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, nvmm, 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 " memory-encryption=@var{} memory encryption object to use (default=none)\n" 38 " hmat=on|off controls ACPI HMAT support (default=off)\n" 39 " memory-backend='backend-id' specifies explicitly provided backend for main RAM (default=none)\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, nvmm, 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 ``memory-encryption=`` 95 Memory encryption object to use. The default is none. 96 97 ``hmat=on|off`` 98 Enables or disables ACPI Heterogeneous Memory Attribute Table 99 (HMAT) support. The default is off. 100 101 ``memory-backend='id'`` 102 An alternative to legacy ``-mem-path`` and ``mem-prealloc`` options. 103 Allows to use a memory backend as main RAM. 104 105 For example: 106 :: 107 108 -object memory-backend-file,id=pc.ram,size=512M,mem-path=/hugetlbfs,prealloc=on,share=on 109 -machine memory-backend=pc.ram 110 -m 512M 111 112 Migration compatibility note: 113 114 * as backend id one shall use value of 'default-ram-id', advertised by 115 machine type (available via ``query-machines`` QMP command), if migration 116 to/from old QEMU (<5.0) is expected. 117 * for machine types 4.0 and older, user shall 118 use ``x-use-canonical-path-for-ramblock-id=off`` backend option 119 if migration to/from old QEMU (<5.0) is expected. 120 121 For example: 122 :: 123 124 -object memory-backend-ram,id=pc.ram,size=512M,x-use-canonical-path-for-ramblock-id=off 125 -machine memory-backend=pc.ram 126 -m 512M 127ERST 128 129DEF("M", HAS_ARG, QEMU_OPTION_M, 130 " sgx-epc.0.memdev=memid,sgx-epc.0.node=numaid\n", 131 QEMU_ARCH_ALL) 132 133SRST 134``sgx-epc.0.memdev=@var{memid},sgx-epc.0.node=@var{numaid}`` 135 Define an SGX EPC section. 136ERST 137 138DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 139 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 140SRST 141``-cpu model`` 142 Select CPU model (``-cpu help`` for list and additional feature 143 selection) 144ERST 145 146DEF("accel", HAS_ARG, QEMU_OPTION_accel, 147 "-accel [accel=]accelerator[,prop[=value][,...]]\n" 148 " select accelerator (kvm, xen, hax, hvf, nvmm, whpx or tcg; use 'help' for a list)\n" 149 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n" 150 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n" 151 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n" 152 " split-wx=on|off (enable TCG split w^x mapping)\n" 153 " tb-size=n (TCG translation block cache size)\n" 154 " dirty-ring-size=n (KVM dirty ring GFN count, default 0)\n" 155 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 156SRST 157``-accel name[,prop=value[,...]]`` 158 This is used to enable an accelerator. Depending on the target 159 architecture, kvm, xen, hax, hvf, nvmm, whpx or tcg can be available. By 160 default, tcg is used. If there is more than one accelerator 161 specified, the next one is used if the previous one fails to 162 initialize. 163 164 ``igd-passthru=on|off`` 165 When Xen is in use, this option controls whether Intel 166 integrated graphics devices can be passed through to the guest 167 (default=off) 168 169 ``kernel-irqchip=on|off|split`` 170 Controls KVM in-kernel irqchip support. The default is full 171 acceleration of the interrupt controllers. On x86, split irqchip 172 reduces the kernel attack surface, at a performance cost for 173 non-MSI interrupts. Disabling the in-kernel irqchip completely 174 is not recommended except for debugging purposes. 175 176 ``kvm-shadow-mem=size`` 177 Defines the size of the KVM shadow MMU. 178 179 ``split-wx=on|off`` 180 Controls the use of split w^x mapping for the TCG code generation 181 buffer. Some operating systems require this to be enabled, and in 182 such a case this will default on. On other operating systems, this 183 will default off, but one may enable this for testing or debugging. 184 185 ``tb-size=n`` 186 Controls the size (in MiB) of the TCG translation block cache. 187 188 ``thread=single|multi`` 189 Controls number of TCG threads. When the TCG is multi-threaded 190 there will be one thread per vCPU therefore taking advantage of 191 additional host cores. The default is to enable multi-threading 192 where both the back-end and front-ends support it and no 193 incompatible TCG features have been enabled (e.g. 194 icount/replay). 195 196 ``dirty-ring-size=n`` 197 When the KVM accelerator is used, it controls the size of the per-vCPU 198 dirty page ring buffer (number of entries for each vCPU). It should 199 be a value that is power of two, and it should be 1024 or bigger (but 200 still less than the maximum value that the kernel supports). 4096 201 could be a good initial value if you have no idea which is the best. 202 Set this value to 0 to disable the feature. By default, this feature 203 is disabled (dirty-ring-size=0). When enabled, KVM will instead 204 record dirty pages in a bitmap. 205 206ERST 207 208DEF("smp", HAS_ARG, QEMU_OPTION_smp, 209 "-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]\n" 210 " set the number of initial CPUs to 'n' [default=1]\n" 211 " maxcpus= maximum number of total CPUs, including\n" 212 " offline CPUs for hotplug, etc\n" 213 " sockets= number of sockets on the machine board\n" 214 " dies= number of dies in one socket\n" 215 " clusters= number of clusters in one die\n" 216 " cores= number of cores in one cluster\n" 217 " threads= number of threads in one core\n" 218 "Note: Different machines may have different subsets of the CPU topology\n" 219 " parameters supported, so the actual meaning of the supported parameters\n" 220 " will vary accordingly. For example, for a machine type that supports a\n" 221 " three-level CPU hierarchy of sockets/cores/threads, the parameters will\n" 222 " sequentially mean as below:\n" 223 " sockets means the number of sockets on the machine board\n" 224 " cores means the number of cores in one socket\n" 225 " threads means the number of threads in one core\n" 226 " For a particular machine type board, an expected CPU topology hierarchy\n" 227 " can be defined through the supported sub-option. Unsupported parameters\n" 228 " can also be provided in addition to the sub-option, but their values\n" 229 " must be set as 1 in the purpose of correct parsing.\n", 230 QEMU_ARCH_ALL) 231SRST 232``-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]`` 233 Simulate a SMP system with '\ ``n``\ ' CPUs initially present on 234 the machine type board. On boards supporting CPU hotplug, the optional 235 '\ ``maxcpus``\ ' parameter can be set to enable further CPUs to be 236 added at runtime. When both parameters are omitted, the maximum number 237 of CPUs will be calculated from the provided topology members and the 238 initial CPU count will match the maximum number. When only one of them 239 is given then the omitted one will be set to its counterpart's value. 240 Both parameters may be specified, but the maximum number of CPUs must 241 be equal to or greater than the initial CPU count. Product of the 242 CPU topology hierarchy must be equal to the maximum number of CPUs. 243 Both parameters are subject to an upper limit that is determined by 244 the specific machine type chosen. 245 246 To control reporting of CPU topology information, values of the topology 247 parameters can be specified. Machines may only support a subset of the 248 parameters and different machines may have different subsets supported 249 which vary depending on capacity of the corresponding CPU targets. So 250 for a particular machine type board, an expected topology hierarchy can 251 be defined through the supported sub-option. Unsupported parameters can 252 also be provided in addition to the sub-option, but their values must be 253 set as 1 in the purpose of correct parsing. 254 255 Either the initial CPU count, or at least one of the topology parameters 256 must be specified. The specified parameters must be greater than zero, 257 explicit configuration like "cpus=0" is not allowed. Values for any 258 omitted parameters will be computed from those which are given. 259 260 For example, the following sub-option defines a CPU topology hierarchy 261 (2 sockets totally on the machine, 2 cores per socket, 2 threads per 262 core) for a machine that only supports sockets/cores/threads. 263 Some members of the option can be omitted but their values will be 264 automatically computed: 265 266 :: 267 268 -smp 8,sockets=2,cores=2,threads=2,maxcpus=8 269 270 The following sub-option defines a CPU topology hierarchy (2 sockets 271 totally on the machine, 2 dies per socket, 2 cores per die, 2 threads 272 per core) for PC machines which support sockets/dies/cores/threads. 273 Some members of the option can be omitted but their values will be 274 automatically computed: 275 276 :: 277 278 -smp 16,sockets=2,dies=2,cores=2,threads=2,maxcpus=16 279 280 Historically preference was given to the coarsest topology parameters 281 when computing missing values (ie sockets preferred over cores, which 282 were preferred over threads), however, this behaviour is considered 283 liable to change. Prior to 6.2 the preference was sockets over cores 284 over threads. Since 6.2 the preference is cores over sockets over threads. 285 286 For example, the following option defines a machine board with 2 sockets 287 of 1 core before 6.2 and 1 socket of 2 cores after 6.2: 288 289 :: 290 291 -smp 2 292ERST 293 294DEF("numa", HAS_ARG, QEMU_OPTION_numa, 295 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 296 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 297 "-numa dist,src=source,dst=destination,val=distance\n" 298 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n" 299 "-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" 300 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n", 301 QEMU_ARCH_ALL) 302SRST 303``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 304 \ 305``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 306 \ 307``-numa dist,src=source,dst=destination,val=distance`` 308 \ 309``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]`` 310 \ 311``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=tpye[,latency=lat][,bandwidth=bw]`` 312 \ 313``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]`` 314 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA 315 distance from a source node to a destination node. Set the ACPI 316 Heterogeneous Memory Attributes for the given nodes. 317 318 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and 319 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a 320 contiguous range of CPU indexes (or a single VCPU if lastcpu is 321 omitted). A non-contiguous set of VCPUs can be represented by 322 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is 323 omitted on all nodes, VCPUs are automatically split between them. 324 325 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a 326 NUMA node: 327 328 :: 329 330 -numa node,cpus=0-2,cpus=5 331 332 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option 333 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to 334 assign CPU objects to a node using topology layout properties of 335 CPU. The set of properties is machine specific, and depends on used 336 machine type/'\ ``smp``\ ' options. It could be queried with 337 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ ' 338 property specifies node to which CPU object will be assigned, it's 339 required for node to be declared with '\ ``node``\ ' option before 340 it's used with '\ ``cpu``\ ' option. 341 342 For example: 343 344 :: 345 346 -M pc \ 347 -smp 1,sockets=2,maxcpus=2 \ 348 -numa node,nodeid=0 -numa node,nodeid=1 \ 349 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 350 351 Legacy '\ ``mem``\ ' assigns a given RAM amount to a node (not supported 352 for 5.1 and newer machine types). '\ ``memdev``\ ' assigns RAM from 353 a given memory backend device to a node. If '\ ``mem``\ ' and 354 '\ ``memdev``\ ' are omitted in all nodes, RAM is split equally between them. 355 356 357 '\ ``mem``\ ' and '\ ``memdev``\ ' are mutually exclusive. 358 Furthermore, if one node uses '\ ``memdev``\ ', all of them have to 359 use it. 360 361 '\ ``initiator``\ ' is an additional option that points to an 362 initiator NUMA node that has best performance (the lowest latency or 363 largest bandwidth) to this NUMA node. Note that this option can be 364 set only when the machine property 'hmat' is set to 'on'. 365 366 Following example creates a machine with 2 NUMA nodes, node 0 has 367 CPU. node 1 has only memory, and its initiator is node 0. Note that 368 because node 0 has CPU, by default the initiator of node 0 is itself 369 and must be itself. 370 371 :: 372 373 -machine hmat=on \ 374 -m 2G,slots=2,maxmem=4G \ 375 -object memory-backend-ram,size=1G,id=m0 \ 376 -object memory-backend-ram,size=1G,id=m1 \ 377 -numa node,nodeid=0,memdev=m0 \ 378 -numa node,nodeid=1,memdev=m1,initiator=0 \ 379 -smp 2,sockets=2,maxcpus=2 \ 380 -numa cpu,node-id=0,socket-id=0 \ 381 -numa cpu,node-id=0,socket-id=1 382 383 source and destination are NUMA node IDs. distance is the NUMA 384 distance from source to destination. The distance from a node to 385 itself is always 10. If any pair of nodes is given a distance, then 386 all pairs must be given distances. Although, when distances are only 387 given in one direction for each pair of nodes, then the distances in 388 the opposite directions are assumed to be the same. If, however, an 389 asymmetrical pair of distances is given for even one node pair, then 390 all node pairs must be provided distance values for both directions, 391 even when they are symmetrical. When a node is unreachable from 392 another node, set the pair's distance to 255. 393 394 Note that the -``numa`` option doesn't allocate any of the specified 395 resources, it just assigns existing resources to NUMA nodes. This 396 means that one still has to use the ``-m``, ``-smp`` options to 397 allocate RAM and VCPUs respectively. 398 399 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth 400 Information between initiator and target NUMA nodes in ACPI 401 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can 402 create memory requests, usually it has one or more processors. 403 Target NUMA node contains addressable memory. 404 405 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is 406 the memory hierarchy of the target NUMA node: if hierarchy is 407 'memory', the structure represents the memory performance; if 408 hierarchy is 'first-level\|second-level\|third-level', this 409 structure represents aggregated performance of memory side caches 410 for each domain. type of 'data-type' is type of data represented by 411 this structure instance: if 'hierarchy' is 'memory', 'data-type' is 412 'access\|read\|write' latency or 'access\|read\|write' bandwidth of 413 the target memory; if 'hierarchy' is 414 'first-level\|second-level\|third-level', 'data-type' is 415 'access\|read\|write' hit latency or 'access\|read\|write' hit 416 bandwidth of the target memory side cache. 417 418 lat is latency value in nanoseconds. bw is bandwidth value, the 419 possible value and units are NUM[M\|G\|T], mean that the bandwidth 420 value are NUM byte per second (or MB/s, GB/s or TB/s depending on 421 used suffix). Note that if latency or bandwidth value is 0, means 422 the corresponding latency or bandwidth information is not provided. 423 424 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory 425 belongs. size is the size of memory side cache in bytes. level is 426 the cache level described in this structure, note that the cache 427 level 0 should not be used with '\ ``hmat-cache``\ ' option. 428 associativity is the cache associativity, the possible value is 429 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy 430 is the write policy. line is the cache Line size in bytes. 431 432 For example, the following options describe 2 NUMA nodes. Node 0 has 433 2 cpus and a ram, node 1 has only a ram. The processors in node 0 434 access memory in node 0 with access-latency 5 nanoseconds, 435 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access 436 memory in NUMA node 1 with access-latency 10 nanoseconds, 437 access-bandwidth is 100 MB/s. And for memory side cache information, 438 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB, 439 policy is write-back, the cache Line size is 8 bytes: 440 441 :: 442 443 -machine hmat=on \ 444 -m 2G \ 445 -object memory-backend-ram,size=1G,id=m0 \ 446 -object memory-backend-ram,size=1G,id=m1 \ 447 -smp 2,sockets=2,maxcpus=2 \ 448 -numa node,nodeid=0,memdev=m0 \ 449 -numa node,nodeid=1,memdev=m1,initiator=0 \ 450 -numa cpu,node-id=0,socket-id=0 \ 451 -numa cpu,node-id=0,socket-id=1 \ 452 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \ 453 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \ 454 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \ 455 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \ 456 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \ 457 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8 458ERST 459 460DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 461 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 462 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 463SRST 464``-add-fd fd=fd,set=set[,opaque=opaque]`` 465 Add a file descriptor to an fd set. Valid options are: 466 467 ``fd=fd`` 468 This option defines the file descriptor of which a duplicate is 469 added to fd set. The file descriptor cannot be stdin, stdout, or 470 stderr. 471 472 ``set=set`` 473 This option defines the ID of the fd set to add the file 474 descriptor to. 475 476 ``opaque=opaque`` 477 This option defines a free-form string that can be used to 478 describe fd. 479 480 You can open an image using pre-opened file descriptors from an fd 481 set: 482 483 .. parsed-literal:: 484 485 |qemu_system| \\ 486 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 487 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 488 -drive file=/dev/fdset/2,index=0,media=disk 489ERST 490 491DEF("set", HAS_ARG, QEMU_OPTION_set, 492 "-set group.id.arg=value\n" 493 " set <arg> parameter for item <id> of type <group>\n" 494 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 495SRST 496``-set group.id.arg=value`` 497 Set parameter arg for item id of type group 498ERST 499 500DEF("global", HAS_ARG, QEMU_OPTION_global, 501 "-global driver.property=value\n" 502 "-global driver=driver,property=property,value=value\n" 503 " set a global default for a driver property\n", 504 QEMU_ARCH_ALL) 505SRST 506``-global driver.prop=value`` 507 \ 508``-global driver=driver,property=property,value=value`` 509 Set default value of driver's property prop to value, e.g.: 510 511 .. parsed-literal:: 512 513 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img 514 515 In particular, you can use this to set driver properties for devices 516 which are created automatically by the machine model. To create a 517 device which is not created automatically and set properties on it, 518 use -``device``. 519 520 -global driver.prop=value is shorthand for -global 521 driver=driver,property=prop,value=value. The longhand syntax works 522 even when driver contains a dot. 523ERST 524 525DEF("boot", HAS_ARG, QEMU_OPTION_boot, 526 "-boot [order=drives][,once=drives][,menu=on|off]\n" 527 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 528 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 529 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 530 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 531 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 532 QEMU_ARCH_ALL) 533SRST 534``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]`` 535 Specify boot order drives as a string of drive letters. Valid drive 536 letters depend on the target architecture. The x86 PC uses: a, b 537 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p 538 (Etherboot from network adapter 1-4), hard disk boot is the default. 539 To apply a particular boot order only on the first startup, specify 540 it via ``once``. Note that the ``order`` or ``once`` parameter 541 should not be used together with the ``bootindex`` property of 542 devices, since the firmware implementations normally do not support 543 both at the same time. 544 545 Interactive boot menus/prompts can be enabled via ``menu=on`` as far 546 as firmware/BIOS supports them. The default is non-interactive boot. 547 548 A splash picture could be passed to bios, enabling user to show it 549 as logo, when option splash=sp\_name is given and menu=on, If 550 firmware/BIOS supports them. Currently Seabios for X86 system 551 support it. limitation: The splash file could be a jpeg file or a 552 BMP file in 24 BPP format(true color). The resolution should be 553 supported by the SVGA mode, so the recommended is 320x240, 640x480, 554 800x640. 555 556 A timeout could be passed to bios, guest will pause for rb\_timeout 557 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will 558 not reboot, qemu passes '-1' to bios by default. Currently Seabios 559 for X86 system support it. 560 561 Do strict boot via ``strict=on`` as far as firmware/BIOS supports 562 it. This only effects when boot priority is changed by bootindex 563 options. The default is non-strict boot. 564 565 .. parsed-literal:: 566 567 # try to boot from network first, then from hard disk 568 |qemu_system_x86| -boot order=nc 569 # boot from CD-ROM first, switch back to default order after reboot 570 |qemu_system_x86| -boot once=d 571 # boot with a splash picture for 5 seconds. 572 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000 573 574 Note: The legacy format '-boot drives' is still supported but its 575 use is discouraged as it may be removed from future versions. 576ERST 577 578DEF("m", HAS_ARG, QEMU_OPTION_m, 579 "-m [size=]megs[,slots=n,maxmem=size]\n" 580 " configure guest RAM\n" 581 " size: initial amount of guest memory\n" 582 " slots: number of hotplug slots (default: none)\n" 583 " maxmem: maximum amount of guest memory (default: none)\n" 584 "NOTE: Some architectures might enforce a specific granularity\n", 585 QEMU_ARCH_ALL) 586SRST 587``-m [size=]megs[,slots=n,maxmem=size]`` 588 Sets guest startup RAM size to megs megabytes. Default is 128 MiB. 589 Optionally, a suffix of "M" or "G" can be used to signify a value in 590 megabytes or gigabytes respectively. Optional pair slots, maxmem 591 could be used to set amount of hotpluggable memory slots and maximum 592 amount of memory. Note that maxmem must be aligned to the page size. 593 594 For example, the following command-line sets the guest startup RAM 595 size to 1GB, creates 3 slots to hotplug additional memory and sets 596 the maximum memory the guest can reach to 4GB: 597 598 .. parsed-literal:: 599 600 |qemu_system| -m 1G,slots=3,maxmem=4G 601 602 If slots and maxmem are not specified, memory hotplug won't be 603 enabled and the guest startup RAM will never increase. 604ERST 605 606DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 607 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 608SRST 609``-mem-path path`` 610 Allocate guest RAM from a temporarily created file in path. 611ERST 612 613DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 614 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 615 QEMU_ARCH_ALL) 616SRST 617``-mem-prealloc`` 618 Preallocate memory when using -mem-path. 619ERST 620 621DEF("k", HAS_ARG, QEMU_OPTION_k, 622 "-k language use keyboard layout (for example 'fr' for French)\n", 623 QEMU_ARCH_ALL) 624SRST 625``-k language`` 626 Use keyboard layout language (for example ``fr`` for French). This 627 option is only needed where it is not easy to get raw PC keycodes 628 (e.g. on Macs, with some X11 servers or with a VNC or curses 629 display). You don't normally need to use it on PC/Linux or 630 PC/Windows hosts. 631 632 The available layouts are: 633 634 :: 635 636 ar de-ch es fo fr-ca hu ja mk no pt-br sv 637 da en-gb et fr fr-ch is lt nl pl ru th 638 de en-us fi fr-be hr it lv nl-be pt sl tr 639 640 The default is ``en-us``. 641ERST 642 643 644HXCOMM Deprecated by -audiodev 645DEF("audio-help", 0, QEMU_OPTION_audio_help, 646 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 647 QEMU_ARCH_ALL) 648SRST 649``-audio-help`` 650 Will show the -audiodev equivalent of the currently specified 651 (deprecated) environment variables. 652ERST 653 654DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 655 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 656 " specifies the audio backend to use\n" 657 " id= identifier of the backend\n" 658 " timer-period= timer period in microseconds\n" 659 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 660 " in|out.fixed-settings= use fixed settings for host audio\n" 661 " in|out.frequency= frequency to use with fixed settings\n" 662 " in|out.channels= number of channels to use with fixed settings\n" 663 " in|out.format= sample format to use with fixed settings\n" 664 " valid values: s8, s16, s32, u8, u16, u32, f32\n" 665 " in|out.voices= number of voices to use\n" 666 " in|out.buffer-length= length of buffer in microseconds\n" 667 "-audiodev none,id=id,[,prop[=value][,...]]\n" 668 " dummy driver that discards all output\n" 669#ifdef CONFIG_AUDIO_ALSA 670 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 671 " in|out.dev= name of the audio device to use\n" 672 " in|out.period-length= length of period in microseconds\n" 673 " in|out.try-poll= attempt to use poll mode\n" 674 " threshold= threshold (in microseconds) when playback starts\n" 675#endif 676#ifdef CONFIG_AUDIO_COREAUDIO 677 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 678 " in|out.buffer-count= number of buffers\n" 679#endif 680#ifdef CONFIG_AUDIO_DSOUND 681 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 682 " latency= add extra latency to playback in microseconds\n" 683#endif 684#ifdef CONFIG_AUDIO_OSS 685 "-audiodev oss,id=id[,prop[=value][,...]]\n" 686 " in|out.dev= path of the audio device to use\n" 687 " in|out.buffer-count= number of buffers\n" 688 " in|out.try-poll= attempt to use poll mode\n" 689 " try-mmap= try using memory mapped access\n" 690 " exclusive= open device in exclusive mode\n" 691 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 692#endif 693#ifdef CONFIG_AUDIO_PA 694 "-audiodev pa,id=id[,prop[=value][,...]]\n" 695 " server= PulseAudio server address\n" 696 " in|out.name= source/sink device name\n" 697 " in|out.latency= desired latency in microseconds\n" 698#endif 699#ifdef CONFIG_AUDIO_SDL 700 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 701 " in|out.buffer-count= number of buffers\n" 702#endif 703#ifdef CONFIG_SPICE 704 "-audiodev spice,id=id[,prop[=value][,...]]\n" 705#endif 706#ifdef CONFIG_DBUS_DISPLAY 707 "-audiodev dbus,id=id[,prop[=value][,...]]\n" 708#endif 709 "-audiodev wav,id=id[,prop[=value][,...]]\n" 710 " path= path of wav file to record\n", 711 QEMU_ARCH_ALL) 712SRST 713``-audiodev [driver=]driver,id=id[,prop[=value][,...]]`` 714 Adds a new audio backend driver identified by id. There are global 715 and driver specific properties. Some values can be set differently 716 for input and output, they're marked with ``in|out.