xref: /qemu/qemu-options.hx (revision 5b262bb6)
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, tcg (default: tcg)\n"
35    "                kernel_irqchip=on|off controls accelerated irqchip support\n"
36    "                kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n"
37    "                vmport=on|off|auto controls emulation of vmport (default: auto)\n"
38    "                kvm_shadow_mem=size of KVM shadow MMU in bytes\n"
39    "                dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
40    "                mem-merge=on|off controls memory merge support (default: on)\n"
41    "                igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
42    "                aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
43    "                dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
44    "                suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
45    "                nvdimm=on|off controls NVDIMM support (default=off)\n"
46    "                enforce-config-section=on|off enforce configuration section migration (default=off)\n",
47    QEMU_ARCH_ALL)
48STEXI
49@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
50@findex -machine
51Select the emulated machine by @var{name}. Use @code{-machine help} to list
52available machines. Supported machine properties are:
53@table @option
54@item accel=@var{accels1}[:@var{accels2}[:...]]
55This is used to enable an accelerator. Depending on the target architecture,
56kvm, xen, or tcg can be available. By default, tcg is used. If there is more
57than one accelerator specified, the next one is used if the previous one fails
58to initialize.
59@item kernel_irqchip=on|off
60Controls in-kernel irqchip support for the chosen accelerator when available.
61@item gfx_passthru=on|off
62Enables IGD GFX passthrough support for the chosen machine when available.
63@item vmport=on|off|auto
64Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
65value based on accel. For accel=xen the default is off otherwise the default
66is on.
67@item kvm_shadow_mem=size
68Defines the size of the KVM shadow MMU.
69@item dump-guest-core=on|off
70Include guest memory in a core dump. The default is on.
71@item mem-merge=on|off
72Enables or disables memory merge support. This feature, when supported by
73the host, de-duplicates identical memory pages among VMs instances
74(enabled by default).
75@item aes-key-wrap=on|off
76Enables or disables AES key wrapping support on s390-ccw hosts. This feature
77controls whether AES wrapping keys will be created to allow
78execution of AES cryptographic functions.  The default is on.
79@item dea-key-wrap=on|off
80Enables or disables DEA key wrapping support on s390-ccw hosts. This feature
81controls whether DEA wrapping keys will be created to allow
82execution of DEA cryptographic functions.  The default is on.
83@item nvdimm=on|off
84Enables or disables NVDIMM support. The default is off.
85@end table
86ETEXI
87
88HXCOMM Deprecated by -machine
89DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
90
91DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
92    "-cpu cpu        select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
93STEXI
94@item -cpu @var{model}
95@findex -cpu
96Select CPU model (@code{-cpu help} for list and additional feature selection)
97ETEXI
98
99DEF("smp", HAS_ARG, QEMU_OPTION_smp,
100    "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
101    "                set the number of CPUs to 'n' [default=1]\n"
102    "                maxcpus= maximum number of total cpus, including\n"
103    "                offline CPUs for hotplug, etc\n"
104    "                cores= number of CPU cores on one socket\n"
105    "                threads= number of threads on one CPU core\n"
106    "                sockets= number of discrete sockets in the system\n",
107        QEMU_ARCH_ALL)
108STEXI
109@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
110@findex -smp
111Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
112CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
113to 4.
114For the PC target, the number of @var{cores} per socket, the number
115of @var{threads} per cores and the total number of @var{sockets} can be
116specified. Missing values will be computed. If any on the three values is
117given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
118specifies the maximum number of hotpluggable CPUs.
119ETEXI
120
121DEF("numa", HAS_ARG, QEMU_OPTION_numa,
122    "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n"
123    "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL)
124STEXI
125@item -numa node[,mem=@var{size}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}]
126@itemx -numa node[,memdev=@var{id}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}]
127@findex -numa
128Simulate a multi node NUMA system. If @samp{mem}, @samp{memdev}
129and @samp{cpus} are omitted, resources are split equally. Also, note
130that the -@option{numa} option doesn't allocate any of the specified
131resources. That is, it just assigns existing resources to NUMA nodes. This
132means that one still has to use the @option{-m}, @option{-smp} options
133to allocate RAM and VCPUs respectively, and possibly @option{-object}
134to specify the memory backend for the @samp{memdev} suboption.
135
136@samp{mem} and @samp{memdev} are mutually exclusive.  Furthermore, if one
137node uses @samp{memdev}, all of them have to use it.
138ETEXI
139
140DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
141    "-add-fd fd=fd,set=set[,opaque=opaque]\n"
142    "                Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
143STEXI
144@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
145@findex -add-fd
146
147Add a file descriptor to an fd set.  Valid options are:
148
149@table @option
150@item fd=@var{fd}
151This option defines the file descriptor of which a duplicate is added to fd set.
152The file descriptor cannot be stdin, stdout, or stderr.
153@item set=@var{set}
154This option defines the ID of the fd set to add the file descriptor to.
155@item opaque=@var{opaque}
156This option defines a free-form string that can be used to describe @var{fd}.
157@end table
158
159You can open an image using pre-opened file descriptors from an fd set:
160@example
161qemu-system-i386
162-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
163-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
164-drive file=/dev/fdset/2,index=0,media=disk
165@end example
166ETEXI
167
168DEF("set", HAS_ARG, QEMU_OPTION_set,
169    "-set group.id.arg=value\n"
170    "                set <arg> parameter for item <id> of type <group>\n"
171    "                i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
172STEXI
173@item -set @var{group}.@var{id}.@var{arg}=@var{value}
174@findex -set
175Set parameter @var{arg} for item @var{id} of type @var{group}\n"
176ETEXI
177
178DEF("global", HAS_ARG, QEMU_OPTION_global,
179    "-global driver.property=value\n"
180    "-global driver=driver,property=property,value=value\n"
181    "                set a global default for a driver property\n",
182    QEMU_ARCH_ALL)
183STEXI
184@item -global @var{driver}.@var{prop}=@var{value}
185@itemx -global driver=@var{driver},property=@var{property},value=@var{value}
186@findex -global
187Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
188
189@example
190qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk
191@end example
192
193In particular, you can use this to set driver properties for devices which are
194created automatically by the machine model. To create a device which is not
195created automatically and set properties on it, use -@option{device}.
196
197-global @var{driver}.@var{prop}=@var{value} is shorthand for -global
198driver=@var{driver},property=@var{prop},value=@var{value}.  The
199longhand syntax works even when @var{driver} contains a dot.
200ETEXI
201
202DEF("boot", HAS_ARG, QEMU_OPTION_boot,
203    "-boot [order=drives][,once=drives][,menu=on|off]\n"
204    "      [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
205    "                'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
206    "                'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
207    "                'sp_time': the period that splash picture last if menu=on, unit is ms\n"
208    "                'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
209    QEMU_ARCH_ALL)
210STEXI
211@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]
212@findex -boot
213Specify boot order @var{drives} as a string of drive letters. Valid
214drive letters depend on the target architecture. The x86 PC uses: a, b
215(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
216from network adapter 1-4), hard disk boot is the default. To apply a
217particular boot order only on the first startup, specify it via
218@option{once}.
219
220Interactive boot menus/prompts can be enabled via @option{menu=on} as far
221as firmware/BIOS supports them. The default is non-interactive boot.
222
223A splash picture could be passed to bios, enabling user to show it as logo,
224when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
225supports them. Currently Seabios for X86 system support it.
226limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
227format(true color). The resolution should be supported by the SVGA mode, so
228the recommended is 320x240, 640x480, 800x640.
229
230A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
231when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
232reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
233system support it.
234
235Do strict boot via @option{strict=on} as far as firmware/BIOS
236supports it. This only effects when boot priority is changed by
237bootindex options. The default is non-strict boot.
238
239@example
240# try to boot from network first, then from hard disk
241qemu-system-i386 -boot order=nc
242# boot from CD-ROM first, switch back to default order after reboot
243qemu-system-i386 -boot once=d
244# boot with a splash picture for 5 seconds.
245qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
246@end example
247
248Note: The legacy format '-boot @var{drives}' is still supported but its
249use is discouraged as it may be removed from future versions.
250ETEXI
251
252DEF("m", HAS_ARG, QEMU_OPTION_m,
253    "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
254    "                configure guest RAM\n"
255    "                size: initial amount of guest memory\n"
256    "                slots: number of hotplug slots (default: none)\n"
257    "                maxmem: maximum amount of guest memory (default: none)\n"
258    "NOTE: Some architectures might enforce a specific granularity\n",
259    QEMU_ARCH_ALL)
260STEXI
261@item -m [size=]@var{megs}[,slots=n,maxmem=size]
262@findex -m
263Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
264Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
265megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
266could be used to set amount of hotpluggable memory slots and maximum amount of
267memory. Note that @var{maxmem} must be aligned to the page size.
268
269For example, the following command-line sets the guest startup RAM size to
2701GB, creates 3 slots to hotplug additional memory and sets the maximum
271memory the guest can reach to 4GB:
272
273@example
274qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
275@end example
276
277If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
278be enabled and the guest startup RAM will never increase.
279ETEXI
280
281DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
282    "-mem-path FILE  provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
283STEXI
284@item -mem-path @var{path}
285@findex -mem-path
286Allocate guest RAM from a temporarily created file in @var{path}.
287ETEXI
288
289DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
290    "-mem-prealloc   preallocate guest memory (use with -mem-path)\n",
291    QEMU_ARCH_ALL)
292STEXI
293@item -mem-prealloc
294@findex -mem-prealloc
295Preallocate memory when using -mem-path.
296ETEXI
297
298DEF("k", HAS_ARG, QEMU_OPTION_k,
299    "-k language     use keyboard layout (for example 'fr' for French)\n",
300    QEMU_ARCH_ALL)
301STEXI
302@item -k @var{language}
303@findex -k
304Use keyboard layout @var{language} (for example @code{fr} for
305French). This option is only needed where it is not easy to get raw PC
306keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
307display). You don't normally need to use it on PC/Linux or PC/Windows
308hosts.
309
310The available layouts are:
311@example
312ar  de-ch  es  fo     fr-ca  hu  ja  mk     no  pt-br  sv
313da  en-gb  et  fr     fr-ch  is  lt  nl     pl  ru     th
314de  en-us  fi  fr-be  hr     it  lv  nl-be  pt  sl     tr
315@end example
316
317The default is @code{en-us}.
318ETEXI
319
320
321DEF("audio-help", 0, QEMU_OPTION_audio_help,
322    "-audio-help     print list of audio drivers and their options\n",
323    QEMU_ARCH_ALL)
324STEXI
325@item -audio-help
326@findex -audio-help
327Will show the audio subsystem help: list of drivers, tunable
328parameters.
329ETEXI
330
331DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
332    "-soundhw c1,... enable audio support\n"
333    "                and only specified sound cards (comma separated list)\n"
334    "                use '-soundhw help' to get the list of supported cards\n"
335    "                use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
336STEXI
337@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
338@findex -soundhw
339Enable audio and selected sound hardware. Use 'help' to print all
340available sound hardware.
341
342@example
343qemu-system-i386 -soundhw sb16,adlib disk.img
344qemu-system-i386 -soundhw es1370 disk.img
345qemu-system-i386 -soundhw ac97 disk.img
346qemu-system-i386 -soundhw hda disk.img
347qemu-system-i386 -soundhw all disk.img
348qemu-system-i386 -soundhw help
349@end example
350
351Note that Linux's i810_audio OSS kernel (for AC97) module might
352require manually specifying clocking.
353
354@example
355modprobe i810_audio clocking=48000
356@end example
357ETEXI
358
359DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
360    "-balloon none   disable balloon device\n"
361    "-balloon virtio[,addr=str]\n"
362    "                enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
363STEXI
364@item -balloon none
365@findex -balloon
366Disable balloon device.
367@item -balloon virtio[,addr=@var{addr}]
368Enable virtio balloon device (default), optionally with PCI address
369@var{addr}.
370ETEXI
371
372DEF("device", HAS_ARG, QEMU_OPTION_device,
373    "-device driver[,prop[=value][,...]]\n"
374    "                add device (based on driver)\n"
375    "                prop=value,... sets driver properties\n"
376    "                use '-device help' to print all possible drivers\n"
377    "                use '-device driver,help' to print all possible properties\n",
378    QEMU_ARCH_ALL)
379STEXI
380@item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
381@findex -device
382Add device @var{driver}.  @var{prop}=@var{value} sets driver
383properties.  Valid properties depend on the driver.  To get help on
384possible drivers and properties, use @code{-device help} and
385@code{-device @var{driver},help}.
386
387Some drivers are:
388@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}]
389
390Add an IPMI BMC.  This is a simulation of a hardware management
391interface processor that normally sits on a system.  It provides
392a watchdog and the ability to reset and power control the system.
393You need to connect this to an IPMI interface to make it useful
394
395The IPMI slave address to use for the BMC.  The default is 0x20.
396This address is the BMC's address on the I2C network of management
397controllers.  If you don't know what this means, it is safe to ignore
398it.
399
400@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
401
402Add a connection to an external IPMI BMC simulator.  Instead of
403locally emulating the BMC like the above item, instead connect
404to an external entity that provides the IPMI services.
405
406A connection is made to an external BMC simulator.  If you do this, it
407is strongly recommended that you use the "reconnect=" chardev option
408to reconnect to the simulator if the connection is lost.  Note that if
409this is not used carefully, it can be a security issue, as the
410interface has the ability to send resets, NMIs, and power off the VM.
411It's best if QEMU makes a connection to an external simulator running
412on a secure port on localhost, so neither the simulator nor QEMU is
413exposed to any outside network.
414
415See the "lanserv/README.vm" file in the OpenIPMI library for more
416details on the external interface.
417
418@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
419
420Add a KCS IPMI interafce on the ISA bus.  This also adds a
421corresponding ACPI and SMBIOS entries, if appropriate.
422
423@table @option
424@item bmc=@var{id}
425The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
426@item ioport=@var{val}
427Define the I/O address of the interface.  The default is 0xca0 for KCS.
428@item irq=@var{val}
429Define the interrupt to use.  The default is 5.  To disable interrupts,
430set this to 0.
431@end table
432
433@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
434
435Like the KCS interface, but defines a BT interface.  The default port is
4360xe4 and the default interrupt is 5.
437
438ETEXI
439
440DEF("name", HAS_ARG, QEMU_OPTION_name,
441    "-name string1[,process=string2][,debug-threads=on|off]\n"
442    "                set the name of the guest\n"
443    "                string1 sets the window title and string2 the process name (on Linux)\n"
444    "                When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
445    "                NOTE: The thread names are for debugging and not a stable API.\n",
446    QEMU_ARCH_ALL)
447STEXI
448@item -name @var{name}
449@findex -name
450Sets the @var{name} of the guest.
451This name will be displayed in the SDL window caption.
452The @var{name} will also be used for the VNC server.
453Also optionally set the top visible process name in Linux.
454Naming of individual threads can also be enabled on Linux to aid debugging.
455ETEXI
456
457DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
458    "-uuid %08x-%04x-%04x-%04x-%012x\n"
459    "                specify machine UUID\n", QEMU_ARCH_ALL)
460STEXI
461@item -uuid @var{uuid}
462@findex -uuid
463Set system UUID.
464ETEXI
465
466STEXI
467@end table
468ETEXI
469DEFHEADING()
470
471DEFHEADING(Block device options:)
472STEXI
473@table @option
474ETEXI
475
476DEF("fda", HAS_ARG, QEMU_OPTION_fda,
477    "-fda/-fdb file  use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
478DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
479STEXI
480@item -fda @var{file}
481@itemx -fdb @var{file}
482@findex -fda
483@findex -fdb
484Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
485ETEXI
486
487DEF("hda", HAS_ARG, QEMU_OPTION_hda,
488    "-hda/-hdb file  use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
489DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
490DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
491    "-hdc/-hdd file  use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
492DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
493STEXI
494@item -hda @var{file}
495@itemx -hdb @var{file}
496@itemx -hdc @var{file}
497@itemx -hdd @var{file}
498@findex -hda
499@findex -hdb
500@findex -hdc
501@findex -hdd
502Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
503ETEXI
504
505DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
506    "-cdrom file     use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
507    QEMU_ARCH_ALL)
508STEXI
509@item -cdrom @var{file}
510@findex -cdrom
511Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
512@option{-cdrom} at the same time). You can use the host CD-ROM by
513using @file{/dev/cdrom} as filename (@pxref{host_drives}).
514ETEXI
515
516DEF("drive", HAS_ARG, QEMU_OPTION_drive,
517    "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
518    "       [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
519    "       [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
520    "       [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
521    "       [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
522    "       [,readonly=on|off][,copy-on-read=on|off]\n"
523    "       [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
524    "       [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
525    "       [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
526    "       [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
527    "       [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
528    "       [[,iops_size=is]]\n"
529    "       [[,group=g]]\n"
530    "                use 'file' as a drive image\n", QEMU_ARCH_ALL)
531STEXI
532@item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
533@findex -drive
534
535Define a new drive. Valid options are:
536
537@table @option
538@item file=@var{file}
539This option defines which disk image (@pxref{disk_images}) to use with
540this drive. If the filename contains comma, you must double it
541(for instance, "file=my,,file" to use file "my,file").
542
543Special files such as iSCSI devices can be specified using protocol
544specific URLs. See the section for "Device URL Syntax" for more information.
545@item if=@var{interface}
546This option defines on which type on interface the drive is connected.
547Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio.
548@item bus=@var{bus},unit=@var{unit}
549These options define where is connected the drive by defining the bus number and
550the unit id.
551@item index=@var{index}
552This option defines where is connected the drive by using an index in the list
553of available connectors of a given interface type.
554@item media=@var{media}
555This option defines the type of the media: disk or cdrom.
556@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
557These options have the same definition as they have in @option{-hdachs}.
558@item snapshot=@var{snapshot}
559@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
560(see @option{-snapshot}).
561@item cache=@var{cache}
562@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
563@item aio=@var{aio}
564@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
565@item discard=@var{discard}
566@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap}) requests are ignored or passed to the filesystem.  Some machine types may not support discard requests.
567@item format=@var{format}
568Specify which disk @var{format} will be used rather than detecting
569the format.  Can be used to specify format=raw to avoid interpreting
570an untrusted format header.
571@item serial=@var{serial}
572This option specifies the serial number to assign to the device.
573@item addr=@var{addr}
574Specify the controller's PCI address (if=virtio only).
575@item werror=@var{action},rerror=@var{action}
576Specify which @var{action} to take on write and read errors. Valid actions are:
577"ignore" (ignore the error and try to continue), "stop" (pause QEMU),
578"report" (report the error to the guest), "enospc" (pause QEMU only if the
579host disk is full; report the error to the guest otherwise).
580The default setting is @option{werror=enospc} and @option{rerror=report}.
581@item readonly
582Open drive @option{file} as read-only. Guest write attempts will fail.
583@item copy-on-read=@var{copy-on-read}
584@var{copy-on-read} is "on" or "off" and enables whether to copy read backing
585file sectors into the image file.
586@item detect-zeroes=@var{detect-zeroes}
587@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
588conversion of plain zero writes by the OS to driver specific optimized
589zero write commands. You may even choose "unmap" if @var{discard} is set
590to "unmap" to allow a zero write to be converted to an UNMAP operation.
591@end table
592
593By default, the @option{cache=writeback} mode is used. It will report data
594writes as completed as soon as the data is present in the host page cache.
595This is safe as long as your guest OS makes sure to correctly flush disk caches
596where needed. If your guest OS does not handle volatile disk write caches
597correctly and your host crashes or loses power, then the guest may experience
598data corruption.
599
600For such guests, you should consider using @option{cache=writethrough}. This
601means that the host page cache will be used to read and write data, but write
602notification will be sent to the guest only after QEMU has made sure to flush
603each write to the disk. Be aware that this has a major impact on performance.
604
605The host page cache can be avoided entirely with @option{cache=none}.  This will
606attempt to do disk IO directly to the guest's memory.  QEMU may still perform
607an internal copy of the data. Note that this is considered a writeback mode and
608the guest OS must handle the disk write cache correctly in order to avoid data
609corruption on host crashes.
610
611The host page cache can be avoided while only sending write notifications to
612the guest when the data has been flushed to the disk using
613@option{cache=directsync}.
614
615In case you don't care about data integrity over host failures, use
616@option{cache=unsafe}. This option tells QEMU that it never needs to write any
617data to the disk but can instead keep things in cache. If anything goes wrong,
618like your host losing power, the disk storage getting disconnected accidentally,
619etc. your image will most probably be rendered unusable.   When using
620the @option{-snapshot} option, unsafe caching is always used.
621
622Copy-on-read avoids accessing the same backing file sectors repeatedly and is
623useful when the backing file is over a slow network.  By default copy-on-read
624is off.
625
626Instead of @option{-cdrom} you can use:
627@example
628qemu-system-i386 -drive file=file,index=2,media=cdrom
629@end example
630
631Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
632use:
633@example
634qemu-system-i386 -drive file=file,index=0,media=disk
635qemu-system-i386 -drive file=file,index=1,media=disk
636qemu-system-i386 -drive file=file,index=2,media=disk
637qemu-system-i386 -drive file=file,index=3,media=disk
638@end example
639
640You can open an image using pre-opened file descriptors from an fd set:
641@example
642qemu-system-i386
643-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
644-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
645-drive file=/dev/fdset/2,index=0,media=disk
646@end example
647
648You can connect a CDROM to the slave of ide0:
649@example
650qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
651@end example
652
653If you don't specify the "file=" argument, you define an empty drive:
654@example
655qemu-system-i386 -drive if=ide,index=1,media=cdrom
656@end example
657
658You can connect a SCSI disk with unit ID 6 on the bus #0:
659@example
660qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6
661@end example
662
663Instead of @option{-fda}, @option{-fdb}, you can use:
664@example
665qemu-system-i386 -drive file=file,index=0,if=floppy
666qemu-system-i386 -drive file=file,index=1,if=floppy
667@end example
668
669By default, @var{interface} is "ide" and @var{index} is automatically
670incremented:
671@example
672qemu-system-i386 -drive file=a -drive file=b"
673@end example
674is interpreted like:
675@example
676qemu-system-i386 -hda a -hdb b
677@end example
678ETEXI
679
680DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
681    "-mtdblock file  use 'file' as on-board Flash memory image\n",
682    QEMU_ARCH_ALL)
683STEXI
684@item -mtdblock @var{file}
685@findex -mtdblock
686Use @var{file} as on-board Flash memory image.
687ETEXI
688
689DEF("sd", HAS_ARG, QEMU_OPTION_sd,
690    "-sd file        use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
691STEXI
692@item -sd @var{file}
693@findex -sd
694Use @var{file} as SecureDigital card image.
695ETEXI
696
697DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
698    "-pflash file    use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
699STEXI
700@item -pflash @var{file}
701@findex -pflash
702Use @var{file} as a parallel flash image.
703ETEXI
704
705DEF("snapshot", 0, QEMU_OPTION_snapshot,
706    "-snapshot       write to temporary files instead of disk image files\n",
707    QEMU_ARCH_ALL)
708STEXI
709@item -snapshot
710@findex -snapshot
711Write to temporary files instead of disk image files. In this case,
712the raw disk image you use is not written back. You can however force
713the write back by pressing @key{C-a s} (@pxref{disk_images}).
714ETEXI
715
716DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
717    "-hdachs c,h,s[,t]\n" \
718    "                force hard disk 0 physical geometry and the optional BIOS\n" \
719    "                translation (t=none or lba) (usually QEMU can guess them)\n",
720    QEMU_ARCH_ALL)
721STEXI
722@item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
723@findex -hdachs
724Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
725@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
726translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
727all those parameters. This option is useful for old MS-DOS disk
728images.
729ETEXI
730
731DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
732    "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
733    " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
734    QEMU_ARCH_ALL)
735
736STEXI
737
738@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}]
739@findex -fsdev
740Define a new file system device. Valid options are:
741@table @option
742@item @var{fsdriver}
743This option specifies the fs driver backend to use.
744Currently "local", "handle" and "proxy" file system drivers are supported.
745@item id=@var{id}
746Specifies identifier for this device
747@item path=@var{path}
748Specifies the export path for the file system device. Files under
749this path will be available to the 9p client on the guest.
750@item security_model=@var{security_model}
751Specifies the security model to be used for this export path.
752Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
753In "passthrough" security model, files are stored using the same
754credentials as they are created on the guest. This requires QEMU
755to run as root. In "mapped-xattr" security model, some of the file
756attributes like uid, gid, mode bits and link target are stored as
757file attributes. For "mapped-file" these attributes are stored in the
758hidden .virtfs_metadata directory. Directories exported by this security model cannot
759interact with other unix tools. "none" security model is same as
760passthrough except the sever won't report failures if it fails to
761set file attributes like ownership. Security model is mandatory
762only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
763security model as a parameter.
764@item writeout=@var{writeout}
765This is an optional argument. The only supported value is "immediate".
766This means that host page cache will be used to read and write data but
767write notification will be sent to the guest only when the data has been
768reported as written by the storage subsystem.
769@item readonly
770Enables exporting 9p share as a readonly mount for guests. By default
771read-write access is given.
772@item socket=@var{socket}
773Enables proxy filesystem driver to use passed socket file for communicating
774with virtfs-proxy-helper
775@item sock_fd=@var{sock_fd}
776Enables proxy filesystem driver to use passed socket descriptor for
777communicating with virtfs-proxy-helper. Usually a helper like libvirt
778will create socketpair and pass one of the fds as sock_fd
779@end table
780
781-fsdev option is used along with -device driver "virtio-9p-pci".
782@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
783Options for virtio-9p-pci driver are:
784@table @option
785@item fsdev=@var{id}
786Specifies the id value specified along with -fsdev option
787@item mount_tag=@var{mount_tag}
788Specifies the tag name to be used by the guest to mount this export point
789@end table
790
791ETEXI
792
793DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
794    "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
795    "        [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
796    QEMU_ARCH_ALL)
797
798STEXI
799
800@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}]
801@findex -virtfs
802
803The general form of a Virtual File system pass-through options are:
804@table @option
805@item @var{fsdriver}
806This option specifies the fs driver backend to use.
807Currently "local", "handle" and "proxy" file system drivers are supported.
808@item id=@var{id}
809Specifies identifier for this device
810@item path=@var{path}
811Specifies the export path for the file system device. Files under
812this path will be available to the 9p client on the guest.
813@item security_model=@var{security_model}
814Specifies the security model to be used for this export path.
815Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
816In "passthrough" security model, files are stored using the same
817credentials as they are created on the guest. This requires QEMU
818to run as root. In "mapped-xattr" security model, some of the file
819attributes like uid, gid, mode bits and link target are stored as
820file attributes. For "mapped-file" these attributes are stored in the
821hidden .virtfs_metadata directory. Directories exported by this security model cannot
822interact with other unix tools. "none" security model is same as
823passthrough except the sever won't report failures if it fails to
824set file attributes like ownership. Security model is mandatory only
825for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
826model as a parameter.
827@item writeout=@var{writeout}
828This is an optional argument. The only supported value is "immediate".
829This means that host page cache will be used to read and write data but
830write notification will be sent to the guest only when the data has been
831reported as written by the storage subsystem.
832@item readonly
833Enables exporting 9p share as a readonly mount for guests. By default
834read-write access is given.
835@item socket=@var{socket}
836Enables proxy filesystem driver to use passed socket file for
837communicating with virtfs-proxy-helper. Usually a helper like libvirt
838will create socketpair and pass one of the fds as sock_fd
839@item sock_fd
840Enables proxy filesystem driver to use passed 'sock_fd' as the socket
841descriptor for interfacing with virtfs-proxy-helper
842@end table
843ETEXI
844
845DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
846    "-virtfs_synth Create synthetic file system image\n",
847    QEMU_ARCH_ALL)
848STEXI
849@item -virtfs_synth
850@findex -virtfs_synth
851Create synthetic file system image
852ETEXI
853
854STEXI
855@end table
856ETEXI
857DEFHEADING()
858
859DEFHEADING(USB options:)
860STEXI
861@table @option
862ETEXI
863
864DEF("usb", 0, QEMU_OPTION_usb,
865    "-usb            enable the USB driver (will be the default soon)\n",
866    QEMU_ARCH_ALL)
867STEXI
868@item -usb
869@findex -usb
870Enable the USB driver (will be the default soon)
871ETEXI
872
873DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
874    "-usbdevice name add the host or guest USB device 'name'\n",
875    QEMU_ARCH_ALL)
876STEXI
877
878@item -usbdevice @var{devname}
879@findex -usbdevice
880Add the USB device @var{devname}. @xref{usb_devices}.
881
882@table @option
883
884@item mouse
885Virtual Mouse. This will override the PS/2 mouse emulation when activated.
886
887@item tablet
888Pointer device that uses absolute coordinates (like a touchscreen). This
889means QEMU is able to report the mouse position without having to grab the
890mouse. Also overrides the PS/2 mouse emulation when activated.
891
892@item disk:[format=@var{format}]:@var{file}
893Mass storage device based on file. The optional @var{format} argument
894will be used rather than detecting the format. Can be used to specify
895@code{format=raw} to avoid interpreting an untrusted format header.
896
897@item host:@var{bus}.@var{addr}
898Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
899
900@item host:@var{vendor_id}:@var{product_id}
901Pass through the host device identified by @var{vendor_id}:@var{product_id}
902(Linux only).
903
904@item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
905Serial converter to host character device @var{dev}, see @code{-serial} for the
906available devices.
907
908@item braille
909Braille device.  This will use BrlAPI to display the braille output on a real
910or fake device.
911
912@item net:@var{options}
913Network adapter that supports CDC ethernet and RNDIS protocols.
914
915@end table
916ETEXI
917
918STEXI
919@end table
920ETEXI
921DEFHEADING()
922
923DEFHEADING(Display options:)
924STEXI
925@table @option
926ETEXI
927
928DEF("display", HAS_ARG, QEMU_OPTION_display,
929    "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
930    "            [,window_close=on|off][,gl=on|off]|curses|none|\n"
931    "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
932    "-display vnc=<display>[,<optargs>]\n"
933    "-display curses\n"
934    "-display none"
935    "                select display type\n"
936    "The default display is equivalent to\n"
937#if defined(CONFIG_GTK)
938            "\t\"-display gtk\"\n"
939#elif defined(CONFIG_SDL)
940            "\t\"-display sdl\"\n"
941#elif defined(CONFIG_COCOA)
942            "\t\"-display cocoa\"\n"
943#elif defined(CONFIG_VNC)
944            "\t\"-vnc localhost:0,to=99,id=default\"\n"
945#else
946            "\t\"-display none\"\n"
947#endif
948    , QEMU_ARCH_ALL)
949STEXI
950@item -display @var{type}
951@findex -display
952Select type of display to use. This option is a replacement for the
953old style -sdl/-curses/... options. Valid values for @var{type} are
954@table @option
955@item sdl
956Display video output via SDL (usually in a separate graphics
957window; see the SDL documentation for other possibilities).
958@item curses
959Display video output via curses. For graphics device models which
960support a text mode, QEMU can display this output using a
961curses/ncurses interface. Nothing is displayed when the graphics
962device is in graphical mode or if the graphics device does not support
963a text mode. Generally only the VGA device models support text mode.
964@item none
965Do not display video output. The guest will still see an emulated
966graphics card, but its output will not be displayed to the QEMU
967user. This option differs from the -nographic option in that it
968only affects what is done with video output; -nographic also changes
969the destination of the serial and parallel port data.
970@item gtk
971Display video output in a GTK window. This interface provides drop-down
972menus and other UI elements to configure and control the VM during
973runtime.
974@item vnc
975Start a VNC server on display <arg>
976@end table
977ETEXI
978
979DEF("nographic", 0, QEMU_OPTION_nographic,
980    "-nographic      disable graphical output and redirect serial I/Os to console\n",
981    QEMU_ARCH_ALL)
982STEXI
983@item -nographic
984@findex -nographic
985Normally, if QEMU is compiled with graphical window support, it displays
986output such as guest graphics, guest console, and the QEMU monitor in a
987window. With this option, you can totally disable graphical output so
988that QEMU is a simple command line application. The emulated serial port
989is redirected on the console and muxed with the monitor (unless
990redirected elsewhere explicitly). Therefore, you can still use QEMU to
991debug a Linux kernel with a serial console. Use @key{C-a h} for help on
992switching between the console and monitor.
