1HXCOMM Use DEFHEADING() to define headings in both help text and texi 2HXCOMM Text between STEXI and ETEXI are copied to texi version and 3HXCOMM discarded from C version 4HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to 5HXCOMM construct option structures, enums and help message for specified 6HXCOMM architectures. 7HXCOMM HXCOMM can be used for comments, discarded from both texi and C 8 9DEFHEADING(Standard options) 10STEXI 11@table @option 12ETEXI 13 14DEF("help", 0, QEMU_OPTION_h, 15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL) 16STEXI 17@item -h 18@findex -h 19Display help and exit 20ETEXI 21 22DEF("version", 0, QEMU_OPTION_version, 23 "-version display version information and exit\n", QEMU_ARCH_ALL) 24STEXI 25@item -version 26@findex -version 27Display version information and exit 28ETEXI 29 30DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ 31 "-machine [type=]name[,prop[=value][,...]]\n" 32 " selects emulated machine ('-machine help' for list)\n" 33 " property accel=accel1[:accel2[:...]] selects accelerator\n" 34 " supported accelerators are kvm, xen, hax or tcg (default: tcg)\n" 35 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n" 36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 37 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n" 38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 39 " mem-merge=on|off controls memory merge support (default: on)\n" 40 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n" 41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 44 " nvdimm=on|off controls NVDIMM support (default=off)\n" 45 " enforce-config-section=on|off enforce configuration section migration (default=off)\n" 46 " s390-squash-mcss=on|off controls support for squashing into default css (default=off)\n", 47 QEMU_ARCH_ALL) 48STEXI 49@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 50@findex -machine 51Select the emulated machine by @var{name}. Use @code{-machine help} to list 52available machines. 53 54For architectures which aim to support live migration compatibility 55across releases, each release will introduce a new versioned machine 56type. For example, the 2.8.0 release introduced machine types 57``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures. 58 59To allow live migration of guests from QEMU version 2.8.0, to QEMU 60version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8'' 61and ``pc-q35-2.8'' machines too. To allow users live migrating VMs 62to skip multiple intermediate releases when upgrading, new releases 63of QEMU will support machine types from many previous versions. 64 65Supported machine properties are: 66@table @option 67@item accel=@var{accels1}[:@var{accels2}[:...]] 68This is used to enable an accelerator. Depending on the target architecture, 69kvm, xen, hax or tcg can be available. By default, tcg is used. If there is 70more than one accelerator specified, the next one is used if the previous one 71fails to initialize. 72@item kernel_irqchip=on|off 73Controls in-kernel irqchip support for the chosen accelerator when available. 74@item gfx_passthru=on|off 75Enables IGD GFX passthrough support for the chosen machine when available. 76@item vmport=on|off|auto 77Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 78value based on accel. For accel=xen the default is off otherwise the default 79is on. 80@item kvm_shadow_mem=size 81Defines the size of the KVM shadow MMU. 82@item dump-guest-core=on|off 83Include guest memory in a core dump. The default is on. 84@item mem-merge=on|off 85Enables or disables memory merge support. This feature, when supported by 86the host, de-duplicates identical memory pages among VMs instances 87(enabled by default). 88@item aes-key-wrap=on|off 89Enables or disables AES key wrapping support on s390-ccw hosts. This feature 90controls whether AES wrapping keys will be created to allow 91execution of AES cryptographic functions. The default is on. 92@item dea-key-wrap=on|off 93Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 94controls whether DEA wrapping keys will be created to allow 95execution of DEA cryptographic functions. The default is on. 96@item nvdimm=on|off 97Enables or disables NVDIMM support. The default is off. 98@item s390-squash-mcss=on|off 99Enables or disables squashing subchannels into the default css. 100The default is off. 101@item enforce-config-section=on|off 102If @option{enforce-config-section} is set to @var{on}, force migration 103code to send configuration section even if the machine-type sets the 104@option{migration.send-configuration} property to @var{off}. 105NOTE: this parameter is deprecated. Please use @option{-global} 106@option{migration.send-configuration}=@var{on|off} instead. 107@end table 108ETEXI 109 110HXCOMM Deprecated by -machine 111DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 112 113DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 114 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 115STEXI 116@item -cpu @var{model} 117@findex -cpu 118Select CPU model (@code{-cpu help} for list and additional feature selection) 119ETEXI 120 121DEF("accel", HAS_ARG, QEMU_OPTION_accel, 122 "-accel [accel=]accelerator[,thread=single|multi]\n" 123 " select accelerator (kvm, xen, hax or tcg; use 'help' for a list)\n" 124 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 125STEXI 126@item -accel @var{name}[,prop=@var{value}[,...]] 127@findex -accel 128This is used to enable an accelerator. Depending on the target architecture, 129kvm, xen, hax or tcg can be available. By default, tcg is used. If there is 130more than one accelerator specified, the next one is used if the previous one 131fails to initialize. 132@table @option 133@item thread=single|multi 134Controls number of TCG threads. When the TCG is multi-threaded there will be one 135thread per vCPU therefor taking advantage of additional host cores. The default 136is to enable multi-threading where both the back-end and front-ends support it and 137no incompatible TCG features have been enabled (e.g. icount/replay). 138@end table 139ETEXI 140 141DEF("smp", HAS_ARG, QEMU_OPTION_smp, 142 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n" 143 " set the number of CPUs to 'n' [default=1]\n" 144 " maxcpus= maximum number of total cpus, including\n" 145 " offline CPUs for hotplug, etc\n" 146 " cores= number of CPU cores on one socket\n" 147 " threads= number of threads on one CPU core\n" 148 " sockets= number of discrete sockets in the system\n", 149 QEMU_ARCH_ALL) 150STEXI 151@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 152@findex -smp 153Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 154CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 155to 4. 156For the PC target, the number of @var{cores} per socket, the number 157of @var{threads} per cores and the total number of @var{sockets} can be 158specified. Missing values will be computed. If any on the three values is 159given, the total number of CPUs @var{n} can be omitted. @var{maxcpus} 160specifies the maximum number of hotpluggable CPUs. 161ETEXI 162 163DEF("numa", HAS_ARG, QEMU_OPTION_numa, 164 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 165 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 166 "-numa dist,src=source,dst=destination,val=distance\n", QEMU_ARCH_ALL) 167STEXI 168@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 169@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 170@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 171@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 172@findex -numa 173Define a NUMA node and assign RAM and VCPUs to it. 174Set the NUMA distance from a source node to a destination node. 175 176Legacy VCPU assignment uses @samp{cpus} option where 177@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 178@samp{cpus} option represent a contiguous range of CPU indexes 179(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 180set of VCPUs can be represented by providing multiple @samp{cpus} 181options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 182split between them. 183 184For example, the following option assigns VCPUs 0, 1, 2 and 5 to 185a NUMA node: 186@example 187-numa node,cpus=0-2,cpus=5 188@end example 189 190@samp{cpu} option is a new alternative to @samp{cpus} option 191which uses @samp{socket-id|core-id|thread-id} properties to assign 192CPU objects to a @var{node} using topology layout properties of CPU. 193The set of properties is machine specific, and depends on used 194machine type/@samp{smp} options. It could be queried with 195@samp{hotpluggable-cpus} monitor command. 196@samp{node-id} property specifies @var{node} to which CPU object 197will be assigned, it's required for @var{node} to be declared 198with @samp{node} option before it's used with @samp{cpu} option. 199 200For example: 201@example 202-M pc \ 203-smp 1,sockets=2,maxcpus=2 \ 204-numa node,nodeid=0 -numa node,nodeid=1 \ 205-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 206@end example 207 208@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 209assigns RAM from a given memory backend device to a node. If 210@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 211split equally between them. 212 213@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 214if one node uses @samp{memdev}, all of them have to use it. 215 216@var{source} and @var{destination} are NUMA node IDs. 217@var{distance} is the NUMA distance from @var{source} to @var{destination}. 218The distance from a node to itself is always 10. If any pair of nodes is 219given a distance, then all pairs must be given distances. Although, when 220distances are only given in one direction for each pair of nodes, then 221the distances in the opposite directions are assumed to be the same. If, 222however, an asymmetrical pair of distances is given for even one node 223pair, then all node pairs must be provided distance values for both 224directions, even when they are symmetrical. When a node is unreachable 225from another node, set the pair's distance to 255. 226 227Note that the -@option{numa} option doesn't allocate any of the 228specified resources, it just assigns existing resources to NUMA 229nodes. This means that one still has to use the @option{-m}, 230@option{-smp} options to allocate RAM and VCPUs respectively. 231 232ETEXI 233 234DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 235 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 236 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 237STEXI 238@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 239@findex -add-fd 240 241Add a file descriptor to an fd set. Valid options are: 242 243@table @option 244@item fd=@var{fd} 245This option defines the file descriptor of which a duplicate is added to fd set. 246The file descriptor cannot be stdin, stdout, or stderr. 247@item set=@var{set} 248This option defines the ID of the fd set to add the file descriptor to. 249@item opaque=@var{opaque} 250This option defines a free-form string that can be used to describe @var{fd}. 251@end table 252 253You can open an image using pre-opened file descriptors from an fd set: 254@example 255qemu-system-i386 256-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 257-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 258-drive file=/dev/fdset/2,index=0,media=disk 259@end example 260ETEXI 261 262DEF("set", HAS_ARG, QEMU_OPTION_set, 263 "-set group.id.arg=value\n" 264 " set <arg> parameter for item <id> of type <group>\n" 265 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 266STEXI 267@item -set @var{group}.@var{id}.@var{arg}=@var{value} 268@findex -set 269Set parameter @var{arg} for item @var{id} of type @var{group} 270ETEXI 271 272DEF("global", HAS_ARG, QEMU_OPTION_global, 273 "-global driver.property=value\n" 274 "-global driver=driver,property=property,value=value\n" 275 " set a global default for a driver property\n", 276 QEMU_ARCH_ALL) 277STEXI 278@item -global @var{driver}.@var{prop}=@var{value} 279@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 280@findex -global 281Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 282 283@example 284qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img 285@end example 286 287In particular, you can use this to set driver properties for devices which are 288created automatically by the machine model. To create a device which is not 289created automatically and set properties on it, use -@option{device}. 290 291-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 292driver=@var{driver},property=@var{prop},value=@var{value}. The 293longhand syntax works even when @var{driver} contains a dot. 294ETEXI 295 296DEF("boot", HAS_ARG, QEMU_OPTION_boot, 297 "-boot [order=drives][,once=drives][,menu=on|off]\n" 298 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 299 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 300 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 301 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 302 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 303 QEMU_ARCH_ALL) 304STEXI 305@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] 306@findex -boot 307Specify boot order @var{drives} as a string of drive letters. Valid 308drive letters depend on the target architecture. The x86 PC uses: a, b 309(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 310from network adapter 1-4), hard disk boot is the default. To apply a 311particular boot order only on the first startup, specify it via 312@option{once}. Note that the @option{order} or @option{once} parameter 313should not be used together with the @option{bootindex} property of 314devices, since the firmware implementations normally do not support both 315at the same time. 316 317Interactive boot menus/prompts can be enabled via @option{menu=on} as far 318as firmware/BIOS supports them. The default is non-interactive boot. 319 320A splash picture could be passed to bios, enabling user to show it as logo, 321when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 322supports them. Currently Seabios for X86 system support it. 323limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 324format(true color). The resolution should be supported by the SVGA mode, so 325the recommended is 320x240, 640x480, 800x640. 326 327A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 328when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 329reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 330system support it. 331 332Do strict boot via @option{strict=on} as far as firmware/BIOS 333supports it. This only effects when boot priority is changed by 334bootindex options. The default is non-strict boot. 335 336@example 337# try to boot from network first, then from hard disk 338qemu-system-i386 -boot order=nc 339# boot from CD-ROM first, switch back to default order after reboot 340qemu-system-i386 -boot once=d 341# boot with a splash picture for 5 seconds. 342qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000 343@end example 344 345Note: The legacy format '-boot @var{drives}' is still supported but its 346use is discouraged as it may be removed from future versions. 347ETEXI 348 349DEF("m", HAS_ARG, QEMU_OPTION_m, 350 "-m [size=]megs[,slots=n,maxmem=size]\n" 351 " configure guest RAM\n" 352 " size: initial amount of guest memory\n" 353 " slots: number of hotplug slots (default: none)\n" 354 " maxmem: maximum amount of guest memory (default: none)\n" 355 "NOTE: Some architectures might enforce a specific granularity\n", 356 QEMU_ARCH_ALL) 357STEXI 358@item -m [size=]@var{megs}[,slots=n,maxmem=size] 359@findex -m 360Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 361Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 362megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 363could be used to set amount of hotpluggable memory slots and maximum amount of 364memory. Note that @var{maxmem} must be aligned to the page size. 365 366For example, the following command-line sets the guest startup RAM size to 3671GB, creates 3 slots to hotplug additional memory and sets the maximum 368memory the guest can reach to 4GB: 369 370@example 371qemu-system-x86_64 -m 1G,slots=3,maxmem=4G 372@end example 373 374If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 375be enabled and the guest startup RAM will never increase. 376ETEXI 377 378DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 379 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 380STEXI 381@item -mem-path @var{path} 382@findex -mem-path 383Allocate guest RAM from a temporarily created file in @var{path}. 384ETEXI 385 386DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 387 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 388 QEMU_ARCH_ALL) 389STEXI 390@item -mem-prealloc 391@findex -mem-prealloc 392Preallocate memory when using -mem-path. 393ETEXI 394 395DEF("k", HAS_ARG, QEMU_OPTION_k, 396 "-k language use keyboard layout (for example 'fr' for French)\n", 397 QEMU_ARCH_ALL) 398STEXI 399@item -k @var{language} 400@findex -k 401Use keyboard layout @var{language} (for example @code{fr} for 402French). This option is only needed where it is not easy to get raw PC 403keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 404display). You don't normally need to use it on PC/Linux or PC/Windows 405hosts. 406 407The available layouts are: 408@example 409ar de-ch es fo fr-ca hu ja mk no pt-br sv 410da en-gb et fr fr-ch is lt nl pl ru th 411de en-us fi fr-be hr it lv nl-be pt sl tr 412@end example 413 414The default is @code{en-us}. 415ETEXI 416 417 418DEF("audio-help", 0, QEMU_OPTION_audio_help, 419 "-audio-help print list of audio drivers and their options\n", 420 QEMU_ARCH_ALL) 421STEXI 422@item -audio-help 423@findex -audio-help 424Will show the audio subsystem help: list of drivers, tunable 425parameters. 426ETEXI 427 428DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 429 "-soundhw c1,... enable audio support\n" 430 " and only specified sound cards (comma separated list)\n" 431 " use '-soundhw help' to get the list of supported cards\n" 432 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 433STEXI 434@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 435@findex -soundhw 436Enable audio and selected sound hardware. Use 'help' to print all 437available sound hardware. 438 439@example 440qemu-system-i386 -soundhw sb16,adlib disk.img 441qemu-system-i386 -soundhw es1370 disk.img 442qemu-system-i386 -soundhw ac97 disk.img 443qemu-system-i386 -soundhw hda disk.img 444qemu-system-i386 -soundhw all disk.img 445qemu-system-i386 -soundhw help 446@end example 447 448Note that Linux's i810_audio OSS kernel (for AC97) module might 449require manually specifying clocking. 450 451@example 452modprobe i810_audio clocking=48000 453@end example 454ETEXI 455 456DEF("balloon", HAS_ARG, QEMU_OPTION_balloon, 457 "-balloon none disable balloon device\n" 458 "-balloon virtio[,addr=str]\n" 459 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL) 460STEXI 461@item -balloon none 462@findex -balloon 463Disable balloon device. 464@item -balloon virtio[,addr=@var{addr}] 465Enable virtio balloon device (default), optionally with PCI address 466@var{addr}. 467ETEXI 468 469DEF("device", HAS_ARG, QEMU_OPTION_device, 470 "-device driver[,prop[=value][,...]]\n" 471 " add device (based on driver)\n" 472 " prop=value,... sets driver properties\n" 473 " use '-device help' to print all possible drivers\n" 474 " use '-device driver,help' to print all possible properties\n", 475 QEMU_ARCH_ALL) 476STEXI 477@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 478@findex -device 479Add device @var{driver}. @var{prop}=@var{value} sets driver 480properties. Valid properties depend on the driver. To get help on 481possible drivers and properties, use @code{-device help} and 482@code{-device @var{driver},help}. 483 484Some drivers are: 485@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}] 486 487Add an IPMI BMC. This is a simulation of a hardware management 488interface processor that normally sits on a system. It provides 489a watchdog and the ability to reset and power control the system. 490You need to connect this to an IPMI interface to make it useful 491 492The IPMI slave address to use for the BMC. The default is 0x20. 493This address is the BMC's address on the I2C network of management 494controllers. If you don't know what this means, it is safe to ignore 495it. 496 497@table @option 498@item bmc=@var{id} 499The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 500@item slave_addr=@var{val} 501Define slave address to use for the BMC. The default is 0x20. 502@item sdrfile=@var{file} 503file containing raw Sensor Data Records (SDR) data. The default is none. 504@item fruareasize=@var{val} 505size of a Field Replaceable Unit (FRU) area. The default is 1024. 506@item frudatafile=@var{file} 507file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 508@end table 509 510@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 511 512Add a connection to an external IPMI BMC simulator. Instead of 513locally emulating the BMC like the above item, instead connect 514to an external entity that provides the IPMI services. 515 516A connection is made to an external BMC simulator. If you do this, it 517is strongly recommended that you use the "reconnect=" chardev option 518to reconnect to the simulator if the connection is lost. Note that if 519this is not used carefully, it can be a security issue, as the 520interface has the ability to send resets, NMIs, and power off the VM. 521It's best if QEMU makes a connection to an external simulator running 522on a secure port on localhost, so neither the simulator nor QEMU is 523exposed to any outside network. 524 525See the "lanserv/README.vm" file in the OpenIPMI library for more 526details on the external interface. 527 528@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 529 530Add a KCS IPMI interafce on the ISA bus. This also adds a 531corresponding ACPI and SMBIOS entries, if appropriate. 532 533@table @option 534@item bmc=@var{id} 535The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 536@item ioport=@var{val} 537Define the I/O address of the interface. The default is 0xca0 for KCS. 538@item irq=@var{val} 539Define the interrupt to use. The default is 5. To disable interrupts, 540set this to 0. 541@end table 542 543@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 544 545Like the KCS interface, but defines a BT interface. The default port is 5460xe4 and the default interrupt is 5. 547 548ETEXI 549 550DEF("name", HAS_ARG, QEMU_OPTION_name, 551 "-name string1[,process=string2][,debug-threads=on|off]\n" 552 " set the name of the guest\n" 553 " string1 sets the window title and string2 the process name (on Linux)\n" 554 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n" 555 " NOTE: The thread names are for debugging and not a stable API.\n", 556 QEMU_ARCH_ALL) 557STEXI 558@item -name @var{name} 559@findex -name 560Sets the @var{name} of the guest. 561This name will be displayed in the SDL window caption. 562The @var{name} will also be used for the VNC server. 563Also optionally set the top visible process name in Linux. 564Naming of individual threads can also be enabled on Linux to aid debugging. 565ETEXI 566 567DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 568 "-uuid %08x-%04x-%04x-%04x-%012x\n" 569 " specify machine UUID\n", QEMU_ARCH_ALL) 570STEXI 571@item -uuid @var{uuid} 572@findex -uuid 573Set system UUID. 574ETEXI 575 576STEXI 577@end table 578ETEXI 579DEFHEADING() 580 581DEFHEADING(Block device options) 582STEXI 583@table @option 584ETEXI 585 586DEF("fda", HAS_ARG, QEMU_OPTION_fda, 587 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 588DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 589STEXI 590@item -fda @var{file} 591@itemx -fdb @var{file} 592@findex -fda 593@findex -fdb 594Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 595ETEXI 596 597DEF("hda", HAS_ARG, QEMU_OPTION_hda, 598 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 599DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 600DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 601 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 602DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 603STEXI 604@item -hda @var{file} 605@itemx -hdb @var{file} 606@itemx -hdc @var{file} 607@itemx -hdd @var{file} 608@findex -hda 609@findex -hdb 610@findex -hdc 611@findex -hdd 612Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 613ETEXI 614 615DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 616 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 617 QEMU_ARCH_ALL) 618STEXI 619@item -cdrom @var{file} 620@findex -cdrom 621Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 622@option{-cdrom} at the same time). You can use the host CD-ROM by 623using @file{/dev/cdrom} as filename (@pxref{host_drives}). 624ETEXI 625 626DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 627 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 628 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 629 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n" 630 " [,driver specific parameters...]\n" 631 " configure a block backend\n", QEMU_ARCH_ALL) 632STEXI 633@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 634@findex -blockdev 635 636Define a new block driver node. Some of the options apply to all block drivers, 637other options are only accepted for a specific block driver. See below for a 638list of generic options and options for the most common block drivers. 639 640Options that expect a reference to another node (e.g. @code{file}) can be 641given in two ways. Either you specify the node name of an already existing node 642(file=@var{node-name}), or you define a new node inline, adding options 643for the referenced node after a dot (file.filename=@var{path},file.aio=native). 644 645A block driver node created with @option{-blockdev} can be used for a guest 646device by specifying its node name for the @code{drive} property in a 647@option{-device} argument that defines a block device. 648 649@table @option 650@item Valid options for any block driver node: 651 652@table @code 653@item driver 654Specifies the block driver to use for the given node. 655@item node-name 656This defines the name of the block driver node by which it will be referenced 657later. The name must be unique, i.e. it must not match the name of a different 658block driver node, or (if you use @option{-drive} as well) the ID of a drive. 659 660If no node name is specified, it is automatically generated. The generated node 661name is not intended to be predictable and changes between QEMU invocations. 662For the top level, an explicit node name must be specified. 663@item read-only 664Open the node read-only. Guest write attempts will fail. 665@item cache.direct 666The host page cache can be avoided with @option{cache.direct=on}. This will 667attempt to do disk IO directly to the guest's memory. QEMU may still perform an 668internal copy of the data. 669@item cache.no-flush 670In case you don't care about data integrity over host failures, you can use 671@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 672any data to the disk but can instead keep things in cache. If anything goes 673wrong, like your host losing power, the disk storage getting disconnected 674accidentally, etc. your image will most probably be rendered unusable. 675@item discard=@var{discard} 676@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 677whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 678ignored or passed to the filesystem. Some machine types may not support 679discard requests. 680@item detect-zeroes=@var{detect-zeroes} 681@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 682conversion of plain zero writes by the OS to driver specific optimized 683zero write commands. You may even choose "unmap" if @var{discard} is set 684to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 685@end table 686 687@item Driver-specific options for @code{file} 688 689This is the protocol-level block driver for accessing regular files. 690 691@table @code 692@item filename 693The path to the image file in the local filesystem 694@item aio 695Specifies the AIO backend (threads/native, default: threads) 696@end table 697Example: 698@example 699-blockdev driver=file,node-name=disk,filename=disk.img 700@end example 701 702@item Driver-specific options for @code{raw} 703 704This is the image format block driver for raw images. It is usually 705stacked on top of a protocol level block driver such as @code{file}. 706 707@table @code 708@item file 709Reference to or definition of the data source block driver node 710(e.g. a @code{file} driver node) 711@end table 712Example 1: 713@example 714-blockdev driver=file,node-name=disk_file,filename=disk.img 715-blockdev driver=raw,node-name=disk,file=disk_file 716@end example 717Example 2: 718@example 719-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 720@end example 721 722@item Driver-specific options for @code{qcow2} 723 724This is the image format block driver for qcow2 images. It is usually 725stacked on top of a protocol level block driver such as @code{file}. 726 727@table @code 728@item file 729Reference to or definition of the data source block driver node 730(e.g. a @code{file} driver node) 731 732@item backing 733Reference to or definition of the backing file block device (default is taken 734from the image file). It is allowed to pass an empty string here in order to 735disable the default backing file. 736 737@item lazy-refcounts 738Whether to enable the lazy refcounts feature (on/off; default is taken from the 739image file) 740 741@item cache-size 742The maximum total size of the L2 table and refcount block caches in bytes 743(default: 1048576 bytes or 8 clusters, whichever is larger) 744 745@item l2-cache-size 746The maximum size of the L2 table cache in bytes 747(default: 4/5 of the total cache size) 748 749@item refcount-cache-size 750The maximum size of the refcount block cache in bytes 751(default: 1/5 of the total cache size) 752 753@item cache-clean-interval 754Clean unused entries in the L2 and refcount caches. The interval is in seconds. 755The default value is 0 and it disables this feature. 756 757@item pass-discard-request 758Whether discard requests to the qcow2 device should be forwarded to the data 759source (on/off; default: on if discard=unmap is specified, off otherwise) 760 761@item pass-discard-snapshot 762Whether discard requests for the data source should be issued when a snapshot 763operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 764default: on) 765 766@item pass-discard-other 767Whether discard requests for the data source should be issued on other 768occasions where a cluster gets freed (on/off; default: off) 769 770@item overlap-check 771Which overlap checks to perform for writes to the image 772(none/constant/cached/all; default: cached). For details or finer 773granularity control refer to the QAPI documentation of @code{blockdev-add}. 774@end table 775 776Example 1: 777@example 778-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 779-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 780@end example 781Example 2: 782@example 783-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 784@end example 785 786@item Driver-specific options for other drivers 787Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 788 789@end table 790 791ETEXI 792 793DEF("drive", HAS_ARG, QEMU_OPTION_drive, 794 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 795 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n" 796 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 797 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n" 798 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 799 " [,readonly=on|off][,copy-on-read=on|off]\n" 800 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 801 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 802 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 803 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 804 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 805 " [[,iops_size=is]]\n" 806 " [[,group=g]]\n" 807 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 808STEXI 809@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 810@findex -drive 811 812Define a new drive. This includes creating a block driver node (the backend) as 813well as a guest device, and is mostly a shortcut for defining the corresponding 814@option{-blockdev} and @option{-device} options. 815 816@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 817addition, it knows the following options: 818 819@table @option 820@item file=@var{file} 821This option defines which disk image (@pxref{disk_images}) to use with 822this drive. If the filename contains comma, you must double it 823(for instance, "file=my,,file" to use file "my,file"). 824 825Special files such as iSCSI devices can be specified using protocol 826specific URLs. See the section for "Device URL Syntax" for more information. 827@item if=@var{interface} 828This option defines on which type on interface the drive is connected. 829Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 830@item bus=@var{bus},unit=@var{unit} 831These options define where is connected the drive by defining the bus number and 832the unit id. 833@item index=@var{index} 834This option defines where is connected the drive by using an index in the list 835of available connectors of a given interface type. 836@item media=@var{media} 837This option defines the type of the media: disk or cdrom. 838@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}] 839These options have the same definition as they have in @option{-hdachs}. 840These parameters are deprecated, use the corresponding parameters 841of @code{-device} instead. 842@item snapshot=@var{snapshot} 843@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 844(see @option{-snapshot}). 845@item cache=@var{cache} 846@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 847and controls how the host cache is used to access block data. This is a 848shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 849options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 850which provides a default for the @option{write-cache} option of block guest 851devices (as in @option{-device}). The modes correspond to the following 852settings: 853 854@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 855@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 856@c and the HTML output. 857@example 858@ │ cache.writeback cache.direct cache.no-flush 859─────────────┼───────────────────────────────────────────────── 860writeback │ on off off 861none │ on on off 862writethrough │ off off off 863directsync │ off on off 864unsafe │ on off on 865@end example 866 867The default mode is @option{cache=writeback}. 868 869@item aio=@var{aio} 870@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 871@item format=@var{format} 872Specify which disk @var{format} will be used rather than detecting 873the format. Can be used to specify format=raw to avoid interpreting 874an untrusted format header. 875@item serial=@var{serial} 876This option specifies the serial number to assign to the device. This 877parameter is deprecated, use the corresponding parameter of @code{-device} 878instead. 879@item addr=@var{addr} 880Specify the controller's PCI address (if=virtio only). This parameter is 881deprecated, use the corresponding parameter of @code{-device} instead. 882@item werror=@var{action},rerror=@var{action} 883Specify which @var{action} to take on write and read errors. Valid actions are: 884"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 885"report" (report the error to the guest), "enospc" (pause QEMU only if the 886host disk is full; report the error to the guest otherwise). 887The default setting is @option{werror=enospc} and @option{rerror=report}. 888@item copy-on-read=@var{copy-on-read} 889@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 890file sectors into the image file. 891@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 892Specify bandwidth throttling limits in bytes per second, either for all request 893types or for reads or writes only. Small values can lead to timeouts or hangs 894inside the guest. A safe minimum for disks is 2 MB/s. 895@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 896Specify bursts in bytes per second, either for all request types or for reads 897or writes only. Bursts allow the guest I/O to spike above the limit 898temporarily. 899@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 900Specify request rate limits in requests per second, either for all request 901types or for reads or writes only. 902@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 903Specify bursts in requests per second, either for all request types or for reads 904or writes only. Bursts allow the guest I/O to spike above the limit 905temporarily. 906@item iops_size=@var{is} 907Let every @var{is} bytes of a request count as a new request for iops 908throttling purposes. Use this option to prevent guests from circumventing iops 909limits by sending fewer but larger requests. 910@item group=@var{g} 911Join a throttling quota group with given name @var{g}. All drives that are 912members of the same group are accounted for together. Use this option to 913prevent guests from circumventing throttling limits by using many small disks 914instead of a single larger disk. 915@end table 916 917By default, the @option{cache.writeback=on} mode is used. It will report data 918writes as completed as soon as the data is present in the host page cache. 919This is safe as long as your guest OS makes sure to correctly flush disk caches 920where needed. If your guest OS does not handle volatile disk write caches 921correctly and your host crashes or loses power, then the guest may experience 922data corruption. 923 924For such guests, you should consider using @option{cache.writeback=off}. This 925means that the host page cache will be used to read and write data, but write 926notification will be sent to the guest only after QEMU has made sure to flush 927each write to the disk. Be aware that this has a major impact on performance. 928 929When using the @option{-snapshot} option, unsafe caching is always used. 930 931Copy-on-read avoids accessing the same backing file sectors repeatedly and is 932useful when the backing file is over a slow network. By default copy-on-read 933is off. 934 935Instead of @option{-cdrom} you can use: 936@example 937qemu-system-i386 -drive file=file,index=2,media=cdrom 938@end example 939 940Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 941use: 942@example 943qemu-system-i386 -drive file=file,index=0,media=disk 944qemu-system-i386 -drive file=file,index=1,media=disk 945qemu-system-i386 -drive file=file,index=2,media=disk 946qemu-system-i386 -drive file=file,index=3,media=disk 947@end example 948 949You can open an image using pre-opened file descriptors from an fd set: 950@example 951qemu-system-i386 952-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 953-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 954-drive file=/dev/fdset/2,index=0,media=disk 955@end example 956 957You can connect a CDROM to the slave of ide0: 958@example 959qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom 960@end example 961 962If you don't specify the "file=" argument, you define an empty drive: 963@example 964qemu-system-i386 -drive if=ide,index=1,media=cdrom 965@end example 966 967Instead of @option{-fda}, @option{-fdb}, you can use: 968@example 969qemu-system-i386 -drive file=file,index=0,if=floppy 970qemu-system-i386 -drive file=file,index=1,if=floppy 971@end example 972 973By default, @var{interface} is "ide" and @var{index} is automatically 974incremented: 975@example 976qemu-system-i386 -drive file=a -drive file=b" 977@end example 978is interpreted like: 979@example 980qemu-system-i386 -hda a -hdb b 981@end example 982ETEXI 983 984DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 985 "-mtdblock file use 'file' as on-board Flash memory image\n", 986 QEMU_ARCH_ALL) 987STEXI 988@item -mtdblock @var{file} 989@findex -mtdblock 990Use @var{file} as on-board Flash memory image. 991ETEXI 992 993DEF("sd", HAS_ARG, QEMU_OPTION_sd, 994 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 995STEXI 996@item -sd @var{file} 997@findex -sd 998Use @var{file} as SecureDigital card image. 999ETEXI 1000 1001DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1002 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1003STEXI 1004@item -pflash @var{file} 1005@findex -pflash 1006Use @var{file} as a parallel flash image. 1007ETEXI 1008 1009DEF("snapshot", 0, QEMU_OPTION_snapshot, 1010 "-snapshot write to temporary files instead of disk image files\n", 1011 QEMU_ARCH_ALL) 1012STEXI 1013@item -snapshot 1014@findex -snapshot 1015Write to temporary files instead of disk image files. In this case, 1016the raw disk image you use is not written back. You can however force 1017the write back by pressing @key{C-a s} (@pxref{disk_images}). 1018ETEXI 1019 1020DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \ 1021 "-hdachs c,h,s[,t]\n" \ 1022 " force hard disk 0 physical geometry and the optional BIOS\n" \ 1023 " translation (t=none or lba) (usually QEMU can guess them)\n", 1024 QEMU_ARCH_ALL) 1025STEXI 1026@item -hdachs @var{c},@var{h},@var{s},[,@var{t}] 1027@findex -hdachs 1028Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <= 1029@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS 1030translation mode (@var{t}=none, lba or auto). Usually QEMU can guess 1031all those parameters. This option is deprecated, please use 1032@code{-device ide-hd,cyls=c,heads=h,secs=s,...} instead. 1033ETEXI 1034 1035DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1036 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n" 1037 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n" 1038 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1039 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1040 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1041 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1042 " [[,throttling.iops-size=is]]\n", 1043 QEMU_ARCH_ALL) 1044 1045STEXI 1046 1047@item -fsdev @var{fsdriver},id=@var{id},path=@var{path},[security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}] 1048@findex -fsdev 1049Define a new file system device. Valid options are: 1050@table @option 1051@item @var{fsdriver} 1052This option specifies the fs driver backend to use. 1053Currently "local", "handle" and "proxy" file system drivers are supported. 1054@item id=@var{id} 1055Specifies identifier for this device 1056@item path=@var{path} 1057Specifies the export path for the file system device. Files under 1058this path will be available to the 9p client on the guest. 1059@item security_model=@var{security_model} 1060Specifies the security model to be used for this export path. 1061Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1062In "passthrough" security model, files are stored using the same 1063credentials as they are created on the guest. This requires QEMU 1064to run as root. In "mapped-xattr" security model, some of the file 1065attributes like uid, gid, mode bits and link target are stored as 1066file attributes. For "mapped-file" these attributes are stored in the 1067hidden .virtfs_metadata directory. Directories exported by this security model cannot 1068interact with other unix tools. "none" security model is same as 1069passthrough except the sever won't report failures if it fails to 1070set file attributes like ownership. Security model is mandatory 1071only for local fsdriver. Other fsdrivers (like handle, proxy) don't take 1072security model as a parameter. 1073@item writeout=@var{writeout} 1074This is an optional argument. The only supported value is "immediate". 1075This means that host page cache will be used to read and write data but 1076write notification will be sent to the guest only when the data has been 1077reported as written by the storage subsystem. 1078@item readonly 1079Enables exporting 9p share as a readonly mount for guests. By default 1080read-write access is given. 1081@item socket=@var{socket} 1082Enables proxy filesystem driver to use passed socket file for communicating 1083with virtfs-proxy-helper 1084@item sock_fd=@var{sock_fd} 1085Enables proxy filesystem driver to use passed socket descriptor for 1086communicating with virtfs-proxy-helper. Usually a helper like libvirt 1087will create socketpair and pass one of the fds as sock_fd 1088@item fmode=@var{fmode} 1089Specifies the default mode for newly created files on the host. Works only 1090with security models "mapped-xattr" and "mapped-file". 1091@item dmode=@var{dmode} 1092Specifies the default mode for newly created directories on the host. Works 1093only with security models "mapped-xattr" and "mapped-file". 1094@end table 1095 1096-fsdev option is used along with -device driver "virtio-9p-pci". 1097@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag} 1098Options for virtio-9p-pci driver are: 1099@table @option 1100@item fsdev=@var{id} 1101Specifies the id value specified along with -fsdev option 1102@item mount_tag=@var{mount_tag} 1103Specifies the tag name to be used by the guest to mount this export point 1104@end table 1105 1106ETEXI 1107 1108DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1109 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n" 1110 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n", 1111 QEMU_ARCH_ALL) 1112 1113STEXI 1114 1115@item -virtfs @var{fsdriver}[,path=@var{path}],mount_tag=@var{mount_tag}[,security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}] 1116@findex -virtfs 1117 1118The general form of a Virtual File system pass-through options are: 1119@table @option 1120@item @var{fsdriver} 1121This option specifies the fs driver backend to use. 1122Currently "local", "handle" and "proxy" file system drivers are supported. 1123@item id=@var{id} 1124Specifies identifier for this device 1125@item path=@var{path} 1126Specifies the export path for the file system device. Files under 1127this path will be available to the 9p client on the guest. 1128@item security_model=@var{security_model} 1129Specifies the security model to be used for this export path. 1130Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1131In "passthrough" security model, files are stored using the same 1132credentials as they are created on the guest. This requires QEMU 1133to run as root. In "mapped-xattr" security model, some of the file 1134attributes like uid, gid, mode bits and link target are stored as 1135file attributes. For "mapped-file" these attributes are stored in the 1136hidden .virtfs_metadata directory. Directories exported by this security model cannot 1137interact with other unix tools. "none" security model is same as 1138passthrough except the sever won't report failures if it fails to 1139set file attributes like ownership. Security model is mandatory only 1140for local fsdriver. Other fsdrivers (like handle, proxy) don't take security 1141model as a parameter. 1142@item writeout=@var{writeout} 1143This is an optional argument. The only supported value is "immediate". 1144This means that host page cache will be used to read and write data but 1145write notification will be sent to the guest only when the data has been 1146reported as written by the storage subsystem. 1147@item readonly 1148Enables exporting 9p share as a readonly mount for guests. By default 1149read-write access is given. 1150@item socket=@var{socket} 1151Enables proxy filesystem driver to use passed socket file for 1152communicating with virtfs-proxy-helper. Usually a helper like libvirt 1153will create socketpair and pass one of the fds as sock_fd 1154@item sock_fd 1155Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1156descriptor for interfacing with virtfs-proxy-helper 1157@item fmode=@var{fmode} 1158Specifies the default mode for newly created files on the host. Works only 1159with security models "mapped-xattr" and "mapped-file". 1160@item dmode=@var{dmode} 1161Specifies the default mode for newly created directories on the host. Works 1162only with security models "mapped-xattr" and "mapped-file". 1163@end table 1164ETEXI 1165 1166DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 1167 "-virtfs_synth Create synthetic file system image\n", 1168 QEMU_ARCH_ALL) 1169STEXI 1170@item -virtfs_synth 1171@findex -virtfs_synth 1172Create synthetic file system image 1173ETEXI 1174 1175STEXI 1176@end table 1177ETEXI 1178DEFHEADING() 1179 1180DEFHEADING(USB options) 1181STEXI 1182@table @option 1183ETEXI 1184 1185DEF("usb", 0, QEMU_OPTION_usb, 1186 "-usb enable the USB driver (if it is not used by default yet)\n", 1187 QEMU_ARCH_ALL) 1188STEXI 1189@item -usb 1190@findex -usb 1191Enable the USB driver (if it is not used by default yet). 1192ETEXI 1193 1194DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1195 "-usbdevice name add the host or guest USB device 'name'\n", 1196 QEMU_ARCH_ALL) 1197STEXI 1198 1199@item -usbdevice @var{devname} 1200@findex -usbdevice 1201Add the USB device @var{devname}. Note that this option is deprecated, 1202please use @code{-device usb-...} instead. @xref{usb_devices}. 1203 1204@table @option 1205 1206@item mouse 1207Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1208 1209@item tablet 1210Pointer device that uses absolute coordinates (like a touchscreen). This 1211means QEMU is able to report the mouse position without having to grab the 1212mouse. Also overrides the PS/2 mouse emulation when activated. 1213 1214@item disk:[format=@var{format}]:@var{file} 1215Mass storage device based on file. The optional @var{format} argument 1216will be used rather than detecting the format. Can be used to specify 1217@code{format=raw} to avoid interpreting an untrusted format header. 1218 1219@item host:@var{bus}.@var{addr} 1220Pass through the host device identified by @var{bus}.@var{addr} (Linux only). 1221 1222@item host:@var{vendor_id}:@var{product_id} 1223Pass through the host device identified by @var{vendor_id}:@var{product_id} 1224(Linux only). 1225 1226@item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev} 1227Serial converter to host character device @var{dev}, see @code{-serial} for the 1228available devices. 1229 1230@item braille 1231Braille device. This will use BrlAPI to display the braille output on a real 1232or fake device. 1233 1234@item net:@var{options} 1235Network adapter that supports CDC ethernet and RNDIS protocols. 1236 1237@end table 1238ETEXI 1239 1240STEXI 1241@end table 1242ETEXI 1243DEFHEADING() 1244 1245DEFHEADING(Display options) 1246STEXI 1247@table @option 1248ETEXI 1249 1250DEF("display", HAS_ARG, QEMU_OPTION_display, 1251 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1252 " [,window_close=on|off][,gl=on|off]\n" 1253 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1254 "-display vnc=<display>[,<optargs>]\n" 1255 "-display curses\n" 1256 "-display none" 1257 " select display type\n" 1258 "The default display is equivalent to\n" 1259#if defined(CONFIG_GTK) 1260 "\t\"-display gtk\"\n" 1261#elif defined(CONFIG_SDL) 1262 "\t\"-display sdl\"\n" 1263#elif defined(CONFIG_COCOA) 1264 "\t\"-display cocoa\"\n" 1265#elif defined(CONFIG_VNC) 1266 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1267#else 1268 "\t\"-display none\"\n" 1269#endif 1270 , QEMU_ARCH_ALL) 1271STEXI 1272@item -display @var{type} 1273@findex -display 1274Select type of display to use. This option is a replacement for the 1275old style -sdl/-curses/... options. Valid values for @var{type} are 1276@table @option 1277@item sdl 1278Display video output via SDL (usually in a separate graphics 1279window; see the SDL documentation for other possibilities). 1280@item curses 1281Display video output via curses. For graphics device models which 1282support a text mode, QEMU can display this output using a 1283curses/ncurses interface. Nothing is displayed when the graphics 1284device is in graphical mode or if the graphics device does not support 1285a text mode. Generally only the VGA device models support text mode. 1286@item none 1287Do not display video output. The guest will still see an emulated 1288graphics card, but its output will not be displayed to the QEMU 1289user. This option differs from the -nographic option in that it 1290only affects what is done with video output; -nographic also changes 1291the destination of the serial and parallel port data. 1292@item gtk 1293Display video output in a GTK window. This interface provides drop-down 1294menus and other UI elements to configure and control the VM during 1295runtime. 1296@item vnc 1297Start a VNC server on display <arg> 1298@end table 1299ETEXI 1300 1301DEF("nographic", 0, QEMU_OPTION_nographic, 1302 "-nographic disable graphical output and redirect serial I/Os to console\n", 1303 QEMU_ARCH_ALL) 1304STEXI 1305@item -nographic 1306@findex -nographic 1307Normally, if QEMU is compiled with graphical window support, it displays 1308output such as guest graphics, guest console, and the QEMU monitor in a 1309window. With this option, you can totally disable graphical output so 1310that QEMU is a simple command line application. The emulated serial port 1311is redirected on the console and muxed with the monitor (unless 1312redirected elsewhere explicitly). Therefore, you can still use QEMU to 1313debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1314switching between the console and monitor. 1315ETEXI 1316 1317DEF("curses", 0, QEMU_OPTION_curses, 1318 "-curses shorthand for -display curses\n", 1319 QEMU_ARCH_ALL) 1320STEXI 1321@item -curses 1322@findex -curses 1323Normally, if QEMU is compiled with graphical window support, it displays 1324output such as guest graphics, guest console, and the QEMU monitor in a 1325window. With this option, QEMU can display the VGA output when in text 1326mode using a curses/ncurses interface. Nothing is displayed in graphical 1327mode. 1328ETEXI 1329 1330DEF("no-frame", 0, QEMU_OPTION_no_frame, 1331 "-no-frame open SDL window without a frame and window decorations\n", 1332 QEMU_ARCH_ALL) 1333STEXI 1334@item -no-frame 1335@findex -no-frame 1336Do not use decorations for SDL windows and start them using the whole 1337available screen space. This makes the using QEMU in a dedicated desktop 1338workspace more convenient. 1339ETEXI 1340 1341DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1342 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1343 QEMU_ARCH_ALL) 1344STEXI 1345@item -alt-grab 1346@findex -alt-grab 1347Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1348affects the special keys (for fullscreen, monitor-mode switching, etc). 1349ETEXI 1350 1351DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1352 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1353 QEMU_ARCH_ALL) 1354STEXI 1355@item -ctrl-grab 1356@findex -ctrl-grab 1357Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1358affects the special keys (for fullscreen, monitor-mode switching, etc). 1359ETEXI 1360 1361DEF("no-quit", 0, QEMU_OPTION_no_quit, 1362 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1363STEXI 1364@item -no-quit 1365@findex -no-quit 1366Disable SDL window close capability. 1367ETEXI 1368 1369DEF("sdl", 0, QEMU_OPTION_sdl, 1370 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1371STEXI 1372@item -sdl 1373@findex -sdl 1374Enable SDL. 1375ETEXI 1376 1377DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1378 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1379 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1380 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1381 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1382 " [,tls-ciphers=<list>]\n" 1383 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1384 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1385 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1386 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1387 " [,jpeg-wan-compression=[auto|never|always]]\n" 1388 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1389 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1390 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1391 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1392 " [,gl=[on|off]][,rendernode=<file>]\n" 1393 " enable spice\n" 1394 " at least one of {port, tls-port} is mandatory\n", 1395 QEMU_ARCH_ALL) 1396STEXI 1397@item -spice @var{option}[,@var{option}[,...]] 1398@findex -spice 1399Enable the spice remote desktop protocol. Valid options are 1400 1401@table @option 1402 1403@item port=<nr> 1404Set the TCP port spice is listening on for plaintext channels. 1405 1406@item addr=<addr> 1407Set the IP address spice is listening on. Default is any address. 1408 1409@item ipv4 1410@itemx ipv6 1411@itemx unix 1412Force using the specified IP version. 1413 1414@item password=<secret> 1415Set the password you need to authenticate. 1416 1417@item sasl 1418Require that the client use SASL to authenticate with the spice. 1419The exact choice of authentication method used is controlled from the 1420system / user's SASL configuration file for the 'qemu' service. This 1421is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1422unprivileged user, an environment variable SASL_CONF_PATH can be used 1423to make it search alternate locations for the service config. 1424While some SASL auth methods can also provide data encryption (eg GSSAPI), 1425it is recommended that SASL always be combined with the 'tls' and 1426'x509' settings to enable use of SSL and server certificates. This 1427ensures a data encryption preventing compromise of authentication 1428credentials. 1429 1430@item disable-ticketing 1431Allow client connects without authentication. 1432 1433@item disable-copy-paste 1434Disable copy paste between the client and the guest. 1435 1436@item disable-agent-file-xfer 1437Disable spice-vdagent based file-xfer between the client and the guest. 1438 1439@item tls-port=<nr> 1440Set the TCP port spice is listening on for encrypted channels. 1441 1442@item x509-dir=<dir> 1443Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1444 1445@item x509-key-file=<file> 1446@itemx x509-key-password=<file> 1447@itemx x509-cert-file=<file> 1448@itemx x509-cacert-file=<file> 1449@itemx x509-dh-key-file=<file> 1450The x509 file names can also be configured individually. 1451 1452@item tls-ciphers=<list> 1453Specify which ciphers to use. 1454 1455@item tls-channel=[main|display|cursor|inputs|record|playback] 1456@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1457Force specific channel to be used with or without TLS encryption. The 1458options can be specified multiple times to configure multiple 1459channels. The special name "default" can be used to set the default 1460mode. For channels which are not explicitly forced into one mode the 1461spice client is allowed to pick tls/plaintext as he pleases. 1462 1463@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1464Configure image compression (lossless). 1465Default is auto_glz. 1466 1467@item jpeg-wan-compression=[auto|never|always] 1468@itemx zlib-glz-wan-compression=[auto|never|always] 1469Configure wan image compression (lossy for slow links). 1470Default is auto. 1471 1472@item streaming-video=[off|all|filter] 1473Configure video stream detection. Default is off. 1474 1475@item agent-mouse=[on|off] 1476Enable/disable passing mouse events via vdagent. Default is on. 1477 1478@item playback-compression=[on|off] 1479Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1480 1481@item seamless-migration=[on|off] 1482Enable/disable spice seamless migration. Default is off. 1483 1484@item gl=[on|off] 1485Enable/disable OpenGL context. Default is off. 1486 1487@item rendernode=<file> 1488DRM render node for OpenGL rendering. If not specified, it will pick 1489the first available. (Since 2.9) 1490 1491@end table 1492ETEXI 1493 1494DEF("portrait", 0, QEMU_OPTION_portrait, 1495 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1496 QEMU_ARCH_ALL) 1497STEXI 1498@item -portrait 1499@findex -portrait 1500Rotate graphical output 90 deg left (only PXA LCD). 1501ETEXI 1502 1503DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1504 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1505 QEMU_ARCH_ALL) 1506STEXI 1507@item -rotate @var{deg} 1508@findex -rotate 1509Rotate graphical output some deg left (only PXA LCD). 1510ETEXI 1511 1512DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1513 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1514 " select video card type\n", QEMU_ARCH_ALL) 1515STEXI 1516@item -vga @var{type} 1517@findex -vga 1518Select type of VGA card to emulate. Valid values for @var{type} are 1519@table @option 1520@item cirrus 1521Cirrus Logic GD5446 Video card. All Windows versions starting from 1522Windows 95 should recognize and use this graphic card. For optimal 1523performances, use 16 bit color depth in the guest and the host OS. 1524(This card was the default before QEMU 2.2) 1525@item std 1526Standard VGA card with Bochs VBE extensions. If your guest OS 1527supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1528to use high resolution modes (>= 1280x1024x16) then you should use 1529this option. (This card is the default since QEMU 2.2) 1530@item vmware 1531VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1532recent XFree86/XOrg server or Windows guest with a driver for this 1533card. 1534@item qxl 1535QXL paravirtual graphic card. It is VGA compatible (including VESA 15362.0 VBE support). Works best with qxl guest drivers installed though. 1537Recommended choice when using the spice protocol. 1538@item tcx 1539(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1540sun4m machines and offers both 8-bit and 24-bit colour depths at a 1541fixed resolution of 1024x768. 1542@item cg3 1543(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1544for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1545resolutions aimed at people wishing to run older Solaris versions. 1546@item virtio 1547Virtio VGA card. 1548@item none 1549Disable VGA card. 1550@end table 1551ETEXI 1552 1553DEF("full-screen", 0, QEMU_OPTION_full_screen, 1554 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1555STEXI 1556@item -full-screen 1557@findex -full-screen 1558Start in full screen. 1559ETEXI 1560 1561DEF("g", 1, QEMU_OPTION_g , 1562 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1563 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1564STEXI 1565@item -g @var{width}x@var{height}[x@var{depth}] 1566@findex -g 1567Set the initial graphical resolution and depth (PPC, SPARC only). 1568ETEXI 1569 1570DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1571 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1572STEXI 1573@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1574@findex -vnc 1575Normally, if QEMU is compiled with graphical window support, it displays 1576output such as guest graphics, guest console, and the QEMU monitor in a 1577window. With this option, you can have QEMU listen on VNC display 1578@var{display} and redirect the VGA display over the VNC session. It is 1579very useful to enable the usb tablet device when using this option 1580(option @option{-device usb-tablet}). When using the VNC display, you 1581must use the @option{-k} parameter to set the keyboard layout if you are 1582not using en-us. Valid syntax for the @var{display} is 1583 1584@table @option 1585 1586@item to=@var{L} 1587 1588With this option, QEMU will try next available VNC @var{display}s, until the 1589number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1590available, e.g. port 5900+@var{display} is already used by another 1591application. By default, to=0. 1592 1593@item @var{host}:@var{d} 1594 1595TCP connections will only be allowed from @var{host} on display @var{d}. 1596By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1597be omitted in which case the server will accept connections from any host. 1598 1599@item unix:@var{path} 1600 1601Connections will be allowed over UNIX domain sockets where @var{path} is the 1602location of a unix socket to listen for connections on. 1603 1604@item none 1605 1606VNC is initialized but not started. The monitor @code{change} command 1607can be used to later start the VNC server. 1608 1609@end table 1610 1611Following the @var{display} value there may be one or more @var{option} flags 1612separated by commas. Valid options are 1613 1614@table @option 1615 1616@item reverse 1617 1618Connect to a listening VNC client via a ``reverse'' connection. The 1619client is specified by the @var{display}. For reverse network 1620connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1621is a TCP port number, not a display number. 1622 1623@item websocket 1624 1625Opens an additional TCP listening port dedicated to VNC Websocket connections. 1626If a bare @var{websocket} option is given, the Websocket port is 16275700+@var{display}. An alternative port can be specified with the 1628syntax @code{websocket}=@var{port}. 1629 1630If @var{host} is specified connections will only be allowed from this host. 1631It is possible to control the websocket listen address independently, using 1632the syntax @code{websocket}=@var{host}:@var{port}. 1633 1634If no TLS credentials are provided, the websocket connection runs in 1635unencrypted mode. If TLS credentials are provided, the websocket connection 1636requires encrypted client connections. 1637 1638@item password 1639 1640Require that password based authentication is used for client connections. 1641 1642The password must be set separately using the @code{set_password} command in 1643the @ref{pcsys_monitor}. The syntax to change your password is: 1644@code{set_password <protocol> <password>} where <protocol> could be either 1645"vnc" or "spice". 1646 1647If you would like to change <protocol> password expiration, you should use 1648@code{expire_password <protocol> <expiration-time>} where expiration time could 1649be one of the following options: now, never, +seconds or UNIX time of 1650expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1651to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1652date and time). 