Re: [RFC][PATCH v2 00/21] x86/pti: Defer CR3 switch to C code

From: Borislav Petkov
Date: Mon Nov 16 2020 - 15:17:52 EST


On Mon, Nov 16, 2020 at 03:47:36PM +0100, Alexandre Chartre wrote:
> This RFC proposes to defer the PTI CR3 switch until we reach C code.
> The benefit is that this simplifies the assembly entry code, and make
> the PTI CR3 switch code easier to understand. This also paves the way
> for further possible projects such an easier integration of Address
> Space Isolation (ASI), or the possibilily to execute some selected
> syscall or interrupt handlers without switching to the kernel page-table

What for? What is this going to be used for in the end?

> (and thus avoid the PTI page-table switch overhead).

Overhead of how much? Why do we care?

What is the big picture justfication for this diffstat

> 21 files changed, 874 insertions(+), 314 deletions(-)

and the diffstat for the ASI enablement?

Thx.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette