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authorwanchao-xu <wanchao.xu@samsung.com>2024-01-09 14:28:24 +0800
committerwanchao-xu <wanchao.xu@samsung.com>2024-01-09 18:52:53 +0800
commit937800223c6e5964718875a1e5033ca62ef44875 (patch)
treecb4df5e00d5ddd5a9c255d9de123f4bf42961716 /qemu-doc.texi
parent0889ee8339e51dfdf78c39a8f15b6e5fe5ab49d5 (diff)
downloadqemu-arm-static-937800223c6e5964718875a1e5033ca62ef44875.tar.gz
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Upgrade version to 4.2.1
Change-Id: I38f1ed0c4da7315a6f8be766b3fc09531cb36313 Signed-off-by: wanchao-xu <wanchao.xu@samsung.com>
Diffstat (limited to 'qemu-doc.texi')
-rw-r--r--qemu-doc.texi2026
1 files changed, 990 insertions, 1036 deletions
diff --git a/qemu-doc.texi b/qemu-doc.texi
index 185dd47a0..3ddf5c0a6 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -1,15 +1,19 @@
\input texinfo @c -*- texinfo -*-
@c %**start of header
@setfilename qemu-doc.info
+@include version.texi
@documentlanguage en
@documentencoding UTF-8
-@settitle QEMU Emulator User Documentation
+@settitle QEMU version @value{VERSION} User Documentation
@exampleindent 0
@paragraphindent 0
@c %**end of header
+@set qemu_system qemu-system-x86_64
+@set qemu_system_x86 qemu-system-x86_64
+
@ifinfo
@direntry
* QEMU: (qemu-doc). The QEMU Emulator User Documentation.
@@ -19,7 +23,7 @@
@iftex
@titlepage
@sp 7
-@center @titlefont{QEMU Emulator}
+@center @titlefont{QEMU version @value{VERSION}}
@sp 1
@center @titlefont{User Documentation}
@sp 3
@@ -32,11 +36,16 @@
@menu
* Introduction::
-* Installation::
* QEMU PC System emulator::
* QEMU System emulator for non PC targets::
+* QEMU Guest Agent::
* QEMU User space emulator::
-* compilation:: Compilation from the sources
+* System requirements::
+* Security::
+* Implementation notes::
+* Deprecated features::
+* Recently removed features::
+* Supported build platforms::
* License::
* Index::
@end menu
@@ -57,98 +66,69 @@
QEMU is a FAST! processor emulator using dynamic translation to
achieve good emulation speed.
+@cindex operating modes
QEMU has two operating modes:
@itemize
-@cindex operating modes
-
-@item
@cindex system emulation
-Full system emulation. In this mode, QEMU emulates a full system (for
+@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.
-@item
@cindex user mode emulation
-User mode emulation. In this mode, QEMU can launch
+@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
+launch the Wine Windows API emulator (@url{https://www.winehq.org}) or
to ease cross-compilation and cross-debugging.
@end itemize
-QEMU can run without a host kernel driver and yet gives acceptable
-performance.
+QEMU has the following features:
-For system emulation, the following hardware targets are supported:
@itemize
-@cindex emulated target systems
-@cindex supported target systems
-@item PC (x86 or x86_64 processor)
-@item ISA PC (old style PC without PCI bus)
-@item PREP (PowerPC processor)
-@item G3 Beige PowerMac (PowerPC processor)
-@item Mac99 PowerMac (PowerPC processor, in progress)
-@item Sun4m/Sun4c/Sun4d (32-bit Sparc processor)
-@item Sun4u/Sun4v (64-bit Sparc processor, in progress)
-@item Malta board (32-bit and 64-bit MIPS processors)
-@item MIPS Magnum (64-bit MIPS processor)
-@item ARM Integrator/CP (ARM)
-@item ARM Versatile baseboard (ARM)
-@item ARM RealView Emulation/Platform baseboard (ARM)
-@item Spitz, Akita, Borzoi, Terrier and Tosa PDAs (PXA270 processor)
-@item Luminary Micro LM3S811EVB (ARM Cortex-M3)
-@item Luminary Micro LM3S6965EVB (ARM Cortex-M3)
-@item Freescale MCF5208EVB (ColdFire V2).
-@item Arnewsh MCF5206 evaluation board (ColdFire V2).
-@item Palm Tungsten|E PDA (OMAP310 processor)
-@item N800 and N810 tablets (OMAP2420 processor)
-@item MusicPal (MV88W8618 ARM processor)
-@item Gumstix "Connex" and "Verdex" motherboards (PXA255/270).
-@item Siemens SX1 smartphone (OMAP310 processor)
-@item AXIS-Devboard88 (CRISv32 ETRAX-FS).
-@item Petalogix Spartan 3aDSP1800 MMU ref design (MicroBlaze).
-@item Avnet LX60/LX110/LX200 boards (Xtensa)
-@end 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.
-@cindex supported user mode targets
-For user emulation, x86 (32 and 64 bit), PowerPC (32 and 64 bit),
-ARM, MIPS (32 bit only), Sparc (32 and 64 bit),
-Alpha, ColdFire(m68k), CRISv32 and MicroBlaze CPUs are supported.
+@item It is portable to several operating systems (GNU/Linux, *BSD, Mac OS X,
+Windows) and architectures.
-@node Installation
-@chapter Installation
+@item It performs accurate software emulation of the FPU.
+@end itemize
-If you want to compile QEMU yourself, see @ref{compilation}.
+QEMU user mode emulation has the following features:
+@itemize
+@item Generic Linux system call converter, including most ioctls.
-@menu
-* install_linux:: Linux
-* install_windows:: Windows
-* install_mac:: Macintosh
-@end menu
+@item clone() emulation using native CPU clone() to use Linux scheduler for threads.
-@node install_linux
-@section Linux
-@cindex installation (Linux)
+@item Accurate signal handling by remapping host signals to target signals.
+@end itemize
-If a precompiled package is available for your distribution - you just
-have to install it. Otherwise, see @ref{compilation}.
+QEMU full system emulation has the following features:
+@itemize
+@item
+QEMU uses a full software MMU for maximum portability.
-@node install_windows
-@section Windows
-@cindex installation (Windows)
+@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.
-Download the experimental binary installer at
-@url{http://www.free.oszoo.org/@/download.html}.
-TODO (no longer available)
+@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).
-@node install_mac
-@section Mac OS X
+@item
+Symmetric multiprocessing (SMP) support. Currently, an in-kernel
+accelerator is required to use more than one host CPU for emulation.
+
+@end itemize
-Download the experimental binary installer at
-@url{http://www.free.oszoo.org/@/download.html}.
-TODO (no longer available)
@node QEMU PC System emulator
@chapter QEMU PC System emulator
@@ -158,14 +138,17 @@ TODO (no longer available)
* pcsys_introduction:: Introduction
* pcsys_quickstart:: Quick Start
* sec_invocation:: Invocation
-* pcsys_keys:: Keys
+* pcsys_keys:: Keys in the graphical frontends
+* mux_keys:: Keys in the character backend multiplexer
* pcsys_monitor:: QEMU Monitor
+* cpu_models:: CPU models
* 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
+* network_tls:: TLS setup for network services
* gdb_usage:: GDB usage
* pcsys_os_specific:: Target OS specific information
@end menu
@@ -195,6 +178,8 @@ 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
@@ -209,7 +194,7 @@ Gravis Ultrasound GF1 sound card
@item
CS4231A compatible sound card
@item
-PCI UHCI USB controller and a virtual USB hub.
