Re: [PATCH 0/2] Deprecate support for 32-bit x86 and arm hosts

[Thomas Huth <thuth@redhat.com>]

On 27/02/2023 19.38, Daniel P. Berrangé wrote:
> On Mon, Feb 27, 2023 at 12:10:48PM +0100, Thomas Huth wrote:
>> We're struggling quite badly with our CI minutes on the shared
>> gitlab runners, so we urgently need to think of ways to cut down
>> our supported build and target environments. qemu-system-i386 and
>> qemu-system-arm are not really required anymore, since nobody uses
>> KVM on the corresponding systems for production anymore, and the
>> -x86_64 and -arch64 variants are a proper superset of those binaries.
>> So it's time to deprecate them and the corresponding 32-bit host
>> environments now.
>>
>> This is a follow-up patch series from the previous discussion here:
>>
>>   https://lore.kernel.org/qemu-devel/20230130114428.1297295-1-thuth@redhat.com/
>>
>> where people still mentioned that there is still interest in certain
>> support for 32-bit host hardware. But as far as I could see, there is
>> no real need for 32-bit host support for system emulation on x86 and
>> arm anymore, so it should be fine if we drop these host environments
>> now (these are also the two architectures that contribute the most to
>> the long test times in our CI, so we would benefit a lot by dropping
>> those).
> 
> Your description here is a little ambiguous about what's being
> proposed. When you say dropping 32-bit host support do you mean
> just for the system emulator binaries, or for QEMU entirely ?

Just for system emulation. Some people said that user emulation still might 
be useful for some 32-bit environments.

> And when the deprecation period is passed, are you proposing
> to actively prevent 32-bit builds, or merely stopping CI testing
> and leave 32-bit builds still working if people want them ?

CI is the main pain point, so that's the most important thing. So whether we 
throw a warning or a hard error while configuring the build, I don't care 
too much.

  Thomas