1HXCOMM Use DEFHEADING() to define headings in both help text and rST. 2HXCOMM Text between SRST and ERST is copied to the rST version and 3HXCOMM discarded from C version. 4HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to 5HXCOMM construct option structures, enums and help message for specified 6HXCOMM architectures. 7HXCOMM HXCOMM can be used for comments, discarded from both rST and C. 8 9DEFHEADING(Standard options:) 10 11DEF("help", 0, QEMU_OPTION_h, 12 "-h or -help display this help and exit\n", QEMU_ARCH_ALL) 13SRST 14``-h`` 15 Display help and exit 16ERST 17 18DEF("version", 0, QEMU_OPTION_version, 19 "-version display version information and exit\n", QEMU_ARCH_ALL) 20SRST 21``-version`` 22 Display version information and exit 23ERST 24 25DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ 26 "-machine [type=]name[,prop[=value][,...]]\n" 27 " selects emulated machine ('-machine help' for list)\n" 28 " property accel=accel1[:accel2[:...]] selects accelerator\n" 29 " supported accelerators are kvm, xen, hvf, nvmm, whpx or tcg (default: tcg)\n" 30 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 31 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 32 " mem-merge=on|off controls memory merge support (default: on)\n" 33 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 34 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 35 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 36 " nvdimm=on|off controls NVDIMM support (default=off)\n" 37 " memory-encryption=@var{} memory encryption object to use (default=none)\n" 38 " hmat=on|off controls ACPI HMAT support (default=off)\n" 39 " memory-backend='backend-id' specifies explicitly provided backend for main RAM (default=none)\n" 40 " cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]\n", 41 QEMU_ARCH_ALL) 42SRST 43``-machine [type=]name[,prop=value[,...]]`` 44 Select the emulated machine by name. Use ``-machine help`` to list 45 available machines. 46 47 For architectures which aim to support live migration compatibility 48 across releases, each release will introduce a new versioned machine 49 type. For example, the 2.8.0 release introduced machine types 50 "pc-i440fx-2.8" and "pc-q35-2.8" for the x86\_64/i686 architectures. 51 52 To allow live migration of guests from QEMU version 2.8.0, to QEMU 53 version 2.9.0, the 2.9.0 version must support the "pc-i440fx-2.8" 54 and "pc-q35-2.8" machines too. To allow users live migrating VMs to 55 skip multiple intermediate releases when upgrading, new releases of 56 QEMU will support machine types from many previous versions. 57 58 Supported machine properties are: 59 60 ``accel=accels1[:accels2[:...]]`` 61 This is used to enable an accelerator. Depending on the target 62 architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available. 63 By default, tcg is used. If there is more than one accelerator 64 specified, the next one is used if the previous one fails to 65 initialize. 66 67 ``vmport=on|off|auto`` 68 Enables emulation of VMWare IO port, for vmmouse etc. auto says 69 to select the value based on accel. For accel=xen the default is 70 off otherwise the default is on. 71 72 ``dump-guest-core=on|off`` 73 Include guest memory in a core dump. The default is on. 74 75 ``mem-merge=on|off`` 76 Enables or disables memory merge support. This feature, when 77 supported by the host, de-duplicates identical memory pages 78 among VMs instances (enabled by default). 79 80 ``aes-key-wrap=on|off`` 81 Enables or disables AES key wrapping support on s390-ccw hosts. 82 This feature controls whether AES wrapping keys will be created 83 to allow execution of AES cryptographic functions. The default 84 is on. 85 86 ``dea-key-wrap=on|off`` 87 Enables or disables DEA key wrapping support on s390-ccw hosts. 88 This feature controls whether DEA wrapping keys will be created 89 to allow execution of DEA cryptographic functions. The default 90 is on. 91 92 ``nvdimm=on|off`` 93 Enables or disables NVDIMM support. The default is off. 94 95 ``memory-encryption=`` 96 Memory encryption object to use. The default is none. 97 98 ``hmat=on|off`` 99 Enables or disables ACPI Heterogeneous Memory Attribute Table 100 (HMAT) support. The default is off. 101 102 ``memory-backend='id'`` 103 An alternative to legacy ``-mem-path`` and ``mem-prealloc`` options. 104 Allows to use a memory backend as main RAM. 105 106 For example: 107 :: 108 109 -object memory-backend-file,id=pc.ram,size=512M,mem-path=/hugetlbfs,prealloc=on,share=on 110 -machine memory-backend=pc.ram 111 -m 512M 112 113 Migration compatibility note: 114 115 * as backend id one shall use value of 'default-ram-id', advertised by 116 machine type (available via ``query-machines`` QMP command), if migration 117 to/from old QEMU (<5.0) is expected. 118 * for machine types 4.0 and older, user shall 119 use ``x-use-canonical-path-for-ramblock-id=off`` backend option 120 if migration to/from old QEMU (<5.0) is expected. 121 122 For example: 123 :: 124 125 -object memory-backend-ram,id=pc.ram,size=512M,x-use-canonical-path-for-ramblock-id=off 126 -machine memory-backend=pc.ram 127 -m 512M 128 129 ``cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]`` 130 Define a CXL Fixed Memory Window (CFMW). 131 132 Described in the CXL 2.0 ECN: CEDT CFMWS & QTG _DSM. 133 134 They are regions of Host Physical Addresses (HPA) on a system which 135 may be interleaved across one or more CXL host bridges. The system 136 software will assign particular devices into these windows and 137 configure the downstream Host-managed Device Memory (HDM) decoders 138 in root ports, switch ports and devices appropriately to meet the 139 interleave requirements before enabling the memory devices. 140 141 ``targets.X=target`` provides the mapping to CXL host bridges 142 which may be identified by the id provided in the -device entry. 143 Multiple entries are needed to specify all the targets when 144 the fixed memory window represents interleaved memory. X is the 145 target index from 0. 146 147 ``size=size`` sets the size of the CFMW. This must be a multiple of 148 256MiB. The region will be aligned to 256MiB but the location is 149 platform and configuration dependent. 150 151 ``interleave-granularity=granularity`` sets the granularity of 152 interleave. Default 256KiB. Only 256KiB, 512KiB, 1024KiB, 2048KiB 153 4096KiB, 8192KiB and 16384KiB granularities supported. 154 155 Example: 156 157 :: 158 159 -machine cxl-fmw.0.targets.0=cxl.0,cxl-fmw.0.targets.1=cxl.1,cxl-fmw.0.size=128G,cxl-fmw.0.interleave-granularity=512k 160ERST 161 162DEF("M", HAS_ARG, QEMU_OPTION_M, 163 " sgx-epc.0.memdev=memid,sgx-epc.0.node=numaid\n", 164 QEMU_ARCH_ALL) 165 166SRST 167``sgx-epc.0.memdev=@var{memid},sgx-epc.0.node=@var{numaid}`` 168 Define an SGX EPC section. 169ERST 170 171DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 172 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 173SRST 174``-cpu model`` 175 Select CPU model (``-cpu help`` for list and additional feature 176 selection) 177ERST 178 179DEF("accel", HAS_ARG, QEMU_OPTION_accel, 180 "-accel [accel=]accelerator[,prop[=value][,...]]\n" 181 " select accelerator (kvm, xen, hvf, nvmm, whpx or tcg; use 'help' for a list)\n" 182 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n" 183 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n" 184 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n" 185 " one-insn-per-tb=on|off (one guest instruction per TCG translation block)\n" 186 " split-wx=on|off (enable TCG split w^x mapping)\n" 187 " tb-size=n (TCG translation block cache size)\n" 188 " dirty-ring-size=n (KVM dirty ring GFN count, default 0)\n" 189 " eager-split-size=n (KVM Eager Page Split chunk size, default 0, disabled. ARM only)\n" 190 " notify-vmexit=run|internal-error|disable,notify-window=n (enable notify VM exit and set notify window, x86 only)\n" 191 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 192SRST 193``-accel name[,prop=value[,...]]`` 194 This is used to enable an accelerator. Depending on the target 195 architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available. By 196 default, tcg is used. If there is more than one accelerator 197 specified, the next one is used if the previous one fails to 198 initialize. 199 200 ``igd-passthru=on|off`` 201 When Xen is in use, this option controls whether Intel 202 integrated graphics devices can be passed through to the guest 203 (default=off) 204 205 ``kernel-irqchip=on|off|split`` 206 Controls KVM in-kernel irqchip support. The default is full 207 acceleration of the interrupt controllers. On x86, split irqchip 208 reduces the kernel attack surface, at a performance cost for 209 non-MSI interrupts. Disabling the in-kernel irqchip completely 210 is not recommended except for debugging purposes. 211 212 ``kvm-shadow-mem=size`` 213 Defines the size of the KVM shadow MMU. 214 215 ``one-insn-per-tb=on|off`` 216 Makes the TCG accelerator put only one guest instruction into 217 each translation block. This slows down emulation a lot, but 218 can be useful in some situations, such as when trying to analyse 219 the logs produced by the ``-d`` option. 220 221 ``split-wx=on|off`` 222 Controls the use of split w^x mapping for the TCG code generation 223 buffer. Some operating systems require this to be enabled, and in 224 such a case this will default on. On other operating systems, this 225 will default off, but one may enable this for testing or debugging. 226 227 ``tb-size=n`` 228 Controls the size (in MiB) of the TCG translation block cache. 229 230 ``thread=single|multi`` 231 Controls number of TCG threads. When the TCG is multi-threaded 232 there will be one thread per vCPU therefore taking advantage of 233 additional host cores. The default is to enable multi-threading 234 where both the back-end and front-ends support it and no 235 incompatible TCG features have been enabled (e.g. 236 icount/replay). 237 238 ``dirty-ring-size=n`` 239 When the KVM accelerator is used, it controls the size of the per-vCPU 240 dirty page ring buffer (number of entries for each vCPU). It should 241 be a value that is power of two, and it should be 1024 or bigger (but 242 still less than the maximum value that the kernel supports). 4096 243 could be a good initial value if you have no idea which is the best. 244 Set this value to 0 to disable the feature. By default, this feature 245 is disabled (dirty-ring-size=0). When enabled, KVM will instead 246 record dirty pages in a bitmap. 247 248 ``eager-split-size=n`` 249 KVM implements dirty page logging at the PAGE_SIZE granularity and 250 enabling dirty-logging on a huge-page requires breaking it into 251 PAGE_SIZE pages in the first place. KVM on ARM does this splitting 252 lazily by default. There are performance benefits in doing huge-page 253 split eagerly, especially in situations where TLBI costs associated 254 with break-before-make sequences are considerable and also if guest 255 workloads are read intensive. The size here specifies how many pages 256 to break at a time and needs to be a valid block size which is 257 1GB/2MB/4KB, 32MB/16KB and 512MB/64KB for 4KB/16KB/64KB PAGE_SIZE 258 respectively. Be wary of specifying a higher size as it will have an 259 impact on the memory. By default, this feature is disabled 260 (eager-split-size=0). 261 262 ``notify-vmexit=run|internal-error|disable,notify-window=n`` 263 Enables or disables notify VM exit support on x86 host and specify 264 the corresponding notify window to trigger the VM exit if enabled. 265 ``run`` option enables the feature. It does nothing and continue 266 if the exit happens. ``internal-error`` option enables the feature. 267 It raises a internal error. ``disable`` option doesn't enable the feature. 268 This feature can mitigate the CPU stuck issue due to event windows don't 269 open up for a specified of time (i.e. notify-window). 270 Default: notify-vmexit=run,notify-window=0. 271 272ERST 273 274DEF("smp", HAS_ARG, QEMU_OPTION_smp, 275 "-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]\n" 276 " set the number of initial CPUs to 'n' [default=1]\n" 277 " maxcpus= maximum number of total CPUs, including\n" 278 " offline CPUs for hotplug, etc\n" 279 " sockets= number of sockets on the machine board\n" 280 " dies= number of dies in one socket\n" 281 " clusters= number of clusters in one die\n" 282 " cores= number of cores in one cluster\n" 283 " threads= number of threads in one core\n" 284 "Note: Different machines may have different subsets of the CPU topology\n" 285 " parameters supported, so the actual meaning of the supported parameters\n" 286 " will vary accordingly. For example, for a machine type that supports a\n" 287 " three-level CPU hierarchy of sockets/cores/threads, the parameters will\n" 288 " sequentially mean as below:\n" 289 " sockets means the number of sockets on the machine board\n" 290 " cores means the number of cores in one socket\n" 291 " threads means the number of threads in one core\n" 292 " For a particular machine type board, an expected CPU topology hierarchy\n" 293 " can be defined through the supported sub-option. Unsupported parameters\n" 294 " can also be provided in addition to the sub-option, but their values\n" 295 " must be set as 1 in the purpose of correct parsing.\n", 296 QEMU_ARCH_ALL) 297SRST 298``-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]`` 299 Simulate a SMP system with '\ ``n``\ ' CPUs initially present on 300 the machine type board. On boards supporting CPU hotplug, the optional 301 '\ ``maxcpus``\ ' parameter can be set to enable further CPUs to be 302 added at runtime. When both parameters are omitted, the maximum number 303 of CPUs will be calculated from the provided topology members and the 304 initial CPU count will match the maximum number. When only one of them 305 is given then the omitted one will be set to its counterpart's value. 306 Both parameters may be specified, but the maximum number of CPUs must 307 be equal to or greater than the initial CPU count. Product of the 308 CPU topology hierarchy must be equal to the maximum number of CPUs. 309 Both parameters are subject to an upper limit that is determined by 310 the specific machine type chosen. 311 312 To control reporting of CPU topology information, values of the topology 313 parameters can be specified. Machines may only support a subset of the 314 parameters and different machines may have different subsets supported 315 which vary depending on capacity of the corresponding CPU targets. So 316 for a particular machine type board, an expected topology hierarchy can 317 be defined through the supported sub-option. Unsupported parameters can 318 also be provided in addition to the sub-option, but their values must be 319 set as 1 in the purpose of correct parsing. 320 321 Either the initial CPU count, or at least one of the topology parameters 322 must be specified. The specified parameters must be greater than zero, 323 explicit configuration like "cpus=0" is not allowed. Values for any 324 omitted parameters will be computed from those which are given. 325 326 For example, the following sub-option defines a CPU topology hierarchy 327 (2 sockets totally on the machine, 2 cores per socket, 2 threads per 328 core) for a machine that only supports sockets/cores/threads. 329 Some members of the option can be omitted but their values will be 330 automatically computed: 331 332 :: 333 334 -smp 8,sockets=2,cores=2,threads=2,maxcpus=8 335 336 The following sub-option defines a CPU topology hierarchy (2 sockets 337 totally on the machine, 2 dies per socket, 2 cores per die, 2 threads 338 per core) for PC machines which support sockets/dies/cores/threads. 339 Some members of the option can be omitted but their values will be 340 automatically computed: 341 342 :: 343 344 -smp 16,sockets=2,dies=2,cores=2,threads=2,maxcpus=16 345 346 The following sub-option defines a CPU topology hierarchy (2 sockets 347 totally on the machine, 2 clusters per socket, 2 cores per cluster, 348 2 threads per core) for ARM virt machines which support sockets/clusters 349 /cores/threads. Some members of the option can be omitted but their values 350 will be automatically computed: 351 352 :: 353 354 -smp 16,sockets=2,clusters=2,cores=2,threads=2,maxcpus=16 355 356 Historically preference was given to the coarsest topology parameters 357 when computing missing values (ie sockets preferred over cores, which 358 were preferred over threads), however, this behaviour is considered 359 liable to change. Prior to 6.2 the preference was sockets over cores 360 over threads. Since 6.2 the preference is cores over sockets over threads. 361 362 For example, the following option defines a machine board with 2 sockets 363 of 1 core before 6.2 and 1 socket of 2 cores after 6.2: 364 365 :: 366 367 -smp 2 368 369 Note: The cluster topology will only be generated in ACPI and exposed 370 to guest if it's explicitly specified in -smp. 371ERST 372 373DEF("numa", HAS_ARG, QEMU_OPTION_numa, 374 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 375 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 376 "-numa dist,src=source,dst=destination,val=distance\n" 377 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n" 378 "-numa hmat-lb,initiator=node,target=node,hierarchy=memory|first-level|second-level|third-level,data-type=access-latency|read-latency|write-latency[,latency=lat][,bandwidth=bw]\n" 379 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n", 380 QEMU_ARCH_ALL) 381SRST 382``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 383 \ 384``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 385 \ 386``-numa dist,src=source,dst=destination,val=distance`` 387 \ 388``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]`` 389 \ 390``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=type[,latency=lat][,bandwidth=bw]`` 391 \ 392``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]`` 393 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA 394 distance from a source node to a destination node. Set the ACPI 395 Heterogeneous Memory Attributes for the given nodes. 396 397 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and 398 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a 399 contiguous range of CPU indexes (or a single VCPU if lastcpu is 400 omitted). A non-contiguous set of VCPUs can be represented by 401 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is 402 omitted on all nodes, VCPUs are automatically split between them. 403 404 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a 405 NUMA node: 406 407 :: 408 409 -numa node,cpus=0-2,cpus=5 410 411 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option 412 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to 413 assign CPU objects to a node using topology layout properties of 414 CPU. The set of properties is machine specific, and depends on used 415 machine type/'\ ``smp``\ ' options. It could be queried with 416 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ ' 417 property specifies node to which CPU object will be assigned, it's 418 required for node to be declared with '\ ``node``\ ' option before 419 it's used with '\ ``cpu``\ ' option. 420 421 For example: 422 423 :: 424 425 -M pc \ 426 -smp 1,sockets=2,maxcpus=2 \ 427 -numa node,nodeid=0 -numa node,nodeid=1 \ 428 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 429 430 '\ ``memdev``\ ' option assigns RAM from a given memory backend 431 device to a node. It is recommended to use '\ ``memdev``\ ' option 432 over legacy '\ ``mem``\ ' option. This is because '\ ``memdev``\ ' 433 option provides better performance and more control over the 434 backend's RAM (e.g. '\ ``prealloc``\ ' parameter of 435 '\ ``-memory-backend-ram``\ ' allows memory preallocation). 436 437 For compatibility reasons, legacy '\ ``mem``\ ' option is 438 supported in 5.0 and older machine types. Note that '\ ``mem``\ ' 439 and '\ ``memdev``\ ' are mutually exclusive. If one node uses 440 '\ ``memdev``\ ', the rest nodes have to use '\ ``memdev``\ ' 441 option, and vice versa. 442 443 Users must specify memory for all NUMA nodes by '\ ``memdev``\ ' 444 (or legacy '\ ``mem``\ ' if available). In QEMU 5.2, the support 445 for '\ ``-numa node``\ ' without memory specified was removed. 446 447 '\ ``initiator``\ ' is an additional option that points to an 448 initiator NUMA node that has best performance (the lowest latency or 449 largest bandwidth) to this NUMA node. Note that this option can be 450 set only when the machine property 'hmat' is set to 'on'. 451 452 Following example creates a machine with 2 NUMA nodes, node 0 has 453 CPU. node 1 has only memory, and its initiator is node 0. Note that 454 because node 0 has CPU, by default the initiator of node 0 is itself 455 and must be itself. 456 457 :: 458 459 -machine hmat=on \ 460 -m 2G,slots=2,maxmem=4G \ 461 -object memory-backend-ram,size=1G,id=m0 \ 462 -object memory-backend-ram,size=1G,id=m1 \ 463 -numa node,nodeid=0,memdev=m0 \ 464 -numa node,nodeid=1,memdev=m1,initiator=0 \ 465 -smp 2,sockets=2,maxcpus=2 \ 466 -numa cpu,node-id=0,socket-id=0 \ 467 -numa cpu,node-id=0,socket-id=1 468 469 source and destination are NUMA node IDs. distance is the NUMA 470 distance from source to destination. The distance from a node to 471 itself is always 10. If any pair of nodes is given a distance, then 472 all pairs must be given distances. Although, when distances are only 473 given in one direction for each pair of nodes, then the distances in 474 the opposite directions are assumed to be the same. If, however, an 475 asymmetrical pair of distances is given for even one node pair, then 476 all node pairs must be provided distance values for both directions, 477 even when they are symmetrical. When a node is unreachable from 478 another node, set the pair's distance to 255. 479 480 Note that the -``numa`` option doesn't allocate any of the specified 481 resources, it just assigns existing resources to NUMA nodes. This 482 means that one still has to use the ``-m``, ``-smp`` options to 483 allocate RAM and VCPUs respectively. 484 485 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth 486 Information between initiator and target NUMA nodes in ACPI 487 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can 488 create memory requests, usually it has one or more processors. 489 Target NUMA node contains addressable memory. 490 491 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is 492 the memory hierarchy of the target NUMA node: if hierarchy is 493 'memory', the structure represents the memory performance; if 494 hierarchy is 'first-level\|second-level\|third-level', this 495 structure represents aggregated performance of memory side caches 496 for each domain. type of 'data-type' is type of data represented by 497 this structure instance: if 'hierarchy' is 'memory', 'data-type' is 498 'access\|read\|write' latency or 'access\|read\|write' bandwidth of 499 the target memory; if 'hierarchy' is 500 'first-level\|second-level\|third-level', 'data-type' is 501 'access\|read\|write' hit latency or 'access\|read\|write' hit 502 bandwidth of the target memory side cache. 503 504 lat is latency value in nanoseconds. bw is bandwidth value, the 505 possible value and units are NUM[M\|G\|T], mean that the bandwidth 506 value are NUM byte per second (or MB/s, GB/s or TB/s depending on 507 used suffix). Note that if latency or bandwidth value is 0, means 508 the corresponding latency or bandwidth information is not provided. 509 510 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory 511 belongs. size is the size of memory side cache in bytes. level is 512 the cache level described in this structure, note that the cache 513 level 0 should not be used with '\ ``hmat-cache``\ ' option. 514 associativity is the cache associativity, the possible value is 515 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy 516 is the write policy. line is the cache Line size in bytes. 517 518 For example, the following options describe 2 NUMA nodes. Node 0 has 519 2 cpus and a ram, node 1 has only a ram. The processors in node 0 520 access memory in node 0 with access-latency 5 nanoseconds, 521 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access 522 memory in NUMA node 1 with access-latency 10 nanoseconds, 523 access-bandwidth is 100 MB/s. And for memory side cache information, 524 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB, 525 policy is write-back, the cache Line size is 8 bytes: 526 527 :: 528 529 -machine hmat=on \ 530 -m 2G \ 531 -object memory-backend-ram,size=1G,id=m0 \ 532 -object memory-backend-ram,size=1G,id=m1 \ 533 -smp 2,sockets=2,maxcpus=2 \ 534 -numa node,nodeid=0,memdev=m0 \ 535 -numa node,nodeid=1,memdev=m1,initiator=0 \ 536 -numa cpu,node-id=0,socket-id=0 \ 537 -numa cpu,node-id=0,socket-id=1 \ 538 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \ 539 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \ 540 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \ 541 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \ 542 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \ 543 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8 544ERST 545 546DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 547 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 548 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 549SRST 550``-add-fd fd=fd,set=set[,opaque=opaque]`` 551 Add a file descriptor to an fd set. Valid options are: 552 553 ``fd=fd`` 554 This option defines the file descriptor of which a duplicate is 555 added to fd set. The file descriptor cannot be stdin, stdout, or 556 stderr. 557 558 ``set=set`` 559 This option defines the ID of the fd set to add the file 560 descriptor to. 561 562 ``opaque=opaque`` 563 This option defines a free-form string that can be used to 564 describe fd. 565 566 You can open an image using pre-opened file descriptors from an fd 567 set: 568 569 .. parsed-literal:: 570 571 |qemu_system| \\ 572 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 573 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 574 -drive file=/dev/fdset/2,index=0,media=disk 575ERST 576 577DEF("set", HAS_ARG, QEMU_OPTION_set, 578 "-set group.id.arg=value\n" 579 " set <arg> parameter for item <id> of type <group>\n" 580 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 581SRST 582``-set group.id.arg=value`` 583 Set parameter arg for item id of type group 584ERST 585 586DEF("global", HAS_ARG, QEMU_OPTION_global, 587 "-global driver.property=value\n" 588 "-global driver=driver,property=property,value=value\n" 589 " set a global default for a driver property\n", 590 QEMU_ARCH_ALL) 591SRST 592``-global driver.prop=value`` 593 \ 594``-global driver=driver,property=property,value=value`` 595 Set default value of driver's property prop to value, e.g.: 596 597 .. parsed-literal:: 598 599 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img 600 601 In particular, you can use this to set driver properties for devices 602 which are created automatically by the machine model. To create a 603 device which is not created automatically and set properties on it, 604 use -``device``. 605 606 -global driver.prop=value is shorthand for -global 607 driver=driver,property=prop,value=value. The longhand syntax works 608 even when driver contains a dot. 609ERST 610 611DEF("boot", HAS_ARG, QEMU_OPTION_boot, 612 "-boot [order=drives][,once=drives][,menu=on|off]\n" 613 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 614 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 615 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 616 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 617 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 618 QEMU_ARCH_ALL) 619SRST 620``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]`` 621 Specify boot order drives as a string of drive letters. Valid drive 622 letters depend on the target architecture. The x86 PC uses: a, b 623 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p 624 (Etherboot from network adapter 1-4), hard disk boot is the default. 625 To apply a particular boot order only on the first startup, specify 626 it via ``once``. Note that the ``order`` or ``once`` parameter 627 should not be used together with the ``bootindex`` property of 628 devices, since the firmware implementations normally do not support 629 both at the same time. 630 631 Interactive boot menus/prompts can be enabled via ``menu=on`` as far 632 as firmware/BIOS supports them. The default is non-interactive boot. 633 634 A splash picture could be passed to bios, enabling user to show it 635 as logo, when option splash=sp\_name is given and menu=on, If 636 firmware/BIOS supports them. Currently Seabios for X86 system 637 support it. limitation: The splash file could be a jpeg file or a 638 BMP file in 24 BPP format(true color). The resolution should be 639 supported by the SVGA mode, so the recommended is 320x240, 640x480, 640 800x640. 641 642 A timeout could be passed to bios, guest will pause for rb\_timeout 643 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will 644 not reboot, qemu passes '-1' to bios by default. Currently Seabios 645 for X86 system support it. 646 647 Do strict boot via ``strict=on`` as far as firmware/BIOS supports 648 it. This only effects when boot priority is changed by bootindex 649 options. The default is non-strict boot. 650 651 .. parsed-literal:: 652 653 # try to boot from network first, then from hard disk 654 |qemu_system_x86| -boot order=nc 655 # boot from CD-ROM first, switch back to default order after reboot 656 |qemu_system_x86| -boot once=d 657 # boot with a splash picture for 5 seconds. 