+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.
@@ -226,12 +211,12 @@ 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
+@value{qemu_system_x86} dos.img -soundhw gus -parallel none
@end example
Alternatively:
@example
-qemu-system-i386 dos.img -device gus,irq=5
+@value{qemu_system_x86} dos.img -device gus,irq=5
@end example
Or some other unclaimed IRQ.
@@ -244,10 +229,11 @@ CS4231A is the chip used in Windows Sound System and GUSMAX products
@section Quick Start
@cindex quick start
-Download and uncompress the linux image (@file{linux.img}) and type:
+Download and uncompress a hard disk image with Linux installed (e.g.
+@file{linux.img}) and type:
@example
-qemu-system-i386 linux.img
+@value{qemu_system} linux.img
@end example
Linux should boot and give you a prompt.
@@ -257,7 +243,7 @@ Linux should boot and give you a prompt.
@example
@c man begin SYNOPSIS
-usage: qemu-system-i386 [options] [@var{disk_image}]
+@command{@value{qemu_system}} [@var{options}] [@var{disk_image}]
@c man end
@end example
@@ -269,8 +255,231 @@ targets do not need a disk image.
@c man end
+@subsection Device URL Syntax
+@c TODO merge this with section Disk Images
+
+@c man begin NOTES
+
+In addition to using normal file images for the emulated storage devices,
+QEMU can also use networked resources such as iSCSI devices. These are
+specified using a special URL syntax.
+
+@table @option
+@item iSCSI
+iSCSI support allows QEMU to access iSCSI resources directly and use as
+images for the guest storage. Both disk and cdrom images are supported.
+
+Syntax for specifying iSCSI LUNs is
+``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
+
+By default qemu will use the iSCSI initiator-name
+'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
+line or a configuration file.
+
+Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
+stalled requests and force a reestablishment of the session. The timeout
+is specified in seconds. The default is 0 which means no timeout. Libiscsi
+1.15.0 or greater is required for this feature.
+
+Example (without authentication):
+@example
+@value{qemu_system} -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
+ -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
+ -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
+@end example
+
+Example (CHAP username/password via URL):
+@example
+@value{qemu_system} -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
+@end example
+
+Example (CHAP username/password via environment variables):
+@example
+LIBISCSI_CHAP_USERNAME="user" \
+LIBISCSI_CHAP_PASSWORD="password" \
+@value{qemu_system} -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
+@end example
+
+@item NBD
+QEMU supports NBD (Network Block Devices) both using TCP protocol as well
+as Unix Domain Sockets. With TCP, the default port is 10809.
+
+Syntax for specifying a NBD device using TCP, in preferred URI form:
+``nbd://<server-ip>[:<port>]/[<export>]''
+
+Syntax for specifying a NBD device using Unix Domain Sockets; remember
+that '?' is a shell glob character and may need quoting:
+``nbd+unix:///[<export>]?socket=<domain-socket>''
+
+Older syntax that is also recognized:
+``nbd:<server-ip>:<port>[:exportname=<export>]''
+
+Syntax for specifying a NBD device using Unix Domain Sockets
+``nbd:unix:<domain-socket>[:exportname=<export>]''
+
+Example for TCP
+@example
+@value{qemu_system} --drive file=nbd:192.0.2.1:30000
+@end example
+
+Example for Unix Domain Sockets
+@example
+@value{qemu_system} --drive file=nbd:unix:/tmp/nbd-socket
+@end example
+
+@item SSH
+QEMU supports SSH (Secure Shell) access to remote disks.
+
+Examples:
+@example
+@value{qemu_system} -drive file=ssh://user@@host/path/to/disk.img
+@value{qemu_system} -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
+@end example
+
+Currently authentication must be done using ssh-agent. Other
+authentication methods may be supported in future.
+
+@item Sheepdog
+Sheepdog is a distributed storage system for QEMU.
+QEMU supports using either local sheepdog devices or remote networked
+devices.
+
+Syntax for specifying a sheepdog device
+@example
+sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
+@end example
+
+Example
+@example
+@value{qemu_system} --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
+@end example
+
+See also @url{https://sheepdog.github.io/sheepdog/}.
+
+@item GlusterFS
+GlusterFS is a user space distributed file system.
+QEMU supports the use of GlusterFS volumes for hosting VM disk images using
+TCP, Unix Domain Sockets and RDMA transport protocols.
+
+Syntax for specifying a VM disk image on GlusterFS volume is
+@example
+
+URI:
+gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]
+
+JSON:
+'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
+@ "server":[@{"type":"tcp","host":"...","port":"..."@},
+@ @{"type":"unix","socket":"..."@}]@}@}'
+@end example
+
+
+Example
+@example
+URI:
+@value{qemu_system} --drive file=gluster://192.0.2.1/testvol/a.img,
+@ file.debug=9,file.logfile=/var/log/qemu-gluster.log
+
+JSON:
+@value{qemu_system} '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"@}]@}@}'
+@value{qemu_system} -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
+
+See also @url{http://www.gluster.org}.
+
+@item HTTP/HTTPS/FTP/FTPS
+QEMU supports read-only access to files accessed over http(s) and ftp(s).
+
+Syntax using a single filename:
+@example
+<protocol>://[<username>[:<password>]@@]<host>/<path>
+@end example
+
+where:
+@table @option
+@item protocol
+'http', 'https', 'ftp', or 'ftps'.
+
+@item username
+Optional username for authentication to the remote server.
+
+@item password
+Optional password for authentication to the remote server.
+
+@item host
+Address of the remote server.
+
+@item path
+Path on the remote server, including any query string.
+@end table
+
+The following options are also supported:
+@table @option
+@item url
+The full URL when passing options to the driver explicitly.
+
+@item readahead
+The amount of data to read ahead with each range request to the remote server.
+This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
+does not have a suffix, it will be assumed to be in bytes. The value must be a
+multiple of 512 bytes. It defaults to 256k.
+
+@item sslverify
+Whether to verify the remote server's certificate when connecting over SSL. It
+can have the value 'on' or 'off'. It defaults to 'on'.
+
+@item cookie
+Send this cookie (it can also be a list of cookies separated by ';') with
+each outgoing request. Only supported when using protocols such as HTTP
+which support cookies, otherwise ignored.
+
+@item timeout
+Set the timeout in seconds of the CURL connection. This timeout is the time
+that CURL waits for a response from the remote server to get the size of the
+image to be downloaded. If not set, the default timeout of 5 seconds is used.
+@end table
+
+Note that when passing options to qemu explicitly, @option{driver} is the value
+of <protocol>.
+
+Example: boot from a remote Fedora 20 live ISO image
+@example
+@value{qemu_system_x86} --drive media=cdrom,file=https://archives.fedoraproject.org/pub/archive/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
+
+@value{qemu_system_x86} --drive media=cdrom,file.driver=http,file.url=http://archives.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
+@end example
+
+Example: boot from a remote Fedora 20 cloud image using a local overlay for
+writes, copy-on-read, and a readahead of 64k
+@example
+qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"http",, "file.url":"http://archives.fedoraproject.org/pub/archive/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2
+
+@value{qemu_system_x86} -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
+@end example
+
+Example: boot from an image stored on a VMware vSphere server with a self-signed
+certificate using a local overlay for writes, a readahead of 64k and a timeout
+of 10 seconds.
