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 The following sub-option defines a CPU topology hierarchy (2 sockets 281 totally on the machine, 2 clusters per socket, 2 cores per cluster, 282 2 threads per core) for ARM virt machines which support sockets/clusters 283 /cores/threads. Some members of the option can be omitted but their values 284 will be automatically computed: 285 286 :: 287 288 -smp 16,sockets=2,clusters=2,cores=2,threads=2,maxcpus=16 289 290 Historically preference was given to the coarsest topology parameters 291 when computing missing values (ie sockets preferred over cores, which 292 were preferred over threads), however, this behaviour is considered 293 liable to change. Prior to 6.2 the preference was sockets over cores 294 over threads. Since 6.2 the preference is cores over sockets over threads. 295 296 For example, the following option defines a machine board with 2 sockets 297 of 1 core before 6.2 and 1 socket of 2 cores after 6.2: 298 299 :: 300 301 -smp 2 302ERST 303 304DEF("numa", HAS_ARG, QEMU_OPTION_numa, 305 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 306 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 307 "-numa dist,src=source,dst=destination,val=distance\n" 308 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n" 309 "-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" 310 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n", 311 QEMU_ARCH_ALL) 312SRST 313``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 314 \ 315``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 316 \ 317``-numa dist,src=source,dst=destination,val=distance`` 318 \ 319``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]`` 320 \ 321``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=tpye[,latency=lat][,bandwidth=bw]`` 322 \ 323``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]`` 324 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA 325 distance from a source node to a destination node. Set the ACPI 326 Heterogeneous Memory Attributes for the given nodes. 327 328 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and 329 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a 330 contiguous range of CPU indexes (or a single VCPU if lastcpu is 331 omitted). A non-contiguous set of VCPUs can be represented by 332 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is 333 omitted on all nodes, VCPUs are automatically split between them. 334 335 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a 336 NUMA node: 337 338 :: 339 340 -numa node,cpus=0-2,cpus=5 341 342 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option 343 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to 344 assign CPU objects to a node using topology layout properties of 345 CPU. The set of properties is machine specific, and depends on used 346 machine type/'\ ``smp``\ ' options. It could be queried with 347 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ ' 348 property specifies node to which CPU object will be assigned, it's 349 required for node to be declared with '\ ``node``\ ' option before 350 it's used with '\ ``cpu``\ ' option. 351 352 For example: 353 354 :: 355 356 -M pc \ 357 -smp 1,sockets=2,maxcpus=2 \ 358 -numa node,nodeid=0 -numa node,nodeid=1 \ 359 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 360 361 Legacy '\ ``mem``\ ' assigns a given RAM amount to a node (not supported 362 for 5.1 and newer machine types). '\ ``memdev``\ ' assigns RAM from 363 a given memory backend device to a node. If '\ ``mem``\ ' and 364 '\ ``memdev``\ ' are omitted in all nodes, RAM is split equally between them. 365 366 367 '\ ``mem``\ ' and '\ ``memdev``\ ' are mutually exclusive. 368 Furthermore, if one node uses '\ ``memdev``\ ', all of them have to 369 use it. 370 371 '\ ``initiator``\ ' is an additional option that points to an 372 initiator NUMA node that has best performance (the lowest latency or 373 largest bandwidth) to this NUMA node. Note that this option can be 374 set only when the machine property 'hmat' is set to 'on'. 375 376 Following example creates a machine with 2 NUMA nodes, node 0 has 377 CPU. node 1 has only memory, and its initiator is node 0. Note that 378 because node 0 has CPU, by default the initiator of node 0 is itself 379 and must be itself. 380 381 :: 382 383 -machine hmat=on \ 384 -m 2G,slots=2,maxmem=4G \ 385 -object memory-backend-ram,size=1G,id=m0 \ 386 -object memory-backend-ram,size=1G,id=m1 \ 387 -numa node,nodeid=0,memdev=m0 \ 388 -numa node,nodeid=1,memdev=m1,initiator=0 \ 389 -smp 2,sockets=2,maxcpus=2 \ 390 -numa cpu,node-id=0,socket-id=0 \ 391 -numa cpu,node-id=0,socket-id=1 392 393 source and destination are NUMA node IDs. distance is the NUMA 394 distance from source to destination. The distance from a node to 395 itself is always 10. If any pair of nodes is given a distance, then 396 all pairs must be given distances. Although, when distances are only 397 given in one direction for each pair of nodes, then the distances in 398 the opposite directions are assumed to be the same. If, however, an 399 asymmetrical pair of distances is given for even one node pair, then 400 all node pairs must be provided distance values for both directions, 401 even when they are symmetrical. When a node is unreachable from 402 another node, set the pair's distance to 255. 403 404 Note that the -``numa`` option doesn't allocate any of the specified 405 resources, it just assigns existing resources to NUMA nodes. This 406 means that one still has to use the ``-m``, ``-smp`` options to 407 allocate RAM and VCPUs respectively. 408 409 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth 410 Information between initiator and target NUMA nodes in ACPI 411 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can 412 create memory requests, usually it has one or more processors. 413 Target NUMA node contains addressable memory. 414 415 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is 416 the memory hierarchy of the target NUMA node: if hierarchy is 417 'memory', the structure represents the memory performance; if 418 hierarchy is 'first-level\|second-level\|third-level', this 419 structure represents aggregated performance of memory side caches 420 for each domain. type of 'data-type' is type of data represented by 421 this structure instance: if 'hierarchy' is 'memory', 'data-type' is 422 'access\|read\|write' latency or 'access\|read\|write' bandwidth of 423 the target memory; if 'hierarchy' is 424 'first-level\|second-level\|third-level', 'data-type' is 425 'access\|read\|write' hit latency or 'access\|read\|write' hit 426 bandwidth of the target memory side cache. 427 428 lat is latency value in nanoseconds. bw is bandwidth value, the 429 possible value and units are NUM[M\|G\|T], mean that the bandwidth 430 value are NUM byte per second (or MB/s, GB/s or TB/s depending on 431 used suffix). Note that if latency or bandwidth value is 0, means 432 the corresponding latency or bandwidth information is not provided. 433 434 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory 435 belongs. size is the size of memory side cache in bytes. level is 436 the cache level described in this structure, note that the cache 437 level 0 should not be used with '\ ``hmat-cache``\ ' option. 438 associativity is the cache associativity, the possible value is 439 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy 440 is the write policy. line is the cache Line size in bytes. 441 442 For example, the following options describe 2 NUMA nodes. Node 0 has 443 2 cpus and a ram, node 1 has only a ram. The processors in node 0 444 access memory in node 0 with access-latency 5 nanoseconds, 445 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access 446 memory in NUMA node 1 with access-latency 10 nanoseconds, 447 access-bandwidth is 100 MB/s. And for memory side cache information, 448 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB, 449 policy is write-back, the cache Line size is 8 bytes: 450 451 :: 452 453 -machine hmat=on \ 454 -m 2G \ 455 -object memory-backend-ram,size=1G,id=m0 \ 456 -object memory-backend-ram,size=1G,id=m1 \ 457 -smp 2,sockets=2,maxcpus=2 \ 458 -numa node,nodeid=0,memdev=m0 \ 459 -numa node,nodeid=1,memdev=m1,initiator=0 \ 460 -numa cpu,node-id=0,socket-id=0 \ 461 -numa cpu,node-id=0,socket-id=1 \ 462 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \ 463 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \ 464 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \ 465 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \ 466 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \ 467 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8 468ERST 469 470DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 471 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 472 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 473SRST 474``-add-fd fd=fd,set=set[,opaque=opaque]`` 475 Add a file descriptor to an fd set. Valid options are: 476 477 ``fd=fd`` 478 This option defines the file descriptor of which a duplicate is 479 added to fd set. The file descriptor cannot be stdin, stdout, or 480 stderr. 481 482 ``set=set`` 483 This option defines the ID of the fd set to add the file 484 descriptor to. 485 486 ``opaque=opaque`` 487 This option defines a free-form string that can be used to 488 describe fd. 489 490 You can open an image using pre-opened file descriptors from an fd 491 set: 492 493 .. parsed-literal:: 494 495 |qemu_system| \\ 496 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 497 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 498 -drive file=/dev/fdset/2,index=0,media=disk 499ERST 500 501DEF("set", HAS_ARG, QEMU_OPTION_set, 502 "-set group.id.arg=value\n" 503 " set <arg> parameter for item <id> of type <group>\n" 504 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 505SRST 506``-set group.id.arg=value`` 507 Set parameter arg for item id of type group 508ERST 509 510DEF("global", HAS_ARG, QEMU_OPTION_global, 511 "-global driver.property=value\n" 512 "-global driver=driver,property=property,value=value\n" 513 " set a global default for a driver property\n", 514 QEMU_ARCH_ALL) 515SRST 516``-global driver.prop=value`` 517 \ 518``-global driver=driver,property=property,value=value`` 519 Set default value of driver's property prop to value, e.g.: 520 521 .. parsed-literal:: 522 523 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img 524 525 In particular, you can use this to set driver properties for devices 526 which are created automatically by the machine model. To create a 527 device which is not created automatically and set properties on it, 528 use -``device``. 529 530 -global driver.prop=value is shorthand for -global 531 driver=driver,property=prop,value=value. The longhand syntax works 532 even when driver contains a dot. 533ERST 534 535DEF("boot", HAS_ARG, QEMU_OPTION_boot, 536 "-boot [order=drives][,once=drives][,menu=on|off]\n" 537 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 538 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 539 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 540 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 541 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 542 QEMU_ARCH_ALL) 543SRST 544``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]`` 545 Specify boot order drives as a string of drive letters. Valid drive 546 letters depend on the target architecture. The x86 PC uses: a, b 547 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p 548 (Etherboot from network adapter 1-4), hard disk boot is the default. 549 To apply a particular boot order only on the first startup, specify 550 it via ``once``. Note that the ``order`` or ``once`` parameter 551 should not be used together with the ``bootindex`` property of 552 devices, since the firmware implementations normally do not support 553 both at the same time. 554 555 Interactive boot menus/prompts can be enabled via ``menu=on`` as far 556 as firmware/BIOS supports them. The default is non-interactive boot. 557 558 A splash picture could be passed to bios, enabling user to show it 559 as logo, when option splash=sp\_name is given and menu=on, If 560 firmware/BIOS supports them. Currently Seabios for X86 system 561 support it. limitation: The splash file could be a jpeg file or a 562 BMP file in 24 BPP format(true color). The resolution should be 563 supported by the SVGA mode, so the recommended is 320x240, 640x480, 564 800x640. 565 566 A timeout could be passed to bios, guest will pause for rb\_timeout 567 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will 568 not reboot, qemu passes '-1' to bios by default. Currently Seabios 569 for X86 system support it. 570 571 Do strict boot via ``strict=on`` as far as firmware/BIOS supports 572 it. This only effects when boot priority is changed by bootindex 573 options. The default is non-strict boot. 574 575 .. parsed-literal:: 576 577 # try to boot from network first, then from hard disk 578 |qemu_system_x86| -boot order=nc 579 # boot from CD-ROM first, switch back to default order after reboot 580 |qemu_system_x86| -boot once=d 581 # boot with a splash picture for 5 seconds. 582 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000 583 584 Note: The legacy format '-boot drives' is still supported but its 585 use is discouraged as it may be removed from future versions. 586ERST 587 588DEF("m", HAS_ARG, QEMU_OPTION_m, 589 "-m [size=]megs[,slots=n,maxmem=size]\n" 590 " configure guest RAM\n" 591 " size: initial amount of guest memory\n" 592 " slots: number of hotplug slots (default: none)\n" 593 " maxmem: maximum amount of guest memory (default: none)\n" 594 "NOTE: Some architectures might enforce a specific granularity\n", 595 QEMU_ARCH_ALL) 596SRST 597``-m [size=]megs[,slots=n,maxmem=size]`` 598 Sets guest startup RAM size to megs megabytes. Default is 128 MiB. 599 Optionally, a suffix of "M" or "G" can be used to signify a value in 600 megabytes or gigabytes respectively. Optional pair slots, maxmem 601 could be used to set amount of hotpluggable memory slots and maximum 602 amount of memory. Note that maxmem must be aligned to the page size. 603 604 For example, the following command-line sets the guest startup RAM 605 size to 1GB, creates 3 slots to hotplug additional memory and sets 606 the maximum memory the guest can reach to 4GB: 607 608 .. parsed-literal:: 609 610 |qemu_system| -m 1G,slots=3,maxmem=4G 611 612 If slots and maxmem are not specified, memory hotplug won't be 613 enabled and the guest startup RAM will never increase. 614ERST 615 616DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 617 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 618SRST 619``-mem-path path`` 620 Allocate guest RAM from a temporarily created file in path. 621ERST 622 623DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 624 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 625 QEMU_ARCH_ALL) 626SRST 627``-mem-prealloc`` 628 Preallocate memory when using -mem-path. 629ERST 630 631DEF("k", HAS_ARG, QEMU_OPTION_k, 632 "-k language use keyboard layout (for example 'fr' for French)\n", 633 QEMU_ARCH_ALL) 634SRST 635``-k language`` 636 Use keyboard layout language (for example ``fr`` for French). This 637 option is only needed where it is not easy to get raw PC keycodes 638 (e.g. on Macs, with some X11 servers or with a VNC or curses 639 display). You don't normally need to use it on PC/Linux or 640 PC/Windows hosts. 641 642 The available layouts are: 643 644 :: 645 646 ar de-ch es fo fr-ca hu ja mk no pt-br sv 647 da en-gb et fr fr-ch is lt nl pl ru th 648 de en-us fi fr-be hr it lv nl-be pt sl tr 649 650 The default is ``en-us``. 651ERST 652 653 654HXCOMM Deprecated by -audiodev 655DEF("audio-help", 0, QEMU_OPTION_audio_help, 656 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 657 QEMU_ARCH_ALL) 658SRST 659``-audio-help`` 660 Will show the -audiodev equivalent of the currently specified 661 (deprecated) environment variables. 662ERST 663 664DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 665 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 666 " specifies the audio backend to use\n" 667 " id= identifier of the backend\n" 668 " timer-period= timer period in microseconds\n" 669 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 670 " in|out.fixed-settings= use fixed settings for host audio\n" 671 " in|out.frequency= frequency to use with fixed settings\n" 672 " in|out.channels= number of channels to use with fixed settings\n" 673 " in|out.format= sample format to use with fixed settings\n" 674 " valid values: s8, s16, s32, u8, u16, u32, f32\n" 675 " in|out.voices= number of voices to use\n" 676 " in|out.buffer-length= length of buffer in microseconds\n" 677 "-audiodev none,id=id,[,prop[=value][,...]]\n" 678 " dummy driver that discards all output\n" 679#ifdef CONFIG_AUDIO_ALSA 680 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 681 " in|out.dev= name of the audio device to use\n" 682 " in|out.period-length= length of period in microseconds\n" 683 " in|out.try-poll= attempt to use poll mode\n" 684 " threshold= threshold (in microseconds) when playback starts\n" 685#endif 686#ifdef CONFIG_AUDIO_COREAUDIO 687 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 688 " in|out.buffer-count= number of buffers\n" 689#endif 690#ifdef CONFIG_AUDIO_DSOUND 691 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 692 " latency= add extra latency to playback in microseconds\n" 693#endif 694#ifdef CONFIG_AUDIO_OSS 695 "-audiodev oss,id=id[,prop[=value][,...]]\n" 696 " in|out.dev= path of the audio device to use\n" 697 " in|out.buffer-count= number of buffers\n" 698 " in|out.try-poll= attempt to use poll mode\n" 699 " try-mmap= try using memory mapped access\n" 700 " exclusive= open device in exclusive mode\n" 701 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 702#endif 703#ifdef CONFIG_AUDIO_PA 704 "-audiodev pa,id=id[,prop[=value][,...]]\n" 705 " server= PulseAudio server address\n" 706 " in|out.name= source/sink device name\n" 707 " in|out.latency= desired latency in microseconds\n" 708#endif 709#ifdef CONFIG_AUDIO_SDL 710 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 711 " in|out.buffer-count= number of buffers\n" 712#endif 713#ifdef CONFIG_SPICE 714 "-audiodev spice,id=id[,prop[=value][,...]]\n" 715#endif 716#ifdef CONFIG_DBUS_DISPLAY 717 "-audiodev dbus,id=id[,prop[=value][,...]]\n" 718#endif 719 "-audiodev wav,id=id[,prop[=value][,...]]\n" 720 " path= path of wav file to record\n", 721 QEMU_ARCH_ALL) 722SRST 723``-audiodev [driver=]driver,id=id[,prop[=value][,...]]`` 724 Adds a new audio backend driver identified by id. There are global 725 and driver specific properties. Some values can be set differently 726 for input and output, they're marked with ``in|out.``. You can set 727 the input's property with ``in.prop`` and the output's property with 728 ``out.prop``. For example: 729 730 :: 731 732 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 733 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 734 735 NOTE: parameter validation is known to be incomplete, in many cases 736 specifying an invalid option causes QEMU to print an error message 737 and continue emulation without sound. 738 739 Valid global options are: 740 741 ``id=identifier`` 742 Identifies the audio backend. 743 744 ``timer-period=period`` 745 Sets the timer period used by the audio subsystem in 746 microseconds. Default is 10000 (10 ms). 747 748 ``in|out.mixing-engine=on|off`` 749 Use QEMU's mixing engine to mix all streams inside QEMU and 750 convert audio formats when not supported by the backend. When 751 off, fixed-settings must be off too. Note that disabling this 752 option means that the selected backend must support multiple 753 streams and the audio formats used by the virtual cards, 754 otherwise you'll get no sound. It's not recommended to disable 755 this option unless you want to use 5.1 or 7.1 audio, as mixing 756 engine only supports mono and stereo audio. Default is on. 757 758 ``in|out.fixed-settings=on|off`` 759 Use fixed settings for host audio. When off, it will change 760 based on how the guest opens the sound card. In this case you 761 must not specify frequency, channels or format. Default is on. 762 763 ``in|out.frequency=frequency`` 764 Specify the frequency to use when using fixed-settings. Default 765 is 44100Hz. 766 767 ``in|out.channels=channels`` 768 Specify the number of channels to use when using fixed-settings. 769 Default is 2 (stereo). 770 771 ``in|out.format=format`` 772 Specify the sample format to use when using fixed-settings. 773 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``, 774 ``u32``, ``f32``. Default is ``s16``. 775 776 ``in|out.voices=voices`` 777 Specify the number of voices to use. Default is 1. 778 779 ``in|out.buffer-length=usecs`` 780 Sets the size of the buffer in microseconds. 781 782``-audiodev none,id=id[,prop[=value][,...]]`` 783 Creates a dummy backend that discards all outputs. This backend has 784 no backend specific properties. 785 786``-audiodev alsa,id=id[,prop[=value][,...]]`` 787 Creates backend using the ALSA. This backend is only available on 788 Linux. 789 790 ALSA specific options are: 791 792 ``in|out.dev=device`` 793 Specify the ALSA device to use for input and/or output. Default 794 is ``default``. 795 796 ``in|out.period-length=usecs`` 797 Sets the period length in microseconds. 798 799 ``in|out.try-poll=on|off`` 800 Attempt to use poll mode with the device. Default is on. 801 802 ``threshold=threshold`` 803 Threshold (in microseconds) when playback starts. Default is 0. 804 805``-audiodev coreaudio,id=id[,prop[=value][,...]]`` 806 Creates a backend using Apple's Core Audio. This backend is only 807 available on Mac OS and only supports playback. 808 809 Core Audio specific options are: 810 811 ``in|out.buffer-count=count`` 812 Sets the count of the buffers. 813 814``-audiodev dsound,id=id[,prop[=value][,...]]`` 815 Creates a backend using Microsoft's DirectSound. This backend is 816 only available on Windows and only supports playback. 817 818 DirectSound specific options are: 819 820 ``latency=usecs`` 821 Add extra usecs microseconds latency to playback. Default is 822 10000 (10 ms). 823 824``-audiodev oss,id=id[,prop[=value][,...]]`` 825 Creates a backend using OSS. This backend is available on most 826 Unix-like systems. 827 828 OSS specific options are: 829 830 ``in|out.dev=device`` 831 Specify the file name of the OSS device to use. Default is 832 ``/dev/dsp``. 833 834 ``in|out.buffer-count=count`` 835 Sets the count of the buffers. 836 837 ``in|out.try-poll=on|of`` 838 Attempt to use poll mode with the device. Default is on. 839 840 ``try-mmap=on|off`` 841 Try using memory mapped device access. Default is off. 842 843 ``exclusive=on|off`` 844 Open the device in exclusive mode (vmix won't work in this 845 case). Default is off. 846 847 ``dsp-policy=policy`` 848 Sets the timing policy (between 0 and 10, where smaller number 849 means smaller latency but higher CPU usage). Use -1 to use 850 buffer sizes specified by ``buffer`` and ``buffer-count``. This 851 option is ignored if you do not have OSS 4. Default is 5. 852 853``-audiodev pa,id=id[,prop[=value][,...]]`` 854 Creates a backend using PulseAudio. This backend is available on 855 most systems. 856 857 PulseAudio specific options are: 858 859 ``server=server`` 860 Sets the PulseAudio server to connect to. 861 862 ``in|out.name=sink`` 863 Use the specified source/sink for recording/playback. 864 865 ``in|out.latency=usecs`` 866 Desired latency in microseconds. The PulseAudio server will try 867 to honor this value but actual latencies may be lower or higher. 868 869``-audiodev sdl,id=id[,prop[=value][,...]]`` 870 Creates a backend using SDL. This backend is available on most 871 systems, but you should use your platform's native backend if 872 possible. 873 874 SDL specific options are: 875 876 ``in|out.buffer-count=count`` 877 Sets the count of the buffers. 878 879``-audiodev spice,id=id[,prop[=value][,...]]`` 880 Creates a backend that sends audio through SPICE. This backend 881 requires ``-spice`` and automatically selected in that case, so 882 usually you can ignore this option. This backend has no backend 883 specific properties. 884 885``-audiodev wav,id=id[,prop[=value][,...]]`` 886 Creates a backend that writes audio to a WAV file. 887 888 Backend specific options are: 889 890 ``path=path`` 891 Write recorded audio into the specified file. Default is 892 ``qemu.wav``. 893ERST 894 895DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 896 "-soundhw c1,... enable audio support\n" 897 " and only specified sound cards (comma separated list)\n" 898 " use '-soundhw help' to get the list of supported cards\n" 899 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 900SRST 901``-soundhw card1[,card2,...] or -soundhw all`` 902 Enable audio and selected sound hardware. Use 'help' to print all 903 available sound hardware. For example: 904 905 .. parsed-literal:: 906 907 |qemu_system_x86| -soundhw sb16,adlib disk.img 908 |qemu_system_x86| -soundhw es1370 disk.img 909 |qemu_system_x86| -soundhw ac97 disk.img 910 |qemu_system_x86| -soundhw hda disk.img 911 |qemu_system_x86| -soundhw all disk.img 912 |qemu_system_x86| -soundhw help 913 914 Note that Linux's i810\_audio OSS kernel (for AC97) module might 915 require manually specifying clocking. 916 917 :: 918 919 modprobe i810_audio clocking=48000 920ERST 921 922DEF("device", HAS_ARG, QEMU_OPTION_device, 923 "-device driver[,prop[=value][,...]]\n" 924 " add device (based on driver)\n" 925 " prop=value,... sets driver properties\n" 926 " use '-device help' to print all possible drivers\n" 927 " use '-device driver,help' to print all possible properties\n", 928 QEMU_ARCH_ALL) 929SRST 930``-device driver[,prop[=value][,...]]`` 931 Add device driver. prop=value sets driver properties. Valid 932 properties depend on the driver. To get help on possible drivers and 933 properties, use ``-device help`` and ``-device driver,help``. 934 935 Some drivers are: 936 937``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]`` 938 Add an IPMI BMC. This is a simulation of a hardware management 939 interface processor that normally sits on a system. It provides a 940 watchdog and the ability to reset and power control the system. You 941 need to connect this to an IPMI interface to make it useful 942 943 The IPMI slave address to use for the BMC. The default is 0x20. This 944 address is the BMC's address on the I2C network of management 945 controllers. If you don't know what this means, it is safe to ignore 946 it. 947 948 ``id=id`` 949 The BMC id for interfaces to use this device. 950 951 ``slave_addr=val`` 952 Define slave address to use for the BMC. The default is 0x20. 953 954 ``sdrfile=file`` 955 file containing raw Sensor Data Records (SDR) data. The default 956 is none. 957 958 ``fruareasize=val`` 959 size of a Field Replaceable Unit (FRU) area. The default is 960 1024. 961 962 ``frudatafile=file`` 963 file containing raw Field Replaceable Unit (FRU) inventory data. 964 The default is none. 965 966 ``guid=uuid`` 967 value for the GUID for the BMC, in standard UUID format. If this 968 is set, get "Get GUID" command to the BMC will return it. 969 Otherwise "Get GUID" will return an error. 970 971``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]`` 972 Add a connection to an external IPMI BMC simulator. Instead of 973 locally emulating the BMC like the above item, instead connect to an 974 external entity that provides the IPMI services. 975 976 A connection is made to an external BMC simulator. If you do this, 977 it is strongly recommended that you use the "reconnect=" chardev 978 option to reconnect to the simulator if the connection is lost. Note 979 that if this is not used carefully, it can be a security issue, as 980 the interface has the ability to send resets, NMIs, and power off 981 the VM. It's best if QEMU makes a connection to an external 982 simulator running on a secure port on localhost, so neither the 983 simulator nor QEMU is exposed to any outside network. 984 985 See the "lanserv/README.vm" file in the OpenIPMI library for more 986 details on the external interface. 987 988``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]`` 989 Add a KCS IPMI interafce on the ISA bus. This also adds a 990 corresponding ACPI and SMBIOS entries, if appropriate. 991 992 ``bmc=id`` 993 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern 994 above. 995 996 ``ioport=val`` 997 Define the I/O address of the interface. The default is 0xca0 998 for KCS. 999 1000 ``irq=val`` 1001 Define the interrupt to use. The default is 5. To disable 1002 interrupts, set this to 0. 1003 1004``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]`` 1005 Like the KCS interface, but defines a BT interface. The default port 1006 is 0xe4 and the default interrupt is 5. 1007 1008``-device pci-ipmi-kcs,bmc=id`` 1009 Add a KCS IPMI interafce on the PCI bus. 1010 1011 ``bmc=id`` 1012 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 1013 1014``-device pci-ipmi-bt,bmc=id`` 1015 Like the KCS interface, but defines a BT interface on the PCI bus. 1016 1017``-device intel-iommu[,option=...]`` 1018 This is only supported by ``-machine q35``, which will enable Intel VT-d 1019 emulation within the guest. It supports below options: 1020 1021 ``intremap=on|off`` (default: auto) 1022 This enables interrupt remapping feature. It's required to enable 1023 complete x2apic. Currently it only supports kvm kernel-irqchip modes 1024 ``off`` or ``split``, while full kernel-irqchip is not yet supported. 1025 The default value is "auto", which will be decided by the mode of 1026 kernel-irqchip. 1027 1028 ``caching-mode=on|off`` (default: off) 1029 This enables caching mode for the VT-d emulated device. When 1030 caching-mode is enabled, each guest DMA buffer mapping will generate an 1031 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in 1032 a synchronous way. It is required for ``-device vfio-pci`` to work 1033 with the VT-d device, because host assigned devices requires to setup 1034 the DMA mapping on the host before guest DMA starts. 1035 1036 ``device-iotlb=on|off`` (default: off) 1037 This enables device-iotlb capability for the emulated VT-d device. So 1038 far virtio/vhost should be the only real user for this parameter, 1039 paired with ats=on configured for the device. 1040 1041 ``aw-bits=39|48`` (default: 39) 1042 This decides the address width of IOVA address space. The address 1043 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for 1044 4-level IOMMU page tables. 1045 1046 Please also refer to the wiki page for general scenarios of VT-d 1047 emulation in QEMU: https://wiki.qemu.org/Features/VT-d. 1048 1049ERST 1050 1051DEF("name", HAS_ARG, QEMU_OPTION_name, 1052 "-name string1[,process=string2][,debug-threads=on|off]\n" 1053 " set the name of the guest\n" 1054 " string1 sets the window title and string2 the process name\n" 1055 " When debug-threads is enabled, individual threads are given a separate name\n" 1056 " NOTE: The thread names are for debugging and not a stable API.\n", 1057 QEMU_ARCH_ALL) 1058SRST 1059``-name name`` 1060 Sets the name of the guest. This name will be displayed in the SDL 1061 window caption. The name will also be used for the VNC server. Also 1062 optionally set the top visible process name in Linux. Naming of 1063 individual threads can also be enabled on Linux to aid debugging. 1064ERST 1065 1066DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 1067 "-uuid %08x-%04x-%04x-%04x-%012x\n" 1068 " specify machine UUID\n", QEMU_ARCH_ALL) 1069SRST 1070``-uuid uuid`` 1071 Set system UUID. 1072ERST 1073 1074DEFHEADING() 1075 1076DEFHEADING(Block device options:) 1077 1078DEF("fda", HAS_ARG, QEMU_OPTION_fda, 1079 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 1080DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 1081SRST 1082``-fda file`` 1083 \ 1084``-fdb file`` 1085 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in 1086 the System Emulation Users Guide). 1087ERST 1088 1089DEF("hda", HAS_ARG, QEMU_OPTION_hda, 1090 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 1091DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 1092DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 1093 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 1094DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 1095SRST 1096``-hda file`` 1097 \ 1098``-hdb file`` 1099 \ 1100``-hdc file`` 1101 \ 1102``-hdd file`` 1103 Use file as hard disk 0, 1, 2 or 3 image (see the :ref:`disk images` 1104 chapter in the System Emulation Users Guide). 1105ERST 1106 1107DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 1108 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 1109 QEMU_ARCH_ALL) 1110SRST 1111``-cdrom file`` 1112 Use file as CD-ROM image (you cannot use ``-hdc`` and ``-cdrom`` at 1113 the same time). You can use the host CD-ROM by using ``/dev/cdrom`` 1114 as filename. 1115ERST 1116 1117DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 1118 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 1119 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 1120 " [,read-only=on|off][,auto-read-only=on|off]\n" 1121 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 1122 " [,driver specific parameters...]\n" 1123 " configure a block backend\n", QEMU_ARCH_ALL) 1124SRST 1125``-blockdev option[,option[,option[,...]]]`` 1126 Define a new block driver node. Some of the options apply to all 1127 block drivers, other options are only accepted for a specific block 1128 driver. See below for a list of generic options and options for the 1129 most common block drivers. 1130 1131 Options that expect a reference to another node (e.g. ``file``) can 1132 be given in two ways. Either you specify the node name of an already 1133 existing node (file=node-name), or you define a new node inline, 1134 adding options for the referenced node after a dot 1135 (file.filename=path,file.aio=native). 1136 1137 A block driver node created with ``-blockdev`` can be used for a 1138 guest device by specifying its node name for the ``drive`` property 1139 in a ``-device`` argument that defines a block device. 1140 1141 ``Valid options for any block driver node:`` 1142 ``driver`` 1143 Specifies the block driver to use for the given node. 1144 1145 ``node-name`` 1146 This defines the name of the block driver node by which it 1147 will be referenced later. The name must be unique, i.e. it 1148 must not match the name of a different block driver node, or 1149 (if you use ``-drive`` as well) the ID of a drive. 1150 1151 If no node name is specified, it is automatically generated. 1152 The generated node name is not intended to be predictable 1153 and changes between QEMU invocations. For the top level, an 1154 explicit node name must be specified. 1155 1156 ``read-only`` 1157 Open the node read-only. Guest write attempts will fail. 1158 1159 Note that some block drivers support only read-only access, 1160 either generally or in certain configurations. In this case, 1161 the default value ``read-only=off`` does not work and the 1162 option must be specified explicitly. 1163 1164 ``auto-read-only`` 1165 If ``auto-read-only=on`` is set, QEMU may fall back to 1166 read-only usage even when ``read-only=off`` is requested, or 1167 even switch between modes as needed, e.g. depending on 1168 whether the image file is writable or whether a writing user 1169 is attached to the node. 1170 1171 ``force-share`` 1172 Override the image locking system of QEMU by forcing the 1173 node to utilize weaker shared access for permissions where 1174 it would normally request exclusive access. When there is 1175 the potential for multiple instances to have the same file 1176 open (whether this invocation of QEMU is the first or the 1177 second instance), both instances must permit shared access 1178 for the second instance to succeed at opening the file. 1179 1180 Enabling ``force-share=on`` requires ``read-only=on``. 1181 1182 ``cache.direct`` 1183 The host page cache can be avoided with ``cache.direct=on``. 1184 This will attempt to do disk IO directly to the guest's 1185 memory. QEMU may still perform an internal copy of the data. 1186 1187 ``cache.no-flush`` 1188 In case you don't care about data integrity over host 1189 failures, you can use ``cache.no-flush=on``. This option 1190 tells QEMU that it never needs to write any data to the disk 1191 but can instead keep things in cache. If anything goes 1192 wrong, like your host losing power, the disk storage getting 1193 disconnected accidentally, etc. your image will most 1194 probably be rendered unusable. 1195 1196 ``discard=discard`` 1197 discard is one of "ignore" (or "off") or "unmap" (or "on") 1198 and controls whether ``discard`` (also known as ``trim`` or 1199 ``unmap``) requests are ignored or passed to the filesystem. 1200 Some machine types may not support discard requests. 1201 1202 ``detect-zeroes=detect-zeroes`` 1203 detect-zeroes is "off", "on" or "unmap" and enables the 1204 automatic conversion of plain zero writes by the OS to 1205 driver specific optimized zero write commands. You may even 1206 choose "unmap" if discard is set to "unmap" to allow a zero 1207 write to be converted to an ``unmap`` operation. 1208 1209 ``Driver-specific options for file`` 1210 This is the protocol-level block driver for accessing regular 1211 files. 1212 1213 ``filename`` 1214 The path to the image file in the local filesystem 1215 1216 ``aio`` 1217 Specifies the AIO backend (threads/native/io_uring, 1218 default: threads) 1219 1220 ``locking`` 1221 Specifies whether the image file is protected with Linux OFD 1222 / POSIX locks. The default is to use the Linux Open File 1223 Descriptor API if available, otherwise no lock is applied. 1224 (auto/on/off, default: auto) 1225 1226 Example: 1227 1228 :: 1229 1230 -blockdev driver=file,node-name=disk,filename=disk.img 1231 1232 ``Driver-specific options for raw`` 1233 This is the image format block driver for raw images. It is 1234 usually stacked on top of a protocol level block driver such as 1235 ``file``. 1236 1237 ``file`` 1238 Reference to or definition of the data source block driver 1239 node (e.g. a ``file`` driver node) 1240 1241 Example 1: 1242 1243 :: 1244 1245 -blockdev driver=file,node-name=disk_file,filename=disk.img 1246 -blockdev driver=raw,node-name=disk,file=disk_file 1247 1248 Example 2: 1249 1250 :: 1251 1252 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1253 1254 ``Driver-specific options for qcow2`` 1255 This is the image format block driver for qcow2 images. It is 1256 usually stacked on top of a protocol level block driver such as 1257 ``file``. 1258 1259 ``file`` 1260 Reference to or definition of the data source block driver 1261 node (e.g. a ``file`` driver node) 1262 1263 ``backing`` 1264 Reference to or definition of the backing file block device 1265 (default is taken from the image file). It is allowed to 1266 pass ``null`` here in order to disable the default backing 1267 file. 1268 1269 ``lazy-refcounts`` 1270 Whether to enable the lazy refcounts feature (on/off; 1271 default is taken from the image file) 1272 1273 ``cache-size`` 1274 The maximum total size of the L2 table and refcount block 1275 caches in bytes (default: the sum of l2-cache-size and 1276 refcount-cache-size) 1277 1278 ``l2-cache-size`` 1279 The maximum size of the L2 table cache in bytes (default: if 1280 cache-size is not specified - 32M on Linux platforms, and 8M 1281 on non-Linux platforms; otherwise, as large as possible 1282 within the cache-size, while permitting the requested or the 1283 minimal refcount cache size) 1284 1285 ``refcount-cache-size`` 1286 The maximum size of the refcount block cache in bytes 1287 (default: 4 times the cluster size; or if cache-size is 1288 specified, the part of it which is not used for the L2 1289 cache) 1290 1291 ``cache-clean-interval`` 1292 Clean unused entries in the L2 and refcount caches. The 1293 interval is in seconds. The default value is 600 on 1294 supporting platforms, and 0 on other platforms. Setting it 1295 to 0 disables this feature. 1296 1297 ``pass-discard-request`` 1298 Whether discard requests to the qcow2 device should be 1299 forwarded to the data source (on/off; default: on if 1300 discard=unmap is specified, off otherwise) 1301 1302 ``pass-discard-snapshot`` 1303 Whether discard requests for the data source should be 1304 issued when a snapshot operation (e.g. deleting a snapshot) 1305 frees clusters in the qcow2 file (on/off; default: on) 1306 1307 ``pass-discard-other`` 1308 Whether discard requests for the data source should be 1309 issued on other occasions where a cluster gets freed 1310 (on/off; default: off) 1311 1312 ``overlap-check`` 1313 Which overlap checks to perform for writes to the image 1314 (none/constant/cached/all; default: cached). For details or 1315 finer granularity control refer to the QAPI documentation of 1316 ``blockdev-add``. 1317 1318 Example 1: 1319 1320 :: 1321 1322 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1323 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1324 1325 Example 2: 1326 1327 :: 1328 1329 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1330 1331 ``Driver-specific options for other drivers`` 1332 Please refer to the QAPI documentation of the ``blockdev-add`` 1333 QMP command. 1334ERST 1335 1336DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1337 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1338 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1339 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1340 " [,werror=ignore|stop|report|enospc][,id=name]\n" 1341 " [,aio=threads|native|io_uring]\n" 1342 " [,readonly=on|off][,copy-on-read=on|off]\n" 1343 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1344 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1345 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1346 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1347 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1348 " [[,iops_size=is]]\n" 1349 " [[,group=g]]\n" 1350 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1351SRST 1352``-drive option[,option[,option[,...]]]`` 1353 Define a new drive. This includes creating a block driver node (the 1354 backend) as well as a guest device, and is mostly a shortcut for 1355 defining the corresponding ``-blockdev`` and ``-device`` options. 1356 1357 ``-drive`` accepts all options that are accepted by ``-blockdev``. 1358 In addition, it knows the following options: 1359 1360 ``file=file`` 1361 This option defines which disk image (see the :ref:`disk images` 1362 chapter in the System Emulation Users Guide) to use with this drive. 1363 If the filename contains comma, you must double it (for instance, 1364 "file=my,,file" to use file "my,file"). 1365 1366 Special files such as iSCSI devices can be specified using 1367 protocol specific URLs. See the section for "Device URL Syntax" 1368 for more information. 1369 1370 ``if=interface`` 1371 This option defines on which type on interface the drive is 1372 connected. Available types are: ide, scsi, sd, mtd, floppy, 1373 pflash, virtio, none. 1374 1375 ``bus=bus,unit=unit`` 1376 These options define where is connected the drive by defining 1377 the bus number and the unit id. 1378 1379 ``index=index`` 1380 This option defines where the drive is connected by using an 1381 index in the list of available connectors of a given interface 1382 type. 1383 1384 ``media=media`` 1385 This option defines the type of the media: disk or cdrom. 1386 1387 ``snapshot=snapshot`` 1388 snapshot is "on" or "off" and controls snapshot mode for the 1389 given drive (see ``-snapshot``). 1390 1391 ``cache=cache`` 1392 cache is "none", "writeback", "unsafe", "directsync" or 1393 "writethrough" and controls how the host cache is used to access 1394 block data. This is a shortcut that sets the ``cache.direct`` 1395 and ``cache.no-flush`` options (as in ``-blockdev``), and 1396 additionally ``cache.writeback``, which provides a default for 1397 the ``write-cache`` option of block guest devices (as in 1398 ``-device``). The modes correspond to the following settings: 1399 1400 ============= =============== ============ ============== 1401 \ cache.writeback cache.direct cache.no-flush 1402 ============= =============== ============ ============== 1403 writeback on off off 1404 none on on off 1405 writethrough off off off 1406 directsync off on off 1407 unsafe on off on 1408 ============= =============== ============ ============== 1409 1410 The default mode is ``cache=writeback``. 1411 1412 ``aio=aio`` 1413 aio is "threads", "native", or "io_uring" and selects between pthread 1414 based disk I/O, native Linux AIO, or Linux io_uring API. 1415 1416 ``format=format`` 1417 Specify which disk format will be used rather than detecting the 1418 format. Can be used to specify format=raw to avoid interpreting 1419 an untrusted format header. 1420 1421 ``werror=action,rerror=action`` 1422 Specify which action to take on write and read errors. Valid 1423 actions are: "ignore" (ignore the error and try to continue), 1424 "stop" (pause QEMU), "report" (report the error to the guest), 1425 "enospc" (pause QEMU only if the host disk is full; report the 1426 error to the guest otherwise). The default setting is 1427 ``werror=enospc`` and ``rerror=report``. 1428 1429 ``copy-on-read=copy-on-read`` 1430 copy-on-read is "on" or "off" and enables whether to copy read 1431 backing file sectors into the image file. 1432 1433 ``bps=b,bps_rd=r,bps_wr=w`` 1434 Specify bandwidth throttling limits in bytes per second, either 1435 for all request types or for reads or writes only. Small values 1436 can lead to timeouts or hangs inside the guest. A safe minimum 1437 for disks is 2 MB/s. 1438 1439 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm`` 1440 Specify bursts in bytes per second, either for all request types 1441 or for reads or writes only. Bursts allow the guest I/O to spike 1442 above the limit temporarily. 1443 1444 ``iops=i,iops_rd=r,iops_wr=w`` 1445 Specify request rate limits in requests per second, either for 1446 all request types or for reads or writes only. 1447 1448 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm`` 1449 Specify bursts in requests per second, either for all request 1450 types or for reads or writes only. Bursts allow the guest I/O to 1451 spike above the limit temporarily. 1452 1453 ``iops_size=is`` 1454 Let every is bytes of a request count as a new request for iops 1455 throttling purposes. Use this option to prevent guests from 1456 circumventing iops limits by sending fewer but larger requests. 1457 1458 ``group=g`` 1459 Join a throttling quota group with given name g. All drives that 1460 are members of the same group are accounted for together. Use 1461 this option to prevent guests from circumventing throttling 1462 limits by using many small disks instead of a single larger 1463 disk. 1464 1465 By default, the ``cache.writeback=on`` mode is used. It will report 1466 data writes as completed as soon as the data is present in the host 1467 page cache. This is safe as long as your guest OS makes sure to 1468 correctly flush disk caches where needed. If your guest OS does not 1469 handle volatile disk write caches correctly and your host crashes or 1470 loses power, then the guest may experience data corruption. 1471 1472 For such guests, you should consider using ``cache.writeback=off``. 1473 This means that the host page cache will be used to read and write 1474 data, but write notification will be sent to the guest only after 1475 QEMU has made sure to flush each write to the disk. Be aware that 1476 this has a major impact on performance. 1477 1478 When using the ``-snapshot`` option, unsafe caching is always used. 1479 1480 Copy-on-read avoids accessing the same backing file sectors 1481 repeatedly and is useful when the backing file is over a slow 1482 network. By default copy-on-read is off. 1483 1484 Instead of ``-cdrom`` you can use: 1485 1486 .. parsed-literal:: 1487 1488 |qemu_system| -drive file=file,index=2,media=cdrom 1489 1490 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use: 1491 1492 .. parsed-literal:: 1493 1494 |qemu_system| -drive file=file,index=0,media=disk 1495 |qemu_system| -drive file=file,index=1,media=disk 1496 |qemu_system| -drive file=file,index=2,media=disk 1497 |qemu_system| -drive file=file,index=3,media=disk 1498 1499 You can open an image using pre-opened file descriptors from an fd 1500 set: 1501 1502 .. parsed-literal:: 1503 1504 |qemu_system| \\ 1505 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 1506 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 1507 -drive file=/dev/fdset/2,index=0,media=disk 1508 1509 You can connect a CDROM to the slave of ide0: 1510 1511 .. parsed-literal:: 1512 1513 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom 1514 1515 If you don't specify the "file=" argument, you define an empty 1516 drive: 1517 1518 .. parsed-literal:: 1519 1520 |qemu_system_x86| -drive if=ide,index=1,media=cdrom 1521 1522 Instead of ``-fda``, ``-fdb``, you can use: 1523 1524 .. parsed-literal:: 1525 1526 |qemu_system_x86| -drive file=file,index=0,if=floppy 1527 |qemu_system_x86| -drive file=file,index=1,if=floppy 1528 1529 By default, interface is "ide" and index is automatically 1530 incremented: 1531 1532 .. parsed-literal:: 1533 1534 |qemu_system_x86| -drive file=a -drive file=b" 1535 1536 is interpreted like: 1537 1538 .. parsed-literal:: 1539 1540 |qemu_system_x86| -hda a -hdb b 1541ERST 1542 1543DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1544 "-mtdblock file use 'file' as on-board Flash memory image\n", 1545 QEMU_ARCH_ALL) 1546SRST 1547``-mtdblock file`` 1548 Use file as on-board Flash memory image. 1549ERST 1550 1551DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1552 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1553SRST 1554``-sd file`` 1555 Use file as SecureDigital card image. 1556ERST 1557 1558DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1559 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1560SRST 1561``-pflash file`` 1562 Use file as a parallel flash image. 1563ERST 1564 1565DEF("snapshot", 0, QEMU_OPTION_snapshot, 1566 "-snapshot write to temporary files instead of disk image files\n", 1567 QEMU_ARCH_ALL) 1568SRST 1569``-snapshot`` 1570 Write to temporary files instead of disk image files. In this case, 1571 the raw disk image you use is not written back. You can however 1572 force the write back by pressing C-a s (see the :ref:`disk images` 1573 chapter in the System Emulation Users Guide). 1574ERST 1575 1576DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1577 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1578 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n" 1579 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1580 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1581 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1582 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1583 " [[,throttling.iops-size=is]]\n" 1584 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly=on]\n" 1585 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly=on]\n" 1586 "-fsdev synth,id=id\n", 1587 QEMU_ARCH_ALL) 1588 1589SRST 1590``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly=on][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]`` 1591 \ 1592``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly=on]`` 1593 \ 1594``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly=on]`` 1595 \ 1596``-fsdev synth,id=id[,readonly=on]`` 1597 Define a new file system device. Valid options are: 1598 1599 ``local`` 1600 Accesses to the filesystem are done by QEMU. 1601 1602 ``proxy`` 1603 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1604 1605 ``synth`` 1606 Synthetic filesystem, only used by QTests. 1607 1608 ``id=id`` 1609 Specifies identifier for this device. 1610 1611 ``path=path`` 1612 Specifies the export path for the file system device. Files 1613 under this path will be available to the 9p client on the guest. 1614 1615 ``security_model=security_model`` 1616 Specifies the security model to be used for this export path. 1617 Supported security models are "passthrough", "mapped-xattr", 1618 "mapped-file" and "none". In "passthrough" security model, files 1619 are stored using the same credentials as they are created on the 1620 guest. This requires QEMU to run as root. In "mapped-xattr" 1621 security model, some of the file attributes like uid, gid, mode 1622 bits and link target are stored as file attributes. For 1623 "mapped-file" these attributes are stored in the hidden 1624 .virtfs\_metadata directory. Directories exported by this 1625 security model cannot interact with other unix tools. "none" 1626 security model is same as passthrough except the sever won't 1627 report failures if it fails to set file attributes like 1628 ownership. Security model is mandatory only for local fsdriver. 1629 Other fsdrivers (like proxy) don't take security model as a 1630 parameter. 1631 1632 ``writeout=writeout`` 1633 This is an optional argument. The only supported value is 1634 "immediate". This means that host page cache will be used to 1635 read and write data but write notification will be sent to the 1636 guest only when the data has been reported as written by the 1637 storage subsystem. 1638 1639 ``readonly=on`` 1640 Enables exporting 9p share as a readonly mount for guests. By 1641 default read-write access is given. 1642 1643 ``socket=socket`` 1644 Enables proxy filesystem driver to use passed socket file for 1645 communicating with virtfs-proxy-helper(1). 1646 1647 ``sock_fd=sock_fd`` 1648 Enables proxy filesystem driver to use passed socket descriptor 1649 for communicating with virtfs-proxy-helper(1). Usually a helper 1650 like libvirt will create socketpair and pass one of the fds as 1651 sock\_fd. 1652 1653 ``fmode=fmode`` 1654 Specifies the default mode for newly created files on the host. 1655 Works only with security models "mapped-xattr" and 1656 "mapped-file". 1657 1658 ``dmode=dmode`` 1659 Specifies the default mode for newly created directories on the 1660 host. Works only with security models "mapped-xattr" and 1661 "mapped-file". 1662 1663 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w`` 1664 Specify bandwidth throttling limits in bytes per second, either 1665 for all request types or for reads or writes only. 1666 1667 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm`` 1668 Specify bursts in bytes per second, either for all request types 1669 or for reads or writes only. Bursts allow the guest I/O to spike 1670 above the limit temporarily. 1671 1672 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w`` 1673 Specify request rate limits in requests per second, either for 1674 all request types or for reads or writes only. 1675 1676 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm`` 1677 Specify bursts in requests per second, either for all request 1678 types or for reads or writes only. Bursts allow the guest I/O to 1679 spike above the limit temporarily. 1680 1681 ``throttling.iops-size=is`` 1682 Let every is bytes of a request count as a new request for iops 1683 throttling purposes. 1684 1685 -fsdev option is used along with -device driver "virtio-9p-...". 1686 1687``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag`` 1688 Options for virtio-9p-... driver are: 1689 1690 ``type`` 1691 Specifies the variant to be used. Supported values are "pci", 1692 "ccw" or "device", depending on the machine type. 1693 1694 ``fsdev=id`` 1695 Specifies the id value specified along with -fsdev option. 1696 1697 ``mount_tag=mount_tag`` 1698 Specifies the tag name to be used by the guest to mount this 1699 export point. 1700ERST 1701 1702DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1703 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1704 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1705 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly=on]\n" 1706 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly=on]\n" 1707 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n", 1708 QEMU_ARCH_ALL) 1709 1710SRST 1711``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly=on] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]`` 1712 \ 1713``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1714 \ 1715``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1716 \ 1717``-virtfs synth,mount_tag=mount_tag`` 1718 Define a new virtual filesystem device and expose it to the guest using 1719 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain 1720 directory on host is made directly accessible by guest as a pass-through 1721 file system by using the 9P network protocol for communication between 1722 host and guests, if desired even accessible, shared by several guests 1723 simultaniously. 1724 1725 Note that ``-virtfs`` is actually just a convenience shortcut for its 1726 generalized form ``-fsdev -device virtio-9p-pci``. 1727 1728 The general form of pass-through file system options are: 1729 1730 ``local`` 1731 Accesses to the filesystem are done by QEMU. 1732 1733 ``proxy`` 1734 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1735 1736 ``synth`` 1737 Synthetic filesystem, only used by QTests. 1738 1739 ``id=id`` 1740 Specifies identifier for the filesystem device 1741 1742 ``path=path`` 1743 Specifies the export path for the file system device. Files 1744 under this path will be available to the 9p client on the guest. 1745 1746 ``security_model=security_model`` 1747 Specifies the security model to be used for this export path. 1748 Supported security models are "passthrough", "mapped-xattr", 1749 "mapped-file" and "none". In "passthrough" security model, files 1750 are stored using the same credentials as they are created on the 1751 guest. This requires QEMU to run as root. In "mapped-xattr" 1752 security model, some of the file attributes like uid, gid, mode 1753 bits and link target are stored as file attributes. For 1754 "mapped-file" these attributes are stored in the hidden 1755 .virtfs\_metadata directory. Directories exported by this 1756 security model cannot interact with other unix tools. "none" 1757 security model is same as passthrough except the sever won't 1758 report failures if it fails to set file attributes like 1759 ownership. Security model is mandatory only for local fsdriver. 1760 Other fsdrivers (like proxy) don't take security model as a 1761 parameter. 1762 1763 ``writeout=writeout`` 1764 This is an optional argument. The only supported value is 1765 "immediate". This means that host page cache will be used to 1766 read and write data but write notification will be sent to the 1767 guest only when the data has been reported as written by the 1768 storage subsystem. 1769 1770 ``readonly=on`` 1771 Enables exporting 9p share as a readonly mount for guests. By 1772 default read-write access is given. 1773 1774 ``socket=socket`` 1775 Enables proxy filesystem driver to use passed socket file for 1776 communicating with virtfs-proxy-helper(1). Usually a helper like 1777 libvirt will create socketpair and pass one of the fds as 1778 sock\_fd. 1779 1780 ``sock_fd`` 1781 Enables proxy filesystem driver to use passed 'sock\_fd' as the 1782 socket descriptor for interfacing with virtfs-proxy-helper(1). 1783 1784 ``fmode=fmode`` 1785 Specifies the default mode for newly created files on the host. 1786 Works only with security models "mapped-xattr" and 1787 "mapped-file". 1788 1789 ``dmode=dmode`` 1790 Specifies the default mode for newly created directories on the 1791 host. Works only with security models "mapped-xattr" and 1792 "mapped-file". 1793 1794 ``mount_tag=mount_tag`` 1795 Specifies the tag name to be used by the guest to mount this 1796 export point. 1797 1798 ``multidevs=multidevs`` 1799 Specifies how to deal with multiple devices being shared with a 1800 9p export. Supported behaviours are either "remap", "forbid" or 1801 "warn". The latter is the default behaviour on which virtfs 9p 1802 expects only one device to be shared with the same export, and 1803 if more than one device is shared and accessed via the same 9p 1804 export then only a warning message is logged (once) by qemu on 1805 host side. In order to avoid file ID collisions on guest you 1806 should either create a separate virtfs export for each device to 1807 be shared with guests (recommended way) or you might use "remap" 1808 instead which allows you to share multiple devices with only one 1809 export instead, which is achieved by remapping the original 1810 inode numbers from host to guest in a way that would prevent 1811 such collisions. Remapping inodes in such use cases is required 1812 because the original device IDs from host are never passed and 1813 exposed on guest. Instead all files of an export shared with 1814 virtfs always share the same device id on guest. So two files 1815 with identical inode numbers but from actually different devices 1816 on host would otherwise cause a file ID collision and hence 1817 potential misbehaviours on guest. "forbid" on the other hand 1818 assumes like "warn" that only one device is shared by the same 1819 export, however it will not only log a warning message but also 1820 deny access to additional devices on guest. Note though that 1821 "forbid" does currently not block all possible file access 1822 operations (e.g. readdir() would still return entries from other 1823 devices). 1824ERST 1825 1826DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1827 "-iscsi [user=user][,password=password]\n" 1828 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1829 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1830 " [,timeout=timeout]\n" 1831 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1832 1833SRST 1834``-iscsi`` 1835 Configure iSCSI session parameters. 1836ERST 1837 1838DEFHEADING() 1839 1840DEFHEADING(USB convenience options:) 1841 1842DEF("usb", 0, QEMU_OPTION_usb, 1843 "-usb enable on-board USB host controller (if not enabled by default)\n", 1844 QEMU_ARCH_ALL) 1845SRST 1846``-usb`` 1847 Enable USB emulation on machine types with an on-board USB host 1848 controller (if not enabled by default). Note that on-board USB host 1849 controllers may not support USB 3.0. In this case 1850 ``-device qemu-xhci`` can be used instead on machines with PCI. 1851ERST 1852 1853DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1854 "-usbdevice name add the host or guest USB device 'name'\n", 1855 QEMU_ARCH_ALL) 1856SRST 1857``-usbdevice devname`` 1858 Add the USB device devname, and enable an on-board USB controller 1859 if possible and necessary (just like it can be done via 1860 ``-machine usb=on``). Note that this option is mainly intended for 1861 the user's convenience only. More fine-grained control can be 1862 achieved by selecting a USB host controller (if necessary) and the 1863 desired USB device via the ``-device`` option instead. For example, 1864 instead of using ``-usbdevice mouse`` it is possible to use 1865 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse 1866 to a USB 3.0 controller instead (at least on machines that support 1867 PCI and do not have an USB controller enabled by default yet). 1868 For more details, see the chapter about 1869 :ref:`Connecting USB devices` in the System Emulation Users Guide. 1870 Possible devices for devname are: 1871 1872 ``braille`` 1873 Braille device. This will use BrlAPI to display the braille 1874 output on a real or fake device (i.e. it also creates a 1875 corresponding ``braille`` chardev automatically beside the 1876 ``usb-braille`` USB device). 1877 1878 ``keyboard`` 1879 Standard USB keyboard. Will override the PS/2 keyboard (if present). 1880 1881 ``mouse`` 1882 Virtual Mouse. This will override the PS/2 mouse emulation when 1883 activated. 1884 1885 ``tablet`` 1886 Pointer device that uses absolute coordinates (like a 1887 touchscreen). This means QEMU is able to report the mouse 1888 position without having to grab the mouse. Also overrides the 1889 PS/2 mouse emulation when activated. 1890 1891 ``wacom-tablet`` 1892 Wacom PenPartner USB tablet. 1893 1894 1895ERST 1896 1897DEFHEADING() 1898 1899DEFHEADING(Display options:) 1900 1901DEF("display", HAS_ARG, QEMU_OPTION_display, 1902#if defined(CONFIG_SPICE) 1903 "-display spice-app[,gl=on|off]\n" 1904#endif 1905#if defined(CONFIG_SDL) 1906 "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off][,gl=on|core|es|off]\n" 1907 " [,grab-mod=<mod>][,show-cursor=on|off][,window-close=on|off]\n" 1908#endif 1909#if defined(CONFIG_GTK) 1910 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n" 1911 " [,show-cursor=on|off][,window-close=on|off]\n" 1912#endif 1913#if defined(CONFIG_VNC) 1914 "-display vnc=<display>[,<optargs>]\n" 1915#endif 1916#if defined(CONFIG_CURSES) 1917 "-display curses[,charset=<encoding>]\n" 1918#endif 1919#if defined(CONFIG_OPENGL) 1920 "-display egl-headless[,rendernode=<file>]\n" 1921#endif 1922#if defined(CONFIG_DBUS_DISPLAY) 1923 "-display dbus[,addr=<dbusaddr>]\n" 1924 " [,gl=on|core|es|off][,rendernode=<file>]\n" 1925#endif 1926 "-display none\n" 1927 " select display backend type\n" 1928 " The default display is equivalent to\n " 1929#if defined(CONFIG_GTK) 1930 "\"-display gtk\"\n" 1931#elif defined(CONFIG_SDL) 1932 "\"-display sdl\"\n" 1933#elif defined(CONFIG_COCOA) 1934 "\"-display cocoa\"\n" 1935#elif defined(CONFIG_VNC) 1936 "\"-vnc localhost:0,to=99,id=default\"\n" 1937#else 1938 "\"-display none\"\n" 1939#endif 1940 , QEMU_ARCH_ALL) 1941SRST 1942``-display type`` 1943 Select type of display to use. This option is a replacement for the 1944 old style -sdl/-curses/... options. Use ``-display help`` to list 1945 the available display types. Valid values for type are 1946 1947 ``spice-app[,gl=on|off]`` 1948 Start QEMU as a Spice server and launch the default Spice client 1949 application. The Spice server will redirect the serial consoles 1950 and QEMU monitors. (Since 4.0) 1951 1952 ``dbus`` 1953 Export the display over D-Bus interfaces. (Since 7.0) 1954 1955 The connection is registered with the "org.qemu" name (and queued when 1956 already owned). 1957 1958 ``addr=<dbusaddr>`` : D-Bus bus address to connect to. 1959 1960 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``. 1961 1962 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface 1963 will share framebuffers with DMABUF file descriptors). 1964 1965 ``sdl`` 1966 Display video output via SDL (usually in a separate graphics 1967 window; see the SDL documentation for other possibilities). 1968 Valid parameters are: 1969 1970 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling 1971 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be 1972 either ``lshift-lctrl-lalt`` or ``rctrl``. 1973 1974 ``alt_grab=on|off`` : Use Control+Alt+Shift-g to toggle mouse grabbing. 1975 This parameter is deprecated - use ``grab-mod`` instead. 1976 1977 ``ctrl_grab=on|off`` : Use Right-Control-g to toggle mouse grabbing. 1978 This parameter is deprecated - use ``grab-mod`` instead. 1979 1980 ``gl=on|off|core|es`` : Use OpenGL for displaying 1981 1982 ``show-cursor=on|off`` : Force showing the mouse cursor 1983 1984 ``window-close=on|off`` : Allow to quit qemu with window close button 1985 1986 ``gtk`` 1987 Display video output in a GTK window. This interface provides 1988 drop-down menus and other UI elements to configure and control 1989 the VM during runtime. Valid parameters are: 1990 1991 ``full-screen=on|off`` : Start in fullscreen mode 1992 1993 ``gl=on|off`` : Use OpenGL for displaying 1994 1995 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover 1996 1997 ``show-cursor=on|off`` : Force showing the mouse cursor 1998 1999 ``window-close=on|off`` : Allow to quit qemu with window close button 2000 2001 ``curses[,charset=<encoding>]`` 2002 Display video output via curses. For graphics device models 2003 which support a text mode, QEMU can display this output using a 2004 curses/ncurses interface. Nothing is displayed when the graphics 2005 device is in graphical mode or if the graphics device does not 2006 support a text mode. Generally only the VGA device models 2007 support text mode. The font charset used by the guest can be 2008 specified with the ``charset`` option, for example 2009 ``charset=CP850`` for IBM CP850 encoding. The default is 2010 ``CP437``. 2011 2012 ``egl-headless[,rendernode=<file>]`` 2013 Offload all OpenGL operations to a local DRI device. For any 2014 graphical display, this display needs to be paired with either 2015 VNC or SPICE displays. 2016 2017 ``vnc=<display>`` 2018 Start a VNC server on display <display> 2019 2020 ``none`` 2021 Do not display video output. The guest will still see an 2022 emulated graphics card, but its output will not be displayed to 2023 the QEMU user. This option differs from the -nographic option in 2024 that it only affects what is done with video output; -nographic 2025 also changes the destination of the serial and parallel port 2026 data. 2027ERST 2028 2029DEF("nographic", 0, QEMU_OPTION_nographic, 2030 "-nographic disable graphical output and redirect serial I/Os to console\n", 2031 QEMU_ARCH_ALL) 2032SRST 2033``-nographic`` 2034 Normally, if QEMU is compiled with graphical window support, it 2035 displays output such as guest graphics, guest console, and the QEMU 2036 monitor in a window. With this option, you can totally disable 2037 graphical output so that QEMU is a simple command line application. 2038 The emulated serial port is redirected on the console and muxed with 2039 the monitor (unless redirected elsewhere explicitly). Therefore, you 2040 can still use QEMU to debug a Linux kernel with a serial console. 2041 Use C-a h for help on switching between the console and monitor. 2042ERST 2043 2044DEF("curses", 0, QEMU_OPTION_curses, 2045 "-curses shorthand for -display curses\n", 2046 QEMU_ARCH_ALL) 2047SRST 2048``-curses`` 2049 Normally, if QEMU is compiled with graphical window support, it 2050 displays output such as guest graphics, guest console, and the QEMU 2051 monitor in a window. With this option, QEMU can display the VGA 2052 output when in text mode using a curses/ncurses interface. Nothing 2053 is displayed in graphical mode. 2054ERST 2055 2056DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 2057 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 2058 QEMU_ARCH_ALL) 2059SRST 2060``-alt-grab`` 2061 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that 2062 this also affects the special keys (for fullscreen, monitor-mode 2063 switching, etc). This option is deprecated - please use 2064 ``-display sdl,grab-mod=lshift-lctrl-lalt`` instead. 2065ERST 2066 2067DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 2068 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 2069 QEMU_ARCH_ALL) 2070SRST 2071``-ctrl-grab`` 2072 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this 2073 also affects the special keys (for fullscreen, monitor-mode 2074 switching, etc). This option is deprecated - please use 2075 ``-display sdl,grab-mod=rctrl`` instead. 2076ERST 2077 2078DEF("sdl", 0, QEMU_OPTION_sdl, 2079 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 2080SRST 2081``-sdl`` 2082 Enable SDL. 2083ERST 2084 2085DEF("spice", HAS_ARG, QEMU_OPTION_spice, 2086 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 2087 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 2088 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 2089 " [,x509-dh-key-file=<file>][,addr=addr]\n" 2090 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n" 2091 " [,tls-ciphers=<list>]\n" 2092 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 2093 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 2094 " [,sasl=on|off][,disable-ticketing=on|off]\n" 2095 " [,password=<string>][,password-secret=<secret-id>]\n" 2096 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 2097 " [,jpeg-wan-compression=[auto|never|always]]\n" 2098 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 2099 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n" 2100 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n" 2101 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 2102 " [,gl=[on|off]][,rendernode=<file>]\n" 2103 " enable spice\n" 2104 " at least one of {port, tls-port} is mandatory\n", 2105 QEMU_ARCH_ALL) 2106SRST 2107``-spice option[,option[,...]]`` 2108 Enable the spice remote desktop protocol. Valid options are 2109 2110 ``port=<nr>`` 2111 Set the TCP port spice is listening on for plaintext channels. 2112 2113 ``addr=<addr>`` 2114 Set the IP address spice is listening on. Default is any 2115 address. 2116 2117 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off`` 2118 Force using the specified IP version. 2119 2120 ``password=<string>`` 2121 Set the password you need to authenticate. 2122 2123 This option is deprecated and insecure because it leaves the 2124 password visible in the process listing. Use ``password-secret`` 2125 instead. 2126 2127 ``password-secret=<secret-id>`` 2128 Set the ID of the ``secret`` object containing the password 2129 you need to authenticate. 2130 2131 ``sasl=on|off`` 2132 Require that the client use SASL to authenticate with the spice. 2133 The exact choice of authentication method used is controlled 2134 from the system / user's SASL configuration file for the 'qemu' 2135 service. This is typically found in /etc/sasl2/qemu.conf. If 2136 running QEMU as an unprivileged user, an environment variable 2137 SASL\_CONF\_PATH can be used to make it search alternate 2138 locations for the service config. While some SASL auth methods 2139 can also provide data encryption (eg GSSAPI), it is recommended 2140 that SASL always be combined with the 'tls' and 'x509' settings 2141 to enable use of SSL and server certificates. This ensures a 2142 data encryption preventing compromise of authentication 2143 credentials. 2144 2145 ``disable-ticketing=on|off`` 2146 Allow client connects without authentication. 2147 2148 ``disable-copy-paste=on|off`` 2149 Disable copy paste between the client and the guest. 2150 2151 ``disable-agent-file-xfer=on|off`` 2152 Disable spice-vdagent based file-xfer between the client and the 2153 guest. 2154 2155 ``tls-port=<nr>`` 2156 Set the TCP port spice is listening on for encrypted channels. 2157 2158 ``x509-dir=<dir>`` 2159 Set the x509 file directory. Expects same filenames as -vnc 2160 $display,x509=$dir 2161 2162 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>`` 2163 The x509 file names can also be configured individually. 2164 2165 ``tls-ciphers=<list>`` 2166 Specify which ciphers to use. 2167 2168 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]`` 2169 Force specific channel to be used with or without TLS 2170 encryption. The options can be specified multiple times to 2171 configure multiple channels. The special name "default" can be 2172 used to set the default mode. For channels which are not 2173 explicitly forced into one mode the spice client is allowed to 2174 pick tls/plaintext as he pleases. 2175 2176 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]`` 2177 Configure image compression (lossless). Default is auto\_glz. 2178 2179 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]`` 2180 Configure wan image compression (lossy for slow links). Default 2181 is auto. 2182 2183 ``streaming-video=[off|all|filter]`` 2184 Configure video stream detection. Default is off. 2185 2186 ``agent-mouse=[on|off]`` 2187 Enable/disable passing mouse events via vdagent. Default is on. 2188 2189 ``playback-compression=[on|off]`` 2190 Enable/disable audio stream compression (using celt 0.5.1). 2191 Default is on. 2192 2193 ``seamless-migration=[on|off]`` 2194 Enable/disable spice seamless migration. Default is off. 2195 2196 ``gl=[on|off]`` 2197 Enable/disable OpenGL context. Default is off. 2198 2199 ``rendernode=<file>`` 2200 DRM render node for OpenGL rendering. If not specified, it will 2201 pick the first available. (Since 2.9) 2202ERST 2203 2204DEF("portrait", 0, QEMU_OPTION_portrait, 2205 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 2206 QEMU_ARCH_ALL) 2207SRST 2208``-portrait`` 2209 Rotate graphical output 90 deg left (only PXA LCD). 2210ERST 2211 2212DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 2213 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 2214 QEMU_ARCH_ALL) 2215SRST 2216``-rotate deg`` 2217 Rotate graphical output some deg left (only PXA LCD). 2218ERST 2219 2220DEF("vga", HAS_ARG, QEMU_OPTION_vga, 2221 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 2222 " select video card type\n", QEMU_ARCH_ALL) 2223SRST 2224``-vga type`` 2225 Select type of VGA card to emulate. Valid values for type are 2226 2227 ``cirrus`` 2228 Cirrus Logic GD5446 Video card. All Windows versions starting 2229 from Windows 95 should recognize and use this graphic card. For 2230 optimal performances, use 16 bit color depth in the guest and 2231 the host OS. (This card was the default before QEMU 2.2) 2232 2233 ``std`` 2234 Standard VGA card with Bochs VBE extensions. If your guest OS 2235 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if 2236 you want to use high resolution modes (>= 1280x1024x16) then you 2237 should use this option. (This card is the default since QEMU 2238 2.2) 2239 2240 ``vmware`` 2241 VMWare SVGA-II compatible adapter. Use it if you have 2242 sufficiently recent XFree86/XOrg server or Windows guest with a 2243 driver for this card. 2244 2245 ``qxl`` 2246 QXL paravirtual graphic card. It is VGA compatible (including 2247 VESA 2.0 VBE support). Works best with qxl guest drivers 2248 installed though. Recommended choice when using the spice 2249 protocol. 2250 2251 ``tcx`` 2252 (sun4m only) Sun TCX framebuffer. This is the default 2253 framebuffer for sun4m machines and offers both 8-bit and 24-bit 2254 colour depths at a fixed resolution of 1024x768. 2255 2256 ``cg3`` 2257 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit 2258 framebuffer for sun4m machines available in both 1024x768 2259 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people 2260 wishing to run older Solaris versions. 2261 2262 ``virtio`` 2263 Virtio VGA card. 2264 2265 ``none`` 2266 Disable VGA card. 2267ERST 2268 2269DEF("full-screen", 0, QEMU_OPTION_full_screen, 2270 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 2271SRST 2272``-full-screen`` 2273 Start in full screen. 2274ERST 2275 2276DEF("g", HAS_ARG, QEMU_OPTION_g , 2277 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 2278 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 2279SRST 2280``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]`` 2281 Set the initial graphical resolution and depth (PPC, SPARC only). 2282 2283 For PPC the default is 800x600x32. 2284 2285 For SPARC with the TCX graphics device, the default is 1024x768x8 2286 with the option of 1024x768x24. For cgthree, the default is 2287 1024x768x8 with the option of 1152x900x8 for people who wish to use 2288 OBP. 2289ERST 2290 2291DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 2292 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 2293SRST 2294``-vnc display[,option[,option[,...]]]`` 2295 Normally, if QEMU is compiled with graphical window support, it 2296 displays output such as guest graphics, guest console, and the QEMU 2297 monitor in a window. With this option, you can have QEMU listen on 2298 VNC display display and redirect the VGA display over the VNC 2299 session. It is very useful to enable the usb tablet device when 2300 using this option (option ``-device usb-tablet``). When using the 2301 VNC display, you must use the ``-k`` parameter to set the keyboard 2302 layout if you are not using en-us. Valid syntax for the display is 2303 2304 ``to=L`` 2305 With this option, QEMU will try next available VNC displays, 2306 until the number L, if the origianlly defined "-vnc display" is 2307 not available, e.g. port 5900+display is already used by another 2308 application. By default, to=0. 2309 2310 ``host:d`` 2311 TCP connections will only be allowed from host on display d. By 2312 convention the TCP port is 5900+d. Optionally, host can be 2313 omitted in which case the server will accept connections from 2314 any host. 2315 2316 ``unix:path`` 2317 Connections will be allowed over UNIX domain sockets where path 2318 is the location of a unix socket to listen for connections on. 2319 2320 ``none`` 2321 VNC is initialized but not started. The monitor ``change`` 2322 command can be used to later start the VNC server. 2323 2324 Following the display value there may be one or more option flags 2325 separated by commas. Valid options are 2326 2327 ``reverse=on|off`` 2328 Connect to a listening VNC client via a "reverse" connection. 2329 The client is specified by the display. For reverse network 2330 connections (host:d,``reverse``), the d argument is a TCP port 2331 number, not a display number. 2332 2333 ``websocket=on|off`` 2334 Opens an additional TCP listening port dedicated to VNC 2335 Websocket connections. If a bare websocket option is given, the 2336 Websocket port is 5700+display. An alternative port can be 2337 specified with the syntax ``websocket``\ =port. 2338 2339 If host is specified connections will only be allowed from this 2340 host. It is possible to control the websocket listen address 2341 independently, using the syntax ``websocket``\ =host:port. 2342 2343 If no TLS credentials are provided, the websocket connection 2344 runs in unencrypted mode. If TLS credentials are provided, the 2345 websocket connection requires encrypted client connections. 2346 2347 ``password=on|off`` 2348 Require that password based authentication is used for client 2349 connections. 2350 2351 The password must be set separately using the ``set_password`` 2352 command in the :ref:`QEMU monitor`. The 2353 syntax to change your password is: 2354 ``set_password <protocol> <password>`` where <protocol> could be 2355 either "vnc" or "spice". 2356 2357 If you would like to change <protocol> password expiration, you 2358 should use ``expire_password <protocol> <expiration-time>`` 2359 where expiration time could be one of the following options: 2360 now, never, +seconds or UNIX time of expiration, e.g. +60 to 2361 make password expire in 60 seconds, or 1335196800 to make 2362 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for 2363 this date and time). 2364 2365 You can also use keywords "now" or "never" for the expiration 2366 time to allow <protocol> password to expire immediately or never 2367 expire. 2368 2369 ``password-secret=<secret-id>`` 2370 Require that password based authentication is used for client 2371 connections, using the password provided by the ``secret`` 2372 object identified by ``secret-id``. 2373 2374 ``tls-creds=ID`` 2375 Provides the ID of a set of TLS credentials to use to secure the 2376 VNC server. They will apply to both the normal VNC server socket 2377 and the websocket socket (if enabled). Setting TLS credentials 2378 will cause the VNC server socket to enable the VeNCrypt auth 2379 mechanism. The credentials should have been previously created 2380 using the ``-object tls-creds`` argument. 2381 2382 ``tls-authz=ID`` 2383 Provides the ID of the QAuthZ authorization object against which 2384 the client's x509 distinguished name will validated. This object 2385 is only resolved at time of use, so can be deleted and recreated 2386 on the fly while the VNC server is active. If missing, it will 2387 default to denying access. 2388 2389 ``sasl=on|off`` 2390 Require that the client use SASL to authenticate with the VNC 2391 server. The exact choice of authentication method used is 2392 controlled from the system / user's SASL configuration file for 2393 the 'qemu' service. This is typically found in 2394 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, 2395 an environment variable SASL\_CONF\_PATH can be used to make it 2396 search alternate locations for the service config. While some 2397 SASL auth methods can also provide data encryption (eg GSSAPI), 2398 it is recommended that SASL always be combined with the 'tls' 2399 and 'x509' settings to enable use of SSL and server 2400 certificates. This ensures a data encryption preventing 2401 compromise of authentication credentials. See the 2402 :ref:`VNC security` section in the System Emulation Users Guide 2403 for details on using SASL authentication. 2404 2405 ``sasl-authz=ID`` 2406 Provides the ID of the QAuthZ authorization object against which 2407 the client's SASL username will validated. This object is only 2408 resolved at time of use, so can be deleted and recreated on the 2409 fly while the VNC server is active. If missing, it will default 2410 to denying access. 2411 2412 ``acl=on|off`` 2413 Legacy method for enabling authorization of clients against the 2414 x509 distinguished name and SASL username. It results in the 2415 creation of two ``authz-list`` objects with IDs of 2416 ``vnc.username`` and ``vnc.x509dname``. The rules for these 2417 objects must be configured with the HMP ACL commands. 2418 2419 This option is deprecated and should no longer be used. The new 2420 ``sasl-authz`` and ``tls-authz`` options are a replacement. 2421 2422 ``lossy=on|off`` 2423 Enable lossy compression methods (gradient, JPEG, ...). If this 2424 option is set, VNC client may receive lossy framebuffer updates 2425 depending on its encoding settings. Enabling this option can 2426 save a lot of bandwidth at the expense of quality. 2427 2428 ``non-adaptive=on|off`` 2429 Disable adaptive encodings. Adaptive encodings are enabled by 2430 default. An adaptive encoding will try to detect frequently 2431 updated screen regions, and send updates in these regions using 2432 a lossy encoding (like JPEG). This can be really helpful to save 2433 bandwidth when playing videos. Disabling adaptive encodings 2434 restores the original static behavior of encodings like Tight. 2435 2436 ``share=[allow-exclusive|force-shared|ignore]`` 2437 Set display sharing policy. 'allow-exclusive' allows clients to 2438 ask for exclusive access. As suggested by the rfb spec this is 2439 implemented by dropping other connections. Connecting multiple 2440 clients in parallel requires all clients asking for a shared 2441 session (vncviewer: -shared switch). This is the default. 2442 'force-shared' disables exclusive client access. Useful for 2443 shared desktop sessions, where you don't want someone forgetting 2444 specify -shared disconnect everybody else. 'ignore' completely 2445 ignores the shared flag and allows everybody connect 2446 unconditionally. Doesn't conform to the rfb spec but is 2447 traditional QEMU behavior. 2448 2449 ``key-delay-ms`` 2450 Set keyboard delay, for key down and key up events, in 2451 milliseconds. Default is 10. Keyboards are low-bandwidth 2452 devices, so this slowdown can help the device and guest to keep 2453 up and not lose events in case events are arriving in bulk. 2454 Possible causes for the latter are flaky network connections, or 2455 scripts for automated testing. 2456 2457 ``audiodev=audiodev`` 2458 Use the specified audiodev when the VNC client requests audio 2459 transmission. When not using an -audiodev argument, this option 2460 must be omitted, otherwise is must be present and specify a 2461 valid audiodev. 2462 2463 ``power-control=on|off`` 2464 Permit the remote client to issue shutdown, reboot or reset power 2465 control requests. 2466ERST 2467 2468ARCHHEADING(, QEMU_ARCH_I386) 2469 2470ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2471 2472DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2473 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2474 QEMU_ARCH_I386) 2475SRST 2476``-win2k-hack`` 2477 Use it when installing Windows 2000 to avoid a disk full bug. After 2478 Windows 2000 is installed, you no longer need this option (this 2479 option slows down the IDE transfers). 2480ERST 2481 2482DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2483 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2484 QEMU_ARCH_I386) 2485SRST 2486``-no-fd-bootchk`` 2487 Disable boot signature checking for floppy disks in BIOS. May be 2488 needed to boot from old floppy disks. 2489ERST 2490 2491DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2492 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2493SRST 2494``-no-acpi`` 2495 Disable ACPI (Advanced Configuration and Power Interface) support. 2496 Use it if your guest OS complains about ACPI problems (PC target 2497 machine only). 2498ERST 2499 2500DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2501 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2502SRST 2503``-no-hpet`` 2504 Disable HPET support. 2505ERST 2506 2507DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2508 "-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" 2509 " ACPI table description\n", QEMU_ARCH_I386) 2510SRST 2511``-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]...]`` 2512 Add ACPI table with specified header fields and context from 2513 specified files. For file=, take whole ACPI table from the specified 2514 files, including all ACPI headers (possible overridden by other 2515 options). For data=, only data portion of the table is used, all 2516 header information is specified in the command line. If a SLIC table 2517 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id 2518 fields will override the same in the RSDT and the FADT (a.k.a. 2519 FACP), in order to ensure the field matches required by the 2520 Microsoft SLIC spec and the ACPI spec. 2521ERST 2522 2523DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2524 "-smbios file=binary\n" 2525 " load SMBIOS entry from binary file\n" 2526 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2527 " [,uefi=on|off]\n" 2528 " specify SMBIOS type 0 fields\n" 2529 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2530 " [,uuid=uuid][,sku=str][,family=str]\n" 2531 " specify SMBIOS type 1 fields\n" 2532 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2533 " [,asset=str][,location=str]\n" 2534 " specify SMBIOS type 2 fields\n" 2535 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2536 " [,sku=str]\n" 2537 " specify SMBIOS type 3 fields\n" 2538 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2539 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n" 2540 " specify SMBIOS type 4 fields\n" 2541 "-smbios type=11[,value=str][,path=filename]\n" 2542 " specify SMBIOS type 11 fields\n" 2543 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2544 " [,asset=str][,part=str][,speed=%d]\n" 2545 " specify SMBIOS type 17 fields\n" 2546 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n" 2547 " specify SMBIOS type 41 fields\n", 2548 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2549SRST 2550``-smbios file=binary`` 2551 Load SMBIOS entry from binary file. 2552 2553``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]`` 2554 Specify SMBIOS type 0 fields 2555 2556``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]`` 2557 Specify SMBIOS type 1 fields 2558 2559``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]`` 2560 Specify SMBIOS type 2 fields 2561 2562``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]`` 2563 Specify SMBIOS type 3 fields 2564 2565``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str]`` 2566 Specify SMBIOS type 4 fields 2567 2568``-smbios type=11[,value=str][,path=filename]`` 2569 Specify SMBIOS type 11 fields 2570 2571 This argument can be repeated multiple times, and values are added in the order they are parsed. 2572 Applications intending to use OEM strings data are encouraged to use their application name as 2573 a prefix for the value string. This facilitates passing information for multiple applications 2574 concurrently. 2575 2576 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax 2577 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes. 2578 2579 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to 2580 the SMBIOS table in the order in which they appear. 2581 2582 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535 2583 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the 2584 guest. Instead it should be used as a indicator to inform the guest where to locate the real 2585 data set, for example, by specifying the serial ID of a block device. 2586 2587 An example passing three strings is 2588 2589 .. parsed-literal:: 2590 2591 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\ 2592 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\ 2593 path=/some/file/with/oemstringsdata.txt 2594 2595 In the guest OS this is visible with the ``dmidecode`` command 2596 2597 .. parsed-literal:: 2598 2599 $ dmidecode -t 11 2600 Handle 0x0E00, DMI type 11, 5 bytes 2601 OEM Strings 2602 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/ 2603 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os 2604 String 3: myapp:some extra data 2605 2606 2607``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]`` 2608 Specify SMBIOS type 17 fields 2609 2610``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]`` 2611 Specify SMBIOS type 41 fields 2612 2613 This argument can be repeated multiple times. Its main use is to allow network interfaces be created 2614 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface 2615 position on the PCI bus. 2616 2617 Here is an example of use: 2618 2619 .. parsed-literal:: 2620 2621 -netdev user,id=internet \\ 2622 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\ 2623 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev 2624 2625 In the guest OS, the device should then appear as ``eno1``: 2626 2627 ..parsed-literal:: 2628 2629 $ ip -brief l 2630 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP> 2631 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP> 2632 2633 Currently, the PCI device has to be attached to the root bus. 2634 2635ERST 2636 2637DEFHEADING() 2638 2639DEFHEADING(Network options:) 2640 2641DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2642#ifdef CONFIG_SLIRP 2643 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n" 2644 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2645 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2646 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2647 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2648#ifndef _WIN32 2649 "[,smb=dir[,smbserver=addr]]\n" 2650#endif 2651 " configure a user mode network backend with ID 'str',\n" 2652 " its DHCP server and optional services\n" 2653#endif 2654#ifdef _WIN32 2655 "-netdev tap,id=str,ifname=name\n" 2656 " configure a host TAP network backend with ID 'str'\n" 2657#else 2658 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2659 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2660 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2661 " [,poll-us=n]\n" 2662 " configure a host TAP network backend with ID 'str'\n" 2663 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2664 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2665 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2666 " to deconfigure it\n" 2667 " use '[down]script=no' to disable script execution\n" 2668 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2669 " configure it\n" 2670 " use 'fd=h' to connect to an already opened TAP interface\n" 2671 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2672 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2673 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2674 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2675 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2676 " use vhost=on to enable experimental in kernel accelerator\n" 2677 " (only has effect for virtio guests which use MSIX)\n" 2678 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2679 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2680 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2681 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2682 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n" 2683 " spent on busy polling for vhost net\n" 2684 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2685 " configure a host TAP network backend with ID 'str' that is\n" 2686 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2687 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2688#endif 2689#ifdef __linux__ 2690 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2691 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n" 2692 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n" 2693 " [,rxcookie=rxcookie][,offset=offset]\n" 2694 " configure a network backend with ID 'str' connected to\n" 2695 " an Ethernet over L2TPv3 pseudowire.\n" 2696 " Linux kernel 3.3+ as well as most routers can talk\n" 2697 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2698 " VM to a router and even VM to Host. It is a nearly-universal\n" 2699 " standard (RFC3931). Note - this implementation uses static\n" 2700 " pre-configured tunnels (same as the Linux kernel).\n" 2701 " use 'src=' to specify source address\n" 2702 " use 'dst=' to specify destination address\n" 2703 " use 'udp=on' to specify udp encapsulation\n" 2704 " use 'srcport=' to specify source udp port\n" 2705 " use 'dstport=' to specify destination udp port\n" 2706 " use 'ipv6=on' to force v6\n" 2707 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2708 " well as a weak security measure\n" 2709 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2710 " use 'txcookie=0x012345678' to specify a txcookie\n" 2711 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2712 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2713 " use 'pincounter=on' to work around broken counter handling in peer\n" 2714 " use 'offset=X' to add an extra offset between header and data\n" 2715#endif 2716 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2717 " configure a network backend to connect to another network\n" 2718 " using a socket connection\n" 2719 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2720 " configure a network backend to connect to a multicast maddr and port\n" 2721 " use 'localaddr=addr' to specify the host address to send packets from\n" 2722 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2723 " configure a network backend to connect to another network\n" 2724 " using an UDP tunnel\n" 2725#ifdef CONFIG_VDE 2726 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2727 " configure a network backend to connect to port 'n' of a vde switch\n" 2728 " running on host and listening for incoming connections on 'socketpath'.\n" 2729 " Use group 'groupname' and mode 'octalmode' to change default\n" 2730 " ownership and permissions for communication port.\n" 2731#endif 2732#ifdef CONFIG_NETMAP 2733 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2734 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2735 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2736 " netmap device, defaults to '/dev/netmap')\n" 2737#endif 2738#ifdef CONFIG_POSIX 2739 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2740 " configure a vhost-user network, backed by a chardev 'dev'\n" 2741#endif 2742#ifdef __linux__ 2743 "-netdev vhost-vdpa,id=str,vhostdev=/path/to/dev\n" 2744 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n" 2745#endif 2746 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2747 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2748DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2749 "-nic [tap|bridge|" 2750#ifdef CONFIG_SLIRP 2751 "user|" 2752#endif 2753#ifdef __linux__ 2754 "l2tpv3|" 2755#endif 2756#ifdef CONFIG_VDE 2757 "vde|" 2758#endif 2759#ifdef CONFIG_NETMAP 2760 "netmap|" 2761#endif 2762#ifdef CONFIG_POSIX 2763 "vhost-user|" 2764#endif 2765 "socket][,option][,...][mac=macaddr]\n" 2766 " initialize an on-board / default host NIC (using MAC address\n" 2767 " macaddr) and connect it to the given host network backend\n" 2768 "-nic none use it alone to have zero network devices (the default is to\n" 2769 " provided a 'user' network connection)\n", 2770 QEMU_ARCH_ALL) 2771DEF("net", HAS_ARG, QEMU_OPTION_net, 2772 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2773 " configure or create an on-board (or machine default) NIC and\n" 2774 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2775 "-net [" 2776#ifdef CONFIG_SLIRP 2777 "user|" 2778#endif 2779 "tap|" 2780 "bridge|" 2781#ifdef CONFIG_VDE 2782 "vde|" 2783#endif 2784#ifdef CONFIG_NETMAP 2785 "netmap|" 2786#endif 2787 "socket][,option][,option][,...]\n" 2788 " old way to initialize a host network interface\n" 2789 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2790SRST 2791``-nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]`` 2792 This option is a shortcut for configuring both the on-board 2793 (default) guest NIC hardware and the host network backend in one go. 2794 The host backend options are the same as with the corresponding 2795 ``-netdev`` options below. The guest NIC model can be set with 2796 ``model=modelname``. Use ``model=help`` to list the available device 2797 types. The hardware MAC address can be set with ``mac=macaddr``. 2798 2799 The following two example do exactly the same, to show how ``-nic`` 2800 can be used to shorten the command line length: 2801 2802 .. parsed-literal:: 2803 2804 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2805 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2806 2807``-nic none`` 2808 Indicate that no network devices should be configured. It is used to 2809 override the default configuration (default NIC with "user" host 2810 network backend) which is activated if no other networking options 2811 are provided. 2812 2813``-netdev user,id=id[,option][,option][,...]`` 2814 Configure user mode host network backend which requires no 2815 administrator privilege to run. Valid options are: 2816 2817 ``id=id`` 2818 Assign symbolic name for use in monitor commands. 2819 2820 ``ipv4=on|off and ipv6=on|off`` 2821 Specify that either IPv4 or IPv6 must be enabled. If neither is 2822 specified both protocols are enabled. 2823 2824 ``net=addr[/mask]`` 2825 Set IP network address the guest will see. Optionally specify 2826 the netmask, either in the form a.b.c.d or as number of valid 2827 top-most bits. Default is 10.0.2.0/24. 2828 2829 ``host=addr`` 2830 Specify the guest-visible address of the host. Default is the 2831 2nd IP in the guest network, i.e. x.x.x.2. 2832 2833 ``ipv6-net=addr[/int]`` 2834 Set IPv6 network address the guest will see (default is 2835 fec0::/64). The network prefix is given in the usual hexadecimal 2836 IPv6 address notation. The prefix size is optional, and is given 2837 as the number of valid top-most bits (default is 64). 2838 2839 ``ipv6-host=addr`` 2840 Specify the guest-visible IPv6 address of the host. Default is 2841 the 2nd IPv6 in the guest network, i.e. xxxx::2. 2842 2843 ``restrict=on|off`` 2844 If this option is enabled, the guest will be isolated, i.e. it 2845 will not be able to contact the host and no guest IP packets 2846 will be routed over the host to the outside. This option does 2847 not affect any explicitly set forwarding rules. 2848 2849 ``hostname=name`` 2850 Specifies the client hostname reported by the built-in DHCP 2851 server. 2852 2853 ``dhcpstart=addr`` 2854 Specify the first of the 16 IPs the built-in DHCP server can 2855 assign. Default is the 15th to 31st IP in the guest network, 2856 i.e. x.x.x.15 to x.x.x.31. 2857 2858 ``dns=addr`` 2859 Specify the guest-visible address of the virtual nameserver. The 2860 address must be different from the host address. Default is the 2861 3rd IP in the guest network, i.e. x.x.x.3. 2862 2863 ``ipv6-dns=addr`` 2864 Specify the guest-visible address of the IPv6 virtual 2865 nameserver. The address must be different from the host address. 2866 Default is the 3rd IP in the guest network, i.e. xxxx::3. 