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 QEMU has two operating modes:
63 @cindex operating modes
66 @cindex system emulation
67 Full system emulation. In this mode, QEMU emulates a full system (for
68 example a PC), including one or several processors and various
69 peripherals. It can be used to launch different Operating Systems
70 without rebooting the PC or to debug system code.
73 @cindex user mode emulation
74 User mode emulation. In this mode, QEMU can launch
75 processes compiled for one CPU on another CPU. It can be used to
76 launch the Wine Windows API emulator (@url{http://www.winehq.org}) or
77 to ease cross-compilation and cross-debugging.
81 QEMU can run without a host kernel driver and yet gives acceptable
84 For system emulation, the following hardware targets are supported:
86 @cindex emulated target systems
87 @cindex supported target systems
88 @item PC (x86 or x86_64 processor)
89 @item ISA PC (old style PC without PCI bus)
90 @item PREP (PowerPC processor)
91 @item G3 Beige PowerMac (PowerPC processor)
92 @item Mac99 PowerMac (PowerPC processor, in progress)
93 @item Sun4m/Sun4c/Sun4d (32-bit Sparc processor)
94 @item Sun4u/Sun4v (64-bit Sparc processor, in progress)
95 @item Malta board (32-bit and 64-bit MIPS processors)
96 @item MIPS Magnum (64-bit MIPS processor)
97 @item ARM Integrator/CP (ARM)
98 @item ARM Versatile baseboard (ARM)
99 @item ARM RealView Emulation/Platform baseboard (ARM)
100 @item Spitz, Akita, Borzoi, Terrier and Tosa PDAs (PXA270 processor)
101 @item Luminary Micro LM3S811EVB (ARM Cortex-M3)
102 @item Luminary Micro LM3S6965EVB (ARM Cortex-M3)
103 @item Freescale MCF5208EVB (ColdFire V2).
104 @item Arnewsh MCF5206 evaluation board (ColdFire V2).
105 @item Palm Tungsten|E PDA (OMAP310 processor)
106 @item N800 and N810 tablets (OMAP2420 processor)
107 @item MusicPal (MV88W8618 ARM processor)
108 @item Gumstix "Connex" and "Verdex" motherboards (PXA255/270).
109 @item Siemens SX1 smartphone (OMAP310 processor)
110 @item AXIS-Devboard88 (CRISv32 ETRAX-FS).
111 @item Petalogix Spartan 3aDSP1800 MMU ref design (MicroBlaze).
112 @item Avnet LX60/LX110/LX200 boards (Xtensa)
115 @cindex supported user mode targets
116 For user emulation, x86 (32 and 64 bit), PowerPC (32 and 64 bit),
117 ARM, MIPS (32 bit only), Sparc (32 and 64 bit),
118 Alpha, ColdFire(m68k), CRISv32 and MicroBlaze CPUs are supported.
121 @chapter Installation
123 If you want to compile QEMU yourself, see @ref{compilation}.
126 * install_linux:: Linux
127 * install_windows:: Windows
128 * install_mac:: Macintosh
133 @cindex installation (Linux)
135 If a precompiled package is available for your distribution - you just
136 have to install it. Otherwise, see @ref{compilation}.
138 @node install_windows
140 @cindex installation (Windows)
142 Download the experimental binary installer at
143 @url{http://www.free.oszoo.org/@/download.html}.
144 TODO (no longer available)
149 Download the experimental binary installer at
150 @url{http://www.free.oszoo.org/@/download.html}.
151 TODO (no longer available)
153 @node QEMU PC System emulator
154 @chapter QEMU PC System emulator
155 @cindex system emulation (PC)
158 * pcsys_introduction:: Introduction
159 * pcsys_quickstart:: Quick Start
160 * sec_invocation:: Invocation
162 * pcsys_monitor:: QEMU Monitor
163 * disk_images:: Disk Images
164 * pcsys_network:: Network emulation
165 * pcsys_other_devs:: Other Devices
166 * direct_linux_boot:: Direct Linux Boot
167 * pcsys_usb:: USB emulation
168 * vnc_security:: VNC security
169 * gdb_usage:: GDB usage
170 * pcsys_os_specific:: Target OS specific information
173 @node pcsys_introduction
174 @section Introduction
176 @c man begin DESCRIPTION
178 The QEMU PC System emulator simulates the
179 following peripherals:
183 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
185 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
186 extensions (hardware level, including all non standard modes).
188 PS/2 mouse and keyboard
190 2 PCI IDE interfaces with hard disk and CD-ROM support
194 PCI and ISA network adapters
198 IPMI BMC, either and internal or external one
200 Creative SoundBlaster 16 sound card
202 ENSONIQ AudioPCI ES1370 sound card
204 Intel 82801AA AC97 Audio compatible sound card
206 Intel HD Audio Controller and HDA codec
208 Adlib (OPL2) - Yamaha YM3812 compatible chip
210 Gravis Ultrasound GF1 sound card
212 CS4231A compatible sound card
214 PCI UHCI USB controller and a virtual USB hub.
217 SMP is supported with up to 255 CPUs.
219 QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs LGPL
222 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
224 QEMU uses GUS emulation (GUSEMU32 @url{http://www.deinmeister.de/gusemu/})
225 by Tibor "TS" Schütz.
227 Note that, by default, GUS shares IRQ(7) with parallel ports and so
228 QEMU must be told to not have parallel ports to have working GUS.
231 qemu-system-i386 dos.img -soundhw gus -parallel none
236 qemu-system-i386 dos.img -device gus,irq=5
239 Or some other unclaimed IRQ.
241 CS4231A is the chip used in Windows Sound System and GUSMAX products
245 @node pcsys_quickstart
249 Download and uncompress the linux image (@file{linux.img}) and type:
252 qemu-system-i386 linux.img
255 Linux should boot and give you a prompt.
261 @c man begin SYNOPSIS
262 @command{qemu-system-i386} [@var{options}] [@var{disk_image}]
267 @var{disk_image} is a raw hard disk image for IDE hard disk 0. Some
268 targets do not need a disk image.
270 @include qemu-options.texi
279 During the graphical emulation, you can use special key combinations to change
280 modes. The default key mappings are shown below, but if you use @code{-alt-grab}
281 then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use
282 @code{-ctrl-grab} then the modifier is the right Ctrl key (instead of Ctrl-Alt):
299 Restore the screen's un-scaled dimensions
303 Switch to virtual console 'n'. Standard console mappings are:
306 Target system display
315 Toggle mouse and keyboard grab.
321 @kindex Ctrl-PageDown
322 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
323 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
326 During emulation, if you are using the @option{-nographic} option, use
327 @key{Ctrl-a h} to get terminal commands:
340 Save disk data back to file (if -snapshot)
343 Toggle console timestamps
346 Send break (magic sysrq in Linux)
349 Switch between console and monitor
359 The HTML documentation of QEMU for more precise information and Linux
360 user mode emulator invocation.
370 @section QEMU Monitor
373 The QEMU monitor is used to give complex commands to the QEMU
374 emulator. You can use it to:
379 Remove or insert removable media images
380 (such as CD-ROM or floppies).
383 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
386 @item Inspect the VM state without an external debugger.
392 The following commands are available:
394 @include qemu-monitor.texi
396 @include qemu-monitor-info.texi
398 @subsection Integer expressions
400 The monitor understands integers expressions for every integer
401 argument. You can use register names to get the value of specifics
402 CPU registers by prefixing them with @emph{$}.
407 Since version 0.6.1, QEMU supports many disk image formats, including
408 growable disk images (their size increase as non empty sectors are
409 written), compressed and encrypted disk images. Version 0.8.3 added
410 the new qcow2 disk image format which is essential to support VM
414 * disk_images_quickstart:: Quick start for disk image creation
415 * disk_images_snapshot_mode:: Snapshot mode
416 * vm_snapshots:: VM snapshots
417 * qemu_img_invocation:: qemu-img Invocation
418 * qemu_nbd_invocation:: qemu-nbd Invocation
419 * qemu_ga_invocation:: qemu-ga Invocation
420 * disk_images_formats:: Disk image file formats
421 * host_drives:: Using host drives
422 * disk_images_fat_images:: Virtual FAT disk images
423 * disk_images_nbd:: NBD access
424 * disk_images_sheepdog:: Sheepdog disk images
425 * disk_images_iscsi:: iSCSI LUNs
426 * disk_images_gluster:: GlusterFS disk images
427 * disk_images_ssh:: Secure Shell (ssh) disk images
430 @node disk_images_quickstart
431 @subsection Quick start for disk image creation
433 You can create a disk image with the command:
435 qemu-img create myimage.img mysize
437 where @var{myimage.img} is the disk image filename and @var{mysize} is its
438 size in kilobytes. You can add an @code{M} suffix to give the size in
439 megabytes and a @code{G} suffix for gigabytes.
441 See @ref{qemu_img_invocation} for more information.
443 @node disk_images_snapshot_mode
444 @subsection Snapshot mode
446 If you use the option @option{-snapshot}, all disk images are
447 considered as read only. When sectors in written, they are written in
448 a temporary file created in @file{/tmp}. You can however force the
449 write back to the raw disk images by using the @code{commit} monitor
450 command (or @key{C-a s} in the serial console).
453 @subsection VM snapshots
455 VM snapshots are snapshots of the complete virtual machine including
456 CPU state, RAM, device state and the content of all the writable
457 disks. In order to use VM snapshots, you must have at least one non
458 removable and writable block device using the @code{qcow2} disk image
459 format. Normally this device is the first virtual hard drive.
461 Use the monitor command @code{savevm} to create a new VM snapshot or
462 replace an existing one. A human readable name can be assigned to each
463 snapshot in addition to its numerical ID.
465 Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
466 a VM snapshot. @code{info snapshots} lists the available snapshots
467 with their associated information:
470 (qemu) info snapshots
471 Snapshot devices: hda
472 Snapshot list (from hda):
473 ID TAG VM SIZE DATE VM CLOCK
474 1 start 41M 2006-08-06 12:38:02 00:00:14.954
475 2 40M 2006-08-06 12:43:29 00:00:18.633
476 3 msys 40M 2006-08-06 12:44:04 00:00:23.514
479 A VM snapshot is made of a VM state info (its size is shown in
480 @code{info snapshots}) and a snapshot of every writable disk image.
481 The VM state info is stored in the first @code{qcow2} non removable
482 and writable block device. The disk image snapshots are stored in
483 every disk image. The size of a snapshot in a disk image is difficult
484 to evaluate and is not shown by @code{info snapshots} because the
485 associated disk sectors are shared among all the snapshots to save
486 disk space (otherwise each snapshot would need a full copy of all the
489 When using the (unrelated) @code{-snapshot} option
490 (@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
491 but they are deleted as soon as you exit QEMU.
493 VM snapshots currently have the following known limitations:
496 They cannot cope with removable devices if they are removed or
497 inserted after a snapshot is done.
499 A few device drivers still have incomplete snapshot support so their
500 state is not saved or restored properly (in particular USB).
503 @node qemu_img_invocation
504 @subsection @code{qemu-img} Invocation
506 @include qemu-img.texi
508 @node qemu_nbd_invocation
509 @subsection @code{qemu-nbd} Invocation
511 @include qemu-nbd.texi
513 @node qemu_ga_invocation
514 @subsection @code{qemu-ga} Invocation
516 @include qemu-ga.texi
518 @node disk_images_formats
519 @subsection Disk image file formats
521 QEMU supports many image file formats that can be used with VMs as well as with
522 any of the tools (like @code{qemu-img}). This includes the preferred formats
523 raw and qcow2 as well as formats that are supported for compatibility with
524 older QEMU versions or other hypervisors.
526 Depending on the image format, different options can be passed to
527 @code{qemu-img create} and @code{qemu-img convert} using the @code{-o} option.
528 This section describes each format and the options that are supported for it.
533 Raw disk image format. This format has the advantage of
534 being simple and easily exportable to all other emulators. If your
535 file system supports @emph{holes} (for example in ext2 or ext3 on
536 Linux or NTFS on Windows), then only the written sectors will reserve
537 space. Use @code{qemu-img info} to know the real size used by the
538 image or @code{ls -ls} on Unix/Linux.
543 Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}).
544 @code{falloc} mode preallocates space for image by calling posix_fallocate().
545 @code{full} mode preallocates space for image by writing zeros to underlying
550 QEMU image format, the most versatile format. Use it to have smaller
551 images (useful if your filesystem does not supports holes, for example
552 on Windows), zlib based compression and support of multiple VM
558 Determines the qcow2 version to use. @code{compat=0.10} uses the
559 traditional image format that can be read by any QEMU since 0.10.
560 @code{compat=1.1} enables image format extensions that only QEMU 1.1 and
561 newer understand (this is the default). Amongst others, this includes
562 zero clusters, which allow efficient copy-on-read for sparse images.
565 File name of a base image (see @option{create} subcommand)
567 Image format of the base image
569 If this option is set to @code{on}, the image is encrypted with 128-bit AES-CBC.
571 The use of encryption in qcow and qcow2 images is considered to be flawed by
572 modern cryptography standards, suffering from a number of design problems:
575 @item The AES-CBC cipher is used with predictable initialization vectors based
576 on the sector number. This makes it vulnerable to chosen plaintext attacks
577 which can reveal the existence of encrypted data.
578 @item The user passphrase is directly used as the encryption key. A poorly
579 chosen or short passphrase will compromise the security of the encryption.
580 @item In the event of the passphrase being compromised there is no way to
581 change the passphrase to protect data in any qcow images. The files must
582 be cloned, using a different encryption passphrase in the new file. The
583 original file must then be securely erased using a program like shred,
584 though even this is ineffective with many modern storage technologies.
587 Use of qcow / qcow2 encryption with QEMU is deprecated, and support for
588 it will go away in a future release. Users are recommended to use an
589 alternative encryption technology such as the Linux dm-crypt / LUKS
593 Changes the qcow2 cluster size (must be between 512 and 2M). Smaller cluster
594 sizes can improve the image file size whereas larger cluster sizes generally
595 provide better performance.
598 Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
599 @code{full}). An image with preallocated metadata is initially larger but can
600 improve performance when the image needs to grow. @code{falloc} and @code{full}
601 preallocations are like the same options of @code{raw} format, but sets up
605 If this option is set to @code{on}, reference count updates are postponed with
606 the goal of avoiding metadata I/O and improving performance. This is
607 particularly interesting with @option{cache=writethrough} which doesn't batch
608 metadata updates. The tradeoff is that after a host crash, the reference count
609 tables must be rebuilt, i.e. on the next open an (automatic) @code{qemu-img
610 check -r all} is required, which may take some time.
612 This option can only be enabled if @code{compat=1.1} is specified.
615 If this option is set to @code{on}, it will turn off COW of the file. It's only
616 valid on btrfs, no effect on other file systems.
618 Btrfs has low performance when hosting a VM image file, even more when the guest
619 on the VM also using btrfs as file system. Turning off COW is a way to mitigate
620 this bad performance. Generally there are two ways to turn off COW on btrfs:
621 a) Disable it by mounting with nodatacow, then all newly created files will be
622 NOCOW. b) For an empty file, add the NOCOW file attribute. That's what this option
625 Note: this option is only valid to new or empty files. If there is an existing
626 file which is COW and has data blocks already, it couldn't be changed to NOCOW
627 by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if
628 the NOCOW flag is set or not (Capital 'C' is NOCOW flag).
633 Old QEMU image format with support for backing files and compact image files
634 (when your filesystem or transport medium does not support holes).
636 When converting QED images to qcow2, you might want to consider using the
637 @code{lazy_refcounts=on} option to get a more QED-like behaviour.
642 File name of a base image (see @option{create} subcommand).
644 Image file format of backing file (optional). Useful if the format cannot be
645 autodetected because it has no header, like some vhd/vpc files.
647 Changes the cluster size (must be power-of-2 between 4K and 64K). Smaller
648 cluster sizes can improve the image file size whereas larger cluster sizes
649 generally provide better performance.
651 Changes the number of clusters per L1/L2 table (must be power-of-2 between 1
652 and 16). There is normally no need to change this value but this option can be
653 used for performance benchmarking.
657 Old QEMU image format with support for backing files, compact image files,
658 encryption and compression.
663 File name of a base image (see @option{create} subcommand)
665 If this option is set to @code{on}, the image is encrypted.
669 VirtualBox 1.1 compatible image format.
673 If this option is set to @code{on}, the image is created with metadata
678 VMware 3 and 4 compatible image format.
683 File name of a base image (see @option{create} subcommand).
685 Create a VMDK version 6 image (instead of version 4)
687 Specifies which VMDK subformat to use. Valid options are
688 @code{monolithicSparse} (default),
689 @code{monolithicFlat},
690 @code{twoGbMaxExtentSparse},
691 @code{twoGbMaxExtentFlat} and
692 @code{streamOptimized}.
696 VirtualPC compatible image format (VHD).
700 Specifies which VHD subformat to use. Valid options are
701 @code{dynamic} (default) and @code{fixed}.
705 Hyper-V compatible image format (VHDX).
709 Specifies which VHDX subformat to use. Valid options are
710 @code{dynamic} (default) and @code{fixed}.
711 @item block_state_zero
712 Force use of payload blocks of type 'ZERO'. Can be set to @code{on} (default)
713 or @code{off}. When set to @code{off}, new blocks will be created as
714 @code{PAYLOAD_BLOCK_NOT_PRESENT}, which means parsers are free to return
715 arbitrary data for those blocks. Do not set to @code{off} when using
716 @code{qemu-img convert} with @code{subformat=dynamic}.
718 Block size; min 1 MB, max 256 MB. 0 means auto-calculate based on image size.
724 @subsubsection Read-only formats
725 More disk image file formats are supported in a read-only mode.
728 Bochs images of @code{growing} type.
730 Linux Compressed Loop image, useful only to reuse directly compressed
731 CD-ROM images present for example in the Knoppix CD-ROMs.
735 Parallels disk image format.
740 @subsection Using host drives
742 In addition to disk image files, QEMU can directly access host
743 devices. We describe here the usage for QEMU version >= 0.8.3.
747 On Linux, you can directly use the host device filename instead of a
748 disk image filename provided you have enough privileges to access
749 it. For example, use @file{/dev/cdrom} to access to the CDROM.
753 You can specify a CDROM device even if no CDROM is loaded. QEMU has
754 specific code to detect CDROM insertion or removal. CDROM ejection by
755 the guest OS is supported. Currently only data CDs are supported.
757 You can specify a floppy device even if no floppy is loaded. Floppy
758 removal is currently not detected accurately (if you change floppy
759 without doing floppy access while the floppy is not loaded, the guest
760 OS will think that the same floppy is loaded).
761 Use of the host's floppy device is deprecated, and support for it will
762 be removed in a future release.
764 Hard disks can be used. Normally you must specify the whole disk
765 (@file{/dev/hdb} instead of @file{/dev/hdb1}) so that the guest OS can
766 see it as a partitioned disk. WARNING: unless you know what you do, it
767 is better to only make READ-ONLY accesses to the hard disk otherwise
768 you may corrupt your host data (use the @option{-snapshot} command
769 line option or modify the device permissions accordingly).
772 @subsubsection Windows
776 The preferred syntax is the drive letter (e.g. @file{d:}). The
777 alternate syntax @file{\\.\d:} is supported. @file{/dev/cdrom} is
778 supported as an alias to the first CDROM drive.
780 Currently there is no specific code to handle removable media, so it
781 is better to use the @code{change} or @code{eject} monitor commands to
782 change or eject media.
784 Hard disks can be used with the syntax: @file{\\.\PhysicalDrive@var{N}}
785 where @var{N} is the drive number (0 is the first hard disk).
787 WARNING: unless you know what you do, it is better to only make
788 READ-ONLY accesses to the hard disk otherwise you may corrupt your
789 host data (use the @option{-snapshot} command line so that the
790 modifications are written in a temporary file).
794 @subsubsection Mac OS X
796 @file{/dev/cdrom} is an alias to the first CDROM.
798 Currently there is no specific code to handle removable media, so it
799 is better to use the @code{change} or @code{eject} monitor commands to
800 change or eject media.
802 @node disk_images_fat_images
803 @subsection Virtual FAT disk images
805 QEMU can automatically create a virtual FAT disk image from a
806 directory tree. In order to use it, just type:
809 qemu-system-i386 linux.img -hdb fat:/my_directory
812 Then you access access to all the files in the @file{/my_directory}
813 directory without having to copy them in a disk image or to export
814 them via SAMBA or NFS. The default access is @emph{read-only}.
816 Floppies can be emulated with the @code{:floppy:} option:
819 qemu-system-i386 linux.img -fda fat:floppy:/my_directory
822 A read/write support is available for testing (beta stage) with the
826 qemu-system-i386 linux.img -fda fat:floppy:rw:/my_directory
829 What you should @emph{never} do:
831 @item use non-ASCII filenames ;
832 @item use "-snapshot" together with ":rw:" ;
833 @item expect it to work when loadvm'ing ;
834 @item write to the FAT directory on the host system while accessing it with the guest system.
