1 \input texinfo @c -*- texinfo -*-
3 @setfilename qemu-doc.info
6 @documentencoding UTF-8
8 @settitle QEMU Emulator User Documentation
15 * QEMU: (qemu-doc). The QEMU Emulator User Documentation.
22 @center @titlefont{QEMU Emulator}
24 @center @titlefont{User Documentation}
36 * QEMU PC System emulator::
37 * QEMU System emulator for non PC targets::
38 * QEMU User space emulator::
39 * compilation:: Compilation from the sources
51 * intro_features:: Features
57 QEMU is a FAST! processor emulator using dynamic translation to
58 achieve good emulation speed.
60 @cindex operating modes
61 QEMU has two operating modes:
66 @cindex system emulation
67 Full system emulation. In this mode, QEMU emulates a full system (for
68 example a PC), including one or several processors and various
69 peripherals. It can be used to launch different Operating Systems
70 without rebooting the PC or to debug system code.
73 @cindex user mode emulation
74 User mode emulation. In this mode, QEMU can launch
75 processes compiled for one CPU on another CPU. It can be used to
76 launch the Wine Windows API emulator (@url{http://www.winehq.org}) or
77 to ease cross-compilation and cross-debugging.
81 QEMU can run without a host kernel driver and yet gives acceptable
84 For system emulation, the following hardware targets are supported:
86 @cindex emulated target systems
87 @cindex supported target systems
88 @item PC (x86 or x86_64 processor)
89 @item ISA PC (old style PC without PCI bus)
90 @item PREP (PowerPC processor)
91 @item G3 Beige PowerMac (PowerPC processor)
92 @item Mac99 PowerMac (PowerPC processor, in progress)
93 @item Sun4m/Sun4c/Sun4d (32-bit Sparc processor)
94 @item Sun4u/Sun4v (64-bit Sparc processor, in progress)
95 @item Malta board (32-bit and 64-bit MIPS processors)
96 @item MIPS Magnum (64-bit MIPS processor)
97 @item ARM Integrator/CP (ARM)
98 @item ARM Versatile baseboard (ARM)
99 @item ARM RealView Emulation/Platform baseboard (ARM)
100 @item Spitz, Akita, Borzoi, Terrier and Tosa PDAs (PXA270 processor)
101 @item Luminary Micro LM3S811EVB (ARM Cortex-M3)
102 @item Luminary Micro LM3S6965EVB (ARM Cortex-M3)
103 @item Freescale MCF5208EVB (ColdFire V2).
104 @item Arnewsh MCF5206 evaluation board (ColdFire V2).
105 @item Palm Tungsten|E PDA (OMAP310 processor)
106 @item N800 and N810 tablets (OMAP2420 processor)
107 @item MusicPal (MV88W8618 ARM processor)
108 @item Gumstix "Connex" and "Verdex" motherboards (PXA255/270).
109 @item Siemens SX1 smartphone (OMAP310 processor)
110 @item AXIS-Devboard88 (CRISv32 ETRAX-FS).
111 @item Petalogix Spartan 3aDSP1800 MMU ref design (MicroBlaze).
112 @item Avnet LX60/LX110/LX200 boards (Xtensa)
115 @cindex supported user mode targets
116 For user emulation, x86 (32 and 64 bit), PowerPC (32 and 64 bit),
117 ARM, MIPS (32 bit only), Sparc (32 and 64 bit),
118 Alpha, ColdFire(m68k), CRISv32 and MicroBlaze CPUs are supported.
121 @chapter Installation
123 If you want to compile QEMU yourself, see @ref{compilation}.
126 * install_linux:: Linux
127 * install_windows:: Windows
128 * install_mac:: Macintosh
133 @cindex installation (Linux)
135 If a precompiled package is available for your distribution - you just
136 have to install it. Otherwise, see @ref{compilation}.
138 @node install_windows
140 @cindex installation (Windows)
142 Download the experimental binary installer at
143 @url{http://www.free.oszoo.org/@/download.html}.
144 TODO (no longer available)
148 @cindex installation (Mac OS X)
150 Download the experimental binary installer at
151 @url{http://www.free.oszoo.org/@/download.html}.
152 TODO (no longer available)
154 @node QEMU PC System emulator
155 @chapter QEMU PC System emulator
156 @cindex system emulation (PC)
159 * pcsys_introduction:: Introduction
160 * pcsys_quickstart:: Quick Start
161 * sec_invocation:: Invocation
162 * pcsys_keys:: Keys in the graphical frontends
163 * mux_keys:: Keys in the character backend multiplexer
164 * pcsys_monitor:: QEMU Monitor
165 * disk_images:: Disk Images
166 * pcsys_network:: Network emulation
167 * pcsys_other_devs:: Other Devices
168 * direct_linux_boot:: Direct Linux Boot
169 * pcsys_usb:: USB emulation
170 * vnc_security:: VNC security
171 * gdb_usage:: GDB usage
172 * pcsys_os_specific:: Target OS specific information
175 @node pcsys_introduction
176 @section Introduction
178 @c man begin DESCRIPTION
180 The QEMU PC System emulator simulates the
181 following peripherals:
185 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
187 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
188 extensions (hardware level, including all non standard modes).
190 PS/2 mouse and keyboard
192 2 PCI IDE interfaces with hard disk and CD-ROM support
196 PCI and ISA network adapters
200 IPMI BMC, either and internal or external one
202 Creative SoundBlaster 16 sound card
204 ENSONIQ AudioPCI ES1370 sound card
206 Intel 82801AA AC97 Audio compatible sound card
208 Intel HD Audio Controller and HDA codec
210 Adlib (OPL2) - Yamaha YM3812 compatible chip
212 Gravis Ultrasound GF1 sound card
214 CS4231A compatible sound card
216 PCI UHCI USB controller and a virtual USB hub.
219 SMP is supported with up to 255 CPUs.
221 QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs LGPL
224 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
226 QEMU uses GUS emulation (GUSEMU32 @url{http://www.deinmeister.de/gusemu/})
227 by Tibor "TS" Schütz.
229 Note that, by default, GUS shares IRQ(7) with parallel ports and so
230 QEMU must be told to not have parallel ports to have working GUS.
233 qemu-system-i386 dos.img -soundhw gus -parallel none
238 qemu-system-i386 dos.img -device gus,irq=5
241 Or some other unclaimed IRQ.
243 CS4231A is the chip used in Windows Sound System and GUSMAX products
247 @node pcsys_quickstart
251 Download and uncompress the linux image (@file{linux.img}) and type:
254 qemu-system-i386 linux.img
257 Linux should boot and give you a prompt.
263 @c man begin SYNOPSIS
264 @command{qemu-system-i386} [@var{options}] [@var{disk_image}]
269 @var{disk_image} is a raw hard disk image for IDE hard disk 0. Some
270 targets do not need a disk image.
272 @include qemu-options.texi
277 @section Keys in the graphical frontends
281 During the graphical emulation, you can use special key combinations to change
282 modes. The default key mappings are shown below, but if you use @code{-alt-grab}
283 then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use
284 @code{-ctrl-grab} then the modifier is the right Ctrl key (instead of Ctrl-Alt):
301 Restore the screen's un-scaled dimensions
305 Switch to virtual console 'n'. Standard console mappings are:
308 Target system display
317 Toggle mouse and keyboard grab.
323 @kindex Ctrl-PageDown
324 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
325 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
330 @section Keys in the character backend multiplexer
334 During emulation, if you are using a character backend multiplexer
335 (which is the default if you are using @option{-nographic}) then
336 several commands are available via an escape sequence. These
337 key sequences all start with an escape character, which is @key{Ctrl-a}
338 by default, but can be changed with @option{-echr}. The list below assumes
339 you're using the default.
350 Save disk data back to file (if -snapshot)
353 Toggle console timestamps
356 Send break (magic sysrq in Linux)
359 Rotate between the frontends connected to the multiplexer (usually
360 this switches between the monitor and the console)
362 @kindex Ctrl-a Ctrl-a
363 Send the escape character to the frontend
370 The HTML documentation of QEMU for more precise information and Linux
371 user mode emulator invocation.
381 @section QEMU Monitor
384 The QEMU monitor is used to give complex commands to the QEMU
385 emulator. You can use it to:
390 Remove or insert removable media images
391 (such as CD-ROM or floppies).
394 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
397 @item Inspect the VM state without an external debugger.
403 The following commands are available:
405 @include qemu-monitor.texi
407 @include qemu-monitor-info.texi
409 @subsection Integer expressions
411 The monitor understands integers expressions for every integer
412 argument. You can use register names to get the value of specifics
413 CPU registers by prefixing them with @emph{$}.
418 Since version 0.6.1, QEMU supports many disk image formats, including
419 growable disk images (their size increase as non empty sectors are
420 written), compressed and encrypted disk images. Version 0.8.3 added
421 the new qcow2 disk image format which is essential to support VM
425 * disk_images_quickstart:: Quick start for disk image creation
426 * disk_images_snapshot_mode:: Snapshot mode
427 * vm_snapshots:: VM snapshots
428 * qemu_img_invocation:: qemu-img Invocation
429 * qemu_nbd_invocation:: qemu-nbd Invocation
430 * qemu_ga_invocation:: qemu-ga Invocation
431 * disk_images_formats:: Disk image file formats
432 * host_drives:: Using host drives
433 * disk_images_fat_images:: Virtual FAT disk images
434 * disk_images_nbd:: NBD access
435 * disk_images_sheepdog:: Sheepdog disk images
436 * disk_images_iscsi:: iSCSI LUNs
437 * disk_images_gluster:: GlusterFS disk images
438 * disk_images_ssh:: Secure Shell (ssh) disk images
441 @node disk_images_quickstart
442 @subsection Quick start for disk image creation
444 You can create a disk image with the command:
446 qemu-img create myimage.img mysize
448 where @var{myimage.img} is the disk image filename and @var{mysize} is its
449 size in kilobytes. You can add an @code{M} suffix to give the size in
450 megabytes and a @code{G} suffix for gigabytes.
452 See @ref{qemu_img_invocation} for more information.
454 @node disk_images_snapshot_mode
455 @subsection Snapshot mode
457 If you use the option @option{-snapshot}, all disk images are
458 considered as read only. When sectors in written, they are written in
459 a temporary file created in @file{/tmp}. You can however force the
460 write back to the raw disk images by using the @code{commit} monitor
461 command (or @key{C-a s} in the serial console).
464 @subsection VM snapshots
466 VM snapshots are snapshots of the complete virtual machine including
467 CPU state, RAM, device state and the content of all the writable
468 disks. In order to use VM snapshots, you must have at least one non
469 removable and writable block device using the @code{qcow2} disk image
470 format. Normally this device is the first virtual hard drive.
472 Use the monitor command @code{savevm} to create a new VM snapshot or
473 replace an existing one. A human readable name can be assigned to each
474 snapshot in addition to its numerical ID.