1653 1654You can also use keywords "now" or "never" for the expiration time to 1655allow <protocol> password to expire immediately or never expire. 1656 1657@item tls-creds=@var{ID} 1658 1659Provides the ID of a set of TLS credentials to use to secure the 1660VNC server. They will apply to both the normal VNC server socket 1661and the websocket socket (if enabled). Setting TLS credentials 1662will cause the VNC server socket to enable the VeNCrypt auth 1663mechanism. The credentials should have been previously created 1664using the @option{-object tls-creds} argument. 1665 1666The @option{tls-creds} parameter obsoletes the @option{tls}, 1667@option{x509}, and @option{x509verify} options, and as such 1668it is not permitted to set both new and old type options at 1669the same time. 1670 1671@item tls 1672 1673Require that client use TLS when communicating with the VNC server. This 1674uses anonymous TLS credentials so is susceptible to a man-in-the-middle 1675attack. It is recommended that this option be combined with either the 1676@option{x509} or @option{x509verify} options. 1677 1678This option is now deprecated in favor of using the @option{tls-creds} 1679argument. 1680 1681@item x509=@var{/path/to/certificate/dir} 1682 1683Valid if @option{tls} is specified. Require that x509 credentials are used 1684for negotiating the TLS session. The server will send its x509 certificate 1685to the client. It is recommended that a password be set on the VNC server 1686to provide authentication of the client when this is used. The path following 1687this option specifies where the x509 certificates are to be loaded from. 1688See the @ref{vnc_security} section for details on generating certificates. 1689 1690This option is now deprecated in favour of using the @option{tls-creds} 1691argument. 1692 1693@item x509verify=@var{/path/to/certificate/dir} 1694 1695Valid if @option{tls} is specified. Require that x509 credentials are used 1696for negotiating the TLS session. The server will send its x509 certificate 1697to the client, and request that the client send its own x509 certificate. 1698The server will validate the client's certificate against the CA certificate, 1699and reject clients when validation fails. If the certificate authority is 1700trusted, this is a sufficient authentication mechanism. You may still wish 1701to set a password on the VNC server as a second authentication layer. The 1702path following this option specifies where the x509 certificates are to 1703be loaded from. See the @ref{vnc_security} section for details on generating 1704certificates. 1705 1706This option is now deprecated in favour of using the @option{tls-creds} 1707argument. 1708 1709@item sasl 1710 1711Require that the client use SASL to authenticate with the VNC server. 1712The exact choice of authentication method used is controlled from the 1713system / user's SASL configuration file for the 'qemu' service. This 1714is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1715unprivileged user, an environment variable SASL_CONF_PATH can be used 1716to make it search alternate locations for the service config. 1717While some SASL auth methods can also provide data encryption (eg GSSAPI), 1718it is recommended that SASL always be combined with the 'tls' and 1719'x509' settings to enable use of SSL and server certificates. This 1720ensures a data encryption preventing compromise of authentication 1721credentials. See the @ref{vnc_security} section for details on using 1722SASL authentication. 1723 1724@item acl 1725 1726Turn on access control lists for checking of the x509 client certificate 1727and SASL party. For x509 certs, the ACL check is made against the 1728certificate's distinguished name. This is something that looks like 1729@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is 1730made against the username, which depending on the SASL plugin, may 1731include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}. 1732When the @option{acl} flag is set, the initial access list will be 1733empty, with a @code{deny} policy. Thus no one will be allowed to 1734use the VNC server until the ACLs have been loaded. This can be 1735achieved using the @code{acl} monitor command. 1736 1737@item lossy 1738 1739Enable lossy compression methods (gradient, JPEG, ...). If this 1740option is set, VNC client may receive lossy framebuffer updates 1741depending on its encoding settings. Enabling this option can save 1742a lot of bandwidth at the expense of quality. 1743 1744@item non-adaptive 1745 1746Disable adaptive encodings. Adaptive encodings are enabled by default. 1747An adaptive encoding will try to detect frequently updated screen regions, 1748and send updates in these regions using a lossy encoding (like JPEG). 1749This can be really helpful to save bandwidth when playing videos. Disabling 1750adaptive encodings restores the original static behavior of encodings 1751like Tight. 1752 1753@item share=[allow-exclusive|force-shared|ignore] 1754 1755Set display sharing policy. 'allow-exclusive' allows clients to ask 1756for exclusive access. As suggested by the rfb spec this is 1757implemented by dropping other connections. Connecting multiple 1758clients in parallel requires all clients asking for a shared session 1759(vncviewer: -shared switch). This is the default. 'force-shared' 1760disables exclusive client access. Useful for shared desktop sessions, 1761where you don't want someone forgetting specify -shared disconnect 1762everybody else. 'ignore' completely ignores the shared flag and 1763allows everybody connect unconditionally. Doesn't conform to the rfb 1764spec but is traditional QEMU behavior. 1765 1766@item key-delay-ms 1767 1768Set keyboard delay, for key down and key up events, in milliseconds. 1769Default is 10. Keyboards are low-bandwidth devices, so this slowdown 1770can help the device and guest to keep up and not lose events in case 1771events are arriving in bulk. Possible causes for the latter are flaky 1772network connections, or scripts for automated testing. 1773 1774@end table 1775ETEXI 1776 1777STEXI 1778@end table 1779ETEXI 1780ARCHHEADING(, QEMU_ARCH_I386) 1781 1782ARCHHEADING(i386 target only, QEMU_ARCH_I386) 1783STEXI 1784@table @option 1785ETEXI 1786 1787DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1788 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1789 QEMU_ARCH_I386) 1790STEXI 1791@item -win2k-hack 1792@findex -win2k-hack 1793Use it when installing Windows 2000 to avoid a disk full bug. After 1794Windows 2000 is installed, you no longer need this option (this option 1795slows down the IDE transfers). 1796ETEXI 1797 1798HXCOMM Deprecated by -rtc 1799DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386) 1800 1801DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 1802 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 1803 QEMU_ARCH_I386) 1804STEXI 1805@item -no-fd-bootchk 1806@findex -no-fd-bootchk 1807Disable boot signature checking for floppy disks in BIOS. May 1808be needed to boot from old floppy disks. 1809ETEXI 1810 1811DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 1812 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1813STEXI 1814@item -no-acpi 1815@findex -no-acpi 1816Disable ACPI (Advanced Configuration and Power Interface) support. Use 1817it if your guest OS complains about ACPI problems (PC target machine 1818only). 1819ETEXI 1820 1821DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 1822 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 1823STEXI 1824@item -no-hpet 1825@findex -no-hpet 1826Disable HPET support. 1827ETEXI 1828 1829DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 1830 "-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" 1831 " ACPI table description\n", QEMU_ARCH_I386) 1832STEXI 1833@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}]...] 1834@findex -acpitable 1835Add ACPI table with specified header fields and context from specified files. 1836For file=, take whole ACPI table from the specified files, including all 1837ACPI headers (possible overridden by other options). 1838For data=, only data 1839portion of the table is used, all header information is specified in the 1840command line. 1841If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 1842fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 1843to ensure the field matches required by the Microsoft SLIC spec and the ACPI 1844spec. 1845ETEXI 1846 1847DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 1848 "-smbios file=binary\n" 1849 " load SMBIOS entry from binary file\n" 1850 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 1851 " [,uefi=on|off]\n" 1852 " specify SMBIOS type 0 fields\n" 1853 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1854 " [,uuid=uuid][,sku=str][,family=str]\n" 1855 " specify SMBIOS type 1 fields\n" 1856 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1857 " [,asset=str][,location=str]\n" 1858 " specify SMBIOS type 2 fields\n" 1859 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 1860 " [,sku=str]\n" 1861 " specify SMBIOS type 3 fields\n" 1862 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 1863 " [,asset=str][,part=str]\n" 1864 " specify SMBIOS type 4 fields\n" 1865 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 1866 " [,asset=str][,part=str][,speed=%d]\n" 1867 " specify SMBIOS type 17 fields\n", 1868 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1869STEXI 1870@item -smbios file=@var{binary} 1871@findex -smbios 1872Load SMBIOS entry from binary file. 1873 1874@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 1875Specify SMBIOS type 0 fields 1876 1877@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}] 1878Specify SMBIOS type 1 fields 1879 1880@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}] 1881Specify SMBIOS type 2 fields 1882 1883@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 1884Specify SMBIOS type 3 fields 1885 1886@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 1887Specify SMBIOS type 4 fields 1888 1889@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}] 1890Specify SMBIOS type 17 fields 1891ETEXI 1892 1893STEXI 1894@end table 1895ETEXI 1896DEFHEADING() 1897 1898DEFHEADING(Network options) 1899STEXI 1900@table @option 1901ETEXI 1902 1903HXCOMM Legacy slirp options (now moved to -net user): 1904#ifdef CONFIG_SLIRP 1905DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL) 1906DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL) 1907DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL) 1908#ifndef _WIN32 1909DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL) 1910#endif 1911#endif 1912 1913DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 1914#ifdef CONFIG_SLIRP 1915 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 1916 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 1917 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 1918 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n" 1919 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 1920#ifndef _WIN32 1921 "[,smb=dir[,smbserver=addr]]\n" 1922#endif 1923 " configure a user mode network backend with ID 'str',\n" 1924 " its DHCP server and optional services\n" 1925#endif 1926#ifdef _WIN32 1927 "-netdev tap,id=str,ifname=name\n" 1928 " configure a host TAP network backend with ID 'str'\n" 1929#else 1930 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 1931 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 1932 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 1933 " [,poll-us=n]\n" 1934 " configure a host TAP network backend with ID 'str'\n" 1935 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1936 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 1937 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 1938 " to deconfigure it\n" 1939 " use '[down]script=no' to disable script execution\n" 1940 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 1941 " configure it\n" 1942 " use 'fd=h' to connect to an already opened TAP interface\n" 1943 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 1944 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 1945 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 1946 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 1947 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 1948 " use vhost=on to enable experimental in kernel accelerator\n" 1949 " (only has effect for virtio guests which use MSIX)\n" 1950 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 1951 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 1952 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 1953 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 1954 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 1955 " spent on busy polling for vhost net\n" 1956 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 1957 " configure a host TAP network backend with ID 'str' that is\n" 1958 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1959 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 1960#endif 1961#ifdef __linux__ 1962 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 1963 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 1964 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 1965 " [,rxcookie=rxcookie][,offset=offset]\n" 1966 " configure a network backend with ID 'str' connected to\n" 1967 " an Ethernet over L2TPv3 pseudowire.\n" 1968 " Linux kernel 3.3+ as well as most routers can talk\n" 1969 " L2TPv3. This transport allows connecting a VM to a VM,\n" 1970 " VM to a router and even VM to Host. It is a nearly-universal\n" 1971 " standard (RFC3391). Note - this implementation uses static\n" 1972 " pre-configured tunnels (same as the Linux kernel).\n" 1973 " use 'src=' to specify source address\n" 1974 " use 'dst=' to specify destination address\n" 1975 " use 'udp=on' to specify udp encapsulation\n" 1976 " use 'srcport=' to specify source udp port\n" 1977 " use 'dstport=' to specify destination udp port\n" 1978 " use 'ipv6=on' to force v6\n" 1979 " L2TPv3 uses cookies to prevent misconfiguration as\n" 1980 " well as a weak security measure\n" 1981 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 1982 " use 'txcookie=0x012345678' to specify a txcookie\n" 1983 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 1984 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 1985 " use 'pincounter=on' to work around broken counter handling in peer\n" 1986 " use 'offset=X' to add an extra offset between header and data\n" 1987#endif 1988 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 1989 " configure a network backend to connect to another network\n" 1990 " using a socket connection\n" 1991 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 1992 " configure a network backend to connect to a multicast maddr and port\n" 1993 " use 'localaddr=addr' to specify the host address to send packets from\n" 1994 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 1995 " configure a network backend to connect to another network\n" 1996 " using an UDP tunnel\n" 1997#ifdef CONFIG_VDE 1998 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 1999 " configure a network backend to connect to port 'n' of a vde switch\n" 2000 " running on host and listening for incoming connections on 'socketpath'.\n" 2001 " Use group 'groupname' and mode 'octalmode' to change default\n" 2002 " ownership and permissions for communication port.\n" 2003#endif 2004#ifdef CONFIG_NETMAP 2005 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2006 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2007 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2008 " netmap device, defaults to '/dev/netmap')\n" 2009#endif 2010 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2011 " configure a vhost-user network, backed by a chardev 'dev'\n" 2012 "-netdev hubport,id=str,hubid=n\n" 2013 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL) 2014DEF("net", HAS_ARG, QEMU_OPTION_net, 2015 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2016 " old way to create a new NIC and connect it to VLAN 'n'\n" 2017 " (use the '-device devtype,netdev=str' option if possible instead)\n" 2018 "-net dump[,vlan=n][,file=f][,len=n]\n" 2019 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n" 2020 "-net none use it alone to have zero network devices. If no -net option\n" 2021 " is provided, the default is '-net nic -net user'\n" 2022 "-net [" 2023#ifdef CONFIG_SLIRP 2024 "user|" 2025#endif 2026 "tap|" 2027 "bridge|" 2028#ifdef CONFIG_VDE 2029 "vde|" 2030#endif 2031#ifdef CONFIG_NETMAP 2032 "netmap|" 2033#endif 2034 "socket][,vlan=n][,option][,option][,...]\n" 2035 " old way to initialize a host network interface\n" 2036 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2037STEXI 2038@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2039@findex -net 2040Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n} 2041= 0 is the default). The NIC is an e1000 by default on the PC 2042target. Optionally, the MAC address can be changed to @var{mac}, the 2043device address set to @var{addr} (PCI cards only), 2044and a @var{name} can be assigned for use in monitor commands. 2045Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2046that the card should have; this option currently only affects virtio cards; set 2047@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2048NIC is created. QEMU can emulate several different models of network card. 2049Valid values for @var{type} are 2050@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er}, 2051@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139}, 2052@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}. 2053Not all devices are supported on all targets. Use @code{-net nic,model=help} 2054for a list of available devices for your target. 2055 2056@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2057@findex -netdev 2058@item -net user[,@var{option}][,@var{option}][,...] 2059Use the user mode network stack which requires no administrator 2060privilege to run. Valid options are: 2061 2062@table @option 2063@item vlan=@var{n} 2064Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default). 2065 2066@item id=@var{id} 2067@itemx name=@var{name} 2068Assign symbolic name for use in monitor commands. 2069 2070@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must 2071be enabled. If neither is specified both protocols are enabled. 2072 2073@item net=@var{addr}[/@var{mask}] 2074Set IP network address the guest will see. Optionally specify the netmask, 2075either in the form a.b.c.d or as number of valid top-most bits. Default is 207610.0.2.0/24. 2077 2078@item host=@var{addr} 2079Specify the guest-visible address of the host. Default is the 2nd IP in the 2080guest network, i.e. x.x.x.2. 2081 2082@item ipv6-net=@var{addr}[/@var{int}] 2083Set IPv6 network address the guest will see (default is fec0::/64). The 2084network prefix is given in the usual hexadecimal IPv6 address 2085notation. The prefix size is optional, and is given as the number of 2086valid top-most bits (default is 64). 2087 2088@item ipv6-host=@var{addr} 2089Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2090the guest network, i.e. xxxx::2. 2091 2092@item restrict=on|off 2093If this option is enabled, the guest will be isolated, i.e. it will not be 2094able to contact the host and no guest IP packets will be routed over the host 2095to the outside. This option does not affect any explicitly set forwarding rules. 2096 2097@item hostname=@var{name} 2098Specifies the client hostname reported by the built-in DHCP server. 2099 2100@item dhcpstart=@var{addr} 2101Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2102is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2103 2104@item dns=@var{addr} 2105Specify the guest-visible address of the virtual nameserver. The address must 2106be different from the host address. Default is the 3rd IP in the guest network, 2107i.e. x.x.x.3. 2108 2109@item ipv6-dns=@var{addr} 2110Specify the guest-visible address of the IPv6 virtual nameserver. The address 2111must be different from the host address. Default is the 3rd IP in the guest 2112network, i.e. xxxx::3. 2113 2114@item dnssearch=@var{domain} 2115Provides an entry for the domain-search list sent by the built-in 2116DHCP server. More than one domain suffix can be transmitted by specifying 2117this option multiple times. If supported, this will cause the guest to 2118automatically try to append the given domain suffix(es) in case a domain name 2119can not be resolved. 2120 2121Example: 2122@example 2123qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...] 2124@end example 2125 2126@item tftp=@var{dir} 2127When using the user mode network stack, activate a built-in TFTP 2128server. The files in @var{dir} will be exposed as the root of a TFTP server. 2129The TFTP client on the guest must be configured in binary mode (use the command 2130@code{bin} of the Unix TFTP client). 2131 2132@item bootfile=@var{file} 2133When using the user mode network stack, broadcast @var{file} as the BOOTP 2134filename. In conjunction with @option{tftp}, this can be used to network boot 2135a guest from a local directory. 2136 2137Example (using pxelinux): 2138@example 2139qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2140@end example 2141 2142@item smb=@var{dir}[,smbserver=@var{addr}] 2143When using the user mode network stack, activate a built-in SMB 2144server so that Windows OSes can access to the host files in @file{@var{dir}} 2145transparently. The IP address of the SMB server can be set to @var{addr}. By 2146default the 4th IP in the guest network is used, i.e. x.x.x.4. 