837 @node disk_images_nbd
838 @subsection NBD access
840 QEMU can access directly to block device exported using the Network Block Device
844 qemu-system-i386 linux.img -hdb nbd://my_nbd_server.mydomain.org:1024/
847 If the NBD server is located on the same host, you can use an unix socket instead
851 qemu-system-i386 linux.img -hdb nbd+unix://?socket=/tmp/my_socket
854 In this case, the block device must be exported using qemu-nbd:
857 qemu-nbd --socket=/tmp/my_socket my_disk.qcow2
860 The use of qemu-nbd allows sharing of a disk between several guests:
862 qemu-nbd --socket=/tmp/my_socket --share=2 my_disk.qcow2
866 and then you can use it with two guests:
868 qemu-system-i386 linux1.img -hdb nbd+unix://?socket=/tmp/my_socket
869 qemu-system-i386 linux2.img -hdb nbd+unix://?socket=/tmp/my_socket
872 If the nbd-server uses named exports (supported since NBD 2.9.18, or with QEMU's
873 own embedded NBD server), you must specify an export name in the URI:
875 qemu-system-i386 -cdrom nbd://localhost/debian-500-ppc-netinst
876 qemu-system-i386 -cdrom nbd://localhost/openSUSE-11.1-ppc-netinst
879 The URI syntax for NBD is supported since QEMU 1.3. An alternative syntax is
880 also available. Here are some example of the older syntax:
882 qemu-system-i386 linux.img -hdb nbd:my_nbd_server.mydomain.org:1024
883 qemu-system-i386 linux2.img -hdb nbd:unix:/tmp/my_socket
884 qemu-system-i386 -cdrom nbd:localhost:10809:exportname=debian-500-ppc-netinst
887 @node disk_images_sheepdog
888 @subsection Sheepdog disk images
890 Sheepdog is a distributed storage system for QEMU. It provides highly
891 available block level storage volumes that can be attached to
892 QEMU-based virtual machines.
894 You can create a Sheepdog disk image with the command:
896 qemu-img create sheepdog:///@var{image} @var{size}
898 where @var{image} is the Sheepdog image name and @var{size} is its
901 To import the existing @var{filename} to Sheepdog, you can use a
904 qemu-img convert @var{filename} sheepdog:///@var{image}
907 You can boot from the Sheepdog disk image with the command:
909 qemu-system-i386 sheepdog:///@var{image}
912 You can also create a snapshot of the Sheepdog image like qcow2.
914 qemu-img snapshot -c @var{tag} sheepdog:///@var{image}
916 where @var{tag} is a tag name of the newly created snapshot.
918 To boot from the Sheepdog snapshot, specify the tag name of the
921 qemu-system-i386 sheepdog:///@var{image}#@var{tag}
924 You can create a cloned image from the existing snapshot.
926 qemu-img create -b sheepdog:///@var{base}#@var{tag} sheepdog:///@var{image}
928 where @var{base} is a image name of the source snapshot and @var{tag}
931 You can use an unix socket instead of an inet socket:
934 qemu-system-i386 sheepdog+unix:///@var{image}?socket=@var{path}
937 If the Sheepdog daemon doesn't run on the local host, you need to
938 specify one of the Sheepdog servers to connect to.
940 qemu-img create sheepdog://@var{hostname}:@var{port}/@var{image} @var{size}
941 qemu-system-i386 sheepdog://@var{hostname}:@var{port}/@var{image}
944 @node disk_images_iscsi
945 @subsection iSCSI LUNs
947 iSCSI is a popular protocol used to access SCSI devices across a computer
950 There are two different ways iSCSI devices can be used by QEMU.
952 The first method is to mount the iSCSI LUN on the host, and make it appear as
953 any other ordinary SCSI device on the host and then to access this device as a
954 /dev/sd device from QEMU. How to do this differs between host OSes.
956 The second method involves using the iSCSI initiator that is built into
957 QEMU. This provides a mechanism that works the same way regardless of which
958 host OS you are running QEMU on. This section will describe this second method
959 of using iSCSI together with QEMU.
961 In QEMU, iSCSI devices are described using special iSCSI URLs
965 iscsi://[<username>[%<password>]@@]<host>[:<port>]/<target-iqn-name>/<lun>
968 Username and password are optional and only used if your target is set up
969 using CHAP authentication for access control.
970 Alternatively the username and password can also be set via environment
971 variables to have these not show up in the process list
974 export LIBISCSI_CHAP_USERNAME=<username>
975 export LIBISCSI_CHAP_PASSWORD=<password>
976 iscsi://<host>/<target-iqn-name>/<lun>
979 Various session related parameters can be set via special options, either
980 in a configuration file provided via '-readconfig' or directly on the
983 If the initiator-name is not specified qemu will use a default name
984 of 'iqn.2008-11.org.linux-kvm[:<name>'] where <name> is the name of the
989 Setting a specific initiator name to use when logging in to the target
990 -iscsi initiator-name=iqn.qemu.test:my-initiator
994 Controlling which type of header digest to negotiate with the target
995 -iscsi header-digest=CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
998 These can also be set via a configuration file
1001 user = "CHAP username"
1002 password = "CHAP password"
1003 initiator-name = "iqn.qemu.test:my-initiator"
1004 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1005 header-digest = "CRC32C"
1009 Setting the target name allows different options for different targets
1011 [iscsi "iqn.target.name"]
1012 user = "CHAP username"
1013 password = "CHAP password"
1014 initiator-name = "iqn.qemu.test:my-initiator"
1015 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1016 header-digest = "CRC32C"
1020 Howto use a configuration file to set iSCSI configuration options:
1022 cat >iscsi.conf <<EOF
1025 password = "my password"
1026 initiator-name = "iqn.qemu.test:my-initiator"
1027 header-digest = "CRC32C"
1030 qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1031 -readconfig iscsi.conf
1035 Howto set up a simple iSCSI target on loopback and accessing it via QEMU:
1037 This example shows how to set up an iSCSI target with one CDROM and one DISK
1038 using the Linux STGT software target. This target is available on Red Hat based
1039 systems as the package 'scsi-target-utils'.
1041 tgtd --iscsi portal=127.0.0.1:3260
1042 tgtadm --lld iscsi --op new --mode target --tid 1 -T iqn.qemu.test
1043 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 \
1044 -b /IMAGES/disk.img --device-type=disk
1045 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 \
1046 -b /IMAGES/cd.iso --device-type=cd
1047 tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL
1049 qemu-system-i386 -iscsi initiator-name=iqn.qemu.test:my-initiator \
1050 -boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1051 -cdrom iscsi://127.0.0.1/iqn.qemu.test/2
1054 @node disk_images_gluster
1055 @subsection GlusterFS disk images
1057 GlusterFS is an user space distributed file system.
1059 You can boot from the GlusterFS disk image with the command:
1061 qemu-system-x86_64 -drive file=gluster[+@var{transport}]://[@var{server}[:@var{port}]]/@var{volname}/@var{image}[?socket=...]
1064 @var{gluster} is the protocol.
1066 @var{transport} specifies the transport type used to connect to gluster
1067 management daemon (glusterd). Valid transport types are
1068 tcp, unix and rdma. If a transport type isn't specified, then tcp
1071 @var{server} specifies the server where the volume file specification for
1072 the given volume resides. This can be either hostname, ipv4 address
1073 or ipv6 address. ipv6 address needs to be within square brackets [ ].
1074 If transport type is unix, then @var{server} field should not be specified.
1075 Instead @var{socket} field needs to be populated with the path to unix domain
1078 @var{port} is the port number on which glusterd is listening. This is optional
1079 and if not specified, QEMU will send 0 which will make gluster to use the
1080 default port. If the transport type is unix, then @var{port} should not be
1083 @var{volname} is the name of the gluster volume which contains the disk image.
1085 @var{image} is the path to the actual disk image that resides on gluster volume.
1087 You can create a GlusterFS disk image with the command:
1089 qemu-img create gluster://@var{server}/@var{volname}/@var{image} @var{size}
1094 qemu-system-x86_64 -drive file=gluster://1.2.3.4/testvol/a.img
1095 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4/testvol/a.img
1096 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img
1097 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
1098 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img
1099 qemu-system-x86_64 -drive file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img
1100 qemu-system-x86_64 -drive file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
1101 qemu-system-x86_64 -drive file=gluster+rdma://1.2.3.4:24007/testvol/a.img
1104 @node disk_images_ssh
1105 @subsection Secure Shell (ssh) disk images
1107 You can access disk images located on a remote ssh server
1108 by using the ssh protocol:
1111 qemu-system-x86_64 -drive file=ssh://[@var{user}@@]@var{server}[:@var{port}]/@var{path}[?host_key_check=@var{host_key_check}]
1114 Alternative syntax using properties:
1117 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}]
1120 @var{ssh} is the protocol.
1122 @var{user} is the remote user. If not specified, then the local
1125 @var{server} specifies the remote ssh server. Any ssh server can be
1126 used, but it must implement the sftp-server protocol. Most Unix/Linux
1127 systems should work without requiring any extra configuration.
1129 @var{port} is the port number on which sshd is listening. By default
1130 the standard ssh port (22) is used.
1132 @var{path} is the path to the disk image.
1134 The optional @var{host_key_check} parameter controls how the remote
1135 host's key is checked. The default is @code{yes} which means to use
1136 the local @file{.ssh/known_hosts} file. Setting this to @code{no}
1137 turns off known-hosts checking. Or you can check that the host key
1138 matches a specific fingerprint:
1139 @code{host_key_check=md5:78:45:8e:14:57:4f:d5:45:83:0a:0e:f3:49:82:c9:c8}
1140 (@code{sha1:} can also be used as a prefix, but note that OpenSSH
1141 tools only use MD5 to print fingerprints).
1143 Currently authentication must be done using ssh-agent. Other
1144 authentication methods may be supported in future.
1146 Note: Many ssh servers do not support an @code{fsync}-style operation.
1147 The ssh driver cannot guarantee that disk flush requests are
1148 obeyed, and this causes a risk of disk corruption if the remote
1149 server or network goes down during writes. The driver will
1150 print a warning when @code{fsync} is not supported:
1152 warning: ssh server @code{ssh.example.com:22} does not support fsync
1154 With sufficiently new versions of libssh2 and OpenSSH, @code{fsync} is
1158 @section Network emulation
1160 QEMU can simulate several network cards (PCI or ISA cards on the PC
1161 target) and can connect them to an arbitrary number of Virtual Local
1162 Area Networks (VLANs). Host TAP devices can be connected to any QEMU
1163 VLAN. VLAN can be connected between separate instances of QEMU to
1164 simulate large networks. For simpler usage, a non privileged user mode
1165 network stack can replace the TAP device to have a basic network
1170 QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
1171 connection between several network devices. These devices can be for
1172 example QEMU virtual Ethernet cards or virtual Host ethernet devices
1175 @subsection Using TAP network interfaces
1177 This is the standard way to connect QEMU to a real network. QEMU adds
1178 a virtual network device on your host (called @code{tapN}), and you
1179 can then configure it as if it was a real ethernet card.
