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/io_uring, 1057 default: threads) 1058 1059 ``locking`` 1060 Specifies whether the image file is protected with Linux OFD 1061 / POSIX locks. The default is to use the Linux Open File 1062 Descriptor API if available, otherwise no lock is applied. 1063 (auto/on/off, default: auto) 1064 1065 Example: 1066 1067 :: 1068 1069 -blockdev driver=file,node-name=disk,filename=disk.img 1070 1071 ``Driver-specific options for raw`` 1072 This is the image format block driver for raw images. It is 1073 usually stacked on top of a protocol level block driver such as 1074 ``file``. 1075 1076 ``file`` 1077 Reference to or definition of the data source block driver 1078 node (e.g. a ``file`` driver node) 1079 1080 Example 1: 1081 1082 :: 1083 1084 -blockdev driver=file,node-name=disk_file,filename=disk.img 1085 -blockdev driver=raw,node-name=disk,file=disk_file 1086 1087 Example 2: 1088 1089 :: 1090 1091 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1092 1093 ``Driver-specific options for qcow2`` 1094 This is the image format block driver for qcow2 images. It is 1095 usually stacked on top of a protocol level block driver such as 1096 ``file``. 1097 1098 ``file`` 1099 Reference to or definition of the data source block driver 1100 node (e.g. a ``file`` driver node) 1101 1102 ``backing`` 1103 Reference to or definition of the backing file block device 1104 (default is taken from the image file). It is allowed to 1105 pass ``null`` here in order to disable the default backing 1106 file. 1107 1108 ``lazy-refcounts`` 1109 Whether to enable the lazy refcounts feature (on/off; 1110 default is taken from the image file) 1111 1112 ``cache-size`` 1113 The maximum total size of the L2 table and refcount block 1114 caches in bytes (default: the sum of l2-cache-size and 1115 refcount-cache-size) 1116 1117 ``l2-cache-size`` 1118 The maximum size of the L2 table cache in bytes (default: if 1119 cache-size is not specified - 32M on Linux platforms, and 8M 1120 on non-Linux platforms; otherwise, as large as possible 1121 within the cache-size, while permitting the requested or the 1122 minimal refcount cache size) 1123 1124 ``refcount-cache-size`` 1125 The maximum size of the refcount block cache in bytes 1126 (default: 4 times the cluster size; or if cache-size is 1127 specified, the part of it which is not used for the L2 1128 cache) 1129 1130 ``cache-clean-interval`` 1131 Clean unused entries in the L2 and refcount caches. The 1132 interval is in seconds. The default value is 600 on 1133 supporting platforms, and 0 on other platforms. Setting it 1134 to 0 disables this feature. 1135 1136 ``pass-discard-request`` 1137 Whether discard requests to the qcow2 device should be 1138 forwarded to the data source (on/off; default: on if 1139 discard=unmap is specified, off otherwise) 1140 1141 ``pass-discard-snapshot`` 1142 Whether discard requests for the data source should be 1143 issued when a snapshot operation (e.g. deleting a snapshot) 1144 frees clusters in the qcow2 file (on/off; default: on) 1145 1146 ``pass-discard-other`` 1147 Whether discard requests for the data source should be 1148 issued on other occasions where a cluster gets freed 1149 (on/off; default: off) 1150 1151 ``overlap-check`` 1152 Which overlap checks to perform for writes to the image 1153 (none/constant/cached/all; default: cached). For details or 1154 finer granularity control refer to the QAPI documentation of 1155 ``blockdev-add``. 1156 1157 Example 1: 1158 1159 :: 1160 1161 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1162 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1163 1164 Example 2: 1165 1166 :: 1167 1168 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1169 1170 ``Driver-specific options for other drivers`` 1171 Please refer to the QAPI documentation of the ``blockdev-add`` 1172 QMP command. 1173ERST 1174 1175DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1176 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1177 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1178 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1179 " [,werror=ignore|stop|report|enospc][,id=name]\n" 1180 " [,aio=threads|native|io_uring]\n" 1181 " [,readonly=on|off][,copy-on-read=on|off]\n" 1182 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1183 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1184 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1185 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1186 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1187 " [[,iops_size=is]]\n" 1188 " [[,group=g]]\n" 1189 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1190SRST 1191``-drive option[,option[,option[,...]]]`` 1192 Define a new drive. This includes creating a block driver node (the 1193 backend) as well as a guest device, and is mostly a shortcut for 1194 defining the corresponding ``-blockdev`` and ``-device`` options. 1195 1196 ``-drive`` accepts all options that are accepted by ``-blockdev``. 1197 In addition, it knows the following options: 1198 1199 ``file=file`` 1200 This option defines which disk image (see 1201 :ref:`disk_005fimages`) to use with this drive. If 1202 the filename contains comma, you must double it (for instance, 1203 "file=my,,file" to use file "my,file"). 1204 1205 Special files such as iSCSI devices can be specified using 1206 protocol specific URLs. See the section for "Device URL Syntax" 1207 for more information. 1208 1209 ``if=interface`` 1210 This option defines on which type on interface the drive is 1211 connected. Available types are: ide, scsi, sd, mtd, floppy, 1212 pflash, virtio, none. 1213 1214 ``bus=bus,unit=unit`` 1215 These options define where is connected the drive by defining 1216 the bus number and the unit id. 1217 1218 ``index=index`` 1219 This option defines where is connected the drive by using an 1220 index in the list of available connectors of a given interface 1221 type. 1222 1223 ``media=media`` 1224 This option defines the type of the media: disk or cdrom. 1225 1226 ``snapshot=snapshot`` 1227 snapshot is "on" or "off" and controls snapshot mode for the 1228 given drive (see ``-snapshot``). 1229 1230 ``cache=cache`` 1231 cache is "none", "writeback", "unsafe", "directsync" or 1232 "writethrough" and controls how the host cache is used to access 1233 block data. This is a shortcut that sets the ``cache.direct`` 1234 and ``cache.no-flush`` options (as in ``-blockdev``), and 1235 additionally ``cache.writeback``, which provides a default for 1236 the ``write-cache`` option of block guest devices (as in 1237 ``-device``). The modes correspond to the following settings: 1238 1239 ============= =============== ============ ============== 1240 \ cache.writeback cache.direct cache.no-flush 1241 ============= =============== ============ ============== 1242 writeback on off off 1243 none on on off 1244 writethrough off off off 1245 directsync off on off 1246 unsafe on off on 1247 ============= =============== ============ ============== 1248 1249 The default mode is ``cache=writeback``. 1250 1251 ``aio=aio`` 1252 aio is "threads", "native", or "io_uring" and selects between pthread 1253 based disk I/O, native Linux AIO, or Linux io_uring API. 1254 1255 ``format=format`` 1256 Specify which disk format will be used rather than detecting the 1257 format. Can be used to specify format=raw to avoid interpreting 1258 an untrusted format header. 1259 1260 ``werror=action,rerror=action`` 1261 Specify which action to take on write and read errors. Valid 1262 actions are: "ignore" (ignore the error and try to continue), 1263 "stop" (pause QEMU), "report" (report the error to the guest), 1264 "enospc" (pause QEMU only if the host disk is full; report the 1265 error to the guest otherwise). The default setting is 1266 ``werror=enospc`` and ``rerror=report``. 1267 1268 ``copy-on-read=copy-on-read`` 1269 copy-on-read is "on" or "off" and enables whether to copy read 1270 backing file sectors into the image file. 1271 1272 ``bps=b,bps_rd=r,bps_wr=w`` 1273 Specify bandwidth throttling limits in bytes per second, either 1274 for all request types or for reads or writes only. Small values 1275 can lead to timeouts or hangs inside the guest. A safe minimum 1276 for disks is 2 MB/s. 1277 1278 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm`` 1279 Specify bursts in bytes per second, either for all request types 1280 or for reads or writes only. Bursts allow the guest I/O to spike 1281 above the limit temporarily. 1282 1283 ``iops=i,iops_rd=r,iops_wr=w`` 1284 Specify request rate limits in requests per second, either for 1285 all request types or for reads or writes only. 1286 1287 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm`` 1288 Specify bursts in requests per second, either for all request 1289 types or for reads or writes only. Bursts allow the guest I/O to 1290 spike above the limit temporarily. 1291 1292 ``iops_size=is`` 1293 Let every is bytes of a request count as a new request for iops 1294 throttling purposes. Use this option to prevent guests from 1295 circumventing iops limits by sending fewer but larger requests. 1296 1297 ``group=g`` 1298 Join a throttling quota group with given name g. All drives that 1299 are members of the same group are accounted for together. Use 1300 this option to prevent guests from circumventing throttling 1301 limits by using many small disks instead of a single larger 1302 disk. 1303 1304 By default, the ``cache.writeback=on`` mode is used. It will report 1305 data writes as completed as soon as the data is present in the host 1306 page cache. This is safe as long as your guest OS makes sure to 1307 correctly flush disk caches where needed. If your guest OS does not 1308 handle volatile disk write caches correctly and your host crashes or 1309 loses power, then the guest may experience data corruption. 1310 1311 For such guests, you should consider using ``cache.writeback=off``. 1312 This means that the host page cache will be used to read and write 1313 data, but write notification will be sent to the guest only after 1314 QEMU has made sure to flush each write to the disk. Be aware that 1315 this has a major impact on performance. 1316 1317 When using the ``-snapshot`` option, unsafe caching is always used. 1318 1319 Copy-on-read avoids accessing the same backing file sectors 1320 repeatedly and is useful when the backing file is over a slow 1321 network. By default copy-on-read is off. 1322 1323 Instead of ``-cdrom`` you can use: 1324 1325 .. parsed-literal:: 1326 1327 |qemu_system| -drive file=file,index=2,media=cdrom 1328 1329 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use: 1330 1331 .. parsed-literal:: 1332 1333 |qemu_system| -drive file=file,index=0,media=disk 1334 |qemu_system| -drive file=file,index=1,media=disk 1335 |qemu_system| -drive file=file,index=2,media=disk 1336 |qemu_system| -drive file=file,index=3,media=disk 1337 1338 You can open an image using pre-opened file descriptors from an fd 1339 set: 1340 1341 .. parsed-literal:: 1342 1343 |qemu_system| \\ 1344 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 1345 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 1346 -drive file=/dev/fdset/2,index=0,media=disk 1347 1348 You can connect a CDROM to the slave of ide0: 1349 1350 .. parsed-literal:: 1351 1352 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom 1353 1354 If you don't specify the "file=" argument, you define an empty 1355 drive: 1356 1357 .. parsed-literal:: 1358 1359 |qemu_system_x86| -drive if=ide,index=1,media=cdrom 1360 1361 Instead of ``-fda``, ``-fdb``, you can use: 1362 1363 .. parsed-literal:: 1364 1365 |qemu_system_x86| -drive file=file,index=0,if=floppy 1366 |qemu_system_x86| -drive file=file,index=1,if=floppy 1367 1368 By default, interface is "ide" and index is automatically 1369 incremented: 1370 1371 .. parsed-literal:: 1372 1373 |qemu_system_x86| -drive file=a -drive file=b" 1374 1375 is interpreted like: 1376 1377 .. parsed-literal:: 1378 1379 |qemu_system_x86| -hda a -hdb b 1380ERST 1381 1382DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1383 "-mtdblock file use 'file' as on-board Flash memory image\n", 1384 QEMU_ARCH_ALL) 1385SRST 1386``-mtdblock file`` 1387 Use file as on-board Flash memory image. 1388ERST 1389 1390DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1391 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1392SRST 1393``-sd file`` 1394 Use file as SecureDigital card image. 1395ERST 1396 1397DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1398 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1399SRST 1400``-pflash file`` 1401 Use file as a parallel flash image. 1402ERST 1403 1404DEF("snapshot", 0, QEMU_OPTION_snapshot, 1405 "-snapshot write to temporary files instead of disk image files\n", 1406 QEMU_ARCH_ALL) 1407SRST 1408``-snapshot`` 1409 Write to temporary files instead of disk image files. In this case, 1410 the raw disk image you use is not written back. You can however 1411 force the write back by pressing C-a s (see 1412 :ref:`disk_005fimages`). 1413ERST 1414 1415DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1416 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1417 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1418 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1419 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1420 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1421 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1422 " [[,throttling.iops-size=is]]\n" 1423 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1424 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1425 "-fsdev synth,id=id\n", 1426 QEMU_ARCH_ALL) 1427 1428SRST 1429``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]`` 1430 \ 1431``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly]`` 1432 \ 1433``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly]`` 1434 \ 1435``-fsdev synth,id=id[,readonly]`` 1436 Define a new file system device. Valid options are: 1437 1438 ``local`` 1439 Accesses to the filesystem are done by QEMU. 1440 1441 ``proxy`` 1442 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1443 1444 ``synth`` 1445 Synthetic filesystem, only used by QTests. 1446 1447 ``id=id`` 1448 Specifies identifier for this device. 1449 1450 ``path=path`` 1451 Specifies the export path for the file system device. Files 1452 under this path will be available to the 9p client on the guest. 1453 1454 ``security_model=security_model`` 1455 Specifies the security model to be used for this export path. 1456 Supported security models are "passthrough", "mapped-xattr", 1457 "mapped-file" and "none". In "passthrough" security model, files 1458 are stored using the same credentials as they are created on the 1459 guest. This requires QEMU to run as root. In "mapped-xattr" 1460 security model, some of the file attributes like uid, gid, mode 1461 bits and link target are stored as file attributes. For 1462 "mapped-file" these attributes are stored in the hidden 1463 .virtfs\_metadata directory. Directories exported by this 1464 security model cannot interact with other unix tools. "none" 1465 security model is same as passthrough except the sever won't 1466 report failures if it fails to set file attributes like 1467 ownership. Security model is mandatory only for local fsdriver. 1468 Other fsdrivers (like proxy) don't take security model as a 1469 parameter. 1470 1471 ``writeout=writeout`` 1472 This is an optional argument. The only supported value is 1473 "immediate". This means that host page cache will be used to 1474 read and write data but write notification will be sent to the 1475 guest only when the data has been reported as written by the 1476 storage subsystem. 1477 1478 ``readonly`` 1479 Enables exporting 9p share as a readonly mount for guests. By 1480 default read-write access is given. 1481 1482 ``socket=socket`` 1483 Enables proxy filesystem driver to use passed socket file for 1484 communicating with virtfs-proxy-helper(1). 1485 1486 ``sock_fd=sock_fd`` 1487 Enables proxy filesystem driver to use passed socket descriptor 1488 for communicating with virtfs-proxy-helper(1). Usually a helper 1489 like libvirt will create socketpair and pass one of the fds as 1490 sock\_fd. 1491 1492 ``fmode=fmode`` 1493 Specifies the default mode for newly created files on the host. 1494 Works only with security models "mapped-xattr" and 1495 "mapped-file". 1496 1497 ``dmode=dmode`` 1498 Specifies the default mode for newly created directories on the 1499 host. Works only with security models "mapped-xattr" and 1500 "mapped-file". 1501 1502 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w`` 1503 Specify bandwidth throttling limits in bytes per second, either 1504 for all request types or for reads or writes only. 1505 1506 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm`` 1507 Specify bursts in bytes per second, either for all request types 1508 or for reads or writes only. Bursts allow the guest I/O to spike 1509 above the limit temporarily. 1510 1511 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w`` 1512 Specify request rate limits in requests per second, either for 1513 all request types or for reads or writes only. 1514 1515 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm`` 1516 Specify bursts in requests per second, either for all request 1517 types or for reads or writes only. Bursts allow the guest I/O to 1518 spike above the limit temporarily. 1519 1520 ``throttling.iops-size=is`` 1521 Let every is bytes of a request count as a new request for iops 1522 throttling purposes. 1523 1524 -fsdev option is used along with -device driver "virtio-9p-...". 1525 1526``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag`` 1527 Options for virtio-9p-... driver are: 1528 1529 ``type`` 1530 Specifies the variant to be used. Supported values are "pci", 1531 "ccw" or "device", depending on the machine type. 1532 1533 ``fsdev=id`` 1534 Specifies the id value specified along with -fsdev option. 1535 1536 ``mount_tag=mount_tag`` 1537 Specifies the tag name to be used by the guest to mount this 1538 export point. 1539ERST 1540 1541DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1542 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1543 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1544 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1545 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1546 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1547 QEMU_ARCH_ALL) 1548 1549SRST 1550``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]`` 1551 \ 1552``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly]`` 1553 \ 1554``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly]`` 1555 \ 1556``-virtfs synth,mount_tag=mount_tag`` 1557 Define a new virtual filesystem device and expose it to the guest using 1558 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain 1559 directory on host is made directly accessible by guest as a pass-through 1560 file system by using the 9P network protocol for communication between 1561 host and guests, if desired even accessible, shared by several guests 1562 simultaniously. 1563 1564 Note that ``-virtfs`` is actually just a convenience shortcut for its 1565 generalized form ``-fsdev -device virtio-9p-pci``. 1566 1567 The general form of pass-through file system options are: 1568 1569 ``local`` 1570 Accesses to the filesystem are done by QEMU. 1571 1572 ``proxy`` 1573 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1574 1575 ``synth`` 1576 Synthetic filesystem, only used by QTests. 1577 1578 ``id=id`` 1579 Specifies identifier for the filesystem device 1580 1581 ``path=path`` 1582 Specifies the export path for the file system device. Files 1583 under this path will be available to the 9p client on the guest. 1584 1585 ``security_model=security_model`` 1586 Specifies the security model to be used for this export path. 1587 Supported security models are "passthrough", "mapped-xattr", 1588 "mapped-file" and "none". In "passthrough" security model, files 1589 are stored using the same credentials as they are created on the 1590 guest. This requires QEMU to run as root. In "mapped-xattr" 1591 security model, some of the file attributes like uid, gid, mode 1592 bits and link target are stored as file attributes. For 1593 "mapped-file" these attributes are stored in the hidden 1594 .virtfs\_metadata directory. Directories exported by this 1595 security model cannot interact with other unix tools. "none" 1596 security model is same as passthrough except the sever won't 1597 report failures if it fails to set file attributes like 1598 ownership. Security model is mandatory only for local fsdriver. 