1 \input texinfo @c -*- texinfo -*-
3 @setfilename qemu-doc.info
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8 @settitle QEMU Emulator User Documentation
15 * QEMU: (qemu-doc). The QEMU Emulator User Documentation.
22 @center @titlefont{QEMU Emulator}
24 @center @titlefont{User Documentation}
36 * QEMU PC System emulator::
37 * QEMU System emulator for non PC targets::
38 * QEMU User space emulator::
39 * compilation:: Compilation from the sources
51 * intro_features:: Features
57 QEMU is a FAST! processor emulator using dynamic translation to
58 achieve good emulation speed.
60 @cindex operating modes
61 QEMU has two operating modes:
64 @cindex system emulation
65 @item Full system emulation. In this mode, QEMU emulates a full system (for
66 example a PC), including one or several processors and various
67 peripherals. It can be used to launch different Operating Systems
68 without rebooting the PC or to debug system code.
70 @cindex user mode emulation
71 @item User mode emulation. In this mode, QEMU can launch
72 processes compiled for one CPU on another CPU. It can be used to
73 launch the Wine Windows API emulator (@url{http://www.winehq.org}) or
74 to ease cross-compilation and cross-debugging.
78 QEMU has the following features:
81 @item QEMU can run without a host kernel driver and yet gives acceptable
82 performance. It uses dynamic translation to native code for reasonable speed,
83 with support for self-modifying code and precise exceptions.
85 @item It is portable to several operating systems (GNU/Linux, *BSD, Mac OS X,
86 Windows) and architectures.
88 @item It performs accurate software emulation of the FPU.
91 QEMU user mode emulation has the following features:
93 @item Generic Linux system call converter, including most ioctls.
95 @item clone() emulation using native CPU clone() to use Linux scheduler for threads.
97 @item Accurate signal handling by remapping host signals to target signals.
100 QEMU full system emulation has the following features:
103 QEMU uses a full software MMU for maximum portability.
106 QEMU can optionally use an in-kernel accelerator, like kvm. The accelerators
107 execute most of the guest code natively, while
108 continuing to emulate the rest of the machine.
111 Various hardware devices can be emulated and in some cases, host
112 devices (e.g. serial and parallel ports, USB, drives) can be used
113 transparently by the guest Operating System. Host device passthrough
114 can be used for talking to external physical peripherals (e.g. a
115 webcam, modem or tape drive).
118 Symmetric multiprocessing (SMP) support. Currently, an in-kernel
119 accelerator is required to use more than one host CPU for emulation.
125 @chapter Installation
127 If you want to compile QEMU yourself, see @ref{compilation}.
130 * install_linux:: Linux
131 * install_windows:: Windows
132 * install_mac:: Macintosh
137 @cindex installation (Linux)
139 If a precompiled package is available for your distribution - you just
140 have to install it. Otherwise, see @ref{compilation}.
142 @node install_windows
144 @cindex installation (Windows)
146 Download the experimental binary installer at
147 @url{http://www.free.oszoo.org/@/download.html}.
148 TODO (no longer available)
153 Download the experimental binary installer at
154 @url{http://www.free.oszoo.org/@/download.html}.
155 TODO (no longer available)
157 @node QEMU PC System emulator
158 @chapter QEMU PC System emulator
159 @cindex system emulation (PC)
162 * pcsys_introduction:: Introduction
163 * pcsys_quickstart:: Quick Start
164 * sec_invocation:: Invocation
165 * pcsys_keys:: Keys in the graphical frontends
166 * mux_keys:: Keys in the character backend multiplexer
167 * pcsys_monitor:: QEMU Monitor
168 * disk_images:: Disk Images
169 * pcsys_network:: Network emulation
170 * pcsys_other_devs:: Other Devices
171 * direct_linux_boot:: Direct Linux Boot
172 * pcsys_usb:: USB emulation
173 * vnc_security:: VNC security
174 * gdb_usage:: GDB usage
175 * pcsys_os_specific:: Target OS specific information
178 @node pcsys_introduction
179 @section Introduction
181 @c man begin DESCRIPTION
183 The QEMU PC System emulator simulates the
184 following peripherals:
188 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
190 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
191 extensions (hardware level, including all non standard modes).
193 PS/2 mouse and keyboard
195 2 PCI IDE interfaces with hard disk and CD-ROM support
199 PCI and ISA network adapters
203 IPMI BMC, either and internal or external one
205 Creative SoundBlaster 16 sound card
207 ENSONIQ AudioPCI ES1370 sound card
209 Intel 82801AA AC97 Audio compatible sound card
211 Intel HD Audio Controller and HDA codec
213 Adlib (OPL2) - Yamaha YM3812 compatible chip
215 Gravis Ultrasound GF1 sound card
217 CS4231A compatible sound card
219 PCI UHCI USB controller and a virtual USB hub.
222 SMP is supported with up to 255 CPUs.
224 QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs LGPL
227 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
229 QEMU uses GUS emulation (GUSEMU32 @url{http://www.deinmeister.de/gusemu/})
230 by Tibor "TS" Schütz.
232 Note that, by default, GUS shares IRQ(7) with parallel ports and so
233 QEMU must be told to not have parallel ports to have working GUS.
236 qemu-system-i386 dos.img -soundhw gus -parallel none
241 qemu-system-i386 dos.img -device gus,irq=5
244 Or some other unclaimed IRQ.
246 CS4231A is the chip used in Windows Sound System and GUSMAX products
250 @node pcsys_quickstart
254 Download and uncompress the linux image (@file{linux.img}) and type:
257 qemu-system-i386 linux.img
260 Linux should boot and give you a prompt.
266 @c man begin SYNOPSIS
267 @command{qemu-system-i386} [@var{options}] [@var{disk_image}]
272 @var{disk_image} is a raw hard disk image for IDE hard disk 0. Some
273 targets do not need a disk image.
275 @include qemu-options.texi
280 @section Keys in the graphical frontends
284 During the graphical emulation, you can use special key combinations to change
285 modes. The default key mappings are shown below, but if you use @code{-alt-grab}
286 then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use
287 @code{-ctrl-grab} then the modifier is the right Ctrl key (instead of Ctrl-Alt):
304 Restore the screen's un-scaled dimensions
308 Switch to virtual console 'n'. Standard console mappings are:
311 Target system display
320 Toggle mouse and keyboard grab.
326 @kindex Ctrl-PageDown
327 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
328 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
333 @section Keys in the character backend multiplexer
337 During emulation, if you are using a character backend multiplexer
338 (which is the default if you are using @option{-nographic}) then
339 several commands are available via an escape sequence. These
340 key sequences all start with an escape character, which is @key{Ctrl-a}
341 by default, but can be changed with @option{-echr}. The list below assumes
342 you're using the default.
353 Save disk data back to file (if -snapshot)
356 Toggle console timestamps
359 Send break (magic sysrq in Linux)
362 Rotate between the frontends connected to the multiplexer (usually
363 this switches between the monitor and the console)
365 @kindex Ctrl-a Ctrl-a
366 Send the escape character to the frontend
373 The HTML documentation of QEMU for more precise information and Linux
374 user mode emulator invocation.
384 @section QEMU Monitor
387 The QEMU monitor is used to give complex commands to the QEMU
388 emulator. You can use it to:
393 Remove or insert removable media images
394 (such as CD-ROM or floppies).
397 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
400 @item Inspect the VM state without an external debugger.
406 The following commands are available:
408 @include qemu-monitor.texi
410 @include qemu-monitor-info.texi
412 @subsection Integer expressions
414 The monitor understands integers expressions for every integer
415 argument. You can use register names to get the value of specifics
416 CPU registers by prefixing them with @emph{$}.
421 Since version 0.6.1, QEMU supports many disk image formats, including
422 growable disk images (their size increase as non empty sectors are
423 written), compressed and encrypted disk images. Version 0.8.3 added
424 the new qcow2 disk image format which is essential to support VM
428 * disk_images_quickstart:: Quick start for disk image creation
429 * disk_images_snapshot_mode:: Snapshot mode
430 * vm_snapshots:: VM snapshots
431 * qemu_img_invocation:: qemu-img Invocation
432 * qemu_nbd_invocation:: qemu-nbd Invocation
433 * qemu_ga_invocation:: qemu-ga Invocation
434 * disk_images_formats:: Disk image file formats
435 * host_drives:: Using host drives
436 * disk_images_fat_images:: Virtual FAT disk images
437 * disk_images_nbd:: NBD access
438 * disk_images_sheepdog:: Sheepdog disk images
439 * disk_images_iscsi:: iSCSI LUNs
440 * disk_images_gluster:: GlusterFS disk images
441 * disk_images_ssh:: Secure Shell (ssh) disk images
444 @node disk_images_quickstart
445 @subsection Quick start for disk image creation
447 You can create a disk image with the command:
449 qemu-img create myimage.img mysize
451 where @var{myimage.img} is the disk image filename and @var{mysize} is its
452 size in kilobytes. You can add an @code{M} suffix to give the size in
453 megabytes and a @code{G} suffix for gigabytes.
455 See @ref{qemu_img_invocation} for more information.
457 @node disk_images_snapshot_mode
458 @subsection Snapshot mode
460 If you use the option @option{-snapshot}, all disk images are
461 considered as read only. When sectors in written, they are written in
462 a temporary file created in @file{/tmp}. You can however force the
463 write back to the raw disk images by using the @code{commit} monitor
464 command (or @key{C-a s} in the serial console).
467 @subsection VM snapshots
469 VM snapshots are snapshots of the complete virtual machine including
470 CPU state, RAM, device state and the content of all the writable
471 disks. In order to use VM snapshots, you must have at least one non
472 removable and writable block device using the @code{qcow2} disk image
473 format. Normally this device is the first virtual hard drive.
475 Use the monitor command @code{savevm} to create a new VM snapshot or
476 replace an existing one. A human readable name can be assigned to each
477 snapshot in addition to its numerical ID.
479 Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
480 a VM snapshot. @code{info snapshots} lists the available snapshots
481 with their associated information:
484 (qemu) info snapshots
485 Snapshot devices: hda
486 Snapshot list (from hda):
487 ID TAG VM SIZE DATE VM CLOCK
488 1 start 41M 2006-08-06 12:38:02 00:00:14.954
489 2 40M 2006-08-06 12:43:29 00:00:18.633
490 3 msys 40M 2006-08-06 12:44:04 00:00:23.514
493 A VM snapshot is made of a VM state info (its size is shown in
494 @code{info snapshots}) and a snapshot of every writable disk image.