476 Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
477 a VM snapshot. @code{info snapshots} lists the available snapshots
478 with their associated information:
481 (qemu) info snapshots
482 Snapshot devices: hda
483 Snapshot list (from hda):
484 ID TAG VM SIZE DATE VM CLOCK
485 1 start 41M 2006-08-06 12:38:02 00:00:14.954
486 2 40M 2006-08-06 12:43:29 00:00:18.633
487 3 msys 40M 2006-08-06 12:44:04 00:00:23.514
490 A VM snapshot is made of a VM state info (its size is shown in
491 @code{info snapshots}) and a snapshot of every writable disk image.
492 The VM state info is stored in the first @code{qcow2} non removable
493 and writable block device. The disk image snapshots are stored in
494 every disk image. The size of a snapshot in a disk image is difficult
495 to evaluate and is not shown by @code{info snapshots} because the
496 associated disk sectors are shared among all the snapshots to save
497 disk space (otherwise each snapshot would need a full copy of all the
500 When using the (unrelated) @code{-snapshot} option
501 (@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
502 but they are deleted as soon as you exit QEMU.
504 VM snapshots currently have the following known limitations:
507 They cannot cope with removable devices if they are removed or
508 inserted after a snapshot is done.
510 A few device drivers still have incomplete snapshot support so their
511 state is not saved or restored properly (in particular USB).
514 @node qemu_img_invocation
515 @subsection @code{qemu-img} Invocation
517 @include qemu-img.texi
519 @node qemu_nbd_invocation
520 @subsection @code{qemu-nbd} Invocation
522 @include qemu-nbd.texi
524 @node qemu_ga_invocation
525 @subsection @code{qemu-ga} Invocation
527 @include qemu-ga.texi
529 @node disk_images_formats
530 @subsection Disk image file formats
532 QEMU supports many image file formats that can be used with VMs as well as with
533 any of the tools (like @code{qemu-img}). This includes the preferred formats
534 raw and qcow2 as well as formats that are supported for compatibility with
535 older QEMU versions or other hypervisors.
537 Depending on the image format, different options can be passed to
538 @code{qemu-img create} and @code{qemu-img convert} using the @code{-o} option.
539 This section describes each format and the options that are supported for it.
544 Raw disk image format. This format has the advantage of
545 being simple and easily exportable to all other emulators. If your
546 file system supports @emph{holes} (for example in ext2 or ext3 on
547 Linux or NTFS on Windows), then only the written sectors will reserve
548 space. Use @code{qemu-img info} to know the real size used by the
549 image or @code{ls -ls} on Unix/Linux.
554 Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}).
555 @code{falloc} mode preallocates space for image by calling posix_fallocate().
556 @code{full} mode preallocates space for image by writing zeros to underlying
561 QEMU image format, the most versatile format. Use it to have smaller
562 images (useful if your filesystem does not supports holes, for example
563 on Windows), zlib based compression and support of multiple VM
569 Determines the qcow2 version to use. @code{compat=0.10} uses the
570 traditional image format that can be read by any QEMU since 0.10.
571 @code{compat=1.1} enables image format extensions that only QEMU 1.1 and
572 newer understand (this is the default). Amongst others, this includes
573 zero clusters, which allow efficient copy-on-read for sparse images.
576 File name of a base image (see @option{create} subcommand)
578 Image format of the base image
580 If this option is set to @code{on}, the image is encrypted with 128-bit AES-CBC.
582 The use of encryption in qcow and qcow2 images is considered to be flawed by
583 modern cryptography standards, suffering from a number of design problems:
586 @item The AES-CBC cipher is used with predictable initialization vectors based
587 on the sector number. This makes it vulnerable to chosen plaintext attacks
588 which can reveal the existence of encrypted data.
589 @item The user passphrase is directly used as the encryption key. A poorly
590 chosen or short passphrase will compromise the security of the encryption.
591 @item In the event of the passphrase being compromised there is no way to
592 change the passphrase to protect data in any qcow images. The files must
593 be cloned, using a different encryption passphrase in the new file. The
594 original file must then be securely erased using a program like shred,
595 though even this is ineffective with many modern storage technologies.
598 Use of qcow / qcow2 encryption with QEMU is deprecated, and support for
599 it will go away in a future release. Users are recommended to use an
600 alternative encryption technology such as the Linux dm-crypt / LUKS
604 Changes the qcow2 cluster size (must be between 512 and 2M). Smaller cluster
605 sizes can improve the image file size whereas larger cluster sizes generally
606 provide better performance.
609 Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
610 @code{full}). An image with preallocated metadata is initially larger but can
611 improve performance when the image needs to grow. @code{falloc} and @code{full}
612 preallocations are like the same options of @code{raw} format, but sets up
616 If this option is set to @code{on}, reference count updates are postponed with
617 the goal of avoiding metadata I/O and improving performance. This is
618 particularly interesting with @option{cache=writethrough} which doesn't batch
619 metadata updates. The tradeoff is that after a host crash, the reference count
620 tables must be rebuilt, i.e. on the next open an (automatic) @code{qemu-img
621 check -r all} is required, which may take some time.
623 This option can only be enabled if @code{compat=1.1} is specified.
626 If this option is set to @code{on}, it will turn off COW of the file. It's only
627 valid on btrfs, no effect on other file systems.
629 Btrfs has low performance when hosting a VM image file, even more when the guest
630 on the VM also using btrfs as file system. Turning off COW is a way to mitigate
631 this bad performance. Generally there are two ways to turn off COW on btrfs:
632 a) Disable it by mounting with nodatacow, then all newly created files will be
633 NOCOW. b) For an empty file, add the NOCOW file attribute. That's what this option
636 Note: this option is only valid to new or empty files. If there is an existing
637 file which is COW and has data blocks already, it couldn't be changed to NOCOW
638 by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if
639 the NOCOW flag is set or not (Capital 'C' is NOCOW flag).
644 Old QEMU image format with support for backing files and compact image files
645 (when your filesystem or transport medium does not support holes).
647 When converting QED images to qcow2, you might want to consider using the
648 @code{lazy_refcounts=on} option to get a more QED-like behaviour.
653 File name of a base image (see @option{create} subcommand).
655 Image file format of backing file (optional). Useful if the format cannot be
656 autodetected because it has no header, like some vhd/vpc files.
658 Changes the cluster size (must be power-of-2 between 4K and 64K). Smaller
659 cluster sizes can improve the image file size whereas larger cluster sizes
660 generally provide better performance.
662 Changes the number of clusters per L1/L2 table (must be power-of-2 between 1
663 and 16). There is normally no need to change this value but this option can be
664 used for performance benchmarking.
668 Old QEMU image format with support for backing files, compact image files,
669 encryption and compression.
674 File name of a base image (see @option{create} subcommand)
676 If this option is set to @code{on}, the image is encrypted.
680 VirtualBox 1.1 compatible image format.
684 If this option is set to @code{on}, the image is created with metadata
689 VMware 3 and 4 compatible image format.
694 File name of a base image (see @option{create} subcommand).
696 Create a VMDK version 6 image (instead of version 4)
698 Specify vmdk virtual hardware version. Compat6 flag cannot be enabled
699 if hwversion is specified.
701 Specifies which VMDK subformat to use. Valid options are
702 @code{monolithicSparse} (default),
703 @code{monolithicFlat},
704 @code{twoGbMaxExtentSparse},
705 @code{twoGbMaxExtentFlat} and
706 @code{streamOptimized}.
710 VirtualPC compatible image format (VHD).
714 Specifies which VHD subformat to use. Valid options are
715 @code{dynamic} (default) and @code{fixed}.
719 Hyper-V compatible image format (VHDX).
723 Specifies which VHDX subformat to use. Valid options are
724 @code{dynamic} (default) and @code{fixed}.
725 @item block_state_zero
726 Force use of payload blocks of type 'ZERO'. Can be set to @code{on} (default)
727 or @code{off}. When set to @code{off}, new blocks will be created as
728 @code{PAYLOAD_BLOCK_NOT_PRESENT}, which means parsers are free to return
729 arbitrary data for those blocks. Do not set to @code{off} when using
730 @code{qemu-img convert} with @code{subformat=dynamic}.
732 Block size; min 1 MB, max 256 MB. 0 means auto-calculate based on image size.
738 @subsubsection Read-only formats
739 More disk image file formats are supported in a read-only mode.
742 Bochs images of @code{growing} type.
744 Linux Compressed Loop image, useful only to reuse directly compressed
745 CD-ROM images present for example in the Knoppix CD-ROMs.
749 Parallels disk image format.
754 @subsection Using host drives
756 In addition to disk image files, QEMU can directly access host
757 devices. We describe here the usage for QEMU version >= 0.8.3.
761 On Linux, you can directly use the host device filename instead of a
762 disk image filename provided you have enough privileges to access
763 it. For example, use @file{/dev/cdrom} to access to the CDROM.
767 You can specify a CDROM device even if no CDROM is loaded. QEMU has
768 specific code to detect CDROM insertion or removal. CDROM ejection by
769 the guest OS is supported. Currently only data CDs are supported.
771 You can specify a floppy device even if no floppy is loaded. Floppy
772 removal is currently not detected accurately (if you change floppy
773 without doing floppy access while the floppy is not loaded, the guest
774 OS will think that the same floppy is loaded).
775 Use of the host's floppy device is deprecated, and support for it will
776 be removed in a future release.
778 Hard disks can be used. Normally you must specify the whole disk
779 (@file{/dev/hdb} instead of @file{/dev/hdb1}) so that the guest OS can
780 see it as a partitioned disk. WARNING: unless you know what you do, it
781 is better to only make READ-ONLY accesses to the hard disk otherwise
782 you may corrupt your host data (use the @option{-snapshot} command
783 line option or modify the device permissions accordingly).
786 @subsubsection Windows
790 The preferred syntax is the drive letter (e.g. @file{d:}). The
791 alternate syntax @file{\\.\d:} is supported. @file{/dev/cdrom} is
792 supported as an alias to the first CDROM drive.
794 Currently there is no specific code to handle removable media, so it
795 is better to use the @code{change} or @code{eject} monitor commands to
796 change or eject media.
798 Hard disks can be used with the syntax: @file{\\.\PhysicalDrive@var{N}}
799 where @var{N} is the drive number (0 is the first hard disk).
800 @file{/dev/hda} is supported as an alias to
801 the first hard disk drive @file{\\.\PhysicalDrive0}.
803 WARNING: unless you know what you do, it is better to only make
804 READ-ONLY accesses to the hard disk otherwise you may corrupt your
805 host data (use the @option{-snapshot} command line so that the
806 modifications are written in a temporary file).
810 @subsubsection Mac OS X
812 @file{/dev/cdrom} is an alias to the first CDROM.
