* QEMU User space emulator::
* Implementation notes::
* Deprecated features::
+* Supported build platforms::
* License::
* Index::
@end menu
@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
@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)
connections can be redirected from the host to the guest. It allows for
example to redirect X11, telnet or SSH connections.
-@subsection Connecting VLANs between QEMU instances
+@subsection Hubs
+
+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.
+
+@subsection Connecting emulated networks between QEMU instances
-Using the @option{-net socket} option, it is possible to make VLANs
-that span several QEMU instances. See @ref{sec_invocation} to have a
-basic example.
+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
@section System emulator command line arguments
-@subsection -no-kvm-pit-reinjection (since 1.3.0)
-
-The ``-no-kvm-pit-reinjection'' argument is now a
-synonym for setting ``-global kvm-pit.lost_tick_policy=discard''.
-
-@subsection -no-kvm-irqchip (since 1.3.0)
-
-The ``-no-kvm-irqchip'' argument is now a synonym for
-setting ``-machine kernel_irqchip=off''.
-
@subsection -no-kvm (since 1.3.0)
The ``-no-kvm'' argument is now a synonym for setting
(for embedded NICs). The new syntax allows different settings to be
provided per NIC.
-@subsection -net vlan (since 2.9.0)
-
-The ``-net vlan=NN'' argument was mostly used to attach separate
-network backends to different virtual NICs. This is the default
-behavior for ``-netdev'' and ``-nic''. You can connect multiple
-``-netdev'' and ``-nic'' devices to the same network using the
-"hubport" network backend, created with ``-netdev hubport,hubid=NN,...''
-and ``-nic hubport,hubid=NN''.
-
@subsection -drive cyls=...,heads=...,secs=...,trans=... (since 2.10.0)
The drive geometry arguments are replaced by the the geometry arguments
The @code{-startdate} option has been replaced by @code{-rtc base=@var{date}}.
+@subsection -virtioconsole (since 3.0.0)
+
+Option @option{-virtioconsole} has been replaced by
+@option{-device virtconsole}.
+
+@subsection -clock (since 3.0.0)
+
+The @code{-clock} option is ignored since QEMU version 1.7.0. There is no
+replacement since it is not needed anymore.
+
@section qemu-img command line arguments
@subsection convert -s (since 2.0.0)
The ``query-cpus'' command is replaced by the ``query-cpus-fast'' command.
-@subsection query-cpus-fast "arch" output member (since 2.13.0)
+@subsection query-cpus-fast "arch" output member (since 3.0.0)
The ``arch'' output member of the ``query-cpus-fast'' command is
replaced by the ``target'' output member.
In order to prevent QEMU from automatically opening an image's backing
chain, use ``"backing": null'' instead.
+@node Supported build platforms
+@appendix Supported build platforms
+
+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.
+
+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.
+
+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.
+
+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.
+
+@section Linux OS
+
+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.
+
+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.
+
+@section Windows
+
+The project supports building with current versions of the MinGW toolchain,
+hosted on Linux.
+
+@section macOS
+
+The project supports building with the two most recent versions of macOS, with
+the current homebrew package set available.
+
+@section FreeBSD
+
+The project aims to support the all the versions which are not end of life.
+
+@section NetBSD
+
+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.
+
+@section OpenBSD
+
+The project aims to support the all the versions which are not end of life.
+
@node License
@appendix License
projects / mirror_qemu.git / blobdiff