qemu/qemu-doc.texi
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   1\input texinfo @c -*- texinfo -*-
   2@c %**start of header
   3@setfilename qemu-doc.info
   4@include version.texi
   5
   6@documentlanguage en
   7@documentencoding UTF-8
   8
   9@settitle QEMU version @value{VERSION} User Documentation
  10@exampleindent 0
  11@paragraphindent 0
  12@c %**end of header
  13
  14@ifinfo
  15@direntry
  16* QEMU: (qemu-doc).    The QEMU Emulator User Documentation.
  17@end direntry
  18@end ifinfo
  19
  20@iftex
  21@titlepage
  22@sp 7
  23@center @titlefont{QEMU version @value{VERSION}}
  24@sp 1
  25@center @titlefont{User Documentation}
  26@sp 3
  27@end titlepage
  28@end iftex
  29
  30@ifnottex
  31@node Top
  32@top
  33
  34@menu
  35* Introduction::
  36* QEMU PC System emulator::
  37* QEMU System emulator for non PC targets::
  38* QEMU Guest Agent::
  39* QEMU User space emulator::
  40* Implementation notes::
  41* Deprecated features::
  42* Supported build platforms::
  43* License::
  44* Index::
  45@end menu
  46@end ifnottex
  47
  48@contents
  49
  50@node Introduction
  51@chapter Introduction
  52
  53@menu
  54* intro_features:: Features
  55@end menu
  56
  57@node intro_features
  58@section Features
  59
  60QEMU is a FAST! processor emulator using dynamic translation to
  61achieve good emulation speed.
  62
  63@cindex operating modes
  64QEMU has two operating modes:
  65
  66@itemize
  67@cindex system emulation
  68@item Full system emulation. In this mode, QEMU emulates a full system (for
  69example a PC), including one or several processors and various
  70peripherals. It can be used to launch different Operating Systems
  71without rebooting the PC or to debug system code.
  72
  73@cindex user mode emulation
  74@item User mode emulation. In this mode, QEMU can launch
  75processes compiled for one CPU on another CPU. It can be used to
  76launch the Wine Windows API emulator (@url{https://www.winehq.org}) or
  77to ease cross-compilation and cross-debugging.
  78
  79@end itemize
  80
  81QEMU has the following features:
  82
  83@itemize
  84@item QEMU can run without a host kernel driver and yet gives acceptable
  85performance.  It uses dynamic translation to native code for reasonable speed,
  86with support for self-modifying code and precise exceptions.
  87
  88@item It is portable to several operating systems (GNU/Linux, *BSD, Mac OS X,
  89Windows) and architectures.
  90
  91@item It performs accurate software emulation of the FPU.
  92@end itemize
  93
  94QEMU user mode emulation has the following features:
  95@itemize
  96@item Generic Linux system call converter, including most ioctls.
  97
  98@item clone() emulation using native CPU clone() to use Linux scheduler for threads.
  99
 100@item Accurate signal handling by remapping host signals to target signals.
 101@end itemize
 102
 103QEMU full system emulation has the following features:
 104@itemize
 105@item
 106QEMU uses a full software MMU for maximum portability.
 107
 108@item
 109QEMU can optionally use an in-kernel accelerator, like kvm. The accelerators
 110execute most of the guest code natively, while
 111continuing to emulate the rest of the machine.
 112
 113@item
 114Various hardware devices can be emulated and in some cases, host
 115devices (e.g. serial and parallel ports, USB, drives) can be used
 116transparently by the guest Operating System. Host device passthrough
 117can be used for talking to external physical peripherals (e.g. a
 118webcam, modem or tape drive).
 119
 120@item
 121Symmetric multiprocessing (SMP) support.  Currently, an in-kernel
 122accelerator is required to use more than one host CPU for emulation.
 123
 124@end itemize
 125
 126
 127@node QEMU PC System emulator
 128@chapter QEMU PC System emulator
 129@cindex system emulation (PC)
 130
 131@menu
 132* pcsys_introduction:: Introduction
 133* pcsys_quickstart::   Quick Start
 134* sec_invocation::     Invocation
 135* pcsys_keys::         Keys in the graphical frontends
 136* mux_keys::           Keys in the character backend multiplexer
 137* pcsys_monitor::      QEMU Monitor
 138* disk_images::        Disk Images
 139* pcsys_network::      Network emulation
 140* pcsys_other_devs::   Other Devices
 141* direct_linux_boot::  Direct Linux Boot
 142* pcsys_usb::          USB emulation
 143* vnc_security::       VNC security
 144* network_tls::        TLS setup for network services
 145* gdb_usage::          GDB usage
 146* pcsys_os_specific::  Target OS specific information
 147@end menu
 148
 149@node pcsys_introduction
 150@section Introduction
 151
 152@c man begin DESCRIPTION
 153
 154The QEMU PC System emulator simulates the
 155following peripherals:
 156
 157@itemize @minus
 158@item
 159i440FX host PCI bridge and PIIX3 PCI to ISA bridge
 160@item
 161Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
 162extensions (hardware level, including all non standard modes).
 163@item
 164PS/2 mouse and keyboard
 165@item
 1662 PCI IDE interfaces with hard disk and CD-ROM support
 167@item
 168Floppy disk
 169@item
 170PCI and ISA network adapters
 171@item
 172Serial ports
 173@item
 174IPMI BMC, either and internal or external one
 175@item
 176Creative SoundBlaster 16 sound card
 177@item
 178ENSONIQ AudioPCI ES1370 sound card
 179@item
 180Intel 82801AA AC97 Audio compatible sound card
 181@item
 182Intel HD Audio Controller and HDA codec
 183@item
 184Adlib (OPL2) - Yamaha YM3812 compatible chip
 185@item
 186Gravis Ultrasound GF1 sound card
 187@item
 188CS4231A compatible sound card
 189@item
 190PCI UHCI, OHCI, EHCI or XHCI USB controller and a virtual USB-1.1 hub.
 191@end itemize
 192
 193SMP is supported with up to 255 CPUs.
 194
 195QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs LGPL
 196VGA BIOS.
 197
 198QEMU uses YM3812 emulation by Tatsuyuki Satoh.
 199
 200QEMU uses GUS emulation (GUSEMU32 @url{http://www.deinmeister.de/gusemu/})
 201by Tibor "TS" Schütz.
 202
 203Note that, by default, GUS shares IRQ(7) with parallel ports and so
 204QEMU must be told to not have parallel ports to have working GUS.
 205
 206@example
 207qemu-system-i386 dos.img -soundhw gus -parallel none
 208@end example
 209
 210Alternatively:
 211@example
 212qemu-system-i386 dos.img -device gus,irq=5
 213@end example
 214
 215Or some other unclaimed IRQ.
 216
 217CS4231A is the chip used in Windows Sound System and GUSMAX products
 218
 219@c man end
 220
 221@node pcsys_quickstart
 222@section Quick Start
 223@cindex quick start
 224
 225Download and uncompress the linux image (@file{linux.img}) and type:
 226
 227@example
 228qemu-system-i386 linux.img
 229@end example
 230
 231Linux should boot and give you a prompt.
 232
 233@node sec_invocation
 234@section Invocation
 235
 236@example
 237@c man begin SYNOPSIS
 238@command{qemu-system-i386} [@var{options}] [@var{disk_image}]
 239@c man end
 240@end example
 241
 242@c man begin OPTIONS
 243@var{disk_image} is a raw hard disk image for IDE hard disk 0. Some
 244targets do not need a disk image.
 245
 246@include qemu-options.texi
 247
 248@c man end
 249
 250@subsection Device URL Syntax
 251@c TODO merge this with section Disk Images
 252
 253@c man begin NOTES
 254
 255In addition to using normal file images for the emulated storage devices,
 256QEMU can also use networked resources such as iSCSI devices. These are
 257specified using a special URL syntax.
 258
 259@table @option
 260@item iSCSI
 261iSCSI support allows QEMU to access iSCSI resources directly and use as
 262images for the guest storage. Both disk and cdrom images are supported.
 263
 264Syntax for specifying iSCSI LUNs is
 265``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
 266
 267By default qemu will use the iSCSI initiator-name
 268'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
 269line or a configuration file.
 270
 271Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
 272stalled requests and force a reestablishment of the session. The timeout
 273is specified in seconds. The default is 0 which means no timeout. Libiscsi
 2741.15.0 or greater is required for this feature.
 275
 276Example (without authentication):
 277@example
 278qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
 279                 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
 280                 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
 281@end example
 282
 283Example (CHAP username/password via URL):
 284@example
 285qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
 286@end example
 287
 288Example (CHAP username/password via environment variables):
 289@example
 290LIBISCSI_CHAP_USERNAME="user" \
 291LIBISCSI_CHAP_PASSWORD="password" \
 292qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
 293@end example
 294
 295@item NBD
 296QEMU supports NBD (Network Block Devices) both using TCP protocol as well
 297as Unix Domain Sockets.
 298
 299Syntax for specifying a NBD device using TCP
 300``nbd:<server-ip>:<port>[:exportname=<export>]''
 301
 302Syntax for specifying a NBD device using Unix Domain Sockets
 303``nbd:unix:<domain-socket>[:exportname=<export>]''
 304
 305Example for TCP
 306@example
 307qemu-system-i386 --drive file=nbd:192.0.2.1:30000
 308@end example
 309
 310Example for Unix Domain Sockets
 311@example
 312qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
 313@end example
 314
 315@item SSH
 316QEMU supports SSH (Secure Shell) access to remote disks.
 317
 318Examples:
 319@example
 320qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
 321qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
 322@end example
 323
 324Currently authentication must be done using ssh-agent.  Other
 325authentication methods may be supported in future.
 326
 327@item Sheepdog
 328Sheepdog is a distributed storage system for QEMU.
 329QEMU supports using either local sheepdog devices or remote networked
 330devices.
 331
 332Syntax for specifying a sheepdog device
 333@example
 334sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
 335@end example
 336
 337Example
 338@example
 339qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
 340@end example
 341
 342See also @url{https://sheepdog.github.io/sheepdog/}.
 343
 344@item GlusterFS
 345GlusterFS is a user space distributed file system.
 346QEMU supports the use of GlusterFS volumes for hosting VM disk images using
 347TCP, Unix Domain Sockets and RDMA transport protocols.
 348
 349Syntax for specifying a VM disk image on GlusterFS volume is
 350@example
 351
 352URI:
 353gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]
 354
 355JSON:
 356'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
 357@                                 "server":[@{"type":"tcp","host":"...","port":"..."@},
 358@                                           @{"type":"unix","socket":"..."@}]@}@}'
 359@end example
 360
 361
 362Example
 363@example
 364URI:
 365qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img,
 366@                               file.debug=9,file.logfile=/var/log/qemu-gluster.log
 367
 368JSON:
 369qemu-system-x86_64 'json:@{"driver":"qcow2",
 370@                          "file":@{"driver":"gluster",
 371@                                   "volume":"testvol","path":"a.img",
 372@                                   "debug":9,"logfile":"/var/log/qemu-gluster.log",
 373@                                   "server":[@{"type":"tcp","host":"1.2.3.4","port":24007@},
 374@                                             @{"type":"unix","socket":"/var/run/glusterd.socket"@}]@}@}'
 375qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
 376@                                      file.debug=9,file.logfile=/var/log/qemu-gluster.log,
 377@                                      file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
 378@                                      file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket
 379@end example
 380
 381See also @url{http://www.gluster.org}.
 382
 383@item HTTP/HTTPS/FTP/FTPS
 384QEMU supports read-only access to files accessed over http(s) and ftp(s).
 385
 386Syntax using a single filename:
 387@example
 388<protocol>://[<username>[:<password>]@@]<host>/<path>
 389@end example
 390
 391where:
 392@table @option
 393@item protocol
 394'http', 'https', 'ftp', or 'ftps'.
 395
 396@item username
 397Optional username for authentication to the remote server.
 398
 399@item password
 400Optional password for authentication to the remote server.
 401
 402@item host
 403Address of the remote server.
 404
 405@item path
 406Path on the remote server, including any query string.
 407@end table
 408
 409The following options are also supported:
 410@table @option
 411@item url
 412The full URL when passing options to the driver explicitly.
 413
 414@item readahead
 415The amount of data to read ahead with each range request to the remote server.
 416This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
 417does not have a suffix, it will be assumed to be in bytes. The value must be a
 418multiple of 512 bytes. It defaults to 256k.
 419
 420@item sslverify
 421Whether to verify the remote server's certificate when connecting over SSL. It
 422can have the value 'on' or 'off'. It defaults to 'on'.
 423
 424@item cookie
 425Send this cookie (it can also be a list of cookies separated by ';') with
 426each outgoing request.  Only supported when using protocols such as HTTP
 427which support cookies, otherwise ignored.
 428
 429@item timeout
 430Set the timeout in seconds of the CURL connection. This timeout is the time
 431that CURL waits for a response from the remote server to get the size of the
 432image to be downloaded. If not set, the default timeout of 5 seconds is used.
 433@end table
 434
 435Note that when passing options to qemu explicitly, @option{driver} is the value
 436of <protocol>.
 437
 438Example: boot from a remote Fedora 20 live ISO image
 439@example
 440qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
 441
 442qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
 443@end example
 444
 445Example: boot from a remote Fedora 20 cloud image using a local overlay for
 446writes, copy-on-read, and a readahead of 64k
 447@example
 448qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2
 449
 450qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
 451@end example
 452
 453Example: boot from an image stored on a VMware vSphere server with a self-signed
 454certificate using a local overlay for writes, a readahead of 64k and a timeout
 455of 10 seconds.
 456@example
 457qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@}' /tmp/test.qcow2
 458
 459qemu-system-x86_64 -drive file=/tmp/test.qcow2
 460@end example
 461
 462@end table
 463
 464@c man end
 465
 466@node pcsys_keys
 467@section Keys in the graphical frontends
 468
 469@c man begin OPTIONS
 470
 471During the graphical emulation, you can use special key combinations to change
 472modes. The default key mappings are shown below, but if you use @code{-alt-grab}
 473then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use
 474@code{-ctrl-grab} then the modifier is the right Ctrl key (instead of Ctrl-Alt):
 475
 476@table @key
 477@item Ctrl-Alt-f
 478@kindex Ctrl-Alt-f
 479Toggle full screen
 480
 481@item Ctrl-Alt-+
 482@kindex Ctrl-Alt-+
 483Enlarge the screen
 484
 485@item Ctrl-Alt--
 486@kindex Ctrl-Alt--
 487Shrink the screen
 488
 489@item Ctrl-Alt-u
 490@kindex Ctrl-Alt-u
 491Restore the screen's un-scaled dimensions
 492
 493@item Ctrl-Alt-n
 494@kindex Ctrl-Alt-n
 495Switch to virtual console 'n'. Standard console mappings are:
 496@table @emph
 497@item 1
 498Target system display
 499@item 2
 500Monitor
 501@item 3
 502Serial port
 503@end table
 504
 505@item Ctrl-Alt
 506@kindex Ctrl-Alt
 507Toggle mouse and keyboard grab.
 508@end table
 509
 510@kindex Ctrl-Up
 511@kindex Ctrl-Down
 512@kindex Ctrl-PageUp
 513@kindex Ctrl-PageDown
 514In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
 515@key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
 516
 517@c man end
 518
 519@node mux_keys
 520@section Keys in the character backend multiplexer
 521
 522@c man begin OPTIONS
 523
 524During emulation, if you are using a character backend multiplexer
 525(which is the default if you are using @option{-nographic}) then
 526several commands are available via an escape sequence. These
 527key sequences all start with an escape character, which is @key{Ctrl-a}
 528by default, but can be changed with @option{-echr}. The list below assumes
 529you're using the default.
 530
 531@table @key
 532@item Ctrl-a h
 533@kindex Ctrl-a h
 534Print this help
 535@item Ctrl-a x
 536@kindex Ctrl-a x
 537Exit emulator
 538@item Ctrl-a s
 539@kindex Ctrl-a s
 540Save disk data back to file (if -snapshot)
 541@item Ctrl-a t
 542@kindex Ctrl-a t
 543Toggle console timestamps
 544@item Ctrl-a b
 545@kindex Ctrl-a b
 546Send break (magic sysrq in Linux)
 547@item Ctrl-a c
 548@kindex Ctrl-a c
 549Rotate between the frontends connected to the multiplexer (usually
 550this switches between the monitor and the console)
 551@item Ctrl-a Ctrl-a
 552@kindex Ctrl-a Ctrl-a
 553Send the escape character to the frontend
 554@end table
 555@c man end
 556
 557@ignore
 558
 559@c man begin SEEALSO
 560The HTML documentation of QEMU for more precise information and Linux
 561user mode emulator invocation.
 562@c man end
 563
 564@c man begin AUTHOR
 565Fabrice Bellard
 566@c man end
 567
 568@end ignore
 569
 570@node pcsys_monitor
 571@section QEMU Monitor
 572@cindex QEMU monitor
 573
 574The QEMU monitor is used to give complex commands to the QEMU
 575emulator. You can use it to:
 576
 577@itemize @minus
 578
 579@item
 580Remove or insert removable media images
 581(such as CD-ROM or floppies).
 582
 583@item
 584Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
 585from a disk file.
 586
 587@item Inspect the VM state without an external debugger.
 588
 589@end itemize
 590
 591@subsection Commands
 592
 593The following commands are available:
 594
 595@include qemu-monitor.texi
 596
 597@include qemu-monitor-info.texi
 598
 599@subsection Integer expressions
 600
 601The monitor understands integers expressions for every integer
 602argument. You can use register names to get the value of specifics
 603CPU registers by prefixing them with @emph{$}.
 604
 605@node disk_images
 606@section Disk Images
 607
 608QEMU supports many disk image formats, including growable disk images
 609(their size increase as non empty sectors are written), compressed and
 610encrypted disk images.
 611
 612@menu
 613* disk_images_quickstart::    Quick start for disk image creation
 614* disk_images_snapshot_mode:: Snapshot mode
 615* vm_snapshots::              VM snapshots
 616* qemu_img_invocation::       qemu-img Invocation
 617* qemu_nbd_invocation::       qemu-nbd Invocation
 618* disk_images_formats::       Disk image file formats
 619* host_drives::               Using host drives
 620* disk_images_fat_images::    Virtual FAT disk images
 621* disk_images_nbd::           NBD access
 622* disk_images_sheepdog::      Sheepdog disk images
 623* disk_images_iscsi::         iSCSI LUNs
 624* disk_images_gluster::       GlusterFS disk images
 625* disk_images_ssh::           Secure Shell (ssh) disk images
 626* disk_images_nvme::          NVMe userspace driver
 627* disk_image_locking::        Disk image file locking
 628@end menu
 629
 630@node disk_images_quickstart
 631@subsection Quick start for disk image creation
 632
 633You can create a disk image with the command:
 634@example
 635qemu-img create myimage.img mysize
 636@end example
 637where @var{myimage.img} is the disk image filename and @var{mysize} is its
 638size in kilobytes. You can add an @code{M} suffix to give the size in
 639megabytes and a @code{G} suffix for gigabytes.
 640
 641See @ref{qemu_img_invocation} for more information.
 642
 643@node disk_images_snapshot_mode
 644@subsection Snapshot mode
 645
 646If you use the option @option{-snapshot}, all disk images are
 647considered as read only. When sectors in written, they are written in
 648a temporary file created in @file{/tmp}. You can however force the
 649write back to the raw disk images by using the @code{commit} monitor
 650command (or @key{C-a s} in the serial console).
 651
 652@node vm_snapshots
 653@subsection VM snapshots
 654
 655VM snapshots are snapshots of the complete virtual machine including
 656CPU state, RAM, device state and the content of all the writable
 657disks. In order to use VM snapshots, you must have at least one non
 658removable and writable block device using the @code{qcow2} disk image
 659format. Normally this device is the first virtual hard drive.
 660
 661Use the monitor command @code{savevm} to create a new VM snapshot or
 662replace an existing one. A human readable name can be assigned to each
 663snapshot in addition to its numerical ID.
 664
 665Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
 666a VM snapshot. @code{info snapshots} lists the available snapshots
 667with their associated information:
 668
 669@example
 670(qemu) info snapshots
 671Snapshot devices: hda
 672Snapshot list (from hda):
 673ID        TAG                 VM SIZE                DATE       VM CLOCK
 6741         start                   41M 2006-08-06 12:38:02   00:00:14.954
 6752                                 40M 2006-08-06 12:43:29   00:00:18.633
 6763         msys                    40M 2006-08-06 12:44:04   00:00:23.514
 677@end example
 678
 679A VM snapshot is made of a VM state info (its size is shown in
 680@code{info snapshots}) and a snapshot of every writable disk image.
 681The VM state info is stored in the first @code{qcow2} non removable
 682and writable block device. The disk image snapshots are stored in
 683every disk image. The size of a snapshot in a disk image is difficult
 684to evaluate and is not shown by @code{info snapshots} because the
 685associated disk sectors are shared among all the snapshots to save
 686disk space (otherwise each snapshot would need a full copy of all the
 687disk images).
 688
 689When using the (unrelated) @code{-snapshot} option
 690(@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
 691but they are deleted as soon as you exit QEMU.
 692
 693VM snapshots currently have the following known limitations:
 694@itemize
 695@item
 696They cannot cope with removable devices if they are removed or
 697inserted after a snapshot is done.
 698@item
 699A few device drivers still have incomplete snapshot support so their
 700state is not saved or restored properly (in particular USB).
 701@end itemize
 702
 703@node qemu_img_invocation
 704@subsection @code{qemu-img} Invocation
 705
 706@include qemu-img.texi
 707
 708@node qemu_nbd_invocation
 709@subsection @code{qemu-nbd} Invocation
 710
 711@include qemu-nbd.texi
 712
 713@include docs/qemu-block-drivers.texi
 714
 715@node pcsys_network
 716@section Network emulation
 717
 718QEMU can simulate several network cards (e.g. PCI or ISA cards on the PC
 719target) and can connect them to a network backend on the host or an emulated
 720hub. The various host network backends can either be used to connect the NIC of
 721the guest to a real network (e.g. by using a TAP devices or the non-privileged
 722user mode network stack), or to other guest instances running in another QEMU
 723process (e.g. by using the socket host network backend).
 724
 725@subsection Using TAP network interfaces
 726
 727This is the standard way to connect QEMU to a real network. QEMU adds
 728a virtual network device on your host (called @code{tapN}), and you
 729can then configure it as if it was a real ethernet card.
 730
 731@subsubsection Linux host
 732
 733As an example, you can download the @file{linux-test-xxx.tar.gz}
 734archive and copy the script @file{qemu-ifup} in @file{/etc} and
 735configure properly @code{sudo} so that the command @code{ifconfig}
 736contained in @file{qemu-ifup} can be executed as root. You must verify
 737that your host kernel supports the TAP network interfaces: the
 738device @file{/dev/net/tun} must be present.
 739
 740See @ref{sec_invocation} to have examples of command lines using the
 741TAP network interfaces.
 742
 743@subsubsection Windows host
 744
 745There is a virtual ethernet driver for Windows 2000/XP systems, called
 746TAP-Win32. But it is not included in standard QEMU for Windows,
 747so you will need to get it separately. It is part of OpenVPN package,
 748so download OpenVPN from : @url{https://openvpn.net/}.
 749
 750@subsection Using the user mode network stack
 751
 752By using the option @option{-net user} (default configuration if no
 753@option{-net} option is specified), QEMU uses a completely user mode
 754network stack (you don't need root privilege to use the virtual
 755network). The virtual network configuration is the following:
 756
 757@example
 758
 759     guest (10.0.2.15)  <------>  Firewall/DHCP server <-----> Internet
 760                           |          (10.0.2.2)
 761                           |
 762                           ---->  DNS server (10.0.2.3)
 763                           |
 764                           ---->  SMB server (10.0.2.4)
 765@end example
 766
 767The QEMU VM behaves as if it was behind a firewall which blocks all
 768incoming connections. You can use a DHCP client to automatically
 769configure the network in the QEMU VM. The DHCP server assign addresses
 770to the hosts starting from 10.0.2.15.
 771
 772In order to check that the user mode network is working, you can ping
 773the address 10.0.2.2 and verify that you got an address in the range
 77410.0.2.x from the QEMU virtual DHCP server.
 775
 776Note that ICMP traffic in general does not work with user mode networking.
 777@code{ping}, aka. ICMP echo, to the local router (10.0.2.2) shall work,
 778however. If you're using QEMU on Linux >= 3.0, it can use unprivileged ICMP
 779ping sockets to allow @code{ping} to the Internet. The host admin has to set
 780the ping_group_range in order to grant access to those sockets. To allow ping
 781for GID 100 (usually users group):
 782
 783@example
 784echo 100 100 > /proc/sys/net/ipv4/ping_group_range
 785@end example
 786
 787When using the built-in TFTP server, the router is also the TFTP
 788server.
 789
 790When using the @option{'-netdev user,hostfwd=...'} option, TCP or UDP
 791connections can be redirected from the host to the guest. It allows for
 792example to redirect X11, telnet or SSH connections.
 793
 794@subsection Hubs
 795
 796QEMU can simulate several hubs. A hub can be thought of as a virtual connection
 797between several network devices. These devices can be for example QEMU virtual
 798ethernet cards or virtual Host ethernet devices (TAP devices). You can connect
 799guest NICs or host network backends to such a hub using the @option{-netdev
 800hubport} or @option{-nic hubport} options. The legacy @option{-net} option
 801also connects the given device to the emulated hub with ID 0 (i.e. the default
 802hub) unless you specify a netdev with @option{-net nic,netdev=xxx} here.
 803
 804@subsection Connecting emulated networks between QEMU instances
 805
 806Using the @option{-netdev socket} (or @option{-nic socket} or
 807@option{-net socket}) option, it is possible to create emulated
 808networks that span several QEMU instances.
 809See the description of the @option{-netdev socket} option in the
 810@ref{sec_invocation,,Invocation chapter} to have a basic example.
 811
 812@node pcsys_other_devs
 813@section Other Devices
 814
 815@subsection Inter-VM Shared Memory device
 816
 817On Linux hosts, a shared memory device is available.  The basic syntax
 818is:
 819
 820@example
 821qemu-system-x86_64 -device ivshmem-plain,memdev=@var{hostmem}
 822@end example
 823
 824where @var{hostmem} names a host memory backend.  For a POSIX shared
 825memory backend, use something like
 826
 827@example
 828-object memory-backend-file,size=1M,share,mem-path=/dev/shm/ivshmem,id=@var{hostmem}
 829@end example
 830
 831If desired, interrupts can be sent between guest VMs accessing the same shared
 832memory region.  Interrupt support requires using a shared memory server and
 833using a chardev socket to connect to it.  The code for the shared memory server
 834is qemu.git/contrib/ivshmem-server.  An example syntax when using the shared
 835memory server is:
 836
 837@example
 838# First start the ivshmem server once and for all
 839ivshmem-server -p @var{pidfile} -S @var{path} -m @var{shm-name} -l @var{shm-size} -n @var{vectors}
 840
 841# Then start your qemu instances with matching arguments
 842qemu-system-x86_64 -device ivshmem-doorbell,vectors=@var{vectors},chardev=@var{id}
 843                 -chardev socket,path=@var{path},id=@var{id}
 844@end example
 845
 846When using the server, the guest will be assigned a VM ID (>=0) that allows guests
 847using the same server to communicate via interrupts.  Guests can read their
 848VM ID from a device register (see ivshmem-spec.txt).
 849
 850@subsubsection Migration with ivshmem
 851
 852With device property @option{master=on}, the guest will copy the shared
 853memory on migration to the destination host.  With @option{master=off},
 854the guest will not be able to migrate with the device attached.  In the
 855latter case, the device should be detached and then reattached after
 856migration using the PCI hotplug support.
 857
 858At most one of the devices sharing the same memory can be master.  The
 859master must complete migration before you plug back the other devices.
 860
 861@subsubsection ivshmem and hugepages
 862
 863Instead of specifying the <shm size> using POSIX shm, you may specify
 864a memory backend that has hugepage support:
 865
 866@example
 867qemu-system-x86_64 -object memory-backend-file,size=1G,mem-path=/dev/hugepages/my-shmem-file,share,id=mb1
 868                 -device ivshmem-plain,memdev=mb1
 869@end example
 870
 871ivshmem-server also supports hugepages mount points with the
 872@option{-m} memory path argument.
 873
 874@node direct_linux_boot
 875@section Direct Linux Boot
 876
 877This section explains how to launch a Linux kernel inside QEMU without
 878having to make a full bootable image. It is very useful for fast Linux
 879kernel testing.
 880
 881The syntax is:
 882@example
 883qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
 884@end example
 885
 886Use @option{-kernel} to provide the Linux kernel image and
 887@option{-append} to give the kernel command line arguments. The
 888@option{-initrd} option can be used to provide an INITRD image.
 889
 890When using the direct Linux boot, a disk image for the first hard disk
 891@file{hda} is required because its boot sector is used to launch the
 892Linux kernel.
 893
 894If you do not need graphical output, you can disable it and redirect
 895the virtual serial port and the QEMU monitor to the console with the
 896@option{-nographic} option. The typical command line is:
 897@example
 898qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
 899                 -append "root=/dev/hda console=ttyS0" -nographic
 900@end example
 901
 902Use @key{Ctrl-a c} to switch between the serial console and the
 903monitor (@pxref{pcsys_keys}).
 904
 905@node pcsys_usb
 906@section USB emulation
 907
 908QEMU can emulate a PCI UHCI, OHCI, EHCI or XHCI USB controller. You can
 909plug virtual USB devices or real host USB devices (only works with certain
 910host operating systems). QEMU will automatically create and connect virtual
 911USB hubs as necessary to connect multiple USB devices.
 912
 913@menu
 914* usb_devices::
 915* host_usb_devices::
 916@end menu
 917@node usb_devices
 918@subsection Connecting USB devices
 919
 920USB devices can be connected with the @option{-device usb-...} command line
 921option or the @code{device_add} monitor command. Available devices are:
 922
 923@table @code
 924@item usb-mouse
 925Virtual Mouse.  This will override the PS/2 mouse emulation when activated.
 926@item usb-tablet
 927Pointer device that uses absolute coordinates (like a touchscreen).
 928This means QEMU is able to report the mouse position without having
 929to grab the mouse.  Also overrides the PS/2 mouse emulation when activated.
 930@item usb-storage,drive=@var{drive_id}
 931Mass storage device backed by @var{drive_id} (@pxref{disk_images})
 932@item usb-uas
 933USB attached SCSI device, see
 934@url{https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/usb-storage.txt,usb-storage.txt}
 935for details
 936@item usb-bot
 937Bulk-only transport storage device, see
 938@url{https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/usb-storage.txt,usb-storage.txt}
 939for details here, too
 940@item usb-mtp,x-root=@var{dir}
 941Media transfer protocol device, using @var{dir} as root of the file tree
 942that is presented to the guest.
 943@item usb-host,hostbus=@var{bus},hostaddr=@var{addr}
 944Pass through the host device identified by @var{bus} and @var{addr}
 945@item usb-host,vendorid=@var{vendor},productid=@var{product}
 946Pass through the host device identified by @var{vendor} and @var{product} ID
 947@item usb-wacom-tablet
 948Virtual Wacom PenPartner tablet.  This device is similar to the @code{tablet}
 949above but it can be used with the tslib library because in addition to touch
 950coordinates it reports touch pressure.
 951@item usb-kbd
 952Standard USB keyboard.  Will override the PS/2 keyboard (if present).
 953@item usb-serial,chardev=@var{id}
 954Serial converter. This emulates an FTDI FT232BM chip connected to host character
 955device @var{id}.
 956@item usb-braille,chardev=@var{id}
 957Braille device.  This will use BrlAPI to display the braille output on a real
 958or fake device referenced by @var{id}.
 959@item usb-net[,netdev=@var{id}]
 960Network adapter that supports CDC ethernet and RNDIS protocols.  @var{id}
 961specifies a netdev defined with @code{-netdev @dots{},id=@var{id}}.
 962For instance, user-mode networking can be used with
 963@example
 964qemu-system-i386 [...] -netdev user,id=net0 -device usb-net,netdev=net0
 965@end example
 966@item usb-ccid
 967Smartcard reader device
 968@item usb-audio
 969USB audio device
 970@item usb-bt-dongle
 971Bluetooth dongle for the transport layer of HCI. It is connected to HCI
 972scatternet 0 by default (corresponds to @code{-bt hci,vlan=0}).
 973Note that the syntax for the @code{-device usb-bt-dongle} option is not as
 974useful yet as it was with the legacy @code{-usbdevice} option. So to
 975configure an USB bluetooth device, you might need to use
 976"@code{-usbdevice bt}[:@var{hci-type}]" instead. This configures a
 977bluetooth dongle whose type is specified in the same format as with
 978the @option{-bt hci} option, @pxref{bt-hcis,,allowed HCI types}.  If
 979no type is given, the HCI logic corresponds to @code{-bt hci,vlan=0}.
 980This USB device implements the USB Transport Layer of HCI.  Example
 981usage:
 982@example
 983@command{qemu-system-i386} [...@var{OPTIONS}...] @option{-usbdevice} bt:hci,vlan=3 @option{-bt} device:keyboard,vlan=3
 984@end example
 985@end table
 986
 987@node host_usb_devices
 988@subsection Using host USB devices on a Linux host
 989
 990WARNING: this is an experimental feature. QEMU will slow down when
 991using it. USB devices requiring real time streaming (i.e. USB Video
 992Cameras) are not supported yet.
 993
 994@enumerate
 995@item If you use an early Linux 2.4 kernel, verify that no Linux driver
 996is actually using the USB device. A simple way to do that is simply to
 997disable the corresponding kernel module by renaming it from @file{mydriver.o}
 998to @file{mydriver.o.disabled}.
 999
1000@item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1001@example
1002ls /proc/bus/usb
1003001  devices  drivers
1004@end example
1005
1006@item Since only root can access to the USB devices directly, you can either launch QEMU as root or change the permissions of the USB devices you want to use. For testing, the following suffices:
1007@example
1008chown -R myuid /proc/bus/usb
1009@end example
1010
1011@item Launch QEMU and do in the monitor:
1012@example
1013info usbhost
1014  Device 1.2, speed 480 Mb/s
1015    Class 00: USB device 1234:5678, USB DISK
1016@end example
1017You should see the list of the devices you can use (Never try to use
1018hubs, it won't work).
1019
1020@item Add the device in QEMU by using:
1021@example
1022device_add usb-host,vendorid=0x1234,productid=0x5678
1023@end example
1024
1025Normally the guest OS should report that a new USB device is plugged.
1026You can use the option @option{-device usb-host,...} to do the same.
1027
1028@item Now you can try to use the host USB device in QEMU.
1029
1030@end enumerate
1031
1032When relaunching QEMU, you may have to unplug and plug again the USB
1033device to make it work again (this is a bug).
1034
1035@node vnc_security
1036@section VNC security
1037
1038The VNC server capability provides access to the graphical console
1039of the guest VM across the network. This has a number of security
1040considerations depending on the deployment scenarios.
1041
1042@menu
1043* vnc_sec_none::
1044* vnc_sec_password::
1045* vnc_sec_certificate::
1046* vnc_sec_certificate_verify::
1047* vnc_sec_certificate_pw::
1048* vnc_sec_sasl::
1049* vnc_sec_certificate_sasl::
1050* vnc_setup_sasl::
1051@end menu
1052@node vnc_sec_none
1053@subsection Without passwords
1054
1055The simplest VNC server setup does not include any form of authentication.
1056For this setup it is recommended to restrict it to listen on a UNIX domain
1057socket only. For example
1058
1059@example
1060qemu-system-i386 [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
1061@end example
1062
1063This ensures that only users on local box with read/write access to that
1064path can access the VNC server. To securely access the VNC server from a
1065remote machine, a combination of netcat+ssh can be used to provide a secure
1066tunnel.
