1 files changed, 75 insertions, 48 deletions

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 796fe979f997..62a9bb0efc55 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -565,6 +565,9 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
 			      perm_to_iommu_flags(perm));
 	}
 
+	if (r)
+		vhost_iotlb_del_range(dev->iotlb, iova, iova + size - 1);
+
 	return r;
 }
 
@@ -592,21 +595,19 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 	struct vhost_dev *dev = &v->vdev;
 	struct vhost_iotlb *iotlb = dev->iotlb;
 	struct page **page_list;
-	unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
+	struct vm_area_struct **vmas;
 	unsigned int gup_flags = FOLL_LONGTERM;
-	unsigned long npages, cur_base, map_pfn, last_pfn = 0;
-	unsigned long locked, lock_limit, pinned, i;
+	unsigned long map_pfn, last_pfn = 0;
+	unsigned long npages, lock_limit;
+	unsigned long i, nmap = 0;
 	u64 iova = msg->iova;
+	long pinned;
 	int ret = 0;
 
 	if (vhost_iotlb_itree_first(iotlb, msg->iova,
 				    msg->iova + msg->size - 1))
 		return -EEXIST;
 
-	page_list = (struct page **) __get_free_page(GFP_KERNEL);
-	if (!page_list)
-		return -ENOMEM;
-
 	if (msg->perm & VHOST_ACCESS_WO)
 		gup_flags |= FOLL_WRITE;
 
@@ -614,61 +615,86 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 	if (!npages)
 		return -EINVAL;
 
+	page_list = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
+	vmas = kvmalloc_array(npages, sizeof(struct vm_area_struct *),
+			      GFP_KERNEL);
+	if (!page_list || !vmas) {
+		ret = -ENOMEM;
+		goto free;
+	}
+
 	mmap_read_lock(dev->mm);
 
-	locked = atomic64_add_return(npages, &dev->mm->pinned_vm);
 	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-
-	if (locked > lock_limit) {
+	if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) {
 		ret = -ENOMEM;
-		goto out;
+		goto unlock;
 	}
 
-	cur_base = msg->uaddr & PAGE_MASK;
-	iova &= PAGE_MASK;
+	pinned = pin_user_pages(msg->uaddr & PAGE_MASK, npages, gup_flags,
+				page_list, vmas);
+	if (npages != pinned) {
+		if (pinned < 0) {
+			ret = pinned;
+		} else {
+			unpin_user_pages(page_list, pinned);
+			ret = -ENOMEM;
+		}
+		goto unlock;
+	}
 
-	while (npages) {
-		pinned = min_t(unsigned long, npages, list_size);
-		ret = pin_user_pages(cur_base, pinned,
-				     gup_flags, page_list, NULL);
-		if (ret != pinned)
-			goto out;
-
-		if (!last_pfn)
-			map_pfn = page_to_pfn(page_list[0]);
-
-		for (i = 0; i < ret; i++) {
-			unsigned long this_pfn = page_to_pfn(page_list[i]);
-			u64 csize;
-
-			if (last_pfn && (this_pfn != last_pfn + 1)) {
-				/* Pin a contiguous chunk of memory */
-				csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
-				if (vhost_vdpa_map(v, iova, csize,
-						   map_pfn << PAGE_SHIFT,
-						   msg->perm))
-					goto out;
-				map_pfn = this_pfn;
-				iova += csize;
+	iova &= PAGE_MASK;
+	map_pfn = page_to_pfn(page_list[0]);
+
+	/* One more iteration to avoid extra vdpa_map() call out of loop. */
+	for (i = 0; i <= npages; i++) {
+		unsigned long this_pfn;
+		u64 csize;
+
+		/* The last chunk may have no valid PFN next to it */
+		this_pfn = i < npages ? page_to_pfn(page_list[i]) : -1UL;
+
+		if (last_pfn && (this_pfn == -1UL ||
+				 this_pfn != last_pfn + 1)) {
+			/* Pin a contiguous chunk of memory */
+			csize = last_pfn - map_pfn + 1;
+			ret = vhost_vdpa_map(v, iova, csize << PAGE_SHIFT,
+					     map_pfn << PAGE_SHIFT,
+					     msg->perm);
+			if (ret) {
+				/*
+				 * Unpin the rest chunks of memory on the
+				 * flight with no corresponding vdpa_map()
+				 * calls having been made yet. On the other
+				 * hand, vdpa_unmap() in the failure path
+				 * is in charge of accounting the number of
+				 * pinned pages for its own.
+				 * This asymmetrical pattern of accounting
+				 * is for efficiency to pin all pages at
+				 * once, while there is no other callsite
+				 * of vdpa_map() than here above.
+				 */
+				unpin_user_pages(&page_list[nmap],
+						 npages - nmap);
+				goto out;
 			}
-
-			last_pfn = this_pfn;
+			atomic64_add(csize, &dev->mm->pinned_vm);
+			nmap += csize;
+			iova += csize << PAGE_SHIFT;
+			map_pfn = this_pfn;
 		}
-
-		cur_base += ret << PAGE_SHIFT;
-		npages -= ret;
+		last_pfn = this_pfn;
 	}
 
-	/* Pin the rest chunk */
-	ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
-			     map_pfn << PAGE_SHIFT, msg->perm);
+	WARN_ON(nmap != npages);
 out:
-	if (ret) {
+	if (ret)
 		vhost_vdpa_unmap(v, msg->iova, msg->size);
-		atomic64_sub(npages, &dev->mm->pinned_vm);
-	}
+unlock:
 	mmap_read_unlock(dev->mm);
-	free_page((unsigned long)page_list);
+free:
+	kvfree(vmas);
+	kvfree(page_list);
 	return ret;
 }
 
@@ -810,6 +836,7 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 
 err_init_iotlb:
 	vhost_dev_cleanup(&v->vdev);
+	kfree(vqs);
 err:
 	atomic_dec(&v->opened);
 	return r;