[PATCH v2] app/testpmd: use Tx preparation in txonly engine

[Stephen Hemminger]

On Thu, 11 Jan 2024 13:25:55 +0800
Kaiwen Deng <kaiwenx.deng at intel.com> wrote:

> Txonly forwarding engine does not call the Tx preparation API
> before transmitting packets. This may cause some problems.
> 
> TSO breaks when MSS spans more than 8 data fragments. Those
> packets will be dropped by Tx preparation API, but it will cause
> MDD event if txonly forwarding engine does not call the Tx preparation
> API before transmitting packets.
> 
> We can reproduce this issue by these steps list blow on ICE and I40e.
> 
> ./x86_64-native-linuxapp-gcc/app/dpdk-testpmd -c 0xf -n 4 -- -i
> --tx-offloads=0x00008000
> 
> testpmd>set txpkts 64,128,256,512,64,128,256,512,512
> testpmd>set burst 1
> testpmd>start tx_first 1  
> 
> This commit will use Tx preparation API in txonly forwarding engine.
> 
> Fixes: 655131ccf727 ("app/testpmd: factorize fwd engines Tx")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Kaiwen Deng <kaiwenx.deng at intel.com>

Acked-by: Stephen Hemminger <stephen at networkplumber.org>