+@example
+qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@}' /tmp/test.qcow2
+
+@value{qemu_system_x86} -drive file=/tmp/test.qcow2
+@end example
+
+@end table
+
+@c man end
+
@node pcsys_keys
-@section Keys
+@section Keys in the graphical frontends
@c man begin OPTIONS
@@ -320,15 +529,23 @@ Toggle mouse and keyboard grab.
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.
-@kindex Ctrl-a h
-During emulation, if you are using the @option{-nographic} option, use
-@key{Ctrl-a h} to get terminal commands:
+@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
-@item Ctrl-a ?
-@kindex Ctrl-a ?
Print this help
@item Ctrl-a x
@kindex Ctrl-a x
@@ -344,10 +561,11 @@ Toggle console timestamps
Send break (magic sysrq in Linux)
@item Ctrl-a c
@kindex Ctrl-a c
-Switch between console and monitor
+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 a
-Send Ctrl-a
+@kindex Ctrl-a Ctrl-a
+Send the escape character to the frontend
@end table
@c man end
@@ -391,20 +609,25 @@ 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 cpu_models
+@section CPU models
+
+@include docs/qemu-cpu-models.texi
+
@node disk_images
@section Disk Images
-Since version 0.6.1, QEMU supports many disk image formats, including
-growable disk images (their size increase as non empty sectors are
-written), compressed and encrypted disk images. Version 0.8.3 added
-the new qcow2 disk image format which is essential to support VM
-snapshots.
+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
@@ -420,6 +643,8 @@ snapshots.
* disk_images_iscsi:: iSCSI LUNs
* disk_images_gluster:: GlusterFS disk images
* disk_images_ssh:: Secure Shell (ssh) disk images
+* disk_images_nvme:: NVMe userspace driver
+* disk_image_locking:: Disk image file locking
@end menu
@node disk_images_quickstart
@@ -505,606 +730,17 @@ state is not saved or restored properly (in particular USB).
@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.
-
-@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), optional AES encryption, 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 (this is the default).
-@code{compat=1.1} enables image format extensions that only QEMU 1.1 and
-newer understand. 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
-If this option is set to @code{on}, the image is encrypted.
-
-Encryption uses the AES format which is very secure (128 bit keys). Use
-a long password (16 characters) to get maximum protection.
-
-@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: off, metadata). An image with preallocated
-metadata is initially larger but can improve performance when the image needs
-to grow.
-
-@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.
-
-@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
-If this option is set to @code{on}, the image is encrypted.
-@end table
-
-@item cow
-User Mode Linux Copy On Write image format. It is supported only for
-compatibility with previous versions.
-Supported options:
-@table @code
-@item backing_file
-File name of a base image (see @option{create} subcommand)
-@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 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
-@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 or
-@file{/dev/fd0} for the floppy.
-
-@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).
-@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 to share 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[:<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 an user space distributed file system.
-
-You can boot from the GlusterFS disk image with the command:
-@example
-qemu-system-x86_64 -drive file=gluster[+@var{transport}]://[@var{server}[:@var{port}]]/@var{volname}/@var{image}[?socket=...]
-@end example
-
-@var{gluster} is the protocol.
-
-@var{transport} specifies the transport type used to connect to gluster
-management daemon (glusterd). Valid transport types are
-tcp, unix and rdma. If a transport type isn't specified, then tcp
-type is assumed.
-
-@var{server} specifies the server where the volume file specification for
-the given volume resides. This can be either hostname, ipv4 address
-or ipv6 address. ipv6 address needs to be within square brackets [ ].
-If transport type is unix, then @var{server} field should not be specifed.
-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, QEMU will send 0 which will make gluster to use the
-default port. If the transport type is unix, then @var{port} should not be
-specified.
-
-@var{volname} is the name of the gluster volume which contains the disk image.
-
-@var{image} is the path to the actual disk image that resides on gluster volume.
-
-You can create a GlusterFS disk image with the command:
-@example
-qemu-img create gluster://@var{server}/@var{volname}/@var{image} @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
-@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.
+@include docs/qemu-block-drivers.texi
@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).
+QEMU can simulate several network cards (e.g. PCI or ISA cards on the PC
+target) and can connect them to a network backend on the host or an emulated
+hub. The various host network backends can either be used to connect the NIC of
+the guest to a real network (e.g. by using a TAP devices or the non-privileged
+user mode network stack), or to other guest instances running in another QEMU
+process (e.g. by using the socket host network backend).
@subsection Using TAP network interfaces
@@ -1129,7 +765,7 @@ TAP network interfaces.
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/}.
+so download OpenVPN from : @url{https://openvpn.net/}.
@subsection Using the user mode network stack
@@ -1140,7 +776,7 @@ network). The virtual network configuration is the following:
@example
- QEMU VLAN <------> Firewall/DHCP server <-----> Internet
+ guest (10.0.2.15) <------> Firewall/DHCP server <-----> Internet
| (10.0.2.2)
|
----> DNS server (10.0.2.3)
@@ -1157,35 +793,59 @@ 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 @code{ping} is not supported reliably to the internet as it
-would require root privileges. It means you can only ping the local
-router (10.0.2.2).
+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{-redir} option, TCP or UDP connections can be
-redirected from the host to the guest. It allows for example to
-redirect X11, telnet or SSH connections.
+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 Hubs
-@subsection Connecting VLANs between QEMU instances
+QEMU can simulate several hubs. A hub can be thought of 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). You can connect
+guest NICs or host network backends to such a hub using the @option{-netdev
+hubport} or @option{-nic hubport} options. The legacy @option{-net} option
+also connects the given device to the emulated hub with ID 0 (i.e. the default
+hub) unless you specify a netdev with @option{-net nic,netdev=xxx} here.
-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.
+@subsection Connecting emulated networks between QEMU instances
+
+Using the @option{-netdev socket} (or @option{-nic socket} or
+@option{-net socket}) option, it is possible to create emulated
+networks that span several QEMU instances.
+See the description of the @option{-netdev socket} option in the
+@ref{sec_invocation,,Invocation chapter} to have a basic example.
@node pcsys_other_devs
@section Other Devices
@subsection Inter-VM Shared Memory device
-With KVM enabled on a Linux host, a shared memory device is available. Guests
-map a POSIX shared memory region into the guest as a PCI device that enables
-zero-copy communication to the application level of the guests. The basic
-syntax is:
+On Linux hosts, a shared memory device is available. The basic syntax
+is:
+
+@example
+@value{qemu_system_x86} -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
-qemu-system-i386 -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>]
+-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
@@ -1195,28 +855,41 @@ is qemu.git/contrib/ivshmem-server. An example syntax when using the shared
memory server is:
@example
-qemu-system-i386 -device ivshmem,size=<size in format accepted by -m>[,chardev=<id>]
- [,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master]
-qemu-system-i386 -chardev socket,path=<path>,id=<id>
+# 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
+@value{qemu_system_x86} -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 example code). Since receiving the shared
-memory region from the server is asynchronous, there is a (small) chance the
-guest may boot before the shared memory is attached. To allow an application
-to ensure shared memory is attached, the VM ID register will return -1 (an
-invalid VM ID) until the memory is attached. Once the shared memory is
-attached, the VM ID will return the guest's valid VM ID. With these semantics,
-the guest application can check to ensure the shared memory is attached to the
-guest before proceeding.
