xref: /qemu/qemu-options.hx (revision 5de7706e)
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][,domainname=domain]\n"
1910    "         [,tftp=dir][,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 domainname=@var{domain}
2139Specifies the client domain name reported by the built-in DHCP server.
2140
2141@item tftp=@var{dir}
2142When using the user mode network stack, activate a built-in TFTP
2143server. The files in @var{dir} will be exposed as the root of a TFTP server.
2144The TFTP client on the guest must be configured in binary mode (use the command
2145@code{bin} of the Unix TFTP client).
2146
2147@item bootfile=@var{file}
2148When using the user mode network stack, broadcast @var{file} as the BOOTP
2149filename. In conjunction with @option{tftp}, this can be used to network boot
2150a guest from a local directory.
2151
2152Example (using pxelinux):
2153@example
2154qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2155    -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2156@end example
2157
2158@item smb=@var{dir}[,smbserver=@var{addr}]
2159When using the user mode network stack, activate a built-in SMB
2160server so that Windows OSes can access to the host files in @file{@var{dir}}
2161transparently. The IP address of the SMB server can be set to @var{addr}. By
2162default the 4th IP in the guest network is used, i.e. x.x.x.4.
2163
2164In the guest Windows OS, the line:
2165@example
216610.0.2.4 smbserver
2167@end example
2168must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2169or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2170
2171Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2172
2173Note that a SAMBA server must be installed on the host OS.
2174
2175@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2176Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2177the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2178@var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2179given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2180be bound to a specific host interface. If no connection type is set, TCP is
2181used. This option can be given multiple times.
2182
2183For example, to redirect host X11 connection from screen 1 to guest
2184screen 0, use the following:
2185
2186@example
2187# on the host
2188qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2189# this host xterm should open in the guest X11 server
2190xterm -display :1
2191@end example
2192
2193To redirect telnet connections from host port 5555 to telnet port on
2194the guest, use the following:
2195
2196@example
2197# on the host
2198qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2199telnet localhost 5555
2200@end example
2201
2202Then when you use on the host @code{telnet localhost 5555}, you
2203connect to the guest telnet server.
2204
2205@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2206@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2207Forward guest TCP connections to the IP address @var{server} on port @var{port}
2208to the character device @var{dev} or to a program executed by @var{cmd:command}
2209which gets spawned for each connection. This option can be given multiple times.
2210
2211You can either use a chardev directly and have that one used throughout QEMU's
2212lifetime, like in the following example:
2213
2214@example
2215# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2216# the guest accesses it
2217qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
2218@end example
2219
2220Or you can execute a command on every TCP connection established by the guest,
2221so that QEMU behaves similar to an inetd process for that virtual server:
2222
2223@example
2224# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2225# and connect the TCP stream to its stdin/stdout
2226qemu-system-i386 -nic  'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2227@end example
2228
2229@end table
2230
2231Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2232processed and applied to -net user. Mixing them with the new configuration
2233syntax gives undefined results. Their use for new applications is discouraged
2234as they will be removed from future versions.
2235
2236@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2237Configure a host TAP network backend with ID @var{id}.
2238
2239Use the network script @var{file} to configure it and the network script
2240@var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2241automatically provides one. The default network configure script is
2242@file{/etc/qemu-ifup} and the default network deconfigure script is
2243@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2244to disable script execution.
2245
2246If running QEMU as an unprivileged user, use the network helper
2247@var{helper} to configure the TAP interface and attach it to the bridge.
2248The default network helper executable is @file{/path/to/qemu-bridge-helper}
2249and the default bridge device is @file{br0}.
2250
2251@option{fd}=@var{h} can be used to specify the handle of an already
2252opened host TAP interface.
2253
2254Examples:
2255
2256@example
2257#launch a QEMU instance with the default network script
2258qemu-system-i386 linux.img -nic tap
2259@end example
2260
2261@example
2262#launch a QEMU instance with two NICs, each one connected
2263#to a TAP device
2264qemu-system-i386 linux.img \
2265        -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2266        -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2267@end example
2268
2269@example
2270#launch a QEMU instance with the default network helper to
2271#connect a TAP device to bridge br0
2272qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \
2273        -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
2274@end example
2275
2276@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2277Connect a host TAP network interface to a host bridge device.
2278
2279Use the network helper @var{helper} to configure the TAP interface and
2280attach it to the bridge. The default network helper executable is
2281@file{/path/to/qemu-bridge-helper} and the default bridge
2282device is @file{br0}.
2283
2284Examples:
2285
2286@example
2287#launch a QEMU instance with the default network helper to
2288#connect a TAP device to bridge br0
2289qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
2290@end example
2291
2292@example
2293#launch a QEMU instance with the default network helper to
2294#connect a TAP device to bridge qemubr0
2295qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
2296@end example
2297
2298@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2299
2300This host network backend can be used to connect the guest's network to
2301another QEMU virtual machine using a TCP socket connection. If @option{listen}
2302is specified, QEMU waits for incoming connections on @var{port}
2303(@var{host} is optional). @option{connect} is used to connect to
2304another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2305specifies an already opened TCP socket.
2306
2307Example:
2308@example
2309# launch a first QEMU instance
2310qemu-system-i386 linux.img \
2311                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2312                 -netdev socket,id=n1,listen=:1234
2313# connect the network of this instance to the network of the first instance
2314qemu-system-i386 linux.img \
2315                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2316                 -netdev socket,id=n2,connect=127.0.0.1:1234
2317@end example
2318
2319@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2320
2321Configure a socket host network backend to share the guest's network traffic
2322with another QEMU virtual machines using a UDP multicast socket, effectively
2323making a bus for every QEMU with same multicast address @var{maddr} and @var{port}.
2324NOTES:
2325@enumerate
2326@item
2327Several QEMU can be running on different hosts and share same bus (assuming
2328correct multicast setup for these hosts).
2329@item
2330mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2331@url{http://user-mode-linux.sf.net}.
2332@item
2333Use @option{fd=h} to specify an already opened UDP multicast socket.
2334@end enumerate
2335
2336Example:
2337@example
2338# launch one QEMU instance
2339qemu-system-i386 linux.img \
2340                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2341                 -netdev socket,id=n1,mcast=230.0.0.1:1234
2342# launch another QEMU instance on same "bus"
2343qemu-system-i386 linux.img \
2344                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2345                 -netdev socket,id=n2,mcast=230.0.0.1:1234
2346# launch yet another QEMU instance on same "bus"
2347qemu-system-i386 linux.img \
2348                 -device e1000,netdev=n3,macaddr=52:54:00:12:34:58 \
2349                 -netdev socket,id=n3,mcast=230.0.0.1:1234
2350@end example
2351
2352Example (User Mode Linux compat.):
2353@example
2354# launch QEMU instance (note mcast address selected is UML's default)
2355qemu-system-i386 linux.img \
2356                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2357                 -netdev socket,id=n1,mcast=239.192.168.1:1102
2358# launch UML
2359/path/to/linux ubd0=/path/to/root_fs eth0=mcast
2360@end example
2361
2362Example (send packets from host's 1.2.3.4):
2363@example
2364qemu-system-i386 linux.img \
2365                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2366                 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2367@end example
2368
2369@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}]
2370Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a
2371popular protocol to transport Ethernet (and other Layer 2) data frames between
2372two systems. It is present in routers, firewalls and the Linux kernel
2373(from version 3.3 onwards).
2374
2375This transport allows a VM to communicate to another VM, router or firewall directly.
2376
2377@table @option
2378@item src=@var{srcaddr}
2379    source address (mandatory)
2380@item dst=@var{dstaddr}
2381    destination address (mandatory)
2382@item udp
2383    select udp encapsulation (default is ip).
2384@item srcport=@var{srcport}
2385    source udp port.
2386@item dstport=@var{dstport}
2387    destination udp port.
2388@item ipv6
2389    force v6, otherwise defaults to v4.
2390@item rxcookie=@var{rxcookie}
2391@itemx txcookie=@var{txcookie}
2392    Cookies are a weak form of security in the l2tpv3 specification.
2393Their function is mostly to prevent misconfiguration. By default they are 32
2394bit.
2395@item cookie64
2396    Set cookie size to 64 bit instead of the default 32
2397@item counter=off
2398    Force a 'cut-down' L2TPv3 with no counter as in
2399draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2400@item pincounter=on
2401    Work around broken counter handling in peer. This may also help on
2402networks which have packet reorder.
2403@item offset=@var{offset}
2404    Add an extra offset between header and data
2405@end table
2406
2407For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2408on the remote Linux host 1.2.3.4:
2409@example
2410# Setup tunnel on linux host using raw ip as encapsulation
2411# on 1.2.3.4
2412ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2413    encap udp udp_sport 16384 udp_dport 16384
2414ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2415    0xFFFFFFFF peer_session_id 0xFFFFFFFF
2416ifconfig vmtunnel0 mtu 1500
2417ifconfig vmtunnel0 up
2418brctl addif br-lan vmtunnel0
2419
2420
2421# on 4.3.2.1
2422# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2423
2424qemu-system-i386 linux.img -device e1000,netdev=n1 \
2425    -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2426
2427@end example
2428
2429@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2430Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and
2431listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2432and MODE @var{octalmode} to change default ownership and permissions for
2433communication port. This option is only available if QEMU has been compiled
2434with vde support enabled.
2435
2436Example:
2437@example
2438# launch vde switch
2439vde_switch -F -sock /tmp/myswitch
2440# launch QEMU instance
2441qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch
2442@end example
2443
2444@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2445
2446Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2447be a unix domain socket backed one. The vhost-user uses a specifically defined
2448protocol to pass vhost ioctl replacement messages to an application on the other
2449end of the socket. On non-MSIX guests, the feature can be forced with
2450@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2451be created for multiqueue vhost-user.
2452
2453Example:
2454@example
2455qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2456     -numa node,memdev=mem \
2457     -chardev socket,id=chr0,path=/path/to/socket \
2458     -netdev type=vhost-user,id=net0,chardev=chr0 \
2459     -device virtio-net-pci,netdev=net0
2460@end example
2461
2462@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2463
2464Create a hub port on the emulated hub with ID @var{hubid}.
2465
2466The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2467single netdev. Alternatively, you can also connect the hubport to another
2468netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option.
2469
2470@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2471@findex -net
2472Legacy option to configure or create an on-board (or machine default) Network
2473Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e.
2474the default hub), or to the netdev @var{nd}.
2475The NIC is an e1000 by default on the PC target. Optionally, the MAC address
2476can be changed to @var{mac}, the device address set to @var{addr} (PCI cards
2477only), and a @var{name} can be assigned for use in monitor commands.
2478Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2479that the card should have; this option currently only affects virtio cards; set
2480@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2481NIC is created.  QEMU can emulate several different models of network card.
2482Use @code{-net nic,model=help} for a list of available devices for your target.
2483
2484@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}]
2485Configure a host network backend (with the options corresponding to the same
2486@option{-netdev} option) and connect it to the emulated hub 0 (the default
2487hub). Use @var{name} to specify the name of the hub port.
2488ETEXI
2489
2490STEXI
2491@end table
2492ETEXI
2493DEFHEADING()
2494
2495DEFHEADING(Character device options:)
2496
2497DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2498    "-chardev help\n"
2499    "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2500    "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2501    "         [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2502    "         [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2503    "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2504    "         [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2505    "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2506    "         [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2507    "         [,logfile=PATH][,logappend=on|off]\n"
2508    "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2509    "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2510    "         [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2511    "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2512    "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2513    "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2514#ifdef _WIN32
2515    "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2516    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2517#else
2518    "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2519    "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2520#endif
2521#ifdef CONFIG_BRLAPI
2522    "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2523#endif
2524#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2525        || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2526    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2527    "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2528#endif
2529#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2530    "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2531    "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2532#endif
2533#if defined(CONFIG_SPICE)
2534    "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2535    "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2536#endif
2537    , QEMU_ARCH_ALL
2538)
2539
2540STEXI
2541
2542The general form of a character device option is:
2543@table @option
2544@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2545@findex -chardev
2546Backend is one of:
2547@option{null},
2548@option{socket},
2549@option{udp},
2550@option{msmouse},
2551@option{vc},
2552@option{ringbuf},
2553@option{file},
2554@option{pipe},
2555@option{console},
2556@option{serial},
2557@option{pty},
2558@option{stdio},
2559@option{braille},
2560@option{tty},
2561@option{parallel},
2562@option{parport},
2563@option{spicevmc},
2564@option{spiceport}.
2565The specific backend will determine the applicable options.
2566
2567Use @code{-chardev help} to print all available chardev backend types.
2568
2569All devices must have an id, which can be any string up to 127 characters long.
2570It is used to uniquely identify this device in other command line directives.
2571
2572A character device may be used in multiplexing mode by multiple front-ends.
2573Specify @option{mux=on} to enable this mode.
2574A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2575backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2576If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2577create a multiplexer with your specified ID, and you can then configure multiple
2578front ends to use that chardev ID for their input/output. Up to four different
2579front ends can be connected to a single multiplexed chardev. (Without
2580multiplexing enabled, a chardev can only be used by a single front end.)
2581For instance you could use this to allow a single stdio chardev to be used by
2582two serial ports and the QEMU monitor:
2583
2584@example
2585-chardev stdio,mux=on,id=char0 \
2586-mon chardev=char0,mode=readline \
2587-serial chardev:char0 \
2588-serial chardev:char0
2589@end example
2590
2591You can have more than one multiplexer in a system configuration; for instance
2592you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2593multiplexed between the QEMU monitor and a parallel port:
2594
2595@example
2596-chardev stdio,mux=on,id=char0 \
2597-mon chardev=char0,mode=readline \
2598-parallel chardev:char0 \
2599-chardev tcp,...,mux=on,id=char1 \
2600-serial chardev:char1 \
2601-serial chardev:char1
2602@end example
2603
2604When you're using a multiplexed character device, some escape sequences are
2605interpreted in the input. @xref{mux_keys, Keys in the character backend
2606multiplexer}.
2607
2608Note that some other command line options may implicitly create multiplexed
2609character backends; for instance @option{-serial mon:stdio} creates a
2610multiplexed stdio backend connected to the serial port and the QEMU monitor,
2611and @option{-nographic} also multiplexes the console and the monitor to
2612stdio.
2613
2614There is currently no support for multiplexing in the other direction
2615(where a single QEMU front end takes input and output from multiple chardevs).
2616
2617Every backend supports the @option{logfile} option, which supplies the path
2618to a file to record all data transmitted via the backend. The @option{logappend}
2619option controls whether the log file will be truncated or appended to when
2620opened.
2621
2622@end table
2623
2624The available backends are:
2625
2626@table @option
2627@item -chardev null,id=@var{id}
2628A void device. This device will not emit any data, and will drop any data it
2629receives. The null backend does not take any options.
2630
2631@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2632
2633Create a two-way stream socket, which can be either a TCP or a unix socket. A
2634unix socket will be created if @option{path} is specified. Behaviour is
2635undefined if TCP options are specified for a unix socket.
2636
2637@option{server} specifies that the socket shall be a listening socket.
2638
2639@option{nowait} specifies that QEMU should not block waiting for a client to
2640connect to a listening socket.
2641
2642@option{telnet} specifies that traffic on the socket should interpret telnet
2643escape sequences.
2644
2645@option{reconnect} sets the timeout for reconnecting on non-server sockets when
2646the remote end goes away.  qemu will delay this many seconds and then attempt
2647to reconnect.  Zero disables reconnecting, and is the default.
2648
2649@option{tls-creds} requests enablement of the TLS protocol for encryption,
2650and specifies the id of the TLS credentials to use for the handshake. The
2651credentials must be previously created with the @option{-object tls-creds}
2652argument.
2653
2654TCP and unix socket options are given below:
2655
2656@table @option
2657
2658@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2659
2660@option{host} for a listening socket specifies the local address to be bound.
2661For a connecting socket species the remote host to connect to. @option{host} is
2662optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2663
2664@option{port} for a listening socket specifies the local port to be bound. For a
2665connecting socket specifies the port on the remote host to connect to.
2666@option{port} can be given as either a port number or a service name.
2667@option{port} is required.
2668
2669@option{to} is only relevant to listening sockets. If it is specified, and
2670@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2671to and including @option{to} until it succeeds. @option{to} must be specified
2672as a port number.
2673
2674@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2675If neither is specified the socket may use either protocol.
2676
2677@option{nodelay} disables the Nagle algorithm.
2678
2679@item unix options: path=@var{path}
2680
2681@option{path} specifies the local path of the unix socket. @option{path} is
2682required.
2683
2684@end table
2685
2686@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2687
2688Sends all traffic from the guest to a remote host over UDP.
2689
2690@option{host} specifies the remote host to connect to. If not specified it
2691defaults to @code{localhost}.
2692
2693@option{port} specifies the port on the remote host to connect to. @option{port}
2694is required.
2695
2696@option{localaddr} specifies the local address to bind to. If not specified it
2697defaults to @code{0.0.0.0}.
2698
2699@option{localport} specifies the local port to bind to. If not specified any
2700available local port will be used.
2701
2702@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2703If neither is specified the device may use either protocol.
2704
2705@item -chardev msmouse,id=@var{id}
2706
2707Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2708take any options.
2709
2710@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2711
2712Connect to a QEMU text console. @option{vc} may optionally be given a specific
2713size.
2714
2715@option{width} and @option{height} specify the width and height respectively of
2716the console, in pixels.
2717
2718@option{cols} and @option{rows} specify that the console be sized to fit a text
2719console with the given dimensions.
2720
2721@item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2722
2723Create a ring buffer with fixed size @option{size}.
2724@var{size} must be a power of two and defaults to @code{64K}.
2725
2726@item -chardev file,id=@var{id},path=@var{path}
2727
2728Log all traffic received from the guest to a file.
2729
2730@option{path} specifies the path of the file to be opened. This file will be
2731created if it does not already exist, and overwritten if it does. @option{path}
2732is required.
2733
2734@item -chardev pipe,id=@var{id},path=@var{path}
2735
2736Create a two-way connection to the guest. The behaviour differs slightly between
2737Windows hosts and other hosts:
2738
2739On Windows, a single duplex pipe will be created at
2740@file{\\.pipe\@option{path}}.
2741
2742On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2743@file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2744received by the guest. Data written by the guest can be read from
2745@file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2746be present.
2747
2748@option{path} forms part of the pipe path as described above. @option{path} is
2749required.
