[PATCH v11 10/13] vfio/pci: Register and allow DMA FAULT IRQ signaling

[Eric Auger]

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.au...@redhat.com>

---

v10 -> v11:
- the irq now is registered in vfio_pci_dma_fault_init()
  in case the domain is nested
---
 drivers/vfio/pci/vfio_pci.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 93e03a4a5f32..65a83fd0e8c0 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -397,6 +397,7 @@ int vfio_pci_iommu_dev_fault_handler(struct iommu_fault 
*fault, void *data)
                (struct vfio_region_dma_fault *)vdev->fault_pages;
        struct iommu_fault *new;
        u32 head, tail, size;
+       int ext_irq_index;
        int ret = -EINVAL;
 
 
@@ -422,7 +423,19 @@ int vfio_pci_iommu_dev_fault_handler(struct iommu_fault 
*fault, void *data)
        ret = 0;
 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
@@ -474,6 +487,12 @@ static int vfio_pci_dma_fault_init(struct vfio_pci_device 
*vdev)
        if (ret) /* the dma fault region is freed in vfio_pci_disable() */
                goto out;
 
+       ret = vfio_pci_register_irq(vdev, VFIO_IRQ_TYPE_NESTED,
+                                   VFIO_IRQ_SUBTYPE_DMA_FAULT,
+                                   VFIO_IRQ_INFO_EVENTFD);
+       if (ret) /* the fault handler is also freed in vfio_pci_disable() */
+               goto out;
+
        return 0;
 out:
        kfree(vdev->fault_pages);
-- 
2.21.3

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