658 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000 659 660 Note: The legacy format '-boot drives' is still supported but its 661 use is discouraged as it may be removed from future versions. 662ERST 663 664DEF("m", HAS_ARG, QEMU_OPTION_m, 665 "-m [size=]megs[,slots=n,maxmem=size]\n" 666 " configure guest RAM\n" 667 " size: initial amount of guest memory\n" 668 " slots: number of hotplug slots (default: none)\n" 669 " maxmem: maximum amount of guest memory (default: none)\n" 670 " Note: Some architectures might enforce a specific granularity\n", 671 QEMU_ARCH_ALL) 672SRST 673``-m [size=]megs[,slots=n,maxmem=size]`` 674 Sets guest startup RAM size to megs megabytes. Default is 128 MiB. 675 Optionally, a suffix of "M" or "G" can be used to signify a value in 676 megabytes or gigabytes respectively. Optional pair slots, maxmem 677 could be used to set amount of hotpluggable memory slots and maximum 678 amount of memory. Note that maxmem must be aligned to the page size. 679 680 For example, the following command-line sets the guest startup RAM 681 size to 1GB, creates 3 slots to hotplug additional memory and sets 682 the maximum memory the guest can reach to 4GB: 683 684 .. parsed-literal:: 685 686 |qemu_system| -m 1G,slots=3,maxmem=4G 687 688 If slots and maxmem are not specified, memory hotplug won't be 689 enabled and the guest startup RAM will never increase. 690ERST 691 692DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 693 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 694SRST 695``-mem-path path`` 696 Allocate guest RAM from a temporarily created file in path. 697ERST 698 699DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 700 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 701 QEMU_ARCH_ALL) 702SRST 703``-mem-prealloc`` 704 Preallocate memory when using -mem-path. 705ERST 706 707DEF("k", HAS_ARG, QEMU_OPTION_k, 708 "-k language use keyboard layout (for example 'fr' for French)\n", 709 QEMU_ARCH_ALL) 710SRST 711``-k language`` 712 Use keyboard layout language (for example ``fr`` for French). This 713 option is only needed where it is not easy to get raw PC keycodes 714 (e.g. on Macs, with some X11 servers or with a VNC or curses 715 display). You don't normally need to use it on PC/Linux or 716 PC/Windows hosts. 717 718 The available layouts are: 719 720 :: 721 722 ar de-ch es fo fr-ca hu ja mk no pt-br sv 723 da en-gb et fr fr-ch is lt nl pl ru th 724 de en-us fi fr-be hr it lv nl-be pt sl tr 725 726 The default is ``en-us``. 727ERST 728 729 730HXCOMM Deprecated by -audiodev 731DEF("audio-help", 0, QEMU_OPTION_audio_help, 732 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 733 QEMU_ARCH_ALL) 734SRST 735``-audio-help`` 736 Will show the -audiodev equivalent of the currently specified 737 (deprecated) environment variables. 738ERST 739 740DEF("audio", HAS_ARG, QEMU_OPTION_audio, 741 "-audio [driver=]driver,model=value[,prop[=value][,...]]\n" 742 " specifies the audio backend and device to use;\n" 743 " apart from 'model', options are the same as for -audiodev.\n" 744 " use '-audio model=help' to show possible devices.\n", 745 QEMU_ARCH_ALL) 746SRST 747``-audio [driver=]driver,model=value[,prop[=value][,...]]`` 748 This option is a shortcut for configuring both the guest audio 749 hardware and the host audio backend in one go. 750 The driver option is the same as with the corresponding ``-audiodev`` option below. 751 The guest hardware model can be set with ``model=modelname``. 752 753 Use ``driver=help`` to list the available drivers, 754 and ``model=help`` to list the available device types. 755 756 The following two example do exactly the same, to show how ``-audio`` 757 can be used to shorten the command line length: 758 759 .. parsed-literal:: 760 761 |qemu_system| -audiodev pa,id=pa -device sb16,audiodev=pa 762 |qemu_system| -audio pa,model=sb16 763ERST 764 765DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 766 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 767 " specifies the audio backend to use\n" 768 " Use ``-audiodev help`` to list the available drivers\n" 769 " id= identifier of the backend\n" 770 " timer-period= timer period in microseconds\n" 771 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 772 " in|out.fixed-settings= use fixed settings for host audio\n" 773 " in|out.frequency= frequency to use with fixed settings\n" 774 " in|out.channels= number of channels to use with fixed settings\n" 775 " in|out.format= sample format to use with fixed settings\n" 776 " valid values: s8, s16, s32, u8, u16, u32, f32\n" 777 " in|out.voices= number of voices to use\n" 778 " in|out.buffer-length= length of buffer in microseconds\n" 779 "-audiodev none,id=id,[,prop[=value][,...]]\n" 780 " dummy driver that discards all output\n" 781#ifdef CONFIG_AUDIO_ALSA 782 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 783 " in|out.dev= name of the audio device to use\n" 784 " in|out.period-length= length of period in microseconds\n" 785 " in|out.try-poll= attempt to use poll mode\n" 786 " threshold= threshold (in microseconds) when playback starts\n" 787#endif 788#ifdef CONFIG_AUDIO_COREAUDIO 789 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 790 " in|out.buffer-count= number of buffers\n" 791#endif 792#ifdef CONFIG_AUDIO_DSOUND 793 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 794 " latency= add extra latency to playback in microseconds\n" 795#endif 796#ifdef CONFIG_AUDIO_OSS 797 "-audiodev oss,id=id[,prop[=value][,...]]\n" 798 " in|out.dev= path of the audio device to use\n" 799 " in|out.buffer-count= number of buffers\n" 800 " in|out.try-poll= attempt to use poll mode\n" 801 " try-mmap= try using memory mapped access\n" 802 " exclusive= open device in exclusive mode\n" 803 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 804#endif 805#ifdef CONFIG_AUDIO_PA 806 "-audiodev pa,id=id[,prop[=value][,...]]\n" 807 " server= PulseAudio server address\n" 808 " in|out.name= source/sink device name\n" 809 " in|out.latency= desired latency in microseconds\n" 810#endif 811#ifdef CONFIG_AUDIO_PIPEWIRE 812 "-audiodev pipewire,id=id[,prop[=value][,...]]\n" 813 " in|out.name= source/sink device name\n" 814 " in|out.stream-name= name of pipewire stream\n" 815 " in|out.latency= desired latency in microseconds\n" 816#endif 817#ifdef CONFIG_AUDIO_SDL 818 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 819 " in|out.buffer-count= number of buffers\n" 820#endif 821#ifdef CONFIG_AUDIO_SNDIO 822 "-audiodev sndio,id=id[,prop[=value][,...]]\n" 823#endif 824#ifdef CONFIG_SPICE 825 "-audiodev spice,id=id[,prop[=value][,...]]\n" 826#endif 827#ifdef CONFIG_DBUS_DISPLAY 828 "-audiodev dbus,id=id[,prop[=value][,...]]\n" 829#endif 830 "-audiodev wav,id=id[,prop[=value][,...]]\n" 831 " path= path of wav file to record\n", 832 QEMU_ARCH_ALL) 833SRST 834``-audiodev [driver=]driver,id=id[,prop[=value][,...]]`` 835 Adds a new audio backend driver identified by id. There are global 836 and driver specific properties. Some values can be set differently 837 for input and output, they're marked with ``in|out.``. You can set 838 the input's property with ``in.prop`` and the output's property with 839 ``out.prop``. For example: 840 841 :: 842 843 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 844 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 845 846 NOTE: parameter validation is known to be incomplete, in many cases 847 specifying an invalid option causes QEMU to print an error message 848 and continue emulation without sound. 849 850 Valid global options are: 851 852 ``id=identifier`` 853 Identifies the audio backend. 854 855 ``timer-period=period`` 856 Sets the timer period used by the audio subsystem in 857 microseconds. Default is 10000 (10 ms). 858 859 ``in|out.mixing-engine=on|off`` 860 Use QEMU's mixing engine to mix all streams inside QEMU and 861 convert audio formats when not supported by the backend. When 862 off, fixed-settings must be off too. Note that disabling this 863 option means that the selected backend must support multiple 864 streams and the audio formats used by the virtual cards, 865 otherwise you'll get no sound. It's not recommended to disable 866 this option unless you want to use 5.1 or 7.1 audio, as mixing 867 engine only supports mono and stereo audio. Default is on. 868 869 ``in|out.fixed-settings=on|off`` 870 Use fixed settings for host audio. When off, it will change 871 based on how the guest opens the sound card. In this case you 872 must not specify frequency, channels or format. Default is on. 873 874 ``in|out.frequency=frequency`` 875 Specify the frequency to use when using fixed-settings. Default 876 is 44100Hz. 877 878 ``in|out.channels=channels`` 879 Specify the number of channels to use when using fixed-settings. 880 Default is 2 (stereo). 881 882 ``in|out.format=format`` 883 Specify the sample format to use when using fixed-settings. 884 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``, 885 ``u32``, ``f32``. Default is ``s16``. 886 887 ``in|out.voices=voices`` 888 Specify the number of voices to use. Default is 1. 889 890 ``in|out.buffer-length=usecs`` 891 Sets the size of the buffer in microseconds. 892 893``-audiodev none,id=id[,prop[=value][,...]]`` 894 Creates a dummy backend that discards all outputs. This backend has 895 no backend specific properties. 896 897``-audiodev alsa,id=id[,prop[=value][,...]]`` 898 Creates backend using the ALSA. This backend is only available on 899 Linux. 900 901 ALSA specific options are: 902 903 ``in|out.dev=device`` 904 Specify the ALSA device to use for input and/or output. Default 905 is ``default``. 906 907 ``in|out.period-length=usecs`` 908 Sets the period length in microseconds. 909 910 ``in|out.try-poll=on|off`` 911 Attempt to use poll mode with the device. Default is on. 912 913 ``threshold=threshold`` 914 Threshold (in microseconds) when playback starts. Default is 0. 915 916``-audiodev coreaudio,id=id[,prop[=value][,...]]`` 917 Creates a backend using Apple's Core Audio. This backend is only 918 available on Mac OS and only supports playback. 919 920 Core Audio specific options are: 921 922 ``in|out.buffer-count=count`` 923 Sets the count of the buffers. 924 925``-audiodev dsound,id=id[,prop[=value][,...]]`` 926 Creates a backend using Microsoft's DirectSound. This backend is 927 only available on Windows and only supports playback. 928 929 DirectSound specific options are: 930 931 ``latency=usecs`` 932 Add extra usecs microseconds latency to playback. Default is 933 10000 (10 ms). 934 935``-audiodev oss,id=id[,prop[=value][,...]]`` 936 Creates a backend using OSS. This backend is available on most 937 Unix-like systems. 938 939 OSS specific options are: 940 941 ``in|out.dev=device`` 942 Specify the file name of the OSS device to use. Default is 943 ``/dev/dsp``. 944 945 ``in|out.buffer-count=count`` 946 Sets the count of the buffers. 947 948 ``in|out.try-poll=on|of`` 949 Attempt to use poll mode with the device. Default is on. 950 951 ``try-mmap=on|off`` 952 Try using memory mapped device access. Default is off. 953 954 ``exclusive=on|off`` 955 Open the device in exclusive mode (vmix won't work in this 956 case). Default is off. 957 958 ``dsp-policy=policy`` 959 Sets the timing policy (between 0 and 10, where smaller number 960 means smaller latency but higher CPU usage). Use -1 to use 961 buffer sizes specified by ``buffer`` and ``buffer-count``. This 962 option is ignored if you do not have OSS 4. Default is 5. 963 964``-audiodev pa,id=id[,prop[=value][,...]]`` 965 Creates a backend using PulseAudio. This backend is available on 966 most systems. 967 968 PulseAudio specific options are: 969 970 ``server=server`` 971 Sets the PulseAudio server to connect to. 972 973 ``in|out.name=sink`` 974 Use the specified source/sink for recording/playback. 975 976 ``in|out.latency=usecs`` 977 Desired latency in microseconds. The PulseAudio server will try 978 to honor this value but actual latencies may be lower or higher. 979 980``-audiodev pipewire,id=id[,prop[=value][,...]]`` 981 Creates a backend using PipeWire. This backend is available on 982 most systems. 983 984 PipeWire specific options are: 985 986 ``in|out.latency=usecs`` 987 Desired latency in microseconds. 988 989 ``in|out.name=sink`` 990 Use the specified source/sink for recording/playback. 991 992 ``in|out.stream-name`` 993 Specify the name of pipewire stream. 994 995``-audiodev sdl,id=id[,prop[=value][,...]]`` 996 Creates a backend using SDL. This backend is available on most 997 systems, but you should use your platform's native backend if 998 possible. 999 1000 SDL specific options are: 1001 1002 ``in|out.buffer-count=count`` 1003 Sets the count of the buffers. 1004 1005``-audiodev sndio,id=id[,prop[=value][,...]]`` 1006 Creates a backend using SNDIO. This backend is available on 1007 OpenBSD and most other Unix-like systems. 1008 1009 Sndio specific options are: 1010 1011 ``in|out.dev=device`` 1012 Specify the sndio device to use for input and/or output. Default 1013 is ``default``. 1014 1015 ``in|out.latency=usecs`` 1016 Sets the desired period length in microseconds. 1017 1018``-audiodev spice,id=id[,prop[=value][,...]]`` 1019 Creates a backend that sends audio through SPICE. This backend 1020 requires ``-spice`` and automatically selected in that case, so 1021 usually you can ignore this option. This backend has no backend 1022 specific properties. 1023 1024``-audiodev wav,id=id[,prop[=value][,...]]`` 1025 Creates a backend that writes audio to a WAV file. 1026 1027 Backend specific options are: 1028 1029 ``path=path`` 1030 Write recorded audio into the specified file. Default is 1031 ``qemu.wav``. 1032ERST 1033 1034DEF("device", HAS_ARG, QEMU_OPTION_device, 1035 "-device driver[,prop[=value][,...]]\n" 1036 " add device (based on driver)\n" 1037 " prop=value,... sets driver properties\n" 1038 " use '-device help' to print all possible drivers\n" 1039 " use '-device driver,help' to print all possible properties\n", 1040 QEMU_ARCH_ALL) 1041SRST 1042``-device driver[,prop[=value][,...]]`` 1043 Add device driver. prop=value sets driver properties. Valid 1044 properties depend on the driver. To get help on possible drivers and 1045 properties, use ``-device help`` and ``-device driver,help``. 1046 1047 Some drivers are: 1048 1049``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]`` 1050 Add an IPMI BMC. This is a simulation of a hardware management 1051 interface processor that normally sits on a system. It provides a 1052 watchdog and the ability to reset and power control the system. You 1053 need to connect this to an IPMI interface to make it useful 1054 1055 The IPMI slave address to use for the BMC. The default is 0x20. This 1056 address is the BMC's address on the I2C network of management 1057 controllers. If you don't know what this means, it is safe to ignore 1058 it. 1059 1060 ``id=id`` 1061 The BMC id for interfaces to use this device. 1062 1063 ``slave_addr=val`` 1064 Define slave address to use for the BMC. The default is 0x20. 1065 1066 ``sdrfile=file`` 1067 file containing raw Sensor Data Records (SDR) data. The default 1068 is none. 1069 1070 ``fruareasize=val`` 1071 size of a Field Replaceable Unit (FRU) area. The default is 1072 1024. 1073 1074 ``frudatafile=file`` 1075 file containing raw Field Replaceable Unit (FRU) inventory data. 1076 The default is none. 1077 1078 ``guid=uuid`` 1079 value for the GUID for the BMC, in standard UUID format. If this 1080 is set, get "Get GUID" command to the BMC will return it. 1081 Otherwise "Get GUID" will return an error. 1082 1083``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]`` 1084 Add a connection to an external IPMI BMC simulator. Instead of 1085 locally emulating the BMC like the above item, instead connect to an 1086 external entity that provides the IPMI services. 1087 1088 A connection is made to an external BMC simulator. If you do this, 1089 it is strongly recommended that you use the "reconnect=" chardev 1090 option to reconnect to the simulator if the connection is lost. Note 1091 that if this is not used carefully, it can be a security issue, as 1092 the interface has the ability to send resets, NMIs, and power off 1093 the VM. It's best if QEMU makes a connection to an external 1094 simulator running on a secure port on localhost, so neither the 1095 simulator nor QEMU is exposed to any outside network. 1096 1097 See the "lanserv/README.vm" file in the OpenIPMI library for more 1098 details on the external interface. 1099 1100``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]`` 1101 Add a KCS IPMI interface on the ISA bus. This also adds a 1102 corresponding ACPI and SMBIOS entries, if appropriate. 1103 1104 ``bmc=id`` 1105 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern 1106 above. 1107 1108 ``ioport=val`` 1109 Define the I/O address of the interface. The default is 0xca0 1110 for KCS. 1111 1112 ``irq=val`` 1113 Define the interrupt to use. The default is 5. To disable 1114 interrupts, set this to 0. 1115 1116``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]`` 1117 Like the KCS interface, but defines a BT interface. The default port 1118 is 0xe4 and the default interrupt is 5. 1119 1120``-device pci-ipmi-kcs,bmc=id`` 1121 Add a KCS IPMI interface on the PCI bus. 1122 1123 ``bmc=id`` 1124 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 1125 1126``-device pci-ipmi-bt,bmc=id`` 1127 Like the KCS interface, but defines a BT interface on the PCI bus. 1128 1129``-device intel-iommu[,option=...]`` 1130 This is only supported by ``-machine q35``, which will enable Intel VT-d 1131 emulation within the guest. It supports below options: 1132 1133 ``intremap=on|off`` (default: auto) 1134 This enables interrupt remapping feature. It's required to enable 1135 complete x2apic. Currently it only supports kvm kernel-irqchip modes 1136 ``off`` or ``split``, while full kernel-irqchip is not yet supported. 1137 The default value is "auto", which will be decided by the mode of 1138 kernel-irqchip. 1139 1140 ``caching-mode=on|off`` (default: off) 1141 This enables caching mode for the VT-d emulated device. When 1142 caching-mode is enabled, each guest DMA buffer mapping will generate an 1143 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in 1144 a synchronous way. It is required for ``-device vfio-pci`` to work 1145 with the VT-d device, because host assigned devices requires to setup 1146 the DMA mapping on the host before guest DMA starts. 1147 1148 ``device-iotlb=on|off`` (default: off) 1149 This enables device-iotlb capability for the emulated VT-d device. So 1150 far virtio/vhost should be the only real user for this parameter, 1151 paired with ats=on configured for the device. 1152 1153 ``aw-bits=39|48`` (default: 39) 1154 This decides the address width of IOVA address space. The address 1155 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for 1156 4-level IOMMU page tables. 1157 1158 Please also refer to the wiki page for general scenarios of VT-d 1159 emulation in QEMU: https://wiki.qemu.org/Features/VT-d. 1160 1161ERST 1162 1163DEF("name", HAS_ARG, QEMU_OPTION_name, 1164 "-name string1[,process=string2][,debug-threads=on|off]\n" 1165 " set the name of the guest\n" 1166 " string1 sets the window title and string2 the process name\n" 1167 " When debug-threads is enabled, individual threads are given a separate name\n" 1168 " NOTE: The thread names are for debugging and not a stable API.\n", 1169 QEMU_ARCH_ALL) 1170SRST 1171``-name name`` 1172 Sets the name of the guest. This name will be displayed in the SDL 1173 window caption. The name will also be used for the VNC server. Also 1174 optionally set the top visible process name in Linux. Naming of 1175 individual threads can also be enabled on Linux to aid debugging. 1176ERST 1177 1178DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 1179 "-uuid %08x-%04x-%04x-%04x-%012x\n" 1180 " specify machine UUID\n", QEMU_ARCH_ALL) 1181SRST 1182``-uuid uuid`` 1183 Set system UUID. 1184ERST 1185 1186DEFHEADING() 1187 1188DEFHEADING(Block device options:) 1189 1190SRST 1191The QEMU block device handling options have a long history and 1192have gone through several iterations as the feature set and complexity 1193of the block layer have grown. Many online guides to QEMU often 1194reference older and deprecated options, which can lead to confusion. 1195 1196The most explicit way to describe disks is to use a combination of 1197``-device`` to specify the hardware device and ``-blockdev`` to 1198describe the backend. The device defines what the guest sees and the 1199backend describes how QEMU handles the data. It is the only guaranteed 1200stable interface for describing block devices and as such is 1201recommended for management tools and scripting. 1202 1203The ``-drive`` option combines the device and backend into a single 1204command line option which is a more human friendly. There is however no 1205interface stability guarantee although some older board models still 1206need updating to work with the modern blockdev forms. 1207 1208Older options like ``-hda`` are essentially macros which expand into 1209``-drive`` options for various drive interfaces. The original forms 1210bake in a lot of assumptions from the days when QEMU was emulating a 1211legacy PC, they are not recommended for modern configurations. 1212 1213ERST 1214 1215DEF("fda", HAS_ARG, QEMU_OPTION_fda, 1216 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 1217DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 1218SRST 1219``-fda file`` 1220 \ 1221``-fdb file`` 1222 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in 1223 the System Emulation Users Guide). 1224ERST 1225 1226DEF("hda", HAS_ARG, QEMU_OPTION_hda, 1227 "-hda/-hdb file use 'file' as hard disk 0/1 image\n", QEMU_ARCH_ALL) 1228DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 1229DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 1230 "-hdc/-hdd file use 'file' as hard disk 2/3 image\n", QEMU_ARCH_ALL) 1231DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 1232SRST 1233``-hda file`` 1234 \ 1235``-hdb file`` 1236 \ 1237``-hdc file`` 1238 \ 1239``-hdd file`` 1240 Use file as hard disk 0, 1, 2 or 3 image on the default bus of the 1241 emulated machine (this is for example the IDE bus on most x86 machines, 1242 but it can also be SCSI, virtio or something else on other target 1243 architectures). See also the :ref:`disk images` chapter in the System 1244 Emulation Users Guide. 1245ERST 1246 1247DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 1248 "-cdrom file use 'file' as CD-ROM image\n", 1249 QEMU_ARCH_ALL) 1250SRST 1251``-cdrom file`` 1252 Use file as CD-ROM image on the default bus of the emulated machine 1253 (which is IDE1 master on x86, so you cannot use ``-hdc`` and ``-cdrom`` 1254 at the same time there). On systems that support it, you can use the 1255 host CD-ROM by using ``/dev/cdrom`` as filename. 1256ERST 1257 1258DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 1259 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 1260 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 1261 " [,read-only=on|off][,auto-read-only=on|off]\n" 1262 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 1263 " [,driver specific parameters...]\n" 1264 " configure a block backend\n", QEMU_ARCH_ALL) 1265SRST 1266``-blockdev option[,option[,option[,...]]]`` 1267 Define a new block driver node. Some of the options apply to all 1268 block drivers, other options are only accepted for a specific block 1269 driver. See below for a list of generic options and options for the 1270 most common block drivers. 1271 1272 Options that expect a reference to another node (e.g. ``file``) can 1273 be given in two ways. Either you specify the node name of an already 1274 existing node (file=node-name), or you define a new node inline, 1275 adding options for the referenced node after a dot 1276 (file.filename=path,file.aio=native). 1277 1278 A block driver node created with ``-blockdev`` can be used for a 1279 guest device by specifying its node name for the ``drive`` property 1280 in a ``-device`` argument that defines a block device. 1281 1282 ``Valid options for any block driver node:`` 1283 ``driver`` 1284 Specifies the block driver to use for the given node. 1285 1286 ``node-name`` 1287 This defines the name of the block driver node by which it 1288 will be referenced later. The name must be unique, i.e. it 1289 must not match the name of a different block driver node, or 1290 (if you use ``-drive`` as well) the ID of a drive. 1291 1292 If no node name is specified, it is automatically generated. 1293 The generated node name is not intended to be predictable 1294 and changes between QEMU invocations. For the top level, an 1295 explicit node name must be specified. 1296 1297 ``read-only`` 1298 Open the node read-only. Guest write attempts will fail. 1299 1300 Note that some block drivers support only read-only access, 1301 either generally or in certain configurations. In this case, 1302 the default value ``read-only=off`` does not work and the 1303 option must be specified explicitly. 1304 1305 ``auto-read-only`` 1306 If ``auto-read-only=on`` is set, QEMU may fall back to 1307 read-only usage even when ``read-only=off`` is requested, or 1308 even switch between modes as needed, e.g. depending on 1309 whether the image file is writable or whether a writing user 1310 is attached to the node. 1311 1312 ``force-share`` 1313 Override the image locking system of QEMU by forcing the 1314 node to utilize weaker shared access for permissions where 1315 it would normally request exclusive access. When there is 1316 the potential for multiple instances to have the same file 1317 open (whether this invocation of QEMU is the first or the 1318 second instance), both instances must permit shared access 1319 for the second instance to succeed at opening the file. 1320 1321 Enabling ``force-share=on`` requires ``read-only=on``. 1322 1323 ``cache.direct`` 1324 The host page cache can be avoided with ``cache.direct=on``. 1325 This will attempt to do disk IO directly to the guest's 1326 memory. QEMU may still perform an internal copy of the data. 1327 1328 ``cache.no-flush`` 1329 In case you don't care about data integrity over host 1330 failures, you can use ``cache.no-flush=on``. This option 1331 tells QEMU that it never needs to write any data to the disk 1332 but can instead keep things in cache. If anything goes 1333 wrong, like your host losing power, the disk storage getting 1334 disconnected accidentally, etc. your image will most 1335 probably be rendered unusable. 1336 1337 ``discard=discard`` 1338 discard is one of "ignore" (or "off") or "unmap" (or "on") 1339 and controls whether ``discard`` (also known as ``trim`` or 1340 ``unmap``) requests are ignored or passed to the filesystem. 1341 Some machine types may not support discard requests. 1342 1343 ``detect-zeroes=detect-zeroes`` 1344 detect-zeroes is "off", "on" or "unmap" and enables the 1345 automatic conversion of plain zero writes by the OS to 1346 driver specific optimized zero write commands. You may even 1347 choose "unmap" if discard is set to "unmap" to allow a zero 1348 write to be converted to an ``unmap`` operation. 1349 1350 ``Driver-specific options for file`` 1351 This is the protocol-level block driver for accessing regular 1352 files. 1353 1354 ``filename`` 1355 The path to the image file in the local filesystem 1356 1357 ``aio`` 1358 Specifies the AIO backend (threads/native/io_uring, 1359 default: threads) 1360 1361 ``locking`` 1362 Specifies whether the image file is protected with Linux OFD 1363 / POSIX locks. The default is to use the Linux Open File 1364 Descriptor API if available, otherwise no lock is applied. 1365 (auto/on/off, default: auto) 1366 1367 Example: 1368 1369 :: 1370 1371 -blockdev driver=file,node-name=disk,filename=disk.img 1372 1373 ``Driver-specific options for raw`` 1374 This is the image format block driver for raw images. It is 1375 usually stacked on top of a protocol level block driver such as 1376 ``file``. 1377 1378 ``file`` 1379 Reference to or definition of the data source block driver 1380 node (e.g. a ``file`` driver node) 1381 1382 Example 1: 1383 1384 :: 1385 1386 -blockdev driver=file,node-name=disk_file,filename=disk.img 1387 -blockdev driver=raw,node-name=disk,file=disk_file 1388 1389 Example 2: 1390 1391 :: 1392 1393 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1394 1395 ``Driver-specific options for qcow2`` 1396 This is the image format block driver for qcow2 images. It is 1397 usually stacked on top of a protocol level block driver such as 1398 ``file``. 