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][,drawers=drawers][,books=books][,sockets=sockets]\n" 276 " [,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]\n" 277 " set the number of initial CPUs to 'n' [default=1]\n" 278 " maxcpus= maximum number of total CPUs, including\n" 279 " offline CPUs for hotplug, etc\n" 280 " drawers= number of drawers on the machine board\n" 281 " books= number of books in one drawer\n" 282 " sockets= number of sockets in one book\n" 283 " dies= number of dies in one socket\n" 284 " clusters= number of clusters in one die\n" 285 " cores= number of cores in one cluster\n" 286 " threads= number of threads in one core\n" 287 "Note: Different machines may have different subsets of the CPU topology\n" 288 " parameters supported, so the actual meaning of the supported parameters\n" 289 " will vary accordingly. For example, for a machine type that supports a\n" 290 " three-level CPU hierarchy of sockets/cores/threads, the parameters will\n" 291 " sequentially mean as below:\n" 292 " sockets means the number of sockets on the machine board\n" 293 " cores means the number of cores in one socket\n" 294 " threads means the number of threads in one core\n" 295 " For a particular machine type board, an expected CPU topology hierarchy\n" 296 " can be defined through the supported sub-option. Unsupported parameters\n" 297 " can also be provided in addition to the sub-option, but their values\n" 298 " must be set as 1 in the purpose of correct parsing.\n", 299 QEMU_ARCH_ALL) 300SRST 301``-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]`` 302 Simulate a SMP system with '\ ``n``\ ' CPUs initially present on 303 the machine type board. On boards supporting CPU hotplug, the optional 304 '\ ``maxcpus``\ ' parameter can be set to enable further CPUs to be 305 added at runtime. When both parameters are omitted, the maximum number 306 of CPUs will be calculated from the provided topology members and the 307 initial CPU count will match the maximum number. When only one of them 308 is given then the omitted one will be set to its counterpart's value. 309 Both parameters may be specified, but the maximum number of CPUs must 310 be equal to or greater than the initial CPU count. Product of the 311 CPU topology hierarchy must be equal to the maximum number of CPUs. 312 Both parameters are subject to an upper limit that is determined by 313 the specific machine type chosen. 314 315 To control reporting of CPU topology information, values of the topology 316 parameters can be specified. Machines may only support a subset of the 317 parameters and different machines may have different subsets supported 318 which vary depending on capacity of the corresponding CPU targets. So 319 for a particular machine type board, an expected topology hierarchy can 320 be defined through the supported sub-option. Unsupported parameters can 321 also be provided in addition to the sub-option, but their values must be 322 set as 1 in the purpose of correct parsing. 323 324 Either the initial CPU count, or at least one of the topology parameters 325 must be specified. The specified parameters must be greater than zero, 326 explicit configuration like "cpus=0" is not allowed. Values for any 327 omitted parameters will be computed from those which are given. 328 329 For example, the following sub-option defines a CPU topology hierarchy 330 (2 sockets totally on the machine, 2 cores per socket, 2 threads per 331 core) for a machine that only supports sockets/cores/threads. 332 Some members of the option can be omitted but their values will be 333 automatically computed: 334 335 :: 336 337 -smp 8,sockets=2,cores=2,threads=2,maxcpus=8 338 339 The following sub-option defines a CPU topology hierarchy (2 sockets 340 totally on the machine, 2 dies per socket, 2 cores per die, 2 threads 341 per core) for PC machines which support sockets/dies/cores/threads. 342 Some members of the option can be omitted but their values will be 343 automatically computed: 344 345 :: 346 347 -smp 16,sockets=2,dies=2,cores=2,threads=2,maxcpus=16 348 349 The following sub-option defines a CPU topology hierarchy (2 sockets 350 totally on the machine, 2 clusters per socket, 2 cores per cluster, 351 2 threads per core) for ARM virt machines which support sockets/clusters 352 /cores/threads. Some members of the option can be omitted but their values 353 will be automatically computed: 354 355 :: 356 357 -smp 16,sockets=2,clusters=2,cores=2,threads=2,maxcpus=16 358 359 Historically preference was given to the coarsest topology parameters 360 when computing missing values (ie sockets preferred over cores, which 361 were preferred over threads), however, this behaviour is considered 362 liable to change. Prior to 6.2 the preference was sockets over cores 363 over threads. Since 6.2 the preference is cores over sockets over threads. 364 365 For example, the following option defines a machine board with 2 sockets 366 of 1 core before 6.2 and 1 socket of 2 cores after 6.2: 367 368 :: 369 370 -smp 2 371 372 Note: The cluster topology will only be generated in ACPI and exposed 373 to guest if it's explicitly specified in -smp. 374ERST 375 376DEF("numa", HAS_ARG, QEMU_OPTION_numa, 377 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 378 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 379 "-numa dist,src=source,dst=destination,val=distance\n" 380 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n" 381 "-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" 382 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n", 383 QEMU_ARCH_ALL) 384SRST 385``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 386 \ 387``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 388 \ 389``-numa dist,src=source,dst=destination,val=distance`` 390 \ 391``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]`` 392 \ 393``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=type[,latency=lat][,bandwidth=bw]`` 394 \ 395``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]`` 396 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA 397 distance from a source node to a destination node. Set the ACPI 398 Heterogeneous Memory Attributes for the given nodes. 399 400 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and 401 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a 402 contiguous range of CPU indexes (or a single VCPU if lastcpu is 403 omitted). A non-contiguous set of VCPUs can be represented by 404 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is 405 omitted on all nodes, VCPUs are automatically split between them. 406 407 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a 408 NUMA node: 409 410 :: 411 412 -numa node,cpus=0-2,cpus=5 413 414 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option 415 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to 416 assign CPU objects to a node using topology layout properties of 417 CPU. The set of properties is machine specific, and depends on used 418 machine type/'\ ``smp``\ ' options. It could be queried with 419 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ ' 420 property specifies node to which CPU object will be assigned, it's 421 required for node to be declared with '\ ``node``\ ' option before 422 it's used with '\ ``cpu``\ ' option. 423 424 For example: 425 426 :: 427 428 -M pc \ 429 -smp 1,sockets=2,maxcpus=2 \ 430 -numa node,nodeid=0 -numa node,nodeid=1 \ 431 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 432 433 '\ ``memdev``\ ' option assigns RAM from a given memory backend 434 device to a node. It is recommended to use '\ ``memdev``\ ' option 435 over legacy '\ ``mem``\ ' option. This is because '\ ``memdev``\ ' 436 option provides better performance and more control over the 437 backend's RAM (e.g. '\ ``prealloc``\ ' parameter of 438 '\ ``-memory-backend-ram``\ ' allows memory preallocation). 439 440 For compatibility reasons, legacy '\ ``mem``\ ' option is 441 supported in 5.0 and older machine types. Note that '\ ``mem``\ ' 442 and '\ ``memdev``\ ' are mutually exclusive. If one node uses 443 '\ ``memdev``\ ', the rest nodes have to use '\ ``memdev``\ ' 444 option, and vice versa. 445 446 Users must specify memory for all NUMA nodes by '\ ``memdev``\ ' 447 (or legacy '\ ``mem``\ ' if available). In QEMU 5.2, the support 448 for '\ ``-numa node``\ ' without memory specified was removed. 449 450 '\ ``initiator``\ ' is an additional option that points to an 451 initiator NUMA node that has best performance (the lowest latency or 452 largest bandwidth) to this NUMA node. Note that this option can be 453 set only when the machine property 'hmat' is set to 'on'. 454 455 Following example creates a machine with 2 NUMA nodes, node 0 has 456 CPU. node 1 has only memory, and its initiator is node 0. Note that 457 because node 0 has CPU, by default the initiator of node 0 is itself 458 and must be itself. 459 460 :: 461 462 -machine hmat=on \ 463 -m 2G,slots=2,maxmem=4G \ 464 -object memory-backend-ram,size=1G,id=m0 \ 465 -object memory-backend-ram,size=1G,id=m1 \ 466 -numa node,nodeid=0,memdev=m0 \ 467 -numa node,nodeid=1,memdev=m1,initiator=0 \ 468 -smp 2,sockets=2,maxcpus=2 \ 469 -numa cpu,node-id=0,socket-id=0 \ 470 -numa cpu,node-id=0,socket-id=1 471 472 source and destination are NUMA node IDs. distance is the NUMA 473 distance from source to destination. The distance from a node to 474 itself is always 10. If any pair of nodes is given a distance, then 475 all pairs must be given distances. Although, when distances are only 476 given in one direction for each pair of nodes, then the distances in 477 the opposite directions are assumed to be the same. If, however, an 478 asymmetrical pair of distances is given for even one node pair, then 479 all node pairs must be provided distance values for both directions, 480 even when they are symmetrical. When a node is unreachable from 481 another node, set the pair's distance to 255. 482 483 Note that the -``numa`` option doesn't allocate any of the specified 484 resources, it just assigns existing resources to NUMA nodes. This 485 means that one still has to use the ``-m``, ``-smp`` options to 486 allocate RAM and VCPUs respectively. 487 488 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth 489 Information between initiator and target NUMA nodes in ACPI 490 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can 491 create memory requests, usually it has one or more processors. 492 Target NUMA node contains addressable memory. 493 494 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is 495 the memory hierarchy of the target NUMA node: if hierarchy is 496 'memory', the structure represents the memory performance; if 497 hierarchy is 'first-level\|second-level\|third-level', this 498 structure represents aggregated performance of memory side caches 499 for each domain. type of 'data-type' is type of data represented by 500 this structure instance: if 'hierarchy' is 'memory', 'data-type' is 501 'access\|read\|write' latency or 'access\|read\|write' bandwidth of 502 the target memory; if 'hierarchy' is 503 'first-level\|second-level\|third-level', 'data-type' is 504 'access\|read\|write' hit latency or 'access\|read\|write' hit 505 bandwidth of the target memory side cache. 506 507 lat is latency value in nanoseconds. bw is bandwidth value, the 508 possible value and units are NUM[M\|G\|T], mean that the bandwidth 509 value are NUM byte per second (or MB/s, GB/s or TB/s depending on 510 used suffix). Note that if latency or bandwidth value is 0, means 511 the corresponding latency or bandwidth information is not provided. 512 513 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory 514 belongs. size is the size of memory side cache in bytes. level is 515 the cache level described in this structure, note that the cache 516 level 0 should not be used with '\ ``hmat-cache``\ ' option. 517 associativity is the cache associativity, the possible value is 518 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy 519 is the write policy. line is the cache Line size in bytes. 520 521 For example, the following options describe 2 NUMA nodes. Node 0 has 522 2 cpus and a ram, node 1 has only a ram. The processors in node 0 523 access memory in node 0 with access-latency 5 nanoseconds, 524 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access 525 memory in NUMA node 1 with access-latency 10 nanoseconds, 526 access-bandwidth is 100 MB/s. And for memory side cache information, 527 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB, 528 policy is write-back, the cache Line size is 8 bytes: 529 530 :: 531 532 -machine hmat=on \ 533 -m 2G \ 534 -object memory-backend-ram,size=1G,id=m0 \ 535 -object memory-backend-ram,size=1G,id=m1 \ 536 -smp 2,sockets=2,maxcpus=2 \ 537 -numa node,nodeid=0,memdev=m0 \ 538 -numa node,nodeid=1,memdev=m1,initiator=0 \ 539 -numa cpu,node-id=0,socket-id=0 \ 540 -numa cpu,node-id=0,socket-id=1 \ 541 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \ 542 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \ 543 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \ 544 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \ 545 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \ 546 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8 547ERST 548 549DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 550 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 551 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 552SRST 553``-add-fd fd=fd,set=set[,opaque=opaque]`` 554 Add a file descriptor to an fd set. Valid options are: 555 556 ``fd=fd`` 557 This option defines the file descriptor of which a duplicate is 558 added to fd set. The file descriptor cannot be stdin, stdout, or 559 stderr. 560 561 ``set=set`` 562 This option defines the ID of the fd set to add the file 563 descriptor to. 564 565 ``opaque=opaque`` 566 This option defines a free-form string that can be used to 567 describe fd. 568 569 You can open an image using pre-opened file descriptors from an fd 570 set: 571 572 .. parsed-literal:: 573 574 |qemu_system| \\ 575 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 576 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 577 -drive file=/dev/fdset/2,index=0,media=disk 578ERST 579 580DEF("set", HAS_ARG, QEMU_OPTION_set, 581 "-set group.id.arg=value\n" 582 " set <arg> parameter for item <id> of type <group>\n" 583 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 584SRST 585``-set group.id.arg=value`` 586 Set parameter arg for item id of type group 587ERST 588 589DEF("global", HAS_ARG, QEMU_OPTION_global, 590 "-global driver.property=value\n" 591 "-global driver=driver,property=property,value=value\n" 592 " set a global default for a driver property\n", 593 QEMU_ARCH_ALL) 594SRST 595``-global driver.prop=value`` 596 \ 597``-global driver=driver,property=property,value=value`` 598 Set default value of driver's property prop to value, e.g.: 599 600 .. parsed-literal:: 601 602 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img 603 604 In particular, you can use this to set driver properties for devices 605 which are created automatically by the machine model. To create a 606 device which is not created automatically and set properties on it, 607 use -``device``. 608 609 -global driver.prop=value is shorthand for -global 610 driver=driver,property=prop,value=value. The longhand syntax works 611 even when driver contains a dot. 612ERST 613 614DEF("boot", HAS_ARG, QEMU_OPTION_boot, 615 "-boot [order=drives][,once=drives][,menu=on|off]\n" 616 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 617 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 618 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 619 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 620 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 621 QEMU_ARCH_ALL) 622SRST 623``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]`` 624 Specify boot order drives as a string of drive letters. Valid drive 625 letters depend on the target architecture. The x86 PC uses: a, b 626 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p 627 (Etherboot from network adapter 1-4), hard disk boot is the default. 628 To apply a particular boot order only on the first startup, specify 629 it via ``once``. Note that the ``order`` or ``once`` parameter 630 should not be used together with the ``bootindex`` property of 631 devices, since the firmware implementations normally do not support 632 both at the same time. 633 634 Interactive boot menus/prompts can be enabled via ``menu=on`` as far 635 as firmware/BIOS supports them. The default is non-interactive boot. 636 637 A splash picture could be passed to bios, enabling user to show it 638 as logo, when option splash=sp\_name is given and menu=on, If 639 firmware/BIOS supports them. Currently Seabios for X86 system 640 support it. limitation: The splash file could be a jpeg file or a 641 BMP file in 24 BPP format(true color). The resolution should be 642 supported by the SVGA mode, so the recommended is 320x240, 640x480, 643 800x640. 644 645 A timeout could be passed to bios, guest will pause for rb\_timeout 646 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will 647 not reboot, qemu passes '-1' to bios by default. Currently Seabios 648 for X86 system support it. 649 650 Do strict boot via ``strict=on`` as far as firmware/BIOS supports 651 it. This only effects when boot priority is changed by bootindex 652 options. The default is non-strict boot. 653 654 .. parsed-literal:: 655 656 # try to boot from network first, then from hard disk 657 |qemu_system_x86| -boot order=nc 658 # boot from CD-ROM first, switch back to default order after reboot 659 |qemu_system_x86| -boot once=d 660 # boot with a splash picture for 5 seconds. 661 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000 662 663 Note: The legacy format '-boot drives' is still supported but its 664 use is discouraged as it may be removed from future versions. 665ERST 666 667DEF("m", HAS_ARG, QEMU_OPTION_m, 668 "-m [size=]megs[,slots=n,maxmem=size]\n" 669 " configure guest RAM\n" 670 " size: initial amount of guest memory\n" 671 " slots: number of hotplug slots (default: none)\n" 672 " maxmem: maximum amount of guest memory (default: none)\n" 673 " Note: Some architectures might enforce a specific granularity\n", 674 QEMU_ARCH_ALL) 675SRST 676``-m [size=]megs[,slots=n,maxmem=size]`` 677 Sets guest startup RAM size to megs megabytes. Default is 128 MiB. 678 Optionally, a suffix of "M" or "G" can be used to signify a value in 679 megabytes or gigabytes respectively. Optional pair slots, maxmem 680 could be used to set amount of hotpluggable memory slots and maximum 681 amount of memory. Note that maxmem must be aligned to the page size. 682 683 For example, the following command-line sets the guest startup RAM 684 size to 1GB, creates 3 slots to hotplug additional memory and sets 685 the maximum memory the guest can reach to 4GB: 686 687 .. parsed-literal:: 688 689 |qemu_system| -m 1G,slots=3,maxmem=4G 690 691 If slots and maxmem are not specified, memory hotplug won't be 692 enabled and the guest startup RAM will never increase. 693ERST 694 695DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 696 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 697SRST 698``-mem-path path`` 699 Allocate guest RAM from a temporarily created file in path. 700ERST 701 702DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 703 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 704 QEMU_ARCH_ALL) 705SRST 706``-mem-prealloc`` 707 Preallocate memory when using -mem-path. 708ERST 709 710DEF("k", HAS_ARG, QEMU_OPTION_k, 711 "-k language use keyboard layout (for example 'fr' for French)\n", 712 QEMU_ARCH_ALL) 713SRST 714``-k language`` 715 Use keyboard layout language (for example ``fr`` for French). This 716 option is only needed where it is not easy to get raw PC keycodes 717 (e.g. on Macs, with some X11 servers or with a VNC or curses 718 display). You don't normally need to use it on PC/Linux or 719 PC/Windows hosts. 720 721 The available layouts are: 722 723 :: 724 725 ar de-ch es fo fr-ca hu ja mk no pt-br sv 726 da en-gb et fr fr-ch is lt nl pl ru th 727 de en-us fi fr-be hr it lv nl-be pt sl tr 728 729 The default is ``en-us``. 730ERST 731 732 733DEF("audio", HAS_ARG, QEMU_OPTION_audio, 734 "-audio [driver=]driver[,prop[=value][,...]]\n" 735 " specifies default audio backend when `audiodev` is not\n" 736 " used to create a machine or sound device;" 737 " options are the same as for -audiodev\n" 738 "-audio [driver=]driver,model=value[,prop[=value][,...]]\n" 739 " specifies the audio backend and device to use;\n" 740 " apart from 'model', options are the same as for -audiodev.\n" 741 " use '-audio model=help' to show possible devices.\n", 742 QEMU_ARCH_ALL) 743SRST 744``-audio [driver=]driver[,model=value][,prop[=value][,...]]`` 745 If the ``model`` option is specified, ``-audio`` is a shortcut 746 for configuring both the guest audio hardware and the host audio 747 backend in one go. The guest hardware model can be set with 748 ``model=modelname``. Use ``model=help`` to list the available 749 device types. 750 751 The following two example do exactly the same, to show how ``-audio`` 752 can be used to shorten the command line length: 753 754 .. parsed-literal:: 755 756 |qemu_system| -audiodev pa,id=pa -device sb16,audiodev=pa 757 |qemu_system| -audio pa,model=sb16 758 759 If the ``model`` option is not specified, ``-audio`` is used to 760 configure a default audio backend that will be used whenever the 761 ``audiodev`` property is not set on a device or machine. In 762 particular, ``-audio none`` ensures that no audio is produced even 763 for machines that have embedded sound hardware. 764 765 In both cases, the driver option is the same as with the corresponding 766 ``-audiodev`` option below. Use ``driver=help`` to list the available 767 drivers. 768 769ERST 770 771DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 772 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 773 " specifies the audio backend to use\n" 774 " Use ``-audiodev help`` to list the available drivers\n" 775 " id= identifier of the backend\n" 776 " timer-period= timer period in microseconds\n" 777 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 778 " in|out.fixed-settings= use fixed settings for host audio\n" 779 " in|out.frequency= frequency to use with fixed settings\n" 780 " in|out.channels= number of channels to use with fixed settings\n" 781 " in|out.format= sample format to use with fixed settings\n" 782 " valid values: s8, s16, s32, u8, u16, u32, f32\n" 783 " in|out.voices= number of voices to use\n" 784 " in|out.buffer-length= length of buffer in microseconds\n" 785 "-audiodev none,id=id,[,prop[=value][,...]]\n" 786 " dummy driver that discards all output\n" 787#ifdef CONFIG_AUDIO_ALSA 788 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 789 " in|out.dev= name of the audio device to use\n" 790 " in|out.period-length= length of period in microseconds\n" 791 " in|out.try-poll= attempt to use poll mode\n" 792 " threshold= threshold (in microseconds) when playback starts\n" 793#endif 794#ifdef CONFIG_AUDIO_COREAUDIO 795 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 796 " in|out.buffer-count= number of buffers\n" 797#endif 798#ifdef CONFIG_AUDIO_DSOUND 799 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 800 " latency= add extra latency to playback in microseconds\n" 801#endif 802#ifdef CONFIG_AUDIO_OSS 803 "-audiodev oss,id=id[,prop[=value][,...]]\n" 804 " in|out.dev= path of the audio device to use\n" 805 " in|out.buffer-count= number of buffers\n" 806 " in|out.try-poll= attempt to use poll mode\n" 807 " try-mmap= try using memory mapped access\n" 808 " exclusive= open device in exclusive mode\n" 809 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 810#endif 811#ifdef CONFIG_AUDIO_PA 812 "-audiodev pa,id=id[,prop[=value][,...]]\n" 813 " server= PulseAudio server address\n" 814 " in|out.name= source/sink device name\n" 815 " in|out.latency= desired latency in microseconds\n" 816#endif 817#ifdef CONFIG_AUDIO_PIPEWIRE 818 "-audiodev pipewire,id=id[,prop[=value][,...]]\n" 819 " in|out.name= source/sink device name\n" 820 " in|out.stream-name= name of pipewire stream\n" 821 " in|out.latency= desired latency in microseconds\n" 822#endif 823#ifdef CONFIG_AUDIO_SDL 824 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 825 " in|out.buffer-count= number of buffers\n" 826#endif 827#ifdef CONFIG_AUDIO_SNDIO 828 "-audiodev sndio,id=id[,prop[=value][,...]]\n" 829#endif 830#ifdef CONFIG_SPICE 831 "-audiodev spice,id=id[,prop[=value][,...]]\n" 832#endif 833#ifdef CONFIG_DBUS_DISPLAY 834 "-audiodev dbus,id=id[,prop[=value][,...]]\n" 835#endif 836 "-audiodev wav,id=id[,prop[=value][,...]]\n" 837 " path= path of wav file to record\n", 838 QEMU_ARCH_ALL) 839SRST 840``-audiodev [driver=]driver,id=id[,prop[=value][,...]]`` 841 Adds a new audio backend driver identified by id. There are global 842 and driver specific properties. Some values can be set differently 843 for input and output, they're marked with ``in|out.``. You can set 844 the input's property with ``in.prop`` and the output's property with 845 ``out.prop``. For example: 846 847 :: 848 849 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 850 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 851 852 NOTE: parameter validation is known to be incomplete, in many cases 853 specifying an invalid option causes QEMU to print an error message 854 and continue emulation without sound. 855 856 Valid global options are: 857 858 ``id=identifier`` 859 Identifies the audio backend. 860 861 ``timer-period=period`` 862 Sets the timer period used by the audio subsystem in 863 microseconds. Default is 10000 (10 ms). 864 865 ``in|out.mixing-engine=on|off`` 866 Use QEMU's mixing engine to mix all streams inside QEMU and 867 convert audio formats when not supported by the backend. When 868 off, fixed-settings must be off too. Note that disabling this 869 option means that the selected backend must support multiple 870 streams and the audio formats used by the virtual cards, 871 otherwise you'll get no sound. It's not recommended to disable 872 this option unless you want to use 5.1 or 7.1 audio, as mixing 873 engine only supports mono and stereo audio. Default is on. 874 875 ``in|out.fixed-settings=on|off`` 876 Use fixed settings for host audio. When off, it will change 877 based on how the guest opens the sound card. In this case you 878 must not specify frequency, channels or format. Default is on. 879 880 ``in|out.frequency=frequency`` 881 Specify the frequency to use when using fixed-settings. Default 882 is 44100Hz. 883 884 ``in|out.channels=channels`` 885 Specify the number of channels to use when using fixed-settings. 886 Default is 2 (stereo). 887 888 ``in|out.format=format`` 889 Specify the sample format to use when using fixed-settings. 890 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``, 891 ``u32``, ``f32``. Default is ``s16``. 892 893 ``in|out.voices=voices`` 894 Specify the number of voices to use. Default is 1. 895 896 ``in|out.buffer-length=usecs`` 897 Sets the size of the buffer in microseconds. 898 899``-audiodev none,id=id[,prop[=value][,...]]`` 900 Creates a dummy backend that discards all outputs. This backend has 901 no backend specific properties. 902 903``-audiodev alsa,id=id[,prop[=value][,...]]`` 904 Creates backend using the ALSA. This backend is only available on 905 Linux. 906 907 ALSA specific options are: 908 909 ``in|out.dev=device`` 910 Specify the ALSA device to use for input and/or output. Default 911 is ``default``. 912 913 ``in|out.period-length=usecs`` 914 Sets the period length in microseconds. 915 916 ``in|out.try-poll=on|off`` 917 Attempt to use poll mode with the device. Default is on. 918 919 ``threshold=threshold`` 920 Threshold (in microseconds) when playback starts. Default is 0. 921 922``-audiodev coreaudio,id=id[,prop[=value][,...]]`` 923 Creates a backend using Apple's Core Audio. This backend is only 924 available on Mac OS and only supports playback. 925 926 Core Audio specific options are: 927 928 ``in|out.buffer-count=count`` 929 Sets the count of the buffers. 930 931``-audiodev dsound,id=id[,prop[=value][,...]]`` 932 Creates a backend using Microsoft's DirectSound. This backend is 933 only available on Windows and only supports playback. 934 935 DirectSound specific options are: 936 937 ``latency=usecs`` 938 Add extra usecs microseconds latency to playback. Default is 939 10000 (10 ms). 