vhost: simplify async IO vectors iterators

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>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
Reviewed-by: Jiayu Hu <jiayu.hu@intel.com>

diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index b0bad495e1efbd987da70aa64cdc707b2827b27f..3238a271c8c7ea7f8804ec3ef0432c567e7f4dd9 100644 (file)
--- 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 2a243701c06c0dc91318f55457c1e37ebe8923ed..f0d923704af6528be95e2c130b819474c0621f89 100644 (file)
--- 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--;