2750
2751@item -chardev console,id=@var{id}
2752
2753Send traffic from the guest to QEMU's standard output. @option{console} does not
2754take any options.
2755
2756@option{console} is only available on Windows hosts.
2757
2758@item -chardev serial,id=@var{id},path=@option{path}
2759
2760Send traffic from the guest to a serial device on the host.
2761
2762On Unix hosts serial will actually accept any tty device,
2763not only serial lines.
2764
2765@option{path} specifies the name of the serial device to open.
2766
2767@item -chardev pty,id=@var{id}
2768
2769Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2770not take any options.
2771
2772@option{pty} is not available on Windows hosts.
2773
2774@item -chardev stdio,id=@var{id}[,signal=on|off]
2775Connect to standard input and standard output of the QEMU process.
2776
2777@option{signal} controls if signals are enabled on the terminal, that includes
2778exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2779default, use @option{signal=off} to disable it.
2780
2781@item -chardev braille,id=@var{id}
2782
2783Connect to a local BrlAPI server. @option{braille} does not take any options.
2784
2785@item -chardev tty,id=@var{id},path=@var{path}
2786
2787@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2788DragonFlyBSD hosts.  It is an alias for @option{serial}.
2789
2790@option{path} specifies the path to the tty. @option{path} is required.
2791
2792@item -chardev parallel,id=@var{id},path=@var{path}
2793@itemx -chardev parport,id=@var{id},path=@var{path}
2794
2795@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2796
2797Connect to a local parallel port.
2798
2799@option{path} specifies the path to the parallel port device. @option{path} is
2800required.
2801
2802@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2803
2804@option{spicevmc} is only available when spice support is built in.
2805
2806@option{debug} debug level for spicevmc
2807
2808@option{name} name of spice channel to connect to
2809
2810Connect to a spice virtual machine channel, such as vdiport.
2811
2812@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2813
2814@option{spiceport} is only available when spice support is built in.
2815
2816@option{debug} debug level for spicevmc
2817
2818@option{name} name of spice port to connect to
2819
2820Connect to a spice port, allowing a Spice client to handle the traffic
2821identified by a name (preferably a fqdn).
2822ETEXI
2823
2824STEXI
2825@end table
2826ETEXI
2827DEFHEADING()
2828
2829DEFHEADING(Bluetooth(R) options:)
2830STEXI
2831@table @option
2832ETEXI
2833
2834DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2835    "-bt hci,null    dumb bluetooth HCI - doesn't respond to commands\n" \
2836    "-bt hci,host[:id]\n" \
2837    "                use host's HCI with the given name\n" \
2838    "-bt hci[,vlan=n]\n" \
2839    "                emulate a standard HCI in virtual scatternet 'n'\n" \
2840    "-bt vhci[,vlan=n]\n" \
2841    "                add host computer to virtual scatternet 'n' using VHCI\n" \
2842    "-bt device:dev[,vlan=n]\n" \
2843    "                emulate a bluetooth device 'dev' in scatternet 'n'\n",
2844    QEMU_ARCH_ALL)
2845STEXI
2846@item -bt hci[...]
2847@findex -bt
2848Defines the function of the corresponding Bluetooth HCI.  -bt options
2849are matched with the HCIs present in the chosen machine type.  For
2850example when emulating a machine with only one HCI built into it, only
2851the first @code{-bt hci[...]} option is valid and defines the HCI's
2852logic.  The Transport Layer is decided by the machine type.  Currently
2853the machines @code{n800} and @code{n810} have one HCI and all other
2854machines have none.
2855
2856@anchor{bt-hcis}
2857The following three types are recognized:
2858
2859@table @option
2860@item -bt hci,null
2861(default) The corresponding Bluetooth HCI assumes no internal logic
2862and will not respond to any HCI commands or emit events.
2863
2864@item -bt hci,host[:@var{id}]
2865(@code{bluez} only) The corresponding HCI passes commands / events
2866to / from the physical HCI identified by the name @var{id} (default:
2867@code{hci0}) on the computer running QEMU.  Only available on @code{bluez}
2868capable systems like Linux.
2869
2870@item -bt hci[,vlan=@var{n}]
2871Add a virtual, standard HCI that will participate in the Bluetooth
2872scatternet @var{n} (default @code{0}).  Similarly to @option{-net}
2873VLANs, devices inside a bluetooth network @var{n} can only communicate
2874with other devices in the same network (scatternet).
2875@end table
2876
2877@item -bt vhci[,vlan=@var{n}]
2878(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2879to the host bluetooth stack instead of to the emulated target.  This
2880allows the host and target machines to participate in a common scatternet
2881and communicate.  Requires the Linux @code{vhci} driver installed.  Can
2882be used as following:
2883
2884@example
2885qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2886@end example
2887
2888@item -bt device:@var{dev}[,vlan=@var{n}]
2889Emulate a bluetooth device @var{dev} and place it in network @var{n}
2890(default @code{0}).  QEMU can only emulate one type of bluetooth devices
2891currently:
2892
2893@table @option
2894@item keyboard
2895Virtual wireless keyboard implementing the HIDP bluetooth profile.
2896@end table
2897ETEXI
2898
2899STEXI
2900@end table
2901ETEXI
2902DEFHEADING()
2903
2904#ifdef CONFIG_TPM
2905DEFHEADING(TPM device options:)
2906
2907DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2908    "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2909    "                use path to provide path to a character device; default is /dev/tpm0\n"
2910    "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2911    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2912    "-tpmdev emulator,id=id,chardev=dev\n"
2913    "                configure the TPM device using chardev backend\n",
2914    QEMU_ARCH_ALL)
2915STEXI
2916
2917The general form of a TPM device option is:
2918@table @option
2919
2920@item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2921@findex -tpmdev
2922
2923The specific backend type will determine the applicable options.
2924The @code{-tpmdev} option creates the TPM backend and requires a
2925@code{-device} option that specifies the TPM frontend interface model.
2926
2927Use @code{-tpmdev help} to print all available TPM backend types.
2928
2929@end table
2930
2931The available backends are:
2932
2933@table @option
2934
2935@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2936
2937(Linux-host only) Enable access to the host's TPM using the passthrough
2938driver.
2939
2940@option{path} specifies the path to the host's TPM device, i.e., on
2941a Linux host this would be @code{/dev/tpm0}.
2942@option{path} is optional and by default @code{/dev/tpm0} is used.
2943
2944@option{cancel-path} specifies the path to the host TPM device's sysfs
2945entry allowing for cancellation of an ongoing TPM command.
2946@option{cancel-path} is optional and by default QEMU will search for the
2947sysfs entry to use.
2948
2949Some notes about using the host's TPM with the passthrough driver:
2950
2951The TPM device accessed by the passthrough driver must not be
2952used by any other application on the host.
2953
2954Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2955the VM's firmware (BIOS/UEFI) will not be able to initialize the
2956TPM again and may therefore not show a TPM-specific menu that would
2957otherwise allow the user to configure the TPM, e.g., allow the user to
2958enable/disable or activate/deactivate the TPM.
2959Further, if TPM ownership is released from within a VM then the host's TPM
2960will get disabled and deactivated. To enable and activate the
2961TPM again afterwards, the host has to be rebooted and the user is
2962required to enter the firmware's menu to enable and activate the TPM.
2963If the TPM is left disabled and/or deactivated most TPM commands will fail.
2964
2965To create a passthrough TPM use the following two options:
2966@example
2967-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2968@end example
2969Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2970@code{tpmdev=tpm0} in the device option.
2971
2972@item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2973
2974(Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2975chardev backend.
2976
2977@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2978
2979To create a TPM emulator backend device with chardev socket backend:
2980@example
2981
2982-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2983
2984@end example
2985
2986ETEXI
2987
2988STEXI
2989@end table
2990ETEXI
2991DEFHEADING()
2992
2993#endif
2994
2995DEFHEADING(Linux/Multiboot boot specific:)
2996STEXI
2997
2998When using these options, you can use a given Linux or Multiboot
2999kernel without installing it in the disk image. It can be useful
3000for easier testing of various kernels.
3001
3002@table @option
3003ETEXI
3004
3005DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
3006    "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
3007STEXI
3008@item -kernel @var{bzImage}
3009@findex -kernel
3010Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
3011or in multiboot format.
3012ETEXI
3013
3014DEF("append", HAS_ARG, QEMU_OPTION_append, \
3015    "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
3016STEXI
3017@item -append @var{cmdline}
3018@findex -append
3019Use @var{cmdline} as kernel command line
3020ETEXI
3021
3022DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
3023           "-initrd file    use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
3024STEXI
3025@item -initrd @var{file}
3026@findex -initrd
3027Use @var{file} as initial ram disk.
3028
3029@item -initrd "@var{file1} arg=foo,@var{file2}"
3030
3031This syntax is only available with multiboot.
3032
3033Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3034first module.
3035ETEXI
3036
3037DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
3038    "-dtb    file    use 'file' as device tree image\n", QEMU_ARCH_ALL)
3039STEXI
3040@item -dtb @var{file}
3041@findex -dtb
3042Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3043on boot.
3044ETEXI
3045
3046STEXI
3047@end table
3048ETEXI
3049DEFHEADING()
3050
3051DEFHEADING(Debug/Expert options:)
3052STEXI
3053@table @option
3054ETEXI
3055
3056DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3057    "-fw_cfg [name=]<name>,file=<file>\n"
3058    "                add named fw_cfg entry with contents from file\n"
3059    "-fw_cfg [name=]<name>,string=<str>\n"
3060    "                add named fw_cfg entry with contents from string\n",
3061    QEMU_ARCH_ALL)
3062STEXI
3063
3064@item -fw_cfg [name=]@var{name},file=@var{file}
3065@findex -fw_cfg
3066Add named fw_cfg entry with contents from file @var{file}.
3067
3068@item -fw_cfg [name=]@var{name},string=@var{str}
3069Add named fw_cfg entry with contents from string @var{str}.
3070
3071The terminating NUL character of the contents of @var{str} will not be
3072included as part of the fw_cfg item data. To insert contents with
3073embedded NUL characters, you have to use the @var{file} parameter.
3074
3075The fw_cfg entries are passed by QEMU through to the guest.
3076
3077Example:
3078@example
3079    -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3080@end example
3081creates an fw_cfg entry named opt/com.mycompany/blob with contents
3082from ./my_blob.bin.
3083
3084ETEXI
3085
3086DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3087    "-serial dev     redirect the serial port to char device 'dev'\n",
3088    QEMU_ARCH_ALL)
3089STEXI
3090@item -serial @var{dev}
3091@findex -serial
3092Redirect the virtual serial port to host character device
3093@var{dev}. The default device is @code{vc} in graphical mode and
3094@code{stdio} in non graphical mode.
3095
3096This option can be used several times to simulate up to 4 serial
3097ports.
3098
3099Use @code{-serial none} to disable all serial ports.
3100
3101Available character devices are:
3102@table @option
3103@item vc[:@var{W}x@var{H}]
3104Virtual console. Optionally, a width and height can be given in pixel with
3105@example
3106vc:800x600
3107@end example
3108It is also possible to specify width or height in characters:
3109@example
3110vc:80Cx24C
3111@end example
3112@item pty
3113[Linux only] Pseudo TTY (a new PTY is automatically allocated)
3114@item none
3115No device is allocated.
3116@item null
3117void device
3118@item chardev:@var{id}
3119Use a named character device defined with the @code{-chardev} option.
3120@item /dev/XXX
3121[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3122parameters are set according to the emulated ones.
3123@item /dev/parport@var{N}
3124[Linux only, parallel port only] Use host parallel port
3125@var{N}. Currently SPP and EPP parallel port features can be used.
3126@item file:@var{filename}
3127Write output to @var{filename}. No character can be read.
3128@item stdio
3129[Unix only] standard input/output
3130@item pipe:@var{filename}
3131name pipe @var{filename}
3132@item COM@var{n}
3133[Windows only] Use host serial port @var{n}
3134@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3135This implements UDP Net Console.
3136When @var{remote_host} or @var{src_ip} are not specified
3137they default to @code{0.0.0.0}.
3138When not using a specified @var{src_port} a random port is automatically chosen.
3139
3140If you just want a simple readonly console you can use @code{netcat} or
3141@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3142@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3143will appear in the netconsole session.
3144
3145If you plan to send characters back via netconsole or you want to stop
3146and start QEMU a lot of times, you should have QEMU use the same
3147source port each time by using something like @code{-serial
3148udp::4555@@:4556} to QEMU. Another approach is to use a patched
3149version of netcat which can listen to a TCP port and send and receive
3150characters via udp.  If you have a patched version of netcat which
3151activates telnet remote echo and single char transfer, then you can
3152use the following options to set up a netcat redirector to allow
3153telnet on port 5555 to access the QEMU port.
3154@table @code
3155@item QEMU Options:
3156-serial udp::4555@@:4556
3157@item netcat options:
3158-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3159@item telnet options:
3160localhost 5555
3161@end table
3162
3163@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3164The TCP Net Console has two modes of operation.  It can send the serial
3165I/O to a location or wait for a connection from a location.  By default
3166the TCP Net Console is sent to @var{host} at the @var{port}.  If you use
3167the @var{server} option QEMU will wait for a client socket application
3168to connect to the port before continuing, unless the @code{nowait}
3169option was specified.  The @code{nodelay} option disables the Nagle buffering
3170algorithm.  The @code{reconnect} option only applies if @var{noserver} is
3171set, if the connection goes down it will attempt to reconnect at the
3172given interval.  If @var{host} is omitted, 0.0.0.0 is assumed. Only
3173one TCP connection at a time is accepted. You can use @code{telnet} to
3174connect to the corresponding character device.
3175@table @code
3176@item Example to send tcp console to 192.168.0.2 port 4444
3177-serial tcp:192.168.0.2:4444
3178@item Example to listen and wait on port 4444 for connection
3179-serial tcp::4444,server
3180@item Example to not wait and listen on ip 192.168.0.100 port 4444
3181-serial tcp:192.168.0.100:4444,server,nowait
3182@end table
3183
3184@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3185The telnet protocol is used instead of raw tcp sockets.  The options
3186work the same as if you had specified @code{-serial tcp}.  The
3187difference is that the port acts like a telnet server or client using
3188telnet option negotiation.  This will also allow you to send the
3189MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3190sequence.  Typically in unix telnet you do it with Control-] and then
3191type "send break" followed by pressing the enter key.
3192
3193@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3194A unix domain socket is used instead of a tcp socket.  The option works the
3195same as if you had specified @code{-serial tcp} except the unix domain socket
3196@var{path} is used for connections.
3197
3198@item mon:@var{dev_string}
3199This is a special option to allow the monitor to be multiplexed onto
3200another serial port.  The monitor is accessed with key sequence of
3201@key{Control-a} and then pressing @key{c}.
3202@var{dev_string} should be any one of the serial devices specified
3203above.  An example to multiplex the monitor onto a telnet server
3204listening on port 4444 would be:
3205@table @code
3206@item -serial mon:telnet::4444,server,nowait
3207@end table
3208When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3209QEMU any more but will be passed to the guest instead.
3210
3211@item braille
3212Braille device.  This will use BrlAPI to display the braille output on a real
3213or fake device.
3214
3215@item msmouse
3216Three button serial mouse. Configure the guest to use Microsoft protocol.
3217@end table
3218ETEXI
3219
3220DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3221    "-parallel dev   redirect the parallel port to char device 'dev'\n",
3222    QEMU_ARCH_ALL)
3223STEXI
3224@item -parallel @var{dev}
3225@findex -parallel
3226Redirect the virtual parallel port to host device @var{dev} (same
3227devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3228be used to use hardware devices connected on the corresponding host
3229parallel port.
3230
3231This option can be used several times to simulate up to 3 parallel
3232ports.
3233
3234Use @code{-parallel none} to disable all parallel ports.
3235ETEXI
3236
3237DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3238    "-monitor dev    redirect the monitor to char device 'dev'\n",
3239    QEMU_ARCH_ALL)
3240STEXI
3241@item -monitor @var{dev}
3242@findex -monitor
3243Redirect the monitor to host device @var{dev} (same devices as the
3244serial port).
3245The default device is @code{vc} in graphical mode and @code{stdio} in
3246non graphical mode.
3247Use @code{-monitor none} to disable the default monitor.
3248ETEXI
3249DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3250    "-qmp dev        like -monitor but opens in 'control' mode\n",
3251    QEMU_ARCH_ALL)
3252STEXI
3253@item -qmp @var{dev}
3254@findex -qmp
3255Like -monitor but opens in 'control' mode.
3256ETEXI
3257DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3258    "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3259    QEMU_ARCH_ALL)
3260STEXI
3261@item -qmp-pretty @var{dev}
3262@findex -qmp-pretty
3263Like -qmp but uses pretty JSON formatting.
3264ETEXI
3265
3266DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3267    "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3268STEXI
3269@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3270@findex -mon
3271Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3272easing human reading and debugging.
3273ETEXI
3274
3275DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3276    "-debugcon dev   redirect the debug console to char device 'dev'\n",
3277    QEMU_ARCH_ALL)
3278STEXI
3279@item -debugcon @var{dev}
3280@findex -debugcon
3281Redirect the debug console to host device @var{dev} (same devices as the
3282serial port).  The debug console is an I/O port which is typically port
32830xe9; writing to that I/O port sends output to this device.
3284The default device is @code{vc} in graphical mode and @code{stdio} in
3285non graphical mode.
3286ETEXI
3287
3288DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3289    "-pidfile file   write PID to 'file'\n", QEMU_ARCH_ALL)
3290STEXI
3291@item -pidfile @var{file}
3292@findex -pidfile
3293Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3294from a script.
3295ETEXI
3296
3297DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3298    "-singlestep     always run in singlestep mode\n", QEMU_ARCH_ALL)
3299STEXI
3300@item -singlestep
3301@findex -singlestep
3302Run the emulation in single step mode.
3303ETEXI
3304
3305DEF("preconfig", 0, QEMU_OPTION_preconfig, \
3306    "--preconfig     pause QEMU before machine is initialized\n",
3307    QEMU_ARCH_ALL)
3308STEXI
3309@item --preconfig
3310@findex --preconfig
3311Pause QEMU for interactive configuration before the machine is created,
3312which allows querying and configuring properties that will affect
3313machine initialization. Use the QMP command 'exit-preconfig' to exit
3314the preconfig state and move to the next state (ie. run guest if -S
3315isn't used or pause the second time if -S is used).
