1HXCOMM Use DEFHEADING() to define headings in both help text and texi 2HXCOMM Text between STEXI and ETEXI are copied to texi 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 texi and C 8 9DEFHEADING(Standard options:) 10STEXI 11@table @option 12ETEXI 13 14DEF("help", 0, QEMU_OPTION_h, 15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL) 16STEXI 17@item -h 18@findex -h 19Display help and exit 20ETEXI 21 22DEF("version", 0, QEMU_OPTION_version, 23 "-version display version information and exit\n", QEMU_ARCH_ALL) 24STEXI 25@item -version 26@findex -version 27Display version information and exit 28ETEXI 29 30DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ 31 "-machine [type=]name[,prop[=value][,...]]\n" 32 " selects emulated machine ('-machine help' for list)\n" 33 " property accel=accel1[:accel2[:...]] selects accelerator\n" 34 " supported accelerators are kvm, xen, hax, hvf, whpx or tcg (default: tcg)\n" 35 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 36 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 37 " mem-merge=on|off controls memory merge support (default: on)\n" 38 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 39 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 40 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 41 " nvdimm=on|off controls NVDIMM support (default=off)\n" 42 " enforce-config-section=on|off enforce configuration section migration (default=off)\n" 43 " memory-encryption=@var{} memory encryption object to use (default=none)\n" 44 " hmat=on|off controls ACPI HMAT support (default=off)\n", 45 QEMU_ARCH_ALL) 46STEXI 47@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 48@findex -machine 49Select the emulated machine by @var{name}. Use @code{-machine help} to list 50available machines. 51 52For architectures which aim to support live migration compatibility 53across releases, each release will introduce a new versioned machine 54type. For example, the 2.8.0 release introduced machine types 55``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures. 56 57To allow live migration of guests from QEMU version 2.8.0, to QEMU 58version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8'' 59and ``pc-q35-2.8'' machines too. To allow users live migrating VMs 60to skip multiple intermediate releases when upgrading, new releases 61of QEMU will support machine types from many previous versions. 62 63Supported machine properties are: 64@table @option 65@item accel=@var{accels1}[:@var{accels2}[:...]] 66This is used to enable an accelerator. Depending on the target architecture, 67kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 68more than one accelerator specified, the next one is used if the previous one 69fails to initialize. 70@item vmport=on|off|auto 71Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 72value based on accel. For accel=xen the default is off otherwise the default 73is on. 74@item dump-guest-core=on|off 75Include guest memory in a core dump. The default is on. 76@item mem-merge=on|off 77Enables or disables memory merge support. This feature, when supported by 78the host, de-duplicates identical memory pages among VMs instances 79(enabled by default). 80@item aes-key-wrap=on|off 81Enables or disables AES key wrapping support on s390-ccw hosts. This feature 82controls whether AES wrapping keys will be created to allow 83execution of AES cryptographic functions. The default is on. 84@item dea-key-wrap=on|off 85Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 86controls whether DEA wrapping keys will be created to allow 87execution of DEA cryptographic functions. The default is on. 88@item nvdimm=on|off 89Enables or disables NVDIMM support. The default is off. 90@item enforce-config-section=on|off 91If @option{enforce-config-section} is set to @var{on}, force migration 92code to send configuration section even if the machine-type sets the 93@option{migration.send-configuration} property to @var{off}. 94NOTE: this parameter is deprecated. Please use @option{-global} 95@option{migration.send-configuration}=@var{on|off} instead. 96@item memory-encryption=@var{} 97Memory encryption object to use. The default is none. 98@item hmat=on|off 99Enables or disables ACPI Heterogeneous Memory Attribute Table (HMAT) support. 100The default is off. 101@end table 102ETEXI 103 104HXCOMM Deprecated by -machine 105DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 106 107DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 108 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 109STEXI 110@item -cpu @var{model} 111@findex -cpu 112Select CPU model (@code{-cpu help} for list and additional feature selection) 113ETEXI 114 115DEF("accel", HAS_ARG, QEMU_OPTION_accel, 116 "-accel [accel=]accelerator[,prop[=value][,...]]\n" 117 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n" 118 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n" 119 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n" 120 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n" 121 " tb-size=n (TCG translation block cache size)\n" 122 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 123STEXI 124@item -accel @var{name}[,prop=@var{value}[,...]] 125@findex -accel 126This is used to enable an accelerator. Depending on the target architecture, 127kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 128more than one accelerator specified, the next one is used if the previous one 129fails to initialize. 130@table @option 131@item igd-passthru=on|off 132When Xen is in use, this option controls whether Intel integrated graphics 133devices can be passed through to the guest (default=off) 134@item kernel-irqchip=on|off|split 135Controls KVM in-kernel irqchip support. The default is full acceleration of the 136interrupt controllers. On x86, split irqchip reduces the kernel attack 137surface, at a performance cost for non-MSI interrupts. Disabling the in-kernel 138irqchip completely is not recommended except for debugging purposes. 139@item kvm-shadow-mem=size 140Defines the size of the KVM shadow MMU. 141@item tb-size=@var{n} 142Controls the size (in MiB) of the TCG translation block cache. 143@item thread=single|multi 144Controls number of TCG threads. When the TCG is multi-threaded there will be one 145thread per vCPU therefor taking advantage of additional host cores. The default 146is to enable multi-threading where both the back-end and front-ends support it and 147no incompatible TCG features have been enabled (e.g. icount/replay). 148@end table 149ETEXI 150 151DEF("smp", HAS_ARG, QEMU_OPTION_smp, 152 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n" 153 " set the number of CPUs to 'n' [default=1]\n" 154 " maxcpus= maximum number of total cpus, including\n" 155 " offline CPUs for hotplug, etc\n" 156 " cores= number of CPU cores on one socket (for PC, it's on one die)\n" 157 " threads= number of threads on one CPU core\n" 158 " dies= number of CPU dies on one socket (for PC only)\n" 159 " sockets= number of discrete sockets in the system\n", 160 QEMU_ARCH_ALL) 161STEXI 162@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,dies=dies][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 163@findex -smp 164Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 165CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 166to 4. 167For the PC target, the number of @var{cores} per die, the number of @var{threads} 168per cores, the number of @var{dies} per packages and the total number of 169@var{sockets} can be specified. Missing values will be computed. 170If any on the three values is given, the total number of CPUs @var{n} can be omitted. 171@var{maxcpus} specifies the maximum number of hotpluggable CPUs. 172ETEXI 173 174DEF("numa", HAS_ARG, QEMU_OPTION_numa, 175 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 176 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 177 "-numa dist,src=source,dst=destination,val=distance\n" 178 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n" 179 "-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" 180 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n", 181 QEMU_ARCH_ALL) 182STEXI 183@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}][,initiator=@var{initiator}] 184@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}][,initiator=@var{initiator}] 185@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 186@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 187@itemx -numa hmat-lb,initiator=@var{node},target=@var{node},hierarchy=@var{hierarchy},data-type=@var{tpye}[,latency=@var{lat}][,bandwidth=@var{bw}] 188@itemx -numa hmat-cache,node-id=@var{node},size=@var{size},level=@var{level}[,associativity=@var{str}][,policy=@var{str}][,line=@var{size}] 189@findex -numa 190Define a NUMA node and assign RAM and VCPUs to it. 191Set the NUMA distance from a source node to a destination node. 192Set the ACPI Heterogeneous Memory Attributes for the given nodes. 193 194Legacy VCPU assignment uses @samp{cpus} option where 195@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 196@samp{cpus} option represent a contiguous range of CPU indexes 197(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 198set of VCPUs can be represented by providing multiple @samp{cpus} 199options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 200split between them. 201 202For example, the following option assigns VCPUs 0, 1, 2 and 5 to 203a NUMA node: 204@example 205-numa node,cpus=0-2,cpus=5 206@end example 207 208@samp{cpu} option is a new alternative to @samp{cpus} option 209which uses @samp{socket-id|core-id|thread-id} properties to assign 210CPU objects to a @var{node} using topology layout properties of CPU. 211The set of properties is machine specific, and depends on used 212machine type/@samp{smp} options. It could be queried with 213@samp{hotpluggable-cpus} monitor command. 214@samp{node-id} property specifies @var{node} to which CPU object 215will be assigned, it's required for @var{node} to be declared 216with @samp{node} option before it's used with @samp{cpu} option. 217 218For example: 219@example 220-M pc \ 221-smp 1,sockets=2,maxcpus=2 \ 222-numa node,nodeid=0 -numa node,nodeid=1 \ 223-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 224@end example 225 226@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 227assigns RAM from a given memory backend device to a node. If 228@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 229split equally between them. 230 231@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 232if one node uses @samp{memdev}, all of them have to use it. 233 234@samp{initiator} is an additional option that points to an @var{initiator} 235NUMA node that has best performance (the lowest latency or largest bandwidth) 236to this NUMA @var{node}. Note that this option can be set only when 237the machine property 'hmat' is set to 'on'. 238 239Following example creates a machine with 2 NUMA nodes, node 0 has CPU. 240node 1 has only memory, and its initiator is node 0. Note that because 241node 0 has CPU, by default the initiator of node 0 is itself and must be 242itself. 243@example 244-machine hmat=on \ 245-m 2G,slots=2,maxmem=4G \ 246-object memory-backend-ram,size=1G,id=m0 \ 247-object memory-backend-ram,size=1G,id=m1 \ 248-numa node,nodeid=0,memdev=m0 \ 249-numa node,nodeid=1,memdev=m1,initiator=0 \ 250-smp 2,sockets=2,maxcpus=2 \ 251-numa cpu,node-id=0,socket-id=0 \ 252-numa cpu,node-id=0,socket-id=1 253@end example 254 255@var{source} and @var{destination} are NUMA node IDs. 256@var{distance} is the NUMA distance from @var{source} to @var{destination}. 257The distance from a node to itself is always 10. If any pair of nodes is 258given a distance, then all pairs must be given distances. Although, when 259distances are only given in one direction for each pair of nodes, then 260the distances in the opposite directions are assumed to be the same. If, 261however, an asymmetrical pair of distances is given for even one node 262pair, then all node pairs must be provided distance values for both 263directions, even when they are symmetrical. When a node is unreachable 264from another node, set the pair's distance to 255. 265 266Note that the -@option{numa} option doesn't allocate any of the 267specified resources, it just assigns existing resources to NUMA 268nodes. This means that one still has to use the @option{-m}, 269@option{-smp} options to allocate RAM and VCPUs respectively. 270 271Use @samp{hmat-lb} to set System Locality Latency and Bandwidth Information 272between initiator and target NUMA nodes in ACPI Heterogeneous Attribute Memory Table (HMAT). 273Initiator NUMA node can create memory requests, usually it has one or more processors. 274Target NUMA node contains addressable memory. 275 276In @samp{hmat-lb} option, @var{node} are NUMA node IDs. @var{hierarchy} is the memory 277hierarchy of the target NUMA node: if @var{hierarchy} is 'memory', the structure 278represents the memory performance; if @var{hierarchy} is 'first-level|second-level|third-level', 279this structure represents aggregated performance of memory side caches for each domain. 280@var{type} of 'data-type' is type of data represented by this structure instance: 281if 'hierarchy' is 'memory', 'data-type' is 'access|read|write' latency or 'access|read|write' 282bandwidth of the target memory; if 'hierarchy' is 'first-level|second-level|third-level', 283'data-type' is 'access|read|write' hit latency or 'access|read|write' hit bandwidth of the 284target memory side cache. 285 286@var{lat} is latency value in nanoseconds. @var{bw} is bandwidth value, 287the possible value and units are NUM[M|G|T], mean that the bandwidth value are 288NUM byte per second (or MB/s, GB/s or TB/s depending on used suffix). 289Note that if latency or bandwidth value is 0, means the corresponding latency or 290bandwidth information is not provided. 291 292In @samp{hmat-cache} option, @var{node-id} is the NUMA-id of the memory belongs. 293@var{size} is the size of memory side cache in bytes. @var{level} is the cache 294level described in this structure, note that the cache level 0 should not be used 295with @samp{hmat-cache} option. @var{associativity} is the cache associativity, 296the possible value is 'none/direct(direct-mapped)/complex(complex cache indexing)'. 297@var{policy} is the write policy. @var{line} is the cache Line size in bytes. 298 299For example, the following options describe 2 NUMA nodes. Node 0 has 2 cpus and 300a ram, node 1 has only a ram. The processors in node 0 access memory in node 3010 with access-latency 5 nanoseconds, access-bandwidth is 200 MB/s; 302The processors in NUMA node 0 access memory in NUMA node 1 with access-latency 10 303nanoseconds, access-bandwidth is 100 MB/s. 304And for memory side cache information, NUMA node 0 and 1 both have 1 level memory 305cache, size is 10KB, policy is write-back, the cache Line size is 8 bytes: 306@example 307-machine hmat=on \ 308-m 2G \ 309-object memory-backend-ram,size=1G,id=m0 \ 310-object memory-backend-ram,size=1G,id=m1 \ 311-smp 2 \ 312-numa node,nodeid=0,memdev=m0 \ 313-numa node,nodeid=1,memdev=m1,initiator=0 \ 314-numa cpu,node-id=0,socket-id=0 \ 315-numa cpu,node-id=0,socket-id=1 \ 316-numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \ 317-numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \ 318-numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \ 319-numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \ 320-numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \ 321-numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8 322@end example 323 324ETEXI 325 326DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 327 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 328 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 329STEXI 330@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 331@findex -add-fd 332 333Add a file descriptor to an fd set. Valid options are: 334 335@table @option 336@item fd=@var{fd} 337This option defines the file descriptor of which a duplicate is added to fd set. 338The file descriptor cannot be stdin, stdout, or stderr. 339@item set=@var{set} 340This option defines the ID of the fd set to add the file descriptor to. 341@item opaque=@var{opaque} 342This option defines a free-form string that can be used to describe @var{fd}. 343@end table 344 345You can open an image using pre-opened file descriptors from an fd set: 346@example 347@value{qemu_system} \ 348 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 349 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 350 -drive file=/dev/fdset/2,index=0,media=disk 351@end example 352ETEXI 353 354DEF("set", HAS_ARG, QEMU_OPTION_set, 355 "-set group.id.arg=value\n" 356 " set <arg> parameter for item <id> of type <group>\n" 357 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 358STEXI 359@item -set @var{group}.@var{id}.@var{arg}=@var{value} 360@findex -set 361Set parameter @var{arg} for item @var{id} of type @var{group} 362ETEXI 363 364DEF("global", HAS_ARG, QEMU_OPTION_global, 365 "-global driver.property=value\n" 366 "-global driver=driver,property=property,value=value\n" 367 " set a global default for a driver property\n", 368 QEMU_ARCH_ALL) 369STEXI 370@item -global @var{driver}.@var{prop}=@var{value} 371@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 372@findex -global 373Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 374 375@example 376@value{qemu_system_x86} -global ide-hd.physical_block_size=4096 disk-image.img 377@end example 378 379In particular, you can use this to set driver properties for devices which are 380created automatically by the machine model. To create a device which is not 381created automatically and set properties on it, use -@option{device}. 382 383-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 384driver=@var{driver},property=@var{prop},value=@var{value}. The 385longhand syntax works even when @var{driver} contains a dot. 386ETEXI 387 388DEF("boot", HAS_ARG, QEMU_OPTION_boot, 389 "-boot [order=drives][,once=drives][,menu=on|off]\n" 390 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 391 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 392 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 393 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 394 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 395 QEMU_ARCH_ALL) 396STEXI 397@item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}][,reboot-timeout=@var{rb_timeout}][,strict=on|off] 398@findex -boot 399Specify boot order @var{drives} as a string of drive letters. Valid 400drive letters depend on the target architecture. The x86 PC uses: a, b 401(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 402from network adapter 1-4), hard disk boot is the default. To apply a 403particular boot order only on the first startup, specify it via 404@option{once}. Note that the @option{order} or @option{once} parameter 405should not be used together with the @option{bootindex} property of 406devices, since the firmware implementations normally do not support both 407at the same time. 408 409Interactive boot menus/prompts can be enabled via @option{menu=on} as far 410as firmware/BIOS supports them. The default is non-interactive boot. 411 412A splash picture could be passed to bios, enabling user to show it as logo, 413when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 414supports them. Currently Seabios for X86 system support it. 415limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 416format(true color). The resolution should be supported by the SVGA mode, so 417the recommended is 320x240, 640x480, 800x640. 418 419A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 420when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 421reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 422system support it. 423 424Do strict boot via @option{strict=on} as far as firmware/BIOS 425supports it. This only effects when boot priority is changed by 426bootindex options. The default is non-strict boot. 427 428@example 429# try to boot from network first, then from hard disk 430@value{qemu_system_x86} -boot order=nc 431# boot from CD-ROM first, switch back to default order after reboot 432@value{qemu_system_x86} -boot once=d 433# boot with a splash picture for 5 seconds. 434@value{qemu_system_x86} -boot menu=on,splash=/root/boot.bmp,splash-time=5000 435@end example 436 437Note: The legacy format '-boot @var{drives}' is still supported but its 438use is discouraged as it may be removed from future versions. 439ETEXI 440 441DEF("m", HAS_ARG, QEMU_OPTION_m, 442 "-m [size=]megs[,slots=n,maxmem=size]\n" 443 " configure guest RAM\n" 444 " size: initial amount of guest memory\n" 445 " slots: number of hotplug slots (default: none)\n" 446 " maxmem: maximum amount of guest memory (default: none)\n" 447 "NOTE: Some architectures might enforce a specific granularity\n", 448 QEMU_ARCH_ALL) 449STEXI 450@item -m [size=]@var{megs}[,slots=n,maxmem=size] 451@findex -m 452Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 453Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 454megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 455could be used to set amount of hotpluggable memory slots and maximum amount of 456memory. Note that @var{maxmem} must be aligned to the page size. 457 458For example, the following command-line sets the guest startup RAM size to 4591GB, creates 3 slots to hotplug additional memory and sets the maximum 460memory the guest can reach to 4GB: 461 462@example 463@value{qemu_system} -m 1G,slots=3,maxmem=4G 464@end example 465 466If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 467be enabled and the guest startup RAM will never increase. 468ETEXI 469 470DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 471 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 472STEXI 473@item -mem-path @var{path} 474@findex -mem-path 475Allocate guest RAM from a temporarily created file in @var{path}. 476ETEXI 477 478DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 479 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 480 QEMU_ARCH_ALL) 481STEXI 482@item -mem-prealloc 483@findex -mem-prealloc 484Preallocate memory when using -mem-path. 485ETEXI 486 487DEF("k", HAS_ARG, QEMU_OPTION_k, 488 "-k language use keyboard layout (for example 'fr' for French)\n", 489 QEMU_ARCH_ALL) 490STEXI 491@item -k @var{language} 492@findex -k 493Use keyboard layout @var{language} (for example @code{fr} for 494French). This option is only needed where it is not easy to get raw PC 495keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 496display). You don't normally need to use it on PC/Linux or PC/Windows 497hosts. 498 499The available layouts are: 500@example 501ar de-ch es fo fr-ca hu ja mk no pt-br sv 502da en-gb et fr fr-ch is lt nl pl ru th 503de en-us fi fr-be hr it lv nl-be pt sl tr 504@end example 505 506The default is @code{en-us}. 507ETEXI 508 509 510HXCOMM Deprecated by -audiodev 511DEF("audio-help", 0, QEMU_OPTION_audio_help, 512 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 513 QEMU_ARCH_ALL) 514STEXI 515@item -audio-help 516@findex -audio-help 517Will show the -audiodev equivalent of the currently specified 518(deprecated) environment variables. 519ETEXI 520 521DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 522 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 523 " specifies the audio backend to use\n" 524 " id= identifier of the backend\n" 525 " timer-period= timer period in microseconds\n" 526 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 527 " in|out.fixed-settings= use fixed settings for host audio\n" 528 " in|out.frequency= frequency to use with fixed settings\n" 529 " in|out.channels= number of channels to use with fixed settings\n" 530 " in|out.format= sample format to use with fixed settings\n" 531 " valid values: s8, s16, s32, u8, u16, u32\n" 532 " in|out.voices= number of voices to use\n" 533 " in|out.buffer-length= length of buffer in microseconds\n" 534 "-audiodev none,id=id,[,prop[=value][,...]]\n" 535 " dummy driver that discards all output\n" 536#ifdef CONFIG_AUDIO_ALSA 537 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 538 " in|out.dev= name of the audio device to use\n" 539 " in|out.period-length= length of period in microseconds\n" 540 " in|out.try-poll= attempt to use poll mode\n" 541 " threshold= threshold (in microseconds) when playback starts\n" 542#endif 543#ifdef CONFIG_AUDIO_COREAUDIO 544 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 545 " in|out.buffer-count= number of buffers\n" 546#endif 547#ifdef CONFIG_AUDIO_DSOUND 548 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 549 " latency= add extra latency to playback in microseconds\n" 550#endif 551#ifdef CONFIG_AUDIO_OSS 552 "-audiodev oss,id=id[,prop[=value][,...]]\n" 553 " in|out.dev= path of the audio device to use\n" 554 " in|out.buffer-count= number of buffers\n" 555 " in|out.try-poll= attempt to use poll mode\n" 556 " try-mmap= try using memory mapped access\n" 557 " exclusive= open device in exclusive mode\n" 558 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 559#endif 560#ifdef CONFIG_AUDIO_PA 561 "-audiodev pa,id=id[,prop[=value][,...]]\n" 562 " server= PulseAudio server address\n" 563 " in|out.name= source/sink device name\n" 564 " in|out.latency= desired latency in microseconds\n" 565#endif 566#ifdef CONFIG_AUDIO_SDL 567 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 568#endif 569#ifdef CONFIG_SPICE 570 "-audiodev spice,id=id[,prop[=value][,...]]