``. You can set 717 the input's property with ``in.prop`` and the output's property with 718 ``out.prop``. For example: 719 720 :: 721 722 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 723 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 724 725 NOTE: parameter validation is known to be incomplete, in many cases 726 specifying an invalid option causes QEMU to print an error message 727 and continue emulation without sound. 728 729 Valid global options are: 730 731 ``id=identifier`` 732 Identifies the audio backend. 733 734 ``timer-period=period`` 735 Sets the timer period used by the audio subsystem in 736 microseconds. Default is 10000 (10 ms). 737 738 ``in|out.mixing-engine=on|off`` 739 Use QEMU's mixing engine to mix all streams inside QEMU and 740 convert audio formats when not supported by the backend. When 741 off, fixed-settings must be off too. Note that disabling this 742 option means that the selected backend must support multiple 743 streams and the audio formats used by the virtual cards, 744 otherwise you'll get no sound. It's not recommended to disable 745 this option unless you want to use 5.1 or 7.1 audio, as mixing 746 engine only supports mono and stereo audio. Default is on. 747 748 ``in|out.fixed-settings=on|off`` 749 Use fixed settings for host audio. When off, it will change 750 based on how the guest opens the sound card. In this case you 751 must not specify frequency, channels or format. Default is on. 752 753 ``in|out.frequency=frequency`` 754 Specify the frequency to use when using fixed-settings. Default 755 is 44100Hz. 756 757 ``in|out.channels=channels`` 758 Specify the number of channels to use when using fixed-settings. 759 Default is 2 (stereo). 760 761 ``in|out.format=format`` 762 Specify the sample format to use when using fixed-settings. 763 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``, 764 ``u32``, ``f32``. Default is ``s16``. 765 766 ``in|out.voices=voices`` 767 Specify the number of voices to use. Default is 1. 768 769 ``in|out.buffer-length=usecs`` 770 Sets the size of the buffer in microseconds. 771 772``-audiodev none,id=id[,prop[=value][,...]]`` 773 Creates a dummy backend that discards all outputs. This backend has 774 no backend specific properties. 775 776``-audiodev alsa,id=id[,prop[=value][,...]]`` 777 Creates backend using the ALSA. This backend is only available on 778 Linux. 779 780 ALSA specific options are: 781 782 ``in|out.dev=device`` 783 Specify the ALSA device to use for input and/or output. Default 784 is ``default``. 785 786 ``in|out.period-length=usecs`` 787 Sets the period length in microseconds. 788 789 ``in|out.try-poll=on|off`` 790 Attempt to use poll mode with the device. Default is on. 791 792 ``threshold=threshold`` 793 Threshold (in microseconds) when playback starts. Default is 0. 794 795``-audiodev coreaudio,id=id[,prop[=value][,...]]`` 796 Creates a backend using Apple's Core Audio. This backend is only 797 available on Mac OS and only supports playback. 798 799 Core Audio specific options are: 800 801 ``in|out.buffer-count=count`` 802 Sets the count of the buffers. 803 804``-audiodev dsound,id=id[,prop[=value][,...]]`` 805 Creates a backend using Microsoft's DirectSound. This backend is 806 only available on Windows and only supports playback. 807 808 DirectSound specific options are: 809 810 ``latency=usecs`` 811 Add extra usecs microseconds latency to playback. Default is 812 10000 (10 ms). 813 814``-audiodev oss,id=id[,prop[=value][,...]]`` 815 Creates a backend using OSS. This backend is available on most 816 Unix-like systems. 817 818 OSS specific options are: 819 820 ``in|out.dev=device`` 821 Specify the file name of the OSS device to use. Default is 822 ``/dev/dsp``. 823 824 ``in|out.buffer-count=count`` 825 Sets the count of the buffers. 826 827 ``in|out.try-poll=on|of`` 828 Attempt to use poll mode with the device. Default is on. 829 830 ``try-mmap=on|off`` 831 Try using memory mapped device access. Default is off. 832 833 ``exclusive=on|off`` 834 Open the device in exclusive mode (vmix won't work in this 835 case). Default is off. 836 837 ``dsp-policy=policy`` 838 Sets the timing policy (between 0 and 10, where smaller number 839 means smaller latency but higher CPU usage). Use -1 to use 840 buffer sizes specified by ``buffer`` and ``buffer-count``. This 841 option is ignored if you do not have OSS 4. Default is 5. 842 843``-audiodev pa,id=id[,prop[=value][,...]]`` 844 Creates a backend using PulseAudio. This backend is available on 845 most systems. 846 847 PulseAudio specific options are: 848 849 ``server=server`` 850 Sets the PulseAudio server to connect to. 851 852 ``in|out.name=sink`` 853 Use the specified source/sink for recording/playback. 854 855 ``in|out.latency=usecs`` 856 Desired latency in microseconds. The PulseAudio server will try 857 to honor this value but actual latencies may be lower or higher. 858 859``-audiodev sdl,id=id[,prop[=value][,...]]`` 860 Creates a backend using SDL. This backend is available on most 861 systems, but you should use your platform's native backend if 862 possible. 863 864 SDL specific options are: 865 866 ``in|out.buffer-count=count`` 867 Sets the count of the buffers. 868 869``-audiodev spice,id=id[,prop[=value][,...]]`` 870 Creates a backend that sends audio through SPICE. This backend 871 requires ``-spice`` and automatically selected in that case, so 872 usually you can ignore this option. This backend has no backend 873 specific properties. 874 875``-audiodev wav,id=id[,prop[=value][,...]]`` 876 Creates a backend that writes audio to a WAV file. 877 878 Backend specific options are: 879 880 ``path=path`` 881 Write recorded audio into the specified file. Default is 882 ``qemu.wav``. 883ERST 884 885DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 886 "-soundhw c1,... enable audio support\n" 887 " and only specified sound cards (comma separated list)\n" 888 " use '-soundhw help' to get the list of supported cards\n" 889 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 890SRST 891``-soundhw card1[,card2,...] or -soundhw all`` 892 Enable audio and selected sound hardware. Use 'help' to print all 893 available sound hardware. For example: 894 895 .. parsed-literal:: 896 897 |qemu_system_x86| -soundhw sb16,adlib disk.img 898 |qemu_system_x86| -soundhw es1370 disk.img 899 |qemu_system_x86| -soundhw ac97 disk.img 900 |qemu_system_x86| -soundhw hda disk.img 901 |qemu_system_x86| -soundhw all disk.img 902 |qemu_system_x86| -soundhw help 903 904 Note that Linux's i810\_audio OSS kernel (for AC97) module might 905 require manually specifying clocking. 906 907 :: 908 909 modprobe i810_audio clocking=48000 910ERST 911 912DEF("device", HAS_ARG, QEMU_OPTION_device, 913 "-device driver[,prop[=value][,...]]\n" 914 " add device (based on driver)\n" 915 " prop=value,... sets driver properties\n" 916 " use '-device help' to print all possible drivers\n" 917 " use '-device driver,help' to print all possible properties\n", 918 QEMU_ARCH_ALL) 919SRST 920``-device driver[,prop[=value][,...]]`` 921 Add device driver. prop=value sets driver properties. Valid 922 properties depend on the driver. To get help on possible drivers and 923 properties, use ``-device help`` and ``-device driver,help``. 924 925 Some drivers are: 926 927``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]`` 928 Add an IPMI BMC. This is a simulation of a hardware management 929 interface processor that normally sits on a system. It provides a 930 watchdog and the ability to reset and power control the system. You 931 need to connect this to an IPMI interface to make it useful 932 933 The IPMI slave address to use for the BMC. The default is 0x20. This 934 address is the BMC's address on the I2C network of management 935 controllers. If you don't know what this means, it is safe to ignore 936 it. 937 938 ``id=id`` 939 The BMC id for interfaces to use this device. 940 941 ``slave_addr=val`` 942 Define slave address to use for the BMC. The default is 0x20. 943 944 ``sdrfile=file`` 945 file containing raw Sensor Data Records (SDR) data. The default 946 is none. 947 948 ``fruareasize=val`` 949 size of a Field Replaceable Unit (FRU) area. The default is 950 1024. 951 952 ``frudatafile=file`` 953 file containing raw Field Replaceable Unit (FRU) inventory data. 954 The default is none. 955 956 ``guid=uuid`` 957 value for the GUID for the BMC, in standard UUID format. If this 958 is set, get "Get GUID" command to the BMC will return it. 959 Otherwise "Get GUID" will return an error. 960 961``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]`` 962 Add a connection to an external IPMI BMC simulator. Instead of 963 locally emulating the BMC like the above item, instead connect to an 964 external entity that provides the IPMI services. 965 966 A connection is made to an external BMC simulator. If you do this, 967 it is strongly recommended that you use the "reconnect=" chardev 968 option to reconnect to the simulator if the connection is lost. Note 969 that if this is not used carefully, it can be a security issue, as 970 the interface has the ability to send resets, NMIs, and power off 971 the VM. It's best if QEMU makes a connection to an external 972 simulator running on a secure port on localhost, so neither the 973 simulator nor QEMU is exposed to any outside network. 974 975 See the "lanserv/README.vm" file in the OpenIPMI library for more 976 details on the external interface. 977 978``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]`` 979 Add a KCS IPMI interafce on the ISA bus. This also adds a 980 corresponding ACPI and SMBIOS entries, if appropriate. 981 982 ``bmc=id`` 983 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern 984 above. 985 986 ``ioport=val`` 987 Define the I/O address of the interface. The default is 0xca0 988 for KCS. 989 990 ``irq=val`` 991 Define the interrupt to use. The default is 5. To disable 992 interrupts, set this to 0. 993 994``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]`` 995 Like the KCS interface, but defines a BT interface. The default port 996 is 0xe4 and the default interrupt is 5. 997 998``-device pci-ipmi-kcs,bmc=id`` 999 Add a KCS IPMI interafce on the PCI bus. 1000 1001 ``bmc=id`` 1002 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 1003 1004``-device pci-ipmi-bt,bmc=id`` 1005 Like the KCS interface, but defines a BT interface on the PCI bus. 1006 1007``-device intel-iommu[,option=...]`` 1008 This is only supported by ``-machine q35``, which will enable Intel VT-d 1009 emulation within the guest. It supports below options: 1010 1011 ``intremap=on|off`` (default: auto) 1012 This enables interrupt remapping feature. It's required to enable 1013 complete x2apic. Currently it only supports kvm kernel-irqchip modes 1014 ``off`` or ``split``, while full kernel-irqchip is not yet supported. 1015 The default value is "auto", which will be decided by the mode of 1016 kernel-irqchip. 1017 1018 ``caching-mode=on|off`` (default: off) 1019 This enables caching mode for the VT-d emulated device. When 1020 caching-mode is enabled, each guest DMA buffer mapping will generate an 1021 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in 1022 a synchronous way. It is required for ``-device vfio-pci`` to work 1023 with the VT-d device, because host assigned devices requires to setup 1024 the DMA mapping on the host before guest DMA starts. 1025 1026 ``device-iotlb=on|off`` (default: off) 1027 This enables device-iotlb capability for the emulated VT-d device. So 1028 far virtio/vhost should be the only real user for this parameter, 1029 paired with ats=on configured for the device. 1030 1031 ``aw-bits=39|48`` (default: 39) 1032 This decides the address width of IOVA address space. The address 1033 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for 1034 4-level IOMMU page tables. 1035 1036 Please also refer to the wiki page for general scenarios of VT-d 1037 emulation in QEMU: https://wiki.qemu.org/Features/VT-d. 1038 1039ERST 1040 1041DEF("name", HAS_ARG, QEMU_OPTION_name, 1042 "-name string1[,process=string2][,debug-threads=on|off]\n" 1043 " set the name of the guest\n" 1044 " string1 sets the window title and string2 the process name\n" 1045 " When debug-threads is enabled, individual threads are given a separate name\n" 1046 " NOTE: The thread names are for debugging and not a stable API.\n", 1047 QEMU_ARCH_ALL) 1048SRST 1049``-name name`` 1050 Sets the name of the guest. This name will be displayed in the SDL 1051 window caption. The name will also be used for the VNC server. Also 1052 optionally set the top visible process name in Linux. Naming of 1053 individual threads can also be enabled on Linux to aid debugging. 1054ERST 1055 1056DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 1057 "-uuid %08x-%04x-%04x-%04x-%012x\n" 1058 " specify machine UUID\n", QEMU_ARCH_ALL) 1059SRST 1060``-uuid uuid`` 1061 Set system UUID. 1062ERST 1063 1064DEFHEADING() 1065 1066DEFHEADING(Block device options:) 1067 1068DEF("fda", HAS_ARG, QEMU_OPTION_fda, 1069 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 1070DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 1071SRST 1072``-fda file`` 1073 \ 1074``-fdb file`` 1075 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in 1076 the System Emulation Users Guide). 1077ERST 1078 1079DEF("hda", HAS_ARG, QEMU_OPTION_hda, 1080 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 1081DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 1082DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 1083 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 1084DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 1085SRST 1086``-hda file`` 1087 \ 1088``-hdb file`` 1089 \ 1090``-hdc file`` 1091 \ 1092``-hdd file`` 1093 Use file as hard disk 0, 1, 2 or 3 image (see the :ref:`disk images` 1094 chapter in the System Emulation Users Guide). 1095ERST 1096 1097DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 1098 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 1099 QEMU_ARCH_ALL) 1100SRST 1101``-cdrom file`` 1102 Use file as CD-ROM image (you cannot use ``-hdc`` and ``-cdrom`` at 1103 the same time). You can use the host CD-ROM by using ``/dev/cdrom`` 1104 as filename. 1105ERST 1106 1107DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 1108 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 1109 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 1110 " [,read-only=on|off][,auto-read-only=on|off]\n" 1111 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 1112 " [,driver specific parameters...]\n" 1113 " configure a block backend\n", QEMU_ARCH_ALL) 1114SRST 1115``-blockdev option[,option[,option[,...]]]`` 1116 Define a new block driver node. Some of the options apply to all 1117 block drivers, other options are only accepted for a specific block 1118 driver. See below for a list of generic options and options for the 1119 most common block drivers. 1120 1121 Options that expect a reference to another node (e.g. ``file``) can 1122 be given in two ways. Either you specify the node name of an already 1123 existing node (file=node-name), or you define a new node inline, 1124 adding options for the referenced node after a dot 1125 (file.filename=path,file.aio=native). 1126 1127 A block driver node created with ``-blockdev`` can be used for a 1128 guest device by specifying its node name for the ``drive`` property 1129 in a ``-device`` argument that defines a block device. 1130 1131 ``Valid options for any block driver node:`` 1132 ``driver`` 1133 Specifies the block driver to use for the given node. 1134 1135 ``node-name`` 1136 This defines the name of the block driver node by which it 1137 will be referenced later. The name must be unique, i.e. it 1138 must not match the name of a different block driver node, or 1139 (if you use ``-drive`` as well) the ID of a drive. 1140 1141 If no node name is specified, it is automatically generated. 1142 The generated node name is not intended to be predictable 1143 and changes between QEMU invocations. For the top level, an 1144 explicit node name must be specified. 1145 1146 ``read-only`` 1147 Open the node read-only. Guest write attempts will fail. 1148 1149 Note that some block drivers support only read-only access, 1150 either generally or in certain configurations. In this case, 1151 the default value ``read-only=off`` does not work and the 1152 option must be specified explicitly. 1153 1154 ``auto-read-only`` 1155 If ``auto-read-only=on`` is set, QEMU may fall back to 1156 read-only usage even when ``read-only=off`` is requested, or 1157 even switch between modes as needed, e.g. depending on 1158 whether the image file is writable or whether a writing user 1159 is attached to the node. 1160 1161 ``force-share`` 1162 Override the image locking system of QEMU by forcing the 1163 node to utilize weaker shared access for permissions where 1164 it would normally request exclusive access. When there is 1165 the potential for multiple instances to have the same file 1166 open (whether this invocation of QEMU is the first or the 1167 second instance), both instances must permit shared access 1168 for the second instance to succeed at opening the file. 1169 1170 Enabling ``force-share=on`` requires ``read-only=on``. 1171 1172 ``cache.direct`` 1173 The host page cache can be avoided with ``cache.direct=on``. 1174 This will attempt to do disk IO directly to the guest's 1175 memory. QEMU may still perform an internal copy of the data. 1176 1177 ``cache.no-flush`` 1178 In case you don't care about data integrity over host 1179 failures, you can use ``cache.no-flush=on``. This option 1180 tells QEMU that it never needs to write any data to the disk 1181 but can instead keep things in cache. If anything goes 1182 wrong, like your host losing power, the disk storage getting 1183 disconnected accidentally, etc. your image will most 1184 probably be rendered unusable. 1185 1186 ``discard=discard`` 1187 discard is one of "ignore" (or "off") or "unmap" (or "on") 1188 and controls whether ``discard`` (also known as ``trim`` or 1189 ``unmap``) requests are ignored or passed to the filesystem. 1190 Some machine types may not support discard requests. 1191 1192 ``detect-zeroes=detect-zeroes`` 1193 detect-zeroes is "off", "on" or "unmap" and enables the 1194 automatic conversion of plain zero writes by the OS to 1195 driver specific optimized zero write commands. You may even 1196 choose "unmap" if discard is set to "unmap" to allow a zero 1197 write to be converted to an ``unmap`` operation. 1198 1199 ``Driver-specific options for file`` 1200 This is the protocol-level block driver for accessing regular 1201 files. 1202 1203 ``filename`` 1204 The path to the image file in the local filesystem 1205 1206 ``aio`` 1207 Specifies the AIO backend (threads/native/io_uring, 1208 default: threads) 1209 1210 ``locking`` 1211 Specifies whether the image file is protected with Linux OFD 1212 / POSIX locks. The default is to use the Linux Open File 1213 Descriptor API if available, otherwise no lock is applied. 1214 (auto/on/off, default: auto) 1215 1216 Example: 1217 1218 :: 1219 1220 -blockdev driver=file,node-name=disk,filename=disk.img 1221 1222 ``Driver-specific options for raw`` 1223 This is the image format block driver for raw images. It is 1224 usually stacked on top of a protocol level block driver such as 1225 ``file``. 1226 1227 ``file`` 1228 Reference to or definition of the data source block driver 1229 node (e.g. a ``file`` driver node) 1230 1231 Example 1: 1232 1233 :: 1234 1235 -blockdev driver=file,node-name=disk_file,filename=disk.img 1236 -blockdev driver=raw,node-name=disk,file=disk_file 1237 1238 Example 2: 1239 1240 :: 1241 1242 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1243 1244 ``Driver-specific options for qcow2`` 1245 This is the image format block driver for qcow2 images. It is 1246 usually stacked on top of a protocol level block driver such as 1247 ``file``. 1248 1249 ``file`` 1250 Reference to or definition of the data source block driver 1251 node (e.g. a ``file`` driver node) 1252 1253 ``backing`` 1254 Reference to or definition of the backing file block device 1255 (default is taken from the image file). It is allowed to 1256 pass ``null`` here in order to disable the default backing 1257 file. 1258 1259 ``lazy-refcounts`` 1260 Whether to enable the lazy refcounts feature (on/off; 1261 default is taken from the image file) 1262 1263 ``cache-size`` 1264 The maximum total size of the L2 table and refcount block 1265 caches in bytes (default: the sum of l2-cache-size and 1266 refcount-cache-size) 1267 1268 ``l2-cache-size`` 1269 The maximum size of the L2 table cache in bytes (default: if 1270 cache-size is not specified - 32M on Linux platforms, and 8M 1271 on non-Linux platforms; otherwise, as large as possible 1272 within the cache-size, while permitting the requested or the 1273 minimal refcount cache size) 1274 1275 ``refcount-cache-size`` 1276 The maximum size of the refcount block cache in bytes 1277 (default: 4 times the cluster size; or if cache-size is 1278 specified, the part of it which is not used for the L2 1279 cache) 1280 1281 ``cache-clean-interval`` 1282 Clean unused entries in the L2 and refcount caches. The 1283 interval is in seconds. The default value is 600 on 1284 supporting platforms, and 0 on other platforms. Setting it 1285 to 0 disables this feature. 1286 1287 ``pass-discard-request`` 1288 Whether discard requests to the qcow2 device should be 1289 forwarded to the data source (on/off; default: on if 1290 discard=unmap is specified, off otherwise) 1291 1292 ``pass-discard-snapshot`` 1293 Whether discard requests for the data source should be 1294 issued when a snapshot operation (e.g. deleting a snapshot) 1295 frees clusters in the qcow2 file (on/off; default: on) 1296 1297 ``pass-discard-other`` 1298 Whether discard requests for the data source should be 1299 issued on other occasions where a cluster gets freed 1300 (on/off; default: off) 1301 1302 ``overlap-check`` 1303 Which overlap checks to perform for writes to the image 1304 (none/constant/cached/all; default: cached). For details or 1305 finer granularity control refer to the QAPI documentation of 1306 ``blockdev-add``. 1307 1308 Example 1: 1309 1310 :: 1311 1312 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1313 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1314 1315 Example 2: 1316 1317 :: 1318 1319 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1320 1321 ``Driver-specific options for other drivers`` 1322 Please refer to the QAPI documentation of the ``blockdev-add`` 1323 QMP command. 1324ERST 1325 1326DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1327 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1328 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1329 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1330 " [,werror=ignore|stop|report|enospc][,id=name]\n" 1331 " [,aio=threads|native|io_uring]\n" 1332 " [,readonly=on|off][,copy-on-read=on|off]\n" 1333 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1334 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1335 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1336 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1337 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1338 " [[,iops_size=is]]\n" 1339 " [[,group=g]]\n" 1340 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1341SRST 1342``-drive option[,option[,option[,...]]]`` 1343 Define a new drive. This includes creating a block driver node (the 1344 backend) as well as a guest device, and is mostly a shortcut for 1345 defining the corresponding ``-blockdev`` and ``-device`` options. 1346 1347 ``-drive`` accepts all options that are accepted by ``-blockdev``. 1348 In addition, it knows the following options: 1349 1350 ``file=file`` 1351 This option defines which disk image (see the :ref:`disk images` 1352 chapter in the System Emulation Users Guide) to use with this drive. 1353 If the filename contains comma, you must double it (for instance, 1354 "file=my,,file" to use file "my,file"). 1355 1356 Special files such as iSCSI devices can be specified using 1357 protocol specific URLs. See the section for "Device URL Syntax" 1358 for more information. 1359 1360 ``if=interface`` 1361 This option defines on which type on interface the drive is 1362 connected. Available types are: ide, scsi, sd, mtd, floppy, 1363 pflash, virtio, none. 1364 1365 ``bus=bus,unit=unit`` 1366 These options define where is connected the drive by defining 1367 the bus number and the unit id. 1368 1369 ``index=index`` 1370 This option defines where is connected the drive by using an 1371 index in the list of available connectors of a given interface 1372 type. 1373 1374 ``media=media`` 1375 This option defines the type of the media: disk or cdrom. 1376 1377 ``snapshot=snapshot`` 1378 snapshot is "on" or "off" and controls snapshot mode for the 1379 given drive (see ``-snapshot``). 1380 1381 ``cache=cache`` 1382 cache is "none", "writeback", "unsafe", "directsync" or 1383 "writethrough" and controls how the host cache is used to access 1384 block data. This is a shortcut that sets the ``cache.direct`` 1385 and ``cache.no-flush`` options (as in ``-blockdev``), and 1386 additionally ``cache.writeback``, which provides a default for 1387 the ``write-cache`` option of block guest devices (as in 1388 ``-device``). The modes correspond to the following settings: 1389 1390 ============= =============== ============ ============== 1391 \ cache.writeback cache.direct cache.no-flush 1392 ============= =============== ============ ============== 1393 writeback on off off 1394 none on on off 1395 writethrough off off off 1396 directsync off on off 1397 unsafe on off on 1398 ============= =============== ============ ============== 1399 1400 The default mode is ``cache=writeback``. 1401 1402 ``aio=aio`` 1403 aio is "threads", "native", or "io_uring" and selects between pthread 1404 based disk I/O, native Linux AIO, or Linux io_uring API. 1405 1406 ``format=format`` 1407 Specify which disk format will be used rather than detecting the 1408 format. Can be used to specify format=raw to avoid interpreting 1409 an untrusted format header. 1410 1411 ``werror=action,rerror=action`` 1412 Specify which action to take on write and read errors. Valid 1413 actions are: "ignore" (ignore the error and try to continue), 1414 "stop" (pause QEMU), "report" (report the error to the guest), 1415 "enospc" (pause QEMU only if the host disk is full; report the 1416 error to the guest otherwise). The default setting is 1417 ``werror=enospc`` and ``rerror=report``. 1418 1419 ``copy-on-read=copy-on-read`` 1420 copy-on-read is "on" or "off" and enables whether to copy read 1421 backing file sectors into the image file. 1422 1423 ``bps=b,bps_rd=r,bps_wr=w`` 1424 Specify bandwidth throttling limits in bytes per second, either 1425 for all request types or for reads or writes only. Small values 1426 can lead to timeouts or hangs inside the guest. A safe minimum 1427 for disks is 2 MB/s. 1428 1429 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm`` 1430 Specify bursts in bytes per second, either for all request types 1431 or for reads or writes only. Bursts allow the guest I/O to spike 1432 above the limit temporarily. 