495 The VM state info is stored in the first @code{qcow2} non removable
496 and writable block device. The disk image snapshots are stored in
497 every disk image. The size of a snapshot in a disk image is difficult
498 to evaluate and is not shown by @code{info snapshots} because the
499 associated disk sectors are shared among all the snapshots to save
500 disk space (otherwise each snapshot would need a full copy of all the
503 When using the (unrelated) @code{-snapshot} option
504 (@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
505 but they are deleted as soon as you exit QEMU.
507 VM snapshots currently have the following known limitations:
510 They cannot cope with removable devices if they are removed or
511 inserted after a snapshot is done.
513 A few device drivers still have incomplete snapshot support so their
514 state is not saved or restored properly (in particular USB).
517 @node qemu_img_invocation
518 @subsection @code{qemu-img} Invocation
520 @include qemu-img.texi
522 @node qemu_nbd_invocation
523 @subsection @code{qemu-nbd} Invocation
525 @include qemu-nbd.texi
527 @node qemu_ga_invocation
528 @subsection @code{qemu-ga} Invocation
530 @include qemu-ga.texi
532 @node disk_images_formats
533 @subsection Disk image file formats
535 QEMU supports many image file formats that can be used with VMs as well as with
536 any of the tools (like @code{qemu-img}). This includes the preferred formats
537 raw and qcow2 as well as formats that are supported for compatibility with
538 older QEMU versions or other hypervisors.
540 Depending on the image format, different options can be passed to
541 @code{qemu-img create} and @code{qemu-img convert} using the @code{-o} option.
542 This section describes each format and the options that are supported for it.
547 Raw disk image format. This format has the advantage of
548 being simple and easily exportable to all other emulators. If your
549 file system supports @emph{holes} (for example in ext2 or ext3 on
550 Linux or NTFS on Windows), then only the written sectors will reserve
551 space. Use @code{qemu-img info} to know the real size used by the
552 image or @code{ls -ls} on Unix/Linux.
557 Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}).
558 @code{falloc} mode preallocates space for image by calling posix_fallocate().
559 @code{full} mode preallocates space for image by writing zeros to underlying
564 QEMU image format, the most versatile format. Use it to have smaller
565 images (useful if your filesystem does not supports holes, for example
566 on Windows), zlib based compression and support of multiple VM
572 Determines the qcow2 version to use. @code{compat=0.10} uses the
573 traditional image format that can be read by any QEMU since 0.10.
574 @code{compat=1.1} enables image format extensions that only QEMU 1.1 and
575 newer understand (this is the default). Amongst others, this includes
576 zero clusters, which allow efficient copy-on-read for sparse images.
579 File name of a base image (see @option{create} subcommand)
581 Image format of the base image
583 If this option is set to @code{on}, the image is encrypted with 128-bit AES-CBC.
585 The use of encryption in qcow and qcow2 images is considered to be flawed by
586 modern cryptography standards, suffering from a number of design problems:
589 @item The AES-CBC cipher is used with predictable initialization vectors based
590 on the sector number. This makes it vulnerable to chosen plaintext attacks
591 which can reveal the existence of encrypted data.
592 @item The user passphrase is directly used as the encryption key. A poorly
593 chosen or short passphrase will compromise the security of the encryption.
594 @item In the event of the passphrase being compromised there is no way to
595 change the passphrase to protect data in any qcow images. The files must
596 be cloned, using a different encryption passphrase in the new file. The
597 original file must then be securely erased using a program like shred,
598 though even this is ineffective with many modern storage technologies.
601 Use of qcow / qcow2 encryption with QEMU is deprecated, and support for
602 it will go away in a future release. Users are recommended to use an
603 alternative encryption technology such as the Linux dm-crypt / LUKS
607 Changes the qcow2 cluster size (must be between 512 and 2M). Smaller cluster
608 sizes can improve the image file size whereas larger cluster sizes generally
609 provide better performance.
612 Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
613 @code{full}). An image with preallocated metadata is initially larger but can
614 improve performance when the image needs to grow. @code{falloc} and @code{full}
615 preallocations are like the same options of @code{raw} format, but sets up
619 If this option is set to @code{on}, reference count updates are postponed with
620 the goal of avoiding metadata I/O and improving performance. This is
621 particularly interesting with @option{cache=writethrough} which doesn't batch
622 metadata updates. The tradeoff is that after a host crash, the reference count
623 tables must be rebuilt, i.e. on the next open an (automatic) @code{qemu-img
624 check -r all} is required, which may take some time.
626 This option can only be enabled if @code{compat=1.1} is specified.
629 If this option is set to @code{on}, it will turn off COW of the file. It's only
630 valid on btrfs, no effect on other file systems.
632 Btrfs has low performance when hosting a VM image file, even more when the guest
633 on the VM also using btrfs as file system. Turning off COW is a way to mitigate
634 this bad performance. Generally there are two ways to turn off COW on btrfs:
635 a) Disable it by mounting with nodatacow, then all newly created files will be
636 NOCOW. b) For an empty file, add the NOCOW file attribute. That's what this option
639 Note: this option is only valid to new or empty files. If there is an existing
640 file which is COW and has data blocks already, it couldn't be changed to NOCOW
641 by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if
642 the NOCOW flag is set or not (Capital 'C' is NOCOW flag).
647 Old QEMU image format with support for backing files and compact image files
648 (when your filesystem or transport medium does not support holes).
650 When converting QED images to qcow2, you might want to consider using the
651 @code{lazy_refcounts=on} option to get a more QED-like behaviour.
656 File name of a base image (see @option{create} subcommand).
658 Image file format of backing file (optional). Useful if the format cannot be
659 autodetected because it has no header, like some vhd/vpc files.
661 Changes the cluster size (must be power-of-2 between 4K and 64K). Smaller
662 cluster sizes can improve the image file size whereas larger cluster sizes
663 generally provide better performance.
665 Changes the number of clusters per L1/L2 table (must be power-of-2 between 1
666 and 16). There is normally no need to change this value but this option can be
667 used for performance benchmarking.
671 Old QEMU image format with support for backing files, compact image files,
672 encryption and compression.
677 File name of a base image (see @option{create} subcommand)
679 If this option is set to @code{on}, the image is encrypted.
683 VirtualBox 1.1 compatible image format.
687 If this option is set to @code{on}, the image is created with metadata
692 VMware 3 and 4 compatible image format.
697 File name of a base image (see @option{create} subcommand).
699 Create a VMDK version 6 image (instead of version 4)
701 Specify vmdk virtual hardware version. Compat6 flag cannot be enabled
702 if hwversion is specified.
704 Specifies which VMDK subformat to use. Valid options are
705 @code{monolithicSparse} (default),
706 @code{monolithicFlat},
707 @code{twoGbMaxExtentSparse},
708 @code{twoGbMaxExtentFlat} and
709 @code{streamOptimized}.
713 VirtualPC compatible image format (VHD).
717 Specifies which VHD subformat to use. Valid options are
718 @code{dynamic} (default) and @code{fixed}.
722 Hyper-V compatible image format (VHDX).
726 Specifies which VHDX subformat to use. Valid options are
727 @code{dynamic} (default) and @code{fixed}.
728 @item block_state_zero
729 Force use of payload blocks of type 'ZERO'. Can be set to @code{on} (default)
730 or @code{off}. When set to @code{off}, new blocks will be created as
731 @code{PAYLOAD_BLOCK_NOT_PRESENT}, which means parsers are free to return
732 arbitrary data for those blocks. Do not set to @code{off} when using
733 @code{qemu-img convert} with @code{subformat=dynamic}.
735 Block size; min 1 MB, max 256 MB. 0 means auto-calculate based on image size.
741 @subsubsection Read-only formats
742 More disk image file formats are supported in a read-only mode.
745 Bochs images of @code{growing} type.
747 Linux Compressed Loop image, useful only to reuse directly compressed
748 CD-ROM images present for example in the Knoppix CD-ROMs.
752 Parallels disk image format.
757 @subsection Using host drives
759 In addition to disk image files, QEMU can directly access host
760 devices. We describe here the usage for QEMU version >= 0.8.3.
764 On Linux, you can directly use the host device filename instead of a
765 disk image filename provided you have enough privileges to access
766 it. For example, use @file{/dev/cdrom} to access to the CDROM.
770 You can specify a CDROM device even if no CDROM is loaded. QEMU has
771 specific code to detect CDROM insertion or removal. CDROM ejection by
772 the guest OS is supported. Currently only data CDs are supported.
774 You can specify a floppy device even if no floppy is loaded. Floppy
775 removal is currently not detected accurately (if you change floppy
776 without doing floppy access while the floppy is not loaded, the guest
777 OS will think that the same floppy is loaded).
778 Use of the host's floppy device is deprecated, and support for it will
779 be removed in a future release.
781 Hard disks can be used. Normally you must specify the whole disk
782 (@file{/dev/hdb} instead of @file{/dev/hdb1}) so that the guest OS can
783 see it as a partitioned disk. WARNING: unless you know what you do, it
784 is better to only make READ-ONLY accesses to the hard disk otherwise
785 you may corrupt your host data (use the @option{-snapshot} command
786 line option or modify the device permissions accordingly).
789 @subsubsection Windows
793 The preferred syntax is the drive letter (e.g. @file{d:}). The
794 alternate syntax @file{\\.\d:} is supported. @file{/dev/cdrom} is
795 supported as an alias to the first CDROM drive.
797 Currently there is no specific code to handle removable media, so it
798 is better to use the @code{change} or @code{eject} monitor commands to
799 change or eject media.
801 Hard disks can be used with the syntax: @file{\\.\PhysicalDrive@var{N}}
802 where @var{N} is the drive number (0 is the first hard disk).
804 WARNING: unless you know what you do, it is better to only make
805 READ-ONLY accesses to the hard disk otherwise you may corrupt your
806 host data (use the @option{-snapshot} command line so that the
807 modifications are written in a temporary file).
811 @subsubsection Mac OS X
813 @file{/dev/cdrom} is an alias to the first CDROM.
815 Currently there is no specific code to handle removable media, so it
816 is better to use the @code{change} or @code{eject} monitor commands to
817 change or eject media.
819 @node disk_images_fat_images
820 @subsection Virtual FAT disk images
822 QEMU can automatically create a virtual FAT disk image from a
823 directory tree. In order to use it, just type:
826 qemu-system-i386 linux.img -hdb fat:/my_directory
829 Then you access access to all the files in the @file{/my_directory}
830 directory without having to copy them in a disk image or to export
831 them via SAMBA or NFS. The default access is @emph{read-only}.
833 Floppies can be emulated with the @code{:floppy:} option:
836 qemu-system-i386 linux.img -fda fat:floppy:/my_directory
839 A read/write support is available for testing (beta stage) with the
843 qemu-system-i386 linux.img -fda fat:floppy:rw:/my_directory
846 What you should @emph{never} do:
848 @item use non-ASCII filenames ;
849 @item use "-snapshot" together with ":rw:" ;
850 @item expect it to work when loadvm'ing ;
851 @item write to the FAT directory on the host system while accessing it with the guest system.
