[dpdk-dev] [PATCH v3 08/11] net/virtio: add in-order Rx/Tx into selection

[Maxime Coquelin]

On 06/28/2018 11:52 PM, Marvin Liu wrote:
> After IN_ORDER Rx/Tx paths added, need to update Rx/Tx path selection
> logic.
> 
> Rx path select logic: If IN_ORDER is disabled will select normal Rx
> path. If IN_ORDER is enabled, Rx offload and merge-able are disabled
> will select simple Rx path. Otherwise will select IN_ORDER Rx path.
> 
> Tx path select logic: If IN_ORDER is disabled will select normal Tx
> path. If IN_ORDER is enabled and merge-able is disabled will select
> simple Tx path. Otherwise will select IN_ORDER Tx path.
> 
> Signed-off-by: Marvin Liu <yong.liu at intel.com>
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index df50a571a..2b3d65f80 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -1320,6 +1320,11 @@ set_rxtx_funcs(struct rte_eth_dev *eth_dev)
>   		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 (hw->use_inorder_rx) {
> +		PMD_INIT_LOG(INFO,
> +			"virtio: using inorder mergeable buffer Rx path on port %u",
> +			eth_dev->data->port_id);
> +		eth_dev->rx_pkt_burst = &virtio_recv_mergeable_pkts_inorder;
>   	} else if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
>   		PMD_INIT_LOG(INFO,
>   			"virtio: using mergeable buffer Rx path on port %u",
> @@ -1335,6 +1340,10 @@ set_rxtx_funcs(struct rte_eth_dev *eth_dev)
>   		PMD_INIT_LOG(INFO, "virtio: using simple Tx path on port %u",
>   			eth_dev->data->port_id);
>   		eth_dev->tx_pkt_burst = virtio_xmit_pkts_simple;
> +	} 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;
>   	} else {
>   		PMD_INIT_LOG(INFO, "virtio: using standard Tx path on port %u",
>   			eth_dev->data->port_id);
> @@ -1871,24 +1880,24 @@ virtio_dev_configure(struct rte_eth_dev *dev)
>   
>   	rte_spinlock_init(&hw->state_lock);
>   
> -	hw->use_simple_rx = 1;
> -	hw->use_simple_tx = 1;
> -
>   #if defined RTE_ARCH_ARM64 || defined RTE_ARCH_ARM
>   	if (!rte_cpu_get_flag_enabled(RTE_CPUFLAG_NEON)) {
>   		hw->use_simple_rx = 0;
>   		hw->use_simple_tx = 0;
>   	}
>   #endif
> -	if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
> -		hw->use_simple_rx = 0;
> -		hw->use_simple_tx = 0;
> +	if (vtpci_with_feature(hw, VIRTIO_F_IN_ORDER)) {
> +		if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
> +			hw->use_inorder_rx = 1;
> +			hw->use_inorder_tx = 1;
> +		} else {
> +			hw->use_simple_tx = 1;
> +			if (!(rx_offloads & (DEV_RX_OFFLOAD_UDP_CKSUM |
> +					     DEV_RX_OFFLOAD_TCP_CKSUM)))
> +				hw->use_simple_rx = 1;
> +		}

It seems to be wrong.
For example if IN_ORDER hasn't been negotiated, we might want to use the 
simple path if no rx offload have been requested by the application.

It was the case before the patch if I'm not mistaken.

Also, with ARM platform, we force not to use simple path, but in case
IN_ORDER has been negotiated but not MRG_RXBUF, it gets re-enabled.

>   	}
>   
> -	if (rx_offloads & (DEV_RX_OFFLOAD_UDP_CKSUM |
> -			   DEV_RX_OFFLOAD_TCP_CKSUM))
> -		hw->use_simple_rx = 0;
> -
>   	return 0;
>   }
>   
>