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 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
161 * pcsys_keys:: Keys in the graphical frontends
162 * mux_keys:: Keys in the character backend multiplexer
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 IPMI BMC, either and internal or external one
201 Creative SoundBlaster 16 sound card
203 ENSONIQ AudioPCI ES1370 sound card
205 Intel 82801AA AC97 Audio compatible sound card
207 Intel HD Audio Controller and HDA codec
209 Adlib (OPL2) - Yamaha YM3812 compatible chip
211 Gravis Ultrasound GF1 sound card
213 CS4231A compatible sound card
215 PCI UHCI USB controller and a virtual USB hub.
218 SMP is supported with up to 255 CPUs.
220 QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs LGPL
223 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
225 QEMU uses GUS emulation (GUSEMU32 @url{http://www.deinmeister.de/gusemu/})
226 by Tibor "TS" Schütz.
228 Note that, by default, GUS shares IRQ(7) with parallel ports and so
229 QEMU must be told to not have parallel ports to have working GUS.
232 qemu-system-i386 dos.img -soundhw gus -parallel none
237 qemu-system-i386 dos.img -device gus,irq=5
240 Or some other unclaimed IRQ.
242 CS4231A is the chip used in Windows Sound System and GUSMAX products
246 @node pcsys_quickstart
250 Download and uncompress the linux image (@file{linux.img}) and type:
253 qemu-system-i386 linux.img
256 Linux should boot and give you a prompt.
262 @c man begin SYNOPSIS
263 @command{qemu-system-i386} [@var{options}] [@var{disk_image}]
268 @var{disk_image} is a raw hard disk image for IDE hard disk 0. Some
269 targets do not need a disk image.
271 @include qemu-options.texi
276 @section Keys in the graphical frontends
280 During the graphical emulation, you can use special key combinations to change
281 modes. The default key mappings are shown below, but if you use @code{-alt-grab}
282 then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use
283 @code{-ctrl-grab} then the modifier is the right Ctrl key (instead of Ctrl-Alt):
300 Restore the screen's un-scaled dimensions
304 Switch to virtual console 'n'. Standard console mappings are:
307 Target system display
316 Toggle mouse and keyboard grab.
322 @kindex Ctrl-PageDown
323 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
324 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
329 @section Keys in the character backend multiplexer
333 During emulation, if you are using a character backend multiplexer
334 (which is the default if you are using @option{-nographic}) then
335 several commands are available via an escape sequence. These
336 key sequences all start with an escape character, which is @key{Ctrl-a}
337 by default, but can be changed with @option{-echr}. The list below assumes
338 you're using the default.
349 Save disk data back to file (if -snapshot)
352 Toggle console timestamps
355 Send break (magic sysrq in Linux)
358 Rotate between the frontends connected to the multiplexer (usually
359 this switches between the monitor and the console)
361 @kindex Ctrl-a Ctrl-a
362 Send the escape character to the frontend
369 The HTML documentation of QEMU for more precise information and Linux
370 user mode emulator invocation.
380 @section QEMU Monitor
383 The QEMU monitor is used to give complex commands to the QEMU
384 emulator. You can use it to:
389 Remove or insert removable media images
390 (such as CD-ROM or floppies).
393 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
396 @item Inspect the VM state without an external debugger.
402 The following commands are available:
404 @include qemu-monitor.texi
406 @include qemu-monitor-info.texi
408 @subsection Integer expressions
410 The monitor understands integers expressions for every integer
411 argument. You can use register names to get the value of specifics
412 CPU registers by prefixing them with @emph{$}.
417 Since version 0.6.1, QEMU supports many disk image formats, including
418 growable disk images (their size increase as non empty sectors are
419 written), compressed and encrypted disk images. Version 0.8.3 added
420 the new qcow2 disk image format which is essential to support VM
424 * disk_images_quickstart:: Quick start for disk image creation
425 * disk_images_snapshot_mode:: Snapshot mode
426 * vm_snapshots:: VM snapshots
427 * qemu_img_invocation:: qemu-img Invocation
428 * qemu_nbd_invocation:: qemu-nbd Invocation
429 * qemu_ga_invocation:: qemu-ga Invocation
430 * disk_images_formats:: Disk image file formats
431 * host_drives:: Using host drives
432 * disk_images_fat_images:: Virtual FAT disk images
433 * disk_images_nbd:: NBD access
434 * disk_images_sheepdog:: Sheepdog disk images
435 * disk_images_iscsi:: iSCSI LUNs
436 * disk_images_gluster:: GlusterFS disk images
437 * disk_images_ssh:: Secure Shell (ssh) disk images
440 @node disk_images_quickstart
441 @subsection Quick start for disk image creation
443 You can create a disk image with the command:
445 qemu-img create myimage.img mysize
447 where @var{myimage.img} is the disk image filename and @var{mysize} is its
448 size in kilobytes. You can add an @code{M} suffix to give the size in
449 megabytes and a @code{G} suffix for gigabytes.
451 See @ref{qemu_img_invocation} for more information.
453 @node disk_images_snapshot_mode
454 @subsection Snapshot mode
456 If you use the option @option{-snapshot}, all disk images are
457 considered as read only. When sectors in written, they are written in
458 a temporary file created in @file{/tmp}. You can however force the
459 write back to the raw disk images by using the @code{commit} monitor
460 command (or @key{C-a s} in the serial console).
463 @subsection VM snapshots
465 VM snapshots are snapshots of the complete virtual machine including
466 CPU state, RAM, device state and the content of all the writable
467 disks. In order to use VM snapshots, you must have at least one non
468 removable and writable block device using the @code{qcow2} disk image
469 format. Normally this device is the first virtual hard drive.
471 Use the monitor command @code{savevm} to create a new VM snapshot or
472 replace an existing one. A human readable name can be assigned to each
473 snapshot in addition to its numerical ID.
475 Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
476 a VM snapshot. @code{info snapshots} lists the available snapshots
477 with their associated information:
480 (qemu) info snapshots
481 Snapshot devices: hda
482 Snapshot list (from hda):
483 ID TAG VM SIZE DATE VM CLOCK
484 1 start 41M 2006-08-06 12:38:02 00:00:14.954
485 2 40M 2006-08-06 12:43:29 00:00:18.633
486 3 msys 40M 2006-08-06 12:44:04 00:00:23.514
489 A VM snapshot is made of a VM state info (its size is shown in
490 @code{info snapshots}) and a snapshot of every writable disk image.
491 The VM state info is stored in the first @code{qcow2} non removable
492 and writable block device. The disk image snapshots are stored in
493 every disk image. The size of a snapshot in a disk image is difficult
494 to evaluate and is not shown by @code{info snapshots} because the
495 associated disk sectors are shared among all the snapshots to save
496 disk space (otherwise each snapshot would need a full copy of all the
499 When using the (unrelated) @code{-snapshot} option
500 (@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
501 but they are deleted as soon as you exit QEMU.
503 VM snapshots currently have the following known limitations:
506 They cannot cope with removable devices if they are removed or
507 inserted after a snapshot is done.
509 A few device drivers still have incomplete snapshot support so their
510 state is not saved or restored properly (in particular USB).
513 @node qemu_img_invocation
514 @subsection @code{qemu-img} Invocation
516 @include qemu-img.texi
518 @node qemu_nbd_invocation
519 @subsection @code{qemu-nbd} Invocation
521 @include qemu-nbd.texi
523 @node qemu_ga_invocation
524 @subsection @code{qemu-ga} Invocation
526 @include qemu-ga.texi
528 @node disk_images_formats
529 @subsection Disk image file formats
531 QEMU supports many image file formats that can be used with VMs as well as with
532 any of the tools (like @code{qemu-img}). This includes the preferred formats
533 raw and qcow2 as well as formats that are supported for compatibility with
534 older QEMU versions or other hypervisors.
536 Depending on the image format, different options can be passed to
537 @code{qemu-img create} and @code{qemu-img convert} using the @code{-o} option.
538 This section describes each format and the options that are supported for it.
543 Raw disk image format. This format has the advantage of
544 being simple and easily exportable to all other emulators. If your
545 file system supports @emph{holes} (for example in ext2 or ext3 on
546 Linux or NTFS on Windows), then only the written sectors will reserve
547 space. Use @code{qemu-img info} to know the real size used by the
548 image or @code{ls -ls} on Unix/Linux.
553 Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}).
554 @code{falloc} mode preallocates space for image by calling posix_fallocate().
555 @code{full} mode preallocates space for image by writing zeros to underlying
560 QEMU image format, the most versatile format. Use it to have smaller
561 images (useful if your filesystem does not supports holes, for example
562 on Windows), zlib based compression and support of multiple VM
568 Determines the qcow2 version to use. @code{compat=0.10} uses the
569 traditional image format that can be read by any QEMU since 0.10.
570 @code{compat=1.1} enables image format extensions that only QEMU 1.1 and
571 newer understand (this is the default). Amongst others, this includes
572 zero clusters, which allow efficient copy-on-read for sparse images.
575 File name of a base image (see @option{create} subcommand)
577 Image format of the base image
579 If this option is set to @code{on}, the image is encrypted with 128-bit AES-CBC.
581 The use of encryption in qcow and qcow2 images is considered to be flawed by
582 modern cryptography standards, suffering from a number of design problems:
585 @item The AES-CBC cipher is used with predictable initialization vectors based
586 on the sector number. This makes it vulnerable to chosen plaintext attacks
587 which can reveal the existence of encrypted data.
588 @item The user passphrase is directly used as the encryption key. A poorly
589 chosen or short passphrase will compromise the security of the encryption.
590 @item In the event of the passphrase being compromised there is no way to
591 change the passphrase to protect data in any qcow images. The files must
592 be cloned, using a different encryption passphrase in the new file. The
593 original file must then be securely erased using a program like shred,
594 though even this is ineffective with many modern storage technologies.
597 Use of qcow / qcow2 encryption with QEMU is deprecated, and support for
598 it will go away in a future release. Users are recommended to use an
599 alternative encryption technology such as the Linux dm-crypt / LUKS
603 Changes the qcow2 cluster size (must be between 512 and 2M). Smaller cluster
604 sizes can improve the image file size whereas larger cluster sizes generally
605 provide better performance.