\n" 571#endif 572 "-audiodev wav,id=id[,prop[=value][,...]]\n" 573 " path= path of wav file to record\n", 574 QEMU_ARCH_ALL) 575STEXI 576@item -audiodev [driver=]@var{driver},id=@var{id}[,@var{prop}[=@var{value}][,...]] 577@findex -audiodev 578Adds a new audio backend @var{driver} identified by @var{id}. There are 579global and driver specific properties. Some values can be set 580differently for input and output, they're marked with @code{in|out.}. 581You can set the input's property with @code{in.@var{prop}} and the 582output's property with @code{out.@var{prop}}. For example: 583@example 584-audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 585-audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 586@end example 587 588NOTE: parameter validation is known to be incomplete, in many cases 589specifying an invalid option causes QEMU to print an error message and 590continue emulation without sound. 591 592Valid global options are: 593 594@table @option 595@item id=@var{identifier} 596Identifies the audio backend. 597 598@item timer-period=@var{period} 599Sets the timer @var{period} used by the audio subsystem in microseconds. 600Default is 10000 (10 ms). 601 602@item in|out.mixing-engine=on|off 603Use QEMU's mixing engine to mix all streams inside QEMU and convert 604audio formats when not supported by the backend. When off, 605@var{fixed-settings} must be off too. Note that disabling this option 606means that the selected backend must support multiple streams and the 607audio formats used by the virtual cards, otherwise you'll get no sound. 608It's not recommended to disable this option unless you want to use 5.1 609or 7.1 audio, as mixing engine only supports mono and stereo audio. 610Default is on. 611 612@item in|out.fixed-settings=on|off 613Use fixed settings for host audio. When off, it will change based on 614how the guest opens the sound card. In this case you must not specify 615@var{frequency}, @var{channels} or @var{format}. Default is on. 616 617@item in|out.frequency=@var{frequency} 618Specify the @var{frequency} to use when using @var{fixed-settings}. 619Default is 44100Hz. 620 621@item in|out.channels=@var{channels} 622Specify the number of @var{channels} to use when using 623@var{fixed-settings}. Default is 2 (stereo). 624 625@item in|out.format=@var{format} 626Specify the sample @var{format} to use when using @var{fixed-settings}. 627Valid values are: @code{s8}, @code{s16}, @code{s32}, @code{u8}, 628@code{u16}, @code{u32}. Default is @code{s16}. 629 630@item in|out.voices=@var{voices} 631Specify the number of @var{voices} to use. Default is 1. 632 633@item in|out.buffer-length=@var{usecs} 634Sets the size of the buffer in microseconds. 635 636@end table 637 638@item -audiodev none,id=@var{id}[,@var{prop}[=@var{value}][,...]] 639Creates a dummy backend that discards all outputs. This backend has no 640backend specific properties. 641 642@item -audiodev alsa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 643Creates backend using the ALSA. This backend is only available on 644Linux. 645 646ALSA specific options are: 647 648@table @option 649 650@item in|out.dev=@var{device} 651Specify the ALSA @var{device} to use for input and/or output. Default 652is @code{default}. 653 654@item in|out.period-length=@var{usecs} 655Sets the period length in microseconds. 656 657@item in|out.try-poll=on|off 658Attempt to use poll mode with the device. Default is on. 659 660@item threshold=@var{threshold} 661Threshold (in microseconds) when playback starts. Default is 0. 662 663@end table 664 665@item -audiodev coreaudio,id=@var{id}[,@var{prop}[=@var{value}][,...]] 666Creates a backend using Apple's Core Audio. This backend is only 667available on Mac OS and only supports playback. 668 669Core Audio specific options are: 670 671@table @option 672 673@item in|out.buffer-count=@var{count} 674Sets the @var{count} of the buffers. 675 676@end table 677 678@item -audiodev dsound,id=@var{id}[,@var{prop}[=@var{value}][,...]] 679Creates a backend using Microsoft's DirectSound. This backend is only 680available on Windows and only supports playback. 681 682DirectSound specific options are: 683 684@table @option 685 686@item latency=@var{usecs} 687Add extra @var{usecs} microseconds latency to playback. Default is 68810000 (10 ms). 689 690@end table 691 692@item -audiodev oss,id=@var{id}[,@var{prop}[=@var{value}][,...]] 693Creates a backend using OSS. This backend is available on most 694Unix-like systems. 695 696OSS specific options are: 697 698@table @option 699 700@item in|out.dev=@var{device} 701Specify the file name of the OSS @var{device} to use. Default is 702@code{/dev/dsp}. 703 704@item in|out.buffer-count=@var{count} 705Sets the @var{count} of the buffers. 706 707@item in|out.try-poll=on|of 708Attempt to use poll mode with the device. Default is on. 709 710@item try-mmap=on|off 711Try using memory mapped device access. Default is off. 712 713@item exclusive=on|off 714Open the device in exclusive mode (vmix won't work in this case). 715Default is off. 716 717@item dsp-policy=@var{policy} 718Sets the timing policy (between 0 and 10, where smaller number means 719smaller latency but higher CPU usage). Use -1 to use buffer sizes 720specified by @code{buffer} and @code{buffer-count}. This option is 721ignored if you do not have OSS 4. Default is 5. 722 723@end table 724 725@item -audiodev pa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 726Creates a backend using PulseAudio. This backend is available on most 727systems. 728 729PulseAudio specific options are: 730 731@table @option 732 733@item server=@var{server} 734Sets the PulseAudio @var{server} to connect to. 735 736@item in|out.name=@var{sink} 737Use the specified source/sink for recording/playback. 738 739@item in|out.latency=@var{usecs} 740Desired latency in microseconds. The PulseAudio server will try to honor this 741value but actual latencies may be lower or higher. 742 743@end table 744 745@item -audiodev sdl,id=@var{id}[,@var{prop}[=@var{value}][,...]] 746Creates a backend using SDL. This backend is available on most systems, 747but you should use your platform's native backend if possible. This 748backend has no backend specific properties. 749 750@item -audiodev spice,id=@var{id}[,@var{prop}[=@var{value}][,...]] 751Creates a backend that sends audio through SPICE. This backend requires 752@code{-spice} and automatically selected in that case, so usually you 753can ignore this option. This backend has no backend specific 754properties. 755 756@item -audiodev wav,id=@var{id}[,@var{prop}[=@var{value}][,...]] 757Creates a backend that writes audio to a WAV file. 758 759Backend specific options are: 760 761@table @option 762 763@item path=@var{path} 764Write recorded audio into the specified file. Default is 765@code{qemu.wav}. 766 767@end table 768ETEXI 769 770DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 771 "-soundhw c1,... enable audio support\n" 772 " and only specified sound cards (comma separated list)\n" 773 " use '-soundhw help' to get the list of supported cards\n" 774 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 775STEXI 776@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 777@findex -soundhw 778Enable audio and selected sound hardware. Use 'help' to print all 779available sound hardware. For example: 780 781@example 782@value{qemu_system_x86} -soundhw sb16,adlib disk.img 783@value{qemu_system_x86} -soundhw es1370 disk.img 784@value{qemu_system_x86} -soundhw ac97 disk.img 785@value{qemu_system_x86} -soundhw hda disk.img 786@value{qemu_system_x86} -soundhw all disk.img 787@value{qemu_system_x86} -soundhw help 788@end example 789 790Note that Linux's i810_audio OSS kernel (for AC97) module might 791require manually specifying clocking. 792 793@example 794modprobe i810_audio clocking=48000 795@end example 796ETEXI 797 798DEF("device", HAS_ARG, QEMU_OPTION_device, 799 "-device driver[,prop[=value][,...]]\n" 800 " add device (based on driver)\n" 801 " prop=value,... sets driver properties\n" 802 " use '-device help' to print all possible drivers\n" 803 " use '-device driver,help' to print all possible properties\n", 804 QEMU_ARCH_ALL) 805STEXI 806@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 807@findex -device 808Add device @var{driver}. @var{prop}=@var{value} sets driver 809properties. Valid properties depend on the driver. To get help on 810possible drivers and properties, use @code{-device help} and 811@code{-device @var{driver},help}. 812 813Some drivers are: 814@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}][,guid=@var{uuid}] 815 816Add an IPMI BMC. This is a simulation of a hardware management 817interface processor that normally sits on a system. It provides 818a watchdog and the ability to reset and power control the system. 819You need to connect this to an IPMI interface to make it useful 820 821The IPMI slave address to use for the BMC. The default is 0x20. 822This address is the BMC's address on the I2C network of management 823controllers. If you don't know what this means, it is safe to ignore 824it. 825 826@table @option 827@item id=@var{id} 828The BMC id for interfaces to use this device. 829@item slave_addr=@var{val} 830Define slave address to use for the BMC. The default is 0x20. 831@item sdrfile=@var{file} 832file containing raw Sensor Data Records (SDR) data. The default is none. 833@item fruareasize=@var{val} 834size of a Field Replaceable Unit (FRU) area. The default is 1024. 835@item frudatafile=@var{file} 836file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 837@item guid=@var{uuid} 838value for the GUID for the BMC, in standard UUID format. If this is set, 839get "Get GUID" command to the BMC will return it. Otherwise "Get GUID" 840will return an error. 841@end table 842 843@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 844 845Add a connection to an external IPMI BMC simulator. Instead of 846locally emulating the BMC like the above item, instead connect 847to an external entity that provides the IPMI services. 848 849A connection is made to an external BMC simulator. If you do this, it 850is strongly recommended that you use the "reconnect=" chardev option 851to reconnect to the simulator if the connection is lost. Note that if 852this is not used carefully, it can be a security issue, as the 853interface has the ability to send resets, NMIs, and power off the VM. 854It's best if QEMU makes a connection to an external simulator running 855on a secure port on localhost, so neither the simulator nor QEMU is 856exposed to any outside network. 857 858See the "lanserv/README.vm" file in the OpenIPMI library for more 859details on the external interface. 860 861@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 862 863Add a KCS IPMI interafce on the ISA bus. This also adds a 864corresponding ACPI and SMBIOS entries, if appropriate. 865 866@table @option 867@item bmc=@var{id} 868The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 869@item ioport=@var{val} 870Define the I/O address of the interface. The default is 0xca0 for KCS. 871@item irq=@var{val} 872Define the interrupt to use. The default is 5. To disable interrupts, 873set this to 0. 874@end table 875 876@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 877 878Like the KCS interface, but defines a BT interface. The default port is 8790xe4 and the default interrupt is 5. 880 881ETEXI 882 883DEF("name", HAS_ARG, QEMU_OPTION_name, 884 "-name string1[,process=string2][,debug-threads=on|off]\n" 885 " set the name of the guest\n" 886 " string1 sets the window title and string2 the process name\n" 887 " When debug-threads is enabled, individual threads are given a separate name\n" 888 " NOTE: The thread names are for debugging and not a stable API.\n", 889 QEMU_ARCH_ALL) 890STEXI 891@item -name @var{name} 892@findex -name 893Sets the @var{name} of the guest. 894This name will be displayed in the SDL window caption. 895The @var{name} will also be used for the VNC server. 896Also optionally set the top visible process name in Linux. 897Naming of individual threads can also be enabled on Linux to aid debugging. 898ETEXI 899 900DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 901 "-uuid %08x-%04x-%04x-%04x-%012x\n" 902 " specify machine UUID\n", QEMU_ARCH_ALL) 903STEXI 904@item -uuid @var{uuid} 905@findex -uuid 906Set system UUID. 907ETEXI 908 909STEXI 910@end table 911ETEXI 912DEFHEADING() 913 914DEFHEADING(Block device options:) 915STEXI 916@table @option 917ETEXI 918 919DEF("fda", HAS_ARG, QEMU_OPTION_fda, 920 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 921DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 922STEXI 923@item -fda @var{file} 924@itemx -fdb @var{file} 925@findex -fda 926@findex -fdb 927Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 928ETEXI 929 930DEF("hda", HAS_ARG, QEMU_OPTION_hda, 931 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 932DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 933DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 934 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 935DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 936STEXI 937@item -hda @var{file} 938@itemx -hdb @var{file} 939@itemx -hdc @var{file} 940@itemx -hdd @var{file} 941@findex -hda 942@findex -hdb 943@findex -hdc 944@findex -hdd 945Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 946ETEXI 947 948DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 949 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 950 QEMU_ARCH_ALL) 951STEXI 952@item -cdrom @var{file} 953@findex -cdrom 954Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 955@option{-cdrom} at the same time). You can use the host CD-ROM by 956using @file{/dev/cdrom} as filename (@pxref{host_drives}). 957ETEXI 958 959DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 960 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 961 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 962 " [,read-only=on|off][,auto-read-only=on|off]\n" 963 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 964 " [,driver specific parameters...]\n" 965 " configure a block backend\n", QEMU_ARCH_ALL) 966STEXI 967@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 968@findex -blockdev 969 970Define a new block driver node. Some of the options apply to all block drivers, 971other options are only accepted for a specific block driver. See below for a 972list of generic options and options for the most common block drivers. 973 974Options that expect a reference to another node (e.g. @code{file}) can be 975given in two ways. Either you specify the node name of an already existing node 976(file=@var{node-name}), or you define a new node inline, adding options 977for the referenced node after a dot (file.filename=@var{path},file.aio=native). 978 979A block driver node created with @option{-blockdev} can be used for a guest 980device by specifying its node name for the @code{drive} property in a 981@option{-device} argument that defines a block device. 982 983@table @option 984@item Valid options for any block driver node: 985 986@table @code 987@item driver 988Specifies the block driver to use for the given node. 989@item node-name 990This defines the name of the block driver node by which it will be referenced 991later. The name must be unique, i.e. it must not match the name of a different 992block driver node, or (if you use @option{-drive} as well) the ID of a drive. 993 994If no node name is specified, it is automatically generated. The generated node 995name is not intended to be predictable and changes between QEMU invocations. 996For the top level, an explicit node name must be specified. 997@item read-only 998Open the node read-only. Guest write attempts will fail. 999 1000Note that some block drivers support only read-only access, either generally or 1001in certain configurations. In this case, the default value 1002@option{read-only=off} does not work and the option must be specified 1003explicitly. 1004@item auto-read-only 1005If @option{auto-read-only=on} is set, QEMU may fall back to read-only usage 1006even when @option{read-only=off} is requested, or even switch between modes as 1007needed, e.g. depending on whether the image file is writable or whether a 1008writing user is attached to the node. 1009@item force-share 1010Override the image locking system of QEMU by forcing the node to utilize 1011weaker shared access for permissions where it would normally request exclusive 1012access. When there is the potential for multiple instances to have the same 1013file open (whether this invocation of QEMU is the first or the second 1014instance), both instances must permit shared access for the second instance to 1015succeed at opening the file. 1016 1017Enabling @option{force-share=on} requires @option{read-only=on}. 1018@item cache.direct 1019The host page cache can be avoided with @option{cache.direct=on}. This will 1020attempt to do disk IO directly to the guest's memory. QEMU may still perform an 1021internal copy of the data. 1022@item cache.no-flush 1023In case you don't care about data integrity over host failures, you can use 1024@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 1025any data to the disk but can instead keep things in cache. If anything goes 1026wrong, like your host losing power, the disk storage getting disconnected 1027accidentally, etc. your image will most probably be rendered unusable. 1028@item discard=@var{discard} 1029@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 1030whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 1031ignored or passed to the filesystem. Some machine types may not support 1032discard requests. 1033@item detect-zeroes=@var{detect-zeroes} 1034@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 1035conversion of plain zero writes by the OS to driver specific optimized 1036zero write commands. You may even choose "unmap" if @var{discard} is set 1037to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 1038@end table 1039 1040@item Driver-specific options for @code{file} 1041 1042This is the protocol-level block driver for accessing regular files. 1043 1044@table @code 1045@item filename 1046The path to the image file in the local filesystem 1047@item aio 1048Specifies the AIO backend (threads/native, default: threads) 1049@item locking 1050Specifies whether the image file is protected with Linux OFD / POSIX locks. The 1051default is to use the Linux Open File Descriptor API if available, otherwise no 1052lock is applied. (auto/on/off, default: auto) 1053@end table 1054Example: 1055@example 1056-blockdev driver=file,node-name=disk,filename=disk.img 1057@end example 1058 1059@item Driver-specific options for @code{raw} 1060 1061This is the image format block driver for raw images. It is usually 1062stacked on top of a protocol level block driver such as @code{file}. 1063 1064@table @code 1065@item file 1066Reference to or definition of the data source block driver node 1067(e.g. a @code{file} driver node) 1068@end table 1069Example 1: 1070@example 1071-blockdev driver=file,node-name=disk_file,filename=disk.img 1072-blockdev driver=raw,node-name=disk,file=disk_file 1073@end example 1074Example 2: 1075@example 1076-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1077@end example 1078 1079@item Driver-specific options for @code{qcow2} 1080 1081This is the image format block driver for qcow2 images. It is usually 1082stacked on top of a protocol level block driver such as @code{file}. 1083 1084@table @code 1085@item file 1086Reference to or definition of the data source block driver node 1087(e.g. a @code{file} driver node) 1088 1089@item backing 1090Reference to or definition of the backing file block device (default is taken 1091from the image file). It is allowed to pass @code{null} here in order to disable 1092the default backing file. 1093 1094@item lazy-refcounts 1095Whether to enable the lazy refcounts feature (on/off; default is taken from the 1096image file) 1097 1098@item cache-size 1099The maximum total size of the L2 table and refcount block caches in bytes 1100(default: the sum of l2-cache-size and refcount-cache-size) 1101 1102@item l2-cache-size 1103The maximum size of the L2 table cache in bytes 1104(default: if cache-size is not specified - 32M on Linux platforms, and 8M on 1105non-Linux platforms; otherwise, as large as possible within the cache-size, 1106while permitting the requested or the minimal refcount cache size) 1107 1108@item refcount-cache-size 1109The maximum size of the refcount block cache in bytes 1110(default: 4 times the cluster size; or if cache-size is specified, the part of 1111it which is not used for the L2 cache) 1112 1113@item cache-clean-interval 1114Clean unused entries in the L2 and refcount caches. The interval is in seconds. 1115The default value is 600 on supporting platforms, and 0 on other platforms. 1116Setting it to 0 disables this feature. 1117 1118@item pass-discard-request 1119Whether discard requests to the qcow2 device should be forwarded to the data 1120source (on/off; default: on if discard=unmap is specified, off otherwise) 1121 1122@item pass-discard-snapshot 1123Whether discard requests for the data source should be issued when a snapshot 1124operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 1125default: on) 1126 1127@item pass-discard-other 1128Whether discard requests for the data source should be issued on other 1129occasions where a cluster gets freed (on/off; default: off) 1130 1131@item overlap-check 1132Which overlap checks to perform for writes to the image 1133(none/constant/cached/all; default: cached). For details or finer 1134granularity control refer to the QAPI documentation of @code{blockdev-add}. 1135@end table 1136 1137Example 1: 1138@example 1139-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1140-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1141@end example 1142Example 2: 1143@example 1144-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1145@end example 1146 1147@item Driver-specific options for other drivers 1148Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 1149 1150@end table 1151 1152ETEXI 1153 1154DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1155 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1156 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1157 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1158 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 1159 " [,readonly=on|off][,copy-on-read=on|off]\n" 1160 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1161 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1162 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1163 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1164 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1165 " [[,iops_size=is]]\n" 1166 " [[,group=g]]\n" 1167 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1168STEXI 1169@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 1170@findex -drive 1171 1172Define a new drive. This includes creating a block driver node (the backend) as 1173well as a guest device, and is mostly a shortcut for defining the corresponding 1174@option{-blockdev} and @option{-device} options. 1175 1176@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 1177addition, it knows the following options: 1178 1179@table @option 1180@item file=@var{file} 1181This option defines which disk image (@pxref{disk_images}) to use with 1182this drive. If the filename contains comma, you must double it 1183(for instance, "file=my,,file" to use file "my,file"). 1184 1185Special files such as iSCSI devices can be specified using protocol 1186specific URLs. See the section for "Device URL Syntax" for more information. 1187@item if=@var{interface} 1188This option defines on which type on interface the drive is connected. 1189Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 1190@item bus=@var{bus},unit=@var{unit} 1191These options define where is connected the drive by defining the bus number and 1192the unit id. 1193@item index=@var{index} 1194This option defines where is connected the drive by using an index in the list 1195of available connectors of a given interface type. 1196@item media=@var{media} 1197This option defines the type of the media: disk or cdrom. 1198@item snapshot=@var{snapshot} 1199@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 1200(see @option{-snapshot}). 1201@item cache=@var{cache} 1202@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 1203and controls how the host cache is used to access block data. This is a 1204shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 1205options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 1206which provides a default for the @option{write-cache} option of block guest 1207devices (as in @option{-device}). The modes correspond to the following 1208settings: 1209 1210@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 1211@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 1212@c and the HTML output. 1213@example 1214@ │ cache.writeback cache.direct cache.no-flush 1215─────────────┼───────────────────────────────────────────────── 1216writeback │ on off off 1217none │ on on off 1218writethrough │ off off off 1219directsync │ off on off 1220unsafe │ on off on 1221@end example 1222 1223The default mode is @option{cache=writeback}. 