Re: [PATCH RFC v7 52/64] KVM: SVM: Provide support for SNP_GUEST_REQUEST NAE event

From: Dionna Amalie Glaze
Date: Mon May 15 2023 - 12:45:28 EST

On Thu, May 11, 2023 at 4:33 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
> On Thu, May 11, 2023, Dionna Amalie Glaze wrote:
> > Would it be okay to request that we add a KVM stat for how often there
> > are GUEST_REQUEST_NAE exits? I think it'd be good for service
> > operators to get a better idea how valued the feature is.
> Heh, it's always ok to request something, but sometimes the answer will be no.
> And in the case, the answer is likely "no stat for you". A year or so ago, in the
> context of us (Google) trying to upstream a pile of stats, we (KVM folks) came to
> a rough consensus that KVM should only add upstream stats if they are relatively
> generic and (almost) universally useful[*]. IMO, a one-off stat for a specific exit
> reason is too narrowly focused, e.g. collecting information on all exit reasons is
> superior. And no, that won't be accepted upstream either, because for some environments
> gathering detailed information on all exits is too much overhead (also covered in
> the link).
> FWIW, we (GCE) plan on carrying stats like this in out-of-tree patches, i.e. your
> request for stats is likely something that would get accepted internally (if it
> isn't already captured through our generic stats collection).
> [*]

Thanks Sean, noted :)

-Dionna Glaze, PhD (she/her)