1433 1434 ``iops=i,iops_rd=r,iops_wr=w`` 1435 Specify request rate limits in requests per second, either for 1436 all request types or for reads or writes only. 1437 1438 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm`` 1439 Specify bursts in requests per second, either for all request 1440 types or for reads or writes only. Bursts allow the guest I/O to 1441 spike above the limit temporarily. 1442 1443 ``iops_size=is`` 1444 Let every is bytes of a request count as a new request for iops 1445 throttling purposes. Use this option to prevent guests from 1446 circumventing iops limits by sending fewer but larger requests. 1447 1448 ``group=g`` 1449 Join a throttling quota group with given name g. All drives that 1450 are members of the same group are accounted for together. Use 1451 this option to prevent guests from circumventing throttling 1452 limits by using many small disks instead of a single larger 1453 disk. 1454 1455 By default, the ``cache.writeback=on`` mode is used. It will report 1456 data writes as completed as soon as the data is present in the host 1457 page cache. This is safe as long as your guest OS makes sure to 1458 correctly flush disk caches where needed. If your guest OS does not 1459 handle volatile disk write caches correctly and your host crashes or 1460 loses power, then the guest may experience data corruption. 1461 1462 For such guests, you should consider using ``cache.writeback=off``. 1463 This means that the host page cache will be used to read and write 1464 data, but write notification will be sent to the guest only after 1465 QEMU has made sure to flush each write to the disk. Be aware that 1466 this has a major impact on performance. 1467 1468 When using the ``-snapshot`` option, unsafe caching is always used. 1469 1470 Copy-on-read avoids accessing the same backing file sectors 1471 repeatedly and is useful when the backing file is over a slow 1472 network. By default copy-on-read is off. 1473 1474 Instead of ``-cdrom`` you can use: 1475 1476 .. parsed-literal:: 1477 1478 |qemu_system| -drive file=file,index=2,media=cdrom 1479 1480 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use: 1481 1482 .. parsed-literal:: 1483 1484 |qemu_system| -drive file=file,index=0,media=disk 1485 |qemu_system| -drive file=file,index=1,media=disk 1486 |qemu_system| -drive file=file,index=2,media=disk 1487 |qemu_system| -drive file=file,index=3,media=disk 1488 1489 You can open an image using pre-opened file descriptors from an fd 1490 set: 1491 1492 .. parsed-literal:: 1493 1494 |qemu_system| \\ 1495 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 1496 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 1497 -drive file=/dev/fdset/2,index=0,media=disk 1498 1499 You can connect a CDROM to the slave of ide0: 1500 1501 .. parsed-literal:: 1502 1503 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom 1504 1505 If you don't specify the "file=" argument, you define an empty 1506 drive: 1507 1508 .. parsed-literal:: 1509 1510 |qemu_system_x86| -drive if=ide,index=1,media=cdrom 1511 1512 Instead of ``-fda``, ``-fdb``, you can use: 1513 1514 .. parsed-literal:: 1515 1516 |qemu_system_x86| -drive file=file,index=0,if=floppy 1517 |qemu_system_x86| -drive file=file,index=1,if=floppy 1518 1519 By default, interface is "ide" and index is automatically 1520 incremented: 1521 1522 .. parsed-literal:: 1523 1524 |qemu_system_x86| -drive file=a -drive file=b" 1525 1526 is interpreted like: 1527 1528 .. parsed-literal:: 1529 1530 |qemu_system_x86| -hda a -hdb b 1531ERST 1532 1533DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1534 "-mtdblock file use 'file' as on-board Flash memory image\n", 1535 QEMU_ARCH_ALL) 1536SRST 1537``-mtdblock file`` 1538 Use file as on-board Flash memory image. 1539ERST 1540 1541DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1542 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1543SRST 1544``-sd file`` 1545 Use file as SecureDigital card image. 1546ERST 1547 1548DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1549 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1550SRST 1551``-pflash file`` 1552 Use file as a parallel flash image. 1553ERST 1554 1555DEF("snapshot", 0, QEMU_OPTION_snapshot, 1556 "-snapshot write to temporary files instead of disk image files\n", 1557 QEMU_ARCH_ALL) 1558SRST 1559``-snapshot`` 1560 Write to temporary files instead of disk image files. In this case, 1561 the raw disk image you use is not written back. You can however 1562 force the write back by pressing C-a s (see the :ref:`disk images` 1563 chapter in the System Emulation Users Guide). 1564ERST 1565 1566DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1567 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1568 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n" 1569 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1570 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1571 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1572 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1573 " [[,throttling.iops-size=is]]\n" 1574 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly=on]\n" 1575 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly=on]\n" 1576 "-fsdev synth,id=id\n", 1577 QEMU_ARCH_ALL) 1578 1579SRST 1580``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly=on][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]`` 1581 \ 1582``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly=on]`` 1583 \ 1584``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly=on]`` 1585 \ 1586``-fsdev synth,id=id[,readonly=on]`` 1587 Define a new file system device. Valid options are: 1588 1589 ``local`` 1590 Accesses to the filesystem are done by QEMU. 1591 1592 ``proxy`` 1593 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1594 1595 ``synth`` 1596 Synthetic filesystem, only used by QTests. 1597 1598 ``id=id`` 1599 Specifies identifier for this device. 1600 1601 ``path=path`` 1602 Specifies the export path for the file system device. Files 1603 under this path will be available to the 9p client on the guest. 1604 1605 ``security_model=security_model`` 1606 Specifies the security model to be used for this export path. 1607 Supported security models are "passthrough", "mapped-xattr", 1608 "mapped-file" and "none". In "passthrough" security model, files 1609 are stored using the same credentials as they are created on the 1610 guest. This requires QEMU to run as root. In "mapped-xattr" 1611 security model, some of the file attributes like uid, gid, mode 1612 bits and link target are stored as file attributes. For 1613 "mapped-file" these attributes are stored in the hidden 1614 .virtfs\_metadata directory. Directories exported by this 1615 security model cannot interact with other unix tools. "none" 1616 security model is same as passthrough except the sever won't 1617 report failures if it fails to set file attributes like 1618 ownership. Security model is mandatory only for local fsdriver. 1619 Other fsdrivers (like proxy) don't take security model as a 1620 parameter. 1621 1622 ``writeout=writeout`` 1623 This is an optional argument. The only supported value is 1624 "immediate". This means that host page cache will be used to 1625 read and write data but write notification will be sent to the 1626 guest only when the data has been reported as written by the 1627 storage subsystem. 1628 1629 ``readonly=on`` 1630 Enables exporting 9p share as a readonly mount for guests. By 1631 default read-write access is given. 1632 1633 ``socket=socket`` 1634 Enables proxy filesystem driver to use passed socket file for 1635 communicating with virtfs-proxy-helper(1). 1636 1637 ``sock_fd=sock_fd`` 1638 Enables proxy filesystem driver to use passed socket descriptor 1639 for communicating with virtfs-proxy-helper(1). Usually a helper 1640 like libvirt will create socketpair and pass one of the fds as 1641 sock\_fd. 1642 1643 ``fmode=fmode`` 1644 Specifies the default mode for newly created files on the host. 1645 Works only with security models "mapped-xattr" and 1646 "mapped-file". 1647 1648 ``dmode=dmode`` 1649 Specifies the default mode for newly created directories on the 1650 host. Works only with security models "mapped-xattr" and 1651 "mapped-file". 1652 1653 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w`` 1654 Specify bandwidth throttling limits in bytes per second, either 1655 for all request types or for reads or writes only. 1656 1657 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm`` 1658 Specify bursts in bytes per second, either for all request types 1659 or for reads or writes only. Bursts allow the guest I/O to spike 1660 above the limit temporarily. 1661 1662 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w`` 1663 Specify request rate limits in requests per second, either for 1664 all request types or for reads or writes only. 1665 1666 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm`` 1667 Specify bursts in requests per second, either for all request 1668 types or for reads or writes only. Bursts allow the guest I/O to 1669 spike above the limit temporarily. 1670 1671 ``throttling.iops-size=is`` 1672 Let every is bytes of a request count as a new request for iops 1673 throttling purposes. 1674 1675 -fsdev option is used along with -device driver "virtio-9p-...". 1676 1677``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag`` 1678 Options for virtio-9p-... driver are: 1679 1680 ``type`` 1681 Specifies the variant to be used. Supported values are "pci", 1682 "ccw" or "device", depending on the machine type. 1683 1684 ``fsdev=id`` 1685 Specifies the id value specified along with -fsdev option. 1686 1687 ``mount_tag=mount_tag`` 1688 Specifies the tag name to be used by the guest to mount this 1689 export point. 1690ERST 1691 1692DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1693 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1694 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1695 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly=on]\n" 1696 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly=on]\n" 1697 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n", 1698 QEMU_ARCH_ALL) 1699 1700SRST 1701``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly=on] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]`` 1702 \ 1703``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1704 \ 1705``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1706 \ 1707``-virtfs synth,mount_tag=mount_tag`` 1708 Define a new virtual filesystem device and expose it to the guest using 1709 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain 1710 directory on host is made directly accessible by guest as a pass-through 1711 file system by using the 9P network protocol for communication between 1712 host and guests, if desired even accessible, shared by several guests 1713 simultaniously. 1714 1715 Note that ``-virtfs`` is actually just a convenience shortcut for its 1716 generalized form ``-fsdev -device virtio-9p-pci``. 1717 1718 The general form of pass-through file system options are: 1719 1720 ``local`` 1721 Accesses to the filesystem are done by QEMU. 1722 1723 ``proxy`` 1724 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1725 1726 ``synth`` 1727 Synthetic filesystem, only used by QTests. 1728 1729 ``id=id`` 1730 Specifies identifier for the filesystem device 1731 1732 ``path=path`` 1733 Specifies the export path for the file system device. Files 1734 under this path will be available to the 9p client on the guest. 1735 1736 ``security_model=security_model`` 1737 Specifies the security model to be used for this export path. 1738 Supported security models are "passthrough", "mapped-xattr", 1739 "mapped-file" and "none". In "passthrough" security model, files 1740 are stored using the same credentials as they are created on the 1741 guest. This requires QEMU to run as root. In "mapped-xattr" 1742 security model, some of the file attributes like uid, gid, mode 1743 bits and link target are stored as file attributes. For 1744 "mapped-file" these attributes are stored in the hidden 1745 .virtfs\_metadata directory. Directories exported by this 1746 security model cannot interact with other unix tools. "none" 1747 security model is same as passthrough except the sever won't 1748 report failures if it fails to set file attributes like 1749 ownership. Security model is mandatory only for local fsdriver. 1750 Other fsdrivers (like proxy) don't take security model as a 1751 parameter. 1752 1753 ``writeout=writeout`` 1754 This is an optional argument. The only supported value is 1755 "immediate". This means that host page cache will be used to 1756 read and write data but write notification will be sent to the 1757 guest only when the data has been reported as written by the 1758 storage subsystem. 1759 1760 ``readonly=on`` 1761 Enables exporting 9p share as a readonly mount for guests. By 1762 default read-write access is given. 1763 1764 ``socket=socket`` 1765 Enables proxy filesystem driver to use passed socket file for 1766 communicating with virtfs-proxy-helper(1). Usually a helper like 1767 libvirt will create socketpair and pass one of the fds as 1768 sock\_fd. 1769 1770 ``sock_fd`` 1771 Enables proxy filesystem driver to use passed 'sock\_fd' as the 1772 socket descriptor for interfacing with virtfs-proxy-helper(1). 1773 1774 ``fmode=fmode`` 1775 Specifies the default mode for newly created files on the host. 1776 Works only with security models "mapped-xattr" and 1777 "mapped-file". 1778 1779 ``dmode=dmode`` 1780 Specifies the default mode for newly created directories on the 1781 host. Works only with security models "mapped-xattr" and 1782 "mapped-file". 1783 1784 ``mount_tag=mount_tag`` 1785 Specifies the tag name to be used by the guest to mount this 1786 export point. 1787 1788 ``multidevs=multidevs`` 1789 Specifies how to deal with multiple devices being shared with a 1790 9p export. Supported behaviours are either "remap", "forbid" or 1791 "warn". The latter is the default behaviour on which virtfs 9p 1792 expects only one device to be shared with the same export, and 1793 if more than one device is shared and accessed via the same 9p 1794 export then only a warning message is logged (once) by qemu on 1795 host side. In order to avoid file ID collisions on guest you 1796 should either create a separate virtfs export for each device to 1797 be shared with guests (recommended way) or you might use "remap" 1798 instead which allows you to share multiple devices with only one 1799 export instead, which is achieved by remapping the original 1800 inode numbers from host to guest in a way that would prevent 1801 such collisions. Remapping inodes in such use cases is required 1802 because the original device IDs from host are never passed and 1803 exposed on guest. Instead all files of an export shared with 1804 virtfs always share the same device id on guest. So two files 1805 with identical inode numbers but from actually different devices 1806 on host would otherwise cause a file ID collision and hence 1807 potential misbehaviours on guest. "forbid" on the other hand 1808 assumes like "warn" that only one device is shared by the same 1809 export, however it will not only log a warning message but also 1810 deny access to additional devices on guest. Note though that 1811 "forbid" does currently not block all possible file access 1812 operations (e.g. readdir() would still return entries from other 1813 devices). 1814ERST 1815 1816DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1817 "-iscsi [user=user][,password=password]\n" 1818 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1819 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1820 " [,timeout=timeout]\n" 1821 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1822 1823SRST 1824``-iscsi`` 1825 Configure iSCSI session parameters. 1826ERST 1827 1828DEFHEADING() 1829 1830DEFHEADING(USB convenience options:) 1831 1832DEF("usb", 0, QEMU_OPTION_usb, 1833 "-usb enable on-board USB host controller (if not enabled by default)\n", 1834 QEMU_ARCH_ALL) 1835SRST 1836``-usb`` 1837 Enable USB emulation on machine types with an on-board USB host 1838 controller (if not enabled by default). Note that on-board USB host 1839 controllers may not support USB 3.0. In this case 1840 ``-device qemu-xhci`` can be used instead on machines with PCI. 1841ERST 1842 1843DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1844 "-usbdevice name add the host or guest USB device 'name'\n", 1845 QEMU_ARCH_ALL) 1846SRST 1847``-usbdevice devname`` 1848 Add the USB device devname, and enable an on-board USB controller 1849 if possible and necessary (just like it can be done via 1850 ``-machine usb=on``). Note that this option is mainly intended for 1851 the user's convenience only. More fine-grained control can be 1852 achieved by selecting a USB host controller (if necessary) and the 1853 desired USB device via the ``-device`` option instead. For example, 1854 instead of using ``-usbdevice mouse`` it is possible to use 1855 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse 1856 to a USB 3.0 controller instead (at least on machines that support 1857 PCI and do not have an USB controller enabled by default yet). 1858 For more details, see the chapter about 1859 :ref:`Connecting USB devices` in the System Emulation Users Guide. 1860 Possible devices for devname are: 1861 1862 ``braille`` 1863 Braille device. This will use BrlAPI to display the braille 1864 output on a real or fake device (i.e. it also creates a 1865 corresponding ``braille`` chardev automatically beside the 1866 ``usb-braille`` USB device). 1867 1868 ``keyboard`` 1869 Standard USB keyboard. Will override the PS/2 keyboard (if present). 1870 1871 ``mouse`` 1872 Virtual Mouse. This will override the PS/2 mouse emulation when 1873 activated. 1874 1875 ``tablet`` 1876 Pointer device that uses absolute coordinates (like a 1877 touchscreen). This means QEMU is able to report the mouse 1878 position without having to grab the mouse. Also overrides the 1879 PS/2 mouse emulation when activated. 1880 1881 ``wacom-tablet`` 1882 Wacom PenPartner USB tablet. 1883 1884 1885ERST 1886 1887DEFHEADING() 1888 1889DEFHEADING(Display options:) 1890 1891DEF("display", HAS_ARG, QEMU_OPTION_display, 1892#if defined(CONFIG_SPICE) 1893 "-display spice-app[,gl=on|off]\n" 1894#endif 1895#if defined(CONFIG_SDL) 1896 "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off][,gl=on|core|es|off]\n" 1897 " [,grab-mod=<mod>][,show-cursor=on|off][,window-close=on|off]\n" 1898#endif 1899#if defined(CONFIG_GTK) 1900 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n" 1901 " [,show-cursor=on|off][,window-close=on|off]\n" 1902#endif 1903#if defined(CONFIG_VNC) 1904 "-display vnc=<display>[,<optargs>]\n" 1905#endif 1906#if defined(CONFIG_CURSES) 1907 "-display curses[,charset=<encoding>]\n" 1908#endif 1909#if defined(CONFIG_OPENGL) 1910 "-display egl-headless[,rendernode=<file>]\n" 1911#endif 1912#if defined(CONFIG_DBUS_DISPLAY) 1913 "-display dbus[,addr=<dbusaddr>]\n" 1914 " [,gl=on|core|es|off][,rendernode=<file>]\n" 1915#endif 1916 "-display none\n" 1917 " select display backend type\n" 1918 " The default display is equivalent to\n " 1919#if defined(CONFIG_GTK) 1920 "\"-display gtk\"\n" 1921#elif defined(CONFIG_SDL) 1922 "\"-display sdl\"\n" 1923#elif defined(CONFIG_COCOA) 1924 "\"-display cocoa\"\n" 1925#elif defined(CONFIG_VNC) 1926 "\"-vnc localhost:0,to=99,id=default\"\n" 1927#else 1928 "\"-display none\"\n" 1929#endif 1930 , QEMU_ARCH_ALL) 1931SRST 1932``-display type`` 1933 Select type of display to use. This option is a replacement for the 1934 old style -sdl/-curses/... options. Use ``-display help`` to list 1935 the available display types. Valid values for type are 1936 1937 ``spice-app[,gl=on|off]`` 1938 Start QEMU as a Spice server and launch the default Spice client 1939 application. The Spice server will redirect the serial consoles 1940 and QEMU monitors. (Since 4.0) 1941 1942 ``dbus`` 1943 Export the display over D-Bus interfaces. (Since 7.0) 1944 1945 The connection is registered with the "org.qemu" name (and queued when 1946 already owned). 1947 1948 ``addr=<dbusaddr>`` : D-Bus bus address to connect to. 1949 1950 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``. 1951 1952 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface 1953 will share framebuffers with DMABUF file descriptors). 1954 1955 ``sdl`` 1956 Display video output via SDL (usually in a separate graphics 1957 window; see the SDL documentation for other possibilities). 1958 Valid parameters are: 1959 1960 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling 1961 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be 1962 either ``lshift-lctrl-lalt`` or ``rctrl``. 1963 1964 ``alt_grab=on|off`` : Use Control+Alt+Shift-g to toggle mouse grabbing. 1965 This parameter is deprecated - use ``grab-mod`` instead. 1966 1967 ``ctrl_grab=on|off`` : Use Right-Control-g to toggle mouse grabbing. 1968 This parameter is deprecated - use ``grab-mod`` instead. 1969 1970 ``gl=on|off|core|es`` : Use OpenGL for displaying 1971 1972 ``show-cursor=on|off`` : Force showing the mouse cursor 1973 1974 ``window-close=on|off`` : Allow to quit qemu with window close button 1975 1976 ``gtk`` 1977 Display video output in a GTK window. This interface provides 1978 drop-down menus and other UI elements to configure and control 1979 the VM during runtime. Valid parameters are: 1980 1981 ``full-screen=on|off`` : Start in fullscreen mode 1982 1983 ``gl=on|off`` : Use OpenGL for displaying 1984 1985 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover 1986 1987 ``show-cursor=on|off`` : Force showing the mouse cursor 1988 1989 ``window-close=on|off`` : Allow to quit qemu with window close button 1990 1991 ``curses[,charset=<encoding>]`` 1992 Display video output via curses. For graphics device models 1993 which support a text mode, QEMU can display this output using a 1994 curses/ncurses interface. Nothing is displayed when the graphics 1995 device is in graphical mode or if the graphics device does not 1996 support a text mode. Generally only the VGA device models 1997 support text mode. The font charset used by the guest can be 1998 specified with the ``charset`` option, for example 1999 ``charset=CP850`` for IBM CP850 encoding. The default is 2000 ``CP437``. 2001 2002 ``egl-headless[,rendernode=<file>]`` 2003 Offload all OpenGL operations to a local DRI device. For any 2004 graphical display, this display needs to be paired with either 2005 VNC or SPICE displays. 2006 2007 ``vnc=<display>`` 2008 Start a VNC server on display <display> 2009 2010 ``none`` 2011 Do not display video output. The guest will still see an 2012 emulated graphics card, but its output will not be displayed to 2013 the QEMU user. This option differs from the -nographic option in 2014 that it only affects what is done with video output; -nographic 2015 also changes the destination of the serial and parallel port 2016 data. 2017ERST 2018 2019DEF("nographic", 0, QEMU_OPTION_nographic, 2020 "-nographic disable graphical output and redirect serial I/Os to console\n", 2021 QEMU_ARCH_ALL) 2022SRST 2023``-nographic`` 2024 Normally, if QEMU is compiled with graphical window support, it 2025 displays output such as guest graphics, guest console, and the QEMU 2026 monitor in a window. With this option, you can totally disable 2027 graphical output so that QEMU is a simple command line application. 2028 The emulated serial port is redirected on the console and muxed with 2029 the monitor (unless redirected elsewhere explicitly). Therefore, you 2030 can still use QEMU to debug a Linux kernel with a serial console. 2031 Use C-a h for help on switching between the console and monitor. 2032ERST 2033 2034DEF("curses", 0, QEMU_OPTION_curses, 2035 "-curses shorthand for -display curses\n", 2036 QEMU_ARCH_ALL) 2037SRST 2038``-curses`` 2039 Normally, if QEMU is compiled with graphical window support, it 2040 displays output such as guest graphics, guest console, and the QEMU 2041 monitor in a window. With this option, QEMU can display the VGA 2042 output when in text mode using a curses/ncurses interface. Nothing 2043 is displayed in graphical mode. 2044ERST 2045 2046DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 2047 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 2048 QEMU_ARCH_ALL) 2049SRST 2050``-alt-grab`` 2051 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that 2052 this also affects the special keys (for fullscreen, monitor-mode 2053 switching, etc). This option is deprecated - please use 2054 ``-display sdl,grab-mod=lshift-lctrl-lalt`` instead. 2055ERST 2056 2057DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 2058 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 2059 QEMU_ARCH_ALL) 2060SRST 2061``-ctrl-grab`` 2062 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this 2063 also affects the special keys (for fullscreen, monitor-mode 2064 switching, etc). This option is deprecated - please use 2065 ``-display sdl,grab-mod=rctrl`` instead. 2066ERST 2067 2068DEF("no-quit", 0, QEMU_OPTION_no_quit, 2069 "-no-quit disable SDL/GTK window close capability (deprecated)\n", QEMU_ARCH_ALL) 2070SRST 2071``-no-quit`` 2072 Disable window close capability (SDL and GTK only). This option is 2073 deprecated, please use ``-display ...,window-close=off`` instead. 2074ERST 2075 2076DEF("sdl", 0, QEMU_OPTION_sdl, 2077 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 2078SRST 2079``-sdl`` 2080 Enable SDL. 2081ERST 2082 2083DEF("spice", HAS_ARG, QEMU_OPTION_spice, 2084 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 2085 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 2086 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 2087 " [,x509-dh-key-file=<file>][,addr=addr]\n" 2088 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n" 2089 " [,tls-ciphers=<list>]\n" 2090 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 2091 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 2092 " [,sasl=on|off][,disable-ticketing=on|off]\n" 2093 " [,password=<string>][,password-secret=<secret-id>]\n" 2094 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 2095 " [,jpeg-wan-compression=[auto|never|always]]\n" 2096 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 2097 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n" 2098 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n" 2099 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 2100 " [,gl=[on|off]][,rendernode=<file>]\n" 2101 " enable spice\n" 2102 " at least one of {port, tls-port} is mandatory\n", 2103 QEMU_ARCH_ALL) 2104SRST 2105``-spice option[,option[,...]]`` 2106 Enable the spice remote desktop protocol. Valid options are 2107 2108 ``port=<nr>`` 2109 Set the TCP port spice is listening on for plaintext channels. 2110 2111 ``addr=<addr>`` 2112 Set the IP address spice is listening on. Default is any 2113 address. 