1224 1225@item aio=@var{aio} 1226@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 1227@item format=@var{format} 1228Specify which disk @var{format} will be used rather than detecting 1229the format. Can be used to specify format=raw to avoid interpreting 1230an untrusted format header. 1231@item werror=@var{action},rerror=@var{action} 1232Specify which @var{action} to take on write and read errors. Valid actions are: 1233"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 1234"report" (report the error to the guest), "enospc" (pause QEMU only if the 1235host disk is full; report the error to the guest otherwise). 1236The default setting is @option{werror=enospc} and @option{rerror=report}. 1237@item copy-on-read=@var{copy-on-read} 1238@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 1239file sectors into the image file. 1240@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 1241Specify bandwidth throttling limits in bytes per second, either for all request 1242types or for reads or writes only. Small values can lead to timeouts or hangs 1243inside the guest. A safe minimum for disks is 2 MB/s. 1244@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 1245Specify bursts in bytes per second, either for all request types or for reads 1246or writes only. Bursts allow the guest I/O to spike above the limit 1247temporarily. 1248@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 1249Specify request rate limits in requests per second, either for all request 1250types or for reads or writes only. 1251@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 1252Specify bursts in requests per second, either for all request types or for reads 1253or writes only. Bursts allow the guest I/O to spike above the limit 1254temporarily. 1255@item iops_size=@var{is} 1256Let every @var{is} bytes of a request count as a new request for iops 1257throttling purposes. Use this option to prevent guests from circumventing iops 1258limits by sending fewer but larger requests. 1259@item group=@var{g} 1260Join a throttling quota group with given name @var{g}. All drives that are 1261members of the same group are accounted for together. Use this option to 1262prevent guests from circumventing throttling limits by using many small disks 1263instead of a single larger disk. 1264@end table 1265 1266By default, the @option{cache.writeback=on} mode is used. It will report data 1267writes as completed as soon as the data is present in the host page cache. 1268This is safe as long as your guest OS makes sure to correctly flush disk caches 1269where needed. If your guest OS does not handle volatile disk write caches 1270correctly and your host crashes or loses power, then the guest may experience 1271data corruption. 1272 1273For such guests, you should consider using @option{cache.writeback=off}. This 1274means that the host page cache will be used to read and write data, but write 1275notification will be sent to the guest only after QEMU has made sure to flush 1276each write to the disk. Be aware that this has a major impact on performance. 1277 1278When using the @option{-snapshot} option, unsafe caching is always used. 1279 1280Copy-on-read avoids accessing the same backing file sectors repeatedly and is 1281useful when the backing file is over a slow network. By default copy-on-read 1282is off. 1283 1284Instead of @option{-cdrom} you can use: 1285@example 1286@value{qemu_system} -drive file=file,index=2,media=cdrom 1287@end example 1288 1289Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 1290use: 1291@example 1292@value{qemu_system} -drive file=file,index=0,media=disk 1293@value{qemu_system} -drive file=file,index=1,media=disk 1294@value{qemu_system} -drive file=file,index=2,media=disk 1295@value{qemu_system} -drive file=file,index=3,media=disk 1296@end example 1297 1298You can open an image using pre-opened file descriptors from an fd set: 1299@example 1300@value{qemu_system} \ 1301 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 1302 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 1303 -drive file=/dev/fdset/2,index=0,media=disk 1304@end example 1305 1306You can connect a CDROM to the slave of ide0: 1307@example 1308@value{qemu_system_x86} -drive file=file,if=ide,index=1,media=cdrom 1309@end example 1310 1311If you don't specify the "file=" argument, you define an empty drive: 1312@example 1313@value{qemu_system_x86} -drive if=ide,index=1,media=cdrom 1314@end example 1315 1316Instead of @option{-fda}, @option{-fdb}, you can use: 1317@example 1318@value{qemu_system_x86} -drive file=file,index=0,if=floppy 1319@value{qemu_system_x86} -drive file=file,index=1,if=floppy 1320@end example 1321 1322By default, @var{interface} is "ide" and @var{index} is automatically 1323incremented: 1324@example 1325@value{qemu_system_x86} -drive file=a -drive file=b" 1326@end example 1327is interpreted like: 1328@example 1329@value{qemu_system_x86} -hda a -hdb b 1330@end example 1331ETEXI 1332 1333DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1334 "-mtdblock file use 'file' as on-board Flash memory image\n", 1335 QEMU_ARCH_ALL) 1336STEXI 1337@item -mtdblock @var{file} 1338@findex -mtdblock 1339Use @var{file} as on-board Flash memory image. 1340ETEXI 1341 1342DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1343 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1344STEXI 1345@item -sd @var{file} 1346@findex -sd 1347Use @var{file} as SecureDigital card image. 1348ETEXI 1349 1350DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1351 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1352STEXI 1353@item -pflash @var{file} 1354@findex -pflash 1355Use @var{file} as a parallel flash image. 1356ETEXI 1357 1358DEF("snapshot", 0, QEMU_OPTION_snapshot, 1359 "-snapshot write to temporary files instead of disk image files\n", 1360 QEMU_ARCH_ALL) 1361STEXI 1362@item -snapshot 1363@findex -snapshot 1364Write to temporary files instead of disk image files. In this case, 1365the raw disk image you use is not written back. You can however force 1366the write back by pressing @key{C-a s} (@pxref{disk_images}). 1367ETEXI 1368 1369DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1370 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1371 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1372 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1373 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1374 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1375 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1376 " [[,throttling.iops-size=is]]\n" 1377 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1378 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1379 "-fsdev synth,id=id\n", 1380 QEMU_ARCH_ALL) 1381 1382STEXI 1383 1384@item -fsdev local,id=@var{id},path=@var{path},security_model=@var{security_model} [,writeout=@var{writeout}][,readonly][,fmode=@var{fmode}][,dmode=@var{dmode}] [,throttling.@var{option}=@var{value}[,throttling.@var{option}=@var{value}[,...]]] 1385@itemx -fsdev proxy,id=@var{id},socket=@var{socket}[,writeout=@var{writeout}][,readonly] 1386@itemx -fsdev proxy,id=@var{id},sock_fd=@var{sock_fd}[,writeout=@var{writeout}][,readonly] 1387@itemx -fsdev synth,id=@var{id}[,readonly] 1388@findex -fsdev 1389Define a new file system device. Valid options are: 1390@table @option 1391@item local 1392Accesses to the filesystem are done by QEMU. 1393@item proxy 1394Accesses to the filesystem are done by virtfs-proxy-helper(1). 1395@item synth 1396Synthetic filesystem, only used by QTests. 1397@item id=@var{id} 1398Specifies identifier for this device. 1399@item path=@var{path} 1400Specifies the export path for the file system device. Files under 1401this path will be available to the 9p client on the guest. 1402@item security_model=@var{security_model} 1403Specifies the security model to be used for this export path. 1404Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1405In "passthrough" security model, files are stored using the same 1406credentials as they are created on the guest. This requires QEMU 1407to run as root. In "mapped-xattr" security model, some of the file 1408attributes like uid, gid, mode bits and link target are stored as 1409file attributes. For "mapped-file" these attributes are stored in the 1410hidden .virtfs_metadata directory. Directories exported by this security model cannot 1411interact with other unix tools. "none" security model is same as 1412passthrough except the sever won't report failures if it fails to 1413set file attributes like ownership. Security model is mandatory 1414only for local fsdriver. Other fsdrivers (like proxy) don't take 1415security model as a parameter. 1416@item writeout=@var{writeout} 1417This is an optional argument. The only supported value is "immediate". 1418This means that host page cache will be used to read and write data but 1419write notification will be sent to the guest only when the data has been 1420reported as written by the storage subsystem. 1421@item readonly 1422Enables exporting 9p share as a readonly mount for guests. By default 1423read-write access is given. 1424@item socket=@var{socket} 1425Enables proxy filesystem driver to use passed socket file for communicating 1426with virtfs-proxy-helper(1). 1427@item sock_fd=@var{sock_fd} 1428Enables proxy filesystem driver to use passed socket descriptor for 1429communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1430will create socketpair and pass one of the fds as sock_fd. 1431@item fmode=@var{fmode} 1432Specifies the default mode for newly created files on the host. Works only 1433with security models "mapped-xattr" and "mapped-file". 1434@item dmode=@var{dmode} 1435Specifies the default mode for newly created directories on the host. Works 1436only with security models "mapped-xattr" and "mapped-file". 1437@item throttling.bps-total=@var{b},throttling.bps-read=@var{r},throttling.bps-write=@var{w} 1438Specify bandwidth throttling limits in bytes per second, either for all request 1439types or for reads or writes only. 1440@item throttling.bps-total-max=@var{bm},bps-read-max=@var{rm},bps-write-max=@var{wm} 1441Specify bursts in bytes per second, either for all request types or for reads 1442or writes only. Bursts allow the guest I/O to spike above the limit 1443temporarily. 1444@item throttling.iops-total=@var{i},throttling.iops-read=@var{r}, throttling.iops-write=@var{w} 1445Specify request rate limits in requests per second, either for all request 1446types or for reads or writes only. 1447@item throttling.iops-total-max=@var{im},throttling.iops-read-max=@var{irm}, throttling.iops-write-max=@var{iwm} 1448Specify bursts in requests per second, either for all request types or for reads 1449or writes only. Bursts allow the guest I/O to spike above the limit temporarily. 1450@item throttling.iops-size=@var{is} 1451Let every @var{is} bytes of a request count as a new request for iops 1452throttling purposes. 1453@end table 1454 1455-fsdev option is used along with -device driver "virtio-9p-...". 1456@item -device virtio-9p-@var{type},fsdev=@var{id},mount_tag=@var{mount_tag} 1457Options for virtio-9p-... driver are: 1458@table @option 1459@item @var{type} 1460Specifies the variant to be used. Supported values are "pci", "ccw" or "device", 1461depending on the machine type. 1462@item fsdev=@var{id} 1463Specifies the id value specified along with -fsdev option. 1464@item mount_tag=@var{mount_tag} 1465Specifies the tag name to be used by the guest to mount this export point. 1466@end table 1467 1468ETEXI 1469 1470DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1471 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1472 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1473 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1474 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1475 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1476 QEMU_ARCH_ALL) 1477 1478STEXI 1479 1480@item -virtfs local,path=@var{path},mount_tag=@var{mount_tag} ,security_model=@var{security_model}[,writeout=@var{writeout}][,readonly] [,fmode=@var{fmode}][,dmode=@var{dmode}][,multidevs=@var{multidevs}] 1481@itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1482@itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1483@itemx -virtfs synth,mount_tag=@var{mount_tag} 1484@findex -virtfs 1485 1486Define a new filesystem device and expose it to the guest using a virtio-9p-device. The general form of a Virtual File system pass-through options are: 1487@table @option 1488@item local 1489Accesses to the filesystem are done by QEMU. 1490@item proxy 1491Accesses to the filesystem are done by virtfs-proxy-helper(1). 1492@item synth 1493Synthetic filesystem, only used by QTests. 1494@item id=@var{id} 1495Specifies identifier for the filesystem device 1496@item path=@var{path} 1497Specifies the export path for the file system device. Files under 1498this path will be available to the 9p client on the guest. 1499@item security_model=@var{security_model} 1500Specifies the security model to be used for this export path. 1501Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1502In "passthrough" security model, files are stored using the same 1503credentials as they are created on the guest. This requires QEMU 1504to run as root. In "mapped-xattr" security model, some of the file 1505attributes like uid, gid, mode bits and link target are stored as 1506file attributes. For "mapped-file" these attributes are stored in the 1507hidden .virtfs_metadata directory. Directories exported by this security model cannot 1508interact with other unix tools. "none" security model is same as 1509passthrough except the sever won't report failures if it fails to 1510set file attributes like ownership. Security model is mandatory only 1511for local fsdriver. Other fsdrivers (like proxy) don't take security 1512model as a parameter. 1513@item writeout=@var{writeout} 1514This is an optional argument. The only supported value is "immediate". 1515This means that host page cache will be used to read and write data but 1516write notification will be sent to the guest only when the data has been 1517reported as written by the storage subsystem. 1518@item readonly 1519Enables exporting 9p share as a readonly mount for guests. By default 1520read-write access is given. 1521@item socket=@var{socket} 1522Enables proxy filesystem driver to use passed socket file for 1523communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1524will create socketpair and pass one of the fds as sock_fd. 1525@item sock_fd 1526Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1527descriptor for interfacing with virtfs-proxy-helper(1). 1528@item fmode=@var{fmode} 1529Specifies the default mode for newly created files on the host. Works only 1530with security models "mapped-xattr" and "mapped-file". 1531@item dmode=@var{dmode} 1532Specifies the default mode for newly created directories on the host. Works 1533only with security models "mapped-xattr" and "mapped-file". 1534@item mount_tag=@var{mount_tag} 1535Specifies the tag name to be used by the guest to mount this export point. 1536@item multidevs=@var{multidevs} 1537Specifies how to deal with multiple devices being shared with a 9p export. 1538Supported behaviours are either "remap", "forbid" or "warn". The latter is 1539the default behaviour on which virtfs 9p expects only one device to be 1540shared with the same export, and if more than one device is shared and 1541accessed via the same 9p export then only a warning message is logged 1542(once) by qemu on host side. In order to avoid file ID collisions on guest 1543you should either create a separate virtfs export for each device to be 1544shared with guests (recommended way) or you might use "remap" instead which 1545allows you to share multiple devices with only one export instead, which is 1546achieved by remapping the original inode numbers from host to guest in a 1547way that would prevent such collisions. Remapping inodes in such use cases 1548is required because the original device IDs from host are never passed and 1549exposed on guest. Instead all files of an export shared with virtfs always 1550share the same device id on guest. So two files with identical inode 1551numbers but from actually different devices on host would otherwise cause a 1552file ID collision and hence potential misbehaviours on guest. "forbid" on 1553the other hand assumes like "warn" that only one device is shared by the 1554same export, however it will not only log a warning message but also 1555deny access to additional devices on guest. Note though that "forbid" does 1556currently not block all possible file access operations (e.g. readdir() 1557would still return entries from other devices). 1558@end table 1559ETEXI 1560 1561DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1562 "-iscsi [user=user][,password=password]\n" 1563 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1564 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1565 " [,timeout=timeout]\n" 1566 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1567 1568STEXI 1569@item -iscsi 1570@findex -iscsi 1571Configure iSCSI session parameters. 1572ETEXI 1573 1574STEXI 1575@end table 1576ETEXI 1577DEFHEADING() 1578 1579DEFHEADING(USB options:) 1580STEXI 1581@table @option 1582ETEXI 1583 1584DEF("usb", 0, QEMU_OPTION_usb, 1585 "-usb enable on-board USB host controller (if not enabled by default)\n", 1586 QEMU_ARCH_ALL) 1587STEXI 1588@item -usb 1589@findex -usb 1590Enable USB emulation on machine types with an on-board USB host controller (if 1591not enabled by default). Note that on-board USB host controllers may not 1592support USB 3.0. In this case @option{-device qemu-xhci} can be used instead 1593on machines with PCI. 1594ETEXI 1595 1596DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1597 "-usbdevice name add the host or guest USB device 'name'\n", 1598 QEMU_ARCH_ALL) 1599STEXI 1600 1601@item -usbdevice @var{devname} 1602@findex -usbdevice 1603Add the USB device @var{devname}. Note that this option is deprecated, 1604please use @code{-device usb-...} instead. @xref{usb_devices}. 1605 1606@table @option 1607 1608@item mouse 1609Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1610 1611@item tablet 1612Pointer device that uses absolute coordinates (like a touchscreen). This 1613means QEMU is able to report the mouse position without having to grab the 1614mouse. Also overrides the PS/2 mouse emulation when activated. 1615 1616@item braille 1617Braille device. This will use BrlAPI to display the braille output on a real 1618or fake device. 1619 1620@end table 1621ETEXI 1622 1623STEXI 1624@end table 1625ETEXI 1626DEFHEADING() 1627 1628DEFHEADING(Display options:) 1629STEXI 1630@table @option 1631ETEXI 1632 1633DEF("display", HAS_ARG, QEMU_OPTION_display, 1634#if defined(CONFIG_SPICE) 1635 "-display spice-app[,gl=on|off]\n" 1636#endif 1637#if defined(CONFIG_SDL) 1638 "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off]\n" 1639 " [,window_close=on|off][,gl=on|core|es|off]\n" 1640#endif 1641#if defined(CONFIG_GTK) 1642 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1643#endif 1644#if defined(CONFIG_VNC) 1645 "-display vnc=<display>[,<optargs>]\n" 1646#endif 1647#if defined(CONFIG_CURSES) 1648 "-display curses[,charset=<encoding>]\n" 1649#endif 1650#if defined(CONFIG_OPENGL) 1651 "-display egl-headless[,rendernode=<file>]\n" 1652#endif 1653 "-display none\n" 1654 " select display backend type\n" 1655 " The default display is equivalent to\n " 1656#if defined(CONFIG_GTK) 1657 "\"-display gtk\"\n" 1658#elif defined(CONFIG_SDL) 1659 "\"-display sdl\"\n" 1660#elif defined(CONFIG_COCOA) 1661 "\"-display cocoa\"\n" 1662#elif defined(CONFIG_VNC) 1663 "\"-vnc localhost:0,to=99,id=default\"\n" 1664#else 1665 "\"-display none\"\n" 1666#endif 1667 , QEMU_ARCH_ALL) 1668STEXI 1669@item -display @var{type} 1670@findex -display 1671Select type of display to use. This option is a replacement for the 1672old style -sdl/-curses/... options. Valid values for @var{type} are 1673@table @option 1674@item sdl 1675Display video output via SDL (usually in a separate graphics 1676window; see the SDL documentation for other possibilities). 1677@item curses 1678Display video output via curses. For graphics device models which 1679support a text mode, QEMU can display this output using a 1680curses/ncurses interface. Nothing is displayed when the graphics 1681device is in graphical mode or if the graphics device does not support 1682a text mode. Generally only the VGA device models support text mode. 1683The font charset used by the guest can be specified with the 1684@code{charset} option, for example @code{charset=CP850} for IBM CP850 1685encoding. The default is @code{CP437}. 1686@item none 1687Do not display video output. The guest will still see an emulated 1688graphics card, but its output will not be displayed to the QEMU 1689user. This option differs from the -nographic option in that it 1690only affects what is done with video output; -nographic also changes 1691the destination of the serial and parallel port data. 1692@item gtk 1693Display video output in a GTK window. This interface provides drop-down 1694menus and other UI elements to configure and control the VM during 1695runtime. 1696@item vnc 1697Start a VNC server on display <arg> 1698@item egl-headless 1699Offload all OpenGL operations to a local DRI device. For any graphical display, 1700this display needs to be paired with either VNC or SPICE displays. 1701@item spice-app 1702Start QEMU as a Spice server and launch the default Spice client 1703application. The Spice server will redirect the serial consoles and 1704QEMU monitors. (Since 4.0) 1705@end table 1706ETEXI 1707 1708DEF("nographic", 0, QEMU_OPTION_nographic, 1709 "-nographic disable graphical output and redirect serial I/Os to console\n", 1710 QEMU_ARCH_ALL) 1711STEXI 1712@item -nographic 1713@findex -nographic 1714Normally, if QEMU is compiled with graphical window support, it displays 1715output such as guest graphics, guest console, and the QEMU monitor in a 1716window. With this option, you can totally disable graphical output so 1717that QEMU is a simple command line application. The emulated serial port 1718is redirected on the console and muxed with the monitor (unless 1719redirected elsewhere explicitly). Therefore, you can still use QEMU to 1720debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1721switching between the console and monitor. 1722ETEXI 1723 1724DEF("curses", 0, QEMU_OPTION_curses, 1725 "-curses shorthand for -display curses\n", 1726 QEMU_ARCH_ALL) 1727STEXI 1728@item -curses 1729@findex -curses 1730Normally, if QEMU is compiled with graphical window support, it displays 1731output such as guest graphics, guest console, and the QEMU monitor in a 1732window. With this option, QEMU can display the VGA output when in text 1733mode using a curses/ncurses interface. Nothing is displayed in graphical 1734mode. 1735ETEXI 1736 1737DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1738 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1739 QEMU_ARCH_ALL) 1740STEXI 1741@item -alt-grab 1742@findex -alt-grab 1743Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1744affects the special keys (for fullscreen, monitor-mode switching, etc). 1745ETEXI 1746 1747DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1748 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1749 QEMU_ARCH_ALL) 1750STEXI 1751@item -ctrl-grab 1752@findex -ctrl-grab 1753Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1754affects the special keys (for fullscreen, monitor-mode switching, etc). 1755ETEXI 1756 1757DEF("no-quit", 0, QEMU_OPTION_no_quit, 1758 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1759STEXI 1760@item -no-quit 1761@findex -no-quit 1762Disable SDL window close capability. 1763ETEXI 1764 1765DEF("sdl", 0, QEMU_OPTION_sdl, 1766 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1767STEXI 1768@item -sdl 1769@findex -sdl 1770Enable SDL. 1771ETEXI 1772 1773DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1774 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1775 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1776 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1777 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1778 " [,tls-ciphers=<list>]\n" 1779 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1780 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1781 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1782 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1783 " [,jpeg-wan-compression=[auto|never|always]]\n" 1784 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1785 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1786 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1787 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1788 " [,gl=[on|off]][,rendernode=<file>]\n" 1789 " enable spice\n" 1790 " at least one of {port, tls-port} is mandatory\n", 1791 QEMU_ARCH_ALL) 1792STEXI 1793@item -spice @var{option}[,@var{option}[,...]] 1794@findex -spice 1795Enable the spice remote desktop protocol. Valid options are 1796 1797@table @option 1798 1799@item port=<nr> 1800Set the TCP port spice is listening on for plaintext channels. 1801 1802@item addr=<addr> 1803Set the IP address spice is listening on. Default is any address. 1804 1805@item ipv4 1806@itemx ipv6 1807@itemx unix 1808Force using the specified IP version. 1809 1810@item password=<secret> 1811Set the password you need to authenticate. 