Re: [PATCH] [RFC] kvm: x86: emulate APERF/MPERF registers

[Paolo Bonzini]

On 27/04/20 19:30, Jim Mattson wrote:
>>>> I would like to see performance data before enabling this
>>>> unconditionally.
>>> I wouldn't want this to be enabled unconditionally anyway,
>>> because you need to take into account live migration to and from
>>> processors that do not have APERF/MPERF support.
>>> 
>>> Paolo
>> I will add a kvm parameter to consider whether enable MPERF/APERF
>> emulations, and make default value to false
>
> Wouldn't it be better to add a per-VM capability to enable this
> feature?

Yes, you it would be better to use KVM_ENABLE_CAP indeed.

Paolo