Re: KVM PMU virtualization

Jes Sorensen
2010-02-26T13:34:23Z

On 02/26/10 14:30, Avi Kivity wrote:
> On 02/26/2010 03:06 PM, Ingo Molnar wrote:
>> That's precisely my point: the guest should obviously not get raw
>> access to
>> the PMU. (except where it might matter to performance, such as RDPMC)
>
> That's doable if all counters are steerable. IIRC some counters are
> fixed function, but I'm not certain about that.

I am not an expert, but from what I learned from Peter, there are
constraints on some of the counters. Ie. certain types of events can
only be counted on certain counters, which limits the already very
limited number of counters even further.

Cheers,
Jes