1181 @subsubsection Linux host
1183 As an example, you can download the @file{linux-test-xxx.tar.gz}
1184 archive and copy the script @file{qemu-ifup} in @file{/etc} and
1185 configure properly @code{sudo} so that the command @code{ifconfig}
1186 contained in @file{qemu-ifup} can be executed as root. You must verify
1187 that your host kernel supports the TAP network interfaces: the
1188 device @file{/dev/net/tun} must be present.
1190 See @ref{sec_invocation} to have examples of command lines using the
1191 TAP network interfaces.
1193 @subsubsection Windows host
1195 There is a virtual ethernet driver for Windows 2000/XP systems, called
1196 TAP-Win32. But it is not included in standard QEMU for Windows,
1197 so you will need to get it separately. It is part of OpenVPN package,
1198 so download OpenVPN from : @url{http://openvpn.net/}.
1200 @subsection Using the user mode network stack
1202 By using the option @option{-net user} (default configuration if no
1203 @option{-net} option is specified), QEMU uses a completely user mode
1204 network stack (you don't need root privilege to use the virtual
1205 network). The virtual network configuration is the following:
1209 QEMU VLAN <------> Firewall/DHCP server <-----> Internet
1212 ----> DNS server (10.0.2.3)
1214 ----> SMB server (10.0.2.4)
1217 The QEMU VM behaves as if it was behind a firewall which blocks all
1218 incoming connections. You can use a DHCP client to automatically
1219 configure the network in the QEMU VM. The DHCP server assign addresses
1220 to the hosts starting from 10.0.2.15.
1222 In order to check that the user mode network is working, you can ping
1223 the address 10.0.2.2 and verify that you got an address in the range
1224 10.0.2.x from the QEMU virtual DHCP server.
1226 Note that ICMP traffic in general does not work with user mode networking.
1227 @code{ping}, aka. ICMP echo, to the local router (10.0.2.2) shall work,
1228 however. If you're using QEMU on Linux >= 3.0, it can use unprivileged ICMP
1229 ping sockets to allow @code{ping} to the Internet. The host admin has to set
1230 the ping_group_range in order to grant access to those sockets. To allow ping
1231 for GID 100 (usually users group):
1234 echo 100 100 > /proc/sys/net/ipv4/ping_group_range
1237 When using the built-in TFTP server, the router is also the TFTP
1240 When using the @option{-redir} option, TCP or UDP connections can be
1241 redirected from the host to the guest. It allows for example to
1242 redirect X11, telnet or SSH connections.
1244 @subsection Connecting VLANs between QEMU instances
1246 Using the @option{-net socket} option, it is possible to make VLANs
1247 that span several QEMU instances. See @ref{sec_invocation} to have a
1250 @node pcsys_other_devs
1251 @section Other Devices
1253 @subsection Inter-VM Shared Memory device
1255 With KVM enabled on a Linux host, a shared memory device is available. Guests
1256 map a POSIX shared memory region into the guest as a PCI device that enables
1257 zero-copy communication to the application level of the guests. The basic
1261 qemu-system-i386 -device ivshmem,size=@var{size},shm=@var{shm-name}
1264 If desired, interrupts can be sent between guest VMs accessing the same shared
1265 memory region. Interrupt support requires using a shared memory server and
1266 using a chardev socket to connect to it. The code for the shared memory server
1267 is qemu.git/contrib/ivshmem-server. An example syntax when using the shared
1271 # First start the ivshmem server once and for all
1272 ivshmem-server -p @var{pidfile} -S @var{path} -m @var{shm-name} -l @var{shm-size} -n @var{vectors}
1274 # Then start your qemu instances with matching arguments
1275 qemu-system-i386 -device ivshmem,size=@var{shm-size},vectors=@var{vectors},chardev=@var{id}
1276 [,msi=on][,ioeventfd=on][,role=peer|master]
1277 -chardev socket,path=@var{path},id=@var{id}
1280 When using the server, the guest will be assigned a VM ID (>=0) that allows guests
1281 using the same server to communicate via interrupts. Guests can read their
1282 VM ID from a device register (see example code). Since receiving the shared
1283 memory region from the server is asynchronous, there is a (small) chance the
1284 guest may boot before the shared memory is attached. To allow an application
1285 to ensure shared memory is attached, the VM ID register will return -1 (an
1286 invalid VM ID) until the memory is attached. Once the shared memory is
1287 attached, the VM ID will return the guest's valid VM ID. With these semantics,
1288 the guest application can check to ensure the shared memory is attached to the
1289 guest before proceeding.
1291 The @option{role} argument can be set to either master or peer and will affect
1292 how the shared memory is migrated. With @option{role=master}, the guest will
1293 copy the shared memory on migration to the destination host. With
1294 @option{role=peer}, the guest will not be able to migrate with the device attached.
1295 With the @option{peer} case, the device should be detached and then reattached
1296 after migration using the PCI hotplug support.
1298 @subsubsection ivshmem and hugepages
1300 Instead of specifying the <shm size> using POSIX shm, you may specify
1301 a memory backend that has hugepage support:
1304 qemu-system-i386 -object memory-backend-file,size=1G,mem-path=/mnt/hugepages/my-shmem-file,id=mb1
1305 -device ivshmem,x-memdev=mb1
1308 ivshmem-server also supports hugepages mount points with the
1309 @option{-m} memory path argument.
1311 @node direct_linux_boot
1312 @section Direct Linux Boot
1314 This section explains how to launch a Linux kernel inside QEMU without
1315 having to make a full bootable image. It is very useful for fast Linux
1320 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
1323 Use @option{-kernel} to provide the Linux kernel image and
1324 @option{-append} to give the kernel command line arguments. The
1325 @option{-initrd} option can be used to provide an INITRD image.
1327 When using the direct Linux boot, a disk image for the first hard disk
1328 @file{hda} is required because its boot sector is used to launch the
1331 If you do not need graphical output, you can disable it and redirect
1332 the virtual serial port and the QEMU monitor to the console with the
1333 @option{-nographic} option. The typical command line is:
1335 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1336 -append "root=/dev/hda console=ttyS0" -nographic
1339 Use @key{Ctrl-a c} to switch between the serial console and the
1340 monitor (@pxref{pcsys_keys}).
1343 @section USB emulation
1345 QEMU emulates a PCI UHCI USB controller. You can virtually plug
1346 virtual USB devices or real host USB devices (experimental, works only
1347 on Linux hosts). QEMU will automatically create and connect virtual USB hubs
1348 as necessary to connect multiple USB devices.
1352 * host_usb_devices::
1355 @subsection Connecting USB devices
1357 USB devices can be connected with the @option{-usbdevice} commandline option
1358 or the @code{usb_add} monitor command. Available devices are:
1362 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1364 Pointer device that uses absolute coordinates (like a touchscreen).
1365 This means QEMU is able to report the mouse position without having
1366 to grab the mouse. Also overrides the PS/2 mouse emulation when activated.
1367 @item disk:@var{file}
1368 Mass storage device based on @var{file} (@pxref{disk_images})
1369 @item host:@var{bus.addr}
1370 Pass through the host device identified by @var{bus.addr}
1372 @item host:@var{vendor_id:product_id}
1373 Pass through the host device identified by @var{vendor_id:product_id}
1376 Virtual Wacom PenPartner tablet. This device is similar to the @code{tablet}
1377 above but it can be used with the tslib library because in addition to touch
1378 coordinates it reports touch pressure.
1380 Standard USB keyboard. Will override the PS/2 keyboard (if present).
1381 @item serial:[vendorid=@var{vendor_id}][,product_id=@var{product_id}]:@var{dev}
1382 Serial converter. This emulates an FTDI FT232BM chip connected to host character
1383 device @var{dev}. The available character devices are the same as for the
1384 @code{-serial} option. The @code{vendorid} and @code{productid} options can be
1385 used to override the default 0403:6001. For instance,
1387 usb_add serial:productid=FA00:tcp:192.168.0.2:4444
1389 will connect to tcp port 4444 of ip 192.168.0.2, and plug that to the virtual
1390 serial converter, faking a Matrix Orbital LCD Display (USB ID 0403:FA00).
1392 Braille device. This will use BrlAPI to display the braille output on a real
1394 @item net:@var{options}
1395 Network adapter that supports CDC ethernet and RNDIS protocols. @var{options}
1396 specifies NIC options as with @code{-net nic,}@var{options} (see description).
1397 For instance, user-mode networking can be used with
1399 qemu-system-i386 [...OPTIONS...] -net user,vlan=0 -usbdevice net:vlan=0
1401 Currently this cannot be used in machines that support PCI NICs.
1402 @item bt[:@var{hci-type}]
1403 Bluetooth dongle whose type is specified in the same format as with
1404 the @option{-bt hci} option, @pxref{bt-hcis,,allowed HCI types}. If
1405 no type is given, the HCI logic corresponds to @code{-bt hci,vlan=0}.
1406 This USB device implements the USB Transport Layer of HCI. Example
1409 @command{qemu-system-i386} [...@var{OPTIONS}...] @option{-usbdevice} bt:hci,vlan=3 @option{-bt} device:keyboard,vlan=3
1413 @node host_usb_devices
1414 @subsection Using host USB devices on a Linux host
1416 WARNING: this is an experimental feature. QEMU will slow down when
1417 using it. USB devices requiring real time streaming (i.e. USB Video
1418 Cameras) are not supported yet.
1421 @item If you use an early Linux 2.4 kernel, verify that no Linux driver
1422 is actually using the USB device. A simple way to do that is simply to
1423 disable the corresponding kernel module by renaming it from @file{mydriver.o}
1424 to @file{mydriver.o.disabled}.
1426 @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1432 @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:
1434 chown -R myuid /proc/bus/usb
1437 @item Launch QEMU and do in the monitor:
1440 Device 1.2, speed 480 Mb/s
1441 Class 00: USB device 1234:5678, USB DISK
1443 You should see the list of the devices you can use (Never try to use
1444 hubs, it won't work).
1446 @item Add the device in QEMU by using:
1448 usb_add host:1234:5678
1451 Normally the guest OS should report that a new USB device is
1452 plugged. You can use the option @option{-usbdevice} to do the same.
1454 @item Now you can try to use the host USB device in QEMU.
1458 When relaunching QEMU, you may have to unplug and plug again the USB
1459 device to make it work again (this is a bug).
1462 @section VNC security
1464 The VNC server capability provides access to the graphical console
1465 of the guest VM across the network. This has a number of security
1466 considerations depending on the deployment scenarios.
