On POWER systems, when the device is behind the io expander, not all PCI slots would have the PCI_INTERRUPT_LINE connected. The firmware assigns a valid PCI_INTERRUPT_PIN though. In such configuration, the irq_info ioctl currently advertizes the irq count as 1 as the PCI_INTERRUPT_PIN is valid.
The patch adds the additional check[1] if the irq is assigned for the PIN which is done iff the LINE is connected. [1]: https://lore.kernel.org/qemu-devel/20250131150201.048aa3bf.alex.william...@redhat.com/ Signed-off-by: Shivaprasad G Bhat <sb...@linux.ibm.com> Suggested-By: Alex Williamson <alex.william...@redhat.com> --- drivers/vfio/pci/vfio_pci_core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 586e49efb81b..4ce70f05b4a8 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -734,6 +734,10 @@ static int vfio_pci_get_irq_count(struct vfio_pci_core_device *vdev, int irq_typ return 0; pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin); +#if IS_ENABLED(CONFIG_PPC64) + if (!vdev->pdev->irq) + pin = 0; +#endif return pin ? 1 : 0; } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
