Re: [PATCH v10 21/45] x86/mm: Add support to validate memory when changing C-bit

From: Borislav Petkov
Date: Sun Feb 13 2022 - 12:21:40 EST


On Sun, Feb 13, 2022 at 08:50:48AM -0600, Tom Lendacky wrote:
> I think there were a lot of assumptions that only SME/SEV would set
> sme_me_mask and that is used, for example, in the cc_platform_has() routine
> to figure out whether we're AMD or Intel. If you go the cc_mask route, I
> think we'll need to add a cc_vendor variable that would then be checked in
> cc_platform_has().

Right, or cc_platform_type or whatever. It would probably be a good
idea to have a variable explicitly state what the active coco flavor is
anyway, as we had some ambiguity questions in the past along the lines
of, what does cc_platform_has() need to return when running as a guest
on the respective platform.

If you have it explicitly, then it would work unambiguously simple. And
then we can get rid of CC_ATTR_GUEST_SEV_SNP or CC_ATTR_GUEST_TDX which
is clumsy.

Thx.

--
Regards/Gruss,
Boris.

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