diff mbox series

[RFC,3/6] vringh: support VA with iotlb

Message ID 20221214163025.103075-4-sgarzare@redhat.com (mailing list archive)
State New, archived
Headers show
Series vdpa_sim: add support for user VA | expand

Commit Message

Stefano Garzarella Dec. 14, 2022, 4:30 p.m. UTC
vDPA supports the possibility to use user VA in the iotlb messages.
So, let's add support for user VA in vringh to use it in the vDPA
simulators.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 include/linux/vringh.h             |   5 +-
 drivers/vdpa/mlx5/core/resources.c |   3 +-
 drivers/vdpa/mlx5/net/mlx5_vnet.c  |   2 +-
 drivers/vdpa/vdpa_sim/vdpa_sim.c   |   4 +-
 drivers/vhost/vringh.c             | 250 +++++++++++++++++++++++------
 5 files changed, 207 insertions(+), 57 deletions(-)
diff mbox series

Patch

diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index 212892cf9822..c70962f16b1f 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -32,6 +32,9 @@  struct vringh {
 	/* Can we get away with weak barriers? */
 	bool weak_barriers;
 
+	/* Use user's VA */
+	bool use_va;
+
 	/* Last available index we saw (ie. where we're up to). */
 	u16 last_avail_idx;
 
@@ -279,7 +282,7 @@  void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb,
 		      spinlock_t *iotlb_lock);
 
 int vringh_init_iotlb(struct vringh *vrh, u64 features,
-		      unsigned int num, bool weak_barriers,
+		      unsigned int num, bool weak_barriers, bool use_va,
 		      struct vring_desc *desc,
 		      struct vring_avail *avail,
 		      struct vring_used *used);
diff --git a/drivers/vdpa/mlx5/core/resources.c b/drivers/vdpa/mlx5/core/resources.c
index 9800f9bec225..e0bab3458b40 100644
--- a/drivers/vdpa/mlx5/core/resources.c
+++ b/drivers/vdpa/mlx5/core/resources.c
@@ -233,7 +233,8 @@  static int init_ctrl_vq(struct mlx5_vdpa_dev *mvdev)
 	if (!mvdev->cvq.iotlb)
 		return -ENOMEM;
 
-	vringh_set_iotlb(&mvdev->cvq.vring, mvdev->cvq.iotlb, &mvdev->cvq.iommu_lock);
+	vringh_set_iotlb(&mvdev->cvq.vring, mvdev->cvq.iotlb,
+			 &mvdev->cvq.iommu_lock);
 
 	return 0;
 }
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 90913365def4..81ba0867e2c8 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -2504,7 +2504,7 @@  static int setup_cvq_vring(struct mlx5_vdpa_dev *mvdev)
 
 	if (mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ))
 		err = vringh_init_iotlb(&cvq->vring, mvdev->actual_features,
-					MLX5_CVQ_MAX_ENT, false,
+					MLX5_CVQ_MAX_ENT, false, false,
 					(struct vring_desc *)(uintptr_t)cvq->desc_addr,
 					(struct vring_avail *)(uintptr_t)cvq->driver_addr,
 					(struct vring_used *)(uintptr_t)cvq->device_addr);
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index b20689f8fe89..2e0ee7280aa8 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -67,7 +67,7 @@  static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
 {
 	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 
-	vringh_init_iotlb(&vq->vring, vdpasim->features, vq->num, false,
+	vringh_init_iotlb(&vq->vring, vdpasim->features, vq->num, false, false,
 			  (struct vring_desc *)(uintptr_t)vq->desc_addr,
 			  (struct vring_avail *)
 			  (uintptr_t)vq->driver_addr,
@@ -87,7 +87,7 @@  static void vdpasim_vq_reset(struct vdpasim *vdpasim,
 	vq->cb = NULL;
 	vq->private = NULL;
 	vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
-			  VDPASIM_QUEUE_MAX, false, NULL, NULL, NULL);
+			  VDPASIM_QUEUE_MAX, false, false, NULL, NULL, NULL);
 
 	vq->vring.notify = NULL;
 }
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 11f59dd06a74..c1f77dc93482 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -1094,15 +1094,99 @@  EXPORT_SYMBOL(vringh_need_notify_kern);
 
