[dpdk-dev] [PATCH v6 06/13] vhost: add packed ring batch dequeue

Marvin Liu yong.liu at intel.com
Tue Oct 15 18:07:32 CEST 2019


Add batch dequeue function like enqueue function for packed ring, batch
dequeue function will not support chained descritpors, single packet
dequeue function will handle it.

Signed-off-by: Marvin Liu <yong.liu at intel.com>

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 18d01cb19..96bf763b1 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -39,6 +39,9 @@
 
 #define VHOST_LOG_CACHE_NR 32
 
+#define PACKED_DESC_SINGLE_DEQUEUE_FLAG (VRING_DESC_F_NEXT | \
+					 VRING_DESC_F_INDIRECT)
+
 #define PACKED_BATCH_SIZE (RTE_CACHE_LINE_SIZE / \
 			    sizeof(struct vring_packed_desc))
 #define PACKED_BATCH_MASK (PACKED_BATCH_SIZE - 1)
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index e1b06c1ce..274a28f99 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1551,6 +1551,113 @@ virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
 	return i;
 }
 
+static __rte_always_inline int
+vhost_reserve_avail_batch_packed(struct virtio_net *dev,
+				 struct vhost_virtqueue *vq,
+				 struct rte_mempool *mbuf_pool,
+				 struct rte_mbuf **pkts,
+				 uint16_t avail_idx,
+				 uintptr_t *desc_addrs,
+				 uint16_t *ids)
+{
+	bool wrap = vq->avail_wrap_counter;
+	struct vring_packed_desc *descs = vq->desc_packed;
+	struct virtio_net_hdr *hdr;
+	uint64_t lens[PACKED_BATCH_SIZE];
+	uint64_t buf_lens[PACKED_BATCH_SIZE];
+	uint32_t buf_offset = dev->vhost_hlen;
+	uint16_t flags, i;
+
+	if (unlikely(avail_idx & PACKED_BATCH_MASK))
+		return -1;
+	if (unlikely((avail_idx + PACKED_BATCH_SIZE) > vq->size))
+		return -1;
+
+	for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+		flags = descs[avail_idx + i].flags;
+		if (unlikely((wrap != !!(flags & VRING_DESC_F_AVAIL)) ||
+			     (wrap == !!(flags & VRING_DESC_F_USED))  ||
+			     (flags & PACKED_DESC_SINGLE_DEQUEUE_FLAG)))
+			return -1;
+	}
+
+	rte_smp_rmb();
+
+	for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+		lens[i] = descs[avail_idx + i].len;
+
+	for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+		desc_addrs[i] = vhost_iova_to_vva(dev, vq,
+						  descs[avail_idx + i].addr,
+						  &lens[i], VHOST_ACCESS_RW);
+	}
+
+	for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+		if (unlikely((lens[i] != descs[avail_idx + i].len)))
+			return -1;
+	}
+
+	if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts, PACKED_BATCH_SIZE))
+		return -1;
+
+	for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+		buf_lens[i] = pkts[i]->buf_len - pkts[i]->data_off;
+
+	for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+		if (unlikely(buf_lens[i] < (lens[i] - buf_offset)))
+			goto free_buf;
+	}
+
+	for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+		pkts[i]->pkt_len = descs[avail_idx + i].len - buf_offset;
+		pkts[i]->data_len = pkts[i]->pkt_len;
+		ids[i] = descs[avail_idx + i].id;
+	}
+
+	if (virtio_net_with_host_offload(dev)) {
+		for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+			hdr = (struct virtio_net_hdr *)(desc_addrs[i]);
+			vhost_dequeue_offload(hdr, pkts[i]);
+		}
+	}
+
+	return 0;
+
+free_buf:
+	for (i = 0; i < PACKED_BATCH_SIZE; i++)
+		rte_pktmbuf_free(pkts[i]);
+
+	return -1;
+}
+
+static __rte_unused int
+virtio_dev_tx_batch_packed(struct virtio_net *dev,
+			   struct vhost_virtqueue *vq,
+			   struct rte_mempool *mbuf_pool,
+			   struct rte_mbuf **pkts)
+{
+	uint16_t avail_idx = vq->last_avail_idx;
+	uint32_t buf_offset = dev->vhost_hlen;
+	uintptr_t desc_addrs[PACKED_BATCH_SIZE];
+	uint16_t ids[PACKED_BATCH_SIZE];
+	uint16_t i;
+
+	if (vhost_reserve_avail_batch_packed(dev, vq, mbuf_pool, pkts,
+					     avail_idx, desc_addrs, ids))
+		return -1;
+
+	for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+		rte_prefetch0((void *)(uintptr_t)desc_addrs[i]);
+		rte_memcpy(rte_pktmbuf_mtod_offset(pkts[i], void *, 0),
+			   (void *)(uintptr_t)(desc_addrs[i] + buf_offset),
+			   pkts[i]->pkt_len);
+	}
+
+	vq_inc_last_avail_packed(vq, PACKED_BATCH_SIZE);
+
+	return 0;
+}
+
 static __rte_always_inline int
 vhost_dequeue_single_packed(struct virtio_net *dev,
 			    struct vhost_virtqueue *vq,
-- 
2.17.1



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