p-pci".
1094@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
1095Options for virtio-9p-pci driver are:
1096@table @option
1097@item fsdev=@var{id}
1098Specifies the id value specified along with -fsdev option
1099@item mount_tag=@var{mount_tag}
1100Specifies the tag name to be used by the guest to mount this export point
1101@end table
1102
1103ETEXI
1104
1105DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
1106    "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1107    "        [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1108    QEMU_ARCH_ALL)
1109
1110STEXI
1111
1112@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}]
1113@findex -virtfs
1114
1115The general form of a Virtual File system pass-through options are:
1116@table @option
1117@item @var{fsdriver}
1118This option specifies the fs driver backend to use.
1119Currently "local", "handle" and "proxy" file system drivers are supported.
1120@item id=@var{id}
1121Specifies identifier for this device
1122@item path=@var{path}
1123Specifies the export path for the file system device. Files under
1124this path will be available to the 9p client on the guest.
1125@item security_model=@var{security_model}
1126Specifies the security model to be used for this export path.
1127Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1128In "passthrough" security model, files are stored using the same
1129credentials as they are created on the guest. This requires QEMU
1130to run as root. In "mapped-xattr" security model, some of the file
1131attributes like uid, gid, mode bits and link target are stored as
1132file attributes. For "mapped-file" these attributes are stored in the
1133hidden .virtfs_metadata directory. Directories exported by this security model cannot
1134interact with other unix tools. "none" security model is same as
1135passthrough except the sever won't report failures if it fails to
1136set file attributes like ownership. Security model is mandatory only
1137for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
1138model as a parameter.
1139@item writeout=@var{writeout}
1140This is an optional argument. The only supported value is "immediate".
1141This means that host page cache will be used to read and write data but
1142write notification will be sent to the guest only when the data has been
1143reported as written by the storage subsystem.
1144@item readonly
1145Enables exporting 9p share as a readonly mount for guests. By default
1146read-write access is given.
1147@item socket=@var{socket}
1148Enables proxy filesystem driver to use passed socket file for
1149communicating with virtfs-proxy-helper. Usually a helper like libvirt
1150will create socketpair and pass one of the fds as sock_fd
1151@item sock_fd
1152Enables proxy filesystem driver to use passed 'sock_fd' as the socket
1153descriptor for interfacing with virtfs-proxy-helper
1154@item fmode=@var{fmode}
1155Specifies the default mode for newly created files on the host. Works only
1156with security models "mapped-xattr" and "mapped-file".
1157@item dmode=@var{dmode}
1158Specifies the default mode for newly created directories on the host. Works
1159only with security models "mapped-xattr" and "mapped-file".
1160@end table
1161ETEXI
1162
1163DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
1164    "-virtfs_synth Create synthetic file system image\n",
1165    QEMU_ARCH_ALL)
1166STEXI
1167@item -virtfs_synth
1168@findex -virtfs_synth
1169Create synthetic file system image
1170ETEXI
1171
1172DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1173    "-iscsi [user=user][,password=password]\n"
1174    "       [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1175    "       [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1176    "       [,timeout=timeout]\n"
1177    "                iSCSI session parameters\n", QEMU_ARCH_ALL)
1178
1179STEXI
1180@item -iscsi
1181@findex -iscsi
1182Configure iSCSI session parameters.
1183ETEXI
1184
1185STEXI
1186@end table
1187ETEXI
1188DEFHEADING()
1189
1190DEFHEADING(USB options:)
1191STEXI
1192@table @option
1193ETEXI
1194
1195DEF("usb", 0, QEMU_OPTION_usb,
1196    "-usb            enable the USB driver (if it is not used by default yet)\n",
1197    QEMU_ARCH_ALL)
1198STEXI
1199@item -usb
1200@findex -usb
1201Enable the USB driver (if it is not used by default yet).
1202ETEXI
1203
1204DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1205    "-usbdevice name add the host or guest USB device 'name'\n",
1206    QEMU_ARCH_ALL)
1207STEXI
1208
1209@item -usbdevice @var{devname}
1210@findex -usbdevice
1211Add the USB device @var{devname}. Note that this option is deprecated,
1212please use @code{-device usb-...} instead. @xref{usb_devices}.
1213
1214@table @option
1215
1216@item mouse
1217Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1218
1219@item tablet
1220Pointer device that uses absolute coordinates (like a touchscreen). This
1221means QEMU is able to report the mouse position without having to grab the
1222mouse. Also overrides the PS/2 mouse emulation when activated.
1223
1224@item braille
1225Braille device.  This will use BrlAPI to display the braille output on a real
1226or fake device.
1227
1228@end table
1229ETEXI
1230
1231STEXI
1232@end table
1233ETEXI
1234DEFHEADING()
1235
1236DEFHEADING(Display options:)
1237STEXI
1238@table @option
1239ETEXI
1240
1241DEF("display", HAS_ARG, QEMU_OPTION_display,
1242    "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1243    "            [,window_close=on|off][,gl=on|core|es|off]\n"
1244    "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1245    "-display vnc=<display>[,<optargs>]\n"
1246    "-display curses\n"
1247    "-display none"
1248    "                select display type\n"
1249    "The default display is equivalent to\n"
1250#if defined(CONFIG_GTK)
1251            "\t\"-display gtk\"\n"
1252#elif defined(CONFIG_SDL)
1253            "\t\"-display sdl\"\n"
1254#elif defined(CONFIG_COCOA)
1255            "\t\"-display cocoa\"\n"
1256#elif defined(CONFIG_VNC)
1257            "\t\"-vnc localhost:0,to=99,id=default\"\n"
1258#else
1259            "\t\"-display none\"\n"
1260#endif
1261    , QEMU_ARCH_ALL)
1262STEXI
1263@item -display @var{type}
1264@findex -display
1265Select type of display to use. This option is a replacement for the
1266old style -sdl/-curses/... options. Valid values for @var{type} are
1267@table @option
1268@item sdl
1269Display video output via SDL (usually in a separate graphics
1270window; see the SDL documentation for other possibilities).
1271@item curses
1272Display video output via curses. For graphics device models which
1273support a text mode, QEMU can display this output using a
1274curses/ncurses interface. Nothing is displayed when the graphics
1275device is in graphical mode or if the graphics device does not support
1276a text mode. Generally only the VGA device models support text mode.
1277@item none
1278Do not display video output. The guest will still see an emulated
1279graphics card, but its output will not be displayed to the QEMU
1280user. This option differs from the -nographic option in that it
1281only affects what is done with video output; -nographic also changes
1282the destination of the serial and parallel port data.
1283@item gtk
1284Display video output in a GTK window. This interface provides drop-down
1285menus and other UI elements to configure and control the VM during
1286runtime.
1287@item vnc
1288Start a VNC server on display <arg>
1289@end table
1290ETEXI
1291
1292DEF("nographic", 0, QEMU_OPTION_nographic,
1293    "-nographic      disable graphical output and redirect serial I/Os to console\n",
1294    QEMU_ARCH_ALL)
1295STEXI
1296@item -nographic
1297@findex -nographic
1298Normally, if QEMU is compiled with graphical window support, it displays
1299output such as guest graphics, guest console, and the QEMU monitor in a
1300window. With this option, you can totally disable graphical output so
1301that QEMU is a simple command line application. The emulated serial port
1302is redirected on the console and muxed with the monitor (unless
1303redirected elsewhere explicitly). Therefore, you can still use QEMU to
1304debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1305switching between the console and monitor.
1306ETEXI
1307
1308DEF("curses", 0, QEMU_OPTION_curses,
1309    "-curses         shorthand for -display curses\n",
1310    QEMU_ARCH_ALL)
1311STEXI
1312@item -curses
1313@findex -curses
1314Normally, if QEMU is compiled with graphical window support, it displays
1315output such as guest graphics, guest console, and the QEMU monitor in a
1316window. With this option, QEMU can display the VGA output when in text
1317mode using a curses/ncurses interface. Nothing is displayed in graphical
1318mode.
1319ETEXI
1320
1321DEF("no-frame", 0, QEMU_OPTION_no_frame,
1322    "-no-frame       open SDL window without a frame and window decorations\n",
1323    QEMU_ARCH_ALL)
1324STEXI
1325@item -no-frame
1326@findex -no-frame
1327Do not use decorations for SDL windows and start them using the whole
1328available screen space. This makes the using QEMU in a dedicated desktop
1329workspace more convenient.
1330ETEXI
1331
1332DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1333    "-alt-grab       use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1334    QEMU_ARCH_ALL)
1335STEXI
1336@item -alt-grab
1337@findex -alt-grab
1338Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1339affects the special keys (for fullscreen, monitor-mode switching, etc).
1340ETEXI
1341
1342DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1343    "-ctrl-grab      use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1344    QEMU_ARCH_ALL)
1345STEXI
1346@item -ctrl-grab
1347@findex -ctrl-grab
1348Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1349affects the special keys (for fullscreen, monitor-mode switching, etc).
1350ETEXI
1351
1352DEF("no-quit", 0, QEMU_OPTION_no_quit,
1353    "-no-quit        disable SDL window close capability\n", QEMU_ARCH_ALL)
1354STEXI
1355@item -no-quit
1356@findex -no-quit
1357Disable SDL window close capability.
1358ETEXI
1359
1360DEF("sdl", 0, QEMU_OPTION_sdl,
1361    "-sdl            shorthand for -display sdl\n", QEMU_ARCH_ALL)
1362STEXI
1363@item -sdl
1364@findex -sdl
1365Enable SDL.
1366ETEXI
1367
1368DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1369    "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1370    "       [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1371    "       [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1372    "       [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1373    "       [,tls-ciphers=<list>]\n"
1374    "       [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1375    "       [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1376    "       [,sasl][,password=<secret>][,disable-ticketing]\n"
1377    "       [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1378    "       [,jpeg-wan-compression=[auto|never|always]]\n"
1379    "       [,zlib-glz-wan-compression=[auto|never|always]]\n"
1380    "       [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1381    "       [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1382    "       [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1383    "       [,gl=[on|off]][,rendernode=<file>]\n"
1384    "   enable spice\n"
1385    "   at least one of {port, tls-port} is mandatory\n",
1386    QEMU_ARCH_ALL)
1387STEXI
1388@item -spice @var{option}[,@var{option}[,...]]
1389@findex -spice
1390Enable the spice remote desktop protocol. Valid options are
1391
1392@table @option
1393
1394@item port=<nr>
1395Set the TCP port spice is listening on for plaintext channels.
1396
1397@item addr=<addr>
1398Set the IP address spice is listening on.  Default is any address.
1399
1400@item ipv4
1401@itemx ipv6
1402@itemx unix
1403Force using the specified IP version.
1404
1405@item password=<secret>
1406Set the password you need to authenticate.
1407
1408@item sasl
1409Require that the client use SASL to authenticate with the spice.
1410The exact choice of authentication method used is controlled from the
1411system / user's SASL configuration file for the 'qemu' service. This
1412is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1413unprivileged user, an environment variable SASL_CONF_PATH can be used
1414to make it search alternate locations for the service config.
1415While some SASL auth methods can also provide data encryption (eg GSSAPI),
1416it is recommended that SASL always be combined with the 'tls' and
1417'x509' settings to enable use of SSL and server certificates. This
1418ensures a data encryption preventing compromise of authentication
1419credentials.
1420
1421@item disable-ticketing
1422Allow client connects without authentication.
1423
1424@item disable-copy-paste
1425Disable copy paste between the client and the guest.
1426
1427@item disable-agent-file-xfer
1428Disable spice-vdagent based file-xfer between the client and the guest.
1429
1430@item tls-port=<nr>
1431Set the TCP port spice is listening on for encrypted channels.
1432
1433@item x509-dir=<dir>
1434Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1435
1436@item x509-key-file=<file>
1437@itemx x509-key-password=<file>
1438@itemx x509-cert-file=<file>
1439@itemx x509-cacert-file=<file>
1440@itemx x509-dh-key-file=<file>
1441The x509 file names can also be configured individually.
1442
1443@item tls-ciphers=<list>
1444Specify which ciphers to use.
1445
1446@item tls-channel=[main|display|cursor|inputs|record|playback]
1447@itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1448Force specific channel to be used with or without TLS encryption.  The
1449options can be specified multiple times to configure multiple
1450channels.  The special name "default" can be used to set the default
1451mode.  For channels which are not explicitly forced into one mode the
1452spice client is allowed to pick tls/plaintext as he pleases.
1453
1454@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1455Configure image compression (lossless).
1456Default is auto_glz.
1457
1458@item jpeg-wan-compression=[auto|never|always]
1459@itemx zlib-glz-wan-compression=[auto|never|always]
1460Configure wan image compression (lossy for slow links).
1461Default is auto.
1462
1463@item streaming-video=[off|all|filter]
1464Configure video stream detection.  Default is off.
1465
1466@item agent-mouse=[on|off]
1467Enable/disable passing mouse events via vdagent.  Default is on.
1468
1469@item playback-compression=[on|off]
1470Enable/disable audio stream compression (using celt 0.5.1).  Default is on.
1471
1472@item seamless-migration=[on|off]
1473Enable/disable spice seamless migration. Default is off.
1474
1475@item gl=[on|off]
1476Enable/disable OpenGL context. Default is off.
1477
1478@item rendernode=<file>
1479DRM render node for OpenGL rendering. If not specified, it will pick
1480the first available. (Since 2.9)
1481
1482@end table
1483ETEXI
1484
1485DEF("portrait", 0, QEMU_OPTION_portrait,
1486    "-portrait       rotate graphical output 90 deg left (only PXA LCD)\n",
1487    QEMU_ARCH_ALL)
1488STEXI
1489@item -portrait
1490@findex -portrait
1491Rotate graphical output 90 deg left (only PXA LCD).
