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, 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 " cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]\n", 41 QEMU_ARCH_ALL) 42SRST 43``-machine [type=]name[,prop=value[,...]]`` 44 Select the emulated machine by name. Use ``-machine help`` to list 45 available machines. 46 47 For architectures which aim to support live migration compatibility 48 across releases, each release will introduce a new versioned machine 49 type. For example, the 2.8.0 release introduced machine types 50 "pc-i440fx-2.8" and "pc-q35-2.8" for the x86\_64/i686 architectures. 51 52 To allow live migration of guests from QEMU version 2.8.0, to QEMU 53 version 2.9.0, the 2.9.0 version must support the "pc-i440fx-2.8" 54 and "pc-q35-2.8" machines too. To allow users live migrating VMs to 55 skip multiple intermediate releases when upgrading, new releases of 56 QEMU will support machine types from many previous versions. 57 58 Supported machine properties are: 59 60 ``accel=accels1[:accels2[:...]]`` 61 This is used to enable an accelerator. Depending on the target 62 architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available. 63 By default, tcg is used. If there is more than one accelerator 64 specified, the next one is used if the previous one fails to 65 initialize. 66 67 ``vmport=on|off|auto`` 68 Enables emulation of VMWare IO port, for vmmouse etc. auto says 69 to select the value based on accel. For accel=xen the default is 70 off otherwise the default is on. 71 72 ``dump-guest-core=on|off`` 73 Include guest memory in a core dump. The default is on. 74 75 ``mem-merge=on|off`` 76 Enables or disables memory merge support. This feature, when 77 supported by the host, de-duplicates identical memory pages 78 among VMs instances (enabled by default). 79 80 ``aes-key-wrap=on|off`` 81 Enables or disables AES key wrapping support on s390-ccw hosts. 82 This feature controls whether AES wrapping keys will be created 83 to allow execution of AES cryptographic functions. The default 84 is on. 85 86 ``dea-key-wrap=on|off`` 87 Enables or disables DEA key wrapping support on s390-ccw hosts. 88 This feature controls whether DEA wrapping keys will be created 89 to allow execution of DEA cryptographic functions. The default 90 is on. 91 92 ``nvdimm=on|off`` 93 Enables or disables NVDIMM support. The default is off. 94 95 ``memory-encryption=`` 96 Memory encryption object to use. The default is none. 97 98 ``hmat=on|off`` 99 Enables or disables ACPI Heterogeneous Memory Attribute Table 100 (HMAT) support. The default is off. 101 102 ``memory-backend='id'`` 103 An alternative to legacy ``-mem-path`` and ``mem-prealloc`` options. 104 Allows to use a memory backend as main RAM. 105 106 For example: 107 :: 108 109 -object memory-backend-file,id=pc.ram,size=512M,mem-path=/hugetlbfs,prealloc=on,share=on 110 -machine memory-backend=pc.ram 111 -m 512M 112 113 Migration compatibility note: 114 115 * as backend id one shall use value of 'default-ram-id', advertised by 116 machine type (available via ``query-machines`` QMP command), if migration 117 to/from old QEMU (<5.0) is expected. 118 * for machine types 4.0 and older, user shall 119 use ``x-use-canonical-path-for-ramblock-id=off`` backend option 120 if migration to/from old QEMU (<5.0) is expected. 121 122 For example: 123 :: 124 125 -object memory-backend-ram,id=pc.ram,size=512M,x-use-canonical-path-for-ramblock-id=off 126 -machine memory-backend=pc.ram 127 -m 512M 128 129 ``cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]`` 130 Define a CXL Fixed Memory Window (CFMW). 131 132 Described in the CXL 2.0 ECN: CEDT CFMWS & QTG _DSM. 133 134 They are regions of Host Physical Addresses (HPA) on a system which 135 may be interleaved across one or more CXL host bridges. The system 136 software will assign particular devices into these windows and 137 configure the downstream Host-managed Device Memory (HDM) decoders 138 in root ports, switch ports and devices appropriately to meet the 139 interleave requirements before enabling the memory devices. 140 141 ``targets.X=target`` provides the mapping to CXL host bridges 142 which may be identified by the id provided in the -device entry. 143 Multiple entries are needed to specify all the targets when 144 the fixed memory window represents interleaved memory. X is the 145 target index from 0. 146 147 ``size=size`` sets the size of the CFMW. This must be a multiple of 148 256MiB. The region will be aligned to 256MiB but the location is 149 platform and configuration dependent. 150 151 ``interleave-granularity=granularity`` sets the granularity of 152 interleave. Default 256KiB. Only 256KiB, 512KiB, 1024KiB, 2048KiB 153 4096KiB, 8192KiB and 16384KiB granularities supported. 154 155 Example: 156 157 :: 158 159 -machine cxl-fmw.0.targets.0=cxl.0,cxl-fmw.0.targets.1=cxl.1,cxl-fmw.0.size=128G,cxl-fmw.0.interleave-granularity=512k 160ERST 161 162DEF("M", HAS_ARG, QEMU_OPTION_M, 163 " sgx-epc.0.memdev=memid,sgx-epc.0.node=numaid\n", 164 QEMU_ARCH_ALL) 165 166SRST 167``sgx-epc.0.memdev=@var{memid},sgx-epc.0.node=@var{numaid}`` 168 Define an SGX EPC section. 169ERST 170 171DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 172 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 173SRST 174``-cpu model`` 175 Select CPU model (``-cpu help`` for list and additional feature 176 selection) 177ERST 178 179DEF("accel", HAS_ARG, QEMU_OPTION_accel, 180 "-accel [accel=]accelerator[,prop[=value][,...]]\n" 181 " select accelerator (kvm, xen, hvf, nvmm, whpx or tcg; use 'help' for a list)\n" 182 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n" 183 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n" 184 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n" 185 " one-insn-per-tb=on|off (one guest instruction per TCG translation block)\n" 186 " split-wx=on|off (enable TCG split w^x mapping)\n" 187 " tb-size=n (TCG translation block cache size)\n" 188 " dirty-ring-size=n (KVM dirty ring GFN count, default 0)\n" 189 " eager-split-size=n (KVM Eager Page Split chunk size, default 0, disabled. ARM only)\n" 190 " notify-vmexit=run|internal-error|disable,notify-window=n (enable notify VM exit and set notify window, x86 only)\n" 191 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 192SRST 193``-accel name[,prop=value[,...]]`` 194 This is used to enable an accelerator. Depending on the target 195 architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available. By 196 default, tcg is used. If there is more than one accelerator 197 specified, the next one is used if the previous one fails to 198 initialize. 199 200 ``igd-passthru=on|off`` 201 When Xen is in use, this option controls whether Intel 202 integrated graphics devices can be passed through to the guest 203 (default=off) 204 205 ``kernel-irqchip=on|off|split`` 206 Controls KVM in-kernel irqchip support. The default is full 207 acceleration of the interrupt controllers. On x86, split irqchip 208 reduces the kernel attack surface, at a performance cost for 209 non-MSI interrupts. Disabling the in-kernel irqchip completely 210 is not recommended except for debugging purposes. 211 212 ``kvm-shadow-mem=size`` 213 Defines the size of the KVM shadow MMU. 214 215 ``one-insn-per-tb=on|off`` 216 Makes the TCG accelerator put only one guest instruction into 217 each translation block. This slows down emulation a lot, but 218 can be useful in some situations, such as when trying to analyse 219 the logs produced by the ``-d`` option. 220 221 ``split-wx=on|off`` 222 Controls the use of split w^x mapping for the TCG code generation 223 buffer. Some operating systems require this to be enabled, and in 224 such a case this will default on. On other operating systems, this 225 will default off, but one may enable this for testing or debugging. 226 227 ``tb-size=n`` 228 Controls the size (in MiB) of the TCG translation block cache. 229 230 ``thread=single|multi`` 231 Controls number of TCG threads. When the TCG is multi-threaded 232 there will be one thread per vCPU therefore taking advantage of 233 additional host cores. The default is to enable multi-threading 234 where both the back-end and front-ends support it and no 235 incompatible TCG features have been enabled (e.g. 236 icount/replay). 237 238 ``dirty-ring-size=n`` 239 When the KVM accelerator is used, it controls the size of the per-vCPU 240 dirty page ring buffer (number of entries for each vCPU). It should 241 be a value that is power of two, and it should be 1024 or bigger (but 242 still less than the maximum value that the kernel supports). 4096 243 could be a good initial value if you have no idea which is the best. 244 Set this value to 0 to disable the feature. By default, this feature 245 is disabled (dirty-ring-size=0). When enabled, KVM will instead 246 record dirty pages in a bitmap. 247 248 ``eager-split-size=n`` 249 KVM implements dirty page logging at the PAGE_SIZE granularity and 250 enabling dirty-logging on a huge-page requires breaking it into 251 PAGE_SIZE pages in the first place. KVM on ARM does this splitting 252 lazily by default. There are performance benefits in doing huge-page 253 split eagerly, especially in situations where TLBI costs associated 254 with break-before-make sequences are considerable and also if guest 255 workloads are read intensive. The size here specifies how many pages 256 to break at a time and needs to be a valid block size which is 257 1GB/2MB/4KB, 32MB/16KB and 512MB/64KB for 4KB/16KB/64KB PAGE_SIZE 258 respectively. Be wary of specifying a higher size as it will have an 259 impact on the memory. By default, this feature is disabled 260 (eager-split-size=0). 261 262 ``notify-vmexit=run|internal-error|disable,notify-window=n`` 263 Enables or disables notify VM exit support on x86 host and specify 264 the corresponding notify window to trigger the VM exit if enabled. 265 ``run`` option enables the feature. It does nothing and continue 266 if the exit happens. ``internal-error`` option enables the feature. 267 It raises a internal error. ``disable`` option doesn't enable the feature. 268 This feature can mitigate the CPU stuck issue due to event windows don't 269 open up for a specified of time (i.e. notify-window). 270 Default: notify-vmexit=run,notify-window=0. 271 272ERST 273 274DEF("smp", HAS_ARG, QEMU_OPTION_smp, 275 "-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]\n" 276 " set the number of initial CPUs to 'n' [default=1]\n" 277 " maxcpus= maximum number of total CPUs, including\n" 278 " offline CPUs for hotplug, etc\n" 279 " sockets= number of sockets on the machine board\n" 280 " dies= number of dies in one socket\n" 281 " clusters= number of clusters in one die\n" 282 " cores= number of cores in one cluster\n" 283 " threads= number of threads in one core\n" 284 "Note: Different machines may have different subsets of the CPU topology\n" 285 " parameters supported, so the actual meaning of the supported parameters\n" 286 " will vary accordingly. For example, for a machine type that supports a\n" 287 " three-level CPU hierarchy of sockets/cores/threads, the parameters will\n" 288 " sequentially mean as below:\n" 289 " sockets means the number of sockets on the machine board\n" 290 " cores means the number of cores in one socket\n" 291 " threads means the number of threads in one core\n" 292 " For a particular machine type board, an expected CPU topology hierarchy\n" 293 " can be defined through the supported sub-option. Unsupported parameters\n" 294 " can also be provided in addition to the sub-option, but their values\n" 295 " must be set as 1 in the purpose of correct parsing.\n", 296 QEMU_ARCH_ALL) 297SRST 298``-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]`` 299 Simulate a SMP system with '\ ``n``\ ' CPUs initially present on 300 the machine type board. On boards supporting CPU hotplug, the optional 301 '\ ``maxcpus``\ ' parameter can be set to enable further CPUs to be 302 added at runtime. When both parameters are omitted, the maximum number 303 of CPUs will be calculated from the provided topology members and the 304 initial CPU count will match the maximum number. When only one of them 305 is given then the omitted one will be set to its counterpart's value. 306 Both parameters may be specified, but the maximum number of CPUs must 307 be equal to or greater than the initial CPU count. Product of the 308 CPU topology hierarchy must be equal to the maximum number of CPUs. 309 Both parameters are subject to an upper limit that is determined by 310 the specific machine type chosen. 311 312 To control reporting of CPU topology information, values of the topology 313 parameters can be specified. Machines may only support a subset of the 314 parameters and different machines may have different subsets supported 315 which vary depending on capacity of the corresponding CPU targets. So 316 for a particular machine type board, an expected topology hierarchy can 317 be defined through the supported sub-option. Unsupported parameters can 318 also be provided in addition to the sub-option, but their values must be 319 set as 1 in the purpose of correct parsing. 320 321 Either the initial CPU count, or at least one of the topology parameters 322 must be specified. The specified parameters must be greater than zero, 323 explicit configuration like "cpus=0" is not allowed. Values for any 324 omitted parameters will be computed from those which are given. 325 326 For example, the following sub-option defines a CPU topology hierarchy 327 (2 sockets totally on the machine, 2 cores per socket, 2 threads per 328 core) for a machine that only supports sockets/cores/threads. 329 Some members of the option can be omitted but their values will be 330 automatically computed: 331 332 :: 333 334 -smp 8,sockets=2,cores=2,threads=2,maxcpus=8 335 336 The following sub-option defines a CPU topology hierarchy (2 sockets 337 totally on the machine, 2 dies per socket, 2 cores per die, 2 threads 338 per core) for PC machines which support sockets/dies/cores/threads. 339 Some members of the option can be omitted but their values will be 340 automatically computed: 341 342 :: 343 344 -smp 16,sockets=2,dies=2,cores=2,threads=2,maxcpus=16 345 346 The following sub-option defines a CPU topology hierarchy (2 sockets 347 totally on the machine, 2 clusters per socket, 2 cores per cluster, 348 2 threads per core) for ARM virt machines which support sockets/clusters 349 /cores/threads. Some members of the option can be omitted but their values 350 will be automatically computed: 351 352 :: 353 354 -smp 16,sockets=2,clusters=2,cores=2,threads=2,maxcpus=16 355 356 Historically preference was given to the coarsest topology parameters 357 when computing missing values (ie sockets preferred over cores, which 358 were preferred over threads), however, this behaviour is considered 359 liable to change. Prior to 6.2 the preference was sockets over cores 360 over threads. Since 6.2 the preference is cores over sockets over threads. 361 362 For example, the following option defines a machine board with 2 sockets 363 of 1 core before 6.2 and 1 socket of 2 cores after 6.2: 364 365 :: 366 367 -smp 2 368 369 Note: The cluster topology will only be generated in ACPI and exposed 370 to guest if it's explicitly specified in -smp. 371ERST 372 373DEF("numa", HAS_ARG, QEMU_OPTION_numa, 374 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 375 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 376 "-numa dist,src=source,dst=destination,val=distance\n" 377 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n" 378 "-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" 379 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n", 380 QEMU_ARCH_ALL) 381SRST 382``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 383 \ 384``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 385 \ 386``-numa dist,src=source,dst=destination,val=distance`` 387 \ 388``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]`` 389 \ 390``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=type[,latency=lat][,bandwidth=bw]`` 391 \ 392``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]`` 393 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA 394 distance from a source node to a destination node. Set the ACPI 395 Heterogeneous Memory Attributes for the given nodes. 396 397 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and 398 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a 399 contiguous range of CPU indexes (or a single VCPU if lastcpu is 400 omitted). A non-contiguous set of VCPUs can be represented by 401 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is 402 omitted on all nodes, VCPUs are automatically split between them. 403 404 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a 405 NUMA node: 406 407 :: 408 409 -numa node,cpus=0-2,cpus=5 410 411 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option 412 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to 413 assign CPU objects to a node using topology layout properties of 414 CPU. The set of properties is machine specific, and depends on used 415 machine type/'\ ``smp``\ ' options. It could be queried with 416 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ ' 417 property specifies node to which CPU object will be assigned, it's 418 required for node to be declared with '\ ``node``\ ' option before 419 it's used with '\ ``cpu``\ ' option. 420 421 For example: 422 423 :: 424 425 -M pc \ 426 -smp 1,sockets=2,maxcpus=2 \ 427 -numa node,nodeid=0 -numa node,nodeid=1 \ 428 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 429 430 '\ ``memdev``\ ' option assigns RAM from a given memory backend 431 device to a node. It is recommended to use '\ ``memdev``\ ' option 432 over legacy '\ ``mem``\ ' option. This is because '\ ``memdev``\ ' 433 option provides better performance and more control over the 434 backend's RAM (e.g. '\ ``prealloc``\ ' parameter of 435 '\ ``-memory-backend-ram``\ ' allows memory preallocation). 436 437 For compatibility reasons, legacy '\ ``mem``\ ' option is 438 supported in 5.0 and older machine types. Note that '\ ``mem``\ ' 439 and '\ ``memdev``\ ' are mutually exclusive. If one node uses 440 '\ ``memdev``\ ', the rest nodes have to use '\ ``memdev``\ ' 441 option, and vice versa. 442 443 Users must specify memory for all NUMA nodes by '\ ``memdev``\ ' 444 (or legacy '\ ``mem``\ ' if available). In QEMU 5.2, the support 445 for '\ ``-numa node``\ ' without memory specified was removed. 446 447 '\ ``initiator``\ ' is an additional option that points to an 448 initiator NUMA node that has best performance (the lowest latency or 449 largest bandwidth) to this NUMA node. Note that this option can be 450 set only when the machine property 'hmat' is set to 'on'. 451 452 Following example creates a machine with 2 NUMA nodes, node 0 has 453 CPU. node 1 has only memory, and its initiator is node 0. Note that 454 because node 0 has CPU, by default the initiator of node 0 is itself 455 and must be itself. 456 457 :: 458 459 -machine hmat=on \ 460 -m 2G,slots=2,maxmem=4G \ 461 -object memory-backend-ram,size=1G,id=m0 \ 462 -object memory-backend-ram,size=1G,id=m1 \ 463 -numa node,nodeid=0,memdev=m0 \ 464 -numa node,nodeid=1,memdev=m1,initiator=0 \ 465 -smp 2,sockets=2,maxcpus=2 \ 466 -numa cpu,node-id=0,socket-id=0 \ 467 -numa cpu,node-id=0,socket-id=1 468 469 source and destination are NUMA node IDs. distance is the NUMA 470 distance from source to destination. The distance from a node to 471 itself is always 10. If any pair of nodes is given a distance, then 472 all pairs must be given distances. Although, when distances are only 473 given in one direction for each pair of nodes, then the distances in 474 the opposite directions are assumed to be the same. If, however, an 475 asymmetrical pair of distances is given for even one node pair, then 476 all node pairs must be provided distance values for both directions, 477 even when they are symmetrical. When a node is unreachable from 478 another node, set the pair's distance to 255. 479 480 Note that the -``numa`` option doesn't allocate any of the specified 481 resources, it just assigns existing resources to NUMA nodes. This 482 means that one still has to use the ``-m``, ``-smp`` options to 483 allocate RAM and VCPUs respectively. 484 485 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth 486 Information between initiator and target NUMA nodes in ACPI 487 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can 488 create memory requests, usually it has one or more processors. 489 Target NUMA node contains addressable memory. 490 491 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is 492 the memory hierarchy of the target NUMA node: if hierarchy is 493 'memory', the structure represents the memory performance; if 494 hierarchy is 'first-level\|second-level\|third-level', this 495 structure represents aggregated performance of memory side caches 496 for each domain. type of 'data-type' is type of data represented by 497 this structure instance: if 'hierarchy' is 'memory', 'data-type' is 498 'access\|read\|write' latency or 'access\|read\|write' bandwidth of 499 the target memory; if 'hierarchy' is 500 'first-level\|second-level\|third-level', 'data-type' is 501 'access\|read\|write' hit latency or 'access\|read\|write' hit 502 bandwidth of the target memory side cache. 503 504 lat is latency value in nanoseconds. bw is bandwidth value, the 505 possible value and units are NUM[M\|G\|T], mean that the bandwidth 506 value are NUM byte per second (or MB/s, GB/s or TB/s depending on 507 used suffix). Note that if latency or bandwidth value is 0, means 508 the corresponding latency or bandwidth information is not provided. 509 510 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory 511 belongs. size is the size of memory side cache in bytes. level is 512 the cache level described in this structure, note that the cache 513 level 0 should not be used with '\ ``hmat-cache``\ ' option. 514 associativity is the cache associativity, the possible value is 515 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy 516 is the write policy. line is the cache Line size in bytes. 517 518 For example, the following options describe 2 NUMA nodes. Node 0 has 519 2 cpus and a ram, node 1 has only a ram. The processors in node 0 520 access memory in node 0 with access-latency 5 nanoseconds, 521 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access 522 memory in NUMA node 1 with access-latency 10 nanoseconds, 523 access-bandwidth is 100 MB/s. And for memory side cache information, 524 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB, 525 policy is write-back, the cache Line size is 8 bytes: 526 527 :: 528 529 -machine hmat=on \ 530 -m 2G \ 531 -object memory-backend-ram,size=1G,id=m0 \ 532 -object memory-backend-ram,size=1G,id=m1 \ 533 -smp 2,sockets=2,maxcpus=2 \ 534 -numa node,nodeid=0,memdev=m0 \ 535 -numa node,nodeid=1,memdev=m1,initiator=0 \ 536 -numa cpu,node-id=0,socket-id=0 \ 537 -numa cpu,node-id=0,socket-id=1 \ 538 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \ 539 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \ 540 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \ 541 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \ 542 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \ 543 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8 544ERST 545 546DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 547 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 548 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 549SRST 550``-add-fd fd=fd,set=set[,opaque=opaque]`` 551 Add a file descriptor to an fd set. Valid options are: 552 553 ``fd=fd`` 554 This option defines the file descriptor of which a duplicate is 555 added to fd set. The file descriptor cannot be stdin, stdout, or 556 stderr. 557 558 ``set=set`` 559 This option defines the ID of the fd set to add the file 560 descriptor to. 561 562 ``opaque=opaque`` 563 This option defines a free-form string that can be used to 564 describe fd. 565 566 You can open an image using pre-opened file descriptors from an fd 567 set: 568 569 .. parsed-literal:: 570 571 |qemu_system| \\ 572 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 573 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 574 -drive file=/dev/fdset/2,index=0,media=disk 575ERST 576 577DEF("set", HAS_ARG, QEMU_OPTION_set, 578 "-set group.id.arg=value\n" 579 " set <arg> parameter for item <id> of type <group>\n" 580 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 581SRST 582``-set group.id.arg=value`` 583 Set parameter arg for item id of type group 584ERST 585 586DEF("global", HAS_ARG, QEMU_OPTION_global, 587 "-global driver.property=value\n" 588 "-global driver=driver,property=property,value=value\n" 589 " set a global default for a driver property\n", 590 QEMU_ARCH_ALL) 591SRST 592``-global driver.prop=value`` 593 \ 594``-global driver=driver,property=property,value=value`` 595 Set default value of driver's property prop to value, e.g.: 596 597 .. parsed-literal:: 598 599 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img 600 601 In particular, you can use this to set driver properties for devices 602 which are created automatically by the machine model. To create a 603 device which is not created automatically and set properties on it, 604 use -``device``. 605 606 -global driver.prop=value is shorthand for -global 607 driver=driver,property=prop,value=value. The longhand syntax works 608 even when driver contains a dot. 609ERST 610 611DEF("boot", HAS_ARG, QEMU_OPTION_boot, 612 "-boot [order=drives][,once=drives][,menu=on|off]\n" 613 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 614 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 615 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 616 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 617 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 618 QEMU_ARCH_ALL) 619SRST 620``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]`` 621 Specify boot order drives as a string of drive letters. Valid drive 622 letters depend on the target architecture. The x86 PC uses: a, b 623 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p 624 (Etherboot from network adapter 1-4), hard disk boot is the default. 625 To apply a particular boot order only on the first startup, specify 626 it via ``once``. Note that the ``order`` or ``once`` parameter 627 should not be used together with the ``bootindex`` property of 628 devices, since the firmware implementations normally do not support 629 both at the same time. 630 631 Interactive boot menus/prompts can be enabled via ``menu=on`` as far 632 as firmware/BIOS supports them. The default is non-interactive boot. 633 634 A splash picture could be passed to bios, enabling user to show it 635 as logo, when option splash=sp\_name is given and menu=on, If 636 firmware/BIOS supports them. Currently Seabios for X86 system 637 support it. limitation: The splash file could be a jpeg file or a 638 BMP file in 24 BPP format(true color). The resolution should be 639 supported by the SVGA mode, so the recommended is 320x240, 640x480, 640 800x640. 641 642 A timeout could be passed to bios, guest will pause for rb\_timeout 643 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will 644 not reboot, qemu passes '-1' to bios by default. Currently Seabios 645 for X86 system support it. 646 647 Do strict boot via ``strict=on`` as far as firmware/BIOS supports 648 it. This only effects when boot priority is changed by bootindex 649 options. The default is non-strict boot. 650 651 .. parsed-literal:: 652 653 # try to boot from network first, then from hard disk 654 |qemu_system_x86| -boot order=nc 655 # boot from CD-ROM first, switch back to default order after reboot 656 |qemu_system_x86| -boot once=d 657 # boot with a splash picture for 5 seconds. 658 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000 659 660 Note: The legacy format '-boot drives' is still supported but its 661 use is discouraged as it may be removed from future versions. 662ERST 663 664DEF("m", HAS_ARG, QEMU_OPTION_m, 665 "-m [size=]megs[,slots=n,maxmem=size]\n" 666 " configure guest RAM\n" 667 " size: initial amount of guest memory\n" 668 " slots: number of hotplug slots (default: none)\n" 669 " maxmem: maximum amount of guest memory (default: none)\n" 670 " Note: Some architectures might enforce a specific granularity\n", 671 QEMU_ARCH_ALL) 672SRST 673``-m [size=]megs[,slots=n,maxmem=size]`` 674 Sets guest startup RAM size to megs megabytes. Default is 128 MiB. 675 Optionally, a suffix of "M" or "G" can be used to signify a value in 676 megabytes or gigabytes respectively. Optional pair slots, maxmem 677 could be used to set amount of hotpluggable memory slots and maximum 678 amount of memory. Note that maxmem must be aligned to the page size. 679 680 For example, the following command-line sets the guest startup RAM 681 size to 1GB, creates 3 slots to hotplug additional memory and sets 682 the maximum memory the guest can reach to 4GB: 683 684 .. parsed-literal:: 685 686 |qemu_system| -m 1G,slots=3,maxmem=4G 687 688 If slots and maxmem are not specified, memory hotplug won't be 689 enabled and the guest startup RAM will never increase. 