608 Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
609 @code{full}). An image with preallocated metadata is initially larger but can
610 improve performance when the image needs to grow. @code{falloc} and @code{full}
611 preallocations are like the same options of @code{raw} format, but sets up
615 If this option is set to @code{on}, reference count updates are postponed with
616 the goal of avoiding metadata I/O and improving performance. This is
617 particularly interesting with @option{cache=writethrough} which doesn't batch
618 metadata updates. The tradeoff is that after a host crash, the reference count
619 tables must be rebuilt, i.e. on the next open an (automatic) @code{qemu-img
620 check -r all} is required, which may take some time.
622 This option can only be enabled if @code{compat=1.1} is specified.
625 If this option is set to @code{on}, it will turn off COW of the file. It's only
626 valid on btrfs, no effect on other file systems.
628 Btrfs has low performance when hosting a VM image file, even more when the guest
629 on the VM also using btrfs as file system. Turning off COW is a way to mitigate
630 this bad performance. Generally there are two ways to turn off COW on btrfs:
631 a) Disable it by mounting with nodatacow, then all newly created files will be
632 NOCOW. b) For an empty file, add the NOCOW file attribute. That's what this option
635 Note: this option is only valid to new or empty files. If there is an existing
636 file which is COW and has data blocks already, it couldn't be changed to NOCOW
637 by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if
638 the NOCOW flag is set or not (Capital 'C' is NOCOW flag).
643 Old QEMU image format with support for backing files and compact image files
644 (when your filesystem or transport medium does not support holes).
646 When converting QED images to qcow2, you might want to consider using the
647 @code{lazy_refcounts=on} option to get a more QED-like behaviour.
652 File name of a base image (see @option{create} subcommand).
654 Image file format of backing file (optional). Useful if the format cannot be
655 autodetected because it has no header, like some vhd/vpc files.
657 Changes the cluster size (must be power-of-2 between 4K and 64K). Smaller
658 cluster sizes can improve the image file size whereas larger cluster sizes
659 generally provide better performance.
661 Changes the number of clusters per L1/L2 table (must be power-of-2 between 1
662 and 16). There is normally no need to change this value but this option can be
663 used for performance benchmarking.
667 Old QEMU image format with support for backing files, compact image files,
668 encryption and compression.
673 File name of a base image (see @option{create} subcommand)
675 If this option is set to @code{on}, the image is encrypted.
679 VirtualBox 1.1 compatible image format.
683 If this option is set to @code{on}, the image is created with metadata
688 VMware 3 and 4 compatible image format.
693 File name of a base image (see @option{create} subcommand).
695 Create a VMDK version 6 image (instead of version 4)
697 Specifies which VMDK subformat to use. Valid options are
698 @code{monolithicSparse} (default),
699 @code{monolithicFlat},
700 @code{twoGbMaxExtentSparse},
701 @code{twoGbMaxExtentFlat} and
702 @code{streamOptimized}.
706 VirtualPC compatible image format (VHD).
710 Specifies which VHD subformat to use. Valid options are
711 @code{dynamic} (default) and @code{fixed}.
715 Hyper-V compatible image format (VHDX).
719 Specifies which VHDX subformat to use. Valid options are
720 @code{dynamic} (default) and @code{fixed}.
721 @item block_state_zero
722 Force use of payload blocks of type 'ZERO'. Can be set to @code{on} (default)
723 or @code{off}. When set to @code{off}, new blocks will be created as
724 @code{PAYLOAD_BLOCK_NOT_PRESENT}, which means parsers are free to return
725 arbitrary data for those blocks. Do not set to @code{off} when using
726 @code{qemu-img convert} with @code{subformat=dynamic}.
728 Block size; min 1 MB, max 256 MB. 0 means auto-calculate based on image size.
734 @subsubsection Read-only formats
735 More disk image file formats are supported in a read-only mode.
738 Bochs images of @code{growing} type.
740 Linux Compressed Loop image, useful only to reuse directly compressed
741 CD-ROM images present for example in the Knoppix CD-ROMs.
745 Parallels disk image format.
750 @subsection Using host drives
752 In addition to disk image files, QEMU can directly access host
753 devices. We describe here the usage for QEMU version >= 0.8.3.
757 On Linux, you can directly use the host device filename instead of a
758 disk image filename provided you have enough privileges to access
759 it. For example, use @file{/dev/cdrom} to access to the CDROM.
763 You can specify a CDROM device even if no CDROM is loaded. QEMU has
764 specific code to detect CDROM insertion or removal. CDROM ejection by
765 the guest OS is supported. Currently only data CDs are supported.
767 You can specify a floppy device even if no floppy is loaded. Floppy
768 removal is currently not detected accurately (if you change floppy
769 without doing floppy access while the floppy is not loaded, the guest
770 OS will think that the same floppy is loaded).
771 Use of the host's floppy device is deprecated, and support for it will
772 be removed in a future release.
774 Hard disks can be used. Normally you must specify the whole disk
775 (@file{/dev/hdb} instead of @file{/dev/hdb1}) so that the guest OS can
776 see it as a partitioned disk. WARNING: unless you know what you do, it
777 is better to only make READ-ONLY accesses to the hard disk otherwise
778 you may corrupt your host data (use the @option{-snapshot} command
779 line option or modify the device permissions accordingly).
782 @subsubsection Windows
786 The preferred syntax is the drive letter (e.g. @file{d:}). The
787 alternate syntax @file{\\.\d:} is supported. @file{/dev/cdrom} is
788 supported as an alias to the first CDROM drive.
790 Currently there is no specific code to handle removable media, so it
791 is better to use the @code{change} or @code{eject} monitor commands to
792 change or eject media.
794 Hard disks can be used with the syntax: @file{\\.\PhysicalDrive@var{N}}
795 where @var{N} is the drive number (0 is the first hard disk).
797 WARNING: unless you know what you do, it is better to only make
798 READ-ONLY accesses to the hard disk otherwise you may corrupt your
799 host data (use the @option{-snapshot} command line so that the
800 modifications are written in a temporary file).
804 @subsubsection Mac OS X
806 @file{/dev/cdrom} is an alias to the first CDROM.
808 Currently there is no specific code to handle removable media, so it
809 is better to use the @code{change} or @code{eject} monitor commands to
810 change or eject media.
812 @node disk_images_fat_images
813 @subsection Virtual FAT disk images
815 QEMU can automatically create a virtual FAT disk image from a
816 directory tree. In order to use it, just type:
819 qemu-system-i386 linux.img -hdb fat:/my_directory
822 Then you access access to all the files in the @file{/my_directory}
823 directory without having to copy them in a disk image or to export
824 them via SAMBA or NFS. The default access is @emph{read-only}.
826 Floppies can be emulated with the @code{:floppy:} option:
829 qemu-system-i386 linux.img -fda fat:floppy:/my_directory
832 A read/write support is available for testing (beta stage) with the
836 qemu-system-i386 linux.img -fda fat:floppy:rw:/my_directory
839 What you should @emph{never} do:
841 @item use non-ASCII filenames ;
842 @item use "-snapshot" together with ":rw:" ;
843 @item expect it to work when loadvm'ing ;
844 @item write to the FAT directory on the host system while accessing it with the guest system.
847 @node disk_images_nbd
848 @subsection NBD access
850 QEMU can access directly to block device exported using the Network Block Device
854 qemu-system-i386 linux.img -hdb nbd://my_nbd_server.mydomain.org:1024/
857 If the NBD server is located on the same host, you can use an unix socket instead
861 qemu-system-i386 linux.img -hdb nbd+unix://?socket=/tmp/my_socket
864 In this case, the block device must be exported using qemu-nbd:
867 qemu-nbd --socket=/tmp/my_socket my_disk.qcow2
870 The use of qemu-nbd allows sharing of a disk between several guests:
872 qemu-nbd --socket=/tmp/my_socket --share=2 my_disk.qcow2
876 and then you can use it with two guests:
878 qemu-system-i386 linux1.img -hdb nbd+unix://?socket=/tmp/my_socket
879 qemu-system-i386 linux2.img -hdb nbd+unix://?socket=/tmp/my_socket
882 If the nbd-server uses named exports (supported since NBD 2.9.18, or with QEMU's
883 own embedded NBD server), you must specify an export name in the URI:
885 qemu-system-i386 -cdrom nbd://localhost/debian-500-ppc-netinst
886 qemu-system-i386 -cdrom nbd://localhost/openSUSE-11.1-ppc-netinst
889 The URI syntax for NBD is supported since QEMU 1.3. An alternative syntax is
890 also available. Here are some example of the older syntax:
892 qemu-system-i386 linux.img -hdb nbd:my_nbd_server.mydomain.org:1024
893 qemu-system-i386 linux2.img -hdb nbd:unix:/tmp/my_socket
894 qemu-system-i386 -cdrom nbd:localhost:10809:exportname=debian-500-ppc-netinst
897 @node disk_images_sheepdog
898 @subsection Sheepdog disk images
900 Sheepdog is a distributed storage system for QEMU. It provides highly
901 available block level storage volumes that can be attached to
902 QEMU-based virtual machines.
904 You can create a Sheepdog disk image with the command:
906 qemu-img create sheepdog:///@var{image} @var{size}
908 where @var{image} is the Sheepdog image name and @var{size} is its
911 To import the existing @var{filename} to Sheepdog, you can use a
914 qemu-img convert @var{filename} sheepdog:///@var{image}
917 You can boot from the Sheepdog disk image with the command:
919 qemu-system-i386 sheepdog:///@var{image}
922 You can also create a snapshot of the Sheepdog image like qcow2.
924 qemu-img snapshot -c @var{tag} sheepdog:///@var{image}
926 where @var{tag} is a tag name of the newly created snapshot.
928 To boot from the Sheepdog snapshot, specify the tag name of the
931 qemu-system-i386 sheepdog:///@var{image}#@var{tag}
934 You can create a cloned image from the existing snapshot.
936 qemu-img create -b sheepdog:///@var{base}#@var{tag} sheepdog:///@var{image}
938 where @var{base} is a image name of the source snapshot and @var{tag}
941 You can use an unix socket instead of an inet socket:
944 qemu-system-i386 sheepdog+unix:///@var{image}?socket=@var{path}
947 If the Sheepdog daemon doesn't run on the local host, you need to
948 specify one of the Sheepdog servers to connect to.
950 qemu-img create sheepdog://@var{hostname}:@var{port}/@var{image} @var{size}
951 qemu-system-i386 sheepdog://@var{hostname}:@var{port}/@var{image}
954 @node disk_images_iscsi
955 @subsection iSCSI LUNs
957 iSCSI is a popular protocol used to access SCSI devices across a computer
960 There are two different ways iSCSI devices can be used by QEMU.
962 The first method is to mount the iSCSI LUN on the host, and make it appear as
963 any other ordinary SCSI device on the host and then to access this device as a
964 /dev/sd device from QEMU. How to do this differs between host OSes.
966 The second method involves using the iSCSI initiator that is built into
967 QEMU. This provides a mechanism that works the same way regardless of which
968 host OS you are running QEMU on. This section will describe this second method
969 of using iSCSI together with QEMU.
971 In QEMU, iSCSI devices are described using special iSCSI URLs
975 iscsi://[<username>[%<password>]@@]<host>[:<port>]/<target-iqn-name>/<lun>
978 Username and password are optional and only used if your target is set up
979 using CHAP authentication for access control.
980 Alternatively the username and password can also be set via environment
981 variables to have these not show up in the process list
984 export LIBISCSI_CHAP_USERNAME=<username>
985 export LIBISCSI_CHAP_PASSWORD=<password>
986 iscsi://<host>/<target-iqn-name>/<lun>
989 Various session related parameters can be set via special options, either
990 in a configuration file provided via '-readconfig' or directly on the
993 If the initiator-name is not specified qemu will use a default name
994 of 'iqn.2008-11.org.linux-kvm[:<name>'] where <name> is the name of the
999 Setting a specific initiator name to use when logging in to the target
1000 -iscsi initiator-name=iqn.qemu.test:my-initiator
1004 Controlling which type of header digest to negotiate with the target
1005 -iscsi header-digest=CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1008 These can also be set via a configuration file
1011 user = "CHAP username"
1012 password = "CHAP password"
1013 initiator-name = "iqn.qemu.test:my-initiator"
1014 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1015 header-digest = "CRC32C"
1019 Setting the target name allows different options for different targets
1021 [iscsi "iqn.target.name"]
1022 user = "CHAP username"
1023 password = "CHAP password"
1024 initiator-name = "iqn.qemu.test:my-initiator"
1025 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1026 header-digest = "CRC32C"
1030 Howto use a configuration file to set iSCSI configuration options:
1032 cat >iscsi.conf <<EOF
1035 password = "my password"
1036 initiator-name = "iqn.qemu.test:my-initiator"
1037 header-digest = "CRC32C"
1040 qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1041 -readconfig iscsi.conf
1045 Howto set up a simple iSCSI target on loopback and accessing it via QEMU:
1047 This example shows how to set up an iSCSI target with one CDROM and one DISK
1048 using the Linux STGT software target. This target is available on Red Hat based
1049 systems as the package 'scsi-target-utils'.
1051 tgtd --iscsi portal=127.0.0.1:3260
1052 tgtadm --lld iscsi --op new --mode target --tid 1 -T iqn.qemu.test
1053 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 \
1054 -b /IMAGES/disk.img --device-type=disk
1055 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 \
1056 -b /IMAGES/cd.iso --device-type=cd
1057 tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL
1059 qemu-system-i386 -iscsi initiator-name=iqn.qemu.test:my-initiator \
1060 -boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1061 -cdrom iscsi://127.0.0.1/iqn.qemu.test/2
1064 @node disk_images_gluster
1065 @subsection GlusterFS disk images
1067 GlusterFS is an user space distributed file system.
1069 You can boot from the GlusterFS disk image with the command:
1071 qemu-system-x86_64 -drive file=gluster[+@var{transport}]://[@var{server}[:@var{port}]]/@var{volname}/@var{image}[?socket=...]
1074 @var{gluster} is the protocol.
1076 @var{transport} specifies the transport type used to connect to gluster
1077 management daemon (glusterd). Valid transport types are
1078 tcp, unix and rdma. If a transport type isn't specified, then tcp
1081 @var{server} specifies the server where the volume file specification for
1082 the given volume resides. This can be either hostname, ipv4 address
1083 or ipv6 address. ipv6 address needs to be within square brackets [ ].
1084 If transport type is unix, then @var{server} field should not be specified.
1085 Instead @var{socket} field needs to be populated with the path to unix domain
1088 @var{port} is the port number on which glusterd is listening. This is optional
1089 and if not specified, QEMU will send 0 which will make gluster to use the
1090 default port. If the transport type is unix, then @var{port} should not be
1093 @var{volname} is the name of the gluster volume which contains the disk image.
1095 @var{image} is the path to the actual disk image that resides on gluster volume.
1097 You can create a GlusterFS disk image with the command:
1099 qemu-img create gluster://@var{server}/@var{volname}/@var{image} @var{size}
1104 qemu-system-x86_64 -drive file=gluster://1.2.3.4/testvol/a.img
1105 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4/testvol/a.img
1106 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img
1107 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
1108 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img
1109 qemu-system-x86_64 -drive file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img
1110 qemu-system-x86_64 -drive file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
1111 qemu-system-x86_64 -drive file=gluster+rdma://1.2.3.4:24007/testvol/a.img
1114 @node disk_images_ssh
1115 @subsection Secure Shell (ssh) disk images
1117 You can access disk images located on a remote ssh server
1118 by using the ssh protocol:
1121 qemu-system-x86_64 -drive file=ssh://[@var{user}@@]@var{server}[:@var{port}]/@var{path}[?host_key_check=@var{host_key_check}]
1124 Alternative syntax using properties:
1127 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}]
1130 @var{ssh} is the protocol.
1132 @var{user} is the remote user. If not specified, then the local
1135 @var{server} specifies the remote ssh server. Any ssh server can be
1136 used, but it must implement the sftp-server protocol. Most Unix/Linux
1137 systems should work without requiring any extra configuration.
1139 @var{port} is the port number on which sshd is listening. By default
1140 the standard ssh port (22) is used.
1142 @var{path} is the path to the disk image.
1144 The optional @var{host_key_check} parameter controls how the remote
1145 host's key is checked. The default is @code{yes} which means to use
1146 the local @file{.ssh/known_hosts} file. Setting this to @code{no}
1147 turns off known-hosts checking. Or you can check that the host key
1148 matches a specific fingerprint:
1149 @code{host_key_check=md5:78:45:8e:14:57:4f:d5:45:83:0a:0e:f3:49:82:c9:c8}
1150 (@code{sha1:} can also be used as a prefix, but note that OpenSSH
1151 tools only use MD5 to print fingerprints).
1153 Currently authentication must be done using ssh-agent. Other
1154 authentication methods may be supported in future.
1156 Note: Many ssh servers do not support an @code{fsync}-style operation.
1157 The ssh driver cannot guarantee that disk flush requests are
1158 obeyed, and this causes a risk of disk corruption if the remote
1159 server or network goes down during writes. The driver will
1160 print a warning when @code{fsync} is not supported:
1162 warning: ssh server @code{ssh.example.com:22} does not support fsync
1164 With sufficiently new versions of libssh2 and OpenSSH, @code{fsync} is
1168 @section Network emulation
1170 QEMU can simulate several network cards (PCI or ISA cards on the PC
1171 target) and can connect them to an arbitrary number of Virtual Local
1172 Area Networks (VLANs). Host TAP devices can be connected to any QEMU
1173 VLAN. VLAN can be connected between separate instances of QEMU to
1174 simulate large networks. For simpler usage, a non privileged user mode
1175 network stack can replace the TAP device to have a basic network
1180 QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
1181 connection between several network devices. These devices can be for
1182 example QEMU virtual Ethernet cards or virtual Host ethernet devices
1185 @subsection Using TAP network interfaces
1187 This is the standard way to connect QEMU to a real network. QEMU adds
1188 a virtual network device on your host (called @code{tapN}), and you
1189 can then configure it as if it was a real ethernet card.
1191 @subsubsection Linux host
1193 As an example, you can download the @file{linux-test-xxx.tar.gz}
1194 archive and copy the script @file{qemu-ifup} in @file{/etc} and
1195 configure properly @code{sudo} so that the command @code{ifconfig}
1196 contained in @file{qemu-ifup} can be executed as root. You must verify
1197 that your host kernel supports the TAP network interfaces: the
1198 device @file{/dev/net/tun} must be present.
1200 See @ref{sec_invocation} to have examples of command lines using the
1201 TAP network interfaces.
1203 @subsubsection Windows host
1205 There is a virtual ethernet driver for Windows 2000/XP systems, called
1206 TAP-Win32. But it is not included in standard QEMU for Windows,
1207 so you will need to get it separately. It is part of OpenVPN package,
1208 so download OpenVPN from : @url{http://openvpn.net/}.
1210 @subsection Using the user mode network stack
1212 By using the option @option{-net user} (default configuration if no
1213 @option{-net} option is specified), QEMU uses a completely user mode
1214 network stack (you don't need root privilege to use the virtual
1215 network). The virtual network configuration is the following:
1219 QEMU VLAN <------> Firewall/DHCP server <-----> Internet
1222 ----> DNS server (10.0.2.3)
1224 ----> SMB server (10.0.2.4)
1227 The QEMU VM behaves as if it was behind a firewall which blocks all
1228 incoming connections. You can use a DHCP client to automatically
1229 configure the network in the QEMU VM. The DHCP server assign addresses
1230 to the hosts starting from 10.0.2.15.
1232 In order to check that the user mode network is working, you can ping
1233 the address 10.0.2.2 and verify that you got an address in the range
1234 10.0.2.x from the QEMU virtual DHCP server.
