linux-kernel - Re: [PATCH] KVM: x86: Sort CPUID_8000_0021

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Message-ID: <20250411094551.GAZ_jkz8N2zDkkPbTt@fat_crate.local>
Date: Fri, 11 Apr 2025 11:45:51 +0200
From: Borislav Petkov <bp@...en8.de>
To: Sean Christopherson <seanjc@...gle.com>
Cc: Borislav Petkov <bp@...nel.org>, Paolo Bonzini <pbonzini@...hat.com>,
	X86 ML <x86@...nel.org>, KVM <kvm@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] KVM: x86: Sort CPUID_8000_0021_EAX leaf bits properly

On Thu, Apr 10, 2025 at 02:46:39PM -0700, Sean Christopherson wrote:
> I'm going to skip these, as they aren't yet publicly documented,

https://www.amd.com/content/dam/amd/en/documents/epyc-technical-docs/programmer-references/57238.zip

> and there are patches proposed to add actual support.  I wouldn't care all
> that much if these didn't collide with Intel's version (the proposed patches
> name them AMD_FSxx).
>
> https://lore.kernel.org/all/20241204134345.189041-2-davydov-max@yandex-team.ru

Pff, I think the right thing to do is to detect those and when set, set the
Intel flags because they're basically the same.

Lemme go reply there.

... goes and replies...

> 
> >  		/* PrefetchCtlMsr */
> > -		F(WRMSR_XX_BASE_NS),
> > +		/* GpOnUserCpuid */
> > +		/* EPSF */
> 
> FWIW, this one's also not in the APM (though the only APM I can find is a year old),
> though it's in tools/x86/kcpuid.

See above. Yeah, the PPRs have them earlier than the APM.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette