[dpdk-dev] [PATCH v1 04/14] vhost: simplify async IO vectors iterators

[Maxime Coquelin <maxime.coquelin@redhat.com>]

This patch splits the iterator arrays in two, one for
source and one for destination. The goal is make the code
easier to understand.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vhost.h      |  5 +++--
 lib/vhost/virtio_net.c | 24 ++++++++++++------------
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index f2d9535174..cb4c0f022a 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -48,7 +48,7 @@
 
 #define MAX_PKT_BURST 32
 
-#define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST * 2)
+#define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST)
 #define VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 2)
 
 #define PACKED_DESC_ENQUEUE_USED_FLAG(w)	\
@@ -132,7 +132,8 @@ struct vhost_async {
 	/* operation callbacks for DMA */
 	struct rte_vhost_async_channel_ops ops;
 
-	struct rte_vhost_iov_iter it_pool[VHOST_MAX_ASYNC_IT];
+	struct rte_vhost_iov_iter src_iov_iter[VHOST_MAX_ASYNC_IT];
+	struct rte_vhost_iov_iter dst_iov_iter[VHOST_MAX_ASYNC_IT];
 	struct iovec src_iovec[VHOST_MAX_ASYNC_VEC];
 	struct iovec dst_iovec[VHOST_MAX_ASYNC_VEC];
 
diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index 4e0e1584b8..e2a9e138b7 100644
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -1511,7 +1511,8 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 	uint16_t avail_head;
 
 	struct vhost_async *async = vq->async;
-	struct rte_vhost_iov_iter *it_pool = async->it_pool;
+	struct rte_vhost_iov_iter *src_iter = async->src_iov_iter;
+	struct rte_vhost_iov_iter *dst_iter = async->dst_iov_iter;
 	struct rte_vhost_async_desc tdes[MAX_PKT_BURST];
 	struct iovec *src_iovec = async->src_iovec;
 	struct iovec *dst_iovec = async->dst_iovec;
@@ -1547,20 +1548,19 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 
 		if (async_mbuf_to_desc(dev, vq, pkts[pkt_idx], buf_vec, nr_vec, num_buffers,
 				&src_iovec[iovec_idx], &dst_iovec[iovec_idx],
-				&it_pool[it_idx], &it_pool[it_idx + 1]) < 0) {
+				&src_iter[it_idx], &dst_iter[it_idx]) < 0) {
 			vq->shadow_used_idx -= num_buffers;
 			break;
 		}
 
-		async_fill_desc(&tdes[pkt_burst_idx++], &it_pool[it_idx],
-				&it_pool[it_idx + 1]);
+		async_fill_desc(&tdes[pkt_burst_idx++], &src_iter[it_idx], &dst_iter[it_idx]);
 
 		slot_idx = (async->pkts_idx + pkt_idx) & (vq->size - 1);
 		pkts_info[slot_idx].descs = num_buffers;
 		pkts_info[slot_idx].mbuf = pkts[pkt_idx];
 
-		iovec_idx += it_pool[it_idx].nr_segs;
-		it_idx += 2;
+		iovec_idx += src_iter[it_idx].nr_segs;
+		it_idx++;
 
 		vq->last_avail_idx += num_buffers;
 
@@ -1829,7 +1829,8 @@ virtio_dev_rx_async_submit_packed(struct virtio_net *dev,
 	uint16_t num_descs;
 
 	struct vhost_async *async = vq->async;
-	struct rte_vhost_iov_iter *it_pool = async->it_pool;
+	struct rte_vhost_iov_iter *src_iter = async->src_iov_iter;
+	struct rte_vhost_iov_iter *dst_iter = async->dst_iov_iter;
 	struct rte_vhost_async_desc tdes[MAX_PKT_BURST];
 	struct iovec *src_iovec = async->src_iovec;
 	struct iovec *dst_iovec = async->dst_iovec;
@@ -1846,18 +1847,17 @@ virtio_dev_rx_async_submit_packed(struct virtio_net *dev,
 		if (unlikely(virtio_dev_rx_async_packed(dev, vq, pkts[pkt_idx],
 						&num_descs, &num_buffers,
 						&src_iovec[iovec_idx], &dst_iovec[iovec_idx],
-						&it_pool[it_idx], &it_pool[it_idx + 1]) < 0))
+						&src_iter[it_idx], &dst_iter[it_idx]) < 0))
 			break;
 
 		slot_idx = (async->pkts_idx + pkt_idx) % vq->size;
 
-		async_fill_desc(&tdes[pkt_burst_idx++], &it_pool[it_idx],
-				&it_pool[it_idx + 1]);
+		async_fill_desc(&tdes[pkt_burst_idx++], &src_iter[it_idx], &dst_iter[it_idx]);
 		pkts_info[slot_idx].descs = num_descs;
 		pkts_info[slot_idx].nr_buffers = num_buffers;
 		pkts_info[slot_idx].mbuf = pkts[pkt_idx];
-		iovec_idx += it_pool[it_idx].nr_segs;
-		it_idx += 2;
+		iovec_idx += src_iter[it_idx].nr_segs;
+		it_idx++;
 
 		pkt_idx++;
 		remained--;
-- 
2.31.1