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\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 " iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n" 42 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n" 43 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 44 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 45 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 46 " nvdimm=on|off controls NVDIMM support (default=off)\n" 47 " enforce-config-section=on|off enforce configuration section migration (default=off)\n", 48 QEMU_ARCH_ALL) 49STEXI 50@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 51@findex -machine 52Select the emulated machine by @var{name}. Use @code{-machine help} to list 53available machines. Supported machine properties are: 54@table @option 55@item accel=@var{accels1}[:@var{accels2}[:...]] 56This is used to enable an accelerator. Depending on the target architecture, 57kvm, xen, or tcg can be available. By default, tcg is used. If there is more 58than one accelerator specified, the next one is used if the previous one fails 59to initialize. 60@item kernel_irqchip=on|off 61Controls in-kernel irqchip support for the chosen accelerator when available. 62@item gfx_passthru=on|off 63Enables IGD GFX passthrough support for the chosen machine when available. 64@item vmport=on|off|auto 65Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 66value based on accel. For accel=xen the default is off otherwise the default 67is on. 68@item kvm_shadow_mem=size 69Defines the size of the KVM shadow MMU. 70@item dump-guest-core=on|off 71Include guest memory in a core dump. The default is on. 72@item mem-merge=on|off 73Enables or disables memory merge support. This feature, when supported by 74the host, de-duplicates identical memory pages among VMs instances 75(enabled by default). 76@item iommu=on|off 77Enables or disables emulated Intel IOMMU (VT-d) support. The default is off. 78@item aes-key-wrap=on|off 79Enables or disables AES key wrapping support on s390-ccw hosts. This feature 80controls whether AES wrapping keys will be created to allow 81execution of AES cryptographic functions. The default is on. 82@item dea-key-wrap=on|off 83Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 84controls whether DEA wrapping keys will be created to allow 85execution of DEA cryptographic functions. The default is on. 86@item nvdimm=on|off 87Enables or disables NVDIMM support. The default is off. 88@end table 89ETEXI 90 91HXCOMM Deprecated by -machine 92DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 93 94DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 95 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 96STEXI 97@item -cpu @var{model} 98@findex -cpu 99Select CPU model (@code{-cpu help} for list and additional feature selection) 100ETEXI 101 102DEF("smp", HAS_ARG, QEMU_OPTION_smp, 103 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n" 104 " set the number of CPUs to 'n' [default=1]\n" 105 " maxcpus= maximum number of total cpus, including\n" 106 " offline CPUs for hotplug, etc\n" 107 " cores= number of CPU cores on one socket\n" 108 " threads= number of threads on one CPU core\n" 109 " sockets= number of discrete sockets in the system\n", 110 QEMU_ARCH_ALL) 111STEXI 112@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 113@findex -smp 114Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 115CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 116to 4. 117For the PC target, the number of @var{cores} per socket, the number 118of @var{threads} per cores and the total number of @var{sockets} can be 119specified. Missing values will be computed. If any on the three values is 120given, the total number of CPUs @var{n} can be omitted. @var{maxcpus} 121specifies the maximum number of hotpluggable CPUs. 122ETEXI 123 124DEF("numa", HAS_ARG, QEMU_OPTION_numa, 125 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n" 126 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL) 127STEXI 128@item -numa node[,mem=@var{size}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}] 129@itemx -numa node[,memdev=@var{id}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}] 130@findex -numa 131Simulate a multi node NUMA system. If @samp{mem}, @samp{memdev} 132and @samp{cpus} are omitted, resources are split equally. Also, note 133that the -@option{numa} option doesn't allocate any of the specified 134resources. That is, it just assigns existing resources to NUMA nodes. This 135means that one still has to use the @option{-m}, @option{-smp} options 136to allocate RAM and VCPUs respectively, and possibly @option{-object} 137to specify the memory backend for the @samp{memdev} suboption. 138 139@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one 140node uses @samp{memdev}, all of them have to use it. 141ETEXI 142 143DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 144 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 145 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 146STEXI 147@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 148@findex -add-fd 149 150Add a file descriptor to an fd set. Valid options are: 151 152@table @option 153@item fd=@var{fd} 154This option defines the file descriptor of which a duplicate is added to fd set. 155The file descriptor cannot be stdin, stdout, or stderr. 156@item set=@var{set} 157This option defines the ID of the fd set to add the file descriptor to. 158@item opaque=@var{opaque} 159This option defines a free-form string that can be used to describe @var{fd}. 160@end table 161 162You can open an image using pre-opened file descriptors from an fd set: 163@example 164qemu-system-i386 165-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 166-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 167-drive file=/dev/fdset/2,index=0,media=disk 168@end example 169ETEXI 170 171DEF("set", HAS_ARG, QEMU_OPTION_set, 172 "-set group.id.arg=value\n" 173 " set <arg> parameter for item <id> of type <group>\n" 174 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 175STEXI 176@item -set @var{group}.@var{id}.@var{arg}=@var{value} 177@findex -set 178Set parameter @var{arg} for item @var{id} of type @var{group}\n" 179ETEXI 180 181DEF("global", HAS_ARG, QEMU_OPTION_global, 182 "-global driver.property=value\n" 183 "-global driver=driver,property=property,value=value\n" 184 " set a global default for a driver property\n", 185 QEMU_ARCH_ALL) 186STEXI 187@item -global @var{driver}.@var{prop}=@var{value} 188@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 189@findex -global 190Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 191 192@example 193qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk 194@end example 195 196In particular, you can use this to set driver properties for devices which are 197created automatically by the machine model. To create a device which is not 198created automatically and set properties on it, use -@option{device}. 199 200-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 201driver=@var{driver},property=@var{prop},value=@var{value}. The 202longhand syntax works even when @var{driver} contains a dot. 203ETEXI 204 205DEF("boot", HAS_ARG, QEMU_OPTION_boot, 206 "-boot [order=drives][,once=drives][,menu=on|off]\n" 207 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 208 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 209 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 210 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 211 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 212 QEMU_ARCH_ALL) 213STEXI 214@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] 215@findex -boot 216Specify boot order @var{drives} as a string of drive letters. Valid 217drive letters depend on the target architecture. The x86 PC uses: a, b 218(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 219from network adapter 1-4), hard disk boot is the default. To apply a 220particular boot order only on the first startup, specify it via 221@option{once}. 222 223Interactive boot menus/prompts can be enabled via @option{menu=on} as far 224as firmware/BIOS supports them. The default is non-interactive boot. 225 226A splash picture could be passed to bios, enabling user to show it as logo, 227when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 228supports them. Currently Seabios for X86 system support it. 229limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 230format(true color). The resolution should be supported by the SVGA mode, so 231the recommended is 320x240, 640x480, 800x640. 232 233A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 234when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 235reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 236system support it. 237 238Do strict boot via @option{strict=on} as far as firmware/BIOS 239supports it. This only effects when boot priority is changed by 240bootindex options. The default is non-strict boot. 241 242@example 243# try to boot from network first, then from hard disk 244qemu-system-i386 -boot order=nc 245# boot from CD-ROM first, switch back to default order after reboot 246qemu-system-i386 -boot once=d 247# boot with a splash picture for 5 seconds. 248qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000 249@end example 250 251Note: The legacy format '-boot @var{drives}' is still supported but its 252use is discouraged as it may be removed from future versions. 253ETEXI 254 255DEF("m", HAS_ARG, QEMU_OPTION_m, 256 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n" 257 " configure guest RAM\n" 258 " size: initial amount of guest memory\n" 259 " slots: number of hotplug slots (default: none)\n" 260 " maxmem: maximum amount of guest memory (default: none)\n" 261 "NOTE: Some architectures might enforce a specific granularity\n", 262 QEMU_ARCH_ALL) 263STEXI 264@item -m [size=]@var{megs}[,slots=n,maxmem=size] 265@findex -m 266Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 267Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 268megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 269could be used to set amount of hotpluggable memory slots and maximum amount of 270memory. Note that @var{maxmem} must be aligned to the page size. 271 272For example, the following command-line sets the guest startup RAM size to 2731GB, creates 3 slots to hotplug additional memory and sets the maximum 274memory the guest can reach to 4GB: 275 276@example 277qemu-system-x86_64 -m 1G,slots=3,maxmem=4G 278@end example 279 280If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 281be enabled and the guest startup RAM will never increase. 282ETEXI 283 284DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 285 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 286STEXI 287@item -mem-path @var{path} 288@findex -mem-path 289Allocate guest RAM from a temporarily created file in @var{path}. 290ETEXI 291 292DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 293 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 294 QEMU_ARCH_ALL) 295STEXI 296@item -mem-prealloc 297@findex -mem-prealloc 298Preallocate memory when using -mem-path. 299ETEXI 300 301DEF("k", HAS_ARG, QEMU_OPTION_k, 302 "-k language use keyboard layout (for example 'fr' for French)\n", 303 QEMU_ARCH_ALL) 304STEXI 305@item -k @var{language} 306@findex -k 307Use keyboard layout @var{language} (for example @code{fr} for 308French). This option is only needed where it is not easy to get raw PC 309keycodes (e.g. on Macs, with some X11 servers or with a VNC 310display). You don't normally need to use it on PC/Linux or PC/Windows 311hosts. 312 313The available layouts are: 314@example 315ar de-ch es fo fr-ca hu ja mk no pt-br sv 316da en-gb et fr fr-ch is lt nl pl ru th 317de en-us fi fr-be hr it lv nl-be pt sl tr 318@end example 319 320The default is @code{en-us}. 321ETEXI 322 323 324DEF("audio-help", 0, QEMU_OPTION_audio_help, 325 "-audio-help print list of audio drivers and their options\n", 326 QEMU_ARCH_ALL) 327STEXI 328@item -audio-help 329@findex -audio-help 330Will show the audio subsystem help: list of drivers, tunable 331parameters. 332ETEXI 333 334DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 335 "-soundhw c1,... enable audio support\n" 336 " and only specified sound cards (comma separated list)\n" 337 " use '-soundhw help' to get the list of supported cards\n" 338 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 339STEXI 340@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 341@findex -soundhw 342Enable audio and selected sound hardware. Use 'help' to print all 343available sound hardware. 344 345@example 346qemu-system-i386 -soundhw sb16,adlib disk.img 347qemu-system-i386 -soundhw es1370 disk.img 348qemu-system-i386 -soundhw ac97 disk.img 349qemu-system-i386 -soundhw hda disk.img 350qemu-system-i386 -soundhw all disk.img 351qemu-system-i386 -soundhw help 352@end example 353 354Note that Linux's i810_audio OSS kernel (for AC97) module might 355require manually specifying clocking. 356 357@example 358modprobe i810_audio clocking=48000 359@end example 360ETEXI 361 362DEF("balloon", HAS_ARG, QEMU_OPTION_balloon, 363 "-balloon none disable balloon device\n" 364 "-balloon virtio[,addr=str]\n" 365 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL) 366STEXI 367@item -balloon none 368@findex -balloon 369Disable balloon device. 370@item -balloon virtio[,addr=@var{addr}] 371Enable virtio balloon device (default), optionally with PCI address 372@var{addr}. 373ETEXI 374 375DEF("device", HAS_ARG, QEMU_OPTION_device, 376 "-device driver[,prop[=value][,...]]\n" 377 " add device (based on driver)\n" 378 " prop=value,... sets driver properties\n" 379 " use '-device help' to print all possible drivers\n" 380 " use '-device driver,help' to print all possible properties\n", 381 QEMU_ARCH_ALL) 382STEXI 383@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 384@findex -device 385Add device @var{driver}. @var{prop}=@var{value} sets driver 386properties. Valid properties depend on the driver. To get help on 387possible drivers and properties, use @code{-device help} and 388@code{-device @var{driver},help}. 389 390Some drivers are: 391@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}] 392 393Add an IPMI BMC. This is a simulation of a hardware management 394interface processor that normally sits on a system. It provides 395a watchdog and the ability to reset and power control the system. 396You need to connect this to an IPMI interface to make it useful 397 398The IPMI slave address to use for the BMC. The default is 0x20. 399This address is the BMC's address on the I2C network of management 400controllers. If you don't know what this means, it is safe to ignore 401it. 402 403@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 404 405Add a connection to an external IPMI BMC simulator. Instead of 406locally emulating the BMC like the above item, instead connect 407to an external entity that provides the IPMI services. 408 409A connection is made to an external BMC simulator. If you do this, it 410is strongly recommended that you use the "reconnect=" chardev option 411to reconnect to the simulator if the connection is lost. Note that if 412this is not used carefully, it can be a security issue, as the 413interface has the ability to send resets, NMIs, and power off the VM. 414It's best if QEMU makes a connection to an external simulator running 415on a secure port on localhost, so neither the simulator nor QEMU is 416exposed to any outside network. 417 418See the "lanserv/README.vm" file in the OpenIPMI library for more 419details on the external interface. 420 421@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 422 423Add a KCS IPMI interafce on the ISA bus. This also adds a 424corresponding ACPI and SMBIOS entries, if appropriate. 425 426@table @option 427@item bmc=@var{id} 428The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 429@item ioport=@var{val} 430Define the I/O address of the interface. The default is 0xca0 for KCS. 431@item irq=@var{val} 432Define the interrupt to use. The default is 5. To disable interrupts, 433set this to 0. 434@end table 435 436@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 437 438Like the KCS interface, but defines a BT interface. The default port is 4390xe4 and the default interrupt is 5. 440 441ETEXI 442 443DEF("name", HAS_ARG, QEMU_OPTION_name, 444 "-name string1[,process=string2][,debug-threads=on|off]\n" 445 " set the name of the guest\n" 446 " string1 sets the window title and string2 the process name (on Linux)\n" 447 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n" 448 " NOTE: The thread names are for debugging and not a stable API.\n", 449 QEMU_ARCH_ALL) 450STEXI 451@item -name @var{name} 452@findex -name 453Sets the @var{name} of the guest. 454This name will be displayed in the SDL window caption. 455The @var{name} will also be used for the VNC server. 456Also optionally set the top visible process name in Linux. 457Naming of individual threads can also be enabled on Linux to aid debugging. 458ETEXI 459 460DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 461 "-uuid %08x-%04x-%04x-%04x-%012x\n" 462 " specify machine UUID\n", QEMU_ARCH_ALL) 463STEXI 464@item -uuid @var{uuid} 465@findex -uuid 466Set system UUID. 467ETEXI 468 469STEXI 470@end table 471ETEXI 472DEFHEADING() 473 474DEFHEADING(Block device options:) 475STEXI 476@table @option 477ETEXI 478 479DEF("fda", HAS_ARG, QEMU_OPTION_fda, 480 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 481DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 482STEXI 483@item -fda @var{file} 484@itemx -fdb @var{file} 485@findex -fda 486@findex -fdb 487Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 488ETEXI 489 490DEF("hda", HAS_ARG, QEMU_OPTION_hda, 491 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 492DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 493DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 494 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 495DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 496STEXI 497@item -hda @var{file} 498@itemx -hdb @var{file} 499@itemx -hdc @var{file} 500@itemx -hdd @var{file} 501@findex -hda 502@findex -hdb 503@findex -hdc 504@findex -hdd 505Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 506ETEXI 507 508DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 509 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 510 QEMU_ARCH_ALL) 511STEXI 512@item -cdrom @var{file} 513@findex -cdrom 514Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 515@option{-cdrom} at the same time). You can use the host CD-ROM by 516using @file{/dev/cdrom} as filename (@pxref{host_drives}). 