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Date:   Fri, 28 Jan 2022 23:58:32 +0100
From:   Borislav Petkov <bp@alien8.de>
To:     Michael Roth <michael.roth@amd.com>
Cc:     Brijesh Singh <brijesh.singh@amd.com>, x86@kernel.org,
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Subject: Re: [PATCH v8 29/40] x86/compressed/64: add support for SEV-SNP
 CPUID table in #VC handlers
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References: <20220118142345.65wuub2p3alavhpb@amd.com>
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On Wed, Jan 19, 2022 at 10:27:47AM -0600, Michael Roth wrote:
> At that point it's much easier for the guest owner to just check the
> CPUID values directly against known good values for a particular
> configuration as part of their attestation process and leave the
> untrusted cloud vendor out of it completely. So not measuring the
> CPUID page as part of SNP attestation allows for that flexibility.

Well, in that case, I guess you don't need the sanity-checking in the
guest either - you simply add it to the attestation TODO-list for the
guest owner to go through:

Upon booting, the guest owner should compare the CPUID leafs the guest
sees with the ones supplied during boot.

-- 
Regards/Gruss,
    Boris.

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