690ERST 691 692DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 693 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 694SRST 695``-mem-path path`` 696 Allocate guest RAM from a temporarily created file in path. 697ERST 698 699DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 700 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 701 QEMU_ARCH_ALL) 702SRST 703``-mem-prealloc`` 704 Preallocate memory when using -mem-path. 705ERST 706 707DEF("k", HAS_ARG, QEMU_OPTION_k, 708 "-k language use keyboard layout (for example 'fr' for French)\n", 709 QEMU_ARCH_ALL) 710SRST 711``-k language`` 712 Use keyboard layout language (for example ``fr`` for French). This 713 option is only needed where it is not easy to get raw PC keycodes 714 (e.g. on Macs, with some X11 servers or with a VNC or curses 715 display). You don't normally need to use it on PC/Linux or 716 PC/Windows hosts. 717 718 The available layouts are: 719 720 :: 721 722 ar de-ch es fo fr-ca hu ja mk no pt-br sv 723 da en-gb et fr fr-ch is lt nl pl ru th 724 de en-us fi fr-be hr it lv nl-be pt sl tr 725 726 The default is ``en-us``. 727ERST 728 729 730DEF("audio", HAS_ARG, QEMU_OPTION_audio, 731 "-audio [driver=]driver,model=value[,prop[=value][,...]]\n" 732 " specifies the audio backend and device to use;\n" 733 " apart from 'model', options are the same as for -audiodev.\n" 734 " use '-audio model=help' to show possible devices.\n", 735 QEMU_ARCH_ALL) 736SRST 737``-audio [driver=]driver,model=value[,prop[=value][,...]]`` 738 This option is a shortcut for configuring both the guest audio 739 hardware and the host audio backend in one go. 740 The driver option is the same as with the corresponding ``-audiodev`` option below. 741 The guest hardware model can be set with ``model=modelname``. 742 743 Use ``driver=help`` to list the available drivers, 744 and ``model=help`` to list the available device types. 745 746 The following two example do exactly the same, to show how ``-audio`` 747 can be used to shorten the command line length: 748 749 .. parsed-literal:: 750 751 |qemu_system| -audiodev pa,id=pa -device sb16,audiodev=pa 752 |qemu_system| -audio pa,model=sb16 753ERST 754 755DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 756 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 757 " specifies the audio backend to use\n" 758 " Use ``-audiodev help`` to list the available drivers\n" 759 " id= identifier of the backend\n" 760 " timer-period= timer period in microseconds\n" 761 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 762 " in|out.fixed-settings= use fixed settings for host audio\n" 763 " in|out.frequency= frequency to use with fixed settings\n" 764 " in|out.channels= number of channels to use with fixed settings\n" 765 " in|out.format= sample format to use with fixed settings\n" 766 " valid values: s8, s16, s32, u8, u16, u32, f32\n" 767 " in|out.voices= number of voices to use\n" 768 " in|out.buffer-length= length of buffer in microseconds\n" 769 "-audiodev none,id=id,[,prop[=value][,...]]\n" 770 " dummy driver that discards all output\n" 771#ifdef CONFIG_AUDIO_ALSA 772 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 773 " in|out.dev= name of the audio device to use\n" 774 " in|out.period-length= length of period in microseconds\n" 775 " in|out.try-poll= attempt to use poll mode\n" 776 " threshold= threshold (in microseconds) when playback starts\n" 777#endif 778#ifdef CONFIG_AUDIO_COREAUDIO 779 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 780 " in|out.buffer-count= number of buffers\n" 781#endif 782#ifdef CONFIG_AUDIO_DSOUND 783 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 784 " latency= add extra latency to playback in microseconds\n" 785#endif 786#ifdef CONFIG_AUDIO_OSS 787 "-audiodev oss,id=id[,prop[=value][,...]]\n" 788 " in|out.dev= path of the audio device to use\n" 789 " in|out.buffer-count= number of buffers\n" 790 " in|out.try-poll= attempt to use poll mode\n" 791 " try-mmap= try using memory mapped access\n" 792 " exclusive= open device in exclusive mode\n" 793 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 794#endif 795#ifdef CONFIG_AUDIO_PA 796 "-audiodev pa,id=id[,prop[=value][,...]]\n" 797 " server= PulseAudio server address\n" 798 " in|out.name= source/sink device name\n" 799 " in|out.latency= desired latency in microseconds\n" 800#endif 801#ifdef CONFIG_AUDIO_PIPEWIRE 802 "-audiodev pipewire,id=id[,prop[=value][,...]]\n" 803 " in|out.name= source/sink device name\n" 804 " in|out.stream-name= name of pipewire stream\n" 805 " in|out.latency= desired latency in microseconds\n" 806#endif 807#ifdef CONFIG_AUDIO_SDL 808 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 809 " in|out.buffer-count= number of buffers\n" 810#endif 811#ifdef CONFIG_AUDIO_SNDIO 812 "-audiodev sndio,id=id[,prop[=value][,...]]\n" 813#endif 814#ifdef CONFIG_SPICE 815 "-audiodev spice,id=id[,prop[=value][,...]]\n" 816#endif 817#ifdef CONFIG_DBUS_DISPLAY 818 "-audiodev dbus,id=id[,prop[=value][,...]]\n" 819#endif 820 "-audiodev wav,id=id[,prop[=value][,...]]\n" 821 " path= path of wav file to record\n", 822 QEMU_ARCH_ALL) 823SRST 824``-audiodev [driver=]driver,id=id[,prop[=value][,...]]`` 825 Adds a new audio backend driver identified by id. There are global 826 and driver specific properties. Some values can be set differently 827 for input and output, they're marked with ``in|out.``. You can set 828 the input's property with ``in.prop`` and the output's property with 829 ``out.prop``. For example: 830 831 :: 832 833 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 834 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 835 836 NOTE: parameter validation is known to be incomplete, in many cases 837 specifying an invalid option causes QEMU to print an error message 838 and continue emulation without sound. 839 840 Valid global options are: 841 842 ``id=identifier`` 843 Identifies the audio backend. 844 845 ``timer-period=period`` 846 Sets the timer period used by the audio subsystem in 847 microseconds. Default is 10000 (10 ms). 848 849 ``in|out.mixing-engine=on|off`` 850 Use QEMU's mixing engine to mix all streams inside QEMU and 851 convert audio formats when not supported by the backend. When 852 off, fixed-settings must be off too. Note that disabling this 853 option means that the selected backend must support multiple 854 streams and the audio formats used by the virtual cards, 855 otherwise you'll get no sound. It's not recommended to disable 856 this option unless you want to use 5.1 or 7.1 audio, as mixing 857 engine only supports mono and stereo audio. Default is on. 858 859 ``in|out.fixed-settings=on|off`` 860 Use fixed settings for host audio. When off, it will change 861 based on how the guest opens the sound card. In this case you 862 must not specify frequency, channels or format. Default is on. 863 864 ``in|out.frequency=frequency`` 865 Specify the frequency to use when using fixed-settings. Default 866 is 44100Hz. 867 868 ``in|out.channels=channels`` 869 Specify the number of channels to use when using fixed-settings. 870 Default is 2 (stereo). 871 872 ``in|out.format=format`` 873 Specify the sample format to use when using fixed-settings. 874 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``, 875 ``u32``, ``f32``. Default is ``s16``. 876 877 ``in|out.voices=voices`` 878 Specify the number of voices to use. Default is 1. 879 880 ``in|out.buffer-length=usecs`` 881 Sets the size of the buffer in microseconds. 882 883``-audiodev none,id=id[,prop[=value][,...]]`` 884 Creates a dummy backend that discards all outputs. This backend has 885 no backend specific properties. 886 887``-audiodev alsa,id=id[,prop[=value][,...]]`` 888 Creates backend using the ALSA. This backend is only available on 889 Linux. 890 891 ALSA specific options are: 892 893 ``in|out.dev=device`` 894 Specify the ALSA device to use for input and/or output. Default 895 is ``default``. 896 897 ``in|out.period-length=usecs`` 898 Sets the period length in microseconds. 899 900 ``in|out.try-poll=on|off`` 901 Attempt to use poll mode with the device. Default is on. 902 903 ``threshold=threshold`` 904 Threshold (in microseconds) when playback starts. Default is 0. 905 906``-audiodev coreaudio,id=id[,prop[=value][,...]]`` 907 Creates a backend using Apple's Core Audio. This backend is only 908 available on Mac OS and only supports playback. 909 910 Core Audio specific options are: 911 912 ``in|out.buffer-count=count`` 913 Sets the count of the buffers. 914 915``-audiodev dsound,id=id[,prop[=value][,...]]`` 916 Creates a backend using Microsoft's DirectSound. This backend is 917 only available on Windows and only supports playback. 918 919 DirectSound specific options are: 920 921 ``latency=usecs`` 922 Add extra usecs microseconds latency to playback. Default is 923 10000 (10 ms). 924 925``-audiodev oss,id=id[,prop[=value][,...]]`` 926 Creates a backend using OSS. This backend is available on most 927 Unix-like systems. 928 929 OSS specific options are: 930 931 ``in|out.dev=device`` 932 Specify the file name of the OSS device to use. Default is 933 ``/dev/dsp``. 934 935 ``in|out.buffer-count=count`` 936 Sets the count of the buffers. 937 938 ``in|out.try-poll=on|of`` 939 Attempt to use poll mode with the device. Default is on. 940 941 ``try-mmap=on|off`` 942 Try using memory mapped device access. Default is off. 943 944 ``exclusive=on|off`` 945 Open the device in exclusive mode (vmix won't work in this 946 case). Default is off. 947 948 ``dsp-policy=policy`` 949 Sets the timing policy (between 0 and 10, where smaller number 950 means smaller latency but higher CPU usage). Use -1 to use 951 buffer sizes specified by ``buffer`` and ``buffer-count``. This 952 option is ignored if you do not have OSS 4. Default is 5. 953 954``-audiodev pa,id=id[,prop[=value][,...]]`` 955 Creates a backend using PulseAudio. This backend is available on 956 most systems. 957 958 PulseAudio specific options are: 959 960 ``server=server`` 961 Sets the PulseAudio server to connect to. 962 963 ``in|out.name=sink`` 964 Use the specified source/sink for recording/playback. 965 966 ``in|out.latency=usecs`` 967 Desired latency in microseconds. The PulseAudio server will try 968 to honor this value but actual latencies may be lower or higher. 969 970``-audiodev pipewire,id=id[,prop[=value][,...]]`` 971 Creates a backend using PipeWire. This backend is available on 972 most systems. 973 974 PipeWire specific options are: 975 976 ``in|out.latency=usecs`` 977 Desired latency in microseconds. 978 979 ``in|out.name=sink`` 980 Use the specified source/sink for recording/playback. 981 982 ``in|out.stream-name`` 983 Specify the name of pipewire stream. 984 985``-audiodev sdl,id=id[,prop[=value][,...]]`` 986 Creates a backend using SDL. This backend is available on most 987 systems, but you should use your platform's native backend if 988 possible. 989 990 SDL specific options are: 991 992 ``in|out.buffer-count=count`` 993 Sets the count of the buffers. 994 995``-audiodev sndio,id=id[,prop[=value][,...]]`` 996 Creates a backend using SNDIO. This backend is available on 997 OpenBSD and most other Unix-like systems. 998 999 Sndio specific options are: 1000 1001 ``in|out.dev=device`` 1002 Specify the sndio device to use for input and/or output. Default 1003 is ``default``. 1004 1005 ``in|out.latency=usecs`` 1006 Sets the desired period length in microseconds. 1007 1008``-audiodev spice,id=id[,prop[=value][,...]]`` 1009 Creates a backend that sends audio through SPICE. This backend 1010 requires ``-spice`` and automatically selected in that case, so 1011 usually you can ignore this option. This backend has no backend 1012 specific properties. 1013 1014``-audiodev wav,id=id[,prop[=value][,...]]`` 1015 Creates a backend that writes audio to a WAV file. 1016 1017 Backend specific options are: 1018 1019 ``path=path`` 1020 Write recorded audio into the specified file. Default is 1021 ``qemu.wav``. 1022ERST 1023 1024DEF("device", HAS_ARG, QEMU_OPTION_device, 1025 "-device driver[,prop[=value][,...]]\n" 1026 " add device (based on driver)\n" 1027 " prop=value,... sets driver properties\n" 1028 " use '-device help' to print all possible drivers\n" 1029 " use '-device driver,help' to print all possible properties\n", 1030 QEMU_ARCH_ALL) 1031SRST 1032``-device driver[,prop[=value][,...]]`` 1033 Add device driver. prop=value sets driver properties. Valid 1034 properties depend on the driver. To get help on possible drivers and 1035 properties, use ``-device help`` and ``-device driver,help``. 1036 1037 Some drivers are: 1038 1039``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]`` 1040 Add an IPMI BMC. This is a simulation of a hardware management 1041 interface processor that normally sits on a system. It provides a 1042 watchdog and the ability to reset and power control the system. You 1043 need to connect this to an IPMI interface to make it useful 1044 1045 The IPMI slave address to use for the BMC. The default is 0x20. This 1046 address is the BMC's address on the I2C network of management 1047 controllers. If you don't know what this means, it is safe to ignore 1048 it. 1049 1050 ``id=id`` 1051 The BMC id for interfaces to use this device. 1052 1053 ``slave_addr=val`` 1054 Define slave address to use for the BMC. The default is 0x20. 1055 1056 ``sdrfile=file`` 1057 file containing raw Sensor Data Records (SDR) data. The default 1058 is none. 1059 1060 ``fruareasize=val`` 1061 size of a Field Replaceable Unit (FRU) area. The default is 1062 1024. 1063 1064 ``frudatafile=file`` 1065 file containing raw Field Replaceable Unit (FRU) inventory data. 1066 The default is none. 1067 1068 ``guid=uuid`` 1069 value for the GUID for the BMC, in standard UUID format. If this 1070 is set, get "Get GUID" command to the BMC will return it. 1071 Otherwise "Get GUID" will return an error. 1072 1073``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]`` 1074 Add a connection to an external IPMI BMC simulator. Instead of 1075 locally emulating the BMC like the above item, instead connect to an 1076 external entity that provides the IPMI services. 1077 1078 A connection is made to an external BMC simulator. If you do this, 1079 it is strongly recommended that you use the "reconnect=" chardev 1080 option to reconnect to the simulator if the connection is lost. Note 1081 that if this is not used carefully, it can be a security issue, as 1082 the interface has the ability to send resets, NMIs, and power off 1083 the VM. It's best if QEMU makes a connection to an external 1084 simulator running on a secure port on localhost, so neither the 1085 simulator nor QEMU is exposed to any outside network. 1086 1087 See the "lanserv/README.vm" file in the OpenIPMI library for more 1088 details on the external interface. 1089 1090``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]`` 1091 Add a KCS IPMI interface on the ISA bus. This also adds a 1092 corresponding ACPI and SMBIOS entries, if appropriate. 1093 1094 ``bmc=id`` 1095 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern 1096 above. 1097 1098 ``ioport=val`` 1099 Define the I/O address of the interface. The default is 0xca0 1100 for KCS. 1101 1102 ``irq=val`` 1103 Define the interrupt to use. The default is 5. To disable 1104 interrupts, set this to 0. 1105 1106``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]`` 1107 Like the KCS interface, but defines a BT interface. The default port 1108 is 0xe4 and the default interrupt is 5. 1109 1110``-device pci-ipmi-kcs,bmc=id`` 1111 Add a KCS IPMI interface on the PCI bus. 1112 1113 ``bmc=id`` 1114 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 1115 1116``-device pci-ipmi-bt,bmc=id`` 1117 Like the KCS interface, but defines a BT interface on the PCI bus. 1118 1119``-device intel-iommu[,option=...]`` 1120 This is only supported by ``-machine q35``, which will enable Intel VT-d 1121 emulation within the guest. It supports below options: 1122 1123 ``intremap=on|off`` (default: auto) 1124 This enables interrupt remapping feature. It's required to enable 1125 complete x2apic. Currently it only supports kvm kernel-irqchip modes 1126 ``off`` or ``split``, while full kernel-irqchip is not yet supported. 1127 The default value is "auto", which will be decided by the mode of 1128 kernel-irqchip. 1129 1130 ``caching-mode=on|off`` (default: off) 1131 This enables caching mode for the VT-d emulated device. When 1132 caching-mode is enabled, each guest DMA buffer mapping will generate an 1133 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in 1134 a synchronous way. It is required for ``-device vfio-pci`` to work 1135 with the VT-d device, because host assigned devices requires to setup 1136 the DMA mapping on the host before guest DMA starts. 1137 1138 ``device-iotlb=on|off`` (default: off) 1139 This enables device-iotlb capability for the emulated VT-d device. So 1140 far virtio/vhost should be the only real user for this parameter, 1141 paired with ats=on configured for the device. 1142 1143 ``aw-bits=39|48`` (default: 39) 1144 This decides the address width of IOVA address space. The address 1145 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for 1146 4-level IOMMU page tables. 1147 1148 Please also refer to the wiki page for general scenarios of VT-d 1149 emulation in QEMU: https://wiki.qemu.org/Features/VT-d. 1150 1151ERST 1152 1153DEF("name", HAS_ARG, QEMU_OPTION_name, 1154 "-name string1[,process=string2][,debug-threads=on|off]\n" 1155 " set the name of the guest\n" 1156 " string1 sets the window title and string2 the process name\n" 1157 " When debug-threads is enabled, individual threads are given a separate name\n" 1158 " NOTE: The thread names are for debugging and not a stable API.\n", 1159 QEMU_ARCH_ALL) 1160SRST 1161``-name name`` 1162 Sets the name of the guest. This name will be displayed in the SDL 1163 window caption. The name will also be used for the VNC server. Also 1164 optionally set the top visible process name in Linux. Naming of 1165 individual threads can also be enabled on Linux to aid debugging. 1166ERST 1167 1168DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 1169 "-uuid %08x-%04x-%04x-%04x-%012x\n" 1170 " specify machine UUID\n", QEMU_ARCH_ALL) 1171SRST 1172``-uuid uuid`` 1173 Set system UUID. 1174ERST 1175 1176DEFHEADING() 1177 1178DEFHEADING(Block device options:) 1179 1180SRST 1181The QEMU block device handling options have a long history and 1182have gone through several iterations as the feature set and complexity 1183of the block layer have grown. Many online guides to QEMU often 1184reference older and deprecated options, which can lead to confusion. 1185 1186The most explicit way to describe disks is to use a combination of 1187``-device`` to specify the hardware device and ``-blockdev`` to 1188describe the backend. The device defines what the guest sees and the 1189backend describes how QEMU handles the data. It is the only guaranteed 1190stable interface for describing block devices and as such is 1191recommended for management tools and scripting. 1192 1193The ``-drive`` option combines the device and backend into a single 1194command line option which is a more human friendly. There is however no 1195interface stability guarantee although some older board models still 1196need updating to work with the modern blockdev forms. 1197 1198Older options like ``-hda`` are essentially macros which expand into 1199``-drive`` options for various drive interfaces. The original forms 1200bake in a lot of assumptions from the days when QEMU was emulating a 1201legacy PC, they are not recommended for modern configurations. 1202 1203ERST 1204 1205DEF("fda", HAS_ARG, QEMU_OPTION_fda, 1206 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 1207DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 1208SRST 1209``-fda file`` 1210 \ 1211``-fdb file`` 1212 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in 1213 the System Emulation Users Guide). 1214ERST 1215 1216DEF("hda", HAS_ARG, QEMU_OPTION_hda, 1217 "-hda/-hdb file use 'file' as hard disk 0/1 image\n", QEMU_ARCH_ALL) 1218DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 1219DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 1220 "-hdc/-hdd file use 'file' as hard disk 2/3 image\n", QEMU_ARCH_ALL) 1221DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 1222SRST 1223``-hda file`` 1224 \ 1225``-hdb file`` 1226 \ 1227``-hdc file`` 1228 \ 1229``-hdd file`` 1230 Use file as hard disk 0, 1, 2 or 3 image on the default bus of the 1231 emulated machine (this is for example the IDE bus on most x86 machines, 1232 but it can also be SCSI, virtio or something else on other target 1233 architectures). See also the :ref:`disk images` chapter in the System 1234 Emulation Users Guide. 1235ERST 1236 1237DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 1238 "-cdrom file use 'file' as CD-ROM image\n", 1239 QEMU_ARCH_ALL) 1240SRST 1241``-cdrom file`` 1242 Use file as CD-ROM image on the default bus of the emulated machine 1243 (which is IDE1 master on x86, so you cannot use ``-hdc`` and ``-cdrom`` 1244 at the same time there). On systems that support it, you can use the 1245 host CD-ROM by using ``/dev/cdrom`` as filename. 1246ERST 1247 1248DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 1249 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 1250 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 1251 " [,read-only=on|off][,auto-read-only=on|off]\n" 1252 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 1253 " [,driver specific parameters...]\n" 1254 " configure a block backend\n", QEMU_ARCH_ALL) 1255SRST 1256``-blockdev option[,option[,option[,...]]]`` 1257 Define a new block driver node. Some of the options apply to all 1258 block drivers, other options are only accepted for a specific block 1259 driver. See below for a list of generic options and options for the 1260 most common block drivers. 1261 1262 Options that expect a reference to another node (e.g. ``file``) can 1263 be given in two ways. Either you specify the node name of an already 1264 existing node (file=node-name), or you define a new node inline, 1265 adding options for the referenced node after a dot 1266 (file.filename=path,file.aio=native). 1267 1268 A block driver node created with ``-blockdev`` can be used for a 1269 guest device by specifying its node name for the ``drive`` property 1270 in a ``-device`` argument that defines a block device. 1271 1272 ``Valid options for any block driver node:`` 1273 ``driver`` 1274 Specifies the block driver to use for the given node. 1275 1276 ``node-name`` 1277 This defines the name of the block driver node by which it 1278 will be referenced later. The name must be unique, i.e. it 1279 must not match the name of a different block driver node, or 1280 (if you use ``-drive`` as well) the ID of a drive. 1281 1282 If no node name is specified, it is automatically generated. 1283 The generated node name is not intended to be predictable 1284 and changes between QEMU invocations. For the top level, an 1285 explicit node name must be specified. 1286 1287 ``read-only`` 1288 Open the node read-only. Guest write attempts will fail. 1289 1290 Note that some block drivers support only read-only access, 1291 either generally or in certain configurations. In this case, 1292 the default value ``read-only=off`` does not work and the 1293 option must be specified explicitly. 1294 1295 ``auto-read-only`` 1296 If ``auto-read-only=on`` is set, QEMU may fall back to 1297 read-only usage even when ``read-only=off`` is requested, or 1298 even switch between modes as needed, e.g. depending on 1299 whether the image file is writable or whether a writing user 1300 is attached to the node. 1301 1302 ``force-share`` 1303 Override the image locking system of QEMU by forcing the 1304 node to utilize weaker shared access for permissions where 1305 it would normally request exclusive access. When there is 1306 the potential for multiple instances to have the same file 1307 open (whether this invocation of QEMU is the first or the 1308 second instance), both instances must permit shared access 1309 for the second instance to succeed at opening the file. 1310 1311 Enabling ``force-share=on`` requires ``read-only=on``. 1312 1313 ``cache.direct`` 1314 The host page cache can be avoided with ``cache.direct=on``. 1315 This will attempt to do disk IO directly to the guest's 1316 memory. QEMU may still perform an internal copy of the data. 1317 1318 ``cache.no-flush`` 1319 In case you don't care about data integrity over host 1320 failures, you can use ``cache.no-flush=on``. This option 1321 tells QEMU that it never needs to write any data to the disk 1322 but can instead keep things in cache. If anything goes 1323 wrong, like your host losing power, the disk storage getting 1324 disconnected accidentally, etc. your image will most 1325 probably be rendered unusable. 1326 1327 ``discard=discard`` 1328 discard is one of "ignore" (or "off") or "unmap" (or "on") 1329 and controls whether ``discard`` (also known as ``trim`` or 1330 ``unmap``) requests are ignored or passed to the filesystem. 1331 Some machine types may not support discard requests. 1332 1333 ``detect-zeroes=detect-zeroes`` 1334 detect-zeroes is "off", "on" or "unmap" and enables the 1335 automatic conversion of plain zero writes by the OS to 1336 driver specific optimized zero write commands. You may even 1337 choose "unmap" if discard is set to "unmap" to allow a zero 1338 write to be converted to an ``unmap`` operation. 1339 1340 ``Driver-specific options for file`` 1341 This is the protocol-level block driver for accessing regular 1342 files. 1343 1344 ``filename`` 1345 The path to the image file in the local filesystem 1346 1347 ``aio`` 1348 Specifies the AIO backend (threads/native/io_uring, 1349 default: threads) 1350 1351 ``locking`` 1352 Specifies whether the image file is protected with Linux OFD 1353 / POSIX locks. The default is to use the Linux Open File 1354 Descriptor API if available, otherwise no lock is applied. 1355 (auto/on/off, default: auto) 1356 1357 Example: 1358 1359 :: 1360 1361 -blockdev driver=file,node-name=disk,filename=disk.img 1362 1363 ``Driver-specific options for raw`` 1364 This is the image format block driver for raw images. It is 1365 usually stacked on top of a protocol level block driver such as 1366 ``file``. 1367 1368 ``file`` 1369 Reference to or definition of the data source block driver 1370 node (e.g. a ``file`` driver node) 1371 1372 Example 1: 1373 1374 :: 1375 1376 -blockdev driver=file,node-name=disk_file,filename=disk.img 1377 -blockdev driver=raw,node-name=disk,file=disk_file 1378 1379 Example 2: 1380 1381 :: 1382 1383 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1384 1385 ``Driver-specific options for qcow2`` 1386 This is the image format block driver for qcow2 images. It is 1387 usually stacked on top of a protocol level block driver such as 1388 ``file``. 1389 1390 ``file`` 1391 Reference to or definition of the data source block driver 1392 node (e.g. a ``file`` driver node) 1393 1394 ``backing`` 1395 Reference to or definition of the backing file block device 1396 (default is taken from the image file). It is allowed to 1397 pass ``null`` here in order to disable the default backing 1398 file. 1399 1400 ``lazy-refcounts`` 1401 Whether to enable the lazy refcounts feature (on/off; 1402 default is taken from the image file) 1403 1404 ``cache-size`` 1405 The maximum total size of the L2 table and refcount block 1406 caches in bytes (default: the sum of l2-cache-size and 1407 refcount-cache-size) 1408 1409 ``l2-cache-size`` 1410 The maximum size of the L2 table cache in bytes (default: if 1411 cache-size is not specified - 32M on Linux platforms, and 8M 1412 on non-Linux platforms; otherwise, as large as possible 1413 within the cache-size, while permitting the requested or the 1414 minimal refcount cache size) 1415 1416 ``refcount-cache-size`` 1417 The maximum size of the refcount block cache in bytes 1418 (default: 4 times the cluster size; or if cache-size is 1419 specified, the part of it which is not used for the L2 1420 cache) 1421 1422 ``cache-clean-interval`` 1423 Clean unused entries in the L2 and refcount caches. The 1424 interval is in seconds. The default value is 600 on 1425 supporting platforms, and 0 on other platforms. Setting it 1426 to 0 disables this feature. 1427 1428 ``pass-discard-request`` 1429 Whether discard requests to the qcow2 device should be 1430 forwarded to the data source (on/off; default: on if 1431 discard=unmap is specified, off otherwise) 1432 1433 ``pass-discard-snapshot`` 1434 Whether discard requests for the data source should be 1435 issued when a snapshot operation (e.g. deleting a snapshot) 1436 frees clusters in the qcow2 file (on/off; default: on) 1437 1438 ``pass-discard-other`` 1439 Whether discard requests for the data source should be 1440 issued on other occasions where a cluster gets freed 1441 (on/off; default: off) 1442 1443 ``discard-no-unref`` 1444 When enabled, discards from the guest will not cause cluster 1445 allocations to be relinquished. This prevents qcow2 fragmentation 1446 that would be caused by such discards. Besides potential 1447 performance degradation, such fragmentation can lead to increased 1448 allocation of clusters past the end of the image file, 1449 resulting in image files whose file length can grow much larger 1450 than their guest disk size would suggest. 1451 If image file length is of concern (e.g. when storing qcow2 1452 images directly on block devices), you should consider enabling 1453 this option. 1454 1455 ``overlap-check`` 1456 Which overlap checks to perform for writes to the image 1457 (none/constant/cached/all; default: cached). For details or 1458 finer granularity control refer to the QAPI documentation of 1459 ``blockdev-add``. 1460 1461 Example 1: 1462 1463 :: 1464 1465 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1466 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1467 1468 Example 2: 1469 1470 :: 1471 1472 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1473 1474 ``Driver-specific options for other drivers`` 1475 Please refer to the QAPI documentation of the ``blockdev-add`` 1476 QMP command. 