Supported build platforms — QEMU documentation

# 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 is a useful resource to identify currently shipped versions of software in various operating systems, though it does not cover all distros listed below.

## Supported host architectures

Those hosts are officially supported, with various accelerators:

> CPU Architecture | Accelerators
> --- | ---
> Arm | kvm (64 bit only), tcg, xen
> MIPS (little endian only) | kvm, tcg
> PPC | kvm, tcg
> RISC-V | kvm, tcg
> s390x | kvm, tcg
> SPARC | tcg
> x86 | hvf (64 bit only), kvm, nvmm, tcg, whpx (64 bit only), xen

Other host architectures are not supported. It is possible to build QEMU system emulation on an unsupported host architecture using the configure `--enable-tcg-interpreter` option to enable the TCI support, but note that this is very slow and is not recommended for normal use. QEMU user emulation requires host-specific support for signal handling, therefore TCI won’t help on unsupported host architectures.

Non-supported architectures may be removed in the future following the deprecation process.

## Linux OS, macOS, FreeBSD, NetBSD, OpenBSD

The project aims to support the most recent major version at all times for up to five years after its initial release. Support for the previous major version will be dropped 2 years after the new major version is released or when the vendor itself drops support, whichever comes first. In this context, third-party efforts to extend the lifetime of a distro are not considered, even when they are endorsed by the vendor (eg. Debian LTS); the same is true of repositories that contain packages backported from later releases (e.g. Debian backports). Within each major release, only the most recent minor release is considered.

For the purposes of identifying supported software versions available on Linux, the project will look at CentOS, Debian, Fedora, openSUSE, RHEL, SLES and Ubuntu LTS. Other distros will be assumed to ship similar software versions.

For FreeBSD and OpenBSD, decisions will be made based on the contents of the respective ports repository, while NetBSD will use the pkgsrc repository.

For macOS, Homebrew will be used, although MacPorts is expected to carry similar versions.

Some build dependencies may follow less conservative rules:

Python runtime

  Distributions with long-term support often provide multiple versions of the Python runtime. While QEMU will initially aim to support the distribution’s default runtime, it may later increase its minimum version to any newer python that is available as an option from the vendor. In this case, it will be necessary to use the `--python` command line option of the `configure` script to point QEMU to a supported version of the Python runtime.

  As of QEMU 8.2.0, the minimum supported version of Python is 3.7.

Python build dependencies

  Some of QEMU’s build dependencies are written in Python. Usually these are only packaged by distributions for the default Python runtime. If QEMU bumps its minimum Python version and a non-default runtime is required, it may be necessary to fetch python modules from the Python Package Index (PyPI) via `pip`, in order to build QEMU.

Optional build dependencies

  Build components whose absence does not affect the ability to build QEMU may not be available in distros, or may be too old for QEMU’s requirements. Many of these, such as the Avocado testing framework or various linters, are written in Python and therefore can also be installed using `pip`. Cross compilers are another example of optional build-time dependency; in this case it is possible to download them from repositories such as EPEL, to use container-based cross compilation using `docker` or `podman`, or to use pre-built binaries distributed with QEMU.

## Windows

The project aims to support the two most recent versions of Windows that are still supported by the vendor. The minimum Windows API that is currently targeted is “Windows 8”, so theoretically the QEMU binaries can still be run on older versions of Windows, too. However, such old versions of Windows are not tested anymore, so it is recommended to use one of the latest versions of Windows instead.

The project supports building QEMU with current versions of the MinGW toolchain, either hosted on Linux (Debian/Fedora) or via MSYS2 on Windows. A more recent Windows version is always preferred as it is less likely to have problems with building via MSYS2. The building process of QEMU involves some Python scripts that call os.symlink() which needs special attention for the build process to successfully complete. On newer versions of Windows 10, unprivileged accounts can create symlinks if Developer Mode is enabled. When Developer Mode is not available/enabled, the SeCreateSymbolicLinkPrivilege privilege is required, or the process must be run as an administrator.