1HXCOMM Use DEFHEADING() to define headings in both help text and rST. 2HXCOMM Text between SRST and ERST is copied to the rST 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 rST and C. 8 9DEFHEADING(Standard options:) 10 11DEF("help", 0, QEMU_OPTION_h, 12 "-h or -help display this help and exit\n", QEMU_ARCH_ALL) 13SRST 14``-h`` 15 Display help and exit 16ERST 17 18DEF("version", 0, QEMU_OPTION_version, 19 "-version display version information and exit\n", QEMU_ARCH_ALL) 20SRST 21``-version`` 22 Display version information and exit 23ERST 24 25DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ 26 "-machine [type=]name[,prop[=value][,...]]\n" 27 " selects emulated machine ('-machine help' for list)\n" 28 " property accel=accel1[:accel2[:...]] selects accelerator\n" 29 " supported accelerators are kvm, xen, hax, hvf, whpx or tcg (default: tcg)\n" 30 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 31 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 32 " mem-merge=on|off controls memory merge support (default: on)\n" 33 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 34 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 35 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 36 " nvdimm=on|off controls NVDIMM support (default=off)\n" 37 " enforce-config-section=on|off enforce configuration section migration (default=off)\n" 38 " memory-encryption=@var{} memory encryption object to use (default=none)\n" 39 " hmat=on|off controls ACPI HMAT support (default=off)\n", 40 QEMU_ARCH_ALL) 41SRST 42``-machine [type=]name[,prop=value[,...]]`` 43 Select the emulated machine by name. Use ``-machine help`` to list 44 available machines. 45 46 For architectures which aim to support live migration compatibility 47 across releases, each release will introduce a new versioned machine 48 type. For example, the 2.8.0 release introduced machine types 49 "pc-i440fx-2.8" and "pc-q35-2.8" for the x86\_64/i686 architectures. 50 51 To allow live migration of guests from QEMU version 2.8.0, to QEMU 52 version 2.9.0, the 2.9.0 version must support the "pc-i440fx-2.8" 53 and "pc-q35-2.8" machines too. To allow users live migrating VMs to 54 skip multiple intermediate releases when upgrading, new releases of 55 QEMU will support machine types from many previous versions. 56 57 Supported machine properties are: 58 59 ``accel=accels1[:accels2[:...]]`` 60 This is used to enable an accelerator. Depending on the target 61 architecture, kvm, xen, hax, hvf, whpx or tcg can be available. 62 By default, tcg is used. If there is more than one accelerator 63 specified, the next one is used if the previous one fails to 64 initialize. 65 66 ``vmport=on|off|auto`` 67 Enables emulation of VMWare IO port, for vmmouse etc. auto says 68 to select the value based on accel. For accel=xen the default is 69 off otherwise the default is on. 70 71 ``dump-guest-core=on|off`` 72 Include guest memory in a core dump. The default is on. 73 74 ``mem-merge=on|off`` 75 Enables or disables memory merge support. This feature, when 76 supported by the host, de-duplicates identical memory pages 77 among VMs instances (enabled by default). 78 79 ``aes-key-wrap=on|off`` 80 Enables or disables AES key wrapping support on s390-ccw hosts. 81 This feature controls whether AES wrapping keys will be created 82 to allow execution of AES cryptographic functions. The default 83 is on. 84 85 ``dea-key-wrap=on|off`` 86 Enables or disables DEA key wrapping support on s390-ccw hosts. 87 This feature controls whether DEA wrapping keys will be created 88 to allow execution of DEA cryptographic functions. The default 89 is on. 90 91 ``nvdimm=on|off`` 92 Enables or disables NVDIMM support. The default is off. 93 94 ``enforce-config-section=on|off`` 95 If ``enforce-config-section`` is set to on, force migration code 96 to send configuration section even if the machine-type sets the 97 ``migration.send-configuration`` property to off. NOTE: this 98 parameter is deprecated. Please use ``-global`` 99 ``migration.send-configuration``\ =on\|off instead. 100 101 ``memory-encryption=`` 102 Memory encryption object to use. The default is none. 103 104 ``hmat=on|off`` 105 Enables or disables ACPI Heterogeneous Memory Attribute Table 106 (HMAT) support. The default is off. 107ERST 108 109HXCOMM Deprecated by -machine 110DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 111 112DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 113 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 114SRST 115``-cpu model`` 116 Select CPU model (``-cpu help`` for list and additional feature 117 selection) 118ERST 119 120DEF("accel", HAS_ARG, QEMU_OPTION_accel, 121 "-accel [accel=]accelerator[,prop[=value][,...]]\n" 122 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n" 123 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n" 124 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n" 125 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n" 126 " tb-size=n (TCG translation block cache size)\n" 127 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 128SRST 129``-accel name[,prop=value[,...]]`` 130 This is used to enable an accelerator. Depending on the target 131 architecture, kvm, xen, hax, hvf, whpx or tcg can be available. By 132 default, tcg is used. If there is more than one accelerator 133 specified, the next one is used if the previous one fails to 134 initialize. 135 136 ``igd-passthru=on|off`` 137 When Xen is in use, this option controls whether Intel 138 integrated graphics devices can be passed through to the guest 139 (default=off) 140 141 ``kernel-irqchip=on|off|split`` 142 Controls KVM in-kernel irqchip support. The default is full 143 acceleration of the interrupt controllers. On x86, split irqchip 144 reduces the kernel attack surface, at a performance cost for 145 non-MSI interrupts. Disabling the in-kernel irqchip completely 146 is not recommended except for debugging purposes. 147 148 ``kvm-shadow-mem=size`` 149 Defines the size of the KVM shadow MMU. 150 151 ``tb-size=n`` 152 Controls the size (in MiB) of the TCG translation block cache. 153 154 ``thread=single|multi`` 155 Controls number of TCG threads. When the TCG is multi-threaded 156 there will be one thread per vCPU therefor taking advantage of 157 additional host cores. The default is to enable multi-threading 158 where both the back-end and front-ends support it and no 159 incompatible TCG features have been enabled (e.g. 160 icount/replay). 161ERST 162 163DEF("smp", HAS_ARG, QEMU_OPTION_smp, 164 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n" 165 " set the number of CPUs to 'n' [default=1]\n" 166 " maxcpus= maximum number of total cpus, including\n" 167 " offline CPUs for hotplug, etc\n" 168 " cores= number of CPU cores on one socket (for PC, it's on one die)\n" 169 " threads= number of threads on one CPU core\n" 170 " dies= number of CPU dies on one socket (for PC only)\n" 171 " sockets= number of discrete sockets in the system\n", 172 QEMU_ARCH_ALL) 173SRST 174``-smp [cpus=]n[,cores=cores][,threads=threads][,dies=dies][,sockets=sockets][,maxcpus=maxcpus]`` 175 Simulate an SMP system with n CPUs. On the PC target, up to 255 CPUs 176 are supported. On Sparc32 target, Linux limits the number of usable 177 CPUs to 4. For the PC target, the number of cores per die, the 178 number of threads per cores, the number of dies per packages and the 179 total number of sockets can be specified. Missing values will be 180 computed. If any on the three values is given, the total number of 181 CPUs n can be omitted. maxcpus specifies the maximum number of 182 hotpluggable CPUs. 183ERST 184 185DEF("numa", HAS_ARG, QEMU_OPTION_numa, 186 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 187 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 188 "-numa dist,src=source,dst=destination,val=distance\n" 189 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n" 190 "-numa hmat-lb,initiator=node,target=node,hierarchy=memory|first-level|second-level|third-level,data-type=access-latency|read-latency|write-latency[,latency=lat][,bandwidth=bw]\n" 191 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n", 192 QEMU_ARCH_ALL) 193SRST 194``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 195 \ 196``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 197 \ 198``-numa dist,src=source,dst=destination,val=distance`` 199 \ 200``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]`` 201 \ 202``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=tpye[,latency=lat][,bandwidth=bw]`` 203 \ 204``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]`` 205 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA 206 distance from a source node to a destination node. Set the ACPI 207 Heterogeneous Memory Attributes for the given nodes. 208 209 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and 210 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a 211 contiguous range of CPU indexes (or a single VCPU if lastcpu is 212 omitted). A non-contiguous set of VCPUs can be represented by 213 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is 214 omitted on all nodes, VCPUs are automatically split between them. 215 216 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a 217 NUMA node: 218 219 :: 220 221 -numa node,cpus=0-2,cpus=5 222 223 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option 224 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to 225 assign CPU objects to a node using topology layout properties of 226 CPU. The set of properties is machine specific, and depends on used 227 machine type/'\ ``smp``\ ' options. It could be queried with 228 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ ' 229 property specifies node to which CPU object will be assigned, it's 230 required for node to be declared with '\ ``node``\ ' option before 231 it's used with '\ ``cpu``\ ' option. 232 233 For example: 234 235 :: 236 237 -M pc \ 238 -smp 1,sockets=2,maxcpus=2 \ 239 -numa node,nodeid=0 -numa node,nodeid=1 \ 240 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 241 242 Legacy '\ ``mem``\ ' assigns a given RAM amount to a node (not supported 243 for 5.1 and newer machine types). '\ ``memdev``\ ' assigns RAM from 244 a given memory backend device to a node. If '\ ``mem``\ ' and 245 '\ ``memdev``\ ' are omitted in all nodes, RAM is split equally between them. 246 247 248 '\ ``mem``\ ' and '\ ``memdev``\ ' are mutually exclusive. 249 Furthermore, if one node uses '\ ``memdev``\ ', all of them have to 250 use it. 251 252 '\ ``initiator``\ ' is an additional option that points to an 253 initiator NUMA node that has best performance (the lowest latency or 254 largest bandwidth) to this NUMA node. Note that this option can be 255 set only when the machine property 'hmat' is set to 'on'. 256 257 Following example creates a machine with 2 NUMA nodes, node 0 has 258 CPU. node 1 has only memory, and its initiator is node 0. Note that 259 because node 0 has CPU, by default the initiator of node 0 is itself 260 and must be itself. 261 262 :: 263 264 -machine hmat=on \ 265 -m 2G,slots=2,maxmem=4G \ 266 -object memory-backend-ram,size=1G,id=m0 \ 267 -object memory-backend-ram,size=1G,id=m1 \ 268 -numa node,nodeid=0,memdev=m0 \ 269 -numa node,nodeid=1,memdev=m1,initiator=0 \ 270 -smp 2,sockets=2,maxcpus=2 \ 271 -numa cpu,node-id=0,socket-id=0 \ 272 -numa cpu,node-id=0,socket-id=1 273 274 source and destination are NUMA node IDs. distance is the NUMA 275 distance from source to destination. The distance from a node to 276 itself is always 10. If any pair of nodes is given a distance, then 277 all pairs must be given distances. Although, when distances are only 278 given in one direction for each pair of nodes, then the distances in 279 the opposite directions are assumed to be the same. If, however, an 280 asymmetrical pair of distances is given for even one node pair, then 281 all node pairs must be provided distance values for both directions, 282 even when they are symmetrical. When a node is unreachable from 283 another node, set the pair's distance to 255. 284 285 Note that the -``numa`` option doesn't allocate any of the specified 286 resources, it just assigns existing resources to NUMA nodes. This 287 means that one still has to use the ``-m``, ``-smp`` options to 288 allocate RAM and VCPUs respectively. 289 290 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth 291 Information between initiator and target NUMA nodes in ACPI 292 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can 293 create memory requests, usually it has one or more processors. 294 Target NUMA node contains addressable memory. 295 296 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is 297 the memory hierarchy of the target NUMA node: if hierarchy is 298 'memory', the structure represents the memory performance; if 299 hierarchy is 'first-level\|second-level\|third-level', this 300 structure represents aggregated performance of memory side caches 301 for each domain. type of 'data-type' is type of data represented by 302 this structure instance: if 'hierarchy' is 'memory', 'data-type' is 303 'access\|read\|write' latency or 'access\|read\|write' bandwidth of 304 the target memory; if 'hierarchy' is 305 'first-level\|second-level\|third-level', 'data-type' is 306 'access\|read\|write' hit latency or 'access\|read\|write' hit 307 bandwidth of the target memory side cache. 308 309 lat is latency value in nanoseconds. bw is bandwidth value, the 310 possible value and units are NUM[M\|G\|T], mean that the bandwidth 311 value are NUM byte per second (or MB/s, GB/s or TB/s depending on 312 used suffix). Note that if latency or bandwidth value is 0, means 313 the corresponding latency or bandwidth information is not provided. 314 315 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory 316 belongs. size is the size of memory side cache in bytes. level is 317 the cache level described in this structure, note that the cache 318 level 0 should not be used with '\ ``hmat-cache``\ ' option. 319 associativity is the cache associativity, the possible value is 320 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy 321 is the write policy. line is the cache Line size in bytes. 322 323 For example, the following options describe 2 NUMA nodes. Node 0 has 324 2 cpus and a ram, node 1 has only a ram. The processors in node 0 325 access memory in node 0 with access-latency 5 nanoseconds, 326 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access 327 memory in NUMA node 1 with access-latency 10 nanoseconds, 328 access-bandwidth is 100 MB/s. And for memory side cache information, 329 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB, 330 policy is write-back, the cache Line size is 8 bytes: 331 332 :: 333 334 -machine hmat=on \ 335 -m 2G \ 336 -object memory-backend-ram,size=1G,id=m0 \ 337 -object memory-backend-ram,size=1G,id=m1 \ 338 -smp 2 \ 339 -numa node,nodeid=0,memdev=m0 \ 340 -numa node,nodeid=1,memdev=m1,initiator=0 \ 341 -numa cpu,node-id=0,socket-id=0 \ 342 -numa cpu,node-id=0,socket-id=1 \ 343 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \ 344 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \ 345 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \ 346 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \ 347 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \ 348 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8 349ERST 350 351DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 352 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 353 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 354SRST 355``-add-fd fd=fd,set=set[,opaque=opaque]`` 356 Add a file descriptor to an fd set. Valid options are: 357 358 ``fd=fd`` 359 This option defines the file descriptor of which a duplicate is 360 added to fd set. The file descriptor cannot be stdin, stdout, or 361 stderr. 362 363 ``set=set`` 364 This option defines the ID of the fd set to add the file 365 descriptor to. 366 367 ``opaque=opaque`` 368 This option defines a free-form string that can be used to 369 describe fd. 370 371 You can open an image using pre-opened file descriptors from an fd 372 set: 373 374 .. parsed-literal:: 375 376 |qemu_system| \\ 377 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 378 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 379 -drive file=/dev/fdset/2,index=0,media=disk 380ERST 381 382DEF("set", HAS_ARG, QEMU_OPTION_set, 383 "-set group.id.arg=value\n" 384 " set <arg> parameter for item <id> of type <group>\n" 385 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 386SRST 387``-set group.id.arg=value`` 388 Set parameter arg for item id of type group 389ERST 390 391DEF("global", HAS_ARG, QEMU_OPTION_global, 392 "-global driver.property=value\n" 393 "-global driver=driver,property=property,value=value\n" 394 " set a global default for a driver property\n", 395 QEMU_ARCH_ALL) 396SRST 397``-global driver.prop=value`` 398 \ 399``-global driver=driver,property=property,value=value`` 400 Set default value of driver's property prop to value, e.g.: 401 402 .. parsed-literal:: 403 404 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img 405 406 In particular, you can use this to set driver properties for devices 407 which are created automatically by the machine model. To create a 408 device which is not created automatically and set properties on it, 409 use -``device``. 410 411 -global driver.prop=value is shorthand for -global 412 driver=driver,property=prop,value=value. The longhand syntax works 413 even when driver contains a dot. 414ERST 415 416DEF("boot", HAS_ARG, QEMU_OPTION_boot, 417 "-boot [order=drives][,once=drives][,menu=on|off]\n" 418 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 419 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 420 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 421 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 422 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 423 QEMU_ARCH_ALL) 424SRST 425``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]`` 426 Specify boot order drives as a string of drive letters. Valid drive 427 letters depend on the target architecture. The x86 PC uses: a, b 428 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p 429 (Etherboot from network adapter 1-4), hard disk boot is the default. 430 To apply a particular boot order only on the first startup, specify 431 it via ``once``. Note that the ``order`` or ``once`` parameter 432 should not be used together with the ``bootindex`` property of 433 devices, since the firmware implementations normally do not support 434 both at the same time. 435 436 Interactive boot menus/prompts can be enabled via ``menu=on`` as far 437 as firmware/BIOS supports them. The default is non-interactive boot. 438 439 A splash picture could be passed to bios, enabling user to show it 440 as logo, when option splash=sp\_name is given and menu=on, If 441 firmware/BIOS supports them. Currently Seabios for X86 system 442 support it. limitation: The splash file could be a jpeg file or a 443 BMP file in 24 BPP format(true color). The resolution should be 444 supported by the SVGA mode, so the recommended is 320x240, 640x480, 445 800x640. 446 447 A timeout could be passed to bios, guest will pause for rb\_timeout 448 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will 449 not reboot, qemu passes '-1' to bios by default. Currently Seabios 450 for X86 system support it. 451 452 Do strict boot via ``strict=on`` as far as firmware/BIOS supports 453 it. This only effects when boot priority is changed by bootindex 454 options. The default is non-strict boot. 455 456 .. parsed-literal:: 457 458 # try to boot from network first, then from hard disk 459 |qemu_system_x86| -boot order=nc 460 # boot from CD-ROM first, switch back to default order after reboot 461 |qemu_system_x86| -boot once=d 462 # boot with a splash picture for 5 seconds. 463 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000 464 465 Note: The legacy format '-boot drives' is still supported but its 466 use is discouraged as it may be removed from future versions. 467ERST 468 469DEF("m", HAS_ARG, QEMU_OPTION_m, 470 "-m [size=]megs[,slots=n,maxmem=size]\n" 471 " configure guest RAM\n" 472 " size: initial amount of guest memory\n" 473 " slots: number of hotplug slots (default: none)\n" 474 " maxmem: maximum amount of guest memory (default: none)\n" 475 "NOTE: Some architectures might enforce a specific granularity\n", 476 QEMU_ARCH_ALL) 477SRST 478``-m [size=]megs[,slots=n,maxmem=size]`` 479 Sets guest startup RAM size to megs megabytes. Default is 128 MiB. 480 Optionally, a suffix of "M" or "G" can be used to signify a value in 481 megabytes or gigabytes respectively. Optional pair slots, maxmem 482 could be used to set amount of hotpluggable memory slots and maximum 483 amount of memory. Note that maxmem must be aligned to the page size. 484 485 For example, the following command-line sets the guest startup RAM 486 size to 1GB, creates 3 slots to hotplug additional memory and sets 487 the maximum memory the guest can reach to 4GB: 488 489 .. parsed-literal:: 490 491 |qemu_system| -m 1G,slots=3,maxmem=4G 492 493 If slots and maxmem are not specified, memory hotplug won't be 494 enabled and the guest startup RAM will never increase. 495ERST 496 497DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 498 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 499SRST 500``-mem-path path`` 501 Allocate guest RAM from a temporarily created file in path. 502ERST 503 504DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 505 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 506 QEMU_ARCH_ALL) 507SRST 508``-mem-prealloc`` 509 Preallocate memory when using -mem-path. 510ERST 511 512DEF("k", HAS_ARG, QEMU_OPTION_k, 513 "-k language use keyboard layout (for example 'fr' for French)\n", 514 QEMU_ARCH_ALL) 515SRST 516``-k language`` 517 Use keyboard layout language (for example ``fr`` for French). This 518 option is only needed where it is not easy to get raw PC keycodes 519 (e.g. on Macs, with some X11 servers or with a VNC or curses 520 display). You don't normally need to use it on PC/Linux or 521 PC/Windows hosts. 522 523 The available layouts are: 524 525 :: 526 527 ar de-ch es fo fr-ca hu ja mk no pt-br sv 528 da en-gb et fr fr-ch is lt nl pl ru th 529 de en-us fi fr-be hr it lv nl-be pt sl tr 530 531 The default is ``en-us``. 532ERST 533 534 535HXCOMM Deprecated by -audiodev 536DEF("audio-help", 0, QEMU_OPTION_audio_help, 537 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 538 QEMU_ARCH_ALL) 539SRST 540``-audio-help`` 541 Will show the -audiodev equivalent of the currently specified 542 (deprecated) environment variables. 543ERST 544 545DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 546 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 547 " specifies the audio backend to use\n" 548 " id= identifier of the backend\n" 549 " timer-period= timer period in microseconds\n" 550 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 551 " in|out.fixed-settings= use fixed settings for host audio\n" 552 " in|out.frequency= frequency to use with fixed settings\n" 553 " in|out.channels= number of channels to use with fixed settings\n" 554 " in|out.format= sample format to use with fixed settings\n" 555 " valid values: s8, s16, s32, u8, u16, u32, f32\n" 556 " in|out.voices= number of voices to use\n" 557 " in|out.buffer-length= length of buffer in microseconds\n" 558 "-audiodev none,id=id,[,prop[=value][,...]]\n" 559 " dummy driver that discards all output\n" 560#ifdef CONFIG_AUDIO_ALSA 561 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 562 " in|out.dev= name of the audio device to use\n" 563 " in|out.period-length= length of period in microseconds\n" 564 " in|out.try-poll= attempt to use poll mode\n" 565 " threshold= threshold (in microseconds) when playback starts\n" 566#endif 567#ifdef CONFIG_AUDIO_COREAUDIO 568 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 569 " in|out.buffer-count= number of buffers\n" 570#endif 571#ifdef CONFIG_AUDIO_DSOUND 572 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 573 " latency= add extra latency to playback in microseconds\n" 574#endif 575#ifdef CONFIG_AUDIO_OSS 576 "-audiodev oss,id=id[,prop[=value][,...]]\n" 577 " in|out.dev= path of the audio device to use\n" 578 " in|out.buffer-count= number of buffers\n" 579 " in|out.try-poll= attempt to use poll mode\n" 580 " try-mmap= try using memory mapped access\n" 581 " exclusive= open device in exclusive mode\n" 582 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 583#endif 584#ifdef CONFIG_AUDIO_PA 585 "-audiodev pa,id=id[,prop[=value][,...]]\n" 586 " server= PulseAudio server address\n" 587 " in|out.name= source/sink device name\n" 588 " in|out.latency= desired latency in microseconds\n" 589#endif 590#ifdef CONFIG_AUDIO_SDL 591 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 592#endif 593#ifdef CONFIG_SPICE 594 "-audiodev spice,id=id[,prop[=value][,...]]\n" 595#endif 596 "-audiodev wav,id=id[,prop[=value][,...]]\n" 597 " path= path of wav file to record\n", 598 QEMU_ARCH_ALL) 599SRST 600``-audiodev [driver=]driver,id=id[,prop[=value][,...]]`` 601 Adds a new audio backend driver identified by id. There are global 602 and driver specific properties. Some values can be set differently 603 for input and output, they're marked with ``in|out.``. You can set 604 the input's property with ``in.prop`` and the output's property with 605 ``out.prop``. For example: 606 607 :: 608 609 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 610 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 611 612 NOTE: parameter validation is known to be incomplete, in many cases 613 specifying an invalid option causes QEMU to print an error message 614 and continue emulation without sound. 