Re: [Qemu-devel] [PATCH] hw: add .min_cpus and .default_cpus fields to machine_class

[Eduardo Habkost <ehabkost@redhat.com>]

On Fri, Nov 03, 2017 at 02:56:10PM -0400, Emilio G. Cota wrote:
> On Fri, Nov 03, 2017 at 14:47:33 -0400, Emilio G. Cota wrote:
> > diff --git a/hw/arm/xlnx-zcu102.c b/hw/arm/xlnx-zcu102.c
> > index e2d15a1..395d1b5 100644
> > --- a/hw/arm/xlnx-zcu102.c
> > +++ b/hw/arm/xlnx-zcu102.c
> > @@ -185,6 +185,9 @@ static void xlnx_ep108_machine_class_init(ObjectClass *oc, void *data)
> >      mc->block_default_type = IF_IDE;
> >      mc->units_per_default_bus = 1;
> >      mc->ignore_memory_transaction_failures = true;
> > +    mc->max_cpus = XLNX_ZYNQMP_NUM_APU_CPUS + XLNX_ZYNQMP_NUM_RPU_CPUS;
> > +    mc->min_cpus = XLNX_ZYNQMP_NUM_APU_CPUS;
> > +    mc->default_cpus = XLNX_ZYNQMP_NUM_APU_CPUS;
> >  }
> >  
> >  static const TypeInfo xlnx_ep108_machine_init_typeinfo = {
> > @@ -241,6 +244,8 @@ static void xlnx_zcu102_machine_class_init(ObjectClass *oc, void *data)
> >      mc->units_per_default_bus = 1;
> >      mc->ignore_memory_transaction_failures = true;
> >      mc->max_cpus = XLNX_ZYNQMP_NUM_APU_CPUS + XLNX_ZYNQMP_NUM_RPU_CPUS;
> > +    mc->min_cpus = XLNX_ZYNQMP_NUM_APU_CPUS;
> > +    mc->default_cpus = XLNX_ZYNQMP_NUM_APU_CPUS;
> >  }
> 
> Should we update max_cpus to just NUM_APU_CPUS as well for these boards?
> -smp 5 or 6 (NUM_APU + NUM_RPU) still gets us 4 vCPUs.
> 
> I see there's code for RPU cpus but it seems disabled at compile-time
> at xlnx-zynqmp.c:431:
>    DEFINE_PROP_BOOL("has_rpu", XlnxZynqMPState, has_rpu, false)
> Or is there a run-time way to override this?

Device properties can be overridden using -global, e.g.:

  -global driver=xlnx,,zynqmp,property=has_rpu,value=on

(",," is how commas are escaped in QEMU options)

-- 
Eduardo