Re: [PATCH v2 05/13] perf: Force architectures to opt-in to guest callbacks

From: Sean Christopherson
Date: Thu Sep 16 2021 - 18:30:53 EST


On Sat, Aug 28, 2021, Peter Zijlstra wrote:
> On Fri, Aug 27, 2021 at 05:35:50PM -0700, Sean Christopherson wrote:
> > diff --git a/init/Kconfig b/init/Kconfig
> > index 55f9f7738ebb..9ef51ae53977 100644
> > --- a/init/Kconfig
> > +++ b/init/Kconfig
> > @@ -1776,6 +1776,9 @@ config HAVE_PERF_EVENTS
> > help
> > See tools/perf/design.txt for details.
> >
> > +config HAVE_GUEST_PERF_EVENTS
> > + bool
> depends on HAVE_KVM
>
> ?

Ah, nice! We can go even further to:

depends on HAVE_PERF_EVENTS && HAVE_KVM

though I'm pretty sure all architectures that select HAVE_KVM also select
HAVE_PERF_EVENTS.

Huh. arm64 doesn't select HAVE_KVM even though it selects almost literally every
other HAVE_KVM_* config. arm64 has some other weirdness with CONFIG_KVM, I'll add
a patch or two to fix that stuff and amend this patch as above.

Thanks again!