X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=lib%2Flibrte_vhost%2Fvirtio_net.c;h=b779034dca83b9f50f67763858960acefc605c08;hb=9253c34cfb9dd32faeb8e513f6d8fafd356a2e62;hp=a05d44fdb8319adc268f0e3837454b4f5d113cb8;hpb=6b3c81db8bb7427dc69402a25018781a689bd37a;p=dpdk.git

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index a05d44fdb8..b779034dca 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -222,8 +222,9 @@ vhost_flush_dequeue_shadow_packed(struct virtio_net *dev,
 	struct vring_used_elem_packed *used_elem = &vq->shadow_used_packed[0];
 
 	vq->desc_packed[vq->shadow_last_used_idx].id = used_elem->id;
-	rte_smp_wmb();
-	vq->desc_packed[vq->shadow_last_used_idx].flags = used_elem->flags;
+	/* desc flags is the synchronization point for virtio packed vring */
+	__atomic_store_n(&vq->desc_packed[vq->shadow_last_used_idx].flags,
+			 used_elem->flags, __ATOMIC_RELEASE);
 
 	vhost_log_cache_used_vring(dev, vq, vq->shadow_last_used_idx *
 				   sizeof(struct vring_packed_desc),
@@ -1281,8 +1282,6 @@ virtio_dev_rx_batch_packed(struct virtio_net *dev,
 			return -1;
 	}
 
-	rte_smp_rmb();
-
 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
 		lens[i] = descs[avail_idx + i].len;
 
@@ -1343,7 +1342,6 @@ virtio_dev_rx_single_packed(struct virtio_net *dev,
 	struct buf_vector buf_vec[BUF_VECTOR_MAX];
 	uint16_t nr_descs = 0;
 
-	rte_smp_rmb();
 	if (unlikely(vhost_enqueue_single_packed(dev, vq, pkt, buf_vec,
 						 &nr_descs) < 0)) {
 		VHOST_LOG_DATA(DEBUG,
@@ -1491,18 +1489,16 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 	struct iovec *dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >> 1);
 	struct rte_vhost_iov_iter *src_it = it_pool;
 	struct rte_vhost_iov_iter *dst_it = it_pool + 1;
-	uint16_t n_free_slot, slot_idx;
+	uint16_t n_free_slot, slot_idx = 0;
 	uint16_t pkt_err = 0;
+	uint16_t segs_await = 0;
 	struct async_inflight_info *pkts_info = vq->async_pkts_info;
 	int n_pkts = 0;
 
-	avail_head = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE);
-
 	/*
-	 * The ordering between avail index and
-	 * desc reads needs to be enforced.
+	 * The ordering between avail index and desc reads need to be enforced.
 	 */
-	rte_smp_rmb();
+	avail_head = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE);
 
 	rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
 
@@ -1541,6 +1537,7 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 			dst_iovec += dst_it->nr_segs;
 			src_it += 2;
 			dst_it += 2;
+			segs_await += src_it->nr_segs;
 		} else {
 			pkts_info[slot_idx].info = num_buffers;
 			vq->async_pkts_inflight_n++;
@@ -1548,15 +1545,24 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 
 		vq->last_avail_idx += num_buffers;
 
+		/*
+		 * conditions to trigger async device transfer:
+		 * - buffered packet number reaches transfer threshold
+		 * - this is the last packet in the burst enqueue
+		 * - unused async iov number is less than max vhost vector
+		 */
 		if (pkt_burst_idx >= VHOST_ASYNC_BATCH_THRESHOLD ||
-				(pkt_idx == count - 1 && pkt_burst_idx)) {
+			(pkt_idx == count - 1 && pkt_burst_idx) ||
+			(VHOST_MAX_ASYNC_VEC / 2 - segs_await <
+			BUF_VECTOR_MAX)) {
 			n_pkts = vq->async_ops.transfer_data(dev->vid,
 					queue_id, tdes, 0, pkt_burst_idx);
 			src_iovec = vec_pool;
 			dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >> 1);
 			src_it = it_pool;
 			dst_it = it_pool + 1;
-			vq->async_pkts_inflight_n += n_pkts;
+			segs_await = 0;
+			vq->async_pkts_inflight_n += pkt_burst_idx;
 
 			if (unlikely(n_pkts < (int)pkt_burst_idx)) {
 				/*
@@ -1576,7 +1582,7 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 	if (pkt_burst_idx) {
 		n_pkts = vq->async_ops.transfer_data(dev->vid,
 				queue_id, tdes, 0, pkt_burst_idx);
-		vq->async_pkts_inflight_n += n_pkts;
+		vq->async_pkts_inflight_n += pkt_burst_idx;
 
 		if (unlikely(n_pkts < (int)pkt_burst_idx))
 			pkt_err = pkt_burst_idx - n_pkts;
@@ -1703,7 +1709,6 @@ virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
 {
 	struct vhost_virtqueue *vq;
 	uint32_t nb_tx = 0;
-	bool drawback = false;
 
 	VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
 	if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
@@ -1716,14 +1721,9 @@ virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
 
 	rte_spinlock_lock(&vq->access_lock);
 
-	if (unlikely(vq->enabled == 0))
+	if (unlikely(vq->enabled == 0 || !vq->async_registered))
 		goto out_access_unlock;
 
-	if (unlikely(!vq->async_registered)) {
-		drawback = true;
-		goto out_access_unlock;
-	}
-
 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 		vhost_user_iotlb_rd_lock(vq);
 
@@ -1749,9 +1749,6 @@ out:
 out_access_unlock:
 	rte_spinlock_unlock(&vq->access_lock);
 
-	if (drawback)
-		return rte_vhost_enqueue_burst(dev->vid, queue_id, pkts, count);
-
 	return nb_tx;
 }