1492ETEXI
1493
1494DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1495    "-rotate <deg>   rotate graphical output some deg left (only PXA LCD)\n",
1496    QEMU_ARCH_ALL)
1497STEXI
1498@item -rotate @var{deg}
1499@findex -rotate
1500Rotate graphical output some deg left (only PXA LCD).
1501ETEXI
1502
1503DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1504    "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1505    "                select video card type\n", QEMU_ARCH_ALL)
1506STEXI
1507@item -vga @var{type}
1508@findex -vga
1509Select type of VGA card to emulate. Valid values for @var{type} are
1510@table @option
1511@item cirrus
1512Cirrus Logic GD5446 Video card. All Windows versions starting from
1513Windows 95 should recognize and use this graphic card. For optimal
1514performances, use 16 bit color depth in the guest and the host OS.
1515(This card was the default before QEMU 2.2)
1516@item std
1517Standard VGA card with Bochs VBE extensions.  If your guest OS
1518supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1519to use high resolution modes (>= 1280x1024x16) then you should use
1520this option. (This card is the default since QEMU 2.2)
1521@item vmware
1522VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1523recent XFree86/XOrg server or Windows guest with a driver for this
1524card.
1525@item qxl
1526QXL paravirtual graphic card.  It is VGA compatible (including VESA
15272.0 VBE support).  Works best with qxl guest drivers installed though.
1528Recommended choice when using the spice protocol.
1529@item tcx
1530(sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1531sun4m machines and offers both 8-bit and 24-bit colour depths at a
1532fixed resolution of 1024x768.
1533@item cg3
1534(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1535for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1536resolutions aimed at people wishing to run older Solaris versions.
1537@item virtio
1538Virtio VGA card.
1539@item none
1540Disable VGA card.
1541@end table
1542ETEXI
1543
1544DEF("full-screen", 0, QEMU_OPTION_full_screen,
1545    "-full-screen    start in full screen\n", QEMU_ARCH_ALL)
1546STEXI
1547@item -full-screen
1548@findex -full-screen
1549Start in full screen.
1550ETEXI
1551
1552DEF("g", 1, QEMU_OPTION_g ,
1553    "-g WxH[xDEPTH]  Set the initial graphical resolution and depth\n",
1554    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1555STEXI
1556@item -g @var{width}x@var{height}[x@var{depth}]
1557@findex -g
1558Set the initial graphical resolution and depth (PPC, SPARC only).
1559ETEXI
1560
1561DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1562    "-vnc <display>  shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1563STEXI
1564@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1565@findex -vnc
1566Normally, if QEMU is compiled with graphical window support, it displays
1567output such as guest graphics, guest console, and the QEMU monitor in a
1568window. With this option, you can have QEMU listen on VNC display
1569@var{display} and redirect the VGA display over the VNC session. It is
1570very useful to enable the usb tablet device when using this option
1571(option @option{-device usb-tablet}). When using the VNC display, you
1572must use the @option{-k} parameter to set the keyboard layout if you are
1573not using en-us. Valid syntax for the @var{display} is
1574
1575@table @option
1576
1577@item to=@var{L}
1578
1579With this option, QEMU will try next available VNC @var{display}s, until the
1580number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1581available, e.g. port 5900+@var{display} is already used by another
1582application. By default, to=0.
1583
1584@item @var{host}:@var{d}
1585
1586TCP connections will only be allowed from @var{host} on display @var{d}.
1587By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1588be omitted in which case the server will accept connections from any host.
1589
1590@item unix:@var{path}
1591
1592Connections will be allowed over UNIX domain sockets where @var{path} is the
1593location of a unix socket to listen for connections on.
1594
1595@item none
1596
1597VNC is initialized but not started. The monitor @code{change} command
1598can be used to later start the VNC server.
1599
1600@end table
1601
1602Following the @var{display} value there may be one or more @var{option} flags
1603separated by commas. Valid options are
1604
1605@table @option
1606
1607@item reverse
1608
1609Connect to a listening VNC client via a ``reverse'' connection. The
1610client is specified by the @var{display}. For reverse network
1611connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1612is a TCP port number, not a display number.
1613
1614@item websocket
1615
1616Opens an additional TCP listening port dedicated to VNC Websocket connections.
1617If a bare @var{websocket} option is given, the Websocket port is
16185700+@var{display}. An alternative port can be specified with the
1619syntax @code{websocket}=@var{port}.
1620
1621If @var{host} is specified connections will only be allowed from this host.
1622It is possible to control the websocket listen address independently, using
1623the syntax @code{websocket}=@var{host}:@var{port}.
1624
1625If no TLS credentials are provided, the websocket connection runs in
1626unencrypted mode. If TLS credentials are provided, the websocket connection
1627requires encrypted client connections.
1628
1629@item password
1630
1631Require that password based authentication is used for client connections.
1632
1633The password must be set separately using the @code{set_password} command in
1634the @ref{pcsys_monitor}. The syntax to change your password is:
1635@code{set_password <protocol> <password>} where <protocol> could be either
1636"vnc" or "spice".
1637
1638If you would like to change <protocol> password expiration, you should use
1639@code{expire_password <protocol> <expiration-time>} where expiration time could
1640be one of the following options: now, never, +seconds or UNIX time of
1641expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1642to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1643date and time).
1644
1645You can also use keywords "now" or "never" for the expiration time to
1646allow <protocol> password to expire immediately or never expire.
1647
1648@item tls-creds=@var{ID}
1649
1650Provides the ID of a set of TLS credentials to use to secure the
1651VNC server. They will apply to both the normal VNC server socket
1652and the websocket socket (if enabled). Setting TLS credentials
1653will cause the VNC server socket to enable the VeNCrypt auth
1654mechanism.  The credentials should have been previously created
1655using the @option{-object tls-creds} argument.
1656
1657The @option{tls-creds} parameter obsoletes the @option{tls},
1658@option{x509}, and @option{x509verify} options, and as such
1659it is not permitted to set both new and old type options at
1660the same time.
1661
1662@item tls
1663
1664Require that client use TLS when communicating with the VNC server. This
1665uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1666attack. It is recommended that this option be combined with either the
1667@option{x509} or @option{x509verify} options.
1668
1669This option is now deprecated in favor of using the @option{tls-creds}
1670argument.
1671
1672@item x509=@var{/path/to/certificate/dir}
1673
1674Valid if @option{tls} is specified. Require that x509 credentials are used
1675for negotiating the TLS session. The server will send its x509 certificate
1676to the client. It is recommended that a password be set on the VNC server
1677to provide authentication of the client when this is used. The path following
1678this option specifies where the x509 certificates are to be loaded from.
1679See the @ref{vnc_security} section for details on generating certificates.
1680
1681This option is now deprecated in favour of using the @option{tls-creds}
1682argument.
1683
1684@item x509verify=@var{/path/to/certificate/dir}
1685
1686Valid if @option{tls} is specified. Require that x509 credentials are used
1687for negotiating the TLS session. The server will send its x509 certificate
1688to the client, and request that the client send its own x509 certificate.
1689The server will validate the client's certificate against the CA certificate,
1690and reject clients when validation fails. If the certificate authority is
1691trusted, this is a sufficient authentication mechanism. You may still wish
1692to set a password on the VNC server as a second authentication layer. The
1693path following this option specifies where the x509 certificates are to
1694be loaded from. See the @ref{vnc_security} section for details on generating
1695certificates.
1696
1697This option is now deprecated in favour of using the @option{tls-creds}
1698argument.
1699
1700@item sasl
1701
1702Require that the client use SASL to authenticate with the VNC server.
1703The exact choice of authentication method used is controlled from the
1704system / user's SASL configuration file for the 'qemu' service. This
1705is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1706unprivileged user, an environment variable SASL_CONF_PATH can be used
1707to make it search alternate locations for the service config.
1708While some SASL auth methods can also provide data encryption (eg GSSAPI),
1709it is recommended that SASL always be combined with the 'tls' and
1710'x509' settings to enable use of SSL and server certificates. This
1711ensures a data encryption preventing compromise of authentication
1712credentials. See the @ref{vnc_security} section for details on using
1713SASL authentication.
1714
1715@item acl
1716
1717Turn on access control lists for checking of the x509 client certificate
1718and SASL party. For x509 certs, the ACL check is made against the
1719certificate's distinguished name. This is something that looks like
1720@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1721made against the username, which depending on the SASL plugin, may
1722include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1723When the @option{acl} flag is set, the initial access list will be
1724empty, with a @code{deny} policy. Thus no one will be allowed to
1725use the VNC server until the ACLs have been loaded. This can be
1726achieved using the @code{acl} monitor command.
1727
1728@item lossy
1729
1730Enable lossy compression methods (gradient, JPEG, ...). If this
1731option is set, VNC client may receive lossy framebuffer updates
1732depending on its encoding settings. Enabling this option can save
1733a lot of bandwidth at the expense of quality.
1734
1735@item non-adaptive
1736
1737Disable adaptive encodings. Adaptive encodings are enabled by default.
1738An adaptive encoding will try to detect frequently updated screen regions,
1739and send updates in these regions using a lossy encoding (like JPEG).
1740This can be really helpful to save bandwidth when playing videos. Disabling
1741adaptive encodings restores the original static behavior of encodings
1742like Tight.
1743
1744@item share=[allow-exclusive|force-shared|ignore]
1745
1746Set display sharing policy.  'allow-exclusive' allows clients to ask
1747for exclusive access.  As suggested by the rfb spec this is
1748implemented by dropping other connections.  Connecting multiple
1749clients in parallel requires all clients asking for a shared session
1750(vncviewer: -shared switch).  This is the default.  'force-shared'
1751disables exclusive client access.  Useful for shared desktop sessions,
1752where you don't want someone forgetting specify -shared disconnect
1753everybody else.  'ignore' completely ignores the shared flag and
1754allows everybody connect unconditionally.  Doesn't conform to the rfb
1755spec but is traditional QEMU behavior.
1756
1757@item key-delay-ms
1758
1759Set keyboard delay, for key down and key up events, in milliseconds.
1760Default is 10.  Keyboards are low-bandwidth devices, so this slowdown
1761can help the device and guest to keep up and not lose events in case
1762events are arriving in bulk.  Possible causes for the latter are flaky
1763network connections, or scripts for automated testing.
1764
1765@end table
1766ETEXI
1767
1768STEXI
1769@end table
1770ETEXI
1771ARCHHEADING(, QEMU_ARCH_I386)
1772
1773ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1774STEXI
1775@table @option
1776ETEXI
1777
1778DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1779    "-win2k-hack     use it when installing Windows 2000 to avoid a disk full bug\n",
1780    QEMU_ARCH_I386)
1781STEXI
1782@item -win2k-hack
1783@findex -win2k-hack
1784Use it when installing Windows 2000 to avoid a disk full bug. After
1785Windows 2000 is installed, you no longer need this option (this option
1786slows down the IDE transfers).
1787ETEXI
1788
1789HXCOMM Deprecated by -rtc
1790DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1791
1792DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1793    "-no-fd-bootchk  disable boot signature checking for floppy disks\n",
1794    QEMU_ARCH_I386)
1795STEXI
1796@item -no-fd-bootchk
1797@findex -no-fd-bootchk
1798Disable boot signature checking for floppy disks in BIOS. May
1799be needed to boot from old floppy disks.
1800ETEXI
1801
1802DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1803           "-no-acpi        disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1804STEXI
1805@item -no-acpi
1806@findex -no-acpi
1807Disable ACPI (Advanced Configuration and Power Interface) support. Use
1808it if your guest OS complains about ACPI problems (PC target machine
1809only).
1810ETEXI
1811
1812DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1813    "-no-hpet        disable HPET\n", QEMU_ARCH_I386)
1814STEXI
1815@item -no-hpet
1816@findex -no-hpet
1817Disable HPET support.
1818ETEXI
1819
1820DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1821    "-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"
1822    "                ACPI table description\n", QEMU_ARCH_I386)
1823STEXI
1824@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}]...]
1825@findex -acpitable
1826Add ACPI table with specified header fields and context from specified files.
1827For file=, take whole ACPI table from the specified files, including all
1828ACPI headers (possible overridden by other options).
1829For data=, only data
1830portion of the table is used, all header information is specified in the
1831command line.
1832If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1833fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1834to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1835spec.
1836ETEXI
1837
1838DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1839    "-smbios file=binary\n"
1840    "                load SMBIOS entry from binary file\n"
1841    "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1842    "              [,uefi=on|off]\n"
1843    "                specify SMBIOS type 0 fields\n"
1844    "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1845    "              [,uuid=uuid][,sku=str][,family=str]\n"
1846    "                specify SMBIOS type 1 fields\n"
1847    "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1848    "              [,asset=str][,location=str]\n"
1849    "                specify SMBIOS type 2 fields\n"
1850    "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1851    "              [,sku=str]\n"
1852    "                specify SMBIOS type 3 fields\n"
1853    "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1854    "              [,asset=str][,part=str]\n"
1855    "                specify SMBIOS type 4 fields\n"
1856    "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1857    "               [,asset=str][,part=str][,speed=%d]\n"
1858    "                specify SMBIOS type 17 fields\n",
1859    QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1860STEXI
1861@item -smbios file=@var{binary}
1862@findex -smbios
1863Load SMBIOS entry from binary file.