940 941``-audiodev oss,id=id[,prop[=value][,...]]`` 942 Creates a backend using OSS. This backend is available on most 943 Unix-like systems. 944 945 OSS specific options are: 946 947 ``in|out.dev=device`` 948 Specify the file name of the OSS device to use. Default is 949 ``/dev/dsp``. 950 951 ``in|out.buffer-count=count`` 952 Sets the count of the buffers. 953 954 ``in|out.try-poll=on|of`` 955 Attempt to use poll mode with the device. Default is on. 956 957 ``try-mmap=on|off`` 958 Try using memory mapped device access. Default is off. 959 960 ``exclusive=on|off`` 961 Open the device in exclusive mode (vmix won't work in this 962 case). Default is off. 963 964 ``dsp-policy=policy`` 965 Sets the timing policy (between 0 and 10, where smaller number 966 means smaller latency but higher CPU usage). Use -1 to use 967 buffer sizes specified by ``buffer`` and ``buffer-count``. This 968 option is ignored if you do not have OSS 4. Default is 5. 969 970``-audiodev pa,id=id[,prop[=value][,...]]`` 971 Creates a backend using PulseAudio. This backend is available on 972 most systems. 973 974 PulseAudio specific options are: 975 976 ``server=server`` 977 Sets the PulseAudio server to connect to. 978 979 ``in|out.name=sink`` 980 Use the specified source/sink for recording/playback. 981 982 ``in|out.latency=usecs`` 983 Desired latency in microseconds. The PulseAudio server will try 984 to honor this value but actual latencies may be lower or higher. 985 986``-audiodev pipewire,id=id[,prop[=value][,...]]`` 987 Creates a backend using PipeWire. This backend is available on 988 most systems. 989 990 PipeWire specific options are: 991 992 ``in|out.latency=usecs`` 993 Desired latency in microseconds. 994 995 ``in|out.name=sink`` 996 Use the specified source/sink for recording/playback. 997 998 ``in|out.stream-name`` 999 Specify the name of pipewire stream. 1000 1001``-audiodev sdl,id=id[,prop[=value][,...]]`` 1002 Creates a backend using SDL. This backend is available on most 1003 systems, but you should use your platform's native backend if 1004 possible. 1005 1006 SDL specific options are: 1007 1008 ``in|out.buffer-count=count`` 1009 Sets the count of the buffers. 1010 1011``-audiodev sndio,id=id[,prop[=value][,...]]`` 1012 Creates a backend using SNDIO. This backend is available on 1013 OpenBSD and most other Unix-like systems. 1014 1015 Sndio specific options are: 1016 1017 ``in|out.dev=device`` 1018 Specify the sndio device to use for input and/or output. Default 1019 is ``default``. 1020 1021 ``in|out.latency=usecs`` 1022 Sets the desired period length in microseconds. 1023 1024``-audiodev spice,id=id[,prop[=value][,...]]`` 1025 Creates a backend that sends audio through SPICE. This backend 1026 requires ``-spice`` and automatically selected in that case, so 1027 usually you can ignore this option. This backend has no backend 1028 specific properties. 1029 1030``-audiodev wav,id=id[,prop[=value][,...]]`` 1031 Creates a backend that writes audio to a WAV file. 1032 1033 Backend specific options are: 1034 1035 ``path=path`` 1036 Write recorded audio into the specified file. Default is 1037 ``qemu.wav``. 1038ERST 1039 1040DEF("device", HAS_ARG, QEMU_OPTION_device, 1041 "-device driver[,prop[=value][,...]]\n" 1042 " add device (based on driver)\n" 1043 " prop=value,... sets driver properties\n" 1044 " use '-device help' to print all possible drivers\n" 1045 " use '-device driver,help' to print all possible properties\n", 1046 QEMU_ARCH_ALL) 1047SRST 1048``-device driver[,prop[=value][,...]]`` 1049 Add device driver. prop=value sets driver properties. Valid 1050 properties depend on the driver. To get help on possible drivers and 1051 properties, use ``-device help`` and ``-device driver,help``. 1052 1053 Some drivers are: 1054 1055``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]`` 1056 Add an IPMI BMC. This is a simulation of a hardware management 1057 interface processor that normally sits on a system. It provides a 1058 watchdog and the ability to reset and power control the system. You 1059 need to connect this to an IPMI interface to make it useful 1060 1061 The IPMI slave address to use for the BMC. The default is 0x20. This 1062 address is the BMC's address on the I2C network of management 1063 controllers. If you don't know what this means, it is safe to ignore 1064 it. 1065 1066 ``id=id`` 1067 The BMC id for interfaces to use this device. 1068 1069 ``slave_addr=val`` 1070 Define slave address to use for the BMC. The default is 0x20. 1071 1072 ``sdrfile=file`` 1073 file containing raw Sensor Data Records (SDR) data. The default 1074 is none. 1075 1076 ``fruareasize=val`` 1077 size of a Field Replaceable Unit (FRU) area. The default is 1078 1024. 1079 1080 ``frudatafile=file`` 1081 file containing raw Field Replaceable Unit (FRU) inventory data. 1082 The default is none. 1083 1084 ``guid=uuid`` 1085 value for the GUID for the BMC, in standard UUID format. If this 1086 is set, get "Get GUID" command to the BMC will return it. 1087 Otherwise "Get GUID" will return an error. 1088 1089``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]`` 1090 Add a connection to an external IPMI BMC simulator. Instead of 1091 locally emulating the BMC like the above item, instead connect to an 1092 external entity that provides the IPMI services. 1093 1094 A connection is made to an external BMC simulator. If you do this, 1095 it is strongly recommended that you use the "reconnect=" chardev 1096 option to reconnect to the simulator if the connection is lost. Note 1097 that if this is not used carefully, it can be a security issue, as 1098 the interface has the ability to send resets, NMIs, and power off 1099 the VM. It's best if QEMU makes a connection to an external 1100 simulator running on a secure port on localhost, so neither the 1101 simulator nor QEMU is exposed to any outside network. 1102 1103 See the "lanserv/README.vm" file in the OpenIPMI library for more 1104 details on the external interface. 1105 1106``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]`` 1107 Add a KCS IPMI interface on the ISA bus. This also adds a 1108 corresponding ACPI and SMBIOS entries, if appropriate. 1109 1110 ``bmc=id`` 1111 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern 1112 above. 1113 1114 ``ioport=val`` 1115 Define the I/O address of the interface. The default is 0xca0 1116 for KCS. 1117 1118 ``irq=val`` 1119 Define the interrupt to use. The default is 5. To disable 1120 interrupts, set this to 0. 1121 1122``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]`` 1123 Like the KCS interface, but defines a BT interface. The default port 1124 is 0xe4 and the default interrupt is 5. 1125 1126``-device pci-ipmi-kcs,bmc=id`` 1127 Add a KCS IPMI interface on the PCI bus. 1128 1129 ``bmc=id`` 1130 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 1131 1132``-device pci-ipmi-bt,bmc=id`` 1133 Like the KCS interface, but defines a BT interface on the PCI bus. 1134 1135``-device intel-iommu[,option=...]`` 1136 This is only supported by ``-machine q35``, which will enable Intel VT-d 1137 emulation within the guest. It supports below options: 1138 1139 ``intremap=on|off`` (default: auto) 1140 This enables interrupt remapping feature. It's required to enable 1141 complete x2apic. Currently it only supports kvm kernel-irqchip modes 1142 ``off`` or ``split``, while full kernel-irqchip is not yet supported. 1143 The default value is "auto", which will be decided by the mode of 1144 kernel-irqchip. 1145 1146 ``caching-mode=on|off`` (default: off) 1147 This enables caching mode for the VT-d emulated device. When 1148 caching-mode is enabled, each guest DMA buffer mapping will generate an 1149 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in 1150 a synchronous way. It is required for ``-device vfio-pci`` to work 1151 with the VT-d device, because host assigned devices requires to setup 1152 the DMA mapping on the host before guest DMA starts. 1153 1154 ``device-iotlb=on|off`` (default: off) 1155 This enables device-iotlb capability for the emulated VT-d device. So 1156 far virtio/vhost should be the only real user for this parameter, 1157 paired with ats=on configured for the device. 1158 1159 ``aw-bits=39|48`` (default: 39) 1160 This decides the address width of IOVA address space. The address 1161 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for 1162 4-level IOMMU page tables. 1163 1164 Please also refer to the wiki page for general scenarios of VT-d 1165 emulation in QEMU: https://wiki.qemu.org/Features/VT-d. 1166 1167ERST 1168 1169DEF("name", HAS_ARG, QEMU_OPTION_name, 1170 "-name string1[,process=string2][,debug-threads=on|off]\n" 1171 " set the name of the guest\n" 1172 " string1 sets the window title and string2 the process name\n" 1173 " When debug-threads is enabled, individual threads are given a separate name\n" 1174 " NOTE: The thread names are for debugging and not a stable API.\n", 1175 QEMU_ARCH_ALL) 1176SRST 1177``-name name`` 1178 Sets the name of the guest. This name will be displayed in the SDL 1179 window caption. The name will also be used for the VNC server. Also 1180 optionally set the top visible process name in Linux. Naming of 1181 individual threads can also be enabled on Linux to aid debugging. 1182ERST 1183 1184DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 1185 "-uuid %08x-%04x-%04x-%04x-%012x\n" 1186 " specify machine UUID\n", QEMU_ARCH_ALL) 1187SRST 1188``-uuid uuid`` 1189 Set system UUID. 1190ERST 1191 1192DEFHEADING() 1193 1194DEFHEADING(Block device options:) 1195 1196SRST 1197The QEMU block device handling options have a long history and 1198have gone through several iterations as the feature set and complexity 1199of the block layer have grown. Many online guides to QEMU often 1200reference older and deprecated options, which can lead to confusion. 1201 1202The most explicit way to describe disks is to use a combination of 1203``-device`` to specify the hardware device and ``-blockdev`` to 1204describe the backend. The device defines what the guest sees and the 1205backend describes how QEMU handles the data. It is the only guaranteed 1206stable interface for describing block devices and as such is 1207recommended for management tools and scripting. 1208 1209The ``-drive`` option combines the device and backend into a single 1210command line option which is a more human friendly. There is however no 1211interface stability guarantee although some older board models still 1212need updating to work with the modern blockdev forms. 1213 1214Older options like ``-hda`` are essentially macros which expand into 1215``-drive`` options for various drive interfaces. The original forms 1216bake in a lot of assumptions from the days when QEMU was emulating a 1217legacy PC, they are not recommended for modern configurations. 1218 1219ERST 1220 1221DEF("fda", HAS_ARG, QEMU_OPTION_fda, 1222 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 1223DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 1224SRST 1225``-fda file`` 1226 \ 1227``-fdb file`` 1228 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in 1229 the System Emulation Users Guide). 1230ERST 1231 1232DEF("hda", HAS_ARG, QEMU_OPTION_hda, 1233 "-hda/-hdb file use 'file' as hard disk 0/1 image\n", QEMU_ARCH_ALL) 1234DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 1235DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 1236 "-hdc/-hdd file use 'file' as hard disk 2/3 image\n", QEMU_ARCH_ALL) 1237DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 1238SRST 1239``-hda file`` 1240 \ 1241``-hdb file`` 1242 \ 1243``-hdc file`` 1244 \ 1245``-hdd file`` 1246 Use file as hard disk 0, 1, 2 or 3 image on the default bus of the 1247 emulated machine (this is for example the IDE bus on most x86 machines, 1248 but it can also be SCSI, virtio or something else on other target 1249 architectures). See also the :ref:`disk images` chapter in the System 1250 Emulation Users Guide. 1251ERST 1252 1253DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 1254 "-cdrom file use 'file' as CD-ROM image\n", 1255 QEMU_ARCH_ALL) 1256SRST 1257``-cdrom file`` 1258 Use file as CD-ROM image on the default bus of the emulated machine 1259 (which is IDE1 master on x86, so you cannot use ``-hdc`` and ``-cdrom`` 1260 at the same time there). On systems that support it, you can use the 1261 host CD-ROM by using ``/dev/cdrom`` as filename. 1262ERST 1263 1264DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 1265 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 1266 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 1267 " [,read-only=on|off][,auto-read-only=on|off]\n" 1268 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 1269 " [,driver specific parameters...]\n" 1270 " configure a block backend\n", QEMU_ARCH_ALL) 1271SRST 1272``-blockdev option[,option[,option[,...]]]`` 1273 Define a new block driver node. Some of the options apply to all 1274 block drivers, other options are only accepted for a specific block 1275 driver. See below for a list of generic options and options for the 1276 most common block drivers. 1277 1278 Options that expect a reference to another node (e.g. ``file``) can 1279 be given in two ways. Either you specify the node name of an already 1280 existing node (file=node-name), or you define a new node inline, 1281 adding options for the referenced node after a dot 1282 (file.filename=path,file.aio=native). 1283 1284 A block driver node created with ``-blockdev`` can be used for a 1285 guest device by specifying its node name for the ``drive`` property 1286 in a ``-device`` argument that defines a block device. 1287 1288 ``Valid options for any block driver node:`` 1289 ``driver`` 1290 Specifies the block driver to use for the given node. 1291 1292 ``node-name`` 1293 This defines the name of the block driver node by which it 1294 will be referenced later. The name must be unique, i.e. it 1295 must not match the name of a different block driver node, or 1296 (if you use ``-drive`` as well) the ID of a drive. 1297 1298 If no node name is specified, it is automatically generated. 1299 The generated node name is not intended to be predictable 1300 and changes between QEMU invocations. For the top level, an 1301 explicit node name must be specified. 1302 1303 ``read-only`` 1304 Open the node read-only. Guest write attempts will fail. 1305 1306 Note that some block drivers support only read-only access, 1307 either generally or in certain configurations. In this case, 1308 the default value ``read-only=off`` does not work and the 1309 option must be specified explicitly. 1310 1311 ``auto-read-only`` 1312 If ``auto-read-only=on`` is set, QEMU may fall back to 1313 read-only usage even when ``read-only=off`` is requested, or 1314 even switch between modes as needed, e.g. depending on 1315 whether the image file is writable or whether a writing user 1316 is attached to the node. 1317 1318 ``force-share`` 1319 Override the image locking system of QEMU by forcing the 1320 node to utilize weaker shared access for permissions where 1321 it would normally request exclusive access. When there is 1322 the potential for multiple instances to have the same file 1323 open (whether this invocation of QEMU is the first or the 1324 second instance), both instances must permit shared access 1325 for the second instance to succeed at opening the file. 1326 1327 Enabling ``force-share=on`` requires ``read-only=on``. 1328 1329 ``cache.direct`` 1330 The host page cache can be avoided with ``cache.direct=on``. 1331 This will attempt to do disk IO directly to the guest's 1332 memory. QEMU may still perform an internal copy of the data. 1333 1334 ``cache.no-flush`` 1335 In case you don't care about data integrity over host 1336 failures, you can use ``cache.no-flush=on``. This option 1337 tells QEMU that it never needs to write any data to the disk 1338 but can instead keep things in cache. If anything goes 1339 wrong, like your host losing power, the disk storage getting 1340 disconnected accidentally, etc. your image will most 1341 probably be rendered unusable. 1342 1343 ``discard=discard`` 1344 discard is one of "ignore" (or "off") or "unmap" (or "on") 1345 and controls whether ``discard`` (also known as ``trim`` or 1346 ``unmap``) requests are ignored or passed to the filesystem. 1347 Some machine types may not support discard requests. 1348 1349 ``detect-zeroes=detect-zeroes`` 1350 detect-zeroes is "off", "on" or "unmap" and enables the 1351 automatic conversion of plain zero writes by the OS to 1352 driver specific optimized zero write commands. You may even 1353 choose "unmap" if discard is set to "unmap" to allow a zero 1354 write to be converted to an ``unmap`` operation. 1355 1356 ``Driver-specific options for file`` 1357 This is the protocol-level block driver for accessing regular 1358 files. 1359 1360 ``filename`` 1361 The path to the image file in the local filesystem 1362 1363 ``aio`` 1364 Specifies the AIO backend (threads/native/io_uring, 1365 default: threads) 1366 1367 ``locking`` 1368 Specifies whether the image file is protected with Linux OFD 1369 / POSIX locks. The default is to use the Linux Open File 1370 Descriptor API if available, otherwise no lock is applied. 1371 (auto/on/off, default: auto) 1372 1373 Example: 1374 1375 :: 1376 1377 -blockdev driver=file,node-name=disk,filename=disk.img 1378 1379 ``Driver-specific options for raw`` 1380 This is the image format block driver for raw images. It is 1381 usually stacked on top of a protocol level block driver such as 1382 ``file``. 1383 1384 ``file`` 1385 Reference to or definition of the data source block driver 1386 node (e.g. a ``file`` driver node) 1387 1388 Example 1: 1389 1390 :: 1391 1392 -blockdev driver=file,node-name=disk_file,filename=disk.img 1393 -blockdev driver=raw,node-name=disk,file=disk_file 1394 1395 Example 2: 1396 1397 :: 1398 1399 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1400 1401 ``Driver-specific options for qcow2`` 1402 This is the image format block driver for qcow2 images. It is 1403 usually stacked on top of a protocol level block driver such as 1404 ``file``. 1405 1406 ``file`` 1407 Reference to or definition of the data source block driver 1408 node (e.g. a ``file`` driver node) 1409 1410 ``backing`` 1411 Reference to or definition of the backing file block device 1412 (default is taken from the image file). It is allowed to 1413 pass ``null`` here in order to disable the default backing 1414 file. 1415 1416 ``lazy-refcounts`` 1417 Whether to enable the lazy refcounts feature (on/off; 1418 default is taken from the image file) 1419 1420 ``cache-size`` 1421 The maximum total size of the L2 table and refcount block 1422 caches in bytes (default: the sum of l2-cache-size and 1423 refcount-cache-size) 1424 1425 ``l2-cache-size`` 1426 The maximum size of the L2 table cache in bytes (default: if 1427 cache-size is not specified - 32M on Linux platforms, and 8M 1428 on non-Linux platforms; otherwise, as large as possible 1429 within the cache-size, while permitting the requested or the 1430 minimal refcount cache size) 1431 1432 ``refcount-cache-size`` 1433 The maximum size of the refcount block cache in bytes 1434 (default: 4 times the cluster size; or if cache-size is 1435 specified, the part of it which is not used for the L2 1436 cache) 1437 1438 ``cache-clean-interval`` 1439 Clean unused entries in the L2 and refcount caches. The 1440 interval is in seconds. The default value is 600 on 1441 supporting platforms, and 0 on other platforms. Setting it 1442 to 0 disables this feature. 1443 1444 ``pass-discard-request`` 1445 Whether discard requests to the qcow2 device should be 1446 forwarded to the data source (on/off; default: on if 1447 discard=unmap is specified, off otherwise) 1448 1449 ``pass-discard-snapshot`` 1450 Whether discard requests for the data source should be 1451 issued when a snapshot operation (e.g. deleting a snapshot) 1452 frees clusters in the qcow2 file (on/off; default: on) 1453 1454 ``pass-discard-other`` 1455 Whether discard requests for the data source should be 1456 issued on other occasions where a cluster gets freed 1457 (on/off; default: off) 1458 1459 ``discard-no-unref`` 1460 When enabled, discards from the guest will not cause cluster 1461 allocations to be relinquished. This prevents qcow2 fragmentation 1462 that would be caused by such discards. Besides potential 1463 performance degradation, such fragmentation can lead to increased 1464 allocation of clusters past the end of the image file, 1465 resulting in image files whose file length can grow much larger 1466 than their guest disk size would suggest. 1467 If image file length is of concern (e.g. when storing qcow2 1468 images directly on block devices), you should consider enabling 1469 this option. 1470 1471 ``overlap-check`` 1472 Which overlap checks to perform for writes to the image 1473 (none/constant/cached/all; default: cached). For details or 1474 finer granularity control refer to the QAPI documentation of 1475 ``blockdev-add``. 1476 1477 Example 1: 1478 1479 :: 1480 1481 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1482 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1483 1484 Example 2: 1485 1486 :: 1487 1488 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1489 1490 ``Driver-specific options for other drivers`` 1491 Please refer to the QAPI documentation of the ``blockdev-add`` 1492 QMP command. 1493ERST 1494 1495DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1496 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1497 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1498 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1499 " [,werror=ignore|stop|report|enospc][,id=name]\n" 1500 " [,aio=threads|native|io_uring]\n" 1501 " [,readonly=on|off][,copy-on-read=on|off]\n" 1502 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1503 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1504 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1505 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1506 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1507 " [[,iops_size=is]]\n" 1508 " [[,group=g]]\n" 1509 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1510SRST 1511``-drive option[,option[,option[,...]]]`` 1512 Define a new drive. This includes creating a block driver node (the 1513 backend) as well as a guest device, and is mostly a shortcut for 1514 defining the corresponding ``-blockdev`` and ``-device`` options. 1515 1516 ``-drive`` accepts all options that are accepted by ``-blockdev``. 1517 In addition, it knows the following options: 1518 1519 ``file=file`` 1520 This option defines which disk image (see the :ref:`disk images` 1521 chapter in the System Emulation Users Guide) to use with this drive. 1522 If the filename contains comma, you must double it (for instance, 1523 "file=my,,file" to use file "my,file"). 1524 1525 Special files such as iSCSI devices can be specified using 1526 protocol specific URLs. See the section for "Device URL Syntax" 1527 for more information. 1528 1529 ``if=interface`` 1530 This option defines on which type on interface the drive is 1531 connected. Available types are: ide, scsi, sd, mtd, floppy, 1532 pflash, virtio, none. 1533 1534 ``bus=bus,unit=unit`` 1535 These options define where is connected the drive by defining 1536 the bus number and the unit id. 1537 1538 ``index=index`` 1539 This option defines where the drive is connected by using an 1540 index in the list of available connectors of a given interface 1541 type. 1542 1543 ``media=media`` 1544 This option defines the type of the media: disk or cdrom. 1545 1546 ``snapshot=snapshot`` 1547 snapshot is "on" or "off" and controls snapshot mode for the 1548 given drive (see ``-snapshot``). 1549 1550 ``cache=cache`` 1551 cache is "none", "writeback", "unsafe", "directsync" or 1552 "writethrough" and controls how the host cache is used to access 1553 block data. This is a shortcut that sets the ``cache.direct`` 1554 and ``cache.no-flush`` options (as in ``-blockdev``), and 1555 additionally ``cache.writeback``, which provides a default for 1556 the ``write-cache`` option of block guest devices (as in 1557 ``-device``). The modes correspond to the following settings: 1558 1559 ============= =============== ============ ============== 1560 \ cache.writeback cache.direct cache.no-flush 1561 ============= =============== ============ ============== 1562 writeback on off off 1563 none on on off 1564 writethrough off off off 1565 directsync off on off 1566 unsafe on off on 1567 ============= =============== ============ ============== 1568 1569 The default mode is ``cache=writeback``. 1570 1571 ``aio=aio`` 1572 aio is "threads", "native", or "io_uring" and selects between pthread 1573 based disk I/O, native Linux AIO, or Linux io_uring API. 1574 1575 ``format=format`` 1576 Specify which disk format will be used rather than detecting the 1577 format. Can be used to specify format=raw to avoid interpreting 1578 an untrusted format header. 1579 1580 ``werror=action,rerror=action`` 1581 Specify which action to take on write and read errors. Valid 1582 actions are: "ignore" (ignore the error and try to continue), 1583 "stop" (pause QEMU), "report" (report the error to the guest), 1584 "enospc" (pause QEMU only if the host disk is full; report the 1585 error to the guest otherwise). The default setting is 1586 ``werror=enospc`` and ``rerror=report``. 1587 1588 ``copy-on-read=copy-on-read`` 1589 copy-on-read is "on" or "off" and enables whether to copy read 1590 backing file sectors into the image file. 1591 1592 ``bps=b,bps_rd=r,bps_wr=w`` 1593 Specify bandwidth throttling limits in bytes per second, either 1594 for all request types or for reads or writes only. Small values 1595 can lead to timeouts or hangs inside the guest. A safe minimum 1596 for disks is 2 MB/s. 1597 1598 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm`` 1599 Specify bursts in bytes per second, either for all request types 1600 or for reads or writes only. Bursts allow the guest I/O to spike 1601 above the limit temporarily. 1602 1603 ``iops=i,iops_rd=r,iops_wr=w`` 1604 Specify request rate limits in requests per second, either for 1605 all request types or for reads or writes only. 1606 1607 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm`` 1608 Specify bursts in requests per second, either for all request 1609 types or for reads or writes only. Bursts allow the guest I/O to 1610 spike above the limit temporarily. 1611 1612 ``iops_size=is`` 1613 Let every is bytes of a request count as a new request for iops 1614 throttling purposes. Use this option to prevent guests from 1615 circumventing iops limits by sending fewer but larger requests. 1616 1617 ``group=g`` 1618 Join a throttling quota group with given name g. All drives that 1619 are members of the same group are accounted for together. Use 1620 this option to prevent guests from circumventing throttling 1621 limits by using many small disks instead of a single larger 1622 disk. 1623 1624 By default, the ``cache.writeback=on`` mode is used. It will report 1625 data writes as completed as soon as the data is present in the host 1626 page cache. This is safe as long as your guest OS makes sure to 1627 correctly flush disk caches where needed. If your guest OS does not 1628 handle volatile disk write caches correctly and your host crashes or 1629 loses power, then the guest may experience data corruption. 1630 1631 For such guests, you should consider using ``cache.writeback=off``. 1632 This means that the host page cache will be used to read and write 1633 data, but write notification will be sent to the guest only after 1634 QEMU has made sure to flush each write to the disk. Be aware that 1635 this has a major impact on performance. 