Re: jumbo frame support for 82583V

[Klaus Degner <kd@allegro-packets.com>]

Hi Wenzhuo,
> Hi Klaus,
>
>> -----Original Message-----
>> From: Klaus Degner [mailto:kd@allegro-packets.com]
>> Sent: Friday, July 17, 2015 7:56 PM
>> To: Lu, Wenzhuo
>> Cc: dev@dpdk.org
>> Subject: jumbo frame support for 82583V
>>
>> Hi Wenzhuo,
>>
>> We are testing different Intel NICs for DPDK. We have tested the master branch
>> with the support for 82583V Intel chip.
>> It works very well except that we can only use up to 1518 bytes for maximum
>> packet capture.
>> We have debugged this and it is restricted in the initialization:
>>
>> http://dpdk.org/browse/dpdk/tree/drivers/net/e1000/em_ethdev.c#n855
>>
>> Without DPDK, the linux driver support and mtu up to 9k and ark.intel reports
>> that this chip is jumbo frame capable:
>>
>> http://ark.intel.com/de/products/41676/Intel-82583V-Gigabit-Ethernet-
>> Controller
>>
>> Is there any specific reason why DPDK cannot use jumbo frames for this NIC ?
>>
>> Thanks for help !
>>
>> Klaus
> Sorry, I'm not sure about the history.
> According to the datasheet's update log, 82583v doesn't support jumbo frame at first.
> I think the reason is the e1000 code is not updated after the datasheet said the jumbo frame is supported.
> As I don’t have the NIC on hand, would you like to change the code and have a try. I mean just let
> " case e1000_82583" return 9K. Thanks.

The DPDK jumbo frame send and receive works for 82583V.
We have tested it with 4x 85283V and the setup:

Linux send --> DPDK receive --> DPDK send --> Linux receive

We could send a 9k packet via this data path and have verified the
content of it.
I can generate a patch for DPDK if this is enough testing for you.

Thanks,

Klaus