517ETEXI 518 519DEF("drive", HAS_ARG, QEMU_OPTION_drive, 520 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 521 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n" 522 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 523 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n" 524 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 525 " [,readonly=on|off][,copy-on-read=on|off]\n" 526 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 527 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 528 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 529 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 530 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 531 " [[,iops_size=is]]\n" 532 " [[,group=g]]\n" 533 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 534STEXI 535@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 536@findex -drive 537 538Define a new drive. Valid options are: 539 540@table @option 541@item file=@var{file} 542This option defines which disk image (@pxref{disk_images}) to use with 543this drive. If the filename contains comma, you must double it 544(for instance, "file=my,,file" to use file "my,file"). 545 546Special files such as iSCSI devices can be specified using protocol 547specific URLs. See the section for "Device URL Syntax" for more information. 548@item if=@var{interface} 549This option defines on which type on interface the drive is connected. 550Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio. 551@item bus=@var{bus},unit=@var{unit} 552These options define where is connected the drive by defining the bus number and 553the unit id. 554@item index=@var{index} 555This option defines where is connected the drive by using an index in the list 556of available connectors of a given interface type. 557@item media=@var{media} 558This option defines the type of the media: disk or cdrom. 559@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}] 560These options have the same definition as they have in @option{-hdachs}. 561@item snapshot=@var{snapshot} 562@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 563(see @option{-snapshot}). 564@item cache=@var{cache} 565@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data. 566@item aio=@var{aio} 567@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 568@item discard=@var{discard} 569@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. 570@item format=@var{format} 571Specify which disk @var{format} will be used rather than detecting 572the format. Can be used to specifiy format=raw to avoid interpreting 573an untrusted format header. 574@item serial=@var{serial} 575This option specifies the serial number to assign to the device. 576@item addr=@var{addr} 577Specify the controller's PCI address (if=virtio only). 578@item werror=@var{action},rerror=@var{action} 579Specify which @var{action} to take on write and read errors. Valid actions are: 580"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 581"report" (report the error to the guest), "enospc" (pause QEMU only if the 582host disk is full; report the error to the guest otherwise). 583The default setting is @option{werror=enospc} and @option{rerror=report}. 584@item readonly 585Open drive @option{file} as read-only. Guest write attempts will fail. 586@item copy-on-read=@var{copy-on-read} 587@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 588file sectors into the image file. 589@item detect-zeroes=@var{detect-zeroes} 590@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 591conversion of plain zero writes by the OS to driver specific optimized 592zero write commands. You may even choose "unmap" if @var{discard} is set 593to "unmap" to allow a zero write to be converted to an UNMAP operation. 594@end table 595 596By default, the @option{cache=writeback} mode is used. It will report data 597writes as completed as soon as the data is present in the host page cache. 598This is safe as long as your guest OS makes sure to correctly flush disk caches 599where needed. If your guest OS does not handle volatile disk write caches 600correctly and your host crashes or loses power, then the guest may experience 601data corruption. 602 603For such guests, you should consider using @option{cache=writethrough}. This 604means that the host page cache will be used to read and write data, but write 605notification will be sent to the guest only after QEMU has made sure to flush 606each write to the disk. Be aware that this has a major impact on performance. 607 608The host page cache can be avoided entirely with @option{cache=none}. This will 609attempt to do disk IO directly to the guest's memory. QEMU may still perform 610an internal copy of the data. Note that this is considered a writeback mode and 611the guest OS must handle the disk write cache correctly in order to avoid data 612corruption on host crashes. 613 614The host page cache can be avoided while only sending write notifications to 615the guest when the data has been flushed to the disk using 616@option{cache=directsync}. 617 618In case you don't care about data integrity over host failures, use 619@option{cache=unsafe}. This option tells QEMU that it never needs to write any 620data to the disk but can instead keep things in cache. If anything goes wrong, 621like your host losing power, the disk storage getting disconnected accidentally, 622etc. your image will most probably be rendered unusable. When using 623the @option{-snapshot} option, unsafe caching is always used. 624 625Copy-on-read avoids accessing the same backing file sectors repeatedly and is 626useful when the backing file is over a slow network. By default copy-on-read 627is off. 628 629Instead of @option{-cdrom} you can use: 630@example 631qemu-system-i386 -drive file=file,index=2,media=cdrom 632@end example 633 634Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 635use: 636@example 637qemu-system-i386 -drive file=file,index=0,media=disk 638qemu-system-i386 -drive file=file,index=1,media=disk 639qemu-system-i386 -drive file=file,index=2,media=disk 640qemu-system-i386 -drive file=file,index=3,media=disk 641@end example 642 643You can open an image using pre-opened file descriptors from an fd set: 644@example 645qemu-system-i386 646-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 647-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 648-drive file=/dev/fdset/2,index=0,media=disk 649@end example 650 651You can connect a CDROM to the slave of ide0: 652@example 653qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom 654@end example 655 656If you don't specify the "file=" argument, you define an empty drive: 657@example 658qemu-system-i386 -drive if=ide,index=1,media=cdrom 659@end example 660 661You can connect a SCSI disk with unit ID 6 on the bus #0: 662@example 663qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6 664@end example 665 666Instead of @option{-fda}, @option{-fdb}, you can use: 667@example 668qemu-system-i386 -drive file=file,index=0,if=floppy 669qemu-system-i386 -drive file=file,index=1,if=floppy 670@end example 671 672By default, @var{interface} is "ide" and @var{index} is automatically 673incremented: 674@example 675qemu-system-i386 -drive file=a -drive file=b" 676@end example 677is interpreted like: 678@example 679qemu-system-i386 -hda a -hdb b 680@end example 681ETEXI 682 683DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 684 "-mtdblock file use 'file' as on-board Flash memory image\n", 685 QEMU_ARCH_ALL) 686STEXI 687@item -mtdblock @var{file} 688@findex -mtdblock 689Use @var{file} as on-board Flash memory image. 690ETEXI 691 692DEF("sd", HAS_ARG, QEMU_OPTION_sd, 693 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 694STEXI 695@item -sd @var{file} 696@findex -sd 697Use @var{file} as SecureDigital card image. 698ETEXI 699 700DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 701 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 702STEXI 703@item -pflash @var{file} 704@findex -pflash 705Use @var{file} as a parallel flash image. 706ETEXI 707 708DEF("snapshot", 0, QEMU_OPTION_snapshot, 709 "-snapshot write to temporary files instead of disk image files\n", 710 QEMU_ARCH_ALL) 711STEXI 712@item -snapshot 713@findex -snapshot 714Write to temporary files instead of disk image files. In this case, 715the raw disk image you use is not written back. You can however force 716the write back by pressing @key{C-a s} (@pxref{disk_images}). 717ETEXI 718 719DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \ 720 "-hdachs c,h,s[,t]\n" \ 721 " force hard disk 0 physical geometry and the optional BIOS\n" \ 722 " translation (t=none or lba) (usually QEMU can guess them)\n", 723 QEMU_ARCH_ALL) 724STEXI 725@item -hdachs @var{c},@var{h},@var{s},[,@var{t}] 726@findex -hdachs 727Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <= 728@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS 729translation mode (@var{t}=none, lba or auto). Usually QEMU can guess 730all those parameters. This option is useful for old MS-DOS disk 731images. 732ETEXI 733 734DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 735 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n" 736 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n", 737 QEMU_ARCH_ALL) 738 739STEXI 740 741@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}] 742@findex -fsdev 743Define a new file system device. Valid options are: 744@table @option 745@item @var{fsdriver} 746This option specifies the fs driver backend to use. 747Currently "local", "handle" and "proxy" file system drivers are supported. 748@item id=@var{id} 749Specifies identifier for this device 750@item path=@var{path} 751Specifies the export path for the file system device. Files under 752this path will be available to the 9p client on the guest. 753@item security_model=@var{security_model} 754Specifies the security model to be used for this export path. 755Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 756In "passthrough" security model, files are stored using the same 757credentials as they are created on the guest. This requires QEMU 758to run as root. In "mapped-xattr" security model, some of the file 759attributes like uid, gid, mode bits and link target are stored as 760file attributes. For "mapped-file" these attributes are stored in the 761hidden .virtfs_metadata directory. Directories exported by this security model cannot 762interact with other unix tools. "none" security model is same as 763passthrough except the sever won't report failures if it fails to 764set file attributes like ownership. Security model is mandatory 765only for local fsdriver. Other fsdrivers (like handle, proxy) don't take 766security model as a parameter. 767@item writeout=@var{writeout} 768This is an optional argument. The only supported value is "immediate". 769This means that host page cache will be used to read and write data but 770write notification will be sent to the guest only when the data has been 771reported as written by the storage subsystem. 772@item readonly 773Enables exporting 9p share as a readonly mount for guests. By default 774read-write access is given. 775@item socket=@var{socket} 776Enables proxy filesystem driver to use passed socket file for communicating 777with virtfs-proxy-helper 778@item sock_fd=@var{sock_fd} 779Enables proxy filesystem driver to use passed socket descriptor for 780communicating with virtfs-proxy-helper. Usually a helper like libvirt 781will create socketpair and pass one of the fds as sock_fd 782@end table 783 784-fsdev option is used along with -device driver "virtio-9p-pci". 785@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag} 786Options for virtio-9p-pci driver are: 787@table @option 788@item fsdev=@var{id} 789Specifies the id value specified along with -fsdev option 790@item mount_tag=@var{mount_tag} 791Specifies the tag name to be used by the guest to mount this export point 792@end table 793 794ETEXI 795 796DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 797 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n" 798 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n", 799 QEMU_ARCH_ALL) 800 801STEXI 802 803@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}] 804@findex -virtfs 805 806The general form of a Virtual File system pass-through options are: 807@table @option 808@item @var{fsdriver} 809This option specifies the fs driver backend to use. 810Currently "local", "handle" and "proxy" file system drivers are supported. 811@item id=@var{id} 812Specifies identifier for this device 813@item path=@var{path} 814Specifies the export path for the file system device. Files under 815this path will be available to the 9p client on the guest. 816@item security_model=@var{security_model} 817Specifies the security model to be used for this export path. 818Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 819In "passthrough" security model, files are stored using the same 820credentials as they are created on the guest. This requires QEMU 821to run as root. In "mapped-xattr" security model, some of the file 822attributes like uid, gid, mode bits and link target are stored as 823file attributes. For "mapped-file" these attributes are stored in the 824hidden .virtfs_metadata directory. Directories exported by this security model cannot 825interact with other unix tools. "none" security model is same as 826passthrough except the sever won't report failures if it fails to 827set file attributes like ownership. Security model is mandatory only 828for local fsdriver. Other fsdrivers (like handle, proxy) don't take security 829model as a parameter. 830@item writeout=@var{writeout} 831This is an optional argument. The only supported value is "immediate". 832This means that host page cache will be used to read and write data but 833write notification will be sent to the guest only when the data has been 834reported as written by the storage subsystem. 835@item readonly 836Enables exporting 9p share as a readonly mount for guests. By default 837read-write access is given. 838@item socket=@var{socket} 839Enables proxy filesystem driver to use passed socket file for 840communicating with virtfs-proxy-helper. Usually a helper like libvirt 841will create socketpair and pass one of the fds as sock_fd 842@item sock_fd 843Enables proxy filesystem driver to use passed 'sock_fd' as the socket 844descriptor for interfacing with virtfs-proxy-helper 845@end table 846ETEXI 847 848DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 849 "-virtfs_synth Create synthetic file system image\n", 850 QEMU_ARCH_ALL) 851STEXI 852@item -virtfs_synth 853@findex -virtfs_synth 854Create synthetic file system image 855ETEXI 856 857STEXI 858@end table 859ETEXI 860DEFHEADING() 861 862DEFHEADING(USB options:) 863STEXI 864@table @option 865ETEXI 866 867DEF("usb", 0, QEMU_OPTION_usb, 868 "-usb enable the USB driver (will be the default soon)\n", 869 QEMU_ARCH_ALL) 870STEXI 871@item -usb 872@findex -usb 873Enable the USB driver (will be the default soon) 874ETEXI 875 876DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 877 "-usbdevice name add the host or guest USB device 'name'\n", 878 QEMU_ARCH_ALL) 879STEXI 880 881@item -usbdevice @var{devname} 882@findex -usbdevice 883Add the USB device @var{devname}. @xref{usb_devices}. 884 885@table @option 886 887@item mouse 888Virtual Mouse. This will override the PS/2 mouse emulation when activated. 889 890@item tablet 891Pointer device that uses absolute coordinates (like a touchscreen). This 892means QEMU is able to report the mouse position without having to grab the 893mouse. Also overrides the PS/2 mouse emulation when activated. 894 895@item disk:[format=@var{format}]:@var{file} 896Mass storage device based on file. The optional @var{format} argument 897will be used rather than detecting the format. Can be used to specifiy 898@code{format=raw} to avoid interpreting an untrusted format header. 899 900@item host:@var{bus}.@var{addr} 901Pass through the host device identified by @var{bus}.@var{addr} (Linux only). 902 903@item host:@var{vendor_id}:@var{product_id} 904Pass through the host device identified by @var{vendor_id}:@var{product_id} 905(Linux only). 906 907@item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev} 908Serial converter to host character device @var{dev}, see @code{-serial} for the 909available devices. 910 911@item braille 912Braille device. This will use BrlAPI to display the braille output on a real 913or fake device. 914 915@item net:@var{options} 916Network adapter that supports CDC ethernet and RNDIS protocols. 917 918@end table 919ETEXI 920 921STEXI 922@end table 923ETEXI 924DEFHEADING() 925 926DEFHEADING(Display options:) 927STEXI 928@table @option 929ETEXI 930 931DEF("display", HAS_ARG, QEMU_OPTION_display, 932 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 933 " [,window_close=on|off]|curses|none|\n" 934 " gtk[,grab_on_hover=on|off]|\n" 935 " vnc=<display>[,<optargs>]\n" 936 " select display type\n", QEMU_ARCH_ALL) 937STEXI 938@item -display @var{type} 939@findex -display 940Select type of display to use. This option is a replacement for the 941old style -sdl/-curses/... options. Valid values for @var{type} are 942@table @option 943@item sdl 944Display video output via SDL (usually in a separate graphics 945window; see the SDL documentation for other possibilities). 946@item curses 947Display video output via curses. For graphics device models which 948support a text mode, QEMU can display this output using a 949curses/ncurses interface. Nothing is displayed when the graphics 950device is in graphical mode or if the graphics device does not support 951a text mode. Generally only the VGA device models support text mode. 952@item none 953Do not display video output. The guest will still see an emulated 954graphics card, but its output will not be displayed to the QEMU 955user. This option differs from the -nographic option in that it 956only affects what is done with video output; -nographic also changes 957the destination of the serial and parallel port data. 958@item gtk 959Display video output in a GTK window. This interface provides drop-down 960menus and other UI elements to configure and control the VM during 961runtime. 962@item vnc 963Start a VNC server on display <arg> 964@end table 965ETEXI 966 967DEF("nographic", 0, QEMU_OPTION_nographic, 968 "-nographic disable graphical output and redirect serial I/Os to console\n", 969 QEMU_ARCH_ALL) 970STEXI 971@item -nographic 972@findex -nographic 973Normally, QEMU uses SDL to display the VGA output. With this option, 974you can totally disable graphical output so that QEMU is a simple 975command line application. The emulated serial port is redirected on 976the console and muxed with the monitor (unless redirected elsewhere 977explicitly). Therefore, you can still use QEMU to debug a Linux kernel 978with a serial console. Use @key{C-a h} for help on switching between 979the console and monitor. 980ETEXI 981 982DEF("curses", 0, QEMU_OPTION_curses, 983 "-curses use a curses/ncurses interface instead of SDL\n", 984 QEMU_ARCH_ALL) 985STEXI 986@item -curses 987@findex -curses 988Normally, QEMU uses SDL to display the VGA output. With this option, 989QEMU can display the VGA output when in text mode using a 990curses/ncurses interface. Nothing is displayed in graphical mode. 991ETEXI 992 993DEF("no-frame", 0, QEMU_OPTION_no_frame, 994 "-no-frame open SDL window without a frame and window decorations\n", 995 QEMU_ARCH_ALL) 996STEXI 997@item -no-frame 998@findex -no-frame 999Do not use decorations for SDL windows and start them using the whole 1000available screen space. This makes the using QEMU in a dedicated desktop 1001workspace more convenient. 1002ETEXI 1003 1004DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1005 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1006 QEMU_ARCH_ALL) 1007STEXI 1008@item -alt-grab 1009@findex -alt-grab 1010Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1011affects the special keys (for fullscreen, monitor-mode switching, etc). 1012ETEXI 1013 1014DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1015 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1016 QEMU_ARCH_ALL) 1017STEXI 1018@item -ctrl-grab 1019@findex -ctrl-grab 1020Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1021affects the special keys (for fullscreen, monitor-mode switching, etc). 1022ETEXI 1023 1024DEF("no-quit", 0, QEMU_OPTION_no_quit, 1025 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1026STEXI 1027@item -no-quit 1028@findex -no-quit 1029Disable SDL window close capability. 1030ETEXI 1031 1032DEF("sdl", 0, QEMU_OPTION_sdl, 1033 "-sdl enable SDL\n", QEMU_ARCH_ALL) 1034STEXI 1035@item -sdl 1036@findex -sdl 1037Enable SDL. 1038ETEXI 1039 1040DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1041 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1042 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1043 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1044 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1045 " [,tls-ciphers=<list>]\n" 1046 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1047 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1048 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1049 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1050 " [,jpeg-wan-compression=[auto|never|always]]\n" 1051 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1052 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1053 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1054 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1055 " [,gl=[on|off]]\n" 1056 " enable spice\n" 1057 " at least one of {port, tls-port} is mandatory\n", 1058 QEMU_ARCH_ALL) 1059STEXI 1060@item -spice @var{option}[,@var{option}[,...]] 1061@findex -spice 1062Enable the spice remote desktop protocol. Valid options are 1063 1064@table @option 1065 1066@item port=<nr> 1067Set the TCP port spice is listening on for plaintext channels. 1068 1069@item addr=<addr> 1070Set the IP address spice is listening on. Default is any address. 1071 1072@item ipv4 1073@itemx ipv6 1074@itemx unix 1075Force using the specified IP version. 1076 1077@item password=<secret> 1078Set the password you need to authenticate. 1079 1080@item sasl 1081Require that the client use SASL to authenticate with the spice. 1082The exact choice of authentication method used is controlled from the 1083system / user's SASL configuration file for the 'qemu' service. This 1084is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1085unprivileged user, an environment variable SASL_CONF_PATH can be used 1086to make it search alternate locations for the service config. 1087While some SASL auth methods can also provide data encryption (eg GSSAPI), 1088it is recommended that SASL always be combined with the 'tls' and 1089'x509' settings to enable use of SSL and server certificates. This 1090ensures a data encryption preventing compromise of authentication 1091credentials. 1092 1093@item disable-ticketing 1094Allow client connects without authentication. 1095 1096@item disable-copy-paste 1097Disable copy paste between the client and the guest. 1098 1099@item disable-agent-file-xfer 1100Disable spice-vdagent based file-xfer between the client and the guest. 1101 1102@item tls-port=<nr> 1103Set the TCP port spice is listening on for encrypted channels. 1104 1105@item x509-dir=<dir> 1106Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1107 1108@item x509-key-file=<file> 1109@itemx x509-key-password=<file> 1110@itemx x509-cert-file=<file> 1111@itemx x509-cacert-file=<file> 1112@itemx x509-dh-key-file=<file> 1113The x509 file names can also be configured individually. 1114 1115@item tls-ciphers=<list> 1116Specify which ciphers to use. 1117 1118@item tls-channel=[main|display|cursor|inputs|record|playback] 1119@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1120Force specific channel to be used with or without TLS encryption. The 1121options can be specified multiple times to configure multiple 1122channels. The special name "default" can be used to set the default 1123mode. For channels which are not explicitly forced into one mode the 1124spice client is allowed to pick tls/plaintext as he pleases. 1125 1126@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1127Configure image compression (lossless). 1128Default is auto_glz. 1129 1130@item jpeg-wan-compression=[auto|never|always] 1131@itemx zlib-glz-wan-compression=[auto|never|always] 1132Configure wan image compression (lossy for slow links). 1133Default is auto. 1134 1135@item streaming-video=[off|all|filter] 1136Configure video stream detection. Default is filter. 1137 1138@item agent-mouse=[on|off] 1139Enable/disable passing mouse events via vdagent. Default is on. 1140 1141@item playback-compression=[on|off] 1142Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1143 1144@item seamless-migration=[on|off] 1145Enable/disable spice seamless migration. Default is off. 1146 1147@item gl=[on|off] 1148Enable/disable OpenGL context. Default is off. 1149 1150@end table 1151ETEXI 1152 1153DEF("portrait", 0, QEMU_OPTION_portrait, 1154 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1155 QEMU_ARCH_ALL) 1156STEXI 1157@item -portrait 1158@findex -portrait 1159Rotate graphical output 90 deg left (only PXA LCD). 1160ETEXI 1161 1162DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1163 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1164 QEMU_ARCH_ALL) 1165STEXI 1166@item -rotate @var{deg} 1167@findex -rotate 1168Rotate graphical output some deg left (only PXA LCD). 1169ETEXI 1170 1171DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1172 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1173 " select video card type\n", QEMU_ARCH_ALL) 1174STEXI 1175@item -vga @var{type} 1176@findex -vga 1177Select type of VGA card to emulate. Valid values for @var{type} are 1178@table @option 1179@item cirrus 1180Cirrus Logic GD5446 Video card. All Windows versions starting from 1181Windows 95 should recognize and use this graphic card. For optimal 1182performances, use 16 bit color depth in the guest and the host OS. 1183(This one is the default) 1184@item std 1185Standard VGA card with Bochs VBE extensions. If your guest OS 1186supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1187to use high resolution modes (>= 1280x1024x16) then you should use 1188this option. 1189@item vmware 1190VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1191recent XFree86/XOrg server or Windows guest with a driver for this 1192card. 1193@item qxl 1194QXL paravirtual graphic card. It is VGA compatible (including VESA 11952.0 VBE support). Works best with qxl guest drivers installed though. 1196Recommended choice when using the spice protocol. 1197@item tcx 1198(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1199sun4m machines and offers both 8-bit and 24-bit colour depths at a 1200fixed resolution of 1024x768. 1201@item cg3 1202(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1203for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1204resolutions aimed at people wishing to run older Solaris versions. 1205@item virtio 1206Virtio VGA card. 1207@item none 1208Disable VGA card. 1209@end table 1210ETEXI 1211 1212DEF("full-screen", 0, QEMU_OPTION_full_screen, 1213 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1214STEXI 1215@item -full-screen 1216@findex -full-screen 1217Start in full screen. 1218ETEXI 1219 1220DEF("g", 1, QEMU_OPTION_g , 1221 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1222 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1223STEXI 1224@item -g @var{width}x@var{height}[x@var{depth}] 1225@findex -g 1226Set the initial graphical resolution and depth (PPC, SPARC only). 1227ETEXI 1228 1229DEF("input-linux", 1, QEMU_OPTION_input_linux, 1230 "-input-linux <evdev>\n" 1231 " Use input device.\n", QEMU_ARCH_ALL) 1232STEXI 1233@item -input-linux @var{dev} 1234@findex -input-linux 1235Use input device. 1236ETEXI 1237 1238DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1239 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL) 1240STEXI 1241@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1242@findex -vnc 1243Normally, QEMU uses SDL to display the VGA output. With this option, 1244you can have QEMU listen on VNC display @var{display} and redirect the VGA 1245display over the VNC session. It is very useful to enable the usb 1246tablet device when using this option (option @option{-usbdevice 1247tablet}). When using the VNC display, you must use the @option{-k} 1248parameter to set the keyboard layout if you are not using en-us. Valid 1249syntax for the @var{display} is 1250 1251@table @option 1252 1253@item @var{host}:@var{d} 1254 1255TCP connections will only be allowed from @var{host} on display @var{d}. 1256By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1257be omitted in which case the server will accept connections from any host. 1258 1259@item unix:@var{path} 1260 1261Connections will be allowed over UNIX domain sockets where @var{path} is the 1262location of a unix socket to listen for connections on. 1263 1264@item none 1265 1266VNC is initialized but not started. The monitor @code{change} command 1267can be used to later start the VNC server. 1268 1269@end table 1270 1271Following the @var{display} value there may be one or more @var{option} flags 1272separated by commas. Valid options are 1273 1274@table @option 1275 1276@item reverse 1277 1278Connect to a listening VNC client via a ``reverse'' connection. The 1279client is specified by the @var{display}. For reverse network 1280connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1281is a TCP port number, not a display number. 1282 1283@item websocket 1284 1285Opens an additional TCP listening port dedicated to VNC Websocket connections. 1286By definition the Websocket port is 5700+@var{display}. If @var{host} is 1287specified connections will only be allowed from this host. 1288As an alternative the Websocket port could be specified by using 1289@code{websocket}=@var{port}. 1290If no TLS credentials are provided, the websocket connection runs in 1291unencrypted mode. If TLS credentials are provided, the websocket connection 1292requires encrypted client connections. 1293 1294@item password 1295 1296Require that password based authentication is used for client connections. 1297 1298The password must be set separately using the @code{set_password} command in 1299the @ref{pcsys_monitor}. The syntax to change your password is: 1300@code{set_password <protocol> <password>} where <protocol> could be either 1301"vnc" or "spice". 1302 1303If you would like to change <protocol> password expiration, you should use 1304@code{expire_password <protocol> <expiration-time>} where expiration time could 1305be one of the following options: now, never, +seconds or UNIX time of 1306expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1307to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1308date and time). 1309 1310You can also use keywords "now" or "never" for the expiration time to 1311allow <protocol> password to expire immediately or never expire. 1312 1313@item tls-creds=@var{ID} 1314 1315Provides the ID of a set of TLS credentials to use to secure the 1316VNC server. They will apply to both the normal VNC server socket 1317and the websocket socket (if enabled). Setting TLS credentials 1318will cause the VNC server socket to enable the VeNCrypt auth 1319mechanism. The credentials should have been previously created 1320using the @option{-object tls-creds} argument. 1321 1322The @option{tls-creds} parameter obsoletes the @option{tls}, 1323@option{x509}, and @option{x509verify} options, and as such 1324it is not permitted to set both new and old type options at 1325the same time. 1326 1327@item tls 1328 1329Require that client use TLS when communicating with the VNC server. This 1330uses anonymous TLS credentials so is susceptible to a man-in-the-middle 1331attack. It is recommended that this option be combined with either the 1332@option{x509} or @option{x509verify} options. 1333 1334This option is now deprecated in favor of using the @option{tls-creds} 1335argument. 1336 1337@item x509=@var{/path/to/certificate/dir} 1338 1339Valid if @option{tls} is specified. Require that x509 credentials are used 1340for negotiating the TLS session. The server will send its x509 certificate 1341to the client. It is recommended that a password be set on the VNC server 1342to provide authentication of the client when this is used. The path following 1343this option specifies where the x509 certificates are to be loaded from. 1344See the @ref{vnc_security} section for details on generating certificates. 1345 1346This option is now deprecated in favour of using the @option{tls-creds} 1347argument. 1348 1349@item x509verify=@var{/path/to/certificate/dir} 1350 1351Valid if @option{tls} is specified. Require that x509 credentials are used 1352for negotiating the TLS session. The server will send its x509 certificate 1353to the client, and request that the client send its own x509 certificate. 1354The server will validate the client's certificate against the CA certificate, 1355and reject clients when validation fails. If the certificate authority is 1356trusted, this is a sufficient authentication mechanism. You may still wish 1357to set a password on the VNC server as a second authentication layer. The 1358path following this option specifies where the x509 certificates are to 1359be loaded from. See the @ref{vnc_security} section for details on generating 1360certificates. 1361 1362This option is now deprecated in favour of using the @option{tls-creds} 1363argument. 1364 1365@item sasl 1366 1367Require that the client use SASL to authenticate with the VNC server. 1368The exact choice of authentication method used is controlled from the 1369system / user's SASL configuration file for the 'qemu' service. This 1370is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1371unprivileged user, an environment variable SASL_CONF_PATH can be used 1372to make it search alternate locations for the service config. 1373While some SASL auth methods can also provide data encryption (eg GSSAPI), 1374it is recommended that SASL always be combined with the 'tls' and 1375'x509' settings to enable use of SSL and server certificates. This 1376ensures a data encryption preventing compromise of authentication 1377credentials. See the @ref{vnc_security} section for details on using 1378SASL authentication. 1379 1380@item acl 1381 1382Turn on access control lists for checking of the x509 client certificate 1383and SASL party. For x509 certs, the ACL check is made against the 1384certificate's distinguished name. This is something that looks like 1385@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is 1386made against the username, which depending on the SASL plugin, may 1387include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}. 1388When the @option{acl} flag is set, the initial access list will be 1389empty, with a @code{deny} policy. Thus no one will be allowed to 1390use the VNC server until the ACLs have been loaded. This can be 1391achieved using the @code{acl} monitor command. 1392 1393@item lossy 1394 1395Enable lossy compression methods (gradient, JPEG, ...). If this 1396option is set, VNC client may receive lossy framebuffer updates 1397depending on its encoding settings. Enabling this option can save 1398a lot of bandwidth at the expense of quality. 1399 1400@item non-adaptive 1401 1402Disable adaptive encodings. Adaptive encodings are enabled by default. 1403An adaptive encoding will try to detect frequently updated screen regions, 1404and send updates in these regions using a lossy encoding (like JPEG). 1405This can be really helpful to save bandwidth when playing videos. Disabling 1406adaptive encodings restores the original static behavior of encodings 1407like Tight. 1408 1409@item share=[allow-exclusive|force-shared|ignore] 1410 1411Set display sharing policy. 'allow-exclusive' allows clients to ask 1412for exclusive access. As suggested by the rfb spec this is 1413implemented by dropping other connections. Connecting multiple 1414clients in parallel requires all clients asking for a shared session 1415(vncviewer: -shared switch). This is the default. 'force-shared' 1416disables exclusive client access. Useful for shared desktop sessions, 1417where you don't want someone forgetting specify -shared disconnect 1418everybody else. 'ignore' completely ignores the shared flag and 1419allows everybody connect unconditionally. Doesn't conform to the rfb 1420spec but is traditional QEMU behavior. 1421 1422@end table 1423ETEXI 1424 1425STEXI 1426@end table 1427ETEXI 1428ARCHHEADING(, QEMU_ARCH_I386) 1429 1430ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 1431STEXI 1432@table @option 1433ETEXI 1434 1435DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1436 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1437 QEMU_ARCH_I386) 1438STEXI 1439@item -win2k-hack 1440@findex -win2k-hack 1441Use it when installing Windows 2000 to avoid a disk full bug. After 1442Windows 2000 is installed, you no longer need this option (this option 1443slows down the IDE transfers). 1444ETEXI 1445 1446HXCOMM Deprecated by -rtc 1447DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386) 1448 1449DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 1450 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 1451 QEMU_ARCH_I386) 1452STEXI 1453@item -no-fd-bootchk 1454@findex -no-fd-bootchk 1455Disable boot signature checking for floppy disks in BIOS. May 1456be needed to boot from old floppy disks. 1457ETEXI 1458 1459DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 1460 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1461STEXI 1462@item -no-acpi 1463@findex -no-acpi 1464Disable ACPI (Advanced Configuration and Power Interface) support. Use 1465it if your guest OS complains about ACPI problems (PC target machine 1466only). 1467ETEXI 1468 1469DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 1470 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 1471STEXI 1472@item -no-hpet 1473@findex -no-hpet 1474Disable HPET support. 