Re: arm: "max" CPU class hierarchy changes possible?

[Paolo Bonzini]

On 11/03/21 16:02, Peter Maydell wrote:
> On Thu, 11 Mar 2021 at 14:27, Claudio Fontana <cfontana@suse.de> wrote:
> > the "max" cpu in x86 and s390 is a class,
> >
> > and then "host" has "max" as parent.
> >
> > This would be a convenient setup for ARM too, as it would allow to put common code 
> > between kvm and tcg in the "max" class,
> > and allow "host" to specialize the behavior for KVM (and in the future HVF 
> > probably).
> >
> > Would changing the class hierarchy this way be acceptable, cause any problems?
>
> It's not clear to me why 'host' would be a subtype of 'max':
> that doesn't seem like an obvious relationship.

On x86, "-cpu host" is essentially the same as "-cpu max" with the only 
difference that it errors out on TCG.  So:

- with TCG: "-cpu max" enables all that can be emulated, "-cpu host" fails

- with KVM: "-cpu max" enables all that can be virtualized, "-cpu host" 
does the same

Paolo