1067
1068@node vnc_sec_password
1069@subsection With passwords
1070
1071The VNC protocol has limited support for password based authentication. Since
1072the protocol limits passwords to 8 characters it should not be considered
1073to provide high security. The password can be fairly easily brute-forced by
1074a client making repeat connections. For this reason, a VNC server using password
1075authentication should be restricted to only listen on the loopback interface
1076or UNIX domain sockets. Password authentication is not supported when operating
1077in FIPS 140-2 compliance mode as it requires the use of the DES cipher. Password
1078authentication is requested with the @code{password} option, and then once QEMU
1079is running the password is set with the monitor. Until the monitor is used to
1080set the password all clients will be rejected.
1081
1082@example
1083qemu-system-i386 [...OPTIONS...] -vnc :1,password -monitor stdio
1084(qemu) change vnc password
1085Password: ********
1086(qemu)
1087@end example
1088
1089@node vnc_sec_certificate
1090@subsection With x509 certificates
1091
1092The QEMU VNC server also implements the VeNCrypt extension allowing use of
1093TLS for encryption of the session, and x509 certificates for authentication.
1094The use of x509 certificates is strongly recommended, because TLS on its
1095own is susceptible to man-in-the-middle attacks. Basic x509 certificate
1096support provides a secure session, but no authentication. This allows any
1097client to connect, and provides an encrypted session.
1098
1099@example
1100qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio
1101@end example
1102
1103In the above example @code{/etc/pki/qemu} should contain at least three files,
1104@code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged
1105users will want to use a private directory, for example @code{$HOME/.pki/qemu}.
1106NB the @code{server-key.pem} file should be protected with file mode 0600 to
1107only be readable by the user owning it.
1108
1109@node vnc_sec_certificate_verify
1110@subsection With x509 certificates and client verification
1111
1112Certificates can also provide a means to authenticate the client connecting.
1113The server will request that the client provide a certificate, which it will
1114then validate against the CA certificate. This is a good choice if deploying
1115in an environment with a private internal certificate authority.
1116
1117@example
1118qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
1119@end example
1120
1121
1122@node vnc_sec_certificate_pw
1123@subsection With x509 certificates, client verification and passwords
1124
1125Finally, the previous method can be combined with VNC password authentication
1126to provide two layers of authentication for clients.
1127
1128@example
1129qemu-system-i386 [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
1130(qemu) change vnc password
1131Password: ********
1132(qemu)
1133@end example
1134
1135
1136@node vnc_sec_sasl
1137@subsection With SASL authentication
1138
1139The SASL authentication method is a VNC extension, that provides an
1140easily extendable, pluggable authentication method. This allows for
1141integration with a wide range of authentication mechanisms, such as
1142PAM, GSSAPI/Kerberos, LDAP, SQL databases, one-time keys and more.
1143The strength of the authentication depends on the exact mechanism
1144configured. If the chosen mechanism also provides a SSF layer, then
1145it will encrypt the datastream as well.
1146
1147Refer to the later docs on how to choose the exact SASL mechanism
1148used for authentication, but assuming use of one supporting SSF,
1149then QEMU can be launched with:
1150
1151@example
1152qemu-system-i386 [...OPTIONS...] -vnc :1,sasl -monitor stdio
1153@end example
1154
1155@node vnc_sec_certificate_sasl
1156@subsection With x509 certificates and SASL authentication
1157
1158If the desired SASL authentication mechanism does not supported
1159SSF layers, then it is strongly advised to run it in combination
1160with TLS and x509 certificates. This provides securely encrypted
1161data stream, avoiding risk of compromising of the security
1162credentials. This can be enabled, by combining the 'sasl' option
1163with the aforementioned TLS + x509 options:
1164
1165@example
1166qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509,sasl -monitor stdio
1167@end example
1168
1169@node vnc_setup_sasl
1170
1171@subsection Configuring SASL mechanisms
1172
1173The following documentation assumes use of the Cyrus SASL implementation on a
1174Linux host, but the principles should apply to any other SASL implementation
1175or host. When SASL is enabled, the mechanism configuration will be loaded from
1176system default SASL service config /etc/sasl2/qemu.conf. If running QEMU as an
1177unprivileged user, an environment variable SASL_CONF_PATH can be used to make
1178it search alternate locations for the service config file.
1179
1180If the TLS option is enabled for VNC, then it will provide session encryption,
1181otherwise the SASL mechanism will have to provide encryption. In the latter
1182case the list of possible plugins that can be used is drastically reduced. In
1183fact only the GSSAPI SASL mechanism provides an acceptable level of security
1184by modern standards. Previous versions of QEMU referred to the DIGEST-MD5
1185mechanism, however, it has multiple serious flaws described in detail in
1186RFC 6331 and thus should never be used any more. The SCRAM-SHA-1 mechanism
1187provides a simple username/password auth facility similar to DIGEST-MD5, but
1188does not support session encryption, so can only be used in combination with
1189TLS.
1190
1191When not using TLS the recommended configuration is
1192
1193@example
1194mech_list: gssapi
1195keytab: /etc/qemu/krb5.tab
1196@end example
1197
1198This says to use the 'GSSAPI' mechanism with the Kerberos v5 protocol, with
1199the server principal stored in /etc/qemu/krb5.tab. For this to work the
1200administrator of your KDC must generate a Kerberos principal for the server,
1201with a name of 'qemu/somehost.example.com@@EXAMPLE.COM' replacing
1202'somehost.example.com' with the fully qualified host name of the machine
1203running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.
1204
1205When using TLS, if username+password authentication is desired, then a
1206reasonable configuration is
1207
1208@example
1209mech_list: scram-sha-1
1210sasldb_path: /etc/qemu/passwd.db
1211@end example
1212
1213The @code{saslpasswd2} program can be used to populate the @code{passwd.db}
1214file with accounts.
1215
1216Other SASL configurations will be left as an exercise for the reader. Note that
1217all mechanisms, except GSSAPI, should be combined with use of TLS to ensure a
1218secure data channel.
1219
1220
1221@node network_tls
1222@section TLS setup for network services
1223
1224Almost all network services in QEMU have the ability to use TLS for
1225session data encryption, along with x509 certificates for simple
1226client authentication. What follows is a description of how to
1227generate certificates suitable for usage with QEMU, and applies to
1228the VNC server, character devices with the TCP backend, NBD server
1229and client, and migration server and client.
1230
1231At a high level, QEMU requires certificates and private keys to be
1232provided in PEM format. Aside from the core fields, the certificates
1233should include various extension data sets, including v3 basic
1234constraints data, key purpose, key usage and subject alt name.
1235
1236The GnuTLS package includes a command called @code{certtool} which can
1237be used to easily generate certificates and keys in the required format
1238with expected data present. Alternatively a certificate management
1239service may be used.
1240
1241At a minimum it is necessary to setup a certificate authority, and
1242issue certificates to each server. If using x509 certificates for
1243authentication, then each client will also need to be issued a
1244certificate.
1245
1246Assuming that the QEMU network services will only ever be exposed to
1247clients on a private intranet, there is no need to use a commercial
1248certificate authority to create certificates. A self-signed CA is
1249sufficient, and in fact likely to be more secure since it removes
1250the ability of malicious 3rd parties to trick the CA into mis-issuing
1251certs for impersonating your services. The only likely exception
1252where a commercial CA might be desirable is if enabling the VNC
1253websockets server and exposing it directly to remote browser clients.
1254In such a case it might be useful to use a commercial CA to avoid
1255needing to install custom CA certs in the web browsers.
1256
1257The recommendation is for the server to keep its certificates in either
1258@code{/etc/pki/qemu} or for unprivileged users in @code{$HOME/.pki/qemu}.
1259
1260@menu
1261* tls_generate_ca::
1262* tls_generate_server::
1263* tls_generate_client::
1264* tls_creds_setup::
1265* tls_psk::
1266@end menu
1267@node tls_generate_ca
1268@subsection Setup the Certificate Authority
1269
1270This step only needs to be performed once per organization / organizational
1271unit. First the CA needs a private key. This key must be kept VERY secret
1272and secure. If this key is compromised the entire trust chain of the certificates
1273issued with it is lost.
1274
1275@example
1276# certtool --generate-privkey > ca-key.pem
1277@end example
1278
1279To generate a self-signed certificate requires one core piece of information,
1280the name of the organization. A template file @code{ca.info} should be
1281populated with the desired data to avoid having to deal with interactive
1282prompts from certtool:
1283@example
1284# cat > ca.info <<EOF
1285cn = Name of your organization
1286ca
1287cert_signing_key
1288EOF
1289# certtool --generate-self-signed \
1290           --load-privkey ca-key.pem
1291           --template ca.info \
1292           --outfile ca-cert.pem
1293@end example
1294
1295The @code{ca} keyword in the template sets the v3 basic constraints extension
1296to indicate this certificate is for a CA, while @code{cert_signing_key} sets
1297the key usage extension to indicate this will be used for signing other keys.
1298The generated @code{ca-cert.pem} file should be copied to all servers and
1299clients wishing to utilize TLS support in the VNC server. The @code{ca-key.pem}
1300must not be disclosed/copied anywhere except the host responsible for issuing
1301certificates.
1302
1303@node tls_generate_server
1304@subsection Issuing server certificates
1305
1306Each server (or host) needs to be issued with a key and certificate. When connecting
1307the certificate is sent to the client which validates it against the CA certificate.
1308The core pieces of information for a server certificate are the hostnames and/or IP
1309addresses that will be used by clients when connecting. The hostname / IP address
1310that the client specifies when connecting will be validated against the hostname(s)
1311and IP address(es) recorded in the server certificate, and if no match is found
1312the client will close the connection.
1313
1314Thus it is recommended that the server certificate include both the fully qualified
1315and unqualified hostnames. If the server will have permanently assigned IP address(es),
1316and clients are likely to use them when connecting, they may also be included in the
1317certificate. Both IPv4 and IPv6 addresses are supported. Historically certificates
1318only included 1 hostname in the @code{CN} field, however, usage of this field for
1319validation is now deprecated. Instead modern TLS clients will validate against the
1320Subject Alt Name extension data, which allows for multiple entries. In the future
1321usage of the @code{CN} field may be discontinued entirely, so providing SAN
1322extension data is strongly recommended.
1323
1324On the host holding the CA, create template files containing the information
1325for each server, and use it to issue server certificates.
1326
1327@example
1328# cat > server-hostNNN.info <<EOF
1329organization = Name  of your organization
1330cn = hostNNN.foo.example.com
1331dns_name = hostNNN
1332dns_name = hostNNN.foo.example.com
1333ip_address = 10.0.1.87
1334ip_address = 192.8.0.92
1335ip_address = 2620:0:cafe::87
1336ip_address = 2001:24::92
1337tls_www_server
1338encryption_key
1339signing_key
1340EOF
1341# certtool --generate-privkey > server-hostNNN-key.pem
1342# certtool --generate-certificate \
1343           --load-ca-certificate ca-cert.pem \
1344           --load-ca-privkey ca-key.pem \
1345           --load-privkey server-hostNNN-key.pem \
1346           --template server-hostNNN.info \
1347           --outfile server-hostNNN-cert.pem
1348@end example
1349
1350The @code{dns_name} and @code{ip_address} fields in the template are setting
1351the subject alt name extension data. The @code{tls_www_server} keyword is the
1352key purpose extension to indicate this certificate is intended for usage in
1353a web server. Although QEMU network services are not in fact HTTP servers
1354(except for VNC websockets), setting this key purpose is still recommended.
1355The @code{encryption_key} and @code{signing_key} keyword is the key usage
1356extension to indicate this certificate is intended for usage in the data
1357session.
1358
1359The @code{server-hostNNN-key.pem} and @code{server-hostNNN-cert.pem} files
1360should now be securely copied to the server for which they were generated,
1361and renamed to @code{server-key.pem} and @code{server-cert.pem} when added
1362to the @code{/etc/pki/qemu} directory on the target host. The @code{server-key.pem}
1363file is security sensitive and should be kept protected with file mode 0600
1364to prevent disclosure.
