Introduction
************

Features
========

QEMU is a FAST! processor emulator using dynamic translation to achieve good emulation speed.

QEMU has two operating modes:

  * Full system emulation. In this mode, QEMU emulates a full system (for example a PC), including one or several processors and various peripherals. It can be used to launch different Operating Systems without rebooting the PC or to debug system code.

  * User mode emulation. In this mode, QEMU can launch processes compiled for one CPU on another CPU. It can be used to launch the Wine Windows API emulator (http://www.winehq.org) or to ease cross-compilation and cross-debugging.

QEMU can run without a host kernel driver and yet gives acceptable performance.

For system emulation, the following hardware targets are supported:

  * PC (x86 or x86_64 processor)

  * ISA PC (old style PC without PCI bus)

  * PREP (PowerPC processor)

  * G3 Beige PowerMac (PowerPC processor)

  * Mac99 PowerMac (PowerPC processor, in progress)

  * Sun4m/Sun4c/Sun4d (32-bit Sparc processor)

  * Sun4u/Sun4v (64-bit Sparc processor, in progress)

  * Malta board (32-bit and 64-bit MIPS processors)

  * MIPS Magnum (64-bit MIPS processor)

  * ARM Integrator/CP (ARM)

  * ARM Versatile baseboard (ARM)

  * ARM RealView Emulation/Platform baseboard (ARM)

  * Spitz, Akita, Borzoi, Terrier and Tosa PDAs (PXA270 processor)

  * Luminary Micro LM3S811EVB (ARM Cortex-M3)

  * Luminary Micro LM3S6965EVB (ARM Cortex-M3)

  * Freescale MCF5208EVB (ColdFire V2).

  * Arnewsh MCF5206 evaluation board (ColdFire V2).

  * Palm Tungsten|E PDA (OMAP310 processor)

  * N800 and N810 tablets (OMAP2420 processor)

  * MusicPal (MV88W8618 ARM processor)

  * Gumstix "Connex" and "Verdex" motherboards (PXA255/270).

  * Siemens SX1 smartphone (OMAP310 processor)

  * AXIS-Devboard88 (CRISv32 ETRAX-FS).

  * Petalogix Spartan 3aDSP1800 MMU ref design (MicroBlaze).

  * Avnet LX60/LX110/LX200 boards (Xtensa)

For user emulation, x86 (32 and 64 bit), PowerPC (32 and 64 bit), ARM, MIPS (32 bit only), Sparc (32 and 64 bit), Alpha, ColdFire(m68k), CRISv32 and MicroBlaze CPUs are supported.

Installation
************

If you want to compile QEMU yourself, see compilation.

Linux
=====

If a precompiled package is available for your distribution - you just have to install it. Otherwise, see compilation.

Windows
=======

Download the experimental binary installer at http://www.free.oszoo.org/download.html. TODO (no longer available)

Mac OS X
========

Download the experimental binary installer at http://www.free.oszoo.org/download.html. TODO (no longer available)

QEMU PC System emulator
***********************

Introduction
============

The QEMU PC System emulator simulates the following peripherals:

  - i440FX host PCI bridge and PIIX3 PCI to ISA bridge

  - Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA extensions (hardware level, including all non standard modes).

  - PS/2 mouse and keyboard

  - 2 PCI IDE interfaces with hard disk and CD-ROM support

  - Floppy disk

  - PCI and ISA network adapters

  - Serial ports

  - Creative SoundBlaster 16 sound card

  - ENSONIQ AudioPCI ES1370 sound card

  - Intel 82801AA AC97 Audio compatible sound card

  - Intel HD Audio Controller and HDA codec

  - Adlib (OPL2) - Yamaha YM3812 compatible chip

  - Gravis Ultrasound GF1 sound card

  - CS4231A compatible sound card

  - PCI UHCI USB controller and a virtual USB hub.

SMP is supported with up to 255 CPUs.

QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs LGPL VGA BIOS.

QEMU uses YM3812 emulation by Tatsuyuki Satoh.

QEMU uses GUS emulation (GUSEMU32 http://www.deinmeister.de/gusemu/) by Tibor "TS" Schütz.

Note that, by default, GUS shares IRQ(7) with parallel ports and so QEMU must be told to not have parallel ports to have working GUS.

     qemu-system-i386 dos.img -soundhw gus -parallel none

Alternatively:

     qemu-system-i386 dos.img -device gus,irq=5

Or some other unclaimed IRQ.

CS4231A is the chip used in Windows Sound System and GUSMAX products

Quick Start
===========

Download and uncompress the linux image (linux.img) and type:

     qemu-system-i386 linux.img

Linux should boot and give you a prompt.

Invocation
==========

     usage: qemu-system-i386 [options] [DISK_IMAGE]

DISK_IMAGE is a raw hard disk image for IDE hard disk 0. Some targets do not need a disk image.

     [file qemu-options.texi not included]

Keys
====

During the graphical emulation, you can use special key combinations to change modes. The default key mappings are shown below, but if you use -alt-grab then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use -ctrl-grab then the modifier is the right Ctrl key (instead of Ctrl-Alt):

Ctrl-Alt-f
     Toggle full screen

Ctrl-Alt-+
     Enlarge the screen

Ctrl-Alt--
     Shrink the screen

Ctrl-Alt-u
     Restore the screen's un-scaled dimensions

Ctrl-Alt-n
     Switch to virtual console 'n'. Standard console mappings are:

     1
          Target system display

     2
          Monitor

     3
          Serial port

Ctrl-Alt
     Toggle mouse and keyboard grab.

In the virtual consoles, you can use Ctrl-Up, Ctrl-Down, Ctrl-PageUp and Ctrl-PageDown to move in the back log.

During emulation, if you are using the -nographic option, use Ctrl-a h to get terminal commands:

Ctrl-a h

Ctrl-a ?
     Print this help

Ctrl-a x
     Exit emulator

Ctrl-a s
     Save disk data back to file (if -snapshot)

Ctrl-a t
     Toggle console timestamps

Ctrl-a b
     Send break (magic sysrq in Linux)

Ctrl-a c
     Switch between console and monitor

Ctrl-a Ctrl-a
     Send Ctrl-a

QEMU Monitor
============

The QEMU monitor is used to give complex commands to the QEMU emulator. You can use it to:

  - Remove or insert removable media images (such as CD-ROM or floppies).

  - Freeze/unfreeze the Virtual Machine (VM) and save or restore its state from a disk file.

  - Inspect the VM state without an external debugger.

Commands
--------

The following commands are available:

     [file qemu-monitor.texi not included]

Integer expressions
-------------------

The monitor understands integers expressions for every integer argument. You can use register names to get the value of specifics CPU registers by prefixing them with $.

Disk Images
===========

Since version 0.6.1, QEMU supports many disk image formats, including growable disk images (their size increase as non empty sectors are written), compressed and encrypted disk images. Version 0.8.3 added the new qcow2 disk image format which is essential to support VM snapshots.

Quick start for disk image creation
-----------------------------------

You can create a disk image with the command:

     qemu-img create myimage.img mysize

where MYIMAGE.IMG is the disk image filename and MYSIZE is its size in kilobytes. You can add an M suffix to give the size in megabytes and a G suffix for gigabytes.

See qemu_img_invocation for more information.

Snapshot mode
-------------

If you use the option -snapshot, all disk images are considered as read only. When sectors in written, they are written in a temporary file created in /tmp. You can however force the write back to the raw disk images by using the commit monitor command (or C-a s in the serial console).

VM snapshots
------------

VM snapshots are snapshots of the complete virtual machine including CPU state, RAM, device state and the content of all the writable disks. In order to use VM snapshots, you must have at least one non removable and writable block device using the qcow2 disk image format. Normally this device is the first virtual hard drive.

Use the monitor command savevm to create a new VM snapshot or replace an existing one. A human readable name can be assigned to each snapshot in addition to its numerical ID.

Use loadvm to restore a VM snapshot and delvm to remove a VM snapshot. info snapshots lists the available snapshots with their associated information:

     (qemu) info snapshots
     Snapshot devices: hda
     Snapshot list (from hda):
     ID        TAG                 VM SIZE                DATE       VM CLOCK
     1         start                   41M 2006-08-06 12:38:02   00:00:14.954
     2                                 40M 2006-08-06 12:43:29   00:00:18.633
     3         msys                    40M 2006-08-06 12:44:04   00:00:23.514

A VM snapshot is made of a VM state info (its size is shown in info snapshots) and a snapshot of every writable disk image. The VM state info is stored in the first qcow2 non removable and writable block device. The disk image snapshots are stored in every disk image. The size of a snapshot in a disk image is difficult to evaluate and is not shown by info snapshots because the associated disk sectors are shared among all the snapshots to save disk space (otherwise each snapshot would need a full copy of all the disk images).

When using the (unrelated) -snapshot option (disk_images_snapshot_mode), you can always make VM snapshots, but they are deleted as soon as you exit QEMU.

VM snapshots currently have the following known limitations:

  * They cannot cope with removable devices if they are removed or inserted after a snapshot is done.