-
-The @option{role} argument can be set to either master or peer and will affect
-how the shared memory is migrated. With @option{role=master}, the guest will
-copy the shared memory on migration to the destination host. With
-@option{role=peer}, the guest will not be able to migrate with the device attached.
-With the @option{peer} case, the device should be detached and then reattached
-after migration using the PCI hotplug support.
+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
+@value{qemu_system_x86} -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
@@ -1227,22 +900,18 @@ kernel testing.
The syntax is:
@example
-qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
+@value{qemu_system} -kernel bzImage -hda rootdisk.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 \
+@value{qemu_system} -kernel bzImage -hda rootdisk.img \
-append "root=/dev/hda console=ttyS0" -nographic
@end example
@@ -1252,10 +921,10 @@ monitor (@pxref{pcsys_keys}).
@node pcsys_usb
@section USB emulation
-QEMU emulates a PCI UHCI USB controller. You can virtually plug
-virtual USB devices or real host USB devices (experimental, works only
-on Linux hosts). QEMU will automatically create and connect virtual USB hubs
-as necessary to connect multiple USB devices.
+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::
@@ -1264,59 +933,70 @@ as necessary to connect multiple USB devices.
@node usb_devices
@subsection Connecting USB devices
-USB devices can be connected with the @option{-usbdevice} commandline option
-or the @code{usb_add} monitor command. Available devices are:
+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 mouse
+@item usb-mouse
Virtual Mouse. This will override the PS/2 mouse emulation when activated.
-@item tablet
+@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 disk:@var{file}
-Mass storage device based on @var{file} (@pxref{disk_images})
-@item host:@var{bus.addr}
-Pass through the host device identified by @var{bus.addr}
-(Linux only)
-@item host:@var{vendor_id:product_id}
-Pass through the host device identified by @var{vendor_id:product_id}
-(Linux only)
-@item wacom-tablet
+@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{https://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{https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/usb-storage.txt,usb-storage.txt}
+for details here, too
+@item usb-mtp,rootdir=@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 keyboard
+@item usb-kbd
Standard USB keyboard. Will override the PS/2 keyboard (if present).
-@item serial:[vendorid=@var{vendor_id}][,product_id=@var{product_id}]:@var{dev}
+@item usb-serial,chardev=@var{id}
Serial converter. This emulates an FTDI FT232BM chip connected to host character
-device @var{dev}. The available character devices are the same as for the
-@code{-serial} option. The @code{vendorid} and @code{productid} options can be
-used to override the default 0403:6001. For instance,
-@example
-usb_add serial:productid=FA00:tcp:192.168.0.2:4444
-@end example
-will connect to tcp port 4444 of ip 192.168.0.2, and plug that to the virtual
-serial converter, faking a Matrix Orbital LCD Display (USB ID 0403:FA00).
-@item braille
+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.
-@item net:@var{options}
-Network adapter that supports CDC ethernet and RNDIS protocols. @var{options}
-specifies NIC options as with @code{-net nic,}@var{options} (see description).
+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 [...OPTIONS...] -net user,vlan=0 -usbdevice net:vlan=0
-@end example
-Currently this cannot be used in machines that support PCI NICs.
-@item bt[:@var{hci-type}]
-Bluetooth dongle whose type is specified in the same format as with
+@value{qemu_system} [...] -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
-qemu-system-i386 [...OPTIONS...] -usbdevice bt:hci,vlan=3 -bt device:keyboard,vlan=3
+@command{@value{qemu_system}} [...@var{OPTIONS}...] @option{-usbdevice} bt:hci,vlan=3 @option{-bt} device:keyboard,vlan=3
@end example
@end table
@@ -1355,11 +1035,11 @@ hubs, it won't work).
@item Add the device in QEMU by using:
@example
-usb_add host:1234:5678
+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{-usbdevice} to do the same.
+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.
@@ -1383,7 +1063,6 @@ considerations depending on the deployment scenarios.
* vnc_sec_certificate_pw::
* vnc_sec_sasl::
* vnc_sec_certificate_sasl::
-* vnc_generate_cert::
* vnc_setup_sasl::
@end menu
@node vnc_sec_none
@@ -1394,7 +1073,7 @@ 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
+@value{qemu_system} [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
@end example
This ensures that only users on local box with read/write access to that
@@ -1417,7 +1096,7 @@ 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
+@value{qemu_system} [...OPTIONS...] -vnc :1,password -monitor stdio
(qemu) change vnc password
Password: ********
(qemu)
@@ -1434,7 +1113,9 @@ 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
+@value{qemu_system} [...OPTIONS...] \
+ -object tls-creds-x509,id=tls0,dir=/etc/pki/qemu,endpoint=server,verify-peer=no \
+ -vnc :1,tls-creds=tls0 -monitor stdio
@end example
In the above example @code{/etc/pki/qemu} should contain at least three files,
@@ -1449,10 +1130,14 @@ only be readable by the user owning it.
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.
+in an environment with a private internal certificate authority. It uses the
+same syntax as previously, but with @code{verify-peer} set to @code{yes}
+instead.
@example
-qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
+@value{qemu_system} [...OPTIONS...] \
+ -object tls-creds-x509,id=tls0,dir=/etc/pki/qemu,endpoint=server,verify-peer=yes \
+ -vnc :1,tls-creds=tls0 -monitor stdio
@end example
@@ -1463,7 +1148,9 @@ 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
+@value{qemu_system} [...OPTIONS...] \
+ -object tls-creds-x509,id=tls0,dir=/etc/pki/qemu,endpoint=server,verify-peer=yes \
+ -vnc :1,tls-creds=tls0,password -monitor stdio
(qemu) change vnc password
Password: ********
(qemu)
@@ -1486,7 +1173,7 @@ 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
+@value{qemu_system} [...OPTIONS...] -vnc :1,sasl -monitor stdio
@end example
@node vnc_sec_certificate_sasl
@@ -1500,28 +1187,111 @@ 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
+@value{qemu_system} [...OPTIONS...] \
+ -object tls-creds-x509,id=tls0,dir=/etc/pki/qemu,endpoint=server,verify-peer=yes \
+ -vnc :1,tls-creds=tls0,sasl -monitor stdio
+@end example
+
+@node vnc_setup_sasl
+
+@subsection Configuring SASL mechanisms
+
+The following documentation assumes use of the Cyrus SASL implementation on a
+Linux host, but the principles should apply to any other SASL implementation
+or host. 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 file.
+
+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 @code{saslpasswd2} program can be used to populate the @code{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 network_tls
+@section TLS setup for network services
+
+Almost all network services in QEMU have the ability to use TLS for
+session data encryption, along with x509 certificates for simple
+client authentication. What follows is a description of how to
+generate certificates suitable for usage with QEMU, and applies to
+the VNC server, character devices with the TCP backend, NBD server
+and client, and migration server and client.
+
+At a high level, QEMU requires certificates and private keys to be
+provided in PEM format. Aside from the core fields, the certificates
+should include various extension data sets, including v3 basic
+constraints data, key purpose, key usage and subject alt name.
