Re: SEV guest regression in 4.18

From: Borislav Petkov
Date: Sat Aug 25 2018 - 00:48:30 EST

On Fri, Aug 24, 2018 at 01:47:10PM -0500, Brijesh Singh wrote:
> I am more inclined towards creating a new section with PMD aligned and
> sized. This section will contains the decrypted data. In early
> boot code we will update the mapping with C=0. If caller wants to create
> a shared variable then it can do so with:
> static int foo __decrypted;

Right, and keeping the SEV-ES's GHCB in mind, you could make that
section extensible so that the GHCB's 4K page can land there too. Maybe
something like a PMD-aligned range of 4K pages which are fully defined
and which hypervisor and guest can share and can be used for all kinds of
communication in the future...


SUSE Linux GmbH, GF: Felix ImendÃrffer, Jane Smithard, Graham Norton, HRB 21284 (AG NÃrnberg)