Re: [PATCH 1/2] docs/about: Deprecate 32-bit x86 hosts and qemu-system-i386

On Mon, Feb 27, 2023 at 12:10:49PM +0100, Thomas Huth wrote: > Hardly anybody still uses 32-bit x86 hosts today, so we should > start deprecating them to finally have less test efforts. > With regards to 32-bit KVM support in the x86 Linux kernel, > the developers confirmed that they do not need a recent > qemu-system-i386 binary here: > > https://lore.kernel.org/kvm/Y%2ffkTs5ajFy0hP1U@google.com/ > > Signed-off-by: Thomas Huth <thuth(a)redhat.com&gt; > --- > docs/about/deprecated.rst | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst > index 15084f7bea..98517f5187 100644 > --- a/docs/about/deprecated.rst > +++ b/docs/about/deprecated.rst > @@ -196,6 +196,19 @@ CI coverage support may bitrot away before the deprecation process > completes. The little endian variants of MIPS (both 32 and 64 bit) are > still a supported host architecture. > > +32-bit x86 hosts and ``qemu-system-i386`` (since 8.0) > +''''''''''''''''''''''''''''''''''''''''''''''''''''' > + > +Testing 32-bit x86 host OS support takes a lot of precious time during the > +QEMU contiguous integration tests, and considering that most OS vendors > +stopped shipping 32-bit variants of their x86 OS distributions and most > +x86 hardware from the past >10 years is capable of 64-bit, keeping the > +32-bit support alive is an inadequate burden for the QEMU project. Thus > +QEMU will soon drop the support for 32-bit x86 host systems and the > +``qemu-system-i386`` binary. Use ``qemu-system-x86_64`` (which is a proper > +superset of ``qemu-system-i386``) on a 64-bit host machine instead. I feel like we should have separate deprecation entries for the i686 host support, and for qemu-system-i386 emulator binary, as although they're related they are independant features with differing impact.

32-bit x86 hosts '''''''''''''''' Support for 32-bit x86 host deployments is increasingly uncommon in mainstream Linux distributions given the widespread availability of 64-bit x86 hardware. The QEMU project no longer considers 32-bit x86 support to be an effective use of its limited resources, and thus intends to discontinue it. Current users of QEMU on 32-bit x86 hosts should either continue using existing releases of QEMU, with the caveat that they will no longer get security fixes, or migrate to a 64-bit platform which remains capable of running 32-bit guests if needed.

``qemu-system-i386`` binary removal ''''''''''''''''''''''''''''''''''' The ``qemu-system-x86_64`` binary can be used to run 32-bit guests by selecting a 32-bit CPU model, including KVM support on x86_64 hosts. Once support for the 32-bit x86 host platform is discontinued, the ``qemu-system-i386`` binary will be redundant.

Current users are recommended to reconfigure their systems to use the ``qemu-system-x86_64`` binary.

Same point for the next patch about 32-bit arm vs qemu-system-arm binary.