1812 1813@item sasl 1814Require that the client use SASL to authenticate with the spice. 1815The exact choice of authentication method used is controlled from the 1816system / user's SASL configuration file for the 'qemu' service. This 1817is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1818unprivileged user, an environment variable SASL_CONF_PATH can be used 1819to make it search alternate locations for the service config. 1820While some SASL auth methods can also provide data encryption (eg GSSAPI), 1821it is recommended that SASL always be combined with the 'tls' and 1822'x509' settings to enable use of SSL and server certificates. This 1823ensures a data encryption preventing compromise of authentication 1824credentials. 1825 1826@item disable-ticketing 1827Allow client connects without authentication. 1828 1829@item disable-copy-paste 1830Disable copy paste between the client and the guest. 1831 1832@item disable-agent-file-xfer 1833Disable spice-vdagent based file-xfer between the client and the guest. 1834 1835@item tls-port=<nr> 1836Set the TCP port spice is listening on for encrypted channels. 1837 1838@item x509-dir=<dir> 1839Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1840 1841@item x509-key-file=<file> 1842@itemx x509-key-password=<file> 1843@itemx x509-cert-file=<file> 1844@itemx x509-cacert-file=<file> 1845@itemx x509-dh-key-file=<file> 1846The x509 file names can also be configured individually. 1847 1848@item tls-ciphers=<list> 1849Specify which ciphers to use. 1850 1851@item tls-channel=[main|display|cursor|inputs|record|playback] 1852@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1853Force specific channel to be used with or without TLS encryption. The 1854options can be specified multiple times to configure multiple 1855channels. The special name "default" can be used to set the default 1856mode. For channels which are not explicitly forced into one mode the 1857spice client is allowed to pick tls/plaintext as he pleases. 1858 1859@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1860Configure image compression (lossless). 1861Default is auto_glz. 1862 1863@item jpeg-wan-compression=[auto|never|always] 1864@itemx zlib-glz-wan-compression=[auto|never|always] 1865Configure wan image compression (lossy for slow links). 1866Default is auto. 1867 1868@item streaming-video=[off|all|filter] 1869Configure video stream detection. Default is off. 1870 1871@item agent-mouse=[on|off] 1872Enable/disable passing mouse events via vdagent. Default is on. 1873 1874@item playback-compression=[on|off] 1875Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1876 1877@item seamless-migration=[on|off] 1878Enable/disable spice seamless migration. Default is off. 1879 1880@item gl=[on|off] 1881Enable/disable OpenGL context. Default is off. 1882 1883@item rendernode=<file> 1884DRM render node for OpenGL rendering. If not specified, it will pick 1885the first available. (Since 2.9) 1886 1887@end table 1888ETEXI 1889 1890DEF("portrait", 0, QEMU_OPTION_portrait, 1891 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1892 QEMU_ARCH_ALL) 1893STEXI 1894@item -portrait 1895@findex -portrait 1896Rotate graphical output 90 deg left (only PXA LCD). 1897ETEXI 1898 1899DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1900 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1901 QEMU_ARCH_ALL) 1902STEXI 1903@item -rotate @var{deg} 1904@findex -rotate 1905Rotate graphical output some deg left (only PXA LCD). 1906ETEXI 1907 1908DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1909 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1910 " select video card type\n", QEMU_ARCH_ALL) 1911STEXI 1912@item -vga @var{type} 1913@findex -vga 1914Select type of VGA card to emulate. Valid values for @var{type} are 1915@table @option 1916@item cirrus 1917Cirrus Logic GD5446 Video card. All Windows versions starting from 1918Windows 95 should recognize and use this graphic card. For optimal 1919performances, use 16 bit color depth in the guest and the host OS. 1920(This card was the default before QEMU 2.2) 1921@item std 1922Standard VGA card with Bochs VBE extensions. If your guest OS 1923supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1924to use high resolution modes (>= 1280x1024x16) then you should use 1925this option. (This card is the default since QEMU 2.2) 1926@item vmware 1927VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1928recent XFree86/XOrg server or Windows guest with a driver for this 1929card. 1930@item qxl 1931QXL paravirtual graphic card. It is VGA compatible (including VESA 19322.0 VBE support). Works best with qxl guest drivers installed though. 1933Recommended choice when using the spice protocol. 1934@item tcx 1935(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1936sun4m machines and offers both 8-bit and 24-bit colour depths at a 1937fixed resolution of 1024x768. 1938@item cg3 1939(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1940for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1941resolutions aimed at people wishing to run older Solaris versions. 1942@item virtio 1943Virtio VGA card. 1944@item none 1945Disable VGA card. 1946@end table 1947ETEXI 1948 1949DEF("full-screen", 0, QEMU_OPTION_full_screen, 1950 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1951STEXI 1952@item -full-screen 1953@findex -full-screen 1954Start in full screen. 1955ETEXI 1956 1957DEF("g", 1, QEMU_OPTION_g , 1958 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1959 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 1960STEXI 1961@item -g @var{width}x@var{height}[x@var{depth}] 1962@findex -g 1963Set the initial graphical resolution and depth (PPC, SPARC only). 1964ETEXI 1965 1966DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1967 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1968STEXI 1969@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1970@findex -vnc 1971Normally, if QEMU is compiled with graphical window support, it displays 1972output such as guest graphics, guest console, and the QEMU monitor in a 1973window. With this option, you can have QEMU listen on VNC display 1974@var{display} and redirect the VGA display over the VNC session. It is 1975very useful to enable the usb tablet device when using this option 1976(option @option{-device usb-tablet}). When using the VNC display, you 1977must use the @option{-k} parameter to set the keyboard layout if you are 1978not using en-us. Valid syntax for the @var{display} is 1979 1980@table @option 1981 1982@item to=@var{L} 1983 1984With this option, QEMU will try next available VNC @var{display}s, until the 1985number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1986available, e.g. port 5900+@var{display} is already used by another 1987application. By default, to=0. 1988 1989@item @var{host}:@var{d} 1990 1991TCP connections will only be allowed from @var{host} on display @var{d}. 1992By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1993be omitted in which case the server will accept connections from any host. 1994 1995@item unix:@var{path} 1996 1997Connections will be allowed over UNIX domain sockets where @var{path} is the 1998location of a unix socket to listen for connections on. 1999 2000@item none 2001 2002VNC is initialized but not started. The monitor @code{change} command 2003can be used to later start the VNC server. 2004 2005@end table 2006 2007Following the @var{display} value there may be one or more @var{option} flags 2008separated by commas. Valid options are 2009 2010@table @option 2011 2012@item reverse 2013 2014Connect to a listening VNC client via a ``reverse'' connection. The 2015client is specified by the @var{display}. For reverse network 2016connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 2017is a TCP port number, not a display number. 2018 2019@item websocket 2020 2021Opens an additional TCP listening port dedicated to VNC Websocket connections. 2022If a bare @var{websocket} option is given, the Websocket port is 20235700+@var{display}. An alternative port can be specified with the 2024syntax @code{websocket}=@var{port}. 2025 2026If @var{host} is specified connections will only be allowed from this host. 2027It is possible to control the websocket listen address independently, using 2028the syntax @code{websocket}=@var{host}:@var{port}. 2029 2030If no TLS credentials are provided, the websocket connection runs in 2031unencrypted mode. If TLS credentials are provided, the websocket connection 2032requires encrypted client connections. 2033 2034@item password 2035 2036Require that password based authentication is used for client connections. 2037 2038The password must be set separately using the @code{set_password} command in 2039the @ref{pcsys_monitor}. The syntax to change your password is: 2040@code{set_password <protocol> <password>} where <protocol> could be either 2041"vnc" or "spice". 2042 2043If you would like to change <protocol> password expiration, you should use 2044@code{expire_password <protocol> <expiration-time>} where expiration time could 2045be one of the following options: now, never, +seconds or UNIX time of 2046expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 2047to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 2048date and time). 2049 2050You can also use keywords "now" or "never" for the expiration time to 2051allow <protocol> password to expire immediately or never expire. 2052 2053@item tls-creds=@var{ID} 2054 2055Provides the ID of a set of TLS credentials to use to secure the 2056VNC server. They will apply to both the normal VNC server socket 2057and the websocket socket (if enabled). Setting TLS credentials 2058will cause the VNC server socket to enable the VeNCrypt auth 2059mechanism. The credentials should have been previously created 2060using the @option{-object tls-creds} argument. 2061 2062@item tls-authz=@var{ID} 2063 2064Provides the ID of the QAuthZ authorization object against which 2065the client's x509 distinguished name will validated. This object is 2066only resolved at time of use, so can be deleted and recreated on the 2067fly while the VNC server is active. If missing, it will default 2068to denying access. 2069 2070@item sasl 2071 2072Require that the client use SASL to authenticate with the VNC server. 2073The exact choice of authentication method used is controlled from the 2074system / user's SASL configuration file for the 'qemu' service. This 2075is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 2076unprivileged user, an environment variable SASL_CONF_PATH can be used 2077to make it search alternate locations for the service config. 2078While some SASL auth methods can also provide data encryption (eg GSSAPI), 2079it is recommended that SASL always be combined with the 'tls' and 2080'x509' settings to enable use of SSL and server certificates. This 2081ensures a data encryption preventing compromise of authentication 2082credentials. See the @ref{vnc_security} section for details on using 2083SASL authentication. 2084 2085@item sasl-authz=@var{ID} 2086 2087Provides the ID of the QAuthZ authorization object against which 2088the client's SASL username will validated. This object is 2089only resolved at time of use, so can be deleted and recreated on the 2090fly while the VNC server is active. If missing, it will default 2091to denying access. 2092 2093@item acl 2094 2095Legacy method for enabling authorization of clients against the 2096x509 distinguished name and SASL username. It results in the creation 2097of two @code{authz-list} objects with IDs of @code{vnc.username} and 2098@code{vnc.x509dname}. The rules for these objects must be configured 2099with the HMP ACL commands. 2100 2101This option is deprecated and should no longer be used. The new 2102@option{sasl-authz} and @option{tls-authz} options are a 2103replacement. 2104 2105@item lossy 2106 2107Enable lossy compression methods (gradient, JPEG, ...). If this 2108option is set, VNC client may receive lossy framebuffer updates 2109depending on its encoding settings. Enabling this option can save 2110a lot of bandwidth at the expense of quality. 2111 2112@item non-adaptive 2113 2114Disable adaptive encodings. Adaptive encodings are enabled by default. 2115An adaptive encoding will try to detect frequently updated screen regions, 2116and send updates in these regions using a lossy encoding (like JPEG). 2117This can be really helpful to save bandwidth when playing videos. Disabling 2118adaptive encodings restores the original static behavior of encodings 2119like Tight. 2120 2121@item share=[allow-exclusive|force-shared|ignore] 2122 2123Set display sharing policy. 'allow-exclusive' allows clients to ask 2124for exclusive access. As suggested by the rfb spec this is 2125implemented by dropping other connections. Connecting multiple 2126clients in parallel requires all clients asking for a shared session 2127(vncviewer: -shared switch). This is the default. 'force-shared' 2128disables exclusive client access. Useful for shared desktop sessions, 2129where you don't want someone forgetting specify -shared disconnect 2130everybody else. 'ignore' completely ignores the shared flag and 2131allows everybody connect unconditionally. Doesn't conform to the rfb 2132spec but is traditional QEMU behavior. 2133 2134@item key-delay-ms 2135 2136Set keyboard delay, for key down and key up events, in milliseconds. 2137Default is 10. Keyboards are low-bandwidth devices, so this slowdown 2138can help the device and guest to keep up and not lose events in case 2139events are arriving in bulk. Possible causes for the latter are flaky 2140network connections, or scripts for automated testing. 2141 2142@item audiodev=@var{audiodev} 2143 2144Use the specified @var{audiodev} when the VNC client requests audio 2145transmission. When not using an -audiodev argument, this option must 2146be omitted, otherwise is must be present and specify a valid audiodev. 2147 2148@end table 2149ETEXI 2150 2151STEXI 2152@end table 2153ETEXI 2154ARCHHEADING(, QEMU_ARCH_I386) 2155 2156ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2157STEXI 2158@table @option 2159ETEXI 2160 2161DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2162 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2163 QEMU_ARCH_I386) 2164STEXI 2165@item -win2k-hack 2166@findex -win2k-hack 2167Use it when installing Windows 2000 to avoid a disk full bug. After 2168Windows 2000 is installed, you no longer need this option (this option 2169slows down the IDE transfers). 2170ETEXI 2171 2172DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2173 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2174 QEMU_ARCH_I386) 2175STEXI 2176@item -no-fd-bootchk 2177@findex -no-fd-bootchk 2178Disable boot signature checking for floppy disks in BIOS. May 2179be needed to boot from old floppy disks. 2180ETEXI 2181 2182DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2183 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2184STEXI 2185@item -no-acpi 2186@findex -no-acpi 2187Disable ACPI (Advanced Configuration and Power Interface) support. Use 2188it if your guest OS complains about ACPI problems (PC target machine 2189only). 2190ETEXI 2191 2192DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2193 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2194STEXI 2195@item -no-hpet 2196@findex -no-hpet 2197Disable HPET support. 2198ETEXI 2199 2200DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2201 "-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" 2202 " ACPI table description\n", QEMU_ARCH_I386) 2203STEXI 2204@item -acpitable [sig=@var{str}][,rev=@var{n}][,oem_id=@var{str}][,oem_table_id=@var{str}][,oem_rev=@var{n}] [,asl_compiler_id=@var{str}][,asl_compiler_rev=@var{n}][,data=@var{file1}[:@var{file2}]...] 2205@findex -acpitable 2206Add ACPI table with specified header fields and context from specified files. 2207For file=, take whole ACPI table from the specified files, including all 2208ACPI headers (possible overridden by other options). 2209For data=, only data 2210portion of the table is used, all header information is specified in the 2211command line. 2212If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2213fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2214to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2215spec. 2216ETEXI 2217 2218DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2219 "-smbios file=binary\n" 2220 " load SMBIOS entry from binary file\n" 2221 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2222 " [,uefi=on|off]\n" 2223 " specify SMBIOS type 0 fields\n" 2224 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2225 " [,uuid=uuid][,sku=str][,family=str]\n" 2226 " specify SMBIOS type 1 fields\n" 2227 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2228 " [,asset=str][,location=str]\n" 2229 " specify SMBIOS type 2 fields\n" 2230 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2231 " [,sku=str]\n" 2232 " specify SMBIOS type 3 fields\n" 2233 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2234 " [,asset=str][,part=str]\n" 2235 " specify SMBIOS type 4 fields\n" 2236 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2237 " [,asset=str][,part=str][,speed=%d]\n" 2238 " specify SMBIOS type 17 fields\n", 2239 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2240STEXI 2241@item -smbios file=@var{binary} 2242@findex -smbios 2243Load SMBIOS entry from binary file. 2244 2245@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2246Specify SMBIOS type 0 fields 2247 2248@item -smbios type=1[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,uuid=@var{uuid}][,sku=@var{str}][,family=@var{str}] 2249Specify SMBIOS type 1 fields 2250 2251@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}] 2252Specify SMBIOS type 2 fields 2253 2254@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2255Specify SMBIOS type 3 fields 2256 2257@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2258Specify SMBIOS type 4 fields 2259 2260@item -smbios type=17[,loc_pfx=@var{str}][,bank=@var{str}][,manufacturer=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}][,speed=@var{%d}] 2261Specify SMBIOS type 17 fields 2262ETEXI 2263 2264STEXI 2265@end table 2266ETEXI 2267DEFHEADING() 2268 2269DEFHEADING(Network options:) 2270STEXI 2271@table @option 2272ETEXI 2273 2274DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2275#ifdef CONFIG_SLIRP 2276 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2277 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2278 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2279 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2280 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2281#ifndef _WIN32 2282 "[,smb=dir[,smbserver=addr]]\n" 2283#endif 2284 " configure a user mode network backend with ID 'str',\n" 2285 " its DHCP server and optional services\n" 2286#endif 2287#ifdef _WIN32 2288 "-netdev tap,id=str,ifname=name\n" 2289 " configure a host TAP network backend with ID 'str'\n" 2290#else 2291 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2292 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2293 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2294 " [,poll-us=n]\n" 2295 " configure a host TAP network backend with ID 'str'\n" 2296 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2297 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2298 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2299 " to deconfigure it\n" 2300 " use '[down]script=no' to disable script execution\n" 2301 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2302 " configure it\n" 2303 " use 'fd=h' to connect to an already opened TAP interface\n" 2304 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2305 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2306 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2307 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2308 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2309 " use vhost=on to enable experimental in kernel accelerator\n" 2310 " (only has effect for virtio guests which use MSIX)\n" 2311 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2312 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2313 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2314 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2315 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2316 " spent on busy polling for vhost net\n" 2317 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2318 " configure a host TAP network backend with ID 'str' that is\n" 2319 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2320 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2321#endif 2322#ifdef __linux__ 2323 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2324 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2325 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2326 " [,rxcookie=rxcookie][,offset=offset]\n" 2327 " configure a network backend with ID 'str' connected to\n" 2328 " an Ethernet over L2TPv3 pseudowire.\n" 2329 " Linux kernel 3.3+ as well as most routers can talk\n" 2330 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2331 " VM to a router and even VM to Host. It is a nearly-universal\n" 2332 " standard (RFC3391). Note - this implementation uses static\n" 2333 " pre-configured tunnels (same as the Linux kernel).\n" 2334 " use 'src=' to specify source address\n" 2335 " use 'dst=' to specify destination address\n" 2336 " use 'udp=on' to specify udp encapsulation\n" 2337 " use 'srcport=' to specify source udp port\n" 2338 " use 'dstport=' to specify destination udp port\n" 2339 " use 'ipv6=on' to force v6\n" 2340 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2341 " well as a weak security measure\n" 2342 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2343 " use 'txcookie=0x012345678' to specify a txcookie\n" 2344 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2345 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2346 " use 'pincounter=on' to work around broken counter handling in peer\n" 2347 " use 'offset=X' to add an extra offset between header and data\n" 2348#endif 2349 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2350 " configure a network backend to connect to another network\n" 2351 " using a socket connection\n" 2352 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2353 " configure a network backend to connect to a multicast maddr and port\n" 2354 " use 'localaddr=addr' to specify the host address to send packets from\n" 2355 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2356 " configure a network backend to connect to another network\n" 2357 " using an UDP tunnel\n" 2358#ifdef CONFIG_VDE 2359 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2360 " configure a network backend to connect to port 'n' of a vde switch\n" 2361 " running on host and listening for incoming connections on 'socketpath'.\n" 2362 " Use group 'groupname' and mode 'octalmode' to change default\n" 2363 " ownership and permissions for communication port.\n" 2364#endif 2365#ifdef CONFIG_NETMAP 2366 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2367 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2368 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2369 " netmap device, defaults to '/dev/netmap')\n" 2370#endif 2371#ifdef CONFIG_POSIX 2372 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2373 " configure a vhost-user network, backed by a chardev 'dev'\n" 2374#endif 2375 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2376 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2377DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2378 "-nic [tap|bridge|" 2379#ifdef CONFIG_SLIRP 2380 "user|" 2381#endif 2382#ifdef __linux__ 2383 "l2tpv3|" 2384#endif 2385#ifdef CONFIG_VDE 2386 "vde|" 2387#endif 2388#ifdef CONFIG_NETMAP 2389 "netmap|" 2390#endif 2391#ifdef CONFIG_POSIX 2392 "vhost-user|" 2393#endif 2394 "socket][,option][,...][mac=macaddr]\n" 2395 " initialize an on-board / default host NIC (using MAC address\n" 2396 " macaddr) and connect it to the given host network backend\n" 2397 "-nic none use it alone to have zero network devices (the default is to\n" 2398 " provided a 'user' network connection)\n", 2399 QEMU_ARCH_ALL) 2400DEF("net", HAS_ARG, QEMU_OPTION_net, 2401 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2402 " configure or create an on-board (or machine default) NIC and\n" 2403 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2404 "-net [" 2405#ifdef CONFIG_SLIRP 2406 "user|" 2407#endif 2408 "tap|" 2409 "bridge|" 2410#ifdef CONFIG_VDE 2411 "vde|" 2412#endif 2413#ifdef CONFIG_NETMAP 2414 "netmap|" 2415#endif 2416 "socket][,option][,option][,...]\n" 2417 " old way to initialize a host network interface\n" 2418 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2419STEXI 2420@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2421@findex -nic 2422This option is a shortcut for configuring both the on-board (default) guest 2423NIC hardware and the host network backend in one go. The host backend options 2424are the same as with the corresponding @option{-netdev} options below. 2425The guest NIC model can be set with @option{model=@var{modelname}}. 2426Use @option{model=help} to list the available device types. 