1365
1366@node tls_generate_client
1367@subsection Issuing client certificates
1368
1369The QEMU x509 TLS credential setup defaults to enabling client verification
1370using certificates, providing a simple authentication mechanism. If this
1371default is used, each client also needs to be issued a certificate. The client
1372certificate contains enough metadata to uniquely identify the client with the
1373scope of the certificate authority. The client certificate would typically
1374include fields for organization, state, city, building, etc.
1375
1376Once again on the host holding the CA, create template files containing the
1377information for each client, and use it to issue client certificates.
1378
1379
1380@example
1381# cat > client-hostNNN.info <<EOF
1382country = GB
1383state = London
1384locality = City Of London
1385organization = Name of your organization
1386cn = hostNNN.foo.example.com
1387tls_www_client
1388encryption_key
1389signing_key
1390EOF
1391# certtool --generate-privkey > client-hostNNN-key.pem
1392# certtool --generate-certificate \
1393           --load-ca-certificate ca-cert.pem \
1394           --load-ca-privkey ca-key.pem \
1395           --load-privkey client-hostNNN-key.pem \
1396           --template client-hostNNN.info \
1397           --outfile client-hostNNN-cert.pem
1398@end example
1399
1400The subject alt name extension data is not required for clients, so the
1401the @code{dns_name} and @code{ip_address} fields are not included.
1402The @code{tls_www_client} keyword is the key purpose extension to indicate
1403this certificate is intended for usage in a web client. Although QEMU
1404network clients are not in fact HTTP clients, setting this key purpose is
1405still recommended. The @code{encryption_key} and @code{signing_key} keyword
1406is the key usage extension to indicate this certificate is intended for
1407usage in the data session.
1408
1409The @code{client-hostNNN-key.pem} and @code{client-hostNNN-cert.pem} files
1410should now be securely copied to the client for which they were generated,
1411and renamed to @code{client-key.pem} and @code{client-cert.pem} when added
1412to the @code{/etc/pki/qemu} directory on the target host. The @code{client-key.pem}
1413file is security sensitive and should be kept protected with file mode 0600
1414to prevent disclosure.
1415
1416If a single host is going to be using TLS in both a client and server
1417role, it is possible to create a single certificate to cover both roles.
1418This would be quite common for the migration and NBD services, where a
1419QEMU process will be started by accepting a TLS protected incoming migration,
1420and later itself be migrated out to another host. To generate a single
1421certificate, simply include the template data from both the client and server
1422instructions in one.
1423
1424@example
1425# cat > both-hostNNN.info <<EOF
1426country = GB
1427state = London
1428locality = City Of London
1429organization = Name of your organization
1430cn = hostNNN.foo.example.com
1431dns_name = hostNNN
1432dns_name = hostNNN.foo.example.com
1433ip_address = 10.0.1.87
1434ip_address = 192.8.0.92
1435ip_address = 2620:0:cafe::87
1436ip_address = 2001:24::92
1437tls_www_server
1438tls_www_client
1439encryption_key
1440signing_key
1441EOF
1442# certtool --generate-privkey > both-hostNNN-key.pem
1443# certtool --generate-certificate \
1444           --load-ca-certificate ca-cert.pem \
1445           --load-ca-privkey ca-key.pem \
1446           --load-privkey both-hostNNN-key.pem \
1447           --template both-hostNNN.info \
1448           --outfile both-hostNNN-cert.pem
1449@end example
1450
1451When copying the PEM files to the target host, save them twice,
1452once as @code{server-cert.pem} and @code{server-key.pem}, and
1453again as @code{client-cert.pem} and @code{client-key.pem}.
1454
1455@node tls_creds_setup
1456@subsection TLS x509 credential configuration
1457
1458QEMU has a standard mechanism for loading x509 credentials that will be
1459used for network services and clients. It requires specifying the
1460@code{tls-creds-x509} class name to the @code{--object} command line
1461argument for the system emulators.  Each set of credentials loaded should
1462be given a unique string identifier via the @code{id} parameter. A single
1463set of TLS credentials can be used for multiple network backends, so VNC,
1464migration, NBD, character devices can all share the same credentials. Note,
1465however, that credentials for use in a client endpoint must be loaded
1466separately from those used in a server endpoint.
1467
1468When specifying the object, the @code{dir} parameters specifies which
1469directory contains the credential files. This directory is expected to
1470contain files with the names mentioned previously, @code{ca-cert.pem},
1471@code{server-key.pem}, @code{server-cert.pem}, @code{client-key.pem}
1472and @code{client-cert.pem} as appropriate. It is also possible to
1473include a set of pre-generated Diffie-Hellman (DH) parameters in a file
1474@code{dh-params.pem}, which can be created using the
1475@code{certtool --generate-dh-params} command. If omitted, QEMU will
1476dynamically generate DH parameters when loading the credentials.
1477
1478The @code{endpoint} parameter indicates whether the credentials will
1479be used for a network client or server, and determines which PEM
1480files are loaded.
1481
1482The @code{verify} parameter determines whether x509 certificate
1483validation should be performed. This defaults to enabled, meaning
1484clients will always validate the server hostname against the
1485certificate subject alt name fields and/or CN field. It also
1486means that servers will request that clients provide a certificate
1487and validate them. Verification should never be turned off for
1488client endpoints, however, it may be turned off for server endpoints
1489if an alternative mechanism is used to authenticate clients. For
1490example, the VNC server can use SASL to authenticate clients
1491instead.
1492
1493To load server credentials with client certificate validation
1494enabled
1495
1496@example
1497$QEMU -object tls-creds-x509,id=tls0,dir=/etc/pki/qemu,endpoint=server
1498@end example
1499
1500while to load client credentials use
1501
1502@example
1503$QEMU -object tls-creds-x509,id=tls0,dir=/etc/pki/qemu,endpoint=client
1504@end example
1505
1506Network services which support TLS will all have a @code{tls-creds}
1507parameter which expects the ID of the TLS credentials object. For
1508example with VNC:
1509
1510@example
1511$QEMU -vnc 0.0.0.0:0,tls-creds=tls0
1512@end example
1513
1514@node tls_psk
1515@subsection TLS Pre-Shared Keys (PSK)
1516
1517Instead of using certificates, you may also use TLS Pre-Shared Keys
1518(TLS-PSK).  This can be simpler to set up than certificates but is
1519less scalable.
1520
1521Use the GnuTLS @code{psktool} program to generate a @code{keys.psk}
1522file containing one or more usernames and random keys:
1523
1524@example
1525mkdir -m 0700 /tmp/keys
1526psktool -u rich -p /tmp/keys/keys.psk
1527@end example
1528
1529TLS-enabled servers such as qemu-nbd can use this directory like so:
1530
1531@example
1532qemu-nbd \
1533  -t -x / \
1534  --object tls-creds-psk,id=tls0,endpoint=server,dir=/tmp/keys \
1535  --tls-creds tls0 \
1536  image.qcow2
1537@end example
1538
1539When connecting from a qemu-based client you must specify the
1540directory containing @code{keys.psk} and an optional @var{username}
1541(defaults to ``qemu''):
1542
1543@example
1544qemu-img info \
1545  --object tls-creds-psk,id=tls0,dir=/tmp/keys,username=rich,endpoint=client \
1546  --image-opts \
1547  file.driver=nbd,file.host=localhost,file.port=10809,file.tls-creds=tls0,file.export=/
1548@end example
1549
1550@node gdb_usage
1551@section GDB usage
1552
1553QEMU has a primitive support to work with gdb, so that you can do
1554'Ctrl-C' while the virtual machine is running and inspect its state.
1555
1556In order to use gdb, launch QEMU with the '-s' option. It will wait for a
1557gdb connection:
1558@example
1559qemu-system-i386 -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1560                    -append "root=/dev/hda"
1561Connected to host network interface: tun0
1562Waiting gdb connection on port 1234
1563@end example
1564
1565Then launch gdb on the 'vmlinux' executable:
1566@example
1567> gdb vmlinux
1568@end example
1569
1570In gdb, connect to QEMU:
1571@example
1572(gdb) target remote localhost:1234
1573@end example
1574
1575Then you can use gdb normally. For example, type 'c' to launch the kernel:
1576@example
1577(gdb) c
1578@end example
1579
1580Here are some useful tips in order to use gdb on system code:
1581
1582@enumerate
1583@item
1584Use @code{info reg} to display all the CPU registers.
1585@item
1586Use @code{x/10i $eip} to display the code at the PC position.
1587@item
1588Use @code{set architecture i8086} to dump 16 bit code. Then use
1589@code{x/10i $cs*16+$eip} to dump the code at the PC position.
1590@end enumerate
1591
1592Advanced debugging options:
1593
1594The default single stepping behavior is step with the IRQs and timer service routines off.  It is set this way because when gdb executes a single step it expects to advance beyond the current instruction.  With the IRQs and timer service routines on, a single step might jump into the one of the interrupt or exception vectors instead of executing the current instruction. This means you may hit the same breakpoint a number of times before executing the instruction gdb wants to have executed.  Because there are rare circumstances where you want to single step into an interrupt vector the behavior can be controlled from GDB.  There are three commands you can query and set the single step behavior:
1595@table @code
1596@item maintenance packet qqemu.sstepbits
1597
1598This will display the MASK bits used to control the single stepping IE:
1599@example
1600(gdb) maintenance packet qqemu.sstepbits
1601sending: "qqemu.sstepbits"
1602received: "ENABLE=1,NOIRQ=2,NOTIMER=4"
1603@end example
1604@item maintenance packet qqemu.sstep
1605
1606This will display the current value of the mask used when single stepping IE:
1607@example
1608(gdb) maintenance packet qqemu.sstep
1609sending: "qqemu.sstep"
1610received: "0x7"
1611@end example
1612@item maintenance packet Qqemu.sstep=HEX_VALUE
1613
1614This will change the single step mask, so if wanted to enable IRQs on the single step, but not timers, you would use:
1615@example
1616(gdb) maintenance packet Qqemu.sstep=0x5
1617sending: "qemu.sstep=0x5"
1618received: "OK"
1619@end example
1620@end table
1621
1622@node pcsys_os_specific
1623@section Target OS specific information
1624
1625@subsection Linux
1626
1627To have access to SVGA graphic modes under X11, use the @code{vesa} or
1628the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1629color depth in the guest and the host OS.
1630
1631When using a 2.6 guest Linux kernel, you should add the option
1632@code{clock=pit} on the kernel command line because the 2.6 Linux
1633kernels make very strict real time clock checks by default that QEMU
1634cannot simulate exactly.
1635
1636When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1637not activated because QEMU is slower with this patch. The QEMU
1638Accelerator Module is also much slower in this case. Earlier Fedora
1639Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this
1640patch by default. Newer kernels don't have it.
1641
1642@subsection Windows
1643
1644If you have a slow host, using Windows 95 is better as it gives the
1645best speed. Windows 2000 is also a good choice.
1646
1647@subsubsection SVGA graphic modes support
1648
1649QEMU emulates a Cirrus Logic GD5446 Video
1650card. All Windows versions starting from Windows 95 should recognize
1651and use this graphic card. For optimal performances, use 16 bit color
1652depth in the guest and the host OS.
1653
1654If you are using Windows XP as guest OS and if you want to use high
1655resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
16561280x1024x16), then you should use the VESA VBE virtual graphic card
1657(option @option{-std-vga}).
1658
1659@subsubsection CPU usage reduction
1660
1661Windows 9x does not correctly use the CPU HLT
1662instruction. The result is that it takes host CPU cycles even when
1663idle. You can install the utility from
1664@url{https://web.archive.org/web/20060212132151/http://www.user.cityline.ru/~maxamn/amnhltm.zip}
1665to solve this problem. Note that no such tool is needed for NT, 2000 or XP.
1666
1667@subsubsection Windows 2000 disk full problem
1668
1669Windows 2000 has a bug which gives a disk full problem during its
1670installation. When installing it, use the @option{-win2k-hack} QEMU
1671option to enable a specific workaround. After Windows 2000 is
1672installed, you no longer need this option (this option slows down the
1673IDE transfers).
1674
1675@subsubsection Windows 2000 shutdown
1676
1677Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1678can. It comes from the fact that Windows 2000 does not automatically
1679use the APM driver provided by the BIOS.
