Re: Performance counters in kvm?

["Binh Q. Pham" <binhpham@cs.rutgers.edu>]

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.

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.