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}
35 * QEMU PC System emulator::
36 * QEMU System emulator for non PC targets::
37 * QEMU User space emulator::
38 * Implementation notes::
50 * intro_features:: Features
56 QEMU is a FAST! processor emulator using dynamic translation to
57 achieve good emulation speed.
59 @cindex operating modes
60 QEMU has two operating modes:
63 @cindex system emulation
64 @item Full system emulation. In this mode, QEMU emulates a full system (for
65 example a PC), including one or several processors and various
66 peripherals. It can be used to launch different Operating Systems
67 without rebooting the PC or to debug system code.
69 @cindex user mode emulation
70 @item User mode emulation. In this mode, QEMU can launch
71 processes compiled for one CPU on another CPU. It can be used to
72 launch the Wine Windows API emulator (@url{http://www.winehq.org}) or
73 to ease cross-compilation and cross-debugging.
77 QEMU has the following features:
80 @item QEMU can run without a host kernel driver and yet gives acceptable
81 performance. It uses dynamic translation to native code for reasonable speed,
82 with support for self-modifying code and precise exceptions.
84 @item It is portable to several operating systems (GNU/Linux, *BSD, Mac OS X,
85 Windows) and architectures.
87 @item It performs accurate software emulation of the FPU.
90 QEMU user mode emulation has the following features:
92 @item Generic Linux system call converter, including most ioctls.
94 @item clone() emulation using native CPU clone() to use Linux scheduler for threads.
96 @item Accurate signal handling by remapping host signals to target signals.
99 QEMU full system emulation has the following features:
102 QEMU uses a full software MMU for maximum portability.
105 QEMU can optionally use an in-kernel accelerator, like kvm. The accelerators
106 execute most of the guest code natively, while
107 continuing to emulate the rest of the machine.
110 Various hardware devices can be emulated and in some cases, host
111 devices (e.g. serial and parallel ports, USB, drives) can be used
112 transparently by the guest Operating System. Host device passthrough
113 can be used for talking to external physical peripherals (e.g. a
114 webcam, modem or tape drive).
117 Symmetric multiprocessing (SMP) support. Currently, an in-kernel
118 accelerator is required to use more than one host CPU for emulation.
123 @node QEMU PC System emulator
124 @chapter QEMU PC System emulator
125 @cindex system emulation (PC)
128 * pcsys_introduction:: Introduction
129 * pcsys_quickstart:: Quick Start
130 * sec_invocation:: Invocation
131 * pcsys_keys:: Keys in the graphical frontends
132 * mux_keys:: Keys in the character backend multiplexer
133 * pcsys_monitor:: QEMU Monitor
134 * disk_images:: Disk Images
135 * pcsys_network:: Network emulation
136 * pcsys_other_devs:: Other Devices
137 * direct_linux_boot:: Direct Linux Boot
138 * pcsys_usb:: USB emulation
139 * vnc_security:: VNC security
140 * gdb_usage:: GDB usage
141 * pcsys_os_specific:: Target OS specific information
144 @node pcsys_introduction
145 @section Introduction
147 @c man begin DESCRIPTION
149 The QEMU PC System emulator simulates the
150 following peripherals:
154 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
156 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
157 extensions (hardware level, including all non standard modes).
159 PS/2 mouse and keyboard
161 2 PCI IDE interfaces with hard disk and CD-ROM support
165 PCI and ISA network adapters
169 IPMI BMC, either and internal or external one
171 Creative SoundBlaster 16 sound card
173 ENSONIQ AudioPCI ES1370 sound card
175 Intel 82801AA AC97 Audio compatible sound card
177 Intel HD Audio Controller and HDA codec
179 Adlib (OPL2) - Yamaha YM3812 compatible chip
181 Gravis Ultrasound GF1 sound card
183 CS4231A compatible sound card
185 PCI UHCI USB controller and a virtual USB hub.
188 SMP is supported with up to 255 CPUs.
190 QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs LGPL
193 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
195 QEMU uses GUS emulation (GUSEMU32 @url{http://www.deinmeister.de/gusemu/})
196 by Tibor "TS" Schütz.
198 Note that, by default, GUS shares IRQ(7) with parallel ports and so
199 QEMU must be told to not have parallel ports to have working GUS.
202 qemu-system-i386 dos.img -soundhw gus -parallel none
207 qemu-system-i386 dos.img -device gus,irq=5
210 Or some other unclaimed IRQ.
212 CS4231A is the chip used in Windows Sound System and GUSMAX products
216 @node pcsys_quickstart
220 Download and uncompress the linux image (@file{linux.img}) and type:
223 qemu-system-i386 linux.img
226 Linux should boot and give you a prompt.
232 @c man begin SYNOPSIS
233 @command{qemu-system-i386} [@var{options}] [@var{disk_image}]
238 @var{disk_image} is a raw hard disk image for IDE hard disk 0. Some
239 targets do not need a disk image.
241 @include qemu-options.texi
246 @section Keys in the graphical frontends
250 During the graphical emulation, you can use special key combinations to change
251 modes. The default key mappings are shown below, but if you use @code{-alt-grab}
252 then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use
253 @code{-ctrl-grab} then the modifier is the right Ctrl key (instead of Ctrl-Alt):
270 Restore the screen's un-scaled dimensions
274 Switch to virtual console 'n'. Standard console mappings are:
277 Target system display
286 Toggle mouse and keyboard grab.
292 @kindex Ctrl-PageDown
293 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
294 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
299 @section Keys in the character backend multiplexer
303 During emulation, if you are using a character backend multiplexer
304 (which is the default if you are using @option{-nographic}) then
305 several commands are available via an escape sequence. These
306 key sequences all start with an escape character, which is @key{Ctrl-a}
307 by default, but can be changed with @option{-echr}. The list below assumes
308 you're using the default.
319 Save disk data back to file (if -snapshot)
322 Toggle console timestamps
325 Send break (magic sysrq in Linux)
328 Rotate between the frontends connected to the multiplexer (usually
329 this switches between the monitor and the console)
331 @kindex Ctrl-a Ctrl-a
332 Send the escape character to the frontend
339 The HTML documentation of QEMU for more precise information and Linux
340 user mode emulator invocation.
350 @section QEMU Monitor
353 The QEMU monitor is used to give complex commands to the QEMU
354 emulator. You can use it to:
359 Remove or insert removable media images
360 (such as CD-ROM or floppies).