1477ERST 1478 1479DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1480 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1481 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1482 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1483 " [,werror=ignore|stop|report|enospc][,id=name]\n" 1484 " [,aio=threads|native|io_uring]\n" 1485 " [,readonly=on|off][,copy-on-read=on|off]\n" 1486 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1487 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1488 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1489 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1490 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1491 " [[,iops_size=is]]\n" 1492 " [[,group=g]]\n" 1493 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1494SRST 1495``-drive option[,option[,option[,...]]]`` 1496 Define a new drive. This includes creating a block driver node (the 1497 backend) as well as a guest device, and is mostly a shortcut for 1498 defining the corresponding ``-blockdev`` and ``-device`` options. 1499 1500 ``-drive`` accepts all options that are accepted by ``-blockdev``. 1501 In addition, it knows the following options: 1502 1503 ``file=file`` 1504 This option defines which disk image (see the :ref:`disk images` 1505 chapter in the System Emulation Users Guide) to use with this drive. 1506 If the filename contains comma, you must double it (for instance, 1507 "file=my,,file" to use file "my,file"). 1508 1509 Special files such as iSCSI devices can be specified using 1510 protocol specific URLs. See the section for "Device URL Syntax" 1511 for more information. 1512 1513 ``if=interface`` 1514 This option defines on which type on interface the drive is 1515 connected. Available types are: ide, scsi, sd, mtd, floppy, 1516 pflash, virtio, none. 1517 1518 ``bus=bus,unit=unit`` 1519 These options define where is connected the drive by defining 1520 the bus number and the unit id. 1521 1522 ``index=index`` 1523 This option defines where the drive is connected by using an 1524 index in the list of available connectors of a given interface 1525 type. 1526 1527 ``media=media`` 1528 This option defines the type of the media: disk or cdrom. 1529 1530 ``snapshot=snapshot`` 1531 snapshot is "on" or "off" and controls snapshot mode for the 1532 given drive (see ``-snapshot``). 1533 1534 ``cache=cache`` 1535 cache is "none", "writeback", "unsafe", "directsync" or 1536 "writethrough" and controls how the host cache is used to access 1537 block data. This is a shortcut that sets the ``cache.direct`` 1538 and ``cache.no-flush`` options (as in ``-blockdev``), and 1539 additionally ``cache.writeback``, which provides a default for 1540 the ``write-cache`` option of block guest devices (as in 1541 ``-device``). The modes correspond to the following settings: 1542 1543 ============= =============== ============ ============== 1544 \ cache.writeback cache.direct cache.no-flush 1545 ============= =============== ============ ============== 1546 writeback on off off 1547 none on on off 1548 writethrough off off off 1549 directsync off on off 1550 unsafe on off on 1551 ============= =============== ============ ============== 1552 1553 The default mode is ``cache=writeback``. 1554 1555 ``aio=aio`` 1556 aio is "threads", "native", or "io_uring" and selects between pthread 1557 based disk I/O, native Linux AIO, or Linux io_uring API. 1558 1559 ``format=format`` 1560 Specify which disk format will be used rather than detecting the 1561 format. Can be used to specify format=raw to avoid interpreting 1562 an untrusted format header. 1563 1564 ``werror=action,rerror=action`` 1565 Specify which action to take on write and read errors. Valid 1566 actions are: "ignore" (ignore the error and try to continue), 1567 "stop" (pause QEMU), "report" (report the error to the guest), 1568 "enospc" (pause QEMU only if the host disk is full; report the 1569 error to the guest otherwise). The default setting is 1570 ``werror=enospc`` and ``rerror=report``. 1571 1572 ``copy-on-read=copy-on-read`` 1573 copy-on-read is "on" or "off" and enables whether to copy read 1574 backing file sectors into the image file. 1575 1576 ``bps=b,bps_rd=r,bps_wr=w`` 1577 Specify bandwidth throttling limits in bytes per second, either 1578 for all request types or for reads or writes only. Small values 1579 can lead to timeouts or hangs inside the guest. A safe minimum 1580 for disks is 2 MB/s. 1581 1582 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm`` 1583 Specify bursts in bytes per second, either for all request types 1584 or for reads or writes only. Bursts allow the guest I/O to spike 1585 above the limit temporarily. 1586 1587 ``iops=i,iops_rd=r,iops_wr=w`` 1588 Specify request rate limits in requests per second, either for 1589 all request types or for reads or writes only. 1590 1591 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm`` 1592 Specify bursts in requests per second, either for all request 1593 types or for reads or writes only. Bursts allow the guest I/O to 1594 spike above the limit temporarily. 1595 1596 ``iops_size=is`` 1597 Let every is bytes of a request count as a new request for iops 1598 throttling purposes. Use this option to prevent guests from 1599 circumventing iops limits by sending fewer but larger requests. 1600 1601 ``group=g`` 1602 Join a throttling quota group with given name g. All drives that 1603 are members of the same group are accounted for together. Use 1604 this option to prevent guests from circumventing throttling 1605 limits by using many small disks instead of a single larger 1606 disk. 1607 1608 By default, the ``cache.writeback=on`` mode is used. It will report 1609 data writes as completed as soon as the data is present in the host 1610 page cache. This is safe as long as your guest OS makes sure to 1611 correctly flush disk caches where needed. If your guest OS does not 1612 handle volatile disk write caches correctly and your host crashes or 1613 loses power, then the guest may experience data corruption. 1614 1615 For such guests, you should consider using ``cache.writeback=off``. 1616 This means that the host page cache will be used to read and write 1617 data, but write notification will be sent to the guest only after 1618 QEMU has made sure to flush each write to the disk. Be aware that 1619 this has a major impact on performance. 1620 1621 When using the ``-snapshot`` option, unsafe caching is always used. 1622 1623 Copy-on-read avoids accessing the same backing file sectors 1624 repeatedly and is useful when the backing file is over a slow 1625 network. By default copy-on-read is off. 1626 1627 Instead of ``-cdrom`` you can use: 1628 1629 .. parsed-literal:: 1630 1631 |qemu_system| -drive file=file,index=2,media=cdrom 1632 1633 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use: 1634 1635 .. parsed-literal:: 1636 1637 |qemu_system| -drive file=file,index=0,media=disk 1638 |qemu_system| -drive file=file,index=1,media=disk 1639 |qemu_system| -drive file=file,index=2,media=disk 1640 |qemu_system| -drive file=file,index=3,media=disk 1641 1642 You can open an image using pre-opened file descriptors from an fd 1643 set: 1644 1645 .. parsed-literal:: 1646 1647 |qemu_system| \\ 1648 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 1649 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 1650 -drive file=/dev/fdset/2,index=0,media=disk 1651 1652 You can connect a CDROM to the slave of ide0: 1653 1654 .. parsed-literal:: 1655 1656 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom 1657 1658 If you don't specify the "file=" argument, you define an empty 1659 drive: 1660 1661 .. parsed-literal:: 1662 1663 |qemu_system_x86| -drive if=ide,index=1,media=cdrom 1664 1665 Instead of ``-fda``, ``-fdb``, you can use: 1666 1667 .. parsed-literal:: 1668 1669 |qemu_system_x86| -drive file=file,index=0,if=floppy 1670 |qemu_system_x86| -drive file=file,index=1,if=floppy 1671 1672 By default, interface is "ide" and index is automatically 1673 incremented: 1674 1675 .. parsed-literal:: 1676 1677 |qemu_system_x86| -drive file=a -drive file=b 1678 1679 is interpreted like: 1680 1681 .. parsed-literal:: 1682 1683 |qemu_system_x86| -hda a -hdb b 1684ERST 1685 1686DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1687 "-mtdblock file use 'file' as on-board Flash memory image\n", 1688 QEMU_ARCH_ALL) 1689SRST 1690``-mtdblock file`` 1691 Use file as on-board Flash memory image. 1692ERST 1693 1694DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1695 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1696SRST 1697``-sd file`` 1698 Use file as SecureDigital card image. 1699ERST 1700 1701DEF("snapshot", 0, QEMU_OPTION_snapshot, 1702 "-snapshot write to temporary files instead of disk image files\n", 1703 QEMU_ARCH_ALL) 1704SRST 1705``-snapshot`` 1706 Write to temporary files instead of disk image files. In this case, 1707 the raw disk image you use is not written back. You can however 1708 force the write back by pressing C-a s (see the :ref:`disk images` 1709 chapter in the System Emulation Users Guide). 1710 1711 .. warning:: 1712 snapshot is incompatible with ``-blockdev`` (instead use qemu-img 1713 to manually create snapshot images to attach to your blockdev). 1714 If you have mixed ``-blockdev`` and ``-drive`` declarations you 1715 can use the 'snapshot' property on your drive declarations 1716 instead of this global option. 1717 1718ERST 1719 1720DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1721 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1722 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n" 1723 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1724 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1725 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1726 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1727 " [[,throttling.iops-size=is]]\n" 1728 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly=on]\n" 1729 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly=on]\n" 1730 "-fsdev synth,id=id\n", 1731 QEMU_ARCH_ALL) 1732 1733SRST 1734``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly=on][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]`` 1735 \ 1736``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly=on]`` 1737 \ 1738``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly=on]`` 1739 \ 1740``-fsdev synth,id=id[,readonly=on]`` 1741 Define a new file system device. Valid options are: 1742 1743 ``local`` 1744 Accesses to the filesystem are done by QEMU. 1745 1746 ``proxy`` 1747 Accesses to the filesystem are done by virtfs-proxy-helper(1). This 1748 option is deprecated (since QEMU 8.1) and will be removed in a future 1749 version of QEMU. Use ``local`` instead. 1750 1751 ``synth`` 1752 Synthetic filesystem, only used by QTests. 1753 1754 ``id=id`` 1755 Specifies identifier for this device. 1756 1757 ``path=path`` 1758 Specifies the export path for the file system device. Files 1759 under this path will be available to the 9p client on the guest. 1760 1761 ``security_model=security_model`` 1762 Specifies the security model to be used for this export path. 1763 Supported security models are "passthrough", "mapped-xattr", 1764 "mapped-file" and "none". In "passthrough" security model, files 1765 are stored using the same credentials as they are created on the 1766 guest. This requires QEMU to run as root. In "mapped-xattr" 1767 security model, some of the file attributes like uid, gid, mode 1768 bits and link target are stored as file attributes. For 1769 "mapped-file" these attributes are stored in the hidden 1770 .virtfs\_metadata directory. Directories exported by this 1771 security model cannot interact with other unix tools. "none" 1772 security model is same as passthrough except the sever won't 1773 report failures if it fails to set file attributes like 1774 ownership. Security model is mandatory only for local fsdriver. 1775 Other fsdrivers (like proxy) don't take security model as a 1776 parameter. 1777 1778 ``writeout=writeout`` 1779 This is an optional argument. The only supported value is 1780 "immediate". This means that host page cache will be used to 1781 read and write data but write notification will be sent to the 1782 guest only when the data has been reported as written by the 1783 storage subsystem. 1784 1785 ``readonly=on`` 1786 Enables exporting 9p share as a readonly mount for guests. By 1787 default read-write access is given. 1788 1789 ``socket=socket`` 1790 Enables proxy filesystem driver to use passed socket file for 1791 communicating with virtfs-proxy-helper(1). 1792 1793 ``sock_fd=sock_fd`` 1794 Enables proxy filesystem driver to use passed socket descriptor 1795 for communicating with virtfs-proxy-helper(1). Usually a helper 1796 like libvirt will create socketpair and pass one of the fds as 1797 sock\_fd. 1798 1799 ``fmode=fmode`` 1800 Specifies the default mode for newly created files on the host. 1801 Works only with security models "mapped-xattr" and 1802 "mapped-file". 1803 1804 ``dmode=dmode`` 1805 Specifies the default mode for newly created directories on the 1806 host. Works only with security models "mapped-xattr" and 1807 "mapped-file". 1808 1809 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w`` 1810 Specify bandwidth throttling limits in bytes per second, either 1811 for all request types or for reads or writes only. 1812 1813 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm`` 1814 Specify bursts in bytes per second, either for all request types 1815 or for reads or writes only. Bursts allow the guest I/O to spike 1816 above the limit temporarily. 1817 1818 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w`` 1819 Specify request rate limits in requests per second, either for 1820 all request types or for reads or writes only. 1821 1822 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm`` 1823 Specify bursts in requests per second, either for all request 1824 types or for reads or writes only. Bursts allow the guest I/O to 1825 spike above the limit temporarily. 1826 1827 ``throttling.iops-size=is`` 1828 Let every is bytes of a request count as a new request for iops 1829 throttling purposes. 1830 1831 -fsdev option is used along with -device driver "virtio-9p-...". 1832 1833``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag`` 1834 Options for virtio-9p-... driver are: 1835 1836 ``type`` 1837 Specifies the variant to be used. Supported values are "pci", 1838 "ccw" or "device", depending on the machine type. 1839 1840 ``fsdev=id`` 1841 Specifies the id value specified along with -fsdev option. 1842 1843 ``mount_tag=mount_tag`` 1844 Specifies the tag name to be used by the guest to mount this 1845 export point. 1846ERST 1847 1848DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1849 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1850 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1851 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly=on]\n" 1852 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly=on]\n" 1853 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n", 1854 QEMU_ARCH_ALL) 1855 1856SRST 1857``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly=on] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]`` 1858 \ 1859``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1860 \ 1861``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1862 \ 1863``-virtfs synth,mount_tag=mount_tag`` 1864 Define a new virtual filesystem device and expose it to the guest using 1865 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain 1866 directory on host is made directly accessible by guest as a pass-through 1867 file system by using the 9P network protocol for communication between 1868 host and guests, if desired even accessible, shared by several guests 1869 simultaneously. 1870 1871 Note that ``-virtfs`` is actually just a convenience shortcut for its 1872 generalized form ``-fsdev -device virtio-9p-pci``. 1873 1874 The general form of pass-through file system options are: 1875 1876 ``local`` 1877 Accesses to the filesystem are done by QEMU. 1878 1879 ``proxy`` 1880 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1881 This option is deprecated (since QEMU 8.1) and will be removed in a 1882 future version of QEMU. Use ``local`` instead. 1883 1884 ``synth`` 1885 Synthetic filesystem, only used by QTests. 1886 1887 ``id=id`` 1888 Specifies identifier for the filesystem device 1889 1890 ``path=path`` 1891 Specifies the export path for the file system device. Files 1892 under this path will be available to the 9p client on the guest. 1893 1894 ``security_model=security_model`` 1895 Specifies the security model to be used for this export path. 1896 Supported security models are "passthrough", "mapped-xattr", 1897 "mapped-file" and "none". In "passthrough" security model, files 1898 are stored using the same credentials as they are created on the 1899 guest. This requires QEMU to run as root. In "mapped-xattr" 1900 security model, some of the file attributes like uid, gid, mode 1901 bits and link target are stored as file attributes. For 1902 "mapped-file" these attributes are stored in the hidden 1903 .virtfs\_metadata directory. Directories exported by this 1904 security model cannot interact with other unix tools. "none" 1905 security model is same as passthrough except the sever won't 1906 report failures if it fails to set file attributes like 1907 ownership. Security model is mandatory only for local fsdriver. 1908 Other fsdrivers (like proxy) don't take security model as a 1909 parameter. 1910 1911 ``writeout=writeout`` 1912 This is an optional argument. The only supported value is 1913 "immediate". This means that host page cache will be used to 1914 read and write data but write notification will be sent to the 1915 guest only when the data has been reported as written by the 1916 storage subsystem. 1917 1918 ``readonly=on`` 1919 Enables exporting 9p share as a readonly mount for guests. By 1920 default read-write access is given. 1921 1922 ``socket=socket`` 1923 Enables proxy filesystem driver to use passed socket file for 1924 communicating with virtfs-proxy-helper(1). Usually a helper like 1925 libvirt will create socketpair and pass one of the fds as 1926 sock\_fd. 1927 1928 ``sock_fd`` 1929 Enables proxy filesystem driver to use passed 'sock\_fd' as the 1930 socket descriptor for interfacing with virtfs-proxy-helper(1). 1931 1932 ``fmode=fmode`` 1933 Specifies the default mode for newly created files on the host. 1934 Works only with security models "mapped-xattr" and 1935 "mapped-file". 1936 1937 ``dmode=dmode`` 1938 Specifies the default mode for newly created directories on the 1939 host. Works only with security models "mapped-xattr" and 1940 "mapped-file". 1941 1942 ``mount_tag=mount_tag`` 1943 Specifies the tag name to be used by the guest to mount this 1944 export point. 1945 1946 ``multidevs=multidevs`` 1947 Specifies how to deal with multiple devices being shared with a 1948 9p export. Supported behaviours are either "remap", "forbid" or 1949 "warn". The latter is the default behaviour on which virtfs 9p 1950 expects only one device to be shared with the same export, and 1951 if more than one device is shared and accessed via the same 9p 1952 export then only a warning message is logged (once) by qemu on 1953 host side. In order to avoid file ID collisions on guest you 1954 should either create a separate virtfs export for each device to 1955 be shared with guests (recommended way) or you might use "remap" 1956 instead which allows you to share multiple devices with only one 1957 export instead, which is achieved by remapping the original 1958 inode numbers from host to guest in a way that would prevent 1959 such collisions. Remapping inodes in such use cases is required 1960 because the original device IDs from host are never passed and 1961 exposed on guest. Instead all files of an export shared with 1962 virtfs always share the same device id on guest. So two files 1963 with identical inode numbers but from actually different devices 1964 on host would otherwise cause a file ID collision and hence 1965 potential misbehaviours on guest. "forbid" on the other hand 1966 assumes like "warn" that only one device is shared by the same 1967 export, however it will not only log a warning message but also 1968 deny access to additional devices on guest. Note though that 1969 "forbid" does currently not block all possible file access 1970 operations (e.g. readdir() would still return entries from other 1971 devices). 1972ERST 1973 1974DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1975 "-iscsi [user=user][,password=password][,password-secret=secret-id]\n" 1976 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE]\n" 1977 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1978 " [,timeout=timeout]\n" 1979 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1980 1981SRST 1982``-iscsi`` 1983 Configure iSCSI session parameters. 1984ERST 1985 1986DEFHEADING() 1987 1988DEFHEADING(USB convenience options:) 1989 1990DEF("usb", 0, QEMU_OPTION_usb, 1991 "-usb enable on-board USB host controller (if not enabled by default)\n", 1992 QEMU_ARCH_ALL) 1993SRST 1994``-usb`` 1995 Enable USB emulation on machine types with an on-board USB host 1996 controller (if not enabled by default). Note that on-board USB host 1997 controllers may not support USB 3.0. In this case 1998 ``-device qemu-xhci`` can be used instead on machines with PCI. 1999ERST 2000 2001DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 2002 "-usbdevice name add the host or guest USB device 'name'\n", 2003 QEMU_ARCH_ALL) 2004SRST 2005``-usbdevice devname`` 2006 Add the USB device devname, and enable an on-board USB controller 2007 if possible and necessary (just like it can be done via 2008 ``-machine usb=on``). Note that this option is mainly intended for 2009 the user's convenience only. More fine-grained control can be 2010 achieved by selecting a USB host controller (if necessary) and the 2011 desired USB device via the ``-device`` option instead. For example, 2012 instead of using ``-usbdevice mouse`` it is possible to use 2013 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse 2014 to a USB 3.0 controller instead (at least on machines that support 2015 PCI and do not have an USB controller enabled by default yet). 2016 For more details, see the chapter about 2017 :ref:`Connecting USB devices` in the System Emulation Users Guide. 2018 Possible devices for devname are: 2019 2020 ``braille`` 2021 Braille device. This will use BrlAPI to display the braille 2022 output on a real or fake device (i.e. it also creates a 2023 corresponding ``braille`` chardev automatically beside the 2024 ``usb-braille`` USB device). 2025 2026 ``keyboard`` 2027 Standard USB keyboard. Will override the PS/2 keyboard (if present). 2028 2029 ``mouse`` 2030 Virtual Mouse. This will override the PS/2 mouse emulation when 2031 activated. 2032 2033 ``tablet`` 2034 Pointer device that uses absolute coordinates (like a 2035 touchscreen). This means QEMU is able to report the mouse 2036 position without having to grab the mouse. Also overrides the 2037 PS/2 mouse emulation when activated. 2038 2039 ``wacom-tablet`` 2040 Wacom PenPartner USB tablet. 2041 2042 2043ERST 2044 2045DEFHEADING() 2046 2047DEFHEADING(Display options:) 2048 2049DEF("display", HAS_ARG, QEMU_OPTION_display, 2050#if defined(CONFIG_SPICE) 2051 "-display spice-app[,gl=on|off]\n" 2052#endif 2053#if defined(CONFIG_SDL) 2054 "-display sdl[,gl=on|core|es|off][,grab-mod=<mod>][,show-cursor=on|off]\n" 2055 " [,window-close=on|off]\n" 2056#endif 2057#if defined(CONFIG_GTK) 2058 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n" 2059 " [,show-tabs=on|off][,show-cursor=on|off][,window-close=on|off]\n" 2060 " [,show-menubar=on|off]\n" 2061#endif 2062#if defined(CONFIG_VNC) 2063 "-display vnc=<display>[,<optargs>]\n" 2064#endif 2065#if defined(CONFIG_CURSES) 2066 "-display curses[,charset=<encoding>]\n" 2067#endif 2068#if defined(CONFIG_COCOA) 2069 "-display cocoa[,full-grab=on|off][,swap-opt-cmd=on|off]\n" 2070#endif 2071#if defined(CONFIG_OPENGL) 2072 "-display egl-headless[,rendernode=<file>]\n" 2073#endif 2074#if defined(CONFIG_DBUS_DISPLAY) 2075 "-display dbus[,addr=<dbusaddr>]\n" 2076 " [,gl=on|core|es|off][,rendernode=<file>]\n" 2077#endif 2078#if defined(CONFIG_COCOA) 2079 "-display cocoa[,show-cursor=on|off][,left-command-key=on|off]\n" 2080#endif 2081 "-display none\n" 2082 " select display backend type\n" 2083 " The default display is equivalent to\n " 2084#if defined(CONFIG_GTK) 2085 "\"-display gtk\"\n" 2086#elif defined(CONFIG_SDL) 2087 "\"-display sdl\"\n" 2088#elif defined(CONFIG_COCOA) 2089 "\"-display cocoa\"\n" 2090#elif defined(CONFIG_VNC) 2091 "\"-vnc localhost:0,to=99,id=default\"\n" 2092#else 2093 "\"-display none\"\n" 2094#endif 2095 , QEMU_ARCH_ALL) 2096SRST 2097``-display type`` 2098 Select type of display to use. Use ``-display help`` to list the available 2099 display types. Valid values for type are 2100 2101 ``spice-app[,gl=on|off]`` 2102 Start QEMU as a Spice server and launch the default Spice client 2103 application. The Spice server will redirect the serial consoles 2104 and QEMU monitors. (Since 4.0) 2105 2106 ``dbus`` 2107 Export the display over D-Bus interfaces. (Since 7.0) 2108 2109 The connection is registered with the "org.qemu" name (and queued when 2110 already owned). 2111 2112 ``addr=<dbusaddr>`` : D-Bus bus address to connect to. 2113 2114 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``. 2115 2116 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface 2117 will share framebuffers with DMABUF file descriptors). 2118 2119 ``sdl`` 2120 Display video output via SDL (usually in a separate graphics 2121 window; see the SDL documentation for other possibilities). 2122 Valid parameters are: 2123 2124 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling 2125 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be 2126 either ``lshift-lctrl-lalt`` or ``rctrl``. 2127 2128 ``gl=on|off|core|es`` : Use OpenGL for displaying 2129 2130 ``show-cursor=on|off`` : Force showing the mouse cursor 2131 2132 ``window-close=on|off`` : Allow to quit qemu with window close button 2133 2134 ``gtk`` 2135 Display video output in a GTK window. This interface provides 2136 drop-down menus and other UI elements to configure and control 2137 the VM during runtime. Valid parameters are: 2138 2139 ``full-screen=on|off`` : Start in fullscreen mode 2140 2141 ``gl=on|off`` : Use OpenGL for displaying 2142 2143 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover 2144 2145 ``show-tabs=on|off`` : Display the tab bar for switching between the 2146 various graphical interfaces (e.g. VGA and 2147 virtual console character devices) by default. 2148 2149 ``show-cursor=on|off`` : Force showing the mouse cursor 2150 2151 ``window-close=on|off`` : Allow to quit qemu with window close button 2152 2153 ``show-menubar=on|off`` : Display the main window menubar, defaults to "on" 2154 2155 ``zoom-to-fit=on|off`` : Expand video output to the window size, 2156 defaults to "off" 2157 2158 ``curses[,charset=<encoding>]`` 2159 Display video output via curses. For graphics device models 2160 which support a text mode, QEMU can display this output using a 2161 curses/ncurses interface. Nothing is displayed when the graphics 2162 device is in graphical mode or if the graphics device does not 2163 support a text mode. Generally only the VGA device models 2164 support text mode. The font charset used by the guest can be 2165 specified with the ``charset`` option, for example 2166 ``charset=CP850`` for IBM CP850 encoding. The default is 2167 ``CP437``. 2168 2169 ``cocoa`` 2170 Display video output in a Cocoa window. Mac only. This interface 2171 provides drop-down menus and other UI elements to configure and 2172 control the VM during runtime. Valid parameters are: 2173 2174 ``show-cursor=on|off`` : Force showing the mouse cursor 2175 2176 ``left-command-key=on|off`` : Disable forwarding left command key to host 2177 2178 ``egl-headless[,rendernode=<file>]`` 2179 Offload all OpenGL operations to a local DRI device. For any 2180 graphical display, this display needs to be paired with either 2181 VNC or SPICE displays. 2182 2183 ``vnc=<display>`` 2184 Start a VNC server on display <display> 2185 2186 ``none`` 2187 Do not display video output. The guest will still see an 2188 emulated graphics card, but its output will not be displayed to 2189 the QEMU user. This option differs from the -nographic option in 2190 that it only affects what is done with video output; -nographic 2191 also changes the destination of the serial and parallel port 2192 data. 2193ERST 2194 2195DEF("nographic", 0, QEMU_OPTION_nographic, 2196 "-nographic disable graphical output and redirect serial I/Os to console\n", 2197 QEMU_ARCH_ALL) 2198SRST 2199``-nographic`` 2200 Normally, if QEMU is compiled with graphical window support, it 2201 displays output such as guest graphics, guest console, and the QEMU 2202 monitor in a window. With this option, you can totally disable 2203 graphical output so that QEMU is a simple command line application. 2204 The emulated serial port is redirected on the console and muxed with 2205 the monitor (unless redirected elsewhere explicitly). Therefore, you 2206 can still use QEMU to debug a Linux kernel with a serial console. 2207 Use C-a h for help on switching between the console and monitor. 