1 \input texinfo @c -*- texinfo -*-
3 @setfilename qemu-doc.info
6 @documentencoding UTF-8
8 @settitle QEMU Emulator User Documentation
15 * QEMU: (qemu-doc). The QEMU Emulator User Documentation.
22 @center @titlefont{QEMU Emulator}
24 @center @titlefont{User Documentation}
36 * QEMU PC System emulator::
37 * QEMU System emulator for non PC targets::
38 * QEMU User space emulator::
39 * compilation:: Compilation from the sources
51 * intro_features:: Features
57 QEMU is a FAST! processor emulator using dynamic translation to
58 achieve good emulation speed.
60 @cindex operating modes
61 QEMU has two operating modes:
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)
148 @cindex installation (Mac OS X)
150 Download the experimental binary installer at
151 @url{http://www.free.oszoo.org/@/download.html}.
152 TODO (no longer available)
154 @node QEMU PC System emulator
155 @chapter QEMU PC System emulator
156 @cindex system emulation (PC)
159 * pcsys_introduction:: Introduction
160 * pcsys_quickstart:: Quick Start
161 * sec_invocation:: Invocation
163 * pcsys_monitor:: QEMU Monitor
164 * disk_images:: Disk Images
165 * pcsys_network:: Network emulation
166 * pcsys_other_devs:: Other Devices
167 * direct_linux_boot:: Direct Linux Boot
168 * pcsys_usb:: USB emulation
169 * vnc_security:: VNC security
170 * gdb_usage:: GDB usage
171 * pcsys_os_specific:: Target OS specific information
174 @node pcsys_introduction
175 @section Introduction
177 @c man begin DESCRIPTION
179 The QEMU PC System emulator simulates the
180 following peripherals:
184 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
186 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
187 extensions (hardware level, including all non standard modes).
189 PS/2 mouse and keyboard
191 2 PCI IDE interfaces with hard disk and CD-ROM support
195 PCI and ISA network adapters
199 Creative SoundBlaster 16 sound card
201 ENSONIQ AudioPCI ES1370 sound card
203 Intel 82801AA AC97 Audio compatible sound card
205 Intel HD Audio Controller and HDA codec
207 Adlib (OPL2) - Yamaha YM3812 compatible chip
209 Gravis Ultrasound GF1 sound card
211 CS4231A compatible sound card
213 PCI UHCI USB controller and a virtual USB hub.
216 SMP is supported with up to 255 CPUs.
218 QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs LGPL
221 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
223 QEMU uses GUS emulation (GUSEMU32 @url{http://www.deinmeister.de/gusemu/})
224 by Tibor "TS" Schütz.
226 Note that, by default, GUS shares IRQ(7) with parallel ports and so
227 QEMU must be told to not have parallel ports to have working GUS.
230 qemu-system-i386 dos.img -soundhw gus -parallel none
235 qemu-system-i386 dos.img -device gus,irq=5
238 Or some other unclaimed IRQ.
240 CS4231A is the chip used in Windows Sound System and GUSMAX products
244 @node pcsys_quickstart
248 Download and uncompress the linux image (@file{linux.img}) and type:
251 qemu-system-i386 linux.img
254 Linux should boot and give you a prompt.
260 @c man begin SYNOPSIS
261 usage: qemu-system-i386 [options] [@var{disk_image}]
266 @var{disk_image} is a raw hard disk image for IDE hard disk 0. Some
267 targets do not need a disk image.
269 @include qemu-options.texi
278 During the graphical emulation, you can use special key combinations to change
279 modes. The default key mappings are shown below, but if you use @code{-alt-grab}
280 then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use
281 @code{-ctrl-grab} then the modifier is the right Ctrl key (instead of Ctrl-Alt):
298 Restore the screen's un-scaled dimensions
302 Switch to virtual console 'n'. Standard console mappings are:
305 Target system display
314 Toggle mouse and keyboard grab.
320 @kindex Ctrl-PageDown
321 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
322 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
325 During emulation, if you are using the @option{-nographic} option, use
326 @key{Ctrl-a h} to get terminal commands:
339 Save disk data back to file (if -snapshot)
342 Toggle console timestamps
345 Send break (magic sysrq in Linux)
348 Switch between console and monitor
358 The HTML documentation of QEMU for more precise information and Linux
359 user mode emulator invocation.
369 @section QEMU Monitor
372 The QEMU monitor is used to give complex commands to the QEMU
373 emulator. You can use it to:
378 Remove or insert removable media images
379 (such as CD-ROM or floppies).
382 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
385 @item Inspect the VM state without an external debugger.
391 The following commands are available:
393 @include qemu-monitor.texi
395 @subsection Integer expressions
397 The monitor understands integers expressions for every integer
398 argument. You can use register names to get the value of specifics
399 CPU registers by prefixing them with @emph{$}.
404 Since version 0.6.1, QEMU supports many disk image formats, including
405 growable disk images (their size increase as non empty sectors are
406 written), compressed and encrypted disk images. Version 0.8.3 added
407 the new qcow2 disk image format which is essential to support VM
411 * disk_images_quickstart:: Quick start for disk image creation
412 * disk_images_snapshot_mode:: Snapshot mode
413 * vm_snapshots:: VM snapshots
414 * qemu_img_invocation:: qemu-img Invocation
415 * qemu_nbd_invocation:: qemu-nbd Invocation
416 * disk_images_formats:: Disk image file formats
417 * host_drives:: Using host drives
418 * disk_images_fat_images:: Virtual FAT disk images
419 * disk_images_nbd:: NBD access
420 * disk_images_sheepdog:: Sheepdog disk images
421 * disk_images_iscsi:: iSCSI LUNs
422 * disk_images_gluster:: GlusterFS disk images
423 * disk_images_ssh:: Secure Shell (ssh) disk images
426 @node disk_images_quickstart
427 @subsection Quick start for disk image creation
429 You can create a disk image with the command:
431 qemu-img create myimage.img mysize
433 where @var{myimage.img} is the disk image filename and @var{mysize} is its
434 size in kilobytes. You can add an @code{M} suffix to give the size in
435 megabytes and a @code{G} suffix for gigabytes.
437 See @ref{qemu_img_invocation} for more information.
439 @node disk_images_snapshot_mode
440 @subsection Snapshot mode
442 If you use the option @option{-snapshot}, all disk images are
443 considered as read only. When sectors in written, they are written in
444 a temporary file created in @file{/tmp}. You can however force the
445 write back to the raw disk images by using the @code{commit} monitor
446 command (or @key{C-a s} in the serial console).
449 @subsection VM snapshots
451 VM snapshots are snapshots of the complete virtual machine including
452 CPU state, RAM, device state and the content of all the writable
453 disks. In order to use VM snapshots, you must have at least one non
454 removable and writable block device using the @code{qcow2} disk image
455 format. Normally this device is the first virtual hard drive.
457 Use the monitor command @code{savevm} to create a new VM snapshot or
458 replace an existing one. A human readable name can be assigned to each
459 snapshot in addition to its numerical ID.
461 Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
462 a VM snapshot. @code{info snapshots} lists the available snapshots
463 with their associated information:
466 (qemu) info snapshots
467 Snapshot devices: hda
468 Snapshot list (from hda):
469 ID TAG VM SIZE DATE VM CLOCK
470 1 start 41M 2006-08-06 12:38:02 00:00:14.954
471 2 40M 2006-08-06 12:43:29 00:00:18.633
472 3 msys 40M 2006-08-06 12:44:04 00:00:23.514
475 A VM snapshot is made of a VM state info (its size is shown in
476 @code{info snapshots}) and a snapshot of every writable disk image.
477 The VM state info is stored in the first @code{qcow2} non removable
478 and writable block device. The disk image snapshots are stored in
479 every disk image. The size of a snapshot in a disk image is difficult
480 to evaluate and is not shown by @code{info snapshots} because the
481 associated disk sectors are shared among all the snapshots to save
482 disk space (otherwise each snapshot would need a full copy of all the
485 When using the (unrelated) @code{-snapshot} option
486 (@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
487 but they are deleted as soon as you exit QEMU.
489 VM snapshots currently have the following known limitations:
492 They cannot cope with removable devices if they are removed or
493 inserted after a snapshot is done.
495 A few device drivers still have incomplete snapshot support so their
496 state is not saved or restored properly (in particular USB).
499 @node qemu_img_invocation
500 @subsection @code{qemu-img} Invocation
502 @include qemu-img.texi
504 @node qemu_nbd_invocation
505 @subsection @code{qemu-nbd} Invocation
507 @include qemu-nbd.texi
509 @node disk_images_formats
510 @subsection Disk image file formats
512 QEMU supports many image file formats that can be used with VMs as well as with
513 any of the tools (like @code{qemu-img}). This includes the preferred formats
514 raw and qcow2 as well as formats that are supported for compatibility with
515 older QEMU versions or other hypervisors.
517 Depending on the image format, different options can be passed to
518 @code{qemu-img create} and @code{qemu-img convert} using the @code{-o} option.
519 This section describes each format and the options that are supported for it.
524 Raw disk image format. This format has the advantage of
525 being simple and easily exportable to all other emulators. If your
526 file system supports @emph{holes} (for example in ext2 or ext3 on
527 Linux or NTFS on Windows), then only the written sectors will reserve
528 space. Use @code{qemu-img info} to know the real size used by the
529 image or @code{ls -ls} on Unix/Linux.
534 Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}).
535 @code{falloc} mode preallocates space for image by calling posix_fallocate().
536 @code{full} mode preallocates space for image by writing zeros to underlying
541 QEMU image format, the most versatile format. Use it to have smaller
542 images (useful if your filesystem does not supports holes, for example
543 on Windows), zlib based compression and support of multiple VM
549 Determines the qcow2 version to use. @code{compat=0.10} uses the
550 traditional image format that can be read by any QEMU since 0.10.
551 @code{compat=1.1} enables image format extensions that only QEMU 1.1 and
552 newer understand (this is the default). Amongst others, this includes
553 zero clusters, which allow efficient copy-on-read for sparse images.
