Re: [PATCH Part1 RFC v3 11/22] x86/sev: Add helper for validating pages in early enc attribute changes

Borislav Petkov
2021-06-14T19:03:22Z

On Mon, Jun 14, 2021 at 07:45:11AM -0500, Brijesh Singh wrote:
> IMO, there is no need to add a warning. This case should happen if its
> either a hypervisor bug or hypervisor does not follow the GHCB
> specification. I followed the SEV-ES vmgexit handling  and it does not
> warn if the hypervisor returns a wrong response code. We simply
> terminate the guest.

This brings my regular user-friendliness question: will the guest user
know what happened or will the guest simply disappear/freeze without any
hint as to what has happened so that a post-mortem analysis would turn
out hard to decipher?

> I did thought about reusing the VMGEXIT defined macro
> SNP_PAGE_STATE_{PRIVATE, SHARED} but I was not sure if you will be okay
> with that.

Yeah, I think that makes stuff simpler. Unless there's something
speaking against it which we both are not thinking of right now.

> Additionally now both the function name and macro name will
> include the "SNP". The call will look like this:
>
> snp_prep_memory(paddr, SNP_PAGE_STATE_PRIVATE)

Yap, looks ok to me.

Thx.

--
Regards/Gruss,
Boris.