2147 2148In the guest Windows OS, the line: 2149@example 215010.0.2.4 smbserver 2151@end example 2152must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2153or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2154 2155Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2156 2157Note that a SAMBA server must be installed on the host OS. 2158QEMU was tested successfully with smbd versions from Red Hat 9, 2159Fedora Core 3 and OpenSUSE 11.x. 2160 2161@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2162Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2163the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2164@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2165given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2166be bound to a specific host interface. If no connection type is set, TCP is 2167used. This option can be given multiple times. 2168 2169For example, to redirect host X11 connection from screen 1 to guest 2170screen 0, use the following: 2171 2172@example 2173# on the host 2174qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...] 2175# this host xterm should open in the guest X11 server 2176xterm -display :1 2177@end example 2178 2179To redirect telnet connections from host port 5555 to telnet port on 2180the guest, use the following: 2181 2182@example 2183# on the host 2184qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...] 2185telnet localhost 5555 2186@end example 2187 2188Then when you use on the host @code{telnet localhost 5555}, you 2189connect to the guest telnet server. 2190 2191@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2192@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2193Forward guest TCP connections to the IP address @var{server} on port @var{port} 2194to the character device @var{dev} or to a program executed by @var{cmd:command} 2195which gets spawned for each connection. This option can be given multiple times. 2196 2197You can either use a chardev directly and have that one used throughout QEMU's 2198lifetime, like in the following example: 2199 2200@example 2201# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2202# the guest accesses it 2203qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...] 2204@end example 2205 2206Or you can execute a command on every TCP connection established by the guest, 2207so that QEMU behaves similar to an inetd process for that virtual server: 2208 2209@example 2210# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2211# and connect the TCP stream to its stdin/stdout 2212qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2213@end example 2214 2215@end table 2216 2217Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still 2218processed and applied to -net user. Mixing them with the new configuration 2219syntax gives undefined results. Their use for new applications is discouraged 2220as they will be removed from future versions. 2221 2222@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2223@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2224Connect the host TAP network interface @var{name} to VLAN @var{n}. 2225 2226Use the network script @var{file} to configure it and the network script 2227@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2228automatically provides one. The default network configure script is 2229@file{/etc/qemu-ifup} and the default network deconfigure script is 2230@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2231to disable script execution. 2232 2233If running QEMU as an unprivileged user, use the network helper 2234@var{helper} to configure the TAP interface and attach it to the bridge. 2235The default network helper executable is @file{/path/to/qemu-bridge-helper} 2236and the default bridge device is @file{br0}. 2237 2238@option{fd}=@var{h} can be used to specify the handle of an already 2239opened host TAP interface. 2240 2241Examples: 2242 2243@example 2244#launch a QEMU instance with the default network script 2245qemu-system-i386 linux.img -net nic -net tap 2246@end example 2247 2248@example 2249#launch a QEMU instance with two NICs, each one connected 2250#to a TAP device 2251qemu-system-i386 linux.img \ 2252 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \ 2253 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1 2254@end example 2255 2256@example 2257#launch a QEMU instance with the default network helper to 2258#connect a TAP device to bridge br0 2259qemu-system-i386 linux.img \ 2260 -net nic -net tap,"helper=/path/to/qemu-bridge-helper" 2261@end example 2262 2263@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2264@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}] 2265Connect a host TAP network interface to a host bridge device. 2266 2267Use the network helper @var{helper} to configure the TAP interface and 2268attach it to the bridge. The default network helper executable is 2269@file{/path/to/qemu-bridge-helper} and the default bridge 2270device is @file{br0}. 2271 2272Examples: 2273 2274@example 2275#launch a QEMU instance with the default network helper to 2276#connect a TAP device to bridge br0 2277qemu-system-i386 linux.img -net bridge -net nic,model=virtio 2278@end example 2279 2280@example 2281#launch a QEMU instance with the default network helper to 2282#connect a TAP device to bridge qemubr0 2283qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio 2284@end example 2285 2286@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2287@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2288 2289Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual 2290machine using a TCP socket connection. If @option{listen} is 2291specified, QEMU waits for incoming connections on @var{port} 2292(@var{host} is optional). @option{connect} is used to connect to 2293another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2294specifies an already opened TCP socket. 2295 2296Example: 2297@example 2298# launch a first QEMU instance 2299qemu-system-i386 linux.img \ 2300 -net nic,macaddr=52:54:00:12:34:56 \ 2301 -net socket,listen=:1234 2302# connect the VLAN 0 of this instance to the VLAN 0 2303# of the first instance 2304qemu-system-i386 linux.img \ 2305 -net nic,macaddr=52:54:00:12:34:57 \ 2306 -net socket,connect=127.0.0.1:1234 2307@end example 2308 2309@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2310@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2311 2312Create a VLAN @var{n} shared with another QEMU virtual 2313machines using a UDP multicast socket, effectively making a bus for 2314every QEMU with same multicast address @var{maddr} and @var{port}. 2315NOTES: 2316@enumerate 2317@item 2318Several QEMU can be running on different hosts and share same bus (assuming 2319correct multicast setup for these hosts). 2320@item 2321mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2322@url{http://user-mode-linux.sf.net}. 2323@item 2324Use @option{fd=h} to specify an already opened UDP multicast socket. 2325@end enumerate 2326 2327Example: 2328@example 2329# launch one QEMU instance 2330qemu-system-i386 linux.img \ 2331 -net nic,macaddr=52:54:00:12:34:56 \ 2332 -net socket,mcast=230.0.0.1:1234 2333# launch another QEMU instance on same "bus" 2334qemu-system-i386 linux.img \ 2335 -net nic,macaddr=52:54:00:12:34:57 \ 2336 -net socket,mcast=230.0.0.1:1234 2337# launch yet another QEMU instance on same "bus" 2338qemu-system-i386 linux.img \ 2339 -net nic,macaddr=52:54:00:12:34:58 \ 2340 -net socket,mcast=230.0.0.1:1234 2341@end example 2342 2343Example (User Mode Linux compat.): 2344@example 2345# launch QEMU instance (note mcast address selected 2346# is UML's default) 2347qemu-system-i386 linux.img \ 2348 -net nic,macaddr=52:54:00:12:34:56 \ 2349 -net socket,mcast=239.192.168.1:1102 2350# launch UML 2351/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2352@end example 2353 2354Example (send packets from host's 1.2.3.4): 2355@example 2356qemu-system-i386 linux.img \ 2357 -net nic,macaddr=52:54:00:12:34:56 \ 2358 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2359@end example 2360 2361@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}] 2362@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}] 2363Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular 2364protocol to transport Ethernet (and other Layer 2) data frames between 2365two systems. It is present in routers, firewalls and the Linux kernel 2366(from version 3.3 onwards). 2367 2368This transport allows a VM to communicate to another VM, router or firewall directly. 2369 2370@item src=@var{srcaddr} 2371 source address (mandatory) 2372@item dst=@var{dstaddr} 2373 destination address (mandatory) 2374@item udp 2375 select udp encapsulation (default is ip). 2376@item srcport=@var{srcport} 2377 source udp port. 2378@item dstport=@var{dstport} 2379 destination udp port. 2380@item ipv6 2381 force v6, otherwise defaults to v4. 2382@item rxcookie=@var{rxcookie} 2383@itemx txcookie=@var{txcookie} 2384 Cookies are a weak form of security in the l2tpv3 specification. 2385Their function is mostly to prevent misconfiguration. By default they are 32 2386bit. 2387@item cookie64 2388 Set cookie size to 64 bit instead of the default 32 2389@item counter=off 2390 Force a 'cut-down' L2TPv3 with no counter as in 2391draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2392@item pincounter=on 2393 Work around broken counter handling in peer. This may also help on 2394networks which have packet reorder. 2395@item offset=@var{offset} 2396 Add an extra offset between header and data 2397 2398For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2399on the remote Linux host 1.2.3.4: 2400@example 2401# Setup tunnel on linux host using raw ip as encapsulation 2402# on 1.2.3.4 2403ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2404 encap udp udp_sport 16384 udp_dport 16384 2405ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2406 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2407ifconfig vmtunnel0 mtu 1500 2408ifconfig vmtunnel0 up 2409brctl addif br-lan vmtunnel0 2410 2411 2412# on 4.3.2.1 2413# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2414 2415qemu-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 2416 2417 2418@end example 2419 2420@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2421@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2422Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and 2423listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2424and MODE @var{octalmode} to change default ownership and permissions for 2425communication port. This option is only available if QEMU has been compiled 2426with vde support enabled. 2427 2428Example: 2429@example 2430# launch vde switch 2431vde_switch -F -sock /tmp/myswitch 2432# launch QEMU instance 2433qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch 2434@end example 2435 2436@item -netdev hubport,id=@var{id},hubid=@var{hubid} 2437 2438Create a hub port on QEMU "vlan" @var{hubid}. 2439 2440The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single 2441netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the 2442required hub automatically. 2443 2444@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2445 2446Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2447be a unix domain socket backed one. The vhost-user uses a specifically defined 2448protocol to pass vhost ioctl replacement messages to an application on the other 2449end of the socket. On non-MSIX guests, the feature can be forced with 2450@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2451be created for multiqueue vhost-user. 2452 2453Example: 2454@example 2455qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2456 -numa node,memdev=mem \ 2457 -chardev socket,id=chr0,path=/path/to/socket \ 2458 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2459 -device virtio-net-pci,netdev=net0 2460@end example 2461 2462@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}] 2463Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default). 2464At most @var{len} bytes (64k by default) per packet are stored. The file format is 2465libpcap, so it can be analyzed with tools such as tcpdump or Wireshark. 2466Note: For devices created with '-netdev', use '-object filter-dump,...' instead. 2467 2468@item -net none 2469Indicate that no network devices should be configured. It is used to 2470override the default configuration (@option{-net nic -net user}) which 2471is activated if no @option{-net} options are provided. 2472ETEXI 2473 2474STEXI 2475@end table 2476ETEXI 2477DEFHEADING() 2478 2479DEFHEADING(Character device options) 2480STEXI 2481 2482The general form of a character device option is: 2483@table @option 2484ETEXI 2485 2486DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2487 "-chardev help\n" 2488 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2489 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2490 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n" 2491 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n" 2492 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n" 2493 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2494 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2495 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2496 " [,logfile=PATH][,logappend=on|off]\n" 2497 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2498 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2499 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2500 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2501 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2502 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2503#ifdef _WIN32 2504 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2505 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2506#else 2507 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2508 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2509#endif 2510#ifdef CONFIG_BRLAPI 2511 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2512#endif 2513#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2514 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2515 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2516 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2517#endif 2518#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2519 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2520 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2521#endif 2522#if defined(CONFIG_SPICE) 2523 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2524 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2525#endif 2526 , QEMU_ARCH_ALL 2527) 2528 2529STEXI 2530@item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}] 2531@findex -chardev 2532Backend is one of: 2533@option{null}, 2534@option{socket}, 2535@option{udp}, 2536@option{msmouse}, 2537@option{vc}, 2538@option{ringbuf}, 2539@option{file}, 2540@option{pipe}, 2541@option{console}, 2542@option{serial}, 2543@option{pty}, 2544@option{stdio}, 2545@option{braille}, 2546@option{tty}, 2547@option{parallel}, 2548@option{parport}, 2549@option{spicevmc}. 2550@option{spiceport}. 2551The specific backend will determine the applicable options. 2552 2553Use "-chardev help" to print all available chardev backend types. 2554 2555All devices must have an id, which can be any string up to 127 characters long. 2556It is used to uniquely identify this device in other command line directives. 2557 2558A character device may be used in multiplexing mode by multiple front-ends. 2559Specify @option{mux=on} to enable this mode. 2560A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2561backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2562If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2563create a multiplexer with your specified ID, and you can then configure multiple 2564front ends to use that chardev ID for their input/output. Up to four different 2565front ends can be connected to a single multiplexed chardev. (Without 2566multiplexing enabled, a chardev can only be used by a single front end.) 2567For instance you could use this to allow a single stdio chardev to be used by 2568two serial ports and the QEMU monitor: 2569 2570@example 2571-chardev stdio,mux=on,id=char0 \ 2572-mon chardev=char0,mode=readline \ 2573-serial chardev:char0 \ 2574-serial chardev:char0 2575@end example 2576 2577You can have more than one multiplexer in a system configuration; for instance 2578you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2579multiplexed between the QEMU monitor and a parallel port: 2580 2581@example 2582-chardev stdio,mux=on,id=char0 \ 2583-mon chardev=char0,mode=readline \ 2584-parallel chardev:char0 \ 2585-chardev tcp,...,mux=on,id=char1 \ 2586-serial chardev:char1 \ 2587-serial chardev:char1 2588@end example 2589 2590When you're using a multiplexed character device, some escape sequences are 2591interpreted in the input. @xref{mux_keys, Keys in the character backend 2592multiplexer}. 2593 2594Note that some other command line options may implicitly create multiplexed 2595character backends; for instance @option{-serial mon:stdio} creates a 2596multiplexed stdio backend connected to the serial port and the QEMU monitor, 2597and @option{-nographic} also multiplexes the console and the monitor to 2598stdio. 2599 2600There is currently no support for multiplexing in the other direction 2601(where a single QEMU front end takes input and output from multiple chardevs). 2602 2603Every backend supports the @option{logfile} option, which supplies the path 2604to a file to record all data transmitted via the backend. The @option{logappend} 2605option controls whether the log file will be truncated or appended to when 2606opened. 2607 2608Further options to each backend are described below. 2609 2610@item -chardev null ,id=@var{id} 2611A void device. This device will not emit any data, and will drop any data it 2612receives. The null backend does not take any options. 2613 2614@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}] 2615 2616Create a two-way stream socket, which can be either a TCP or a unix socket. A 2617unix socket will be created if @option{path} is specified. Behaviour is 2618undefined if TCP options are specified for a unix socket. 2619 2620@option{server} specifies that the socket shall be a listening socket. 2621 2622@option{nowait} specifies that QEMU should not block waiting for a client to 2623connect to a listening socket. 2624 2625@option{telnet} specifies that traffic on the socket should interpret telnet 2626escape sequences. 2627 2628@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2629the remote end goes away. qemu will delay this many seconds and then attempt 2630to reconnect. Zero disables reconnecting, and is the default. 2631 2632@option{tls-creds} requests enablement of the TLS protocol for encryption, 2633and specifies the id of the TLS credentials to use for the handshake. The 2634credentials must be previously created with the @option{-object tls-creds} 2635argument. 2636 2637TCP and unix socket options are given below: 2638 2639@table @option 2640 2641@item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay] 2642 2643@option{host} for a listening socket specifies the local address to be bound. 2644For a connecting socket species the remote host to connect to. @option{host} is 2645optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2646 2647@option{port} for a listening socket specifies the local port to be bound. For a 2648connecting socket specifies the port on the remote host to connect to. 2649@option{port} can be given as either a port number or a service name. 2650@option{port} is required. 2651 2652@option{to} is only relevant to listening sockets. If it is specified, and 2653@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2654to and including @option{to} until it succeeds. @option{to} must be specified 2655as a port number. 2656 2657@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2658If neither is specified the socket may use either protocol. 2659 2660@option{nodelay} disables the Nagle algorithm. 2661 2662@item unix options: path=@var{path} 2663 2664@option{path} specifies the local path of the unix socket. @option{path} is 2665required. 2666 2667@end table 2668 2669@item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6] 2670 2671Sends all traffic from the guest to a remote host over UDP. 2672 2673@option{host} specifies the remote host to connect to. If not specified it 2674defaults to @code{localhost}. 2675 2676@option{port} specifies the port on the remote host to connect to. @option{port} 2677is required. 2678 2679@option{localaddr} specifies the local address to bind to. If not specified it 2680defaults to @code{0.0.0.0}. 2681 2682@option{localport} specifies the local port to bind to. If not specified any 2683available local port will be used. 2684 2685@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2686If neither is specified the device may use either protocol. 2687 2688@item -chardev msmouse ,id=@var{id} 2689 2690Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2691take any options. 2692 2693@item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]] 2694 2695Connect to a QEMU text console. @option{vc} may optionally be given a specific 2696size. 2697 2698@option{width} and @option{height} specify the width and height respectively of 2699the console, in pixels. 2700 2701@option{cols} and @option{rows} specify that the console be sized to fit a text 2702console with the given dimensions. 2703 2704@item -chardev ringbuf ,id=@var{id} [,size=@var{size}] 2705 2706Create a ring buffer with fixed size @option{size}. 2707@var{size} must be a power of two and defaults to @code{64K}. 2708 2709@item -chardev file ,id=@var{id} ,path=@var{path} 2710 2711Log all traffic received from the guest to a file. 2712 2713@option{path} specifies the path of the file to be opened. This file will be 2714created if it does not already exist, and overwritten if it does. @option{path} 2715is required. 2716 2717@item -chardev pipe ,id=@var{id} ,path=@var{path} 2718 2719Create a two-way connection to the guest. The behaviour differs slightly between 2720Windows hosts and other hosts: 2721 2722On Windows, a single duplex pipe will be created at 2723@file{\\.pipe\@option{path}}. 2724 2725On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2726@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2727received by the guest. Data written by the guest can be read from 2728@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2729be present. 2730 2731@option{path} forms part of the pipe path as described above. @option{path} is 2732required. 2733 2734@item -chardev console ,id=@var{id} 2735 2736Send traffic from the guest to QEMU's standard output. @option{console} does not 2737take any options. 2738 2739@option{console} is only available on Windows hosts. 2740 2741@item -chardev serial ,id=@var{id} ,path=@option{path} 2742 2743Send traffic from the guest to a serial device on the host. 2744 2745On Unix hosts serial will actually accept any tty device, 2746not only serial lines. 2747 2748@option{path} specifies the name of the serial device to open. 2749 2750@item -chardev pty ,id=@var{id} 2751 2752Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2753not take any options. 2754 2755@option{pty} is not available on Windows hosts. 2756 2757@item -chardev stdio ,id=@var{id} [,signal=on|off] 2758Connect to standard input and standard output of the QEMU process. 2759 2760@option{signal} controls if signals are enabled on the terminal, that includes 2761exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2762default, use @option{signal=off} to disable it. 2763 2764@item -chardev braille ,id=@var{id} 2765 2766Connect to a local BrlAPI server. @option{braille} does not take any options. 2767 2768@item -chardev tty ,id=@var{id} ,path=@var{path} 2769 2770@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 2771DragonFlyBSD hosts. It is an alias for @option{serial}. 2772 2773@option{path} specifies the path to the tty. @option{path} is required. 2774 2775@item -chardev parallel ,id=@var{id} ,path=@var{path} 2776@itemx -chardev parport ,id=@var{id} ,path=@var{path} 2777 2778@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 2779 2780Connect to a local parallel port. 2781 2782@option{path} specifies the path to the parallel port device. @option{path} is 2783required. 2784 2785@item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2786 2787@option{spicevmc} is only available when spice support is built in. 2788 2789@option{debug} debug level for spicevmc 2790 2791@option{name} name of spice channel to connect to 2792 2793Connect to a spice virtual machine channel, such as vdiport. 2794 2795@item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2796 2797@option{spiceport} is only available when spice support is built in. 2798 2799@option{debug} debug level for spicevmc 2800 2801@option{name} name of spice port to connect to 2802 2803Connect to a spice port, allowing a Spice client to handle the traffic 2804identified by a name (preferably a fqdn). 2805ETEXI 2806 2807STEXI 2808@end table 2809ETEXI 2810DEFHEADING() 2811 2812DEFHEADING(Device URL Syntax) 2813STEXI 2814 2815In addition to using normal file images for the emulated storage devices, 2816QEMU can also use networked resources such as iSCSI devices. These are 2817specified using a special URL syntax. 2818 2819@table @option 2820@item iSCSI 2821iSCSI support allows QEMU to access iSCSI resources directly and use as 2822images for the guest storage. Both disk and cdrom images are supported. 2823 2824Syntax for specifying iSCSI LUNs is 2825``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>'' 2826 2827By default qemu will use the iSCSI initiator-name 2828'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command 2829line or a configuration file. 2830 2831Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect 2832stalled requests and force a reestablishment of the session. The timeout 2833is specified in seconds. The default is 0 which means no timeout. Libiscsi 28341.15.0 or greater is required for this feature. 2835 2836Example (without authentication): 2837@example 2838qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \ 2839 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \ 2840 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2841@end example 2842 2843Example (CHAP username/password via URL): 2844@example 2845qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1 2846@end example 2847 2848Example (CHAP username/password via environment variables): 2849@example 2850LIBISCSI_CHAP_USERNAME="user" \ 2851LIBISCSI_CHAP_PASSWORD="password" \ 2852qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2853@end example 2854 2855iSCSI support is an optional feature of QEMU and only available when 2856compiled and linked against libiscsi. 2857ETEXI 2858DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 2859 "-iscsi [user=user][,password=password]\n" 2860 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 2861 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 2862 " [,timeout=timeout]\n" 2863 " iSCSI session parameters\n", QEMU_ARCH_ALL) 2864STEXI 2865 2866iSCSI parameters such as username and password can also be specified via 2867a configuration file. See qemu-doc for more information and examples. 2868 2869@item NBD 2870QEMU supports NBD (Network Block Devices) both using TCP protocol as well 2871as Unix Domain Sockets. 2872 2873Syntax for specifying a NBD device using TCP 2874``nbd:<server-ip>:<port>[:exportname=<export>]'' 2875 2876Syntax for specifying a NBD device using Unix Domain Sockets 2877``nbd:unix:<domain-socket>[:exportname=<export>]'' 2878 2879 2880Example for TCP 2881@example 2882qemu-system-i386 --drive file=nbd:192.0.2.1:30000 2883@end example 2884 2885Example for Unix Domain Sockets 2886@example 2887qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket 2888@end example 2889 2890@item SSH 2891QEMU supports SSH (Secure Shell) access to remote disks. 2892 2893Examples: 2894@example 2895qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img 2896qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img 2897@end example 2898 2899Currently authentication must be done using ssh-agent. Other 2900authentication methods may be supported in future. 2901 2902@item Sheepdog 2903Sheepdog is a distributed storage system for QEMU. 2904QEMU supports using either local sheepdog devices or remote networked 2905devices. 2906 2907Syntax for specifying a sheepdog device 2908@example 2909sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag] 2910@end example 2911 2912Example 2913@example 2914qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine 2915@end example 2916 2917See also @url{https://sheepdog.github.io/sheepdog/}. 2918 2919@item GlusterFS 2920GlusterFS is a user space distributed file system. 2921QEMU supports the use of GlusterFS volumes for hosting VM disk images using 2922TCP, Unix Domain Sockets and RDMA transport protocols. 2923 2924Syntax for specifying a VM disk image on GlusterFS volume is 2925@example 2926 2927URI: 2928gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...] 2929 2930JSON: 2931'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...", 2932@ "server":[@{"type":"tcp","host":"...","port":"..."@}, 2933@ @{"type":"unix","socket":"..."@}]@}@}' 2934@end example 2935 2936 2937Example 2938@example 2939URI: 2940qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img, 2941@ file.debug=9,file.logfile=/var/log/qemu-gluster.log 2942 2943JSON: 2944qemu-system-x86_64 'json:@{"driver":"qcow2", 2945@ "file":@{"driver":"gluster", 2946@ "volume":"testvol","path":"a.img", 2947@ "debug":9,"logfile":"/var/log/qemu-gluster.log", 2948@ "server":[@{"type":"tcp","host":"1.2.3.4","port":24007@}, 2949@ @{"type":"unix","socket":"/var/run/glusterd.socket"@}]@}@}' 2950qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img, 2951@ file.debug=9,file.logfile=/var/log/qemu-gluster.log, 2952@ file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007, 2953@ file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket 2954@end example 2955 2956See also @url{http://www.gluster.org}. 2957 2958@item HTTP/HTTPS/FTP/FTPS 2959QEMU supports read-only access to files accessed over http(s) and ftp(s). 2960 2961Syntax using a single filename: 2962@example 2963<protocol>://[<username>[:<password>]@@]<host>/<path> 2964@end example 2965 2966where: 2967@table @option 2968@item protocol 2969'http', 'https', 'ftp', or 'ftps'. 2970 2971@item username 2972Optional username for authentication to the remote server. 2973 2974@item password 2975Optional password for authentication to the remote server. 2976 2977@item host 2978Address of the remote server. 2979 2980@item path 2981Path on the remote server, including any query string. 2982@end table 2983 2984The following options are also supported: 2985@table @option 2986@item url 2987The full URL when passing options to the driver explicitly. 2988 2989@item readahead 2990The amount of data to read ahead with each range request to the remote server. 2991This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it 2992does not have a suffix, it will be assumed to be in bytes. The value must be a 2993multiple of 512 bytes. It defaults to 256k. 2994 2995@item sslverify 2996Whether to verify the remote server's certificate when connecting over SSL. It 2997can have the value 'on' or 'off'. It defaults to 'on'. 2998 2999@item cookie 3000Send this cookie (it can also be a list of cookies separated by ';') with 3001each outgoing request. Only supported when using protocols such as HTTP 3002which support cookies, otherwise ignored. 3003 3004@item timeout 3005Set the timeout in seconds of the CURL connection. This timeout is the time 3006that CURL waits for a response from the remote server to get the size of the 3007image to be downloaded. If not set, the default timeout of 5 seconds is used. 3008@end table 3009 3010Note that when passing options to qemu explicitly, @option{driver} is the value 3011of <protocol>. 3012 3013Example: boot from a remote Fedora 20 live ISO image 3014@example 3015qemu-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 3016 3017qemu-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 3018@end example 3019 3020Example: boot from a remote Fedora 20 cloud image using a local overlay for 3021writes, copy-on-read, and a readahead of 64k 3022@example 3023qemu-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 3024 3025qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on 3026@end example 3027 3028Example: boot from an image stored on a VMware vSphere server with a self-signed 3029certificate using a local overlay for writes, a readahead of 64k and a timeout 3030of 10 seconds. 3031@example 3032qemu-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 3033 3034qemu-system-x86_64 -drive file=/tmp/test.qcow2 3035@end example 3036ETEXI 3037 3038STEXI 3039@end table 3040ETEXI 3041 3042DEFHEADING(Bluetooth(R) options) 3043STEXI 3044@table @option 3045ETEXI 3046 3047DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 3048 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 3049 "-bt hci,host[:id]\n" \ 3050 " use host's HCI with the given name\n" \ 3051 "-bt hci[,vlan=n]\n" \ 3052 " emulate a standard HCI in virtual scatternet 'n'\n" \ 3053 "-bt vhci[,vlan=n]\n" \ 3054 " add host computer to virtual scatternet 'n' using VHCI\n" \ 3055 "-bt device:dev[,vlan=n]\n" \ 3056 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 3057 QEMU_ARCH_ALL) 3058STEXI 3059@item -bt hci[...] 3060@findex -bt 3061Defines the function of the corresponding Bluetooth HCI. -bt options 3062are matched with the HCIs present in the chosen machine type. For 3063example when emulating a machine with only one HCI built into it, only 3064the first @code{-bt hci[...]} option is valid and defines the HCI's 3065logic. The Transport Layer is decided by the machine type. Currently 3066the machines @code{n800} and @code{n810} have one HCI and all other 3067machines have none. 3068 3069@anchor{bt-hcis} 3070The following three types are recognized: 3071 3072@table @option 3073@item -bt hci,null 3074(default) The corresponding Bluetooth HCI assumes no internal logic 3075and will not respond to any HCI commands or emit events. 3076 3077@item -bt hci,host[:@var{id}] 3078(@code{bluez} only) The corresponding HCI passes commands / events 3079to / from the physical HCI identified by the name @var{id} (default: 3080@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 3081capable systems like Linux. 3082 3083@item -bt hci[,vlan=@var{n}] 3084Add a virtual, standard HCI that will participate in the Bluetooth 3085scatternet @var{n} (default @code{0}). Similarly to @option{-net} 3086VLANs, devices inside a bluetooth network @var{n} can only communicate 3087with other devices in the same network (scatternet). 3088@end table 3089 3090@item -bt vhci[,vlan=@var{n}] 3091(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 3092to the host bluetooth stack instead of to the emulated target. This 3093allows the host and target machines to participate in a common scatternet 3094and communicate. Requires the Linux @code{vhci} driver installed. Can 3095be used as following: 3096 3097@example 3098qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 3099@end example 3100 3101@item -bt device:@var{dev}[,vlan=@var{n}] 3102Emulate a bluetooth device @var{dev} and place it in network @var{n} 3103(default @code{0}). QEMU can only emulate one type of bluetooth devices 3104currently: 3105 3106@table @option 3107@item keyboard 3108Virtual wireless keyboard implementing the HIDP bluetooth profile. 3109@end table 3110ETEXI 3111 3112STEXI 3113@end table 3114ETEXI 3115DEFHEADING() 3116 3117#ifdef CONFIG_TPM 3118DEFHEADING(TPM device options) 3119 3120DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3121 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3122 " use path to provide path to a character device; default is /dev/tpm0\n" 3123 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3124 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3125 "-tpmdev emulator,id=id,chardev=dev\n" 3126 " configure the TPM device using chardev backend\n", 3127 QEMU_ARCH_ALL) 3128STEXI 3129 3130The general form of a TPM device option is: 3131@table @option 3132 3133@item -tpmdev @var{backend} ,id=@var{id} [,@var{options}] 3134@findex -tpmdev 3135Backend type must be either one of the following: 3136@option{passthrough}, @option{emulator}. 3137 3138The specific backend type will determine the applicable options. 3139The @code{-tpmdev} option creates the TPM backend and requires a 3140@code{-device} option that specifies the TPM frontend interface model. 3141 3142Options to each backend are described below. 3143 3144Use 'help' to print all available TPM backend types. 3145@example 3146qemu -tpmdev help 3147@end example 3148 3149@item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path} 3150 3151(Linux-host only) Enable access to the host's TPM using the passthrough 3152driver. 3153 3154@option{path} specifies the path to the host's TPM device, i.e., on 3155a Linux host this would be @code{/dev/tpm0}. 3156@option{path} is optional and by default @code{/dev/tpm0} is used. 3157 3158@option{cancel-path} specifies the path to the host TPM device's sysfs 3159entry allowing for cancellation of an ongoing TPM command. 3160@option{cancel-path} is optional and by default QEMU will search for the 3161sysfs entry to use. 3162 3163Some notes about using the host's TPM with the passthrough driver: 3164 3165The TPM device accessed by the passthrough driver must not be 3166used by any other application on the host. 3167 3168Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3169the VM's firmware (BIOS/UEFI) will not be able to initialize the 3170TPM again and may therefore not show a TPM-specific menu that would 3171otherwise allow the user to configure the TPM, e.g., allow the user to 3172enable/disable or activate/deactivate the TPM. 3173Further, if TPM ownership is released from within a VM then the host's TPM 3174will get disabled and deactivated. To enable and activate the 3175TPM again afterwards, the host has to be rebooted and the user is 3176required to enter the firmware's menu to enable and activate the TPM. 3177If the TPM is left disabled and/or deactivated most TPM commands will fail. 3178 3179To create a passthrough TPM use the following two options: 3180@example 3181-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3182@end example 3183Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3184@code{tpmdev=tpm0} in the device option. 3185 3186@item -tpmdev emulator, id=@var{id}, chardev=@var{dev} 3187 3188(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3189chardev backend. 3190 3191@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3192 3193To create a TPM emulator backend device with chardev socket backend: 3194@example 3195 3196-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3197 3198@end example 3199 3200@end table 3201 3202ETEXI 3203 3204DEFHEADING() 3205 3206#endif 3207 3208DEFHEADING(Linux/Multiboot boot specific) 3209STEXI 3210 3211When using these options, you can use a given Linux or Multiboot 3212kernel without installing it in the disk image. It can be useful 3213for easier testing of various kernels. 3214 3215@table @option 3216ETEXI 3217 3218DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3219 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3220STEXI 3221@item -kernel @var{bzImage} 3222@findex -kernel 3223Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3224or in multiboot format. 3225ETEXI 3226 3227DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3228 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3229STEXI 3230@item -append @var{cmdline} 3231@findex -append 3232Use @var{cmdline} as kernel command line 3233ETEXI 3234 3235DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3236 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3237STEXI 3238@item -initrd @var{file} 3239@findex -initrd 3240Use @var{file} as initial ram disk. 3241 3242@item -initrd "@var{file1} arg=foo,@var{file2}" 3243 3244This syntax is only available with multiboot. 3245 3246Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3247first module. 3248ETEXI 3249 3250DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3251 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3252STEXI 3253@item -dtb @var{file} 3254@findex -dtb 3255Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3256on boot. 3257ETEXI 3258 3259STEXI 3260@end table 3261ETEXI 3262DEFHEADING() 3263 3264DEFHEADING(Debug/Expert options) 3265STEXI 3266@table @option 3267ETEXI 3268 3269DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3270 "-fw_cfg [name=]<name>,file=<file>\n" 3271 " add named fw_cfg entry with contents from file\n" 3272 "-fw_cfg [name=]<name>,string=<str>\n" 3273 " add named fw_cfg entry with contents from string\n", 3274 QEMU_ARCH_ALL) 3275STEXI 3276 3277@item -fw_cfg [name=]@var{name},file=@var{file} 3278@findex -fw_cfg 3279Add named fw_cfg entry with contents from file @var{file}. 3280 3281@item -fw_cfg [name=]@var{name},string=@var{str} 3282Add named fw_cfg entry with contents from string @var{str}. 3283 3284The terminating NUL character of the contents of @var{str} will not be 3285included as part of the fw_cfg item data. To insert contents with 3286embedded NUL characters, you have to use the @var{file} parameter. 3287 3288The fw_cfg entries are passed by QEMU through to the guest. 3289 3290Example: 3291@example 3292 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3293@end example 3294creates an fw_cfg entry named opt/com.mycompany/blob with contents 3295from ./my_blob.bin. 3296 3297ETEXI 3298 3299DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3300 "-serial dev redirect the serial port to char device 'dev'\n", 3301 QEMU_ARCH_ALL) 3302STEXI 3303@item -serial @var{dev} 3304@findex -serial 3305Redirect the virtual serial port to host character device 3306@var{dev}. The default device is @code{vc} in graphical mode and 3307@code{stdio} in non graphical mode. 3308 3309This option can be used several times to simulate up to 4 serial 3310ports. 3311 3312Use @code{-serial none} to disable all serial ports. 3313 3314Available character devices are: 3315@table @option 3316@item vc[:@var{W}x@var{H}] 3317Virtual console. Optionally, a width and height can be given in pixel with 3318@example 3319vc:800x600 3320@end example 3321It is also possible to specify width or height in characters: 3322@example 3323vc:80Cx24C 3324@end example 3325@item pty 3326[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3327@item none 3328No device is allocated. 3329@item null 3330void device 3331@item chardev:@var{id} 3332Use a named character device defined with the @code{-chardev} option. 3333@item /dev/XXX 3334[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3335parameters are set according to the emulated ones. 3336@item /dev/parport@var{N} 3337[Linux only, parallel port only] Use host parallel port 3338@var{N}. Currently SPP and EPP parallel port features can be used. 3339@item file:@var{filename} 3340Write output to @var{filename}. No character can be read. 3341@item stdio 3342[Unix only] standard input/output 3343@item pipe:@var{filename} 3344name pipe @var{filename} 3345@item COM@var{n} 3346[Windows only] Use host serial port @var{n} 3347@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3348This implements UDP Net Console. 3349When @var{remote_host} or @var{src_ip} are not specified 3350they default to @code{0.0.0.0}. 3351When not using a specified @var{src_port} a random port is automatically chosen. 3352 3353If you just want a simple readonly console you can use @code{netcat} or 3354@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3355@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3356will appear in the netconsole session. 