qemu/docs/about/build-platforms.rst

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docs/system: convert Texinfo documentation to rST Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-02-28 18:36:05 +03:00
.. _Supported-build-platforms:
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
docs/system: convert Texinfo documentation to rST Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-02-28 18:36:05 +03:00
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:
.. list-table::
:header-rows: 1
* - 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
:ref:`deprecation process<Deprecated features>`.
Linux OS, macOS, FreeBSD, NetBSD, OpenBSD
-----------------------------------------
docs/system: convert Texinfo documentation to rST Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-02-28 18:36:05 +03:00
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.
docs/system: convert Texinfo documentation to rST Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-02-28 18:36:05 +03:00
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.
docs/system: convert Texinfo documentation to rST Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-02-28 18:36:05 +03:00
For FreeBSD and OpenBSD, decisions will be made based on the contents of the
respective ports repository, while NetBSD will use the pkgsrc repository.
docs/system: convert Texinfo documentation to rST Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-02-28 18:36:05 +03:00
For macOS, `Homebrew`_ will be used, although `MacPorts`_ is expected to carry
similar versions.
docs/system: convert Texinfo documentation to rST Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-02-28 18:36:05 +03:00
docs: build-platforms: refine requirements on Python build dependencies Historically, the critical dependency for both building and running QEMU has been the distro packages. Because QEMU is written in C and C's package management has been tied to distros (at least if you do not want to bundle libraries with the binary, otherwise I suppose you could use something like conda or wrapdb), C dependencies of QEMU would target the version that is shipped in relatively old but still commonly used distros. For non-C libraries, however, the situation is different, as these languages have their own package management tool (cpan, pip, gem, npm, and so on). For some of these languages, the amount of dependencies for even a simple program can easily balloon to the point that many distros have given up on packaging non-C code. For this reason, it has become increasingly normal for developers to download dependencies into a self-contained local environment, instead of relying on distro packages. Fortunately, this affects QEMU only at build time, as qemu.git does not package non-C artifacts such as the qemu.qmp package; but still, as we make more use of Python, we experience a clash between a support policy that is written for the C world, and dependencies (both direct and indirect) that increasingly do not care for the distro versions and are quick at moving past Python runtime versions that are declared end-of-life. For example, Python 3.6 has been EOL'd since December 2021 and Meson 0.62 (released the following March) already dropped support for it. Yet, Python 3.6 is the default version of the Python runtime for RHEL/CentOS 8 and SLE 15, respectively the penultimate and the most recent version of two distros that QEMU would like to support. (It is also the version used by Ubuntu 18.04, but QEMU stopped supporting it in April 2022). There are good reasons to move forward with the deprecation of Python 3.6 in QEMU as well: completing the configure->meson switch (which requires Meson 0.63), and making the QAPI generator fully typed (which requires newer versions of not just mypy but also Python, due to PEP563). Fortunately, these long-term support distros do include newer versions of the Python runtime. However, these more recent runtimes only come with a very small subset of the Python packages that the distro includes. Because most dependencies are optional tests (avocado, mypy, flake8) and Meson is bundled with QEMU, the most noticeably missing package is Sphinx (and the readthedocs theme). There are four possibilities: * we change the support policy and stop supporting CentOS 8 and SLE 15; not a good idea since CentOS 8 is not an unreasonable distro for us to want to continue to support * we keep supporting Python 3.6 until CentOS 8 and SLE 15 stop being supported. This is a possibility---but we may want to revise the support policy anyway because SLE 16 has not even been released, so this would mean delaying those desirable reasons for perhaps three years; * we support Python 3.6 