363 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
366 @item Inspect the VM state without an external debugger.
372 The following commands are available:
374 @include qemu-monitor.texi
376 @include qemu-monitor-info.texi
378 @subsection Integer expressions
380 The monitor understands integers expressions for every integer
381 argument. You can use register names to get the value of specifics
382 CPU registers by prefixing them with @emph{$}.
387 Since version 0.6.1, QEMU supports many disk image formats, including
388 growable disk images (their size increase as non empty sectors are
389 written), compressed and encrypted disk images. Version 0.8.3 added
390 the new qcow2 disk image format which is essential to support VM
394 * disk_images_quickstart:: Quick start for disk image creation
395 * disk_images_snapshot_mode:: Snapshot mode
396 * vm_snapshots:: VM snapshots
397 * qemu_img_invocation:: qemu-img Invocation
398 * qemu_nbd_invocation:: qemu-nbd Invocation
399 * qemu_ga_invocation:: qemu-ga Invocation
400 * disk_images_formats:: Disk image file formats
401 * host_drives:: Using host drives
402 * disk_images_fat_images:: Virtual FAT disk images
403 * disk_images_nbd:: NBD access
404 * disk_images_sheepdog:: Sheepdog disk images
405 * disk_images_iscsi:: iSCSI LUNs
406 * disk_images_gluster:: GlusterFS disk images
407 * disk_images_ssh:: Secure Shell (ssh) disk images
410 @node disk_images_quickstart
411 @subsection Quick start for disk image creation
413 You can create a disk image with the command:
415 qemu-img create myimage.img mysize
417 where @var{myimage.img} is the disk image filename and @var{mysize} is its
418 size in kilobytes. You can add an @code{M} suffix to give the size in
419 megabytes and a @code{G} suffix for gigabytes.
421 See @ref{qemu_img_invocation} for more information.
423 @node disk_images_snapshot_mode
424 @subsection Snapshot mode
426 If you use the option @option{-snapshot}, all disk images are
427 considered as read only. When sectors in written, they are written in
428 a temporary file created in @file{/tmp}. You can however force the
429 write back to the raw disk images by using the @code{commit} monitor
430 command (or @key{C-a s} in the serial console).
433 @subsection VM snapshots
435 VM snapshots are snapshots of the complete virtual machine including
436 CPU state, RAM, device state and the content of all the writable
437 disks. In order to use VM snapshots, you must have at least one non
438 removable and writable block device using the @code{qcow2} disk image
439 format. Normally this device is the first virtual hard drive.
441 Use the monitor command @code{savevm} to create a new VM snapshot or
442 replace an existing one. A human readable name can be assigned to each
443 snapshot in addition to its numerical ID.
445 Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
446 a VM snapshot. @code{info snapshots} lists the available snapshots
447 with their associated information:
450 (qemu) info snapshots
451 Snapshot devices: hda
452 Snapshot list (from hda):
453 ID TAG VM SIZE DATE VM CLOCK
454 1 start 41M 2006-08-06 12:38:02 00:00:14.954
455 2 40M 2006-08-06 12:43:29 00:00:18.633
456 3 msys 40M 2006-08-06 12:44:04 00:00:23.514
459 A VM snapshot is made of a VM state info (its size is shown in
460 @code{info snapshots}) and a snapshot of every writable disk image.
461 The VM state info is stored in the first @code{qcow2} non removable
462 and writable block device. The disk image snapshots are stored in
463 every disk image. The size of a snapshot in a disk image is difficult
464 to evaluate and is not shown by @code{info snapshots} because the
465 associated disk sectors are shared among all the snapshots to save
466 disk space (otherwise each snapshot would need a full copy of all the
469 When using the (unrelated) @code{-snapshot} option
470 (@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
471 but they are deleted as soon as you exit QEMU.
473 VM snapshots currently have the following known limitations:
476 They cannot cope with removable devices if they are removed or
477 inserted after a snapshot is done.
479 A few device drivers still have incomplete snapshot support so their
480 state is not saved or restored properly (in particular USB).
483 @node qemu_img_invocation
484 @subsection @code{qemu-img} Invocation
486 @include qemu-img.texi
488 @node qemu_nbd_invocation
489 @subsection @code{qemu-nbd} Invocation
491 @include qemu-nbd.texi
493 @node qemu_ga_invocation
494 @subsection @code{qemu-ga} Invocation
496 @include qemu-ga.texi
498 @node disk_images_formats
499 @subsection Disk image file formats
501 QEMU supports many image file formats that can be used with VMs as well as with
502 any of the tools (like @code{qemu-img}). This includes the preferred formats
503 raw and qcow2 as well as formats that are supported for compatibility with
504 older QEMU versions or other hypervisors.
506 Depending on the image format, different options can be passed to
507 @code{qemu-img create} and @code{qemu-img convert} using the @code{-o} option.
508 This section describes each format and the options that are supported for it.
513 Raw disk image format. This format has the advantage of
514 being simple and easily exportable to all other emulators. If your
515 file system supports @emph{holes} (for example in ext2 or ext3 on
516 Linux or NTFS on Windows), then only the written sectors will reserve
517 space. Use @code{qemu-img info} to know the real size used by the
518 image or @code{ls -ls} on Unix/Linux.
523 Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}).
524 @code{falloc} mode preallocates space for image by calling posix_fallocate().
525 @code{full} mode preallocates space for image by writing zeros to underlying
530 QEMU image format, the most versatile format. Use it to have smaller
531 images (useful if your filesystem does not supports holes, for example
532 on Windows), zlib based compression and support of multiple VM
538 Determines the qcow2 version to use. @code{compat=0.10} uses the
539 traditional image format that can be read by any QEMU since 0.10.
540 @code{compat=1.1} enables image format extensions that only QEMU 1.1 and
541 newer understand (this is the default). Amongst others, this includes
542 zero clusters, which allow efficient copy-on-read for sparse images.
545 File name of a base image (see @option{create} subcommand)
547 Image format of the base image
549 If this option is set to @code{on}, the image is encrypted with 128-bit AES-CBC.
551 The use of encryption in qcow and qcow2 images is considered to be flawed by
552 modern cryptography standards, suffering from a number of design problems:
555 @item The AES-CBC cipher is used with predictable initialization vectors based
556 on the sector number. This makes it vulnerable to chosen plaintext attacks
557 which can reveal the existence of encrypted data.