1470 * vnc_sec_password::
1471 * vnc_sec_certificate::
1472 * vnc_sec_certificate_verify::
1473 * vnc_sec_certificate_pw::
1475 * vnc_sec_certificate_sasl::
1476 * vnc_generate_cert::
1480 @subsection Without passwords
1482 The simplest VNC server setup does not include any form of authentication.
1483 For this setup it is recommended to restrict it to listen on a UNIX domain
1484 socket only. For example
1487 qemu-system-i386 [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
1490 This ensures that only users on local box with read/write access to that
1491 path can access the VNC server. To securely access the VNC server from a
1492 remote machine, a combination of netcat+ssh can be used to provide a secure
1495 @node vnc_sec_password
1496 @subsection With passwords
1498 The VNC protocol has limited support for password based authentication. Since
1499 the protocol limits passwords to 8 characters it should not be considered
1500 to provide high security. The password can be fairly easily brute-forced by
1501 a client making repeat connections. For this reason, a VNC server using password
1502 authentication should be restricted to only listen on the loopback interface
1503 or UNIX domain sockets. Password authentication is not supported when operating
1504 in FIPS 140-2 compliance mode as it requires the use of the DES cipher. Password
1505 authentication is requested with the @code{password} option, and then once QEMU
1506 is running the password is set with the monitor. Until the monitor is used to
1507 set the password all clients will be rejected.
1510 qemu-system-i386 [...OPTIONS...] -vnc :1,password -monitor stdio
1511 (qemu) change vnc password
1516 @node vnc_sec_certificate
1517 @subsection With x509 certificates
1519 The QEMU VNC server also implements the VeNCrypt extension allowing use of
1520 TLS for encryption of the session, and x509 certificates for authentication.
1521 The use of x509 certificates is strongly recommended, because TLS on its
1522 own is susceptible to man-in-the-middle attacks. Basic x509 certificate
1523 support provides a secure session, but no authentication. This allows any
1524 client to connect, and provides an encrypted session.
1527 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio
1530 In the above example @code{/etc/pki/qemu} should contain at least three files,
1531 @code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged
1532 users will want to use a private directory, for example @code{$HOME/.pki/qemu}.
1533 NB the @code{server-key.pem} file should be protected with file mode 0600 to
1534 only be readable by the user owning it.
1536 @node vnc_sec_certificate_verify
1537 @subsection With x509 certificates and client verification
1539 Certificates can also provide a means to authenticate the client connecting.
1540 The server will request that the client provide a certificate, which it will
1541 then validate against the CA certificate. This is a good choice if deploying
1542 in an environment with a private internal certificate authority.
1545 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
1549 @node vnc_sec_certificate_pw
1550 @subsection With x509 certificates, client verification and passwords
1552 Finally, the previous method can be combined with VNC password authentication
1553 to provide two layers of authentication for clients.
1556 qemu-system-i386 [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
1557 (qemu) change vnc password
1564 @subsection With SASL authentication
1566 The SASL authentication method is a VNC extension, that provides an
1567 easily extendable, pluggable authentication method. This allows for
1568 integration with a wide range of authentication mechanisms, such as
1569 PAM, GSSAPI/Kerberos, LDAP, SQL databases, one-time keys and more.
1570 The strength of the authentication depends on the exact mechanism
1571 configured. If the chosen mechanism also provides a SSF layer, then
1572 it will encrypt the datastream as well.
1574 Refer to the later docs on how to choose the exact SASL mechanism
1575 used for authentication, but assuming use of one supporting SSF,
1576 then QEMU can be launched with:
1579 qemu-system-i386 [...OPTIONS...] -vnc :1,sasl -monitor stdio
1582 @node vnc_sec_certificate_sasl
1583 @subsection With x509 certificates and SASL authentication
1585 If the desired SASL authentication mechanism does not supported
1586 SSF layers, then it is strongly advised to run it in combination
1587 with TLS and x509 certificates. This provides securely encrypted
1588 data stream, avoiding risk of compromising of the security
1589 credentials. This can be enabled, by combining the 'sasl' option
1590 with the aforementioned TLS + x509 options:
1593 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509,sasl -monitor stdio
1597 @node vnc_generate_cert
1598 @subsection Generating certificates for VNC
1600 The GNU TLS packages provides a command called @code{certtool} which can
1601 be used to generate certificates and keys in PEM format. At a minimum it
1602 is necessary to setup a certificate authority, and issue certificates to
1603 each server. If using certificates for authentication, then each client
1604 will also need to be issued a certificate. The recommendation is for the
1605 server to keep its certificates in either @code{/etc/pki/qemu} or for
1606 unprivileged users in @code{$HOME/.pki/qemu}.
1610 * vnc_generate_server::
1611 * vnc_generate_client::
1613 @node vnc_generate_ca
1614 @subsubsection Setup the Certificate Authority
1616 This step only needs to be performed once per organization / organizational
1617 unit. First the CA needs a private key. This key must be kept VERY secret
1618 and secure. If this key is compromised the entire trust chain of the certificates
1619 issued with it is lost.
1622 # certtool --generate-privkey > ca-key.pem
1625 A CA needs to have a public certificate. For simplicity it can be a self-signed
1626 certificate, or one issue by a commercial certificate issuing authority. To
1627 generate a self-signed certificate requires one core piece of information, the
1628 name of the organization.
1631 # cat > ca.info <<EOF
1632 cn = Name of your organization
1636 # certtool --generate-self-signed \
1637 --load-privkey ca-key.pem
1638 --template ca.info \
1639 --outfile ca-cert.pem
1642 The @code{ca-cert.pem} file should be copied to all servers and clients wishing to utilize
1643 TLS support in the VNC server. The @code{ca-key.pem} must not be disclosed/copied at all.
1645 @node vnc_generate_server
1646 @subsubsection Issuing server certificates
1648 Each server (or host) needs to be issued with a key and certificate. When connecting
1649 the certificate is sent to the client which validates it against the CA certificate.
1650 The core piece of information for a server certificate is the hostname. This should
1651 be the fully qualified hostname that the client will connect with, since the client
1652 will typically also verify the hostname in the certificate. On the host holding the
1653 secure CA private key:
1656 # cat > server.info <<EOF
1657 organization = Name of your organization
1658 cn = server.foo.example.com
1663 # certtool --generate-privkey > server-key.pem
1664 # certtool --generate-certificate \
1665 --load-ca-certificate ca-cert.pem \
1666 --load-ca-privkey ca-key.pem \
1667 --load-privkey server-key.pem \
1668 --template server.info \
1669 --outfile server-cert.pem
1672 The @code{server-key.pem} and @code{server-cert.pem} files should now be securely copied
1673 to the server for which they were generated. The @code{server-key.pem} is security
1674 sensitive and should be kept protected with file mode 0600 to prevent disclosure.
1676 @node vnc_generate_client
1677 @subsubsection Issuing client certificates
1679 If the QEMU VNC server is to use the @code{x509verify} option to validate client
1680 certificates as its authentication mechanism, each client also needs to be issued
1681 a certificate. The client certificate contains enough metadata to uniquely identify
1682 the client, typically organization, state, city, building, etc. On the host holding
1683 the secure CA private key:
1686 # cat > client.info <<EOF
1690 organization = Name of your organization
1691 cn = client.foo.example.com
1696 # certtool --generate-privkey > client-key.pem
1697 # certtool --generate-certificate \
1698 --load-ca-certificate ca-cert.pem \
1699 --load-ca-privkey ca-key.pem \
1700 --load-privkey client-key.pem \
1701 --template client.info \
1702 --outfile client-cert.pem
1705 The @code{client-key.pem} and @code{client-cert.pem} files should now be securely
1706 copied to the client for which they were generated.
1709 @node vnc_setup_sasl
1711 @subsection Configuring SASL mechanisms
1713 The following documentation assumes use of the Cyrus SASL implementation on a
1714 Linux host, but the principals should apply to any other SASL impl. When SASL
1715 is enabled, the mechanism configuration will be loaded from system default
1716 SASL service config /etc/sasl2/qemu.conf. If running QEMU as an
1717 unprivileged user, an environment variable SASL_CONF_PATH can be used
1718 to make it search alternate locations for the service config.
1720 The default configuration might contain
1723 mech_list: digest-md5
1724 sasldb_path: /etc/qemu/passwd.db
1727 This says to use the 'Digest MD5' mechanism, which is similar to the HTTP
1728 Digest-MD5 mechanism. The list of valid usernames & passwords is maintained
1729 in the /etc/qemu/passwd.db file, and can be updated using the saslpasswd2
1730 command. While this mechanism is easy to configure and use, it is not
1731 considered secure by modern standards, so only suitable for developers /
1734 A more serious deployment might use Kerberos, which is done with the 'gssapi'
1739 keytab: /etc/qemu/krb5.tab
1742 For this to work the administrator of your KDC must generate a Kerberos
1743 principal for the server, with a name of 'qemu/somehost.example.com@@EXAMPLE.COM'
1744 replacing 'somehost.example.com' with the fully qualified host name of the
1745 machine running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.
1747 Other configurations will be left as an exercise for the reader. It should
1748 be noted that only Digest-MD5 and GSSAPI provides a SSF layer for data
1749 encryption. For all other mechanisms, VNC should always be configured to
1750 use TLS and x509 certificates to protect security credentials from snooping.
1755 QEMU has a primitive support to work with gdb, so that you can do
1756 'Ctrl-C' while the virtual machine is running and inspect its state.
1758 In order to use gdb, launch QEMU with the '-s' option. It will wait for a
1761 qemu-system-i386 -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1762 -append "root=/dev/hda"
1763 Connected to host network interface: tun0
1764 Waiting gdb connection on port 1234
1767 Then launch gdb on the 'vmlinux' executable:
1772 In gdb, connect to QEMU:
1774 (gdb) target remote localhost:1234
1777 Then you can use gdb normally. For example, type 'c' to launch the kernel:
1782 Here are some useful tips in order to use gdb on system code:
1786 Use @code{info reg} to display all the CPU registers.
1788 Use @code{x/10i $eip} to display the code at the PC position.
1790 Use @code{set architecture i8086} to dump 16 bit code. Then use
1791 @code{x/10i $cs*16+$eip} to dump the code at the PC position.
