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 730HXCOMM Deprecated by -audiodev 731DEF("audio-help", 0, QEMU_OPTION_audio_help, 732 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 733 QEMU_ARCH_ALL) 734SRST 735``-audio-help`` 736 Will show the -audiodev equivalent of the currently specified 737 (deprecated) environment variables. 738ERST 739 740DEF("audio", HAS_ARG, QEMU_OPTION_audio, 741 "-audio [driver=]driver,model=value[,prop[=value][,...]]\n" 742 " specifies the audio backend and device to use;\n" 743 " apart from 'model', options are the same as for -audiodev.\n" 744 " use '-audio model=help' to show possible devices.\n", 745 QEMU_ARCH_ALL) 746SRST 747``-audio [driver=]driver,model=value[,prop[=value][,...]]`` 748 This option is a shortcut for configuring both the guest audio 749 hardware and the host audio backend in one go. 750 The driver option is the same as with the corresponding ``-audiodev`` option below. 751 The guest hardware model can be set with ``model=modelname``. 752 753 Use ``driver=help`` to list the available drivers, 754 and ``model=help`` to list the available device types. 755 756 The following two example do exactly the same, to show how ``-audio`` 757 can be used to shorten the command line length: 758 759 .. parsed-literal:: 760 761 |qemu_system| -audiodev pa,id=pa -device sb16,audiodev=pa 762 |qemu_system| -audio pa,model=sb16 763ERST 764 765DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 766 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 767 " specifies the audio backend to use\n" 768 " Use ``-audiodev help`` to list the available drivers\n" 769 " id= identifier of the backend\n" 770 " timer-period= timer period in microseconds\n" 771 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 772 " in|out.fixed-settings= use fixed settings for host audio\n" 773 " in|out.frequency= frequency to use with fixed settings\n" 774 " in|out.channels= number of channels to use with fixed settings\n" 775 " in|out.format= sample format to use with fixed settings\n" 776 " valid values: s8, s16, s32, u8, u16, u32, f32\n" 777 " in|out.voices= number of voices to use\n" 778 " in|out.buffer-length= length of buffer in microseconds\n" 779 "-audiodev none,id=id,[,prop[=value][,...]]\n" 780 " dummy driver that discards all output\n" 781#ifdef CONFIG_AUDIO_ALSA 782 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 783 " in|out.dev= name of the audio device to use\n" 784 " in|out.period-length= length of period in microseconds\n" 785 " in|out.try-poll= attempt to use poll mode\n" 786 " threshold= threshold (in microseconds) when playback starts\n" 787#endif 788#ifdef CONFIG_AUDIO_COREAUDIO 789 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 790 " in|out.buffer-count= number of buffers\n" 791#endif 792#ifdef CONFIG_AUDIO_DSOUND 793 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 794 " latency= add extra latency to playback in microseconds\n" 795#endif 796#ifdef CONFIG_AUDIO_OSS 797 "-audiodev oss,id=id[,prop[=value][,...]]\n" 798 " in|out.dev= path of the audio device to use\n" 799 " in|out.buffer-count= number of buffers\n" 800 " in|out.try-poll= attempt to use poll mode\n" 801 " try-mmap= try using memory mapped access\n" 802 " exclusive= open device in exclusive mode\n" 803 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 804#endif 805#ifdef CONFIG_AUDIO_PA 806 "-audiodev pa,id=id[,prop[=value][,...]]\n" 807 " server= PulseAudio server address\n" 808 " in|out.name= source/sink device name\n" 809 " in|out.latency= desired latency in microseconds\n" 810#endif 811#ifdef CONFIG_AUDIO_PIPEWIRE 812 "-audiodev pipewire,id=id[,prop[=value][,...]]\n" 813 " in|out.name= source/sink device name\n" 814 " in|out.stream-name= name of pipewire stream\n" 815 " in|out.latency= desired latency in microseconds\n" 816#endif 817#ifdef CONFIG_AUDIO_SDL 818 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 819 " in|out.buffer-count= number of buffers\n" 820#endif 821#ifdef CONFIG_AUDIO_SNDIO 822 "-audiodev sndio,id=id[,prop[=value][,...]]\n" 823#endif 824#ifdef CONFIG_SPICE 825 "-audiodev spice,id=id[,prop[=value][,...]]\n" 826#endif 827#ifdef CONFIG_DBUS_DISPLAY 828 "-audiodev dbus,id=id[,prop[=value][,...]]\n" 829#endif 830 "-audiodev wav,id=id[,prop[=value][,...]]\n" 831 " path= path of wav file to record\n", 832 QEMU_ARCH_ALL) 833SRST 834``-audiodev [driver=]driver,id=id[,prop[=value][,...]]`` 835 Adds a new audio backend driver identified by id. There are global 836 and driver specific properties. Some values can be set differently 837 for input and output, they're marked with ``in|out.``. You can set 838 the input's property with ``in.prop`` and the output's property with 839 ``out.prop``. For example: 840 841 :: 842 843 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 844 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 845 846 NOTE: parameter validation is known to be incomplete, in many cases 847 specifying an invalid option causes QEMU to print an error message 848 and continue emulation without sound. 849 850 Valid global options are: 851 852 ``id=identifier`` 853 Identifies the audio backend. 854 855 ``timer-period=period`` 856 Sets the timer period used by the audio subsystem in 857 microseconds. Default is 10000 (10 ms). 858 859 ``in|out.mixing-engine=on|off`` 860 Use QEMU's mixing engine to mix all streams inside QEMU and 861 convert audio formats when not supported by the backend. When 862 off, fixed-settings must be off too. Note that disabling this 863 option means that the selected backend must support multiple 864 streams and the audio formats used by the virtual cards, 865 otherwise you'll get no sound. It's not recommended to disable 866 this option unless you want to use 5.1 or 7.1 audio, as mixing 867 engine only supports mono and stereo audio. Default is on. 868 869 ``in|out.fixed-settings=on|off`` 870 Use fixed settings for host audio. When off, it will change 871 based on how the guest opens the sound card. In this case you 872 must not specify frequency, channels or format. Default is on. 873 874 ``in|out.frequency=frequency`` 875 Specify the frequency to use when using fixed-settings. Default 876 is 44100Hz. 877 878 ``in|out.channels=channels`` 879 Specify the number of channels to use when using fixed-settings. 880 Default is 2 (stereo). 881 882 ``in|out.format=format`` 883 Specify the sample format to use when using fixed-settings. 884 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``, 885 ``u32``, ``f32``. Default is ``s16``. 886 887 ``in|out.voices=voices`` 888 Specify the number of voices to use. Default is 1. 889 890 ``in|out.buffer-length=usecs`` 891 Sets the size of the buffer in microseconds. 892 893``-audiodev none,id=id[,prop[=value][,...]]`` 894 Creates a dummy backend that discards all outputs. This backend has 895 no backend specific properties. 896 897``-audiodev alsa,id=id[,prop[=value][,...]]`` 898 Creates backend using the ALSA. This backend is only available on 899 Linux. 900 901 ALSA specific options are: 902 903 ``in|out.dev=device`` 904 Specify the ALSA device to use for input and/or output. Default 905 is ``default``. 906 907 ``in|out.period-length=usecs`` 908 Sets the period length in microseconds. 909 910 ``in|out.try-poll=on|off`` 911 Attempt to use poll mode with the device. Default is on. 912 913 ``threshold=threshold`` 914 Threshold (in microseconds) when playback starts. Default is 0. 915 916``-audiodev coreaudio,id=id[,prop[=value][,...]]`` 917 Creates a backend using Apple's Core Audio. This backend is only 918 available on Mac OS and only supports playback. 919 920 Core Audio specific options are: 921 922 ``in|out.buffer-count=count`` 923 Sets the count of the buffers. 924 925``-audiodev dsound,id=id[,prop[=value][,...]]`` 926 Creates a backend using Microsoft's DirectSound. This backend is 927 only available on Windows and only supports playback. 928 929 DirectSound specific options are: 930 931 ``latency=usecs`` 932 Add extra usecs microseconds latency to playback. Default is 933 10000 (10 ms). 934 935``-audiodev oss,id=id[,prop[=value][,...]]`` 936 Creates a backend using OSS. This backend is available on most 937 Unix-like systems. 938 939 OSS specific options are: 940 941 ``in|out.dev=device`` 942 Specify the file name of the OSS device to use. Default is 943 ``/dev/dsp``. 944 945 ``in|out.buffer-count=count`` 946 Sets the count of the buffers. 947 948 ``in|out.try-poll=on|of`` 949 Attempt to use poll mode with the device. Default is on. 950 951 ``try-mmap=on|off`` 952 Try using memory mapped device access. Default is off. 953 954 ``exclusive=on|off`` 955 Open the device in exclusive mode (vmix won't work in this 956 case). Default is off. 957 958 ``dsp-policy=policy`` 959 Sets the timing policy (between 0 and 10, where smaller number 960 means smaller latency but higher CPU usage). Use -1 to use 961 buffer sizes specified by ``buffer`` and ``buffer-count``. This 962 option is ignored if you do not have OSS 4. Default is 5. 963 964``-audiodev pa,id=id[,prop[=value][,...]]`` 965 Creates a backend using PulseAudio. This backend is available on 966 most systems. 967 968 PulseAudio specific options are: 969 970 ``server=server`` 971 Sets the PulseAudio server to connect to. 972 973 ``in|out.name=sink`` 974 Use the specified source/sink for recording/playback. 975 976 ``in|out.latency=usecs`` 977 Desired latency in microseconds. The PulseAudio server will try 978 to honor this value but actual latencies may be lower or higher. 979 980``-audiodev pipewire,id=id[,prop[=value][,...]]`` 981 Creates a backend using PipeWire. This backend is available on 982 most systems. 983 984 PipeWire specific options are: 985 986 ``in|out.latency=usecs`` 987 Desired latency in microseconds. 988 989 ``in|out.name=sink`` 990 Use the specified source/sink for recording/playback. 991 992 ``in|out.stream-name`` 993 Specify the name of pipewire stream. 994 995``-audiodev sdl,id=id[,prop[=value][,...]]`` 996 Creates a backend using SDL. This backend is available on most 997 systems, but you should use your platform's native backend if 998 possible. 999 1000 SDL specific options are: 1001 1002 ``in|out.buffer-count=count`` 1003 Sets the count of the buffers. 1004 1005``-audiodev sndio,id=id[,prop[=value][,...]]`` 1006 Creates a backend using SNDIO. This backend is available on 1007 OpenBSD and most other Unix-like systems. 1008 1009 Sndio specific options are: 1010 1011 ``in|out.dev=device`` 1012 Specify the sndio device to use for input and/or output. Default 1013 is ``default``. 1014 1015 ``in|out.latency=usecs`` 1016 Sets the desired period length in microseconds. 1017 1018``-audiodev spice,id=id[,prop[=value][,...]]`` 1019 Creates a backend that sends audio through SPICE. This backend 1020 requires ``-spice`` and automatically selected in that case, so 1021 usually you can ignore this option. This backend has no backend 1022 specific properties. 1023 1024``-audiodev wav,id=id[,prop[=value][,...]]`` 1025 Creates a backend that writes audio to a WAV file. 1026 1027 Backend specific options are: 1028 1029 ``path=path`` 1030 Write recorded audio into the specified file. Default is 1031 ``qemu.wav``. 1032ERST 1033 1034DEF("device", HAS_ARG, QEMU_OPTION_device, 1035 "-device driver[,prop[=value][,...]]\n" 1036 " add device (based on driver)\n" 1037 " prop=value,... sets driver properties\n" 1038 " use '-device help' to print all possible drivers\n" 1039 " use '-device driver,help' to print all possible properties\n", 1040 QEMU_ARCH_ALL) 1041SRST 1042``-device driver[,prop[=value][,...]]`` 1043 Add device driver. prop=value sets driver properties. Valid 1044 properties depend on the driver. To get help on possible drivers and 1045 properties, use ``-device help`` and ``-device driver,help``. 1046 1047 Some drivers are: 1048 1049``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]`` 1050 Add an IPMI BMC. This is a simulation of a hardware management 1051 interface processor that normally sits on a system. It provides a 1052 watchdog and the ability to reset and power control the system. You 1053 need to connect this to an IPMI interface to make it useful 1054 1055 The IPMI slave address to use for the BMC. The default is 0x20. This 1056 address is the BMC's address on the I2C network of management 1057 controllers. If you don't know what this means, it is safe to ignore 1058 it. 1059 1060 ``id=id`` 1061 The BMC id for interfaces to use this device. 1062 1063 ``slave_addr=val`` 1064 Define slave address to use for the BMC. The default is 0x20. 1065 1066 ``sdrfile=file`` 1067 file containing raw Sensor Data Records (SDR) data. The default 1068 is none. 1069 1070 ``fruareasize=val`` 1071 size of a Field Replaceable Unit (FRU) area. The default is 1072 1024. 1073 1074 ``frudatafile=file`` 1075 file containing raw Field Replaceable Unit (FRU) inventory data. 1076 The default is none. 1077 1078 ``guid=uuid`` 1079 value for the GUID for the BMC, in standard UUID format. If this 1080 is set, get "Get GUID" command to the BMC will return it. 1081 Otherwise "Get GUID" will return an error. 1082 1083``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]`` 1084 Add a connection to an external IPMI BMC simulator. Instead of 1085 locally emulating the BMC like the above item, instead connect to an 1086 external entity that provides the IPMI services. 1087 1088 A connection is made to an external BMC simulator. If you do this, 1089 it is strongly recommended that you use the "reconnect=" chardev 1090 option to reconnect to the simulator if the connection is lost. Note 1091 that if this is not used carefully, it can be a security issue, as 1092 the interface has the ability to send resets, NMIs, and power off 1093 the VM. It's best if QEMU makes a connection to an external 1094 simulator running on a secure port on localhost, so neither the 1095 simulator nor QEMU is exposed to any outside network. 1096 1097 See the "lanserv/README.vm" file in the OpenIPMI library for more 1098 details on the external interface. 1099 1100``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]`` 1101 Add a KCS IPMI interface on the ISA bus. This also adds a 1102 corresponding ACPI and SMBIOS entries, if appropriate. 1103 1104 ``bmc=id`` 1105 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern 1106 above. 1107 1108 ``ioport=val`` 1109 Define the I/O address of the interface. The default is 0xca0 1110 for KCS. 1111 1112 ``irq=val`` 1113 Define the interrupt to use. The default is 5. To disable 1114 interrupts, set this to 0. 1115 1116``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]`` 1117 Like the KCS interface, but defines a BT interface. The default port 1118 is 0xe4 and the default interrupt is 5. 1119 1120``-device pci-ipmi-kcs,bmc=id`` 1121 Add a KCS IPMI interface on the PCI bus. 1122 1123 ``bmc=id`` 1124 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 1125 1126``-device pci-ipmi-bt,bmc=id`` 1127 Like the KCS interface, but defines a BT interface on the PCI bus. 1128 1129``-device intel-iommu[,option=...]`` 1130 This is only supported by ``-machine q35``, which will enable Intel VT-d 1131 emulation within the guest. It supports below options: 1132 1133 ``intremap=on|off`` (default: auto) 1134 This enables interrupt remapping feature. It's required to enable 1135 complete x2apic. Currently it only supports kvm kernel-irqchip modes 1136 ``off`` or ``split``, while full kernel-irqchip is not yet supported. 1137 The default value is "auto", which will be decided by the mode of 1138 kernel-irqchip. 1139 1140 ``caching-mode=on|off`` (default: off) 1141 This enables caching mode for the VT-d emulated device. When 1142 caching-mode is enabled, each guest DMA buffer mapping will generate an 1143 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in 1144 a synchronous way. It is required for ``-device vfio-pci`` to work 1145 with the VT-d device, because host assigned devices requires to setup 1146 the DMA mapping on the host before guest DMA starts. 1147 1148 ``device-iotlb=on|off`` (default: off) 1149 This enables device-iotlb capability for the emulated VT-d device. So 1150 far virtio/vhost should be the only real user for this parameter, 1151 paired with ats=on configured for the device. 1152 1153 ``aw-bits=39|48`` (default: 39) 1154 This decides the address width of IOVA address space. The address 1155 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for 1156 4-level IOMMU page tables. 1157 1158 Please also refer to the wiki page for general scenarios of VT-d 1159 emulation in QEMU: https://wiki.qemu.org/Features/VT-d. 1160 1161ERST 1162 1163DEF("name", HAS_ARG, QEMU_OPTION_name, 1164 "-name string1[,process=string2][,debug-threads=on|off]\n" 1165 " set the name of the guest\n" 1166 " string1 sets the window title and string2 the process name\n" 1167 " When debug-threads is enabled, individual threads are given a separate name\n" 1168 " NOTE: The thread names are for debugging and not a stable API.\n", 1169 QEMU_ARCH_ALL) 1170SRST 1171``-name name`` 1172 Sets the name of the guest. This name will be displayed in the SDL 1173 window caption. The name will also be used for the VNC server. Also 1174 optionally set the top visible process name in Linux. Naming of 1175 individual threads can also be enabled on Linux to aid debugging. 1176ERST 1177 1178DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 1179 "-uuid %08x-%04x-%04x-%04x-%012x\n" 1180 " specify machine UUID\n", QEMU_ARCH_ALL) 1181SRST 1182``-uuid uuid`` 1183 Set system UUID. 1184ERST 1185 1186DEFHEADING() 1187 1188DEFHEADING(Block device options:) 1189 1190SRST 1191The QEMU block device handling options have a long history and 1192have gone through several iterations as the feature set and complexity 1193of the block layer have grown. Many online guides to QEMU often 1194reference older and deprecated options, which can lead to confusion. 1195 1196The most explicit way to describe disks is to use a combination of 1197``-device`` to specify the hardware device and ``-blockdev`` to 1198describe the backend. The device defines what the guest sees and the 1199backend describes how QEMU handles the data. It is the only guaranteed 1200stable interface for describing block devices and as such is 1201recommended for management tools and scripting. 1202 1203The ``-drive`` option combines the device and backend into a single 1204command line option which is a more human friendly. There is however no 1205interface stability guarantee although some older board models still 1206need updating to work with the modern blockdev forms. 1207 1208Older options like ``-hda`` are essentially macros which expand into 1209``-drive`` options for various drive interfaces. The original forms 1210bake in a lot of assumptions from the days when QEMU was emulating a 1211legacy PC, they are not recommended for modern configurations. 1212 1213ERST 1214 1215DEF("fda", HAS_ARG, QEMU_OPTION_fda, 1216 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 1217DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 1218SRST 1219``-fda file`` 1220 \ 1221``-fdb file`` 1222 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in 1223 the System Emulation Users Guide). 1224ERST 1225 1226DEF("hda", HAS_ARG, QEMU_OPTION_hda, 1227 "-hda/-hdb file use 'file' as hard disk 0/1 image\n", QEMU_ARCH_ALL) 1228DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 1229DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 1230 "-hdc/-hdd file use 'file' as hard disk 2/3 image\n", QEMU_ARCH_ALL) 1231DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 1232SRST 1233``-hda file`` 1234 \ 1235``-hdb file`` 1236 \ 1237``-hdc file`` 1238 \ 1239``-hdd file`` 1240 Use file as hard disk 0, 1, 2 or 3 image on the default bus of the 1241 emulated machine (this is for example the IDE bus on most x86 machines, 1242 but it can also be SCSI, virtio or something else on other target 1243 architectures). See also the :ref:`disk images` chapter in the System 1244 Emulation Users Guide. 1245ERST 1246 1247DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 1248 "-cdrom file use 'file' as CD-ROM image\n", 1249 QEMU_ARCH_ALL) 1250SRST 1251``-cdrom file`` 1252 Use file as CD-ROM image on the default bus of the emulated machine 1253 (which is IDE1 master on x86, so you cannot use ``-hdc`` and ``-cdrom`` 1254 at the same time there). On systems that support it, you can use the 1255 host CD-ROM by using ``/dev/cdrom`` as filename. 1256ERST 1257 1258DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 1259 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 1260 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 1261 " [,read-only=on|off][,auto-read-only=on|off]\n" 1262 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 1263 " [,driver specific parameters...]\n" 1264 " configure a block backend\n", QEMU_ARCH_ALL) 1265SRST 1266``-blockdev option[,option[,option[,...]]]`` 1267 Define a new block driver node. Some of the options apply to all 1268 block drivers, other options are only accepted for a specific block 1269 driver. See below for a list of generic options and options for the 1270 most common block drivers. 1271 1272 Options that expect a reference to another node (e.g. ``file``) can 1273 be given in two ways. Either you specify the node name of an already 1274 existing node (file=node-name), or you define a new node inline, 1275 adding options for the referenced node after a dot 1276 (file.filename=path,file.aio=native). 1277 1278 A block driver node created with ``-blockdev`` can be used for a 1279 guest device by specifying its node name for the ``drive`` property 1280 in a ``-device`` argument that defines a block device. 1281 1282 ``Valid options for any block driver node:`` 1283 ``driver`` 1284 Specifies the block driver to use for the given node. 1285 1286 ``node-name`` 1287 This defines the name of the block driver node by which it 1288 will be referenced later. The name must be unique, i.e. it 1289 must not match the name of a different block driver node, or 1290 (if you use ``-drive`` as well) the ID of a drive. 1291 1292 If no node name is specified, it is automatically generated. 1293 The generated node name is not intended to be predictable 1294 and changes between QEMU invocations. For the top level, an 1295 explicit node name must be specified. 1296 1297 ``read-only`` 1298 Open the node read-only. Guest write attempts will fail. 1299 1300 Note that some block drivers support only read-only access, 1301 either generally or in certain configurations. In this case, 1302 the default value ``read-only=off`` does not work and the 1303 option must be specified explicitly. 1304 1305 ``auto-read-only`` 1306 If ``auto-read-only=on`` is set, QEMU may fall back to 1307 read-only usage even when ``read-only=off`` is requested, or 1308 even switch between modes as needed, e.g. depending on 1309 whether the image file is writable or whether a writing user 1310 is attached to the node. 1311 1312 ``force-share`` 1313 Override the image locking system of QEMU by forcing the 1314 node to utilize weaker shared access for permissions where 1315 it would normally request exclusive access. When there is 1316 the potential for multiple instances to have the same file 1317 open (whether this invocation of QEMU is the first or the 1318 second instance), both instances must permit shared access 1319 for the second instance to succeed at opening the file. 1320 1321 Enabling ``force-share=on`` requires ``read-only=on``. 1322 1323 ``cache.direct`` 1324 The host page cache can be avoided with ``cache.direct=on``. 1325 This will attempt to do disk IO directly to the guest's 1326 memory. QEMU may still perform an internal copy of the data. 1327 1328 ``cache.no-flush`` 1329 In case you don't care about data integrity over host 1330 failures, you can use ``cache.no-flush=on``. This option 1331 tells QEMU that it never needs to write any data to the disk 1332 but can instead keep things in cache. If anything goes 1333 wrong, like your host losing power, the disk storage getting 1334 disconnected accidentally, etc. your image will most 1335 probably be rendered unusable. 1336 1337 ``discard=discard`` 1338 discard is one of "ignore" (or "off") or "unmap" (or "on") 1339 and controls whether ``discard`` (also known as ``trim`` or 1340 ``unmap``) requests are ignored or passed to the filesystem. 1341 Some machine types may not support discard requests. 1342 1343 ``detect-zeroes=detect-zeroes`` 1344 detect-zeroes is "off", "on" or "unmap" and enables the 1345 automatic conversion of plain zero writes by the OS to 1346 driver specific optimized zero write commands. You may even 1347 choose "unmap" if discard is set to "unmap" to allow a zero 1348 write to be converted to an ``unmap`` operation. 1349 1350 ``Driver-specific options for file`` 1351 This is the protocol-level block driver for accessing regular 1352 files. 1353 1354 ``filename`` 1355 The path to the image file in the local filesystem 1356 1357 ``aio`` 1358 Specifies the AIO backend (threads/native/io_uring, 1359 default: threads) 1360 1361 ``locking`` 1362 Specifies whether the image file is protected with Linux OFD 1363 / POSIX locks. The default is to use the Linux Open File 1364 Descriptor API if available, otherwise no lock is applied. 1365 (auto/on/off, default: auto) 1366 1367 Example: 1368 1369 :: 1370 1371 -blockdev driver=file,node-name=disk,filename=disk.img 1372 1373 ``Driver-specific options for raw`` 1374 This is the image format block driver for raw images. It is 1375 usually stacked on top of a protocol level block driver such as 1376 ``file``. 1377 1378 ``file`` 1379 Reference to or definition of the data source block driver 1380 node (e.g. a ``file`` driver node) 1381 1382 Example 1: 1383 1384 :: 1385 1386 -blockdev driver=file,node-name=disk_file,filename=disk.img 1387 -blockdev driver=raw,node-name=disk,file=disk_file 1388 1389 Example 2: 1390 1391 :: 1392 1393 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1394 1395 ``Driver-specific options for qcow2`` 1396 This is the image format block driver for qcow2 images. It is 1397 usually stacked on top of a protocol level block driver such as 1398 ``file``. 1399 1400 ``file`` 1401 Reference to or definition of the data source block driver 1402 node (e.g. a ``file`` driver node) 1403 1404 ``backing`` 1405 Reference to or definition of the backing file block device 1406 (default is taken from the image file). It is allowed to 1407 pass ``null`` here in order to disable the default backing 1408 file. 1409 1410 ``lazy-refcounts`` 1411 Whether to enable the lazy refcounts feature (on/off; 1412 default is taken from the image file) 1413 1414 ``cache-size`` 1415 The maximum total size of the L2 table and refcount block 1416 caches in bytes (default: the sum of l2-cache-size and 1417 refcount-cache-size) 1418 1419 ``l2-cache-size`` 1420 The maximum size of the L2 table cache in bytes (default: if 1421 cache-size is not specified - 32M on Linux platforms, and 8M 1422 on non-Linux platforms; otherwise, as large as possible 1423 within the cache-size, while permitting the requested or the 1424 minimal refcount cache size) 1425 1426 ``refcount-cache-size`` 1427 The maximum size of the refcount block cache in bytes 1428 (default: 4 times the cluster size; or if cache-size is 1429 specified, the part of it which is not used for the L2 1430 cache) 1431 1432 ``cache-clean-interval`` 1433 Clean unused entries in the L2 and refcount caches. The 1434 interval is in seconds. The default value is 600 on 1435 supporting platforms, and 0 on other platforms. Setting it 1436 to 0 disables this feature. 1437 1438 ``pass-discard-request`` 1439 Whether discard requests to the qcow2 device should be 1440 forwarded to the data source (on/off; default: on if 1441 discard=unmap is specified, off otherwise) 1442 1443 ``pass-discard-snapshot`` 1444 Whether discard requests for the data source should be 1445 issued when a snapshot operation (e.g. deleting a snapshot) 1446 frees clusters in the qcow2 file (on/off; default: on) 1447 1448 ``pass-discard-other`` 1449 Whether discard requests for the data source should be 1450 issued on other occasions where a cluster gets freed 1451 (on/off; default: off) 1452 1453 ``discard-no-unref`` 1454 When enabled, discards from the guest will not cause cluster 1455 allocations to be relinquished. This prevents qcow2 fragmentation 1456 that would be caused by such discards. Besides potential 1457 performance degradation, such fragmentation can lead to increased 1458 allocation of clusters past the end of the image file, 1459 resulting in image files whose file length can grow much larger 1460 than their guest disk size would suggest. 1461 If image file length is of concern (e.g. when storing qcow2 1462 images directly on block devices), you should consider enabling 1463 this option. 1464 1465 ``overlap-check`` 1466 Which overlap checks to perform for writes to the image 1467 (none/constant/cached/all; default: cached). For details or 1468 finer granularity control refer to the QAPI documentation of 1469 ``blockdev-add``. 1470 1471 Example 1: 1472 1473 :: 1474 1475 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1476 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1477 1478 Example 2: 1479 1480 :: 1481 1482 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1483 1484 ``Driver-specific options for other drivers`` 1485 Please refer to the QAPI documentation of the ``blockdev-add`` 1486 QMP command. 1487ERST 1488 1489DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1490 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1491 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1492 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1493 " [,werror=ignore|stop|report|enospc][,id=name]\n" 1494 " [,aio=threads|native|io_uring]\n" 1495 " [,readonly=on|off][,copy-on-read=on|off]\n" 1496 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1497 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1498 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1499 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1500 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1501 " [[,iops_size=is]]\n" 1502 " [[,group=g]]\n" 1503 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1504SRST 1505``-drive option[,option[,option[,...]]]`` 1506 Define a new drive. This includes creating a block driver node (the 1507 backend) as well as a guest device, and is mostly a shortcut for 1508 defining the corresponding ``-blockdev`` and ``-device`` options. 1509 1510 ``-drive`` accepts all options that are accepted by ``-blockdev``. 1511 In addition, it knows the following options: 1512 1513 ``file=file`` 1514 This option defines which disk image (see the :ref:`disk images` 1515 chapter in the System Emulation Users Guide) to use with this drive. 1516 If the filename contains comma, you must double it (for instance, 1517 "file=my,,file" to use file "my,file"). 1518 1519 Special files such as iSCSI devices can be specified using 1520 protocol specific URLs. See the section for "Device URL Syntax" 1521 for more information. 1522 1523 ``if=interface`` 1524 This option defines on which type on interface the drive is 1525 connected. Available types are: ide, scsi, sd, mtd, floppy, 1526 pflash, virtio, none. 1527 1528 ``bus=bus,unit=unit`` 1529 These options define where is connected the drive by defining 1530 the bus number and the unit id. 1531 1532 ``index=index`` 1533 This option defines where the drive is connected by using an 1534 index in the list of available connectors of a given interface 1535 type. 1536 1537 ``media=media`` 1538 This option defines the type of the media: disk or cdrom. 1539 1540 ``snapshot=snapshot`` 1541 snapshot is "on" or "off" and controls snapshot mode for the 1542 given drive (see ``-snapshot``). 1543 1544 ``cache=cache`` 1545 cache is "none", "writeback", "unsafe", "directsync" or 1546 "writethrough" and controls how the host cache is used to access 1547 block data. This is a shortcut that sets the ``cache.direct`` 1548 and ``cache.no-flush`` options (as in ``-blockdev``), and 1549 additionally ``cache.writeback``, which provides a default for 1550 the ``write-cache`` option of block guest devices (as in 1551 ``-device``). The modes correspond to the following settings: 1552 1553 ============= =============== ============ ============== 1554 \ cache.writeback cache.direct cache.no-flush 1555 ============= =============== ============ ============== 1556 writeback on off off 1557 none on on off 1558 writethrough off off off 1559 directsync off on off 1560 unsafe on off on 1561 ============= =============== ============ ============== 1562 1563 The default mode is ``cache=writeback``. 1564 1565 ``aio=aio`` 1566 aio is "threads", "native", or "io_uring" and selects between pthread 1567 based disk I/O, native Linux AIO, or Linux io_uring API. 1568 1569 ``format=format`` 1570 Specify which disk format will be used rather than detecting the 1571 format. Can be used to specify format=raw to avoid interpreting 1572 an untrusted format header. 1573 1574 ``werror=action,rerror=action`` 1575 Specify which action to take on write and read errors. Valid 1576 actions are: "ignore" (ignore the error and try to continue), 1577 "stop" (pause QEMU), "report" (report the error to the guest), 1578 "enospc" (pause QEMU only if the host disk is full; report the 1579 error to the guest otherwise). The default setting is 1580 ``werror=enospc`` and ``rerror=report``. 1581 1582 ``copy-on-read=copy-on-read`` 1583 copy-on-read is "on" or "off" and enables whether to copy read 1584 backing file sectors into the image file. 1585 1586 ``bps=b,bps_rd=r,bps_wr=w`` 1587 Specify bandwidth throttling limits in bytes per second, either 1588 for all request types or for reads or writes only. Small values 1589 can lead to timeouts or hangs inside the guest. A safe minimum 1590 for disks is 2 MB/s. 1591 1592 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm`` 1593 Specify bursts in bytes per second, either for all request types 1594 or for reads or writes only. Bursts allow the guest I/O to spike 1595 above the limit temporarily. 1596 1597 ``iops=i,iops_rd=r,iops_wr=w`` 1598 Specify request rate limits in requests per second, either for 1599 all request types or for reads or writes only. 1600 1601 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm`` 1602 Specify bursts in requests per second, either for all request 1603 types or for reads or writes only. Bursts allow the guest I/O to 1604 spike above the limit temporarily. 1605 1606 ``iops_size=is`` 1607 Let every is bytes of a request count as a new request for iops 1608 throttling purposes. Use this option to prevent guests from 1609 circumventing iops limits by sending fewer but larger requests. 1610 1611 ``group=g`` 1612 Join a throttling quota group with given name g. All drives that 1613 are members of the same group are accounted for together. Use 1614 this option to prevent guests from circumventing throttling 1615 limits by using many small disks instead of a single larger 1616 disk. 1617 1618 By default, the ``cache.writeback=on`` mode is used. It will report 1619 data writes as completed as soon as the data is present in the host 1620 page cache. This is safe as long as your guest OS makes sure to 1621 correctly flush disk caches where needed. If your guest OS does not 1622 handle volatile disk write caches correctly and your host crashes or 1623 loses power, then the guest may experience data corruption. 1624 1625 For such guests, you should consider using ``cache.writeback=off``. 1626 This means that the host page cache will be used to read and write 1627 data, but write notification will be sent to the guest only after 1628 QEMU has made sure to flush each write to the disk. Be aware that 1629 this has a major impact on performance. 1630 1631 When using the ``-snapshot`` option, unsafe caching is always used. 1632 1633 Copy-on-read avoids accessing the same backing file sectors 1634 repeatedly and is useful when the backing file is over a slow 1635 network. By default copy-on-read is off. 1636 1637 Instead of ``-cdrom`` you can use: 1638 1639 .. parsed-literal:: 1640 1641 |qemu_system| -drive file=file,index=2,media=cdrom 1642 1643 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use: 1644 1645 .. parsed-literal:: 1646 1647 |qemu_system| -drive file=file,index=0,media=disk 1648 |qemu_system| -drive file=file,index=1,media=disk 1649 |qemu_system| -drive file=file,index=2,media=disk 1650 |qemu_system| -drive file=file,index=3,media=disk 1651 1652 You can open an image using pre-opened file descriptors from an fd 1653 set: 1654 1655 .. parsed-literal:: 1656 1657 |qemu_system| \\ 1658 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 1659 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 1660 -drive file=/dev/fdset/2,index=0,media=disk 1661 1662 You can connect a CDROM to the slave of ide0: 1663 1664 .. parsed-literal:: 1665 1666 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom 1667 1668 If you don't specify the "file=" argument, you define an empty 1669 drive: 1670 1671 .. parsed-literal:: 1672 1673 |qemu_system_x86| -drive if=ide,index=1,media=cdrom 1674 1675 Instead of ``-fda``, ``-fdb``, you can use: 1676 1677 .. parsed-literal:: 1678 1679 |qemu_system_x86| -drive file=file,index=0,if=floppy 1680 |qemu_system_x86| -drive file=file,index=1,if=floppy 1681 1682 By default, interface is "ide" and index is automatically 1683 incremented: 1684 1685 .. parsed-literal:: 1686 1687 |qemu_system_x86| -drive file=a -drive file=b 1688 1689 is interpreted like: 1690 1691 .. parsed-literal:: 1692 1693 |qemu_system_x86| -hda a -hdb b 1694ERST 1695 1696DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1697 "-mtdblock file use 'file' as on-board Flash memory image\n", 1698 QEMU_ARCH_ALL) 1699SRST 1700``-mtdblock file`` 1701 Use file as on-board Flash memory image. 1702ERST 1703 1704DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1705 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1706SRST 1707``-sd file`` 1708 Use file as SecureDigital card image. 1709ERST 1710 1711DEF("snapshot", 0, QEMU_OPTION_snapshot, 1712 "-snapshot write to temporary files instead of disk image files\n", 1713 QEMU_ARCH_ALL) 1714SRST 1715``-snapshot`` 1716 Write to temporary files instead of disk image files. In this case, 1717 the raw disk image you use is not written back. You can however 1718 force the write back by pressing C-a s (see the :ref:`disk images` 1719 chapter in the System Emulation Users Guide). 1720 1721 .. warning:: 1722 snapshot is incompatible with ``-blockdev`` (instead use qemu-img 1723 to manually create snapshot images to attach to your blockdev). 1724 If you have mixed ``-blockdev`` and ``-drive`` declarations you 1725 can use the 'snapshot' property on your drive declarations 1726 instead of this global option. 1727 1728ERST 1729 1730DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1731 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1732 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n" 1733 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1734 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1735 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1736 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1737 " [[,throttling.iops-size=is]]\n" 1738 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly=on]\n" 1739 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly=on]\n" 1740 "-fsdev synth,id=id\n", 1741 QEMU_ARCH_ALL) 1742 1743SRST 1744``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly=on][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]`` 1745 \ 1746``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly=on]`` 1747 \ 1748``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly=on]`` 1749 \ 1750``-fsdev synth,id=id[,readonly=on]`` 1751 Define a new file system device. Valid options are: 1752 1753 ``local`` 1754 Accesses to the filesystem are done by QEMU. 1755 1756 ``proxy`` 1757 Accesses to the filesystem are done by virtfs-proxy-helper(1). This 1758 option is deprecated (since QEMU 8.1) and will be removed in a future 1759 version of QEMU. Use ``local`` instead. 1760 1761 ``synth`` 1762 Synthetic filesystem, only used by QTests. 1763 1764 ``id=id`` 1765 Specifies identifier for this device. 1766 1767 ``path=path`` 1768 Specifies the export path for the file system device. Files 1769 under this path will be available to the 9p client on the guest. 1770 1771 ``security_model=security_model`` 1772 Specifies the security model to be used for this export path. 1773 Supported security models are "passthrough", "mapped-xattr", 1774 "mapped-file" and "none". In "passthrough" security model, files 1775 are stored using the same credentials as they are created on the 1776 guest. This requires QEMU to run as root. In "mapped-xattr" 1777 security model, some of the file attributes like uid, gid, mode 1778 bits and link target are stored as file attributes. For 1779 "mapped-file" these attributes are stored in the hidden 1780 .virtfs\_metadata directory. Directories exported by this 1781 security model cannot interact with other unix tools. "none" 1782 security model is same as passthrough except the sever won't 1783 report failures if it fails to set file attributes like 1784 ownership. Security model is mandatory only for local fsdriver. 1785 Other fsdrivers (like proxy) don't take security model as a 1786 parameter. 1787 1788 ``writeout=writeout`` 1789 This is an optional argument. The only supported value is 1790 "immediate". This means that host page cache will be used to 1791 read and write data but write notification will be sent to the 1792 guest only when the data has been reported as written by the 1793 storage subsystem. 1794 1795 ``readonly=on`` 1796 Enables exporting 9p share as a readonly mount for guests. By 1797 default read-write access is given. 1798 1799 ``socket=socket`` 1800 Enables proxy filesystem driver to use passed socket file for 1801 communicating with virtfs-proxy-helper(1). 1802 1803 ``sock_fd=sock_fd`` 1804 Enables proxy filesystem driver to use passed socket descriptor 1805 for communicating with virtfs-proxy-helper(1). Usually a helper 1806 like libvirt will create socketpair and pass one of the fds as 1807 sock\_fd. 1808 1809 ``fmode=fmode`` 1810 Specifies the default mode for newly created files on the host. 1811 Works only with security models "mapped-xattr" and 1812 "mapped-file". 1813 1814 ``dmode=dmode`` 1815 Specifies the default mode for newly created directories on the 1816 host. Works only with security models "mapped-xattr" and 1817 "mapped-file". 1818 1819 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w`` 1820 Specify bandwidth throttling limits in bytes per second, either 1821 for all request types or for reads or writes only. 1822 1823 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm`` 1824 Specify bursts in bytes per second, either for all request types 1825 or for reads or writes only. Bursts allow the guest I/O to spike 1826 above the limit temporarily. 1827 1828 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w`` 1829 Specify request rate limits in requests per second, either for 1830 all request types or for reads or writes only. 1831 1832 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm`` 1833 Specify bursts in requests per second, either for all request 1834 types or for reads or writes only. Bursts allow the guest I/O to 1835 spike above the limit temporarily. 1836 1837 ``throttling.iops-size=is`` 1838 Let every is bytes of a request count as a new request for iops 1839 throttling purposes. 1840 1841 -fsdev option is used along with -device driver "virtio-9p-...". 1842 1843``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag`` 1844 Options for virtio-9p-... driver are: 1845 1846 ``type`` 1847 Specifies the variant to be used. Supported values are "pci", 1848 "ccw" or "device", depending on the machine type. 1849 1850 ``fsdev=id`` 1851 Specifies the id value specified along with -fsdev option. 1852 1853 ``mount_tag=mount_tag`` 1854 Specifies the tag name to be used by the guest to mount this 1855 export point. 1856ERST 1857 1858DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1859 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1860 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1861 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly=on]\n" 1862 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly=on]\n" 1863 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n", 1864 QEMU_ARCH_ALL) 1865 1866SRST 1867``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly=on] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]`` 1868 \ 1869``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1870 \ 1871``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1872 \ 1873``-virtfs synth,mount_tag=mount_tag`` 1874 Define a new virtual filesystem device and expose it to the guest using 1875 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain 1876 directory on host is made directly accessible by guest as a pass-through 1877 file system by using the 9P network protocol for communication between 1878 host and guests, if desired even accessible, shared by several guests 1879 simultaneously. 1880 1881 Note that ``-virtfs`` is actually just a convenience shortcut for its 1882 generalized form ``-fsdev -device virtio-9p-pci``. 1883 1884 The general form of pass-through file system options are: 1885 1886 ``local`` 1887 Accesses to the filesystem are done by QEMU. 1888 1889 ``proxy`` 1890 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1891 This option is deprecated (since QEMU 8.1) and will be removed in a 1892 future version of QEMU. Use ``local`` instead. 1893 1894 ``synth`` 1895 Synthetic filesystem, only used by QTests. 1896 1897 ``id=id`` 1898 Specifies identifier for the filesystem device 1899 1900 ``path=path`` 1901 Specifies the export path for the file system device. Files 1902 under this path will be available to the 9p client on the guest. 1903 1904 ``security_model=security_model`` 1905 Specifies the security model to be used for this export path. 1906 Supported security models are "passthrough", "mapped-xattr", 1907 "mapped-file" and "none". In "passthrough" security model, files 1908 are stored using the same credentials as they are created on the 1909 guest. This requires QEMU to run as root. In "mapped-xattr" 1910 security model, some of the file attributes like uid, gid, mode 1911 bits and link target are stored as file attributes. For 1912 "mapped-file" these attributes are stored in the hidden 1913 .virtfs\_metadata directory. Directories exported by this 1914 security model cannot interact with other unix tools. "none" 1915 security model is same as passthrough except the sever won't 1916 report failures if it fails to set file attributes like 1917 ownership. Security model is mandatory only for local fsdriver. 1918 Other fsdrivers (like proxy) don't take security model as a 1919 parameter. 1920 1921 ``writeout=writeout`` 1922 This is an optional argument. The only supported value is 1923 "immediate". This means that host page cache will be used to 1924 read and write data but write notification will be sent to the 1925 guest only when the data has been reported as written by the 1926 storage subsystem. 1927 1928 ``readonly=on`` 1929 Enables exporting 9p share as a readonly mount for guests. By 1930 default read-write access is given. 1931 1932 ``socket=socket`` 1933 Enables proxy filesystem driver to use passed socket file for 1934 communicating with virtfs-proxy-helper(1). Usually a helper like 1935 libvirt will create socketpair and pass one of the fds as 1936 sock\_fd. 1937 1938 ``sock_fd`` 1939 Enables proxy filesystem driver to use passed 'sock\_fd' as the 1940 socket descriptor for interfacing with virtfs-proxy-helper(1). 1941 1942 ``fmode=fmode`` 1943 Specifies the default mode for newly created files on the host. 1944 Works only with security models "mapped-xattr" and 1945 "mapped-file". 1946 1947 ``dmode=dmode`` 1948 Specifies the default mode for newly created directories on the 1949 host. Works only with security models "mapped-xattr" and 1950 "mapped-file". 1951 1952 ``mount_tag=mount_tag`` 1953 Specifies the tag name to be used by the guest to mount this 1954 export point. 1955 1956 ``multidevs=multidevs`` 1957 Specifies how to deal with multiple devices being shared with a 1958 9p export. Supported behaviours are either "remap", "forbid" or 1959 "warn". The latter is the default behaviour on which virtfs 9p 1960 expects only one device to be shared with the same export, and 1961 if more than one device is shared and accessed via the same 9p 1962 export then only a warning message is logged (once) by qemu on 1963 host side. In order to avoid file ID collisions on guest you 1964 should either create a separate virtfs export for each device to 1965 be shared with guests (recommended way) or you might use "remap" 1966 instead which allows you to share multiple devices with only one 1967 export instead, which is achieved by remapping the original 1968 inode numbers from host to guest in a way that would prevent 1969 such collisions. Remapping inodes in such use cases is required 1970 because the original device IDs from host are never passed and 1971 exposed on guest. Instead all files of an export shared with 1972 virtfs always share the same device id on guest. So two files 1973 with identical inode numbers but from actually different devices 1974 on host would otherwise cause a file ID collision and hence 1975 potential misbehaviours on guest. "forbid" on the other hand 1976 assumes like "warn" that only one device is shared by the same 1977 export, however it will not only log a warning message but also 1978 deny access to additional devices on guest. Note though that 1979 "forbid" does currently not block all possible file access 1980 operations (e.g. readdir() would still return entries from other 1981 devices). 1982ERST 1983 1984DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1985 "-iscsi [user=user][,password=password][,password-secret=secret-id]\n" 1986 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE]\n" 1987 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1988 " [,timeout=timeout]\n" 1989 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1990 1991SRST 1992``-iscsi`` 1993 Configure iSCSI session parameters. 1994ERST 1995 1996DEFHEADING() 1997 1998DEFHEADING(USB convenience options:) 1999 2000DEF("usb", 0, QEMU_OPTION_usb, 2001 "-usb enable on-board USB host controller (if not enabled by default)\n", 2002 QEMU_ARCH_ALL) 2003SRST 2004``-usb`` 2005 Enable USB emulation on machine types with an on-board USB host 2006 controller (if not enabled by default). Note that on-board USB host 2007 controllers may not support USB 3.0. In this case 2008 ``-device qemu-xhci`` can be used instead on machines with PCI. 2009ERST 2010 2011DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 2012 "-usbdevice name add the host or guest USB device 'name'\n", 2013 QEMU_ARCH_ALL) 2014SRST 2015``-usbdevice devname`` 2016 Add the USB device devname, and enable an on-board USB controller 2017 if possible and necessary (just like it can be done via 2018 ``-machine usb=on``). Note that this option is mainly intended for 2019 the user's convenience only. More fine-grained control can be 2020 achieved by selecting a USB host controller (if necessary) and the 2021 desired USB device via the ``-device`` option instead. For example, 2022 instead of using ``-usbdevice mouse`` it is possible to use 2023 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse 2024 to a USB 3.0 controller instead (at least on machines that support 2025 PCI and do not have an USB controller enabled by default yet). 