vhost: prepare sync for mbuf to descriptor refactoring

This patch extracts the descriptors buffers filling
from copy_mbuf_to_desc() into a dedicated function as a
preliminary step of merging copy_mubf_to_desc() and
async_mbuf_to_desc().

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Jiayu Hu <jiayu.hu@intel.com>

diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index a901e29..e36468d 100644 (file)
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -894,6 +894,30 @@ async_mbuf_to_desc_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
        return 0;
 }
 
+static __rte_always_inline void
+sync_mbuf_to_desc_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
+               struct rte_mbuf *m, uint32_t mbuf_offset,
+               uint64_t buf_addr, uint64_t buf_iova, uint32_t cpy_len)
+{
+       struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
+
+       if (likely(cpy_len > MAX_BATCH_LEN || vq->batch_copy_nb_elems >= vq->size)) {
+               rte_memcpy((void *)((uintptr_t)(buf_addr)),
+                               rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
+                               cpy_len);
+               vhost_log_cache_write_iova(dev, vq, buf_iova, cpy_len);
+               PRINT_PACKET(dev, (uintptr_t)(buf_addr), cpy_len, 0);
+       } else {
+               batch_copy[vq->batch_copy_nb_elems].dst =
+                       (void *)((uintptr_t)(buf_addr));
+               batch_copy[vq->batch_copy_nb_elems].src =
+                       rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
+               batch_copy[vq->batch_copy_nb_elems].log_addr = buf_iova;
+               batch_copy[vq->batch_copy_nb_elems].len = cpy_len;
+               vq->batch_copy_nb_elems++;
+       }
+}
+
 static __rte_always_inline int
 copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
                            struct rte_mbuf *m, struct buf_vector *buf_vec,
@@ -906,23 +930,17 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
        uint32_t cpy_len;
        uint64_t hdr_addr;
        struct rte_mbuf *hdr_mbuf;
-       struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
        struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL;
-       int error = 0;
 
-       if (unlikely(m == NULL)) {
-               error = -1;
-               goto out;
-       }
+       if (unlikely(m == NULL))
+               return -1;
 
        buf_addr = buf_vec[vec_idx].buf_addr;
        buf_iova = buf_vec[vec_idx].buf_iova;
        buf_len = buf_vec[vec_idx].buf_len;
 
-       if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) {
-               error = -1;
-               goto out;
-       }
+       if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1))
+               return -1;
 
        hdr_mbuf = m;
        hdr_addr = buf_addr;
@@ -953,10 +971,8 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
                /* done with current buf, get the next one */
                if (buf_avail == 0) {
                        vec_idx++;
-                       if (unlikely(vec_idx >= nr_vec)) {
-                               error = -1;
-                               goto out;
-                       }
+                       if (unlikely(vec_idx >= nr_vec))
+                               goto error;
 
                        buf_addr = buf_vec[vec_idx].buf_addr;
                        buf_iova = buf_vec[vec_idx].buf_iova;
@@ -995,26 +1011,9 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 
                cpy_len = RTE_MIN(buf_avail, mbuf_avail);
 
-               if (likely(cpy_len > MAX_BATCH_LEN ||
-                                       vq->batch_copy_nb_elems >= vq->size)) {
-                       rte_memcpy((void *)((uintptr_t)(buf_addr + buf_offset)),
-                               rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
-                               cpy_len);
-                       vhost_log_cache_write_iova(dev, vq,
-                                                  buf_iova + buf_offset,
-                                                  cpy_len);
-                       PRINT_PACKET(dev, (uintptr_t)(buf_addr + buf_offset),
-                               cpy_len, 0);
-               } else {
-                       batch_copy[vq->batch_copy_nb_elems].dst =
-                               (void *)((uintptr_t)(buf_addr + buf_offset));
-                       batch_copy[vq->batch_copy_nb_elems].src =
-                               rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
-                       batch_copy[vq->batch_copy_nb_elems].log_addr =
-                               buf_iova + buf_offset;
-                       batch_copy[vq->batch_copy_nb_elems].len = cpy_len;
-                       vq->batch_copy_nb_elems++;
-               }
+               sync_mbuf_to_desc_seg(dev, vq, m, mbuf_offset,
+                               buf_addr + buf_offset,
+                               buf_iova + buf_offset, cpy_len);
 
                mbuf_avail  -= cpy_len;
                mbuf_offset += cpy_len;
@@ -1022,9 +1021,9 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
                buf_offset += cpy_len;
        }
 
-out:
-
-       return error;
+       return 0;
+error:
+       return -1;
 }
 
 static __rte_always_inline int