Re: [RFC] [PATCH v2 0/5] Intel Virtual PMU Optimization

From: Andi Kleen
Date: Mon Mar 25 2019 - 11:58:30 EST


> It isn't going anywhere anyway, its insane. You let perf do all its
> normal things and then discard the results by avoiding the wrmsr.
>
> Then you fudge a second wrmsr path somewhere.
>
> Please, just make the existing event dtrt.

I still think the right way is to force an event to a counter
from an internal field. And then set that field from KVM.
This is quite straight forward to do in the event scheduler.

I did it for some experimential PEBS virtualization patches
which require the same because they have to expose the
counter indexes inside the PEBS record to the guest.

-Andi