2026 For more details, see the chapter about 2027 :ref:`Connecting USB devices` in the System Emulation Users Guide. 2028 Possible devices for devname are: 2029 2030 ``braille`` 2031 Braille device. This will use BrlAPI to display the braille 2032 output on a real or fake device (i.e. it also creates a 2033 corresponding ``braille`` chardev automatically beside the 2034 ``usb-braille`` USB device). 2035 2036 ``keyboard`` 2037 Standard USB keyboard. Will override the PS/2 keyboard (if present). 2038 2039 ``mouse`` 2040 Virtual Mouse. This will override the PS/2 mouse emulation when 2041 activated. 2042 2043 ``tablet`` 2044 Pointer device that uses absolute coordinates (like a 2045 touchscreen). This means QEMU is able to report the mouse 2046 position without having to grab the mouse. Also overrides the 2047 PS/2 mouse emulation when activated. 2048 2049 ``wacom-tablet`` 2050 Wacom PenPartner USB tablet. 2051 2052 2053ERST 2054 2055DEFHEADING() 2056 2057DEFHEADING(Display options:) 2058 2059DEF("display", HAS_ARG, QEMU_OPTION_display, 2060#if defined(CONFIG_SPICE) 2061 "-display spice-app[,gl=on|off]\n" 2062#endif 2063#if defined(CONFIG_SDL) 2064 "-display sdl[,gl=on|core|es|off][,grab-mod=<mod>][,show-cursor=on|off]\n" 2065 " [,window-close=on|off]\n" 2066#endif 2067#if defined(CONFIG_GTK) 2068 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n" 2069 " [,show-tabs=on|off][,show-cursor=on|off][,window-close=on|off]\n" 2070 " [,show-menubar=on|off]\n" 2071#endif 2072#if defined(CONFIG_VNC) 2073 "-display vnc=<display>[,<optargs>]\n" 2074#endif 2075#if defined(CONFIG_CURSES) 2076 "-display curses[,charset=<encoding>]\n" 2077#endif 2078#if defined(CONFIG_COCOA) 2079 "-display cocoa[,full-grab=on|off][,swap-opt-cmd=on|off]\n" 2080#endif 2081#if defined(CONFIG_OPENGL) 2082 "-display egl-headless[,rendernode=<file>]\n" 2083#endif 2084#if defined(CONFIG_DBUS_DISPLAY) 2085 "-display dbus[,addr=<dbusaddr>]\n" 2086 " [,gl=on|core|es|off][,rendernode=<file>]\n" 2087#endif 2088#if defined(CONFIG_COCOA) 2089 "-display cocoa[,show-cursor=on|off][,left-command-key=on|off]\n" 2090#endif 2091 "-display none\n" 2092 " select display backend type\n" 2093 " The default display is equivalent to\n " 2094#if defined(CONFIG_GTK) 2095 "\"-display gtk\"\n" 2096#elif defined(CONFIG_SDL) 2097 "\"-display sdl\"\n" 2098#elif defined(CONFIG_COCOA) 2099 "\"-display cocoa\"\n" 2100#elif defined(CONFIG_VNC) 2101 "\"-vnc localhost:0,to=99,id=default\"\n" 2102#else 2103 "\"-display none\"\n" 2104#endif 2105 , QEMU_ARCH_ALL) 2106SRST 2107``-display type`` 2108 Select type of display to use. Use ``-display help`` to list the available 2109 display types. Valid values for type are 2110 2111 ``spice-app[,gl=on|off]`` 2112 Start QEMU as a Spice server and launch the default Spice client 2113 application. The Spice server will redirect the serial consoles 2114 and QEMU monitors. (Since 4.0) 2115 2116 ``dbus`` 2117 Export the display over D-Bus interfaces. (Since 7.0) 2118 2119 The connection is registered with the "org.qemu" name (and queued when 2120 already owned). 2121 2122 ``addr=<dbusaddr>`` : D-Bus bus address to connect to. 2123 2124 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``. 2125 2126 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface 2127 will share framebuffers with DMABUF file descriptors). 2128 2129 ``sdl`` 2130 Display video output via SDL (usually in a separate graphics 2131 window; see the SDL documentation for other possibilities). 2132 Valid parameters are: 2133 2134 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling 2135 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be 2136 either ``lshift-lctrl-lalt`` or ``rctrl``. 2137 2138 ``gl=on|off|core|es`` : Use OpenGL for displaying 2139 2140 ``show-cursor=on|off`` : Force showing the mouse cursor 2141 2142 ``window-close=on|off`` : Allow to quit qemu with window close button 2143 2144 ``gtk`` 2145 Display video output in a GTK window. This interface provides 2146 drop-down menus and other UI elements to configure and control 2147 the VM during runtime. Valid parameters are: 2148 2149 ``full-screen=on|off`` : Start in fullscreen mode 2150 2151 ``gl=on|off`` : Use OpenGL for displaying 2152 2153 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover 2154 2155 ``show-tabs=on|off`` : Display the tab bar for switching between the 2156 various graphical interfaces (e.g. VGA and 2157 virtual console character devices) by default. 2158 2159 ``show-cursor=on|off`` : Force showing the mouse cursor 2160 2161 ``window-close=on|off`` : Allow to quit qemu with window close button 2162 2163 ``show-menubar=on|off`` : Display the main window menubar, defaults to "on" 2164 2165 ``zoom-to-fit=on|off`` : Expand video output to the window size, 2166 defaults to "off" 2167 2168 ``curses[,charset=<encoding>]`` 2169 Display video output via curses. For graphics device models 2170 which support a text mode, QEMU can display this output using a 2171 curses/ncurses interface. Nothing is displayed when the graphics 2172 device is in graphical mode or if the graphics device does not 2173 support a text mode. Generally only the VGA device models 2174 support text mode. The font charset used by the guest can be 2175 specified with the ``charset`` option, for example 2176 ``charset=CP850`` for IBM CP850 encoding. The default is 2177 ``CP437``. 2178 2179 ``cocoa`` 2180 Display video output in a Cocoa window. Mac only. This interface 2181 provides drop-down menus and other UI elements to configure and 2182 control the VM during runtime. Valid parameters are: 2183 2184 ``show-cursor=on|off`` : Force showing the mouse cursor 2185 2186 ``left-command-key=on|off`` : Disable forwarding left command key to host 2187 2188 ``egl-headless[,rendernode=<file>]`` 2189 Offload all OpenGL operations to a local DRI device. For any 2190 graphical display, this display needs to be paired with either 2191 VNC or SPICE displays. 2192 2193 ``vnc=<display>`` 2194 Start a VNC server on display <display> 2195 2196 ``none`` 2197 Do not display video output. The guest will still see an 2198 emulated graphics card, but its output will not be displayed to 2199 the QEMU user. This option differs from the -nographic option in 2200 that it only affects what is done with video output; -nographic 2201 also changes the destination of the serial and parallel port 2202 data. 2203ERST 2204 2205DEF("nographic", 0, QEMU_OPTION_nographic, 2206 "-nographic disable graphical output and redirect serial I/Os to console\n", 2207 QEMU_ARCH_ALL) 2208SRST 2209``-nographic`` 2210 Normally, if QEMU is compiled with graphical window support, it 2211 displays output such as guest graphics, guest console, and the QEMU 2212 monitor in a window. With this option, you can totally disable 2213 graphical output so that QEMU is a simple command line application. 2214 The emulated serial port is redirected on the console and muxed with 2215 the monitor (unless redirected elsewhere explicitly). Therefore, you 2216 can still use QEMU to debug a Linux kernel with a serial console. 2217 Use C-a h for help on switching between the console and monitor. 2218ERST 2219 2220#ifdef CONFIG_SPICE 2221DEF("spice", HAS_ARG, QEMU_OPTION_spice, 2222 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 2223 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 2224 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 2225 " [,x509-dh-key-file=<file>][,addr=addr]\n" 2226 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n" 2227 " [,tls-ciphers=<list>]\n" 2228 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 2229 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 2230 " [,sasl=on|off][,disable-ticketing=on|off]\n" 2231 " [,password-secret=<secret-id>]\n" 2232 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 2233 " [,jpeg-wan-compression=[auto|never|always]]\n" 2234 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 2235 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n" 2236 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n" 2237 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 2238 " [,gl=[on|off]][,rendernode=<file>]\n" 2239 " enable spice\n" 2240 " at least one of {port, tls-port} is mandatory\n", 2241 QEMU_ARCH_ALL) 2242#endif 2243SRST 2244``-spice option[,option[,...]]`` 2245 Enable the spice remote desktop protocol. Valid options are 2246 2247 ``port=<nr>`` 2248 Set the TCP port spice is listening on for plaintext channels. 2249 2250 ``addr=<addr>`` 2251 Set the IP address spice is listening on. Default is any 2252 address. 2253 2254 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off`` 2255 Force using the specified IP version. 2256 2257 ``password-secret=<secret-id>`` 2258 Set the ID of the ``secret`` object containing the password 2259 you need to authenticate. 2260 2261 ``sasl=on|off`` 2262 Require that the client use SASL to authenticate with the spice. 2263 The exact choice of authentication method used is controlled 2264 from the system / user's SASL configuration file for the 'qemu' 2265 service. This is typically found in /etc/sasl2/qemu.conf. If 2266 running QEMU as an unprivileged user, an environment variable 2267 SASL\_CONF\_PATH can be used to make it search alternate 2268 locations for the service config. While some SASL auth methods 2269 can also provide data encryption (eg GSSAPI), it is recommended 2270 that SASL always be combined with the 'tls' and 'x509' settings 2271 to enable use of SSL and server certificates. This ensures a 2272 data encryption preventing compromise of authentication 2273 credentials. 2274 2275 ``disable-ticketing=on|off`` 2276 Allow client connects without authentication. 2277 2278 ``disable-copy-paste=on|off`` 2279 Disable copy paste between the client and the guest. 2280 2281 ``disable-agent-file-xfer=on|off`` 2282 Disable spice-vdagent based file-xfer between the client and the 2283 guest. 2284 2285 ``tls-port=<nr>`` 2286 Set the TCP port spice is listening on for encrypted channels. 2287 2288 ``x509-dir=<dir>`` 2289 Set the x509 file directory. Expects same filenames as -vnc 2290 $display,x509=$dir 2291 2292 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>`` 2293 The x509 file names can also be configured individually. 2294 2295 ``tls-ciphers=<list>`` 2296 Specify which ciphers to use. 2297 2298 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]`` 2299 Force specific channel to be used with or without TLS 2300 encryption. The options can be specified multiple times to 2301 configure multiple channels. The special name "default" can be 2302 used to set the default mode. For channels which are not 2303 explicitly forced into one mode the spice client is allowed to 2304 pick tls/plaintext as he pleases. 2305 2306 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]`` 2307 Configure image compression (lossless). Default is auto\_glz. 2308 2309 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]`` 2310 Configure wan image compression (lossy for slow links). Default 2311 is auto. 2312 2313 ``streaming-video=[off|all|filter]`` 2314 Configure video stream detection. Default is off. 2315 2316 ``agent-mouse=[on|off]`` 2317 Enable/disable passing mouse events via vdagent. Default is on. 2318 2319 ``playback-compression=[on|off]`` 2320 Enable/disable audio stream compression (using celt 0.5.1). 2321 Default is on. 2322 2323 ``seamless-migration=[on|off]`` 2324 Enable/disable spice seamless migration. Default is off. 2325 2326 ``gl=[on|off]`` 2327 Enable/disable OpenGL context. Default is off. 2328 2329 ``rendernode=<file>`` 2330 DRM render node for OpenGL rendering. If not specified, it will 2331 pick the first available. (Since 2.9) 2332ERST 2333 2334DEF("portrait", 0, QEMU_OPTION_portrait, 2335 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 2336 QEMU_ARCH_ALL) 2337SRST 2338``-portrait`` 2339 Rotate graphical output 90 deg left (only PXA LCD). 2340ERST 2341 2342DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 2343 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 2344 QEMU_ARCH_ALL) 2345SRST 2346``-rotate deg`` 2347 Rotate graphical output some deg left (only PXA LCD). 2348ERST 2349 2350DEF("vga", HAS_ARG, QEMU_OPTION_vga, 2351 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 2352 " select video card type\n", QEMU_ARCH_ALL) 2353SRST 2354``-vga type`` 2355 Select type of VGA card to emulate. Valid values for type are 2356 2357 ``cirrus`` 2358 Cirrus Logic GD5446 Video card. All Windows versions starting 2359 from Windows 95 should recognize and use this graphic card. For 2360 optimal performances, use 16 bit color depth in the guest and 2361 the host OS. (This card was the default before QEMU 2.2) 2362 2363 ``std`` 2364 Standard VGA card with Bochs VBE extensions. If your guest OS 2365 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if 2366 you want to use high resolution modes (>= 1280x1024x16) then you 2367 should use this option. (This card is the default since QEMU 2368 2.2) 2369 2370 ``vmware`` 2371 VMWare SVGA-II compatible adapter. Use it if you have 2372 sufficiently recent XFree86/XOrg server or Windows guest with a 2373 driver for this card. 2374 2375 ``qxl`` 2376 QXL paravirtual graphic card. It is VGA compatible (including 2377 VESA 2.0 VBE support). Works best with qxl guest drivers 2378 installed though. Recommended choice when using the spice 2379 protocol. 2380 2381 ``tcx`` 2382 (sun4m only) Sun TCX framebuffer. This is the default 2383 framebuffer for sun4m machines and offers both 8-bit and 24-bit 2384 colour depths at a fixed resolution of 1024x768. 2385 2386 ``cg3`` 2387 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit 2388 framebuffer for sun4m machines available in both 1024x768 2389 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people 2390 wishing to run older Solaris versions. 2391 2392 ``virtio`` 2393 Virtio VGA card. 2394 2395 ``none`` 2396 Disable VGA card. 2397ERST 2398 2399DEF("full-screen", 0, QEMU_OPTION_full_screen, 2400 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 2401SRST 2402``-full-screen`` 2403 Start in full screen. 2404ERST 2405 2406DEF("g", HAS_ARG, QEMU_OPTION_g , 2407 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 2408 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 2409SRST 2410``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]`` 2411 Set the initial graphical resolution and depth (PPC, SPARC only). 2412 2413 For PPC the default is 800x600x32. 2414 2415 For SPARC with the TCX graphics device, the default is 1024x768x8 2416 with the option of 1024x768x24. For cgthree, the default is 2417 1024x768x8 with the option of 1152x900x8 for people who wish to use 2418 OBP. 2419ERST 2420 2421DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 2422 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 2423SRST 2424``-vnc display[,option[,option[,...]]]`` 2425 Normally, if QEMU is compiled with graphical window support, it 2426 displays output such as guest graphics, guest console, and the QEMU 2427 monitor in a window. With this option, you can have QEMU listen on 2428 VNC display display and redirect the VGA display over the VNC 2429 session. It is very useful to enable the usb tablet device when 2430 using this option (option ``-device usb-tablet``). When using the 2431 VNC display, you must use the ``-k`` parameter to set the keyboard 2432 layout if you are not using en-us. Valid syntax for the display is 2433 2434 ``to=L`` 2435 With this option, QEMU will try next available VNC displays, 2436 until the number L, if the origianlly defined "-vnc display" is 2437 not available, e.g. port 5900+display is already used by another 2438 application. By default, to=0. 2439 2440 ``host:d`` 2441 TCP connections will only be allowed from host on display d. By 2442 convention the TCP port is 5900+d. Optionally, host can be 2443 omitted in which case the server will accept connections from 2444 any host. 2445 2446 ``unix:path`` 2447 Connections will be allowed over UNIX domain sockets where path 2448 is the location of a unix socket to listen for connections on. 2449 2450 ``none`` 2451 VNC is initialized but not started. The monitor ``change`` 2452 command can be used to later start the VNC server. 2453 2454 Following the display value there may be one or more option flags 2455 separated by commas. Valid options are 2456 2457 ``reverse=on|off`` 2458 Connect to a listening VNC client via a "reverse" connection. 2459 The client is specified by the display. For reverse network 2460 connections (host:d,``reverse``), the d argument is a TCP port 2461 number, not a display number. 2462 2463 ``websocket=on|off`` 2464 Opens an additional TCP listening port dedicated to VNC 2465 Websocket connections. If a bare websocket option is given, the 2466 Websocket port is 5700+display. An alternative port can be 2467 specified with the syntax ``websocket``\ =port. 2468 2469 If host is specified connections will only be allowed from this 2470 host. It is possible to control the websocket listen address 2471 independently, using the syntax ``websocket``\ =host:port. 2472 2473 If no TLS credentials are provided, the websocket connection 2474 runs in unencrypted mode. If TLS credentials are provided, the 2475 websocket connection requires encrypted client connections. 2476 2477 ``password=on|off`` 2478 Require that password based authentication is used for client 2479 connections. 2480 2481 The password must be set separately using the ``set_password`` 2482 command in the :ref:`QEMU monitor`. The 2483 syntax to change your password is: 2484 ``set_password <protocol> <password>`` where <protocol> could be 2485 either "vnc" or "spice". 2486 2487 If you would like to change <protocol> password expiration, you 2488 should use ``expire_password <protocol> <expiration-time>`` 2489 where expiration time could be one of the following options: 2490 now, never, +seconds or UNIX time of expiration, e.g. +60 to 2491 make password expire in 60 seconds, or 1335196800 to make 2492 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for 2493 this date and time). 2494 2495 You can also use keywords "now" or "never" for the expiration 2496 time to allow <protocol> password to expire immediately or never 2497 expire. 2498 2499 ``password-secret=<secret-id>`` 2500 Require that password based authentication is used for client 2501 connections, using the password provided by the ``secret`` 2502 object identified by ``secret-id``. 2503 2504 ``tls-creds=ID`` 2505 Provides the ID of a set of TLS credentials to use to secure the 2506 VNC server. They will apply to both the normal VNC server socket 2507 and the websocket socket (if enabled). Setting TLS credentials 2508 will cause the VNC server socket to enable the VeNCrypt auth 2509 mechanism. The credentials should have been previously created 2510 using the ``-object tls-creds`` argument. 2511 2512 ``tls-authz=ID`` 2513 Provides the ID of the QAuthZ authorization object against which 2514 the client's x509 distinguished name will validated. This object 2515 is only resolved at time of use, so can be deleted and recreated 2516 on the fly while the VNC server is active. If missing, it will 2517 default to denying access. 2518 2519 ``sasl=on|off`` 2520 Require that the client use SASL to authenticate with the VNC 2521 server. The exact choice of authentication method used is 2522 controlled from the system / user's SASL configuration file for 2523 the 'qemu' service. This is typically found in 2524 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, 2525 an environment variable SASL\_CONF\_PATH can be used to make it 2526 search alternate locations for the service config. While some 2527 SASL auth methods can also provide data encryption (eg GSSAPI), 2528 it is recommended that SASL always be combined with the 'tls' 2529 and 'x509' settings to enable use of SSL and server 2530 certificates. This ensures a data encryption preventing 2531 compromise of authentication credentials. See the 2532 :ref:`VNC security` section in the System Emulation Users Guide 2533 for details on using SASL authentication. 2534 2535 ``sasl-authz=ID`` 2536 Provides the ID of the QAuthZ authorization object against which 2537 the client's SASL username will validated. This object is only 2538 resolved at time of use, so can be deleted and recreated on the 2539 fly while the VNC server is active. If missing, it will default 2540 to denying access. 2541 2542 ``acl=on|off`` 2543 Legacy method for enabling authorization of clients against the 2544 x509 distinguished name and SASL username. It results in the 2545 creation of two ``authz-list`` objects with IDs of 2546 ``vnc.username`` and ``vnc.x509dname``. The rules for these 2547 objects must be configured with the HMP ACL commands. 2548 2549 This option is deprecated and should no longer be used. The new 2550 ``sasl-authz`` and ``tls-authz`` options are a replacement. 2551 2552 ``lossy=on|off`` 2553 Enable lossy compression methods (gradient, JPEG, ...). If this 2554 option is set, VNC client may receive lossy framebuffer updates 2555 depending on its encoding settings. Enabling this option can 2556 save a lot of bandwidth at the expense of quality. 2557 2558 ``non-adaptive=on|off`` 2559 Disable adaptive encodings. Adaptive encodings are enabled by 2560 default. An adaptive encoding will try to detect frequently 2561 updated screen regions, and send updates in these regions using 2562 a lossy encoding (like JPEG). This can be really helpful to save 2563 bandwidth when playing videos. Disabling adaptive encodings 2564 restores the original static behavior of encodings like Tight. 2565 2566 ``share=[allow-exclusive|force-shared|ignore]`` 2567 Set display sharing policy. 'allow-exclusive' allows clients to 2568 ask for exclusive access. As suggested by the rfb spec this is 2569 implemented by dropping other connections. Connecting multiple 2570 clients in parallel requires all clients asking for a shared 2571 session (vncviewer: -shared switch). This is the default. 2572 'force-shared' disables exclusive client access. Useful for 2573 shared desktop sessions, where you don't want someone forgetting 2574 specify -shared disconnect everybody else. 'ignore' completely 2575 ignores the shared flag and allows everybody connect 2576 unconditionally. Doesn't conform to the rfb spec but is 2577 traditional QEMU behavior. 2578 2579 ``key-delay-ms`` 2580 Set keyboard delay, for key down and key up events, in 2581 milliseconds. Default is 10. Keyboards are low-bandwidth 2582 devices, so this slowdown can help the device and guest to keep 2583 up and not lose events in case events are arriving in bulk. 2584 Possible causes for the latter are flaky network connections, or 2585 scripts for automated testing. 2586 2587 ``audiodev=audiodev`` 2588 Use the specified audiodev when the VNC client requests audio 2589 transmission. When not using an -audiodev argument, this option 2590 must be omitted, otherwise is must be present and specify a 2591 valid audiodev. 2592 2593 ``power-control=on|off`` 2594 Permit the remote client to issue shutdown, reboot or reset power 2595 control requests. 2596ERST 2597 2598ARCHHEADING(, QEMU_ARCH_I386) 2599 2600ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2601 2602DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2603 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2604 QEMU_ARCH_I386) 2605SRST 2606``-win2k-hack`` 2607 Use it when installing Windows 2000 to avoid a disk full bug. After 2608 Windows 2000 is installed, you no longer need this option (this 2609 option slows down the IDE transfers). 2610ERST 2611 2612DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2613 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2614 QEMU_ARCH_I386) 2615SRST 2616``-no-fd-bootchk`` 2617 Disable boot signature checking for floppy disks in BIOS. May be 2618 needed to boot from old floppy disks. 2619ERST 2620 2621DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2622 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2623SRST 2624``-no-acpi`` 2625 Disable ACPI (Advanced Configuration and Power Interface) support. 2626 Use it if your guest OS complains about ACPI problems (PC target 2627 machine only). 2628ERST 2629 2630DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2631 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2632SRST 2633``-no-hpet`` 2634 Disable HPET support. Deprecated, use '-machine hpet=off' instead. 2635ERST 2636 2637DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2638 "-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" 2639 " ACPI table description\n", QEMU_ARCH_I386) 2640SRST 2641``-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]...]