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