2427The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2428 2429The following two example do exactly the same, to show how @option{-nic} can 2430be used to shorten the command line length (note that the e1000 is the default 2431on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2432@example 2433@value{qemu_system} -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2434@value{qemu_system} -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2435@end example 2436 2437@item -nic none 2438Indicate that no network devices should be configured. It is used to override 2439the default configuration (default NIC with ``user'' host network backend) 2440which is activated if no other networking options are provided. 2441 2442@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2443@findex -netdev 2444Configure user mode host network backend which requires no administrator 2445privilege to run. Valid options are: 2446 2447@table @option 2448@item id=@var{id} 2449Assign symbolic name for use in monitor commands. 2450 2451@item ipv4=on|off and ipv6=on|off 2452Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2453both protocols are enabled. 2454 2455@item net=@var{addr}[/@var{mask}] 2456Set IP network address the guest will see. Optionally specify the netmask, 2457either in the form a.b.c.d or as number of valid top-most bits. Default is 245810.0.2.0/24. 2459 2460@item host=@var{addr} 2461Specify the guest-visible address of the host. Default is the 2nd IP in the 2462guest network, i.e. x.x.x.2. 2463 2464@item ipv6-net=@var{addr}[/@var{int}] 2465Set IPv6 network address the guest will see (default is fec0::/64). The 2466network prefix is given in the usual hexadecimal IPv6 address 2467notation. The prefix size is optional, and is given as the number of 2468valid top-most bits (default is 64). 2469 2470@item ipv6-host=@var{addr} 2471Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2472the guest network, i.e. xxxx::2. 2473 2474@item restrict=on|off 2475If this option is enabled, the guest will be isolated, i.e. it will not be 2476able to contact the host and no guest IP packets will be routed over the host 2477to the outside. This option does not affect any explicitly set forwarding rules. 2478 2479@item hostname=@var{name} 2480Specifies the client hostname reported by the built-in DHCP server. 2481 2482@item dhcpstart=@var{addr} 2483Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2484is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2485 2486@item dns=@var{addr} 2487Specify the guest-visible address of the virtual nameserver. The address must 2488be different from the host address. Default is the 3rd IP in the guest network, 2489i.e. x.x.x.3. 2490 2491@item ipv6-dns=@var{addr} 2492Specify the guest-visible address of the IPv6 virtual nameserver. The address 2493must be different from the host address. Default is the 3rd IP in the guest 2494network, i.e. xxxx::3. 2495 2496@item dnssearch=@var{domain} 2497Provides an entry for the domain-search list sent by the built-in 2498DHCP server. More than one domain suffix can be transmitted by specifying 2499this option multiple times. If supported, this will cause the guest to 2500automatically try to append the given domain suffix(es) in case a domain name 2501can not be resolved. 2502 2503Example: 2504@example 2505@value{qemu_system} -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2506@end example 2507 2508@item domainname=@var{domain} 2509Specifies the client domain name reported by the built-in DHCP server. 2510 2511@item tftp=@var{dir} 2512When using the user mode network stack, activate a built-in TFTP 2513server. The files in @var{dir} will be exposed as the root of a TFTP server. 2514The TFTP client on the guest must be configured in binary mode (use the command 2515@code{bin} of the Unix TFTP client). 2516 2517@item tftp-server-name=@var{name} 2518In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 251966). This can be used to advise the guest to load boot files or configurations 2520from a different server than the host address. 2521 2522@item bootfile=@var{file} 2523When using the user mode network stack, broadcast @var{file} as the BOOTP 2524filename. In conjunction with @option{tftp}, this can be used to network boot 2525a guest from a local directory. 2526 2527Example (using pxelinux): 2528@example 2529@value{qemu_system} -hda linux.img -boot n -device e1000,netdev=n1 \ 2530 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2531@end example 2532 2533@item smb=@var{dir}[,smbserver=@var{addr}] 2534When using the user mode network stack, activate a built-in SMB 2535server so that Windows OSes can access to the host files in @file{@var{dir}} 2536transparently. The IP address of the SMB server can be set to @var{addr}. By 2537default the 4th IP in the guest network is used, i.e. x.x.x.4. 2538 2539In the guest Windows OS, the line: 2540@example 254110.0.2.4 smbserver 2542@end example 2543must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2544or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2545 2546Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2547 2548Note that a SAMBA server must be installed on the host OS. 2549 2550@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2551Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2552the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2553@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2554given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2555be bound to a specific host interface. If no connection type is set, TCP is 2556used. This option can be given multiple times. 2557 2558For example, to redirect host X11 connection from screen 1 to guest 2559screen 0, use the following: 2560 2561@example 2562# on the host 2563@value{qemu_system} -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2564# this host xterm should open in the guest X11 server 2565xterm -display :1 2566@end example 2567 2568To redirect telnet connections from host port 5555 to telnet port on 2569the guest, use the following: 2570 2571@example 2572# on the host 2573@value{qemu_system} -nic user,hostfwd=tcp::5555-:23 2574telnet localhost 5555 2575@end example 2576 2577Then when you use on the host @code{telnet localhost 5555}, you 2578connect to the guest telnet server. 2579 2580@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2581@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2582Forward guest TCP connections to the IP address @var{server} on port @var{port} 2583to the character device @var{dev} or to a program executed by @var{cmd:command} 2584which gets spawned for each connection. This option can be given multiple times. 2585 2586You can either use a chardev directly and have that one used throughout QEMU's 2587lifetime, like in the following example: 2588 2589@example 2590# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2591# the guest accesses it 2592@value{qemu_system} -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2593@end example 2594 2595Or you can execute a command on every TCP connection established by the guest, 2596so that QEMU behaves similar to an inetd process for that virtual server: 2597 2598@example 2599# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2600# and connect the TCP stream to its stdin/stdout 2601@value{qemu_system} -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2602@end example 2603 2604@end table 2605 2606@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2607Configure a host TAP network backend with ID @var{id}. 2608 2609Use the network script @var{file} to configure it and the network script 2610@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2611automatically provides one. The default network configure script is 2612@file{/etc/qemu-ifup} and the default network deconfigure script is 2613@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2614to disable script execution. 2615 2616If running QEMU as an unprivileged user, use the network helper 2617@var{helper} to configure the TAP interface and attach it to the bridge. 2618The default network helper executable is @file{/path/to/qemu-bridge-helper} 2619and the default bridge device is @file{br0}. 2620 2621@option{fd}=@var{h} can be used to specify the handle of an already 2622opened host TAP interface. 2623 2624Examples: 2625 2626@example 2627#launch a QEMU instance with the default network script 2628@value{qemu_system} linux.img -nic tap 2629@end example 2630 2631@example 2632#launch a QEMU instance with two NICs, each one connected 2633#to a TAP device 2634@value{qemu_system} linux.img \ 2635 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2636 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2637@end example 2638 2639@example 2640#launch a QEMU instance with the default network helper to 2641#connect a TAP device to bridge br0 2642@value{qemu_system} linux.img -device virtio-net-pci,netdev=n1 \ 2643 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2644@end example 2645 2646@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2647Connect a host TAP network interface to a host bridge device. 2648 2649Use the network helper @var{helper} to configure the TAP interface and 2650attach it to the bridge. The default network helper executable is 2651@file{/path/to/qemu-bridge-helper} and the default bridge 2652device is @file{br0}. 2653 2654Examples: 2655 2656@example 2657#launch a QEMU instance with the default network helper to 2658#connect a TAP device to bridge br0 2659@value{qemu_system} linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2660@end example 2661 2662@example 2663#launch a QEMU instance with the default network helper to 2664#connect a TAP device to bridge qemubr0 2665@value{qemu_system} linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2666@end example 2667 2668@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2669 2670This host network backend can be used to connect the guest's network to 2671another QEMU virtual machine using a TCP socket connection. If @option{listen} 2672is specified, QEMU waits for incoming connections on @var{port} 2673(@var{host} is optional). @option{connect} is used to connect to 2674another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2675specifies an already opened TCP socket. 2676 2677Example: 2678@example 2679# launch a first QEMU instance 2680@value{qemu_system} linux.img \ 2681 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2682 -netdev socket,id=n1,listen=:1234 2683# connect the network of this instance to the network of the first instance 2684@value{qemu_system} linux.img \ 2685 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2686 -netdev socket,id=n2,connect=127.0.0.1:1234 2687@end example 2688 2689@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2690 2691Configure a socket host network backend to share the guest's network traffic 2692with another QEMU virtual machines using a UDP multicast socket, effectively 2693making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2694NOTES: 2695@enumerate 2696@item 2697Several QEMU can be running on different hosts and share same bus (assuming 2698correct multicast setup for these hosts). 2699@item 2700mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2701@url{http://user-mode-linux.sf.net}. 2702@item 2703Use @option{fd=h} to specify an already opened UDP multicast socket. 2704@end enumerate 2705 2706Example: 2707@example 2708# launch one QEMU instance 2709@value{qemu_system} linux.img \ 2710 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2711 -netdev socket,id=n1,mcast=230.0.0.1:1234 2712# launch another QEMU instance on same "bus" 2713@value{qemu_system} linux.img \ 2714 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2715 -netdev socket,id=n2,mcast=230.0.0.1:1234 2716# launch yet another QEMU instance on same "bus" 2717@value{qemu_system} linux.img \ 2718 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2719 -netdev socket,id=n3,mcast=230.0.0.1:1234 2720@end example 2721 2722Example (User Mode Linux compat.): 2723@example 2724# launch QEMU instance (note mcast address selected is UML's default) 2725@value{qemu_system} linux.img \ 2726 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2727 -netdev socket,id=n1,mcast=239.192.168.1:1102 2728# launch UML 2729/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2730@end example 2731 2732Example (send packets from host's 1.2.3.4): 2733@example 2734@value{qemu_system} linux.img \ 2735 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2736 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2737@end example 2738 2739@item -netdev l2tpv3,id=@var{id},src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}] 2740Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2741popular protocol to transport Ethernet (and other Layer 2) data frames between 2742two systems. It is present in routers, firewalls and the Linux kernel 2743(from version 3.3 onwards). 2744 2745This transport allows a VM to communicate to another VM, router or firewall directly. 2746 2747@table @option 2748@item src=@var{srcaddr} 2749 source address (mandatory) 2750@item dst=@var{dstaddr} 2751 destination address (mandatory) 2752@item udp 2753 select udp encapsulation (default is ip). 2754@item srcport=@var{srcport} 2755 source udp port. 2756@item dstport=@var{dstport} 2757 destination udp port. 2758@item ipv6 2759 force v6, otherwise defaults to v4. 2760@item rxcookie=@var{rxcookie} 2761@itemx txcookie=@var{txcookie} 2762 Cookies are a weak form of security in the l2tpv3 specification. 2763Their function is mostly to prevent misconfiguration. By default they are 32 2764bit. 2765@item cookie64 2766 Set cookie size to 64 bit instead of the default 32 2767@item counter=off 2768 Force a 'cut-down' L2TPv3 with no counter as in 2769draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2770@item pincounter=on 2771 Work around broken counter handling in peer. This may also help on 2772networks which have packet reorder. 2773@item offset=@var{offset} 2774 Add an extra offset between header and data 2775@end table 2776 2777For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2778on the remote Linux host 1.2.3.4: 2779@example 2780# Setup tunnel on linux host using raw ip as encapsulation 2781# on 1.2.3.4 2782ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2783 encap udp udp_sport 16384 udp_dport 16384 2784ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2785 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2786ifconfig vmtunnel0 mtu 1500 2787ifconfig vmtunnel0 up 2788brctl addif br-lan vmtunnel0 2789 2790 2791# on 4.3.2.1 2792# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2793 2794@value{qemu_system} linux.img -device e1000,netdev=n1 \ 2795 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2796 2797@end example 2798 2799@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2800Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2801listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2802and MODE @var{octalmode} to change default ownership and permissions for 2803communication port. This option is only available if QEMU has been compiled 2804with vde support enabled. 2805 2806Example: 2807@example 2808# launch vde switch 2809vde_switch -F -sock /tmp/myswitch 2810# launch QEMU instance 2811@value{qemu_system} linux.img -nic vde,sock=/tmp/myswitch 2812@end example 2813 2814@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2815 2816Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2817be a unix domain socket backed one. The vhost-user uses a specifically defined 2818protocol to pass vhost ioctl replacement messages to an application on the other 2819end of the socket. On non-MSIX guests, the feature can be forced with 2820@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2821be created for multiqueue vhost-user. 2822 2823Example: 2824@example 2825qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2826 -numa node,memdev=mem \ 2827 -chardev socket,id=chr0,path=/path/to/socket \ 2828 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2829 -device virtio-net-pci,netdev=net0 2830@end example 2831 2832@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2833 2834Create a hub port on the emulated hub with ID @var{hubid}. 2835 2836The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2837single netdev. Alternatively, you can also connect the hubport to another 2838netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2839 2840@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2841@findex -net 2842Legacy option to configure or create an on-board (or machine default) Network 2843Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2844the default hub), or to the netdev @var{nd}. 2845The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2846can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2847only), and a @var{name} can be assigned for use in monitor commands. 2848Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2849that the card should have; this option currently only affects virtio cards; set 2850@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2851NIC is created. QEMU can emulate several different models of network card. 2852Use @code{-net nic,model=help} for a list of available devices for your target. 2853 2854@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2855Configure a host network backend (with the options corresponding to the same 2856@option{-netdev} option) and connect it to the emulated hub 0 (the default 2857hub). Use @var{name} to specify the name of the hub port. 2858ETEXI 2859 2860STEXI 2861@end table 2862ETEXI 2863DEFHEADING() 2864 2865DEFHEADING(Character device options:) 2866 2867DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2868 "-chardev help\n" 2869 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2870 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2871 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2872 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2873 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2874 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2875 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2876 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2877 " [,logfile=PATH][,logappend=on|off]\n" 2878 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2879 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2880 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2881 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2882 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2883 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2884#ifdef _WIN32 2885 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2886 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2887#else 2888 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2889 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2890#endif 2891#ifdef CONFIG_BRLAPI 2892 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2893#endif 2894#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2895 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2896 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2897 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2898#endif 2899#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2900 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2901 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2902#endif 2903#if defined(CONFIG_SPICE) 2904 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2905 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2906#endif 2907 , QEMU_ARCH_ALL 2908) 2909 2910STEXI 2911 2912The general form of a character device option is: 2913@table @option 2914@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2915@findex -chardev 2916Backend is one of: 2917@option{null}, 2918@option{socket}, 2919@option{udp}, 2920@option{msmouse}, 2921@option{vc}, 2922@option{ringbuf}, 2923@option{file}, 2924@option{pipe}, 2925@option{console}, 2926@option{serial}, 2927@option{pty}, 2928@option{stdio}, 2929@option{braille}, 2930@option{tty}, 2931@option{parallel}, 2932@option{parport}, 2933@option{spicevmc}, 2934@option{spiceport}. 2935The specific backend will determine the applicable options. 2936 2937Use @code{-chardev help} to print all available chardev backend types. 2938 2939All devices must have an id, which can be any string up to 127 characters long. 2940It is used to uniquely identify this device in other command line directives. 2941 2942A character device may be used in multiplexing mode by multiple front-ends. 2943Specify @option{mux=on} to enable this mode. 2944A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2945backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2946If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2947create a multiplexer with your specified ID, and you can then configure multiple 2948front ends to use that chardev ID for their input/output. Up to four different 2949front ends can be connected to a single multiplexed chardev. (Without 2950multiplexing enabled, a chardev can only be used by a single front end.) 2951For instance you could use this to allow a single stdio chardev to be used by 2952two serial ports and the QEMU monitor: 2953 2954@example 2955-chardev stdio,mux=on,id=char0 \ 2956-mon chardev=char0,mode=readline \ 2957-serial chardev:char0 \ 2958-serial chardev:char0 2959@end example 2960 2961You can have more than one multiplexer in a system configuration; for instance 2962you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2963multiplexed between the QEMU monitor and a parallel port: 2964 2965@example 2966-chardev stdio,mux=on,id=char0 \ 2967-mon chardev=char0,mode=readline \ 2968-parallel chardev:char0 \ 2969-chardev tcp,...,mux=on,id=char1 \ 2970-serial chardev:char1 \ 2971-serial chardev:char1 2972@end example 2973 2974When you're using a multiplexed character device, some escape sequences are 2975interpreted in the input. @xref{mux_keys, Keys in the character backend 2976multiplexer}. 2977 2978Note that some other command line options may implicitly create multiplexed 2979character backends; for instance @option{-serial mon:stdio} creates a 2980multiplexed stdio backend connected to the serial port and the QEMU monitor, 2981and @option{-nographic} also multiplexes the console and the monitor to 2982stdio. 2983 2984There is currently no support for multiplexing in the other direction 2985(where a single QEMU front end takes input and output from multiple chardevs). 2986 2987Every backend supports the @option{logfile} option, which supplies the path 2988to a file to record all data transmitted via the backend. The @option{logappend} 2989option controls whether the log file will be truncated or appended to when 2990opened. 2991 2992@end table 2993 2994The available backends are: 2995 2996@table @option 2997@item -chardev null,id=@var{id} 2998A void device. This device will not emit any data, and will drop any data it 2999receives. The null backend does not take any options. 3000 3001@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,websocket][,reconnect=@var{seconds}][,tls-creds=@var{id}][,tls-authz=@var{id}] 3002 3003Create a two-way stream socket, which can be either a TCP or a unix socket. A 3004unix socket will be created if @option{path} is specified. Behaviour is 3005undefined if TCP options are specified for a unix socket. 3006 3007@option{server} specifies that the socket shall be a listening socket. 3008 3009@option{nowait} specifies that QEMU should not block waiting for a client to 3010connect to a listening socket. 3011 3012@option{telnet} specifies that traffic on the socket should interpret telnet 3013escape sequences. 3014 3015@option{websocket} specifies that the socket uses WebSocket protocol for 3016communication. 3017 3018@option{reconnect} sets the timeout for reconnecting on non-server sockets when 3019the remote end goes away. qemu will delay this many seconds and then attempt 3020to reconnect. Zero disables reconnecting, and is the default. 3021 3022@option{tls-creds} requests enablement of the TLS protocol for encryption, 3023and specifies the id of the TLS credentials to use for the handshake. The 3024credentials must be previously created with the @option{-object tls-creds} 3025argument. 3026 3027@option{tls-auth} provides the ID of the QAuthZ authorization object against 3028which the client's x509 distinguished name will be validated. This object is 3029only resolved at time of use, so can be deleted and recreated on the fly 3030while the chardev server is active. If missing, it will default to denying 3031access. 3032 3033TCP and unix socket options are given below: 3034 3035@table @option 3036 3037@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 3038 3039@option{host} for a listening socket specifies the local address to be bound. 3040For a connecting socket species the remote host to connect to. @option{host} is 3041optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 3042 3043@option{port} for a listening socket specifies the local port to be bound. For a 3044connecting socket specifies the port on the remote host to connect to. 3045@option{port} can be given as either a port number or a service name. 3046@option{port} is required. 3047 3048@option{to} is only relevant to listening sockets. If it is specified, and 3049@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 3050to and including @option{to} until it succeeds. @option{to} must be specified 3051as a port number. 3052 3053@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 3054If neither is specified the socket may use either protocol. 