Normally, to use the HW offloads capability (e.g. checksum and TSO) in
the Tx direction, the application needs to call rte_eth_tx_prepare() to
do some adjustment with the packets before sending them. But the
tx_prepare callback of the bonding driver is not implemented. Therefore,
the sent packets may have errors (e.g. checksum errors).
However, it is difficult to design the tx_prepare callback for bonding
driver. Because when a bonded device sends packets, the bonded device
allocates the packets to different slave devices based on the real-time
link status and bonding mode. That is, it is very difficult for the
bonded device to determine which slave device's prepare function should
be invoked.
So in this patch, the tx_prepare callback of bonding driver is not
implemented. Instead, the rte_eth_tx_prepare() will be called before
rte_eth_tx_burst(). In this way, all tx_offloads can be processed
correctly for all NIC devices.
Note: because it is rara that bond different PMDs together, so just
call tx-prepare once in broadcast bonding mode.
Also the following description was added to the rte_eth_tx_burst()
function:
"@note This function must not modify mbufs (including packets data)
unless the refcnt is 1. The exception is the bonding PMD, which does not
have tx-prepare function, in this case, mbufs maybe modified."
Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Reviewed-by: Min Hu (Connor) <humin29@huawei.com>
Acked-by: Chas Williams <3chas3@gmail.com>
c622735dd3