1680
1681In order to correct that, do the following (thanks to Struan
1682Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1683Add/Troubleshoot a device => Add a new device & Next => No, select the
1684hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1685(again) a few times. Now the driver is installed and Windows 2000 now
1686correctly instructs QEMU to shutdown at the appropriate moment.
1687
1688@subsubsection Share a directory between Unix and Windows
1689
1690See @ref{sec_invocation} about the help of the option
1691@option{'-netdev user,smb=...'}.
1692
1693@subsubsection Windows XP security problem
1694
1695Some releases of Windows XP install correctly but give a security
1696error when booting:
1697@example
1698A problem is preventing Windows from accurately checking the
1699license for this computer. Error code: 0x800703e6.
1700@end example
1701
1702The workaround is to install a service pack for XP after a boot in safe
1703mode. Then reboot, and the problem should go away. Since there is no
1704network while in safe mode, its recommended to download the full
1705installation of SP1 or SP2 and transfer that via an ISO or using the
1706vvfat block device ("-hdb fat:directory_which_holds_the_SP").
1707
1708@subsection MS-DOS and FreeDOS
1709
1710@subsubsection CPU usage reduction
1711
1712DOS does not correctly use the CPU HLT instruction. The result is that
1713it takes host CPU cycles even when idle. You can install the utility from
1714@url{https://web.archive.org/web/20051222085335/http://www.vmware.com/software/dosidle210.zip}
1715to solve this problem.
1716
1717@node QEMU System emulator for non PC targets
1718@chapter QEMU System emulator for non PC targets
1719
1720QEMU is a generic emulator and it emulates many non PC
1721machines. Most of the options are similar to the PC emulator. The
1722differences are mentioned in the following sections.
1723
1724@menu
1725* PowerPC System emulator::
1726* Sparc32 System emulator::
1727* Sparc64 System emulator::
1728* MIPS System emulator::
1729* ARM System emulator::
1730* ColdFire System emulator::
1731* Cris System emulator::
1732* Microblaze System emulator::
1733* SH4 System emulator::
1734* Xtensa System emulator::
1735@end menu
1736
1737@node PowerPC System emulator
1738@section PowerPC System emulator
1739@cindex system emulation (PowerPC)
1740
1741Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1742or PowerMac PowerPC system.
1743
1744QEMU emulates the following PowerMac peripherals:
1745
1746@itemize @minus
1747@item
1748UniNorth or Grackle PCI Bridge
1749@item
1750PCI VGA compatible card with VESA Bochs Extensions
1751@item
17522 PMAC IDE interfaces with hard disk and CD-ROM support
1753@item
1754NE2000 PCI adapters
1755@item
1756Non Volatile RAM
1757@item
1758VIA-CUDA with ADB keyboard and mouse.
1759@end itemize
1760
1761QEMU emulates the following PREP peripherals:
1762
1763@itemize @minus
1764@item
1765PCI Bridge
1766@item
1767PCI VGA compatible card with VESA Bochs Extensions
1768@item
17692 IDE interfaces with hard disk and CD-ROM support
1770@item
1771Floppy disk
1772@item
1773NE2000 network adapters
1774@item
1775Serial port
1776@item
1777PREP Non Volatile RAM
1778@item
1779PC compatible keyboard and mouse.
1780@end itemize
1781
1782QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
1783@url{http://perso.magic.fr/l_indien/OpenHackWare/index.htm}.
1784
1785Since version 0.9.1, QEMU uses OpenBIOS @url{https://www.openbios.org/}
1786for the g3beige and mac99 PowerMac machines. OpenBIOS is a free (GPL
1787v2) portable firmware implementation. The goal is to implement a 100%
1788IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.
1789
1790@c man begin OPTIONS
1791
1792The following options are specific to the PowerPC emulation:
1793
1794@table @option
1795
1796@item -g @var{W}x@var{H}[x@var{DEPTH}]
1797
1798Set the initial VGA graphic mode. The default is 800x600x32.
1799
1800@item -prom-env @var{string}
1801
1802Set OpenBIOS variables in NVRAM, for example:
1803
1804@example
1805qemu-system-ppc -prom-env 'auto-boot?=false' \
1806 -prom-env 'boot-device=hd:2,\yaboot' \
1807 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
1808@end example
1809
1810These variables are not used by Open Hack'Ware.
1811
1812@end table
1813
1814@c man end
1815
1816
1817More information is available at
1818@url{http://perso.magic.fr/l_indien/qemu-ppc/}.
1819
1820@node Sparc32 System emulator
1821@section Sparc32 System emulator
1822@cindex system emulation (Sparc32)
1823
1824Use the executable @file{qemu-system-sparc} to simulate the following
1825Sun4m architecture machines:
1826@itemize @minus
1827@item
1828SPARCstation 4
1829@item
1830SPARCstation 5
1831@item
1832SPARCstation 10
1833@item
1834SPARCstation 20
1835@item
1836SPARCserver 600MP
1837@item
1838SPARCstation LX
1839@item
1840SPARCstation Voyager
1841@item
1842SPARCclassic
1843@item
1844SPARCbook
1845@end itemize
1846
1847The emulation is somewhat complete. SMP up to 16 CPUs is supported,
1848but Linux limits the number of usable CPUs to 4.
1849
1850QEMU emulates the following sun4m peripherals:
1851
1852@itemize @minus
1853@item
1854IOMMU
1855@item
1856TCX or cgthree Frame buffer
1857@item
1858Lance (Am7990) Ethernet
1859@item
1860Non Volatile RAM M48T02/M48T08
1861@item
1862Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
1863and power/reset logic
1864@item
1865ESP SCSI controller with hard disk and CD-ROM support
1866@item
1867Floppy drive (not on SS-600MP)
1868@item
1869CS4231 sound device (only on SS-5, not working yet)
1870@end itemize
1871
1872The number of peripherals is fixed in the architecture.  Maximum
1873memory size depends on the machine type, for SS-5 it is 256MB and for
1874others 2047MB.
1875
1876Since version 0.8.2, QEMU uses OpenBIOS
1877@url{https://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
1878firmware implementation. The goal is to implement a 100% IEEE
18791275-1994 (referred to as Open Firmware) compliant firmware.
1880
1881A sample Linux 2.6 series kernel and ram disk image are available on
1882the QEMU web site. There are still issues with NetBSD and OpenBSD, but
1883most kernel versions work. Please note that currently older Solaris kernels
1884don't work probably due to interface issues between OpenBIOS and
1885Solaris.
1886
1887@c man begin OPTIONS
1888
1889The following options are specific to the Sparc32 emulation:
1890
1891@table @option
1892
1893@item -g @var{W}x@var{H}x[x@var{DEPTH}]
1894
1895Set the initial graphics mode. For TCX, the default is 1024x768x8 with the
1896option of 1024x768x24. For cgthree, the default is 1024x768x8 with the option
1897of 1152x900x8 for people who wish to use OBP.
1898
1899@item -prom-env @var{string}
1900
1901Set OpenBIOS variables in NVRAM, for example:
1902
1903@example
1904qemu-system-sparc -prom-env 'auto-boot?=false' \
1905 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
1906@end example
1907
1908@item -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic] [|SPARCbook]
1909
1910Set the emulated machine type. Default is SS-5.
1911
1912@end table
1913
1914@c man end
1915
1916@node Sparc64 System emulator
1917@section Sparc64 System emulator
1918@cindex system emulation (Sparc64)
1919
1920Use the executable @file{qemu-system-sparc64} to simulate a Sun4u
1921(UltraSPARC PC-like machine), Sun4v (T1 PC-like machine), or generic
1922Niagara (T1) machine. The Sun4u emulator is mostly complete, being
1923able to run Linux, NetBSD and OpenBSD in headless (-nographic) mode. The
1924Sun4v emulator is still a work in progress.
1925
1926The Niagara T1 emulator makes use of firmware and OS binaries supplied in the S10image/ directory
1927of the OpenSPARC T1 project @url{http://download.oracle.com/technetwork/systems/opensparc/OpenSPARCT1_Arch.1.5.tar.bz2}
1928and is able to boot the disk.s10hw2 Solaris image.
1929@example
1930qemu-system-sparc64 -M niagara -L /path-to/S10image/ \
1931                    -nographic -m 256 \
1932                    -drive if=pflash,readonly=on,file=/S10image/disk.s10hw2
1933@end example
1934
1935
1936QEMU emulates the following peripherals:
1937
1938@itemize @minus
1939@item
1940UltraSparc IIi APB PCI Bridge
1941@item
1942PCI VGA compatible card with VESA Bochs Extensions
1943@item
1944PS/2 mouse and keyboard
1945@item
1946Non Volatile RAM M48T59
1947@item
1948PC-compatible serial ports
1949@item
19502 PCI IDE interfaces with hard disk and CD-ROM support
1951@item
1952Floppy disk
1953@end itemize
1954
1955@c man begin OPTIONS
1956
1957The following options are specific to the Sparc64 emulation:
1958
1959@table @option
1960
1961@item -prom-env @var{string}
1962
1963Set OpenBIOS variables in NVRAM, for example:
1964
1965@example
1966qemu-system-sparc64 -prom-env 'auto-boot?=false'
1967@end example
1968
1969@item -M [sun4u|sun4v|niagara]
1970
1971Set the emulated machine type. The default is sun4u.
1972
1973@end table
1974
1975@c man end
1976
1977@node MIPS System emulator
1978@section MIPS System emulator
1979@cindex system emulation (MIPS)
1980
1981Four executables cover simulation of 32 and 64-bit MIPS systems in
1982both endian options, @file{qemu-system-mips}, @file{qemu-system-mipsel}
1983@file{qemu-system-mips64} and @file{qemu-system-mips64el}.
1984Five different machine types are emulated:
1985
1986@itemize @minus
1987@item
1988A generic ISA PC-like machine "mips"
1989@item
1990The MIPS Malta prototype board "malta"
1991@item
1992An ACER Pica "pica61". This machine needs the 64-bit emulator.
1993@item
1994MIPS emulator pseudo board "mipssim"
1995@item
1996A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator.
1997@end itemize
1998
1999The generic emulation is supported by Debian 'Etch' and is able to
2000install Debian into a virtual disk image. The following devices are
2001emulated:
2002
2003@itemize @minus
2004@item
2005A range of MIPS CPUs, default is the 24Kf
2006@item
2007PC style serial port
2008@item
2009PC style IDE disk
2010@item
2011NE2000 network card
2012@end itemize
2013
2014The Malta emulation supports the following devices:
2015
2016@itemize @minus
2017@item
2018Core board with MIPS 24Kf CPU and Galileo system controller
2019@item
2020PIIX4 PCI/USB/SMbus controller
2021@item
2022The Multi-I/O chip's serial device
2023@item
2024PCI network cards (PCnet32 and others)
2025@item
2026Malta FPGA serial device
2027@item
2028Cirrus (default) or any other PCI VGA graphics card
2029@end itemize
2030
2031The ACER Pica emulation supports:
2032
2033@itemize @minus
2034@item
2035MIPS R4000 CPU
2036@item
2037PC-style IRQ and DMA controllers
2038@item
2039PC Keyboard
2040@item
2041IDE controller
2042@end itemize
2043
2044The mipssim pseudo board emulation provides an environment similar
2045to what the proprietary MIPS emulator uses for running Linux.
2046It supports:
2047
2048@itemize @minus
2049@item
2050A range of MIPS CPUs, default is the 24Kf
2051@item
2052PC style serial port
2053@item
2054MIPSnet network emulation
2055@end itemize
2056
2057The MIPS Magnum R4000 emulation supports:
2058
2059@itemize @minus
2060@item
2061MIPS R4000 CPU
2062@item
2063PC-style IRQ controller
2064@item
2065PC Keyboard
2066@item
2067SCSI controller
2068@item
2069G364 framebuffer
2070@end itemize
2071
2072
2073@node ARM System emulator
2074@section ARM System emulator
2075@cindex system emulation (ARM)
2076
2077Use the executable @file{qemu-system-arm} to simulate a ARM
2078machine. The ARM Integrator/CP board is emulated with the following
2079devices:
2080
2081@itemize @minus
2082@item
2083ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU
2084@item
2085Two PL011 UARTs
2086@item
2087SMC 91c111 Ethernet adapter
2088@item
2089PL110 LCD controller
2090@item
2091PL050 KMI with PS/2 keyboard and mouse.