2208ERST 2209 2210#ifdef CONFIG_SPICE 2211DEF("spice", HAS_ARG, QEMU_OPTION_spice, 2212 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 2213 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 2214 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 2215 " [,x509-dh-key-file=<file>][,addr=addr]\n" 2216 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n" 2217 " [,tls-ciphers=<list>]\n" 2218 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 2219 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 2220 " [,sasl=on|off][,disable-ticketing=on|off]\n" 2221 " [,password-secret=<secret-id>]\n" 2222 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 2223 " [,jpeg-wan-compression=[auto|never|always]]\n" 2224 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 2225 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n" 2226 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n" 2227 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 2228 " [,gl=[on|off]][,rendernode=<file>]\n" 2229 " enable spice\n" 2230 " at least one of {port, tls-port} is mandatory\n", 2231 QEMU_ARCH_ALL) 2232#endif 2233SRST 2234``-spice option[,option[,...]]`` 2235 Enable the spice remote desktop protocol. Valid options are 2236 2237 ``port=<nr>`` 2238 Set the TCP port spice is listening on for plaintext channels. 2239 2240 ``addr=<addr>`` 2241 Set the IP address spice is listening on. Default is any 2242 address. 2243 2244 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off`` 2245 Force using the specified IP version. 2246 2247 ``password-secret=<secret-id>`` 2248 Set the ID of the ``secret`` object containing the password 2249 you need to authenticate. 2250 2251 ``sasl=on|off`` 2252 Require that the client use SASL to authenticate with the spice. 2253 The exact choice of authentication method used is controlled 2254 from the system / user's SASL configuration file for the 'qemu' 2255 service. This is typically found in /etc/sasl2/qemu.conf. If 2256 running QEMU as an unprivileged user, an environment variable 2257 SASL\_CONF\_PATH can be used to make it search alternate 2258 locations for the service config. While some SASL auth methods 2259 can also provide data encryption (eg GSSAPI), it is recommended 2260 that SASL always be combined with the 'tls' and 'x509' settings 2261 to enable use of SSL and server certificates. This ensures a 2262 data encryption preventing compromise of authentication 2263 credentials. 2264 2265 ``disable-ticketing=on|off`` 2266 Allow client connects without authentication. 2267 2268 ``disable-copy-paste=on|off`` 2269 Disable copy paste between the client and the guest. 2270 2271 ``disable-agent-file-xfer=on|off`` 2272 Disable spice-vdagent based file-xfer between the client and the 2273 guest. 2274 2275 ``tls-port=<nr>`` 2276 Set the TCP port spice is listening on for encrypted channels. 2277 2278 ``x509-dir=<dir>`` 2279 Set the x509 file directory. Expects same filenames as -vnc 2280 $display,x509=$dir 2281 2282 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>`` 2283 The x509 file names can also be configured individually. 2284 2285 ``tls-ciphers=<list>`` 2286 Specify which ciphers to use. 2287 2288 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]`` 2289 Force specific channel to be used with or without TLS 2290 encryption. The options can be specified multiple times to 2291 configure multiple channels. The special name "default" can be 2292 used to set the default mode. For channels which are not 2293 explicitly forced into one mode the spice client is allowed to 2294 pick tls/plaintext as he pleases. 2295 2296 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]`` 2297 Configure image compression (lossless). Default is auto\_glz. 2298 2299 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]`` 2300 Configure wan image compression (lossy for slow links). Default 2301 is auto. 2302 2303 ``streaming-video=[off|all|filter]`` 2304 Configure video stream detection. Default is off. 2305 2306 ``agent-mouse=[on|off]`` 2307 Enable/disable passing mouse events via vdagent. Default is on. 2308 2309 ``playback-compression=[on|off]`` 2310 Enable/disable audio stream compression (using celt 0.5.1). 2311 Default is on. 2312 2313 ``seamless-migration=[on|off]`` 2314 Enable/disable spice seamless migration. Default is off. 2315 2316 ``gl=[on|off]`` 2317 Enable/disable OpenGL context. Default is off. 2318 2319 ``rendernode=<file>`` 2320 DRM render node for OpenGL rendering. If not specified, it will 2321 pick the first available. (Since 2.9) 2322ERST 2323 2324DEF("portrait", 0, QEMU_OPTION_portrait, 2325 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 2326 QEMU_ARCH_ALL) 2327SRST 2328``-portrait`` 2329 Rotate graphical output 90 deg left (only PXA LCD). 2330ERST 2331 2332DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 2333 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 2334 QEMU_ARCH_ALL) 2335SRST 2336``-rotate deg`` 2337 Rotate graphical output some deg left (only PXA LCD). 2338ERST 2339 2340DEF("vga", HAS_ARG, QEMU_OPTION_vga, 2341 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 2342 " select video card type\n", QEMU_ARCH_ALL) 2343SRST 2344``-vga type`` 2345 Select type of VGA card to emulate. Valid values for type are 2346 2347 ``cirrus`` 2348 Cirrus Logic GD5446 Video card. All Windows versions starting 2349 from Windows 95 should recognize and use this graphic card. For 2350 optimal performances, use 16 bit color depth in the guest and 2351 the host OS. (This card was the default before QEMU 2.2) 2352 2353 ``std`` 2354 Standard VGA card with Bochs VBE extensions. If your guest OS 2355 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if 2356 you want to use high resolution modes (>= 1280x1024x16) then you 2357 should use this option. (This card is the default since QEMU 2358 2.2) 2359 2360 ``vmware`` 2361 VMWare SVGA-II compatible adapter. Use it if you have 2362 sufficiently recent XFree86/XOrg server or Windows guest with a 2363 driver for this card. 2364 2365 ``qxl`` 2366 QXL paravirtual graphic card. It is VGA compatible (including 2367 VESA 2.0 VBE support). Works best with qxl guest drivers 2368 installed though. Recommended choice when using the spice 2369 protocol. 2370 2371 ``tcx`` 2372 (sun4m only) Sun TCX framebuffer. This is the default 2373 framebuffer for sun4m machines and offers both 8-bit and 24-bit 2374 colour depths at a fixed resolution of 1024x768. 2375 2376 ``cg3`` 2377 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit 2378 framebuffer for sun4m machines available in both 1024x768 2379 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people 2380 wishing to run older Solaris versions. 2381 2382 ``virtio`` 2383 Virtio VGA card. 2384 2385 ``none`` 2386 Disable VGA card. 2387ERST 2388 2389DEF("full-screen", 0, QEMU_OPTION_full_screen, 2390 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 2391SRST 2392``-full-screen`` 2393 Start in full screen. 2394ERST 2395 2396DEF("g", HAS_ARG, QEMU_OPTION_g , 2397 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 2398 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 2399SRST 2400``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]`` 2401 Set the initial graphical resolution and depth (PPC, SPARC only). 2402 2403 For PPC the default is 800x600x32. 2404 2405 For SPARC with the TCX graphics device, the default is 1024x768x8 2406 with the option of 1024x768x24. For cgthree, the default is 2407 1024x768x8 with the option of 1152x900x8 for people who wish to use 2408 OBP. 2409ERST 2410 2411DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 2412 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 2413SRST 2414``-vnc display[,option[,option[,...]]]`` 2415 Normally, if QEMU is compiled with graphical window support, it 2416 displays output such as guest graphics, guest console, and the QEMU 2417 monitor in a window. With this option, you can have QEMU listen on 2418 VNC display display and redirect the VGA display over the VNC 2419 session. It is very useful to enable the usb tablet device when 2420 using this option (option ``-device usb-tablet``). When using the 2421 VNC display, you must use the ``-k`` parameter to set the keyboard 2422 layout if you are not using en-us. Valid syntax for the display is 2423 2424 ``to=L`` 2425 With this option, QEMU will try next available VNC displays, 2426 until the number L, if the origianlly defined "-vnc display" is 2427 not available, e.g. port 5900+display is already used by another 2428 application. By default, to=0. 2429 2430 ``host:d`` 2431 TCP connections will only be allowed from host on display d. By 2432 convention the TCP port is 5900+d. Optionally, host can be 2433 omitted in which case the server will accept connections from 2434 any host. 2435 2436 ``unix:path`` 2437 Connections will be allowed over UNIX domain sockets where path 2438 is the location of a unix socket to listen for connections on. 2439 2440 ``none`` 2441 VNC is initialized but not started. The monitor ``change`` 2442 command can be used to later start the VNC server. 2443 2444 Following the display value there may be one or more option flags 2445 separated by commas. Valid options are 2446 2447 ``reverse=on|off`` 2448 Connect to a listening VNC client via a "reverse" connection. 2449 The client is specified by the display. For reverse network 2450 connections (host:d,``reverse``), the d argument is a TCP port 2451 number, not a display number. 2452 2453 ``websocket=on|off`` 2454 Opens an additional TCP listening port dedicated to VNC 2455 Websocket connections. If a bare websocket option is given, the 2456 Websocket port is 5700+display. An alternative port can be 2457 specified with the syntax ``websocket``\ =port. 2458 2459 If host is specified connections will only be allowed from this 2460 host. It is possible to control the websocket listen address 2461 independently, using the syntax ``websocket``\ =host:port. 2462 2463 If no TLS credentials are provided, the websocket connection 2464 runs in unencrypted mode. If TLS credentials are provided, the 2465 websocket connection requires encrypted client connections. 2466 2467 ``password=on|off`` 2468 Require that password based authentication is used for client 2469 connections. 2470 2471 The password must be set separately using the ``set_password`` 2472 command in the :ref:`QEMU monitor`. The 2473 syntax to change your password is: 2474 ``set_password <protocol> <password>`` where <protocol> could be 2475 either "vnc" or "spice". 2476 2477 If you would like to change <protocol> password expiration, you 2478 should use ``expire_password <protocol> <expiration-time>`` 2479 where expiration time could be one of the following options: 2480 now, never, +seconds or UNIX time of expiration, e.g. +60 to 2481 make password expire in 60 seconds, or 1335196800 to make 2482 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for 2483 this date and time). 2484 2485 You can also use keywords "now" or "never" for the expiration 2486 time to allow <protocol> password to expire immediately or never 2487 expire. 2488 2489 ``password-secret=<secret-id>`` 2490 Require that password based authentication is used for client 2491 connections, using the password provided by the ``secret`` 2492 object identified by ``secret-id``. 2493 2494 ``tls-creds=ID`` 2495 Provides the ID of a set of TLS credentials to use to secure the 2496 VNC server. They will apply to both the normal VNC server socket 2497 and the websocket socket (if enabled). Setting TLS credentials 2498 will cause the VNC server socket to enable the VeNCrypt auth 2499 mechanism. The credentials should have been previously created 2500 using the ``-object tls-creds`` argument. 2501 2502 ``tls-authz=ID`` 2503 Provides the ID of the QAuthZ authorization object against which 2504 the client's x509 distinguished name will validated. This object 2505 is only resolved at time of use, so can be deleted and recreated 2506 on the fly while the VNC server is active. If missing, it will 2507 default to denying access. 2508 2509 ``sasl=on|off`` 2510 Require that the client use SASL to authenticate with the VNC 2511 server. The exact choice of authentication method used is 2512 controlled from the system / user's SASL configuration file for 2513 the 'qemu' service. This is typically found in 2514 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, 2515 an environment variable SASL\_CONF\_PATH can be used to make it 2516 search alternate locations for the service config. While some 2517 SASL auth methods can also provide data encryption (eg GSSAPI), 2518 it is recommended that SASL always be combined with the 'tls' 2519 and 'x509' settings to enable use of SSL and server 2520 certificates. This ensures a data encryption preventing 2521 compromise of authentication credentials. See the 2522 :ref:`VNC security` section in the System Emulation Users Guide 2523 for details on using SASL authentication. 2524 2525 ``sasl-authz=ID`` 2526 Provides the ID of the QAuthZ authorization object against which 2527 the client's SASL username will validated. This object is only 2528 resolved at time of use, so can be deleted and recreated on the 2529 fly while the VNC server is active. If missing, it will default 2530 to denying access. 2531 2532 ``acl=on|off`` 2533 Legacy method for enabling authorization of clients against the 2534 x509 distinguished name and SASL username. It results in the 2535 creation of two ``authz-list`` objects with IDs of 2536 ``vnc.username`` and ``vnc.x509dname``. The rules for these 2537 objects must be configured with the HMP ACL commands. 2538 2539 This option is deprecated and should no longer be used. The new 2540 ``sasl-authz`` and ``tls-authz`` options are a replacement. 2541 2542 ``lossy=on|off`` 2543 Enable lossy compression methods (gradient, JPEG, ...). If this 2544 option is set, VNC client may receive lossy framebuffer updates 2545 depending on its encoding settings. Enabling this option can 2546 save a lot of bandwidth at the expense of quality. 2547 2548 ``non-adaptive=on|off`` 2549 Disable adaptive encodings. Adaptive encodings are enabled by 2550 default. An adaptive encoding will try to detect frequently 2551 updated screen regions, and send updates in these regions using 2552 a lossy encoding (like JPEG). This can be really helpful to save 2553 bandwidth when playing videos. Disabling adaptive encodings 2554 restores the original static behavior of encodings like Tight. 2555 2556 ``share=[allow-exclusive|force-shared|ignore]`` 2557 Set display sharing policy. 'allow-exclusive' allows clients to 2558 ask for exclusive access. As suggested by the rfb spec this is 2559 implemented by dropping other connections. Connecting multiple 2560 clients in parallel requires all clients asking for a shared 2561 session (vncviewer: -shared switch). This is the default. 2562 'force-shared' disables exclusive client access. Useful for 2563 shared desktop sessions, where you don't want someone forgetting 2564 specify -shared disconnect everybody else. 'ignore' completely 2565 ignores the shared flag and allows everybody connect 2566 unconditionally. Doesn't conform to the rfb spec but is 2567 traditional QEMU behavior. 2568 2569 ``key-delay-ms`` 2570 Set keyboard delay, for key down and key up events, in 2571 milliseconds. Default is 10. Keyboards are low-bandwidth 2572 devices, so this slowdown can help the device and guest to keep 2573 up and not lose events in case events are arriving in bulk. 2574 Possible causes for the latter are flaky network connections, or 2575 scripts for automated testing. 2576 2577 ``audiodev=audiodev`` 2578 Use the specified audiodev when the VNC client requests audio 2579 transmission. When not using an -audiodev argument, this option 2580 must be omitted, otherwise is must be present and specify a 2581 valid audiodev. 2582 2583 ``power-control=on|off`` 2584 Permit the remote client to issue shutdown, reboot or reset power 2585 control requests. 2586ERST 2587 2588ARCHHEADING(, QEMU_ARCH_I386) 2589 2590ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2591 2592DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2593 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2594 QEMU_ARCH_I386) 2595SRST 2596``-win2k-hack`` 2597 Use it when installing Windows 2000 to avoid a disk full bug. After 2598 Windows 2000 is installed, you no longer need this option (this 2599 option slows down the IDE transfers). 2600ERST 2601 2602DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2603 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2604 QEMU_ARCH_I386) 2605SRST 2606``-no-fd-bootchk`` 2607 Disable boot signature checking for floppy disks in BIOS. May be 2608 needed to boot from old floppy disks. 2609ERST 2610 2611DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2612 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2613SRST 2614``-no-acpi`` 2615 Disable ACPI (Advanced Configuration and Power Interface) support. 2616 Use it if your guest OS complains about ACPI problems (PC target 2617 machine only). 2618ERST 2619 2620DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2621 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2622SRST 2623``-no-hpet`` 2624 Disable HPET support. Deprecated, use '-machine hpet=off' instead. 2625ERST 2626 2627DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2628 "-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" 2629 " ACPI table description\n", QEMU_ARCH_I386) 2630SRST 2631``-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]...]`` 2632 Add ACPI table with specified header fields and context from 2633 specified files. For file=, take whole ACPI table from the specified 2634 files, including all ACPI headers (possible overridden by other 2635 options). For data=, only data portion of the table is used, all 2636 header information is specified in the command line. If a SLIC table 2637 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id 2638 fields will override the same in the RSDT and the FADT (a.k.a. 2639 FACP), in order to ensure the field matches required by the 2640 Microsoft SLIC spec and the ACPI spec. 2641ERST 2642 2643DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2644 "-smbios file=binary\n" 2645 " load SMBIOS entry from binary file\n" 2646 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2647 " [,uefi=on|off]\n" 2648 " specify SMBIOS type 0 fields\n" 2649 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2650 " [,uuid=uuid][,sku=str][,family=str]\n" 2651 " specify SMBIOS type 1 fields\n" 2652 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2653 " [,asset=str][,location=str]\n" 2654 " specify SMBIOS type 2 fields\n" 2655 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2656 " [,sku=str]\n" 2657 " specify SMBIOS type 3 fields\n" 2658 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2659 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n" 2660 " [,processor-id=%d]\n" 2661 " specify SMBIOS type 4 fields\n" 2662 "-smbios type=8[,external_reference=str][,internal_reference=str][,connector_type=%d][,port_type=%d]\n" 2663 " specify SMBIOS type 8 fields\n" 2664 "-smbios type=11[,value=str][,path=filename]\n" 2665 " specify SMBIOS type 11 fields\n" 2666 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2667 " [,asset=str][,part=str][,speed=%d]\n" 2668 " specify SMBIOS type 17 fields\n" 2669 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n" 2670 " specify SMBIOS type 41 fields\n", 2671 QEMU_ARCH_I386 | QEMU_ARCH_ARM | QEMU_ARCH_LOONGARCH) 2672SRST 2673``-smbios file=binary`` 2674 Load SMBIOS entry from binary file. 2675 2676``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]`` 2677 Specify SMBIOS type 0 fields 2678 2679``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]`` 2680 Specify SMBIOS type 1 fields 2681 2682``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]`` 2683 Specify SMBIOS type 2 fields 2684 2685``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]`` 2686 Specify SMBIOS type 3 fields 2687 2688``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str][,processor-id=%d]`` 2689 Specify SMBIOS type 4 fields 2690 2691``-smbios type=11[,value=str][,path=filename]`` 2692 Specify SMBIOS type 11 fields 2693 2694 This argument can be repeated multiple times, and values are added in the order they are parsed. 2695 Applications intending to use OEM strings data are encouraged to use their application name as 2696 a prefix for the value string. This facilitates passing information for multiple applications 2697 concurrently. 2698 2699 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax 2700 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes. 2701 2702 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to 2703 the SMBIOS table in the order in which they appear. 2704 2705 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535 2706 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the 2707 guest. Instead it should be used as a indicator to inform the guest where to locate the real 2708 data set, for example, by specifying the serial ID of a block device. 2709 2710 An example passing three strings is 2711 2712 .. parsed-literal:: 2713 2714 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\ 2715 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\ 2716 path=/some/file/with/oemstringsdata.txt 2717 2718 In the guest OS this is visible with the ``dmidecode`` command 2719 2720 .. parsed-literal:: 2721 2722 $ dmidecode -t 11 2723 Handle 0x0E00, DMI type 11, 5 bytes 2724 OEM Strings 2725 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/ 2726 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os 2727 String 3: myapp:some extra data 2728 2729 2730``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]`` 2731 Specify SMBIOS type 17 fields 2732 2733``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]`` 2734 Specify SMBIOS type 41 fields 2735 2736 This argument can be repeated multiple times. Its main use is to allow network interfaces be created 2737 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface 2738 position on the PCI bus. 2739 2740 Here is an example of use: 2741 2742 .. parsed-literal:: 2743 2744 -netdev user,id=internet \\ 2745 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\ 2746 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev 2747 2748 In the guest OS, the device should then appear as ``eno1``: 2749 2750 ..parsed-literal:: 2751 2752 $ ip -brief l 2753 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP> 2754 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP> 2755 2756 Currently, the PCI device has to be attached to the root bus. 2757 2758ERST 2759 2760DEFHEADING() 2761 2762DEFHEADING(Network options:) 2763 2764DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2765#ifdef CONFIG_SLIRP 2766 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n" 2767 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2768 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2769 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2770 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2771#ifndef _WIN32 2772 "[,smb=dir[,smbserver=addr]]\n" 2773#endif 2774 " configure a user mode network backend with ID 'str',\n" 2775 " its DHCP server and optional services\n" 2776#endif 2777#ifdef _WIN32 2778 "-netdev tap,id=str,ifname=name\n" 2779 " configure a host TAP network backend with ID 'str'\n" 2780#else 2781 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2782 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2783 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2784 " [,poll-us=n]\n" 2785 " configure a host TAP network backend with ID 'str'\n" 2786 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2787 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2788 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2789 " to deconfigure it\n" 2790 " use '[down]script=no' to disable script execution\n" 2791 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2792 " configure it\n" 2793 " use 'fd=h' to connect to an already opened TAP interface\n" 2794 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2795 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2796 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2797 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2798 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2799 " use vhost=on to enable experimental in kernel accelerator\n" 2800 " (only has effect for virtio guests which use MSIX)\n" 2801 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2802 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2803 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2804 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2805 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n" 2806 " spent on busy polling for vhost net\n" 2807 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2808 " configure a host TAP network backend with ID 'str' that is\n" 2809 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2810 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2811#endif 2812#ifdef __linux__ 2813 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2814 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n" 2815 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n" 2816 " [,rxcookie=rxcookie][,offset=offset]\n" 2817 " configure a network backend with ID 'str' connected to\n" 2818 " an Ethernet over L2TPv3 pseudowire.\n" 2819 " Linux kernel 3.3+ as well as most routers can talk\n" 2820 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2821 " VM to a router and even VM to Host. It is a nearly-universal\n" 2822 " standard (RFC3931). Note - this implementation uses static\n" 2823 " pre-configured tunnels (same as the Linux kernel).\n" 2824 " use 'src=' to specify source address\n" 2825 " use 'dst=' to specify destination address\n" 2826 " use 'udp=on' to specify udp encapsulation\n" 2827 " use 'srcport=' to specify source udp port\n" 2828 " use 'dstport=' to specify destination udp port\n" 2829 " use 'ipv6=on' to force v6\n" 2830 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2831 " well as a weak security measure\n" 2832 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2833 " use 'txcookie=0x012345678' to specify a txcookie\n" 2834 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2835 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2836 " use 'pincounter=on' to work around broken counter handling in peer\n" 2837 " use 'offset=X' to add an extra offset between header and data\n" 2838#endif 2839 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2840 " configure a network backend to connect to another network\n" 2841 " using a socket connection\n" 2842 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2843 " configure a network backend to connect to a multicast maddr and port\n" 2844 " use 'localaddr=addr' to specify the host address to send packets from\n" 2845 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2846 " configure a network backend to connect to another network\n" 2847 " using an UDP tunnel\n" 2848 "-netdev stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port[,to=maxport][,numeric=on|off][,keep-alive=on|off][,mptcp=on|off][,addr.ipv4=on|off][,addr.ipv6=on|off][,reconnect=seconds]\n" 2849 "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect=seconds]\n" 2850 "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect=seconds]\n" 2851 " configure a network backend to connect to another network\n" 2852 " using a socket connection in stream mode.\n" 2853 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n" 2854 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]\n" 2855 " configure a network backend to connect to a multicast maddr and port\n" 2856 " use ``local.host=addr`` to specify the host address to send packets from\n" 2857 "-netdev dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]\n" 2858 "-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]\n" 2859 "-netdev dgram,id=str,local.type=fd,local.str=file-descriptor\n" 2860 " configure a network backend to connect to another network\n" 2861 " using an UDP tunnel\n" 2862#ifdef CONFIG_VDE 2863 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2864 " configure a network backend to connect to port 'n' of a vde switch\n" 2865 " running on host and listening for incoming connections on 'socketpath'.\n" 2866 " Use group 'groupname' and mode 'octalmode' to change default\n" 2867 " ownership and permissions for communication port.\n" 2868#endif 2869#ifdef CONFIG_NETMAP 2870 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2871 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2872 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2873 " netmap device, defaults to '/dev/netmap')\n" 2874#endif 2875#ifdef CONFIG_AF_XDP 2876 "-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off]\n" 2877 " [,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]\n" 2878 " attach to the existing network interface 'name' with AF_XDP socket\n" 2879 " use 'mode=MODE' to specify an XDP program attach mode\n" 2880 " use 'force-copy=on|off' to force XDP copy mode even if device supports zero-copy (default: off)\n" 2881 " use 'inhibit=on|off' to inhibit loading of a default XDP program (default: off)\n" 2882 " with inhibit=on,\n" 2883 " use 'sock-fds' to provide file descriptors for already open AF_XDP sockets\n" 2884 " added to a socket map in XDP program. One socket per queue.