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

[Maxime Coquelin <maxime.coquelin@redhat.com>]

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 <jfreimann@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;
>   }
>