558 @item The user passphrase is directly used as the encryption key. A poorly
559 chosen or short passphrase will compromise the security of the encryption.
560 @item In the event of the passphrase being compromised there is no way to
561 change the passphrase to protect data in any qcow images. The files must
562 be cloned, using a different encryption passphrase in the new file. The
563 original file must then be securely erased using a program like shred,
564 though even this is ineffective with many modern storage technologies.
567 Use of qcow / qcow2 encryption with QEMU is deprecated, and support for
568 it will go away in a future release. Users are recommended to use an
569 alternative encryption technology such as the Linux dm-crypt / LUKS
573 Changes the qcow2 cluster size (must be between 512 and 2M). Smaller cluster
574 sizes can improve the image file size whereas larger cluster sizes generally
575 provide better performance.
578 Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
579 @code{full}). An image with preallocated metadata is initially larger but can
580 improve performance when the image needs to grow. @code{falloc} and @code{full}
581 preallocations are like the same options of @code{raw} format, but sets up
585 If this option is set to @code{on}, reference count updates are postponed with
586 the goal of avoiding metadata I/O and improving performance. This is
587 particularly interesting with @option{cache=writethrough} which doesn't batch
588 metadata updates. The tradeoff is that after a host crash, the reference count
589 tables must be rebuilt, i.e. on the next open an (automatic) @code{qemu-img
590 check -r all} is required, which may take some time.
592 This option can only be enabled if @code{compat=1.1} is specified.
595 If this option is set to @code{on}, it will turn off COW of the file. It's only
596 valid on btrfs, no effect on other file systems.
598 Btrfs has low performance when hosting a VM image file, even more when the guest
599 on the VM also using btrfs as file system. Turning off COW is a way to mitigate
600 this bad performance. Generally there are two ways to turn off COW on btrfs:
601 a) Disable it by mounting with nodatacow, then all newly created files will be
602 NOCOW. b) For an empty file, add the NOCOW file attribute. That's what this option
605 Note: this option is only valid to new or empty files. If there is an existing
606 file which is COW and has data blocks already, it couldn't be changed to NOCOW
607 by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if
608 the NOCOW flag is set or not (Capital 'C' is NOCOW flag).
613 Old QEMU image format with support for backing files and compact image files
614 (when your filesystem or transport medium does not support holes).
616 When converting QED images to qcow2, you might want to consider using the
617 @code{lazy_refcounts=on} option to get a more QED-like behaviour.
622 File name of a base image (see @option{create} subcommand).
624 Image file format of backing file (optional). Useful if the format cannot be
625 autodetected because it has no header, like some vhd/vpc files.
627 Changes the cluster size (must be power-of-2 between 4K and 64K). Smaller
628 cluster sizes can improve the image file size whereas larger cluster sizes
629 generally provide better performance.
631 Changes the number of clusters per L1/L2 table (must be power-of-2 between 1
632 and 16). There is normally no need to change this value but this option can be
633 used for performance benchmarking.
637 Old QEMU image format with support for backing files, compact image files,
638 encryption and compression.
643 File name of a base image (see @option{create} subcommand)
645 If this option is set to @code{on}, the image is encrypted.
649 VirtualBox 1.1 compatible image format.
653 If this option is set to @code{on}, the image is created with metadata
658 VMware 3 and 4 compatible image format.
663 File name of a base image (see @option{create} subcommand).
665 Create a VMDK version 6 image (instead of version 4)
667 Specify vmdk virtual hardware version. Compat6 flag cannot be enabled
668 if hwversion is specified.
670 Specifies which VMDK subformat to use. Valid options are
671 @code{monolithicSparse} (default),
672 @code{monolithicFlat},
673 @code{twoGbMaxExtentSparse},
674 @code{twoGbMaxExtentFlat} and
675 @code{streamOptimized}.
679 VirtualPC compatible image format (VHD).
683 Specifies which VHD subformat to use. Valid options are
684 @code{dynamic} (default) and @code{fixed}.
688 Hyper-V compatible image format (VHDX).
692 Specifies which VHDX subformat to use. Valid options are
693 @code{dynamic} (default) and @code{fixed}.
694 @item block_state_zero
695 Force use of payload blocks of type 'ZERO'. Can be set to @code{on} (default)
696 or @code{off}. When set to @code{off}, new blocks will be created as
697 @code{PAYLOAD_BLOCK_NOT_PRESENT}, which means parsers are free to return
698 arbitrary data for those blocks. Do not set to @code{off} when using
699 @code{qemu-img convert} with @code{subformat=dynamic}.
701 Block size; min 1 MB, max 256 MB. 0 means auto-calculate based on image size.
707 @subsubsection Read-only formats
708 More disk image file formats are supported in a read-only mode.
711 Bochs images of @code{growing} type.
713 Linux Compressed Loop image, useful only to reuse directly compressed
714 CD-ROM images present for example in the Knoppix CD-ROMs.
718 Parallels disk image format.
723 @subsection Using host drives
725 In addition to disk image files, QEMU can directly access host
726 devices. We describe here the usage for QEMU version >= 0.8.3.
730 On Linux, you can directly use the host device filename instead of a
731 disk image filename provided you have enough privileges to access
732 it. For example, use @file{/dev/cdrom} to access to the CDROM.
736 You can specify a CDROM device even if no CDROM is loaded. QEMU has
737 specific code to detect CDROM insertion or removal. CDROM ejection by
738 the guest OS is supported. Currently only data CDs are supported.
740 You can specify a floppy device even if no floppy is loaded. Floppy
741 removal is currently not detected accurately (if you change floppy
742 without doing floppy access while the floppy is not loaded, the guest
743 OS will think that the same floppy is loaded).
744 Use of the host's floppy device is deprecated, and support for it will
745 be removed in a future release.
747 Hard disks can be used. Normally you must specify the whole disk
748 (@file{/dev/hdb} instead of @file{/dev/hdb1}) so that the guest OS can
749 see it as a partitioned disk. WARNING: unless you know what you do, it
750 is better to only make READ-ONLY accesses to the hard disk otherwise
751 you may corrupt your host data (use the @option{-snapshot} command
752 line option or modify the device permissions accordingly).