1864
1865@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1866Specify SMBIOS type 0 fields
1867
1868@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}]
1869Specify SMBIOS type 1 fields
1870
1871@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}]
1872Specify SMBIOS type 2 fields
1873
1874@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1875Specify SMBIOS type 3 fields
1876
1877@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1878Specify SMBIOS type 4 fields
1879
1880@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}]
1881Specify SMBIOS type 17 fields
1882ETEXI
1883
1884STEXI
1885@end table
1886ETEXI
1887DEFHEADING()
1888
1889DEFHEADING(Network options:)
1890STEXI
1891@table @option
1892ETEXI
1893
1894HXCOMM Legacy slirp options (now moved to -net user):
1895#ifdef CONFIG_SLIRP
1896DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1897DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1898DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1899#ifndef _WIN32
1900DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1901#endif
1902#endif
1903
1904DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1905#ifdef CONFIG_SLIRP
1906    "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1907    "         [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1908    "         [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1909    "         [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
1910    "         [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1911#ifndef _WIN32
1912                                             "[,smb=dir[,smbserver=addr]]\n"
1913#endif
1914    "                configure a user mode network backend with ID 'str',\n"
1915    "                its DHCP server and optional services\n"
1916#endif
1917#ifdef _WIN32
1918    "-netdev tap,id=str,ifname=name\n"
1919    "                configure a host TAP network backend with ID 'str'\n"
1920#else
1921    "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1922    "         [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1923    "         [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1924    "         [,poll-us=n]\n"
1925    "                configure a host TAP network backend with ID 'str'\n"
1926    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1927    "                use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1928    "                to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1929    "                to deconfigure it\n"
1930    "                use '[down]script=no' to disable script execution\n"
1931    "                use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1932    "                configure it\n"
1933    "                use 'fd=h' to connect to an already opened TAP interface\n"
1934    "                use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1935    "                use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1936    "                default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1937    "                use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1938    "                use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1939    "                use vhost=on to enable experimental in kernel accelerator\n"
1940    "                    (only has effect for virtio guests which use MSIX)\n"
1941    "                use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1942    "                use 'vhostfd=h' to connect to an already opened vhost net device\n"
1943    "                use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1944    "                use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1945    "                use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1946    "                spent on busy polling for vhost net\n"
1947    "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1948    "                configure a host TAP network backend with ID 'str' that is\n"
1949    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1950    "                using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1951#endif
1952#ifdef __linux__
1953    "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1954    "         [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1955    "         [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1956    "         [,rxcookie=rxcookie][,offset=offset]\n"
1957    "                configure a network backend with ID 'str' connected to\n"
1958    "                an Ethernet over L2TPv3 pseudowire.\n"
1959    "                Linux kernel 3.3+ as well as most routers can talk\n"
1960    "                L2TPv3. This transport allows connecting a VM to a VM,\n"
1961    "                VM to a router and even VM to Host. It is a nearly-universal\n"
1962    "                standard (RFC3391). Note - this implementation uses static\n"
1963    "                pre-configured tunnels (same as the Linux kernel).\n"
1964    "                use 'src=' to specify source address\n"
1965    "                use 'dst=' to specify destination address\n"
1966    "                use 'udp=on' to specify udp encapsulation\n"
1967    "                use 'srcport=' to specify source udp port\n"
1968    "                use 'dstport=' to specify destination udp port\n"
1969    "                use 'ipv6=on' to force v6\n"
1970    "                L2TPv3 uses cookies to prevent misconfiguration as\n"
1971    "                well as a weak security measure\n"
1972    "                use 'rxcookie=0x012345678' to specify a rxcookie\n"
1973    "                use 'txcookie=0x012345678' to specify a txcookie\n"
1974    "                use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1975    "                use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1976    "                use 'pincounter=on' to work around broken counter handling in peer\n"
1977    "                use 'offset=X' to add an extra offset between header and data\n"
1978#endif
1979    "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1980    "                configure a network backend to connect to another network\n"
1981    "                using a socket connection\n"
1982    "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1983    "                configure a network backend to connect to a multicast maddr and port\n"
1984    "                use 'localaddr=addr' to specify the host address to send packets from\n"
1985    "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1986    "                configure a network backend to connect to another network\n"
1987    "                using an UDP tunnel\n"
1988#ifdef CONFIG_VDE
1989    "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1990    "                configure a network backend to connect to port 'n' of a vde switch\n"
1991    "                running on host and listening for incoming connections on 'socketpath'.\n"
1992    "                Use group 'groupname' and mode 'octalmode' to change default\n"
1993    "                ownership and permissions for communication port.\n"
1994#endif
1995#ifdef CONFIG_NETMAP
1996    "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1997    "                attach to the existing netmap-enabled network interface 'name', or to a\n"
1998    "                VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1999    "                netmap device, defaults to '/dev/netmap')\n"
2000#endif
2001#ifdef CONFIG_POSIX
2002    "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2003    "                configure a vhost-user network, backed by a chardev 'dev'\n"
2004#endif
2005    "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
2006    "                configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
2007DEF("nic", HAS_ARG, QEMU_OPTION_nic,
2008    "--nic [tap|bridge|"
2009#ifdef CONFIG_SLIRP
2010    "user|"
2011#endif
2012#ifdef __linux__
2013    "l2tpv3|"
2014#endif
2015#ifdef CONFIG_VDE
2016    "vde|"
2017#endif
2018#ifdef CONFIG_NETMAP
2019    "netmap|"
2020#endif
2021#ifdef CONFIG_POSIX
2022    "vhost-user|"
2023#endif
2024    "socket][,option][,...][mac=macaddr]\n"
2025    "                initialize an on-board / default host NIC (using MAC address\n"
2026    "                macaddr) and connect it to the given host network backend\n"
2027    "--nic none      use it alone to have zero network devices (the default is to\n"
2028    "                provided a 'user' network connection)\n",
2029    QEMU_ARCH_ALL)
2030DEF("net", HAS_ARG, QEMU_OPTION_net,
2031    "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
2032    "                configure or create an on-board (or machine default) NIC and\n"
2033    "                connect it to hub 0 (please use -nic unless you need a hub)\n"
2034    "-net ["
2035#ifdef CONFIG_SLIRP
2036    "user|"
2037#endif
2038    "tap|"
2039    "bridge|"
2040#ifdef CONFIG_VDE
2041    "vde|"
2042#endif
2043#ifdef CONFIG_NETMAP
2044    "netmap|"
2045#endif
2046    "socket][,option][,option][,...]\n"
2047    "                old way to initialize a host network interface\n"
2048    "                (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2049STEXI
2050@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]
2051@findex -nic
2052This option is a shortcut for configuring both the on-board (default) guest
2053NIC hardware and the host network backend in one go. The host backend options
2054are the same as with the corresponding @option{-netdev} options below.
2055The guest NIC model can be set with @option{model=@var{modelname}}.
2056Use @option{model=help} to list the available device types.
2057The hardware MAC address can be set with @option{mac=@var{macaddr}}.
2058
2059The following two example do exactly the same, to show how @option{-nic} can
2060be used to shorten the command line length (note that the e1000 is the default
2061on i386, so the @option{model=e1000} parameter could even be omitted here, too):
2062@example
2063qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
2064qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2065@end example
2066
2067@item -nic none
2068Indicate that no network devices should be configured. It is used to override
2069the default configuration (default NIC with ``user'' host network backend)
2070which is activated if no other networking options are provided.
2071
2072@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2073@findex -netdev
2074Configure user mode host network backend which requires no administrator
2075privilege to run. Valid options are:
2076
2077@table @option
2078@item id=@var{id}
2079Assign symbolic name for use in monitor commands.
2080
2081@item ipv4=on|off and ipv6=on|off
2082Specify that either IPv4 or IPv6 must be enabled. If neither is specified
2083both protocols are enabled.
2084
2085@item net=@var{addr}[/@var{mask}]
2086Set IP network address the guest will see. Optionally specify the netmask,
2087either in the form a.b.c.d or as number of valid top-most bits. Default is
208810.0.2.0/24.
2089
2090@item host=@var{addr}
2091Specify the guest-visible address of the host. Default is the 2nd IP in the
2092guest network, i.e. x.x.x.2.
2093
2094@item ipv6-net=@var{addr}[/@var{int}]
2095Set IPv6 network address the guest will see (default is fec0::/64). The
2096network prefix is given in the usual hexadecimal IPv6 address
2097notation. The prefix size is optional, and is given as the number of
2098valid top-most bits (default is 64).
2099
2100@item ipv6-host=@var{addr}
2101Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2102the guest network, i.e. xxxx::2.
2103
2104@item restrict=on|off
2105If this option is enabled, the guest will be isolated, i.e. it will not be
2106able to contact the host and no guest IP packets will be routed over the host
2107to the outside. This option does not affect any explicitly set forwarding rules.
2108
2109@item hostname=@var{name}
2110Specifies the client hostname reported by the built-in DHCP server.
2111
2112@item dhcpstart=@var{addr}
2113Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2114is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2115
2116@item dns=@var{addr}
2117Specify the guest-visible address of the virtual nameserver. The address must
2118be different from the host address. Default is the 3rd IP in the guest network,
2119i.e. x.x.x.3.
2120
2121@item ipv6-dns=@var{addr}
2122Specify the guest-visible address of the IPv6 virtual nameserver. The address
2123must be different from the host address. Default is the 3rd IP in the guest
2124network, i.e. xxxx::3.
2125
2126@item dnssearch=@var{domain}
2127Provides an entry for the domain-search list sent by the built-in
2128DHCP server. More than one domain suffix can be transmitted by specifying
2129this option multiple times. If supported, this will cause the guest to
2130automatically try to append the given domain suffix(es) in case a domain name
2131can not be resolved.
2132
2133Example:
2134@example
2135qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2136@end example
2137
2138@item tftp=@var{dir}
2139When using the user mode network stack, activate a built-in TFTP
2140server. The files in @var{dir} will be exposed as the root of a TFTP server.
2141The TFTP client on the guest must be configured in binary mode (use the command
2142@code{bin} of the Unix TFTP client).
2143
2144@item bootfile=@var{file}
2145When using the user mode network stack, broadcast @var{file} as the BOOTP
2146filename. In conjunction with @option{tftp}, this can be used to network boot
2147a guest from a local directory.
2148
2149Example (using pxelinux):
2150@example
2151qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2152    -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2153@end example
2154
2155@item smb=@var{dir}[,smbserver=@var{addr}]
2156When using the user mode network stack, activate a built-in SMB
2157server so that Windows OSes can access to the host files in @file{@var{dir}}
2158transparently. The IP address of the SMB server can be set to @var{addr}. By
2159default the 4th IP in the guest network is used, i.e. x.x.x.4.
2160
2161In the guest Windows OS, the line:
2162@example
216310.0.2.4 smbserver
2164@end example
2165must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2166or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2167
2168Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2169
2170Note that a SAMBA server must be installed on the host OS.
2171
2172@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2173Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2174the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2175@var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2176given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2177be bound to a specific host interface. If no connection type is set, TCP is
2178used. This option can be given multiple times.
2179
2180For example, to redirect host X11 connection from screen 1 to guest
2181screen 0, use the following:
2182
2183@example
2184# on the host
2185qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2186# this host xterm should open in the guest X11 server
2187xterm -display :1
2188@end example
2189
2190To redirect telnet connections from host port 5555 to telnet port on
2191the guest, use the following:
2192
2193@example
2194# on the host
2195qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2196telnet localhost 5555
2197@end example
2198
2199Then when you use on the host @code{telnet localhost 5555}, you
2200connect to the guest telnet server.
2201
2202@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2203@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2204Forward guest TCP connections to the IP address @var{server} on port @var{port}
2205to the character device @var{dev} or to a program executed by @var{cmd:command}
2206which gets spawned for each connection. This option can be given multiple times.
2207
2208You can either use a chardev directly and have that one used throughout QEMU's
2209lifetime, like in the following example:
2210
2211@example
2212# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2213# the guest accesses it
2214qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
2215@end example
2216
2217Or you can execute a command on every TCP connection established by the guest,
2218so that QEMU behaves similar to an inetd process for that virtual server:
2219
2220@example
2221# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2222# and connect the TCP stream to its stdin/stdout
2223qemu-system-i386 -nic  'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2224@end example
2225
2226@end table
2227
2228Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2229processed and applied to -net user. Mixing them with the new configuration
2230syntax gives undefined results. Their use for new applications is discouraged
2231as they will be removed from future versions.
2232
2233@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2234Configure a host TAP network backend with ID @var{id}.
2235
2236Use the network script @var{file} to configure it and the network script
2237@var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2238automatically provides one. The default network configure script is
2239@file{/etc/qemu-ifup} and the default network deconfigure script is
2240@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2241to disable script execution.
2242
2243If running QEMU as an unprivileged user, use the network helper
2244@var{helper} to configure the TAP interface and attach it to the bridge.
2245The default network helper executable is @file{/path/to/qemu-bridge-helper}
2246and the default bridge device is @file{br0}.
2247
2248@option{fd}=@var{h} can be used to specify the handle of an already
2249opened host TAP interface.
2250
2251Examples:
2252
2253@example
2254#launch a QEMU instance with the default network script
2255qemu-system-i386 linux.img -nic tap
2256@end example
2257
2258@example
2259#launch a QEMU instance with two NICs, each one connected
2260#to a TAP device
2261qemu-system-i386 linux.img \
2262        -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2263        -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2264@end example
2265
2266@example
2267#launch a QEMU instance with the default network helper to
2268#connect a TAP device to bridge br0
2269qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \
2270        -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
2271@end example
2272
2273@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2274Connect a host TAP network interface to a host bridge device.
2275
2276Use the network helper @var{helper} to configure the TAP interface and
2277attach it to the bridge. The default network helper executable is
2278@file{/path/to/qemu-bridge-helper} and the default bridge
2279device is @file{br0}.
2280
2281Examples:
2282
2283@example
2284#launch a QEMU instance with the default network helper to
2285#connect a TAP device to bridge br0
2286qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
2287@end example
2288
2289@example
2290#launch a QEMU instance with the default network helper to
2291#connect a TAP device to bridge qemubr0
2292qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
2293@end example
2294
2295@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2296
2297This host network backend can be used to connect the guest's network to
2298another QEMU virtual machine using a TCP socket connection. If @option{listen}
2299is specified, QEMU waits for incoming connections on @var{port}
2300(@var{host} is optional). @option{connect} is used to connect to
2301another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2302specifies an already opened TCP socket.
2303
2304Example:
2305@example
2306# launch a first QEMU instance
2307qemu-system-i386 linux.img \
2308                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2309                 -netdev socket,id=n1,listen=:1234
2310# connect the network of this instance to the network of the first instance
2311qemu-system-i386 linux.img \
2312                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2313                 -netdev socket,id=n2,connect=127.0.0.1:1234
2314@end example
2315
2316@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2317
2318Configure a socket host network backend to share the guest's network traffic
2319with another QEMU virtual machines using a UDP multicast socket, effectively
2320making a bus for every QEMU with same multicast address @var{maddr} and @var{port}.
2321NOTES:
2322@enumerate
2323@item
2324Several QEMU can be running on different hosts and share same bus (assuming
2325correct multicast setup for these hosts).
2326@item
2327mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2328@url{http://user-mode-linux.sf.net}.
2329@item
2330Use @option{fd=h} to specify an already opened UDP multicast socket.
2331@end enumerate
2332
2333Example:
2334@example
2335# launch one QEMU instance
2336qemu-system-i386 linux.img \
2337                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2338                 -netdev socket,id=n1,mcast=230.0.0.1:1234
2339# launch another QEMU instance on same "bus"
2340qemu-system-i386 linux.img \
2341                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2342                 -netdev socket,id=n2,mcast=230.0.0.1:1234
2343# launch yet another QEMU instance on same "bus"
2344qemu-system-i386 linux.img \
2345                 -device e1000,netdev=n3,macaddr=52:54:00:12:34:58 \
2346                 -netdev socket,id=n3,mcast=230.0.0.1:1234
2347@end example
2348
2349Example (User Mode Linux compat.):
2350@example
2351# launch QEMU instance (note mcast address selected is UML's default)
2352qemu-system-i386 linux.img \
2353                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2354                 -netdev socket,id=n1,mcast=239.192.168.1:1102
2355# launch UML
2356/path/to/linux ubd0=/path/to/root_fs eth0=mcast
2357@end example
2358
2359Example (send packets from host's 1.2.3.4):
2360@example
2361qemu-system-i386 linux.img \
2362                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2363                 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2364@end example
2365
2366@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}]
2367Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a
2368popular protocol to transport Ethernet (and other Layer 2) data frames between
2369two systems. It is present in routers, firewalls and the Linux kernel
2370(from version 3.3 onwards).
2371
2372This transport allows a VM to communicate to another VM, router or firewall directly.
2373
2374@table @option
2375@item src=@var{srcaddr}
2376    source address (mandatory)
2377@item dst=@var{dstaddr}
2378    destination address (mandatory)
2379@item udp
2380    select udp encapsulation (default is ip).
2381@item srcport=@var{srcport}
2382    source udp port.
2383@item dstport=@var{dstport}
2384    destination udp port.
2385@item ipv6
2386    force v6, otherwise defaults to v4.
2387@item rxcookie=@var{rxcookie}
2388@itemx txcookie=@var{txcookie}
2389    Cookies are a weak form of security in the l2tpv3 specification.
2390Their function is mostly to prevent misconfiguration. By default they are 32
2391bit.
2392@item cookie64
2393    Set cookie size to 64 bit instead of the default 32
2394@item counter=off
2395    Force a 'cut-down' L2TPv3 with no counter as in
2396draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2397@item pincounter=on
2398    Work around broken counter handling in peer. This may also help on
2399networks which have packet reorder.
2400@item offset=@var{offset}
2401    Add an extra offset between header and data
2402@end table
2403
2404For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2405on the remote Linux host 1.2.3.4:
2406@example
2407# Setup tunnel on linux host using raw ip as encapsulation
2408# on 1.2.3.4
2409ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2410    encap udp udp_sport 16384 udp_dport 16384
2411ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2412    0xFFFFFFFF peer_session_id 0xFFFFFFFF
2413ifconfig vmtunnel0 mtu 1500
2414ifconfig vmtunnel0 up
2415brctl addif br-lan vmtunnel0
2416
2417
2418# on 4.3.2.1
2419# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2420
2421qemu-system-i386 linux.img -device e1000,netdev=n1 \
2422    -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2423
2424@end example
2425
2426@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2427Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and
2428listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2429and MODE @var{octalmode} to change default ownership and permissions for
2430communication port. This option is only available if QEMU has been compiled
2431with vde support enabled.
2432
2433Example:
2434@example
2435# launch vde switch
2436vde_switch -F -sock /tmp/myswitch
2437# launch QEMU instance
2438qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch
2439@end example
2440
2441@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2442
2443Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2444be a unix domain socket backed one. The vhost-user uses a specifically defined
2445protocol to pass vhost ioctl replacement messages to an application on the other
2446end of the socket. On non-MSIX guests, the feature can be forced with
2447@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2448be created for multiqueue vhost-user.
2449
2450Example:
2451@example
2452qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2453     -numa node,memdev=mem \
2454     -chardev socket,id=chr0,path=/path/to/socket \
2455     -netdev type=vhost-user,id=net0,chardev=chr0 \
2456     -device virtio-net-pci,netdev=net0
2457@end example
2458
2459@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2460
2461Create a hub port on the emulated hub with ID @var{hubid}.
2462
2463The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2464single netdev. Alternatively, you can also connect the hubport to another
2465netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option.
2466
2467@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2468@findex -net
2469Legacy option to configure or create an on-board (or machine default) Network
2470Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e.
2471the default hub), or to the netdev @var{nd}.
2472The NIC is an e1000 by default on the PC target. Optionally, the MAC address
2473can be changed to @var{mac}, the device address set to @var{addr} (PCI cards
2474only), and a @var{name} can be assigned for use in monitor commands.
2475Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2476that the card should have; this option currently only affects virtio cards; set
2477@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2478NIC is created.  QEMU can emulate several different models of network card.
2479Use @code{-net nic,model=help} for a list of available devices for your target.
2480
2481@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}]
2482Configure a host network backend (with the options corresponding to the same
2483@option{-netdev} option) and connect it to the emulated hub 0 (the default
2484hub). Use @var{name} to specify the name of the hub port.
2485ETEXI
2486
2487STEXI
2488@end table
2489ETEXI
2490DEFHEADING()
2491
2492DEFHEADING(Character device options:)
2493
2494DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2495    "-chardev help\n"
2496    "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2497    "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2498    "         [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2499    "         [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2500    "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2501    "         [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2502    "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2503    "         [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2504    "         [,logfile=PATH][,logappend=on|off]\n"
2505    "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2506    "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2507    "         [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2508    "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2509    "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2510    "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2511#ifdef _WIN32
2512    "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2513    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2514#else
2515    "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2516    "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2517#endif
2518#ifdef CONFIG_BRLAPI
2519    "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2520#endif
2521#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2522        || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2523    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2524    "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2525#endif
2526#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2527    "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2528    "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2529#endif
2530#if defined(CONFIG_SPICE)
2531    "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2532    "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2533#endif
2534    , QEMU_ARCH_ALL
2535)
2536
2537STEXI
2538
2539The general form of a character device option is:
2540@table @option
2541@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2542@findex -chardev
2543Backend is one of:
2544@option{null},
2545@option{socket},
2546@option{udp},
2547@option{msmouse},
2548@option{vc},
2549@option{ringbuf},
2550@option{file},
2551@option{pipe},
2552@option{console},
2553@option{serial},
2554@option{pty},
2555@option{stdio},
2556@option{braille},
2557@option{tty},
2558@option{parallel},
2559@option{parport},
2560@option{spicevmc},
2561@option{spiceport}.
2562The specific backend will determine the applicable options.
2563
2564Use @code{-chardev help} to print all available chardev backend types.
2565
2566All devices must have an id, which can be any string up to 127 characters long.
2567It is used to uniquely identify this device in other command line directives.
2568
2569A character device may be used in multiplexing mode by multiple front-ends.
2570Specify @option{mux=on} to enable this mode.
2571A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2572backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2573If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2574create a multiplexer with your specified ID, and you can then configure multiple
2575front ends to use that chardev ID for their input/output. Up to four different
2576front ends can be connected to a single multiplexed chardev. (Without
2577multiplexing enabled, a chardev can only be used by a single front end.)
2578For instance you could use this to allow a single stdio chardev to be used by
2579two serial ports and the QEMU monitor:
2580
2581@example
2582-chardev stdio,mux=on,id=char0 \
2583-mon chardev=char0,mode=readline \
2584-serial chardev:char0 \
2585-serial chardev:char0
2586@end example
2587
2588You can have more than one multiplexer in a system configuration; for instance
2589you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2590multiplexed between the QEMU monitor and a parallel port:
2591
2592@example
2593-chardev stdio,mux=on,id=char0 \
2594-mon chardev=char0,mode=readline \
2595-parallel chardev:char0 \
2596-chardev tcp,...,mux=on,id=char1 \
2597-serial chardev:char1 \
2598-serial chardev:char1
2599@end example
2600
2601When you're using a multiplexed character device, some escape sequences are
2602interpreted in the input. @xref{mux_keys, Keys in the character backend
2603multiplexer}.
2604
2605Note that some other command line options may implicitly create multiplexed
2606character backends; for instance @option{-serial mon:stdio} creates a
2607multiplexed stdio backend connected to the serial port and the QEMU monitor,
2608and @option{-nographic} also multiplexes the console and the monitor to
2609stdio.
2610
2611There is currently no support for multiplexing in the other direction
2612(where a single QEMU front end takes input and output from multiple chardevs).
2613
2614Every backend supports the @option{logfile} option, which supplies the path
2615to a file to record all data transmitted via the backend. The @option{logappend}
2616option controls whether the log file will be truncated or appended to when
2617opened.
2618
2619@end table
2620
2621The available backends are:
2622
2623@table @option
2624@item -chardev null,id=@var{id}
2625A void device. This device will not emit any data, and will drop any data it
2626receives. The null backend does not take any options.
2627
2628@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2629
2630Create a two-way stream socket, which can be either a TCP or a unix socket. A
2631unix socket will be created if @option{path} is specified. Behaviour is
2632undefined if TCP options are specified for a unix socket.
2633
2634@option{server} specifies that the socket shall be a listening socket.
2635
2636@option{nowait} specifies that QEMU should not block waiting for a client to
2637connect to a listening socket.
2638
2639@option{telnet} specifies that traffic on the socket should interpret telnet
2640escape sequences.
2641
2642@option{reconnect} sets the timeout for reconnecting on non-server sockets when
2643the remote end goes away.  qemu will delay this many seconds and then attempt
2644to reconnect.  Zero disables reconnecting, and is the default.
2645
2646@option{tls-creds} requests enablement of the TLS protocol for encryption,
2647and specifies the id of the TLS credentials to use for the handshake. The
2648credentials must be previously created with the @option{-object tls-creds}
2649argument.
2650
2651TCP and unix socket options are given below:
2652
2653@table @option
2654
2655@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2656
2657@option{host} for a listening socket specifies the local address to be bound.
2658For a connecting socket species the remote host to connect to. @option{host} is
2659optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2660
2661@option{port} for a listening socket specifies the local port to be bound. For a
2662connecting socket specifies the port on the remote host to connect to.
2663@option{port} can be given as either a port number or a service name.
2664@option{port} is required.
2665
2666@option{to} is only relevant to listening sockets. If it is specified, and
2667@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2668to and including @option{to} until it succeeds. @option{to} must be specified
2669as a port number.
2670
2671@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2672If neither is specified the socket may use either protocol.
2673
2674@option{nodelay} disables the Nagle algorithm.
2675
2676@item unix options: path=@var{path}
2677
2678@option{path} specifies the local path of the unix socket. @option{path} is
2679required.
2680
2681@end table
2682
2683@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2684
2685Sends all traffic from the guest to a remote host over UDP.
2686
2687@option{host} specifies the remote host to connect to. If not specified it
2688defaults to @code{localhost}.
2689
2690@option{port} specifies the port on the remote host to connect to. @option{port}
2691is required.
2692
2693@option{localaddr} specifies the local address to bind to. If not specified it
2694defaults to @code{0.0.0.0}.
2695
2696@option{localport} specifies the local port to bind to. If not specified any
2697available local port will be used.
2698
2699@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2700If neither is specified the device may use either protocol.
2701
2702@item -chardev msmouse,id=@var{id}
2703
2704Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2705take any options.
2706
2707@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2708
2709Connect to a QEMU text console. @option{vc} may optionally be given a specific
2710size.
2711
2712@option{width} and @option{height} specify the width and height respectively of
2713the console, in pixels.
2714
2715@option{cols} and @option{rows} specify that the console be sized to fit a text
2716console with the given dimensions.
2717
2718@item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2719
2720Create a ring buffer with fixed size @option{size}.
2721@var{size} must be a power of two and defaults to @code{64K}.
2722
2723@item -chardev file,id=@var{id},path=@var{path}
2724
2725Log all traffic received from the guest to a file.
2726
2727@option{path} specifies the path of the file to be opened. This file will be
2728created if it does not already exist, and overwritten if it does. @option{path}
2729is required.
2730
2731@item -chardev pipe,id=@var{id},path=@var{path}
2732
2733Create a two-way connection to the guest. The behaviour differs slightly between
2734Windows hosts and other hosts:
2735
2736On Windows, a single duplex pipe will be created at
2737@file{\\.pipe\@option{path}}.
2738
2739On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2740@file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2741received by the guest. Data written by the guest can be read from
2742@file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2743be present.