\n" 2885 " use 'queues=n' to specify how many queues of a multiqueue interface should be used\n" 2886 " use 'start-queue=m' to specify the first queue that should be used\n" 2887#endif 2888#ifdef CONFIG_POSIX 2889 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2890 " configure a vhost-user network, backed by a chardev 'dev'\n" 2891#endif 2892#ifdef __linux__ 2893 "-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n" 2894 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n" 2895 " use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n" 2896 " use 'vhostfd=h' to connect to an already opened vhost vdpa device\n" 2897#endif 2898#ifdef CONFIG_VMNET 2899 "-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n" 2900 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2901 " configure a vmnet network backend in host mode with ID 'str',\n" 2902 " isolate this interface from others with 'isolated',\n" 2903 " configure the address range and choose a subnet mask,\n" 2904 " specify network UUID 'uuid' to disable DHCP and interact with\n" 2905 " vmnet-host interfaces within this isolated network\n" 2906 "-netdev vmnet-shared,id=str[,isolated=on|off][,nat66-prefix=addr]\n" 2907 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2908 " configure a vmnet network backend in shared mode with ID 'str',\n" 2909 " configure the address range and choose a subnet mask,\n" 2910 " set IPv6 ULA prefix (of length 64) to use for internal network,\n" 2911 " isolate this interface from others with 'isolated'\n" 2912 "-netdev vmnet-bridged,id=str,ifname=name[,isolated=on|off]\n" 2913 " configure a vmnet network backend in bridged mode with ID 'str',\n" 2914 " use 'ifname=name' to select a physical network interface to be bridged,\n" 2915 " isolate this interface from others with 'isolated'\n" 2916#endif 2917 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2918 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2919DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2920 "-nic [tap|bridge|" 2921#ifdef CONFIG_SLIRP 2922 "user|" 2923#endif 2924#ifdef __linux__ 2925 "l2tpv3|" 2926#endif 2927#ifdef CONFIG_VDE 2928 "vde|" 2929#endif 2930#ifdef CONFIG_NETMAP 2931 "netmap|" 2932#endif 2933#ifdef CONFIG_AF_XDP 2934 "af-xdp|" 2935#endif 2936#ifdef CONFIG_POSIX 2937 "vhost-user|" 2938#endif 2939#ifdef CONFIG_VMNET 2940 "vmnet-host|vmnet-shared|vmnet-bridged|" 2941#endif 2942 "socket][,option][,...][mac=macaddr]\n" 2943 " initialize an on-board / default host NIC (using MAC address\n" 2944 " macaddr) and connect it to the given host network backend\n" 2945 "-nic none use it alone to have zero network devices (the default is to\n" 2946 " provided a 'user' network connection)\n", 2947 QEMU_ARCH_ALL) 2948DEF("net", HAS_ARG, QEMU_OPTION_net, 2949 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2950 " configure or create an on-board (or machine default) NIC and\n" 2951 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2952 "-net [" 2953#ifdef CONFIG_SLIRP 2954 "user|" 2955#endif 2956 "tap|" 2957 "bridge|" 2958#ifdef CONFIG_VDE 2959 "vde|" 2960#endif 2961#ifdef CONFIG_NETMAP 2962 "netmap|" 2963#endif 2964#ifdef CONFIG_AF_XDP 2965 "af-xdp|" 2966#endif 2967#ifdef CONFIG_VMNET 2968 "vmnet-host|vmnet-shared|vmnet-bridged|" 2969#endif 2970 "socket][,option][,option][,...]\n" 2971 " old way to initialize a host network interface\n" 2972 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2973SRST 2974``-nic [tap|bridge|user|l2tpv3|vde|netmap|af-xdp|vhost-user|socket][,...][,mac=macaddr][,model=mn]`` 2975 This option is a shortcut for configuring both the on-board 2976 (default) guest NIC hardware and the host network backend in one go. 2977 The host backend options are the same as with the corresponding 2978 ``-netdev`` options below. The guest NIC model can be set with 2979 ``model=modelname``. Use ``model=help`` to list the available device 2980 types. The hardware MAC address can be set with ``mac=macaddr``. 2981 2982 The following two example do exactly the same, to show how ``-nic`` 2983 can be used to shorten the command line length: 2984 2985 .. parsed-literal:: 2986 2987 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2988 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2989 2990``-nic none`` 2991 Indicate that no network devices should be configured. It is used to 2992 override the default configuration (default NIC with "user" host 2993 network backend) which is activated if no other networking options 2994 are provided. 2995 2996``-netdev user,id=id[,option][,option][,...]`` 2997 Configure user mode host network backend which requires no 2998 administrator privilege to run. Valid options are: 2999 3000 ``id=id`` 3001 Assign symbolic name for use in monitor commands. 3002 3003 ``ipv4=on|off and ipv6=on|off`` 3004 Specify that either IPv4 or IPv6 must be enabled. If neither is 3005 specified both protocols are enabled. 3006 3007 ``net=addr[/mask]`` 3008 Set IP network address the guest will see. Optionally specify 3009 the netmask, either in the form a.b.c.d or as number of valid 3010 top-most bits. Default is 10.0.2.0/24. 3011 3012 ``host=addr`` 3013 Specify the guest-visible address of the host. Default is the 3014 2nd IP in the guest network, i.e. x.x.x.2. 3015 3016 ``ipv6-net=addr[/int]`` 3017 Set IPv6 network address the guest will see (default is 3018 fec0::/64). The network prefix is given in the usual hexadecimal 3019 IPv6 address notation. The prefix size is optional, and is given 3020 as the number of valid top-most bits (default is 64). 3021 3022 ``ipv6-host=addr`` 3023 Specify the guest-visible IPv6 address of the host. Default is 3024 the 2nd IPv6 in the guest network, i.e. xxxx::2. 3025 3026 ``restrict=on|off`` 3027 If this option is enabled, the guest will be isolated, i.e. it 3028 will not be able to contact the host and no guest IP packets 3029 will be routed over the host to the outside. This option does 3030 not affect any explicitly set forwarding rules. 3031 3032 ``hostname=name`` 3033 Specifies the client hostname reported by the built-in DHCP 3034 server. 3035 3036 ``dhcpstart=addr`` 3037 Specify the first of the 16 IPs the built-in DHCP server can 3038 assign. Default is the 15th to 31st IP in the guest network, 3039 i.e. x.x.x.15 to x.x.x.31. 3040 3041 ``dns=addr`` 3042 Specify the guest-visible address of the virtual nameserver. The 3043 address must be different from the host address. Default is the 3044 3rd IP in the guest network, i.e. x.x.x.3. 3045 3046 ``ipv6-dns=addr`` 3047 Specify the guest-visible address of the IPv6 virtual 3048 nameserver. The address must be different from the host address. 3049 Default is the 3rd IP in the guest network, i.e. xxxx::3. 3050 3051 ``dnssearch=domain`` 3052 Provides an entry for the domain-search list sent by the 3053 built-in DHCP server. More than one domain suffix can be 3054 transmitted by specifying this option multiple times. If 3055 supported, this will cause the guest to automatically try to 3056 append the given domain suffix(es) in case a domain name can not 3057 be resolved. 3058 3059 Example: 3060 3061 .. parsed-literal:: 3062 3063 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 3064 3065 ``domainname=domain`` 3066 Specifies the client domain name reported by the built-in DHCP 3067 server. 3068 3069 ``tftp=dir`` 3070 When using the user mode network stack, activate a built-in TFTP 3071 server. The files in dir will be exposed as the root of a TFTP 3072 server. The TFTP client on the guest must be configured in 3073 binary mode (use the command ``bin`` of the Unix TFTP client). 3074 3075 ``tftp-server-name=name`` 3076 In BOOTP reply, broadcast name as the "TFTP server name" 3077 (RFC2132 option 66). This can be used to advise the guest to 3078 load boot files or configurations from a different server than 3079 the host address. 3080 3081 ``bootfile=file`` 3082 When using the user mode network stack, broadcast file as the 3083 BOOTP filename. In conjunction with ``tftp``, this can be used 3084 to network boot a guest from a local directory. 3085 3086 Example (using pxelinux): 3087 3088 .. parsed-literal:: 3089 3090 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\ 3091 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 3092 3093 ``smb=dir[,smbserver=addr]`` 3094 When using the user mode network stack, activate a built-in SMB 3095 server so that Windows OSes can access to the host files in 3096 ``dir`` transparently. The IP address of the SMB server can be 3097 set to addr. By default the 4th IP in the guest network is used, 3098 i.e. x.x.x.4. 3099 3100 In the guest Windows OS, the line: 3101 3102 :: 3103 3104 10.0.2.4 smbserver 3105 3106 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows 3107 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows 3108 NT/2000). 3109 3110 Then ``dir`` can be accessed in ``\\smbserver\qemu``. 3111 3112 Note that a SAMBA server must be installed on the host OS. 3113 3114 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport`` 3115 Redirect incoming TCP or UDP connections to the host port 3116 hostport to the guest IP address guestaddr on guest port 3117 guestport. If guestaddr is not specified, its value is x.x.x.15 3118 (default first address given by the built-in DHCP server). By 3119 specifying hostaddr, the rule can be bound to a specific host 3120 interface. If no connection type is set, TCP is used. This 3121 option can be given multiple times. 3122 3123 For example, to redirect host X11 connection from screen 1 to 3124 guest screen 0, use the following: 3125 3126 .. parsed-literal:: 3127 3128 # on the host 3129 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 3130 # this host xterm should open in the guest X11 server 3131 xterm -display :1 3132 3133 To redirect telnet connections from host port 5555 to telnet 3134 port on the guest, use the following: 3135 3136 .. parsed-literal:: 3137 3138 # on the host 3139 |qemu_system| -nic user,hostfwd=tcp::5555-:23 3140 telnet localhost 5555 3141 3142 Then when you use on the host ``telnet localhost 5555``, you 3143 connect to the guest telnet server. 3144 3145 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command`` 3146 Forward guest TCP connections to the IP address server on port 3147 port to the character device dev or to a program executed by 3148 cmd:command which gets spawned for each connection. This option 3149 can be given multiple times. 3150 3151 You can either use a chardev directly and have that one used 3152 throughout QEMU's lifetime, like in the following example: 3153 3154 .. parsed-literal:: 3155 3156 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 3157 # the guest accesses it 3158 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 3159 3160 Or you can execute a command on every TCP connection established 3161 by the guest, so that QEMU behaves similar to an inetd process 3162 for that virtual server: 3163 3164 .. parsed-literal:: 3165 3166 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 3167 # and connect the TCP stream to its stdin/stdout 3168 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 3169 3170``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` 3171 Configure a host TAP network backend with ID id. 3172 3173 Use the network script file to configure it and the network script 3174 dfile to deconfigure it. If name is not provided, the OS 3175 automatically provides one. The default network configure script is 3176 ``/etc/qemu-ifup`` and the default network deconfigure script is 3177 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to 3178 disable script execution. 3179 3180 If running QEMU as an unprivileged user, use the network helper 3181 to configure the TAP interface and attach it to the bridge. 3182 The default network helper executable is 3183 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3184 ``br0``. 3185 3186 ``fd``\ =h can be used to specify the handle of an already opened 3187 host TAP interface. 3188 3189 Examples: 3190 3191 .. parsed-literal:: 3192 3193 #launch a QEMU instance with the default network script 3194 |qemu_system| linux.img -nic tap 3195 3196 .. parsed-literal:: 3197 3198 #launch a QEMU instance with two NICs, each one connected 3199 #to a TAP device 3200 |qemu_system| linux.img \\ 3201 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\ 3202 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 3203 3204 .. parsed-literal:: 3205 3206 #launch a QEMU instance with the default network helper to 3207 #connect a TAP device to bridge br0 3208 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3209 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 3210 3211``-netdev bridge,id=id[,br=bridge][,helper=helper]`` 3212 Connect a host TAP network interface to a host bridge device. 3213 3214 Use the network helper helper to configure the TAP interface and 3215 attach it to the bridge. The default network helper executable is 3216 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3217 ``br0``. 3218 3219 Examples: 3220 3221 .. parsed-literal:: 3222 3223 #launch a QEMU instance with the default network helper to 3224 #connect a TAP device to bridge br0 3225 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 3226 3227 .. parsed-literal:: 3228 3229 #launch a QEMU instance with the default network helper to 3230 #connect a TAP device to bridge qemubr0 3231 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 3232 3233``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]`` 3234 This host network backend can be used to connect the guest's network 3235 to another QEMU virtual machine using a TCP socket connection. If 3236 ``listen`` is specified, QEMU waits for incoming connections on port 3237 (host is optional). ``connect`` is used to connect to another QEMU 3238 instance using the ``listen`` option. ``fd``\ =h specifies an 3239 already opened TCP socket. 3240 3241 Example: 3242 3243 .. parsed-literal:: 3244 3245 # launch a first QEMU instance 3246 |qemu_system| linux.img \\ 3247 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3248 -netdev socket,id=n1,listen=:1234 3249 # connect the network of this instance to the network of the first instance 3250 |qemu_system| linux.img \\ 3251 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3252 -netdev socket,id=n2,connect=127.0.0.1:1234 3253 3254``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]`` 3255 Configure a socket host network backend to share the guest's network 3256 traffic with another QEMU virtual machines using a UDP multicast 3257 socket, effectively making a bus for every QEMU with same multicast 3258 address maddr and port. NOTES: 3259 3260 1. Several QEMU can be running on different hosts and share same bus 3261 (assuming correct multicast setup for these hosts). 3262 3263 2. mcast support is compatible with User Mode Linux (argument 3264 ``ethN=mcast``), see http://user-mode-linux.sf.net. 3265 3266 3. Use ``fd=h`` to specify an already opened UDP multicast socket. 3267 3268 Example: 3269 3270 .. parsed-literal:: 3271 3272 # launch one QEMU instance 3273 |qemu_system| linux.img \\ 3274 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3275 -netdev socket,id=n1,mcast=230.0.0.1:1234 3276 # launch another QEMU instance on same "bus" 3277 |qemu_system| linux.img \\ 3278 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3279 -netdev socket,id=n2,mcast=230.0.0.1:1234 3280 # launch yet another QEMU instance on same "bus" 3281 |qemu_system| linux.img \\ 3282 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\ 3283 -netdev socket,id=n3,mcast=230.0.0.1:1234 3284 3285 Example (User Mode Linux compat.): 3286 3287 .. parsed-literal:: 3288 3289 # launch QEMU instance (note mcast address selected is UML's default) 3290 |qemu_system| linux.img \\ 3291 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3292 -netdev socket,id=n1,mcast=239.192.168.1:1102 3293 # launch UML 3294 /path/to/linux ubd0=/path/to/root_fs eth0=mcast 3295 3296 Example (send packets from host's 1.2.3.4): 3297 3298 .. parsed-literal:: 3299 3300 |qemu_system| linux.img \\ 3301 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3302 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 3303 3304``-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]`` 3305 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931) 3306 is a popular protocol to transport Ethernet (and other Layer 2) data 3307 frames between two systems. It is present in routers, firewalls and 3308 the Linux kernel (from version 3.3 onwards). 3309 3310 This transport allows a VM to communicate to another VM, router or 3311 firewall directly. 3312 3313 ``src=srcaddr`` 3314 source address (mandatory) 3315 3316 ``dst=dstaddr`` 3317 destination address (mandatory) 3318 3319 ``udp`` 3320 select udp encapsulation (default is ip). 3321 3322 ``srcport=srcport`` 3323 source udp port. 3324 3325 ``dstport=dstport`` 3326 destination udp port. 3327 3328 ``ipv6`` 3329 force v6, otherwise defaults to v4. 3330 3331 ``rxcookie=rxcookie``; \ ``txcookie=txcookie`` 3332 Cookies are a weak form of security in the l2tpv3 specification. 3333 Their function is mostly to prevent misconfiguration. By default 3334 they are 32 bit. 3335 3336 ``cookie64`` 3337 Set cookie size to 64 bit instead of the default 32 3338 3339 ``counter=off`` 3340 Force a 'cut-down' L2TPv3 with no counter as in 3341 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 3342 3343 ``pincounter=on`` 3344 Work around broken counter handling in peer. This may also help 3345 on networks which have packet reorder. 3346 3347 ``offset=offset`` 3348 Add an extra offset between header and data 3349 3350 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to 3351 the bridge br-lan on the remote Linux host 1.2.3.4: 3352 3353 .. parsed-literal:: 3354 3355 # Setup tunnel on linux host using raw ip as encapsulation 3356 # on 1.2.3.4 3357 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\ 3358 encap udp udp_sport 16384 udp_dport 16384 3359 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\ 3360 0xFFFFFFFF peer_session_id 0xFFFFFFFF 3361 ifconfig vmtunnel0 mtu 1500 3362 ifconfig vmtunnel0 up 3363 brctl addif br-lan vmtunnel0 3364 3365 3366 # on 4.3.2.1 3367 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 3368 3369 |qemu_system| linux.img -device e1000,netdev=n1 \\ 3370 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 3371 3372``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]`` 3373 Configure VDE backend to connect to PORT n of a vde switch running 3374 on host and listening for incoming connections on socketpath. Use 3375 GROUP groupname and MODE octalmode to change default ownership and 3376 permissions for communication port. This option is only available if 3377 QEMU has been compiled with vde support enabled. 3378 3379 Example: 3380 3381 .. parsed-literal:: 3382 3383 # launch vde switch 3384 vde_switch -F -sock /tmp/myswitch 3385 # launch QEMU instance 3386 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch 3387 3388``-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off][,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]`` 3389 Configure AF_XDP backend to connect to a network interface 'name' 3390 using AF_XDP socket. A specific program attach mode for a default 3391 XDP program can be forced with 'mode', defaults to best-effort, 3392 where the likely most performant mode will be in use. Number of queues 3393 'n' should generally match the number or queues in the interface, 3394 defaults to 1. Traffic arriving on non-configured device queues will 3395 not be delivered to the network backend. 3396 3397 .. parsed-literal:: 3398 3399 # set number of queues to 4 3400 ethtool -L eth0 combined 4 3401 # launch QEMU instance 3402 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3403 -netdev af-xdp,id=n1,ifname=eth0,queues=4 3404 3405 'start-queue' option can be specified if a particular range of queues 3406 [m, m + n] should be in use. For example, this is may be necessary in 3407 order to use certain NICs in native mode. Kernel allows the driver to 3408 create a separate set of XDP queues on top of regular ones, and only 3409 these queues can be used for AF_XDP sockets. NICs that work this way 3410 may also require an additional traffic redirection with ethtool to these 3411 special queues. 3412 3413 .. parsed-literal:: 3414 3415 # set number of queues to 1 3416 ethtool -L eth0 combined 1 3417 # redirect all the traffic to the second queue (id: 1) 3418 # note: drivers may require non-empty key/mask pair. 3419 ethtool -N eth0 flow-type ether \\ 3420 dst 00:00:00:00:00:00 m FF:FF:FF:FF:FF:FE action 1 3421 ethtool -N eth0 flow-type ether \\ 3422 dst 00:00:00:00:00:01 m FF:FF:FF:FF:FF:FE action 1 3423 # launch QEMU instance 3424 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3425 -netdev af-xdp,id=n1,ifname=eth0,queues=1,start-queue=1 3426 3427 XDP program can also be loaded externally. In this case 'inhibit' option 3428 should be set to 'on' and 'sock-fds' provided with file descriptors for 3429 already open but not bound XDP sockets already added to a socket map for 3430 corresponding queues. One socket per queue. 3431 3432 .. parsed-literal:: 3433 3434 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3435 -netdev af-xdp,id=n1,ifname=eth0,queues=3,inhibit=on,sock-fds=15:16:17 3436 3437``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` 3438 Establish a vhost-user netdev, backed by a chardev id. The chardev 3439 should be a unix domain socket backed one. The vhost-user uses a 3440 specifically defined protocol to pass vhost ioctl replacement 3441 messages to an application on the other end of the socket. On 3442 non-MSIX guests, the feature can be forced with vhostforce. Use 3443 'queues=n' to specify the number of queues to be created for 3444 multiqueue vhost-user. 3445 3446 Example: 3447 3448 :: 3449 3450 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 3451 -numa node,memdev=mem \ 3452 -chardev socket,id=chr0,path=/path/to/socket \ 3453 -netdev type=vhost-user,id=net0,chardev=chr0 \ 3454 -device virtio-net-pci,netdev=net0 3455 3456``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]`` 3457 Establish a vhost-vdpa netdev. 3458 3459 vDPA device is a device that uses a datapath which complies with 3460 the virtio specifications with a vendor specific control path. 3461 vDPA devices can be both physically located on the hardware or 3462 emulated by software. 3463 3464``-netdev hubport,id=id,hubid=hubid[,netdev=nd]`` 3465 Create a hub port on the emulated hub with ID hubid. 3466 3467 The hubport netdev lets you connect a NIC to a QEMU emulated hub 3468 instead of a single netdev. Alternatively, you can also connect the 3469 hubport to another netdev with ID nd by using the ``netdev=nd`` 3470 option. 3471 3472``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]`` 3473 Legacy option to configure or create an on-board (or machine 3474 default) Network Interface Card(NIC) and connect it either to the 3475 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd. 3476 If model is omitted, then the default NIC model associated with the 3477 machine type is used. Note that the default NIC model may change in 3478 future QEMU releases, so it is highly recommended to always specify 3479 a model. Optionally, the MAC address can be changed to mac, the 3480 device address set to addr (PCI cards only), and a name can be 3481 assigned for use in monitor commands. Optionally, for PCI cards, you 3482 can specify the number v of MSI-X vectors that the card should have; 3483 this option currently only affects virtio cards; set v = 0 to 3484 disable MSI-X. If no ``-net`` option is specified, a single NIC is 3485 created. QEMU can emulate several different models of network card. 3486 Use ``-net nic,model=help`` for a list of available devices for your 3487 target. 3488 3489``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]`` 3490 Configure a host network backend (with the options corresponding to 3491 the same ``-netdev`` option) and connect it to the emulated hub 0 3492 (the default hub). Use name to specify the name of the hub port. 3493ERST 3494 3495DEFHEADING() 3496 3497DEFHEADING(Character device options:) 3498 3499DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 3500 "-chardev help\n" 3501 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3502 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n" 3503 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" 3504 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 3505 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" 3506 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" 3507 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 3508 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n" 3509 " [,logfile=PATH][,logappend=on|off]\n" 3510 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3511 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 3512 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3513 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 3514 "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3515 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3516#ifdef _WIN32 3517 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3518 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3519#else 3520 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3521 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 3522#endif 3523#ifdef CONFIG_BRLAPI 3524 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3525#endif 3526#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 3527 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 3528 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3529#endif 3530#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 3531 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3532#endif 3533#if defined(CONFIG_SPICE) 3534 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3535 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3536#endif 3537 , QEMU_ARCH_ALL 3538) 3539 3540SRST 3541The general form of a character device option is: 3542 3543``-chardev backend,id=id[,mux=on|off][,options]`` 3544 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, 3545 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, 3546 ``pty``, ``stdio``, ``braille``, ``parallel``, 3547 ``spicevmc``, ``spiceport``. The specific backend will determine the 3548 applicable options. 3549 3550 Use ``-chardev help`` to print all available chardev backend types. 3551 3552 All devices must have an id, which can be any string up to 127 3553 characters long. It is used to uniquely identify this device in 3554 other command line directives. 3555 3556 A character device may be used in multiplexing mode by multiple 3557 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is 3558 a "1:N" device, and here the "1" end is your specified chardev 3559 backend, and the "N" end is the various parts of QEMU that can talk 3560 to a chardev. If you create a chardev with ``id=myid`` and 3561 ``mux=on``, QEMU will create a multiplexer with your specified ID, 3562 and you can then configure multiple front ends to use that chardev 3563 ID for their input/output. Up to four different front ends can be 3564 connected to a single multiplexed chardev. (Without multiplexing 3565 enabled, a chardev can only be used by a single front end.) For 3566 instance you could use this to allow a single stdio chardev to be 3567 used by two serial ports and the QEMU monitor: 3568 3569 :: 3570 3571 -chardev stdio,mux=on,id=char0 \ 3572 -mon chardev=char0,mode=readline \ 3573 -serial chardev:char0 \ 3574 -serial chardev:char0 3575 3576 You can have more than one multiplexer in a system configuration; 3577 for instance you could have a TCP port multiplexed between UART 0 3578 and UART 1, and stdio multiplexed between the QEMU monitor and a 3579 parallel port: 3580 3581 :: 3582 3583 -chardev stdio,mux=on,id=char0 \ 3584 -mon chardev=char0,mode=readline \ 3585 -parallel chardev:char0 \ 3586 -chardev tcp,...,mux=on,id=char1 \ 3587 -serial chardev:char1 \ 3588 -serial chardev:char1 3589 3590 When you're using a multiplexed character device, some escape 3591 sequences are interpreted in the input. See the chapter about 3592 :ref:`keys in the character backend multiplexer` in the 3593 System Emulation Users Guide for more details. 3594 3595 Note that some other command line options may implicitly create 3596 multiplexed character backends; for instance ``-serial mon:stdio`` 3597 creates a multiplexed stdio backend connected to the serial port and 3598 the QEMU monitor, and ``-nographic`` also multiplexes the console 3599 and the monitor to stdio. 3600 3601 There is currently no support for multiplexing in the other 3602 direction (where a single QEMU front end takes input and output from 3603 multiple chardevs). 3604 3605 Every backend supports the ``logfile`` option, which supplies the 3606 path to a file to record all data transmitted via the backend. The 3607 ``logappend`` option controls whether the log file will be truncated 3608 or appended to when opened. 3609 3610The available backends are: 3611 3612``-chardev null,id=id`` 3613 A void device. This device will not emit any data, and will drop any 3614 data it receives. The null backend does not take any options. 3615 3616``-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]`` 3617 Create a two-way stream socket, which can be either a TCP or a unix 3618 socket. A unix socket will be created if ``path`` is specified. 3619 Behaviour is undefined if TCP options are specified for a unix 3620 socket. 3621 3622 ``server=on|off`` specifies that the socket shall be a listening socket. 3623 3624 ``wait=on|off`` specifies that QEMU should not block waiting for a client 3625 to connect to a listening socket. 3626 3627 ``telnet=on|off`` specifies that traffic on the socket should interpret 3628 telnet escape sequences. 3629 3630 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for 3631 communication. 3632 3633 ``reconnect`` sets the timeout for reconnecting on non-server 3634 sockets when the remote end goes away. qemu will delay this many 3635 seconds and then attempt to reconnect. Zero disables reconnecting, 3636 and is the default. 