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Date:   Mon, 8 Jun 2020 02:32:42 -0400
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     Jason Wang <jasowang@redhat.com>
Cc:     kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
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        zhangweining@ruijie.com.cn, eli@mellanox.com
Subject: Re: [PATCH 5/6] vdpa: introduce virtio pci driver
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On Mon, Jun 08, 2020 at 11:32:31AM +0800, Jason Wang wrote:
> 
> On 2020/6/7 下午9:51, Michael S. Tsirkin wrote:
> > On Fri, Jun 05, 2020 at 04:54:17PM +0800, Jason Wang wrote:
> > > On 2020/6/2 下午3:08, Jason Wang wrote:
> > > > > > +static const struct pci_device_id vp_vdpa_id_table[] = {
> > > > > > +    { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
> > > > > > +    { 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.

> 
> > 
> > > 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[] = {
>     { PCI_DEVICE_SUB(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID,
> VP_TEST_VENDOR_ID, VP_TEST_DEVICE_ID) },
>     { 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) },


-- 
MST