2744
2745@option{path} forms part of the pipe path as described above. @option{path} is
2746required.
2747
2748@item -chardev console,id=@var{id}
2749
2750Send traffic from the guest to QEMU's standard output. @option{console} does not
2751take any options.
2752
2753@option{console} is only available on Windows hosts.
2754
2755@item -chardev serial,id=@var{id},path=@option{path}
2756
2757Send traffic from the guest to a serial device on the host.
2758
2759On Unix hosts serial will actually accept any tty device,
2760not only serial lines.
2761
2762@option{path} specifies the name of the serial device to open.
2763
2764@item -chardev pty,id=@var{id}
2765
2766Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2767not take any options.
2768
2769@option{pty} is not available on Windows hosts.
2770
2771@item -chardev stdio,id=@var{id}[,signal=on|off]
2772Connect to standard input and standard output of the QEMU process.
2773
2774@option{signal} controls if signals are enabled on the terminal, that includes
2775exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2776default, use @option{signal=off} to disable it.
2777
2778@item -chardev braille,id=@var{id}
2779
2780Connect to a local BrlAPI server. @option{braille} does not take any options.
2781
2782@item -chardev tty,id=@var{id},path=@var{path}
2783
2784@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2785DragonFlyBSD hosts.  It is an alias for @option{serial}.
2786
2787@option{path} specifies the path to the tty. @option{path} is required.
2788
2789@item -chardev parallel,id=@var{id},path=@var{path}
2790@itemx -chardev parport,id=@var{id},path=@var{path}
2791
2792@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2793
2794Connect to a local parallel port.
2795
2796@option{path} specifies the path to the parallel port device. @option{path} is
2797required.
2798
2799@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2800
2801@option{spicevmc} is only available when spice support is built in.
2802
2803@option{debug} debug level for spicevmc
2804
2805@option{name} name of spice channel to connect to
2806
2807Connect to a spice virtual machine channel, such as vdiport.
2808
2809@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2810
2811@option{spiceport} is only available when spice support is built in.
2812
2813@option{debug} debug level for spicevmc
2814
2815@option{name} name of spice port to connect to
2816
2817Connect to a spice port, allowing a Spice client to handle the traffic
2818identified by a name (preferably a fqdn).
2819ETEXI
2820
2821STEXI
2822@end table
2823ETEXI
2824DEFHEADING()
2825
2826DEFHEADING(Bluetooth(R) options:)
2827STEXI
2828@table @option
2829ETEXI
2830
2831DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2832    "-bt hci,null    dumb bluetooth HCI - doesn't respond to commands\n" \
2833    "-bt hci,host[:id]\n" \
2834    "                use host's HCI with the given name\n" \
2835    "-bt hci[,vlan=n]\n" \
2836    "                emulate a standard HCI in virtual scatternet 'n'\n" \
2837    "-bt vhci[,vlan=n]\n" \
2838    "                add host computer to virtual scatternet 'n' using VHCI\n" \
2839    "-bt device:dev[,vlan=n]\n" \
2840    "                emulate a bluetooth device 'dev' in scatternet 'n'\n",
2841    QEMU_ARCH_ALL)
2842STEXI
2843@item -bt hci[...]
2844@findex -bt
2845Defines the function of the corresponding Bluetooth HCI.  -bt options
2846are matched with the HCIs present in the chosen machine type.  For
2847example when emulating a machine with only one HCI built into it, only
2848the first @code{-bt hci[...]} option is valid and defines the HCI's
2849logic.  The Transport Layer is decided by the machine type.  Currently
2850the machines @code{n800} and @code{n810} have one HCI and all other
2851machines have none.
2852
2853@anchor{bt-hcis}
2854The following three types are recognized:
2855
2856@table @option
2857@item -bt hci,null
2858(default) The corresponding Bluetooth HCI assumes no internal logic
2859and will not respond to any HCI commands or emit events.
2860
2861@item -bt hci,host[:@var{id}]
2862(@code{bluez} only) The corresponding HCI passes commands / events
2863to / from the physical HCI identified by the name @var{id} (default:
2864@code{hci0}) on the computer running QEMU.  Only available on @code{bluez}
2865capable systems like Linux.
2866
2867@item -bt hci[,vlan=@var{n}]
2868Add a virtual, standard HCI that will participate in the Bluetooth
2869scatternet @var{n} (default @code{0}).  Similarly to @option{-net}
2870VLANs, devices inside a bluetooth network @var{n} can only communicate
2871with other devices in the same network (scatternet).
2872@end table
2873
2874@item -bt vhci[,vlan=@var{n}]
2875(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2876to the host bluetooth stack instead of to the emulated target.  This
2877allows the host and target machines to participate in a common scatternet
2878and communicate.  Requires the Linux @code{vhci} driver installed.  Can
2879be used as following:
2880
2881@example
2882qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2883@end example
2884
2885@item -bt device:@var{dev}[,vlan=@var{n}]
2886Emulate a bluetooth device @var{dev} and place it in network @var{n}
2887(default @code{0}).  QEMU can only emulate one type of bluetooth devices
2888currently:
2889
2890@table @option
2891@item keyboard
2892Virtual wireless keyboard implementing the HIDP bluetooth profile.
2893@end table
2894ETEXI
2895
2896STEXI
2897@end table
2898ETEXI
2899DEFHEADING()
2900
2901#ifdef CONFIG_TPM
2902DEFHEADING(TPM device options:)
2903
2904DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2905    "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2906    "                use path to provide path to a character device; default is /dev/tpm0\n"
2907    "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2908    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2909    "-tpmdev emulator,id=id,chardev=dev\n"
2910    "                configure the TPM device using chardev backend\n",
2911    QEMU_ARCH_ALL)
2912STEXI
2913
2914The general form of a TPM device option is:
2915@table @option
2916
2917@item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2918@findex -tpmdev
2919
2920The specific backend type will determine the applicable options.
2921The @code{-tpmdev} option creates the TPM backend and requires a
2922@code{-device} option that specifies the TPM frontend interface model.
2923
2924Use @code{-tpmdev help} to print all available TPM backend types.
2925
2926@end table
2927
2928The available backends are:
2929
2930@table @option
2931
2932@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2933
2934(Linux-host only) Enable access to the host's TPM using the passthrough
2935driver.
2936
2937@option{path} specifies the path to the host's TPM device, i.e., on
2938a Linux host this would be @code{/dev/tpm0}.
2939@option{path} is optional and by default @code{/dev/tpm0} is used.
2940
2941@option{cancel-path} specifies the path to the host TPM device's sysfs
2942entry allowing for cancellation of an ongoing TPM command.
2943@option{cancel-path} is optional and by default QEMU will search for the
2944sysfs entry to use.
2945
2946Some notes about using the host's TPM with the passthrough driver:
2947
2948The TPM device accessed by the passthrough driver must not be
2949used by any other application on the host.
2950
2951Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2952the VM's firmware (BIOS/UEFI) will not be able to initialize the
2953TPM again and may therefore not show a TPM-specific menu that would
2954otherwise allow the user to configure the TPM, e.g., allow the user to
2955enable/disable or activate/deactivate the TPM.
2956Further, if TPM ownership is released from within a VM then the host's TPM
2957will get disabled and deactivated. To enable and activate the
2958TPM again afterwards, the host has to be rebooted and the user is
2959required to enter the firmware's menu to enable and activate the TPM.
2960If the TPM is left disabled and/or deactivated most TPM commands will fail.
2961
2962To create a passthrough TPM use the following two options:
2963@example
2964-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2965@end example
2966Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2967@code{tpmdev=tpm0} in the device option.
2968
2969@item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2970
2971(Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2972chardev backend.
2973
2974@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2975
2976To create a TPM emulator backend device with chardev socket backend:
2977@example
2978
2979-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2980
2981@end example
2982
2983ETEXI
2984
2985STEXI
2986@end table
2987ETEXI
2988DEFHEADING()
2989
2990#endif
2991
2992DEFHEADING(Linux/Multiboot boot specific:)
2993STEXI
2994
2995When using these options, you can use a given Linux or Multiboot
2996kernel without installing it in the disk image. It can be useful
2997for easier testing of various kernels.
2998
2999@table @option
3000ETEXI
3001
3002DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
3003    "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
3004STEXI
3005@item -kernel @var{bzImage}
3006@findex -kernel
3007Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
3008or in multiboot format.
3009ETEXI
3010
3011DEF("append", HAS_ARG, QEMU_OPTION_append, \
3012    "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
3013STEXI
3014@item -append @var{cmdline}
3015@findex -append
3016Use @var{cmdline} as kernel command line
3017ETEXI
3018
3019DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
3020           "-initrd file    use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
3021STEXI
3022@item -initrd @var{file}
3023@findex -initrd
3024Use @var{file} as initial ram disk.
3025
3026@item -initrd "@var{file1} arg=foo,@var{file2}"
3027
3028This syntax is only available with multiboot.
3029
3030Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3031first module.
3032ETEXI
3033
3034DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
3035    "-dtb    file    use 'file' as device tree image\n", QEMU_ARCH_ALL)
3036STEXI
3037@item -dtb @var{file}
3038@findex -dtb
3039Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3040on boot.
3041ETEXI
3042
3043STEXI
3044@end table
3045ETEXI
3046DEFHEADING()
3047
3048DEFHEADING(Debug/Expert options:)
3049STEXI
3050@table @option
3051ETEXI
3052
3053DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3054    "-fw_cfg [name=]<name>,file=<file>\n"
3055    "                add named fw_cfg entry with contents from file\n"
3056    "-fw_cfg [name=]<name>,string=<str>\n"
3057    "                add named fw_cfg entry with contents from string\n",
3058    QEMU_ARCH_ALL)
3059STEXI
3060
3061@item -fw_cfg [name=]@var{name},file=@var{file}
3062@findex -fw_cfg
3063Add named fw_cfg entry with contents from file @var{file}.
3064
3065@item -fw_cfg [name=]@var{name},string=@var{str}
3066Add named fw_cfg entry with contents from string @var{str}.
3067
3068The terminating NUL character of the contents of @var{str} will not be
3069included as part of the fw_cfg item data. To insert contents with
3070embedded NUL characters, you have to use the @var{file} parameter.
3071
3072The fw_cfg entries are passed by QEMU through to the guest.
3073
3074Example:
3075@example
3076    -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3077@end example
3078creates an fw_cfg entry named opt/com.mycompany/blob with contents
3079from ./my_blob.bin.
3080
3081ETEXI
3082
3083DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3084    "-serial dev     redirect the serial port to char device 'dev'\n",
3085    QEMU_ARCH_ALL)
3086STEXI
3087@item -serial @var{dev}
3088@findex -serial
3089Redirect the virtual serial port to host character device
3090@var{dev}. The default device is @code{vc} in graphical mode and
3091@code{stdio} in non graphical mode.
3092
3093This option can be used several times to simulate up to 4 serial
3094ports.
3095
3096Use @code{-serial none} to disable all serial ports.
3097
3098Available character devices are:
3099@table @option
3100@item vc[:@var{W}x@var{H}]
3101Virtual console. Optionally, a width and height can be given in pixel with
3102@example
3103vc:800x600
3104@end example
3105It is also possible to specify width or height in characters:
3106@example
3107vc:80Cx24C
3108@end example
3109@item pty
3110[Linux only] Pseudo TTY (a new PTY is automatically allocated)
3111@item none
3112No device is allocated.
3113@item null
3114void device
3115@item chardev:@var{id}
3116Use a named character device defined with the @code{-chardev} option.
3117@item /dev/XXX
3118[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3119parameters are set according to the emulated ones.
3120@item /dev/parport@var{N}
3121[Linux only, parallel port only] Use host parallel port
3122@var{N}. Currently SPP and EPP parallel port features can be used.
3123@item file:@var{filename}
3124Write output to @var{filename}. No character can be read.
3125@item stdio
3126[Unix only] standard input/output
3127@item pipe:@var{filename}
3128name pipe @var{filename}
3129@item COM@var{n}
3130[Windows only] Use host serial port @var{n}
3131@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3132This implements UDP Net Console.
3133When @var{remote_host} or @var{src_ip} are not specified
3134they default to @code{0.0.0.0}.
3135When not using a specified @var{src_port} a random port is automatically chosen.
3136
3137If you just want a simple readonly console you can use @code{netcat} or
3138@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3139@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3140will appear in the netconsole session.
3141
3142If you plan to send characters back via netconsole or you want to stop
3143and start QEMU a lot of times, you should have QEMU use the same
3144source port each time by using something like @code{-serial
3145udp::4555@@:4556} to QEMU. Another approach is to use a patched
3146version of netcat which can listen to a TCP port and send and receive
3147characters via udp.  If you have a patched version of netcat which
3148activates telnet remote echo and single char transfer, then you can
3149use the following options to set up a netcat redirector to allow
3150telnet on port 5555 to access the QEMU port.
3151@table @code
3152@item QEMU Options:
3153-serial udp::4555@@:4556
3154@item netcat options:
3155-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3156@item telnet options:
3157localhost 5555
3158@end table
3159
3160@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3161The TCP Net Console has two modes of operation.  It can send the serial
3162I/O to a location or wait for a connection from a location.  By default
3163the TCP Net Console is sent to @var{host} at the @var{port}.  If you use
3164the @var{server} option QEMU will wait for a client socket application
3165to connect to the port before continuing, unless the @code{nowait}
3166option was specified.  The @code{nodelay} option disables the Nagle buffering
3167algorithm.  The @code{reconnect} option only applies if @var{noserver} is
3168set, if the connection goes down it will attempt to reconnect at the
3169given interval.  If @var{host} is omitted, 0.0.0.0 is assumed. Only
3170one TCP connection at a time is accepted. You can use @code{telnet} to
3171connect to the corresponding character device.