615 616 Valid global options are: 617 618 ``id=identifier`` 619 Identifies the audio backend. 620 621 ``timer-period=period`` 622 Sets the timer period used by the audio subsystem in 623 microseconds. Default is 10000 (10 ms). 624 625 ``in|out.mixing-engine=on|off`` 626 Use QEMU's mixing engine to mix all streams inside QEMU and 627 convert audio formats when not supported by the backend. When 628 off, fixed-settings must be off too. Note that disabling this 629 option means that the selected backend must support multiple 630 streams and the audio formats used by the virtual cards, 631 otherwise you'll get no sound. It's not recommended to disable 632 this option unless you want to use 5.1 or 7.1 audio, as mixing 633 engine only supports mono and stereo audio. Default is on. 634 635 ``in|out.fixed-settings=on|off`` 636 Use fixed settings for host audio. When off, it will change 637 based on how the guest opens the sound card. In this case you 638 must not specify frequency, channels or format. Default is on. 639 640 ``in|out.frequency=frequency`` 641 Specify the frequency to use when using fixed-settings. Default 642 is 44100Hz. 643 644 ``in|out.channels=channels`` 645 Specify the number of channels to use when using fixed-settings. 646 Default is 2 (stereo). 647 648 ``in|out.format=format`` 649 Specify the sample format to use when using fixed-settings. 650 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``, 651 ``u32``, ``f32``. Default is ``s16``. 652 653 ``in|out.voices=voices`` 654 Specify the number of voices to use. Default is 1. 655 656 ``in|out.buffer-length=usecs`` 657 Sets the size of the buffer in microseconds. 658 659``-audiodev none,id=id[,prop[=value][,...]]`` 660 Creates a dummy backend that discards all outputs. This backend has 661 no backend specific properties. 662 663``-audiodev alsa,id=id[,prop[=value][,...]]`` 664 Creates backend using the ALSA. This backend is only available on 665 Linux. 666 667 ALSA specific options are: 668 669 ``in|out.dev=device`` 670 Specify the ALSA device to use for input and/or output. Default 671 is ``default``. 672 673 ``in|out.period-length=usecs`` 674 Sets the period length in microseconds. 675 676 ``in|out.try-poll=on|off`` 677 Attempt to use poll mode with the device. Default is on. 678 679 ``threshold=threshold`` 680 Threshold (in microseconds) when playback starts. Default is 0. 681 682``-audiodev coreaudio,id=id[,prop[=value][,...]]`` 683 Creates a backend using Apple's Core Audio. This backend is only 684 available on Mac OS and only supports playback. 685 686 Core Audio specific options are: 687 688 ``in|out.buffer-count=count`` 689 Sets the count of the buffers. 690 691``-audiodev dsound,id=id[,prop[=value][,...]]`` 692 Creates a backend using Microsoft's DirectSound. This backend is 693 only available on Windows and only supports playback. 694 695 DirectSound specific options are: 696 697 ``latency=usecs`` 698 Add extra usecs microseconds latency to playback. Default is 699 10000 (10 ms). 700 701``-audiodev oss,id=id[,prop[=value][,...]]`` 702 Creates a backend using OSS. This backend is available on most 703 Unix-like systems. 704 705 OSS specific options are: 706 707 ``in|out.dev=device`` 708 Specify the file name of the OSS device to use. Default is 709 ``/dev/dsp``. 710 711 ``in|out.buffer-count=count`` 712 Sets the count of the buffers. 713 714 ``in|out.try-poll=on|of`` 715 Attempt to use poll mode with the device. Default is on. 716 717 ``try-mmap=on|off`` 718 Try using memory mapped device access. Default is off. 719 720 ``exclusive=on|off`` 721 Open the device in exclusive mode (vmix won't work in this 722 case). Default is off. 723 724 ``dsp-policy=policy`` 725 Sets the timing policy (between 0 and 10, where smaller number 726 means smaller latency but higher CPU usage). Use -1 to use 727 buffer sizes specified by ``buffer`` and ``buffer-count``. This 728 option is ignored if you do not have OSS 4. Default is 5. 729 730``-audiodev pa,id=id[,prop[=value][,...]]`` 731 Creates a backend using PulseAudio. This backend is available on 732 most systems. 733 734 PulseAudio specific options are: 735 736 ``server=server`` 737 Sets the PulseAudio server to connect to. 738 739 ``in|out.name=sink`` 740 Use the specified source/sink for recording/playback. 741 742 ``in|out.latency=usecs`` 743 Desired latency in microseconds. The PulseAudio server will try 744 to honor this value but actual latencies may be lower or higher. 745 746``-audiodev sdl,id=id[,prop[=value][,...]]`` 747 Creates a backend using SDL. This backend is available on most 748 systems, but you should use your platform's native backend if 749 possible. This backend has no backend specific properties. 750 751``-audiodev spice,id=id[,prop[=value][,...]]`` 752 Creates a backend that sends audio through SPICE. This backend 753 requires ``-spice`` and automatically selected in that case, so 754 usually you can ignore this option. This backend has no backend 755 specific properties. 756 757``-audiodev wav,id=id[,prop[=value][,...]]`` 758 Creates a backend that writes audio to a WAV file. 759 760 Backend specific options are: 761 762 ``path=path`` 763 Write recorded audio into the specified file. Default is 764 ``qemu.wav``. 765ERST 766 767DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 768 "-soundhw c1,... enable audio support\n" 769 " and only specified sound cards (comma separated list)\n" 770 " use '-soundhw help' to get the list of supported cards\n" 771 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 772SRST 773``-soundhw card1[,card2,...] or -soundhw all`` 774 Enable audio and selected sound hardware. Use 'help' to print all 775 available sound hardware. For example: 776 777 .. parsed-literal:: 778 779 |qemu_system_x86| -soundhw sb16,adlib disk.img 780 |qemu_system_x86| -soundhw es1370 disk.img 781 |qemu_system_x86| -soundhw ac97 disk.img 782 |qemu_system_x86| -soundhw hda disk.img 783 |qemu_system_x86| -soundhw all disk.img 784 |qemu_system_x86| -soundhw help 785 786 Note that Linux's i810\_audio OSS kernel (for AC97) module might 787 require manually specifying clocking. 788 789 :: 790 791 modprobe i810_audio clocking=48000 792ERST 793 794DEF("device", HAS_ARG, QEMU_OPTION_device, 795 "-device driver[,prop[=value][,...]]\n" 796 " add device (based on driver)\n" 797 " prop=value,... sets driver properties\n" 798 " use '-device help' to print all possible drivers\n" 799 " use '-device driver,help' to print all possible properties\n", 800 QEMU_ARCH_ALL) 801SRST 802``-device driver[,prop[=value][,...]]`` 803 Add device driver. prop=value sets driver properties. Valid 804 properties depend on the driver. To get help on possible drivers and 805 properties, use ``-device help`` and ``-device driver,help``. 806 807 Some drivers are: 808 809``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]`` 810 Add an IPMI BMC. This is a simulation of a hardware management 811 interface processor that normally sits on a system. It provides a 812 watchdog and the ability to reset and power control the system. You 813 need to connect this to an IPMI interface to make it useful 814 815 The IPMI slave address to use for the BMC. The default is 0x20. This 816 address is the BMC's address on the I2C network of management 817 controllers. If you don't know what this means, it is safe to ignore 818 it. 819 820 ``id=id`` 821 The BMC id for interfaces to use this device. 822 823 ``slave_addr=val`` 824 Define slave address to use for the BMC. The default is 0x20. 825 826 ``sdrfile=file`` 827 file containing raw Sensor Data Records (SDR) data. The default 828 is none. 829 830 ``fruareasize=val`` 831 size of a Field Replaceable Unit (FRU) area. The default is 832 1024. 833 834 ``frudatafile=file`` 835 file containing raw Field Replaceable Unit (FRU) inventory data. 836 The default is none. 837 838 ``guid=uuid`` 839 value for the GUID for the BMC, in standard UUID format. If this 840 is set, get "Get GUID" command to the BMC will return it. 841 Otherwise "Get GUID" will return an error. 842 843``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]`` 844 Add a connection to an external IPMI BMC simulator. Instead of 845 locally emulating the BMC like the above item, instead connect to an 846 external entity that provides the IPMI services. 847 848 A connection is made to an external BMC simulator. If you do this, 849 it is strongly recommended that you use the "reconnect=" chardev 850 option to reconnect to the simulator if the connection is lost. Note 851 that if this is not used carefully, it can be a security issue, as 852 the interface has the ability to send resets, NMIs, and power off 853 the VM. It's best if QEMU makes a connection to an external 854 simulator running on a secure port on localhost, so neither the 855 simulator nor QEMU is exposed to any outside network. 856 857 See the "lanserv/README.vm" file in the OpenIPMI library for more 858 details on the external interface. 859 860``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]`` 861 Add a KCS IPMI interafce on the ISA bus. This also adds a 862 corresponding ACPI and SMBIOS entries, if appropriate. 863 864 ``bmc=id`` 865 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern 866 above. 867 868 ``ioport=val`` 869 Define the I/O address of the interface. The default is 0xca0 870 for KCS. 871 872 ``irq=val`` 873 Define the interrupt to use. The default is 5. To disable 874 interrupts, set this to 0. 875 876``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]`` 877 Like the KCS interface, but defines a BT interface. The default port 878 is 0xe4 and the default interrupt is 5. 879 880``-device pci-ipmi-kcs,bmc=id`` 881 Add a KCS IPMI interafce on the PCI bus. 882 883 ``bmc=id`` 884 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 885 886``-device pci-ipmi-bt,bmc=id`` 887 Like the KCS interface, but defines a BT interface on the PCI bus. 888ERST 889 890DEF("name", HAS_ARG, QEMU_OPTION_name, 891 "-name string1[,process=string2][,debug-threads=on|off]\n" 892 " set the name of the guest\n" 893 " string1 sets the window title and string2 the process name\n" 894 " When debug-threads is enabled, individual threads are given a separate name\n" 895 " NOTE: The thread names are for debugging and not a stable API.\n", 896 QEMU_ARCH_ALL) 897SRST 898``-name name`` 899 Sets the name of the guest. This name will be displayed in the SDL 900 window caption. The name will also be used for the VNC server. Also 901 optionally set the top visible process name in Linux. Naming of 902 individual threads can also be enabled on Linux to aid debugging. 903ERST 904 905DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 906 "-uuid %08x-%04x-%04x-%04x-%012x\n" 907 " specify machine UUID\n", QEMU_ARCH_ALL) 908SRST 909``-uuid uuid`` 910 Set system UUID. 911ERST 912 913DEFHEADING() 914 915DEFHEADING(Block device options:) 916 917DEF("fda", HAS_ARG, QEMU_OPTION_fda, 918 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 919DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 920SRST 921``-fda file`` 922 \ 923``-fdb file`` 924 Use file as floppy disk 0/1 image (see 925 :ref:`disk_005fimages`). 926ERST 927 928DEF("hda", HAS_ARG, QEMU_OPTION_hda, 929 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 930DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 931DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 932 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 933DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 934SRST 935``-hda file`` 936 \ 937``-hdb file`` 938 \ 939``-hdc file`` 940 \ 941``-hdd file`` 942 Use file as hard disk 0, 1, 2 or 3 image (see 943 :ref:`disk_005fimages`). 944ERST 945 946DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 947 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 948 QEMU_ARCH_ALL) 949SRST 950``-cdrom file`` 951 Use file as CD-ROM image (you cannot use ``-hdc`` and ``-cdrom`` at 952 the same time). You can use the host CD-ROM by using ``/dev/cdrom`` 953 as filename. 954ERST 955 956DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 957 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 958 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 959 " [,read-only=on|off][,auto-read-only=on|off]\n" 960 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 961 " [,driver specific parameters...]\n" 962 " configure a block backend\n", QEMU_ARCH_ALL) 963SRST 964``-blockdev option[,option[,option[,...]]]`` 965 Define a new block driver node. Some of the options apply to all 966 block drivers, other options are only accepted for a specific block 967 driver. See below for a list of generic options and options for the 968 most common block drivers. 969 970 Options that expect a reference to another node (e.g. ``file``) can 971 be given in two ways. Either you specify the node name of an already 972 existing node (file=node-name), or you define a new node inline, 973 adding options for the referenced node after a dot 974 (file.filename=path,file.aio=native). 975 976 A block driver node created with ``-blockdev`` can be used for a 977 guest device by specifying its node name for the ``drive`` property 978 in a ``-device`` argument that defines a block device. 979 980 ``Valid options for any block driver node:`` 981 ``driver`` 982 Specifies the block driver to use for the given node. 983 984 ``node-name`` 985 This defines the name of the block driver node by which it 986 will be referenced later. The name must be unique, i.e. it 987 must not match the name of a different block driver node, or 988 (if you use ``-drive`` as well) the ID of a drive. 989 990 If no node name is specified, it is automatically generated. 991 The generated node name is not intended to be predictable 992 and changes between QEMU invocations. For the top level, an 993 explicit node name must be specified. 994 995 ``read-only`` 996 Open the node read-only. Guest write attempts will fail. 997 998 Note that some block drivers support only read-only access, 999 either generally or in certain configurations. In this case, 1000 the default value ``read-only=off`` does not work and the 1001 option must be specified explicitly. 1002 1003 ``auto-read-only`` 1004 If ``auto-read-only=on`` is set, QEMU may fall back to 1005 read-only usage even when ``read-only=off`` is requested, or 1006 even switch between modes as needed, e.g. depending on 1007 whether the image file is writable or whether a writing user 1008 is attached to the node. 1009 1010 ``force-share`` 1011 Override the image locking system of QEMU by forcing the 1012 node to utilize weaker shared access for permissions where 1013 it would normally request exclusive access. When there is 1014 the potential for multiple instances to have the same file 1015 open (whether this invocation of QEMU is the first or the 1016 second instance), both instances must permit shared access 1017 for the second instance to succeed at opening the file. 1018 1019 Enabling ``force-share=on`` requires ``read-only=on``. 1020 1021 ``cache.direct`` 1022 The host page cache can be avoided with ``cache.direct=on``. 1023 This will attempt to do disk IO directly to the guest's 1024 memory. QEMU may still perform an internal copy of the data. 1025 1026 ``cache.no-flush`` 1027 In case you don't care about data integrity over host 1028 failures, you can use ``cache.no-flush=on``. This option 1029 tells QEMU that it never needs to write any data to the disk 1030 but can instead keep things in cache. If anything goes 1031 wrong, like your host losing power, the disk storage getting 1032 disconnected accidentally, etc. your image will most 1033 probably be rendered unusable. 1034 1035 ``discard=discard`` 1036 discard is one of "ignore" (or "off") or "unmap" (or "on") 1037 and controls whether ``discard`` (also known as ``trim`` or 1038 ``unmap``) requests are ignored or passed to the filesystem. 1039 Some machine types may not support discard requests. 1040 1041 ``detect-zeroes=detect-zeroes`` 1042 detect-zeroes is "off", "on" or "unmap" and enables the 1043 automatic conversion of plain zero writes by the OS to 1044 driver specific optimized zero write commands. You may even 1045 choose "unmap" if discard is set to "unmap" to allow a zero 1046 write to be converted to an ``unmap`` operation. 1047 1048 ``Driver-specific options for file`` 1049 This is the protocol-level block driver for accessing regular 1050 files. 1051 1052 ``filename`` 1053 The path to the image file in the local filesystem 1054 1055 ``aio`` 1056 Specifies the AIO backend (threads/native, default: threads) 1057 1058 ``locking`` 1059 Specifies whether the image file is protected with Linux OFD 1060 / POSIX locks. The default is to use the Linux Open File 1061 Descriptor API if available, otherwise no lock is applied. 1062 (auto/on/off, default: auto) 1063 1064 Example: 1065 1066 :: 1067 1068 -blockdev driver=file,node-name=disk,filename=disk.img 1069 1070 ``Driver-specific options for raw`` 1071 This is the image format block driver for raw images. It is 1072 usually stacked on top of a protocol level block driver such as 1073 ``file``. 1074 1075 ``file`` 1076 Reference to or definition of the data source block driver 1077 node (e.g. a ``file`` driver node) 1078 1079 Example 1: 1080 1081 :: 1082 1083 -blockdev driver=file,node-name=disk_file,filename=disk.img 1084 -blockdev driver=raw,node-name=disk,file=disk_file 1085 1086 Example 2: 1087 1088 :: 1089 1090 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1091 1092 ``Driver-specific options for qcow2`` 1093 This is the image format block driver for qcow2 images. It is 1094 usually stacked on top of a protocol level block driver such as 1095 ``file``. 1096 1097 ``file`` 1098 Reference to or definition of the data source block driver 1099 node (e.g. a ``file`` driver node) 1100 1101 ``backing`` 1102 Reference to or definition of the backing file block device 1103 (default is taken from the image file). It is allowed to 1104 pass ``null`` here in order to disable the default backing 1105 file. 1106 1107 ``lazy-refcounts`` 1108 Whether to enable the lazy refcounts feature (on/off; 1109 default is taken from the image file) 1110 1111 ``cache-size`` 1112 The maximum total size of the L2 table and refcount block 1113 caches in bytes (default: the sum of l2-cache-size and 1114 refcount-cache-size) 1115 1116 ``l2-cache-size`` 1117 The maximum size of the L2 table cache in bytes (default: if 1118 cache-size is not specified - 32M on Linux platforms, and 8M 1119 on non-Linux platforms; otherwise, as large as possible 1120 within the cache-size, while permitting the requested or the 1121 minimal refcount cache size) 1122 1123 ``refcount-cache-size`` 1124 The maximum size of the refcount block cache in bytes 1125 (default: 4 times the cluster size; or if cache-size is 1126 specified, the part of it which is not used for the L2 1127 cache) 1128 1129 ``cache-clean-interval`` 1130 Clean unused entries in the L2 and refcount caches. The 1131 interval is in seconds. The default value is 600 on 1132 supporting platforms, and 0 on other platforms. Setting it 1133 to 0 disables this feature. 1134 1135 ``pass-discard-request`` 1136 Whether discard requests to the qcow2 device should be 1137 forwarded to the data source (on/off; default: on if 1138 discard=unmap is specified, off otherwise) 1139 1140 ``pass-discard-snapshot`` 1141 Whether discard requests for the data source should be 1142 issued when a snapshot operation (e.g. deleting a snapshot) 1143 frees clusters in the qcow2 file (on/off; default: on) 1144 1145 ``pass-discard-other`` 1146 Whether discard requests for the data source should be 1147 issued on other occasions where a cluster gets freed 1148 (on/off; default: off) 1149 1150 ``overlap-check`` 1151 Which overlap checks to perform for writes to the image 1152 (none/constant/cached/all; default: cached). For details or 1153 finer granularity control refer to the QAPI documentation of 1154 ``blockdev-add``. 1155 1156 Example 1: 1157 1158 :: 1159 1160 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1161 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1162 1163 Example 2: 1164 1165 :: 1166 1167 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1168 1169 ``Driver-specific options for other drivers`` 1170 Please refer to the QAPI documentation of the ``blockdev-add`` 1171 QMP command. 1172ERST 1173 1174DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1175 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1176 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1177 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1178 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 1179 " [,readonly=on|off][,copy-on-read=on|off]\n" 1180 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1181 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1182 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1183 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1184 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1185 " [[,iops_size=is]]\n" 1186 " [[,group=g]]\n" 1187 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1188SRST 1189``-drive option[,option[,option[,...]]]`` 1190 Define a new drive. This includes creating a block driver node (the 1191 backend) as well as a guest device, and is mostly a shortcut for 1192 defining the corresponding ``-blockdev`` and ``-device`` options. 1193 1194 ``-drive`` accepts all options that are accepted by ``-blockdev``. 1195 In addition, it knows the following options: 1196 1197 ``file=file`` 1198 This option defines which disk image (see 1199 :ref:`disk_005fimages`) to use with this drive. If 1200 the filename contains comma, you must double it (for instance, 1201 "file=my,,file" to use file "my,file"). 1202 1203 Special files such as iSCSI devices can be specified using 1204 protocol specific URLs. See the section for "Device URL Syntax" 1205 for more information. 1206 1207 ``if=interface`` 1208 This option defines on which type on interface the drive is 1209 connected. Available types are: ide, scsi, sd, mtd, floppy, 1210 pflash, virtio, none. 1211 1212 ``bus=bus,unit=unit`` 1213 These options define where is connected the drive by defining 1214 the bus number and the unit id. 1215 1216 ``index=index`` 1217 This option defines where is connected the drive by using an 1218 index in the list of available connectors of a given interface 1219 type. 1220 1221 ``media=media`` 1222 This option defines the type of the media: disk or cdrom. 1223 1224 ``snapshot=snapshot`` 1225 snapshot is "on" or "off" and controls snapshot mode for the 1226 given drive (see ``-snapshot``). 1227 1228 ``cache=cache`` 1229 cache is "none", "writeback", "unsafe", "directsync" or 1230 "writethrough" and controls how the host cache is used to access 1231 block data. This is a shortcut that sets the ``cache.direct`` 1232 and ``cache.no-flush`` options (as in ``-blockdev``), and 1233 additionally ``cache.writeback``, which provides a default for 1234 the ``write-cache`` option of block guest devices (as in 1235 ``-device``). The modes correspond to the following settings: 1236 1237 ============= =============== ============ ============== 1238 \ cache.writeback cache.direct cache.no-flush 1239 ============= =============== ============ ============== 1240 writeback on off off 1241 none on on off 1242 writethrough off off off 1243 directsync off on off 1244 unsafe on off on 1245 ============= =============== ============ ============== 1246 1247 The default mode is ``cache=writeback``. 1248 1249 ``aio=aio`` 1250 aio is "threads", or "native" and selects between pthread based 1251 disk I/O and native Linux AIO. 1252 1253 ``format=format`` 1254 Specify which disk format will be used rather than detecting the 1255 format. Can be used to specify format=raw to avoid interpreting 1256 an untrusted format header. 1257 1258 ``werror=action,rerror=action`` 1259 Specify which action to take on write and read errors. Valid 1260 actions are: "ignore" (ignore the error and try to continue), 1261 "stop" (pause QEMU), "report" (report the error to the guest), 1262 "enospc" (pause QEMU only if the host disk is full; report the 1263 error to the guest otherwise). The default setting is 1264 ``werror=enospc`` and ``rerror=report``. 1265 1266 ``copy-on-read=copy-on-read`` 1267 copy-on-read is "on" or "off" and enables whether to copy read 1268 backing file sectors into the image file. 1269 1270 ``bps=b,bps_rd=r,bps_wr=w`` 1271 Specify bandwidth throttling limits in bytes per second, either 1272 for all request types or for reads or writes only. Small values 1273 can lead to timeouts or hangs inside the guest. A safe minimum 1274 for disks is 2 MB/s. 1275 1276 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm`` 1277 Specify bursts in bytes per second, either for all request types 1278 or for reads or writes only. Bursts allow the guest I/O to spike 1279 above the limit temporarily. 1280 1281 ``iops=i,iops_rd=r,iops_wr=w`` 1282 Specify request rate limits in requests per second, either for 1283 all request types or for reads or writes only. 1284 1285 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm`` 1286 Specify bursts in requests per second, either for all request 1287 types or for reads or writes only. Bursts allow the guest I/O to 1288 spike above the limit temporarily. 1289 1290 ``iops_size=is`` 1291 Let every is bytes of a request count as a new request for iops 1292 throttling purposes. Use this option to prevent guests from 1293 circumventing iops limits by sending fewer but larger requests. 