2867 2868 ``dnssearch=domain`` 2869 Provides an entry for the domain-search list sent by the 2870 built-in DHCP server. More than one domain suffix can be 2871 transmitted by specifying this option multiple times. If 2872 supported, this will cause the guest to automatically try to 2873 append the given domain suffix(es) in case a domain name can not 2874 be resolved. 2875 2876 Example: 2877 2878 .. parsed-literal:: 2879 2880 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2881 2882 ``domainname=domain`` 2883 Specifies the client domain name reported by the built-in DHCP 2884 server. 2885 2886 ``tftp=dir`` 2887 When using the user mode network stack, activate a built-in TFTP 2888 server. The files in dir will be exposed as the root of a TFTP 2889 server. The TFTP client on the guest must be configured in 2890 binary mode (use the command ``bin`` of the Unix TFTP client). 2891 2892 ``tftp-server-name=name`` 2893 In BOOTP reply, broadcast name as the "TFTP server name" 2894 (RFC2132 option 66). This can be used to advise the guest to 2895 load boot files or configurations from a different server than 2896 the host address. 2897 2898 ``bootfile=file`` 2899 When using the user mode network stack, broadcast file as the 2900 BOOTP filename. In conjunction with ``tftp``, this can be used 2901 to network boot a guest from a local directory. 2902 2903 Example (using pxelinux): 2904 2905 .. parsed-literal:: 2906 2907 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\ 2908 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2909 2910 ``smb=dir[,smbserver=addr]`` 2911 When using the user mode network stack, activate a built-in SMB 2912 server so that Windows OSes can access to the host files in 2913 ``dir`` transparently. The IP address of the SMB server can be 2914 set to addr. By default the 4th IP in the guest network is used, 2915 i.e. x.x.x.4. 2916 2917 In the guest Windows OS, the line: 2918 2919 :: 2920 2921 10.0.2.4 smbserver 2922 2923 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows 2924 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows 2925 NT/2000). 2926 2927 Then ``dir`` can be accessed in ``\\smbserver\qemu``. 2928 2929 Note that a SAMBA server must be installed on the host OS. 2930 2931 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport`` 2932 Redirect incoming TCP or UDP connections to the host port 2933 hostport to the guest IP address guestaddr on guest port 2934 guestport. If guestaddr is not specified, its value is x.x.x.15 2935 (default first address given by the built-in DHCP server). By 2936 specifying hostaddr, the rule can be bound to a specific host 2937 interface. If no connection type is set, TCP is used. This 2938 option can be given multiple times. 2939 2940 For example, to redirect host X11 connection from screen 1 to 2941 guest screen 0, use the following: 2942 2943 .. parsed-literal:: 2944 2945 # on the host 2946 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2947 # this host xterm should open in the guest X11 server 2948 xterm -display :1 2949 2950 To redirect telnet connections from host port 5555 to telnet 2951 port on the guest, use the following: 2952 2953 .. parsed-literal:: 2954 2955 # on the host 2956 |qemu_system| -nic user,hostfwd=tcp::5555-:23 2957 telnet localhost 5555 2958 2959 Then when you use on the host ``telnet localhost 5555``, you 2960 connect to the guest telnet server. 2961 2962 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command`` 2963 Forward guest TCP connections to the IP address server on port 2964 port to the character device dev or to a program executed by 2965 cmd:command which gets spawned for each connection. This option 2966 can be given multiple times. 2967 2968 You can either use a chardev directly and have that one used 2969 throughout QEMU's lifetime, like in the following example: 2970 2971 .. parsed-literal:: 2972 2973 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2974 # the guest accesses it 2975 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2976 2977 Or you can execute a command on every TCP connection established 2978 by the guest, so that QEMU behaves similar to an inetd process 2979 for that virtual server: 2980 2981 .. parsed-literal:: 2982 2983 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2984 # and connect the TCP stream to its stdin/stdout 2985 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2986 2987``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` 2988 Configure a host TAP network backend with ID id. 2989 2990 Use the network script file to configure it and the network script 2991 dfile to deconfigure it. If name is not provided, the OS 2992 automatically provides one. The default network configure script is 2993 ``/etc/qemu-ifup`` and the default network deconfigure script is 2994 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to 2995 disable script execution. 2996 2997 If running QEMU as an unprivileged user, use the network helper 2998 to configure the TAP interface and attach it to the bridge. 2999 The default network helper executable is 3000 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3001 ``br0``. 3002 3003 ``fd``\ =h can be used to specify the handle of an already opened 3004 host TAP interface. 3005 3006 Examples: 3007 3008 .. parsed-literal:: 3009 3010 #launch a QEMU instance with the default network script 3011 |qemu_system| linux.img -nic tap 3012 3013 .. parsed-literal:: 3014 3015 #launch a QEMU instance with two NICs, each one connected 3016 #to a TAP device 3017 |qemu_system| linux.img \\ 3018 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\ 3019 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 3020 3021 .. parsed-literal:: 3022 3023 #launch a QEMU instance with the default network helper to 3024 #connect a TAP device to bridge br0 3025 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3026 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 3027 3028``-netdev bridge,id=id[,br=bridge][,helper=helper]`` 3029 Connect a host TAP network interface to a host bridge device. 3030 3031 Use the network helper helper to configure the TAP interface and 3032 attach it to the bridge. The default network helper executable is 3033 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3034 ``br0``. 3035 3036 Examples: 3037 3038 .. parsed-literal:: 3039 3040 #launch a QEMU instance with the default network helper to 3041 #connect a TAP device to bridge br0 3042 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 3043 3044 .. parsed-literal:: 3045 3046 #launch a QEMU instance with the default network helper to 3047 #connect a TAP device to bridge qemubr0 3048 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 3049 3050``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]`` 3051 This host network backend can be used to connect the guest's network 3052 to another QEMU virtual machine using a TCP socket connection. If 3053 ``listen`` is specified, QEMU waits for incoming connections on port 3054 (host is optional). ``connect`` is used to connect to another QEMU 3055 instance using the ``listen`` option. ``fd``\ =h specifies an 3056 already opened TCP socket. 3057 3058 Example: 3059 3060 .. parsed-literal:: 3061 3062 # launch a first QEMU instance 3063 |qemu_system| linux.img \\ 3064 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3065 -netdev socket,id=n1,listen=:1234 3066 # connect the network of this instance to the network of the first instance 3067 |qemu_system| linux.img \\ 3068 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3069 -netdev socket,id=n2,connect=127.0.0.1:1234 3070 3071``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]`` 3072 Configure a socket host network backend to share the guest's network 3073 traffic with another QEMU virtual machines using a UDP multicast 3074 socket, effectively making a bus for every QEMU with same multicast 3075 address maddr and port. NOTES: 3076 3077 1. Several QEMU can be running on different hosts and share same bus 3078 (assuming correct multicast setup for these hosts). 3079 3080 2. mcast support is compatible with User Mode Linux (argument 3081 ``ethN=mcast``), see http://user-mode-linux.sf.net. 3082 3083 3. Use ``fd=h`` to specify an already opened UDP multicast socket. 3084 3085 Example: 3086 3087 .. parsed-literal:: 3088 3089 # launch one QEMU instance 3090 |qemu_system| linux.img \\ 3091 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3092 -netdev socket,id=n1,mcast=230.0.0.1:1234 3093 # launch another QEMU instance on same "bus" 3094 |qemu_system| linux.img \\ 3095 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3096 -netdev socket,id=n2,mcast=230.0.0.1:1234 3097 # launch yet another QEMU instance on same "bus" 3098 |qemu_system| linux.img \\ 3099 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\ 3100 -netdev socket,id=n3,mcast=230.0.0.1:1234 3101 3102 Example (User Mode Linux compat.): 3103 3104 .. parsed-literal:: 3105 3106 # launch QEMU instance (note mcast address selected is UML's default) 3107 |qemu_system| linux.img \\ 3108 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3109 -netdev socket,id=n1,mcast=239.192.168.1:1102 3110 # launch UML 3111 /path/to/linux ubd0=/path/to/root_fs eth0=mcast 3112 3113 Example (send packets from host's 1.2.3.4): 3114 3115 .. parsed-literal:: 3116 3117 |qemu_system| linux.img \\ 3118 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3119 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 3120 3121``-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]`` 3122 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931) 3123 is a popular protocol to transport Ethernet (and other Layer 2) data 3124 frames between two systems. It is present in routers, firewalls and 3125 the Linux kernel (from version 3.3 onwards). 3126 3127 This transport allows a VM to communicate to another VM, router or 3128 firewall directly. 3129 3130 ``src=srcaddr`` 3131 source address (mandatory) 3132 3133 ``dst=dstaddr`` 3134 destination address (mandatory) 3135 3136 ``udp`` 3137 select udp encapsulation (default is ip). 3138 3139 ``srcport=srcport`` 3140 source udp port. 3141 3142 ``dstport=dstport`` 3143 destination udp port. 3144 3145 ``ipv6`` 3146 force v6, otherwise defaults to v4. 3147 3148 ``rxcookie=rxcookie``; \ ``txcookie=txcookie`` 3149 Cookies are a weak form of security in the l2tpv3 specification. 3150 Their function is mostly to prevent misconfiguration. By default 3151 they are 32 bit. 3152 3153 ``cookie64`` 3154 Set cookie size to 64 bit instead of the default 32 3155 3156 ``counter=off`` 3157 Force a 'cut-down' L2TPv3 with no counter as in 3158 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 3159 3160 ``pincounter=on`` 3161 Work around broken counter handling in peer. This may also help 3162 on networks which have packet reorder. 3163 3164 ``offset=offset`` 3165 Add an extra offset between header and data 3166 3167 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to 3168 the bridge br-lan on the remote Linux host 1.2.3.4: 3169 3170 .. parsed-literal:: 3171 3172 # Setup tunnel on linux host using raw ip as encapsulation 3173 # on 1.2.3.4 3174 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\ 3175 encap udp udp_sport 16384 udp_dport 16384 3176 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\ 3177 0xFFFFFFFF peer_session_id 0xFFFFFFFF 3178 ifconfig vmtunnel0 mtu 1500 3179 ifconfig vmtunnel0 up 3180 brctl addif br-lan vmtunnel0 3181 3182 3183 # on 4.3.2.1 3184 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 3185 3186 |qemu_system| linux.img -device e1000,netdev=n1 \\ 3187 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 3188 3189``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]`` 3190 Configure VDE backend to connect to PORT n of a vde switch running 3191 on host and listening for incoming connections on socketpath. Use 3192 GROUP groupname and MODE octalmode to change default ownership and 3193 permissions for communication port. This option is only available if 3194 QEMU has been compiled with vde support enabled. 3195 3196 Example: 3197 3198 .. parsed-literal:: 3199 3200 # launch vde switch 3201 vde_switch -F -sock /tmp/myswitch 3202 # launch QEMU instance 3203 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch 3204 3205``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` 3206 Establish a vhost-user netdev, backed by a chardev id. The chardev 3207 should be a unix domain socket backed one. The vhost-user uses a 3208 specifically defined protocol to pass vhost ioctl replacement 3209 messages to an application on the other end of the socket. On 3210 non-MSIX guests, the feature can be forced with vhostforce. Use 3211 'queues=n' to specify the number of queues to be created for 3212 multiqueue vhost-user. 3213 3214 Example: 3215 3216 :: 3217 3218 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 3219 -numa node,memdev=mem \ 3220 -chardev socket,id=chr0,path=/path/to/socket \ 3221 -netdev type=vhost-user,id=net0,chardev=chr0 \ 3222 -device virtio-net-pci,netdev=net0 3223 3224``-netdev vhost-vdpa,vhostdev=/path/to/dev`` 3225 Establish a vhost-vdpa netdev. 3226 3227 vDPA device is a device that uses a datapath which complies with 3228 the virtio specifications with a vendor specific control path. 3229 vDPA devices can be both physically located on the hardware or 3230 emulated by software. 3231 3232``-netdev hubport,id=id,hubid=hubid[,netdev=nd]`` 3233 Create a hub port on the emulated hub with ID hubid. 3234 3235 The hubport netdev lets you connect a NIC to a QEMU emulated hub 3236 instead of a single netdev. Alternatively, you can also connect the 3237 hubport to another netdev with ID nd by using the ``netdev=nd`` 3238 option. 3239 3240``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]`` 3241 Legacy option to configure or create an on-board (or machine 3242 default) Network Interface Card(NIC) and connect it either to the 3243 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd. 3244 If model is omitted, then the default NIC model associated with the 3245 machine type is used. Note that the default NIC model may change in 3246 future QEMU releases, so it is highly recommended to always specify 3247 a model. Optionally, the MAC address can be changed to mac, the 3248 device address set to addr (PCI cards only), and a name can be 3249 assigned for use in monitor commands. Optionally, for PCI cards, you 3250 can specify the number v of MSI-X vectors that the card should have; 3251 this option currently only affects virtio cards; set v = 0 to 3252 disable MSI-X. If no ``-net`` option is specified, a single NIC is 3253 created. QEMU can emulate several different models of network card. 3254 Use ``-net nic,model=help`` for a list of available devices for your 3255 target. 3256 3257``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]`` 3258 Configure a host network backend (with the options corresponding to 3259 the same ``-netdev`` option) and connect it to the emulated hub 0 3260 (the default hub). Use name to specify the name of the hub port. 3261ERST 3262 3263DEFHEADING() 3264 3265DEFHEADING(Character device options:) 3266 3267DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 3268 "-chardev help\n" 3269 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3270 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n" 3271 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" 3272 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 3273 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" 3274 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" 3275 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 3276 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n" 3277 " [,logfile=PATH][,logappend=on|off]\n" 3278 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3279 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 3280 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3281 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 3282 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3283 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3284#ifdef _WIN32 3285 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3286 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3287#else 3288 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3289 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 3290#endif 3291#ifdef CONFIG_BRLAPI 3292 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3293#endif 3294#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 3295 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 3296 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3297 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3298#endif 3299#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 3300 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3301 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3302#endif 3303#if defined(CONFIG_SPICE) 3304 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3305 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3306#endif 3307 , QEMU_ARCH_ALL 3308) 3309 3310SRST 3311The general form of a character device option is: 3312 3313``-chardev backend,id=id[,mux=on|off][,options]`` 3314 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, 3315 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, 3316 ``pty``, ``stdio``, ``braille``, ``tty``, ``parallel``, ``parport``, 3317 ``spicevmc``, ``spiceport``. The specific backend will determine the 3318 applicable options. 3319 3320 Use ``-chardev help`` to print all available chardev backend types. 3321 3322 All devices must have an id, which can be any string up to 127 3323 characters long. It is used to uniquely identify this device in 3324 other command line directives. 3325 3326 A character device may be used in multiplexing mode by multiple 3327 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is 3328 a "1:N" device, and here the "1" end is your specified chardev 3329 backend, and the "N" end is the various parts of QEMU that can talk 3330 to a chardev. If you create a chardev with ``id=myid`` and 3331 ``mux=on``, QEMU will create a multiplexer with your specified ID, 3332 and you can then configure multiple front ends to use that chardev 3333 ID for their input/output. Up to four different front ends can be 3334 connected to a single multiplexed chardev. (Without multiplexing 3335 enabled, a chardev can only be used by a single front end.) For 3336 instance you could use this to allow a single stdio chardev to be 3337 used by two serial ports and the QEMU monitor: 3338 3339 :: 3340 3341 -chardev stdio,mux=on,id=char0 \ 3342 -mon chardev=char0,mode=readline \ 3343 -serial chardev:char0 \ 3344 -serial chardev:char0 3345 3346 You can have more than one multiplexer in a system configuration; 3347 for instance you could have a TCP port multiplexed between UART 0 3348 and UART 1, and stdio multiplexed between the QEMU monitor and a 3349 parallel port: 3350 3351 :: 3352 3353 -chardev stdio,mux=on,id=char0 \ 3354 -mon chardev=char0,mode=readline \ 3355 -parallel chardev:char0 \ 3356 -chardev tcp,...,mux=on,id=char1 \ 3357 -serial chardev:char1 \ 3358 -serial chardev:char1 3359 3360 When you're using a multiplexed character device, some escape 3361 sequences are interpreted in the input. See the chapter about 3362 :ref:`keys in the character backend multiplexer` in the 3363 System Emulation Users Guide for more details. 3364 3365 Note that some other command line options may implicitly create 3366 multiplexed character backends; for instance ``-serial mon:stdio`` 3367 creates a multiplexed stdio backend connected to the serial port and 3368 the QEMU monitor, and ``-nographic`` also multiplexes the console 3369 and the monitor to stdio. 3370 3371 There is currently no support for multiplexing in the other 3372 direction (where a single QEMU front end takes input and output from 3373 multiple chardevs). 3374 3375 Every backend supports the ``logfile`` option, which supplies the 3376 path to a file to record all data transmitted via the backend. The 3377 ``logappend`` option controls whether the log file will be truncated 3378 or appended to when opened. 3379 3380The available backends are: 3381 3382``-chardev null,id=id`` 3383 A void device. This device will not emit any data, and will drop any 3384 data it receives. The null backend does not take any options. 3385 3386``-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]`` 3387 Create a two-way stream socket, which can be either a TCP or a unix 3388 socket. A unix socket will be created if ``path`` is specified. 3389 Behaviour is undefined if TCP options are specified for a unix 3390 socket. 3391 3392 ``server=on|off`` specifies that the socket shall be a listening socket. 3393 3394 ``wait=on|off`` specifies that QEMU should not block waiting for a client 3395 to connect to a listening socket. 3396 3397 ``telnet=on|off`` specifies that traffic on the socket should interpret 3398 telnet escape sequences. 3399 3400 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for 3401 communication. 3402 3403 ``reconnect`` sets the timeout for reconnecting on non-server 3404 sockets when the remote end goes away. qemu will delay this many 3405 seconds and then attempt to reconnect. Zero disables reconnecting, 3406 and is the default. 3407 3408 ``tls-creds`` requests enablement of the TLS protocol for 3409 encryption, and specifies the id of the TLS credentials to use for 3410 the handshake. The credentials must be previously created with the 3411 ``-object tls-creds`` argument. 3412 3413 ``tls-auth`` provides the ID of the QAuthZ authorization object 3414 against which the client's x509 distinguished name will be 3415 validated. This object is only resolved at time of use, so can be 3416 deleted and recreated on the fly while the chardev server is active. 3417 If missing, it will default to denying access. 3418 3419 TCP and unix socket options are given below: 3420 3421 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]`` 3422 ``host`` for a listening socket specifies the local address to 3423 be bound. For a connecting socket species the remote host to 3424 connect to. ``host`` is optional for listening sockets. If not 3425 specified it defaults to ``0.0.0.0``. 3426 3427 ``port`` for a listening socket specifies the local port to be 3428 bound. For a connecting socket specifies the port on the remote 3429 host to connect to. ``port`` can be given as either a port 3430 number or a service name. ``port`` is required. 3431 3432 ``to`` is only relevant to listening sockets. If it is 3433 specified, and ``port`` cannot be bound, QEMU will attempt to 3434 bind to subsequent ports up to and including ``to`` until it 3435 succeeds. ``to`` must be specified as a port number. 3436 3437 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 3438 or IPv6 must be used. If neither is specified the socket may 3439 use either protocol. 3440 3441 ``nodelay=on|off`` disables the Nagle algorithm. 3442 3443 ``unix options: path=path[,abstract=on|off][,tight=on|off]`` 3444 ``path`` specifies the local path of the unix socket. ``path`` 3445 is required. 3446 ``abstract=on|off`` specifies the use of the abstract socket namespace, 3447 rather than the filesystem. Optional, defaults to false. 3448 ``tight=on|off`` sets the socket length of abstract sockets to their minimum, 3449 rather than the full sun_path length. Optional, defaults to true. 3450 3451``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4=on|off][,ipv6=on|off]`` 3452 Sends all traffic from the guest to a remote host over UDP. 3453 3454 ``host`` specifies the remote host to connect to. If not specified 3455 it defaults to ``localhost``. 3456 3457 ``port`` specifies the port on the remote host to connect to. 3458 ``port`` is required. 3459 3460 ``localaddr`` specifies the local address to bind to. If not 3461 specified it defaults to ``0.0.0.0``. 3462 3463 ``localport`` specifies the local port to bind to. If not specified 3464 any available local port will be used. 3465 3466 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used. 3467 If neither is specified the device may use either protocol. 3468 3469``-chardev msmouse,id=id`` 3470 Forward QEMU's emulated msmouse events to the guest. ``msmouse`` 3471 does not take any options. 3472 3473``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` 3474 Connect to a QEMU text console. ``vc`` may optionally be given a 3475 specific size. 3476 3477 ``width`` and ``height`` specify the width and height respectively 3478 of the console, in pixels. 3479 3480 ``cols`` and ``rows`` specify that the console be sized to fit a 3481 text console with the given dimensions. 3482 3483``-chardev ringbuf,id=id[,size=size]`` 3484 Create a ring buffer with fixed size ``size``. size must be a power 3485 of two and defaults to ``64K``. 3486 3487``-chardev file,id=id,path=path`` 3488 Log all traffic received from the guest to a file. 3489 3490 ``path`` specifies the path of the file to be opened. This file will 3491 be created if it does not already exist, and overwritten if it does. 3492 ``path`` is required. 3493 3494``-chardev pipe,id=id,path=path`` 3495 Create a two-way connection to the guest. The behaviour differs 3496 slightly between Windows hosts and other hosts: 3497 3498 On Windows, a single duplex pipe will be created at 3499 ``\\.pipe\path``. 3500 3501 On other hosts, 2 pipes will be created called ``path.in`` and 3502 ``path.out``. Data written to ``path.in`` will be received by the 3503 guest. Data written by the guest can be read from ``path.out``. QEMU 3504 will not create these fifos, and requires them to be present. 3505 3506 ``path`` forms part of the pipe path as described above. ``path`` is 3507 required. 3508 3509``-chardev console,id=id`` 3510 Send traffic from the guest to QEMU's standard output. ``console`` 3511 does not take any options. 3512 3513 ``console`` is only available on Windows hosts. 3514 3515``-chardev serial,id=id,path=path`` 3516 Send traffic from the guest to a serial device on the host. 3517 3518 On Unix hosts serial will actually accept any tty device, not only 3519 serial lines. 