1475ETEXI 1476 1477DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 1478 "-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" 1479 " ACPI table description\n", QEMU_ARCH_I386) 1480STEXI 1481@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}]...] 1482@findex -acpitable 1483Add ACPI table with specified header fields and context from specified files. 1484For file=, take whole ACPI table from the specified files, including all 1485ACPI headers (possible overridden by other options). 1486For data=, only data 1487portion of the table is used, all header information is specified in the 1488command line. 1489If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 1490fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 1491to ensure the field matches required by the Microsoft SLIC spec and the ACPI 1492spec. 1493ETEXI 1494 1495DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 1496 "-smbios file=binary\n" 1497 " load SMBIOS entry from binary file\n" 1498 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 1499 " [,uefi=on|off]\n" 1500 " specify SMBIOS type 0 fields\n" 1501 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1502 " [,uuid=uuid][,sku=str][,family=str]\n" 1503 " specify SMBIOS type 1 fields\n" 1504 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1505 " [,asset=str][,location=str]\n" 1506 " specify SMBIOS type 2 fields\n" 1507 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 1508 " [,sku=str]\n" 1509 " specify SMBIOS type 3 fields\n" 1510 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 1511 " [,asset=str][,part=str]\n" 1512 " specify SMBIOS type 4 fields\n" 1513 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 1514 " [,asset=str][,part=str][,speed=%d]\n" 1515 " specify SMBIOS type 17 fields\n", 1516 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1517STEXI 1518@item -smbios file=@var{binary} 1519@findex -smbios 1520Load SMBIOS entry from binary file. 1521 1522@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 1523Specify SMBIOS type 0 fields 1524 1525@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}] 1526Specify SMBIOS type 1 fields 1527 1528@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}] 1529Specify SMBIOS type 2 fields 1530 1531@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 1532Specify SMBIOS type 3 fields 1533 1534@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 1535Specify SMBIOS type 4 fields 1536 1537@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}] 1538Specify SMBIOS type 17 fields 1539ETEXI 1540 1541STEXI 1542@end table 1543ETEXI 1544DEFHEADING() 1545 1546DEFHEADING(Network options:) 1547STEXI 1548@table @option 1549ETEXI 1550 1551HXCOMM Legacy slirp options (now moved to -net user): 1552#ifdef CONFIG_SLIRP 1553DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL) 1554DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL) 1555DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL) 1556#ifndef _WIN32 1557DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL) 1558#endif 1559#endif 1560 1561DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 1562#ifdef CONFIG_SLIRP 1563 "-netdev user,id=str[,net=addr[/mask]][,host=addr][,ip6-net=addr[/int]]\n" 1564 " [,ip6-host=addr][,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 1565 " [,dns=addr][,ip6-dns=addr][,dnssearch=domain][,tftp=dir]\n" 1566 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 1567#ifndef _WIN32 1568 "[,smb=dir[,smbserver=addr]]\n" 1569#endif 1570 " configure a user mode network backend with ID 'str',\n" 1571 " its DHCP server and optional services\n" 1572#endif 1573#ifdef _WIN32 1574 "-netdev tap,id=str,ifname=name\n" 1575 " configure a host TAP network backend with ID 'str'\n" 1576#else 1577 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 1578 " [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 1579 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 1580 " configure a host TAP network backend with ID 'str'\n" 1581 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 1582 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 1583 " to deconfigure it\n" 1584 " use '[down]script=no' to disable script execution\n" 1585 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 1586 " configure it\n" 1587 " use 'fd=h' to connect to an already opened TAP interface\n" 1588 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 1589 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 1590 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 1591 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 1592 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 1593 " use vhost=on to enable experimental in kernel accelerator\n" 1594 " (only has effect for virtio guests which use MSIX)\n" 1595 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 1596 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 1597 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 1598 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 1599 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 1600 " configure a host TAP network backend with ID 'str' that is\n" 1601 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1602 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 1603#endif 1604#ifdef __linux__ 1605 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 1606 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 1607 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 1608 " [,rxcookie=rxcookie][,offset=offset]\n" 1609 " configure a network backend with ID 'str' connected to\n" 1610 " an Ethernet over L2TPv3 pseudowire.\n" 1611 " Linux kernel 3.3+ as well as most routers can talk\n" 1612 " L2TPv3. This transport allows connecting a VM to a VM,\n" 1613 " VM to a router and even VM to Host. It is a nearly-universal\n" 1614 " standard (RFC3391). Note - this implementation uses static\n" 1615 " pre-configured tunnels (same as the Linux kernel).\n" 1616 " use 'src=' to specify source address\n" 1617 " use 'dst=' to specify destination address\n" 1618 " use 'udp=on' to specify udp encapsulation\n" 1619 " use 'srcport=' to specify source udp port\n" 1620 " use 'dstport=' to specify destination udp port\n" 1621 " use 'ipv6=on' to force v6\n" 1622 " L2TPv3 uses cookies to prevent misconfiguration as\n" 1623 " well as a weak security measure\n" 1624 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 1625 " use 'txcookie=0x012345678' to specify a txcookie\n" 1626 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 1627 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 1628 " use 'pincounter=on' to work around broken counter handling in peer\n" 1629 " use 'offset=X' to add an extra offset between header and data\n" 1630#endif 1631 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 1632 " configure a network backend to connect to another network\n" 1633 " using a socket connection\n" 1634 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 1635 " configure a network backend to connect to a multicast maddr and port\n" 1636 " use 'localaddr=addr' to specify the host address to send packets from\n" 1637 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 1638 " configure a network backend to connect to another network\n" 1639 " using an UDP tunnel\n" 1640#ifdef CONFIG_VDE 1641 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 1642 " configure a network backend to connect to port 'n' of a vde switch\n" 1643 " running on host and listening for incoming connections on 'socketpath'.\n" 1644 " Use group 'groupname' and mode 'octalmode' to change default\n" 1645 " ownership and permissions for communication port.\n" 1646#endif 1647#ifdef CONFIG_NETMAP 1648 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 1649 " attach to the existing netmap-enabled network interface 'name', or to a\n" 1650 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 1651 " netmap device, defaults to '/dev/netmap')\n" 1652#endif 1653 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 1654 " configure a vhost-user network, backed by a chardev 'dev'\n" 1655 "-netdev hubport,id=str,hubid=n\n" 1656 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL) 1657DEF("net", HAS_ARG, QEMU_OPTION_net, 1658 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 1659 " old way to create a new NIC and connect it to VLAN 'n'\n" 1660 " (use the '-device devtype,netdev=str' option if possible instead)\n" 1661 "-net dump[,vlan=n][,file=f][,len=n]\n" 1662 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n" 1663 "-net none use it alone to have zero network devices. If no -net option\n" 1664 " is provided, the default is '-net nic -net user'\n" 1665 "-net [" 1666#ifdef CONFIG_SLIRP 1667 "user|" 1668#endif 1669 "tap|" 1670 "bridge|" 1671#ifdef CONFIG_VDE 1672 "vde|" 1673#endif 1674#ifdef CONFIG_NETMAP 1675 "netmap|" 1676#endif 1677 "socket][,vlan=n][,option][,option][,...]\n" 1678 " old way to initialize a host network interface\n" 1679 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 1680STEXI 1681@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 1682@findex -net 1683Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n} 1684= 0 is the default). The NIC is an e1000 by default on the PC 1685target. Optionally, the MAC address can be changed to @var{mac}, the 1686device address set to @var{addr} (PCI cards only), 1687and a @var{name} can be assigned for use in monitor commands. 1688Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 1689that the card should have; this option currently only affects virtio cards; set 1690@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 1691NIC is created. QEMU can emulate several different models of network card. 1692Valid values for @var{type} are 1693@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er}, 1694@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139}, 1695@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}. 1696Not all devices are supported on all targets. Use @code{-net nic,model=help} 1697for a list of available devices for your target. 1698 1699@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 1700@findex -netdev 1701@item -net user[,@var{option}][,@var{option}][,...] 1702Use the user mode network stack which requires no administrator 1703privilege to run. Valid options are: 1704 1705@table @option 1706@item vlan=@var{n} 1707Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default). 1708 1709@item id=@var{id} 1710@itemx name=@var{name} 1711Assign symbolic name for use in monitor commands. 1712 1713@item net=@var{addr}[/@var{mask}] 1714Set IP network address the guest will see. Optionally specify the netmask, 1715either in the form a.b.c.d or as number of valid top-most bits. Default is 171610.0.2.0/24. 1717 1718@item host=@var{addr} 1719Specify the guest-visible address of the host. Default is the 2nd IP in the 1720guest network, i.e. x.x.x.2. 1721 1722@item ip6-net=@var{addr}[/@var{int}] 1723Set IPv6 network address the guest will see. Optionally specify the prefix 1724size, as number of valid top-most bits. Default is fec0::/64. 1725 1726@item ip6-host=@var{addr} 1727Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 1728the guest network, i.e. xxxx::2. 1729 1730@item restrict=on|off 1731If this option is enabled, the guest will be isolated, i.e. it will not be 1732able to contact the host and no guest IP packets will be routed over the host 1733to the outside. This option does not affect any explicitly set forwarding rules. 1734 1735@item hostname=@var{name} 1736Specifies the client hostname reported by the built-in DHCP server. 1737 1738@item dhcpstart=@var{addr} 1739Specify the first of the 16 IPs the built-in DHCP server can assign. Default 1740is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 1741 1742@item dns=@var{addr} 1743Specify the guest-visible address of the virtual nameserver. The address must 1744be different from the host address. Default is the 3rd IP in the guest network, 1745i.e. x.x.x.3. 1746 1747@item ip6-dns=@var{addr} 1748Specify the guest-visible address of the IPv6 virtual nameserver. The address 1749must be different from the host address. Default is the 3rd IP in the guest 1750network, i.e. xxxx::3. 1751 1752@item dnssearch=@var{domain} 1753Provides an entry for the domain-search list sent by the built-in 1754DHCP server. More than one domain suffix can be transmitted by specifying 1755this option multiple times. If supported, this will cause the guest to 1756automatically try to append the given domain suffix(es) in case a domain name 1757can not be resolved. 1758 1759Example: 1760@example 1761qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...] 1762@end example 1763 1764@item tftp=@var{dir} 1765When using the user mode network stack, activate a built-in TFTP 1766server. The files in @var{dir} will be exposed as the root of a TFTP server. 1767The TFTP client on the guest must be configured in binary mode (use the command 1768@code{bin} of the Unix TFTP client). 1769 1770@item bootfile=@var{file} 1771When using the user mode network stack, broadcast @var{file} as the BOOTP 1772filename. In conjunction with @option{tftp}, this can be used to network boot 1773a guest from a local directory. 1774 1775Example (using pxelinux): 1776@example 1777qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 1778@end example 1779 1780@item smb=@var{dir}[,smbserver=@var{addr}] 1781When using the user mode network stack, activate a built-in SMB 1782server so that Windows OSes can access to the host files in @file{@var{dir}} 1783transparently. The IP address of the SMB server can be set to @var{addr}. By 1784default the 4th IP in the guest network is used, i.e. x.x.x.4. 1785 1786In the guest Windows OS, the line: 1787@example 178810.0.2.4 smbserver 1789@end example 1790must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 1791or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 1792 1793Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 1794 1795Note that a SAMBA server must be installed on the host OS. 1796QEMU was tested successfully with smbd versions from Red Hat 9, 1797Fedora Core 3 and OpenSUSE 11.x. 1798 1799@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 1800Redirect incoming TCP or UDP connections to the host port @var{hostport} to 1801the guest IP address @var{guestaddr} on guest port @var{guestport}. If 1802@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 1803given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 1804be bound to a specific host interface. If no connection type is set, TCP is 1805used. This option can be given multiple times. 1806 1807For example, to redirect host X11 connection from screen 1 to guest 1808screen 0, use the following: 1809 1810@example 1811# on the host 1812qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...] 1813# this host xterm should open in the guest X11 server 1814xterm -display :1 1815@end example 1816 1817To redirect telnet connections from host port 5555 to telnet port on 1818the guest, use the following: 1819 1820@example 1821# on the host 1822qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...] 1823telnet localhost 5555 1824@end example 1825 1826Then when you use on the host @code{telnet localhost 5555}, you 1827connect to the guest telnet server. 1828 1829@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 1830@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 1831Forward guest TCP connections to the IP address @var{server} on port @var{port} 1832to the character device @var{dev} or to a program executed by @var{cmd:command} 1833which gets spawned for each connection. This option can be given multiple times. 1834 1835You can either use a chardev directly and have that one used throughout QEMU's 1836lifetime, like in the following example: 1837 1838@example 1839# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 1840# the guest accesses it 1841qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...] 1842@end example 1843 1844Or you can execute a command on every TCP connection established by the guest, 1845so that QEMU behaves similar to an inetd process for that virtual server: 1846 1847@example 1848# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 1849# and connect the TCP stream to its stdin/stdout 1850qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 1851@end example 1852 1853@end table 1854 1855Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still 1856processed and applied to -net user. Mixing them with the new configuration 1857syntax gives undefined results. Their use for new applications is discouraged 1858as they will be removed from future versions. 1859 1860@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}] 1861@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}] 1862Connect the host TAP network interface @var{name} to VLAN @var{n}. 1863 1864Use the network script @var{file} to configure it and the network script 1865@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 1866automatically provides one. The default network configure script is 1867@file{/etc/qemu-ifup} and the default network deconfigure script is 1868@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 1869to disable script execution. 1870 1871If running QEMU as an unprivileged user, use the network helper 1872@var{helper} to configure the TAP interface. The default network 1873helper executable is @file{/path/to/qemu-bridge-helper}. 1874 1875@option{fd}=@var{h} can be used to specify the handle of an already 1876opened host TAP interface. 1877 1878Examples: 1879 1880@example 1881#launch a QEMU instance with the default network script 1882qemu-system-i386 linux.img -net nic -net tap 1883@end example 1884 1885@example 1886#launch a QEMU instance with two NICs, each one connected 1887#to a TAP device 1888qemu-system-i386 linux.img \ 1889 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \ 1890 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1 1891@end example 1892 1893@example 1894#launch a QEMU instance with the default network helper to 1895#connect a TAP device to bridge br0 1896qemu-system-i386 linux.img \ 1897 -net nic -net tap,"helper=/path/to/qemu-bridge-helper" 1898@end example 1899 1900@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 1901@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}] 1902Connect a host TAP network interface to a host bridge device. 1903 1904Use the network helper @var{helper} to configure the TAP interface and 1905attach it to the bridge. The default network helper executable is 1906@file{/path/to/qemu-bridge-helper} and the default bridge 1907device is @file{br0}. 1908 1909Examples: 1910 1911@example 1912#launch a QEMU instance with the default network helper to 1913#connect a TAP device to bridge br0 1914qemu-system-i386 linux.img -net bridge -net nic,model=virtio 1915@end example 1916 1917@example 1918#launch a QEMU instance with the default network helper to 1919#connect a TAP device to bridge qemubr0 1920qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio 1921@end example 1922 1923@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 1924@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 1925 1926Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual 1927machine using a TCP socket connection. If @option{listen} is 1928specified, QEMU waits for incoming connections on @var{port} 1929(@var{host} is optional). @option{connect} is used to connect to 1930another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 1931specifies an already opened TCP socket. 