1636 1637 When using the ``-snapshot`` option, unsafe caching is always used. 1638 1639 Copy-on-read avoids accessing the same backing file sectors 1640 repeatedly and is useful when the backing file is over a slow 1641 network. By default copy-on-read is off. 1642 1643 Instead of ``-cdrom`` you can use: 1644 1645 .. parsed-literal:: 1646 1647 |qemu_system| -drive file=file,index=2,media=cdrom 1648 1649 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use: 1650 1651 .. parsed-literal:: 1652 1653 |qemu_system| -drive file=file,index=0,media=disk 1654 |qemu_system| -drive file=file,index=1,media=disk 1655 |qemu_system| -drive file=file,index=2,media=disk 1656 |qemu_system| -drive file=file,index=3,media=disk 1657 1658 You can open an image using pre-opened file descriptors from an fd 1659 set: 1660 1661 .. parsed-literal:: 1662 1663 |qemu_system| \\ 1664 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 1665 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 1666 -drive file=/dev/fdset/2,index=0,media=disk 1667 1668 You can connect a CDROM to the slave of ide0: 1669 1670 .. parsed-literal:: 1671 1672 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom 1673 1674 If you don't specify the "file=" argument, you define an empty 1675 drive: 1676 1677 .. parsed-literal:: 1678 1679 |qemu_system_x86| -drive if=ide,index=1,media=cdrom 1680 1681 Instead of ``-fda``, ``-fdb``, you can use: 1682 1683 .. parsed-literal:: 1684 1685 |qemu_system_x86| -drive file=file,index=0,if=floppy 1686 |qemu_system_x86| -drive file=file,index=1,if=floppy 1687 1688 By default, interface is "ide" and index is automatically 1689 incremented: 1690 1691 .. parsed-literal:: 1692 1693 |qemu_system_x86| -drive file=a -drive file=b 1694 1695 is interpreted like: 1696 1697 .. parsed-literal:: 1698 1699 |qemu_system_x86| -hda a -hdb b 1700ERST 1701 1702DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1703 "-mtdblock file use 'file' as on-board Flash memory image\n", 1704 QEMU_ARCH_ALL) 1705SRST 1706``-mtdblock file`` 1707 Use file as on-board Flash memory image. 1708ERST 1709 1710DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1711 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1712SRST 1713``-sd file`` 1714 Use file as SecureDigital card image. 1715ERST 1716 1717DEF("snapshot", 0, QEMU_OPTION_snapshot, 1718 "-snapshot write to temporary files instead of disk image files\n", 1719 QEMU_ARCH_ALL) 1720SRST 1721``-snapshot`` 1722 Write to temporary files instead of disk image files. In this case, 1723 the raw disk image you use is not written back. You can however 1724 force the write back by pressing C-a s (see the :ref:`disk images` 1725 chapter in the System Emulation Users Guide). 1726 1727 .. warning:: 1728 snapshot is incompatible with ``-blockdev`` (instead use qemu-img 1729 to manually create snapshot images to attach to your blockdev). 1730 If you have mixed ``-blockdev`` and ``-drive`` declarations you 1731 can use the 'snapshot' property on your drive declarations 1732 instead of this global option. 1733 1734ERST 1735 1736DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1737 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1738 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n" 1739 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1740 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1741 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1742 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1743 " [[,throttling.iops-size=is]]\n" 1744 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly=on]\n" 1745 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly=on]\n" 1746 "-fsdev synth,id=id\n", 1747 QEMU_ARCH_ALL) 1748 1749SRST 1750``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly=on][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]`` 1751 \ 1752``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly=on]`` 1753 \ 1754``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly=on]`` 1755 \ 1756``-fsdev synth,id=id[,readonly=on]`` 1757 Define a new file system device. Valid options are: 1758 1759 ``local`` 1760 Accesses to the filesystem are done by QEMU. 1761 1762 ``proxy`` 1763 Accesses to the filesystem are done by virtfs-proxy-helper(1). This 1764 option is deprecated (since QEMU 8.1) and will be removed in a future 1765 version of QEMU. Use ``local`` instead. 1766 1767 ``synth`` 1768 Synthetic filesystem, only used by QTests. 1769 1770 ``id=id`` 1771 Specifies identifier for this device. 1772 1773 ``path=path`` 1774 Specifies the export path for the file system device. Files 1775 under this path will be available to the 9p client on the guest. 1776 1777 ``security_model=security_model`` 1778 Specifies the security model to be used for this export path. 1779 Supported security models are "passthrough", "mapped-xattr", 1780 "mapped-file" and "none". In "passthrough" security model, files 1781 are stored using the same credentials as they are created on the 1782 guest. This requires QEMU to run as root. In "mapped-xattr" 1783 security model, some of the file attributes like uid, gid, mode 1784 bits and link target are stored as file attributes. For 1785 "mapped-file" these attributes are stored in the hidden 1786 .virtfs\_metadata directory. Directories exported by this 1787 security model cannot interact with other unix tools. "none" 1788 security model is same as passthrough except the sever won't 1789 report failures if it fails to set file attributes like 1790 ownership. Security model is mandatory only for local fsdriver. 1791 Other fsdrivers (like proxy) don't take security model as a 1792 parameter. 1793 1794 ``writeout=writeout`` 1795 This is an optional argument. The only supported value is 1796 "immediate". This means that host page cache will be used to 1797 read and write data but write notification will be sent to the 1798 guest only when the data has been reported as written by the 1799 storage subsystem. 1800 1801 ``readonly=on`` 1802 Enables exporting 9p share as a readonly mount for guests. By 1803 default read-write access is given. 1804 1805 ``socket=socket`` 1806 Enables proxy filesystem driver to use passed socket file for 1807 communicating with virtfs-proxy-helper(1). 1808 1809 ``sock_fd=sock_fd`` 1810 Enables proxy filesystem driver to use passed socket descriptor 1811 for communicating with virtfs-proxy-helper(1). Usually a helper 1812 like libvirt will create socketpair and pass one of the fds as 1813 sock\_fd. 1814 1815 ``fmode=fmode`` 1816 Specifies the default mode for newly created files on the host. 1817 Works only with security models "mapped-xattr" and 1818 "mapped-file". 1819 1820 ``dmode=dmode`` 1821 Specifies the default mode for newly created directories on the 1822 host. Works only with security models "mapped-xattr" and 1823 "mapped-file". 1824 1825 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w`` 1826 Specify bandwidth throttling limits in bytes per second, either 1827 for all request types or for reads or writes only. 1828 1829 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm`` 1830 Specify bursts in bytes per second, either for all request types 1831 or for reads or writes only. Bursts allow the guest I/O to spike 1832 above the limit temporarily. 1833 1834 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w`` 1835 Specify request rate limits in requests per second, either for 1836 all request types or for reads or writes only. 1837 1838 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm`` 1839 Specify bursts in requests per second, either for all request 1840 types or for reads or writes only. Bursts allow the guest I/O to 1841 spike above the limit temporarily. 1842 1843 ``throttling.iops-size=is`` 1844 Let every is bytes of a request count as a new request for iops 1845 throttling purposes. 1846 1847 -fsdev option is used along with -device driver "virtio-9p-...". 1848 1849``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag`` 1850 Options for virtio-9p-... driver are: 1851 1852 ``type`` 1853 Specifies the variant to be used. Supported values are "pci", 1854 "ccw" or "device", depending on the machine type. 1855 1856 ``fsdev=id`` 1857 Specifies the id value specified along with -fsdev option. 1858 1859 ``mount_tag=mount_tag`` 1860 Specifies the tag name to be used by the guest to mount this 1861 export point. 1862ERST 1863 1864DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1865 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1866 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1867 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly=on]\n" 1868 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly=on]\n" 1869 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n", 1870 QEMU_ARCH_ALL) 1871 1872SRST 1873``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly=on] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]`` 1874 \ 1875``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1876 \ 1877``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1878 \ 1879``-virtfs synth,mount_tag=mount_tag`` 1880 Define a new virtual filesystem device and expose it to the guest using 1881 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain 1882 directory on host is made directly accessible by guest as a pass-through 1883 file system by using the 9P network protocol for communication between 1884 host and guests, if desired even accessible, shared by several guests 1885 simultaneously. 1886 1887 Note that ``-virtfs`` is actually just a convenience shortcut for its 1888 generalized form ``-fsdev -device virtio-9p-pci``. 1889 1890 The general form of pass-through file system options are: 1891 1892 ``local`` 1893 Accesses to the filesystem are done by QEMU. 1894 1895 ``proxy`` 1896 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1897 This option is deprecated (since QEMU 8.1) and will be removed in a 1898 future version of QEMU. Use ``local`` instead. 1899 1900 ``synth`` 1901 Synthetic filesystem, only used by QTests. 1902 1903 ``id=id`` 1904 Specifies identifier for the filesystem device 1905 1906 ``path=path`` 1907 Specifies the export path for the file system device. Files 1908 under this path will be available to the 9p client on the guest. 1909 1910 ``security_model=security_model`` 1911 Specifies the security model to be used for this export path. 1912 Supported security models are "passthrough", "mapped-xattr", 1913 "mapped-file" and "none". In "passthrough" security model, files 1914 are stored using the same credentials as they are created on the 1915 guest. This requires QEMU to run as root. In "mapped-xattr" 1916 security model, some of the file attributes like uid, gid, mode 1917 bits and link target are stored as file attributes. For 1918 "mapped-file" these attributes are stored in the hidden 1919 .virtfs\_metadata directory. Directories exported by this 1920 security model cannot interact with other unix tools. "none" 1921 security model is same as passthrough except the sever won't 1922 report failures if it fails to set file attributes like 1923 ownership. Security model is mandatory only for local fsdriver. 1924 Other fsdrivers (like proxy) don't take security model as a 1925 parameter. 1926 1927 ``writeout=writeout`` 1928 This is an optional argument. The only supported value is 1929 "immediate". This means that host page cache will be used to 1930 read and write data but write notification will be sent to the 1931 guest only when the data has been reported as written by the 1932 storage subsystem. 1933 1934 ``readonly=on`` 1935 Enables exporting 9p share as a readonly mount for guests. By 1936 default read-write access is given. 1937 1938 ``socket=socket`` 1939 Enables proxy filesystem driver to use passed socket file for 1940 communicating with virtfs-proxy-helper(1). Usually a helper like 1941 libvirt will create socketpair and pass one of the fds as 1942 sock\_fd. 1943 1944 ``sock_fd`` 1945 Enables proxy filesystem driver to use passed 'sock\_fd' as the 1946 socket descriptor for interfacing with virtfs-proxy-helper(1). 1947 1948 ``fmode=fmode`` 1949 Specifies the default mode for newly created files on the host. 1950 Works only with security models "mapped-xattr" and 1951 "mapped-file". 1952 1953 ``dmode=dmode`` 1954 Specifies the default mode for newly created directories on the 1955 host. Works only with security models "mapped-xattr" and 1956 "mapped-file". 1957 1958 ``mount_tag=mount_tag`` 1959 Specifies the tag name to be used by the guest to mount this 1960 export point. 1961 1962 ``multidevs=multidevs`` 1963 Specifies how to deal with multiple devices being shared with a 1964 9p export. Supported behaviours are either "remap", "forbid" or 1965 "warn". The latter is the default behaviour on which virtfs 9p 1966 expects only one device to be shared with the same export, and 1967 if more than one device is shared and accessed via the same 9p 1968 export then only a warning message is logged (once) by qemu on 1969 host side. In order to avoid file ID collisions on guest you 1970 should either create a separate virtfs export for each device to 1971 be shared with guests (recommended way) or you might use "remap" 1972 instead which allows you to share multiple devices with only one 1973 export instead, which is achieved by remapping the original 1974 inode numbers from host to guest in a way that would prevent 1975 such collisions. Remapping inodes in such use cases is required 1976 because the original device IDs from host are never passed and 1977 exposed on guest. Instead all files of an export shared with 1978 virtfs always share the same device id on guest. So two files 1979 with identical inode numbers but from actually different devices 1980 on host would otherwise cause a file ID collision and hence 1981 potential misbehaviours on guest. "forbid" on the other hand 1982 assumes like "warn" that only one device is shared by the same 1983 export, however it will not only log a warning message but also 1984 deny access to additional devices on guest. Note though that 1985 "forbid" does currently not block all possible file access 1986 operations (e.g. readdir() would still return entries from other 1987 devices). 1988ERST 1989 1990DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1991 "-iscsi [user=user][,password=password][,password-secret=secret-id]\n" 1992 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE]\n" 1993 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1994 " [,timeout=timeout]\n" 1995 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1996 1997SRST 1998``-iscsi`` 1999 Configure iSCSI session parameters. 2000ERST 2001 2002DEFHEADING() 2003 2004DEFHEADING(USB convenience options:) 2005 2006DEF("usb", 0, QEMU_OPTION_usb, 2007 "-usb enable on-board USB host controller (if not enabled by default)\n", 2008 QEMU_ARCH_ALL) 2009SRST 2010``-usb`` 2011 Enable USB emulation on machine types with an on-board USB host 2012 controller (if not enabled by default). Note that on-board USB host 2013 controllers may not support USB 3.0. In this case 2014 ``-device qemu-xhci`` can be used instead on machines with PCI. 2015ERST 2016 2017DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 2018 "-usbdevice name add the host or guest USB device 'name'\n", 2019 QEMU_ARCH_ALL) 2020SRST 2021``-usbdevice devname`` 2022 Add the USB device devname, and enable an on-board USB controller 2023 if possible and necessary (just like it can be done via 2024 ``-machine usb=on``). Note that this option is mainly intended for 2025 the user's convenience only. More fine-grained control can be 2026 achieved by selecting a USB host controller (if necessary) and the 2027 desired USB device via the ``-device`` option instead. For example, 2028 instead of using ``-usbdevice mouse`` it is possible to use 2029 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse 2030 to a USB 3.0 controller instead (at least on machines that support 2031 PCI and do not have an USB controller enabled by default yet). 2032 For more details, see the chapter about 2033 :ref:`Connecting USB devices` in the System Emulation Users Guide. 2034 Possible devices for devname are: 2035 2036 ``braille`` 2037 Braille device. This will use BrlAPI to display the braille 2038 output on a real or fake device (i.e. it also creates a 2039 corresponding ``braille`` chardev automatically beside the 2040 ``usb-braille`` USB device). 2041 2042 ``keyboard`` 2043 Standard USB keyboard. Will override the PS/2 keyboard (if present). 2044 2045 ``mouse`` 2046 Virtual Mouse. This will override the PS/2 mouse emulation when 2047 activated. 2048 2049 ``tablet`` 2050 Pointer device that uses absolute coordinates (like a 2051 touchscreen). This means QEMU is able to report the mouse 2052 position without having to grab the mouse. Also overrides the 2053 PS/2 mouse emulation when activated. 2054 2055 ``wacom-tablet`` 2056 Wacom PenPartner USB tablet. 2057 2058 2059ERST 2060 2061DEFHEADING() 2062 2063DEFHEADING(Display options:) 2064 2065DEF("display", HAS_ARG, QEMU_OPTION_display, 2066#if defined(CONFIG_SPICE) 2067 "-display spice-app[,gl=on|off]\n" 2068#endif 2069#if defined(CONFIG_SDL) 2070 "-display sdl[,gl=on|core|es|off][,grab-mod=<mod>][,show-cursor=on|off]\n" 2071 " [,window-close=on|off]\n" 2072#endif 2073#if defined(CONFIG_GTK) 2074 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n" 2075 " [,show-tabs=on|off][,show-cursor=on|off][,window-close=on|off]\n" 2076 " [,show-menubar=on|off]\n" 2077#endif 2078#if defined(CONFIG_VNC) 2079 "-display vnc=<display>[,<optargs>]\n" 2080#endif 2081#if defined(CONFIG_CURSES) 2082 "-display curses[,charset=<encoding>]\n" 2083#endif 2084#if defined(CONFIG_COCOA) 2085 "-display cocoa[,full-grab=on|off][,swap-opt-cmd=on|off]\n" 2086#endif 2087#if defined(CONFIG_OPENGL) 2088 "-display egl-headless[,rendernode=<file>]\n" 2089#endif 2090#if defined(CONFIG_DBUS_DISPLAY) 2091 "-display dbus[,addr=<dbusaddr>]\n" 2092 " [,gl=on|core|es|off][,rendernode=<file>]\n" 2093#endif 2094#if defined(CONFIG_COCOA) 2095 "-display cocoa[,show-cursor=on|off][,left-command-key=on|off]\n" 2096#endif 2097 "-display none\n" 2098 " select display backend type\n" 2099 " The default display is equivalent to\n " 2100#if defined(CONFIG_GTK) 2101 "\"-display gtk\"\n" 2102#elif defined(CONFIG_SDL) 2103 "\"-display sdl\"\n" 2104#elif defined(CONFIG_COCOA) 2105 "\"-display cocoa\"\n" 2106#elif defined(CONFIG_VNC) 2107 "\"-vnc localhost:0,to=99,id=default\"\n" 2108#else 2109 "\"-display none\"\n" 2110#endif 2111 , QEMU_ARCH_ALL) 2112SRST 2113``-display type`` 2114 Select type of display to use. Use ``-display help`` to list the available 2115 display types. Valid values for type are 2116 2117 ``spice-app[,gl=on|off]`` 2118 Start QEMU as a Spice server and launch the default Spice client 2119 application. The Spice server will redirect the serial consoles 2120 and QEMU monitors. (Since 4.0) 2121 2122 ``dbus`` 2123 Export the display over D-Bus interfaces. (Since 7.0) 2124 2125 The connection is registered with the "org.qemu" name (and queued when 2126 already owned). 2127 2128 ``addr=<dbusaddr>`` : D-Bus bus address to connect to. 2129 2130 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``. 2131 2132 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface 2133 will share framebuffers with DMABUF file descriptors). 2134 2135 ``sdl`` 2136 Display video output via SDL (usually in a separate graphics 2137 window; see the SDL documentation for other possibilities). 2138 Valid parameters are: 2139 2140 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling 2141 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be 2142 either ``lshift-lctrl-lalt`` or ``rctrl``. 2143 2144 ``gl=on|off|core|es`` : Use OpenGL for displaying 2145 2146 ``show-cursor=on|off`` : Force showing the mouse cursor 2147 2148 ``window-close=on|off`` : Allow to quit qemu with window close button 2149 2150 ``gtk`` 2151 Display video output in a GTK window. This interface provides 2152 drop-down menus and other UI elements to configure and control 2153 the VM during runtime. Valid parameters are: 2154 2155 ``full-screen=on|off`` : Start in fullscreen mode 2156 2157 ``gl=on|off`` : Use OpenGL for displaying 2158 2159 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover 2160 2161 ``show-tabs=on|off`` : Display the tab bar for switching between the 2162 various graphical interfaces (e.g. VGA and 2163 virtual console character devices) by default. 2164 2165 ``show-cursor=on|off`` : Force showing the mouse cursor 2166 2167 ``window-close=on|off`` : Allow to quit qemu with window close button 2168 2169 ``show-menubar=on|off`` : Display the main window menubar, defaults to "on" 2170 2171 ``zoom-to-fit=on|off`` : Expand video output to the window size, 2172 defaults to "off" 2173 2174 ``curses[,charset=<encoding>]`` 2175 Display video output via curses. For graphics device models 2176 which support a text mode, QEMU can display this output using a 2177 curses/ncurses interface. Nothing is displayed when the graphics 2178 device is in graphical mode or if the graphics device does not 2179 support a text mode. Generally only the VGA device models 2180 support text mode. The font charset used by the guest can be 2181 specified with the ``charset`` option, for example 2182 ``charset=CP850`` for IBM CP850 encoding. The default is 2183 ``CP437``. 2184 2185 ``cocoa`` 2186 Display video output in a Cocoa window. Mac only. This interface 2187 provides drop-down menus and other UI elements to configure and 2188 control the VM during runtime. Valid parameters are: 2189 2190 ``show-cursor=on|off`` : Force showing the mouse cursor 2191 2192 ``left-command-key=on|off`` : Disable forwarding left command key to host 2193 2194 ``egl-headless[,rendernode=<file>]`` 2195 Offload all OpenGL operations to a local DRI device. For any 2196 graphical display, this display needs to be paired with either 2197 VNC or SPICE displays. 2198 2199 ``vnc=<display>`` 2200 Start a VNC server on display <display> 2201 2202 ``none`` 2203 Do not display video output. The guest will still see an 2204 emulated graphics card, but its output will not be displayed to 2205 the QEMU user. This option differs from the -nographic option in 2206 that it only affects what is done with video output; -nographic 2207 also changes the destination of the serial and parallel port 2208 data. 2209ERST 2210 2211DEF("nographic", 0, QEMU_OPTION_nographic, 2212 "-nographic disable graphical output and redirect serial I/Os to console\n", 2213 QEMU_ARCH_ALL) 2214SRST 2215``-nographic`` 2216 Normally, if QEMU is compiled with graphical window support, it 2217 displays output such as guest graphics, guest console, and the QEMU 2218 monitor in a window. With this option, you can totally disable 2219 graphical output so that QEMU is a simple command line application. 2220 The emulated serial port is redirected on the console and muxed with 2221 the monitor (unless redirected elsewhere explicitly). Therefore, you 2222 can still use QEMU to debug a Linux kernel with a serial console. 2223 Use C-a h for help on switching between the console and monitor. 2224ERST 2225 2226#ifdef CONFIG_SPICE 2227DEF("spice", HAS_ARG, QEMU_OPTION_spice, 2228 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 2229 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 2230 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 2231 " [,x509-dh-key-file=<file>][,addr=addr]\n" 2232 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n" 2233 " [,tls-ciphers=<list>]\n" 2234 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 2235 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 2236 " [,sasl=on|off][,disable-ticketing=on|off]\n" 2237 " [,password-secret=<secret-id>]\n" 2238 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 2239 " [,jpeg-wan-compression=[auto|never|always]]\n" 2240 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 2241 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n" 2242 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n" 2243 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 2244 " [,gl=[on|off]][,rendernode=<file>]\n" 2245 " enable spice\n" 2246 " at least one of {port, tls-port} is mandatory\n", 2247 QEMU_ARCH_ALL) 2248#endif 2249SRST 2250``-spice option[,option[,...]]`` 2251 Enable the spice remote desktop protocol. Valid options are 2252 2253 ``port=<nr>`` 2254 Set the TCP port spice is listening on for plaintext channels. 2255 2256 ``addr=<addr>`` 2257 Set the IP address spice is listening on. Default is any 2258 address. 2259 2260 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off`` 2261 Force using the specified IP version. 2262 2263 ``password-secret=<secret-id>`` 2264 Set the ID of the ``secret`` object containing the password 2265 you need to authenticate. 2266 2267 ``sasl=on|off`` 2268 Require that the client use SASL to authenticate with the spice. 2269 The exact choice of authentication method used is controlled 2270 from the system / user's SASL configuration file for the 'qemu' 2271 service. This is typically found in /etc/sasl2/qemu.conf. If 2272 running QEMU as an unprivileged user, an environment variable 2273 SASL\_CONF\_PATH can be used to make it search alternate 2274 locations for the service config. While some SASL auth methods 2275 can also provide data encryption (eg GSSAPI), it is recommended 2276 that SASL always be combined with the 'tls' and 'x509' settings 2277 to enable use of SSL and server certificates. This ensures a 2278 data encryption preventing compromise of authentication 2279 credentials. 2280 2281 ``disable-ticketing=on|off`` 2282 Allow client connects without authentication. 2283 2284 ``disable-copy-paste=on|off`` 2285 Disable copy paste between the client and the guest. 2286 2287 ``disable-agent-file-xfer=on|off`` 2288 Disable spice-vdagent based file-xfer between the client and the 2289 guest. 2290 2291 ``tls-port=<nr>`` 2292 Set the TCP port spice is listening on for encrypted channels. 2293 2294 ``x509-dir=<dir>`` 2295 Set the x509 file directory. Expects same filenames as -vnc 2296 $display,x509=$dir 2297 2298 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>`` 2299 The x509 file names can also be configured individually. 2300 2301 ``tls-ciphers=<list>`` 2302 Specify which ciphers to use. 2303 2304 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]`` 2305 Force specific channel to be used with or without TLS 2306 encryption. The options can be specified multiple times to 2307 configure multiple channels. The special name "default" can be 2308 used to set the default mode. For channels which are not 2309 explicitly forced into one mode the spice client is allowed to 2310 pick tls/plaintext as he pleases. 2311 2312 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]`` 2313 Configure image compression (lossless). Default is auto\_glz. 2314 2315 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]`` 2316 Configure wan image compression (lossy for slow links). Default 2317 is auto. 2318 2319 ``streaming-video=[off|all|filter]`` 2320 Configure video stream detection. Default is off. 2321 2322 ``agent-mouse=[on|off]`` 2323 Enable/disable passing mouse events via vdagent. Default is on. 2324 2325 ``playback-compression=[on|off]`` 2326 Enable/disable audio stream compression (using celt 0.5.1). 2327 Default is on. 2328 2329 ``seamless-migration=[on|off]`` 2330 Enable/disable spice seamless migration. Default is off. 2331 2332 ``gl=[on|off]`` 2333 Enable/disable OpenGL context. Default is off. 2334 2335 ``rendernode=<file>`` 2336 DRM render node for OpenGL rendering. If not specified, it will 2337 pick the first available. (Since 2.9) 2338ERST 2339 2340DEF("portrait", 0, QEMU_OPTION_portrait, 2341 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 2342 QEMU_ARCH_ALL) 2343SRST 2344``-portrait`` 2345 Rotate graphical output 90 deg left (only PXA LCD). 2346ERST 2347 2348DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 2349 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 2350 QEMU_ARCH_ALL) 2351SRST 2352``-rotate deg`` 2353 Rotate graphical output some deg left (only PXA LCD). 2354ERST 2355 2356DEF("vga", HAS_ARG, QEMU_OPTION_vga, 2357 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 2358 " select video card type\n", QEMU_ARCH_ALL) 2359SRST 2360``-vga type`` 2361 Select type of VGA card to emulate. Valid values for type are 2362 2363 ``cirrus`` 2364 Cirrus Logic GD5446 Video card. All Windows versions starting 2365 from Windows 95 should recognize and use this graphic card. For 2366 optimal performances, use 16 bit color depth in the guest and 2367 the host OS. (This card was the default before QEMU 2.2) 2368 2369 ``std`` 2370 Standard VGA card with Bochs VBE extensions. If your guest OS 2371 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if 2372 you want to use high resolution modes (>= 1280x1024x16) then you 2373 should use this option. (This card is the default since QEMU 2374 2.2) 2375 2376 ``vmware`` 2377 VMWare SVGA-II compatible adapter. Use it if you have 2378 sufficiently recent XFree86/XOrg server or Windows guest with a 2379 driver for this card. 2380 2381 ``qxl`` 2382 QXL paravirtual graphic card. It is VGA compatible (including 2383 VESA 2.0 VBE support). Works best with qxl guest drivers 2384 installed though. Recommended choice when using the spice 2385 protocol. 