RE: [PATCH 1/5] hw/arm/smmuv3: Introduce SMMUv3 device

[Shameerali Kolothum Thodi via]

> -----Original Message-----
> From: Nicolin Chen <nicol...@nvidia.com>
> Sent: Wednesday, April 16, 2025 4:42 AM
> To: Shameerali Kolothum Thodi <shameerali.kolothum.th...@huawei.com>
> Cc: qemu-...@nongnu.org; qemu-devel@nongnu.org;
> eric.au...@redhat.com; peter.mayd...@linaro.org; j...@nvidia.com;
> ddut...@redhat.com; berra...@redhat.com; nath...@nvidia.com;
> mo...@nvidia.com; smost...@google.com; Linuxarm
> <linux...@huawei.com>; Wangzhou (B) <wangzh...@hisilicon.com>;
> jiangkunkun <jiangkun...@huawei.com>; Jonathan Cameron
> <jonathan.came...@huawei.com>; zhangfei....@linaro.org
> Subject: Re: [PATCH 1/5] hw/arm/smmuv3: Introduce SMMUv3 device
> 
> On Tue, Apr 15, 2025 at 09:11:00AM +0100, Shameer Kolothum wrote:
> > +static int smmuv3_dev_pcie_bus(Object *obj, void *opaque)
> > +{
> > +    DeviceState *d = opaque;
> > +    PCIBus *bus;
> > +
> > +    if (!object_dynamic_cast(obj, TYPE_PCI_HOST_BRIDGE)) {
> > +        return 0;
> > +    }
> > +
> > +    bus = PCI_HOST_BRIDGE(obj)->bus;
> > +    if (d->parent_bus && !strcmp(bus->qbus.name, d->parent_bus-
> >name)) {
> > +        object_property_set_link(OBJECT(d), "primary-bus", OBJECT(bus),
> > +                                 &error_abort);
> > +        return 1;
> 
> Return 1 would break the caller's foreach. And I guess that's what
> we want since "primary-bus" should only be set once?

Yes. It will only set once and once you get it no need to iterate again.
> 
> Maybe better to add a line of comments to explain that a bit?
Ok.

> 
> > +    }
> > +    return 0;
> > +}
> > +
> > +static void smmuv3_dev_realize(DeviceState *d, Error **errp)
> > +{
> > +    SMMUv3DevState *s_nested = ARM_SMMUV3_DEV(d);
> > +    SMMUv3DevClass *c = ARM_SMMUV3_DEV_GET_CLASS(s_nested);
> 
Oops...that's probably from a prototype code I had earlier!. 

Thanks,
Shameer