854 @node disk_images_nbd
855 @subsection NBD access
857 QEMU can access directly to block device exported using the Network Block Device
861 qemu-system-i386 linux.img -hdb nbd://my_nbd_server.mydomain.org:1024/
864 If the NBD server is located on the same host, you can use an unix socket instead
868 qemu-system-i386 linux.img -hdb nbd+unix://?socket=/tmp/my_socket
871 In this case, the block device must be exported using qemu-nbd:
874 qemu-nbd --socket=/tmp/my_socket my_disk.qcow2
877 The use of qemu-nbd allows sharing of a disk between several guests:
879 qemu-nbd --socket=/tmp/my_socket --share=2 my_disk.qcow2
883 and then you can use it with two guests:
885 qemu-system-i386 linux1.img -hdb nbd+unix://?socket=/tmp/my_socket
886 qemu-system-i386 linux2.img -hdb nbd+unix://?socket=/tmp/my_socket
889 If the nbd-server uses named exports (supported since NBD 2.9.18, or with QEMU's
890 own embedded NBD server), you must specify an export name in the URI:
892 qemu-system-i386 -cdrom nbd://localhost/debian-500-ppc-netinst
893 qemu-system-i386 -cdrom nbd://localhost/openSUSE-11.1-ppc-netinst
896 The URI syntax for NBD is supported since QEMU 1.3. An alternative syntax is
897 also available. Here are some example of the older syntax:
899 qemu-system-i386 linux.img -hdb nbd:my_nbd_server.mydomain.org:1024
900 qemu-system-i386 linux2.img -hdb nbd:unix:/tmp/my_socket
901 qemu-system-i386 -cdrom nbd:localhost:10809:exportname=debian-500-ppc-netinst
904 @node disk_images_sheepdog
905 @subsection Sheepdog disk images
907 Sheepdog is a distributed storage system for QEMU. It provides highly
908 available block level storage volumes that can be attached to
909 QEMU-based virtual machines.
911 You can create a Sheepdog disk image with the command:
913 qemu-img create sheepdog:///@var{image} @var{size}
915 where @var{image} is the Sheepdog image name and @var{size} is its
918 To import the existing @var{filename} to Sheepdog, you can use a
921 qemu-img convert @var{filename} sheepdog:///@var{image}
924 You can boot from the Sheepdog disk image with the command:
926 qemu-system-i386 sheepdog:///@var{image}
929 You can also create a snapshot of the Sheepdog image like qcow2.
931 qemu-img snapshot -c @var{tag} sheepdog:///@var{image}
933 where @var{tag} is a tag name of the newly created snapshot.
935 To boot from the Sheepdog snapshot, specify the tag name of the
938 qemu-system-i386 sheepdog:///@var{image}#@var{tag}
941 You can create a cloned image from the existing snapshot.
943 qemu-img create -b sheepdog:///@var{base}#@var{tag} sheepdog:///@var{image}
945 where @var{base} is a image name of the source snapshot and @var{tag}
948 You can use an unix socket instead of an inet socket:
951 qemu-system-i386 sheepdog+unix:///@var{image}?socket=@var{path}
954 If the Sheepdog daemon doesn't run on the local host, you need to
955 specify one of the Sheepdog servers to connect to.
957 qemu-img create sheepdog://@var{hostname}:@var{port}/@var{image} @var{size}
958 qemu-system-i386 sheepdog://@var{hostname}:@var{port}/@var{image}
961 @node disk_images_iscsi
962 @subsection iSCSI LUNs
964 iSCSI is a popular protocol used to access SCSI devices across a computer
967 There are two different ways iSCSI devices can be used by QEMU.
969 The first method is to mount the iSCSI LUN on the host, and make it appear as
970 any other ordinary SCSI device on the host and then to access this device as a
971 /dev/sd device from QEMU. How to do this differs between host OSes.
973 The second method involves using the iSCSI initiator that is built into
974 QEMU. This provides a mechanism that works the same way regardless of which
975 host OS you are running QEMU on. This section will describe this second method
976 of using iSCSI together with QEMU.
978 In QEMU, iSCSI devices are described using special iSCSI URLs
982 iscsi://[<username>[%<password>]@@]<host>[:<port>]/<target-iqn-name>/<lun>
985 Username and password are optional and only used if your target is set up
986 using CHAP authentication for access control.
987 Alternatively the username and password can also be set via environment
988 variables to have these not show up in the process list
991 export LIBISCSI_CHAP_USERNAME=<username>
992 export LIBISCSI_CHAP_PASSWORD=<password>
993 iscsi://<host>/<target-iqn-name>/<lun>
996 Various session related parameters can be set via special options, either
997 in a configuration file provided via '-readconfig' or directly on the
1000 If the initiator-name is not specified qemu will use a default name
1001 of 'iqn.2008-11.org.linux-kvm[:<name>'] where <name> is the name of the
1006 Setting a specific initiator name to use when logging in to the target
1007 -iscsi initiator-name=iqn.qemu.test:my-initiator
1011 Controlling which type of header digest to negotiate with the target
1012 -iscsi header-digest=CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1015 These can also be set via a configuration file
1018 user = "CHAP username"
1019 password = "CHAP password"
1020 initiator-name = "iqn.qemu.test:my-initiator"
1021 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1022 header-digest = "CRC32C"
1026 Setting the target name allows different options for different targets
1028 [iscsi "iqn.target.name"]
1029 user = "CHAP username"
1030 password = "CHAP password"
1031 initiator-name = "iqn.qemu.test:my-initiator"
1032 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1033 header-digest = "CRC32C"
1037 Howto use a configuration file to set iSCSI configuration options:
1039 cat >iscsi.conf <<EOF
1042 password = "my password"
1043 initiator-name = "iqn.qemu.test:my-initiator"
1044 header-digest = "CRC32C"
1047 qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1048 -readconfig iscsi.conf
1052 Howto set up a simple iSCSI target on loopback and accessing it via QEMU:
1054 This example shows how to set up an iSCSI target with one CDROM and one DISK
1055 using the Linux STGT software target. This target is available on Red Hat based
1056 systems as the package 'scsi-target-utils'.
1058 tgtd --iscsi portal=127.0.0.1:3260
1059 tgtadm --lld iscsi --op new --mode target --tid 1 -T iqn.qemu.test
1060 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 \
1061 -b /IMAGES/disk.img --device-type=disk
1062 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 \
1063 -b /IMAGES/cd.iso --device-type=cd
1064 tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL
1066 qemu-system-i386 -iscsi initiator-name=iqn.qemu.test:my-initiator \
1067 -boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1068 -cdrom iscsi://127.0.0.1/iqn.qemu.test/2
1071 @node disk_images_gluster
1072 @subsection GlusterFS disk images
1074 GlusterFS is an user space distributed file system.
1076 You can boot from the GlusterFS disk image with the command:
1078 qemu-system-x86_64 -drive file=gluster[+@var{transport}]://[@var{server}[:@var{port}]]/@var{volname}/@var{image}[?socket=...]
1081 @var{gluster} is the protocol.
1083 @var{transport} specifies the transport type used to connect to gluster
1084 management daemon (glusterd). Valid transport types are
1085 tcp, unix and rdma. If a transport type isn't specified, then tcp
1088 @var{server} specifies the server where the volume file specification for
1089 the given volume resides. This can be either hostname, ipv4 address
1090 or ipv6 address. ipv6 address needs to be within square brackets [ ].
1091 If transport type is unix, then @var{server} field should not be specified.
1092 Instead @var{socket} field needs to be populated with the path to unix domain
1095 @var{port} is the port number on which glusterd is listening. This is optional
1096 and if not specified, QEMU will send 0 which will make gluster to use the
1097 default port. If the transport type is unix, then @var{port} should not be
1100 @var{volname} is the name of the gluster volume which contains the disk image.
1102 @var{image} is the path to the actual disk image that resides on gluster volume.
1104 You can create a GlusterFS disk image with the command:
1106 qemu-img create gluster://@var{server}/@var{volname}/@var{image} @var{size}
1111 qemu-system-x86_64 -drive file=gluster://1.2.3.4/testvol/a.img
1112 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4/testvol/a.img
1113 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img
1114 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
1115 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img
1116 qemu-system-x86_64 -drive file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img
1117 qemu-system-x86_64 -drive file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
1118 qemu-system-x86_64 -drive file=gluster+rdma://1.2.3.4:24007/testvol/a.img
1121 @node disk_images_ssh
1122 @subsection Secure Shell (ssh) disk images
1124 You can access disk images located on a remote ssh server
1125 by using the ssh protocol:
1128 qemu-system-x86_64 -drive file=ssh://[@var{user}@@]@var{server}[:@var{port}]/@var{path}[?host_key_check=@var{host_key_check}]
1131 Alternative syntax using properties:
1134 qemu-system-x86_64 -drive file.driver=ssh[,file.user=@var{user}],file.host=@var{server}[,file.port=@var{port}],file.path=@var{path}[,file.host_key_check=@var{host_key_check}]
1137 @var{ssh} is the protocol.
1139 @var{user} is the remote user. If not specified, then the local
1142 @var{server} specifies the remote ssh server. Any ssh server can be
1143 used, but it must implement the sftp-server protocol. Most Unix/Linux
1144 systems should work without requiring any extra configuration.
1146 @var{port} is the port number on which sshd is listening. By default
1147 the standard ssh port (22) is used.
1149 @var{path} is the path to the disk image.
1151 The optional @var{host_key_check} parameter controls how the remote
1152 host's key is checked. The default is @code{yes} which means to use
1153 the local @file{.ssh/known_hosts} file. Setting this to @code{no}
1154 turns off known-hosts checking. Or you can check that the host key
1155 matches a specific fingerprint:
1156 @code{host_key_check=md5:78:45:8e:14:57:4f:d5:45:83:0a:0e:f3:49:82:c9:c8}
1157 (@code{sha1:} can also be used as a prefix, but note that OpenSSH
1158 tools only use MD5 to print fingerprints).
1160 Currently authentication must be done using ssh-agent. Other
1161 authentication methods may be supported in future.