556 File name of a base image (see @option{create} subcommand)
558 Image format of the base image
560 If this option is set to @code{on}, the image is encrypted with 128-bit AES-CBC.
562 The use of encryption in qcow and qcow2 images is considered to be flawed by
563 modern cryptography standards, suffering from a number of design problems:
566 @item The AES-CBC cipher is used with predictable initialization vectors based
567 on the sector number. This makes it vulnerable to chosen plaintext attacks
568 which can reveal the existence of encrypted data.
569 @item The user passphrase is directly used as the encryption key. A poorly
570 chosen or short passphrase will compromise the security of the encryption.
571 @item In the event of the passphrase being compromised there is no way to
572 change the passphrase to protect data in any qcow images. The files must
573 be cloned, using a different encryption passphrase in the new file. The
574 original file must then be securely erased using a program like shred,
575 though even this is ineffective with many modern storage technologies.
578 Use of qcow / qcow2 encryption with QEMU is deprecated, and support for
579 it will go away in a future release. Users are recommended to use an
580 alternative encryption technology such as the Linux dm-crypt / LUKS
584 Changes the qcow2 cluster size (must be between 512 and 2M). Smaller cluster
585 sizes can improve the image file size whereas larger cluster sizes generally
586 provide better performance.
589 Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
590 @code{full}). An image with preallocated metadata is initially larger but can
591 improve performance when the image needs to grow. @code{falloc} and @code{full}
592 preallocations are like the same options of @code{raw} format, but sets up
596 If this option is set to @code{on}, reference count updates are postponed with
597 the goal of avoiding metadata I/O and improving performance. This is
598 particularly interesting with @option{cache=writethrough} which doesn't batch
599 metadata updates. The tradeoff is that after a host crash, the reference count
600 tables must be rebuilt, i.e. on the next open an (automatic) @code{qemu-img
601 check -r all} is required, which may take some time.
603 This option can only be enabled if @code{compat=1.1} is specified.
606 If this option is set to @code{on}, it will turn off COW of the file. It's only
607 valid on btrfs, no effect on other file systems.
609 Btrfs has low performance when hosting a VM image file, even more when the guest
610 on the VM also using btrfs as file system. Turning off COW is a way to mitigate
611 this bad performance. Generally there are two ways to turn off COW on btrfs:
612 a) Disable it by mounting with nodatacow, then all newly created files will be
613 NOCOW. b) For an empty file, add the NOCOW file attribute. That's what this option
616 Note: this option is only valid to new or empty files. If there is an existing
617 file which is COW and has data blocks already, it couldn't be changed to NOCOW
618 by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if
619 the NOCOW flag is set or not (Capital 'C' is NOCOW flag).
624 Old QEMU image format with support for backing files and compact image files
625 (when your filesystem or transport medium does not support holes).
627 When converting QED images to qcow2, you might want to consider using the
628 @code{lazy_refcounts=on} option to get a more QED-like behaviour.
633 File name of a base image (see @option{create} subcommand).
635 Image file format of backing file (optional). Useful if the format cannot be
636 autodetected because it has no header, like some vhd/vpc files.
638 Changes the cluster size (must be power-of-2 between 4K and 64K). Smaller
639 cluster sizes can improve the image file size whereas larger cluster sizes
640 generally provide better performance.
642 Changes the number of clusters per L1/L2 table (must be power-of-2 between 1
643 and 16). There is normally no need to change this value but this option can be
644 used for performance benchmarking.
648 Old QEMU image format with support for backing files, compact image files,
649 encryption and compression.
654 File name of a base image (see @option{create} subcommand)
656 If this option is set to @code{on}, the image is encrypted.
660 VirtualBox 1.1 compatible image format.
664 If this option is set to @code{on}, the image is created with metadata
669 VMware 3 and 4 compatible image format.
674 File name of a base image (see @option{create} subcommand).
676 Create a VMDK version 6 image (instead of version 4)
678 Specifies which VMDK subformat to use. Valid options are
679 @code{monolithicSparse} (default),
680 @code{monolithicFlat},
681 @code{twoGbMaxExtentSparse},
682 @code{twoGbMaxExtentFlat} and
683 @code{streamOptimized}.
687 VirtualPC compatible image format (VHD).
691 Specifies which VHD subformat to use. Valid options are
692 @code{dynamic} (default) and @code{fixed}.
696 Hyper-V compatible image format (VHDX).
700 Specifies which VHDX subformat to use. Valid options are
701 @code{dynamic} (default) and @code{fixed}.
702 @item block_state_zero
703 Force use of payload blocks of type 'ZERO'. Can be set to @code{on} (default)
704 or @code{off}. When set to @code{off}, new blocks will be created as
705 @code{PAYLOAD_BLOCK_NOT_PRESENT}, which means parsers are free to return
706 arbitrary data for those blocks. Do not set to @code{off} when using
707 @code{qemu-img convert} with @code{subformat=dynamic}.
709 Block size; min 1 MB, max 256 MB. 0 means auto-calculate based on image size.
715 @subsubsection Read-only formats
716 More disk image file formats are supported in a read-only mode.
719 Bochs images of @code{growing} type.
721 Linux Compressed Loop image, useful only to reuse directly compressed
722 CD-ROM images present for example in the Knoppix CD-ROMs.
726 Parallels disk image format.
731 @subsection Using host drives
733 In addition to disk image files, QEMU can directly access host
734 devices. We describe here the usage for QEMU version >= 0.8.3.
738 On Linux, you can directly use the host device filename instead of a
739 disk image filename provided you have enough privileges to access
740 it. For example, use @file{/dev/cdrom} to access to the CDROM.
744 You can specify a CDROM device even if no CDROM is loaded. QEMU has
745 specific code to detect CDROM insertion or removal. CDROM ejection by
746 the guest OS is supported. Currently only data CDs are supported.
748 You can specify a floppy device even if no floppy is loaded. Floppy
749 removal is currently not detected accurately (if you change floppy
750 without doing floppy access while the floppy is not loaded, the guest
751 OS will think that the same floppy is loaded).
752 Use of the host's floppy device is deprecated, and support for it will
753 be removed in a future release.
755 Hard disks can be used. Normally you must specify the whole disk
756 (@file{/dev/hdb} instead of @file{/dev/hdb1}) so that the guest OS can
757 see it as a partitioned disk. WARNING: unless you know what you do, it
758 is better to only make READ-ONLY accesses to the hard disk otherwise
759 you may corrupt your host data (use the @option{-snapshot} command
760 line option or modify the device permissions accordingly).
763 @subsubsection Windows
767 The preferred syntax is the drive letter (e.g. @file{d:}). The
768 alternate syntax @file{\\.\d:} is supported. @file{/dev/cdrom} is
769 supported as an alias to the first CDROM drive.
771 Currently there is no specific code to handle removable media, so it
772 is better to use the @code{change} or @code{eject} monitor commands to
773 change or eject media.
775 Hard disks can be used with the syntax: @file{\\.\PhysicalDrive@var{N}}
776 where @var{N} is the drive number (0 is the first hard disk).
777 @file{/dev/hda} is supported as an alias to
778 the first hard disk drive @file{\\.\PhysicalDrive0}.
780 WARNING: unless you know what you do, it is better to only make
781 READ-ONLY accesses to the hard disk otherwise you may corrupt your
782 host data (use the @option{-snapshot} command line so that the
783 modifications are written in a temporary file).
787 @subsubsection Mac OS X
789 @file{/dev/cdrom} is an alias to the first CDROM.
791 Currently there is no specific code to handle removable media, so it
792 is better to use the @code{change} or @code{eject} monitor commands to
793 change or eject media.
795 @node disk_images_fat_images
796 @subsection Virtual FAT disk images
798 QEMU can automatically create a virtual FAT disk image from a
799 directory tree. In order to use it, just type:
802 qemu-system-i386 linux.img -hdb fat:/my_directory
805 Then you access access to all the files in the @file{/my_directory}
806 directory without having to copy them in a disk image or to export
807 them via SAMBA or NFS. The default access is @emph{read-only}.
809 Floppies can be emulated with the @code{:floppy:} option:
812 qemu-system-i386 linux.img -fda fat:floppy:/my_directory
815 A read/write support is available for testing (beta stage) with the
819 qemu-system-i386 linux.img -fda fat:floppy:rw:/my_directory
822 What you should @emph{never} do:
824 @item use non-ASCII filenames ;
825 @item use "-snapshot" together with ":rw:" ;
826 @item expect it to work when loadvm'ing ;
827 @item write to the FAT directory on the host system while accessing it with the guest system.
830 @node disk_images_nbd
831 @subsection NBD access
833 QEMU can access directly to block device exported using the Network Block Device
837 qemu-system-i386 linux.img -hdb nbd://my_nbd_server.mydomain.org:1024/
840 If the NBD server is located on the same host, you can use an unix socket instead
844 qemu-system-i386 linux.img -hdb nbd+unix://?socket=/tmp/my_socket
847 In this case, the block device must be exported using qemu-nbd:
850 qemu-nbd --socket=/tmp/my_socket my_disk.qcow2
853 The use of qemu-nbd allows sharing of a disk between several guests:
855 qemu-nbd --socket=/tmp/my_socket --share=2 my_disk.qcow2
859 and then you can use it with two guests:
861 qemu-system-i386 linux1.img -hdb nbd+unix://?socket=/tmp/my_socket
862 qemu-system-i386 linux2.img -hdb nbd+unix://?socket=/tmp/my_socket
865 If the nbd-server uses named exports (supported since NBD 2.9.18, or with QEMU's
866 own embedded NBD server), you must specify an export name in the URI:
868 qemu-system-i386 -cdrom nbd://localhost/debian-500-ppc-netinst
869 qemu-system-i386 -cdrom nbd://localhost/openSUSE-11.1-ppc-netinst
872 The URI syntax for NBD is supported since QEMU 1.3. An alternative syntax is
873 also available. Here are some example of the older syntax:
875 qemu-system-i386 linux.img -hdb nbd:my_nbd_server.mydomain.org:1024
876 qemu-system-i386 linux2.img -hdb nbd:unix:/tmp/my_socket
877 qemu-system-i386 -cdrom nbd:localhost:10809:exportname=debian-500-ppc-netinst
880 @node disk_images_sheepdog
881 @subsection Sheepdog disk images
883 Sheepdog is a distributed storage system for QEMU. It provides highly
884 available block level storage volumes that can be attached to
885 QEMU-based virtual machines.
887 You can create a Sheepdog disk image with the command:
889 qemu-img create sheepdog:///@var{image} @var{size}
891 where @var{image} is the Sheepdog image name and @var{size} is its
894 To import the existing @var{filename} to Sheepdog, you can use a
897 qemu-img convert @var{filename} sheepdog:///@var{image}
900 You can boot from the Sheepdog disk image with the command:
902 qemu-system-i386 sheepdog:///@var{image}
905 You can also create a snapshot of the Sheepdog image like qcow2.
907 qemu-img snapshot -c @var{tag} sheepdog:///@var{image}
909 where @var{tag} is a tag name of the newly created snapshot.
