Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull vhost fixes from Michael Tsirkin:
 "Some last minute vhost,vdpa fixes.

  The last two of them haven't been in next but they do seem kind of
  obvious, very small and safe, fix bugs reported in the field, and they
  are both in a new mlx5 vdpa driver, so it's not like we can introduce
  regressions"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vdpa/mlx5: Fix dependency on MLX5_CORE
  vdpa/mlx5: should keep avail_index despite device status
  vhost-vdpa: fix page pinning leakage in error path
  vhost-vdpa: fix vhost_vdpa_map() on error condition
  vhost: Don't call log_access_ok() when using IOTLB
  vhost: Use vhost_get_used_size() in vhost_vring_set_addr()
  vhost: Don't call access_ok() when using IOTLB
  vhost vdpa: fix vhost_vdpa_open error handling

drivers/vdpa/Kconfig

@@ -30,9 +30,7 @@ config IFCVF
 	  be called ifcvf.
 
 config MLX5_VDPA
-	bool "MLX5 VDPA support library for ConnectX devices"
-	depends on MLX5_CORE
-	default n
+	bool
 	help
 	  Support library for Mellanox VDPA drivers. Provides code that is
 	  common for all types of VDPA drivers. The following drivers are planned:
@@ -40,7 +38,8 @@ config MLX5_VDPA
 
 config MLX5_VDPA_NET
 	tristate "vDPA driver for ConnectX devices"
-	depends on MLX5_VDPA
+	select MLX5_VDPA
+	depends on MLX5_CORE
 	default n
 	help
 	  VDPA network driver for ConnectX6 and newer. Provides offloading

drivers/vdpa/mlx5/net/mlx5_vnet.c

@@ -1133,15 +1133,17 @@ static void suspend_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *m
 	if (!mvq->initialized)
 		return;
 
-	if (query_virtqueue(ndev, mvq, &attr)) {
-		mlx5_vdpa_warn(&ndev->mvdev, "failed to query virtqueue\n");
-		return;
-	}
 	if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY)
 		return;
 
 	if (modify_virtqueue(ndev, mvq, MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND))
 		mlx5_vdpa_warn(&ndev->mvdev, "modify to suspend failed\n");
+
+	if (query_virtqueue(ndev, mvq, &attr)) {
+		mlx5_vdpa_warn(&ndev->mvdev, "failed to query virtqueue\n");
+		return;
+	}
+	mvq->avail_idx = attr.available_index;
 }
 
 static void suspend_vqs(struct mlx5_vdpa_net *ndev)
@@ -1411,8 +1413,14 @@ static int mlx5_vdpa_get_vq_state(struct vdpa_device *vdev, u16 idx, struct vdpa
 	struct mlx5_virtq_attr attr;
 	int err;
 
-	if (!mvq->initialized)
-		return -EAGAIN;
+	/* If the virtq object was destroyed, use the value saved at
+	 * the last minute of suspend_vq. This caters for userspace
+	 * that cares about emulating the index after vq is stopped.
+	 */
+	if (!mvq->initialized) {
+		state->avail_index = mvq->avail_idx;
+		return 0;
+	}
 
 	err = query_virtqueue(ndev, mvq, &attr);
 	if (err) {

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;

drivers/vhost/vhost.c

@@ -1290,6 +1290,11 @@ static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
 			 vring_used_t __user *used)
 
 {
+	/* If an IOTLB device is present, the vring addresses are
+	 * GIOVAs. Access validation occurs at prefetch time. */
+	if (vq->iotlb)
+		return true;
+
 	return access_ok(desc, vhost_get_desc_size(vq, num)) &&
 	       access_ok(avail, vhost_get_avail_size(vq, num)) &&
 	       access_ok(used, vhost_get_used_size(vq, num));
@@ -1365,6 +1370,20 @@ bool vhost_log_access_ok(struct vhost_dev *dev)
 }
 EXPORT_SYMBOL_GPL(vhost_log_access_ok);
 
+static bool vq_log_used_access_ok(struct vhost_virtqueue *vq,
+				  void __user *log_base,
+				  bool log_used,
+				  u64 log_addr)
+{
+	/* If an IOTLB device is present, log_addr is a GIOVA that
+	 * will never be logged by log_used(). */
+	if (vq->iotlb)
+		return true;
+
+	return !log_used || log_access_ok(log_base, log_addr,
+					  vhost_get_used_size(vq, vq->num));
+}
+
 /* Verify access for write logging. */
 /* Caller should have vq mutex and device mutex */
 static bool vq_log_access_ok(struct vhost_virtqueue *vq,
@@ -1372,8 +1391,7 @@ static bool vq_log_access_ok(struct vhost_virtqueue *vq,
 {
 	return vq_memory_access_ok(log_base, vq->umem,
 				   vhost_has_feature(vq, VHOST_F_LOG_ALL)) &&
-		(!vq->log_used || log_access_ok(log_base, vq->log_addr,
-				  vhost_get_used_size(vq, vq->num)));
+		vq_log_used_access_ok(vq, log_base, vq->log_used, vq->log_addr);
 }
 
 /* Can we start vq? */
@@ -1383,10 +1401,6 @@ bool vhost_vq_access_ok(struct vhost_virtqueue *vq)
 	if (!vq_log_access_ok(vq, vq->log_base))
 		return false;
 
-	/* Access validation occurs at prefetch time with IOTLB */
-	if (vq->iotlb)
-		return true;
-
 	return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used);
 }
 EXPORT_SYMBOL_GPL(vhost_vq_access_ok);
@@ -1516,10 +1530,9 @@ static long vhost_vring_set_addr(struct vhost_dev *d,
 			return -EINVAL;
 
 		/* Also validate log access for used ring if enabled. */
-		if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) &&
-			!log_access_ok(vq->log_base, a.log_guest_addr,
-				sizeof *vq->used +
-				vq->num * sizeof *vq->used->ring))
+		if (!vq_log_used_access_ok(vq, vq->log_base,
+				a.flags & (0x1 << VHOST_VRING_F_LOG),
+				a.log_guest_addr))
 			return -EINVAL;
 	}