Re: [PATCH] perf/x86: KVM: Disable vPMU support on hybrid CPUs (host PMUs)

[Liang, Kan]

On 2023-01-23 8:04 p.m., Andi Kleen wrote:
> 
>> If I understand correct, the workaround in KVM is to add a white/black
>> list to filter the events. I think we can do the same thing for the
>> hybrid machine for now.
>> https://lore.kernel.org/lkml/CAOyeoRUUK+T_71J=+zcToyL93LkpARpsuWSfZS7jbJq=wd1rQg@xxxxxxxxxxxxxx/
> 
> 
> This will make everyone who actually wants to use the PMU sad.

Yes, but we still have all the architecture events work. I think it
should be good enough as a short-term solution, when the hybrid is not
completely supported in KVM.
> 
> It's reasonable if the vCPUs are not bound, but if they are bound it
> would be better to expose it with a suitable CPUID for the types.
> 

Yes, and also the CPUID leaf 0x23H support to enumerate the PMU features
of each types.


Thanks,
Kan