Revert "vfio/pci: Inject page response upon response region fill"

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

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

This reverts commit 9b4742a6.
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

@@ -607,32 +607,6 @@ static int vfio_pci_dma_fault_init(struct vfio_pci_device *vdev)
 	return ret;
 }
 
-static void dma_response_inject(struct work_struct *work)
-{
-	struct vfio_pci_dma_fault_response_work *rwork =
-		container_of(work, struct vfio_pci_dma_fault_response_work, inject);
-	struct vfio_region_dma_fault_response *header = rwork->header;
-	struct vfio_pci_device *vdev = rwork->vdev;
-	struct iommu_page_response *resp;
-	u32 tail, head, size;
-
-	mutex_lock(&vdev->fault_response_queue_lock);
-
-	tail = header->tail;
-	head = header->head;
-	size = header->nb_entries;
-
-	while (CIRC_CNT(head, tail, size) >= 1) {
-		resp = (struct iommu_page_response *)(vdev->fault_response_pages + header->offset +
-						tail * header->entry_size);
-
-		/* TODO: properly handle the return value */
-		iommu_page_response(&vdev->pdev->dev, resp);
-		header->tail = tail = (tail + 1) % size;
-	}
-	mutex_unlock(&vdev->fault_response_queue_lock);
-}
-
 #define DMA_FAULT_RESPONSE_RING_LENGTH 512
 
 static int vfio_pci_dma_fault_response_init(struct vfio_pci_device *vdev)
@@ -678,22 +652,8 @@ static int vfio_pci_dma_fault_response_init(struct vfio_pci_device *vdev)
 	header->nb_entries = DMA_FAULT_RESPONSE_RING_LENGTH;
 	header->offset = PAGE_SIZE;
 
-	vdev->response_work = kzalloc(sizeof(*vdev->response_work), GFP_KERNEL);
-	if (!vdev->response_work)
-		goto out;
-	vdev->response_work->header = header;
-	vdev->response_work->vdev = vdev;
-
-	/* launch the thread that will extract the response */
-	INIT_WORK(&vdev->response_work->inject, dma_response_inject);
-	vdev->dma_fault_response_wq =
-		create_singlethread_workqueue("vfio-dma-fault-response");
-	if (!vdev->dma_fault_response_wq)
-		return -ENOMEM;
-
 	return 0;
 out:
-	kfree(vdev->fault_response_pages);
 	vdev->fault_response_pages = NULL;
 	return ret;
 }

drivers/vfio/pci/vfio_pci_private.h

@@ -52,12 +52,6 @@ struct vfio_pci_irq_ctx {
 	struct irq_bypass_producer	producer;
 };
 
-struct vfio_pci_dma_fault_response_work {
-	struct work_struct inject;
-	struct vfio_region_dma_fault_response *header;
-	struct vfio_pci_device *vdev;
-};
-
 struct vfio_pci_device;
 struct vfio_pci_region;
 
@@ -159,7 +153,6 @@ struct vfio_pci_device {
 	u8			*fault_pages;
 	u8			*fault_response_pages;
 	struct workqueue_struct *dma_fault_response_wq;
-	struct vfio_pci_dma_fault_response_work *response_work;
 	struct mutex		fault_queue_lock;
 	struct mutex		fault_response_queue_lock;
 	struct list_head	dummy_resources_list;

drivers/vfio/pci/vfio_pci_rdwr.c

@@ -440,7 +440,6 @@ size_t vfio_pci_dma_fault_response_rw(struct vfio_pci_device *vdev, char __user
 		mutex_lock(&vdev->fault_response_queue_lock);
 		header->head = new_head;
 		mutex_unlock(&vdev->fault_response_queue_lock);
-		queue_work(vdev->dma_fault_response_wq, &vdev->response_work->inject);
 	} else {
 		if (copy_to_user(buf, base + pos, count))
 			return -EFAULT;