2386 2387 ``tcx`` 2388 (sun4m only) Sun TCX framebuffer. This is the default 2389 framebuffer for sun4m machines and offers both 8-bit and 24-bit 2390 colour depths at a fixed resolution of 1024x768. 2391 2392 ``cg3`` 2393 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit 2394 framebuffer for sun4m machines available in both 1024x768 2395 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people 2396 wishing to run older Solaris versions. 2397 2398 ``virtio`` 2399 Virtio VGA card. 2400 2401 ``none`` 2402 Disable VGA card. 2403ERST 2404 2405DEF("full-screen", 0, QEMU_OPTION_full_screen, 2406 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 2407SRST 2408``-full-screen`` 2409 Start in full screen. 2410ERST 2411 2412DEF("g", HAS_ARG, QEMU_OPTION_g , 2413 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 2414 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 2415SRST 2416``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]`` 2417 Set the initial graphical resolution and depth (PPC, SPARC only). 2418 2419 For PPC the default is 800x600x32. 2420 2421 For SPARC with the TCX graphics device, the default is 1024x768x8 2422 with the option of 1024x768x24. For cgthree, the default is 2423 1024x768x8 with the option of 1152x900x8 for people who wish to use 2424 OBP. 2425ERST 2426 2427DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 2428 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 2429SRST 2430``-vnc display[,option[,option[,...]]]`` 2431 Normally, if QEMU is compiled with graphical window support, it 2432 displays output such as guest graphics, guest console, and the QEMU 2433 monitor in a window. With this option, you can have QEMU listen on 2434 VNC display display and redirect the VGA display over the VNC 2435 session. It is very useful to enable the usb tablet device when 2436 using this option (option ``-device usb-tablet``). When using the 2437 VNC display, you must use the ``-k`` parameter to set the keyboard 2438 layout if you are not using en-us. Valid syntax for the display is 2439 2440 ``to=L`` 2441 With this option, QEMU will try next available VNC displays, 2442 until the number L, if the origianlly defined "-vnc display" is 2443 not available, e.g. port 5900+display is already used by another 2444 application. By default, to=0. 2445 2446 ``host:d`` 2447 TCP connections will only be allowed from host on display d. By 2448 convention the TCP port is 5900+d. Optionally, host can be 2449 omitted in which case the server will accept connections from 2450 any host. 2451 2452 ``unix:path`` 2453 Connections will be allowed over UNIX domain sockets where path 2454 is the location of a unix socket to listen for connections on. 2455 2456 ``none`` 2457 VNC is initialized but not started. The monitor ``change`` 2458 command can be used to later start the VNC server. 2459 2460 Following the display value there may be one or more option flags 2461 separated by commas. Valid options are 2462 2463 ``reverse=on|off`` 2464 Connect to a listening VNC client via a "reverse" connection. 2465 The client is specified by the display. For reverse network 2466 connections (host:d,``reverse``), the d argument is a TCP port 2467 number, not a display number. 2468 2469 ``websocket=on|off`` 2470 Opens an additional TCP listening port dedicated to VNC 2471 Websocket connections. If a bare websocket option is given, the 2472 Websocket port is 5700+display. An alternative port can be 2473 specified with the syntax ``websocket``\ =port. 2474 2475 If host is specified connections will only be allowed from this 2476 host. It is possible to control the websocket listen address 2477 independently, using the syntax ``websocket``\ =host:port. 2478 2479 If no TLS credentials are provided, the websocket connection 2480 runs in unencrypted mode. If TLS credentials are provided, the 2481 websocket connection requires encrypted client connections. 2482 2483 ``password=on|off`` 2484 Require that password based authentication is used for client 2485 connections. 2486 2487 The password must be set separately using the ``set_password`` 2488 command in the :ref:`QEMU monitor`. The 2489 syntax to change your password is: 2490 ``set_password <protocol> <password>`` where <protocol> could be 2491 either "vnc" or "spice". 2492 2493 If you would like to change <protocol> password expiration, you 2494 should use ``expire_password <protocol> <expiration-time>`` 2495 where expiration time could be one of the following options: 2496 now, never, +seconds or UNIX time of expiration, e.g. +60 to 2497 make password expire in 60 seconds, or 1335196800 to make 2498 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for 2499 this date and time). 2500 2501 You can also use keywords "now" or "never" for the expiration 2502 time to allow <protocol> password to expire immediately or never 2503 expire. 2504 2505 ``password-secret=<secret-id>`` 2506 Require that password based authentication is used for client 2507 connections, using the password provided by the ``secret`` 2508 object identified by ``secret-id``. 2509 2510 ``tls-creds=ID`` 2511 Provides the ID of a set of TLS credentials to use to secure the 2512 VNC server. They will apply to both the normal VNC server socket 2513 and the websocket socket (if enabled). Setting TLS credentials 2514 will cause the VNC server socket to enable the VeNCrypt auth 2515 mechanism. The credentials should have been previously created 2516 using the ``-object tls-creds`` argument. 2517 2518 ``tls-authz=ID`` 2519 Provides the ID of the QAuthZ authorization object against which 2520 the client's x509 distinguished name will validated. This object 2521 is only resolved at time of use, so can be deleted and recreated 2522 on the fly while the VNC server is active. If missing, it will 2523 default to denying access. 2524 2525 ``sasl=on|off`` 2526 Require that the client use SASL to authenticate with the VNC 2527 server. The exact choice of authentication method used is 2528 controlled from the system / user's SASL configuration file for 2529 the 'qemu' service. This is typically found in 2530 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, 2531 an environment variable SASL\_CONF\_PATH can be used to make it 2532 search alternate locations for the service config. While some 2533 SASL auth methods can also provide data encryption (eg GSSAPI), 2534 it is recommended that SASL always be combined with the 'tls' 2535 and 'x509' settings to enable use of SSL and server 2536 certificates. This ensures a data encryption preventing 2537 compromise of authentication credentials. See the 2538 :ref:`VNC security` section in the System Emulation Users Guide 2539 for details on using SASL authentication. 2540 2541 ``sasl-authz=ID`` 2542 Provides the ID of the QAuthZ authorization object against which 2543 the client's SASL username will validated. This object is only 2544 resolved at time of use, so can be deleted and recreated on the 2545 fly while the VNC server is active. If missing, it will default 2546 to denying access. 2547 2548 ``acl=on|off`` 2549 Legacy method for enabling authorization of clients against the 2550 x509 distinguished name and SASL username. It results in the 2551 creation of two ``authz-list`` objects with IDs of 2552 ``vnc.username`` and ``vnc.x509dname``. The rules for these 2553 objects must be configured with the HMP ACL commands. 2554 2555 This option is deprecated and should no longer be used. The new 2556 ``sasl-authz`` and ``tls-authz`` options are a replacement. 2557 2558 ``lossy=on|off`` 2559 Enable lossy compression methods (gradient, JPEG, ...). If this 2560 option is set, VNC client may receive lossy framebuffer updates 2561 depending on its encoding settings. Enabling this option can 2562 save a lot of bandwidth at the expense of quality. 2563 2564 ``non-adaptive=on|off`` 2565 Disable adaptive encodings. Adaptive encodings are enabled by 2566 default. An adaptive encoding will try to detect frequently 2567 updated screen regions, and send updates in these regions using 2568 a lossy encoding (like JPEG). This can be really helpful to save 2569 bandwidth when playing videos. Disabling adaptive encodings 2570 restores the original static behavior of encodings like Tight. 2571 2572 ``share=[allow-exclusive|force-shared|ignore]`` 2573 Set display sharing policy. 'allow-exclusive' allows clients to 2574 ask for exclusive access. As suggested by the rfb spec this is 2575 implemented by dropping other connections. Connecting multiple 2576 clients in parallel requires all clients asking for a shared 2577 session (vncviewer: -shared switch). This is the default. 2578 'force-shared' disables exclusive client access. Useful for 2579 shared desktop sessions, where you don't want someone forgetting 2580 specify -shared disconnect everybody else. 'ignore' completely 2581 ignores the shared flag and allows everybody connect 2582 unconditionally. Doesn't conform to the rfb spec but is 2583 traditional QEMU behavior. 2584 2585 ``key-delay-ms`` 2586 Set keyboard delay, for key down and key up events, in 2587 milliseconds. Default is 10. Keyboards are low-bandwidth 2588 devices, so this slowdown can help the device and guest to keep 2589 up and not lose events in case events are arriving in bulk. 2590 Possible causes for the latter are flaky network connections, or 2591 scripts for automated testing. 2592 2593 ``audiodev=audiodev`` 2594 Use the specified audiodev when the VNC client requests audio 2595 transmission. When not using an -audiodev argument, this option 2596 must be omitted, otherwise is must be present and specify a 2597 valid audiodev. 2598 2599 ``power-control=on|off`` 2600 Permit the remote client to issue shutdown, reboot or reset power 2601 control requests. 2602ERST 2603 2604ARCHHEADING(, QEMU_ARCH_I386) 2605 2606ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2607 2608DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2609 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2610 QEMU_ARCH_I386) 2611SRST 2612``-win2k-hack`` 2613 Use it when installing Windows 2000 to avoid a disk full bug. After 2614 Windows 2000 is installed, you no longer need this option (this 2615 option slows down the IDE transfers). 2616ERST 2617 2618DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2619 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2620 QEMU_ARCH_I386) 2621SRST 2622``-no-fd-bootchk`` 2623 Disable boot signature checking for floppy disks in BIOS. May be 2624 needed to boot from old floppy disks. 2625ERST 2626 2627DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2628 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2629SRST 2630``-no-acpi`` 2631 Disable ACPI (Advanced Configuration and Power Interface) support. 2632 Use it if your guest OS complains about ACPI problems (PC target 2633 machine only). 2634ERST 2635 2636DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2637 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2638SRST 2639``-no-hpet`` 2640 Disable HPET support. Deprecated, use '-machine hpet=off' instead. 2641ERST 2642 2643DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2644 "-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" 2645 " ACPI table description\n", QEMU_ARCH_I386) 2646SRST 2647``-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]...]`` 2648 Add ACPI table with specified header fields and context from 2649 specified files. For file=, take whole ACPI table from the specified 2650 files, including all ACPI headers (possible overridden by other 2651 options). For data=, only data portion of the table is used, all 2652 header information is specified in the command line. If a SLIC table 2653 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id 2654 fields will override the same in the RSDT and the FADT (a.k.a. 2655 FACP), in order to ensure the field matches required by the 2656 Microsoft SLIC spec and the ACPI spec. 2657ERST 2658 2659DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2660 "-smbios file=binary\n" 2661 " load SMBIOS entry from binary file\n" 2662 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2663 " [,uefi=on|off]\n" 2664 " specify SMBIOS type 0 fields\n" 2665 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2666 " [,uuid=uuid][,sku=str][,family=str]\n" 2667 " specify SMBIOS type 1 fields\n" 2668 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2669 " [,asset=str][,location=str]\n" 2670 " specify SMBIOS type 2 fields\n" 2671 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2672 " [,sku=str]\n" 2673 " specify SMBIOS type 3 fields\n" 2674 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2675 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n" 2676 " [,processor-id=%d]\n" 2677 " specify SMBIOS type 4 fields\n" 2678 "-smbios type=8[,external_reference=str][,internal_reference=str][,connector_type=%d][,port_type=%d]\n" 2679 " specify SMBIOS type 8 fields\n" 2680 "-smbios type=11[,value=str][,path=filename]\n" 2681 " specify SMBIOS type 11 fields\n" 2682 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2683 " [,asset=str][,part=str][,speed=%d]\n" 2684 " specify SMBIOS type 17 fields\n" 2685 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n" 2686 " specify SMBIOS type 41 fields\n", 2687 QEMU_ARCH_I386 | QEMU_ARCH_ARM | QEMU_ARCH_LOONGARCH) 2688SRST 2689``-smbios file=binary`` 2690 Load SMBIOS entry from binary file. 2691 2692``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]`` 2693 Specify SMBIOS type 0 fields 2694 2695``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]`` 2696 Specify SMBIOS type 1 fields 2697 2698``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]`` 2699 Specify SMBIOS type 2 fields 2700 2701``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]`` 2702 Specify SMBIOS type 3 fields 2703 2704``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str][,processor-id=%d]`` 2705 Specify SMBIOS type 4 fields 2706 2707``-smbios type=11[,value=str][,path=filename]`` 2708 Specify SMBIOS type 11 fields 2709 2710 This argument can be repeated multiple times, and values are added in the order they are parsed. 2711 Applications intending to use OEM strings data are encouraged to use their application name as 2712 a prefix for the value string. This facilitates passing information for multiple applications 2713 concurrently. 2714 2715 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax 2716 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes. 2717 2718 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to 2719 the SMBIOS table in the order in which they appear. 2720 2721 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535 2722 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the 2723 guest. Instead it should be used as a indicator to inform the guest where to locate the real 2724 data set, for example, by specifying the serial ID of a block device. 2725 2726 An example passing three strings is 2727 2728 .. parsed-literal:: 2729 2730 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\ 2731 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\ 2732 path=/some/file/with/oemstringsdata.txt 2733 2734 In the guest OS this is visible with the ``dmidecode`` command 2735 2736 .. parsed-literal:: 2737 2738 $ dmidecode -t 11 2739 Handle 0x0E00, DMI type 11, 5 bytes 2740 OEM Strings 2741 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/ 2742 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os 2743 String 3: myapp:some extra data 2744 2745 2746``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]`` 2747 Specify SMBIOS type 17 fields 2748 2749``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]`` 2750 Specify SMBIOS type 41 fields 2751 2752 This argument can be repeated multiple times. Its main use is to allow network interfaces be created 2753 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface 2754 position on the PCI bus. 2755 2756 Here is an example of use: 2757 2758 .. parsed-literal:: 2759 2760 -netdev user,id=internet \\ 2761 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\ 2762 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev 2763 2764 In the guest OS, the device should then appear as ``eno1``: 2765 2766 ..parsed-literal:: 2767 2768 $ ip -brief l 2769 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP> 2770 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP> 2771 2772 Currently, the PCI device has to be attached to the root bus. 2773 2774ERST 2775 2776DEFHEADING() 2777 2778DEFHEADING(Network options:) 2779 2780DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2781#ifdef CONFIG_SLIRP 2782 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n" 2783 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2784 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2785 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2786 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2787#ifndef _WIN32 2788 "[,smb=dir[,smbserver=addr]]\n" 2789#endif 2790 " configure a user mode network backend with ID 'str',\n" 2791 " its DHCP server and optional services\n" 2792#endif 2793#ifdef _WIN32 2794 "-netdev tap,id=str,ifname=name\n" 2795 " configure a host TAP network backend with ID 'str'\n" 2796#else 2797 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2798 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2799 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2800 " [,poll-us=n]\n" 2801 " configure a host TAP network backend with ID 'str'\n" 2802 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2803 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2804 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2805 " to deconfigure it\n" 2806 " use '[down]script=no' to disable script execution\n" 2807 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2808 " configure it\n" 2809 " use 'fd=h' to connect to an already opened TAP interface\n" 2810 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2811 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2812 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2813 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2814 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2815 " use vhost=on to enable experimental in kernel accelerator\n" 2816 " (only has effect for virtio guests which use MSIX)\n" 2817 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2818 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2819 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2820 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2821 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n" 2822 " spent on busy polling for vhost net\n" 2823 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2824 " configure a host TAP network backend with ID 'str' that is\n" 2825 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2826 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2827#endif 2828#ifdef __linux__ 2829 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2830 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n" 2831 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n" 2832 " [,rxcookie=rxcookie][,offset=offset]\n" 2833 " configure a network backend with ID 'str' connected to\n" 2834 " an Ethernet over L2TPv3 pseudowire.\n" 2835 " Linux kernel 3.3+ as well as most routers can talk\n" 2836 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2837 " VM to a router and even VM to Host. It is a nearly-universal\n" 2838 " standard (RFC3931). Note - this implementation uses static\n" 2839 " pre-configured tunnels (same as the Linux kernel).\n" 2840 " use 'src=' to specify source address\n" 2841 " use 'dst=' to specify destination address\n" 2842 " use 'udp=on' to specify udp encapsulation\n" 2843 " use 'srcport=' to specify source udp port\n" 2844 " use 'dstport=' to specify destination udp port\n" 2845 " use 'ipv6=on' to force v6\n" 2846 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2847 " well as a weak security measure\n" 2848 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2849 " use 'txcookie=0x012345678' to specify a txcookie\n" 2850 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2851 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2852 " use 'pincounter=on' to work around broken counter handling in peer\n" 2853 " use 'offset=X' to add an extra offset between header and data\n" 2854#endif 2855 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2856 " configure a network backend to connect to another network\n" 2857 " using a socket connection\n" 2858 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2859 " configure a network backend to connect to a multicast maddr and port\n" 2860 " use 'localaddr=addr' to specify the host address to send packets from\n" 2861 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2862 " configure a network backend to connect to another network\n" 2863 " using an UDP tunnel\n" 2864 "-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" 2865 "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect=seconds]\n" 2866 "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect=seconds]\n" 2867 " configure a network backend to connect to another network\n" 2868 " using a socket connection in stream mode.\n" 2869 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n" 2870 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]\n" 2871 " configure a network backend to connect to a multicast maddr and port\n" 2872 " use ``local.host=addr`` to specify the host address to send packets from\n" 2873 "-netdev dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]\n" 2874 "-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]\n" 2875 "-netdev dgram,id=str,local.type=fd,local.str=file-descriptor\n" 2876 " configure a network backend to connect to another network\n" 2877 " using an UDP tunnel\n" 2878#ifdef CONFIG_VDE 2879 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2880 " configure a network backend to connect to port 'n' of a vde switch\n" 2881 " running on host and listening for incoming connections on 'socketpath'.\n" 2882 " Use group 'groupname' and mode 'octalmode' to change default\n" 2883 " ownership and permissions for communication port.\n" 2884#endif 2885#ifdef CONFIG_NETMAP 2886 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2887 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2888 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2889 " netmap device, defaults to '/dev/netmap')\n" 2890#endif 2891#ifdef CONFIG_AF_XDP 2892 "-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off]\n" 2893 " [,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]\n" 2894 " attach to the existing network interface 'name' with AF_XDP socket\n" 2895 " use 'mode=MODE' to specify an XDP program attach mode\n" 2896 " use 'force-copy=on|off' to force XDP copy mode even if device supports zero-copy (default: off)\n" 2897 " use 'inhibit=on|off' to inhibit loading of a default XDP program (default: off)\n" 2898 " with inhibit=on,\n" 2899 " use 'sock-fds' to provide file descriptors for already open AF_XDP sockets\n" 2900 " added to a socket map in XDP program. One socket per queue.\n" 2901 " use 'queues=n' to specify how many queues of a multiqueue interface should be used\n" 2902 " use 'start-queue=m' to specify the first queue that should be used\n" 2903#endif 2904#ifdef CONFIG_POSIX 2905 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2906 " configure a vhost-user network, backed by a chardev 'dev'\n" 2907#endif 2908#ifdef __linux__ 2909 "-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n" 2910 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n" 2911 " use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n" 2912 " use 'vhostfd=h' to connect to an already opened vhost vdpa device\n" 2913#endif 2914#ifdef CONFIG_VMNET 2915 "-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n" 2916 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2917 " configure a vmnet network backend in host mode with ID 'str',\n" 2918 " isolate this interface from others with 'isolated',\n" 2919 " configure the address range and choose a subnet mask,\n" 2920 " specify network UUID 'uuid' to disable DHCP and interact with\n" 2921 " vmnet-host interfaces within this isolated network\n" 2922 "-netdev vmnet-shared,id=str[,isolated=on|off][,nat66-prefix=addr]\n" 2923 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2924 " configure a vmnet network backend in shared mode with ID 'str',\n" 2925 " configure the address range and choose a subnet mask,\n" 2926 " set IPv6 ULA prefix (of length 64) to use for internal network,\n" 2927 " isolate this interface from others with 'isolated'\n" 2928 "-netdev vmnet-bridged,id=str,ifname=name[,isolated=on|off]\n" 2929 " configure a vmnet network backend in bridged mode with ID 'str',\n" 2930 " use 'ifname=name' to select a physical network interface to be bridged,\n" 2931 " isolate this interface from others with 'isolated'\n" 2932#endif 2933 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2934 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2935DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2936 "-nic [tap|bridge|" 2937#ifdef CONFIG_SLIRP 2938 "user|" 2939#endif 2940#ifdef __linux__ 2941 "l2tpv3|" 2942#endif 2943#ifdef CONFIG_VDE 2944 "vde|" 2945#endif 2946#ifdef CONFIG_NETMAP 2947 "netmap|" 2948#endif 2949#ifdef CONFIG_AF_XDP 2950 "af-xdp|" 2951#endif 2952#ifdef CONFIG_POSIX 2953 "vhost-user|" 2954#endif 2955#ifdef CONFIG_VMNET 2956 "vmnet-host|vmnet-shared|vmnet-bridged|" 2957#endif 2958 "socket][,option][,...][mac=macaddr]\n" 2959 " initialize an on-board / default host NIC (using MAC address\n" 2960 " macaddr) and connect it to the given host network backend\n" 2961 "-nic none use it alone to have zero network devices (the default is to\n" 2962 " provided a 'user' network connection)\n", 2963 QEMU_ARCH_ALL) 2964DEF("net", HAS_ARG, QEMU_OPTION_net, 2965 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2966 " configure or create an on-board (or machine default) NIC and\n" 2967 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2968 "-net [" 2969#ifdef CONFIG_SLIRP 2970 "user|" 2971#endif 2972 "tap|" 2973 "bridge|" 2974#ifdef CONFIG_VDE 2975 "vde|" 2976#endif 2977#ifdef CONFIG_NETMAP 2978 "netmap|" 2979#endif 2980#ifdef CONFIG_AF_XDP 2981 "af-xdp|" 2982#endif 2983#ifdef CONFIG_VMNET 2984 "vmnet-host|vmnet-shared|vmnet-bridged|" 2985#endif 2986 "socket][,option][,option][,...]\n" 2987 " old way to initialize a host network interface\n" 2988 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2989SRST 2990``-nic [tap|bridge|user|l2tpv3|vde|netmap|af-xdp|vhost-user|socket][,...][,mac=macaddr][,model=mn]`` 2991 This option is a shortcut for configuring both the on-board 2992 (default) guest NIC hardware and the host network backend in one go. 2993 The host backend options are the same as with the corresponding 2994 ``-netdev`` options below. The guest NIC model can be set with 2995 ``model=modelname``. Use ``model=help`` to list the available device 2996 types. The hardware MAC address can be set with ``mac=macaddr``. 2997 2998 The following two example do exactly the same, to show how ``-nic`` 2999 can be used to shorten the command line length: 3000 3001 .. parsed-literal:: 3002 3003 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 3004 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 3005 3006``-nic none`` 3007 Indicate that no network devices should be configured. It is used to 3008 override the default configuration (default NIC with "user" host 3009 network backend) which is activated if no other networking options 3010 are provided. 3011 3012``-netdev user,id=id[,option][,option][,...]`` 3013 Configure user mode host network backend which requires no 3014 administrator privilege to run. Valid options are: 3015 3016 ``id=id`` 3017 Assign symbolic name for use in monitor commands. 3018 3019 ``ipv4=on|off and ipv6=on|off`` 3020 Specify that either IPv4 or IPv6 must be enabled. If neither is 3021 specified both protocols are enabled. 3022 3023 ``net=addr[/mask]`` 3024 Set IP network address the guest will see. Optionally specify 3025 the netmask, either in the form a.b.c.d or as number of valid 3026 top-most bits. Default is 10.0.2.0/24. 3027 3028 ``host=addr`` 3029 Specify the guest-visible address of the host. Default is the 3030 2nd IP in the guest network, i.e. x.x.x.2. 