  * A few device drivers still have incomplete snapshot support so their state is not saved or restored properly (in particular USB).

qemu-img Invocation
-------------------

     [file qemu-img.texi not included]

qemu-nbd Invocation
-------------------

     [file qemu-nbd.texi not included]

Disk image file formats
-----------------------

QEMU supports many image file formats that can be used with VMs as well as with any of the tools (like qemu-img). This includes the preferred formats raw and qcow2 as well as formats that are supported for compatibility with older QEMU versions or other hypervisors.

Depending on the image format, different options can be passed to qemu-img create and qemu-img convert using the -o option. This section describes each format and the options that are supported for it.

raw

     Raw disk image format. This format has the advantage of being simple and easily exportable to all other emulators. If your file system supports holes (for example in ext2 or ext3 on Linux or NTFS on Windows), then only the written sectors will reserve space. Use qemu-img info to know the real size used by the image or ls -ls on Unix/Linux.

qcow2
     QEMU image format, the most versatile format. Use it to have smaller images (useful if your filesystem does not supports holes, for example on Windows), optional AES encryption, zlib based compression and support of multiple VM snapshots.

     Supported options:

     compat
          Determines the qcow2 version to use. compat=0.10 uses the traditional image format that can be read by any QEMU since 0.10. compat=1.1 enables image format extensions that only QEMU 1.1 and newer understand (this is the default). Amongst others, this includes zero clusters, which allow efficient copy-on-read for sparse images.

     backing_file
          File name of a base image (see create subcommand)

     backing_fmt
          Image format of the base image

     encryption
          If this option is set to on, the image is encrypted with 128-bit AES-CBC.

          The use of encryption in qcow and qcow2 images is considered to be flawed by modern cryptography standards, suffering from a number of design problems:

            - The AES-CBC cipher is used with predictable initialization vectors based on the sector number. This makes it vulnerable to chosen plaintext attacks which can reveal the existence of encrypted data.

            - The user passphrase is directly used as the encryption key. A poorly chosen or short passphrase will compromise the security of the encryption.

            - In the event of the passphrase being compromised there is no way to change the passphrase to protect data in any qcow images. The files must be cloned, using a different encryption passphrase in the new file. The original file must then be securely erased using a program like shred, though even this is ineffective with many modern storage technologies.

          Use of qcow / qcow2 encryption is thus strongly discouraged. Users are recommended to use an alternative encryption technology such as the Linux dm-crypt / LUKS system.

     cluster_size
          Changes the qcow2 cluster size (must be between 512 and 2M). Smaller cluster sizes can improve the image file size whereas larger cluster sizes generally provide better performance.

     preallocation
          Preallocation mode (allowed values: off, metadata). An image with preallocated metadata is initially larger but can improve performance when the image needs to grow.

     lazy_refcounts
          If this option is set to on, reference count updates are postponed with the goal of avoiding metadata I/O and improving performance. This is particularly interesting with cache=writethrough which doesn't batch metadata updates. The tradeoff is that after a host crash, the reference count tables must be rebuilt, i.e. on the next open an (automatic) qemu-img check -r all is required, which may take some time.

          This option can only be enabled if compat=1.1 is specified.

     nocow
          If this option is set to on, it will trun off COW of the file. It's only valid on btrfs, no effect on other file systems.

          Btrfs has low performance when hosting a VM image file, even more when the guest on the VM also using btrfs as file system. Turning off COW is a way to mitigate this bad performance. Generally there are two ways to turn off COW on btrfs: a) Disable it by mounting with nodatacow, then all newly created files will be NOCOW. b) For an empty file, add the NOCOW file attribute. That's what this option does.

          Note: this option is only valid to new or empty files. If there is an existing file which is COW and has data blocks already, it couldn't be changed to NOCOW by setting nocow=on. One can issue lsattr filename to check if the NOCOW flag is set or not (Capitabl 'C' is NOCOW flag).

qed
     Old QEMU image format with support for backing files and compact image files (when your filesystem or transport medium does not support holes).

     When converting QED images to qcow2, you might want to consider using the lazy_refcounts=on option to get a more QED-like behaviour.

     Supported options:

     backing_file
          File name of a base image (see create subcommand).

     backing_fmt
          Image file format of backing file (optional).  Useful if the format cannot be autodetected because it has no header, like some vhd/vpc files.

     cluster_size
          Changes the cluster size (must be power-of-2 between 4K and 64K). Smaller cluster sizes can improve the image file size whereas larger cluster sizes generally provide better performance.

     table_size
          Changes the number of clusters per L1/L2 table (must be power-of-2 between 1 and 16).  There is normally no need to change this value but this option can be used for performance benchmarking.

qcow
     Old QEMU image format with support for backing files, compact image files, encryption and compression.

     Supported options:

     backing_file
          File name of a base image (see create subcommand)

     encryption
          If this option is set to on, the image is encrypted.

cow
     User Mode Linux Copy On Write image format. It is supported only for compatibility with previous versions. Supported options:

     backing_file
          File name of a base image (see create subcommand)

vdi
     VirtualBox 1.1 compatible image format. Supported options:

     static
          If this option is set to on, the image is created with metadata preallocation.

vmdk
     VMware 3 and 4 compatible image format.

     Supported options:

     backing_file
          File name of a base image (see create subcommand).

     compat6
          Create a VMDK version 6 image (instead of version 4)

     subformat
          Specifies which VMDK subformat to use. Valid options are monolithicSparse (default), monolithicFlat, twoGbMaxExtentSparse, twoGbMaxExtentFlat and streamOptimized.

vpc
     VirtualPC compatible image format (VHD). Supported options:

     subformat
          Specifies which VHD subformat to use. Valid options are dynamic (default) and fixed.

VHDX
     Hyper-V compatible image format (VHDX). Supported options:

     subformat
          Specifies which VHDX subformat to use. Valid options are dynamic (default) and fixed.

     block_state_zero
          Force use of payload blocks of type 'ZERO'.

     block_size
          Block size; min 1 MB, max 256 MB.  0 means auto-calculate based on image size.

     log_size
          Log size; min 1 MB.

Read-only formats
.................

More disk image file formats are supported in a read-only mode.

bochs
     Bochs images of growing type.

cloop
     Linux Compressed Loop image, useful only to reuse directly compressed CD-ROM images present for example in the Knoppix CD-ROMs.

dmg
     Apple disk image.

parallels
     Parallels disk image format.

Using host drives
-----------------

In addition to disk image files, QEMU can directly access host devices. We describe here the usage for QEMU version >= 0.8.3.

Linux
.....

On Linux, you can directly use the host device filename instead of a disk image filename provided you have enough privileges to access it. For example, use /dev/cdrom to access to the CDROM or /dev/fd0 for the floppy.

CD
     You can specify a CDROM device even if no CDROM is loaded. QEMU has specific code to detect CDROM insertion or removal. CDROM ejection by the guest OS is supported. Currently only data CDs are supported.

Floppy
     You can specify a floppy device even if no floppy is loaded. Floppy removal is currently not detected accurately (if you change floppy without doing floppy access while the floppy is not loaded, the guest OS will think that the same floppy is loaded).

Hard disks
     Hard disks can be used. Normally you must specify the whole disk (/dev/hdb instead of /dev/hdb1) so that the guest OS can see it as a partitioned disk. WARNING: unless you know what you do, it is better to only make READ-ONLY accesses to the hard disk otherwise you may corrupt your host data (use the -snapshot command line option or modify the device permissions accordingly).

Windows
.......

CD
     The preferred syntax is the drive letter (e.g. d:). The alternate syntax \\.\d: is supported. /dev/cdrom is supported as an alias to the first CDROM drive.

     Currently there is no specific code to handle removable media, so it is better to use the change or eject monitor commands to change or eject media.

Hard disks
     Hard disks can be used with the syntax: \\.\PhysicalDriveN where N is the drive number (0 is the first hard disk).

     WARNING: unless you know what you do, it is better to only make READ-ONLY accesses to the hard disk otherwise you may corrupt your host data (use the -snapshot command line so that the modifications are written in a temporary file).

Mac OS X
........

/dev/cdrom is an alias to the first CDROM.

Currently there is no specific code to handle removable media, so it is better to use the change or eject monitor commands to change or eject media.

Virtual FAT disk images
-----------------------

QEMU can automatically create a virtual FAT disk image from a directory tree. In order to use it, just type:

     qemu-system-i386 linux.img -hdb fat:/my_directory

Then you access access to all the files in the /my_directory directory without having to copy them in a disk image or to export them via SAMBA or NFS. The default access is read-only.

Floppies can be emulated with the :floppy: option:

     qemu-system-i386 linux.img -fda fat:floppy:/my_directory

A read/write support is available for testing (beta stage) with the :rw: option:

     qemu-system-i386 linux.img -fda fat:floppy:rw:/my_directory

What you should never do:

  * use non-ASCII filenames ;

  * use "-snapshot" together with ":rw:" ;

  * expect it to work when loadvm'ing ;

  * write to the FAT directory on the host system while accessing it with the guest system.