-@node vnc_generate_cert
-@subsection Generating certificates for VNC
+The GnuTLS package includes a command called @code{certtool} which can
+be used to easily generate certificates and keys in the required format
+with expected data present. Alternatively a certificate management
+service may be used.
-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}.
+At a minimum it is necessary to setup a certificate authority, and
+issue certificates to each server. If using x509 certificates for
+authentication, then each client will also need to be issued a
+certificate.
+
+Assuming that the QEMU network services will only ever be exposed to
+clients on a private intranet, there is no need to use a commercial
+certificate authority to create certificates. A self-signed CA is
+sufficient, and in fact likely to be more secure since it removes
+the ability of malicious 3rd parties to trick the CA into mis-issuing
+certs for impersonating your services. The only likely exception
+where a commercial CA might be desirable is if enabling the VNC
+websockets server and exposing it directly to remote browser clients.
+In such a case it might be useful to use a commercial CA to avoid
+needing to install custom CA certs in the web browsers.
+
+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::
+* tls_generate_ca::
+* tls_generate_server::
+* tls_generate_client::
+* tls_creds_setup::
+* tls_psk::
@end menu
-@node vnc_generate_ca
-@subsubsection Setup the Certificate Authority
+@node tls_generate_ca
+@subsection 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
@@ -1532,11 +1302,10 @@ issued with it is lost.
# 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.
-
+To generate a self-signed certificate requires one core piece of information,
+the name of the organization. A template file @code{ca.info} should be
+populated with the desired data to avoid having to deal with interactive
+prompts from certtool:
@example
# cat > ca.info <<EOF
cn = Name of your organization
@@ -1549,115 +1318,260 @@ EOF
--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.
+The @code{ca} keyword in the template sets the v3 basic constraints extension
+to indicate this certificate is for a CA, while @code{cert_signing_key} sets
+the key usage extension to indicate this will be used for signing other keys.
+The generated @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 anywhere except the host responsible for issuing
+certificates.
-@node vnc_generate_server
-@subsubsection Issuing server certificates
+@node tls_generate_server
+@subsection 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
+The core pieces of information for a server certificate are the hostnames and/or IP
+addresses that will be used by clients when connecting. The hostname / IP address
+that the client specifies when connecting will be validated against the hostname(s)
+and IP address(es) recorded in the server certificate, and if no match is found
+the client will close the connection.
+
+Thus it is recommended that the server certificate include both the fully qualified
+and unqualified hostnames. If the server will have permanently assigned IP address(es),
+and clients are likely to use them when connecting, they may also be included in the
+certificate. Both IPv4 and IPv6 addresses are supported. Historically certificates
+only included 1 hostname in the @code{CN} field, however, usage of this field for
+validation is now deprecated. Instead modern TLS clients will validate against the
+Subject Alt Name extension data, which allows for multiple entries. In the future
+usage of the @code{CN} field may be discontinued entirely, so providing SAN
+extension data is strongly recommended.
+
+On the host holding the CA, create template files containing the information
+for each server, and use it to issue server certificates.
+
+@example
+# cat > server-hostNNN.info <<EOF
organization = Name of your organization
-cn = server.foo.example.com
+cn = hostNNN.foo.example.com
+dns_name = hostNNN
+dns_name = hostNNN.foo.example.com
+ip_address = 10.0.1.87
+ip_address = 192.8.0.92
+ip_address = 2620:0:cafe::87
+ip_address = 2001:24::92
tls_www_server
encryption_key
signing_key
EOF
-# certtool --generate-privkey > server-key.pem
+# certtool --generate-privkey > server-hostNNN-key.pem
# certtool --generate-certificate \
--load-ca-certificate ca-cert.pem \
--load-ca-privkey ca-key.pem \
- --load-privkey server server-key.pem \
- --template server.info \
- --outfile server-cert.pem
+ --load-privkey server-hostNNN-key.pem \
+ --template server-hostNNN.info \
+ --outfile server-hostNNN-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.
+The @code{dns_name} and @code{ip_address} fields in the template are setting
+the subject alt name extension data. The @code{tls_www_server} keyword is the
+key purpose extension to indicate this certificate is intended for usage in
+a web server. Although QEMU network services are not in fact HTTP servers
+(except for VNC websockets), setting this key purpose is still recommended.
+The @code{encryption_key} and @code{signing_key} keyword is the key usage
+extension to indicate this certificate is intended for usage in the data
+session.
+
+The @code{server-hostNNN-key.pem} and @code{server-hostNNN-cert.pem} files
+should now be securely copied to the server for which they were generated,
+and renamed to @code{server-key.pem} and @code{server-cert.pem} when added
+to the @code{/etc/pki/qemu} directory on the target host. The @code{server-key.pem}
+file is security sensitive and should be kept protected with file mode 0600
+to prevent disclosure.
+
+@node tls_generate_client
+@subsection Issuing client certificates
+
+The QEMU x509 TLS credential setup defaults to enabling client verification
+using certificates, providing a simple authentication mechanism. If this
+default is used, each client also needs to be issued a certificate. The client
+certificate contains enough metadata to uniquely identify the client with the
+scope of the certificate authority. The client certificate would typically
+include fields for organization, state, city, building, etc.
-@node vnc_generate_client
-@subsubsection Issuing client certificates
+Once again on the host holding the CA, create template files containing the
+information for each client, and use it to issue 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
+# cat > client-hostNNN.info <<EOF
country = GB
state = London
-locality = London
-organiazation = Name of your organization
-cn = client.foo.example.com
+locality = City Of London
+organization = Name of your organization
+cn = hostNNN.foo.example.com
tls_www_client
encryption_key
signing_key
EOF
-# certtool --generate-privkey > client-key.pem
+# certtool --generate-privkey > client-hostNNN-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
+ --load-privkey client-hostNNN-key.pem \
+ --template client-hostNNN.info \
+ --outfile client-hostNNN-cert.pem
+@end example
+
+The subject alt name extension data is not required for clients, so the
+the @code{dns_name} and @code{ip_address} fields are not included.
+The @code{tls_www_client} keyword is the key purpose extension to indicate
+this certificate is intended for usage in a web client. Although QEMU
+network clients are not in fact HTTP clients, setting this key purpose is
+still recommended. The @code{encryption_key} and @code{signing_key} keyword
+is the key usage extension to indicate this certificate is intended for
+usage in the data session.
+
+The @code{client-hostNNN-key.pem} and @code{client-hostNNN-cert.pem} files
+should now be securely copied to the client for which they were generated,
+and renamed to @code{client-key.pem} and @code{client-cert.pem} when added
+to the @code{/etc/pki/qemu} directory on the target host. The @code{client-key.pem}
+file is security sensitive and should be kept protected with file mode 0600
+to prevent disclosure.
+
+If a single host is going to be using TLS in both a client and server
+role, it is possible to create a single certificate to cover both roles.
+This would be quite common for the migration and NBD services, where a
+QEMU process will be started by accepting a TLS protected incoming migration,
+and later itself be migrated out to another host. To generate a single
+certificate, simply include the template data from both the client and server
+instructions in one.