814 Currently there is no specific code to handle removable media, so it
815 is better to use the @code{change} or @code{eject} monitor commands to
816 change or eject media.
818 @node disk_images_fat_images
819 @subsection Virtual FAT disk images
821 QEMU can automatically create a virtual FAT disk image from a
822 directory tree. In order to use it, just type:
825 qemu-system-i386 linux.img -hdb fat:/my_directory
828 Then you access access to all the files in the @file{/my_directory}
829 directory without having to copy them in a disk image or to export
830 them via SAMBA or NFS. The default access is @emph{read-only}.
832 Floppies can be emulated with the @code{:floppy:} option:
835 qemu-system-i386 linux.img -fda fat:floppy:/my_directory
838 A read/write support is available for testing (beta stage) with the
842 qemu-system-i386 linux.img -fda fat:floppy:rw:/my_directory
845 What you should @emph{never} do:
847 @item use non-ASCII filenames ;
848 @item use "-snapshot" together with ":rw:" ;
849 @item expect it to work when loadvm'ing ;
850 @item write to the FAT directory on the host system while accessing it with the guest system.
853 @node disk_images_nbd
854 @subsection NBD access
856 QEMU can access directly to block device exported using the Network Block Device
860 qemu-system-i386 linux.img -hdb nbd://my_nbd_server.mydomain.org:1024/
863 If the NBD server is located on the same host, you can use an unix socket instead
867 qemu-system-i386 linux.img -hdb nbd+unix://?socket=/tmp/my_socket
870 In this case, the block device must be exported using qemu-nbd:
873 qemu-nbd --socket=/tmp/my_socket my_disk.qcow2
876 The use of qemu-nbd allows sharing of a disk between several guests:
878 qemu-nbd --socket=/tmp/my_socket --share=2 my_disk.qcow2
882 and then you can use it with two guests:
884 qemu-system-i386 linux1.img -hdb nbd+unix://?socket=/tmp/my_socket
885 qemu-system-i386 linux2.img -hdb nbd+unix://?socket=/tmp/my_socket
888 If the nbd-server uses named exports (supported since NBD 2.9.18, or with QEMU's
889 own embedded NBD server), you must specify an export name in the URI:
891 qemu-system-i386 -cdrom nbd://localhost/debian-500-ppc-netinst
892 qemu-system-i386 -cdrom nbd://localhost/openSUSE-11.1-ppc-netinst
895 The URI syntax for NBD is supported since QEMU 1.3. An alternative syntax is
896 also available. Here are some example of the older syntax:
898 qemu-system-i386 linux.img -hdb nbd:my_nbd_server.mydomain.org:1024
899 qemu-system-i386 linux2.img -hdb nbd:unix:/tmp/my_socket
900 qemu-system-i386 -cdrom nbd:localhost:10809:exportname=debian-500-ppc-netinst
903 @node disk_images_sheepdog
904 @subsection Sheepdog disk images
906 Sheepdog is a distributed storage system for QEMU. It provides highly
907 available block level storage volumes that can be attached to
908 QEMU-based virtual machines.
910 You can create a Sheepdog disk image with the command:
912 qemu-img create sheepdog:///@var{image} @var{size}
914 where @var{image} is the Sheepdog image name and @var{size} is its
917 To import the existing @var{filename} to Sheepdog, you can use a
920 qemu-img convert @var{filename} sheepdog:///@var{image}
923 You can boot from the Sheepdog disk image with the command:
925 qemu-system-i386 sheepdog:///@var{image}
928 You can also create a snapshot of the Sheepdog image like qcow2.
930 qemu-img snapshot -c @var{tag} sheepdog:///@var{image}
932 where @var{tag} is a tag name of the newly created snapshot.
934 To boot from the Sheepdog snapshot, specify the tag name of the
937 qemu-system-i386 sheepdog:///@var{image}#@var{tag}
940 You can create a cloned image from the existing snapshot.
942 qemu-img create -b sheepdog:///@var{base}#@var{tag} sheepdog:///@var{image}
944 where @var{base} is a image name of the source snapshot and @var{tag}
947 You can use an unix socket instead of an inet socket:
950 qemu-system-i386 sheepdog+unix:///@var{image}?socket=@var{path}
953 If the Sheepdog daemon doesn't run on the local host, you need to
954 specify one of the Sheepdog servers to connect to.
956 qemu-img create sheepdog://@var{hostname}:@var{port}/@var{image} @var{size}
957 qemu-system-i386 sheepdog://@var{hostname}:@var{port}/@var{image}
960 @node disk_images_iscsi
961 @subsection iSCSI LUNs
963 iSCSI is a popular protocol used to access SCSI devices across a computer
966 There are two different ways iSCSI devices can be used by QEMU.
968 The first method is to mount the iSCSI LUN on the host, and make it appear as
969 any other ordinary SCSI device on the host and then to access this device as a
970 /dev/sd device from QEMU. How to do this differs between host OSes.
972 The second method involves using the iSCSI initiator that is built into
973 QEMU. This provides a mechanism that works the same way regardless of which
974 host OS you are running QEMU on. This section will describe this second method
975 of using iSCSI together with QEMU.
977 In QEMU, iSCSI devices are described using special iSCSI URLs
981 iscsi://[<username>[%<password>]@@]<host>[:<port>]/<target-iqn-name>/<lun>
984 Username and password are optional and only used if your target is set up
985 using CHAP authentication for access control.
986 Alternatively the username and password can also be set via environment
987 variables to have these not show up in the process list
990 export LIBISCSI_CHAP_USERNAME=<username>
991 export LIBISCSI_CHAP_PASSWORD=<password>
992 iscsi://<host>/<target-iqn-name>/<lun>
995 Various session related parameters can be set via special options, either
996 in a configuration file provided via '-readconfig' or directly on the
999 If the initiator-name is not specified qemu will use a default name
1000 of 'iqn.2008-11.org.linux-kvm[:<name>'] where <name> is the name of the
1005 Setting a specific initiator name to use when logging in to the target
1006 -iscsi initiator-name=iqn.qemu.test:my-initiator
1010 Controlling which type of header digest to negotiate with the target
1011 -iscsi header-digest=CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1014 These can also be set via a configuration file
1017 user = "CHAP username"
1018 password = "CHAP password"
1019 initiator-name = "iqn.qemu.test:my-initiator"
1020 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1021 header-digest = "CRC32C"
1025 Setting the target name allows different options for different targets
1027 [iscsi "iqn.target.name"]
1028 user = "CHAP username"
1029 password = "CHAP password"
1030 initiator-name = "iqn.qemu.test:my-initiator"
1031 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1032 header-digest = "CRC32C"
1036 Howto use a configuration file to set iSCSI configuration options:
1038 cat >iscsi.conf <<EOF
1041 password = "my password"
1042 initiator-name = "iqn.qemu.test:my-initiator"
1043 header-digest = "CRC32C"
1046 qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1047 -readconfig iscsi.conf
1051 Howto set up a simple iSCSI target on loopback and accessing it via QEMU:
1053 This example shows how to set up an iSCSI target with one CDROM and one DISK
1054 using the Linux STGT software target. This target is available on Red Hat based
1055 systems as the package 'scsi-target-utils'.
1057 tgtd --iscsi portal=127.0.0.1:3260
1058 tgtadm --lld iscsi --op new --mode target --tid 1 -T iqn.qemu.test
1059 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 \
1060 -b /IMAGES/disk.img --device-type=disk
1061 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 \
1062 -b /IMAGES/cd.iso --device-type=cd
1063 tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL
1065 qemu-system-i386 -iscsi initiator-name=iqn.qemu.test:my-initiator \
1066 -boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1067 -cdrom iscsi://127.0.0.1/iqn.qemu.test/2
1070 @node disk_images_gluster
1071 @subsection GlusterFS disk images
1073 GlusterFS is an user space distributed file system.
1075 You can boot from the GlusterFS disk image with the command:
1077 qemu-system-x86_64 -drive file=gluster[+@var{transport}]://[@var{server}[:@var{port}]]/@var{volname}/@var{image}[?socket=...]
1080 @var{gluster} is the protocol.
1082 @var{transport} specifies the transport type used to connect to gluster
1083 management daemon (glusterd). Valid transport types are
1084 tcp, unix and rdma. If a transport type isn't specified, then tcp
1087 @var{server} specifies the server where the volume file specification for
1088 the given volume resides. This can be either hostname, ipv4 address
1089 or ipv6 address. ipv6 address needs to be within square brackets [ ].
1090 If transport type is unix, then @var{server} field should not be specified.
1091 Instead @var{socket} field needs to be populated with the path to unix domain
1094 @var{port} is the port number on which glusterd is listening. This is optional
1095 and if not specified, QEMU will send 0 which will make gluster to use the
1096 default port. If the transport type is unix, then @var{port} should not be
1099 @var{volname} is the name of the gluster volume which contains the disk image.
1101 @var{image} is the path to the actual disk image that resides on gluster volume.
1103 You can create a GlusterFS disk image with the command:
1105 qemu-img create gluster://@var{server}/@var{volname}/@var{image} @var{size}
1110 qemu-system-x86_64 -drive file=gluster://1.2.3.4/testvol/a.img
1111 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4/testvol/a.img
1112 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img
1113 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
1114 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img
1115 qemu-system-x86_64 -drive file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img
1116 qemu-system-x86_64 -drive file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
1117 qemu-system-x86_64 -drive file=gluster+rdma://1.2.3.4:24007/testvol/a.img
1120 @node disk_images_ssh
1121 @subsection Secure Shell (ssh) disk images
1123 You can access disk images located on a remote ssh server
1124 by using the ssh protocol:
1127 qemu-system-x86_64 -drive file=ssh://[@var{user}@@]@var{server}[:@var{port}]/@var{path}[?host_key_check=@var{host_key_check}]
1130 Alternative syntax using properties:
1133 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}]
1136 @var{ssh} is the protocol.
1138 @var{user} is the remote user. If not specified, then the local
1141 @var{server} specifies the remote ssh server. Any ssh server can be
1142 used, but it must implement the sftp-server protocol. Most Unix/Linux
1143 systems should work without requiring any extra configuration.
1145 @var{port} is the port number on which sshd is listening. By default
1146 the standard ssh port (22) is used.
1148 @var{path} is the path to the disk image.
1150 The optional @var{host_key_check} parameter controls how the remote
1151 host's key is checked. The default is @code{yes} which means to use
1152 the local @file{.ssh/known_hosts} file. Setting this to @code{no}
1153 turns off known-hosts checking. Or you can check that the host key
1154 matches a specific fingerprint:
1155 @code{host_key_check=md5:78:45:8e:14:57:4f:d5:45:83:0a:0e:f3:49:82:c9:c8}
1156 (@code{sha1:} can also be used as a prefix, but note that OpenSSH
1157 tools only use MD5 to print fingerprints).
