diff options
| -rw-r--r-- | hw/vfio/pci.c | 44 |
1 files changed, 36 insertions, 8 deletions
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index eb7627c5f9..ad508abd6f 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -369,6 +369,33 @@ static void vfio_msi_interrupt(void *opaque) notify(&vdev->pdev, nr); } +/* + * Get MSI-X enabled, but no vector enabled, by setting vector 0 with an invalid + * fd to kernel. + */ +static int vfio_enable_msix_no_vec(VFIOPCIDevice *vdev) +{ + g_autofree struct vfio_irq_set *irq_set = NULL; + int ret = 0, argsz; + int32_t *fd; + + argsz = sizeof(*irq_set) + sizeof(*fd); + + irq_set = g_malloc0(argsz); + irq_set->argsz = argsz; + irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | + VFIO_IRQ_SET_ACTION_TRIGGER; + irq_set->index = VFIO_PCI_MSIX_IRQ_INDEX; + irq_set->start = 0; + irq_set->count = 1; + fd = (int32_t *)&irq_set->data; + *fd = -1; + + ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set); + + return ret; +} + static int vfio_enable_vectors(VFIOPCIDevice *vdev, bool msix) { struct vfio_irq_set *irq_set; @@ -618,6 +645,8 @@ static void vfio_commit_kvm_msi_virq_batch(VFIOPCIDevice *vdev) static void vfio_msix_enable(VFIOPCIDevice *vdev) { + int ret; + vfio_disable_interrupts(vdev); vdev->msi_vectors = g_new0(VFIOMSIVector, vdev->msix->entries); @@ -640,8 +669,6 @@ static void vfio_msix_enable(VFIOPCIDevice *vdev) vfio_commit_kvm_msi_virq_batch(vdev); if (vdev->nr_vectors) { - int ret; - ret = vfio_enable_vectors(vdev, true); if (ret) { error_report("vfio: failed to enable vectors, %d", ret); @@ -655,13 +682,14 @@ static void vfio_msix_enable(VFIOPCIDevice *vdev) * MSI-X capability, but leaves the vector table masked. We therefore * can't rely on a vector_use callback (from request_irq() in the guest) * to switch the physical device into MSI-X mode because that may come a - * long time after pci_enable_msix(). This code enables vector 0 with - * triggering to userspace, then immediately release the vector, leaving - * the physical device with no vectors enabled, but MSI-X enabled, just - * like the guest view. + * long time after pci_enable_msix(). This code sets vector 0 with an + * invalid fd to make the physical device MSI-X enabled, but with no + * vectors enabled, just like the guest view. */ - vfio_msix_vector_do_use(&vdev->pdev, 0, NULL, NULL); - vfio_msix_vector_release(&vdev->pdev, 0); + ret = vfio_enable_msix_no_vec(vdev); + if (ret) { + error_report("vfio: failed to enable MSI-X, %d", ret); + } } trace_vfio_msix_enable(vdev->vbasedev.name); |