993ETEXI
994
995DEF("curses", 0, QEMU_OPTION_curses,
996    "-curses         shorthand for -display curses\n",
997    QEMU_ARCH_ALL)
998STEXI
999@item -curses
1000@findex -curses
1001Normally, if QEMU is compiled with graphical window support, it displays
1002output such as guest graphics, guest console, and the QEMU monitor in a
1003window. With this option, QEMU can display the VGA output when in text
1004mode using a curses/ncurses interface. Nothing is displayed in graphical
1005mode.
1006ETEXI
1007
1008DEF("no-frame", 0, QEMU_OPTION_no_frame,
1009    "-no-frame       open SDL window without a frame and window decorations\n",
1010    QEMU_ARCH_ALL)
1011STEXI
1012@item -no-frame
1013@findex -no-frame
1014Do not use decorations for SDL windows and start them using the whole
1015available screen space. This makes the using QEMU in a dedicated desktop
1016workspace more convenient.
1017ETEXI
1018
1019DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1020    "-alt-grab       use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1021    QEMU_ARCH_ALL)
1022STEXI
1023@item -alt-grab
1024@findex -alt-grab
1025Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1026affects the special keys (for fullscreen, monitor-mode switching, etc).
1027ETEXI
1028
1029DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1030    "-ctrl-grab      use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1031    QEMU_ARCH_ALL)
1032STEXI
1033@item -ctrl-grab
1034@findex -ctrl-grab
1035Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1036affects the special keys (for fullscreen, monitor-mode switching, etc).
1037ETEXI
1038
1039DEF("no-quit", 0, QEMU_OPTION_no_quit,
1040    "-no-quit        disable SDL window close capability\n", QEMU_ARCH_ALL)
1041STEXI
1042@item -no-quit
1043@findex -no-quit
1044Disable SDL window close capability.
1045ETEXI
1046
1047DEF("sdl", 0, QEMU_OPTION_sdl,
1048    "-sdl            shorthand for -display sdl\n", QEMU_ARCH_ALL)
1049STEXI
1050@item -sdl
1051@findex -sdl
1052Enable SDL.
1053ETEXI
1054
1055DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1056    "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1057    "       [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1058    "       [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1059    "       [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1060    "       [,tls-ciphers=<list>]\n"
1061    "       [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1062    "       [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1063    "       [,sasl][,password=<secret>][,disable-ticketing]\n"
1064    "       [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1065    "       [,jpeg-wan-compression=[auto|never|always]]\n"
1066    "       [,zlib-glz-wan-compression=[auto|never|always]]\n"
1067    "       [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1068    "       [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1069    "       [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1070    "       [,gl=[on|off]]\n"
1071    "   enable spice\n"
1072    "   at least one of {port, tls-port} is mandatory\n",
1073    QEMU_ARCH_ALL)
1074STEXI
1075@item -spice @var{option}[,@var{option}[,...]]
1076@findex -spice
1077Enable the spice remote desktop protocol. Valid options are
1078
1079@table @option
1080
1081@item port=<nr>
1082Set the TCP port spice is listening on for plaintext channels.
1083
1084@item addr=<addr>
1085Set the IP address spice is listening on.  Default is any address.
1086
1087@item ipv4
1088@itemx ipv6
1089@itemx unix
1090Force using the specified IP version.
1091
1092@item password=<secret>
1093Set the password you need to authenticate.
1094
1095@item sasl
1096Require that the client use SASL to authenticate with the spice.
1097The exact choice of authentication method used is controlled from the
1098system / user's SASL configuration file for the 'qemu' service. This
1099is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1100unprivileged user, an environment variable SASL_CONF_PATH can be used
1101to make it search alternate locations for the service config.
1102While some SASL auth methods can also provide data encryption (eg GSSAPI),
1103it is recommended that SASL always be combined with the 'tls' and
1104'x509' settings to enable use of SSL and server certificates. This
1105ensures a data encryption preventing compromise of authentication
1106credentials.
1107
1108@item disable-ticketing
1109Allow client connects without authentication.
1110
1111@item disable-copy-paste
1112Disable copy paste between the client and the guest.
1113
1114@item disable-agent-file-xfer
1115Disable spice-vdagent based file-xfer between the client and the guest.
1116
1117@item tls-port=<nr>
1118Set the TCP port spice is listening on for encrypted channels.
1119
1120@item x509-dir=<dir>
1121Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1122
1123@item x509-key-file=<file>
1124@itemx x509-key-password=<file>
1125@itemx x509-cert-file=<file>
1126@itemx x509-cacert-file=<file>
1127@itemx x509-dh-key-file=<file>
1128The x509 file names can also be configured individually.
1129
1130@item tls-ciphers=<list>
1131Specify which ciphers to use.
1132
1133@item tls-channel=[main|display|cursor|inputs|record|playback]
1134@itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1135Force specific channel to be used with or without TLS encryption.  The
1136options can be specified multiple times to configure multiple
1137channels.  The special name "default" can be used to set the default
1138mode.  For channels which are not explicitly forced into one mode the
1139spice client is allowed to pick tls/plaintext as he pleases.
1140
1141@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1142Configure image compression (lossless).
1143Default is auto_glz.
1144
1145@item jpeg-wan-compression=[auto|never|always]
1146@itemx zlib-glz-wan-compression=[auto|never|always]
1147Configure wan image compression (lossy for slow links).
1148Default is auto.
1149
1150@item streaming-video=[off|all|filter]
1151Configure video stream detection.  Default is off.
1152
1153@item agent-mouse=[on|off]
1154Enable/disable passing mouse events via vdagent.  Default is on.
1155
1156@item playback-compression=[on|off]
1157Enable/disable audio stream compression (using celt 0.5.1).  Default is on.
1158
1159@item seamless-migration=[on|off]
1160Enable/disable spice seamless migration. Default is off.
1161
1162@item gl=[on|off]
1163Enable/disable OpenGL context. Default is off.
1164
1165@end table
1166ETEXI
1167
1168DEF("portrait", 0, QEMU_OPTION_portrait,
1169    "-portrait       rotate graphical output 90 deg left (only PXA LCD)\n",
1170    QEMU_ARCH_ALL)
1171STEXI
1172@item -portrait
1173@findex -portrait
1174Rotate graphical output 90 deg left (only PXA LCD).
1175ETEXI
1176
1177DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1178    "-rotate <deg>   rotate graphical output some deg left (only PXA LCD)\n",
1179    QEMU_ARCH_ALL)
1180STEXI
1181@item -rotate @var{deg}
1182@findex -rotate
1183Rotate graphical output some deg left (only PXA LCD).
1184ETEXI
1185
1186DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1187    "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1188    "                select video card type\n", QEMU_ARCH_ALL)
1189STEXI
1190@item -vga @var{type}
1191@findex -vga
1192Select type of VGA card to emulate. Valid values for @var{type} are
1193@table @option
1194@item cirrus
1195Cirrus Logic GD5446 Video card. All Windows versions starting from
1196Windows 95 should recognize and use this graphic card. For optimal
1197performances, use 16 bit color depth in the guest and the host OS.
1198(This one is the default)
1199@item std
1200Standard VGA card with Bochs VBE extensions.  If your guest OS
1201supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1202to use high resolution modes (>= 1280x1024x16) then you should use
1203this option.
1204@item vmware
1205VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1206recent XFree86/XOrg server or Windows guest with a driver for this
1207card.
1208@item qxl
1209QXL paravirtual graphic card.  It is VGA compatible (including VESA
12102.0 VBE support).  Works best with qxl guest drivers installed though.
1211Recommended choice when using the spice protocol.
1212@item tcx
1213(sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1214sun4m machines and offers both 8-bit and 24-bit colour depths at a
1215fixed resolution of 1024x768.
1216@item cg3
1217(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1218for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1219resolutions aimed at people wishing to run older Solaris versions.
1220@item virtio
1221Virtio VGA card.
1222@item none
1223Disable VGA card.
1224@end table
1225ETEXI
1226
1227DEF("full-screen", 0, QEMU_OPTION_full_screen,
1228    "-full-screen    start in full screen\n", QEMU_ARCH_ALL)
1229STEXI
1230@item -full-screen
1231@findex -full-screen
1232Start in full screen.
1233ETEXI
1234
1235DEF("g", 1, QEMU_OPTION_g ,
1236    "-g WxH[xDEPTH]  Set the initial graphical resolution and depth\n",
1237    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1238STEXI
1239@item -g @var{width}x@var{height}[x@var{depth}]
1240@findex -g
1241Set the initial graphical resolution and depth (PPC, SPARC only).
1242ETEXI
1243
1244DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1245    "-vnc <display>  shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1246STEXI
1247@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1248@findex -vnc
1249Normally, if QEMU is compiled with graphical window support, it displays
1250output such as guest graphics, guest console, and the QEMU monitor in a
1251window. With this option, you can have QEMU listen on VNC display
1252@var{display} and redirect the VGA display over the VNC session. It is
1253very useful to enable the usb tablet device when using this option
1254(option @option{-usbdevice tablet}). When using the VNC display, you
1255must use the @option{-k} parameter to set the keyboard layout if you are
1256not using en-us. Valid syntax for the @var{display} is
1257
1258@table @option
1259
1260@item to=@var{L}
1261
1262With this option, QEMU will try next available VNC @var{display}s, until the
1263number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1264available, e.g. port 5900+@var{display} is already used by another
1265application. By default, to=0.
1266
1267@item @var{host}:@var{d}
1268
1269TCP connections will only be allowed from @var{host} on display @var{d}.
1270By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1271be omitted in which case the server will accept connections from any host.
1272
1273@item unix:@var{path}
1274
1275Connections will be allowed over UNIX domain sockets where @var{path} is the
1276location of a unix socket to listen for connections on.
1277
1278@item none
1279
1280VNC is initialized but not started. The monitor @code{change} command
1281can be used to later start the VNC server.
1282
1283@end table
1284
1285Following the @var{display} value there may be one or more @var{option} flags
1286separated by commas. Valid options are
1287
1288@table @option
1289
1290@item reverse
1291
1292Connect to a listening VNC client via a ``reverse'' connection. The
1293client is specified by the @var{display}. For reverse network
1294connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1295is a TCP port number, not a display number.
1296
1297@item websocket
1298
1299Opens an additional TCP listening port dedicated to VNC Websocket connections.
1300By definition the Websocket port is 5700+@var{display}. If @var{host} is
1301specified connections will only be allowed from this host.
1302As an alternative the Websocket port could be specified by using
1303@code{websocket}=@var{port}.
1304If no TLS credentials are provided, the websocket connection runs in
1305unencrypted mode. If TLS credentials are provided, the websocket connection
1306requires encrypted client connections.
1307
1308@item password
1309
1310Require that password based authentication is used for client connections.
1311
1312The password must be set separately using the @code{set_password} command in
1313the @ref{pcsys_monitor}. The syntax to change your password is:
1314@code{set_password <protocol> <password>} where <protocol> could be either
1315"vnc" or "spice".
1316
1317If you would like to change <protocol> password expiration, you should use
1318@code{expire_password <protocol> <expiration-time>} where expiration time could
1319be one of the following options: now, never, +seconds or UNIX time of
1320expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1321to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1322date and time).
1323
1324You can also use keywords "now" or "never" for the expiration time to
1325allow <protocol> password to expire immediately or never expire.
1326
1327@item tls-creds=@var{ID}
1328
1329Provides the ID of a set of TLS credentials to use to secure the
1330VNC server. They will apply to both the normal VNC server socket
1331and the websocket socket (if enabled). Setting TLS credentials
1332will cause the VNC server socket to enable the VeNCrypt auth
1333mechanism.  The credentials should have been previously created
1334using the @option{-object tls-creds} argument.
1335
1336The @option{tls-creds} parameter obsoletes the @option{tls},
1337@option{x509}, and @option{x509verify} options, and as such
1338it is not permitted to set both new and old type options at
1339the same time.
1340
1341@item tls
1342
1343Require that client use TLS when communicating with the VNC server. This
1344uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1345attack. It is recommended that this option be combined with either the
1346@option{x509} or @option{x509verify} options.
1347
1348This option is now deprecated in favor of using the @option{tls-creds}
1349argument.
1350
1351@item x509=@var{/path/to/certificate/dir}
1352
1353Valid if @option{tls} is specified. Require that x509 credentials are used
1354for negotiating the TLS session. The server will send its x509 certificate
1355to the client. It is recommended that a password be set on the VNC server
1356to provide authentication of the client when this is used. The path following
1357this option specifies where the x509 certificates are to be loaded from.
1358See the @ref{vnc_security} section for details on generating certificates.
1359
1360This option is now deprecated in favour of using the @option{tls-creds}
1361argument.
1362
1363@item x509verify=@var{/path/to/certificate/dir}
1364
1365Valid if @option{tls} is specified. Require that x509 credentials are used
1366for negotiating the TLS session. The server will send its x509 certificate
1367to the client, and request that the client send its own x509 certificate.
1368The server will validate the client's certificate against the CA certificate,
1369and reject clients when validation fails. If the certificate authority is
1370trusted, this is a sufficient authentication mechanism. You may still wish
1371to set a password on the VNC server as a second authentication layer. The
1372path following this option specifies where the x509 certificates are to
1373be loaded from. See the @ref{vnc_security} section for details on generating
1374certificates.
1375
1376This option is now deprecated in favour of using the @option{tls-creds}
1377argument.
1378
1379@item sasl
1380
1381Require that the client use SASL to authenticate with the VNC server.
1382The exact choice of authentication method used is controlled from the
1383system / user's SASL configuration file for the 'qemu' service. This
1384is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1385unprivileged user, an environment variable SASL_CONF_PATH can be used
1386to make it search alternate locations for the service config.
1387While some SASL auth methods can also provide data encryption (eg GSSAPI),
1388it is recommended that SASL always be combined with the 'tls' and
1389'x509' settings to enable use of SSL and server certificates. This
1390ensures a data encryption preventing compromise of authentication
1391credentials. See the @ref{vnc_security} section for details on using
1392SASL authentication.
1393
1394@item acl
1395
1396Turn on access control lists for checking of the x509 client certificate
1397and SASL party. For x509 certs, the ACL check is made against the
1398certificate's distinguished name. This is something that looks like
1399@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1400made against the username, which depending on the SASL plugin, may
1401include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1402When the @option{acl} flag is set, the initial access list will be
1403empty, with a @code{deny} policy. Thus no one will be allowed to
1404use the VNC server until the ACLs have been loaded. This can be
1405achieved using the @code{acl} monitor command.
1406
1407@item lossy
1408
1409Enable lossy compression methods (gradient, JPEG, ...). If this
1410option is set, VNC client may receive lossy framebuffer updates
1411depending on its encoding settings. Enabling this option can save
1412a lot of bandwidth at the expense of quality.
1413
1414@item non-adaptive
1415
1416Disable adaptive encodings. Adaptive encodings are enabled by default.
1417An adaptive encoding will try to detect frequently updated screen regions,
1418and send updates in these regions using a lossy encoding (like JPEG).
1419This can be really helpful to save bandwidth when playing videos. Disabling
1420adaptive encodings restores the original static behavior of encodings
1421like Tight.
1422
1423@item share=[allow-exclusive|force-shared|ignore]
1424
1425Set display sharing policy.  'allow-exclusive' allows clients to ask
1426for exclusive access.  As suggested by the rfb spec this is
1427implemented by dropping other connections.  Connecting multiple
1428clients in parallel requires all clients asking for a shared session
1429(vncviewer: -shared switch).  This is the default.  'force-shared'
1430disables exclusive client access.  Useful for shared desktop sessions,
1431where you don't want someone forgetting specify -shared disconnect
1432everybody else.  'ignore' completely ignores the shared flag and
1433allows everybody connect unconditionally.  Doesn't conform to the rfb
1434spec but is traditional QEMU behavior.
1435
1436@item key-delay-ms
1437
1438Set keyboard delay, for key down and key up events, in milliseconds.
1439Default is 1.  Keyboards are low-bandwidth devices, so this slowdown
1440can help the device and guest to keep up and not lose events in case
1441events are arriving in bulk.  Possible causes for the latter are flaky
1442network connections, or scripts for automated testing.
1443
1444@end table
1445ETEXI
1446
1447STEXI
1448@end table
1449ETEXI
1450ARCHHEADING(, QEMU_ARCH_I386)
1451
1452ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1453STEXI
1454@table @option
1455ETEXI
1456
1457DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1458    "-win2k-hack     use it when installing Windows 2000 to avoid a disk full bug\n",
1459    QEMU_ARCH_I386)
1460STEXI
1461@item -win2k-hack
1462@findex -win2k-hack
1463Use it when installing Windows 2000 to avoid a disk full bug. After
1464Windows 2000 is installed, you no longer need this option (this option
1465slows down the IDE transfers).
1466ETEXI
1467
1468HXCOMM Deprecated by -rtc
1469DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1470
1471DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1472    "-no-fd-bootchk  disable boot signature checking for floppy disks\n",
1473    QEMU_ARCH_I386)
1474STEXI
1475@item -no-fd-bootchk
1476@findex -no-fd-bootchk
1477Disable boot signature checking for floppy disks in BIOS. May
1478be needed to boot from old floppy disks.
1479ETEXI
1480
1481DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1482           "-no-acpi        disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1483STEXI
1484@item -no-acpi
1485@findex -no-acpi
1486Disable ACPI (Advanced Configuration and Power Interface) support. Use
1487it if your guest OS complains about ACPI problems (PC target machine
1488only).
1489ETEXI
1490
1491DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1492    "-no-hpet        disable HPET\n", QEMU_ARCH_I386)
1493STEXI
1494@item -no-hpet
1495@findex -no-hpet
1496Disable HPET support.
1497ETEXI
1498
1499DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1500    "-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"
1501    "                ACPI table description\n", QEMU_ARCH_I386)
1502STEXI
1503@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}]...]
1504@findex -acpitable
1505Add ACPI table with specified header fields and context from specified files.
1506For file=, take whole ACPI table from the specified files, including all
1507ACPI headers (possible overridden by other options).
1508For data=, only data
1509portion of the table is used, all header information is specified in the
1510command line.
1511If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1512fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1513to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1514spec.
1515ETEXI
1516
1517DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1518    "-smbios file=binary\n"
1519    "                load SMBIOS entry from binary file\n"
1520    "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1521    "              [,uefi=on|off]\n"
1522    "                specify SMBIOS type 0 fields\n"
1523    "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1524    "              [,uuid=uuid][,sku=str][,family=str]\n"
1525    "                specify SMBIOS type 1 fields\n"
1526    "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1527    "              [,asset=str][,location=str]\n"
1528    "                specify SMBIOS type 2 fields\n"
1529    "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1530    "              [,sku=str]\n"
1531    "                specify SMBIOS type 3 fields\n"
1532    "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1533    "              [,asset=str][,part=str]\n"
1534    "                specify SMBIOS type 4 fields\n"
1535    "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1536    "               [,asset=str][,part=str][,speed=%d]\n"
1537    "                specify SMBIOS type 17 fields\n",
1538    QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1539STEXI
1540@item -smbios file=@var{binary}
1541@findex -smbios
1542Load SMBIOS entry from binary file.
1543
1544@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1545Specify SMBIOS type 0 fields
1546
1547@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}]
1548Specify SMBIOS type 1 fields
1549
1550@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}]
1551Specify SMBIOS type 2 fields
1552
1553@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1554Specify SMBIOS type 3 fields
1555
1556@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1557Specify SMBIOS type 4 fields
1558
1559@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}]
1560Specify SMBIOS type 17 fields
1561ETEXI
1562
1563STEXI
1564@end table
1565ETEXI
1566DEFHEADING()
1567
1568DEFHEADING(Network options:)
1569STEXI
1570@table @option
1571ETEXI
1572
1573HXCOMM Legacy slirp options (now moved to -net user):
1574#ifdef CONFIG_SLIRP
1575DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1576DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1577DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1578#ifndef _WIN32
1579DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1580#endif
1581#endif
1582
1583DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1584#ifdef CONFIG_SLIRP
1585    "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1586    "         [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1587    "         [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1588    "         [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
1589    "         [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1590#ifndef _WIN32
1591                                             "[,smb=dir[,smbserver=addr]]\n"
1592#endif
1593    "                configure a user mode network backend with ID 'str',\n"
1594    "                its DHCP server and optional services\n"
1595#endif
1596#ifdef _WIN32
1597    "-netdev tap,id=str,ifname=name\n"
1598    "                configure a host TAP network backend with ID 'str'\n"
1599#else
1600    "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1601    "         [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1602    "         [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1603    "         [,poll-us=n]\n"
1604    "                configure a host TAP network backend with ID 'str'\n"
1605    "                use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1606    "                to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1607    "                to deconfigure it\n"
1608    "                use '[down]script=no' to disable script execution\n"
1609    "                use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1610    "                configure it\n"
1611    "                use 'fd=h' to connect to an already opened TAP interface\n"
1612    "                use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1613    "                use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1614    "                default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1615    "                use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1616    "                use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1617    "                use vhost=on to enable experimental in kernel accelerator\n"
1618    "                    (only has effect for virtio guests which use MSIX)\n"
1619    "                use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1620    "                use 'vhostfd=h' to connect to an already opened vhost net device\n"
1621    "                use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1622    "                use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1623    "                use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1624    "                spent on busy polling for vhost net\n"
1625    "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1626    "                configure a host TAP network backend with ID 'str' that is\n"
1627    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1628    "                using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1629#endif
1630#ifdef __linux__
1631    "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1632    "         [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1633    "         [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1634    "         [,rxcookie=rxcookie][,offset=offset]\n"
1635    "                configure a network backend with ID 'str' connected to\n"
1636    "                an Ethernet over L2TPv3 pseudowire.\n"
1637    "                Linux kernel 3.3+ as well as most routers can talk\n"
1638    "                L2TPv3. This transport allows connecting a VM to a VM,\n"
1639    "                VM to a router and even VM to Host. It is a nearly-universal\n"
1640    "                standard (RFC3391). Note - this implementation uses static\n"
1641    "                pre-configured tunnels (same as the Linux kernel).\n"
1642    "                use 'src=' to specify source address\n"
1643    "                use 'dst=' to specify destination address\n"
1644    "                use 'udp=on' to specify udp encapsulation\n"
1645    "                use 'srcport=' to specify source udp port\n"
1646    "                use 'dstport=' to specify destination udp port\n"
1647    "                use 'ipv6=on' to force v6\n"
1648    "                L2TPv3 uses cookies to prevent misconfiguration as\n"
1649    "                well as a weak security measure\n"
1650    "                use 'rxcookie=0x012345678' to specify a rxcookie\n"
1651    "                use 'txcookie=0x012345678' to specify a txcookie\n"
1652    "                use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1653    "                use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1654    "                use 'pincounter=on' to work around broken counter handling in peer\n"
1655    "                use 'offset=X' to add an extra offset between header and data\n"
1656#endif
1657    "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1658    "                configure a network backend to connect to another network\n"
1659    "                using a socket connection\n"
1660    "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1661    "                configure a network backend to connect to a multicast maddr and port\n"
1662    "                use 'localaddr=addr' to specify the host address to send packets from\n"
1663    "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1664    "                configure a network backend to connect to another network\n"
1665    "                using an UDP tunnel\n"
1666#ifdef CONFIG_VDE
1667    "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1668    "                configure a network backend to connect to port 'n' of a vde switch\n"
1669    "                running on host and listening for incoming connections on 'socketpath'.\n"
1670    "                Use group 'groupname' and mode 'octalmode' to change default\n"
1671    "                ownership and permissions for communication port.\n"
1672#endif
1673#ifdef CONFIG_NETMAP
1674    "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1675    "                attach to the existing netmap-enabled network interface 'name', or to a\n"
1676    "                VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1677    "                netmap device, defaults to '/dev/netmap')\n"
1678#endif
1679    "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1680    "                configure a vhost-user network, backed by a chardev 'dev'\n"
1681    "-netdev hubport,id=str,hubid=n\n"
1682    "                configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
1683DEF("net", HAS_ARG, QEMU_OPTION_net,
1684    "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1685    "                old way to create a new NIC and connect it to VLAN 'n'\n"
1686    "                (use the '-device devtype,netdev=str' option if possible instead)\n"
1687    "-net dump[,vlan=n][,file=f][,len=n]\n"
1688    "                dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n"
1689    "-net none       use it alone to have zero network devices. If no -net option\n"
1690    "                is provided, the default is '-net nic -net user'\n"
1691    "-net ["
1692#ifdef CONFIG_SLIRP
1693    "user|"
1694#endif
1695    "tap|"
1696    "bridge|"
1697#ifdef CONFIG_VDE
1698    "vde|"
1699#endif
1700#ifdef CONFIG_NETMAP
1701    "netmap|"
1702#endif
1703    "socket][,vlan=n][,option][,option][,...]\n"
1704    "                old way to initialize a host network interface\n"
1705    "                (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
1706STEXI
1707@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1708@findex -net
1709Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1710= 0 is the default). The NIC is an e1000 by default on the PC
1711target. Optionally, the MAC address can be changed to @var{mac}, the
1712device address set to @var{addr} (PCI cards only),
1713and a @var{name} can be assigned for use in monitor commands.
1714Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1715that the card should have; this option currently only affects virtio cards; set
1716@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1717NIC is created.  QEMU can emulate several different models of network card.
1718Valid values for @var{type} are
1719@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1720@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1721@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1722Not all devices are supported on all targets.  Use @code{-net nic,model=help}
1723for a list of available devices for your target.
1724
1725@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1726@findex -netdev
1727@item -net user[,@var{option}][,@var{option}][,...]
1728Use the user mode network stack which requires no administrator
1729privilege to run. Valid options are:
1730
1731@table @option
1732@item vlan=@var{n}
1733Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1734
1735@item id=@var{id}
1736@itemx name=@var{name}
1737Assign symbolic name for use in monitor commands.
1738
1739@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
1740be enabled.  If neither is specified both protocols are enabled.
1741
1742@item net=@var{addr}[/@var{mask}]
1743Set IP network address the guest will see. Optionally specify the netmask,
1744either in the form a.b.c.d or as number of valid top-most bits. Default is
174510.0.2.0/24.
1746
1747@item host=@var{addr}
1748Specify the guest-visible address of the host. Default is the 2nd IP in the
1749guest network, i.e. x.x.x.2.
1750
1751@item ipv6-net=@var{addr}[/@var{int}]
1752Set IPv6 network address the guest will see (default is fec0::/64). The
1753network prefix is given in the usual hexadecimal IPv6 address
1754notation. The prefix size is optional, and is given as the number of
1755valid top-most bits (default is 64).
1756
1757@item ipv6-host=@var{addr}
1758Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
1759the guest network, i.e. xxxx::2.
1760
1761@item restrict=on|off
1762If this option is enabled, the guest will be isolated, i.e. it will not be
1763able to contact the host and no guest IP packets will be routed over the host
1764to the outside. This option does not affect any explicitly set forwarding rules.
1765
1766@item hostname=@var{name}
1767Specifies the client hostname reported by the built-in DHCP server.
1768
1769@item dhcpstart=@var{addr}
1770Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1771is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1772
1773@item dns=@var{addr}
1774Specify the guest-visible address of the virtual nameserver. The address must
1775be different from the host address. Default is the 3rd IP in the guest network,
1776i.e. x.x.x.3.
1777
1778@item ipv6-dns=@var{addr}
1779Specify the guest-visible address of the IPv6 virtual nameserver. The address
1780must be different from the host address. Default is the 3rd IP in the guest
1781network, i.e. xxxx::3.
1782
1783@item dnssearch=@var{domain}
1784Provides an entry for the domain-search list sent by the built-in
1785DHCP server. More than one domain suffix can be transmitted by specifying
1786this option multiple times. If supported, this will cause the guest to
1787automatically try to append the given domain suffix(es) in case a domain name
1788can not be resolved.
1789
1790Example:
1791@example
1792qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1793@end example
1794
1795@item tftp=@var{dir}
1796When using the user mode network stack, activate a built-in TFTP
1797server. The files in @var{dir} will be exposed as the root of a TFTP server.
1798The TFTP client on the guest must be configured in binary mode (use the command
1799@code{bin} of the Unix TFTP client).
1800
1801@item bootfile=@var{file}
1802When using the user mode network stack, broadcast @var{file} as the BOOTP
1803filename. In conjunction with @option{tftp}, this can be used to network boot
1804a guest from a local directory.
1805
1806Example (using pxelinux):
1807@example
1808qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1809@end example
1810
1811@item smb=@var{dir}[,smbserver=@var{addr}]
1812When using the user mode network stack, activate a built-in SMB
1813server so that Windows OSes can access to the host files in @file{@var{dir}}
1814transparently. The IP address of the SMB server can be set to @var{addr}. By
1815default the 4th IP in the guest network is used, i.e. x.x.x.4.
1816
1817In the guest Windows OS, the line:
1818@example
181910.0.2.4 smbserver
1820@end example
1821must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1822or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1823
1824Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1825
1826Note that a SAMBA server must be installed on the host OS.
1827QEMU was tested successfully with smbd versions from Red Hat 9,
1828Fedora Core 3 and OpenSUSE 11.x.
1829
1830@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1831Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1832the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1833@var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1834given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1835be bound to a specific host interface. If no connection type is set, TCP is
1836used. This option can be given multiple times.
1837
1838For example, to redirect host X11 connection from screen 1 to guest
1839screen 0, use the following:
1840
1841@example
1842# on the host
1843qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1844# this host xterm should open in the guest X11 server
1845xterm -display :1
1846@end example
1847
1848To redirect telnet connections from host port 5555 to telnet port on
1849the guest, use the following:
1850
1851@example
1852# on the host
1853qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1854telnet localhost 5555
1855@end example
1856
1857Then when you use on the host @code{telnet localhost 5555}, you
1858connect to the guest telnet server.
1859
1860@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1861@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1862Forward guest TCP connections to the IP address @var{server} on port @var{port}
1863to the character device @var{dev} or to a program executed by @var{cmd:command}
1864which gets spawned for each connection. This option can be given multiple times.
1865
1866You can either use a chardev directly and have that one used throughout QEMU's
1867lifetime, like in the following example:
1868
1869@example
1870# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
1871# the guest accesses it
1872qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
1873@end example
1874
1875Or you can execute a command on every TCP connection established by the guest,
1876so that QEMU behaves similar to an inetd process for that virtual server:
1877
1878@example
1879# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
1880# and connect the TCP stream to its stdin/stdout
1881qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1882@end example
1883
1884@end table
1885
1886Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1887processed and applied to -net user. Mixing them with the new configuration
1888syntax gives undefined results. Their use for new applications is discouraged
1889as they will be removed from future versions.
1890
1891@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1892@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1893Connect the host TAP network interface @var{name} to VLAN @var{n}.
1894
1895Use the network script @var{file} to configure it and the network script
1896@var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1897automatically provides one. The default network configure script is
1898@file{/etc/qemu-ifup} and the default network deconfigure script is
1899@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1900to disable script execution.
1901
1902If running QEMU as an unprivileged user, use the network helper
1903@var{helper} to configure the TAP interface. The default network
1904helper executable is @file{/path/to/qemu-bridge-helper}.
1905
1906@option{fd}=@var{h} can be used to specify the handle of an already
1907opened host TAP interface.
1908
1909Examples:
1910
1911@example
1912#launch a QEMU instance with the default network script
1913qemu-system-i386 linux.img -net nic -net tap
1914@end example
1915
1916@example
1917#launch a QEMU instance with two NICs, each one connected
1918#to a TAP device
1919qemu-system-i386 linux.img \
1920                 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1921                 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1922@end example
1923
1924@example
1925#launch a QEMU instance with the default network helper to
1926#connect a TAP device to bridge br0
1927qemu-system-i386 linux.img \
1928                 -net nic -net tap,"helper=/path/to/qemu-bridge-helper"
1929@end example
1930
1931@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
1932@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1933Connect a host TAP network interface to a host bridge device.
1934
1935Use the network helper @var{helper} to configure the TAP interface and
1936attach it to the bridge. The default network helper executable is
1937@file{/path/to/qemu-bridge-helper} and the default bridge
1938device is @file{br0}.
1939
1940Examples:
1941
1942@example
1943#launch a QEMU instance with the default network helper to
1944#connect a TAP device to bridge br0
1945qemu-system-i386 linux.img -net bridge -net nic,model=virtio
1946@end example
1947
1948@example
1949#launch a QEMU instance with the default network helper to
1950#connect a TAP device to bridge qemubr0
1951qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1952@end example
1953
1954@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1955@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1956
1957Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1958machine using a TCP socket connection. If @option{listen} is
1959specified, QEMU waits for incoming connections on @var{port}
1960(@var{host} is optional). @option{connect} is used to connect to
1961another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1962specifies an already opened TCP socket.