1236 Note that ICMP traffic in general does not work with user mode networking.
1237 @code{ping}, aka. ICMP echo, to the local router (10.0.2.2) shall work,
1238 however. If you're using QEMU on Linux >= 3.0, it can use unprivileged ICMP
1239 ping sockets to allow @code{ping} to the Internet. The host admin has to set
1240 the ping_group_range in order to grant access to those sockets. To allow ping
1241 for GID 100 (usually users group):
1244 echo 100 100 > /proc/sys/net/ipv4/ping_group_range
1247 When using the built-in TFTP server, the router is also the TFTP
1250 When using the @option{'-netdev user,hostfwd=...'} option, TCP or UDP
1251 connections can be redirected from the host to the guest. It allows for
1252 example to redirect X11, telnet or SSH connections.
1254 @subsection Connecting VLANs between QEMU instances
1256 Using the @option{-net socket} option, it is possible to make VLANs
1257 that span several QEMU instances. See @ref{sec_invocation} to have a
1260 @node pcsys_other_devs
1261 @section Other Devices
1263 @subsection Inter-VM Shared Memory device
1265 With KVM enabled on a Linux host, a shared memory device is available. Guests
1266 map a POSIX shared memory region into the guest as a PCI device that enables
1267 zero-copy communication to the application level of the guests. The basic
1271 qemu-system-i386 -device ivshmem,size=@var{size},shm=@var{shm-name}
1274 If desired, interrupts can be sent between guest VMs accessing the same shared
1275 memory region. Interrupt support requires using a shared memory server and
1276 using a chardev socket to connect to it. The code for the shared memory server
1277 is qemu.git/contrib/ivshmem-server. An example syntax when using the shared
1281 # First start the ivshmem server once and for all
1282 ivshmem-server -p @var{pidfile} -S @var{path} -m @var{shm-name} -l @var{shm-size} -n @var{vectors}
1284 # Then start your qemu instances with matching arguments
1285 qemu-system-i386 -device ivshmem,size=@var{shm-size},vectors=@var{vectors},chardev=@var{id}
1286 [,msi=on][,ioeventfd=on][,role=peer|master]
1287 -chardev socket,path=@var{path},id=@var{id}
1290 When using the server, the guest will be assigned a VM ID (>=0) that allows guests
1291 using the same server to communicate via interrupts. Guests can read their
1292 VM ID from a device register (see ivshmem-spec.txt).
1294 The @option{role} argument can be set to either master or peer and will affect
1295 how the shared memory is migrated. With @option{role=master}, the guest will
1296 copy the shared memory on migration to the destination host. With
1297 @option{role=peer}, the guest will not be able to migrate with the device attached.
1298 With the @option{peer} case, the device should be detached and then reattached
1299 after migration using the PCI hotplug support.
1301 @subsubsection ivshmem and hugepages
1303 Instead of specifying the <shm size> using POSIX shm, you may specify
1304 a memory backend that has hugepage support:
1307 qemu-system-i386 -object memory-backend-file,size=1G,mem-path=/dev/hugepages/my-shmem-file,share,id=mb1
1308 -device ivshmem,x-memdev=mb1
1311 ivshmem-server also supports hugepages mount points with the
1312 @option{-m} memory path argument.
1314 @node direct_linux_boot
1315 @section Direct Linux Boot
1317 This section explains how to launch a Linux kernel inside QEMU without
1318 having to make a full bootable image. It is very useful for fast Linux
1323 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
1326 Use @option{-kernel} to provide the Linux kernel image and
1327 @option{-append} to give the kernel command line arguments. The
1328 @option{-initrd} option can be used to provide an INITRD image.
1330 When using the direct Linux boot, a disk image for the first hard disk
1331 @file{hda} is required because its boot sector is used to launch the
1334 If you do not need graphical output, you can disable it and redirect
1335 the virtual serial port and the QEMU monitor to the console with the
1336 @option{-nographic} option. The typical command line is:
1338 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1339 -append "root=/dev/hda console=ttyS0" -nographic
1342 Use @key{Ctrl-a c} to switch between the serial console and the
1343 monitor (@pxref{pcsys_keys}).
1346 @section USB emulation
1348 QEMU emulates a PCI UHCI USB controller. You can virtually plug
1349 virtual USB devices or real host USB devices (experimental, works only
1350 on Linux hosts). QEMU will automatically create and connect virtual USB hubs
1351 as necessary to connect multiple USB devices.
1355 * host_usb_devices::
1358 @subsection Connecting USB devices
1360 USB devices can be connected with the @option{-usbdevice} commandline option
1361 or the @code{usb_add} monitor command. Available devices are:
1365 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1367 Pointer device that uses absolute coordinates (like a touchscreen).
1368 This means QEMU is able to report the mouse position without having
1369 to grab the mouse. Also overrides the PS/2 mouse emulation when activated.
1370 @item disk:@var{file}
1371 Mass storage device based on @var{file} (@pxref{disk_images})
1372 @item host:@var{bus.addr}
1373 Pass through the host device identified by @var{bus.addr}
1375 @item host:@var{vendor_id:product_id}
1376 Pass through the host device identified by @var{vendor_id:product_id}
1379 Virtual Wacom PenPartner tablet. This device is similar to the @code{tablet}
1380 above but it can be used with the tslib library because in addition to touch
1381 coordinates it reports touch pressure.
1383 Standard USB keyboard. Will override the PS/2 keyboard (if present).
1384 @item serial:[vendorid=@var{vendor_id}][,product_id=@var{product_id}]:@var{dev}
1385 Serial converter. This emulates an FTDI FT232BM chip connected to host character
1386 device @var{dev}. The available character devices are the same as for the
1387 @code{-serial} option. The @code{vendorid} and @code{productid} options can be
1388 used to override the default 0403:6001. For instance,
1390 usb_add serial:productid=FA00:tcp:192.168.0.2:4444
1392 will connect to tcp port 4444 of ip 192.168.0.2, and plug that to the virtual
1393 serial converter, faking a Matrix Orbital LCD Display (USB ID 0403:FA00).
1395 Braille device. This will use BrlAPI to display the braille output on a real
1397 @item net:@var{options}
1398 Network adapter that supports CDC ethernet and RNDIS protocols. @var{options}
1399 specifies NIC options as with @code{-net nic,}@var{options} (see description).
1400 For instance, user-mode networking can be used with
1402 qemu-system-i386 [...OPTIONS...] -net user,vlan=0 -usbdevice net:vlan=0
1404 Currently this cannot be used in machines that support PCI NICs.
1405 @item bt[:@var{hci-type}]
1406 Bluetooth dongle whose type is specified in the same format as with
1407 the @option{-bt hci} option, @pxref{bt-hcis,,allowed HCI types}. If
1408 no type is given, the HCI logic corresponds to @code{-bt hci,vlan=0}.
1409 This USB device implements the USB Transport Layer of HCI. Example
1412 @command{qemu-system-i386} [...@var{OPTIONS}...] @option{-usbdevice} bt:hci,vlan=3 @option{-bt} device:keyboard,vlan=3
1416 @node host_usb_devices
1417 @subsection Using host USB devices on a Linux host
1419 WARNING: this is an experimental feature. QEMU will slow down when
1420 using it. USB devices requiring real time streaming (i.e. USB Video
1421 Cameras) are not supported yet.
1424 @item If you use an early Linux 2.4 kernel, verify that no Linux driver
1425 is actually using the USB device. A simple way to do that is simply to
1426 disable the corresponding kernel module by renaming it from @file{mydriver.o}
1427 to @file{mydriver.o.disabled}.
1429 @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1435 @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:
1437 chown -R myuid /proc/bus/usb
1440 @item Launch QEMU and do in the monitor:
1443 Device 1.2, speed 480 Mb/s
1444 Class 00: USB device 1234:5678, USB DISK
1446 You should see the list of the devices you can use (Never try to use
1447 hubs, it won't work).
1449 @item Add the device in QEMU by using:
1451 usb_add host:1234:5678
1454 Normally the guest OS should report that a new USB device is
1455 plugged. You can use the option @option{-usbdevice} to do the same.
1457 @item Now you can try to use the host USB device in QEMU.
1461 When relaunching QEMU, you may have to unplug and plug again the USB
1462 device to make it work again (this is a bug).
1465 @section VNC security
1467 The VNC server capability provides access to the graphical console
1468 of the guest VM across the network. This has a number of security
1469 considerations depending on the deployment scenarios.
1473 * vnc_sec_password::
1474 * vnc_sec_certificate::
1475 * vnc_sec_certificate_verify::
1476 * vnc_sec_certificate_pw::
1478 * vnc_sec_certificate_sasl::
1479 * vnc_generate_cert::
1483 @subsection Without passwords
1485 The simplest VNC server setup does not include any form of authentication.
1486 For this setup it is recommended to restrict it to listen on a UNIX domain
1487 socket only. For example
1490 qemu-system-i386 [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
1493 This ensures that only users on local box with read/write access to that
1494 path can access the VNC server. To securely access the VNC server from a
1495 remote machine, a combination of netcat+ssh can be used to provide a secure
1498 @node vnc_sec_password
1499 @subsection With passwords
1501 The VNC protocol has limited support for password based authentication. Since
1502 the protocol limits passwords to 8 characters it should not be considered
1503 to provide high security. The password can be fairly easily brute-forced by
1504 a client making repeat connections. For this reason, a VNC server using password
1505 authentication should be restricted to only listen on the loopback interface
1506 or UNIX domain sockets. Password authentication is not supported when operating
1507 in FIPS 140-2 compliance mode as it requires the use of the DES cipher. Password
1508 authentication is requested with the @code{password} option, and then once QEMU
1509 is running the password is set with the monitor. Until the monitor is used to
1510 set the password all clients will be rejected.
1513 qemu-system-i386 [...OPTIONS...] -vnc :1,password -monitor stdio
1514 (qemu) change vnc password
1519 @node vnc_sec_certificate
1520 @subsection With x509 certificates
1522 The QEMU VNC server also implements the VeNCrypt extension allowing use of
1523 TLS for encryption of the session, and x509 certificates for authentication.
1524 The use of x509 certificates is strongly recommended, because TLS on its
1525 own is susceptible to man-in-the-middle attacks. Basic x509 certificate
1526 support provides a secure session, but no authentication. This allows any
1527 client to connect, and provides an encrypted session.
