Re: Performance counters in kvm?

[Gleb Natapov <gleb@redhat.com>]

On Wed, Nov 13, 2013 at 10:22:54PM -0500, Binh Q. Pham wrote:
> Hi Gleb,
> Thanks for the suggestion, but I just tried to specify the cpu type
> to QEMU: -cpu host and I got the same output.
> 
Which QEMU version are you using, what is the output of "cat
/proc/cpuinfo" in the guest and attach guest's dmesg too.

> Binh
> On 11/13/2013 12:54 PM, Gleb Natapov wrote:
> >On Wed, Nov 13, 2013 at 11:52:01AM -0500, Binh Q. Pham wrote:
> >>Hi all,
> >>
> >>I just started using kvm and want to use linux 'perf' tool inside
> >>the virtual machine to get some information about the hardware
> >>performance counters. I noticed in kvm source, there is pmu.c and
> >>pmu-stubs.c, so I assume they provide support for PMU. However, when
> >>I ran 'perf stat' in the VM, all hardware events are not supported.
> >>Sample screen shot:
> >>
> >>perf stat /bin/ls
> >>Performance counter stats for '/bin/ls':
> >><not supported> cycles
> >><not supported> stalled-cycles-frontend
> >>....
> >>
> >>Could someone clarify for me if I can use 'perf' in VM with the
> >>current kvm state?
> >>
> >You need to specify host cpu type to QEMU: -cpu host.
> >
> >--
> >			Gleb.

--
			Gleb.