Re: [dpdk-dev] [PATCH v3 18/21] net/virtio: add support for mergeable buffers with packed virtqueues

[Maxime Coquelin]

Maybe better to place this patch right after the non-mrg one.

On 04/05/2018 12:10 PM, Jens Freimann wrote:

Implement support for receiving merged buffers in virtio when packed virtqueues
are enabled.

Signed-off-by: Jens Freimann <jfreim...@redhat.com>
---
  drivers/net/virtio/virtio_ethdev.c |  10 ++--
  drivers/net/virtio/virtio_rxtx.c   | 107 +++++++++++++++++++++++++++++++++----
  drivers/net/virtio/virtqueue.h     |   1 +
  3 files changed, 104 insertions(+), 14 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c 
b/drivers/net/virtio/virtio_ethdev.c
index 7367d9c5d..a3c3376d7 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1322,15 +1322,15 @@ set_rxtx_funcs(struct rte_eth_dev *eth_dev)
  {
        struct virtio_hw *hw = eth_dev->data->dev_private;

- /* workarount for packed vqs which don't support mrg_rxbuf at this point */

-       if (vtpci_packed_queue(hw) && vtpci_with_feature(hw, 
VIRTIO_NET_F_MRG_RXBUF)) {
-               eth_dev->rx_pkt_burst = &virtio_recv_pkts_packed;
-       } else if (hw->use_simple_rx) {
+       if (hw->use_simple_rx) {
                PMD_INIT_LOG(INFO, "virtio: using simple Rx path on port %u",
                        eth_dev->data->port_id);
                eth_dev->rx_pkt_burst = virtio_recv_pkts_vec;
        } else if (vtpci_packed_queue(hw)) {
-               eth_dev->rx_pkt_burst = &virtio_recv_pkts_packed;
+               if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF))
+                       eth_dev->rx_pkt_burst = &virtio_recv_mergeable_pkts;
+               else
+                       eth_dev->rx_pkt_burst = &virtio_recv_pkts_packed;
        } else if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
                PMD_INIT_LOG(INFO,
                        "virtio: using mergeable buffer Rx path on port %u",
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 9220ae661..a48ca6aaa 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -155,8 +155,8 @@ vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
        vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs);
        if ((dp->flags & VRING_DESC_F_INDIRECT) == 0) {
                while (dp->flags & VRING_DESC_F_NEXT) {
-                       desc_idx_last = dp->next;
-                       dp = &vq->vq_ring.desc[dp->next];
+                       desc_idx_last = desc_idx++;
+                       dp = &vq->vq_ring.desc[desc_idx];

Are you sure this change is in the right patch?

                }
        }
        dxp->ndescs = 0;
@@ -177,6 +177,76 @@ vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
        dp->next = VQ_RING_DESC_CHAIN_END;
  }