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

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

> From: Igor Mammedov [mailto:imammedo@redhat.com]
> Sent: Friday, June 5, 2020 4:31 PM
> To: Andrew Jones <drjones@redhat.com>
> Cc: Salil Mehta <salil.mehta@huawei.com>; qemu-devel@nongnu.org;
> qemu-arm@nongnu.org; Peter Maydell <peter.maydell@linaro.org>; mst@redhat.com
> Subject: Re: [Question] Regarding PMU initialization within the QEMU for ARM
> VCPUs
> 
> On Wed, 3 Jun 2020 11:37:45 +0200
> Andrew Jones <drjones@redhat.com> wrote:
> 
> > On Mon, Jun 01, 2020 at 03:04:33PM +0000, Salil Mehta wrote:
> > > Hello,
> > > I could see below within function fdt_add_pmu_nodes() part of
> > > hw/arm/virt.c during virt machine initialization time:
> ...
> >
> > > Q4. This function  fdt_* looks to be wrongly named. The info
> > >     being initialized here shall be used even when ACPI is
> > >     being used. Initialization part and FDT info looked
> > >     mixed up here if I am right?
> >
> > Agreed. The function has the wrong name. mach-virt has many functions that
> > mix the initialization and fdt building together, but those functions are
> > named something like create_foo(). Patches welcome.
> that was where I gave up on cpu hotplug arm/virt the last time.

Were you releasing the ARM objects as well? Or are you referring to some
other problem?

> Ideally we should split out from create_foo() all firmware generation code
> (fdt) and move it to virt_machine_done time + make sure that it could be
> regenerated at reset time so guest would get updated FDT on reset.

Agreed, just like ACPI part. That would be more cleaner. 

Thanks
Salil.