1794 Advanced debugging options:
1796 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:
1798 @item maintenance packet qqemu.sstepbits
1800 This will display the MASK bits used to control the single stepping IE:
1802 (gdb) maintenance packet qqemu.sstepbits
1803 sending: "qqemu.sstepbits"
1804 received: "ENABLE=1,NOIRQ=2,NOTIMER=4"
1806 @item maintenance packet qqemu.sstep
1808 This will display the current value of the mask used when single stepping IE:
1810 (gdb) maintenance packet qqemu.sstep
1811 sending: "qqemu.sstep"
1814 @item maintenance packet Qqemu.sstep=HEX_VALUE
1816 This will change the single step mask, so if wanted to enable IRQs on the single step, but not timers, you would use:
1818 (gdb) maintenance packet Qqemu.sstep=0x5
1819 sending: "qemu.sstep=0x5"
1824 @node pcsys_os_specific
1825 @section Target OS specific information
1829 To have access to SVGA graphic modes under X11, use the @code{vesa} or
1830 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1831 color depth in the guest and the host OS.
1833 When using a 2.6 guest Linux kernel, you should add the option
1834 @code{clock=pit} on the kernel command line because the 2.6 Linux
1835 kernels make very strict real time clock checks by default that QEMU
1836 cannot simulate exactly.
1838 When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1839 not activated because QEMU is slower with this patch. The QEMU
1840 Accelerator Module is also much slower in this case. Earlier Fedora
1841 Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this
1842 patch by default. Newer kernels don't have it.
1846 If you have a slow host, using Windows 95 is better as it gives the
1847 best speed. Windows 2000 is also a good choice.
1849 @subsubsection SVGA graphic modes support
1851 QEMU emulates a Cirrus Logic GD5446 Video
1852 card. All Windows versions starting from Windows 95 should recognize
1853 and use this graphic card. For optimal performances, use 16 bit color
1854 depth in the guest and the host OS.
1856 If you are using Windows XP as guest OS and if you want to use high
1857 resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
1858 1280x1024x16), then you should use the VESA VBE virtual graphic card
1859 (option @option{-std-vga}).
1861 @subsubsection CPU usage reduction
1863 Windows 9x does not correctly use the CPU HLT
1864 instruction. The result is that it takes host CPU cycles even when
1865 idle. You can install the utility from
1866 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
1867 problem. Note that no such tool is needed for NT, 2000 or XP.
1869 @subsubsection Windows 2000 disk full problem
1871 Windows 2000 has a bug which gives a disk full problem during its
1872 installation. When installing it, use the @option{-win2k-hack} QEMU
1873 option to enable a specific workaround. After Windows 2000 is
1874 installed, you no longer need this option (this option slows down the
1877 @subsubsection Windows 2000 shutdown
1879 Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1880 can. It comes from the fact that Windows 2000 does not automatically
1881 use the APM driver provided by the BIOS.
1883 In order to correct that, do the following (thanks to Struan
1884 Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1885 Add/Troubleshoot a device => Add a new device & Next => No, select the
1886 hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1887 (again) a few times. Now the driver is installed and Windows 2000 now
1888 correctly instructs QEMU to shutdown at the appropriate moment.
1890 @subsubsection Share a directory between Unix and Windows
1892 See @ref{sec_invocation} about the help of the option @option{-smb}.
1894 @subsubsection Windows XP security problem
1896 Some releases of Windows XP install correctly but give a security
1899 A problem is preventing Windows from accurately checking the
1900 license for this computer. Error code: 0x800703e6.
1903 The workaround is to install a service pack for XP after a boot in safe
1904 mode. Then reboot, and the problem should go away. Since there is no
1905 network while in safe mode, its recommended to download the full
1906 installation of SP1 or SP2 and transfer that via an ISO or using the
1907 vvfat block device ("-hdb fat:directory_which_holds_the_SP").
1909 @subsection MS-DOS and FreeDOS
1911 @subsubsection CPU usage reduction
1913 DOS does not correctly use the CPU HLT instruction. The result is that
1914 it takes host CPU cycles even when idle. You can install the utility
1915 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1918 @node QEMU System emulator for non PC targets
1919 @chapter QEMU System emulator for non PC targets
1921 QEMU is a generic emulator and it emulates many non PC
1922 machines. Most of the options are similar to the PC emulator. The
1923 differences are mentioned in the following sections.
1926 * PowerPC System emulator::
1927 * Sparc32 System emulator::
1928 * Sparc64 System emulator::
1929 * MIPS System emulator::
1930 * ARM System emulator::
1931 * ColdFire System emulator::
1932 * Cris System emulator::
1933 * Microblaze System emulator::
1934 * SH4 System emulator::
1935 * Xtensa System emulator::
1938 @node PowerPC System emulator
1939 @section PowerPC System emulator
1940 @cindex system emulation (PowerPC)
1942 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1943 or PowerMac PowerPC system.
1945 QEMU emulates the following PowerMac peripherals:
1949 UniNorth or Grackle PCI Bridge
1951 PCI VGA compatible card with VESA Bochs Extensions
1953 2 PMAC IDE interfaces with hard disk and CD-ROM support
1959 VIA-CUDA with ADB keyboard and mouse.
1962 QEMU emulates the following PREP peripherals:
1968 PCI VGA compatible card with VESA Bochs Extensions
1970 2 IDE interfaces with hard disk and CD-ROM support
1974 NE2000 network adapters
1978 PREP Non Volatile RAM
1980 PC compatible keyboard and mouse.
1983 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
1984 @url{http://perso.magic.fr/l_indien/OpenHackWare/index.htm}.
1986 Since version 0.9.1, QEMU uses OpenBIOS @url{http://www.openbios.org/}
1987 for the g3beige and mac99 PowerMac machines. OpenBIOS is a free (GPL
1988 v2) portable firmware implementation. The goal is to implement a 100%
1989 IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.
1991 @c man begin OPTIONS
1993 The following options are specific to the PowerPC emulation:
1997 @item -g @var{W}x@var{H}[x@var{DEPTH}]
1999 Set the initial VGA graphic mode. The default is 800x600x32.
2001 @item -prom-env @var{string}
2003 Set OpenBIOS variables in NVRAM, for example:
2006 qemu-system-ppc -prom-env 'auto-boot?=false' \
2007 -prom-env 'boot-device=hd:2,\yaboot' \
2008 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
2011 These variables are not used by Open Hack'Ware.
2018 More information is available at
2019 @url{http://perso.magic.fr/l_indien/qemu-ppc/}.
2021 @node Sparc32 System emulator
2022 @section Sparc32 System emulator
2023 @cindex system emulation (Sparc32)
2025 Use the executable @file{qemu-system-sparc} to simulate the following
2026 Sun4m architecture machines:
2041 SPARCstation Voyager
2048 The emulation is somewhat complete. SMP up to 16 CPUs is supported,
2049 but Linux limits the number of usable CPUs to 4.
2051 QEMU emulates the following sun4m peripherals:
2057 TCX or cgthree Frame buffer
2059 Lance (Am7990) Ethernet
2061 Non Volatile RAM M48T02/M48T08
2063 Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
2064 and power/reset logic
2066 ESP SCSI controller with hard disk and CD-ROM support
2068 Floppy drive (not on SS-600MP)
2070 CS4231 sound device (only on SS-5, not working yet)
2073 The number of peripherals is fixed in the architecture. Maximum
2074 memory size depends on the machine type, for SS-5 it is 256MB and for
2077 Since version 0.8.2, QEMU uses OpenBIOS
2078 @url{http://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
2079 firmware implementation. The goal is to implement a 100% IEEE
2080 1275-1994 (referred to as Open Firmware) compliant firmware.
2082 A sample Linux 2.6 series kernel and ram disk image are available on
2083 the QEMU web site. There are still issues with NetBSD and OpenBSD, but
2084 most kernel versions work. Please note that currently older Solaris kernels
2085 don't work probably due to interface issues between OpenBIOS and
2088 @c man begin OPTIONS
2090 The following options are specific to the Sparc32 emulation:
2094 @item -g @var{W}x@var{H}x[x@var{DEPTH}]
2096 Set the initial graphics mode. For TCX, the default is 1024x768x8 with the
2097 option of 1024x768x24. For cgthree, the default is 1024x768x8 with the option
2098 of 1152x900x8 for people who wish to use OBP.
2100 @item -prom-env @var{string}
2102 Set OpenBIOS variables in NVRAM, for example:
2105 qemu-system-sparc -prom-env 'auto-boot?=false' \
2106 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
2109 @item -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic] [|SPARCbook]
2111 Set the emulated machine type. Default is SS-5.
2117 @node Sparc64 System emulator
2118 @section Sparc64 System emulator
2119 @cindex system emulation (Sparc64)
2121 Use the executable @file{qemu-system-sparc64} to simulate a Sun4u
2122 (UltraSPARC PC-like machine), Sun4v (T1 PC-like machine), or generic
2123 Niagara (T1) machine. The Sun4u emulator is mostly complete, being
2124 able to run Linux, NetBSD and OpenBSD in headless (-nographic) mode. The
2125 Sun4v and Niagara emulators are still a work in progress.
2127 QEMU emulates the following peripherals:
2131 UltraSparc IIi APB PCI Bridge
2133 PCI VGA compatible card with VESA Bochs Extensions
2135 PS/2 mouse and keyboard
2137 Non Volatile RAM M48T59
2139 PC-compatible serial ports
2141 2 PCI IDE interfaces with hard disk and CD-ROM support
2146 @c man begin OPTIONS
2148 The following options are specific to the Sparc64 emulation:
2152 @item -prom-env @var{string}
2154 Set OpenBIOS variables in NVRAM, for example:
2157 qemu-system-sparc64 -prom-env 'auto-boot?=false'
2160 @item -M [sun4u|sun4v|Niagara]
2162 Set the emulated machine type. The default is sun4u.
2168 @node MIPS System emulator
2169 @section MIPS System emulator
2170 @cindex system emulation (MIPS)
2172 Four executables cover simulation of 32 and 64-bit MIPS systems in
2173 both endian options, @file{qemu-system-mips}, @file{qemu-system-mipsel}
2174 @file{qemu-system-mips64} and @file{qemu-system-mips64el}.
2175 Five different machine types are emulated:
2179 A generic ISA PC-like machine "mips"
2181 The MIPS Malta prototype board "malta"
2183 An ACER Pica "pica61". This machine needs the 64-bit emulator.
2185 MIPS emulator pseudo board "mipssim"
2187 A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator.
2190 The generic emulation is supported by Debian 'Etch' and is able to
2191 install Debian into a virtual disk image. The following devices are
2196 A range of MIPS CPUs, default is the 24Kf
2198 PC style serial port
2205 The Malta emulation supports the following devices:
2209 Core board with MIPS 24Kf CPU and Galileo system controller
2211 PIIX4 PCI/USB/SMbus controller
2213 The Multi-I/O chip's serial device
2215 PCI network cards (PCnet32 and others)
2217 Malta FPGA serial device
2219 Cirrus (default) or any other PCI VGA graphics card
2222 The ACER Pica emulation supports:
2228 PC-style IRQ and DMA controllers
2235 The mipssim pseudo board emulation provides an environment similar
2236 to what the proprietary MIPS emulator uses for running Linux.