1932 1933Example: 1934@example 1935# launch a first QEMU instance 1936qemu-system-i386 linux.img \ 1937 -net nic,macaddr=52:54:00:12:34:56 \ 1938 -net socket,listen=:1234 1939# connect the VLAN 0 of this instance to the VLAN 0 1940# of the first instance 1941qemu-system-i386 linux.img \ 1942 -net nic,macaddr=52:54:00:12:34:57 \ 1943 -net socket,connect=127.0.0.1:1234 1944@end example 1945 1946@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 1947@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 1948 1949Create a VLAN @var{n} shared with another QEMU virtual 1950machines using a UDP multicast socket, effectively making a bus for 1951every QEMU with same multicast address @var{maddr} and @var{port}. 1952NOTES: 1953@enumerate 1954@item 1955Several QEMU can be running on different hosts and share same bus (assuming 1956correct multicast setup for these hosts). 1957@item 1958mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 1959@url{http://user-mode-linux.sf.net}. 1960@item 1961Use @option{fd=h} to specify an already opened UDP multicast socket. 1962@end enumerate 1963 1964Example: 1965@example 1966# launch one QEMU instance 1967qemu-system-i386 linux.img \ 1968 -net nic,macaddr=52:54:00:12:34:56 \ 1969 -net socket,mcast=230.0.0.1:1234 1970# launch another QEMU instance on same "bus" 1971qemu-system-i386 linux.img \ 1972 -net nic,macaddr=52:54:00:12:34:57 \ 1973 -net socket,mcast=230.0.0.1:1234 1974# launch yet another QEMU instance on same "bus" 1975qemu-system-i386 linux.img \ 1976 -net nic,macaddr=52:54:00:12:34:58 \ 1977 -net socket,mcast=230.0.0.1:1234 1978@end example 1979 1980Example (User Mode Linux compat.): 1981@example 1982# launch QEMU instance (note mcast address selected 1983# is UML's default) 1984qemu-system-i386 linux.img \ 1985 -net nic,macaddr=52:54:00:12:34:56 \ 1986 -net socket,mcast=239.192.168.1:1102 1987# launch UML 1988/path/to/linux ubd0=/path/to/root_fs eth0=mcast 1989@end example 1990 1991Example (send packets from host's 1.2.3.4): 1992@example 1993qemu-system-i386 linux.img \ 1994 -net nic,macaddr=52:54:00:12:34:56 \ 1995 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4 1996@end example 1997 1998@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}] 1999@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}] 2000Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular 2001protocol to transport Ethernet (and other Layer 2) data frames between 2002two systems. It is present in routers, firewalls and the Linux kernel 2003(from version 3.3 onwards). 2004 2005This transport allows a VM to communicate to another VM, router or firewall directly. 2006 2007@item src=@var{srcaddr} 2008 source address (mandatory) 2009@item dst=@var{dstaddr} 2010 destination address (mandatory) 2011@item udp 2012 select udp encapsulation (default is ip). 2013@item srcport=@var{srcport} 2014 source udp port. 2015@item dstport=@var{dstport} 2016 destination udp port. 2017@item ipv6 2018 force v6, otherwise defaults to v4. 2019@item rxcookie=@var{rxcookie} 2020@itemx txcookie=@var{txcookie} 2021 Cookies are a weak form of security in the l2tpv3 specification. 2022Their function is mostly to prevent misconfiguration. By default they are 32 2023bit. 2024@item cookie64 2025 Set cookie size to 64 bit instead of the default 32 2026@item counter=off 2027 Force a 'cut-down' L2TPv3 with no counter as in 2028draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2029@item pincounter=on 2030 Work around broken counter handling in peer. This may also help on 2031networks which have packet reorder. 2032@item offset=@var{offset} 2033 Add an extra offset between header and data 2034 2035For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2036on the remote Linux host 1.2.3.4: 2037@example 2038# Setup tunnel on linux host using raw ip as encapsulation 2039# on 1.2.3.4 2040ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2041 encap udp udp_sport 16384 udp_dport 16384 2042ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2043 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2044ifconfig vmtunnel0 mtu 1500 2045ifconfig vmtunnel0 up 2046brctl addif br-lan vmtunnel0 2047 2048 2049# on 4.3.2.1 2050# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2051 2052qemu-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 2053 2054 2055@end example 2056 2057@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2058@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2059Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and 2060listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2061and MODE @var{octalmode} to change default ownership and permissions for 2062communication port. This option is only available if QEMU has been compiled 2063with vde support enabled. 2064 2065Example: 2066@example 2067# launch vde switch 2068vde_switch -F -sock /tmp/myswitch 2069# launch QEMU instance 2070qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch 2071@end example 2072 2073@item -netdev hubport,id=@var{id},hubid=@var{hubid} 2074 2075Create a hub port on QEMU "vlan" @var{hubid}. 2076 2077The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single 2078netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the 2079required hub automatically. 2080 2081@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2082 2083Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2084be a unix domain socket backed one. The vhost-user uses a specifically defined 2085protocol to pass vhost ioctl replacement messages to an application on the other 2086end of the socket. On non-MSIX guests, the feature can be forced with 2087@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2088be created for multiqueue vhost-user. 2089 2090Example: 2091@example 2092qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2093 -numa node,memdev=mem \ 2094 -chardev socket,path=/path/to/socket \ 2095 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2096 -device virtio-net-pci,netdev=net0 2097@end example 2098 2099@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}] 2100Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default). 2101At most @var{len} bytes (64k by default) per packet are stored. The file format is 2102libpcap, so it can be analyzed with tools such as tcpdump or Wireshark. 2103Note: For devices created with '-netdev', use '-object filter-dump,...' instead. 2104 2105@item -net none 2106Indicate that no network devices should be configured. It is used to 2107override the default configuration (@option{-net nic -net user}) which 2108is activated if no @option{-net} options are provided. 2109ETEXI 2110 2111STEXI 2112@end table 2113ETEXI 2114DEFHEADING() 2115 2116DEFHEADING(Character device options:) 2117STEXI 2118 2119The general form of a character device option is: 2120@table @option 2121ETEXI 2122 2123DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2124 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2125 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2126 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n" 2127 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n" 2128 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n" 2129 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2130 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2131 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2132 " [,logfile=PATH][,logappend=on|off]\n" 2133 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2134 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2135 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2136 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2137 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2138 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2139#ifdef _WIN32 2140 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2141 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2142#else 2143 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2144 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2145#endif 2146#ifdef CONFIG_BRLAPI 2147 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2148#endif 2149#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2150 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2151 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2152 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2153#endif 2154#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2155 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2156 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2157#endif 2158#if defined(CONFIG_SPICE) 2159 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2160 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2161#endif 2162 , QEMU_ARCH_ALL 2163) 2164 2165STEXI 2166@item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}] 2167@findex -chardev 2168Backend is one of: 2169@option{null}, 2170@option{socket}, 2171@option{udp}, 2172@option{msmouse}, 2173@option{vc}, 2174@option{ringbuf}, 2175@option{file}, 2176@option{pipe}, 2177@option{console}, 2178@option{serial}, 2179@option{pty}, 2180@option{stdio}, 2181@option{braille}, 2182@option{tty}, 2183@option{parallel}, 2184@option{parport}, 2185@option{spicevmc}. 2186@option{spiceport}. 2187The specific backend will determine the applicable options. 2188 2189All devices must have an id, which can be any string up to 127 characters long. 2190It is used to uniquely identify this device in other command line directives. 2191 2192A character device may be used in multiplexing mode by multiple front-ends. 2193Specify @option{mux=on} to enable this mode. 2194A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2195backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2196If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2197create a multiplexer with your specified ID, and you can then configure multiple 2198front ends to use that chardev ID for their input/output. Up to four different 2199front ends can be connected to a single multiplexed chardev. (Without 2200multiplexing enabled, a chardev can only be used by a single front end.) 2201For instance you could use this to allow a single stdio chardev to be used by 2202two serial ports and the QEMU monitor: 2203 2204@example 2205-chardev stdio,mux=on,id=char0 \ 2206-mon chardev=char0,mode=readline,default \ 2207-serial chardev:char0 \ 2208-serial chardev:char0 2209@end example 2210 2211You can have more than one multiplexer in a system configuration; for instance 2212you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2213multiplexed between the QEMU monitor and a parallel port: 2214 2215@example 2216-chardev stdio,mux=on,id=char0 \ 2217-mon chardev=char0,mode=readline,default \ 2218-parallel chardev:char0 \ 2219-chardev tcp,...,mux=on,id=char1 \ 2220-serial chardev:char1 \ 2221-serial chardev:char1 2222@end example 2223 2224When you're using a multiplexed character device, some escape sequences are 2225interpreted in the input. @xref{mux_keys, Keys in the character backend 2226multiplexer}. 2227 2228Note that some other command line options may implicitly create multiplexed 2229character backends; for instance @option{-serial mon:stdio} creates a 2230multiplexed stdio backend connected to the serial port and the QEMU monitor, 2231and @option{-nographic} also multiplexes the console and the monitor to 2232stdio. 2233 2234There is currently no support for multiplexing in the other direction 2235(where a single QEMU front end takes input and output from multiple chardevs). 2236 2237Every backend supports the @option{logfile} option, which supplies the path 2238to a file to record all data transmitted via the backend. The @option{logappend} 2239option controls whether the log file will be truncated or appended to when 2240opened. 2241 2242Further options to each backend are described below. 2243 2244@item -chardev null ,id=@var{id} 2245A void device. This device will not emit any data, and will drop any data it 2246receives. The null backend does not take any options. 2247 2248@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}] 2249 2250Create a two-way stream socket, which can be either a TCP or a unix socket. A 2251unix socket will be created if @option{path} is specified. Behaviour is 2252undefined if TCP options are specified for a unix socket. 2253 2254@option{server} specifies that the socket shall be a listening socket. 2255 2256@option{nowait} specifies that QEMU should not block waiting for a client to 2257connect to a listening socket. 2258 2259@option{telnet} specifies that traffic on the socket should interpret telnet 2260escape sequences. 2261 2262@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2263the remote end goes away. qemu will delay this many seconds and then attempt 2264to reconnect. Zero disables reconnecting, and is the default. 2265 2266@option{tls-creds} requests enablement of the TLS protocol for encryption, 2267and specifies the id of the TLS credentials to use for the handshake. The 2268credentials must be previously created with the @option{-object tls-creds} 2269argument. 2270 2271TCP and unix socket options are given below: 2272 2273@table @option 2274 2275@item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay] 2276 2277@option{host} for a listening socket specifies the local address to be bound. 2278For a connecting socket species the remote host to connect to. @option{host} is 2279optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2280 2281@option{port} for a listening socket specifies the local port to be bound. For a 2282connecting socket specifies the port on the remote host to connect to. 2283@option{port} can be given as either a port number or a service name. 2284@option{port} is required. 2285 2286@option{to} is only relevant to listening sockets. If it is specified, and 2287@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2288to and including @option{to} until it succeeds. @option{to} must be specified 2289as a port number. 2290 2291@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2292If neither is specified the socket may use either protocol. 2293 2294@option{nodelay} disables the Nagle algorithm. 2295 2296@item unix options: path=@var{path} 2297 2298@option{path} specifies the local path of the unix socket. @option{path} is 2299required. 2300 2301@end table 2302 2303@item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6] 2304 2305Sends all traffic from the guest to a remote host over UDP. 2306 2307@option{host} specifies the remote host to connect to. If not specified it 2308defaults to @code{localhost}. 2309 2310@option{port} specifies the port on the remote host to connect to. @option{port} 2311is required. 2312 2313@option{localaddr} specifies the local address to bind to. If not specified it 2314defaults to @code{0.0.0.0}. 2315 2316@option{localport} specifies the local port to bind to. If not specified any 2317available local port will be used. 2318 2319@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2320If neither is specified the device may use either protocol. 2321 2322@item -chardev msmouse ,id=@var{id} 2323 2324Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2325take any options. 2326 2327@item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]] 2328 2329Connect to a QEMU text console. @option{vc} may optionally be given a specific 2330size. 2331 2332@option{width} and @option{height} specify the width and height respectively of 2333the console, in pixels. 2334 2335@option{cols} and @option{rows} specify that the console be sized to fit a text 2336console with the given dimensions. 2337 2338@item -chardev ringbuf ,id=@var{id} [,size=@var{size}] 2339 2340Create a ring buffer with fixed size @option{size}. 2341@var{size} must be a power of two, and defaults to @code{64K}). 2342 2343@item -chardev file ,id=@var{id} ,path=@var{path} 2344 2345Log all traffic received from the guest to a file. 2346 2347@option{path} specifies the path of the file to be opened. This file will be 2348created if it does not already exist, and overwritten if it does. @option{path} 2349is required. 2350 2351@item -chardev pipe ,id=@var{id} ,path=@var{path} 2352 2353Create a two-way connection to the guest. The behaviour differs slightly between 2354Windows hosts and other hosts: 2355 2356On Windows, a single duplex pipe will be created at 2357@file{\\.pipe\@option{path}}. 2358 2359On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2360@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2361received by the guest. Data written by the guest can be read from 2362@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2363be present. 2364 2365@option{path} forms part of the pipe path as described above. @option{path} is 2366required. 2367 2368@item -chardev console ,id=@var{id} 2369 2370Send traffic from the guest to QEMU's standard output. @option{console} does not 2371take any options. 2372 2373@option{console} is only available on Windows hosts. 2374 2375@item -chardev serial ,id=@var{id} ,path=@option{path} 2376 2377Send traffic from the guest to a serial device on the host. 2378 2379On Unix hosts serial will actually accept any tty device, 2380not only serial lines. 2381 2382@option{path} specifies the name of the serial device to open. 2383 2384@item -chardev pty ,id=@var{id} 2385 2386Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2387not take any options. 2388 2389@option{pty} is not available on Windows hosts. 2390 2391@item -chardev stdio ,id=@var{id} [,signal=on|off] 2392Connect to standard input and standard output of the QEMU process. 2393 2394@option{signal} controls if signals are enabled on the terminal, that includes 2395exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2396default, use @option{signal=off} to disable it. 2397 2398@option{stdio} is not available on Windows hosts. 2399 2400@item -chardev braille ,id=@var{id} 2401 2402Connect to a local BrlAPI server. @option{braille} does not take any options. 2403 2404@item -chardev tty ,id=@var{id} ,path=@var{path} 2405 2406@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 2407DragonFlyBSD hosts. It is an alias for @option{serial}. 2408 2409@option{path} specifies the path to the tty. @option{path} is required. 2410 2411@item -chardev parallel ,id=@var{id} ,path=@var{path} 2412@itemx -chardev parport ,id=@var{id} ,path=@var{path} 2413 2414@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 2415 2416Connect to a local parallel port. 2417 2418@option{path} specifies the path to the parallel port device. @option{path} is 2419required. 2420 2421@item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2422 2423@option{spicevmc} is only available when spice support is built in. 2424 2425@option{debug} debug level for spicevmc 2426 2427@option{name} name of spice channel to connect to 2428 2429Connect to a spice virtual machine channel, such as vdiport. 2430 2431@item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2432 2433@option{spiceport} is only available when spice support is built in. 2434 2435@option{debug} debug level for spicevmc 2436 2437@option{name} name of spice port to connect to 2438 2439Connect to a spice port, allowing a Spice client to handle the traffic 2440identified by a name (preferably a fqdn). 2441ETEXI 2442 2443STEXI 2444@end table 2445ETEXI 2446DEFHEADING() 2447 2448DEFHEADING(Device URL Syntax:) 2449STEXI 2450 2451In addition to using normal file images for the emulated storage devices, 2452QEMU can also use networked resources such as iSCSI devices. These are 2453specified using a special URL syntax. 2454 2455@table @option 2456@item iSCSI 2457iSCSI support allows QEMU to access iSCSI resources directly and use as 2458images for the guest storage. Both disk and cdrom images are supported. 2459 2460Syntax for specifying iSCSI LUNs is 2461``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>'' 2462 2463By default qemu will use the iSCSI initiator-name 2464'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command 2465line or a configuration file. 2466 2467Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect 2468stalled requests and force a reestablishment of the session. The timeout 2469is specified in seconds. The default is 0 which means no timeout. Libiscsi 24701.15.0 or greater is required for this feature. 2471 2472Example (without authentication): 2473@example 2474qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \ 2475 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \ 2476 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2477@end example 2478 2479Example (CHAP username/password via URL): 2480@example 2481qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1 2482@end example 2483 2484Example (CHAP username/password via environment variables): 2485@example 2486LIBISCSI_CHAP_USERNAME="user" \ 2487LIBISCSI_CHAP_PASSWORD="password" \ 2488qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2489@end example 2490 2491iSCSI support is an optional feature of QEMU and only available when 2492compiled and linked against libiscsi. 2493ETEXI 2494DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 2495 "-iscsi [user=user][,password=password]\n" 2496 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 2497 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 2498 " [,timeout=timeout]\n" 2499 " iSCSI session parameters\n", QEMU_ARCH_ALL) 2500STEXI 2501 2502iSCSI parameters such as username and password can also be specified via 2503a configuration file. See qemu-doc for more information and examples. 2504 2505@item NBD 2506QEMU supports NBD (Network Block Devices) both using TCP protocol as well 2507as Unix Domain Sockets. 2508 2509Syntax for specifying a NBD device using TCP 2510``nbd:<server-ip>:<port>[:exportname=<export>]'' 2511 2512Syntax for specifying a NBD device using Unix Domain Sockets 2513``nbd:unix:<domain-socket>[:exportname=<export>]'' 2514 2515 2516Example for TCP 2517@example 2518qemu-system-i386 --drive file=nbd:192.0.2.1:30000 2519@end example 2520 2521Example for Unix Domain Sockets 2522@example 2523qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket 2524@end example 2525 2526@item SSH 2527QEMU supports SSH (Secure Shell) access to remote disks. 2528 2529Examples: 2530@example 2531qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img 2532qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img 2533@end example 2534 2535Currently authentication must be done using ssh-agent. Other 2536authentication methods may be supported in future. 2537 2538@item Sheepdog 2539Sheepdog is a distributed storage system for QEMU. 2540QEMU supports using either local sheepdog devices or remote networked 2541devices. 2542 2543Syntax for specifying a sheepdog device 2544@example 2545sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag] 2546@end example 2547 2548Example 2549@example 2550qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine 2551@end example 2552 2553See also @url{http://http://www.osrg.net/sheepdog/}. 2554 2555@item GlusterFS 2556GlusterFS is an user space distributed file system. 2557QEMU supports the use of GlusterFS volumes for hosting VM disk images using 2558TCP, Unix Domain Sockets and RDMA transport protocols. 2559 2560Syntax for specifying a VM disk image on GlusterFS volume is 2561@example 2562gluster[+transport]://[server[:port]]/volname/image[?socket=...] 2563@end example 2564 2565 2566Example 2567@example 2568qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img 2569@end example 2570 2571See also @url{http://www.gluster.org}. 2572 2573@item HTTP/HTTPS/FTP/FTPS/TFTP 2574QEMU supports read-only access to files accessed over http(s), ftp(s) and tftp. 2575 2576Syntax using a single filename: 2577@example 2578<protocol>://[<username>[:<password>]@@]<host>/<path> 2579@end example 2580 2581where: 2582@table @option 2583@item protocol 2584'http', 'https', 'ftp', 'ftps', or 'tftp'. 2585 2586@item username 2587Optional username for authentication to the remote server. 2588 2589@item password 2590Optional password for authentication to the remote server. 2591 2592@item host 2593Address of the remote server. 2594 2595@item path 2596Path on the remote server, including any query string. 2597@end table 2598 2599The following options are also supported: 2600@table @option 2601@item url 2602The full URL when passing options to the driver explicitly. 2603 2604@item readahead 2605The amount of data to read ahead with each range request to the remote server. 2606This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it 2607does not have a suffix, it will be assumed to be in bytes. The value must be a 2608multiple of 512 bytes. It defaults to 256k. 2609 2610@item sslverify 2611Whether to verify the remote server's certificate when connecting over SSL. It 2612can have the value 'on' or 'off'. It defaults to 'on'. 2613 2614@item cookie 2615Send this cookie (it can also be a list of cookies separated by ';') with 2616each outgoing request. Only supported when using protocols such as HTTP 2617which support cookies, otherwise ignored. 2618 2619@item timeout 2620Set the timeout in seconds of the CURL connection. This timeout is the time 2621that CURL waits for a response from the remote server to get the size of the 2622image to be downloaded. If not set, the default timeout of 5 seconds is used. 2623@end table 2624 2625Note that when passing options to qemu explicitly, @option{driver} is the value 2626of <protocol>. 2627 2628Example: boot from a remote Fedora 20 live ISO image 2629@example 2630qemu-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 2631 2632qemu-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 2633@end example 2634 2635Example: boot from a remote Fedora 20 cloud image using a local overlay for 2636writes, copy-on-read, and a readahead of 64k 2637@example 2638qemu-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 2639 2640qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on 2641@end example 2642 2643Example: boot from an image stored on a VMware vSphere server with a self-signed 2644certificate using a local overlay for writes, a readahead of 64k and a timeout 2645of 10 seconds. 2646@example 2647qemu-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 2648 2649qemu-system-x86_64 -drive file=/tmp/test.qcow2 2650@end example 2651ETEXI 2652 2653STEXI 2654@end table 2655ETEXI 2656 2657DEFHEADING(Bluetooth(R) options:) 2658STEXI 2659@table @option 2660ETEXI 2661 2662DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 2663 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 2664 "-bt hci,host[:id]\n" \ 2665 " use host's HCI with the given name\n" \ 2666 "-bt hci[,vlan=n]\n" \ 2667 " emulate a standard HCI in virtual scatternet 'n'\n" \ 2668 "-bt vhci[,vlan=n]\n" \ 2669 " add host computer to virtual scatternet 'n' using VHCI\n" \ 2670 "-bt device:dev[,vlan=n]\n" \ 2671 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 2672 QEMU_ARCH_ALL) 2673STEXI 2674@item -bt hci[...] 2675@findex -bt 2676Defines the function of the corresponding Bluetooth HCI. -bt options 2677are matched with the HCIs present in the chosen machine type. For 2678example when emulating a machine with only one HCI built into it, only 2679the first @code{-bt hci[...]} option is valid and defines the HCI's 2680logic. The Transport Layer is decided by the machine type. Currently 2681the machines @code{n800} and @code{n810} have one HCI and all other 2682machines have none. 2683 2684@anchor{bt-hcis} 2685The following three types are recognized: 2686 2687@table @option 2688@item -bt hci,null 2689(default) The corresponding Bluetooth HCI assumes no internal logic 2690and will not respond to any HCI commands or emit events. 2691 2692@item -bt hci,host[:@var{id}] 2693(@code{bluez} only) The corresponding HCI passes commands / events 2694to / from the physical HCI identified by the name @var{id} (default: 2695@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 2696capable systems like Linux. 2697 2698@item -bt hci[,vlan=@var{n}] 2699Add a virtual, standard HCI that will participate in the Bluetooth 2700scatternet @var{n} (default @code{0}). Similarly to @option{-net} 2701VLANs, devices inside a bluetooth network @var{n} can only communicate 2702with other devices in the same network (scatternet). 2703@end table 2704 2705@item -bt vhci[,vlan=@var{n}] 2706(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 2707to the host bluetooth stack instead of to the emulated target. This 2708allows the host and target machines to participate in a common scatternet 2709and communicate. Requires the Linux @code{vhci} driver installed. Can 2710be used as following: 2711 2712@example 2713qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 2714@end example 2715 2716@item -bt device:@var{dev}[,vlan=@var{n}] 2717Emulate a bluetooth device @var{dev} and place it in network @var{n} 2718(default @code{0}). QEMU can only emulate one type of bluetooth devices 2719currently: 2720 2721@table @option 2722@item keyboard 2723Virtual wireless keyboard implementing the HIDP bluetooth profile. 2724@end table 2725ETEXI 2726 2727STEXI 2728@end table 2729ETEXI 2730DEFHEADING() 2731 2732#ifdef CONFIG_TPM 2733DEFHEADING(TPM device options:) 2734 2735DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 2736 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 2737 " use path to provide path to a character device; default is /dev/tpm0\n" 2738 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 2739 " not provided it will be searched for in /sys/class/misc/tpm?/device\n", 2740 QEMU_ARCH_ALL) 2741STEXI 2742 2743The general form of a TPM device option is: 2744@table @option 2745 2746@item -tpmdev @var{backend} ,id=@var{id} [,@var{options}] 2747@findex -tpmdev 2748Backend type must be: 2749@option{passthrough}. 2750 2751The specific backend type will determine the applicable options. 2752The @code{-tpmdev} option creates the TPM backend and requires a 2753@code{-device} option that specifies the TPM frontend interface model. 2754 2755Options to each backend are described below. 2756 2757Use 'help' to print all available TPM backend types. 2758@example 2759qemu -tpmdev help 2760@end example 2761 2762@item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path} 2763 2764(Linux-host only) Enable access to the host's TPM using the passthrough 2765driver. 2766 2767@option{path} specifies the path to the host's TPM device, i.e., on 2768a Linux host this would be @code{/dev/tpm0}. 2769@option{path} is optional and by default @code{/dev/tpm0} is used. 2770 2771@option{cancel-path} specifies the path to the host TPM device's sysfs 2772entry allowing for cancellation of an ongoing TPM command. 2773@option{cancel-path} is optional and by default QEMU will search for the 2774sysfs entry to use. 2775 2776Some notes about using the host's TPM with the passthrough driver: 2777 2778The TPM device accessed by the passthrough driver must not be 2779used by any other application on the host. 2780 2781Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 2782the VM's firmware (BIOS/UEFI) will not be able to initialize the 2783TPM again and may therefore not show a TPM-specific menu that would 2784otherwise allow the user to configure the TPM, e.g., allow the user to 2785enable/disable or activate/deactivate the TPM. 2786Further, if TPM ownership is released from within a VM then the host's TPM 2787will get disabled and deactivated. To enable and activate the 2788TPM again afterwards, the host has to be rebooted and the user is 2789required to enter the firmware's menu to enable and activate the TPM. 2790If the TPM is left disabled and/or deactivated most TPM commands will fail. 2791 2792To create a passthrough TPM use the following two options: 2793@example 2794-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 2795@end example 2796Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 2797@code{tpmdev=tpm0} in the device option. 2798 2799@end table 2800 2801ETEXI 2802 2803DEFHEADING() 2804 2805#endif 2806 2807DEFHEADING(Linux/Multiboot boot specific:) 2808STEXI 2809 2810When using these options, you can use a given Linux or Multiboot 2811kernel without installing it in the disk image. It can be useful 2812for easier testing of various kernels. 2813 2814@table @option 2815ETEXI 2816 2817DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 2818 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 2819STEXI 2820@item -kernel @var{bzImage} 2821@findex -kernel 2822Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 2823or in multiboot format. 2824ETEXI 2825 2826DEF("append", HAS_ARG, QEMU_OPTION_append, \ 2827 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 2828STEXI 2829@item -append @var{cmdline} 2830@findex -append 2831Use @var{cmdline} as kernel command line 2832ETEXI 2833 2834DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 2835 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 2836STEXI 2837@item -initrd @var{file} 2838@findex -initrd 2839Use @var{file} as initial ram disk. 2840 2841@item -initrd "@var{file1} arg=foo,@var{file2}" 2842 2843This syntax is only available with multiboot. 2844 2845Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 2846first module. 2847ETEXI 2848 2849DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 2850 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 2851STEXI 2852@item -dtb @var{file} 2853@findex -dtb 2854Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 2855on boot. 2856ETEXI 2857 2858STEXI 2859@end table 2860ETEXI 2861DEFHEADING() 2862 2863DEFHEADING(Debug/Expert options:) 2864STEXI 2865@table @option 2866ETEXI 2867 2868DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 2869 "-fw_cfg [name=]<name>,file=<file>\n" 2870 " add named fw_cfg entry from file\n" 2871 "-fw_cfg [name=]<name>,string=<str>\n" 2872 " add named fw_cfg entry from string\n", 2873 QEMU_ARCH_ALL) 2874STEXI 2875@item -fw_cfg [name=]@var{name},file=@var{file} 2876@findex -fw_cfg 2877Add named fw_cfg entry from file. @var{name} determines the name of 2878the entry in the fw_cfg file directory exposed to the guest. 2879 2880@item -fw_cfg [name=]@var{name},string=@var{str} 2881Add named fw_cfg entry from string. 2882ETEXI 2883 2884DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 2885 "-serial dev redirect the serial port to char device 'dev'\n", 2886 QEMU_ARCH_ALL) 2887STEXI 2888@item -serial @var{dev} 2889@findex -serial 2890Redirect the virtual serial port to host character device 2891@var{dev}. The default device is @code{vc} in graphical mode and 2892@code{stdio} in non graphical mode. 2893 2894This option can be used several times to simulate up to 4 serial 2895ports. 2896 2897Use @code{-serial none} to disable all serial ports. 2898 2899Available character devices are: 2900@table @option 2901@item vc[:@var{W}x@var{H}] 2902Virtual console. Optionally, a width and height can be given in pixel with 2903@example 2904vc:800x600 2905@end example 2906It is also possible to specify width or height in characters: 2907@example 2908vc:80Cx24C 2909@end example 2910@item pty 2911[Linux only] Pseudo TTY (a new PTY is automatically allocated) 2912@item none 2913No device is allocated. 2914@item null 2915void device 2916@item chardev:@var{id} 2917Use a named character device defined with the @code{-chardev} option. 2918@item /dev/XXX 2919[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 2920parameters are set according to the emulated ones. 2921@item /dev/parport@var{N} 2922[Linux only, parallel port only] Use host parallel port 2923@var{N}. Currently SPP and EPP parallel port features can be used. 2924@item file:@var{filename} 2925Write output to @var{filename}. No character can be read. 2926@item stdio 2927[Unix only] standard input/output 2928@item pipe:@var{filename} 2929name pipe @var{filename} 2930@item COM@var{n} 2931[Windows only] Use host serial port @var{n} 2932@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 2933This implements UDP Net Console. 2934When @var{remote_host} or @var{src_ip} are not specified 2935they default to @code{0.0.0.0}. 2936When not using a specified @var{src_port} a random port is automatically chosen. 2937 2938If you just want a simple readonly console you can use @code{netcat} or 2939@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 2940@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 2941will appear in the netconsole session. 2942 2943If you plan to send characters back via netconsole or you want to stop 2944and start QEMU a lot of times, you should have QEMU use the same 2945source port each time by using something like @code{-serial 2946udp::4555@@:4556} to QEMU. Another approach is to use a patched 2947version of netcat which can listen to a TCP port and send and receive 2948characters via udp. If you have a patched version of netcat which 2949activates telnet remote echo and single char transfer, then you can 2950use the following options to step up a netcat redirector to allow 2951telnet on port 5555 to access the QEMU port. 2952@table @code 2953@item QEMU Options: 2954-serial udp::4555@@:4556 2955@item netcat options: 2956-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 2957@item telnet options: 2958localhost 5555 2959@end table 2960 2961@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 2962The TCP Net Console has two modes of operation. It can send the serial 2963I/O to a location or wait for a connection from a location. By default 2964the TCP Net Console is sent to @var{host} at the @var{port}. If you use 2965the @var{server} option QEMU will wait for a client socket application 2966to connect to the port before continuing, unless the @code{nowait} 2967option was specified. The @code{nodelay} option disables the Nagle buffering 2968algorithm. The @code{reconnect} option only applies if @var{noserver} is 2969set, if the connection goes down it will attempt to reconnect at the 2970given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 2971one TCP connection at a time is accepted. You can use @code{telnet} to 2972connect to the corresponding character device. 2973@table @code 2974@item Example to send tcp console to 192.168.0.2 port 4444 2975-serial tcp:192.168.0.2:4444 2976@item Example to listen and wait on port 4444 for connection 2977-serial tcp::4444,server 2978@item Example to not wait and listen on ip 192.168.0.100 port 4444 2979-serial tcp:192.168.0.100:4444,server,nowait 2980@end table 2981 2982@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 2983The telnet protocol is used instead of raw tcp sockets. The options 2984work the same as if you had specified @code{-serial tcp}. The 2985difference is that the port acts like a telnet server or client using 2986telnet option negotiation. This will also allow you to send the 2987MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 2988sequence. Typically in unix telnet you do it with Control-] and then 2989type "send break" followed by pressing the enter key. 2990 2991@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 2992A unix domain socket is used instead of a tcp socket. The option works the 2993same as if you had specified @code{-serial tcp} except the unix domain socket 2994@var{path} is used for connections. 2995 2996@item mon:@var{dev_string} 2997This is a special option to allow the monitor to be multiplexed onto 2998another serial port. The monitor is accessed with key sequence of 2999@key{Control-a} and then pressing @key{c}. 3000@var{dev_string} should be any one of the serial devices specified 3001above. An example to multiplex the monitor onto a telnet server 3002listening on port 4444 would be: 3003@table @code 3004@item -serial mon:telnet::4444,server,nowait 3005@end table 3006When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3007QEMU any more but will be passed to the guest instead. 3008 3009@item braille 3010Braille device. This will use BrlAPI to display the braille output on a real 3011or fake device. 3012 3013@item msmouse 3014Three button serial mouse. Configure the guest to use Microsoft protocol. 3015@end table 3016ETEXI 3017 3018DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3019 "-parallel dev redirect the parallel port to char device 'dev'\n", 3020 QEMU_ARCH_ALL) 3021STEXI 3022@item -parallel @var{dev} 3023@findex -parallel 3024Redirect the virtual parallel port to host device @var{dev} (same 3025devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3026be used to use hardware devices connected on the corresponding host 3027parallel port. 3028 3029This option can be used several times to simulate up to 3 parallel 3030ports. 3031 3032Use @code{-parallel none} to disable all parallel ports. 3033ETEXI 3034 3035DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3036 "-monitor dev redirect the monitor to char device 'dev'\n", 3037 QEMU_ARCH_ALL) 3038STEXI 3039@item -monitor @var{dev} 3040@findex -monitor 3041Redirect the monitor to host device @var{dev} (same devices as the 3042serial port). 3043The default device is @code{vc} in graphical mode and @code{stdio} in 3044non graphical mode. 3045Use @code{-monitor none} to disable the default monitor. 3046ETEXI 3047DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3048 "-qmp dev like -monitor but opens in 'control' mode\n", 3049 QEMU_ARCH_ALL) 3050STEXI 3051@item -qmp @var{dev} 3052@findex -qmp 3053Like -monitor but opens in 'control' mode. 3054ETEXI 3055DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3056 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3057 QEMU_ARCH_ALL) 3058STEXI 3059@item -qmp-pretty @var{dev} 3060@findex -qmp-pretty 3061Like -qmp but uses pretty JSON formatting. 3062ETEXI 3063 3064DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3065 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL) 3066STEXI 3067@item -mon [chardev=]name[,mode=readline|control][,default] 3068@findex -mon 3069Setup monitor on chardev @var{name}. 3070ETEXI 3071 3072DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3073 "-debugcon dev redirect the debug console to char device 'dev'\n", 3074 QEMU_ARCH_ALL) 3075STEXI 3076@item -debugcon @var{dev} 3077@findex -debugcon 3078Redirect the debug console to host device @var{dev} (same devices as the 3079serial port). The debug console is an I/O port which is typically port 30800xe9; writing to that I/O port sends output to this device. 3081The default device is @code{vc} in graphical mode and @code{stdio} in 3082non graphical mode. 3083ETEXI 3084 3085DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3086 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3087STEXI 3088@item -pidfile @var{file} 3089@findex -pidfile 3090Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3091from a script. 3092ETEXI 3093 3094DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3095 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3096STEXI 3097@item -singlestep 3098@findex -singlestep 3099Run the emulation in single step mode. 3100ETEXI 3101 3102DEF("S", 0, QEMU_OPTION_S, \ 3103 "-S freeze CPU at startup (use 'c' to start execution)\n", 3104 QEMU_ARCH_ALL) 3105STEXI 3106@item -S 3107@findex -S 3108Do not start CPU at startup (you must type 'c' in the monitor). 3109ETEXI 3110 3111DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3112 "-realtime [mlock=on|off]\n" 3113 " run qemu with realtime features\n" 3114 " mlock=on|off controls mlock support (default: on)\n", 3115 QEMU_ARCH_ALL) 3116STEXI 3117@item -realtime mlock=on|off 3118@findex -realtime 3119Run qemu with realtime features. 3120mlocking qemu and guest memory can be enabled via @option{mlock=on} 3121(enabled by default). 3122ETEXI 3123 3124DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3125 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3126STEXI 3127@item -gdb @var{dev} 3128@findex -gdb 3129Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3130connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3131stdio are reasonable use case. The latter is allowing to start QEMU from 3132within gdb and establish the connection via a pipe: 3133@example 3134(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 3135@end example 3136ETEXI 3137 3138DEF("s", 0, QEMU_OPTION_s, \ 3139 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3140 QEMU_ARCH_ALL) 3141STEXI 3142@item -s 3143@findex -s 3144Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3145(@pxref{gdb_usage}). 3146ETEXI 3147 3148DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3149 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3150 QEMU_ARCH_ALL) 3151STEXI 3152@item -d @var{item1}[,...] 3153@findex -d 3154Enable logging of specified items. Use '-d help' for a list of log items. 3155ETEXI 3156 3157DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3158 "-D logfile output log to logfile (default stderr)\n", 3159 QEMU_ARCH_ALL) 3160STEXI 3161@item -D @var{logfile} 3162@findex -D 3163Output log in @var{logfile} instead of to stderr 3164ETEXI 3165 3166DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3167 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3168 QEMU_ARCH_ALL) 3169STEXI 3170@item -L @var{path} 3171@findex -L 3172Set the directory for the BIOS, VGA BIOS and keymaps. 3173ETEXI 3174 3175DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3176 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3177STEXI 3178@item -bios @var{file} 3179@findex -bios 3180Set the filename for the BIOS. 3181ETEXI 3182 3183DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3184 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3185STEXI 3186@item -enable-kvm 3187@findex -enable-kvm 3188Enable KVM full virtualization support. This option is only available 3189if KVM support is enabled when compiling. 3190ETEXI 3191 3192DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3193 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3194DEF("xen-create", 0, QEMU_OPTION_xen_create, 3195 "-xen-create create domain using xen hypercalls, bypassing xend\n" 3196 " warning: should not be used when xend is in use\n", 3197 QEMU_ARCH_ALL) 3198DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3199 "-xen-attach attach to existing xen domain\n" 3200 " xend will use this when starting QEMU\n", 3201 QEMU_ARCH_ALL) 3202STEXI 3203@item -xen-domid @var{id} 3204@findex -xen-domid 3205Specify xen guest domain @var{id} (XEN only). 3206@item -xen-create 3207@findex -xen-create 3208Create domain using xen hypercalls, bypassing xend. 3209Warning: should not be used when xend is in use (XEN only). 3210@item -xen-attach 3211@findex -xen-attach 3212Attach to existing xen domain. 3213xend will use this when starting QEMU (XEN only). 3214ETEXI 3215 3216DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3217 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3218STEXI 3219@item -no-reboot 3220@findex -no-reboot 3221Exit instead of rebooting. 3222ETEXI 3223 3224DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3225 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3226STEXI 3227@item -no-shutdown 3228@findex -no-shutdown 3229Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3230This allows for instance switching to monitor to commit changes to the 3231disk image. 3232ETEXI 3233 3234DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3235 "-loadvm [tag|id]\n" \ 3236 " start right away with a saved state (loadvm in monitor)\n", 3237 QEMU_ARCH_ALL) 3238STEXI 3239@item -loadvm @var{file} 3240@findex -loadvm 3241Start right away with a saved state (@code{loadvm} in monitor) 3242ETEXI 3243 3244#ifndef _WIN32 3245DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3246 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3247#endif 3248STEXI 3249@item -daemonize 3250@findex -daemonize 3251Daemonize the QEMU process after initialization. QEMU will not detach from 3252standard IO until it is ready to receive connections on any of its devices. 3253This option is a useful way for external programs to launch QEMU without having 3254to cope with initialization race conditions. 3255ETEXI 3256 3257DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3258 "-option-rom rom load a file, rom, into the option ROM space\n", 3259 QEMU_ARCH_ALL) 3260STEXI 3261@item -option-rom @var{file} 3262@findex -option-rom 3263Load the contents of @var{file} as an option ROM. 3264This option is useful to load things like EtherBoot. 3265ETEXI 3266 3267HXCOMM Silently ignored for compatibility 3268DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL) 3269 3270HXCOMM Options deprecated by -rtc 3271DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL) 3272DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL) 3273 3274DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3275 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3276 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3277 QEMU_ARCH_ALL) 3278 3279STEXI 3280 3281@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew] 3282@findex -rtc 3283Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3284UTC or local time, respectively. @code{localtime} is required for correct date in 3285MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the 3286format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3287 3288By default the RTC is driven by the host system time. This allows using of the 3289RTC as accurate reference clock inside the guest, specifically if the host 3290time is smoothly following an accurate external reference clock, e.g. via NTP. 3291If you want to isolate the guest time from the host, you can set @option{clock} 3292to @code{rt} instead. To even prevent it from progressing during suspension, 3293you can set it to @code{vm}. 3294 3295Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3296specifically with Windows' ACPI HAL. This option will try to figure out how 3297many timer interrupts were not processed by the Windows guest and will 3298re-inject them. 3299ETEXI 3300 3301DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3302 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>]\n" \ 3303 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3304 " instruction, enable aligning the host and virtual clocks\n" \ 3305 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3306STEXI 3307@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename}] 3308@findex -icount 3309Enable virtual instruction counter. The virtual cpu will execute one 3310instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3311then the virtual cpu speed will be automatically adjusted to keep virtual 3312time within a few seconds of real time. 3313 3314When the virtual cpu is sleeping, the virtual time will advance at default 3315speed unless @option{sleep=on|off} is specified. 3316With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3317instantly whenever the virtual cpu goes to sleep mode and will not advance 3318if no timer is enabled. This behavior give deterministic execution times from 3319the guest point of view. 3320 3321Note that while this option can give deterministic behavior, it does not 3322provide cycle accurate emulation. Modern CPUs contain superscalar out of 3323order cores with complex cache hierarchies. The number of instructions 3324executed often has little or no correlation with actual performance. 3325 3326@option{align=on} will activate the delay algorithm which will try 3327to synchronise the host clock and the virtual clock. The goal is to 3328have a guest running at the real frequency imposed by the shift option. 3329Whenever the guest clock is behind the host clock and if 3330@option{align=on} is specified then we print a message to the user 3331to inform about the delay. 3332Currently this option does not work when @option{shift} is @code{auto}. 3333Note: The sync algorithm will work for those shift values for which 3334the guest clock runs ahead of the host clock. Typically this happens 3335when the shift value is high (how high depends on the host machine). 3336 3337When @option{rr} option is specified deterministic record/replay is enabled. 3338Replay log is written into @var{filename} file in record mode and 3339read from this file in replay mode. 3340ETEXI 3341 3342DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3343 "-watchdog model\n" \ 3344 " enable virtual hardware watchdog [default=none]\n", 3345 QEMU_ARCH_ALL) 3346STEXI 3347@item -watchdog @var{model} 3348@findex -watchdog 3349Create a virtual hardware watchdog device. Once enabled (by a guest 3350action), the watchdog must be periodically polled by an agent inside 3351the guest or else the guest will be restarted. Choose a model for 3352which your guest has drivers. 3353 3354The @var{model} is the model of hardware watchdog to emulate. Use 3355@code{-watchdog help} to list available hardware models. Only one 3356watchdog can be enabled for a guest. 3357 3358The following models may be available: 3359@table @option 3360@item ib700 3361iBASE 700 is a very simple ISA watchdog with a single timer. 3362@item i6300esb 3363Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3364dual-timer watchdog. 3365@item diag288 3366A virtual watchdog for s390x backed by the diagnose 288 hypercall 3367(currently KVM only). 3368@end table 3369ETEXI 3370 3371DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3372 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \ 3373 " action when watchdog fires [default=reset]\n", 3374 QEMU_ARCH_ALL) 3375STEXI 3376@item -watchdog-action @var{action} 3377@findex -watchdog-action 3378 3379The @var{action} controls what QEMU will do when the watchdog timer 3380expires. 3381The default is 3382@code{reset} (forcefully reset the guest). 3383Other possible actions are: 3384@code{shutdown} (attempt to gracefully shutdown the guest), 3385@code{poweroff} (forcefully poweroff the guest), 3386@code{pause} (pause the guest), 3387@code{debug} (print a debug message and continue), or 3388@code{none} (do nothing). 3389 3390Note that the @code{shutdown} action requires that the guest responds 3391to ACPI signals, which it may not be able to do in the sort of 3392situations where the watchdog would have expired, and thus 3393@code{-watchdog-action shutdown} is not recommended for production use. 3394 3395Examples: 3396 3397@table @code 3398@item -watchdog i6300esb -watchdog-action pause 3399@itemx -watchdog ib700 3400@end table 3401ETEXI 3402 3403DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3404 "-echr chr set terminal escape character instead of ctrl-a\n", 3405 QEMU_ARCH_ALL) 3406STEXI 3407 3408@item -echr @var{numeric_ascii_value} 3409@findex -echr 3410Change the escape character used for switching to the monitor when using 3411monitor and serial sharing. The default is @code{0x01} when using the 3412@code{-nographic} option. @code{0x01} is equal to pressing 3413@code{Control-a}. You can select a different character from the ascii 3414control keys where 1 through 26 map to Control-a through Control-z. For 3415instance you could use the either of the following to change the escape 3416character to Control-t. 3417@table @code 3418@item -echr 0x14 3419@itemx -echr 20 3420@end table 3421ETEXI 3422 3423DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \ 3424 "-virtioconsole c\n" \ 3425 " set virtio console\n", QEMU_ARCH_ALL) 3426STEXI 3427@item -virtioconsole @var{c} 3428@findex -virtioconsole 3429Set virtio console. 3430 3431This option is maintained for backward compatibility. 3432 3433Please use @code{-device virtconsole} for the new way of invocation. 3434ETEXI 3435 3436DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3437 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3438STEXI 3439@item -show-cursor 3440@findex -show-cursor 3441Show cursor. 3442ETEXI 3443 3444DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3445 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3446STEXI 3447@item -tb-size @var{n} 3448@findex -tb-size 3449Set TB size. 3450ETEXI 3451 3452DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3453 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3454 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3455 "-incoming unix:socketpath\n" \ 3456 " prepare for incoming migration, listen on\n" \ 3457 " specified protocol and socket address\n" \ 3458 "-incoming fd:fd\n" \ 3459 "-incoming exec:cmdline\n" \ 3460 " accept incoming migration on given file descriptor\n" \ 3461 " or from given external command\n" \ 3462 "-incoming defer\n" \ 3463 " wait for the URI to be specified via migrate_incoming\n", 3464 QEMU_ARCH_ALL) 3465STEXI 3466@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3467@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3468@findex -incoming 3469Prepare for incoming migration, listen on a given tcp port. 3470 3471@item -incoming unix:@var{socketpath} 3472Prepare for incoming migration, listen on a given unix socket. 3473 3474@item -incoming fd:@var{fd} 3475Accept incoming migration from a given filedescriptor. 3476 3477@item -incoming exec:@var{cmdline} 3478Accept incoming migration as an output from specified external command. 3479 3480@item -incoming defer 3481Wait for the URI to be specified via migrate_incoming. The monitor can 3482be used to change settings (such as migration parameters) prior to issuing 3483the migrate_incoming to allow the migration to begin. 3484ETEXI 3485 3486DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3487 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3488STEXI 3489@item -nodefaults 3490@findex -nodefaults 3491Don't create default devices. Normally, QEMU sets the default devices like serial 3492port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3493CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3494default devices. 3495ETEXI 3496 3497#ifndef _WIN32 3498DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3499 "-chroot dir chroot to dir just before starting the VM\n", 3500 QEMU_ARCH_ALL) 3501#endif 3502STEXI 3503@item -chroot @var{dir} 3504@findex -chroot 3505Immediately before starting guest execution, chroot to the specified 3506directory. Especially useful in combination with -runas. 3507ETEXI 3508 3509#ifndef _WIN32 3510DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3511 "-runas user change to user id user just before starting the VM\n", 3512 QEMU_ARCH_ALL) 3513#endif 3514STEXI 3515@item -runas @var{user} 3516@findex -runas 3517Immediately before starting guest execution, drop root privileges, switching 3518to the specified user. 3519ETEXI 3520 3521DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 3522 "-prom-env variable=value\n" 3523 " set OpenBIOS nvram variables\n", 3524 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 3525STEXI 3526@item -prom-env @var{variable}=@var{value} 3527@findex -prom-env 3528Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 3529ETEXI 3530DEF("semihosting", 0, QEMU_OPTION_semihosting, 3531 "-semihosting semihosting mode\n", 3532 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3533 QEMU_ARCH_MIPS) 3534STEXI 3535@item -semihosting 3536@findex -semihosting 3537Enable semihosting mode (ARM, M68K, Xtensa, MIPS only). 3538ETEXI 3539DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 3540 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \ 3541 " semihosting configuration\n", 3542QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3543QEMU_ARCH_MIPS) 3544STEXI 3545@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]] 3546@findex -semihosting-config 3547Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only). 3548@table @option 3549@item target=@code{native|gdb|auto} 3550Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 3551or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 3552during debug sessions and @code{native} otherwise. 3553@item arg=@var{str1},arg=@var{str2},... 3554Allows the user to pass input arguments, and can be used multiple times to build 3555up a list. The old-style @code{-kernel}/@code{-append} method of passing a 3556command line is still supported for backward compatibility. If both the 3557@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 3558specified, the former is passed to semihosting as it always takes precedence. 3559@end table 3560ETEXI 3561DEF("old-param", 0, QEMU_OPTION_old_param, 3562 "-old-param old param mode\n", QEMU_ARCH_ARM) 3563STEXI 3564@item -old-param 3565@findex -old-param (ARM) 3566Old param mode (ARM only). 3567ETEXI 3568 3569DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 3570 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n", 3571 QEMU_ARCH_ALL) 3572STEXI 3573@item -sandbox @var{arg} 3574@findex -sandbox 3575Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 3576disable it. The default is 'off'. 3577ETEXI 3578 3579DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 3580 "-readconfig <file>\n", QEMU_ARCH_ALL) 3581STEXI 3582@item -readconfig @var{file} 3583@findex -readconfig 3584Read device configuration from @var{file}. This approach is useful when you want to spawn 3585QEMU process with many command line options but you don't want to exceed the command line 3586character limit. 3587ETEXI 3588DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 3589 "-writeconfig <file>\n" 3590 " read/write config file\n", QEMU_ARCH_ALL) 3591STEXI 3592@item -writeconfig @var{file} 3593@findex -writeconfig 3594Write device configuration to @var{file}. The @var{file} can be either filename to save 3595command line and device configuration into file or dash @code{-}) character to print the 3596output to stdout. This can be later used as input file for @code{-readconfig} option. 3597ETEXI 3598DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, 3599 "-nodefconfig\n" 3600 " do not load default config files at startup\n", 3601 QEMU_ARCH_ALL) 3602STEXI 3603@item -nodefconfig 3604@findex -nodefconfig 3605Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup. 3606The @code{-nodefconfig} option will prevent QEMU from loading any of those config files. 3607ETEXI 3608DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 3609 "-no-user-config\n" 3610 " do not load user-provided config files at startup\n", 3611 QEMU_ARCH_ALL) 3612STEXI 3613@item -no-user-config 3614@findex -no-user-config 3615The @code{-no-user-config} option makes QEMU not load any of the user-provided 3616config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config 3617files from @var{datadir}. 3618ETEXI 3619DEF("trace", HAS_ARG, QEMU_OPTION_trace, 3620 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 3621 " specify tracing options\n", 3622 QEMU_ARCH_ALL) 3623STEXI 3624HXCOMM This line is not accurate, as some sub-options are backend-specific but 3625HXCOMM HX does not support conditional compilation of text. 3626@item -trace [events=@var{file}][,file=@var{file}] 3627@findex -trace 3628 3629Specify tracing options. 3630 3631@table @option 3632@item [enable=]@var{pattern} 3633Immediately enable events matching @var{pattern}. 3634The file must contain one event name (as listed in the @file{trace-events} file) 3635per line; globbing patterns are accepted too. This option is only 3636available if QEMU has been compiled with the @var{simple}, @var{stderr} 3637or @var{ftrace} tracing backend. To specify multiple events or patterns, 3638specify the @option{-trace} option multiple times. 3639 3640Use @code{-trace help} to print a list of names of trace points. 3641 3642@item events=@var{file} 3643Immediately enable events listed in @var{file}. 3644The file must contain one event name (as listed in the @file{trace-events} file) 3645per line; globbing patterns are accepted too. This option is only 3646available if QEMU has been compiled with the @var{simple}, @var{stderr} or 3647@var{ftrace} tracing backend. 3648 3649@item file=@var{file} 3650Log output traces to @var{file}. 3651This option is only available if QEMU has been compiled with 3652the @var{simple} tracing backend. 3653@end table 3654ETEXI 3655 3656HXCOMM Internal use 3657DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 3658DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 3659 3660#ifdef __linux__ 3661DEF("enable-fips", 0, QEMU_OPTION_enablefips, 3662 "-enable-fips enable FIPS 140-2 compliance\n", 3663 QEMU_ARCH_ALL) 3664#endif 3665STEXI 3666@item -enable-fips 3667@findex -enable-fips 3668Enable FIPS 140-2 compliance mode. 3669ETEXI 3670 3671HXCOMM Deprecated by -machine accel=tcg property 3672DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 3673 3674HXCOMM Deprecated by kvm-pit driver properties 3675DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection, 3676 "", QEMU_ARCH_I386) 3677 3678HXCOMM Deprecated (ignored) 3679DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386) 3680 3681HXCOMM Deprecated by -machine kernel_irqchip=on|off property 3682DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386) 3683 3684HXCOMM Deprecated (ignored) 3685DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL) 3686 3687DEF("msg", HAS_ARG, QEMU_OPTION_msg, 3688 "-msg timestamp[=on|off]\n" 3689 " change the format of messages\n" 3690 " on|off controls leading timestamps (default:on)\n", 3691 QEMU_ARCH_ALL) 3692STEXI 3693@item -msg timestamp[=on|off] 3694@findex -msg 3695prepend a timestamp to each log message.(default:on) 3696ETEXI 3697 3698DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 3699 "-dump-vmstate <file>\n" 3700 " Output vmstate information in JSON format to file.\n" 3701 " Use the scripts/vmstate-static-checker.py file to\n" 3702 " check for possible regressions in migration code\n" 3703 " by comparing two such vmstate dumps.\n", 3704 QEMU_ARCH_ALL) 3705STEXI 3706@item -dump-vmstate @var{file} 3707@findex -dump-vmstate 3708Dump json-encoded vmstate information for current machine type to file 3709in @var{file} 3710ETEXI 3711 3712DEFHEADING(Generic object creation) 3713 3714DEF("object", HAS_ARG, QEMU_OPTION_object, 3715 "-object TYPENAME[,PROP1=VALUE1,...]\n" 3716 " create a new object of type TYPENAME setting properties\n" 3717 " in the order they are specified. Note that the 'id'\n" 3718 " property must be set. These objects are placed in the\n" 3719 " '/objects' path.\n", 3720 QEMU_ARCH_ALL) 3721STEXI 3722@item -object @var{typename}[,@var{prop1}=@var{value1},...] 3723@findex -object 3724Create a new object of type @var{typename} setting properties 3725in the order they are specified. Note that the 'id' 3726property must be set. These objects are placed in the 3727'/objects' path. 3728 3729@table @option 3730 3731@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off} 3732 3733Creates a memory file backend object, which can be used to back 3734the guest RAM with huge pages. The @option{id} parameter is a 3735unique ID that will be used to reference this memory region 3736when configuring the @option{-numa} argument. The @option{size} 3737option provides the size of the memory region, and accepts 3738common suffixes, eg @option{500M}. The @option{mem-path} provides 3739the path to either a shared memory or huge page filesystem mount. 3740The @option{share} boolean option determines whether the memory 3741region is marked as private to QEMU, or shared. The latter allows 3742a co-operating external process to access the QEMU memory region. 3743 3744@item -object rng-random,id=@var{id},filename=@var{/dev/random} 3745 3746Creates a random number generator backend which obtains entropy from 3747a device on the host. The @option{id} parameter is a unique ID that 3748will be used to reference this entropy backend from the @option{virtio-rng} 3749device. The @option{filename} parameter specifies which file to obtain 3750entropy from and if omitted defaults to @option{/dev/random}. 3751 3752@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 3753 3754Creates a random number generator backend which obtains entropy from 3755an external daemon running on the host. The @option{id} parameter is 3756a unique ID that will be used to reference this entropy backend from 3757the @option{virtio-rng} device. The @option{chardev} parameter is 3758the unique ID of a character device backend that provides the connection 3759to the RNG daemon. 3760 3761@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 3762 3763Creates a TLS anonymous credentials object, which can be used to provide 3764TLS support on network backends. The @option{id} parameter is a unique 3765ID which network backends will use to access the credentials. The 3766@option{endpoint} is either @option{server} or @option{client} depending 3767on whether the QEMU network backend that uses the credentials will be 3768acting as a client or as a server. If @option{verify-peer} is enabled 3769(the default) then once the handshake is completed, the peer credentials 3770will be verified, though this is a no-op for anonymous credentials. 3771 3772The @var{dir} parameter tells QEMU where to find the credential 3773files. For server endpoints, this directory may contain a file 3774@var{dh-params.pem} providing diffie-hellman parameters to use 3775for the TLS server. If the file is missing, QEMU will generate 3776a set of DH parameters at startup. This is a computationally 3777expensive operation that consumes random pool entropy, so it is 3778recommended that a persistent set of parameters be generated 3779upfront and saved. 3780 3781@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} 3782 3783Creates a TLS anonymous credentials object, which can be used to provide 3784TLS support on network backends. The @option{id} parameter is a unique 3785ID which network backends will use to access the credentials. The 3786@option{endpoint} is either @option{server} or @option{client} depending 3787on whether the QEMU network backend that uses the credentials will be 3788acting as a client or as a server. If @option{verify-peer} is enabled 3789(the default) then once the handshake is completed, the peer credentials 3790will be verified. With x509 certificates, this implies that the clients 3791must be provided with valid client certificates too. 3792 3793The @var{dir} parameter tells QEMU where to find the credential 3794files. For server endpoints, this directory may contain a file 3795@var{dh-params.pem} providing diffie-hellman parameters to use 3796for the TLS server. If the file is missing, QEMU will generate 3797a set of DH parameters at startup. This is a computationally 3798expensive operation that consumes random pool entropy, so it is 3799recommended that a persistent set of parameters be generated 3800upfront and saved. 3801 3802For x509 certificate credentials the directory will contain further files 3803providing the x509 certificates. The certificates must be stored 3804in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 3805@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 3806@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 3807 3808For the @var{server-key.pem} and @var{client-key.pem} files which 3809contain sensitive private keys, it is possible to use an encrypted 3810version by providing the @var{passwordid} parameter. This provides 3811the ID of a previously created @code{secret} object containing the 3812password for decryption. 3813 3814@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 3815 3816Interval @var{t} can't be 0, this filter batches the packet delivery: all 3817packets arriving in a given interval on netdev @var{netdevid} are delayed 3818until the end of the interval. Interval is in microseconds. 3819@option{status} is optional that indicate whether the netfilter is 3820on (enabled) or off (disabled), the default status for netfilter will be 'on'. 3821 3822queue @var{all|rx|tx} is an option that can be applied to any netfilter. 3823 3824@option{all}: the filter is attached both to the receive and the transmit 3825 queue of the netdev (default). 3826 3827@option{rx}: the filter is attached to the receive queue of the netdev, 3828 where it will receive packets sent to the netdev. 3829 3830@option{tx}: the filter is attached to the transmit queue of the netdev, 3831 where it will receive packets sent by the netdev. 3832 3833@item -object filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}] 3834 3835Dump the network traffic on netdev @var{dev} to the file specified by 3836@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 3837The file format is libpcap, so it can be analyzed with tools such as tcpdump 3838or Wireshark. 3839 3840@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 3841@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 3842 3843Defines a secret to store a password, encryption key, or some other sensitive 3844data. The sensitive data can either be passed directly via the @var{data} 3845parameter, or indirectly via the @var{file} parameter. Using the @var{data} 3846parameter is insecure unless the sensitive data is encrypted. 3847 3848The sensitive data can be provided in raw format (the default), or base64. 3849When encoded as JSON, the raw format only supports valid UTF-8 characters, 3850so base64 is recommended for sending binary data. QEMU will convert from 3851which ever format is provided to the format it needs internally. eg, an 3852RBD password can be provided in raw format, even though it will be base64 3853encoded when passed onto the RBD sever. 3854 3855For added protection, it is possible to encrypt the data associated with 3856a secret using the AES-256-CBC cipher. Use of encryption is indicated 3857by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 3858parameter provides the ID of a previously defined secret that contains 3859the AES-256 decryption key. This key should be 32-bytes long and be 3860base64 encoded. The @var{iv} parameter provides the random initialization 3861vector used for encryption of this particular secret and should be a 3862base64 encrypted string of the 32-byte IV. 3863 3864The simplest (insecure) usage is to provide the secret inline 3865 3866@example 3867 3868 # $QEMU -object secret,id=sec0,data=letmein,format=raw 3869 3870@end example 3871 3872The simplest secure usage is to provide the secret via a file 3873 3874 # echo -n "letmein" > mypasswd.txt 3875 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw 3876 3877For greater security, AES-256-CBC should be used. To illustrate usage, 3878consider the openssl command line tool which can encrypt the data. Note 3879that when encrypting, the plaintext must be padded to the cipher block 3880size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 3881 3882First a master key needs to be created in base64 encoding: 3883 3884@example 3885 # openssl rand -base64 32 > key.b64 3886 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 3887@end example 3888 3889Each secret to be encrypted needs to have a random initialization vector 3890generated. These do not need to be kept secret 3891 3892@example 3893 # openssl rand -base64 16 > iv.b64 3894 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 3895@end example 3896 3897The secret to be defined can now be encrypted, in this case we're 3898telling openssl to base64 encode the result, but it could be left 3899as raw bytes if desired. 3900 3901@example 3902 # SECRET=$(echo -n "letmein" | 3903 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 3904@end example 3905 3906When launching QEMU, create a master secret pointing to @code{key.b64} 3907and specify that to be used to decrypt the user password. Pass the 3908contents of @code{iv.b64} to the second secret 3909 3910@example 3911 # $QEMU \ 3912 -object secret,id=secmaster0,format=base64,file=key.b64 \ 3913 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 3914 data=$SECRET,iv=$(<iv.b64) 3915@end example 3916 3917@end table 3918 3919ETEXI 3920 3921 3922HXCOMM This is the last statement. Insert new options before this line! 3923STEXI 3924@end table 3925ETEXI 3926
