diff mbox series

[v4,1/4] vhost: abstract and reorganize async split ring code

Message ID 20210410102521.15806-3-Cheng1.jiang@intel.com (mailing list archive)
State Superseded
Headers show
Series [v4,1/4] vhost: abstract and reorganize async split ring code | expand

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Cheng Jiang April 10, 2021, 10:25 a.m. UTC
In order to improve code efficiency and readability when async packed
ring support is enabled. This patch abstract some functions like
shadow_ring_store and write_back_completed_descs_split. And improve
the efficiency of some pointer offset calculation.

Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
---
 lib/librte_vhost/virtio_net.c | 146 +++++++++++++++++++---------------
 1 file changed, 84 insertions(+), 62 deletions(-)
diff mbox series

Patch

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index ff3987860..69553e7c3 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1458,6 +1458,29 @@  virtio_dev_rx_async_get_info_idx(uint16_t pkts_idx,
 		(vq_size - n_inflight + pkts_idx) & (vq_size - 1);
 }
 
+static __rte_always_inline void
+shadow_ring_store(struct vhost_virtqueue *vq,  void *shadow_ring, void *d_ring,
+		uint16_t s_idx, uint16_t d_idx,
+		uint16_t count, uint16_t elem_size)
+{
+	if (s_idx + count <= vq->size) {
+		rte_memcpy((void *)((uintptr_t)d_ring + d_idx * elem_size),
+			(void *)((uintptr_t)shadow_ring + s_idx * elem_size),
+			count * elem_size);
+	} else {
+		uint16_t size = vq->size - d_idx;
+
+		rte_memcpy((void *)((uintptr_t)d_ring + d_idx * elem_size),
+			(void *)((uintptr_t)shadow_ring + s_idx * elem_size),
+			size * elem_size);
+
+		rte_memcpy((void *)((uintptr_t)d_ring),
+			(void *)((uintptr_t)shadow_ring +
+				(s_idx + size) * elem_size),
+			(count - size) * elem_size);
+	}
+}
+
 static __rte_noinline uint32_t
 virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 	struct vhost_virtqueue *vq, uint16_t queue_id,
@@ -1478,6 +1501,7 @@  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 	struct rte_vhost_iov_iter *dst_it = it_pool + 1;
 	uint16_t slot_idx = 0;
 	uint16_t segs_await = 0;
+	uint16_t iovec_idx = 0, it_idx = 0;
 	struct async_inflight_info *pkts_info = vq->async_pkts_info;
 	uint32_t n_pkts = 0, pkt_err = 0;
 	uint32_t num_async_pkts = 0, num_done_pkts = 0;
@@ -1513,27 +1537,32 @@  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, dst_iovec, src_it, dst_it) < 0) {
+				&src_iovec[iovec_idx],
+				&dst_iovec[iovec_idx],
+				&src_it[it_idx],
+				&dst_it[it_idx]) < 0) {
 			vq->shadow_used_idx -= num_buffers;
 			break;
 		}
 
 		slot_idx = (vq->async_pkts_idx + num_async_pkts) &
 			(vq->size - 1);
-		if (src_it->count) {
+		if (src_it[it_idx].count) {
 			uint16_t from, to;
 
-			async_fill_desc(&tdes[pkt_burst_idx++], src_it, dst_it);
+			async_fill_desc(&tdes[pkt_burst_idx++],
+				&src_it[it_idx],
+				&dst_it[it_idx]);
 			pkts_info[slot_idx].descs = num_buffers;
 			pkts_info[slot_idx].mbuf = pkts[pkt_idx];
 			async_pkts_log[num_async_pkts].pkt_idx = pkt_idx;
 			async_pkts_log[num_async_pkts++].last_avail_idx =
 				vq->last_avail_idx;
-			src_iovec += src_it->nr_segs;
-			dst_iovec += dst_it->nr_segs;
-			src_it += 2;
-			dst_it += 2;
-			segs_await += src_it->nr_segs;
+
+			iovec_idx += src_it[it_idx].nr_segs;
+			it_idx += 2;
+
+			segs_await += src_it[it_idx].nr_segs;
 
 			/**
 			 * recover shadow used ring and keep DMA-occupied
@@ -1541,23 +1570,12 @@  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 			 */
 			from = vq->shadow_used_idx - num_buffers;
 			to = vq->async_desc_idx & (vq->size - 1);
-			if (num_buffers + to <= vq->size) {
-				rte_memcpy(&vq->async_descs_split[to],
-						&vq->shadow_used_split[from],
-						num_buffers *
-						sizeof(struct vring_used_elem));
-			} else {
-				int size = vq->size - to;
-
-				rte_memcpy(&vq->async_descs_split[to],
-						&vq->shadow_used_split[from],
-						size *
-						sizeof(struct vring_used_elem));
-				rte_memcpy(vq->async_descs_split,
-						&vq->shadow_used_split[from +
-						size], (num_buffers - size) *
-					   sizeof(struct vring_used_elem));
-			}
+
+			shadow_ring_store(vq, vq->shadow_used_split,
+					vq->async_descs_split,
+					from, to, num_buffers,
+					sizeof(struct vring_used_elem));
+
 			vq->async_desc_idx += num_buffers;
 			vq->shadow_used_idx -= num_buffers;
 		} else
@@ -1575,10 +1593,9 @@  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 			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;
+			iovec_idx = 0;
+			it_idx = 0;
+
 			segs_await = 0;
 			vq->async_pkts_inflight_n += n_pkts;
 
@@ -1639,6 +1656,43 @@  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 	return pkt_idx;
 }
 
+static __rte_always_inline void
+write_back_completed_descs_split(struct vhost_virtqueue *vq, uint16_t n_descs)
+{
+	uint16_t nr_left = n_descs;
+	uint16_t nr_copy;
+	uint16_t to, from;
+
+	do {
+		from = vq->last_async_desc_idx & (vq->size - 1);
+		nr_copy = nr_left + from <= vq->size ? nr_left :
+			vq->size - from;
+		to = vq->last_used_idx & (vq->size - 1);
+
+		if (to + nr_copy <= vq->size) {
+			rte_memcpy(&vq->used->ring[to],
+					&vq->async_descs_split[from],
+					nr_copy *
+					sizeof(struct vring_used_elem));
+		} else {
+			uint16_t size = vq->size - to;
+
+			rte_memcpy(&vq->used->ring[to],
+					&vq->async_descs_split[from],
+					size *
+					sizeof(struct vring_used_elem));
+			rte_memcpy(vq->used->ring,
+					&vq->async_descs_split[from +
+					size], (nr_copy - size) *
+					sizeof(struct vring_used_elem));
+		}
+
+		vq->last_async_desc_idx += nr_copy;
+		vq->last_used_idx += nr_copy;
+		nr_left -= nr_copy;
+	} while (nr_left > 0);
+}
+
 uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
 		struct rte_mbuf **pkts, uint16_t count)
 {
@@ -1695,39 +1749,7 @@  uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
 	vq->async_pkts_inflight_n -= n_pkts_put;
 
 	if (likely(vq->enabled && vq->access_ok)) {
-		uint16_t nr_left = n_descs;
-		uint16_t nr_copy;
-		uint16_t to;
-
-		/* write back completed descriptors to used ring */
-		do {
-			from = vq->last_async_desc_idx & (vq->size - 1);
-			nr_copy = nr_left + from <= vq->size ? nr_left :
-				vq->size - from;
-			to = vq->last_used_idx & (vq->size - 1);
-
-			if (to + nr_copy <= vq->size) {
-				rte_memcpy(&vq->used->ring[to],
-						&vq->async_descs_split[from],
-						nr_copy *
-						sizeof(struct vring_used_elem));
-			} else {
-				uint16_t size = vq->size - to;
-
-				rte_memcpy(&vq->used->ring[to],
-						&vq->async_descs_split[from],
-						size *
-						sizeof(struct vring_used_elem));
-				rte_memcpy(vq->used->ring,
-						&vq->async_descs_split[from +
-						size], (nr_copy - size) *
-						sizeof(struct vring_used_elem));
-			}
-
-			vq->last_async_desc_idx += nr_copy;
-			vq->last_used_idx += nr_copy;
-			nr_left -= nr_copy;
-		} while (nr_left > 0);
+		write_back_completed_descs_split(vq, n_descs);
 
 		__atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
 		vhost_vring_call_split(dev, vq);