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