Re: [PATCH kernel v3 3/3] x86/sev: Do not handle #VC for DR7 read/write

From: Nikunj A. Dadhania
Date: Tue Jan 24 2023 - 05:38:52 EST




On 20/01/23 15:53, Alexey Kardashevskiy wrote:
> It is MSR_AMD64_SEV_DEBUG_SWAP (SEV, not SNP), it is an SEV-ES thing.

Yes, noticed that, earlier analysis was that Debug Swap shouldn't need any guest side changes, but it does need it.

> Why is that feature negotiation SNP-only and not SEV?

As per the spec, GHCB termination request: reason code: 0x2 is SNP features specific.

Regards
Nikunj