2114 2115 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off`` 2116 Force using the specified IP version. 2117 2118 ``password=<string>`` 2119 Set the password you need to authenticate. 2120 2121 This option is deprecated and insecure because it leaves the 2122 password visible in the process listing. Use ``password-secret`` 2123 instead. 2124 2125 ``password-secret=<secret-id>`` 2126 Set the ID of the ``secret`` object containing the password 2127 you need to authenticate. 2128 2129 ``sasl=on|off`` 2130 Require that the client use SASL to authenticate with the spice. 2131 The exact choice of authentication method used is controlled 2132 from the system / user's SASL configuration file for the 'qemu' 2133 service. This is typically found in /etc/sasl2/qemu.conf. If 2134 running QEMU as an unprivileged user, an environment variable 2135 SASL\_CONF\_PATH can be used to make it search alternate 2136 locations for the service config. While some SASL auth methods 2137 can also provide data encryption (eg GSSAPI), it is recommended 2138 that SASL always be combined with the 'tls' and 'x509' settings 2139 to enable use of SSL and server certificates. This ensures a 2140 data encryption preventing compromise of authentication 2141 credentials. 2142 2143 ``disable-ticketing=on|off`` 2144 Allow client connects without authentication. 2145 2146 ``disable-copy-paste=on|off`` 2147 Disable copy paste between the client and the guest. 2148 2149 ``disable-agent-file-xfer=on|off`` 2150 Disable spice-vdagent based file-xfer between the client and the 2151 guest. 2152 2153 ``tls-port=<nr>`` 2154 Set the TCP port spice is listening on for encrypted channels. 2155 2156 ``x509-dir=<dir>`` 2157 Set the x509 file directory. Expects same filenames as -vnc 2158 $display,x509=$dir 2159 2160 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>`` 2161 The x509 file names can also be configured individually. 2162 2163 ``tls-ciphers=<list>`` 2164 Specify which ciphers to use. 2165 2166 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]`` 2167 Force specific channel to be used with or without TLS 2168 encryption. The options can be specified multiple times to 2169 configure multiple channels. The special name "default" can be 2170 used to set the default mode. For channels which are not 2171 explicitly forced into one mode the spice client is allowed to 2172 pick tls/plaintext as he pleases. 2173 2174 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]`` 2175 Configure image compression (lossless). Default is auto\_glz. 2176 2177 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]`` 2178 Configure wan image compression (lossy for slow links). Default 2179 is auto. 2180 2181 ``streaming-video=[off|all|filter]`` 2182 Configure video stream detection. Default is off. 2183 2184 ``agent-mouse=[on|off]`` 2185 Enable/disable passing mouse events via vdagent. Default is on. 2186 2187 ``playback-compression=[on|off]`` 2188 Enable/disable audio stream compression (using celt 0.5.1). 2189 Default is on. 2190 2191 ``seamless-migration=[on|off]`` 2192 Enable/disable spice seamless migration. Default is off. 2193 2194 ``gl=[on|off]`` 2195 Enable/disable OpenGL context. Default is off. 2196 2197 ``rendernode=<file>`` 2198 DRM render node for OpenGL rendering. If not specified, it will 2199 pick the first available. (Since 2.9) 2200ERST 2201 2202DEF("portrait", 0, QEMU_OPTION_portrait, 2203 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 2204 QEMU_ARCH_ALL) 2205SRST 2206``-portrait`` 2207 Rotate graphical output 90 deg left (only PXA LCD). 2208ERST 2209 2210DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 2211 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 2212 QEMU_ARCH_ALL) 2213SRST 2214``-rotate deg`` 2215 Rotate graphical output some deg left (only PXA LCD). 2216ERST 2217 2218DEF("vga", HAS_ARG, QEMU_OPTION_vga, 2219 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 2220 " select video card type\n", QEMU_ARCH_ALL) 2221SRST 2222``-vga type`` 2223 Select type of VGA card to emulate. Valid values for type are 2224 2225 ``cirrus`` 2226 Cirrus Logic GD5446 Video card. All Windows versions starting 2227 from Windows 95 should recognize and use this graphic card. For 2228 optimal performances, use 16 bit color depth in the guest and 2229 the host OS. (This card was the default before QEMU 2.2) 2230 2231 ``std`` 2232 Standard VGA card with Bochs VBE extensions. If your guest OS 2233 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if 2234 you want to use high resolution modes (>= 1280x1024x16) then you 2235 should use this option. (This card is the default since QEMU 2236 2.2) 2237 2238 ``vmware`` 2239 VMWare SVGA-II compatible adapter. Use it if you have 2240 sufficiently recent XFree86/XOrg server or Windows guest with a 2241 driver for this card. 2242 2243 ``qxl`` 2244 QXL paravirtual graphic card. It is VGA compatible (including 2245 VESA 2.0 VBE support). Works best with qxl guest drivers 2246 installed though. Recommended choice when using the spice 2247 protocol. 2248 2249 ``tcx`` 2250 (sun4m only) Sun TCX framebuffer. This is the default 2251 framebuffer for sun4m machines and offers both 8-bit and 24-bit 2252 colour depths at a fixed resolution of 1024x768. 2253 2254 ``cg3`` 2255 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit 2256 framebuffer for sun4m machines available in both 1024x768 2257 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people 2258 wishing to run older Solaris versions. 2259 2260 ``virtio`` 2261 Virtio VGA card. 2262 2263 ``none`` 2264 Disable VGA card. 2265ERST 2266 2267DEF("full-screen", 0, QEMU_OPTION_full_screen, 2268 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 2269SRST 2270``-full-screen`` 2271 Start in full screen. 2272ERST 2273 2274DEF("g", HAS_ARG, QEMU_OPTION_g , 2275 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 2276 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 2277SRST 2278``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]`` 2279 Set the initial graphical resolution and depth (PPC, SPARC only). 2280 2281 For PPC the default is 800x600x32. 2282 2283 For SPARC with the TCX graphics device, the default is 1024x768x8 2284 with the option of 1024x768x24. For cgthree, the default is 2285 1024x768x8 with the option of 1152x900x8 for people who wish to use 2286 OBP. 2287ERST 2288 2289DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 2290 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 2291SRST 2292``-vnc display[,option[,option[,...]]]`` 2293 Normally, if QEMU is compiled with graphical window support, it 2294 displays output such as guest graphics, guest console, and the QEMU 2295 monitor in a window. With this option, you can have QEMU listen on 2296 VNC display display and redirect the VGA display over the VNC 2297 session. It is very useful to enable the usb tablet device when 2298 using this option (option ``-device usb-tablet``). When using the 2299 VNC display, you must use the ``-k`` parameter to set the keyboard 2300 layout if you are not using en-us. Valid syntax for the display is 2301 2302 ``to=L`` 2303 With this option, QEMU will try next available VNC displays, 2304 until the number L, if the origianlly defined "-vnc display" is 2305 not available, e.g. port 5900+display is already used by another 2306 application. By default, to=0. 2307 2308 ``host:d`` 2309 TCP connections will only be allowed from host on display d. By 2310 convention the TCP port is 5900+d. Optionally, host can be 2311 omitted in which case the server will accept connections from 2312 any host. 2313 2314 ``unix:path`` 2315 Connections will be allowed over UNIX domain sockets where path 2316 is the location of a unix socket to listen for connections on. 2317 2318 ``none`` 2319 VNC is initialized but not started. The monitor ``change`` 2320 command can be used to later start the VNC server. 2321 2322 Following the display value there may be one or more option flags 2323 separated by commas. Valid options are 2324 2325 ``reverse=on|off`` 2326 Connect to a listening VNC client via a "reverse" connection. 2327 The client is specified by the display. For reverse network 2328 connections (host:d,``reverse``), the d argument is a TCP port 2329 number, not a display number. 2330 2331 ``websocket=on|off`` 2332 Opens an additional TCP listening port dedicated to VNC 2333 Websocket connections. If a bare websocket option is given, the 2334 Websocket port is 5700+display. An alternative port can be 2335 specified with the syntax ``websocket``\ =port. 2336 2337 If host is specified connections will only be allowed from this 2338 host. It is possible to control the websocket listen address 2339 independently, using the syntax ``websocket``\ =host:port. 2340 2341 If no TLS credentials are provided, the websocket connection 2342 runs in unencrypted mode. If TLS credentials are provided, the 2343 websocket connection requires encrypted client connections. 2344 2345 ``password=on|off`` 2346 Require that password based authentication is used for client 2347 connections. 2348 2349 The password must be set separately using the ``set_password`` 2350 command in the :ref:`QEMU monitor`. The 2351 syntax to change your password is: 2352 ``set_password <protocol> <password>`` where <protocol> could be 2353 either "vnc" or "spice". 2354 2355 If you would like to change <protocol> password expiration, you 2356 should use ``expire_password <protocol> <expiration-time>`` 2357 where expiration time could be one of the following options: 2358 now, never, +seconds or UNIX time of expiration, e.g. +60 to 2359 make password expire in 60 seconds, or 1335196800 to make 2360 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for 2361 this date and time). 2362 2363 You can also use keywords "now" or "never" for the expiration 2364 time to allow <protocol> password to expire immediately or never 2365 expire. 2366 2367 ``password-secret=<secret-id>`` 2368 Require that password based authentication is used for client 2369 connections, using the password provided by the ``secret`` 2370 object identified by ``secret-id``. 2371 2372 ``tls-creds=ID`` 2373 Provides the ID of a set of TLS credentials to use to secure the 2374 VNC server. They will apply to both the normal VNC server socket 2375 and the websocket socket (if enabled). Setting TLS credentials 2376 will cause the VNC server socket to enable the VeNCrypt auth 2377 mechanism. The credentials should have been previously created 2378 using the ``-object tls-creds`` argument. 2379 2380 ``tls-authz=ID`` 2381 Provides the ID of the QAuthZ authorization object against which 2382 the client's x509 distinguished name will validated. This object 2383 is only resolved at time of use, so can be deleted and recreated 2384 on the fly while the VNC server is active. If missing, it will 2385 default to denying access. 2386 2387 ``sasl=on|off`` 2388 Require that the client use SASL to authenticate with the VNC 2389 server. The exact choice of authentication method used is 2390 controlled from the system / user's SASL configuration file for 2391 the 'qemu' service. This is typically found in 2392 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, 2393 an environment variable SASL\_CONF\_PATH can be used to make it 2394 search alternate locations for the service config. While some 2395 SASL auth methods can also provide data encryption (eg GSSAPI), 2396 it is recommended that SASL always be combined with the 'tls' 2397 and 'x509' settings to enable use of SSL and server 2398 certificates. This ensures a data encryption preventing 2399 compromise of authentication credentials. See the 2400 :ref:`VNC security` section in the System Emulation Users Guide 2401 for details on using SASL authentication. 2402 2403 ``sasl-authz=ID`` 2404 Provides the ID of the QAuthZ authorization object against which 2405 the client's SASL username will validated. This object is only 2406 resolved at time of use, so can be deleted and recreated on the 2407 fly while the VNC server is active. If missing, it will default 2408 to denying access. 2409 2410 ``acl=on|off`` 2411 Legacy method for enabling authorization of clients against the 2412 x509 distinguished name and SASL username. It results in the 2413 creation of two ``authz-list`` objects with IDs of 2414 ``vnc.username`` and ``vnc.x509dname``. The rules for these 2415 objects must be configured with the HMP ACL commands. 2416 2417 This option is deprecated and should no longer be used. The new 2418 ``sasl-authz`` and ``tls-authz`` options are a replacement. 2419 2420 ``lossy=on|off`` 2421 Enable lossy compression methods (gradient, JPEG, ...). If this 2422 option is set, VNC client may receive lossy framebuffer updates 2423 depending on its encoding settings. Enabling this option can 2424 save a lot of bandwidth at the expense of quality. 2425 2426 ``non-adaptive=on|off`` 2427 Disable adaptive encodings. Adaptive encodings are enabled by 2428 default. An adaptive encoding will try to detect frequently 2429 updated screen regions, and send updates in these regions using 2430 a lossy encoding (like JPEG). This can be really helpful to save 2431 bandwidth when playing videos. Disabling adaptive encodings 2432 restores the original static behavior of encodings like Tight. 2433 2434 ``share=[allow-exclusive|force-shared|ignore]`` 2435 Set display sharing policy. 'allow-exclusive' allows clients to 2436 ask for exclusive access. As suggested by the rfb spec this is 2437 implemented by dropping other connections. Connecting multiple 2438 clients in parallel requires all clients asking for a shared 2439 session (vncviewer: -shared switch). This is the default. 2440 'force-shared' disables exclusive client access. Useful for 2441 shared desktop sessions, where you don't want someone forgetting 2442 specify -shared disconnect everybody else. 'ignore' completely 2443 ignores the shared flag and allows everybody connect 2444 unconditionally. Doesn't conform to the rfb spec but is 2445 traditional QEMU behavior. 2446 2447 ``key-delay-ms`` 2448 Set keyboard delay, for key down and key up events, in 2449 milliseconds. Default is 10. Keyboards are low-bandwidth 2450 devices, so this slowdown can help the device and guest to keep 2451 up and not lose events in case events are arriving in bulk. 2452 Possible causes for the latter are flaky network connections, or 2453 scripts for automated testing. 2454 2455 ``audiodev=audiodev`` 2456 Use the specified audiodev when the VNC client requests audio 2457 transmission. When not using an -audiodev argument, this option 2458 must be omitted, otherwise is must be present and specify a 2459 valid audiodev. 2460 2461 ``power-control=on|off`` 2462 Permit the remote client to issue shutdown, reboot or reset power 2463 control requests. 2464ERST 2465 2466ARCHHEADING(, QEMU_ARCH_I386) 2467 2468ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2469 2470DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2471 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2472 QEMU_ARCH_I386) 2473SRST 2474``-win2k-hack`` 2475 Use it when installing Windows 2000 to avoid a disk full bug. After 2476 Windows 2000 is installed, you no longer need this option (this 2477 option slows down the IDE transfers). 2478ERST 2479 2480DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2481 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2482 QEMU_ARCH_I386) 2483SRST 2484``-no-fd-bootchk`` 2485 Disable boot signature checking for floppy disks in BIOS. May be 2486 needed to boot from old floppy disks. 2487ERST 2488 2489DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2490 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2491SRST 2492``-no-acpi`` 2493 Disable ACPI (Advanced Configuration and Power Interface) support. 2494 Use it if your guest OS complains about ACPI problems (PC target 2495 machine only). 2496ERST 2497 2498DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2499 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2500SRST 2501``-no-hpet`` 2502 Disable HPET support. 2503ERST 2504 2505DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2506 "-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" 2507 " ACPI table description\n", QEMU_ARCH_I386) 2508SRST 2509``-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]...]`` 2510 Add ACPI table with specified header fields and context from 2511 specified files. For file=, take whole ACPI table from the specified 2512 files, including all ACPI headers (possible overridden by other 2513 options). For data=, only data portion of the table is used, all 2514 header information is specified in the command line. If a SLIC table 2515 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id 2516 fields will override the same in the RSDT and the FADT (a.k.a. 2517 FACP), in order to ensure the field matches required by the 2518 Microsoft SLIC spec and the ACPI spec. 2519ERST 2520 2521DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2522 "-smbios file=binary\n" 2523 " load SMBIOS entry from binary file\n" 2524 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2525 " [,uefi=on|off]\n" 2526 " specify SMBIOS type 0 fields\n" 2527 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2528 " [,uuid=uuid][,sku=str][,family=str]\n" 2529 " specify SMBIOS type 1 fields\n" 2530 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2531 " [,asset=str][,location=str]\n" 2532 " specify SMBIOS type 2 fields\n" 2533 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2534 " [,sku=str]\n" 2535 " specify SMBIOS type 3 fields\n" 2536 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2537 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n" 2538 " specify SMBIOS type 4 fields\n" 2539 "-smbios type=11[,value=str][,path=filename]\n" 2540 " specify SMBIOS type 11 fields\n" 2541 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2542 " [,asset=str][,part=str][,speed=%d]\n" 2543 " specify SMBIOS type 17 fields\n" 2544 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n" 2545 " specify SMBIOS type 41 fields\n", 2546 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2547SRST 2548``-smbios file=binary`` 2549 Load SMBIOS entry from binary file. 2550 2551``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]`` 2552 Specify SMBIOS type 0 fields 2553 2554``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]`` 2555 Specify SMBIOS type 1 fields 2556 2557``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]`` 2558 Specify SMBIOS type 2 fields 2559 2560``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]`` 2561 Specify SMBIOS type 3 fields 2562 2563``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str]`` 2564 Specify SMBIOS type 4 fields 2565 2566``-smbios type=11[,value=str][,path=filename]`` 2567 Specify SMBIOS type 11 fields 2568 2569 This argument can be repeated multiple times, and values are added in the order they are parsed. 2570 Applications intending to use OEM strings data are encouraged to use their application name as 2571 a prefix for the value string. This facilitates passing information for multiple applications 2572 concurrently. 2573 2574 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax 2575 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes. 2576 2577 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to 2578 the SMBIOS table in the order in which they appear. 2579 2580 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535 2581 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the 2582 guest. Instead it should be used as a indicator to inform the guest where to locate the real 2583 data set, for example, by specifying the serial ID of a block device. 2584 2585 An example passing three strings is 2586 2587 .. parsed-literal:: 2588 2589 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\ 2590 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\ 2591 path=/some/file/with/oemstringsdata.txt 2592 2593 In the guest OS this is visible with the ``dmidecode`` command 2594 2595 .. parsed-literal:: 2596 2597 $ dmidecode -t 11 2598 Handle 0x0E00, DMI type 11, 5 bytes 2599 OEM Strings 2600 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/ 2601 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os 2602 String 3: myapp:some extra data 2603 2604 2605``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]`` 2606 Specify SMBIOS type 17 fields 2607 2608``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]`` 2609 Specify SMBIOS type 41 fields 2610 2611 This argument can be repeated multiple times. Its main use is to allow network interfaces be created 2612 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface 2613 position on the PCI bus. 2614 2615 Here is an example of use: 2616 2617 .. parsed-literal:: 2618 2619 -netdev user,id=internet \\ 2620 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\ 2621 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev 2622 2623 In the guest OS, the device should then appear as ``eno1``: 2624 2625 ..parsed-literal:: 2626 2627 $ ip -brief l 2628 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP> 2629 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP> 2630 2631 Currently, the PCI device has to be attached to the root bus. 2632 2633ERST 2634 2635DEFHEADING() 2636 2637DEFHEADING(Network options:) 2638 2639DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2640#ifdef CONFIG_SLIRP 2641 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n" 2642 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2643 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2644 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2645 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2646#ifndef _WIN32 2647 "[,smb=dir[,smbserver=addr]]\n" 2648#endif 2649 " configure a user mode network backend with ID 'str',\n" 2650 " its DHCP server and optional services\n" 2651#endif 2652#ifdef _WIN32 2653 "-netdev tap,id=str,ifname=name\n" 2654 " configure a host TAP network backend with ID 'str'\n" 2655#else 2656 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2657 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2658 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2659 " [,poll-us=n]\n" 2660 " configure a host TAP network backend with ID 'str'\n" 2661 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2662 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2663 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2664 " to deconfigure it\n" 2665 " use '[down]script=no' to disable script execution\n" 2666 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2667 " configure it\n" 2668 " use 'fd=h' to connect to an already opened TAP interface\n" 2669 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2670 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2671 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2672 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2673 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2674 " use vhost=on to enable experimental in kernel accelerator\n" 2675 " (only has effect for virtio guests which use MSIX)\n" 2676 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2677 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2678 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2679 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2680 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n" 2681 " spent on busy polling for vhost net\n" 2682 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2683 " configure a host TAP network backend with ID 'str' that is\n" 2684 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2685 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2686#endif 2687#ifdef __linux__ 2688 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2689 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n" 2690 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n" 2691 " [,rxcookie=rxcookie][,offset=offset]\n" 2692 " configure a network backend with ID 'str' connected to\n" 2693 " an Ethernet over L2TPv3 pseudowire.\n" 2694 " Linux kernel 3.3+ as well as most routers can talk\n" 2695 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2696 " VM to a router and even VM to Host. It is a nearly-universal\n" 2697 " standard (RFC3931). Note - this implementation uses static\n" 2698 " pre-configured tunnels (same as the Linux kernel).\n" 2699 " use 'src=' to specify source address\n" 2700 " use 'dst=' to specify destination address\n" 2701 " use 'udp=on' to specify udp encapsulation\n" 2702 " use 'srcport=' to specify source udp port\n" 2703 " use 'dstport=' to specify destination udp port\n" 2704 " use 'ipv6=on' to force v6\n" 2705 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2706 " well as a weak security measure\n" 2707 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2708 " use 'txcookie=0x012345678' to specify a txcookie\n" 2709 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2710 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2711 " use 'pincounter=on' to work around broken counter handling in peer\n" 2712 " use 'offset=X' to add an extra offset between header and data\n" 2713#endif 2714 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2715 " configure a network backend to connect to another network\n" 2716 " using a socket connection\n" 2717 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2718 " configure a network backend to connect to a multicast maddr and port\n" 2719 " use 'localaddr=addr' to specify the host address to send packets from\n" 2720 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2721 " configure a network backend to connect to another network\n" 2722 " using an UDP tunnel\n" 2723#ifdef CONFIG_VDE 2724 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2725 " configure a network backend to connect to port 'n' of a vde switch\n" 2726 " running on host and listening for incoming connections on 'socketpath'.\n" 2727 " Use group 'groupname' and mode 'octalmode' to change default\n" 2728 " ownership and permissions for communication port.\n" 2729#endif 2730#ifdef CONFIG_NETMAP 2731 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2732 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2733 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2734 " netmap device, defaults to '/dev/netmap')\n" 2735#endif 2736#ifdef CONFIG_POSIX 2737 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2738 " configure a vhost-user network, backed by a chardev 'dev'\n" 2739#endif 2740#ifdef __linux__ 2741 "-netdev vhost-vdpa,id=str,vhostdev=/path/to/dev\n" 2742 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n" 2743#endif 2744 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2745 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2746DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2747 "-nic [tap|bridge|" 2748#ifdef CONFIG_SLIRP 2749 "user|" 2750#endif 2751#ifdef __linux__ 2752 "l2tpv3|" 2753#endif 2754#ifdef CONFIG_VDE 2755 "vde|" 2756#endif 2757#ifdef CONFIG_NETMAP 2758 "netmap|" 2759#endif 2760#ifdef CONFIG_POSIX 2761 "vhost-user|" 2762#endif 2763 "socket][,option][,...][mac=macaddr]\n" 2764 " initialize an on-board / default host NIC (using MAC address\n" 2765 " macaddr) and connect it to the given host network backend\n" 2766 "-nic none use it alone to have zero network devices (the default is to\n" 2767 " provided a 'user' network connection)\n", 2768 QEMU_ARCH_ALL) 2769DEF("net", HAS_ARG, QEMU_OPTION_net, 2770 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2771 " configure or create an on-board (or machine default) NIC and\n" 2772 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2773 "-net [" 2774#ifdef CONFIG_SLIRP 2775 "user|" 2776#endif 2777 "tap|" 2778 "bridge|" 2779#ifdef CONFIG_VDE 2780 "vde|" 2781#endif 2782#ifdef CONFIG_NETMAP 2783 "netmap|" 2784#endif 2785 "socket][,option][,option][,...]