[dpdk-dev] [RFC 0/2] add Tx prepare support for bonding device

[Ferruh Yigit]

On 4/16/2021 12:04 PM, Chengchang Tang wrote:
> This patch add Tx prepare for bonding device.
> 
> Currently, the bonding driver has not implemented the callback of
> rte_eth_tx_prepare function. Therefore, the TX prepare function of the
> slave devices will never be invoked. When hardware offloading such as
> CKSUM and TSO are enabled for some drivers, tx_prepare needs to be used
> to adjust packets (for example, set correct pseudo packet headers).
> Otherwise, related offloading fails and even packets are sent
> incorrectly. Due to this limitation, the bonded device cannot use these
> HW offloading in the Tx direction.
> 
> Because packet sending algorithms are numerous and complex in bond PMD,
> it is hard to design the callback for rte_eth_tx_prepare. In this patch,
> the tx_prepare callback of bonding PMD is not implemented. Instead,
> rte_eth_tx_prepare has been called in tx_burst callback. And a global
> variable is introduced to control whether the bonded device need call
> the rte_eth_tx_prepare. If upper-layer users need to use some TX
> offloading that depend on tx_prepare , they should enable the preparation
> function. In this way, the bonded device will call the rte_eth_tx_prepare
> for the fast path packets in the tx_burst callback.
> 

What do you think to add a devarg to bonding PMD to control the tx_prepare?
It won't be as dynamic as API, since it can be possible to change the behavior 
after application is started with API, but do we really need this?

> Chengchang Tang (2):
>    net/bonding: add Tx prepare for bonding
>    app/testpmd: add cmd for bonding Tx prepare
> 
>   app/test-pmd/cmdline.c                      | 66 +++++++++++++++++++++++++++++
>   doc/guides/testpmd_app_ug/testpmd_funcs.rst |  9 ++++
>   drivers/net/bonding/eth_bond_private.h      |  1 +
>   drivers/net/bonding/rte_eth_bond.h          | 29 +++++++++++++
>   drivers/net/bonding/rte_eth_bond_api.c      | 28 ++++++++++++
>   drivers/net/bonding/rte_eth_bond_pmd.c      | 33 +++++++++++++--
>   drivers/net/bonding/version.map             |  5 +++
>   7 files changed, 167 insertions(+), 4 deletions(-)
> 
> --
> 2.7.4
>