3055 3056@option{nodelay} disables the Nagle algorithm. 3057 3058@item unix options: path=@var{path} 3059 3060@option{path} specifies the local path of the unix socket. @option{path} is 3061required. 3062 3063@end table 3064 3065@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 3066 3067Sends all traffic from the guest to a remote host over UDP. 3068 3069@option{host} specifies the remote host to connect to. If not specified it 3070defaults to @code{localhost}. 3071 3072@option{port} specifies the port on the remote host to connect to. @option{port} 3073is required. 3074 3075@option{localaddr} specifies the local address to bind to. If not specified it 3076defaults to @code{0.0.0.0}. 3077 3078@option{localport} specifies the local port to bind to. If not specified any 3079available local port will be used. 3080 3081@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 3082If neither is specified the device may use either protocol. 3083 3084@item -chardev msmouse,id=@var{id} 3085 3086Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 3087take any options. 3088 3089@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 3090 3091Connect to a QEMU text console. @option{vc} may optionally be given a specific 3092size. 3093 3094@option{width} and @option{height} specify the width and height respectively of 3095the console, in pixels. 3096 3097@option{cols} and @option{rows} specify that the console be sized to fit a text 3098console with the given dimensions. 3099 3100@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 3101 3102Create a ring buffer with fixed size @option{size}. 3103@var{size} must be a power of two and defaults to @code{64K}. 3104 3105@item -chardev file,id=@var{id},path=@var{path} 3106 3107Log all traffic received from the guest to a file. 3108 3109@option{path} specifies the path of the file to be opened. This file will be 3110created if it does not already exist, and overwritten if it does. @option{path} 3111is required. 3112 3113@item -chardev pipe,id=@var{id},path=@var{path} 3114 3115Create a two-way connection to the guest. The behaviour differs slightly between 3116Windows hosts and other hosts: 3117 3118On Windows, a single duplex pipe will be created at 3119@file{\\.pipe\@option{path}}. 3120 3121On other hosts, 2 pipes will be created called @file{@option{path}.in} and 3122@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 3123received by the guest. Data written by the guest can be read from 3124@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 3125be present. 3126 3127@option{path} forms part of the pipe path as described above. @option{path} is 3128required. 3129 3130@item -chardev console,id=@var{id} 3131 3132Send traffic from the guest to QEMU's standard output. @option{console} does not 3133take any options. 3134 3135@option{console} is only available on Windows hosts. 3136 3137@item -chardev serial,id=@var{id},path=@option{path} 3138 3139Send traffic from the guest to a serial device on the host. 3140 3141On Unix hosts serial will actually accept any tty device, 3142not only serial lines. 3143 3144@option{path} specifies the name of the serial device to open. 3145 3146@item -chardev pty,id=@var{id} 3147 3148Create a new pseudo-terminal on the host and connect to it. @option{pty} does 3149not take any options. 3150 3151@option{pty} is not available on Windows hosts. 3152 3153@item -chardev stdio,id=@var{id}[,signal=on|off] 3154Connect to standard input and standard output of the QEMU process. 3155 3156@option{signal} controls if signals are enabled on the terminal, that includes 3157exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 3158default, use @option{signal=off} to disable it. 3159 3160@item -chardev braille,id=@var{id} 3161 3162Connect to a local BrlAPI server. @option{braille} does not take any options. 3163 3164@item -chardev tty,id=@var{id},path=@var{path} 3165 3166@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 3167DragonFlyBSD hosts. It is an alias for @option{serial}. 3168 3169@option{path} specifies the path to the tty. @option{path} is required. 3170 3171@item -chardev parallel,id=@var{id},path=@var{path} 3172@itemx -chardev parport,id=@var{id},path=@var{path} 3173 3174@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3175 3176Connect to a local parallel port. 3177 3178@option{path} specifies the path to the parallel port device. @option{path} is 3179required. 3180 3181@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3182 3183@option{spicevmc} is only available when spice support is built in. 3184 3185@option{debug} debug level for spicevmc 3186 3187@option{name} name of spice channel to connect to 3188 3189Connect to a spice virtual machine channel, such as vdiport. 3190 3191@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3192 3193@option{spiceport} is only available when spice support is built in. 3194 3195@option{debug} debug level for spicevmc 3196 3197@option{name} name of spice port to connect to 3198 3199Connect to a spice port, allowing a Spice client to handle the traffic 3200identified by a name (preferably a fqdn). 3201ETEXI 3202 3203STEXI 3204@end table 3205ETEXI 3206DEFHEADING() 3207 3208#ifdef CONFIG_TPM 3209DEFHEADING(TPM device options:) 3210 3211DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3212 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3213 " use path to provide path to a character device; default is /dev/tpm0\n" 3214 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3215 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3216 "-tpmdev emulator,id=id,chardev=dev\n" 3217 " configure the TPM device using chardev backend\n", 3218 QEMU_ARCH_ALL) 3219STEXI 3220 3221The general form of a TPM device option is: 3222@table @option 3223 3224@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3225@findex -tpmdev 3226 3227The specific backend type will determine the applicable options. 3228The @code{-tpmdev} option creates the TPM backend and requires a 3229@code{-device} option that specifies the TPM frontend interface model. 3230 3231Use @code{-tpmdev help} to print all available TPM backend types. 3232 3233@end table 3234 3235The available backends are: 3236 3237@table @option 3238 3239@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3240 3241(Linux-host only) Enable access to the host's TPM using the passthrough 3242driver. 3243 3244@option{path} specifies the path to the host's TPM device, i.e., on 3245a Linux host this would be @code{/dev/tpm0}. 3246@option{path} is optional and by default @code{/dev/tpm0} is used. 3247 3248@option{cancel-path} specifies the path to the host TPM device's sysfs 3249entry allowing for cancellation of an ongoing TPM command. 3250@option{cancel-path} is optional and by default QEMU will search for the 3251sysfs entry to use. 3252 3253Some notes about using the host's TPM with the passthrough driver: 3254 3255The TPM device accessed by the passthrough driver must not be 3256used by any other application on the host. 3257 3258Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3259the VM's firmware (BIOS/UEFI) will not be able to initialize the 3260TPM again and may therefore not show a TPM-specific menu that would 3261otherwise allow the user to configure the TPM, e.g., allow the user to 3262enable/disable or activate/deactivate the TPM. 3263Further, if TPM ownership is released from within a VM then the host's TPM 3264will get disabled and deactivated. To enable and activate the 3265TPM again afterwards, the host has to be rebooted and the user is 3266required to enter the firmware's menu to enable and activate the TPM. 3267If the TPM is left disabled and/or deactivated most TPM commands will fail. 3268 3269To create a passthrough TPM use the following two options: 3270@example 3271-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3272@end example 3273Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3274@code{tpmdev=tpm0} in the device option. 3275 3276@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3277 3278(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3279chardev backend. 3280 3281@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3282 3283To create a TPM emulator backend device with chardev socket backend: 3284@example 3285 3286-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3287 3288@end example 3289 3290ETEXI 3291 3292STEXI 3293@end table 3294ETEXI 3295DEFHEADING() 3296 3297#endif 3298 3299DEFHEADING(Linux/Multiboot boot specific:) 3300STEXI 3301 3302When using these options, you can use a given Linux or Multiboot 3303kernel without installing it in the disk image. It can be useful 3304for easier testing of various kernels. 3305 3306@table @option 3307ETEXI 3308 3309DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3310 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3311STEXI 3312@item -kernel @var{bzImage} 3313@findex -kernel 3314Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3315or in multiboot format. 3316ETEXI 3317 3318DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3319 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3320STEXI 3321@item -append @var{cmdline} 3322@findex -append 3323Use @var{cmdline} as kernel command line 3324ETEXI 3325 3326DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3327 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3328STEXI 3329@item -initrd @var{file} 3330@findex -initrd 3331Use @var{file} as initial ram disk. 3332 3333@item -initrd "@var{file1} arg=foo,@var{file2}" 3334 3335This syntax is only available with multiboot. 3336 3337Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3338first module. 3339ETEXI 3340 3341DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3342 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3343STEXI 3344@item -dtb @var{file} 3345@findex -dtb 3346Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3347on boot. 3348ETEXI 3349 3350STEXI 3351@end table 3352ETEXI 3353DEFHEADING() 3354 3355DEFHEADING(Debug/Expert options:) 3356STEXI 3357@table @option 3358ETEXI 3359 3360DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3361 "-fw_cfg [name=]<name>,file=<file>\n" 3362 " add named fw_cfg entry with contents from file\n" 3363 "-fw_cfg [name=]<name>,string=<str>\n" 3364 " add named fw_cfg entry with contents from string\n", 3365 QEMU_ARCH_ALL) 3366STEXI 3367 3368@item -fw_cfg [name=]@var{name},file=@var{file} 3369@findex -fw_cfg 3370Add named fw_cfg entry with contents from file @var{file}. 3371 3372@item -fw_cfg [name=]@var{name},string=@var{str} 3373Add named fw_cfg entry with contents from string @var{str}. 3374 3375The terminating NUL character of the contents of @var{str} will not be 3376included as part of the fw_cfg item data. To insert contents with 3377embedded NUL characters, you have to use the @var{file} parameter. 3378 3379The fw_cfg entries are passed by QEMU through to the guest. 3380 3381Example: 3382@example 3383 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3384@end example 3385creates an fw_cfg entry named opt/com.mycompany/blob with contents 3386from ./my_blob.bin. 3387 3388ETEXI 3389 3390DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3391 "-serial dev redirect the serial port to char device 'dev'\n", 3392 QEMU_ARCH_ALL) 3393STEXI 3394@item -serial @var{dev} 3395@findex -serial 3396Redirect the virtual serial port to host character device 3397@var{dev}. The default device is @code{vc} in graphical mode and 3398@code{stdio} in non graphical mode. 3399 3400This option can be used several times to simulate up to 4 serial 3401ports. 3402 3403Use @code{-serial none} to disable all serial ports. 3404 3405Available character devices are: 3406@table @option 3407@item vc[:@var{W}x@var{H}] 3408Virtual console. Optionally, a width and height can be given in pixel with 3409@example 3410vc:800x600 3411@end example 3412It is also possible to specify width or height in characters: 3413@example 3414vc:80Cx24C 3415@end example 3416@item pty 3417[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3418@item none 3419No device is allocated. 3420@item null 3421void device 3422@item chardev:@var{id} 3423Use a named character device defined with the @code{-chardev} option. 3424@item /dev/XXX 3425[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3426parameters are set according to the emulated ones. 3427@item /dev/parport@var{N} 3428[Linux only, parallel port only] Use host parallel port 3429@var{N}. Currently SPP and EPP parallel port features can be used. 3430@item file:@var{filename} 3431Write output to @var{filename}. No character can be read. 3432@item stdio 3433[Unix only] standard input/output 3434@item pipe:@var{filename} 3435name pipe @var{filename} 3436@item COM@var{n} 3437[Windows only] Use host serial port @var{n} 3438@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3439This implements UDP Net Console. 3440When @var{remote_host} or @var{src_ip} are not specified 3441they default to @code{0.0.0.0}. 3442When not using a specified @var{src_port} a random port is automatically chosen. 3443 3444If you just want a simple readonly console you can use @code{netcat} or 3445@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3446@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3447will appear in the netconsole session. 3448 3449If you plan to send characters back via netconsole or you want to stop 3450and start QEMU a lot of times, you should have QEMU use the same 3451source port each time by using something like @code{-serial 3452udp::4555@@:4556} to QEMU. Another approach is to use a patched 3453version of netcat which can listen to a TCP port and send and receive 3454characters via udp. If you have a patched version of netcat which 3455activates telnet remote echo and single char transfer, then you can 3456use the following options to set up a netcat redirector to allow 3457telnet on port 5555 to access the QEMU port. 3458@table @code 3459@item QEMU Options: 3460-serial udp::4555@@:4556 3461@item netcat options: 3462-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3463@item telnet options: 3464localhost 5555 3465@end table 3466 3467@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3468The TCP Net Console has two modes of operation. It can send the serial 3469I/O to a location or wait for a connection from a location. By default 3470the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3471the @var{server} option QEMU will wait for a client socket application 3472to connect to the port before continuing, unless the @code{nowait} 3473option was specified. The @code{nodelay} option disables the Nagle buffering 3474algorithm. The @code{reconnect} option only applies if @var{noserver} is 3475set, if the connection goes down it will attempt to reconnect at the 3476given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3477one TCP connection at a time is accepted. You can use @code{telnet} to 3478connect to the corresponding character device. 3479@table @code 3480@item Example to send tcp console to 192.168.0.2 port 4444 3481-serial tcp:192.168.0.2:4444 3482@item Example to listen and wait on port 4444 for connection 3483-serial tcp::4444,server 3484@item Example to not wait and listen on ip 192.168.0.100 port 4444 3485-serial tcp:192.168.0.100:4444,server,nowait 3486@end table 3487 3488@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3489The telnet protocol is used instead of raw tcp sockets. The options 3490work the same as if you had specified @code{-serial tcp}. The 3491difference is that the port acts like a telnet server or client using 3492telnet option negotiation. This will also allow you to send the 3493MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3494sequence. Typically in unix telnet you do it with Control-] and then 3495type "send break" followed by pressing the enter key. 3496 3497@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3498The WebSocket protocol is used instead of raw tcp socket. The port acts as 3499a WebSocket server. Client mode is not supported. 3500 3501@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3502A unix domain socket is used instead of a tcp socket. The option works the 3503same as if you had specified @code{-serial tcp} except the unix domain socket 3504@var{path} is used for connections. 3505 3506@item mon:@var{dev_string} 3507This is a special option to allow the monitor to be multiplexed onto 3508another serial port. The monitor is accessed with key sequence of 3509@key{Control-a} and then pressing @key{c}. 3510@var{dev_string} should be any one of the serial devices specified 3511above. An example to multiplex the monitor onto a telnet server 3512listening on port 4444 would be: 3513@table @code 3514@item -serial mon:telnet::4444,server,nowait 3515@end table 3516When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3517QEMU any more but will be passed to the guest instead. 3518 3519@item braille 3520Braille device. This will use BrlAPI to display the braille output on a real 3521or fake device. 3522 3523@item msmouse 3524Three button serial mouse. Configure the guest to use Microsoft protocol. 3525@end table 3526ETEXI 3527 3528DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3529 "-parallel dev redirect the parallel port to char device 'dev'\n", 3530 QEMU_ARCH_ALL) 3531STEXI 3532@item -parallel @var{dev} 3533@findex -parallel 3534Redirect the virtual parallel port to host device @var{dev} (same 3535devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3536be used to use hardware devices connected on the corresponding host 3537parallel port. 3538 3539This option can be used several times to simulate up to 3 parallel 3540ports. 3541 3542Use @code{-parallel none} to disable all parallel ports. 3543ETEXI 3544 3545DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3546 "-monitor dev redirect the monitor to char device 'dev'\n", 3547 QEMU_ARCH_ALL) 3548STEXI 3549@item -monitor @var{dev} 3550@findex -monitor 3551Redirect the monitor to host device @var{dev} (same devices as the 3552serial port). 3553The default device is @code{vc} in graphical mode and @code{stdio} in 3554non graphical mode. 3555Use @code{-monitor none} to disable the default monitor. 3556ETEXI 3557DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3558 "-qmp dev like -monitor but opens in 'control' mode\n", 3559 QEMU_ARCH_ALL) 3560STEXI 3561@item -qmp @var{dev} 3562@findex -qmp 3563Like -monitor but opens in 'control' mode. 3564ETEXI 3565DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3566 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3567 QEMU_ARCH_ALL) 3568STEXI 3569@item -qmp-pretty @var{dev} 3570@findex -qmp-pretty 3571Like -qmp but uses pretty JSON formatting. 3572ETEXI 3573 3574DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3575 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3576STEXI 3577@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3578@findex -mon 3579Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3580easing human reading and debugging. 3581ETEXI 3582 3583DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3584 "-debugcon dev redirect the debug console to char device 'dev'\n", 3585 QEMU_ARCH_ALL) 3586STEXI 3587@item -debugcon @var{dev} 3588@findex -debugcon 3589Redirect the debug console to host device @var{dev} (same devices as the 3590serial port). The debug console is an I/O port which is typically port 35910xe9; writing to that I/O port sends output to this device. 3592The default device is @code{vc} in graphical mode and @code{stdio} in 3593non graphical mode. 3594ETEXI 3595 3596DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3597 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3598STEXI 3599@item -pidfile @var{file} 3600@findex -pidfile 3601Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3602from a script. 3603ETEXI 3604 3605DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3606 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3607STEXI 3608@item -singlestep 3609@findex -singlestep 3610Run the emulation in single step mode. 3611ETEXI 3612 3613DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3614 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3615 QEMU_ARCH_ALL) 3616STEXI 3617@item --preconfig 3618@findex --preconfig 3619Pause QEMU for interactive configuration before the machine is created, 3620which allows querying and configuring properties that will affect 3621machine initialization. Use QMP command 'x-exit-preconfig' to exit 3622the preconfig state and move to the next state (i.e. run guest if -S 3623isn't used or pause the second time if -S is used). This option is 3624experimental. 3625ETEXI 3626 3627DEF("S", 0, QEMU_OPTION_S, \ 3628 "-S freeze CPU at startup (use 'c' to start execution)\n", 3629 QEMU_ARCH_ALL) 3630STEXI 3631@item -S 3632@findex -S 3633Do not start CPU at startup (you must type 'c' in the monitor). 3634ETEXI 3635 3636DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3637 "-realtime [mlock=on|off]\n" 3638 " run qemu with realtime features\n" 3639 " mlock=on|off controls mlock support (default: on)\n", 3640 QEMU_ARCH_ALL) 3641STEXI 3642@item -realtime mlock=on|off 3643@findex -realtime 3644Run qemu with realtime features. 3645mlocking qemu and guest memory can be enabled via @option{mlock=on} 3646(enabled by default). 3647ETEXI 3648 3649DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3650 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3651 " run qemu with overcommit hints\n" 3652 " mem-lock=on|off controls memory lock support (default: off)\n" 3653 " cpu-pm=on|off controls cpu power management (default: off)\n", 3654 QEMU_ARCH_ALL) 3655STEXI 3656@item -overcommit mem-lock=on|off 3657@item -overcommit cpu-pm=on|off 3658@findex -overcommit 3659Run qemu with hints about host resource overcommit. The default is 3660to assume that host overcommits all resources. 3661 3662Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3663by default). This works when host memory is not overcommitted and reduces the 3664worst-case latency for guest. This is equivalent to @option{realtime}. 3665 3666Guest ability to manage power state of host cpus (increasing latency for other 3667processes on the same host cpu, but decreasing latency for guest) can be 3668enabled via @option{cpu-pm=on} (disabled by default). This works best when 3669host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3670utilization will be incorrect, not taking into account guest idle time. 3671ETEXI 3672 3673DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3674 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3675STEXI 3676@item -gdb @var{dev} 3677@findex -gdb 3678Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3679connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3680stdio are reasonable use case. The latter is allowing to start QEMU from 3681within gdb and establish the connection via a pipe: 3682@example 3683(gdb) target remote | exec @value{qemu_system} -gdb stdio ... 3684@end example 3685ETEXI 3686 3687DEF("s", 0, QEMU_OPTION_s, \ 3688 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3689 QEMU_ARCH_ALL) 3690STEXI 3691@item -s 3692@findex -s 3693Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3694(@pxref{gdb_usage}). 3695ETEXI 3696 3697DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3698 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3699 QEMU_ARCH_ALL) 3700STEXI 3701@item -d @var{item1}[,...] 3702@findex -d 3703Enable logging of specified items. Use '-d help' for a list of log items. 3704ETEXI 3705 3706DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3707 "-D logfile output log to logfile (default stderr)\n", 3708 QEMU_ARCH_ALL) 3709STEXI 3710@item -D @var{logfile} 3711@findex -D 3712Output log in @var{logfile} instead of to stderr 3713ETEXI 3714 3715DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3716 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3717 QEMU_ARCH_ALL) 3718STEXI 3719@item -dfilter @var{range1}[,...] 3720@findex -dfilter 3721Filter debug output to that relevant to a range of target addresses. The filter 3722spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3723@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3724addresses and sizes required. For example: 3725@example 3726 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3727@end example 3728Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3729the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3730block starting at 0xffffffc00005f000. 3731ETEXI 3732 3733DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3734 "-seed number seed the pseudo-random number generator\n", 3735 QEMU_ARCH_ALL) 3736STEXI 3737@item -seed @var{number} 3738@findex -seed 3739Force the guest to use a deterministic pseudo-random number generator, seeded 3740with @var{number}. This does not affect crypto routines within the host. 3741ETEXI 3742 3743DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3744 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3745 QEMU_ARCH_ALL) 3746STEXI 3747@item -L @var{path} 3748@findex -L 3749Set the directory for the BIOS, VGA BIOS and keymaps. 3750 3751To list all the data directories, use @code{-L help}. 3752ETEXI 3753 3754DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3755 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3756STEXI 3757@item -bios @var{file} 3758@findex -bios 3759Set the filename for the BIOS. 3760ETEXI 3761 3762DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3763 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3764STEXI 3765@item -enable-kvm 3766@findex -enable-kvm 3767Enable KVM full virtualization support. This option is only available 3768if KVM support is enabled when compiling. 