From 43236995e8ad336d366b625fb8362046be53fc34 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Mon, 29 Jan 2024 09:46:34 +0100 Subject: [PATCH] vfio/pci: Clear MSI-X IRQ index always MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Cédric Le Goater RH-MergeRequest: 218: vfio/pci: Clear MSI-X IRQ index always RH-Jira: RHEL-21293 RH-Acked-by: Eric Auger RH-Acked-by: Alex Williamson RH-Commit: [1/1] b4b587b13c11e350d3e5fcc11ba66a006b25a763 (clegoate/qemu-kvm-c9s) JIRA: https://issues.redhat.com/browse/RHEL-21293 commit d2b668fca5652760b435ce812a743bba03d2f316 Author: Cédric Le Goater Date: Thu Jan 25 14:27:36 2024 +0100 vfio/pci: Clear MSI-X IRQ index always When doing device assignment of a physical device, MSI-X can be enabled with no vectors enabled and this sets the IRQ index to VFIO_PCI_MSIX_IRQ_INDEX. However, when MSI-X is disabled, the IRQ index is left untouched if no vectors are in use. Then, when INTx is enabled, the IRQ index value is considered incompatible (set to MSI-X) and VFIO_DEVICE_SET_IRQS fails. QEMU complains with : qemu-system-x86_64: vfio 0000:08:00.0: Failed to set up TRIGGER eventfd signaling for interrupt INTX-0: VFIO_DEVICE_SET_IRQS failure: Invalid argument To avoid that, unconditionaly clear the IRQ index when MSI-X is disabled. Buglink: https://issues.redhat.com/browse/RHEL-21293 Fixes: 5ebffa4e87e7 ("vfio/pci: use an invalid fd to enable MSI-X") Cc: Jing Liu Cc: Alex Williamson Reviewed-by: Alex Williamson Signed-off-by: Cédric Le Goater Signed-off-by: Cédric Le Goater --- hw/vfio/pci.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index adb7c09367..29bb8067eb 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -829,9 +829,11 @@ static void vfio_msix_disable(VFIOPCIDevice *vdev) } } - if (vdev->nr_vectors) { - vfio_disable_irqindex(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX); - } + /* + * Always clear MSI-X IRQ index. A PF device could have enabled + * MSI-X with no vectors. See vfio_msix_enable(). + */ + vfio_disable_irqindex(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX); vfio_msi_disable_common(vdev); vfio_intx_enable(vdev, &err); -- 2.39.3