3637 3638 ``tls-creds`` requests enablement of the TLS protocol for 3639 encryption, and specifies the id of the TLS credentials to use for 3640 the handshake. The credentials must be previously created with the 3641 ``-object tls-creds`` argument. 3642 3643 ``tls-auth`` provides the ID of the QAuthZ authorization object 3644 against which the client's x509 distinguished name will be 3645 validated. This object is only resolved at time of use, so can be 3646 deleted and recreated on the fly while the chardev server is active. 3647 If missing, it will default to denying access. 3648 3649 TCP and unix socket options are given below: 3650 3651 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]`` 3652 ``host`` for a listening socket specifies the local address to 3653 be bound. For a connecting socket species the remote host to 3654 connect to. ``host`` is optional for listening sockets. If not 3655 specified it defaults to ``0.0.0.0``. 3656 3657 ``port`` for a listening socket specifies the local port to be 3658 bound. For a connecting socket specifies the port on the remote 3659 host to connect to. ``port`` can be given as either a port 3660 number or a service name. ``port`` is required. 3661 3662 ``to`` is only relevant to listening sockets. If it is 3663 specified, and ``port`` cannot be bound, QEMU will attempt to 3664 bind to subsequent ports up to and including ``to`` until it 3665 succeeds. ``to`` must be specified as a port number. 3666 3667 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 3668 or IPv6 must be used. If neither is specified the socket may 3669 use either protocol. 3670 3671 ``nodelay=on|off`` disables the Nagle algorithm. 3672 3673 ``unix options: path=path[,abstract=on|off][,tight=on|off]`` 3674 ``path`` specifies the local path of the unix socket. ``path`` 3675 is required. 3676 ``abstract=on|off`` specifies the use of the abstract socket namespace, 3677 rather than the filesystem. Optional, defaults to false. 3678 ``tight=on|off`` sets the socket length of abstract sockets to their minimum, 3679 rather than the full sun_path length. Optional, defaults to true. 3680 3681``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4=on|off][,ipv6=on|off]`` 3682 Sends all traffic from the guest to a remote host over UDP. 3683 3684 ``host`` specifies the remote host to connect to. If not specified 3685 it defaults to ``localhost``. 3686 3687 ``port`` specifies the port on the remote host to connect to. 3688 ``port`` is required. 3689 3690 ``localaddr`` specifies the local address to bind to. If not 3691 specified it defaults to ``0.0.0.0``. 3692 3693 ``localport`` specifies the local port to bind to. If not specified 3694 any available local port will be used. 3695 3696 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used. 3697 If neither is specified the device may use either protocol. 3698 3699``-chardev msmouse,id=id`` 3700 Forward QEMU's emulated msmouse events to the guest. ``msmouse`` 3701 does not take any options. 3702 3703``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` 3704 Connect to a QEMU text console. ``vc`` may optionally be given a 3705 specific size. 3706 3707 ``width`` and ``height`` specify the width and height respectively 3708 of the console, in pixels. 3709 3710 ``cols`` and ``rows`` specify that the console be sized to fit a 3711 text console with the given dimensions. 3712 3713``-chardev ringbuf,id=id[,size=size]`` 3714 Create a ring buffer with fixed size ``size``. size must be a power 3715 of two and defaults to ``64K``. 3716 3717``-chardev file,id=id,path=path[,input-path=input-path]`` 3718 Log all traffic received from the guest to a file. 3719 3720 ``path`` specifies the path of the file to be opened. This file will 3721 be created if it does not already exist, and overwritten if it does. 3722 ``path`` is required. 3723 3724 If ``input-path`` is specified, this is the path of a second file 3725 which will be used for input. If ``input-path`` is not specified, 3726 no input will be available from the chardev. 3727 3728 Note that ``input-path`` is not supported on Windows hosts. 3729 3730``-chardev pipe,id=id,path=path`` 3731 Create a two-way connection to the guest. The behaviour differs 3732 slightly between Windows hosts and other hosts: 3733 3734 On Windows, a single duplex pipe will be created at 3735 ``\\.pipe\path``. 3736 3737 On other hosts, 2 pipes will be created called ``path.in`` and 3738 ``path.out``. Data written to ``path.in`` will be received by the 3739 guest. Data written by the guest can be read from ``path.out``. QEMU 3740 will not create these fifos, and requires them to be present. 3741 3742 ``path`` forms part of the pipe path as described above. ``path`` is 3743 required. 3744 3745``-chardev console,id=id`` 3746 Send traffic from the guest to QEMU's standard output. ``console`` 3747 does not take any options. 3748 3749 ``console`` is only available on Windows hosts. 3750 3751``-chardev serial,id=id,path=path`` 3752 Send traffic from the guest to a serial device on the host. 3753 3754 On Unix hosts serial will actually accept any tty device, not only 3755 serial lines. 3756 3757 ``path`` specifies the name of the serial device to open. 3758 3759``-chardev pty,id=id`` 3760 Create a new pseudo-terminal on the host and connect to it. ``pty`` 3761 does not take any options. 3762 3763 ``pty`` is not available on Windows hosts. 3764 3765``-chardev stdio,id=id[,signal=on|off]`` 3766 Connect to standard input and standard output of the QEMU process. 3767 3768 ``signal`` controls if signals are enabled on the terminal, that 3769 includes exiting QEMU with the key sequence Control-c. This option 3770 is enabled by default, use ``signal=off`` to disable it. 3771 3772``-chardev braille,id=id`` 3773 Connect to a local BrlAPI server. ``braille`` does not take any 3774 options. 3775 3776``-chardev parallel,id=id,path=path`` 3777 \ 3778 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD 3779 hosts. 3780 3781 Connect to a local parallel port. 3782 3783 ``path`` specifies the path to the parallel port device. ``path`` is 3784 required. 3785 3786``-chardev spicevmc,id=id,debug=debug,name=name`` 3787 ``spicevmc`` is only available when spice support is built in. 3788 3789 ``debug`` debug level for spicevmc 3790 3791 ``name`` name of spice channel to connect to 3792 3793 Connect to a spice virtual machine channel, such as vdiport. 3794 3795``-chardev spiceport,id=id,debug=debug,name=name`` 3796 ``spiceport`` is only available when spice support is built in. 3797 3798 ``debug`` debug level for spicevmc 3799 3800 ``name`` name of spice port to connect to 3801 3802 Connect to a spice port, allowing a Spice client to handle the 3803 traffic identified by a name (preferably a fqdn). 3804ERST 3805 3806DEFHEADING() 3807 3808#ifdef CONFIG_TPM 3809DEFHEADING(TPM device options:) 3810 3811DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3812 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3813 " use path to provide path to a character device; default is /dev/tpm0\n" 3814 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3815 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3816 "-tpmdev emulator,id=id,chardev=dev\n" 3817 " configure the TPM device using chardev backend\n", 3818 QEMU_ARCH_ALL) 3819SRST 3820The general form of a TPM device option is: 3821 3822``-tpmdev backend,id=id[,options]`` 3823 The specific backend type will determine the applicable options. The 3824 ``-tpmdev`` option creates the TPM backend and requires a 3825 ``-device`` option that specifies the TPM frontend interface model. 3826 3827 Use ``-tpmdev help`` to print all available TPM backend types. 3828 3829The available backends are: 3830 3831``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path`` 3832 (Linux-host only) Enable access to the host's TPM using the 3833 passthrough driver. 3834 3835 ``path`` specifies the path to the host's TPM device, i.e., on a 3836 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by 3837 default ``/dev/tpm0`` is used. 3838 3839 ``cancel-path`` specifies the path to the host TPM device's sysfs 3840 entry allowing for cancellation of an ongoing TPM command. 3841 ``cancel-path`` is optional and by default QEMU will search for the 3842 sysfs entry to use. 3843 3844 Some notes about using the host's TPM with the passthrough driver: 3845 3846 The TPM device accessed by the passthrough driver must not be used 3847 by any other application on the host. 3848 3849 Since the host's firmware (BIOS/UEFI) has already initialized the 3850 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize 3851 the TPM again and may therefore not show a TPM-specific menu that 3852 would otherwise allow the user to configure the TPM, e.g., allow the 3853 user to enable/disable or activate/deactivate the TPM. Further, if 3854 TPM ownership is released from within a VM then the host's TPM will 3855 get disabled and deactivated. To enable and activate the TPM again 3856 afterwards, the host has to be rebooted and the user is required to 3857 enter the firmware's menu to enable and activate the TPM. If the TPM 3858 is left disabled and/or deactivated most TPM commands will fail. 3859 3860 To create a passthrough TPM use the following two options: 3861 3862 :: 3863 3864 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3865 3866 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by 3867 ``tpmdev=tpm0`` in the device option. 3868 3869``-tpmdev emulator,id=id,chardev=dev`` 3870 (Linux-host only) Enable access to a TPM emulator using Unix domain 3871 socket based chardev backend. 3872 3873 ``chardev`` specifies the unique ID of a character device backend 3874 that provides connection to the software TPM server. 3875 3876 To create a TPM emulator backend device with chardev socket backend: 3877 3878 :: 3879 3880 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3881ERST 3882 3883DEFHEADING() 3884 3885#endif 3886 3887DEFHEADING(Boot Image or Kernel specific:) 3888SRST 3889There are broadly 4 ways you can boot a system with QEMU. 3890 3891 - specify a firmware and let it control finding a kernel 3892 - specify a firmware and pass a hint to the kernel to boot 3893 - direct kernel image boot 3894 - manually load files into the guest's address space 3895 3896The third method is useful for quickly testing kernels but as there is 3897no firmware to pass configuration information to the kernel the 3898hardware must either be probeable, the kernel built for the exact 3899configuration or passed some configuration data (e.g. a DTB blob) 3900which tells the kernel what drivers it needs. This exact details are 3901often hardware specific. 3902 3903The final method is the most generic way of loading images into the 3904guest address space and used mostly for ``bare metal`` type 3905development where the reset vectors of the processor are taken into 3906account. 3907 3908ERST 3909 3910SRST 3911 3912For x86 machines and some other architectures ``-bios`` will generally 3913do the right thing with whatever it is given. For other machines the 3914more strict ``-pflash`` option needs an image that is sized for the 3915flash device for the given machine type. 3916 3917Please see the :ref:`system-targets-ref` section of the manual for 3918more detailed documentation. 3919 3920ERST 3921 3922DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3923 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3924SRST 3925``-bios file`` 3926 Set the filename for the BIOS. 3927ERST 3928 3929DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 3930 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 3931SRST 3932``-pflash file`` 3933 Use file as a parallel flash image. 3934ERST 3935 3936SRST 3937 3938The kernel options were designed to work with Linux kernels although 3939other things (like hypervisors) can be packaged up as a kernel 3940executable image. The exact format of a executable image is usually 3941architecture specific. 3942 3943The way in which the kernel is started (what address it is loaded at, 3944what if any information is passed to it via CPU registers, the state 3945of the hardware when it is started, and so on) is also architecture 3946specific. Typically it follows the specification laid down by the 3947Linux kernel for how kernels for that architecture must be started. 3948 3949ERST 3950 3951DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3952 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3953SRST 3954``-kernel bzImage`` 3955 Use bzImage as kernel image. The kernel can be either a Linux kernel 3956 or in multiboot format. 3957ERST 3958 3959DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3960 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3961SRST 3962``-append cmdline`` 3963 Use cmdline as kernel command line 3964ERST 3965 3966DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3967 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3968SRST 3969``-initrd file`` 3970 Use file as initial ram disk. 3971 3972``-initrd "file1 arg=foo,file2"`` 3973 This syntax is only available with multiboot. 3974 3975 Use file1 and file2 as modules and pass arg=foo as parameter to the 3976 first module. 3977ERST 3978 3979DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3980 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3981SRST 3982``-dtb file`` 3983 Use file as a device tree binary (dtb) image and pass it to the 3984 kernel on boot. 3985ERST 3986 3987SRST 3988 3989Finally you can also manually load images directly into the address 3990space of the guest. This is most useful for developers who already 3991know the layout of their guest and take care to ensure something sane 3992will happen when the reset vector executes. 3993 3994The generic loader can be invoked by using the loader device: 3995 3996``-device loader,addr=<addr>,data=<data>,data-len=<data-len>[,data-be=<data-be>][,cpu-num=<cpu-num>]`` 3997 3998there is also the guest loader which operates in a similar way but 3999tweaks the DTB so a hypervisor loaded via ``-kernel`` can find where 4000the guest image is: 4001 4002``-device guest-loader,addr=<addr>[,kernel=<path>,[bootargs=<arguments>]][,initrd=<path>]`` 4003 4004ERST 4005 4006DEFHEADING() 4007 4008DEFHEADING(Debug/Expert options:) 4009 4010DEF("compat", HAS_ARG, QEMU_OPTION_compat, 4011 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n" 4012 " Policy for handling deprecated management interfaces\n" 4013 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n" 4014 " Policy for handling unstable management interfaces\n", 4015 QEMU_ARCH_ALL) 4016SRST 4017``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]`` 4018 Set policy for handling deprecated management interfaces (experimental): 4019 4020 ``deprecated-input=accept`` (default) 4021 Accept deprecated commands and arguments 4022 ``deprecated-input=reject`` 4023 Reject deprecated commands and arguments 4024 ``deprecated-input=crash`` 4025 Crash on deprecated commands and arguments 4026 ``deprecated-output=accept`` (default) 4027 Emit deprecated command results and events 4028 ``deprecated-output=hide`` 4029 Suppress deprecated command results and events 4030 4031 Limitation: covers only syntactic aspects of QMP. 4032 4033``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]`` 4034 Set policy for handling unstable management interfaces (experimental): 4035 4036 ``unstable-input=accept`` (default) 4037 Accept unstable commands and arguments 4038 ``unstable-input=reject`` 4039 Reject unstable commands and arguments 4040 ``unstable-input=crash`` 4041 Crash on unstable commands and arguments 4042 ``unstable-output=accept`` (default) 4043 Emit unstable command results and events 4044 ``unstable-output=hide`` 4045 Suppress unstable command results and events 4046 4047 Limitation: covers only syntactic aspects of QMP. 4048ERST 4049 4050DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 4051 "-fw_cfg [name=]<name>,file=<file>\n" 4052 " add named fw_cfg entry with contents from file\n" 4053 "-fw_cfg [name=]<name>,string=<str>\n" 4054 " add named fw_cfg entry with contents from string\n", 4055 QEMU_ARCH_ALL) 4056SRST 4057``-fw_cfg [name=]name,file=file`` 4058 Add named fw\_cfg entry with contents from file file. 4059 4060``-fw_cfg [name=]name,string=str`` 4061 Add named fw\_cfg entry with contents from string str. 4062 4063 The terminating NUL character of the contents of str will not be 4064 included as part of the fw\_cfg item data. To insert contents with 4065 embedded NUL characters, you have to use the file parameter. 4066 4067 The fw\_cfg entries are passed by QEMU through to the guest. 4068 4069 Example: 4070 4071 :: 4072 4073 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 4074 4075 creates an fw\_cfg entry named opt/com.mycompany/blob with contents 4076 from ./my\_blob.bin. 4077ERST 4078 4079DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 4080 "-serial dev redirect the serial port to char device 'dev'\n", 4081 QEMU_ARCH_ALL) 4082SRST 4083``-serial dev`` 4084 Redirect the virtual serial port to host character device dev. The 4085 default device is ``vc`` in graphical mode and ``stdio`` in non 4086 graphical mode. 4087 4088 This option can be used several times to simulate up to 4 serial 4089 ports. 4090 4091 Use ``-serial none`` to disable all serial ports. 4092 4093 Available character devices are: 4094 4095 ``vc[:WxH]`` 4096 Virtual console. Optionally, a width and height can be given in 4097 pixel with 4098 4099 :: 4100 4101 vc:800x600 4102 4103 It is also possible to specify width or height in characters: 4104 4105 :: 4106 4107 vc:80Cx24C 4108 4109 ``pty`` 4110 [Linux only] Pseudo TTY (a new PTY is automatically allocated) 4111 4112 ``none`` 4113 No device is allocated. 4114 4115 ``null`` 4116 void device 4117 4118 ``chardev:id`` 4119 Use a named character device defined with the ``-chardev`` 4120 option. 4121 4122 ``/dev/XXX`` 4123 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial 4124 port parameters are set according to the emulated ones. 4125 4126 ``/dev/parportN`` 4127 [Linux only, parallel port only] Use host parallel port N. 4128 Currently SPP and EPP parallel port features can be used. 4129 4130 ``file:filename`` 4131 Write output to filename. No character can be read. 4132 4133 ``stdio`` 4134 [Unix only] standard input/output 4135 4136 ``pipe:filename`` 4137 name pipe filename 4138 4139 ``COMn`` 4140 [Windows only] Use host serial port n 4141 4142 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]`` 4143 This implements UDP Net Console. When remote\_host or src\_ip 4144 are not specified they default to ``0.0.0.0``. When not using a 4145 specified src\_port a random port is automatically chosen. 4146 4147 If you just want a simple readonly console you can use 4148 ``netcat`` or ``nc``, by starting QEMU with: 4149 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time 4150 QEMU writes something to that port it will appear in the 4151 netconsole session. 4152 4153 If you plan to send characters back via netconsole or you want 4154 to stop and start QEMU a lot of times, you should have QEMU use 4155 the same source port each time by using something like ``-serial 4156 udp::4555@:4556`` to QEMU. Another approach is to use a patched 4157 version of netcat which can listen to a TCP port and send and 4158 receive characters via udp. If you have a patched version of 4159 netcat which activates telnet remote echo and single char 4160 transfer, then you can use the following options to set up a 4161 netcat redirector to allow telnet on port 5555 to access the 4162 QEMU port. 4163 4164 ``QEMU Options:`` 4165 -serial udp::4555@:4556 4166 4167 ``netcat options:`` 4168 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 4169 4170 ``telnet options:`` 4171 localhost 5555 4172 4173 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]`` 4174 The TCP Net Console has two modes of operation. It can send the 4175 serial I/O to a location or wait for a connection from a 4176 location. By default the TCP Net Console is sent to host at the 4177 port. If you use the ``server=on`` option QEMU will wait for a client 4178 socket application to connect to the port before continuing, 4179 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off`` 4180 option disables the Nagle buffering algorithm. The ``reconnect=on`` 4181 option only applies if ``server=no`` is set, if the connection goes 4182 down it will attempt to reconnect at the given interval. If host 4183 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a 4184 time is accepted. You can use ``telnet=on`` to connect to the 4185 corresponding character device. 4186 4187 ``Example to send tcp console to 192.168.0.2 port 4444`` 4188 -serial tcp:192.168.0.2:4444 4189 4190 ``Example to listen and wait on port 4444 for connection`` 4191 -serial tcp::4444,server=on 4192 4193 ``Example to not wait and listen on ip 192.168.0.100 port 4444`` 4194 -serial tcp:192.168.0.100:4444,server=on,wait=off 4195 4196 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]`` 4197 The telnet protocol is used instead of raw tcp sockets. The 4198 options work the same as if you had specified ``-serial tcp``. 4199 The difference is that the port acts like a telnet server or 4200 client using telnet option negotiation. This will also allow you 4201 to send the MAGIC\_SYSRQ sequence if you use a telnet that 4202 supports sending the break sequence. Typically in unix telnet 4203 you do it with Control-] and then type "send break" followed by 4204 pressing the enter key. 4205 4206 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]`` 4207 The WebSocket protocol is used instead of raw tcp socket. The 4208 port acts as a WebSocket server. Client mode is not supported. 4209 4210 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]`` 4211 A unix domain socket is used instead of a tcp socket. The option 4212 works the same as if you had specified ``-serial tcp`` except 4213 the unix domain socket path is used for connections. 4214 4215 ``mon:dev_string`` 4216 This is a special option to allow the monitor to be multiplexed 4217 onto another serial port. The monitor is accessed with key 4218 sequence of Control-a and then pressing c. dev\_string should be 4219 any one of the serial devices specified above. An example to 4220 multiplex the monitor onto a telnet server listening on port 4221 4444 would be: 4222 4223 ``-serial mon:telnet::4444,server=on,wait=off`` 4224 4225 When the monitor is multiplexed to stdio in this way, Ctrl+C 4226 will not terminate QEMU any more but will be passed to the guest 4227 instead. 4228 4229 ``braille`` 4230 Braille device. This will use BrlAPI to display the braille 4231 output on a real or fake device. 4232 4233 ``msmouse`` 4234 Three button serial mouse. Configure the guest to use Microsoft 4235 protocol. 4236ERST 4237 4238DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 4239 "-parallel dev redirect the parallel port to char device 'dev'\n", 4240 QEMU_ARCH_ALL) 4241SRST 4242``-parallel dev`` 4243 Redirect the virtual parallel port to host device dev (same devices 4244 as the serial port). On Linux hosts, ``/dev/parportN`` can be used 4245 to use hardware devices connected on the corresponding host parallel 4246 port. 4247 4248 This option can be used several times to simulate up to 3 parallel 4249 ports. 4250 4251 Use ``-parallel none`` to disable all parallel ports. 4252ERST 4253 4254DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 4255 "-monitor dev redirect the monitor to char device 'dev'\n", 4256 QEMU_ARCH_ALL) 4257SRST 4258``-monitor dev`` 4259 Redirect the monitor to host device dev (same devices as the serial 4260 port). The default device is ``vc`` in graphical mode and ``stdio`` 4261 in non graphical mode. Use ``-monitor none`` to disable the default 4262 monitor. 4263ERST 4264DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 4265 "-qmp dev like -monitor but opens in 'control' mode\n", 4266 QEMU_ARCH_ALL) 4267SRST 4268``-qmp dev`` 4269 Like ``-monitor`` but opens in 'control' mode. For example, to make 4270 QMP available on localhost port 4444:: 4271 4272 -qmp tcp:localhost:4444,server=on,wait=off 4273 4274 Not all options are configurable via this syntax; for maximum 4275 flexibility use the ``-mon`` option and an accompanying ``-chardev``. 4276 4277ERST 4278DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 4279 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 4280 QEMU_ARCH_ALL) 4281SRST 4282``-qmp-pretty dev`` 4283 Like ``-qmp`` but uses pretty JSON formatting. 4284ERST 4285 4286DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 4287 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 4288SRST 4289``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]`` 4290 Set up a monitor connected to the chardev ``name``. 4291 QEMU supports two monitors: the Human Monitor Protocol 4292 (HMP; for human interaction), and the QEMU Monitor Protocol 4293 (QMP; a JSON RPC-style protocol). 4294 The default is HMP; ``mode=control`` selects QMP instead. 4295 ``pretty`` is only valid when ``mode=control``, 4296 turning on JSON pretty printing to ease 4297 human reading and debugging. 4298 4299 For example:: 4300 4301 -chardev socket,id=mon1,host=localhost,port=4444,server=on,wait=off \ 4302 -mon chardev=mon1,mode=control,pretty=on 4303 4304 enables the QMP monitor on localhost port 4444 with pretty-printing. 4305ERST 4306 4307DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 4308 "-debugcon dev redirect the debug console to char device 'dev'\n", 4309 QEMU_ARCH_ALL) 4310SRST 4311``-debugcon dev`` 4312 Redirect the debug console to host device dev (same devices as the 4313 serial port). The debug console is an I/O port which is typically 4314 port 0xe9; writing to that I/O port sends output to this device. The 4315 default device is ``vc`` in graphical mode and ``stdio`` in non 4316 graphical mode. 4317ERST 4318 4319DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 4320 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 4321SRST 4322``-pidfile file`` 4323 Store the QEMU process PID in file. It is useful if you launch QEMU 4324 from a script. 4325ERST 4326 4327DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 4328 "-singlestep deprecated synonym for -accel tcg,one-insn-per-tb=on\n", QEMU_ARCH_ALL) 4329SRST 4330``-singlestep`` 4331 This is a deprecated synonym for the TCG accelerator property 4332 ``one-insn-per-tb``. 4333ERST 4334 4335DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 4336 "--preconfig pause QEMU before machine is initialized (experimental)\n", 4337 QEMU_ARCH_ALL) 4338SRST 4339``--preconfig`` 4340 Pause QEMU for interactive configuration before the machine is 4341 created, which allows querying and configuring properties that will 4342 affect machine initialization. Use QMP command 'x-exit-preconfig' to 4343 exit the preconfig state and move to the next state (i.e. run guest 4344 if -S isn't used or pause the second time if -S is used). This 4345 option is experimental. 4346ERST 4347 4348DEF("S", 0, QEMU_OPTION_S, \ 4349 "-S freeze CPU at startup (use 'c' to start execution)\n", 4350 QEMU_ARCH_ALL) 4351SRST 4352``-S`` 4353 Do not start CPU at startup (you must type 'c' in the monitor). 4354ERST 4355 4356DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 4357 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 4358 " run qemu with overcommit hints\n" 4359 " mem-lock=on|off controls memory lock support (default: off)\n" 4360 " cpu-pm=on|off controls cpu power management (default: off)\n", 4361 QEMU_ARCH_ALL) 4362SRST 4363``-overcommit mem-lock=on|off`` 4364 \ 4365``-overcommit cpu-pm=on|off`` 4366 Run qemu with hints about host resource overcommit. The default is 4367 to assume that host overcommits all resources. 4368 4369 Locking qemu and guest memory can be enabled via ``mem-lock=on`` 4370 (disabled by default). This works when host memory is not 4371 overcommitted and reduces the worst-case latency for guest. 4372 4373 Guest ability to manage power state of host cpus (increasing latency 4374 for other processes on the same host cpu, but decreasing latency for 4375 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This 4376 works best when host CPU is not overcommitted. When used, host 4377 estimates of CPU cycle and power utilization will be incorrect, not 4378 taking into account guest idle time. 4379ERST 4380 4381DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 4382 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n" 4383 " the guest without waiting for gdb to connect; use -S too\n" 4384 " if you want it to not start execution.)\n", 4385 QEMU_ARCH_ALL) 4386SRST 4387``-gdb dev`` 4388 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter 4389 in the System Emulation Users Guide). Note that this option does not pause QEMU 4390 execution -- if you want QEMU to not start the guest until you 4391 connect with gdb and issue a ``continue`` command, you will need to 4392 also pass the ``-S`` option to QEMU. 4393 4394 The most usual configuration is to listen on a local TCP socket:: 4395 4396 -gdb tcp::3117 4397 4398 but you can specify other backends; UDP, pseudo TTY, or even stdio 4399 are all reasonable use cases. For example, a stdio connection 4400 allows you to start QEMU from within gdb and establish the 4401 connection via a pipe: 4402 4403 .. parsed-literal:: 4404 4405 (gdb) target remote | exec |qemu_system| -gdb stdio ... 4406ERST 4407 4408DEF("s", 0, QEMU_OPTION_s, \ 4409 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 4410 QEMU_ARCH_ALL) 4411SRST 4412``-s`` 4413 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 4414 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide). 