Re: [PATCH V6 2/5] perf/x86/kvm: Avoid unnecessary work in guest filtering

Borislav Petkov
2019-02-04T16:05:11Z

On Mon, Feb 04, 2019 at 10:57:32AM -0500, Liang, Kan wrote:
>
>
> On 2/4/2019 10:44 AM, Peter Zijlstra wrote:
> > On Mon, Feb 04, 2019 at 04:38:27PM +0100, Peter Zijlstra wrote:
> > > +static const struct x86_cpu_desc isolation_ucodes[] = {
> > > + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_MOBILE, 9, 0x0000004e),
> > > + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_MOBILE, 10, 0x0000004e),
> > > + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_MOBILE, 11, 0x0000004e),
> > > + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_MOBILE, 12, 0x0000004e),
> >
> > > + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_DESKTOP, 10, 0x0000004e),
> > > + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_DESKTOP, 11, 0x0000004e),
> > > + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_DESKTOP, 12, 0x0000004e),
> > > + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_DESKTOP, 13, 0x0000004e),
> >
> > Do we want a special stepping (0 / -1) to be able to denote 'all' ?
> >
>
> Something like as below?
> #define X86_STEPPING_ANY 0xff
>
> As my understanding, the microcode version for each stepping is independent
> and irrelevant.

Huh?

Why are we looking at the stepping then?

x86_match_cpu_with_stepping() <---

--
Regards/Gruss,
Boris.

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