[dpdk-dev] [PATCH v4 07/14] vhost: add flush function for batch enqueue

[Marvin Liu]

Flush used flags when batched enqueue function is finished. Descriptor's
flags are pre-calculated as they will be reset by vhost.

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

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 18a207fc6..7bf9ff9b7 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_RX_USED_FLAG  (0ULL | VRING_DESC_F_AVAIL | VRING_DESC_F_USED \
+                               | VRING_DESC_F_WRITE)
+#define PACKED_RX_USED_WRAP_FLAG (VRING_DESC_F_WRITE)
 #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 f85619dc2..a629e66d4 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -169,6 +169,49 @@ update_shadow_used_ring_packed(struct vhost_virtqueue *vq,
        vq->shadow_used_packed[i].count = count;
 }
 
+static __rte_always_inline void
+flush_used_batch_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
+       uint64_t *lens, uint16_t *ids, uint16_t flags)
+{
+       uint16_t i;
+
+       UNROLL_PRAGMA(UNROLL_PRAGMA_PARAM)
+       for (i = 0; i < PACKED_BATCH_SIZE; i++) {
+               vq->desc_packed[vq->last_used_idx + i].id = ids[i];
+               vq->desc_packed[vq->last_used_idx + i].len = lens[i];
+       }
+
+       rte_smp_wmb();
+       UNROLL_PRAGMA(UNROLL_PRAGMA_PARAM)
+       for (i = 0; i < PACKED_BATCH_SIZE; i++)
+               vq->desc_packed[vq->last_used_idx + i].flags = flags;
+
+       vhost_log_cache_used_vring(dev, vq, vq->last_used_idx *
+                                  sizeof(struct vring_packed_desc),
+                                  sizeof(struct vring_packed_desc) *
+                                  PACKED_BATCH_SIZE);
+       vhost_log_cache_sync(dev, vq);
+
+       vq->last_used_idx += PACKED_BATCH_SIZE;
+       if (vq->last_used_idx >= vq->size) {
+               vq->used_wrap_counter ^= 1;
+               vq->last_used_idx -= vq->size;
+       }
+}
+
+static __rte_always_inline void
+flush_enqueue_batch_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
+       uint64_t *lens, uint16_t *ids)
+{
+       uint16_t flags = 0;
+
+       if (vq->used_wrap_counter)
+               flags = PACKED_RX_USED_FLAG;
+       else
+               flags = PACKED_RX_USED_WRAP_FLAG;
+       flush_used_batch_packed(dev, vq, lens, ids, flags);
+}
+
 static __rte_always_inline void
 update_enqueue_shadow_used_ring_packed(struct vhost_virtqueue *vq,
        uint16_t desc_idx, uint32_t len, uint16_t count)
@@ -937,6 +980,7 @@ virtio_dev_rx_batch_packed(struct virtio_net *dev, struct 
vhost_virtqueue *vq,
        struct virtio_net_hdr_mrg_rxbuf *hdrs[PACKED_BATCH_SIZE];
        uint32_t buf_offset = dev->vhost_hlen;
        uint64_t lens[PACKED_BATCH_SIZE];
+       uint16_t ids[PACKED_BATCH_SIZE];
        uint16_t i;
 
        if (unlikely(avail_idx & PACKED_BATCH_MASK))
@@ -1003,6 +1047,12 @@ virtio_dev_rx_batch_packed(struct virtio_net *dev, 
struct vhost_virtqueue *vq,
                           pkts[i]->pkt_len);
        }
 
+       UNROLL_PRAGMA(UNROLL_PRAGMA_PARAM)
+       for (i = 0; i < PACKED_BATCH_SIZE; i++)
+               ids[i] = descs[avail_idx + i].id;
+
+       flush_enqueue_batch_packed(dev, vq, lens, ids);
+
        return 0;
 }
 
-- 
2.17.1