Re: Performance counters in kvm?

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

On 12/10/2013 05:59 AM, Gleb Natapov wrote:
> On Mon, Dec 09, 2013 at 01:59:41PM -0500, Binh Q. Pham wrote:
>> Sorry for a late response as I was distracted by another task in the
>> last few weeks. Today, I compiled and installed QEMU 1.7.0 from
>> source, but no luck with this. Tested on a different machine with
>> different kernel version: 3.2, I got the same results.
> What do you mean by "different kernel version: 3.2"?

Oh, previously, I tried with kernel 3.10. Then I had another machine 
with 3.2, so I tried QEMU 1.7.0 on both, but no luck.
>
>> Btw, I found bug 798936 which describes similar problem here:
>> bugzilla.redhat.com/show_bug.cgi?id=798936
>>
>> it seems like this problem has been detected and resolved in the
>> past. Do you know what Linux distro/kernel that the bug was resolved
>> on? Maybe I can try that instead of using ubuntu to see if it works.
>>
> The fix is present in QEMU 1.7.0.
>
>> Thanks,
>> Binh
>> On 11/14/2013 04:08 PM, Gleb Natapov wrote:
>>> On Thu, Nov 14, 2013 at 03:31:01PM -0500, Binh Q. Pham wrote:
>>>> My host kernel version is 3.10.17
>>>>
>>> That one surely has PMU emulation, but your guest does not see it. I blame
>>> QEMU. Can you compile QEMU from git?
>>>
>>>> Binh
>>>> On 11/14/2013 12:21 PM, Gleb Natapov wrote:
>>>>> On Thu, Nov 14, 2013 at 12:04:50PM -0500, Binh Q. Pham wrote:
>>>>>> cpuid output is attached.
>>>>> PMU support is not advertised to the guest which means that either
>>>>> QEMU is broken or your host kernel does not have PMU kvm support. What is
>>>>> your host kernel version?
>>>>>
>>>>>> I didn't know that the kernel was not compiled with virtualization
>>>>>> support as I was using a ready image from ubuntu website to install
>>>>>> the VM. In the long run, are you suggesting me to recompile the
>>>>>> kernel for the guest to make sure that it has virtualization
>>>>>> support?
>>>>>>
>>>>> I am surprised ubuntu kernel does not have virtualiztion support
>>>>> compiled in. May be they have separate kernel for that, but I am not
>>>>> ubuntu user so cannot tell.
>>>>>
>>>>>
>>>>> --
>>>>> 			Gleb.
>>> --
>>> 			Gleb.
>>
>> -- 
>> -Binh
>>
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> --
> 			Gleb.