just for building documentation, i.e. we are careful not to use Python 3.7+ features in our Sphinx extensions but are free to use them elsewhere. Besides being more complicated to understand for developers, this can be quite limiting; parts of the QAPI generator run at sphinx-build time, which would exclude one of the areas which would benefit from a newer version of the runtime; * we only support Python 3.7+, which means CentOS 8 CI and users have to either install Sphinx from pip or disable documentation. This proposed update to the support policy chooses the last of these possibilities. It does by modifying three aspects of the support policy: * it introduces different support periods for *native* vs. *non-native* dependencies. Non-native dependencies are currently Python ones only, and for simplicity the policy only mentions Python; however, the concept generalizes to other languages with a well-known upstream package manager, that users of older distributions can fetch dependencies from; * it opens up the possibility of taking non-native dependencies from their own package index instead of using the version in the distribution. The wording right now is specific to dependencies that are only required at build time. In the future we may have to refine it if, for example, parts of QEMU will be written in Rust; in that case, crates would be handled in a similar way to submodules and vendored in the release tarballs. * it mentions specifically that optional build dependencies are excluded from the platform policy. Tools such as mypy don't affect the ability to build QEMU and move fast enough that distros cannot standardize on a single version of them (for example RHEL9 does not package them at all, nor does it run them at rpmbuild time). In other cases, such as cross compilers, we have alternatives. Right now, non-native dependencies have to be download manually by running "pip" before "configure". In the future, it will be desirable for configure to set up a virtual environment and download them in the same way that it populates git submodules (but, in this case, without vendoring them in the release tarballs). Just like with submodules, this would make things easier for people that can afford accessing the network in their build environment; the option to populate the build environment manually would remain for people whose build machines lack network access. The change to the support policy neither requires nor forbids this future change. [Thanks to Daniel P. Berrangé, Peter Maydell and others for discussions that were copied or summarized in the above commit message] Cc: Markus Armbruster <armbru@redhat.com> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: John Snow <jsnow@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-02-17 15:09:56 +03:00
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.
Python: Drop support for Python 3.6 Python 3.6 was EOL 2021-12-31. Newer versions of upstream libraries have begun dropping support for this version and it is becoming more cumbersome to support. Avocado-framework and qemu.qmp each have their own reasons for wanting to drop Python 3.6, but won't until QEMU does. Versions of Python available in our supported build platforms as of today, with optional versions available in parentheses: openSUSE Leap 15.4: 3.6.15 (3.9.10, 3.10.2) CentOS Stream 8: 3.6.8 (3.8.13, 3.9.16) CentOS Stream 9: 3.9.13 Fedora 36: 3.10 Fedora 37: 3.11 Debian 11: 3.9.2 Alpine 3.14, 3.15: 3.9.16 Alpine 3.16, 3.17: 3.10.10 Ubuntu 20.04 LTS: 3.8.10 Ubuntu 22.04 LTS: 3.10.4 NetBSD 9.3: 3.9.13* FreeBSD 12.4: 3.9.16 FreeBSD 13.1: 3.9.16 OpenBSD 7.2: 3.9.16 Note: Our VM tests install 3.9 explicitly for FreeBSD and 3.10 for NetBSD; the default for "python" or "python3" in FreeBSD is 3.9.16. NetBSD does not appear to have a default meta-package, but offers several options, the lowest of which is 3.7.15. "python39" appears to be a pre-requisite to one of the other packages we request in tests/vm/netbsd. pip, ensurepip and other Python essentials are currently only available for Python 3.10 for NetBSD. CentOS and OpenSUSE support parallel installation of multiple Python interpreters, and binaries in /usr/bin will always use Python 3.6. However, the newly introduced support for virtual environments ensures that all build steps that execute QEMU Python code use a single interpreter. Since it is safe to under our supported platform policy, bump our minimum supported version of Python to 3.7. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20230511035435.734312-24-jsnow@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-11 06:54:31 +03:00
As of QEMU |version|, the minimum supported version of Python is 3.7.
