On Tue, 14 Dec 2021 13:45:34 +0800 Cai Huoqing <cai.huoq...@linux.dev> wrote:
> No support MSI-X in BAIDU KUNLUN Virtual Function devices, > so add a quirk to avoid setuping VFIO MSI-X > > Signed-off-by: Cai Huoqing <cai.huoq...@linux.dev> > --- > hw/vfio/pci.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c > index 7b45353ce2..15f76bbe56 100644 > --- a/hw/vfio/pci.c > +++ b/hw/vfio/pci.c > @@ -1994,6 +1994,13 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev, > uint8_t pos, Error **errp) > ret = vfio_setup_pcie_cap(vdev, pos, size, errp); > break; > case PCI_CAP_ID_MSIX: > + /* > + * BAIDU KUNLUN Virtual Function devices for KUNLUN AI processor > + * don't support MSI-X, so don't setup VFIO MSI-X here. > + */ > + if (vdev->vendor_id == PCI_VENDOR_ID_BAIDU && > + vdev->device_id == PCI_DEVICE_ID_KUNLUN_VF) > + break; > ret = vfio_msix_setup(vdev, pos, errp); > break; > case PCI_CAP_ID_PM: So the VF exposes an MSI-X capability but it's entirely unsupported and/or bogus? If it's not bogus, why can't we support it? How does the host kernel driver know to avoid MSI-X? Should we use the same mechanism used by the host driver to quirk whether vfio-pci exposes the MSI-X capability to userspace at all? Thanks, Alex