3769ETEXI 3770 3771DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3772 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3773DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3774 "-xen-attach attach to existing xen domain\n" 3775 " libxl will use this when starting QEMU\n", 3776 QEMU_ARCH_ALL) 3777DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3778 "-xen-domid-restrict restrict set of available xen operations\n" 3779 " to specified domain id. (Does not affect\n" 3780 " xenpv machine type).\n", 3781 QEMU_ARCH_ALL) 3782STEXI 3783@item -xen-domid @var{id} 3784@findex -xen-domid 3785Specify xen guest domain @var{id} (XEN only). 3786@item -xen-attach 3787@findex -xen-attach 3788Attach to existing xen domain. 3789libxl will use this when starting QEMU (XEN only). 3790@findex -xen-domid-restrict 3791Restrict set of available xen operations to specified domain id (XEN only). 3792ETEXI 3793 3794DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3795 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3796STEXI 3797@item -no-reboot 3798@findex -no-reboot 3799Exit instead of rebooting. 3800ETEXI 3801 3802DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3803 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3804STEXI 3805@item -no-shutdown 3806@findex -no-shutdown 3807Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3808This allows for instance switching to monitor to commit changes to the 3809disk image. 3810ETEXI 3811 3812DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3813 "-loadvm [tag|id]\n" \ 3814 " start right away with a saved state (loadvm in monitor)\n", 3815 QEMU_ARCH_ALL) 3816STEXI 3817@item -loadvm @var{file} 3818@findex -loadvm 3819Start right away with a saved state (@code{loadvm} in monitor) 3820ETEXI 3821 3822#ifndef _WIN32 3823DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3824 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3825#endif 3826STEXI 3827@item -daemonize 3828@findex -daemonize 3829Daemonize the QEMU process after initialization. QEMU will not detach from 3830standard IO until it is ready to receive connections on any of its devices. 3831This option is a useful way for external programs to launch QEMU without having 3832to cope with initialization race conditions. 3833ETEXI 3834 3835DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3836 "-option-rom rom load a file, rom, into the option ROM space\n", 3837 QEMU_ARCH_ALL) 3838STEXI 3839@item -option-rom @var{file} 3840@findex -option-rom 3841Load the contents of @var{file} as an option ROM. 3842This option is useful to load things like EtherBoot. 3843ETEXI 3844 3845DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3846 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3847 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3848 QEMU_ARCH_ALL) 3849 3850STEXI 3851 3852@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3853@findex -rtc 3854Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3855UTC or local time, respectively. @code{localtime} is required for correct date in 3856MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3857format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3858 3859By default the RTC is driven by the host system time. This allows using of the 3860RTC as accurate reference clock inside the guest, specifically if the host 3861time is smoothly following an accurate external reference clock, e.g. via NTP. 3862If you want to isolate the guest time from the host, you can set @option{clock} 3863to @code{rt} instead, which provides a host monotonic clock if host support it. 3864To even prevent the RTC from progressing during suspension, you can set @option{clock} 3865to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3866icount mode in order to preserve determinism; however, note that in icount mode 3867the speed of the virtual clock is variable and can in general differ from the 3868host clock. 3869 3870Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3871specifically with Windows' ACPI HAL. This option will try to figure out how 3872many timer interrupts were not processed by the Windows guest and will 3873re-inject them. 3874ETEXI 3875 3876DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3877 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3878 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3879 " instruction, enable aligning the host and virtual clocks\n" \ 3880 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3881STEXI 3882@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3883@findex -icount 3884Enable virtual instruction counter. The virtual cpu will execute one 3885instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3886then the virtual cpu speed will be automatically adjusted to keep virtual 3887time within a few seconds of real time. 3888 3889When the virtual cpu is sleeping, the virtual time will advance at default 3890speed unless @option{sleep=on|off} is specified. 3891With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3892instantly whenever the virtual cpu goes to sleep mode and will not advance 3893if no timer is enabled. This behavior give deterministic execution times from 3894the guest point of view. 3895 3896Note that while this option can give deterministic behavior, it does not 3897provide cycle accurate emulation. Modern CPUs contain superscalar out of 3898order cores with complex cache hierarchies. The number of instructions 3899executed often has little or no correlation with actual performance. 3900 3901@option{align=on} will activate the delay algorithm which will try 3902to synchronise the host clock and the virtual clock. The goal is to 3903have a guest running at the real frequency imposed by the shift option. 3904Whenever the guest clock is behind the host clock and if 3905@option{align=on} is specified then we print a message to the user 3906to inform about the delay. 3907Currently this option does not work when @option{shift} is @code{auto}. 3908Note: The sync algorithm will work for those shift values for which 3909the guest clock runs ahead of the host clock. Typically this happens 3910when the shift value is high (how high depends on the host machine). 3911 3912When @option{rr} option is specified deterministic record/replay is enabled. 3913Replay log is written into @var{filename} file in record mode and 3914read from this file in replay mode. 3915 3916Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3917at the start of execution recording. In replay mode this option is used 3918to load the initial VM state. 3919ETEXI 3920 3921DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3922 "-watchdog model\n" \ 3923 " enable virtual hardware watchdog [default=none]\n", 3924 QEMU_ARCH_ALL) 3925STEXI 3926@item -watchdog @var{model} 3927@findex -watchdog 3928Create a virtual hardware watchdog device. Once enabled (by a guest 3929action), the watchdog must be periodically polled by an agent inside 3930the guest or else the guest will be restarted. Choose a model for 3931which your guest has drivers. 3932 3933The @var{model} is the model of hardware watchdog to emulate. Use 3934@code{-watchdog help} to list available hardware models. Only one 3935watchdog can be enabled for a guest. 3936 3937The following models may be available: 3938@table @option 3939@item ib700 3940iBASE 700 is a very simple ISA watchdog with a single timer. 3941@item i6300esb 3942Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3943dual-timer watchdog. 3944@item diag288 3945A virtual watchdog for s390x backed by the diagnose 288 hypercall 3946(currently KVM only). 3947@end table 3948ETEXI 3949 3950DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3951 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3952 " action when watchdog fires [default=reset]\n", 3953 QEMU_ARCH_ALL) 3954STEXI 3955@item -watchdog-action @var{action} 3956@findex -watchdog-action 3957 3958The @var{action} controls what QEMU will do when the watchdog timer 3959expires. 3960The default is 3961@code{reset} (forcefully reset the guest). 3962Other possible actions are: 3963@code{shutdown} (attempt to gracefully shutdown the guest), 3964@code{poweroff} (forcefully poweroff the guest), 3965@code{inject-nmi} (inject a NMI into the guest), 3966@code{pause} (pause the guest), 3967@code{debug} (print a debug message and continue), or 3968@code{none} (do nothing). 3969 3970Note that the @code{shutdown} action requires that the guest responds 3971to ACPI signals, which it may not be able to do in the sort of 3972situations where the watchdog would have expired, and thus 3973@code{-watchdog-action shutdown} is not recommended for production use. 3974 3975Examples: 3976 3977@table @code 3978@item -watchdog i6300esb -watchdog-action pause 3979@itemx -watchdog ib700 3980@end table 3981ETEXI 3982 3983DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3984 "-echr chr set terminal escape character instead of ctrl-a\n", 3985 QEMU_ARCH_ALL) 3986STEXI 3987 3988@item -echr @var{numeric_ascii_value} 3989@findex -echr 3990Change the escape character used for switching to the monitor when using 3991monitor and serial sharing. The default is @code{0x01} when using the 3992@code{-nographic} option. @code{0x01} is equal to pressing 3993@code{Control-a}. You can select a different character from the ascii 3994control keys where 1 through 26 map to Control-a through Control-z. For 3995instance you could use the either of the following to change the escape 3996character to Control-t. 3997@table @code 3998@item -echr 0x14 3999@itemx -echr 20 4000@end table 4001ETEXI 4002 4003DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 4004 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 4005STEXI 4006@item -show-cursor 4007@findex -show-cursor 4008Show cursor. 4009ETEXI 4010 4011DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 4012 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 4013STEXI 4014@item -tb-size @var{n} 4015@findex -tb-size 4016Set TCG translation block cache size. Deprecated, use @samp{-accel tcg,tb-size=@var{n}} 4017instead. 4018ETEXI 4019 4020DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4021 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 4022 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 4023 "-incoming unix:socketpath\n" \ 4024 " prepare for incoming migration, listen on\n" \ 4025 " specified protocol and socket address\n" \ 4026 "-incoming fd:fd\n" \ 4027 "-incoming exec:cmdline\n" \ 4028 " accept incoming migration on given file descriptor\n" \ 4029 " or from given external command\n" \ 4030 "-incoming defer\n" \ 4031 " wait for the URI to be specified via migrate_incoming\n", 4032 QEMU_ARCH_ALL) 4033STEXI 4034@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 4035@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 4036@findex -incoming 4037Prepare for incoming migration, listen on a given tcp port. 4038 4039@item -incoming unix:@var{socketpath} 4040Prepare for incoming migration, listen on a given unix socket. 4041 4042@item -incoming fd:@var{fd} 4043Accept incoming migration from a given filedescriptor. 4044 4045@item -incoming exec:@var{cmdline} 4046Accept incoming migration as an output from specified external command. 4047 4048@item -incoming defer 4049Wait for the URI to be specified via migrate_incoming. The monitor can 4050be used to change settings (such as migration parameters) prior to issuing 4051the migrate_incoming to allow the migration to begin. 4052ETEXI 4053 4054DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4055 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4056STEXI 4057@item -only-migratable 4058@findex -only-migratable 4059Only allow migratable devices. Devices will not be allowed to enter an 4060unmigratable state. 4061ETEXI 4062 4063DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4064 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4065STEXI 4066@item -nodefaults 4067@findex -nodefaults 4068Don't create default devices. Normally, QEMU sets the default devices like serial 4069port, parallel port, virtual console, monitor device, VGA adapter, floppy and 4070CD-ROM drive and others. The @code{-nodefaults} option will disable all those 4071default devices. 4072ETEXI 4073 4074#ifndef _WIN32 4075DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4076 "-chroot dir chroot to dir just before starting the VM\n", 4077 QEMU_ARCH_ALL) 4078#endif 4079STEXI 4080@item -chroot @var{dir} 4081@findex -chroot 4082Immediately before starting guest execution, chroot to the specified 4083directory. Especially useful in combination with -runas. 4084ETEXI 4085 4086#ifndef _WIN32 4087DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4088 "-runas user change to user id user just before starting the VM\n" \ 4089 " user can be numeric uid:gid instead\n", 4090 QEMU_ARCH_ALL) 4091#endif 4092STEXI 4093@item -runas @var{user} 4094@findex -runas 4095Immediately before starting guest execution, drop root privileges, switching 4096to the specified user. 4097ETEXI 4098 4099DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4100 "-prom-env variable=value\n" 4101 " set OpenBIOS nvram variables\n", 4102 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4103STEXI 4104@item -prom-env @var{variable}=@var{value} 4105@findex -prom-env 4106Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4107ETEXI 4108DEF("semihosting", 0, QEMU_OPTION_semihosting, 4109 "-semihosting semihosting mode\n", 4110 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4111 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4112STEXI 4113@item -semihosting 4114@findex -semihosting 4115Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4116ETEXI 4117DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4118 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4119 " semihosting configuration\n", 4120QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4121QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4122STEXI 4123@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]] 4124@findex -semihosting-config 4125Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4126@table @option 4127@item target=@code{native|gdb|auto} 4128Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4129or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4130during debug sessions and @code{native} otherwise. 4131@item chardev=@var{str1} 4132Send the output to a chardev backend output for native or auto output when not in gdb 4133@item arg=@var{str1},arg=@var{str2},... 4134Allows the user to pass input arguments, and can be used multiple times to build 4135up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4136command line is still supported for backward compatibility. If both the 4137@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4138specified, the former is passed to semihosting as it always takes precedence. 4139@end table 4140ETEXI 4141DEF("old-param", 0, QEMU_OPTION_old_param, 4142 "-old-param old param mode\n", QEMU_ARCH_ARM) 4143STEXI 4144@item -old-param 4145@findex -old-param (ARM) 4146Old param mode (ARM only). 4147ETEXI 4148 4149DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4150 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4151 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4152 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4153 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4154 " by the kernel, but typically no longer used by modern\n" \ 4155 " C library implementations.\n" \ 4156 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4157 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4158 " The value 'children' will deny set*uid|gid system calls for\n" \ 4159 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4160 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4161 " blacklisting *fork and execve\n" \ 4162 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4163 QEMU_ARCH_ALL) 4164STEXI 4165@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4166@findex -sandbox 4167Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4168disable it. The default is 'off'. 4169@table @option 4170@item obsolete=@var{string} 4171Enable Obsolete system calls 4172@item elevateprivileges=@var{string} 4173Disable set*uid|gid system calls 4174@item spawn=@var{string} 4175Disable *fork and execve 4176@item resourcecontrol=@var{string} 4177Disable process affinity and schedular priority 4178@end table 4179ETEXI 4180 4181DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4182 "-readconfig <file>\n", QEMU_ARCH_ALL) 4183STEXI 4184@item -readconfig @var{file} 4185@findex -readconfig 4186Read device configuration from @var{file}. This approach is useful when you want to spawn 4187QEMU process with many command line options but you don't want to exceed the command line 4188character limit. 4189ETEXI 4190DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4191 "-writeconfig <file>\n" 4192 " read/write config file\n", QEMU_ARCH_ALL) 4193STEXI 4194@item -writeconfig @var{file} 4195@findex -writeconfig 4196Write device configuration to @var{file}. The @var{file} can be either filename to save 4197command line and device configuration into file or dash @code{-}) character to print the 4198output to stdout. This can be later used as input file for @code{-readconfig} option. 4199ETEXI 4200 4201DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4202 "-no-user-config\n" 4203 " do not load default user-provided config files at startup\n", 4204 QEMU_ARCH_ALL) 4205STEXI 4206@item -no-user-config 4207@findex -no-user-config 4208The @code{-no-user-config} option makes QEMU not load any of the user-provided 4209config files on @var{sysconfdir}. 4210ETEXI 4211 4212DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4213 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4214 " specify tracing options\n", 4215 QEMU_ARCH_ALL) 4216STEXI 4217HXCOMM This line is not accurate, as some sub-options are backend-specific but 4218HXCOMM HX does not support conditional compilation of text. 4219@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4220@findex -trace 4221@include qemu-option-trace.texi 4222ETEXI 4223DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4224 "-plugin [file=]<file>[,arg=<string>]\n" 4225 " load a plugin\n", 4226 QEMU_ARCH_ALL) 4227STEXI 4228@item -plugin file=@var{file}[,arg=@var{string}] 4229@findex -plugin 4230 4231Load a plugin. 4232 4233@table @option 4234@item file=@var{file} 4235Load the given plugin from a shared library file. 4236@item arg=@var{string} 4237Argument string passed to the plugin. (Can be given multiple times.) 4238@end table 4239ETEXI 4240 4241HXCOMM Internal use 4242DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4243DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4244 4245#ifdef __linux__ 4246DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4247 "-enable-fips enable FIPS 140-2 compliance\n", 4248 QEMU_ARCH_ALL) 4249#endif 4250STEXI 4251@item -enable-fips 4252@findex -enable-fips 4253Enable FIPS 140-2 compliance mode. 4254ETEXI 4255 4256HXCOMM Deprecated by -accel tcg 4257DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4258 4259DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4260 "-msg timestamp[=on|off]\n" 4261 " control error message format\n" 4262 " timestamp=on enables timestamps (default: off)\n", 4263 QEMU_ARCH_ALL) 4264STEXI 4265@item -msg timestamp[=on|off] 4266@findex -msg 4267Control error message format. 4268@table @option 4269@item timestamp=on|off 4270Prefix messages with a timestamp. Default is off. 4271@end table 4272ETEXI 4273 4274DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4275 "-dump-vmstate <file>\n" 4276 " Output vmstate information in JSON format to file.\n" 4277 " Use the scripts/vmstate-static-checker.py file to\n" 4278 " check for possible regressions in migration code\n" 4279 " by comparing two such vmstate dumps.\n", 4280 QEMU_ARCH_ALL) 4281STEXI 4282@item -dump-vmstate @var{file} 4283@findex -dump-vmstate 4284Dump json-encoded vmstate information for current machine type to file 4285in @var{file} 4286ETEXI 4287 4288DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4289 "-enable-sync-profile\n" 4290 " enable synchronization profiling\n", 4291 QEMU_ARCH_ALL) 4292STEXI 4293@item -enable-sync-profile 4294@findex -enable-sync-profile 4295Enable synchronization profiling. 4296ETEXI 4297 4298STEXI 4299@end table 4300ETEXI 4301DEFHEADING() 4302 4303DEFHEADING(Generic object creation:) 4304STEXI 4305@table @option 4306ETEXI 4307 4308DEF("object", HAS_ARG, QEMU_OPTION_object, 4309 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4310 " create a new object of type TYPENAME setting properties\n" 4311 " in the order they are specified. Note that the 'id'\n" 4312 " property must be set. These objects are placed in the\n" 4313 " '/objects' path.\n", 4314 QEMU_ARCH_ALL) 4315STEXI 4316@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4317@findex -object 4318Create a new object of type @var{typename} setting properties 4319in the order they are specified. Note that the 'id' 4320property must be set. These objects are placed in the 4321'/objects' path. 4322 4323@table @option 4324 4325@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},align=@var{align} 4326 4327Creates a memory file backend object, which can be used to back 4328the guest RAM with huge pages. 4329 4330The @option{id} parameter is a unique ID that will be used to reference this 4331memory region when configuring the @option{-numa} argument. 4332 4333The @option{size} option provides the size of the memory region, and accepts 4334common suffixes, eg @option{500M}. 4335 4336The @option{mem-path} provides the path to either a shared memory or huge page 4337filesystem mount. 4338 4339The @option{share} boolean option determines whether the memory 4340region is marked as private to QEMU, or shared. The latter allows 4341a co-operating external process to access the QEMU memory region. 4342 4343The @option{share} is also required for pvrdma devices due to 4344limitations in the RDMA API provided by Linux. 4345 4346Setting share=on might affect the ability to configure NUMA 4347bindings for the memory backend under some circumstances, see 4348Documentation/vm/numa_memory_policy.txt on the Linux kernel 4349source tree for additional details. 4350 4351Setting the @option{discard-data} boolean option to @var{on} 4352indicates that file contents can be destroyed when QEMU exits, 4353to avoid unnecessarily flushing data to the backing file. Note 4354that @option{discard-data} is only an optimization, and QEMU 4355might not discard file contents if it aborts unexpectedly or is 4356terminated using SIGKILL. 4357 4358The @option{merge} boolean option enables memory merge, also known as 4359MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4360memory deduplication. 4361 4362Setting the @option{dump} boolean option to @var{off} excludes the memory from 4363core dumps. This feature is also known as MADV_DONTDUMP. 4364 4365The @option{prealloc} boolean option enables memory preallocation. 4366 4367The @option{host-nodes} option binds the memory range to a list of NUMA host 4368nodes. 4369 4370The @option{policy} option sets the NUMA policy to one of the following values: 4371 4372@table @option 4373@item @var{default} 4374default host policy 4375 4376@item @var{preferred} 4377prefer the given host node list for allocation 4378 4379@item @var{bind} 4380restrict memory allocation to the given host node list 4381 4382@item @var{interleave} 4383interleave memory allocations across the given host node list 4384@end table 4385 4386The @option{align} option specifies the base address alignment when 4387QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4388@option{2M}. Some backend store specified by @option{mem-path} 4389requires an alignment different than the default one used by QEMU, eg 4390the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4391such cases, users can specify the required alignment via this option. 4392 4393The @option{pmem} option specifies whether the backing file specified 4394by @option{mem-path} is in host persistent memory that can be accessed 4395using the SNIA NVM programming model (e.g. Intel NVDIMM). 4396If @option{pmem} is set to 'on', QEMU will take necessary operations to 4397guarantee the persistence of its own writes to @option{mem-path} 4398(e.g. in vNVDIMM label emulation and live migration). 4399Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4400file metadata is in sync for @option{mem-path} in case of host crash 4401or a power failure. MAP_SYNC requires support from both the host kernel 4402(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4403with DAX option. 4404 4405@item -object memory-backend-ram,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave} 4406 4407Creates a memory backend object, which can be used to back the guest RAM. 4408Memory backend objects offer more control than the @option{-m} option that is 4409traditionally used to define guest RAM. Please refer to 4410@option{memory-backend-file} for a description of the options. 