1530 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio
1533 In the above example @code{/etc/pki/qemu} should contain at least three files,
1534 @code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged
1535 users will want to use a private directory, for example @code{$HOME/.pki/qemu}.
1536 NB the @code{server-key.pem} file should be protected with file mode 0600 to
1537 only be readable by the user owning it.
1539 @node vnc_sec_certificate_verify
1540 @subsection With x509 certificates and client verification
1542 Certificates can also provide a means to authenticate the client connecting.
1543 The server will request that the client provide a certificate, which it will
1544 then validate against the CA certificate. This is a good choice if deploying
1545 in an environment with a private internal certificate authority.
1548 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
1552 @node vnc_sec_certificate_pw
1553 @subsection With x509 certificates, client verification and passwords
1555 Finally, the previous method can be combined with VNC password authentication
1556 to provide two layers of authentication for clients.
1559 qemu-system-i386 [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
1560 (qemu) change vnc password
1567 @subsection With SASL authentication
1569 The SASL authentication method is a VNC extension, that provides an
1570 easily extendable, pluggable authentication method. This allows for
1571 integration with a wide range of authentication mechanisms, such as
1572 PAM, GSSAPI/Kerberos, LDAP, SQL databases, one-time keys and more.
1573 The strength of the authentication depends on the exact mechanism
1574 configured. If the chosen mechanism also provides a SSF layer, then
1575 it will encrypt the datastream as well.
1577 Refer to the later docs on how to choose the exact SASL mechanism
1578 used for authentication, but assuming use of one supporting SSF,
1579 then QEMU can be launched with:
1582 qemu-system-i386 [...OPTIONS...] -vnc :1,sasl -monitor stdio
1585 @node vnc_sec_certificate_sasl
1586 @subsection With x509 certificates and SASL authentication
1588 If the desired SASL authentication mechanism does not supported
1589 SSF layers, then it is strongly advised to run it in combination
1590 with TLS and x509 certificates. This provides securely encrypted
1591 data stream, avoiding risk of compromising of the security
1592 credentials. This can be enabled, by combining the 'sasl' option
1593 with the aforementioned TLS + x509 options:
1596 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509,sasl -monitor stdio
1600 @node vnc_generate_cert
1601 @subsection Generating certificates for VNC
1603 The GNU TLS packages provides a command called @code{certtool} which can
1604 be used to generate certificates and keys in PEM format. At a minimum it
1605 is necessary to setup a certificate authority, and issue certificates to
1606 each server. If using certificates for authentication, then each client
1607 will also need to be issued a certificate. The recommendation is for the
1608 server to keep its certificates in either @code{/etc/pki/qemu} or for
1609 unprivileged users in @code{$HOME/.pki/qemu}.
1613 * vnc_generate_server::
1614 * vnc_generate_client::
1616 @node vnc_generate_ca
1617 @subsubsection Setup the Certificate Authority
1619 This step only needs to be performed once per organization / organizational
1620 unit. First the CA needs a private key. This key must be kept VERY secret
1621 and secure. If this key is compromised the entire trust chain of the certificates
1622 issued with it is lost.
1625 # certtool --generate-privkey > ca-key.pem
1628 A CA needs to have a public certificate. For simplicity it can be a self-signed
1629 certificate, or one issue by a commercial certificate issuing authority. To
1630 generate a self-signed certificate requires one core piece of information, the
1631 name of the organization.
1634 # cat > ca.info <<EOF
1635 cn = Name of your organization
1639 # certtool --generate-self-signed \
1640 --load-privkey ca-key.pem
1641 --template ca.info \
1642 --outfile ca-cert.pem
1645 The @code{ca-cert.pem} file should be copied to all servers and clients wishing to utilize
1646 TLS support in the VNC server. The @code{ca-key.pem} must not be disclosed/copied at all.
1648 @node vnc_generate_server
1649 @subsubsection Issuing server certificates
1651 Each server (or host) needs to be issued with a key and certificate. When connecting
1652 the certificate is sent to the client which validates it against the CA certificate.
1653 The core piece of information for a server certificate is the hostname. This should
1654 be the fully qualified hostname that the client will connect with, since the client
1655 will typically also verify the hostname in the certificate. On the host holding the
1656 secure CA private key:
1659 # cat > server.info <<EOF
1660 organization = Name of your organization
1661 cn = server.foo.example.com
1666 # certtool --generate-privkey > server-key.pem
1667 # certtool --generate-certificate \
1668 --load-ca-certificate ca-cert.pem \
1669 --load-ca-privkey ca-key.pem \
1670 --load-privkey server-key.pem \
1671 --template server.info \
1672 --outfile server-cert.pem
1675 The @code{server-key.pem} and @code{server-cert.pem} files should now be securely copied
1676 to the server for which they were generated. The @code{server-key.pem} is security
1677 sensitive and should be kept protected with file mode 0600 to prevent disclosure.
1679 @node vnc_generate_client
1680 @subsubsection Issuing client certificates
1682 If the QEMU VNC server is to use the @code{x509verify} option to validate client
1683 certificates as its authentication mechanism, each client also needs to be issued
1684 a certificate. The client certificate contains enough metadata to uniquely identify
1685 the client, typically organization, state, city, building, etc. On the host holding
1686 the secure CA private key:
1689 # cat > client.info <<EOF
1693 organization = Name of your organization
1694 cn = client.foo.example.com
1699 # certtool --generate-privkey > client-key.pem
1700 # certtool --generate-certificate \
1701 --load-ca-certificate ca-cert.pem \
1702 --load-ca-privkey ca-key.pem \
1703 --load-privkey client-key.pem \
1704 --template client.info \
1705 --outfile client-cert.pem
1708 The @code{client-key.pem} and @code{client-cert.pem} files should now be securely
1709 copied to the client for which they were generated.
1712 @node vnc_setup_sasl
1714 @subsection Configuring SASL mechanisms
1716 The following documentation assumes use of the Cyrus SASL implementation on a
1717 Linux host, but the principals should apply to any other SASL impl. When SASL
1718 is enabled, the mechanism configuration will be loaded from system default
1719 SASL service config /etc/sasl2/qemu.conf. If running QEMU as an
1720 unprivileged user, an environment variable SASL_CONF_PATH can be used
1721 to make it search alternate locations for the service config.
1723 The default configuration might contain
1726 mech_list: digest-md5
1727 sasldb_path: /etc/qemu/passwd.db
1730 This says to use the 'Digest MD5' mechanism, which is similar to the HTTP
1731 Digest-MD5 mechanism. The list of valid usernames & passwords is maintained
1732 in the /etc/qemu/passwd.db file, and can be updated using the saslpasswd2
1733 command. While this mechanism is easy to configure and use, it is not
1734 considered secure by modern standards, so only suitable for developers /
1737 A more serious deployment might use Kerberos, which is done with the 'gssapi'
1742 keytab: /etc/qemu/krb5.tab
1745 For this to work the administrator of your KDC must generate a Kerberos
1746 principal for the server, with a name of 'qemu/somehost.example.com@@EXAMPLE.COM'
1747 replacing 'somehost.example.com' with the fully qualified host name of the
1748 machine running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.
1750 Other configurations will be left as an exercise for the reader. It should
1751 be noted that only Digest-MD5 and GSSAPI provides a SSF layer for data
1752 encryption. For all other mechanisms, VNC should always be configured to
1753 use TLS and x509 certificates to protect security credentials from snooping.
1758 QEMU has a primitive support to work with gdb, so that you can do
1759 'Ctrl-C' while the virtual machine is running and inspect its state.
1761 In order to use gdb, launch QEMU with the '-s' option. It will wait for a
1764 qemu-system-i386 -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1765 -append "root=/dev/hda"
1766 Connected to host network interface: tun0
1767 Waiting gdb connection on port 1234
1770 Then launch gdb on the 'vmlinux' executable:
1775 In gdb, connect to QEMU:
1777 (gdb) target remote localhost:1234
1780 Then you can use gdb normally. For example, type 'c' to launch the kernel:
1785 Here are some useful tips in order to use gdb on system code:
1789 Use @code{info reg} to display all the CPU registers.
1791 Use @code{x/10i $eip} to display the code at the PC position.
1793 Use @code{set architecture i8086} to dump 16 bit code. Then use
1794 @code{x/10i $cs*16+$eip} to dump the code at the PC position.
1797 Advanced debugging options:
1799 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:
1801 @item maintenance packet qqemu.sstepbits
1803 This will display the MASK bits used to control the single stepping IE:
1805 (gdb) maintenance packet qqemu.sstepbits
1806 sending: "qqemu.sstepbits"
1807 received: "ENABLE=1,NOIRQ=2,NOTIMER=4"
1809 @item maintenance packet qqemu.sstep
1811 This will display the current value of the mask used when single stepping IE:
1813 (gdb) maintenance packet qqemu.sstep
1814 sending: "qqemu.sstep"
1817 @item maintenance packet Qqemu.sstep=HEX_VALUE
1819 This will change the single step mask, so if wanted to enable IRQs on the single step, but not timers, you would use:
1821 (gdb) maintenance packet Qqemu.sstep=0x5
1822 sending: "qemu.sstep=0x5"
1827 @node pcsys_os_specific
1828 @section Target OS specific information
1832 To have access to SVGA graphic modes under X11, use the @code{vesa} or
1833 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1834 color depth in the guest and the host OS.
1836 When using a 2.6 guest Linux kernel, you should add the option
1837 @code{clock=pit} on the kernel command line because the 2.6 Linux
1838 kernels make very strict real time clock checks by default that QEMU
1839 cannot simulate exactly.
1841 When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1842 not activated because QEMU is slower with this patch. The QEMU
1843 Accelerator Module is also much slower in this case. Earlier Fedora
1844 Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this
1845 patch by default. Newer kernels don't have it.
1849 If you have a slow host, using Windows 95 is better as it gives the
1850 best speed. Windows 2000 is also a good choice.
1852 @subsubsection SVGA graphic modes support
1854 QEMU emulates a Cirrus Logic GD5446 Video
1855 card. All Windows versions starting from Windows 95 should recognize
1856 and use this graphic card. For optimal performances, use 16 bit color
1857 depth in the guest and the host OS.
