RE: [Question] Regarding PMU initialization within the QEMU for ARM VCPUs

[Salil Mehta <salil.mehta@huawei.com>]

> From: Qemu-arm [mailto:qemu-arm-bounces+salil.mehta=huawei.com@nongnu.org]
> On Behalf Of Andrew Jones
> Sent: Wednesday, June 3, 2020 3:37 PM
> To: Salil Mehta <salil.mehta@huawei.com>
> Cc: Peter Maydell <peter.maydell@linaro.org>; mst@redhat.com;
> qemu-devel@nongnu.org; eric.auger@redhat.com; qemu-arm@nongnu.org; Igor
> Mammedov <imammedo@redhat.com>
> Subject: Re: [Question] Regarding PMU initialization within the QEMU for ARM
> VCPUs
> 
> On Wed, Jun 03, 2020 at 01:48:10PM +0000, Salil Mehta wrote:
> > (Maybe I should float the ARM VCPU Hotplug patches and let this
> >  discussion be held over there?)
> >
> 
> Yes, I think that would be best. Keep in mind that the 'pmu' CPU property
> is just one CPU property that we require all CPUs to have, if any have it.
> 'aarch64' and 'sve' are two other examples. And, likely any CPU feature
> that comes down the line that we want to use with KVM will fit that
> pattern. I think the hotplug patch series will need to handle those
> features in some way other than to push them all into machine properties.

Sure, I do have realization about that. I have for now used a per virt
machine flag for PMU to do a workaround of the problem I discussed.
Maybe once I float the patches further comments on the ways to improve
the design would be very helpful. So for now I will keep the flag and
use this approach and invite everyone for open discussion about this
and we could evolve the design as we discuss there.


Many thanks
Salil.