+
+@example
+# cat > both-hostNNN.info <<EOF
+country = GB
+state = London
+locality = City Of London
+organization = Name of your organization
+cn = hostNNN.foo.example.com
+dns_name = hostNNN
+dns_name = hostNNN.foo.example.com
+ip_address = 10.0.1.87
+ip_address = 192.8.0.92
+ip_address = 2620:0:cafe::87
+ip_address = 2001:24::92
+tls_www_server
+tls_www_client
+encryption_key
+signing_key
+EOF
+# certtool --generate-privkey > both-hostNNN-key.pem
+# certtool --generate-certificate \
+ --load-ca-certificate ca-cert.pem \
+ --load-ca-privkey ca-key.pem \
+ --load-privkey both-hostNNN-key.pem \
+ --template both-hostNNN.info \
+ --outfile both-hostNNN-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.
+When copying the PEM files to the target host, save them twice,
+once as @code{server-cert.pem} and @code{server-key.pem}, and
+again as @code{client-cert.pem} and @code{client-key.pem}.
+@node tls_creds_setup
+@subsection TLS x509 credential configuration
-@node vnc_setup_sasl
+QEMU has a standard mechanism for loading x509 credentials that will be
+used for network services and clients. It requires specifying the
+@code{tls-creds-x509} class name to the @code{--object} command line
+argument for the system emulators. Each set of credentials loaded should
+be given a unique string identifier via the @code{id} parameter. A single
+set of TLS credentials can be used for multiple network backends, so VNC,
+migration, NBD, character devices can all share the same credentials. Note,
+however, that credentials for use in a client endpoint must be loaded
+separately from those used in a server endpoint.
-@subsection Configuring SASL mechanisms
+When specifying the object, the @code{dir} parameters specifies which
+directory contains the credential files. This directory is expected to
+contain files with the names mentioned previously, @code{ca-cert.pem},
+@code{server-key.pem}, @code{server-cert.pem}, @code{client-key.pem}
+and @code{client-cert.pem} as appropriate. It is also possible to
+include a set of pre-generated Diffie-Hellman (DH) parameters in a file
+@code{dh-params.pem}, which can be created using the
+@code{certtool --generate-dh-params} command. If omitted, QEMU will
+dynamically generate DH parameters when loading the credentials.
-The following documentation assumes use of the Cyrus SASL implementation on a
-Linux host, but the principals should apply to any other SASL impl. When SASL
-is enabled, the mechanism configuration will be loaded from system default
-SASL service config /etc/sasl2/qemu.conf. If running QEMU as an
-unprivileged user, an environment variable SASL_CONF_PATH can be used
-to make it search alternate locations for the service config.
+The @code{endpoint} parameter indicates whether the credentials will
+be used for a network client or server, and determines which PEM
+files are loaded.
+
+The @code{verify} parameter determines whether x509 certificate
+validation should be performed. This defaults to enabled, meaning
+clients will always validate the server hostname against the
+certificate subject alt name fields and/or CN field. It also
+means that servers will request that clients provide a certificate
+and validate them. Verification should never be turned off for
+client endpoints, however, it may be turned off for server endpoints
+if an alternative mechanism is used to authenticate clients. For
+example, the VNC server can use SASL to authenticate clients
+instead.
-The default configuration might contain
+To load server credentials with client certificate validation
+enabled
@example
-mech_list: digest-md5
-sasldb_path: /etc/qemu/passwd.db
+@value{qemu_system} -object tls-creds-x509,id=tls0,dir=/etc/pki/qemu,endpoint=server
+@end example
+
+while to load client credentials use
+
+@example
+@value{qemu_system} -object tls-creds-x509,id=tls0,dir=/etc/pki/qemu,endpoint=client
+@end example
+
+Network services which support TLS will all have a @code{tls-creds}
+parameter which expects the ID of the TLS credentials object. For
+example with VNC:
+
+@example
+@value{qemu_system} -vnc 0.0.0.0:0,tls-creds=tls0
@end example
-This says to use the 'Digest MD5' mechanism, which is similar to the HTTP
-Digest-MD5 mechanism. The list of valid usernames & passwords is maintained
-in the /etc/qemu/passwd.db file, and can be updated using the saslpasswd2
-command. While this mechanism is easy to configure and use, it is not
-considered secure by modern standards, so only suitable for developers /
-ad-hoc testing.
+@node tls_psk
+@subsection TLS Pre-Shared Keys (PSK)
+
+Instead of using certificates, you may also use TLS Pre-Shared Keys
+(TLS-PSK). This can be simpler to set up than certificates but is
+less scalable.
-A more serious deployment might use Kerberos, which is done with the 'gssapi'
-mechanism
+Use the GnuTLS @code{psktool} program to generate a @code{keys.psk}
+file containing one or more usernames and random keys:
@example
-mech_list: gssapi
-keytab: /etc/qemu/krb5.tab
+mkdir -m 0700 /tmp/keys
+psktool -u rich -p /tmp/keys/keys.psk
+@end example
+
+TLS-enabled servers such as qemu-nbd can use this directory like so:
+
+@example
+qemu-nbd \
+ -t -x / \
+ --object tls-creds-psk,id=tls0,endpoint=server,dir=/tmp/keys \
+ --tls-creds tls0 \
+ image.qcow2
@end example
-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 connecting from a qemu-based client you must specify the
+directory containing @code{keys.psk} and an optional @var{username}
+(defaults to ``qemu''):
-Other configurations will be left as an exercise for the reader. It should
-be noted that only Digest-MD5 and GSSAPI provides a SSF layer for data
-encryption. For all other mechanisms, VNC should always be configured to
-use TLS and x509 certificates to protect security credentials from snooping.
+@example
+qemu-img info \
+ --object tls-creds-psk,id=tls0,dir=/tmp/keys,username=rich,endpoint=client \
+ --image-opts \
+ file.driver=nbd,file.host=localhost,file.port=10809,file.tls-creds=tls0,file.export=/
+@end example
@node gdb_usage
@section GDB usage
@@ -1668,8 +1582,7 @@ QEMU has a primitive support to work with gdb, so that you can do
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"
+@value{qemu_system} -s -kernel bzImage -hda rootdisk.img -append "root=/dev/hda"
Connected to host network interface: tun0
Waiting gdb connection on port 1234
@end example
@@ -1703,7 +1616,7 @@ Use @code{set architecture i8086} to dump 16 bit code. Then use
Advanced debugging options:
-The default single stepping behavior is step with the IRQs and timer service routines off. It is set this way because when gdb executes a single step it expects to advance beyond the current instruction. With the IRQs and and timer service routines on, a single step might jump into the one of the interrupt or exception vectors instead of executing the current instruction. This means you may hit the same breakpoint a number of times before executing the instruction gdb wants to have executed. Because there are rare circumstances where you want to single step into an interrupt vector the behavior can be controlled from GDB. There are three commands you can query and set the single step behavior:
+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
@@ -1773,8 +1686,8 @@ resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
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://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
-problem. Note that no such tool is needed for NT, 2000 or XP.
+@url{https://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
@@ -1799,7 +1712,8 @@ 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{-smb}.
+See @ref{sec_invocation} about the help of the option
+@option{'-netdev user,smb=...'}.
@subsubsection Windows XP security problem
@@ -1821,9 +1735,9 @@ vvfat block device ("-hdb fat:directory_which_holds_the_SP").
@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://www.vmware.com/software/dosidle210.zip} to solve this
-problem.
+it takes host CPU cycles even when idle. You can install the utility from
+@url{https://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
@@ -1893,7 +1807,7 @@ PC compatible keyboard and mouse.
