Re: [dpdk-dev] [PATCH 1/3] app/testpmd: update Rx offload after setting MTU sccessfully

["Wei Hu (Xavier)" <xavier_huwei@163.com>]

Hi, Ferruh Yigit

On 2020/2/12 8:25, Wei Hu (Xavier) wrote:
> Hi, Ferruh Yigit
> 
> On 2020/1/28 19:27, Ferruh Yigit wrote:
>> On 1/21/2020 11:44 AM, Wei Hu (Xavier) wrote:
>>> From: "Wei Hu (Xavier)" <xavier.huwei@huawei.com>
>>>
>>> Currently, Rx offload capabilities and max_rx_pkt_len in the struct
>>> variable named rte_port are not updated after setting mtu successfully
>>> in port_mtu_set function by 'port config mtu <port_id> <value>' command.
>>> This may lead to reconfig mtu to the initial value in the driver when
>>> recalling rte_eth_dev_configure API interface.
>>>
>>> This patch updates Rx offload capabilities and max_rx_pkt_len after
>>> setting mtu successfully when configuring mtu.
>>>
>>> Fixes: ae03d0d18adf ("app/testpmd: command to configure MTU")
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Huisong Li <lihuisong@huawei.com>
>>> Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
>>> ---
>>>   app/test-pmd/config.c | 18 +++++++++++++++++-
>>>   1 file changed, 17 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
>>> index 9669cbd4c..09a1579f5 100644
>>> --- a/app/test-pmd/config.c
>>> +++ b/app/test-pmd/config.c
>>> @@ -1216,7 +1216,9 @@ void
>>>   port_mtu_set(portid_t port_id, uint16_t mtu)
>>>   {
>>>       int diag;
>>> +    struct rte_port *rte_port = &ports[port_id];
>>>       struct rte_eth_dev_info dev_info;
>>> +    uint16_t eth_overhead;
>>>       int ret;
>>>       if (port_id_is_invalid(port_id, ENABLED_WARN))
>>> @@ -1232,8 +1234,22 @@ port_mtu_set(portid_t port_id, uint16_t mtu)
>>>           return;
>>>       }
>>>       diag = rte_eth_dev_set_mtu(port_id, mtu);
>>> -    if (diag == 0)
>>> +    if (diag == 0) {
>>> +        /*
>>> +         * Ether overhead in driver is equal to the difference of
>>> +         * max_rx_pktlen and max_mtu in rte_eth_dev_info.
>>> +         */
>>> +        eth_overhead = dev_info.max_rx_pktlen - dev_info.max_mtu;
>>> +        if (mtu > RTE_ETHER_MAX_LEN - eth_overhead)
>>> +            rte_port->dev_conf.rxmode.offloads |=
>>> +                        DEV_RX_OFFLOAD_JUMBO_FRAME;
>>> +        else
>>> +            rte_port->dev_conf.rxmode.offloads &=
>>> +                        ~DEV_RX_OFFLOAD_JUMBO_FRAME;
>>
>> If the jumbo frame capability supported or not should be tested before 
>> setting it.
>>
>>> +        rte_port->dev_conf.rxmode.max_rx_pkt_len = mtu + eth_overhead;
>>
>> May need to check against 'dev_info.max_rx_pktlen', if the 
>> 'max_rx_pkt_len' is
>> bigger than this, it will fail in next configure.
>>
>> Also some divers already does this in PMD code, should we clean that 
>> code or not
>> is a question.
>>
> The snippset is adjusted as follows:
> 
> if (mtu > RTE_ETHER_MAX_LEN - eth_overhead && dev_info.rx_offload_capa & 
> DEV_RX_OFFLOAD_JUMBO_FRAME) {
>      rte_port->dev_conf.rxmode.offloads |=
>                                           DEV_RX_OFFLOAD_JUMBO_FRAME;
>      rte_port->dev_conf.rxmode.max_rx_pkt_len = mtu + eth_overhead;
> } else
>      rte_port->dev_conf.rxmode.offloads &=
>                      ~DEV_RX_OFFLOAD_JUMBO_FRAME;
> 
> We only modifies the internal variables of testpmd, don't impact on the 
> implementation of the driver.
> 
> Thanks for more suggestions.
> 
> XavierThe code is modified as follows:

diag = rte_eth_dev_set_mtu(port_id, mtu);
if (diag == 0 &&
     dev_info.rx_offload_capa & DEV_RX_OFFLOAD_JUMBO_FRAME) {
          /*
           * Ether overhead in driver is equal to the difference of
           * max_rx_pktlen and max_mtu in rte_eth_dev_info when the
           * device supports jumbo frame.
           */
          eth_overhead = dev_info.max_rx_pktlen - dev_info.max_mtu;
          if (mtu > RTE_ETHER_MAX_LEN - eth_overhead) {
                 rte_port->dev_conf.rxmode.offloads |= 

                         DEV_RX_OFFLOAD_JUMBO_FRAME;
                 rte_port->dev_conf.rxmode.max_rx_pkt_len =
                         mtu + eth_overhead;
          } else
                 rte_port->dev_conf.rxmode.offloads &= 

                        ~DEV_RX_OFFLOAD_JUMBO_FRAME;

         return;
}

We will send V2. Thanks

Xavier