\input texinfo @c -*- texinfo -*- @c %**start of header @setfilename qemu-doc.info @include version.texi @documentlanguage en @documentencoding UTF-8 @settitle QEMU version @value{VERSION} User Documentation @exampleindent 0 @paragraphindent 0 @c %**end of header @ifinfo @direntry * QEMU: (qemu-doc). The QEMU Emulator User Documentation. @end direntry @end ifinfo @iftex @titlepage @sp 7 @center @titlefont{QEMU version @value{VERSION}} @sp 1 @center @titlefont{User Documentation} @sp 3 @end titlepage @end iftex @ifnottex @node Top @top @menu * Introduction:: * QEMU PC System emulator:: * QEMU System emulator for non PC targets:: * QEMU Guest Agent:: * QEMU User space emulator:: * Implementation notes:: * Deprecated features:: * License:: * Index:: @end menu @end ifnottex @contents @node Introduction @chapter Introduction @menu * intro_features:: Features @end menu @node intro_features @section Features QEMU is a FAST! processor emulator using dynamic translation to achieve good emulation speed. @cindex operating modes QEMU has two operating modes: @itemize @cindex system emulation @item 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. @cindex user mode emulation @item 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 (@url{http://www.winehq.org}) or to ease cross-compilation and cross-debugging. @end itemize QEMU has the following features: @itemize @item QEMU can run without a host kernel driver and yet gives acceptable performance. It uses dynamic translation to native code for reasonable speed, with support for self-modifying code and precise exceptions. @item It is portable to several operating systems (GNU/Linux, *BSD, Mac OS X, Windows) and architectures. @item It performs accurate software emulation of the FPU. @end itemize QEMU user mode emulation has the following features: @itemize @item Generic Linux system call converter, including most ioctls. @item clone() emulation using native CPU clone() to use Linux scheduler for threads. @item Accurate signal handling by remapping host signals to target signals. @end itemize QEMU full system emulation has the following features: @itemize @item QEMU uses a full software MMU for maximum portability. @item QEMU can optionally use an in-kernel accelerator, like kvm. The accelerators execute most of the guest code natively, while continuing to emulate the rest of the machine. @item Various hardware devices can be emulated and in some cases, host devices (e.g. serial and parallel ports, USB, drives) can be used transparently by the guest Operating System. Host device passthrough can be used for talking to external physical peripherals (e.g. a webcam, modem or tape drive). @item Symmetric multiprocessing (SMP) support. Currently, an in-kernel accelerator is required to use more than one host CPU for emulation. @end itemize @node QEMU PC System emulator @chapter QEMU PC System emulator @cindex system emulation (PC) @menu * pcsys_introduction:: Introduction * pcsys_quickstart:: Quick Start * sec_invocation:: Invocation * pcsys_keys:: Keys in the graphical frontends * mux_keys:: Keys in the character backend multiplexer * pcsys_monitor:: QEMU Monitor * disk_images:: Disk Images * pcsys_network:: Network emulation * pcsys_other_devs:: Other Devices * direct_linux_boot:: Direct Linux Boot * pcsys_usb:: USB emulation * vnc_security:: VNC security * gdb_usage:: GDB usage * pcsys_os_specific:: Target OS specific information @end menu @node pcsys_introduction @section Introduction @c man begin DESCRIPTION The QEMU PC System emulator simulates the following peripherals: @itemize @minus @item i440FX host PCI bridge and PIIX3 PCI to ISA bridge @item Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA extensions (hardware level, including all non standard modes). @item PS/2 mouse and keyboard @item 2 PCI IDE interfaces with hard disk and CD-ROM support @item Floppy disk @item PCI and ISA network adapters @item Serial ports @item IPMI BMC, either and internal or external one @item Creative SoundBlaster 16 sound card @item ENSONIQ AudioPCI ES1370 sound card @item Intel 82801AA AC97 Audio compatible sound card @item Intel HD Audio Controller and HDA codec @item Adlib (OPL2) - Yamaha YM3812 compatible chip @item Gravis Ultrasound GF1 sound card @item CS4231A compatible sound card @item PCI UHCI, OHCI, EHCI or XHCI USB controller and a virtual USB-1.1 hub. @end itemize 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 @url{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. @example qemu-system-i386 dos.img -soundhw gus -parallel none @end example Alternatively: @example qemu-system-i386 dos.img -device gus,irq=5 @end example Or some other unclaimed IRQ. CS4231A is the chip used in Windows Sound System and GUSMAX products @c man end @node pcsys_quickstart @section Quick Start @cindex quick start Download and uncompress the linux image (@file{linux.img}) and type: @example qemu-system-i386 linux.img @end example Linux should boot and give you a prompt. @node sec_invocation @section Invocation @example @c man begin SYNOPSIS @command{qemu-system-i386} [@var{options}] [@var{disk_image}] @c man end @end example @c man begin OPTIONS @var{disk_image} is a raw hard disk image for IDE hard disk 0. Some targets do not need a disk image. @include qemu-options.texi @c man end @node pcsys_keys @section Keys in the graphical frontends @c man begin OPTIONS During the graphical emulation, you can use special key combinations to change modes. The default key mappings are shown below, but if you use @code{-alt-grab} then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use @code{-ctrl-grab} then the modifier is the right Ctrl key (instead of Ctrl-Alt): @table @key @item Ctrl-Alt-f @kindex Ctrl-Alt-f Toggle full screen @item Ctrl-Alt-+ @kindex Ctrl-Alt-+ Enlarge the screen @item Ctrl-Alt-- @kindex Ctrl-Alt-- Shrink the screen @item Ctrl-Alt-u @kindex Ctrl-Alt-u Restore the screen's un-scaled dimensions @item Ctrl-Alt-n @kindex Ctrl-Alt-n Switch to virtual console 'n'. Standard console mappings are: @table @emph @item 1 Target system display @item 2 Monitor @item 3 Serial port @end table @item Ctrl-Alt @kindex Ctrl-Alt Toggle mouse and keyboard grab. @end table @kindex Ctrl-Up @kindex Ctrl-Down @kindex Ctrl-PageUp @kindex Ctrl-PageDown In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down}, @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log. @c man end @node mux_keys @section Keys in the character backend multiplexer @c man begin OPTIONS During emulation, if you are using a character backend multiplexer (which is the default if you are using @option{-nographic}) then several commands are available via an escape sequence. These key sequences all start with an escape character, which is @key{Ctrl-a} by default, but can be changed with @option{-echr}. The list below assumes you're using the default. @table @key @item Ctrl-a h @kindex Ctrl-a h Print this help @item Ctrl-a x @kindex Ctrl-a x Exit emulator @item Ctrl-a s @kindex Ctrl-a s Save disk data back to file (if -snapshot) @item Ctrl-a t @kindex Ctrl-a t Toggle console timestamps @item Ctrl-a b @kindex Ctrl-a b Send break (magic sysrq in Linux) @item Ctrl-a c @kindex Ctrl-a c Rotate between the frontends connected to the multiplexer (usually this switches between the monitor and the console) @item Ctrl-a Ctrl-a @kindex Ctrl-a Ctrl-a Send the escape character to the frontend @end table @c man end @ignore @c man begin SEEALSO The HTML documentation of QEMU for more precise information and Linux user mode emulator invocation. @c man end @c man begin AUTHOR Fabrice Bellard @c man end @end ignore @node pcsys_monitor @section QEMU Monitor @cindex QEMU monitor The QEMU monitor is used to give complex commands to the QEMU emulator. You can use it to: @itemize @minus @item Remove or insert removable media images (such as CD-ROM or floppies). @item Freeze/unfreeze the Virtual Machine (VM) and save or restore its state from a disk file. @item Inspect the VM state without an external debugger. @end itemize @subsection Commands The following commands are available: @include qemu-monitor.texi @include qemu-monitor-info.texi @subsection 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 @emph{$}. @node disk_images @section Disk Images QEMU supports many disk image formats, including growable disk images (their size increase as non empty sectors are written), compressed and encrypted disk images. @menu * disk_images_quickstart:: Quick start for disk image creation * disk_images_snapshot_mode:: Snapshot mode * vm_snapshots:: VM snapshots * qemu_img_invocation:: qemu-img Invocation * qemu_nbd_invocation:: qemu-nbd Invocation * disk_images_formats:: Disk image file formats * host_drives:: Using host drives * disk_images_fat_images:: Virtual FAT disk images * disk_images_nbd:: NBD access * disk_images_sheepdog:: Sheepdog disk images * disk_images_iscsi:: iSCSI LUNs * disk_images_gluster:: GlusterFS disk images * disk_images_ssh:: Secure Shell (ssh) disk images @end menu @node disk_images_quickstart @subsection Quick start for disk image creation You can create a disk image with the command: @example qemu-img create myimage.img mysize @end example where @var{myimage.img} is the disk image filename and @var{mysize} is its size in kilobytes. You can add an @code{M} suffix to give the size in megabytes and a @code{G} suffix for gigabytes. See @ref{qemu_img_invocation} for more information. @node disk_images_snapshot_mode @subsection Snapshot mode If you use the option @option{-snapshot}, all disk images are considered as read only. When sectors in written, they are written in a temporary file created in @file{/tmp}. You can however force the write back to the raw disk images by using the @code{commit} monitor command (or @key{C-a s} in the serial console). @node vm_snapshots @subsection 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 @code{qcow2} disk image format. Normally this device is the first virtual hard drive. Use the monitor command @code{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 @code{loadvm} to restore a VM snapshot and @code{delvm} to remove a VM snapshot. @code{info snapshots} lists the available snapshots with their associated information: @example (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 @end example A VM snapshot is made of a VM state info (its size is shown in @code{info snapshots}) and a snapshot of every writable disk image. The VM state info is stored in the first @code{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 @code{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) @code{-snapshot} option (@ref{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: @itemize @item They cannot cope with removable devices if they are removed or inserted after a snapshot is done. @item A few device drivers still have incomplete snapshot support so their state is not saved or restored properly (in particular USB). @end itemize @node qemu_img_invocation @subsection @code{qemu-img} Invocation @include qemu-img.texi @node qemu_nbd_invocation @subsection @code{qemu-nbd} Invocation @include qemu-nbd.texi @node disk_images_formats @subsection 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 @code{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 @code{qemu-img create} and @code{qemu-img convert} using the @code{-o} option. This section describes each format and the options that are supported for it. @table @option @item 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 @emph{holes} (for example in ext2 or ext3 on Linux or NTFS on Windows), then only the written sectors will reserve space. Use @code{qemu-img info} to know the real size used by the image or @code{ls -ls} on Unix/Linux. Supported options: @table @code @item preallocation Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}). @code{falloc} mode preallocates space for image by calling posix_fallocate(). @code{full} mode preallocates space for image by writing zeros to underlying storage. @end table @item 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), zlib based compression and support of multiple VM snapshots. Supported options: @table @code @item compat Determines the qcow2 version to use. @code{compat=0.10} uses the traditional image format that can be read by any QEMU since 0.10. @code{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. @item backing_file File name of a base image (see @option{create} subcommand) @item backing_fmt Image format of the base image @item encryption This option is deprecated and equivalent to @code{encrypt.format=aes} @item encrypt.format If this is set to @code{luks}, it requests that the qcow2 payload (not qcow2 header) be encrypted using the LUKS format. The passphrase to use to unlock the LUKS key slot is given by the @code{encrypt.key-secret} parameter. LUKS encryption parameters can be tuned with the other @code{encrypt.*} parameters. If this is set to @code{aes}, the image is encrypted with 128-bit AES-CBC. The encryption key is given by the @code{encrypt.key-secret} parameter. This encryption format is considered to be flawed by modern cryptography standards, suffering from a number of design problems: @itemize @minus @item 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. @item The user passphrase is directly used as the encryption key. A poorly chosen or short passphrase will compromise the security of the encryption. @item 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. @end itemize The use of this is no longer supported in system emulators. Support only remains in the command line utilities, for the purposes of data liberation and interoperability with old versions of QEMU. The @code{luks} format should be used instead. @item encrypt.key-secret Provides the ID of a @code{secret} object that contains the passphrase (@code{encrypt.format=luks}) or encryption key (@code{encrypt.format=aes}). @item encrypt.cipher-alg Name of the cipher algorithm and key length. Currently defaults to @code{aes-256}. Only used when @code{encrypt.format=luks}. @item encrypt.cipher-mode Name of the encryption mode to use. Currently defaults to @code{xts}. Only used when @code{encrypt.format=luks}. @item encrypt.ivgen-alg Name of the initialization vector generator algorithm. Currently defaults to @code{plain64}. Only used when @code{encrypt.format=luks}. @item encrypt.ivgen-hash-alg Name of the hash algorithm to use with the initialization vector generator (if required). Defaults to @code{sha256}. Only used when @code{encrypt.format=luks}. @item encrypt.hash-alg Name of the hash algorithm to use for PBKDF algorithm Defaults to @code{sha256}. Only used when @code{encrypt.format=luks}. @item encrypt.iter-time Amount of time, in milliseconds, to use for PBKDF algorithm per key slot. Defaults to @code{2000}. Only used when @code{encrypt.format=luks}. @item 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. @item preallocation Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc}, @code{full}). An image with preallocated metadata is initially larger but can improve performance when the image needs to grow. @code{falloc} and @code{full} preallocations are like the same options of @code{raw} format, but sets up metadata also. @item lazy_refcounts If this option is set to @code{on}, reference count updates are postponed with the goal of avoiding metadata I/O and improving performance. This is particularly interesting with @option{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) @code{qemu-img check -r all} is required, which may take some time. This option can only be enabled if @code{compat=1.1} is specified. @item nocow If this option is set to @code{on}, it will turn 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 @code{nocow=on}. One can issue @code{lsattr filename} to check if the NOCOW flag is set or not (Capital 'C' is NOCOW flag). @end table @item 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 @code{lazy_refcounts=on} option to get a more QED-like behaviour. Supported options: @table @code @item backing_file File name of a base image (see @option{create} subcommand). @item 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. @item 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. @item 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. @end table @item qcow Old QEMU image format with support for backing files, compact image files, encryption and compression. Supported options: @table @code @item backing_file File name of a base image (see @option{create} subcommand) @item encryption This option is deprecated and equivalent to @code{encrypt.format=aes} @item encrypt.format If this is set to @code{aes}, the image is encrypted with 128-bit AES-CBC. The encryption key is given by the @code{encrypt.key-secret} parameter. This encryption format is considered to be flawed by modern cryptography standards, suffering from a number of design problems enumerated previously against the @code{qcow2} image format. The use of this is no longer supported in system emulators. Support only remains in the command line utilities, for the purposes of data liberation and interoperability with old versions of QEMU. Users requiring native encryption should use the @code{qcow2} format instead with @code{encrypt.format=luks}. @item encrypt.key-secret Provides the ID of a @code{secret} object that contains the encryption key (@code{encrypt.format=aes}). @end table @item luks LUKS v1 encryption format, compatible with Linux dm-crypt/cryptsetup Supported options: @table @code @item key-secret Provides the ID of a @code{secret} object that contains the passphrase. @item cipher-alg Name of the cipher algorithm and key length. Currently defaults to @code{aes-256}. @item cipher-mode Name of the encryption mode to use. Currently defaults to @code{xts}. @item ivgen-alg Name of the initialization vector generator algorithm. Currently defaults to @code{plain64}. @item ivgen-hash-alg Name of the hash algorithm to use with the initialization vector generator (if required). Defaults to @code{sha256}. @item hash-alg Name of the hash algorithm to use for PBKDF algorithm Defaults to @code{sha256}. @item iter-time Amount of time, in milliseconds, to use for PBKDF algorithm per key slot. Defaults to @code{2000}. @end table @item vdi VirtualBox 1.1 compatible image format. Supported options: @table @code @item static If this option is set to @code{on}, the image is created with metadata preallocation. @end table @item vmdk VMware 3 and 4 compatible image format. Supported options: @table @code @item backing_file File name of a base image (see @option{create} subcommand). @item compat6 Create a VMDK version 6 image (instead of version 4) @item hwversion Specify vmdk virtual hardware version. Compat6 flag cannot be enabled if hwversion is specified. @item subformat Specifies which VMDK subformat to use. Valid options are @code{monolithicSparse} (default), @code{monolithicFlat}, @code{twoGbMaxExtentSparse}, @code{twoGbMaxExtentFlat} and @code{streamOptimized}. @end table @item vpc VirtualPC compatible image format (VHD). Supported options: @table @code @item subformat Specifies which VHD subformat to use. Valid options are @code{dynamic} (default) and @code{fixed}. @end table @item VHDX Hyper-V compatible image format (VHDX). Supported options: @table @code @item subformat Specifies which VHDX subformat to use. Valid options are @code{dynamic} (default) and @code{fixed}. @item block_state_zero Force use of payload blocks of type 'ZERO'. Can be set to @code{on} (default) or @code{off}. When set to @code{off}, new blocks will be created as @code{PAYLOAD_BLOCK_NOT_PRESENT}, which means parsers are free to return arbitrary data for those blocks. Do not set to @code{off} when using @code{qemu-img convert} with @code{subformat=dynamic}. @item block_size Block size; min 1 MB, max 256 MB. 0 means auto-calculate based on image size. @item log_size Log size; min 1 MB. @end table @end table @subsubsection Read-only formats More disk image file formats are supported in a read-only mode. @table @option @item bochs Bochs images of @code{growing} type. @item cloop Linux Compressed Loop image, useful only to reuse directly compressed CD-ROM images present for example in the Knoppix CD-ROMs. @item dmg Apple disk image. @item parallels Parallels disk image format. @end table @node host_drives @subsection 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. @subsubsection 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 @file{/dev/cdrom} to access to the CDROM. @table @code @item 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. @item 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). Use of the host's floppy device is deprecated, and support for it will be removed in a future release. @item Hard disks Hard disks can be used. Normally you must specify the whole disk (@file{/dev/hdb} instead of @file{/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 @option{-snapshot} command line option or modify the device permissions accordingly). @end table @subsubsection Windows @table @code @item CD The preferred syntax is the drive letter (e.g. @file{d:}). The alternate syntax @file{\\.\d:} is supported. @file{/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 @code{change} or @code{eject} monitor commands to change or eject media. @item Hard disks Hard disks can be used with the syntax: @file{\\.\PhysicalDrive@var{N}} where @var{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 @option{-snapshot} command line so that the modifications are written in a temporary file). @end table @subsubsection Mac OS X @file{/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 @code{change} or @code{eject} monitor commands to change or eject media. @node disk_images_fat_images @subsection Virtual FAT disk images QEMU can automatically create a virtual FAT disk image from a directory tree. In order to use it, just type: @example qemu-system-i386 linux.img -hdb fat:/my_directory @end example Then you access access to all the files in the @file{/my_directory} directory without having to copy them in a disk image or to export them via SAMBA or NFS. The default access is @emph{read-only}. Floppies can be emulated with the @code{:floppy:} option: @example qemu-system-i386 linux.img -fda fat:floppy:/my_directory @end example A read/write support is available for testing (beta stage) with the @code{:rw:} option: @example qemu-system-i386 linux.img -fda fat:floppy:rw:/my_directory @end example What you should @emph{never} do: @itemize @item use non-ASCII filenames ; @item use "-snapshot" together with ":rw:" ; @item expect it to work when loadvm'ing ; @item write to the FAT directory on the host system while accessing it with the guest system. @end itemize @node disk_images_nbd @subsection NBD access QEMU can access directly to block device exported using the Network Block Device protocol. @example qemu-system-i386 linux.img -hdb nbd://my_nbd_server.mydomain.org:1024/ @end example If the NBD server is located on the same host, you can use an unix socket instead of an inet socket: @example qemu-system-i386 linux.img -hdb nbd+unix://?socket=/tmp/my_socket @end example In this case, the block device must be exported using qemu-nbd: @example qemu-nbd --socket=/tmp/my_socket my_disk.qcow2 @end example The use of qemu-nbd allows sharing of a disk between several guests: @example qemu-nbd --socket=/tmp/my_socket --share=2 my_disk.qcow2 @end example @noindent and then you can use it with two guests: @example qemu-system-i386 linux1.img -hdb nbd+unix://?socket=/tmp/my_socket qemu-system-i386 linux2.img -hdb nbd+unix://?socket=/tmp/my_socket @end example 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: @example qemu-system-i386 -cdrom nbd://localhost/debian-500-ppc-netinst qemu-system-i386 -cdrom nbd://localhost/openSUSE-11.1-ppc-netinst @end example 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: @example 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 @end example @node disk_images_sheepdog @subsection 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: @example qemu-img create sheepdog:///@var{image} @var{size} @end example where @var{image} is the Sheepdog image name and @var{size} is its size. To import the existing @var{filename} to Sheepdog, you can use a convert command. @example qemu-img convert @var{filename} sheepdog:///@var{image} @end example You can boot from the Sheepdog disk image with the command: @example qemu-system-i386 sheepdog:///@var{image} @end example You can also create a snapshot of the Sheepdog image like qcow2. @example qemu-img snapshot -c @var{tag} sheepdog:///@var{image} @end example where @var{tag} is a tag name of the newly created snapshot. To boot from the Sheepdog snapshot, specify the tag name of the snapshot. @example qemu-system-i386 sheepdog:///@var{image}#@var{tag} @end example You can create a cloned image from the existing snapshot. @example qemu-img create -b sheepdog:///@var{base}#@var{tag} sheepdog:///@var{image} @end example where @var{base} is a image name of the source snapshot and @var{tag} is its tag name. You can use an unix socket instead of an inet socket: @example qemu-system-i386 sheepdog+unix:///@var{image}?socket=@var{path} @end example If the Sheepdog daemon doesn't run on the local host, you need to specify one of the Sheepdog servers to connect to. @example qemu-img create sheepdog://@var{hostname}:@var{port}/@var{image} @var{size} qemu-system-i386 sheepdog://@var{hostname}:@var{port}/@var{image} @end example @node disk_images_iscsi @subsection 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 @example URL syntax: iscsi://[<username>[%<password>]@@]<host>[:<port>]/<target-iqn-name>/<lun> @end example 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 @example export LIBISCSI_CHAP_USERNAME=<username> export LIBISCSI_CHAP_PASSWORD=<password> iscsi://<host>/<target-iqn-name>/<lun> @end example 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[:<uuid>'] where <uuid> is the UUID of the virtual machine. If the UUID is not specified qemu will use 'iqn.2008-11.org.linux-kvm[:<name>'] where <name> is the name of the virtual machine. @example Setting a specific initiator name to use when logging in to the target -iscsi initiator-name=iqn.qemu.test:my-initiator @end example @example Controlling which type of header digest to negotiate with the target -iscsi header-digest=CRC32C|CRC32C-NONE|NONE-CRC32C|NONE @end example These can also be set via a configuration file @example [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" @end example Setting the target name allows different options for different targets @example [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" @end example Howto use a configuration file to set iSCSI configuration options: @example 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 @end example Howto set up a simple iSCSI target on loopback and accessing it via QEMU: @example 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 @end example @node disk_images_gluster @subsection GlusterFS disk images GlusterFS is a user space distributed file system. You can boot from the GlusterFS disk image with the command: @example URI: qemu-system-x86_64 -drive file=gluster[+@var{type}]://[@var{host}[:@var{port}]]/@var{volume}/@var{path} [?socket=...][,file.debug=9][,file.logfile=...] JSON: qemu-system-x86_64 'json:@{"driver":"qcow2", "file":@{"driver":"gluster", "volume":"testvol","path":"a.img","debug":9,"logfile":"...", "server":[@{"type":"tcp","host":"...","port":"..."@}, @{"type":"unix","socket":"..."@}]@}@}' @end example @var{gluster} is the protocol. @var{type} specifies the transport type used to connect to gluster management daemon (glusterd). Valid transport types are tcp and unix. In the URI form, if a transport type isn't specified, then tcp type is assumed. @var{host} specifies the server where the volume file specification for the given volume resides. This can be either a hostname or an ipv4 address. If transport type is unix, then @var{host} field should not be specified. Instead @var{socket} field needs to be populated with the path to unix domain socket. @var{port} is the port number on which glusterd is listening. This is optional and if not specified, it defaults to port 24007. If the transport type is unix, then @var{port} should not be specified. @var{volume} is the name of the gluster volume which contains the disk image. @var{path} is the path to the actual disk image that resides on gluster volume. @var{debug} is the logging level of the gluster protocol driver. Debug levels are 0-9, with 9 being the most verbose, and 0 representing no debugging output. The default level is 4. The current logging levels defined in the gluster source are 0 - None, 1 - Emergency, 2 - Alert, 3 - Critical, 4 - Error, 5 - Warning, 6 - Notice, 7 - Info, 8 - Debug, 9 - Trace @var{logfile} is a commandline option to mention log file path which helps in logging to the specified file and also help in persisting the gfapi logs. The default is stderr. You can create a GlusterFS disk image with the command: @example qemu-img create gluster://@var{host}/@var{volume}/@var{path} @var{size} @end example Examples @example 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 qemu-system-x86_64 -drive file=gluster://1.2.3.4/testvol/a.img,file.debug=9,file.logfile=/var/log/qemu-gluster.log qemu-system-x86_64 'json:@{"driver":"qcow2", "file":@{"driver":"gluster", "volume":"testvol","path":"a.img", "debug":9,"logfile":"/var/log/qemu-gluster.log", "server":[@{"type":"tcp","host":"1.2.3.4","port":24007@}, @{"type":"unix","socket":"/var/run/glusterd.socket"@}]@}@}' qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img, file.debug=9,file.logfile=/var/log/qemu-gluster.log, file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007, file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket @end example @node disk_images_ssh @subsection Secure Shell (ssh) disk images You can access disk images located on a remote ssh server by using the ssh protocol: @example qemu-system-x86_64 -drive file=ssh://[@var{user}@@]@var{server}[:@var{port}]/@var{path}[?host_key_check=@var{host_key_check}] @end example Alternative syntax using properties: @example 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}] @end example @var{ssh} is the protocol. @var{user} is the remote user. If not specified, then the local username is tried. @var{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. @var{port} is the port number on which sshd is listening. By default the standard ssh port (22) is used. @var{path} is the path to the disk image. The optional @var{host_key_check} parameter controls how the remote host's key is checked. The default is @code{yes} which means to use the local @file{.ssh/known_hosts} file. Setting this to @code{no} turns off known-hosts checking. Or you can check that the host key matches a specific fingerprint: @code{host_key_check=md5:78:45:8e:14:57:4f:d5:45:83:0a:0e:f3:49:82:c9:c8} (@code{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 @code{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 @code{fsync} is not supported: warning: ssh server @code{ssh.example.com:22} does not support fsync With sufficiently new versions of libssh2 and OpenSSH, @code{fsync} is supported. @node pcsys_network @section 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. @subsection 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). @subsection 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 @code{tapN}), and you can then configure it as if it was a real ethernet card. @subsubsection Linux host As an example, you can download the @file{linux-test-xxx.tar.gz} archive and copy the script @file{qemu-ifup} in @file{/etc} and configure properly @code{sudo} so that the command @code{ifconfig} contained in @file{qemu-ifup} can be executed as root. You must verify that your host kernel supports the TAP network interfaces: the device @file{/dev/net/tun} must be present. See @ref{sec_invocation} to have examples of command lines using the TAP network interfaces. @subsubsection 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 : @url{http://openvpn.net/}. @subsection Using the user mode network stack By using the option @option{-net user} (default configuration if no @option{-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: @example QEMU VLAN <------> Firewall/DHCP server <-----> Internet | (10.0.2.2) | ----> DNS server (10.0.2.3) | ----> SMB server (10.0.2.4) @end example 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 ICMP traffic in general does not work with user mode networking. @code{ping}, aka. ICMP echo, to the local router (10.0.2.2) shall work, however. If you're using QEMU on Linux >= 3.0, it can use unprivileged ICMP ping sockets to allow @code{ping} to the Internet. The host admin has to set the ping_group_range in order to grant access to those sockets. To allow ping for GID 100 (usually users group): @example echo 100 100 > /proc/sys/net/ipv4/ping_group_range @end example When using the built-in TFTP server, the router is also the TFTP server. When using the @option{'-netdev user,hostfwd=...'} 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. @subsection Connecting VLANs between QEMU instances Using the @option{-net socket} option, it is possible to make VLANs that span several QEMU instances. See @ref{sec_invocation} to have a basic example. @node pcsys_other_devs @section Other Devices @subsection Inter-VM Shared Memory device On Linux hosts, a shared memory device is available. The basic syntax is: @example qemu-system-x86_64 -device ivshmem-plain,memdev=@var{hostmem} @end example where @var{hostmem} names a host memory backend. For a POSIX shared memory backend, use something like @example -object memory-backend-file,size=1M,share,mem-path=/dev/shm/ivshmem,id=@var{hostmem} @end example 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: @example # First start the ivshmem server once and for all ivshmem-server -p @var{pidfile} -S @var{path} -m @var{shm-name} -l @var{shm-size} -n @var{vectors} # Then start your qemu instances with matching arguments qemu-system-x86_64 -device ivshmem-doorbell,vectors=@var{vectors},chardev=@var{id} -chardev socket,path=@var{path},id=@var{id} @end example 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 ivshmem-spec.txt). @subsubsection Migration with ivshmem With device property @option{master=on}, the guest will copy the shared memory on migration to the destination host. With @option{master=off}, the guest will not be able to migrate with the device attached. In the latter case, the device should be detached and then reattached after migration using the PCI hotplug support. At most one of the devices sharing the same memory can be master. The master must complete migration before you plug back the other devices. @subsubsection ivshmem and hugepages Instead of specifying the <shm size> using POSIX shm, you may specify a memory backend that has hugepage support: @example qemu-system-x86_64 -object memory-backend-file,size=1G,mem-path=/dev/hugepages/my-shmem-file,share,id=mb1 -device ivshmem-plain,memdev=mb1 @end example ivshmem-server also supports hugepages mount points with the @option{-m} memory path argument. @node direct_linux_boot @section 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: @example qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda" @end example Use @option{-kernel} to provide the Linux kernel image and @option{-append} to give the kernel command line arguments. The @option{-initrd} option can be used to provide an INITRD image. When using the direct Linux boot, a disk image for the first hard disk @file{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 @option{-nographic} option. The typical command line is: @example qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \ -append "root=/dev/hda console=ttyS0" -nographic @end example Use @key{Ctrl-a c} to switch between the serial console and the monitor (@pxref{pcsys_keys}). @node pcsys_usb @section USB emulation QEMU can emulate a PCI UHCI, OHCI, EHCI or XHCI USB controller. You can plug virtual USB devices or real host USB devices (only works with certain host operating systems). QEMU will automatically create and connect virtual USB hubs as necessary to connect multiple USB devices. @menu * usb_devices:: * host_usb_devices:: @end menu @node usb_devices @subsection Connecting USB devices USB devices can be connected with the @option{-device usb-...} command line option or the @code{device_add} monitor command. Available devices are: @table @code @item usb-mouse Virtual Mouse. This will override the PS/2 mouse emulation when activated. @item usb-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. @item usb-storage,drive=@var{drive_id} Mass storage device backed by @var{drive_id} (@pxref{disk_images}) @item usb-uas USB attached SCSI device, see @url{http://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/usb-storage.txt,usb-storage.txt} for details @item usb-bot Bulk-only transport storage device, see @url{http://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/usb-storage.txt,usb-storage.txt} for details here, too @item usb-mtp,x-root=@var{dir} Media transfer protocol device, using @var{dir} as root of the file tree that is presented to the guest. @item usb-host,hostbus=@var{bus},hostaddr=@var{addr} Pass through the host device identified by @var{bus} and @var{addr} @item usb-host,vendorid=@var{vendor},productid=@var{product} Pass through the host device identified by @var{vendor} and @var{product} ID @item usb-wacom-tablet Virtual Wacom PenPartner tablet. This device is similar to the @code{tablet} above but it can be used with the tslib library because in addition to touch coordinates it reports touch pressure. @item usb-kbd Standard USB keyboard. Will override the PS/2 keyboard (if present). @item usb-serial,chardev=@var{id} Serial converter. This emulates an FTDI FT232BM chip connected to host character device @var{id}. @item usb-braille,chardev=@var{id} Braille device. This will use BrlAPI to display the braille output on a real or fake device referenced by @var{id}. @item usb-net[,netdev=@var{id}] Network adapter that supports CDC ethernet and RNDIS protocols. @var{id} specifies a netdev defined with @code{-netdev @dots{},id=@var{id}}. For instance, user-mode networking can be used with @example qemu-system-i386 [...] -netdev user,id=net0 -device usb-net,netdev=net0 @end example @item usb-ccid Smartcard reader device @item usb-audio USB audio device @item usb-bt-dongle Bluetooth dongle for the transport layer of HCI. It is connected to HCI scatternet 0 by default (corresponds to @code{-bt hci,vlan=0}). Note that the syntax for the @code{-device usb-bt-dongle} option is not as useful yet as it was with the legacy @code{-usbdevice} option. So to configure an USB bluetooth device, you might need to use "@code{-usbdevice bt}[:@var{hci-type}]" instead. This configures a bluetooth dongle whose type is specified in the same format as with the @option{-bt hci} option, @pxref{bt-hcis,,allowed HCI types}. If no type is given, the HCI logic corresponds to @code{-bt hci,vlan=0}. This USB device implements the USB Transport Layer of HCI. Example usage: @example @command{qemu-system-i386} [...@var{OPTIONS}...] @option{-usbdevice} bt:hci,vlan=3 @option{-bt} device:keyboard,vlan=3 @end example @end table @node host_usb_devices @subsection 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. @enumerate @item 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 @file{mydriver.o} to @file{mydriver.o.disabled}. @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that: @example ls /proc/bus/usb 001 devices drivers @end example @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: @example chown -R myuid /proc/bus/usb @end example @item Launch QEMU and do in the monitor: @example info usbhost Device 1.2, speed 480 Mb/s Class 00: USB device 1234:5678, USB DISK @end example You should see the list of the devices you can use (Never try to use hubs, it won't work). @item Add the device in QEMU by using: @example device_add usb-host,vendorid=0x1234,productid=0x5678 @end example Normally the guest OS should report that a new USB device is plugged. You can use the option @option{-device usb-host,...} to do the same. @item Now you can try to use the host USB device in QEMU. @end enumerate When relaunching QEMU, you may have to unplug and plug again the USB device to make it work again (this is a bug). @node vnc_security @section 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. @menu * vnc_sec_none:: * vnc_sec_password:: * vnc_sec_certificate:: * vnc_sec_certificate_verify:: * vnc_sec_certificate_pw:: * vnc_sec_sasl:: * vnc_sec_certificate_sasl:: * vnc_generate_cert:: * vnc_setup_sasl:: @end menu @node vnc_sec_none @subsection 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 @example qemu-system-i386 [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc @end example 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. @node vnc_sec_password @subsection 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 @code{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. @example qemu-system-i386 [...OPTIONS...] -vnc :1,password -monitor stdio (qemu) change vnc password Password: ******** (qemu) @end example @node vnc_sec_certificate @subsection 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. @example qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio @end example In the above example @code{/etc/pki/qemu} should contain at least three files, @code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged users will want to use a private directory, for example @code{$HOME/.pki/qemu}. NB the @code{server-key.pem} file should be protected with file mode 0600 to only be readable by the user owning it. @node vnc_sec_certificate_verify @subsection 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. @example qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio @end example @node vnc_sec_certificate_pw @subsection 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. @example qemu-system-i386 [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio (qemu) change vnc password Password: ******** (qemu) @end example @node vnc_sec_sasl @subsection 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: @example qemu-system-i386 [...OPTIONS...] -vnc :1,sasl -monitor stdio @end example @node vnc_sec_certificate_sasl @subsection 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: @example qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509,sasl -monitor stdio @end example @node vnc_generate_cert @subsection Generating certificates for VNC The GNU TLS packages provides a command called @code{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 @code{/etc/pki/qemu} or for unprivileged users in @code{$HOME/.pki/qemu}. @menu * vnc_generate_ca:: * vnc_generate_server:: * vnc_generate_client:: @end menu @node vnc_generate_ca @subsubsection 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. @example # certtool --generate-privkey > ca-key.pem @end example 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. @example # 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 @end example The @code{ca-cert.pem} file should be copied to all servers and clients wishing to utilize TLS support in the VNC server. The @code{ca-key.pem} must not be disclosed/copied at all. @node vnc_generate_server @subsubsection 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: @example # 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-key.pem \ --template server.info \ --outfile server-cert.pem @end example The @code{server-key.pem} and @code{server-cert.pem} files should now be securely copied to the server for which they were generated. The @code{server-key.pem} is security sensitive and should be kept protected with file mode 0600 to prevent disclosure. @node vnc_generate_client @subsubsection Issuing client certificates If the QEMU VNC server is to use the @code{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: @example # cat > client.info <<EOF country = GB state = London locality = London organization = 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 @end example The @code{client-key.pem} and @code{client-cert.pem} files should now be securely copied to the client for which they were generated. @node vnc_setup_sasl @subsection 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. If the TLS option is enabled for VNC, then it will provide session encryption, otherwise the SASL mechanism will have to provide encryption. In the latter case the list of possible plugins that can be used is drastically reduced. In fact only the GSSAPI SASL mechanism provides an acceptable level of security by modern standards. Previous versions of QEMU referred to the DIGEST-MD5 mechanism, however, it has multiple serious flaws described in detail in RFC 6331 and thus should never be used any more. The SCRAM-SHA-1 mechanism provides a simple username/password auth facility similar to DIGEST-MD5, but does not support session encryption, so can only be used in combination with TLS. When not using TLS the recommended configuration is @example mech_list: gssapi keytab: /etc/qemu/krb5.tab @end example This says to use the 'GSSAPI' mechanism with the Kerberos v5 protocol, with the server principal stored in /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. When using TLS, if username+password authentication is desired, then a reasonable configuration is @example mech_list: scram-sha-1 sasldb_path: /etc/qemu/passwd.db @end example The saslpasswd2 program can be used to populate the passwd.db file with accounts. Other SASL configurations will be left as an exercise for the reader. Note that all mechanisms except GSSAPI, should be combined with use of TLS to ensure a secure data channel. @node gdb_usage @section 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: @example 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 @end example Then launch gdb on the 'vmlinux' executable: @example > gdb vmlinux @end example In gdb, connect to QEMU: @example (gdb) target remote localhost:1234 @end example Then you can use gdb normally. For example, type 'c' to launch the kernel: @example (gdb) c @end example Here are some useful tips in order to use gdb on system code: @enumerate @item Use @code{info reg} to display all the CPU registers. @item Use @code{x/10i $eip} to display the code at the PC position. @item Use @code{set architecture i8086} to dump 16 bit code. Then use @code{x/10i $cs*16+$eip} to dump the code at the PC position. @end enumerate 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 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: @table @code @item maintenance packet qqemu.sstepbits This will display the MASK bits used to control the single stepping IE: @example (gdb) maintenance packet qqemu.sstepbits sending: "qqemu.sstepbits" received: "ENABLE=1,NOIRQ=2,NOTIMER=4" @end example @item maintenance packet qqemu.sstep This will display the current value of the mask used when single stepping IE: @example (gdb) maintenance packet qqemu.sstep sending: "qqemu.sstep" received: "0x7" @end example @item 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: @example (gdb) maintenance packet Qqemu.sstep=0x5 sending: "qemu.sstep=0x5" received: "OK" @end example @end table @node pcsys_os_specific @section Target OS specific information @subsection Linux To have access to SVGA graphic modes under X11, use the @code{vesa} or the @code{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 @code{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. @subsection 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. @subsubsection 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 @option{-std-vga}). @subsubsection 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 @url{http://web.archive.org/web/20060212132151/http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this problem. Note that no such tool is needed for NT, 2000 or XP. @subsubsection Windows 2000 disk full problem Windows 2000 has a bug which gives a disk full problem during its installation. When installing it, use the @option{-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). @subsubsection 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. @subsubsection Share a directory between Unix and Windows See @ref{sec_invocation} about the help of the option @option{'-netdev user,smb=...'}. @subsubsection Windows XP security problem Some releases of Windows XP install correctly but give a security error when booting: @example A problem is preventing Windows from accurately checking the license for this computer. Error code: 0x800703e6. @end example 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"). @subsection MS-DOS and FreeDOS @subsubsection 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 @url{http://web.archive.org/web/20051222085335/http://www.vmware.com/software/dosidle210.zip} to solve this problem. @node QEMU System emulator for non PC targets @chapter 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. @menu * PowerPC System emulator:: * Sparc32 System emulator:: * Sparc64 System emulator:: * MIPS System emulator:: * ARM System emulator:: * ColdFire System emulator:: * Cris System emulator:: * Microblaze System emulator:: * SH4 System emulator:: * Xtensa System emulator:: @end menu @node PowerPC System emulator @section PowerPC System emulator @cindex system emulation (PowerPC) Use the executable @file{qemu-system-ppc} to simulate a complete PREP or PowerMac PowerPC system. QEMU emulates the following PowerMac peripherals: @itemize @minus @item UniNorth or Grackle PCI Bridge @item PCI VGA compatible card with VESA Bochs Extensions @item 2 PMAC IDE interfaces with hard disk and CD-ROM support @item NE2000 PCI adapters @item Non Volatile RAM @item VIA-CUDA with ADB keyboard and mouse. @end itemize QEMU emulates the following PREP peripherals: @itemize @minus @item PCI Bridge @item PCI VGA compatible card with VESA Bochs Extensions @item 2 IDE interfaces with hard disk and CD-ROM support @item Floppy disk @item NE2000 network adapters @item Serial port @item PREP Non Volatile RAM @item PC compatible keyboard and mouse. @end itemize QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at @url{http://perso.magic.fr/l_indien/OpenHackWare/index.htm}. Since version 0.9.1, QEMU uses OpenBIOS @url{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. @c man begin OPTIONS The following options are specific to the PowerPC emulation: @table @option @item -g @var{W}x@var{H}[x@var{DEPTH}] Set the initial VGA graphic mode. The default is 800x600x32. @item -prom-env @var{string} Set OpenBIOS variables in NVRAM, for example: @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' @end example These variables are not used by Open Hack'Ware. @end table @c man end More information is available at @url{http://perso.magic.fr/l_indien/qemu-ppc/}. @node Sparc32 System emulator @section Sparc32 System emulator @cindex system emulation (Sparc32) Use the executable @file{qemu-system-sparc} to simulate the following Sun4m architecture machines: @itemize @minus @item SPARCstation 4 @item SPARCstation 5 @item SPARCstation 10 @item SPARCstation 20 @item SPARCserver 600MP @item SPARCstation LX @item SPARCstation Voyager @item SPARCclassic @item SPARCbook @end itemize 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: @itemize @minus @item IOMMU @item TCX or cgthree Frame buffer @item Lance (Am7990) Ethernet @item Non Volatile RAM M48T02/M48T08 @item Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard and power/reset logic @item ESP SCSI controller with hard disk and CD-ROM support @item Floppy drive (not on SS-600MP) @item CS4231 sound device (only on SS-5, not working yet) @end itemize 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 @url{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 most kernel versions work. Please note that currently older Solaris kernels don't work probably due to interface issues between OpenBIOS and Solaris. @c man begin OPTIONS The following options are specific to the Sparc32 emulation: @table @option @item -g @var{W}x@var{H}x[x@var{DEPTH}] 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. @item -prom-env @var{string} Set OpenBIOS variables in NVRAM, for example: @example qemu-system-sparc -prom-env 'auto-boot?=false' \ -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' @end example @item -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic] [|SPARCbook] Set the emulated machine type. Default is SS-5. @end table @c man end @node Sparc64 System emulator @section Sparc64 System emulator @cindex system emulation (Sparc64) Use the executable @file{qemu-system-sparc64} to simulate a Sun4u (UltraSPARC PC-like machine), Sun4v (T1 PC-like machine), or generic Niagara (T1) machine. The Sun4u emulator is mostly complete, being able to run Linux, NetBSD and OpenBSD in headless (-nographic) mode. The Sun4v emulator is still a work in progress. The Niagara T1 emulator makes use of firmware and OS binaries supplied in the S10image/ directory of the OpenSPARC T1 project @url{http://download.oracle.com/technetwork/systems/opensparc/OpenSPARCT1_Arch.1.5.tar.bz2} and is able to boot the disk.s10hw2 Solaris image. @example qemu-system-sparc64 -M niagara -L /path-to/S10image/ \ -nographic -m 256 \ -drive if=pflash,readonly=on,file=/S10image/disk.s10hw2 @end example QEMU emulates the following peripherals: @itemize @minus @item UltraSparc IIi APB PCI Bridge @item PCI VGA compatible card with VESA Bochs Extensions @item PS/2 mouse and keyboard @item Non Volatile RAM M48T59 @item PC-compatible serial ports @item 2 PCI IDE interfaces with hard disk and CD-ROM support @item Floppy disk @end itemize @c man begin OPTIONS The following options are specific to the Sparc64 emulation: @table @option @item -prom-env @var{string} Set OpenBIOS variables in NVRAM, for example: @example qemu-system-sparc64 -prom-env 'auto-boot?=false' @end example @item -M [sun4u|sun4v|niagara] Set the emulated machine type. The default is sun4u. @end table @c man end @node MIPS System emulator @section MIPS System emulator @cindex system emulation (MIPS) Four executables cover simulation of 32 and 64-bit MIPS systems in both endian options, @file{qemu-system-mips}, @file{qemu-system-mipsel} @file{qemu-system-mips64} and @file{qemu-system-mips64el}. Five different machine types are emulated: @itemize @minus @item A generic ISA PC-like machine "mips" @item The MIPS Malta prototype board "malta" @item An ACER Pica "pica61". This machine needs the 64-bit emulator. @item MIPS emulator pseudo board "mipssim" @item A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator. @end itemize The generic emulation is supported by Debian 'Etch' and is able to install Debian into a virtual disk image. The following devices are emulated: @itemize @minus @item A range of MIPS CPUs, default is the 24Kf @item PC style serial port @item PC style IDE disk @item NE2000 network card @end itemize The Malta emulation supports the following devices: @itemize @minus @item Core board with MIPS 24Kf CPU and Galileo system controller @item PIIX4 PCI/USB/SMbus controller @item The Multi-I/O chip's serial device @item PCI network cards (PCnet32 and others) @item Malta FPGA serial device @item Cirrus (default) or any other PCI VGA graphics card @end itemize The ACER Pica emulation supports: @itemize @minus @item MIPS R4000 CPU @item PC-style IRQ and DMA controllers @item PC Keyboard @item IDE controller @end itemize The mipssim pseudo board emulation provides an environment similar to what the proprietary MIPS emulator uses for running Linux. It supports: @itemize @minus @item A range of MIPS CPUs, default is the 24Kf @item PC style serial port @item MIPSnet network emulation @end itemize The MIPS Magnum R4000 emulation supports: @itemize @minus @item MIPS R4000 CPU @item PC-style IRQ controller @item PC Keyboard @item SCSI controller @item G364 framebuffer @end itemize @node ARM System emulator @section ARM System emulator @cindex system emulation (ARM) Use the executable @file{qemu-system-arm} to simulate a ARM machine. The ARM Integrator/CP board is emulated with the following devices: @itemize @minus @item ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU @item Two PL011 UARTs @item SMC 91c111 Ethernet adapter @item PL110 LCD controller @item PL050 KMI with PS/2 keyboard and mouse. @item PL181 MultiMedia Card Interface with SD card. @end itemize The ARM Versatile baseboard is emulated with the following devices: @itemize @minus @item ARM926E, ARM1136 or Cortex-A8 CPU @item PL190 Vectored Interrupt Controller @item Four PL011 UARTs @item SMC 91c111 Ethernet adapter @item PL110 LCD controller @item PL050 KMI with PS/2 keyboard and mouse. @item 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. @item PCI OHCI USB controller. @item LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices. @item PL181 MultiMedia Card Interface with SD card. @end itemize 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: @itemize @minus @item ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU @item ARM AMBA Generic/Distributed Interrupt Controller @item Four PL011 UARTs @item SMC 91c111 or SMSC LAN9118 Ethernet adapter @item PL110 LCD controller @item PL050 KMI with PS/2 keyboard and mouse @item PCI host bridge @item PCI OHCI USB controller @item LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices @item PL181 MultiMedia Card Interface with SD card. @end itemize The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi" and "Terrier") emulation includes the following peripherals: @itemize @minus @item Intel PXA270 System-on-chip (ARM V5TE core) @item NAND Flash memory @item IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita" @item On-chip OHCI USB controller @item On-chip LCD controller @item On-chip Real Time Clock @item TI ADS7846 touchscreen controller on SSP bus @item Maxim MAX1111 analog-digital converter on I@math{^2}C bus @item GPIO-connected keyboard controller and LEDs @item Secure Digital card connected to PXA MMC/SD host @item Three on-chip UARTs @item WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses @end itemize The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the following elements: @itemize @minus @item Texas Instruments OMAP310 System-on-chip (ARM 925T core) @item ROM and RAM memories (ROM firmware image can be loaded with -option-rom) @item On-chip LCD controller @item On-chip Real Time Clock @item TI TSC2102i touchscreen controller / analog-digital converter / Audio CODEC, connected through MicroWire and I@math{^2}S busses @item GPIO-connected matrix keypad @item Secure Digital card connected to OMAP MMC/SD host @item Three on-chip UARTs @end itemize Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48) emulation supports the following elements: @itemize @minus @item Texas Instruments OMAP2420 System-on-chip (ARM 1136 core) @item RAM and non-volatile OneNAND Flash memories @item Display connected to EPSON remote framebuffer chip and OMAP on-chip display controller and a LS041y3 MIPI DBI-C controller @item TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers driven through SPI bus @item National Semiconductor LM8323-controlled qwerty keyboard driven through I@math{^2}C bus @item Secure Digital card connected to OMAP MMC/SD host @item Three OMAP on-chip UARTs and on-chip STI debugging console @item A Bluetooth(R) transceiver and HCI connected to an UART @item Mentor Graphics "Inventra" dual-role USB controller embedded in a TI TUSB6010 chip - only USB host mode is supported @item TI TMP105 temperature sensor driven through I@math{^2}C bus @item TI TWL92230C power management companion with an RTC on I@math{^2}C bus @item Nokia RETU and TAHVO multi-purpose chips with an RTC, connected through CBUS @end itemize The Luminary Micro Stellaris LM3S811EVB emulation includes the following devices: @itemize @minus @item Cortex-M3 CPU core. @item 64k Flash and 8k SRAM. @item Timers, UARTs, ADC and I@math{^2}C interface. @item OSRAM Pictiva 96x16 OLED with SSD0303 controller on I@math{^2}C bus. @end itemize The Luminary Micro Stellaris LM3S6965EVB emulation includes the following devices: @itemize @minus @item Cortex-M3 CPU core. @item 256k Flash and 64k SRAM. @item Timers, UARTs, ADC, I@math{^2}C and SSI interfaces. @item OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI. @end itemize The Freecom MusicPal internet radio emulation includes the following elements: @itemize @minus @item Marvell MV88W8618 ARM core. @item 32 MB RAM, 256 KB SRAM, 8 MB flash. @item Up to 2 16550 UARTs @item MV88W8xx8 Ethernet controller @item MV88W8618 audio controller, WM8750 CODEC and mixer @item 128×64 display with brightness control @item 2 buttons, 2 navigation wheels with button function @end itemize The Siemens SX1 models v1 and v2 (default) basic emulation. The emulation includes the following elements: @itemize @minus @item Texas Instruments OMAP310 System-on-chip (ARM 925T core) @item 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 @item On-chip LCD controller @item On-chip Real Time Clock @item Secure Digital card connected to OMAP MMC/SD host @item Three on-chip UARTs @end itemize A Linux 2.6 test image is available on the QEMU web site. More information is available in the QEMU mailing-list archive. @c man begin OPTIONS The following options are specific to the ARM emulation: @table @option @item -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. @end table @c man end @node ColdFire System emulator @section ColdFire System emulator @cindex system emulation (ColdFire) @cindex system emulation (M68K) Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine. The emulator is able to boot a uClinux kernel. The M5208EVB emulation includes the following devices: @itemize @minus @item MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC). @item Three Two on-chip UARTs. @item Fast Ethernet Controller (FEC) @end itemize The AN5206 emulation includes the following devices: @itemize @minus @item MCF5206 ColdFire V2 Microprocessor. @item Two on-chip UARTs. @end itemize @c man begin OPTIONS The following options are specific to the ColdFire emulation: @table @option @item -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. @end table @c man end @node Cris System emulator @section Cris System emulator @cindex system emulation (Cris) TODO @node Microblaze System emulator @section Microblaze System emulator @cindex system emulation (Microblaze) TODO @node SH4 System emulator @section SH4 System emulator @cindex system emulation (SH4) TODO @node Xtensa System emulator @section Xtensa System emulator @cindex system emulation (Xtensa) Two executables cover simulation of both Xtensa endian options, @file{qemu-system-xtensa} and @file{qemu-system-xtensaeb}. Two different machine types are emulated: @itemize @minus @item Xtensa emulator pseudo board "sim" @item Avnet LX60/LX110/LX200 board @end itemize The sim pseudo board emulation provides an environment similar to one provided by the proprietary Tensilica ISS. It supports: @itemize @minus @item A range of Xtensa CPUs, default is the DC232B @item Console and filesystem access via semihosting calls @end itemize The Avnet LX60/LX110/LX200 emulation supports: @itemize @minus @item A range of Xtensa CPUs, default is the DC232B @item 16550 UART @item OpenCores 10/100 Mbps Ethernet MAC @end itemize @c man begin OPTIONS The following options are specific to the Xtensa emulation: @table @option @item -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. @end table @c man end @node QEMU Guest Agent @chapter QEMU Guest Agent invocation @include qemu-ga.texi @node QEMU User space emulator @chapter QEMU User space emulator @menu * Supported Operating Systems :: * Features:: * Linux User space emulator:: * BSD User space emulator :: @end menu @node Supported Operating Systems @section Supported Operating Systems The following OS are supported in user space emulation: @itemize @minus @item Linux (referred as qemu-linux-user) @item BSD (referred as qemu-bsd-user) @end itemize @node Features @section Features QEMU user space emulation has the following notable features: @table @strong @item System call translation: QEMU includes a generic system call translator. This means that the parameters of the system calls can be converted to fix endianness and 32/64-bit mismatches between hosts and targets. IOCTLs can be converted too. @item POSIX signal handling: QEMU can redirect to the running program all signals coming from the host (such as @code{SIGALRM}), as well as synthesize signals from virtual CPU exceptions (for example @code{SIGFPE} when the program executes a division by zero). QEMU relies on the host kernel to emulate most signal system calls, for example to emulate the signal mask. On Linux, QEMU supports both normal and real-time signals. @item Threading: On Linux, QEMU can emulate the @code{clone} syscall and create a real host thread (with a separate virtual CPU) for each emulated thread. Note that not all targets currently emulate atomic operations correctly. x86 and ARM use a global lock in order to preserve their semantics. @end table QEMU was conceived so that ultimately it can emulate itself. Although it is not very useful, it is an important test to show the power of the emulator. @node Linux User space emulator @section Linux User space emulator @menu * Quick Start:: * Wine launch:: * Command line options:: * Other binaries:: @end menu @node Quick Start @subsection 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. @itemize @item On x86, you can just try to launch any process by using the native libraries: @example qemu-i386 -L / /bin/ls @end example @code{-L /} tells that the x86 dynamic linker must be searched with a @file{/} prefix. @item 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): @example qemu-i386 -L / qemu-i386 -L / /bin/ls @end example @item On non x86 CPUs, you need first to download at least an x86 glibc (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that @code{LD_LIBRARY_PATH} is not set: @example unset LD_LIBRARY_PATH @end example Then you can launch the precompiled @file{ls} x86 executable: @example qemu-i386 tests/i386/ls @end example You can look at @file{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 @code{binfmt_misc} module in the Linux kernel. @item The x86 version of QEMU is also included. You can try weird things such as: @example qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \ /usr/local/qemu-i386/bin/ls-i386 @end example @end itemize @node Wine launch @subsection Wine launch @itemize @item 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: @example qemu-i386 /usr/local/qemu-i386/bin/ls-i386 @end example @item Download the binary x86 Wine install (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page). @item Configure Wine on your account. Look at the provided script @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}. @item Then you can try the example @file{putty.exe}: @example qemu-i386 /usr/local/qemu-i386/wine/bin/wine \ /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe @end example @end itemize @node Command line options @subsection Command line options @example @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}...] @end example @table @option @item -h Print the help @item -L path Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386) @item -s size Set the x86 stack size in bytes (default=524288) @item -cpu model Select CPU model (-cpu help for list and additional feature selection) @item -E @var{var}=@var{value} Set environment @var{var} to @var{value}. @item -U @var{var} Remove @var{var} from the environment. @item -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. @item -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. @end table Debug options: @table @option @item -d item1,... Activate logging of the specified items (use '-d help' for a list of log items) @item -p pagesize Act as if the host page size was 'pagesize' bytes @item -g port Wait gdb connection to port @item -singlestep Run the emulation in single step mode. @end table Environment variables: @table @env @item 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. @end table @node Other binaries @subsection Other binaries @cindex user mode (Alpha) @command{qemu-alpha} TODO. @cindex user mode (ARM) @command{qemu-armeb} TODO. @cindex user mode (ARM) @command{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. @cindex user mode (ColdFire) @cindex user mode (M68K) @command{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. @cindex user mode (Cris) @command{qemu-cris} TODO. @cindex user mode (i386) @command{qemu-i386} TODO. @command{qemu-x86_64} TODO. @cindex user mode (Microblaze) @command{qemu-microblaze} TODO. @cindex user mode (MIPS) @command{qemu-mips} TODO. @command{qemu-mipsel} TODO. @cindex user mode (NiosII) @command{qemu-nios2} TODO. @cindex user mode (PowerPC) @command{qemu-ppc64abi32} TODO. @command{qemu-ppc64} TODO. @command{qemu-ppc} TODO. @cindex user mode (SH4) @command{qemu-sh4eb} TODO. @command{qemu-sh4} TODO. @cindex user mode (SPARC) @command{qemu-sparc} can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI). @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI). @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI). @node BSD User space emulator @section BSD User space emulator @menu * BSD Status:: * BSD Quick Start:: * BSD Command line options:: @end menu @node BSD Status @subsection BSD Status @itemize @minus @item target Sparc64 on Sparc64: Some trivial programs work. @end itemize @node BSD Quick Start @subsection Quick Start In order to launch a BSD process, QEMU needs the process executable itself and all the target dynamic libraries used by it. @itemize @item On Sparc64, you can just try to launch any process by using the native libraries: @example qemu-sparc64 /bin/ls @end example @end itemize @node BSD Command line options @subsection Command line options @example @command{qemu-sparc64} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-bsd} @var{type}] @var{program} [@var{arguments}...] @end example @table @option @item -h Print the help @item -L path Set the library root path (default=/) @item -s size Set the stack size in bytes (default=524288) @item -ignore-environment Start with an empty environment. Without this option, the initial environment is a copy of the caller's environment. @item -E @var{var}=@var{value} Set environment @var{var} to @var{value}. @item -U @var{var} Remove @var{var} from the environment. @item -bsd type Set the type of the emulated BSD Operating system. Valid values are FreeBSD, NetBSD and OpenBSD (default). @end table Debug options: @table @option @item -d item1,... Activate logging of the specified items (use '-d help' for a list of log items) @item -p pagesize Act as if the host page size was 'pagesize' bytes @item -singlestep Run the emulation in single step mode. @end table @include qemu-tech.texi @node Deprecated features @appendix Deprecated features In general features are intended to be supported indefinitely once introduced into QEMU. In the event that a feature needs to be removed, it will be listed in this appendix. The feature will remain functional for 2 releases prior to actual removal. Deprecated features may also generate warnings on the console when QEMU starts up, or if activated via a monitor command, however, this is not a mandatory requirement. Prior to the 2.10.0 release there was no official policy on how long features would be deprecated prior to their removal, nor any documented list of which features were deprecated. Thus any features deprecated prior to 2.10.0 will be treated as if they were first deprecated in the 2.10.0 release. What follows is a list of all features currently marked as deprecated. @section System emulator command line arguments @subsection -drive boot=on|off (since 1.3.0) The ``boot=on|off'' option to the ``-drive'' argument is ignored. Applications should use the ``bootindex=N'' parameter to set an absolute ordering between devices instead. @subsection -tdf (since 1.3.0) The ``-tdf'' argument is ignored. The behaviour implemented by this argument is now the default when using the KVM PIT, but can be requested explicitly using ``-global kvm-pit.lost_tick_policy=slew''. @subsection -no-kvm-pit-reinjection (since 1.3.0) The ``-no-kvm-pit-reinjection'' argument is now a synonym for setting ``-global kvm-pit.lost_tick_policy=discard''. @subsection -no-kvm-irqchip (since 1.3.0) The ``-no-kvm-irqchip'' argument is now a synonym for setting ``-machine kernel_irqchip=off''. @subsection -no-kvm-pit (since 1.3.0) The ``-no-kvm-pit'' argument is ignored. It is no longer possible to disable the KVM PIT directly. @subsection -no-kvm (since 1.3.0) The ``-no-kvm'' argument is now a synonym for setting ``-machine accel=tcg''. @subsection -mon default=on (since 2.4.0) The ``default'' option to the ``-mon'' argument is now ignored. When multiple monitors were enabled, it indicated which monitor would receive log messages from the various subsystems. This feature is no longer required as messages are now only sent to the monitor in response to explicitly monitor commands. @subsection -vnc tls (since 2.5.0) The ``-vnc tls'' argument is now a synonym for setting ``-object tls-creds-anon,id=tls0'' combined with ``-vnc tls-creds=tls0' @subsection -vnc x509 (since 2.5.0) The ``-vnc x509=/path/to/certs'' argument is now a synonym for setting ``-object tls-creds-x509,dir=/path/to/certs,id=tls0,verify-peer=no'' combined with ``-vnc tls-creds=tls0' @subsection -vnc x509verify (since 2.5.0) The ``-vnc x509verify=/path/to/certs'' argument is now a synonym for setting ``-object tls-creds-x509,dir=/path/to/certs,id=tls0,verify-peer=yes'' combined with ``-vnc tls-creds=tls0' @subsection -tftp (since 2.6.0) The ``-tftp /some/dir'' argument is now a synonym for setting the ``-netdev user,tftp=/some/dir' argument. The new syntax allows different settings to be provided per NIC. @subsection -bootp (since 2.6.0) The ``-bootp /some/file'' argument is now a synonym for setting the ``-netdev user,bootp=/some/file' argument. The new syntax allows different settings to be provided per NIC. @subsection -redir (since 2.6.0) The ``-redir ARGS'' argument is now a synonym for setting the ``-netdev user,hostfwd=ARGS'' argument instead. The new syntax allows different settings to be provided per NIC. @subsection -smb (since 2.6.0) The ``-smb /some/dir'' argument is now a synonym for setting the ``-netdev user,smb=/some/dir'' argument instead. The new syntax allows different settings to be provided per NIC. @subsection -net channel (since 2.6.0) The ``--net channel,ARGS'' argument is now a synonym for setting the ``-netdev user,guestfwd=ARGS'' argument instead. @subsection -net vlan (since 2.9.0) The ``-net vlan=NN'' argument is partially replaced with the new ``-netdev'' argument. The remaining use cases will no longer be directly supported in QEMU. @subsection -drive if=scsi (since 2.9.0) The ``-drive if=scsi'' argument is replaced by the the ``-device BUS-TYPE'' argument combined with ``-drive if=none''. @subsection -net dump (since 2.10.0) The ``--net dump'' argument is now replaced with the ``-object filter-dump'' argument which works in combination with the modern ``-netdev`` backends instead. @subsection -hdachs (since 2.10.0) The ``-hdachs'' argument is now a synonym for setting the ``cyls'', ``heads'', ``secs'', and ``trans'' properties on the ``ide-hd'' device using the ``-device'' argument. The new syntax allows different settings to be provided per disk. @subsection -usbdevice (since 2.10.0) The ``-usbdevice DEV'' argument is now a synonym for setting the ``-device usb-DEV'' argument instead. The deprecated syntax would automatically enable USB support on the machine type. If using the new syntax, USB support must be explicitly enabled via the ``-machine usb=on'' argument. @section qemu-img command line arguments @subsection convert -s (since 2.0.0) The ``convert -s snapshot_id_or_name'' argument is obsoleted by the ``convert -l snapshot_param'' argument instead. @section System emulator human monitor commands @subsection host_net_add (since 2.10.0) The ``host_net_add'' command is replaced by the ``netdev_add'' command. @subsection host_net_remove (since 2.10.0) The ``host_net_remove'' command is replaced by the ``netdev_del'' command. @subsection usb_add (since 2.10.0) The ``usb_add'' command is replaced by the ``device_add'' command. @subsection usb_del (since 2.10.0) The ``usb_del'' command is replaced by the ``device_del'' command. @section System emulator devices @subsection ivshmem (since 2.6.0) The ``ivshmem'' device type is replaced by either the ``ivshmem-plain'' or ``ivshmem-doorbell`` device types. @subsection spapr-pci-vfio-host-bridge (since 2.6.0) The ``spapr-pci-vfio-host-bridge'' device type is replaced by the ``spapr-pci-host-bridge'' device type. @node License @appendix License QEMU is a trademark of Fabrice Bellard. QEMU is released under the @url{https://www.gnu.org/licenses/gpl-2.0.txt,GNU General Public License}, version 2. Parts of QEMU have specific licenses, see file @url{http://git.qemu.org/?p=qemu.git;a=blob_plain;f=LICENSE,LICENSE}. @node Index @appendix Index @menu * Concept Index:: * Function Index:: * Keystroke Index:: * Program Index:: * Data Type Index:: * Variable Index:: @end menu @node Concept Index @section Concept Index This is the main index. Should we combine all keywords in one index? TODO @printindex cp @node Function Index @section Function Index This index could be used for command line options and monitor functions. @printindex fn @node Keystroke Index @section Keystroke Index This is a list of all keystrokes which have a special function in system emulation. @printindex ky @node Program Index @section Program Index @printindex pg @node Data Type Index @section Data Type Index This index could be used for qdev device names and options. @printindex tp @node Variable Index @section Variable Index @printindex vr @bye