3316ETEXI
3317
3318DEF("S", 0, QEMU_OPTION_S, \
3319    "-S              freeze CPU at startup (use 'c' to start execution)\n",
3320    QEMU_ARCH_ALL)
3321STEXI
3322@item -S
3323@findex -S
3324Do not start CPU at startup (you must type 'c' in the monitor).
3325ETEXI
3326
3327DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3328    "-realtime [mlock=on|off]\n"
3329    "                run qemu with realtime features\n"
3330    "                mlock=on|off controls mlock support (default: on)\n",
3331    QEMU_ARCH_ALL)
3332STEXI
3333@item -realtime mlock=on|off
3334@findex -realtime
3335Run qemu with realtime features.
3336mlocking qemu and guest memory can be enabled via @option{mlock=on}
3337(enabled by default).
3338ETEXI
3339
3340DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3341    "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3342STEXI
3343@item -gdb @var{dev}
3344@findex -gdb
3345Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3346connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3347stdio are reasonable use case. The latter is allowing to start QEMU from
3348within gdb and establish the connection via a pipe:
3349@example
3350(gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3351@end example
3352ETEXI
3353
3354DEF("s", 0, QEMU_OPTION_s, \
3355    "-s              shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3356    QEMU_ARCH_ALL)
3357STEXI
3358@item -s
3359@findex -s
3360Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3361(@pxref{gdb_usage}).
3362ETEXI
3363
3364DEF("d", HAS_ARG, QEMU_OPTION_d, \
3365    "-d item1,...    enable logging of specified items (use '-d help' for a list of log items)\n",
3366    QEMU_ARCH_ALL)
3367STEXI
3368@item -d @var{item1}[,...]
3369@findex -d
3370Enable logging of specified items. Use '-d help' for a list of log items.
3371ETEXI
3372
3373DEF("D", HAS_ARG, QEMU_OPTION_D, \
3374    "-D logfile      output log to logfile (default stderr)\n",
3375    QEMU_ARCH_ALL)
3376STEXI
3377@item -D @var{logfile}
3378@findex -D
3379Output log in @var{logfile} instead of to stderr
3380ETEXI
3381
3382DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3383    "-dfilter range,..  filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3384    QEMU_ARCH_ALL)
3385STEXI
3386@item -dfilter @var{range1}[,...]
3387@findex -dfilter
3388Filter debug output to that relevant to a range of target addresses. The filter
3389spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3390@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3391addresses and sizes required. For example:
3392@example
3393    -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3394@end example
3395Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3396the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3397block starting at 0xffffffc00005f000.
3398ETEXI
3399
3400DEF("L", HAS_ARG, QEMU_OPTION_L, \
3401    "-L path         set the directory for the BIOS, VGA BIOS and keymaps\n",
3402    QEMU_ARCH_ALL)
3403STEXI
3404@item -L  @var{path}
3405@findex -L
3406Set the directory for the BIOS, VGA BIOS and keymaps.
3407
3408To list all the data directories, use @code{-L help}.
3409ETEXI
3410
3411DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3412    "-bios file      set the filename for the BIOS\n", QEMU_ARCH_ALL)
3413STEXI
3414@item -bios @var{file}
3415@findex -bios
3416Set the filename for the BIOS.
3417ETEXI
3418
3419DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3420    "-enable-kvm     enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3421STEXI
3422@item -enable-kvm
3423@findex -enable-kvm
3424Enable KVM full virtualization support. This option is only available
3425if KVM support is enabled when compiling.
3426ETEXI
3427
3428DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3429    "-enable-hax     enable HAX virtualization support\n", QEMU_ARCH_I386)
3430STEXI
3431@item -enable-hax
3432@findex -enable-hax
3433Enable HAX (Hardware-based Acceleration eXecution) support. This option
3434is only available if HAX support is enabled when compiling. HAX is only
3435applicable to MAC and Windows platform, and thus does not conflict with
3436KVM.
3437ETEXI
3438
3439DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3440    "-xen-domid id   specify xen guest domain id\n", QEMU_ARCH_ALL)
3441DEF("xen-create", 0, QEMU_OPTION_xen_create,
3442    "-xen-create     create domain using xen hypercalls, bypassing xend\n"
3443    "                warning: should not be used when xend is in use\n",
3444    QEMU_ARCH_ALL)
3445DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3446    "-xen-attach     attach to existing xen domain\n"
3447    "                xend will use this when starting QEMU\n",
3448    QEMU_ARCH_ALL)
3449DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3450    "-xen-domid-restrict     restrict set of available xen operations\n"
3451    "                        to specified domain id. (Does not affect\n"
3452    "                        xenpv machine type).\n",
3453    QEMU_ARCH_ALL)
3454STEXI
3455@item -xen-domid @var{id}
3456@findex -xen-domid
3457Specify xen guest domain @var{id} (XEN only).
3458@item -xen-create
3459@findex -xen-create
3460Create domain using xen hypercalls, bypassing xend.
3461Warning: should not be used when xend is in use (XEN only).
3462@item -xen-attach
3463@findex -xen-attach
3464Attach to existing xen domain.
3465xend will use this when starting QEMU (XEN only).
3466@findex -xen-domid-restrict
3467Restrict set of available xen operations to specified domain id (XEN only).
3468ETEXI
3469
3470DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3471    "-no-reboot      exit instead of rebooting\n", QEMU_ARCH_ALL)
3472STEXI
3473@item -no-reboot
3474@findex -no-reboot
3475Exit instead of rebooting.
3476ETEXI
3477
3478DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3479    "-no-shutdown    stop before shutdown\n", QEMU_ARCH_ALL)
3480STEXI
3481@item -no-shutdown
3482@findex -no-shutdown
3483Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3484This allows for instance switching to monitor to commit changes to the
3485disk image.
3486ETEXI
3487
3488DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3489    "-loadvm [tag|id]\n" \
3490    "                start right away with a saved state (loadvm in monitor)\n",
3491    QEMU_ARCH_ALL)
3492STEXI
3493@item -loadvm @var{file}
3494@findex -loadvm
3495Start right away with a saved state (@code{loadvm} in monitor)
3496ETEXI
3497
3498#ifndef _WIN32
3499DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3500    "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3501#endif
3502STEXI
3503@item -daemonize
3504@findex -daemonize
3505Daemonize the QEMU process after initialization.  QEMU will not detach from
3506standard IO until it is ready to receive connections on any of its devices.
3507This option is a useful way for external programs to launch QEMU without having
3508to cope with initialization race conditions.
3509ETEXI
3510
3511DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3512    "-option-rom rom load a file, rom, into the option ROM space\n",
3513    QEMU_ARCH_ALL)
3514STEXI
3515@item -option-rom @var{file}
3516@findex -option-rom
3517Load the contents of @var{file} as an option ROM.
3518This option is useful to load things like EtherBoot.
3519ETEXI
3520
3521HXCOMM Silently ignored for compatibility
3522DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3523
3524HXCOMM Options deprecated by -rtc
3525DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3526DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3527
3528DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3529    "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3530    "                set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3531    QEMU_ARCH_ALL)
3532
3533STEXI
3534
3535@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3536@findex -rtc
3537Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3538UTC or local time, respectively. @code{localtime} is required for correct date in
3539MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3540format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3541
3542By default the RTC is driven by the host system time. This allows using of the
3543RTC as accurate reference clock inside the guest, specifically if the host
3544time is smoothly following an accurate external reference clock, e.g. via NTP.
3545If you want to isolate the guest time from the host, you can set @option{clock}
3546to @code{rt} instead.  To even prevent it from progressing during suspension,
3547you can set it to @code{vm}.
3548
3549Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3550specifically with Windows' ACPI HAL. This option will try to figure out how
3551many timer interrupts were not processed by the Windows guest and will
3552re-inject them.
3553ETEXI
3554
3555DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3556    "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3557    "                enable virtual instruction counter with 2^N clock ticks per\n" \
3558    "                instruction, enable aligning the host and virtual clocks\n" \
3559    "                or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3560STEXI
3561@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3562@findex -icount
3563Enable virtual instruction counter.  The virtual cpu will execute one
3564instruction every 2^@var{N} ns of virtual time.  If @code{auto} is specified
3565then the virtual cpu speed will be automatically adjusted to keep virtual
3566time within a few seconds of real time.
3567
3568When the virtual cpu is sleeping, the virtual time will advance at default
3569speed unless @option{sleep=on|off} is specified.
3570With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3571instantly whenever the virtual cpu goes to sleep mode and will not advance
3572if no timer is enabled. This behavior give deterministic execution times from
3573the guest point of view.
3574
3575Note that while this option can give deterministic behavior, it does not
3576provide cycle accurate emulation.  Modern CPUs contain superscalar out of
3577order cores with complex cache hierarchies.  The number of instructions
3578executed often has little or no correlation with actual performance.
3579
3580@option{align=on} will activate the delay algorithm which will try
3581to synchronise the host clock and the virtual clock. The goal is to
3582have a guest running at the real frequency imposed by the shift option.
3583Whenever the guest clock is behind the host clock and if
3584@option{align=on} is specified then we print a message to the user
3585to inform about the delay.
3586Currently this option does not work when @option{shift} is @code{auto}.
3587Note: The sync algorithm will work for those shift values for which
3588the guest clock runs ahead of the host clock. Typically this happens
3589when the shift value is high (how high depends on the host machine).
3590
3591When @option{rr} option is specified deterministic record/replay is enabled.
3592Replay log is written into @var{filename} file in record mode and
3593read from this file in replay mode.
3594
3595Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3596at the start of execution recording. In replay mode this option is used
3597to load the initial VM state.
3598ETEXI
3599
3600DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3601    "-watchdog model\n" \
3602    "                enable virtual hardware watchdog [default=none]\n",
3603    QEMU_ARCH_ALL)
3604STEXI
3605@item -watchdog @var{model}
3606@findex -watchdog
3607Create a virtual hardware watchdog device.  Once enabled (by a guest
3608action), the watchdog must be periodically polled by an agent inside
3609the guest or else the guest will be restarted. Choose a model for
3610which your guest has drivers.
3611
3612The @var{model} is the model of hardware watchdog to emulate. Use
3613@code{-watchdog help} to list available hardware models. Only one
3614watchdog can be enabled for a guest.
3615
3616The following models may be available:
3617@table @option
3618@item ib700
3619iBASE 700 is a very simple ISA watchdog with a single timer.
3620@item i6300esb
3621Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3622dual-timer watchdog.
3623@item diag288
3624A virtual watchdog for s390x backed by the diagnose 288 hypercall
3625(currently KVM only).
3626@end table
3627ETEXI
3628
3629DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3630    "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3631    "                action when watchdog fires [default=reset]\n",
3632    QEMU_ARCH_ALL)
3633STEXI
3634@item -watchdog-action @var{action}
3635@findex -watchdog-action
3636
3637The @var{action} controls what QEMU will do when the watchdog timer
3638expires.
3639The default is
3640@code{reset} (forcefully reset the guest).
3641Other possible actions are:
3642@code{shutdown} (attempt to gracefully shutdown the guest),
3643@code{poweroff} (forcefully poweroff the guest),
3644@code{inject-nmi} (inject a NMI into the guest),
3645@code{pause} (pause the guest),
3646@code{debug} (print a debug message and continue), or
3647@code{none} (do nothing).
3648
3649Note that the @code{shutdown} action requires that the guest responds
3650to ACPI signals, which it may not be able to do in the sort of
3651situations where the watchdog would have expired, and thus
3652@code{-watchdog-action shutdown} is not recommended for production use.
3653
3654Examples:
3655
3656@table @code
3657@item -watchdog i6300esb -watchdog-action pause
3658@itemx -watchdog ib700
3659@end table
3660ETEXI
3661
3662DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3663    "-echr chr       set terminal escape character instead of ctrl-a\n",
3664    QEMU_ARCH_ALL)
3665STEXI
3666
3667@item -echr @var{numeric_ascii_value}
3668@findex -echr
3669Change the escape character used for switching to the monitor when using
3670monitor and serial sharing.  The default is @code{0x01} when using the
3671@code{-nographic} option.  @code{0x01} is equal to pressing
3672@code{Control-a}.  You can select a different character from the ascii
3673control keys where 1 through 26 map to Control-a through Control-z.  For
3674instance you could use the either of the following to change the escape
3675character to Control-t.
3676@table @code
3677@item -echr 0x14
3678@itemx -echr 20
3679@end table
3680ETEXI
3681
3682DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3683    "-virtioconsole c\n" \
3684    "                set virtio console\n", QEMU_ARCH_ALL)
3685STEXI
3686@item -virtioconsole @var{c}
3687@findex -virtioconsole
3688Set virtio console.
3689This option is deprecated, please use @option{-device virtconsole} instead.
3690ETEXI
3691
3692DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3693    "-show-cursor    show cursor\n", QEMU_ARCH_ALL)
3694STEXI
3695@item -show-cursor
3696@findex -show-cursor
3697Show cursor.
3698ETEXI
3699
3700DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3701    "-tb-size n      set TB size\n", QEMU_ARCH_ALL)
3702STEXI
3703@item -tb-size @var{n}
3704@findex -tb-size
3705Set TB size.
3706ETEXI
3707
3708DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3709    "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3710    "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3711    "-incoming unix:socketpath\n" \
3712    "                prepare for incoming migration, listen on\n" \
3713    "                specified protocol and socket address\n" \
3714    "-incoming fd:fd\n" \
3715    "-incoming exec:cmdline\n" \
3716    "                accept incoming migration on given file descriptor\n" \
3717    "                or from given external command\n" \
3718    "-incoming defer\n" \
3719    "                wait for the URI to be specified via migrate_incoming\n",
3720    QEMU_ARCH_ALL)
3721STEXI
3722@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3723@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3724@findex -incoming
3725Prepare for incoming migration, listen on a given tcp port.
3726
3727@item -incoming unix:@var{socketpath}
3728Prepare for incoming migration, listen on a given unix socket.
3729
3730@item -incoming fd:@var{fd}
3731Accept incoming migration from a given filedescriptor.
3732
3733@item -incoming exec:@var{cmdline}
3734Accept incoming migration as an output from specified external command.
3735
3736@item -incoming defer
3737Wait for the URI to be specified via migrate_incoming.  The monitor can
3738be used to change settings (such as migration parameters) prior to issuing
3739the migrate_incoming to allow the migration to begin.
3740ETEXI
3741
3742DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3743    "-only-migratable     allow only migratable devices\n", QEMU_ARCH_ALL)
3744STEXI
3745@item -only-migratable
3746@findex -only-migratable
3747Only allow migratable devices. Devices will not be allowed to enter an
3748unmigratable state.
3749ETEXI
3750
3751DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3752    "-nodefaults     don't create default devices\n", QEMU_ARCH_ALL)
3753STEXI
3754@item -nodefaults
3755@findex -nodefaults
3756Don't create default devices. Normally, QEMU sets the default devices like serial
3757port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3758CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3759default devices.
3760ETEXI
3761
3762#ifndef _WIN32
3763DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3764    "-chroot dir     chroot to dir just before starting the VM\n",
3765    QEMU_ARCH_ALL)
3766#endif
3767STEXI
3768@item -chroot @var{dir}
3769@findex -chroot
3770Immediately before starting guest execution, chroot to the specified
3771directory.  Especially useful in combination with -runas.
3772ETEXI
3773
3774#ifndef _WIN32
3775DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3776    "-runas user     change to user id user just before starting the VM\n" \
3777    "                user can be numeric uid:gid instead\n",
3778    QEMU_ARCH_ALL)
3779#endif
3780STEXI
3781@item -runas @var{user}
3782@findex -runas
3783Immediately before starting guest execution, drop root privileges, switching
3784to the specified user.
3785ETEXI
3786
3787DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3788    "-prom-env variable=value\n"
3789    "                set OpenBIOS nvram variables\n",
3790    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3791STEXI
3792@item -prom-env @var{variable}=@var{value}
3793@findex -prom-env
3794Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3795ETEXI
3796DEF("semihosting", 0, QEMU_OPTION_semihosting,
3797    "-semihosting    semihosting mode\n",
3798    QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3799    QEMU_ARCH_MIPS)
3800STEXI
3801@item -semihosting
3802@findex -semihosting
3803Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3804ETEXI
3805DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3806    "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3807    "                semihosting configuration\n",
3808QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3809QEMU_ARCH_MIPS)
3810STEXI
3811@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3812@findex -semihosting-config
3813Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3814@table @option
3815@item target=@code{native|gdb|auto}
3816Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3817or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3818during debug sessions and @code{native} otherwise.
3819@item arg=@var{str1},arg=@var{str2},...
3820Allows the user to pass input arguments, and can be used multiple times to build
3821up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3822command line is still supported for backward compatibility. If both the
3823@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3824specified, the former is passed to semihosting as it always takes precedence.
3825@end table
3826ETEXI
3827DEF("old-param", 0, QEMU_OPTION_old_param,
3828    "-old-param      old param mode\n", QEMU_ARCH_ARM)
3829STEXI
3830@item -old-param
3831@findex -old-param (ARM)
3832Old param mode (ARM only).
3833ETEXI
3834
3835DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3836    "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3837    "          [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3838    "                Enable seccomp mode 2 system call filter (default 'off').\n" \
3839    "                use 'obsolete' to allow obsolete system calls that are provided\n" \
3840    "                    by the kernel, but typically no longer used by modern\n" \
3841    "                    C library implementations.\n" \
3842    "                use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3843    "                    its privileges by blacklisting all set*uid|gid system calls.\n" \
3844    "                    The value 'children' will deny set*uid|gid system calls for\n" \
3845    "                    main QEMU process but will allow forks and execves to run unprivileged\n" \
3846    "                use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3847    "                     blacklisting *fork and execve\n" \
3848    "                use 'resourcecontrol' to disable process affinity and schedular priority\n",
3849    QEMU_ARCH_ALL)
3850STEXI
3851@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3852@findex -sandbox
3853Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3854disable it.  The default is 'off'.
3855@table @option
3856@item obsolete=@var{string}
3857Enable Obsolete system calls
3858@item elevateprivileges=@var{string}
3859Disable set*uid|gid system calls
3860@item spawn=@var{string}
3861Disable *fork and execve
3862@item resourcecontrol=@var{string}
3863Disable process affinity and schedular priority
3864@end table
3865ETEXI
3866
3867DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3868    "-readconfig <file>\n", QEMU_ARCH_ALL)
3869STEXI
3870@item -readconfig @var{file}
3871@findex -readconfig
3872Read device configuration from @var{file}. This approach is useful when you want to spawn
3873QEMU process with many command line options but you don't want to exceed the command line
3874character limit.
3875ETEXI
3876DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3877    "-writeconfig <file>\n"
3878    "                read/write config file\n", QEMU_ARCH_ALL)
3879STEXI
3880@item -writeconfig @var{file}
3881@findex -writeconfig
3882Write device configuration to @var{file}. The @var{file} can be either filename to save
3883command line and device configuration into file or dash @code{-}) character to print the
3884output to stdout. This can be later used as input file for @code{-readconfig} option.
3885ETEXI
3886HXCOMM Deprecated, same as -no-user-config
3887DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
3888DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3889    "-no-user-config\n"
3890    "                do not load default user-provided config files at startup\n",
3891    QEMU_ARCH_ALL)
3892STEXI
3893@item -no-user-config
3894@findex -no-user-config
3895The @code{-no-user-config} option makes QEMU not load any of the user-provided
3896config files on @var{sysconfdir}.
3897ETEXI
3898DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3899    "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3900    "                specify tracing options\n",
3901    QEMU_ARCH_ALL)
3902STEXI
3903HXCOMM This line is not accurate, as some sub-options are backend-specific but
3904HXCOMM HX does not support conditional compilation of text.
3905@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3906@findex -trace
3907@include qemu-option-trace.texi
3908ETEXI
3909
3910HXCOMM Internal use
3911DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3912DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3913
3914#ifdef __linux__
3915DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3916    "-enable-fips    enable FIPS 140-2 compliance\n",
3917    QEMU_ARCH_ALL)
3918#endif
3919STEXI
3920@item -enable-fips
3921@findex -enable-fips
3922Enable FIPS 140-2 compliance mode.
3923ETEXI
3924
3925HXCOMM Deprecated by -machine accel=tcg property
3926DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3927
3928DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3929    "-msg timestamp[=on|off]\n"
3930    "                change the format of messages\n"
3931    "                on|off controls leading timestamps (default:on)\n",
3932    QEMU_ARCH_ALL)
3933STEXI
3934@item -msg timestamp[=on|off]
3935@findex -msg
3936prepend a timestamp to each log message.(default:on)
3937ETEXI
3938
3939DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3940    "-dump-vmstate <file>\n"
3941    "                Output vmstate information in JSON format to file.\n"
3942    "                Use the scripts/vmstate-static-checker.py file to\n"
3943    "                check for possible regressions in migration code\n"
3944    "                by comparing two such vmstate dumps.\n",
3945    QEMU_ARCH_ALL)
3946STEXI
3947@item -dump-vmstate @var{file}
3948@findex -dump-vmstate
3949Dump json-encoded vmstate information for current machine type to file
3950in @var{file}
3951ETEXI
3952
3953STEXI
3954@end table
3955ETEXI
3956DEFHEADING()
3957
3958DEFHEADING(Generic object creation:)
3959STEXI
3960@table @option
3961ETEXI
3962
3963DEF("object", HAS_ARG, QEMU_OPTION_object,
3964    "-object TYPENAME[,PROP1=VALUE1,...]\n"
3965    "                create a new object of type TYPENAME setting properties\n"
3966    "                in the order they are specified.  Note that the 'id'\n"
3967    "                property must be set.  These objects are placed in the\n"
3968    "                '/objects' path.\n",
3969    QEMU_ARCH_ALL)
3970STEXI
3971@item -object @var{typename}[,@var{prop1}=@var{value1},...]
3972@findex -object
3973Create a new object of type @var{typename} setting properties
3974in the order they are specified.  Note that the 'id'
3975property must be set.  These objects are placed in the
3976'/objects' path.
3977
3978@table @option
3979
3980@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}
3981
3982Creates a memory file backend object, which can be used to back
3983the guest RAM with huge pages.
3984
3985The @option{id} parameter is a unique ID that will be used to reference this
3986memory region when configuring the @option{-numa} argument.
3987
3988The @option{size} option provides the size of the memory region, and accepts
3989common suffixes, eg @option{500M}.
3990
3991The @option{mem-path} provides the path to either a shared memory or huge page
3992filesystem mount.
3993
3994The @option{share} boolean option determines whether the memory
3995region is marked as private to QEMU, or shared. The latter allows
3996a co-operating external process to access the QEMU memory region.
3997
3998The @option{share} is also required for pvrdma devices due to
3999limitations in the RDMA API provided by Linux.
4000
4001Setting share=on might affect the ability to configure NUMA
4002bindings for the memory backend under some circumstances, see
4003Documentation/vm/numa_memory_policy.txt on the Linux kernel
4004source tree for additional details.
4005
4006Setting the @option{discard-data} boolean option to @var{on}
4007indicates that file contents can be destroyed when QEMU exits,
4008to avoid unnecessarily flushing data to the backing file.  Note
4009that @option{discard-data} is only an optimization, and QEMU
4010might not discard file contents if it aborts unexpectedly or is
4011terminated using SIGKILL.
4012
4013The @option{merge} boolean option enables memory merge, also known as
4014MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
4015memory deduplication.
4016
4017Setting the @option{dump} boolean option to @var{off} excludes the memory from
4018core dumps. This feature is also known as MADV_DONTDUMP.
4019
4020The @option{prealloc} boolean option enables memory preallocation.
4021
4022The @option{host-nodes} option binds the memory range to a list of NUMA host
4023nodes.
4024
4025The @option{policy} option sets the NUMA policy to one of the following values:
4026
4027@table @option
4028@item @var{default}
4029default host policy
4030
4031@item @var{preferred}
4032prefer the given host node list for allocation
4033
4034@item @var{bind}
4035restrict memory allocation to the given host node list
4036
4037@item @var{interleave}
4038interleave memory allocations across the given host node list
4039@end table
4040
4041The @option{align} option specifies the base address alignment when
4042QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
4043@option{2M}. Some backend store specified by @option{mem-path}
4044requires an alignment different than the default one used by QEMU, eg
4045the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4046such cases, users can specify the required alignment via this option.
4047
4048@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}
4049
4050Creates a memory backend object, which can be used to back the guest RAM.
4051Memory backend objects offer more control than the @option{-m} option that is
4052traditionally used to define guest RAM. Please refer to
4053@option{memory-backend-file} for a description of the options.
4054
4055@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}
4056
4057Creates an anonymous memory file backend object, which allows QEMU to
4058share the memory with an external process (e.g. when using
4059vhost-user). The memory is allocated with memfd and optional
4060sealing. (Linux only)
4061
4062The @option{seal} option creates a sealed-file, that will block
4063further resizing the memory ('on' by default).
4064
4065The @option{hugetlb} option specify the file to be created resides in
4066the hugetlbfs filesystem (since Linux 4.14).  Used in conjunction with
4067the @option{hugetlb} option, the @option{hugetlbsize} option specify
4068the hugetlb page size on systems that support multiple hugetlb page
4069sizes (it must be a power of 2 value supported by the system).
4070
4071In some versions of Linux, the @option{hugetlb} option is incompatible
4072with the @option{seal} option (requires at least Linux 4.16).
4073
4074Please refer to @option{memory-backend-file} for a description of the
4075other options.
4076
4077@item -object rng-random,id=@var{id},filename=@var{/dev/random}
4078
4079Creates a random number generator backend which obtains entropy from
4080a device on the host. The @option{id} parameter is a unique ID that
4081will be used to reference this entropy backend from the @option{virtio-rng}
4082device. The @option{filename} parameter specifies which file to obtain
4083entropy from and if omitted defaults to @option{/dev/random}.
4084
4085@item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4086
4087Creates a random number generator backend which obtains entropy from
4088an external daemon running on the host. The @option{id} parameter is
4089a unique ID that will be used to reference this entropy backend from
4090the @option{virtio-rng} device. The @option{chardev} parameter is
4091the unique ID of a character device backend that provides the connection
4092to the RNG daemon.
4093
4094@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4095
4096Creates a TLS anonymous credentials object, which can be used to provide
4097TLS support on network backends. The @option{id} parameter is a unique
4098ID which network backends will use to access the credentials. The
4099@option{endpoint} is either @option{server} or @option{client} depending
4100on whether the QEMU network backend that uses the credentials will be
4101acting as a client or as a server. If @option{verify-peer} is enabled
4102(the default) then once the handshake is completed, the peer credentials
4103will be verified, though this is a no-op for anonymous credentials.
4104
4105The @var{dir} parameter tells QEMU where to find the credential
4106files. For server endpoints, this directory may contain a file
4107@var{dh-params.pem} providing diffie-hellman parameters to use
4108for the TLS server. If the file is missing, QEMU will generate
4109a set of DH parameters at startup. This is a computationally
4110expensive operation that consumes random pool entropy, so it is
4111recommended that a persistent set of parameters be generated
4112upfront and saved.
4113
4114@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}
4115
4116Creates a TLS anonymous credentials object, which can be used to provide
4117TLS support on network backends. The @option{id} parameter is a unique
4118ID which network backends will use to access the credentials. The
4119@option{endpoint} is either @option{server} or @option{client} depending
4120on whether the QEMU network backend that uses the credentials will be
4121acting as a client or as a server. If @option{verify-peer} is enabled
4122(the default) then once the handshake is completed, the peer credentials
4123will be verified. With x509 certificates, this implies that the clients
4124must be provided with valid client certificates too.