 #if IS_REACHABLE(CONFIG_VHOST_IOTLB)
 
-static int iotlb_translate(const struct vringh *vrh,
-			   u64 addr, u64 len, u64 *translated,
-			   struct bio_vec iov[],
-			   int iov_size, u32 perm)
+static int iotlb_translate_va(const struct vringh *vrh,
+			      u64 addr, u64 len, u64 *translated,
+			      struct iovec iov[],
+			      int iov_size, u32 perm)
 {
 	struct vhost_iotlb_map *map;
 	struct vhost_iotlb *iotlb = vrh->iotlb;
+	u64 s = 0, last = addr + len - 1;
+	int ret = 0;
+
+	spin_lock(vrh->iotlb_lock);
+
+	while (len > s) {
+		u64 size;
+
+		if (unlikely(ret >= iov_size)) {
+			ret = -ENOBUFS;
+			break;
+		}
+
+		map = vhost_iotlb_itree_first(iotlb, addr, last);
+		if (!map || map->start > addr) {
+			ret = -EINVAL;
+			break;
+		} else if (!(map->perm & perm)) {
+			ret = -EPERM;
+			break;
+		}
+
+		size = map->size - addr + map->start;
+		iov[ret].iov_len = min(len - s, size);
+		iov[ret].iov_base = (void __user *)(unsigned long)
+				    (map->addr + addr - map->start);
+		s += size;
+		addr += size;
+		++ret;
+	}
+
+	spin_unlock(vrh->iotlb_lock);
+
+	if (translated)
+		*translated = min(len, s);
+
+	return ret;
+}
+
+static inline int copy_from_va(const struct vringh *vrh, void *dst, void *src,
+			       u64 len, u64 *translated)
+{
+	struct iovec iov[16];
+	struct iov_iter iter;
+	int ret;
+
+	ret = iotlb_translate_va(vrh, (u64)(uintptr_t)src, len, translated, iov,
+				 ARRAY_SIZE(iov), VHOST_MAP_RO);
+	if (ret == -ENOBUFS)
+		ret = ARRAY_SIZE(iov);
+	else if (ret < 0)
+		return ret;
+
+	iov_iter_init(&iter, READ, iov, ret, *translated);
+
+	return copy_from_iter(dst, *translated, &iter);
+}
+
+static inline int copy_to_va(const struct vringh *vrh, void *dst, void *src,
+			     u64 len, u64 *translated)
+{
+	struct iovec iov[16];
+	struct iov_iter iter;
+	int ret;
+
+	ret = iotlb_translate_va(vrh, (u64)(uintptr_t)dst, len, translated, iov,
+				 ARRAY_SIZE(iov), VHOST_MAP_WO);
+	if (ret == -ENOBUFS)
+		ret = ARRAY_SIZE(iov);
+	else if (ret < 0)
+		return ret;
+
+	iov_iter_init(&iter, WRITE, iov, ret, *translated);
+
+	return copy_to_iter(src, *translated, &iter);
+}
+
+static int iotlb_translate_pa(const struct vringh *vrh,
+			      u64 addr, u64 len, u64 *translated,
+			      struct bio_vec iov[],
+			      int iov_size, u32 perm)
+{
+	struct vhost_iotlb_map *map;
+	struct vhost_iotlb *iotlb = vrh->iotlb;
+	u64 s = 0, last = addr + len - 1;
 	int ret = 0;
-	u64 s = 0;
 
 	spin_lock(vrh->iotlb_lock);
 
@@ -1114,8 +1198,7 @@  static int iotlb_translate(const struct vringh *vrh,
 			break;
 		}
 
-		map = vhost_iotlb_itree_first(iotlb, addr,
-					      addr + len - 1);
+		map = vhost_iotlb_itree_first(iotlb, addr, last);
 		if (!map || map->start > addr) {
 			ret = -EINVAL;
 			break;
@@ -1143,28 +1226,61 @@  static int iotlb_translate(const struct vringh *vrh,
 	return ret;
 }
 
