On Tue, 17 Oct 2023 16:42:17 +0300 Yishai Hadas <yishaih@xxxxxxxxxx> wrote: > +static int virtiovf_pci_probe(struct pci_dev *pdev, > + const struct pci_device_id *id) > +{ > + const struct vfio_device_ops *ops = &virtiovf_acc_vfio_pci_ops; > + struct virtiovf_pci_core_device *virtvdev; > + int ret; > + > + if (pdev->is_virtfn && virtiovf_support_legacy_access(pdev) && > + !virtiovf_bar0_exists(pdev) && pdev->msix_cap) > + ops = &virtiovf_acc_vfio_pci_tran_ops; This is still an issue for me, it's a very narrow use case where we have a modern device and want to enable legacy support. Implementing an IO BAR and mangling the device ID seems like it should be an opt-in, not standard behavior for any compatible device. Users should generally expect that the device they see in the host is the device they see in the guest. They might even rely on that principle. We can't use the argument that users wanting the default device should use vfio-pci rather than virtio-vfio-pci because we've already defined the algorithm by which libvirt should choose a variant driver for a device. libvirt will choose this driver for all virtio-net devices. This driver effectively has the option to expose two different profiles for the device, native or transitional. We've discussed profile support for variant drivers previously as an equivalent functionality to mdev types, but the only use case for this currently is out-of-tree. I think this might be the opportunity to define how device profiles are exposed and selected in a variant driver. Jason had previously suggested a devlink interface for this, but I understand that path had been shot down by devlink developers. Another obvious option is sysfs, where we might imagine an optional "profiles" directory, perhaps under vfio-dev. Attributes of "available" and "current" could allow discovery and selection of a profile similar to mdev types. Is this where we should head with this or are there other options to confine this transitional behavior? BTW, what is "acc" in virtiovf_acc_vfio_pci_ops? > + > + virtvdev = vfio_alloc_device(virtiovf_pci_core_device, core_device.vdev, > + &pdev->dev, ops); > + if (IS_ERR(virtvdev)) > + return PTR_ERR(virtvdev); > + > + dev_set_drvdata(&pdev->dev, &virtvdev->core_device); > + ret = vfio_pci_core_register_device(&virtvdev->core_device); > + if (ret) > + goto out; > + return 0; > +out: > + vfio_put_device(&virtvdev->core_device.vdev); > + return ret; > +} > + > +static void virtiovf_pci_remove(struct pci_dev *pdev) > +{ > + struct virtiovf_pci_core_device *virtvdev = dev_get_drvdata(&pdev->dev); > + > + vfio_pci_core_unregister_device(&virtvdev->core_device); > + vfio_put_device(&virtvdev->core_device.vdev); > +} > + > +static const struct pci_device_id virtiovf_pci_table[] = { > + /* Only virtio-net is supported/tested so far */ > + { PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_REDHAT_QUMRANET, 0x1041) }, > + {} > +}; > + > +MODULE_DEVICE_TABLE(pci, virtiovf_pci_table); > + > +static struct pci_driver virtiovf_pci_driver = { > + .name = KBUILD_MODNAME, > + .id_table = virtiovf_pci_table, > + .probe = virtiovf_pci_probe, > + .remove = virtiovf_pci_remove, > + .err_handler = &vfio_pci_core_err_handlers, > + .driver_managed_dma = true, > +}; > + > +module_pci_driver(virtiovf_pci_driver); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Yishai Hadas <yishaih@xxxxxxxxxx>"); > +MODULE_DESCRIPTION( > + "VIRTIO VFIO PCI - User Level meta-driver for VIRTIO device family"); Not yet "family" per the device table. Thanks, Alex _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization