Re: [PATCH v1 04/26] x86/sev: Add the host SEV-SNP initialization support

From: Borislav Petkov
Date: Fri Jan 05 2024 - 11:10:23 EST


On Thu, Jan 04, 2024 at 12:05:27PM +0100, Jeremi Piotrowski wrote:
> Is there a really good reason to perform the snp_probe_smptable_info() check at this
> point (instead of in snp_rmptable_init). snp_rmptable_init will also clear the cap
> on failure, and bsp_init_amd() runs too early to allow for the kernel to allocate the
> rmptable itself. I pointed out in the previous review that kernel allocation of rmptable
> is necessary in SNP-host capable VMs in Azure.

What does that even mean?

That function is doing some calculations after reading two MSRs. What
can possibly go wrong?!

--
Regards/Gruss,
Boris.

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