[dpdk-dev] [PATCH v5 8/9] net/virtio: add in-order Rx/Tx into selection

[Maxime Coquelin]

On 07/02/2018 01:24 PM, Maxime Coquelin wrote:
> 
> 
> On 07/02/2018 03:56 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 and merge-able are enabled will select
>> IN_ORDER Rx path. If IN_ORDER is enabled, Rx offload and merge-able are
>> disabled will select simple Rx path. Otherwise will select normal Rx
>> path.
>>
>> Tx path select logic: If IN_ORDER is enabled will select IN_ORDER Tx
>> path. Otherwise will select default Tx path.
>>
>> Signed-off-by: Marvin Liu <yong.liu at intel.com>
>> Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
>>
>> diff --git a/doc/guides/nics/virtio.rst b/doc/guides/nics/virtio.rst
>> index 46e292c4d..7c099fb7c 100644
>> --- a/doc/guides/nics/virtio.rst
>> +++ b/doc/guides/nics/virtio.rst
>> @@ -201,7 +201,7 @@ The packet transmission flow is:
>>   Virtio PMD Rx/Tx Callbacks
>>   --------------------------
>> -Virtio driver has 3 Rx callbacks and 2 Tx callbacks.
>> +Virtio driver has 4 Rx callbacks and 3 Tx callbacks.
>>   Rx callbacks:
>> @@ -215,6 +215,9 @@ Rx callbacks:
>>      Vector version without mergeable Rx buffer support, also fixes 
>> the available
>>      ring indexes and uses vector instructions to optimize performance.
>> +#. ``virtio_recv_mergeable_pkts_inorder``:
>> +   In-order version with mergeable Rx buffer support.
>> +
>>   Tx callbacks:
>>   #. ``virtio_xmit_pkts``:
>> @@ -223,6 +226,8 @@ Tx callbacks:
>>   #. ``virtio_xmit_pkts_simple``:
>>      Vector version fixes the available ring indexes to optimize 
>> performance.
>> +#. ``virtio_xmit_pkts_inorder``:
>> +   In-order version.
>>   By default, the non-vector callbacks are used:
>> @@ -254,6 +259,12 @@ Example of using the vector version of the virtio 
>> poll mode driver in
>>      testpmd -l 0-2 -n 4 -- -i --tx-offloads=0x0 --rxq=1 --txq=1 
>> --nb-cores=1
>> +In-order callbacks only work on simulated virtio user vdev.
>> +
>> +*   For Rx: If mergeable Rx buffers is enabled and in-order is 
>> enabled then
>> +    ``virtio_xmit_pkts_inorder`` is used.
>> +
>> +*   For Tx: If in-order is enabled then ``virtio_xmit_pkts_inorder`` 
>> is used.
>>   Interrupt mode
>>   --------------
>> diff --git a/drivers/net/virtio/virtio_ethdev.c 
>> b/drivers/net/virtio/virtio_ethdev.c
>> index df50a571a..df7981ddb 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);
>> @@ -1874,20 +1883,27 @@ virtio_dev_configure(struct rte_eth_dev *dev)
>>       hw->use_simple_rx = 1;
>>       hw->use_simple_tx = 1;
>> +    if (vtpci_with_feature(hw, VIRTIO_F_IN_ORDER)) {
>> +        /* Simple Tx not compatible with in-order ring */
>> +        hw->use_inorder_tx = 1;
>> +        hw->use_simple_tx = 0;
>> +        if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
>> +            hw->use_inorder_rx = 1;
>> +            hw->use_simple_rx = 0;
>> +        } else {
>> +            hw->use_inorder_rx = 0;
>> +            if (rx_offloads & (DEV_RX_OFFLOAD_UDP_CKSUM |
>> +                       DEV_RX_OFFLOAD_TCP_CKSUM))
>> +                hw->use_simple_rx = 0;
> It is applied, but I think this is still not good.
> 
> Simple Rx is set to 1 by default, so if IN_ORDER isn't negotiated,
> and UDP/TCP_CSUM is enabled, simple Rx keeps being selected.
> 
> I'll fix it in my series that I'm doing on top.

Actually, after discussion with Ferruh, I fixed it directly in the patch.

Thanks,
Maxime

> Regards,
> Maxime
> 
>> +        }
>> +    }
>> +
>>   #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 (rx_offloads & (DEV_RX_OFFLOAD_UDP_CKSUM |
>> -               DEV_RX_OFFLOAD_TCP_CKSUM))
>> -        hw->use_simple_rx = 0;
>>       return 0;
>>   }
>>