4415ERST 4416 4417DEF("d", HAS_ARG, QEMU_OPTION_d, \ 4418 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 4419 QEMU_ARCH_ALL) 4420SRST 4421``-d item1[,...]`` 4422 Enable logging of specified items. Use '-d help' for a list of log 4423 items. 4424ERST 4425 4426DEF("D", HAS_ARG, QEMU_OPTION_D, \ 4427 "-D logfile output log to logfile (default stderr)\n", 4428 QEMU_ARCH_ALL) 4429SRST 4430``-D logfile`` 4431 Output log in logfile instead of to stderr 4432ERST 4433 4434DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 4435 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 4436 QEMU_ARCH_ALL) 4437SRST 4438``-dfilter range1[,...]`` 4439 Filter debug output to that relevant to a range of target addresses. 4440 The filter spec can be either start+size, start-size or start..end 4441 where start end and size are the addresses and sizes required. For 4442 example: 4443 4444 :: 4445 4446 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 4447 4448 Will dump output for any code in the 0x1000 sized block starting at 4449 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and 4450 another 0x1000 sized block starting at 0xffffffc00005f000. 4451ERST 4452 4453DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 4454 "-seed number seed the pseudo-random number generator\n", 4455 QEMU_ARCH_ALL) 4456SRST 4457``-seed number`` 4458 Force the guest to use a deterministic pseudo-random number 4459 generator, seeded with number. This does not affect crypto routines 4460 within the host. 4461ERST 4462 4463DEF("L", HAS_ARG, QEMU_OPTION_L, \ 4464 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 4465 QEMU_ARCH_ALL) 4466SRST 4467``-L path`` 4468 Set the directory for the BIOS, VGA BIOS and keymaps. 4469 4470 To list all the data directories, use ``-L help``. 4471ERST 4472 4473DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 4474 "-enable-kvm enable KVM full virtualization support\n", 4475 QEMU_ARCH_ARM | QEMU_ARCH_I386 | QEMU_ARCH_MIPS | QEMU_ARCH_PPC | 4476 QEMU_ARCH_RISCV | QEMU_ARCH_S390X) 4477SRST 4478``-enable-kvm`` 4479 Enable KVM full virtualization support. This option is only 4480 available if KVM support is enabled when compiling. 4481ERST 4482 4483DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 4484 "-xen-domid id specify xen guest domain id\n", 4485 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4486DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 4487 "-xen-attach attach to existing xen domain\n" 4488 " libxl will use this when starting QEMU\n", 4489 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4490DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 4491 "-xen-domid-restrict restrict set of available xen operations\n" 4492 " to specified domain id. (Does not affect\n" 4493 " xenpv machine type).\n", 4494 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4495SRST 4496``-xen-domid id`` 4497 Specify xen guest domain id (XEN only). 4498 4499``-xen-attach`` 4500 Attach to existing xen domain. libxl will use this when starting 4501 QEMU (XEN only). Restrict set of available xen operations to 4502 specified domain id (XEN only). 4503ERST 4504 4505DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 4506 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 4507SRST 4508``-no-reboot`` 4509 Exit instead of rebooting. 4510ERST 4511 4512DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 4513 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 4514SRST 4515``-no-shutdown`` 4516 Don't exit QEMU on guest shutdown, but instead only stop the 4517 emulation. This allows for instance switching to monitor to commit 4518 changes to the disk image. 4519ERST 4520 4521DEF("action", HAS_ARG, QEMU_OPTION_action, 4522 "-action reboot=reset|shutdown\n" 4523 " action when guest reboots [default=reset]\n" 4524 "-action shutdown=poweroff|pause\n" 4525 " action when guest shuts down [default=poweroff]\n" 4526 "-action panic=pause|shutdown|exit-failure|none\n" 4527 " action when guest panics [default=shutdown]\n" 4528 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" 4529 " action when watchdog fires [default=reset]\n", 4530 QEMU_ARCH_ALL) 4531SRST 4532``-action event=action`` 4533 The action parameter serves to modify QEMU's default behavior when 4534 certain guest events occur. It provides a generic method for specifying the 4535 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown`` 4536 parameters. 4537 4538 Examples: 4539 4540 ``-action panic=none`` 4541 ``-action reboot=shutdown,shutdown=pause`` 4542 ``-device i6300esb -action watchdog=pause`` 4543 4544ERST 4545 4546DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 4547 "-loadvm [tag|id]\n" \ 4548 " start right away with a saved state (loadvm in monitor)\n", 4549 QEMU_ARCH_ALL) 4550SRST 4551``-loadvm file`` 4552 Start right away with a saved state (``loadvm`` in monitor) 4553ERST 4554 4555#ifndef _WIN32 4556DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 4557 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 4558#endif 4559SRST 4560``-daemonize`` 4561 Daemonize the QEMU process after initialization. QEMU will not 4562 detach from standard IO until it is ready to receive connections on 4563 any of its devices. This option is a useful way for external 4564 programs to launch QEMU without having to cope with initialization 4565 race conditions. 4566ERST 4567 4568DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 4569 "-option-rom rom load a file, rom, into the option ROM space\n", 4570 QEMU_ARCH_ALL) 4571SRST 4572``-option-rom file`` 4573 Load the contents of file as an option ROM. This option is useful to 4574 load things like EtherBoot. 4575ERST 4576 4577DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 4578 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 4579 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 4580 QEMU_ARCH_ALL) 4581 4582SRST 4583``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]`` 4584 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at 4585 the current UTC or local time, respectively. ``localtime`` is 4586 required for correct date in MS-DOS or Windows. To start at a 4587 specific point in time, provide datetime in the format 4588 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC. 4589 4590 By default the RTC is driven by the host system time. This allows 4591 using of the RTC as accurate reference clock inside the guest, 4592 specifically if the host time is smoothly following an accurate 4593 external reference clock, e.g. via NTP. If you want to isolate the 4594 guest time from the host, you can set ``clock`` to ``rt`` instead, 4595 which provides a host monotonic clock if host support it. To even 4596 prevent the RTC from progressing during suspension, you can set 4597 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is 4598 recommended especially in icount mode in order to preserve 4599 determinism; however, note that in icount mode the speed of the 4600 virtual clock is variable and can in general differ from the host 4601 clock. 4602 4603 Enable ``driftfix`` (i386 targets only) if you experience time drift 4604 problems, specifically with Windows' ACPI HAL. This option will try 4605 to figure out how many timer interrupts were not processed by the 4606 Windows guest and will re-inject them. 4607ERST 4608 4609DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 4610 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \ 4611 " enable virtual instruction counter with 2^N clock ticks per\n" \ 4612 " instruction, enable aligning the host and virtual clocks\n" \ 4613 " or disable real time cpu sleeping, and optionally enable\n" \ 4614 " record-and-replay mode\n", QEMU_ARCH_ALL) 4615SRST 4616``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]`` 4617 Enable virtual instruction counter. The virtual cpu will execute one 4618 instruction every 2^N ns of virtual time. If ``auto`` is specified 4619 then the virtual cpu speed will be automatically adjusted to keep 4620 virtual time within a few seconds of real time. 4621 4622 Note that while this option can give deterministic behavior, it does 4623 not provide cycle accurate emulation. Modern CPUs contain 4624 superscalar out of order cores with complex cache hierarchies. The 4625 number of instructions executed often has little or no correlation 4626 with actual performance. 4627 4628 When the virtual cpu is sleeping, the virtual time will advance at 4629 default speed unless ``sleep=on`` is specified. With 4630 ``sleep=on``, the virtual time will jump to the next timer 4631 deadline instantly whenever the virtual cpu goes to sleep mode and 4632 will not advance if no timer is enabled. This behavior gives 4633 deterministic execution times from the guest point of view. 4634 The default if icount is enabled is ``sleep=off``. 4635 ``sleep=on`` cannot be used together with either ``shift=auto`` 4636 or ``align=on``. 4637 4638 ``align=on`` will activate the delay algorithm which will try to 4639 synchronise the host clock and the virtual clock. The goal is to 4640 have a guest running at the real frequency imposed by the shift 4641 option. Whenever the guest clock is behind the host clock and if 4642 ``align=on`` is specified then we print a message to the user to 4643 inform about the delay. Currently this option does not work when 4644 ``shift`` is ``auto``. Note: The sync algorithm will work for those 4645 shift values for which the guest clock runs ahead of the host clock. 4646 Typically this happens when the shift value is high (how high 4647 depends on the host machine). The default if icount is enabled 4648 is ``align=off``. 4649 4650 When the ``rr`` option is specified deterministic record/replay is 4651 enabled. The ``rrfile=`` option must also be provided to 4652 specify the path to the replay log. In record mode data is written 4653 to this file, and in replay mode it is read back. 4654 If the ``rrsnapshot`` option is given then it specifies a VM snapshot 4655 name. In record mode, a new VM snapshot with the given name is created 4656 at the start of execution recording. In replay mode this option 4657 specifies the snapshot name used to load the initial VM state. 4658ERST 4659 4660DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 4661 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 4662 " action when watchdog fires [default=reset]\n", 4663 QEMU_ARCH_ALL) 4664SRST 4665``-watchdog-action action`` 4666 The action controls what QEMU will do when the watchdog timer 4667 expires. The default is ``reset`` (forcefully reset the guest). 4668 Other possible actions are: ``shutdown`` (attempt to gracefully 4669 shutdown the guest), ``poweroff`` (forcefully poweroff the guest), 4670 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the 4671 guest), ``debug`` (print a debug message and continue), or ``none`` 4672 (do nothing). 4673 4674 Note that the ``shutdown`` action requires that the guest responds 4675 to ACPI signals, which it may not be able to do in the sort of 4676 situations where the watchdog would have expired, and thus 4677 ``-watchdog-action shutdown`` is not recommended for production use. 4678 4679 Examples: 4680 4681 ``-device i6300esb -watchdog-action pause`` 4682 4683ERST 4684 4685DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 4686 "-echr chr set terminal escape character instead of ctrl-a\n", 4687 QEMU_ARCH_ALL) 4688SRST 4689``-echr numeric_ascii_value`` 4690 Change the escape character used for switching to the monitor when 4691 using monitor and serial sharing. The default is ``0x01`` when using 4692 the ``-nographic`` option. ``0x01`` is equal to pressing 4693 ``Control-a``. You can select a different character from the ascii 4694 control keys where 1 through 26 map to Control-a through Control-z. 4695 For instance you could use the either of the following to change the 4696 escape character to Control-t. 4697 4698 ``-echr 0x14``; \ ``-echr 20`` 4699 4700ERST 4701 4702DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4703 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \ 4704 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \ 4705 "-incoming unix:socketpath\n" \ 4706 " prepare for incoming migration, listen on\n" \ 4707 " specified protocol and socket address\n" \ 4708 "-incoming fd:fd\n" \ 4709 "-incoming file:filename[,offset=offset]\n" \ 4710 "-incoming exec:cmdline\n" \ 4711 " accept incoming migration on given file descriptor\n" \ 4712 " or from given external command\n" \ 4713 "-incoming defer\n" \ 4714 " wait for the URI to be specified via migrate_incoming\n", 4715 QEMU_ARCH_ALL) 4716SRST 4717``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]`` 4718 \ 4719``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]`` 4720 Prepare for incoming migration, listen on a given tcp port. 4721 4722``-incoming unix:socketpath`` 4723 Prepare for incoming migration, listen on a given unix socket. 4724 4725``-incoming fd:fd`` 4726 Accept incoming migration from a given file descriptor. 4727 4728``-incoming file:filename[,offset=offset]`` 4729 Accept incoming migration from a given file starting at offset. 4730 offset allows the common size suffixes, or a 0x prefix, but not both. 4731 4732``-incoming exec:cmdline`` 4733 Accept incoming migration as an output from specified external 4734 command. 4735 4736``-incoming defer`` 4737 Wait for the URI to be specified via migrate\_incoming. The monitor 4738 can be used to change settings (such as migration parameters) prior 4739 to issuing the migrate\_incoming to allow the migration to begin. 4740ERST 4741 4742DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4743 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4744SRST 4745``-only-migratable`` 4746 Only allow migratable devices. Devices will not be allowed to enter 4747 an unmigratable state. 4748ERST 4749 4750DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4751 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4752SRST 4753``-nodefaults`` 4754 Don't create default devices. Normally, QEMU sets the default 4755 devices like serial port, parallel port, virtual console, monitor 4756 device, VGA adapter, floppy and CD-ROM drive and others. The 4757 ``-nodefaults`` option will disable all those default devices. 4758ERST 4759 4760#ifndef _WIN32 4761DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4762 "-chroot dir chroot to dir just before starting the VM (deprecated)\n", 4763 QEMU_ARCH_ALL) 4764#endif 4765SRST 4766``-chroot dir`` 4767 Deprecated, use '-run-with chroot=...' instead. 4768 Immediately before starting guest execution, chroot to the specified 4769 directory. Especially useful in combination with -runas. 4770ERST 4771 4772#ifndef _WIN32 4773DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4774 "-runas user change to user id user just before starting the VM\n" \ 4775 " user can be numeric uid:gid instead\n", 4776 QEMU_ARCH_ALL) 4777#endif 4778SRST 4779``-runas user`` 4780 Immediately before starting guest execution, drop root privileges, 4781 switching to the specified user. 4782ERST 4783 4784DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4785 "-prom-env variable=value\n" 4786 " set OpenBIOS nvram variables\n", 4787 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4788SRST 4789``-prom-env variable=value`` 4790 Set OpenBIOS nvram variable to given value (PPC, SPARC only). 4791 4792 :: 4793 4794 qemu-system-sparc -prom-env 'auto-boot?=false' \ 4795 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' 4796 4797 :: 4798 4799 qemu-system-ppc -prom-env 'auto-boot?=false' \ 4800 -prom-env 'boot-device=hd:2,\yaboot' \ 4801 -prom-env 'boot-args=conf=hd:2,\yaboot.conf' 4802ERST 4803DEF("semihosting", 0, QEMU_OPTION_semihosting, 4804 "-semihosting semihosting mode\n", 4805 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4806 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4807SRST 4808``-semihosting`` 4809 Enable :ref:`Semihosting` mode (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V only). 4810 4811 .. warning:: 4812 Note that this allows guest direct access to the host filesystem, so 4813 should only be used with a trusted guest OS. 4814 4815 See the -semihosting-config option documentation for further 4816 information about the facilities this enables. 4817ERST 4818DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4819 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]\n" \ 4820 " semihosting configuration\n", 4821QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4822QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4823SRST 4824``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]`` 4825 Enable and configure :ref:`Semihosting` (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V 4826 only). 4827 4828 .. warning:: 4829 Note that this allows guest direct access to the host filesystem, so 4830 should only be used with a trusted guest OS. 4831 4832 ``target=native|gdb|auto`` 4833 Defines where the semihosting calls will be addressed, to QEMU 4834 (``native``) or to GDB (``gdb``). The default is ``auto``, which 4835 means ``gdb`` during debug sessions and ``native`` otherwise. 4836 4837 ``chardev=str1`` 4838 Send the output to a chardev backend output for native or auto 4839 output when not in gdb 4840 4841 ``userspace=on|off`` 4842 Allows code running in guest userspace to access the semihosting 4843 interface. The default is that only privileged guest code can 4844 make semihosting calls. Note that setting ``userspace=on`` should 4845 only be used if all guest code is trusted (for example, in 4846 bare-metal test case code). 4847 4848 ``arg=str1,arg=str2,...`` 4849 Allows the user to pass input arguments, and can be used 4850 multiple times to build up a list. The old-style 4851 ``-kernel``/``-append`` method of passing a command line is 4852 still supported for backward compatibility. If both the 4853 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are 4854 specified, the former is passed to semihosting as it always 4855 takes precedence. 4856ERST 4857DEF("old-param", 0, QEMU_OPTION_old_param, 4858 "-old-param old param mode\n", QEMU_ARCH_ARM) 4859SRST 4860``-old-param`` 4861 Old param mode (ARM only). 4862ERST 4863 4864DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4865 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4866 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4867 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4868 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4869 " by the kernel, but typically no longer used by modern\n" \ 4870 " C library implementations.\n" \ 4871 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \ 4872 " to elevate privileges using set*uid|gid system calls.\n" \ 4873 " The value 'children' will deny set*uid|gid system calls for\n" \ 4874 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4875 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4876 " blocking *fork and execve\n" \ 4877 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4878 QEMU_ARCH_ALL) 4879SRST 4880``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]`` 4881 Enable Seccomp mode 2 system call filter. 'on' will enable syscall 4882 filtering and 'off' will disable it. The default is 'off'. 4883 4884 ``obsolete=string`` 4885 Enable Obsolete system calls 4886 4887 ``elevateprivileges=string`` 4888 Disable set\*uid\|gid system calls 4889 4890 ``spawn=string`` 4891 Disable \*fork and execve 4892 4893 ``resourcecontrol=string`` 4894 Disable process affinity and schedular priority 4895ERST 4896 4897DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4898 "-readconfig <file>\n" 4899 " read config file\n", QEMU_ARCH_ALL) 4900SRST 4901``-readconfig file`` 4902 Read device configuration from file. This approach is useful when 4903 you want to spawn QEMU process with many command line options but 4904 you don't want to exceed the command line character limit. 4905ERST 4906 4907DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4908 "-no-user-config\n" 4909 " do not load default user-provided config files at startup\n", 4910 QEMU_ARCH_ALL) 4911SRST 4912``-no-user-config`` 4913 The ``-no-user-config`` option makes QEMU not load any of the 4914 user-provided config files on sysconfdir. 4915ERST 4916 4917DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4918 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4919 " specify tracing options\n", 4920 QEMU_ARCH_ALL) 4921SRST 4922``-trace [[enable=]pattern][,events=file][,file=file]`` 4923 .. include:: ../qemu-option-trace.rst.inc 4924 4925ERST 4926DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4927 "-plugin [file=]<file>[,<argname>=<argvalue>]\n" 4928 " load a plugin\n", 4929 QEMU_ARCH_ALL) 4930SRST 4931``-plugin file=file[,argname=argvalue]`` 4932 Load a plugin. 4933 4934 ``file=file`` 4935 Load the given plugin from a shared library file. 4936 4937 ``argname=argvalue`` 4938 Argument passed to the plugin. (Can be given multiple times.) 4939ERST 4940 4941HXCOMM Internal use 4942DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4943DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4944 4945#ifdef __linux__ 4946DEF("async-teardown", 0, QEMU_OPTION_asyncteardown, 4947 "-async-teardown enable asynchronous teardown\n", 4948 QEMU_ARCH_ALL) 4949SRST 4950``-async-teardown`` 4951 This option is deprecated and should no longer be used. The new option 4952 ``-run-with async-teardown=on`` is a replacement. 4953ERST 4954#endif 4955#ifdef CONFIG_POSIX 4956DEF("run-with", HAS_ARG, QEMU_OPTION_run_with, 4957 "-run-with [async-teardown=on|off][,chroot=dir]\n" 4958 " Set miscellaneous QEMU process lifecycle options:\n" 4959 " async-teardown=on enables asynchronous teardown (Linux only)\n" 4960 " chroot=dir chroot to dir just before starting the VM\n", 4961 QEMU_ARCH_ALL) 4962SRST 4963``-run-with [async-teardown=on|off][,chroot=dir]`` 4964 Set QEMU process lifecycle options. 4965 4966 ``async-teardown=on`` enables asynchronous teardown. A new process called 4967 "cleanup/<QEMU_PID>" will be created at startup sharing the address 4968 space with the main QEMU process, using clone. It will wait for the 4969 main QEMU process to terminate completely, and then exit. This allows 4970 QEMU to terminate very quickly even if the guest was huge, leaving the 4971 teardown of the address space to the cleanup process. Since the cleanup 4972 process shares the same cgroups as the main QEMU process, accounting is 4973 performed correctly. This only works if the cleanup process is not 4974 forcefully killed with SIGKILL before the main QEMU process has 4975 terminated completely. 4976 4977 ``chroot=dir`` can be used for doing a chroot to the specified directory 4978 immediately before starting the guest execution. This is especially useful 4979 in combination with -runas. 4980ERST 4981#endif 4982 4983DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4984 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n" 4985 " control error message format\n" 4986 " timestamp=on enables timestamps (default: off)\n" 4987 " guest-name=on enables guest name prefix but only if\n" 4988 " -name guest option is set (default: off)\n", 4989 QEMU_ARCH_ALL) 4990SRST 4991``-msg [timestamp[=on|off]][,guest-name[=on|off]]`` 4992 Control error message format. 4993 4994 ``timestamp=on|off`` 4995 Prefix messages with a timestamp. Default is off. 4996 4997 ``guest-name=on|off`` 4998 Prefix messages with guest name but only if -name guest option is set 4999 otherwise the option is ignored. Default is off. 5000ERST 5001 5002DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 5003 "-dump-vmstate <file>\n" 5004 " Output vmstate information in JSON format to file.\n" 5005 " Use the scripts/vmstate-static-checker.py file to\n" 5006 " check for possible regressions in migration code\n" 5007 " by comparing two such vmstate dumps.\n", 5008 QEMU_ARCH_ALL) 5009SRST 5010``-dump-vmstate file`` 5011 Dump json-encoded vmstate information for current machine type to 5012 file in file 5013ERST 5014 5015DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 5016 "-enable-sync-profile\n" 5017 " enable synchronization profiling\n", 5018 QEMU_ARCH_ALL) 5019SRST 5020``-enable-sync-profile`` 5021 Enable synchronization profiling. 5022ERST 5023 5024#if defined(CONFIG_TCG) && defined(CONFIG_LINUX) 5025DEF("perfmap", 0, QEMU_OPTION_perfmap, 5026 "-perfmap generate a /tmp/perf-${pid}.map file for perf\n", 5027 QEMU_ARCH_ALL) 5028SRST 5029``-perfmap`` 5030 Generate a map file for Linux perf tools that will allow basic profiling 5031 information to be broken down into basic blocks. 5032ERST 5033 5034DEF("jitdump", 0, QEMU_OPTION_jitdump, 5035 "-jitdump generate a jit-${pid}.dump file for perf\n", 5036 QEMU_ARCH_ALL) 5037SRST 5038``-jitdump`` 5039 Generate a dump file for Linux perf tools that maps basic blocks to symbol 5040 names, line numbers and JITted code. 5041ERST 5042#endif 5043 5044DEFHEADING() 5045 5046DEFHEADING(Generic object creation:) 5047 5048DEF("object", HAS_ARG, QEMU_OPTION_object, 5049 "-object TYPENAME[,PROP1=VALUE1,...]\n" 5050 " create a new object of type TYPENAME setting properties\n" 5051 " in the order they are specified. Note that the 'id'\n" 5052 " property must be set. These objects are placed in the\n" 5053 " '/objects' path.\n", 5054 QEMU_ARCH_ALL) 5055SRST 5056``-object typename[,prop1=value1,...]`` 5057 Create a new object of type typename setting properties in the order 5058 they are specified. Note that the 'id' property must be set. These 5059 objects are placed in the '/objects' path. 5060 5061 ``-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,offset=offset,readonly=on|off,rom=on|off|auto`` 5062 Creates a memory file backend object, which can be used to back 5063 the guest RAM with huge pages. 5064 5065 The ``id`` parameter is a unique ID that will be used to 5066 reference this memory region in other parameters, e.g. ``-numa``, 5067 ``-device nvdimm``, etc. 5068 5069 The ``size`` option provides the size of the memory region, and 5070 accepts common suffixes, e.g. ``500M``. 5071 5072 The ``mem-path`` provides the path to either a shared memory or 5073 huge page filesystem mount. 5074 5075 The ``share`` boolean option determines whether the memory 5076 region is marked as private to QEMU, or shared. The latter 5077 allows a co-operating external process to access the QEMU memory 5078 region. 5079 5080 The ``share`` is also required for pvrdma devices due to 5081 limitations in the RDMA API provided by Linux. 5082 5083 Setting share=on might affect the ability to configure NUMA 5084 bindings for the memory backend under some circumstances, see 5085 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel 5086 source tree for additional details. 5087 5088 Setting the ``discard-data`` boolean option to on indicates that 5089 file contents can be destroyed when QEMU exits, to avoid 5090 unnecessarily flushing data to the backing file. Note that 5091 ``discard-data`` is only an optimization, and QEMU might not 5092 discard file contents if it aborts unexpectedly or is terminated 5093 using SIGKILL. 5094 5095 The ``merge`` boolean option enables memory merge, also known as 5096 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider 5097 the pages for memory deduplication. 5098 5099 Setting the ``dump`` boolean option to off excludes the memory 5100 from core dumps. This feature is also known as MADV\_DONTDUMP. 5101 5102 The ``prealloc`` boolean option enables memory preallocation. 5103 5104 The ``host-nodes`` option binds the memory range to a list of 5105 NUMA host nodes. 5106 5107 The ``policy`` option sets the NUMA policy to one of the 5108 following values: 5109 5110 ``default`` 5111 default host policy 5112 5113 ``preferred`` 5114 prefer the given host node list for allocation 5115 5116 ``bind`` 5117 restrict memory allocation to the given host node list 5118 5119 ``interleave`` 5120 interleave memory allocations across the given host node 5121 list 5122 5123 The ``align`` option specifies the base address alignment when 5124 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg 5125 ``2M``. Some backend store specified by ``mem-path`` requires an 5126 alignment different than the default one used by QEMU, eg the 5127 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 5128 such cases, users can specify the required alignment via this 5129 option. 5130 5131 The ``offset`` option specifies the offset into the target file 5132 that the region starts at. You can use this parameter to back 5133 multiple regions with a single file. 5134 5135 The ``pmem`` option specifies whether the backing file specified 5136 by ``mem-path`` is in host persistent memory that can be 5137 accessed using the SNIA NVM programming model (e.g. Intel 5138 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary 5139 operations to guarantee the persistence of its own writes to 5140 ``mem-path`` (e.g. in vNVDIMM label emulation and live 5141 migration). Also, we will map the backend-file with MAP\_SYNC 5142 flag, which ensures the file metadata is in sync for 5143 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC 5144 requires support from both the host kernel (since Linux kernel 5145 4.15) and the filesystem of ``mem-path`` mounted with DAX 5146 option. 5147 5148 The ``readonly`` option specifies whether the backing file is opened 5149 read-only or read-write (default). 