Re: [dpdk-dev] [PATCH v7 5/8] net/virtio: implement transmit path for packed queues

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

On 10/03/2018 03:11 PM, Jens Freimann wrote:
> This implements the transmit path for devices with
> support for packed virtqueues.
> 
> Signed-off-by: Jens Freiman <jfreimann@redhat.com>
> ---
>   drivers/net/virtio/virtio_ethdev.c |  32 ++--
>   drivers/net/virtio/virtio_ethdev.h |   2 +
>   drivers/net/virtio/virtio_ring.h   |  15 +-
>   drivers/net/virtio/virtio_rxtx.c   | 276 +++++++++++++++++++++++++++++
>   drivers/net/virtio/virtqueue.h     |  18 +-
>   5 files changed, 329 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index d6a1613dd..c65ac365c 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -390,6 +390,8 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
>   	vq->hw = hw;
>   	vq->vq_queue_index = vtpci_queue_idx;
>   	vq->vq_nentries = vq_size;
> +	if (vtpci_packed_queue(hw))
> +		vq->vq_ring.avail_wrap_counter = 1;
>   
>   	/*
>   	 * Reserve a memzone for vring elements
> @@ -496,16 +498,22 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
>   		memset(txr, 0, vq_size * sizeof(*txr));
>   		for (i = 0; i < vq_size; i++) {
>   			struct vring_desc *start_dp = txr[i].tx_indir;
> -
> -			vring_desc_init_split(start_dp, RTE_DIM(txr[i].tx_indir));
> -
> +			struct vring_desc_packed*start_dp_packed = txr[i].tx_indir_pq;
> +	
>   			/* first indirect descriptor is always the tx header */
> -			start_dp->addr = txvq->virtio_net_hdr_mem
> -				+ i * sizeof(*txr)
> -				+ offsetof(struct virtio_tx_region, tx_hdr);
> -
> -			start_dp->len = hw->vtnet_hdr_size;
> -			start_dp->flags = VRING_DESC_F_NEXT;
> +			if (vtpci_packed_queue(hw)) {
No need to init desc here?

> +				start_dp_packed->addr = txvq->virtio_net_hdr_mem
> +					+ i * sizeof(*txr)
> +					+ offsetof(struct virtio_tx_region, tx_hdr);
> +				start_dp_packed->len = hw->vtnet_hdr_size;
> +			} else {
> +				vring_desc_init_split(start_dp, RTE_DIM(txr[i].tx_indir));
> +				start_dp->addr = txvq->virtio_net_hdr_mem
> +					+ i * sizeof(*txr)
> +					+ offsetof(struct virtio_tx_region, tx_hdr);
> +				start_dp->len = hw->vtnet_hdr_size;
> +				start_dp->flags = VRING_DESC_F_NEXT;
> +			}
>   		}
>   	}
>   
> @@ -1344,7 +1352,11 @@ set_rxtx_funcs(struct rte_eth_dev *eth_dev)
>   		eth_dev->rx_pkt_burst = &virtio_recv_pkts;
>   	}
>   
> -	if (hw->use_inorder_tx) {
> +	if (vtpci_packed_queue(hw)) {
> +		PMD_INIT_LOG(INFO, "virtio: using virtio 1.1 Tx path on port %u",
> +			eth_dev->data->port_id);
> +		eth_dev->tx_pkt_burst = virtio_xmit_pkts_packed;
> +	} else if (hw->use_inorder_tx) {
>   		PMD_INIT_LOG(INFO, "virtio: using inorder Tx path on port %u",
>   			eth_dev->data->port_id);
>   		eth_dev->tx_pkt_burst = virtio_xmit_pkts_inorder;
> diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
> index e0f80e5a4..05d355180 100644
> --- a/drivers/net/virtio/virtio_ethdev.h
> +++ b/drivers/net/virtio/virtio_ethdev.h
> @@ -82,6 +82,8 @@ uint16_t virtio_recv_mergeable_pkts_inorder(void *rx_queue,
>   
>   uint16_t virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
>   		uint16_t nb_pkts);
> +uint16_t virtio_xmit_pkts_packed(void *tx_queue, struct rte_mbuf **tx_pkts,
> +		uint16_t nb_pkts);
>   
>   uint16_t virtio_xmit_pkts_inorder(void *tx_queue, struct rte_mbuf **tx_pkts,
>   		uint16_t nb_pkts);
> diff --git a/drivers/net/virtio/virtio_ring.h b/drivers/net/virtio/virtio_ring.h
> index b9e63d4d4..dbffd4dcd 100644
> --- a/drivers/net/virtio/virtio_ring.h
> +++ b/drivers/net/virtio/virtio_ring.h
> @@ -108,14 +108,25 @@ set_desc_avail(struct vring *vr, struct vring_desc_packed *desc)
>   }
>   
>   static inline int
> -desc_is_used(struct vring_desc_packed *desc, struct vring *vr)
> +_desc_is_used(struct vring_desc_packed *desc)
>   {
>   	uint16_t used, avail;
>   
>   	used = !!(desc->flags & VRING_DESC_F_USED(1));
>   	avail = !!(desc->flags & VRING_DESC_F_AVAIL(1));
>   
> -	return used == avail && used == vr->used_wrap_counter;
> +	return used == avail;
> +
> +}
> +
> +static inline int
> +desc_is_used(struct vring_desc_packed *desc, struct vring *vr)
> +{
> +	uint16_t used;
> +
> +	used = !!(desc->flags & VRING_DESC_F_USED(1));
> +
> +	return _desc_is_used(desc) && used == vr->used_wrap_counter;
>   }

This is not in the right patch.

>   /* The standard layout for the ring is a continuous chunk of memory which
> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
> index eb891433e..4078fba8e 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -38,6 +38,7 @@
>   #define  VIRTIO_DUMP_PACKET(m, len) do { } while (0)
>   #endif
>   
> +

Remove trailing line.

I need to review the remaining, but you can work on above comments in
the mean time.

Regards,
Maxime