3172@table @code
3173@item Example to send tcp console to 192.168.0.2 port 4444
3174-serial tcp:192.168.0.2:4444
3175@item Example to listen and wait on port 4444 for connection
3176-serial tcp::4444,server
3177@item Example to not wait and listen on ip 192.168.0.100 port 4444
3178-serial tcp:192.168.0.100:4444,server,nowait
3179@end table
3180
3181@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3182The telnet protocol is used instead of raw tcp sockets.  The options
3183work the same as if you had specified @code{-serial tcp}.  The
3184difference is that the port acts like a telnet server or client using
3185telnet option negotiation.  This will also allow you to send the
3186MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3187sequence.  Typically in unix telnet you do it with Control-] and then
3188type "send break" followed by pressing the enter key.
3189
3190@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3191A unix domain socket is used instead of a tcp socket.  The option works the
3192same as if you had specified @code{-serial tcp} except the unix domain socket
3193@var{path} is used for connections.
3194
3195@item mon:@var{dev_string}
3196This is a special option to allow the monitor to be multiplexed onto
3197another serial port.  The monitor is accessed with key sequence of
3198@key{Control-a} and then pressing @key{c}.
3199@var{dev_string} should be any one of the serial devices specified
3200above.  An example to multiplex the monitor onto a telnet server
3201listening on port 4444 would be:
3202@table @code
3203@item -serial mon:telnet::4444,server,nowait
3204@end table
3205When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3206QEMU any more but will be passed to the guest instead.
3207
3208@item braille
3209Braille device.  This will use BrlAPI to display the braille output on a real
3210or fake device.
3211
3212@item msmouse
3213Three button serial mouse. Configure the guest to use Microsoft protocol.
3214@end table
3215ETEXI
3216
3217DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3218    "-parallel dev   redirect the parallel port to char device 'dev'\n",
3219    QEMU_ARCH_ALL)
3220STEXI
3221@item -parallel @var{dev}
3222@findex -parallel
3223Redirect the virtual parallel port to host device @var{dev} (same
3224devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3225be used to use hardware devices connected on the corresponding host
3226parallel port.
3227
3228This option can be used several times to simulate up to 3 parallel
3229ports.
3230
3231Use @code{-parallel none} to disable all parallel ports.
3232ETEXI
3233
3234DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3235    "-monitor dev    redirect the monitor to char device 'dev'\n",
3236    QEMU_ARCH_ALL)
3237STEXI
3238@item -monitor @var{dev}
3239@findex -monitor
3240Redirect the monitor to host device @var{dev} (same devices as the
3241serial port).
3242The default device is @code{vc} in graphical mode and @code{stdio} in
3243non graphical mode.
3244Use @code{-monitor none} to disable the default monitor.
3245ETEXI
3246DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3247    "-qmp dev        like -monitor but opens in 'control' mode\n",
3248    QEMU_ARCH_ALL)
3249STEXI
3250@item -qmp @var{dev}
3251@findex -qmp
3252Like -monitor but opens in 'control' mode.
3253ETEXI
3254DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3255    "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3256    QEMU_ARCH_ALL)
3257STEXI
3258@item -qmp-pretty @var{dev}
3259@findex -qmp-pretty
3260Like -qmp but uses pretty JSON formatting.
3261ETEXI
3262
3263DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3264    "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3265STEXI
3266@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3267@findex -mon
3268Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3269easing human reading and debugging.
3270ETEXI
3271
3272DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3273    "-debugcon dev   redirect the debug console to char device 'dev'\n",
3274    QEMU_ARCH_ALL)
3275STEXI
3276@item -debugcon @var{dev}
3277@findex -debugcon
3278Redirect the debug console to host device @var{dev} (same devices as the
3279serial port).  The debug console is an I/O port which is typically port
32800xe9; writing to that I/O port sends output to this device.
3281The default device is @code{vc} in graphical mode and @code{stdio} in
3282non graphical mode.
3283ETEXI
3284
3285DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3286    "-pidfile file   write PID to 'file'\n", QEMU_ARCH_ALL)
3287STEXI
3288@item -pidfile @var{file}
3289@findex -pidfile
3290Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3291from a script.
3292ETEXI
3293
3294DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3295    "-singlestep     always run in singlestep mode\n", QEMU_ARCH_ALL)
3296STEXI
3297@item -singlestep
3298@findex -singlestep
3299Run the emulation in single step mode.
3300ETEXI
3301
3302DEF("S", 0, QEMU_OPTION_S, \
3303    "-S              freeze CPU at startup (use 'c' to start execution)\n",
3304    QEMU_ARCH_ALL)
3305STEXI
3306@item -S
3307@findex -S
3308Do not start CPU at startup (you must type 'c' in the monitor).
3309ETEXI
3310
3311DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3312    "-realtime [mlock=on|off]\n"
3313    "                run qemu with realtime features\n"
3314    "                mlock=on|off controls mlock support (default: on)\n",
3315    QEMU_ARCH_ALL)
3316STEXI
3317@item -realtime mlock=on|off
3318@findex -realtime
3319Run qemu with realtime features.
3320mlocking qemu and guest memory can be enabled via @option{mlock=on}
3321(enabled by default).
3322ETEXI
3323
3324DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3325    "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3326STEXI
3327@item -gdb @var{dev}
3328@findex -gdb
3329Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3330connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3331stdio are reasonable use case. The latter is allowing to start QEMU from
3332within gdb and establish the connection via a pipe:
3333@example
3334(gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3335@end example
3336ETEXI
3337
3338DEF("s", 0, QEMU_OPTION_s, \
3339    "-s              shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3340    QEMU_ARCH_ALL)
3341STEXI
3342@item -s
3343@findex -s
3344Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3345(@pxref{gdb_usage}).
3346ETEXI
3347
3348DEF("d", HAS_ARG, QEMU_OPTION_d, \
3349    "-d item1,...    enable logging of specified items (use '-d help' for a list of log items)\n",
3350    QEMU_ARCH_ALL)
3351STEXI
3352@item -d @var{item1}[,...]
3353@findex -d
3354Enable logging of specified items. Use '-d help' for a list of log items.
3355ETEXI
3356
3357DEF("D", HAS_ARG, QEMU_OPTION_D, \
3358    "-D logfile      output log to logfile (default stderr)\n",
3359    QEMU_ARCH_ALL)
3360STEXI
3361@item -D @var{logfile}
3362@findex -D
3363Output log in @var{logfile} instead of to stderr
3364ETEXI
3365
3366DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3367    "-dfilter range,..  filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3368    QEMU_ARCH_ALL)
3369STEXI
3370@item -dfilter @var{range1}[,...]
3371@findex -dfilter
3372Filter debug output to that relevant to a range of target addresses. The filter
3373spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3374@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3375addresses and sizes required. For example:
3376@example
3377    -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3378@end example
3379Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3380the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3381block starting at 0xffffffc00005f000.
3382ETEXI
3383
3384DEF("L", HAS_ARG, QEMU_OPTION_L, \
3385    "-L path         set the directory for the BIOS, VGA BIOS and keymaps\n",
3386    QEMU_ARCH_ALL)
3387STEXI
3388@item -L  @var{path}
3389@findex -L
3390Set the directory for the BIOS, VGA BIOS and keymaps.
3391
3392To list all the data directories, use @code{-L help}.
3393ETEXI
3394
3395DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3396    "-bios file      set the filename for the BIOS\n", QEMU_ARCH_ALL)
3397STEXI
3398@item -bios @var{file}
3399@findex -bios
3400Set the filename for the BIOS.
3401ETEXI
3402
3403DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3404    "-enable-kvm     enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3405STEXI
3406@item -enable-kvm
3407@findex -enable-kvm
3408Enable KVM full virtualization support. This option is only available
3409if KVM support is enabled when compiling.
3410ETEXI
3411
3412DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3413    "-enable-hax     enable HAX virtualization support\n", QEMU_ARCH_I386)
3414STEXI
3415@item -enable-hax
3416@findex -enable-hax
3417Enable HAX (Hardware-based Acceleration eXecution) support. This option
3418is only available if HAX support is enabled when compiling. HAX is only
3419applicable to MAC and Windows platform, and thus does not conflict with
3420KVM.
3421ETEXI
3422
3423DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3424    "-xen-domid id   specify xen guest domain id\n", QEMU_ARCH_ALL)
3425DEF("xen-create", 0, QEMU_OPTION_xen_create,
3426    "-xen-create     create domain using xen hypercalls, bypassing xend\n"
3427    "                warning: should not be used when xend is in use\n",
3428    QEMU_ARCH_ALL)
3429DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3430    "-xen-attach     attach to existing xen domain\n"
3431    "                xend will use this when starting QEMU\n",
3432    QEMU_ARCH_ALL)
3433DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3434    "-xen-domid-restrict     restrict set of available xen operations\n"
3435    "                        to specified domain id. (Does not affect\n"
3436    "                        xenpv machine type).\n",
3437    QEMU_ARCH_ALL)
3438STEXI
3439@item -xen-domid @var{id}
3440@findex -xen-domid
3441Specify xen guest domain @var{id} (XEN only).
3442@item -xen-create
3443@findex -xen-create
3444Create domain using xen hypercalls, bypassing xend.
3445Warning: should not be used when xend is in use (XEN only).
3446@item -xen-attach
3447@findex -xen-attach
3448Attach to existing xen domain.
3449xend will use this when starting QEMU (XEN only).
3450@findex -xen-domid-restrict
3451Restrict set of available xen operations to specified domain id (XEN only).
3452ETEXI
3453
3454DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3455    "-no-reboot      exit instead of rebooting\n", QEMU_ARCH_ALL)
3456STEXI
3457@item -no-reboot
3458@findex -no-reboot
3459Exit instead of rebooting.
3460ETEXI
3461
3462DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3463    "-no-shutdown    stop before shutdown\n", QEMU_ARCH_ALL)
3464STEXI
3465@item -no-shutdown
3466@findex -no-shutdown
3467Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3468This allows for instance switching to monitor to commit changes to the
3469disk image.
3470ETEXI
3471
3472DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3473    "-loadvm [tag|id]\n" \
3474    "                start right away with a saved state (loadvm in monitor)\n",
3475    QEMU_ARCH_ALL)
3476STEXI
3477@item -loadvm @var{file}
3478@findex -loadvm
3479Start right away with a saved state (@code{loadvm} in monitor)
3480ETEXI
3481
3482#ifndef _WIN32
3483DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3484    "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3485#endif
3486STEXI
3487@item -daemonize
3488@findex -daemonize
3489Daemonize the QEMU process after initialization.  QEMU will not detach from
3490standard IO until it is ready to receive connections on any of its devices.
3491This option is a useful way for external programs to launch QEMU without having
3492to cope with initialization race conditions.
3493ETEXI
3494
3495DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3496    "-option-rom rom load a file, rom, into the option ROM space\n",
3497    QEMU_ARCH_ALL)
3498STEXI
3499@item -option-rom @var{file}
3500@findex -option-rom
3501Load the contents of @var{file} as an option ROM.
3502This option is useful to load things like EtherBoot.
3503ETEXI
3504
3505HXCOMM Silently ignored for compatibility
3506DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3507
3508HXCOMM Options deprecated by -rtc
3509DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3510DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3511
3512DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3513    "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3514    "                set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3515    QEMU_ARCH_ALL)
3516
3517STEXI
3518
3519@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3520@findex -rtc
3521Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3522UTC or local time, respectively. @code{localtime} is required for correct date in
3523MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3524format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3525
3526By default the RTC is driven by the host system time. This allows using of the
3527RTC as accurate reference clock inside the guest, specifically if the host
3528time is smoothly following an accurate external reference clock, e.g. via NTP.
3529If you want to isolate the guest time from the host, you can set @option{clock}
3530to @code{rt} instead.  To even prevent it from progressing during suspension,
3531you can set it to @code{vm}.
3532
3533Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3534specifically with Windows' ACPI HAL. This option will try to figure out how
3535many timer interrupts were not processed by the Windows guest and will
3536re-inject them.
3537ETEXI
3538
3539DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3540    "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3541    "                enable virtual instruction counter with 2^N clock ticks per\n" \
3542    "                instruction, enable aligning the host and virtual clocks\n" \
3543    "                or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3544STEXI
3545@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3546@findex -icount
3547Enable virtual instruction counter.  The virtual cpu will execute one
3548instruction every 2^@var{N} ns of virtual time.  If @code{auto} is specified
3549then the virtual cpu speed will be automatically adjusted to keep virtual
3550time within a few seconds of real time.
3551
3552When the virtual cpu is sleeping, the virtual time will advance at default
3553speed unless @option{sleep=on|off} is specified.
3554With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3555instantly whenever the virtual cpu goes to sleep mode and will not advance
3556if no timer is enabled. This behavior give deterministic execution times from
3557the guest point of view.
3558
3559Note that while this option can give deterministic behavior, it does not
3560provide cycle accurate emulation.  Modern CPUs contain superscalar out of
3561order cores with complex cache hierarchies.  The number of instructions
3562executed often has little or no correlation with actual performance.
3563
3564@option{align=on} will activate the delay algorithm which will try
3565to synchronise the host clock and the virtual clock. The goal is to
3566have a guest running at the real frequency imposed by the shift option.
3567Whenever the guest clock is behind the host clock and if
3568@option{align=on} is specified then we print a message to the user
3569to inform about the delay.
3570Currently this option does not work when @option{shift} is @code{auto}.
3571Note: The sync algorithm will work for those shift values for which
3572the guest clock runs ahead of the host clock. Typically this happens
3573when the shift value is high (how high depends on the host machine).
3574
3575When @option{rr} option is specified deterministic record/replay is enabled.
3576Replay log is written into @var{filename} file in record mode and
3577read from this file in replay mode.