5150 5151 The ``rom`` option specifies whether to create Read Only Memory 5152 (ROM) that cannot be modified by the VM. Any write attempts to such 5153 ROM will be denied. Most use cases want proper RAM instead of ROM. 5154 However, selected use cases, like R/O NVDIMMs, can benefit from 5155 ROM. If set to ``on``, create ROM; if set to ``off``, create 5156 writable RAM; if set to ``auto`` (default), the value of the 5157 ``readonly`` option is used. This option is primarily helpful when 5158 we want to have writable RAM in configurations that would 5159 traditionally create ROM before the ``rom`` option was introduced: 5160 VM templating, where we want to open a file readonly 5161 (``readonly=on``) and mark the memory to be private for QEMU 5162 (``share=off``). For this use case, we need writable RAM instead 5163 of ROM, and want to also set ``rom=off``. 5164 5165 ``-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`` 5166 Creates a memory backend object, which can be used to back the 5167 guest RAM. Memory backend objects offer more control than the 5168 ``-m`` option that is traditionally used to define guest RAM. 5169 Please refer to ``memory-backend-file`` for a description of the 5170 options. 5171 5172 ``-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`` 5173 Creates an anonymous memory file backend object, which allows 5174 QEMU to share the memory with an external process (e.g. when 5175 using vhost-user). The memory is allocated with memfd and 5176 optional sealing. (Linux only) 5177 5178 The ``seal`` option creates a sealed-file, that will block 5179 further resizing the memory ('on' by default). 5180 5181 The ``hugetlb`` option specify the file to be created resides in 5182 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction 5183 with the ``hugetlb`` option, the ``hugetlbsize`` option specify 5184 the hugetlb page size on systems that support multiple hugetlb 5185 page sizes (it must be a power of 2 value supported by the 5186 system). 5187 5188 In some versions of Linux, the ``hugetlb`` option is 5189 incompatible with the ``seal`` option (requires at least Linux 5190 4.16). 5191 5192 Please refer to ``memory-backend-file`` for a description of the 5193 other options. 5194 5195 The ``share`` boolean option is on by default with memfd. 5196 5197 ``-object rng-builtin,id=id`` 5198 Creates a random number generator backend which obtains entropy 5199 from QEMU builtin functions. The ``id`` parameter is a unique ID 5200 that will be used to reference this entropy backend from the 5201 ``virtio-rng`` device. By default, the ``virtio-rng`` device 5202 uses this RNG backend. 5203 5204 ``-object rng-random,id=id,filename=/dev/random`` 5205 Creates a random number generator backend which obtains entropy 5206 from a device on the host. The ``id`` parameter is a unique ID 5207 that will be used to reference this entropy backend from the 5208 ``virtio-rng`` device. The ``filename`` parameter specifies 5209 which file to obtain entropy from and if omitted defaults to 5210 ``/dev/urandom``. 5211 5212 ``-object rng-egd,id=id,chardev=chardevid`` 5213 Creates a random number generator backend which obtains entropy 5214 from an external daemon running on the host. The ``id`` 5215 parameter is a unique ID that will be used to reference this 5216 entropy backend from the ``virtio-rng`` device. The ``chardev`` 5217 parameter is the unique ID of a character device backend that 5218 provides the connection to the RNG daemon. 5219 5220 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off`` 5221 Creates a TLS anonymous credentials object, which can be used to 5222 provide TLS support on network backends. The ``id`` parameter is 5223 a unique ID which network backends will use to access the 5224 credentials. The ``endpoint`` is either ``server`` or ``client`` 5225 depending on whether the QEMU network backend that uses the 5226 credentials will be acting as a client or as a server. If 5227 ``verify-peer`` is enabled (the default) then once the handshake 5228 is completed, the peer credentials will be verified, though this 5229 is a no-op for anonymous credentials. 5230 5231 The dir parameter tells QEMU where to find the credential files. 5232 For server endpoints, this directory may contain a file 5233 dh-params.pem providing diffie-hellman parameters to use for the 5234 TLS server. If the file is missing, QEMU will generate a set of 5235 DH parameters at startup. This is a computationally expensive 5236 operation that consumes random pool entropy, so it is 5237 recommended that a persistent set of parameters be generated 5238 upfront and saved. 5239 5240 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]`` 5241 Creates a TLS Pre-Shared Keys (PSK) credentials object, which 5242 can be used to provide TLS support on network backends. The 5243 ``id`` parameter is a unique ID which network backends will use 5244 to access the credentials. The ``endpoint`` is either ``server`` 5245 or ``client`` depending on whether the QEMU network backend that 5246 uses the credentials will be acting as a client or as a server. 5247 For clients only, ``username`` is the username which will be 5248 sent to the server. If omitted it defaults to "qemu". 5249 5250 The dir parameter tells QEMU where to find the keys file. It is 5251 called "dir/keys.psk" and contains "username:key" pairs. This 5252 file can most easily be created using the GnuTLS ``psktool`` 5253 program. 5254 5255 For server endpoints, dir may also contain a file dh-params.pem 5256 providing diffie-hellman parameters to use for the TLS server. 5257 If the file is missing, QEMU will generate a set of DH 5258 parameters at startup. This is a computationally expensive 5259 operation that consumes random pool entropy, so it is 5260 recommended that a persistent set of parameters be generated up 5261 front and saved. 5262 5263 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id`` 5264 Creates a TLS anonymous credentials object, which can be used to 5265 provide TLS support on network backends. The ``id`` parameter is 5266 a unique ID which network backends will use to access the 5267 credentials. The ``endpoint`` is either ``server`` or ``client`` 5268 depending on whether the QEMU network backend that uses the 5269 credentials will be acting as a client or as a server. If 5270 ``verify-peer`` is enabled (the default) then once the handshake 5271 is completed, the peer credentials will be verified. With x509 5272 certificates, this implies that the clients must be provided 5273 with valid client certificates too. 5274 5275 The dir parameter tells QEMU where to find the credential files. 5276 For server endpoints, this directory may contain a file 5277 dh-params.pem providing diffie-hellman parameters to use for the 5278 TLS server. If the file is missing, QEMU will generate a set of 5279 DH parameters at startup. This is a computationally expensive 5280 operation that consumes random pool entropy, so it is 5281 recommended that a persistent set of parameters be generated 5282 upfront and saved. 5283 5284 For x509 certificate credentials the directory will contain 5285 further files providing the x509 certificates. The certificates 5286 must be stored in PEM format, in filenames ca-cert.pem, 5287 ca-crl.pem (optional), server-cert.pem (only servers), 5288 server-key.pem (only servers), client-cert.pem (only clients), 5289 and client-key.pem (only clients). 5290 5291 For the server-key.pem and client-key.pem files which contain 5292 sensitive private keys, it is possible to use an encrypted 5293 version by providing the passwordid parameter. This provides the 5294 ID of a previously created ``secret`` object containing the 5295 password for decryption. 5296 5297 The priority parameter allows to override the global default 5298 priority used by gnutls. This can be useful if the system 5299 administrator needs to use a weaker set of crypto priorities for 5300 QEMU without potentially forcing the weakness onto all 5301 applications. Or conversely if one wants wants a stronger 5302 default for QEMU than for all other applications, they can do 5303 this through this parameter. Its format is a gnutls priority 5304 string as described at 5305 https://gnutls.org/manual/html_node/Priority-Strings.html. 5306 5307 ``-object tls-cipher-suites,id=id,priority=priority`` 5308 Creates a TLS cipher suites object, which can be used to control 5309 the TLS cipher/protocol algorithms that applications are permitted 5310 to use. 5311 5312 The ``id`` parameter is a unique ID which frontends will use to 5313 access the ordered list of permitted TLS cipher suites from the 5314 host. 5315 5316 The ``priority`` parameter allows to override the global default 5317 priority used by gnutls. This can be useful if the system 5318 administrator needs to use a weaker set of crypto priorities for 5319 QEMU without potentially forcing the weakness onto all 5320 applications. Or conversely if one wants wants a stronger 5321 default for QEMU than for all other applications, they can do 5322 this through this parameter. Its format is a gnutls priority 5323 string as described at 5324 https://gnutls.org/manual/html_node/Priority-Strings.html. 5325 5326 An example of use of this object is to control UEFI HTTPS Boot. 5327 The tls-cipher-suites object exposes the ordered list of permitted 5328 TLS cipher suites from the host side to the guest firmware, via 5329 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER 5330 objects. The firmware uses the IANA_TLS_CIPHER array for configuring 5331 guest-side TLS. 5332 5333 In the following example, the priority at which the host-side policy 5334 is retrieved is given by the ``priority`` property. 5335 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to 5336 refer to /etc/crypto-policies/back-ends/gnutls.config. 5337 5338 .. parsed-literal:: 5339 5340 # |qemu_system| \\ 5341 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\ 5342 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 5343 5344 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` 5345 Interval t can't be 0, this filter batches the packet delivery: 5346 all packets arriving in a given interval on netdev netdevid are 5347 delayed until the end of the interval. Interval is in 5348 microseconds. ``status`` is optional that indicate whether the 5349 netfilter is on (enabled) or off (disabled), the default status 5350 for netfilter will be 'on'. 5351 5352 queue all\|rx\|tx is an option that can be applied to any 5353 netfilter. 5354 5355 ``all``: the filter is attached both to the receive and the 5356 transmit queue of the netdev (default). 5357 5358 ``rx``: the filter is attached to the receive queue of the 5359 netdev, where it will receive packets sent to the netdev. 5360 5361 ``tx``: the filter is attached to the transmit queue of the 5362 netdev, where it will receive packets sent by the netdev. 5363 5364 position head\|tail\|id=<id> is an option to specify where the 5365 filter should be inserted in the filter list. It can be applied 5366 to any netfilter. 5367 5368 ``head``: the filter is inserted at the head of the filter list, 5369 before any existing filters. 5370 5371 ``tail``: the filter is inserted at the tail of the filter list, 5372 behind any existing filters (default). 5373 5374 ``id=<id>``: the filter is inserted before or behind the filter 5375 specified by <id>, see the insert option below. 5376 5377 insert behind\|before is an option to specify where to insert 5378 the new filter relative to the one specified with 5379 position=id=<id>. It can be applied to any netfilter. 5380 5381 ``before``: insert before the specified filter. 5382 5383 ``behind``: insert behind the specified filter (default). 5384 5385 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5386 filter-mirror on netdev netdevid,mirror net packet to 5387 chardevchardevid, if it has the vnet\_hdr\_support flag, 5388 filter-mirror will mirror packet with vnet\_hdr\_len. 5389 5390 ``-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]`` 5391 filter-redirector on netdev netdevid,redirect filter's net 5392 packet to chardev chardevid,and redirect indev's packet to 5393 filter.if it has the vnet\_hdr\_support flag, filter-redirector 5394 will redirect packet with vnet\_hdr\_len. Create a 5395 filter-redirector we need to differ outdev id from indev id, id 5396 can not be the same. we can just use indev or outdev, but at 5397 least one of indev or outdev need to be specified. 5398 5399 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5400 Filter-rewriter is a part of COLO project.It will rewrite tcp 5401 packet to secondary from primary to keep secondary tcp 5402 connection,and rewrite tcp packet to primary from secondary make 5403 tcp packet can be handled by client.if it has the 5404 vnet\_hdr\_support flag, we can parse packet with vnet header. 5405 5406 usage: colo secondary: -object 5407 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object 5408 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object 5409 filter-rewriter,id=rew0,netdev=hn0,queue=all 5410 5411 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]`` 5412 Dump the network traffic on netdev dev to the file specified by 5413 filename. At most len bytes (64k by default) per packet are 5414 stored. The file format is libpcap, so it can be analyzed with 5415 tools such as tcpdump or Wireshark. 5416 5417 ``-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}]`` 5418 Colo-compare gets packet from primary\_in chardevid and 5419 secondary\_in, then compare whether the payload of primary packet 5420 and secondary packet are the same. If same, it will output 5421 primary packet to out\_dev, else it will notify COLO-framework to do 5422 checkpoint and send primary packet to out\_dev. In order to 5423 improve efficiency, we need to put the task of comparison in 5424 another iothread. If it has the vnet\_hdr\_support flag, 5425 colo compare will send/recv packet with vnet\_hdr\_len. 5426 The compare\_timeout=@var{ms} determines the maximum time of the 5427 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms} 5428 is to set the period of scanning expired primary node network packets. 5429 The max\_queue\_size=@var{size} is to set the max compare queue 5430 size depend on user environment. 5431 If user want to use Xen COLO, need to add the notify\_dev to 5432 notify Xen colo-frame to do checkpoint. 5433 5434 COLO-compare must be used with the help of filter-mirror, 5435 filter-redirector and filter-rewriter. 5436 5437 :: 5438 5439 KVM COLO 5440 5441 primary: 5442 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5443 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5444 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5445 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5446 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5447 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5448 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5449 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5450 -object iothread,id=iothread1 5451 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5452 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5453 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5454 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 5455 5456 secondary: 5457 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5458 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5459 -chardev socket,id=red0,host=3.3.3.3,port=9003 5460 -chardev socket,id=red1,host=3.3.3.3,port=9004 5461 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5462 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5463 5464 5465 Xen COLO 5466 5467 primary: 5468 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5469 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5470 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5471 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5472 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5473 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5474 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5475 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5476 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off 5477 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5478 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5479 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5480 -object iothread,id=iothread1 5481 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 5482 5483 secondary: 5484 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5485 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5486 -chardev socket,id=red0,host=3.3.3.3,port=9003 5487 -chardev socket,id=red1,host=3.3.3.3,port=9004 5488 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5489 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5490 5491 If you want to know the detail of above command line, you can 5492 read the colo-compare git log. 5493 5494 ``-object cryptodev-backend-builtin,id=id[,queues=queues]`` 5495 Creates a cryptodev backend which executes crypto operations from 5496 the QEMU cipher APIs. The id parameter is a unique ID that will 5497 be used to reference this cryptodev backend from the 5498 ``virtio-crypto`` device. The queues parameter is optional, 5499 which specify the queue number of cryptodev backend, the default 5500 of queues is 1. 5501 5502 .. parsed-literal:: 5503 5504 # |qemu_system| \\ 5505 [...] \\ 5506 -object cryptodev-backend-builtin,id=cryptodev0 \\ 5507 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5508 [...] 5509 5510 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]`` 5511 Creates a vhost-user cryptodev backend, backed by a chardev 5512 chardevid. The id parameter is a unique ID that will be used to 5513 reference this cryptodev backend from the ``virtio-crypto`` 5514 device. The chardev should be a unix domain socket backed one. 5515 The vhost-user uses a specifically defined protocol to pass 5516 vhost ioctl replacement messages to an application on the other 5517 end of the socket. The queues parameter is optional, which 5518 specify the queue number of cryptodev backend for multiqueue 5519 vhost-user, the default of queues is 1. 5520 5521 .. parsed-literal:: 5522 5523 # |qemu_system| \\ 5524 [...] \\ 5525 -chardev socket,id=chardev0,path=/path/to/socket \\ 5526 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\ 5527 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5528 [...] 5529 5530 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]`` 5531 \ 5532 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]`` 5533 Defines a secret to store a password, encryption key, or some 5534 other sensitive data. The sensitive data can either be passed 5535 directly via the data parameter, or indirectly via the file 5536 parameter. Using the data parameter is insecure unless the 5537 sensitive data is encrypted. 5538 5539 The sensitive data can be provided in raw format (the default), 5540 or base64. When encoded as JSON, the raw format only supports 5541 valid UTF-8 characters, so base64 is recommended for sending 5542 binary data. QEMU will convert from which ever format is 5543 provided to the format it needs internally. eg, an RBD password 5544 can be provided in raw format, even though it will be base64 5545 encoded when passed onto the RBD sever. 5546 5547 For added protection, it is possible to encrypt the data 5548 associated with a secret using the AES-256-CBC cipher. Use of 5549 encryption is indicated by providing the keyid and iv 5550 parameters. The keyid parameter provides the ID of a previously 5551 defined secret that contains the AES-256 decryption key. This 5552 key should be 32-bytes long and be base64 encoded. The iv 5553 parameter provides the random initialization vector used for 5554 encryption of this particular secret and should be a base64 5555 encrypted string of the 16-byte IV. 5556 5557 The simplest (insecure) usage is to provide the secret inline 5558 5559 .. parsed-literal:: 5560 5561 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw 5562 5563 The simplest secure usage is to provide the secret via a file 5564 5565 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object 5566 secret,id=sec0,file=mypasswd.txt,format=raw 5567 5568 For greater security, AES-256-CBC should be used. To illustrate 5569 usage, consider the openssl command line tool which can encrypt 5570 the data. Note that when encrypting, the plaintext must be 5571 padded to the cipher block size (32 bytes) using the standard 5572 PKCS#5/6 compatible padding algorithm. 5573 5574 First a master key needs to be created in base64 encoding: 5575 5576 :: 5577 5578 # openssl rand -base64 32 > key.b64 5579 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 5580 5581 Each secret to be encrypted needs to have a random 5582 initialization vector generated. These do not need to be kept 5583 secret 5584 5585 :: 5586 5587 # openssl rand -base64 16 > iv.b64 5588 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 5589 5590 The secret to be defined can now be encrypted, in this case 5591 we're telling openssl to base64 encode the result, but it could 5592 be left as raw bytes if desired. 5593 5594 :: 5595 5596 # SECRET=$(printf "letmein" | 5597 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 5598 5599 When launching QEMU, create a master secret pointing to 5600 ``key.b64`` and specify that to be used to decrypt the user 5601 password. Pass the contents of ``iv.b64`` to the second secret 5602 5603 .. parsed-literal:: 5604 5605 # |qemu_system| \\ 5606 -object secret,id=secmaster0,format=base64,file=key.b64 \\ 5607 -object secret,id=sec0,keyid=secmaster0,format=base64,\\ 5608 data=$SECRET,iv=$(<iv.b64) 5609 5610 ``-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]`` 5611 Create a Secure Encrypted Virtualization (SEV) guest object, 5612 which can be used to provide the guest memory encryption support 5613 on AMD processors. 5614 5615 When memory encryption is enabled, one of the physical address 5616 bit (aka the C-bit) is utilized to mark if a memory page is 5617 protected. The ``cbitpos`` is used to provide the C-bit 5618 position. The C-bit position is Host family dependent hence user 5619 must provide this value. On EPYC, the value should be 47. 5620 5621 When memory encryption is enabled, we loose certain bits in 5622 physical address space. The ``reduced-phys-bits`` is used to 5623 provide the number of bits we loose in physical address space. 5624 Similar to C-bit, the value is Host family dependent. On EPYC, 5625 a guest will lose a maximum of 1 bit, so the value should be 1. 5626 5627 The ``sev-device`` provides the device file to use for 5628 communicating with the SEV firmware running inside AMD Secure 5629 Processor. The default device is '/dev/sev'. If hardware 5630 supports memory encryption then /dev/sev devices are created by 5631 CCP driver. 5632 5633 The ``policy`` provides the guest policy to be enforced by the 5634 SEV firmware and restrict what configuration and operational 5635 commands can be performed on this guest by the hypervisor. The 5636 policy should be provided by the guest owner and is bound to the 5637 guest and cannot be changed throughout the lifetime of the 5638 guest. The default is 0. 5639 5640 If guest ``policy`` allows sharing the key with another SEV 5641 guest then ``handle`` can be use to provide handle of the guest 5642 from which to share the key. 5643 5644 The ``dh-cert-file`` and ``session-file`` provides the guest 5645 owner's Public Diffie-Hillman key defined in SEV spec. The PDH 5646 and session parameters are used for establishing a cryptographic 5647 session with the guest owner to negotiate keys used for 5648 attestation. The file must be encoded in base64. 5649 5650 The ``kernel-hashes`` adds the hashes of given kernel/initrd/ 5651 cmdline to a designated guest firmware page for measured Linux 5652 boot with -kernel. The default is off. (Since 6.2) 5653 5654 e.g to launch a SEV guest 5655 5656 .. parsed-literal:: 5657 5658 # |qemu_system_x86| \\ 5659 ...... \\ 5660 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \\ 5661 -machine ...,memory-encryption=sev0 \\ 5662 ..... 5663 5664 ``-object authz-simple,id=id,identity=string`` 5665 Create an authorization object that will control access to 5666 network services. 5667 5668 The ``identity`` parameter is identifies the user and its format 5669 depends on the network service that authorization object is 5670 associated with. For authorizing based on TLS x509 certificates, 5671 the identity must be the x509 distinguished name. Note that care 5672 must be taken to escape any commas in the distinguished name. 5673 5674 An example authorization object to validate a x509 distinguished 5675 name would look like: 5676 5677 .. parsed-literal:: 5678 5679 # |qemu_system| \\ 5680 ... \\ 5681 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\ 5682 ... 5683 5684 Note the use of quotes due to the x509 distinguished name 5685 containing whitespace, and escaping of ','. 5686 5687 ``-object authz-listfile,id=id,filename=path,refresh=on|off`` 5688 Create an authorization object that will control access to 5689 network services. 5690 5691 The ``filename`` parameter is the fully qualified path to a file 5692 containing the access control list rules in JSON format. 5693 5694 An example set of rules that match against SASL usernames might 5695 look like: 5696 5697 :: 5698 5699 { 5700 "rules": [ 5701 { "match": "fred", "policy": "allow", "format": "exact" }, 5702 { "match": "bob", "policy": "allow", "format": "exact" }, 5703 { "match": "danb", "policy": "deny", "format": "glob" }, 5704 { "match": "dan*", "policy": "allow", "format": "exact" }, 5705 ], 5706 "policy": "deny" 5707 } 5708 5709 When checking access the object will iterate over all the rules 5710 and the first rule to match will have its ``policy`` value 5711 returned as the result. If no rules match, then the default 5712 ``policy`` value is returned. 5713 5714 The rules can either be an exact string match, or they can use 5715 the simple UNIX glob pattern matching to allow wildcards to be 5716 used. 5717 5718 If ``refresh`` is set to true the file will be monitored and 5719 automatically reloaded whenever its content changes. 5720 5721 As with the ``authz-simple`` object, the format of the identity 5722 strings being matched depends on the network service, but is 5723 usually a TLS x509 distinguished name, or a SASL username. 5724 5725 An example authorization object to validate a SASL username 5726 would look like: 5727 5728 .. parsed-literal:: 5729 5730 # |qemu_system| \\ 5731 ... \\ 5732 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\ 5733 ... 5734 5735 ``-object authz-pam,id=id,service=string`` 5736 Create an authorization object that will control access to 5737 network services. 5738 5739 The ``service`` parameter provides the name of a PAM service to 5740 use for authorization. It requires that a file 5741 ``/etc/pam.d/service`` exist to provide the configuration for 5742 the ``account`` subsystem. 5743 5744 An example authorization object to validate a TLS x509 5745 distinguished name would look like: 5746 5747 .. parsed-literal:: 5748 5749 # |qemu_system| \\ 5750 ... \\ 5751 -object authz-pam,id=auth0,service=qemu-vnc \\ 5752 ... 5753 5754 There would then be a corresponding config file for PAM at 5755 ``/etc/pam.d/qemu-vnc`` that contains: 5756 5757 :: 5758 5759 account requisite pam_listfile.so item=user sense=allow \ 5760 file=/etc/qemu/vnc.allow 5761 5762 Finally the ``/etc/qemu/vnc.allow`` file would contain the list 5763 of x509 distinguished names that are permitted access 5764 5765 :: 5766 5767 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 5768 5769 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch`` 5770 Creates a dedicated event loop thread that devices can be 5771 assigned to. This is known as an IOThread. By default device 5772 emulation happens in vCPU threads or the main event loop thread. 5773 This can become a scalability bottleneck. IOThreads allow device 5774 emulation and I/O to run on other host CPUs. 5775 5776 The ``id`` parameter is a unique ID that will be used to 5777 reference this IOThread from ``-device ...,iothread=id``. 5778 Multiple devices can be assigned to an IOThread. Note that not 5779 all devices support an ``iothread`` parameter. 5780 5781 The ``query-iothreads`` QMP command lists IOThreads and reports 5782 their thread IDs so that the user can configure host CPU 5783 pinning/affinity. 5784 5785 IOThreads use an adaptive polling algorithm to reduce event loop 5786 latency. Instead of entering a blocking system call to monitor 5787 file descriptors and then pay the cost of being woken up when an 5788 event occurs, the polling algorithm spins waiting for events for 5789 a short time. The algorithm's default parameters are suitable 5790 for many cases but can be adjusted based on knowledge of the 5791 workload and/or host device latency. 5792 5793 The ``poll-max-ns`` parameter is the maximum number of 5794 nanoseconds to busy wait for events. Polling can be disabled by 5795 setting this value to 0. 5796 5797 The ``poll-grow`` parameter is the multiplier used to increase 5798 the polling time when the algorithm detects it is missing events 5799 due to not polling long enough. 5800 5801 The ``poll-shrink`` parameter is the divisor used to decrease 5802 the polling time when the algorithm detects it is spending too 5803 long polling without encountering events. 5804 5805 The ``aio-max-batch`` parameter is the maximum number of requests 5806 in a batch for the AIO engine, 0 means that the engine will use 5807 its default. 5808 5809 The IOThread parameters can be modified at run-time using the 5810 ``qom-set`` command (where ``iothread1`` is the IOThread's 5811 ``id``): 5812 5813 :: 5814 5815 (qemu) qom-set /objects/iothread1 poll-max-ns 100000 5816ERST 5817 5818 5819HXCOMM This is the last statement. Insert new options before this line! 5820 5821#undef DEF 5822#undef DEFHEADING 5823#undef ARCHHEADING 5824