NBD access
----------

QEMU can access directly to block device exported using the Network Block Device protocol.

     qemu-system-i386 linux.img -hdb nbd://my_nbd_server.mydomain.org:1024/

If the NBD server is located on the same host, you can use an unix socket instead of an inet socket:

     qemu-system-i386 linux.img -hdb nbd+unix://?socket=/tmp/my_socket

In this case, the block device must be exported using qemu-nbd:

     qemu-nbd --socket=/tmp/my_socket my_disk.qcow2

The use of qemu-nbd allows sharing of a disk between several guests:

     qemu-nbd --socket=/tmp/my_socket --share=2 my_disk.qcow2

and then you can use it with two guests:

     qemu-system-i386 linux1.img -hdb nbd+unix://?socket=/tmp/my_socket
     qemu-system-i386 linux2.img -hdb nbd+unix://?socket=/tmp/my_socket

If the nbd-server uses named exports (supported since NBD 2.9.18, or with QEMU's own embedded NBD server), you must specify an export name in the URI:

     qemu-system-i386 -cdrom nbd://localhost/debian-500-ppc-netinst
     qemu-system-i386 -cdrom nbd://localhost/openSUSE-11.1-ppc-netinst

The URI syntax for NBD is supported since QEMU 1.3.  An alternative syntax is also available.  Here are some example of the older syntax:

     qemu-system-i386 linux.img -hdb nbd:my_nbd_server.mydomain.org:1024
     qemu-system-i386 linux2.img -hdb nbd:unix:/tmp/my_socket
     qemu-system-i386 -cdrom nbd:localhost:10809:exportname=debian-500-ppc-netinst

Sheepdog disk images
--------------------

Sheepdog is a distributed storage system for QEMU.  It provides highly available block level storage volumes that can be attached to QEMU-based virtual machines.

You can create a Sheepdog disk image with the command:

     qemu-img create sheepdog:///IMAGE SIZE

where IMAGE is the Sheepdog image name and SIZE is its size.

To import the existing FILENAME to Sheepdog, you can use a convert command.

     qemu-img convert FILENAME sheepdog:///IMAGE

You can boot from the Sheepdog disk image with the command:

     qemu-system-i386 sheepdog:///IMAGE

You can also create a snapshot of the Sheepdog image like qcow2.

     qemu-img snapshot -c TAG sheepdog:///IMAGE

where TAG is a tag name of the newly created snapshot.

To boot from the Sheepdog snapshot, specify the tag name of the snapshot.

     qemu-system-i386 sheepdog:///IMAGE#TAG

You can create a cloned image from the existing snapshot.

     qemu-img create -b sheepdog:///BASE#TAG sheepdog:///IMAGE

where BASE is a image name of the source snapshot and TAG is its tag name.

You can use an unix socket instead of an inet socket:

     qemu-system-i386 sheepdog+unix:///IMAGE?socket=PATH

If the Sheepdog daemon doesn't run on the local host, you need to specify one of the Sheepdog servers to connect to.

     qemu-img create sheepdog://HOSTNAME:PORT/IMAGE SIZE
     qemu-system-i386 sheepdog://HOSTNAME:PORT/IMAGE

iSCSI LUNs
----------

iSCSI is a popular protocol used to access SCSI devices across a computer network.

There are two different ways iSCSI devices can be used by QEMU.

The first method is to mount the iSCSI LUN on the host, and make it appear as any other ordinary SCSI device on the host and then to access this device as a /dev/sd device from QEMU. How to do this differs between host OSes.

The second method involves using the iSCSI initiator that is built into QEMU. This provides a mechanism that works the same way regardless of which host OS you are running QEMU on. This section will describe this second method of using iSCSI together with QEMU.

In QEMU, iSCSI devices are described using special iSCSI URLs

     URL syntax:
     iscsi://[<username>[%<password>]@]<host>[:<port>]/<target-iqn-name>/<lun>

Username and password are optional and only used if your target is set up using CHAP authentication for access control. Alternatively the username and password can also be set via environment variables to have these not show up in the process list

     export LIBISCSI_CHAP_USERNAME=<username>
     export LIBISCSI_CHAP_PASSWORD=<password>
     iscsi://<host>/<target-iqn-name>/<lun>

Various session related parameters can be set via special options, either in a configuration file provided via '-readconfig' or directly on the command line.

If the initiator-name is not specified qemu will use a default name of 'iqn.2008-11.org.linux-kvm[:<name>'] where <name> is the name of the virtual machine.

     Setting a specific initiator name to use when logging in to the target
     -iscsi initiator-name=iqn.qemu.test:my-initiator

     Controlling which type of header digest to negotiate with the target
     -iscsi header-digest=CRC32C|CRC32C-NONE|NONE-CRC32C|NONE

These can also be set via a configuration file

     [iscsi]
       user = "CHAP username"
       password = "CHAP password"
       initiator-name = "iqn.qemu.test:my-initiator"
       # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
       header-digest = "CRC32C"

Setting the target name allows different options for different targets

     [iscsi "iqn.target.name"]
       user = "CHAP username"
       password = "CHAP password"
       initiator-name = "iqn.qemu.test:my-initiator"
       # header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
       header-digest = "CRC32C"

Howto use a configuration file to set iSCSI configuration options:

     cat >iscsi.conf <<EOF
     [iscsi]
       user = "me"
       password = "my password"
       initiator-name = "iqn.qemu.test:my-initiator"
       header-digest = "CRC32C"
     EOF

     qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
         -readconfig iscsi.conf

Howto set up a simple iSCSI target on loopback and accessing it via QEMU:

     This example shows how to set up an iSCSI target with one CDROM and one DISK
     using the Linux STGT software target. This target is available on Red Hat based
     systems as the package 'scsi-target-utils'.

     tgtd --iscsi portal=127.0.0.1:3260
     tgtadm --lld iscsi --op new --mode target --tid 1 -T iqn.qemu.test
     tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 \
         -b /IMAGES/disk.img --device-type=disk
     tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 \
         -b /IMAGES/cd.iso --device-type=cd
     tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL

     qemu-system-i386 -iscsi initiator-name=iqn.qemu.test:my-initiator \
         -boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
         -cdrom iscsi://127.0.0.1/iqn.qemu.test/2

GlusterFS disk images
---------------------

GlusterFS is an user space distributed file system.

You can boot from the GlusterFS disk image with the command:

     qemu-system-x86_64 -drive file=gluster[+TRANSPORT]://[SERVER[:PORT]]/VOLNAME/IMAGE[?socket=...]

GLUSTER is the protocol.

TRANSPORT specifies the transport type used to connect to gluster management daemon (glusterd). Valid transport types are tcp, unix and rdma. If a transport type isn't specified, then tcp type is assumed.

SERVER specifies the server where the volume file specification for the given volume resides. This can be either hostname, ipv4 address or ipv6 address. ipv6 address needs to be within square brackets [ ]. If transport type is unix, then SERVER field should not be specifed. Instead SOCKET field needs to be populated with the path to unix domain socket.

PORT is the port number on which glusterd is listening. This is optional and if not specified, QEMU will send 0 which will make gluster to use the default port. If the transport type is unix, then PORT should not be specified.

VOLNAME is the name of the gluster volume which contains the disk image.

IMAGE is the path to the actual disk image that resides on gluster volume.

You can create a GlusterFS disk image with the command:

     qemu-img create gluster://SERVER/VOLNAME/IMAGE SIZE

Examples

     qemu-system-x86_64 -drive file=gluster://1.2.3.4/testvol/a.img
     qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4/testvol/a.img
     qemu-system-x86_64 -drive file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img
     qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
     qemu-system-x86_64 -drive file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img
     qemu-system-x86_64 -drive file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img
     qemu-system-x86_64 -drive file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
     qemu-system-x86_64 -drive file=gluster+rdma://1.2.3.4:24007/testvol/a.img

Secure Shell (ssh) disk images
------------------------------

You can access disk images located on a remote ssh server by using the ssh protocol:

     qemu-system-x86_64 -drive file=ssh://[USER@]SERVER[:PORT]/PATH[?host_key_check=HOST_KEY_CHECK]

Alternative syntax using properties:

     qemu-system-x86_64 -drive file.driver=ssh[,file.user=USER],file.host=SERVER[,file.port=PORT],file.path=PATH[,file.host_key_check=HOST_KEY_CHECK]

SSH is the protocol.

USER is the remote user.  If not specified, then the local username is tried.

SERVER specifies the remote ssh server.  Any ssh server can be used, but it must implement the sftp-server protocol.  Most Unix/Linux systems should work without requiring any extra configuration.

PORT is the port number on which sshd is listening.  By default the standard ssh port (22) is used.

PATH is the path to the disk image.

The optional HOST_KEY_CHECK parameter controls how the remote host's key is checked.  The default is yes which means to use the local .ssh/known_hosts file.  Setting this to no turns off known-hosts checking.  Or you can check that the host key matches a specific fingerprint: host_key_check=md5:78:45:8e:14:57:4f:d5:45:83:0a:0e:f3:49:82:c9:c8 (sha1: can also be used as a prefix, but note that OpenSSH tools only use MD5 to print fingerprints).

Currently authentication must be done using ssh-agent.  Other authentication methods may be supported in future.