3578
3579Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3580at the start of execution recording. In replay mode this option is used
3581to load the initial VM state.
3582ETEXI
3583
3584DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3585    "-watchdog model\n" \
3586    "                enable virtual hardware watchdog [default=none]\n",
3587    QEMU_ARCH_ALL)
3588STEXI
3589@item -watchdog @var{model}
3590@findex -watchdog
3591Create a virtual hardware watchdog device.  Once enabled (by a guest
3592action), the watchdog must be periodically polled by an agent inside
3593the guest or else the guest will be restarted. Choose a model for
3594which your guest has drivers.
3595
3596The @var{model} is the model of hardware watchdog to emulate. Use
3597@code{-watchdog help} to list available hardware models. Only one
3598watchdog can be enabled for a guest.
3599
3600The following models may be available:
3601@table @option
3602@item ib700
3603iBASE 700 is a very simple ISA watchdog with a single timer.
3604@item i6300esb
3605Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3606dual-timer watchdog.
3607@item diag288
3608A virtual watchdog for s390x backed by the diagnose 288 hypercall
3609(currently KVM only).
3610@end table
3611ETEXI
3612
3613DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3614    "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3615    "                action when watchdog fires [default=reset]\n",
3616    QEMU_ARCH_ALL)
3617STEXI
3618@item -watchdog-action @var{action}
3619@findex -watchdog-action
3620
3621The @var{action} controls what QEMU will do when the watchdog timer
3622expires.
3623The default is
3624@code{reset} (forcefully reset the guest).
3625Other possible actions are:
3626@code{shutdown} (attempt to gracefully shutdown the guest),
3627@code{poweroff} (forcefully poweroff the guest),
3628@code{inject-nmi} (inject a NMI into the guest),
3629@code{pause} (pause the guest),
3630@code{debug} (print a debug message and continue), or
3631@code{none} (do nothing).
3632
3633Note that the @code{shutdown} action requires that the guest responds
3634to ACPI signals, which it may not be able to do in the sort of
3635situations where the watchdog would have expired, and thus
3636@code{-watchdog-action shutdown} is not recommended for production use.
3637
3638Examples:
3639
3640@table @code
3641@item -watchdog i6300esb -watchdog-action pause
3642@itemx -watchdog ib700
3643@end table
3644ETEXI
3645
3646DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3647    "-echr chr       set terminal escape character instead of ctrl-a\n",
3648    QEMU_ARCH_ALL)
3649STEXI
3650
3651@item -echr @var{numeric_ascii_value}
3652@findex -echr
3653Change the escape character used for switching to the monitor when using
3654monitor and serial sharing.  The default is @code{0x01} when using the
3655@code{-nographic} option.  @code{0x01} is equal to pressing
3656@code{Control-a}.  You can select a different character from the ascii
3657control keys where 1 through 26 map to Control-a through Control-z.  For
3658instance you could use the either of the following to change the escape
3659character to Control-t.
3660@table @code
3661@item -echr 0x14
3662@itemx -echr 20
3663@end table
3664ETEXI
3665
3666DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3667    "-virtioconsole c\n" \
3668    "                set virtio console\n", QEMU_ARCH_ALL)
3669STEXI
3670@item -virtioconsole @var{c}
3671@findex -virtioconsole
3672Set virtio console.
3673This option is deprecated, please use @option{-device virtconsole} instead.
3674ETEXI
3675
3676DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3677    "-show-cursor    show cursor\n", QEMU_ARCH_ALL)
3678STEXI
3679@item -show-cursor
3680@findex -show-cursor
3681Show cursor.
3682ETEXI
3683
3684DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3685    "-tb-size n      set TB size\n", QEMU_ARCH_ALL)
3686STEXI
3687@item -tb-size @var{n}
3688@findex -tb-size
3689Set TB size.
3690ETEXI
3691
3692DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3693    "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3694    "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3695    "-incoming unix:socketpath\n" \
3696    "                prepare for incoming migration, listen on\n" \
3697    "                specified protocol and socket address\n" \
3698    "-incoming fd:fd\n" \
3699    "-incoming exec:cmdline\n" \
3700    "                accept incoming migration on given file descriptor\n" \
3701    "                or from given external command\n" \
3702    "-incoming defer\n" \
3703    "                wait for the URI to be specified via migrate_incoming\n",
3704    QEMU_ARCH_ALL)
3705STEXI
3706@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3707@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3708@findex -incoming
3709Prepare for incoming migration, listen on a given tcp port.
3710
3711@item -incoming unix:@var{socketpath}
3712Prepare for incoming migration, listen on a given unix socket.
3713
3714@item -incoming fd:@var{fd}
3715Accept incoming migration from a given filedescriptor.
3716
3717@item -incoming exec:@var{cmdline}
3718Accept incoming migration as an output from specified external command.
3719
3720@item -incoming defer
3721Wait for the URI to be specified via migrate_incoming.  The monitor can
3722be used to change settings (such as migration parameters) prior to issuing
3723the migrate_incoming to allow the migration to begin.
3724ETEXI
3725
3726DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3727    "-only-migratable     allow only migratable devices\n", QEMU_ARCH_ALL)
3728STEXI
3729@item -only-migratable
3730@findex -only-migratable
3731Only allow migratable devices. Devices will not be allowed to enter an
3732unmigratable state.
3733ETEXI
3734
3735DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3736    "-nodefaults     don't create default devices\n", QEMU_ARCH_ALL)
3737STEXI
3738@item -nodefaults
3739@findex -nodefaults
3740Don't create default devices. Normally, QEMU sets the default devices like serial
3741port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3742CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3743default devices.
3744ETEXI
3745
3746#ifndef _WIN32
3747DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3748    "-chroot dir     chroot to dir just before starting the VM\n",
3749    QEMU_ARCH_ALL)
3750#endif
3751STEXI
3752@item -chroot @var{dir}
3753@findex -chroot
3754Immediately before starting guest execution, chroot to the specified
3755directory.  Especially useful in combination with -runas.
3756ETEXI
3757
3758#ifndef _WIN32
3759DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3760    "-runas user     change to user id user just before starting the VM\n" \
3761    "                user can be numeric uid:gid instead\n",
3762    QEMU_ARCH_ALL)
3763#endif
3764STEXI
3765@item -runas @var{user}
3766@findex -runas
3767Immediately before starting guest execution, drop root privileges, switching
3768to the specified user.
3769ETEXI
3770
3771DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3772    "-prom-env variable=value\n"
3773    "                set OpenBIOS nvram variables\n",
3774    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3775STEXI
3776@item -prom-env @var{variable}=@var{value}
3777@findex -prom-env
3778Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3779ETEXI
3780DEF("semihosting", 0, QEMU_OPTION_semihosting,
3781    "-semihosting    semihosting mode\n",
3782    QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3783    QEMU_ARCH_MIPS)
3784STEXI
3785@item -semihosting
3786@findex -semihosting
3787Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3788ETEXI
3789DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3790    "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3791    "                semihosting configuration\n",
3792QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3793QEMU_ARCH_MIPS)
3794STEXI
3795@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3796@findex -semihosting-config
3797Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3798@table @option
3799@item target=@code{native|gdb|auto}
3800Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3801or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3802during debug sessions and @code{native} otherwise.
3803@item arg=@var{str1},arg=@var{str2},...
3804Allows the user to pass input arguments, and can be used multiple times to build
3805up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3806command line is still supported for backward compatibility. If both the
3807@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3808specified, the former is passed to semihosting as it always takes precedence.
3809@end table
3810ETEXI
3811DEF("old-param", 0, QEMU_OPTION_old_param,
3812    "-old-param      old param mode\n", QEMU_ARCH_ARM)
3813STEXI
3814@item -old-param
3815@findex -old-param (ARM)
3816Old param mode (ARM only).
3817ETEXI
3818
3819DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3820    "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3821    "          [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3822    "                Enable seccomp mode 2 system call filter (default 'off').\n" \
3823    "                use 'obsolete' to allow obsolete system calls that are provided\n" \
3824    "                    by the kernel, but typically no longer used by modern\n" \
3825    "                    C library implementations.\n" \
3826    "                use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3827    "                    its privileges by blacklisting all set*uid|gid system calls.\n" \
3828    "                    The value 'children' will deny set*uid|gid system calls for\n" \
3829    "                    main QEMU process but will allow forks and execves to run unprivileged\n" \
3830    "                use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3831    "                     blacklisting *fork and execve\n" \
3832    "                use 'resourcecontrol' to disable process affinity and schedular priority\n",
3833    QEMU_ARCH_ALL)
3834STEXI
3835@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3836@findex -sandbox
3837Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3838disable it.  The default is 'off'.
3839@table @option
3840@item obsolete=@var{string}
3841Enable Obsolete system calls
3842@item elevateprivileges=@var{string}
3843Disable set*uid|gid system calls
3844@item spawn=@var{string}
3845Disable *fork and execve
3846@item resourcecontrol=@var{string}
3847Disable process affinity and schedular priority
3848@end table
3849ETEXI
3850
3851DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3852    "-readconfig <file>\n", QEMU_ARCH_ALL)
3853STEXI
3854@item -readconfig @var{file}
3855@findex -readconfig
3856Read device configuration from @var{file}. This approach is useful when you want to spawn
3857QEMU process with many command line options but you don't want to exceed the command line
3858character limit.
3859ETEXI
3860DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3861    "-writeconfig <file>\n"
3862    "                read/write config file\n", QEMU_ARCH_ALL)
3863STEXI
3864@item -writeconfig @var{file}
3865@findex -writeconfig
3866Write device configuration to @var{file}. The @var{file} can be either filename to save
3867command line and device configuration into file or dash @code{-}) character to print the
3868output to stdout. This can be later used as input file for @code{-readconfig} option.
3869ETEXI
3870HXCOMM Deprecated, same as -no-user-config
3871DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
3872DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3873    "-no-user-config\n"
3874    "                do not load default user-provided config files at startup\n",
3875    QEMU_ARCH_ALL)
3876STEXI
3877@item -no-user-config
3878@findex -no-user-config
3879The @code{-no-user-config} option makes QEMU not load any of the user-provided
3880config files on @var{sysconfdir}.
3881ETEXI
3882DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3883    "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3884    "                specify tracing options\n",
3885    QEMU_ARCH_ALL)
3886STEXI
3887HXCOMM This line is not accurate, as some sub-options are backend-specific but
3888HXCOMM HX does not support conditional compilation of text.
3889@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3890@findex -trace
3891@include qemu-option-trace.texi
3892ETEXI
3893
3894HXCOMM Internal use
3895DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3896DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3897
3898#ifdef __linux__
3899DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3900    "-enable-fips    enable FIPS 140-2 compliance\n",
3901    QEMU_ARCH_ALL)
3902#endif
3903STEXI
3904@item -enable-fips
3905@findex -enable-fips
3906Enable FIPS 140-2 compliance mode.
3907ETEXI
3908
3909HXCOMM Deprecated by -machine accel=tcg property
3910DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3911
3912DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3913    "-msg timestamp[=on|off]\n"
3914    "                change the format of messages\n"
3915    "                on|off controls leading timestamps (default:on)\n",
3916    QEMU_ARCH_ALL)
3917STEXI
3918@item -msg timestamp[=on|off]
3919@findex -msg
3920prepend a timestamp to each log message.(default:on)
3921ETEXI
3922
3923DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3924    "-dump-vmstate <file>\n"
3925    "                Output vmstate information in JSON format to file.\n"
3926    "                Use the scripts/vmstate-static-checker.py file to\n"
3927    "                check for possible regressions in migration code\n"
3928    "                by comparing two such vmstate dumps.\n",
3929    QEMU_ARCH_ALL)
3930STEXI
3931@item -dump-vmstate @var{file}
3932@findex -dump-vmstate
3933Dump json-encoded vmstate information for current machine type to file
3934in @var{file}
3935ETEXI
3936
3937STEXI
3938@end table
3939ETEXI
3940DEFHEADING()
3941
3942DEFHEADING(Generic object creation:)
3943STEXI
3944@table @option
3945ETEXI
3946
3947DEF("object", HAS_ARG, QEMU_OPTION_object,
3948    "-object TYPENAME[,PROP1=VALUE1,...]\n"
3949    "                create a new object of type TYPENAME setting properties\n"
3950    "                in the order they are specified.  Note that the 'id'\n"
3951    "                property must be set.  These objects are placed in the\n"
3952    "                '/objects' path.\n",
3953    QEMU_ARCH_ALL)
3954STEXI
3955@item -object @var{typename}[,@var{prop1}=@var{value1},...]
3956@findex -object
3957Create a new object of type @var{typename} setting properties
3958in the order they are specified.  Note that the 'id'
3959property must be set.  These objects are placed in the
3960'/objects' path.
3961
3962@table @option
3963
3964@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}
3965
3966Creates a memory file backend object, which can be used to back
3967the guest RAM with huge pages.
3968
3969The @option{id} parameter is a unique ID that will be used to reference this
3970memory region when configuring the @option{-numa} argument.
3971
3972The @option{size} option provides the size of the memory region, and accepts
3973common suffixes, eg @option{500M}.
3974
3975The @option{mem-path} provides the path to either a shared memory or huge page
3976filesystem mount.
3977
3978The @option{share} boolean option determines whether the memory
3979region is marked as private to QEMU, or shared. The latter allows
3980a co-operating external process to access the QEMU memory region.
3981
3982The @option{share} is also required for pvrdma devices due to
3983limitations in the RDMA API provided by Linux.
3984
3985Setting share=on might affect the ability to configure NUMA
3986bindings for the memory backend under some circumstances, see
3987Documentation/vm/numa_memory_policy.txt on the Linux kernel
3988source tree for additional details.