docs: build-platforms: refine requirements on Python build dependencies Historically, the critical dependency for both building and running QEMU has been the distro packages. Because QEMU is written in C and C's package management has been tied to distros (at least if you do not want to bundle libraries with the binary, otherwise I suppose you could use something like conda or wrapdb), C dependencies of QEMU would target the version that is shipped in relatively old but still commonly used distros. For non-C libraries, however, the situation is different, as these languages have their own package management tool (cpan, pip, gem, npm, and so on). For some of these languages, the amount of dependencies for even a simple program can easily balloon to the point that many distros have given up on packaging non-C code. For this reason, it has become increasingly normal for developers to download dependencies into a self-contained local environment, instead of relying on distro packages. Fortunately, this affects QEMU only at build time, as qemu.git does not package non-C artifacts such as the qemu.qmp package; but still, as we make more use of Python, we experience a clash between a support policy that is written for the C world, and dependencies (both direct and indirect) that increasingly do not care for the distro versions and are quick at moving past Python runtime versions that are declared end-of-life. For example, Python 3.6 has been EOL'd since December 2021 and Meson 0.62 (released the following March) already dropped support for it. Yet, Python 3.6 is the default version of the Python runtime for RHEL/CentOS 8 and SLE 15, respectively the penultimate and the most recent version of two distros that QEMU would like to support. (It is also the version used by Ubuntu 18.04, but QEMU stopped supporting it in April 2022). There are good reasons to move forward with the deprecation of Python 3.6 in QEMU as well: completing the configure->meson switch (which requires Meson 0.63), and making the QAPI generator fully typed (which requires newer versions of not just mypy but also Python, due to PEP563). Fortunately, these long-term support distros do include newer versions of the Python runtime. However, these more recent runtimes only come with a very small subset of the Python packages that the distro includes. Because most dependencies are optional tests (avocado, mypy, flake8) and Meson is bundled with QEMU, the most noticeably missing package is Sphinx (and the readthedocs theme). There are four possibilities: * we change the support policy and stop supporting CentOS 8 and SLE 15; not a good idea since CentOS 8 is not an unreasonable distro for us to want to continue to support * we keep supporting Python 3.6 until CentOS 8 and SLE 15 stop being supported. This is a possibility---but we may want to revise the support policy anyway because SLE 16 has not even been released, so this would mean delaying those desirable reasons for perhaps three years; * we support Python 3.6 just for building documentation, i.e. we are careful not to use Python 3.7+ features in our Sphinx extensions but are free to use them elsewhere. Besides being more complicated to understand for developers, this can be quite limiting; parts of the QAPI generator run at sphinx-build time, which would exclude one of the areas which would benefit from a newer version of the runtime; * we only support Python 3.7+, which means CentOS 8 CI and users have to either install Sphinx from pip or disable documentation. This proposed update to the support policy chooses the last of these possibilities. It does by modifying three aspects of the support policy: * it introduces different support periods for *native* vs. *non-native* dependencies. Non-native dependencies are currently Python ones only, and for simplicity the policy only mentions Python; however, the concept generalizes to other languages with a well-known upstream package manager, that users of older distributions can fetch dependencies from; * it opens up the possibility of taking non-native dependencies from their own package index instead of using the version in the distribution. The wording right now is specific to dependencies that are only required at build time. In the future we may have to refine it if, for example, parts of QEMU will be written in Rust; in that case, crates would be handled in a similar way to submodules and vendored in the release tarballs. * it mentions specifically that optional build dependencies are excluded from the platform policy. Tools such as mypy don't affect the ability to build QEMU and move fast enough that distros cannot standardize on a single version of them (for example RHEL9 does not package them at all, nor does it run them at rpmbuild time). In other cases, such as cross compilers, we have alternatives. Right now, non-native dependencies have to be download manually by running "pip" before "configure". In the future, it will be desirable for configure to set up a virtual environment and download them in the same way that it populates git submodules (but, in this case, without vendoring them in the release tarballs). Just like with submodules, this would make things easier for people that can afford accessing the network in their build environment; the option to populate the build environment manually would remain for people whose build machines lack network access. The change to the support policy neither requires nor forbids this future change. [Thanks to Daniel P. Berrangé, Peter Maydell and others for discussions that were copied or summarized in the above commit message] Cc: Markus Armbruster <armbru@redhat.com> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: John Snow <jsnow@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-02-17 15:09:56 +03:00
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
docs/system: convert Texinfo documentation to rST Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-02-28 18:36:05 +03:00
-------
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.
docs/system: convert Texinfo documentation to rST Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-02-28 18:36:05 +03:00
Only 64-bit Windows is supported.
.. _Homebrew: https://brew.sh/
.. _MacPorts: https://www.macports.org/
.. _MSYS2: https://www.msys2.org/
.. _Repology: https://repology.org/