1159 Currently authentication must be done using ssh-agent. Other
1160 authentication methods may be supported in future.
1162 Note: Many ssh servers do not support an @code{fsync}-style operation.
1163 The ssh driver cannot guarantee that disk flush requests are
1164 obeyed, and this causes a risk of disk corruption if the remote
1165 server or network goes down during writes. The driver will
1166 print a warning when @code{fsync} is not supported:
1168 warning: ssh server @code{ssh.example.com:22} does not support fsync
1170 With sufficiently new versions of libssh2 and OpenSSH, @code{fsync} is
1174 @section Network emulation
1176 QEMU can simulate several network cards (PCI or ISA cards on the PC
1177 target) and can connect them to an arbitrary number of Virtual Local
1178 Area Networks (VLANs). Host TAP devices can be connected to any QEMU
1179 VLAN. VLAN can be connected between separate instances of QEMU to
1180 simulate large networks. For simpler usage, a non privileged user mode
1181 network stack can replace the TAP device to have a basic network
1186 QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
1187 connection between several network devices. These devices can be for
1188 example QEMU virtual Ethernet cards or virtual Host ethernet devices
1191 @subsection Using TAP network interfaces
1193 This is the standard way to connect QEMU to a real network. QEMU adds
1194 a virtual network device on your host (called @code{tapN}), and you
1195 can then configure it as if it was a real ethernet card.
1197 @subsubsection Linux host
1199 As an example, you can download the @file{linux-test-xxx.tar.gz}
1200 archive and copy the script @file{qemu-ifup} in @file{/etc} and
1201 configure properly @code{sudo} so that the command @code{ifconfig}
1202 contained in @file{qemu-ifup} can be executed as root. You must verify
1203 that your host kernel supports the TAP network interfaces: the
1204 device @file{/dev/net/tun} must be present.
1206 See @ref{sec_invocation} to have examples of command lines using the
1207 TAP network interfaces.
1209 @subsubsection Windows host
1211 There is a virtual ethernet driver for Windows 2000/XP systems, called
1212 TAP-Win32. But it is not included in standard QEMU for Windows,
1213 so you will need to get it separately. It is part of OpenVPN package,
1214 so download OpenVPN from : @url{http://openvpn.net/}.
1216 @subsection Using the user mode network stack
1218 By using the option @option{-net user} (default configuration if no
1219 @option{-net} option is specified), QEMU uses a completely user mode
1220 network stack (you don't need root privilege to use the virtual
1221 network). The virtual network configuration is the following:
1225 QEMU VLAN <------> Firewall/DHCP server <-----> Internet
1228 ----> DNS server (10.0.2.3)
1230 ----> SMB server (10.0.2.4)
1233 The QEMU VM behaves as if it was behind a firewall which blocks all
1234 incoming connections. You can use a DHCP client to automatically
1235 configure the network in the QEMU VM. The DHCP server assign addresses
1236 to the hosts starting from 10.0.2.15.
1238 In order to check that the user mode network is working, you can ping
1239 the address 10.0.2.2 and verify that you got an address in the range
1240 10.0.2.x from the QEMU virtual DHCP server.
1242 Note that ICMP traffic in general does not work with user mode networking.
1243 @code{ping}, aka. ICMP echo, to the local router (10.0.2.2) shall work,
1244 however. If you're using QEMU on Linux >= 3.0, it can use unprivileged ICMP
1245 ping sockets to allow @code{ping} to the Internet. The host admin has to set
1246 the ping_group_range in order to grant access to those sockets. To allow ping
1247 for GID 100 (usually users group):
1250 echo 100 100 > /proc/sys/net/ipv4/ping_group_range
1253 When using the built-in TFTP server, the router is also the TFTP
1256 When using the @option{'-netdev user,hostfwd=...'} option, TCP or UDP
1257 connections can be redirected from the host to the guest. It allows for
1258 example to redirect X11, telnet or SSH connections.
1260 @subsection Connecting VLANs between QEMU instances
1262 Using the @option{-net socket} option, it is possible to make VLANs
1263 that span several QEMU instances. See @ref{sec_invocation} to have a
1266 @node pcsys_other_devs
1267 @section Other Devices
1269 @subsection Inter-VM Shared Memory device
1271 On Linux hosts, a shared memory device is available. The basic syntax
1275 qemu-system-x86_64 -device ivshmem-plain,memdev=@var{hostmem}
1278 where @var{hostmem} names a host memory backend. For a POSIX shared
1279 memory backend, use something like
1282 -object memory-backend-file,size=1M,share,mem-path=/dev/shm/ivshmem,id=@var{hostmem}
1285 If desired, interrupts can be sent between guest VMs accessing the same shared
1286 memory region. Interrupt support requires using a shared memory server and
1287 using a chardev socket to connect to it. The code for the shared memory server
1288 is qemu.git/contrib/ivshmem-server. An example syntax when using the shared
1292 # First start the ivshmem server once and for all
1293 ivshmem-server -p @var{pidfile} -S @var{path} -m @var{shm-name} -l @var{shm-size} -n @var{vectors}
1295 # Then start your qemu instances with matching arguments
1296 qemu-system-x86_64 -device ivshmem-doorbell,vectors=@var{vectors},chardev=@var{id}
1297 -chardev socket,path=@var{path},id=@var{id}
1300 When using the server, the guest will be assigned a VM ID (>=0) that allows guests
1301 using the same server to communicate via interrupts. Guests can read their
1302 VM ID from a device register (see ivshmem-spec.txt).
1304 @subsubsection Migration with ivshmem
1306 With device property @option{master=on}, the guest will copy the shared
1307 memory on migration to the destination host. With @option{master=off},
1308 the guest will not be able to migrate with the device attached. In the
1309 latter case, the device should be detached and then reattached after
1310 migration using the PCI hotplug support.
1312 At most one of the devices sharing the same memory can be master. The
1313 master must complete migration before you plug back the other devices.
1315 @subsubsection ivshmem and hugepages
1317 Instead of specifying the <shm size> using POSIX shm, you may specify
1318 a memory backend that has hugepage support:
1321 qemu-system-x86_64 -object memory-backend-file,size=1G,mem-path=/dev/hugepages/my-shmem-file,share,id=mb1
1322 -device ivshmem-plain,memdev=mb1
1325 ivshmem-server also supports hugepages mount points with the
1326 @option{-m} memory path argument.
1328 @node direct_linux_boot
1329 @section Direct Linux Boot
1331 This section explains how to launch a Linux kernel inside QEMU without
1332 having to make a full bootable image. It is very useful for fast Linux
1337 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
1340 Use @option{-kernel} to provide the Linux kernel image and
1341 @option{-append} to give the kernel command line arguments. The
1342 @option{-initrd} option can be used to provide an INITRD image.
1344 When using the direct Linux boot, a disk image for the first hard disk
1345 @file{hda} is required because its boot sector is used to launch the
1348 If you do not need graphical output, you can disable it and redirect
1349 the virtual serial port and the QEMU monitor to the console with the
1350 @option{-nographic} option. The typical command line is:
1352 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1353 -append "root=/dev/hda console=ttyS0" -nographic
1356 Use @key{Ctrl-a c} to switch between the serial console and the
1357 monitor (@pxref{pcsys_keys}).
1360 @section USB emulation
1362 QEMU emulates a PCI UHCI USB controller. You can virtually plug
1363 virtual USB devices or real host USB devices (experimental, works only
1364 on Linux hosts). QEMU will automatically create and connect virtual USB hubs
1365 as necessary to connect multiple USB devices.
1369 * host_usb_devices::
1372 @subsection Connecting USB devices
1374 USB devices can be connected with the @option{-usbdevice} commandline option
1375 or the @code{usb_add} monitor command. Available devices are:
1379 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1381 Pointer device that uses absolute coordinates (like a touchscreen).
1382 This means QEMU is able to report the mouse position without having
1383 to grab the mouse. Also overrides the PS/2 mouse emulation when activated.
1384 @item disk:@var{file}
1385 Mass storage device based on @var{file} (@pxref{disk_images})
1386 @item host:@var{bus.addr}
1387 Pass through the host device identified by @var{bus.addr}
1389 @item host:@var{vendor_id:product_id}
1390 Pass through the host device identified by @var{vendor_id:product_id}
1393 Virtual Wacom PenPartner tablet. This device is similar to the @code{tablet}
1394 above but it can be used with the tslib library because in addition to touch
1395 coordinates it reports touch pressure.
1397 Standard USB keyboard. Will override the PS/2 keyboard (if present).
1398 @item serial:[vendorid=@var{vendor_id}][,product_id=@var{product_id}]:@var{dev}
1399 Serial converter. This emulates an FTDI FT232BM chip connected to host character
1400 device @var{dev}. The available character devices are the same as for the
1401 @code{-serial} option. The @code{vendorid} and @code{productid} options can be
1402 used to override the default 0403:6001. For instance,
1404 usb_add serial:productid=FA00:tcp:192.168.0.2:4444
1406 will connect to tcp port 4444 of ip 192.168.0.2, and plug that to the virtual
1407 serial converter, faking a Matrix Orbital LCD Display (USB ID 0403:FA00).
1409 Braille device. This will use BrlAPI to display the braille output on a real
1411 @item net:@var{options}
1412 Network adapter that supports CDC ethernet and RNDIS protocols. @var{options}
1413 specifies NIC options as with @code{-net nic,}@var{options} (see description).
1414 For instance, user-mode networking can be used with
1416 qemu-system-i386 [...OPTIONS...] -net user,vlan=0 -usbdevice net:vlan=0
1418 Currently this cannot be used in machines that support PCI NICs.
1419 @item bt[:@var{hci-type}]
1420 Bluetooth dongle whose type is specified in the same format as with
1421 the @option{-bt hci} option, @pxref{bt-hcis,,allowed HCI types}. If
1422 no type is given, the HCI logic corresponds to @code{-bt hci,vlan=0}.
1423 This USB device implements the USB Transport Layer of HCI. Example
1426 @command{qemu-system-i386} [...@var{OPTIONS}...] @option{-usbdevice} bt:hci,vlan=3 @option{-bt} device:keyboard,vlan=3
1430 @node host_usb_devices
1431 @subsection Using host USB devices on a Linux host
1433 WARNING: this is an experimental feature. QEMU will slow down when
1434 using it. USB devices requiring real time streaming (i.e. USB Video
1435 Cameras) are not supported yet.
1438 @item If you use an early Linux 2.4 kernel, verify that no Linux driver
1439 is actually using the USB device. A simple way to do that is simply to
1440 disable the corresponding kernel module by renaming it from @file{mydriver.o}
1441 to @file{mydriver.o.disabled}.
