vhost: use fixed virtio-net header length packed ring

This small optimization uses the static the Virtio-net
header len in packed datapath, since Virtio-net header
cannot be the legacy one in case of packed ring.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 008f5ce..1b23327 100644 (file)
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1147,7 +1147,7 @@ vhost_enqueue_single_packed(struct virtio_net *dev,
        uint16_t buf_id = 0;
        uint32_t len = 0;
        uint16_t desc_count;
-       uint32_t size = pkt->pkt_len + dev->vhost_hlen;
+       uint32_t size = pkt->pkt_len + sizeof(struct virtio_net_hdr_mrg_rxbuf);
        uint16_t num_buffers = 0;
        uint32_t buffer_len[vq->size];
        uint16_t buffer_buf_id[vq->size];
@@ -1262,7 +1262,7 @@ virtio_dev_rx_batch_packed(struct virtio_net *dev,
        uint16_t avail_idx = vq->last_avail_idx;
        uint64_t desc_addrs[PACKED_BATCH_SIZE];
        struct virtio_net_hdr_mrg_rxbuf *hdrs[PACKED_BATCH_SIZE];
-       uint32_t buf_offset = dev->vhost_hlen;
+       uint32_t buf_offset = sizeof(struct virtio_net_hdr_mrg_rxbuf);
        uint64_t lens[PACKED_BATCH_SIZE];
        uint16_t ids[PACKED_BATCH_SIZE];
        uint16_t i;
@@ -1308,7 +1308,8 @@ virtio_dev_rx_batch_packed(struct virtio_net *dev,
                rte_prefetch0((void *)(uintptr_t)desc_addrs[i]);
                hdrs[i] = (struct virtio_net_hdr_mrg_rxbuf *)
                                        (uintptr_t)desc_addrs[i];
-               lens[i] = pkts[i]->pkt_len + dev->vhost_hlen;
+               lens[i] = pkts[i]->pkt_len +
+                       sizeof(struct virtio_net_hdr_mrg_rxbuf);
        }
 
        vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
@@ -2263,7 +2264,7 @@ vhost_reserve_avail_batch_packed(struct virtio_net *dev,
        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;
+       uint32_t buf_offset = sizeof(struct virtio_net_hdr_mrg_rxbuf);
        uint16_t flags, i;
 
        if (unlikely(avail_idx & PACKED_BATCH_MASK))
@@ -2340,7 +2341,7 @@ virtio_dev_tx_batch_packed(struct virtio_net *dev,
                           struct rte_mbuf **pkts)
 {
        uint16_t avail_idx = vq->last_avail_idx;
-       uint32_t buf_offset = dev->vhost_hlen;
+       uint32_t buf_offset = sizeof(struct virtio_net_hdr_mrg_rxbuf);
        uintptr_t desc_addrs[PACKED_BATCH_SIZE];
        uint16_t ids[PACKED_BATCH_SIZE];
        uint16_t i;