`` 2642 Add ACPI table with specified header fields and context from 2643 specified files. For file=, take whole ACPI table from the specified 2644 files, including all ACPI headers (possible overridden by other 2645 options). For data=, only data portion of the table is used, all 2646 header information is specified in the command line. If a SLIC table 2647 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id 2648 fields will override the same in the RSDT and the FADT (a.k.a. 2649 FACP), in order to ensure the field matches required by the 2650 Microsoft SLIC spec and the ACPI spec. 2651ERST 2652 2653DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2654 "-smbios file=binary\n" 2655 " load SMBIOS entry from binary file\n" 2656 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2657 " [,uefi=on|off]\n" 2658 " specify SMBIOS type 0 fields\n" 2659 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2660 " [,uuid=uuid][,sku=str][,family=str]\n" 2661 " specify SMBIOS type 1 fields\n" 2662 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2663 " [,asset=str][,location=str]\n" 2664 " specify SMBIOS type 2 fields\n" 2665 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2666 " [,sku=str]\n" 2667 " specify SMBIOS type 3 fields\n" 2668 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2669 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n" 2670 " [,processor-id=%d]\n" 2671 " specify SMBIOS type 4 fields\n" 2672 "-smbios type=8[,external_reference=str][,internal_reference=str][,connector_type=%d][,port_type=%d]\n" 2673 " specify SMBIOS type 8 fields\n" 2674 "-smbios type=11[,value=str][,path=filename]\n" 2675 " specify SMBIOS type 11 fields\n" 2676 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2677 " [,asset=str][,part=str][,speed=%d]\n" 2678 " specify SMBIOS type 17 fields\n" 2679 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n" 2680 " specify SMBIOS type 41 fields\n", 2681 QEMU_ARCH_I386 | QEMU_ARCH_ARM | QEMU_ARCH_LOONGARCH) 2682SRST 2683``-smbios file=binary`` 2684 Load SMBIOS entry from binary file. 2685 2686``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]`` 2687 Specify SMBIOS type 0 fields 2688 2689``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]`` 2690 Specify SMBIOS type 1 fields 2691 2692``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]`` 2693 Specify SMBIOS type 2 fields 2694 2695``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]`` 2696 Specify SMBIOS type 3 fields 2697 2698``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str][,processor-id=%d]`` 2699 Specify SMBIOS type 4 fields 2700 2701``-smbios type=11[,value=str][,path=filename]`` 2702 Specify SMBIOS type 11 fields 2703 2704 This argument can be repeated multiple times, and values are added in the order they are parsed. 2705 Applications intending to use OEM strings data are encouraged to use their application name as 2706 a prefix for the value string. This facilitates passing information for multiple applications 2707 concurrently. 2708 2709 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax 2710 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes. 2711 2712 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to 2713 the SMBIOS table in the order in which they appear. 2714 2715 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535 2716 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the 2717 guest. Instead it should be used as a indicator to inform the guest where to locate the real 2718 data set, for example, by specifying the serial ID of a block device. 2719 2720 An example passing three strings is 2721 2722 .. parsed-literal:: 2723 2724 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\ 2725 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\ 2726 path=/some/file/with/oemstringsdata.txt 2727 2728 In the guest OS this is visible with the ``dmidecode`` command 2729 2730 .. parsed-literal:: 2731 2732 $ dmidecode -t 11 2733 Handle 0x0E00, DMI type 11, 5 bytes 2734 OEM Strings 2735 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/ 2736 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os 2737 String 3: myapp:some extra data 2738 2739 2740``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]`` 2741 Specify SMBIOS type 17 fields 2742 2743``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]`` 2744 Specify SMBIOS type 41 fields 2745 2746 This argument can be repeated multiple times. Its main use is to allow network interfaces be created 2747 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface 2748 position on the PCI bus. 2749 2750 Here is an example of use: 2751 2752 .. parsed-literal:: 2753 2754 -netdev user,id=internet \\ 2755 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\ 2756 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev 2757 2758 In the guest OS, the device should then appear as ``eno1``: 2759 2760 ..parsed-literal:: 2761 2762 $ ip -brief l 2763 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP> 2764 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP> 2765 2766 Currently, the PCI device has to be attached to the root bus. 2767 2768ERST 2769 2770DEFHEADING() 2771 2772DEFHEADING(Network options:) 2773 2774DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2775#ifdef CONFIG_SLIRP 2776 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n" 2777 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2778 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2779 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2780 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2781#ifndef _WIN32 2782 "[,smb=dir[,smbserver=addr]]\n" 2783#endif 2784 " configure a user mode network backend with ID 'str',\n" 2785 " its DHCP server and optional services\n" 2786#endif 2787#ifdef _WIN32 2788 "-netdev tap,id=str,ifname=name\n" 2789 " configure a host TAP network backend with ID 'str'\n" 2790#else 2791 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2792 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2793 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2794 " [,poll-us=n]\n" 2795 " configure a host TAP network backend with ID 'str'\n" 2796 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2797 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2798 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2799 " to deconfigure it\n" 2800 " use '[down]script=no' to disable script execution\n" 2801 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2802 " configure it\n" 2803 " use 'fd=h' to connect to an already opened TAP interface\n" 2804 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2805 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2806 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2807 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2808 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2809 " use vhost=on to enable experimental in kernel accelerator\n" 2810 " (only has effect for virtio guests which use MSIX)\n" 2811 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2812 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2813 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2814 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2815 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n" 2816 " spent on busy polling for vhost net\n" 2817 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2818 " configure a host TAP network backend with ID 'str' that is\n" 2819 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2820 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2821#endif 2822#ifdef __linux__ 2823 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2824 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n" 2825 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n" 2826 " [,rxcookie=rxcookie][,offset=offset]\n" 2827 " configure a network backend with ID 'str' connected to\n" 2828 " an Ethernet over L2TPv3 pseudowire.\n" 2829 " Linux kernel 3.3+ as well as most routers can talk\n" 2830 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2831 " VM to a router and even VM to Host. It is a nearly-universal\n" 2832 " standard (RFC3931). Note - this implementation uses static\n" 2833 " pre-configured tunnels (same as the Linux kernel).\n" 2834 " use 'src=' to specify source address\n" 2835 " use 'dst=' to specify destination address\n" 2836 " use 'udp=on' to specify udp encapsulation\n" 2837 " use 'srcport=' to specify source udp port\n" 2838 " use 'dstport=' to specify destination udp port\n" 2839 " use 'ipv6=on' to force v6\n" 2840 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2841 " well as a weak security measure\n" 2842 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2843 " use 'txcookie=0x012345678' to specify a txcookie\n" 2844 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2845 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2846 " use 'pincounter=on' to work around broken counter handling in peer\n" 2847 " use 'offset=X' to add an extra offset between header and data\n" 2848#endif 2849 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2850 " configure a network backend to connect to another network\n" 2851 " using a socket connection\n" 2852 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2853 " configure a network backend to connect to a multicast maddr and port\n" 2854 " use 'localaddr=addr' to specify the host address to send packets from\n" 2855 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2856 " configure a network backend to connect to another network\n" 2857 " using an UDP tunnel\n" 2858 "-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" 2859 "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect=seconds]\n" 2860 "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect=seconds]\n" 2861 " configure a network backend to connect to another network\n" 2862 " using a socket connection in stream mode.\n" 2863 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n" 2864 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]\n" 2865 " configure a network backend to connect to a multicast maddr and port\n" 2866 " use ``local.host=addr`` to specify the host address to send packets from\n" 2867 "-netdev dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]\n" 2868 "-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]\n" 2869 "-netdev dgram,id=str,local.type=fd,local.str=file-descriptor\n" 2870 " configure a network backend to connect to another network\n" 2871 " using an UDP tunnel\n" 2872#ifdef CONFIG_VDE 2873 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2874 " configure a network backend to connect to port 'n' of a vde switch\n" 2875 " running on host and listening for incoming connections on 'socketpath'.\n" 2876 " Use group 'groupname' and mode 'octalmode' to change default\n" 2877 " ownership and permissions for communication port.\n" 2878#endif 2879#ifdef CONFIG_NETMAP 2880 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2881 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2882 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2883 " netmap device, defaults to '/dev/netmap')\n" 2884#endif 2885#ifdef CONFIG_AF_XDP 2886 "-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off]\n" 2887 " [,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]\n" 2888 " attach to the existing network interface 'name' with AF_XDP socket\n" 2889 " use 'mode=MODE' to specify an XDP program attach mode\n" 2890 " use 'force-copy=on|off' to force XDP copy mode even if device supports zero-copy (default: off)\n" 2891 " use 'inhibit=on|off' to inhibit loading of a default XDP program (default: off)\n" 2892 " with inhibit=on,\n" 2893 " use 'sock-fds' to provide file descriptors for already open AF_XDP sockets\n" 2894 " added to a socket map in XDP program. One socket per queue.\n" 2895 " use 'queues=n' to specify how many queues of a multiqueue interface should be used\n" 2896 " use 'start-queue=m' to specify the first queue that should be used\n" 2897#endif 2898#ifdef CONFIG_POSIX 2899 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2900 " configure a vhost-user network, backed by a chardev 'dev'\n" 2901#endif 2902#ifdef __linux__ 2903 "-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n" 2904 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n" 2905 " use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n" 2906 " use 'vhostfd=h' to connect to an already opened vhost vdpa device\n" 2907#endif 2908#ifdef CONFIG_VMNET 2909 "-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n" 2910 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2911 " configure a vmnet network backend in host mode with ID 'str',\n" 2912 " isolate this interface from others with 'isolated',\n" 2913 " configure the address range and choose a subnet mask,\n" 2914 " specify network UUID 'uuid' to disable DHCP and interact with\n" 2915 " vmnet-host interfaces within this isolated network\n" 2916 "-netdev vmnet-shared,id=str[,isolated=on|off][,nat66-prefix=addr]\n" 2917 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2918 " configure a vmnet network backend in shared mode with ID 'str',\n" 2919 " configure the address range and choose a subnet mask,\n" 2920 " set IPv6 ULA prefix (of length 64) to use for internal network,\n" 2921 " isolate this interface from others with 'isolated'\n" 2922 "-netdev vmnet-bridged,id=str,ifname=name[,isolated=on|off]\n" 2923 " configure a vmnet network backend in bridged mode with ID 'str',\n" 2924 " use 'ifname=name' to select a physical network interface to be bridged,\n" 2925 " isolate this interface from others with 'isolated'\n" 2926#endif 2927 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2928 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2929DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2930 "-nic [tap|bridge|" 2931#ifdef CONFIG_SLIRP 2932 "user|" 2933#endif 2934#ifdef __linux__ 2935 "l2tpv3|" 2936#endif 2937#ifdef CONFIG_VDE 2938 "vde|" 2939#endif 2940#ifdef CONFIG_NETMAP 2941 "netmap|" 2942#endif 2943#ifdef CONFIG_AF_XDP 2944 "af-xdp|" 2945#endif 2946#ifdef CONFIG_POSIX 2947 "vhost-user|" 2948#endif 2949#ifdef CONFIG_VMNET 2950 "vmnet-host|vmnet-shared|vmnet-bridged|" 2951#endif 2952 "socket][,option][,...][mac=macaddr]\n" 2953 " initialize an on-board / default host NIC (using MAC address\n" 2954 " macaddr) and connect it to the given host network backend\n" 2955 "-nic none use it alone to have zero network devices (the default is to\n" 2956 " provided a 'user' network connection)\n", 2957 QEMU_ARCH_ALL) 2958DEF("net", HAS_ARG, QEMU_OPTION_net, 2959 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2960 " configure or create an on-board (or machine default) NIC and\n" 2961 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2962 "-net [" 2963#ifdef CONFIG_SLIRP 2964 "user|" 2965#endif 2966 "tap|" 2967 "bridge|" 2968#ifdef CONFIG_VDE 2969 "vde|" 2970#endif 2971#ifdef CONFIG_NETMAP 2972 "netmap|" 2973#endif 2974#ifdef CONFIG_AF_XDP 2975 "af-xdp|" 2976#endif 2977#ifdef CONFIG_VMNET 2978 "vmnet-host|vmnet-shared|vmnet-bridged|" 2979#endif 2980 "socket][,option][,option][,...]\n" 2981 " old way to initialize a host network interface\n" 2982 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2983SRST 2984``-nic [tap|bridge|user|l2tpv3|vde|netmap|af-xdp|vhost-user|socket][,...][,mac=macaddr][,model=mn]`` 2985 This option is a shortcut for configuring both the on-board 2986 (default) guest NIC hardware and the host network backend in one go. 2987 The host backend options are the same as with the corresponding 2988 ``-netdev`` options below. The guest NIC model can be set with 2989 ``model=modelname``. Use ``model=help`` to list the available device 2990 types. The hardware MAC address can be set with ``mac=macaddr``. 2991 2992 The following two example do exactly the same, to show how ``-nic`` 2993 can be used to shorten the command line length: 2994 2995 .. parsed-literal:: 2996 2997 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2998 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2999 3000``-nic none`` 3001 Indicate that no network devices should be configured. It is used to 3002 override the default configuration (default NIC with "user" host 3003 network backend) which is activated if no other networking options 3004 are provided. 3005 3006``-netdev user,id=id[,option][,option][,...]`` 3007 Configure user mode host network backend which requires no 3008 administrator privilege to run. Valid options are: 3009 3010 ``id=id`` 3011 Assign symbolic name for use in monitor commands. 3012 3013 ``ipv4=on|off and ipv6=on|off`` 3014 Specify that either IPv4 or IPv6 must be enabled. If neither is 3015 specified both protocols are enabled. 3016 3017 ``net=addr[/mask]`` 3018 Set IP network address the guest will see. Optionally specify 3019 the netmask, either in the form a.b.c.d or as number of valid 3020 top-most bits. Default is 10.0.2.0/24. 3021 3022 ``host=addr`` 3023 Specify the guest-visible address of the host. Default is the 3024 2nd IP in the guest network, i.e. x.x.x.2. 3025 3026 ``ipv6-net=addr[/int]`` 3027 Set IPv6 network address the guest will see (default is 3028 fec0::/64). The network prefix is given in the usual hexadecimal 3029 IPv6 address notation. The prefix size is optional, and is given 3030 as the number of valid top-most bits (default is 64). 3031 3032 ``ipv6-host=addr`` 3033 Specify the guest-visible IPv6 address of the host. Default is 3034 the 2nd IPv6 in the guest network, i.e. xxxx::2. 3035 3036 ``restrict=on|off`` 3037 If this option is enabled, the guest will be isolated, i.e. it 3038 will not be able to contact the host and no guest IP packets 3039 will be routed over the host to the outside. This option does 3040 not affect any explicitly set forwarding rules. 3041 3042 ``hostname=name`` 3043 Specifies the client hostname reported by the built-in DHCP 3044 server. 3045 3046 ``dhcpstart=addr`` 3047 Specify the first of the 16 IPs the built-in DHCP server can 3048 assign. Default is the 15th to 31st IP in the guest network, 3049 i.e. x.x.x.15 to x.x.x.31. 3050 3051 ``dns=addr`` 3052 Specify the guest-visible address of the virtual nameserver. The 3053 address must be different from the host address. Default is the 3054 3rd IP in the guest network, i.e. x.x.x.3. 3055 3056 ``ipv6-dns=addr`` 3057 Specify the guest-visible address of the IPv6 virtual 3058 nameserver. The address must be different from the host address. 3059 Default is the 3rd IP in the guest network, i.e. xxxx::3. 3060 3061 ``dnssearch=domain`` 3062 Provides an entry for the domain-search list sent by the 3063 built-in DHCP server. More than one domain suffix can be 3064 transmitted by specifying this option multiple times. If 3065 supported, this will cause the guest to automatically try to 3066 append the given domain suffix(es) in case a domain name can not 3067 be resolved. 3068 3069 Example: 3070 3071 .. parsed-literal:: 3072 3073 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 3074 3075 ``domainname=domain`` 3076 Specifies the client domain name reported by the built-in DHCP 3077 server. 3078 3079 ``tftp=dir`` 3080 When using the user mode network stack, activate a built-in TFTP 3081 server. The files in dir will be exposed as the root of a TFTP 3082 server. The TFTP client on the guest must be configured in 3083 binary mode (use the command ``bin`` of the Unix TFTP client). 3084 3085 ``tftp-server-name=name`` 3086 In BOOTP reply, broadcast name as the "TFTP server name" 3087 (RFC2132 option 66). This can be used to advise the guest to 3088 load boot files or configurations from a different server than 3089 the host address. 3090 3091 ``bootfile=file`` 3092 When using the user mode network stack, broadcast file as the 3093 BOOTP filename. In conjunction with ``tftp``, this can be used 3094 to network boot a guest from a local directory. 3095 3096 Example (using pxelinux): 3097 3098 .. parsed-literal:: 3099 3100 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\ 3101 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 3102 3103 ``smb=dir[,smbserver=addr]`` 3104 When using the user mode network stack, activate a built-in SMB 3105 server so that Windows OSes can access to the host files in 3106 ``dir`` transparently. The IP address of the SMB server can be 3107 set to addr. By default the 4th IP in the guest network is used, 3108 i.e. x.x.x.4. 3109 3110 In the guest Windows OS, the line: 3111 3112 :: 3113 3114 10.0.2.4 smbserver 3115 3116 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows 3117 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows 3118 NT/2000). 3119 3120 Then ``dir`` can be accessed in ``\\smbserver\qemu``. 3121 3122 Note that a SAMBA server must be installed on the host OS. 3123 3124 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport`` 3125 Redirect incoming TCP or UDP connections to the host port 3126 hostport to the guest IP address guestaddr on guest port 3127 guestport. If guestaddr is not specified, its value is x.x.x.15 3128 (default first address given by the built-in DHCP server). By 3129 specifying hostaddr, the rule can be bound to a specific host 3130 interface. If no connection type is set, TCP is used. This 3131 option can be given multiple times. 3132 3133 For example, to redirect host X11 connection from screen 1 to 3134 guest screen 0, use the following: 3135 3136 .. parsed-literal:: 3137 3138 # on the host 3139 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 3140 # this host xterm should open in the guest X11 server 3141 xterm -display :1 3142 3143 To redirect telnet connections from host port 5555 to telnet 3144 port on the guest, use the following: 3145 3146 .. parsed-literal:: 3147 3148 # on the host 3149 |qemu_system| -nic user,hostfwd=tcp::5555-:23 3150 telnet localhost 5555 3151 3152 Then when you use on the host ``telnet localhost 5555``, you 3153 connect to the guest telnet server. 3154 3155 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command`` 3156 Forward guest TCP connections to the IP address server on port 3157 port to the character device dev or to a program executed by 3158 cmd:command which gets spawned for each connection. This option 3159 can be given multiple times. 3160 3161 You can either use a chardev directly and have that one used 3162 throughout QEMU's lifetime, like in the following example: 3163 3164 .. parsed-literal:: 3165 3166 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 3167 # the guest accesses it 3168 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 3169 3170 Or you can execute a command on every TCP connection established 3171 by the guest, so that QEMU behaves similar to an inetd process 3172 for that virtual server: 3173 3174 .. parsed-literal:: 3175 3176 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 3177 # and connect the TCP stream to its stdin/stdout 3178 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 3179 3180``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` 3181 Configure a host TAP network backend with ID id. 3182 3183 Use the network script file to configure it and the network script 3184 dfile to deconfigure it. If name is not provided, the OS 3185 automatically provides one. The default network configure script is 3186 ``/etc/qemu-ifup`` and the default network deconfigure script is 3187 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to 3188 disable script execution. 3189 3190 If running QEMU as an unprivileged user, use the network helper 3191 to configure the TAP interface and attach it to the bridge. 3192 The default network helper executable is 3193 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3194 ``br0``. 3195 3196 ``fd``\ =h can be used to specify the handle of an already opened 3197 host TAP interface. 3198 3199 Examples: 3200 3201 .. parsed-literal:: 3202 3203 #launch a QEMU instance with the default network script 3204 |qemu_system| linux.img -nic tap 3205 3206 .. parsed-literal:: 3207 3208 #launch a QEMU instance with two NICs, each one connected 3209 #to a TAP device 3210 |qemu_system| linux.img \\ 3211 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\ 3212 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 3213 3214 .. parsed-literal:: 3215 3216 #launch a QEMU instance with the default network helper to 3217 #connect a TAP device to bridge br0 3218 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3219 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 3220 3221``-netdev bridge,id=id[,br=bridge][,helper=helper]`` 3222 Connect a host TAP network interface to a host bridge device. 3223 3224 Use the network helper helper to configure the TAP interface and 3225 attach it to the bridge. The default network helper executable is 3226 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3227 ``br0``. 3228 3229 Examples: 3230 3231 .. parsed-literal:: 3232 3233 #launch a QEMU instance with the default network helper to 3234 #connect a TAP device to bridge br0 3235 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 3236 3237 .. parsed-literal:: 3238 3239 #launch a QEMU instance with the default network helper to 3240 #connect a TAP device to bridge qemubr0 3241 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 3242 3243``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]`` 3244 This host network backend can be used to connect the guest's network 3245 to another QEMU virtual machine using a TCP socket connection. If 3246 ``listen`` is specified, QEMU waits for incoming connections on port 3247 (host is optional). ``connect`` is used to connect to another QEMU 3248 instance using the ``listen`` option. ``fd``\ =h specifies an 3249 already opened TCP socket. 3250 3251 Example: 3252 3253 .. parsed-literal:: 3254 3255 # launch a first QEMU instance 3256 |qemu_system| linux.img \\ 3257 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3258 -netdev socket,id=n1,listen=:1234 3259 # connect the network of this instance to the network of the first instance 3260 |qemu_system| linux.img \\ 3261 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3262 -netdev socket,id=n2,connect=127.0.0.1:1234 3263 3264``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]`` 3265 Configure a socket host network backend to share the guest's network 3266 traffic with another QEMU virtual machines using a UDP multicast 3267 socket, effectively making a bus for every QEMU with same multicast 3268 address maddr and port. NOTES: 3269 3270 1. Several QEMU can be running on different hosts and share same bus 3271 (assuming correct multicast setup for these hosts). 3272 3273 2. mcast support is compatible with User Mode Linux (argument 3274 ``ethN=mcast``), see http://user-mode-linux.sf.net. 3275 3276 3. Use ``fd=h`` to specify an already opened UDP multicast socket. 