1599 Other fsdrivers (like proxy) don't take security model as a 1600 parameter. 1601 1602 ``writeout=writeout`` 1603 This is an optional argument. The only supported value is 1604 "immediate". This means that host page cache will be used to 1605 read and write data but write notification will be sent to the 1606 guest only when the data has been reported as written by the 1607 storage subsystem. 1608 1609 ``readonly`` 1610 Enables exporting 9p share as a readonly mount for guests. By 1611 default read-write access is given. 1612 1613 ``socket=socket`` 1614 Enables proxy filesystem driver to use passed socket file for 1615 communicating with virtfs-proxy-helper(1). Usually a helper like 1616 libvirt will create socketpair and pass one of the fds as 1617 sock\_fd. 1618 1619 ``sock_fd`` 1620 Enables proxy filesystem driver to use passed 'sock\_fd' as the 1621 socket descriptor for interfacing with virtfs-proxy-helper(1). 1622 1623 ``fmode=fmode`` 1624 Specifies the default mode for newly created files on the host. 1625 Works only with security models "mapped-xattr" and 1626 "mapped-file". 1627 1628 ``dmode=dmode`` 1629 Specifies the default mode for newly created directories on the 1630 host. Works only with security models "mapped-xattr" and 1631 "mapped-file". 1632 1633 ``mount_tag=mount_tag`` 1634 Specifies the tag name to be used by the guest to mount this 1635 export point. 1636 1637 ``multidevs=multidevs`` 1638 Specifies how to deal with multiple devices being shared with a 1639 9p export. Supported behaviours are either "remap", "forbid" or 1640 "warn". The latter is the default behaviour on which virtfs 9p 1641 expects only one device to be shared with the same export, and 1642 if more than one device is shared and accessed via the same 9p 1643 export then only a warning message is logged (once) by qemu on 1644 host side. In order to avoid file ID collisions on guest you 1645 should either create a separate virtfs export for each device to 1646 be shared with guests (recommended way) or you might use "remap" 1647 instead which allows you to share multiple devices with only one 1648 export instead, which is achieved by remapping the original 1649 inode numbers from host to guest in a way that would prevent 1650 such collisions. Remapping inodes in such use cases is required 1651 because the original device IDs from host are never passed and 1652 exposed on guest. Instead all files of an export shared with 1653 virtfs always share the same device id on guest. So two files 1654 with identical inode numbers but from actually different devices 1655 on host would otherwise cause a file ID collision and hence 1656 potential misbehaviours on guest. "forbid" on the other hand 1657 assumes like "warn" that only one device is shared by the same 1658 export, however it will not only log a warning message but also 1659 deny access to additional devices on guest. Note though that 1660 "forbid" does currently not block all possible file access 1661 operations (e.g. readdir() would still return entries from other 1662 devices). 1663ERST 1664 1665DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1666 "-iscsi [user=user][,password=password]\n" 1667 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1668 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1669 " [,timeout=timeout]\n" 1670 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1671 1672SRST 1673``-iscsi`` 1674 Configure iSCSI session parameters. 1675ERST 1676 1677DEFHEADING() 1678 1679DEFHEADING(USB options:) 1680 1681DEF("usb", 0, QEMU_OPTION_usb, 1682 "-usb enable on-board USB host controller (if not enabled by default)\n", 1683 QEMU_ARCH_ALL) 1684SRST 1685``-usb`` 1686 Enable USB emulation on machine types with an on-board USB host 1687 controller (if not enabled by default). Note that on-board USB host 1688 controllers may not support USB 3.0. In this case 1689 ``-device qemu-xhci`` can be used instead on machines with PCI. 1690ERST 1691 1692DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1693 "-usbdevice name add the host or guest USB device 'name'\n", 1694 QEMU_ARCH_ALL) 1695SRST 1696``-usbdevice devname`` 1697 Add the USB device devname. Note that this option is deprecated, 1698 please use ``-device usb-...`` instead. See 1699 :ref:`usb_005fdevices`. 1700 1701 ``mouse`` 1702 Virtual Mouse. This will override the PS/2 mouse emulation when 1703 activated. 1704 1705 ``tablet`` 1706 Pointer device that uses absolute coordinates (like a 1707 touchscreen). This means QEMU is able to report the mouse 1708 position without having to grab the mouse. Also overrides the 1709 PS/2 mouse emulation when activated. 1710 1711 ``braille`` 1712 Braille device. This will use BrlAPI to display the braille 1713 output on a real or fake device. 1714ERST 1715 1716DEFHEADING() 1717 1718DEFHEADING(Display options:) 1719 1720DEF("display", HAS_ARG, QEMU_OPTION_display, 1721#if defined(CONFIG_SPICE) 1722 "-display spice-app[,gl=on|off]\n" 1723#endif 1724#if defined(CONFIG_SDL) 1725 "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off]\n" 1726 " [,window_close=on|off][,gl=on|core|es|off]\n" 1727#endif 1728#if defined(CONFIG_GTK) 1729 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1730#endif 1731#if defined(CONFIG_VNC) 1732 "-display vnc=<display>[,<optargs>]\n" 1733#endif 1734#if defined(CONFIG_CURSES) 1735 "-display curses[,charset=<encoding>]\n" 1736#endif 1737#if defined(CONFIG_OPENGL) 1738 "-display egl-headless[,rendernode=<file>]\n" 1739#endif 1740 "-display none\n" 1741 " select display backend type\n" 1742 " The default display is equivalent to\n " 1743#if defined(CONFIG_GTK) 1744 "\"-display gtk\"\n" 1745#elif defined(CONFIG_SDL) 1746 "\"-display sdl\"\n" 1747#elif defined(CONFIG_COCOA) 1748 "\"-display cocoa\"\n" 1749#elif defined(CONFIG_VNC) 1750 "\"-vnc localhost:0,to=99,id=default\"\n" 1751#else 1752 "\"-display none\"\n" 1753#endif 1754 , QEMU_ARCH_ALL) 1755SRST 1756``-display type`` 1757 Select type of display to use. This option is a replacement for the 1758 old style -sdl/-curses/... options. Use ``-display help`` to list 1759 the available display types. Valid values for type are 1760 1761 ``sdl`` 1762 Display video output via SDL (usually in a separate graphics 1763 window; see the SDL documentation for other possibilities). 1764 1765 ``curses`` 1766 Display video output via curses. For graphics device models 1767 which support a text mode, QEMU can display this output using a 1768 curses/ncurses interface. Nothing is displayed when the graphics 1769 device is in graphical mode or if the graphics device does not 1770 support a text mode. Generally only the VGA device models 1771 support text mode. The font charset used by the guest can be 1772 specified with the ``charset`` option, for example 1773 ``charset=CP850`` for IBM CP850 encoding. The default is 1774 ``CP437``. 1775 1776 ``none`` 1777 Do not display video output. The guest will still see an 1778 emulated graphics card, but its output will not be displayed to 1779 the QEMU user. This option differs from the -nographic option in 1780 that it only affects what is done with video output; -nographic 1781 also changes the destination of the serial and parallel port 1782 data. 1783 1784 ``gtk`` 1785 Display video output in a GTK window. This interface provides 1786 drop-down menus and other UI elements to configure and control 1787 the VM during runtime. 1788 1789 ``vnc`` 1790 Start a VNC server on display <arg> 1791 1792 ``egl-headless`` 1793 Offload all OpenGL operations to a local DRI device. For any 1794 graphical display, this display needs to be paired with either 1795 VNC or SPICE displays. 1796 1797 ``spice-app`` 1798 Start QEMU as a Spice server and launch the default Spice client 1799 application. The Spice server will redirect the serial consoles 1800 and QEMU monitors. (Since 4.0) 1801ERST 1802 1803DEF("nographic", 0, QEMU_OPTION_nographic, 1804 "-nographic disable graphical output and redirect serial I/Os to console\n", 1805 QEMU_ARCH_ALL) 1806SRST 1807``-nographic`` 1808 Normally, if QEMU is compiled with graphical window support, it 1809 displays output such as guest graphics, guest console, and the QEMU 1810 monitor in a window. With this option, you can totally disable 1811 graphical output so that QEMU is a simple command line application. 1812 The emulated serial port is redirected on the console and muxed with 1813 the monitor (unless redirected elsewhere explicitly). Therefore, you 1814 can still use QEMU to debug a Linux kernel with a serial console. 1815 Use C-a h for help on switching between the console and monitor. 1816ERST 1817 1818DEF("curses", 0, QEMU_OPTION_curses, 1819 "-curses shorthand for -display curses\n", 1820 QEMU_ARCH_ALL) 1821SRST 1822``-curses`` 1823 Normally, if QEMU is compiled with graphical window support, it 1824 displays output such as guest graphics, guest console, and the QEMU 1825 monitor in a window. With this option, QEMU can display the VGA 1826 output when in text mode using a curses/ncurses interface. Nothing 1827 is displayed in graphical mode. 1828ERST 1829 1830DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1831 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1832 QEMU_ARCH_ALL) 1833SRST 1834``-alt-grab`` 1835 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that 1836 this also affects the special keys (for fullscreen, monitor-mode 1837 switching, etc). 1838ERST 1839 1840DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1841 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1842 QEMU_ARCH_ALL) 1843SRST 1844``-ctrl-grab`` 1845 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this 1846 also affects the special keys (for fullscreen, monitor-mode 1847 switching, etc). 1848ERST 1849 1850DEF("no-quit", 0, QEMU_OPTION_no_quit, 1851 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1852SRST 1853``-no-quit`` 1854 Disable SDL window close capability. 1855ERST 1856 1857DEF("sdl", 0, QEMU_OPTION_sdl, 1858 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1859SRST 1860``-sdl`` 1861 Enable SDL. 1862ERST 1863 1864DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1865 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1866 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1867 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1868 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1869 " [,tls-ciphers=<list>]\n" 1870 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1871 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1872 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1873 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1874 " [,jpeg-wan-compression=[auto|never|always]]\n" 1875 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1876 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1877 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1878 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1879 " [,gl=[on|off]][,rendernode=<file>]\n" 1880 " enable spice\n" 1881 " at least one of {port, tls-port} is mandatory\n", 1882 QEMU_ARCH_ALL) 1883SRST 1884``-spice option[,option[,...]]`` 1885 Enable the spice remote desktop protocol. Valid options are 1886 1887 ``port=<nr>`` 1888 Set the TCP port spice is listening on for plaintext channels. 1889 1890 ``addr=<addr>`` 1891 Set the IP address spice is listening on. Default is any 1892 address. 1893 1894 ``ipv4``; \ ``ipv6``; \ ``unix`` 1895 Force using the specified IP version. 1896 1897 ``password=<secret>`` 1898 Set the password you need to authenticate. 1899 1900 ``sasl`` 1901 Require that the client use SASL to authenticate with the spice. 1902 The exact choice of authentication method used is controlled 1903 from the system / user's SASL configuration file for the 'qemu' 1904 service. This is typically found in /etc/sasl2/qemu.conf. If 1905 running QEMU as an unprivileged user, an environment variable 1906 SASL\_CONF\_PATH can be used to make it search alternate 1907 locations for the service config. While some SASL auth methods 1908 can also provide data encryption (eg GSSAPI), it is recommended 1909 that SASL always be combined with the 'tls' and 'x509' settings 1910 to enable use of SSL and server certificates. This ensures a 1911 data encryption preventing compromise of authentication 1912 credentials. 1913 1914 ``disable-ticketing`` 1915 Allow client connects without authentication. 1916 1917 ``disable-copy-paste`` 1918 Disable copy paste between the client and the guest. 1919 1920 ``disable-agent-file-xfer`` 1921 Disable spice-vdagent based file-xfer between the client and the 1922 guest. 1923 1924 ``tls-port=<nr>`` 1925 Set the TCP port spice is listening on for encrypted channels. 1926 1927 ``x509-dir=<dir>`` 1928 Set the x509 file directory. Expects same filenames as -vnc 1929 $display,x509=$dir 1930 1931 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>`` 1932 The x509 file names can also be configured individually. 1933 1934 ``tls-ciphers=<list>`` 1935 Specify which ciphers to use. 1936 1937 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]`` 1938 Force specific channel to be used with or without TLS 1939 encryption. The options can be specified multiple times to 1940 configure multiple channels. The special name "default" can be 1941 used to set the default mode. For channels which are not 1942 explicitly forced into one mode the spice client is allowed to 1943 pick tls/plaintext as he pleases. 1944 1945 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]`` 1946 Configure image compression (lossless). Default is auto\_glz. 1947 1948 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]`` 1949 Configure wan image compression (lossy for slow links). Default 1950 is auto. 1951 1952 ``streaming-video=[off|all|filter]`` 1953 Configure video stream detection. Default is off. 1954 1955 ``agent-mouse=[on|off]`` 1956 Enable/disable passing mouse events via vdagent. Default is on. 1957 1958 ``playback-compression=[on|off]`` 1959 Enable/disable audio stream compression (using celt 0.5.1). 1960 Default is on. 1961 1962 ``seamless-migration=[on|off]`` 1963 Enable/disable spice seamless migration. Default is off. 1964 1965 ``gl=[on|off]`` 1966 Enable/disable OpenGL context. Default is off. 1967 1968 ``rendernode=<file>`` 1969 DRM render node for OpenGL rendering. If not specified, it will 1970 pick the first available. (Since 2.9) 1971ERST 1972 1973DEF("portrait", 0, QEMU_OPTION_portrait, 1974 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1975 QEMU_ARCH_ALL) 1976SRST 1977``-portrait`` 1978 Rotate graphical output 90 deg left (only PXA LCD). 1979ERST 1980 1981DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1982 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1983 QEMU_ARCH_ALL) 1984SRST 1985``-rotate deg`` 1986 Rotate graphical output some deg left (only PXA LCD). 1987ERST 1988 1989DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1990 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1991 " select video card type\n", QEMU_ARCH_ALL) 1992SRST 1993``-vga type`` 1994 Select type of VGA card to emulate. Valid values for type are 1995 1996 ``cirrus`` 1997 Cirrus Logic GD5446 Video card. All Windows versions starting 1998 from Windows 95 should recognize and use this graphic card. For 1999 optimal performances, use 16 bit color depth in the guest and 2000 the host OS. (This card was the default before QEMU 2.2) 2001 2002 ``std`` 2003 Standard VGA card with Bochs VBE extensions. If your guest OS 2004 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if 2005 you want to use high resolution modes (>= 1280x1024x16) then you 2006 should use this option. (This card is the default since QEMU 2007 2.2) 2008 2009 ``vmware`` 2010 VMWare SVGA-II compatible adapter. Use it if you have 2011 sufficiently recent XFree86/XOrg server or Windows guest with a 2012 driver for this card. 2013 2014 ``qxl`` 2015 QXL paravirtual graphic card. It is VGA compatible (including 2016 VESA 2.0 VBE support). Works best with qxl guest drivers 2017 installed though. Recommended choice when using the spice 2018 protocol. 2019 2020 ``tcx`` 2021 (sun4m only) Sun TCX framebuffer. This is the default 2022 framebuffer for sun4m machines and offers both 8-bit and 24-bit 2023 colour depths at a fixed resolution of 1024x768. 2024 2025 ``cg3`` 2026 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit 2027 framebuffer for sun4m machines available in both 1024x768 2028 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people 2029 wishing to run older Solaris versions. 2030 2031 ``virtio`` 2032 Virtio VGA card. 2033 2034 ``none`` 2035 Disable VGA card. 2036ERST 2037 2038DEF("full-screen", 0, QEMU_OPTION_full_screen, 2039 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 2040SRST 2041``-full-screen`` 2042 Start in full screen. 2043ERST 2044 2045DEF("g", HAS_ARG, QEMU_OPTION_g , 2046 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 2047 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 2048SRST 2049``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]`` 2050 Set the initial graphical resolution and depth (PPC, SPARC only). 2051 2052 For PPC the default is 800x600x32. 2053 2054 For SPARC with the TCX graphics device, the default is 1024x768x8 2055 with the option of 1024x768x24. For cgthree, the default is 2056 1024x768x8 with the option of 1152x900x8 for people who wish to use 2057 OBP. 2058ERST 2059 2060DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 2061 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 2062SRST 2063``-vnc display[,option[,option[,...]]]`` 2064 Normally, if QEMU is compiled with graphical window support, it 2065 displays output such as guest graphics, guest console, and the QEMU 2066 monitor in a window. With this option, you can have QEMU listen on 2067 VNC display display and redirect the VGA display over the VNC 2068 session. It is very useful to enable the usb tablet device when 2069 using this option (option ``-device usb-tablet``). When using the 2070 VNC display, you must use the ``-k`` parameter to set the keyboard 2071 layout if you are not using en-us. Valid syntax for the display is 2072 2073 ``to=L`` 2074 With this option, QEMU will try next available VNC displays, 2075 until the number L, if the origianlly defined "-vnc display" is 2076 not available, e.g. port 5900+display is already used by another 2077 application. By default, to=0. 2078 2079 ``host:d`` 2080 TCP connections will only be allowed from host on display d. By 2081 convention the TCP port is 5900+d. Optionally, host can be 2082 omitted in which case the server will accept connections from 2083 any host. 2084 2085 ``unix:path`` 2086 Connections will be allowed over UNIX domain sockets where path 2087 is the location of a unix socket to listen for connections on. 2088 2089 ``none`` 2090 VNC is initialized but not started. The monitor ``change`` 2091 command can be used to later start the VNC server. 2092 2093 Following the display value there may be one or more option flags 2094 separated by commas. Valid options are 2095 2096 ``reverse`` 2097 Connect to a listening VNC client via a "reverse" connection. 2098 The client is specified by the display. For reverse network 2099 connections (host:d,``reverse``), the d argument is a TCP port 2100 number, not a display number. 2101 2102 ``websocket`` 2103 Opens an additional TCP listening port dedicated to VNC 2104 Websocket connections. If a bare websocket option is given, the 2105 Websocket port is 5700+display. An alternative port can be 2106 specified with the syntax ``websocket``\ =port. 2107 2108 If host is specified connections will only be allowed from this 2109 host. It is possible to control the websocket listen address 2110 independently, using the syntax ``websocket``\ =host:port. 2111 2112 If no TLS credentials are provided, the websocket connection 2113 runs in unencrypted mode. If TLS credentials are provided, the 2114 websocket connection requires encrypted client connections. 2115 2116 ``password`` 2117 Require that password based authentication is used for client 2118 connections. 