Re: [Qemu-devel] pert stat in KVM guest can not get LLC-loads hardware cache event

[Steven]

Hi, Kan,
Thanks for your reply.

1. If the guest is non-paravirt, can I get the LLC-loads number?
2. Do you know any method that can capture the LLC-loads for the guest? Thanks.

- Hui


On Wed, Aug 27, 2014 at 9:05 AM, Liang, Kan <address@hidden> wrote:
>
>
>
> >
> > Dear KVM developers:
> > I am trying use perf stat inside a VM to obtain some hardware cache
> > performance counter values.
> > The perf stat can report some numbers for L1 and TLB related counters. But
> > for the LLC-loads and LLC-load-misses, the numbers are always 0. It seems
> > that the these offcore events are not exposed to the guest.
> >
> > Is this a bug in Qemu or KVM?
> >
>
> There is no offcore virtualization support in KVM yet.
> For you case, I guess you are using paravirt for guest, so it should be 0.
> Otherwise, you should get #GP in guest.
>
>
> > My testbed is
> >
> > Host kernel: 3.12.26
> > Qemu: 2.1.0
> > CPU: Intel Ivy bridge 2620
> > VM boosted by qemu, with -cpu host.
> >
> > Thanks.
> >
> > - Hui Kang