3277 3278 Example: 3279 3280 .. parsed-literal:: 3281 3282 # launch one QEMU instance 3283 |qemu_system| linux.img \\ 3284 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3285 -netdev socket,id=n1,mcast=230.0.0.1:1234 3286 # launch another QEMU instance on same "bus" 3287 |qemu_system| linux.img \\ 3288 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3289 -netdev socket,id=n2,mcast=230.0.0.1:1234 3290 # launch yet another QEMU instance on same "bus" 3291 |qemu_system| linux.img \\ 3292 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\ 3293 -netdev socket,id=n3,mcast=230.0.0.1:1234 3294 3295 Example (User Mode Linux compat.): 3296 3297 .. parsed-literal:: 3298 3299 # launch QEMU instance (note mcast address selected is UML's default) 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 3303 # launch UML 3304 /path/to/linux ubd0=/path/to/root_fs eth0=mcast 3305 3306 Example (send packets from host's 1.2.3.4): 3307 3308 .. parsed-literal:: 3309 3310 |qemu_system| linux.img \\ 3311 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3312 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 3313 3314``-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]`` 3315 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931) 3316 is a popular protocol to transport Ethernet (and other Layer 2) data 3317 frames between two systems. It is present in routers, firewalls and 3318 the Linux kernel (from version 3.3 onwards). 3319 3320 This transport allows a VM to communicate to another VM, router or 3321 firewall directly. 3322 3323 ``src=srcaddr`` 3324 source address (mandatory) 3325 3326 ``dst=dstaddr`` 3327 destination address (mandatory) 3328 3329 ``udp`` 3330 select udp encapsulation (default is ip). 3331 3332 ``srcport=srcport`` 3333 source udp port. 3334 3335 ``dstport=dstport`` 3336 destination udp port. 3337 3338 ``ipv6`` 3339 force v6, otherwise defaults to v4. 3340 3341 ``rxcookie=rxcookie``; \ ``txcookie=txcookie`` 3342 Cookies are a weak form of security in the l2tpv3 specification. 3343 Their function is mostly to prevent misconfiguration. By default 3344 they are 32 bit. 3345 3346 ``cookie64`` 3347 Set cookie size to 64 bit instead of the default 32 3348 3349 ``counter=off`` 3350 Force a 'cut-down' L2TPv3 with no counter as in 3351 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 3352 3353 ``pincounter=on`` 3354 Work around broken counter handling in peer. This may also help 3355 on networks which have packet reorder. 3356 3357 ``offset=offset`` 3358 Add an extra offset between header and data 3359 3360 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to 3361 the bridge br-lan on the remote Linux host 1.2.3.4: 3362 3363 .. parsed-literal:: 3364 3365 # Setup tunnel on linux host using raw ip as encapsulation 3366 # on 1.2.3.4 3367 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\ 3368 encap udp udp_sport 16384 udp_dport 16384 3369 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\ 3370 0xFFFFFFFF peer_session_id 0xFFFFFFFF 3371 ifconfig vmtunnel0 mtu 1500 3372 ifconfig vmtunnel0 up 3373 brctl addif br-lan vmtunnel0 3374 3375 3376 # on 4.3.2.1 3377 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 3378 3379 |qemu_system| linux.img -device e1000,netdev=n1 \\ 3380 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 3381 3382``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]`` 3383 Configure VDE backend to connect to PORT n of a vde switch running 3384 on host and listening for incoming connections on socketpath. Use 3385 GROUP groupname and MODE octalmode to change default ownership and 3386 permissions for communication port. This option is only available if 3387 QEMU has been compiled with vde support enabled. 3388 3389 Example: 3390 3391 .. parsed-literal:: 3392 3393 # launch vde switch 3394 vde_switch -F -sock /tmp/myswitch 3395 # launch QEMU instance 3396 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch 3397 3398``-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]`` 3399 Configure AF_XDP backend to connect to a network interface 'name' 3400 using AF_XDP socket. A specific program attach mode for a default 3401 XDP program can be forced with 'mode', defaults to best-effort, 3402 where the likely most performant mode will be in use. Number of queues 3403 'n' should generally match the number or queues in the interface, 3404 defaults to 1. Traffic arriving on non-configured device queues will 3405 not be delivered to the network backend. 3406 3407 .. parsed-literal:: 3408 3409 # set number of queues to 4 3410 ethtool -L eth0 combined 4 3411 # launch QEMU instance 3412 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3413 -netdev af-xdp,id=n1,ifname=eth0,queues=4 3414 3415 'start-queue' option can be specified if a particular range of queues 3416 [m, m + n] should be in use. For example, this is may be necessary in 3417 order to use certain NICs in native mode. Kernel allows the driver to 3418 create a separate set of XDP queues on top of regular ones, and only 3419 these queues can be used for AF_XDP sockets. NICs that work this way 3420 may also require an additional traffic redirection with ethtool to these 3421 special queues. 3422 3423 .. parsed-literal:: 3424 3425 # set number of queues to 1 3426 ethtool -L eth0 combined 1 3427 # redirect all the traffic to the second queue (id: 1) 3428 # note: drivers may require non-empty key/mask pair. 3429 ethtool -N eth0 flow-type ether \\ 3430 dst 00:00:00:00:00:00 m FF:FF:FF:FF:FF:FE action 1 3431 ethtool -N eth0 flow-type ether \\ 3432 dst 00:00:00:00:00:01 m FF:FF:FF:FF:FF:FE action 1 3433 # launch QEMU instance 3434 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3435 -netdev af-xdp,id=n1,ifname=eth0,queues=1,start-queue=1 3436 3437 XDP program can also be loaded externally. In this case 'inhibit' option 3438 should be set to 'on' and 'sock-fds' provided with file descriptors for 3439 already open but not bound XDP sockets already added to a socket map for 3440 corresponding queues. One socket per queue. 3441 3442 .. parsed-literal:: 3443 3444 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3445 -netdev af-xdp,id=n1,ifname=eth0,queues=3,inhibit=on,sock-fds=15:16:17 3446 3447``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` 3448 Establish a vhost-user netdev, backed by a chardev id. The chardev 3449 should be a unix domain socket backed one. The vhost-user uses a 3450 specifically defined protocol to pass vhost ioctl replacement 3451 messages to an application on the other end of the socket. On 3452 non-MSIX guests, the feature can be forced with vhostforce. Use 3453 'queues=n' to specify the number of queues to be created for 3454 multiqueue vhost-user. 3455 3456 Example: 3457 3458 :: 3459 3460 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 3461 -numa node,memdev=mem \ 3462 -chardev socket,id=chr0,path=/path/to/socket \ 3463 -netdev type=vhost-user,id=net0,chardev=chr0 \ 3464 -device virtio-net-pci,netdev=net0 3465 3466``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]`` 3467 Establish a vhost-vdpa netdev. 3468 3469 vDPA device is a device that uses a datapath which complies with 3470 the virtio specifications with a vendor specific control path. 3471 vDPA devices can be both physically located on the hardware or 3472 emulated by software. 3473 3474``-netdev hubport,id=id,hubid=hubid[,netdev=nd]`` 3475 Create a hub port on the emulated hub with ID hubid. 3476 3477 The hubport netdev lets you connect a NIC to a QEMU emulated hub 3478 instead of a single netdev. Alternatively, you can also connect the 3479 hubport to another netdev with ID nd by using the ``netdev=nd`` 3480 option. 3481 3482``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]`` 3483 Legacy option to configure or create an on-board (or machine 3484 default) Network Interface Card(NIC) and connect it either to the 3485 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd. 3486 If model is omitted, then the default NIC model associated with the 3487 machine type is used. Note that the default NIC model may change in 3488 future QEMU releases, so it is highly recommended to always specify 3489 a model. Optionally, the MAC address can be changed to mac, the 3490 device address set to addr (PCI cards only), and a name can be 3491 assigned for use in monitor commands. Optionally, for PCI cards, you 3492 can specify the number v of MSI-X vectors that the card should have; 3493 this option currently only affects virtio cards; set v = 0 to 3494 disable MSI-X. If no ``-net`` option is specified, a single NIC is 3495 created. QEMU can emulate several different models of network card. 3496 Use ``-net nic,model=help`` for a list of available devices for your 3497 target. 3498 3499``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]`` 3500 Configure a host network backend (with the options corresponding to 3501 the same ``-netdev`` option) and connect it to the emulated hub 0 3502 (the default hub). Use name to specify the name of the hub port. 3503ERST 3504 3505DEFHEADING() 3506 3507DEFHEADING(Character device options:) 3508 3509DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 3510 "-chardev help\n" 3511 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3512 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n" 3513 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" 3514 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 3515 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" 3516 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" 3517 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 3518 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n" 3519 " [,logfile=PATH][,logappend=on|off]\n" 3520 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3521 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 3522 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3523 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 3524 "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3525 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3526#ifdef _WIN32 3527 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3528 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3529#else 3530 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3531 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 3532#endif 3533#ifdef CONFIG_BRLAPI 3534 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3535#endif 3536#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 3537 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 3538 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3539#endif 3540#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 3541 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3542#endif 3543#if defined(CONFIG_SPICE) 3544 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3545 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3546#endif 3547 , QEMU_ARCH_ALL 3548) 3549 3550SRST 3551The general form of a character device option is: 3552 3553``-chardev backend,id=id[,mux=on|off][,options]`` 3554 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, 3555 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, 3556 ``pty``, ``stdio``, ``braille``, ``parallel``, 3557 ``spicevmc``, ``spiceport``. The specific backend will determine the 3558 applicable options. 3559 3560 Use ``-chardev help`` to print all available chardev backend types. 3561 3562 All devices must have an id, which can be any string up to 127 3563 characters long. It is used to uniquely identify this device in 3564 other command line directives. 3565 3566 A character device may be used in multiplexing mode by multiple 3567 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is 3568 a "1:N" device, and here the "1" end is your specified chardev 3569 backend, and the "N" end is the various parts of QEMU that can talk 3570 to a chardev. If you create a chardev with ``id=myid`` and 3571 ``mux=on``, QEMU will create a multiplexer with your specified ID, 3572 and you can then configure multiple front ends to use that chardev 3573 ID for their input/output. Up to four different front ends can be 3574 connected to a single multiplexed chardev. (Without multiplexing 3575 enabled, a chardev can only be used by a single front end.) For 3576 instance you could use this to allow a single stdio chardev to be 3577 used by two serial ports and the QEMU monitor: 3578 3579 :: 3580 3581 -chardev stdio,mux=on,id=char0 \ 3582 -mon chardev=char0,mode=readline \ 3583 -serial chardev:char0 \ 3584 -serial chardev:char0 3585 3586 You can have more than one multiplexer in a system configuration; 3587 for instance you could have a TCP port multiplexed between UART 0 3588 and UART 1, and stdio multiplexed between the QEMU monitor and a 3589 parallel port: 3590 3591 :: 3592 3593 -chardev stdio,mux=on,id=char0 \ 3594 -mon chardev=char0,mode=readline \ 3595 -parallel chardev:char0 \ 3596 -chardev tcp,...,mux=on,id=char1 \ 3597 -serial chardev:char1 \ 3598 -serial chardev:char1 3599 3600 When you're using a multiplexed character device, some escape 3601 sequences are interpreted in the input. See the chapter about 3602 :ref:`keys in the character backend multiplexer` in the 3603 System Emulation Users Guide for more details. 3604 3605 Note that some other command line options may implicitly create 3606 multiplexed character backends; for instance ``-serial mon:stdio`` 3607 creates a multiplexed stdio backend connected to the serial port and 3608 the QEMU monitor, and ``-nographic`` also multiplexes the console 3609 and the monitor to stdio. 3610 3611 There is currently no support for multiplexing in the other 3612 direction (where a single QEMU front end takes input and output from 3613 multiple chardevs). 3614 3615 Every backend supports the ``logfile`` option, which supplies the 3616 path to a file to record all data transmitted via the backend. The 3617 ``logappend`` option controls whether the log file will be truncated 3618 or appended to when opened. 3619 3620The available backends are: 3621 3622``-chardev null,id=id`` 3623 A void device. This device will not emit any data, and will drop any 3624 data it receives. The null backend does not take any options. 3625 3626``-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]`` 3627 Create a two-way stream socket, which can be either a TCP or a unix 3628 socket. A unix socket will be created if ``path`` is specified. 3629 Behaviour is undefined if TCP options are specified for a unix 3630 socket. 3631 3632 ``server=on|off`` specifies that the socket shall be a listening socket. 3633 3634 ``wait=on|off`` specifies that QEMU should not block waiting for a client 3635 to connect to a listening socket. 3636 3637 ``telnet=on|off`` specifies that traffic on the socket should interpret 3638 telnet escape sequences. 3639 3640 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for 3641 communication. 3642 3643 ``reconnect`` sets the timeout for reconnecting on non-server 3644 sockets when the remote end goes away. qemu will delay this many 3645 seconds and then attempt to reconnect. Zero disables reconnecting, 3646 and is the default. 3647 3648 ``tls-creds`` requests enablement of the TLS protocol for 3649 encryption, and specifies the id of the TLS credentials to use for 3650 the handshake. The credentials must be previously created with the 3651 ``-object tls-creds`` argument. 3652 3653 ``tls-auth`` provides the ID of the QAuthZ authorization object 3654 against which the client's x509 distinguished name will be 3655 validated. This object is only resolved at time of use, so can be 3656 deleted and recreated on the fly while the chardev server is active. 3657 If missing, it will default to denying access. 3658 3659 TCP and unix socket options are given below: 3660 3661 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]`` 3662 ``host`` for a listening socket specifies the local address to 3663 be bound. For a connecting socket species the remote host to 3664 connect to. ``host`` is optional for listening sockets. If not 3665 specified it defaults to ``0.0.0.0``. 3666 3667 ``port`` for a listening socket specifies the local port to be 3668 bound. For a connecting socket specifies the port on the remote 3669 host to connect to. ``port`` can be given as either a port 3670 number or a service name. ``port`` is required. 3671 3672 ``to`` is only relevant to listening sockets. If it is 3673 specified, and ``port`` cannot be bound, QEMU will attempt to 3674 bind to subsequent ports up to and including ``to`` until it 3675 succeeds. ``to`` must be specified as a port number. 3676 3677 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 3678 or IPv6 must be used. If neither is specified the socket may 3679 use either protocol. 3680 3681 ``nodelay=on|off`` disables the Nagle algorithm. 3682 3683 ``unix options: path=path[,abstract=on|off][,tight=on|off]`` 3684 ``path`` specifies the local path of the unix socket. ``path`` 3685 is required. 3686 ``abstract=on|off`` specifies the use of the abstract socket namespace, 3687 rather than the filesystem. Optional, defaults to false. 3688 ``tight=on|off`` sets the socket length of abstract sockets to their minimum, 3689 rather than the full sun_path length. Optional, defaults to true. 3690 3691``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4=on|off][,ipv6=on|off]`` 3692 Sends all traffic from the guest to a remote host over UDP. 3693 3694 ``host`` specifies the remote host to connect to. If not specified 3695 it defaults to ``localhost``. 3696 3697 ``port`` specifies the port on the remote host to connect to. 3698 ``port`` is required. 3699 3700 ``localaddr`` specifies the local address to bind to. If not 3701 specified it defaults to ``0.0.0.0``. 3702 3703 ``localport`` specifies the local port to bind to. If not specified 3704 any available local port will be used. 3705 3706 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used. 3707 If neither is specified the device may use either protocol. 3708 3709``-chardev msmouse,id=id`` 3710 Forward QEMU's emulated msmouse events to the guest. ``msmouse`` 3711 does not take any options. 3712 3713``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` 3714 Connect to a QEMU text console. ``vc`` may optionally be given a 3715 specific size. 3716 3717 ``width`` and ``height`` specify the width and height respectively 3718 of the console, in pixels. 3719 3720 ``cols`` and ``rows`` specify that the console be sized to fit a 3721 text console with the given dimensions. 3722 3723``-chardev ringbuf,id=id[,size=size]`` 3724 Create a ring buffer with fixed size ``size``. size must be a power 3725 of two and defaults to ``64K``. 3726 3727``-chardev file,id=id,path=path[,input-path=input-path]`` 3728 Log all traffic received from the guest to a file. 3729 3730 ``path`` specifies the path of the file to be opened. This file will 3731 be created if it does not already exist, and overwritten if it does. 3732 ``path`` is required. 3733 3734 If ``input-path`` is specified, this is the path of a second file 3735 which will be used for input. If ``input-path`` is not specified, 3736 no input will be available from the chardev. 3737 3738 Note that ``input-path`` is not supported on Windows hosts. 3739 3740``-chardev pipe,id=id,path=path`` 3741 Create a two-way connection to the guest. The behaviour differs 3742 slightly between Windows hosts and other hosts: 3743 3744 On Windows, a single duplex pipe will be created at 3745 ``\\.pipe\path``. 3746 3747 On other hosts, 2 pipes will be created called ``path.in`` and 3748 ``path.out``. Data written to ``path.in`` will be received by the 3749 guest. Data written by the guest can be read from ``path.out``. QEMU 3750 will not create these fifos, and requires them to be present. 3751 3752 ``path`` forms part of the pipe path as described above. ``path`` is 3753 required. 3754 3755``-chardev console,id=id`` 3756 Send traffic from the guest to QEMU's standard output. ``console`` 3757 does not take any options. 3758 3759 ``console`` is only available on Windows hosts. 3760 3761``-chardev serial,id=id,path=path`` 3762 Send traffic from the guest to a serial device on the host. 3763 3764 On Unix hosts serial will actually accept any tty device, not only 3765 serial lines. 3766 3767 ``path`` specifies the name of the serial device to open. 3768 3769``-chardev pty,id=id`` 3770 Create a new pseudo-terminal on the host and connect to it. ``pty`` 3771 does not take any options. 3772 3773 ``pty`` is not available on Windows hosts. 3774 3775``-chardev stdio,id=id[,signal=on|off]`` 3776 Connect to standard input and standard output of the QEMU process. 3777 3778 ``signal`` controls if signals are enabled on the terminal, that 3779 includes exiting QEMU with the key sequence Control-c. This option 3780 is enabled by default, use ``signal=off`` to disable it. 3781 3782``-chardev braille,id=id`` 3783 Connect to a local BrlAPI server. ``braille`` does not take any 3784 options. 3785 3786``-chardev parallel,id=id,path=path`` 3787 \ 3788 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD 3789 hosts. 3790 3791 Connect to a local parallel port. 3792 3793 ``path`` specifies the path to the parallel port device. ``path`` is 3794 required. 3795 3796``-chardev spicevmc,id=id,debug=debug,name=name`` 3797 ``spicevmc`` is only available when spice support is built in. 3798 3799 ``debug`` debug level for spicevmc 3800 3801 ``name`` name of spice channel to connect to 3802 3803 Connect to a spice virtual machine channel, such as vdiport. 3804 3805``-chardev spiceport,id=id,debug=debug,name=name`` 3806 ``spiceport`` is only available when spice support is built in. 3807 3808 ``debug`` debug level for spicevmc 3809 3810 ``name`` name of spice port to connect to 3811 3812 Connect to a spice port, allowing a Spice client to handle the 3813 traffic identified by a name (preferably a fqdn). 3814ERST 3815 3816DEFHEADING() 3817 3818#ifdef CONFIG_TPM 3819DEFHEADING(TPM device options:) 3820 3821DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3822 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3823 " use path to provide path to a character device; default is /dev/tpm0\n" 3824 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3825 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3826 "-tpmdev emulator,id=id,chardev=dev\n" 3827 " configure the TPM device using chardev backend\n", 3828 QEMU_ARCH_ALL) 3829SRST 3830The general form of a TPM device option is: 3831 3832``-tpmdev backend,id=id[,options]`` 3833 The specific backend type will determine the applicable options. The 3834 ``-tpmdev`` option creates the TPM backend and requires a 3835 ``-device`` option that specifies the TPM frontend interface model. 3836 3837 Use ``-tpmdev help`` to print all available TPM backend types. 3838 3839The available backends are: 3840 3841``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path`` 3842 (Linux-host only) Enable access to the host's TPM using the 3843 passthrough driver. 3844 3845 ``path`` specifies the path to the host's TPM device, i.e., on a 3846 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by 3847 default ``/dev/tpm0`` is used. 3848 3849 ``cancel-path`` specifies the path to the host TPM device's sysfs 3850 entry allowing for cancellation of an ongoing TPM command. 3851 ``cancel-path`` is optional and by default QEMU will search for the 3852 sysfs entry to use. 3853 3854 Some notes about using the host's TPM with the passthrough driver: 3855 3856 The TPM device accessed by the passthrough driver must not be used 3857 by any other application on the host. 3858 3859 Since the host's firmware (BIOS/UEFI) has already initialized the 3860 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize 3861 the TPM again and may therefore not show a TPM-specific menu that 3862 would otherwise allow the user to configure the TPM, e.g., allow the 3863 user to enable/disable or activate/deactivate the TPM. Further, if 3864 TPM ownership is released from within a VM then the host's TPM will 3865 get disabled and deactivated. To enable and activate the TPM again 3866 afterwards, the host has to be rebooted and the user is required to 3867 enter the firmware's menu to enable and activate the TPM. If the TPM 3868 is left disabled and/or deactivated most TPM commands will fail. 3869 3870 To create a passthrough TPM use the following two options: 3871 3872 :: 3873 3874 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3875 3876 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by 3877 ``tpmdev=tpm0`` in the device option. 3878 3879``-tpmdev emulator,id=id,chardev=dev`` 3880 (Linux-host only) Enable access to a TPM emulator using Unix domain 3881 socket based chardev backend. 3882 3883 ``chardev`` specifies the unique ID of a character device backend 3884 that provides connection to the software TPM server. 3885 3886 To create a TPM emulator backend device with chardev socket backend: 3887 3888 :: 3889 3890 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3891ERST 3892 3893DEFHEADING() 3894 3895#endif 3896 3897DEFHEADING(Boot Image or Kernel specific:) 3898SRST 3899There are broadly 4 ways you can boot a system with QEMU. 3900 3901 - specify a firmware and let it control finding a kernel 3902 - specify a firmware and pass a hint to the kernel to boot 3903 - direct kernel image boot 3904 - manually load files into the guest's address space 3905 3906The third method is useful for quickly testing kernels but as there is 3907no firmware to pass configuration information to the kernel the 3908hardware must either be probeable, the kernel built for the exact 3909configuration or passed some configuration data (e.g. a DTB blob) 3910which tells the kernel what drivers it needs. This exact details are 3911often hardware specific. 3912 3913The final method is the most generic way of loading images into the 3914guest address space and used mostly for ``bare metal`` type 3915development where the reset vectors of the processor are taken into 3916account. 3917 3918ERST 3919 3920SRST 3921 3922For x86 machines and some other architectures ``-bios`` will generally 3923do the right thing with whatever it is given. For other machines the 3924more strict ``-pflash`` option needs an image that is sized for the 3925flash device for the given machine type. 3926 3927Please see the :ref:`system-targets-ref` section of the manual for 3928more detailed documentation. 