Re: [PATCH v1 04/26] x86/sev: Add the host SEV-SNP initialization support

From: Borislav Petkov
Date: Mon Jan 08 2024 - 12:05:24 EST


On Mon, Jan 08, 2024 at 05:49:01PM +0100, Jeremi Piotrowski wrote:
> What I wrote: "allow for the kernel to allocate the rmptable".

What?!

"15.36.5 Hypervisor RMP Management

...

Because the RMP is initialized by the AMD-SP to prevent direct access to
the RMP, the hypervisor must use the RMPUPDATE instruction to alter the
entries of the RMP. RMPUPDATE allows the hypervisor to alter the
Guest_Physical_Address, Assigned, Page_Size, Immutable, and ASID fields
of an RMP entry."

What you want is something that you should keep far and away from the
upstream kernel.

--
Regards/Gruss,
Boris.

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