1294 1295 ``group=g`` 1296 Join a throttling quota group with given name g. All drives that 1297 are members of the same group are accounted for together. Use 1298 this option to prevent guests from circumventing throttling 1299 limits by using many small disks instead of a single larger 1300 disk. 1301 1302 By default, the ``cache.writeback=on`` mode is used. It will report 1303 data writes as completed as soon as the data is present in the host 1304 page cache. This is safe as long as your guest OS makes sure to 1305 correctly flush disk caches where needed. If your guest OS does not 1306 handle volatile disk write caches correctly and your host crashes or 1307 loses power, then the guest may experience data corruption. 1308 1309 For such guests, you should consider using ``cache.writeback=off``. 1310 This means that the host page cache will be used to read and write 1311 data, but write notification will be sent to the guest only after 1312 QEMU has made sure to flush each write to the disk. Be aware that 1313 this has a major impact on performance. 1314 1315 When using the ``-snapshot`` option, unsafe caching is always used. 1316 1317 Copy-on-read avoids accessing the same backing file sectors 1318 repeatedly and is useful when the backing file is over a slow 1319 network. By default copy-on-read is off. 1320 1321 Instead of ``-cdrom`` you can use: 1322 1323 .. parsed-literal:: 1324 1325 |qemu_system| -drive file=file,index=2,media=cdrom 1326 1327 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use: 1328 1329 .. parsed-literal:: 1330 1331 |qemu_system| -drive file=file,index=0,media=disk 1332 |qemu_system| -drive file=file,index=1,media=disk 1333 |qemu_system| -drive file=file,index=2,media=disk 1334 |qemu_system| -drive file=file,index=3,media=disk 1335 1336 You can open an image using pre-opened file descriptors from an fd 1337 set: 1338 1339 .. parsed-literal:: 1340 1341 |qemu_system| \\ 1342 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 1343 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 1344 -drive file=/dev/fdset/2,index=0,media=disk 1345 1346 You can connect a CDROM to the slave of ide0: 1347 1348 .. parsed-literal:: 1349 1350 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom 1351 1352 If you don't specify the "file=" argument, you define an empty 1353 drive: 1354 1355 .. parsed-literal:: 1356 1357 |qemu_system_x86| -drive if=ide,index=1,media=cdrom 1358 1359 Instead of ``-fda``, ``-fdb``, you can use: 1360 1361 .. parsed-literal:: 1362 1363 |qemu_system_x86| -drive file=file,index=0,if=floppy 1364 |qemu_system_x86| -drive file=file,index=1,if=floppy 1365 1366 By default, interface is "ide" and index is automatically 1367 incremented: 1368 1369 .. parsed-literal:: 1370 1371 |qemu_system_x86| -drive file=a -drive file=b" 1372 1373 is interpreted like: 1374 1375 .. parsed-literal:: 1376 1377 |qemu_system_x86| -hda a -hdb b 1378ERST 1379 1380DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1381 "-mtdblock file use 'file' as on-board Flash memory image\n", 1382 QEMU_ARCH_ALL) 1383SRST 1384``-mtdblock file`` 1385 Use file as on-board Flash memory image. 1386ERST 1387 1388DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1389 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1390SRST 1391``-sd file`` 1392 Use file as SecureDigital card image. 1393ERST 1394 1395DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1396 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1397SRST 1398``-pflash file`` 1399 Use file as a parallel flash image. 1400ERST 1401 1402DEF("snapshot", 0, QEMU_OPTION_snapshot, 1403 "-snapshot write to temporary files instead of disk image files\n", 1404 QEMU_ARCH_ALL) 1405SRST 1406``-snapshot`` 1407 Write to temporary files instead of disk image files. In this case, 1408 the raw disk image you use is not written back. You can however 1409 force the write back by pressing C-a s (see 1410 :ref:`disk_005fimages`). 1411ERST 1412 1413DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1414 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1415 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1416 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1417 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1418 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1419 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1420 " [[,throttling.iops-size=is]]\n" 1421 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1422 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1423 "-fsdev synth,id=id\n", 1424 QEMU_ARCH_ALL) 1425 1426SRST 1427``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]`` 1428 \ 1429``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly]`` 1430 \ 1431``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly]`` 1432 \ 1433``-fsdev synth,id=id[,readonly]`` 1434 Define a new file system device. Valid options are: 1435 1436 ``local`` 1437 Accesses to the filesystem are done by QEMU. 1438 1439 ``proxy`` 1440 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1441 1442 ``synth`` 1443 Synthetic filesystem, only used by QTests. 1444 1445 ``id=id`` 1446 Specifies identifier for this device. 1447 1448 ``path=path`` 1449 Specifies the export path for the file system device. Files 1450 under this path will be available to the 9p client on the guest. 1451 1452 ``security_model=security_model`` 1453 Specifies the security model to be used for this export path. 1454 Supported security models are "passthrough", "mapped-xattr", 1455 "mapped-file" and "none". In "passthrough" security model, files 1456 are stored using the same credentials as they are created on the 1457 guest. This requires QEMU to run as root. In "mapped-xattr" 1458 security model, some of the file attributes like uid, gid, mode 1459 bits and link target are stored as file attributes. For 1460 "mapped-file" these attributes are stored in the hidden 1461 .virtfs\_metadata directory. Directories exported by this 1462 security model cannot interact with other unix tools. "none" 1463 security model is same as passthrough except the sever won't 1464 report failures if it fails to set file attributes like 1465 ownership. Security model is mandatory only for local fsdriver. 1466 Other fsdrivers (like proxy) don't take security model as a 1467 parameter. 1468 1469 ``writeout=writeout`` 1470 This is an optional argument. The only supported value is 1471 "immediate". This means that host page cache will be used to 1472 read and write data but write notification will be sent to the 1473 guest only when the data has been reported as written by the 1474 storage subsystem. 1475 1476 ``readonly`` 1477 Enables exporting 9p share as a readonly mount for guests. By 1478 default read-write access is given. 1479 1480 ``socket=socket`` 1481 Enables proxy filesystem driver to use passed socket file for 1482 communicating with virtfs-proxy-helper(1). 1483 1484 ``sock_fd=sock_fd`` 1485 Enables proxy filesystem driver to use passed socket descriptor 1486 for communicating with virtfs-proxy-helper(1). Usually a helper 1487 like libvirt will create socketpair and pass one of the fds as 1488 sock\_fd. 1489 1490 ``fmode=fmode`` 1491 Specifies the default mode for newly created files on the host. 1492 Works only with security models "mapped-xattr" and 1493 "mapped-file". 1494 1495 ``dmode=dmode`` 1496 Specifies the default mode for newly created directories on the 1497 host. Works only with security models "mapped-xattr" and 1498 "mapped-file". 1499 1500 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w`` 1501 Specify bandwidth throttling limits in bytes per second, either 1502 for all request types or for reads or writes only. 1503 1504 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm`` 1505 Specify bursts in bytes per second, either for all request types 1506 or for reads or writes only. Bursts allow the guest I/O to spike 1507 above the limit temporarily. 1508 1509 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w`` 1510 Specify request rate limits in requests per second, either for 1511 all request types or for reads or writes only. 1512 1513 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm`` 1514 Specify bursts in requests per second, either for all request 1515 types or for reads or writes only. Bursts allow the guest I/O to 1516 spike above the limit temporarily. 1517 1518 ``throttling.iops-size=is`` 1519 Let every is bytes of a request count as a new request for iops 1520 throttling purposes. 1521 1522 -fsdev option is used along with -device driver "virtio-9p-...". 1523 1524``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag`` 1525 Options for virtio-9p-... driver are: 1526 1527 ``type`` 1528 Specifies the variant to be used. Supported values are "pci", 1529 "ccw" or "device", depending on the machine type. 1530 1531 ``fsdev=id`` 1532 Specifies the id value specified along with -fsdev option. 1533 1534 ``mount_tag=mount_tag`` 1535 Specifies the tag name to be used by the guest to mount this 1536 export point. 1537ERST 1538 1539DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1540 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1541 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1542 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1543 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1544 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1545 QEMU_ARCH_ALL) 1546 1547SRST 1548``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]`` 1549 \ 1550``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly]`` 1551 \ 1552``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly]`` 1553 \ 1554``-virtfs synth,mount_tag=mount_tag`` 1555 Define a new virtual filesystem device and expose it to the guest using 1556 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain 1557 directory on host is made directly accessible by guest as a pass-through 1558 file system by using the 9P network protocol for communication between 1559 host and guests, if desired even accessible, shared by several guests 1560 simultaniously. 1561 1562 Note that ``-virtfs`` is actually just a convenience shortcut for its 1563 generalized form ``-fsdev -device virtio-9p-pci``. 1564 1565 The general form of pass-through file system options are: 1566 1567 ``local`` 1568 Accesses to the filesystem are done by QEMU. 1569 1570 ``proxy`` 1571 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1572 1573 ``synth`` 1574 Synthetic filesystem, only used by QTests. 1575 1576 ``id=id`` 1577 Specifies identifier for the filesystem device 1578 1579 ``path=path`` 1580 Specifies the export path for the file system device. Files 1581 under this path will be available to the 9p client on the guest. 1582 1583 ``security_model=security_model`` 1584 Specifies the security model to be used for this export path. 1585 Supported security models are "passthrough", "mapped-xattr", 1586 "mapped-file" and "none". In "passthrough" security model, files 1587 are stored using the same credentials as they are created on the 1588 guest. This requires QEMU to run as root. In "mapped-xattr" 1589 security model, some of the file attributes like uid, gid, mode 1590 bits and link target are stored as file attributes. For 1591 "mapped-file" these attributes are stored in the hidden 1592 .virtfs\_metadata directory. Directories exported by this 1593 security model cannot interact with other unix tools. "none" 1594 security model is same as passthrough except the sever won't 1595 report failures if it fails to set file attributes like 1596 ownership. Security model is mandatory only for local fsdriver. 1597 Other fsdrivers (like proxy) don't take security model as a 1598 parameter. 1599 1600 ``writeout=writeout`` 1601 This is an optional argument. The only supported value is 1602 "immediate". This means that host page cache will be used to 1603 read and write data but write notification will be sent to the 1604 guest only when the data has been reported as written by the 1605 storage subsystem. 1606 1607 ``readonly`` 1608 Enables exporting 9p share as a readonly mount for guests. By 1609 default read-write access is given. 1610 1611 ``socket=socket`` 1612 Enables proxy filesystem driver to use passed socket file for 1613 communicating with virtfs-proxy-helper(1). Usually a helper like 1614 libvirt will create socketpair and pass one of the fds as 1615 sock\_fd. 1616 1617 ``sock_fd`` 1618 Enables proxy filesystem driver to use passed 'sock\_fd' as the 1619 socket descriptor for interfacing with virtfs-proxy-helper(1). 1620 1621 ``fmode=fmode`` 1622 Specifies the default mode for newly created files on the host. 1623 Works only with security models "mapped-xattr" and 1624 "mapped-file". 1625 1626 ``dmode=dmode`` 1627 Specifies the default mode for newly created directories on the 1628 host. Works only with security models "mapped-xattr" and 1629 "mapped-file". 1630 1631 ``mount_tag=mount_tag`` 1632 Specifies the tag name to be used by the guest to mount this 1633 export point. 1634 1635 ``multidevs=multidevs`` 1636 Specifies how to deal with multiple devices being shared with a 1637 9p export. Supported behaviours are either "remap", "forbid" or 1638 "warn". The latter is the default behaviour on which virtfs 9p 1639 expects only one device to be shared with the same export, and 1640 if more than one device is shared and accessed via the same 9p 1641 export then only a warning message is logged (once) by qemu on 1642 host side. In order to avoid file ID collisions on guest you 1643 should either create a separate virtfs export for each device to 1644 be shared with guests (recommended way) or you might use "remap" 1645 instead which allows you to share multiple devices with only one 1646 export instead, which is achieved by remapping the original 1647 inode numbers from host to guest in a way that would prevent 1648 such collisions. Remapping inodes in such use cases is required 1649 because the original device IDs from host are never passed and 1650 exposed on guest. Instead all files of an export shared with 1651 virtfs always share the same device id on guest. So two files 1652 with identical inode numbers but from actually different devices 1653 on host would otherwise cause a file ID collision and hence 1654 potential misbehaviours on guest. "forbid" on the other hand 1655 assumes like "warn" that only one device is shared by the same 1656 export, however it will not only log a warning message but also 1657 deny access to additional devices on guest. Note though that 1658 "forbid" does currently not block all possible file access 1659 operations (e.g. readdir() would still return entries from other 1660 devices). 1661ERST 1662 1663DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1664 "-iscsi [user=user][,password=password]\n" 1665 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1666 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1667 " [,timeout=timeout]\n" 1668 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1669 1670SRST 1671``-iscsi`` 1672 Configure iSCSI session parameters. 1673ERST 1674 1675DEFHEADING() 1676 1677DEFHEADING(USB options:) 1678 1679DEF("usb", 0, QEMU_OPTION_usb, 1680 "-usb enable on-board USB host controller (if not enabled by default)\n", 1681 QEMU_ARCH_ALL) 1682SRST 1683``-usb`` 1684 Enable USB emulation on machine types with an on-board USB host 1685 controller (if not enabled by default). Note that on-board USB host 1686 controllers may not support USB 3.0. In this case 1687 ``-device qemu-xhci`` can be used instead on machines with PCI. 1688ERST 1689 1690DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1691 "-usbdevice name add the host or guest USB device 'name'\n", 1692 QEMU_ARCH_ALL) 1693SRST 1694``-usbdevice devname`` 1695 Add the USB device devname. Note that this option is deprecated, 1696 please use ``-device usb-...`` instead. See 1697 :ref:`usb_005fdevices`. 1698 1699 ``mouse`` 1700 Virtual Mouse. This will override the PS/2 mouse emulation when 1701 activated. 1702 1703 ``tablet`` 1704 Pointer device that uses absolute coordinates (like a 1705 touchscreen). This means QEMU is able to report the mouse 1706 position without having to grab the mouse. Also overrides the 1707 PS/2 mouse emulation when activated. 1708 1709 ``braille`` 1710 Braille device. This will use BrlAPI to display the braille 1711 output on a real or fake device. 1712ERST 1713 1714DEFHEADING() 1715 1716DEFHEADING(Display options:) 1717 1718DEF("display", HAS_ARG, QEMU_OPTION_display, 1719#if defined(CONFIG_SPICE) 1720 "-display spice-app[,gl=on|off]\n" 1721#endif 1722#if defined(CONFIG_SDL) 1723 "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off]\n" 1724 " [,window_close=on|off][,gl=on|core|es|off]\n" 1725#endif 1726#if defined(CONFIG_GTK) 1727 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1728#endif 1729#if defined(CONFIG_VNC) 1730 "-display vnc=<display>[,<optargs>]\n" 1731#endif 1732#if defined(CONFIG_CURSES) 1733 "-display curses[,charset=<encoding>]\n" 1734#endif 1735#if defined(CONFIG_OPENGL) 1736 "-display egl-headless[,rendernode=<file>]\n" 1737#endif 1738 "-display none\n" 1739 " select display backend type\n" 1740 " The default display is equivalent to\n " 1741#if defined(CONFIG_GTK) 1742 "\"-display gtk\"\n" 1743#elif defined(CONFIG_SDL) 1744 "\"-display sdl\"\n" 1745#elif defined(CONFIG_COCOA) 1746 "\"-display cocoa\"\n" 1747#elif defined(CONFIG_VNC) 1748 "\"-vnc localhost:0,to=99,id=default\"\n" 1749#else 1750 "\"-display none\"\n" 1751#endif 1752 , QEMU_ARCH_ALL) 1753SRST 1754``-display type`` 1755 Select type of display to use. This option is a replacement for the 1756 old style -sdl/-curses/... options. Use ``-display help`` to list 1757 the available display types. Valid values for type are 1758 1759 ``sdl`` 1760 Display video output via SDL (usually in a separate graphics 1761 window; see the SDL documentation for other possibilities). 1762 1763 ``curses`` 1764 Display video output via curses. For graphics device models 1765 which support a text mode, QEMU can display this output using a 1766 curses/ncurses interface. Nothing is displayed when the graphics 1767 device is in graphical mode or if the graphics device does not 1768 support a text mode. Generally only the VGA device models 1769 support text mode. The font charset used by the guest can be 1770 specified with the ``charset`` option, for example 1771 ``charset=CP850`` for IBM CP850 encoding. The default is 1772 ``CP437``. 1773 1774 ``none`` 1775 Do not display video output. The guest will still see an 1776 emulated graphics card, but its output will not be displayed to 1777 the QEMU user. This option differs from the -nographic option in 1778 that it only affects what is done with video output; -nographic 1779 also changes the destination of the serial and parallel port 1780 data. 1781 1782 ``gtk`` 1783 Display video output in a GTK window. This interface provides 1784 drop-down menus and other UI elements to configure and control 1785 the VM during runtime. 1786 1787 ``vnc`` 1788 Start a VNC server on display <arg> 1789 1790 ``egl-headless`` 1791 Offload all OpenGL operations to a local DRI device. For any 1792 graphical display, this display needs to be paired with either 1793 VNC or SPICE displays. 1794 1795 ``spice-app`` 1796 Start QEMU as a Spice server and launch the default Spice client 1797 application. The Spice server will redirect the serial consoles 1798 and QEMU monitors. (Since 4.0) 1799ERST 1800 1801DEF("nographic", 0, QEMU_OPTION_nographic, 1802 "-nographic disable graphical output and redirect serial I/Os to console\n", 1803 QEMU_ARCH_ALL) 1804SRST 1805``-nographic`` 1806 Normally, if QEMU is compiled with graphical window support, it 1807 displays output such as guest graphics, guest console, and the QEMU 1808 monitor in a window. With this option, you can totally disable 1809 graphical output so that QEMU is a simple command line application. 1810 The emulated serial port is redirected on the console and muxed with 1811 the monitor (unless redirected elsewhere explicitly). Therefore, you 1812 can still use QEMU to debug a Linux kernel with a serial console. 1813 Use C-a h for help on switching between the console and monitor. 1814ERST 1815 1816DEF("curses", 0, QEMU_OPTION_curses, 1817 "-curses shorthand for -display curses\n", 1818 QEMU_ARCH_ALL) 1819SRST 1820``-curses`` 1821 Normally, if QEMU is compiled with graphical window support, it 1822 displays output such as guest graphics, guest console, and the QEMU 1823 monitor in a window. With this option, QEMU can display the VGA 1824 output when in text mode using a curses/ncurses interface. Nothing 1825 is displayed in graphical mode. 1826ERST 1827 1828DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1829 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1830 QEMU_ARCH_ALL) 1831SRST 1832``-alt-grab`` 1833 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that 1834 this also affects the special keys (for fullscreen, monitor-mode 1835 switching, etc). 1836ERST 1837 1838DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1839 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1840 QEMU_ARCH_ALL) 1841SRST 1842``-ctrl-grab`` 1843 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this 1844 also affects the special keys (for fullscreen, monitor-mode 1845 switching, etc). 1846ERST 1847 1848DEF("no-quit", 0, QEMU_OPTION_no_quit, 1849 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1850SRST 1851``-no-quit`` 1852 Disable SDL window close capability. 1853ERST 1854 1855DEF("sdl", 0, QEMU_OPTION_sdl, 1856 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1857SRST 1858``-sdl`` 1859 Enable SDL. 1860ERST 1861 1862DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1863 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1864 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1865 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1866 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1867 " [,tls-ciphers=<list>]\n" 1868 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1869 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1870 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1871 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1872 " [,jpeg-wan-compression=[auto|never|always]]\n" 1873 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1874 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1875 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1876 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1877 " [,gl=[on|off]][,rendernode=<file>]\n" 1878 " enable spice\n" 1879 " at least one of {port, tls-port} is mandatory\n", 1880 QEMU_ARCH_ALL) 1881SRST 1882``-spice option[,option[,...]]`` 1883 Enable the spice remote desktop protocol. Valid options are 1884 1885 ``port=<nr>`` 1886 Set the TCP port spice is listening on for plaintext channels. 1887 1888 ``addr=<addr>`` 1889 Set the IP address spice is listening on. Default is any 1890 address. 1891 1892 ``ipv4``; \ ``ipv6``; \ ``unix`` 1893 Force using the specified IP version. 1894 1895 ``password=<secret>`` 1896 Set the password you need to authenticate. 1897 1898 ``sasl`` 1899 Require that the client use SASL to authenticate with the spice. 1900 The exact choice of authentication method used is controlled 1901 from the system / user's SASL configuration file for the 'qemu' 1902 service. This is typically found in /etc/sasl2/qemu.conf. If 1903 running QEMU as an unprivileged user, an environment variable 1904 SASL\_CONF\_PATH can be used to make it search alternate 1905 locations for the service config. While some SASL auth methods 1906 can also provide data encryption (eg GSSAPI), it is recommended 1907 that SASL always be combined with the 'tls' and 'x509' settings 1908 to enable use of SSL and server certificates. This ensures a 1909 data encryption preventing compromise of authentication 1910 credentials. 1911 1912 ``disable-ticketing`` 1913 Allow client connects without authentication. 1914 1915 ``disable-copy-paste`` 1916 Disable copy paste between the client and the guest. 1917 1918 ``disable-agent-file-xfer`` 1919 Disable spice-vdagent based file-xfer between the client and the 1920 guest. 1921 1922 ``tls-port=<nr>`` 1923 Set the TCP port spice is listening on for encrypted channels. 1924 1925 ``x509-dir=<dir>`` 1926 Set the x509 file directory. Expects same filenames as -vnc 1927 $display,x509=$dir 1928 1929 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>`` 1930 The x509 file names can also be configured individually. 1931 1932 ``tls-ciphers=<list>`` 1933 Specify which ciphers to use. 1934 1935 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]`` 1936 Force specific channel to be used with or without TLS 1937 encryption. The options can be specified multiple times to 1938 configure multiple channels. The special name "default" can be 1939 used to set the default mode. For channels which are not 1940 explicitly forced into one mode the spice client is allowed to 1941 pick tls/plaintext as he pleases. 1942 1943 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]`` 1944 Configure image compression (lossless). Default is auto\_glz. 1945 1946 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]`` 1947 Configure wan image compression (lossy for slow links). Default 1948 is auto. 1949 1950 ``streaming-video=[off|all|filter]`` 1951 Configure video stream detection. Default is off. 1952 1953 ``agent-mouse=[on|off]`` 1954 Enable/disable passing mouse events via vdagent. Default is on. 1955 1956 ``playback-compression=[on|off]`` 1957 Enable/disable audio stream compression (using celt 0.5.1). 1958 Default is on. 1959 1960 ``seamless-migration=[on|off]`` 1961 Enable/disable spice seamless migration. Default is off. 1962 1963 ``gl=[on|off]`` 1964 Enable/disable OpenGL context. Default is off. 1965 1966 ``rendernode=<file>`` 1967 DRM render node for OpenGL rendering. If not specified, it will 1968 pick the first available. (Since 2.9) 1969ERST 1970 1971DEF("portrait", 0, QEMU_OPTION_portrait, 1972 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1973 QEMU_ARCH_ALL) 1974SRST 1975``-portrait`` 1976 Rotate graphical output 90 deg left (only PXA LCD). 