Re: [PATCH v6 00/11] Intel SGX Driver

From: Jarkko Sakkinen
Date: Wed Jan 10 2018 - 11:17:22 EST


On Tue, Jan 09, 2018 at 03:50:23PM -0600, Dr. Greg Wettstein wrote:
> > Everything going out of L1 gets encrypted. This is done to defend
> > against peripheral like adversaries and should work also against
> > meltdown.
>
> I don't believe this is an architecturally correct assertion. The
> encryption/decryption occurs at the 'bottom' of the cache heirarchy.

You are right and I was wrong. It is plain from L1 to LLC, which implies
as you correctly described potential cache missing attacks in addition
to timing attacks.

/Jarkko