\n" 2786 " old way to initialize a host network interface\n" 2787 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2788SRST 2789``-nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]`` 2790 This option is a shortcut for configuring both the on-board 2791 (default) guest NIC hardware and the host network backend in one go. 2792 The host backend options are the same as with the corresponding 2793 ``-netdev`` options below. The guest NIC model can be set with 2794 ``model=modelname``. Use ``model=help`` to list the available device 2795 types. The hardware MAC address can be set with ``mac=macaddr``. 2796 2797 The following two example do exactly the same, to show how ``-nic`` 2798 can be used to shorten the command line length: 2799 2800 .. parsed-literal:: 2801 2802 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2803 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2804 2805``-nic none`` 2806 Indicate that no network devices should be configured. It is used to 2807 override the default configuration (default NIC with "user" host 2808 network backend) which is activated if no other networking options 2809 are provided. 2810 2811``-netdev user,id=id[,option][,option][,...]`` 2812 Configure user mode host network backend which requires no 2813 administrator privilege to run. Valid options are: 2814 2815 ``id=id`` 2816 Assign symbolic name for use in monitor commands. 2817 2818 ``ipv4=on|off and ipv6=on|off`` 2819 Specify that either IPv4 or IPv6 must be enabled. If neither is 2820 specified both protocols are enabled. 2821 2822 ``net=addr[/mask]`` 2823 Set IP network address the guest will see. Optionally specify 2824 the netmask, either in the form a.b.c.d or as number of valid 2825 top-most bits. Default is 10.0.2.0/24. 2826 2827 ``host=addr`` 2828 Specify the guest-visible address of the host. Default is the 2829 2nd IP in the guest network, i.e. x.x.x.2. 2830 2831 ``ipv6-net=addr[/int]`` 2832 Set IPv6 network address the guest will see (default is 2833 fec0::/64). The network prefix is given in the usual hexadecimal 2834 IPv6 address notation. The prefix size is optional, and is given 2835 as the number of valid top-most bits (default is 64). 2836 2837 ``ipv6-host=addr`` 2838 Specify the guest-visible IPv6 address of the host. Default is 2839 the 2nd IPv6 in the guest network, i.e. xxxx::2. 2840 2841 ``restrict=on|off`` 2842 If this option is enabled, the guest will be isolated, i.e. it 2843 will not be able to contact the host and no guest IP packets 2844 will be routed over the host to the outside. This option does 2845 not affect any explicitly set forwarding rules. 2846 2847 ``hostname=name`` 2848 Specifies the client hostname reported by the built-in DHCP 2849 server. 2850 2851 ``dhcpstart=addr`` 2852 Specify the first of the 16 IPs the built-in DHCP server can 2853 assign. Default is the 15th to 31st IP in the guest network, 2854 i.e. x.x.x.15 to x.x.x.31. 2855 2856 ``dns=addr`` 2857 Specify the guest-visible address of the virtual nameserver. The 2858 address must be different from the host address. Default is the 2859 3rd IP in the guest network, i.e. x.x.x.3. 2860 2861 ``ipv6-dns=addr`` 2862 Specify the guest-visible address of the IPv6 virtual 2863 nameserver. The address must be different from the host address. 2864 Default is the 3rd IP in the guest network, i.e. xxxx::3. 2865 2866 ``dnssearch=domain`` 2867 Provides an entry for the domain-search list sent by the 2868 built-in DHCP server. More than one domain suffix can be 2869 transmitted by specifying this option multiple times. If 2870 supported, this will cause the guest to automatically try to 2871 append the given domain suffix(es) in case a domain name can not 2872 be resolved. 2873 2874 Example: 2875 2876 .. parsed-literal:: 2877 2878 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2879 2880 ``domainname=domain`` 2881 Specifies the client domain name reported by the built-in DHCP 2882 server. 2883 2884 ``tftp=dir`` 2885 When using the user mode network stack, activate a built-in TFTP 2886 server. The files in dir will be exposed as the root of a TFTP 2887 server. The TFTP client on the guest must be configured in 2888 binary mode (use the command ``bin`` of the Unix TFTP client). 2889 2890 ``tftp-server-name=name`` 2891 In BOOTP reply, broadcast name as the "TFTP server name" 2892 (RFC2132 option 66). This can be used to advise the guest to 2893 load boot files or configurations from a different server than 2894 the host address. 2895 2896 ``bootfile=file`` 2897 When using the user mode network stack, broadcast file as the 2898 BOOTP filename. In conjunction with ``tftp``, this can be used 2899 to network boot a guest from a local directory. 2900 2901 Example (using pxelinux): 2902 2903 .. parsed-literal:: 2904 2905 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\ 2906 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2907 2908 ``smb=dir[,smbserver=addr]`` 2909 When using the user mode network stack, activate a built-in SMB 2910 server so that Windows OSes can access to the host files in 2911 ``dir`` transparently. The IP address of the SMB server can be 2912 set to addr. By default the 4th IP in the guest network is used, 2913 i.e. x.x.x.4. 2914 2915 In the guest Windows OS, the line: 2916 2917 :: 2918 2919 10.0.2.4 smbserver 2920 2921 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows 2922 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows 2923 NT/2000). 2924 2925 Then ``dir`` can be accessed in ``\\smbserver\qemu``. 2926 2927 Note that a SAMBA server must be installed on the host OS. 2928 2929 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport`` 2930 Redirect incoming TCP or UDP connections to the host port 2931 hostport to the guest IP address guestaddr on guest port 2932 guestport. If guestaddr is not specified, its value is x.x.x.15 2933 (default first address given by the built-in DHCP server). By 2934 specifying hostaddr, the rule can be bound to a specific host 2935 interface. If no connection type is set, TCP is used. This 2936 option can be given multiple times. 2937 2938 For example, to redirect host X11 connection from screen 1 to 2939 guest screen 0, use the following: 2940 2941 .. parsed-literal:: 2942 2943 # on the host 2944 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2945 # this host xterm should open in the guest X11 server 2946 xterm -display :1 2947 2948 To redirect telnet connections from host port 5555 to telnet 2949 port on the guest, use the following: 2950 2951 .. parsed-literal:: 2952 2953 # on the host 2954 |qemu_system| -nic user,hostfwd=tcp::5555-:23 2955 telnet localhost 5555 2956 2957 Then when you use on the host ``telnet localhost 5555``, you 2958 connect to the guest telnet server. 2959 2960 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command`` 2961 Forward guest TCP connections to the IP address server on port 2962 port to the character device dev or to a program executed by 2963 cmd:command which gets spawned for each connection. This option 2964 can be given multiple times. 2965 2966 You can either use a chardev directly and have that one used 2967 throughout QEMU's lifetime, like in the following example: 2968 2969 .. parsed-literal:: 2970 2971 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2972 # the guest accesses it 2973 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2974 2975 Or you can execute a command on every TCP connection established 2976 by the guest, so that QEMU behaves similar to an inetd process 2977 for that virtual server: 2978 2979 .. parsed-literal:: 2980 2981 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2982 # and connect the TCP stream to its stdin/stdout 2983 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2984 2985``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` 2986 Configure a host TAP network backend with ID id. 2987 2988 Use the network script file to configure it and the network script 2989 dfile to deconfigure it. If name is not provided, the OS 2990 automatically provides one. The default network configure script is 2991 ``/etc/qemu-ifup`` and the default network deconfigure script is 2992 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to 2993 disable script execution. 2994 2995 If running QEMU as an unprivileged user, use the network helper 2996 to configure the TAP interface and attach it to the bridge. 2997 The default network helper executable is 2998 ``/path/to/qemu-bridge-helper`` and the default bridge device is 2999 ``br0``. 3000 3001 ``fd``\ =h can be used to specify the handle of an already opened 3002 host TAP interface. 3003 3004 Examples: 3005 3006 .. parsed-literal:: 3007 3008 #launch a QEMU instance with the default network script 3009 |qemu_system| linux.img -nic tap 3010 3011 .. parsed-literal:: 3012 3013 #launch a QEMU instance with two NICs, each one connected 3014 #to a TAP device 3015 |qemu_system| linux.img \\ 3016 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\ 3017 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 3018 3019 .. parsed-literal:: 3020 3021 #launch a QEMU instance with the default network helper to 3022 #connect a TAP device to bridge br0 3023 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3024 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 3025 3026``-netdev bridge,id=id[,br=bridge][,helper=helper]`` 3027 Connect a host TAP network interface to a host bridge device. 3028 3029 Use the network helper helper to configure the TAP interface and 3030 attach it to the bridge. The default network helper executable is 3031 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3032 ``br0``. 3033 3034 Examples: 3035 3036 .. parsed-literal:: 3037 3038 #launch a QEMU instance with the default network helper to 3039 #connect a TAP device to bridge br0 3040 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 3041 3042 .. parsed-literal:: 3043 3044 #launch a QEMU instance with the default network helper to 3045 #connect a TAP device to bridge qemubr0 3046 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 3047 3048``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]`` 3049 This host network backend can be used to connect the guest's network 3050 to another QEMU virtual machine using a TCP socket connection. If 3051 ``listen`` is specified, QEMU waits for incoming connections on port 3052 (host is optional). ``connect`` is used to connect to another QEMU 3053 instance using the ``listen`` option. ``fd``\ =h specifies an 3054 already opened TCP socket. 3055 3056 Example: 3057 3058 .. parsed-literal:: 3059 3060 # launch a first QEMU instance 3061 |qemu_system| linux.img \\ 3062 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3063 -netdev socket,id=n1,listen=:1234 3064 # connect the network of this instance to the network of the first instance 3065 |qemu_system| linux.img \\ 3066 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3067 -netdev socket,id=n2,connect=127.0.0.1:1234 3068 3069``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]`` 3070 Configure a socket host network backend to share the guest's network 3071 traffic with another QEMU virtual machines using a UDP multicast 3072 socket, effectively making a bus for every QEMU with same multicast 3073 address maddr and port. NOTES: 3074 3075 1. Several QEMU can be running on different hosts and share same bus 3076 (assuming correct multicast setup for these hosts). 3077 3078 2. mcast support is compatible with User Mode Linux (argument 3079 ``ethN=mcast``), see http://user-mode-linux.sf.net. 3080 3081 3. Use ``fd=h`` to specify an already opened UDP multicast socket. 3082 3083 Example: 3084 3085 .. parsed-literal:: 3086 3087 # launch one QEMU instance 3088 |qemu_system| linux.img \\ 3089 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3090 -netdev socket,id=n1,mcast=230.0.0.1:1234 3091 # launch another QEMU instance on same "bus" 3092 |qemu_system| linux.img \\ 3093 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3094 -netdev socket,id=n2,mcast=230.0.0.1:1234 3095 # launch yet another QEMU instance on same "bus" 3096 |qemu_system| linux.img \\ 3097 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\ 3098 -netdev socket,id=n3,mcast=230.0.0.1:1234 3099 3100 Example (User Mode Linux compat.): 3101 3102 .. parsed-literal:: 3103 3104 # launch QEMU instance (note mcast address selected is UML's default) 3105 |qemu_system| linux.img \\ 3106 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3107 -netdev socket,id=n1,mcast=239.192.168.1:1102 3108 # launch UML 3109 /path/to/linux ubd0=/path/to/root_fs eth0=mcast 3110 3111 Example (send packets from host's 1.2.3.4): 3112 3113 .. parsed-literal:: 3114 3115 |qemu_system| linux.img \\ 3116 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3117 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 3118 3119``-netdev l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6=on|off][,udp=on|off][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]`` 3120 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931) 3121 is a popular protocol to transport Ethernet (and other Layer 2) data 3122 frames between two systems. It is present in routers, firewalls and 3123 the Linux kernel (from version 3.3 onwards). 3124 3125 This transport allows a VM to communicate to another VM, router or 3126 firewall directly. 3127 3128 ``src=srcaddr`` 3129 source address (mandatory) 3130 3131 ``dst=dstaddr`` 3132 destination address (mandatory) 3133 3134 ``udp`` 3135 select udp encapsulation (default is ip). 3136 3137 ``srcport=srcport`` 3138 source udp port. 3139 3140 ``dstport=dstport`` 3141 destination udp port. 3142 3143 ``ipv6`` 3144 force v6, otherwise defaults to v4. 3145 3146 ``rxcookie=rxcookie``; \ ``txcookie=txcookie`` 3147 Cookies are a weak form of security in the l2tpv3 specification. 3148 Their function is mostly to prevent misconfiguration. By default 3149 they are 32 bit. 3150 3151 ``cookie64`` 3152 Set cookie size to 64 bit instead of the default 32 3153 3154 ``counter=off`` 3155 Force a 'cut-down' L2TPv3 with no counter as in 3156 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 3157 3158 ``pincounter=on`` 3159 Work around broken counter handling in peer. This may also help 3160 on networks which have packet reorder. 3161 3162 ``offset=offset`` 3163 Add an extra offset between header and data 3164 3165 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to 3166 the bridge br-lan on the remote Linux host 1.2.3.4: 3167 3168 .. parsed-literal:: 3169 3170 # Setup tunnel on linux host using raw ip as encapsulation 3171 # on 1.2.3.4 3172 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\ 3173 encap udp udp_sport 16384 udp_dport 16384 3174 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\ 3175 0xFFFFFFFF peer_session_id 0xFFFFFFFF 3176 ifconfig vmtunnel0 mtu 1500 3177 ifconfig vmtunnel0 up 3178 brctl addif br-lan vmtunnel0 3179 3180 3181 # on 4.3.2.1 3182 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 3183 3184 |qemu_system| linux.img -device e1000,netdev=n1 \\ 3185 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 3186 3187``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]`` 3188 Configure VDE backend to connect to PORT n of a vde switch running 3189 on host and listening for incoming connections on socketpath. Use 3190 GROUP groupname and MODE octalmode to change default ownership and 3191 permissions for communication port. This option is only available if 3192 QEMU has been compiled with vde support enabled. 3193 3194 Example: 3195 3196 .. parsed-literal:: 3197 3198 # launch vde switch 3199 vde_switch -F -sock /tmp/myswitch 3200 # launch QEMU instance 3201 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch 3202 3203``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` 3204 Establish a vhost-user netdev, backed by a chardev id. The chardev 3205 should be a unix domain socket backed one. The vhost-user uses a 3206 specifically defined protocol to pass vhost ioctl replacement 3207 messages to an application on the other end of the socket. On 3208 non-MSIX guests, the feature can be forced with vhostforce. Use 3209 'queues=n' to specify the number of queues to be created for 3210 multiqueue vhost-user. 3211 3212 Example: 3213 3214 :: 3215 3216 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 3217 -numa node,memdev=mem \ 3218 -chardev socket,id=chr0,path=/path/to/socket \ 3219 -netdev type=vhost-user,id=net0,chardev=chr0 \ 3220 -device virtio-net-pci,netdev=net0 3221 3222``-netdev vhost-vdpa,vhostdev=/path/to/dev`` 3223 Establish a vhost-vdpa netdev. 3224 3225 vDPA device is a device that uses a datapath which complies with 3226 the virtio specifications with a vendor specific control path. 3227 vDPA devices can be both physically located on the hardware or 3228 emulated by software. 3229 3230``-netdev hubport,id=id,hubid=hubid[,netdev=nd]`` 3231 Create a hub port on the emulated hub with ID hubid. 3232 3233 The hubport netdev lets you connect a NIC to a QEMU emulated hub 3234 instead of a single netdev. Alternatively, you can also connect the 3235 hubport to another netdev with ID nd by using the ``netdev=nd`` 3236 option. 3237 3238``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]`` 3239 Legacy option to configure or create an on-board (or machine 3240 default) Network Interface Card(NIC) and connect it either to the 3241 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd. 3242 If model is omitted, then the default NIC model associated with the 3243 machine type is used. Note that the default NIC model may change in 3244 future QEMU releases, so it is highly recommended to always specify 3245 a model. Optionally, the MAC address can be changed to mac, the 3246 device address set to addr (PCI cards only), and a name can be 3247 assigned for use in monitor commands. Optionally, for PCI cards, you 3248 can specify the number v of MSI-X vectors that the card should have; 3249 this option currently only affects virtio cards; set v = 0 to 3250 disable MSI-X. If no ``-net`` option is specified, a single NIC is 3251 created. QEMU can emulate several different models of network card. 3252 Use ``-net nic,model=help`` for a list of available devices for your 3253 target. 3254 3255``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]`` 3256 Configure a host network backend (with the options corresponding to 3257 the same ``-netdev`` option) and connect it to the emulated hub 0 3258 (the default hub). Use name to specify the name of the hub port. 3259ERST 3260 3261DEFHEADING() 3262 3263DEFHEADING(Character device options:) 3264 3265DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 3266 "-chardev help\n" 3267 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3268 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n" 3269 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" 3270 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 3271 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" 3272 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" 3273 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 3274 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n" 3275 " [,logfile=PATH][,logappend=on|off]\n" 3276 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3277 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 3278 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3279 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 3280 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3281 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3282#ifdef _WIN32 3283 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3284 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3285#else 3286 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3287 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 3288#endif 3289#ifdef CONFIG_BRLAPI 3290 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3291#endif 3292#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 3293 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 3294 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3295 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3296#endif 3297#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 3298 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3299 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3300#endif 3301#if defined(CONFIG_SPICE) 3302 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3303 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3304#endif 3305 , QEMU_ARCH_ALL 3306) 3307 3308SRST 3309The general form of a character device option is: 3310 3311``-chardev backend,id=id[,mux=on|off][,options]`` 3312 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, 3313 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, 3314 ``pty``, ``stdio``, ``braille``, ``tty``, ``parallel``, ``parport``, 3315 ``spicevmc``, ``spiceport``. The specific backend will determine the 3316 applicable options. 3317 3318 Use ``-chardev help`` to print all available chardev backend types. 3319 3320 All devices must have an id, which can be any string up to 127 3321 characters long. It is used to uniquely identify this device in 3322 other command line directives. 3323 3324 A character device may be used in multiplexing mode by multiple 3325 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is 3326 a "1:N" device, and here the "1" end is your specified chardev 3327 backend, and the "N" end is the various parts of QEMU that can talk 3328 to a chardev. If you create a chardev with ``id=myid`` and 3329 ``mux=on``, QEMU will create a multiplexer with your specified ID, 3330 and you can then configure multiple front ends to use that chardev 3331 ID for their input/output. Up to four different front ends can be 3332 connected to a single multiplexed chardev. (Without multiplexing 3333 enabled, a chardev can only be used by a single front end.) For 3334 instance you could use this to allow a single stdio chardev to be 3335 used by two serial ports and the QEMU monitor: 3336 3337 :: 3338 3339 -chardev stdio,mux=on,id=char0 \ 3340 -mon chardev=char0,mode=readline \ 3341 -serial chardev:char0 \ 3342 -serial chardev:char0 3343 3344 You can have more than one multiplexer in a system configuration; 3345 for instance you could have a TCP port multiplexed between UART 0 3346 and UART 1, and stdio multiplexed between the QEMU monitor and a 3347 parallel port: 3348 3349 :: 3350 3351 -chardev stdio,mux=on,id=char0 \ 3352 -mon chardev=char0,mode=readline \ 3353 -parallel chardev:char0 \ 3354 -chardev tcp,...,mux=on,id=char1 \ 3355 -serial chardev:char1 \ 3356 -serial chardev:char1 3357 3358 When you're using a multiplexed character device, some escape 3359 sequences are interpreted in the input. See the chapter about 3360 :ref:`keys in the character backend multiplexer` in the 3361 System Emulation Users Guide for more details. 3362 3363 Note that some other command line options may implicitly create 3364 multiplexed character backends; for instance ``-serial mon:stdio`` 3365 creates a multiplexed stdio backend connected to the serial port and 3366 the QEMU monitor, and ``-nographic`` also multiplexes the console 3367 and the monitor to stdio. 3368 3369 There is currently no support for multiplexing in the other 3370 direction (where a single QEMU front end takes input and output from 3371 multiple chardevs). 3372 3373 Every backend supports the ``logfile`` option, which supplies the 3374 path to a file to record all data transmitted via the backend. The 3375 ``logappend`` option controls whether the log file will be truncated 3376 or appended to when opened. 3377 3378The available backends are: 3379 3380``-chardev null,id=id`` 3381 A void device. This device will not emit any data, and will drop any 3382 data it receives. The null backend does not take any options. 3383 3384``-chardev socket,id=id[,TCP options or unix options][,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,tls-creds=id][,tls-authz=id]`` 3385 Create a two-way stream socket, which can be either a TCP or a unix 3386 socket. A unix socket will be created if ``path`` is specified. 3387 Behaviour is undefined if TCP options are specified for a unix 3388 socket. 3389 3390 ``server=on|off`` specifies that the socket shall be a listening socket. 3391 3392 ``wait=on|off`` specifies that QEMU should not block waiting for a client 3393 to connect to a listening socket. 3394 3395 ``telnet=on|off`` specifies that traffic on the socket should interpret 3396 telnet escape sequences. 3397 3398 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for 3399 communication. 3400 3401 ``reconnect`` sets the timeout for reconnecting on non-server 3402 sockets when the remote end goes away. qemu will delay this many 3403 seconds and then attempt to reconnect. Zero disables reconnecting, 3404 and is the default. 3405 3406 ``tls-creds`` requests enablement of the TLS protocol for 3407 encryption, and specifies the id of the TLS credentials to use for 3408 the handshake. The credentials must be previously created with the 3409 ``-object tls-creds`` argument. 3410 3411 ``tls-auth`` provides the ID of the QAuthZ authorization object 3412 against which the client's x509 distinguished name will be 3413 validated. This object is only resolved at time of use, so can be 3414 deleted and recreated on the fly while the chardev server is active. 3415 If missing, it will default to denying access. 3416 3417 TCP and unix socket options are given below: 3418 3419 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]`` 3420 ``host`` for a listening socket specifies the local address to 3421 be bound. For a connecting socket species the remote host to 3422 connect to. ``host`` is optional for listening sockets. If not 3423 specified it defaults to ``0.0.0.0``. 3424 3425 ``port`` for a listening socket specifies the local port to be 3426 bound. For a connecting socket specifies the port on the remote 3427 host to connect to. ``port`` can be given as either a port 3428 number or a service name. ``port`` is required. 3429 3430 ``to`` is only relevant to listening sockets. If it is 3431 specified, and ``port`` cannot be bound, QEMU will attempt to 3432 bind to subsequent ports up to and including ``to`` until it 3433 succeeds. ``to`` must be specified as a port number. 3434 3435 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 3436 or IPv6 must be used. If neither is specified the socket may 3437 use either protocol. 3438 3439 ``nodelay=on|off`` disables the Nagle algorithm. 3440 3441 ``unix options: path=path[,abstract=on|off][,tight=on|off]`` 3442 ``path`` specifies the local path of the unix socket. ``path`` 3443 is required. 3444 ``abstract=on|off`` specifies the use of the abstract socket namespace, 3445 rather than the filesystem. Optional, defaults to false. 3446 ``tight=on|off`` sets the socket length of abstract sockets to their minimum, 3447 rather than the full sun_path length. Optional, defaults to true. 3448 3449``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4=on|off][,ipv6=on|off]`` 3450 Sends all traffic from the guest to a remote host over UDP. 3451 3452 ``host`` specifies the remote host to connect to. If not specified 3453 it defaults to ``localhost``. 3454 3455 ``port`` specifies the port on the remote host to connect to. 3456 ``port`` is required. 3457 3458 ``localaddr`` specifies the local address to bind to. If not 3459 specified it defaults to ``0.0.0.0``. 3460 3461 ``localport`` specifies the local port to bind to. If not specified 3462 any available local port will be used. 3463 3464 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used. 3465 If neither is specified the device may use either protocol. 3466 3467``-chardev msmouse,id=id`` 3468 Forward QEMU's emulated msmouse events to the guest. ``msmouse`` 3469 does not take any options. 3470 3471``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` 3472 Connect to a QEMU text console. ``vc`` may optionally be given a 3473 specific size. 3474 3475 ``width`` and ``height`` specify the width and height respectively 3476 of the console, in pixels. 3477 3478 ``cols`` and ``rows`` specify that the console be sized to fit a 3479 text console with the given dimensions. 3480 3481``-chardev ringbuf,id=id[,size=size]`` 3482 Create a ring buffer with fixed size ``size``. size must be a power 3483 of two and defaults to ``64K``. 3484 3485``-chardev file,id=id,path=path`` 3486 Log all traffic received from the guest to a file. 3487 3488 ``path`` specifies the path of the file to be opened. This file will 3489 be created if it does not already exist, and overwritten if it does. 3490 ``path`` is required. 3491 3492``-chardev pipe,id=id,path=path`` 3493 Create a two-way connection to the guest. The behaviour differs 3494 slightly between Windows hosts and other hosts: 3495 3496 On Windows, a single duplex pipe will be created at 3497 ``\\.pipe\path``. 3498 3499 On other hosts, 2 pipes will be created called ``path.in`` and 3500 ``path.out``. Data written to ``path.in`` will be received by the 3501 guest. Data written by the guest can be read from ``path.out``. QEMU 3502 will not create these fifos, and requires them to be present. 3503 3504 ``path`` forms part of the pipe path as described above. ``path`` is 3505 required. 3506 3507``-chardev console,id=id`` 3508 Send traffic from the guest to QEMU's standard output. ``console`` 3509 does not take any options. 3510 3511 ``console`` is only available on Windows hosts. 3512 3513``-chardev serial,id=id,path=path`` 3514 Send traffic from the guest to a serial device on the host. 3515 3516 On Unix hosts serial will actually accept any tty device, not only 3517 serial lines. 3518 3519 ``path`` specifies the name of the serial device to open. 3520 3521``-chardev pty,id=id`` 3522 Create a new pseudo-terminal on the host and connect to it. ``pty`` 3523 does not take any options. 3524 3525 ``pty`` is not available on Windows hosts. 3526 3527``-chardev stdio,id=id[,signal=on|off]`` 3528 Connect to standard input and standard output of the QEMU process. 3529 3530 ``signal`` controls if signals are enabled on the terminal, that 3531 includes exiting QEMU with the key sequence Control-c. This option 3532 is enabled by default, use ``signal=off`` to disable it. 3533 3534``-chardev braille,id=id`` 3535 Connect to a local BrlAPI server. ``braille`` does not take any 3536 options. 3537 3538``-chardev tty,id=id,path=path`` 3539 ``tty`` is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD 3540 and DragonFlyBSD hosts. It is an alias for ``serial``. 3541 3542 ``path`` specifies the path to the tty. ``path`` is required. 3543 3544``-chardev parallel,id=id,path=path`` 3545 \ 3546``-chardev parport,id=id,path=path`` 3547 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD 3548 hosts. 3549 3550 Connect to a local parallel port. 3551 3552 ``path`` specifies the path to the parallel port device. ``path`` is 3553 required. 3554 3555``-chardev spicevmc,id=id,debug=debug,name=name`` 3556 ``spicevmc`` is only available when spice support is built in. 3557 3558 ``debug`` debug level for spicevmc 3559 3560 ``name`` name of spice channel to connect to 3561 3562 Connect to a spice virtual machine channel, such as vdiport. 3563 3564``-chardev spiceport,id=id,debug=debug,name=name`` 3565 ``spiceport`` is only available when spice support is built in. 3566 3567 ``debug`` debug level for spicevmc 3568 3569 ``name`` name of spice port to connect to 3570 3571 Connect to a spice port, allowing a Spice client to handle the 3572 traffic identified by a name (preferably a fqdn). 3573ERST 3574 3575DEFHEADING() 3576 3577#ifdef CONFIG_TPM 3578DEFHEADING(TPM device options:) 3579 3580DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3581 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3582 " use path to provide path to a character device; default is /dev/tpm0\n" 3583 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3584 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3585 "-tpmdev emulator,id=id,chardev=dev\n" 3586 " configure the TPM device using chardev backend\n", 3587 QEMU_ARCH_ALL) 3588SRST 3589The general form of a TPM device option is: 3590 3591``-tpmdev backend,id=id[,options]`` 3592 The specific backend type will determine the applicable options. The 3593 ``-tpmdev`` option creates the TPM backend and requires a 3594 ``-device`` option that specifies the TPM frontend interface model. 3595 3596 Use ``-tpmdev help`` to print all available TPM backend types. 3597 3598The available backends are: 3599 3600``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path`` 3601 (Linux-host only) Enable access to the host's TPM using the 3602 passthrough driver. 3603 3604 ``path`` specifies the path to the host's TPM device, i.e., on a 3605 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by 3606 default ``/dev/tpm0`` is used. 3607 3608 ``cancel-path`` specifies the path to the host TPM device's sysfs 3609 entry allowing for cancellation of an ongoing TPM command. 3610 ``cancel-path`` is optional and by default QEMU will search for the 3611 sysfs entry to use. 3612 3613 Some notes about using the host's TPM with the passthrough driver: 3614 3615 The TPM device accessed by the passthrough driver must not be used 3616 by any other application on the host. 3617 3618 Since the host's firmware (BIOS/UEFI) has already initialized the 3619 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize 3620 the TPM again and may therefore not show a TPM-specific menu that 3621 would otherwise allow the user to configure the TPM, e.g., allow the 3622 user to enable/disable or activate/deactivate the TPM. Further, if 3623 TPM ownership is released from within a VM then the host's TPM will 3624 get disabled and deactivated. To enable and activate the TPM again 3625 afterwards, the host has to be rebooted and the user is required to 3626 enter the firmware's menu to enable and activate the TPM. If the TPM 3627 is left disabled and/or deactivated most TPM commands will fail. 3628 3629 To create a passthrough TPM use the following two options: 3630 3631 :: 3632 3633 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3634 3635 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by 3636 ``tpmdev=tpm0`` in the device option. 3637 3638``-tpmdev emulator,id=id,chardev=dev`` 3639 (Linux-host only) Enable access to a TPM emulator using Unix domain 3640 socket based chardev backend. 3641 3642 ``chardev`` specifies the unique ID of a character device backend 3643 that provides connection to the software TPM server. 3644 3645 To create a TPM emulator backend device with chardev socket backend: 3646 3647 :: 3648 3649 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3650ERST 3651 3652DEFHEADING() 3653 3654#endif 3655 3656DEFHEADING(Linux/Multiboot boot specific:) 3657SRST 3658When using these options, you can use a given Linux or Multiboot kernel 3659without installing it in the disk image. It can be useful for easier 3660testing of various kernels. 3661 3662 3663ERST 3664 3665DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3666 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3667SRST 3668``-kernel bzImage`` 3669 Use bzImage as kernel image. The kernel can be either a Linux kernel 3670 or in multiboot format. 3671ERST 3672 3673DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3674 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3675SRST 3676``-append cmdline`` 3677 Use cmdline as kernel command line 3678ERST 3679 3680DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3681 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3682SRST 3683``-initrd file`` 3684 Use file as initial ram disk. 3685 3686``-initrd "file1 arg=foo,file2"`` 3687 This syntax is only available with multiboot. 3688 3689 Use file1 and file2 as modules and pass arg=foo as parameter to the 3690 first module. 3691ERST 3692 3693DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3694 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3695SRST 3696``-dtb file`` 3697 Use file as a device tree binary (dtb) image and pass it to the 3698 kernel on boot. 3699ERST 3700 3701DEFHEADING() 3702 3703DEFHEADING(Debug/Expert options:) 3704 3705DEF("compat", HAS_ARG, QEMU_OPTION_compat, 3706 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n" 3707 " Policy for handling deprecated management interfaces\n" 3708 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n" 3709 " Policy for handling unstable management interfaces\n", 3710 QEMU_ARCH_ALL) 3711SRST 3712``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]`` 3713 Set policy for handling deprecated management interfaces (experimental): 3714 3715 ``deprecated-input=accept`` (default) 3716 Accept deprecated commands and arguments 3717 ``deprecated-input=reject`` 3718 Reject deprecated commands and arguments 3719 ``deprecated-input=crash`` 3720 Crash on deprecated commands and arguments 3721 ``deprecated-output=accept`` (default) 3722 Emit deprecated command results and events 3723 ``deprecated-output=hide`` 3724 Suppress deprecated command results and events 3725 3726 Limitation: covers only syntactic aspects of QMP. 3727 3728``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]`` 3729 Set policy for handling unstable management interfaces (experimental): 3730 3731 ``unstable-input=accept`` (default) 3732 Accept unstable commands and arguments 3733 ``unstable-input=reject`` 3734 Reject unstable commands and arguments 3735 ``unstable-input=crash`` 3736 Crash on unstable commands and arguments 3737 ``unstable-output=accept`` (default) 3738 Emit unstable command results and events 3739 ``unstable-output=hide`` 3740 Suppress unstable command results and events 3741 3742 Limitation: covers only syntactic aspects of QMP. 3743ERST 3744 3745DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3746 "-fw_cfg [name=]<name>,file=<file>\n" 3747 " add named fw_cfg entry with contents from file\n" 3748 "-fw_cfg [name=]<name>,string=<str>\n" 3749 " add named fw_cfg entry with contents from string\n", 3750 QEMU_ARCH_ALL) 3751SRST 3752``-fw_cfg [name=]name,file=file`` 3753 Add named fw\_cfg entry with contents from file file. 3754 3755``-fw_cfg [name=]name,string=str`` 3756 Add named fw\_cfg entry with contents from string str. 3757 3758 The terminating NUL character of the contents of str will not be 3759 included as part of the fw\_cfg item data. To insert contents with 3760 embedded NUL characters, you have to use the file parameter. 3761 3762 The fw\_cfg entries are passed by QEMU through to the guest. 3763 3764 Example: 3765 3766 :: 3767 3768 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3769 3770 creates an fw\_cfg entry named opt/com.mycompany/blob with contents 3771 from ./my\_blob.bin. 3772ERST 3773 3774DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3775 "-serial dev redirect the serial port to char device 'dev'\n", 3776 QEMU_ARCH_ALL) 3777SRST 3778``-serial dev`` 3779 Redirect the virtual serial port to host character device dev. The 3780 default device is ``vc`` in graphical mode and ``stdio`` in non 3781 graphical mode. 3782 3783 This option can be used several times to simulate up to 4 serial 3784 ports. 3785 3786 Use ``-serial none`` to disable all serial ports. 3787 3788 Available character devices are: 3789 3790 ``vc[:WxH]`` 3791 Virtual console. Optionally, a width and height can be given in 3792 pixel with 3793 3794 :: 3795 3796 vc:800x600 3797 3798 It is also possible to specify width or height in characters: 3799 3800 :: 3801 3802 vc:80Cx24C 3803 3804 ``pty`` 3805 [Linux only] Pseudo TTY (a new PTY is automatically allocated) 3806 3807 ``none`` 3808 No device is allocated. 3809 3810 ``null`` 3811 void device 3812 3813 ``chardev:id`` 3814 Use a named character device defined with the ``-chardev`` 3815 option. 3816 3817 ``/dev/XXX`` 3818 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial 3819 port parameters are set according to the emulated ones. 3820 3821 ``/dev/parportN`` 3822 [Linux only, parallel port only] Use host parallel port N. 3823 Currently SPP and EPP parallel port features can be used. 3824 3825 ``file:filename`` 3826 Write output to filename. No character can be read. 3827 3828 ``stdio`` 3829 [Unix only] standard input/output 3830 3831 ``pipe:filename`` 3832 name pipe filename 3833 3834 ``COMn`` 3835 [Windows only] Use host serial port n 3836 3837 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]`` 3838 This implements UDP Net Console. When remote\_host or src\_ip 3839 are not specified they default to ``0.0.0.0``. When not using a 3840 specified src\_port a random port is automatically chosen. 3841 3842 If you just want a simple readonly console you can use 3843 ``netcat`` or ``nc``, by starting QEMU with: 3844 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time 3845 QEMU writes something to that port it will appear in the 3846 netconsole session. 3847 3848 If you plan to send characters back via netconsole or you want 3849 to stop and start QEMU a lot of times, you should have QEMU use 3850 the same source port each time by using something like ``-serial 3851 udp::4555@:4556`` to QEMU. Another approach is to use a patched 3852 version of netcat which can listen to a TCP port and send and 3853 receive characters via udp. If you have a patched version of 3854 netcat which activates telnet remote echo and single char 3855 transfer, then you can use the following options to set up a 3856 netcat redirector to allow telnet on port 5555 to access the 3857 QEMU port. 3858 3859 ``QEMU Options:`` 3860 -serial udp::4555@:4556 3861 3862 ``netcat options:`` 3863 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3864 3865 ``telnet options:`` 3866 localhost 5555 3867 3868 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]`` 3869 The TCP Net Console has two modes of operation. It can send the 3870 serial I/O to a location or wait for a connection from a 3871 location. By default the TCP Net Console is sent to host at the 3872 port. If you use the ``server=on`` option QEMU will wait for a client 3873 socket application to connect to the port before continuing, 3874 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off`` 3875 option disables the Nagle buffering algorithm. The ``reconnect=on`` 3876 option only applies if ``server=no`` is set, if the connection goes 3877 down it will attempt to reconnect at the given interval. If host 3878 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a 3879 time is accepted. You can use ``telnet=on`` to connect to the 3880 corresponding character device. 3881 3882 ``Example to send tcp console to 192.168.0.2 port 4444`` 3883 -serial tcp:192.168.0.2:4444 3884 3885 ``Example to listen and wait on port 4444 for connection`` 3886 -serial tcp::4444,server=on 3887 3888 ``Example to not wait and listen on ip 192.168.0.100 port 4444`` 3889 -serial tcp:192.168.0.100:4444,server=on,wait=off 3890 3891 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]`` 3892 The telnet protocol is used instead of raw tcp sockets. The 3893 options work the same as if you had specified ``-serial tcp``. 3894 The difference is that the port acts like a telnet server or 3895 client using telnet option negotiation. This will also allow you 3896 to send the MAGIC\_SYSRQ sequence if you use a telnet that 3897 supports sending the break sequence. Typically in unix telnet 3898 you do it with Control-] and then type "send break" followed by 3899 pressing the enter key. 3900 3901 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]`` 3902 The WebSocket protocol is used instead of raw tcp socket. The 3903 port acts as a WebSocket server. Client mode is not supported. 3904 3905 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]`` 3906 A unix domain socket is used instead of a tcp socket. The option 3907 works the same as if you had specified ``-serial tcp`` except 3908 the unix domain socket path is used for connections. 3909 3910 ``mon:dev_string`` 3911 This is a special option to allow the monitor to be multiplexed 3912 onto another serial port. The monitor is accessed with key 3913 sequence of Control-a and then pressing c. dev\_string should be 3914 any one of the serial devices specified above. An example to 3915 multiplex the monitor onto a telnet server listening on port 3916 4444 would be: 3917 3918 ``-serial mon:telnet::4444,server=on,wait=off`` 3919 3920 When the monitor is multiplexed to stdio in this way, Ctrl+C 3921 will not terminate QEMU any more but will be passed to the guest 3922 instead. 3923 3924 ``braille`` 3925 Braille device. This will use BrlAPI to display the braille 3926 output on a real or fake device. 3927 3928 ``msmouse`` 3929 Three button serial mouse. Configure the guest to use Microsoft 3930 protocol. 3931ERST 3932 3933DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3934 "-parallel dev redirect the parallel port to char device 'dev'\n", 3935 QEMU_ARCH_ALL) 3936SRST 3937``-parallel dev`` 3938 Redirect the virtual parallel port to host device dev (same devices 3939 as the serial port). On Linux hosts, ``/dev/parportN`` can be used 3940 to use hardware devices connected on the corresponding host parallel 3941 port. 3942 3943 This option can be used several times to simulate up to 3 parallel 3944 ports. 3945 3946 Use ``-parallel none`` to disable all parallel ports. 3947ERST 3948 3949DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3950 "-monitor dev redirect the monitor to char device 'dev'\n", 3951 QEMU_ARCH_ALL) 3952SRST 3953``-monitor dev`` 3954 Redirect the monitor to host device dev (same devices as the serial 3955 port). The default device is ``vc`` in graphical mode and ``stdio`` 3956 in non graphical mode. Use ``-monitor none`` to disable the default 3957 monitor. 3958ERST 3959DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3960 "-qmp dev like -monitor but opens in 'control' mode\n", 3961 QEMU_ARCH_ALL) 3962SRST 3963``-qmp dev`` 3964 Like -monitor but opens in 'control' mode. 3965ERST 3966DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3967 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3968 QEMU_ARCH_ALL) 3969SRST 3970``-qmp-pretty dev`` 3971 Like -qmp but uses pretty JSON formatting. 3972ERST 3973 3974DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3975 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3976SRST 3977``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]`` 3978 Setup monitor on chardev name. ``mode=control`` configures 3979 a QMP monitor (a JSON RPC-style protocol) and it is not the 3980 same as HMP, the human monitor that has a "(qemu)" prompt. 3981 ``pretty`` is only valid when ``mode=control``, 3982 turning on JSON pretty printing to ease 3983 human reading and debugging. 3984ERST 3985 3986DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3987 "-debugcon dev redirect the debug console to char device 'dev'\n", 3988 QEMU_ARCH_ALL) 3989SRST 3990``-debugcon dev`` 3991 Redirect the debug console to host device dev (same devices as the 3992 serial port). The debug console is an I/O port which is typically 3993 port 0xe9; writing to that I/O port sends output to this device. The 3994 default device is ``vc`` in graphical mode and ``stdio`` in non 3995 graphical mode. 3996ERST 3997 3998DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3999 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 4000SRST 4001``-pidfile file`` 4002 Store the QEMU process PID in file. It is useful if you launch QEMU 4003 from a script. 4004ERST 4005 4006DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 4007 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 4008SRST 4009``-singlestep`` 4010 Run the emulation in single step mode. 4011ERST 4012 4013DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 4014 "--preconfig pause QEMU before machine is initialized (experimental)\n", 4015 QEMU_ARCH_ALL) 4016SRST 4017``--preconfig`` 4018 Pause QEMU for interactive configuration before the machine is 4019 created, which allows querying and configuring properties that will 4020 affect machine initialization. Use QMP command 'x-exit-preconfig' to 4021 exit the preconfig state and move to the next state (i.e. run guest 4022 if -S isn't used or pause the second time if -S is used). This 4023 option is experimental. 4024ERST 4025 4026DEF("S", 0, QEMU_OPTION_S, \ 4027 "-S freeze CPU at startup (use 'c' to start execution)\n", 4028 QEMU_ARCH_ALL) 4029SRST 4030``-S`` 4031 Do not start CPU at startup (you must type 'c' in the monitor). 4032ERST 4033 4034DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 4035 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 4036 " run qemu with overcommit hints\n" 4037 " mem-lock=on|off controls memory lock support (default: off)\n" 4038 " cpu-pm=on|off controls cpu power management (default: off)\n", 4039 QEMU_ARCH_ALL) 4040SRST 4041``-overcommit mem-lock=on|off`` 4042 \ 4043``-overcommit cpu-pm=on|off`` 4044 Run qemu with hints about host resource overcommit. The default is 4045 to assume that host overcommits all resources. 4046 4047 Locking qemu and guest memory can be enabled via ``mem-lock=on`` 4048 (disabled by default). This works when host memory is not 4049 overcommitted and reduces the worst-case latency for guest. 4050 4051 Guest ability to manage power state of host cpus (increasing latency 4052 for other processes on the same host cpu, but decreasing latency for 4053 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This 4054 works best when host CPU is not overcommitted. When used, host 4055 estimates of CPU cycle and power utilization will be incorrect, not 4056 taking into account guest idle time. 4057ERST 4058 4059DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 4060 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n" 4061 " the guest without waiting for gdb to connect; use -S too\n" 4062 " if you want it to not start execution.)\n", 4063 QEMU_ARCH_ALL) 4064SRST 4065``-gdb dev`` 4066 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter 4067 in the System Emulation Users Guide). Note that this option does not pause QEMU 4068 execution -- if you want QEMU to not start the guest until you 4069 connect with gdb and issue a ``continue`` command, you will need to 4070 also pass the ``-S`` option to QEMU. 4071 4072 The most usual configuration is to listen on a local TCP socket:: 4073 4074 -gdb tcp::3117 4075 4076 but you can specify other backends; UDP, pseudo TTY, or even stdio 4077 are all reasonable use cases. For example, a stdio connection 4078 allows you to start QEMU from within gdb and establish the 4079 connection via a pipe: 4080 4081 .. parsed-literal:: 4082 4083 (gdb) target remote | exec |qemu_system| -gdb stdio ... 4084ERST 4085 4086DEF("s", 0, QEMU_OPTION_s, \ 4087 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 4088 QEMU_ARCH_ALL) 4089SRST 4090``-s`` 4091 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 4092 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide). 4093ERST 4094 4095DEF("d", HAS_ARG, QEMU_OPTION_d, \ 4096 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 4097 QEMU_ARCH_ALL) 4098SRST 4099``-d item1[,...]`` 4100 Enable logging of specified items. Use '-d help' for a list of log 4101 items. 4102ERST 4103 4104DEF("D", HAS_ARG, QEMU_OPTION_D, \ 4105 "-D logfile output log to logfile (default stderr)\n", 4106 QEMU_ARCH_ALL) 4107SRST 4108``-D logfile`` 4109 Output log in logfile instead of to stderr 4110ERST 4111 4112DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 4113 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 4114 QEMU_ARCH_ALL) 4115SRST 4116``-dfilter range1[,...]`` 4117 Filter debug output to that relevant to a range of target addresses. 4118 The filter spec can be either start+size, start-size or start..end 4119 where start end and size are the addresses and sizes required. For 4120 example: 4121 4122 :: 4123 4124 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 4125 4126 Will dump output for any code in the 0x1000 sized block starting at 4127 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and 4128 another 0x1000 sized block starting at 0xffffffc00005f000. 4129ERST 4130 4131DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 4132 "-seed number seed the pseudo-random number generator\n", 4133 QEMU_ARCH_ALL) 4134SRST 4135``-seed number`` 4136 Force the guest to use a deterministic pseudo-random number 4137 generator, seeded with number. This does not affect crypto routines 4138 within the host. 4139ERST 4140 4141DEF("L", HAS_ARG, QEMU_OPTION_L, \ 4142 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 4143 QEMU_ARCH_ALL) 4144SRST 4145``-L path`` 4146 Set the directory for the BIOS, VGA BIOS and keymaps. 4147 4148 To list all the data directories, use ``-L help``. 4149ERST 4150 4151DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 4152 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 4153SRST 4154``-bios file`` 4155 Set the filename for the BIOS. 4156ERST 4157 4158DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 4159 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 4160SRST 4161``-enable-kvm`` 4162 Enable KVM full virtualization support. This option is only 4163 available if KVM support is enabled when compiling. 4164ERST 4165 4166DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 4167 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 4168DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 4169 "-xen-attach attach to existing xen domain\n" 4170 " libxl will use this when starting QEMU\n", 4171 QEMU_ARCH_ALL) 4172DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 4173 "-xen-domid-restrict restrict set of available xen operations\n" 4174 " to specified domain id. (Does not affect\n" 4175 " xenpv machine type).