1399 1400 ``file`` 1401 Reference to or definition of the data source block driver 1402 node (e.g. a ``file`` driver node) 1403 1404 ``backing`` 1405 Reference to or definition of the backing file block device 1406 (default is taken from the image file). It is allowed to 1407 pass ``null`` here in order to disable the default backing 1408 file. 1409 1410 ``lazy-refcounts`` 1411 Whether to enable the lazy refcounts feature (on/off; 1412 default is taken from the image file) 1413 1414 ``cache-size`` 1415 The maximum total size of the L2 table and refcount block 1416 caches in bytes (default: the sum of l2-cache-size and 1417 refcount-cache-size) 1418 1419 ``l2-cache-size`` 1420 The maximum size of the L2 table cache in bytes (default: if 1421 cache-size is not specified - 32M on Linux platforms, and 8M 1422 on non-Linux platforms; otherwise, as large as possible 1423 within the cache-size, while permitting the requested or the 1424 minimal refcount cache size) 1425 1426 ``refcount-cache-size`` 1427 The maximum size of the refcount block cache in bytes 1428 (default: 4 times the cluster size; or if cache-size is 1429 specified, the part of it which is not used for the L2 1430 cache) 1431 1432 ``cache-clean-interval`` 1433 Clean unused entries in the L2 and refcount caches. The 1434 interval is in seconds. The default value is 600 on 1435 supporting platforms, and 0 on other platforms. Setting it 1436 to 0 disables this feature. 1437 1438 ``pass-discard-request`` 1439 Whether discard requests to the qcow2 device should be 1440 forwarded to the data source (on/off; default: on if 1441 discard=unmap is specified, off otherwise) 1442 1443 ``pass-discard-snapshot`` 1444 Whether discard requests for the data source should be 1445 issued when a snapshot operation (e.g. deleting a snapshot) 1446 frees clusters in the qcow2 file (on/off; default: on) 1447 1448 ``pass-discard-other`` 1449 Whether discard requests for the data source should be 1450 issued on other occasions where a cluster gets freed 1451 (on/off; default: off) 1452 1453 ``discard-no-unref`` 1454 When enabled, discards from the guest will not cause cluster 1455 allocations to be relinquished. This prevents qcow2 fragmentation 1456 that would be caused by such discards. Besides potential 1457 performance degradation, such fragmentation can lead to increased 1458 allocation of clusters past the end of the image file, 1459 resulting in image files whose file length can grow much larger 1460 than their guest disk size would suggest. 1461 If image file length is of concern (e.g. when storing qcow2 1462 images directly on block devices), you should consider enabling 1463 this option. 1464 1465 ``overlap-check`` 1466 Which overlap checks to perform for writes to the image 1467 (none/constant/cached/all; default: cached). For details or 1468 finer granularity control refer to the QAPI documentation of 1469 ``blockdev-add``. 1470 1471 Example 1: 1472 1473 :: 1474 1475 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1476 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1477 1478 Example 2: 1479 1480 :: 1481 1482 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1483 1484 ``Driver-specific options for other drivers`` 1485 Please refer to the QAPI documentation of the ``blockdev-add`` 1486 QMP command. 1487ERST 1488 1489DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1490 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1491 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1492 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1493 " [,werror=ignore|stop|report|enospc][,id=name]\n" 1494 " [,aio=threads|native|io_uring]\n" 1495 " [,readonly=on|off][,copy-on-read=on|off]\n" 1496 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1497 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1498 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1499 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1500 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1501 " [[,iops_size=is]]\n" 1502 " [[,group=g]]\n" 1503 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1504SRST 1505``-drive option[,option[,option[,...]]]`` 1506 Define a new drive. This includes creating a block driver node (the 1507 backend) as well as a guest device, and is mostly a shortcut for 1508 defining the corresponding ``-blockdev`` and ``-device`` options. 1509 1510 ``-drive`` accepts all options that are accepted by ``-blockdev``. 1511 In addition, it knows the following options: 1512 1513 ``file=file`` 1514 This option defines which disk image (see the :ref:`disk images` 1515 chapter in the System Emulation Users Guide) to use with this drive. 1516 If the filename contains comma, you must double it (for instance, 1517 "file=my,,file" to use file "my,file"). 1518 1519 Special files such as iSCSI devices can be specified using 1520 protocol specific URLs. See the section for "Device URL Syntax" 1521 for more information. 1522 1523 ``if=interface`` 1524 This option defines on which type on interface the drive is 1525 connected. Available types are: ide, scsi, sd, mtd, floppy, 1526 pflash, virtio, none. 1527 1528 ``bus=bus,unit=unit`` 1529 These options define where is connected the drive by defining 1530 the bus number and the unit id. 1531 1532 ``index=index`` 1533 This option defines where the drive is connected by using an 1534 index in the list of available connectors of a given interface 1535 type. 1536 1537 ``media=media`` 1538 This option defines the type of the media: disk or cdrom. 1539 1540 ``snapshot=snapshot`` 1541 snapshot is "on" or "off" and controls snapshot mode for the 1542 given drive (see ``-snapshot``). 1543 1544 ``cache=cache`` 1545 cache is "none", "writeback", "unsafe", "directsync" or 1546 "writethrough" and controls how the host cache is used to access 1547 block data. This is a shortcut that sets the ``cache.direct`` 1548 and ``cache.no-flush`` options (as in ``-blockdev``), and 1549 additionally ``cache.writeback``, which provides a default for 1550 the ``write-cache`` option of block guest devices (as in 1551 ``-device``). The modes correspond to the following settings: 1552 1553 ============= =============== ============ ============== 1554 \ cache.writeback cache.direct cache.no-flush 1555 ============= =============== ============ ============== 1556 writeback on off off 1557 none on on off 1558 writethrough off off off 1559 directsync off on off 1560 unsafe on off on 1561 ============= =============== ============ ============== 1562 1563 The default mode is ``cache=writeback``. 1564 1565 ``aio=aio`` 1566 aio is "threads", "native", or "io_uring" and selects between pthread 1567 based disk I/O, native Linux AIO, or Linux io_uring API. 1568 1569 ``format=format`` 1570 Specify which disk format will be used rather than detecting the 1571 format. Can be used to specify format=raw to avoid interpreting 1572 an untrusted format header. 1573 1574 ``werror=action,rerror=action`` 1575 Specify which action to take on write and read errors. Valid 1576 actions are: "ignore" (ignore the error and try to continue), 1577 "stop" (pause QEMU), "report" (report the error to the guest), 1578 "enospc" (pause QEMU only if the host disk is full; report the 1579 error to the guest otherwise). The default setting is 1580 ``werror=enospc`` and ``rerror=report``. 1581 1582 ``copy-on-read=copy-on-read`` 1583 copy-on-read is "on" or "off" and enables whether to copy read 1584 backing file sectors into the image file. 1585 1586 ``bps=b,bps_rd=r,bps_wr=w`` 1587 Specify bandwidth throttling limits in bytes per second, either 1588 for all request types or for reads or writes only. Small values 1589 can lead to timeouts or hangs inside the guest. A safe minimum 1590 for disks is 2 MB/s. 1591 1592 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm`` 1593 Specify bursts in bytes per second, either for all request types 1594 or for reads or writes only. Bursts allow the guest I/O to spike 1595 above the limit temporarily. 1596 1597 ``iops=i,iops_rd=r,iops_wr=w`` 1598 Specify request rate limits in requests per second, either for 1599 all request types or for reads or writes only. 1600 1601 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm`` 1602 Specify bursts in requests per second, either for all request 1603 types or for reads or writes only. Bursts allow the guest I/O to 1604 spike above the limit temporarily. 1605 1606 ``iops_size=is`` 1607 Let every is bytes of a request count as a new request for iops 1608 throttling purposes. Use this option to prevent guests from 1609 circumventing iops limits by sending fewer but larger requests. 1610 1611 ``group=g`` 1612 Join a throttling quota group with given name g. All drives that 1613 are members of the same group are accounted for together. Use 1614 this option to prevent guests from circumventing throttling 1615 limits by using many small disks instead of a single larger 1616 disk. 1617 1618 By default, the ``cache.writeback=on`` mode is used. It will report 1619 data writes as completed as soon as the data is present in the host 1620 page cache. This is safe as long as your guest OS makes sure to 1621 correctly flush disk caches where needed. If your guest OS does not 1622 handle volatile disk write caches correctly and your host crashes or 1623 loses power, then the guest may experience data corruption. 1624 1625 For such guests, you should consider using ``cache.writeback=off``. 1626 This means that the host page cache will be used to read and write 1627 data, but write notification will be sent to the guest only after 1628 QEMU has made sure to flush each write to the disk. Be aware that 1629 this has a major impact on performance. 1630 1631 When using the ``-snapshot`` option, unsafe caching is always used. 1632 1633 Copy-on-read avoids accessing the same backing file sectors 1634 repeatedly and is useful when the backing file is over a slow 1635 network. By default copy-on-read is off. 1636 1637 Instead of ``-cdrom`` you can use: 1638 1639 .. parsed-literal:: 1640 1641 |qemu_system| -drive file=file,index=2,media=cdrom 1642 1643 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use: 1644 1645 .. parsed-literal:: 1646 1647 |qemu_system| -drive file=file,index=0,media=disk 1648 |qemu_system| -drive file=file,index=1,media=disk 1649 |qemu_system| -drive file=file,index=2,media=disk 1650 |qemu_system| -drive file=file,index=3,media=disk 1651 1652 You can open an image using pre-opened file descriptors from an fd 1653 set: 1654 1655 .. parsed-literal:: 1656 1657 |qemu_system| \\ 1658 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 1659 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 1660 -drive file=/dev/fdset/2,index=0,media=disk 1661 1662 You can connect a CDROM to the slave of ide0: 1663 1664 .. parsed-literal:: 1665 1666 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom 1667 1668 If you don't specify the "file=" argument, you define an empty 1669 drive: 1670 1671 .. parsed-literal:: 1672 1673 |qemu_system_x86| -drive if=ide,index=1,media=cdrom 1674 1675 Instead of ``-fda``, ``-fdb``, you can use: 1676 1677 .. parsed-literal:: 1678 1679 |qemu_system_x86| -drive file=file,index=0,if=floppy 1680 |qemu_system_x86| -drive file=file,index=1,if=floppy 1681 1682 By default, interface is "ide" and index is automatically 1683 incremented: 1684 1685 .. parsed-literal:: 1686 1687 |qemu_system_x86| -drive file=a -drive file=b 1688 1689 is interpreted like: 1690 1691 .. parsed-literal:: 1692 1693 |qemu_system_x86| -hda a -hdb b 1694ERST 1695 1696DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1697 "-mtdblock file use 'file' as on-board Flash memory image\n", 1698 QEMU_ARCH_ALL) 1699SRST 1700``-mtdblock file`` 1701 Use file as on-board Flash memory image. 1702ERST 1703 1704DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1705 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1706SRST 1707``-sd file`` 1708 Use file as SecureDigital card image. 1709ERST 1710 1711DEF("snapshot", 0, QEMU_OPTION_snapshot, 1712 "-snapshot write to temporary files instead of disk image files\n", 1713 QEMU_ARCH_ALL) 1714SRST 1715``-snapshot`` 1716 Write to temporary files instead of disk image files. In this case, 1717 the raw disk image you use is not written back. You can however 1718 force the write back by pressing C-a s (see the :ref:`disk images` 1719 chapter in the System Emulation Users Guide). 1720 1721 .. warning:: 1722 snapshot is incompatible with ``-blockdev`` (instead use qemu-img 1723 to manually create snapshot images to attach to your blockdev). 1724 If you have mixed ``-blockdev`` and ``-drive`` declarations you 1725 can use the 'snapshot' property on your drive declarations 1726 instead of this global option. 1727 1728ERST 1729 1730DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1731 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1732 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n" 1733 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1734 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1735 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1736 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1737 " [[,throttling.iops-size=is]]\n" 1738 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly=on]\n" 1739 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly=on]\n" 1740 "-fsdev synth,id=id\n", 1741 QEMU_ARCH_ALL) 1742 1743SRST 1744``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly=on][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]`` 1745 \ 1746``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly=on]`` 1747 \ 1748``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly=on]`` 1749 \ 1750``-fsdev synth,id=id[,readonly=on]`` 1751 Define a new file system device. Valid options are: 1752 1753 ``local`` 1754 Accesses to the filesystem are done by QEMU. 1755 1756 ``proxy`` 1757 Accesses to the filesystem are done by virtfs-proxy-helper(1). This 1758 option is deprecated (since QEMU 8.1) and will be removed in a future 1759 version of QEMU. Use ``local`` instead. 1760 1761 ``synth`` 1762 Synthetic filesystem, only used by QTests. 1763 1764 ``id=id`` 1765 Specifies identifier for this device. 1766 1767 ``path=path`` 1768 Specifies the export path for the file system device. Files 1769 under this path will be available to the 9p client on the guest. 1770 1771 ``security_model=security_model`` 1772 Specifies the security model to be used for this export path. 1773 Supported security models are "passthrough", "mapped-xattr", 1774 "mapped-file" and "none". In "passthrough" security model, files 1775 are stored using the same credentials as they are created on the 1776 guest. This requires QEMU to run as root. In "mapped-xattr" 1777 security model, some of the file attributes like uid, gid, mode 1778 bits and link target are stored as file attributes. For 1779 "mapped-file" these attributes are stored in the hidden 1780 .virtfs\_metadata directory. Directories exported by this 1781 security model cannot interact with other unix tools. "none" 1782 security model is same as passthrough except the sever won't 1783 report failures if it fails to set file attributes like 1784 ownership. Security model is mandatory only for local fsdriver. 1785 Other fsdrivers (like proxy) don't take security model as a 1786 parameter. 1787 1788 ``writeout=writeout`` 1789 This is an optional argument. The only supported value is 1790 "immediate". This means that host page cache will be used to 1791 read and write data but write notification will be sent to the 1792 guest only when the data has been reported as written by the 1793 storage subsystem. 1794 1795 ``readonly=on`` 1796 Enables exporting 9p share as a readonly mount for guests. By 1797 default read-write access is given. 1798 1799 ``socket=socket`` 1800 Enables proxy filesystem driver to use passed socket file for 1801 communicating with virtfs-proxy-helper(1). 1802 1803 ``sock_fd=sock_fd`` 1804 Enables proxy filesystem driver to use passed socket descriptor 1805 for communicating with virtfs-proxy-helper(1). Usually a helper 1806 like libvirt will create socketpair and pass one of the fds as 1807 sock\_fd. 1808 1809 ``fmode=fmode`` 1810 Specifies the default mode for newly created files on the host. 1811 Works only with security models "mapped-xattr" and 1812 "mapped-file". 1813 1814 ``dmode=dmode`` 1815 Specifies the default mode for newly created directories on the 1816 host. Works only with security models "mapped-xattr" and 1817 "mapped-file". 1818 1819 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w`` 1820 Specify bandwidth throttling limits in bytes per second, either 1821 for all request types or for reads or writes only. 1822 1823 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm`` 1824 Specify bursts in bytes per second, either for all request types 1825 or for reads or writes only. Bursts allow the guest I/O to spike 1826 above the limit temporarily. 1827 1828 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w`` 1829 Specify request rate limits in requests per second, either for 1830 all request types or for reads or writes only. 1831 1832 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm`` 1833 Specify bursts in requests per second, either for all request 1834 types or for reads or writes only. Bursts allow the guest I/O to 1835 spike above the limit temporarily. 1836 1837 ``throttling.iops-size=is`` 1838 Let every is bytes of a request count as a new request for iops 1839 throttling purposes. 1840 1841 -fsdev option is used along with -device driver "virtio-9p-...". 1842 1843``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag`` 1844 Options for virtio-9p-... driver are: 1845 1846 ``type`` 1847 Specifies the variant to be used. Supported values are "pci", 1848 "ccw" or "device", depending on the machine type. 1849 1850 ``fsdev=id`` 1851 Specifies the id value specified along with -fsdev option. 1852 1853 ``mount_tag=mount_tag`` 1854 Specifies the tag name to be used by the guest to mount this 1855 export point. 1856ERST 1857 1858DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1859 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1860 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1861 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly=on]\n" 1862 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly=on]\n" 1863 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n", 1864 QEMU_ARCH_ALL) 1865 1866SRST 1867``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly=on] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]`` 1868 \ 1869``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1870 \ 1871``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1872 \ 1873``-virtfs synth,mount_tag=mount_tag`` 1874 Define a new virtual filesystem device and expose it to the guest using 1875 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain 1876 directory on host is made directly accessible by guest as a pass-through 1877 file system by using the 9P network protocol for communication between 1878 host and guests, if desired even accessible, shared by several guests 1879 simultaneously. 1880 1881 Note that ``-virtfs`` is actually just a convenience shortcut for its 1882 generalized form ``-fsdev -device virtio-9p-pci``. 1883 1884 The general form of pass-through file system options are: 1885 1886 ``local`` 1887 Accesses to the filesystem are done by QEMU. 1888 1889 ``proxy`` 1890 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1891 This option is deprecated (since QEMU 8.1) and will be removed in a 1892 future version of QEMU. Use ``local`` instead. 1893 1894 ``synth`` 1895 Synthetic filesystem, only used by QTests. 1896 1897 ``id=id`` 1898 Specifies identifier for the filesystem device 1899 1900 ``path=path`` 1901 Specifies the export path for the file system device. Files 1902 under this path will be available to the 9p client on the guest. 1903 1904 ``security_model=security_model`` 1905 Specifies the security model to be used for this export path. 1906 Supported security models are "passthrough", "mapped-xattr", 1907 "mapped-file" and "none". In "passthrough" security model, files 1908 are stored using the same credentials as they are created on the 1909 guest. This requires QEMU to run as root. In "mapped-xattr" 1910 security model, some of the file attributes like uid, gid, mode 1911 bits and link target are stored as file attributes. For 1912 "mapped-file" these attributes are stored in the hidden 1913 .virtfs\_metadata directory. Directories exported by this 1914 security model cannot interact with other unix tools. "none" 1915 security model is same as passthrough except the sever won't 1916 report failures if it fails to set file attributes like 1917 ownership. Security model is mandatory only for local fsdriver. 1918 Other fsdrivers (like proxy) don't take security model as a 1919 parameter. 1920 1921 ``writeout=writeout`` 1922 This is an optional argument. The only supported value is 1923 "immediate". This means that host page cache will be used to 1924 read and write data but write notification will be sent to the 1925 guest only when the data has been reported as written by the 1926 storage subsystem. 1927 1928 ``readonly=on`` 1929 Enables exporting 9p share as a readonly mount for guests. By 1930 default read-write access is given. 1931 1932 ``socket=socket`` 1933 Enables proxy filesystem driver to use passed socket file for 1934 communicating with virtfs-proxy-helper(1). Usually a helper like 1935 libvirt will create socketpair and pass one of the fds as 1936 sock\_fd. 1937 1938 ``sock_fd`` 1939 Enables proxy filesystem driver to use passed 'sock\_fd' as the 1940 socket descriptor for interfacing with virtfs-proxy-helper(1). 1941 1942 ``fmode=fmode`` 1943 Specifies the default mode for newly created files on the host. 1944 Works only with security models "mapped-xattr" and 1945 "mapped-file". 1946 1947 ``dmode=dmode`` 1948 Specifies the default mode for newly created directories on the 1949 host. Works only with security models "mapped-xattr" and 1950 "mapped-file". 1951 1952 ``mount_tag=mount_tag`` 1953 Specifies the tag name to be used by the guest to mount this 1954 export point. 1955 1956 ``multidevs=multidevs`` 1957 Specifies how to deal with multiple devices being shared with a 1958 9p export. Supported behaviours are either "remap", "forbid" or 1959 "warn". The latter is the default behaviour on which virtfs 9p 1960 expects only one device to be shared with the same export, and 1961 if more than one device is shared and accessed via the same 9p 1962 export then only a warning message is logged (once) by qemu on 1963 host side. In order to avoid file ID collisions on guest you 1964 should either create a separate virtfs export for each device to 1965 be shared with guests (recommended way) or you might use "remap" 1966 instead which allows you to share multiple devices with only one 1967 export instead, which is achieved by remapping the original 1968 inode numbers from host to guest in a way that would prevent 1969 such collisions. Remapping inodes in such use cases is required 1970 because the original device IDs from host are never passed and 1971 exposed on guest. Instead all files of an export shared with 1972 virtfs always share the same device id on guest. So two files 1973 with identical inode numbers but from actually different devices 1974 on host would otherwise cause a file ID collision and hence 1975 potential misbehaviours on guest. "forbid" on the other hand 1976 assumes like "warn" that only one device is shared by the same 1977 export, however it will not only log a warning message but also 1978 deny access to additional devices on guest. Note though that 1979 "forbid" does currently not block all possible file access 1980 operations (e.g. readdir() would still return entries from other 1981 devices). 1982ERST 1983 1984DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1985 "-iscsi [user=user][,password=password][,password-secret=secret-id]\n" 1986 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE]\n" 1987 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1988 " [,timeout=timeout]\n" 1989 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1990 1991SRST 1992``-iscsi`` 1993 Configure iSCSI session parameters. 1994ERST 1995 1996DEFHEADING() 1997 1998DEFHEADING(USB convenience options:) 1999 2000DEF("usb", 0, QEMU_OPTION_usb, 2001 "-usb enable on-board USB host controller (if not enabled by default)\n", 2002 QEMU_ARCH_ALL) 2003SRST 2004``-usb`` 2005 Enable USB emulation on machine types with an on-board USB host 2006 controller (if not enabled by default). Note that on-board USB host 2007 controllers may not support USB 3.0. In this case 2008 ``-device qemu-xhci`` can be used instead on machines with PCI. 2009ERST 2010 2011DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 2012 "-usbdevice name add the host or guest USB device 'name'\n", 2013 QEMU_ARCH_ALL) 2014SRST 2015``-usbdevice devname`` 2016 Add the USB device devname, and enable an on-board USB controller 2017 if possible and necessary (just like it can be done via 2018 ``-machine usb=on``). Note that this option is mainly intended for 2019 the user's convenience only. More fine-grained control can be 2020 achieved by selecting a USB host controller (if necessary) and the 2021 desired USB device via the ``-device`` option instead. For example, 2022 instead of using ``-usbdevice mouse`` it is possible to use 2023 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse 2024 to a USB 3.0 controller instead (at least on machines that support 2025 PCI and do not have an USB controller enabled by default yet). 2026 For more details, see the chapter about 2027 :ref:`Connecting USB devices` in the System Emulation Users Guide. 2028 Possible devices for devname are: 2029 2030 ``braille`` 2031 Braille device. This will use BrlAPI to display the braille 2032 output on a real or fake device (i.e. it also creates a 2033 corresponding ``braille`` chardev automatically beside the 2034 ``usb-braille`` USB device). 2035 2036 ``keyboard`` 2037 Standard USB keyboard. Will override the PS/2 keyboard (if present). 2038 2039 ``mouse`` 2040 Virtual Mouse. This will override the PS/2 mouse emulation when 2041 activated. 2042 2043 ``tablet`` 2044 Pointer device that uses absolute coordinates (like a 2045 touchscreen). This means QEMU is able to report the mouse 2046 position without having to grab the mouse. Also overrides the 2047 PS/2 mouse emulation when activated. 2048 2049 ``wacom-tablet`` 2050 Wacom PenPartner USB tablet. 2051 2052 2053ERST 2054 2055DEFHEADING() 2056 2057DEFHEADING(Display options:) 2058 2059DEF("display", HAS_ARG, QEMU_OPTION_display, 2060#if defined(CONFIG_SPICE) 2061 "-display spice-app[,gl=on|off]\n" 2062#endif 2063#if defined(CONFIG_SDL) 2064 "-display sdl[,gl=on|core|es|off][,grab-mod=<mod>][,show-cursor=on|off]\n" 2065 " [,window-close=on|off]\n" 2066#endif 2067#if defined(CONFIG_GTK) 2068 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n" 2069 " [,show-tabs=on|off][,show-cursor=on|off][,window-close=on|off]\n" 2070 " [,show-menubar=on|off]\n" 2071#endif 2072#if defined(CONFIG_VNC) 2073 "-display vnc=<display>[,<optargs>]\n" 2074#endif 2075#if defined(CONFIG_CURSES) 2076 "-display curses[,charset=<encoding>]\n" 2077#endif 2078#if defined(CONFIG_COCOA) 2079 "-display cocoa[,full-grab=on|off][,swap-opt-cmd=on|off]\n" 2080#endif 2081#if defined(CONFIG_OPENGL) 2082 "-display egl-headless[,rendernode=<file>]\n" 2083#endif 2084#if defined(CONFIG_DBUS_DISPLAY) 2085 "-display dbus[,addr=<dbusaddr>]\n" 2086 " [,gl=on|core|es|off][,rendernode=<file>]\n" 2087#endif 2088#if defined(CONFIG_COCOA) 2089 "-display cocoa[,show-cursor=on|off][,left-command-key=on|off]\n" 2090#endif 2091 "-display none\n" 2092 " select display backend type\n" 2093 " The default display is equivalent to\n " 2094#if defined(CONFIG_GTK) 2095 "\"-display gtk\"\n" 2096#elif defined(CONFIG_SDL) 2097 "\"-display sdl\"\n" 2098#elif defined(CONFIG_COCOA) 2099 "\"-display cocoa\"\n" 2100#elif defined(CONFIG_VNC) 2101 "\"-vnc localhost:0,to=99,id=default\"\n" 2102#else 2103 "\"-display none\"\n" 2104#endif 2105 , QEMU_ARCH_ALL) 2106SRST 2107``-display type`` 2108 Select type of display to use. Use ``-display help`` to list the available 2109 display types. Valid values for type are 2110 2111 ``spice-app[,gl=on|off]`` 2112 Start QEMU as a Spice server and launch the default Spice client 2113 application. The Spice server will redirect the serial consoles 2114 and QEMU monitors. (Since 4.0) 2115 2116 ``dbus`` 2117 Export the display over D-Bus interfaces. (Since 7.0) 2118 2119 The connection is registered with the "org.qemu" name (and queued when 2120 already owned). 2121 2122 ``addr=<dbusaddr>`` : D-Bus bus address to connect to. 2123 2124 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``. 2125 2126 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface 2127 will share framebuffers with DMABUF file descriptors). 2128 2129 ``sdl`` 2130 Display video output via SDL (usually in a separate graphics 2131 window; see the SDL documentation for other possibilities). 2132 Valid parameters are: 2133 2134 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling 2135 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be 2136 either ``lshift-lctrl-lalt`` or ``rctrl``. 2137 2138 ``gl=on|off|core|es`` : Use OpenGL for displaying 2139 2140 ``show-cursor=on|off`` : Force showing the mouse cursor 2141 2142 ``window-close=on|off`` : Allow to quit qemu with window close button 2143 2144 ``gtk`` 2145 Display video output in a GTK window. This interface provides 2146 drop-down menus and other UI elements to configure and control 2147 the VM during runtime. Valid parameters are: 2148 2149 ``full-screen=on|off`` : Start in fullscreen mode 2150 2151 ``gl=on|off`` : Use OpenGL for displaying 2152 2153 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover 2154 2155 ``show-tabs=on|off`` : Display the tab bar for switching between the 2156 various graphical interfaces (e.g. VGA and 2157 virtual console character devices) by default. 