2119 2120 The password must be set separately using the ``set_password`` 2121 command in the :ref:`pcsys_005fmonitor`. The 2122 syntax to change your password is: 2123 ``set_password <protocol> <password>`` where <protocol> could be 2124 either "vnc" or "spice". 2125 2126 If you would like to change <protocol> password expiration, you 2127 should use ``expire_password <protocol> <expiration-time>`` 2128 where expiration time could be one of the following options: 2129 now, never, +seconds or UNIX time of expiration, e.g. +60 to 2130 make password expire in 60 seconds, or 1335196800 to make 2131 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for 2132 this date and time). 2133 2134 You can also use keywords "now" or "never" for the expiration 2135 time to allow <protocol> password to expire immediately or never 2136 expire. 2137 2138 ``tls-creds=ID`` 2139 Provides the ID of a set of TLS credentials to use to secure the 2140 VNC server. They will apply to both the normal VNC server socket 2141 and the websocket socket (if enabled). Setting TLS credentials 2142 will cause the VNC server socket to enable the VeNCrypt auth 2143 mechanism. The credentials should have been previously created 2144 using the ``-object tls-creds`` argument. 2145 2146 ``tls-authz=ID`` 2147 Provides the ID of the QAuthZ authorization object against which 2148 the client's x509 distinguished name will validated. This object 2149 is only resolved at time of use, so can be deleted and recreated 2150 on the fly while the VNC server is active. If missing, it will 2151 default to denying access. 2152 2153 ``sasl`` 2154 Require that the client use SASL to authenticate with the VNC 2155 server. The exact choice of authentication method used is 2156 controlled from the system / user's SASL configuration file for 2157 the 'qemu' service. This is typically found in 2158 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, 2159 an environment variable SASL\_CONF\_PATH can be used to make it 2160 search alternate locations for the service config. While some 2161 SASL auth methods can also provide data encryption (eg GSSAPI), 2162 it is recommended that SASL always be combined with the 'tls' 2163 and 'x509' settings to enable use of SSL and server 2164 certificates. This ensures a data encryption preventing 2165 compromise of authentication credentials. See the 2166 :ref:`vnc_005fsecurity` section for details on 2167 using SASL authentication. 2168 2169 ``sasl-authz=ID`` 2170 Provides the ID of the QAuthZ authorization object against which 2171 the client's SASL username will validated. This object is only 2172 resolved at time of use, so can be deleted and recreated on the 2173 fly while the VNC server is active. If missing, it will default 2174 to denying access. 2175 2176 ``acl`` 2177 Legacy method for enabling authorization of clients against the 2178 x509 distinguished name and SASL username. It results in the 2179 creation of two ``authz-list`` objects with IDs of 2180 ``vnc.username`` and ``vnc.x509dname``. The rules for these 2181 objects must be configured with the HMP ACL commands. 2182 2183 This option is deprecated and should no longer be used. The new 2184 ``sasl-authz`` and ``tls-authz`` options are a replacement. 2185 2186 ``lossy`` 2187 Enable lossy compression methods (gradient, JPEG, ...). If this 2188 option is set, VNC client may receive lossy framebuffer updates 2189 depending on its encoding settings. Enabling this option can 2190 save a lot of bandwidth at the expense of quality. 2191 2192 ``non-adaptive`` 2193 Disable adaptive encodings. Adaptive encodings are enabled by 2194 default. An adaptive encoding will try to detect frequently 2195 updated screen regions, and send updates in these regions using 2196 a lossy encoding (like JPEG). This can be really helpful to save 2197 bandwidth when playing videos. Disabling adaptive encodings 2198 restores the original static behavior of encodings like Tight. 2199 2200 ``share=[allow-exclusive|force-shared|ignore]`` 2201 Set display sharing policy. 'allow-exclusive' allows clients to 2202 ask for exclusive access. As suggested by the rfb spec this is 2203 implemented by dropping other connections. Connecting multiple 2204 clients in parallel requires all clients asking for a shared 2205 session (vncviewer: -shared switch). This is the default. 2206 'force-shared' disables exclusive client access. Useful for 2207 shared desktop sessions, where you don't want someone forgetting 2208 specify -shared disconnect everybody else. 'ignore' completely 2209 ignores the shared flag and allows everybody connect 2210 unconditionally. Doesn't conform to the rfb spec but is 2211 traditional QEMU behavior. 2212 2213 ``key-delay-ms`` 2214 Set keyboard delay, for key down and key up events, in 2215 milliseconds. Default is 10. Keyboards are low-bandwidth 2216 devices, so this slowdown can help the device and guest to keep 2217 up and not lose events in case events are arriving in bulk. 2218 Possible causes for the latter are flaky network connections, or 2219 scripts for automated testing. 2220 2221 ``audiodev=audiodev`` 2222 Use the specified audiodev when the VNC client requests audio 2223 transmission. When not using an -audiodev argument, this option 2224 must be omitted, otherwise is must be present and specify a 2225 valid audiodev. 2226ERST 2227 2228ARCHHEADING(, QEMU_ARCH_I386) 2229 2230ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2231 2232DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2233 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2234 QEMU_ARCH_I386) 2235SRST 2236``-win2k-hack`` 2237 Use it when installing Windows 2000 to avoid a disk full bug. After 2238 Windows 2000 is installed, you no longer need this option (this 2239 option slows down the IDE transfers). 2240ERST 2241 2242DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2243 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2244 QEMU_ARCH_I386) 2245SRST 2246``-no-fd-bootchk`` 2247 Disable boot signature checking for floppy disks in BIOS. May be 2248 needed to boot from old floppy disks. 2249ERST 2250 2251DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2252 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2253SRST 2254``-no-acpi`` 2255 Disable ACPI (Advanced Configuration and Power Interface) support. 2256 Use it if your guest OS complains about ACPI problems (PC target 2257 machine only). 2258ERST 2259 2260DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2261 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2262SRST 2263``-no-hpet`` 2264 Disable HPET support. 2265ERST 2266 2267DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2268 "-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" 2269 " ACPI table description\n", QEMU_ARCH_I386) 2270SRST 2271``-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]...]`` 2272 Add ACPI table with specified header fields and context from 2273 specified files. For file=, take whole ACPI table from the specified 2274 files, including all ACPI headers (possible overridden by other 2275 options). For data=, only data portion of the table is used, all 2276 header information is specified in the command line. If a SLIC table 2277 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id 2278 fields will override the same in the RSDT and the FADT (a.k.a. 2279 FACP), in order to ensure the field matches required by the 2280 Microsoft SLIC spec and the ACPI spec. 2281ERST 2282 2283DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2284 "-smbios file=binary\n" 2285 " load SMBIOS entry from binary file\n" 2286 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2287 " [,uefi=on|off]\n" 2288 " specify SMBIOS type 0 fields\n" 2289 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2290 " [,uuid=uuid][,sku=str][,family=str]\n" 2291 " specify SMBIOS type 1 fields\n" 2292 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2293 " [,asset=str][,location=str]\n" 2294 " specify SMBIOS type 2 fields\n" 2295 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2296 " [,sku=str]\n" 2297 " specify SMBIOS type 3 fields\n" 2298 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2299 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n" 2300 " specify SMBIOS type 4 fields\n" 2301 "-smbios type=11[,value=str][,path=filename]\n" 2302 " specify SMBIOS type 11 fields\n" 2303 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2304 " [,asset=str][,part=str][,speed=%d]\n" 2305 " specify SMBIOS type 17 fields\n", 2306 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2307SRST 2308``-smbios file=binary`` 2309 Load SMBIOS entry from binary file. 2310 2311``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]`` 2312 Specify SMBIOS type 0 fields 2313 2314``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]`` 2315 Specify SMBIOS type 1 fields 2316 2317``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]`` 2318 Specify SMBIOS type 2 fields 2319 2320``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]`` 2321 Specify SMBIOS type 3 fields 2322 2323``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str]`` 2324 Specify SMBIOS type 4 fields 2325 2326``-smbios type=11[,value=str][,path=filename]`` 2327 Specify SMBIOS type 11 fields 2328 2329 This argument can be repeated multiple times, and values are added in the order they are parsed. 2330 Applications intending to use OEM strings data are encouraged to use their application name as 2331 a prefix for the value string. This facilitates passing information for multiple applications 2332 concurrently. 2333 2334 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax 2335 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes. 2336 2337 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to 2338 the SMBIOS table in the order in which they appear. 2339 2340 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535 2341 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the 2342 guest. Instead it should be used as a indicator to inform the guest where to locate the real 2343 data set, for example, by specifying the serial ID of a block device. 2344 2345 An example passing three strings is 2346 2347 .. parsed-literal:: 2348 2349 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\ 2350 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\ 2351 path=/some/file/with/oemstringsdata.txt 2352 2353 In the guest OS this is visible with the ``dmidecode`` command 2354 2355 .. parsed-literal:: 2356 2357 $ dmidecode -t 11 2358 Handle 0x0E00, DMI type 11, 5 bytes 2359 OEM Strings 2360 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/ 2361 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os 2362 String 3: myapp:some extra data 2363 2364 2365``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]`` 2366 Specify SMBIOS type 17 fields 2367ERST 2368 2369DEFHEADING() 2370 2371DEFHEADING(Network options:) 2372 2373DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2374#ifdef CONFIG_SLIRP 2375 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2376 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2377 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2378 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2379 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2380#ifndef _WIN32 2381 "[,smb=dir[,smbserver=addr]]\n" 2382#endif 2383 " configure a user mode network backend with ID 'str',\n" 2384 " its DHCP server and optional services\n" 2385#endif 2386#ifdef _WIN32 2387 "-netdev tap,id=str,ifname=name\n" 2388 " configure a host TAP network backend with ID 'str'\n" 2389#else 2390 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2391 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2392 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2393 " [,poll-us=n]\n" 2394 " configure a host TAP network backend with ID 'str'\n" 2395 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2396 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2397 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2398 " to deconfigure it\n" 2399 " use '[down]script=no' to disable script execution\n" 2400 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2401 " configure it\n" 2402 " use 'fd=h' to connect to an already opened TAP interface\n" 2403 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2404 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2405 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2406 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2407 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2408 " use vhost=on to enable experimental in kernel accelerator\n" 2409 " (only has effect for virtio guests which use MSIX)\n" 2410 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2411 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2412 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2413 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2414 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2415 " spent on busy polling for vhost net\n" 2416 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2417 " configure a host TAP network backend with ID 'str' that is\n" 2418 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2419 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2420#endif 2421#ifdef __linux__ 2422 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2423 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2424 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2425 " [,rxcookie=rxcookie][,offset=offset]\n" 2426 " configure a network backend with ID 'str' connected to\n" 2427 " an Ethernet over L2TPv3 pseudowire.\n" 2428 " Linux kernel 3.3+ as well as most routers can talk\n" 2429 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2430 " VM to a router and even VM to Host. It is a nearly-universal\n" 2431 " standard (RFC3931). Note - this implementation uses static\n" 2432 " pre-configured tunnels (same as the Linux kernel).\n" 2433 " use 'src=' to specify source address\n" 2434 " use 'dst=' to specify destination address\n" 2435 " use 'udp=on' to specify udp encapsulation\n" 2436 " use 'srcport=' to specify source udp port\n" 2437 " use 'dstport=' to specify destination udp port\n" 2438 " use 'ipv6=on' to force v6\n" 2439 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2440 " well as a weak security measure\n" 2441 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2442 " use 'txcookie=0x012345678' to specify a txcookie\n" 2443 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2444 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2445 " use 'pincounter=on' to work around broken counter handling in peer\n" 2446 " use 'offset=X' to add an extra offset between header and data\n" 2447#endif 2448 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2449 " configure a network backend to connect to another network\n" 2450 " using a socket connection\n" 2451 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2452 " configure a network backend to connect to a multicast maddr and port\n" 2453 " use 'localaddr=addr' to specify the host address to send packets from\n" 2454 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2455 " configure a network backend to connect to another network\n" 2456 " using an UDP tunnel\n" 2457#ifdef CONFIG_VDE 2458 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2459 " configure a network backend to connect to port 'n' of a vde switch\n" 2460 " running on host and listening for incoming connections on 'socketpath'.\n" 2461 " Use group 'groupname' and mode 'octalmode' to change default\n" 2462 " ownership and permissions for communication port.\n" 2463#endif 2464#ifdef CONFIG_NETMAP 2465 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2466 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2467 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2468 " netmap device, defaults to '/dev/netmap')\n" 2469#endif 2470#ifdef CONFIG_POSIX 2471 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2472 " configure a vhost-user network, backed by a chardev 'dev'\n" 2473#endif 2474#ifdef __linux__ 2475 "-netdev vhost-vdpa,id=str,vhostdev=/path/to/dev\n" 2476 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n" 2477#endif 2478 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2479 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2480DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2481 "-nic [tap|bridge|" 2482#ifdef CONFIG_SLIRP 2483 "user|" 2484#endif 2485#ifdef __linux__ 2486 "l2tpv3|" 2487#endif 2488#ifdef CONFIG_VDE 2489 "vde|" 2490#endif 2491#ifdef CONFIG_NETMAP 2492 "netmap|" 2493#endif 2494#ifdef CONFIG_POSIX 2495 "vhost-user|" 2496#endif 2497 "socket][,option][,...][mac=macaddr]\n" 2498 " initialize an on-board / default host NIC (using MAC address\n" 2499 " macaddr) and connect it to the given host network backend\n" 2500 "-nic none use it alone to have zero network devices (the default is to\n" 2501 " provided a 'user' network connection)\n", 2502 QEMU_ARCH_ALL) 2503DEF("net", HAS_ARG, QEMU_OPTION_net, 2504 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2505 " configure or create an on-board (or machine default) NIC and\n" 2506 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2507 "-net [" 2508#ifdef CONFIG_SLIRP 2509 "user|" 2510#endif 2511 "tap|" 2512 "bridge|" 2513#ifdef CONFIG_VDE 2514 "vde|" 2515#endif 2516#ifdef CONFIG_NETMAP 2517 "netmap|" 2518#endif 2519 "socket][,option][,option][,...]\n" 2520 " old way to initialize a host network interface\n" 2521 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2522SRST 2523``-nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]`` 2524 This option is a shortcut for configuring both the on-board 2525 (default) guest NIC hardware and the host network backend in one go. 2526 The host backend options are the same as with the corresponding 2527 ``-netdev`` options below. The guest NIC model can be set with 2528 ``model=modelname``. Use ``model=help`` to list the available device 2529 types. The hardware MAC address can be set with ``mac=macaddr``. 2530 2531 The following two example do exactly the same, to show how ``-nic`` 2532 can be used to shorten the command line length: 2533 2534 .. parsed-literal:: 2535 2536 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2537 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2538 2539``-nic none`` 2540 Indicate that no network devices should be configured. It is used to 2541 override the default configuration (default NIC with "user" host 2542 network backend) which is activated if no other networking options 2543 are provided. 2544 2545``-netdev user,id=id[,option][,option][,...]`` 2546 Configure user mode host network backend which requires no 2547 administrator privilege to run. Valid options are: 2548 2549 ``id=id`` 2550 Assign symbolic name for use in monitor commands. 2551 2552 ``ipv4=on|off and ipv6=on|off`` 2553 Specify that either IPv4 or IPv6 must be enabled. If neither is 2554 specified both protocols are enabled. 2555 2556 ``net=addr[/mask]`` 2557 Set IP network address the guest will see. Optionally specify 2558 the netmask, either in the form a.b.c.d or as number of valid 2559 top-most bits. Default is 10.0.2.0/24. 2560 2561 ``host=addr`` 2562 Specify the guest-visible address of the host. Default is the 2563 2nd IP in the guest network, i.e. x.x.x.2. 2564 2565 ``ipv6-net=addr[/int]`` 2566 Set IPv6 network address the guest will see (default is 2567 fec0::/64). The network prefix is given in the usual hexadecimal 2568 IPv6 address notation. The prefix size is optional, and is given 2569 as the number of valid top-most bits (default is 64). 2570 2571 ``ipv6-host=addr`` 2572 Specify the guest-visible IPv6 address of the host. Default is 2573 the 2nd IPv6 in the guest network, i.e. xxxx::2. 2574 2575 ``restrict=on|off`` 2576 If this option is enabled, the guest will be isolated, i.e. it 2577 will not be able to contact the host and no guest IP packets 2578 will be routed over the host to the outside. This option does 2579 not affect any explicitly set forwarding rules. 2580 2581 ``hostname=name`` 2582 Specifies the client hostname reported by the built-in DHCP 2583 server. 2584 2585 ``dhcpstart=addr`` 2586 Specify the first of the 16 IPs the built-in DHCP server can 2587 assign. Default is the 15th to 31st IP in the guest network, 2588 i.e. x.x.x.15 to x.x.x.31. 