911 To boot from the Sheepdog snapshot, specify the tag name of the
914 qemu-system-i386 sheepdog:///@var{image}#@var{tag}
917 You can create a cloned image from the existing snapshot.
919 qemu-img create -b sheepdog:///@var{base}#@var{tag} sheepdog:///@var{image}
921 where @var{base} is a image name of the source snapshot and @var{tag}
924 You can use an unix socket instead of an inet socket:
927 qemu-system-i386 sheepdog+unix:///@var{image}?socket=@var{path}
930 If the Sheepdog daemon doesn't run on the local host, you need to
931 specify one of the Sheepdog servers to connect to.
933 qemu-img create sheepdog://@var{hostname}:@var{port}/@var{image} @var{size}
934 qemu-system-i386 sheepdog://@var{hostname}:@var{port}/@var{image}
937 @node disk_images_iscsi
938 @subsection iSCSI LUNs
940 iSCSI is a popular protocol used to access SCSI devices across a computer
943 There are two different ways iSCSI devices can be used by QEMU.
945 The first method is to mount the iSCSI LUN on the host, and make it appear as
946 any other ordinary SCSI device on the host and then to access this device as a
947 /dev/sd device from QEMU. How to do this differs between host OSes.
949 The second method involves using the iSCSI initiator that is built into
950 QEMU. This provides a mechanism that works the same way regardless of which
951 host OS you are running QEMU on. This section will describe this second method
952 of using iSCSI together with QEMU.
954 In QEMU, iSCSI devices are described using special iSCSI URLs
958 iscsi://[<username>[%<password>]@@]<host>[:<port>]/<target-iqn-name>/<lun>
961 Username and password are optional and only used if your target is set up
962 using CHAP authentication for access control.
963 Alternatively the username and password can also be set via environment
964 variables to have these not show up in the process list
967 export LIBISCSI_CHAP_USERNAME=<username>
968 export LIBISCSI_CHAP_PASSWORD=<password>
969 iscsi://<host>/<target-iqn-name>/<lun>
972 Various session related parameters can be set via special options, either
973 in a configuration file provided via '-readconfig' or directly on the
976 If the initiator-name is not specified qemu will use a default name
977 of 'iqn.2008-11.org.linux-kvm[:<name>'] where <name> is the name of the
982 Setting a specific initiator name to use when logging in to the target
983 -iscsi initiator-name=iqn.qemu.test:my-initiator
987 Controlling which type of header digest to negotiate with the target
988 -iscsi header-digest=CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
991 These can also be set via a configuration file
994 user = "CHAP username"
995 password = "CHAP password"
996 initiator-name = "iqn.qemu.test:my-initiator"
997 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
998 header-digest = "CRC32C"
1002 Setting the target name allows different options for different targets
1004 [iscsi "iqn.target.name"]
1005 user = "CHAP username"
1006 password = "CHAP password"
1007 initiator-name = "iqn.qemu.test:my-initiator"
1008 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1009 header-digest = "CRC32C"
1013 Howto use a configuration file to set iSCSI configuration options:
1015 cat >iscsi.conf <<EOF
1018 password = "my password"
1019 initiator-name = "iqn.qemu.test:my-initiator"
1020 header-digest = "CRC32C"
1023 qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1024 -readconfig iscsi.conf
1028 Howto set up a simple iSCSI target on loopback and accessing it via QEMU:
1030 This example shows how to set up an iSCSI target with one CDROM and one DISK
1031 using the Linux STGT software target. This target is available on Red Hat based
1032 systems as the package 'scsi-target-utils'.
1034 tgtd --iscsi portal=127.0.0.1:3260
1035 tgtadm --lld iscsi --op new --mode target --tid 1 -T iqn.qemu.test
1036 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 \
1037 -b /IMAGES/disk.img --device-type=disk
1038 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 \
1039 -b /IMAGES/cd.iso --device-type=cd
1040 tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL
1042 qemu-system-i386 -iscsi initiator-name=iqn.qemu.test:my-initiator \
1043 -boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1044 -cdrom iscsi://127.0.0.1/iqn.qemu.test/2
1047 @node disk_images_gluster
1048 @subsection GlusterFS disk images
1050 GlusterFS is an user space distributed file system.
1052 You can boot from the GlusterFS disk image with the command:
1054 qemu-system-x86_64 -drive file=gluster[+@var{transport}]://[@var{server}[:@var{port}]]/@var{volname}/@var{image}[?socket=...]
1057 @var{gluster} is the protocol.
1059 @var{transport} specifies the transport type used to connect to gluster
1060 management daemon (glusterd). Valid transport types are
1061 tcp, unix and rdma. If a transport type isn't specified, then tcp
1064 @var{server} specifies the server where the volume file specification for
1065 the given volume resides. This can be either hostname, ipv4 address
1066 or ipv6 address. ipv6 address needs to be within square brackets [ ].
1067 If transport type is unix, then @var{server} field should not be specified.
1068 Instead @var{socket} field needs to be populated with the path to unix domain
1071 @var{port} is the port number on which glusterd is listening. This is optional
1072 and if not specified, QEMU will send 0 which will make gluster to use the
1073 default port. If the transport type is unix, then @var{port} should not be
1076 @var{volname} is the name of the gluster volume which contains the disk image.
1078 @var{image} is the path to the actual disk image that resides on gluster volume.
1080 You can create a GlusterFS disk image with the command:
1082 qemu-img create gluster://@var{server}/@var{volname}/@var{image} @var{size}
1087 qemu-system-x86_64 -drive file=gluster://1.2.3.4/testvol/a.img
1088 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4/testvol/a.img
1089 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img
1090 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
1091 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img
1092 qemu-system-x86_64 -drive file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img
1093 qemu-system-x86_64 -drive file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
1094 qemu-system-x86_64 -drive file=gluster+rdma://1.2.3.4:24007/testvol/a.img
1097 @node disk_images_ssh
1098 @subsection Secure Shell (ssh) disk images
1100 You can access disk images located on a remote ssh server
1101 by using the ssh protocol:
1104 qemu-system-x86_64 -drive file=ssh://[@var{user}@@]@var{server}[:@var{port}]/@var{path}[?host_key_check=@var{host_key_check}]
1107 Alternative syntax using properties:
1110 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}]
1113 @var{ssh} is the protocol.
1115 @var{user} is the remote user. If not specified, then the local
1118 @var{server} specifies the remote ssh server. Any ssh server can be
1119 used, but it must implement the sftp-server protocol. Most Unix/Linux
1120 systems should work without requiring any extra configuration.
1122 @var{port} is the port number on which sshd is listening. By default
1123 the standard ssh port (22) is used.
1125 @var{path} is the path to the disk image.
1127 The optional @var{host_key_check} parameter controls how the remote
1128 host's key is checked. The default is @code{yes} which means to use
1129 the local @file{.ssh/known_hosts} file. Setting this to @code{no}
1130 turns off known-hosts checking. Or you can check that the host key
1131 matches a specific fingerprint:
1132 @code{host_key_check=md5:78:45:8e:14:57:4f:d5:45:83:0a:0e:f3:49:82:c9:c8}
1133 (@code{sha1:} can also be used as a prefix, but note that OpenSSH
1134 tools only use MD5 to print fingerprints).
1136 Currently authentication must be done using ssh-agent. Other
1137 authentication methods may be supported in future.
1139 Note: Many ssh servers do not support an @code{fsync}-style operation.
1140 The ssh driver cannot guarantee that disk flush requests are
1141 obeyed, and this causes a risk of disk corruption if the remote
1142 server or network goes down during writes. The driver will
1143 print a warning when @code{fsync} is not supported:
1145 warning: ssh server @code{ssh.example.com:22} does not support fsync
1147 With sufficiently new versions of libssh2 and OpenSSH, @code{fsync} is
1151 @section Network emulation
1153 QEMU can simulate several network cards (PCI or ISA cards on the PC
1154 target) and can connect them to an arbitrary number of Virtual Local
1155 Area Networks (VLANs). Host TAP devices can be connected to any QEMU
1156 VLAN. VLAN can be connected between separate instances of QEMU to
1157 simulate large networks. For simpler usage, a non privileged user mode
1158 network stack can replace the TAP device to have a basic network
1163 QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
1164 connection between several network devices. These devices can be for
1165 example QEMU virtual Ethernet cards or virtual Host ethernet devices
1168 @subsection Using TAP network interfaces
1170 This is the standard way to connect QEMU to a real network. QEMU adds
1171 a virtual network device on your host (called @code{tapN}), and you
1172 can then configure it as if it was a real ethernet card.
1174 @subsubsection Linux host
1176 As an example, you can download the @file{linux-test-xxx.tar.gz}
1177 archive and copy the script @file{qemu-ifup} in @file{/etc} and
1178 configure properly @code{sudo} so that the command @code{ifconfig}
1179 contained in @file{qemu-ifup} can be executed as root. You must verify
1180 that your host kernel supports the TAP network interfaces: the
1181 device @file{/dev/net/tun} must be present.
1183 See @ref{sec_invocation} to have examples of command lines using the
1184 TAP network interfaces.
1186 @subsubsection Windows host
1188 There is a virtual ethernet driver for Windows 2000/XP systems, called
1189 TAP-Win32. But it is not included in standard QEMU for Windows,
1190 so you will need to get it separately. It is part of OpenVPN package,
1191 so download OpenVPN from : @url{http://openvpn.net/}.
1193 @subsection Using the user mode network stack
1195 By using the option @option{-net user} (default configuration if no
1196 @option{-net} option is specified), QEMU uses a completely user mode
1197 network stack (you don't need root privilege to use the virtual
1198 network). The virtual network configuration is the following:
1202 QEMU VLAN <------> Firewall/DHCP server <-----> Internet
1205 ----> DNS server (10.0.2.3)
1207 ----> SMB server (10.0.2.4)
1210 The QEMU VM behaves as if it was behind a firewall which blocks all
1211 incoming connections. You can use a DHCP client to automatically
1212 configure the network in the QEMU VM. The DHCP server assign addresses
1213 to the hosts starting from 10.0.2.15.
1215 In order to check that the user mode network is working, you can ping
1216 the address 10.0.2.2 and verify that you got an address in the range
1217 10.0.2.x from the QEMU virtual DHCP server.
1219 Note that ICMP traffic in general does not work with user mode networking.
1220 @code{ping}, aka. ICMP echo, to the local router (10.0.2.2) shall work,
1221 however. If you're using QEMU on Linux >= 3.0, it can use unprivileged ICMP
1222 ping sockets to allow @code{ping} to the Internet. The host admin has to set
1223 the ping_group_range in order to grant access to those sockets. To allow ping
1224 for GID 100 (usually users group):
1227 echo 100 100 > /proc/sys/net/ipv4/ping_group_range
1230 When using the built-in TFTP server, the router is also the TFTP
1233 When using the @option{-redir} option, TCP or UDP connections can be
1234 redirected from the host to the guest. It allows for example to
1235 redirect X11, telnet or SSH connections.
1237 @subsection Connecting VLANs between QEMU instances
1239 Using the @option{-net socket} option, it is possible to make VLANs
1240 that span several QEMU instances. See @ref{sec_invocation} to have a
1243 @node pcsys_other_devs
1244 @section Other Devices
1246 @subsection Inter-VM Shared Memory device
1248 With KVM enabled on a Linux host, a shared memory device is available. Guests
1249 map a POSIX shared memory region into the guest as a PCI device that enables
1250 zero-copy communication to the application level of the guests. The basic
1254 qemu-system-i386 -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>]
1257 If desired, interrupts can be sent between guest VMs accessing the same shared
1258 memory region. Interrupt support requires using a shared memory server and
1259 using a chardev socket to connect to it. The code for the shared memory server
1260 is qemu.git/contrib/ivshmem-server. An example syntax when using the shared
1264 qemu-system-i386 -device ivshmem,size=<size in format accepted by -m>[,chardev=<id>]
1265 [,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master]
1266 qemu-system-i386 -chardev socket,path=<path>,id=<id>
1269 When using the server, the guest will be assigned a VM ID (>=0) that allows guests
1270 using the same server to communicate via interrupts. Guests can read their
1271 VM ID from a device register (see example code). Since receiving the shared
1272 memory region from the server is asynchronous, there is a (small) chance the
1273 guest may boot before the shared memory is attached. To allow an application
1274 to ensure shared memory is attached, the VM ID register will return -1 (an
1275 invalid VM ID) until the memory is attached. Once the shared memory is
1276 attached, the VM ID will return the guest's valid VM ID. With these semantics,
1277 the guest application can check to ensure the shared memory is attached to the
1278 guest before proceeding.
1280 The @option{role} argument can be set to either master or peer and will affect
1281 how the shared memory is migrated. With @option{role=master}, the guest will
1282 copy the shared memory on migration to the destination host. With
1283 @option{role=peer}, the guest will not be able to migrate with the device attached.
1284 With the @option{peer} case, the device should be detached and then reattached
1285 after migration using the PCI hotplug support.
1287 @node direct_linux_boot
1288 @section Direct Linux Boot
1290 This section explains how to launch a Linux kernel inside QEMU without
1291 having to make a full bootable image. It is very useful for fast Linux
1296 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
1299 Use @option{-kernel} to provide the Linux kernel image and
1300 @option{-append} to give the kernel command line arguments. The
1301 @option{-initrd} option can be used to provide an INITRD image.
1303 When using the direct Linux boot, a disk image for the first hard disk
1304 @file{hda} is required because its boot sector is used to launch the
1307 If you do not need graphical output, you can disable it and redirect
1308 the virtual serial port and the QEMU monitor to the console with the
1309 @option{-nographic} option. The typical command line is:
1311 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1312 -append "root=/dev/hda console=ttyS0" -nographic
1315 Use @key{Ctrl-a c} to switch between the serial console and the
1316 monitor (@pxref{pcsys_keys}).
1319 @section USB emulation
1321 QEMU emulates a PCI UHCI USB controller. You can virtually plug
1322 virtual USB devices or real host USB devices (experimental, works only
1323 on Linux hosts). QEMU will automatically create and connect virtual USB hubs
1324 as necessary to connect multiple USB devices.
1328 * host_usb_devices::
1331 @subsection Connecting USB devices
1333 USB devices can be connected with the @option{-usbdevice} commandline option
1334 or the @code{usb_add} monitor command. Available devices are:
1338 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1340 Pointer device that uses absolute coordinates (like a touchscreen).
1341 This means QEMU is able to report the mouse position without having
1342 to grab the mouse. Also overrides the PS/2 mouse emulation when activated.
1343 @item disk:@var{file}
1344 Mass storage device based on @var{file} (@pxref{disk_images})
1345 @item host:@var{bus.addr}
1346 Pass through the host device identified by @var{bus.addr}
1348 @item host:@var{vendor_id:product_id}
1349 Pass through the host device identified by @var{vendor_id:product_id}
1352 Virtual Wacom PenPartner tablet. This device is similar to the @code{tablet}
1353 above but it can be used with the tslib library because in addition to touch
1354 coordinates it reports touch pressure.
1356 Standard USB keyboard. Will override the PS/2 keyboard (if present).
1357 @item serial:[vendorid=@var{vendor_id}][,product_id=@var{product_id}]:@var{dev}
1358 Serial converter. This emulates an FTDI FT232BM chip connected to host character
1359 device @var{dev}. The available character devices are the same as for the
1360 @code{-serial} option. The @code{vendorid} and @code{productid} options can be
1361 used to override the default 0403:6001. For instance,
1363 usb_add serial:productid=FA00:tcp:192.168.0.2:4444
1365 will connect to tcp port 4444 of ip 192.168.0.2, and plug that to the virtual
1366 serial converter, faking a Matrix Orbital LCD Display (USB ID 0403:FA00).
1368 Braille device. This will use BrlAPI to display the braille output on a real
1370 @item net:@var{options}
1371 Network adapter that supports CDC ethernet and RNDIS protocols. @var{options}
1372 specifies NIC options as with @code{-net nic,}@var{options} (see description).
1373 For instance, user-mode networking can be used with
1375 qemu-system-i386 [...OPTIONS...] -net user,vlan=0 -usbdevice net:vlan=0
1377 Currently this cannot be used in machines that support PCI NICs.
1378 @item bt[:@var{hci-type}]
1379 Bluetooth dongle whose type is specified in the same format as with
1380 the @option{-bt hci} option, @pxref{bt-hcis,,allowed HCI types}. If
1381 no type is given, the HCI logic corresponds to @code{-bt hci,vlan=0}.
1382 This USB device implements the USB Transport Layer of HCI. Example
1385 qemu-system-i386 [...OPTIONS...] -usbdevice bt:hci,vlan=3 -bt device:keyboard,vlan=3
1389 @node host_usb_devices
1390 @subsection Using host USB devices on a Linux host
1392 WARNING: this is an experimental feature. QEMU will slow down when
1393 using it. USB devices requiring real time streaming (i.e. USB Video
1394 Cameras) are not supported yet.
1397 @item If you use an early Linux 2.4 kernel, verify that no Linux driver
1398 is actually using the USB device. A simple way to do that is simply to
1399 disable the corresponding kernel module by renaming it from @file{mydriver.o}
1400 to @file{mydriver.o.disabled}.
1402 @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1408 @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:
1410 chown -R myuid /proc/bus/usb
1413 @item Launch QEMU and do in the monitor:
1416 Device 1.2, speed 480 Mb/s
1417 Class 00: USB device 1234:5678, USB DISK
1419 You should see the list of the devices you can use (Never try to use
1420 hubs, it won't work).
1422 @item Add the device in QEMU by using:
1424 usb_add host:1234:5678
1427 Normally the guest OS should report that a new USB device is
1428 plugged. You can use the option @option{-usbdevice} to do the same.
1430 @item Now you can try to use the host USB device in QEMU.
1434 When relaunching QEMU, you may have to unplug and plug again the USB
1435 device to make it work again (this is a bug).
1438 @section VNC security
1440 The VNC server capability provides access to the graphical console
1441 of the guest VM across the network. This has a number of security
1442 considerations depending on the deployment scenarios.
1446 * vnc_sec_password::
1447 * vnc_sec_certificate::
1448 * vnc_sec_certificate_verify::
1449 * vnc_sec_certificate_pw::
1451 * vnc_sec_certificate_sasl::
1452 * vnc_generate_cert::
1456 @subsection Without passwords
1458 The simplest VNC server setup does not include any form of authentication.
1459 For this setup it is recommended to restrict it to listen on a UNIX domain
1460 socket only. For example
1463 qemu-system-i386 [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
1466 This ensures that only users on local box with read/write access to that
1467 path can access the VNC server. To securely access the VNC server from a
1468 remote machine, a combination of netcat+ssh can be used to provide a secure
1471 @node vnc_sec_password
1472 @subsection With passwords
1474 The VNC protocol has limited support for password based authentication. Since
1475 the protocol limits passwords to 8 characters it should not be considered
1476 to provide high security. The password can be fairly easily brute-forced by
1477 a client making repeat connections. For this reason, a VNC server using password
1478 authentication should be restricted to only listen on the loopback interface
1479 or UNIX domain sockets. Password authentication is not supported when operating
1480 in FIPS 140-2 compliance mode as it requires the use of the DES cipher. Password
1481 authentication is requested with the @code{password} option, and then once QEMU
1482 is running the password is set with the monitor. Until the monitor is used to
1483 set the password all clients will be rejected.
1486 qemu-system-i386 [...OPTIONS...] -vnc :1,password -monitor stdio
1487 (qemu) change vnc password
1492 @node vnc_sec_certificate
1493 @subsection With x509 certificates
1495 The QEMU VNC server also implements the VeNCrypt extension allowing use of
1496 TLS for encryption of the session, and x509 certificates for authentication.
1497 The use of x509 certificates is strongly recommended, because TLS on its
1498 own is susceptible to man-in-the-middle attacks. Basic x509 certificate
1499 support provides a secure session, but no authentication. This allows any
1500 client to connect, and provides an encrypted session.
1503 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio
1506 In the above example @code{/etc/pki/qemu} should contain at least three files,
1507 @code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged
1508 users will want to use a private directory, for example @code{$HOME/.pki/qemu}.
1509 NB the @code{server-key.pem} file should be protected with file mode 0600 to
1510 only be readable by the user owning it.
1512 @node vnc_sec_certificate_verify
1513 @subsection With x509 certificates and client verification
1515 Certificates can also provide a means to authenticate the client connecting.
1516 The server will request that the client provide a certificate, which it will
1517 then validate against the CA certificate. This is a good choice if deploying
1518 in an environment with a private internal certificate authority.
1521 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
1525 @node vnc_sec_certificate_pw
1526 @subsection With x509 certificates, client verification and passwords
1528 Finally, the previous method can be combined with VNC password authentication
1529 to provide two layers of authentication for clients.
1532 qemu-system-i386 [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
1533 (qemu) change vnc password
1540 @subsection With SASL authentication
1542 The SASL authentication method is a VNC extension, that provides an
1543 easily extendable, pluggable authentication method. This allows for
1544 integration with a wide range of authentication mechanisms, such as
1545 PAM, GSSAPI/Kerberos, LDAP, SQL databases, one-time keys and more.
1546 The strength of the authentication depends on the exact mechanism
1547 configured. If the chosen mechanism also provides a SSF layer, then
1548 it will encrypt the datastream as well.
1550 Refer to the later docs on how to choose the exact SASL mechanism
1551 used for authentication, but assuming use of one supporting SSF,
1552 then QEMU can be launched with:
1555 qemu-system-i386 [...OPTIONS...] -vnc :1,sasl -monitor stdio
1558 @node vnc_sec_certificate_sasl
1559 @subsection With x509 certificates and SASL authentication
1561 If the desired SASL authentication mechanism does not supported
1562 SSF layers, then it is strongly advised to run it in combination
1563 with TLS and x509 certificates. This provides securely encrypted
1564 data stream, avoiding risk of compromising of the security
1565 credentials. This can be enabled, by combining the 'sasl' option
1566 with the aforementioned TLS + x509 options:
1569 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509,sasl -monitor stdio
1573 @node vnc_generate_cert
1574 @subsection Generating certificates for VNC
1576 The GNU TLS packages provides a command called @code{certtool} which can
1577 be used to generate certificates and keys in PEM format. At a minimum it
1578 is necessary to setup a certificate authority, and issue certificates to
1579 each server. If using certificates for authentication, then each client
1580 will also need to be issued a certificate. The recommendation is for the
1581 server to keep its certificates in either @code{/etc/pki/qemu} or for
1582 unprivileged users in @code{$HOME/.pki/qemu}.
1586 * vnc_generate_server::
1587 * vnc_generate_client::
1589 @node vnc_generate_ca
1590 @subsubsection Setup the Certificate Authority
1592 This step only needs to be performed once per organization / organizational
1593 unit. First the CA needs a private key. This key must be kept VERY secret
1594 and secure. If this key is compromised the entire trust chain of the certificates
1595 issued with it is lost.
1598 # certtool --generate-privkey > ca-key.pem
1601 A CA needs to have a public certificate. For simplicity it can be a self-signed
1602 certificate, or one issue by a commercial certificate issuing authority. To
1603 generate a self-signed certificate requires one core piece of information, the
1604 name of the organization.
1607 # cat > ca.info <<EOF
1608 cn = Name of your organization
1612 # certtool --generate-self-signed \
1613 --load-privkey ca-key.pem
1614 --template ca.info \
1615 --outfile ca-cert.pem
1618 The @code{ca-cert.pem} file should be copied to all servers and clients wishing to utilize
1619 TLS support in the VNC server. The @code{ca-key.pem} must not be disclosed/copied at all.
1621 @node vnc_generate_server
1622 @subsubsection Issuing server certificates
1624 Each server (or host) needs to be issued with a key and certificate. When connecting
1625 the certificate is sent to the client which validates it against the CA certificate.
1626 The core piece of information for a server certificate is the hostname. This should
1627 be the fully qualified hostname that the client will connect with, since the client
1628 will typically also verify the hostname in the certificate. On the host holding the
1629 secure CA private key:
1632 # cat > server.info <<EOF
1633 organization = Name of your organization
1634 cn = server.foo.example.com
1639 # certtool --generate-privkey > server-key.pem
1640 # certtool --generate-certificate \
1641 --load-ca-certificate ca-cert.pem \
1642 --load-ca-privkey ca-key.pem \
1643 --load-privkey server-key.pem \
1644 --template server.info \
1645 --outfile server-cert.pem
1648 The @code{server-key.pem} and @code{server-cert.pem} files should now be securely copied
1649 to the server for which they were generated. The @code{server-key.pem} is security
1650 sensitive and should be kept protected with file mode 0600 to prevent disclosure.
1652 @node vnc_generate_client
1653 @subsubsection Issuing client certificates
1655 If the QEMU VNC server is to use the @code{x509verify} option to validate client
1656 certificates as its authentication mechanism, each client also needs to be issued
1657 a certificate. The client certificate contains enough metadata to uniquely identify
1658 the client, typically organization, state, city, building, etc. On the host holding
1659 the secure CA private key:
1662 # cat > client.info <<EOF
1666 organization = Name of your organization
1667 cn = client.foo.example.com
1672 # certtool --generate-privkey > client-key.pem
1673 # certtool --generate-certificate \
1674 --load-ca-certificate ca-cert.pem \
1675 --load-ca-privkey ca-key.pem \
1676 --load-privkey client-key.pem \
1677 --template client.info \
1678 --outfile client-cert.pem
1681 The @code{client-key.pem} and @code{client-cert.pem} files should now be securely
1682 copied to the client for which they were generated.
1685 @node vnc_setup_sasl
1687 @subsection Configuring SASL mechanisms
1689 The following documentation assumes use of the Cyrus SASL implementation on a
1690 Linux host, but the principals should apply to any other SASL impl. When SASL
1691 is enabled, the mechanism configuration will be loaded from system default
1692 SASL service config /etc/sasl2/qemu.conf. If running QEMU as an
1693 unprivileged user, an environment variable SASL_CONF_PATH can be used
1694 to make it search alternate locations for the service config.
1696 The default configuration might contain
1699 mech_list: digest-md5
1700 sasldb_path: /etc/qemu/passwd.db
1703 This says to use the 'Digest MD5' mechanism, which is similar to the HTTP
1704 Digest-MD5 mechanism. The list of valid usernames & passwords is maintained
1705 in the /etc/qemu/passwd.db file, and can be updated using the saslpasswd2
1706 command. While this mechanism is easy to configure and use, it is not
1707 considered secure by modern standards, so only suitable for developers /
1710 A more serious deployment might use Kerberos, which is done with the 'gssapi'
1715 keytab: /etc/qemu/krb5.tab
1718 For this to work the administrator of your KDC must generate a Kerberos
1719 principal for the server, with a name of 'qemu/somehost.example.com@@EXAMPLE.COM'
1720 replacing 'somehost.example.com' with the fully qualified host name of the
1721 machine running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.
1723 Other configurations will be left as an exercise for the reader. It should
1724 be noted that only Digest-MD5 and GSSAPI provides a SSF layer for data
1725 encryption. For all other mechanisms, VNC should always be configured to
1726 use TLS and x509 certificates to protect security credentials from snooping.
1731 QEMU has a primitive support to work with gdb, so that you can do
1732 'Ctrl-C' while the virtual machine is running and inspect its state.
1734 In order to use gdb, launch QEMU with the '-s' option. It will wait for a
1737 qemu-system-i386 -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1738 -append "root=/dev/hda"
1739 Connected to host network interface: tun0
1740 Waiting gdb connection on port 1234
1743 Then launch gdb on the 'vmlinux' executable:
1748 In gdb, connect to QEMU:
1750 (gdb) target remote localhost:1234
1753 Then you can use gdb normally. For example, type 'c' to launch the kernel:
1758 Here are some useful tips in order to use gdb on system code:
1762 Use @code{info reg} to display all the CPU registers.
1764 Use @code{x/10i $eip} to display the code at the PC position.
1766 Use @code{set architecture i8086} to dump 16 bit code. Then use
1767 @code{x/10i $cs*16+$eip} to dump the code at the PC position.
