Re: [PATCH v1 0/2] s390x/cpumodel: Introduce "best" model variants

[Peter Maydell]

On Tue, 19 Nov 2019 at 09:59, David Hildenbrand <address@hidden> wrote:
>
> On 19.11.19 10:22, Peter Maydell wrote:
> > I don't hugely care about query-cpu-model-expansion. I
> > just don't want it to have bad effects on the semantics
> > of user-facing stuff like x- properties.
>
> IMHO, max should really include all features (yes, also the bad
> x-features on arm :) ) and we should have a way to give users the
> opportunity to specify "just give me the best model independent of the
> accelerator" - something like a "best" model, but I don't care about the
> name.

How would "max includes all features" work if we have two
x- features (or even two normal features!) which are incompatible
with each other? How does it work for features which are
valid for some other CPU type but not for 'max'? The design
seems to assume a rather simplified system where every
feature is independent and can always be applied to every
CPU, which I don't think is guaranteed to be the case.

thanks
-- PMM