2092@item
2093PL181 MultiMedia Card Interface with SD card.
2094@end itemize
2095
2096The ARM Versatile baseboard is emulated with the following devices:
2097
2098@itemize @minus
2099@item
2100ARM926E, ARM1136 or Cortex-A8 CPU
2101@item
2102PL190 Vectored Interrupt Controller
2103@item
2104Four PL011 UARTs
2105@item
2106SMC 91c111 Ethernet adapter
2107@item
2108PL110 LCD controller
2109@item
2110PL050 KMI with PS/2 keyboard and mouse.
2111@item
2112PCI host bridge.  Note the emulated PCI bridge only provides access to
2113PCI memory space.  It does not provide access to PCI IO space.
2114This means some devices (eg. ne2k_pci NIC) are not usable, and others
2115(eg. rtl8139 NIC) are only usable when the guest drivers use the memory
2116mapped control registers.
2117@item
2118PCI OHCI USB controller.
2119@item
2120LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
2121@item
2122PL181 MultiMedia Card Interface with SD card.
2123@end itemize
2124
2125Several variants of the ARM RealView baseboard are emulated,
2126including the EB, PB-A8 and PBX-A9.  Due to interactions with the
2127bootloader, only certain Linux kernel configurations work out
2128of the box on these boards.
2129
2130Kernels for the PB-A8 board should have CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2131enabled in the kernel, and expect 512M RAM.  Kernels for The PBX-A9 board
2132should have CONFIG_SPARSEMEM enabled, CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2133disabled and expect 1024M RAM.
2134
2135The following devices are emulated:
2136
2137@itemize @minus
2138@item
2139ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU
2140@item
2141ARM AMBA Generic/Distributed Interrupt Controller
2142@item
2143Four PL011 UARTs
2144@item
2145SMC 91c111 or SMSC LAN9118 Ethernet adapter
2146@item
2147PL110 LCD controller
2148@item
2149PL050 KMI with PS/2 keyboard and mouse
2150@item
2151PCI host bridge
2152@item
2153PCI OHCI USB controller
2154@item
2155LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
2156@item
2157PL181 MultiMedia Card Interface with SD card.
2158@end itemize
2159
2160The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
2161and "Terrier") emulation includes the following peripherals:
2162
2163@itemize @minus
2164@item
2165Intel PXA270 System-on-chip (ARM V5TE core)
2166@item
2167NAND Flash memory
2168@item
2169IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
2170@item
2171On-chip OHCI USB controller
2172@item
2173On-chip LCD controller
2174@item
2175On-chip Real Time Clock
2176@item
2177TI ADS7846 touchscreen controller on SSP bus
2178@item
2179Maxim MAX1111 analog-digital converter on I@math{^2}C bus
2180@item
2181GPIO-connected keyboard controller and LEDs
2182@item
2183Secure Digital card connected to PXA MMC/SD host
2184@item
2185Three on-chip UARTs
2186@item
2187WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
2188@end itemize
2189
2190The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the
2191following elements:
2192
2193@itemize @minus
2194@item
2195Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2196@item
2197ROM and RAM memories (ROM firmware image can be loaded with -option-rom)
2198@item
2199On-chip LCD controller
2200@item
2201On-chip Real Time Clock
2202@item
2203TI TSC2102i touchscreen controller / analog-digital converter / Audio
2204CODEC, connected through MicroWire and I@math{^2}S busses
2205@item
2206GPIO-connected matrix keypad
2207@item
2208Secure Digital card connected to OMAP MMC/SD host
2209@item
2210Three on-chip UARTs
2211@end itemize
2212
2213Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48)
2214emulation supports the following elements:
2215
2216@itemize @minus
2217@item
2218Texas Instruments OMAP2420 System-on-chip (ARM 1136 core)
2219@item
2220RAM and non-volatile OneNAND Flash memories
2221@item
2222Display connected to EPSON remote framebuffer chip and OMAP on-chip
2223display controller and a LS041y3 MIPI DBI-C controller
2224@item
2225TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers
2226driven through SPI bus
2227@item
2228National Semiconductor LM8323-controlled qwerty keyboard driven
2229through I@math{^2}C bus
2230@item
2231Secure Digital card connected to OMAP MMC/SD host
2232@item
2233Three OMAP on-chip UARTs and on-chip STI debugging console
2234@item
2235A Bluetooth(R) transceiver and HCI connected to an UART
2236@item
2237Mentor Graphics "Inventra" dual-role USB controller embedded in a TI
2238TUSB6010 chip - only USB host mode is supported
2239@item
2240TI TMP105 temperature sensor driven through I@math{^2}C bus
2241@item
2242TI TWL92230C power management companion with an RTC on I@math{^2}C bus
2243@item
2244Nokia RETU and TAHVO multi-purpose chips with an RTC, connected
2245through CBUS
2246@end itemize
2247
2248The Luminary Micro Stellaris LM3S811EVB emulation includes the following
2249devices:
2250
2251@itemize @minus
2252@item
2253Cortex-M3 CPU core.
2254@item
225564k Flash and 8k SRAM.
2256@item
2257Timers, UARTs, ADC and I@math{^2}C interface.
2258@item
2259OSRAM Pictiva 96x16 OLED with SSD0303 controller on I@math{^2}C bus.
2260@end itemize
2261
2262The Luminary Micro Stellaris LM3S6965EVB emulation includes the following
2263devices:
2264
2265@itemize @minus
2266@item
2267Cortex-M3 CPU core.
2268@item
2269256k Flash and 64k SRAM.
2270@item
2271Timers, UARTs, ADC, I@math{^2}C and SSI interfaces.
2272@item
2273OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI.
2274@end itemize
2275
2276The Freecom MusicPal internet radio emulation includes the following
2277elements:
2278
2279@itemize @minus
2280@item
2281Marvell MV88W8618 ARM core.
2282@item
228332 MB RAM, 256 KB SRAM, 8 MB flash.
2284@item
2285Up to 2 16550 UARTs
2286@item
2287MV88W8xx8 Ethernet controller
2288@item
2289MV88W8618 audio controller, WM8750 CODEC and mixer
2290@item
229112864 display with brightness control
2292@item
22932 buttons, 2 navigation wheels with button function
2294@end itemize
2295
2296The Siemens SX1 models v1 and v2 (default) basic emulation.
2297The emulation includes the following elements:
2298
2299@itemize @minus
2300@item
2301Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2302@item
2303ROM and RAM memories (ROM firmware image can be loaded with -pflash)
2304V1
23051 Flash of 16MB and 1 Flash of 8MB
2306V2
23071 Flash of 32MB
2308@item
2309On-chip LCD controller
2310@item
2311On-chip Real Time Clock
2312@item
2313Secure Digital card connected to OMAP MMC/SD host
2314@item
2315Three on-chip UARTs
2316@end itemize
2317
2318A Linux 2.6 test image is available on the QEMU web site. More
2319information is available in the QEMU mailing-list archive.
2320
2321@c man begin OPTIONS
2322
2323The following options are specific to the ARM emulation:
2324
2325@table @option
2326
2327@item -semihosting
2328Enable semihosting syscall emulation.
2329
2330On ARM this implements the "Angel" interface.
2331
2332Note that this allows guest direct access to the host filesystem,
2333so should only be used with trusted guest OS.
2334
2335@end table
2336
2337@c man end
2338
2339@node ColdFire System emulator
2340@section ColdFire System emulator
2341@cindex system emulation (ColdFire)
2342@cindex system emulation (M68K)
2343
2344Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2345The emulator is able to boot a uClinux kernel.
2346
2347The M5208EVB emulation includes the following devices:
2348
2349@itemize @minus
2350@item
2351MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2352@item
2353Three Two on-chip UARTs.
2354@item
2355Fast Ethernet Controller (FEC)
2356@end itemize
2357
2358The AN5206 emulation includes the following devices:
2359
2360@itemize @minus
2361@item
2362MCF5206 ColdFire V2 Microprocessor.
2363@item
2364Two on-chip UARTs.
2365@end itemize
2366
2367@c man begin OPTIONS
2368
2369The following options are specific to the ColdFire emulation:
2370
2371@table @option
2372
2373@item -semihosting
2374Enable semihosting syscall emulation.
2375
2376On M68K this implements the "ColdFire GDB" interface used by libgloss.
2377
2378Note that this allows guest direct access to the host filesystem,
2379so should only be used with trusted guest OS.
2380
2381@end table
2382
2383@c man end
2384
2385@node Cris System emulator
2386@section Cris System emulator
2387@cindex system emulation (Cris)
2388
2389TODO
2390
2391@node Microblaze System emulator
2392@section Microblaze System emulator
2393@cindex system emulation (Microblaze)
2394
2395TODO
2396
2397@node SH4 System emulator
2398@section SH4 System emulator
2399@cindex system emulation (SH4)
2400
2401TODO
2402
2403@node Xtensa System emulator
2404@section Xtensa System emulator
2405@cindex system emulation (Xtensa)
2406
2407Two executables cover simulation of both Xtensa endian options,
2408@file{qemu-system-xtensa} and @file{qemu-system-xtensaeb}.
2409Two different machine types are emulated:
2410
2411@itemize @minus
2412@item
2413Xtensa emulator pseudo board "sim"
2414@item
2415Avnet LX60/LX110/LX200 board
2416@end itemize
2417
2418The sim pseudo board emulation provides an environment similar
2419to one provided by the proprietary Tensilica ISS.
2420It supports:
2421
2422@itemize @minus
2423@item
2424A range of Xtensa CPUs, default is the DC232B
2425@item
2426Console and filesystem access via semihosting calls
2427@end itemize
2428
2429The Avnet LX60/LX110/LX200 emulation supports:
2430
2431@itemize @minus
2432@item
2433A range of Xtensa CPUs, default is the DC232B
2434@item
243516550 UART
2436@item
2437OpenCores 10/100 Mbps Ethernet MAC
2438@end itemize
2439
2440@c man begin OPTIONS
2441
2442The following options are specific to the Xtensa emulation:
2443
2444@table @option
2445
2446@item -semihosting
2447Enable semihosting syscall emulation.
2448
2449Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select.
2450Tensilica baremetal libc for ISS and linux platform "sim" use this interface.
2451
2452Note that this allows guest direct access to the host filesystem,
2453so should only be used with trusted guest OS.
2454
2455@end table
2456
2457@c man end
2458
2459@node QEMU Guest Agent
2460@chapter QEMU Guest Agent invocation
2461
2462@include qemu-ga.texi
2463
2464@node QEMU User space emulator
2465@chapter QEMU User space emulator
2466
2467@menu
2468* Supported Operating Systems ::
2469* Features::
2470* Linux User space emulator::
2471* BSD User space emulator ::
2472@end menu
2473
2474@node Supported Operating Systems
2475@section Supported Operating Systems
2476
2477The following OS are supported in user space emulation:
2478
2479@itemize @minus
2480@item
2481Linux (referred as qemu-linux-user)
2482@item
2483BSD (referred as qemu-bsd-user)
2484@end itemize
2485
2486@node Features
2487@section Features
2488
2489QEMU user space emulation has the following notable features:
2490
2491@table @strong
2492@item System call translation:
2493QEMU includes a generic system call translator.  This means that
2494the parameters of the system calls can be converted to fix
2495endianness and 32/64-bit mismatches between hosts and targets.
2496IOCTLs can be converted too.
2497
2498@item POSIX signal handling:
2499QEMU can redirect to the running program all signals coming from
2500the host (such as @code{SIGALRM}), as well as synthesize signals from
2501virtual CPU exceptions (for example @code{SIGFPE} when the program
2502executes a division by zero).
2503
2504QEMU relies on the host kernel to emulate most signal system
2505calls, for example to emulate the signal mask.  On Linux, QEMU
2506supports both normal and real-time signals.
2507
2508@item Threading:
2509On Linux, QEMU can emulate the @code{clone} syscall and create a real
2510host thread (with a separate virtual CPU) for each emulated thread.