1163 Note: Many ssh servers do not support an @code{fsync}-style operation.
1164 The ssh driver cannot guarantee that disk flush requests are
1165 obeyed, and this causes a risk of disk corruption if the remote
1166 server or network goes down during writes. The driver will
1167 print a warning when @code{fsync} is not supported:
1169 warning: ssh server @code{ssh.example.com:22} does not support fsync
1171 With sufficiently new versions of libssh2 and OpenSSH, @code{fsync} is
1175 @section Network emulation
1177 QEMU can simulate several network cards (PCI or ISA cards on the PC
1178 target) and can connect them to an arbitrary number of Virtual Local
1179 Area Networks (VLANs). Host TAP devices can be connected to any QEMU
1180 VLAN. VLAN can be connected between separate instances of QEMU to
1181 simulate large networks. For simpler usage, a non privileged user mode
1182 network stack can replace the TAP device to have a basic network
1187 QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
1188 connection between several network devices. These devices can be for
1189 example QEMU virtual Ethernet cards or virtual Host ethernet devices
1192 @subsection Using TAP network interfaces
1194 This is the standard way to connect QEMU to a real network. QEMU adds
1195 a virtual network device on your host (called @code{tapN}), and you
1196 can then configure it as if it was a real ethernet card.
1198 @subsubsection Linux host
1200 As an example, you can download the @file{linux-test-xxx.tar.gz}
1201 archive and copy the script @file{qemu-ifup} in @file{/etc} and
1202 configure properly @code{sudo} so that the command @code{ifconfig}
1203 contained in @file{qemu-ifup} can be executed as root. You must verify
1204 that your host kernel supports the TAP network interfaces: the
1205 device @file{/dev/net/tun} must be present.
1207 See @ref{sec_invocation} to have examples of command lines using the
1208 TAP network interfaces.
1210 @subsubsection Windows host
1212 There is a virtual ethernet driver for Windows 2000/XP systems, called
1213 TAP-Win32. But it is not included in standard QEMU for Windows,
1214 so you will need to get it separately. It is part of OpenVPN package,
1215 so download OpenVPN from : @url{http://openvpn.net/}.
1217 @subsection Using the user mode network stack
1219 By using the option @option{-net user} (default configuration if no
1220 @option{-net} option is specified), QEMU uses a completely user mode
1221 network stack (you don't need root privilege to use the virtual
1222 network). The virtual network configuration is the following:
1226 QEMU VLAN <------> Firewall/DHCP server <-----> Internet
1229 ----> DNS server (10.0.2.3)
1231 ----> SMB server (10.0.2.4)
1234 The QEMU VM behaves as if it was behind a firewall which blocks all
1235 incoming connections. You can use a DHCP client to automatically
1236 configure the network in the QEMU VM. The DHCP server assign addresses
1237 to the hosts starting from 10.0.2.15.
1239 In order to check that the user mode network is working, you can ping
1240 the address 10.0.2.2 and verify that you got an address in the range
1241 10.0.2.x from the QEMU virtual DHCP server.
1243 Note that ICMP traffic in general does not work with user mode networking.
1244 @code{ping}, aka. ICMP echo, to the local router (10.0.2.2) shall work,
1245 however. If you're using QEMU on Linux >= 3.0, it can use unprivileged ICMP
1246 ping sockets to allow @code{ping} to the Internet. The host admin has to set
1247 the ping_group_range in order to grant access to those sockets. To allow ping
1248 for GID 100 (usually users group):
1251 echo 100 100 > /proc/sys/net/ipv4/ping_group_range
1254 When using the built-in TFTP server, the router is also the TFTP
1257 When using the @option{'-netdev user,hostfwd=...'} option, TCP or UDP
1258 connections can be redirected from the host to the guest. It allows for
1259 example to redirect X11, telnet or SSH connections.
1261 @subsection Connecting VLANs between QEMU instances
1263 Using the @option{-net socket} option, it is possible to make VLANs
1264 that span several QEMU instances. See @ref{sec_invocation} to have a
1267 @node pcsys_other_devs
1268 @section Other Devices
1270 @subsection Inter-VM Shared Memory device
1272 On Linux hosts, a shared memory device is available. The basic syntax
1276 qemu-system-x86_64 -device ivshmem-plain,memdev=@var{hostmem}
1279 where @var{hostmem} names a host memory backend. For a POSIX shared
1280 memory backend, use something like
1283 -object memory-backend-file,size=1M,share,mem-path=/dev/shm/ivshmem,id=@var{hostmem}
1286 If desired, interrupts can be sent between guest VMs accessing the same shared
1287 memory region. Interrupt support requires using a shared memory server and
1288 using a chardev socket to connect to it. The code for the shared memory server
1289 is qemu.git/contrib/ivshmem-server. An example syntax when using the shared
1293 # First start the ivshmem server once and for all
1294 ivshmem-server -p @var{pidfile} -S @var{path} -m @var{shm-name} -l @var{shm-size} -n @var{vectors}
1296 # Then start your qemu instances with matching arguments
1297 qemu-system-x86_64 -device ivshmem-doorbell,vectors=@var{vectors},chardev=@var{id}
1298 -chardev socket,path=@var{path},id=@var{id}
1301 When using the server, the guest will be assigned a VM ID (>=0) that allows guests
1302 using the same server to communicate via interrupts. Guests can read their
1303 VM ID from a device register (see ivshmem-spec.txt).
1305 @subsubsection Migration with ivshmem
1307 With device property @option{master=on}, the guest will copy the shared
1308 memory on migration to the destination host. With @option{master=off},
1309 the guest will not be able to migrate with the device attached. In the
1310 latter case, the device should be detached and then reattached after
1311 migration using the PCI hotplug support.
1313 At most one of the devices sharing the same memory can be master. The
1314 master must complete migration before you plug back the other devices.
1316 @subsubsection ivshmem and hugepages
1318 Instead of specifying the <shm size> using POSIX shm, you may specify
1319 a memory backend that has hugepage support:
1322 qemu-system-x86_64 -object memory-backend-file,size=1G,mem-path=/dev/hugepages/my-shmem-file,share,id=mb1
1323 -device ivshmem-plain,memdev=mb1
1326 ivshmem-server also supports hugepages mount points with the
1327 @option{-m} memory path argument.
1329 @node direct_linux_boot
1330 @section Direct Linux Boot
1332 This section explains how to launch a Linux kernel inside QEMU without
1333 having to make a full bootable image. It is very useful for fast Linux
1338 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
1341 Use @option{-kernel} to provide the Linux kernel image and
1342 @option{-append} to give the kernel command line arguments. The
1343 @option{-initrd} option can be used to provide an INITRD image.
1345 When using the direct Linux boot, a disk image for the first hard disk
1346 @file{hda} is required because its boot sector is used to launch the
1349 If you do not need graphical output, you can disable it and redirect
1350 the virtual serial port and the QEMU monitor to the console with the
1351 @option{-nographic} option. The typical command line is:
1353 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1354 -append "root=/dev/hda console=ttyS0" -nographic
1357 Use @key{Ctrl-a c} to switch between the serial console and the
1358 monitor (@pxref{pcsys_keys}).
1361 @section USB emulation
1363 QEMU emulates a PCI UHCI USB controller. You can virtually plug
1364 virtual USB devices or real host USB devices (experimental, works only
1365 on Linux hosts). QEMU will automatically create and connect virtual USB hubs
1366 as necessary to connect multiple USB devices.
1370 * host_usb_devices::
1373 @subsection Connecting USB devices
1375 USB devices can be connected with the @option{-usbdevice} commandline option
1376 or the @code{usb_add} monitor command. Available devices are:
1380 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1382 Pointer device that uses absolute coordinates (like a touchscreen).
1383 This means QEMU is able to report the mouse position without having
1384 to grab the mouse. Also overrides the PS/2 mouse emulation when activated.
1385 @item disk:@var{file}
1386 Mass storage device based on @var{file} (@pxref{disk_images})
1387 @item host:@var{bus.addr}
1388 Pass through the host device identified by @var{bus.addr}
1390 @item host:@var{vendor_id:product_id}
1391 Pass through the host device identified by @var{vendor_id:product_id}
1394 Virtual Wacom PenPartner tablet. This device is similar to the @code{tablet}
1395 above but it can be used with the tslib library because in addition to touch
1396 coordinates it reports touch pressure.
1398 Standard USB keyboard. Will override the PS/2 keyboard (if present).
1399 @item serial:[vendorid=@var{vendor_id}][,product_id=@var{product_id}]:@var{dev}
1400 Serial converter. This emulates an FTDI FT232BM chip connected to host character
1401 device @var{dev}. The available character devices are the same as for the
1402 @code{-serial} option. The @code{vendorid} and @code{productid} options can be
1403 used to override the default 0403:6001. For instance,
1405 usb_add serial:productid=FA00:tcp:192.168.0.2:4444
1407 will connect to tcp port 4444 of ip 192.168.0.2, and plug that to the virtual
1408 serial converter, faking a Matrix Orbital LCD Display (USB ID 0403:FA00).
1410 Braille device. This will use BrlAPI to display the braille output on a real
1412 @item net:@var{options}
1413 Network adapter that supports CDC ethernet and RNDIS protocols. @var{options}
1414 specifies NIC options as with @code{-net nic,}@var{options} (see description).
1415 For instance, user-mode networking can be used with
1417 qemu-system-i386 [...OPTIONS...] -net user,vlan=0 -usbdevice net:vlan=0
1419 Currently this cannot be used in machines that support PCI NICs.
1420 @item bt[:@var{hci-type}]
1421 Bluetooth dongle whose type is specified in the same format as with
1422 the @option{-bt hci} option, @pxref{bt-hcis,,allowed HCI types}. If
1423 no type is given, the HCI logic corresponds to @code{-bt hci,vlan=0}.
1424 This USB device implements the USB Transport Layer of HCI. Example
1427 @command{qemu-system-i386} [...@var{OPTIONS}...] @option{-usbdevice} bt:hci,vlan=3 @option{-bt} device:keyboard,vlan=3
1431 @node host_usb_devices
1432 @subsection Using host USB devices on a Linux host
1434 WARNING: this is an experimental feature. QEMU will slow down when
1435 using it. USB devices requiring real time streaming (i.e. USB Video
1436 Cameras) are not supported yet.
1439 @item If you use an early Linux 2.4 kernel, verify that no Linux driver
1440 is actually using the USB device. A simple way to do that is simply to
1441 disable the corresponding kernel module by renaming it from @file{mydriver.o}
1442 to @file{mydriver.o.disabled}.
1444 @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1450 @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:
1452 chown -R myuid /proc/bus/usb
1455 @item Launch QEMU and do in the monitor:
1458 Device 1.2, speed 480 Mb/s
1459 Class 00: USB device 1234:5678, USB DISK
1461 You should see the list of the devices you can use (Never try to use
1462 hubs, it won't work).
1464 @item Add the device in QEMU by using:
1466 usb_add host:1234:5678
1469 Normally the guest OS should report that a new USB device is
1470 plugged. You can use the option @option{-usbdevice} to do the same.
1472 @item Now you can try to use the host USB device in QEMU.
1476 When relaunching QEMU, you may have to unplug and plug again the USB
1477 device to make it work again (this is a bug).