4125
4126The @var{dir} parameter tells QEMU where to find the credential
4127files. For server endpoints, this directory may contain a file
4128@var{dh-params.pem} providing diffie-hellman parameters to use
4129for the TLS server. If the file is missing, QEMU will generate
4130a set of DH parameters at startup. This is a computationally
4131expensive operation that consumes random pool entropy, so it is
4132recommended that a persistent set of parameters be generated
4133upfront and saved.
4134
4135For x509 certificate credentials the directory will contain further files
4136providing the x509 certificates. The certificates must be stored
4137in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4138@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4139@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4140
4141For the @var{server-key.pem} and @var{client-key.pem} files which
4142contain sensitive private keys, it is possible to use an encrypted
4143version by providing the @var{passwordid} parameter. This provides
4144the ID of a previously created @code{secret} object containing the
4145password for decryption.
4146
4147The @var{priority} parameter allows to override the global default
4148priority used by gnutls. This can be useful if the system administrator
4149needs to use a weaker set of crypto priorities for QEMU without
4150potentially forcing the weakness onto all applications. Or conversely
4151if one wants wants a stronger default for QEMU than for all other
4152applications, they can do this through this parameter. Its format is
4153a gnutls priority string as described at
4154@url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4155
4156@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4157
4158Interval @var{t} can't be 0, this filter batches the packet delivery: all
4159packets arriving in a given interval on netdev @var{netdevid} are delayed
4160until the end of the interval. Interval is in microseconds.
4161@option{status} is optional that indicate whether the netfilter is
4162on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4163
4164queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4165
4166@option{all}: the filter is attached both to the receive and the transmit
4167              queue of the netdev (default).
4168
4169@option{rx}: the filter is attached to the receive queue of the netdev,
4170             where it will receive packets sent to the netdev.
4171
4172@option{tx}: the filter is attached to the transmit queue of the netdev,
4173             where it will receive packets sent by the netdev.
4174
4175@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4176
4177filter-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.
4178
4179@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4180
4181filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4182@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4183filter-redirector will redirect packet with vnet_hdr_len.
4184Create a filter-redirector we need to differ outdev id from indev id, id can not
4185be the same. we can just use indev or outdev, but at least one of indev or outdev
4186need to be specified.
4187
4188@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4189
4190Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4191secondary from primary to keep secondary tcp connection,and rewrite
4192tcp packet to primary from secondary make tcp packet can be handled by
4193client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4194
4195usage:
4196colo secondary:
4197-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4198-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4199-object filter-rewriter,id=rew0,netdev=hn0,queue=all
4200
4201@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4202
4203Dump the network traffic on netdev @var{dev} to the file specified by
4204@var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4205The file format is libpcap, so it can be analyzed with tools such as tcpdump
4206or Wireshark.
4207
4208@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4209
4210Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4211secondary packet. If the packets are same, we will output primary
4212packet to outdev@var{chardevid}, else we will notify colo-frame
4213do checkpoint and send primary packet to outdev@var{chardevid}.
4214if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4215
4216we must use it with the help of filter-mirror and filter-redirector.
4217
4218@example
4219
4220primary:
4221-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4222-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4223-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4224-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4225-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4226-chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4227-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4228-chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4229-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4230-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4231-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4232-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4233
4234secondary:
4235-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4236-device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4237-chardev socket,id=red0,host=3.3.3.3,port=9003
4238-chardev socket,id=red1,host=3.3.3.3,port=9004
4239-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4240-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4241
4242@end example
4243
4244If you want to know the detail of above command line, you can read
4245the colo-compare git log.
4246
4247@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4248
4249Creates a cryptodev backend which executes crypto opreation from
4250the QEMU cipher APIS. The @var{id} parameter is
4251a unique ID that will be used to reference this cryptodev backend from
4252the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4253which specify the queue number of cryptodev backend, the default of
4254@var{queues} is 1.
4255
4256@example
4257
4258 # qemu-system-x86_64 \
4259   [...] \
4260       -object cryptodev-backend-builtin,id=cryptodev0 \
4261       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4262   [...]
4263@end example
4264
4265@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4266
4267Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4268The @var{id} parameter is a unique ID that will be used to reference this
4269cryptodev backend from the @option{virtio-crypto} device.
4270The chardev should be a unix domain socket backed one. The vhost-user uses
4271a specifically defined protocol to pass vhost ioctl replacement messages
4272to an application on the other end of the socket.
4273The @var{queues} parameter is optional, which specify the queue number
4274of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4275
4276@example
4277
4278 # qemu-system-x86_64 \
4279   [...] \
4280       -chardev socket,id=chardev0,path=/path/to/socket \
4281       -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4282       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4283   [...]
4284@end example
4285
4286@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4287@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4288
4289Defines a secret to store a password, encryption key, or some other sensitive
4290data. The sensitive data can either be passed directly via the @var{data}
4291parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4292parameter is insecure unless the sensitive data is encrypted.
4293
4294The sensitive data can be provided in raw format (the default), or base64.
4295When encoded as JSON, the raw format only supports valid UTF-8 characters,
4296so base64 is recommended for sending binary data. QEMU will convert from
4297which ever format is provided to the format it needs internally. eg, an
4298RBD password can be provided in raw format, even though it will be base64
4299encoded when passed onto the RBD sever.
4300
4301For added protection, it is possible to encrypt the data associated with
4302a secret using the AES-256-CBC cipher. Use of encryption is indicated
4303by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4304parameter provides the ID of a previously defined secret that contains
4305the AES-256 decryption key. This key should be 32-bytes long and be
4306base64 encoded. The @var{iv} parameter provides the random initialization
4307vector used for encryption of this particular secret and should be a
4308base64 encrypted string of the 16-byte IV.
4309
4310The simplest (insecure) usage is to provide the secret inline
4311
4312@example
4313
4314 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4315
4316@end example
4317
4318The simplest secure usage is to provide the secret via a file
4319
4320 # printf "letmein" > mypasswd.txt
4321 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4322
4323For greater security, AES-256-CBC should be used. To illustrate usage,
4324consider the openssl command line tool which can encrypt the data. Note
4325that when encrypting, the plaintext must be padded to the cipher block
4326size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4327
4328First a master key needs to be created in base64 encoding:
4329
4330@example
4331 # openssl rand -base64 32 > key.b64
4332 # KEY=$(base64 -d key.b64 | hexdump  -v -e '/1 "%02X"')
4333@end example
4334
4335Each secret to be encrypted needs to have a random initialization vector
4336generated. These do not need to be kept secret
4337
4338@example
4339 # openssl rand -base64 16 > iv.b64
4340 # IV=$(base64 -d iv.b64 | hexdump  -v -e '/1 "%02X"')
4341@end example
4342
4343The secret to be defined can now be encrypted, in this case we're
4344telling openssl to base64 encode the result, but it could be left
4345as raw bytes if desired.
4346
4347@example
4348 # SECRET=$(printf "letmein" |
4349            openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4350@end example
4351
4352When launching QEMU, create a master secret pointing to @code{key.b64}
4353and specify that to be used to decrypt the user password. Pass the
4354contents of @code{iv.b64} to the second secret
4355
4356@example
4357 # $QEMU \
4358     -object secret,id=secmaster0,format=base64,file=key.b64 \
4359     -object secret,id=sec0,keyid=secmaster0,format=base64,\
4360         data=$SECRET,iv=$(<iv.b64)
4361@end example
4362
4363@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}]
4364
4365Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4366to provide the guest memory encryption support on AMD processors.
4367
4368When memory encryption is enabled, one of the physical address bit (aka the
4369C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4370is used to provide the C-bit position. The C-bit position is Host family dependent
4371hence user must provide this value. On EPYC, the value should be 47.
4372
4373When memory encryption is enabled, we loose certain bits in physical address space.
4374The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4375physical address space. Similar to C-bit, the value is Host family dependent.
4376On EPYC, the value should be 5.
4377
4378The @option{sev-device} provides the device file to use for communicating with
4379the SEV firmware running inside AMD Secure Processor. The default device is
4380'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are
4381created by CCP driver.
4382
4383The @option{policy} provides the guest policy to be enforced by the SEV firmware
4384and restrict what configuration and operational commands can be performed on this
4385guest by the hypervisor. The policy should be provided by the guest owner and is
4386bound to the guest and cannot be changed throughout the lifetime of the guest.
4387The default is 0.
4388
4389If guest @option{policy} allows sharing the key with another SEV guest then
4390@option{handle} can be use to provide handle of the guest from which to share
4391the key.
4392
4393The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4394Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters
4395are used for establishing a cryptographic session with the guest owner to
4396negotiate keys used for attestation. The file must be encoded in base64.
4397
4398e.g to launch a SEV guest
4399@example
4400 # $QEMU \
4401     ......
4402     -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \
4403     -machine ...,memory-encryption=sev0
4404     .....
4405
4406@end example
4407@end table
4408
4409ETEXI
4410
4411
4412HXCOMM This is the last statement. Insert new options before this line!
4413STEXI
4414@end table
4415ETEXI
4416