3989
3990Setting the @option{discard-data} boolean option to @var{on}
3991indicates that file contents can be destroyed when QEMU exits,
3992to avoid unnecessarily flushing data to the backing file.  Note
3993that @option{discard-data} is only an optimization, and QEMU
3994might not discard file contents if it aborts unexpectedly or is
3995terminated using SIGKILL.
3996
3997The @option{merge} boolean option enables memory merge, also known as
3998MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
3999memory deduplication.
4000
4001Setting the @option{dump} boolean option to @var{off} excludes the memory from
4002core dumps. This feature is also known as MADV_DONTDUMP.
4003
4004The @option{prealloc} boolean option enables memory preallocation.
4005
4006The @option{host-nodes} option binds the memory range to a list of NUMA host
4007nodes.
4008
4009The @option{policy} option sets the NUMA policy to one of the following values:
4010
4011@table @option
4012@item @var{default}
4013default host policy
4014
4015@item @var{preferred}
4016prefer the given host node list for allocation
4017
4018@item @var{bind}
4019restrict memory allocation to the given host node list
4020
4021@item @var{interleave}
4022interleave memory allocations across the given host node list
4023@end table
4024
4025The @option{align} option specifies the base address alignment when
4026QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
4027@option{2M}. Some backend store specified by @option{mem-path}
4028requires an alignment different than the default one used by QEMU, eg
4029the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4030such cases, users can specify the required alignment via this option.
4031
4032@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}
4033
4034Creates a memory backend object, which can be used to back the guest RAM.
4035Memory backend objects offer more control than the @option{-m} option that is
4036traditionally used to define guest RAM. Please refer to
4037@option{memory-backend-file} for a description of the options.
4038
4039@item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},seal=@var{on|off},hugetlb=@var{on|off},hugetlbsize=@var{size}
4040
4041Creates an anonymous memory file backend object, which allows QEMU to
4042share the memory with an external process (e.g. when using
4043vhost-user). The memory is allocated with memfd and optional
4044sealing. (Linux only)
4045
4046The @option{seal} option creates a sealed-file, that will block
4047further resizing the memory ('on' by default).
4048
4049The @option{hugetlb} option specify the file to be created resides in
4050the hugetlbfs filesystem (since Linux 4.14).  Used in conjunction with
4051the @option{hugetlb} option, the @option{hugetlbsize} option specify
4052the hugetlb page size on systems that support multiple hugetlb page
4053sizes (it must be a power of 2 value supported by the system).
4054
4055In some versions of Linux, the @option{hugetlb} option is incompatible
4056with the @option{seal} option (requires at least Linux 4.16).
4057
4058Please refer to @option{memory-backend-file} for a description of the
4059other options.
4060
4061@item -object rng-random,id=@var{id},filename=@var{/dev/random}
4062
4063Creates a random number generator backend which obtains entropy from
4064a device on the host. The @option{id} parameter is a unique ID that
4065will be used to reference this entropy backend from the @option{virtio-rng}
4066device. The @option{filename} parameter specifies which file to obtain
4067entropy from and if omitted defaults to @option{/dev/random}.
4068
4069@item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4070
4071Creates a random number generator backend which obtains entropy from
4072an external daemon running on the host. The @option{id} parameter is
4073a unique ID that will be used to reference this entropy backend from
4074the @option{virtio-rng} device. The @option{chardev} parameter is
4075the unique ID of a character device backend that provides the connection
4076to the RNG daemon.
4077
4078@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4079
4080Creates a TLS anonymous credentials object, which can be used to provide
4081TLS support on network backends. The @option{id} parameter is a unique
4082ID which network backends will use to access the credentials. The
4083@option{endpoint} is either @option{server} or @option{client} depending
4084on whether the QEMU network backend that uses the credentials will be
4085acting as a client or as a server. If @option{verify-peer} is enabled
4086(the default) then once the handshake is completed, the peer credentials
4087will be verified, though this is a no-op for anonymous credentials.
4088
4089The @var{dir} parameter tells QEMU where to find the credential
4090files. For server endpoints, this directory may contain a file
4091@var{dh-params.pem} providing diffie-hellman parameters to use
4092for the TLS server. If the file is missing, QEMU will generate
4093a set of DH parameters at startup. This is a computationally
4094expensive operation that consumes random pool entropy, so it is
4095recommended that a persistent set of parameters be generated
4096upfront and saved.
4097
4098@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}
4099
4100Creates a TLS anonymous credentials object, which can be used to provide
4101TLS support on network backends. The @option{id} parameter is a unique
4102ID which network backends will use to access the credentials. The
4103@option{endpoint} is either @option{server} or @option{client} depending
4104on whether the QEMU network backend that uses the credentials will be
4105acting as a client or as a server. If @option{verify-peer} is enabled
4106(the default) then once the handshake is completed, the peer credentials
4107will be verified. With x509 certificates, this implies that the clients
4108must be provided with valid client certificates too.
4109
4110The @var{dir} parameter tells QEMU where to find the credential
4111files. For server endpoints, this directory may contain a file
4112@var{dh-params.pem} providing diffie-hellman parameters to use
4113for the TLS server. If the file is missing, QEMU will generate
4114a set of DH parameters at startup. This is a computationally
4115expensive operation that consumes random pool entropy, so it is
4116recommended that a persistent set of parameters be generated
4117upfront and saved.
4118
4119For x509 certificate credentials the directory will contain further files
4120providing the x509 certificates. The certificates must be stored
4121in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4122@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4123@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4124
4125For the @var{server-key.pem} and @var{client-key.pem} files which
4126contain sensitive private keys, it is possible to use an encrypted
4127version by providing the @var{passwordid} parameter. This provides
4128the ID of a previously created @code{secret} object containing the
4129password for decryption.
4130
4131The @var{priority} parameter allows to override the global default
4132priority used by gnutls. This can be useful if the system administrator
4133needs to use a weaker set of crypto priorities for QEMU without
4134potentially forcing the weakness onto all applications. Or conversely
4135if one wants wants a stronger default for QEMU than for all other
4136applications, they can do this through this parameter. Its format is
4137a gnutls priority string as described at
4138@url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4139
4140@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4141
4142Interval @var{t} can't be 0, this filter batches the packet delivery: all
4143packets arriving in a given interval on netdev @var{netdevid} are delayed
4144until the end of the interval. Interval is in microseconds.
4145@option{status} is optional that indicate whether the netfilter is
4146on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4147
4148queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4149
4150@option{all}: the filter is attached both to the receive and the transmit
4151              queue of the netdev (default).
4152
4153@option{rx}: the filter is attached to the receive queue of the netdev,
4154             where it will receive packets sent to the netdev.
4155
4156@option{tx}: the filter is attached to the transmit queue of the netdev,
4157             where it will receive packets sent by the netdev.
4158
4159@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4160
4161filter-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.
4162
4163@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4164
4165filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4166@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4167filter-redirector will redirect packet with vnet_hdr_len.
4168Create a filter-redirector we need to differ outdev id from indev id, id can not
4169be the same. we can just use indev or outdev, but at least one of indev or outdev
4170need to be specified.
4171
4172@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4173
4174Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4175secondary from primary to keep secondary tcp connection,and rewrite
4176tcp packet to primary from secondary make tcp packet can be handled by
4177client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4178
4179usage:
4180colo secondary:
4181-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4182-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4183-object filter-rewriter,id=rew0,netdev=hn0,queue=all
4184
4185@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4186
4187Dump the network traffic on netdev @var{dev} to the file specified by
4188@var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4189The file format is libpcap, so it can be analyzed with tools such as tcpdump
4190or Wireshark.
4191
4192@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4193
4194Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4195secondary packet. If the packets are same, we will output primary
4196packet to outdev@var{chardevid}, else we will notify colo-frame
4197do checkpoint and send primary packet to outdev@var{chardevid}.
4198if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4199
4200we must use it with the help of filter-mirror and filter-redirector.
4201
4202@example
4203
4204primary:
4205-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4206-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4207-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4208-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4209-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4210-chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4211-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4212-chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4213-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4214-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4215-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4216-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4217
4218secondary:
4219-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4220-device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4221-chardev socket,id=red0,host=3.3.3.3,port=9003
4222-chardev socket,id=red1,host=3.3.3.3,port=9004
4223-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4224-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4225
4226@end example
4227
4228If you want to know the detail of above command line, you can read
4229the colo-compare git log.
4230
4231@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4232
4233Creates a cryptodev backend which executes crypto opreation from
4234the QEMU cipher APIS. The @var{id} parameter is
4235a unique ID that will be used to reference this cryptodev backend from
4236the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4237which specify the queue number of cryptodev backend, the default of
4238@var{queues} is 1.
4239
4240@example
4241
4242 # qemu-system-x86_64 \
4243   [...] \
4244       -object cryptodev-backend-builtin,id=cryptodev0 \
4245       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4246   [...]
4247@end example
4248
4249@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4250
4251Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4252The @var{id} parameter is a unique ID that will be used to reference this
4253cryptodev backend from the @option{virtio-crypto} device.
4254The chardev should be a unix domain socket backed one. The vhost-user uses
4255a specifically defined protocol to pass vhost ioctl replacement messages
4256to an application on the other end of the socket.
4257The @var{queues} parameter is optional, which specify the queue number
4258of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4259
4260@example
4261
4262 # qemu-system-x86_64 \
4263   [...] \
4264       -chardev socket,id=chardev0,path=/path/to/socket \
4265       -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4266       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4267   [...]
4268@end example
4269
4270@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4271@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4272
4273Defines a secret to store a password, encryption key, or some other sensitive
4274data. The sensitive data can either be passed directly via the @var{data}
4275parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4276parameter is insecure unless the sensitive data is encrypted.
4277
4278The sensitive data can be provided in raw format (the default), or base64.
4279When encoded as JSON, the raw format only supports valid UTF-8 characters,
4280so base64 is recommended for sending binary data. QEMU will convert from
4281which ever format is provided to the format it needs internally. eg, an
4282RBD password can be provided in raw format, even though it will be base64
4283encoded when passed onto the RBD sever.
4284
4285For added protection, it is possible to encrypt the data associated with
4286a secret using the AES-256-CBC cipher. Use of encryption is indicated
4287by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4288parameter provides the ID of a previously defined secret that contains
4289the AES-256 decryption key. This key should be 32-bytes long and be
4290base64 encoded. The @var{iv} parameter provides the random initialization
4291vector used for encryption of this particular secret and should be a
4292base64 encrypted string of the 16-byte IV.
4293
4294The simplest (insecure) usage is to provide the secret inline
4295
4296@example
4297
4298 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4299
4300@end example
4301
4302The simplest secure usage is to provide the secret via a file
4303
4304 # printf "letmein" > mypasswd.txt
4305 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4306
4307For greater security, AES-256-CBC should be used. To illustrate usage,
4308consider the openssl command line tool which can encrypt the data. Note
4309that when encrypting, the plaintext must be padded to the cipher block
4310size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4311
4312First a master key needs to be created in base64 encoding:
4313
4314@example
4315 # openssl rand -base64 32 > key.b64
4316 # KEY=$(base64 -d key.b64 | hexdump  -v -e '/1 "%02X"')
4317@end example
4318
4319Each secret to be encrypted needs to have a random initialization vector
4320generated. These do not need to be kept secret
4321
4322@example
4323 # openssl rand -base64 16 > iv.b64
4324 # IV=$(base64 -d iv.b64 | hexdump  -v -e '/1 "%02X"')
4325@end example
4326
4327The secret to be defined can now be encrypted, in this case we're
4328telling openssl to base64 encode the result, but it could be left
4329as raw bytes if desired.
4330
4331@example
4332 # SECRET=$(printf "letmein" |
4333            openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4334@end example
4335
4336When launching QEMU, create a master secret pointing to @code{key.b64}
4337and specify that to be used to decrypt the user password. Pass the
4338contents of @code{iv.b64} to the second secret
4339
4340@example
4341 # $QEMU \
4342     -object secret,id=secmaster0,format=base64,file=key.b64 \
4343     -object secret,id=sec0,keyid=secmaster0,format=base64,\
4344         data=$SECRET,iv=$(<iv.b64)
4345@end example
4346
4347@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}]
4348
4349Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4350to provide the guest memory encryption support on AMD processors.
4351
4352When memory encryption is enabled, one of the physical address bit (aka the
4353C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4354is used to provide the C-bit position. The C-bit position is Host family dependent
4355hence user must provide this value. On EPYC, the value should be 47.
4356
4357When memory encryption is enabled, we loose certain bits in physical address space.
4358The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4359physical address space. Similar to C-bit, the value is Host family dependent.
4360On EPYC, the value should be 5.
4361
4362The @option{sev-device} provides the device file to use for communicating with
4363the SEV firmware running inside AMD Secure Processor. The default device is
4364'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are
4365created by CCP driver.
4366
4367The @option{policy} provides the guest policy to be enforced by the SEV firmware
4368and restrict what configuration and operational commands can be performed on this
4369guest by the hypervisor. The policy should be provided by the guest owner and is
4370bound to the guest and cannot be changed throughout the lifetime of the guest.
4371The default is 0.
4372
4373If guest @option{policy} allows sharing the key with another SEV guest then
4374@option{handle} can be use to provide handle of the guest from which to share
4375the key.
4376
4377The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4378Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters
4379are used for establishing a cryptographic session with the guest owner to
4380negotiate keys used for attestation. The file must be encoded in base64.
4381
4382e.g to launch a SEV guest
4383@example
4384 # $QEMU \
4385     ......
4386     -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \
4387     -machine ...,memory-encryption=sev0
4388     .....
4389
4390@end example
4391@end table
4392
4393ETEXI
4394
4395
4396HXCOMM This is the last statement. Insert new options before this line!
4397STEXI
4398@end table
4399ETEXI
4400