Re: [Qemu-devel] [Question] Static probe Qemu for CPU operation on KVM mode

[Ady Wahyudi Paundu]

Hi Stefan,

It was just as you explain, the CPU utilization profile of a VM.
Previously I thought there are any relevant trace events to it inside
Qemu with KVM mode. (There are obviously some when using Qemu with
TCG, since there are translation operations at work)
Thank you for the direction.

~Ady

On 8/6/15, Stefan Hajnoczi <address@hidden> wrote:
> On Thu, Aug 06, 2015 at 04:58:02AM +0900, Ady Wahyudi Paundu wrote:
>> If I want to profile a VM's CPU load when running Qemu with KVM mode
>> using static probe instrumentation, where (which file/function) should
>> I put my trace points?
>
> What are you trying to measure?
>
> Linux tools on the host will report CPU utilization for the QEMU process
> but also for the individual vcpus (they are threads and you can query
> their tids using the 'query-cpus' QMP command).  Plain old ps(1) and
> pidstat(1) will do the trick.
>
> Or you might want to look at "sudo perf list | grep kvm" for the
> KVM-specific host kernel trace events.  The most relevant trace events
> are probably kvm:kvm_entry and kvm:kvm_exit.  These events tell you when
> guest code starts/stops executing.
>
> Stefan
>