Re: [PATCH v2] spapr: Tag pseries-2.1 - 2.11 machines as deprecated

["Nicholas Piggin" <npiggin@gmail.com>]

On Tue Mar 12, 2024 at 4:56 AM AEST, Daniel P. Berrangé wrote:
> On Mon, Mar 11, 2024 at 06:46:53PM +0100, Philippe Mathieu-Daudé wrote:
> > Hi,
> > 
> > On 14/12/23 19:17, Cédric Le Goater wrote:
> > > pseries machines before version 2.11 have undergone many changes to
> > > correct issues, mostly regarding migration compatibility. This is
> > > obfuscating the code uselessly and makes maintenance more difficult.
> > > Remove them and only keep the last version of the 2.x series, 2.12,
> > > still in use by old distros.
> > 
> > By the time we get to QEMU v9.2, will pseries-2.12 still be used
> > by old distros? (which ones btw?)
>
> That's the wrong question really.
>
> Machine types are there to facilitate live migration, and by
> extension also handle save/restore to disk.
>
> So the question is more which distros are likely to ship
> new QEMU 9.2, and also still need the ability to incoming
> migrate from an older version of their distro where 2.12
> (or a downstream equiv) was a fully supported machine type.

From Cedric's list, they are ~2018 vintage. I don't know if
there is upstream policy on this, but 2025 seems reasonable
to remove support for live migration from then.

Thanks,
Nick