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