On 2020/6/8 ??2:32, Michael S. Tsirkin wrote:> On Mon, Jun 08, 2020 at 11:32:31AM +0800, Jason Wang wrote: >> On 2020/6/7 ??9:51, Michael S. Tsirkin wrote: >>> On Fri, Jun 05, 2020 at 04:54:17PM +0800, Jason Wang wrote: >>>> On 2020/6/2 ??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.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[] = { >> ??? { 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) }, > >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
On Mon, Jun 08, 2020 at 05:18:44PM +0800, Jason Wang wrote:> > On 2020/6/8 ??2:32, Michael S. Tsirkin wrote: > > On Mon, Jun 08, 2020 at 11:32:31AM +0800, Jason Wang wrote: > > > On 2020/6/7 ??9:51, Michael S. Tsirkin wrote: > > > > On Fri, Jun 05, 2020 at 04:54:17PM +0800, Jason Wang wrote: > > > > > On 2020/6/2 ??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. > > > Do you want me to implement "driver_overrid" in this series, or a NULL > id_table is sufficient?Doesn't the pci subsystem create driver_override for all devices on the pci bus?> > > > > > > > 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) }, > > > > > > IFCVF use this to avoid the binding to regular virtio device.Ow. Indeed: #define IFCVF_VENDOR_ID 0x1AF4 Which is of course not an IFCVF vendor id, it's the Red Hat vendor ID. I missed that. Does it actually work if you bind a virtio driver to it? I'm guessing no otherwise they wouldn't need IFC driver, right?> Looking at > pci_match_one_device() it checks both subvendor and subdevice there. > > ThanksBut IIUC there is no guarantee that driver with a specific subvendor matches in presence of a generic one. So either IFC or virtio pci can win, whichever binds first. I guess we need to blacklist IFC in virtio pci probe code. Ugh. -- MST
On 2020/6/8 ??5:31, Michael S. Tsirkin wrote:> On Mon, Jun 08, 2020 at 05:18:44PM +0800, Jason Wang wrote: >> On 2020/6/8 ??2:32, Michael S. Tsirkin wrote: >>> On Mon, Jun 08, 2020 at 11:32:31AM +0800, Jason Wang wrote: >>>> On 2020/6/7 ??9:51, Michael S. Tsirkin wrote: >>>>> On Fri, Jun 05, 2020 at 04:54:17PM +0800, Jason Wang wrote: >>>>>> On 2020/6/2 ??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. >> >> Do you want me to implement "driver_overrid" in this series, or a NULL >> id_table is sufficient? > > Doesn't the pci subsystem create driver_override for all devices > on the pci bus?Yes, I miss this.>>>>>> 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) }, >>> >>> >> IFCVF use this to avoid the binding to regular virtio device. > > Ow. Indeed: > > #define IFCVF_VENDOR_ID 0x1AF4 > > Which is of course not an IFCVF vendor id, it's the Red Hat vendor ID. > > I missed that. > > Does it actually work if you bind a virtio driver to it?It works.> I'm guessing no otherwise they wouldn't need IFC driver, right? >Looking at the driver, they used a dedicated bar for dealing with virtqueue state save/restore. It> > >> Looking at >> pci_match_one_device() it checks both subvendor and subdevice there. >> >> Thanks > > But IIUC there is no guarantee that driver with a specific subvendor > matches in presence of a generic one. > So either IFC or virtio pci can win, whichever binds first.I'm not sure I get there. But I try manually bind IFCVF to qemu's virtio-net-pci, and it fails. Thanks> > I guess we need to blacklist IFC in virtio pci probe code. Ugh.>