1963
1964Example:
1965@example
1966# launch a first QEMU instance
1967qemu-system-i386 linux.img \
1968                 -net nic,macaddr=52:54:00:12:34:56 \
1969                 -net socket,listen=:1234
1970# connect the VLAN 0 of this instance to the VLAN 0
1971# of the first instance
1972qemu-system-i386 linux.img \
1973                 -net nic,macaddr=52:54:00:12:34:57 \
1974                 -net socket,connect=127.0.0.1:1234
1975@end example
1976
1977@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1978@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1979
1980Create a VLAN @var{n} shared with another QEMU virtual
1981machines using a UDP multicast socket, effectively making a bus for
1982every QEMU with same multicast address @var{maddr} and @var{port}.
1983NOTES:
1984@enumerate
1985@item
1986Several QEMU can be running on different hosts and share same bus (assuming
1987correct multicast setup for these hosts).
1988@item
1989mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1990@url{http://user-mode-linux.sf.net}.
1991@item
1992Use @option{fd=h} to specify an already opened UDP multicast socket.
1993@end enumerate
1994
1995Example:
1996@example
1997# launch one QEMU instance
1998qemu-system-i386 linux.img \
1999                 -net nic,macaddr=52:54:00:12:34:56 \
2000                 -net socket,mcast=230.0.0.1:1234
2001# launch another QEMU instance on same "bus"
2002qemu-system-i386 linux.img \
2003                 -net nic,macaddr=52:54:00:12:34:57 \
2004                 -net socket,mcast=230.0.0.1:1234
2005# launch yet another QEMU instance on same "bus"
2006qemu-system-i386 linux.img \
2007                 -net nic,macaddr=52:54:00:12:34:58 \
2008                 -net socket,mcast=230.0.0.1:1234
2009@end example
2010
2011Example (User Mode Linux compat.):
2012@example
2013# launch QEMU instance (note mcast address selected
2014# is UML's default)
2015qemu-system-i386 linux.img \
2016                 -net nic,macaddr=52:54:00:12:34:56 \
2017                 -net socket,mcast=239.192.168.1:1102
2018# launch UML
2019/path/to/linux ubd0=/path/to/root_fs eth0=mcast
2020@end example
2021
2022Example (send packets from host's 1.2.3.4):
2023@example
2024qemu-system-i386 linux.img \
2025                 -net nic,macaddr=52:54:00:12:34:56 \
2026                 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2027@end example
2028
2029@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}]
2030@itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],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}]
2031Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
2032protocol to transport Ethernet (and other Layer 2) data frames between
2033two systems. It is present in routers, firewalls and the Linux kernel
2034(from version 3.3 onwards).
2035
2036This transport allows a VM to communicate to another VM, router or firewall directly.
2037
2038@item src=@var{srcaddr}
2039    source address (mandatory)
2040@item dst=@var{dstaddr}
2041    destination address (mandatory)
2042@item udp
2043    select udp encapsulation (default is ip).
2044@item srcport=@var{srcport}
2045    source udp port.
2046@item dstport=@var{dstport}
2047    destination udp port.
2048@item ipv6
2049    force v6, otherwise defaults to v4.
2050@item rxcookie=@var{rxcookie}
2051@itemx txcookie=@var{txcookie}
2052    Cookies are a weak form of security in the l2tpv3 specification.
2053Their function is mostly to prevent misconfiguration. By default they are 32
2054bit.
2055@item cookie64
2056    Set cookie size to 64 bit instead of the default 32
2057@item counter=off
2058    Force a 'cut-down' L2TPv3 with no counter as in
2059draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2060@item pincounter=on
2061    Work around broken counter handling in peer. This may also help on
2062networks which have packet reorder.
2063@item offset=@var{offset}
2064    Add an extra offset between header and data
2065
2066For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2067on the remote Linux host 1.2.3.4:
2068@example
2069# Setup tunnel on linux host using raw ip as encapsulation
2070# on 1.2.3.4
2071ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2072    encap udp udp_sport 16384 udp_dport 16384
2073ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2074    0xFFFFFFFF peer_session_id 0xFFFFFFFF
2075ifconfig vmtunnel0 mtu 1500
2076ifconfig vmtunnel0 up
2077brctl addif br-lan vmtunnel0
2078
2079
2080# on 4.3.2.1
2081# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2082
2083qemu-system-i386 linux.img -net nic -net l2tpv3,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2084
2085
2086@end example
2087
2088@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2089@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2090Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2091listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2092and MODE @var{octalmode} to change default ownership and permissions for
2093communication port. This option is only available if QEMU has been compiled
2094with vde support enabled.
2095
2096Example:
2097@example
2098# launch vde switch
2099vde_switch -F -sock /tmp/myswitch
2100# launch QEMU instance
2101qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2102@end example
2103
2104@item -netdev hubport,id=@var{id},hubid=@var{hubid}
2105
2106Create a hub port on QEMU "vlan" @var{hubid}.
2107
2108The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single
2109netdev.  @code{-net} and @code{-device} with parameter @option{vlan} create the
2110required hub automatically.
2111
2112@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2113
2114Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2115be a unix domain socket backed one. The vhost-user uses a specifically defined
2116protocol to pass vhost ioctl replacement messages to an application on the other
2117end of the socket. On non-MSIX guests, the feature can be forced with
2118@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2119be created for multiqueue vhost-user.
2120
2121Example:
2122@example
2123qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2124     -numa node,memdev=mem \
2125     -chardev socket,path=/path/to/socket \
2126     -netdev type=vhost-user,id=net0,chardev=chr0 \
2127     -device virtio-net-pci,netdev=net0
2128@end example
2129
2130@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
2131Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
2132At most @var{len} bytes (64k by default) per packet are stored. The file format is
2133libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
2134Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
2135
2136@item -net none
2137Indicate that no network devices should be configured. It is used to
2138override the default configuration (@option{-net nic -net user}) which
2139is activated if no @option{-net} options are provided.
2140ETEXI
2141
2142STEXI
2143@end table
2144ETEXI
2145DEFHEADING()
2146
2147DEFHEADING(Character device options:)
2148STEXI
2149
2150The general form of a character device option is:
2151@table @option
2152ETEXI
2153
2154DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2155    "-chardev help\n"
2156    "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2157    "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2158    "         [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2159    "         [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2160    "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2161    "         [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2162    "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2163    "         [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2164    "         [,logfile=PATH][,logappend=on|off]\n"
2165    "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2166    "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2167    "         [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2168    "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2169    "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2170    "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2171#ifdef _WIN32
2172    "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2173    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2174#else
2175    "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2176    "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2177#endif
2178#ifdef CONFIG_BRLAPI
2179    "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2180#endif
2181#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2182        || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2183    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2184    "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2185#endif
2186#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2187    "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2188    "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2189#endif
2190#if defined(CONFIG_SPICE)
2191    "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2192    "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2193#endif
2194    , QEMU_ARCH_ALL
2195)
2196
2197STEXI
2198@item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
2199@findex -chardev
2200Backend is one of:
2201@option{null},
2202@option{socket},
2203@option{udp},
2204@option{msmouse},
2205@option{vc},
2206@option{ringbuf},
2207@option{file},
2208@option{pipe},
2209@option{console},
2210@option{serial},
2211@option{pty},
2212@option{stdio},
2213@option{braille},
2214@option{tty},
2215@option{parallel},
2216@option{parport},
2217@option{spicevmc}.
2218@option{spiceport}.
2219The specific backend will determine the applicable options.
2220
2221Use "-chardev help" to print all available chardev backend types.
2222
2223All devices must have an id, which can be any string up to 127 characters long.
2224It is used to uniquely identify this device in other command line directives.
2225
2226A character device may be used in multiplexing mode by multiple front-ends.
2227Specify @option{mux=on} to enable this mode.
2228A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2229backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2230If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2231create a multiplexer with your specified ID, and you can then configure multiple
2232front ends to use that chardev ID for their input/output. Up to four different
2233front ends can be connected to a single multiplexed chardev. (Without
2234multiplexing enabled, a chardev can only be used by a single front end.)
2235For instance you could use this to allow a single stdio chardev to be used by
2236two serial ports and the QEMU monitor:
2237
2238@example
2239-chardev stdio,mux=on,id=char0 \
2240-mon chardev=char0,mode=readline,default \
2241-serial chardev:char0 \
2242-serial chardev:char0
2243@end example
2244
2245You can have more than one multiplexer in a system configuration; for instance
2246you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2247multiplexed between the QEMU monitor and a parallel port:
2248
2249@example
2250-chardev stdio,mux=on,id=char0 \
2251-mon chardev=char0,mode=readline,default \
2252-parallel chardev:char0 \
2253-chardev tcp,...,mux=on,id=char1 \
2254-serial chardev:char1 \
2255-serial chardev:char1
2256@end example
2257
2258When you're using a multiplexed character device, some escape sequences are
2259interpreted in the input. @xref{mux_keys, Keys in the character backend
2260multiplexer}.
2261
2262Note that some other command line options may implicitly create multiplexed
2263character backends; for instance @option{-serial mon:stdio} creates a
2264multiplexed stdio backend connected to the serial port and the QEMU monitor,
2265and @option{-nographic} also multiplexes the console and the monitor to
2266stdio.
2267
2268There is currently no support for multiplexing in the other direction
2269(where a single QEMU front end takes input and output from multiple chardevs).
2270
2271Every backend supports the @option{logfile} option, which supplies the path
2272to a file to record all data transmitted via the backend. The @option{logappend}
2273option controls whether the log file will be truncated or appended to when
2274opened.
2275
2276Further options to each backend are described below.
2277
2278@item -chardev null ,id=@var{id}
2279A void device. This device will not emit any data, and will drop any data it
2280receives. The null backend does not take any options.
2281
2282@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}]
2283
2284Create a two-way stream socket, which can be either a TCP or a unix socket. A
2285unix socket will be created if @option{path} is specified. Behaviour is
2286undefined if TCP options are specified for a unix socket.
2287
2288@option{server} specifies that the socket shall be a listening socket.
2289
2290@option{nowait} specifies that QEMU should not block waiting for a client to
2291connect to a listening socket.
2292
2293@option{telnet} specifies that traffic on the socket should interpret telnet
2294escape sequences.
2295
2296@option{reconnect} sets the timeout for reconnecting on non-server sockets when
2297the remote end goes away.  qemu will delay this many seconds and then attempt
2298to reconnect.  Zero disables reconnecting, and is the default.
2299
2300@option{tls-creds} requests enablement of the TLS protocol for encryption,
2301and specifies the id of the TLS credentials to use for the handshake. The
2302credentials must be previously created with the @option{-object tls-creds}
2303argument.
2304
2305TCP and unix socket options are given below:
2306
2307@table @option
2308
2309@item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2310
2311@option{host} for a listening socket specifies the local address to be bound.
2312For a connecting socket species the remote host to connect to. @option{host} is
2313optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2314
2315@option{port} for a listening socket specifies the local port to be bound. For a
2316connecting socket specifies the port on the remote host to connect to.
2317@option{port} can be given as either a port number or a service name.
2318@option{port} is required.
2319
2320@option{to} is only relevant to listening sockets. If it is specified, and
2321@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2322to and including @option{to} until it succeeds. @option{to} must be specified
2323as a port number.
2324
2325@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2326If neither is specified the socket may use either protocol.
2327
2328@option{nodelay} disables the Nagle algorithm.
2329
2330@item unix options: path=@var{path}
2331
2332@option{path} specifies the local path of the unix socket. @option{path} is
2333required.
2334
2335@end table
2336
2337@item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2338
2339Sends all traffic from the guest to a remote host over UDP.
2340
2341@option{host} specifies the remote host to connect to. If not specified it
2342defaults to @code{localhost}.
2343
2344@option{port} specifies the port on the remote host to connect to. @option{port}
2345is required.
2346
2347@option{localaddr} specifies the local address to bind to. If not specified it
2348defaults to @code{0.0.0.0}.
2349
2350@option{localport} specifies the local port to bind to. If not specified any
2351available local port will be used.
2352
2353@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2354If neither is specified the device may use either protocol.
2355
2356@item -chardev msmouse ,id=@var{id}
2357
2358Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2359take any options.
2360
2361@item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2362
2363Connect to a QEMU text console. @option{vc} may optionally be given a specific
2364size.
2365
2366@option{width} and @option{height} specify the width and height respectively of
2367the console, in pixels.
2368
2369@option{cols} and @option{rows} specify that the console be sized to fit a text
2370console with the given dimensions.
2371
2372@item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2373
2374Create a ring buffer with fixed size @option{size}.
2375@var{size} must be a power of two, and defaults to @code{64K}).
2376
2377@item -chardev file ,id=@var{id} ,path=@var{path}
2378
2379Log all traffic received from the guest to a file.
2380
2381@option{path} specifies the path of the file to be opened. This file will be
2382created if it does not already exist, and overwritten if it does. @option{path}
2383is required.
2384
2385@item -chardev pipe ,id=@var{id} ,path=@var{path}
2386
2387Create a two-way connection to the guest. The behaviour differs slightly between
2388Windows hosts and other hosts:
2389
2390On Windows, a single duplex pipe will be created at
2391@file{\\.pipe\@option{path}}.
2392
2393On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2394@file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2395received by the guest. Data written by the guest can be read from
2396@file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2397be present.
2398
2399@option{path} forms part of the pipe path as described above. @option{path} is
2400required.
2401
2402@item -chardev console ,id=@var{id}
2403
2404Send traffic from the guest to QEMU's standard output. @option{console} does not
2405take any options.
2406
2407@option{console} is only available on Windows hosts.
2408
2409@item -chardev serial ,id=@var{id} ,path=@option{path}
2410
2411Send traffic from the guest to a serial device on the host.
2412
2413On Unix hosts serial will actually accept any tty device,
2414not only serial lines.
2415
2416@option{path} specifies the name of the serial device to open.
2417
2418@item -chardev pty ,id=@var{id}
2419
2420Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2421not take any options.
2422
2423@option{pty} is not available on Windows hosts.
2424
2425@item -chardev stdio ,id=@var{id} [,signal=on|off]
2426Connect to standard input and standard output of the QEMU process.
2427
2428@option{signal} controls if signals are enabled on the terminal, that includes
2429exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2430default, use @option{signal=off} to disable it.
2431
2432@option{stdio} is not available on Windows hosts.
2433
2434@item -chardev braille ,id=@var{id}
2435
2436Connect to a local BrlAPI server. @option{braille} does not take any options.
2437
2438@item -chardev tty ,id=@var{id} ,path=@var{path}
2439
2440@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2441DragonFlyBSD hosts.  It is an alias for @option{serial}.
2442
2443@option{path} specifies the path to the tty. @option{path} is required.
2444
2445@item -chardev parallel ,id=@var{id} ,path=@var{path}
2446@itemx -chardev parport ,id=@var{id} ,path=@var{path}
2447
2448@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2449
2450Connect to a local parallel port.
2451
2452@option{path} specifies the path to the parallel port device. @option{path} is
2453required.
2454
2455@item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2456
2457@option{spicevmc} is only available when spice support is built in.
2458
2459@option{debug} debug level for spicevmc
2460
2461@option{name} name of spice channel to connect to
2462
2463Connect to a spice virtual machine channel, such as vdiport.
2464
2465@item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2466
2467@option{spiceport} is only available when spice support is built in.
2468
2469@option{debug} debug level for spicevmc
2470
2471@option{name} name of spice port to connect to
2472
2473Connect to a spice port, allowing a Spice client to handle the traffic
2474identified by a name (preferably a fqdn).
2475ETEXI
2476
2477STEXI
2478@end table
2479ETEXI
2480DEFHEADING()
2481
2482DEFHEADING(Device URL Syntax:)
2483STEXI
2484
2485In addition to using normal file images for the emulated storage devices,
2486QEMU can also use networked resources such as iSCSI devices. These are
2487specified using a special URL syntax.
2488
2489@table @option
2490@item iSCSI
2491iSCSI support allows QEMU to access iSCSI resources directly and use as
2492images for the guest storage. Both disk and cdrom images are supported.
2493
2494Syntax for specifying iSCSI LUNs is
2495``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2496
2497By default qemu will use the iSCSI initiator-name
2498'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2499line or a configuration file.