1443 @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1449 @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:
1451 chown -R myuid /proc/bus/usb
1454 @item Launch QEMU and do in the monitor:
1457 Device 1.2, speed 480 Mb/s
1458 Class 00: USB device 1234:5678, USB DISK
1460 You should see the list of the devices you can use (Never try to use
1461 hubs, it won't work).
1463 @item Add the device in QEMU by using:
1465 usb_add host:1234:5678
1468 Normally the guest OS should report that a new USB device is
1469 plugged. You can use the option @option{-usbdevice} to do the same.
1471 @item Now you can try to use the host USB device in QEMU.
1475 When relaunching QEMU, you may have to unplug and plug again the USB
1476 device to make it work again (this is a bug).
1479 @section VNC security
1481 The VNC server capability provides access to the graphical console
1482 of the guest VM across the network. This has a number of security
1483 considerations depending on the deployment scenarios.
1487 * vnc_sec_password::
1488 * vnc_sec_certificate::
1489 * vnc_sec_certificate_verify::
1490 * vnc_sec_certificate_pw::
1492 * vnc_sec_certificate_sasl::
1493 * vnc_generate_cert::
1497 @subsection Without passwords
1499 The simplest VNC server setup does not include any form of authentication.
1500 For this setup it is recommended to restrict it to listen on a UNIX domain
1501 socket only. For example
1504 qemu-system-i386 [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
1507 This ensures that only users on local box with read/write access to that
1508 path can access the VNC server. To securely access the VNC server from a
1509 remote machine, a combination of netcat+ssh can be used to provide a secure
1512 @node vnc_sec_password
1513 @subsection With passwords
1515 The VNC protocol has limited support for password based authentication. Since
1516 the protocol limits passwords to 8 characters it should not be considered
1517 to provide high security. The password can be fairly easily brute-forced by
1518 a client making repeat connections. For this reason, a VNC server using password
1519 authentication should be restricted to only listen on the loopback interface
1520 or UNIX domain sockets. Password authentication is not supported when operating
1521 in FIPS 140-2 compliance mode as it requires the use of the DES cipher. Password
1522 authentication is requested with the @code{password} option, and then once QEMU
1523 is running the password is set with the monitor. Until the monitor is used to
1524 set the password all clients will be rejected.
1527 qemu-system-i386 [...OPTIONS...] -vnc :1,password -monitor stdio
1528 (qemu) change vnc password
1533 @node vnc_sec_certificate
1534 @subsection With x509 certificates
1536 The QEMU VNC server also implements the VeNCrypt extension allowing use of
1537 TLS for encryption of the session, and x509 certificates for authentication.
1538 The use of x509 certificates is strongly recommended, because TLS on its
1539 own is susceptible to man-in-the-middle attacks. Basic x509 certificate
1540 support provides a secure session, but no authentication. This allows any
1541 client to connect, and provides an encrypted session.
1544 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio
1547 In the above example @code{/etc/pki/qemu} should contain at least three files,
1548 @code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged
1549 users will want to use a private directory, for example @code{$HOME/.pki/qemu}.
1550 NB the @code{server-key.pem} file should be protected with file mode 0600 to
1551 only be readable by the user owning it.
1553 @node vnc_sec_certificate_verify
1554 @subsection With x509 certificates and client verification
1556 Certificates can also provide a means to authenticate the client connecting.
1557 The server will request that the client provide a certificate, which it will
1558 then validate against the CA certificate. This is a good choice if deploying
1559 in an environment with a private internal certificate authority.
1562 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
1566 @node vnc_sec_certificate_pw
1567 @subsection With x509 certificates, client verification and passwords
1569 Finally, the previous method can be combined with VNC password authentication
1570 to provide two layers of authentication for clients.
1573 qemu-system-i386 [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
1574 (qemu) change vnc password
1581 @subsection With SASL authentication
1583 The SASL authentication method is a VNC extension, that provides an
1584 easily extendable, pluggable authentication method. This allows for
1585 integration with a wide range of authentication mechanisms, such as
1586 PAM, GSSAPI/Kerberos, LDAP, SQL databases, one-time keys and more.
1587 The strength of the authentication depends on the exact mechanism
1588 configured. If the chosen mechanism also provides a SSF layer, then
1589 it will encrypt the datastream as well.
1591 Refer to the later docs on how to choose the exact SASL mechanism
1592 used for authentication, but assuming use of one supporting SSF,
1593 then QEMU can be launched with:
1596 qemu-system-i386 [...OPTIONS...] -vnc :1,sasl -monitor stdio
1599 @node vnc_sec_certificate_sasl
1600 @subsection With x509 certificates and SASL authentication
1602 If the desired SASL authentication mechanism does not supported
1603 SSF layers, then it is strongly advised to run it in combination
1604 with TLS and x509 certificates. This provides securely encrypted
1605 data stream, avoiding risk of compromising of the security
1606 credentials. This can be enabled, by combining the 'sasl' option
1607 with the aforementioned TLS + x509 options:
1610 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509,sasl -monitor stdio
1614 @node vnc_generate_cert
1615 @subsection Generating certificates for VNC
1617 The GNU TLS packages provides a command called @code{certtool} which can
1618 be used to generate certificates and keys in PEM format. At a minimum it
1619 is necessary to setup a certificate authority, and issue certificates to
1620 each server. If using certificates for authentication, then each client
1621 will also need to be issued a certificate. The recommendation is for the
1622 server to keep its certificates in either @code{/etc/pki/qemu} or for
1623 unprivileged users in @code{$HOME/.pki/qemu}.
1627 * vnc_generate_server::
1628 * vnc_generate_client::
1630 @node vnc_generate_ca
1631 @subsubsection Setup the Certificate Authority
1633 This step only needs to be performed once per organization / organizational
1634 unit. First the CA needs a private key. This key must be kept VERY secret
1635 and secure. If this key is compromised the entire trust chain of the certificates
1636 issued with it is lost.
1639 # certtool --generate-privkey > ca-key.pem
1642 A CA needs to have a public certificate. For simplicity it can be a self-signed
1643 certificate, or one issue by a commercial certificate issuing authority. To
1644 generate a self-signed certificate requires one core piece of information, the
1645 name of the organization.
1648 # cat > ca.info <<EOF
1649 cn = Name of your organization
1653 # certtool --generate-self-signed \
1654 --load-privkey ca-key.pem
1655 --template ca.info \
1656 --outfile ca-cert.pem
1659 The @code{ca-cert.pem} file should be copied to all servers and clients wishing to utilize
1660 TLS support in the VNC server. The @code{ca-key.pem} must not be disclosed/copied at all.
1662 @node vnc_generate_server
1663 @subsubsection Issuing server certificates
1665 Each server (or host) needs to be issued with a key and certificate. When connecting
1666 the certificate is sent to the client which validates it against the CA certificate.
1667 The core piece of information for a server certificate is the hostname. This should
1668 be the fully qualified hostname that the client will connect with, since the client
1669 will typically also verify the hostname in the certificate. On the host holding the
1670 secure CA private key:
1673 # cat > server.info <<EOF
1674 organization = Name of your organization
1675 cn = server.foo.example.com
1680 # certtool --generate-privkey > server-key.pem
1681 # certtool --generate-certificate \
1682 --load-ca-certificate ca-cert.pem \
1683 --load-ca-privkey ca-key.pem \
1684 --load-privkey server-key.pem \
1685 --template server.info \
1686 --outfile server-cert.pem
1689 The @code{server-key.pem} and @code{server-cert.pem} files should now be securely copied
1690 to the server for which they were generated. The @code{server-key.pem} is security
1691 sensitive and should be kept protected with file mode 0600 to prevent disclosure.
1693 @node vnc_generate_client
1694 @subsubsection Issuing client certificates
1696 If the QEMU VNC server is to use the @code{x509verify} option to validate client
1697 certificates as its authentication mechanism, each client also needs to be issued
1698 a certificate. The client certificate contains enough metadata to uniquely identify
1699 the client, typically organization, state, city, building, etc. On the host holding
1700 the secure CA private key:
1703 # cat > client.info <<EOF
1707 organization = Name of your organization
1708 cn = client.foo.example.com
1713 # certtool --generate-privkey > client-key.pem
1714 # certtool --generate-certificate \
1715 --load-ca-certificate ca-cert.pem \
1716 --load-ca-privkey ca-key.pem \
1717 --load-privkey client-key.pem \
1718 --template client.info \
1719 --outfile client-cert.pem
1722 The @code{client-key.pem} and @code{client-cert.pem} files should now be securely
1723 copied to the client for which they were generated.
1726 @node vnc_setup_sasl
1728 @subsection Configuring SASL mechanisms
1730 The following documentation assumes use of the Cyrus SASL implementation on a
1731 Linux host, but the principals should apply to any other SASL impl. When SASL
1732 is enabled, the mechanism configuration will be loaded from system default
1733 SASL service config /etc/sasl2/qemu.conf. If running QEMU as an
1734 unprivileged user, an environment variable SASL_CONF_PATH can be used
1735 to make it search alternate locations for the service config.
1737 The default configuration might contain
1740 mech_list: digest-md5
1741 sasldb_path: /etc/qemu/passwd.db
1744 This says to use the 'Digest MD5' mechanism, which is similar to the HTTP
1745 Digest-MD5 mechanism. The list of valid usernames & passwords is maintained
1746 in the /etc/qemu/passwd.db file, and can be updated using the saslpasswd2
1747 command. While this mechanism is easy to configure and use, it is not
1748 considered secure by modern standards, so only suitable for developers /
1751 A more serious deployment might use Kerberos, which is done with the 'gssapi'
1756 keytab: /etc/qemu/krb5.tab
1759 For this to work the administrator of your KDC must generate a Kerberos
1760 principal for the server, with a name of 'qemu/somehost.example.com@@EXAMPLE.COM'
1761 replacing 'somehost.example.com' with the fully qualified host name of the
1762 machine running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.
1764 Other configurations will be left as an exercise for the reader. It should
1765 be noted that only Digest-MD5 and GSSAPI provides a SSF layer for data
1766 encryption. For all other mechanisms, VNC should always be configured to
1767 use TLS and x509 certificates to protect security credentials from snooping.
1772 QEMU has a primitive support to work with gdb, so that you can do
1773 'Ctrl-C' while the virtual machine is running and inspect its state.
1775 In order to use gdb, launch QEMU with the '-s' option. It will wait for a
1778 qemu-system-i386 -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1779 -append "root=/dev/hda"
1780 Connected to host network interface: tun0
1781 Waiting gdb connection on port 1234
1784 Then launch gdb on the 'vmlinux' executable:
1789 In gdb, connect to QEMU:
1791 (gdb) target remote localhost:1234
1794 Then you can use gdb normally. For example, type 'c' to launch the kernel:
1799 Here are some useful tips in order to use gdb on system code:
1803 Use @code{info reg} to display all the CPU registers.
1805 Use @code{x/10i $eip} to display the code at the PC position.
1807 Use @code{set architecture i8086} to dump 16 bit code. Then use
1808 @code{x/10i $cs*16+$eip} to dump the code at the PC position.