2511Note that not all targets currently emulate atomic operations correctly.
2512x86 and ARM use a global lock in order to preserve their semantics.
2513@end table
2514
2515QEMU was conceived so that ultimately it can emulate itself. Although
2516it is not very useful, it is an important test to show the power of the
2517emulator.
2518
2519@node Linux User space emulator
2520@section Linux User space emulator
2521
2522@menu
2523* Quick Start::
2524* Wine launch::
2525* Command line options::
2526* Other binaries::
2527@end menu
2528
2529@node Quick Start
2530@subsection Quick Start
2531
2532In order to launch a Linux process, QEMU needs the process executable
2533itself and all the target (x86) dynamic libraries used by it.
2534
2535@itemize
2536
2537@item On x86, you can just try to launch any process by using the native
2538libraries:
2539
2540@example
2541qemu-i386 -L / /bin/ls
2542@end example
2543
2544@code{-L /} tells that the x86 dynamic linker must be searched with a
2545@file{/} prefix.
2546
2547@item Since QEMU is also a linux process, you can launch QEMU with
2548QEMU (NOTE: you can only do that if you compiled QEMU from the sources):
2549
2550@example
2551qemu-i386 -L / qemu-i386 -L / /bin/ls
2552@end example
2553
2554@item On non x86 CPUs, you need first to download at least an x86 glibc
2555(@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2556@code{LD_LIBRARY_PATH} is not set:
2557
2558@example
2559unset LD_LIBRARY_PATH
2560@end example
2561
2562Then you can launch the precompiled @file{ls} x86 executable:
2563
2564@example
2565qemu-i386 tests/i386/ls
2566@end example
2567You can look at @file{scripts/qemu-binfmt-conf.sh} so that
2568QEMU is automatically launched by the Linux kernel when you try to
2569launch x86 executables. It requires the @code{binfmt_misc} module in the
2570Linux kernel.
2571
2572@item The x86 version of QEMU is also included. You can try weird things such as:
2573@example
2574qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2575          /usr/local/qemu-i386/bin/ls-i386
2576@end example
2577
2578@end itemize
2579
2580@node Wine launch
2581@subsection Wine launch
2582
2583@itemize
2584
2585@item Ensure that you have a working QEMU with the x86 glibc
2586distribution (see previous section). In order to verify it, you must be
2587able to do:
2588
2589@example
2590qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2591@end example
2592
2593@item Download the binary x86 Wine install
2594(@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2595
2596@item Configure Wine on your account. Look at the provided script
2597@file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2598@code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2599
2600@item Then you can try the example @file{putty.exe}:
2601
2602@example
2603qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2604          /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2605@end example
2606
2607@end itemize
2608
2609@node Command line options
2610@subsection Command line options
2611
2612@example
2613@command{qemu-i386} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-cpu} @var{model}] [@option{-g} @var{port}] [@option{-B} @var{offset}] [@option{-R} @var{size}] @var{program} [@var{arguments}...]
2614@end example
2615
2616@table @option
2617@item -h
2618Print the help
2619@item -L path
2620Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2621@item -s size
2622Set the x86 stack size in bytes (default=524288)
2623@item -cpu model
2624Select CPU model (-cpu help for list and additional feature selection)
2625@item -E @var{var}=@var{value}
2626Set environment @var{var} to @var{value}.
2627@item -U @var{var}
2628Remove @var{var} from the environment.
2629@item -B offset
2630Offset guest address by the specified number of bytes.  This is useful when
2631the address region required by guest applications is reserved on the host.
2632This option is currently only supported on some hosts.
2633@item -R size
2634Pre-allocate a guest virtual address space of the given size (in bytes).
2635"G", "M", and "k" suffixes may be used when specifying the size.
2636@end table
2637
2638Debug options:
2639
2640@table @option
2641@item -d item1,...
2642Activate logging of the specified items (use '-d help' for a list of log items)
2643@item -p pagesize
2644Act as if the host page size was 'pagesize' bytes
2645@item -g port
2646Wait gdb connection to port
2647@item -singlestep
2648Run the emulation in single step mode.
2649@end table
2650
2651Environment variables:
2652
2653@table @env
2654@item QEMU_STRACE
2655Print system calls and arguments similar to the 'strace' program
2656(NOTE: the actual 'strace' program will not work because the user
2657space emulator hasn't implemented ptrace).  At the moment this is
2658incomplete.  All system calls that don't have a specific argument
2659format are printed with information for six arguments.  Many
2660flag-style arguments don't have decoders and will show up as numbers.
2661@end table
2662
2663@node Other binaries
2664@subsection Other binaries
2665
2666@cindex user mode (Alpha)
2667@command{qemu-alpha} TODO.
2668
2669@cindex user mode (ARM)
2670@command{qemu-armeb} TODO.
2671
2672@cindex user mode (ARM)
2673@command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2674binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2675configurations), and arm-uclinux bFLT format binaries.
2676
2677@cindex user mode (ColdFire)
2678@cindex user mode (M68K)
2679@command{qemu-m68k} is capable of running semihosted binaries using the BDM
2680(m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2681coldfire uClinux bFLT format binaries.
2682
2683The binary format is detected automatically.
2684
2685@cindex user mode (Cris)
2686@command{qemu-cris} TODO.
2687
2688@cindex user mode (i386)
2689@command{qemu-i386} TODO.
2690@command{qemu-x86_64} TODO.
2691
2692@cindex user mode (Microblaze)
2693@command{qemu-microblaze} TODO.
2694
2695@cindex user mode (MIPS)
2696@command{qemu-mips} TODO.
2697@command{qemu-mipsel} TODO.
2698
2699@cindex user mode (NiosII)
2700@command{qemu-nios2} TODO.
2701
2702@cindex user mode (PowerPC)
2703@command{qemu-ppc64abi32} TODO.
2704@command{qemu-ppc64} TODO.
2705@command{qemu-ppc} TODO.
2706
2707@cindex user mode (SH4)
2708@command{qemu-sh4eb} TODO.
2709@command{qemu-sh4} TODO.
2710
2711@cindex user mode (SPARC)
2712@command{qemu-sparc} can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).
2713
2714@command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2715(Sparc64 CPU, 32 bit ABI).
2716
2717@command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2718SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2719
2720@node BSD User space emulator
2721@section BSD User space emulator
2722
2723@menu
2724* BSD Status::
2725* BSD Quick Start::
2726* BSD Command line options::
2727@end menu
2728
2729@node BSD Status
2730@subsection BSD Status
2731
2732@itemize @minus
2733@item
2734target Sparc64 on Sparc64: Some trivial programs work.
2735@end itemize
2736
2737@node BSD Quick Start
2738@subsection Quick Start
2739
2740In order to launch a BSD process, QEMU needs the process executable
2741itself and all the target dynamic libraries used by it.
2742
2743@itemize
2744
2745@item On Sparc64, you can just try to launch any process by using the native
2746libraries:
2747
2748@example
2749qemu-sparc64 /bin/ls
2750@end example
2751
2752@end itemize
2753
2754@node BSD Command line options
2755@subsection Command line options
2756
2757@example
2758@command{qemu-sparc64} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-bsd} @var{type}] @var{program} [@var{arguments}...]
2759@end example
2760
2761@table @option
2762@item -h
2763Print the help
2764@item -L path
2765Set the library root path (default=/)
2766@item -s size
2767Set the stack size in bytes (default=524288)
2768@item -ignore-environment
2769Start with an empty environment. Without this option,
2770the initial environment is a copy of the caller's environment.
2771@item -E @var{var}=@var{value}
2772Set environment @var{var} to @var{value}.
2773@item -U @var{var}
2774Remove @var{var} from the environment.
2775@item -bsd type
2776Set the type of the emulated BSD Operating system. Valid values are
2777FreeBSD, NetBSD and OpenBSD (default).
2778@end table
2779
2780Debug options:
2781
2782@table @option
2783@item -d item1,...
2784Activate logging of the specified items (use '-d help' for a list of log items)
2785@item -p pagesize
2786Act as if the host page size was 'pagesize' bytes
2787@item -singlestep
2788Run the emulation in single step mode.
2789@end table
2790
2791
2792@include qemu-tech.texi
2793
2794@include qemu-deprecated.texi
2795
2796@node Supported build platforms
2797@appendix Supported build platforms
2798
2799QEMU aims to support building and executing on multiple host OS platforms.
2800This appendix outlines which platforms are the major build targets. These
2801platforms are used as the basis for deciding upon the minimum required
2802versions of 3rd party software QEMU depends on. The supported platforms
2803are the targets for automated testing performed by the project when patches
2804are submitted for review, and tested before and after merge.
2805
2806If a platform is not listed here, it does not imply that QEMU won't work.
2807If an unlisted platform has comparable software versions to a listed platform,
2808there is every expectation that it will work. Bug reports are welcome for
2809problems encountered on unlisted platforms unless they are clearly older
2810vintage than what is described here.
2811
2812Note that when considering software versions shipped in distros as support
2813targets, QEMU considers only the version number, and assumes the features in
2814that distro match the upstream release with the same version. In other words,
2815if a distro backports extra features to the software in their distro, QEMU
2816upstream code will not add explicit support for those backports, unless the
2817feature is auto-detectable in a manner that works for the upstream releases
2818too.
2819
2820The Repology site @url{https://repology.org} is a useful resource to identify
2821currently shipped versions of software in various operating systems, though
2822it does not cover all distros listed below.
2823
2824@section Linux OS
2825
2826For distributions with frequent, short-lifetime releases, the project will
2827aim to support all versions that are not end of life by their respective
2828vendors. For the purposes of identifying supported software versions, the
2829project will look at Fedora, Ubuntu, and openSUSE distros. Other short-
2830lifetime distros will be assumed to ship similar software versions.
2831
2832For distributions with long-lifetime releases, the project will aim to support
2833the most recent major version at all times. Support for the previous major
2834version will be dropped 2 years after the new major version is released. For
2835the purposes of identifying supported software versions, the project will look
2836at RHEL, Debian, Ubuntu LTS, and SLES distros. Other long-lifetime distros will
2837be assumed to ship similar software versions.
2838
2839@section Windows
2840
2841The project supports building with current versions of the MinGW toolchain,
2842hosted on Linux.
2843
2844@section macOS
2845
2846The project supports building with the two most recent versions of macOS, with
2847the current homebrew package set available.
2848
2849@section FreeBSD
2850
2851The project aims to support the all the versions which are not end of life.
2852
2853@section NetBSD
2854
2855The project aims to support the most recent major version at all times. Support
2856for the previous major version will be dropped 2 years after the new major
2857version is released.
2858
2859@section OpenBSD
2860
2861The project aims to support the all the versions which are not end of life.
2862
2863@node License
2864@appendix License
2865
2866QEMU is a trademark of Fabrice Bellard.
2867
2868QEMU is released under the
2869@url{https://www.gnu.org/licenses/gpl-2.0.txt,GNU General Public License},
2870version 2. Parts of QEMU have specific licenses, see file
2871@url{https://git.qemu.org/?p=qemu.git;a=blob_plain;f=LICENSE,LICENSE}.
2872
2873@node Index
2874@appendix Index
2875@menu
2876* Concept Index::
2877* Function Index::
2878* Keystroke Index::
2879* Program Index::
2880* Data Type Index::
2881* Variable Index::
2882@end menu
2883
2884@node Concept Index
2885@section Concept Index
2886This is the main index. Should we combine all keywords in one index? TODO
2887@printindex cp
2888
2889@node Function Index
2890@section Function Index
2891This index could be used for command line options and monitor functions.
2892@printindex fn
2893
2894@node Keystroke Index
2895@section Keystroke Index
2896
2897This is a list of all keystrokes which have a special function
2898in system emulation.
2899
2900@printindex ky
2901
2902@node Program Index
2903@section Program Index
2904@printindex pg
2905
2906@node Data Type Index
2907@section Data Type Index
2908
2909This index could be used for qdev device names and options.
2910
2911@printindex tp
2912
2913@node Variable Index
2914@section Variable Index
2915@printindex vr
2916
2917@bye
2918