[RFC v2 00/13] Multi-Key Total Memory Encryption API (MKTME)

[Huang, Kai]

> I strongly suspect that, on L1TF-vulnerable CPUs, MKTME provides no
> protection whatsoever.  It sounds like MKTME is implemented in the
> memory controller -- as far as the rest of the CPU and the cache hierarchy
> are concerned, the MKTME key selction bits are just part of the physical
> address.  So an attack like L1TF that leaks a cacheline that's selected by
> physical address will leak the cleartext if the key selection bits are set
> correctly.

Right. MKTME doesn't prevent cache based attack. Data in cache is in clear.

Thanks,
-Kai