3520 3521 ``path`` specifies the name of the serial device to open. 3522 3523``-chardev pty,id=id`` 3524 Create a new pseudo-terminal on the host and connect to it. ``pty`` 3525 does not take any options. 3526 3527 ``pty`` is not available on Windows hosts. 3528 3529``-chardev stdio,id=id[,signal=on|off]`` 3530 Connect to standard input and standard output of the QEMU process. 3531 3532 ``signal`` controls if signals are enabled on the terminal, that 3533 includes exiting QEMU with the key sequence Control-c. This option 3534 is enabled by default, use ``signal=off`` to disable it. 3535 3536``-chardev braille,id=id`` 3537 Connect to a local BrlAPI server. ``braille`` does not take any 3538 options. 3539 3540``-chardev tty,id=id,path=path`` 3541 ``tty`` is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD 3542 and DragonFlyBSD hosts. It is an alias for ``serial``. 3543 3544 ``path`` specifies the path to the tty. ``path`` is required. 3545 3546``-chardev parallel,id=id,path=path`` 3547 \ 3548``-chardev parport,id=id,path=path`` 3549 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD 3550 hosts. 3551 3552 Connect to a local parallel port. 3553 3554 ``path`` specifies the path to the parallel port device. ``path`` is 3555 required. 3556 3557``-chardev spicevmc,id=id,debug=debug,name=name`` 3558 ``spicevmc`` is only available when spice support is built in. 3559 3560 ``debug`` debug level for spicevmc 3561 3562 ``name`` name of spice channel to connect to 3563 3564 Connect to a spice virtual machine channel, such as vdiport. 3565 3566``-chardev spiceport,id=id,debug=debug,name=name`` 3567 ``spiceport`` is only available when spice support is built in. 3568 3569 ``debug`` debug level for spicevmc 3570 3571 ``name`` name of spice port to connect to 3572 3573 Connect to a spice port, allowing a Spice client to handle the 3574 traffic identified by a name (preferably a fqdn). 3575ERST 3576 3577DEFHEADING() 3578 3579#ifdef CONFIG_TPM 3580DEFHEADING(TPM device options:) 3581 3582DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3583 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3584 " use path to provide path to a character device; default is /dev/tpm0\n" 3585 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3586 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3587 "-tpmdev emulator,id=id,chardev=dev\n" 3588 " configure the TPM device using chardev backend\n", 3589 QEMU_ARCH_ALL) 3590SRST 3591The general form of a TPM device option is: 3592 3593``-tpmdev backend,id=id[,options]`` 3594 The specific backend type will determine the applicable options. The 3595 ``-tpmdev`` option creates the TPM backend and requires a 3596 ``-device`` option that specifies the TPM frontend interface model. 3597 3598 Use ``-tpmdev help`` to print all available TPM backend types. 3599 3600The available backends are: 3601 3602``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path`` 3603 (Linux-host only) Enable access to the host's TPM using the 3604 passthrough driver. 3605 3606 ``path`` specifies the path to the host's TPM device, i.e., on a 3607 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by 3608 default ``/dev/tpm0`` is used. 3609 3610 ``cancel-path`` specifies the path to the host TPM device's sysfs 3611 entry allowing for cancellation of an ongoing TPM command. 3612 ``cancel-path`` is optional and by default QEMU will search for the 3613 sysfs entry to use. 3614 3615 Some notes about using the host's TPM with the passthrough driver: 3616 3617 The TPM device accessed by the passthrough driver must not be used 3618 by any other application on the host. 3619 3620 Since the host's firmware (BIOS/UEFI) has already initialized the 3621 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize 3622 the TPM again and may therefore not show a TPM-specific menu that 3623 would otherwise allow the user to configure the TPM, e.g., allow the 3624 user to enable/disable or activate/deactivate the TPM. Further, if 3625 TPM ownership is released from within a VM then the host's TPM will 3626 get disabled and deactivated. To enable and activate the TPM again 3627 afterwards, the host has to be rebooted and the user is required to 3628 enter the firmware's menu to enable and activate the TPM. If the TPM 3629 is left disabled and/or deactivated most TPM commands will fail. 3630 3631 To create a passthrough TPM use the following two options: 3632 3633 :: 3634 3635 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3636 3637 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by 3638 ``tpmdev=tpm0`` in the device option. 3639 3640``-tpmdev emulator,id=id,chardev=dev`` 3641 (Linux-host only) Enable access to a TPM emulator using Unix domain 3642 socket based chardev backend. 3643 3644 ``chardev`` specifies the unique ID of a character device backend 3645 that provides connection to the software TPM server. 3646 3647 To create a TPM emulator backend device with chardev socket backend: 3648 3649 :: 3650 3651 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3652ERST 3653 3654DEFHEADING() 3655 3656#endif 3657 3658DEFHEADING(Linux/Multiboot boot specific:) 3659SRST 3660When using these options, you can use a given Linux or Multiboot kernel 3661without installing it in the disk image. It can be useful for easier 3662testing of various kernels. 3663 3664 3665ERST 3666 3667DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3668 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3669SRST 3670``-kernel bzImage`` 3671 Use bzImage as kernel image. The kernel can be either a Linux kernel 3672 or in multiboot format. 3673ERST 3674 3675DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3676 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3677SRST 3678``-append cmdline`` 3679 Use cmdline as kernel command line 3680ERST 3681 3682DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3683 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3684SRST 3685``-initrd file`` 3686 Use file as initial ram disk. 3687 3688``-initrd "file1 arg=foo,file2"`` 3689 This syntax is only available with multiboot. 3690 3691 Use file1 and file2 as modules and pass arg=foo as parameter to the 3692 first module. 3693ERST 3694 3695DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3696 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3697SRST 3698``-dtb file`` 3699 Use file as a device tree binary (dtb) image and pass it to the 3700 kernel on boot. 3701ERST 3702 3703DEFHEADING() 3704 3705DEFHEADING(Debug/Expert options:) 3706 3707DEF("compat", HAS_ARG, QEMU_OPTION_compat, 3708 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n" 3709 " Policy for handling deprecated management interfaces\n" 3710 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n" 3711 " Policy for handling unstable management interfaces\n", 3712 QEMU_ARCH_ALL) 3713SRST 3714``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]`` 3715 Set policy for handling deprecated management interfaces (experimental): 3716 3717 ``deprecated-input=accept`` (default) 3718 Accept deprecated commands and arguments 3719 ``deprecated-input=reject`` 3720 Reject deprecated commands and arguments 3721 ``deprecated-input=crash`` 3722 Crash on deprecated commands and arguments 3723 ``deprecated-output=accept`` (default) 3724 Emit deprecated command results and events 3725 ``deprecated-output=hide`` 3726 Suppress deprecated command results and events 3727 3728 Limitation: covers only syntactic aspects of QMP. 3729 3730``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]`` 3731 Set policy for handling unstable management interfaces (experimental): 3732 3733 ``unstable-input=accept`` (default) 3734 Accept unstable commands and arguments 3735 ``unstable-input=reject`` 3736 Reject unstable commands and arguments 3737 ``unstable-input=crash`` 3738 Crash on unstable commands and arguments 3739 ``unstable-output=accept`` (default) 3740 Emit unstable command results and events 3741 ``unstable-output=hide`` 3742 Suppress unstable command results and events 3743 3744 Limitation: covers only syntactic aspects of QMP. 3745ERST 3746 3747DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3748 "-fw_cfg [name=]<name>,file=<file>\n" 3749 " add named fw_cfg entry with contents from file\n" 3750 "-fw_cfg [name=]<name>,string=<str>\n" 3751 " add named fw_cfg entry with contents from string\n", 3752 QEMU_ARCH_ALL) 3753SRST 3754``-fw_cfg [name=]name,file=file`` 3755 Add named fw\_cfg entry with contents from file file. 3756 3757``-fw_cfg [name=]name,string=str`` 3758 Add named fw\_cfg entry with contents from string str. 3759 3760 The terminating NUL character of the contents of str will not be 3761 included as part of the fw\_cfg item data. To insert contents with 3762 embedded NUL characters, you have to use the file parameter. 3763 3764 The fw\_cfg entries are passed by QEMU through to the guest. 3765 3766 Example: 3767 3768 :: 3769 3770 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3771 3772 creates an fw\_cfg entry named opt/com.mycompany/blob with contents 3773 from ./my\_blob.bin. 3774ERST 3775 3776DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3777 "-serial dev redirect the serial port to char device 'dev'\n", 3778 QEMU_ARCH_ALL) 3779SRST 3780``-serial dev`` 3781 Redirect the virtual serial port to host character device dev. The 3782 default device is ``vc`` in graphical mode and ``stdio`` in non 3783 graphical mode. 3784 3785 This option can be used several times to simulate up to 4 serial 3786 ports. 3787 3788 Use ``-serial none`` to disable all serial ports. 3789 3790 Available character devices are: 3791 3792 ``vc[:WxH]`` 3793 Virtual console. Optionally, a width and height can be given in 3794 pixel with 3795 3796 :: 3797 3798 vc:800x600 3799 3800 It is also possible to specify width or height in characters: 3801 3802 :: 3803 3804 vc:80Cx24C 3805 3806 ``pty`` 3807 [Linux only] Pseudo TTY (a new PTY is automatically allocated) 3808 3809 ``none`` 3810 No device is allocated. 3811 3812 ``null`` 3813 void device 3814 3815 ``chardev:id`` 3816 Use a named character device defined with the ``-chardev`` 3817 option. 3818 3819 ``/dev/XXX`` 3820 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial 3821 port parameters are set according to the emulated ones. 3822 3823 ``/dev/parportN`` 3824 [Linux only, parallel port only] Use host parallel port N. 3825 Currently SPP and EPP parallel port features can be used. 3826 3827 ``file:filename`` 3828 Write output to filename. No character can be read. 3829 3830 ``stdio`` 3831 [Unix only] standard input/output 3832 3833 ``pipe:filename`` 3834 name pipe filename 3835 3836 ``COMn`` 3837 [Windows only] Use host serial port n 3838 3839 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]`` 3840 This implements UDP Net Console. When remote\_host or src\_ip 3841 are not specified they default to ``0.0.0.0``. When not using a 3842 specified src\_port a random port is automatically chosen. 3843 3844 If you just want a simple readonly console you can use 3845 ``netcat`` or ``nc``, by starting QEMU with: 3846 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time 3847 QEMU writes something to that port it will appear in the 3848 netconsole session. 3849 3850 If you plan to send characters back via netconsole or you want 3851 to stop and start QEMU a lot of times, you should have QEMU use 3852 the same source port each time by using something like ``-serial 3853 udp::4555@:4556`` to QEMU. Another approach is to use a patched 3854 version of netcat which can listen to a TCP port and send and 3855 receive characters via udp. If you have a patched version of 3856 netcat which activates telnet remote echo and single char 3857 transfer, then you can use the following options to set up a 3858 netcat redirector to allow telnet on port 5555 to access the 3859 QEMU port. 3860 3861 ``QEMU Options:`` 3862 -serial udp::4555@:4556 3863 3864 ``netcat options:`` 3865 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3866 3867 ``telnet options:`` 3868 localhost 5555 3869 3870 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]`` 3871 The TCP Net Console has two modes of operation. It can send the 3872 serial I/O to a location or wait for a connection from a 3873 location. By default the TCP Net Console is sent to host at the 3874 port. If you use the ``server=on`` option QEMU will wait for a client 3875 socket application to connect to the port before continuing, 3876 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off`` 3877 option disables the Nagle buffering algorithm. The ``reconnect=on`` 3878 option only applies if ``server=no`` is set, if the connection goes 3879 down it will attempt to reconnect at the given interval. If host 3880 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a 3881 time is accepted. You can use ``telnet=on`` to connect to the 3882 corresponding character device. 3883 3884 ``Example to send tcp console to 192.168.0.2 port 4444`` 3885 -serial tcp:192.168.0.2:4444 3886 3887 ``Example to listen and wait on port 4444 for connection`` 3888 -serial tcp::4444,server=on 3889 3890 ``Example to not wait and listen on ip 192.168.0.100 port 4444`` 3891 -serial tcp:192.168.0.100:4444,server=on,wait=off 3892 3893 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]`` 3894 The telnet protocol is used instead of raw tcp sockets. The 3895 options work the same as if you had specified ``-serial tcp``. 3896 The difference is that the port acts like a telnet server or 3897 client using telnet option negotiation. This will also allow you 3898 to send the MAGIC\_SYSRQ sequence if you use a telnet that 3899 supports sending the break sequence. Typically in unix telnet 3900 you do it with Control-] and then type "send break" followed by 3901 pressing the enter key. 3902 3903 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]`` 3904 The WebSocket protocol is used instead of raw tcp socket. The 3905 port acts as a WebSocket server. Client mode is not supported. 3906 3907 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]`` 3908 A unix domain socket is used instead of a tcp socket. The option 3909 works the same as if you had specified ``-serial tcp`` except 3910 the unix domain socket path is used for connections. 3911 3912 ``mon:dev_string`` 3913 This is a special option to allow the monitor to be multiplexed 3914 onto another serial port. The monitor is accessed with key 3915 sequence of Control-a and then pressing c. dev\_string should be 3916 any one of the serial devices specified above. An example to 3917 multiplex the monitor onto a telnet server listening on port 3918 4444 would be: 3919 3920 ``-serial mon:telnet::4444,server=on,wait=off`` 3921 3922 When the monitor is multiplexed to stdio in this way, Ctrl+C 3923 will not terminate QEMU any more but will be passed to the guest 3924 instead. 3925 3926 ``braille`` 3927 Braille device. This will use BrlAPI to display the braille 3928 output on a real or fake device. 3929 3930 ``msmouse`` 3931 Three button serial mouse. Configure the guest to use Microsoft 3932 protocol. 3933ERST 3934 3935DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3936 "-parallel dev redirect the parallel port to char device 'dev'\n", 3937 QEMU_ARCH_ALL) 3938SRST 3939``-parallel dev`` 3940 Redirect the virtual parallel port to host device dev (same devices 3941 as the serial port). On Linux hosts, ``/dev/parportN`` can be used 3942 to use hardware devices connected on the corresponding host parallel 3943 port. 3944 3945 This option can be used several times to simulate up to 3 parallel 3946 ports. 3947 3948 Use ``-parallel none`` to disable all parallel ports. 3949ERST 3950 3951DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3952 "-monitor dev redirect the monitor to char device 'dev'\n", 3953 QEMU_ARCH_ALL) 3954SRST 3955``-monitor dev`` 3956 Redirect the monitor to host device dev (same devices as the serial 3957 port). The default device is ``vc`` in graphical mode and ``stdio`` 3958 in non graphical mode. Use ``-monitor none`` to disable the default 3959 monitor. 3960ERST 3961DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3962 "-qmp dev like -monitor but opens in 'control' mode\n", 3963 QEMU_ARCH_ALL) 3964SRST 3965``-qmp dev`` 3966 Like -monitor but opens in 'control' mode. 3967ERST 3968DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3969 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3970 QEMU_ARCH_ALL) 3971SRST 3972``-qmp-pretty dev`` 3973 Like -qmp but uses pretty JSON formatting. 3974ERST 3975 3976DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3977 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3978SRST 3979``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]`` 3980 Setup monitor on chardev name. ``mode=control`` configures 3981 a QMP monitor (a JSON RPC-style protocol) and it is not the 3982 same as HMP, the human monitor that has a "(qemu)" prompt. 3983 ``pretty`` is only valid when ``mode=control``, 3984 turning on JSON pretty printing to ease 3985 human reading and debugging. 3986ERST 3987 3988DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3989 "-debugcon dev redirect the debug console to char device 'dev'\n", 3990 QEMU_ARCH_ALL) 3991SRST 3992``-debugcon dev`` 3993 Redirect the debug console to host device dev (same devices as the 3994 serial port). The debug console is an I/O port which is typically 3995 port 0xe9; writing to that I/O port sends output to this device. The 3996 default device is ``vc`` in graphical mode and ``stdio`` in non 3997 graphical mode. 3998ERST 3999 4000DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 4001 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 4002SRST 4003``-pidfile file`` 4004 Store the QEMU process PID in file. It is useful if you launch QEMU 4005 from a script. 4006ERST 4007 4008DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 4009 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 4010SRST 4011``-singlestep`` 4012 Run the emulation in single step mode. 4013ERST 4014 4015DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 4016 "--preconfig pause QEMU before machine is initialized (experimental)\n", 4017 QEMU_ARCH_ALL) 4018SRST 4019``--preconfig`` 4020 Pause QEMU for interactive configuration before the machine is 4021 created, which allows querying and configuring properties that will 4022 affect machine initialization. Use QMP command 'x-exit-preconfig' to 4023 exit the preconfig state and move to the next state (i.e. run guest 4024 if -S isn't used or pause the second time if -S is used). This 4025 option is experimental. 4026ERST 4027 4028DEF("S", 0, QEMU_OPTION_S, \ 4029 "-S freeze CPU at startup (use 'c' to start execution)\n", 4030 QEMU_ARCH_ALL) 4031SRST 4032``-S`` 4033 Do not start CPU at startup (you must type 'c' in the monitor). 4034ERST 4035 4036DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 4037 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 4038 " run qemu with overcommit hints\n" 4039 " mem-lock=on|off controls memory lock support (default: off)\n" 4040 " cpu-pm=on|off controls cpu power management (default: off)\n", 4041 QEMU_ARCH_ALL) 4042SRST 4043``-overcommit mem-lock=on|off`` 4044 \ 4045``-overcommit cpu-pm=on|off`` 4046 Run qemu with hints about host resource overcommit. The default is 4047 to assume that host overcommits all resources. 4048 4049 Locking qemu and guest memory can be enabled via ``mem-lock=on`` 4050 (disabled by default). This works when host memory is not 4051 overcommitted and reduces the worst-case latency for guest. 4052 4053 Guest ability to manage power state of host cpus (increasing latency 4054 for other processes on the same host cpu, but decreasing latency for 4055 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This 4056 works best when host CPU is not overcommitted. When used, host 4057 estimates of CPU cycle and power utilization will be incorrect, not 4058 taking into account guest idle time. 4059ERST 4060 4061DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 4062 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n" 4063 " the guest without waiting for gdb to connect; use -S too\n" 4064 " if you want it to not start execution.)\n", 4065 QEMU_ARCH_ALL) 4066SRST 4067``-gdb dev`` 4068 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter 4069 in the System Emulation Users Guide). Note that this option does not pause QEMU 4070 execution -- if you want QEMU to not start the guest until you 4071 connect with gdb and issue a ``continue`` command, you will need to 4072 also pass the ``-S`` option to QEMU. 4073 4074 The most usual configuration is to listen on a local TCP socket:: 4075 4076 -gdb tcp::3117 4077 4078 but you can specify other backends; UDP, pseudo TTY, or even stdio 4079 are all reasonable use cases. For example, a stdio connection 4080 allows you to start QEMU from within gdb and establish the 4081 connection via a pipe: 4082 4083 .. parsed-literal:: 4084 4085 (gdb) target remote | exec |qemu_system| -gdb stdio ... 4086ERST 4087 4088DEF("s", 0, QEMU_OPTION_s, \ 4089 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 4090 QEMU_ARCH_ALL) 4091SRST 4092``-s`` 4093 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 4094 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide). 4095ERST 4096 4097DEF("d", HAS_ARG, QEMU_OPTION_d, \ 4098 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 4099 QEMU_ARCH_ALL) 4100SRST 4101``-d item1[,...]`` 4102 Enable logging of specified items. Use '-d help' for a list of log 4103 items. 4104ERST 4105 4106DEF("D", HAS_ARG, QEMU_OPTION_D, \ 4107 "-D logfile output log to logfile (default stderr)\n", 4108 QEMU_ARCH_ALL) 4109SRST 4110``-D logfile`` 4111 Output log in logfile instead of to stderr 4112ERST 4113 4114DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 4115 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 4116 QEMU_ARCH_ALL) 4117SRST 4118``-dfilter range1[,...]`` 4119 Filter debug output to that relevant to a range of target addresses. 4120 The filter spec can be either start+size, start-size or start..end 4121 where start end and size are the addresses and sizes required. For 4122 example: 4123 4124 :: 4125 4126 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 4127 4128 Will dump output for any code in the 0x1000 sized block starting at 4129 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and 4130 another 0x1000 sized block starting at 0xffffffc00005f000. 4131ERST 4132 4133DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 4134 "-seed number seed the pseudo-random number generator\n", 4135 QEMU_ARCH_ALL) 4136SRST 4137``-seed number`` 4138 Force the guest to use a deterministic pseudo-random number 4139 generator, seeded with number. This does not affect crypto routines 4140 within the host. 4141ERST 4142 4143DEF("L", HAS_ARG, QEMU_OPTION_L, \ 4144 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 4145 QEMU_ARCH_ALL) 4146SRST 4147``-L path`` 4148 Set the directory for the BIOS, VGA BIOS and keymaps. 4149 4150 To list all the data directories, use ``-L help``. 4151ERST 4152 4153DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 4154 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 4155SRST 4156``-bios file`` 4157 Set the filename for the BIOS. 4158ERST 4159 4160DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 4161 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 4162SRST 4163``-enable-kvm`` 4164 Enable KVM full virtualization support. This option is only 4165 available if KVM support is enabled when compiling. 4166ERST 4167 4168DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 4169 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 4170DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 4171 "-xen-attach attach to existing xen domain\n" 4172 " libxl will use this when starting QEMU\n", 4173 QEMU_ARCH_ALL) 4174DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 4175 "-xen-domid-restrict restrict set of available xen operations\n" 4176 " to specified domain id. (Does not affect\n" 4177 " xenpv machine type).\n", 4178 QEMU_ARCH_ALL) 4179SRST 4180``-xen-domid id`` 4181 Specify xen guest domain id (XEN only). 4182 4183``-xen-attach`` 4184 Attach to existing xen domain. libxl will use this when starting 4185 QEMU (XEN only). Restrict set of available xen operations to 4186 specified domain id (XEN only). 4187ERST 4188 4189DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 4190 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 4191SRST 4192``-no-reboot`` 4193 Exit instead of rebooting. 4194ERST 4195 4196DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 4197 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 4198SRST 4199``-no-shutdown`` 4200 Don't exit QEMU on guest shutdown, but instead only stop the 4201 emulation. This allows for instance switching to monitor to commit 4202 changes to the disk image. 4203ERST 4204 4205DEF("action", HAS_ARG, QEMU_OPTION_action, 4206 "-action reboot=reset|shutdown\n" 4207 " action when guest reboots [default=reset]\n" 4208 "-action shutdown=poweroff|pause\n" 4209 " action when guest shuts down [default=poweroff]\n" 4210 "-action panic=pause|shutdown|none\n" 4211 " action when guest panics [default=shutdown]\n" 4212 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" 4213 " action when watchdog fires [default=reset]\n", 4214 QEMU_ARCH_ALL) 4215SRST 4216``-action event=action`` 4217 The action parameter serves to modify QEMU's default behavior when 4218 certain guest events occur. It provides a generic method for specifying the 4219 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown`` 4220 parameters. 4221 4222 Examples: 4223 4224 ``-action panic=none`` 4225 ``-action reboot=shutdown,shutdown=pause`` 4226 ``-watchdog i6300esb -action watchdog=pause`` 4227 4228ERST 4229 4230DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 4231 "-loadvm [tag|id]\n" \ 4232 " start right away with a saved state (loadvm in monitor)\n", 4233 QEMU_ARCH_ALL) 4234SRST 4235``-loadvm file`` 4236 Start right away with a saved state (``loadvm`` in monitor) 4237ERST 4238 4239#ifndef _WIN32 4240DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 4241 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 4242#endif 4243SRST 4244``-daemonize`` 4245 Daemonize the QEMU process after initialization. QEMU will not 4246 detach from standard IO until it is ready to receive connections on 4247 any of its devices. This option is a useful way for external 4248 programs to launch QEMU without having to cope with initialization 4249 race conditions. 