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

[Huang, Kai]

On Thu, 2018-12-06 at 06:59 -0800, Dave Hansen wrote:
> On 12/6/18 3:22 AM, Kirill A. Shutemov wrote:
> > > When you say "disable encryption to a page" does the encryption get
> > > actually disabled or does the CPU just decrypt it transparently i.e.
> > > what happens physically?
> > 
> > Yes, it gets disabled. Physically. It overrides TME encryption.
> 
> I know MKTME itself has a runtime overhead and we expect it to have a
> performance impact in the low single digits.  Does TME have that
> overhead?  Presumably MKTME plus no-encryption is not expected to have
> the overhead.
> 
> We should probably mention that in the changelogs too.
> 

I believe in terms of hardware crypto overhead MKTME and TME should have the same (except MKTME no-
encrypt case?). But MKTME might have additional overhead from software implementation in kernel?

Thanks,
-Kai