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

[Daniel P. Berrangé <berrange@xxxxxxxxxx>]

On Tue, Feb 28, 2023 at 10:14:52AM +0100, Thomas Huth wrote:
> On 28/02/2023 10.03, Michael S. Tsirkin wrote:
> > On Tue, Feb 28, 2023 at 08:59:52AM +0000, Daniel P. Berrangé wrote:
> > > On Tue, Feb 28, 2023 at 03:19:20AM -0500, Michael S. Tsirkin wrote:
> > > > On Tue, Feb 28, 2023 at 08:49:09AM +0100, Thomas Huth wrote:
> > > > > On 27/02/2023 21.12, Michael S. Tsirkin wrote:
> > > > > > On Mon, Feb 27, 2023 at 11:50:07AM +0000, Daniel P. Berrangé wrote:
> > > > > > > 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. eg removing qemu-system-i386 affects all
> > > > > > > host architectures, not merely 32-bit x86 host, so I think we
> > > > > > > can explain the impact more clearly if we separate them.
> > > > > > 
> > > > > > Removing qemu-system-i386 seems ok to me - I think 
> > > > > > qemu-system-x86_64 is
> > > > > > a superset.
> > > > > > 
> > > > > > Removing support for building on 32 bit systems seems like a pity - 
> > > > > > it's
> > > > > > one of a small number of ways to run 64 bit binaries on 32 bit 
> > > > > > systems,
> > > > > > and the maintainance overhead is quite small.
> > > > > 
> > > > > Note: We're talking about 32-bit *x86* hosts here. Do you really 
> > > > > think that
> > > > > someone is still using QEMU usermode emulation
> > > > > to run 64-bit binaries on a 32-bit x86 host?? ... If so, I'd be very 
> > > > > surprised!
> > > > 
> > > > I don't know - why x86 specifically? One can build a 32 bit binary on 
> > > > any host.
> > > > I think 32 bit x86 environments are just more common in the cloud.
> > > 
> > > Can you point to anything that backs up that assertion. Clouds I've
> > > seen always give you a 64-bit environment, and many OS no longer
> > > even ship 32-bit installable media.
> > 
> > Sorry about being unclear. I meant that it seems easier to run CI in the
> > cloud in a 32 bit x64 environment than get a 32 bit ARM environment.
> 
> It's still doable ... but for how much longer? We're currently depending on
> Fedora, but they also slowly drop more and more support for this
> environment, see e.g.:

FWIW, we should cull our fedora-i386-cross.docker dockerfile and
replace it with a debian i686 dockerfile generated by lcitool.
There's no compelling reason why i686 should be different from
all our other cross builds which are based on Debian. The Debian
lcitool generated container would have access to a wider range
of deps than our hand written Fedora one.

>  https://www.theregister.com/2022/03/10/fedora_inches_closer_to_dropping/

With regards,
Daniel
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