1859 If you are using Windows XP as guest OS and if you want to use high
1860 resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
1861 1280x1024x16), then you should use the VESA VBE virtual graphic card
1862 (option @option{-std-vga}).
1864 @subsubsection CPU usage reduction
1866 Windows 9x does not correctly use the CPU HLT
1867 instruction. The result is that it takes host CPU cycles even when
1868 idle. You can install the utility from
1869 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
1870 problem. Note that no such tool is needed for NT, 2000 or XP.
1872 @subsubsection Windows 2000 disk full problem
1874 Windows 2000 has a bug which gives a disk full problem during its
1875 installation. When installing it, use the @option{-win2k-hack} QEMU
1876 option to enable a specific workaround. After Windows 2000 is
1877 installed, you no longer need this option (this option slows down the
1880 @subsubsection Windows 2000 shutdown
1882 Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1883 can. It comes from the fact that Windows 2000 does not automatically
1884 use the APM driver provided by the BIOS.
1886 In order to correct that, do the following (thanks to Struan
1887 Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1888 Add/Troubleshoot a device => Add a new device & Next => No, select the
1889 hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1890 (again) a few times. Now the driver is installed and Windows 2000 now
1891 correctly instructs QEMU to shutdown at the appropriate moment.
1893 @subsubsection Share a directory between Unix and Windows
1895 See @ref{sec_invocation} about the help of the option
1896 @option{'-netdev user,smb=...'}.
1898 @subsubsection Windows XP security problem
1900 Some releases of Windows XP install correctly but give a security
1903 A problem is preventing Windows from accurately checking the
1904 license for this computer. Error code: 0x800703e6.
1907 The workaround is to install a service pack for XP after a boot in safe
1908 mode. Then reboot, and the problem should go away. Since there is no
1909 network while in safe mode, its recommended to download the full
1910 installation of SP1 or SP2 and transfer that via an ISO or using the
1911 vvfat block device ("-hdb fat:directory_which_holds_the_SP").
1913 @subsection MS-DOS and FreeDOS
1915 @subsubsection CPU usage reduction
1917 DOS does not correctly use the CPU HLT instruction. The result is that
1918 it takes host CPU cycles even when idle. You can install the utility
1919 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1922 @node QEMU System emulator for non PC targets
1923 @chapter QEMU System emulator for non PC targets
1925 QEMU is a generic emulator and it emulates many non PC
1926 machines. Most of the options are similar to the PC emulator. The
1927 differences are mentioned in the following sections.
1930 * PowerPC System emulator::
1931 * Sparc32 System emulator::
1932 * Sparc64 System emulator::
1933 * MIPS System emulator::
1934 * ARM System emulator::
1935 * ColdFire System emulator::
1936 * Cris System emulator::
1937 * Microblaze System emulator::
1938 * SH4 System emulator::
1939 * Xtensa System emulator::
1942 @node PowerPC System emulator
1943 @section PowerPC System emulator
1944 @cindex system emulation (PowerPC)
1946 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1947 or PowerMac PowerPC system.
1949 QEMU emulates the following PowerMac peripherals:
1953 UniNorth or Grackle PCI Bridge
1955 PCI VGA compatible card with VESA Bochs Extensions
1957 2 PMAC IDE interfaces with hard disk and CD-ROM support
1963 VIA-CUDA with ADB keyboard and mouse.
1966 QEMU emulates the following PREP peripherals:
1972 PCI VGA compatible card with VESA Bochs Extensions
1974 2 IDE interfaces with hard disk and CD-ROM support
1978 NE2000 network adapters
1982 PREP Non Volatile RAM
1984 PC compatible keyboard and mouse.
1987 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
1988 @url{http://perso.magic.fr/l_indien/OpenHackWare/index.htm}.
1990 Since version 0.9.1, QEMU uses OpenBIOS @url{http://www.openbios.org/}
1991 for the g3beige and mac99 PowerMac machines. OpenBIOS is a free (GPL
1992 v2) portable firmware implementation. The goal is to implement a 100%
1993 IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.
1995 @c man begin OPTIONS
1997 The following options are specific to the PowerPC emulation:
2001 @item -g @var{W}x@var{H}[x@var{DEPTH}]
2003 Set the initial VGA graphic mode. The default is 800x600x32.
2005 @item -prom-env @var{string}
2007 Set OpenBIOS variables in NVRAM, for example:
2010 qemu-system-ppc -prom-env 'auto-boot?=false' \
2011 -prom-env 'boot-device=hd:2,\yaboot' \
2012 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
2015 These variables are not used by Open Hack'Ware.
2022 More information is available at
2023 @url{http://perso.magic.fr/l_indien/qemu-ppc/}.
2025 @node Sparc32 System emulator
2026 @section Sparc32 System emulator
2027 @cindex system emulation (Sparc32)
2029 Use the executable @file{qemu-system-sparc} to simulate the following
2030 Sun4m architecture machines:
2045 SPARCstation Voyager
2052 The emulation is somewhat complete. SMP up to 16 CPUs is supported,
2053 but Linux limits the number of usable CPUs to 4.
2055 QEMU emulates the following sun4m peripherals:
2061 TCX or cgthree Frame buffer
2063 Lance (Am7990) Ethernet
2065 Non Volatile RAM M48T02/M48T08
2067 Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
2068 and power/reset logic
2070 ESP SCSI controller with hard disk and CD-ROM support
2072 Floppy drive (not on SS-600MP)
2074 CS4231 sound device (only on SS-5, not working yet)
2077 The number of peripherals is fixed in the architecture. Maximum
2078 memory size depends on the machine type, for SS-5 it is 256MB and for
2081 Since version 0.8.2, QEMU uses OpenBIOS
2082 @url{http://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
2083 firmware implementation. The goal is to implement a 100% IEEE
2084 1275-1994 (referred to as Open Firmware) compliant firmware.
2086 A sample Linux 2.6 series kernel and ram disk image are available on
2087 the QEMU web site. There are still issues with NetBSD and OpenBSD, but
2088 most kernel versions work. Please note that currently older Solaris kernels
2089 don't work probably due to interface issues between OpenBIOS and
2092 @c man begin OPTIONS
2094 The following options are specific to the Sparc32 emulation:
2098 @item -g @var{W}x@var{H}x[x@var{DEPTH}]
2100 Set the initial graphics mode. For TCX, the default is 1024x768x8 with the
2101 option of 1024x768x24. For cgthree, the default is 1024x768x8 with the option
2102 of 1152x900x8 for people who wish to use OBP.
2104 @item -prom-env @var{string}
2106 Set OpenBIOS variables in NVRAM, for example:
2109 qemu-system-sparc -prom-env 'auto-boot?=false' \
2110 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
2113 @item -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic] [|SPARCbook]
2115 Set the emulated machine type. Default is SS-5.
2121 @node Sparc64 System emulator
2122 @section Sparc64 System emulator
2123 @cindex system emulation (Sparc64)
2125 Use the executable @file{qemu-system-sparc64} to simulate a Sun4u
2126 (UltraSPARC PC-like machine), Sun4v (T1 PC-like machine), or generic
2127 Niagara (T1) machine. The Sun4u emulator is mostly complete, being
2128 able to run Linux, NetBSD and OpenBSD in headless (-nographic) mode. The
2129 Sun4v and Niagara emulators are still a work in progress.
2131 QEMU emulates the following peripherals:
2135 UltraSparc IIi APB PCI Bridge
2137 PCI VGA compatible card with VESA Bochs Extensions
2139 PS/2 mouse and keyboard
2141 Non Volatile RAM M48T59
2143 PC-compatible serial ports
2145 2 PCI IDE interfaces with hard disk and CD-ROM support
2150 @c man begin OPTIONS
2152 The following options are specific to the Sparc64 emulation:
2156 @item -prom-env @var{string}
2158 Set OpenBIOS variables in NVRAM, for example:
2161 qemu-system-sparc64 -prom-env 'auto-boot?=false'
2164 @item -M [sun4u|sun4v|Niagara]
2166 Set the emulated machine type. The default is sun4u.
2172 @node MIPS System emulator
2173 @section MIPS System emulator
2174 @cindex system emulation (MIPS)
2176 Four executables cover simulation of 32 and 64-bit MIPS systems in
2177 both endian options, @file{qemu-system-mips}, @file{qemu-system-mipsel}
2178 @file{qemu-system-mips64} and @file{qemu-system-mips64el}.
2179 Five different machine types are emulated:
2183 A generic ISA PC-like machine "mips"
2185 The MIPS Malta prototype board "malta"
2187 An ACER Pica "pica61". This machine needs the 64-bit emulator.
2189 MIPS emulator pseudo board "mipssim"
2191 A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator.
2194 The generic emulation is supported by Debian 'Etch' and is able to
2195 install Debian into a virtual disk image. The following devices are
2200 A range of MIPS CPUs, default is the 24Kf
2202 PC style serial port
2209 The Malta emulation supports the following devices:
2213 Core board with MIPS 24Kf CPU and Galileo system controller
2215 PIIX4 PCI/USB/SMbus controller
2217 The Multi-I/O chip's serial device
2219 PCI network cards (PCnet32 and others)
2221 Malta FPGA serial device
2223 Cirrus (default) or any other PCI VGA graphics card
2226 The ACER Pica emulation supports:
2232 PC-style IRQ and DMA controllers
2239 The mipssim pseudo board emulation provides an environment similar
2240 to what the proprietary MIPS emulator uses for running Linux.
2245 A range of MIPS CPUs, default is the 24Kf
2247 PC style serial port
2249 MIPSnet network emulation
2252 The MIPS Magnum R4000 emulation supports:
2258 PC-style IRQ controller
2268 @node ARM System emulator
2269 @section ARM System emulator
2270 @cindex system emulation (ARM)
2272 Use the executable @file{qemu-system-arm} to simulate a ARM
2273 machine. The ARM Integrator/CP board is emulated with the following
2278 ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU
2282 SMC 91c111 Ethernet adapter
2284 PL110 LCD controller
2286 PL050 KMI with PS/2 keyboard and mouse.
2288 PL181 MultiMedia Card Interface with SD card.
2291 The ARM Versatile baseboard is emulated with the following devices:
2295 ARM926E, ARM1136 or Cortex-A8 CPU
2297 PL190 Vectored Interrupt Controller
2301 SMC 91c111 Ethernet adapter
2303 PL110 LCD controller
2305 PL050 KMI with PS/2 keyboard and mouse.
2307 PCI host bridge. Note the emulated PCI bridge only provides access to
2308 PCI memory space. It does not provide access to PCI IO space.
2309 This means some devices (eg. ne2k_pci NIC) are not usable, and others
2310 (eg. rtl8139 NIC) are only usable when the guest drivers use the memory
2311 mapped control registers.