2158 2159 ``show-cursor=on|off`` : Force showing the mouse cursor 2160 2161 ``window-close=on|off`` : Allow to quit qemu with window close button 2162 2163 ``show-menubar=on|off`` : Display the main window menubar, defaults to "on" 2164 2165 ``zoom-to-fit=on|off`` : Expand video output to the window size, 2166 defaults to "off" 2167 2168 ``curses[,charset=<encoding>]`` 2169 Display video output via curses. For graphics device models 2170 which support a text mode, QEMU can display this output using a 2171 curses/ncurses interface. Nothing is displayed when the graphics 2172 device is in graphical mode or if the graphics device does not 2173 support a text mode. Generally only the VGA device models 2174 support text mode. The font charset used by the guest can be 2175 specified with the ``charset`` option, for example 2176 ``charset=CP850`` for IBM CP850 encoding. The default is 2177 ``CP437``. 2178 2179 ``cocoa`` 2180 Display video output in a Cocoa window. Mac only. This interface 2181 provides drop-down menus and other UI elements to configure and 2182 control the VM during runtime. Valid parameters are: 2183 2184 ``show-cursor=on|off`` : Force showing the mouse cursor 2185 2186 ``left-command-key=on|off`` : Disable forwarding left command key to host 2187 2188 ``egl-headless[,rendernode=<file>]`` 2189 Offload all OpenGL operations to a local DRI device. For any 2190 graphical display, this display needs to be paired with either 2191 VNC or SPICE displays. 2192 2193 ``vnc=<display>`` 2194 Start a VNC server on display <display> 2195 2196 ``none`` 2197 Do not display video output. The guest will still see an 2198 emulated graphics card, but its output will not be displayed to 2199 the QEMU user. This option differs from the -nographic option in 2200 that it only affects what is done with video output; -nographic 2201 also changes the destination of the serial and parallel port 2202 data. 2203ERST 2204 2205DEF("nographic", 0, QEMU_OPTION_nographic, 2206 "-nographic disable graphical output and redirect serial I/Os to console\n", 2207 QEMU_ARCH_ALL) 2208SRST 2209``-nographic`` 2210 Normally, if QEMU is compiled with graphical window support, it 2211 displays output such as guest graphics, guest console, and the QEMU 2212 monitor in a window. With this option, you can totally disable 2213 graphical output so that QEMU is a simple command line application. 2214 The emulated serial port is redirected on the console and muxed with 2215 the monitor (unless redirected elsewhere explicitly). Therefore, you 2216 can still use QEMU to debug a Linux kernel with a serial console. 2217 Use C-a h for help on switching between the console and monitor. 2218ERST 2219 2220#ifdef CONFIG_SPICE 2221DEF("spice", HAS_ARG, QEMU_OPTION_spice, 2222 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 2223 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 2224 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 2225 " [,x509-dh-key-file=<file>][,addr=addr]\n" 2226 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n" 2227 " [,tls-ciphers=<list>]\n" 2228 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 2229 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 2230 " [,sasl=on|off][,disable-ticketing=on|off]\n" 2231 " [,password-secret=<secret-id>]\n" 2232 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 2233 " [,jpeg-wan-compression=[auto|never|always]]\n" 2234 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 2235 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n" 2236 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n" 2237 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 2238 " [,gl=[on|off]][,rendernode=<file>]\n" 2239 " enable spice\n" 2240 " at least one of {port, tls-port} is mandatory\n", 2241 QEMU_ARCH_ALL) 2242#endif 2243SRST 2244``-spice option[,option[,...]]`` 2245 Enable the spice remote desktop protocol. Valid options are 2246 2247 ``port=<nr>`` 2248 Set the TCP port spice is listening on for plaintext channels. 2249 2250 ``addr=<addr>`` 2251 Set the IP address spice is listening on. Default is any 2252 address. 2253 2254 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off`` 2255 Force using the specified IP version. 2256 2257 ``password-secret=<secret-id>`` 2258 Set the ID of the ``secret`` object containing the password 2259 you need to authenticate. 2260 2261 ``sasl=on|off`` 2262 Require that the client use SASL to authenticate with the spice. 2263 The exact choice of authentication method used is controlled 2264 from the system / user's SASL configuration file for the 'qemu' 2265 service. This is typically found in /etc/sasl2/qemu.conf. If 2266 running QEMU as an unprivileged user, an environment variable 2267 SASL\_CONF\_PATH can be used to make it search alternate 2268 locations for the service config. While some SASL auth methods 2269 can also provide data encryption (eg GSSAPI), it is recommended 2270 that SASL always be combined with the 'tls' and 'x509' settings 2271 to enable use of SSL and server certificates. This ensures a 2272 data encryption preventing compromise of authentication 2273 credentials. 2274 2275 ``disable-ticketing=on|off`` 2276 Allow client connects without authentication. 2277 2278 ``disable-copy-paste=on|off`` 2279 Disable copy paste between the client and the guest. 2280 2281 ``disable-agent-file-xfer=on|off`` 2282 Disable spice-vdagent based file-xfer between the client and the 2283 guest. 2284 2285 ``tls-port=<nr>`` 2286 Set the TCP port spice is listening on for encrypted channels. 2287 2288 ``x509-dir=<dir>`` 2289 Set the x509 file directory. Expects same filenames as -vnc 2290 $display,x509=$dir 2291 2292 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>`` 2293 The x509 file names can also be configured individually. 2294 2295 ``tls-ciphers=<list>`` 2296 Specify which ciphers to use. 2297 2298 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]`` 2299 Force specific channel to be used with or without TLS 2300 encryption. The options can be specified multiple times to 2301 configure multiple channels. The special name "default" can be 2302 used to set the default mode. For channels which are not 2303 explicitly forced into one mode the spice client is allowed to 2304 pick tls/plaintext as he pleases. 2305 2306 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]`` 2307 Configure image compression (lossless). Default is auto\_glz. 2308 2309 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]`` 2310 Configure wan image compression (lossy for slow links). Default 2311 is auto. 2312 2313 ``streaming-video=[off|all|filter]`` 2314 Configure video stream detection. Default is off. 2315 2316 ``agent-mouse=[on|off]`` 2317 Enable/disable passing mouse events via vdagent. Default is on. 2318 2319 ``playback-compression=[on|off]`` 2320 Enable/disable audio stream compression (using celt 0.5.1). 2321 Default is on. 2322 2323 ``seamless-migration=[on|off]`` 2324 Enable/disable spice seamless migration. Default is off. 2325 2326 ``gl=[on|off]`` 2327 Enable/disable OpenGL context. Default is off. 2328 2329 ``rendernode=<file>`` 2330 DRM render node for OpenGL rendering. If not specified, it will 2331 pick the first available. (Since 2.9) 2332ERST 2333 2334DEF("portrait", 0, QEMU_OPTION_portrait, 2335 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 2336 QEMU_ARCH_ALL) 2337SRST 2338``-portrait`` 2339 Rotate graphical output 90 deg left (only PXA LCD). 2340ERST 2341 2342DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 2343 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 2344 QEMU_ARCH_ALL) 2345SRST 2346``-rotate deg`` 2347 Rotate graphical output some deg left (only PXA LCD). 2348ERST 2349 2350DEF("vga", HAS_ARG, QEMU_OPTION_vga, 2351 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 2352 " select video card type\n", QEMU_ARCH_ALL) 2353SRST 2354``-vga type`` 2355 Select type of VGA card to emulate. Valid values for type are 2356 2357 ``cirrus`` 2358 Cirrus Logic GD5446 Video card. All Windows versions starting 2359 from Windows 95 should recognize and use this graphic card. For 2360 optimal performances, use 16 bit color depth in the guest and 2361 the host OS. (This card was the default before QEMU 2.2) 2362 2363 ``std`` 2364 Standard VGA card with Bochs VBE extensions. If your guest OS 2365 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if 2366 you want to use high resolution modes (>= 1280x1024x16) then you 2367 should use this option. (This card is the default since QEMU 2368 2.2) 2369 2370 ``vmware`` 2371 VMWare SVGA-II compatible adapter. Use it if you have 2372 sufficiently recent XFree86/XOrg server or Windows guest with a 2373 driver for this card. 2374 2375 ``qxl`` 2376 QXL paravirtual graphic card. It is VGA compatible (including 2377 VESA 2.0 VBE support). Works best with qxl guest drivers 2378 installed though. Recommended choice when using the spice 2379 protocol. 2380 2381 ``tcx`` 2382 (sun4m only) Sun TCX framebuffer. This is the default 2383 framebuffer for sun4m machines and offers both 8-bit and 24-bit 2384 colour depths at a fixed resolution of 1024x768. 2385 2386 ``cg3`` 2387 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit 2388 framebuffer for sun4m machines available in both 1024x768 2389 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people 2390 wishing to run older Solaris versions. 2391 2392 ``virtio`` 2393 Virtio VGA card. 2394 2395 ``none`` 2396 Disable VGA card. 2397ERST 2398 2399DEF("full-screen", 0, QEMU_OPTION_full_screen, 2400 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 2401SRST 2402``-full-screen`` 2403 Start in full screen. 2404ERST 2405 2406DEF("g", HAS_ARG, QEMU_OPTION_g , 2407 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 2408 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 2409SRST 2410``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]`` 2411 Set the initial graphical resolution and depth (PPC, SPARC only). 2412 2413 For PPC the default is 800x600x32. 2414 2415 For SPARC with the TCX graphics device, the default is 1024x768x8 2416 with the option of 1024x768x24. For cgthree, the default is 2417 1024x768x8 with the option of 1152x900x8 for people who wish to use 2418 OBP. 2419ERST 2420 2421DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 2422 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 2423SRST 2424``-vnc display[,option[,option[,...]]]`` 2425 Normally, if QEMU is compiled with graphical window support, it 2426 displays output such as guest graphics, guest console, and the QEMU 2427 monitor in a window. With this option, you can have QEMU listen on 2428 VNC display display and redirect the VGA display over the VNC 2429 session. It is very useful to enable the usb tablet device when 2430 using this option (option ``-device usb-tablet``). When using the 2431 VNC display, you must use the ``-k`` parameter to set the keyboard 2432 layout if you are not using en-us. Valid syntax for the display is 2433 2434 ``to=L`` 2435 With this option, QEMU will try next available VNC displays, 2436 until the number L, if the origianlly defined "-vnc display" is 2437 not available, e.g. port 5900+display is already used by another 2438 application. By default, to=0. 2439 2440 ``host:d`` 2441 TCP connections will only be allowed from host on display d. By 2442 convention the TCP port is 5900+d. Optionally, host can be 2443 omitted in which case the server will accept connections from 2444 any host. 2445 2446 ``unix:path`` 2447 Connections will be allowed over UNIX domain sockets where path 2448 is the location of a unix socket to listen for connections on. 2449 2450 ``none`` 2451 VNC is initialized but not started. The monitor ``change`` 2452 command can be used to later start the VNC server. 2453 2454 Following the display value there may be one or more option flags 2455 separated by commas. Valid options are 2456 2457 ``reverse=on|off`` 2458 Connect to a listening VNC client via a "reverse" connection. 2459 The client is specified by the display. For reverse network 2460 connections (host:d,``reverse``), the d argument is a TCP port 2461 number, not a display number. 2462 2463 ``websocket=on|off`` 2464 Opens an additional TCP listening port dedicated to VNC 2465 Websocket connections. If a bare websocket option is given, the 2466 Websocket port is 5700+display. An alternative port can be 2467 specified with the syntax ``websocket``\ =port. 2468 2469 If host is specified connections will only be allowed from this 2470 host. It is possible to control the websocket listen address 2471 independently, using the syntax ``websocket``\ =host:port. 2472 2473 If no TLS credentials are provided, the websocket connection 2474 runs in unencrypted mode. If TLS credentials are provided, the 2475 websocket connection requires encrypted client connections. 2476 2477 ``password=on|off`` 2478 Require that password based authentication is used for client 2479 connections. 2480 2481 The password must be set separately using the ``set_password`` 2482 command in the :ref:`QEMU monitor`. The 2483 syntax to change your password is: 2484 ``set_password <protocol> <password>`` where <protocol> could be 2485 either "vnc" or "spice". 2486 2487 If you would like to change <protocol> password expiration, you 2488 should use ``expire_password <protocol> <expiration-time>`` 2489 where expiration time could be one of the following options: 2490 now, never, +seconds or UNIX time of expiration, e.g. +60 to 2491 make password expire in 60 seconds, or 1335196800 to make 2492 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for 2493 this date and time). 2494 2495 You can also use keywords "now" or "never" for the expiration 2496 time to allow <protocol> password to expire immediately or never 2497 expire. 2498 2499 ``password-secret=<secret-id>`` 2500 Require that password based authentication is used for client 2501 connections, using the password provided by the ``secret`` 2502 object identified by ``secret-id``. 2503 2504 ``tls-creds=ID`` 2505 Provides the ID of a set of TLS credentials to use to secure the 2506 VNC server. They will apply to both the normal VNC server socket 2507 and the websocket socket (if enabled). Setting TLS credentials 2508 will cause the VNC server socket to enable the VeNCrypt auth 2509 mechanism. The credentials should have been previously created 2510 using the ``-object tls-creds`` argument. 2511 2512 ``tls-authz=ID`` 2513 Provides the ID of the QAuthZ authorization object against which 2514 the client's x509 distinguished name will validated. This object 2515 is only resolved at time of use, so can be deleted and recreated 2516 on the fly while the VNC server is active. If missing, it will 2517 default to denying access. 2518 2519 ``sasl=on|off`` 2520 Require that the client use SASL to authenticate with the VNC 2521 server. The exact choice of authentication method used is 2522 controlled from the system / user's SASL configuration file for 2523 the 'qemu' service. This is typically found in 2524 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, 2525 an environment variable SASL\_CONF\_PATH can be used to make it 2526 search alternate locations for the service config. While some 2527 SASL auth methods can also provide data encryption (eg GSSAPI), 2528 it is recommended that SASL always be combined with the 'tls' 2529 and 'x509' settings to enable use of SSL and server 2530 certificates. This ensures a data encryption preventing 2531 compromise of authentication credentials. See the 2532 :ref:`VNC security` section in the System Emulation Users Guide 2533 for details on using SASL authentication. 2534 2535 ``sasl-authz=ID`` 2536 Provides the ID of the QAuthZ authorization object against which 2537 the client's SASL username will validated. This object is only 2538 resolved at time of use, so can be deleted and recreated on the 2539 fly while the VNC server is active. If missing, it will default 2540 to denying access. 2541 2542 ``acl=on|off`` 2543 Legacy method for enabling authorization of clients against the 2544 x509 distinguished name and SASL username. It results in the 2545 creation of two ``authz-list`` objects with IDs of 2546 ``vnc.username`` and ``vnc.x509dname``. The rules for these 2547 objects must be configured with the HMP ACL commands. 2548 2549 This option is deprecated and should no longer be used. The new 2550 ``sasl-authz`` and ``tls-authz`` options are a replacement. 2551 2552 ``lossy=on|off`` 2553 Enable lossy compression methods (gradient, JPEG, ...). If this 2554 option is set, VNC client may receive lossy framebuffer updates 2555 depending on its encoding settings. Enabling this option can 2556 save a lot of bandwidth at the expense of quality. 2557 2558 ``non-adaptive=on|off`` 2559 Disable adaptive encodings. Adaptive encodings are enabled by 2560 default. An adaptive encoding will try to detect frequently 2561 updated screen regions, and send updates in these regions using 2562 a lossy encoding (like JPEG). This can be really helpful to save 2563 bandwidth when playing videos. Disabling adaptive encodings 2564 restores the original static behavior of encodings like Tight. 2565 2566 ``share=[allow-exclusive|force-shared|ignore]`` 2567 Set display sharing policy. 'allow-exclusive' allows clients to 2568 ask for exclusive access. As suggested by the rfb spec this is 2569 implemented by dropping other connections. Connecting multiple 2570 clients in parallel requires all clients asking for a shared 2571 session (vncviewer: -shared switch). This is the default. 2572 'force-shared' disables exclusive client access. Useful for 2573 shared desktop sessions, where you don't want someone forgetting 2574 specify -shared disconnect everybody else. 'ignore' completely 2575 ignores the shared flag and allows everybody connect 2576 unconditionally. Doesn't conform to the rfb spec but is 2577 traditional QEMU behavior. 2578 2579 ``key-delay-ms`` 2580 Set keyboard delay, for key down and key up events, in 2581 milliseconds. Default is 10. Keyboards are low-bandwidth 2582 devices, so this slowdown can help the device and guest to keep 2583 up and not lose events in case events are arriving in bulk. 2584 Possible causes for the latter are flaky network connections, or 2585 scripts for automated testing. 2586 2587 ``audiodev=audiodev`` 2588 Use the specified audiodev when the VNC client requests audio 2589 transmission. When not using an -audiodev argument, this option 2590 must be omitted, otherwise is must be present and specify a 2591 valid audiodev. 2592 2593 ``power-control=on|off`` 2594 Permit the remote client to issue shutdown, reboot or reset power 2595 control requests. 2596ERST 2597 2598ARCHHEADING(, QEMU_ARCH_I386) 2599 2600ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2601 2602DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2603 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2604 QEMU_ARCH_I386) 2605SRST 2606``-win2k-hack`` 2607 Use it when installing Windows 2000 to avoid a disk full bug. After 2608 Windows 2000 is installed, you no longer need this option (this 2609 option slows down the IDE transfers). 2610ERST 2611 2612DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2613 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2614 QEMU_ARCH_I386) 2615SRST 2616``-no-fd-bootchk`` 2617 Disable boot signature checking for floppy disks in BIOS. May be 2618 needed to boot from old floppy disks. 2619ERST 2620 2621DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2622 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2623SRST 2624``-no-acpi`` 2625 Disable ACPI (Advanced Configuration and Power Interface) support. 2626 Use it if your guest OS complains about ACPI problems (PC target 2627 machine only). 2628ERST 2629 2630DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2631 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2632SRST 2633``-no-hpet`` 2634 Disable HPET support. Deprecated, use '-machine hpet=off' instead. 2635ERST 2636 2637DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2638 "-acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n][,asl_compiler_id=str][,asl_compiler_rev=n][,{data|file}=file1[:file2]...]\n" 2639 " ACPI table description\n", QEMU_ARCH_I386) 2640SRST 2641``-acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n] [,asl_compiler_id=str][,asl_compiler_rev=n][,data=file1[:file2]...]`` 2642 Add ACPI table with specified header fields and context from 2643 specified files. For file=, take whole ACPI table from the specified 2644 files, including all ACPI headers (possible overridden by other 2645 options). For data=, only data portion of the table is used, all 2646 header information is specified in the command line. If a SLIC table 2647 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id 2648 fields will override the same in the RSDT and the FADT (a.k.a. 2649 FACP), in order to ensure the field matches required by the 2650 Microsoft SLIC spec and the ACPI spec. 2651ERST 2652 2653DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2654 "-smbios file=binary\n" 2655 " load SMBIOS entry from binary file\n" 2656 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2657 " [,uefi=on|off]\n" 2658 " specify SMBIOS type 0 fields\n" 2659 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2660 " [,uuid=uuid][,sku=str][,family=str]\n" 2661 " specify SMBIOS type 1 fields\n" 2662 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2663 " [,asset=str][,location=str]\n" 2664 " specify SMBIOS type 2 fields\n" 2665 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2666 " [,sku=str]\n" 2667 " specify SMBIOS type 3 fields\n" 2668 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2669 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n" 2670 " [,processor-id=%d]\n" 2671 " specify SMBIOS type 4 fields\n" 2672 "-smbios type=8[,external_reference=str][,internal_reference=str][,connector_type=%d][,port_type=%d]\n" 2673 " specify SMBIOS type 8 fields\n" 2674 "-smbios type=11[,value=str][,path=filename]\n" 2675 " specify SMBIOS type 11 fields\n" 2676 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2677 " [,asset=str][,part=str][,speed=%d]\n" 2678 " specify SMBIOS type 17 fields\n" 2679 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n" 2680 " specify SMBIOS type 41 fields\n", 2681 QEMU_ARCH_I386 | QEMU_ARCH_ARM | QEMU_ARCH_LOONGARCH) 2682SRST 2683``-smbios file=binary`` 2684 Load SMBIOS entry from binary file. 2685 2686``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]`` 2687 Specify SMBIOS type 0 fields 2688 2689``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]`` 2690 Specify SMBIOS type 1 fields 2691 2692``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]`` 2693 Specify SMBIOS type 2 fields 2694 2695``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]`` 2696 Specify SMBIOS type 3 fields 2697 2698``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str][,processor-id=%d]`` 2699 Specify SMBIOS type 4 fields 2700 2701``-smbios type=11[,value=str][,path=filename]`` 2702 Specify SMBIOS type 11 fields 2703 2704 This argument can be repeated multiple times, and values are added in the order they are parsed. 2705 Applications intending to use OEM strings data are encouraged to use their application name as 2706 a prefix for the value string. This facilitates passing information for multiple applications 2707 concurrently. 2708 2709 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax 2710 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes. 2711 2712 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to 2713 the SMBIOS table in the order in which they appear. 2714 2715 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535 2716 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the 2717 guest. Instead it should be used as a indicator to inform the guest where to locate the real 2718 data set, for example, by specifying the serial ID of a block device. 2719 2720 An example passing three strings is 2721 2722 .. parsed-literal:: 2723 2724 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\ 2725 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\ 2726 path=/some/file/with/oemstringsdata.txt 2727 2728 In the guest OS this is visible with the ``dmidecode`` command 2729 2730 .. parsed-literal:: 2731 2732 $ dmidecode -t 11 2733 Handle 0x0E00, DMI type 11, 5 bytes 2734 OEM Strings 2735 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/ 2736 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os 2737 String 3: myapp:some extra data 2738 2739 2740``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]`` 2741 Specify SMBIOS type 17 fields 2742 2743``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]`` 2744 Specify SMBIOS type 41 fields 2745 2746 This argument can be repeated multiple times. Its main use is to allow network interfaces be created 2747 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface 2748 position on the PCI bus. 2749 2750 Here is an example of use: 2751 2752 .. parsed-literal:: 2753 2754 -netdev user,id=internet \\ 2755 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\ 2756 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev 2757 2758 In the guest OS, the device should then appear as ``eno1``: 2759 2760 ..parsed-literal:: 2761 2762 $ ip -brief l 2763 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP> 2764 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP> 2765 2766 Currently, the PCI device has to be attached to the root bus. 2767 2768ERST 2769 2770DEFHEADING() 2771 2772DEFHEADING(Network options:) 2773 2774DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2775#ifdef CONFIG_SLIRP 2776 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n" 2777 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2778 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2779 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2780 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2781#ifndef _WIN32 2782 "[,smb=dir[,smbserver=addr]]\n" 2783#endif 2784 " configure a user mode network backend with ID 'str',\n" 2785 " its DHCP server and optional services\n" 2786#endif 2787#ifdef _WIN32 2788 "-netdev tap,id=str,ifname=name\n" 2789 " configure a host TAP network backend with ID 'str'\n" 2790#else 2791 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2792 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2793 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2794 " [,poll-us=n]\n" 2795 " configure a host TAP network backend with ID 'str'\n" 2796 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2797 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2798 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2799 " to deconfigure it\n" 2800 " use '[down]script=no' to disable script execution\n" 2801 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2802 " configure it\n" 2803 " use 'fd=h' to connect to an already opened TAP interface\n" 2804 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2805 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2806 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2807 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2808 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2809 " use vhost=on to enable experimental in kernel accelerator\n" 2810 " (only has effect for virtio guests which use MSIX)\n" 2811 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2812 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2813 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2814 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2815 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n" 2816 " spent on busy polling for vhost net\n" 2817 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2818 " configure a host TAP network backend with ID 'str' that is\n" 2819 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2820 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2821#endif 2822#ifdef __linux__ 2823 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2824 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n" 2825 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n" 2826 " [,rxcookie=rxcookie][,offset=offset]\n" 2827 " configure a network backend with ID 'str' connected to\n" 2828 " an Ethernet over L2TPv3 pseudowire.\n" 2829 " Linux kernel 3.3+ as well as most routers can talk\n" 2830 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2831 " VM to a router and even VM to Host. It is a nearly-universal\n" 2832 " standard (RFC3931). Note - this implementation uses static\n" 2833 " pre-configured tunnels (same as the Linux kernel).