vfio/pci: Handle INTx IRQ_NOTCONNECTED

[ Upstream commit 860be250fc32de9cb24154bf21b4e36f40925707 ]

Some systems report INTx as not routed by setting pdev->irq to
IRQ_NOTCONNECTED, resulting in a -ENOTCONN error when trying to
setup eventfd signaling.  Include this in the set of conditions
for which the PIN register is virtualized to zero.

Additionally consolidate vfio_pci_get_irq_count() to use this
virtualized value in reporting INTx support via ioctl and sanity
checking ioctl paths since pdev->irq is re-used when the device
is in MSI mode.

The combination of these results in both the config space of the
device and the ioctl interface behaving as if the device does not
support INTx.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20250311230623.1264283-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index 7902e1ec0fef2fa3746fe06e42c7cce71e6f128b..105243d83b2dce31708485f8222527629355b13f 100644 (file)
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -1806,7 +1806,8 @@ int vfio_config_init(struct vfio_pci_core_device *vdev)
                                        cpu_to_le16(PCI_COMMAND_MEMORY);
        }
 
-       if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || vdev->nointx)
+       if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || vdev->nointx ||
+           vdev->pdev->irq == IRQ_NOTCONNECTED)
                vconfig[PCI_INTERRUPT_PIN] = 0;
 
        ret = vfio_cap_init(vdev);

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index f357fd157e1ed7cc65ad6f75a9ebfe2804f75743..aa362b434413a956f1313808c0a2532318226a65 100644 (file)
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -719,15 +719,7 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_finish_enable);
 static int vfio_pci_get_irq_count(struct vfio_pci_core_device *vdev, int irq_type)
 {
        if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
-               u8 pin;
-
-               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;
+               return vdev->vconfig[PCI_INTERRUPT_PIN] ? 1 : 0;
        } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
                u8 pos;
                u16 flags;

diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index 5cbcde32ff79e2664cf56dd6eac2f2c0fa2af09b..64d78944efa538867879d82414b6062bc0bccbbd 100644 (file)
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -207,7 +207,7 @@ static int vfio_intx_enable(struct vfio_pci_core_device *vdev,
        if (!is_irq_none(vdev))
                return -EINVAL;
 
-       if (!pdev->irq)
+       if (!pdev->irq || pdev->irq == IRQ_NOTCONNECTED)
                return -ENODEV;
 
        name = kasprintf(GFP_KERNEL_ACCOUNT, "vfio-intx(%s)", pci_name(pdev));