1480 @section VNC security
1482 The VNC server capability provides access to the graphical console
1483 of the guest VM across the network. This has a number of security
1484 considerations depending on the deployment scenarios.
1488 * vnc_sec_password::
1489 * vnc_sec_certificate::
1490 * vnc_sec_certificate_verify::
1491 * vnc_sec_certificate_pw::
1493 * vnc_sec_certificate_sasl::
1494 * vnc_generate_cert::
1498 @subsection Without passwords
1500 The simplest VNC server setup does not include any form of authentication.
1501 For this setup it is recommended to restrict it to listen on a UNIX domain
1502 socket only. For example
1505 qemu-system-i386 [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
1508 This ensures that only users on local box with read/write access to that
1509 path can access the VNC server. To securely access the VNC server from a
1510 remote machine, a combination of netcat+ssh can be used to provide a secure
1513 @node vnc_sec_password
1514 @subsection With passwords
1516 The VNC protocol has limited support for password based authentication. Since
1517 the protocol limits passwords to 8 characters it should not be considered
1518 to provide high security. The password can be fairly easily brute-forced by
1519 a client making repeat connections. For this reason, a VNC server using password
1520 authentication should be restricted to only listen on the loopback interface
1521 or UNIX domain sockets. Password authentication is not supported when operating
1522 in FIPS 140-2 compliance mode as it requires the use of the DES cipher. Password
1523 authentication is requested with the @code{password} option, and then once QEMU
1524 is running the password is set with the monitor. Until the monitor is used to
1525 set the password all clients will be rejected.
1528 qemu-system-i386 [...OPTIONS...] -vnc :1,password -monitor stdio
1529 (qemu) change vnc password
1534 @node vnc_sec_certificate
1535 @subsection With x509 certificates
1537 The QEMU VNC server also implements the VeNCrypt extension allowing use of
1538 TLS for encryption of the session, and x509 certificates for authentication.
1539 The use of x509 certificates is strongly recommended, because TLS on its
1540 own is susceptible to man-in-the-middle attacks. Basic x509 certificate
1541 support provides a secure session, but no authentication. This allows any
1542 client to connect, and provides an encrypted session.
1545 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio
1548 In the above example @code{/etc/pki/qemu} should contain at least three files,
1549 @code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged
1550 users will want to use a private directory, for example @code{$HOME/.pki/qemu}.
1551 NB the @code{server-key.pem} file should be protected with file mode 0600 to
1552 only be readable by the user owning it.
1554 @node vnc_sec_certificate_verify
1555 @subsection With x509 certificates and client verification
1557 Certificates can also provide a means to authenticate the client connecting.
1558 The server will request that the client provide a certificate, which it will
1559 then validate against the CA certificate. This is a good choice if deploying
1560 in an environment with a private internal certificate authority.
1563 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
1567 @node vnc_sec_certificate_pw
1568 @subsection With x509 certificates, client verification and passwords
1570 Finally, the previous method can be combined with VNC password authentication
1571 to provide two layers of authentication for clients.
1574 qemu-system-i386 [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
1575 (qemu) change vnc password
1582 @subsection With SASL authentication
1584 The SASL authentication method is a VNC extension, that provides an
1585 easily extendable, pluggable authentication method. This allows for
1586 integration with a wide range of authentication mechanisms, such as
1587 PAM, GSSAPI/Kerberos, LDAP, SQL databases, one-time keys and more.
1588 The strength of the authentication depends on the exact mechanism
1589 configured. If the chosen mechanism also provides a SSF layer, then
1590 it will encrypt the datastream as well.
1592 Refer to the later docs on how to choose the exact SASL mechanism
1593 used for authentication, but assuming use of one supporting SSF,
1594 then QEMU can be launched with:
1597 qemu-system-i386 [...OPTIONS...] -vnc :1,sasl -monitor stdio
1600 @node vnc_sec_certificate_sasl
1601 @subsection With x509 certificates and SASL authentication
1603 If the desired SASL authentication mechanism does not supported
1604 SSF layers, then it is strongly advised to run it in combination
1605 with TLS and x509 certificates. This provides securely encrypted
1606 data stream, avoiding risk of compromising of the security
1607 credentials. This can be enabled, by combining the 'sasl' option
1608 with the aforementioned TLS + x509 options:
1611 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509,sasl -monitor stdio
1615 @node vnc_generate_cert
1616 @subsection Generating certificates for VNC
1618 The GNU TLS packages provides a command called @code{certtool} which can
1619 be used to generate certificates and keys in PEM format. At a minimum it
1620 is necessary to setup a certificate authority, and issue certificates to
1621 each server. If using certificates for authentication, then each client
1622 will also need to be issued a certificate. The recommendation is for the
1623 server to keep its certificates in either @code{/etc/pki/qemu} or for
1624 unprivileged users in @code{$HOME/.pki/qemu}.
1628 * vnc_generate_server::
1629 * vnc_generate_client::
1631 @node vnc_generate_ca
1632 @subsubsection Setup the Certificate Authority
1634 This step only needs to be performed once per organization / organizational
1635 unit. First the CA needs a private key. This key must be kept VERY secret
1636 and secure. If this key is compromised the entire trust chain of the certificates
1637 issued with it is lost.
1640 # certtool --generate-privkey > ca-key.pem
1643 A CA needs to have a public certificate. For simplicity it can be a self-signed
1644 certificate, or one issue by a commercial certificate issuing authority. To
1645 generate a self-signed certificate requires one core piece of information, the
1646 name of the organization.
1649 # cat > ca.info <<EOF
1650 cn = Name of your organization
1654 # certtool --generate-self-signed \
1655 --load-privkey ca-key.pem
1656 --template ca.info \
1657 --outfile ca-cert.pem
1660 The @code{ca-cert.pem} file should be copied to all servers and clients wishing to utilize
1661 TLS support in the VNC server. The @code{ca-key.pem} must not be disclosed/copied at all.
1663 @node vnc_generate_server
1664 @subsubsection Issuing server certificates
1666 Each server (or host) needs to be issued with a key and certificate. When connecting
1667 the certificate is sent to the client which validates it against the CA certificate.
1668 The core piece of information for a server certificate is the hostname. This should
1669 be the fully qualified hostname that the client will connect with, since the client
1670 will typically also verify the hostname in the certificate. On the host holding the
1671 secure CA private key:
1674 # cat > server.info <<EOF
1675 organization = Name of your organization
1676 cn = server.foo.example.com
1681 # certtool --generate-privkey > server-key.pem
1682 # certtool --generate-certificate \
1683 --load-ca-certificate ca-cert.pem \
1684 --load-ca-privkey ca-key.pem \
1685 --load-privkey server-key.pem \
1686 --template server.info \
1687 --outfile server-cert.pem
1690 The @code{server-key.pem} and @code{server-cert.pem} files should now be securely copied
1691 to the server for which they were generated. The @code{server-key.pem} is security
1692 sensitive and should be kept protected with file mode 0600 to prevent disclosure.
1694 @node vnc_generate_client
1695 @subsubsection Issuing client certificates
1697 If the QEMU VNC server is to use the @code{x509verify} option to validate client
1698 certificates as its authentication mechanism, each client also needs to be issued
1699 a certificate. The client certificate contains enough metadata to uniquely identify
1700 the client, typically organization, state, city, building, etc. On the host holding
1701 the secure CA private key:
1704 # cat > client.info <<EOF
1708 organization = Name of your organization
1709 cn = client.foo.example.com
1714 # certtool --generate-privkey > client-key.pem
1715 # certtool --generate-certificate \
1716 --load-ca-certificate ca-cert.pem \
1717 --load-ca-privkey ca-key.pem \
1718 --load-privkey client-key.pem \
1719 --template client.info \
1720 --outfile client-cert.pem
1723 The @code{client-key.pem} and @code{client-cert.pem} files should now be securely
1724 copied to the client for which they were generated.
1727 @node vnc_setup_sasl
1729 @subsection Configuring SASL mechanisms
1731 The following documentation assumes use of the Cyrus SASL implementation on a
1732 Linux host, but the principals should apply to any other SASL impl. When SASL
1733 is enabled, the mechanism configuration will be loaded from system default
1734 SASL service config /etc/sasl2/qemu.conf. If running QEMU as an
1735 unprivileged user, an environment variable SASL_CONF_PATH can be used
1736 to make it search alternate locations for the service config.
1738 The default configuration might contain
1741 mech_list: digest-md5
1742 sasldb_path: /etc/qemu/passwd.db
1745 This says to use the 'Digest MD5' mechanism, which is similar to the HTTP
1746 Digest-MD5 mechanism. The list of valid usernames & passwords is maintained
1747 in the /etc/qemu/passwd.db file, and can be updated using the saslpasswd2
1748 command. While this mechanism is easy to configure and use, it is not
1749 considered secure by modern standards, so only suitable for developers /
1752 A more serious deployment might use Kerberos, which is done with the 'gssapi'
1757 keytab: /etc/qemu/krb5.tab
1760 For this to work the administrator of your KDC must generate a Kerberos
1761 principal for the server, with a name of 'qemu/somehost.example.com@@EXAMPLE.COM'
1762 replacing 'somehost.example.com' with the fully qualified host name of the
1763 machine running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.
1765 Other configurations will be left as an exercise for the reader. It should
1766 be noted that only Digest-MD5 and GSSAPI provides a SSF layer for data
1767 encryption. For all other mechanisms, VNC should always be configured to
1768 use TLS and x509 certificates to protect security credentials from snooping.
1773 QEMU has a primitive support to work with gdb, so that you can do
1774 'Ctrl-C' while the virtual machine is running and inspect its state.
1776 In order to use gdb, launch QEMU with the '-s' option. It will wait for a
1779 qemu-system-i386 -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1780 -append "root=/dev/hda"
1781 Connected to host network interface: tun0
1782 Waiting gdb connection on port 1234
1785 Then launch gdb on the 'vmlinux' executable:
1790 In gdb, connect to QEMU:
1792 (gdb) target remote localhost:1234
1795 Then you can use gdb normally. For example, type 'c' to launch the kernel:
1800 Here are some useful tips in order to use gdb on system code:
1804 Use @code{info reg} to display all the CPU registers.
1806 Use @code{x/10i $eip} to display the code at the PC position.
1808 Use @code{set architecture i8086} to dump 16 bit code. Then use
1809 @code{x/10i $cs*16+$eip} to dump the code at the PC position.