3929 3930ERST 3931 3932DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3933 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3934SRST 3935``-bios file`` 3936 Set the filename for the BIOS. 3937ERST 3938 3939DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 3940 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 3941SRST 3942``-pflash file`` 3943 Use file as a parallel flash image. 3944ERST 3945 3946SRST 3947 3948The kernel options were designed to work with Linux kernels although 3949other things (like hypervisors) can be packaged up as a kernel 3950executable image. The exact format of a executable image is usually 3951architecture specific. 3952 3953The way in which the kernel is started (what address it is loaded at, 3954what if any information is passed to it via CPU registers, the state 3955of the hardware when it is started, and so on) is also architecture 3956specific. Typically it follows the specification laid down by the 3957Linux kernel for how kernels for that architecture must be started. 3958 3959ERST 3960 3961DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3962 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3963SRST 3964``-kernel bzImage`` 3965 Use bzImage as kernel image. The kernel can be either a Linux kernel 3966 or in multiboot format. 3967ERST 3968 3969DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3970 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3971SRST 3972``-append cmdline`` 3973 Use cmdline as kernel command line 3974ERST 3975 3976DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3977 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3978SRST 3979``-initrd file`` 3980 Use file as initial ram disk. 3981 3982``-initrd "file1 arg=foo,file2"`` 3983 This syntax is only available with multiboot. 3984 3985 Use file1 and file2 as modules and pass arg=foo as parameter to the 3986 first module. 3987ERST 3988 3989DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3990 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3991SRST 3992``-dtb file`` 3993 Use file as a device tree binary (dtb) image and pass it to the 3994 kernel on boot. 3995ERST 3996 3997SRST 3998 3999Finally you can also manually load images directly into the address 4000space of the guest. This is most useful for developers who already 4001know the layout of their guest and take care to ensure something sane 4002will happen when the reset vector executes. 4003 4004The generic loader can be invoked by using the loader device: 4005 4006``-device loader,addr=<addr>,data=<data>,data-len=<data-len>[,data-be=<data-be>][,cpu-num=<cpu-num>]`` 4007 4008there is also the guest loader which operates in a similar way but 4009tweaks the DTB so a hypervisor loaded via ``-kernel`` can find where 4010the guest image is: 4011 4012``-device guest-loader,addr=<addr>[,kernel=<path>,[bootargs=<arguments>]][,initrd=<path>]`` 4013 4014ERST 4015 4016DEFHEADING() 4017 4018DEFHEADING(Debug/Expert options:) 4019 4020DEF("compat", HAS_ARG, QEMU_OPTION_compat, 4021 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n" 4022 " Policy for handling deprecated management interfaces\n" 4023 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n" 4024 " Policy for handling unstable management interfaces\n", 4025 QEMU_ARCH_ALL) 4026SRST 4027``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]`` 4028 Set policy for handling deprecated management interfaces (experimental): 4029 4030 ``deprecated-input=accept`` (default) 4031 Accept deprecated commands and arguments 4032 ``deprecated-input=reject`` 4033 Reject deprecated commands and arguments 4034 ``deprecated-input=crash`` 4035 Crash on deprecated commands and arguments 4036 ``deprecated-output=accept`` (default) 4037 Emit deprecated command results and events 4038 ``deprecated-output=hide`` 4039 Suppress deprecated command results and events 4040 4041 Limitation: covers only syntactic aspects of QMP. 4042 4043``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]`` 4044 Set policy for handling unstable management interfaces (experimental): 4045 4046 ``unstable-input=accept`` (default) 4047 Accept unstable commands and arguments 4048 ``unstable-input=reject`` 4049 Reject unstable commands and arguments 4050 ``unstable-input=crash`` 4051 Crash on unstable commands and arguments 4052 ``unstable-output=accept`` (default) 4053 Emit unstable command results and events 4054 ``unstable-output=hide`` 4055 Suppress unstable command results and events 4056 4057 Limitation: covers only syntactic aspects of QMP. 4058ERST 4059 4060DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 4061 "-fw_cfg [name=]<name>,file=<file>\n" 4062 " add named fw_cfg entry with contents from file\n" 4063 "-fw_cfg [name=]<name>,string=<str>\n" 4064 " add named fw_cfg entry with contents from string\n", 4065 QEMU_ARCH_ALL) 4066SRST 4067``-fw_cfg [name=]name,file=file`` 4068 Add named fw\_cfg entry with contents from file file. 4069 4070``-fw_cfg [name=]name,string=str`` 4071 Add named fw\_cfg entry with contents from string str. 4072 4073 The terminating NUL character of the contents of str will not be 4074 included as part of the fw\_cfg item data. To insert contents with 4075 embedded NUL characters, you have to use the file parameter. 4076 4077 The fw\_cfg entries are passed by QEMU through to the guest. 4078 4079 Example: 4080 4081 :: 4082 4083 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 4084 4085 creates an fw\_cfg entry named opt/com.mycompany/blob with contents 4086 from ./my\_blob.bin. 4087ERST 4088 4089DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 4090 "-serial dev redirect the serial port to char device 'dev'\n", 4091 QEMU_ARCH_ALL) 4092SRST 4093``-serial dev`` 4094 Redirect the virtual serial port to host character device dev. The 4095 default device is ``vc`` in graphical mode and ``stdio`` in non 4096 graphical mode. 4097 4098 This option can be used several times to simulate up to 4 serial 4099 ports. 4100 4101 Use ``-serial none`` to disable all serial ports. 4102 4103 Available character devices are: 4104 4105 ``vc[:WxH]`` 4106 Virtual console. Optionally, a width and height can be given in 4107 pixel with 4108 4109 :: 4110 4111 vc:800x600 4112 4113 It is also possible to specify width or height in characters: 4114 4115 :: 4116 4117 vc:80Cx24C 4118 4119 ``pty`` 4120 [Linux only] Pseudo TTY (a new PTY is automatically allocated) 4121 4122 ``none`` 4123 No device is allocated. 4124 4125 ``null`` 4126 void device 4127 4128 ``chardev:id`` 4129 Use a named character device defined with the ``-chardev`` 4130 option. 4131 4132 ``/dev/XXX`` 4133 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial 4134 port parameters are set according to the emulated ones. 4135 4136 ``/dev/parportN`` 4137 [Linux only, parallel port only] Use host parallel port N. 4138 Currently SPP and EPP parallel port features can be used. 4139 4140 ``file:filename`` 4141 Write output to filename. No character can be read. 4142 4143 ``stdio`` 4144 [Unix only] standard input/output 4145 4146 ``pipe:filename`` 4147 name pipe filename 4148 4149 ``COMn`` 4150 [Windows only] Use host serial port n 4151 4152 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]`` 4153 This implements UDP Net Console. When remote\_host or src\_ip 4154 are not specified they default to ``0.0.0.0``. When not using a 4155 specified src\_port a random port is automatically chosen. 4156 4157 If you just want a simple readonly console you can use 4158 ``netcat`` or ``nc``, by starting QEMU with: 4159 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time 4160 QEMU writes something to that port it will appear in the 4161 netconsole session. 4162 4163 If you plan to send characters back via netconsole or you want 4164 to stop and start QEMU a lot of times, you should have QEMU use 4165 the same source port each time by using something like ``-serial 4166 udp::4555@:4556`` to QEMU. Another approach is to use a patched 4167 version of netcat which can listen to a TCP port and send and 4168 receive characters via udp. If you have a patched version of 4169 netcat which activates telnet remote echo and single char 4170 transfer, then you can use the following options to set up a 4171 netcat redirector to allow telnet on port 5555 to access the 4172 QEMU port. 4173 4174 ``QEMU Options:`` 4175 -serial udp::4555@:4556 4176 4177 ``netcat options:`` 4178 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 4179 4180 ``telnet options:`` 4181 localhost 5555 4182 4183 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]`` 4184 The TCP Net Console has two modes of operation. It can send the 4185 serial I/O to a location or wait for a connection from a 4186 location. By default the TCP Net Console is sent to host at the 4187 port. If you use the ``server=on`` option QEMU will wait for a client 4188 socket application to connect to the port before continuing, 4189 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off`` 4190 option disables the Nagle buffering algorithm. The ``reconnect=on`` 4191 option only applies if ``server=no`` is set, if the connection goes 4192 down it will attempt to reconnect at the given interval. If host 4193 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a 4194 time is accepted. You can use ``telnet=on`` to connect to the 4195 corresponding character device. 4196 4197 ``Example to send tcp console to 192.168.0.2 port 4444`` 4198 -serial tcp:192.168.0.2:4444 4199 4200 ``Example to listen and wait on port 4444 for connection`` 4201 -serial tcp::4444,server=on 4202 4203 ``Example to not wait and listen on ip 192.168.0.100 port 4444`` 4204 -serial tcp:192.168.0.100:4444,server=on,wait=off 4205 4206 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]`` 4207 The telnet protocol is used instead of raw tcp sockets. The 4208 options work the same as if you had specified ``-serial tcp``. 4209 The difference is that the port acts like a telnet server or 4210 client using telnet option negotiation. This will also allow you 4211 to send the MAGIC\_SYSRQ sequence if you use a telnet that 4212 supports sending the break sequence. Typically in unix telnet 4213 you do it with Control-] and then type "send break" followed by 4214 pressing the enter key. 4215 4216 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]`` 4217 The WebSocket protocol is used instead of raw tcp socket. The 4218 port acts as a WebSocket server. Client mode is not supported. 4219 4220 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]`` 4221 A unix domain socket is used instead of a tcp socket. The option 4222 works the same as if you had specified ``-serial tcp`` except 4223 the unix domain socket path is used for connections. 4224 4225 ``mon:dev_string`` 4226 This is a special option to allow the monitor to be multiplexed 4227 onto another serial port. The monitor is accessed with key 4228 sequence of Control-a and then pressing c. dev\_string should be 4229 any one of the serial devices specified above. An example to 4230 multiplex the monitor onto a telnet server listening on port 4231 4444 would be: 4232 4233 ``-serial mon:telnet::4444,server=on,wait=off`` 4234 4235 When the monitor is multiplexed to stdio in this way, Ctrl+C 4236 will not terminate QEMU any more but will be passed to the guest 4237 instead. 4238 4239 ``braille`` 4240 Braille device. This will use BrlAPI to display the braille 4241 output on a real or fake device. 4242 4243 ``msmouse`` 4244 Three button serial mouse. Configure the guest to use Microsoft 4245 protocol. 4246ERST 4247 4248DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 4249 "-parallel dev redirect the parallel port to char device 'dev'\n", 4250 QEMU_ARCH_ALL) 4251SRST 4252``-parallel dev`` 4253 Redirect the virtual parallel port to host device dev (same devices 4254 as the serial port). On Linux hosts, ``/dev/parportN`` can be used 4255 to use hardware devices connected on the corresponding host parallel 4256 port. 4257 4258 This option can be used several times to simulate up to 3 parallel 4259 ports. 4260 4261 Use ``-parallel none`` to disable all parallel ports. 4262ERST 4263 4264DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 4265 "-monitor dev redirect the monitor to char device 'dev'\n", 4266 QEMU_ARCH_ALL) 4267SRST 4268``-monitor dev`` 4269 Redirect the monitor to host device dev (same devices as the serial 4270 port). The default device is ``vc`` in graphical mode and ``stdio`` 4271 in non graphical mode. Use ``-monitor none`` to disable the default 4272 monitor. 4273ERST 4274DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 4275 "-qmp dev like -monitor but opens in 'control' mode\n", 4276 QEMU_ARCH_ALL) 4277SRST 4278``-qmp dev`` 4279 Like ``-monitor`` but opens in 'control' mode. For example, to make 4280 QMP available on localhost port 4444:: 4281 4282 -qmp tcp:localhost:4444,server=on,wait=off 4283 4284 Not all options are configurable via this syntax; for maximum 4285 flexibility use the ``-mon`` option and an accompanying ``-chardev``. 4286 4287ERST 4288DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 4289 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 4290 QEMU_ARCH_ALL) 4291SRST 4292``-qmp-pretty dev`` 4293 Like ``-qmp`` but uses pretty JSON formatting. 4294ERST 4295 4296DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 4297 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 4298SRST 4299``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]`` 4300 Set up a monitor connected to the chardev ``name``. 4301 QEMU supports two monitors: the Human Monitor Protocol 4302 (HMP; for human interaction), and the QEMU Monitor Protocol 4303 (QMP; a JSON RPC-style protocol). 4304 The default is HMP; ``mode=control`` selects QMP instead. 4305 ``pretty`` is only valid when ``mode=control``, 4306 turning on JSON pretty printing to ease 4307 human reading and debugging. 4308 4309 For example:: 4310 4311 -chardev socket,id=mon1,host=localhost,port=4444,server=on,wait=off \ 4312 -mon chardev=mon1,mode=control,pretty=on 4313 4314 enables the QMP monitor on localhost port 4444 with pretty-printing. 4315ERST 4316 4317DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 4318 "-debugcon dev redirect the debug console to char device 'dev'\n", 4319 QEMU_ARCH_ALL) 4320SRST 4321``-debugcon dev`` 4322 Redirect the debug console to host device dev (same devices as the 4323 serial port). The debug console is an I/O port which is typically 4324 port 0xe9; writing to that I/O port sends output to this device. The 4325 default device is ``vc`` in graphical mode and ``stdio`` in non 4326 graphical mode. 4327ERST 4328 4329DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 4330 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 4331SRST 4332``-pidfile file`` 4333 Store the QEMU process PID in file. It is useful if you launch QEMU 4334 from a script. 4335ERST 4336 4337DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 4338 "-singlestep deprecated synonym for -accel tcg,one-insn-per-tb=on\n", QEMU_ARCH_ALL) 4339SRST 4340``-singlestep`` 4341 This is a deprecated synonym for the TCG accelerator property 4342 ``one-insn-per-tb``. 4343ERST 4344 4345DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 4346 "--preconfig pause QEMU before machine is initialized (experimental)\n", 4347 QEMU_ARCH_ALL) 4348SRST 4349``--preconfig`` 4350 Pause QEMU for interactive configuration before the machine is 4351 created, which allows querying and configuring properties that will 4352 affect machine initialization. Use QMP command 'x-exit-preconfig' to 4353 exit the preconfig state and move to the next state (i.e. run guest 4354 if -S isn't used or pause the second time if -S is used). This 4355 option is experimental. 4356ERST 4357 4358DEF("S", 0, QEMU_OPTION_S, \ 4359 "-S freeze CPU at startup (use 'c' to start execution)\n", 4360 QEMU_ARCH_ALL) 4361SRST 4362``-S`` 4363 Do not start CPU at startup (you must type 'c' in the monitor). 4364ERST 4365 4366DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 4367 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 4368 " run qemu with overcommit hints\n" 4369 " mem-lock=on|off controls memory lock support (default: off)\n" 4370 " cpu-pm=on|off controls cpu power management (default: off)\n", 4371 QEMU_ARCH_ALL) 4372SRST 4373``-overcommit mem-lock=on|off`` 4374 \ 4375``-overcommit cpu-pm=on|off`` 4376 Run qemu with hints about host resource overcommit. The default is 4377 to assume that host overcommits all resources. 4378 4379 Locking qemu and guest memory can be enabled via ``mem-lock=on`` 4380 (disabled by default). This works when host memory is not 4381 overcommitted and reduces the worst-case latency for guest. 4382 4383 Guest ability to manage power state of host cpus (increasing latency 4384 for other processes on the same host cpu, but decreasing latency for 4385 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This 4386 works best when host CPU is not overcommitted. When used, host 4387 estimates of CPU cycle and power utilization will be incorrect, not 4388 taking into account guest idle time. 4389ERST 4390 4391DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 4392 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n" 4393 " the guest without waiting for gdb to connect; use -S too\n" 4394 " if you want it to not start execution.)\n", 4395 QEMU_ARCH_ALL) 4396SRST 4397``-gdb dev`` 4398 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter 4399 in the System Emulation Users Guide). Note that this option does not pause QEMU 4400 execution -- if you want QEMU to not start the guest until you 4401 connect with gdb and issue a ``continue`` command, you will need to 4402 also pass the ``-S`` option to QEMU. 4403 4404 The most usual configuration is to listen on a local TCP socket:: 4405 4406 -gdb tcp::3117 4407 4408 but you can specify other backends; UDP, pseudo TTY, or even stdio 4409 are all reasonable use cases. For example, a stdio connection 4410 allows you to start QEMU from within gdb and establish the 4411 connection via a pipe: 4412 4413 .. parsed-literal:: 4414 4415 (gdb) target remote | exec |qemu_system| -gdb stdio ... 4416ERST 4417 4418DEF("s", 0, QEMU_OPTION_s, \ 4419 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 4420 QEMU_ARCH_ALL) 4421SRST 4422``-s`` 4423 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 4424 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide). 4425ERST 4426 4427DEF("d", HAS_ARG, QEMU_OPTION_d, \ 4428 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 4429 QEMU_ARCH_ALL) 4430SRST 4431``-d item1[,...]`` 4432 Enable logging of specified items. Use '-d help' for a list of log 4433 items. 4434ERST 4435 4436DEF("D", HAS_ARG, QEMU_OPTION_D, \ 4437 "-D logfile output log to logfile (default stderr)\n", 4438 QEMU_ARCH_ALL) 4439SRST 4440``-D logfile`` 4441 Output log in logfile instead of to stderr 4442ERST 4443 4444DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 4445 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 4446 QEMU_ARCH_ALL) 4447SRST 4448``-dfilter range1[,...]`` 4449 Filter debug output to that relevant to a range of target addresses. 4450 The filter spec can be either start+size, start-size or start..end 4451 where start end and size are the addresses and sizes required. For 4452 example: 4453 4454 :: 4455 4456 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 4457 4458 Will dump output for any code in the 0x1000 sized block starting at 4459 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and 4460 another 0x1000 sized block starting at 0xffffffc00005f000. 4461ERST 4462 4463DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 4464 "-seed number seed the pseudo-random number generator\n", 4465 QEMU_ARCH_ALL) 4466SRST 4467``-seed number`` 4468 Force the guest to use a deterministic pseudo-random number 4469 generator, seeded with number. This does not affect crypto routines 4470 within the host. 4471ERST 4472 4473DEF("L", HAS_ARG, QEMU_OPTION_L, \ 4474 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 4475 QEMU_ARCH_ALL) 4476SRST 4477``-L path`` 4478 Set the directory for the BIOS, VGA BIOS and keymaps. 4479 4480 To list all the data directories, use ``-L help``. 4481ERST 4482 4483DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 4484 "-enable-kvm enable KVM full virtualization support\n", 4485 QEMU_ARCH_ARM | QEMU_ARCH_I386 | QEMU_ARCH_MIPS | QEMU_ARCH_PPC | 4486 QEMU_ARCH_RISCV | QEMU_ARCH_S390X) 4487SRST 4488``-enable-kvm`` 4489 Enable KVM full virtualization support. This option is only 4490 available if KVM support is enabled when compiling. 4491ERST 4492 4493DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 4494 "-xen-domid id specify xen guest domain id\n", 4495 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4496DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 4497 "-xen-attach attach to existing xen domain\n" 4498 " libxl will use this when starting QEMU\n", 4499 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4500DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 4501 "-xen-domid-restrict restrict set of available xen operations\n" 4502 " to specified domain id. (Does not affect\n" 4503 " xenpv machine type).\n", 4504 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4505SRST 4506``-xen-domid id`` 4507 Specify xen guest domain id (XEN only). 4508 4509``-xen-attach`` 4510 Attach to existing xen domain. libxl will use this when starting 4511 QEMU (XEN only). Restrict set of available xen operations to 4512 specified domain id (XEN only). 4513ERST 4514 4515DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 4516 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 4517SRST 4518``-no-reboot`` 4519 Exit instead of rebooting. 4520ERST 4521 4522DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 4523 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 4524SRST 4525``-no-shutdown`` 4526 Don't exit QEMU on guest shutdown, but instead only stop the 4527 emulation. This allows for instance switching to monitor to commit 4528 changes to the disk image. 4529ERST 4530 4531DEF("action", HAS_ARG, QEMU_OPTION_action, 4532 "-action reboot=reset|shutdown\n" 4533 " action when guest reboots [default=reset]\n" 4534 "-action shutdown=poweroff|pause\n" 4535 " action when guest shuts down [default=poweroff]\n" 4536 "-action panic=pause|shutdown|exit-failure|none\n" 4537 " action when guest panics [default=shutdown]\n" 4538 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" 4539 " action when watchdog fires [default=reset]\n", 4540 QEMU_ARCH_ALL) 4541SRST 4542``-action event=action`` 4543 The action parameter serves to modify QEMU's default behavior when 4544 certain guest events occur. It provides a generic method for specifying the 4545 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown`` 4546 parameters. 4547 4548 Examples: 4549 4550 ``-action panic=none`` 4551 ``-action reboot=shutdown,shutdown=pause`` 4552 ``-device i6300esb -action watchdog=pause`` 4553 4554ERST 4555 4556DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 4557 "-loadvm [tag|id]\n" \ 4558 " start right away with a saved state (loadvm in monitor)\n", 4559 QEMU_ARCH_ALL) 4560SRST 4561``-loadvm file`` 4562 Start right away with a saved state (``loadvm`` in monitor) 4563ERST 4564 4565#ifndef _WIN32 4566DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 4567 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 4568#endif 4569SRST 4570``-daemonize`` 4571 Daemonize the QEMU process after initialization. QEMU will not 4572 detach from standard IO until it is ready to receive connections on 4573 any of its devices. This option is a useful way for external 4574 programs to launch QEMU without having to cope with initialization 4575 race conditions. 4576ERST 4577 4578DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 4579 "-option-rom rom load a file, rom, into the option ROM space\n", 4580 QEMU_ARCH_ALL) 4581SRST 4582``-option-rom file`` 4583 Load the contents of file as an option ROM. This option is useful to 4584 load things like EtherBoot. 4585ERST 4586 4587DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 4588 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 4589 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 4590 QEMU_ARCH_ALL) 4591 4592SRST 4593``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]`` 4594 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at 4595 the current UTC or local time, respectively. ``localtime`` is 4596 required for correct date in MS-DOS or Windows. To start at a 4597 specific point in time, provide datetime in the format 4598 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC. 4599 4600 By default the RTC is driven by the host system time. This allows 4601 using of the RTC as accurate reference clock inside the guest, 4602 specifically if the host time is smoothly following an accurate 4603 external reference clock, e.g. via NTP. If you want to isolate the 4604 guest time from the host, you can set ``clock`` to ``rt`` instead, 4605 which provides a host monotonic clock if host support it. To even 4606 prevent the RTC from progressing during suspension, you can set 4607 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is 4608 recommended especially in icount mode in order to preserve 4609 determinism; however, note that in icount mode the speed of the 4610 virtual clock is variable and can in general differ from the host 4611 clock. 