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/}
+Since version 0.9.1, QEMU uses OpenBIOS @url{https://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.
@@ -1906,7 +1820,7 @@ The following options are specific to the PowerPC emulation:
@item -g @var{W}x@var{H}[x@var{DEPTH}]
-Set the initial VGA graphic mode. The default is 800x600x15.
+Set the initial VGA graphic mode. The default is 800x600x32.
@item -prom-env @var{string}
@@ -1964,7 +1878,7 @@ QEMU emulates the following sun4m peripherals:
@item
IOMMU
@item
-TCX Frame buffer
+TCX or cgthree Frame buffer
@item
Lance (Am7990) Ethernet
@item
@@ -1985,13 +1899,13 @@ 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
+@url{https://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
firmware implementation. The goal is to implement a 100% IEEE
1275-1994 (referred to as Open Firmware) compliant firmware.
A sample Linux 2.6 series kernel and ram disk image are available on
the QEMU web site. There are still issues with NetBSD and OpenBSD, but
-some kernel versions work. Please note that currently Solaris kernels
+most kernel versions work. Please note that currently older Solaris kernels
don't work probably due to interface issues between OpenBIOS and
Solaris.
@@ -2003,8 +1917,9 @@ The following options are specific to the Sparc32 emulation:
@item -g @var{W}x@var{H}x[x@var{DEPTH}]
-Set the initial TCX graphic mode. The default is 1024x768x8, currently
-the only other possible mode is 1024x768x24.
+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}
@@ -2029,8 +1944,19 @@ Set the emulated machine type. Default is SS-5.
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 emulator is not usable for anything yet, but
-it can launch some kernels.
+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:
@@ -2065,7 +1991,7 @@ Set OpenBIOS variables in NVRAM, for example:
qemu-system-sparc64 -prom-env 'auto-boot?=false'
@end example
-@item -M [sun4u|sun4v|Niagara]
+@item -M [sun4u|sun4v|niagara]
Set the emulated machine type. The default is sun4u.
@@ -2077,6 +2003,10 @@ Set the emulated machine type. The default is sun4u.
@section MIPS System emulator
@cindex system emulation (MIPS)
+@menu
+* nanoMIPS System emulator ::
+@end menu
+
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}.
@@ -2127,6 +2057,15 @@ Malta FPGA serial device
Cirrus (default) or any other PCI VGA graphics card
@end itemize
+The Boston board emulation supports the following devices:
+
+@itemize @minus
+@item
+Xilinx FPGA, which includes a PCIe root port and an UART
+@item
+Intel EG20T PCH connects the I/O peripherals, but only the SATA bus is emulated
+@end itemize
+
The ACER Pica emulation supports:
@itemize @minus
@@ -2140,6 +2079,34 @@ PC Keyboard
IDE controller
@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
+
+The Fulong 2E emulation supports:
+
+@itemize @minus
+@item
+Loongson 2E CPU
+@item
+Bonito64 system controller as North Bridge
+@item
+VT82C686 chipset as South Bridge
+@item
+RTL8139D as a network card chipset
+@end itemize
+
The mipssim pseudo board emulation provides an environment similar
to what the proprietary MIPS emulator uses for running Linux.
It supports:
@@ -2153,21 +2120,31 @@ PC style serial port
MIPSnet network emulation
@end itemize
-The MIPS Magnum R4000 emulation supports:
+@node nanoMIPS System emulator
+@subsection nanoMIPS System emulator
+@cindex system emulation (nanoMIPS)
+
+Executable @file{qemu-system-mipsel} also covers simulation of
+32-bit nanoMIPS system in little endian mode:
@itemize @minus
@item
-MIPS R4000 CPU
-@item
-PC-style IRQ controller
-@item
-PC Keyboard
-@item
-SCSI controller
-@item
-G364 framebuffer
+nanoMIPS I7200 CPU
@end itemize
+Example of @file{qemu-system-mipsel} usage for nanoMIPS is shown below:
+
+Download @code{<disk_image_file>} from @url{https://mipsdistros.mips.com/LinuxDistro/nanomips/buildroot/index.html}.
+
+Download @code{<kernel_image_file>} from @url{https://mipsdistros.mips.com/LinuxDistro/nanomips/kernels/v4.15.18-432-gb2eb9a8b07a1-20180627102142/index.html}.
+
+Start system emulation of Malta board with nanoMIPS I7200 CPU:
+@example
+qemu-system-mipsel -cpu I7200 -kernel @code{<kernel_image_file>} \
+ -M malta -serial stdio -m @code{<memory_size>} -hda @code{<disk_image_file>} \
+ -append "mem=256m@@0x0 rw console=ttyS0 vga=cirrus vesa=0x111 root=/dev/sda"
+@end example
+
@node ARM System emulator
@section ARM System emulator
@@ -2433,6 +2410,8 @@ 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)
@@ -2477,6 +2456,8 @@ 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)
@@ -2548,11 +2529,15 @@ 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 User space emulator
@chapter QEMU User space emulator
@menu
* Supported Operating Systems ::
+* Features::
* Linux User space emulator::
* BSD User space emulator ::
@end menu
@@ -2569,6 +2554,39 @@ Linux (referred as qemu-linux-user)
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
@@ -2663,7 +2681,7 @@ qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
@subsection Command line options
@example
-usage: qemu-i386 [-h] [-d] [-L path] [-s size] [-cpu model] [-g port] [-B offset] [-R size] program [arguments...]
+@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
@@ -2746,8 +2764,20 @@ The binary format is detected automatically.
@command{qemu-microblaze} TODO.
@cindex user mode (MIPS)
-@command{qemu-mips} TODO.
-@command{qemu-mipsel} TODO.
+@command{qemu-mips} executes 32-bit big endian MIPS binaries (MIPS O32 ABI).
+
+@command{qemu-mipsel} executes 32-bit little endian MIPS binaries (MIPS O32 ABI).
+
+@command{qemu-mips64} executes 64-bit big endian MIPS binaries (MIPS N64 ABI).
+
+@command{qemu-mips64el} executes 64-bit little endian MIPS binaries (MIPS N64 ABI).
+
+@command{qemu-mipsn32} executes 32-bit big endian MIPS binaries (MIPS N32 ABI).
+
+@command{qemu-mipsn32el} executes 32-bit little endian MIPS binaries (MIPS N32 ABI).
+
+@cindex user mode (NiosII)
+@command{qemu-nios2} TODO.
@cindex user mode (PowerPC)
@command{qemu-ppc64abi32} TODO.
@@ -2805,7 +2835,7 @@ qemu-sparc64 /bin/ls
@subsection Command line options
@example
-usage: qemu-sparc64 [-h] [-d] [-L path] [-s size] [-bsd type] program [arguments...]
+@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
@@ -2838,177 +2868,101 @@ Act as if the host page size was 'pagesize' bytes
Run the emulation in single step mode.
@end table
-@node compilation
-@chapter Compilation from the sources
-
-@menu
-* Linux/Unix::
-* Windows::
-* Cross compilation for Windows with Linux::
-* Mac OS X::
-* Make targets::
-@end menu
-
-@node Linux/Unix
-@section Linux/Unix
-
-@subsection Compilation
-
-First you must decompress the sources:
-@example
-cd /tmp
-tar zxvf qemu-x.y.z.tar.gz
-cd qemu-x.y.z
-@end example
-
-Then you configure QEMU and build it (usually no options are needed):
-@example
-./configure
-make
-@end example
-
-Then type as root user:
-@example
-make install
-@end example
-to install QEMU in @file{/usr/local}.
