Re: [PATCH v5 01/32] x86: Documentation for AMD Secure Memory Encryption (SME)

Borislav Petkov
2017-04-19T15:38:39Z

On Wed, Apr 19, 2017 at 09:23:47AM -0500, Tom Lendacky wrote:
> Btw, I tried to update all the subjects and descriptions to be
> more descriptive but I'm sure there is still room for improvement
> so keep the comments on them coming.

No worries there :)

> Note, just because the bit is set in %cr3 doesn't mean the full
> hierarchy is encrypted. Each level in the hierarchy needs to have the
> encryption bit set. So, theoretically, you could have the encryption
> bit set in %cr3 so that the PGD is encrypted, but not set the encryption
> bit in the PGD entry for a PUD and so the PUD pointed to by that entry
> would not be encrypted.

Ha, that is a nice detail I didn't realize. You could add it to the text.

Thanks.

--
Regards/Gruss,
Boris.

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