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

On 2/27/23 01:50, Daniel P. Berrangé wrote: > 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. Agreed.

> 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. Ack. > > ``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. Missing "kvm" in this last sentence?  It is otherwise untrue for tcg.