Re: [PATCH 5/6] vdpa: introduce virtio pci driver

[Jason Wang]

On 2020/6/8 äå2:32, Michael S. Tsirkin wrote:
> On Mon, Jun 08, 2020 at 11:32:31AM +0800, Jason Wang wrote:
> > On 2020/6/7 äå9:51, Michael S. Tsirkin wrote:
> > > On Fri, Jun 05, 2020 at 04:54:17PM +0800, Jason Wang wrote:
> > > > On 2020/6/2 äå3:08, Jason Wang wrote:
> > > > > > > +static const struct pci_device_id vp_vdpa_id_table[] = {
> > > > > > > +ÂÂÂ { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
> > > > > > > +ÂÂÂ { 0 }
> > > > > > > +};
> > > > > > This looks like it'll create a mess with either virtio pci
> > > > > > or vdpa being loaded at random. Maybe just don't specify
> > > > > > any IDs for now. Down the road we could get a
> > > > > > distinct vendor ID or a range of device IDs for this.
> > > > > Right, will do.
> > > > >
> > > > > Thanks
> > > > Rethink about this. If we don't specify any ID, the binding won't work.
> > > We can bind manually. It's not really for production anyway, so
> > > not a big deal imho.
> >
> > I think you mean doing it via "new_id", right.
> I really meant driver_override. This is what people have been using
> with pci-stub for years now.


Do you want me to implement "driver_overrid" in this series, or a NULL 
id_table is sufficient?


> > > > How about using a dedicated subsystem vendor id for this?
> > > >
> > > > Thanks
> > > If virtio vendor id is used then standard driver is expected
> > > to bind, right? Maybe use a dedicated vendor id?
> >
> > I meant something like:
> >
> > static const struct pci_device_id vp_vdpa_id_table[] = {
> >  ÂÂÂ { PCI_DEVICE_SUB(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID,
> > VP_TEST_VENDOR_ID, VP_TEST_DEVICE_ID) },
> >  ÂÂÂ { 0 }
> > };
> >
> > Thanks
> Then regular virtio will still bind to it. It has
>
> drivers/virtio/virtio_pci_common.c:     { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },

IFCVF use this to avoid the binding to regular virtio device. Looking at 
pci_match_one_device() it checks both subvendor and subdevice there.

Thanks