+static inline int copy_from_pa(const struct vringh *vrh, void *dst, void *src,
+			       u64 len, u64 *translated)
+{
+	struct bio_vec iov[16];
+	struct iov_iter iter;
+	int ret;
+
+	ret = iotlb_translate_pa(vrh, (u64)(uintptr_t)src, len, translated, iov,
+				 ARRAY_SIZE(iov), VHOST_MAP_RO);
+	if (ret == -ENOBUFS)
+		ret = ARRAY_SIZE(iov);
+	else if (ret < 0)
+		return ret;
+
+	iov_iter_bvec(&iter, READ, iov, ret, *translated);
+
+	return copy_from_iter(dst, *translated, &iter);
+}
+
+static inline int copy_to_pa(const struct vringh *vrh, void *dst, void *src,
+			     u64 len, u64 *translated)
+{
+	struct bio_vec iov[16];
+	struct iov_iter iter;
+	int ret;
+
+	ret = iotlb_translate_pa(vrh, (u64)(uintptr_t)dst, len, translated, iov,
+				 ARRAY_SIZE(iov), VHOST_MAP_WO);
+	if (ret == -ENOBUFS)
+		ret = ARRAY_SIZE(iov);
+	else if (ret < 0)
+		return ret;
+
+	iov_iter_bvec(&iter, WRITE, iov, ret, *translated);
+
+	return copy_to_iter(src, *translated, &iter);
+}
+
 static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
 				  void *src, size_t len)
 {
 	u64 total_translated = 0;
 
 	while (total_translated < len) {
-		struct bio_vec iov[16];
-		struct iov_iter iter;
 		u64 translated;
 		int ret;
 
-		ret = iotlb_translate(vrh, (u64)(uintptr_t)src,
-				      len - total_translated, &translated,
-				      iov, ARRAY_SIZE(iov), VHOST_MAP_RO);
-		if (ret == -ENOBUFS)
-			ret = ARRAY_SIZE(iov);
-		else if (ret < 0)
-			return ret;
-
-		iov_iter_bvec(&iter, READ, iov, ret, translated);
+		if (vrh->use_va) {
+			ret = copy_from_va(vrh, dst, src,
+					   len - total_translated, &translated);
+		} else {
+			ret = copy_from_pa(vrh, dst, src,
+					   len - total_translated, &translated);
+		}
 
-		ret = copy_from_iter(dst, translated, &iter);
 		if (ret < 0)
 			return ret;
 
@@ -1182,22 +1298,17 @@  static inline int copy_to_iotlb(const struct vringh *vrh, void *dst,
 	u64 total_translated = 0;
 
 	while (total_translated < len) {
-		struct bio_vec iov[16];
-		struct iov_iter iter;
 		u64 translated;
 		int ret;
 
-		ret = iotlb_translate(vrh, (u64)(uintptr_t)dst,
-				      len - total_translated, &translated,
-				      iov, ARRAY_SIZE(iov), VHOST_MAP_WO);
-		if (ret == -ENOBUFS)
-			ret = ARRAY_SIZE(iov);
-		else if (ret < 0)
-			return ret;
-
-		iov_iter_bvec(&iter, WRITE, iov, ret, translated);
+		if (vrh->use_va) {
+			ret = copy_to_va(vrh, dst, src,
+					 len - total_translated, &translated);
+		} else {
+			ret = copy_to_pa(vrh, dst, src,
+					 len - total_translated, &translated);
+		}
 
-		ret = copy_to_iter(src, translated, &iter);
 		if (ret < 0)
 			return ret;
 
@@ -1212,20 +1323,36 @@  static inline int copy_to_iotlb(const struct vringh *vrh, void *dst,
 static inline int getu16_iotlb(const struct vringh *vrh,
 			       u16 *val, const __virtio16 *p)
 {
-	struct bio_vec iov;
-	void *kaddr, *from;
 	int ret;
 
 	/* Atomic read is needed for getu16 */
-	ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), NULL,
-			      &iov, 1, VHOST_MAP_RO);
-	if (ret < 0)
-		return ret;
+	if (vrh->use_va) {
+		struct iovec iov;
+
+		ret = iotlb_translate_va(vrh, (u64)(uintptr_t)p, sizeof(*p),
+					 NULL, &iov, 1, VHOST_MAP_RO);
+		if (ret < 0)
+			return ret;
 
