Re: [PATCH] perf/x86/intel: Use rdmsrl_safe when initializing RAPL PMU.

David Ahern
2014-03-14T16:58:22Z

On 3/14/14, 10:17 AM, Andi Kleen wrote:
>> The Intel ISR section for RDMSR seems to say: "Specifying a reserved
>> or unimplemented
>> MSR address in ECX will also cause a general protection exception".
>>
>> From a guest's perspective, MSR_RAPL_POWER_UNIT is unimplemented; kvm matches
>> this behavior.
>
> MSRs are model specific and defined per model number. If you report a model
> number you're expected to implement the MSRs defined for that model number.
>
> AFAIK Xen just reports 0 for unknown MSRs (and I'm surprised KVM doesn't too)
>
> I would suggest to fix KVM.

I believe ignore_msrs parameter to kvm handles that.

David