3357 3358If you plan to send characters back via netconsole or you want to stop 3359and start QEMU a lot of times, you should have QEMU use the same 3360source port each time by using something like @code{-serial 3361udp::4555@@:4556} to QEMU. Another approach is to use a patched 3362version of netcat which can listen to a TCP port and send and receive 3363characters via udp. If you have a patched version of netcat which 3364activates telnet remote echo and single char transfer, then you can 3365use the following options to set up a netcat redirector to allow 3366telnet on port 5555 to access the QEMU port. 3367@table @code 3368@item QEMU Options: 3369-serial udp::4555@@:4556 3370@item netcat options: 3371-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3372@item telnet options: 3373localhost 5555 3374@end table 3375 3376@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3377The TCP Net Console has two modes of operation. It can send the serial 3378I/O to a location or wait for a connection from a location. By default 3379the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3380the @var{server} option QEMU will wait for a client socket application 3381to connect to the port before continuing, unless the @code{nowait} 3382option was specified. The @code{nodelay} option disables the Nagle buffering 3383algorithm. The @code{reconnect} option only applies if @var{noserver} is 3384set, if the connection goes down it will attempt to reconnect at the 3385given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3386one TCP connection at a time is accepted. You can use @code{telnet} to 3387connect to the corresponding character device. 3388@table @code 3389@item Example to send tcp console to 192.168.0.2 port 4444 3390-serial tcp:192.168.0.2:4444 3391@item Example to listen and wait on port 4444 for connection 3392-serial tcp::4444,server 3393@item Example to not wait and listen on ip 192.168.0.100 port 4444 3394-serial tcp:192.168.0.100:4444,server,nowait 3395@end table 3396 3397@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3398The telnet protocol is used instead of raw tcp sockets. The options 3399work the same as if you had specified @code{-serial tcp}. The 3400difference is that the port acts like a telnet server or client using 3401telnet option negotiation. This will also allow you to send the 3402MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3403sequence. Typically in unix telnet you do it with Control-] and then 3404type "send break" followed by pressing the enter key. 3405 3406@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3407A unix domain socket is used instead of a tcp socket. The option works the 3408same as if you had specified @code{-serial tcp} except the unix domain socket 3409@var{path} is used for connections. 3410 3411@item mon:@var{dev_string} 3412This is a special option to allow the monitor to be multiplexed onto 3413another serial port. The monitor is accessed with key sequence of 3414@key{Control-a} and then pressing @key{c}. 3415@var{dev_string} should be any one of the serial devices specified 3416above. An example to multiplex the monitor onto a telnet server 3417listening on port 4444 would be: 3418@table @code 3419@item -serial mon:telnet::4444,server,nowait 3420@end table 3421When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3422QEMU any more but will be passed to the guest instead. 3423 3424@item braille 3425Braille device. This will use BrlAPI to display the braille output on a real 3426or fake device. 3427 3428@item msmouse 3429Three button serial mouse. Configure the guest to use Microsoft protocol. 3430@end table 3431ETEXI 3432 3433DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3434 "-parallel dev redirect the parallel port to char device 'dev'\n", 3435 QEMU_ARCH_ALL) 3436STEXI 3437@item -parallel @var{dev} 3438@findex -parallel 3439Redirect the virtual parallel port to host device @var{dev} (same 3440devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3441be used to use hardware devices connected on the corresponding host 3442parallel port. 3443 3444This option can be used several times to simulate up to 3 parallel 3445ports. 3446 3447Use @code{-parallel none} to disable all parallel ports. 3448ETEXI 3449 3450DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3451 "-monitor dev redirect the monitor to char device 'dev'\n", 3452 QEMU_ARCH_ALL) 3453STEXI 3454@item -monitor @var{dev} 3455@findex -monitor 3456Redirect the monitor to host device @var{dev} (same devices as the 3457serial port). 3458The default device is @code{vc} in graphical mode and @code{stdio} in 3459non graphical mode. 3460Use @code{-monitor none} to disable the default monitor. 3461ETEXI 3462DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3463 "-qmp dev like -monitor but opens in 'control' mode\n", 3464 QEMU_ARCH_ALL) 3465STEXI 3466@item -qmp @var{dev} 3467@findex -qmp 3468Like -monitor but opens in 'control' mode. 3469ETEXI 3470DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3471 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3472 QEMU_ARCH_ALL) 3473STEXI 3474@item -qmp-pretty @var{dev} 3475@findex -qmp-pretty 3476Like -qmp but uses pretty JSON formatting. 3477ETEXI 3478 3479DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3480 "-mon [chardev=]name[,mode=readline|control]\n", QEMU_ARCH_ALL) 3481STEXI 3482@item -mon [chardev=]name[,mode=readline|control] 3483@findex -mon 3484Setup monitor on chardev @var{name}. 3485ETEXI 3486 3487DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3488 "-debugcon dev redirect the debug console to char device 'dev'\n", 3489 QEMU_ARCH_ALL) 3490STEXI 3491@item -debugcon @var{dev} 3492@findex -debugcon 3493Redirect the debug console to host device @var{dev} (same devices as the 3494serial port). The debug console is an I/O port which is typically port 34950xe9; writing to that I/O port sends output to this device. 3496The default device is @code{vc} in graphical mode and @code{stdio} in 3497non graphical mode. 3498ETEXI 3499 3500DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3501 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3502STEXI 3503@item -pidfile @var{file} 3504@findex -pidfile 3505Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3506from a script. 3507ETEXI 3508 3509DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3510 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3511STEXI 3512@item -singlestep 3513@findex -singlestep 3514Run the emulation in single step mode. 3515ETEXI 3516 3517DEF("S", 0, QEMU_OPTION_S, \ 3518 "-S freeze CPU at startup (use 'c' to start execution)\n", 3519 QEMU_ARCH_ALL) 3520STEXI 3521@item -S 3522@findex -S 3523Do not start CPU at startup (you must type 'c' in the monitor). 3524ETEXI 3525 3526DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3527 "-realtime [mlock=on|off]\n" 3528 " run qemu with realtime features\n" 3529 " mlock=on|off controls mlock support (default: on)\n", 3530 QEMU_ARCH_ALL) 3531STEXI 3532@item -realtime mlock=on|off 3533@findex -realtime 3534Run qemu with realtime features. 3535mlocking qemu and guest memory can be enabled via @option{mlock=on} 3536(enabled by default). 3537ETEXI 3538 3539DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3540 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3541STEXI 3542@item -gdb @var{dev} 3543@findex -gdb 3544Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3545connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3546stdio are reasonable use case. The latter is allowing to start QEMU from 3547within gdb and establish the connection via a pipe: 3548@example 3549(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 3550@end example 3551ETEXI 3552 3553DEF("s", 0, QEMU_OPTION_s, \ 3554 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3555 QEMU_ARCH_ALL) 3556STEXI 3557@item -s 3558@findex -s 3559Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3560(@pxref{gdb_usage}). 3561ETEXI 3562 3563DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3564 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3565 QEMU_ARCH_ALL) 3566STEXI 3567@item -d @var{item1}[,...] 3568@findex -d 3569Enable logging of specified items. Use '-d help' for a list of log items. 3570ETEXI 3571 3572DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3573 "-D logfile output log to logfile (default stderr)\n", 3574 QEMU_ARCH_ALL) 3575STEXI 3576@item -D @var{logfile} 3577@findex -D 3578Output log in @var{logfile} instead of to stderr 3579ETEXI 3580 3581DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3582 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3583 QEMU_ARCH_ALL) 3584STEXI 3585@item -dfilter @var{range1}[,...] 3586@findex -dfilter 3587Filter debug output to that relevant to a range of target addresses. The filter 3588spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3589@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3590addresses and sizes required. For example: 3591@example 3592 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3593@end example 3594Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3595the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3596block starting at 0xffffffc00005f000. 3597ETEXI 3598 3599DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3600 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3601 QEMU_ARCH_ALL) 3602STEXI 3603@item -L @var{path} 3604@findex -L 3605Set the directory for the BIOS, VGA BIOS and keymaps. 3606 3607To list all the data directories, use @code{-L help}. 3608ETEXI 3609 3610DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3611 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3612STEXI 3613@item -bios @var{file} 3614@findex -bios 3615Set the filename for the BIOS. 3616ETEXI 3617 3618DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3619 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3620STEXI 3621@item -enable-kvm 3622@findex -enable-kvm 3623Enable KVM full virtualization support. This option is only available 3624if KVM support is enabled when compiling. 3625ETEXI 3626 3627DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \ 3628 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386) 3629STEXI 3630@item -enable-hax 3631@findex -enable-hax 3632Enable HAX (Hardware-based Acceleration eXecution) support. This option 3633is only available if HAX support is enabled when compiling. HAX is only 3634applicable to MAC and Windows platform, and thus does not conflict with 3635KVM. 3636ETEXI 3637 3638DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3639 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3640DEF("xen-create", 0, QEMU_OPTION_xen_create, 3641 "-xen-create create domain using xen hypercalls, bypassing xend\n" 3642 " warning: should not be used when xend is in use\n", 3643 QEMU_ARCH_ALL) 3644DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3645 "-xen-attach attach to existing xen domain\n" 3646 " xend will use this when starting QEMU\n", 3647 QEMU_ARCH_ALL) 3648DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3649 "-xen-domid-restrict restrict set of available xen operations\n" 3650 " to specified domain id. (Does not affect\n" 3651 " xenpv machine type).\n", 3652 QEMU_ARCH_ALL) 3653STEXI 3654@item -xen-domid @var{id} 3655@findex -xen-domid 3656Specify xen guest domain @var{id} (XEN only). 3657@item -xen-create 3658@findex -xen-create 3659Create domain using xen hypercalls, bypassing xend. 3660Warning: should not be used when xend is in use (XEN only). 3661@item -xen-attach 3662@findex -xen-attach 3663Attach to existing xen domain. 3664xend will use this when starting QEMU (XEN only). 3665@findex -xen-domid-restrict 3666Restrict set of available xen operations to specified domain id (XEN only). 3667ETEXI 3668 3669DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3670 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3671STEXI 3672@item -no-reboot 3673@findex -no-reboot 3674Exit instead of rebooting. 3675ETEXI 3676 3677DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3678 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3679STEXI 3680@item -no-shutdown 3681@findex -no-shutdown 3682Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3683This allows for instance switching to monitor to commit changes to the 3684disk image. 3685ETEXI 3686 3687DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3688 "-loadvm [tag|id]\n" \ 3689 " start right away with a saved state (loadvm in monitor)\n", 3690 QEMU_ARCH_ALL) 3691STEXI 3692@item -loadvm @var{file} 3693@findex -loadvm 3694Start right away with a saved state (@code{loadvm} in monitor) 3695ETEXI 3696 3697#ifndef _WIN32 3698DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3699 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3700#endif 3701STEXI 3702@item -daemonize 3703@findex -daemonize 3704Daemonize the QEMU process after initialization. QEMU will not detach from 3705standard IO until it is ready to receive connections on any of its devices. 3706This option is a useful way for external programs to launch QEMU without having 3707to cope with initialization race conditions. 3708ETEXI 3709 3710DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3711 "-option-rom rom load a file, rom, into the option ROM space\n", 3712 QEMU_ARCH_ALL) 3713STEXI 3714@item -option-rom @var{file} 3715@findex -option-rom 3716Load the contents of @var{file} as an option ROM. 3717This option is useful to load things like EtherBoot. 3718ETEXI 3719 3720HXCOMM Silently ignored for compatibility 3721DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL) 3722 3723HXCOMM Options deprecated by -rtc 3724DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL) 3725DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL) 3726 3727DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3728 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3729 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3730 QEMU_ARCH_ALL) 3731 3732STEXI 3733 3734@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew] 3735@findex -rtc 3736Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3737UTC or local time, respectively. @code{localtime} is required for correct date in 3738MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the 3739format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3740 3741By default the RTC is driven by the host system time. This allows using of the 3742RTC as accurate reference clock inside the guest, specifically if the host 3743time is smoothly following an accurate external reference clock, e.g. via NTP. 3744If you want to isolate the guest time from the host, you can set @option{clock} 3745to @code{rt} instead. To even prevent it from progressing during suspension, 3746you can set it to @code{vm}. 3747 3748Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3749specifically with Windows' ACPI HAL. This option will try to figure out how 3750many timer interrupts were not processed by the Windows guest and will 3751re-inject them. 3752ETEXI 3753 3754DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3755 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3756 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3757 " instruction, enable aligning the host and virtual clocks\n" \ 3758 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3759STEXI 3760@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3761@findex -icount 3762Enable virtual instruction counter. The virtual cpu will execute one 3763instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3764then the virtual cpu speed will be automatically adjusted to keep virtual 3765time within a few seconds of real time. 3766 3767When the virtual cpu is sleeping, the virtual time will advance at default 3768speed unless @option{sleep=on|off} is specified. 3769With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3770instantly whenever the virtual cpu goes to sleep mode and will not advance 3771if no timer is enabled. This behavior give deterministic execution times from 3772the guest point of view. 3773 3774Note that while this option can give deterministic behavior, it does not 3775provide cycle accurate emulation. Modern CPUs contain superscalar out of 3776order cores with complex cache hierarchies. The number of instructions 3777executed often has little or no correlation with actual performance. 3778 3779@option{align=on} will activate the delay algorithm which will try 3780to synchronise the host clock and the virtual clock. The goal is to 3781have a guest running at the real frequency imposed by the shift option. 3782Whenever the guest clock is behind the host clock and if 3783@option{align=on} is specified then we print a message to the user 3784to inform about the delay. 3785Currently this option does not work when @option{shift} is @code{auto}. 3786Note: The sync algorithm will work for those shift values for which 3787the guest clock runs ahead of the host clock. Typically this happens 3788when the shift value is high (how high depends on the host machine). 3789 3790When @option{rr} option is specified deterministic record/replay is enabled. 3791Replay log is written into @var{filename} file in record mode and 3792read from this file in replay mode. 3793 3794Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3795at the start of execution recording. In replay mode this option is used 3796to load the initial VM state. 3797ETEXI 3798 3799DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3800 "-watchdog model\n" \ 3801 " enable virtual hardware watchdog [default=none]\n", 3802 QEMU_ARCH_ALL) 3803STEXI 3804@item -watchdog @var{model} 3805@findex -watchdog 3806Create a virtual hardware watchdog device. Once enabled (by a guest 3807action), the watchdog must be periodically polled by an agent inside 3808the guest or else the guest will be restarted. Choose a model for 3809which your guest has drivers. 3810 3811The @var{model} is the model of hardware watchdog to emulate. Use 3812@code{-watchdog help} to list available hardware models. Only one 3813watchdog can be enabled for a guest. 3814 3815The following models may be available: 3816@table @option 3817@item ib700 3818iBASE 700 is a very simple ISA watchdog with a single timer. 3819@item i6300esb 3820Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3821dual-timer watchdog. 3822@item diag288 3823A virtual watchdog for s390x backed by the diagnose 288 hypercall 3824(currently KVM only). 3825@end table 3826ETEXI 3827 3828DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3829 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \ 3830 " action when watchdog fires [default=reset]\n", 3831 QEMU_ARCH_ALL) 3832STEXI 3833@item -watchdog-action @var{action} 3834@findex -watchdog-action 3835 3836The @var{action} controls what QEMU will do when the watchdog timer 3837expires. 3838The default is 3839@code{reset} (forcefully reset the guest). 3840Other possible actions are: 3841@code{shutdown} (attempt to gracefully shutdown the guest), 3842@code{poweroff} (forcefully poweroff the guest), 3843@code{pause} (pause the guest), 3844@code{debug} (print a debug message and continue), or 3845@code{none} (do nothing). 3846 3847Note that the @code{shutdown} action requires that the guest responds 3848to ACPI signals, which it may not be able to do in the sort of 3849situations where the watchdog would have expired, and thus 3850@code{-watchdog-action shutdown} is not recommended for production use. 3851 3852Examples: 3853 3854@table @code 3855@item -watchdog i6300esb -watchdog-action pause 3856@itemx -watchdog ib700 3857@end table 3858ETEXI 3859 3860DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3861 "-echr chr set terminal escape character instead of ctrl-a\n", 3862 QEMU_ARCH_ALL) 3863STEXI 3864 3865@item -echr @var{numeric_ascii_value} 3866@findex -echr 3867Change the escape character used for switching to the monitor when using 3868monitor and serial sharing. The default is @code{0x01} when using the 3869@code{-nographic} option. @code{0x01} is equal to pressing 3870@code{Control-a}. You can select a different character from the ascii 3871control keys where 1 through 26 map to Control-a through Control-z. For 3872instance you could use the either of the following to change the escape 3873character to Control-t. 3874@table @code 3875@item -echr 0x14 3876@itemx -echr 20 3877@end table 3878ETEXI 3879 3880DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \ 3881 "-virtioconsole c\n" \ 3882 " set virtio console\n", QEMU_ARCH_ALL) 3883STEXI 3884@item -virtioconsole @var{c} 3885@findex -virtioconsole 3886Set virtio console. 3887 3888This option is maintained for backward compatibility. 3889 3890Please use @code{-device virtconsole} for the new way of invocation. 3891ETEXI 3892 3893DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3894 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3895STEXI 3896@item -show-cursor 3897@findex -show-cursor 3898Show cursor. 3899ETEXI 3900 3901DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3902 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3903STEXI 3904@item -tb-size @var{n} 3905@findex -tb-size 3906Set TB size. 3907ETEXI 3908 3909DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3910 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3911 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3912 "-incoming unix:socketpath\n" \ 3913 " prepare for incoming migration, listen on\n" \ 3914 " specified protocol and socket address\n" \ 3915 "-incoming fd:fd\n" \ 3916 "-incoming exec:cmdline\n" \ 3917 " accept incoming migration on given file descriptor\n" \ 3918 " or from given external command\n" \ 3919 "-incoming defer\n" \ 3920 " wait for the URI to be specified via migrate_incoming\n", 3921 QEMU_ARCH_ALL) 3922STEXI 3923@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3924@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3925@findex -incoming 3926Prepare for incoming migration, listen on a given tcp port. 3927 3928@item -incoming unix:@var{socketpath} 3929Prepare for incoming migration, listen on a given unix socket. 3930 3931@item -incoming fd:@var{fd} 3932Accept incoming migration from a given filedescriptor. 3933 3934@item -incoming exec:@var{cmdline} 3935Accept incoming migration as an output from specified external command. 3936 3937@item -incoming defer 3938Wait for the URI to be specified via migrate_incoming. The monitor can 3939be used to change settings (such as migration parameters) prior to issuing 3940the migrate_incoming to allow the migration to begin. 3941ETEXI 3942 3943DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3944 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3945STEXI 3946@item -only-migratable 3947@findex -only-migratable 3948Only allow migratable devices. Devices will not be allowed to enter an 3949unmigratable state. 