3031 3032 ``ipv6-net=addr[/int]`` 3033 Set IPv6 network address the guest will see (default is 3034 fec0::/64). The network prefix is given in the usual hexadecimal 3035 IPv6 address notation. The prefix size is optional, and is given 3036 as the number of valid top-most bits (default is 64). 3037 3038 ``ipv6-host=addr`` 3039 Specify the guest-visible IPv6 address of the host. Default is 3040 the 2nd IPv6 in the guest network, i.e. xxxx::2. 3041 3042 ``restrict=on|off`` 3043 If this option is enabled, the guest will be isolated, i.e. it 3044 will not be able to contact the host and no guest IP packets 3045 will be routed over the host to the outside. This option does 3046 not affect any explicitly set forwarding rules. 3047 3048 ``hostname=name`` 3049 Specifies the client hostname reported by the built-in DHCP 3050 server. 3051 3052 ``dhcpstart=addr`` 3053 Specify the first of the 16 IPs the built-in DHCP server can 3054 assign. Default is the 15th to 31st IP in the guest network, 3055 i.e. x.x.x.15 to x.x.x.31. 3056 3057 ``dns=addr`` 3058 Specify the guest-visible address of the virtual nameserver. The 3059 address must be different from the host address. Default is the 3060 3rd IP in the guest network, i.e. x.x.x.3. 3061 3062 ``ipv6-dns=addr`` 3063 Specify the guest-visible address of the IPv6 virtual 3064 nameserver. The address must be different from the host address. 3065 Default is the 3rd IP in the guest network, i.e. xxxx::3. 3066 3067 ``dnssearch=domain`` 3068 Provides an entry for the domain-search list sent by the 3069 built-in DHCP server. More than one domain suffix can be 3070 transmitted by specifying this option multiple times. If 3071 supported, this will cause the guest to automatically try to 3072 append the given domain suffix(es) in case a domain name can not 3073 be resolved. 3074 3075 Example: 3076 3077 .. parsed-literal:: 3078 3079 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 3080 3081 ``domainname=domain`` 3082 Specifies the client domain name reported by the built-in DHCP 3083 server. 3084 3085 ``tftp=dir`` 3086 When using the user mode network stack, activate a built-in TFTP 3087 server. The files in dir will be exposed as the root of a TFTP 3088 server. The TFTP client on the guest must be configured in 3089 binary mode (use the command ``bin`` of the Unix TFTP client). 3090 3091 ``tftp-server-name=name`` 3092 In BOOTP reply, broadcast name as the "TFTP server name" 3093 (RFC2132 option 66). This can be used to advise the guest to 3094 load boot files or configurations from a different server than 3095 the host address. 3096 3097 ``bootfile=file`` 3098 When using the user mode network stack, broadcast file as the 3099 BOOTP filename. In conjunction with ``tftp``, this can be used 3100 to network boot a guest from a local directory. 3101 3102 Example (using pxelinux): 3103 3104 .. parsed-literal:: 3105 3106 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\ 3107 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 3108 3109 ``smb=dir[,smbserver=addr]`` 3110 When using the user mode network stack, activate a built-in SMB 3111 server so that Windows OSes can access to the host files in 3112 ``dir`` transparently. The IP address of the SMB server can be 3113 set to addr. By default the 4th IP in the guest network is used, 3114 i.e. x.x.x.4. 3115 3116 In the guest Windows OS, the line: 3117 3118 :: 3119 3120 10.0.2.4 smbserver 3121 3122 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows 3123 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows 3124 NT/2000). 3125 3126 Then ``dir`` can be accessed in ``\\smbserver\qemu``. 3127 3128 Note that a SAMBA server must be installed on the host OS. 3129 3130 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport`` 3131 Redirect incoming TCP or UDP connections to the host port 3132 hostport to the guest IP address guestaddr on guest port 3133 guestport. If guestaddr is not specified, its value is x.x.x.15 3134 (default first address given by the built-in DHCP server). By 3135 specifying hostaddr, the rule can be bound to a specific host 3136 interface. If no connection type is set, TCP is used. This 3137 option can be given multiple times. 3138 3139 For example, to redirect host X11 connection from screen 1 to 3140 guest screen 0, use the following: 3141 3142 .. parsed-literal:: 3143 3144 # on the host 3145 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 3146 # this host xterm should open in the guest X11 server 3147 xterm -display :1 3148 3149 To redirect telnet connections from host port 5555 to telnet 3150 port on the guest, use the following: 3151 3152 .. parsed-literal:: 3153 3154 # on the host 3155 |qemu_system| -nic user,hostfwd=tcp::5555-:23 3156 telnet localhost 5555 3157 3158 Then when you use on the host ``telnet localhost 5555``, you 3159 connect to the guest telnet server. 3160 3161 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command`` 3162 Forward guest TCP connections to the IP address server on port 3163 port to the character device dev or to a program executed by 3164 cmd:command which gets spawned for each connection. This option 3165 can be given multiple times. 3166 3167 You can either use a chardev directly and have that one used 3168 throughout QEMU's lifetime, like in the following example: 3169 3170 .. parsed-literal:: 3171 3172 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 3173 # the guest accesses it 3174 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 3175 3176 Or you can execute a command on every TCP connection established 3177 by the guest, so that QEMU behaves similar to an inetd process 3178 for that virtual server: 3179 3180 .. parsed-literal:: 3181 3182 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 3183 # and connect the TCP stream to its stdin/stdout 3184 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 3185 3186``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` 3187 Configure a host TAP network backend with ID id. 3188 3189 Use the network script file to configure it and the network script 3190 dfile to deconfigure it. If name is not provided, the OS 3191 automatically provides one. The default network configure script is 3192 ``/etc/qemu-ifup`` and the default network deconfigure script is 3193 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to 3194 disable script execution. 3195 3196 If running QEMU as an unprivileged user, use the network helper 3197 to configure the TAP interface and attach it to the bridge. 3198 The default network helper executable is 3199 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3200 ``br0``. 3201 3202 ``fd``\ =h can be used to specify the handle of an already opened 3203 host TAP interface. 3204 3205 Examples: 3206 3207 .. parsed-literal:: 3208 3209 #launch a QEMU instance with the default network script 3210 |qemu_system| linux.img -nic tap 3211 3212 .. parsed-literal:: 3213 3214 #launch a QEMU instance with two NICs, each one connected 3215 #to a TAP device 3216 |qemu_system| linux.img \\ 3217 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\ 3218 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 3219 3220 .. parsed-literal:: 3221 3222 #launch a QEMU instance with the default network helper to 3223 #connect a TAP device to bridge br0 3224 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3225 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 3226 3227``-netdev bridge,id=id[,br=bridge][,helper=helper]`` 3228 Connect a host TAP network interface to a host bridge device. 3229 3230 Use the network helper helper to configure the TAP interface and 3231 attach it to the bridge. The default network helper executable is 3232 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3233 ``br0``. 3234 3235 Examples: 3236 3237 .. parsed-literal:: 3238 3239 #launch a QEMU instance with the default network helper to 3240 #connect a TAP device to bridge br0 3241 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 3242 3243 .. parsed-literal:: 3244 3245 #launch a QEMU instance with the default network helper to 3246 #connect a TAP device to bridge qemubr0 3247 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 3248 3249``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]`` 3250 This host network backend can be used to connect the guest's network 3251 to another QEMU virtual machine using a TCP socket connection. If 3252 ``listen`` is specified, QEMU waits for incoming connections on port 3253 (host is optional). ``connect`` is used to connect to another QEMU 3254 instance using the ``listen`` option. ``fd``\ =h specifies an 3255 already opened TCP socket. 3256 3257 Example: 3258 3259 .. parsed-literal:: 3260 3261 # launch a first QEMU instance 3262 |qemu_system| linux.img \\ 3263 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3264 -netdev socket,id=n1,listen=:1234 3265 # connect the network of this instance to the network of the first instance 3266 |qemu_system| linux.img \\ 3267 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3268 -netdev socket,id=n2,connect=127.0.0.1:1234 3269 3270``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]`` 3271 Configure a socket host network backend to share the guest's network 3272 traffic with another QEMU virtual machines using a UDP multicast 3273 socket, effectively making a bus for every QEMU with same multicast 3274 address maddr and port. NOTES: 3275 3276 1. Several QEMU can be running on different hosts and share same bus 3277 (assuming correct multicast setup for these hosts). 3278 3279 2. mcast support is compatible with User Mode Linux (argument 3280 ``ethN=mcast``), see http://user-mode-linux.sf.net. 3281 3282 3. Use ``fd=h`` to specify an already opened UDP multicast socket. 3283 3284 Example: 3285 3286 .. parsed-literal:: 3287 3288 # launch one QEMU instance 3289 |qemu_system| linux.img \\ 3290 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3291 -netdev socket,id=n1,mcast=230.0.0.1:1234 3292 # launch another QEMU instance on same "bus" 3293 |qemu_system| linux.img \\ 3294 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3295 -netdev socket,id=n2,mcast=230.0.0.1:1234 3296 # launch yet another QEMU instance on same "bus" 3297 |qemu_system| linux.img \\ 3298 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\ 3299 -netdev socket,id=n3,mcast=230.0.0.1:1234 3300 3301 Example (User Mode Linux compat.): 3302 3303 .. parsed-literal:: 3304 3305 # launch QEMU instance (note mcast address selected is UML's default) 3306 |qemu_system| linux.img \\ 3307 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3308 -netdev socket,id=n1,mcast=239.192.168.1:1102 3309 # launch UML 3310 /path/to/linux ubd0=/path/to/root_fs eth0=mcast 3311 3312 Example (send packets from host's 1.2.3.4): 3313 3314 .. parsed-literal:: 3315 3316 |qemu_system| linux.img \\ 3317 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3318 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 3319 3320``-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]`` 3321 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931) 3322 is a popular protocol to transport Ethernet (and other Layer 2) data 3323 frames between two systems. It is present in routers, firewalls and 3324 the Linux kernel (from version 3.3 onwards). 3325 3326 This transport allows a VM to communicate to another VM, router or 3327 firewall directly. 3328 3329 ``src=srcaddr`` 3330 source address (mandatory) 3331 3332 ``dst=dstaddr`` 3333 destination address (mandatory) 3334 3335 ``udp`` 3336 select udp encapsulation (default is ip). 3337 3338 ``srcport=srcport`` 3339 source udp port. 3340 3341 ``dstport=dstport`` 3342 destination udp port. 3343 3344 ``ipv6`` 3345 force v6, otherwise defaults to v4. 3346 3347 ``rxcookie=rxcookie``; \ ``txcookie=txcookie`` 3348 Cookies are a weak form of security in the l2tpv3 specification. 3349 Their function is mostly to prevent misconfiguration. By default 3350 they are 32 bit. 3351 3352 ``cookie64`` 3353 Set cookie size to 64 bit instead of the default 32 3354 3355 ``counter=off`` 3356 Force a 'cut-down' L2TPv3 with no counter as in 3357 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 3358 3359 ``pincounter=on`` 3360 Work around broken counter handling in peer. This may also help 3361 on networks which have packet reorder. 3362 3363 ``offset=offset`` 3364 Add an extra offset between header and data 3365 3366 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to 3367 the bridge br-lan on the remote Linux host 1.2.3.4: 3368 3369 .. parsed-literal:: 3370 3371 # Setup tunnel on linux host using raw ip as encapsulation 3372 # on 1.2.3.4 3373 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\ 3374 encap udp udp_sport 16384 udp_dport 16384 3375 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\ 3376 0xFFFFFFFF peer_session_id 0xFFFFFFFF 3377 ifconfig vmtunnel0 mtu 1500 3378 ifconfig vmtunnel0 up 3379 brctl addif br-lan vmtunnel0 3380 3381 3382 # on 4.3.2.1 3383 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 3384 3385 |qemu_system| linux.img -device e1000,netdev=n1 \\ 3386 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 3387 3388``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]`` 3389 Configure VDE backend to connect to PORT n of a vde switch running 3390 on host and listening for incoming connections on socketpath. Use 3391 GROUP groupname and MODE octalmode to change default ownership and 3392 permissions for communication port. This option is only available if 3393 QEMU has been compiled with vde support enabled. 3394 3395 Example: 3396 3397 .. parsed-literal:: 3398 3399 # launch vde switch 3400 vde_switch -F -sock /tmp/myswitch 3401 # launch QEMU instance 3402 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch 3403 3404``-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off][,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]`` 3405 Configure AF_XDP backend to connect to a network interface 'name' 3406 using AF_XDP socket. A specific program attach mode for a default 3407 XDP program can be forced with 'mode', defaults to best-effort, 3408 where the likely most performant mode will be in use. Number of queues 3409 'n' should generally match the number or queues in the interface, 3410 defaults to 1. Traffic arriving on non-configured device queues will 3411 not be delivered to the network backend. 3412 3413 .. parsed-literal:: 3414 3415 # set number of queues to 4 3416 ethtool -L eth0 combined 4 3417 # launch QEMU instance 3418 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3419 -netdev af-xdp,id=n1,ifname=eth0,queues=4 3420 3421 'start-queue' option can be specified if a particular range of queues 3422 [m, m + n] should be in use. For example, this is may be necessary in 3423 order to use certain NICs in native mode. Kernel allows the driver to 3424 create a separate set of XDP queues on top of regular ones, and only 3425 these queues can be used for AF_XDP sockets. NICs that work this way 3426 may also require an additional traffic redirection with ethtool to these 3427 special queues. 3428 3429 .. parsed-literal:: 3430 3431 # set number of queues to 1 3432 ethtool -L eth0 combined 1 3433 # redirect all the traffic to the second queue (id: 1) 3434 # note: drivers may require non-empty key/mask pair. 3435 ethtool -N eth0 flow-type ether \\ 3436 dst 00:00:00:00:00:00 m FF:FF:FF:FF:FF:FE action 1 3437 ethtool -N eth0 flow-type ether \\ 3438 dst 00:00:00:00:00:01 m FF:FF:FF:FF:FF:FE action 1 3439 # launch QEMU instance 3440 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3441 -netdev af-xdp,id=n1,ifname=eth0,queues=1,start-queue=1 3442 3443 XDP program can also be loaded externally. In this case 'inhibit' option 3444 should be set to 'on' and 'sock-fds' provided with file descriptors for 3445 already open but not bound XDP sockets already added to a socket map for 3446 corresponding queues. One socket per queue. 3447 3448 .. parsed-literal:: 3449 3450 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3451 -netdev af-xdp,id=n1,ifname=eth0,queues=3,inhibit=on,sock-fds=15:16:17 3452 3453``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` 3454 Establish a vhost-user netdev, backed by a chardev id. The chardev 3455 should be a unix domain socket backed one. The vhost-user uses a 3456 specifically defined protocol to pass vhost ioctl replacement 3457 messages to an application on the other end of the socket. On 3458 non-MSIX guests, the feature can be forced with vhostforce. Use 3459 'queues=n' to specify the number of queues to be created for 3460 multiqueue vhost-user. 3461 3462 Example: 3463 3464 :: 3465 3466 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 3467 -numa node,memdev=mem \ 3468 -chardev socket,id=chr0,path=/path/to/socket \ 3469 -netdev type=vhost-user,id=net0,chardev=chr0 \ 3470 -device virtio-net-pci,netdev=net0 3471 3472``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]`` 3473 Establish a vhost-vdpa netdev. 3474 3475 vDPA device is a device that uses a datapath which complies with 3476 the virtio specifications with a vendor specific control path. 3477 vDPA devices can be both physically located on the hardware or 3478 emulated by software. 3479 3480``-netdev hubport,id=id,hubid=hubid[,netdev=nd]`` 3481 Create a hub port on the emulated hub with ID hubid. 3482 3483 The hubport netdev lets you connect a NIC to a QEMU emulated hub 3484 instead of a single netdev. Alternatively, you can also connect the 3485 hubport to another netdev with ID nd by using the ``netdev=nd`` 3486 option. 3487 3488``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]`` 3489 Legacy option to configure or create an on-board (or machine 3490 default) Network Interface Card(NIC) and connect it either to the 3491 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd. 3492 If model is omitted, then the default NIC model associated with the 3493 machine type is used. Note that the default NIC model may change in 3494 future QEMU releases, so it is highly recommended to always specify 3495 a model. Optionally, the MAC address can be changed to mac, the 3496 device address set to addr (PCI cards only), and a name can be 3497 assigned for use in monitor commands. Optionally, for PCI cards, you 3498 can specify the number v of MSI-X vectors that the card should have; 3499 this option currently only affects virtio cards; set v = 0 to 3500 disable MSI-X. If no ``-net`` option is specified, a single NIC is 3501 created. QEMU can emulate several different models of network card. 3502 Use ``-net nic,model=help`` for a list of available devices for your 3503 target. 3504 3505``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]`` 3506 Configure a host network backend (with the options corresponding to 3507 the same ``-netdev`` option) and connect it to the emulated hub 0 3508 (the default hub). Use name to specify the name of the hub port. 3509ERST 3510 3511DEFHEADING() 3512 3513DEFHEADING(Character device options:) 3514 3515DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 3516 "-chardev help\n" 3517 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3518 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n" 3519 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" 3520 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 3521 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" 3522 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" 3523 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 3524 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n" 3525 " [,logfile=PATH][,logappend=on|off]\n" 3526 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3527 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 3528 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3529 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 3530 "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3531 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3532#ifdef _WIN32 3533 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3534 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3535#else 3536 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3537 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 3538#endif 3539#ifdef CONFIG_BRLAPI 3540 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3541#endif 3542#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 3543 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 3544 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3545#endif 3546#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 3547 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3548#endif 3549#if defined(CONFIG_SPICE) 3550 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3551 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3552#endif 3553 , QEMU_ARCH_ALL 3554) 3555 3556SRST 3557The general form of a character device option is: 3558 3559``-chardev backend,id=id[,mux=on|off][,options]`` 3560 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, 3561 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, 3562 ``pty``, ``stdio``, ``braille``, ``parallel``, 3563 ``spicevmc``, ``spiceport``. The specific backend will determine the 3564 applicable options. 3565 3566 Use ``-chardev help`` to print all available chardev backend types. 3567 3568 All devices must have an id, which can be any string up to 127 3569 characters long. It is used to uniquely identify this device in 3570 other command line directives. 3571 3572 A character device may be used in multiplexing mode by multiple 3573 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is 3574 a "1:N" device, and here the "1" end is your specified chardev 3575 backend, and the "N" end is the various parts of QEMU that can talk 3576 to a chardev. If you create a chardev with ``id=myid`` and 3577 ``mux=on``, QEMU will create a multiplexer with your specified ID, 3578 and you can then configure multiple front ends to use that chardev 3579 ID for their input/output. Up to four different front ends can be 3580 connected to a single multiplexed chardev. (Without multiplexing 3581 enabled, a chardev can only be used by a single front end.) For 3582 instance you could use this to allow a single stdio chardev to be 3583 used by two serial ports and the QEMU monitor: 3584 3585 :: 3586 3587 -chardev stdio,mux=on,id=char0 \ 3588 -mon chardev=char0,mode=readline \ 3589 -serial chardev:char0 \ 3590 -serial chardev:char0 3591 3592 You can have more than one multiplexer in a system configuration; 3593 for instance you could have a TCP port multiplexed between UART 0 3594 and UART 1, and stdio multiplexed between the QEMU monitor and a 3595 parallel port: 3596 3597 :: 3598 3599 -chardev stdio,mux=on,id=char0 \ 3600 -mon chardev=char0,mode=readline \ 3601 -parallel chardev:char0 \ 3602 -chardev tcp,...,mux=on,id=char1 \ 3603 -serial chardev:char1 \ 3604 -serial chardev:char1 3605 3606 When you're using a multiplexed character device, some escape 3607 sequences are interpreted in the input. See the chapter about 3608 :ref:`keys in the character backend multiplexer` in the 3609 System Emulation Users Guide for more details. 3610 3611 Note that some other command line options may implicitly create 3612 multiplexed character backends; for instance ``-serial mon:stdio`` 3613 creates a multiplexed stdio backend connected to the serial port and 3614 the QEMU monitor, and ``-nographic`` also multiplexes the console 3615 and the monitor to stdio. 3616 3617 There is currently no support for multiplexing in the other 3618 direction (where a single QEMU front end takes input and output from 3619 multiple chardevs). 3620 3621 Every backend supports the ``logfile`` option, which supplies the 3622 path to a file to record all data transmitted via the backend. The 3623 ``logappend`` option controls whether the log file will be truncated 3624 or appended to when opened. 3625 3626The available backends are: 3627 3628``-chardev null,id=id`` 3629 A void device. This device will not emit any data, and will drop any 3630 data it receives. The null backend does not take any options. 3631 3632``-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]`` 3633 Create a two-way stream socket, which can be either a TCP or a unix 3634 socket. A unix socket will be created if ``path`` is specified. 3635 Behaviour is undefined if TCP options are specified for a unix 3636 socket. 3637 3638 ``server=on|off`` specifies that the socket shall be a listening socket. 3639 3640 ``wait=on|off`` specifies that QEMU should not block waiting for a client 3641 to connect to a listening socket. 3642 3643 ``telnet=on|off`` specifies that traffic on the socket should interpret 3644 telnet escape sequences. 3645 3646 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for 3647 communication. 3648 3649 ``reconnect`` sets the timeout for reconnecting on non-server 3650 sockets when the remote end goes away. qemu will delay this many 3651 seconds and then attempt to reconnect. Zero disables reconnecting, 3652 and is the default. 3653 3654 ``tls-creds`` requests enablement of the TLS protocol for 3655 encryption, and specifies the id of the TLS credentials to use for 3656 the handshake. The credentials must be previously created with the 3657 ``-object tls-creds`` argument. 3658 3659 ``tls-auth`` provides the ID of the QAuthZ authorization object 3660 against which the client's x509 distinguished name will be 3661 validated. This object is only resolved at time of use, so can be 3662 deleted and recreated on the fly while the chardev server is active. 3663 If missing, it will default to denying access. 3664 3665 TCP and unix socket options are given below: 3666 3667 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]`` 3668 ``host`` for a listening socket specifies the local address to 3669 be bound. For a connecting socket species the remote host to 3670 connect to. ``host`` is optional for listening sockets. If not 3671 specified it defaults to ``0.0.0.0``. 3672 3673 ``port`` for a listening socket specifies the local port to be 3674 bound. For a connecting socket specifies the port on the remote 3675 host to connect to. ``port`` can be given as either a port 3676 number or a service name. ``port`` is required. 3677 3678 ``to`` is only relevant to listening sockets. If it is 3679 specified, and ``port`` cannot be bound, QEMU will attempt to 3680 bind to subsequent ports up to and including ``to`` until it 3681 succeeds. ``to`` must be specified as a port number. 3682 3683 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 3684 or IPv6 must be used. If neither is specified the socket may 3685 use either protocol. 3686 3687 ``nodelay=on|off`` disables the Nagle algorithm. 3688 3689 ``unix options: path=path[,abstract=on|off][,tight=on|off]`` 3690 ``path`` specifies the local path of the unix socket. ``path`` 3691 is required. 3692 ``abstract=on|off`` specifies the use of the abstract socket namespace, 3693 rather than the filesystem. Optional, defaults to false. 3694 ``tight=on|off`` sets the socket length of abstract sockets to their minimum, 3695 rather than the full sun_path length. Optional, defaults to true. 3696 3697``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4=on|off][,ipv6=on|off]`` 3698 Sends all traffic from the guest to a remote host over UDP. 3699 3700 ``host`` specifies the remote host to connect to. If not specified 3701 it defaults to ``localhost``. 3702 3703 ``port`` specifies the port on the remote host to connect to. 3704 ``port`` is required. 3705 3706 ``localaddr`` specifies the local address to bind to. If not 3707 specified it defaults to ``0.0.0.0``. 3708 3709 ``localport`` specifies the local port to bind to. If not specified 3710 any available local port will be used. 3711 3712 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used. 3713 If neither is specified the device may use either protocol. 3714 3715``-chardev msmouse,id=id`` 3716 Forward QEMU's emulated msmouse events to the guest. ``msmouse`` 3717 does not take any options. 3718 3719``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` 3720 Connect to a QEMU text console. ``vc`` may optionally be given a 3721 specific size. 3722 3723 ``width`` and ``height`` specify the width and height respectively 3724 of the console, in pixels. 3725 3726 ``cols`` and ``rows`` specify that the console be sized to fit a 3727 text console with the given dimensions. 3728 3729``-chardev ringbuf,id=id[,size=size]`` 3730 Create a ring buffer with fixed size ``size``. size must be a power 3731 of two and defaults to ``64K``. 