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

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Message-ID: <20190204164121.GG29639@zn.tnic>
Date:   Mon, 4 Feb 2019 17:41:21 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     "Liang, Kan" <kan.liang@...ux.intel.com>
Cc:     Peter Zijlstra <peterz@...radead.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org, tglx@...utronix.de, mingo@...hat.com,
        ak@...ux.intel.com, eranian@...gle.com
Subject: Re: [PATCH V6 2/5] perf/x86/kvm: Avoid unnecessary work in guest
 filtering

On Mon, Feb 04, 2019 at 11:23:13AM -0500, Liang, Kan wrote:
> I mean that the microcode version number is irrelevant between stepping.
> Let's use SKL server as an example.
> +	INTEL_CPU_DESC(INTEL_FAM6_SKYLAKE_X,		 3, 0x00000021),
> +	INTEL_CPU_DESC(INTEL_FAM6_SKYLAKE_X,		 4, 0x00000000),
> 
> We need the function to check the min microcode version number for each
> stepping.

So you need to say "ignore stepping". I.e., X86_STEPPING_ANY.

-- 
Regards/Gruss,
    Boris.

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