\n" 2834 " use 'src=' to specify source address\n" 2835 " use 'dst=' to specify destination address\n" 2836 " use 'udp=on' to specify udp encapsulation\n" 2837 " use 'srcport=' to specify source udp port\n" 2838 " use 'dstport=' to specify destination udp port\n" 2839 " use 'ipv6=on' to force v6\n" 2840 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2841 " well as a weak security measure\n" 2842 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2843 " use 'txcookie=0x012345678' to specify a txcookie\n" 2844 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2845 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2846 " use 'pincounter=on' to work around broken counter handling in peer\n" 2847 " use 'offset=X' to add an extra offset between header and data\n" 2848#endif 2849 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2850 " configure a network backend to connect to another network\n" 2851 " using a socket connection\n" 2852 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2853 " configure a network backend to connect to a multicast maddr and port\n" 2854 " use 'localaddr=addr' to specify the host address to send packets from\n" 2855 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2856 " configure a network backend to connect to another network\n" 2857 " using an UDP tunnel\n" 2858 "-netdev stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port[,to=maxport][,numeric=on|off][,keep-alive=on|off][,mptcp=on|off][,addr.ipv4=on|off][,addr.ipv6=on|off][,reconnect=seconds]\n" 2859 "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect=seconds]\n" 2860 "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect=seconds]\n" 2861 " configure a network backend to connect to another network\n" 2862 " using a socket connection in stream mode.\n" 2863 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n" 2864 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]\n" 2865 " configure a network backend to connect to a multicast maddr and port\n" 2866 " use ``local.host=addr`` to specify the host address to send packets from\n" 2867 "-netdev dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]\n" 2868 "-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]\n" 2869 "-netdev dgram,id=str,local.type=fd,local.str=file-descriptor\n" 2870 " configure a network backend to connect to another network\n" 2871 " using an UDP tunnel\n" 2872#ifdef CONFIG_VDE 2873 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2874 " configure a network backend to connect to port 'n' of a vde switch\n" 2875 " running on host and listening for incoming connections on 'socketpath'.\n" 2876 " Use group 'groupname' and mode 'octalmode' to change default\n" 2877 " ownership and permissions for communication port.\n" 2878#endif 2879#ifdef CONFIG_NETMAP 2880 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2881 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2882 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2883 " netmap device, defaults to '/dev/netmap')\n" 2884#endif 2885#ifdef CONFIG_POSIX 2886 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2887 " configure a vhost-user network, backed by a chardev 'dev'\n" 2888#endif 2889#ifdef __linux__ 2890 "-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n" 2891 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n" 2892 " use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n" 2893 " use 'vhostfd=h' to connect to an already opened vhost vdpa device\n" 2894#endif 2895#ifdef CONFIG_VMNET 2896 "-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n" 2897 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2898 " configure a vmnet network backend in host mode with ID 'str',\n" 2899 " isolate this interface from others with 'isolated',\n" 2900 " configure the address range and choose a subnet mask,\n" 2901 " specify network UUID 'uuid' to disable DHCP and interact with\n" 2902 " vmnet-host interfaces within this isolated network\n" 2903 "-netdev vmnet-shared,id=str[,isolated=on|off][,nat66-prefix=addr]\n" 2904 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2905 " configure a vmnet network backend in shared mode with ID 'str',\n" 2906 " configure the address range and choose a subnet mask,\n" 2907 " set IPv6 ULA prefix (of length 64) to use for internal network,\n" 2908 " isolate this interface from others with 'isolated'\n" 2909 "-netdev vmnet-bridged,id=str,ifname=name[,isolated=on|off]\n" 2910 " configure a vmnet network backend in bridged mode with ID 'str',\n" 2911 " use 'ifname=name' to select a physical network interface to be bridged,\n" 2912 " isolate this interface from others with 'isolated'\n" 2913#endif 2914 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2915 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2916DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2917 "-nic [tap|bridge|" 2918#ifdef CONFIG_SLIRP 2919 "user|" 2920#endif 2921#ifdef __linux__ 2922 "l2tpv3|" 2923#endif 2924#ifdef CONFIG_VDE 2925 "vde|" 2926#endif 2927#ifdef CONFIG_NETMAP 2928 "netmap|" 2929#endif 2930#ifdef CONFIG_POSIX 2931 "vhost-user|" 2932#endif 2933#ifdef CONFIG_VMNET 2934 "vmnet-host|vmnet-shared|vmnet-bridged|" 2935#endif 2936 "socket][,option][,...][mac=macaddr]\n" 2937 " initialize an on-board / default host NIC (using MAC address\n" 2938 " macaddr) and connect it to the given host network backend\n" 2939 "-nic none use it alone to have zero network devices (the default is to\n" 2940 " provided a 'user' network connection)\n", 2941 QEMU_ARCH_ALL) 2942DEF("net", HAS_ARG, QEMU_OPTION_net, 2943 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2944 " configure or create an on-board (or machine default) NIC and\n" 2945 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2946 "-net [" 2947#ifdef CONFIG_SLIRP 2948 "user|" 2949#endif 2950 "tap|" 2951 "bridge|" 2952#ifdef CONFIG_VDE 2953 "vde|" 2954#endif 2955#ifdef CONFIG_NETMAP 2956 "netmap|" 2957#endif 2958#ifdef CONFIG_VMNET 2959 "vmnet-host|vmnet-shared|vmnet-bridged|" 2960#endif 2961 "socket][,option][,option][,...]\n" 2962 " old way to initialize a host network interface\n" 2963 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2964SRST 2965``-nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]`` 2966 This option is a shortcut for configuring both the on-board 2967 (default) guest NIC hardware and the host network backend in one go. 2968 The host backend options are the same as with the corresponding 2969 ``-netdev`` options below. The guest NIC model can be set with 2970 ``model=modelname``. Use ``model=help`` to list the available device 2971 types. The hardware MAC address can be set with ``mac=macaddr``. 2972 2973 The following two example do exactly the same, to show how ``-nic`` 2974 can be used to shorten the command line length: 2975 2976 .. parsed-literal:: 2977 2978 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2979 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2980 2981``-nic none`` 2982 Indicate that no network devices should be configured. It is used to 2983 override the default configuration (default NIC with "user" host 2984 network backend) which is activated if no other networking options 2985 are provided. 2986 2987``-netdev user,id=id[,option][,option][,...]`` 2988 Configure user mode host network backend which requires no 2989 administrator privilege to run. Valid options are: 2990 2991 ``id=id`` 2992 Assign symbolic name for use in monitor commands. 2993 2994 ``ipv4=on|off and ipv6=on|off`` 2995 Specify that either IPv4 or IPv6 must be enabled. If neither is 2996 specified both protocols are enabled. 2997 2998 ``net=addr[/mask]`` 2999 Set IP network address the guest will see. Optionally specify 3000 the netmask, either in the form a.b.c.d or as number of valid 3001 top-most bits. Default is 10.0.2.0/24. 3002 3003 ``host=addr`` 3004 Specify the guest-visible address of the host. Default is the 3005 2nd IP in the guest network, i.e. x.x.x.2. 3006 3007 ``ipv6-net=addr[/int]`` 3008 Set IPv6 network address the guest will see (default is 3009 fec0::/64). The network prefix is given in the usual hexadecimal 3010 IPv6 address notation. The prefix size is optional, and is given 3011 as the number of valid top-most bits (default is 64). 3012 3013 ``ipv6-host=addr`` 3014 Specify the guest-visible IPv6 address of the host. Default is 3015 the 2nd IPv6 in the guest network, i.e. xxxx::2. 3016 3017 ``restrict=on|off`` 3018 If this option is enabled, the guest will be isolated, i.e. it 3019 will not be able to contact the host and no guest IP packets 3020 will be routed over the host to the outside. This option does 3021 not affect any explicitly set forwarding rules. 3022 3023 ``hostname=name`` 3024 Specifies the client hostname reported by the built-in DHCP 3025 server. 3026 3027 ``dhcpstart=addr`` 3028 Specify the first of the 16 IPs the built-in DHCP server can 3029 assign. Default is the 15th to 31st IP in the guest network, 3030 i.e. x.x.x.15 to x.x.x.31. 3031 3032 ``dns=addr`` 3033 Specify the guest-visible address of the virtual nameserver. The 3034 address must be different from the host address. Default is the 3035 3rd IP in the guest network, i.e. x.x.x.3. 3036 3037 ``ipv6-dns=addr`` 3038 Specify the guest-visible address of the IPv6 virtual 3039 nameserver. The address must be different from the host address. 3040 Default is the 3rd IP in the guest network, i.e. xxxx::3. 3041 3042 ``dnssearch=domain`` 3043 Provides an entry for the domain-search list sent by the 3044 built-in DHCP server. More than one domain suffix can be 3045 transmitted by specifying this option multiple times. If 3046 supported, this will cause the guest to automatically try to 3047 append the given domain suffix(es) in case a domain name can not 3048 be resolved. 3049 3050 Example: 3051 3052 .. parsed-literal:: 3053 3054 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 3055 3056 ``domainname=domain`` 3057 Specifies the client domain name reported by the built-in DHCP 3058 server. 3059 3060 ``tftp=dir`` 3061 When using the user mode network stack, activate a built-in TFTP 3062 server. The files in dir will be exposed as the root of a TFTP 3063 server. The TFTP client on the guest must be configured in 3064 binary mode (use the command ``bin`` of the Unix TFTP client). 3065 3066 ``tftp-server-name=name`` 3067 In BOOTP reply, broadcast name as the "TFTP server name" 3068 (RFC2132 option 66). This can be used to advise the guest to 3069 load boot files or configurations from a different server than 3070 the host address. 3071 3072 ``bootfile=file`` 3073 When using the user mode network stack, broadcast file as the 3074 BOOTP filename. In conjunction with ``tftp``, this can be used 3075 to network boot a guest from a local directory. 3076 3077 Example (using pxelinux): 3078 3079 .. parsed-literal:: 3080 3081 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\ 3082 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 3083 3084 ``smb=dir[,smbserver=addr]`` 3085 When using the user mode network stack, activate a built-in SMB 3086 server so that Windows OSes can access to the host files in 3087 ``dir`` transparently. The IP address of the SMB server can be 3088 set to addr. By default the 4th IP in the guest network is used, 3089 i.e. x.x.x.4. 3090 3091 In the guest Windows OS, the line: 3092 3093 :: 3094 3095 10.0.2.4 smbserver 3096 3097 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows 3098 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows 3099 NT/2000). 3100 3101 Then ``dir`` can be accessed in ``\\smbserver\qemu``. 3102 3103 Note that a SAMBA server must be installed on the host OS. 3104 3105 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport`` 3106 Redirect incoming TCP or UDP connections to the host port 3107 hostport to the guest IP address guestaddr on guest port 3108 guestport. If guestaddr is not specified, its value is x.x.x.15 3109 (default first address given by the built-in DHCP server). By 3110 specifying hostaddr, the rule can be bound to a specific host 3111 interface. If no connection type is set, TCP is used. This 3112 option can be given multiple times. 3113 3114 For example, to redirect host X11 connection from screen 1 to 3115 guest screen 0, use the following: 3116 3117 .. parsed-literal:: 3118 3119 # on the host 3120 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 3121 # this host xterm should open in the guest X11 server 3122 xterm -display :1 3123 3124 To redirect telnet connections from host port 5555 to telnet 3125 port on the guest, use the following: 3126 3127 .. parsed-literal:: 3128 3129 # on the host 3130 |qemu_system| -nic user,hostfwd=tcp::5555-:23 3131 telnet localhost 5555 3132 3133 Then when you use on the host ``telnet localhost 5555``, you 3134 connect to the guest telnet server. 3135 3136 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command`` 3137 Forward guest TCP connections to the IP address server on port 3138 port to the character device dev or to a program executed by 3139 cmd:command which gets spawned for each connection. This option 3140 can be given multiple times. 3141 3142 You can either use a chardev directly and have that one used 3143 throughout QEMU's lifetime, like in the following example: 3144 3145 .. parsed-literal:: 3146 3147 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 3148 # the guest accesses it 3149 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 3150 3151 Or you can execute a command on every TCP connection established 3152 by the guest, so that QEMU behaves similar to an inetd process 3153 for that virtual server: 3154 3155 .. parsed-literal:: 3156 3157 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 3158 # and connect the TCP stream to its stdin/stdout 3159 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 3160 3161``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` 3162 Configure a host TAP network backend with ID id. 3163 3164 Use the network script file to configure it and the network script 3165 dfile to deconfigure it. If name is not provided, the OS 3166 automatically provides one. The default network configure script is 3167 ``/etc/qemu-ifup`` and the default network deconfigure script is 3168 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to 3169 disable script execution. 3170 3171 If running QEMU as an unprivileged user, use the network helper 3172 to configure the TAP interface and attach it to the bridge. 3173 The default network helper executable is 3174 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3175 ``br0``. 3176 3177 ``fd``\ =h can be used to specify the handle of an already opened 3178 host TAP interface. 3179 3180 Examples: 3181 3182 .. parsed-literal:: 3183 3184 #launch a QEMU instance with the default network script 3185 |qemu_system| linux.img -nic tap 3186 3187 .. parsed-literal:: 3188 3189 #launch a QEMU instance with two NICs, each one connected 3190 #to a TAP device 3191 |qemu_system| linux.img \\ 3192 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\ 3193 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 3194 3195 .. parsed-literal:: 3196 3197 #launch a QEMU instance with the default network helper to 3198 #connect a TAP device to bridge br0 3199 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3200 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 3201 3202``-netdev bridge,id=id[,br=bridge][,helper=helper]`` 3203 Connect a host TAP network interface to a host bridge device. 3204 3205 Use the network helper helper to configure the TAP interface and 3206 attach it to the bridge. The default network helper executable is 3207 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3208 ``br0``. 3209 3210 Examples: 3211 3212 .. parsed-literal:: 3213 3214 #launch a QEMU instance with the default network helper to 3215 #connect a TAP device to bridge br0 3216 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 3217 3218 .. parsed-literal:: 3219 3220 #launch a QEMU instance with the default network helper to 3221 #connect a TAP device to bridge qemubr0 3222 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 3223 3224``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]`` 3225 This host network backend can be used to connect the guest's network 3226 to another QEMU virtual machine using a TCP socket connection. If 3227 ``listen`` is specified, QEMU waits for incoming connections on port 3228 (host is optional). ``connect`` is used to connect to another QEMU 3229 instance using the ``listen`` option. ``fd``\ =h specifies an 3230 already opened TCP socket. 3231 3232 Example: 3233 3234 .. parsed-literal:: 3235 3236 # launch a first QEMU instance 3237 |qemu_system| linux.img \\ 3238 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3239 -netdev socket,id=n1,listen=:1234 3240 # connect the network of this instance to the network of the first instance 3241 |qemu_system| linux.img \\ 3242 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3243 -netdev socket,id=n2,connect=127.0.0.1:1234 3244 3245``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]`` 3246 Configure a socket host network backend to share the guest's network 3247 traffic with another QEMU virtual machines using a UDP multicast 3248 socket, effectively making a bus for every QEMU with same multicast 3249 address maddr and port. NOTES: 3250 3251 1. Several QEMU can be running on different hosts and share same bus 3252 (assuming correct multicast setup for these hosts). 3253 3254 2. mcast support is compatible with User Mode Linux (argument 3255 ``ethN=mcast``), see http://user-mode-linux.sf.net. 3256 3257 3. Use ``fd=h`` to specify an already opened UDP multicast socket. 3258 3259 Example: 3260 3261 .. parsed-literal:: 3262 3263 # launch one QEMU instance 3264 |qemu_system| linux.img \\ 3265 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3266 -netdev socket,id=n1,mcast=230.0.0.1:1234 3267 # launch another QEMU instance on same "bus" 3268 |qemu_system| linux.img \\ 3269 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3270 -netdev socket,id=n2,mcast=230.0.0.1:1234 3271 # launch yet another QEMU instance on same "bus" 3272 |qemu_system| linux.img \\ 3273 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\ 3274 -netdev socket,id=n3,mcast=230.0.0.1:1234 3275 3276 Example (User Mode Linux compat.): 3277 3278 .. parsed-literal:: 3279 3280 # launch QEMU instance (note mcast address selected is UML's default) 3281 |qemu_system| linux.img \\ 3282 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3283 -netdev socket,id=n1,mcast=239.192.168.1:1102 3284 # launch UML 3285 /path/to/linux ubd0=/path/to/root_fs eth0=mcast 3286 3287 Example (send packets from host's 1.2.3.4): 3288 3289 .. parsed-literal:: 3290 3291 |qemu_system| linux.img \\ 3292 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3293 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 3294 3295``-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]`` 3296 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931) 3297 is a popular protocol to transport Ethernet (and other Layer 2) data 3298 frames between two systems. It is present in routers, firewalls and 3299 the Linux kernel (from version 3.3 onwards). 3300 3301 This transport allows a VM to communicate to another VM, router or 3302 firewall directly. 3303 3304 ``src=srcaddr`` 3305 source address (mandatory) 3306 3307 ``dst=dstaddr`` 3308 destination address (mandatory) 3309 3310 ``udp`` 3311 select udp encapsulation (default is ip). 3312 3313 ``srcport=srcport`` 3314 source udp port. 3315 3316 ``dstport=dstport`` 3317 destination udp port. 3318 3319 ``ipv6`` 3320 force v6, otherwise defaults to v4. 3321 3322 ``rxcookie=rxcookie``; \ ``txcookie=txcookie`` 3323 Cookies are a weak form of security in the l2tpv3 specification. 3324 Their function is mostly to prevent misconfiguration. By default 3325 they are 32 bit. 3326 3327 ``cookie64`` 3328 Set cookie size to 64 bit instead of the default 32 3329 3330 ``counter=off`` 3331 Force a 'cut-down' L2TPv3 with no counter as in 3332 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 3333 3334 ``pincounter=on`` 3335 Work around broken counter handling in peer. This may also help 3336 on networks which have packet reorder. 3337 3338 ``offset=offset`` 3339 Add an extra offset between header and data 3340 3341 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to 3342 the bridge br-lan on the remote Linux host 1.2.3.4: 3343 3344 .. parsed-literal:: 3345 3346 # Setup tunnel on linux host using raw ip as encapsulation 3347 # on 1.2.3.4 3348 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\ 3349 encap udp udp_sport 16384 udp_dport 16384 3350 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\ 3351 0xFFFFFFFF peer_session_id 0xFFFFFFFF 3352 ifconfig vmtunnel0 mtu 1500 3353 ifconfig vmtunnel0 up 3354 brctl addif br-lan vmtunnel0 3355 3356 3357 # on 4.3.2.1 3358 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 3359 3360 |qemu_system| linux.img -device e1000,netdev=n1 \\ 3361 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 3362 3363``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]`` 3364 Configure VDE backend to connect to PORT n of a vde switch running 3365 on host and listening for incoming connections on socketpath. Use 3366 GROUP groupname and MODE octalmode to change default ownership and 3367 permissions for communication port. This option is only available if 3368 QEMU has been compiled with vde support enabled. 3369 3370 Example: 3371 3372 .. parsed-literal:: 3373 3374 # launch vde switch 3375 vde_switch -F -sock /tmp/myswitch 3376 # launch QEMU instance 3377 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch 3378 3379``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` 3380 Establish a vhost-user netdev, backed by a chardev id. The chardev 3381 should be a unix domain socket backed one. The vhost-user uses a 3382 specifically defined protocol to pass vhost ioctl replacement 3383 messages to an application on the other end of the socket. On 3384 non-MSIX guests, the feature can be forced with vhostforce. Use 3385 'queues=n' to specify the number of queues to be created for 3386 multiqueue vhost-user. 3387 3388 Example: 3389 3390 :: 3391 3392 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 3393 -numa node,memdev=mem \ 3394 -chardev socket,id=chr0,path=/path/to/socket \ 3395 -netdev type=vhost-user,id=net0,chardev=chr0 \ 3396 -device virtio-net-pci,netdev=net0 3397 3398``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]`` 3399 Establish a vhost-vdpa netdev. 3400 3401 vDPA device is a device that uses a datapath which complies with 3402 the virtio specifications with a vendor specific control path. 3403 vDPA devices can be both physically located on the hardware or 3404 emulated by software. 3405 3406``-netdev hubport,id=id,hubid=hubid[,netdev=nd]`` 3407 Create a hub port on the emulated hub with ID hubid. 3408 3409 The hubport netdev lets you connect a NIC to a QEMU emulated hub 3410 instead of a single netdev. Alternatively, you can also connect the 3411 hubport to another netdev with ID nd by using the ``netdev=nd`` 3412 option. 3413 3414``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]`` 3415 Legacy option to configure or create an on-board (or machine 3416 default) Network Interface Card(NIC) and connect it either to the 3417 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd. 3418 If model is omitted, then the default NIC model associated with the 3419 machine type is used. Note that the default NIC model may change in 3420 future QEMU releases, so it is highly recommended to always specify 3421 a model. Optionally, the MAC address can be changed to mac, the 3422 device address set to addr (PCI cards only), and a name can be 3423 assigned for use in monitor commands. Optionally, for PCI cards, you 3424 can specify the number v of MSI-X vectors that the card should have; 3425 this option currently only affects virtio cards; set v = 0 to 3426 disable MSI-X. If no ``-net`` option is specified, a single NIC is 3427 created. QEMU can emulate several different models of network card. 3428 Use ``-net nic,model=help`` for a list of available devices for your 3429 target. 3430 3431``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]`` 3432 Configure a host network backend (with the options corresponding to 3433 the same ``-netdev`` option) and connect it to the emulated hub 0 3434 (the default hub). Use name to specify the name of the hub port. 3435ERST 3436 3437DEFHEADING() 3438 3439DEFHEADING(Character device options:) 3440 3441DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 3442 "-chardev help\n" 3443 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3444 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n" 3445 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" 3446 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 3447 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" 3448 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" 3449 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 3450 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n" 3451 " [,logfile=PATH][,logappend=on|off]\n" 3452 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3453 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 3454 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3455 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 3456 "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3457 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3458#ifdef _WIN32 3459 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3460 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3461#else 3462 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3463 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 3464#endif 3465#ifdef CONFIG_BRLAPI 3466 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3467#endif 3468#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 3469 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 3470 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3471#endif 3472#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 3473 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3474#endif 3475#if defined(CONFIG_SPICE) 3476 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3477 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3478#endif 3479 , QEMU_ARCH_ALL 3480) 3481 3482SRST 3483The general form of a character device option is: 3484 3485``-chardev backend,id=id[,mux=on|off][,options]`` 3486 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, 3487 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, 3488 ``pty``, ``stdio``, ``braille``, ``parallel``, 3489 ``spicevmc``, ``spiceport``. The specific backend will determine the 3490 applicable options. 3491 3492 Use ``-chardev help`` to print all available chardev backend types. 3493 3494 All devices must have an id, which can be any string up to 127 3495 characters long. It is used to uniquely identify this device in 3496 other command line directives. 3497 3498 A character device may be used in multiplexing mode by multiple 3499 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is 3500 a "1:N" device, and here the "1" end is your specified chardev 3501 backend, and the "N" end is the various parts of QEMU that can talk 3502 to a chardev. If you create a chardev with ``id=myid`` and 3503 ``mux=on``, QEMU will create a multiplexer with your specified ID, 3504 and you can then configure multiple front ends to use that chardev 3505 ID for their input/output. Up to four different front ends can be 3506 connected to a single multiplexed chardev. (Without multiplexing 3507 enabled, a chardev can only be used by a single front end.) For 3508 instance you could use this to allow a single stdio chardev to be 3509 used by two serial ports and the QEMU monitor: 3510 3511 :: 3512 3513 -chardev stdio,mux=on,id=char0 \ 3514 -mon chardev=char0,mode=readline \ 3515 -serial chardev:char0 \ 3516 -serial chardev:char0 3517 3518 You can have more than one multiplexer in a system configuration; 3519 for instance you could have a TCP port multiplexed between UART 0 3520 and UART 1, and stdio multiplexed between the QEMU monitor and a 3521 parallel port: 3522 3523 :: 3524 3525 -chardev stdio,mux=on,id=char0 \ 3526 -mon chardev=char0,mode=readline \ 3527 -parallel chardev:char0 \ 3528 -chardev tcp,...,mux=on,id=char1 \ 3529 -serial chardev:char1 \ 3530 -serial chardev:char1 3531 3532 When you're using a multiplexed character device, some escape 3533 sequences are interpreted in the input. See the chapter about 3534 :ref:`keys in the character backend multiplexer` in the 3535 System Emulation Users Guide for more details. 3536 3537 Note that some other command line options may implicitly create 3538 multiplexed character backends; for instance ``-serial mon:stdio`` 3539 creates a multiplexed stdio backend connected to the serial port and 3540 the QEMU monitor, and ``-nographic`` also multiplexes the console 3541 and the monitor to stdio. 3542 3543 There is currently no support for multiplexing in the other 3544 direction (where a single QEMU front end takes input and output from 3545 multiple chardevs). 3546 3547 Every backend supports the ``logfile`` option, which supplies the 3548 path to a file to record all data transmitted via the backend. The 3549 ``logappend`` option controls whether the log file will be truncated 3550 or appended to when opened. 3551 3552The available backends are: 3553 3554``-chardev null,id=id`` 3555 A void device. This device will not emit any data, and will drop any 3556 data it receives. The null backend does not take any options. 3557 3558``-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]`` 3559 Create a two-way stream socket, which can be either a TCP or a unix 3560 socket. A unix socket will be created if ``path`` is specified. 3561 Behaviour is undefined if TCP options are specified for a unix 3562 socket. 3563 3564 ``server=on|off`` specifies that the socket shall be a listening socket. 3565 3566 ``wait=on|off`` specifies that QEMU should not block waiting for a client 3567 to connect to a listening socket. 