Note: Many ssh servers do not support an fsync-style operation. The ssh driver cannot guarantee that disk flush requests are obeyed, and this causes a risk of disk corruption if the remote server or network goes down during writes.  The driver will print a warning when fsync is not supported:

warning: ssh server ssh.example.com:22 does not support fsync

With sufficiently new versions of libssh2 and OpenSSH, fsync is supported.

Network emulation
=================

QEMU can simulate several network cards (PCI or ISA cards on the PC target) and can connect them to an arbitrary number of Virtual Local Area Networks (VLANs). Host TAP devices can be connected to any QEMU VLAN. VLAN can be connected between separate instances of QEMU to simulate large networks. For simpler usage, a non privileged user mode network stack can replace the TAP device to have a basic network connection.

VLANs
-----

QEMU simulates several VLANs. A VLAN can be symbolised as a virtual connection between several network devices. These devices can be for example QEMU virtual Ethernet cards or virtual Host ethernet devices (TAP devices).

Using TAP network interfaces
----------------------------

This is the standard way to connect QEMU to a real network. QEMU adds a virtual network device on your host (called tapN), and you can then configure it as if it was a real ethernet card.

Linux host
..........

As an example, you can download the linux-test-xxx.tar.gz archive and copy the script qemu-ifup in /etc and configure properly sudo so that the command ifconfig contained in qemu-ifup can be executed as root. You must verify that your host kernel supports the TAP network interfaces: the device /dev/net/tun must be present.

See sec_invocation to have examples of command lines using the TAP network interfaces.

Windows host
............

There is a virtual ethernet driver for Windows 2000/XP systems, called TAP-Win32. But it is not included in standard QEMU for Windows, so you will need to get it separately. It is part of OpenVPN package, so download OpenVPN from : http://openvpn.net/.

Using the user mode network stack
---------------------------------

By using the option -net user (default configuration if no -net option is specified), QEMU uses a completely user mode network stack (you don't need root privilege to use the virtual network). The virtual network configuration is the following:

              QEMU VLAN      <------>  Firewall/DHCP server <-----> Internet
                                |          (10.0.2.2)
                                |
                                ---->  DNS server (10.0.2.3)
                                |
                                ---->  SMB server (10.0.2.4)

The QEMU VM behaves as if it was behind a firewall which blocks all incoming connections. You can use a DHCP client to automatically configure the network in the QEMU VM. The DHCP server assign addresses to the hosts starting from 10.0.2.15.

In order to check that the user mode network is working, you can ping the address 10.0.2.2 and verify that you got an address in the range 10.0.2.x from the QEMU virtual DHCP server.

Note that ping is not supported reliably to the internet as it would require root privileges. It means you can only ping the local router (10.0.2.2).

When using the built-in TFTP server, the router is also the TFTP server.

When using the -redir option, TCP or UDP connections can be redirected from the host to the guest. It allows for example to redirect X11, telnet or SSH connections.

Connecting VLANs between QEMU instances
---------------------------------------

Using the -net socket option, it is possible to make VLANs that span several QEMU instances. See sec_invocation to have a basic example.

Other Devices
=============

Inter-VM Shared Memory device
-----------------------------

With KVM enabled on a Linux host, a shared memory device is available.  Guests map a POSIX shared memory region into the guest as a PCI device that enables zero-copy communication to the application level of the guests.  The basic syntax is:

     qemu-system-i386 -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>]

If desired, interrupts can be sent between guest VMs accessing the same shared memory region.  Interrupt support requires using a shared memory server and using a chardev socket to connect to it.  The code for the shared memory server is qemu.git/contrib/ivshmem-server.  An example syntax when using the shared memory server is:

     qemu-system-i386 -device ivshmem,size=<size in format accepted by -m>[,chardev=<id>]
                      [,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master]
     qemu-system-i386 -chardev socket,path=<path>,id=<id>

When using the server, the guest will be assigned a VM ID (>=0) that allows guests using the same server to communicate via interrupts.  Guests can read their VM ID from a device register (see example code).  Since receiving the shared memory region from the server is asynchronous, there is a (small) chance the guest may boot before the shared memory is attached.  To allow an application to ensure shared memory is attached, the VM ID register will return -1 (an invalid VM ID) until the memory is attached.  Once the shared memory is attached, the VM ID will return the guest's valid VM ID.  With these semantics, the guest application can check to ensure the shared memory is attached to the guest before proceeding.

The role argument can be set to either master or peer and will affect how the shared memory is migrated.  With role=master, the guest will copy the shared memory on migration to the destination host.  With role=peer, the guest will not be able to migrate with the device attached. With the peer case, the device should be detached and then reattached after migration using the PCI hotplug support.

Direct Linux Boot
=================

This section explains how to launch a Linux kernel inside QEMU without having to make a full bootable image. It is very useful for fast Linux kernel testing.

The syntax is:

     qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"

Use -kernel to provide the Linux kernel image and -append to give the kernel command line arguments. The -initrd option can be used to provide an INITRD image.

When using the direct Linux boot, a disk image for the first hard disk hda is required because its boot sector is used to launch the Linux kernel.

If you do not need graphical output, you can disable it and redirect the virtual serial port and the QEMU monitor to the console with the -nographic option. The typical command line is:

     qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
                      -append "root=/dev/hda console=ttyS0" -nographic

Use Ctrl-a c to switch between the serial console and the monitor (see pcsys_keys).

USB emulation
=============

QEMU emulates a PCI UHCI USB controller. You can virtually plug virtual USB devices or real host USB devices (experimental, works only on Linux hosts).  QEMU will automatically create and connect virtual USB hubs as necessary to connect multiple USB devices.

Connecting USB devices
----------------------

USB devices can be connected with the -usbdevice commandline option or the usb_add monitor command.  Available devices are:

mouse
     Virtual Mouse.  This will override the PS/2 mouse emulation when activated.

tablet
     Pointer device that uses absolute coordinates (like a touchscreen). This means QEMU is able to report the mouse position without having to grab the mouse.  Also overrides the PS/2 mouse emulation when activated.

disk:FILE
     Mass storage device based on FILE (see disk_images)

host:BUS.ADDR
     Pass through the host device identified by BUS.ADDR (Linux only)

host:VENDOR_ID:PRODUCT_ID
     Pass through the host device identified by VENDOR_ID:PRODUCT_ID (Linux only)

wacom-tablet
     Virtual Wacom PenPartner tablet.  This device is similar to the tablet above but it can be used with the tslib library because in addition to touch coordinates it reports touch pressure.

keyboard
     Standard USB keyboard.  Will override the PS/2 keyboard (if present).

serial:[vendorid=VENDOR_ID][,product_id=PRODUCT_ID]:DEV
     Serial converter. This emulates an FTDI FT232BM chip connected to host character device DEV. The available character devices are the same as for the -serial option. The vendorid and productid options can be used to override the default 0403:6001. For instance,

          usb_add serial:productid=FA00:tcp:192.168.0.2:4444

     will connect to tcp port 4444 of ip 192.168.0.2, and plug that to the virtual serial converter, faking a Matrix Orbital LCD Display (USB ID 0403:FA00).

braille
     Braille device.  This will use BrlAPI to display the braille output on a real or fake device.

net:OPTIONS
     Network adapter that supports CDC ethernet and RNDIS protocols.  OPTIONS specifies NIC options as with -net nic,OPTIONS (see description). For instance, user-mode networking can be used with

          qemu-system-i386 [...OPTIONS...] -net user,vlan=0 -usbdevice net:vlan=0

     Currently this cannot be used in machines that support PCI NICs.

bt[:HCI-TYPE]
     Bluetooth dongle whose type is specified in the same format as with the -bt hci option, see allowed HCI types.  If no type is given, the HCI logic corresponds to -bt hci,vlan=0. This USB device implements the USB Transport Layer of HCI.  Example usage:

          qemu-system-i386 [...OPTIONS...] -usbdevice bt:hci,vlan=3 -bt device:keyboard,vlan=3

Using host USB devices on a Linux host
--------------------------------------

WARNING: this is an experimental feature. QEMU will slow down when using it. USB devices requiring real time streaming (i.e. USB Video Cameras) are not supported yet.

 1. If you use an early Linux 2.4 kernel, verify that no Linux driver is actually using the USB device. A simple way to do that is simply to disable the corresponding kernel module by renaming it from mydriver.o to mydriver.o.disabled.

 2. Verify that /proc/bus/usb is working (most Linux distributions should enable it by default). You should see something like that:

          ls /proc/bus/usb
          001  devices  drivers

 3. 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:

          chown -R myuid /proc/bus/usb

 4. Launch QEMU and do in the monitor:

          info usbhost
            Device 1.2, speed 480 Mb/s
              Class 00: USB device 1234:5678, USB DISK

     You should see the list of the devices you can use (Never try to use hubs, it won't work).

 5. Add the device in QEMU by using:

          usb_add host:1234:5678

     Normally the guest OS should report that a new USB device is plugged. You can use the option -usbdevice to do the same.

 6. Now you can try to use the host USB device in QEMU.

When relaunching QEMU, you may have to unplug and plug again the USB device to make it work again (this is a bug).

VNC security
============

The VNC server capability provides access to the graphical console of the guest VM across the network. This has a number of security considerations depending on the deployment scenarios.

Without passwords
-----------------

The simplest VNC server setup does not include any form of authentication. For this setup it is recommended to restrict it to listen on a UNIX domain socket only. For example

     qemu-system-i386 [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc

This ensures that only users on local box with read/write access to that path can access the VNC server. To securely access the VNC server from a remote machine, a combination of netcat+ssh can be used to provide a secure tunnel.

With passwords
--------------

The VNC protocol has limited support for password based authentication. Since the protocol limits passwords to 8 characters it should not be considered to provide high security. The password can be fairly easily brute-forced by a client making repeat connections. For this reason, a VNC server using password authentication should be restricted to only listen on the loopback interface or UNIX domain sockets. Password authentication is not supported when operating in FIPS 140-2 compliance mode as it requires the use of the DES cipher. Password authentication is requested with the password option, and then once QEMU is running the password is set with the monitor. Until the monitor is used to set the password all clients will be rejected.

     qemu-system-i386 [...OPTIONS...] -vnc :1,password -monitor stdio
     (qemu) change vnc password
     Password: ********
     (qemu)

With x509 certificates
----------------------

The QEMU VNC server also implements the VeNCrypt extension allowing use of TLS for encryption of the session, and x509 certificates for authentication. The use of x509 certificates is strongly recommended, because TLS on its own is susceptible to man-in-the-middle attacks. Basic x509 certificate support provides a secure session, but no authentication. This allows any client to connect, and provides an encrypted session.

     qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio

In the above example /etc/pki/qemu should contain at least three files, ca-cert.pem, server-cert.pem and server-key.pem. Unprivileged users will want to use a private directory, for example $HOME/.pki/qemu. NB the server-key.pem file should be protected with file mode 0600 to only be readable by the user owning it.

With x509 certificates and client verification
----------------------------------------------

Certificates can also provide a means to authenticate the client connecting. The server will request that the client provide a certificate, which it will then validate against the CA certificate. This is a good choice if deploying in an environment with a private internal certificate authority.

     qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio

With x509 certificates, client verification and passwords
---------------------------------------------------------

Finally, the previous method can be combined with VNC password authentication to provide two layers of authentication for clients.

     qemu-system-i386 [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
     (qemu) change vnc password
     Password: ********
     (qemu)

With SASL authentication
------------------------

The SASL authentication method is a VNC extension, that provides an easily extendable, pluggable authentication method. This allows for integration with a wide range of authentication mechanisms, such as PAM, GSSAPI/Kerberos, LDAP, SQL databases, one-time keys and more. The strength of the authentication depends on the exact mechanism configured. If the chosen mechanism also provides a SSF layer, then it will encrypt the datastream as well.

Refer to the later docs on how to choose the exact SASL mechanism used for authentication, but assuming use of one supporting SSF, then QEMU can be launched with:

     qemu-system-i386 [...OPTIONS...] -vnc :1,sasl -monitor stdio

With x509 certificates and SASL authentication
----------------------------------------------

If the desired SASL authentication mechanism does not supported SSF layers, then it is strongly advised to run it in combination with TLS and x509 certificates. This provides securely encrypted data stream, avoiding risk of compromising of the security credentials. This can be enabled, by combining the 'sasl' option with the aforementioned TLS + x509 options:

     qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509,sasl -monitor stdio

Generating certificates for VNC
-------------------------------

The GNU TLS packages provides a command called certtool which can be used to generate certificates and keys in PEM format. At a minimum it is necessary to setup a certificate authority, and issue certificates to each server. If using certificates for authentication, then each client will also need to be issued a certificate. The recommendation is for the server to keep its certificates in either /etc/pki/qemu or for unprivileged users in $HOME/.pki/qemu.

Setup the Certificate Authority
...............................

This step only needs to be performed once per organization / organizational unit. First the CA needs a private key. This key must be kept VERY secret and secure. If this key is compromised the entire trust chain of the certificates issued with it is lost.

     # certtool --generate-privkey > ca-key.pem

A CA needs to have a public certificate. For simplicity it can be a self-signed certificate, or one issue by a commercial certificate issuing authority. To generate a self-signed certificate requires one core piece of information, the name of the organization.

     # cat > ca.info <<EOF
     cn = Name of your organization
     ca
     cert_signing_key
     EOF
     # certtool --generate-self-signed \
                --load-privkey ca-key.pem
                --template ca.info \
                --outfile ca-cert.pem

The ca-cert.pem file should be copied to all servers and clients wishing to utilize TLS support in the VNC server. The ca-key.pem must not be disclosed/copied at all.

Issuing server certificates
...........................

Each server (or host) needs to be issued with a key and certificate. When connecting the certificate is sent to the client which validates it against the CA certificate. The core piece of information for a server certificate is the hostname. This should be the fully qualified hostname that the client will connect with, since the client will typically also verify the hostname in the certificate. On the host holding the secure CA private key:

     # cat > server.info <<EOF
     organization = Name  of your organization
     cn = server.foo.example.com
     tls_www_server
     encryption_key
     signing_key
     EOF
     # certtool --generate-privkey > server-key.pem
     # certtool --generate-certificate \
                --load-ca-certificate ca-cert.pem \
                --load-ca-privkey ca-key.pem \
                --load-privkey server server-key.pem \
                --template server.info \
                --outfile server-cert.pem

The server-key.pem and server-cert.pem files should now be securely copied to the server for which they were generated. The server-key.pem is security sensitive and should be kept protected with file mode 0600 to prevent disclosure.

Issuing client certificates
...........................

If the QEMU VNC server is to use the x509verify option to validate client certificates as its authentication mechanism, each client also needs to be issued a certificate. The client certificate contains enough metadata to uniquely identify the client, typically organization, state, city, building, etc. On the host holding the secure CA private key:

     # cat > client.info <<EOF
     country = GB
     state = London
     locality = London
     organiazation = Name of your organization
     cn = client.foo.example.com
     tls_www_client
     encryption_key
     signing_key
     EOF
     # certtool --generate-privkey > client-key.pem
     # certtool --generate-certificate \
                --load-ca-certificate ca-cert.pem \
                --load-ca-privkey ca-key.pem \
                --load-privkey client-key.pem \
                --template client.info \
                --outfile client-cert.pem

The client-key.pem and client-cert.pem files should now be securely copied to the client for which they were generated.

Configuring SASL mechanisms
---------------------------

The following documentation assumes use of the Cyrus SASL implementation on a Linux host, but the principals should apply to any other SASL impl. When SASL is enabled, the mechanism configuration will be loaded from system default SASL service config /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, an environment variable SASL_CONF_PATH can be used to make it search alternate locations for the service config.

The default configuration might contain

     mech_list: digest-md5
     sasldb_path: /etc/qemu/passwd.db

This says to use the 'Digest MD5' mechanism, which is similar to the HTTP Digest-MD5 mechanism. The list of valid usernames & passwords is maintained in the /etc/qemu/passwd.db file, and can be updated using the saslpasswd2 command. While this mechanism is easy to configure and use, it is not considered secure by modern standards, so only suitable for developers / ad-hoc testing.

A more serious deployment might use Kerberos, which is done with the 'gssapi' mechanism

     mech_list: gssapi
     keytab: /etc/qemu/krb5.tab

For this to work the administrator of your KDC must generate a Kerberos principal for the server, with a name of  'qemu/somehost.example.com@EXAMPLE.COM' replacing 'somehost.example.com' with the fully qualified host name of the machine running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.

Other configurations will be left as an exercise for the reader. It should be noted that only Digest-MD5 and GSSAPI provides a SSF layer for data encryption. For all other mechanisms, VNC should always be configured to use TLS and x509 certificates to protect security credentials from snooping.

GDB usage
=========

QEMU has a primitive support to work with gdb, so that you can do 'Ctrl-C' while the virtual machine is running and inspect its state.

In order to use gdb, launch QEMU with the '-s' option. It will wait for a gdb connection:

     qemu-system-i386 -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
                         -append "root=/dev/hda"
     Connected to host network interface: tun0
     Waiting gdb connection on port 1234

Then launch gdb on the 'vmlinux' executable:

     > gdb vmlinux

In gdb, connect to QEMU:

     (gdb) target remote localhost:1234

Then you can use gdb normally. For example, type 'c' to launch the kernel:

     (gdb) c

Here are some useful tips in order to use gdb on system code:

 1. Use info reg to display all the CPU registers.

 2. Use x/10i $eip to display the code at the PC position.

 3. Use set architecture i8086 to dump 16 bit code. Then use x/10i $cs*16+$eip to dump the code at the PC position.

Advanced debugging options:

The default single stepping behavior is step with the IRQs and timer service routines off.  It is set this way because when gdb executes a single step it expects to advance beyond the current instruction.  With the IRQs and and timer service routines on, a single step might jump into the one of the interrupt or exception vectors instead of executing the current instruction. This means you may hit the same breakpoint a number of times before executing the instruction gdb wants to have executed.  Because there are rare circumstances where you want to single step into an interrupt vector the behavior can be controlled from GDB.  There are three commands you can query and set the single step behavior:

maintenance packet qqemu.sstepbits

     This will display the MASK bits used to control the single stepping IE:

          (gdb) maintenance packet qqemu.sstepbits
          sending: "qqemu.sstepbits"
          received: "ENABLE=1,NOIRQ=2,NOTIMER=4"

maintenance packet qqemu.sstep

     This will display the current value of the mask used when single stepping IE:

          (gdb) maintenance packet qqemu.sstep
          sending: "qqemu.sstep"
          received: "0x7"

maintenance packet Qqemu.sstep=HEX_VALUE

     This will change the single step mask, so if wanted to enable IRQs on the single step, but not timers, you would use:

          (gdb) maintenance packet Qqemu.sstep=0x5
          sending: "qemu.sstep=0x5"
          received: "OK"

Target OS specific information
==============================

Linux
-----

To have access to SVGA graphic modes under X11, use the vesa or the cirrus X11 driver. For optimal performances, use 16 bit color depth in the guest and the host OS.

