[dpdk-dev] [PATCH v5 4/4] lib_vhost: Remove unnecessary vring descriptor length updating

[Ouyang Changchun <changchun.ouyang@intel.com>]

Remove these unnecessary vring descriptor length updating, vhost should not change them.
virtio in front end should assign value to desc.len for both rx and tx.

Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
---
 lib/librte_vhost/vhost_rxtx.c | 18 +-----------------
 1 file changed, 1 insertion(+), 17 deletions(-)

diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index 5c31a88..07bc16c 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -137,7 +137,6 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 		 */
 		if ((desc->flags & VRING_DESC_F_NEXT) &&
 			(desc->len == vq->vhost_hlen)) {
-			desc->len = vq->vhost_hlen;
 			desc = &vq->desc[desc->next];
 			/* Buffer address translation. */
 			buff_addr = gpa_to_vva(dev, desc->addr);
@@ -291,7 +290,6 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint16_t res_base_idx,
 	if (vb_avail == 0) {
 		uint32_t desc_idx =
 			vq->buf_vec[vec_idx].desc_idx;
-		vq->desc[desc_idx].len = vq->vhost_hlen;
 
 		if ((vq->desc[desc_idx].flags
 			& VRING_DESC_F_NEXT) == 0) {
@@ -375,7 +373,6 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint16_t res_base_idx,
 					 */
 					uint32_t desc_idx =
 						vq->buf_vec[vec_idx].desc_idx;
-					vq->desc[desc_idx].len = vb_offset;
 
 					if ((vq->desc[desc_idx].flags &
 						VRING_DESC_F_NEXT) == 0) {
@@ -410,26 +407,13 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint16_t res_base_idx,
 				/*
 				 * This whole packet completes.
 				 */
-				uint32_t desc_idx =
-					vq->buf_vec[vec_idx].desc_idx;
-				vq->desc[desc_idx].len = vb_offset;
-
-				while (vq->desc[desc_idx].flags &
-					VRING_DESC_F_NEXT) {
-					desc_idx = vq->desc[desc_idx].next;
-					 vq->desc[desc_idx].len = 0;
-				}
-
 				/* Update used ring with desc information */
 				vq->used->ring[cur_idx & (vq->size - 1)].id
 					= vq->buf_vec[vec_idx].desc_idx;
 				vq->used->ring[cur_idx & (vq->size - 1)].len
 					= entry_len;
-				entry_len = 0;
-				cur_idx++;
 				entry_success++;
-				seg_avail = 0;
-				cpy_len = RTE_MIN(vb_avail, seg_avail);
+				break;
 			}
 		}
 	}
-- 
1.8.4.2