[PATCH v9 10/11] vfio/pci: Register and allow DMA FAULT IRQ signaling

Eric Auger
2019-07-11T13:59:10Z

Register the VFIO_IRQ_TYPE_NESTED/VFIO_IRQ_SUBTYPE_DMA_FAULT
IRQ that allows to signal a nested mode DMA fault.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
drivers/vfio/pci/vfio_pci.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index dcc246202094..a9df964e40c6 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -344,7 +344,7 @@ int vfio_pci_iommu_dev_fault_handler(struct iommu_fault *fault, void *data)
struct iommu_fault *new =
(struct iommu_fault *)(vdev->fault_pages + reg->offset +
reg->head * reg->entry_size);
- int head, tail, size;
+ int head, tail, size, ext_irq_index;
int ret = 0;

if (fault->type != IOMMU_FAULT_DMA_UNRECOV)
@@ -365,7 +365,19 @@ int vfio_pci_iommu_dev_fault_handler(struct iommu_fault *fault, void *data)
reg->head = (head + 1) % size;
unlock:
mutex_unlock(&vdev->fault_queue_lock);
- return ret;
+ if (ret)
+ return ret;
+
+ ext_irq_index = vfio_pci_get_ext_irq_index(vdev, VFIO_IRQ_TYPE_NESTED,
+ VFIO_IRQ_SUBTYPE_DMA_FAULT);
+ if (ext_irq_index < 0)
+ return -EINVAL;
+
+ mutex_lock(&vdev->igate);
+ if (vdev->ext_irqs[ext_irq_index].trigger)
+ eventfd_signal(vdev->ext_irqs[ext_irq_index].trigger, 1);
+ mutex_unlock(&vdev->igate);
+ return 0;
}

#define DMA_FAULT_RING_LENGTH 512
@@ -518,6 +530,12 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
if (ret)
goto disable_exit;

+ ret = vfio_pci_register_irq(vdev, VFIO_IRQ_TYPE_NESTED,
+ VFIO_IRQ_SUBTYPE_DMA_FAULT,
+ VFIO_IRQ_INFO_EVENTFD);
+ if (ret)
+ goto disable_exit;
+
vfio_pci_probe_mmaps(vdev);

return 0;
--
2.20.1