vhost: create descriptor mapping function

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Tiwei Bie <tiwei.bie@intel.com>

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 4b7d91d..98ef770 100644 (file)
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -291,6 +291,40 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
        }
 }
 
+static __rte_always_inline int
+map_one_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
+               struct buf_vector *buf_vec, uint16_t *vec_idx,
+               uint64_t desc_iova, uint64_t desc_len, uint8_t perm)
+{
+       uint16_t vec_id = *vec_idx;
+
+       while (desc_len) {
+               uint64_t desc_addr;
+               uint64_t desc_chunck_len = desc_len;
+
+               if (unlikely(vec_id >= BUF_VECTOR_MAX))
+                       return -1;
+
+               desc_addr = vhost_iova_to_vva(dev, vq,
+                               desc_iova,
+                               &desc_chunck_len,
+                               perm);
+               if (unlikely(!desc_addr))
+                       return -1;
+
+               buf_vec[vec_id].buf_iova = desc_iova;
+               buf_vec[vec_id].buf_addr = desc_addr;
+               buf_vec[vec_id].buf_len  = desc_chunck_len;
+
+               desc_len -= desc_chunck_len;
+               desc_iova += desc_chunck_len;
+               vec_id++;
+       }
+       *vec_idx = vec_id;
+
+       return 0;
+}
+
 static __rte_always_inline int
 fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
                         uint32_t avail_idx, uint16_t *vec_idx,
@@ -300,7 +334,7 @@ fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
        uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
        uint16_t vec_id = *vec_idx;
        uint32_t len    = 0;
-       uint64_t dlen, desc_avail, desc_iova;
+       uint64_t dlen;
        struct vring_desc *descs = vq->desc;
        struct vring_desc *idesc = NULL;
 
@@ -337,37 +371,13 @@ fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
                        return -1;
                }
 
-
                len += descs[idx].len;
-               desc_avail = descs[idx].len;
-               desc_iova = descs[idx].addr;
-
-               while (desc_avail) {
-                       uint64_t desc_addr;
-                       uint64_t desc_chunck_len = desc_avail;
-
-                       if (unlikely(vec_id >= BUF_VECTOR_MAX)) {
-                               free_ind_table(idesc);
-                               return -1;
-                       }
 
-                       desc_addr = vhost_iova_to_vva(dev, vq,
-                                       desc_iova,
-                                       &desc_chunck_len,
-                                       perm);
-                       if (unlikely(!desc_addr)) {
-                               free_ind_table(idesc);
-                               return -1;
-                       }
-
-                       buf_vec[vec_id].buf_iova = desc_iova;
-                       buf_vec[vec_id].buf_addr = desc_addr;
-                       buf_vec[vec_id].buf_len  = desc_chunck_len;
-                       buf_vec[vec_id].desc_idx = idx;
-
-                       desc_avail -= desc_chunck_len;
-                       desc_iova += desc_chunck_len;
-                       vec_id++;
+               if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
+                                               descs[idx].addr, descs[idx].len,
+                                               perm))) {
+                       free_ind_table(idesc);
+                       return -1;
                }
 
                if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0)