2589 2590 ``dns=addr`` 2591 Specify the guest-visible address of the virtual nameserver. The 2592 address must be different from the host address. Default is the 2593 3rd IP in the guest network, i.e. x.x.x.3. 2594 2595 ``ipv6-dns=addr`` 2596 Specify the guest-visible address of the IPv6 virtual 2597 nameserver. The address must be different from the host address. 2598 Default is the 3rd IP in the guest network, i.e. xxxx::3. 2599 2600 ``dnssearch=domain`` 2601 Provides an entry for the domain-search list sent by the 2602 built-in DHCP server. More than one domain suffix can be 2603 transmitted by specifying this option multiple times. If 2604 supported, this will cause the guest to automatically try to 2605 append the given domain suffix(es) in case a domain name can not 2606 be resolved. 2607 2608 Example: 2609 2610 .. parsed-literal:: 2611 2612 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2613 2614 ``domainname=domain`` 2615 Specifies the client domain name reported by the built-in DHCP 2616 server. 2617 2618 ``tftp=dir`` 2619 When using the user mode network stack, activate a built-in TFTP 2620 server. The files in dir will be exposed as the root of a TFTP 2621 server. The TFTP client on the guest must be configured in 2622 binary mode (use the command ``bin`` of the Unix TFTP client). 2623 2624 ``tftp-server-name=name`` 2625 In BOOTP reply, broadcast name as the "TFTP server name" 2626 (RFC2132 option 66). This can be used to advise the guest to 2627 load boot files or configurations from a different server than 2628 the host address. 2629 2630 ``bootfile=file`` 2631 When using the user mode network stack, broadcast file as the 2632 BOOTP filename. In conjunction with ``tftp``, this can be used 2633 to network boot a guest from a local directory. 2634 2635 Example (using pxelinux): 2636 2637 .. parsed-literal:: 2638 2639 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\ 2640 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2641 2642 ``smb=dir[,smbserver=addr]`` 2643 When using the user mode network stack, activate a built-in SMB 2644 server so that Windows OSes can access to the host files in 2645 ``dir`` transparently. The IP address of the SMB server can be 2646 set to addr. By default the 4th IP in the guest network is used, 2647 i.e. x.x.x.4. 2648 2649 In the guest Windows OS, the line: 2650 2651 :: 2652 2653 10.0.2.4 smbserver 2654 2655 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows 2656 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows 2657 NT/2000). 2658 2659 Then ``dir`` can be accessed in ``\\smbserver\qemu``. 2660 2661 Note that a SAMBA server must be installed on the host OS. 2662 2663 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport`` 2664 Redirect incoming TCP or UDP connections to the host port 2665 hostport to the guest IP address guestaddr on guest port 2666 guestport. If guestaddr is not specified, its value is x.x.x.15 2667 (default first address given by the built-in DHCP server). By 2668 specifying hostaddr, the rule can be bound to a specific host 2669 interface. If no connection type is set, TCP is used. This 2670 option can be given multiple times. 2671 2672 For example, to redirect host X11 connection from screen 1 to 2673 guest screen 0, use the following: 2674 2675 .. parsed-literal:: 2676 2677 # on the host 2678 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2679 # this host xterm should open in the guest X11 server 2680 xterm -display :1 2681 2682 To redirect telnet connections from host port 5555 to telnet 2683 port on the guest, use the following: 2684 2685 .. parsed-literal:: 2686 2687 # on the host 2688 |qemu_system| -nic user,hostfwd=tcp::5555-:23 2689 telnet localhost 5555 2690 2691 Then when you use on the host ``telnet localhost 5555``, you 2692 connect to the guest telnet server. 2693 2694 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command`` 2695 Forward guest TCP connections to the IP address server on port 2696 port to the character device dev or to a program executed by 2697 cmd:command which gets spawned for each connection. This option 2698 can be given multiple times. 2699 2700 You can either use a chardev directly and have that one used 2701 throughout QEMU's lifetime, like in the following example: 2702 2703 .. parsed-literal:: 2704 2705 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2706 # the guest accesses it 2707 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2708 2709 Or you can execute a command on every TCP connection established 2710 by the guest, so that QEMU behaves similar to an inetd process 2711 for that virtual server: 2712 2713 .. parsed-literal:: 2714 2715 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2716 # and connect the TCP stream to its stdin/stdout 2717 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2718 2719``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` 2720 Configure a host TAP network backend with ID id. 2721 2722 Use the network script file to configure it and the network script 2723 dfile to deconfigure it. If name is not provided, the OS 2724 automatically provides one. The default network configure script is 2725 ``/etc/qemu-ifup`` and the default network deconfigure script is 2726 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to 2727 disable script execution. 2728 2729 If running QEMU as an unprivileged user, use the network helper 2730 to configure the TAP interface and attach it to the bridge. 2731 The default network helper executable is 2732 ``/path/to/qemu-bridge-helper`` and the default bridge device is 2733 ``br0``. 2734 2735 ``fd``\ =h can be used to specify the handle of an already opened 2736 host TAP interface. 2737 2738 Examples: 2739 2740 .. parsed-literal:: 2741 2742 #launch a QEMU instance with the default network script 2743 |qemu_system| linux.img -nic tap 2744 2745 .. parsed-literal:: 2746 2747 #launch a QEMU instance with two NICs, each one connected 2748 #to a TAP device 2749 |qemu_system| linux.img \\ 2750 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\ 2751 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2752 2753 .. parsed-literal:: 2754 2755 #launch a QEMU instance with the default network helper to 2756 #connect a TAP device to bridge br0 2757 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 2758 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2759 2760``-netdev bridge,id=id[,br=bridge][,helper=helper]`` 2761 Connect a host TAP network interface to a host bridge device. 2762 2763 Use the network helper helper to configure the TAP interface and 2764 attach it to the bridge. The default network helper executable is 2765 ``/path/to/qemu-bridge-helper`` and the default bridge device is 2766 ``br0``. 2767 2768 Examples: 2769 2770 .. parsed-literal:: 2771 2772 #launch a QEMU instance with the default network helper to 2773 #connect a TAP device to bridge br0 2774 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2775 2776 .. parsed-literal:: 2777 2778 #launch a QEMU instance with the default network helper to 2779 #connect a TAP device to bridge qemubr0 2780 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2781 2782``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]`` 2783 This host network backend can be used to connect the guest's network 2784 to another QEMU virtual machine using a TCP socket connection. If 2785 ``listen`` is specified, QEMU waits for incoming connections on port 2786 (host is optional). ``connect`` is used to connect to another QEMU 2787 instance using the ``listen`` option. ``fd``\ =h specifies an 2788 already opened TCP socket. 2789 2790 Example: 2791 2792 .. parsed-literal:: 2793 2794 # launch a first QEMU instance 2795 |qemu_system| linux.img \\ 2796 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 2797 -netdev socket,id=n1,listen=:1234 2798 # connect the network of this instance to the network of the first instance 2799 |qemu_system| linux.img \\ 2800 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 2801 -netdev socket,id=n2,connect=127.0.0.1:1234 2802 2803``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]`` 2804 Configure a socket host network backend to share the guest's network 2805 traffic with another QEMU virtual machines using a UDP multicast 2806 socket, effectively making a bus for every QEMU with same multicast 2807 address maddr and port. NOTES: 2808 2809 1. Several QEMU can be running on different hosts and share same bus 2810 (assuming correct multicast setup for these hosts). 2811 2812 2. mcast support is compatible with User Mode Linux (argument 2813 ``ethN=mcast``), see http://user-mode-linux.sf.net. 2814 2815 3. Use ``fd=h`` to specify an already opened UDP multicast socket. 2816 2817 Example: 2818 2819 .. parsed-literal:: 2820 2821 # launch one QEMU instance 2822 |qemu_system| linux.img \\ 2823 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 2824 -netdev socket,id=n1,mcast=230.0.0.1:1234 2825 # launch another QEMU instance on same "bus" 2826 |qemu_system| linux.img \\ 2827 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 2828 -netdev socket,id=n2,mcast=230.0.0.1:1234 2829 # launch yet another QEMU instance on same "bus" 2830 |qemu_system| linux.img \\ 2831 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\ 2832 -netdev socket,id=n3,mcast=230.0.0.1:1234 2833 2834 Example (User Mode Linux compat.): 2835 2836 .. parsed-literal:: 2837 2838 # launch QEMU instance (note mcast address selected is UML's default) 2839 |qemu_system| linux.img \\ 2840 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 2841 -netdev socket,id=n1,mcast=239.192.168.1:1102 2842 # launch UML 2843 /path/to/linux ubd0=/path/to/root_fs eth0=mcast 2844 2845 Example (send packets from host's 1.2.3.4): 2846 2847 .. parsed-literal:: 2848 2849 |qemu_system| linux.img \\ 2850 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 2851 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2852 2853``-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]`` 2854 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931) 2855 is a popular protocol to transport Ethernet (and other Layer 2) data 2856 frames between two systems. It is present in routers, firewalls and 2857 the Linux kernel (from version 3.3 onwards). 2858 2859 This transport allows a VM to communicate to another VM, router or 2860 firewall directly. 2861 2862 ``src=srcaddr`` 2863 source address (mandatory) 2864 2865 ``dst=dstaddr`` 2866 destination address (mandatory) 2867 2868 ``udp`` 2869 select udp encapsulation (default is ip). 2870 2871 ``srcport=srcport`` 2872 source udp port. 2873 2874 ``dstport=dstport`` 2875 destination udp port. 2876 2877 ``ipv6`` 2878 force v6, otherwise defaults to v4. 2879 2880 ``rxcookie=rxcookie``; \ ``txcookie=txcookie`` 2881 Cookies are a weak form of security in the l2tpv3 specification. 2882 Their function is mostly to prevent misconfiguration. By default 2883 they are 32 bit. 2884 2885 ``cookie64`` 2886 Set cookie size to 64 bit instead of the default 32 2887 2888 ``counter=off`` 2889 Force a 'cut-down' L2TPv3 with no counter as in 2890 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2891 2892 ``pincounter=on`` 2893 Work around broken counter handling in peer. This may also help 2894 on networks which have packet reorder. 2895 2896 ``offset=offset`` 2897 Add an extra offset between header and data 2898 2899 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to 2900 the bridge br-lan on the remote Linux host 1.2.3.4: 2901 2902 .. parsed-literal:: 2903 2904 # Setup tunnel on linux host using raw ip as encapsulation 2905 # on 1.2.3.4 2906 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\ 2907 encap udp udp_sport 16384 udp_dport 16384 2908 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\ 2909 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2910 ifconfig vmtunnel0 mtu 1500 2911 ifconfig vmtunnel0 up 2912 brctl addif br-lan vmtunnel0 2913 2914 2915 # on 4.3.2.1 2916 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2917 2918 |qemu_system| linux.img -device e1000,netdev=n1 \\ 2919 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2920 2921``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]`` 2922 Configure VDE backend to connect to PORT n of a vde switch running 2923 on host and listening for incoming connections on socketpath. Use 2924 GROUP groupname and MODE octalmode to change default ownership and 2925 permissions for communication port. This option is only available if 2926 QEMU has been compiled with vde support enabled. 2927 2928 Example: 2929 2930 .. parsed-literal:: 2931 2932 # launch vde switch 2933 vde_switch -F -sock /tmp/myswitch 2934 # launch QEMU instance 2935 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch 2936 2937``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` 2938 Establish a vhost-user netdev, backed by a chardev id. The chardev 2939 should be a unix domain socket backed one. The vhost-user uses a 2940 specifically defined protocol to pass vhost ioctl replacement 2941 messages to an application on the other end of the socket. On 2942 non-MSIX guests, the feature can be forced with vhostforce. Use 2943 'queues=n' to specify the number of queues to be created for 2944 multiqueue vhost-user. 2945 2946 Example: 2947 2948 :: 2949 2950 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2951 -numa node,memdev=mem \ 2952 -chardev socket,id=chr0,path=/path/to/socket \ 2953 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2954 -device virtio-net-pci,netdev=net0 2955 2956``-netdev vhost-vdpa,vhostdev=/path/to/dev`` 2957 Establish a vhost-vdpa netdev. 2958 2959 vDPA device is a device that uses a datapath which complies with 2960 the virtio specifications with a vendor specific control path. 2961 vDPA devices can be both physically located on the hardware or 2962 emulated by software. 2963 2964``-netdev hubport,id=id,hubid=hubid[,netdev=nd]`` 2965 Create a hub port on the emulated hub with ID hubid. 2966 2967 The hubport netdev lets you connect a NIC to a QEMU emulated hub 2968 instead of a single netdev. Alternatively, you can also connect the 2969 hubport to another netdev with ID nd by using the ``netdev=nd`` 2970 option. 2971 2972``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]`` 2973 Legacy option to configure or create an on-board (or machine 2974 default) Network Interface Card(NIC) and connect it either to the 2975 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd. 2976 If model is omitted, then the default NIC model associated with the 2977 machine type is used. Note that the default NIC model may change in 2978 future QEMU releases, so it is highly recommended to always specify 2979 a model. Optionally, the MAC address can be changed to mac, the 2980 device address set to addr (PCI cards only), and a name can be 2981 assigned for use in monitor commands. Optionally, for PCI cards, you 2982 can specify the number v of MSI-X vectors that the card should have; 2983 this option currently only affects virtio cards; set v = 0 to 2984 disable MSI-X. If no ``-net`` option is specified, a single NIC is 2985 created. QEMU can emulate several different models of network card. 2986 Use ``-net nic,model=help`` for a list of available devices for your 2987 target. 2988 2989``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]`` 2990 Configure a host network backend (with the options corresponding to 2991 the same ``-netdev`` option) and connect it to the emulated hub 0 2992 (the default hub). Use name to specify the name of the hub port. 2993ERST 2994 2995DEFHEADING() 2996 2997DEFHEADING(Character device options:) 2998 2999DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 3000 "-chardev help\n" 3001 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3002 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 3003 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 3004 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 3005 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 3006 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" 3007 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 3008 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 3009 " [,logfile=PATH][,logappend=on|off]\n" 3010 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3011 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 3012 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3013 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 3014 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3015 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3016#ifdef _WIN32 3017 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3018 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3019#else 3020 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3021 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 3022#endif 3023#ifdef CONFIG_BRLAPI 3024 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3025#endif 3026#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 3027 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 3028 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3029 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3030#endif 3031#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 3032 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3033 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3034#endif 3035#if defined(CONFIG_SPICE) 3036 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3037 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3038#endif 3039 , QEMU_ARCH_ALL 3040) 3041 3042SRST 3043The general form of a character device option is: 3044 3045``-chardev backend,id=id[,mux=on|off][,options]`` 3046 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, 3047 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, 3048 ``pty``, ``stdio``, ``braille``, ``tty``, ``parallel``, ``parport``, 3049 ``spicevmc``, ``spiceport``. The specific backend will determine the 3050 applicable options. 3051 3052 Use ``-chardev help`` to print all available chardev backend types. 3053 3054 All devices must have an id, which can be any string up to 127 3055 characters long. It is used to uniquely identify this device in 3056 other command line directives. 3057 3058 A character device may be used in multiplexing mode by multiple 3059 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is 3060 a "1:N" device, and here the "1" end is your specified chardev 3061 backend, and the "N" end is the various parts of QEMU that can talk 3062 to a chardev. If you create a chardev with ``id=myid`` and 3063 ``mux=on``, QEMU will create a multiplexer with your specified ID, 3064 and you can then configure multiple front ends to use that chardev 3065 ID for their input/output. Up to four different front ends can be 3066 connected to a single multiplexed chardev. (Without multiplexing 3067 enabled, a chardev can only be used by a single front end.) For 3068 instance you could use this to allow a single stdio chardev to be 3069 used by two serial ports and the QEMU monitor: 3070 3071 :: 3072 3073 -chardev stdio,mux=on,id=char0 \ 3074 -mon chardev=char0,mode=readline \ 3075 -serial chardev:char0 \ 3076 -serial chardev:char0 3077 3078 You can have more than one multiplexer in a system configuration; 3079 for instance you could have a TCP port multiplexed between UART 0 3080 and UART 1, and stdio multiplexed between the QEMU monitor and a 3081 parallel port: 3082 3083 :: 3084 3085 -chardev stdio,mux=on,id=char0 \ 3086 -mon chardev=char0,mode=readline \ 3087 -parallel chardev:char0 \ 3088 -chardev tcp,...,mux=on,id=char1 \ 3089 -serial chardev:char1 \ 3090 -serial chardev:char1 3091 3092 When you're using a multiplexed character device, some escape 3093 sequences are interpreted in the input. See :ref:`mux_005fkeys`. 3094 3095 Note that some other command line options may implicitly create 3096 multiplexed character backends; for instance ``-serial mon:stdio`` 3097 creates a multiplexed stdio backend connected to the serial port and 3098 the QEMU monitor, and ``-nographic`` also multiplexes the console 3099 and the monitor to stdio. 3100 3101 There is currently no support for multiplexing in the other 3102 direction (where a single QEMU front end takes input and output from 3103 multiple chardevs). 3104 3105 Every backend supports the ``logfile`` option, which supplies the 3106 path to a file to record all data transmitted via the backend. The 3107 ``logappend`` option controls whether the log file will be truncated 3108 or appended to when opened. 3109 3110The available backends are: 3111 3112``-chardev null,id=id`` 3113 A void device. This device will not emit any data, and will drop any 3114 data it receives. The null backend does not take any options. 3115 3116``-chardev socket,id=id[,TCP options or unix options][,server][,nowait][,telnet][,websocket][,reconnect=seconds][,tls-creds=id][,tls-authz=id]`` 3117 Create a two-way stream socket, which can be either a TCP or a unix 3118 socket. A unix socket will be created if ``path`` is specified. 3119 Behaviour is undefined if TCP options are specified for a unix 3120 socket. 3121 3122 ``server`` specifies that the socket shall be a listening socket. 3123 3124 ``nowait`` specifies that QEMU should not block waiting for a client 3125 to connect to a listening socket. 3126 3127 ``telnet`` specifies that traffic on the socket should interpret 3128 telnet escape sequences. 3129 3130 ``websocket`` specifies that the socket uses WebSocket protocol for 3131 communication. 3132 3133 ``reconnect`` sets the timeout for reconnecting on non-server 3134 sockets when the remote end goes away. qemu will delay this many 3135 seconds and then attempt to reconnect. Zero disables reconnecting, 3136 and is the default. 3137 3138 ``tls-creds`` requests enablement of the TLS protocol for 3139 encryption, and specifies the id of the TLS credentials to use for 3140 the handshake. The credentials must be previously created with the 3141 ``-object tls-creds`` argument. 3142 3143 ``tls-auth`` provides the ID of the QAuthZ authorization object 3144 against which the client's x509 distinguished name will be 3145 validated. This object is only resolved at time of use, so can be 3146 deleted and recreated on the fly while the chardev server is active. 3147 If missing, it will default to denying access. 3148 3149 TCP and unix socket options are given below: 3150 3151 ``TCP options: port=port[,host=host][,to=to][,ipv4][,ipv6][,nodelay]`` 3152 ``host`` for a listening socket specifies the local address to 3153 be bound. For a connecting socket species the remote host to 3154 connect to. ``host`` is optional for listening sockets. If not 3155 specified it defaults to ``0.0.0.0``. 3156 3157 ``port`` for a listening socket specifies the local port to be 3158 bound. For a connecting socket specifies the port on the remote 3159 host to connect to. ``port`` can be given as either a port 3160 number or a service name. ``port`` is required. 3161 3162 ``to`` is only relevant to listening sockets. If it is 3163 specified, and ``port`` cannot be bound, QEMU will attempt to 3164 bind to subsequent ports up to and including ``to`` until it 3165 succeeds. ``to`` must be specified as a port number. 3166 3167 ``ipv4`` and ``ipv6`` specify that either IPv4 or IPv6 must be 3168 used. If neither is specified the socket may use either 3169 protocol. 3170 3171 ``nodelay`` disables the Nagle algorithm. 3172 3173 ``unix options: path=path[,abstract=on|off][,tight=on|off]`` 3174 ``path`` specifies the local path of the unix socket. ``path`` 3175 is required. 3176 ``abstract`` specifies the use of the abstract socket namespace, 3177 rather than the filesystem. Optional, defaults to false. 3178 ``tight`` sets the socket length of abstract sockets to their minimum, 3179 rather than the full sun_path length. Optional, defaults to true. 3180 3181``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4][,ipv6]`` 3182 Sends all traffic from the guest to a remote host over UDP. 3183 3184 ``host`` specifies the remote host to connect to. If not specified 3185 it defaults to ``localhost``. 3186 3187 ``port`` specifies the port on the remote host to connect to. 3188 ``port`` is required. 3189 3190 ``localaddr`` specifies the local address to bind to. If not 3191 specified it defaults to ``0.0.0.0``. 3192 3193 ``localport`` specifies the local port to bind to. If not specified 3194 any available local port will be used. 3195 3196 ``ipv4`` and ``ipv6`` specify that either IPv4 or IPv6 must be used. 3197 If neither is specified the device may use either protocol. 3198 3199``-chardev msmouse,id=id`` 3200 Forward QEMU's emulated msmouse events to the guest. ``msmouse`` 3201 does not take any options. 3202 3203``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` 3204 Connect to a QEMU text console. ``vc`` may optionally be given a 3205 specific size. 3206 3207 ``width`` and ``height`` specify the width and height respectively 3208 of the console, in pixels. 3209 3210 ``cols`` and ``rows`` specify that the console be sized to fit a 3211 text console with the given dimensions. 3212 3213``-chardev ringbuf,id=id[,size=size]`` 3214 Create a ring buffer with fixed size ``size``. size must be a power 3215 of two and defaults to ``64K``. 3216 3217``-chardev file,id=id,path=path`` 3218 Log all traffic received from the guest to a file. 3219 3220 ``path`` specifies the path of the file to be opened. This file will 3221 be created if it does not already exist, and overwritten if it does. 3222 ``path`` is required. 3223 3224``-chardev pipe,id=id,path=path`` 3225 Create a two-way connection to the guest. The behaviour differs 3226 slightly between Windows hosts and other hosts: 3227 3228 On Windows, a single duplex pipe will be created at 3229 ``\\.pipe\path``. 3230 3231 On other hosts, 2 pipes will be created called ``path.in`` and 3232 ``path.out``. Data written to ``path.in`` will be received by the 3233 guest. Data written by the guest can be read from ``path.out``. QEMU 3234 will not create these fifos, and requires them to be present. 3235 3236 ``path`` forms part of the pipe path as described above. ``path`` is 3237 required. 3238 3239``-chardev console,id=id`` 3240 Send traffic from the guest to QEMU's standard output. ``console`` 3241 does not take any options. 3242 3243 ``console`` is only available on Windows hosts. 3244 3245``-chardev serial,id=id,path=path`` 3246 Send traffic from the guest to a serial device on the host. 3247 3248 On Unix hosts serial will actually accept any tty device, not only 3249 serial lines. 3250 3251 ``path`` specifies the name of the serial device to open. 3252 3253``-chardev pty,id=id`` 3254 Create a new pseudo-terminal on the host and connect to it. ``pty`` 3255 does not take any options. 3256 3257 ``pty`` is not available on Windows hosts. 3258 3259``-chardev stdio,id=id[,signal=on|off]`` 3260 Connect to standard input and standard output of the QEMU process. 3261 3262 ``signal`` controls if signals are enabled on the terminal, that 3263 includes exiting QEMU with the key sequence Control-c. This option 3264 is enabled by default, use ``signal=off`` to disable it. 3265 3266``-chardev braille,id=id`` 3267 Connect to a local BrlAPI server. ``braille`` does not take any 3268 options. 3269 3270``-chardev tty,id=id,path=path`` 3271 ``tty`` is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD 3272 and DragonFlyBSD hosts. It is an alias for ``serial``. 3273 3274 ``path`` specifies the path to the tty. ``path`` is required. 3275 3276``-chardev parallel,id=id,path=path`` 3277 \ 3278``-chardev parport,id=id,path=path`` 3279 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD 3280 hosts. 3281 3282 Connect to a local parallel port. 3283 3284 ``path`` specifies the path to the parallel port device. ``path`` is 3285 required. 3286 3287``-chardev spicevmc,id=id,debug=debug,name=name`` 3288 ``spicevmc`` is only available when spice support is built in. 3289 3290 ``debug`` debug level for spicevmc 3291 3292 ``name`` name of spice channel to connect to 3293 3294 Connect to a spice virtual machine channel, such as vdiport. 3295 3296``-chardev spiceport,id=id,debug=debug,name=name`` 3297 ``spiceport`` is only available when spice support is built in. 3298 3299 ``debug`` debug level for spicevmc 3300 3301 ``name`` name of spice port to connect to 3302 3303 Connect to a spice port, allowing a Spice client to handle the 3304 traffic identified by a name (preferably a fqdn). 3305ERST 3306 3307DEFHEADING() 3308 3309#ifdef CONFIG_TPM 3310DEFHEADING(TPM device options:) 3311 3312DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3313 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3314 " use path to provide path to a character device; default is /dev/tpm0\n" 3315 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3316 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3317 "-tpmdev emulator,id=id,chardev=dev\n" 3318 " configure the TPM device using chardev backend\n", 3319 QEMU_ARCH_ALL) 3320SRST 3321The general form of a TPM device option is: 3322 3323``-tpmdev backend,id=id[,options]`` 3324 The specific backend type will determine the applicable options. The 3325 ``-tpmdev`` option creates the TPM backend and requires a 3326 ``-device`` option that specifies the TPM frontend interface model. 3327 3328 Use ``-tpmdev help`` to print all available TPM backend types. 3329 3330The available backends are: 3331 3332``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path`` 3333 (Linux-host only) Enable access to the host's TPM using the 3334 passthrough driver. 3335 3336 ``path`` specifies the path to the host's TPM device, i.e., on a 3337 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by 3338 default ``/dev/tpm0`` is used. 3339 3340 ``cancel-path`` specifies the path to the host TPM device's sysfs 3341 entry allowing for cancellation of an ongoing TPM command. 3342 ``cancel-path`` is optional and by default QEMU will search for the 3343 sysfs entry to use. 3344 3345 Some notes about using the host's TPM with the passthrough driver: 3346 3347 The TPM device accessed by the passthrough driver must not be used 3348 by any other application on the host. 3349 3350 Since the host's firmware (BIOS/UEFI) has already initialized the 3351 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize 3352 the TPM again and may therefore not show a TPM-specific menu that 3353 would otherwise allow the user to configure the TPM, e.g., allow the 3354 user to enable/disable or activate/deactivate the TPM. Further, if 3355 TPM ownership is released from within a VM then the host's TPM will 3356 get disabled and deactivated. To enable and activate the TPM again 3357 afterwards, the host has to be rebooted and the user is required to 3358 enter the firmware's menu to enable and activate the TPM. If the TPM 3359 is left disabled and/or deactivated most TPM commands will fail. 3360 3361 To create a passthrough TPM use the following two options: 3362 3363 :: 3364 3365 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3366 3367 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by 3368 ``tpmdev=tpm0`` in the device option. 3369 3370``-tpmdev emulator,id=id,chardev=dev`` 3371 (Linux-host only) Enable access to a TPM emulator using Unix domain 3372 socket based chardev backend. 3373 3374 ``chardev`` specifies the unique ID of a character device backend 3375 that provides connection to the software TPM server. 3376 3377 To create a TPM emulator backend device with chardev socket backend: 3378 3379 :: 3380 3381 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3382ERST 3383 3384DEFHEADING() 3385 3386#endif 3387 3388DEFHEADING(Linux/Multiboot boot specific:) 3389SRST 3390When using these options, you can use a given Linux or Multiboot kernel 3391without installing it in the disk image. It can be useful for easier 3392testing of various kernels. 3393 3394 3395ERST 3396 3397DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3398 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3399SRST 3400``-kernel bzImage`` 3401 Use bzImage as kernel image. The kernel can be either a Linux kernel 3402 or in multiboot format. 3403ERST 3404 3405DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3406 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3407SRST 3408``-append cmdline`` 3409 Use cmdline as kernel command line 3410ERST 3411 3412DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3413 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3414SRST 3415``-initrd file`` 3416 Use file as initial ram disk. 3417 3418``-initrd "file1 arg=foo,file2"`` 3419 This syntax is only available with multiboot. 3420 3421 Use file1 and file2 as modules and pass arg=foo as parameter to the 3422 first module. 3423ERST 3424 3425DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3426 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3427SRST 3428``-dtb file`` 3429 Use file as a device tree binary (dtb) image and pass it to the 3430 kernel on boot. 3431ERST 3432 3433DEFHEADING() 3434 3435DEFHEADING(Debug/Expert options:) 3436 3437DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3438 "-fw_cfg [name=]<name>,file=<file>\n" 3439 " add named fw_cfg entry with contents from file\n" 3440 "-fw_cfg [name=]<name>,string=<str>\n" 3441 " add named fw_cfg entry with contents from string\n", 3442 QEMU_ARCH_ALL) 3443SRST 3444``-fw_cfg [name=]name,file=file`` 3445 Add named fw\_cfg entry with contents from file file. 3446 3447``-fw_cfg [name=]name,string=str`` 3448 Add named fw\_cfg entry with contents from string str. 3449 3450 The terminating NUL character of the contents of str will not be 3451 included as part of the fw\_cfg item data. To insert contents with 3452 embedded NUL characters, you have to use the file parameter. 3453 3454 The fw\_cfg entries are passed by QEMU through to the guest. 3455 3456 Example: 3457 3458 :: 3459 3460 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3461 3462 creates an fw\_cfg entry named opt/com.mycompany/blob with contents 3463 from ./my\_blob.bin. 3464ERST 3465 3466DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3467 "-serial dev redirect the serial port to char device 'dev'\n", 3468 QEMU_ARCH_ALL) 3469SRST 3470``-serial dev`` 3471 Redirect the virtual serial port to host character device dev. The 3472 default device is ``vc`` in graphical mode and ``stdio`` in non 3473 graphical mode. 3474 3475 This option can be used several times to simulate up to 4 serial 3476 ports. 3477 3478 Use ``-serial none`` to disable all serial ports. 3479 3480 Available character devices are: 3481 3482 ``vc[:WxH]`` 3483 Virtual console. Optionally, a width and height can be given in 3484 pixel with 3485 3486 :: 3487 3488 vc:800x600 3489 3490 It is also possible to specify width or height in characters: 3491 3492 :: 3493 3494 vc:80Cx24C 3495 3496 ``pty`` 3497 [Linux only] Pseudo TTY (a new PTY is automatically allocated) 3498 3499 ``none`` 3500 No device is allocated. 3501 3502 ``null`` 3503 void device 3504 3505 ``chardev:id`` 3506 Use a named character device defined with the ``-chardev`` 3507 option. 3508 3509 ``/dev/XXX`` 3510 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial 3511 port parameters are set according to the emulated ones. 3512 3513 ``/dev/parportN`` 3514 [Linux only, parallel port only] Use host parallel port N. 3515 Currently SPP and EPP parallel port features can be used. 3516 3517 ``file:filename`` 3518 Write output to filename. No character can be read. 3519 3520 ``stdio`` 3521 [Unix only] standard input/output 3522 3523 ``pipe:filename`` 3524 name pipe filename 3525 3526 ``COMn`` 3527 [Windows only] Use host serial port n 3528 3529 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]`` 3530 This implements UDP Net Console. When remote\_host or src\_ip 3531 are not specified they default to ``0.0.0.0``. When not using a 3532 specified src\_port a random port is automatically chosen. 3533 3534 If you just want a simple readonly console you can use 3535 ``netcat`` or ``nc``, by starting QEMU with: 3536 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time 3537 QEMU writes something to that port it will appear in the 3538 netconsole session. 3539 3540 If you plan to send characters back via netconsole or you want 3541 to stop and start QEMU a lot of times, you should have QEMU use 3542 the same source port each time by using something like ``-serial 3543 udp::4555@:4556`` to QEMU. Another approach is to use a patched 3544 version of netcat which can listen to a TCP port and send and 3545 receive characters via udp. If you have a patched version of 3546 netcat which activates telnet remote echo and single char 3547 transfer, then you can use the following options to set up a 3548 netcat redirector to allow telnet on port 5555 to access the 3549 QEMU port. 3550 3551 ``QEMU Options:`` 3552 -serial udp::4555@:4556 3553 3554 ``netcat options:`` 3555 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3556 3557 ``telnet options:`` 3558 localhost 5555 3559 3560 ``tcp:[host]:port[,server][,nowait][,nodelay][,reconnect=seconds]`` 3561 The TCP Net Console has two modes of operation. It can send the 3562 serial I/O to a location or wait for a connection from a 3563 location. By default the TCP Net Console is sent to host at the 3564 port. If you use the server option QEMU will wait for a client 3565 socket application to connect to the port before continuing, 3566 unless the ``nowait`` option was specified. The ``nodelay`` 3567 option disables the Nagle buffering algorithm. The ``reconnect`` 3568 option only applies if noserver is set, if the connection goes 3569 down it will attempt to reconnect at the given interval. If host 3570 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a 3571 time is accepted. You can use ``telnet`` to connect to the 3572 corresponding character device. 3573 3574 ``Example to send tcp console to 192.168.0.2 port 4444`` 3575 -serial tcp:192.168.0.2:4444 3576 3577 ``Example to listen and wait on port 4444 for connection`` 3578 -serial tcp::4444,server 3579 3580 ``Example to not wait and listen on ip 192.168.0.100 port 4444`` 3581 -serial tcp:192.168.0.100:4444,server,nowait 3582 3583 ``telnet:host:port[,server][,nowait][,nodelay]`` 3584 The telnet protocol is used instead of raw tcp sockets. The 3585 options work the same as if you had specified ``-serial tcp``. 3586 The difference is that the port acts like a telnet server or 3587 client using telnet option negotiation. This will also allow you 3588 to send the MAGIC\_SYSRQ sequence if you use a telnet that 3589 supports sending the break sequence. Typically in unix telnet 3590 you do it with Control-] and then type "send break" followed by 3591 pressing the enter key. 3592 3593 ``websocket:host:port,server[,nowait][,nodelay]`` 3594 The WebSocket protocol is used instead of raw tcp socket. The 3595 port acts as a WebSocket server. Client mode is not supported. 3596 3597 ``unix:path[,server][,nowait][,reconnect=seconds]`` 3598 A unix domain socket is used instead of a tcp socket. The option 3599 works the same as if you had specified ``-serial tcp`` except 3600 the unix domain socket path is used for connections. 3601 3602 ``mon:dev_string`` 3603 This is a special option to allow the monitor to be multiplexed 3604 onto another serial port. The monitor is accessed with key 3605 sequence of Control-a and then pressing c. dev\_string should be 3606 any one of the serial devices specified above. An example to 3607 multiplex the monitor onto a telnet server listening on port 3608 4444 would be: 3609 3610 ``-serial mon:telnet::4444,server,nowait`` 3611 3612 When the monitor is multiplexed to stdio in this way, Ctrl+C 3613 will not terminate QEMU any more but will be passed to the guest 3614 instead. 3615 3616 ``braille`` 3617 Braille device. This will use BrlAPI to display the braille 3618 output on a real or fake device. 3619 3620 ``msmouse`` 3621 Three button serial mouse. Configure the guest to use Microsoft 3622 protocol. 3623ERST 3624 3625DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3626 "-parallel dev redirect the parallel port to char device 'dev'\n", 3627 QEMU_ARCH_ALL) 3628SRST 3629``-parallel dev`` 3630 Redirect the virtual parallel port to host device dev (same devices 3631 as the serial port). On Linux hosts, ``/dev/parportN`` can be used 3632 to use hardware devices connected on the corresponding host parallel 3633 port. 3634 3635 This option can be used several times to simulate up to 3 parallel 3636 ports. 3637 3638 Use ``-parallel none`` to disable all parallel ports. 3639ERST 3640 3641DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3642 "-monitor dev redirect the monitor to char device 'dev'\n", 3643 QEMU_ARCH_ALL) 3644SRST 3645``-monitor dev`` 3646 Redirect the monitor to host device dev (same devices as the serial 3647 port). The default device is ``vc`` in graphical mode and ``stdio`` 3648 in non graphical mode. Use ``-monitor none`` to disable the default 3649 monitor. 