Re: [dpdk-dev] [PATCH] net/ixgbe: initialize max_rx_pkt_len if rlpml_set_vf fails

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 10/15/2021 3:20 PM, Tudor Cornea wrote:
> Some of our customers use ESXi 6.0 or 6.5 servers, which could have older
> versions of the PF ixgbe driver.
> It seems that with a more recent version of the PMD driver, we are not able
> to initialize 82599EB ports correctly.
> This scenario seems to have worked with DPDK 19.11.
> 
> Would it be possible to print a warning, while still allowing the driver to
> initialize the ports ?
> 
> I was also thinking about the return code of ixgbevf_dev_set_mtu.
> Do you think it would be more appropriate to return ENOTSUP or ENOSYS
> instead of EINVAL ?
> 
> As a user, calling 'rte_eth_dev_mtu_set', I would expect an error like
> EINVAL to suggest to me that
> the mtu value which I provided is incorrect [1]. The 82599 NIC, however has
> some particularities related to mtu,
> which could cause the operation to fail. I was thinking that EINVAL might
> not be most descriptive error.
> 
> [1] https://doc.dpdk.org/api/rte__ethdev_8h.html
> 
> Thanks,
> Tudor

Hi Tudor,

Can you please check if the patch is still after 'max_rx_pkt_len' related changes
in next-net?

> 
> On Fri, 15 Oct 2021 at 17:06, Tudor Cornea <tudor.cornea@gmail.com> wrote:
> 
>> It seems that if the call to ixgbevf_rlpml_set_vf fails,
>> we will not initialize dev_conf.rxmode.max_rx_pkt_len correctly anymore.
>>
>> This happens with a 82599EB NIC and a VMware ESXI 6.0 setup,
>> and is causing VF the ports to fail to initialize
>>
>> We see the following error:
>> ixgbevf_dev_rx_init(): Set max packet length to 1518 failed.
>>
>> Investigating over DPDK 19.11, it seems that the call still fails,
>> but it doesn't exit prematurely, and max_rx_pkt_len is initialized in
>> the respective case.
>>
>> On the ESXi server, we seem to have the following driver
>> net-ixgbe: 3.7.13.7.14iov-20vmw.600.0.0.2494585
>>
>> It seems that the behavior related to MTU setting has changed
>> since the following commit:
>>
>> commit c77866a16904 ("net/ixgbe: detect failed VF MTU set")
>>
>> We would like to still be able to support older setups if possible,
>> as we might have customers running ESXi 6.0 or 6.5, and these seem
>> to have an older version of the PF driver as default.
>>
>> Signed-off-by: Tudor Cornea <tudor.cornea@gmail.com>
>> ---
>>   drivers/net/ixgbe/ixgbe_ethdev.c | 5 +++--
>>   drivers/net/ixgbe/ixgbe_rxtx.c   | 1 -
>>   2 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
>> b/drivers/net/ixgbe/ixgbe_ethdev.c
>> index 4dbe049..4301dfd 100644
>> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
>> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
>> @@ -6369,6 +6369,9 @@ ixgbevf_dev_set_mtu(struct rte_eth_dev *dev,
>> uint16_t mtu)
>>                  return -EINVAL;
>>          }
>>
>> +       /* update max frame size */
>> +       dev->data->dev_conf.rxmode.max_rx_pkt_len = max_frame;
>> +
>>          /*
>>           * When supported by the underlying PF driver, use the
>> IXGBE_VF_SET_MTU
>>           * request of the version 2.0 of the mailbox API.
>> @@ -6381,8 +6384,6 @@ ixgbevf_dev_set_mtu(struct rte_eth_dev *dev,
>> uint16_t mtu)
>>          if (ixgbevf_rlpml_set_vf(hw, max_frame))
>>                  return -EINVAL;
>>
>> -       /* update max frame size */
>> -       dev->data->dev_conf.rxmode.max_rx_pkt_len = max_frame;
>>          return 0;
>>   }
>>
>> diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c
>> b/drivers/net/ixgbe/ixgbe_rxtx.c
>> index 0ac89cb..02d9809 100644
>> --- a/drivers/net/ixgbe/ixgbe_rxtx.c
>> +++ b/drivers/net/ixgbe/ixgbe_rxtx.c
>> @@ -5677,7 +5677,6 @@ ixgbevf_dev_rx_init(struct rte_eth_dev *dev)
>>              (uint16_t)dev->data->dev_conf.rxmode.max_rx_pkt_len)) {
>>                  PMD_INIT_LOG(ERR, "Set max packet length to %d failed.",
>>                               dev->data->dev_conf.rxmode.max_rx_pkt_len);
>> -               return -EINVAL;
>>          }
>>
>>          /*
>> --
>> 2.7.4
>>
>>