Re: [PATCHv3 17/17] x86: Introduce CONFIG_X86_INTEL_MKTME

From: Kirill A. Shutemov
Date: Mon Jun 18 2018 - 09:41:08 EST


On Wed, Jun 13, 2018 at 06:46:34PM +0000, Dave Hansen wrote:
> On 06/12/2018 07:39 AM, Kirill A. Shutemov wrote:
> > Add new config option to enabled/disable Multi-Key Total Memory
> > Encryption support.
> >
> > MKTME uses MEMORY_PHYSICAL_PADDING to reserve enough space in per-KeyID
> > direct mappings for memory hotplug.
>
> Isn't it really *the* direct mapping primarily? We make all of them
> larger, but the direct mapping is impacted too. This makes it sound
> like it applies only to the MKTME mappings.

We only cares about the padding in two cases: MKTME and KALSR.
If none of them enabled padding doesn't have meaning. We have PAGE_OFFSET
at fixed address and size is also fixed.

--
Kirill A. Shutemov