3650ERST 3651DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3652 "-qmp dev like -monitor but opens in 'control' mode\n", 3653 QEMU_ARCH_ALL) 3654SRST 3655``-qmp dev`` 3656 Like -monitor but opens in 'control' mode. 3657ERST 3658DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3659 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3660 QEMU_ARCH_ALL) 3661SRST 3662``-qmp-pretty dev`` 3663 Like -qmp but uses pretty JSON formatting. 3664ERST 3665 3666DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3667 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3668SRST 3669``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]`` 3670 Setup monitor on chardev name. ``pretty`` turns on JSON pretty 3671 printing easing human reading and debugging. 3672ERST 3673 3674DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3675 "-debugcon dev redirect the debug console to char device 'dev'\n", 3676 QEMU_ARCH_ALL) 3677SRST 3678``-debugcon dev`` 3679 Redirect the debug console to host device dev (same devices as the 3680 serial port). The debug console is an I/O port which is typically 3681 port 0xe9; writing to that I/O port sends output to this device. The 3682 default device is ``vc`` in graphical mode and ``stdio`` in non 3683 graphical mode. 3684ERST 3685 3686DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3687 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3688SRST 3689``-pidfile file`` 3690 Store the QEMU process PID in file. It is useful if you launch QEMU 3691 from a script. 3692ERST 3693 3694DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3695 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3696SRST 3697``-singlestep`` 3698 Run the emulation in single step mode. 3699ERST 3700 3701DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3702 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3703 QEMU_ARCH_ALL) 3704SRST 3705``--preconfig`` 3706 Pause QEMU for interactive configuration before the machine is 3707 created, which allows querying and configuring properties that will 3708 affect machine initialization. Use QMP command 'x-exit-preconfig' to 3709 exit the preconfig state and move to the next state (i.e. run guest 3710 if -S isn't used or pause the second time if -S is used). This 3711 option is experimental. 3712ERST 3713 3714DEF("S", 0, QEMU_OPTION_S, \ 3715 "-S freeze CPU at startup (use 'c' to start execution)\n", 3716 QEMU_ARCH_ALL) 3717SRST 3718``-S`` 3719 Do not start CPU at startup (you must type 'c' in the monitor). 3720ERST 3721 3722DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3723 "-realtime [mlock=on|off]\n" 3724 " run qemu with realtime features\n" 3725 " mlock=on|off controls mlock support (default: on)\n", 3726 QEMU_ARCH_ALL) 3727SRST 3728``-realtime mlock=on|off`` 3729 Run qemu with realtime features. mlocking qemu and guest memory can 3730 be enabled via ``mlock=on`` (enabled by default). 3731ERST 3732 3733DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3734 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3735 " run qemu with overcommit hints\n" 3736 " mem-lock=on|off controls memory lock support (default: off)\n" 3737 " cpu-pm=on|off controls cpu power management (default: off)\n", 3738 QEMU_ARCH_ALL) 3739SRST 3740``-overcommit mem-lock=on|off`` 3741 \ 3742``-overcommit cpu-pm=on|off`` 3743 Run qemu with hints about host resource overcommit. The default is 3744 to assume that host overcommits all resources. 3745 3746 Locking qemu and guest memory can be enabled via ``mem-lock=on`` 3747 (disabled by default). This works when host memory is not 3748 overcommitted and reduces the worst-case latency for guest. This is 3749 equivalent to ``realtime``. 3750 3751 Guest ability to manage power state of host cpus (increasing latency 3752 for other processes on the same host cpu, but decreasing latency for 3753 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This 3754 works best when host CPU is not overcommitted. When used, host 3755 estimates of CPU cycle and power utilization will be incorrect, not 3756 taking into account guest idle time. 3757ERST 3758 3759DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3760 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n" 3761 " the guest without waiting for gdb to connect; use -S too\n" 3762 " if you want it to not start execution.)\n", 3763 QEMU_ARCH_ALL) 3764SRST 3765``-gdb dev`` 3766 Accept a gdb connection on device dev (see 3767 :ref:`gdb_005fusage`). Note that this option does not pause QEMU 3768 execution -- if you want QEMU to not start the guest until you 3769 connect with gdb and issue a ``continue`` command, you will need to 3770 also pass the ``-S`` option to QEMU. 3771 3772 The most usual configuration is to listen on a local TCP socket:: 3773 3774 -gdb tcp::3117 3775 3776 but you can specify other backends; UDP, pseudo TTY, or even stdio 3777 are all reasonable use cases. For example, a stdio connection 3778 allows you to start QEMU from within gdb and establish the 3779 connection via a pipe: 3780 3781 .. parsed-literal:: 3782 3783 (gdb) target remote | exec |qemu_system| -gdb stdio ... 3784ERST 3785 3786DEF("s", 0, QEMU_OPTION_s, \ 3787 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3788 QEMU_ARCH_ALL) 3789SRST 3790``-s`` 3791 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3792 (see :ref:`gdb_005fusage`). 3793ERST 3794 3795DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3796 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3797 QEMU_ARCH_ALL) 3798SRST 3799``-d item1[,...]`` 3800 Enable logging of specified items. Use '-d help' for a list of log 3801 items. 3802ERST 3803 3804DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3805 "-D logfile output log to logfile (default stderr)\n", 3806 QEMU_ARCH_ALL) 3807SRST 3808``-D logfile`` 3809 Output log in logfile instead of to stderr 3810ERST 3811 3812DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3813 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3814 QEMU_ARCH_ALL) 3815SRST 3816``-dfilter range1[,...]`` 3817 Filter debug output to that relevant to a range of target addresses. 3818 The filter spec can be either start+size, start-size or start..end 3819 where start end and size are the addresses and sizes required. For 3820 example: 3821 3822 :: 3823 3824 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3825 3826 Will dump output for any code in the 0x1000 sized block starting at 3827 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and 3828 another 0x1000 sized block starting at 0xffffffc00005f000. 3829ERST 3830 3831DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3832 "-seed number seed the pseudo-random number generator\n", 3833 QEMU_ARCH_ALL) 3834SRST 3835``-seed number`` 3836 Force the guest to use a deterministic pseudo-random number 3837 generator, seeded with number. This does not affect crypto routines 3838 within the host. 3839ERST 3840 3841DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3842 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3843 QEMU_ARCH_ALL) 3844SRST 3845``-L path`` 3846 Set the directory for the BIOS, VGA BIOS and keymaps. 3847 3848 To list all the data directories, use ``-L help``. 3849ERST 3850 3851DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3852 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3853SRST 3854``-bios file`` 3855 Set the filename for the BIOS. 3856ERST 3857 3858DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3859 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3860SRST 3861``-enable-kvm`` 3862 Enable KVM full virtualization support. This option is only 3863 available if KVM support is enabled when compiling. 3864ERST 3865 3866DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3867 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3868DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3869 "-xen-attach attach to existing xen domain\n" 3870 " libxl will use this when starting QEMU\n", 3871 QEMU_ARCH_ALL) 3872DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3873 "-xen-domid-restrict restrict set of available xen operations\n" 3874 " to specified domain id. (Does not affect\n" 3875 " xenpv machine type).\n", 3876 QEMU_ARCH_ALL) 3877SRST 3878``-xen-domid id`` 3879 Specify xen guest domain id (XEN only). 3880 3881``-xen-attach`` 3882 Attach to existing xen domain. libxl will use this when starting 3883 QEMU (XEN only). Restrict set of available xen operations to 3884 specified domain id (XEN only). 3885ERST 3886 3887DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3888 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3889SRST 3890``-no-reboot`` 3891 Exit instead of rebooting. 3892ERST 3893 3894DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3895 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3896SRST 3897``-no-shutdown`` 3898 Don't exit QEMU on guest shutdown, but instead only stop the 3899 emulation. This allows for instance switching to monitor to commit 3900 changes to the disk image. 3901ERST 3902 3903DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3904 "-loadvm [tag|id]\n" \ 3905 " start right away with a saved state (loadvm in monitor)\n", 3906 QEMU_ARCH_ALL) 3907SRST 3908``-loadvm file`` 3909 Start right away with a saved state (``loadvm`` in monitor) 3910ERST 3911 3912#ifndef _WIN32 3913DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3914 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3915#endif 3916SRST 3917``-daemonize`` 3918 Daemonize the QEMU process after initialization. QEMU will not 3919 detach from standard IO until it is ready to receive connections on 3920 any of its devices. This option is a useful way for external 3921 programs to launch QEMU without having to cope with initialization 3922 race conditions. 3923ERST 3924 3925DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3926 "-option-rom rom load a file, rom, into the option ROM space\n", 3927 QEMU_ARCH_ALL) 3928SRST 3929``-option-rom file`` 3930 Load the contents of file as an option ROM. This option is useful to 3931 load things like EtherBoot. 3932ERST 3933 3934DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3935 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3936 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3937 QEMU_ARCH_ALL) 3938 3939SRST 3940``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]`` 3941 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at 3942 the current UTC or local time, respectively. ``localtime`` is 3943 required for correct date in MS-DOS or Windows. To start at a 3944 specific point in time, provide datetime in the format 3945 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC. 3946 3947 By default the RTC is driven by the host system time. This allows 3948 using of the RTC as accurate reference clock inside the guest, 3949 specifically if the host time is smoothly following an accurate 3950 external reference clock, e.g. via NTP. If you want to isolate the 3951 guest time from the host, you can set ``clock`` to ``rt`` instead, 3952 which provides a host monotonic clock if host support it. To even 3953 prevent the RTC from progressing during suspension, you can set 3954 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is 3955 recommended especially in icount mode in order to preserve 3956 determinism; however, note that in icount mode the speed of the 3957 virtual clock is variable and can in general differ from the host 3958 clock. 3959 3960 Enable ``driftfix`` (i386 targets only) if you experience time drift 3961 problems, specifically with Windows' ACPI HAL. This option will try 3962 to figure out how many timer interrupts were not processed by the 3963 Windows guest and will re-inject them. 3964ERST 3965 3966DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3967 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3968 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3969 " instruction, enable aligning the host and virtual clocks\n" \ 3970 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3971SRST 3972``-icount [shift=N|auto][,rr=record|replay,rrfile=filename,rrsnapshot=snapshot]`` 3973 Enable virtual instruction counter. The virtual cpu will execute one 3974 instruction every 2^N ns of virtual time. If ``auto`` is specified 3975 then the virtual cpu speed will be automatically adjusted to keep 3976 virtual time within a few seconds of real time. 3977 3978 When the virtual cpu is sleeping, the virtual time will advance at 3979 default speed unless ``sleep=on|off`` is specified. With 3980 ``sleep=on|off``, the virtual time will jump to the next timer 3981 deadline instantly whenever the virtual cpu goes to sleep mode and 3982 will not advance if no timer is enabled. This behavior give 3983 deterministic execution times from the guest point of view. 3984 3985 Note that while this option can give deterministic behavior, it does 3986 not provide cycle accurate emulation. Modern CPUs contain 3987 superscalar out of order cores with complex cache hierarchies. The 3988 number of instructions executed often has little or no correlation 3989 with actual performance. 3990 3991 ``align=on`` will activate the delay algorithm which will try to 3992 synchronise the host clock and the virtual clock. The goal is to 3993 have a guest running at the real frequency imposed by the shift 3994 option. Whenever the guest clock is behind the host clock and if 3995 ``align=on`` is specified then we print a message to the user to 3996 inform about the delay. Currently this option does not work when 3997 ``shift`` is ``auto``. Note: The sync algorithm will work for those 3998 shift values for which the guest clock runs ahead of the host clock. 3999 Typically this happens when the shift value is high (how high 4000 depends on the host machine). 4001 4002 When ``rr`` option is specified deterministic record/replay is 4003 enabled. Replay log is written into filename file in record mode and 4004 read from this file in replay mode. 4005 4006 Option rrsnapshot is used to create new vm snapshot named snapshot 4007 at the start of execution recording. In replay mode this option is 4008 used to load the initial VM state. 4009ERST 4010 4011DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 4012 "-watchdog model\n" \ 4013 " enable virtual hardware watchdog [default=none]\n", 4014 QEMU_ARCH_ALL) 4015SRST 4016``-watchdog model`` 4017 Create a virtual hardware watchdog device. Once enabled (by a guest 4018 action), the watchdog must be periodically polled by an agent inside 4019 the guest or else the guest will be restarted. Choose a model for 4020 which your guest has drivers. 4021 4022 The model is the model of hardware watchdog to emulate. Use 4023 ``-watchdog help`` to list available hardware models. Only one 4024 watchdog can be enabled for a guest. 4025 4026 The following models may be available: 4027 4028 ``ib700`` 4029 iBASE 700 is a very simple ISA watchdog with a single timer. 4030 4031 ``i6300esb`` 4032 Intel 6300ESB I/O controller hub is a much more featureful 4033 PCI-based dual-timer watchdog. 4034 4035 ``diag288`` 4036 A virtual watchdog for s390x backed by the diagnose 288 4037 hypercall (currently KVM only). 4038ERST 4039 4040DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 4041 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 4042 " action when watchdog fires [default=reset]\n", 4043 QEMU_ARCH_ALL) 4044SRST 4045``-watchdog-action action`` 4046 The action controls what QEMU will do when the watchdog timer 4047 expires. The default is ``reset`` (forcefully reset the guest). 4048 Other possible actions are: ``shutdown`` (attempt to gracefully 4049 shutdown the guest), ``poweroff`` (forcefully poweroff the guest), 4050 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the 4051 guest), ``debug`` (print a debug message and continue), or ``none`` 4052 (do nothing). 4053 4054 Note that the ``shutdown`` action requires that the guest responds 4055 to ACPI signals, which it may not be able to do in the sort of 4056 situations where the watchdog would have expired, and thus 4057 ``-watchdog-action shutdown`` is not recommended for production use. 4058 4059 Examples: 4060 4061 ``-watchdog i6300esb -watchdog-action pause``; \ ``-watchdog ib700`` 4062 4063ERST 4064 4065DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 4066 "-echr chr set terminal escape character instead of ctrl-a\n", 4067 QEMU_ARCH_ALL) 4068SRST 4069``-echr numeric_ascii_value`` 4070 Change the escape character used for switching to the monitor when 4071 using monitor and serial sharing. The default is ``0x01`` when using 4072 the ``-nographic`` option. ``0x01`` is equal to pressing 4073 ``Control-a``. You can select a different character from the ascii 4074 control keys where 1 through 26 map to Control-a through Control-z. 4075 For instance you could use the either of the following to change the 4076 escape character to Control-t. 4077 4078 ``-echr 0x14``; \ ``-echr 20`` 4079 4080ERST 4081 4082DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 4083 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 4084SRST 4085``-show-cursor`` 4086 Show cursor. 4087ERST 4088 4089DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 4090 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 4091SRST 4092``-tb-size n`` 4093 Set TCG translation block cache size. Deprecated, use 4094 '\ ``-accel tcg,tb-size=n``\ ' instead. 4095ERST 4096 4097DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4098 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 4099 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 4100 "-incoming unix:socketpath\n" \ 4101 " prepare for incoming migration, listen on\n" \ 4102 " specified protocol and socket address\n" \ 4103 "-incoming fd:fd\n" \ 4104 "-incoming exec:cmdline\n" \ 4105 " accept incoming migration on given file descriptor\n" \ 4106 " or from given external command\n" \ 4107 "-incoming defer\n" \ 4108 " wait for the URI to be specified via migrate_incoming\n", 4109 QEMU_ARCH_ALL) 4110SRST 4111``-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]`` 4112 \ 4113``-incoming rdma:host:port[,ipv4][,ipv6]`` 4114 Prepare for incoming migration, listen on a given tcp port. 4115 4116``-incoming unix:socketpath`` 4117 Prepare for incoming migration, listen on a given unix socket. 4118 4119``-incoming fd:fd`` 4120 Accept incoming migration from a given filedescriptor. 4121 4122``-incoming exec:cmdline`` 4123 Accept incoming migration as an output from specified external 4124 command. 4125 4126``-incoming defer`` 4127 Wait for the URI to be specified via migrate\_incoming. The monitor 4128 can be used to change settings (such as migration parameters) prior 4129 to issuing the migrate\_incoming to allow the migration to begin. 4130ERST 4131 4132DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4133 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4134SRST 4135``-only-migratable`` 4136 Only allow migratable devices. Devices will not be allowed to enter 4137 an unmigratable state. 4138ERST 4139 4140DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4141 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4142SRST 4143``-nodefaults`` 4144 Don't create default devices. Normally, QEMU sets the default 4145 devices like serial port, parallel port, virtual console, monitor 4146 device, VGA adapter, floppy and CD-ROM drive and others. The 4147 ``-nodefaults`` option will disable all those default devices. 4148ERST 4149 4150#ifndef _WIN32 4151DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4152 "-chroot dir chroot to dir just before starting the VM\n", 4153 QEMU_ARCH_ALL) 4154#endif 4155SRST 4156``-chroot dir`` 4157 Immediately before starting guest execution, chroot to the specified 4158 directory. Especially useful in combination with -runas. 4159ERST 4160 4161#ifndef _WIN32 4162DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4163 "-runas user change to user id user just before starting the VM\n" \ 4164 " user can be numeric uid:gid instead\n", 4165 QEMU_ARCH_ALL) 4166#endif 4167SRST 4168``-runas user`` 4169 Immediately before starting guest execution, drop root privileges, 4170 switching to the specified user. 4171ERST 4172 4173DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4174 "-prom-env variable=value\n" 4175 " set OpenBIOS nvram variables\n", 4176 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4177SRST 4178``-prom-env variable=value`` 4179 Set OpenBIOS nvram variable to given value (PPC, SPARC only). 4180 4181 :: 4182 4183 qemu-system-sparc -prom-env 'auto-boot?=false' \ 4184 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' 4185 4186 :: 4187 4188 qemu-system-ppc -prom-env 'auto-boot?=false' \ 4189 -prom-env 'boot-device=hd:2,\yaboot' \ 4190 -prom-env 'boot-args=conf=hd:2,\yaboot.conf' 4191ERST 4192DEF("semihosting", 0, QEMU_OPTION_semihosting, 4193 "-semihosting semihosting mode\n", 4194 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4195 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4196SRST 4197``-semihosting`` 4198 Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4199 4200 Note that this allows guest direct access to the host filesystem, so 4201 should only be used with a trusted guest OS. 4202 4203 See the -semihosting-config option documentation for further 4204 information about the facilities this enables. 4205ERST 4206DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4207 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4208 " semihosting configuration\n", 4209QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4210QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4211SRST 4212``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]`` 4213 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II 4214 only). 4215 4216 Note that this allows guest direct access to the host filesystem, so 4217 should only be used with a trusted guest OS. 4218 4219 On Arm this implements the standard semihosting API, version 2.0. 4220 4221 On M68K this implements the "ColdFire GDB" interface used by 4222 libgloss. 4223 4224 Xtensa semihosting provides basic file IO calls, such as 4225 open/read/write/seek/select. Tensilica baremetal libc for ISS and 4226 linux platform "sim" use this interface. 4227 4228 ``target=native|gdb|auto`` 4229 Defines where the semihosting calls will be addressed, to QEMU 4230 (``native``) or to GDB (``gdb``). The default is ``auto``, which 4231 means ``gdb`` during debug sessions and ``native`` otherwise. 4232 4233 ``chardev=str1`` 4234 Send the output to a chardev backend output for native or auto 4235 output when not in gdb 4236 4237 ``arg=str1,arg=str2,...`` 4238 Allows the user to pass input arguments, and can be used 4239 multiple times to build up a list. The old-style 4240 ``-kernel``/``-append`` method of passing a command line is 4241 still supported for backward compatibility. If both the 4242 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are 4243 specified, the former is passed to semihosting as it always 4244 takes precedence. 4245ERST 4246DEF("old-param", 0, QEMU_OPTION_old_param, 4247 "-old-param old param mode\n", QEMU_ARCH_ARM) 4248SRST 4249``-old-param`` 4250 Old param mode (ARM only). 4251ERST 4252 4253DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4254 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4255 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4256 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4257 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4258 " by the kernel, but typically no longer used by modern\n" \ 4259 " C library implementations.\n" \ 4260 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4261 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4262 " The value 'children' will deny set*uid|gid system calls for\n" \ 4263 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4264 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4265 " blacklisting *fork and execve\n" \ 4266 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4267 QEMU_ARCH_ALL) 4268SRST 4269``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]`` 4270 Enable Seccomp mode 2 system call filter. 'on' will enable syscall 4271 filtering and 'off' will disable it. The default is 'off'. 4272 4273 ``obsolete=string`` 4274 Enable Obsolete system calls 4275 4276 ``elevateprivileges=string`` 4277 Disable set\*uid\|gid system calls 4278 4279 ``spawn=string`` 4280 Disable \*fork and execve 4281 4282 ``resourcecontrol=string`` 4283 Disable process affinity and schedular priority 4284ERST 4285 4286DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4287 "-readconfig <file>\n", QEMU_ARCH_ALL) 4288SRST 4289``-readconfig file`` 4290 Read device configuration from file. This approach is useful when 4291 you want to spawn QEMU process with many command line options but 4292 you don't want to exceed the command line character limit. 4293ERST 4294DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4295 "-writeconfig <file>\n" 4296 " read/write config file\n", QEMU_ARCH_ALL) 4297SRST 4298``-writeconfig file`` 4299 Write device configuration to file. The file can be either filename 4300 to save command line and device configuration into file or dash 4301 ``-``) character to print the output to stdout. This can be later 4302 used as input file for ``-readconfig`` option. 4303ERST 4304 4305DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4306 "-no-user-config\n" 4307 " do not load default user-provided config files at startup\n", 4308 QEMU_ARCH_ALL) 4309SRST 4310``-no-user-config`` 4311 The ``-no-user-config`` option makes QEMU not load any of the 4312 user-provided config files on sysconfdir. 4313ERST 4314 4315DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4316 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4317 " specify tracing options\n", 4318 QEMU_ARCH_ALL) 4319SRST 4320``-trace [[enable=]pattern][,events=file][,file=file]`` 4321 .. include:: ../qemu-option-trace.rst.inc 4322 4323ERST 4324DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4325 "-plugin [file=]<file>[,arg=<string>]\n" 4326 " load a plugin\n", 4327 QEMU_ARCH_ALL) 4328SRST 4329``-plugin file=file[,arg=string]`` 4330 Load a plugin. 4331 4332 ``file=file`` 4333 Load the given plugin from a shared library file. 4334 4335 ``arg=string`` 4336 Argument string passed to the plugin. (Can be given multiple 4337 times.) 4338ERST 4339 4340HXCOMM Internal use 4341DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4342DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4343 4344#ifdef __linux__ 4345DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4346 "-enable-fips enable FIPS 140-2 compliance\n", 4347 QEMU_ARCH_ALL) 4348#endif 4349SRST 4350``-enable-fips`` 4351 Enable FIPS 140-2 compliance mode. 4352ERST 4353 4354HXCOMM Deprecated by -accel tcg 4355DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4356 4357DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4358 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n" 4359 " control error message format\n" 4360 " timestamp=on enables timestamps (default: off)\n" 4361 " guest-name=on enables guest name prefix but only if\n" 4362 " -name guest option is set (default: off)\n", 4363 QEMU_ARCH_ALL) 4364SRST 4365``-msg [timestamp[=on|off]][,guest-name[=on|off]]`` 4366 Control error message format. 4367 4368 ``timestamp=on|off`` 4369 Prefix messages with a timestamp. Default is off. 4370 4371 ``guest-name=on|off`` 4372 Prefix messages with guest name but only if -name guest option is set 4373 otherwise the option is ignored. Default is off. 4374ERST 4375 4376DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4377 "-dump-vmstate <file>\n" 4378 " Output vmstate information in JSON format to file.\n" 4379 " Use the scripts/vmstate-static-checker.py file to\n" 4380 " check for possible regressions in migration code\n" 4381 " by comparing two such vmstate dumps.\n", 4382 QEMU_ARCH_ALL) 4383SRST 4384``-dump-vmstate file`` 4385 Dump json-encoded vmstate information for current machine type to 4386 file in file 4387ERST 4388 4389DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4390 "-enable-sync-profile\n" 4391 " enable synchronization profiling\n", 4392 QEMU_ARCH_ALL) 4393SRST 4394``-enable-sync-profile`` 4395 Enable synchronization profiling. 4396ERST 4397 4398DEFHEADING() 4399 4400DEFHEADING(Generic object creation:) 4401 4402DEF("object", HAS_ARG, QEMU_OPTION_object, 4403 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4404 " create a new object of type TYPENAME setting properties\n" 4405 " in the order they are specified. Note that the 'id'\n" 4406 " property must be set. These objects are placed in the\n" 4407 " '/objects' path.\n", 4408 QEMU_ARCH_ALL) 4409SRST 4410``-object typename[,prop1=value1,...]`` 4411 Create a new object of type typename setting properties in the order 4412 they are specified. Note that the 'id' property must be set. These 4413 objects are placed in the '/objects' path. 4414 4415 ``-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`` 4416 Creates a memory file backend object, which can be used to back 4417 the guest RAM with huge pages. 4418 4419 The ``id`` parameter is a unique ID that will be used to 4420 reference this memory region when configuring the ``-numa`` 4421 argument. 4422 4423 The ``size`` option provides the size of the memory region, and 4424 accepts common suffixes, eg ``500M``. 4425 4426 The ``mem-path`` provides the path to either a shared memory or 4427 huge page filesystem mount. 4428 4429 The ``share`` boolean option determines whether the memory 4430 region is marked as private to QEMU, or shared. The latter 4431 allows a co-operating external process to access the QEMU memory 4432 region. 4433 4434 The ``share`` is also required for pvrdma devices due to 4435 limitations in the RDMA API provided by Linux. 4436 4437 Setting share=on might affect the ability to configure NUMA 4438 bindings for the memory backend under some circumstances, see 4439 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel 4440 source tree for additional details. 4441 4442 Setting the ``discard-data`` boolean option to on indicates that 4443 file contents can be destroyed when QEMU exits, to avoid 4444 unnecessarily flushing data to the backing file. Note that 4445 ``discard-data`` is only an optimization, and QEMU might not 4446 discard file contents if it aborts unexpectedly or is terminated 4447 using SIGKILL. 4448 4449 The ``merge`` boolean option enables memory merge, also known as 4450 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider 4451 the pages for memory deduplication. 4452 4453 Setting the ``dump`` boolean option to off excludes the memory 4454 from core dumps. This feature is also known as MADV\_DONTDUMP. 4455 4456 The ``prealloc`` boolean option enables memory preallocation. 4457 4458 The ``host-nodes`` option binds the memory range to a list of 4459 NUMA host nodes. 4460 4461 The ``policy`` option sets the NUMA policy to one of the 4462 following values: 4463 4464 ``default`` 4465 default host policy 4466 4467 ``preferred`` 4468 prefer the given host node list for allocation 4469 4470 ``bind`` 4471 restrict memory allocation to the given host node list 4472 4473 ``interleave`` 4474 interleave memory allocations across the given host node 4475 list 4476 4477 The ``align`` option specifies the base address alignment when 4478 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg 4479 ``2M``. Some backend store specified by ``mem-path`` requires an 4480 alignment different than the default one used by QEMU, eg the 4481 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4482 such cases, users can specify the required alignment via this 4483 option. 4484 4485 The ``pmem`` option specifies whether the backing file specified 4486 by ``mem-path`` is in host persistent memory that can be 4487 accessed using the SNIA NVM programming model (e.g. Intel 4488 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary 4489 operations to guarantee the persistence of its own writes to 4490 ``mem-path`` (e.g. in vNVDIMM label emulation and live 4491 migration). Also, we will map the backend-file with MAP\_SYNC 4492 flag, which ensures the file metadata is in sync for 4493 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC 4494 requires support from both the host kernel (since Linux kernel 4495 4.15) and the filesystem of ``mem-path`` mounted with DAX 4496 option. 4497 4498 ``-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`` 4499 Creates a memory backend object, which can be used to back the 4500 guest RAM. Memory backend objects offer more control than the 4501 ``-m`` option that is traditionally used to define guest RAM. 4502 Please refer to ``memory-backend-file`` for a description of the 4503 options. 4504 4505 ``-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`` 4506 Creates an anonymous memory file backend object, which allows 4507 QEMU to share the memory with an external process (e.g. when 4508 using vhost-user). The memory is allocated with memfd and 4509 optional sealing. (Linux only) 4510 4511 The ``seal`` option creates a sealed-file, that will block 4512 further resizing the memory ('on' by default). 4513 4514 The ``hugetlb`` option specify the file to be created resides in 4515 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction 4516 with the ``hugetlb`` option, the ``hugetlbsize`` option specify 4517 the hugetlb page size on systems that support multiple hugetlb 4518 page sizes (it must be a power of 2 value supported by the 4519 system). 4520 4521 In some versions of Linux, the ``hugetlb`` option is 4522 incompatible with the ``seal`` option (requires at least Linux 4523 4.16). 4524 4525 Please refer to ``memory-backend-file`` for a description of the 4526 other options. 4527 4528 The ``share`` boolean option is on by default with memfd. 4529 4530 ``-object rng-builtin,id=id`` 4531 Creates a random number generator backend which obtains entropy 4532 from QEMU builtin functions. The ``id`` parameter is a unique ID 4533 that will be used to reference this entropy backend from the 4534 ``virtio-rng`` device. By default, the ``virtio-rng`` device 4535 uses this RNG backend. 4536 4537 ``-object rng-random,id=id,filename=/dev/random`` 4538 Creates a random number generator backend which obtains entropy 4539 from a device on the host. The ``id`` parameter is a unique ID 4540 that will be used to reference this entropy backend from the 4541 ``virtio-rng`` device. The ``filename`` parameter specifies 4542 which file to obtain entropy from and if omitted defaults to 4543 ``/dev/urandom``. 4544 4545 ``-object rng-egd,id=id,chardev=chardevid`` 4546 Creates a random number generator backend which obtains entropy 4547 from an external daemon running on the host. The ``id`` 4548 parameter is a unique ID that will be used to reference this 4549 entropy backend from the ``virtio-rng`` device. The ``chardev`` 4550 parameter is the unique ID of a character device backend that 4551 provides the connection to the RNG daemon. 4552 4553 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off`` 4554 Creates a TLS anonymous credentials object, which can be used to 4555 provide TLS support on network backends. The ``id`` parameter is 4556 a unique ID which network backends will use to access the 4557 credentials. The ``endpoint`` is either ``server`` or ``client`` 4558 depending on whether the QEMU network backend that uses the 4559 credentials will be acting as a client or as a server. If 4560 ``verify-peer`` is enabled (the default) then once the handshake 4561 is completed, the peer credentials will be verified, though this 4562 is a no-op for anonymous credentials. 4563 4564 The dir parameter tells QEMU where to find the credential files. 4565 For server endpoints, this directory may contain a file 4566 dh-params.pem providing diffie-hellman parameters to use for the 4567 TLS server. If the file is missing, QEMU will generate a set of 4568 DH parameters at startup. This is a computationally expensive 4569 operation that consumes random pool entropy, so it is 4570 recommended that a persistent set of parameters be generated 4571 upfront and saved. 4572 4573 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]`` 4574 Creates a TLS Pre-Shared Keys (PSK) credentials object, which 4575 can be used to provide TLS support on network backends. The 4576 ``id`` parameter is a unique ID which network backends will use 4577 to access the credentials. The ``endpoint`` is either ``server`` 4578 or ``client`` depending on whether the QEMU network backend that 4579 uses the credentials will be acting as a client or as a server. 4580 For clients only, ``username`` is the username which will be 4581 sent to the server. If omitted it defaults to "qemu". 4582 4583 The dir parameter tells QEMU where to find the keys file. It is 4584 called "dir/keys.psk" and contains "username:key" pairs. This 4585 file can most easily be created using the GnuTLS ``psktool`` 4586 program. 4587 4588 For server endpoints, dir may also contain a file dh-params.pem 4589 providing diffie-hellman parameters to use for the TLS server. 4590 If the file is missing, QEMU will generate a set of DH 4591 parameters at startup. This is a computationally expensive 4592 operation that consumes random pool entropy, so it is 4593 recommended that a persistent set of parameters be generated up 4594 front and saved. 4595 4596 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id`` 4597 Creates a TLS anonymous credentials object, which can be used to 4598 provide TLS support on network backends. The ``id`` parameter is 4599 a unique ID which network backends will use to access the 4600 credentials. The ``endpoint`` is either ``server`` or ``client`` 4601 depending on whether the QEMU network backend that uses the 4602 credentials will be acting as a client or as a server. If 4603 ``verify-peer`` is enabled (the default) then once the handshake 4604 is completed, the peer credentials will be verified. With x509 4605 certificates, this implies that the clients must be provided 4606 with valid client certificates too. 4607 4608 The dir parameter tells QEMU where to find the credential files. 4609 For server endpoints, this directory may contain a file 4610 dh-params.pem providing diffie-hellman parameters to use for the 4611 TLS server. If the file is missing, QEMU will generate a set of 4612 DH parameters at startup. This is a computationally expensive 4613 operation that consumes random pool entropy, so it is 4614 recommended that a persistent set of parameters be generated 4615 upfront and saved. 4616 4617 For x509 certificate credentials the directory will contain 4618 further files providing the x509 certificates. The certificates 4619 must be stored in PEM format, in filenames ca-cert.pem, 4620 ca-crl.pem (optional), server-cert.pem (only servers), 4621 server-key.pem (only servers), client-cert.pem (only clients), 4622 and client-key.pem (only clients). 4623 4624 For the server-key.pem and client-key.pem files which contain 4625 sensitive private keys, it is possible to use an encrypted 4626 version by providing the passwordid parameter. This provides the 4627 ID of a previously created ``secret`` object containing the 4628 password for decryption. 4629 4630 The priority parameter allows to override the global default 4631 priority used by gnutls. This can be useful if the system 4632 administrator needs to use a weaker set of crypto priorities for 4633 QEMU without potentially forcing the weakness onto all 4634 applications. Or conversely if one wants wants a stronger 4635 default for QEMU than for all other applications, they can do 4636 this through this parameter. Its format is a gnutls priority 4637 string as described at 4638 https://gnutls.org/manual/html_node/Priority-Strings.html. 4639 4640 ``-object tls-cipher-suites,id=id,priority=priority`` 4641 Creates a TLS cipher suites object, which can be used to control 4642 the TLS cipher/protocol algorithms that applications are permitted 4643 to use. 4644 4645 The ``id`` parameter is a unique ID which frontends will use to 4646 access the ordered list of permitted TLS cipher suites from the 4647 host. 4648 4649 The ``priority`` parameter allows to override the global default 4650 priority used by gnutls. This can be useful if the system 4651 administrator needs to use a weaker set of crypto priorities for 4652 QEMU without potentially forcing the weakness onto all 4653 applications. Or conversely if one wants wants a stronger 4654 default for QEMU than for all other applications, they can do 4655 this through this parameter. Its format is a gnutls priority 4656 string as described at 4657 https://gnutls.org/manual/html_node/Priority-Strings.html. 4658 4659 An example of use of this object is to control UEFI HTTPS Boot. 4660 The tls-cipher-suites object exposes the ordered list of permitted 4661 TLS cipher suites from the host side to the guest firmware, via 4662 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER 4663 objects. The firmware uses the IANA_TLS_CIPHER array for configuring 4664 guest-side TLS. 4665 4666 In the following example, the priority at which the host-side policy 4667 is retrieved is given by the ``priority`` property. 