1811 Advanced debugging options:
1813 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:
1815 @item maintenance packet qqemu.sstepbits
1817 This will display the MASK bits used to control the single stepping IE:
1819 (gdb) maintenance packet qqemu.sstepbits
1820 sending: "qqemu.sstepbits"
1821 received: "ENABLE=1,NOIRQ=2,NOTIMER=4"
1823 @item maintenance packet qqemu.sstep
1825 This will display the current value of the mask used when single stepping IE:
1827 (gdb) maintenance packet qqemu.sstep
1828 sending: "qqemu.sstep"
1831 @item maintenance packet Qqemu.sstep=HEX_VALUE
1833 This will change the single step mask, so if wanted to enable IRQs on the single step, but not timers, you would use:
1835 (gdb) maintenance packet Qqemu.sstep=0x5
1836 sending: "qemu.sstep=0x5"
1841 @node pcsys_os_specific
1842 @section Target OS specific information
1846 To have access to SVGA graphic modes under X11, use the @code{vesa} or
1847 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1848 color depth in the guest and the host OS.
1850 When using a 2.6 guest Linux kernel, you should add the option
1851 @code{clock=pit} on the kernel command line because the 2.6 Linux
1852 kernels make very strict real time clock checks by default that QEMU
1853 cannot simulate exactly.
1855 When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1856 not activated because QEMU is slower with this patch. The QEMU
1857 Accelerator Module is also much slower in this case. Earlier Fedora
1858 Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this
1859 patch by default. Newer kernels don't have it.
1863 If you have a slow host, using Windows 95 is better as it gives the
1864 best speed. Windows 2000 is also a good choice.
1866 @subsubsection SVGA graphic modes support
1868 QEMU emulates a Cirrus Logic GD5446 Video
1869 card. All Windows versions starting from Windows 95 should recognize
1870 and use this graphic card. For optimal performances, use 16 bit color
1871 depth in the guest and the host OS.
1873 If you are using Windows XP as guest OS and if you want to use high
1874 resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
1875 1280x1024x16), then you should use the VESA VBE virtual graphic card
1876 (option @option{-std-vga}).
1878 @subsubsection CPU usage reduction
1880 Windows 9x does not correctly use the CPU HLT
1881 instruction. The result is that it takes host CPU cycles even when
1882 idle. You can install the utility from
1883 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
1884 problem. Note that no such tool is needed for NT, 2000 or XP.
1886 @subsubsection Windows 2000 disk full problem
1888 Windows 2000 has a bug which gives a disk full problem during its
1889 installation. When installing it, use the @option{-win2k-hack} QEMU
1890 option to enable a specific workaround. After Windows 2000 is
1891 installed, you no longer need this option (this option slows down the
1894 @subsubsection Windows 2000 shutdown
1896 Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1897 can. It comes from the fact that Windows 2000 does not automatically
1898 use the APM driver provided by the BIOS.
1900 In order to correct that, do the following (thanks to Struan
1901 Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1902 Add/Troubleshoot a device => Add a new device & Next => No, select the
1903 hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1904 (again) a few times. Now the driver is installed and Windows 2000 now
1905 correctly instructs QEMU to shutdown at the appropriate moment.
1907 @subsubsection Share a directory between Unix and Windows
1909 See @ref{sec_invocation} about the help of the option
1910 @option{'-netdev user,smb=...'}.
1912 @subsubsection Windows XP security problem
1914 Some releases of Windows XP install correctly but give a security
1917 A problem is preventing Windows from accurately checking the
1918 license for this computer. Error code: 0x800703e6.
1921 The workaround is to install a service pack for XP after a boot in safe
1922 mode. Then reboot, and the problem should go away. Since there is no
1923 network while in safe mode, its recommended to download the full
1924 installation of SP1 or SP2 and transfer that via an ISO or using the
1925 vvfat block device ("-hdb fat:directory_which_holds_the_SP").
1927 @subsection MS-DOS and FreeDOS
1929 @subsubsection CPU usage reduction
1931 DOS does not correctly use the CPU HLT instruction. The result is that
1932 it takes host CPU cycles even when idle. You can install the utility
1933 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1936 @node QEMU System emulator for non PC targets
1937 @chapter QEMU System emulator for non PC targets
1939 QEMU is a generic emulator and it emulates many non PC
1940 machines. Most of the options are similar to the PC emulator. The
1941 differences are mentioned in the following sections.
1944 * PowerPC System emulator::
1945 * Sparc32 System emulator::
1946 * Sparc64 System emulator::
1947 * MIPS System emulator::
1948 * ARM System emulator::
1949 * ColdFire System emulator::
1950 * Cris System emulator::
1951 * Microblaze System emulator::
1952 * SH4 System emulator::
1953 * Xtensa System emulator::
1956 @node PowerPC System emulator
1957 @section PowerPC System emulator
1958 @cindex system emulation (PowerPC)
1960 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1961 or PowerMac PowerPC system.
1963 QEMU emulates the following PowerMac peripherals:
1967 UniNorth or Grackle PCI Bridge
1969 PCI VGA compatible card with VESA Bochs Extensions
1971 2 PMAC IDE interfaces with hard disk and CD-ROM support
1977 VIA-CUDA with ADB keyboard and mouse.
1980 QEMU emulates the following PREP peripherals:
1986 PCI VGA compatible card with VESA Bochs Extensions
1988 2 IDE interfaces with hard disk and CD-ROM support
1992 NE2000 network adapters
1996 PREP Non Volatile RAM
1998 PC compatible keyboard and mouse.
2001 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS.
2003 Since version 0.9.1, QEMU uses OpenBIOS @url{http://www.openbios.org/}
2004 for the g3beige and mac99 PowerMac machines. OpenBIOS is a free (GPL
2005 v2) portable firmware implementation. The goal is to implement a 100%
2006 IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.
2008 @c man begin OPTIONS
2010 The following options are specific to the PowerPC emulation:
2014 @item -g @var{W}x@var{H}[x@var{DEPTH}]
2016 Set the initial VGA graphic mode. The default is 800x600x32.
2018 @item -prom-env @var{string}
2020 Set OpenBIOS variables in NVRAM, for example:
2023 qemu-system-ppc -prom-env 'auto-boot?=false' \
2024 -prom-env 'boot-device=hd:2,\yaboot' \
2025 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
2028 These variables are not used by Open Hack'Ware.
2034 @node Sparc32 System emulator
2035 @section Sparc32 System emulator
2036 @cindex system emulation (Sparc32)
2038 Use the executable @file{qemu-system-sparc} to simulate the following
2039 Sun4m architecture machines:
2054 SPARCstation Voyager
2061 The emulation is somewhat complete. SMP up to 16 CPUs is supported,
2062 but Linux limits the number of usable CPUs to 4.
2064 QEMU emulates the following sun4m peripherals:
2070 TCX or cgthree Frame buffer
2072 Lance (Am7990) Ethernet
2074 Non Volatile RAM M48T02/M48T08
2076 Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
2077 and power/reset logic
2079 ESP SCSI controller with hard disk and CD-ROM support
2081 Floppy drive (not on SS-600MP)
2083 CS4231 sound device (only on SS-5, not working yet)
2086 The number of peripherals is fixed in the architecture. Maximum
2087 memory size depends on the machine type, for SS-5 it is 256MB and for
2090 Since version 0.8.2, QEMU uses OpenBIOS
2091 @url{http://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
2092 firmware implementation. The goal is to implement a 100% IEEE
2093 1275-1994 (referred to as Open Firmware) compliant firmware.
2095 A sample Linux 2.6 series kernel and ram disk image are available on
2096 the QEMU web site. There are still issues with NetBSD and OpenBSD, but
2097 most kernel versions work. Please note that currently older Solaris kernels
2098 don't work probably due to interface issues between OpenBIOS and
2101 @c man begin OPTIONS
2103 The following options are specific to the Sparc32 emulation:
2107 @item -g @var{W}x@var{H}x[x@var{DEPTH}]
2109 Set the initial graphics mode. For TCX, the default is 1024x768x8 with the
2110 option of 1024x768x24. For cgthree, the default is 1024x768x8 with the option
2111 of 1152x900x8 for people who wish to use OBP.
2113 @item -prom-env @var{string}
2115 Set OpenBIOS variables in NVRAM, for example:
2118 qemu-system-sparc -prom-env 'auto-boot?=false' \
2119 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
2122 @item -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic] [|SPARCbook]
2124 Set the emulated machine type. Default is SS-5.
2130 @node Sparc64 System emulator
2131 @section Sparc64 System emulator
2132 @cindex system emulation (Sparc64)
2134 Use the executable @file{qemu-system-sparc64} to simulate a Sun4u
2135 (UltraSPARC PC-like machine), Sun4v (T1 PC-like machine), or generic
2136 Niagara (T1) machine. The Sun4u emulator is mostly complete, being
2137 able to run Linux, NetBSD and OpenBSD in headless (-nographic) mode. The
2138 Sun4v and Niagara emulators are still a work in progress.
2140 QEMU emulates the following peripherals:
2144 UltraSparc IIi APB PCI Bridge
2146 PCI VGA compatible card with VESA Bochs Extensions
2148 PS/2 mouse and keyboard
2150 Non Volatile RAM M48T59
2152 PC-compatible serial ports
2154 2 PCI IDE interfaces with hard disk and CD-ROM support
2159 @c man begin OPTIONS
2161 The following options are specific to the Sparc64 emulation:
2165 @item -prom-env @var{string}
2167 Set OpenBIOS variables in NVRAM, for example:
2170 qemu-system-sparc64 -prom-env 'auto-boot?=false'
2173 @item -M [sun4u|sun4v|Niagara]
2175 Set the emulated machine type. The default is sun4u.
2181 @node MIPS System emulator
2182 @section MIPS System emulator
2183 @cindex system emulation (MIPS)
2185 Four executables cover simulation of 32 and 64-bit MIPS systems in
2186 both endian options, @file{qemu-system-mips}, @file{qemu-system-mipsel}
2187 @file{qemu-system-mips64} and @file{qemu-system-mips64el}.
2188 Five different machine types are emulated:
2192 A generic ISA PC-like machine "mips"
2194 The MIPS Malta prototype board "malta"
2196 An ACER Pica "pica61". This machine needs the 64-bit emulator.
2198 MIPS emulator pseudo board "mipssim"
2200 A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator.
2203 The generic emulation is supported by Debian 'Etch' and is able to
2204 install Debian into a virtual disk image. The following devices are
2209 A range of MIPS CPUs, default is the 24Kf
2211 PC style serial port
2218 The Malta emulation supports the following devices:
2222 Core board with MIPS 24Kf CPU and Galileo system controller
2224 PIIX4 PCI/USB/SMbus controller
2226 The Multi-I/O chip's serial device
2228 PCI network cards (PCnet32 and others)
2230 Malta FPGA serial device
2232 Cirrus (default) or any other PCI VGA graphics card
2235 The ACER Pica emulation supports:
2241 PC-style IRQ and DMA controllers
2248 The mipssim pseudo board emulation provides an environment similar
2249 to what the proprietary MIPS emulator uses for running Linux.
2254 A range of MIPS CPUs, default is the 24Kf
2256 PC style serial port
2258 MIPSnet network emulation
2261 The MIPS Magnum R4000 emulation supports:
2267 PC-style IRQ controller
2277 @node ARM System emulator
2278 @section ARM System emulator
2279 @cindex system emulation (ARM)
2281 Use the executable @file{qemu-system-arm} to simulate a ARM
2282 machine. The ARM Integrator/CP board is emulated with the following
2287 ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU
2291 SMC 91c111 Ethernet adapter
2293 PL110 LCD controller
2295 PL050 KMI with PS/2 keyboard and mouse.
2297 PL181 MultiMedia Card Interface with SD card.
2300 The ARM Versatile baseboard is emulated with the following devices:
2304 ARM926E, ARM1136 or Cortex-A8 CPU
2306 PL190 Vectored Interrupt Controller
2310 SMC 91c111 Ethernet adapter
2312 PL110 LCD controller
2314 PL050 KMI with PS/2 keyboard and mouse.
2316 PCI host bridge. Note the emulated PCI bridge only provides access to
2317 PCI memory space. It does not provide access to PCI IO space.
2318 This means some devices (eg. ne2k_pci NIC) are not usable, and others
2319 (eg. rtl8139 NIC) are only usable when the guest drivers use the memory
2320 mapped control registers.
2322 PCI OHCI USB controller.
2324 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
2326 PL181 MultiMedia Card Interface with SD card.
2329 Several variants of the ARM RealView baseboard are emulated,
2330 including the EB, PB-A8 and PBX-A9. Due to interactions with the
2331 bootloader, only certain Linux kernel configurations work out
2332 of the box on these boards.
2334 Kernels for the PB-A8 board should have CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2335 enabled in the kernel, and expect 512M RAM. Kernels for The PBX-A9 board
2336 should have CONFIG_SPARSEMEM enabled, CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2337 disabled and expect 1024M RAM.
2339 The following devices are emulated:
2343 ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU
2345 ARM AMBA Generic/Distributed Interrupt Controller
2349 SMC 91c111 or SMSC LAN9118 Ethernet adapter
2351 PL110 LCD controller
2353 PL050 KMI with PS/2 keyboard and mouse
2357 PCI OHCI USB controller
2359 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
2361 PL181 MultiMedia Card Interface with SD card.
2364 The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
2365 and "Terrier") emulation includes the following peripherals:
2369 Intel PXA270 System-on-chip (ARM V5TE core)
2373 IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
2375 On-chip OHCI USB controller
2377 On-chip LCD controller
2379 On-chip Real Time Clock
2381 TI ADS7846 touchscreen controller on SSP bus
2383 Maxim MAX1111 analog-digital converter on I@math{^2}C bus
2385 GPIO-connected keyboard controller and LEDs
2387 Secure Digital card connected to PXA MMC/SD host
2391 WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
2394 The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the
2399 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2401 ROM and RAM memories (ROM firmware image can be loaded with -option-rom)
2403 On-chip LCD controller
2405 On-chip Real Time Clock
2407 TI TSC2102i touchscreen controller / analog-digital converter / Audio
2408 CODEC, connected through MicroWire and I@math{^2}S busses
2410 GPIO-connected matrix keypad
2412 Secure Digital card connected to OMAP MMC/SD host
2417 Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48)
2418 emulation supports the following elements:
2422 Texas Instruments OMAP2420 System-on-chip (ARM 1136 core)
2424 RAM and non-volatile OneNAND Flash memories
2426 Display connected to EPSON remote framebuffer chip and OMAP on-chip
2427 display controller and a LS041y3 MIPI DBI-C controller
2429 TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers
2430 driven through SPI bus
2432 National Semiconductor LM8323-controlled qwerty keyboard driven
2433 through I@math{^2}C bus
2435 Secure Digital card connected to OMAP MMC/SD host
2437 Three OMAP on-chip UARTs and on-chip STI debugging console
2439 A Bluetooth(R) transceiver and HCI connected to an UART
2441 Mentor Graphics "Inventra" dual-role USB controller embedded in a TI
2442 TUSB6010 chip - only USB host mode is supported
2444 TI TMP105 temperature sensor driven through I@math{^2}C bus
2446 TI TWL92230C power management companion with an RTC on I@math{^2}C bus
2448 Nokia RETU and TAHVO multi-purpose chips with an RTC, connected
2452 The Luminary Micro Stellaris LM3S811EVB emulation includes the following
2459 64k Flash and 8k SRAM.
2461 Timers, UARTs, ADC and I@math{^2}C interface.
2463 OSRAM Pictiva 96x16 OLED with SSD0303 controller on I@math{^2}C bus.
2466 The Luminary Micro Stellaris LM3S6965EVB emulation includes the following
2473 256k Flash and 64k SRAM.
2475 Timers, UARTs, ADC, I@math{^2}C and SSI interfaces.
2477 OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI.
2480 The Freecom MusicPal internet radio emulation includes the following
2485 Marvell MV88W8618 ARM core.
2487 32 MB RAM, 256 KB SRAM, 8 MB flash.
2491 MV88W8xx8 Ethernet controller
2493 MV88W8618 audio controller, WM8750 CODEC and mixer
2495 128×64 display with brightness control
2497 2 buttons, 2 navigation wheels with button function
2500 The Siemens SX1 models v1 and v2 (default) basic emulation.
2501 The emulation includes the following elements:
2505 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2507 ROM and RAM memories (ROM firmware image can be loaded with -pflash)
2509 1 Flash of 16MB and 1 Flash of 8MB
2513 On-chip LCD controller
2515 On-chip Real Time Clock
2517 Secure Digital card connected to OMAP MMC/SD host
2522 A Linux 2.6 test image is available on the QEMU web site. More
2523 information is available in the QEMU mailing-list archive.
2525 @c man begin OPTIONS
2527 The following options are specific to the ARM emulation:
2532 Enable semihosting syscall emulation.
2534 On ARM this implements the "Angel" interface.
2536 Note that this allows guest direct access to the host filesystem,
2537 so should only be used with trusted guest OS.
2541 @node ColdFire System emulator
2542 @section ColdFire System emulator
2543 @cindex system emulation (ColdFire)
2544 @cindex system emulation (M68K)
2546 Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2547 The emulator is able to boot a uClinux kernel.
2549 The M5208EVB emulation includes the following devices:
2553 MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2555 Three Two on-chip UARTs.
2557 Fast Ethernet Controller (FEC)
2560 The AN5206 emulation includes the following devices:
2564 MCF5206 ColdFire V2 Microprocessor.
2569 @c man begin OPTIONS
2571 The following options are specific to the ColdFire emulation:
2576 Enable semihosting syscall emulation.
2578 On M68K this implements the "ColdFire GDB" interface used by libgloss.
2580 Note that this allows guest direct access to the host filesystem,
2581 so should only be used with trusted guest OS.
2585 @node Cris System emulator
2586 @section Cris System emulator
2587 @cindex system emulation (Cris)
2591 @node Microblaze System emulator
2592 @section Microblaze System emulator
2593 @cindex system emulation (Microblaze)
2597 @node SH4 System emulator
2598 @section SH4 System emulator
2599 @cindex system emulation (SH4)
2603 @node Xtensa System emulator
2604 @section Xtensa System emulator
2605 @cindex system emulation (Xtensa)
2607 Two executables cover simulation of both Xtensa endian options,
2608 @file{qemu-system-xtensa} and @file{qemu-system-xtensaeb}.
2609 Two different machine types are emulated:
2613 Xtensa emulator pseudo board "sim"
2615 Avnet LX60/LX110/LX200 board
2618 The sim pseudo board emulation provides an environment similar
2619 to one provided by the proprietary Tensilica ISS.
2624 A range of Xtensa CPUs, default is the DC232B
2626 Console and filesystem access via semihosting calls
2629 The Avnet LX60/LX110/LX200 emulation supports:
2633 A range of Xtensa CPUs, default is the DC232B
2637 OpenCores 10/100 Mbps Ethernet MAC
2640 @c man begin OPTIONS
2642 The following options are specific to the Xtensa emulation:
2647 Enable semihosting syscall emulation.
2649 Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select.
2650 Tensilica baremetal libc for ISS and linux platform "sim" use this interface.
2652 Note that this allows guest direct access to the host filesystem,
2653 so should only be used with trusted guest OS.
2656 @node QEMU User space emulator
2657 @chapter QEMU User space emulator
2660 * Supported Operating Systems ::
2661 * Linux User space emulator::
2662 * BSD User space emulator ::
2665 @node Supported Operating Systems
2666 @section Supported Operating Systems
2668 The following OS are supported in user space emulation:
2672 Linux (referred as qemu-linux-user)
2674 BSD (referred as qemu-bsd-user)
2677 @node Linux User space emulator
2678 @section Linux User space emulator
2683 * Command line options::
2688 @subsection Quick Start
2690 In order to launch a Linux process, QEMU needs the process executable
2691 itself and all the target (x86) dynamic libraries used by it.
2695 @item On x86, you can just try to launch any process by using the native
2699 qemu-i386 -L / /bin/ls
2702 @code{-L /} tells that the x86 dynamic linker must be searched with a
2705 @item Since QEMU is also a linux process, you can launch QEMU with
2706 QEMU (NOTE: you can only do that if you compiled QEMU from the sources):
2709 qemu-i386 -L / qemu-i386 -L / /bin/ls
2712 @item On non x86 CPUs, you need first to download at least an x86 glibc
2713 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2714 @code{LD_LIBRARY_PATH} is not set:
2717 unset LD_LIBRARY_PATH
2720 Then you can launch the precompiled @file{ls} x86 executable:
2723 qemu-i386 tests/i386/ls
2725 You can look at @file{scripts/qemu-binfmt-conf.sh} so that
2726 QEMU is automatically launched by the Linux kernel when you try to
2727 launch x86 executables. It requires the @code{binfmt_misc} module in the
2730 @item The x86 version of QEMU is also included. You can try weird things such as:
2732 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2733 /usr/local/qemu-i386/bin/ls-i386
2739 @subsection Wine launch
2743 @item Ensure that you have a working QEMU with the x86 glibc
2744 distribution (see previous section). In order to verify it, you must be
2748 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2751 @item Download the binary x86 Wine install
2752 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2754 @item Configure Wine on your account. Look at the provided script
2755 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2756 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2758 @item Then you can try the example @file{putty.exe}:
2761 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2762 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2767 @node Command line options
2768 @subsection Command line options
2771 @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}...]
