diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index cddb453a1ba5..50cdedfca9fe 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -434,10 +434,14 @@ static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type) { if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) { u8 pin; - pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin); - if (IS_ENABLED(CONFIG_VFIO_PCI_INTX) && !vdev->nointx && pin) - return 1; + if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || + vdev->nointx || vdev->pdev->is_virtfn) + return 0; + + pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin); + + return pin ? 1 : 0; } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) { u8 pos; u16 flags; diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c index 62023b4a373b..423ea1f98441 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -1611,6 +1611,15 @@ static int vfio_ecap_init(struct vfio_pci_device *vdev) return 0; } +/* + * Nag about hardware bugs, hopefully to have vendors fix them, but at least + * to collect a list of dependencies for the VF INTx pin quirk below. + */ +static const struct pci_device_id known_bogus_vf_intx_pin[] = { + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x270c) }, + {} +}; + /* * For each device we allocate a pci_config_map that indicates the * capability occupying each dword and thus the struct perm_bits we @@ -1676,6 +1685,24 @@ int vfio_config_init(struct vfio_pci_device *vdev) if (pdev->is_virtfn) { *(__le16 *)&vconfig[PCI_VENDOR_ID] = cpu_to_le16(pdev->vendor); *(__le16 *)&vconfig[PCI_DEVICE_ID] = cpu_to_le16(pdev->device); + + /* + * Per SR-IOV spec rev 1.1, 3.4.1.18 the interrupt pin register + * does not apply to VFs and VFs must implement this register + * as read-only with value zero. Userspace is not readily able + * to identify whether a device is a VF and thus that the pin + * definition on the device is bogus should it violate this + * requirement. We already virtualize the pin register for + * other purposes, so we simply need to replace the bogus value + * and consider VFs when we determine INTx IRQ count. + */ + if (vconfig[PCI_INTERRUPT_PIN] && + !pci_match_id(known_bogus_vf_intx_pin, pdev)) + pci_warn(pdev, + "Hardware bug: VF reports bogus INTx pin %d\n", + vconfig[PCI_INTERRUPT_PIN]); + + vconfig[PCI_INTERRUPT_PIN] = 0; /* Gratuitous for good VFs */ } if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || vdev->nointx)