Re: [RFC 00/10] Process-local memory allocations for hiding KVM secrets

From: Dave Hansen
Date: Wed Jun 12 2019 - 16:00:19 EST


On 6/12/19 10:08 AM, Marius Hillenbrand wrote:
> This patch series proposes to introduce a region for what we call
> process-local memory into the kernel's virtual address space.

It might be fun to cc some x86 folks on this series. They might have
some relevant opinions. ;)

A few high-level questions:

Why go to all this trouble to hide guest state like registers if all the
guest data itself is still mapped?

Where's the context-switching code? Did I just miss it?

We've discussed having per-cpu page tables where a given PGD is only in
use from one CPU at a time. I *think* this scheme still works in such a
case, it just adds one more PGD entry that would have to context-switched.