3568 3569 ``telnet=on|off`` specifies that traffic on the socket should interpret 3570 telnet escape sequences. 3571 3572 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for 3573 communication. 3574 3575 ``reconnect`` sets the timeout for reconnecting on non-server 3576 sockets when the remote end goes away. qemu will delay this many 3577 seconds and then attempt to reconnect. Zero disables reconnecting, 3578 and is the default. 3579 3580 ``tls-creds`` requests enablement of the TLS protocol for 3581 encryption, and specifies the id of the TLS credentials to use for 3582 the handshake. The credentials must be previously created with the 3583 ``-object tls-creds`` argument. 3584 3585 ``tls-auth`` provides the ID of the QAuthZ authorization object 3586 against which the client's x509 distinguished name will be 3587 validated. This object is only resolved at time of use, so can be 3588 deleted and recreated on the fly while the chardev server is active. 3589 If missing, it will default to denying access. 3590 3591 TCP and unix socket options are given below: 3592 3593 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]`` 3594 ``host`` for a listening socket specifies the local address to 3595 be bound. For a connecting socket species the remote host to 3596 connect to. ``host`` is optional for listening sockets. If not 3597 specified it defaults to ``0.0.0.0``. 3598 3599 ``port`` for a listening socket specifies the local port to be 3600 bound. For a connecting socket specifies the port on the remote 3601 host to connect to. ``port`` can be given as either a port 3602 number or a service name. ``port`` is required. 3603 3604 ``to`` is only relevant to listening sockets. If it is 3605 specified, and ``port`` cannot be bound, QEMU will attempt to 3606 bind to subsequent ports up to and including ``to`` until it 3607 succeeds. ``to`` must be specified as a port number. 3608 3609 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 3610 or IPv6 must be used. If neither is specified the socket may 3611 use either protocol. 3612 3613 ``nodelay=on|off`` disables the Nagle algorithm. 3614 3615 ``unix options: path=path[,abstract=on|off][,tight=on|off]`` 3616 ``path`` specifies the local path of the unix socket. ``path`` 3617 is required. 3618 ``abstract=on|off`` specifies the use of the abstract socket namespace, 3619 rather than the filesystem. Optional, defaults to false. 3620 ``tight=on|off`` sets the socket length of abstract sockets to their minimum, 3621 rather than the full sun_path length. Optional, defaults to true. 3622 3623``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4=on|off][,ipv6=on|off]`` 3624 Sends all traffic from the guest to a remote host over UDP. 3625 3626 ``host`` specifies the remote host to connect to. If not specified 3627 it defaults to ``localhost``. 3628 3629 ``port`` specifies the port on the remote host to connect to. 3630 ``port`` is required. 3631 3632 ``localaddr`` specifies the local address to bind to. If not 3633 specified it defaults to ``0.0.0.0``. 3634 3635 ``localport`` specifies the local port to bind to. If not specified 3636 any available local port will be used. 3637 3638 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used. 3639 If neither is specified the device may use either protocol. 3640 3641``-chardev msmouse,id=id`` 3642 Forward QEMU's emulated msmouse events to the guest. ``msmouse`` 3643 does not take any options. 3644 3645``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` 3646 Connect to a QEMU text console. ``vc`` may optionally be given a 3647 specific size. 3648 3649 ``width`` and ``height`` specify the width and height respectively 3650 of the console, in pixels. 3651 3652 ``cols`` and ``rows`` specify that the console be sized to fit a 3653 text console with the given dimensions. 3654 3655``-chardev ringbuf,id=id[,size=size]`` 3656 Create a ring buffer with fixed size ``size``. size must be a power 3657 of two and defaults to ``64K``. 3658 3659``-chardev file,id=id,path=path[,input-path=input-path]`` 3660 Log all traffic received from the guest to a file. 3661 3662 ``path`` specifies the path of the file to be opened. This file will 3663 be created if it does not already exist, and overwritten if it does. 3664 ``path`` is required. 3665 3666 If ``input-path`` is specified, this is the path of a second file 3667 which will be used for input. If ``input-path`` is not specified, 3668 no input will be available from the chardev. 3669 3670 Note that ``input-path`` is not supported on Windows hosts. 3671 3672``-chardev pipe,id=id,path=path`` 3673 Create a two-way connection to the guest. The behaviour differs 3674 slightly between Windows hosts and other hosts: 3675 3676 On Windows, a single duplex pipe will be created at 3677 ``\\.pipe\path``. 3678 3679 On other hosts, 2 pipes will be created called ``path.in`` and 3680 ``path.out``. Data written to ``path.in`` will be received by the 3681 guest. Data written by the guest can be read from ``path.out``. QEMU 3682 will not create these fifos, and requires them to be present. 3683 3684 ``path`` forms part of the pipe path as described above. ``path`` is 3685 required. 3686 3687``-chardev console,id=id`` 3688 Send traffic from the guest to QEMU's standard output. ``console`` 3689 does not take any options. 3690 3691 ``console`` is only available on Windows hosts. 3692 3693``-chardev serial,id=id,path=path`` 3694 Send traffic from the guest to a serial device on the host. 3695 3696 On Unix hosts serial will actually accept any tty device, not only 3697 serial lines. 3698 3699 ``path`` specifies the name of the serial device to open. 3700 3701``-chardev pty,id=id`` 3702 Create a new pseudo-terminal on the host and connect to it. ``pty`` 3703 does not take any options. 3704 3705 ``pty`` is not available on Windows hosts. 3706 3707``-chardev stdio,id=id[,signal=on|off]`` 3708 Connect to standard input and standard output of the QEMU process. 3709 3710 ``signal`` controls if signals are enabled on the terminal, that 3711 includes exiting QEMU with the key sequence Control-c. This option 3712 is enabled by default, use ``signal=off`` to disable it. 3713 3714``-chardev braille,id=id`` 3715 Connect to a local BrlAPI server. ``braille`` does not take any 3716 options. 3717 3718``-chardev parallel,id=id,path=path`` 3719 \ 3720 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD 3721 hosts. 3722 3723 Connect to a local parallel port. 3724 3725 ``path`` specifies the path to the parallel port device. ``path`` is 3726 required. 3727 3728``-chardev spicevmc,id=id,debug=debug,name=name`` 3729 ``spicevmc`` is only available when spice support is built in. 3730 3731 ``debug`` debug level for spicevmc 3732 3733 ``name`` name of spice channel to connect to 3734 3735 Connect to a spice virtual machine channel, such as vdiport. 3736 3737``-chardev spiceport,id=id,debug=debug,name=name`` 3738 ``spiceport`` is only available when spice support is built in. 3739 3740 ``debug`` debug level for spicevmc 3741 3742 ``name`` name of spice port to connect to 3743 3744 Connect to a spice port, allowing a Spice client to handle the 3745 traffic identified by a name (preferably a fqdn). 3746ERST 3747 3748DEFHEADING() 3749 3750#ifdef CONFIG_TPM 3751DEFHEADING(TPM device options:) 3752 3753DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3754 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3755 " use path to provide path to a character device; default is /dev/tpm0\n" 3756 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3757 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3758 "-tpmdev emulator,id=id,chardev=dev\n" 3759 " configure the TPM device using chardev backend\n", 3760 QEMU_ARCH_ALL) 3761SRST 3762The general form of a TPM device option is: 3763 3764``-tpmdev backend,id=id[,options]`` 3765 The specific backend type will determine the applicable options. The 3766 ``-tpmdev`` option creates the TPM backend and requires a 3767 ``-device`` option that specifies the TPM frontend interface model. 3768 3769 Use ``-tpmdev help`` to print all available TPM backend types. 3770 3771The available backends are: 3772 3773``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path`` 3774 (Linux-host only) Enable access to the host's TPM using the 3775 passthrough driver. 3776 3777 ``path`` specifies the path to the host's TPM device, i.e., on a 3778 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by 3779 default ``/dev/tpm0`` is used. 3780 3781 ``cancel-path`` specifies the path to the host TPM device's sysfs 3782 entry allowing for cancellation of an ongoing TPM command. 3783 ``cancel-path`` is optional and by default QEMU will search for the 3784 sysfs entry to use. 3785 3786 Some notes about using the host's TPM with the passthrough driver: 3787 3788 The TPM device accessed by the passthrough driver must not be used 3789 by any other application on the host. 3790 3791 Since the host's firmware (BIOS/UEFI) has already initialized the 3792 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize 3793 the TPM again and may therefore not show a TPM-specific menu that 3794 would otherwise allow the user to configure the TPM, e.g., allow the 3795 user to enable/disable or activate/deactivate the TPM. Further, if 3796 TPM ownership is released from within a VM then the host's TPM will 3797 get disabled and deactivated. To enable and activate the TPM again 3798 afterwards, the host has to be rebooted and the user is required to 3799 enter the firmware's menu to enable and activate the TPM. If the TPM 3800 is left disabled and/or deactivated most TPM commands will fail. 3801 3802 To create a passthrough TPM use the following two options: 3803 3804 :: 3805 3806 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3807 3808 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by 3809 ``tpmdev=tpm0`` in the device option. 3810 3811``-tpmdev emulator,id=id,chardev=dev`` 3812 (Linux-host only) Enable access to a TPM emulator using Unix domain 3813 socket based chardev backend. 3814 3815 ``chardev`` specifies the unique ID of a character device backend 3816 that provides connection to the software TPM server. 3817 3818 To create a TPM emulator backend device with chardev socket backend: 3819 3820 :: 3821 3822 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3823ERST 3824 3825DEFHEADING() 3826 3827#endif 3828 3829DEFHEADING(Boot Image or Kernel specific:) 3830SRST 3831There are broadly 4 ways you can boot a system with QEMU. 3832 3833 - specify a firmware and let it control finding a kernel 3834 - specify a firmware and pass a hint to the kernel to boot 3835 - direct kernel image boot 3836 - manually load files into the guest's address space 3837 3838The third method is useful for quickly testing kernels but as there is 3839no firmware to pass configuration information to the kernel the 3840hardware must either be probeable, the kernel built for the exact 3841configuration or passed some configuration data (e.g. a DTB blob) 3842which tells the kernel what drivers it needs. This exact details are 3843often hardware specific. 3844 3845The final method is the most generic way of loading images into the 3846guest address space and used mostly for ``bare metal`` type 3847development where the reset vectors of the processor are taken into 3848account. 3849 3850ERST 3851 3852SRST 3853 3854For x86 machines and some other architectures ``-bios`` will generally 3855do the right thing with whatever it is given. For other machines the 3856more strict ``-pflash`` option needs an image that is sized for the 3857flash device for the given machine type. 3858 3859Please see the :ref:`system-targets-ref` section of the manual for 3860more detailed documentation. 3861 3862ERST 3863 3864DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3865 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3866SRST 3867``-bios file`` 3868 Set the filename for the BIOS. 3869ERST 3870 3871DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 3872 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 3873SRST 3874``-pflash file`` 3875 Use file as a parallel flash image. 3876ERST 3877 3878SRST 3879 3880The kernel options were designed to work with Linux kernels although 3881other things (like hypervisors) can be packaged up as a kernel 3882executable image. The exact format of a executable image is usually 3883architecture specific. 3884 3885The way in which the kernel is started (what address it is loaded at, 3886what if any information is passed to it via CPU registers, the state 3887of the hardware when it is started, and so on) is also architecture 3888specific. Typically it follows the specification laid down by the 3889Linux kernel for how kernels for that architecture must be started. 3890 3891ERST 3892 3893DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3894 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3895SRST 3896``-kernel bzImage`` 3897 Use bzImage as kernel image. The kernel can be either a Linux kernel 3898 or in multiboot format. 3899ERST 3900 3901DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3902 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3903SRST 3904``-append cmdline`` 3905 Use cmdline as kernel command line 3906ERST 3907 3908DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3909 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3910SRST 3911``-initrd file`` 3912 Use file as initial ram disk. 3913 3914``-initrd "file1 arg=foo,file2"`` 3915 This syntax is only available with multiboot. 3916 3917 Use file1 and file2 as modules and pass arg=foo as parameter to the 3918 first module. 3919ERST 3920 3921DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3922 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3923SRST 3924``-dtb file`` 3925 Use file as a device tree binary (dtb) image and pass it to the 3926 kernel on boot. 3927ERST 3928 3929SRST 3930 3931Finally you can also manually load images directly into the address 3932space of the guest. This is most useful for developers who already 3933know the layout of their guest and take care to ensure something sane 3934will happen when the reset vector executes. 3935 3936The generic loader can be invoked by using the loader device: 3937 3938``-device loader,addr=<addr>,data=<data>,data-len=<data-len>[,data-be=<data-be>][,cpu-num=<cpu-num>]`` 3939 3940there is also the guest loader which operates in a similar way but 3941tweaks the DTB so a hypervisor loaded via ``-kernel`` can find where 3942the guest image is: 3943 3944``-device guest-loader,addr=<addr>[,kernel=<path>,[bootargs=<arguments>]][,initrd=<path>]`` 3945 3946ERST 3947 3948DEFHEADING() 3949 3950DEFHEADING(Debug/Expert options:) 3951 3952DEF("compat", HAS_ARG, QEMU_OPTION_compat, 3953 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n" 3954 " Policy for handling deprecated management interfaces\n" 3955 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n" 3956 " Policy for handling unstable management interfaces\n", 3957 QEMU_ARCH_ALL) 3958SRST 3959``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]`` 3960 Set policy for handling deprecated management interfaces (experimental): 3961 3962 ``deprecated-input=accept`` (default) 3963 Accept deprecated commands and arguments 3964 ``deprecated-input=reject`` 3965 Reject deprecated commands and arguments 3966 ``deprecated-input=crash`` 3967 Crash on deprecated commands and arguments 3968 ``deprecated-output=accept`` (default) 3969 Emit deprecated command results and events 3970 ``deprecated-output=hide`` 3971 Suppress deprecated command results and events 3972 3973 Limitation: covers only syntactic aspects of QMP. 3974 3975``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]`` 3976 Set policy for handling unstable management interfaces (experimental): 3977 3978 ``unstable-input=accept`` (default) 3979 Accept unstable commands and arguments 3980 ``unstable-input=reject`` 3981 Reject unstable commands and arguments 3982 ``unstable-input=crash`` 3983 Crash on unstable commands and arguments 3984 ``unstable-output=accept`` (default) 3985 Emit unstable command results and events 3986 ``unstable-output=hide`` 3987 Suppress unstable command results and events 3988 3989 Limitation: covers only syntactic aspects of QMP. 3990ERST 3991 3992DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3993 "-fw_cfg [name=]<name>,file=<file>\n" 3994 " add named fw_cfg entry with contents from file\n" 3995 "-fw_cfg [name=]<name>,string=<str>\n" 3996 " add named fw_cfg entry with contents from string\n", 3997 QEMU_ARCH_ALL) 3998SRST 3999``-fw_cfg [name=]name,file=file`` 4000 Add named fw\_cfg entry with contents from file file. 4001 4002``-fw_cfg [name=]name,string=str`` 4003 Add named fw\_cfg entry with contents from string str. 4004 4005 The terminating NUL character of the contents of str will not be 4006 included as part of the fw\_cfg item data. To insert contents with 4007 embedded NUL characters, you have to use the file parameter. 4008 4009 The fw\_cfg entries are passed by QEMU through to the guest. 4010 4011 Example: 4012 4013 :: 4014 4015 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 4016 4017 creates an fw\_cfg entry named opt/com.mycompany/blob with contents 4018 from ./my\_blob.bin. 4019ERST 4020 4021DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 4022 "-serial dev redirect the serial port to char device 'dev'\n", 4023 QEMU_ARCH_ALL) 4024SRST 4025``-serial dev`` 4026 Redirect the virtual serial port to host character device dev. The 4027 default device is ``vc`` in graphical mode and ``stdio`` in non 4028 graphical mode. 4029 4030 This option can be used several times to simulate up to 4 serial 4031 ports. 4032 4033 Use ``-serial none`` to disable all serial ports. 4034 4035 Available character devices are: 4036 4037 ``vc[:WxH]`` 4038 Virtual console. Optionally, a width and height can be given in 4039 pixel with 4040 4041 :: 4042 4043 vc:800x600 4044 4045 It is also possible to specify width or height in characters: 4046 4047 :: 4048 4049 vc:80Cx24C 4050 4051 ``pty`` 4052 [Linux only] Pseudo TTY (a new PTY is automatically allocated) 4053 4054 ``none`` 4055 No device is allocated. 4056 4057 ``null`` 4058 void device 4059 4060 ``chardev:id`` 4061 Use a named character device defined with the ``-chardev`` 4062 option. 4063 4064 ``/dev/XXX`` 4065 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial 4066 port parameters are set according to the emulated ones. 4067 4068 ``/dev/parportN`` 4069 [Linux only, parallel port only] Use host parallel port N. 4070 Currently SPP and EPP parallel port features can be used. 4071 4072 ``file:filename`` 4073 Write output to filename. No character can be read. 4074 4075 ``stdio`` 4076 [Unix only] standard input/output 4077 4078 ``pipe:filename`` 4079 name pipe filename 4080 4081 ``COMn`` 4082 [Windows only] Use host serial port n 4083 4084 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]`` 4085 This implements UDP Net Console. When remote\_host or src\_ip 4086 are not specified they default to ``0.0.0.0``. When not using a 4087 specified src\_port a random port is automatically chosen. 4088 4089 If you just want a simple readonly console you can use 4090 ``netcat`` or ``nc``, by starting QEMU with: 4091 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time 4092 QEMU writes something to that port it will appear in the 4093 netconsole session. 4094 4095 If you plan to send characters back via netconsole or you want 4096 to stop and start QEMU a lot of times, you should have QEMU use 4097 the same source port each time by using something like ``-serial 4098 udp::4555@:4556`` to QEMU. Another approach is to use a patched 4099 version of netcat which can listen to a TCP port and send and 4100 receive characters via udp. If you have a patched version of 4101 netcat which activates telnet remote echo and single char 4102 transfer, then you can use the following options to set up a 4103 netcat redirector to allow telnet on port 5555 to access the 4104 QEMU port. 4105 4106 ``QEMU Options:`` 4107 -serial udp::4555@:4556 4108 4109 ``netcat options:`` 4110 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 4111 4112 ``telnet options:`` 4113 localhost 5555 4114 4115 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]`` 4116 The TCP Net Console has two modes of operation. It can send the 4117 serial I/O to a location or wait for a connection from a 4118 location. By default the TCP Net Console is sent to host at the 4119 port. If you use the ``server=on`` option QEMU will wait for a client 4120 socket application to connect to the port before continuing, 4121 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off`` 4122 option disables the Nagle buffering algorithm. The ``reconnect=on`` 4123 option only applies if ``server=no`` is set, if the connection goes 4124 down it will attempt to reconnect at the given interval. If host 4125 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a 4126 time is accepted. You can use ``telnet=on`` to connect to the 4127 corresponding character device. 4128 4129 ``Example to send tcp console to 192.168.0.2 port 4444`` 4130 -serial tcp:192.168.0.2:4444 4131 4132 ``Example to listen and wait on port 4444 for connection`` 4133 -serial tcp::4444,server=on 4134 4135 ``Example to not wait and listen on ip 192.168.0.100 port 4444`` 4136 -serial tcp:192.168.0.100:4444,server=on,wait=off 4137 4138 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]`` 4139 The telnet protocol is used instead of raw tcp sockets. The 4140 options work the same as if you had specified ``-serial tcp``. 4141 The difference is that the port acts like a telnet server or 4142 client using telnet option negotiation. This will also allow you 4143 to send the MAGIC\_SYSRQ sequence if you use a telnet that 4144 supports sending the break sequence. Typically in unix telnet 4145 you do it with Control-] and then type "send break" followed by 4146 pressing the enter key. 4147 4148 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]`` 4149 The WebSocket protocol is used instead of raw tcp socket. The 4150 port acts as a WebSocket server. Client mode is not supported. 4151 4152 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]`` 4153 A unix domain socket is used instead of a tcp socket. The option 4154 works the same as if you had specified ``-serial tcp`` except 4155 the unix domain socket path is used for connections. 4156 4157 ``mon:dev_string`` 4158 This is a special option to allow the monitor to be multiplexed 4159 onto another serial port. The monitor is accessed with key 4160 sequence of Control-a and then pressing c. dev\_string should be 4161 any one of the serial devices specified above. An example to 4162 multiplex the monitor onto a telnet server listening on port 4163 4444 would be: 4164 4165 ``-serial mon:telnet::4444,server=on,wait=off`` 4166 4167 When the monitor is multiplexed to stdio in this way, Ctrl+C 4168 will not terminate QEMU any more but will be passed to the guest 4169 instead. 4170 4171 ``braille`` 4172 Braille device. This will use BrlAPI to display the braille 4173 output on a real or fake device. 4174 4175 ``msmouse`` 4176 Three button serial mouse. Configure the guest to use Microsoft 4177 protocol. 4178ERST 4179 4180DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 4181 "-parallel dev redirect the parallel port to char device 'dev'\n", 4182 QEMU_ARCH_ALL) 4183SRST 4184``-parallel dev`` 4185 Redirect the virtual parallel port to host device dev (same devices 4186 as the serial port). On Linux hosts, ``/dev/parportN`` can be used 4187 to use hardware devices connected on the corresponding host parallel 4188 port. 4189 4190 This option can be used several times to simulate up to 3 parallel 4191 ports. 4192 4193 Use ``-parallel none`` to disable all parallel ports. 4194ERST 4195 4196DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 4197 "-monitor dev redirect the monitor to char device 'dev'\n", 4198 QEMU_ARCH_ALL) 4199SRST 4200``-monitor dev`` 4201 Redirect the monitor to host device dev (same devices as the serial 4202 port). The default device is ``vc`` in graphical mode and ``stdio`` 4203 in non graphical mode. Use ``-monitor none`` to disable the default 4204 monitor. 4205ERST 4206DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 4207 "-qmp dev like -monitor but opens in 'control' mode\n", 4208 QEMU_ARCH_ALL) 4209SRST 4210``-qmp dev`` 4211 Like ``-monitor`` but opens in 'control' mode. For example, to make 4212 QMP available on localhost port 4444:: 4213 4214 -qmp tcp:localhost:4444,server=on,wait=off 4215 4216 Not all options are configurable via this syntax; for maximum 4217 flexibility use the ``-mon`` option and an accompanying ``-chardev``. 4218 4219ERST 4220DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 4221 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 4222 QEMU_ARCH_ALL) 4223SRST 4224``-qmp-pretty dev`` 4225 Like ``-qmp`` but uses pretty JSON formatting. 4226ERST 4227 4228DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 4229 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 4230SRST 4231``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]`` 4232 Set up a monitor connected to the chardev ``name``. 4233 QEMU supports two monitors: the Human Monitor Protocol 4234 (HMP; for human interaction), and the QEMU Monitor Protocol 4235 (QMP; a JSON RPC-style protocol). 4236 The default is HMP; ``mode=control`` selects QMP instead. 4237 ``pretty`` is only valid when ``mode=control``, 4238 turning on JSON pretty printing to ease 4239 human reading and debugging. 4240 4241 For example:: 4242 4243 -chardev socket,id=mon1,host=localhost,port=4444,server=on,wait=off \ 4244 -mon chardev=mon1,mode=control,pretty=on 4245 4246 enables the QMP monitor on localhost port 4444 with pretty-printing. 4247ERST 4248 4249DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 4250 "-debugcon dev redirect the debug console to char device 'dev'\n", 4251 QEMU_ARCH_ALL) 4252SRST 4253``-debugcon dev`` 4254 Redirect the debug console to host device dev (same devices as the 4255 serial port). The debug console is an I/O port which is typically 4256 port 0xe9; writing to that I/O port sends output to this device. The 4257 default device is ``vc`` in graphical mode and ``stdio`` in non 4258 graphical mode. 4259ERST 4260 4261DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 4262 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 4263SRST 4264``-pidfile file`` 4265 Store the QEMU process PID in file. It is useful if you launch QEMU 4266 from a script. 4267ERST 4268 4269DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 4270 "-singlestep deprecated synonym for -accel tcg,one-insn-per-tb=on\n", QEMU_ARCH_ALL) 4271SRST 4272``-singlestep`` 4273 This is a deprecated synonym for the TCG accelerator property 4274 ``one-insn-per-tb``. 4275ERST 4276 4277DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 4278 "--preconfig pause QEMU before machine is initialized (experimental)\n", 4279 QEMU_ARCH_ALL) 4280SRST 4281``--preconfig`` 4282 Pause QEMU for interactive configuration before the machine is 4283 created, which allows querying and configuring properties that will 4284 affect machine initialization. Use QMP command 'x-exit-preconfig' to 4285 exit the preconfig state and move to the next state (i.e. run guest 4286 if -S isn't used or pause the second time if -S is used). This 4287 option is experimental. 4288ERST 4289 4290DEF("S", 0, QEMU_OPTION_S, \ 4291 "-S freeze CPU at startup (use 'c' to start execution)\n", 4292 QEMU_ARCH_ALL) 4293SRST 4294``-S`` 4295 Do not start CPU at startup (you must type 'c' in the monitor). 4296ERST 4297 4298DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 4299 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 4300 " run qemu with overcommit hints\n" 4301 " mem-lock=on|off controls memory lock support (default: off)\n" 4302 " cpu-pm=on|off controls cpu power management (default: off)\n", 4303 QEMU_ARCH_ALL) 4304SRST 4305``-overcommit mem-lock=on|off`` 4306 \ 4307``-overcommit cpu-pm=on|off`` 4308 Run qemu with hints about host resource overcommit. The default is 4309 to assume that host overcommits all resources. 4310 4311 Locking qemu and guest memory can be enabled via ``mem-lock=on`` 4312 (disabled by default). This works when host memory is not 4313 overcommitted and reduces the worst-case latency for guest. 4314 4315 Guest ability to manage power state of host cpus (increasing latency 4316 for other processes on the same host cpu, but decreasing latency for 4317 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This 4318 works best when host CPU is not overcommitted. When used, host 4319 estimates of CPU cycle and power utilization will be incorrect, not 4320 taking into account guest idle time. 4321ERST 4322 4323DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 4324 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n" 4325 " the guest without waiting for gdb to connect; use -S too\n" 4326 " if you want it to not start execution.)\n", 4327 QEMU_ARCH_ALL) 4328SRST 4329``-gdb dev`` 4330 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter 4331 in the System Emulation Users Guide). Note that this option does not pause QEMU 4332 execution -- if you want QEMU to not start the guest until you 4333 connect with gdb and issue a ``continue`` command, you will need to 4334 also pass the ``-S`` option to QEMU. 4335 4336 The most usual configuration is to listen on a local TCP socket:: 4337 4338 -gdb tcp::3117 4339 4340 but you can specify other backends; UDP, pseudo TTY, or even stdio 4341 are all reasonable use cases. For example, a stdio connection 4342 allows you to start QEMU from within gdb and establish the 4343 connection via a pipe: 4344 4345 .. parsed-literal:: 4346 4347 (gdb) target remote | exec |qemu_system| -gdb stdio ... 