4668 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to 4669 refer to /etc/crypto-policies/back-ends/gnutls.config. 4670 4671 .. parsed-literal:: 4672 4673 # |qemu_system| \\ 4674 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\ 4675 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 4676 4677 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` 4678 Interval t can't be 0, this filter batches the packet delivery: 4679 all packets arriving in a given interval on netdev netdevid are 4680 delayed until the end of the interval. Interval is in 4681 microseconds. ``status`` is optional that indicate whether the 4682 netfilter is on (enabled) or off (disabled), the default status 4683 for netfilter will be 'on'. 4684 4685 queue all\|rx\|tx is an option that can be applied to any 4686 netfilter. 4687 4688 ``all``: the filter is attached both to the receive and the 4689 transmit queue of the netdev (default). 4690 4691 ``rx``: the filter is attached to the receive queue of the 4692 netdev, where it will receive packets sent to the netdev. 4693 4694 ``tx``: the filter is attached to the transmit queue of the 4695 netdev, where it will receive packets sent by the netdev. 4696 4697 position head\|tail\|id=<id> is an option to specify where the 4698 filter should be inserted in the filter list. It can be applied 4699 to any netfilter. 4700 4701 ``head``: the filter is inserted at the head of the filter list, 4702 before any existing filters. 4703 4704 ``tail``: the filter is inserted at the tail of the filter list, 4705 behind any existing filters (default). 4706 4707 ``id=<id>``: the filter is inserted before or behind the filter 4708 specified by <id>, see the insert option below. 4709 4710 insert behind\|before is an option to specify where to insert 4711 the new filter relative to the one specified with 4712 position=id=<id>. It can be applied to any netfilter. 4713 4714 ``before``: insert before the specified filter. 4715 4716 ``behind``: insert behind the specified filter (default). 4717 4718 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 4719 filter-mirror on netdev netdevid,mirror net packet to 4720 chardevchardevid, if it has the vnet\_hdr\_support flag, 4721 filter-mirror will mirror packet with vnet\_hdr\_len. 4722 4723 ``-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]`` 4724 filter-redirector on netdev netdevid,redirect filter's net 4725 packet to chardev chardevid,and redirect indev's packet to 4726 filter.if it has the vnet\_hdr\_support flag, filter-redirector 4727 will redirect packet with vnet\_hdr\_len. Create a 4728 filter-redirector we need to differ outdev id from indev id, id 4729 can not be the same. we can just use indev or outdev, but at 4730 least one of indev or outdev need to be specified. 4731 4732 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 4733 Filter-rewriter is a part of COLO project.It will rewrite tcp 4734 packet to secondary from primary to keep secondary tcp 4735 connection,and rewrite tcp packet to primary from secondary make 4736 tcp packet can be handled by client.if it has the 4737 vnet\_hdr\_support flag, we can parse packet with vnet header. 4738 4739 usage: colo secondary: -object 4740 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object 4741 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object 4742 filter-rewriter,id=rew0,netdev=hn0,queue=all 4743 4744 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]`` 4745 Dump the network traffic on netdev dev to the file specified by 4746 filename. At most len bytes (64k by default) per packet are 4747 stored. The file format is libpcap, so it can be analyzed with 4748 tools such as tcpdump or Wireshark. 4749 4750 ``-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}]`` 4751 Colo-compare gets packet from primary\_in chardevid and 4752 secondary\_in, then compare whether the payload of primary packet 4753 and secondary packet are the same. If same, it will output 4754 primary packet to out\_dev, else it will notify COLO-framework to do 4755 checkpoint and send primary packet to out\_dev. In order to 4756 improve efficiency, we need to put the task of comparison in 4757 another iothread. If it has the vnet\_hdr\_support flag, 4758 colo compare will send/recv packet with vnet\_hdr\_len. 4759 The compare\_timeout=@var{ms} determines the maximum time of the 4760 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms} 4761 is to set the period of scanning expired primary node network packets. 4762 The max\_queue\_size=@var{size} is to set the max compare queue 4763 size depend on user environment. 4764 If user want to use Xen COLO, need to add the notify\_dev to 4765 notify Xen colo-frame to do checkpoint. 4766 4767 COLO-compare must be used with the help of filter-mirror, 4768 filter-redirector and filter-rewriter. 4769 4770 :: 4771 4772 KVM COLO 4773 4774 primary: 4775 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4776 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4777 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4778 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4779 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4780 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4781 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4782 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4783 -object iothread,id=iothread1 4784 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4785 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4786 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4787 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4788 4789 secondary: 4790 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4791 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4792 -chardev socket,id=red0,host=3.3.3.3,port=9003 4793 -chardev socket,id=red1,host=3.3.3.3,port=9004 4794 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4795 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4796 4797 4798 Xen COLO 4799 4800 primary: 4801 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4802 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4803 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4804 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4805 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4806 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4807 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4808 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4809 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4810 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4811 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4812 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4813 -object iothread,id=iothread1 4814 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4815 4816 secondary: 4817 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4818 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4819 -chardev socket,id=red0,host=3.3.3.3,port=9003 4820 -chardev socket,id=red1,host=3.3.3.3,port=9004 4821 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4822 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4823 4824 If you want to know the detail of above command line, you can 4825 read the colo-compare git log. 4826 4827 ``-object cryptodev-backend-builtin,id=id[,queues=queues]`` 4828 Creates a cryptodev backend which executes crypto opreation from 4829 the QEMU cipher APIS. The id parameter is a unique ID that will 4830 be used to reference this cryptodev backend from the 4831 ``virtio-crypto`` device. The queues parameter is optional, 4832 which specify the queue number of cryptodev backend, the default 4833 of queues is 1. 4834 4835 .. parsed-literal:: 4836 4837 # |qemu_system| \\ 4838 [...] \\ 4839 -object cryptodev-backend-builtin,id=cryptodev0 \\ 4840 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 4841 [...] 4842 4843 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]`` 4844 Creates a vhost-user cryptodev backend, backed by a chardev 4845 chardevid. The id parameter is a unique ID that will be used to 4846 reference this cryptodev backend from the ``virtio-crypto`` 4847 device. The chardev should be a unix domain socket backed one. 4848 The vhost-user uses a specifically defined protocol to pass 4849 vhost ioctl replacement messages to an application on the other 4850 end of the socket. The queues parameter is optional, which 4851 specify the queue number of cryptodev backend for multiqueue 4852 vhost-user, the default of queues is 1. 4853 4854 .. parsed-literal:: 4855 4856 # |qemu_system| \\ 4857 [...] \\ 4858 -chardev socket,id=chardev0,path=/path/to/socket \\ 4859 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\ 4860 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 4861 [...] 4862 4863 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]`` 4864 \ 4865 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]`` 4866 Defines a secret to store a password, encryption key, or some 4867 other sensitive data. The sensitive data can either be passed 4868 directly via the data parameter, or indirectly via the file 4869 parameter. Using the data parameter is insecure unless the 4870 sensitive data is encrypted. 4871 4872 The sensitive data can be provided in raw format (the default), 4873 or base64. When encoded as JSON, the raw format only supports 4874 valid UTF-8 characters, so base64 is recommended for sending 4875 binary data. QEMU will convert from which ever format is 4876 provided to the format it needs internally. eg, an RBD password 4877 can be provided in raw format, even though it will be base64 4878 encoded when passed onto the RBD sever. 4879 4880 For added protection, it is possible to encrypt the data 4881 associated with a secret using the AES-256-CBC cipher. Use of 4882 encryption is indicated by providing the keyid and iv 4883 parameters. The keyid parameter provides the ID of a previously 4884 defined secret that contains the AES-256 decryption key. This 4885 key should be 32-bytes long and be base64 encoded. The iv 4886 parameter provides the random initialization vector used for 4887 encryption of this particular secret and should be a base64 4888 encrypted string of the 16-byte IV. 4889 4890 The simplest (insecure) usage is to provide the secret inline 4891 4892 .. parsed-literal:: 4893 4894 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw 4895 4896 The simplest secure usage is to provide the secret via a file 4897 4898 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object 4899 secret,id=sec0,file=mypasswd.txt,format=raw 4900 4901 For greater security, AES-256-CBC should be used. To illustrate 4902 usage, consider the openssl command line tool which can encrypt 4903 the data. Note that when encrypting, the plaintext must be 4904 padded to the cipher block size (32 bytes) using the standard 4905 PKCS#5/6 compatible padding algorithm. 4906 4907 First a master key needs to be created in base64 encoding: 4908 4909 :: 4910 4911 # openssl rand -base64 32 > key.b64 4912 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4913 4914 Each secret to be encrypted needs to have a random 4915 initialization vector generated. These do not need to be kept 4916 secret 4917 4918 :: 4919 4920 # openssl rand -base64 16 > iv.b64 4921 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4922 4923 The secret to be defined can now be encrypted, in this case 4924 we're telling openssl to base64 encode the result, but it could 4925 be left as raw bytes if desired. 4926 4927 :: 4928 4929 # SECRET=$(printf "letmein" | 4930 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4931 4932 When launching QEMU, create a master secret pointing to 4933 ``key.b64`` and specify that to be used to decrypt the user 4934 password. Pass the contents of ``iv.b64`` to the second secret 4935 4936 .. parsed-literal:: 4937 4938 # |qemu_system| \\ 4939 -object secret,id=secmaster0,format=base64,file=key.b64 \\ 4940 -object secret,id=sec0,keyid=secmaster0,format=base64,\\ 4941 data=$SECRET,iv=$(<iv.b64) 4942 4943 ``-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]`` 4944 Create a Secure Encrypted Virtualization (SEV) guest object, 4945 which can be used to provide the guest memory encryption support 4946 on AMD processors. 4947 4948 When memory encryption is enabled, one of the physical address 4949 bit (aka the C-bit) is utilized to mark if a memory page is 4950 protected. The ``cbitpos`` is used to provide the C-bit 4951 position. The C-bit position is Host family dependent hence user 4952 must provide this value. On EPYC, the value should be 47. 4953 4954 When memory encryption is enabled, we loose certain bits in 4955 physical address space. The ``reduced-phys-bits`` is used to 4956 provide the number of bits we loose in physical address space. 4957 Similar to C-bit, the value is Host family dependent. On EPYC, 4958 the value should be 5. 4959 4960 The ``sev-device`` provides the device file to use for 4961 communicating with the SEV firmware running inside AMD Secure 4962 Processor. The default device is '/dev/sev'. If hardware 4963 supports memory encryption then /dev/sev devices are created by 4964 CCP driver. 4965 4966 The ``policy`` provides the guest policy to be enforced by the 4967 SEV firmware and restrict what configuration and operational 4968 commands can be performed on this guest by the hypervisor. The 4969 policy should be provided by the guest owner and is bound to the 4970 guest and cannot be changed throughout the lifetime of the 4971 guest. The default is 0. 4972 4973 If guest ``policy`` allows sharing the key with another SEV 4974 guest then ``handle`` can be use to provide handle of the guest 4975 from which to share the key. 4976 4977 The ``dh-cert-file`` and ``session-file`` provides the guest 4978 owner's Public Diffie-Hillman key defined in SEV spec. The PDH 4979 and session parameters are used for establishing a cryptographic 4980 session with the guest owner to negotiate keys used for 4981 attestation. The file must be encoded in base64. 4982 4983 e.g to launch a SEV guest 4984 4985 .. parsed-literal:: 4986 4987 # |qemu_system_x86| \\ 4988 ...... \\ 4989 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \\ 4990 -machine ...,memory-encryption=sev0 \\ 4991 ..... 4992 4993 ``-object authz-simple,id=id,identity=string`` 4994 Create an authorization object that will control access to 4995 network services. 4996 4997 The ``identity`` parameter is identifies the user and its format 4998 depends on the network service that authorization object is 4999 associated with. For authorizing based on TLS x509 certificates, 5000 the identity must be the x509 distinguished name. Note that care 5001 must be taken to escape any commas in the distinguished name. 5002 5003 An example authorization object to validate a x509 distinguished 5004 name would look like: 5005 5006 .. parsed-literal:: 5007 5008 # |qemu_system| \\ 5009 ... \\ 5010 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\ 5011 ... 5012 5013 Note the use of quotes due to the x509 distinguished name 5014 containing whitespace, and escaping of ','. 5015 5016 ``-object authz-listfile,id=id,filename=path,refresh=yes|no`` 5017 Create an authorization object that will control access to 5018 network services. 5019 5020 The ``filename`` parameter is the fully qualified path to a file 5021 containing the access control list rules in JSON format. 5022 5023 An example set of rules that match against SASL usernames might 5024 look like: 5025 5026 :: 5027 5028 { 5029 "rules": [ 5030 { "match": "fred", "policy": "allow", "format": "exact" }, 5031 { "match": "bob", "policy": "allow", "format": "exact" }, 5032 { "match": "danb", "policy": "deny", "format": "glob" }, 5033 { "match": "dan*", "policy": "allow", "format": "exact" }, 5034 ], 5035 "policy": "deny" 5036 } 5037 5038 When checking access the object will iterate over all the rules 5039 and the first rule to match will have its ``policy`` value 5040 returned as the result. If no rules match, then the default 5041 ``policy`` value is returned. 5042 5043 The rules can either be an exact string match, or they can use 5044 the simple UNIX glob pattern matching to allow wildcards to be 5045 used. 5046 5047 If ``refresh`` is set to true the file will be monitored and 5048 automatically reloaded whenever its content changes. 5049 5050 As with the ``authz-simple`` object, the format of the identity 5051 strings being matched depends on the network service, but is 5052 usually a TLS x509 distinguished name, or a SASL username. 5053 5054 An example authorization object to validate a SASL username 5055 would look like: 5056 5057 .. parsed-literal:: 5058 5059 # |qemu_system| \\ 5060 ... \\ 5061 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes \\ 5062 ... 5063 5064 ``-object authz-pam,id=id,service=string`` 5065 Create an authorization object that will control access to 5066 network services. 5067 5068 The ``service`` parameter provides the name of a PAM service to 5069 use for authorization. It requires that a file 5070 ``/etc/pam.d/service`` exist to provide the configuration for 5071 the ``account`` subsystem. 5072 5073 An example authorization object to validate a TLS x509 5074 distinguished name would look like: 5075 5076 .. parsed-literal:: 5077 5078 # |qemu_system| \\ 5079 ... \\ 5080 -object authz-pam,id=auth0,service=qemu-vnc \\ 5081 ... 5082 5083 There would then be a corresponding config file for PAM at 5084 ``/etc/pam.d/qemu-vnc`` that contains: 5085 5086 :: 5087 5088 account requisite pam_listfile.so item=user sense=allow \ 5089 file=/etc/qemu/vnc.allow 5090 5091 Finally the ``/etc/qemu/vnc.allow`` file would contain the list 5092 of x509 distingished names that are permitted access 5093 5094 :: 5095 5096 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 5097 5098 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink`` 5099 Creates a dedicated event loop thread that devices can be 5100 assigned to. This is known as an IOThread. By default device 5101 emulation happens in vCPU threads or the main event loop thread. 5102 This can become a scalability bottleneck. IOThreads allow device 5103 emulation and I/O to run on other host CPUs. 5104 5105 The ``id`` parameter is a unique ID that will be used to 5106 reference this IOThread from ``-device ...,iothread=id``. 5107 Multiple devices can be assigned to an IOThread. Note that not 5108 all devices support an ``iothread`` parameter. 5109 5110 The ``query-iothreads`` QMP command lists IOThreads and reports 5111 their thread IDs so that the user can configure host CPU 5112 pinning/affinity. 5113 5114 IOThreads use an adaptive polling algorithm to reduce event loop 5115 latency. Instead of entering a blocking system call to monitor 5116 file descriptors and then pay the cost of being woken up when an 5117 event occurs, the polling algorithm spins waiting for events for 5118 a short time. The algorithm's default parameters are suitable 5119 for many cases but can be adjusted based on knowledge of the 5120 workload and/or host device latency. 5121 5122 The ``poll-max-ns`` parameter is the maximum number of 5123 nanoseconds to busy wait for events. Polling can be disabled by 5124 setting this value to 0. 5125 5126 The ``poll-grow`` parameter is the multiplier used to increase 5127 the polling time when the algorithm detects it is missing events 5128 due to not polling long enough. 5129 5130 The ``poll-shrink`` parameter is the divisor used to decrease 5131 the polling time when the algorithm detects it is spending too 5132 long polling without encountering events. 5133 5134 The polling parameters can be modified at run-time using the 5135 ``qom-set`` command (where ``iothread1`` is the IOThread's 5136 ``id``): 5137 5138 :: 5139 5140 (qemu) qom-set /objects/iothread1 poll-max-ns 100000 5141ERST 5142 5143 5144HXCOMM This is the last statement. Insert new options before this line! 5145