-	kaddr = kmap_atomic(iov.bv_page);
-	from = kaddr + iov.bv_offset;
-	*val = vringh16_to_cpu(vrh, READ_ONCE(*(__virtio16 *)from));
-	kunmap_atomic(kaddr);
+		ret = __get_user(*val, (__virtio16 *)iov.iov_base);
+		if (ret)
+			return ret;
+
+		*val = vringh16_to_cpu(vrh, *val);
+	} else {
+		struct bio_vec iov;
+		void *kaddr, *from;
+
+		ret = iotlb_translate_pa(vrh, (u64)(uintptr_t)p, sizeof(*p),
+					 NULL, &iov, 1, VHOST_MAP_RO);
+		if (ret < 0)
+			return ret;
+
+		kaddr = kmap_atomic(iov.bv_page);
+		from = kaddr + iov.bv_offset;
+		*val = vringh16_to_cpu(vrh, READ_ONCE(*(__virtio16 *)from));
+		kunmap_atomic(kaddr);
+	}
 
 	return 0;
 }
@@ -1233,20 +1360,36 @@  static inline int getu16_iotlb(const struct vringh *vrh,
 static inline int putu16_iotlb(const struct vringh *vrh,
 			       __virtio16 *p, u16 val)
 {
-	struct bio_vec iov;
-	void *kaddr, *to;
 	int ret;
 
 	/* Atomic write is needed for putu16 */
-	ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), NULL,
-			      &iov, 1, VHOST_MAP_WO);
-	if (ret < 0)
-		return ret;
+	if (vrh->use_va) {
+		struct iovec iov;
 
-	kaddr = kmap_atomic(iov.bv_page);
-	to = kaddr + iov.bv_offset;
-	WRITE_ONCE(*(__virtio16 *)to, cpu_to_vringh16(vrh, val));
-	kunmap_atomic(kaddr);
+		ret = iotlb_translate_va(vrh, (u64)(uintptr_t)p, sizeof(*p),
+					 NULL, &iov, 1, VHOST_MAP_RO);
+		if (ret < 0)
+			return ret;
+
+		val = cpu_to_vringh16(vrh, val);
+
+		ret = __put_user(val, (__virtio16 *)iov.iov_base);
+		if (ret)
+			return ret;
+	} else {
+		struct bio_vec iov;
+		void *kaddr, *to;
+
+		ret = iotlb_translate_pa(vrh, (u64)(uintptr_t)p, sizeof(*p), NULL,
+					 &iov, 1, VHOST_MAP_WO);
+		if (ret < 0)
+			return ret;
+
+		kaddr = kmap_atomic(iov.bv_page);
+		to = kaddr + iov.bv_offset;
+		WRITE_ONCE(*(__virtio16 *)to, cpu_to_vringh16(vrh, val));
+		kunmap_atomic(kaddr);
+	}
 
 	return 0;
 }
@@ -1308,6 +1451,7 @@  static inline int putused_iotlb(const struct vringh *vrh,
  * @features: the feature bits for this ring.
  * @num: the number of elements.
  * @weak_barriers: true if we only need memory barriers, not I/O.
+ * @use_va: true if IOTLB contains user VA
  * @desc: the userpace descriptor pointer.
  * @avail: the userpace avail pointer.
  * @used: the userpace used pointer.
@@ -1315,11 +1459,13 @@  static inline int putused_iotlb(const struct vringh *vrh,
  * Returns an error if num is invalid.
  */
 int vringh_init_iotlb(struct vringh *vrh, u64 features,
-		      unsigned int num, bool weak_barriers,
+		      unsigned int num, bool weak_barriers, bool use_va,
 		      struct vring_desc *desc,
 		      struct vring_avail *avail,
 		      struct vring_used *used)
 {
+	vrh->use_va = use_va;
+
 	return vringh_init_kern(vrh, features, num, weak_barriers,
 				desc, avail, used);
 }