755 @subsubsection Windows
759 The preferred syntax is the drive letter (e.g. @file{d:}). The
760 alternate syntax @file{\\.\d:} is supported. @file{/dev/cdrom} is
761 supported as an alias to the first CDROM drive.
763 Currently there is no specific code to handle removable media, so it
764 is better to use the @code{change} or @code{eject} monitor commands to
765 change or eject media.
767 Hard disks can be used with the syntax: @file{\\.\PhysicalDrive@var{N}}
768 where @var{N} is the drive number (0 is the first hard disk).
769 @file{/dev/hda} is supported as an alias to
770 the first hard disk drive @file{\\.\PhysicalDrive0}.
772 WARNING: unless you know what you do, it is better to only make
773 READ-ONLY accesses to the hard disk otherwise you may corrupt your
774 host data (use the @option{-snapshot} command line so that the
775 modifications are written in a temporary file).
779 @subsubsection Mac OS X
781 @file{/dev/cdrom} is an alias to the first CDROM.
783 Currently there is no specific code to handle removable media, so it
784 is better to use the @code{change} or @code{eject} monitor commands to
785 change or eject media.
787 @node disk_images_fat_images
788 @subsection Virtual FAT disk images
790 QEMU can automatically create a virtual FAT disk image from a
791 directory tree. In order to use it, just type:
794 qemu-system-i386 linux.img -hdb fat:/my_directory
797 Then you access access to all the files in the @file{/my_directory}
798 directory without having to copy them in a disk image or to export
799 them via SAMBA or NFS. The default access is @emph{read-only}.
801 Floppies can be emulated with the @code{:floppy:} option:
804 qemu-system-i386 linux.img -fda fat:floppy:/my_directory
807 A read/write support is available for testing (beta stage) with the
811 qemu-system-i386 linux.img -fda fat:floppy:rw:/my_directory
814 What you should @emph{never} do:
816 @item use non-ASCII filenames ;
817 @item use "-snapshot" together with ":rw:" ;
818 @item expect it to work when loadvm'ing ;
819 @item write to the FAT directory on the host system while accessing it with the guest system.
822 @node disk_images_nbd
823 @subsection NBD access
825 QEMU can access directly to block device exported using the Network Block Device
829 qemu-system-i386 linux.img -hdb nbd://my_nbd_server.mydomain.org:1024/
832 If the NBD server is located on the same host, you can use an unix socket instead
836 qemu-system-i386 linux.img -hdb nbd+unix://?socket=/tmp/my_socket
839 In this case, the block device must be exported using qemu-nbd:
842 qemu-nbd --socket=/tmp/my_socket my_disk.qcow2
845 The use of qemu-nbd allows sharing of a disk between several guests:
847 qemu-nbd --socket=/tmp/my_socket --share=2 my_disk.qcow2
851 and then you can use it with two guests:
853 qemu-system-i386 linux1.img -hdb nbd+unix://?socket=/tmp/my_socket
854 qemu-system-i386 linux2.img -hdb nbd+unix://?socket=/tmp/my_socket
857 If the nbd-server uses named exports (supported since NBD 2.9.18, or with QEMU's
858 own embedded NBD server), you must specify an export name in the URI:
860 qemu-system-i386 -cdrom nbd://localhost/debian-500-ppc-netinst
861 qemu-system-i386 -cdrom nbd://localhost/openSUSE-11.1-ppc-netinst
864 The URI syntax for NBD is supported since QEMU 1.3. An alternative syntax is
865 also available. Here are some example of the older syntax:
867 qemu-system-i386 linux.img -hdb nbd:my_nbd_server.mydomain.org:1024
868 qemu-system-i386 linux2.img -hdb nbd:unix:/tmp/my_socket
869 qemu-system-i386 -cdrom nbd:localhost:10809:exportname=debian-500-ppc-netinst
872 @node disk_images_sheepdog
873 @subsection Sheepdog disk images
875 Sheepdog is a distributed storage system for QEMU. It provides highly
876 available block level storage volumes that can be attached to
877 QEMU-based virtual machines.
879 You can create a Sheepdog disk image with the command:
881 qemu-img create sheepdog:///@var{image} @var{size}
883 where @var{image} is the Sheepdog image name and @var{size} is its
886 To import the existing @var{filename} to Sheepdog, you can use a
889 qemu-img convert @var{filename} sheepdog:///@var{image}
892 You can boot from the Sheepdog disk image with the command:
894 qemu-system-i386 sheepdog:///@var{image}
897 You can also create a snapshot of the Sheepdog image like qcow2.
899 qemu-img snapshot -c @var{tag} sheepdog:///@var{image}
901 where @var{tag} is a tag name of the newly created snapshot.
903 To boot from the Sheepdog snapshot, specify the tag name of the
906 qemu-system-i386 sheepdog:///@var{image}#@var{tag}
909 You can create a cloned image from the existing snapshot.
911 qemu-img create -b sheepdog:///@var{base}#@var{tag} sheepdog:///@var{image}
913 where @var{base} is a image name of the source snapshot and @var{tag}
916 You can use an unix socket instead of an inet socket:
919 qemu-system-i386 sheepdog+unix:///@var{image}?socket=@var{path}
922 If the Sheepdog daemon doesn't run on the local host, you need to
923 specify one of the Sheepdog servers to connect to.
925 qemu-img create sheepdog://@var{hostname}:@var{port}/@var{image} @var{size}
926 qemu-system-i386 sheepdog://@var{hostname}:@var{port}/@var{image}
929 @node disk_images_iscsi
930 @subsection iSCSI LUNs
932 iSCSI is a popular protocol used to access SCSI devices across a computer
935 There are two different ways iSCSI devices can be used by QEMU.
937 The first method is to mount the iSCSI LUN on the host, and make it appear as
938 any other ordinary SCSI device on the host and then to access this device as a
939 /dev/sd device from QEMU. How to do this differs between host OSes.
941 The second method involves using the iSCSI initiator that is built into
942 QEMU. This provides a mechanism that works the same way regardless of which
943 host OS you are running QEMU on. This section will describe this second method
944 of using iSCSI together with QEMU.
946 In QEMU, iSCSI devices are described using special iSCSI URLs
950 iscsi://[<username>[%<password>]@@]<host>[:<port>]/<target-iqn-name>/<lun>
953 Username and password are optional and only used if your target is set up
954 using CHAP authentication for access control.
