Re: [PATCH 3/3] KVM: SVM: allow to intercept all exceptions for debug

From: Joerg Roedel
Date: Thu Mar 18 2021 - 05:21:06 EST

On Tue, Mar 16, 2021 at 12:51:20PM +0200, Maxim Levitsky wrote:
> I agree but what is wrong with that?
> This is a debug feature, and it only can be enabled by the root,
> and so someone might actually want this case to happen
> (e.g to see if a SEV guest can cope with extra #VC exceptions).

That doesn't make sense, we know that and SEV-ES guest can't cope with
extra #VC exceptions, so there is no point in testing this. It is more a
way to shot oneself into the foot for the user and a potential source of
bug reports for SEV-ES guests.

> I have nothing against not allowing this for SEV-ES guests though.
> What do you think?

I think SEV-ES guests should only have the intercept bits set which
guests acutally support.