3950ETEXI 3951 3952DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3953 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3954STEXI 3955@item -nodefaults 3956@findex -nodefaults 3957Don't create default devices. Normally, QEMU sets the default devices like serial 3958port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3959CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3960default devices. 3961ETEXI 3962 3963#ifndef _WIN32 3964DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3965 "-chroot dir chroot to dir just before starting the VM\n", 3966 QEMU_ARCH_ALL) 3967#endif 3968STEXI 3969@item -chroot @var{dir} 3970@findex -chroot 3971Immediately before starting guest execution, chroot to the specified 3972directory. Especially useful in combination with -runas. 3973ETEXI 3974 3975#ifndef _WIN32 3976DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3977 "-runas user change to user id user just before starting the VM\n", 3978 QEMU_ARCH_ALL) 3979#endif 3980STEXI 3981@item -runas @var{user} 3982@findex -runas 3983Immediately before starting guest execution, drop root privileges, switching 3984to the specified user. 3985ETEXI 3986 3987DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 3988 "-prom-env variable=value\n" 3989 " set OpenBIOS nvram variables\n", 3990 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 3991STEXI 3992@item -prom-env @var{variable}=@var{value} 3993@findex -prom-env 3994Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 3995ETEXI 3996DEF("semihosting", 0, QEMU_OPTION_semihosting, 3997 "-semihosting semihosting mode\n", 3998 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3999 QEMU_ARCH_MIPS) 4000STEXI 4001@item -semihosting 4002@findex -semihosting 4003Enable semihosting mode (ARM, M68K, Xtensa, MIPS only). 4004ETEXI 4005DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4006 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \ 4007 " semihosting configuration\n", 4008QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4009QEMU_ARCH_MIPS) 4010STEXI 4011@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]] 4012@findex -semihosting-config 4013Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only). 4014@table @option 4015@item target=@code{native|gdb|auto} 4016Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4017or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4018during debug sessions and @code{native} otherwise. 4019@item arg=@var{str1},arg=@var{str2},... 4020Allows the user to pass input arguments, and can be used multiple times to build 4021up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4022command line is still supported for backward compatibility. If both the 4023@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4024specified, the former is passed to semihosting as it always takes precedence. 4025@end table 4026ETEXI 4027DEF("old-param", 0, QEMU_OPTION_old_param, 4028 "-old-param old param mode\n", QEMU_ARCH_ARM) 4029STEXI 4030@item -old-param 4031@findex -old-param (ARM) 4032Old param mode (ARM only). 4033ETEXI 4034 4035DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4036 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4037 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4038 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4039 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4040 " by the kernel, but typically no longer used by modern\n" \ 4041 " C library implementations.\n" \ 4042 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4043 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4044 " The value 'children' will deny set*uid|gid system calls for\n" \ 4045 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4046 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4047 " blacklisting *fork and execve\n" \ 4048 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4049 QEMU_ARCH_ALL) 4050STEXI 4051@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4052@findex -sandbox 4053Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4054disable it. The default is 'off'. 4055@table @option 4056@item obsolete=@var{string} 4057Enable Obsolete system calls 4058@item elevateprivileges=@var{string} 4059Disable set*uid|gid system calls 4060@item spawn=@var{string} 4061Disable *fork and execve 4062@item resourcecontrol=@var{string} 4063Disable process affinity and schedular priority 4064@end table 4065ETEXI 4066 4067DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4068 "-readconfig <file>\n", QEMU_ARCH_ALL) 4069STEXI 4070@item -readconfig @var{file} 4071@findex -readconfig 4072Read device configuration from @var{file}. This approach is useful when you want to spawn 4073QEMU process with many command line options but you don't want to exceed the command line 4074character limit. 4075ETEXI 4076DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4077 "-writeconfig <file>\n" 4078 " read/write config file\n", QEMU_ARCH_ALL) 4079STEXI 4080@item -writeconfig @var{file} 4081@findex -writeconfig 4082Write device configuration to @var{file}. The @var{file} can be either filename to save 4083command line and device configuration into file or dash @code{-}) character to print the 4084output to stdout. This can be later used as input file for @code{-readconfig} option. 4085ETEXI 4086HXCOMM Deprecated, same as -no-user-config 4087DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL) 4088DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4089 "-no-user-config\n" 4090 " do not load default user-provided config files at startup\n", 4091 QEMU_ARCH_ALL) 4092STEXI 4093@item -no-user-config 4094@findex -no-user-config 4095The @code{-no-user-config} option makes QEMU not load any of the user-provided 4096config files on @var{sysconfdir}. 4097ETEXI 4098DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4099 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4100 " specify tracing options\n", 4101 QEMU_ARCH_ALL) 4102STEXI 4103HXCOMM This line is not accurate, as some sub-options are backend-specific but 4104HXCOMM HX does not support conditional compilation of text. 4105@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4106@findex -trace 4107@include qemu-option-trace.texi 4108ETEXI 4109 4110HXCOMM Internal use 4111DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4112DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4113 4114#ifdef __linux__ 4115DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4116 "-enable-fips enable FIPS 140-2 compliance\n", 4117 QEMU_ARCH_ALL) 4118#endif 4119STEXI 4120@item -enable-fips 4121@findex -enable-fips 4122Enable FIPS 140-2 compliance mode. 4123ETEXI 4124 4125HXCOMM Deprecated by -machine accel=tcg property 4126DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4127 4128HXCOMM Deprecated by kvm-pit driver properties 4129DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection, 4130 "", QEMU_ARCH_I386) 4131 4132HXCOMM Deprecated (ignored) 4133DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386) 4134 4135HXCOMM Deprecated by -machine kernel_irqchip=on|off property 4136DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386) 4137 4138HXCOMM Deprecated (ignored) 4139DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL) 4140 4141DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4142 "-msg timestamp[=on|off]\n" 4143 " change the format of messages\n" 4144 " on|off controls leading timestamps (default:on)\n", 4145 QEMU_ARCH_ALL) 4146STEXI 4147@item -msg timestamp[=on|off] 4148@findex -msg 4149prepend a timestamp to each log message.(default:on) 4150ETEXI 4151 4152DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4153 "-dump-vmstate <file>\n" 4154 " Output vmstate information in JSON format to file.\n" 4155 " Use the scripts/vmstate-static-checker.py file to\n" 4156 " check for possible regressions in migration code\n" 4157 " by comparing two such vmstate dumps.\n", 4158 QEMU_ARCH_ALL) 4159STEXI 4160@item -dump-vmstate @var{file} 4161@findex -dump-vmstate 4162Dump json-encoded vmstate information for current machine type to file 4163in @var{file} 4164ETEXI 4165 4166STEXI 4167@end table 4168ETEXI 4169DEFHEADING() 4170DEFHEADING(Generic object creation) 4171STEXI 4172@table @option 4173ETEXI 4174 4175DEF("object", HAS_ARG, QEMU_OPTION_object, 4176 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4177 " create a new object of type TYPENAME setting properties\n" 4178 " in the order they are specified. Note that the 'id'\n" 4179 " property must be set. These objects are placed in the\n" 4180 " '/objects' path.\n", 4181 QEMU_ARCH_ALL) 4182STEXI 4183@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4184@findex -object 4185Create a new object of type @var{typename} setting properties 4186in the order they are specified. Note that the 'id' 4187property must be set. These objects are placed in the 4188'/objects' path. 4189 4190@table @option 4191 4192@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off} 4193 4194Creates a memory file backend object, which can be used to back 4195the guest RAM with huge pages. The @option{id} parameter is a 4196unique ID that will be used to reference this memory region 4197when configuring the @option{-numa} argument. The @option{size} 4198option provides the size of the memory region, and accepts 4199common suffixes, eg @option{500M}. The @option{mem-path} provides 4200the path to either a shared memory or huge page filesystem mount. 4201The @option{share} boolean option determines whether the memory 4202region is marked as private to QEMU, or shared. The latter allows 4203a co-operating external process to access the QEMU memory region. 4204Setting the @option{discard-data} boolean option to @var{on} 4205indicates that file contents can be destroyed when QEMU exits, 4206to avoid unnecessarily flushing data to the backing file. Note 4207that @option{discard-data} is only an optimization, and QEMU 4208might not discard file contents if it aborts unexpectedly or is 4209terminated using SIGKILL. 4210 4211@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4212 4213Creates a random number generator backend which obtains entropy from 4214a device on the host. The @option{id} parameter is a unique ID that 4215will be used to reference this entropy backend from the @option{virtio-rng} 4216device. The @option{filename} parameter specifies which file to obtain 4217entropy from and if omitted defaults to @option{/dev/random}. 4218 4219@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4220 4221Creates a random number generator backend which obtains entropy from 4222an external daemon running on the host. The @option{id} parameter is 4223a unique ID that will be used to reference this entropy backend from 4224the @option{virtio-rng} device. The @option{chardev} parameter is 4225the unique ID of a character device backend that provides the connection 4226to the RNG daemon. 4227 4228@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4229 4230Creates a TLS anonymous credentials object, which can be used to provide 4231TLS support on network backends. The @option{id} parameter is a unique 4232ID which network backends will use to access the credentials. The 4233@option{endpoint} is either @option{server} or @option{client} depending 4234on whether the QEMU network backend that uses the credentials will be 4235acting as a client or as a server. If @option{verify-peer} is enabled 4236(the default) then once the handshake is completed, the peer credentials 4237will be verified, though this is a no-op for anonymous credentials. 4238 4239The @var{dir} parameter tells QEMU where to find the credential 4240files. For server endpoints, this directory may contain a file 4241@var{dh-params.pem} providing diffie-hellman parameters to use 4242for the TLS server. If the file is missing, QEMU will generate 4243a set of DH parameters at startup. This is a computationally 4244expensive operation that consumes random pool entropy, so it is 4245recommended that a persistent set of parameters be generated 4246upfront and saved. 4247 4248@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} 4249 4250Creates a TLS anonymous credentials object, which can be used to provide 4251TLS support on network backends. The @option{id} parameter is a unique 4252ID which network backends will use to access the credentials. The 4253@option{endpoint} is either @option{server} or @option{client} depending 4254on whether the QEMU network backend that uses the credentials will be 4255acting as a client or as a server. If @option{verify-peer} is enabled 4256(the default) then once the handshake is completed, the peer credentials 4257will be verified. With x509 certificates, this implies that the clients 4258must be provided with valid client certificates too. 4259 4260The @var{dir} parameter tells QEMU where to find the credential 4261files. For server endpoints, this directory may contain a file 4262@var{dh-params.pem} providing diffie-hellman parameters to use 4263for the TLS server. If the file is missing, QEMU will generate 4264a set of DH parameters at startup. This is a computationally 4265expensive operation that consumes random pool entropy, so it is 4266recommended that a persistent set of parameters be generated 4267upfront and saved. 4268 4269For x509 certificate credentials the directory will contain further files 4270providing the x509 certificates. The certificates must be stored 4271in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4272@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4273@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4274 4275For the @var{server-key.pem} and @var{client-key.pem} files which 4276contain sensitive private keys, it is possible to use an encrypted 4277version by providing the @var{passwordid} parameter. This provides 4278the ID of a previously created @code{secret} object containing the 4279password for decryption. 4280 4281@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4282 4283Interval @var{t} can't be 0, this filter batches the packet delivery: all 4284packets arriving in a given interval on netdev @var{netdevid} are delayed 4285until the end of the interval. Interval is in microseconds. 4286@option{status} is optional that indicate whether the netfilter is 4287on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4288 4289queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4290 4291@option{all}: the filter is attached both to the receive and the transmit 4292 queue of the netdev (default). 4293 4294@option{rx}: the filter is attached to the receive queue of the netdev, 4295 where it will receive packets sent to the netdev. 4296 4297@option{tx}: the filter is attached to the transmit queue of the netdev, 4298 where it will receive packets sent by the netdev. 4299 4300@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4301 4302filter-mirror on netdev @var{netdevid},mirror net packet to chardev@var{chardevid}, if it has the vnet_hdr_support flag, filter-mirror will mirror packet with vnet_hdr_len. 4303 4304@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4305 4306filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4307@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4308filter-redirector will redirect packet with vnet_hdr_len. 4309Create a filter-redirector we need to differ outdev id from indev id, id can not 4310be the same. we can just use indev or outdev, but at least one of indev or outdev 4311need to be specified. 4312 4313@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4314 4315Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4316secondary from primary to keep secondary tcp connection,and rewrite 4317tcp packet to primary from secondary make tcp packet can be handled by 4318client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4319 4320usage: 4321colo secondary: 4322-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4323-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4324-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4325 4326@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4327 4328Dump the network traffic on netdev @var{dev} to the file specified by 4329@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4330The file format is libpcap, so it can be analyzed with tools such as tcpdump 4331or Wireshark. 4332 4333@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support] 4334 4335Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4336secondary packet. If the packets are same, we will output primary 4337packet to outdev@var{chardevid}, else we will notify colo-frame 4338do checkpoint and send primary packet to outdev@var{chardevid}. 4339if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len. 4340 4341we must use it with the help of filter-mirror and filter-redirector. 4342 4343@example 4344 4345primary: 4346-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4347-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4348-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4349-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4350-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4351-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4352-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4353-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4354-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4355-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4356-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4357-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0 4358 4359secondary: 4360-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4361-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4362-chardev socket,id=red0,host=3.3.3.3,port=9003 4363-chardev socket,id=red1,host=3.3.3.3,port=9004 4364-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4365-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4366 4367@end example 4368 4369If you want to know the detail of above command line, you can read 4370the colo-compare git log. 4371 4372@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4373 4374Creates a cryptodev backend which executes crypto opreation from 4375the QEMU cipher APIS. The @var{id} parameter is 4376a unique ID that will be used to reference this cryptodev backend from 4377the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4378which specify the queue number of cryptodev backend, the default of 4379@var{queues} is 1. 4380 4381@example 4382 4383 # qemu-system-x86_64 \ 4384 [...] \ 4385 -object cryptodev-backend-builtin,id=cryptodev0 \ 4386 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4387 [...] 4388@end example 4389 4390@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4391@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4392 4393Defines a secret to store a password, encryption key, or some other sensitive 4394data. The sensitive data can either be passed directly via the @var{data} 4395parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4396parameter is insecure unless the sensitive data is encrypted. 4397 4398The sensitive data can be provided in raw format (the default), or base64. 4399When encoded as JSON, the raw format only supports valid UTF-8 characters, 4400so base64 is recommended for sending binary data. QEMU will convert from 4401which ever format is provided to the format it needs internally. eg, an 4402RBD password can be provided in raw format, even though it will be base64 4403encoded when passed onto the RBD sever. 4404 4405For added protection, it is possible to encrypt the data associated with 4406a secret using the AES-256-CBC cipher. Use of encryption is indicated 4407by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4408parameter provides the ID of a previously defined secret that contains 4409the AES-256 decryption key. This key should be 32-bytes long and be 4410base64 encoded. The @var{iv} parameter provides the random initialization 4411vector used for encryption of this particular secret and should be a 4412base64 encrypted string of the 16-byte IV. 4413 4414The simplest (insecure) usage is to provide the secret inline 4415 4416@example 4417 4418 # $QEMU -object secret,id=sec0,data=letmein,format=raw 4419 4420@end example 4421 4422The simplest secure usage is to provide the secret via a file 4423 4424 # printf "letmein" > mypasswd.txt 4425 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw 4426 4427For greater security, AES-256-CBC should be used. To illustrate usage, 4428consider the openssl command line tool which can encrypt the data. Note 4429that when encrypting, the plaintext must be padded to the cipher block 4430size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4431 4432First a master key needs to be created in base64 encoding: 4433 4434@example 4435 # openssl rand -base64 32 > key.b64 4436 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4437@end example 4438 4439Each secret to be encrypted needs to have a random initialization vector 4440generated. These do not need to be kept secret 4441 4442@example 4443 # openssl rand -base64 16 > iv.b64 4444 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4445@end example 4446 4447The secret to be defined can now be encrypted, in this case we're 4448telling openssl to base64 encode the result, but it could be left 4449as raw bytes if desired. 4450 4451@example 4452 # SECRET=$(printf "letmein" | 4453 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4454@end example 4455 4456When launching QEMU, create a master secret pointing to @code{key.b64} 4457and specify that to be used to decrypt the user password. Pass the 4458contents of @code{iv.b64} to the second secret 4459 4460@example 4461 # $QEMU \ 4462 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4463 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4464 data=$SECRET,iv=$(<iv.b64) 4465@end example 4466 4467@end table 4468 4469ETEXI 4470 4471 4472HXCOMM This is the last statement. Insert new options before this line! 4473STEXI 4474@end table 4475ETEXI 4476
