Re: [PATCH v10 06/50] x86/sev: Add the host SEV-SNP initialization support

[Borislav Petkov]

On Tue, Nov 07, 2023 at 12:32:58PM -0600, Tom Lendacky wrote:
> It needs to be called early enough to allow for AutoIBRS to not be disabled
> just because SNP is supported. By calling it where it is currently called,
> the SNP feature can be cleared if, even though supported, SNP can't be used,
> allowing AutoIBRS to be used as a more performant Spectre mitigation.

So far so good.

However, early_rmptable_check -> snp_get_rmptable_info is unnecessary
work which happens on every AP for no reason whatsoever. That's reading
RMP_BASE and RMP_END, doing the same checks which it did on the BSP and
then throwing away the computed rmp_base and rmp_sz, all once per AP.

I don't mind doing early work which needs to be done only once.

I mind doing work which needs to be done only once, on every AP.

Thx.

-- 
Regards/Gruss,
    Boris.

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