1977ERST 1978 1979DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1980 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1981 QEMU_ARCH_ALL) 1982SRST 1983``-rotate deg`` 1984 Rotate graphical output some deg left (only PXA LCD). 1985ERST 1986 1987DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1988 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1989 " select video card type\n", QEMU_ARCH_ALL) 1990SRST 1991``-vga type`` 1992 Select type of VGA card to emulate. Valid values for type are 1993 1994 ``cirrus`` 1995 Cirrus Logic GD5446 Video card. All Windows versions starting 1996 from Windows 95 should recognize and use this graphic card. For 1997 optimal performances, use 16 bit color depth in the guest and 1998 the host OS. (This card was the default before QEMU 2.2) 1999 2000 ``std`` 2001 Standard VGA card with Bochs VBE extensions. If your guest OS 2002 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if 2003 you want to use high resolution modes (>= 1280x1024x16) then you 2004 should use this option. (This card is the default since QEMU 2005 2.2) 2006 2007 ``vmware`` 2008 VMWare SVGA-II compatible adapter. Use it if you have 2009 sufficiently recent XFree86/XOrg server or Windows guest with a 2010 driver for this card. 2011 2012 ``qxl`` 2013 QXL paravirtual graphic card. It is VGA compatible (including 2014 VESA 2.0 VBE support). Works best with qxl guest drivers 2015 installed though. Recommended choice when using the spice 2016 protocol. 2017 2018 ``tcx`` 2019 (sun4m only) Sun TCX framebuffer. This is the default 2020 framebuffer for sun4m machines and offers both 8-bit and 24-bit 2021 colour depths at a fixed resolution of 1024x768. 2022 2023 ``cg3`` 2024 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit 2025 framebuffer for sun4m machines available in both 1024x768 2026 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people 2027 wishing to run older Solaris versions. 2028 2029 ``virtio`` 2030 Virtio VGA card. 2031 2032 ``none`` 2033 Disable VGA card. 2034ERST 2035 2036DEF("full-screen", 0, QEMU_OPTION_full_screen, 2037 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 2038SRST 2039``-full-screen`` 2040 Start in full screen. 2041ERST 2042 2043DEF("g", HAS_ARG, QEMU_OPTION_g , 2044 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 2045 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 2046SRST 2047``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]`` 2048 Set the initial graphical resolution and depth (PPC, SPARC only). 2049 2050 For PPC the default is 800x600x32. 2051 2052 For SPARC with the TCX graphics device, the default is 1024x768x8 2053 with the option of 1024x768x24. For cgthree, the default is 2054 1024x768x8 with the option of 1152x900x8 for people who wish to use 2055 OBP. 2056ERST 2057 2058DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 2059 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 2060SRST 2061``-vnc display[,option[,option[,...]]]`` 2062 Normally, if QEMU is compiled with graphical window support, it 2063 displays output such as guest graphics, guest console, and the QEMU 2064 monitor in a window. With this option, you can have QEMU listen on 2065 VNC display display and redirect the VGA display over the VNC 2066 session. It is very useful to enable the usb tablet device when 2067 using this option (option ``-device usb-tablet``). When using the 2068 VNC display, you must use the ``-k`` parameter to set the keyboard 2069 layout if you are not using en-us. Valid syntax for the display is 2070 2071 ``to=L`` 2072 With this option, QEMU will try next available VNC displays, 2073 until the number L, if the origianlly defined "-vnc display" is 2074 not available, e.g. port 5900+display is already used by another 2075 application. By default, to=0. 2076 2077 ``host:d`` 2078 TCP connections will only be allowed from host on display d. By 2079 convention the TCP port is 5900+d. Optionally, host can be 2080 omitted in which case the server will accept connections from 2081 any host. 2082 2083 ``unix:path`` 2084 Connections will be allowed over UNIX domain sockets where path 2085 is the location of a unix socket to listen for connections on. 2086 2087 ``none`` 2088 VNC is initialized but not started. The monitor ``change`` 2089 command can be used to later start the VNC server. 2090 2091 Following the display value there may be one or more option flags 2092 separated by commas. Valid options are 2093 2094 ``reverse`` 2095 Connect to a listening VNC client via a "reverse" connection. 2096 The client is specified by the display. For reverse network 2097 connections (host:d,``reverse``), the d argument is a TCP port 2098 number, not a display number. 2099 2100 ``websocket`` 2101 Opens an additional TCP listening port dedicated to VNC 2102 Websocket connections. If a bare websocket option is given, the 2103 Websocket port is 5700+display. An alternative port can be 2104 specified with the syntax ``websocket``\ =port. 2105 2106 If host is specified connections will only be allowed from this 2107 host. It is possible to control the websocket listen address 2108 independently, using the syntax ``websocket``\ =host:port. 2109 2110 If no TLS credentials are provided, the websocket connection 2111 runs in unencrypted mode. If TLS credentials are provided, the 2112 websocket connection requires encrypted client connections. 2113 2114 ``password`` 2115 Require that password based authentication is used for client 2116 connections. 2117 2118 The password must be set separately using the ``set_password`` 2119 command in the :ref:`pcsys_005fmonitor`. The 2120 syntax to change your password is: 2121 ``set_password <protocol> <password>`` where <protocol> could be 2122 either "vnc" or "spice". 2123 2124 If you would like to change <protocol> password expiration, you 2125 should use ``expire_password <protocol> <expiration-time>`` 2126 where expiration time could be one of the following options: 2127 now, never, +seconds or UNIX time of expiration, e.g. +60 to 2128 make password expire in 60 seconds, or 1335196800 to make 2129 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for 2130 this date and time). 2131 2132 You can also use keywords "now" or "never" for the expiration 2133 time to allow <protocol> password to expire immediately or never 2134 expire. 2135 2136 ``tls-creds=ID`` 2137 Provides the ID of a set of TLS credentials to use to secure the 2138 VNC server. They will apply to both the normal VNC server socket 2139 and the websocket socket (if enabled). Setting TLS credentials 2140 will cause the VNC server socket to enable the VeNCrypt auth 2141 mechanism. The credentials should have been previously created 2142 using the ``-object tls-creds`` argument. 2143 2144 ``tls-authz=ID`` 2145 Provides the ID of the QAuthZ authorization object against which 2146 the client's x509 distinguished name will validated. This object 2147 is only resolved at time of use, so can be deleted and recreated 2148 on the fly while the VNC server is active. If missing, it will 2149 default to denying access. 2150 2151 ``sasl`` 2152 Require that the client use SASL to authenticate with the VNC 2153 server. The exact choice of authentication method used is 2154 controlled from the system / user's SASL configuration file for 2155 the 'qemu' service. This is typically found in 2156 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, 2157 an environment variable SASL\_CONF\_PATH can be used to make it 2158 search alternate locations for the service config. While some 2159 SASL auth methods can also provide data encryption (eg GSSAPI), 2160 it is recommended that SASL always be combined with the 'tls' 2161 and 'x509' settings to enable use of SSL and server 2162 certificates. This ensures a data encryption preventing 2163 compromise of authentication credentials. See the 2164 :ref:`vnc_005fsecurity` section for details on 2165 using SASL authentication. 2166 2167 ``sasl-authz=ID`` 2168 Provides the ID of the QAuthZ authorization object against which 2169 the client's SASL username will validated. This object is only 2170 resolved at time of use, so can be deleted and recreated on the 2171 fly while the VNC server is active. If missing, it will default 2172 to denying access. 2173 2174 ``acl`` 2175 Legacy method for enabling authorization of clients against the 2176 x509 distinguished name and SASL username. It results in the 2177 creation of two ``authz-list`` objects with IDs of 2178 ``vnc.username`` and ``vnc.x509dname``. The rules for these 2179 objects must be configured with the HMP ACL commands. 2180 2181 This option is deprecated and should no longer be used. The new 2182 ``sasl-authz`` and ``tls-authz`` options are a replacement. 2183 2184 ``lossy`` 2185 Enable lossy compression methods (gradient, JPEG, ...). If this 2186 option is set, VNC client may receive lossy framebuffer updates 2187 depending on its encoding settings. Enabling this option can 2188 save a lot of bandwidth at the expense of quality. 2189 2190 ``non-adaptive`` 2191 Disable adaptive encodings. Adaptive encodings are enabled by 2192 default. An adaptive encoding will try to detect frequently 2193 updated screen regions, and send updates in these regions using 2194 a lossy encoding (like JPEG). This can be really helpful to save 2195 bandwidth when playing videos. Disabling adaptive encodings 2196 restores the original static behavior of encodings like Tight. 2197 2198 ``share=[allow-exclusive|force-shared|ignore]`` 2199 Set display sharing policy. 'allow-exclusive' allows clients to 2200 ask for exclusive access. As suggested by the rfb spec this is 2201 implemented by dropping other connections. Connecting multiple 2202 clients in parallel requires all clients asking for a shared 2203 session (vncviewer: -shared switch). This is the default. 2204 'force-shared' disables exclusive client access. Useful for 2205 shared desktop sessions, where you don't want someone forgetting 2206 specify -shared disconnect everybody else. 'ignore' completely 2207 ignores the shared flag and allows everybody connect 2208 unconditionally. Doesn't conform to the rfb spec but is 2209 traditional QEMU behavior. 2210 2211 ``key-delay-ms`` 2212 Set keyboard delay, for key down and key up events, in 2213 milliseconds. Default is 10. Keyboards are low-bandwidth 2214 devices, so this slowdown can help the device and guest to keep 2215 up and not lose events in case events are arriving in bulk. 2216 Possible causes for the latter are flaky network connections, or 2217 scripts for automated testing. 2218 2219 ``audiodev=audiodev`` 2220 Use the specified audiodev when the VNC client requests audio 2221 transmission. When not using an -audiodev argument, this option 2222 must be omitted, otherwise is must be present and specify a 2223 valid audiodev. 2224ERST 2225 2226ARCHHEADING(, QEMU_ARCH_I386) 2227 2228ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2229 2230DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2231 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2232 QEMU_ARCH_I386) 2233SRST 2234``-win2k-hack`` 2235 Use it when installing Windows 2000 to avoid a disk full bug. After 2236 Windows 2000 is installed, you no longer need this option (this 2237 option slows down the IDE transfers). 2238ERST 2239 2240DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2241 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2242 QEMU_ARCH_I386) 2243SRST 2244``-no-fd-bootchk`` 2245 Disable boot signature checking for floppy disks in BIOS. May be 2246 needed to boot from old floppy disks. 2247ERST 2248 2249DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2250 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2251SRST 2252``-no-acpi`` 2253 Disable ACPI (Advanced Configuration and Power Interface) support. 2254 Use it if your guest OS complains about ACPI problems (PC target 2255 machine only). 2256ERST 2257 2258DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2259 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2260SRST 2261``-no-hpet`` 2262 Disable HPET support. 2263ERST 2264 2265DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2266 "-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" 2267 " ACPI table description\n", QEMU_ARCH_I386) 2268SRST 2269``-acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n] [,asl_compiler_id=str][,asl_compiler_rev=n][,data=file1[:file2]...]`` 2270 Add ACPI table with specified header fields and context from 2271 specified files. For file=, take whole ACPI table from the specified 2272 files, including all ACPI headers (possible overridden by other 2273 options). For data=, only data portion of the table is used, all 2274 header information is specified in the command line. If a SLIC table 2275 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id 2276 fields will override the same in the RSDT and the FADT (a.k.a. 2277 FACP), in order to ensure the field matches required by the 2278 Microsoft SLIC spec and the ACPI spec. 2279ERST 2280 2281DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2282 "-smbios file=binary\n" 2283 " load SMBIOS entry from binary file\n" 2284 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2285 " [,uefi=on|off]\n" 2286 " specify SMBIOS type 0 fields\n" 2287 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2288 " [,uuid=uuid][,sku=str][,family=str]\n" 2289 " specify SMBIOS type 1 fields\n" 2290 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2291 " [,asset=str][,location=str]\n" 2292 " specify SMBIOS type 2 fields\n" 2293 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2294 " [,sku=str]\n" 2295 " specify SMBIOS type 3 fields\n" 2296 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2297 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n" 2298 " specify SMBIOS type 4 fields\n" 2299 "-smbios type=11[,value=str][,path=filename]\n" 2300 " specify SMBIOS type 11 fields\n" 2301 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2302 " [,asset=str][,part=str][,speed=%d]\n" 2303 " specify SMBIOS type 17 fields\n", 2304 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2305SRST 2306``-smbios file=binary`` 2307 Load SMBIOS entry from binary file. 2308 2309``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]`` 2310 Specify SMBIOS type 0 fields 2311 2312``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]`` 2313 Specify SMBIOS type 1 fields 2314 2315``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]`` 2316 Specify SMBIOS type 2 fields 2317 2318``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]`` 2319 Specify SMBIOS type 3 fields 2320 2321``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str]`` 2322 Specify SMBIOS type 4 fields 2323 2324``-smbios type=11[,value=str][,path=filename]`` 2325 Specify SMBIOS type 11 fields 2326 2327 This argument can be repeated multiple times, and values are added in the order they are parsed. 2328 Applications intending to use OEM strings data are encouraged to use their application name as 2329 a prefix for the value string. This facilitates passing information for multiple applications 2330 concurrently. 2331 2332 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax 2333 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes. 2334 2335 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to 2336 the SMBIOS table in the order in which they appear. 2337 2338 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535 2339 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the 2340 guest. Instead it should be used as a indicator to inform the guest where to locate the real 2341 data set, for example, by specifying the serial ID of a block device. 2342 2343 An example passing three strings is 2344 2345 .. parsed-literal:: 2346 2347 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\ 2348 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\ 2349 path=/some/file/with/oemstringsdata.txt 2350 2351 In the guest OS this is visible with the ``dmidecode`` command 2352 2353 .. parsed-literal:: 2354 2355 $ dmidecode -t 11 2356 Handle 0x0E00, DMI type 11, 5 bytes 2357 OEM Strings 2358 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/ 2359 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os 2360 String 3: myapp:some extra data 2361 2362 2363``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]`` 2364 Specify SMBIOS type 17 fields 2365ERST 2366 2367DEFHEADING() 2368 2369DEFHEADING(Network options:) 2370 2371DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2372#ifdef CONFIG_SLIRP 2373 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2374 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2375 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2376 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2377 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2378#ifndef _WIN32 2379 "[,smb=dir[,smbserver=addr]]\n" 2380#endif 2381 " configure a user mode network backend with ID 'str',\n" 2382 " its DHCP server and optional services\n" 2383#endif 2384#ifdef _WIN32 2385 "-netdev tap,id=str,ifname=name\n" 2386 " configure a host TAP network backend with ID 'str'\n" 2387#else 2388 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2389 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2390 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2391 " [,poll-us=n]\n" 2392 " configure a host TAP network backend with ID 'str'\n" 2393 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2394 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2395 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2396 " to deconfigure it\n" 2397 " use '[down]script=no' to disable script execution\n" 2398 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2399 " configure it\n" 2400 " use 'fd=h' to connect to an already opened TAP interface\n" 2401 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2402 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2403 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2404 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2405 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2406 " use vhost=on to enable experimental in kernel accelerator\n" 2407 " (only has effect for virtio guests which use MSIX)\n" 2408 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2409 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2410 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2411 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2412 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2413 " spent on busy polling for vhost net\n" 2414 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2415 " configure a host TAP network backend with ID 'str' that is\n" 2416 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2417 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2418#endif 2419#ifdef __linux__ 2420 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2421 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2422 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2423 " [,rxcookie=rxcookie][,offset=offset]\n" 2424 " configure a network backend with ID 'str' connected to\n" 2425 " an Ethernet over L2TPv3 pseudowire.\n" 2426 " Linux kernel 3.3+ as well as most routers can talk\n" 2427 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2428 " VM to a router and even VM to Host. It is a nearly-universal\n" 2429 " standard (RFC3931). Note - this implementation uses static\n" 2430 " pre-configured tunnels (same as the Linux kernel).\n" 2431 " use 'src=' to specify source address\n" 2432 " use 'dst=' to specify destination address\n" 2433 " use 'udp=on' to specify udp encapsulation\n" 2434 " use 'srcport=' to specify source udp port\n" 2435 " use 'dstport=' to specify destination udp port\n" 2436 " use 'ipv6=on' to force v6\n" 2437 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2438 " well as a weak security measure\n" 2439 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2440 " use 'txcookie=0x012345678' to specify a txcookie\n" 2441 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2442 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2443 " use 'pincounter=on' to work around broken counter handling in peer\n" 2444 " use 'offset=X' to add an extra offset between header and data\n" 2445#endif 2446 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2447 " configure a network backend to connect to another network\n" 2448 " using a socket connection\n" 2449 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2450 " configure a network backend to connect to a multicast maddr and port\n" 2451 " use 'localaddr=addr' to specify the host address to send packets from\n" 2452 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2453 " configure a network backend to connect to another network\n" 2454 " using an UDP tunnel\n" 2455#ifdef CONFIG_VDE 2456 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2457 " configure a network backend to connect to port 'n' of a vde switch\n" 2458 " running on host and listening for incoming connections on 'socketpath'.\n" 2459 " Use group 'groupname' and mode 'octalmode' to change default\n" 2460 " ownership and permissions for communication port.\n" 2461#endif 2462#ifdef CONFIG_NETMAP 2463 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2464 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2465 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2466 " netmap device, defaults to '/dev/netmap')\n" 2467#endif 2468#ifdef CONFIG_POSIX 2469 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2470 " configure a vhost-user network, backed by a chardev 'dev'\n" 2471#endif 2472#ifdef __linux__ 2473 "-netdev vhost-vdpa,id=str,vhostdev=/path/to/dev\n" 2474 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n" 2475#endif 2476 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2477 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2478DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2479 "-nic [tap|bridge|" 2480#ifdef CONFIG_SLIRP 2481 "user|" 2482#endif 2483#ifdef __linux__ 2484 "l2tpv3|" 2485#endif 2486#ifdef CONFIG_VDE 2487 "vde|" 2488#endif 2489#ifdef CONFIG_NETMAP 2490 "netmap|" 2491#endif 2492#ifdef CONFIG_POSIX 2493 "vhost-user|" 2494#endif 2495 "socket][,option][,...][mac=macaddr]\n" 2496 " initialize an on-board / default host NIC (using MAC address\n" 2497 " macaddr) and connect it to the given host network backend\n" 2498 "-nic none use it alone to have zero network devices (the default is to\n" 2499 " provided a 'user' network connection)\n", 2500 QEMU_ARCH_ALL) 2501DEF("net", HAS_ARG, QEMU_OPTION_net, 2502 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2503 " configure or create an on-board (or machine default) NIC and\n" 2504 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2505 "-net [" 2506#ifdef CONFIG_SLIRP 2507 "user|" 2508#endif 2509 "tap|" 2510 "bridge|" 2511#ifdef CONFIG_VDE 2512 "vde|" 2513#endif 2514#ifdef CONFIG_NETMAP 2515 "netmap|" 2516#endif 2517 "socket][,option][,option][,...]\n" 2518 " old way to initialize a host network interface\n" 2519 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2520SRST 2521``-nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]`` 2522 This option is a shortcut for configuring both the on-board 2523 (default) guest NIC hardware and the host network backend in one go. 2524 The host backend options are the same as with the corresponding 2525 ``-netdev`` options below. The guest NIC model can be set with 2526 ``model=modelname``. Use ``model=help`` to list the available device 2527 types. The hardware MAC address can be set with ``mac=macaddr``. 2528 2529 The following two example do exactly the same, to show how ``-nic`` 2530 can be used to shorten the command line length: 2531 2532 .. parsed-literal:: 2533 2534 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2535 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2536 2537``-nic none`` 2538 Indicate that no network devices should be configured. It is used to 2539 override the default configuration (default NIC with "user" host 2540 network backend) which is activated if no other networking options 2541 are provided. 2542 2543``-netdev user,id=id[,option][,option][,...]`` 2544 Configure user mode host network backend which requires no 2545 administrator privilege to run. Valid options are: 2546 2547 ``id=id`` 2548 Assign symbolic name for use in monitor commands. 2549 2550 ``ipv4=on|off and ipv6=on|off`` 2551 Specify that either IPv4 or IPv6 must be enabled. If neither is 2552 specified both protocols are enabled. 2553 2554 ``net=addr[/mask]`` 2555 Set IP network address the guest will see. Optionally specify 2556 the netmask, either in the form a.b.c.d or as number of valid 2557 top-most bits. Default is 10.0.2.0/24. 2558 2559 ``host=addr`` 2560 Specify the guest-visible address of the host. Default is the 2561 2nd IP in the guest network, i.e. x.x.x.2. 2562 2563 ``ipv6-net=addr[/int]`` 2564 Set IPv6 network address the guest will see (default is 2565 fec0::/64). The network prefix is given in the usual hexadecimal 2566 IPv6 address notation. The prefix size is optional, and is given 2567 as the number of valid top-most bits (default is 64). 2568 2569 ``ipv6-host=addr`` 2570 Specify the guest-visible IPv6 address of the host. Default is 2571 the 2nd IPv6 in the guest network, i.e. xxxx::2. 2572 2573 ``restrict=on|off`` 2574 If this option is enabled, the guest will be isolated, i.e. it 2575 will not be able to contact the host and no guest IP packets 2576 will be routed over the host to the outside. This option does 2577 not affect any explicitly set forwarding rules. 2578 2579 ``hostname=name`` 2580 Specifies the client hostname reported by the built-in DHCP 2581 server. 2582 2583 ``dhcpstart=addr`` 2584 Specify the first of the 16 IPs the built-in DHCP server can 2585 assign. Default is the 15th to 31st IP in the guest network, 2586 i.e. x.x.x.15 to x.x.x.31. 2587 2588 ``dns=addr`` 2589 Specify the guest-visible address of the virtual nameserver. The 2590 address must be different from the host address. Default is the 2591 3rd IP in the guest network, i.e. x.x.x.3. 2592 2593 ``ipv6-dns=addr`` 2594 Specify the guest-visible address of the IPv6 virtual 2595 nameserver. The address must be different from the host address. 2596 Default is the 3rd IP in the guest network, i.e. xxxx::3. 2597 2598 ``dnssearch=domain`` 2599 Provides an entry for the domain-search list sent by the 2600 built-in DHCP server. More than one domain suffix can be 2601 transmitted by specifying this option multiple times. If 2602 supported, this will cause the guest to automatically try to 2603 append the given domain suffix(es) in case a domain name can not 2604 be resolved. 2605 2606 Example: 2607 2608 .. parsed-literal:: 2609 2610 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2611 2612 ``domainname=domain`` 2613 Specifies the client domain name reported by the built-in DHCP 2614 server. 2615 2616 ``tftp=dir`` 2617 When using the user mode network stack, activate a built-in TFTP 2618 server. The files in dir will be exposed as the root of a TFTP 2619 server. The TFTP client on the guest must be configured in 2620 binary mode (use the command ``bin`` of the Unix TFTP client). 2621 2622 ``tftp-server-name=name`` 2623 In BOOTP reply, broadcast name as the "TFTP server name" 2624 (RFC2132 option 66). This can be used to advise the guest to 2625 load boot files or configurations from a different server than 2626 the host address. 2627 2628 ``bootfile=file`` 2629 When using the user mode network stack, broadcast file as the 2630 BOOTP filename. In conjunction with ``tftp``, this can be used 2631 to network boot a guest from a local directory. 2632 2633 Example (using pxelinux): 2634 2635 .. parsed-literal:: 2636 2637 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\ 2638 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2639 2640 ``smb=dir[,smbserver=addr]`` 2641 When using the user mode network stack, activate a built-in SMB 2642 server so that Windows OSes can access to the host files in 2643 ``dir`` transparently. The IP address of the SMB server can be 2644 set to addr. By default the 4th IP in the guest network is used, 2645 i.e. x.x.x.4. 2646 2647 In the guest Windows OS, the line: 2648 2649 :: 2650 2651 10.0.2.4 smbserver 2652 2653 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows 2654 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows 2655 NT/2000). 2656 2657 Then ``dir`` can be accessed in ``\\smbserver\qemu``. 2658 2659 Note that a SAMBA server must be installed on the host OS. 2660 2661 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport`` 2662 Redirect incoming TCP or UDP connections to the host port 2663 hostport to the guest IP address guestaddr on guest port 2664 guestport. If guestaddr is not specified, its value is x.x.x.15 2665 (default first address given by the built-in DHCP server). By 2666 specifying hostaddr, the rule can be bound to a specific host 2667 interface. If no connection type is set, TCP is used. This 2668 option can be given multiple times. 2669 2670 For example, to redirect host X11 connection from screen 1 to 2671 guest screen 0, use the following: 2672 2673 .. parsed-literal:: 2674 2675 # on the host 2676 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2677 # this host xterm should open in the guest X11 server 2678 xterm -display :1 2679 2680 To redirect telnet connections from host port 5555 to telnet 2681 port on the guest, use the following: 2682 2683 .. parsed-literal:: 2684 2685 # on the host 2686 |qemu_system| -nic user,hostfwd=tcp::5555-:23 2687 telnet localhost 5555 2688 2689 Then when you use on the host ``telnet localhost 5555``, you 2690 connect to the guest telnet server. 2691 2692 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command`` 2693 Forward guest TCP connections to the IP address server on port 2694 port to the character device dev or to a program executed by 2695 cmd:command which gets spawned for each connection. This option 2696 can be given multiple times. 2697 2698 You can either use a chardev directly and have that one used 2699 throughout QEMU's lifetime, like in the following example: 2700 2701 .. parsed-literal:: 2702 2703 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2704 # the guest accesses it 2705 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2706 2707 Or you can execute a command on every TCP connection established 2708 by the guest, so that QEMU behaves similar to an inetd process 2709 for that virtual server: 2710 2711 .. parsed-literal:: 2712 2713 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2714 # and connect the TCP stream to its stdin/stdout 2715 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2716 2717``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` 2718 Configure a host TAP network backend with ID id. 2719 2720 Use the network script file to configure it and the network script 2721 dfile to deconfigure it. If name is not provided, the OS 2722 automatically provides one. The default network configure script is 2723 ``/etc/qemu-ifup`` and the default network deconfigure script is 2724 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to 2725 disable script execution. 2726 2727 If running QEMU as an unprivileged user, use the network helper 2728 to configure the TAP interface and attach it to the bridge. 2729 The default network helper executable is 2730 ``/path/to/qemu-bridge-helper`` and the default bridge device is 2731 ``br0``. 2732 2733 ``fd``\ =h can be used to specify the handle of an already opened 2734 host TAP interface. 2735 2736 Examples: 2737 2738 .. parsed-literal:: 2739 2740 #launch a QEMU instance with the default network script 2741 |qemu_system| linux.img -nic tap 2742 2743 .. parsed-literal:: 2744 2745 #launch a QEMU instance with two NICs, each one connected 2746 #to a TAP device 2747 |qemu_system| linux.img \\ 2748 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\ 2749 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2750 2751 .. parsed-literal:: 2752 2753 #launch a QEMU instance with the default network helper to 2754 #connect a TAP device to bridge br0 2755 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 2756 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2757 2758``-netdev bridge,id=id[,br=bridge][,helper=helper]`` 2759 Connect a host TAP network interface to a host bridge device. 2760 2761 Use the network helper helper to configure the TAP interface and 2762 attach it to the bridge. The default network helper executable is 2763 ``/path/to/qemu-bridge-helper`` and the default bridge device is 2764 ``br0``. 2765 2766 Examples: 2767 2768 .. parsed-literal:: 2769 2770 #launch a QEMU instance with the default network helper to 2771 #connect a TAP device to bridge br0 2772 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2773 2774 .. parsed-literal:: 2775 2776 #launch a QEMU instance with the default network helper to 2777 #connect a TAP device to bridge qemubr0 2778 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2779 2780``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]`` 2781 This host network backend can be used to connect the guest's network 2782 to another QEMU virtual machine using a TCP socket connection. If 2783 ``listen`` is specified, QEMU waits for incoming connections on port 2784 (host is optional). ``connect`` is used to connect to another QEMU 2785 instance using the ``listen`` option. ``fd``\ =h specifies an 2786 already opened TCP socket. 2787 2788 Example: 2789 2790 .. parsed-literal:: 2791 2792 # launch a first QEMU instance 2793 |qemu_system| linux.img \\ 2794 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 2795 -netdev socket,id=n1,listen=:1234 2796 # connect the network of this instance to the network of the first instance 2797 |qemu_system| linux.img \\ 2798 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 2799 -netdev socket,id=n2,connect=127.0.0.1:1234 2800 2801``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]`` 2802 Configure a socket host network backend to share the guest's network 2803 traffic with another QEMU virtual machines using a UDP multicast 2804 socket, effectively making a bus for every QEMU with same multicast 2805 address maddr and port. NOTES: 2806 2807 1. Several QEMU can be running on different hosts and share same bus 2808 (assuming correct multicast setup for these hosts). 2809 2810 2. mcast support is compatible with User Mode Linux (argument 2811 ``ethN=mcast``), see http://user-mode-linux.sf.net. 2812 2813 3. Use ``fd=h`` to specify an already opened UDP multicast socket. 2814 2815 Example: 2816 2817 .. parsed-literal:: 2818 2819 # launch one QEMU instance 2820 |qemu_system| linux.img \\ 2821 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 2822 -netdev socket,id=n1,mcast=230.0.0.1:1234 2823 # launch another QEMU instance on same "bus" 2824 |qemu_system| linux.img \\ 2825 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 2826 -netdev socket,id=n2,mcast=230.0.0.1:1234 2827 # launch yet another QEMU instance on same "bus" 2828 |qemu_system| linux.img \\ 2829 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\ 2830 -netdev socket,id=n3,mcast=230.0.0.1:1234 2831 2832 Example (User Mode Linux compat.): 2833 2834 .. parsed-literal:: 2835 2836 # launch QEMU instance (note mcast address selected is UML's default) 2837 |qemu_system| linux.img \\ 2838 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 2839 -netdev socket,id=n1,mcast=239.192.168.1:1102 2840 # launch UML 2841 /path/to/linux ubd0=/path/to/root_fs eth0=mcast 2842 2843 Example (send packets from host's 1.2.3.4): 2844 2845 .. parsed-literal:: 2846 2847 |qemu_system| linux.img \\ 2848 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 2849 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2850 2851``-netdev l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]`` 2852 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931) 2853 is a popular protocol to transport Ethernet (and other Layer 2) data 2854 frames between two systems. It is present in routers, firewalls and 2855 the Linux kernel (from version 3.3 onwards). 2856 2857 This transport allows a VM to communicate to another VM, router or 2858 firewall directly. 2859 2860 ``src=srcaddr`` 2861 source address (mandatory) 2862 2863 ``dst=dstaddr`` 2864 destination address (mandatory) 2865 2866 ``udp`` 2867 select udp encapsulation (default is ip). 2868 2869 ``srcport=srcport`` 2870 source udp port. 2871 2872 ``dstport=dstport`` 2873 destination udp port. 2874 2875 ``ipv6`` 2876 force v6, otherwise defaults to v4. 2877 2878 ``rxcookie=rxcookie``; \ ``txcookie=txcookie`` 2879 Cookies are a weak form of security in the l2tpv3 specification. 2880 Their function is mostly to prevent misconfiguration. By default 2881 they are 32 bit. 2882 2883 ``cookie64`` 2884 Set cookie size to 64 bit instead of the default 32 2885 2886 ``counter=off`` 2887 Force a 'cut-down' L2TPv3 with no counter as in 2888 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2889 2890 ``pincounter=on`` 2891 Work around broken counter handling in peer. This may also help 2892 on networks which have packet reorder. 2893 2894 ``offset=offset`` 2895 Add an extra offset between header and data 2896 2897 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to 2898 the bridge br-lan on the remote Linux host 1.2.3.4: 2899 2900 .. parsed-literal:: 2901 2902 # Setup tunnel on linux host using raw ip as encapsulation 2903 # on 1.2.3.4 2904 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\ 2905 encap udp udp_sport 16384 udp_dport 16384 2906 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\ 2907 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2908 ifconfig vmtunnel0 mtu 1500 2909 ifconfig vmtunnel0 up 2910 brctl addif br-lan vmtunnel0 2911 2912 2913 # on 4.3.2.1 2914 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2915 2916 |qemu_system| linux.img -device e1000,netdev=n1 \\ 2917 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2918 2919``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]`` 2920 Configure VDE backend to connect to PORT n of a vde switch running 2921 on host and listening for incoming connections on socketpath. Use 2922 GROUP groupname and MODE octalmode to change default ownership and 2923 permissions for communication port. This option is only available if 2924 QEMU has been compiled with vde support enabled. 2925 2926 Example: 2927 2928 .. parsed-literal:: 2929 2930 # launch vde switch 2931 vde_switch -F -sock /tmp/myswitch 2932 # launch QEMU instance 2933 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch 2934 2935``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` 2936 Establish a vhost-user netdev, backed by a chardev id. The chardev 2937 should be a unix domain socket backed one. The vhost-user uses a 2938 specifically defined protocol to pass vhost ioctl replacement 2939 messages to an application on the other end of the socket. On 2940 non-MSIX guests, the feature can be forced with vhostforce. Use 2941 'queues=n' to specify the number of queues to be created for 2942 multiqueue vhost-user. 2943 2944 Example: 2945 2946 :: 2947 2948 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2949 -numa node,memdev=mem \ 2950 -chardev socket,id=chr0,path=/path/to/socket \ 2951 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2952 -device virtio-net-pci,netdev=net0 2953 2954``-netdev vhost-vdpa,vhostdev=/path/to/dev`` 2955 Establish a vhost-vdpa netdev. 2956 2957 vDPA device is a device that uses a datapath which complies with 2958 the virtio specifications with a vendor specific control path. 2959 vDPA devices can be both physically located on the hardware or 2960 emulated by software. 2961 2962``-netdev hubport,id=id,hubid=hubid[,netdev=nd]`` 2963 Create a hub port on the emulated hub with ID hubid. 2964 2965 The hubport netdev lets you connect a NIC to a QEMU emulated hub 2966 instead of a single netdev. Alternatively, you can also connect the 2967 hubport to another netdev with ID nd by using the ``netdev=nd`` 2968 option. 2969 2970``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]`` 2971 Legacy option to configure or create an on-board (or machine 2972 default) Network Interface Card(NIC) and connect it either to the 2973 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd. 2974 If model is omitted, then the default NIC model associated with the 2975 machine type is used. Note that the default NIC model may change in 2976 future QEMU releases, so it is highly recommended to always specify 2977 a model. Optionally, the MAC address can be changed to mac, the 2978 device address set to addr (PCI cards only), and a name can be 2979 assigned for use in monitor commands. Optionally, for PCI cards, you 2980 can specify the number v of MSI-X vectors that the card should have; 2981 this option currently only affects virtio cards; set v = 0 to 2982 disable MSI-X. If no ``-net`` option is specified, a single NIC is 2983 created. QEMU can emulate several different models of network card. 2984 Use ``-net nic,model=help`` for a list of available devices for your 2985 target. 2986 2987``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]`` 2988 Configure a host network backend (with the options corresponding to 2989 the same ``-netdev`` option) and connect it to the emulated hub 0 2990 (the default hub). Use name to specify the name of the hub port. 2991ERST 2992 2993DEFHEADING() 2994 2995DEFHEADING(Character device options:) 2996 2997DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2998 "-chardev help\n" 2999 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3000 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 3001 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 3002 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 3003 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 3004 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" 3005 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 3006 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 3007 " [,logfile=PATH][,logappend=on|off]\n" 3008 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3009 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 3010 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3011 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 3012 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3013 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3014#ifdef _WIN32 3015 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3016 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3017#else 3018 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3019 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 3020#endif 3021#ifdef CONFIG_BRLAPI 3022 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3023#endif 3024#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 3025 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 3026 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3027 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3028#endif 3029#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 3030 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3031 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3032#endif 3033#if defined(CONFIG_SPICE) 3034 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3035 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3036#endif 3037 , QEMU_ARCH_ALL 3038) 3039 3040SRST 3041The general form of a character device option is: 3042 3043``-chardev backend,id=id[,mux=on|off][,options]`` 3044 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, 3045 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, 3046 ``pty``, ``stdio``, ``braille``, ``tty``, ``parallel``, ``parport``, 3047 ``spicevmc``, ``spiceport``. The specific backend will determine the 3048 applicable options. 3049 3050 Use ``-chardev help`` to print all available chardev backend types. 3051 3052 All devices must have an id, which can be any string up to 127 3053 characters long. It is used to uniquely identify this device in 3054 other command line directives. 3055 3056 A character device may be used in multiplexing mode by multiple 3057 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is 3058 a "1:N" device, and here the "1" end is your specified chardev 3059 backend, and the "N" end is the various parts of QEMU that can talk 3060 to a chardev. If you create a chardev with ``id=myid`` and 3061 ``mux=on``, QEMU will create a multiplexer with your specified ID, 3062 and you can then configure multiple front ends to use that chardev 3063 ID for their input/output. Up to four different front ends can be 3064 connected to a single multiplexed chardev. (Without multiplexing 3065 enabled, a chardev can only be used by a single front end.) For 3066 instance you could use this to allow a single stdio chardev to be 3067 used by two serial ports and the QEMU monitor: 3068 3069 :: 3070 3071 -chardev stdio,mux=on,id=char0 \ 3072 -mon chardev=char0,mode=readline \ 3073 -serial chardev:char0 \ 3074 -serial chardev:char0 3075 3076 You can have more than one multiplexer in a system configuration; 3077 for instance you could have a TCP port multiplexed between UART 0 3078 and UART 1, and stdio multiplexed between the QEMU monitor and a 3079 parallel port: 3080 3081 :: 3082 3083 -chardev stdio,mux=on,id=char0 \ 3084 -mon chardev=char0,mode=readline \ 3085 -parallel chardev:char0 \ 3086 -chardev tcp,...,mux=on,id=char1 \ 3087 -serial chardev:char1 \ 3088 -serial chardev:char1 3089 3090 When you're using a multiplexed character device, some escape 3091 sequences are interpreted in the input. See :ref:`mux_005fkeys`. 3092 3093 Note that some other command line options may implicitly create 3094 multiplexed character backends; for instance ``-serial mon:stdio`` 3095 creates a multiplexed stdio backend connected to the serial port and 3096 the QEMU monitor, and ``-nographic`` also multiplexes the console 3097 and the monitor to stdio. 3098 3099 There is currently no support for multiplexing in the other 3100 direction (where a single QEMU front end takes input and output from 3101 multiple chardevs). 3102 3103 Every backend supports the ``logfile`` option, which supplies the 3104 path to a file to record all data transmitted via the backend. The 3105 ``logappend`` option controls whether the log file will be truncated 3106 or appended to when opened. 3107 3108The available backends are: 3109 3110``-chardev null,id=id`` 3111 A void device. This device will not emit any data, and will drop any 3112 data it receives. The null backend does not take any options. 3113 3114``-chardev socket,id=id[,TCP options or unix options][,server][,nowait][,telnet][,websocket][,reconnect=seconds][,tls-creds=id][,tls-authz=id]`` 3115 Create a two-way stream socket, which can be either a TCP or a unix 3116 socket. A unix socket will be created if ``path`` is specified. 3117 Behaviour is undefined if TCP options are specified for a unix 3118 socket. 3119 3120 ``server`` specifies that the socket shall be a listening socket. 3121 3122 ``nowait`` specifies that QEMU should not block waiting for a client 3123 to connect to a listening socket. 3124 3125 ``telnet`` specifies that traffic on the socket should interpret 3126 telnet escape sequences. 3127 3128 ``websocket`` specifies that the socket uses WebSocket protocol for 3129 communication. 3130 3131 ``reconnect`` sets the timeout for reconnecting on non-server 3132 sockets when the remote end goes away. qemu will delay this many 3133 seconds and then attempt to reconnect. Zero disables reconnecting, 3134 and is the default. 3135 3136 ``tls-creds`` requests enablement of the TLS protocol for 3137 encryption, and specifies the id of the TLS credentials to use for 3138 the handshake. The credentials must be previously created with the 3139 ``-object tls-creds`` argument. 3140 3141 ``tls-auth`` provides the ID of the QAuthZ authorization object 3142 against which the client's x509 distinguished name will be 3143 validated. This object is only resolved at time of use, so can be 3144 deleted and recreated on the fly while the chardev server is active. 3145 If missing, it will default to denying access. 3146 3147 TCP and unix socket options are given below: 3148 3149 ``TCP options: port=port[,host=host][,to=to][,ipv4][,ipv6][,nodelay]`` 3150 ``host`` for a listening socket specifies the local address to 3151 be bound. For a connecting socket species the remote host to 3152 connect to. ``host`` is optional for listening sockets. If not 3153 specified it defaults to ``0.0.0.0``. 3154 3155 ``port`` for a listening socket specifies the local port to be 3156 bound. For a connecting socket specifies the port on the remote 3157 host to connect to. ``port`` can be given as either a port 3158 number or a service name. ``port`` is required. 3159 3160 ``to`` is only relevant to listening sockets. If it is 3161 specified, and ``port`` cannot be bound, QEMU will attempt to 3162 bind to subsequent ports up to and including ``to`` until it 3163 succeeds. ``to`` must be specified as a port number. 3164 3165 ``ipv4`` and ``ipv6`` specify that either IPv4 or IPv6 must be 3166 used. If neither is specified the socket may use either 3167 protocol. 3168 3169 ``nodelay`` disables the Nagle algorithm. 3170 3171 ``unix options: path=path[,abstract=on|off][,tight=on|off]`` 3172 ``path`` specifies the local path of the unix socket. ``path`` 3173 is required. 3174 ``abstract`` specifies the use of the abstract socket namespace, 3175 rather than the filesystem. Optional, defaults to false. 3176 ``tight`` sets the socket length of abstract sockets to their minimum, 3177 rather than the full sun_path length. Optional, defaults to true. 3178 3179``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4][,ipv6]`` 3180 Sends all traffic from the guest to a remote host over UDP. 3181 3182 ``host`` specifies the remote host to connect to. If not specified 3183 it defaults to ``localhost``. 3184 3185 ``port`` specifies the port on the remote host to connect to. 3186 ``port`` is required. 3187 3188 ``localaddr`` specifies the local address to bind to. If not 3189 specified it defaults to ``0.0.0.0``. 3190 3191 ``localport`` specifies the local port to bind to. If not specified 3192 any available local port will be used. 3193 3194 ``ipv4`` and ``ipv6`` specify that either IPv4 or IPv6 must be used. 3195 If neither is specified the device may use either protocol. 3196 3197``-chardev msmouse,id=id`` 3198 Forward QEMU's emulated msmouse events to the guest. ``msmouse`` 3199 does not take any options. 3200 3201``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` 3202 Connect to a QEMU text console. ``vc`` may optionally be given a 3203 specific size. 3204 3205 ``width`` and ``height`` specify the width and height respectively 3206 of the console, in pixels. 3207 3208 ``cols`` and ``rows`` specify that the console be sized to fit a 3209 text console with the given dimensions. 3210 3211``-chardev ringbuf,id=id[,size=size]`` 3212 Create a ring buffer with fixed size ``size``. size must be a power 3213 of two and defaults to ``64K``. 3214 3215``-chardev file,id=id,path=path`` 3216 Log all traffic received from the guest to a file. 3217 3218 ``path`` specifies the path of the file to be opened. This file will 3219 be created if it does not already exist, and overwritten if it does. 3220 ``path`` is required. 3221 3222``-chardev pipe,id=id,path=path`` 3223 Create a two-way connection to the guest. The behaviour differs 3224 slightly between Windows hosts and other hosts: 3225 3226 On Windows, a single duplex pipe will be created at 3227 ``\\.pipe\path``. 3228 3229 On other hosts, 2 pipes will be created called ``path.in`` and 3230 ``path.out``. Data written to ``path.in`` will be received by the 3231 guest. Data written by the guest can be read from ``path.out``. QEMU 3232 will not create these fifos, and requires them to be present. 3233 3234 ``path`` forms part of the pipe path as described above. ``path`` is 3235 required. 3236 3237``-chardev console,id=id`` 3238 Send traffic from the guest to QEMU's standard output. ``console`` 3239 does not take any options. 3240 3241 ``console`` is only available on Windows hosts. 3242 3243``-chardev serial,id=id,path=path`` 3244 Send traffic from the guest to a serial device on the host. 3245 3246 On Unix hosts serial will actually accept any tty device, not only 3247 serial lines. 3248 3249 ``path`` specifies the name of the serial device to open. 3250 3251``-chardev pty,id=id`` 3252 Create a new pseudo-terminal on the host and connect to it. ``pty`` 3253 does not take any options. 3254 3255 ``pty`` is not available on Windows hosts. 3256 3257``-chardev stdio,id=id[,signal=on|off]`` 3258 Connect to standard input and standard output of the QEMU process. 3259 3260 ``signal`` controls if signals are enabled on the terminal, that 3261 includes exiting QEMU with the key sequence Control-c. This option 3262 is enabled by default, use ``signal=off`` to disable it. 3263 3264``-chardev braille,id=id`` 3265 Connect to a local BrlAPI server. ``braille`` does not take any 3266 options. 3267 3268``-chardev tty,id=id,path=path`` 3269 ``tty`` is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD 3270 and DragonFlyBSD hosts. It is an alias for ``serial``. 3271 3272 ``path`` specifies the path to the tty. ``path`` is required. 3273 3274``-chardev parallel,id=id,path=path`` 3275 \ 3276``-chardev parport,id=id,path=path`` 3277 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD 3278 hosts. 3279 3280 Connect to a local parallel port. 3281 3282 ``path`` specifies the path to the parallel port device. ``path`` is 3283 required. 3284 3285``-chardev spicevmc,id=id,debug=debug,name=name`` 3286 ``spicevmc`` is only available when spice support is built in. 3287 3288 ``debug`` debug level for spicevmc 3289 3290 ``name`` name of spice channel to connect to 3291 3292 Connect to a spice virtual machine channel, such as vdiport. 3293 3294``-chardev spiceport,id=id,debug=debug,name=name`` 3295 ``spiceport`` is only available when spice support is built in. 3296 3297 ``debug`` debug level for spicevmc 3298 3299 ``name`` name of spice port to connect to 3300 3301 Connect to a spice port, allowing a Spice client to handle the 3302 traffic identified by a name (preferably a fqdn). 3303ERST 3304 3305DEFHEADING() 3306 3307#ifdef CONFIG_TPM 3308DEFHEADING(TPM device options:) 3309 3310DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3311 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3312 " use path to provide path to a character device; default is /dev/tpm0\n" 3313 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3314 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3315 "-tpmdev emulator,id=id,chardev=dev\n" 3316 " configure the TPM device using chardev backend\n", 3317 QEMU_ARCH_ALL) 3318SRST 3319The general form of a TPM device option is: 3320 3321``-tpmdev backend,id=id[,options]`` 3322 The specific backend type will determine the applicable options. The 3323 ``-tpmdev`` option creates the TPM backend and requires a 3324 ``-device`` option that specifies the TPM frontend interface model. 3325 3326 Use ``-tpmdev help`` to print all available TPM backend types. 3327 3328The available backends are: 3329 3330``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path`` 3331 (Linux-host only) Enable access to the host's TPM using the 3332 passthrough driver. 3333 3334 ``path`` specifies the path to the host's TPM device, i.e., on a 3335 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by 3336 default ``/dev/tpm0`` is used. 3337 3338 ``cancel-path`` specifies the path to the host TPM device's sysfs 3339 entry allowing for cancellation of an ongoing TPM command. 3340 ``cancel-path`` is optional and by default QEMU will search for the 3341 sysfs entry to use. 3342 3343 Some notes about using the host's TPM with the passthrough driver: 3344 3345 The TPM device accessed by the passthrough driver must not be used 3346 by any other application on the host. 3347 3348 Since the host's firmware (BIOS/UEFI) has already initialized the 3349 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize 3350 the TPM again and may therefore not show a TPM-specific menu that 3351 would otherwise allow the user to configure the TPM, e.g., allow the 3352 user to enable/disable or activate/deactivate the TPM. Further, if 3353 TPM ownership is released from within a VM then the host's TPM will 3354 get disabled and deactivated. To enable and activate the TPM again 3355 afterwards, the host has to be rebooted and the user is required to 3356 enter the firmware's menu to enable and activate the TPM. If the TPM 3357 is left disabled and/or deactivated most TPM commands will fail. 3358 3359 To create a passthrough TPM use the following two options: 3360 3361 :: 3362 3363 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3364 3365 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by 3366 ``tpmdev=tpm0`` in the device option. 3367 3368``-tpmdev emulator,id=id,chardev=dev`` 3369 (Linux-host only) Enable access to a TPM emulator using Unix domain 3370 socket based chardev backend. 3371 3372 ``chardev`` specifies the unique ID of a character device backend 3373 that provides connection to the software TPM server. 3374 3375 To create a TPM emulator backend device with chardev socket backend: 3376 3377 :: 3378 3379 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3380ERST 3381 3382DEFHEADING() 3383 3384#endif 3385 3386DEFHEADING(Linux/Multiboot boot specific:) 3387SRST 3388When using these options, you can use a given Linux or Multiboot kernel 3389without installing it in the disk image. It can be useful for easier 3390testing of various kernels. 3391 3392 3393ERST 3394 3395DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3396 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3397SRST 3398``-kernel bzImage`` 3399 Use bzImage as kernel image. The kernel can be either a Linux kernel 3400 or in multiboot format. 3401ERST 3402 3403DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3404 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3405SRST 3406``-append cmdline`` 3407 Use cmdline as kernel command line 3408ERST 3409 3410DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3411 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3412SRST 3413``-initrd file`` 3414 Use file as initial ram disk. 3415 3416``-initrd "file1 arg=foo,file2"`` 3417 This syntax is only available with multiboot. 3418 3419 Use file1 and file2 as modules and pass arg=foo as parameter to the 3420 first module. 3421ERST 3422 3423DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3424 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3425SRST 3426``-dtb file`` 3427 Use file as a device tree binary (dtb) image and pass it to the 3428 kernel on boot. 3429ERST 3430 3431DEFHEADING() 3432 3433DEFHEADING(Debug/Expert options:) 3434 3435DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3436 "-fw_cfg [name=]<name>,file=<file>\n" 3437 " add named fw_cfg entry with contents from file\n" 3438 "-fw_cfg [name=]<name>,string=<str>\n" 3439 " add named fw_cfg entry with contents from string\n", 3440 QEMU_ARCH_ALL) 3441SRST 3442``-fw_cfg [name=]name,file=file`` 3443 Add named fw\_cfg entry with contents from file file. 3444 3445``-fw_cfg [name=]name,string=str`` 3446 Add named fw\_cfg entry with contents from string str. 3447 3448 The terminating NUL character of the contents of str will not be 3449 included as part of the fw\_cfg item data. To insert contents with 3450 embedded NUL characters, you have to use the file parameter. 3451 3452 The fw\_cfg entries are passed by QEMU through to the guest. 3453 3454 Example: 3455 3456 :: 3457 3458 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3459 3460 creates an fw\_cfg entry named opt/com.mycompany/blob with contents 3461 from ./my\_blob.bin. 3462ERST 3463 3464DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3465 "-serial dev redirect the serial port to char device 'dev'\n", 3466 QEMU_ARCH_ALL) 3467SRST 3468``-serial dev`` 3469 Redirect the virtual serial port to host character device dev. The 3470 default device is ``vc`` in graphical mode and ``stdio`` in non 3471 graphical mode. 3472 3473 This option can be used several times to simulate up to 4 serial 3474 ports. 3475 3476 Use ``-serial none`` to disable all serial ports. 3477 3478 Available character devices are: 3479 3480 ``vc[:WxH]`` 3481 Virtual console. Optionally, a width and height can be given in 3482 pixel with 3483 3484 :: 3485 3486 vc:800x600 3487 3488 It is also possible to specify width or height in characters: 3489 3490 :: 3491 3492 vc:80Cx24C 3493 3494 ``pty`` 3495 [Linux only] Pseudo TTY (a new PTY is automatically allocated) 3496 3497 ``none`` 3498 No device is allocated. 3499 3500 ``null`` 3501 void device 3502 3503 ``chardev:id`` 3504 Use a named character device defined with the ``-chardev`` 3505 option. 3506 3507 ``/dev/XXX`` 3508 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial 3509 port parameters are set according to the emulated ones. 3510 3511 ``/dev/parportN`` 3512 [Linux only, parallel port only] Use host parallel port N. 3513 Currently SPP and EPP parallel port features can be used. 3514 3515 ``file:filename`` 3516 Write output to filename. No character can be read. 3517 3518 ``stdio`` 3519 [Unix only] standard input/output 3520 3521 ``pipe:filename`` 3522 name pipe filename 3523 3524 ``COMn`` 3525 [Windows only] Use host serial port n 3526 3527 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]`` 3528 This implements UDP Net Console. When remote\_host or src\_ip 3529 are not specified they default to ``0.0.0.0``. When not using a 3530 specified src\_port a random port is automatically chosen. 3531 3532 If you just want a simple readonly console you can use 3533 ``netcat`` or ``nc``, by starting QEMU with: 3534 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time 3535 QEMU writes something to that port it will appear in the 3536 netconsole session. 3537 3538 If you plan to send characters back via netconsole or you want 3539 to stop and start QEMU a lot of times, you should have QEMU use 3540 the same source port each time by using something like ``-serial 3541 udp::4555@:4556`` to QEMU. Another approach is to use a patched 3542 version of netcat which can listen to a TCP port and send and 3543 receive characters via udp. If you have a patched version of 3544 netcat which activates telnet remote echo and single char 3545 transfer, then you can use the following options to set up a 3546 netcat redirector to allow telnet on port 5555 to access the 3547 QEMU port. 3548 3549 ``QEMU Options:`` 3550 -serial udp::4555@:4556 3551 3552 ``netcat options:`` 3553 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3554 3555 ``telnet options:`` 3556 localhost 5555 3557 3558 ``tcp:[host]:port[,server][,nowait][,nodelay][,reconnect=seconds]`` 3559 The TCP Net Console has two modes of operation. It can send the 3560 serial I/O to a location or wait for a connection from a 3561 location. By default the TCP Net Console is sent to host at the 3562 port. If you use the server option QEMU will wait for a client 3563 socket application to connect to the port before continuing, 3564 unless the ``nowait`` option was specified. The ``nodelay`` 3565 option disables the Nagle buffering algorithm. The ``reconnect`` 3566 option only applies if noserver is set, if the connection goes 3567 down it will attempt to reconnect at the given interval. If host 3568 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a 3569 time is accepted. You can use ``telnet`` to connect to the 3570 corresponding character device. 3571 3572 ``Example to send tcp console to 192.168.0.2 port 4444`` 3573 -serial tcp:192.168.0.2:4444 3574 3575 ``Example to listen and wait on port 4444 for connection`` 3576 -serial tcp::4444,server 3577 3578 ``Example to not wait and listen on ip 192.168.0.100 port 4444`` 3579 -serial tcp:192.168.0.100:4444,server,nowait 3580 3581 ``telnet:host:port[,server][,nowait][,nodelay]`` 3582 The telnet protocol is used instead of raw tcp sockets. The 3583 options work the same as if you had specified ``-serial tcp``. 3584 The difference is that the port acts like a telnet server or 3585 client using telnet option negotiation. This will also allow you 3586 to send the MAGIC\_SYSRQ sequence if you use a telnet that 3587 supports sending the break sequence. Typically in unix telnet 3588 you do it with Control-] and then type "send break" followed by 3589 pressing the enter key. 3590 3591 ``websocket:host:port,server[,nowait][,nodelay]`` 3592 The WebSocket protocol is used instead of raw tcp socket. The 3593 port acts as a WebSocket server. Client mode is not supported. 3594 3595 ``unix:path[,server][,nowait][,reconnect=seconds]`` 3596 A unix domain socket is used instead of a tcp socket. The option 3597 works the same as if you had specified ``-serial tcp`` except 3598 the unix domain socket path is used for connections. 3599 3600 ``mon:dev_string`` 3601 This is a special option to allow the monitor to be multiplexed 3602 onto another serial port. The monitor is accessed with key 3603 sequence of Control-a and then pressing c. dev\_string should be 3604 any one of the serial devices specified above. An example to 3605 multiplex the monitor onto a telnet server listening on port 3606 4444 would be: 3607 3608 ``-serial mon:telnet::4444,server,nowait`` 3609 3610 When the monitor is multiplexed to stdio in this way, Ctrl+C 3611 will not terminate QEMU any more but will be passed to the guest 3612 instead. 3613 3614 ``braille`` 3615 Braille device. This will use BrlAPI to display the braille 3616 output on a real or fake device. 3617 3618 ``msmouse`` 3619 Three button serial mouse. Configure the guest to use Microsoft 3620 protocol. 3621ERST 3622 3623DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3624 "-parallel dev redirect the parallel port to char device 'dev'\n", 3625 QEMU_ARCH_ALL) 3626SRST 3627``-parallel dev`` 3628 Redirect the virtual parallel port to host device dev (same devices 3629 as the serial port). On Linux hosts, ``/dev/parportN`` can be used 3630 to use hardware devices connected on the corresponding host parallel 3631 port. 3632 3633 This option can be used several times to simulate up to 3 parallel 3634 ports. 3635 3636 Use ``-parallel none`` to disable all parallel ports. 3637ERST 3638 3639DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3640 "-monitor dev redirect the monitor to char device 'dev'\n", 3641 QEMU_ARCH_ALL) 3642SRST 3643``-monitor dev`` 3644 Redirect the monitor to host device dev (same devices as the serial 3645 port). The default device is ``vc`` in graphical mode and ``stdio`` 3646 in non graphical mode. Use ``-monitor none`` to disable the default 3647 monitor. 3648ERST 3649DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3650 "-qmp dev like -monitor but opens in 'control' mode\n", 3651 QEMU_ARCH_ALL) 3652SRST 3653``-qmp dev`` 3654 Like -monitor but opens in 'control' mode. 3655ERST 3656DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3657 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3658 QEMU_ARCH_ALL) 3659SRST 3660``-qmp-pretty dev`` 3661 Like -qmp but uses pretty JSON formatting. 3662ERST 3663 3664DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3665 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3666SRST 3667``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]`` 3668 Setup monitor on chardev name. ``pretty`` turns on JSON pretty 3669 printing easing human reading and debugging. 3670ERST 3671 3672DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3673 "-debugcon dev redirect the debug console to char device 'dev'\n", 3674 QEMU_ARCH_ALL) 3675SRST 3676``-debugcon dev`` 3677 Redirect the debug console to host device dev (same devices as the 3678 serial port). The debug console is an I/O port which is typically 3679 port 0xe9; writing to that I/O port sends output to this device. The 3680 default device is ``vc`` in graphical mode and ``stdio`` in non 3681 graphical mode. 3682ERST 3683 3684DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3685 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3686SRST 3687``-pidfile file`` 3688 Store the QEMU process PID in file. It is useful if you launch QEMU 3689 from a script. 3690ERST 3691 3692DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3693 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3694SRST 3695``-singlestep`` 3696 Run the emulation in single step mode. 3697ERST 3698 3699DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3700 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3701 QEMU_ARCH_ALL) 3702SRST 3703``--preconfig`` 3704 Pause QEMU for interactive configuration before the machine is 3705 created, which allows querying and configuring properties that will 3706 affect machine initialization. Use QMP command 'x-exit-preconfig' to 3707 exit the preconfig state and move to the next state (i.e. run guest 3708 if -S isn't used or pause the second time if -S is used). This 3709 option is experimental. 3710ERST 3711 3712DEF("S", 0, QEMU_OPTION_S, \ 3713 "-S freeze CPU at startup (use 'c' to start execution)\n", 3714 QEMU_ARCH_ALL) 3715SRST 3716``-S`` 3717 Do not start CPU at startup (you must type 'c' in the monitor). 3718ERST 3719 3720DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3721 "-realtime [mlock=on|off]\n" 3722 " run qemu with realtime features\n" 3723 " mlock=on|off controls mlock support (default: on)\n", 3724 QEMU_ARCH_ALL) 3725SRST 3726``-realtime mlock=on|off`` 3727 Run qemu with realtime features. mlocking qemu and guest memory can 3728 be enabled via ``mlock=on`` (enabled by default). 3729ERST 3730 3731DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3732 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3733 " run qemu with overcommit hints\n" 3734 " mem-lock=on|off controls memory lock support (default: off)\n" 3735 " cpu-pm=on|off controls cpu power management (default: off)\n", 3736 QEMU_ARCH_ALL) 3737SRST 3738``-overcommit mem-lock=on|off`` 3739 \ 3740``-overcommit cpu-pm=on|off`` 3741 Run qemu with hints about host resource overcommit. The default is 3742 to assume that host overcommits all resources. 3743 3744 Locking qemu and guest memory can be enabled via ``mem-lock=on`` 3745 (disabled by default). This works when host memory is not 3746 overcommitted and reduces the worst-case latency for guest. This is 3747 equivalent to ``realtime``. 3748 3749 Guest ability to manage power state of host cpus (increasing latency 3750 for other processes on the same host cpu, but decreasing latency for 3751 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This 3752 works best when host CPU is not overcommitted. When used, host 3753 estimates of CPU cycle and power utilization will be incorrect, not 3754 taking into account guest idle time. 3755ERST 3756 3757DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3758 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n" 3759 " the guest without waiting for gdb to connect; use -S too\n" 3760 " if you want it to not start execution.)\n", 3761 QEMU_ARCH_ALL) 3762SRST 3763``-gdb dev`` 3764 Accept a gdb connection on device dev (see 3765 :ref:`gdb_005fusage`). Note that this option does not pause QEMU 3766 execution -- if you want QEMU to not start the guest until you 3767 connect with gdb and issue a ``continue`` command, you will need to 3768 also pass the ``-S`` option to QEMU. 3769 3770 The most usual configuration is to listen on a local TCP socket:: 3771 3772 -gdb tcp::3117 3773 3774 but you can specify other backends; UDP, pseudo TTY, or even stdio 3775 are all reasonable use cases. For example, a stdio connection 3776 allows you to start QEMU from within gdb and establish the 3777 connection via a pipe: 3778 3779 .. parsed-literal:: 3780 3781 (gdb) target remote | exec |qemu_system| -gdb stdio ... 3782ERST 3783 3784DEF("s", 0, QEMU_OPTION_s, \ 3785 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3786 QEMU_ARCH_ALL) 3787SRST 3788``-s`` 3789 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3790 (see :ref:`gdb_005fusage`). 3791ERST 3792 3793DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3794 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3795 QEMU_ARCH_ALL) 3796SRST 3797``-d item1[,...]`` 3798 Enable logging of specified items. Use '-d help' for a list of log 3799 items. 3800ERST 3801 3802DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3803 "-D logfile output log to logfile (default stderr)\n", 3804 QEMU_ARCH_ALL) 3805SRST 3806``-D logfile`` 3807 Output log in logfile instead of to stderr 3808ERST 3809 3810DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3811 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3812 QEMU_ARCH_ALL) 3813SRST 3814``-dfilter range1[,...]`` 3815 Filter debug output to that relevant to a range of target addresses. 3816 The filter spec can be either start+size, start-size or start..end 3817 where start end and size are the addresses and sizes required. For 3818 example: 3819 3820 :: 3821 3822 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3823 3824 Will dump output for any code in the 0x1000 sized block starting at 3825 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and 3826 another 0x1000 sized block starting at 0xffffffc00005f000. 3827ERST 3828 3829DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3830 "-seed number seed the pseudo-random number generator\n", 3831 QEMU_ARCH_ALL) 3832SRST 3833``-seed number`` 3834 Force the guest to use a deterministic pseudo-random number 3835 generator, seeded with number. This does not affect crypto routines 3836 within the host. 3837ERST 3838 3839DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3840 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3841 QEMU_ARCH_ALL) 3842SRST 3843``-L path`` 3844 Set the directory for the BIOS, VGA BIOS and keymaps. 3845 3846 To list all the data directories, use ``-L help``. 3847ERST 3848 3849DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3850 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3851SRST 3852``-bios file`` 3853 Set the filename for the BIOS. 3854ERST 3855 3856DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3857 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3858SRST 3859``-enable-kvm`` 3860 Enable KVM full virtualization support. This option is only 3861 available if KVM support is enabled when compiling. 3862ERST 3863 3864DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3865 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3866DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3867 "-xen-attach attach to existing xen domain\n" 3868 " libxl will use this when starting QEMU\n", 3869 QEMU_ARCH_ALL) 3870DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3871 "-xen-domid-restrict restrict set of available xen operations\n" 3872 " to specified domain id. (Does not affect\n" 3873 " xenpv machine type).\n", 3874 QEMU_ARCH_ALL) 3875SRST 3876``-xen-domid id`` 3877 Specify xen guest domain id (XEN only). 3878 3879``-xen-attach`` 3880 Attach to existing xen domain. libxl will use this when starting 3881 QEMU (XEN only). Restrict set of available xen operations to 3882 specified domain id (XEN only). 3883ERST 3884 3885DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3886 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3887SRST 3888``-no-reboot`` 3889 Exit instead of rebooting. 3890ERST 3891 3892DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3893 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3894SRST 3895``-no-shutdown`` 3896 Don't exit QEMU on guest shutdown, but instead only stop the 3897 emulation. This allows for instance switching to monitor to commit 3898 changes to the disk image. 3899ERST 3900 3901DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3902 "-loadvm [tag|id]\n" \ 3903 " start right away with a saved state (loadvm in monitor)\n", 3904 QEMU_ARCH_ALL) 3905SRST 3906``-loadvm file`` 3907 Start right away with a saved state (``loadvm`` in monitor) 3908ERST 3909 3910#ifndef _WIN32 3911DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3912 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3913#endif 3914SRST 3915``-daemonize`` 3916 Daemonize the QEMU process after initialization. QEMU will not 3917 detach from standard IO until it is ready to receive connections on 3918 any of its devices. This option is a useful way for external 3919 programs to launch QEMU without having to cope with initialization 3920 race conditions. 3921ERST 3922 3923DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3924 "-option-rom rom load a file, rom, into the option ROM space\n", 3925 QEMU_ARCH_ALL) 3926SRST 3927``-option-rom file`` 3928 Load the contents of file as an option ROM. This option is useful to 3929 load things like EtherBoot. 