\n", 4176 QEMU_ARCH_ALL) 4177SRST 4178``-xen-domid id`` 4179 Specify xen guest domain id (XEN only). 4180 4181``-xen-attach`` 4182 Attach to existing xen domain. libxl will use this when starting 4183 QEMU (XEN only). Restrict set of available xen operations to 4184 specified domain id (XEN only). 4185ERST 4186 4187DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 4188 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 4189SRST 4190``-no-reboot`` 4191 Exit instead of rebooting. 4192ERST 4193 4194DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 4195 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 4196SRST 4197``-no-shutdown`` 4198 Don't exit QEMU on guest shutdown, but instead only stop the 4199 emulation. This allows for instance switching to monitor to commit 4200 changes to the disk image. 4201ERST 4202 4203DEF("action", HAS_ARG, QEMU_OPTION_action, 4204 "-action reboot=reset|shutdown\n" 4205 " action when guest reboots [default=reset]\n" 4206 "-action shutdown=poweroff|pause\n" 4207 " action when guest shuts down [default=poweroff]\n" 4208 "-action panic=pause|shutdown|none\n" 4209 " action when guest panics [default=shutdown]\n" 4210 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" 4211 " action when watchdog fires [default=reset]\n", 4212 QEMU_ARCH_ALL) 4213SRST 4214``-action event=action`` 4215 The action parameter serves to modify QEMU's default behavior when 4216 certain guest events occur. It provides a generic method for specifying the 4217 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown`` 4218 parameters. 4219 4220 Examples: 4221 4222 ``-action panic=none`` 4223 ``-action reboot=shutdown,shutdown=pause`` 4224 ``-watchdog i6300esb -action watchdog=pause`` 4225 4226ERST 4227 4228DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 4229 "-loadvm [tag|id]\n" \ 4230 " start right away with a saved state (loadvm in monitor)\n", 4231 QEMU_ARCH_ALL) 4232SRST 4233``-loadvm file`` 4234 Start right away with a saved state (``loadvm`` in monitor) 4235ERST 4236 4237#ifndef _WIN32 4238DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 4239 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 4240#endif 4241SRST 4242``-daemonize`` 4243 Daemonize the QEMU process after initialization. QEMU will not 4244 detach from standard IO until it is ready to receive connections on 4245 any of its devices. This option is a useful way for external 4246 programs to launch QEMU without having to cope with initialization 4247 race conditions. 4248ERST 4249 4250DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 4251 "-option-rom rom load a file, rom, into the option ROM space\n", 4252 QEMU_ARCH_ALL) 4253SRST 4254``-option-rom file`` 4255 Load the contents of file as an option ROM. This option is useful to 4256 load things like EtherBoot. 4257ERST 4258 4259DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 4260 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 4261 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 4262 QEMU_ARCH_ALL) 4263 4264SRST 4265``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]`` 4266 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at 4267 the current UTC or local time, respectively. ``localtime`` is 4268 required for correct date in MS-DOS or Windows. To start at a 4269 specific point in time, provide datetime in the format 4270 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC. 4271 4272 By default the RTC is driven by the host system time. This allows 4273 using of the RTC as accurate reference clock inside the guest, 4274 specifically if the host time is smoothly following an accurate 4275 external reference clock, e.g. via NTP. If you want to isolate the 4276 guest time from the host, you can set ``clock`` to ``rt`` instead, 4277 which provides a host monotonic clock if host support it. To even 4278 prevent the RTC from progressing during suspension, you can set 4279 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is 4280 recommended especially in icount mode in order to preserve 4281 determinism; however, note that in icount mode the speed of the 4282 virtual clock is variable and can in general differ from the host 4283 clock. 4284 4285 Enable ``driftfix`` (i386 targets only) if you experience time drift 4286 problems, specifically with Windows' ACPI HAL. This option will try 4287 to figure out how many timer interrupts were not processed by the 4288 Windows guest and will re-inject them. 4289ERST 4290 4291DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 4292 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \ 4293 " enable virtual instruction counter with 2^N clock ticks per\n" \ 4294 " instruction, enable aligning the host and virtual clocks\n" \ 4295 " or disable real time cpu sleeping, and optionally enable\n" \ 4296 " record-and-replay mode\n", QEMU_ARCH_ALL) 4297SRST 4298``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]`` 4299 Enable virtual instruction counter. The virtual cpu will execute one 4300 instruction every 2^N ns of virtual time. If ``auto`` is specified 4301 then the virtual cpu speed will be automatically adjusted to keep 4302 virtual time within a few seconds of real time. 4303 4304 Note that while this option can give deterministic behavior, it does 4305 not provide cycle accurate emulation. Modern CPUs contain 4306 superscalar out of order cores with complex cache hierarchies. The 4307 number of instructions executed often has little or no correlation 4308 with actual performance. 4309 4310 When the virtual cpu is sleeping, the virtual time will advance at 4311 default speed unless ``sleep=on`` is specified. With 4312 ``sleep=on``, the virtual time will jump to the next timer 4313 deadline instantly whenever the virtual cpu goes to sleep mode and 4314 will not advance if no timer is enabled. This behavior gives 4315 deterministic execution times from the guest point of view. 4316 The default if icount is enabled is ``sleep=off``. 4317 ``sleep=on`` cannot be used together with either ``shift=auto`` 4318 or ``align=on``. 4319 4320 ``align=on`` will activate the delay algorithm which will try to 4321 synchronise the host clock and the virtual clock. The goal is to 4322 have a guest running at the real frequency imposed by the shift 4323 option. Whenever the guest clock is behind the host clock and if 4324 ``align=on`` is specified then we print a message to the user to 4325 inform about the delay. Currently this option does not work when 4326 ``shift`` is ``auto``. Note: The sync algorithm will work for those 4327 shift values for which the guest clock runs ahead of the host clock. 4328 Typically this happens when the shift value is high (how high 4329 depends on the host machine). The default if icount is enabled 4330 is ``align=off``. 4331 4332 When the ``rr`` option is specified deterministic record/replay is 4333 enabled. The ``rrfile=`` option must also be provided to 4334 specify the path to the replay log. In record mode data is written 4335 to this file, and in replay mode it is read back. 4336 If the ``rrsnapshot`` option is given then it specifies a VM snapshot 4337 name. In record mode, a new VM snapshot with the given name is created 4338 at the start of execution recording. In replay mode this option 4339 specifies the snapshot name used to load the initial VM state. 4340ERST 4341 4342DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 4343 "-watchdog model\n" \ 4344 " enable virtual hardware watchdog [default=none]\n", 4345 QEMU_ARCH_ALL) 4346SRST 4347``-watchdog model`` 4348 Create a virtual hardware watchdog device. Once enabled (by a guest 4349 action), the watchdog must be periodically polled by an agent inside 4350 the guest or else the guest will be restarted. Choose a model for 4351 which your guest has drivers. 4352 4353 The model is the model of hardware watchdog to emulate. Use 4354 ``-watchdog help`` to list available hardware models. Only one 4355 watchdog can be enabled for a guest. 4356 4357 The following models may be available: 4358 4359 ``ib700`` 4360 iBASE 700 is a very simple ISA watchdog with a single timer. 4361 4362 ``i6300esb`` 4363 Intel 6300ESB I/O controller hub is a much more featureful 4364 PCI-based dual-timer watchdog. 4365 4366 ``diag288`` 4367 A virtual watchdog for s390x backed by the diagnose 288 4368 hypercall (currently KVM only). 4369ERST 4370 4371DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 4372 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 4373 " action when watchdog fires [default=reset]\n", 4374 QEMU_ARCH_ALL) 4375SRST 4376``-watchdog-action action`` 4377 The action controls what QEMU will do when the watchdog timer 4378 expires. The default is ``reset`` (forcefully reset the guest). 4379 Other possible actions are: ``shutdown`` (attempt to gracefully 4380 shutdown the guest), ``poweroff`` (forcefully poweroff the guest), 4381 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the 4382 guest), ``debug`` (print a debug message and continue), or ``none`` 4383 (do nothing). 4384 4385 Note that the ``shutdown`` action requires that the guest responds 4386 to ACPI signals, which it may not be able to do in the sort of 4387 situations where the watchdog would have expired, and thus 4388 ``-watchdog-action shutdown`` is not recommended for production use. 4389 4390 Examples: 4391 4392 ``-watchdog i6300esb -watchdog-action pause``; \ ``-watchdog ib700`` 4393 4394ERST 4395 4396DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 4397 "-echr chr set terminal escape character instead of ctrl-a\n", 4398 QEMU_ARCH_ALL) 4399SRST 4400``-echr numeric_ascii_value`` 4401 Change the escape character used for switching to the monitor when 4402 using monitor and serial sharing. The default is ``0x01`` when using 4403 the ``-nographic`` option. ``0x01`` is equal to pressing 4404 ``Control-a``. You can select a different character from the ascii 4405 control keys where 1 through 26 map to Control-a through Control-z. 4406 For instance you could use the either of the following to change the 4407 escape character to Control-t. 4408 4409 ``-echr 0x14``; \ ``-echr 20`` 4410 4411ERST 4412 4413DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4414 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \ 4415 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \ 4416 "-incoming unix:socketpath\n" \ 4417 " prepare for incoming migration, listen on\n" \ 4418 " specified protocol and socket address\n" \ 4419 "-incoming fd:fd\n" \ 4420 "-incoming exec:cmdline\n" \ 4421 " accept incoming migration on given file descriptor\n" \ 4422 " or from given external command\n" \ 4423 "-incoming defer\n" \ 4424 " wait for the URI to be specified via migrate_incoming\n", 4425 QEMU_ARCH_ALL) 4426SRST 4427``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]`` 4428 \ 4429``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]`` 4430 Prepare for incoming migration, listen on a given tcp port. 4431 4432``-incoming unix:socketpath`` 4433 Prepare for incoming migration, listen on a given unix socket. 4434 4435``-incoming fd:fd`` 4436 Accept incoming migration from a given filedescriptor. 4437 4438``-incoming exec:cmdline`` 4439 Accept incoming migration as an output from specified external 4440 command. 4441 4442``-incoming defer`` 4443 Wait for the URI to be specified via migrate\_incoming. The monitor 4444 can be used to change settings (such as migration parameters) prior 4445 to issuing the migrate\_incoming to allow the migration to begin. 4446ERST 4447 4448DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4449 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4450SRST 4451``-only-migratable`` 4452 Only allow migratable devices. Devices will not be allowed to enter 4453 an unmigratable state. 4454ERST 4455 4456DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4457 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4458SRST 4459``-nodefaults`` 4460 Don't create default devices. Normally, QEMU sets the default 4461 devices like serial port, parallel port, virtual console, monitor 4462 device, VGA adapter, floppy and CD-ROM drive and others. The 4463 ``-nodefaults`` option will disable all those default devices. 4464ERST 4465 4466#ifndef _WIN32 4467DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4468 "-chroot dir chroot to dir just before starting the VM\n", 4469 QEMU_ARCH_ALL) 4470#endif 4471SRST 4472``-chroot dir`` 4473 Immediately before starting guest execution, chroot to the specified 4474 directory. Especially useful in combination with -runas. 4475ERST 4476 4477#ifndef _WIN32 4478DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4479 "-runas user change to user id user just before starting the VM\n" \ 4480 " user can be numeric uid:gid instead\n", 4481 QEMU_ARCH_ALL) 4482#endif 4483SRST 4484``-runas user`` 4485 Immediately before starting guest execution, drop root privileges, 4486 switching to the specified user. 4487ERST 4488 4489DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4490 "-prom-env variable=value\n" 4491 " set OpenBIOS nvram variables\n", 4492 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4493SRST 4494``-prom-env variable=value`` 4495 Set OpenBIOS nvram variable to given value (PPC, SPARC only). 4496 4497 :: 4498 4499 qemu-system-sparc -prom-env 'auto-boot?=false' \ 4500 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' 4501 4502 :: 4503 4504 qemu-system-ppc -prom-env 'auto-boot?=false' \ 4505 -prom-env 'boot-device=hd:2,\yaboot' \ 4506 -prom-env 'boot-args=conf=hd:2,\yaboot.conf' 4507ERST 4508DEF("semihosting", 0, QEMU_OPTION_semihosting, 4509 "-semihosting semihosting mode\n", 4510 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4511 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4512SRST 4513``-semihosting`` 4514 Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V only). 4515 4516 Note that this allows guest direct access to the host filesystem, so 4517 should only be used with a trusted guest OS. 4518 4519 See the -semihosting-config option documentation for further 4520 information about the facilities this enables. 4521ERST 4522DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4523 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4524 " semihosting configuration\n", 4525QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4526QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4527SRST 4528``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]`` 4529 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V 4530 only). 4531 4532 Note that this allows guest direct access to the host filesystem, so 4533 should only be used with a trusted guest OS. 4534 4535 On Arm this implements the standard semihosting API, version 2.0. 4536 4537 On M68K this implements the "ColdFire GDB" interface used by 4538 libgloss. 4539 4540 Xtensa semihosting provides basic file IO calls, such as 4541 open/read/write/seek/select. Tensilica baremetal libc for ISS and 4542 linux platform "sim" use this interface. 4543 4544 On RISC-V this implements the standard semihosting API, version 0.2. 4545 4546 ``target=native|gdb|auto`` 4547 Defines where the semihosting calls will be addressed, to QEMU 4548 (``native``) or to GDB (``gdb``). The default is ``auto``, which 4549 means ``gdb`` during debug sessions and ``native`` otherwise. 4550 4551 ``chardev=str1`` 4552 Send the output to a chardev backend output for native or auto 4553 output when not in gdb 4554 4555 ``arg=str1,arg=str2,...`` 4556 Allows the user to pass input arguments, and can be used 4557 multiple times to build up a list. The old-style 4558 ``-kernel``/``-append`` method of passing a command line is 4559 still supported for backward compatibility. If both the 4560 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are 4561 specified, the former is passed to semihosting as it always 4562 takes precedence. 4563ERST 4564DEF("old-param", 0, QEMU_OPTION_old_param, 4565 "-old-param old param mode\n", QEMU_ARCH_ARM) 4566SRST 4567``-old-param`` 4568 Old param mode (ARM only). 4569ERST 4570 4571DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4572 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4573 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4574 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4575 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4576 " by the kernel, but typically no longer used by modern\n" \ 4577 " C library implementations.\n" \ 4578 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \ 4579 " to elevate privileges using set*uid|gid system calls.\n" \ 4580 " The value 'children' will deny set*uid|gid system calls for\n" \ 4581 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4582 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4583 " blocking *fork and execve\n" \ 4584 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4585 QEMU_ARCH_ALL) 4586SRST 4587``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]`` 4588 Enable Seccomp mode 2 system call filter. 'on' will enable syscall 4589 filtering and 'off' will disable it. The default is 'off'. 4590 4591 ``obsolete=string`` 4592 Enable Obsolete system calls 4593 4594 ``elevateprivileges=string`` 4595 Disable set\*uid\|gid system calls 4596 4597 ``spawn=string`` 4598 Disable \*fork and execve 4599 4600 ``resourcecontrol=string`` 4601 Disable process affinity and schedular priority 4602ERST 4603 4604DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4605 "-readconfig <file>\n", QEMU_ARCH_ALL) 4606SRST 4607``-readconfig file`` 4608 Read device configuration from file. This approach is useful when 4609 you want to spawn QEMU process with many command line options but 4610 you don't want to exceed the command line character limit. 4611ERST 4612DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4613 "-writeconfig <file>\n" 4614 " read/write config file (deprecated)\n", QEMU_ARCH_ALL) 4615SRST 4616ERST 4617 4618DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4619 "-no-user-config\n" 4620 " do not load default user-provided config files at startup\n", 4621 QEMU_ARCH_ALL) 4622SRST 4623``-no-user-config`` 4624 The ``-no-user-config`` option makes QEMU not load any of the 4625 user-provided config files on sysconfdir. 4626ERST 4627 4628DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4629 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4630 " specify tracing options\n", 4631 QEMU_ARCH_ALL) 4632SRST 4633``-trace [[enable=]pattern][,events=file][,file=file]`` 4634 .. include:: ../qemu-option-trace.rst.inc 4635 4636ERST 4637DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4638 "-plugin [file=]<file>[,<argname>=<argvalue>]\n" 4639 " load a plugin\n", 4640 QEMU_ARCH_ALL) 4641SRST 4642``-plugin file=file[,argname=argvalue]`` 4643 Load a plugin. 4644 4645 ``file=file`` 4646 Load the given plugin from a shared library file. 4647 4648 ``argname=argvalue`` 4649 Argument passed to the plugin. (Can be given multiple times.) 4650ERST 4651 4652HXCOMM Internal use 4653DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4654DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4655 4656#ifdef __linux__ 4657DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4658 "-enable-fips enable FIPS 140-2 compliance\n", 4659 QEMU_ARCH_ALL) 4660#endif 4661SRST 4662``-enable-fips`` 4663 Enable FIPS 140-2 compliance mode. 4664ERST 4665 4666DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4667 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n" 4668 " control error message format\n" 4669 " timestamp=on enables timestamps (default: off)\n" 4670 " guest-name=on enables guest name prefix but only if\n" 4671 " -name guest option is set (default: off)\n", 4672 QEMU_ARCH_ALL) 4673SRST 4674``-msg [timestamp[=on|off]][,guest-name[=on|off]]`` 4675 Control error message format. 4676 4677 ``timestamp=on|off`` 4678 Prefix messages with a timestamp. Default is off. 4679 4680 ``guest-name=on|off`` 4681 Prefix messages with guest name but only if -name guest option is set 4682 otherwise the option is ignored. Default is off. 4683ERST 4684 4685DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4686 "-dump-vmstate <file>\n" 4687 " Output vmstate information in JSON format to file.\n" 4688 " Use the scripts/vmstate-static-checker.py file to\n" 4689 " check for possible regressions in migration code\n" 4690 " by comparing two such vmstate dumps.\n", 4691 QEMU_ARCH_ALL) 4692SRST 4693``-dump-vmstate file`` 4694 Dump json-encoded vmstate information for current machine type to 4695 file in file 4696ERST 4697 4698DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4699 "-enable-sync-profile\n" 4700 " enable synchronization profiling\n", 4701 QEMU_ARCH_ALL) 4702SRST 4703``-enable-sync-profile`` 4704 Enable synchronization profiling. 4705ERST 4706 4707DEFHEADING() 4708 4709DEFHEADING(Generic object creation:) 4710 4711DEF("object", HAS_ARG, QEMU_OPTION_object, 4712 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4713 " create a new object of type TYPENAME setting properties\n" 4714 " in the order they are specified. Note that the 'id'\n" 4715 " property must be set. These objects are placed in the\n" 4716 " '/objects' path.\n", 4717 QEMU_ARCH_ALL) 4718SRST 4719``-object typename[,prop1=value1,...]`` 4720 Create a new object of type typename setting properties in the order 4721 they are specified. Note that the 'id' property must be set. These 4722 objects are placed in the '/objects' path. 4723 4724 ``-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,readonly=on|off`` 4725 Creates a memory file backend object, which can be used to back 4726 the guest RAM with huge pages. 4727 4728 The ``id`` parameter is a unique ID that will be used to 4729 reference this memory region in other parameters, e.g. ``-numa``, 4730 ``-device nvdimm``, etc. 4731 4732 The ``size`` option provides the size of the memory region, and 4733 accepts common suffixes, e.g. ``500M``. 4734 4735 The ``mem-path`` provides the path to either a shared memory or 4736 huge page filesystem mount. 4737 4738 The ``share`` boolean option determines whether the memory 4739 region is marked as private to QEMU, or shared. The latter 4740 allows a co-operating external process to access the QEMU memory 4741 region. 4742 4743 The ``share`` is also required for pvrdma devices due to 4744 limitations in the RDMA API provided by Linux. 4745 4746 Setting share=on might affect the ability to configure NUMA 4747 bindings for the memory backend under some circumstances, see 4748 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel 4749 source tree for additional details. 4750 4751 Setting the ``discard-data`` boolean option to on indicates that 4752 file contents can be destroyed when QEMU exits, to avoid 4753 unnecessarily flushing data to the backing file. Note that 4754 ``discard-data`` is only an optimization, and QEMU might not 4755 discard file contents if it aborts unexpectedly or is terminated 4756 using SIGKILL. 4757 4758 The ``merge`` boolean option enables memory merge, also known as 4759 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider 4760 the pages for memory deduplication. 4761 4762 Setting the ``dump`` boolean option to off excludes the memory 4763 from core dumps. This feature is also known as MADV\_DONTDUMP. 4764 4765 The ``prealloc`` boolean option enables memory preallocation. 4766 4767 The ``host-nodes`` option binds the memory range to a list of 4768 NUMA host nodes. 4769 4770 The ``policy`` option sets the NUMA policy to one of the 4771 following values: 4772 4773 ``default`` 4774 default host policy 4775 4776 ``preferred`` 4777 prefer the given host node list for allocation 4778 4779 ``bind`` 4780 restrict memory allocation to the given host node list 4781 4782 ``interleave`` 4783 interleave memory allocations across the given host node 4784 list 4785 4786 The ``align`` option specifies the base address alignment when 4787 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg 4788 ``2M``. Some backend store specified by ``mem-path`` requires an 4789 alignment different than the default one used by QEMU, eg the 4790 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4791 such cases, users can specify the required alignment via this 4792 option. 4793 4794 The ``pmem`` option specifies whether the backing file specified 4795 by ``mem-path`` is in host persistent memory that can be 4796 accessed using the SNIA NVM programming model (e.g. Intel 4797 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary 4798 operations to guarantee the persistence of its own writes to 4799 ``mem-path`` (e.g. in vNVDIMM label emulation and live 4800 migration). Also, we will map the backend-file with MAP\_SYNC 4801 flag, which ensures the file metadata is in sync for 4802 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC 4803 requires support from both the host kernel (since Linux kernel 4804 4.15) and the filesystem of ``mem-path`` mounted with DAX 4805 option. 4806 4807 The ``readonly`` option specifies whether the backing file is opened 4808 read-only or read-write (default). 4809 4810 ``-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`` 4811 Creates a memory backend object, which can be used to back the 4812 guest RAM. Memory backend objects offer more control than the 4813 ``-m`` option that is traditionally used to define guest RAM. 4814 Please refer to ``memory-backend-file`` for a description of the 4815 options. 4816 4817 ``-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`` 4818 Creates an anonymous memory file backend object, which allows 4819 QEMU to share the memory with an external process (e.g. when 4820 using vhost-user). The memory is allocated with memfd and 4821 optional sealing. (Linux only) 4822 4823 The ``seal`` option creates a sealed-file, that will block 4824 further resizing the memory ('on' by default). 4825 4826 The ``hugetlb`` option specify the file to be created resides in 4827 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction 4828 with the ``hugetlb`` option, the ``hugetlbsize`` option specify 4829 the hugetlb page size on systems that support multiple hugetlb 4830 page sizes (it must be a power of 2 value supported by the 4831 system). 4832 4833 In some versions of Linux, the ``hugetlb`` option is 4834 incompatible with the ``seal`` option (requires at least Linux 4835 4.16). 4836 4837 Please refer to ``memory-backend-file`` for a description of the 4838 other options. 4839 4840 The ``share`` boolean option is on by default with memfd. 4841 4842 ``-object rng-builtin,id=id`` 4843 Creates a random number generator backend which obtains entropy 4844 from QEMU builtin functions. The ``id`` parameter is a unique ID 4845 that will be used to reference this entropy backend from the 4846 ``virtio-rng`` device. By default, the ``virtio-rng`` device 4847 uses this RNG backend. 4848 4849 ``-object rng-random,id=id,filename=/dev/random`` 4850 Creates a random number generator backend which obtains entropy 4851 from a device on the host. The ``id`` parameter is a unique ID 4852 that will be used to reference this entropy backend from the 4853 ``virtio-rng`` device. The ``filename`` parameter specifies 4854 which file to obtain entropy from and if omitted defaults to 4855 ``/dev/urandom``. 