Re: [Qemu-devel] To measure Interrupt latency

[saravanakumar punith]

On Fri, May 30, 2014 at 8:26 PM, saravanakumar punith
<address@hidden> wrote:
>
> Hi,
> Is there any way to measure interrupt latency ( delay between interrupt 
> occurred and interrupt service routine is getting called) in VM.
>
> Consider a device is assigned to a VM (using passthrough).
> Now, interrupt is triggered for the device.
>
> I believe kernel code in Host side is getting called first and then  
> corresponding interrupt handler
> registered in Guest side is getting called.
>
> Now , I would like to measure the latency between
> a. interrupt notification at host side
> b. Actual interrupt handler called at Guest side
>
> Is there a (software)method exists to measure interrupt latency for a device 
> inside VM.?
> Architecutre : X86_64 and qemu-kvm used.
>
> PS:
> I read about using some high precision timer and measure time difference.
> But I am not sure whether it is possible to access the timer from  Host and 
> Guest and measure the latency.
>
> Please let me know.
> Thanks
>
>
>

Can someone help ?

Thanks