1770 Advanced debugging options:
1772 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 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:
1774 @item maintenance packet qqemu.sstepbits
1776 This will display the MASK bits used to control the single stepping IE:
1778 (gdb) maintenance packet qqemu.sstepbits
1779 sending: "qqemu.sstepbits"
1780 received: "ENABLE=1,NOIRQ=2,NOTIMER=4"
1782 @item maintenance packet qqemu.sstep
1784 This will display the current value of the mask used when single stepping IE:
1786 (gdb) maintenance packet qqemu.sstep
1787 sending: "qqemu.sstep"
1790 @item maintenance packet Qqemu.sstep=HEX_VALUE
1792 This will change the single step mask, so if wanted to enable IRQs on the single step, but not timers, you would use:
1794 (gdb) maintenance packet Qqemu.sstep=0x5
1795 sending: "qemu.sstep=0x5"
1800 @node pcsys_os_specific
1801 @section Target OS specific information
1805 To have access to SVGA graphic modes under X11, use the @code{vesa} or
1806 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1807 color depth in the guest and the host OS.
1809 When using a 2.6 guest Linux kernel, you should add the option
1810 @code{clock=pit} on the kernel command line because the 2.6 Linux
1811 kernels make very strict real time clock checks by default that QEMU
1812 cannot simulate exactly.
1814 When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1815 not activated because QEMU is slower with this patch. The QEMU
1816 Accelerator Module is also much slower in this case. Earlier Fedora
1817 Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this
1818 patch by default. Newer kernels don't have it.
1822 If you have a slow host, using Windows 95 is better as it gives the
1823 best speed. Windows 2000 is also a good choice.
1825 @subsubsection SVGA graphic modes support
1827 QEMU emulates a Cirrus Logic GD5446 Video
1828 card. All Windows versions starting from Windows 95 should recognize
1829 and use this graphic card. For optimal performances, use 16 bit color
1830 depth in the guest and the host OS.
1832 If you are using Windows XP as guest OS and if you want to use high
1833 resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
1834 1280x1024x16), then you should use the VESA VBE virtual graphic card
1835 (option @option{-std-vga}).
1837 @subsubsection CPU usage reduction
1839 Windows 9x does not correctly use the CPU HLT
1840 instruction. The result is that it takes host CPU cycles even when
1841 idle. You can install the utility from
1842 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
1843 problem. Note that no such tool is needed for NT, 2000 or XP.
1845 @subsubsection Windows 2000 disk full problem
1847 Windows 2000 has a bug which gives a disk full problem during its
1848 installation. When installing it, use the @option{-win2k-hack} QEMU
1849 option to enable a specific workaround. After Windows 2000 is
1850 installed, you no longer need this option (this option slows down the
1853 @subsubsection Windows 2000 shutdown
1855 Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1856 can. It comes from the fact that Windows 2000 does not automatically
1857 use the APM driver provided by the BIOS.
1859 In order to correct that, do the following (thanks to Struan
1860 Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1861 Add/Troubleshoot a device => Add a new device & Next => No, select the
1862 hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1863 (again) a few times. Now the driver is installed and Windows 2000 now
1864 correctly instructs QEMU to shutdown at the appropriate moment.
1866 @subsubsection Share a directory between Unix and Windows
1868 See @ref{sec_invocation} about the help of the option @option{-smb}.
1870 @subsubsection Windows XP security problem
1872 Some releases of Windows XP install correctly but give a security
1875 A problem is preventing Windows from accurately checking the
1876 license for this computer. Error code: 0x800703e6.
1879 The workaround is to install a service pack for XP after a boot in safe
1880 mode. Then reboot, and the problem should go away. Since there is no
1881 network while in safe mode, its recommended to download the full
1882 installation of SP1 or SP2 and transfer that via an ISO or using the
1883 vvfat block device ("-hdb fat:directory_which_holds_the_SP").
1885 @subsection MS-DOS and FreeDOS
1887 @subsubsection CPU usage reduction
1889 DOS does not correctly use the CPU HLT instruction. The result is that
1890 it takes host CPU cycles even when idle. You can install the utility
1891 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1894 @node QEMU System emulator for non PC targets
1895 @chapter QEMU System emulator for non PC targets
1897 QEMU is a generic emulator and it emulates many non PC
1898 machines. Most of the options are similar to the PC emulator. The
1899 differences are mentioned in the following sections.
1902 * PowerPC System emulator::
1903 * Sparc32 System emulator::
1904 * Sparc64 System emulator::
1905 * MIPS System emulator::
1906 * ARM System emulator::
1907 * ColdFire System emulator::
1908 * Cris System emulator::
1909 * Microblaze System emulator::
1910 * SH4 System emulator::
1911 * Xtensa System emulator::
1914 @node PowerPC System emulator
1915 @section PowerPC System emulator
1916 @cindex system emulation (PowerPC)
1918 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1919 or PowerMac PowerPC system.
1921 QEMU emulates the following PowerMac peripherals:
1925 UniNorth or Grackle PCI Bridge
1927 PCI VGA compatible card with VESA Bochs Extensions
1929 2 PMAC IDE interfaces with hard disk and CD-ROM support
1935 VIA-CUDA with ADB keyboard and mouse.
1938 QEMU emulates the following PREP peripherals:
1944 PCI VGA compatible card with VESA Bochs Extensions
1946 2 IDE interfaces with hard disk and CD-ROM support
1950 NE2000 network adapters
1954 PREP Non Volatile RAM
1956 PC compatible keyboard and mouse.
1959 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS.
1961 Since version 0.9.1, QEMU uses OpenBIOS @url{http://www.openbios.org/}
1962 for the g3beige and mac99 PowerMac machines. OpenBIOS is a free (GPL
1963 v2) portable firmware implementation. The goal is to implement a 100%
1964 IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.
1966 @c man begin OPTIONS
1968 The following options are specific to the PowerPC emulation:
1972 @item -g @var{W}x@var{H}[x@var{DEPTH}]
1974 Set the initial VGA graphic mode. The default is 800x600x32.
1976 @item -prom-env @var{string}
1978 Set OpenBIOS variables in NVRAM, for example:
1981 qemu-system-ppc -prom-env 'auto-boot?=false' \
1982 -prom-env 'boot-device=hd:2,\yaboot' \
1983 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
1986 These variables are not used by Open Hack'Ware.
1992 @node Sparc32 System emulator
1993 @section Sparc32 System emulator
1994 @cindex system emulation (Sparc32)
1996 Use the executable @file{qemu-system-sparc} to simulate the following
1997 Sun4m architecture machines:
2012 SPARCstation Voyager
2019 The emulation is somewhat complete. SMP up to 16 CPUs is supported,
2020 but Linux limits the number of usable CPUs to 4.
2022 QEMU emulates the following sun4m peripherals:
2028 TCX or cgthree Frame buffer
2030 Lance (Am7990) Ethernet
2032 Non Volatile RAM M48T02/M48T08
2034 Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
2035 and power/reset logic
2037 ESP SCSI controller with hard disk and CD-ROM support
2039 Floppy drive (not on SS-600MP)
2041 CS4231 sound device (only on SS-5, not working yet)
2044 The number of peripherals is fixed in the architecture. Maximum
2045 memory size depends on the machine type, for SS-5 it is 256MB and for
2048 Since version 0.8.2, QEMU uses OpenBIOS
2049 @url{http://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
2050 firmware implementation. The goal is to implement a 100% IEEE
2051 1275-1994 (referred to as Open Firmware) compliant firmware.
2053 A sample Linux 2.6 series kernel and ram disk image are available on
2054 the QEMU web site. There are still issues with NetBSD and OpenBSD, but
2055 most kernel versions work. Please note that currently older Solaris kernels
2056 don't work probably due to interface issues between OpenBIOS and
2059 @c man begin OPTIONS
2061 The following options are specific to the Sparc32 emulation:
2065 @item -g @var{W}x@var{H}x[x@var{DEPTH}]
2067 Set the initial graphics mode. For TCX, the default is 1024x768x8 with the
2068 option of 1024x768x24. For cgthree, the default is 1024x768x8 with the option
2069 of 1152x900x8 for people who wish to use OBP.
2071 @item -prom-env @var{string}
2073 Set OpenBIOS variables in NVRAM, for example:
2076 qemu-system-sparc -prom-env 'auto-boot?=false' \
2077 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
2080 @item -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic] [|SPARCbook]
2082 Set the emulated machine type. Default is SS-5.
2088 @node Sparc64 System emulator
2089 @section Sparc64 System emulator
2090 @cindex system emulation (Sparc64)
2092 Use the executable @file{qemu-system-sparc64} to simulate a Sun4u
2093 (UltraSPARC PC-like machine), Sun4v (T1 PC-like machine), or generic
2094 Niagara (T1) machine. The Sun4u emulator is mostly complete, being
2095 able to run Linux, NetBSD and OpenBSD in headless (-nographic) mode. The
2096 Sun4v and Niagara emulators are still a work in progress.
2098 QEMU emulates the following peripherals:
2102 UltraSparc IIi APB PCI Bridge
2104 PCI VGA compatible card with VESA Bochs Extensions
2106 PS/2 mouse and keyboard
2108 Non Volatile RAM M48T59
2110 PC-compatible serial ports
2112 2 PCI IDE interfaces with hard disk and CD-ROM support
2117 @c man begin OPTIONS
2119 The following options are specific to the Sparc64 emulation:
2123 @item -prom-env @var{string}
2125 Set OpenBIOS variables in NVRAM, for example:
2128 qemu-system-sparc64 -prom-env 'auto-boot?=false'
2131 @item -M [sun4u|sun4v|Niagara]
2133 Set the emulated machine type. The default is sun4u.
2139 @node MIPS System emulator
2140 @section MIPS System emulator
2141 @cindex system emulation (MIPS)
2143 Four executables cover simulation of 32 and 64-bit MIPS systems in
2144 both endian options, @file{qemu-system-mips}, @file{qemu-system-mipsel}
2145 @file{qemu-system-mips64} and @file{qemu-system-mips64el}.