3930ERST 3931 3932DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3933 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3934 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3935 QEMU_ARCH_ALL) 3936 3937SRST 3938``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]`` 3939 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at 3940 the current UTC or local time, respectively. ``localtime`` is 3941 required for correct date in MS-DOS or Windows. To start at a 3942 specific point in time, provide datetime in the format 3943 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC. 3944 3945 By default the RTC is driven by the host system time. This allows 3946 using of the RTC as accurate reference clock inside the guest, 3947 specifically if the host time is smoothly following an accurate 3948 external reference clock, e.g. via NTP. If you want to isolate the 3949 guest time from the host, you can set ``clock`` to ``rt`` instead, 3950 which provides a host monotonic clock if host support it. To even 3951 prevent the RTC from progressing during suspension, you can set 3952 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is 3953 recommended especially in icount mode in order to preserve 3954 determinism; however, note that in icount mode the speed of the 3955 virtual clock is variable and can in general differ from the host 3956 clock. 3957 3958 Enable ``driftfix`` (i386 targets only) if you experience time drift 3959 problems, specifically with Windows' ACPI HAL. This option will try 3960 to figure out how many timer interrupts were not processed by the 3961 Windows guest and will re-inject them. 3962ERST 3963 3964DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3965 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3966 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3967 " instruction, enable aligning the host and virtual clocks\n" \ 3968 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3969SRST 3970``-icount [shift=N|auto][,rr=record|replay,rrfile=filename,rrsnapshot=snapshot]`` 3971 Enable virtual instruction counter. The virtual cpu will execute one 3972 instruction every 2^N ns of virtual time. If ``auto`` is specified 3973 then the virtual cpu speed will be automatically adjusted to keep 3974 virtual time within a few seconds of real time. 3975 3976 When the virtual cpu is sleeping, the virtual time will advance at 3977 default speed unless ``sleep=on|off`` is specified. With 3978 ``sleep=on|off``, the virtual time will jump to the next timer 3979 deadline instantly whenever the virtual cpu goes to sleep mode and 3980 will not advance if no timer is enabled. This behavior give 3981 deterministic execution times from the guest point of view. 3982 3983 Note that while this option can give deterministic behavior, it does 3984 not provide cycle accurate emulation. Modern CPUs contain 3985 superscalar out of order cores with complex cache hierarchies. The 3986 number of instructions executed often has little or no correlation 3987 with actual performance. 3988 3989 ``align=on`` will activate the delay algorithm which will try to 3990 synchronise the host clock and the virtual clock. The goal is to 3991 have a guest running at the real frequency imposed by the shift 3992 option. Whenever the guest clock is behind the host clock and if 3993 ``align=on`` is specified then we print a message to the user to 3994 inform about the delay. Currently this option does not work when 3995 ``shift`` is ``auto``. Note: The sync algorithm will work for those 3996 shift values for which the guest clock runs ahead of the host clock. 3997 Typically this happens when the shift value is high (how high 3998 depends on the host machine). 3999 4000 When ``rr`` option is specified deterministic record/replay is 4001 enabled. Replay log is written into filename file in record mode and 4002 read from this file in replay mode. 4003 4004 Option rrsnapshot is used to create new vm snapshot named snapshot 4005 at the start of execution recording. In replay mode this option is 4006 used to load the initial VM state. 4007ERST 4008 4009DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 4010 "-watchdog model\n" \ 4011 " enable virtual hardware watchdog [default=none]\n", 4012 QEMU_ARCH_ALL) 4013SRST 4014``-watchdog model`` 4015 Create a virtual hardware watchdog device. Once enabled (by a guest 4016 action), the watchdog must be periodically polled by an agent inside 4017 the guest or else the guest will be restarted. Choose a model for 4018 which your guest has drivers. 4019 4020 The model is the model of hardware watchdog to emulate. Use 4021 ``-watchdog help`` to list available hardware models. Only one 4022 watchdog can be enabled for a guest. 4023 4024 The following models may be available: 4025 4026 ``ib700`` 4027 iBASE 700 is a very simple ISA watchdog with a single timer. 4028 4029 ``i6300esb`` 4030 Intel 6300ESB I/O controller hub is a much more featureful 4031 PCI-based dual-timer watchdog. 4032 4033 ``diag288`` 4034 A virtual watchdog for s390x backed by the diagnose 288 4035 hypercall (currently KVM only). 4036ERST 4037 4038DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 4039 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 4040 " action when watchdog fires [default=reset]\n", 4041 QEMU_ARCH_ALL) 4042SRST 4043``-watchdog-action action`` 4044 The action controls what QEMU will do when the watchdog timer 4045 expires. The default is ``reset`` (forcefully reset the guest). 4046 Other possible actions are: ``shutdown`` (attempt to gracefully 4047 shutdown the guest), ``poweroff`` (forcefully poweroff the guest), 4048 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the 4049 guest), ``debug`` (print a debug message and continue), or ``none`` 4050 (do nothing). 4051 4052 Note that the ``shutdown`` action requires that the guest responds 4053 to ACPI signals, which it may not be able to do in the sort of 4054 situations where the watchdog would have expired, and thus 4055 ``-watchdog-action shutdown`` is not recommended for production use. 4056 4057 Examples: 4058 4059 ``-watchdog i6300esb -watchdog-action pause``; \ ``-watchdog ib700`` 4060 4061ERST 4062 4063DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 4064 "-echr chr set terminal escape character instead of ctrl-a\n", 4065 QEMU_ARCH_ALL) 4066SRST 4067``-echr numeric_ascii_value`` 4068 Change the escape character used for switching to the monitor when 4069 using monitor and serial sharing. The default is ``0x01`` when using 4070 the ``-nographic`` option. ``0x01`` is equal to pressing 4071 ``Control-a``. You can select a different character from the ascii 4072 control keys where 1 through 26 map to Control-a through Control-z. 4073 For instance you could use the either of the following to change the 4074 escape character to Control-t. 4075 4076 ``-echr 0x14``; \ ``-echr 20`` 4077 4078ERST 4079 4080DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 4081 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 4082SRST 4083``-show-cursor`` 4084 Show cursor. 4085ERST 4086 4087DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 4088 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 4089SRST 4090``-tb-size n`` 4091 Set TCG translation block cache size. Deprecated, use 4092 '\ ``-accel tcg,tb-size=n``\ ' instead. 4093ERST 4094 4095DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4096 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 4097 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 4098 "-incoming unix:socketpath\n" \ 4099 " prepare for incoming migration, listen on\n" \ 4100 " specified protocol and socket address\n" \ 4101 "-incoming fd:fd\n" \ 4102 "-incoming exec:cmdline\n" \ 4103 " accept incoming migration on given file descriptor\n" \ 4104 " or from given external command\n" \ 4105 "-incoming defer\n" \ 4106 " wait for the URI to be specified via migrate_incoming\n", 4107 QEMU_ARCH_ALL) 4108SRST 4109``-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]`` 4110 \ 4111``-incoming rdma:host:port[,ipv4][,ipv6]`` 4112 Prepare for incoming migration, listen on a given tcp port. 4113 4114``-incoming unix:socketpath`` 4115 Prepare for incoming migration, listen on a given unix socket. 4116 4117``-incoming fd:fd`` 4118 Accept incoming migration from a given filedescriptor. 4119 4120``-incoming exec:cmdline`` 4121 Accept incoming migration as an output from specified external 4122 command. 4123 4124``-incoming defer`` 4125 Wait for the URI to be specified via migrate\_incoming. The monitor 4126 can be used to change settings (such as migration parameters) prior 4127 to issuing the migrate\_incoming to allow the migration to begin. 4128ERST 4129 4130DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4131 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4132SRST 4133``-only-migratable`` 4134 Only allow migratable devices. Devices will not be allowed to enter 4135 an unmigratable state. 4136ERST 4137 4138DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4139 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4140SRST 4141``-nodefaults`` 4142 Don't create default devices. Normally, QEMU sets the default 4143 devices like serial port, parallel port, virtual console, monitor 4144 device, VGA adapter, floppy and CD-ROM drive and others. The 4145 ``-nodefaults`` option will disable all those default devices. 4146ERST 4147 4148#ifndef _WIN32 4149DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4150 "-chroot dir chroot to dir just before starting the VM\n", 4151 QEMU_ARCH_ALL) 4152#endif 4153SRST 4154``-chroot dir`` 4155 Immediately before starting guest execution, chroot to the specified 4156 directory. Especially useful in combination with -runas. 4157ERST 4158 4159#ifndef _WIN32 4160DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4161 "-runas user change to user id user just before starting the VM\n" \ 4162 " user can be numeric uid:gid instead\n", 4163 QEMU_ARCH_ALL) 4164#endif 4165SRST 4166``-runas user`` 4167 Immediately before starting guest execution, drop root privileges, 4168 switching to the specified user. 4169ERST 4170 4171DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4172 "-prom-env variable=value\n" 4173 " set OpenBIOS nvram variables\n", 4174 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4175SRST 4176``-prom-env variable=value`` 4177 Set OpenBIOS nvram variable to given value (PPC, SPARC only). 4178 4179 :: 4180 4181 qemu-system-sparc -prom-env 'auto-boot?=false' \ 4182 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' 4183 4184 :: 4185 4186 qemu-system-ppc -prom-env 'auto-boot?=false' \ 4187 -prom-env 'boot-device=hd:2,\yaboot' \ 4188 -prom-env 'boot-args=conf=hd:2,\yaboot.conf' 4189ERST 4190DEF("semihosting", 0, QEMU_OPTION_semihosting, 4191 "-semihosting semihosting mode\n", 4192 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4193 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4194SRST 4195``-semihosting`` 4196 Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4197 4198 Note that this allows guest direct access to the host filesystem, so 4199 should only be used with a trusted guest OS. 4200 4201 See the -semihosting-config option documentation for further 4202 information about the facilities this enables. 4203ERST 4204DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4205 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4206 " semihosting configuration\n", 4207QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4208QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4209SRST 4210``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]`` 4211 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II 4212 only). 4213 4214 Note that this allows guest direct access to the host filesystem, so 4215 should only be used with a trusted guest OS. 4216 4217 On Arm this implements the standard semihosting API, version 2.0. 4218 4219 On M68K this implements the "ColdFire GDB" interface used by 4220 libgloss. 4221 4222 Xtensa semihosting provides basic file IO calls, such as 4223 open/read/write/seek/select. Tensilica baremetal libc for ISS and 4224 linux platform "sim" use this interface. 4225 4226 ``target=native|gdb|auto`` 4227 Defines where the semihosting calls will be addressed, to QEMU 4228 (``native``) or to GDB (``gdb``). The default is ``auto``, which 4229 means ``gdb`` during debug sessions and ``native`` otherwise. 4230 4231 ``chardev=str1`` 4232 Send the output to a chardev backend output for native or auto 4233 output when not in gdb 4234 4235 ``arg=str1,arg=str2,...`` 4236 Allows the user to pass input arguments, and can be used 4237 multiple times to build up a list. The old-style 4238 ``-kernel``/``-append`` method of passing a command line is 4239 still supported for backward compatibility. If both the 4240 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are 4241 specified, the former is passed to semihosting as it always 4242 takes precedence. 4243ERST 4244DEF("old-param", 0, QEMU_OPTION_old_param, 4245 "-old-param old param mode\n", QEMU_ARCH_ARM) 4246SRST 4247``-old-param`` 4248 Old param mode (ARM only). 4249ERST 4250 4251DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4252 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4253 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4254 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4255 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4256 " by the kernel, but typically no longer used by modern\n" \ 4257 " C library implementations.\n" \ 4258 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4259 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4260 " The value 'children' will deny set*uid|gid system calls for\n" \ 4261 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4262 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4263 " blacklisting *fork and execve\n" \ 4264 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4265 QEMU_ARCH_ALL) 4266SRST 4267``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]`` 4268 Enable Seccomp mode 2 system call filter. 'on' will enable syscall 4269 filtering and 'off' will disable it. The default is 'off'. 4270 4271 ``obsolete=string`` 4272 Enable Obsolete system calls 4273 4274 ``elevateprivileges=string`` 4275 Disable set\*uid\|gid system calls 4276 4277 ``spawn=string`` 4278 Disable \*fork and execve 4279 4280 ``resourcecontrol=string`` 4281 Disable process affinity and schedular priority 4282ERST 4283 4284DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4285 "-readconfig <file>\n", QEMU_ARCH_ALL) 4286SRST 4287``-readconfig file`` 4288 Read device configuration from file. This approach is useful when 4289 you want to spawn QEMU process with many command line options but 4290 you don't want to exceed the command line character limit. 4291ERST 4292DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4293 "-writeconfig <file>\n" 4294 " read/write config file\n", QEMU_ARCH_ALL) 4295SRST 4296``-writeconfig file`` 4297 Write device configuration to file. The file can be either filename 4298 to save command line and device configuration into file or dash 4299 ``-``) character to print the output to stdout. This can be later 4300 used as input file for ``-readconfig`` option. 4301ERST 4302 4303DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4304 "-no-user-config\n" 4305 " do not load default user-provided config files at startup\n", 4306 QEMU_ARCH_ALL) 4307SRST 4308``-no-user-config`` 4309 The ``-no-user-config`` option makes QEMU not load any of the 4310 user-provided config files on sysconfdir. 4311ERST 4312 4313DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4314 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4315 " specify tracing options\n", 4316 QEMU_ARCH_ALL) 4317SRST 4318``-trace [[enable=]pattern][,events=file][,file=file]`` 4319 .. include:: ../qemu-option-trace.rst.inc 4320 4321ERST 4322DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4323 "-plugin [file=]<file>[,arg=<string>]\n" 4324 " load a plugin\n", 4325 QEMU_ARCH_ALL) 4326SRST 4327``-plugin file=file[,arg=string]`` 4328 Load a plugin. 4329 4330 ``file=file`` 4331 Load the given plugin from a shared library file. 4332 4333 ``arg=string`` 4334 Argument string passed to the plugin. (Can be given multiple 4335 times.) 4336ERST 4337 4338HXCOMM Internal use 4339DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4340DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4341 4342#ifdef __linux__ 4343DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4344 "-enable-fips enable FIPS 140-2 compliance\n", 4345 QEMU_ARCH_ALL) 4346#endif 4347SRST 4348``-enable-fips`` 4349 Enable FIPS 140-2 compliance mode. 4350ERST 4351 4352HXCOMM Deprecated by -accel tcg 4353DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4354 4355DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4356 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n" 4357 " control error message format\n" 4358 " timestamp=on enables timestamps (default: off)\n" 4359 " guest-name=on enables guest name prefix but only if\n" 4360 " -name guest option is set (default: off)\n", 4361 QEMU_ARCH_ALL) 4362SRST 4363``-msg [timestamp[=on|off]][,guest-name[=on|off]]`` 4364 Control error message format. 4365 4366 ``timestamp=on|off`` 4367 Prefix messages with a timestamp. Default is off. 4368 4369 ``guest-name=on|off`` 4370 Prefix messages with guest name but only if -name guest option is set 4371 otherwise the option is ignored. Default is off. 4372ERST 4373 4374DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4375 "-dump-vmstate <file>\n" 4376 " Output vmstate information in JSON format to file.\n" 4377 " Use the scripts/vmstate-static-checker.py file to\n" 4378 " check for possible regressions in migration code\n" 4379 " by comparing two such vmstate dumps.\n", 4380 QEMU_ARCH_ALL) 4381SRST 4382``-dump-vmstate file`` 4383 Dump json-encoded vmstate information for current machine type to 4384 file in file 4385ERST 4386 4387DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4388 "-enable-sync-profile\n" 4389 " enable synchronization profiling\n", 4390 QEMU_ARCH_ALL) 4391SRST 4392``-enable-sync-profile`` 4393 Enable synchronization profiling. 4394ERST 4395 4396DEFHEADING() 4397 4398DEFHEADING(Generic object creation:) 4399 4400DEF("object", HAS_ARG, QEMU_OPTION_object, 4401 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4402 " create a new object of type TYPENAME setting properties\n" 4403 " in the order they are specified. Note that the 'id'\n" 4404 " property must be set. These objects are placed in the\n" 4405 " '/objects' path.\n", 4406 QEMU_ARCH_ALL) 4407SRST 4408``-object typename[,prop1=value1,...]`` 4409 Create a new object of type typename setting properties in the order 4410 they are specified. Note that the 'id' property must be set. These 4411 objects are placed in the '/objects' path. 4412 4413 ``-object memory-backend-file,id=id,size=size,mem-path=dir,share=on|off,discard-data=on|off,merge=on|off,dump=on|off,prealloc=on|off,host-nodes=host-nodes,policy=default|preferred|bind|interleave,align=align`` 4414 Creates a memory file backend object, which can be used to back 4415 the guest RAM with huge pages. 4416 4417 The ``id`` parameter is a unique ID that will be used to 4418 reference this memory region when configuring the ``-numa`` 4419 argument. 4420 4421 The ``size`` option provides the size of the memory region, and 4422 accepts common suffixes, eg ``500M``. 4423 4424 The ``mem-path`` provides the path to either a shared memory or 4425 huge page filesystem mount. 4426 4427 The ``share`` boolean option determines whether the memory 4428 region is marked as private to QEMU, or shared. The latter 4429 allows a co-operating external process to access the QEMU memory 4430 region. 4431 4432 The ``share`` is also required for pvrdma devices due to 4433 limitations in the RDMA API provided by Linux. 4434 4435 Setting share=on might affect the ability to configure NUMA 4436 bindings for the memory backend under some circumstances, see 4437 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel 4438 source tree for additional details. 4439 4440 Setting the ``discard-data`` boolean option to on indicates that 4441 file contents can be destroyed when QEMU exits, to avoid 4442 unnecessarily flushing data to the backing file. Note that 4443 ``discard-data`` is only an optimization, and QEMU might not 4444 discard file contents if it aborts unexpectedly or is terminated 4445 using SIGKILL. 4446 4447 The ``merge`` boolean option enables memory merge, also known as 4448 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider 4449 the pages for memory deduplication. 4450 4451 Setting the ``dump`` boolean option to off excludes the memory 4452 from core dumps. This feature is also known as MADV\_DONTDUMP. 4453 4454 The ``prealloc`` boolean option enables memory preallocation. 4455 4456 The ``host-nodes`` option binds the memory range to a list of 4457 NUMA host nodes. 4458 4459 The ``policy`` option sets the NUMA policy to one of the 4460 following values: 4461 4462 ``default`` 4463 default host policy 4464 4465 ``preferred`` 4466 prefer the given host node list for allocation 4467 4468 ``bind`` 4469 restrict memory allocation to the given host node list 4470 4471 ``interleave`` 4472 interleave memory allocations across the given host node 4473 list 4474 4475 The ``align`` option specifies the base address alignment when 4476 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg 4477 ``2M``. Some backend store specified by ``mem-path`` requires an 4478 alignment different than the default one used by QEMU, eg the 4479 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4480 such cases, users can specify the required alignment via this 4481 option. 4482 4483 The ``pmem`` option specifies whether the backing file specified 4484 by ``mem-path`` is in host persistent memory that can be 4485 accessed using the SNIA NVM programming model (e.g. Intel 4486 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary 4487 operations to guarantee the persistence of its own writes to 4488 ``mem-path`` (e.g. in vNVDIMM label emulation and live 4489 migration). Also, we will map the backend-file with MAP\_SYNC 4490 flag, which ensures the file metadata is in sync for 4491 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC 4492 requires support from both the host kernel (since Linux kernel 4493 4.15) and the filesystem of ``mem-path`` mounted with DAX 4494 option. 4495 4496 ``-object memory-backend-ram,id=id,merge=on|off,dump=on|off,share=on|off,prealloc=on|off,size=size,host-nodes=host-nodes,policy=default|preferred|bind|interleave`` 4497 Creates a memory backend object, which can be used to back the 4498 guest RAM. Memory backend objects offer more control than the 4499 ``-m`` option that is traditionally used to define guest RAM. 4500 Please refer to ``memory-backend-file`` for a description of the 4501 options. 4502 4503 ``-object memory-backend-memfd,id=id,merge=on|off,dump=on|off,share=on|off,prealloc=on|off,size=size,host-nodes=host-nodes,policy=default|preferred|bind|interleave,seal=on|off,hugetlb=on|off,hugetlbsize=size`` 4504 Creates an anonymous memory file backend object, which allows 4505 QEMU to share the memory with an external process (e.g. when 4506 using vhost-user). The memory is allocated with memfd and 4507 optional sealing. (Linux only) 4508 4509 The ``seal`` option creates a sealed-file, that will block 4510 further resizing the memory ('on' by default). 4511 4512 The ``hugetlb`` option specify the file to be created resides in 4513 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction 4514 with the ``hugetlb`` option, the ``hugetlbsize`` option specify 4515 the hugetlb page size on systems that support multiple hugetlb 4516 page sizes (it must be a power of 2 value supported by the 4517 system). 4518 4519 In some versions of Linux, the ``hugetlb`` option is 4520 incompatible with the ``seal`` option (requires at least Linux 4521 4.16). 4522 4523 Please refer to ``memory-backend-file`` for a description of the 4524 other options. 4525 4526 The ``share`` boolean option is on by default with memfd. 4527 4528 ``-object rng-builtin,id=id`` 4529 Creates a random number generator backend which obtains entropy 4530 from QEMU builtin functions. The ``id`` parameter is a unique ID 4531 that will be used to reference this entropy backend from the 4532 ``virtio-rng`` device. By default, the ``virtio-rng`` device 4533 uses this RNG backend. 4534 4535 ``-object rng-random,id=id,filename=/dev/random`` 4536 Creates a random number generator backend which obtains entropy 4537 from a device on the host. The ``id`` parameter is a unique ID 4538 that will be used to reference this entropy backend from the 4539 ``virtio-rng`` device. The ``filename`` parameter specifies 4540 which file to obtain entropy from and if omitted defaults to 4541 ``/dev/urandom``. 4542 4543 ``-object rng-egd,id=id,chardev=chardevid`` 4544 Creates a random number generator backend which obtains entropy 4545 from an external daemon running on the host. The ``id`` 4546 parameter is a unique ID that will be used to reference this 4547 entropy backend from the ``virtio-rng`` device. The ``chardev`` 4548 parameter is the unique ID of a character device backend that 4549 provides the connection to the RNG daemon. 4550 4551 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off`` 4552 Creates a TLS anonymous credentials object, which can be used to 4553 provide TLS support on network backends. The ``id`` parameter is 4554 a unique ID which network backends will use to access the 4555 credentials. The ``endpoint`` is either ``server`` or ``client`` 4556 depending on whether the QEMU network backend that uses the 4557 credentials will be acting as a client or as a server. If 4558 ``verify-peer`` is enabled (the default) then once the handshake 4559 is completed, the peer credentials will be verified, though this 4560 is a no-op for anonymous credentials. 