Re: [PATCH v2 5/8] KVM: x86: Add WARNs to detect out-of-bounds register indices

From: Sean Christopherson
Date: Wed Oct 09 2019 - 12:36:02 EST


On Wed, Oct 09, 2019 at 12:50:44PM +0200, Paolo Bonzini wrote:
> On 27/09/19 23:45, Sean Christopherson wrote:
> > Open code the RIP and RSP accessors so as to avoid pointless overhead of
> > WARN_ON_ONCE().
>
> Is there actually an overhead here? It is effectively WARN_ON_ONCE(0)
> which should be compiled out just fine.

Doh, you're correct, it does get compiled out.