-
-@node Windows
-@section Windows
-
-@itemize
-@item Install the current versions of MSYS and MinGW from
-@url{http://www.mingw.org/}. You can find detailed installation
-instructions in the download section and the FAQ.
-
-@item Download
-the MinGW development library of SDL 1.2.x
-(@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
-@url{http://www.libsdl.org}. Unpack it in a temporary place and
-edit the @file{sdl-config} script so that it gives the
-correct SDL directory when invoked.
-
-@item Install the MinGW version of zlib and make sure
-@file{zlib.h} and @file{libz.dll.a} are in
-MinGW's default header and linker search paths.
-
-@item Extract the current version of QEMU.
+@node System requirements
+@chapter System requirements
-@item Start the MSYS shell (file @file{msys.bat}).
-
-@item Change to the QEMU directory. Launch @file{./configure} and
-@file{make}. If you have problems using SDL, verify that
-@file{sdl-config} can be launched from the MSYS command line.
-
-@item You can install QEMU in @file{Program Files/QEMU} by typing
-@file{make install}. Don't forget to copy @file{SDL.dll} in
-@file{Program Files/QEMU}.
-
-@end itemize
+@section KVM kernel module
-@node Cross compilation for Windows with Linux
-@section Cross compilation for Windows with Linux
+On x86_64 hosts, the default set of CPU features enabled by the KVM accelerator
+require the host to be running Linux v4.5 or newer.
-@itemize
-@item
-Install the MinGW cross compilation tools available at
-@url{http://www.mingw.org/}.
+The OpteronG[345] CPU models require KVM support for RDTSCP, which was
+added with Linux 4.5 which is supported by the major distros. And even
+if RHEL7 has kernel 3.10, KVM there has the required functionality there
+to make it close to a 4.5 or newer kernel.
-@item Download
-the MinGW development library of SDL 1.2.x
-(@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
-@url{http://www.libsdl.org}. Unpack it in a temporary place and
-edit the @file{sdl-config} script so that it gives the
-correct SDL directory when invoked. Set up the @code{PATH} environment
-variable so that @file{sdl-config} can be launched by
-the QEMU configuration script.
+@include docs/security.texi
-@item Install the MinGW version of zlib and make sure
-@file{zlib.h} and @file{libz.dll.a} are in
-MinGW's default header and linker search paths.
+@include qemu-tech.texi
-@item
-Configure QEMU for Windows cross compilation:
-@example
-PATH=/usr/i686-pc-mingw32/sys-root/mingw/bin:$PATH ./configure --cross-prefix='i686-pc-mingw32-'
-@end example
-The example assumes @file{sdl-config} is installed under @file{/usr/i686-pc-mingw32/sys-root/mingw/bin} and
-MinGW cross compilation tools have names like @file{i686-pc-mingw32-gcc} and @file{i686-pc-mingw32-strip}.
-We set the @code{PATH} environment variable to ensure the MinGW version of @file{sdl-config} is used and
-use --cross-prefix to specify the name of the cross compiler.
-You can also use --prefix to set the Win32 install path which defaults to @file{c:/Program Files/QEMU}.
+@include qemu-deprecated.texi
-Under Fedora Linux, you can run:
-@example
-yum -y install mingw32-gcc mingw32-SDL mingw32-zlib
-@end example
-to get a suitable cross compilation environment.
+@node Supported build platforms
+@appendix Supported build platforms
-@item You can install QEMU in the installation directory by typing
-@code{make install}. Don't forget to copy @file{SDL.dll} and @file{zlib1.dll} into the
-installation directory.
+QEMU aims to support building and executing on multiple host OS platforms.
+This appendix outlines which platforms are the major build targets. These
+platforms are used as the basis for deciding upon the minimum required
+versions of 3rd party software QEMU depends on. The supported platforms
+are the targets for automated testing performed by the project when patches
+are submitted for review, and tested before and after merge.
-@end itemize
+If a platform is not listed here, it does not imply that QEMU won't work.
+If an unlisted platform has comparable software versions to a listed platform,
+there is every expectation that it will work. Bug reports are welcome for
+problems encountered on unlisted platforms unless they are clearly older
+vintage than what is described here.
-Wine can be used to launch the resulting qemu-system-i386.exe
-and all other qemu-system-@var{target}.exe compiled for Win32.
+Note that when considering software versions shipped in distros as support
+targets, QEMU considers only the version number, and assumes the features in
+that distro match the upstream release with the same version. In other words,
+if a distro backports extra features to the software in their distro, QEMU
+upstream code will not add explicit support for those backports, unless the
+feature is auto-detectable in a manner that works for the upstream releases
+too.
-@node Mac OS X
-@section Mac OS X
+The Repology site @url{https://repology.org} is a useful resource to identify
+currently shipped versions of software in various operating systems, though
+it does not cover all distros listed below.
-The Mac OS X patches are not fully merged in QEMU, so you should look
-at the QEMU mailing list archive to have all the necessary
-information.
+@section Linux OS
-@node Make targets
-@section Make targets
+For distributions with frequent, short-lifetime releases, the project will
+aim to support all versions that are not end of life by their respective
+vendors. For the purposes of identifying supported software versions, the
+project will look at Fedora, Ubuntu, and openSUSE distros. Other short-
+lifetime distros will be assumed to ship similar software versions.
-@table @code
+For distributions with long-lifetime releases, the project will aim to support
+the most recent major version at all times. Support for the previous major
+version will be dropped 2 years after the new major version is released. For
+the purposes of identifying supported software versions, the project will look
+at RHEL, Debian, Ubuntu LTS, and SLES distros. Other long-lifetime distros will
+be assumed to ship similar software versions.
-@item make
-@item make all
-Make everything which is typically needed.
+@section Windows
-@item install
-TODO
+The project supports building with current versions of the MinGW toolchain,
+hosted on Linux.
-@item install-doc
-TODO
+@section macOS
-@item make clean
-Remove most files which were built during make.
+The project supports building with the two most recent versions of macOS, with
+the current homebrew package set available.
-@item make distclean
-Remove everything which was built during make.
+@section FreeBSD
-@item make dvi
-@item make html
-@item make info
-@item make pdf
-Create documentation in dvi, html, info or pdf format.
+The project aims to support the all the versions which are not end of life.
-@item make cscope
-TODO
+@section NetBSD
-@item make defconfig
-(Re-)create some build configuration files.
-User made changes will be overwritten.
+The project aims to support the most recent major version at all times. Support
+for the previous major version will be dropped 2 years after the new major
+version is released.
-@item tar
-@item tarbin
-TODO
+@section OpenBSD
-@end table
+The project aims to support the all the versions which are not end of life.
@node License
@appendix License
QEMU is a trademark of Fabrice Bellard.
-QEMU is released under the GNU General Public License (TODO: add link).
-Parts of QEMU have specific licenses, see file LICENSE.
-
-TODO (refer to file LICENSE, include it, include the GPL?)
+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{https://git.qemu.org/?p=qemu.git;a=blob_plain;f=LICENSE,LICENSE}.
@node Index
@appendix Index