4612 4613 Enable ``driftfix`` (i386 targets only) if you experience time drift 4614 problems, specifically with Windows' ACPI HAL. This option will try 4615 to figure out how many timer interrupts were not processed by the 4616 Windows guest and will re-inject them. 4617ERST 4618 4619DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 4620 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \ 4621 " enable virtual instruction counter with 2^N clock ticks per\n" \ 4622 " instruction, enable aligning the host and virtual clocks\n" \ 4623 " or disable real time cpu sleeping, and optionally enable\n" \ 4624 " record-and-replay mode\n", QEMU_ARCH_ALL) 4625SRST 4626``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]`` 4627 Enable virtual instruction counter. The virtual cpu will execute one 4628 instruction every 2^N ns of virtual time. If ``auto`` is specified 4629 then the virtual cpu speed will be automatically adjusted to keep 4630 virtual time within a few seconds of real time. 4631 4632 Note that while this option can give deterministic behavior, it does 4633 not provide cycle accurate emulation. Modern CPUs contain 4634 superscalar out of order cores with complex cache hierarchies. The 4635 number of instructions executed often has little or no correlation 4636 with actual performance. 4637 4638 When the virtual cpu is sleeping, the virtual time will advance at 4639 default speed unless ``sleep=on`` is specified. With 4640 ``sleep=on``, the virtual time will jump to the next timer 4641 deadline instantly whenever the virtual cpu goes to sleep mode and 4642 will not advance if no timer is enabled. This behavior gives 4643 deterministic execution times from the guest point of view. 4644 The default if icount is enabled is ``sleep=off``. 4645 ``sleep=on`` cannot be used together with either ``shift=auto`` 4646 or ``align=on``. 4647 4648 ``align=on`` will activate the delay algorithm which will try to 4649 synchronise the host clock and the virtual clock. The goal is to 4650 have a guest running at the real frequency imposed by the shift 4651 option. Whenever the guest clock is behind the host clock and if 4652 ``align=on`` is specified then we print a message to the user to 4653 inform about the delay. Currently this option does not work when 4654 ``shift`` is ``auto``. Note: The sync algorithm will work for those 4655 shift values for which the guest clock runs ahead of the host clock. 4656 Typically this happens when the shift value is high (how high 4657 depends on the host machine). The default if icount is enabled 4658 is ``align=off``. 4659 4660 When the ``rr`` option is specified deterministic record/replay is 4661 enabled. The ``rrfile=`` option must also be provided to 4662 specify the path to the replay log. In record mode data is written 4663 to this file, and in replay mode it is read back. 4664 If the ``rrsnapshot`` option is given then it specifies a VM snapshot 4665 name. In record mode, a new VM snapshot with the given name is created 4666 at the start of execution recording. In replay mode this option 4667 specifies the snapshot name used to load the initial VM state. 4668ERST 4669 4670DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 4671 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 4672 " action when watchdog fires [default=reset]\n", 4673 QEMU_ARCH_ALL) 4674SRST 4675``-watchdog-action action`` 4676 The action controls what QEMU will do when the watchdog timer 4677 expires. The default is ``reset`` (forcefully reset the guest). 4678 Other possible actions are: ``shutdown`` (attempt to gracefully 4679 shutdown the guest), ``poweroff`` (forcefully poweroff the guest), 4680 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the 4681 guest), ``debug`` (print a debug message and continue), or ``none`` 4682 (do nothing). 4683 4684 Note that the ``shutdown`` action requires that the guest responds 4685 to ACPI signals, which it may not be able to do in the sort of 4686 situations where the watchdog would have expired, and thus 4687 ``-watchdog-action shutdown`` is not recommended for production use. 4688 4689 Examples: 4690 4691 ``-device i6300esb -watchdog-action pause`` 4692 4693ERST 4694 4695DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 4696 "-echr chr set terminal escape character instead of ctrl-a\n", 4697 QEMU_ARCH_ALL) 4698SRST 4699``-echr numeric_ascii_value`` 4700 Change the escape character used for switching to the monitor when 4701 using monitor and serial sharing. The default is ``0x01`` when using 4702 the ``-nographic`` option. ``0x01`` is equal to pressing 4703 ``Control-a``. You can select a different character from the ascii 4704 control keys where 1 through 26 map to Control-a through Control-z. 4705 For instance you could use the either of the following to change the 4706 escape character to Control-t. 4707 4708 ``-echr 0x14``; \ ``-echr 20`` 4709 4710ERST 4711 4712DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4713 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \ 4714 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \ 4715 "-incoming unix:socketpath\n" \ 4716 " prepare for incoming migration, listen on\n" \ 4717 " specified protocol and socket address\n" \ 4718 "-incoming fd:fd\n" \ 4719 "-incoming exec:cmdline\n" \ 4720 " accept incoming migration on given file descriptor\n" \ 4721 " or from given external command\n" \ 4722 "-incoming defer\n" \ 4723 " wait for the URI to be specified via migrate_incoming\n", 4724 QEMU_ARCH_ALL) 4725SRST 4726``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]`` 4727 \ 4728``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]`` 4729 Prepare for incoming migration, listen on a given tcp port. 4730 4731``-incoming unix:socketpath`` 4732 Prepare for incoming migration, listen on a given unix socket. 4733 4734``-incoming fd:fd`` 4735 Accept incoming migration from a given filedescriptor. 4736 4737``-incoming exec:cmdline`` 4738 Accept incoming migration as an output from specified external 4739 command. 4740 4741``-incoming defer`` 4742 Wait for the URI to be specified via migrate\_incoming. The monitor 4743 can be used to change settings (such as migration parameters) prior 4744 to issuing the migrate\_incoming to allow the migration to begin. 4745ERST 4746 4747DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4748 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4749SRST 4750``-only-migratable`` 4751 Only allow migratable devices. Devices will not be allowed to enter 4752 an unmigratable state. 4753ERST 4754 4755DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4756 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4757SRST 4758``-nodefaults`` 4759 Don't create default devices. Normally, QEMU sets the default 4760 devices like serial port, parallel port, virtual console, monitor 4761 device, VGA adapter, floppy and CD-ROM drive and others. The 4762 ``-nodefaults`` option will disable all those default devices. 4763ERST 4764 4765#ifndef _WIN32 4766DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4767 "-chroot dir chroot to dir just before starting the VM (deprecated)\n", 4768 QEMU_ARCH_ALL) 4769#endif 4770SRST 4771``-chroot dir`` 4772 Deprecated, use '-run-with chroot=...' instead. 4773 Immediately before starting guest execution, chroot to the specified 4774 directory. Especially useful in combination with -runas. 4775ERST 4776 4777#ifndef _WIN32 4778DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4779 "-runas user change to user id user just before starting the VM\n" \ 4780 " user can be numeric uid:gid instead\n", 4781 QEMU_ARCH_ALL) 4782#endif 4783SRST 4784``-runas user`` 4785 Immediately before starting guest execution, drop root privileges, 4786 switching to the specified user. 4787ERST 4788 4789DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4790 "-prom-env variable=value\n" 4791 " set OpenBIOS nvram variables\n", 4792 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4793SRST 4794``-prom-env variable=value`` 4795 Set OpenBIOS nvram variable to given value (PPC, SPARC only). 4796 4797 :: 4798 4799 qemu-system-sparc -prom-env 'auto-boot?=false' \ 4800 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' 4801 4802 :: 4803 4804 qemu-system-ppc -prom-env 'auto-boot?=false' \ 4805 -prom-env 'boot-device=hd:2,\yaboot' \ 4806 -prom-env 'boot-args=conf=hd:2,\yaboot.conf' 4807ERST 4808DEF("semihosting", 0, QEMU_OPTION_semihosting, 4809 "-semihosting semihosting mode\n", 4810 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4811 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4812SRST 4813``-semihosting`` 4814 Enable :ref:`Semihosting` mode (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V only). 4815 4816 .. warning:: 4817 Note that this allows guest direct access to the host filesystem, so 4818 should only be used with a trusted guest OS. 4819 4820 See the -semihosting-config option documentation for further 4821 information about the facilities this enables. 4822ERST 4823DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4824 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]\n" \ 4825 " semihosting configuration\n", 4826QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4827QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4828SRST 4829``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]`` 4830 Enable and configure :ref:`Semihosting` (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V 4831 only). 4832 4833 .. warning:: 4834 Note that this allows guest direct access to the host filesystem, so 4835 should only be used with a trusted guest OS. 4836 4837 ``target=native|gdb|auto`` 4838 Defines where the semihosting calls will be addressed, to QEMU 4839 (``native``) or to GDB (``gdb``). The default is ``auto``, which 4840 means ``gdb`` during debug sessions and ``native`` otherwise. 4841 4842 ``chardev=str1`` 4843 Send the output to a chardev backend output for native or auto 4844 output when not in gdb 4845 4846 ``userspace=on|off`` 4847 Allows code running in guest userspace to access the semihosting 4848 interface. The default is that only privileged guest code can 4849 make semihosting calls. Note that setting ``userspace=on`` should 4850 only be used if all guest code is trusted (for example, in 4851 bare-metal test case code). 4852 4853 ``arg=str1,arg=str2,...`` 4854 Allows the user to pass input arguments, and can be used 4855 multiple times to build up a list. The old-style 4856 ``-kernel``/``-append`` method of passing a command line is 4857 still supported for backward compatibility. If both the 4858 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are 4859 specified, the former is passed to semihosting as it always 4860 takes precedence. 4861ERST 4862DEF("old-param", 0, QEMU_OPTION_old_param, 4863 "-old-param old param mode\n", QEMU_ARCH_ARM) 4864SRST 4865``-old-param`` 4866 Old param mode (ARM only). 4867ERST 4868 4869DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4870 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4871 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4872 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4873 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4874 " by the kernel, but typically no longer used by modern\n" \ 4875 " C library implementations.\n" \ 4876 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \ 4877 " to elevate privileges using set*uid|gid system calls.\n" \ 4878 " The value 'children' will deny set*uid|gid system calls for\n" \ 4879 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4880 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4881 " blocking *fork and execve\n" \ 4882 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4883 QEMU_ARCH_ALL) 4884SRST 4885``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]`` 4886 Enable Seccomp mode 2 system call filter. 'on' will enable syscall 4887 filtering and 'off' will disable it. The default is 'off'. 4888 4889 ``obsolete=string`` 4890 Enable Obsolete system calls 4891 4892 ``elevateprivileges=string`` 4893 Disable set\*uid\|gid system calls 4894 4895 ``spawn=string`` 4896 Disable \*fork and execve 4897 4898 ``resourcecontrol=string`` 4899 Disable process affinity and schedular priority 4900ERST 4901 4902DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4903 "-readconfig <file>\n" 4904 " read config file\n", QEMU_ARCH_ALL) 4905SRST 4906``-readconfig file`` 4907 Read device configuration from file. This approach is useful when 4908 you want to spawn QEMU process with many command line options but 4909 you don't want to exceed the command line character limit. 4910ERST 4911 4912DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4913 "-no-user-config\n" 4914 " do not load default user-provided config files at startup\n", 4915 QEMU_ARCH_ALL) 4916SRST 4917``-no-user-config`` 4918 The ``-no-user-config`` option makes QEMU not load any of the 4919 user-provided config files on sysconfdir. 4920ERST 4921 4922DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4923 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4924 " specify tracing options\n", 4925 QEMU_ARCH_ALL) 4926SRST 4927``-trace [[enable=]pattern][,events=file][,file=file]`` 4928 .. include:: ../qemu-option-trace.rst.inc 4929 4930ERST 4931DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4932 "-plugin [file=]<file>[,<argname>=<argvalue>]\n" 4933 " load a plugin\n", 4934 QEMU_ARCH_ALL) 4935SRST 4936``-plugin file=file[,argname=argvalue]`` 4937 Load a plugin. 4938 4939 ``file=file`` 4940 Load the given plugin from a shared library file. 4941 4942 ``argname=argvalue`` 4943 Argument passed to the plugin. (Can be given multiple times.) 4944ERST 4945 4946HXCOMM Internal use 4947DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4948DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4949 4950#ifdef __linux__ 4951DEF("async-teardown", 0, QEMU_OPTION_asyncteardown, 4952 "-async-teardown enable asynchronous teardown\n", 4953 QEMU_ARCH_ALL) 4954SRST 4955``-async-teardown`` 4956 This option is deprecated and should no longer be used. The new option 4957 ``-run-with async-teardown=on`` is a replacement. 4958ERST 4959#endif 4960#ifdef CONFIG_POSIX 4961DEF("run-with", HAS_ARG, QEMU_OPTION_run_with, 4962 "-run-with [async-teardown=on|off][,chroot=dir]\n" 4963 " Set miscellaneous QEMU process lifecycle options:\n" 4964 " async-teardown=on enables asynchronous teardown (Linux only)\n" 4965 " chroot=dir chroot to dir just before starting the VM\n", 4966 QEMU_ARCH_ALL) 4967SRST 4968``-run-with [async-teardown=on|off][,chroot=dir]`` 4969 Set QEMU process lifecycle options. 4970 4971 ``async-teardown=on`` enables asynchronous teardown. A new process called 4972 "cleanup/<QEMU_PID>" will be created at startup sharing the address 4973 space with the main QEMU process, using clone. It will wait for the 4974 main QEMU process to terminate completely, and then exit. This allows 4975 QEMU to terminate very quickly even if the guest was huge, leaving the 4976 teardown of the address space to the cleanup process. Since the cleanup 4977 process shares the same cgroups as the main QEMU process, accounting is 4978 performed correctly. This only works if the cleanup process is not 4979 forcefully killed with SIGKILL before the main QEMU process has 4980 terminated completely. 4981 4982 ``chroot=dir`` can be used for doing a chroot to the specified directory 4983 immediately before starting the guest execution. This is especially useful 4984 in combination with -runas. 4985ERST 4986#endif 4987 4988DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4989 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n" 4990 " control error message format\n" 4991 " timestamp=on enables timestamps (default: off)\n" 4992 " guest-name=on enables guest name prefix but only if\n" 4993 " -name guest option is set (default: off)\n", 4994 QEMU_ARCH_ALL) 4995SRST 4996``-msg [timestamp[=on|off]][,guest-name[=on|off]]`` 4997 Control error message format. 4998 4999 ``timestamp=on|off`` 5000 Prefix messages with a timestamp. Default is off. 5001 5002 ``guest-name=on|off`` 5003 Prefix messages with guest name but only if -name guest option is set 5004 otherwise the option is ignored. Default is off. 5005ERST 5006 5007DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 5008 "-dump-vmstate <file>\n" 5009 " Output vmstate information in JSON format to file.\n" 5010 " Use the scripts/vmstate-static-checker.py file to\n" 5011 " check for possible regressions in migration code\n" 5012 " by comparing two such vmstate dumps.\n", 5013 QEMU_ARCH_ALL) 5014SRST 5015``-dump-vmstate file`` 5016 Dump json-encoded vmstate information for current machine type to 5017 file in file 5018ERST 5019 5020DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 5021 "-enable-sync-profile\n" 5022 " enable synchronization profiling\n", 5023 QEMU_ARCH_ALL) 5024SRST 5025``-enable-sync-profile`` 5026 Enable synchronization profiling. 5027ERST 5028 5029#if defined(CONFIG_TCG) && defined(CONFIG_LINUX) 5030DEF("perfmap", 0, QEMU_OPTION_perfmap, 5031 "-perfmap generate a /tmp/perf-${pid}.map file for perf\n", 5032 QEMU_ARCH_ALL) 5033SRST 5034``-perfmap`` 5035 Generate a map file for Linux perf tools that will allow basic profiling 5036 information to be broken down into basic blocks. 5037ERST 5038 5039DEF("jitdump", 0, QEMU_OPTION_jitdump, 5040 "-jitdump generate a jit-${pid}.dump file for perf\n", 5041 QEMU_ARCH_ALL) 5042SRST 5043``-jitdump`` 5044 Generate a dump file for Linux perf tools that maps basic blocks to symbol 5045 names, line numbers and JITted code. 5046ERST 5047#endif 5048 5049DEFHEADING() 5050 5051DEFHEADING(Generic object creation:) 5052 5053DEF("object", HAS_ARG, QEMU_OPTION_object, 5054 "-object TYPENAME[,PROP1=VALUE1,...]\n" 5055 " create a new object of type TYPENAME setting properties\n" 5056 " in the order they are specified. Note that the 'id'\n" 5057 " property must be set. These objects are placed in the\n" 5058 " '/objects' path.\n", 5059 QEMU_ARCH_ALL) 5060SRST 5061``-object typename[,prop1=value1,...]`` 5062 Create a new object of type typename setting properties in the order 5063 they are specified. Note that the 'id' property must be set. These 5064 objects are placed in the '/objects' path. 5065 5066 ``-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`` 5067 Creates a memory file backend object, which can be used to back 5068 the guest RAM with huge pages. 5069 5070 The ``id`` parameter is a unique ID that will be used to 5071 reference this memory region in other parameters, e.g. ``-numa``, 5072 ``-device nvdimm``, etc. 5073 5074 The ``size`` option provides the size of the memory region, and 5075 accepts common suffixes, e.g. ``500M``. 5076 5077 The ``mem-path`` provides the path to either a shared memory or 5078 huge page filesystem mount. 5079 5080 The ``share`` boolean option determines whether the memory 5081 region is marked as private to QEMU, or shared. The latter 5082 allows a co-operating external process to access the QEMU memory 5083 region. 5084 5085 The ``share`` is also required for pvrdma devices due to 5086 limitations in the RDMA API provided by Linux. 5087 5088 Setting share=on might affect the ability to configure NUMA 5089 bindings for the memory backend under some circumstances, see 5090 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel 5091 source tree for additional details. 5092 5093 Setting the ``discard-data`` boolean option to on indicates that 5094 file contents can be destroyed when QEMU exits, to avoid 5095 unnecessarily flushing data to the backing file. Note that 5096 ``discard-data`` is only an optimization, and QEMU might not 5097 discard file contents if it aborts unexpectedly or is terminated 5098 using SIGKILL. 5099 5100 The ``merge`` boolean option enables memory merge, also known as 5101 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider 5102 the pages for memory deduplication. 5103 5104 Setting the ``dump`` boolean option to off excludes the memory 5105 from core dumps. This feature is also known as MADV\_DONTDUMP. 5106 5107 The ``prealloc`` boolean option enables memory preallocation. 5108 5109 The ``host-nodes`` option binds the memory range to a list of 5110 NUMA host nodes. 5111 5112 The ``policy`` option sets the NUMA policy to one of the 5113 following values: 5114 5115 ``default`` 5116 default host policy 5117 5118 ``preferred`` 5119 prefer the given host node list for allocation 5120 5121 ``bind`` 5122 restrict memory allocation to the given host node list 5123 5124 ``interleave`` 5125 interleave memory allocations across the given host node 5126 list 5127 5128 The ``align`` option specifies the base address alignment when 5129 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg 5130 ``2M``. Some backend store specified by ``mem-path`` requires an 5131 alignment different than the default one used by QEMU, eg the 5132 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 5133 such cases, users can specify the required alignment via this 5134 option. 5135 5136 The ``offset`` option specifies the offset into the target file 5137 that the region starts at. You can use this parameter to back 5138 multiple regions with a single file. 5139 5140 The ``pmem`` option specifies whether the backing file specified 5141 by ``mem-path`` is in host persistent memory that can be 5142 accessed using the SNIA NVM programming model (e.g. Intel 5143 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary 5144 operations to guarantee the persistence of its own writes to 5145 ``mem-path`` (e.g. in vNVDIMM label emulation and live 5146 migration). Also, we will map the backend-file with MAP\_SYNC 5147 flag, which ensures the file metadata is in sync for 5148 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC 5149 requires support from both the host kernel (since Linux kernel 5150 4.15) and the filesystem of ``mem-path`` mounted with DAX 5151 option. 5152 5153 The ``readonly`` option specifies whether the backing file is opened 5154 read-only or read-write (default). 5155 5156 The ``rom`` option specifies whether to create Read Only Memory 5157 (ROM) that cannot be modified by the VM. Any write attempts to such 5158 ROM will be denied. Most use cases want proper RAM instead of ROM. 5159 However, selected use cases, like R/O NVDIMMs, can benefit from 5160 ROM. If set to ``on``, create ROM; if set to ``off``, create 5161 writable RAM; if set to ``auto`` (default), the value of the 5162 ``readonly`` option is used. This option is primarily helpful when 5163 we want to have writable RAM in configurations that would 5164 traditionally create ROM before the ``rom`` option was introduced: 5165 VM templating, where we want to open a file readonly 5166 (``readonly=on``) and mark the memory to be private for QEMU 5167 (``share=off``). For this use case, we need writable RAM instead 5168 of ROM, and want to also set ``rom=off``. 5169 5170 ``-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`` 5171 Creates a memory backend object, which can be used to back the 5172 guest RAM. Memory backend objects offer more control than the 5173 ``-m`` option that is traditionally used to define guest RAM. 5174 Please refer to ``memory-backend-file`` for a description of the 5175 options. 5176 5177 ``-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`` 5178 Creates an anonymous memory file backend object, which allows 5179 QEMU to share the memory with an external process (e.g. when 5180 using vhost-user). The memory is allocated with memfd and 5181 optional sealing. (Linux only) 5182 5183 The ``seal`` option creates a sealed-file, that will block 5184 further resizing the memory ('on' by default). 5185 5186 The ``hugetlb`` option specify the file to be created resides in 5187 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction 5188 with the ``hugetlb`` option, the ``hugetlbsize`` option specify 5189 the hugetlb page size on systems that support multiple hugetlb 5190 page sizes (it must be a power of 2 value supported by the 5191 system). 5192 5193 In some versions of Linux, the ``hugetlb`` option is 5194 incompatible with the ``seal`` option (requires at least Linux 5195 4.16). 5196 5197 Please refer to ``memory-backend-file`` for a description of the 5198 other options. 5199 5200 The ``share`` boolean option is on by default with memfd. 5201 5202 ``-object rng-builtin,id=id`` 5203 Creates a random number generator backend which obtains entropy 5204 from QEMU builtin functions. The ``id`` parameter is a unique ID 5205 that will be used to reference this entropy backend from the 5206 ``virtio-rng`` device. By default, the ``virtio-rng`` device 5207 uses this RNG backend. 5208 5209 ``-object rng-random,id=id,filename=/dev/random`` 5210 Creates a random number generator backend which obtains entropy 5211 from a device on the host. The ``id`` parameter is a unique ID 5212 that will be used to reference this entropy backend from the 5213 ``virtio-rng`` device. The ``filename`` parameter specifies 5214 which file to obtain entropy from and if omitted defaults to 5215 ``/dev/urandom``. 5216 5217 ``-object rng-egd,id=id,chardev=chardevid`` 5218 Creates a random number generator backend which obtains entropy 5219 from an external daemon running on the host. The ``id`` 5220 parameter is a unique ID that will be used to reference this 5221 entropy backend from the ``virtio-rng`` device. The ``chardev`` 5222 parameter is the unique ID of a character device backend that 5223 provides the connection to the RNG daemon. 5224 5225 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off`` 5226 Creates a TLS anonymous credentials object, which can be used to 5227 provide TLS support on network backends. The ``id`` parameter is 5228 a unique ID which network backends will use to access the 5229 credentials. The ``endpoint`` is either ``server`` or ``client`` 5230 depending on whether the QEMU network backend that uses the 5231 credentials will be acting as a client or as a server. If 5232 ``verify-peer`` is enabled (the default) then once the handshake 5233 is completed, the peer credentials will be verified, though this 5234 is a no-op for anonymous credentials. 5235 5236 The dir parameter tells QEMU where to find the credential files. 