955 Alternatively the username and password can also be set via environment
956 variables to have these not show up in the process list
959 export LIBISCSI_CHAP_USERNAME=<username>
960 export LIBISCSI_CHAP_PASSWORD=<password>
961 iscsi://<host>/<target-iqn-name>/<lun>
964 Various session related parameters can be set via special options, either
965 in a configuration file provided via '-readconfig' or directly on the
968 If the initiator-name is not specified qemu will use a default name
969 of 'iqn.2008-11.org.linux-kvm[:<name>'] where <name> is the name of the
974 Setting a specific initiator name to use when logging in to the target
975 -iscsi initiator-name=iqn.qemu.test:my-initiator
979 Controlling which type of header digest to negotiate with the target
980 -iscsi header-digest=CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
983 These can also be set via a configuration file
986 user = "CHAP username"
987 password = "CHAP password"
988 initiator-name = "iqn.qemu.test:my-initiator"
989 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
990 header-digest = "CRC32C"
994 Setting the target name allows different options for different targets
996 [iscsi "iqn.target.name"]
997 user = "CHAP username"
998 password = "CHAP password"
999 initiator-name = "iqn.qemu.test:my-initiator"
1000 # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
1001 header-digest = "CRC32C"
1005 Howto use a configuration file to set iSCSI configuration options:
1007 cat >iscsi.conf <<EOF
1010 password = "my password"
1011 initiator-name = "iqn.qemu.test:my-initiator"
1012 header-digest = "CRC32C"
1015 qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1016 -readconfig iscsi.conf
1020 Howto set up a simple iSCSI target on loopback and accessing it via QEMU:
1022 This example shows how to set up an iSCSI target with one CDROM and one DISK
1023 using the Linux STGT software target. This target is available on Red Hat based
1024 systems as the package 'scsi-target-utils'.
1026 tgtd --iscsi portal=127.0.0.1:3260
1027 tgtadm --lld iscsi --op new --mode target --tid 1 -T iqn.qemu.test
1028 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 \
1029 -b /IMAGES/disk.img --device-type=disk
1030 tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 \
1031 -b /IMAGES/cd.iso --device-type=cd
1032 tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL
1034 qemu-system-i386 -iscsi initiator-name=iqn.qemu.test:my-initiator \
1035 -boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
1036 -cdrom iscsi://127.0.0.1/iqn.qemu.test/2
1039 @node disk_images_gluster
1040 @subsection GlusterFS disk images
1042 GlusterFS is an user space distributed file system.
1044 You can boot from the GlusterFS disk image with the command:
1047 qemu-system-x86_64 -drive file=gluster[+@var{type}]://[@var{host}[:@var{port}]]/@var{volume}/@var{path}
1048 [?socket=...][,file.debug=9][,file.logfile=...]
1051 qemu-system-x86_64 'json:@{"driver":"qcow2",
1052 "file":@{"driver":"gluster",
1053 "volume":"testvol","path":"a.img","debug":9,"logfile":"...",
1054 "server":[@{"type":"tcp","host":"...","port":"..."@},
1055 @{"type":"unix","socket":"..."@}]@}@}'
1058 @var{gluster} is the protocol.
1060 @var{type} specifies the transport type used to connect to gluster
1061 management daemon (glusterd). Valid transport types are
1062 tcp and unix. In the URI form, if a transport type isn't specified,
1063 then tcp type is assumed.
1065 @var{host} specifies the server where the volume file specification for
1066 the given volume resides. This can be either a hostname or an ipv4 address.
1067 If transport type is unix, then @var{host} field should not be specified.
1068 Instead @var{socket} field needs to be populated with the path to unix domain
1071 @var{port} is the port number on which glusterd is listening. This is optional
1072 and if not specified, it defaults to port 24007. If the transport type is unix,
1073 then @var{port} should not be specified.
1075 @var{volume} is the name of the gluster volume which contains the disk image.
1077 @var{path} is the path to the actual disk image that resides on gluster volume.
1079 @var{debug} is the logging level of the gluster protocol driver. Debug levels
1080 are 0-9, with 9 being the most verbose, and 0 representing no debugging output.
1081 The default level is 4. The current logging levels defined in the gluster source
1082 are 0 - None, 1 - Emergency, 2 - Alert, 3 - Critical, 4 - Error, 5 - Warning,
1083 6 - Notice, 7 - Info, 8 - Debug, 9 - Trace
1085 @var{logfile} is a commandline option to mention log file path which helps in
1086 logging to the specified file and also help in persisting the gfapi logs. The
1092 You can create a GlusterFS disk image with the command:
1094 qemu-img create gluster://@var{host}/@var{volume}/@var{path} @var{size}
1099 qemu-system-x86_64 -drive file=gluster://1.2.3.4/testvol/a.img
1100 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4/testvol/a.img
1101 qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img
1102 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
1103 qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img
1104 qemu-system-x86_64 -drive file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img
1105 qemu-system-x86_64 -drive file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
1106 qemu-system-x86_64 -drive file=gluster+rdma://1.2.3.4:24007/testvol/a.img
1107 qemu-system-x86_64 -drive file=gluster://1.2.3.4/testvol/a.img,file.debug=9,file.logfile=/var/log/qemu-gluster.log
1108 qemu-system-x86_64 'json:@{"driver":"qcow2",
1109 "file":@{"driver":"gluster",
1110 "volume":"testvol","path":"a.img",
1111 "debug":9,"logfile":"/var/log/qemu-gluster.log",
1112 "server":[@{"type":"tcp","host":"1.2.3.4","port":24007@},
1113 @{"type":"unix","socket":"/var/run/glusterd.socket"@}]@}@}'
1114 qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
1115 file.debug=9,file.logfile=/var/log/qemu-gluster.log,
1116 file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
1117 file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket
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 emulator is still a work in progress.
2140 The Niagara T1 emulator makes use of firmware and OS binaries supplied in the S10image/ directory
2141 of the OpenSPARC T1 project @url{http://download.oracle.com/technetwork/systems/opensparc/OpenSPARCT1_Arch.1.5.tar.bz2}
2142 and is able to boot the disk.s10hw2 Solaris image.