4561 4562 The dir parameter tells QEMU where to find the credential files. 4563 For server endpoints, this directory may contain a file 4564 dh-params.pem providing diffie-hellman parameters to use for the 4565 TLS server. If the file is missing, QEMU will generate a set of 4566 DH parameters at startup. This is a computationally expensive 4567 operation that consumes random pool entropy, so it is 4568 recommended that a persistent set of parameters be generated 4569 upfront and saved. 4570 4571 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]`` 4572 Creates a TLS Pre-Shared Keys (PSK) credentials object, which 4573 can be used to provide TLS support on network backends. The 4574 ``id`` parameter is a unique ID which network backends will use 4575 to access the credentials. The ``endpoint`` is either ``server`` 4576 or ``client`` depending on whether the QEMU network backend that 4577 uses the credentials will be acting as a client or as a server. 4578 For clients only, ``username`` is the username which will be 4579 sent to the server. If omitted it defaults to "qemu". 4580 4581 The dir parameter tells QEMU where to find the keys file. It is 4582 called "dir/keys.psk" and contains "username:key" pairs. This 4583 file can most easily be created using the GnuTLS ``psktool`` 4584 program. 4585 4586 For server endpoints, dir may also contain a file dh-params.pem 4587 providing diffie-hellman parameters to use for the TLS server. 4588 If the file is missing, QEMU will generate a set of DH 4589 parameters at startup. This is a computationally expensive 4590 operation that consumes random pool entropy, so it is 4591 recommended that a persistent set of parameters be generated up 4592 front and saved. 4593 4594 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id`` 4595 Creates a TLS anonymous credentials object, which can be used to 4596 provide TLS support on network backends. The ``id`` parameter is 4597 a unique ID which network backends will use to access the 4598 credentials. The ``endpoint`` is either ``server`` or ``client`` 4599 depending on whether the QEMU network backend that uses the 4600 credentials will be acting as a client or as a server. If 4601 ``verify-peer`` is enabled (the default) then once the handshake 4602 is completed, the peer credentials will be verified. With x509 4603 certificates, this implies that the clients must be provided 4604 with valid client certificates too. 4605 4606 The dir parameter tells QEMU where to find the credential files. 4607 For server endpoints, this directory may contain a file 4608 dh-params.pem providing diffie-hellman parameters to use for the 4609 TLS server. If the file is missing, QEMU will generate a set of 4610 DH parameters at startup. This is a computationally expensive 4611 operation that consumes random pool entropy, so it is 4612 recommended that a persistent set of parameters be generated 4613 upfront and saved. 4614 4615 For x509 certificate credentials the directory will contain 4616 further files providing the x509 certificates. The certificates 4617 must be stored in PEM format, in filenames ca-cert.pem, 4618 ca-crl.pem (optional), server-cert.pem (only servers), 4619 server-key.pem (only servers), client-cert.pem (only clients), 4620 and client-key.pem (only clients). 4621 4622 For the server-key.pem and client-key.pem files which contain 4623 sensitive private keys, it is possible to use an encrypted 4624 version by providing the passwordid parameter. This provides the 4625 ID of a previously created ``secret`` object containing the 4626 password for decryption. 4627 4628 The priority parameter allows to override the global default 4629 priority used by gnutls. This can be useful if the system 4630 administrator needs to use a weaker set of crypto priorities for 4631 QEMU without potentially forcing the weakness onto all 4632 applications. Or conversely if one wants wants a stronger 4633 default for QEMU than for all other applications, they can do 4634 this through this parameter. Its format is a gnutls priority 4635 string as described at 4636 https://gnutls.org/manual/html_node/Priority-Strings.html. 4637 4638 ``-object tls-cipher-suites,id=id,priority=priority`` 4639 Creates a TLS cipher suites object, which can be used to control 4640 the TLS cipher/protocol algorithms that applications are permitted 4641 to use. 4642 4643 The ``id`` parameter is a unique ID which frontends will use to 4644 access the ordered list of permitted TLS cipher suites from the 4645 host. 4646 4647 The ``priority`` parameter allows to override the global default 4648 priority used by gnutls. This can be useful if the system 4649 administrator needs to use a weaker set of crypto priorities for 4650 QEMU without potentially forcing the weakness onto all 4651 applications. Or conversely if one wants wants a stronger 4652 default for QEMU than for all other applications, they can do 4653 this through this parameter. Its format is a gnutls priority 4654 string as described at 4655 https://gnutls.org/manual/html_node/Priority-Strings.html. 4656 4657 An example of use of this object is to control UEFI HTTPS Boot. 4658 The tls-cipher-suites object exposes the ordered list of permitted 4659 TLS cipher suites from the host side to the guest firmware, via 4660 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER 4661 objects. The firmware uses the IANA_TLS_CIPHER array for configuring 4662 guest-side TLS. 4663 4664 In the following example, the priority at which the host-side policy 4665 is retrieved is given by the ``priority`` property. 4666 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to 4667 refer to /etc/crypto-policies/back-ends/gnutls.config. 4668 4669 .. parsed-literal:: 4670 4671 # |qemu_system| \\ 4672 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\ 4673 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 4674 4675 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` 4676 Interval t can't be 0, this filter batches the packet delivery: 4677 all packets arriving in a given interval on netdev netdevid are 4678 delayed until the end of the interval. Interval is in 4679 microseconds. ``status`` is optional that indicate whether the 4680 netfilter is on (enabled) or off (disabled), the default status 4681 for netfilter will be 'on'. 4682 4683 queue all\|rx\|tx is an option that can be applied to any 4684 netfilter. 4685 4686 ``all``: the filter is attached both to the receive and the 4687 transmit queue of the netdev (default). 4688 4689 ``rx``: the filter is attached to the receive queue of the 4690 netdev, where it will receive packets sent to the netdev. 4691 4692 ``tx``: the filter is attached to the transmit queue of the 4693 netdev, where it will receive packets sent by the netdev. 4694 4695 position head\|tail\|id=<id> is an option to specify where the 4696 filter should be inserted in the filter list. It can be applied 4697 to any netfilter. 4698 4699 ``head``: the filter is inserted at the head of the filter list, 4700 before any existing filters. 4701 4702 ``tail``: the filter is inserted at the tail of the filter list, 4703 behind any existing filters (default). 4704 4705 ``id=<id>``: the filter is inserted before or behind the filter 4706 specified by <id>, see the insert option below. 4707 4708 insert behind\|before is an option to specify where to insert 4709 the new filter relative to the one specified with 4710 position=id=<id>. It can be applied to any netfilter. 4711 4712 ``before``: insert before the specified filter. 4713 4714 ``behind``: insert behind the specified filter (default). 4715 4716 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 4717 filter-mirror on netdev netdevid,mirror net packet to 4718 chardevchardevid, if it has the vnet\_hdr\_support flag, 4719 filter-mirror will mirror packet with vnet\_hdr\_len. 4720 4721 ``-object filter-redirector,id=id,netdev=netdevid,indev=chardevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 4722 filter-redirector on netdev netdevid,redirect filter's net 4723 packet to chardev chardevid,and redirect indev's packet to 4724 filter.if it has the vnet\_hdr\_support flag, filter-redirector 4725 will redirect packet with vnet\_hdr\_len. Create a 4726 filter-redirector we need to differ outdev id from indev id, id 4727 can not be the same. we can just use indev or outdev, but at 4728 least one of indev or outdev need to be specified. 4729 4730 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 4731 Filter-rewriter is a part of COLO project.It will rewrite tcp 4732 packet to secondary from primary to keep secondary tcp 4733 connection,and rewrite tcp packet to primary from secondary make 4734 tcp packet can be handled by client.if it has the 4735 vnet\_hdr\_support flag, we can parse packet with vnet header. 4736 4737 usage: colo secondary: -object 4738 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object 4739 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object 4740 filter-rewriter,id=rew0,netdev=hn0,queue=all 4741 4742 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]`` 4743 Dump the network traffic on netdev dev to the file specified by 4744 filename. At most len bytes (64k by default) per packet are 4745 stored. The file format is libpcap, so it can be analyzed with 4746 tools such as tcpdump or Wireshark. 4747 4748 ``-object colo-compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=chardevid,iothread=id[,vnet_hdr_support][,notify_dev=id][,compare_timeout=@var{ms}][,expired_scan_cycle=@var{ms}][,max_queue_size=@var{size}]`` 4749 Colo-compare gets packet from primary\_in chardevid and 4750 secondary\_in, then compare whether the payload of primary packet 4751 and secondary packet are the same. If same, it will output 4752 primary packet to out\_dev, else it will notify COLO-framework to do 4753 checkpoint and send primary packet to out\_dev. In order to 4754 improve efficiency, we need to put the task of comparison in 4755 another iothread. If it has the vnet\_hdr\_support flag, 4756 colo compare will send/recv packet with vnet\_hdr\_len. 4757 The compare\_timeout=@var{ms} determines the maximum time of the 4758 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms} 4759 is to set the period of scanning expired primary node network packets. 4760 The max\_queue\_size=@var{size} is to set the max compare queue 4761 size depend on user environment. 4762 If user want to use Xen COLO, need to add the notify\_dev to 4763 notify Xen colo-frame to do checkpoint. 4764 4765 COLO-compare must be used with the help of filter-mirror, 4766 filter-redirector and filter-rewriter. 4767 4768 :: 4769 4770 KVM COLO 4771 4772 primary: 4773 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4774 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4775 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4776 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4777 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4778 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4779 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4780 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4781 -object iothread,id=iothread1 4782 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4783 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4784 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4785 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4786 4787 secondary: 4788 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4789 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4790 -chardev socket,id=red0,host=3.3.3.3,port=9003 4791 -chardev socket,id=red1,host=3.3.3.3,port=9004 4792 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4793 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4794 4795 4796 Xen COLO 4797 4798 primary: 4799 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4800 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4801 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4802 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4803 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4804 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4805 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4806 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4807 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4808 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4809 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4810 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4811 -object iothread,id=iothread1 4812 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4813 4814 secondary: 4815 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4816 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4817 -chardev socket,id=red0,host=3.3.3.3,port=9003 4818 -chardev socket,id=red1,host=3.3.3.3,port=9004 4819 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4820 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4821 4822 If you want to know the detail of above command line, you can 4823 read the colo-compare git log. 4824 4825 ``-object cryptodev-backend-builtin,id=id[,queues=queues]`` 4826 Creates a cryptodev backend which executes crypto opreation from 4827 the QEMU cipher APIS. The id parameter is a unique ID that will 4828 be used to reference this cryptodev backend from the 4829 ``virtio-crypto`` device. The queues parameter is optional, 4830 which specify the queue number of cryptodev backend, the default 4831 of queues is 1. 4832 4833 .. parsed-literal:: 4834 4835 # |qemu_system| \\ 4836 [...] \\ 4837 -object cryptodev-backend-builtin,id=cryptodev0 \\ 4838 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 4839 [...] 4840 4841 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]`` 4842 Creates a vhost-user cryptodev backend, backed by a chardev 4843 chardevid. The id parameter is a unique ID that will be used to 4844 reference this cryptodev backend from the ``virtio-crypto`` 4845 device. The chardev should be a unix domain socket backed one. 4846 The vhost-user uses a specifically defined protocol to pass 4847 vhost ioctl replacement messages to an application on the other 4848 end of the socket. The queues parameter is optional, which 4849 specify the queue number of cryptodev backend for multiqueue 4850 vhost-user, the default of queues is 1. 4851 4852 .. parsed-literal:: 4853 4854 # |qemu_system| \\ 4855 [...] \\ 4856 -chardev socket,id=chardev0,path=/path/to/socket \\ 4857 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\ 4858 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 4859 [...] 4860 4861 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]`` 4862 \ 4863 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]`` 4864 Defines a secret to store a password, encryption key, or some 4865 other sensitive data. The sensitive data can either be passed 4866 directly via the data parameter, or indirectly via the file 4867 parameter. Using the data parameter is insecure unless the 4868 sensitive data is encrypted. 4869 4870 The sensitive data can be provided in raw format (the default), 4871 or base64. When encoded as JSON, the raw format only supports 4872 valid UTF-8 characters, so base64 is recommended for sending 4873 binary data. QEMU will convert from which ever format is 4874 provided to the format it needs internally. eg, an RBD password 4875 can be provided in raw format, even though it will be base64 4876 encoded when passed onto the RBD sever. 4877 4878 For added protection, it is possible to encrypt the data 4879 associated with a secret using the AES-256-CBC cipher. Use of 4880 encryption is indicated by providing the keyid and iv 4881 parameters. The keyid parameter provides the ID of a previously 4882 defined secret that contains the AES-256 decryption key. This 4883 key should be 32-bytes long and be base64 encoded. The iv 4884 parameter provides the random initialization vector used for 4885 encryption of this particular secret and should be a base64 4886 encrypted string of the 16-byte IV. 4887 4888 The simplest (insecure) usage is to provide the secret inline 4889 4890 .. parsed-literal:: 4891 4892 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw 4893 4894 The simplest secure usage is to provide the secret via a file 4895 4896 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object 4897 secret,id=sec0,file=mypasswd.txt,format=raw 4898 4899 For greater security, AES-256-CBC should be used. To illustrate 4900 usage, consider the openssl command line tool which can encrypt 4901 the data. Note that when encrypting, the plaintext must be 4902 padded to the cipher block size (32 bytes) using the standard 4903 PKCS#5/6 compatible padding algorithm. 4904 4905 First a master key needs to be created in base64 encoding: 4906 4907 :: 4908 4909 # openssl rand -base64 32 > key.b64 4910 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4911 4912 Each secret to be encrypted needs to have a random 4913 initialization vector generated. These do not need to be kept 4914 secret 4915 4916 :: 4917 4918 # openssl rand -base64 16 > iv.b64 4919 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4920 4921 The secret to be defined can now be encrypted, in this case 4922 we're telling openssl to base64 encode the result, but it could 4923 be left as raw bytes if desired. 4924 4925 :: 4926 4927 # SECRET=$(printf "letmein" | 4928 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4929 4930 When launching QEMU, create a master secret pointing to 4931 ``key.b64`` and specify that to be used to decrypt the user 4932 password. Pass the contents of ``iv.b64`` to the second secret 4933 4934 .. parsed-literal:: 4935 4936 # |qemu_system| \\ 4937 -object secret,id=secmaster0,format=base64,file=key.b64 \\ 4938 -object secret,id=sec0,keyid=secmaster0,format=base64,\\ 4939 data=$SECRET,iv=$(<iv.b64) 4940 4941 ``-object sev-guest,id=id,cbitpos=cbitpos,reduced-phys-bits=val,[sev-device=string,policy=policy,handle=handle,dh-cert-file=file,session-file=file]`` 4942 Create a Secure Encrypted Virtualization (SEV) guest object, 4943 which can be used to provide the guest memory encryption support 4944 on AMD processors. 4945 4946 When memory encryption is enabled, one of the physical address 4947 bit (aka the C-bit) is utilized to mark if a memory page is 4948 protected. The ``cbitpos`` is used to provide the C-bit 4949 position. The C-bit position is Host family dependent hence user 4950 must provide this value. On EPYC, the value should be 47. 4951 4952 When memory encryption is enabled, we loose certain bits in 4953 physical address space. The ``reduced-phys-bits`` is used to 4954 provide the number of bits we loose in physical address space. 4955 Similar to C-bit, the value is Host family dependent. On EPYC, 4956 the value should be 5. 4957 4958 The ``sev-device`` provides the device file to use for 4959 communicating with the SEV firmware running inside AMD Secure 4960 Processor. The default device is '/dev/sev'. If hardware 4961 supports memory encryption then /dev/sev devices are created by 4962 CCP driver. 4963 4964 The ``policy`` provides the guest policy to be enforced by the 4965 SEV firmware and restrict what configuration and operational 4966 commands can be performed on this guest by the hypervisor. The 4967 policy should be provided by the guest owner and is bound to the 4968 guest and cannot be changed throughout the lifetime of the 4969 guest. The default is 0. 4970 4971 If guest ``policy`` allows sharing the key with another SEV 4972 guest then ``handle`` can be use to provide handle of the guest 4973 from which to share the key. 4974 4975 The ``dh-cert-file`` and ``session-file`` provides the guest 4976 owner's Public Diffie-Hillman key defined in SEV spec. The PDH 4977 and session parameters are used for establishing a cryptographic 4978 session with the guest owner to negotiate keys used for 4979 attestation. The file must be encoded in base64. 4980 4981 e.g to launch a SEV guest 4982 4983 .. parsed-literal:: 4984 4985 # |qemu_system_x86| \\ 4986 ...... \\ 4987 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \\ 4988 -machine ...,memory-encryption=sev0 \\ 4989 ..... 4990 4991 ``-object authz-simple,id=id,identity=string`` 4992 Create an authorization object that will control access to 4993 network services. 4994 4995 The ``identity`` parameter is identifies the user and its format 4996 depends on the network service that authorization object is 4997 associated with. For authorizing based on TLS x509 certificates, 4998 the identity must be the x509 distinguished name. Note that care 4999 must be taken to escape any commas in the distinguished name. 5000 5001 An example authorization object to validate a x509 distinguished 5002 name would look like: 5003 5004 .. parsed-literal:: 5005 5006 # |qemu_system| \\ 5007 ... \\ 5008 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\ 5009 ... 5010 5011 Note the use of quotes due to the x509 distinguished name 5012 containing whitespace, and escaping of ','. 5013 5014 ``-object authz-listfile,id=id,filename=path,refresh=yes|no`` 5015 Create an authorization object that will control access to 5016 network services. 5017 5018 The ``filename`` parameter is the fully qualified path to a file 5019 containing the access control list rules in JSON format. 5020 5021 An example set of rules that match against SASL usernames might 5022 look like: 5023 5024 :: 5025 5026 { 5027 "rules": [ 5028 { "match": "fred", "policy": "allow", "format": "exact" }, 5029 { "match": "bob", "policy": "allow", "format": "exact" }, 5030 { "match": "danb", "policy": "deny", "format": "glob" }, 5031 { "match": "dan*", "policy": "allow", "format": "exact" }, 5032 ], 5033 "policy": "deny" 5034 } 5035 5036 When checking access the object will iterate over all the rules 5037 and the first rule to match will have its ``policy`` value 5038 returned as the result. If no rules match, then the default 5039 ``policy`` value is returned. 5040 5041 The rules can either be an exact string match, or they can use 5042 the simple UNIX glob pattern matching to allow wildcards to be 5043 used. 5044 5045 If ``refresh`` is set to true the file will be monitored and 5046 automatically reloaded whenever its content changes. 5047 5048 As with the ``authz-simple`` object, the format of the identity 5049 strings being matched depends on the network service, but is 5050 usually a TLS x509 distinguished name, or a SASL username. 5051 5052 An example authorization object to validate a SASL username 5053 would look like: 5054 5055 .. parsed-literal:: 5056 5057 # |qemu_system| \\ 5058 ... \\ 5059 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes \\ 5060 ... 5061 5062 ``-object authz-pam,id=id,service=string`` 5063 Create an authorization object that will control access to 5064 network services. 5065 5066 The ``service`` parameter provides the name of a PAM service to 5067 use for authorization. It requires that a file 5068 ``/etc/pam.d/service`` exist to provide the configuration for 5069 the ``account`` subsystem. 5070 5071 An example authorization object to validate a TLS x509 5072 distinguished name would look like: 5073 5074 .. parsed-literal:: 5075 5076 # |qemu_system| \\ 5077 ... \\ 5078 -object authz-pam,id=auth0,service=qemu-vnc \\ 5079 ... 5080 5081 There would then be a corresponding config file for PAM at 5082 ``/etc/pam.d/qemu-vnc`` that contains: 5083 5084 :: 5085 5086 account requisite pam_listfile.so item=user sense=allow \ 5087 file=/etc/qemu/vnc.allow 5088 5089 Finally the ``/etc/qemu/vnc.allow`` file would contain the list 5090 of x509 distingished names that are permitted access 5091 5092 :: 5093 5094 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 5095 5096 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink`` 5097 Creates a dedicated event loop thread that devices can be 5098 assigned to. This is known as an IOThread. By default device 5099 emulation happens in vCPU threads or the main event loop thread. 5100 This can become a scalability bottleneck. IOThreads allow device 5101 emulation and I/O to run on other host CPUs. 5102 5103 The ``id`` parameter is a unique ID that will be used to 5104 reference this IOThread from ``-device ...,iothread=id``. 5105 Multiple devices can be assigned to an IOThread. Note that not 5106 all devices support an ``iothread`` parameter. 5107 5108 The ``query-iothreads`` QMP command lists IOThreads and reports 5109 their thread IDs so that the user can configure host CPU 5110 pinning/affinity. 5111 5112 IOThreads use an adaptive polling algorithm to reduce event loop 5113 latency. Instead of entering a blocking system call to monitor 5114 file descriptors and then pay the cost of being woken up when an 5115 event occurs, the polling algorithm spins waiting for events for 5116 a short time. The algorithm's default parameters are suitable 5117 for many cases but can be adjusted based on knowledge of the 5118 workload and/or host device latency. 5119 5120 The ``poll-max-ns`` parameter is the maximum number of 5121 nanoseconds to busy wait for events. Polling can be disabled by 5122 setting this value to 0. 5123 5124 The ``poll-grow`` parameter is the multiplier used to increase 5125 the polling time when the algorithm detects it is missing events 5126 due to not polling long enough. 5127 5128 The ``poll-shrink`` parameter is the divisor used to decrease 5129 the polling time when the algorithm detects it is spending too 5130 long polling without encountering events. 5131 5132 The polling parameters can be modified at run-time using the 5133 ``qom-set`` command (where ``iothread1`` is the IOThread's 5134 ``id``): 5135 5136 :: 5137 5138 (qemu) qom-set /objects/iothread1 poll-max-ns 100000 5139ERST 5140 5141 5142HXCOMM This is the last statement. Insert new options before this line! 5143