3732 3733``-chardev file,id=id,path=path[,input-path=input-path]`` 3734 Log all traffic received from the guest to a file. 3735 3736 ``path`` specifies the path of the file to be opened. This file will 3737 be created if it does not already exist, and overwritten if it does. 3738 ``path`` is required. 3739 3740 If ``input-path`` is specified, this is the path of a second file 3741 which will be used for input. If ``input-path`` is not specified, 3742 no input will be available from the chardev. 3743 3744 Note that ``input-path`` is not supported on Windows hosts. 3745 3746``-chardev pipe,id=id,path=path`` 3747 Create a two-way connection to the guest. The behaviour differs 3748 slightly between Windows hosts and other hosts: 3749 3750 On Windows, a single duplex pipe will be created at 3751 ``\\.pipe\path``. 3752 3753 On other hosts, 2 pipes will be created called ``path.in`` and 3754 ``path.out``. Data written to ``path.in`` will be received by the 3755 guest. Data written by the guest can be read from ``path.out``. QEMU 3756 will not create these fifos, and requires them to be present. 3757 3758 ``path`` forms part of the pipe path as described above. ``path`` is 3759 required. 3760 3761``-chardev console,id=id`` 3762 Send traffic from the guest to QEMU's standard output. ``console`` 3763 does not take any options. 3764 3765 ``console`` is only available on Windows hosts. 3766 3767``-chardev serial,id=id,path=path`` 3768 Send traffic from the guest to a serial device on the host. 3769 3770 On Unix hosts serial will actually accept any tty device, not only 3771 serial lines. 3772 3773 ``path`` specifies the name of the serial device to open. 3774 3775``-chardev pty,id=id`` 3776 Create a new pseudo-terminal on the host and connect to it. ``pty`` 3777 does not take any options. 3778 3779 ``pty`` is not available on Windows hosts. 3780 3781``-chardev stdio,id=id[,signal=on|off]`` 3782 Connect to standard input and standard output of the QEMU process. 3783 3784 ``signal`` controls if signals are enabled on the terminal, that 3785 includes exiting QEMU with the key sequence Control-c. This option 3786 is enabled by default, use ``signal=off`` to disable it. 3787 3788``-chardev braille,id=id`` 3789 Connect to a local BrlAPI server. ``braille`` does not take any 3790 options. 3791 3792``-chardev parallel,id=id,path=path`` 3793 \ 3794 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD 3795 hosts. 3796 3797 Connect to a local parallel port. 3798 3799 ``path`` specifies the path to the parallel port device. ``path`` is 3800 required. 3801 3802``-chardev spicevmc,id=id,debug=debug,name=name`` 3803 ``spicevmc`` is only available when spice support is built in. 3804 3805 ``debug`` debug level for spicevmc 3806 3807 ``name`` name of spice channel to connect to 3808 3809 Connect to a spice virtual machine channel, such as vdiport. 3810 3811``-chardev spiceport,id=id,debug=debug,name=name`` 3812 ``spiceport`` is only available when spice support is built in. 3813 3814 ``debug`` debug level for spicevmc 3815 3816 ``name`` name of spice port to connect to 3817 3818 Connect to a spice port, allowing a Spice client to handle the 3819 traffic identified by a name (preferably a fqdn). 3820ERST 3821 3822DEFHEADING() 3823 3824#ifdef CONFIG_TPM 3825DEFHEADING(TPM device options:) 3826 3827DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3828 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3829 " use path to provide path to a character device; default is /dev/tpm0\n" 3830 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3831 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3832 "-tpmdev emulator,id=id,chardev=dev\n" 3833 " configure the TPM device using chardev backend\n", 3834 QEMU_ARCH_ALL) 3835SRST 3836The general form of a TPM device option is: 3837 3838``-tpmdev backend,id=id[,options]`` 3839 The specific backend type will determine the applicable options. The 3840 ``-tpmdev`` option creates the TPM backend and requires a 3841 ``-device`` option that specifies the TPM frontend interface model. 3842 3843 Use ``-tpmdev help`` to print all available TPM backend types. 3844 3845The available backends are: 3846 3847``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path`` 3848 (Linux-host only) Enable access to the host's TPM using the 3849 passthrough driver. 3850 3851 ``path`` specifies the path to the host's TPM device, i.e., on a 3852 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by 3853 default ``/dev/tpm0`` is used. 3854 3855 ``cancel-path`` specifies the path to the host TPM device's sysfs 3856 entry allowing for cancellation of an ongoing TPM command. 3857 ``cancel-path`` is optional and by default QEMU will search for the 3858 sysfs entry to use. 3859 3860 Some notes about using the host's TPM with the passthrough driver: 3861 3862 The TPM device accessed by the passthrough driver must not be used 3863 by any other application on the host. 3864 3865 Since the host's firmware (BIOS/UEFI) has already initialized the 3866 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize 3867 the TPM again and may therefore not show a TPM-specific menu that 3868 would otherwise allow the user to configure the TPM, e.g., allow the 3869 user to enable/disable or activate/deactivate the TPM. Further, if 3870 TPM ownership is released from within a VM then the host's TPM will 3871 get disabled and deactivated. To enable and activate the TPM again 3872 afterwards, the host has to be rebooted and the user is required to 3873 enter the firmware's menu to enable and activate the TPM. If the TPM 3874 is left disabled and/or deactivated most TPM commands will fail. 3875 3876 To create a passthrough TPM use the following two options: 3877 3878 :: 3879 3880 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3881 3882 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by 3883 ``tpmdev=tpm0`` in the device option. 3884 3885``-tpmdev emulator,id=id,chardev=dev`` 3886 (Linux-host only) Enable access to a TPM emulator using Unix domain 3887 socket based chardev backend. 3888 3889 ``chardev`` specifies the unique ID of a character device backend 3890 that provides connection to the software TPM server. 3891 3892 To create a TPM emulator backend device with chardev socket backend: 3893 3894 :: 3895 3896 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3897ERST 3898 3899DEFHEADING() 3900 3901#endif 3902 3903DEFHEADING(Boot Image or Kernel specific:) 3904SRST 3905There are broadly 4 ways you can boot a system with QEMU. 3906 3907 - specify a firmware and let it control finding a kernel 3908 - specify a firmware and pass a hint to the kernel to boot 3909 - direct kernel image boot 3910 - manually load files into the guest's address space 3911 3912The third method is useful for quickly testing kernels but as there is 3913no firmware to pass configuration information to the kernel the 3914hardware must either be probeable, the kernel built for the exact 3915configuration or passed some configuration data (e.g. a DTB blob) 3916which tells the kernel what drivers it needs. This exact details are 3917often hardware specific. 3918 3919The final method is the most generic way of loading images into the 3920guest address space and used mostly for ``bare metal`` type 3921development where the reset vectors of the processor are taken into 3922account. 3923 3924ERST 3925 3926SRST 3927 3928For x86 machines and some other architectures ``-bios`` will generally 3929do the right thing with whatever it is given. For other machines the 3930more strict ``-pflash`` option needs an image that is sized for the 3931flash device for the given machine type. 3932 3933Please see the :ref:`system-targets-ref` section of the manual for 3934more detailed documentation. 3935 3936ERST 3937 3938DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3939 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3940SRST 3941``-bios file`` 3942 Set the filename for the BIOS. 3943ERST 3944 3945DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 3946 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 3947SRST 3948``-pflash file`` 3949 Use file as a parallel flash image. 3950ERST 3951 3952SRST 3953 3954The kernel options were designed to work with Linux kernels although 3955other things (like hypervisors) can be packaged up as a kernel 3956executable image. The exact format of a executable image is usually 3957architecture specific. 3958 3959The way in which the kernel is started (what address it is loaded at, 3960what if any information is passed to it via CPU registers, the state 3961of the hardware when it is started, and so on) is also architecture 3962specific. Typically it follows the specification laid down by the 3963Linux kernel for how kernels for that architecture must be started. 3964 3965ERST 3966 3967DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3968 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3969SRST 3970``-kernel bzImage`` 3971 Use bzImage as kernel image. The kernel can be either a Linux kernel 3972 or in multiboot format. 3973ERST 3974 3975DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3976 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3977SRST 3978``-append cmdline`` 3979 Use cmdline as kernel command line 3980ERST 3981 3982DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3983 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3984SRST 3985``-initrd file`` 3986 Use file as initial ram disk. 3987 3988``-initrd "file1 arg=foo,file2"`` 3989 This syntax is only available with multiboot. 3990 3991 Use file1 and file2 as modules and pass arg=foo as parameter to the 3992 first module. 3993ERST 3994 3995DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3996 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3997SRST 3998``-dtb file`` 3999 Use file as a device tree binary (dtb) image and pass it to the 4000 kernel on boot. 4001ERST 4002 4003SRST 4004 4005Finally you can also manually load images directly into the address 4006space of the guest. This is most useful for developers who already 4007know the layout of their guest and take care to ensure something sane 4008will happen when the reset vector executes. 4009 4010The generic loader can be invoked by using the loader device: 4011 4012``-device loader,addr=<addr>,data=<data>,data-len=<data-len>[,data-be=<data-be>][,cpu-num=<cpu-num>]`` 4013 4014there is also the guest loader which operates in a similar way but 4015tweaks the DTB so a hypervisor loaded via ``-kernel`` can find where 4016the guest image is: 4017 4018``-device guest-loader,addr=<addr>[,kernel=<path>,[bootargs=<arguments>]][,initrd=<path>]`` 4019 4020ERST 4021 4022DEFHEADING() 4023 4024DEFHEADING(Debug/Expert options:) 4025 4026DEF("compat", HAS_ARG, QEMU_OPTION_compat, 4027 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n" 4028 " Policy for handling deprecated management interfaces\n" 4029 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n" 4030 " Policy for handling unstable management interfaces\n", 4031 QEMU_ARCH_ALL) 4032SRST 4033``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]`` 4034 Set policy for handling deprecated management interfaces (experimental): 4035 4036 ``deprecated-input=accept`` (default) 4037 Accept deprecated commands and arguments 4038 ``deprecated-input=reject`` 4039 Reject deprecated commands and arguments 4040 ``deprecated-input=crash`` 4041 Crash on deprecated commands and arguments 4042 ``deprecated-output=accept`` (default) 4043 Emit deprecated command results and events 4044 ``deprecated-output=hide`` 4045 Suppress deprecated command results and events 4046 4047 Limitation: covers only syntactic aspects of QMP. 4048 4049``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]`` 4050 Set policy for handling unstable management interfaces (experimental): 4051 4052 ``unstable-input=accept`` (default) 4053 Accept unstable commands and arguments 4054 ``unstable-input=reject`` 4055 Reject unstable commands and arguments 4056 ``unstable-input=crash`` 4057 Crash on unstable commands and arguments 4058 ``unstable-output=accept`` (default) 4059 Emit unstable command results and events 4060 ``unstable-output=hide`` 4061 Suppress unstable command results and events 4062 4063 Limitation: covers only syntactic aspects of QMP. 4064ERST 4065 4066DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 4067 "-fw_cfg [name=]<name>,file=<file>\n" 4068 " add named fw_cfg entry with contents from file\n" 4069 "-fw_cfg [name=]<name>,string=<str>\n" 4070 " add named fw_cfg entry with contents from string\n", 4071 QEMU_ARCH_ALL) 4072SRST 4073``-fw_cfg [name=]name,file=file`` 4074 Add named fw\_cfg entry with contents from file file. 4075 4076``-fw_cfg [name=]name,string=str`` 4077 Add named fw\_cfg entry with contents from string str. 4078 4079 The terminating NUL character of the contents of str will not be 4080 included as part of the fw\_cfg item data. To insert contents with 4081 embedded NUL characters, you have to use the file parameter. 4082 4083 The fw\_cfg entries are passed by QEMU through to the guest. 4084 4085 Example: 4086 4087 :: 4088 4089 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 4090 4091 creates an fw\_cfg entry named opt/com.mycompany/blob with contents 4092 from ./my\_blob.bin. 4093ERST 4094 4095DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 4096 "-serial dev redirect the serial port to char device 'dev'\n", 4097 QEMU_ARCH_ALL) 4098SRST 4099``-serial dev`` 4100 Redirect the virtual serial port to host character device dev. The 4101 default device is ``vc`` in graphical mode and ``stdio`` in non 4102 graphical mode. 4103 4104 This option can be used several times to simulate up to 4 serial 4105 ports. 4106 4107 Use ``-serial none`` to disable all serial ports. 4108 4109 Available character devices are: 4110 4111 ``vc[:WxH]`` 4112 Virtual console. Optionally, a width and height can be given in 4113 pixel with 4114 4115 :: 4116 4117 vc:800x600 4118 4119 It is also possible to specify width or height in characters: 4120 4121 :: 4122 4123 vc:80Cx24C 4124 4125 ``pty`` 4126 [Linux only] Pseudo TTY (a new PTY is automatically allocated) 4127 4128 ``none`` 4129 No device is allocated. 4130 4131 ``null`` 4132 void device 4133 4134 ``chardev:id`` 4135 Use a named character device defined with the ``-chardev`` 4136 option. 4137 4138 ``/dev/XXX`` 4139 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial 4140 port parameters are set according to the emulated ones. 4141 4142 ``/dev/parportN`` 4143 [Linux only, parallel port only] Use host parallel port N. 4144 Currently SPP and EPP parallel port features can be used. 4145 4146 ``file:filename`` 4147 Write output to filename. No character can be read. 4148 4149 ``stdio`` 4150 [Unix only] standard input/output 4151 4152 ``pipe:filename`` 4153 name pipe filename 4154 4155 ``COMn`` 4156 [Windows only] Use host serial port n 4157 4158 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]`` 4159 This implements UDP Net Console. When remote\_host or src\_ip 4160 are not specified they default to ``0.0.0.0``. When not using a 4161 specified src\_port a random port is automatically chosen. 4162 4163 If you just want a simple readonly console you can use 4164 ``netcat`` or ``nc``, by starting QEMU with: 4165 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time 4166 QEMU writes something to that port it will appear in the 4167 netconsole session. 4168 4169 If you plan to send characters back via netconsole or you want 4170 to stop and start QEMU a lot of times, you should have QEMU use 4171 the same source port each time by using something like ``-serial 4172 udp::4555@:4556`` to QEMU. Another approach is to use a patched 4173 version of netcat which can listen to a TCP port and send and 4174 receive characters via udp. If you have a patched version of 4175 netcat which activates telnet remote echo and single char 4176 transfer, then you can use the following options to set up a 4177 netcat redirector to allow telnet on port 5555 to access the 4178 QEMU port. 4179 4180 ``QEMU Options:`` 4181 -serial udp::4555@:4556 4182 4183 ``netcat options:`` 4184 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 4185 4186 ``telnet options:`` 4187 localhost 5555 4188 4189 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]`` 4190 The TCP Net Console has two modes of operation. It can send the 4191 serial I/O to a location or wait for a connection from a 4192 location. By default the TCP Net Console is sent to host at the 4193 port. If you use the ``server=on`` option QEMU will wait for a client 4194 socket application to connect to the port before continuing, 4195 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off`` 4196 option disables the Nagle buffering algorithm. The ``reconnect=on`` 4197 option only applies if ``server=no`` is set, if the connection goes 4198 down it will attempt to reconnect at the given interval. If host 4199 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a 4200 time is accepted. You can use ``telnet=on`` to connect to the 4201 corresponding character device. 4202 4203 ``Example to send tcp console to 192.168.0.2 port 4444`` 4204 -serial tcp:192.168.0.2:4444 4205 4206 ``Example to listen and wait on port 4444 for connection`` 4207 -serial tcp::4444,server=on 4208 4209 ``Example to not wait and listen on ip 192.168.0.100 port 4444`` 4210 -serial tcp:192.168.0.100:4444,server=on,wait=off 4211 4212 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]`` 4213 The telnet protocol is used instead of raw tcp sockets. The 4214 options work the same as if you had specified ``-serial tcp``. 4215 The difference is that the port acts like a telnet server or 4216 client using telnet option negotiation. This will also allow you 4217 to send the MAGIC\_SYSRQ sequence if you use a telnet that 4218 supports sending the break sequence. Typically in unix telnet 4219 you do it with Control-] and then type "send break" followed by 4220 pressing the enter key. 4221 4222 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]`` 4223 The WebSocket protocol is used instead of raw tcp socket. The 4224 port acts as a WebSocket server. Client mode is not supported. 4225 4226 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]`` 4227 A unix domain socket is used instead of a tcp socket. The option 4228 works the same as if you had specified ``-serial tcp`` except 4229 the unix domain socket path is used for connections. 4230 4231 ``mon:dev_string`` 4232 This is a special option to allow the monitor to be multiplexed 4233 onto another serial port. The monitor is accessed with key 4234 sequence of Control-a and then pressing c. dev\_string should be 4235 any one of the serial devices specified above. An example to 4236 multiplex the monitor onto a telnet server listening on port 4237 4444 would be: 4238 4239 ``-serial mon:telnet::4444,server=on,wait=off`` 4240 4241 When the monitor is multiplexed to stdio in this way, Ctrl+C 4242 will not terminate QEMU any more but will be passed to the guest 4243 instead. 4244 4245 ``braille`` 4246 Braille device. This will use BrlAPI to display the braille 4247 output on a real or fake device. 4248 4249 ``msmouse`` 4250 Three button serial mouse. Configure the guest to use Microsoft 4251 protocol. 4252ERST 4253 4254DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 4255 "-parallel dev redirect the parallel port to char device 'dev'\n", 4256 QEMU_ARCH_ALL) 4257SRST 4258``-parallel dev`` 4259 Redirect the virtual parallel port to host device dev (same devices 4260 as the serial port). On Linux hosts, ``/dev/parportN`` can be used 4261 to use hardware devices connected on the corresponding host parallel 4262 port. 4263 4264 This option can be used several times to simulate up to 3 parallel 4265 ports. 4266 4267 Use ``-parallel none`` to disable all parallel ports. 4268ERST 4269 4270DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 4271 "-monitor dev redirect the monitor to char device 'dev'\n", 4272 QEMU_ARCH_ALL) 4273SRST 4274``-monitor dev`` 4275 Redirect the monitor to host device dev (same devices as the serial 4276 port). The default device is ``vc`` in graphical mode and ``stdio`` 4277 in non graphical mode. Use ``-monitor none`` to disable the default 4278 monitor. 4279ERST 4280DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 4281 "-qmp dev like -monitor but opens in 'control' mode\n", 4282 QEMU_ARCH_ALL) 4283SRST 4284``-qmp dev`` 4285 Like ``-monitor`` but opens in 'control' mode. For example, to make 4286 QMP available on localhost port 4444:: 4287 4288 -qmp tcp:localhost:4444,server=on,wait=off 4289 4290 Not all options are configurable via this syntax; for maximum 4291 flexibility use the ``-mon`` option and an accompanying ``-chardev``. 4292 4293ERST 4294DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 4295 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 4296 QEMU_ARCH_ALL) 4297SRST 4298``-qmp-pretty dev`` 4299 Like ``-qmp`` but uses pretty JSON formatting. 4300ERST 4301 4302DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 4303 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 4304SRST 4305``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]`` 4306 Set up a monitor connected to the chardev ``name``. 4307 QEMU supports two monitors: the Human Monitor Protocol 4308 (HMP; for human interaction), and the QEMU Monitor Protocol 4309 (QMP; a JSON RPC-style protocol). 4310 The default is HMP; ``mode=control`` selects QMP instead. 4311 ``pretty`` is only valid when ``mode=control``, 4312 turning on JSON pretty printing to ease 4313 human reading and debugging. 4314 4315 For example:: 4316 4317 -chardev socket,id=mon1,host=localhost,port=4444,server=on,wait=off \ 4318 -mon chardev=mon1,mode=control,pretty=on 4319 4320 enables the QMP monitor on localhost port 4444 with pretty-printing. 4321ERST 4322 4323DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 4324 "-debugcon dev redirect the debug console to char device 'dev'\n", 4325 QEMU_ARCH_ALL) 4326SRST 4327``-debugcon dev`` 4328 Redirect the debug console to host device dev (same devices as the 4329 serial port). The debug console is an I/O port which is typically 4330 port 0xe9; writing to that I/O port sends output to this device. The 4331 default device is ``vc`` in graphical mode and ``stdio`` in non 4332 graphical mode. 4333ERST 4334 4335DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 4336 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 4337SRST 4338``-pidfile file`` 4339 Store the QEMU process PID in file. It is useful if you launch QEMU 4340 from a script. 4341ERST 4342 4343DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 4344 "-singlestep deprecated synonym for -accel tcg,one-insn-per-tb=on\n", QEMU_ARCH_ALL) 4345SRST 4346``-singlestep`` 4347 This is a deprecated synonym for the TCG accelerator property 4348 ``one-insn-per-tb``. 4349ERST 4350 4351DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 4352 "--preconfig pause QEMU before machine is initialized (experimental)\n", 4353 QEMU_ARCH_ALL) 4354SRST 4355``--preconfig`` 4356 Pause QEMU for interactive configuration before the machine is 4357 created, which allows querying and configuring properties that will 4358 affect machine initialization. Use QMP command 'x-exit-preconfig' to 4359 exit the preconfig state and move to the next state (i.e. run guest 4360 if -S isn't used or pause the second time if -S is used). This 4361 option is experimental. 4362ERST 4363 4364DEF("S", 0, QEMU_OPTION_S, \ 4365 "-S freeze CPU at startup (use 'c' to start execution)\n", 4366 QEMU_ARCH_ALL) 4367SRST 4368``-S`` 4369 Do not start CPU at startup (you must type 'c' in the monitor). 4370ERST 4371 4372DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 4373 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 4374 " run qemu with overcommit hints\n" 4375 " mem-lock=on|off controls memory lock support (default: off)\n" 4376 " cpu-pm=on|off controls cpu power management (default: off)\n", 4377 QEMU_ARCH_ALL) 4378SRST 4379``-overcommit mem-lock=on|off`` 4380 \ 4381``-overcommit cpu-pm=on|off`` 4382 Run qemu with hints about host resource overcommit. The default is 4383 to assume that host overcommits all resources. 4384 4385 Locking qemu and guest memory can be enabled via ``mem-lock=on`` 4386 (disabled by default). This works when host memory is not 4387 overcommitted and reduces the worst-case latency for guest. 4388 4389 Guest ability to manage power state of host cpus (increasing latency 4390 for other processes on the same host cpu, but decreasing latency for 4391 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This 4392 works best when host CPU is not overcommitted. When used, host 4393 estimates of CPU cycle and power utilization will be incorrect, not 4394 taking into account guest idle time. 4395ERST 4396 4397DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 4398 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n" 4399 " the guest without waiting for gdb to connect; use -S too\n" 4400 " if you want it to not start execution.)\n", 4401 QEMU_ARCH_ALL) 4402SRST 4403``-gdb dev`` 4404 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter 4405 in the System Emulation Users Guide). Note that this option does not pause QEMU 4406 execution -- if you want QEMU to not start the guest until you 4407 connect with gdb and issue a ``continue`` command, you will need to 4408 also pass the ``-S`` option to QEMU. 4409 4410 The most usual configuration is to listen on a local TCP socket:: 4411 4412 -gdb tcp::3117 4413 4414 but you can specify other backends; UDP, pseudo TTY, or even stdio 4415 are all reasonable use cases. For example, a stdio connection 4416 allows you to start QEMU from within gdb and establish the 4417 connection via a pipe: 4418 4419 .. parsed-literal:: 4420 4421 (gdb) target remote | exec |qemu_system| -gdb stdio ... 4422ERST 4423 4424DEF("s", 0, QEMU_OPTION_s, \ 4425 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 4426 QEMU_ARCH_ALL) 4427SRST 4428``-s`` 4429 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 4430 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide). 4431ERST 4432 4433DEF("d", HAS_ARG, QEMU_OPTION_d, \ 4434 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 4435 QEMU_ARCH_ALL) 4436SRST 4437``-d item1[,...]`` 4438 Enable logging of specified items. Use '-d help' for a list of log 4439 items. 4440ERST 4441 4442DEF("D", HAS_ARG, QEMU_OPTION_D, \ 4443 "-D logfile output log to logfile (default stderr)\n", 4444 QEMU_ARCH_ALL) 4445SRST 4446``-D logfile`` 4447 Output log in logfile instead of to stderr 4448ERST 4449 4450DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 4451 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 4452 QEMU_ARCH_ALL) 4453SRST 4454``-dfilter range1[,...]`` 4455 Filter debug output to that relevant to a range of target addresses. 4456 The filter spec can be either start+size, start-size or start..end 4457 where start end and size are the addresses and sizes required. For 4458 example: 4459 4460 :: 4461 4462 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 4463 4464 Will dump output for any code in the 0x1000 sized block starting at 4465 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and 4466 another 0x1000 sized block starting at 0xffffffc00005f000. 4467ERST 4468 4469DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 4470 "-seed number seed the pseudo-random number generator\n", 4471 QEMU_ARCH_ALL) 4472SRST 4473``-seed number`` 4474 Force the guest to use a deterministic pseudo-random number 4475 generator, seeded with number. This does not affect crypto routines 4476 within the host. 4477ERST 4478 4479DEF("L", HAS_ARG, QEMU_OPTION_L, \ 4480 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 4481 QEMU_ARCH_ALL) 4482SRST 4483``-L path`` 4484 Set the directory for the BIOS, VGA BIOS and keymaps. 4485 4486 To list all the data directories, use ``-L help``. 4487ERST 4488 4489DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 4490 "-enable-kvm enable KVM full virtualization support\n", 4491 QEMU_ARCH_ARM | QEMU_ARCH_I386 | QEMU_ARCH_MIPS | QEMU_ARCH_PPC | 4492 QEMU_ARCH_RISCV | QEMU_ARCH_S390X) 4493SRST 4494``-enable-kvm`` 4495 Enable KVM full virtualization support. This option is only 4496 available if KVM support is enabled when compiling. 