[dpdk-dev] [PATCH v6 07/25] lib/librte_vhost: patch virtio_dev_merge_tx to return packets to upper layer

[Huawei Xie]

This patch makes virtio_dev_merge_tx return the received packets to  app layer.
Previously virtio_tx_route is called to route these packets and then free them.

Signed-off-by: Huawei Xie <huawei.xie at intel.com>
---
 lib/librte_vhost/vhost_rxtx.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index c9e3b1e..07fb085 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -512,8 +512,8 @@ virtio_dev_merge_rx(struct virtio_net *dev, struct rte_mbuf **pkts,
 }
 
 /* This function works for TX packets with mergeable feature enabled. */
-static inline void __attribute__((always_inline))
-virtio_dev_merge_tx(struct virtio_net *dev, struct rte_mempool *mbuf_pool)
+static uint16_t void __attribute__((always_inline))
+virtio_dev_merge_tx(struct virtio_net *dev, struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
 {
 	struct rte_mbuf *m, *prev;
 	struct vhost_virtqueue *vq;
@@ -532,7 +532,7 @@ virtio_dev_merge_tx(struct virtio_net *dev, struct rte_mempool *mbuf_pool)
 
 	/* If there are no available buffers then return. */
 	if (vq->last_used_idx == avail_idx)
-		return;
+		return 0;
 
 	LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_merge_tx()\n",
 		dev->device_fh);
@@ -543,6 +543,7 @@ virtio_dev_merge_tx(struct virtio_net *dev, struct rte_mempool *mbuf_pool)
 	/*get the number of free entries in the ring*/
 	free_entries = (avail_idx - vq->last_used_idx);
 
+	free_entries = RTE_MIN(free_entries, count);
 	/* Limit to MAX_PKT_BURST. */
 	free_entries = RTE_MIN(free_entries, MAX_PKT_BURST);
 
@@ -599,7 +600,7 @@ virtio_dev_merge_tx(struct virtio_net *dev, struct rte_mempool *mbuf_pool)
 		if (unlikely(m == NULL)) {
 			RTE_LOG(ERR, VHOST_DATA,
 				"Failed to allocate memory for mbuf.\n");
-			return;
+			return entry_success;
 		}
 
 		seg_num++;
@@ -701,9 +702,9 @@ virtio_dev_merge_tx(struct virtio_net *dev, struct rte_mempool *mbuf_pool)
 
 		m->nb_segs = seg_num;
 
+		pkts[entry_success] = m;
 		vq->last_used_idx++;
 		entry_success++;
-		rte_pktmbuf_free(m);
 	}
 
 	rte_compiler_barrier();
@@ -711,5 +712,6 @@ virtio_dev_merge_tx(struct virtio_net *dev, struct rte_mempool *mbuf_pool)
 	/* Kick guest if required. */
 	if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
 		eventfd_write((int)vq->kickfd, 1);
+	return entry_success;
 
 }
-- 
1.8.1.4