2144 qemu-system-sparc64 -M niagara -L /path-to/S10image/ \
2146 -drive if=pflash,readonly=on,file=/S10image/disk.s10hw2
2150 QEMU emulates the following peripherals:
2154 UltraSparc IIi APB PCI Bridge
2156 PCI VGA compatible card with VESA Bochs Extensions
2158 PS/2 mouse and keyboard
2160 Non Volatile RAM M48T59
2162 PC-compatible serial ports
2164 2 PCI IDE interfaces with hard disk and CD-ROM support
2169 @c man begin OPTIONS
2171 The following options are specific to the Sparc64 emulation:
2175 @item -prom-env @var{string}
2177 Set OpenBIOS variables in NVRAM, for example:
2180 qemu-system-sparc64 -prom-env 'auto-boot?=false'
2183 @item -M [sun4u|sun4v|niagara]
2185 Set the emulated machine type. The default is sun4u.
2191 @node MIPS System emulator
2192 @section MIPS System emulator
2193 @cindex system emulation (MIPS)
2195 Four executables cover simulation of 32 and 64-bit MIPS systems in
2196 both endian options, @file{qemu-system-mips}, @file{qemu-system-mipsel}
2197 @file{qemu-system-mips64} and @file{qemu-system-mips64el}.
2198 Five different machine types are emulated:
2202 A generic ISA PC-like machine "mips"
2204 The MIPS Malta prototype board "malta"
2206 An ACER Pica "pica61". This machine needs the 64-bit emulator.
2208 MIPS emulator pseudo board "mipssim"
2210 A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator.
2213 The generic emulation is supported by Debian 'Etch' and is able to
2214 install Debian into a virtual disk image. The following devices are
2219 A range of MIPS CPUs, default is the 24Kf
2221 PC style serial port
2228 The Malta emulation supports the following devices:
2232 Core board with MIPS 24Kf CPU and Galileo system controller
2234 PIIX4 PCI/USB/SMbus controller
2236 The Multi-I/O chip's serial device
2238 PCI network cards (PCnet32 and others)
2240 Malta FPGA serial device
2242 Cirrus (default) or any other PCI VGA graphics card
2245 The ACER Pica emulation supports:
2251 PC-style IRQ and DMA controllers
2258 The mipssim pseudo board emulation provides an environment similar
2259 to what the proprietary MIPS emulator uses for running Linux.
2264 A range of MIPS CPUs, default is the 24Kf
2266 PC style serial port
2268 MIPSnet network emulation
2271 The MIPS Magnum R4000 emulation supports:
2277 PC-style IRQ controller
2287 @node ARM System emulator
2288 @section ARM System emulator
2289 @cindex system emulation (ARM)
2291 Use the executable @file{qemu-system-arm} to simulate a ARM
2292 machine. The ARM Integrator/CP board is emulated with the following
2297 ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU
2301 SMC 91c111 Ethernet adapter
2303 PL110 LCD controller
2305 PL050 KMI with PS/2 keyboard and mouse.
2307 PL181 MultiMedia Card Interface with SD card.
2310 The ARM Versatile baseboard is emulated with the following devices:
2314 ARM926E, ARM1136 or Cortex-A8 CPU
2316 PL190 Vectored Interrupt Controller
2320 SMC 91c111 Ethernet adapter
2322 PL110 LCD controller
2324 PL050 KMI with PS/2 keyboard and mouse.
2326 PCI host bridge. Note the emulated PCI bridge only provides access to
2327 PCI memory space. It does not provide access to PCI IO space.
2328 This means some devices (eg. ne2k_pci NIC) are not usable, and others
2329 (eg. rtl8139 NIC) are only usable when the guest drivers use the memory
2330 mapped control registers.
2332 PCI OHCI USB controller.
2334 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
2336 PL181 MultiMedia Card Interface with SD card.
2339 Several variants of the ARM RealView baseboard are emulated,
2340 including the EB, PB-A8 and PBX-A9. Due to interactions with the
2341 bootloader, only certain Linux kernel configurations work out
2342 of the box on these boards.
2344 Kernels for the PB-A8 board should have CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2345 enabled in the kernel, and expect 512M RAM. Kernels for The PBX-A9 board
2346 should have CONFIG_SPARSEMEM enabled, CONFIG_REALVIEW_HIGH_PHYS_OFFSET
2347 disabled and expect 1024M RAM.
2349 The following devices are emulated:
2353 ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU
2355 ARM AMBA Generic/Distributed Interrupt Controller
2359 SMC 91c111 or SMSC LAN9118 Ethernet adapter
2361 PL110 LCD controller
2363 PL050 KMI with PS/2 keyboard and mouse
2367 PCI OHCI USB controller
2369 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
2371 PL181 MultiMedia Card Interface with SD card.
2374 The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
2375 and "Terrier") emulation includes the following peripherals:
2379 Intel PXA270 System-on-chip (ARM V5TE core)
2383 IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
2385 On-chip OHCI USB controller
2387 On-chip LCD controller
2389 On-chip Real Time Clock
2391 TI ADS7846 touchscreen controller on SSP bus
2393 Maxim MAX1111 analog-digital converter on I@math{^2}C bus
2395 GPIO-connected keyboard controller and LEDs
2397 Secure Digital card connected to PXA MMC/SD host
2401 WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
2404 The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the
2409 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2411 ROM and RAM memories (ROM firmware image can be loaded with -option-rom)
2413 On-chip LCD controller
2415 On-chip Real Time Clock
2417 TI TSC2102i touchscreen controller / analog-digital converter / Audio
2418 CODEC, connected through MicroWire and I@math{^2}S busses
2420 GPIO-connected matrix keypad
2422 Secure Digital card connected to OMAP MMC/SD host
2427 Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48)
2428 emulation supports the following elements:
2432 Texas Instruments OMAP2420 System-on-chip (ARM 1136 core)
2434 RAM and non-volatile OneNAND Flash memories
2436 Display connected to EPSON remote framebuffer chip and OMAP on-chip
2437 display controller and a LS041y3 MIPI DBI-C controller
2439 TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers
2440 driven through SPI bus
2442 National Semiconductor LM8323-controlled qwerty keyboard driven
2443 through I@math{^2}C bus
2445 Secure Digital card connected to OMAP MMC/SD host
2447 Three OMAP on-chip UARTs and on-chip STI debugging console
2449 A Bluetooth(R) transceiver and HCI connected to an UART
2451 Mentor Graphics "Inventra" dual-role USB controller embedded in a TI
2452 TUSB6010 chip - only USB host mode is supported
2454 TI TMP105 temperature sensor driven through I@math{^2}C bus
2456 TI TWL92230C power management companion with an RTC on I@math{^2}C bus
2458 Nokia RETU and TAHVO multi-purpose chips with an RTC, connected
2462 The Luminary Micro Stellaris LM3S811EVB emulation includes the following
2469 64k Flash and 8k SRAM.