1812 Advanced debugging options:
1814 The 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:
1816 @item maintenance packet qqemu.sstepbits
1818 This will display the MASK bits used to control the single stepping IE:
1820 (gdb) maintenance packet qqemu.sstepbits
1821 sending: "qqemu.sstepbits"
1822 received: "ENABLE=1,NOIRQ=2,NOTIMER=4"
1824 @item maintenance packet qqemu.sstep
1826 This will display the current value of the mask used when single stepping IE:
1828 (gdb) maintenance packet qqemu.sstep
1829 sending: "qqemu.sstep"
1832 @item maintenance packet Qqemu.sstep=HEX_VALUE
1834 This will change the single step mask, so if wanted to enable IRQs on the single step, but not timers, you would use:
1836 (gdb) maintenance packet Qqemu.sstep=0x5
1837 sending: "qemu.sstep=0x5"
1842 @node pcsys_os_specific
1843 @section Target OS specific information
1847 To have access to SVGA graphic modes under X11, use the @code{vesa} or
1848 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1849 color depth in the guest and the host OS.
1851 When using a 2.6 guest Linux kernel, you should add the option
1852 @code{clock=pit} on the kernel command line because the 2.6 Linux
1853 kernels make very strict real time clock checks by default that QEMU
1854 cannot simulate exactly.
1856 When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1857 not activated because QEMU is slower with this patch. The QEMU
1858 Accelerator Module is also much slower in this case. Earlier Fedora
1859 Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this
1860 patch by default. Newer kernels don't have it.
1864 If you have a slow host, using Windows 95 is better as it gives the
1865 best speed. Windows 2000 is also a good choice.
1867 @subsubsection SVGA graphic modes support
1869 QEMU emulates a Cirrus Logic GD5446 Video
1870 card. All Windows versions starting from Windows 95 should recognize
1871 and use this graphic card. For optimal performances, use 16 bit color
1872 depth in the guest and the host OS.
1874 If you are using Windows XP as guest OS and if you want to use high
1875 resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
1876 1280x1024x16), then you should use the VESA VBE virtual graphic card
1877 (option @option{-std-vga}).
1879 @subsubsection CPU usage reduction
1881 Windows 9x does not correctly use the CPU HLT
1882 instruction. The result is that it takes host CPU cycles even when
1883 idle. You can install the utility from
1884 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
1885 problem. Note that no such tool is needed for NT, 2000 or XP.
1887 @subsubsection Windows 2000 disk full problem
1889 Windows 2000 has a bug which gives a disk full problem during its
1890 installation. When installing it, use the @option{-win2k-hack} QEMU
1891 option to enable a specific workaround. After Windows 2000 is
1892 installed, you no longer need this option (this option slows down the
1895 @subsubsection Windows 2000 shutdown
1897 Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1898 can. It comes from the fact that Windows 2000 does not automatically
1899 use the APM driver provided by the BIOS.
1901 In order to correct that, do the following (thanks to Struan
1902 Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1903 Add/Troubleshoot a device => Add a new device & Next => No, select the
1904 hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1905 (again) a few times. Now the driver is installed and Windows 2000 now
1906 correctly instructs QEMU to shutdown at the appropriate moment.
1908 @subsubsection Share a directory between Unix and Windows
1910 See @ref{sec_invocation} about the help of the option
1911 @option{'-netdev user,smb=...'}.
1913 @subsubsection Windows XP security problem
1915 Some releases of Windows XP install correctly but give a security
1918 A problem is preventing Windows from accurately checking the
1919 license for this computer. Error code: 0x800703e6.
1922 The workaround is to install a service pack for XP after a boot in safe
1923 mode. Then reboot, and the problem should go away. Since there is no
1924 network while in safe mode, its recommended to download the full
1925 installation of SP1 or SP2 and transfer that via an ISO or using the
1926 vvfat block device ("-hdb fat:directory_which_holds_the_SP").
1928 @subsection MS-DOS and FreeDOS
1930 @subsubsection CPU usage reduction
1932 DOS does not correctly use the CPU HLT instruction. The result is that
1933 it takes host CPU cycles even when idle. You can install the utility
1934 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1937 @node QEMU System emulator for non PC targets
1938 @chapter QEMU System emulator for non PC targets
1940 QEMU is a generic emulator and it emulates many non PC
1941 machines. Most of the options are similar to the PC emulator. The
1942 differences are mentioned in the following sections.
1945 * PowerPC System emulator::
1946 * Sparc32 System emulator::
1947 * Sparc64 System emulator::
1948 * MIPS System emulator::
1949 * ARM System emulator::
1950 * ColdFire System emulator::
1951 * Cris System emulator::
1952 * Microblaze System emulator::
1953 * SH4 System emulator::
1954 * Xtensa System emulator::
1957 @node PowerPC System emulator
1958 @section PowerPC System emulator
1959 @cindex system emulation (PowerPC)
1961 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1962 or PowerMac PowerPC system.
1964 QEMU emulates the following PowerMac peripherals:
1968 UniNorth or Grackle PCI Bridge
1970 PCI VGA compatible card with VESA Bochs Extensions
1972 2 PMAC IDE interfaces with hard disk and CD-ROM support
1978 VIA-CUDA with ADB keyboard and mouse.
1981 QEMU emulates the following PREP peripherals:
1987 PCI VGA compatible card with VESA Bochs Extensions
1989 2 IDE interfaces with hard disk and CD-ROM support
1993 NE2000 network adapters
1997 PREP Non Volatile RAM
1999 PC compatible keyboard and mouse.
2002 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
2003 @url{http://perso.magic.fr/l_indien/OpenHackWare/index.htm}.
2005 Since version 0.9.1, QEMU uses OpenBIOS @url{http://www.openbios.org/}
2006 for the g3beige and mac99 PowerMac machines. OpenBIOS is a free (GPL
2007 v2) portable firmware implementation. The goal is to implement a 100%
2008 IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.
2010 @c man begin OPTIONS
2012 The following options are specific to the PowerPC emulation:
2016 @item -g @var{W}x@var{H}[x@var{DEPTH}]
2018 Set the initial VGA graphic mode. The default is 800x600x32.
2020 @item -prom-env @var{string}
2022 Set OpenBIOS variables in NVRAM, for example:
2025 qemu-system-ppc -prom-env 'auto-boot?=false' \
2026 -prom-env 'boot-device=hd:2,\yaboot' \
2027 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
2030 These variables are not used by Open Hack'Ware.
2037 More information is available at
2038 @url{http://perso.magic.fr/l_indien/qemu-ppc/}.
2040 @node Sparc32 System emulator
2041 @section Sparc32 System emulator
2042 @cindex system emulation (Sparc32)
2044 Use the executable @file{qemu-system-sparc} to simulate the following
2045 Sun4m architecture machines:
2060 SPARCstation Voyager
2067 The emulation is somewhat complete. SMP up to 16 CPUs is supported,
2068 but Linux limits the number of usable CPUs to 4.
2070 QEMU emulates the following sun4m peripherals:
2076 TCX or cgthree Frame buffer
2078 Lance (Am7990) Ethernet
2080 Non Volatile RAM M48T02/M48T08
2082 Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
2083 and power/reset logic
2085 ESP SCSI controller with hard disk and CD-ROM support
2087 Floppy drive (not on SS-600MP)
2089 CS4231 sound device (only on SS-5, not working yet)
2092 The number of peripherals is fixed in the architecture. Maximum
2093 memory size depends on the machine type, for SS-5 it is 256MB and for
2096 Since version 0.8.2, QEMU uses OpenBIOS
2097 @url{http://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
2098 firmware implementation. The goal is to implement a 100% IEEE
2099 1275-1994 (referred to as Open Firmware) compliant firmware.
2101 A sample Linux 2.6 series kernel and ram disk image are available on
2102 the QEMU web site. There are still issues with NetBSD and OpenBSD, but
2103 most kernel versions work. Please note that currently older Solaris kernels
2104 don't work probably due to interface issues between OpenBIOS and
2107 @c man begin OPTIONS
2109 The following options are specific to the Sparc32 emulation:
2113 @item -g @var{W}x@var{H}x[x@var{DEPTH}]
2115 Set the initial graphics mode. For TCX, the default is 1024x768x8 with the
2116 option of 1024x768x24. For cgthree, the default is 1024x768x8 with the option
2117 of 1152x900x8 for people who wish to use OBP.
2119 @item -prom-env @var{string}
2121 Set OpenBIOS variables in NVRAM, for example:
2124 qemu-system-sparc -prom-env 'auto-boot?=false' \
2125 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
2128 @item -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic] [|SPARCbook]
2130 Set the emulated machine type. Default is SS-5.
2136 @node Sparc64 System emulator
2137 @section Sparc64 System emulator
2138 @cindex system emulation (Sparc64)
2140 Use the executable @file{qemu-system-sparc64} to simulate a Sun4u
2141 (UltraSPARC PC-like machine), Sun4v (T1 PC-like machine), or generic
2142 Niagara (T1) machine. The Sun4u emulator is mostly complete, being
2143 able to run Linux, NetBSD and OpenBSD in headless (-nographic) mode. The
2144 Sun4v and Niagara emulators are still a work in progress.
2146 QEMU emulates the following peripherals:
2150 UltraSparc IIi APB PCI Bridge
2152 PCI VGA compatible card with VESA Bochs Extensions
2154 PS/2 mouse and keyboard
2156 Non Volatile RAM M48T59
2158 PC-compatible serial ports
2160 2 PCI IDE interfaces with hard disk and CD-ROM support
2165 @c man begin OPTIONS
2167 The following options are specific to the Sparc64 emulation:
2171 @item -prom-env @var{string}
2173 Set OpenBIOS variables in NVRAM, for example:
2176 qemu-system-sparc64 -prom-env 'auto-boot?=false'
2179 @item -M [sun4u|sun4v|Niagara]
2181 Set the emulated machine type. The default is sun4u.
2187 @node MIPS System emulator
2188 @section MIPS System emulator
2189 @cindex system emulation (MIPS)
2191 Four executables cover simulation of 32 and 64-bit MIPS systems in
2192 both endian options, @file{qemu-system-mips}, @file{qemu-system-mipsel}
2193 @file{qemu-system-mips64} and @file{qemu-system-mips64el}.
2194 Five different machine types are emulated:
2198 A generic ISA PC-like machine "mips"
2200 The MIPS Malta prototype board "malta"
2202 An ACER Pica "pica61". This machine needs the 64-bit emulator.
2204 MIPS emulator pseudo board "mipssim"
2206 A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator.
2209 The generic emulation is supported by Debian 'Etch' and is able to
2210 install Debian into a virtual disk image. The following devices are
2215 A range of MIPS CPUs, default is the 24Kf
2217 PC style serial port
2224 The Malta emulation supports the following devices:
2228 Core board with MIPS 24Kf CPU and Galileo system controller
2230 PIIX4 PCI/USB/SMbus controller
2232 The Multi-I/O chip's serial device
2234 PCI network cards (PCnet32 and others)
2236 Malta FPGA serial device
2238 Cirrus (default) or any other PCI VGA graphics card
2241 The ACER Pica emulation supports:
2247 PC-style IRQ and DMA controllers
2254 The mipssim pseudo board emulation provides an environment similar
2255 to what the proprietary MIPS emulator uses for running Linux.
