Revert "vfio/pci: Register and allow DMA FAULT IRQ signaling"

virt inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I61SPO
CVE: NA

--------------------------------

This reverts commit b6f29e4d.
Signed-off-by: NKunkun Jiang <jiangkunkun@huawei.com>
Reviewed-by: NKeqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/vfio/pci/vfio_pci.c

@@ -451,7 +451,6 @@ 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;
 
 	if (WARN_ON(!reg))
@@ -476,19 +475,7 @@ vfio_pci_iommu_dev_fault_handler(struct iommu_fault *fault, void *data)
 	ret = 0;
 unlock:
 	mutex_unlock(&vdev->fault_queue_lock);
-	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;
+	return ret;
 }
 
 #define DMA_FAULT_RING_LENGTH 512
@@ -543,12 +530,6 @@ 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);