2471 Timers, UARTs, ADC and I@math{^2}C interface.
2473 OSRAM Pictiva 96x16 OLED with SSD0303 controller on I@math{^2}C bus.
2476 The Luminary Micro Stellaris LM3S6965EVB emulation includes the following
2483 256k Flash and 64k SRAM.
2485 Timers, UARTs, ADC, I@math{^2}C and SSI interfaces.
2487 OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI.
2490 The Freecom MusicPal internet radio emulation includes the following
2495 Marvell MV88W8618 ARM core.
2497 32 MB RAM, 256 KB SRAM, 8 MB flash.
2501 MV88W8xx8 Ethernet controller
2503 MV88W8618 audio controller, WM8750 CODEC and mixer
2505 128×64 display with brightness control
2507 2 buttons, 2 navigation wheels with button function
2510 The Siemens SX1 models v1 and v2 (default) basic emulation.
2511 The emulation includes the following elements:
2515 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2517 ROM and RAM memories (ROM firmware image can be loaded with -pflash)
2519 1 Flash of 16MB and 1 Flash of 8MB
2523 On-chip LCD controller
2525 On-chip Real Time Clock
2527 Secure Digital card connected to OMAP MMC/SD host
2532 A Linux 2.6 test image is available on the QEMU web site. More
2533 information is available in the QEMU mailing-list archive.
2535 @c man begin OPTIONS
2537 The following options are specific to the ARM emulation:
2542 Enable semihosting syscall emulation.
2544 On ARM this implements the "Angel" interface.
2546 Note that this allows guest direct access to the host filesystem,
2547 so should only be used with trusted guest OS.
2551 @node ColdFire System emulator
2552 @section ColdFire System emulator
2553 @cindex system emulation (ColdFire)
2554 @cindex system emulation (M68K)
2556 Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2557 The emulator is able to boot a uClinux kernel.
2559 The M5208EVB emulation includes the following devices:
2563 MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2565 Three Two on-chip UARTs.
2567 Fast Ethernet Controller (FEC)
2570 The AN5206 emulation includes the following devices:
2574 MCF5206 ColdFire V2 Microprocessor.
2579 @c man begin OPTIONS
2581 The following options are specific to the ColdFire emulation:
2586 Enable semihosting syscall emulation.
2588 On M68K this implements the "ColdFire GDB" interface used by libgloss.
2590 Note that this allows guest direct access to the host filesystem,
2591 so should only be used with trusted guest OS.
2595 @node Cris System emulator
2596 @section Cris System emulator
2597 @cindex system emulation (Cris)
2601 @node Microblaze System emulator
2602 @section Microblaze System emulator
2603 @cindex system emulation (Microblaze)
2607 @node SH4 System emulator
2608 @section SH4 System emulator
2609 @cindex system emulation (SH4)
2613 @node Xtensa System emulator
2614 @section Xtensa System emulator
2615 @cindex system emulation (Xtensa)
2617 Two executables cover simulation of both Xtensa endian options,
2618 @file{qemu-system-xtensa} and @file{qemu-system-xtensaeb}.
2619 Two different machine types are emulated:
2623 Xtensa emulator pseudo board "sim"
2625 Avnet LX60/LX110/LX200 board
2628 The sim pseudo board emulation provides an environment similar
2629 to one provided by the proprietary Tensilica ISS.
2634 A range of Xtensa CPUs, default is the DC232B
2636 Console and filesystem access via semihosting calls
2639 The Avnet LX60/LX110/LX200 emulation supports:
2643 A range of Xtensa CPUs, default is the DC232B
2647 OpenCores 10/100 Mbps Ethernet MAC
2650 @c man begin OPTIONS
2652 The following options are specific to the Xtensa emulation:
2657 Enable semihosting syscall emulation.
2659 Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select.
2660 Tensilica baremetal libc for ISS and linux platform "sim" use this interface.
2662 Note that this allows guest direct access to the host filesystem,
2663 so should only be used with trusted guest OS.
2666 @node QEMU User space emulator
2667 @chapter QEMU User space emulator
2670 * Supported Operating Systems ::
2672 * Linux User space emulator::
2673 * BSD User space emulator ::
2676 @node Supported Operating Systems
2677 @section Supported Operating Systems
2679 The following OS are supported in user space emulation:
2683 Linux (referred as qemu-linux-user)
2685 BSD (referred as qemu-bsd-user)
2691 QEMU user space emulation has the following notable features:
2694 @item System call translation:
2695 QEMU includes a generic system call translator. This means that
2696 the parameters of the system calls can be converted to fix
2697 endianness and 32/64-bit mismatches between hosts and targets.
2698 IOCTLs can be converted too.
2700 @item POSIX signal handling:
2701 QEMU can redirect to the running program all signals coming from
2702 the host (such as @code{SIGALRM}), as well as synthesize signals from
2703 virtual CPU exceptions (for example @code{SIGFPE} when the program
2704 executes a division by zero).
2706 QEMU relies on the host kernel to emulate most signal system
2707 calls, for example to emulate the signal mask. On Linux, QEMU
2708 supports both normal and real-time signals.
2711 On Linux, QEMU can emulate the @code{clone} syscall and create a real
2712 host thread (with a separate virtual CPU) for each emulated thread.
2713 Note that not all targets currently emulate atomic operations correctly.
2714 x86 and ARM use a global lock in order to preserve their semantics.
2717 QEMU was conceived so that ultimately it can emulate itself. Although
2718 it is not very useful, it is an important test to show the power of the
2721 @node Linux User space emulator
2722 @section Linux User space emulator
2727 * Command line options::
2732 @subsection Quick Start
2734 In order to launch a Linux process, QEMU needs the process executable
2735 itself and all the target (x86) dynamic libraries used by it.