2260 A range of MIPS CPUs, default is the 24Kf
2262 PC style serial port
2264 MIPSnet network emulation
2267 The MIPS Magnum R4000 emulation supports:
2273 PC-style IRQ controller
2283 @node ARM System emulator
2284 @section ARM System emulator
2285 @cindex system emulation (ARM)
2287 Use the executable @file{qemu-system-arm} to simulate a ARM
2288 machine. The ARM Integrator/CP board is emulated with the following
2293 ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU
2297 SMC 91c111 Ethernet adapter
2299 PL110 LCD controller
2301 PL050 KMI with PS/2 keyboard and mouse.
2303 PL181 MultiMedia Card Interface with SD card.
2306 The ARM Versatile baseboard is emulated with the following devices:
2310 ARM926E, ARM1136 or Cortex-A8 CPU
2312 PL190 Vectored Interrupt Controller
2316 SMC 91c111 Ethernet adapter
2318 PL110 LCD controller
2320 PL050 KMI with PS/2 keyboard and mouse.
2322 PCI host bridge. Note the emulated PCI bridge only provides access to
2323 PCI memory space. It does not provide access to PCI IO space.
2324 This means some devices (eg. ne2k_pci NIC) are not usable, and others
2325 (eg. rtl8139 NIC) are only usable when the guest drivers use the memory
2326 mapped control registers.
2328 PCI OHCI USB controller.
2330 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
2332 PL181 MultiMedia Card Interface with SD card.
2335 Several variants of the ARM RealView baseboard are emulated,
2336 including the EB, PB-A8 and PBX-A9. Due to interactions with the
2337 bootloader, only certain Linux kernel configurations work out
2338 of the box on these boards.
2340 Kernels for the PB-A8 board should have CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2341 enabled in the kernel, and expect 512M RAM. Kernels for The PBX-A9 board
2342 should have CONFIG_SPARSEMEM enabled, CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2343 disabled and expect 1024M RAM.
2345 The following devices are emulated:
2349 ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU
2351 ARM AMBA Generic/Distributed Interrupt Controller
2355 SMC 91c111 or SMSC LAN9118 Ethernet adapter
2357 PL110 LCD controller
2359 PL050 KMI with PS/2 keyboard and mouse
2363 PCI OHCI USB controller
2365 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
2367 PL181 MultiMedia Card Interface with SD card.
2370 The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
2371 and "Terrier") emulation includes the following peripherals:
2375 Intel PXA270 System-on-chip (ARM V5TE core)
2379 IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
2381 On-chip OHCI USB controller
2383 On-chip LCD controller
2385 On-chip Real Time Clock
2387 TI ADS7846 touchscreen controller on SSP bus
2389 Maxim MAX1111 analog-digital converter on I@math{^2}C bus
2391 GPIO-connected keyboard controller and LEDs
2393 Secure Digital card connected to PXA MMC/SD host
2397 WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
2400 The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the
2405 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2407 ROM and RAM memories (ROM firmware image can be loaded with -option-rom)
2409 On-chip LCD controller
2411 On-chip Real Time Clock
2413 TI TSC2102i touchscreen controller / analog-digital converter / Audio
2414 CODEC, connected through MicroWire and I@math{^2}S busses
2416 GPIO-connected matrix keypad
2418 Secure Digital card connected to OMAP MMC/SD host
2423 Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48)
2424 emulation supports the following elements:
2428 Texas Instruments OMAP2420 System-on-chip (ARM 1136 core)
2430 RAM and non-volatile OneNAND Flash memories
2432 Display connected to EPSON remote framebuffer chip and OMAP on-chip
2433 display controller and a LS041y3 MIPI DBI-C controller
2435 TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers
2436 driven through SPI bus
2438 National Semiconductor LM8323-controlled qwerty keyboard driven
2439 through I@math{^2}C bus
2441 Secure Digital card connected to OMAP MMC/SD host
2443 Three OMAP on-chip UARTs and on-chip STI debugging console
2445 A Bluetooth(R) transceiver and HCI connected to an UART
2447 Mentor Graphics "Inventra" dual-role USB controller embedded in a TI
2448 TUSB6010 chip - only USB host mode is supported
2450 TI TMP105 temperature sensor driven through I@math{^2}C bus
2452 TI TWL92230C power management companion with an RTC on I@math{^2}C bus
2454 Nokia RETU and TAHVO multi-purpose chips with an RTC, connected
2458 The Luminary Micro Stellaris LM3S811EVB emulation includes the following
2465 64k Flash and 8k SRAM.
2467 Timers, UARTs, ADC and I@math{^2}C interface.
2469 OSRAM Pictiva 96x16 OLED with SSD0303 controller on I@math{^2}C bus.
2472 The Luminary Micro Stellaris LM3S6965EVB emulation includes the following
2479 256k Flash and 64k SRAM.
2481 Timers, UARTs, ADC, I@math{^2}C and SSI interfaces.
2483 OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI.
2486 The Freecom MusicPal internet radio emulation includes the following
2491 Marvell MV88W8618 ARM core.
2493 32 MB RAM, 256 KB SRAM, 8 MB flash.
2497 MV88W8xx8 Ethernet controller
2499 MV88W8618 audio controller, WM8750 CODEC and mixer
2501 128×64 display with brightness control
2503 2 buttons, 2 navigation wheels with button function
2506 The Siemens SX1 models v1 and v2 (default) basic emulation.
2507 The emulation includes the following elements:
2511 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2513 ROM and RAM memories (ROM firmware image can be loaded with -pflash)
2515 1 Flash of 16MB and 1 Flash of 8MB
2519 On-chip LCD controller
2521 On-chip Real Time Clock
2523 Secure Digital card connected to OMAP MMC/SD host
2528 A Linux 2.6 test image is available on the QEMU web site. More
2529 information is available in the QEMU mailing-list archive.
2531 @c man begin OPTIONS
2533 The following options are specific to the ARM emulation:
2538 Enable semihosting syscall emulation.
2540 On ARM this implements the "Angel" interface.
2542 Note that this allows guest direct access to the host filesystem,
2543 so should only be used with trusted guest OS.
2547 @node ColdFire System emulator
2548 @section ColdFire System emulator
2549 @cindex system emulation (ColdFire)
2550 @cindex system emulation (M68K)
2552 Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2553 The emulator is able to boot a uClinux kernel.
2555 The M5208EVB emulation includes the following devices:
2559 MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2561 Three Two on-chip UARTs.
2563 Fast Ethernet Controller (FEC)
2566 The AN5206 emulation includes the following devices:
2570 MCF5206 ColdFire V2 Microprocessor.
2575 @c man begin OPTIONS
2577 The following options are specific to the ColdFire emulation:
2582 Enable semihosting syscall emulation.
2584 On M68K this implements the "ColdFire GDB" interface used by libgloss.
2586 Note that this allows guest direct access to the host filesystem,
2587 so should only be used with trusted guest OS.
2591 @node Cris System emulator
2592 @section Cris System emulator
2593 @cindex system emulation (Cris)
2597 @node Microblaze System emulator
2598 @section Microblaze System emulator
2599 @cindex system emulation (Microblaze)
2603 @node SH4 System emulator
2604 @section SH4 System emulator
2605 @cindex system emulation (SH4)
2609 @node Xtensa System emulator
2610 @section Xtensa System emulator
2611 @cindex system emulation (Xtensa)
2613 Two executables cover simulation of both Xtensa endian options,
2614 @file{qemu-system-xtensa} and @file{qemu-system-xtensaeb}.
2615 Two different machine types are emulated:
2619 Xtensa emulator pseudo board "sim"
2621 Avnet LX60/LX110/LX200 board
2624 The sim pseudo board emulation provides an environment similar
2625 to one provided by the proprietary Tensilica ISS.
2630 A range of Xtensa CPUs, default is the DC232B
2632 Console and filesystem access via semihosting calls
2635 The Avnet LX60/LX110/LX200 emulation supports:
2639 A range of Xtensa CPUs, default is the DC232B
2643 OpenCores 10/100 Mbps Ethernet MAC
2646 @c man begin OPTIONS
2648 The following options are specific to the Xtensa emulation:
2653 Enable semihosting syscall emulation.
2655 Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select.
2656 Tensilica baremetal libc for ISS and linux platform "sim" use this interface.
2658 Note that this allows guest direct access to the host filesystem,
2659 so should only be used with trusted guest OS.
2662 @node QEMU User space emulator
2663 @chapter QEMU User space emulator
2666 * Supported Operating Systems ::
2667 * Linux User space emulator::
2668 * BSD User space emulator ::
2671 @node Supported Operating Systems
2672 @section Supported Operating Systems
2674 The following OS are supported in user space emulation:
2678 Linux (referred as qemu-linux-user)
2680 BSD (referred as qemu-bsd-user)
2683 @node Linux User space emulator
2684 @section Linux User space emulator
2689 * Command line options::
2694 @subsection Quick Start
2696 In order to launch a Linux process, QEMU needs the process executable
2697 itself and all the target (x86) dynamic libraries used by it.
2701 @item On x86, you can just try to launch any process by using the native
2705 qemu-i386 -L / /bin/ls
2708 @code{-L /} tells that the x86 dynamic linker must be searched with a
2711 @item Since QEMU is also a linux process, you can launch QEMU with
2712 QEMU (NOTE: you can only do that if you compiled QEMU from the sources):
2715 qemu-i386 -L / qemu-i386 -L / /bin/ls
2718 @item On non x86 CPUs, you need first to download at least an x86 glibc
2719 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2720 @code{LD_LIBRARY_PATH} is not set:
2723 unset LD_LIBRARY_PATH
2726 Then you can launch the precompiled @file{ls} x86 executable:
2729 qemu-i386 tests/i386/ls
2731 You can look at @file{scripts/qemu-binfmt-conf.sh} so that
2732 QEMU is automatically launched by the Linux kernel when you try to
2733 launch x86 executables. It requires the @code{binfmt_misc} module in the
2736 @item The x86 version of QEMU is also included. You can try weird things such as:
2738 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2739 /usr/local/qemu-i386/bin/ls-i386
2745 @subsection Wine launch
2749 @item Ensure that you have a working QEMU with the x86 glibc
2750 distribution (see previous section). In order to verify it, you must be
2754 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2757 @item Download the binary x86 Wine install
2758 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2760 @item Configure Wine on your account. Look at the provided script
2761 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2762 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2764 @item Then you can try the example @file{putty.exe}:
2767 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2768 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2773 @node Command line options
2774 @subsection Command line options
2777 @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}...]
2784 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2786 Set the x86 stack size in bytes (default=524288)
2788 Select CPU model (-cpu help for list and additional feature selection)
2789 @item -E @var{var}=@var{value}
2790 Set environment @var{var} to @var{value}.
2792 Remove @var{var} from the environment.
2794 Offset guest address by the specified number of bytes. This is useful when
2795 the address region required by guest applications is reserved on the host.
2796 This option is currently only supported on some hosts.
2798 Pre-allocate a guest virtual address space of the given size (in bytes).
2799 "G", "M", and "k" suffixes may be used when specifying the size.
2806 Activate logging of the specified items (use '-d help' for a list of log items)
2808 Act as if the host page size was 'pagesize' bytes
2810 Wait gdb connection to port
2812 Run the emulation in single step mode.
2815 Environment variables:
2819 Print system calls and arguments similar to the 'strace' program
2820 (NOTE: the actual 'strace' program will not work because the user
2821 space emulator hasn't implemented ptrace). At the moment this is
2822 incomplete. All system calls that don't have a specific argument
2823 format are printed with information for six arguments. Many
2824 flag-style arguments don't have decoders and will show up as numbers.
2827 @node Other binaries
2828 @subsection Other binaries
2830 @cindex user mode (Alpha)
2831 @command{qemu-alpha} TODO.
2833 @cindex user mode (ARM)
2834 @command{qemu-armeb} TODO.
2836 @cindex user mode (ARM)
2837 @command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2838 binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2839 configurations), and arm-uclinux bFLT format binaries.
2841 @cindex user mode (ColdFire)
2842 @cindex user mode (M68K)
2843 @command{qemu-m68k} is capable of running semihosted binaries using the BDM
2844 (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2845 coldfire uClinux bFLT format binaries.
2847 The binary format is detected automatically.
2849 @cindex user mode (Cris)
2850 @command{qemu-cris} TODO.
2852 @cindex user mode (i386)
2853 @command{qemu-i386} TODO.
2854 @command{qemu-x86_64} TODO.
2856 @cindex user mode (Microblaze)
2857 @command{qemu-microblaze} TODO.
2859 @cindex user mode (MIPS)
2860 @command{qemu-mips} TODO.
2861 @command{qemu-mipsel} TODO.
2863 @cindex user mode (PowerPC)
2864 @command{qemu-ppc64abi32} TODO.
2865 @command{qemu-ppc64} TODO.
2866 @command{qemu-ppc} TODO.
2868 @cindex user mode (SH4)
2869 @command{qemu-sh4eb} TODO.
2870 @command{qemu-sh4} TODO.
2872 @cindex user mode (SPARC)
2873 @command{qemu-sparc} can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).
2875 @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2876 (Sparc64 CPU, 32 bit ABI).
2878 @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2879 SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2881 @node BSD User space emulator
2882 @section BSD User space emulator
2887 * BSD Command line options::
2891 @subsection BSD Status
2895 target Sparc64 on Sparc64: Some trivial programs work.
2898 @node BSD Quick Start
2899 @subsection Quick Start
2901 In order to launch a BSD process, QEMU needs the process executable
2902 itself and all the target dynamic libraries used by it.
2906 @item On Sparc64, you can just try to launch any process by using the native
2910 qemu-sparc64 /bin/ls
2915 @node BSD Command line options
2916 @subsection Command line options
2919 @command{qemu-sparc64} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-bsd} @var{type}] @var{program} [@var{arguments}...]
2926 Set the library root path (default=/)
2928 Set the stack size in bytes (default=524288)
2929 @item -ignore-environment
2930 Start with an empty environment. Without this option,
2931 the initial environment is a copy of the caller's environment.
2932 @item -E @var{var}=@var{value}
2933 Set environment @var{var} to @var{value}.
2935 Remove @var{var} from the environment.
2937 Set the type of the emulated BSD Operating system. Valid values are
2938 FreeBSD, NetBSD and OpenBSD (default).
2945 Activate logging of the specified items (use '-d help' for a list of log items)
2947 Act as if the host page size was 'pagesize' bytes
2949 Run the emulation in single step mode.
2953 @chapter Compilation from the sources
2958 * Cross compilation for Windows with Linux::
2966 @subsection Compilation
2968 First you must decompress the sources:
2971 tar zxvf qemu-x.y.z.tar.gz
2975 Then you configure QEMU and build it (usually no options are needed):
2981 Then type as root user:
2985 to install QEMU in @file{/usr/local}.
2991 @item Install the current versions of MSYS and MinGW from
2992 @url{http://www.mingw.org/}. You can find detailed installation
2993 instructions in the download section and the FAQ.
2996 the MinGW development library of SDL 1.2.x
2997 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
2998 @url{http://www.libsdl.org}. Unpack it in a temporary place and
2999 edit the @file{sdl-config} script so that it gives the
3000 correct SDL directory when invoked.
3002 @item Install the MinGW version of zlib and make sure
3003 @file{zlib.h} and @file{libz.dll.a} are in
3004 MinGW's default header and linker search paths.
3006 @item Extract the current version of QEMU.
3008 @item Start the MSYS shell (file @file{msys.bat}).
3010 @item Change to the QEMU directory. Launch @file{./configure} and
3011 @file{make}. If you have problems using SDL, verify that
3012 @file{sdl-config} can be launched from the MSYS command line.
3014 @item You can install QEMU in @file{Program Files/QEMU} by typing
3015 @file{make install}. Don't forget to copy @file{SDL.dll} in
3016 @file{Program Files/QEMU}.
3020 @node Cross compilation for Windows with Linux
3021 @section Cross compilation for Windows with Linux
3025 Install the MinGW cross compilation tools available at
3026 @url{http://www.mingw.org/}.
3029 the MinGW development library of SDL 1.2.x
3030 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
3031 @url{http://www.libsdl.org}. Unpack it in a temporary place and
3032 edit the @file{sdl-config} script so that it gives the
3033 correct SDL directory when invoked. Set up the @code{PATH} environment
3034 variable so that @file{sdl-config} can be launched by
3035 the QEMU configuration script.
3037 @item Install the MinGW version of zlib and make sure
3038 @file{zlib.h} and @file{libz.dll.a} are in
3039 MinGW's default header and linker search paths.
3042 Configure QEMU for Windows cross compilation:
3044 PATH=/usr/i686-pc-mingw32/sys-root/mingw/bin:$PATH ./configure --cross-prefix='i686-pc-mingw32-'
3046 The example assumes @file{sdl-config} is installed under @file{/usr/i686-pc-mingw32/sys-root/mingw/bin} and
3047 MinGW cross compilation tools have names like @file{i686-pc-mingw32-gcc} and @file{i686-pc-mingw32-strip}.
3048 We set the @code{PATH} environment variable to ensure the MinGW version of @file{sdl-config} is used and
3049 use --cross-prefix to specify the name of the cross compiler.
3050 You can also use --prefix to set the Win32 install path which defaults to @file{c:/Program Files/QEMU}.
3052 Under Fedora Linux, you can run:
3054 yum -y install mingw32-gcc mingw32-SDL mingw32-zlib
3056 to get a suitable cross compilation environment.
3058 @item You can install QEMU in the installation directory by typing
3059 @code{make install}. Don't forget to copy @file{SDL.dll} and @file{zlib1.dll} into the
3060 installation directory.
3064 Wine can be used to launch the resulting qemu-system-i386.exe
3065 and all other qemu-system-@var{target}.exe compiled for Win32.
3070 System Requirements:
3072 @item Mac OS 10.5 or higher
3073 @item The clang compiler shipped with Xcode 4.2 or higher,
3074 or GCC 4.3 or higher
3077 Additional Requirements (install in order):
3079 @item libffi: @uref{https://sourceware.org/libffi/}
3080 @item gettext: @uref{http://www.gnu.org/software/gettext/}
3081 @item glib: @uref{http://ftp.gnome.org/pub/GNOME/sources/glib/}
3082 @item pkg-config: @uref{http://www.freedesktop.org/wiki/Software/pkg-config/}
3083 @item autoconf: @uref{http://www.gnu.org/software/autoconf/autoconf.html}
3084 @item automake: @uref{http://www.gnu.org/software/automake/}
3085 @item pixman: @uref{http://www.pixman.org/}
3088 * You may find it easiest to get these from a third-party packager
3089 such as Homebrew, Macports, or Fink.
3091 After downloading the QEMU source code, double-click it to expand it.
3093 Then configure and make QEMU:
3099 If you have a recent version of Mac OS X (OSX 10.7 or better
3100 with Xcode 4.2 or better) we recommend building QEMU with the
3101 default compiler provided by Apple, for your version of Mac OS X
3102 (which will be 'clang'). The configure script will
3103 automatically pick this.
3105 Note: If after the configure step you see a message like this:
3107 ERROR: Your compiler does not support the __thread specifier for
3108 Thread-Local Storage (TLS). Please upgrade to a version that does.
3110 you may have to build your own version of gcc from source. Expect that to take
3111 several hours. More information can be found here:
3112 @uref{https://gcc.gnu.org/install/} @*
3114 These are some of the third party binaries of gcc available for download:
3116 @item Homebrew: @uref{http://brew.sh/}
3117 @item @uref{https://www.litebeam.net/gcc/gcc_472.pkg}
3118 @item @uref{http://www.macports.org/ports.php?by=name&substr=gcc}
3121 You can have several versions of GCC on your system. To specify a certain version,
3122 use the --cc and --cxx options.
3124 ./configure --cxx=<path of your c++ compiler> --cc=<path of your c compiler> <other options>
3128 @section Make targets
3134 Make everything which is typically needed.
3143 Remove most files which were built during make.
3145 @item make distclean
3146 Remove everything which was built during make.
3152 Create documentation in dvi, html, info or pdf format.
3157 @item make defconfig
3158 (Re-)create some build configuration files.
3159 User made changes will be overwritten.
3170 QEMU is a trademark of Fabrice Bellard.
3172 QEMU is released under the GNU General Public License (TODO: add link).
3173 Parts of QEMU have specific licenses, see file LICENSE.
3175 TODO (refer to file LICENSE, include it, include the GPL?)
3189 @section Concept Index
3190 This is the main index. Should we combine all keywords in one index? TODO
3193 @node Function Index
3194 @section Function Index
3195 This index could be used for command line options and monitor functions.
3198 @node Keystroke Index
3199 @section Keystroke Index
3201 This is a list of all keystrokes which have a special function
3202 in system emulation.
3207 @section Program Index
3210 @node Data Type Index
3211 @section Data Type Index
3213 This index could be used for qdev device names and options.
3217 @node Variable Index
3218 @section Variable Index