Re: [PATCH] x86/Intel: use CPUID bit to determine PPIN availability

[Andrew Cooper <amc96@xxxxxxxx>]

On 17/01/2022 15:30, Jan Beulich wrote:
> As of SDM revision 076 there is a CPUID bit for this functionality. Use
> it to amend the existing model-based logic.
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

https://lore.kernel.org/lkml/20220107225442.1690165-1-tony.luck@xxxxxxxxx/T/#u
suggests that Sapphire Rapids also needs the model specific treatment.

I agree with the "only-expose-on-error" observation, so perhaps we ought
to make these details available to the hardware domain in a suitable form.

~Andrew