4250ERST 4251 4252DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 4253 "-option-rom rom load a file, rom, into the option ROM space\n", 4254 QEMU_ARCH_ALL) 4255SRST 4256``-option-rom file`` 4257 Load the contents of file as an option ROM. This option is useful to 4258 load things like EtherBoot. 4259ERST 4260 4261DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 4262 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 4263 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 4264 QEMU_ARCH_ALL) 4265 4266SRST 4267``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]`` 4268 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at 4269 the current UTC or local time, respectively. ``localtime`` is 4270 required for correct date in MS-DOS or Windows. To start at a 4271 specific point in time, provide datetime in the format 4272 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC. 4273 4274 By default the RTC is driven by the host system time. This allows 4275 using of the RTC as accurate reference clock inside the guest, 4276 specifically if the host time is smoothly following an accurate 4277 external reference clock, e.g. via NTP. If you want to isolate the 4278 guest time from the host, you can set ``clock`` to ``rt`` instead, 4279 which provides a host monotonic clock if host support it. To even 4280 prevent the RTC from progressing during suspension, you can set 4281 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is 4282 recommended especially in icount mode in order to preserve 4283 determinism; however, note that in icount mode the speed of the 4284 virtual clock is variable and can in general differ from the host 4285 clock. 4286 4287 Enable ``driftfix`` (i386 targets only) if you experience time drift 4288 problems, specifically with Windows' ACPI HAL. This option will try 4289 to figure out how many timer interrupts were not processed by the 4290 Windows guest and will re-inject them. 4291ERST 4292 4293DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 4294 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \ 4295 " enable virtual instruction counter with 2^N clock ticks per\n" \ 4296 " instruction, enable aligning the host and virtual clocks\n" \ 4297 " or disable real time cpu sleeping, and optionally enable\n" \ 4298 " record-and-replay mode\n", QEMU_ARCH_ALL) 4299SRST 4300``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]`` 4301 Enable virtual instruction counter. The virtual cpu will execute one 4302 instruction every 2^N ns of virtual time. If ``auto`` is specified 4303 then the virtual cpu speed will be automatically adjusted to keep 4304 virtual time within a few seconds of real time. 4305 4306 Note that while this option can give deterministic behavior, it does 4307 not provide cycle accurate emulation. Modern CPUs contain 4308 superscalar out of order cores with complex cache hierarchies. The 4309 number of instructions executed often has little or no correlation 4310 with actual performance. 4311 4312 When the virtual cpu is sleeping, the virtual time will advance at 4313 default speed unless ``sleep=on`` is specified. With 4314 ``sleep=on``, the virtual time will jump to the next timer 4315 deadline instantly whenever the virtual cpu goes to sleep mode and 4316 will not advance if no timer is enabled. This behavior gives 4317 deterministic execution times from the guest point of view. 4318 The default if icount is enabled is ``sleep=off``. 4319 ``sleep=on`` cannot be used together with either ``shift=auto`` 4320 or ``align=on``. 4321 4322 ``align=on`` will activate the delay algorithm which will try to 4323 synchronise the host clock and the virtual clock. The goal is to 4324 have a guest running at the real frequency imposed by the shift 4325 option. Whenever the guest clock is behind the host clock and if 4326 ``align=on`` is specified then we print a message to the user to 4327 inform about the delay. Currently this option does not work when 4328 ``shift`` is ``auto``. Note: The sync algorithm will work for those 4329 shift values for which the guest clock runs ahead of the host clock. 4330 Typically this happens when the shift value is high (how high 4331 depends on the host machine). The default if icount is enabled 4332 is ``align=off``. 4333 4334 When the ``rr`` option is specified deterministic record/replay is 4335 enabled. The ``rrfile=`` option must also be provided to 4336 specify the path to the replay log. In record mode data is written 4337 to this file, and in replay mode it is read back. 4338 If the ``rrsnapshot`` option is given then it specifies a VM snapshot 4339 name. In record mode, a new VM snapshot with the given name is created 4340 at the start of execution recording. In replay mode this option 4341 specifies the snapshot name used to load the initial VM state. 4342ERST 4343 4344DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 4345 "-watchdog model\n" \ 4346 " enable virtual hardware watchdog [default=none]\n", 4347 QEMU_ARCH_ALL) 4348SRST 4349``-watchdog model`` 4350 Create a virtual hardware watchdog device. Once enabled (by a guest 4351 action), the watchdog must be periodically polled by an agent inside 4352 the guest or else the guest will be restarted. Choose a model for 4353 which your guest has drivers. 4354 4355 The model is the model of hardware watchdog to emulate. Use 4356 ``-watchdog help`` to list available hardware models. Only one 4357 watchdog can be enabled for a guest. 4358 4359 The following models may be available: 4360 4361 ``ib700`` 4362 iBASE 700 is a very simple ISA watchdog with a single timer. 4363 4364 ``i6300esb`` 4365 Intel 6300ESB I/O controller hub is a much more featureful 4366 PCI-based dual-timer watchdog. 4367 4368 ``diag288`` 4369 A virtual watchdog for s390x backed by the diagnose 288 4370 hypercall (currently KVM only). 4371ERST 4372 4373DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 4374 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 4375 " action when watchdog fires [default=reset]\n", 4376 QEMU_ARCH_ALL) 4377SRST 4378``-watchdog-action action`` 4379 The action controls what QEMU will do when the watchdog timer 4380 expires. The default is ``reset`` (forcefully reset the guest). 4381 Other possible actions are: ``shutdown`` (attempt to gracefully 4382 shutdown the guest), ``poweroff`` (forcefully poweroff the guest), 4383 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the 4384 guest), ``debug`` (print a debug message and continue), or ``none`` 4385 (do nothing). 4386 4387 Note that the ``shutdown`` action requires that the guest responds 4388 to ACPI signals, which it may not be able to do in the sort of 4389 situations where the watchdog would have expired, and thus 4390 ``-watchdog-action shutdown`` is not recommended for production use. 4391 4392 Examples: 4393 4394 ``-watchdog i6300esb -watchdog-action pause``; \ ``-watchdog ib700`` 4395 4396ERST 4397 4398DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 4399 "-echr chr set terminal escape character instead of ctrl-a\n", 4400 QEMU_ARCH_ALL) 4401SRST 4402``-echr numeric_ascii_value`` 4403 Change the escape character used for switching to the monitor when 4404 using monitor and serial sharing. The default is ``0x01`` when using 4405 the ``-nographic`` option. ``0x01`` is equal to pressing 4406 ``Control-a``. You can select a different character from the ascii 4407 control keys where 1 through 26 map to Control-a through Control-z. 4408 For instance you could use the either of the following to change the 4409 escape character to Control-t. 4410 4411 ``-echr 0x14``; \ ``-echr 20`` 4412 4413ERST 4414 4415DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4416 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \ 4417 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \ 4418 "-incoming unix:socketpath\n" \ 4419 " prepare for incoming migration, listen on\n" \ 4420 " specified protocol and socket address\n" \ 4421 "-incoming fd:fd\n" \ 4422 "-incoming exec:cmdline\n" \ 4423 " accept incoming migration on given file descriptor\n" \ 4424 " or from given external command\n" \ 4425 "-incoming defer\n" \ 4426 " wait for the URI to be specified via migrate_incoming\n", 4427 QEMU_ARCH_ALL) 4428SRST 4429``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]`` 4430 \ 4431``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]`` 4432 Prepare for incoming migration, listen on a given tcp port. 4433 4434``-incoming unix:socketpath`` 4435 Prepare for incoming migration, listen on a given unix socket. 4436 4437``-incoming fd:fd`` 4438 Accept incoming migration from a given filedescriptor. 4439 4440``-incoming exec:cmdline`` 4441 Accept incoming migration as an output from specified external 4442 command. 4443 4444``-incoming defer`` 4445 Wait for the URI to be specified via migrate\_incoming. The monitor 4446 can be used to change settings (such as migration parameters) prior 4447 to issuing the migrate\_incoming to allow the migration to begin. 4448ERST 4449 4450DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4451 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4452SRST 4453``-only-migratable`` 4454 Only allow migratable devices. Devices will not be allowed to enter 4455 an unmigratable state. 4456ERST 4457 4458DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4459 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4460SRST 4461``-nodefaults`` 4462 Don't create default devices. Normally, QEMU sets the default 4463 devices like serial port, parallel port, virtual console, monitor 4464 device, VGA adapter, floppy and CD-ROM drive and others. The 4465 ``-nodefaults`` option will disable all those default devices. 4466ERST 4467 4468#ifndef _WIN32 4469DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4470 "-chroot dir chroot to dir just before starting the VM\n", 4471 QEMU_ARCH_ALL) 4472#endif 4473SRST 4474``-chroot dir`` 4475 Immediately before starting guest execution, chroot to the specified 4476 directory. Especially useful in combination with -runas. 4477ERST 4478 4479#ifndef _WIN32 4480DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4481 "-runas user change to user id user just before starting the VM\n" \ 4482 " user can be numeric uid:gid instead\n", 4483 QEMU_ARCH_ALL) 4484#endif 4485SRST 4486``-runas user`` 4487 Immediately before starting guest execution, drop root privileges, 4488 switching to the specified user. 4489ERST 4490 4491DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4492 "-prom-env variable=value\n" 4493 " set OpenBIOS nvram variables\n", 4494 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4495SRST 4496``-prom-env variable=value`` 4497 Set OpenBIOS nvram variable to given value (PPC, SPARC only). 4498 4499 :: 4500 4501 qemu-system-sparc -prom-env 'auto-boot?=false' \ 4502 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' 4503 4504 :: 4505 4506 qemu-system-ppc -prom-env 'auto-boot?=false' \ 4507 -prom-env 'boot-device=hd:2,\yaboot' \ 4508 -prom-env 'boot-args=conf=hd:2,\yaboot.conf' 4509ERST 4510DEF("semihosting", 0, QEMU_OPTION_semihosting, 4511 "-semihosting semihosting mode\n", 4512 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4513 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4514SRST 4515``-semihosting`` 4516 Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V only). 4517 4518 Note that this allows guest direct access to the host filesystem, so 4519 should only be used with a trusted guest OS. 4520 4521 See the -semihosting-config option documentation for further 4522 information about the facilities this enables. 4523ERST 4524DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4525 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4526 " semihosting configuration\n", 4527QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4528QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4529SRST 4530``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]`` 4531 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V 4532 only). 4533 4534 Note that this allows guest direct access to the host filesystem, so 4535 should only be used with a trusted guest OS. 4536 4537 On Arm this implements the standard semihosting API, version 2.0. 4538 4539 On M68K this implements the "ColdFire GDB" interface used by 4540 libgloss. 4541 4542 Xtensa semihosting provides basic file IO calls, such as 4543 open/read/write/seek/select. Tensilica baremetal libc for ISS and 4544 linux platform "sim" use this interface. 4545 4546 On RISC-V this implements the standard semihosting API, version 0.2. 4547 4548 ``target=native|gdb|auto`` 4549 Defines where the semihosting calls will be addressed, to QEMU 4550 (``native``) or to GDB (``gdb``). The default is ``auto``, which 4551 means ``gdb`` during debug sessions and ``native`` otherwise. 4552 4553 ``chardev=str1`` 4554 Send the output to a chardev backend output for native or auto 4555 output when not in gdb 4556 4557 ``arg=str1,arg=str2,...`` 4558 Allows the user to pass input arguments, and can be used 4559 multiple times to build up a list. The old-style 4560 ``-kernel``/``-append`` method of passing a command line is 4561 still supported for backward compatibility. If both the 4562 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are 4563 specified, the former is passed to semihosting as it always 4564 takes precedence. 4565ERST 4566DEF("old-param", 0, QEMU_OPTION_old_param, 4567 "-old-param old param mode\n", QEMU_ARCH_ARM) 4568SRST 4569``-old-param`` 4570 Old param mode (ARM only). 4571ERST 4572 4573DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4574 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4575 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4576 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4577 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4578 " by the kernel, but typically no longer used by modern\n" \ 4579 " C library implementations.\n" \ 4580 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \ 4581 " to elevate privileges using set*uid|gid system calls.\n" \ 4582 " The value 'children' will deny set*uid|gid system calls for\n" \ 4583 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4584 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4585 " blocking *fork and execve\n" \ 4586 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4587 QEMU_ARCH_ALL) 4588SRST 4589``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]`` 4590 Enable Seccomp mode 2 system call filter. 'on' will enable syscall 4591 filtering and 'off' will disable it. The default is 'off'. 4592 4593 ``obsolete=string`` 4594 Enable Obsolete system calls 4595 4596 ``elevateprivileges=string`` 4597 Disable set\*uid\|gid system calls 4598 4599 ``spawn=string`` 4600 Disable \*fork and execve 4601 4602 ``resourcecontrol=string`` 4603 Disable process affinity and schedular priority 4604ERST 4605 4606DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4607 "-readconfig <file>\n", QEMU_ARCH_ALL) 4608SRST 4609``-readconfig file`` 4610 Read device configuration from file. This approach is useful when 4611 you want to spawn QEMU process with many command line options but 4612 you don't want to exceed the command line character limit. 4613ERST 4614DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4615 "-writeconfig <file>\n" 4616 " read/write config file (deprecated)\n", QEMU_ARCH_ALL) 4617SRST 4618ERST 4619 4620DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4621 "-no-user-config\n" 4622 " do not load default user-provided config files at startup\n", 4623 QEMU_ARCH_ALL) 4624SRST 4625``-no-user-config`` 4626 The ``-no-user-config`` option makes QEMU not load any of the 4627 user-provided config files on sysconfdir. 4628ERST 4629 4630DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4631 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4632 " specify tracing options\n", 4633 QEMU_ARCH_ALL) 4634SRST 4635``-trace [[enable=]pattern][,events=file][,file=file]`` 4636 .. include:: ../qemu-option-trace.rst.inc 4637 4638ERST 4639DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4640 "-plugin [file=]<file>[,<argname>=<argvalue>]\n" 4641 " load a plugin\n", 4642 QEMU_ARCH_ALL) 4643SRST 4644``-plugin file=file[,argname=argvalue]`` 4645 Load a plugin. 4646 4647 ``file=file`` 4648 Load the given plugin from a shared library file. 4649 4650 ``argname=argvalue`` 4651 Argument passed to the plugin. (Can be given multiple times.) 4652ERST 4653 4654HXCOMM Internal use 4655DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4656DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4657 4658#ifdef __linux__ 4659DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4660 "-enable-fips enable FIPS 140-2 compliance\n", 4661 QEMU_ARCH_ALL) 4662#endif 4663SRST 4664``-enable-fips`` 4665 Enable FIPS 140-2 compliance mode. 4666ERST 4667 4668DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4669 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n" 4670 " control error message format\n" 4671 " timestamp=on enables timestamps (default: off)\n" 4672 " guest-name=on enables guest name prefix but only if\n" 4673 " -name guest option is set (default: off)\n", 4674 QEMU_ARCH_ALL) 4675SRST 4676``-msg [timestamp[=on|off]][,guest-name[=on|off]]`` 4677 Control error message format. 4678 4679 ``timestamp=on|off`` 4680 Prefix messages with a timestamp. Default is off. 4681 4682 ``guest-name=on|off`` 4683 Prefix messages with guest name but only if -name guest option is set 4684 otherwise the option is ignored. Default is off. 4685ERST 4686 4687DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4688 "-dump-vmstate <file>\n" 4689 " Output vmstate information in JSON format to file.\n" 4690 " Use the scripts/vmstate-static-checker.py file to\n" 4691 " check for possible regressions in migration code\n" 4692 " by comparing two such vmstate dumps.\n", 4693 QEMU_ARCH_ALL) 4694SRST 4695``-dump-vmstate file`` 4696 Dump json-encoded vmstate information for current machine type to 4697 file in file 4698ERST 4699 4700DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4701 "-enable-sync-profile\n" 4702 " enable synchronization profiling\n", 4703 QEMU_ARCH_ALL) 4704SRST 4705``-enable-sync-profile`` 4706 Enable synchronization profiling. 4707ERST 4708 4709DEFHEADING() 4710 4711DEFHEADING(Generic object creation:) 4712 4713DEF("object", HAS_ARG, QEMU_OPTION_object, 4714 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4715 " create a new object of type TYPENAME setting properties\n" 4716 " in the order they are specified. Note that the 'id'\n" 4717 " property must be set. These objects are placed in the\n" 4718 " '/objects' path.\n", 4719 QEMU_ARCH_ALL) 4720SRST 4721``-object typename[,prop1=value1,...]`` 4722 Create a new object of type typename setting properties in the order 4723 they are specified. Note that the 'id' property must be set. These 4724 objects are placed in the '/objects' path. 4725 4726 ``-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`` 4727 Creates a memory file backend object, which can be used to back 4728 the guest RAM with huge pages. 4729 4730 The ``id`` parameter is a unique ID that will be used to 4731 reference this memory region in other parameters, e.g. ``-numa``, 4732 ``-device nvdimm``, etc. 4733 4734 The ``size`` option provides the size of the memory region, and 4735 accepts common suffixes, e.g. ``500M``. 4736 4737 The ``mem-path`` provides the path to either a shared memory or 4738 huge page filesystem mount. 4739 4740 The ``share`` boolean option determines whether the memory 4741 region is marked as private to QEMU, or shared. The latter 4742 allows a co-operating external process to access the QEMU memory 4743 region. 4744 4745 The ``share`` is also required for pvrdma devices due to 4746 limitations in the RDMA API provided by Linux. 4747 4748 Setting share=on might affect the ability to configure NUMA 4749 bindings for the memory backend under some circumstances, see 4750 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel 4751 source tree for additional details. 4752 4753 Setting the ``discard-data`` boolean option to on indicates that 4754 file contents can be destroyed when QEMU exits, to avoid 4755 unnecessarily flushing data to the backing file. Note that 4756 ``discard-data`` is only an optimization, and QEMU might not 4757 discard file contents if it aborts unexpectedly or is terminated 4758 using SIGKILL. 4759 4760 The ``merge`` boolean option enables memory merge, also known as 4761 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider 4762 the pages for memory deduplication. 4763 4764 Setting the ``dump`` boolean option to off excludes the memory 4765 from core dumps. This feature is also known as MADV\_DONTDUMP. 4766 4767 The ``prealloc`` boolean option enables memory preallocation. 4768 4769 The ``host-nodes`` option binds the memory range to a list of 4770 NUMA host nodes. 4771 4772 The ``policy`` option sets the NUMA policy to one of the 4773 following values: 4774 4775 ``default`` 4776 default host policy 4777 4778 ``preferred`` 4779 prefer the given host node list for allocation 4780 4781 ``bind`` 4782 restrict memory allocation to the given host node list 4783 4784 ``interleave`` 4785 interleave memory allocations across the given host node 4786 list 4787 4788 The ``align`` option specifies the base address alignment when 4789 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg 4790 ``2M``. Some backend store specified by ``mem-path`` requires an 4791 alignment different than the default one used by QEMU, eg the 4792 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4793 such cases, users can specify the required alignment via this 4794 option. 4795 4796 The ``pmem`` option specifies whether the backing file specified 4797 by ``mem-path`` is in host persistent memory that can be 4798 accessed using the SNIA NVM programming model (e.g. Intel 4799 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary 4800 operations to guarantee the persistence of its own writes to 4801 ``mem-path`` (e.g. in vNVDIMM label emulation and live 4802 migration). Also, we will map the backend-file with MAP\_SYNC 4803 flag, which ensures the file metadata is in sync for 4804 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC 4805 requires support from both the host kernel (since Linux kernel 4806 4.15) and the filesystem of ``mem-path`` mounted with DAX 4807 option. 4808 4809 The ``readonly`` option specifies whether the backing file is opened 4810 read-only or read-write (default). 4811 4812 ``-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`` 4813 Creates a memory backend object, which can be used to back the 4814 guest RAM. Memory backend objects offer more control than the 4815 ``-m`` option that is traditionally used to define guest RAM. 4816 Please refer to ``memory-backend-file`` for a description of the 4817 options. 4818 4819 ``-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`` 4820 Creates an anonymous memory file backend object, which allows 4821 QEMU to share the memory with an external process (e.g. when 4822 using vhost-user). The memory is allocated with memfd and 4823 optional sealing. (Linux only) 4824 4825 The ``seal`` option creates a sealed-file, that will block 4826 further resizing the memory ('on' by default). 4827 4828 The ``hugetlb`` option specify the file to be created resides in 4829 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction 4830 with the ``hugetlb`` option, the ``hugetlbsize`` option specify 4831 the hugetlb page size on systems that support multiple hugetlb 4832 page sizes (it must be a power of 2 value supported by the 4833 system). 4834 4835 In some versions of Linux, the ``hugetlb`` option is 4836 incompatible with the ``seal`` option (requires at least Linux 4837 4.16). 4838 4839 Please refer to ``memory-backend-file`` for a description of the 4840 other options. 4841 4842 The ``share`` boolean option is on by default with memfd. 4843 4844 ``-object rng-builtin,id=id`` 4845 Creates a random number generator backend which obtains entropy 4846 from QEMU builtin functions. The ``id`` parameter is a unique ID 4847 that will be used to reference this entropy backend from the 4848 ``virtio-rng`` device. By default, the ``virtio-rng`` device 4849 uses this RNG backend. 4850 4851 ``-object rng-random,id=id,filename=/dev/random`` 4852 Creates a random number generator backend which obtains entropy 4853 from a device on the host. The ``id`` parameter is a unique ID 4854 that will be used to reference this entropy backend from the 4855 ``virtio-rng`` device. The ``filename`` parameter specifies 4856 which file to obtain entropy from and if omitted defaults to 4857 ``/dev/urandom``. 4858 4859 ``-object rng-egd,id=id,chardev=chardevid`` 4860 Creates a random number generator backend which obtains entropy 4861 from an external daemon running on the host. The ``id`` 4862 parameter is a unique ID that will be used to reference this 4863 entropy backend from the ``virtio-rng`` device. The ``chardev`` 4864 parameter is the unique ID of a character device backend that 4865 provides the connection to the RNG daemon. 4866 4867 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off`` 4868 Creates a TLS anonymous credentials object, which can be used to 4869 provide TLS support on network backends. The ``id`` parameter is 4870 a unique ID which network backends will use to access the 4871 credentials. The ``endpoint`` is either ``server`` or ``client`` 4872 depending on whether the QEMU network backend that uses the 4873 credentials will be acting as a client or as a server. If 4874 ``verify-peer`` is enabled (the default) then once the handshake 4875 is completed, the peer credentials will be verified, though this 4876 is a no-op for anonymous credentials. 