2241 A range of MIPS CPUs, default is the 24Kf
2243 PC style serial port
2245 MIPSnet network emulation
2248 The MIPS Magnum R4000 emulation supports:
2254 PC-style IRQ controller
2264 @node ARM System emulator
2265 @section ARM System emulator
2266 @cindex system emulation (ARM)
2268 Use the executable @file{qemu-system-arm} to simulate a ARM
2269 machine. The ARM Integrator/CP board is emulated with the following
2274 ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU
2278 SMC 91c111 Ethernet adapter
2280 PL110 LCD controller
2282 PL050 KMI with PS/2 keyboard and mouse.
2284 PL181 MultiMedia Card Interface with SD card.
2287 The ARM Versatile baseboard is emulated with the following devices:
2291 ARM926E, ARM1136 or Cortex-A8 CPU
2293 PL190 Vectored Interrupt Controller
2297 SMC 91c111 Ethernet adapter
2299 PL110 LCD controller
2301 PL050 KMI with PS/2 keyboard and mouse.
2303 PCI host bridge. Note the emulated PCI bridge only provides access to
2304 PCI memory space. It does not provide access to PCI IO space.
2305 This means some devices (eg. ne2k_pci NIC) are not usable, and others
2306 (eg. rtl8139 NIC) are only usable when the guest drivers use the memory
2307 mapped control registers.
2309 PCI OHCI USB controller.
2311 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
2313 PL181 MultiMedia Card Interface with SD card.
2316 Several variants of the ARM RealView baseboard are emulated,
2317 including the EB, PB-A8 and PBX-A9. Due to interactions with the
2318 bootloader, only certain Linux kernel configurations work out
2319 of the box on these boards.
2321 Kernels for the PB-A8 board should have CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2322 enabled in the kernel, and expect 512M RAM. Kernels for The PBX-A9 board
2323 should have CONFIG_SPARSEMEM enabled, CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2324 disabled and expect 1024M RAM.
2326 The following devices are emulated:
2330 ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU
2332 ARM AMBA Generic/Distributed Interrupt Controller
2336 SMC 91c111 or SMSC LAN9118 Ethernet adapter
2338 PL110 LCD controller
2340 PL050 KMI with PS/2 keyboard and mouse
2344 PCI OHCI USB controller
2346 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
2348 PL181 MultiMedia Card Interface with SD card.
2351 The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
2352 and "Terrier") emulation includes the following peripherals:
2356 Intel PXA270 System-on-chip (ARM V5TE core)
2360 IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
2362 On-chip OHCI USB controller
2364 On-chip LCD controller
2366 On-chip Real Time Clock
2368 TI ADS7846 touchscreen controller on SSP bus
2370 Maxim MAX1111 analog-digital converter on I@math{^2}C bus
2372 GPIO-connected keyboard controller and LEDs
2374 Secure Digital card connected to PXA MMC/SD host
2378 WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
2381 The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the
2386 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2388 ROM and RAM memories (ROM firmware image can be loaded with -option-rom)
2390 On-chip LCD controller
2392 On-chip Real Time Clock
2394 TI TSC2102i touchscreen controller / analog-digital converter / Audio
2395 CODEC, connected through MicroWire and I@math{^2}S busses
2397 GPIO-connected matrix keypad
2399 Secure Digital card connected to OMAP MMC/SD host
2404 Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48)
2405 emulation supports the following elements:
2409 Texas Instruments OMAP2420 System-on-chip (ARM 1136 core)
2411 RAM and non-volatile OneNAND Flash memories
2413 Display connected to EPSON remote framebuffer chip and OMAP on-chip
2414 display controller and a LS041y3 MIPI DBI-C controller
2416 TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers
2417 driven through SPI bus
2419 National Semiconductor LM8323-controlled qwerty keyboard driven
2420 through I@math{^2}C bus
2422 Secure Digital card connected to OMAP MMC/SD host
2424 Three OMAP on-chip UARTs and on-chip STI debugging console
2426 A Bluetooth(R) transceiver and HCI connected to an UART
2428 Mentor Graphics "Inventra" dual-role USB controller embedded in a TI
2429 TUSB6010 chip - only USB host mode is supported
2431 TI TMP105 temperature sensor driven through I@math{^2}C bus
2433 TI TWL92230C power management companion with an RTC on I@math{^2}C bus
2435 Nokia RETU and TAHVO multi-purpose chips with an RTC, connected
2439 The Luminary Micro Stellaris LM3S811EVB emulation includes the following
2446 64k Flash and 8k SRAM.
2448 Timers, UARTs, ADC and I@math{^2}C interface.
2450 OSRAM Pictiva 96x16 OLED with SSD0303 controller on I@math{^2}C bus.
2453 The Luminary Micro Stellaris LM3S6965EVB emulation includes the following
2460 256k Flash and 64k SRAM.
2462 Timers, UARTs, ADC, I@math{^2}C and SSI interfaces.
2464 OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI.
2467 The Freecom MusicPal internet radio emulation includes the following
2472 Marvell MV88W8618 ARM core.
2474 32 MB RAM, 256 KB SRAM, 8 MB flash.
2478 MV88W8xx8 Ethernet controller
2480 MV88W8618 audio controller, WM8750 CODEC and mixer
2482 128×64 display with brightness control
2484 2 buttons, 2 navigation wheels with button function
2487 The Siemens SX1 models v1 and v2 (default) basic emulation.
2488 The emulation includes the following elements:
2492 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2494 ROM and RAM memories (ROM firmware image can be loaded with -pflash)
2496 1 Flash of 16MB and 1 Flash of 8MB
2500 On-chip LCD controller
2502 On-chip Real Time Clock
2504 Secure Digital card connected to OMAP MMC/SD host
2509 A Linux 2.6 test image is available on the QEMU web site. More
2510 information is available in the QEMU mailing-list archive.
2512 @c man begin OPTIONS
2514 The following options are specific to the ARM emulation:
2519 Enable semihosting syscall emulation.
2521 On ARM this implements the "Angel" interface.
2523 Note that this allows guest direct access to the host filesystem,
2524 so should only be used with trusted guest OS.
2528 @node ColdFire System emulator
2529 @section ColdFire System emulator
2530 @cindex system emulation (ColdFire)
2531 @cindex system emulation (M68K)
2533 Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2534 The emulator is able to boot a uClinux kernel.
2536 The M5208EVB emulation includes the following devices:
2540 MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2542 Three Two on-chip UARTs.
2544 Fast Ethernet Controller (FEC)
2547 The AN5206 emulation includes the following devices:
2551 MCF5206 ColdFire V2 Microprocessor.
2556 @c man begin OPTIONS
2558 The following options are specific to the ColdFire emulation:
2563 Enable semihosting syscall emulation.
2565 On M68K this implements the "ColdFire GDB" interface used by libgloss.
2567 Note that this allows guest direct access to the host filesystem,
2568 so should only be used with trusted guest OS.
2572 @node Cris System emulator
2573 @section Cris System emulator
2574 @cindex system emulation (Cris)
2578 @node Microblaze System emulator
2579 @section Microblaze System emulator
2580 @cindex system emulation (Microblaze)
2584 @node SH4 System emulator
2585 @section SH4 System emulator
2586 @cindex system emulation (SH4)
2590 @node Xtensa System emulator
2591 @section Xtensa System emulator
2592 @cindex system emulation (Xtensa)
2594 Two executables cover simulation of both Xtensa endian options,
2595 @file{qemu-system-xtensa} and @file{qemu-system-xtensaeb}.
2596 Two different machine types are emulated:
2600 Xtensa emulator pseudo board "sim"
2602 Avnet LX60/LX110/LX200 board
2605 The sim pseudo board emulation provides an environment similar
2606 to one provided by the proprietary Tensilica ISS.
2611 A range of Xtensa CPUs, default is the DC232B
2613 Console and filesystem access via semihosting calls
2616 The Avnet LX60/LX110/LX200 emulation supports:
2620 A range of Xtensa CPUs, default is the DC232B
2624 OpenCores 10/100 Mbps Ethernet MAC
2627 @c man begin OPTIONS
2629 The following options are specific to the Xtensa emulation:
2634 Enable semihosting syscall emulation.
2636 Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select.
2637 Tensilica baremetal libc for ISS and linux platform "sim" use this interface.
2639 Note that this allows guest direct access to the host filesystem,
2640 so should only be used with trusted guest OS.
2643 @node QEMU User space emulator
2644 @chapter QEMU User space emulator
2647 * Supported Operating Systems ::
2648 * Linux User space emulator::
2649 * BSD User space emulator ::
2652 @node Supported Operating Systems
2653 @section Supported Operating Systems
2655 The following OS are supported in user space emulation:
2659 Linux (referred as qemu-linux-user)
2661 BSD (referred as qemu-bsd-user)
2664 @node Linux User space emulator
2665 @section Linux User space emulator
2670 * Command line options::
2675 @subsection Quick Start
2677 In order to launch a Linux process, QEMU needs the process executable
2678 itself and all the target (x86) dynamic libraries used by it.
2682 @item On x86, you can just try to launch any process by using the native
2686 qemu-i386 -L / /bin/ls
2689 @code{-L /} tells that the x86 dynamic linker must be searched with a
2692 @item Since QEMU is also a linux process, you can launch QEMU with
2693 QEMU (NOTE: you can only do that if you compiled QEMU from the sources):
2696 qemu-i386 -L / qemu-i386 -L / /bin/ls
2699 @item On non x86 CPUs, you need first to download at least an x86 glibc
2700 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2701 @code{LD_LIBRARY_PATH} is not set:
2704 unset LD_LIBRARY_PATH
2707 Then you can launch the precompiled @file{ls} x86 executable:
2710 qemu-i386 tests/i386/ls
2712 You can look at @file{scripts/qemu-binfmt-conf.sh} so that
2713 QEMU is automatically launched by the Linux kernel when you try to
2714 launch x86 executables. It requires the @code{binfmt_misc} module in the
2717 @item The x86 version of QEMU is also included. You can try weird things such as:
2719 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2720 /usr/local/qemu-i386/bin/ls-i386
2726 @subsection Wine launch
2730 @item Ensure that you have a working QEMU with the x86 glibc
2731 distribution (see previous section). In order to verify it, you must be
2735 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2738 @item Download the binary x86 Wine install
2739 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2741 @item Configure Wine on your account. Look at the provided script
2742 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2743 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2745 @item Then you can try the example @file{putty.exe}:
2748 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2749 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2754 @node Command line options
2755 @subsection Command line options
2758 @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}...]