2500
2501Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2502stalled requests and force a reestablishment of the session. The timeout
2503is specified in seconds. The default is 0 which means no timeout. Libiscsi
25041.15.0 or greater is required for this feature.
2505
2506Example (without authentication):
2507@example
2508qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2509                 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2510                 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2511@end example
2512
2513Example (CHAP username/password via URL):
2514@example
2515qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2516@end example
2517
2518Example (CHAP username/password via environment variables):
2519@example
2520LIBISCSI_CHAP_USERNAME="user" \
2521LIBISCSI_CHAP_PASSWORD="password" \
2522qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2523@end example
2524
2525iSCSI support is an optional feature of QEMU and only available when
2526compiled and linked against libiscsi.
2527ETEXI
2528DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
2529    "-iscsi [user=user][,password=password]\n"
2530    "       [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2531    "       [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2532    "       [,timeout=timeout]\n"
2533    "                iSCSI session parameters\n", QEMU_ARCH_ALL)
2534STEXI
2535
2536iSCSI parameters such as username and password can also be specified via
2537a configuration file. See qemu-doc for more information and examples.
2538
2539@item NBD
2540QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2541as Unix Domain Sockets.
2542
2543Syntax for specifying a NBD device using TCP
2544``nbd:<server-ip>:<port>[:exportname=<export>]''
2545
2546Syntax for specifying a NBD device using Unix Domain Sockets
2547``nbd:unix:<domain-socket>[:exportname=<export>]''
2548
2549
2550Example for TCP
2551@example
2552qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2553@end example
2554
2555Example for Unix Domain Sockets
2556@example
2557qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2558@end example
2559
2560@item SSH
2561QEMU supports SSH (Secure Shell) access to remote disks.
2562
2563Examples:
2564@example
2565qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2566qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2567@end example
2568
2569Currently authentication must be done using ssh-agent.  Other
2570authentication methods may be supported in future.
2571
2572@item Sheepdog
2573Sheepdog is a distributed storage system for QEMU.
2574QEMU supports using either local sheepdog devices or remote networked
2575devices.
2576
2577Syntax for specifying a sheepdog device
2578@example
2579sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2580@end example
2581
2582Example
2583@example
2584qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2585@end example
2586
2587See also @url{http://http://www.osrg.net/sheepdog/}.
2588
2589@item GlusterFS
2590GlusterFS is an user space distributed file system.
2591QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2592TCP, Unix Domain Sockets and RDMA transport protocols.
2593
2594Syntax for specifying a VM disk image on GlusterFS volume is
2595@example
2596gluster[+transport]://[server[:port]]/volname/image[?socket=...]
2597@end example
2598
2599
2600Example
2601@example
2602qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img
2603@end example
2604
2605See also @url{http://www.gluster.org}.
2606
2607@item HTTP/HTTPS/FTP/FTPS/TFTP
2608QEMU supports read-only access to files accessed over http(s), ftp(s) and tftp.
2609
2610Syntax using a single filename:
2611@example
2612<protocol>://[<username>[:<password>]@@]<host>/<path>
2613@end example
2614
2615where:
2616@table @option
2617@item protocol
2618'http', 'https', 'ftp', 'ftps', or 'tftp'.
2619
2620@item username
2621Optional username for authentication to the remote server.
2622
2623@item password
2624Optional password for authentication to the remote server.
2625
2626@item host
2627Address of the remote server.
2628
2629@item path
2630Path on the remote server, including any query string.
2631@end table
2632
2633The following options are also supported:
2634@table @option
2635@item url
2636The full URL when passing options to the driver explicitly.
2637
2638@item readahead
2639The amount of data to read ahead with each range request to the remote server.
2640This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
2641does not have a suffix, it will be assumed to be in bytes. The value must be a
2642multiple of 512 bytes. It defaults to 256k.
2643
2644@item sslverify
2645Whether to verify the remote server's certificate when connecting over SSL. It
2646can have the value 'on' or 'off'. It defaults to 'on'.
2647
2648@item cookie
2649Send this cookie (it can also be a list of cookies separated by ';') with
2650each outgoing request.  Only supported when using protocols such as HTTP
2651which support cookies, otherwise ignored.
2652
2653@item timeout
2654Set the timeout in seconds of the CURL connection. This timeout is the time
2655that CURL waits for a response from the remote server to get the size of the
2656image to be downloaded. If not set, the default timeout of 5 seconds is used.
2657@end table
2658
2659Note that when passing options to qemu explicitly, @option{driver} is the value
2660of <protocol>.
2661
2662Example: boot from a remote Fedora 20 live ISO image
2663@example
2664qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2665
2666qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2667@end example
2668
2669Example: boot from a remote Fedora 20 cloud image using a local overlay for
2670writes, copy-on-read, and a readahead of 64k
2671@example
2672qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2
2673
2674qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
2675@end example
2676
2677Example: boot from an image stored on a VMware vSphere server with a self-signed
2678certificate using a local overlay for writes, a readahead of 64k and a timeout
2679of 10 seconds.
2680@example
2681qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@}' /tmp/test.qcow2
2682
2683qemu-system-x86_64 -drive file=/tmp/test.qcow2
2684@end example
2685ETEXI
2686
2687STEXI
2688@end table
2689ETEXI
2690
2691DEFHEADING(Bluetooth(R) options:)
2692STEXI
2693@table @option
2694ETEXI
2695
2696DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2697    "-bt hci,null    dumb bluetooth HCI - doesn't respond to commands\n" \
2698    "-bt hci,host[:id]\n" \
2699    "                use host's HCI with the given name\n" \
2700    "-bt hci[,vlan=n]\n" \
2701    "                emulate a standard HCI in virtual scatternet 'n'\n" \
2702    "-bt vhci[,vlan=n]\n" \
2703    "                add host computer to virtual scatternet 'n' using VHCI\n" \
2704    "-bt device:dev[,vlan=n]\n" \
2705    "                emulate a bluetooth device 'dev' in scatternet 'n'\n",
2706    QEMU_ARCH_ALL)
2707STEXI
2708@item -bt hci[...]
2709@findex -bt
2710Defines the function of the corresponding Bluetooth HCI.  -bt options
2711are matched with the HCIs present in the chosen machine type.  For
2712example when emulating a machine with only one HCI built into it, only
2713the first @code{-bt hci[...]} option is valid and defines the HCI's
2714logic.  The Transport Layer is decided by the machine type.  Currently
2715the machines @code{n800} and @code{n810} have one HCI and all other
2716machines have none.
2717
2718@anchor{bt-hcis}
2719The following three types are recognized:
2720
2721@table @option
2722@item -bt hci,null
2723(default) The corresponding Bluetooth HCI assumes no internal logic
2724and will not respond to any HCI commands or emit events.
2725
2726@item -bt hci,host[:@var{id}]
2727(@code{bluez} only) The corresponding HCI passes commands / events
2728to / from the physical HCI identified by the name @var{id} (default:
2729@code{hci0}) on the computer running QEMU.  Only available on @code{bluez}
2730capable systems like Linux.
2731
2732@item -bt hci[,vlan=@var{n}]
2733Add a virtual, standard HCI that will participate in the Bluetooth
2734scatternet @var{n} (default @code{0}).  Similarly to @option{-net}
2735VLANs, devices inside a bluetooth network @var{n} can only communicate
2736with other devices in the same network (scatternet).
2737@end table
2738
2739@item -bt vhci[,vlan=@var{n}]
2740(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2741to the host bluetooth stack instead of to the emulated target.  This
2742allows the host and target machines to participate in a common scatternet
2743and communicate.  Requires the Linux @code{vhci} driver installed.  Can
2744be used as following:
2745
2746@example
2747qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2748@end example
2749
2750@item -bt device:@var{dev}[,vlan=@var{n}]
2751Emulate a bluetooth device @var{dev} and place it in network @var{n}
2752(default @code{0}).  QEMU can only emulate one type of bluetooth devices
2753currently:
2754
2755@table @option
2756@item keyboard
2757Virtual wireless keyboard implementing the HIDP bluetooth profile.
2758@end table
2759ETEXI
2760
2761STEXI
2762@end table
2763ETEXI
2764DEFHEADING()
2765
2766#ifdef CONFIG_TPM
2767DEFHEADING(TPM device options:)
2768
2769DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2770    "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2771    "                use path to provide path to a character device; default is /dev/tpm0\n"
2772    "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2773    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n",
2774    QEMU_ARCH_ALL)
2775STEXI
2776
2777The general form of a TPM device option is:
2778@table @option
2779
2780@item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
2781@findex -tpmdev
2782Backend type must be:
2783@option{passthrough}.
2784
2785The specific backend type will determine the applicable options.
2786The @code{-tpmdev} option creates the TPM backend and requires a
2787@code{-device} option that specifies the TPM frontend interface model.
2788
2789Options to each backend are described below.
2790
2791Use 'help' to print all available TPM backend types.
2792@example
2793qemu -tpmdev help
2794@end example
2795
2796@item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
2797
2798(Linux-host only) Enable access to the host's TPM using the passthrough
2799driver.
2800
2801@option{path} specifies the path to the host's TPM device, i.e., on
2802a Linux host this would be @code{/dev/tpm0}.
2803@option{path} is optional and by default @code{/dev/tpm0} is used.
2804
2805@option{cancel-path} specifies the path to the host TPM device's sysfs
2806entry allowing for cancellation of an ongoing TPM command.
2807@option{cancel-path} is optional and by default QEMU will search for the
2808sysfs entry to use.
2809
2810Some notes about using the host's TPM with the passthrough driver:
2811
2812The TPM device accessed by the passthrough driver must not be
2813used by any other application on the host.
2814
2815Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2816the VM's firmware (BIOS/UEFI) will not be able to initialize the
2817TPM again and may therefore not show a TPM-specific menu that would
2818otherwise allow the user to configure the TPM, e.g., allow the user to
2819enable/disable or activate/deactivate the TPM.
2820Further, if TPM ownership is released from within a VM then the host's TPM
2821will get disabled and deactivated. To enable and activate the
2822TPM again afterwards, the host has to be rebooted and the user is
2823required to enter the firmware's menu to enable and activate the TPM.
2824If the TPM is left disabled and/or deactivated most TPM commands will fail.
2825
2826To create a passthrough TPM use the following two options:
2827@example
2828-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2829@end example
2830Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2831@code{tpmdev=tpm0} in the device option.
2832
2833@end table
2834
2835ETEXI
2836
2837DEFHEADING()
2838
2839#endif
2840
2841DEFHEADING(Linux/Multiboot boot specific:)
2842STEXI
2843
2844When using these options, you can use a given Linux or Multiboot
2845kernel without installing it in the disk image. It can be useful
2846for easier testing of various kernels.
2847
2848@table @option
2849ETEXI
2850
2851DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
2852    "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
2853STEXI
2854@item -kernel @var{bzImage}
2855@findex -kernel
2856Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2857or in multiboot format.
2858ETEXI
2859
2860DEF("append", HAS_ARG, QEMU_OPTION_append, \
2861    "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
2862STEXI
2863@item -append @var{cmdline}
2864@findex -append
2865Use @var{cmdline} as kernel command line
2866ETEXI
2867
2868DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
2869           "-initrd file    use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
2870STEXI
2871@item -initrd @var{file}
2872@findex -initrd
2873Use @var{file} as initial ram disk.
2874
2875@item -initrd "@var{file1} arg=foo,@var{file2}"
2876
2877This syntax is only available with multiboot.
2878
2879Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2880first module.
2881ETEXI
2882
2883DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
2884    "-dtb    file    use 'file' as device tree image\n", QEMU_ARCH_ALL)
2885STEXI
2886@item -dtb @var{file}
2887@findex -dtb
2888Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2889on boot.
2890ETEXI
2891
2892STEXI
2893@end table
2894ETEXI
2895DEFHEADING()
2896
2897DEFHEADING(Debug/Expert options:)
2898STEXI
2899@table @option
2900ETEXI
2901
2902DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
2903    "-fw_cfg [name=]<name>,file=<file>\n"
2904    "                add named fw_cfg entry with contents from file\n"
2905    "-fw_cfg [name=]<name>,string=<str>\n"
2906    "                add named fw_cfg entry with contents from string\n",
2907    QEMU_ARCH_ALL)
2908STEXI
2909
2910@item -fw_cfg [name=]@var{name},file=@var{file}
2911@findex -fw_cfg
2912Add named fw_cfg entry with contents from file @var{file}.
2913
2914@item -fw_cfg [name=]@var{name},string=@var{str}
2915Add named fw_cfg entry with contents from string @var{str}.
2916
2917The terminating NUL character of the contents of @var{str} will not be
2918included as part of the fw_cfg item data. To insert contents with
2919embedded NUL characters, you have to use the @var{file} parameter.
2920
2921The fw_cfg entries are passed by QEMU through to the guest.
2922
2923Example:
2924@example
2925    -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
2926@end example
2927creates an fw_cfg entry named opt/com.mycompany/blob with contents
2928from ./my_blob.bin.
2929
2930ETEXI
2931
2932DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
2933    "-serial dev     redirect the serial port to char device 'dev'\n",
2934    QEMU_ARCH_ALL)
2935STEXI
2936@item -serial @var{dev}
2937@findex -serial
2938Redirect the virtual serial port to host character device
2939@var{dev}. The default device is @code{vc} in graphical mode and
2940@code{stdio} in non graphical mode.
2941
2942This option can be used several times to simulate up to 4 serial
2943ports.
2944
2945Use @code{-serial none} to disable all serial ports.
2946
2947Available character devices are:
2948@table @option
2949@item vc[:@var{W}x@var{H}]
2950Virtual console. Optionally, a width and height can be given in pixel with
2951@example
2952vc:800x600
2953@end example
2954It is also possible to specify width or height in characters:
2955@example
2956vc:80Cx24C
2957@end example
2958@item pty
2959[Linux only] Pseudo TTY (a new PTY is automatically allocated)
2960@item none
2961No device is allocated.
2962@item null
2963void device
2964@item chardev:@var{id}
2965Use a named character device defined with the @code{-chardev} option.
2966@item /dev/XXX
2967[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
2968parameters are set according to the emulated ones.
2969@item /dev/parport@var{N}
2970[Linux only, parallel port only] Use host parallel port
2971@var{N}. Currently SPP and EPP parallel port features can be used.
2972@item file:@var{filename}
2973Write output to @var{filename}. No character can be read.
2974@item stdio
2975[Unix only] standard input/output
2976@item pipe:@var{filename}
2977name pipe @var{filename}
2978@item COM@var{n}
2979[Windows only] Use host serial port @var{n}
2980@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
2981This implements UDP Net Console.
2982When @var{remote_host} or @var{src_ip} are not specified
2983they default to @code{0.0.0.0}.
2984When not using a specified @var{src_port} a random port is automatically chosen.
2985
2986If you just want a simple readonly console you can use @code{netcat} or
2987@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
2988@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
2989will appear in the netconsole session.
2990
2991If you plan to send characters back via netconsole or you want to stop
2992and start QEMU a lot of times, you should have QEMU use the same
2993source port each time by using something like @code{-serial
2994udp::4555@@:4556} to QEMU. Another approach is to use a patched
2995version of netcat which can listen to a TCP port and send and receive
2996characters via udp.  If you have a patched version of netcat which
2997activates telnet remote echo and single char transfer, then you can
2998use the following options to step up a netcat redirector to allow
2999telnet on port 5555 to access the QEMU port.
3000@table @code
3001@item QEMU Options:
3002-serial udp::4555@@:4556
3003@item netcat options:
3004-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3005@item telnet options:
3006localhost 5555
3007@end table
3008
3009@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3010The TCP Net Console has two modes of operation.  It can send the serial
3011I/O to a location or wait for a connection from a location.  By default
3012the TCP Net Console is sent to @var{host} at the @var{port}.  If you use
3013the @var{server} option QEMU will wait for a client socket application
3014to connect to the port before continuing, unless the @code{nowait}
3015option was specified.  The @code{nodelay} option disables the Nagle buffering
3016algorithm.  The @code{reconnect} option only applies if @var{noserver} is
3017set, if the connection goes down it will attempt to reconnect at the
3018given interval.  If @var{host} is omitted, 0.0.0.0 is assumed. Only
3019one TCP connection at a time is accepted. You can use @code{telnet} to
3020connect to the corresponding character device.