4348ERST 4349 4350DEF("s", 0, QEMU_OPTION_s, \ 4351 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 4352 QEMU_ARCH_ALL) 4353SRST 4354``-s`` 4355 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 4356 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide). 4357ERST 4358 4359DEF("d", HAS_ARG, QEMU_OPTION_d, \ 4360 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 4361 QEMU_ARCH_ALL) 4362SRST 4363``-d item1[,...]`` 4364 Enable logging of specified items. Use '-d help' for a list of log 4365 items. 4366ERST 4367 4368DEF("D", HAS_ARG, QEMU_OPTION_D, \ 4369 "-D logfile output log to logfile (default stderr)\n", 4370 QEMU_ARCH_ALL) 4371SRST 4372``-D logfile`` 4373 Output log in logfile instead of to stderr 4374ERST 4375 4376DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 4377 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 4378 QEMU_ARCH_ALL) 4379SRST 4380``-dfilter range1[,...]`` 4381 Filter debug output to that relevant to a range of target addresses. 4382 The filter spec can be either start+size, start-size or start..end 4383 where start end and size are the addresses and sizes required. For 4384 example: 4385 4386 :: 4387 4388 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 4389 4390 Will dump output for any code in the 0x1000 sized block starting at 4391 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and 4392 another 0x1000 sized block starting at 0xffffffc00005f000. 4393ERST 4394 4395DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 4396 "-seed number seed the pseudo-random number generator\n", 4397 QEMU_ARCH_ALL) 4398SRST 4399``-seed number`` 4400 Force the guest to use a deterministic pseudo-random number 4401 generator, seeded with number. This does not affect crypto routines 4402 within the host. 4403ERST 4404 4405DEF("L", HAS_ARG, QEMU_OPTION_L, \ 4406 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 4407 QEMU_ARCH_ALL) 4408SRST 4409``-L path`` 4410 Set the directory for the BIOS, VGA BIOS and keymaps. 4411 4412 To list all the data directories, use ``-L help``. 4413ERST 4414 4415DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 4416 "-enable-kvm enable KVM full virtualization support\n", 4417 QEMU_ARCH_ARM | QEMU_ARCH_I386 | QEMU_ARCH_MIPS | QEMU_ARCH_PPC | 4418 QEMU_ARCH_RISCV | QEMU_ARCH_S390X) 4419SRST 4420``-enable-kvm`` 4421 Enable KVM full virtualization support. This option is only 4422 available if KVM support is enabled when compiling. 4423ERST 4424 4425DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 4426 "-xen-domid id specify xen guest domain id\n", 4427 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4428DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 4429 "-xen-attach attach to existing xen domain\n" 4430 " libxl will use this when starting QEMU\n", 4431 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4432DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 4433 "-xen-domid-restrict restrict set of available xen operations\n" 4434 " to specified domain id. (Does not affect\n" 4435 " xenpv machine type).\n", 4436 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4437SRST 4438``-xen-domid id`` 4439 Specify xen guest domain id (XEN only). 4440 4441``-xen-attach`` 4442 Attach to existing xen domain. libxl will use this when starting 4443 QEMU (XEN only). Restrict set of available xen operations to 4444 specified domain id (XEN only). 4445ERST 4446 4447DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 4448 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 4449SRST 4450``-no-reboot`` 4451 Exit instead of rebooting. 4452ERST 4453 4454DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 4455 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 4456SRST 4457``-no-shutdown`` 4458 Don't exit QEMU on guest shutdown, but instead only stop the 4459 emulation. This allows for instance switching to monitor to commit 4460 changes to the disk image. 4461ERST 4462 4463DEF("action", HAS_ARG, QEMU_OPTION_action, 4464 "-action reboot=reset|shutdown\n" 4465 " action when guest reboots [default=reset]\n" 4466 "-action shutdown=poweroff|pause\n" 4467 " action when guest shuts down [default=poweroff]\n" 4468 "-action panic=pause|shutdown|exit-failure|none\n" 4469 " action when guest panics [default=shutdown]\n" 4470 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" 4471 " action when watchdog fires [default=reset]\n", 4472 QEMU_ARCH_ALL) 4473SRST 4474``-action event=action`` 4475 The action parameter serves to modify QEMU's default behavior when 4476 certain guest events occur. It provides a generic method for specifying the 4477 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown`` 4478 parameters. 4479 4480 Examples: 4481 4482 ``-action panic=none`` 4483 ``-action reboot=shutdown,shutdown=pause`` 4484 ``-device i6300esb -action watchdog=pause`` 4485 4486ERST 4487 4488DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 4489 "-loadvm [tag|id]\n" \ 4490 " start right away with a saved state (loadvm in monitor)\n", 4491 QEMU_ARCH_ALL) 4492SRST 4493``-loadvm file`` 4494 Start right away with a saved state (``loadvm`` in monitor) 4495ERST 4496 4497#ifndef _WIN32 4498DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 4499 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 4500#endif 4501SRST 4502``-daemonize`` 4503 Daemonize the QEMU process after initialization. QEMU will not 4504 detach from standard IO until it is ready to receive connections on 4505 any of its devices. This option is a useful way for external 4506 programs to launch QEMU without having to cope with initialization 4507 race conditions. 4508ERST 4509 4510DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 4511 "-option-rom rom load a file, rom, into the option ROM space\n", 4512 QEMU_ARCH_ALL) 4513SRST 4514``-option-rom file`` 4515 Load the contents of file as an option ROM. This option is useful to 4516 load things like EtherBoot. 4517ERST 4518 4519DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 4520 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 4521 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 4522 QEMU_ARCH_ALL) 4523 4524SRST 4525``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]`` 4526 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at 4527 the current UTC or local time, respectively. ``localtime`` is 4528 required for correct date in MS-DOS or Windows. To start at a 4529 specific point in time, provide datetime in the format 4530 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC. 4531 4532 By default the RTC is driven by the host system time. This allows 4533 using of the RTC as accurate reference clock inside the guest, 4534 specifically if the host time is smoothly following an accurate 4535 external reference clock, e.g. via NTP. If you want to isolate the 4536 guest time from the host, you can set ``clock`` to ``rt`` instead, 4537 which provides a host monotonic clock if host support it. To even 4538 prevent the RTC from progressing during suspension, you can set 4539 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is 4540 recommended especially in icount mode in order to preserve 4541 determinism; however, note that in icount mode the speed of the 4542 virtual clock is variable and can in general differ from the host 4543 clock. 4544 4545 Enable ``driftfix`` (i386 targets only) if you experience time drift 4546 problems, specifically with Windows' ACPI HAL. This option will try 4547 to figure out how many timer interrupts were not processed by the 4548 Windows guest and will re-inject them. 4549ERST 4550 4551DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 4552 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \ 4553 " enable virtual instruction counter with 2^N clock ticks per\n" \ 4554 " instruction, enable aligning the host and virtual clocks\n" \ 4555 " or disable real time cpu sleeping, and optionally enable\n" \ 4556 " record-and-replay mode\n", QEMU_ARCH_ALL) 4557SRST 4558``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]`` 4559 Enable virtual instruction counter. The virtual cpu will execute one 4560 instruction every 2^N ns of virtual time. If ``auto`` is specified 4561 then the virtual cpu speed will be automatically adjusted to keep 4562 virtual time within a few seconds of real time. 4563 4564 Note that while this option can give deterministic behavior, it does 4565 not provide cycle accurate emulation. Modern CPUs contain 4566 superscalar out of order cores with complex cache hierarchies. The 4567 number of instructions executed often has little or no correlation 4568 with actual performance. 4569 4570 When the virtual cpu is sleeping, the virtual time will advance at 4571 default speed unless ``sleep=on`` is specified. With 4572 ``sleep=on``, the virtual time will jump to the next timer 4573 deadline instantly whenever the virtual cpu goes to sleep mode and 4574 will not advance if no timer is enabled. This behavior gives 4575 deterministic execution times from the guest point of view. 4576 The default if icount is enabled is ``sleep=off``. 4577 ``sleep=on`` cannot be used together with either ``shift=auto`` 4578 or ``align=on``. 4579 4580 ``align=on`` will activate the delay algorithm which will try to 4581 synchronise the host clock and the virtual clock. The goal is to 4582 have a guest running at the real frequency imposed by the shift 4583 option. Whenever the guest clock is behind the host clock and if 4584 ``align=on`` is specified then we print a message to the user to 4585 inform about the delay. Currently this option does not work when 4586 ``shift`` is ``auto``. Note: The sync algorithm will work for those 4587 shift values for which the guest clock runs ahead of the host clock. 4588 Typically this happens when the shift value is high (how high 4589 depends on the host machine). The default if icount is enabled 4590 is ``align=off``. 4591 4592 When the ``rr`` option is specified deterministic record/replay is 4593 enabled. The ``rrfile=`` option must also be provided to 4594 specify the path to the replay log. In record mode data is written 4595 to this file, and in replay mode it is read back. 4596 If the ``rrsnapshot`` option is given then it specifies a VM snapshot 4597 name. In record mode, a new VM snapshot with the given name is created 4598 at the start of execution recording. In replay mode this option 4599 specifies the snapshot name used to load the initial VM state. 4600ERST 4601 4602DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 4603 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 4604 " action when watchdog fires [default=reset]\n", 4605 QEMU_ARCH_ALL) 4606SRST 4607``-watchdog-action action`` 4608 The action controls what QEMU will do when the watchdog timer 4609 expires. The default is ``reset`` (forcefully reset the guest). 4610 Other possible actions are: ``shutdown`` (attempt to gracefully 4611 shutdown the guest), ``poweroff`` (forcefully poweroff the guest), 4612 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the 4613 guest), ``debug`` (print a debug message and continue), or ``none`` 4614 (do nothing). 4615 4616 Note that the ``shutdown`` action requires that the guest responds 4617 to ACPI signals, which it may not be able to do in the sort of 4618 situations where the watchdog would have expired, and thus 4619 ``-watchdog-action shutdown`` is not recommended for production use. 4620 4621 Examples: 4622 4623 ``-device i6300esb -watchdog-action pause`` 4624 4625ERST 4626 4627DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 4628 "-echr chr set terminal escape character instead of ctrl-a\n", 4629 QEMU_ARCH_ALL) 4630SRST 4631``-echr numeric_ascii_value`` 4632 Change the escape character used for switching to the monitor when 4633 using monitor and serial sharing. The default is ``0x01`` when using 4634 the ``-nographic`` option. ``0x01`` is equal to pressing 4635 ``Control-a``. You can select a different character from the ascii 4636 control keys where 1 through 26 map to Control-a through Control-z. 4637 For instance you could use the either of the following to change the 4638 escape character to Control-t. 4639 4640 ``-echr 0x14``; \ ``-echr 20`` 4641 4642ERST 4643 4644DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4645 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \ 4646 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \ 4647 "-incoming unix:socketpath\n" \ 4648 " prepare for incoming migration, listen on\n" \ 4649 " specified protocol and socket address\n" \ 4650 "-incoming fd:fd\n" \ 4651 "-incoming exec:cmdline\n" \ 4652 " accept incoming migration on given file descriptor\n" \ 4653 " or from given external command\n" \ 4654 "-incoming defer\n" \ 4655 " wait for the URI to be specified via migrate_incoming\n", 4656 QEMU_ARCH_ALL) 4657SRST 4658``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]`` 4659 \ 4660``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]`` 4661 Prepare for incoming migration, listen on a given tcp port. 4662 4663``-incoming unix:socketpath`` 4664 Prepare for incoming migration, listen on a given unix socket. 4665 4666``-incoming fd:fd`` 4667 Accept incoming migration from a given filedescriptor. 4668 4669``-incoming exec:cmdline`` 4670 Accept incoming migration as an output from specified external 4671 command. 4672 4673``-incoming defer`` 4674 Wait for the URI to be specified via migrate\_incoming. The monitor 4675 can be used to change settings (such as migration parameters) prior 4676 to issuing the migrate\_incoming to allow the migration to begin. 4677ERST 4678 4679DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4680 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4681SRST 4682``-only-migratable`` 4683 Only allow migratable devices. Devices will not be allowed to enter 4684 an unmigratable state. 4685ERST 4686 4687DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4688 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4689SRST 4690``-nodefaults`` 4691 Don't create default devices. Normally, QEMU sets the default 4692 devices like serial port, parallel port, virtual console, monitor 4693 device, VGA adapter, floppy and CD-ROM drive and others. The 4694 ``-nodefaults`` option will disable all those default devices. 4695ERST 4696 4697#ifndef _WIN32 4698DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4699 "-chroot dir chroot to dir just before starting the VM (deprecated)\n", 4700 QEMU_ARCH_ALL) 4701#endif 4702SRST 4703``-chroot dir`` 4704 Deprecated, use '-run-with chroot=...' instead. 4705 Immediately before starting guest execution, chroot to the specified 4706 directory. Especially useful in combination with -runas. 4707ERST 4708 4709#ifndef _WIN32 4710DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4711 "-runas user change to user id user just before starting the VM\n" \ 4712 " user can be numeric uid:gid instead\n", 4713 QEMU_ARCH_ALL) 4714#endif 4715SRST 4716``-runas user`` 4717 Immediately before starting guest execution, drop root privileges, 4718 switching to the specified user. 4719ERST 4720 4721DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4722 "-prom-env variable=value\n" 4723 " set OpenBIOS nvram variables\n", 4724 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4725SRST 4726``-prom-env variable=value`` 4727 Set OpenBIOS nvram variable to given value (PPC, SPARC only). 4728 4729 :: 4730 4731 qemu-system-sparc -prom-env 'auto-boot?=false' \ 4732 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' 4733 4734 :: 4735 4736 qemu-system-ppc -prom-env 'auto-boot?=false' \ 4737 -prom-env 'boot-device=hd:2,\yaboot' \ 4738 -prom-env 'boot-args=conf=hd:2,\yaboot.conf' 4739ERST 4740DEF("semihosting", 0, QEMU_OPTION_semihosting, 4741 "-semihosting semihosting mode\n", 4742 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4743 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4744SRST 4745``-semihosting`` 4746 Enable :ref:`Semihosting` mode (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V only). 4747 4748 .. warning:: 4749 Note that this allows guest direct access to the host filesystem, so 4750 should only be used with a trusted guest OS. 4751 4752 See the -semihosting-config option documentation for further 4753 information about the facilities this enables. 4754ERST 4755DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4756 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]\n" \ 4757 " semihosting configuration\n", 4758QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4759QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4760SRST 4761``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]`` 4762 Enable and configure :ref:`Semihosting` (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V 4763 only). 4764 4765 .. warning:: 4766 Note that this allows guest direct access to the host filesystem, so 4767 should only be used with a trusted guest OS. 4768 4769 ``target=native|gdb|auto`` 4770 Defines where the semihosting calls will be addressed, to QEMU 4771 (``native``) or to GDB (``gdb``). The default is ``auto``, which 4772 means ``gdb`` during debug sessions and ``native`` otherwise. 4773 4774 ``chardev=str1`` 4775 Send the output to a chardev backend output for native or auto 4776 output when not in gdb 4777 4778 ``userspace=on|off`` 4779 Allows code running in guest userspace to access the semihosting 4780 interface. The default is that only privileged guest code can 4781 make semihosting calls. Note that setting ``userspace=on`` should 4782 only be used if all guest code is trusted (for example, in 4783 bare-metal test case code). 4784 4785 ``arg=str1,arg=str2,...`` 4786 Allows the user to pass input arguments, and can be used 4787 multiple times to build up a list. The old-style 4788 ``-kernel``/``-append`` method of passing a command line is 4789 still supported for backward compatibility. If both the 4790 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are 4791 specified, the former is passed to semihosting as it always 4792 takes precedence. 4793ERST 4794DEF("old-param", 0, QEMU_OPTION_old_param, 4795 "-old-param old param mode\n", QEMU_ARCH_ARM) 4796SRST 4797``-old-param`` 4798 Old param mode (ARM only). 4799ERST 4800 4801DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4802 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4803 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4804 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4805 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4806 " by the kernel, but typically no longer used by modern\n" \ 4807 " C library implementations.\n" \ 4808 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \ 4809 " to elevate privileges using set*uid|gid system calls.\n" \ 4810 " The value 'children' will deny set*uid|gid system calls for\n" \ 4811 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4812 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4813 " blocking *fork and execve\n" \ 4814 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4815 QEMU_ARCH_ALL) 4816SRST 4817``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]`` 4818 Enable Seccomp mode 2 system call filter. 'on' will enable syscall 4819 filtering and 'off' will disable it. The default is 'off'. 4820 4821 ``obsolete=string`` 4822 Enable Obsolete system calls 4823 4824 ``elevateprivileges=string`` 4825 Disable set\*uid\|gid system calls 4826 4827 ``spawn=string`` 4828 Disable \*fork and execve 4829 4830 ``resourcecontrol=string`` 4831 Disable process affinity and schedular priority 4832ERST 4833 4834DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4835 "-readconfig <file>\n" 4836 " read config file\n", QEMU_ARCH_ALL) 4837SRST 4838``-readconfig file`` 4839 Read device configuration from file. This approach is useful when 4840 you want to spawn QEMU process with many command line options but 4841 you don't want to exceed the command line character limit. 4842ERST 4843 4844DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4845 "-no-user-config\n" 4846 " do not load default user-provided config files at startup\n", 4847 QEMU_ARCH_ALL) 4848SRST 4849``-no-user-config`` 4850 The ``-no-user-config`` option makes QEMU not load any of the 4851 user-provided config files on sysconfdir. 4852ERST 4853 4854DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4855 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4856 " specify tracing options\n", 4857 QEMU_ARCH_ALL) 4858SRST 4859``-trace [[enable=]pattern][,events=file][,file=file]`` 4860 .. include:: ../qemu-option-trace.rst.inc 4861 4862ERST 4863DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4864 "-plugin [file=]<file>[,<argname>=<argvalue>]\n" 4865 " load a plugin\n", 4866 QEMU_ARCH_ALL) 4867SRST 4868``-plugin file=file[,argname=argvalue]`` 4869 Load a plugin. 4870 4871 ``file=file`` 4872 Load the given plugin from a shared library file. 4873 4874 ``argname=argvalue`` 4875 Argument passed to the plugin. (Can be given multiple times.) 4876ERST 4877 4878HXCOMM Internal use 4879DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4880DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4881 4882#ifdef __linux__ 4883DEF("async-teardown", 0, QEMU_OPTION_asyncteardown, 4884 "-async-teardown enable asynchronous teardown\n", 4885 QEMU_ARCH_ALL) 4886SRST 4887``-async-teardown`` 4888 This option is deprecated and should no longer be used. The new option 4889 ``-run-with async-teardown=on`` is a replacement. 4890ERST 4891#endif 4892#ifdef CONFIG_POSIX 4893DEF("run-with", HAS_ARG, QEMU_OPTION_run_with, 4894 "-run-with [async-teardown=on|off][,chroot=dir]\n" 4895 " Set miscellaneous QEMU process lifecycle options:\n" 4896 " async-teardown=on enables asynchronous teardown (Linux only)\n" 4897 " chroot=dir chroot to dir just before starting the VM\n", 4898 QEMU_ARCH_ALL) 4899SRST 4900``-run-with [async-teardown=on|off][,chroot=dir]`` 4901 Set QEMU process lifecycle options. 4902 4903 ``async-teardown=on`` enables asynchronous teardown. A new process called 4904 "cleanup/<QEMU_PID>" will be created at startup sharing the address 4905 space with the main QEMU process, using clone. It will wait for the 4906 main QEMU process to terminate completely, and then exit. This allows 4907 QEMU to terminate very quickly even if the guest was huge, leaving the 4908 teardown of the address space to the cleanup process. Since the cleanup 4909 process shares the same cgroups as the main QEMU process, accounting is 4910 performed correctly. This only works if the cleanup process is not 4911 forcefully killed with SIGKILL before the main QEMU process has 4912 terminated completely. 4913 4914 ``chroot=dir`` can be used for doing a chroot to the specified directory 4915 immediately before starting the guest execution. This is especially useful 4916 in combination with -runas. 4917ERST 4918#endif 4919 4920DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4921 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n" 4922 " control error message format\n" 4923 " timestamp=on enables timestamps (default: off)\n" 4924 " guest-name=on enables guest name prefix but only if\n" 4925 " -name guest option is set (default: off)\n", 4926 QEMU_ARCH_ALL) 4927SRST 4928``-msg [timestamp[=on|off]][,guest-name[=on|off]]`` 4929 Control error message format. 4930 4931 ``timestamp=on|off`` 4932 Prefix messages with a timestamp. Default is off. 4933 4934 ``guest-name=on|off`` 4935 Prefix messages with guest name but only if -name guest option is set 4936 otherwise the option is ignored. Default is off. 4937ERST 4938 4939DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4940 "-dump-vmstate <file>\n" 4941 " Output vmstate information in JSON format to file.\n" 4942 " Use the scripts/vmstate-static-checker.py file to\n" 4943 " check for possible regressions in migration code\n" 4944 " by comparing two such vmstate dumps.\n", 4945 QEMU_ARCH_ALL) 4946SRST 4947``-dump-vmstate file`` 4948 Dump json-encoded vmstate information for current machine type to 4949 file in file 4950ERST 4951 4952DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4953 "-enable-sync-profile\n" 4954 " enable synchronization profiling\n", 4955 QEMU_ARCH_ALL) 4956SRST 4957``-enable-sync-profile`` 4958 Enable synchronization profiling. 4959ERST 4960 4961#if defined(CONFIG_TCG) && defined(CONFIG_LINUX) 4962DEF("perfmap", 0, QEMU_OPTION_perfmap, 4963 "-perfmap generate a /tmp/perf-${pid}.map file for perf\n", 4964 QEMU_ARCH_ALL) 4965SRST 4966``-perfmap`` 4967 Generate a map file for Linux perf tools that will allow basic profiling 4968 information to be broken down into basic blocks. 4969ERST 4970 4971DEF("jitdump", 0, QEMU_OPTION_jitdump, 4972 "-jitdump generate a jit-${pid}.dump file for perf\n", 4973 QEMU_ARCH_ALL) 4974SRST 4975``-jitdump`` 4976 Generate a dump file for Linux perf tools that maps basic blocks to symbol 4977 names, line numbers and JITted code. 4978ERST 4979#endif 4980 4981DEFHEADING() 4982 4983DEFHEADING(Generic object creation:) 4984 4985DEF("object", HAS_ARG, QEMU_OPTION_object, 4986 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4987 " create a new object of type TYPENAME setting properties\n" 4988 " in the order they are specified. Note that the 'id'\n" 4989 " property must be set. These objects are placed in the\n" 4990 " '/objects' path.\n", 4991 QEMU_ARCH_ALL) 4992SRST 4993``-object typename[,prop1=value1,...]`` 4994 Create a new object of type typename setting properties in the order 4995 they are specified. Note that the 'id' property must be set. These 4996 objects are placed in the '/objects' path. 4997 4998 ``-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`` 4999 Creates a memory file backend object, which can be used to back 5000 the guest RAM with huge pages. 5001 5002 The ``id`` parameter is a unique ID that will be used to 5003 reference this memory region in other parameters, e.g. ``-numa``, 5004 ``-device nvdimm``, etc. 5005 5006 The ``size`` option provides the size of the memory region, and 5007 accepts common suffixes, e.g. ``500M``. 5008 5009 The ``mem-path`` provides the path to either a shared memory or 5010 huge page filesystem mount. 5011 5012 The ``share`` boolean option determines whether the memory 5013 region is marked as private to QEMU, or shared. The latter 5014 allows a co-operating external process to access the QEMU memory 5015 region. 5016 5017 The ``share`` is also required for pvrdma devices due to 5018 limitations in the RDMA API provided by Linux. 5019 5020 Setting share=on might affect the ability to configure NUMA 5021 bindings for the memory backend under some circumstances, see 5022 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel 5023 source tree for additional details. 5024 5025 Setting the ``discard-data`` boolean option to on indicates that 5026 file contents can be destroyed when QEMU exits, to avoid 5027 unnecessarily flushing data to the backing file. Note that 5028 ``discard-data`` is only an optimization, and QEMU might not 5029 discard file contents if it aborts unexpectedly or is terminated 5030 using SIGKILL. 5031 5032 The ``merge`` boolean option enables memory merge, also known as 5033 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider 5034 the pages for memory deduplication. 5035 5036 Setting the ``dump`` boolean option to off excludes the memory 5037 from core dumps. This feature is also known as MADV\_DONTDUMP. 5038 5039 The ``prealloc`` boolean option enables memory preallocation. 5040 5041 The ``host-nodes`` option binds the memory range to a list of 5042 NUMA host nodes. 5043 5044 The ``policy`` option sets the NUMA policy to one of the 5045 following values: 5046 5047 ``default`` 5048 default host policy 5049 5050 ``preferred`` 5051 prefer the given host node list for allocation 5052 5053 ``bind`` 5054 restrict memory allocation to the given host node list 5055 5056 ``interleave`` 5057 interleave memory allocations across the given host node 5058 list 5059 5060 The ``align`` option specifies the base address alignment when 5061 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg 5062 ``2M``. Some backend store specified by ``mem-path`` requires an 5063 alignment different than the default one used by QEMU, eg the 5064 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 5065 such cases, users can specify the required alignment via this 5066 option. 5067 5068 The ``offset`` option specifies the offset into the target file 5069 that the region starts at. You can use this parameter to back 5070 multiple regions with a single file. 5071 5072 The ``pmem`` option specifies whether the backing file specified 5073 by ``mem-path`` is in host persistent memory that can be 5074 accessed using the SNIA NVM programming model (e.g. Intel 5075 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary 5076 operations to guarantee the persistence of its own writes to 5077 ``mem-path`` (e.g. in vNVDIMM label emulation and live 5078 migration). Also, we will map the backend-file with MAP\_SYNC 5079 flag, which ensures the file metadata is in sync for 5080 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC 5081 requires support from both the host kernel (since Linux kernel 5082 4.15) and the filesystem of ``mem-path`` mounted with DAX 5083 option. 