4411 4412@item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},seal=@var{on|off},hugetlb=@var{on|off},hugetlbsize=@var{size} 4413 4414Creates an anonymous memory file backend object, which allows QEMU to 4415share the memory with an external process (e.g. when using 4416vhost-user). The memory is allocated with memfd and optional 4417sealing. (Linux only) 4418 4419The @option{seal} option creates a sealed-file, that will block 4420further resizing the memory ('on' by default). 4421 4422The @option{hugetlb} option specify the file to be created resides in 4423the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4424the @option{hugetlb} option, the @option{hugetlbsize} option specify 4425the hugetlb page size on systems that support multiple hugetlb page 4426sizes (it must be a power of 2 value supported by the system). 4427 4428In some versions of Linux, the @option{hugetlb} option is incompatible 4429with the @option{seal} option (requires at least Linux 4.16). 4430 4431Please refer to @option{memory-backend-file} for a description of the 4432other options. 4433 4434The @option{share} boolean option is @var{on} by default with memfd. 4435 4436@item -object rng-builtin,id=@var{id} 4437 4438Creates a random number generator backend which obtains entropy from 4439QEMU builtin functions. The @option{id} parameter is a unique ID that 4440will be used to reference this entropy backend from the @option{virtio-rng} 4441device. By default, the @option{virtio-rng} device uses this RNG backend. 4442 4443@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4444 4445Creates a random number generator backend which obtains entropy from 4446a device on the host. The @option{id} parameter is a unique ID that 4447will be used to reference this entropy backend from the @option{virtio-rng} 4448device. The @option{filename} parameter specifies which file to obtain 4449entropy from and if omitted defaults to @option{/dev/urandom}. 4450 4451@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4452 4453Creates a random number generator backend which obtains entropy from 4454an external daemon running on the host. The @option{id} parameter is 4455a unique ID that will be used to reference this entropy backend from 4456the @option{virtio-rng} device. The @option{chardev} parameter is 4457the unique ID of a character device backend that provides the connection 4458to the RNG daemon. 4459 4460@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4461 4462Creates a TLS anonymous credentials object, which can be used to provide 4463TLS support on network backends. The @option{id} parameter is a unique 4464ID which network backends will use to access the credentials. The 4465@option{endpoint} is either @option{server} or @option{client} depending 4466on whether the QEMU network backend that uses the credentials will be 4467acting as a client or as a server. If @option{verify-peer} is enabled 4468(the default) then once the handshake is completed, the peer credentials 4469will be verified, though this is a no-op for anonymous credentials. 4470 4471The @var{dir} parameter tells QEMU where to find the credential 4472files. For server endpoints, this directory may contain a file 4473@var{dh-params.pem} providing diffie-hellman parameters to use 4474for the TLS server. If the file is missing, QEMU will generate 4475a set of DH parameters at startup. This is a computationally 4476expensive operation that consumes random pool entropy, so it is 4477recommended that a persistent set of parameters be generated 4478upfront and saved. 4479 4480@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4481 4482Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4483TLS support on network backends. The @option{id} parameter is a unique 4484ID which network backends will use to access the credentials. The 4485@option{endpoint} is either @option{server} or @option{client} depending 4486on whether the QEMU network backend that uses the credentials will be 4487acting as a client or as a server. For clients only, @option{username} 4488is the username which will be sent to the server. If omitted 4489it defaults to ``qemu''. 4490 4491The @var{dir} parameter tells QEMU where to find the keys file. 4492It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4493pairs. This file can most easily be created using the GnuTLS 4494@code{psktool} program. 4495 4496For server endpoints, @var{dir} may also contain a file 4497@var{dh-params.pem} providing diffie-hellman parameters to use 4498for the TLS server. If the file is missing, QEMU will generate 4499a set of DH parameters at startup. This is a computationally 4500expensive operation that consumes random pool entropy, so it is 4501recommended that a persistent set of parameters be generated 4502up front and saved. 4503 4504@item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},priority=@var{priority},verify-peer=@var{on|off},passwordid=@var{id} 4505 4506Creates a TLS anonymous credentials object, which can be used to provide 4507TLS support on network backends. The @option{id} parameter is a unique 4508ID which network backends will use to access the credentials. The 4509@option{endpoint} is either @option{server} or @option{client} depending 4510on whether the QEMU network backend that uses the credentials will be 4511acting as a client or as a server. If @option{verify-peer} is enabled 4512(the default) then once the handshake is completed, the peer credentials 4513will be verified. With x509 certificates, this implies that the clients 4514must be provided with valid client certificates too. 4515 4516The @var{dir} parameter tells QEMU where to find the credential 4517files. For server endpoints, this directory may contain a file 4518@var{dh-params.pem} providing diffie-hellman parameters to use 4519for the TLS server. If the file is missing, QEMU will generate 4520a set of DH parameters at startup. This is a computationally 4521expensive operation that consumes random pool entropy, so it is 4522recommended that a persistent set of parameters be generated 4523upfront and saved. 4524 4525For x509 certificate credentials the directory will contain further files 4526providing the x509 certificates. The certificates must be stored 4527in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4528@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4529@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4530 4531For the @var{server-key.pem} and @var{client-key.pem} files which 4532contain sensitive private keys, it is possible to use an encrypted 4533version by providing the @var{passwordid} parameter. This provides 4534the ID of a previously created @code{secret} object containing the 4535password for decryption. 4536 4537The @var{priority} parameter allows to override the global default 4538priority used by gnutls. This can be useful if the system administrator 4539needs to use a weaker set of crypto priorities for QEMU without 4540potentially forcing the weakness onto all applications. Or conversely 4541if one wants wants a stronger default for QEMU than for all other 4542applications, they can do this through this parameter. Its format is 4543a gnutls priority string as described at 4544@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4545 4546@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4547 4548Interval @var{t} can't be 0, this filter batches the packet delivery: all 4549packets arriving in a given interval on netdev @var{netdevid} are delayed 4550until the end of the interval. Interval is in microseconds. 4551@option{status} is optional that indicate whether the netfilter is 4552on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4553 4554queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4555 4556@option{all}: the filter is attached both to the receive and the transmit 4557 queue of the netdev (default). 4558 4559@option{rx}: the filter is attached to the receive queue of the netdev, 4560 where it will receive packets sent to the netdev. 4561 4562@option{tx}: the filter is attached to the transmit queue of the netdev, 4563 where it will receive packets sent by the netdev. 4564 4565@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4566 4567filter-mirror on netdev @var{netdevid},mirror net packet to chardev@var{chardevid}, if it has the vnet_hdr_support flag, filter-mirror will mirror packet with vnet_hdr_len. 4568 4569@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4570 4571filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4572@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4573filter-redirector will redirect packet with vnet_hdr_len. 4574Create a filter-redirector we need to differ outdev id from indev id, id can not 4575be the same. we can just use indev or outdev, but at least one of indev or outdev 4576need to be specified. 4577 4578@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4579 4580Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4581secondary from primary to keep secondary tcp connection,and rewrite 4582tcp packet to primary from secondary make tcp packet can be handled by 4583client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4584 4585usage: 4586colo secondary: 4587-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4588-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4589-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4590 4591@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4592 4593Dump the network traffic on netdev @var{dev} to the file specified by 4594@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4595The file format is libpcap, so it can be analyzed with tools such as tcpdump 4596or Wireshark. 4597 4598@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid},iothread=@var{id}[,vnet_hdr_support][,notify_dev=@var{id}] 4599 4600Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4601secondary packet. If the packets are same, we will output primary 4602packet to outdev@var{chardevid}, else we will notify colo-frame 4603do checkpoint and send primary packet to outdev@var{chardevid}. 4604In order to improve efficiency, we need to put the task of comparison 4605in another thread. If it has the vnet_hdr_support flag, colo compare 4606will send/recv packet with vnet_hdr_len. 4607If you want to use Xen COLO, will need the notify_dev to notify Xen 4608colo-frame to do checkpoint. 4609 4610we must use it with the help of filter-mirror and filter-redirector. 4611 4612@example 4613 4614KVM COLO 4615 4616primary: 4617-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4618-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4619-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4620-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4621-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4622-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4623-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4624-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4625-object iothread,id=iothread1 4626-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4627-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4628-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4629-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4630 4631secondary: 4632-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4633-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4634-chardev socket,id=red0,host=3.3.3.3,port=9003 4635-chardev socket,id=red1,host=3.3.3.3,port=9004 4636-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4637-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4638 4639 4640Xen COLO 4641 4642primary: 4643-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4644-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4645-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4646-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4647-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4648-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4649-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4650-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4651-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4652-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4653-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4654-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4655-object iothread,id=iothread1 4656-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4657 4658secondary: 4659-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4660-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4661-chardev socket,id=red0,host=3.3.3.3,port=9003 4662-chardev socket,id=red1,host=3.3.3.3,port=9004 4663-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4664-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4665 4666@end example 4667 4668If you want to know the detail of above command line, you can read 4669the colo-compare git log. 4670 4671@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4672 4673Creates a cryptodev backend which executes crypto opreation from 4674the QEMU cipher APIS. The @var{id} parameter is 4675a unique ID that will be used to reference this cryptodev backend from 4676the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4677which specify the queue number of cryptodev backend, the default of 4678@var{queues} is 1. 4679 4680@example 4681 4682 # @value{qemu_system} \ 4683 [...] \ 4684 -object cryptodev-backend-builtin,id=cryptodev0 \ 4685 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4686 [...] 4687@end example 4688 4689@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4690 4691Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4692The @var{id} parameter is a unique ID that will be used to reference this 4693cryptodev backend from the @option{virtio-crypto} device. 4694The chardev should be a unix domain socket backed one. The vhost-user uses 4695a specifically defined protocol to pass vhost ioctl replacement messages 4696to an application on the other end of the socket. 4697The @var{queues} parameter is optional, which specify the queue number 4698of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4699 4700@example 4701 4702 # @value{qemu_system} \ 4703 [...] \ 4704 -chardev socket,id=chardev0,path=/path/to/socket \ 4705 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4706 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4707 [...] 4708@end example 4709 4710@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4711@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4712 4713Defines a secret to store a password, encryption key, or some other sensitive 4714data. The sensitive data can either be passed directly via the @var{data} 4715parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4716parameter is insecure unless the sensitive data is encrypted. 4717 4718The sensitive data can be provided in raw format (the default), or base64. 4719When encoded as JSON, the raw format only supports valid UTF-8 characters, 4720so base64 is recommended for sending binary data. QEMU will convert from 4721which ever format is provided to the format it needs internally. eg, an 4722RBD password can be provided in raw format, even though it will be base64 4723encoded when passed onto the RBD sever. 4724 4725For added protection, it is possible to encrypt the data associated with 4726a secret using the AES-256-CBC cipher. Use of encryption is indicated 4727by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4728parameter provides the ID of a previously defined secret that contains 4729the AES-256 decryption key. This key should be 32-bytes long and be 4730base64 encoded. The @var{iv} parameter provides the random initialization 4731vector used for encryption of this particular secret and should be a 4732base64 encrypted string of the 16-byte IV. 4733 4734The simplest (insecure) usage is to provide the secret inline 4735 4736@example 4737 4738 # @value{qemu_system} -object secret,id=sec0,data=letmein,format=raw 4739 4740@end example 4741 4742The simplest secure usage is to provide the secret via a file 4743 4744 # printf "letmein" > mypasswd.txt 4745 # @value{qemu_system} -object secret,id=sec0,file=mypasswd.txt,format=raw 4746 4747For greater security, AES-256-CBC should be used. To illustrate usage, 4748consider the openssl command line tool which can encrypt the data. Note 4749that when encrypting, the plaintext must be padded to the cipher block 4750size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4751 4752First a master key needs to be created in base64 encoding: 4753 4754@example 4755 # openssl rand -base64 32 > key.b64 4756 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4757@end example 4758 4759Each secret to be encrypted needs to have a random initialization vector 4760generated. These do not need to be kept secret 4761 4762@example 4763 # openssl rand -base64 16 > iv.b64 4764 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4765@end example 4766 4767The secret to be defined can now be encrypted, in this case we're 4768telling openssl to base64 encode the result, but it could be left 4769as raw bytes if desired. 4770 4771@example 4772 # SECRET=$(printf "letmein" | 4773 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4774@end example 4775 4776When launching QEMU, create a master secret pointing to @code{key.b64} 4777and specify that to be used to decrypt the user password. Pass the 4778contents of @code{iv.b64} to the second secret 4779 4780@example 4781 # @value{qemu_system} \ 4782 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4783 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4784 data=$SECRET,iv=$(<iv.b64) 4785@end example 4786 4787@item -object sev-guest,id=@var{id},cbitpos=@var{cbitpos},reduced-phys-bits=@var{val},[sev-device=@var{string},policy=@var{policy},handle=@var{handle},dh-cert-file=@var{file},session-file=@var{file}] 4788 4789Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4790to provide the guest memory encryption support on AMD processors. 4791 4792When memory encryption is enabled, one of the physical address bit (aka the 4793C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4794is used to provide the C-bit position. The C-bit position is Host family dependent 4795hence user must provide this value. On EPYC, the value should be 47. 4796 4797When memory encryption is enabled, we loose certain bits in physical address space. 4798The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4799physical address space. Similar to C-bit, the value is Host family dependent. 4800On EPYC, the value should be 5. 4801 4802The @option{sev-device} provides the device file to use for communicating with 4803the SEV firmware running inside AMD Secure Processor. The default device is 4804'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4805created by CCP driver. 4806 4807The @option{policy} provides the guest policy to be enforced by the SEV firmware 4808and restrict what configuration and operational commands can be performed on this 4809guest by the hypervisor. The policy should be provided by the guest owner and is 4810bound to the guest and cannot be changed throughout the lifetime of the guest. 4811The default is 0. 4812 4813If guest @option{policy} allows sharing the key with another SEV guest then 4814@option{handle} can be use to provide handle of the guest from which to share 4815the key. 4816 4817The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4818Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4819are used for establishing a cryptographic session with the guest owner to 4820negotiate keys used for attestation. The file must be encoded in base64. 4821 4822e.g to launch a SEV guest 4823@example 4824 # @value{qemu_system_x86} \ 4825 ...... 4826 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4827 -machine ...,memory-encryption=sev0 4828 ..... 4829 4830@end example 4831 4832 4833@item -object authz-simple,id=@var{id},identity=@var{string} 4834 4835Create an authorization object that will control access to network services. 4836 4837The @option{identity} parameter is identifies the user and its format 4838depends on the network service that authorization object is associated 4839with. For authorizing based on TLS x509 certificates, the identity must 4840be the x509 distinguished name. Note that care must be taken to escape 4841any commas in the distinguished name. 4842 4843An example authorization object to validate a x509 distinguished name 4844would look like: 4845@example 4846 # @value{qemu_system} \ 4847 ... 4848 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4849 ... 4850@end example 4851 4852Note the use of quotes due to the x509 distinguished name containing 4853whitespace, and escaping of ','. 4854 4855@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4856 4857Create an authorization object that will control access to network services. 4858 4859The @option{filename} parameter is the fully qualified path to a file 4860containing the access control list rules in JSON format. 4861 4862An example set of rules that match against SASL usernames might look 4863like: 4864 4865@example 4866 @{ 4867 "rules": [ 4868 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4869 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4870 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4871 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4872 ], 4873 "policy": "deny" 4874 @} 4875@end example 4876 4877When checking access the object will iterate over all the rules and 4878the first rule to match will have its @option{policy} value returned 4879as the result. If no rules match, then the default @option{policy} 4880value is returned. 4881 4882The rules can either be an exact string match, or they can use the 4883simple UNIX glob pattern matching to allow wildcards to be used. 4884 4885If @option{refresh} is set to true the file will be monitored 4886and automatically reloaded whenever its content changes. 4887 4888As with the @code{authz-simple} object, the format of the identity 4889strings being matched depends on the network service, but is usually 4890a TLS x509 distinguished name, or a SASL username. 4891 4892An example authorization object to validate a SASL username 4893would look like: 4894@example 4895 # @value{qemu_system} \ 4896 ... 4897 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4898 ... 4899@end example 4900 4901@item -object authz-pam,id=@var{id},service=@var{string} 4902 4903Create an authorization object that will control access to network services. 4904 4905The @option{service} parameter provides the name of a PAM service to use 4906for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4907exist to provide the configuration for the @code{account} subsystem. 4908 4909An example authorization object to validate a TLS x509 distinguished 4910name would look like: 4911 4912@example 4913 # @value{qemu_system} \ 4914 ... 4915 -object authz-pam,id=auth0,service=qemu-vnc 4916 ... 4917@end example 4918 4919There would then be a corresponding config file for PAM at 4920@code{/etc/pam.d/qemu-vnc} that contains: 4921 4922@example 4923account requisite pam_listfile.so item=user sense=allow \ 4924 file=/etc/qemu/vnc.allow 4925@end example 4926 4927Finally the @code{/etc/qemu/vnc.allow} file would contain 4928the list of x509 distingished names that are permitted 4929access 4930 4931@example 4932CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4933@end example 4934 4935@item -object iothread,id=@var{id},poll-max-ns=@var{poll-max-ns},poll-grow=@var{poll-grow},poll-shrink=@var{poll-shrink} 4936 4937Creates a dedicated event loop thread that devices can be assigned to. This is 4938known as an IOThread. By default device emulation happens in vCPU threads or 4939the main event loop thread. This can become a scalability bottleneck. 4940IOThreads allow device emulation and I/O to run on other host CPUs. 4941 4942The @option{id} parameter is a unique ID that will be used to reference this 4943IOThread from @option{-device ...,iothread=@var{id}}. Multiple devices can be 4944assigned to an IOThread. Note that not all devices support an 4945@option{iothread} parameter. 4946 4947The @code{query-iothreads} QMP command lists IOThreads and reports their thread 4948IDs so that the user can configure host CPU pinning/affinity. 4949 4950IOThreads use an adaptive polling algorithm to reduce event loop latency. 4951Instead of entering a blocking system call to monitor file descriptors and then 4952pay the cost of being woken up when an event occurs, the polling algorithm 4953spins waiting for events for a short time. The algorithm's default parameters 4954are suitable for many cases but can be adjusted based on knowledge of the 4955workload and/or host device latency. 4956 4957The @option{poll-max-ns} parameter is the maximum number of nanoseconds to busy 4958wait for events. Polling can be disabled by setting this value to 0. 4959 4960The @option{poll-grow} parameter is the multiplier used to increase the polling 4961time when the algorithm detects it is missing events due to not polling long 4962enough. 4963 4964The @option{poll-shrink} parameter is the divisor used to decrease the polling 4965time when the algorithm detects it is spending too long polling without 4966encountering events. 4967 4968The polling parameters can be modified at run-time using the @code{qom-set} command (where @code{iothread1} is the IOThread's @code{id}): 4969 4970@example 4971(qemu) qom-set /objects/iothread1 poll-max-ns 100000 4972@end example 4973 4974@end table 4975 4976ETEXI 4977 4978 4979HXCOMM This is the last statement. Insert new options before this line! 4980STEXI 4981@end table 4982ETEXI 4983