4497ERST 4498 4499DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 4500 "-xen-domid id specify xen guest domain id\n", 4501 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4502DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 4503 "-xen-attach attach to existing xen domain\n" 4504 " libxl will use this when starting QEMU\n", 4505 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4506DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 4507 "-xen-domid-restrict restrict set of available xen operations\n" 4508 " to specified domain id. (Does not affect\n" 4509 " xenpv machine type).\n", 4510 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4511SRST 4512``-xen-domid id`` 4513 Specify xen guest domain id (XEN only). 4514 4515``-xen-attach`` 4516 Attach to existing xen domain. libxl will use this when starting 4517 QEMU (XEN only). Restrict set of available xen operations to 4518 specified domain id (XEN only). 4519ERST 4520 4521DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 4522 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 4523SRST 4524``-no-reboot`` 4525 Exit instead of rebooting. 4526ERST 4527 4528DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 4529 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 4530SRST 4531``-no-shutdown`` 4532 Don't exit QEMU on guest shutdown, but instead only stop the 4533 emulation. This allows for instance switching to monitor to commit 4534 changes to the disk image. 4535ERST 4536 4537DEF("action", HAS_ARG, QEMU_OPTION_action, 4538 "-action reboot=reset|shutdown\n" 4539 " action when guest reboots [default=reset]\n" 4540 "-action shutdown=poweroff|pause\n" 4541 " action when guest shuts down [default=poweroff]\n" 4542 "-action panic=pause|shutdown|exit-failure|none\n" 4543 " action when guest panics [default=shutdown]\n" 4544 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" 4545 " action when watchdog fires [default=reset]\n", 4546 QEMU_ARCH_ALL) 4547SRST 4548``-action event=action`` 4549 The action parameter serves to modify QEMU's default behavior when 4550 certain guest events occur. It provides a generic method for specifying the 4551 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown`` 4552 parameters. 4553 4554 Examples: 4555 4556 ``-action panic=none`` 4557 ``-action reboot=shutdown,shutdown=pause`` 4558 ``-device i6300esb -action watchdog=pause`` 4559 4560ERST 4561 4562DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 4563 "-loadvm [tag|id]\n" \ 4564 " start right away with a saved state (loadvm in monitor)\n", 4565 QEMU_ARCH_ALL) 4566SRST 4567``-loadvm file`` 4568 Start right away with a saved state (``loadvm`` in monitor) 4569ERST 4570 4571#ifndef _WIN32 4572DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 4573 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 4574#endif 4575SRST 4576``-daemonize`` 4577 Daemonize the QEMU process after initialization. QEMU will not 4578 detach from standard IO until it is ready to receive connections on 4579 any of its devices. This option is a useful way for external 4580 programs to launch QEMU without having to cope with initialization 4581 race conditions. 4582ERST 4583 4584DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 4585 "-option-rom rom load a file, rom, into the option ROM space\n", 4586 QEMU_ARCH_ALL) 4587SRST 4588``-option-rom file`` 4589 Load the contents of file as an option ROM. This option is useful to 4590 load things like EtherBoot. 4591ERST 4592 4593DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 4594 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 4595 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 4596 QEMU_ARCH_ALL) 4597 4598SRST 4599``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]`` 4600 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at 4601 the current UTC or local time, respectively. ``localtime`` is 4602 required for correct date in MS-DOS or Windows. To start at a 4603 specific point in time, provide datetime in the format 4604 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC. 4605 4606 By default the RTC is driven by the host system time. This allows 4607 using of the RTC as accurate reference clock inside the guest, 4608 specifically if the host time is smoothly following an accurate 4609 external reference clock, e.g. via NTP. If you want to isolate the 4610 guest time from the host, you can set ``clock`` to ``rt`` instead, 4611 which provides a host monotonic clock if host support it. To even 4612 prevent the RTC from progressing during suspension, you can set 4613 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is 4614 recommended especially in icount mode in order to preserve 4615 determinism; however, note that in icount mode the speed of the 4616 virtual clock is variable and can in general differ from the host 4617 clock. 4618 4619 Enable ``driftfix`` (i386 targets only) if you experience time drift 4620 problems, specifically with Windows' ACPI HAL. This option will try 4621 to figure out how many timer interrupts were not processed by the 4622 Windows guest and will re-inject them. 4623ERST 4624 4625DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 4626 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \ 4627 " enable virtual instruction counter with 2^N clock ticks per\n" \ 4628 " instruction, enable aligning the host and virtual clocks\n" \ 4629 " or disable real time cpu sleeping, and optionally enable\n" \ 4630 " record-and-replay mode\n", QEMU_ARCH_ALL) 4631SRST 4632``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]`` 4633 Enable virtual instruction counter. The virtual cpu will execute one 4634 instruction every 2^N ns of virtual time. If ``auto`` is specified 4635 then the virtual cpu speed will be automatically adjusted to keep 4636 virtual time within a few seconds of real time. 4637 4638 Note that while this option can give deterministic behavior, it does 4639 not provide cycle accurate emulation. Modern CPUs contain 4640 superscalar out of order cores with complex cache hierarchies. The 4641 number of instructions executed often has little or no correlation 4642 with actual performance. 4643 4644 When the virtual cpu is sleeping, the virtual time will advance at 4645 default speed unless ``sleep=on`` is specified. With 4646 ``sleep=on``, the virtual time will jump to the next timer 4647 deadline instantly whenever the virtual cpu goes to sleep mode and 4648 will not advance if no timer is enabled. This behavior gives 4649 deterministic execution times from the guest point of view. 4650 The default if icount is enabled is ``sleep=off``. 4651 ``sleep=on`` cannot be used together with either ``shift=auto`` 4652 or ``align=on``. 4653 4654 ``align=on`` will activate the delay algorithm which will try to 4655 synchronise the host clock and the virtual clock. The goal is to 4656 have a guest running at the real frequency imposed by the shift 4657 option. Whenever the guest clock is behind the host clock and if 4658 ``align=on`` is specified then we print a message to the user to 4659 inform about the delay. Currently this option does not work when 4660 ``shift`` is ``auto``. Note: The sync algorithm will work for those 4661 shift values for which the guest clock runs ahead of the host clock. 4662 Typically this happens when the shift value is high (how high 4663 depends on the host machine). The default if icount is enabled 4664 is ``align=off``. 4665 4666 When the ``rr`` option is specified deterministic record/replay is 4667 enabled. The ``rrfile=`` option must also be provided to 4668 specify the path to the replay log. In record mode data is written 4669 to this file, and in replay mode it is read back. 4670 If the ``rrsnapshot`` option is given then it specifies a VM snapshot 4671 name. In record mode, a new VM snapshot with the given name is created 4672 at the start of execution recording. In replay mode this option 4673 specifies the snapshot name used to load the initial VM state. 4674ERST 4675 4676DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 4677 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 4678 " action when watchdog fires [default=reset]\n", 4679 QEMU_ARCH_ALL) 4680SRST 4681``-watchdog-action action`` 4682 The action controls what QEMU will do when the watchdog timer 4683 expires. The default is ``reset`` (forcefully reset the guest). 4684 Other possible actions are: ``shutdown`` (attempt to gracefully 4685 shutdown the guest), ``poweroff`` (forcefully poweroff the guest), 4686 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the 4687 guest), ``debug`` (print a debug message and continue), or ``none`` 4688 (do nothing). 4689 4690 Note that the ``shutdown`` action requires that the guest responds 4691 to ACPI signals, which it may not be able to do in the sort of 4692 situations where the watchdog would have expired, and thus 4693 ``-watchdog-action shutdown`` is not recommended for production use. 4694 4695 Examples: 4696 4697 ``-device i6300esb -watchdog-action pause`` 4698 4699ERST 4700 4701DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 4702 "-echr chr set terminal escape character instead of ctrl-a\n", 4703 QEMU_ARCH_ALL) 4704SRST 4705``-echr numeric_ascii_value`` 4706 Change the escape character used for switching to the monitor when 4707 using monitor and serial sharing. The default is ``0x01`` when using 4708 the ``-nographic`` option. ``0x01`` is equal to pressing 4709 ``Control-a``. You can select a different character from the ascii 4710 control keys where 1 through 26 map to Control-a through Control-z. 4711 For instance you could use the either of the following to change the 4712 escape character to Control-t. 4713 4714 ``-echr 0x14``; \ ``-echr 20`` 4715 4716ERST 4717 4718DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4719 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \ 4720 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \ 4721 "-incoming unix:socketpath\n" \ 4722 " prepare for incoming migration, listen on\n" \ 4723 " specified protocol and socket address\n" \ 4724 "-incoming fd:fd\n" \ 4725 "-incoming file:filename[,offset=offset]\n" \ 4726 "-incoming exec:cmdline\n" \ 4727 " accept incoming migration on given file descriptor\n" \ 4728 " or from given external command\n" \ 4729 "-incoming defer\n" \ 4730 " wait for the URI to be specified via migrate_incoming\n", 4731 QEMU_ARCH_ALL) 4732SRST 4733``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]`` 4734 \ 4735``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]`` 4736 Prepare for incoming migration, listen on a given tcp port. 4737 4738``-incoming unix:socketpath`` 4739 Prepare for incoming migration, listen on a given unix socket. 4740 4741``-incoming fd:fd`` 4742 Accept incoming migration from a given file descriptor. 4743 4744``-incoming file:filename[,offset=offset]`` 4745 Accept incoming migration from a given file starting at offset. 4746 offset allows the common size suffixes, or a 0x prefix, but not both. 4747 4748``-incoming exec:cmdline`` 4749 Accept incoming migration as an output from specified external 4750 command. 4751 4752``-incoming defer`` 4753 Wait for the URI to be specified via migrate\_incoming. The monitor 4754 can be used to change settings (such as migration parameters) prior 4755 to issuing the migrate\_incoming to allow the migration to begin. 4756ERST 4757 4758DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4759 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4760SRST 4761``-only-migratable`` 4762 Only allow migratable devices. Devices will not be allowed to enter 4763 an unmigratable state. 4764ERST 4765 4766DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4767 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4768SRST 4769``-nodefaults`` 4770 Don't create default devices. Normally, QEMU sets the default 4771 devices like serial port, parallel port, virtual console, monitor 4772 device, VGA adapter, floppy and CD-ROM drive and others. The 4773 ``-nodefaults`` option will disable all those default devices. 4774ERST 4775 4776#ifndef _WIN32 4777DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4778 "-chroot dir chroot to dir just before starting the VM (deprecated)\n", 4779 QEMU_ARCH_ALL) 4780#endif 4781SRST 4782``-chroot dir`` 4783 Deprecated, use '-run-with chroot=...' instead. 4784 Immediately before starting guest execution, chroot to the specified 4785 directory. Especially useful in combination with -runas. 4786ERST 4787 4788#ifndef _WIN32 4789DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4790 "-runas user change to user id user just before starting the VM\n" \ 4791 " user can be numeric uid:gid instead\n", 4792 QEMU_ARCH_ALL) 4793#endif 4794SRST 4795``-runas user`` 4796 Immediately before starting guest execution, drop root privileges, 4797 switching to the specified user. 4798ERST 4799 4800DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4801 "-prom-env variable=value\n" 4802 " set OpenBIOS nvram variables\n", 4803 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4804SRST 4805``-prom-env variable=value`` 4806 Set OpenBIOS nvram variable to given value (PPC, SPARC only). 4807 4808 :: 4809 4810 qemu-system-sparc -prom-env 'auto-boot?=false' \ 4811 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' 4812 4813 :: 4814 4815 qemu-system-ppc -prom-env 'auto-boot?=false' \ 4816 -prom-env 'boot-device=hd:2,\yaboot' \ 4817 -prom-env 'boot-args=conf=hd:2,\yaboot.conf' 4818ERST 4819DEF("semihosting", 0, QEMU_OPTION_semihosting, 4820 "-semihosting semihosting mode\n", 4821 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4822 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4823SRST 4824``-semihosting`` 4825 Enable :ref:`Semihosting` mode (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V only). 4826 4827 .. warning:: 4828 Note that this allows guest direct access to the host filesystem, so 4829 should only be used with a trusted guest OS. 4830 4831 See the -semihosting-config option documentation for further 4832 information about the facilities this enables. 4833ERST 4834DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4835 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]\n" \ 4836 " semihosting configuration\n", 4837QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4838QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4839SRST 4840``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]`` 4841 Enable and configure :ref:`Semihosting` (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V 4842 only). 4843 4844 .. warning:: 4845 Note that this allows guest direct access to the host filesystem, so 4846 should only be used with a trusted guest OS. 4847 4848 ``target=native|gdb|auto`` 4849 Defines where the semihosting calls will be addressed, to QEMU 4850 (``native``) or to GDB (``gdb``). The default is ``auto``, which 4851 means ``gdb`` during debug sessions and ``native`` otherwise. 4852 4853 ``chardev=str1`` 4854 Send the output to a chardev backend output for native or auto 4855 output when not in gdb 4856 4857 ``userspace=on|off`` 4858 Allows code running in guest userspace to access the semihosting 4859 interface. The default is that only privileged guest code can 4860 make semihosting calls. Note that setting ``userspace=on`` should 4861 only be used if all guest code is trusted (for example, in 4862 bare-metal test case code). 4863 4864 ``arg=str1,arg=str2,...`` 4865 Allows the user to pass input arguments, and can be used 4866 multiple times to build up a list. The old-style 4867 ``-kernel``/``-append`` method of passing a command line is 4868 still supported for backward compatibility. If both the 4869 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are 4870 specified, the former is passed to semihosting as it always 4871 takes precedence. 4872ERST 4873DEF("old-param", 0, QEMU_OPTION_old_param, 4874 "-old-param old param mode\n", QEMU_ARCH_ARM) 4875SRST 4876``-old-param`` 4877 Old param mode (ARM only). 4878ERST 4879 4880DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4881 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4882 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4883 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4884 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4885 " by the kernel, but typically no longer used by modern\n" \ 4886 " C library implementations.\n" \ 4887 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \ 4888 " to elevate privileges using set*uid|gid system calls.\n" \ 4889 " The value 'children' will deny set*uid|gid system calls for\n" \ 4890 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4891 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4892 " blocking *fork and execve\n" \ 4893 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4894 QEMU_ARCH_ALL) 4895SRST 4896``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]`` 4897 Enable Seccomp mode 2 system call filter. 'on' will enable syscall 4898 filtering and 'off' will disable it. The default is 'off'. 4899 4900 ``obsolete=string`` 4901 Enable Obsolete system calls 4902 4903 ``elevateprivileges=string`` 4904 Disable set\*uid\|gid system calls 4905 4906 ``spawn=string`` 4907 Disable \*fork and execve 4908 4909 ``resourcecontrol=string`` 4910 Disable process affinity and schedular priority 4911ERST 4912 4913DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4914 "-readconfig <file>\n" 4915 " read config file\n", QEMU_ARCH_ALL) 4916SRST 4917``-readconfig file`` 4918 Read device configuration from file. This approach is useful when 4919 you want to spawn QEMU process with many command line options but 4920 you don't want to exceed the command line character limit. 4921ERST 4922 4923DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4924 "-no-user-config\n" 4925 " do not load default user-provided config files at startup\n", 4926 QEMU_ARCH_ALL) 4927SRST 4928``-no-user-config`` 4929 The ``-no-user-config`` option makes QEMU not load any of the 4930 user-provided config files on sysconfdir. 4931ERST 4932 4933DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4934 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4935 " specify tracing options\n", 4936 QEMU_ARCH_ALL) 4937SRST 4938``-trace [[enable=]pattern][,events=file][,file=file]`` 4939 .. include:: ../qemu-option-trace.rst.inc 4940 4941ERST 4942DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4943 "-plugin [file=]<file>[,<argname>=<argvalue>]\n" 4944 " load a plugin\n", 4945 QEMU_ARCH_ALL) 4946SRST 4947``-plugin file=file[,argname=argvalue]`` 4948 Load a plugin. 4949 4950 ``file=file`` 4951 Load the given plugin from a shared library file. 4952 4953 ``argname=argvalue`` 4954 Argument passed to the plugin. (Can be given multiple times.) 4955ERST 4956 4957HXCOMM Internal use 4958DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4959DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4960 4961#ifdef __linux__ 4962DEF("async-teardown", 0, QEMU_OPTION_asyncteardown, 4963 "-async-teardown enable asynchronous teardown\n", 4964 QEMU_ARCH_ALL) 4965SRST 4966``-async-teardown`` 4967 This option is deprecated and should no longer be used. The new option 4968 ``-run-with async-teardown=on`` is a replacement. 4969ERST 4970#endif 4971#ifdef CONFIG_POSIX 4972DEF("run-with", HAS_ARG, QEMU_OPTION_run_with, 4973 "-run-with [async-teardown=on|off][,chroot=dir]\n" 4974 " Set miscellaneous QEMU process lifecycle options:\n" 4975 " async-teardown=on enables asynchronous teardown (Linux only)\n" 4976 " chroot=dir chroot to dir just before starting the VM\n", 4977 QEMU_ARCH_ALL) 4978SRST 4979``-run-with [async-teardown=on|off][,chroot=dir]`` 4980 Set QEMU process lifecycle options. 4981 4982 ``async-teardown=on`` enables asynchronous teardown. A new process called 4983 "cleanup/<QEMU_PID>" will be created at startup sharing the address 4984 space with the main QEMU process, using clone. It will wait for the 4985 main QEMU process to terminate completely, and then exit. This allows 4986 QEMU to terminate very quickly even if the guest was huge, leaving the 4987 teardown of the address space to the cleanup process. Since the cleanup 4988 process shares the same cgroups as the main QEMU process, accounting is 4989 performed correctly. This only works if the cleanup process is not 4990 forcefully killed with SIGKILL before the main QEMU process has 4991 terminated completely. 4992 4993 ``chroot=dir`` can be used for doing a chroot to the specified directory 4994 immediately before starting the guest execution. This is especially useful 4995 in combination with -runas. 4996ERST 4997#endif 4998 4999DEF("msg", HAS_ARG, QEMU_OPTION_msg, 5000 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n" 5001 " control error message format\n" 5002 " timestamp=on enables timestamps (default: off)\n" 5003 " guest-name=on enables guest name prefix but only if\n" 5004 " -name guest option is set (default: off)\n", 5005 QEMU_ARCH_ALL) 5006SRST 5007``-msg [timestamp[=on|off]][,guest-name[=on|off]]`` 5008 Control error message format. 5009 5010 ``timestamp=on|off`` 5011 Prefix messages with a timestamp. Default is off. 5012 5013 ``guest-name=on|off`` 5014 Prefix messages with guest name but only if -name guest option is set 5015 otherwise the option is ignored. Default is off. 5016ERST 5017 5018DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 5019 "-dump-vmstate <file>\n" 5020 " Output vmstate information in JSON format to file.\n" 5021 " Use the scripts/vmstate-static-checker.py file to\n" 5022 " check for possible regressions in migration code\n" 5023 " by comparing two such vmstate dumps.\n", 5024 QEMU_ARCH_ALL) 5025SRST 5026``-dump-vmstate file`` 5027 Dump json-encoded vmstate information for current machine type to 5028 file in file 5029ERST 5030 5031DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 5032 "-enable-sync-profile\n" 5033 " enable synchronization profiling\n", 5034 QEMU_ARCH_ALL) 5035SRST 5036``-enable-sync-profile`` 5037 Enable synchronization profiling. 5038ERST 5039 5040#if defined(CONFIG_TCG) && defined(CONFIG_LINUX) 5041DEF("perfmap", 0, QEMU_OPTION_perfmap, 5042 "-perfmap generate a /tmp/perf-${pid}.map file for perf\n", 5043 QEMU_ARCH_ALL) 5044SRST 5045``-perfmap`` 5046 Generate a map file for Linux perf tools that will allow basic profiling 5047 information to be broken down into basic blocks. 5048ERST 5049 5050DEF("jitdump", 0, QEMU_OPTION_jitdump, 5051 "-jitdump generate a jit-${pid}.dump file for perf\n", 5052 QEMU_ARCH_ALL) 5053SRST 5054``-jitdump`` 5055 Generate a dump file for Linux perf tools that maps basic blocks to symbol 5056 names, line numbers and JITted code. 5057ERST 5058#endif 5059 5060DEFHEADING() 5061 5062DEFHEADING(Generic object creation:) 5063 5064DEF("object", HAS_ARG, QEMU_OPTION_object, 5065 "-object TYPENAME[,PROP1=VALUE1,...]\n" 5066 " create a new object of type TYPENAME setting properties\n" 5067 " in the order they are specified. Note that the 'id'\n" 5068 " property must be set. These objects are placed in the\n" 5069 " '/objects' path.\n", 5070 QEMU_ARCH_ALL) 5071SRST 5072``-object typename[,prop1=value1,...]`` 5073 Create a new object of type typename setting properties in the order 5074 they are specified. Note that the 'id' property must be set. These 5075 objects are placed in the '/objects' path. 5076 5077 ``-object memory-backend-file,id=id,size=size,mem-path=dir,share=on|off,discard-data=on|off,merge=on|off,dump=on|off,prealloc=on|off,host-nodes=host-nodes,policy=default|preferred|bind|interleave,align=align,offset=offset,readonly=on|off,rom=on|off|auto`` 5078 Creates a memory file backend object, which can be used to back 5079 the guest RAM with huge pages. 5080 5081 The ``id`` parameter is a unique ID that will be used to 5082 reference this memory region in other parameters, e.g. ``-numa``, 5083 ``-device nvdimm``, etc. 5084 5085 The ``size`` option provides the size of the memory region, and 5086 accepts common suffixes, e.g. ``500M``. 5087 5088 The ``mem-path`` provides the path to either a shared memory or 5089 huge page filesystem mount. 5090 5091 The ``share`` boolean option determines whether the memory 5092 region is marked as private to QEMU, or shared. The latter 5093 allows a co-operating external process to access the QEMU memory 5094 region. 5095 5096 The ``share`` is also required for pvrdma devices due to 5097 limitations in the RDMA API provided by Linux. 5098 5099 Setting share=on might affect the ability to configure NUMA 5100 bindings for the memory backend under some circumstances, see 5101 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel 5102 source tree for additional details. 5103 5104 Setting the ``discard-data`` boolean option to on indicates that 5105 file contents can be destroyed when QEMU exits, to avoid 5106 unnecessarily flushing data to the backing file. Note that 5107 ``discard-data`` is only an optimization, and QEMU might not 5108 discard file contents if it aborts unexpectedly or is terminated 5109 using SIGKILL. 5110 5111 The ``merge`` boolean option enables memory merge, also known as 5112 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider 5113 the pages for memory deduplication. 5114 5115 Setting the ``dump`` boolean option to off excludes the memory 5116 from core dumps. This feature is also known as MADV\_DONTDUMP. 5117 5118 The ``prealloc`` boolean option enables memory preallocation. 5119 5120 The ``host-nodes`` option binds the memory range to a list of 5121 NUMA host nodes. 5122 5123 The ``policy`` option sets the NUMA policy to one of the 5124 following values: 5125 5126 ``default`` 5127 default host policy 5128 5129 ``preferred`` 5130 prefer the given host node list for allocation 5131 5132 ``bind`` 5133 restrict memory allocation to the given host node list 5134 5135 ``interleave`` 5136 interleave memory allocations across the given host node 5137 list 5138 5139 The ``align`` option specifies the base address alignment when 5140 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg 5141 ``2M``. Some backend store specified by ``mem-path`` requires an 5142 alignment different than the default one used by QEMU, eg the 5143 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 5144 such cases, users can specify the required alignment via this 5145 option. 5146 5147 The ``offset`` option specifies the offset into the target file 5148 that the region starts at. You can use this parameter to back 5149 multiple regions with a single file. 5150 5151 The ``pmem`` option specifies whether the backing file specified 5152 by ``mem-path`` is in host persistent memory that can be 5153 accessed using the SNIA NVM programming model (e.g. Intel 5154 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary 5155 operations to guarantee the persistence of its own writes to 5156 ``mem-path`` (e.g. in vNVDIMM label emulation and live 5157 migration). Also, we will map the backend-file with MAP\_SYNC 5158 flag, which ensures the file metadata is in sync for 5159 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC 5160 requires support from both the host kernel (since Linux kernel 5161 4.15) and the filesystem of ``mem-path`` mounted with DAX 5162 option. 5163 5164 The ``readonly`` option specifies whether the backing file is opened 5165 read-only or read-write (default). 5166 5167 The ``rom`` option specifies whether to create Read Only Memory 5168 (ROM) that cannot be modified by the VM. Any write attempts to such 5169 ROM will be denied. Most use cases want proper RAM instead of ROM. 5170 However, selected use cases, like R/O NVDIMMs, can benefit from 5171 ROM. If set to ``on``, create ROM; if set to ``off``, create 5172 writable RAM; if set to ``auto`` (default), the value of the 5173 ``readonly`` option is used. This option is primarily helpful when 5174 we want to have writable RAM in configurations that would 5175 traditionally create ROM before the ``rom`` option was introduced: 5176 VM templating, where we want to open a file readonly 5177 (``readonly=on``) and mark the memory to be private for QEMU 5178 (``share=off``). For this use case, we need writable RAM instead 5179 of ROM, and want to also set ``rom=off``. 5180 5181 ``-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`` 5182 Creates a memory backend object, which can be used to back the 5183 guest RAM. Memory backend objects offer more control than the 5184 ``-m`` option that is traditionally used to define guest RAM. 5185 Please refer to ``memory-backend-file`` for a description of the 5186 options. 5187 5188 ``-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`` 5189 Creates an anonymous memory file backend object, which allows 5190 QEMU to share the memory with an external process (e.g. when 5191 using vhost-user). The memory is allocated with memfd and 5192 optional sealing. (Linux only) 5193 5194 The ``seal`` option creates a sealed-file, that will block 5195 further resizing the memory ('on' by default). 5196 5197 The ``hugetlb`` option specify the file to be created resides in 5198 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction 5199 with the ``hugetlb`` option, the ``hugetlbsize`` option specify 5200 the hugetlb page size on systems that support multiple hugetlb 5201 page sizes (it must be a power of 2 value supported by the 5202 system). 5203 5204 In some versions of Linux, the ``hugetlb`` option is 5205 incompatible with the ``seal`` option (requires at least Linux 5206 4.16). 5207 5208 Please refer to ``memory-backend-file`` for a description of the 5209 other options. 5210 5211 The ``share`` boolean option is on by default with memfd. 5212 5213 ``-object rng-builtin,id=id`` 5214 Creates a random number generator backend which obtains entropy 5215 from QEMU builtin functions. The ``id`` parameter is a unique ID 5216 that will be used to reference this entropy backend from the 5217 ``virtio-rng`` device. By default, the ``virtio-rng`` device 5218 uses this RNG backend. 5219 5220 ``-object rng-random,id=id,filename=/dev/random`` 5221 Creates a random number generator backend which obtains entropy 5222 from a device on the host. The ``id`` parameter is a unique ID 5223 that will be used to reference this entropy backend from the 5224 ``virtio-rng`` device. The ``filename`` parameter specifies 5225 which file to obtain entropy from and if omitted defaults to 5226 ``/dev/urandom``. 5227 5228 ``-object rng-egd,id=id,chardev=chardevid`` 5229 Creates a random number generator backend which obtains entropy 5230 from an external daemon running on the host. The ``id`` 5231 parameter is a unique ID that will be used to reference this 5232 entropy backend from the ``virtio-rng`` device. The ``chardev`` 5233 parameter is the unique ID of a character device backend that 5234 provides the connection to the RNG daemon. 5235 5236 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off`` 5237 Creates a TLS anonymous credentials object, which can be used to 5238 provide TLS support on network backends. The ``id`` parameter is 5239 a unique ID which network backends will use to access the 5240 credentials. The ``endpoint`` is either ``server`` or ``client`` 5241 depending on whether the QEMU network backend that uses the 5242 credentials will be acting as a client or as a server. If 5243 ``verify-peer`` is enabled (the default) then once the handshake 5244 is completed, the peer credentials will be verified, though this 5245 is a no-op for anonymous credentials. 5246 5247 The dir parameter tells QEMU where to find the credential files. 5248 For server endpoints, this directory may contain a file 5249 dh-params.pem providing diffie-hellman parameters to use for the 5250 TLS server. If the file is missing, QEMU will generate a set of 5251 DH parameters at startup. This is a computationally expensive 5252 operation that consumes random pool entropy, so it is 5253 recommended that a persistent set of parameters be generated 5254 upfront and saved. 5255 5256 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]`` 5257 Creates a TLS Pre-Shared Keys (PSK) credentials object, which 5258 can be used to provide TLS support on network backends. The 5259 ``id`` parameter is a unique ID which network backends will use 5260 to access the credentials. The ``endpoint`` is either ``server`` 5261 or ``client`` depending on whether the QEMU network backend that 5262 uses the credentials will be acting as a client or as a server. 5263 For clients only, ``username`` is the username which will be 5264 sent to the server. If omitted it defaults to "qemu". 5265 5266 The dir parameter tells QEMU where to find the keys file. It is 5267 called "dir/keys.psk" and contains "username:key" pairs. This 5268 file can most easily be created using the GnuTLS ``psktool`` 5269 program. 5270 5271 For server endpoints, dir may also contain a file dh-params.pem 5272 providing diffie-hellman parameters to use for the TLS server. 5273 If the file is missing, QEMU will generate a set of DH 5274 parameters at startup. This is a computationally expensive 5275 operation that consumes random pool entropy, so it is 5276 recommended that a persistent set of parameters be generated up 5277 front and saved. 5278 5279 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id`` 5280 Creates a TLS anonymous credentials object, which can be used to 5281 provide TLS support on network backends. The ``id`` parameter is 5282 a unique ID which network backends will use to access the 5283 credentials. The ``endpoint`` is either ``server`` or ``client`` 5284 depending on whether the QEMU network backend that uses the 5285 credentials will be acting as a client or as a server. If 5286 ``verify-peer`` is enabled (the default) then once the handshake 5287 is completed, the peer credentials will be verified. With x509 5288 certificates, this implies that the clients must be provided 5289 with valid client certificates too. 5290 5291 The dir parameter tells QEMU where to find the credential files. 5292 For server endpoints, this directory may contain a file 5293 dh-params.pem providing diffie-hellman parameters to use for the 5294 TLS server. If the file is missing, QEMU will generate a set of 5295 DH parameters at startup. This is a computationally expensive 5296 operation that consumes random pool entropy, so it is 5297 recommended that a persistent set of parameters be generated 5298 upfront and saved. 5299 5300 For x509 certificate credentials the directory will contain 5301 further files providing the x509 certificates. The certificates 5302 must be stored in PEM format, in filenames ca-cert.pem, 5303 ca-crl.pem (optional), server-cert.pem (only servers), 5304 server-key.pem (only servers), client-cert.pem (only clients), 5305 and client-key.pem (only clients). 5306 5307 For the server-key.pem and client-key.pem files which contain 5308 sensitive private keys, it is possible to use an encrypted 5309 version by providing the passwordid parameter. This provides the 5310 ID of a previously created ``secret`` object containing the 5311 password for decryption. 5312 5313 The priority parameter allows to override the global default 5314 priority used by gnutls. This can be useful if the system 5315 administrator needs to use a weaker set of crypto priorities for 5316 QEMU without potentially forcing the weakness onto all 5317 applications. Or conversely if one wants wants a stronger 5318 default for QEMU than for all other applications, they can do 5319 this through this parameter. Its format is a gnutls priority 5320 string as described at 5321 https://gnutls.org/manual/html_node/Priority-Strings.html. 5322 5323 ``-object tls-cipher-suites,id=id,priority=priority`` 5324 Creates a TLS cipher suites object, which can be used to control 5325 the TLS cipher/protocol algorithms that applications are permitted 5326 to use. 5327 5328 The ``id`` parameter is a unique ID which frontends will use to 5329 access the ordered list of permitted TLS cipher suites from the 5330 host. 5331 5332 The ``priority`` parameter allows to override the global default 5333 priority used by gnutls. This can be useful if the system 5334 administrator needs to use a weaker set of crypto priorities for 5335 QEMU without potentially forcing the weakness onto all 5336 applications. Or conversely if one wants wants a stronger 5337 default for QEMU than for all other applications, they can do 5338 this through this parameter. Its format is a gnutls priority 5339 string as described at 5340 https://gnutls.org/manual/html_node/Priority-Strings.html. 5341 5342 An example of use of this object is to control UEFI HTTPS Boot. 5343 The tls-cipher-suites object exposes the ordered list of permitted 5344 TLS cipher suites from the host side to the guest firmware, via 5345 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER 5346 objects. The firmware uses the IANA_TLS_CIPHER array for configuring 5347 guest-side TLS. 5348 5349 In the following example, the priority at which the host-side policy 5350 is retrieved is given by the ``priority`` property. 5351 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to 5352 refer to /etc/crypto-policies/back-ends/gnutls.config. 5353 5354 .. parsed-literal:: 5355 5356 # |qemu_system| \\ 5357 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\ 5358 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 5359 5360 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` 5361 Interval t can't be 0, this filter batches the packet delivery: 5362 all packets arriving in a given interval on netdev netdevid are 5363 delayed until the end of the interval. Interval is in 5364 microseconds. ``status`` is optional that indicate whether the 5365 netfilter is on (enabled) or off (disabled), the default status 5366 for netfilter will be 'on'. 5367 5368 queue all\|rx\|tx is an option that can be applied to any 5369 netfilter. 5370 5371 ``all``: the filter is attached both to the receive and the 5372 transmit queue of the netdev (default). 5373 5374 ``rx``: the filter is attached to the receive queue of the 5375 netdev, where it will receive packets sent to the netdev. 5376 5377 ``tx``: the filter is attached to the transmit queue of the 5378 netdev, where it will receive packets sent by the netdev. 5379 5380 position head\|tail\|id=<id> is an option to specify where the 5381 filter should be inserted in the filter list. It can be applied 5382 to any netfilter. 5383 5384 ``head``: the filter is inserted at the head of the filter list, 5385 before any existing filters. 5386 5387 ``tail``: the filter is inserted at the tail of the filter list, 5388 behind any existing filters (default). 5389 5390 ``id=<id>``: the filter is inserted before or behind the filter 5391 specified by <id>, see the insert option below. 5392 5393 insert behind\|before is an option to specify where to insert 5394 the new filter relative to the one specified with 5395 position=id=<id>. It can be applied to any netfilter. 5396 5397 ``before``: insert before the specified filter. 5398 5399 ``behind``: insert behind the specified filter (default). 5400 5401 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5402 filter-mirror on netdev netdevid,mirror net packet to 5403 chardevchardevid, if it has the vnet\_hdr\_support flag, 5404 filter-mirror will mirror packet with vnet\_hdr\_len. 5405 5406 ``-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]`` 5407 filter-redirector on netdev netdevid,redirect filter's net 5408 packet to chardev chardevid,and redirect indev's packet to 5409 filter.if it has the vnet\_hdr\_support flag, filter-redirector 5410 will redirect packet with vnet\_hdr\_len. Create a 5411 filter-redirector we need to differ outdev id from indev id, id 5412 can not be the same. we can just use indev or outdev, but at 5413 least one of indev or outdev need to be specified. 5414 5415 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5416 Filter-rewriter is a part of COLO project.It will rewrite tcp 5417 packet to secondary from primary to keep secondary tcp 5418 connection,and rewrite tcp packet to primary from secondary make 5419 tcp packet can be handled by client.if it has the 5420 vnet\_hdr\_support flag, we can parse packet with vnet header. 5421 5422 usage: colo secondary: -object 5423 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object 5424 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object 5425 filter-rewriter,id=rew0,netdev=hn0,queue=all 5426 5427 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]`` 5428 Dump the network traffic on netdev dev to the file specified by 5429 filename. At most len bytes (64k by default) per packet are 5430 stored. The file format is libpcap, so it can be analyzed with 5431 tools such as tcpdump or Wireshark. 5432 5433 ``-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}]`` 5434 Colo-compare gets packet from primary\_in chardevid and 5435 secondary\_in, then compare whether the payload of primary packet 5436 and secondary packet are the same. If same, it will output 5437 primary packet to out\_dev, else it will notify COLO-framework to do 5438 checkpoint and send primary packet to out\_dev. In order to 5439 improve efficiency, we need to put the task of comparison in 5440 another iothread. If it has the vnet\_hdr\_support flag, 5441 colo compare will send/recv packet with vnet\_hdr\_len. 5442 The compare\_timeout=@var{ms} determines the maximum time of the 5443 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms} 5444 is to set the period of scanning expired primary node network packets. 5445 The max\_queue\_size=@var{size} is to set the max compare queue 5446 size depend on user environment. 5447 If user want to use Xen COLO, need to add the notify\_dev to 5448 notify Xen colo-frame to do checkpoint. 5449 5450 COLO-compare must be used with the help of filter-mirror, 5451 filter-redirector and filter-rewriter. 5452 5453 :: 5454 5455 KVM COLO 5456 5457 primary: 5458 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5459 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5460 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5461 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5462 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5463 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5464 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5465 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5466 -object iothread,id=iothread1 5467 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5468 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5469 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5470 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 5471 5472 secondary: 5473 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5474 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5475 -chardev socket,id=red0,host=3.3.3.3,port=9003 5476 -chardev socket,id=red1,host=3.3.3.3,port=9004 5477 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5478 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5479 5480 5481 Xen COLO 5482 5483 primary: 5484 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5485 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5486 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5487 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5488 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5489 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5490 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5491 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5492 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off 5493 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5494 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5495 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5496 -object iothread,id=iothread1 5497 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 5498 5499 secondary: 5500 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5501 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5502 -chardev socket,id=red0,host=3.3.3.3,port=9003 5503 -chardev socket,id=red1,host=3.3.3.3,port=9004 5504 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5505 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5506 5507 If you want to know the detail of above command line, you can 5508 read the colo-compare git log. 5509 5510 ``-object cryptodev-backend-builtin,id=id[,queues=queues]`` 5511 Creates a cryptodev backend which executes crypto operations from 5512 the QEMU cipher APIs. The id parameter is a unique ID that will 5513 be used to reference this cryptodev backend from the 5514 ``virtio-crypto`` device. The queues parameter is optional, 5515 which specify the queue number of cryptodev backend, the default 5516 of queues is 1. 5517 5518 .. parsed-literal:: 5519 5520 # |qemu_system| \\ 5521 [...] \\ 5522 -object cryptodev-backend-builtin,id=cryptodev0 \\ 5523 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5524 [...] 5525 5526 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]`` 5527 Creates a vhost-user cryptodev backend, backed by a chardev 5528 chardevid. The id parameter is a unique ID that will be used to 5529 reference this cryptodev backend from the ``virtio-crypto`` 5530 device. The chardev should be a unix domain socket backed one. 5531 The vhost-user uses a specifically defined protocol to pass 5532 vhost ioctl replacement messages to an application on the other 5533 end of the socket. The queues parameter is optional, which 5534 specify the queue number of cryptodev backend for multiqueue 5535 vhost-user, the default of queues is 1. 5536 5537 .. parsed-literal:: 5538 5539 # |qemu_system| \\ 5540 [...] \\ 5541 -chardev socket,id=chardev0,path=/path/to/socket \\ 5542 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\ 5543 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5544 [...] 5545 5546 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]`` 5547 \ 5548 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]`` 5549 Defines a secret to store a password, encryption key, or some 5550 other sensitive data. The sensitive data can either be passed 5551 directly via the data parameter, or indirectly via the file 5552 parameter. Using the data parameter is insecure unless the 5553 sensitive data is encrypted. 5554 5555 The sensitive data can be provided in raw format (the default), 5556 or base64. When encoded as JSON, the raw format only supports 5557 valid UTF-8 characters, so base64 is recommended for sending 5558 binary data. QEMU will convert from which ever format is 5559 provided to the format it needs internally. eg, an RBD password 5560 can be provided in raw format, even though it will be base64 5561 encoded when passed onto the RBD sever. 5562 5563 For added protection, it is possible to encrypt the data 5564 associated with a secret using the AES-256-CBC cipher. Use of 5565 encryption is indicated by providing the keyid and iv 5566 parameters. The keyid parameter provides the ID of a previously 5567 defined secret that contains the AES-256 decryption key. This 5568 key should be 32-bytes long and be base64 encoded. The iv 5569 parameter provides the random initialization vector used for 5570 encryption of this particular secret and should be a base64 5571 encrypted string of the 16-byte IV. 5572 5573 The simplest (insecure) usage is to provide the secret inline 5574 5575 .. parsed-literal:: 5576 5577 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw 5578 5579 The simplest secure usage is to provide the secret via a file 5580 5581 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object 5582 secret,id=sec0,file=mypasswd.txt,format=raw 5583 5584 For greater security, AES-256-CBC should be used. To illustrate 5585 usage, consider the openssl command line tool which can encrypt 5586 the data. Note that when encrypting, the plaintext must be 5587 padded to the cipher block size (32 bytes) using the standard 5588 PKCS#5/6 compatible padding algorithm. 5589 5590 First a master key needs to be created in base64 encoding: 5591 5592 :: 5593 5594 # openssl rand -base64 32 > key.b64 5595 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 5596 5597 Each secret to be encrypted needs to have a random 5598 initialization vector generated. These do not need to be kept 5599 secret 5600 5601 :: 5602 5603 # openssl rand -base64 16 > iv.b64 5604 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 5605 5606 The secret to be defined can now be encrypted, in this case 5607 we're telling openssl to base64 encode the result, but it could 5608 be left as raw bytes if desired. 5609 5610 :: 5611 5612 # SECRET=$(printf "letmein" | 5613 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 5614 5615 When launching QEMU, create a master secret pointing to 5616 ``key.b64`` and specify that to be used to decrypt the user 5617 password. Pass the contents of ``iv.b64`` to the second secret 5618 5619 .. parsed-literal:: 5620 5621 # |qemu_system| \\ 5622 -object secret,id=secmaster0,format=base64,file=key.b64 \\ 5623 -object secret,id=sec0,keyid=secmaster0,format=base64,\\ 5624 data=$SECRET,iv=$(<iv.b64) 5625 5626 ``-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]`` 5627 Create a Secure Encrypted Virtualization (SEV) guest object, 5628 which can be used to provide the guest memory encryption support 5629 on AMD processors. 5630 5631 When memory encryption is enabled, one of the physical address 5632 bit (aka the C-bit) is utilized to mark if a memory page is 5633 protected. The ``cbitpos`` is used to provide the C-bit 5634 position. The C-bit position is Host family dependent hence user 5635 must provide this value. On EPYC, the value should be 47. 5636 5637 When memory encryption is enabled, we loose certain bits in 5638 physical address space. The ``reduced-phys-bits`` is used to 5639 provide the number of bits we loose in physical address space. 5640 Similar to C-bit, the value is Host family dependent. On EPYC, 5641 a guest will lose a maximum of 1 bit, so the value should be 1. 5642 5643 The ``sev-device`` provides the device file to use for 5644 communicating with the SEV firmware running inside AMD Secure 5645 Processor. The default device is '/dev/sev'. If hardware 5646 supports memory encryption then /dev/sev devices are created by 5647 CCP driver. 5648 5649 The ``policy`` provides the guest policy to be enforced by the 5650 SEV firmware and restrict what configuration and operational 5651 commands can be performed on this guest by the hypervisor. The 5652 policy should be provided by the guest owner and is bound to the 5653 guest and cannot be changed throughout the lifetime of the 5654 guest. The default is 0. 5655 5656 If guest ``policy`` allows sharing the key with another SEV 5657 guest then ``handle`` can be use to provide handle of the guest 5658 from which to share the key. 5659 5660 The ``dh-cert-file`` and ``session-file`` provides the guest 5661 owner's Public Diffie-Hillman key defined in SEV spec. The PDH 5662 and session parameters are used for establishing a cryptographic 5663 session with the guest owner to negotiate keys used for 5664 attestation. The file must be encoded in base64. 5665 5666 The ``kernel-hashes`` adds the hashes of given kernel/initrd/ 5667 cmdline to a designated guest firmware page for measured Linux 5668 boot with -kernel. The default is off. (Since 6.2) 5669 5670 e.g to launch a SEV guest 5671 5672 .. parsed-literal:: 5673 5674 # |qemu_system_x86| \\ 5675 ...... \\ 5676 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \\ 5677 -machine ...,memory-encryption=sev0 \\ 5678 ..... 5679 5680 ``-object authz-simple,id=id,identity=string`` 5681 Create an authorization object that will control access to 5682 network services. 5683 5684 The ``identity`` parameter is identifies the user and its format 5685 depends on the network service that authorization object is 5686 associated with. For authorizing based on TLS x509 certificates, 5687 the identity must be the x509 distinguished name. Note that care 5688 must be taken to escape any commas in the distinguished name. 5689 5690 An example authorization object to validate a x509 distinguished 5691 name would look like: 5692 5693 .. parsed-literal:: 5694 5695 # |qemu_system| \\ 5696 ... \\ 5697 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\ 5698 ... 5699 5700 Note the use of quotes due to the x509 distinguished name 5701 containing whitespace, and escaping of ','. 5702 5703 ``-object authz-listfile,id=id,filename=path,refresh=on|off`` 5704 Create an authorization object that will control access to 5705 network services. 5706 5707 The ``filename`` parameter is the fully qualified path to a file 5708 containing the access control list rules in JSON format. 5709 5710 An example set of rules that match against SASL usernames might 5711 look like: 5712 5713 :: 5714 5715 { 5716 "rules": [ 5717 { "match": "fred", "policy": "allow", "format": "exact" }, 5718 { "match": "bob", "policy": "allow", "format": "exact" }, 5719 { "match": "danb", "policy": "deny", "format": "glob" }, 5720 { "match": "dan*", "policy": "allow", "format": "exact" }, 5721 ], 5722 "policy": "deny" 5723 } 5724 5725 When checking access the object will iterate over all the rules 5726 and the first rule to match will have its ``policy`` value 5727 returned as the result. If no rules match, then the default 5728 ``policy`` value is returned. 5729 5730 The rules can either be an exact string match, or they can use 5731 the simple UNIX glob pattern matching to allow wildcards to be 5732 used. 5733 5734 If ``refresh`` is set to true the file will be monitored and 5735 automatically reloaded whenever its content changes. 5736 5737 As with the ``authz-simple`` object, the format of the identity 5738 strings being matched depends on the network service, but is 5739 usually a TLS x509 distinguished name, or a SASL username. 5740 5741 An example authorization object to validate a SASL username 5742 would look like: 5743 5744 .. parsed-literal:: 5745 5746 # |qemu_system| \\ 5747 ... \\ 5748 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\ 5749 ... 5750 5751 ``-object authz-pam,id=id,service=string`` 5752 Create an authorization object that will control access to 5753 network services. 5754 5755 The ``service`` parameter provides the name of a PAM service to 5756 use for authorization. It requires that a file 5757 ``/etc/pam.d/service`` exist to provide the configuration for 5758 the ``account`` subsystem. 5759 5760 An example authorization object to validate a TLS x509 5761 distinguished name would look like: 5762 5763 .. parsed-literal:: 5764 5765 # |qemu_system| \\ 5766 ... \\ 5767 -object authz-pam,id=auth0,service=qemu-vnc \\ 5768 ... 5769 5770 There would then be a corresponding config file for PAM at 5771 ``/etc/pam.d/qemu-vnc`` that contains: 5772 5773 :: 5774 5775 account requisite pam_listfile.so item=user sense=allow \ 5776 file=/etc/qemu/vnc.allow 5777 5778 Finally the ``/etc/qemu/vnc.allow`` file would contain the list 5779 of x509 distinguished names that are permitted access 5780 5781 :: 5782 5783 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 5784 5785 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch`` 5786 Creates a dedicated event loop thread that devices can be 5787 assigned to. This is known as an IOThread. By default device 5788 emulation happens in vCPU threads or the main event loop thread. 5789 This can become a scalability bottleneck. IOThreads allow device 5790 emulation and I/O to run on other host CPUs. 5791 5792 The ``id`` parameter is a unique ID that will be used to 5793 reference this IOThread from ``-device ...,iothread=id``. 5794 Multiple devices can be assigned to an IOThread. Note that not 5795 all devices support an ``iothread`` parameter. 5796 5797 The ``query-iothreads`` QMP command lists IOThreads and reports 5798 their thread IDs so that the user can configure host CPU 5799 pinning/affinity. 5800 5801 IOThreads use an adaptive polling algorithm to reduce event loop 5802 latency. Instead of entering a blocking system call to monitor 5803 file descriptors and then pay the cost of being woken up when an 5804 event occurs, the polling algorithm spins waiting for events for 5805 a short time. The algorithm's default parameters are suitable 5806 for many cases but can be adjusted based on knowledge of the 5807 workload and/or host device latency. 5808 5809 The ``poll-max-ns`` parameter is the maximum number of 5810 nanoseconds to busy wait for events. Polling can be disabled by 5811 setting this value to 0. 5812 5813 The ``poll-grow`` parameter is the multiplier used to increase 5814 the polling time when the algorithm detects it is missing events 5815 due to not polling long enough. 5816 5817 The ``poll-shrink`` parameter is the divisor used to decrease 5818 the polling time when the algorithm detects it is spending too 5819 long polling without encountering events. 5820 5821 The ``aio-max-batch`` parameter is the maximum number of requests 5822 in a batch for the AIO engine, 0 means that the engine will use 5823 its default. 5824 5825 The IOThread parameters can be modified at run-time using the 5826 ``qom-set`` command (where ``iothread1`` is the IOThread's 5827 ``id``): 5828 5829 :: 5830 5831 (qemu) qom-set /objects/iothread1 poll-max-ns 100000 5832ERST 5833 5834 5835HXCOMM This is the last statement. Insert new options before this line! 5836 5837#undef DEF 5838#undef DEFHEADING 5839#undef ARCHHEADING 5840