When using a 2.6 guest Linux kernel, you should add the option clock=pit on the kernel command line because the 2.6 Linux kernels make very strict real time clock checks by default that QEMU cannot simulate exactly.

When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is not activated because QEMU is slower with this patch. The QEMU Accelerator Module is also much slower in this case. Earlier Fedora Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this patch by default. Newer kernels don't have it.

Windows
-------

If you have a slow host, using Windows 95 is better as it gives the best speed. Windows 2000 is also a good choice.

SVGA graphic modes support
..........................

QEMU emulates a Cirrus Logic GD5446 Video card. All Windows versions starting from Windows 95 should recognize and use this graphic card. For optimal performances, use 16 bit color depth in the guest and the host OS.

If you are using Windows XP as guest OS and if you want to use high resolution modes which the Cirrus Logic BIOS does not support (i.e. >= 1280x1024x16), then you should use the VESA VBE virtual graphic card (option -std-vga).

CPU usage reduction
...................

Windows 9x does not correctly use the CPU HLT instruction. The result is that it takes host CPU cycles even when idle. You can install the utility from http://www.user.cityline.ru/~maxamn/amnhltm.zip to solve this problem. Note that no such tool is needed for NT, 2000 or XP.

Windows 2000 disk full problem
..............................

Windows 2000 has a bug which gives a disk full problem during its installation. When installing it, use the -win2k-hack QEMU option to enable a specific workaround. After Windows 2000 is installed, you no longer need this option (this option slows down the IDE transfers).

Windows 2000 shutdown
.....................

Windows 2000 cannot automatically shutdown in QEMU although Windows 98 can. It comes from the fact that Windows 2000 does not automatically use the APM driver provided by the BIOS.

In order to correct that, do the following (thanks to Struan Bartlett): go to the Control Panel => Add/Remove Hardware & Next => Add/Troubleshoot a device => Add a new device & Next => No, select the hardware from a list & Next => NT Apm/Legacy Support & Next => Next (again) a few times. Now the driver is installed and Windows 2000 now correctly instructs QEMU to shutdown at the appropriate moment.

Share a directory between Unix and Windows
..........................................

See sec_invocation about the help of the option -smb.

Windows XP security problem
...........................

Some releases of Windows XP install correctly but give a security error when booting:

     A problem is preventing Windows from accurately checking the
     license for this computer. Error code: 0x800703e6.

The workaround is to install a service pack for XP after a boot in safe mode. Then reboot, and the problem should go away. Since there is no network while in safe mode, its recommended to download the full installation of SP1 or SP2 and transfer that via an ISO or using the vvfat block device ("-hdb fat:directory_which_holds_the_SP").

MS-DOS and FreeDOS
------------------

CPU usage reduction
...................

DOS does not correctly use the CPU HLT instruction. The result is that it takes host CPU cycles even when idle. You can install the utility from http://www.vmware.com/software/dosidle210.zip to solve this problem.

QEMU System emulator for non PC targets
***************************************

QEMU is a generic emulator and it emulates many non PC machines. Most of the options are similar to the PC emulator. The differences are mentioned in the following sections.

PowerPC System emulator
=======================

Use the executable qemu-system-ppc to simulate a complete PREP or PowerMac PowerPC system.

QEMU emulates the following PowerMac peripherals:

  - UniNorth or Grackle PCI Bridge

  - PCI VGA compatible card with VESA Bochs Extensions

  - 2 PMAC IDE interfaces with hard disk and CD-ROM support

  - NE2000 PCI adapters

  - Non Volatile RAM

  - VIA-CUDA with ADB keyboard and mouse.

QEMU emulates the following PREP peripherals:

  - PCI Bridge

  - PCI VGA compatible card with VESA Bochs Extensions

  - 2 IDE interfaces with hard disk and CD-ROM support

  - Floppy disk

  - NE2000 network adapters

  - Serial port

  - PREP Non Volatile RAM

  - PC compatible keyboard and mouse.

QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at http://perso.magic.fr/l_indien/OpenHackWare/index.htm.

Since version 0.9.1, QEMU uses OpenBIOS http://www.openbios.org/ for the g3beige and mac99 PowerMac machines. OpenBIOS is a free (GPL v2) portable firmware implementation. The goal is to implement a 100% IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.

The following options are specific to the PowerPC emulation:

-g WxH[xDEPTH]

     Set the initial VGA graphic mode. The default is 800x600x32.

-prom-env STRING

     Set OpenBIOS variables in NVRAM, for example:

          qemu-system-ppc -prom-env 'auto-boot?=false' \
           -prom-env 'boot-device=hd:2,\yaboot' \
           -prom-env 'boot-args=conf=hd:2,\yaboot.conf'

     These variables are not used by Open Hack'Ware.

More information is available at http://perso.magic.fr/l_indien/qemu-ppc/.

Sparc32 System emulator
=======================

Use the executable qemu-system-sparc to simulate the following Sun4m architecture machines:

  - SPARCstation 4

  - SPARCstation 5

  - SPARCstation 10

  - SPARCstation 20

  - SPARCserver 600MP

  - SPARCstation LX

  - SPARCstation Voyager

  - SPARCclassic

  - SPARCbook

The emulation is somewhat complete. SMP up to 16 CPUs is supported, but Linux limits the number of usable CPUs to 4.

QEMU emulates the following sun4m peripherals:

  - IOMMU

  - TCX or cgthree Frame buffer

  - Lance (Am7990) Ethernet

  - Non Volatile RAM M48T02/M48T08

  - Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard and power/reset logic

  - ESP SCSI controller with hard disk and CD-ROM support

  - Floppy drive (not on SS-600MP)

  - CS4231 sound device (only on SS-5, not working yet)

The number of peripherals is fixed in the architecture.  Maximum memory size depends on the machine type, for SS-5 it is 256MB and for others 2047MB.

Since version 0.8.2, QEMU uses OpenBIOS http://www.openbios.org/. OpenBIOS is a free (GPL v2) portable firmware implementation. The goal is to implement a 100% IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.

A sample Linux 2.6 series kernel and ram disk image are available on the QEMU web site. There are still issues with NetBSD and OpenBSD, but some kernel versions work. Please note that currently older Solaris kernels don't work probably due to interface issues between OpenBIOS and Solaris.

The following options are specific to the Sparc32 emulation:

-g WxHx[xDEPTH]

     Set the initial graphics mode. For TCX, the default is 1024x768x8 with the option of 1024x768x24. For cgthree, the default is 1024x768x8 with the option of 1152x900x8 for people who wish to use OBP.

-prom-env STRING

     Set OpenBIOS variables in NVRAM, for example:

          qemu-system-sparc -prom-env 'auto-boot?=false' \
           -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'

-M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic] [|SPARCbook]

     Set the emulated machine type. Default is SS-5.

Sparc64 System emulator
=======================

Use the executable qemu-system-sparc64 to simulate a Sun4u (UltraSPARC PC-like machine), Sun4v (T1 PC-like machine), or generic Niagara (T1) machine. The emulator is not usable for anything yet, but it can launch some kernels.

QEMU emulates the following peripherals:

  - UltraSparc IIi APB PCI Bridge

  - PCI VGA compatible card with VESA Bochs Extensions

  - PS/2 mouse and keyboard

  - Non Volatile RAM M48T59

  - PC-compatible serial ports

  - 2 PCI IDE interfaces with hard disk and CD-ROM support

  - Floppy disk

The following options are specific to the Sparc64 emulation:

-prom-env STRING

     Set OpenBIOS variables in NVRAM, for example:

          qemu-system-sparc64 -prom-env 'auto-boot?=false'

-M [sun4u|sun4v|Niagara]

     Set the emulated machine type. The default is sun4u.

MIPS System emulator
====================

Four executables cover simulation of 32 and 64-bit MIPS systems in both endian options, qemu-system-mips, qemu-system-mipsel qemu-system-mips64 and qemu-system-mips64el. Five different machine types are emulated:

  - A generic ISA PC-like machine "mips"

  - The MIPS Malta prototype board "malta"

  - An ACER Pica "pica61". This machine needs the 64-bit emulator.

