[dpdk-dev] [PATCH v12 0/6] add Tx preparation

Ferruh Yigit ferruh.yigit at intel.com
Tue Dec 13 12:59:46 CET 2016


On 12/6/2016 3:53 PM, Ferruh Yigit wrote:
> On 11/28/2016 11:03 AM, Thomas Monjalon wrote:
>> We need attention of every PMD developers on this thread.
>>
>> Reminder of what Konstantin suggested:
>> "
>> - if the PMD supports TX offloads AND
>> - if to be able use any of these offloads the upper layer SW would have to:
>>     * modify the contents of the packet OR
>>     * obey HW specific restrictions
>> then it is a PMD developer responsibility to provide tx_prep() that would implement
>> expected modifications of the packet contents and restriction checks.
>> Otherwise, tx_prep() implementation is not required and can be safely set to NULL.      
>> "
>>
>> I copy/paste also my previous conclusion:
>>
>> Before txprep, there is only one API: the application must prepare the
>> packets checksum itself (get_psd_sum in testpmd).
>> With txprep, the application have 2 choices: keep doing the job itself
>> or call txprep which calls a PMD-specific function.
>> The question is: does non-Intel drivers need a checksum preparation for TSO?
>> Will it behave well if txprep does nothing in these drivers?
>>
>> When looking at the code, most of drivers handle the TSO flags.
>> But it is hard to know whether they rely on the pseudo checksum or not.
>>
>> git grep -l 'PKT_TX_UDP_CKSUM\|PKT_TX_TCP_CKSUM\|PKT_TX_TCP_SEG' drivers/net/
>>
>> drivers/net/bnxt/bnxt_txr.c
>> drivers/net/cxgbe/sge.c
>> drivers/net/e1000/em_rxtx.c
>> drivers/net/e1000/igb_rxtx.c
>> drivers/net/ena/ena_ethdev.c
>> drivers/net/enic/enic_rxtx.c
>> drivers/net/fm10k/fm10k_rxtx.c
>> drivers/net/i40e/i40e_rxtx.c
>> drivers/net/ixgbe/ixgbe_rxtx.c
>> drivers/net/mlx4/mlx4.c
>> drivers/net/mlx5/mlx5_rxtx.c
>> drivers/net/nfp/nfp_net.c
>> drivers/net/qede/qede_rxtx.c
>> drivers/net/thunderx/nicvf_rxtx.c
>> drivers/net/virtio/virtio_rxtx.c
>> drivers/net/vmxnet3/vmxnet3_rxtx.c
>>
>> Please, we need a comment for each driver saying
>> "it is OK, we do not need any checksum preparation for TSO"
>> or
>> "yes we have to implement tx_prepare or TSO will not work in this mode"
>>
> 
> Still waiting response from PMDs:
> - ena
> - nfp
> - virtio
> 
> Waiting clarification for preparation requirements:
> - vmxnet3
> 
> Also including new PMDs to the thread:
> - sfc
> - dpaa2

Thanks all for responses, now only remaining ones are following:

Waiting clarification for preparation requirements: (it would be great
if details can be provided before next version of the patch)
- ena

Will support review/testing of the patch:
- vmxnet3

new PMD (still not in repo, so response is good to have)
- dpaa2




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