4877 4878 The dir parameter tells QEMU where to find the credential files. 4879 For server endpoints, this directory may contain a file 4880 dh-params.pem providing diffie-hellman parameters to use for the 4881 TLS server. If the file is missing, QEMU will generate a set of 4882 DH parameters at startup. This is a computationally expensive 4883 operation that consumes random pool entropy, so it is 4884 recommended that a persistent set of parameters be generated 4885 upfront and saved. 4886 4887 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]`` 4888 Creates a TLS Pre-Shared Keys (PSK) credentials object, which 4889 can be used to provide TLS support on network backends. The 4890 ``id`` parameter is a unique ID which network backends will use 4891 to access the credentials. The ``endpoint`` is either ``server`` 4892 or ``client`` depending on whether the QEMU network backend that 4893 uses the credentials will be acting as a client or as a server. 4894 For clients only, ``username`` is the username which will be 4895 sent to the server. If omitted it defaults to "qemu". 4896 4897 The dir parameter tells QEMU where to find the keys file. It is 4898 called "dir/keys.psk" and contains "username:key" pairs. This 4899 file can most easily be created using the GnuTLS ``psktool`` 4900 program. 4901 4902 For server endpoints, dir may also contain a file dh-params.pem 4903 providing diffie-hellman parameters to use for the TLS server. 4904 If the file is missing, QEMU will generate a set of DH 4905 parameters at startup. This is a computationally expensive 4906 operation that consumes random pool entropy, so it is 4907 recommended that a persistent set of parameters be generated up 4908 front and saved. 4909 4910 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id`` 4911 Creates a TLS anonymous credentials object, which can be used to 4912 provide TLS support on network backends. The ``id`` parameter is 4913 a unique ID which network backends will use to access the 4914 credentials. The ``endpoint`` is either ``server`` or ``client`` 4915 depending on whether the QEMU network backend that uses the 4916 credentials will be acting as a client or as a server. If 4917 ``verify-peer`` is enabled (the default) then once the handshake 4918 is completed, the peer credentials will be verified. With x509 4919 certificates, this implies that the clients must be provided 4920 with valid client certificates too. 4921 4922 The dir parameter tells QEMU where to find the credential files. 4923 For server endpoints, this directory may contain a file 4924 dh-params.pem providing diffie-hellman parameters to use for the 4925 TLS server. If the file is missing, QEMU will generate a set of 4926 DH parameters at startup. This is a computationally expensive 4927 operation that consumes random pool entropy, so it is 4928 recommended that a persistent set of parameters be generated 4929 upfront and saved. 4930 4931 For x509 certificate credentials the directory will contain 4932 further files providing the x509 certificates. The certificates 4933 must be stored in PEM format, in filenames ca-cert.pem, 4934 ca-crl.pem (optional), server-cert.pem (only servers), 4935 server-key.pem (only servers), client-cert.pem (only clients), 4936 and client-key.pem (only clients). 4937 4938 For the server-key.pem and client-key.pem files which contain 4939 sensitive private keys, it is possible to use an encrypted 4940 version by providing the passwordid parameter. This provides the 4941 ID of a previously created ``secret`` object containing the 4942 password for decryption. 4943 4944 The priority parameter allows to override the global default 4945 priority used by gnutls. This can be useful if the system 4946 administrator needs to use a weaker set of crypto priorities for 4947 QEMU without potentially forcing the weakness onto all 4948 applications. Or conversely if one wants wants a stronger 4949 default for QEMU than for all other applications, they can do 4950 this through this parameter. Its format is a gnutls priority 4951 string as described at 4952 https://gnutls.org/manual/html_node/Priority-Strings.html. 4953 4954 ``-object tls-cipher-suites,id=id,priority=priority`` 4955 Creates a TLS cipher suites object, which can be used to control 4956 the TLS cipher/protocol algorithms that applications are permitted 4957 to use. 4958 4959 The ``id`` parameter is a unique ID which frontends will use to 4960 access the ordered list of permitted TLS cipher suites from the 4961 host. 4962 4963 The ``priority`` parameter allows to override the global default 4964 priority used by gnutls. This can be useful if the system 4965 administrator needs to use a weaker set of crypto priorities for 4966 QEMU without potentially forcing the weakness onto all 4967 applications. Or conversely if one wants wants a stronger 4968 default for QEMU than for all other applications, they can do 4969 this through this parameter. Its format is a gnutls priority 4970 string as described at 4971 https://gnutls.org/manual/html_node/Priority-Strings.html. 4972 4973 An example of use of this object is to control UEFI HTTPS Boot. 4974 The tls-cipher-suites object exposes the ordered list of permitted 4975 TLS cipher suites from the host side to the guest firmware, via 4976 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER 4977 objects. The firmware uses the IANA_TLS_CIPHER array for configuring 4978 guest-side TLS. 4979 4980 In the following example, the priority at which the host-side policy 4981 is retrieved is given by the ``priority`` property. 4982 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to 4983 refer to /etc/crypto-policies/back-ends/gnutls.config. 4984 4985 .. parsed-literal:: 4986 4987 # |qemu_system| \\ 4988 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\ 4989 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 4990 4991 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` 4992 Interval t can't be 0, this filter batches the packet delivery: 4993 all packets arriving in a given interval on netdev netdevid are 4994 delayed until the end of the interval. Interval is in 4995 microseconds. ``status`` is optional that indicate whether the 4996 netfilter is on (enabled) or off (disabled), the default status 4997 for netfilter will be 'on'. 4998 4999 queue all\|rx\|tx is an option that can be applied to any 5000 netfilter. 5001 5002 ``all``: the filter is attached both to the receive and the 5003 transmit queue of the netdev (default). 5004 5005 ``rx``: the filter is attached to the receive queue of the 5006 netdev, where it will receive packets sent to the netdev. 5007 5008 ``tx``: the filter is attached to the transmit queue of the 5009 netdev, where it will receive packets sent by the netdev. 5010 5011 position head\|tail\|id=<id> is an option to specify where the 5012 filter should be inserted in the filter list. It can be applied 5013 to any netfilter. 5014 5015 ``head``: the filter is inserted at the head of the filter list, 5016 before any existing filters. 5017 5018 ``tail``: the filter is inserted at the tail of the filter list, 5019 behind any existing filters (default). 5020 5021 ``id=<id>``: the filter is inserted before or behind the filter 5022 specified by <id>, see the insert option below. 5023 5024 insert behind\|before is an option to specify where to insert 5025 the new filter relative to the one specified with 5026 position=id=<id>. It can be applied to any netfilter. 5027 5028 ``before``: insert before the specified filter. 5029 5030 ``behind``: insert behind the specified filter (default). 5031 5032 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5033 filter-mirror on netdev netdevid,mirror net packet to 5034 chardevchardevid, if it has the vnet\_hdr\_support flag, 5035 filter-mirror will mirror packet with vnet\_hdr\_len. 5036 5037 ``-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]`` 5038 filter-redirector on netdev netdevid,redirect filter's net 5039 packet to chardev chardevid,and redirect indev's packet to 5040 filter.if it has the vnet\_hdr\_support flag, filter-redirector 5041 will redirect packet with vnet\_hdr\_len. Create a 5042 filter-redirector we need to differ outdev id from indev id, id 5043 can not be the same. we can just use indev or outdev, but at 5044 least one of indev or outdev need to be specified. 5045 5046 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5047 Filter-rewriter is a part of COLO project.It will rewrite tcp 5048 packet to secondary from primary to keep secondary tcp 5049 connection,and rewrite tcp packet to primary from secondary make 5050 tcp packet can be handled by client.if it has the 5051 vnet\_hdr\_support flag, we can parse packet with vnet header. 5052 5053 usage: colo secondary: -object 5054 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object 5055 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object 5056 filter-rewriter,id=rew0,netdev=hn0,queue=all 5057 5058 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]`` 5059 Dump the network traffic on netdev dev to the file specified by 5060 filename. At most len bytes (64k by default) per packet are 5061 stored. The file format is libpcap, so it can be analyzed with 5062 tools such as tcpdump or Wireshark. 5063 5064 ``-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}]`` 5065 Colo-compare gets packet from primary\_in chardevid and 5066 secondary\_in, then compare whether the payload of primary packet 5067 and secondary packet are the same. If same, it will output 5068 primary packet to out\_dev, else it will notify COLO-framework to do 5069 checkpoint and send primary packet to out\_dev. In order to 5070 improve efficiency, we need to put the task of comparison in 5071 another iothread. If it has the vnet\_hdr\_support flag, 5072 colo compare will send/recv packet with vnet\_hdr\_len. 5073 The compare\_timeout=@var{ms} determines the maximum time of the 5074 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms} 5075 is to set the period of scanning expired primary node network packets. 5076 The max\_queue\_size=@var{size} is to set the max compare queue 5077 size depend on user environment. 5078 If user want to use Xen COLO, need to add the notify\_dev to 5079 notify Xen colo-frame to do checkpoint. 5080 5081 COLO-compare must be used with the help of filter-mirror, 5082 filter-redirector and filter-rewriter. 5083 5084 :: 5085 5086 KVM COLO 5087 5088 primary: 5089 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5090 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5091 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5092 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5093 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5094 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5095 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5096 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5097 -object iothread,id=iothread1 5098 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5099 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5100 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5101 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 5102 5103 secondary: 5104 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5105 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5106 -chardev socket,id=red0,host=3.3.3.3,port=9003 5107 -chardev socket,id=red1,host=3.3.3.3,port=9004 5108 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5109 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5110 5111 5112 Xen COLO 5113 5114 primary: 5115 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5116 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5117 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5118 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5119 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5120 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5121 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5122 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5123 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off 5124 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5125 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5126 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5127 -object iothread,id=iothread1 5128 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 5129 5130 secondary: 5131 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5132 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5133 -chardev socket,id=red0,host=3.3.3.3,port=9003 5134 -chardev socket,id=red1,host=3.3.3.3,port=9004 5135 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5136 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5137 5138 If you want to know the detail of above command line, you can 5139 read the colo-compare git log. 5140 5141 ``-object cryptodev-backend-builtin,id=id[,queues=queues]`` 5142 Creates a cryptodev backend which executes crypto opreation from 5143 the QEMU cipher APIS. The id parameter is a unique ID that will 5144 be used to reference this cryptodev backend from the 5145 ``virtio-crypto`` device. The queues parameter is optional, 5146 which specify the queue number of cryptodev backend, the default 5147 of queues is 1. 5148 5149 .. parsed-literal:: 5150 5151 # |qemu_system| \\ 5152 [...] \\ 5153 -object cryptodev-backend-builtin,id=cryptodev0 \\ 5154 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5155 [...] 5156 5157 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]`` 5158 Creates a vhost-user cryptodev backend, backed by a chardev 5159 chardevid. The id parameter is a unique ID that will be used to 5160 reference this cryptodev backend from the ``virtio-crypto`` 5161 device. The chardev should be a unix domain socket backed one. 5162 The vhost-user uses a specifically defined protocol to pass 5163 vhost ioctl replacement messages to an application on the other 5164 end of the socket. The queues parameter is optional, which 5165 specify the queue number of cryptodev backend for multiqueue 5166 vhost-user, the default of queues is 1. 5167 5168 .. parsed-literal:: 5169 5170 # |qemu_system| \\ 5171 [...] \\ 5172 -chardev socket,id=chardev0,path=/path/to/socket \\ 5173 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\ 5174 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5175 [...] 5176 5177 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]`` 5178 \ 5179 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]`` 5180 Defines a secret to store a password, encryption key, or some 5181 other sensitive data. The sensitive data can either be passed 5182 directly via the data parameter, or indirectly via the file 5183 parameter. Using the data parameter is insecure unless the 5184 sensitive data is encrypted. 5185 5186 The sensitive data can be provided in raw format (the default), 5187 or base64. When encoded as JSON, the raw format only supports 5188 valid UTF-8 characters, so base64 is recommended for sending 5189 binary data. QEMU will convert from which ever format is 5190 provided to the format it needs internally. eg, an RBD password 5191 can be provided in raw format, even though it will be base64 5192 encoded when passed onto the RBD sever. 5193 5194 For added protection, it is possible to encrypt the data 5195 associated with a secret using the AES-256-CBC cipher. Use of 5196 encryption is indicated by providing the keyid and iv 5197 parameters. The keyid parameter provides the ID of a previously 5198 defined secret that contains the AES-256 decryption key. This 5199 key should be 32-bytes long and be base64 encoded. The iv 5200 parameter provides the random initialization vector used for 5201 encryption of this particular secret and should be a base64 5202 encrypted string of the 16-byte IV. 5203 5204 The simplest (insecure) usage is to provide the secret inline 5205 5206 .. parsed-literal:: 5207 5208 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw 5209 5210 The simplest secure usage is to provide the secret via a file 5211 5212 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object 5213 secret,id=sec0,file=mypasswd.txt,format=raw 5214 5215 For greater security, AES-256-CBC should be used. To illustrate 5216 usage, consider the openssl command line tool which can encrypt 5217 the data. Note that when encrypting, the plaintext must be 5218 padded to the cipher block size (32 bytes) using the standard 5219 PKCS#5/6 compatible padding algorithm. 5220 5221 First a master key needs to be created in base64 encoding: 5222 5223 :: 5224 5225 # openssl rand -base64 32 > key.b64 5226 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 5227 5228 Each secret to be encrypted needs to have a random 5229 initialization vector generated. These do not need to be kept 5230 secret 5231 5232 :: 5233 5234 # openssl rand -base64 16 > iv.b64 5235 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 5236 5237 The secret to be defined can now be encrypted, in this case 5238 we're telling openssl to base64 encode the result, but it could 5239 be left as raw bytes if desired. 5240 5241 :: 5242 5243 # SECRET=$(printf "letmein" | 5244 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 5245 5246 When launching QEMU, create a master secret pointing to 5247 ``key.b64`` and specify that to be used to decrypt the user 5248 password. Pass the contents of ``iv.b64`` to the second secret 5249 5250 .. parsed-literal:: 5251 5252 # |qemu_system| \\ 5253 -object secret,id=secmaster0,format=base64,file=key.b64 \\ 5254 -object secret,id=sec0,keyid=secmaster0,format=base64,\\ 5255 data=$SECRET,iv=$(<iv.b64) 5256 5257 ``-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]`` 5258 Create a Secure Encrypted Virtualization (SEV) guest object, 5259 which can be used to provide the guest memory encryption support 5260 on AMD processors. 5261 5262 When memory encryption is enabled, one of the physical address 5263 bit (aka the C-bit) is utilized to mark if a memory page is 5264 protected. The ``cbitpos`` is used to provide the C-bit 5265 position. The C-bit position is Host family dependent hence user 5266 must provide this value. On EPYC, the value should be 47. 5267 5268 When memory encryption is enabled, we loose certain bits in 5269 physical address space. The ``reduced-phys-bits`` is used to 5270 provide the number of bits we loose in physical address space. 5271 Similar to C-bit, the value is Host family dependent. On EPYC, 5272 the value should be 5. 5273 5274 The ``sev-device`` provides the device file to use for 5275 communicating with the SEV firmware running inside AMD Secure 5276 Processor. The default device is '/dev/sev'. If hardware 5277 supports memory encryption then /dev/sev devices are created by 5278 CCP driver. 5279 5280 The ``policy`` provides the guest policy to be enforced by the 5281 SEV firmware and restrict what configuration and operational 5282 commands can be performed on this guest by the hypervisor. The 5283 policy should be provided by the guest owner and is bound to the 5284 guest and cannot be changed throughout the lifetime of the 5285 guest. The default is 0. 5286 5287 If guest ``policy`` allows sharing the key with another SEV 5288 guest then ``handle`` can be use to provide handle of the guest 5289 from which to share the key. 5290 5291 The ``dh-cert-file`` and ``session-file`` provides the guest 5292 owner's Public Diffie-Hillman key defined in SEV spec. The PDH 5293 and session parameters are used for establishing a cryptographic 5294 session with the guest owner to negotiate keys used for 5295 attestation. The file must be encoded in base64. 5296 5297 The ``kernel-hashes`` adds the hashes of given kernel/initrd/ 5298 cmdline to a designated guest firmware page for measured Linux 5299 boot with -kernel. The default is off. (Since 6.2) 5300 5301 e.g to launch a SEV guest 5302 5303 .. parsed-literal:: 5304 5305 # |qemu_system_x86| \\ 5306 ...... \\ 5307 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \\ 5308 -machine ...,memory-encryption=sev0 \\ 5309 ..... 5310 5311 ``-object authz-simple,id=id,identity=string`` 5312 Create an authorization object that will control access to 5313 network services. 5314 5315 The ``identity`` parameter is identifies the user and its format 5316 depends on the network service that authorization object is 5317 associated with. For authorizing based on TLS x509 certificates, 5318 the identity must be the x509 distinguished name. Note that care 5319 must be taken to escape any commas in the distinguished name. 5320 5321 An example authorization object to validate a x509 distinguished 5322 name would look like: 5323 5324 .. parsed-literal:: 5325 5326 # |qemu_system| \\ 5327 ... \\ 5328 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\ 5329 ... 5330 5331 Note the use of quotes due to the x509 distinguished name 5332 containing whitespace, and escaping of ','. 5333 5334 ``-object authz-listfile,id=id,filename=path,refresh=on|off`` 5335 Create an authorization object that will control access to 5336 network services. 5337 5338 The ``filename`` parameter is the fully qualified path to a file 5339 containing the access control list rules in JSON format. 5340 5341 An example set of rules that match against SASL usernames might 5342 look like: 5343 5344 :: 5345 5346 { 5347 "rules": [ 5348 { "match": "fred", "policy": "allow", "format": "exact" }, 5349 { "match": "bob", "policy": "allow", "format": "exact" }, 5350 { "match": "danb", "policy": "deny", "format": "glob" }, 5351 { "match": "dan*", "policy": "allow", "format": "exact" }, 5352 ], 5353 "policy": "deny" 5354 } 5355 5356 When checking access the object will iterate over all the rules 5357 and the first rule to match will have its ``policy`` value 5358 returned as the result. If no rules match, then the default 5359 ``policy`` value is returned. 5360 5361 The rules can either be an exact string match, or they can use 5362 the simple UNIX glob pattern matching to allow wildcards to be 5363 used. 5364 5365 If ``refresh`` is set to true the file will be monitored and 5366 automatically reloaded whenever its content changes. 5367 5368 As with the ``authz-simple`` object, the format of the identity 5369 strings being matched depends on the network service, but is 5370 usually a TLS x509 distinguished name, or a SASL username. 5371 5372 An example authorization object to validate a SASL username 5373 would look like: 5374 5375 .. parsed-literal:: 5376 5377 # |qemu_system| \\ 5378 ... \\ 5379 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\ 5380 ... 5381 5382 ``-object authz-pam,id=id,service=string`` 5383 Create an authorization object that will control access to 5384 network services. 5385 5386 The ``service`` parameter provides the name of a PAM service to 5387 use for authorization. It requires that a file 5388 ``/etc/pam.d/service`` exist to provide the configuration for 5389 the ``account`` subsystem. 5390 5391 An example authorization object to validate a TLS x509 5392 distinguished name would look like: 5393 5394 .. parsed-literal:: 5395 5396 # |qemu_system| \\ 5397 ... \\ 5398 -object authz-pam,id=auth0,service=qemu-vnc \\ 5399 ... 5400 5401 There would then be a corresponding config file for PAM at 5402 ``/etc/pam.d/qemu-vnc`` that contains: 5403 5404 :: 5405 5406 account requisite pam_listfile.so item=user sense=allow \ 5407 file=/etc/qemu/vnc.allow 5408 5409 Finally the ``/etc/qemu/vnc.allow`` file would contain the list 5410 of x509 distingished names that are permitted access 5411 5412 :: 5413 5414 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 5415 5416 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch`` 5417 Creates a dedicated event loop thread that devices can be 5418 assigned to. This is known as an IOThread. By default device 5419 emulation happens in vCPU threads or the main event loop thread. 5420 This can become a scalability bottleneck. IOThreads allow device 5421 emulation and I/O to run on other host CPUs. 5422 5423 The ``id`` parameter is a unique ID that will be used to 5424 reference this IOThread from ``-device ...,iothread=id``. 5425 Multiple devices can be assigned to an IOThread. Note that not 5426 all devices support an ``iothread`` parameter. 5427 5428 The ``query-iothreads`` QMP command lists IOThreads and reports 5429 their thread IDs so that the user can configure host CPU 5430 pinning/affinity. 5431 5432 IOThreads use an adaptive polling algorithm to reduce event loop 5433 latency. Instead of entering a blocking system call to monitor 5434 file descriptors and then pay the cost of being woken up when an 5435 event occurs, the polling algorithm spins waiting for events for 5436 a short time. The algorithm's default parameters are suitable 5437 for many cases but can be adjusted based on knowledge of the 5438 workload and/or host device latency. 5439 5440 The ``poll-max-ns`` parameter is the maximum number of 5441 nanoseconds to busy wait for events. Polling can be disabled by 5442 setting this value to 0. 5443 5444 The ``poll-grow`` parameter is the multiplier used to increase 5445 the polling time when the algorithm detects it is missing events 5446 due to not polling long enough. 5447 5448 The ``poll-shrink`` parameter is the divisor used to decrease 5449 the polling time when the algorithm detects it is spending too 5450 long polling without encountering events. 5451 5452 The ``aio-max-batch`` parameter is the maximum number of requests 5453 in a batch for the AIO engine, 0 means that the engine will use 5454 its default. 5455 5456 The IOThread parameters can be modified at run-time using the 5457 ``qom-set`` command (where ``iothread1`` is the IOThread's 5458 ``id``): 5459 5460 :: 5461 5462 (qemu) qom-set /objects/iothread1 poll-max-ns 100000 5463ERST 5464 5465 5466HXCOMM This is the last statement. Insert new options before this line! 5467 5468#undef DEF 5469#undef DEFHEADING 5470#undef ARCHHEADING 5471