2739 @item On x86, you can just try to launch any process by using the native
2743 qemu-i386 -L / /bin/ls
2746 @code{-L /} tells that the x86 dynamic linker must be searched with a
2749 @item Since QEMU is also a linux process, you can launch QEMU with
2750 QEMU (NOTE: you can only do that if you compiled QEMU from the sources):
2753 qemu-i386 -L / qemu-i386 -L / /bin/ls
2756 @item On non x86 CPUs, you need first to download at least an x86 glibc
2757 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2758 @code{LD_LIBRARY_PATH} is not set:
2761 unset LD_LIBRARY_PATH
2764 Then you can launch the precompiled @file{ls} x86 executable:
2767 qemu-i386 tests/i386/ls
2769 You can look at @file{scripts/qemu-binfmt-conf.sh} so that
2770 QEMU is automatically launched by the Linux kernel when you try to
2771 launch x86 executables. It requires the @code{binfmt_misc} module in the
2774 @item The x86 version of QEMU is also included. You can try weird things such as:
2776 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2777 /usr/local/qemu-i386/bin/ls-i386
2783 @subsection Wine launch
2787 @item Ensure that you have a working QEMU with the x86 glibc
2788 distribution (see previous section). In order to verify it, you must be
2792 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2795 @item Download the binary x86 Wine install
2796 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2798 @item Configure Wine on your account. Look at the provided script
2799 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2800 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2802 @item Then you can try the example @file{putty.exe}:
2805 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2806 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2811 @node Command line options
2812 @subsection Command line options
2815 @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}...]
2822 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2824 Set the x86 stack size in bytes (default=524288)
2826 Select CPU model (-cpu help for list and additional feature selection)
2827 @item -E @var{var}=@var{value}
2828 Set environment @var{var} to @var{value}.
2830 Remove @var{var} from the environment.
2832 Offset guest address by the specified number of bytes. This is useful when
2833 the address region required by guest applications is reserved on the host.
2834 This option is currently only supported on some hosts.
2836 Pre-allocate a guest virtual address space of the given size (in bytes).
2837 "G", "M", and "k" suffixes may be used when specifying the size.
2844 Activate logging of the specified items (use '-d help' for a list of log items)
2846 Act as if the host page size was 'pagesize' bytes
2848 Wait gdb connection to port
2850 Run the emulation in single step mode.
2853 Environment variables:
2857 Print system calls and arguments similar to the 'strace' program
2858 (NOTE: the actual 'strace' program will not work because the user
2859 space emulator hasn't implemented ptrace). At the moment this is
2860 incomplete. All system calls that don't have a specific argument
2861 format are printed with information for six arguments. Many
2862 flag-style arguments don't have decoders and will show up as numbers.
2865 @node Other binaries
2866 @subsection Other binaries
2868 @cindex user mode (Alpha)
2869 @command{qemu-alpha} TODO.
2871 @cindex user mode (ARM)
2872 @command{qemu-armeb} TODO.
2874 @cindex user mode (ARM)
2875 @command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2876 binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2877 configurations), and arm-uclinux bFLT format binaries.
2879 @cindex user mode (ColdFire)
2880 @cindex user mode (M68K)
2881 @command{qemu-m68k} is capable of running semihosted binaries using the BDM
2882 (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2883 coldfire uClinux bFLT format binaries.
2885 The binary format is detected automatically.
2887 @cindex user mode (Cris)
2888 @command{qemu-cris} TODO.
2890 @cindex user mode (i386)
2891 @command{qemu-i386} TODO.
2892 @command{qemu-x86_64} TODO.
2894 @cindex user mode (Microblaze)
2895 @command{qemu-microblaze} TODO.
2897 @cindex user mode (MIPS)
2898 @command{qemu-mips} TODO.
2899 @command{qemu-mipsel} TODO.
2901 @cindex user mode (PowerPC)
2902 @command{qemu-ppc64abi32} TODO.
2903 @command{qemu-ppc64} TODO.
2904 @command{qemu-ppc} TODO.
2906 @cindex user mode (SH4)
2907 @command{qemu-sh4eb} TODO.
2908 @command{qemu-sh4} TODO.
2910 @cindex user mode (SPARC)
2911 @command{qemu-sparc} can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).
2913 @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2914 (Sparc64 CPU, 32 bit ABI).
2916 @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2917 SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2919 @node BSD User space emulator
2920 @section BSD User space emulator
2925 * BSD Command line options::
2929 @subsection BSD Status
2933 target Sparc64 on Sparc64: Some trivial programs work.
2936 @node BSD Quick Start
2937 @subsection Quick Start
2939 In order to launch a BSD process, QEMU needs the process executable
2940 itself and all the target dynamic libraries used by it.
2944 @item On Sparc64, you can just try to launch any process by using the native
2948 qemu-sparc64 /bin/ls
2953 @node BSD Command line options
2954 @subsection Command line options
2957 @command{qemu-sparc64} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-bsd} @var{type}] @var{program} [@var{arguments}...]
2964 Set the library root path (default=/)
2966 Set the stack size in bytes (default=524288)
2967 @item -ignore-environment
2968 Start with an empty environment. Without this option,
2969 the initial environment is a copy of the caller's environment.
2970 @item -E @var{var}=@var{value}
2971 Set environment @var{var} to @var{value}.
2973 Remove @var{var} from the environment.
2975 Set the type of the emulated BSD Operating system. Valid values are
2976 FreeBSD, NetBSD and OpenBSD (default).
2983 Activate logging of the specified items (use '-d help' for a list of log items)
2985 Act as if the host page size was 'pagesize' bytes
2987 Run the emulation in single step mode.
2991 @include qemu-tech.texi
2996 QEMU is a trademark of Fabrice Bellard.
2998 QEMU is released under the GNU General Public License (TODO: add link).
2999 Parts of QEMU have specific licenses, see file LICENSE.
3001 TODO (refer to file LICENSE, include it, include the GPL?)
3015 @section Concept Index
3016 This is the main index. Should we combine all keywords in one index? TODO
3019 @node Function Index
3020 @section Function Index
3021 This index could be used for command line options and monitor functions.
3024 @node Keystroke Index
3025 @section Keystroke Index
3027 This is a list of all keystrokes which have a special function
3028 in system emulation.
3033 @section Program Index
3036 @node Data Type Index
3037 @section Data Type Index
3039 This index could be used for qdev device names and options.
3043 @node Variable Index
3044 @section Variable Index