2146 Five different machine types are emulated:
2150 A generic ISA PC-like machine "mips"
2152 The MIPS Malta prototype board "malta"
2154 An ACER Pica "pica61". This machine needs the 64-bit emulator.
2156 MIPS emulator pseudo board "mipssim"
2158 A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator.
2161 The generic emulation is supported by Debian 'Etch' and is able to
2162 install Debian into a virtual disk image. The following devices are
2167 A range of MIPS CPUs, default is the 24Kf
2169 PC style serial port
2176 The Malta emulation supports the following devices:
2180 Core board with MIPS 24Kf CPU and Galileo system controller
2182 PIIX4 PCI/USB/SMbus controller
2184 The Multi-I/O chip's serial device
2186 PCI network cards (PCnet32 and others)
2188 Malta FPGA serial device
2190 Cirrus (default) or any other PCI VGA graphics card
2193 The ACER Pica emulation supports:
2199 PC-style IRQ and DMA controllers
2206 The mipssim pseudo board emulation provides an environment similar
2207 to what the proprietary MIPS emulator uses for running Linux.
2212 A range of MIPS CPUs, default is the 24Kf
2214 PC style serial port
2216 MIPSnet network emulation
2219 The MIPS Magnum R4000 emulation supports:
2225 PC-style IRQ controller
2235 @node ARM System emulator
2236 @section ARM System emulator
2237 @cindex system emulation (ARM)
2239 Use the executable @file{qemu-system-arm} to simulate a ARM
2240 machine. The ARM Integrator/CP board is emulated with the following
2245 ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU
2249 SMC 91c111 Ethernet adapter
2251 PL110 LCD controller
2253 PL050 KMI with PS/2 keyboard and mouse.
2255 PL181 MultiMedia Card Interface with SD card.
2258 The ARM Versatile baseboard is emulated with the following devices:
2262 ARM926E, ARM1136 or Cortex-A8 CPU
2264 PL190 Vectored Interrupt Controller
2268 SMC 91c111 Ethernet adapter
2270 PL110 LCD controller
2272 PL050 KMI with PS/2 keyboard and mouse.
2274 PCI host bridge. Note the emulated PCI bridge only provides access to
2275 PCI memory space. It does not provide access to PCI IO space.
2276 This means some devices (eg. ne2k_pci NIC) are not usable, and others
2277 (eg. rtl8139 NIC) are only usable when the guest drivers use the memory
2278 mapped control registers.
2280 PCI OHCI USB controller.
2282 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
2284 PL181 MultiMedia Card Interface with SD card.
2287 Several variants of the ARM RealView baseboard are emulated,
2288 including the EB, PB-A8 and PBX-A9. Due to interactions with the
2289 bootloader, only certain Linux kernel configurations work out
2290 of the box on these boards.
2292 Kernels for the PB-A8 board should have CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2293 enabled in the kernel, and expect 512M RAM. Kernels for The PBX-A9 board
2294 should have CONFIG_SPARSEMEM enabled, CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2295 disabled and expect 1024M RAM.
2297 The following devices are emulated:
2301 ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU
2303 ARM AMBA Generic/Distributed Interrupt Controller
2307 SMC 91c111 or SMSC LAN9118 Ethernet adapter
2309 PL110 LCD controller
2311 PL050 KMI with PS/2 keyboard and mouse
2315 PCI OHCI USB controller
2317 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
2319 PL181 MultiMedia Card Interface with SD card.
2322 The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
2323 and "Terrier") emulation includes the following peripherals:
2327 Intel PXA270 System-on-chip (ARM V5TE core)
2331 IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
2333 On-chip OHCI USB controller
2335 On-chip LCD controller
2337 On-chip Real Time Clock
2339 TI ADS7846 touchscreen controller on SSP bus
2341 Maxim MAX1111 analog-digital converter on I@math{^2}C bus
2343 GPIO-connected keyboard controller and LEDs
2345 Secure Digital card connected to PXA MMC/SD host
2349 WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
2352 The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the
2357 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2359 ROM and RAM memories (ROM firmware image can be loaded with -option-rom)
2361 On-chip LCD controller
2363 On-chip Real Time Clock
2365 TI TSC2102i touchscreen controller / analog-digital converter / Audio
2366 CODEC, connected through MicroWire and I@math{^2}S busses
2368 GPIO-connected matrix keypad
2370 Secure Digital card connected to OMAP MMC/SD host
2375 Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48)
2376 emulation supports the following elements:
2380 Texas Instruments OMAP2420 System-on-chip (ARM 1136 core)
2382 RAM and non-volatile OneNAND Flash memories
2384 Display connected to EPSON remote framebuffer chip and OMAP on-chip
2385 display controller and a LS041y3 MIPI DBI-C controller
2387 TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers
2388 driven through SPI bus
2390 National Semiconductor LM8323-controlled qwerty keyboard driven
2391 through I@math{^2}C bus
2393 Secure Digital card connected to OMAP MMC/SD host
2395 Three OMAP on-chip UARTs and on-chip STI debugging console
2397 A Bluetooth(R) transceiver and HCI connected to an UART
2399 Mentor Graphics "Inventra" dual-role USB controller embedded in a TI
2400 TUSB6010 chip - only USB host mode is supported
2402 TI TMP105 temperature sensor driven through I@math{^2}C bus
2404 TI TWL92230C power management companion with an RTC on I@math{^2}C bus
2406 Nokia RETU and TAHVO multi-purpose chips with an RTC, connected
2410 The Luminary Micro Stellaris LM3S811EVB emulation includes the following
2417 64k Flash and 8k SRAM.
2419 Timers, UARTs, ADC and I@math{^2}C interface.
2421 OSRAM Pictiva 96x16 OLED with SSD0303 controller on I@math{^2}C bus.
2424 The Luminary Micro Stellaris LM3S6965EVB emulation includes the following
2431 256k Flash and 64k SRAM.
2433 Timers, UARTs, ADC, I@math{^2}C and SSI interfaces.
2435 OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI.
2438 The Freecom MusicPal internet radio emulation includes the following
2443 Marvell MV88W8618 ARM core.
2445 32 MB RAM, 256 KB SRAM, 8 MB flash.
2449 MV88W8xx8 Ethernet controller
2451 MV88W8618 audio controller, WM8750 CODEC and mixer
2453 128×64 display with brightness control
2455 2 buttons, 2 navigation wheels with button function
2458 The Siemens SX1 models v1 and v2 (default) basic emulation.
2459 The emulation includes the following elements:
2463 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2465 ROM and RAM memories (ROM firmware image can be loaded with -pflash)
2467 1 Flash of 16MB and 1 Flash of 8MB
2471 On-chip LCD controller
2473 On-chip Real Time Clock
2475 Secure Digital card connected to OMAP MMC/SD host
2480 A Linux 2.6 test image is available on the QEMU web site. More
2481 information is available in the QEMU mailing-list archive.
2483 @c man begin OPTIONS
2485 The following options are specific to the ARM emulation:
2490 Enable semihosting syscall emulation.
2492 On ARM this implements the "Angel" interface.
2494 Note that this allows guest direct access to the host filesystem,
2495 so should only be used with trusted guest OS.
2499 @node ColdFire System emulator
2500 @section ColdFire System emulator
2501 @cindex system emulation (ColdFire)
2502 @cindex system emulation (M68K)
2504 Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2505 The emulator is able to boot a uClinux kernel.
2507 The M5208EVB emulation includes the following devices:
2511 MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2513 Three Two on-chip UARTs.
2515 Fast Ethernet Controller (FEC)
2518 The AN5206 emulation includes the following devices:
2522 MCF5206 ColdFire V2 Microprocessor.
2527 @c man begin OPTIONS
2529 The following options are specific to the ColdFire emulation:
2534 Enable semihosting syscall emulation.
2536 On M68K this implements the "ColdFire GDB" interface used by libgloss.
2538 Note that this allows guest direct access to the host filesystem,
2539 so should only be used with trusted guest OS.
2543 @node Cris System emulator
2544 @section Cris System emulator
2545 @cindex system emulation (Cris)
2549 @node Microblaze System emulator
2550 @section Microblaze System emulator
2551 @cindex system emulation (Microblaze)
2555 @node SH4 System emulator
2556 @section SH4 System emulator
2557 @cindex system emulation (SH4)
2561 @node Xtensa System emulator
2562 @section Xtensa System emulator
2563 @cindex system emulation (Xtensa)
2565 Two executables cover simulation of both Xtensa endian options,
2566 @file{qemu-system-xtensa} and @file{qemu-system-xtensaeb}.
2567 Two different machine types are emulated:
2571 Xtensa emulator pseudo board "sim"
2573 Avnet LX60/LX110/LX200 board
2576 The sim pseudo board emulation provides an environment similar
2577 to one provided by the proprietary Tensilica ISS.
2582 A range of Xtensa CPUs, default is the DC232B
2584 Console and filesystem access via semihosting calls
2587 The Avnet LX60/LX110/LX200 emulation supports:
2591 A range of Xtensa CPUs, default is the DC232B
2595 OpenCores 10/100 Mbps Ethernet MAC
2598 @c man begin OPTIONS
2600 The following options are specific to the Xtensa emulation:
2605 Enable semihosting syscall emulation.
2607 Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select.
2608 Tensilica baremetal libc for ISS and linux platform "sim" use this interface.
2610 Note that this allows guest direct access to the host filesystem,
2611 so should only be used with trusted guest OS.
2614 @node QEMU User space emulator
2615 @chapter QEMU User space emulator
2618 * Supported Operating Systems ::
2619 * Linux User space emulator::
2620 * BSD User space emulator ::
2623 @node Supported Operating Systems
2624 @section Supported Operating Systems
2626 The following OS are supported in user space emulation:
2630 Linux (referred as qemu-linux-user)
2632 BSD (referred as qemu-bsd-user)
2635 @node Linux User space emulator
2636 @section Linux User space emulator
2641 * Command line options::
2646 @subsection Quick Start
2648 In order to launch a Linux process, QEMU needs the process executable
2649 itself and all the target (x86) dynamic libraries used by it.
2653 @item On x86, you can just try to launch any process by using the native
2657 qemu-i386 -L / /bin/ls
2660 @code{-L /} tells that the x86 dynamic linker must be searched with a
2663 @item Since QEMU is also a linux process, you can launch QEMU with
2664 QEMU (NOTE: you can only do that if you compiled QEMU from the sources):
2667 qemu-i386 -L / qemu-i386 -L / /bin/ls
2670 @item On non x86 CPUs, you need first to download at least an x86 glibc
2671 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2672 @code{LD_LIBRARY_PATH} is not set:
2675 unset LD_LIBRARY_PATH
2678 Then you can launch the precompiled @file{ls} x86 executable:
2681 qemu-i386 tests/i386/ls
2683 You can look at @file{scripts/qemu-binfmt-conf.sh} so that
2684 QEMU is automatically launched by the Linux kernel when you try to
2685 launch x86 executables. It requires the @code{binfmt_misc} module in the
2688 @item The x86 version of QEMU is also included. You can try weird things such as:
2690 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2691 /usr/local/qemu-i386/bin/ls-i386
2697 @subsection Wine launch
2701 @item Ensure that you have a working QEMU with the x86 glibc
2702 distribution (see previous section). In order to verify it, you must be
2706 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2709 @item Download the binary x86 Wine install
2710 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2712 @item Configure Wine on your account. Look at the provided script
2713 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2714 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2716 @item Then you can try the example @file{putty.exe}:
2719 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2720 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2725 @node Command line options
2726 @subsection Command line options
2729 usage: qemu-i386 [-h] [-d] [-L path] [-s size] [-cpu model] [-g port] [-B offset] [-R size] program [arguments...]
2736 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2738 Set the x86 stack size in bytes (default=524288)
2740 Select CPU model (-cpu help for list and additional feature selection)
2741 @item -E @var{var}=@var{value}
2742 Set environment @var{var} to @var{value}.
2744 Remove @var{var} from the environment.
2746 Offset guest address by the specified number of bytes. This is useful when
2747 the address region required by guest applications is reserved on the host.
2748 This option is currently only supported on some hosts.
2750 Pre-allocate a guest virtual address space of the given size (in bytes).
2751 "G", "M", and "k" suffixes may be used when specifying the size.
2758 Activate logging of the specified items (use '-d help' for a list of log items)
2760 Act as if the host page size was 'pagesize' bytes
2762 Wait gdb connection to port
2764 Run the emulation in single step mode.
2767 Environment variables:
2771 Print system calls and arguments similar to the 'strace' program
2772 (NOTE: the actual 'strace' program will not work because the user
2773 space emulator hasn't implemented ptrace). At the moment this is
2774 incomplete. All system calls that don't have a specific argument
2775 format are printed with information for six arguments. Many
2776 flag-style arguments don't have decoders and will show up as numbers.
2779 @node Other binaries
2780 @subsection Other binaries
2782 @cindex user mode (Alpha)
2783 @command{qemu-alpha} TODO.
2785 @cindex user mode (ARM)
2786 @command{qemu-armeb} TODO.
2788 @cindex user mode (ARM)
2789 @command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2790 binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2791 configurations), and arm-uclinux bFLT format binaries.
2793 @cindex user mode (ColdFire)
2794 @cindex user mode (M68K)
2795 @command{qemu-m68k} is capable of running semihosted binaries using the BDM
2796 (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2797 coldfire uClinux bFLT format binaries.
2799 The binary format is detected automatically.
2801 @cindex user mode (Cris)
2802 @command{qemu-cris} TODO.
2804 @cindex user mode (i386)
2805 @command{qemu-i386} TODO.
2806 @command{qemu-x86_64} TODO.
2808 @cindex user mode (Microblaze)
2809 @command{qemu-microblaze} TODO.
2811 @cindex user mode (MIPS)
2812 @command{qemu-mips} TODO.
2813 @command{qemu-mipsel} TODO.
2815 @cindex user mode (PowerPC)
2816 @command{qemu-ppc64abi32} TODO.
2817 @command{qemu-ppc64} TODO.
2818 @command{qemu-ppc} TODO.
2820 @cindex user mode (SH4)
2821 @command{qemu-sh4eb} TODO.
2822 @command{qemu-sh4} TODO.
2824 @cindex user mode (SPARC)
2825 @command{qemu-sparc} can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).
2827 @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2828 (Sparc64 CPU, 32 bit ABI).
2830 @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2831 SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2833 @node BSD User space emulator
2834 @section BSD User space emulator
2839 * BSD Command line options::
2843 @subsection BSD Status
2847 target Sparc64 on Sparc64: Some trivial programs work.
2850 @node BSD Quick Start
2851 @subsection Quick Start
2853 In order to launch a BSD process, QEMU needs the process executable
2854 itself and all the target dynamic libraries used by it.
2858 @item On Sparc64, you can just try to launch any process by using the native
2862 qemu-sparc64 /bin/ls
2867 @node BSD Command line options
2868 @subsection Command line options
2871 usage: qemu-sparc64 [-h] [-d] [-L path] [-s size] [-bsd type] program [arguments...]
2878 Set the library root path (default=/)
2880 Set the stack size in bytes (default=524288)
2881 @item -ignore-environment
2882 Start with an empty environment. Without this option,
2883 the initial environment is a copy of the caller's environment.
2884 @item -E @var{var}=@var{value}
2885 Set environment @var{var} to @var{value}.
2887 Remove @var{var} from the environment.
2889 Set the type of the emulated BSD Operating system. Valid values are
2890 FreeBSD, NetBSD and OpenBSD (default).
2897 Activate logging of the specified items (use '-d help' for a list of log items)
2899 Act as if the host page size was 'pagesize' bytes
2901 Run the emulation in single step mode.
2905 @chapter Compilation from the sources
2910 * Cross compilation for Windows with Linux::
2918 @subsection Compilation
2920 First you must decompress the sources:
2923 tar zxvf qemu-x.y.z.tar.gz
2927 Then you configure QEMU and build it (usually no options are needed):
2933 Then type as root user:
2937 to install QEMU in @file{/usr/local}.
2943 @item Install the current versions of MSYS and MinGW from
2944 @url{http://www.mingw.org/}. You can find detailed installation
2945 instructions in the download section and the FAQ.
2948 the MinGW development library of SDL 1.2.x
2949 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
2950 @url{http://www.libsdl.org}. Unpack it in a temporary place and
2951 edit the @file{sdl-config} script so that it gives the
2952 correct SDL directory when invoked.
2954 @item Install the MinGW version of zlib and make sure
2955 @file{zlib.h} and @file{libz.dll.a} are in
2956 MinGW's default header and linker search paths.
2958 @item Extract the current version of QEMU.
2960 @item Start the MSYS shell (file @file{msys.bat}).
2962 @item Change to the QEMU directory. Launch @file{./configure} and
2963 @file{make}. If you have problems using SDL, verify that
2964 @file{sdl-config} can be launched from the MSYS command line.
2966 @item You can install QEMU in @file{Program Files/QEMU} by typing
2967 @file{make install}. Don't forget to copy @file{SDL.dll} in
2968 @file{Program Files/QEMU}.
2972 @node Cross compilation for Windows with Linux
2973 @section Cross compilation for Windows with Linux
2977 Install the MinGW cross compilation tools available at
2978 @url{http://www.mingw.org/}.
2981 the MinGW development library of SDL 1.2.x
2982 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
2983 @url{http://www.libsdl.org}. Unpack it in a temporary place and
2984 edit the @file{sdl-config} script so that it gives the
2985 correct SDL directory when invoked. Set up the @code{PATH} environment
2986 variable so that @file{sdl-config} can be launched by
2987 the QEMU configuration script.
2989 @item Install the MinGW version of zlib and make sure
2990 @file{zlib.h} and @file{libz.dll.a} are in
2991 MinGW's default header and linker search paths.
2994 Configure QEMU for Windows cross compilation:
2996 PATH=/usr/i686-pc-mingw32/sys-root/mingw/bin:$PATH ./configure --cross-prefix='i686-pc-mingw32-'
2998 The example assumes @file{sdl-config} is installed under @file{/usr/i686-pc-mingw32/sys-root/mingw/bin} and
2999 MinGW cross compilation tools have names like @file{i686-pc-mingw32-gcc} and @file{i686-pc-mingw32-strip}.
3000 We set the @code{PATH} environment variable to ensure the MinGW version of @file{sdl-config} is used and
3001 use --cross-prefix to specify the name of the cross compiler.
3002 You can also use --prefix to set the Win32 install path which defaults to @file{c:/Program Files/QEMU}.
3004 Under Fedora Linux, you can run:
3006 yum -y install mingw32-gcc mingw32-SDL mingw32-zlib
3008 to get a suitable cross compilation environment.
3010 @item You can install QEMU in the installation directory by typing
3011 @code{make install}. Don't forget to copy @file{SDL.dll} and @file{zlib1.dll} into the
3012 installation directory.
3016 @cindex wine, starting system emulation
3017 Wine can be used to launch the resulting qemu-system-i386.exe
3018 and all other qemu-system-@var{target}.exe compiled for Win32.
3020 wine qemu-system-i386
3026 The Mac OS X patches are not fully merged in QEMU, so you should look
3027 at the QEMU mailing list archive to have all the necessary
3028 information. (TODO: is this still true?)
3031 @section Make targets
3037 Make everything which is typically needed.
3046 Remove most files which were built during make.
3048 @item make distclean
3049 Remove everything which was built during make.
3055 Create documentation in dvi, html, info or pdf format.
3060 @item make defconfig
3061 (Re-)create some build configuration files.
3062 User made changes will be overwritten.
3073 QEMU is a trademark of Fabrice Bellard.
3075 QEMU is released under the GNU General Public License (TODO: add link).
3076 Parts of QEMU have specific licenses, see file LICENSE.
3078 TODO (refer to file LICENSE, include it, include the GPL?)
3092 @section Concept Index
3093 This is the main index. Should we combine all keywords in one index? TODO
3096 @node Function Index
3097 @section Function Index
3098 This index could be used for command line options and monitor functions.
3101 @node Keystroke Index
3102 @section Keystroke Index
3104 This is a list of all keystrokes which have a special function
3105 in system emulation.
3110 @section Program Index
3113 @node Data Type Index
3114 @section Data Type Index
3116 This index could be used for qdev device names and options.
3120 @node Variable Index
3121 @section Variable Index