3021@table @code
3022@item Example to send tcp console to 192.168.0.2 port 4444
3023-serial tcp:192.168.0.2:4444
3024@item Example to listen and wait on port 4444 for connection
3025-serial tcp::4444,server
3026@item Example to not wait and listen on ip 192.168.0.100 port 4444
3027-serial tcp:192.168.0.100:4444,server,nowait
3028@end table
3029
3030@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3031The telnet protocol is used instead of raw tcp sockets.  The options
3032work the same as if you had specified @code{-serial tcp}.  The
3033difference is that the port acts like a telnet server or client using
3034telnet option negotiation.  This will also allow you to send the
3035MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3036sequence.  Typically in unix telnet you do it with Control-] and then
3037type "send break" followed by pressing the enter key.
3038
3039@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3040A unix domain socket is used instead of a tcp socket.  The option works the
3041same as if you had specified @code{-serial tcp} except the unix domain socket
3042@var{path} is used for connections.
3043
3044@item mon:@var{dev_string}
3045This is a special option to allow the monitor to be multiplexed onto
3046another serial port.  The monitor is accessed with key sequence of
3047@key{Control-a} and then pressing @key{c}.
3048@var{dev_string} should be any one of the serial devices specified
3049above.  An example to multiplex the monitor onto a telnet server
3050listening on port 4444 would be:
3051@table @code
3052@item -serial mon:telnet::4444,server,nowait
3053@end table
3054When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3055QEMU any more but will be passed to the guest instead.
3056
3057@item braille
3058Braille device.  This will use BrlAPI to display the braille output on a real
3059or fake device.
3060
3061@item msmouse
3062Three button serial mouse. Configure the guest to use Microsoft protocol.
3063@end table
3064ETEXI
3065
3066DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3067    "-parallel dev   redirect the parallel port to char device 'dev'\n",
3068    QEMU_ARCH_ALL)
3069STEXI
3070@item -parallel @var{dev}
3071@findex -parallel
3072Redirect the virtual parallel port to host device @var{dev} (same
3073devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3074be used to use hardware devices connected on the corresponding host
3075parallel port.
3076
3077This option can be used several times to simulate up to 3 parallel
3078ports.
3079
3080Use @code{-parallel none} to disable all parallel ports.
3081ETEXI
3082
3083DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3084    "-monitor dev    redirect the monitor to char device 'dev'\n",
3085    QEMU_ARCH_ALL)
3086STEXI
3087@item -monitor @var{dev}
3088@findex -monitor
3089Redirect the monitor to host device @var{dev} (same devices as the
3090serial port).
3091The default device is @code{vc} in graphical mode and @code{stdio} in
3092non graphical mode.
3093Use @code{-monitor none} to disable the default monitor.
3094ETEXI
3095DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3096    "-qmp dev        like -monitor but opens in 'control' mode\n",
3097    QEMU_ARCH_ALL)
3098STEXI
3099@item -qmp @var{dev}
3100@findex -qmp
3101Like -monitor but opens in 'control' mode.
3102ETEXI
3103DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3104    "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3105    QEMU_ARCH_ALL)
3106STEXI
3107@item -qmp-pretty @var{dev}
3108@findex -qmp-pretty
3109Like -qmp but uses pretty JSON formatting.
3110ETEXI
3111
3112DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3113    "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL)
3114STEXI
3115@item -mon [chardev=]name[,mode=readline|control][,default]
3116@findex -mon
3117Setup monitor on chardev @var{name}.
3118ETEXI
3119
3120DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3121    "-debugcon dev   redirect the debug console to char device 'dev'\n",
3122    QEMU_ARCH_ALL)
3123STEXI
3124@item -debugcon @var{dev}
3125@findex -debugcon
3126Redirect the debug console to host device @var{dev} (same devices as the
3127serial port).  The debug console is an I/O port which is typically port
31280xe9; writing to that I/O port sends output to this device.
3129The default device is @code{vc} in graphical mode and @code{stdio} in
3130non graphical mode.
3131ETEXI
3132
3133DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3134    "-pidfile file   write PID to 'file'\n", QEMU_ARCH_ALL)
3135STEXI
3136@item -pidfile @var{file}
3137@findex -pidfile
3138Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3139from a script.
3140ETEXI
3141
3142DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3143    "-singlestep     always run in singlestep mode\n", QEMU_ARCH_ALL)
3144STEXI
3145@item -singlestep
3146@findex -singlestep
3147Run the emulation in single step mode.
3148ETEXI
3149
3150DEF("S", 0, QEMU_OPTION_S, \
3151    "-S              freeze CPU at startup (use 'c' to start execution)\n",
3152    QEMU_ARCH_ALL)
3153STEXI
3154@item -S
3155@findex -S
3156Do not start CPU at startup (you must type 'c' in the monitor).
3157ETEXI
3158
3159DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3160    "-realtime [mlock=on|off]\n"
3161    "                run qemu with realtime features\n"
3162    "                mlock=on|off controls mlock support (default: on)\n",
3163    QEMU_ARCH_ALL)
3164STEXI
3165@item -realtime mlock=on|off
3166@findex -realtime
3167Run qemu with realtime features.
3168mlocking qemu and guest memory can be enabled via @option{mlock=on}
3169(enabled by default).
3170ETEXI
3171
3172DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3173    "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3174STEXI
3175@item -gdb @var{dev}
3176@findex -gdb
3177Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3178connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3179stdio are reasonable use case. The latter is allowing to start QEMU from
3180within gdb and establish the connection via a pipe:
3181@example
3182(gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3183@end example
3184ETEXI
3185
3186DEF("s", 0, QEMU_OPTION_s, \
3187    "-s              shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3188    QEMU_ARCH_ALL)
3189STEXI
3190@item -s
3191@findex -s
3192Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3193(@pxref{gdb_usage}).
3194ETEXI
3195
3196DEF("d", HAS_ARG, QEMU_OPTION_d, \
3197    "-d item1,...    enable logging of specified items (use '-d help' for a list of log items)\n",
3198    QEMU_ARCH_ALL)
3199STEXI
3200@item -d @var{item1}[,...]
3201@findex -d
3202Enable logging of specified items. Use '-d help' for a list of log items.
3203ETEXI
3204
3205DEF("D", HAS_ARG, QEMU_OPTION_D, \
3206    "-D logfile      output log to logfile (default stderr)\n",
3207    QEMU_ARCH_ALL)
3208STEXI
3209@item -D @var{logfile}
3210@findex -D
3211Output log in @var{logfile} instead of to stderr
3212ETEXI
3213
3214DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3215    "-dfilter range,..  filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3216    QEMU_ARCH_ALL)
3217STEXI
3218@item -dfilter @var{range1}[,...]
3219@findex -dfilter
3220Filter debug output to that relevant to a range of target addresses. The filter
3221spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3222@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3223addresses and sizes required. For example:
3224@example
3225    -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3226@end example
3227Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3228the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3229block starting at 0xffffffc00005f000.
3230ETEXI
3231
3232DEF("L", HAS_ARG, QEMU_OPTION_L, \
3233    "-L path         set the directory for the BIOS, VGA BIOS and keymaps\n",
3234    QEMU_ARCH_ALL)
3235STEXI
3236@item -L  @var{path}
3237@findex -L
3238Set the directory for the BIOS, VGA BIOS and keymaps.
3239
3240To list all the data directories, use @code{-L help}.
3241ETEXI
3242
3243DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3244    "-bios file      set the filename for the BIOS\n", QEMU_ARCH_ALL)
3245STEXI
3246@item -bios @var{file}
3247@findex -bios
3248Set the filename for the BIOS.
3249ETEXI
3250
3251DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3252    "-enable-kvm     enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3253STEXI
3254@item -enable-kvm
3255@findex -enable-kvm
3256Enable KVM full virtualization support. This option is only available
3257if KVM support is enabled when compiling.
3258ETEXI
3259
3260DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3261    "-xen-domid id   specify xen guest domain id\n", QEMU_ARCH_ALL)
3262DEF("xen-create", 0, QEMU_OPTION_xen_create,
3263    "-xen-create     create domain using xen hypercalls, bypassing xend\n"
3264    "                warning: should not be used when xend is in use\n",
3265    QEMU_ARCH_ALL)
3266DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3267    "-xen-attach     attach to existing xen domain\n"
3268    "                xend will use this when starting QEMU\n",
3269    QEMU_ARCH_ALL)
3270STEXI
3271@item -xen-domid @var{id}
3272@findex -xen-domid
3273Specify xen guest domain @var{id} (XEN only).
3274@item -xen-create
3275@findex -xen-create
3276Create domain using xen hypercalls, bypassing xend.
3277Warning: should not be used when xend is in use (XEN only).
3278@item -xen-attach
3279@findex -xen-attach
3280Attach to existing xen domain.
3281xend will use this when starting QEMU (XEN only).
3282ETEXI
3283
3284DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3285    "-no-reboot      exit instead of rebooting\n", QEMU_ARCH_ALL)
3286STEXI
3287@item -no-reboot
3288@findex -no-reboot
3289Exit instead of rebooting.
3290ETEXI
3291
3292DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3293    "-no-shutdown    stop before shutdown\n", QEMU_ARCH_ALL)
3294STEXI
3295@item -no-shutdown
3296@findex -no-shutdown
3297Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3298This allows for instance switching to monitor to commit changes to the
3299disk image.
3300ETEXI
3301
3302DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3303    "-loadvm [tag|id]\n" \
3304    "                start right away with a saved state (loadvm in monitor)\n",
3305    QEMU_ARCH_ALL)
3306STEXI
3307@item -loadvm @var{file}
3308@findex -loadvm
3309Start right away with a saved state (@code{loadvm} in monitor)
3310ETEXI
3311
3312#ifndef _WIN32
3313DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3314    "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3315#endif
3316STEXI
3317@item -daemonize
3318@findex -daemonize
3319Daemonize the QEMU process after initialization.  QEMU will not detach from
3320standard IO until it is ready to receive connections on any of its devices.
3321This option is a useful way for external programs to launch QEMU without having
3322to cope with initialization race conditions.
3323ETEXI
3324
3325DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3326    "-option-rom rom load a file, rom, into the option ROM space\n",
3327    QEMU_ARCH_ALL)
3328STEXI
3329@item -option-rom @var{file}
3330@findex -option-rom
3331Load the contents of @var{file} as an option ROM.
3332This option is useful to load things like EtherBoot.
3333ETEXI
3334
3335HXCOMM Silently ignored for compatibility
3336DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3337
3338HXCOMM Options deprecated by -rtc
3339DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3340DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3341
3342DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3343    "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3344    "                set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3345    QEMU_ARCH_ALL)
3346
3347STEXI
3348
3349@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3350@findex -rtc
3351Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3352UTC or local time, respectively. @code{localtime} is required for correct date in
3353MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3354format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3355
3356By default the RTC is driven by the host system time. This allows using of the
3357RTC as accurate reference clock inside the guest, specifically if the host
3358time is smoothly following an accurate external reference clock, e.g. via NTP.
3359If you want to isolate the guest time from the host, you can set @option{clock}
3360to @code{rt} instead.  To even prevent it from progressing during suspension,
3361you can set it to @code{vm}.
3362
3363Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3364specifically with Windows' ACPI HAL. This option will try to figure out how
3365many timer interrupts were not processed by the Windows guest and will
3366re-inject them.
3367ETEXI
3368
3369DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3370    "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>]\n" \
3371    "                enable virtual instruction counter with 2^N clock ticks per\n" \
3372    "                instruction, enable aligning the host and virtual clocks\n" \
3373    "                or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3374STEXI
3375@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename}]
3376@findex -icount
3377Enable virtual instruction counter.  The virtual cpu will execute one
3378instruction every 2^@var{N} ns of virtual time.  If @code{auto} is specified
3379then the virtual cpu speed will be automatically adjusted to keep virtual
3380time within a few seconds of real time.
3381
3382When the virtual cpu is sleeping, the virtual time will advance at default
3383speed unless @option{sleep=on|off} is specified.
3384With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3385instantly whenever the virtual cpu goes to sleep mode and will not advance
3386if no timer is enabled. This behavior give deterministic execution times from
3387the guest point of view.
3388
3389Note that while this option can give deterministic behavior, it does not
3390provide cycle accurate emulation.  Modern CPUs contain superscalar out of
3391order cores with complex cache hierarchies.  The number of instructions
3392executed often has little or no correlation with actual performance.
3393
3394@option{align=on} will activate the delay algorithm which will try
3395to synchronise the host clock and the virtual clock. The goal is to
3396have a guest running at the real frequency imposed by the shift option.
3397Whenever the guest clock is behind the host clock and if
3398@option{align=on} is specified then we print a message to the user
3399to inform about the delay.
3400Currently this option does not work when @option{shift} is @code{auto}.
3401Note: The sync algorithm will work for those shift values for which
3402the guest clock runs ahead of the host clock. Typically this happens
3403when the shift value is high (how high depends on the host machine).
3404
3405When @option{rr} option is specified deterministic record/replay is enabled.
3406Replay log is written into @var{filename} file in record mode and
3407read from this file in replay mode.
3408ETEXI
3409
3410DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3411    "-watchdog model\n" \
3412    "                enable virtual hardware watchdog [default=none]\n",
3413    QEMU_ARCH_ALL)
3414STEXI
3415@item -watchdog @var{model}
3416@findex -watchdog
3417Create a virtual hardware watchdog device.  Once enabled (by a guest
3418action), the watchdog must be periodically polled by an agent inside
3419the guest or else the guest will be restarted. Choose a model for
3420which your guest has drivers.
3421
3422The @var{model} is the model of hardware watchdog to emulate. Use
3423@code{-watchdog help} to list available hardware models. Only one
3424watchdog can be enabled for a guest.
3425
3426The following models may be available:
3427@table @option
3428@item ib700
3429iBASE 700 is a very simple ISA watchdog with a single timer.
3430@item i6300esb
3431Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3432dual-timer watchdog.
3433@item diag288
3434A virtual watchdog for s390x backed by the diagnose 288 hypercall
3435(currently KVM only).
3436@end table
3437ETEXI
3438
3439DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3440    "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3441    "                action when watchdog fires [default=reset]\n",
3442    QEMU_ARCH_ALL)
3443STEXI
3444@item -watchdog-action @var{action}
3445@findex -watchdog-action
3446
3447The @var{action} controls what QEMU will do when the watchdog timer
3448expires.
3449The default is
3450@code{reset} (forcefully reset the guest).
3451Other possible actions are:
3452@code{shutdown} (attempt to gracefully shutdown the guest),
3453@code{poweroff} (forcefully poweroff the guest),
3454@code{pause} (pause the guest),
3455@code{debug} (print a debug message and continue), or
3456@code{none} (do nothing).
3457
3458Note that the @code{shutdown} action requires that the guest responds
3459to ACPI signals, which it may not be able to do in the sort of
3460situations where the watchdog would have expired, and thus
3461@code{-watchdog-action shutdown} is not recommended for production use.
3462
3463Examples:
3464
3465@table @code
3466@item -watchdog i6300esb -watchdog-action pause
3467@itemx -watchdog ib700
3468@end table
3469ETEXI
3470
3471DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3472    "-echr chr       set terminal escape character instead of ctrl-a\n",
3473    QEMU_ARCH_ALL)
3474STEXI
3475
3476@item -echr @var{numeric_ascii_value}
3477@findex -echr
3478Change the escape character used for switching to the monitor when using
3479monitor and serial sharing.  The default is @code{0x01} when using the
3480@code{-nographic} option.  @code{0x01} is equal to pressing
3481@code{Control-a}.  You can select a different character from the ascii
3482control keys where 1 through 26 map to Control-a through Control-z.  For
3483instance you could use the either of the following to change the escape
3484character to Control-t.
3485@table @code
3486@item -echr 0x14
3487@itemx -echr 20
3488@end table
3489ETEXI
3490
3491DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3492    "-virtioconsole c\n" \
3493    "                set virtio console\n", QEMU_ARCH_ALL)
3494STEXI
3495@item -virtioconsole @var{c}
3496@findex -virtioconsole
3497Set virtio console.
3498
3499This option is maintained for backward compatibility.
3500
3501Please use @code{-device virtconsole} for the new way of invocation.
3502ETEXI
3503
3504DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3505    "-show-cursor    show cursor\n", QEMU_ARCH_ALL)
3506STEXI
3507@item -show-cursor
3508@findex -show-cursor
3509Show cursor.
3510ETEXI
3511
3512DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3513    "-tb-size n      set TB size\n", QEMU_ARCH_ALL)
3514STEXI
3515@item -tb-size @var{n}
3516@findex -tb-size
3517Set TB size.
3518ETEXI
3519
3520DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3521    "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3522    "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3523    "-incoming unix:socketpath\n" \
3524    "                prepare for incoming migration, listen on\n" \
3525    "                specified protocol and socket address\n" \
3526    "-incoming fd:fd\n" \
3527    "-incoming exec:cmdline\n" \
3528    "                accept incoming migration on given file descriptor\n" \
3529    "                or from given external command\n" \
3530    "-incoming defer\n" \
3531    "                wait for the URI to be specified via migrate_incoming\n",
3532    QEMU_ARCH_ALL)
3533STEXI
3534@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3535@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3536@findex -incoming
3537Prepare for incoming migration, listen on a given tcp port.
3538
3539@item -incoming unix:@var{socketpath}
3540Prepare for incoming migration, listen on a given unix socket.
3541
3542@item -incoming fd:@var{fd}
3543Accept incoming migration from a given filedescriptor.
3544
3545@item -incoming exec:@var{cmdline}
3546Accept incoming migration as an output from specified external command.
3547
3548@item -incoming defer
3549Wait for the URI to be specified via migrate_incoming.  The monitor can
3550be used to change settings (such as migration parameters) prior to issuing
3551the migrate_incoming to allow the migration to begin.
3552ETEXI
3553
3554DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3555    "-nodefaults     don't create default devices\n", QEMU_ARCH_ALL)
3556STEXI
3557@item -nodefaults
3558@findex -nodefaults
3559Don't create default devices. Normally, QEMU sets the default devices like serial
3560port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3561CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3562default devices.
3563ETEXI
3564
3565#ifndef _WIN32
3566DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3567    "-chroot dir     chroot to dir just before starting the VM\n",
3568    QEMU_ARCH_ALL)
3569#endif
3570STEXI
3571@item -chroot @var{dir}
3572@findex -chroot
3573Immediately before starting guest execution, chroot to the specified
3574directory.  Especially useful in combination with -runas.
3575ETEXI
3576
3577#ifndef _WIN32
3578DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3579    "-runas user     change to user id user just before starting the VM\n",
3580    QEMU_ARCH_ALL)
3581#endif
3582STEXI
3583@item -runas @var{user}
3584@findex -runas
3585Immediately before starting guest execution, drop root privileges, switching
3586to the specified user.
3587ETEXI
3588
3589DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3590    "-prom-env variable=value\n"
3591    "                set OpenBIOS nvram variables\n",
3592    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3593STEXI
3594@item -prom-env @var{variable}=@var{value}
3595@findex -prom-env
3596Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3597ETEXI
3598DEF("semihosting", 0, QEMU_OPTION_semihosting,
3599    "-semihosting    semihosting mode\n",
3600    QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3601    QEMU_ARCH_MIPS)
3602STEXI
3603@item -semihosting
3604@findex -semihosting
3605Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3606ETEXI
3607DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3608    "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3609    "                semihosting configuration\n",
3610QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3611QEMU_ARCH_MIPS)
3612STEXI
3613@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3614@findex -semihosting-config
3615Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3616@table @option
3617@item target=@code{native|gdb|auto}
3618Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3619or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3620during debug sessions and @code{native} otherwise.
3621@item arg=@var{str1},arg=@var{str2},...
3622Allows the user to pass input arguments, and can be used multiple times to build
3623up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3624command line is still supported for backward compatibility. If both the
3625@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3626specified, the former is passed to semihosting as it always takes precedence.
3627@end table
3628ETEXI
3629DEF("old-param", 0, QEMU_OPTION_old_param,
3630    "-old-param      old param mode\n", QEMU_ARCH_ARM)
3631STEXI
3632@item -old-param
3633@findex -old-param (ARM)
3634Old param mode (ARM only).
3635ETEXI
3636
3637DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3638    "-sandbox <arg>  Enable seccomp mode 2 system call filter (default 'off').\n",
3639    QEMU_ARCH_ALL)
3640STEXI
3641@item -sandbox @var{arg}
3642@findex -sandbox
3643Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3644disable it.  The default is 'off'.
3645ETEXI
3646
3647DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3648    "-readconfig <file>\n", QEMU_ARCH_ALL)
3649STEXI
3650@item -readconfig @var{file}
3651@findex -readconfig
3652Read device configuration from @var{file}. This approach is useful when you want to spawn
3653QEMU process with many command line options but you don't want to exceed the command line
3654character limit.
3655ETEXI
3656DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3657    "-writeconfig <file>\n"
3658    "                read/write config file\n", QEMU_ARCH_ALL)
3659STEXI
3660@item -writeconfig @var{file}
3661@findex -writeconfig
3662Write device configuration to @var{file}. The @var{file} can be either filename to save
3663command line and device configuration into file or dash @code{-}) character to print the
3664output to stdout. This can be later used as input file for @code{-readconfig} option.
3665ETEXI
3666DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
3667    "-nodefconfig\n"
3668    "                do not load default config files at startup\n",
3669    QEMU_ARCH_ALL)
3670STEXI
3671@item -nodefconfig
3672@findex -nodefconfig
3673Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
3674The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
3675ETEXI
3676DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3677    "-no-user-config\n"
3678    "                do not load user-provided config files at startup\n",
3679    QEMU_ARCH_ALL)
3680STEXI
3681@item -no-user-config
3682@findex -no-user-config
3683The @code{-no-user-config} option makes QEMU not load any of the user-provided
3684config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config
3685files from @var{datadir}.
3686ETEXI
3687DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3688    "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3689    "                specify tracing options\n",
3690    QEMU_ARCH_ALL)
3691STEXI
3692HXCOMM This line is not accurate, as some sub-options are backend-specific but
3693HXCOMM HX does not support conditional compilation of text.
3694@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3695@findex -trace
3696@include qemu-option-trace.texi
3697ETEXI
3698
3699HXCOMM Internal use
3700DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3701DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3702
3703#ifdef __linux__
3704DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3705    "-enable-fips    enable FIPS 140-2 compliance\n",
3706    QEMU_ARCH_ALL)
3707#endif
3708STEXI
3709@item -enable-fips
3710@findex -enable-fips
3711Enable FIPS 140-2 compliance mode.
3712ETEXI
3713
3714HXCOMM Deprecated by -machine accel=tcg property
3715DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3716
3717HXCOMM Deprecated by kvm-pit driver properties
3718DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3719    "", QEMU_ARCH_I386)
3720
3721HXCOMM Deprecated (ignored)
3722DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
3723
3724HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3725DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3726
3727HXCOMM Deprecated (ignored)
3728DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3729
3730DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3731    "-msg timestamp[=on|off]\n"
3732    "                change the format of messages\n"
3733    "                on|off controls leading timestamps (default:on)\n",
3734    QEMU_ARCH_ALL)
3735STEXI
3736@item -msg timestamp[=on|off]
3737@findex -msg
3738prepend a timestamp to each log message.(default:on)
3739ETEXI
3740
3741DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3742    "-dump-vmstate <file>\n"
3743    "                Output vmstate information in JSON format to file.\n"
3744    "                Use the scripts/vmstate-static-checker.py file to\n"
3745    "                check for possible regressions in migration code\n"
3746    "                by comparing two such vmstate dumps.\n",
3747    QEMU_ARCH_ALL)
3748STEXI
3749@item -dump-vmstate @var{file}
3750@findex -dump-vmstate
3751Dump json-encoded vmstate information for current machine type to file
3752in @var{file}
3753ETEXI
3754
3755DEFHEADING(Generic object creation)
3756
3757DEF("object", HAS_ARG, QEMU_OPTION_object,
3758    "-object TYPENAME[,PROP1=VALUE1,...]\n"
3759    "                create a new object of type TYPENAME setting properties\n"
3760    "                in the order they are specified.  Note that the 'id'\n"
3761    "                property must be set.  These objects are placed in the\n"
3762    "                '/objects' path.\n",
3763    QEMU_ARCH_ALL)
3764STEXI
3765@item -object @var{typename}[,@var{prop1}=@var{value1},...]
3766@findex -object
3767Create a new object of type @var{typename} setting properties
3768in the order they are specified.  Note that the 'id'
3769property must be set.  These objects are placed in the
3770'/objects' path.
3771
3772@table @option
3773
3774@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off}
3775
3776Creates a memory file backend object, which can be used to back
3777the guest RAM with huge pages. The @option{id} parameter is a
3778unique ID that will be used to reference this memory region
3779when configuring the @option{-numa} argument. The @option{size}
3780option provides the size of the memory region, and accepts
3781common suffixes, eg @option{500M}. The @option{mem-path} provides
3782the path to either a shared memory or huge page filesystem mount.
3783The @option{share} boolean option determines whether the memory
3784region is marked as private to QEMU, or shared. The latter allows
3785a co-operating external process to access the QEMU memory region.
3786
3787@item -object rng-random,id=@var{id},filename=@var{/dev/random}
3788
3789Creates a random number generator backend which obtains entropy from
3790a device on the host. The @option{id} parameter is a unique ID that
3791will be used to reference this entropy backend from the @option{virtio-rng}
3792device. The @option{filename} parameter specifies which file to obtain
3793entropy from and if omitted defaults to @option{/dev/random}.
3794
3795@item -object rng-egd,id=@var{id},chardev=@var{chardevid}
3796
3797Creates a random number generator backend which obtains entropy from
3798an external daemon running on the host. The @option{id} parameter is
3799a unique ID that will be used to reference this entropy backend from
3800the @option{virtio-rng} device. The @option{chardev} parameter is
3801the unique ID of a character device backend that provides the connection
3802to the RNG daemon.
3803
3804@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
3805
3806Creates a TLS anonymous credentials object, which can be used to provide
3807TLS support on network backends. The @option{id} parameter is a unique
3808ID which network backends will use to access the credentials. The
3809@option{endpoint} is either @option{server} or @option{client} depending
3810on whether the QEMU network backend that uses the credentials will be
3811acting as a client or as a server. If @option{verify-peer} is enabled
3812(the default) then once the handshake is completed, the peer credentials
3813will be verified, though this is a no-op for anonymous credentials.
3814
3815The @var{dir} parameter tells QEMU where to find the credential
3816files. For server endpoints, this directory may contain a file
3817@var{dh-params.pem} providing diffie-hellman parameters to use
3818for the TLS server. If the file is missing, QEMU will generate
3819a set of DH parameters at startup. This is a computationally
3820expensive operation that consumes random pool entropy, so it is
3821recommended that a persistent set of parameters be generated
3822upfront and saved.
3823
3824@item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off},passwordid=@var{id}
3825
3826Creates a TLS anonymous credentials object, which can be used to provide
3827TLS support on network backends. The @option{id} parameter is a unique
3828ID which network backends will use to access the credentials. The
3829@option{endpoint} is either @option{server} or @option{client} depending
3830on whether the QEMU network backend that uses the credentials will be
3831acting as a client or as a server. If @option{verify-peer} is enabled
3832(the default) then once the handshake is completed, the peer credentials
3833will be verified. With x509 certificates, this implies that the clients
3834must be provided with valid client certificates too.
3835
3836The @var{dir} parameter tells QEMU where to find the credential
3837files. For server endpoints, this directory may contain a file
3838@var{dh-params.pem} providing diffie-hellman parameters to use
3839for the TLS server. If the file is missing, QEMU will generate
3840a set of DH parameters at startup. This is a computationally
3841expensive operation that consumes random pool entropy, so it is
3842recommended that a persistent set of parameters be generated
3843upfront and saved.
3844
3845For x509 certificate credentials the directory will contain further files
3846providing the x509 certificates. The certificates must be stored
3847in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
3848@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
3849@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
3850
3851For the @var{server-key.pem} and @var{client-key.pem} files which
3852contain sensitive private keys, it is possible to use an encrypted
3853version by providing the @var{passwordid} parameter. This provides
3854the ID of a previously created @code{secret} object containing the
3855password for decryption.
3856
3857@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
3858
3859Interval @var{t} can't be 0, this filter batches the packet delivery: all
3860packets arriving in a given interval on netdev @var{netdevid} are delayed
3861until the end of the interval. Interval is in microseconds.
3862@option{status} is optional that indicate whether the netfilter is
3863on (enabled) or off (disabled), the default status for netfilter will be 'on'.
3864
3865queue @var{all|rx|tx} is an option that can be applied to any netfilter.
3866
3867@option{all}: the filter is attached both to the receive and the transmit
3868              queue of the netdev (default).
3869
3870@option{rx}: the filter is attached to the receive queue of the netdev,
3871             where it will receive packets sent to the netdev.
3872
3873@option{tx}: the filter is attached to the transmit queue of the netdev,
3874             where it will receive packets sent by the netdev.
3875
3876@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
3877
3878filter-mirror on netdev @var{netdevid},mirror net packet to chardev
3879@var{chardevid}
3880
3881@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},
3882outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
3883
3884filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
3885@var{chardevid},and redirect indev's packet to filter.
3886Create a filter-redirector we need to differ outdev id from indev id, id can not
3887be the same. we can just use indev or outdev, but at least one of indev or outdev
3888need to be specified.
3889
3890@item -object filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}]
3891
3892Dump the network traffic on netdev @var{dev} to the file specified by
3893@var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
3894The file format is libpcap, so it can be analyzed with tools such as tcpdump
3895or Wireshark.
3896
3897@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
3898@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
3899
3900Defines a secret to store a password, encryption key, or some other sensitive
3901data. The sensitive data can either be passed directly via the @var{data}
3902parameter, or indirectly via the @var{file} parameter. Using the @var{data}
3903parameter is insecure unless the sensitive data is encrypted.
3904
3905The sensitive data can be provided in raw format (the default), or base64.
3906When encoded as JSON, the raw format only supports valid UTF-8 characters,
3907so base64 is recommended for sending binary data. QEMU will convert from
3908which ever format is provided to the format it needs internally. eg, an
3909RBD password can be provided in raw format, even though it will be base64
3910encoded when passed onto the RBD sever.
3911
3912For added protection, it is possible to encrypt the data associated with
3913a secret using the AES-256-CBC cipher. Use of encryption is indicated
3914by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
3915parameter provides the ID of a previously defined secret that contains
3916the AES-256 decryption key. This key should be 32-bytes long and be
3917base64 encoded. The @var{iv} parameter provides the random initialization
3918vector used for encryption of this particular secret and should be a
3919base64 encrypted string of the 16-byte IV.
3920
3921The simplest (insecure) usage is to provide the secret inline
3922
3923@example
3924
3925 # $QEMU -object secret,id=sec0,data=letmein,format=raw
3926
3927@end example
3928
3929The simplest secure usage is to provide the secret via a file
3930
3931 # echo -n "letmein" > mypasswd.txt
3932 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
3933
3934For greater security, AES-256-CBC should be used. To illustrate usage,
3935consider the openssl command line tool which can encrypt the data. Note
3936that when encrypting, the plaintext must be padded to the cipher block
3937size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
3938
3939First a master key needs to be created in base64 encoding:
3940
3941@example
3942 # openssl rand -base64 32 > key.b64
3943 # KEY=$(base64 -d key.b64 | hexdump  -v -e '/1 "%02X"')
3944@end example
3945
3946Each secret to be encrypted needs to have a random initialization vector
3947generated. These do not need to be kept secret
3948
3949@example
3950 # openssl rand -base64 16 > iv.b64
3951 # IV=$(base64 -d iv.b64 | hexdump  -v -e '/1 "%02X"')
3952@end example
3953
3954The secret to be defined can now be encrypted, in this case we're
3955telling openssl to base64 encode the result, but it could be left
3956as raw bytes if desired.
3957
3958@example
3959 # SECRET=$(echo -n "letmein" |
3960            openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
3961@end example
3962
3963When launching QEMU, create a master secret pointing to @code{key.b64}
3964and specify that to be used to decrypt the user password. Pass the
3965contents of @code{iv.b64} to the second secret
3966
3967@example
3968 # $QEMU \
3969     -object secret,id=secmaster0,format=base64,file=key.b64 \
3970     -object secret,id=sec0,keyid=secmaster0,format=base64,\
3971         data=$SECRET,iv=$(<iv.b64)
3972@end example
3973
3974@end table
3975
3976ETEXI
3977
3978
3979HXCOMM This is the last statement. Insert new options before this line!
3980STEXI
3981@end table
3982ETEXI
3983