2765 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2767 Set the x86 stack size in bytes (default=524288)
2769 Select CPU model (-cpu help for list and additional feature selection)
2770 @item -E @var{var}=@var{value}
2771 Set environment @var{var} to @var{value}.
2773 Remove @var{var} from the environment.
2775 Offset guest address by the specified number of bytes. This is useful when
2776 the address region required by guest applications is reserved on the host.
2777 This option is currently only supported on some hosts.
2779 Pre-allocate a guest virtual address space of the given size (in bytes).
2780 "G", "M", and "k" suffixes may be used when specifying the size.
2787 Activate logging of the specified items (use '-d help' for a list of log items)
2789 Act as if the host page size was 'pagesize' bytes
2791 Wait gdb connection to port
2793 Run the emulation in single step mode.
2796 Environment variables:
2800 Print system calls and arguments similar to the 'strace' program
2801 (NOTE: the actual 'strace' program will not work because the user
2802 space emulator hasn't implemented ptrace). At the moment this is
2803 incomplete. All system calls that don't have a specific argument
2804 format are printed with information for six arguments. Many
2805 flag-style arguments don't have decoders and will show up as numbers.
2808 @node Other binaries
2809 @subsection Other binaries
2811 @cindex user mode (Alpha)
2812 @command{qemu-alpha} TODO.
2814 @cindex user mode (ARM)
2815 @command{qemu-armeb} TODO.
2817 @cindex user mode (ARM)
2818 @command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2819 binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2820 configurations), and arm-uclinux bFLT format binaries.
2822 @cindex user mode (ColdFire)
2823 @cindex user mode (M68K)
2824 @command{qemu-m68k} is capable of running semihosted binaries using the BDM
2825 (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2826 coldfire uClinux bFLT format binaries.
2828 The binary format is detected automatically.
2830 @cindex user mode (Cris)
2831 @command{qemu-cris} TODO.
2833 @cindex user mode (i386)
2834 @command{qemu-i386} TODO.
2835 @command{qemu-x86_64} TODO.
2837 @cindex user mode (Microblaze)
2838 @command{qemu-microblaze} TODO.
2840 @cindex user mode (MIPS)
2841 @command{qemu-mips} TODO.
2842 @command{qemu-mipsel} TODO.
2844 @cindex user mode (PowerPC)
2845 @command{qemu-ppc64abi32} TODO.
2846 @command{qemu-ppc64} TODO.
2847 @command{qemu-ppc} TODO.
2849 @cindex user mode (SH4)
2850 @command{qemu-sh4eb} TODO.
2851 @command{qemu-sh4} TODO.
2853 @cindex user mode (SPARC)
2854 @command{qemu-sparc} can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).
2856 @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2857 (Sparc64 CPU, 32 bit ABI).
2859 @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2860 SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2862 @node BSD User space emulator
2863 @section BSD User space emulator
2868 * BSD Command line options::
2872 @subsection BSD Status
2876 target Sparc64 on Sparc64: Some trivial programs work.
2879 @node BSD Quick Start
2880 @subsection Quick Start
2882 In order to launch a BSD process, QEMU needs the process executable
2883 itself and all the target dynamic libraries used by it.
2887 @item On Sparc64, you can just try to launch any process by using the native
2891 qemu-sparc64 /bin/ls
2896 @node BSD Command line options
2897 @subsection Command line options
2900 @command{qemu-sparc64} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-bsd} @var{type}] @var{program} [@var{arguments}...]
2907 Set the library root path (default=/)
2909 Set the stack size in bytes (default=524288)
2910 @item -ignore-environment
2911 Start with an empty environment. Without this option,
2912 the initial environment is a copy of the caller's environment.
2913 @item -E @var{var}=@var{value}
2914 Set environment @var{var} to @var{value}.
2916 Remove @var{var} from the environment.
2918 Set the type of the emulated BSD Operating system. Valid values are
2919 FreeBSD, NetBSD and OpenBSD (default).
2926 Activate logging of the specified items (use '-d help' for a list of log items)
2928 Act as if the host page size was 'pagesize' bytes
2930 Run the emulation in single step mode.
2934 @chapter Compilation from the sources
2939 * Cross compilation for Windows with Linux::
2947 @subsection Compilation
2949 First you must decompress the sources:
2952 tar zxvf qemu-x.y.z.tar.gz
2956 Then you configure QEMU and build it (usually no options are needed):
2962 Then type as root user:
2966 to install QEMU in @file{/usr/local}.
2972 @item Install the current versions of MSYS and MinGW from
2973 @url{http://www.mingw.org/}. You can find detailed installation
2974 instructions in the download section and the FAQ.
2977 the MinGW development library of SDL 1.2.x
2978 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
2979 @url{http://www.libsdl.org}. Unpack it in a temporary place and
2980 edit the @file{sdl-config} script so that it gives the
2981 correct SDL directory when invoked.
2983 @item Install the MinGW version of zlib and make sure
2984 @file{zlib.h} and @file{libz.dll.a} are in
2985 MinGW's default header and linker search paths.
2987 @item Extract the current version of QEMU.
2989 @item Start the MSYS shell (file @file{msys.bat}).
2991 @item Change to the QEMU directory. Launch @file{./configure} and
2992 @file{make}. If you have problems using SDL, verify that
2993 @file{sdl-config} can be launched from the MSYS command line.
2995 @item You can install QEMU in @file{Program Files/QEMU} by typing
2996 @file{make install}. Don't forget to copy @file{SDL.dll} in
2997 @file{Program Files/QEMU}.
3001 @node Cross compilation for Windows with Linux
3002 @section Cross compilation for Windows with Linux
3006 Install the MinGW cross compilation tools available at
3007 @url{http://www.mingw.org/}.
3010 the MinGW development library of SDL 1.2.x
3011 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
3012 @url{http://www.libsdl.org}. Unpack it in a temporary place and
3013 edit the @file{sdl-config} script so that it gives the
3014 correct SDL directory when invoked. Set up the @code{PATH} environment
3015 variable so that @file{sdl-config} can be launched by
3016 the QEMU configuration script.
3018 @item Install the MinGW version of zlib and make sure
3019 @file{zlib.h} and @file{libz.dll.a} are in
3020 MinGW's default header and linker search paths.
3023 Configure QEMU for Windows cross compilation:
3025 PATH=/usr/i686-pc-mingw32/sys-root/mingw/bin:$PATH ./configure --cross-prefix='i686-pc-mingw32-'
3027 The example assumes @file{sdl-config} is installed under @file{/usr/i686-pc-mingw32/sys-root/mingw/bin} and
3028 MinGW cross compilation tools have names like @file{i686-pc-mingw32-gcc} and @file{i686-pc-mingw32-strip}.
3029 We set the @code{PATH} environment variable to ensure the MinGW version of @file{sdl-config} is used and
3030 use --cross-prefix to specify the name of the cross compiler.
3031 You can also use --prefix to set the Win32 install path which defaults to @file{c:/Program Files/QEMU}.
3033 Under Fedora Linux, you can run:
3035 yum -y install mingw32-gcc mingw32-SDL mingw32-zlib
3037 to get a suitable cross compilation environment.
3039 @item You can install QEMU in the installation directory by typing
3040 @code{make install}. Don't forget to copy @file{SDL.dll} and @file{zlib1.dll} into the
3041 installation directory.
3045 Wine can be used to launch the resulting qemu-system-i386.exe
3046 and all other qemu-system-@var{target}.exe compiled for Win32.
3051 System Requirements:
3053 @item Mac OS 10.5 or higher
3054 @item The clang compiler shipped with Xcode 4.2 or higher,
3055 or GCC 4.3 or higher
3058 Additional Requirements (install in order):
3060 @item libffi: @uref{https://sourceware.org/libffi/}
3061 @item gettext: @uref{http://www.gnu.org/software/gettext/}
3062 @item glib: @uref{http://ftp.gnome.org/pub/GNOME/sources/glib/}
3063 @item pkg-config: @uref{http://www.freedesktop.org/wiki/Software/pkg-config/}
3064 @item autoconf: @uref{http://www.gnu.org/software/autoconf/autoconf.html}
3065 @item automake: @uref{http://www.gnu.org/software/automake/}
3066 @item libtool: @uref{http://www.gnu.org/software/libtool/}
3067 @item pixman: @uref{http://www.pixman.org/}
3070 * You may find it easiest to get these from a third-party packager
3071 such as Homebrew, Macports, or Fink.
3073 After downloading the QEMU source code, double-click it to expand it.
3075 Then configure and make QEMU:
3081 If you have a recent version of Mac OS X (OSX 10.7 or better
3082 with Xcode 4.2 or better) we recommend building QEMU with the
3083 default compiler provided by Apple, for your version of Mac OS X
3084 (which will be 'clang'). The configure script will
3085 automatically pick this.
3087 Note: If after the configure step you see a message like this:
3089 ERROR: Your compiler does not support the __thread specifier for
3090 Thread-Local Storage (TLS). Please upgrade to a version that does.
3092 you may have to build your own version of gcc from source. Expect that to take
3093 several hours. More information can be found here:
3094 @uref{https://gcc.gnu.org/install/} @*
3096 These are some of the third party binaries of gcc available for download:
3098 @item Homebrew: @uref{http://brew.sh/}
3099 @item @uref{https://www.litebeam.net/gcc/gcc_472.pkg}
3100 @item @uref{http://www.macports.org/ports.php?by=name&substr=gcc}
3103 You can have several versions of GCC on your system. To specify a certain version,
3104 use the --cc and --cxx options.
3106 ./configure --cxx=<path of your c++ compiler> --cc=<path of your c compiler> <other options>
3110 @section Make targets
3116 Make everything which is typically needed.
3125 Remove most files which were built during make.
3127 @item make distclean
3128 Remove everything which was built during make.
3134 Create documentation in dvi, html, info or pdf format.
3139 @item make defconfig
3140 (Re-)create some build configuration files.
3141 User made changes will be overwritten.
3152 QEMU is a trademark of Fabrice Bellard.
3154 QEMU is released under the GNU General Public License (TODO: add link).
3155 Parts of QEMU have specific licenses, see file LICENSE.
3157 TODO (refer to file LICENSE, include it, include the GPL?)
3171 @section Concept Index
3172 This is the main index. Should we combine all keywords in one index? TODO
3175 @node Function Index
3176 @section Function Index
3177 This index could be used for command line options and monitor functions.
3180 @node Keystroke Index
3181 @section Keystroke Index
3183 This is a list of all keystrokes which have a special function
3184 in system emulation.
3189 @section Program Index
3192 @node Data Type Index
3193 @section Data Type Index
3195 This index could be used for qdev device names and options.
3199 @node Variable Index
3200 @section Variable Index