2778 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2780 Set the x86 stack size in bytes (default=524288)
2782 Select CPU model (-cpu help for list and additional feature selection)
2783 @item -E @var{var}=@var{value}
2784 Set environment @var{var} to @var{value}.
2786 Remove @var{var} from the environment.
2788 Offset guest address by the specified number of bytes. This is useful when
2789 the address region required by guest applications is reserved on the host.
2790 This option is currently only supported on some hosts.
2792 Pre-allocate a guest virtual address space of the given size (in bytes).
2793 "G", "M", and "k" suffixes may be used when specifying the size.
2800 Activate logging of the specified items (use '-d help' for a list of log items)
2802 Act as if the host page size was 'pagesize' bytes
2804 Wait gdb connection to port
2806 Run the emulation in single step mode.
2809 Environment variables:
2813 Print system calls and arguments similar to the 'strace' program
2814 (NOTE: the actual 'strace' program will not work because the user
2815 space emulator hasn't implemented ptrace). At the moment this is
2816 incomplete. All system calls that don't have a specific argument
2817 format are printed with information for six arguments. Many
2818 flag-style arguments don't have decoders and will show up as numbers.
2821 @node Other binaries
2822 @subsection Other binaries
2824 @cindex user mode (Alpha)
2825 @command{qemu-alpha} TODO.
2827 @cindex user mode (ARM)
2828 @command{qemu-armeb} TODO.
2830 @cindex user mode (ARM)
2831 @command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2832 binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2833 configurations), and arm-uclinux bFLT format binaries.
2835 @cindex user mode (ColdFire)
2836 @cindex user mode (M68K)
2837 @command{qemu-m68k} is capable of running semihosted binaries using the BDM
2838 (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2839 coldfire uClinux bFLT format binaries.
2841 The binary format is detected automatically.
2843 @cindex user mode (Cris)
2844 @command{qemu-cris} TODO.
2846 @cindex user mode (i386)
2847 @command{qemu-i386} TODO.
2848 @command{qemu-x86_64} TODO.
2850 @cindex user mode (Microblaze)
2851 @command{qemu-microblaze} TODO.
2853 @cindex user mode (MIPS)
2854 @command{qemu-mips} TODO.
2855 @command{qemu-mipsel} TODO.
2857 @cindex user mode (PowerPC)
2858 @command{qemu-ppc64abi32} TODO.
2859 @command{qemu-ppc64} TODO.
2860 @command{qemu-ppc} TODO.
2862 @cindex user mode (SH4)
2863 @command{qemu-sh4eb} TODO.
2864 @command{qemu-sh4} TODO.
2866 @cindex user mode (SPARC)
2867 @command{qemu-sparc} can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).
2869 @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2870 (Sparc64 CPU, 32 bit ABI).
2872 @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2873 SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2875 @node BSD User space emulator
2876 @section BSD User space emulator
2881 * BSD Command line options::
2885 @subsection BSD Status
2889 target Sparc64 on Sparc64: Some trivial programs work.
2892 @node BSD Quick Start
2893 @subsection Quick Start
2895 In order to launch a BSD process, QEMU needs the process executable
2896 itself and all the target dynamic libraries used by it.
2900 @item On Sparc64, you can just try to launch any process by using the native
2904 qemu-sparc64 /bin/ls
2909 @node BSD Command line options
2910 @subsection Command line options
2913 @command{qemu-sparc64} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-bsd} @var{type}] @var{program} [@var{arguments}...]
2920 Set the library root path (default=/)
2922 Set the stack size in bytes (default=524288)
2923 @item -ignore-environment
2924 Start with an empty environment. Without this option,
2925 the initial environment is a copy of the caller's environment.
2926 @item -E @var{var}=@var{value}
2927 Set environment @var{var} to @var{value}.
2929 Remove @var{var} from the environment.
2931 Set the type of the emulated BSD Operating system. Valid values are
2932 FreeBSD, NetBSD and OpenBSD (default).
2939 Activate logging of the specified items (use '-d help' for a list of log items)
2941 Act as if the host page size was 'pagesize' bytes
2943 Run the emulation in single step mode.
2947 @chapter Compilation from the sources
2952 * Cross compilation for Windows with Linux::
2960 @subsection Compilation
2962 First you must decompress the sources:
2965 tar zxvf qemu-x.y.z.tar.gz
2969 Then you configure QEMU and build it (usually no options are needed):
2975 Then type as root user:
2979 to install QEMU in @file{/usr/local}.
2985 @item Install the current versions of MSYS and MinGW from
2986 @url{http://www.mingw.org/}. You can find detailed installation
2987 instructions in the download section and the FAQ.
2990 the MinGW development library of SDL 1.2.x
2991 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
2992 @url{http://www.libsdl.org}. Unpack it in a temporary place and
2993 edit the @file{sdl-config} script so that it gives the
2994 correct SDL directory when invoked.
2996 @item Install the MinGW version of zlib and make sure
2997 @file{zlib.h} and @file{libz.dll.a} are in
2998 MinGW's default header and linker search paths.
3000 @item Extract the current version of QEMU.
3002 @item Start the MSYS shell (file @file{msys.bat}).
3004 @item Change to the QEMU directory. Launch @file{./configure} and
3005 @file{make}. If you have problems using SDL, verify that
3006 @file{sdl-config} can be launched from the MSYS command line.
3008 @item You can install QEMU in @file{Program Files/QEMU} by typing
3009 @file{make install}. Don't forget to copy @file{SDL.dll} in
3010 @file{Program Files/QEMU}.
3014 @node Cross compilation for Windows with Linux
3015 @section Cross compilation for Windows with Linux
3019 Install the MinGW cross compilation tools available at
3020 @url{http://www.mingw.org/}.
3023 the MinGW development library of SDL 1.2.x
3024 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
3025 @url{http://www.libsdl.org}. Unpack it in a temporary place and
3026 edit the @file{sdl-config} script so that it gives the
3027 correct SDL directory when invoked. Set up the @code{PATH} environment
3028 variable so that @file{sdl-config} can be launched by
3029 the QEMU configuration script.
3031 @item Install the MinGW version of zlib and make sure
3032 @file{zlib.h} and @file{libz.dll.a} are in
3033 MinGW's default header and linker search paths.
3036 Configure QEMU for Windows cross compilation:
3038 PATH=/usr/i686-pc-mingw32/sys-root/mingw/bin:$PATH ./configure --cross-prefix='i686-pc-mingw32-'
3040 The example assumes @file{sdl-config} is installed under @file{/usr/i686-pc-mingw32/sys-root/mingw/bin} and
3041 MinGW cross compilation tools have names like @file{i686-pc-mingw32-gcc} and @file{i686-pc-mingw32-strip}.
3042 We set the @code{PATH} environment variable to ensure the MinGW version of @file{sdl-config} is used and
3043 use --cross-prefix to specify the name of the cross compiler.
3044 You can also use --prefix to set the Win32 install path which defaults to @file{c:/Program Files/QEMU}.
3046 Under Fedora Linux, you can run:
3048 yum -y install mingw32-gcc mingw32-SDL mingw32-zlib
3050 to get a suitable cross compilation environment.
3052 @item You can install QEMU in the installation directory by typing
3053 @code{make install}. Don't forget to copy @file{SDL.dll} and @file{zlib1.dll} into the
3054 installation directory.
3058 @cindex wine, starting system emulation
3059 Wine can be used to launch the resulting qemu-system-i386.exe
3060 and all other qemu-system-@var{target}.exe compiled for Win32.
3062 wine qemu-system-i386
3068 System Requirements:
3070 @item Mac OS 10.5 or higher
3071 @item The clang compiler shipped with Xcode 4.2 or higher,
3072 or GCC 4.3 or higher
3075 Additional Requirements (install in order):
3077 @item libffi: @uref{https://sourceware.org/libffi/}
3078 @item gettext: @uref{http://www.gnu.org/software/gettext/}
3079 @item glib: @uref{http://ftp.gnome.org/pub/GNOME/sources/glib/}
3080 @item pkg-config: @uref{http://www.freedesktop.org/wiki/Software/pkg-config/}
3081 @item autoconf: @uref{http://www.gnu.org/software/autoconf/autoconf.html}
3082 @item automake: @uref{http://www.gnu.org/software/automake/}
3083 @item pixman: @uref{http://www.pixman.org/}
3086 * You may find it easiest to get these from a third-party packager
3087 such as Homebrew, Macports, or Fink.
3089 After downloading the QEMU source code, double-click it to expand it.
3091 Then configure and make QEMU:
3097 If you have a recent version of Mac OS X (OSX 10.7 or better
3098 with Xcode 4.2 or better) we recommend building QEMU with the
3099 default compiler provided by Apple, for your version of Mac OS X
3100 (which will be 'clang'). The configure script will
3101 automatically pick this.
3103 Note: If after the configure step you see a message like this:
3105 ERROR: Your compiler does not support the __thread specifier for
3106 Thread-Local Storage (TLS). Please upgrade to a version that does.
3108 you may have to build your own version of gcc from source. Expect that to take
3109 several hours. More information can be found here:
3110 @uref{https://gcc.gnu.org/install/} @*
3112 These are some of the third party binaries of gcc available for download:
3114 @item Homebrew: @uref{http://brew.sh/}
3115 @item @uref{https://www.litebeam.net/gcc/gcc_472.pkg}
3116 @item @uref{http://www.macports.org/ports.php?by=name&substr=gcc}
3119 You can have several versions of GCC on your system. To specify a certain version,
3120 use the --cc and --cxx options.
3122 ./configure --cxx=<path of your c++ compiler> --cc=<path of your c compiler> <other options>
3126 @section Make targets
3132 Make everything which is typically needed.
3141 Remove most files which were built during make.
3143 @item make distclean
3144 Remove everything which was built during make.
3150 Create documentation in dvi, html, info or pdf format.
3155 @item make defconfig
3156 (Re-)create some build configuration files.
3157 User made changes will be overwritten.
3168 QEMU is a trademark of Fabrice Bellard.
3170 QEMU is released under the GNU General Public License (TODO: add link).
3171 Parts of QEMU have specific licenses, see file LICENSE.
3173 TODO (refer to file LICENSE, include it, include the GPL?)
3187 @section Concept Index
3188 This is the main index. Should we combine all keywords in one index? TODO
3191 @node Function Index
3192 @section Function Index
3193 This index could be used for command line options and monitor functions.
3196 @node Keystroke Index
3197 @section Keystroke Index
3199 This is a list of all keystrokes which have a special function
3200 in system emulation.
3205 @section Program Index
3208 @node Data Type Index
3209 @section Data Type Index
3211 This index could be used for qdev device names and options.
3215 @node Variable Index
3216 @section Variable Index