5237 For server endpoints, this directory may contain a file 5238 dh-params.pem providing diffie-hellman parameters to use for the 5239 TLS server. If the file is missing, QEMU will generate a set of 5240 DH parameters at startup. This is a computationally expensive 5241 operation that consumes random pool entropy, so it is 5242 recommended that a persistent set of parameters be generated 5243 upfront and saved. 5244 5245 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]`` 5246 Creates a TLS Pre-Shared Keys (PSK) credentials object, which 5247 can be used to provide TLS support on network backends. The 5248 ``id`` parameter is a unique ID which network backends will use 5249 to access the credentials. The ``endpoint`` is either ``server`` 5250 or ``client`` depending on whether the QEMU network backend that 5251 uses the credentials will be acting as a client or as a server. 5252 For clients only, ``username`` is the username which will be 5253 sent to the server. If omitted it defaults to "qemu". 5254 5255 The dir parameter tells QEMU where to find the keys file. It is 5256 called "dir/keys.psk" and contains "username:key" pairs. This 5257 file can most easily be created using the GnuTLS ``psktool`` 5258 program. 5259 5260 For server endpoints, dir may also contain a file dh-params.pem 5261 providing diffie-hellman parameters to use for the TLS server. 5262 If the file is missing, QEMU will generate a set of DH 5263 parameters at startup. This is a computationally expensive 5264 operation that consumes random pool entropy, so it is 5265 recommended that a persistent set of parameters be generated up 5266 front and saved. 5267 5268 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id`` 5269 Creates a TLS anonymous credentials object, which can be used to 5270 provide TLS support on network backends. The ``id`` parameter is 5271 a unique ID which network backends will use to access the 5272 credentials. The ``endpoint`` is either ``server`` or ``client`` 5273 depending on whether the QEMU network backend that uses the 5274 credentials will be acting as a client or as a server. If 5275 ``verify-peer`` is enabled (the default) then once the handshake 5276 is completed, the peer credentials will be verified. With x509 5277 certificates, this implies that the clients must be provided 5278 with valid client certificates too. 5279 5280 The dir parameter tells QEMU where to find the credential files. 5281 For server endpoints, this directory may contain a file 5282 dh-params.pem providing diffie-hellman parameters to use for the 5283 TLS server. If the file is missing, QEMU will generate a set of 5284 DH parameters at startup. This is a computationally expensive 5285 operation that consumes random pool entropy, so it is 5286 recommended that a persistent set of parameters be generated 5287 upfront and saved. 5288 5289 For x509 certificate credentials the directory will contain 5290 further files providing the x509 certificates. The certificates 5291 must be stored in PEM format, in filenames ca-cert.pem, 5292 ca-crl.pem (optional), server-cert.pem (only servers), 5293 server-key.pem (only servers), client-cert.pem (only clients), 5294 and client-key.pem (only clients). 5295 5296 For the server-key.pem and client-key.pem files which contain 5297 sensitive private keys, it is possible to use an encrypted 5298 version by providing the passwordid parameter. This provides the 5299 ID of a previously created ``secret`` object containing the 5300 password for decryption. 5301 5302 The priority parameter allows to override the global default 5303 priority used by gnutls. This can be useful if the system 5304 administrator needs to use a weaker set of crypto priorities for 5305 QEMU without potentially forcing the weakness onto all 5306 applications. Or conversely if one wants wants a stronger 5307 default for QEMU than for all other applications, they can do 5308 this through this parameter. Its format is a gnutls priority 5309 string as described at 5310 https://gnutls.org/manual/html_node/Priority-Strings.html. 5311 5312 ``-object tls-cipher-suites,id=id,priority=priority`` 5313 Creates a TLS cipher suites object, which can be used to control 5314 the TLS cipher/protocol algorithms that applications are permitted 5315 to use. 5316 5317 The ``id`` parameter is a unique ID which frontends will use to 5318 access the ordered list of permitted TLS cipher suites from the 5319 host. 5320 5321 The ``priority`` parameter allows to override the global default 5322 priority used by gnutls. This can be useful if the system 5323 administrator needs to use a weaker set of crypto priorities for 5324 QEMU without potentially forcing the weakness onto all 5325 applications. Or conversely if one wants wants a stronger 5326 default for QEMU than for all other applications, they can do 5327 this through this parameter. Its format is a gnutls priority 5328 string as described at 5329 https://gnutls.org/manual/html_node/Priority-Strings.html. 5330 5331 An example of use of this object is to control UEFI HTTPS Boot. 5332 The tls-cipher-suites object exposes the ordered list of permitted 5333 TLS cipher suites from the host side to the guest firmware, via 5334 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER 5335 objects. The firmware uses the IANA_TLS_CIPHER array for configuring 5336 guest-side TLS. 5337 5338 In the following example, the priority at which the host-side policy 5339 is retrieved is given by the ``priority`` property. 5340 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to 5341 refer to /etc/crypto-policies/back-ends/gnutls.config. 5342 5343 .. parsed-literal:: 5344 5345 # |qemu_system| \\ 5346 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\ 5347 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 5348 5349 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` 5350 Interval t can't be 0, this filter batches the packet delivery: 5351 all packets arriving in a given interval on netdev netdevid are 5352 delayed until the end of the interval. Interval is in 5353 microseconds. ``status`` is optional that indicate whether the 5354 netfilter is on (enabled) or off (disabled), the default status 5355 for netfilter will be 'on'. 5356 5357 queue all\|rx\|tx is an option that can be applied to any 5358 netfilter. 5359 5360 ``all``: the filter is attached both to the receive and the 5361 transmit queue of the netdev (default). 5362 5363 ``rx``: the filter is attached to the receive queue of the 5364 netdev, where it will receive packets sent to the netdev. 5365 5366 ``tx``: the filter is attached to the transmit queue of the 5367 netdev, where it will receive packets sent by the netdev. 5368 5369 position head\|tail\|id=<id> is an option to specify where the 5370 filter should be inserted in the filter list. It can be applied 5371 to any netfilter. 5372 5373 ``head``: the filter is inserted at the head of the filter list, 5374 before any existing filters. 5375 5376 ``tail``: the filter is inserted at the tail of the filter list, 5377 behind any existing filters (default). 5378 5379 ``id=<id>``: the filter is inserted before or behind the filter 5380 specified by <id>, see the insert option below. 5381 5382 insert behind\|before is an option to specify where to insert 5383 the new filter relative to the one specified with 5384 position=id=<id>. It can be applied to any netfilter. 5385 5386 ``before``: insert before the specified filter. 5387 5388 ``behind``: insert behind the specified filter (default). 5389 5390 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5391 filter-mirror on netdev netdevid,mirror net packet to 5392 chardevchardevid, if it has the vnet\_hdr\_support flag, 5393 filter-mirror will mirror packet with vnet\_hdr\_len. 5394 5395 ``-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]`` 5396 filter-redirector on netdev netdevid,redirect filter's net 5397 packet to chardev chardevid,and redirect indev's packet to 5398 filter.if it has the vnet\_hdr\_support flag, filter-redirector 5399 will redirect packet with vnet\_hdr\_len. Create a 5400 filter-redirector we need to differ outdev id from indev id, id 5401 can not be the same. we can just use indev or outdev, but at 5402 least one of indev or outdev need to be specified. 5403 5404 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5405 Filter-rewriter is a part of COLO project.It will rewrite tcp 5406 packet to secondary from primary to keep secondary tcp 5407 connection,and rewrite tcp packet to primary from secondary make 5408 tcp packet can be handled by client.if it has the 5409 vnet\_hdr\_support flag, we can parse packet with vnet header. 5410 5411 usage: colo secondary: -object 5412 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object 5413 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object 5414 filter-rewriter,id=rew0,netdev=hn0,queue=all 5415 5416 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]`` 5417 Dump the network traffic on netdev dev to the file specified by 5418 filename. At most len bytes (64k by default) per packet are 5419 stored. The file format is libpcap, so it can be analyzed with 5420 tools such as tcpdump or Wireshark. 5421 5422 ``-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}]`` 5423 Colo-compare gets packet from primary\_in chardevid and 5424 secondary\_in, then compare whether the payload of primary packet 5425 and secondary packet are the same. If same, it will output 5426 primary packet to out\_dev, else it will notify COLO-framework to do 5427 checkpoint and send primary packet to out\_dev. In order to 5428 improve efficiency, we need to put the task of comparison in 5429 another iothread. If it has the vnet\_hdr\_support flag, 5430 colo compare will send/recv packet with vnet\_hdr\_len. 5431 The compare\_timeout=@var{ms} determines the maximum time of the 5432 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms} 5433 is to set the period of scanning expired primary node network packets. 5434 The max\_queue\_size=@var{size} is to set the max compare queue 5435 size depend on user environment. 5436 If user want to use Xen COLO, need to add the notify\_dev to 5437 notify Xen colo-frame to do checkpoint. 5438 5439 COLO-compare must be used with the help of filter-mirror, 5440 filter-redirector and filter-rewriter. 5441 5442 :: 5443 5444 KVM COLO 5445 5446 primary: 5447 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5448 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5449 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5450 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5451 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5452 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5453 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5454 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5455 -object iothread,id=iothread1 5456 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5457 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5458 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5459 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 5460 5461 secondary: 5462 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5463 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5464 -chardev socket,id=red0,host=3.3.3.3,port=9003 5465 -chardev socket,id=red1,host=3.3.3.3,port=9004 5466 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5467 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5468 5469 5470 Xen COLO 5471 5472 primary: 5473 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5474 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5475 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5476 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5477 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5478 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5479 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5480 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5481 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off 5482 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5483 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5484 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5485 -object iothread,id=iothread1 5486 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 5487 5488 secondary: 5489 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5490 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5491 -chardev socket,id=red0,host=3.3.3.3,port=9003 5492 -chardev socket,id=red1,host=3.3.3.3,port=9004 5493 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5494 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5495 5496 If you want to know the detail of above command line, you can 5497 read the colo-compare git log. 5498 5499 ``-object cryptodev-backend-builtin,id=id[,queues=queues]`` 5500 Creates a cryptodev backend which executes crypto operations from 5501 the QEMU cipher APIs. The id parameter is a unique ID that will 5502 be used to reference this cryptodev backend from the 5503 ``virtio-crypto`` device. The queues parameter is optional, 5504 which specify the queue number of cryptodev backend, the default 5505 of queues is 1. 5506 5507 .. parsed-literal:: 5508 5509 # |qemu_system| \\ 5510 [...] \\ 5511 -object cryptodev-backend-builtin,id=cryptodev0 \\ 5512 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5513 [...] 5514 5515 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]`` 5516 Creates a vhost-user cryptodev backend, backed by a chardev 5517 chardevid. The id parameter is a unique ID that will be used to 5518 reference this cryptodev backend from the ``virtio-crypto`` 5519 device. The chardev should be a unix domain socket backed one. 5520 The vhost-user uses a specifically defined protocol to pass 5521 vhost ioctl replacement messages to an application on the other 5522 end of the socket. The queues parameter is optional, which 5523 specify the queue number of cryptodev backend for multiqueue 5524 vhost-user, the default of queues is 1. 5525 5526 .. parsed-literal:: 5527 5528 # |qemu_system| \\ 5529 [...] \\ 5530 -chardev socket,id=chardev0,path=/path/to/socket \\ 5531 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\ 5532 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5533 [...] 5534 5535 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]`` 5536 \ 5537 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]`` 5538 Defines a secret to store a password, encryption key, or some 5539 other sensitive data. The sensitive data can either be passed 5540 directly via the data parameter, or indirectly via the file 5541 parameter. Using the data parameter is insecure unless the 5542 sensitive data is encrypted. 5543 5544 The sensitive data can be provided in raw format (the default), 5545 or base64. When encoded as JSON, the raw format only supports 5546 valid UTF-8 characters, so base64 is recommended for sending 5547 binary data. QEMU will convert from which ever format is 5548 provided to the format it needs internally. eg, an RBD password 5549 can be provided in raw format, even though it will be base64 5550 encoded when passed onto the RBD sever. 5551 5552 For added protection, it is possible to encrypt the data 5553 associated with a secret using the AES-256-CBC cipher. Use of 5554 encryption is indicated by providing the keyid and iv 5555 parameters. The keyid parameter provides the ID of a previously 5556 defined secret that contains the AES-256 decryption key. This 5557 key should be 32-bytes long and be base64 encoded. The iv 5558 parameter provides the random initialization vector used for 5559 encryption of this particular secret and should be a base64 5560 encrypted string of the 16-byte IV. 5561 5562 The simplest (insecure) usage is to provide the secret inline 5563 5564 .. parsed-literal:: 5565 5566 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw 5567 5568 The simplest secure usage is to provide the secret via a file 5569 5570 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object 5571 secret,id=sec0,file=mypasswd.txt,format=raw 5572 5573 For greater security, AES-256-CBC should be used. To illustrate 5574 usage, consider the openssl command line tool which can encrypt 5575 the data. Note that when encrypting, the plaintext must be 5576 padded to the cipher block size (32 bytes) using the standard 5577 PKCS#5/6 compatible padding algorithm. 5578 5579 First a master key needs to be created in base64 encoding: 5580 5581 :: 5582 5583 # openssl rand -base64 32 > key.b64 5584 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 5585 5586 Each secret to be encrypted needs to have a random 5587 initialization vector generated. These do not need to be kept 5588 secret 5589 5590 :: 5591 5592 # openssl rand -base64 16 > iv.b64 5593 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 5594 5595 The secret to be defined can now be encrypted, in this case 5596 we're telling openssl to base64 encode the result, but it could 5597 be left as raw bytes if desired. 5598 5599 :: 5600 5601 # SECRET=$(printf "letmein" | 5602 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 5603 5604 When launching QEMU, create a master secret pointing to 5605 ``key.b64`` and specify that to be used to decrypt the user 5606 password. Pass the contents of ``iv.b64`` to the second secret 5607 5608 .. parsed-literal:: 5609 5610 # |qemu_system| \\ 5611 -object secret,id=secmaster0,format=base64,file=key.b64 \\ 5612 -object secret,id=sec0,keyid=secmaster0,format=base64,\\ 5613 data=$SECRET,iv=$(<iv.b64) 5614 5615 ``-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]`` 5616 Create a Secure Encrypted Virtualization (SEV) guest object, 5617 which can be used to provide the guest memory encryption support 5618 on AMD processors. 5619 5620 When memory encryption is enabled, one of the physical address 5621 bit (aka the C-bit) is utilized to mark if a memory page is 5622 protected. The ``cbitpos`` is used to provide the C-bit 5623 position. The C-bit position is Host family dependent hence user 5624 must provide this value. On EPYC, the value should be 47. 5625 5626 When memory encryption is enabled, we loose certain bits in 5627 physical address space. The ``reduced-phys-bits`` is used to 5628 provide the number of bits we loose in physical address space. 5629 Similar to C-bit, the value is Host family dependent. On EPYC, 5630 a guest will lose a maximum of 1 bit, so the value should be 1. 5631 5632 The ``sev-device`` provides the device file to use for 5633 communicating with the SEV firmware running inside AMD Secure 5634 Processor. The default device is '/dev/sev'. If hardware 5635 supports memory encryption then /dev/sev devices are created by 5636 CCP driver. 5637 5638 The ``policy`` provides the guest policy to be enforced by the 5639 SEV firmware and restrict what configuration and operational 5640 commands can be performed on this guest by the hypervisor. The 5641 policy should be provided by the guest owner and is bound to the 5642 guest and cannot be changed throughout the lifetime of the 5643 guest. The default is 0. 5644 5645 If guest ``policy`` allows sharing the key with another SEV 5646 guest then ``handle`` can be use to provide handle of the guest 5647 from which to share the key. 5648 5649 The ``dh-cert-file`` and ``session-file`` provides the guest 5650 owner's Public Diffie-Hillman key defined in SEV spec. The PDH 5651 and session parameters are used for establishing a cryptographic 5652 session with the guest owner to negotiate keys used for 5653 attestation. The file must be encoded in base64. 5654 5655 The ``kernel-hashes`` adds the hashes of given kernel/initrd/ 5656 cmdline to a designated guest firmware page for measured Linux 5657 boot with -kernel. The default is off. (Since 6.2) 5658 5659 e.g to launch a SEV guest 5660 5661 .. parsed-literal:: 5662 5663 # |qemu_system_x86| \\ 5664 ...... \\ 5665 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \\ 5666 -machine ...,memory-encryption=sev0 \\ 5667 ..... 5668 5669 ``-object authz-simple,id=id,identity=string`` 5670 Create an authorization object that will control access to 5671 network services. 5672 5673 The ``identity`` parameter is identifies the user and its format 5674 depends on the network service that authorization object is 5675 associated with. For authorizing based on TLS x509 certificates, 5676 the identity must be the x509 distinguished name. Note that care 5677 must be taken to escape any commas in the distinguished name. 5678 5679 An example authorization object to validate a x509 distinguished 5680 name would look like: 5681 5682 .. parsed-literal:: 5683 5684 # |qemu_system| \\ 5685 ... \\ 5686 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\ 5687 ... 5688 5689 Note the use of quotes due to the x509 distinguished name 5690 containing whitespace, and escaping of ','. 5691 5692 ``-object authz-listfile,id=id,filename=path,refresh=on|off`` 5693 Create an authorization object that will control access to 5694 network services. 5695 5696 The ``filename`` parameter is the fully qualified path to a file 5697 containing the access control list rules in JSON format. 5698 5699 An example set of rules that match against SASL usernames might 5700 look like: 5701 5702 :: 5703 5704 { 5705 "rules": [ 5706 { "match": "fred", "policy": "allow", "format": "exact" }, 5707 { "match": "bob", "policy": "allow", "format": "exact" }, 5708 { "match": "danb", "policy": "deny", "format": "glob" }, 5709 { "match": "dan*", "policy": "allow", "format": "exact" }, 5710 ], 5711 "policy": "deny" 5712 } 5713 5714 When checking access the object will iterate over all the rules 5715 and the first rule to match will have its ``policy`` value 5716 returned as the result. If no rules match, then the default 5717 ``policy`` value is returned. 5718 5719 The rules can either be an exact string match, or they can use 5720 the simple UNIX glob pattern matching to allow wildcards to be 5721 used. 5722 5723 If ``refresh`` is set to true the file will be monitored and 5724 automatically reloaded whenever its content changes. 5725 5726 As with the ``authz-simple`` object, the format of the identity 5727 strings being matched depends on the network service, but is 5728 usually a TLS x509 distinguished name, or a SASL username. 5729 5730 An example authorization object to validate a SASL username 5731 would look like: 5732 5733 .. parsed-literal:: 5734 5735 # |qemu_system| \\ 5736 ... \\ 5737 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\ 5738 ... 5739 5740 ``-object authz-pam,id=id,service=string`` 5741 Create an authorization object that will control access to 5742 network services. 5743 5744 The ``service`` parameter provides the name of a PAM service to 5745 use for authorization. It requires that a file 5746 ``/etc/pam.d/service`` exist to provide the configuration for 5747 the ``account`` subsystem. 5748 5749 An example authorization object to validate a TLS x509 5750 distinguished name would look like: 5751 5752 .. parsed-literal:: 5753 5754 # |qemu_system| \\ 5755 ... \\ 5756 -object authz-pam,id=auth0,service=qemu-vnc \\ 5757 ... 5758 5759 There would then be a corresponding config file for PAM at 5760 ``/etc/pam.d/qemu-vnc`` that contains: 5761 5762 :: 5763 5764 account requisite pam_listfile.so item=user sense=allow \ 5765 file=/etc/qemu/vnc.allow 5766 5767 Finally the ``/etc/qemu/vnc.allow`` file would contain the list 5768 of x509 distinguished names that are permitted access 5769 5770 :: 5771 5772 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 5773 5774 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch`` 5775 Creates a dedicated event loop thread that devices can be 5776 assigned to. This is known as an IOThread. By default device 5777 emulation happens in vCPU threads or the main event loop thread. 5778 This can become a scalability bottleneck. IOThreads allow device 5779 emulation and I/O to run on other host CPUs. 5780 5781 The ``id`` parameter is a unique ID that will be used to 5782 reference this IOThread from ``-device ...,iothread=id``. 5783 Multiple devices can be assigned to an IOThread. Note that not 5784 all devices support an ``iothread`` parameter. 5785 5786 The ``query-iothreads`` QMP command lists IOThreads and reports 5787 their thread IDs so that the user can configure host CPU 5788 pinning/affinity. 5789 5790 IOThreads use an adaptive polling algorithm to reduce event loop 5791 latency. Instead of entering a blocking system call to monitor 5792 file descriptors and then pay the cost of being woken up when an 5793 event occurs, the polling algorithm spins waiting for events for 5794 a short time. The algorithm's default parameters are suitable 5795 for many cases but can be adjusted based on knowledge of the 5796 workload and/or host device latency. 5797 5798 The ``poll-max-ns`` parameter is the maximum number of 5799 nanoseconds to busy wait for events. Polling can be disabled by 5800 setting this value to 0. 5801 5802 The ``poll-grow`` parameter is the multiplier used to increase 5803 the polling time when the algorithm detects it is missing events 5804 due to not polling long enough. 5805 5806 The ``poll-shrink`` parameter is the divisor used to decrease 5807 the polling time when the algorithm detects it is spending too 5808 long polling without encountering events. 5809 5810 The ``aio-max-batch`` parameter is the maximum number of requests 5811 in a batch for the AIO engine, 0 means that the engine will use 5812 its default. 5813 5814 The IOThread parameters can be modified at run-time using the 5815 ``qom-set`` command (where ``iothread1`` is the IOThread's 5816 ``id``): 5817 5818 :: 5819 5820 (qemu) qom-set /objects/iothread1 poll-max-ns 100000 5821ERST 5822 5823 5824HXCOMM This is the last statement. Insert new options before this line! 5825 5826#undef DEF 5827#undef DEFHEADING 5828#undef ARCHHEADING 5829