2313 PCI OHCI USB controller.
2315 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
2317 PL181 MultiMedia Card Interface with SD card.
2320 Several variants of the ARM RealView baseboard are emulated,
2321 including the EB, PB-A8 and PBX-A9. Due to interactions with the
2322 bootloader, only certain Linux kernel configurations work out
2323 of the box on these boards.
2325 Kernels for the PB-A8 board should have CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2326 enabled in the kernel, and expect 512M RAM. Kernels for The PBX-A9 board
2327 should have CONFIG_SPARSEMEM enabled, CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2328 disabled and expect 1024M RAM.
2330 The following devices are emulated:
2334 ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU
2336 ARM AMBA Generic/Distributed Interrupt Controller
2340 SMC 91c111 or SMSC LAN9118 Ethernet adapter
2342 PL110 LCD controller
2344 PL050 KMI with PS/2 keyboard and mouse
2348 PCI OHCI USB controller
2350 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
2352 PL181 MultiMedia Card Interface with SD card.
2355 The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
2356 and "Terrier") emulation includes the following peripherals:
2360 Intel PXA270 System-on-chip (ARM V5TE core)
2364 IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
2366 On-chip OHCI USB controller
2368 On-chip LCD controller
2370 On-chip Real Time Clock
2372 TI ADS7846 touchscreen controller on SSP bus
2374 Maxim MAX1111 analog-digital converter on I@math{^2}C bus
2376 GPIO-connected keyboard controller and LEDs
2378 Secure Digital card connected to PXA MMC/SD host
2382 WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
2385 The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the
2390 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2392 ROM and RAM memories (ROM firmware image can be loaded with -option-rom)
2394 On-chip LCD controller
2396 On-chip Real Time Clock
2398 TI TSC2102i touchscreen controller / analog-digital converter / Audio
2399 CODEC, connected through MicroWire and I@math{^2}S busses
2401 GPIO-connected matrix keypad
2403 Secure Digital card connected to OMAP MMC/SD host
2408 Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48)
2409 emulation supports the following elements:
2413 Texas Instruments OMAP2420 System-on-chip (ARM 1136 core)
2415 RAM and non-volatile OneNAND Flash memories
2417 Display connected to EPSON remote framebuffer chip and OMAP on-chip
2418 display controller and a LS041y3 MIPI DBI-C controller
2420 TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers
2421 driven through SPI bus
2423 National Semiconductor LM8323-controlled qwerty keyboard driven
2424 through I@math{^2}C bus
2426 Secure Digital card connected to OMAP MMC/SD host
2428 Three OMAP on-chip UARTs and on-chip STI debugging console
2430 A Bluetooth(R) transceiver and HCI connected to an UART
2432 Mentor Graphics "Inventra" dual-role USB controller embedded in a TI
2433 TUSB6010 chip - only USB host mode is supported
2435 TI TMP105 temperature sensor driven through I@math{^2}C bus
2437 TI TWL92230C power management companion with an RTC on I@math{^2}C bus
2439 Nokia RETU and TAHVO multi-purpose chips with an RTC, connected
2443 The Luminary Micro Stellaris LM3S811EVB emulation includes the following
2450 64k Flash and 8k SRAM.
2452 Timers, UARTs, ADC and I@math{^2}C interface.
2454 OSRAM Pictiva 96x16 OLED with SSD0303 controller on I@math{^2}C bus.
2457 The Luminary Micro Stellaris LM3S6965EVB emulation includes the following
2464 256k Flash and 64k SRAM.
2466 Timers, UARTs, ADC, I@math{^2}C and SSI interfaces.
2468 OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI.
2471 The Freecom MusicPal internet radio emulation includes the following
2476 Marvell MV88W8618 ARM core.
2478 32 MB RAM, 256 KB SRAM, 8 MB flash.
2482 MV88W8xx8 Ethernet controller
2484 MV88W8618 audio controller, WM8750 CODEC and mixer
2486 128×64 display with brightness control
2488 2 buttons, 2 navigation wheels with button function
2491 The Siemens SX1 models v1 and v2 (default) basic emulation.
2492 The emulation includes the following elements:
2496 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2498 ROM and RAM memories (ROM firmware image can be loaded with -pflash)
2500 1 Flash of 16MB and 1 Flash of 8MB
2504 On-chip LCD controller
2506 On-chip Real Time Clock
2508 Secure Digital card connected to OMAP MMC/SD host
2513 A Linux 2.6 test image is available on the QEMU web site. More
2514 information is available in the QEMU mailing-list archive.
2516 @c man begin OPTIONS
2518 The following options are specific to the ARM emulation:
2523 Enable semihosting syscall emulation.
2525 On ARM this implements the "Angel" interface.
2527 Note that this allows guest direct access to the host filesystem,
2528 so should only be used with trusted guest OS.
2532 @node ColdFire System emulator
2533 @section ColdFire System emulator
2534 @cindex system emulation (ColdFire)
2535 @cindex system emulation (M68K)
2537 Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2538 The emulator is able to boot a uClinux kernel.
2540 The M5208EVB emulation includes the following devices:
2544 MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2546 Three Two on-chip UARTs.
2548 Fast Ethernet Controller (FEC)
2551 The AN5206 emulation includes the following devices:
2555 MCF5206 ColdFire V2 Microprocessor.
2560 @c man begin OPTIONS
2562 The following options are specific to the ColdFire emulation:
2567 Enable semihosting syscall emulation.
2569 On M68K this implements the "ColdFire GDB" interface used by libgloss.
2571 Note that this allows guest direct access to the host filesystem,
2572 so should only be used with trusted guest OS.
2576 @node Cris System emulator
2577 @section Cris System emulator
2578 @cindex system emulation (Cris)
2582 @node Microblaze System emulator
2583 @section Microblaze System emulator
2584 @cindex system emulation (Microblaze)
2588 @node SH4 System emulator
2589 @section SH4 System emulator
2590 @cindex system emulation (SH4)
2594 @node Xtensa System emulator
2595 @section Xtensa System emulator
2596 @cindex system emulation (Xtensa)
2598 Two executables cover simulation of both Xtensa endian options,
2599 @file{qemu-system-xtensa} and @file{qemu-system-xtensaeb}.
2600 Two different machine types are emulated:
2604 Xtensa emulator pseudo board "sim"
2606 Avnet LX60/LX110/LX200 board
2609 The sim pseudo board emulation provides an environment similar
2610 to one provided by the proprietary Tensilica ISS.
2615 A range of Xtensa CPUs, default is the DC232B
2617 Console and filesystem access via semihosting calls
2620 The Avnet LX60/LX110/LX200 emulation supports:
2624 A range of Xtensa CPUs, default is the DC232B
2628 OpenCores 10/100 Mbps Ethernet MAC
2631 @c man begin OPTIONS
2633 The following options are specific to the Xtensa emulation:
2638 Enable semihosting syscall emulation.
2640 Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select.
2641 Tensilica baremetal libc for ISS and linux platform "sim" use this interface.
2643 Note that this allows guest direct access to the host filesystem,
2644 so should only be used with trusted guest OS.
2647 @node QEMU User space emulator
2648 @chapter QEMU User space emulator
2651 * Supported Operating Systems ::
2652 * Linux User space emulator::
2653 * BSD User space emulator ::
2656 @node Supported Operating Systems
2657 @section Supported Operating Systems
2659 The following OS are supported in user space emulation:
2663 Linux (referred as qemu-linux-user)
2665 BSD (referred as qemu-bsd-user)
2668 @node Linux User space emulator
2669 @section Linux User space emulator
2674 * Command line options::
2679 @subsection Quick Start
2681 In order to launch a Linux process, QEMU needs the process executable
2682 itself and all the target (x86) dynamic libraries used by it.
2686 @item On x86, you can just try to launch any process by using the native
2690 qemu-i386 -L / /bin/ls
2693 @code{-L /} tells that the x86 dynamic linker must be searched with a
2696 @item Since QEMU is also a linux process, you can launch QEMU with
2697 QEMU (NOTE: you can only do that if you compiled QEMU from the sources):
2700 qemu-i386 -L / qemu-i386 -L / /bin/ls
2703 @item On non x86 CPUs, you need first to download at least an x86 glibc
2704 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2705 @code{LD_LIBRARY_PATH} is not set:
2708 unset LD_LIBRARY_PATH
2711 Then you can launch the precompiled @file{ls} x86 executable:
2714 qemu-i386 tests/i386/ls
2716 You can look at @file{scripts/qemu-binfmt-conf.sh} so that
2717 QEMU is automatically launched by the Linux kernel when you try to
2718 launch x86 executables. It requires the @code{binfmt_misc} module in the
2721 @item The x86 version of QEMU is also included. You can try weird things such as:
2723 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2724 /usr/local/qemu-i386/bin/ls-i386
2730 @subsection Wine launch
2734 @item Ensure that you have a working QEMU with the x86 glibc
2735 distribution (see previous section). In order to verify it, you must be
2739 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2742 @item Download the binary x86 Wine install
2743 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2745 @item Configure Wine on your account. Look at the provided script
2746 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2747 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2749 @item Then you can try the example @file{putty.exe}:
2752 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2753 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2758 @node Command line options
2759 @subsection Command line options
2762 @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}...]
2769 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2771 Set the x86 stack size in bytes (default=524288)
2773 Select CPU model (-cpu help for list and additional feature selection)
2774 @item -E @var{var}=@var{value}
2775 Set environment @var{var} to @var{value}.
2777 Remove @var{var} from the environment.
2779 Offset guest address by the specified number of bytes. This is useful when
2780 the address region required by guest applications is reserved on the host.