  - MIPS emulator pseudo board "mipssim"

  - A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator.

The generic emulation is supported by Debian 'Etch' and is able to install Debian into a virtual disk image. The following devices are emulated:

  - A range of MIPS CPUs, default is the 24Kf

  - PC style serial port

  - PC style IDE disk

  - NE2000 network card

The Malta emulation supports the following devices:

  - Core board with MIPS 24Kf CPU and Galileo system controller

  - PIIX4 PCI/USB/SMbus controller

  - The Multi-I/O chip's serial device

  - PCI network cards (PCnet32 and others)

  - Malta FPGA serial device

  - Cirrus (default) or any other PCI VGA graphics card

The ACER Pica emulation supports:

  - MIPS R4000 CPU

  - PC-style IRQ and DMA controllers

  - PC Keyboard

  - IDE controller

The mipssim pseudo board emulation provides an environment similar to what the proprietary MIPS emulator uses for running Linux. It supports:

  - A range of MIPS CPUs, default is the 24Kf

  - PC style serial port

  - MIPSnet network emulation

The MIPS Magnum R4000 emulation supports:

  - MIPS R4000 CPU

  - PC-style IRQ controller

  - PC Keyboard

  - SCSI controller

  - G364 framebuffer

ARM System emulator
===================

Use the executable qemu-system-arm to simulate a ARM machine. The ARM Integrator/CP board is emulated with the following devices:

  - ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU

  - Two PL011 UARTs

  - SMC 91c111 Ethernet adapter

  - PL110 LCD controller

  - PL050 KMI with PS/2 keyboard and mouse.

  - PL181 MultiMedia Card Interface with SD card.

The ARM Versatile baseboard is emulated with the following devices:

  - ARM926E, ARM1136 or Cortex-A8 CPU

  - PL190 Vectored Interrupt Controller

  - Four PL011 UARTs

  - SMC 91c111 Ethernet adapter

  - PL110 LCD controller

  - PL050 KMI with PS/2 keyboard and mouse.

  - PCI host bridge.  Note the emulated PCI bridge only provides access to PCI memory space.  It does not provide access to PCI IO space. This means some devices (eg. ne2k_pci NIC) are not usable, and others (eg. rtl8139 NIC) are only usable when the guest drivers use the memory mapped control registers.

  - PCI OHCI USB controller.

  - LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.

  - PL181 MultiMedia Card Interface with SD card.

Several variants of the ARM RealView baseboard are emulated, including the EB, PB-A8 and PBX-A9.  Due to interactions with the bootloader, only certain Linux kernel configurations work out of the box on these boards.

Kernels for the PB-A8 board should have CONFIG_REALVIEW_HIGH_PHYS_OFFSET enabled in the kernel, and expect 512M RAM.  Kernels for The PBX-A9 board should have CONFIG_SPARSEMEM enabled, CONFIG_REALVIEW_HIGH_PHYS_OFFSET disabled and expect 1024M RAM.

The following devices are emulated:

  - ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU

  - ARM AMBA Generic/Distributed Interrupt Controller

  - Four PL011 UARTs

  - SMC 91c111 or SMSC LAN9118 Ethernet adapter

  - PL110 LCD controller

  - PL050 KMI with PS/2 keyboard and mouse

  - PCI host bridge

  - PCI OHCI USB controller

  - LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices

  - PL181 MultiMedia Card Interface with SD card.

The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi" and "Terrier") emulation includes the following peripherals:

  - Intel PXA270 System-on-chip (ARM V5TE core)

  - NAND Flash memory

  - IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"

  - On-chip OHCI USB controller

  - On-chip LCD controller

  - On-chip Real Time Clock

  - TI ADS7846 touchscreen controller on SSP bus

  - Maxim MAX1111 analog-digital converter on I^2C bus

  - GPIO-connected keyboard controller and LEDs

  - Secure Digital card connected to PXA MMC/SD host

  - Three on-chip UARTs

  - WM8750 audio CODEC on I^2C and I^2S busses

The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the following elements:

  - Texas Instruments OMAP310 System-on-chip (ARM 925T core)

  - ROM and RAM memories (ROM firmware image can be loaded with -option-rom)

  - On-chip LCD controller

  - On-chip Real Time Clock

  - TI TSC2102i touchscreen controller / analog-digital converter / Audio CODEC, connected through MicroWire and I^2S busses

  - GPIO-connected matrix keypad

  - Secure Digital card connected to OMAP MMC/SD host

  - Three on-chip UARTs

Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48) emulation supports the following elements:

  - Texas Instruments OMAP2420 System-on-chip (ARM 1136 core)

  - RAM and non-volatile OneNAND Flash memories

  - Display connected to EPSON remote framebuffer chip and OMAP on-chip display controller and a LS041y3 MIPI DBI-C controller

  - TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers driven through SPI bus

  - National Semiconductor LM8323-controlled qwerty keyboard driven through I^2C bus

  - Secure Digital card connected to OMAP MMC/SD host

  - Three OMAP on-chip UARTs and on-chip STI debugging console

  - A Bluetooth(R) transceiver and HCI connected to an UART

  - Mentor Graphics "Inventra" dual-role USB controller embedded in a TI TUSB6010 chip - only USB host mode is supported

  - TI TMP105 temperature sensor driven through I^2C bus

  - TI TWL92230C power management companion with an RTC on I^2C bus

  - Nokia RETU and TAHVO multi-purpose chips with an RTC, connected through CBUS

The Luminary Micro Stellaris LM3S811EVB emulation includes the following devices:

  - Cortex-M3 CPU core.

  - 64k Flash and 8k SRAM.

  - Timers, UARTs, ADC and I^2C interface.

  - OSRAM Pictiva 96x16 OLED with SSD0303 controller on I^2C bus.

The Luminary Micro Stellaris LM3S6965EVB emulation includes the following devices:

  - Cortex-M3 CPU core.

  - 256k Flash and 64k SRAM.

  - Timers, UARTs, ADC, I^2C and SSI interfaces.

  - OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI.

The Freecom MusicPal internet radio emulation includes the following elements:

  - Marvell MV88W8618 ARM core.

  - 32 MB RAM, 256 KB SRAM, 8 MB flash.

  - Up to 2 16550 UARTs

  - MV88W8xx8 Ethernet controller

  - MV88W8618 audio controller, WM8750 CODEC and mixer

  - 128×64 display with brightness control

  - 2 buttons, 2 navigation wheels with button function

The Siemens SX1 models v1 and v2 (default) basic emulation. The emulation includes the following elements:

  - Texas Instruments OMAP310 System-on-chip (ARM 925T core)

  - ROM and RAM memories (ROM firmware image can be loaded with -pflash) V1 1 Flash of 16MB and 1 Flash of 8MB V2 1 Flash of 32MB

  - On-chip LCD controller

  - On-chip Real Time Clock

  - Secure Digital card connected to OMAP MMC/SD host

  - Three on-chip UARTs

A Linux 2.6 test image is available on the QEMU web site. More information is available in the QEMU mailing-list archive.

The following options are specific to the ARM emulation:

-semihosting
     Enable semihosting syscall emulation.

     On ARM this implements the "Angel" interface.

     Note that this allows guest direct access to the host filesystem, so should only be used with trusted guest OS.

ColdFire System emulator
========================

Use the executable qemu-system-m68k to simulate a ColdFire machine. The emulator is able to boot a uClinux kernel.

The M5208EVB emulation includes the following devices:

  - MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).

  - Three Two on-chip UARTs.

  - Fast Ethernet Controller (FEC)

The AN5206 emulation includes the following devices:

  - MCF5206 ColdFire V2 Microprocessor.

  - Two on-chip UARTs.

The following options are specific to the ColdFire emulation:

-semihosting
     Enable semihosting syscall emulation.

     On M68K this implements the "ColdFire GDB" interface used by libgloss.

     Note that this allows guest direct access to the host filesystem, so should only be used with trusted guest OS.

Cris System emulator
====================

TODO

Microblaze System emulator
==========================

TODO

SH4 System emulator
===================

TODO

Xtensa System emulator
======================

Two executables cover simulation of both Xtensa endian options, qemu-system-xtensa and qemu-system-xtensaeb. Two different machine types are emulated:

  - Xtensa emulator pseudo board "sim"

  - Avnet LX60/LX110/LX200 board

The sim pseudo board emulation provides an environment similar to one provided by the proprietary Tensilica ISS. It supports:

  - A range of Xtensa CPUs, default is the DC232B

  - Console and filesystem access via semihosting calls

The Avnet LX60/LX110/LX200 emulation supports:

  - A range of Xtensa CPUs, default is the DC232B

  - 16550 UART

  - OpenCores 10/100 Mbps Ethernet MAC

The following options are specific to the Xtensa emulation:

-semihosting
     Enable semihosting syscall emulation.

     Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select. Tensilica baremetal libc for ISS and linux platform "sim" use this interface.

     Note that this allows guest direct access to the host filesystem, so should only be used with trusted guest OS.

QEMU User space emulator
************************

Supported Operating Systems
===========================

The following OS are supported in user space emulation:

  - Linux (referred as qemu-linux-user)

  - BSD (referred as qemu-bsd-user)

Linux User space emulator
=========================

Quick Start
-----------

In order to launch a Linux process, QEMU needs the process executable itself and all the target (x86) dynamic libraries used by it.

  * On x86, you can just try to launch any process by using the native libraries:

          qemu-i386 -L / /bin/ls

     -L / tells that the x86 dynamic linker must be searched with a / prefix.

  * Since QEMU is also a linux process, you can launch QEMU with QEMU (NOTE: you can only do that if you compiled QEMU from the sources):

          qemu-i386 -L / qemu-i386 -L / /bin/ls

  * On non x86 CPUs, you need first to download at least an x86 glibc (qemu-runtime-i386-XXX-.tar.gz on the QEMU web page). Ensure that LD_LIBRARY_PATH is not set:

          unset LD_LIBRARY_PATH

     Then you can launch the precompiled ls x86 executable:

          qemu-i386 tests/i386/ls

     You can look at scripts/qemu-binfmt-conf.sh so that QEMU is automatically launched by the Linux kernel when you try to launch x86 executables. It requires the binfmt_misc module in the Linux kernel.

  * The x86 version of QEMU is also included. You can try weird things such as:

          qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
                    /usr/local/qemu-i386/bin/ls-i386

Wine launch
-----------

  * Ensure that you have a working QEMU with the x86 glibc distribution (see previous section). In order to verify it, you must be able to do:

          qemu-i386 /usr/local/qemu-i386/bin/ls-i386

  * Download the binary x86 Wine install (qemu-XXX-i386-wine.tar.gz on the QEMU web page).

  * Configure Wine on your account. Look at the provided script /usr/local/qemu-i386/bin/wine-conf.sh. Your previous ${HOME}/.wine directory is saved to ${HOME}/.wine.org.

  * Then you can try the example putty.exe:

          qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
                    /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe

Command line options
--------------------

     usage: qemu-i386 [-h] [-d] [-L path] [-s size] [-cpu model] [-g port] [-B offset] [-R size] program [arguments...]

-h
     Print the help

-L path
     Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)

-s size
     Set the x86 stack size in bytes (default=524288)

-cpu model
     Select CPU model (-cpu help for list and additional feature selection)

-E VAR=VALUE
     Set environment VAR to VALUE.

-U VAR
     Remove VAR from the environment.

-B offset
     Offset guest address by the specified number of bytes.  This is useful when the address region required by guest applications is reserved on the host. This option is currently only supported on some hosts.

-R size
     Pre-allocate a guest virtual address space of the given size (in bytes). "G", "M", and "k" suffixes may be used when specifying the size.

Debug options:

-d item1,...
     Activate logging of the specified items (use '-d help' for a list of log items)

-p pagesize
     Act as if the host page size was 'pagesize' bytes

-g port
     Wait gdb connection to port

-singlestep
     Run the emulation in single step mode.

Environment variables:

QEMU_STRACE
     Print system calls and arguments similar to the 'strace' program (NOTE: the actual 'strace' program will not work because the user space emulator hasn't implemented ptrace).  At the moment this is incomplete.  All system calls that don't have a specific argument format are printed with information for six arguments.  Many flag-style arguments don't have decoders and will show up as numbers.

Other binaries
--------------

qemu-alpha TODO.

qemu-armeb TODO.

qemu-arm is also capable of running ARM "Angel" semihosted ELF binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB configurations), and arm-uclinux bFLT format binaries.

qemu-m68k is capable of running semihosted binaries using the BDM (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and coldfire uClinux bFLT format binaries.

The binary format is detected automatically.

qemu-cris TODO.

qemu-i386 TODO. qemu-x86_64 TODO.

qemu-microblaze TODO.

qemu-mips TODO. qemu-mipsel TODO.

qemu-ppc64abi32 TODO. qemu-ppc64 TODO. qemu-ppc TODO.

qemu-sh4eb TODO. qemu-sh4 TODO.

qemu-sparc can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).

qemu-sparc32plus can execute Sparc32 and SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).

qemu-sparc64 can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).

BSD User space emulator
=======================

BSD Status
----------

  - target Sparc64 on Sparc64: Some trivial programs work.

Quick Start
-----------

In order to launch a BSD process, QEMU needs the process executable itself and all the target dynamic libraries used by it.

  * On Sparc64, you can just try to launch any process by using the native libraries:

          qemu-sparc64 /bin/ls

Command line options
--------------------

     usage: qemu-sparc64 [-h] [-d] [-L path] [-s size] [-bsd type] program [arguments...]

-h
     Print the help

-L path
     Set the library root path (default=/)

-s size
     Set the stack size in bytes (default=524288)

-ignore-environment
     Start with an empty environment. Without this option, the initial environment is a copy of the caller's environment.

-E VAR=VALUE
     Set environment VAR to VALUE.

-U VAR
     Remove VAR from the environment.

-bsd type
     Set the type of the emulated BSD Operating system. Valid values are FreeBSD, NetBSD and OpenBSD (default).

Debug options:

-d item1,...
     Activate logging of the specified items (use '-d help' for a list of log items)

-p pagesize
     Act as if the host page size was 'pagesize' bytes

-singlestep
     Run the emulation in single step mode.

Compilation from the sources
****************************

Linux/Unix
==========

Compilation
-----------

First you must decompress the sources:

     cd /tmp
     tar zxvf qemu-x.y.z.tar.gz
     cd qemu-x.y.z

Then you configure QEMU and build it (usually no options are needed):

     ./configure
     make

Then type as root user:

     make install

to install QEMU in /usr/local.

Windows
=======

  * Install the current versions of MSYS and MinGW from http://www.mingw.org/. You can find detailed installation instructions in the download section and the FAQ.

  * Download the MinGW development library of SDL 1.2.x (SDL-devel-1.2.x-mingw32.tar.gz) from http://www.libsdl.org. Unpack it in a temporary place and edit the sdl-config script so that it gives the correct SDL directory when invoked.

  * Install the MinGW version of zlib and make sure zlib.h and libz.dll.a are in MinGW's default header and linker search paths.

  * Extract the current version of QEMU.

  * Start the MSYS shell (file msys.bat).

  * Change to the QEMU directory. Launch ./configure and make.  If you have problems using SDL, verify that sdl-config can be launched from the MSYS command line.

  * You can install QEMU in Program Files/QEMU by typing make install. Don't forget to copy SDL.dll in Program Files/QEMU.

Cross compilation for Windows with Linux
========================================

  * Install the MinGW cross compilation tools available at http://www.mingw.org/.

  * Download the MinGW development library of SDL 1.2.x (SDL-devel-1.2.x-mingw32.tar.gz) from http://www.libsdl.org. Unpack it in a temporary place and edit the sdl-config script so that it gives the correct SDL directory when invoked.  Set up the PATH environment variable so that sdl-config can be launched by the QEMU configuration script.

  * Install the MinGW version of zlib and make sure zlib.h and libz.dll.a are in MinGW's default header and linker search paths.

  * Configure QEMU for Windows cross compilation:

          PATH=/usr/i686-pc-mingw32/sys-root/mingw/bin:$PATH ./configure --cross-prefix='i686-pc-mingw32-'

     The example assumes sdl-config is installed under /usr/i686-pc-mingw32/sys-root/mingw/bin and MinGW cross compilation tools have names like i686-pc-mingw32-gcc and i686-pc-mingw32-strip. We set the PATH environment variable to ensure the MinGW version of sdl-config is used and use --cross-prefix to specify the name of the cross compiler. You can also use --prefix to set the Win32 install path which defaults to c:/Program Files/QEMU.

     Under Fedora Linux, you can run:

          yum -y install mingw32-gcc mingw32-SDL mingw32-zlib

     to get a suitable cross compilation environment.

  * You can install QEMU in the installation directory by typing make install. Don't forget to copy SDL.dll and zlib1.dll into the installation directory.

Wine can be used to launch the resulting qemu-system-i386.exe and all other qemu-system-TARGET.exe compiled for Win32.

Mac OS X
========

The Mac OS X patches are not fully merged in QEMU, so you should look at the QEMU mailing list archive to have all the necessary information.

Make targets
============

make

make all
     Make everything which is typically needed.

install
     TODO

install-doc
     TODO

make clean
     Remove most files which were built during make.

make distclean
     Remove everything which was built during make.

make dvi

make html

make info

make pdf
     Create documentation in dvi, html, info or pdf format.

make cscope
     TODO

make defconfig
     (Re-)create some build configuration files. User made changes will be overwritten.

tar

tarbin
     TODO

License
*******

QEMU is a trademark of Fabrice Bellard.

QEMU is released under the GNU General Public License (TODO: add link). Parts of QEMU have specific licenses, see file LICENSE.

TODO (refer to file LICENSE, include it, include the GPL?)

Index
*****

Concept Index
=============

This is the main index. Should we combine all keywords in one index? TODO

Function Index
==============

This index could be used for command line options and monitor functions.

Keystroke Index
===============

This is a list of all keystrokes which have a special function in system emulation.

Data Type Index
===============

This index could be used for qdev device names and options.