5084 5085 The ``readonly`` option specifies whether the backing file is opened 5086 read-only or read-write (default). 5087 5088 ``-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`` 5089 Creates a memory backend object, which can be used to back the 5090 guest RAM. Memory backend objects offer more control than the 5091 ``-m`` option that is traditionally used to define guest RAM. 5092 Please refer to ``memory-backend-file`` for a description of the 5093 options. 5094 5095 ``-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`` 5096 Creates an anonymous memory file backend object, which allows 5097 QEMU to share the memory with an external process (e.g. when 5098 using vhost-user). The memory is allocated with memfd and 5099 optional sealing. (Linux only) 5100 5101 The ``seal`` option creates a sealed-file, that will block 5102 further resizing the memory ('on' by default). 5103 5104 The ``hugetlb`` option specify the file to be created resides in 5105 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction 5106 with the ``hugetlb`` option, the ``hugetlbsize`` option specify 5107 the hugetlb page size on systems that support multiple hugetlb 5108 page sizes (it must be a power of 2 value supported by the 5109 system). 5110 5111 In some versions of Linux, the ``hugetlb`` option is 5112 incompatible with the ``seal`` option (requires at least Linux 5113 4.16). 5114 5115 Please refer to ``memory-backend-file`` for a description of the 5116 other options. 5117 5118 The ``share`` boolean option is on by default with memfd. 5119 5120 ``-object rng-builtin,id=id`` 5121 Creates a random number generator backend which obtains entropy 5122 from QEMU builtin functions. The ``id`` parameter is a unique ID 5123 that will be used to reference this entropy backend from the 5124 ``virtio-rng`` device. By default, the ``virtio-rng`` device 5125 uses this RNG backend. 5126 5127 ``-object rng-random,id=id,filename=/dev/random`` 5128 Creates a random number generator backend which obtains entropy 5129 from a device on the host. The ``id`` parameter is a unique ID 5130 that will be used to reference this entropy backend from the 5131 ``virtio-rng`` device. The ``filename`` parameter specifies 5132 which file to obtain entropy from and if omitted defaults to 5133 ``/dev/urandom``. 5134 5135 ``-object rng-egd,id=id,chardev=chardevid`` 5136 Creates a random number generator backend which obtains entropy 5137 from an external daemon running on the host. The ``id`` 5138 parameter is a unique ID that will be used to reference this 5139 entropy backend from the ``virtio-rng`` device. The ``chardev`` 5140 parameter is the unique ID of a character device backend that 5141 provides the connection to the RNG daemon. 5142 5143 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off`` 5144 Creates a TLS anonymous credentials object, which can be used to 5145 provide TLS support on network backends. The ``id`` parameter is 5146 a unique ID which network backends will use to access the 5147 credentials. The ``endpoint`` is either ``server`` or ``client`` 5148 depending on whether the QEMU network backend that uses the 5149 credentials will be acting as a client or as a server. If 5150 ``verify-peer`` is enabled (the default) then once the handshake 5151 is completed, the peer credentials will be verified, though this 5152 is a no-op for anonymous credentials. 5153 5154 The dir parameter tells QEMU where to find the credential files. 5155 For server endpoints, this directory may contain a file 5156 dh-params.pem providing diffie-hellman parameters to use for the 5157 TLS server. If the file is missing, QEMU will generate a set of 5158 DH parameters at startup. This is a computationally expensive 5159 operation that consumes random pool entropy, so it is 5160 recommended that a persistent set of parameters be generated 5161 upfront and saved. 5162 5163 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]`` 5164 Creates a TLS Pre-Shared Keys (PSK) credentials object, which 5165 can be used to provide TLS support on network backends. The 5166 ``id`` parameter is a unique ID which network backends will use 5167 to access the credentials. The ``endpoint`` is either ``server`` 5168 or ``client`` depending on whether the QEMU network backend that 5169 uses the credentials will be acting as a client or as a server. 5170 For clients only, ``username`` is the username which will be 5171 sent to the server. If omitted it defaults to "qemu". 5172 5173 The dir parameter tells QEMU where to find the keys file. It is 5174 called "dir/keys.psk" and contains "username:key" pairs. This 5175 file can most easily be created using the GnuTLS ``psktool`` 5176 program. 5177 5178 For server endpoints, dir may also contain a file dh-params.pem 5179 providing diffie-hellman parameters to use for the TLS server. 5180 If the file is missing, QEMU will generate a set of DH 5181 parameters at startup. This is a computationally expensive 5182 operation that consumes random pool entropy, so it is 5183 recommended that a persistent set of parameters be generated up 5184 front and saved. 5185 5186 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id`` 5187 Creates a TLS anonymous credentials object, which can be used to 5188 provide TLS support on network backends. The ``id`` parameter is 5189 a unique ID which network backends will use to access the 5190 credentials. The ``endpoint`` is either ``server`` or ``client`` 5191 depending on whether the QEMU network backend that uses the 5192 credentials will be acting as a client or as a server. If 5193 ``verify-peer`` is enabled (the default) then once the handshake 5194 is completed, the peer credentials will be verified. With x509 5195 certificates, this implies that the clients must be provided 5196 with valid client certificates too. 5197 5198 The dir parameter tells QEMU where to find the credential files. 5199 For server endpoints, this directory may contain a file 5200 dh-params.pem providing diffie-hellman parameters to use for the 5201 TLS server. If the file is missing, QEMU will generate a set of 5202 DH parameters at startup. This is a computationally expensive 5203 operation that consumes random pool entropy, so it is 5204 recommended that a persistent set of parameters be generated 5205 upfront and saved. 5206 5207 For x509 certificate credentials the directory will contain 5208 further files providing the x509 certificates. The certificates 5209 must be stored in PEM format, in filenames ca-cert.pem, 5210 ca-crl.pem (optional), server-cert.pem (only servers), 5211 server-key.pem (only servers), client-cert.pem (only clients), 5212 and client-key.pem (only clients). 5213 5214 For the server-key.pem and client-key.pem files which contain 5215 sensitive private keys, it is possible to use an encrypted 5216 version by providing the passwordid parameter. This provides the 5217 ID of a previously created ``secret`` object containing the 5218 password for decryption. 5219 5220 The priority parameter allows to override the global default 5221 priority used by gnutls. This can be useful if the system 5222 administrator needs to use a weaker set of crypto priorities for 5223 QEMU without potentially forcing the weakness onto all 5224 applications. Or conversely if one wants wants a stronger 5225 default for QEMU than for all other applications, they can do 5226 this through this parameter. Its format is a gnutls priority 5227 string as described at 5228 https://gnutls.org/manual/html_node/Priority-Strings.html. 5229 5230 ``-object tls-cipher-suites,id=id,priority=priority`` 5231 Creates a TLS cipher suites object, which can be used to control 5232 the TLS cipher/protocol algorithms that applications are permitted 5233 to use. 5234 5235 The ``id`` parameter is a unique ID which frontends will use to 5236 access the ordered list of permitted TLS cipher suites from the 5237 host. 5238 5239 The ``priority`` parameter allows to override the global default 5240 priority used by gnutls. This can be useful if the system 5241 administrator needs to use a weaker set of crypto priorities for 5242 QEMU without potentially forcing the weakness onto all 5243 applications. Or conversely if one wants wants a stronger 5244 default for QEMU than for all other applications, they can do 5245 this through this parameter. Its format is a gnutls priority 5246 string as described at 5247 https://gnutls.org/manual/html_node/Priority-Strings.html. 5248 5249 An example of use of this object is to control UEFI HTTPS Boot. 5250 The tls-cipher-suites object exposes the ordered list of permitted 5251 TLS cipher suites from the host side to the guest firmware, via 5252 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER 5253 objects. The firmware uses the IANA_TLS_CIPHER array for configuring 5254 guest-side TLS. 5255 5256 In the following example, the priority at which the host-side policy 5257 is retrieved is given by the ``priority`` property. 5258 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to 5259 refer to /etc/crypto-policies/back-ends/gnutls.config. 5260 5261 .. parsed-literal:: 5262 5263 # |qemu_system| \\ 5264 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\ 5265 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 5266 5267 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` 5268 Interval t can't be 0, this filter batches the packet delivery: 5269 all packets arriving in a given interval on netdev netdevid are 5270 delayed until the end of the interval. Interval is in 5271 microseconds. ``status`` is optional that indicate whether the 5272 netfilter is on (enabled) or off (disabled), the default status 5273 for netfilter will be 'on'. 5274 5275 queue all\|rx\|tx is an option that can be applied to any 5276 netfilter. 5277 5278 ``all``: the filter is attached both to the receive and the 5279 transmit queue of the netdev (default). 5280 5281 ``rx``: the filter is attached to the receive queue of the 5282 netdev, where it will receive packets sent to the netdev. 5283 5284 ``tx``: the filter is attached to the transmit queue of the 5285 netdev, where it will receive packets sent by the netdev. 5286 5287 position head\|tail\|id=<id> is an option to specify where the 5288 filter should be inserted in the filter list. It can be applied 5289 to any netfilter. 5290 5291 ``head``: the filter is inserted at the head of the filter list, 5292 before any existing filters. 5293 5294 ``tail``: the filter is inserted at the tail of the filter list, 5295 behind any existing filters (default). 5296 5297 ``id=<id>``: the filter is inserted before or behind the filter 5298 specified by <id>, see the insert option below. 5299 5300 insert behind\|before is an option to specify where to insert 5301 the new filter relative to the one specified with 5302 position=id=<id>. It can be applied to any netfilter. 5303 5304 ``before``: insert before the specified filter. 5305 5306 ``behind``: insert behind the specified filter (default). 5307 5308 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5309 filter-mirror on netdev netdevid,mirror net packet to 5310 chardevchardevid, if it has the vnet\_hdr\_support flag, 5311 filter-mirror will mirror packet with vnet\_hdr\_len. 5312 5313 ``-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]`` 5314 filter-redirector on netdev netdevid,redirect filter's net 5315 packet to chardev chardevid,and redirect indev's packet to 5316 filter.if it has the vnet\_hdr\_support flag, filter-redirector 5317 will redirect packet with vnet\_hdr\_len. Create a 5318 filter-redirector we need to differ outdev id from indev id, id 5319 can not be the same. we can just use indev or outdev, but at 5320 least one of indev or outdev need to be specified. 5321 5322 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5323 Filter-rewriter is a part of COLO project.It will rewrite tcp 5324 packet to secondary from primary to keep secondary tcp 5325 connection,and rewrite tcp packet to primary from secondary make 5326 tcp packet can be handled by client.if it has the 5327 vnet\_hdr\_support flag, we can parse packet with vnet header. 5328 5329 usage: colo secondary: -object 5330 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object 5331 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object 5332 filter-rewriter,id=rew0,netdev=hn0,queue=all 5333 5334 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]`` 5335 Dump the network traffic on netdev dev to the file specified by 5336 filename. At most len bytes (64k by default) per packet are 5337 stored. The file format is libpcap, so it can be analyzed with 5338 tools such as tcpdump or Wireshark. 5339 5340 ``-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}]`` 5341 Colo-compare gets packet from primary\_in chardevid and 5342 secondary\_in, then compare whether the payload of primary packet 5343 and secondary packet are the same. If same, it will output 5344 primary packet to out\_dev, else it will notify COLO-framework to do 5345 checkpoint and send primary packet to out\_dev. In order to 5346 improve efficiency, we need to put the task of comparison in 5347 another iothread. If it has the vnet\_hdr\_support flag, 5348 colo compare will send/recv packet with vnet\_hdr\_len. 5349 The compare\_timeout=@var{ms} determines the maximum time of the 5350 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms} 5351 is to set the period of scanning expired primary node network packets. 5352 The max\_queue\_size=@var{size} is to set the max compare queue 5353 size depend on user environment. 5354 If user want to use Xen COLO, need to add the notify\_dev to 5355 notify Xen colo-frame to do checkpoint. 5356 5357 COLO-compare must be used with the help of filter-mirror, 5358 filter-redirector and filter-rewriter. 5359 5360 :: 5361 5362 KVM COLO 5363 5364 primary: 5365 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5366 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5367 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5368 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5369 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5370 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5371 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5372 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5373 -object iothread,id=iothread1 5374 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5375 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5376 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5377 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 5378 5379 secondary: 5380 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5381 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5382 -chardev socket,id=red0,host=3.3.3.3,port=9003 5383 -chardev socket,id=red1,host=3.3.3.3,port=9004 5384 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5385 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5386 5387 5388 Xen COLO 5389 5390 primary: 5391 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5392 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5393 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5394 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5395 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5396 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5397 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5398 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5399 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off 5400 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5401 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5402 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5403 -object iothread,id=iothread1 5404 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 5405 5406 secondary: 5407 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5408 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5409 -chardev socket,id=red0,host=3.3.3.3,port=9003 5410 -chardev socket,id=red1,host=3.3.3.3,port=9004 5411 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5412 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5413 5414 If you want to know the detail of above command line, you can 5415 read the colo-compare git log. 5416 5417 ``-object cryptodev-backend-builtin,id=id[,queues=queues]`` 5418 Creates a cryptodev backend which executes crypto operations from 5419 the QEMU cipher APIs. The id parameter is a unique ID that will 5420 be used to reference this cryptodev backend from the 5421 ``virtio-crypto`` device. The queues parameter is optional, 5422 which specify the queue number of cryptodev backend, the default 5423 of queues is 1. 5424 5425 .. parsed-literal:: 5426 5427 # |qemu_system| \\ 5428 [...] \\ 5429 -object cryptodev-backend-builtin,id=cryptodev0 \\ 5430 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5431 [...] 5432 5433 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]`` 5434 Creates a vhost-user cryptodev backend, backed by a chardev 5435 chardevid. The id parameter is a unique ID that will be used to 5436 reference this cryptodev backend from the ``virtio-crypto`` 5437 device. The chardev should be a unix domain socket backed one. 5438 The vhost-user uses a specifically defined protocol to pass 5439 vhost ioctl replacement messages to an application on the other 5440 end of the socket. The queues parameter is optional, which 5441 specify the queue number of cryptodev backend for multiqueue 5442 vhost-user, the default of queues is 1. 5443 5444 .. parsed-literal:: 5445 5446 # |qemu_system| \\ 5447 [...] \\ 5448 -chardev socket,id=chardev0,path=/path/to/socket \\ 5449 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\ 5450 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5451 [...] 5452 5453 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]`` 5454 \ 5455 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]`` 5456 Defines a secret to store a password, encryption key, or some 5457 other sensitive data. The sensitive data can either be passed 5458 directly via the data parameter, or indirectly via the file 5459 parameter. Using the data parameter is insecure unless the 5460 sensitive data is encrypted. 5461 5462 The sensitive data can be provided in raw format (the default), 5463 or base64. When encoded as JSON, the raw format only supports 5464 valid UTF-8 characters, so base64 is recommended for sending 5465 binary data. QEMU will convert from which ever format is 5466 provided to the format it needs internally. eg, an RBD password 5467 can be provided in raw format, even though it will be base64 5468 encoded when passed onto the RBD sever. 5469 5470 For added protection, it is possible to encrypt the data 5471 associated with a secret using the AES-256-CBC cipher. Use of 5472 encryption is indicated by providing the keyid and iv 5473 parameters. The keyid parameter provides the ID of a previously 5474 defined secret that contains the AES-256 decryption key. This 5475 key should be 32-bytes long and be base64 encoded. The iv 5476 parameter provides the random initialization vector used for 5477 encryption of this particular secret and should be a base64 5478 encrypted string of the 16-byte IV. 5479 5480 The simplest (insecure) usage is to provide the secret inline 5481 5482 .. parsed-literal:: 5483 5484 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw 5485 5486 The simplest secure usage is to provide the secret via a file 5487 5488 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object 5489 secret,id=sec0,file=mypasswd.txt,format=raw 5490 5491 For greater security, AES-256-CBC should be used. To illustrate 5492 usage, consider the openssl command line tool which can encrypt 5493 the data. Note that when encrypting, the plaintext must be 5494 padded to the cipher block size (32 bytes) using the standard 5495 PKCS#5/6 compatible padding algorithm. 5496 5497 First a master key needs to be created in base64 encoding: 5498 5499 :: 5500 5501 # openssl rand -base64 32 > key.b64 5502 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 5503 5504 Each secret to be encrypted needs to have a random 5505 initialization vector generated. These do not need to be kept 5506 secret 5507 5508 :: 5509 5510 # openssl rand -base64 16 > iv.b64 5511 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 5512 5513 The secret to be defined can now be encrypted, in this case 5514 we're telling openssl to base64 encode the result, but it could 5515 be left as raw bytes if desired. 5516 5517 :: 5518 5519 # SECRET=$(printf "letmein" | 5520 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 5521 5522 When launching QEMU, create a master secret pointing to 5523 ``key.b64`` and specify that to be used to decrypt the user 5524 password. Pass the contents of ``iv.b64`` to the second secret 5525 5526 .. parsed-literal:: 5527 5528 # |qemu_system| \\ 5529 -object secret,id=secmaster0,format=base64,file=key.b64 \\ 5530 -object secret,id=sec0,keyid=secmaster0,format=base64,\\ 5531 data=$SECRET,iv=$(<iv.b64) 5532 5533 ``-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]`` 5534 Create a Secure Encrypted Virtualization (SEV) guest object, 5535 which can be used to provide the guest memory encryption support 5536 on AMD processors. 5537 5538 When memory encryption is enabled, one of the physical address 5539 bit (aka the C-bit) is utilized to mark if a memory page is 5540 protected. The ``cbitpos`` is used to provide the C-bit 5541 position. The C-bit position is Host family dependent hence user 5542 must provide this value. On EPYC, the value should be 47. 5543 5544 When memory encryption is enabled, we loose certain bits in 5545 physical address space. The ``reduced-phys-bits`` is used to 5546 provide the number of bits we loose in physical address space. 5547 Similar to C-bit, the value is Host family dependent. On EPYC, 5548 a guest will lose a maximum of 1 bit, so the value should be 1. 5549 5550 The ``sev-device`` provides the device file to use for 5551 communicating with the SEV firmware running inside AMD Secure 5552 Processor. The default device is '/dev/sev'. If hardware 5553 supports memory encryption then /dev/sev devices are created by 5554 CCP driver. 5555 5556 The ``policy`` provides the guest policy to be enforced by the 5557 SEV firmware and restrict what configuration and operational 5558 commands can be performed on this guest by the hypervisor. The 5559 policy should be provided by the guest owner and is bound to the 5560 guest and cannot be changed throughout the lifetime of the 5561 guest. The default is 0. 5562 5563 If guest ``policy`` allows sharing the key with another SEV 5564 guest then ``handle`` can be use to provide handle of the guest 5565 from which to share the key. 5566 5567 The ``dh-cert-file`` and ``session-file`` provides the guest 5568 owner's Public Diffie-Hillman key defined in SEV spec. The PDH 5569 and session parameters are used for establishing a cryptographic 5570 session with the guest owner to negotiate keys used for 5571 attestation. The file must be encoded in base64. 5572 5573 The ``kernel-hashes`` adds the hashes of given kernel/initrd/ 5574 cmdline to a designated guest firmware page for measured Linux 5575 boot with -kernel. The default is off. (Since 6.2) 5576 5577 e.g to launch a SEV guest 5578 5579 .. parsed-literal:: 5580 5581 # |qemu_system_x86| \\ 5582 ...... \\ 5583 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \\ 5584 -machine ...,memory-encryption=sev0 \\ 5585 ..... 5586 5587 ``-object authz-simple,id=id,identity=string`` 5588 Create an authorization object that will control access to 5589 network services. 5590 5591 The ``identity`` parameter is identifies the user and its format 5592 depends on the network service that authorization object is 5593 associated with. For authorizing based on TLS x509 certificates, 5594 the identity must be the x509 distinguished name. Note that care 5595 must be taken to escape any commas in the distinguished name. 5596 5597 An example authorization object to validate a x509 distinguished 5598 name would look like: 5599 5600 .. parsed-literal:: 5601 5602 # |qemu_system| \\ 5603 ... \\ 5604 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\ 5605 ... 5606 5607 Note the use of quotes due to the x509 distinguished name 5608 containing whitespace, and escaping of ','. 5609 5610 ``-object authz-listfile,id=id,filename=path,refresh=on|off`` 5611 Create an authorization object that will control access to 5612 network services. 5613 5614 The ``filename`` parameter is the fully qualified path to a file 5615 containing the access control list rules in JSON format. 5616 5617 An example set of rules that match against SASL usernames might 5618 look like: 5619 5620 :: 5621 5622 { 5623 "rules": [ 5624 { "match": "fred", "policy": "allow", "format": "exact" }, 5625 { "match": "bob", "policy": "allow", "format": "exact" }, 5626 { "match": "danb", "policy": "deny", "format": "glob" }, 5627 { "match": "dan*", "policy": "allow", "format": "exact" }, 5628 ], 5629 "policy": "deny" 5630 } 5631 5632 When checking access the object will iterate over all the rules 5633 and the first rule to match will have its ``policy`` value 5634 returned as the result. If no rules match, then the default 5635 ``policy`` value is returned. 5636 5637 The rules can either be an exact string match, or they can use 5638 the simple UNIX glob pattern matching to allow wildcards to be 5639 used. 5640 5641 If ``refresh`` is set to true the file will be monitored and 5642 automatically reloaded whenever its content changes. 5643 5644 As with the ``authz-simple`` object, the format of the identity 5645 strings being matched depends on the network service, but is 5646 usually a TLS x509 distinguished name, or a SASL username. 5647 5648 An example authorization object to validate a SASL username 5649 would look like: 5650 5651 .. parsed-literal:: 5652 5653 # |qemu_system| \\ 5654 ... \\ 5655 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\ 5656 ... 5657 5658 ``-object authz-pam,id=id,service=string`` 5659 Create an authorization object that will control access to 5660 network services. 5661 5662 The ``service`` parameter provides the name of a PAM service to 5663 use for authorization. It requires that a file 5664 ``/etc/pam.d/service`` exist to provide the configuration for 5665 the ``account`` subsystem. 5666 5667 An example authorization object to validate a TLS x509 5668 distinguished name would look like: 5669 5670 .. parsed-literal:: 5671 5672 # |qemu_system| \\ 5673 ... \\ 5674 -object authz-pam,id=auth0,service=qemu-vnc \\ 5675 ... 5676 5677 There would then be a corresponding config file for PAM at 5678 ``/etc/pam.d/qemu-vnc`` that contains: 5679 5680 :: 5681 5682 account requisite pam_listfile.so item=user sense=allow \ 5683 file=/etc/qemu/vnc.allow 5684 5685 Finally the ``/etc/qemu/vnc.allow`` file would contain the list 5686 of x509 distinguished names that are permitted access 5687 5688 :: 5689 5690 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 5691 5692 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch`` 5693 Creates a dedicated event loop thread that devices can be 5694 assigned to. This is known as an IOThread. By default device 5695 emulation happens in vCPU threads or the main event loop thread. 5696 This can become a scalability bottleneck. IOThreads allow device 5697 emulation and I/O to run on other host CPUs. 5698 5699 The ``id`` parameter is a unique ID that will be used to 5700 reference this IOThread from ``-device ...,iothread=id``. 5701 Multiple devices can be assigned to an IOThread. Note that not 5702 all devices support an ``iothread`` parameter. 5703 5704 The ``query-iothreads`` QMP command lists IOThreads and reports 5705 their thread IDs so that the user can configure host CPU 5706 pinning/affinity. 5707 5708 IOThreads use an adaptive polling algorithm to reduce event loop 5709 latency. Instead of entering a blocking system call to monitor 5710 file descriptors and then pay the cost of being woken up when an 5711 event occurs, the polling algorithm spins waiting for events for 5712 a short time. The algorithm's default parameters are suitable 5713 for many cases but can be adjusted based on knowledge of the 5714 workload and/or host device latency. 5715 5716 The ``poll-max-ns`` parameter is the maximum number of 5717 nanoseconds to busy wait for events. Polling can be disabled by 5718 setting this value to 0. 5719 5720 The ``poll-grow`` parameter is the multiplier used to increase 5721 the polling time when the algorithm detects it is missing events 5722 due to not polling long enough. 5723 5724 The ``poll-shrink`` parameter is the divisor used to decrease 5725 the polling time when the algorithm detects it is spending too 5726 long polling without encountering events. 5727 5728 The ``aio-max-batch`` parameter is the maximum number of requests 5729 in a batch for the AIO engine, 0 means that the engine will use 5730 its default. 5731 5732 The IOThread parameters can be modified at run-time using the 5733 ``qom-set`` command (where ``iothread1`` is the IOThread's 5734 ``id``): 5735 5736 :: 5737 5738 (qemu) qom-set /objects/iothread1 poll-max-ns 100000 5739ERST 5740 5741 5742HXCOMM This is the last statement. Insert new options before this line! 5743 5744#undef DEF 5745#undef DEFHEADING 5746#undef ARCHHEADING 5747