2781 This option is currently only supported on some hosts.
2783 Pre-allocate a guest virtual address space of the given size (in bytes).
2784 "G", "M", and "k" suffixes may be used when specifying the size.
2791 Activate logging of the specified items (use '-d help' for a list of log items)
2793 Act as if the host page size was 'pagesize' bytes
2795 Wait gdb connection to port
2797 Run the emulation in single step mode.
2800 Environment variables:
2804 Print system calls and arguments similar to the 'strace' program
2805 (NOTE: the actual 'strace' program will not work because the user
2806 space emulator hasn't implemented ptrace). At the moment this is
2807 incomplete. All system calls that don't have a specific argument
2808 format are printed with information for six arguments. Many
2809 flag-style arguments don't have decoders and will show up as numbers.
2812 @node Other binaries
2813 @subsection Other binaries
2815 @cindex user mode (Alpha)
2816 @command{qemu-alpha} TODO.
2818 @cindex user mode (ARM)
2819 @command{qemu-armeb} TODO.
2821 @cindex user mode (ARM)
2822 @command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2823 binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2824 configurations), and arm-uclinux bFLT format binaries.
2826 @cindex user mode (ColdFire)
2827 @cindex user mode (M68K)
2828 @command{qemu-m68k} is capable of running semihosted binaries using the BDM
2829 (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2830 coldfire uClinux bFLT format binaries.
2832 The binary format is detected automatically.
2834 @cindex user mode (Cris)
2835 @command{qemu-cris} TODO.
2837 @cindex user mode (i386)
2838 @command{qemu-i386} TODO.
2839 @command{qemu-x86_64} TODO.
2841 @cindex user mode (Microblaze)
2842 @command{qemu-microblaze} TODO.
2844 @cindex user mode (MIPS)
2845 @command{qemu-mips} TODO.
2846 @command{qemu-mipsel} TODO.
2848 @cindex user mode (PowerPC)
2849 @command{qemu-ppc64abi32} TODO.
2850 @command{qemu-ppc64} TODO.
2851 @command{qemu-ppc} TODO.
2853 @cindex user mode (SH4)
2854 @command{qemu-sh4eb} TODO.
2855 @command{qemu-sh4} TODO.
2857 @cindex user mode (SPARC)
2858 @command{qemu-sparc} can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).
2860 @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2861 (Sparc64 CPU, 32 bit ABI).
2863 @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2864 SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2866 @node BSD User space emulator
2867 @section BSD User space emulator
2872 * BSD Command line options::
2876 @subsection BSD Status
2880 target Sparc64 on Sparc64: Some trivial programs work.
2883 @node BSD Quick Start
2884 @subsection Quick Start
2886 In order to launch a BSD process, QEMU needs the process executable
2887 itself and all the target dynamic libraries used by it.
2891 @item On Sparc64, you can just try to launch any process by using the native
2895 qemu-sparc64 /bin/ls
2900 @node BSD Command line options
2901 @subsection Command line options
2904 @command{qemu-sparc64} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-bsd} @var{type}] @var{program} [@var{arguments}...]
2911 Set the library root path (default=/)
2913 Set the stack size in bytes (default=524288)
2914 @item -ignore-environment
2915 Start with an empty environment. Without this option,
2916 the initial environment is a copy of the caller's environment.
2917 @item -E @var{var}=@var{value}
2918 Set environment @var{var} to @var{value}.
2920 Remove @var{var} from the environment.
2922 Set the type of the emulated BSD Operating system. Valid values are
2923 FreeBSD, NetBSD and OpenBSD (default).
2930 Activate logging of the specified items (use '-d help' for a list of log items)
2932 Act as if the host page size was 'pagesize' bytes
2934 Run the emulation in single step mode.
2938 @chapter Compilation from the sources
2943 * Cross compilation for Windows with Linux::
2951 @subsection Compilation
2953 First you must decompress the sources:
2956 tar zxvf qemu-x.y.z.tar.gz
2960 Then you configure QEMU and build it (usually no options are needed):
2966 Then type as root user:
2970 to install QEMU in @file{/usr/local}.
2976 @item Install the current versions of MSYS and MinGW from
2977 @url{http://www.mingw.org/}. You can find detailed installation
2978 instructions in the download section and the FAQ.
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.
2987 @item Install the MinGW version of zlib and make sure
2988 @file{zlib.h} and @file{libz.dll.a} are in
2989 MinGW's default header and linker search paths.
2991 @item Extract the current version of QEMU.
2993 @item Start the MSYS shell (file @file{msys.bat}).
2995 @item Change to the QEMU directory. Launch @file{./configure} and
2996 @file{make}. If you have problems using SDL, verify that
2997 @file{sdl-config} can be launched from the MSYS command line.
2999 @item You can install QEMU in @file{Program Files/QEMU} by typing
3000 @file{make install}. Don't forget to copy @file{SDL.dll} in
3001 @file{Program Files/QEMU}.
3005 @node Cross compilation for Windows with Linux
3006 @section Cross compilation for Windows with Linux
3010 Install the MinGW cross compilation tools available at
3011 @url{http://www.mingw.org/}.
3014 the MinGW development library of SDL 1.2.x
3015 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
3016 @url{http://www.libsdl.org}. Unpack it in a temporary place and
3017 edit the @file{sdl-config} script so that it gives the
3018 correct SDL directory when invoked. Set up the @code{PATH} environment
3019 variable so that @file{sdl-config} can be launched by
3020 the QEMU configuration script.
3022 @item Install the MinGW version of zlib and make sure
3023 @file{zlib.h} and @file{libz.dll.a} are in
3024 MinGW's default header and linker search paths.
3027 Configure QEMU for Windows cross compilation:
3029 PATH=/usr/i686-pc-mingw32/sys-root/mingw/bin:$PATH ./configure --cross-prefix='i686-pc-mingw32-'
3031 The example assumes @file{sdl-config} is installed under @file{/usr/i686-pc-mingw32/sys-root/mingw/bin} and
3032 MinGW cross compilation tools have names like @file{i686-pc-mingw32-gcc} and @file{i686-pc-mingw32-strip}.
3033 We set the @code{PATH} environment variable to ensure the MinGW version of @file{sdl-config} is used and
3034 use --cross-prefix to specify the name of the cross compiler.
3035 You can also use --prefix to set the Win32 install path which defaults to @file{c:/Program Files/QEMU}.
3037 Under Fedora Linux, you can run:
3039 yum -y install mingw32-gcc mingw32-SDL mingw32-zlib
3041 to get a suitable cross compilation environment.
3043 @item You can install QEMU in the installation directory by typing
3044 @code{make install}. Don't forget to copy @file{SDL.dll} and @file{zlib1.dll} into the
3045 installation directory.
3049 Wine can be used to launch the resulting qemu-system-i386.exe
3050 and all other qemu-system-@var{target}.exe compiled for Win32.
3055 System Requirements:
3057 @item Mac OS 10.5 or higher
3058 @item The clang compiler shipped with Xcode 4.2 or higher,
3059 or GCC 4.3 or higher
3062 Additional Requirements (install in order):
3064 @item libffi: @uref{https://sourceware.org/libffi/}
3065 @item gettext: @uref{http://www.gnu.org/software/gettext/}
3066 @item glib: @uref{http://ftp.gnome.org/pub/GNOME/sources/glib/}
3067 @item pkg-config: @uref{http://www.freedesktop.org/wiki/Software/pkg-config/}
3068 @item autoconf: @uref{http://www.gnu.org/software/autoconf/autoconf.html}
3069 @item automake: @uref{http://www.gnu.org/software/automake/}
3070 @item pixman: @uref{http://www.pixman.org/}
3073 * You may find it easiest to get these from a third-party packager
3074 such as Homebrew, Macports, or Fink.
3076 After downloading the QEMU source code, double-click it to expand it.
3078 Then configure and make QEMU:
3084 If you have a recent version of Mac OS X (OSX 10.7 or better
3085 with Xcode 4.2 or better) we recommend building QEMU with the
3086 default compiler provided by Apple, for your version of Mac OS X
3087 (which will be 'clang'). The configure script will
3088 automatically pick this.
3090 Note: If after the configure step you see a message like this:
3092 ERROR: Your compiler does not support the __thread specifier for
3093 Thread-Local Storage (TLS). Please upgrade to a version that does.
3095 you may have to build your own version of gcc from source. Expect that to take
3096 several hours. More information can be found here:
3097 @uref{https://gcc.gnu.org/install/} @*
3099 These are some of the third party binaries of gcc available for download:
3101 @item Homebrew: @uref{http://brew.sh/}
3102 @item @uref{https://www.litebeam.net/gcc/gcc_472.pkg}
3103 @item @uref{http://www.macports.org/ports.php?by=name&substr=gcc}
3106 You can have several versions of GCC on your system. To specify a certain version,
3107 use the --cc and --cxx options.
3109 ./configure --cxx=<path of your c++ compiler> --cc=<path of your c compiler> <other options>
3113 @section Make targets
3119 Make everything which is typically needed.
3128 Remove most files which were built during make.
3130 @item make distclean
3131 Remove everything which was built during make.
3137 Create documentation in dvi, html, info or pdf format.
3142 @item make defconfig
3143 (Re-)create some build configuration files.
3144 User made changes will be overwritten.
3155 QEMU is a trademark of Fabrice Bellard.
3157 QEMU is released under the GNU General Public License (TODO: add link).
3158 Parts of QEMU have specific licenses, see file LICENSE.
3160 TODO (refer to file LICENSE, include it, include the GPL?)
3174 @section Concept Index
3175 This is the main index. Should we combine all keywords in one index? TODO
3178 @node Function Index
3179 @section Function Index
3180 This index could be used for command line options and monitor functions.
3183 @node Keystroke Index
3184 @section Keystroke Index
3186 This is a list of all keystrokes which have a special function
3187 in system emulation.
3192 @section Program Index
3195 @node Data Type Index
3196 @section Data Type Index
3198 This index could be used for qdev device names and options.
3202 @node Variable Index
3203 @section Variable Index