4856 4857 ``-object rng-egd,id=id,chardev=chardevid`` 4858 Creates a random number generator backend which obtains entropy 4859 from an external daemon running on the host. The ``id`` 4860 parameter is a unique ID that will be used to reference this 4861 entropy backend from the ``virtio-rng`` device. The ``chardev`` 4862 parameter is the unique ID of a character device backend that 4863 provides the connection to the RNG daemon. 4864 4865 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off`` 4866 Creates a TLS anonymous credentials object, which can be used to 4867 provide TLS support on network backends. The ``id`` parameter is 4868 a unique ID which network backends will use to access the 4869 credentials. The ``endpoint`` is either ``server`` or ``client`` 4870 depending on whether the QEMU network backend that uses the 4871 credentials will be acting as a client or as a server. If 4872 ``verify-peer`` is enabled (the default) then once the handshake 4873 is completed, the peer credentials will be verified, though this 4874 is a no-op for anonymous credentials. 4875 4876 The dir parameter tells QEMU where to find the credential files. 4877 For server endpoints, this directory may contain a file 4878 dh-params.pem providing diffie-hellman parameters to use for the 4879 TLS server. If the file is missing, QEMU will generate a set of 4880 DH parameters at startup. This is a computationally expensive 4881 operation that consumes random pool entropy, so it is 4882 recommended that a persistent set of parameters be generated 4883 upfront and saved. 4884 4885 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]`` 4886 Creates a TLS Pre-Shared Keys (PSK) credentials object, which 4887 can be used to provide TLS support on network backends. The 4888 ``id`` parameter is a unique ID which network backends will use 4889 to access the credentials. The ``endpoint`` is either ``server`` 4890 or ``client`` depending on whether the QEMU network backend that 4891 uses the credentials will be acting as a client or as a server. 4892 For clients only, ``username`` is the username which will be 4893 sent to the server. If omitted it defaults to "qemu". 4894 4895 The dir parameter tells QEMU where to find the keys file. It is 4896 called "dir/keys.psk" and contains "username:key" pairs. This 4897 file can most easily be created using the GnuTLS ``psktool`` 4898 program. 4899 4900 For server endpoints, dir may also contain a file dh-params.pem 4901 providing diffie-hellman parameters to use for the TLS server. 4902 If the file is missing, QEMU will generate a set of DH 4903 parameters at startup. This is a computationally expensive 4904 operation that consumes random pool entropy, so it is 4905 recommended that a persistent set of parameters be generated up 4906 front and saved. 4907 4908 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id`` 4909 Creates a TLS anonymous credentials object, which can be used to 4910 provide TLS support on network backends. The ``id`` parameter is 4911 a unique ID which network backends will use to access the 4912 credentials. The ``endpoint`` is either ``server`` or ``client`` 4913 depending on whether the QEMU network backend that uses the 4914 credentials will be acting as a client or as a server. If 4915 ``verify-peer`` is enabled (the default) then once the handshake 4916 is completed, the peer credentials will be verified. With x509 4917 certificates, this implies that the clients must be provided 4918 with valid client certificates too. 4919 4920 The dir parameter tells QEMU where to find the credential files. 4921 For server endpoints, this directory may contain a file 4922 dh-params.pem providing diffie-hellman parameters to use for the 4923 TLS server. If the file is missing, QEMU will generate a set of 4924 DH parameters at startup. This is a computationally expensive 4925 operation that consumes random pool entropy, so it is 4926 recommended that a persistent set of parameters be generated 4927 upfront and saved. 4928 4929 For x509 certificate credentials the directory will contain 4930 further files providing the x509 certificates. The certificates 4931 must be stored in PEM format, in filenames ca-cert.pem, 4932 ca-crl.pem (optional), server-cert.pem (only servers), 4933 server-key.pem (only servers), client-cert.pem (only clients), 4934 and client-key.pem (only clients). 4935 4936 For the server-key.pem and client-key.pem files which contain 4937 sensitive private keys, it is possible to use an encrypted 4938 version by providing the passwordid parameter. This provides the 4939 ID of a previously created ``secret`` object containing the 4940 password for decryption. 4941 4942 The priority parameter allows to override the global default 4943 priority used by gnutls. This can be useful if the system 4944 administrator needs to use a weaker set of crypto priorities for 4945 QEMU without potentially forcing the weakness onto all 4946 applications. Or conversely if one wants wants a stronger 4947 default for QEMU than for all other applications, they can do 4948 this through this parameter. Its format is a gnutls priority 4949 string as described at 4950 https://gnutls.org/manual/html_node/Priority-Strings.html. 4951 4952 ``-object tls-cipher-suites,id=id,priority=priority`` 4953 Creates a TLS cipher suites object, which can be used to control 4954 the TLS cipher/protocol algorithms that applications are permitted 4955 to use. 4956 4957 The ``id`` parameter is a unique ID which frontends will use to 4958 access the ordered list of permitted TLS cipher suites from the 4959 host. 4960 4961 The ``priority`` parameter allows to override the global default 4962 priority used by gnutls. This can be useful if the system 4963 administrator needs to use a weaker set of crypto priorities for 4964 QEMU without potentially forcing the weakness onto all 4965 applications. Or conversely if one wants wants a stronger 4966 default for QEMU than for all other applications, they can do 4967 this through this parameter. Its format is a gnutls priority 4968 string as described at 4969 https://gnutls.org/manual/html_node/Priority-Strings.html. 4970 4971 An example of use of this object is to control UEFI HTTPS Boot. 4972 The tls-cipher-suites object exposes the ordered list of permitted 4973 TLS cipher suites from the host side to the guest firmware, via 4974 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER 4975 objects. The firmware uses the IANA_TLS_CIPHER array for configuring 4976 guest-side TLS. 4977 4978 In the following example, the priority at which the host-side policy 4979 is retrieved is given by the ``priority`` property. 4980 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to 4981 refer to /etc/crypto-policies/back-ends/gnutls.config. 4982 4983 .. parsed-literal:: 4984 4985 # |qemu_system| \\ 4986 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\ 4987 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 4988 4989 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` 4990 Interval t can't be 0, this filter batches the packet delivery: 4991 all packets arriving in a given interval on netdev netdevid are 4992 delayed until the end of the interval. Interval is in 4993 microseconds. ``status`` is optional that indicate whether the 4994 netfilter is on (enabled) or off (disabled), the default status 4995 for netfilter will be 'on'. 4996 4997 queue all\|rx\|tx is an option that can be applied to any 4998 netfilter. 4999 5000 ``all``: the filter is attached both to the receive and the 5001 transmit queue of the netdev (default). 5002 5003 ``rx``: the filter is attached to the receive queue of the 5004 netdev, where it will receive packets sent to the netdev. 5005 5006 ``tx``: the filter is attached to the transmit queue of the 5007 netdev, where it will receive packets sent by the netdev. 5008 5009 position head\|tail\|id=<id> is an option to specify where the 5010 filter should be inserted in the filter list. It can be applied 5011 to any netfilter. 5012 5013 ``head``: the filter is inserted at the head of the filter list, 5014 before any existing filters. 5015 5016 ``tail``: the filter is inserted at the tail of the filter list, 5017 behind any existing filters (default). 5018 5019 ``id=<id>``: the filter is inserted before or behind the filter 5020 specified by <id>, see the insert option below. 5021 5022 insert behind\|before is an option to specify where to insert 5023 the new filter relative to the one specified with 5024 position=id=<id>. It can be applied to any netfilter. 5025 5026 ``before``: insert before the specified filter. 5027 5028 ``behind``: insert behind the specified filter (default). 5029 5030 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5031 filter-mirror on netdev netdevid,mirror net packet to 5032 chardevchardevid, if it has the vnet\_hdr\_support flag, 5033 filter-mirror will mirror packet with vnet\_hdr\_len. 5034 5035 ``-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]`` 5036 filter-redirector on netdev netdevid,redirect filter's net 5037 packet to chardev chardevid,and redirect indev's packet to 5038 filter.if it has the vnet\_hdr\_support flag, filter-redirector 5039 will redirect packet with vnet\_hdr\_len. Create a 5040 filter-redirector we need to differ outdev id from indev id, id 5041 can not be the same. we can just use indev or outdev, but at 5042 least one of indev or outdev need to be specified. 5043 5044 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5045 Filter-rewriter is a part of COLO project.It will rewrite tcp 5046 packet to secondary from primary to keep secondary tcp 5047 connection,and rewrite tcp packet to primary from secondary make 5048 tcp packet can be handled by client.if it has the 5049 vnet\_hdr\_support flag, we can parse packet with vnet header. 5050 5051 usage: colo secondary: -object 5052 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object 5053 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object 5054 filter-rewriter,id=rew0,netdev=hn0,queue=all 5055 5056 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]`` 5057 Dump the network traffic on netdev dev to the file specified by 5058 filename. At most len bytes (64k by default) per packet are 5059 stored. The file format is libpcap, so it can be analyzed with 5060 tools such as tcpdump or Wireshark. 5061 5062 ``-object colo-compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=chardevid,iothread=id[,vnet_hdr_support][,notify_dev=id][,compare_timeout=@var{ms}][,expired_scan_cycle=@var{ms}][,max_queue_size=@var{size}]`` 5063 Colo-compare gets packet from primary\_in chardevid and 5064 secondary\_in, then compare whether the payload of primary packet 5065 and secondary packet are the same. If same, it will output 5066 primary packet to out\_dev, else it will notify COLO-framework to do 5067 checkpoint and send primary packet to out\_dev. In order to 5068 improve efficiency, we need to put the task of comparison in 5069 another iothread. If it has the vnet\_hdr\_support flag, 5070 colo compare will send/recv packet with vnet\_hdr\_len. 5071 The compare\_timeout=@var{ms} determines the maximum time of the 5072 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms} 5073 is to set the period of scanning expired primary node network packets. 5074 The max\_queue\_size=@var{size} is to set the max compare queue 5075 size depend on user environment. 5076 If user want to use Xen COLO, need to add the notify\_dev to 5077 notify Xen colo-frame to do checkpoint. 5078 5079 COLO-compare must be used with the help of filter-mirror, 5080 filter-redirector and filter-rewriter. 5081 5082 :: 5083 5084 KVM COLO 5085 5086 primary: 5087 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5088 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5089 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5090 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5091 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5092 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5093 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5094 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5095 -object iothread,id=iothread1 5096 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5097 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5098 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5099 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 5100 5101 secondary: 5102 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5103 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5104 -chardev socket,id=red0,host=3.3.3.3,port=9003 5105 -chardev socket,id=red1,host=3.3.3.3,port=9004 5106 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5107 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5108 5109 5110 Xen COLO 5111 5112 primary: 5113 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5114 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5115 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5116 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5117 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5118 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5119 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5120 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5121 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off 5122 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5123 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5124 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5125 -object iothread,id=iothread1 5126 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 5127 5128 secondary: 5129 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5130 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5131 -chardev socket,id=red0,host=3.3.3.3,port=9003 5132 -chardev socket,id=red1,host=3.3.3.3,port=9004 5133 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5134 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5135 5136 If you want to know the detail of above command line, you can 5137 read the colo-compare git log. 5138 5139 ``-object cryptodev-backend-builtin,id=id[,queues=queues]`` 5140 Creates a cryptodev backend which executes crypto opreation from 5141 the QEMU cipher APIS. The id parameter is a unique ID that will 5142 be used to reference this cryptodev backend from the 5143 ``virtio-crypto`` device. The queues parameter is optional, 5144 which specify the queue number of cryptodev backend, the default 5145 of queues is 1. 5146 5147 .. parsed-literal:: 5148 5149 # |qemu_system| \\ 5150 [...] \\ 5151 -object cryptodev-backend-builtin,id=cryptodev0 \\ 5152 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5153 [...] 5154 5155 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]`` 5156 Creates a vhost-user cryptodev backend, backed by a chardev 5157 chardevid. The id parameter is a unique ID that will be used to 5158 reference this cryptodev backend from the ``virtio-crypto`` 5159 device. The chardev should be a unix domain socket backed one. 5160 The vhost-user uses a specifically defined protocol to pass 5161 vhost ioctl replacement messages to an application on the other 5162 end of the socket. The queues parameter is optional, which 5163 specify the queue number of cryptodev backend for multiqueue 5164 vhost-user, the default of queues is 1. 5165 5166 .. parsed-literal:: 5167 5168 # |qemu_system| \\ 5169 [...] \\ 5170 -chardev socket,id=chardev0,path=/path/to/socket \\ 5171 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\ 5172 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5173 [...] 5174 5175 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]`` 5176 \ 5177 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]`` 5178 Defines a secret to store a password, encryption key, or some 5179 other sensitive data. The sensitive data can either be passed 5180 directly via the data parameter, or indirectly via the file 5181 parameter. Using the data parameter is insecure unless the 5182 sensitive data is encrypted. 5183 5184 The sensitive data can be provided in raw format (the default), 5185 or base64. When encoded as JSON, the raw format only supports 5186 valid UTF-8 characters, so base64 is recommended for sending 5187 binary data. QEMU will convert from which ever format is 5188 provided to the format it needs internally. eg, an RBD password 5189 can be provided in raw format, even though it will be base64 5190 encoded when passed onto the RBD sever. 5191 5192 For added protection, it is possible to encrypt the data 5193 associated with a secret using the AES-256-CBC cipher. Use of 5194 encryption is indicated by providing the keyid and iv 5195 parameters. The keyid parameter provides the ID of a previously 5196 defined secret that contains the AES-256 decryption key. This 5197 key should be 32-bytes long and be base64 encoded. The iv 5198 parameter provides the random initialization vector used for 5199 encryption of this particular secret and should be a base64 5200 encrypted string of the 16-byte IV. 5201 5202 The simplest (insecure) usage is to provide the secret inline 5203 5204 .. parsed-literal:: 5205 5206 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw 5207 5208 The simplest secure usage is to provide the secret via a file 5209 5210 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object 5211 secret,id=sec0,file=mypasswd.txt,format=raw 5212 5213 For greater security, AES-256-CBC should be used. To illustrate 5214 usage, consider the openssl command line tool which can encrypt 5215 the data. Note that when encrypting, the plaintext must be 5216 padded to the cipher block size (32 bytes) using the standard 5217 PKCS#5/6 compatible padding algorithm. 5218 5219 First a master key needs to be created in base64 encoding: 5220 5221 :: 5222 5223 # openssl rand -base64 32 > key.b64 5224 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 5225 5226 Each secret to be encrypted needs to have a random 5227 initialization vector generated. These do not need to be kept 5228 secret 5229 5230 :: 5231 5232 # openssl rand -base64 16 > iv.b64 5233 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 5234 5235 The secret to be defined can now be encrypted, in this case 5236 we're telling openssl to base64 encode the result, but it could 5237 be left as raw bytes if desired. 5238 5239 :: 5240 5241 # SECRET=$(printf "letmein" | 5242 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 5243 5244 When launching QEMU, create a master secret pointing to 5245 ``key.b64`` and specify that to be used to decrypt the user 5246 password. Pass the contents of ``iv.b64`` to the second secret 5247 5248 .. parsed-literal:: 5249 5250 # |qemu_system| \\ 5251 -object secret,id=secmaster0,format=base64,file=key.b64 \\ 5252 -object secret,id=sec0,keyid=secmaster0,format=base64,\\ 5253 data=$SECRET,iv=$(<iv.b64) 5254 5255 ``-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,kernel-hashes=on|off]`` 5256 Create a Secure Encrypted Virtualization (SEV) guest object, 5257 which can be used to provide the guest memory encryption support 5258 on AMD processors. 5259 5260 When memory encryption is enabled, one of the physical address 5261 bit (aka the C-bit) is utilized to mark if a memory page is 5262 protected. The ``cbitpos`` is used to provide the C-bit 5263 position. The C-bit position is Host family dependent hence user 5264 must provide this value. On EPYC, the value should be 47. 5265 5266 When memory encryption is enabled, we loose certain bits in 5267 physical address space. The ``reduced-phys-bits`` is used to 5268 provide the number of bits we loose in physical address space. 5269 Similar to C-bit, the value is Host family dependent. On EPYC, 5270 the value should be 5. 5271 5272 The ``sev-device`` provides the device file to use for 5273 communicating with the SEV firmware running inside AMD Secure 5274 Processor. The default device is '/dev/sev'. If hardware 5275 supports memory encryption then /dev/sev devices are created by 5276 CCP driver. 5277 5278 The ``policy`` provides the guest policy to be enforced by the 5279 SEV firmware and restrict what configuration and operational 5280 commands can be performed on this guest by the hypervisor. The 5281 policy should be provided by the guest owner and is bound to the 5282 guest and cannot be changed throughout the lifetime of the 5283 guest. The default is 0. 5284 5285 If guest ``policy`` allows sharing the key with another SEV 5286 guest then ``handle`` can be use to provide handle of the guest 5287 from which to share the key. 5288 5289 The ``dh-cert-file`` and ``session-file`` provides the guest 5290 owner's Public Diffie-Hillman key defined in SEV spec. The PDH 5291 and session parameters are used for establishing a cryptographic 5292 session with the guest owner to negotiate keys used for 5293 attestation. The file must be encoded in base64. 5294 5295 The ``kernel-hashes`` adds the hashes of given kernel/initrd/ 5296 cmdline to a designated guest firmware page for measured Linux 5297 boot with -kernel. The default is off. (Since 6.2) 5298 5299 e.g to launch a SEV guest 5300 5301 .. parsed-literal:: 5302 5303 # |qemu_system_x86| \\ 5304 ...... \\ 5305 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \\ 5306 -machine ...,memory-encryption=sev0 \\ 5307 ..... 5308 5309 ``-object authz-simple,id=id,identity=string`` 5310 Create an authorization object that will control access to 5311 network services. 5312 5313 The ``identity`` parameter is identifies the user and its format 5314 depends on the network service that authorization object is 5315 associated with. For authorizing based on TLS x509 certificates, 5316 the identity must be the x509 distinguished name. Note that care 5317 must be taken to escape any commas in the distinguished name. 5318 5319 An example authorization object to validate a x509 distinguished 5320 name would look like: 5321 5322 .. parsed-literal:: 5323 5324 # |qemu_system| \\ 5325 ... \\ 5326 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\ 5327 ... 5328 5329 Note the use of quotes due to the x509 distinguished name 5330 containing whitespace, and escaping of ','. 5331 5332 ``-object authz-listfile,id=id,filename=path,refresh=on|off`` 5333 Create an authorization object that will control access to 5334 network services. 5335 5336 The ``filename`` parameter is the fully qualified path to a file 5337 containing the access control list rules in JSON format. 5338 5339 An example set of rules that match against SASL usernames might 5340 look like: 5341 5342 :: 5343 5344 { 5345 "rules": [ 5346 { "match": "fred", "policy": "allow", "format": "exact" }, 5347 { "match": "bob", "policy": "allow", "format": "exact" }, 5348 { "match": "danb", "policy": "deny", "format": "glob" }, 5349 { "match": "dan*", "policy": "allow", "format": "exact" }, 5350 ], 5351 "policy": "deny" 5352 } 5353 5354 When checking access the object will iterate over all the rules 5355 and the first rule to match will have its ``policy`` value 5356 returned as the result. If no rules match, then the default 5357 ``policy`` value is returned. 5358 5359 The rules can either be an exact string match, or they can use 5360 the simple UNIX glob pattern matching to allow wildcards to be 5361 used. 5362 5363 If ``refresh`` is set to true the file will be monitored and 5364 automatically reloaded whenever its content changes. 5365 5366 As with the ``authz-simple`` object, the format of the identity 5367 strings being matched depends on the network service, but is 5368 usually a TLS x509 distinguished name, or a SASL username. 5369 5370 An example authorization object to validate a SASL username 5371 would look like: 5372 5373 .. parsed-literal:: 5374 5375 # |qemu_system| \\ 5376 ... \\ 5377 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\ 5378 ... 5379 5380 ``-object authz-pam,id=id,service=string`` 5381 Create an authorization object that will control access to 5382 network services. 5383 5384 The ``service`` parameter provides the name of a PAM service to 5385 use for authorization. It requires that a file 5386 ``/etc/pam.d/service`` exist to provide the configuration for 5387 the ``account`` subsystem. 5388 5389 An example authorization object to validate a TLS x509 5390 distinguished name would look like: 5391 5392 .. parsed-literal:: 5393 5394 # |qemu_system| \\ 5395 ... \\ 5396 -object authz-pam,id=auth0,service=qemu-vnc \\ 5397 ... 5398 5399 There would then be a corresponding config file for PAM at 5400 ``/etc/pam.d/qemu-vnc`` that contains: 5401 5402 :: 5403 5404 account requisite pam_listfile.so item=user sense=allow \ 5405 file=/etc/qemu/vnc.allow 5406 5407 Finally the ``/etc/qemu/vnc.allow`` file would contain the list 5408 of x509 distingished names that are permitted access 5409 5410 :: 5411 5412 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 5413 5414 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch`` 5415 Creates a dedicated event loop thread that devices can be 5416 assigned to. This is known as an IOThread. By default device 5417 emulation happens in vCPU threads or the main event loop thread. 5418 This can become a scalability bottleneck. IOThreads allow device 5419 emulation and I/O to run on other host CPUs. 5420 5421 The ``id`` parameter is a unique ID that will be used to 5422 reference this IOThread from ``-device ...,iothread=id``. 5423 Multiple devices can be assigned to an IOThread. Note that not 5424 all devices support an ``iothread`` parameter. 5425 5426 The ``query-iothreads`` QMP command lists IOThreads and reports 5427 their thread IDs so that the user can configure host CPU 5428 pinning/affinity. 5429 5430 IOThreads use an adaptive polling algorithm to reduce event loop 5431 latency. Instead of entering a blocking system call to monitor 5432 file descriptors and then pay the cost of being woken up when an 5433 event occurs, the polling algorithm spins waiting for events for 5434 a short time. The algorithm's default parameters are suitable 5435 for many cases but can be adjusted based on knowledge of the 5436 workload and/or host device latency. 5437 5438 The ``poll-max-ns`` parameter is the maximum number of 5439 nanoseconds to busy wait for events. Polling can be disabled by 5440 setting this value to 0. 5441 5442 The ``poll-grow`` parameter is the multiplier used to increase 5443 the polling time when the algorithm detects it is missing events 5444 due to not polling long enough. 5445 5446 The ``poll-shrink`` parameter is the divisor used to decrease 5447 the polling time when the algorithm detects it is spending too 5448 long polling without encountering events. 5449 5450 The ``aio-max-batch`` parameter is the maximum number of requests 5451 in a batch for the AIO engine, 0 means that the engine will use 5452 its default. 5453 5454 The IOThread parameters can be modified at run-time using the 5455 ``qom-set`` command (where ``iothread1`` is the IOThread's 5456 ``id``): 5457 5458 :: 5459 5460 (qemu) qom-set /objects/iothread1 poll-max-ns 100000 5461ERST 5462 5463 5464HXCOMM This is the last statement. Insert new options before this line! 5465 5466#undef DEF 5467#undef DEFHEADING 5468#undef ARCHHEADING 5469
