Re: [PATCH v6 10/90] x86/cpu: Rescan CPUID table after disabling PSN

[Christian Ludloff]

On Wed, May 13, 2026 at 10:39 AM Borislav Petkov <bp@xxxxxxxxx> wrote:
> Maybe... later...
>
> Right now the *only* thing we wanna do *first* is the conversion. Which is
> a huuge undertaking in itself.
>
> So please no more unrelated changes and "it would be good to do this and
> that." That can be done later.
>
> If we find a bug while doing so then it is very likely an existing bug which
> we'll fix immeditely and continue with the conversion.
>
> Once everything has been converted and the dust settles, *then* w can do
> improvements ontop.

When deciding what the code shall do for mutable CPUID bits,
you really want to have an exhaustive list of events that trigger
changes – think Intel SDM vol1 21.1.5 as a starting point; then
made exhaustive for all events, for Intel and the other vendors.

(Besides on/off bits spread all over the place, microcode loads
at runtime come to mind as... uhm... interesting...)

--
C.