Re: [Patch v4 07/13] perf/x86: Add constraint for guest perf metrics event

From: Peter Zijlstra
Date: Mon Oct 02 2023 - 08:29:45 EST


On Fri, Sep 29, 2023 at 08:50:07PM +0530, Ravi Bangoria wrote:
> On 29-Sep-23 5:23 PM, Peter Zijlstra wrote:

> > I don't think you need to go that far, host can use PMU just fine as
> > long as it doesn't overlap with a vCPU. Basically, if you force
> > perf_attr::exclude_guest on everything your vCPU can haz the full thing.

^ this..

> How about keying off based on PMU specific KVM module parameter? Something
> like what Manali has proposed for AMD VIBS? Please see solution 1.1:
>
> https://lore.kernel.org/r/3a6c693e-1ef4-6542-bc90-d4468773b97d@xxxxxxx

So I hadn't read that, but isn't that more or less what I proposed
above?