[PATCH v5] app/testpmd: txonly multiflow port change support

[Ferruh Yigit]

On 4/22/2023 12:20 AM, Joshua Washington wrote:
> Google cloud routes traffic using IP addresses without the support of MAC
> addresses, so changing source IP address for txonly-multi-flow can have
> negative performance implications for net/gve when using testpmd. This
> patch updates txonly multiflow mode to modify source ports instead of
> source IP addresses.
> 
> The change can be tested with the following command:
> dpdk-testpmd -- --forward-mode=txonly --txonly-multi-flow \
>     --tx-ip=<SRC>,<DST>
> 
> Signed-off-by: Joshua Washington <joshwash at google.com>
> Reviewed-by: Rushil Gupta <rushilg at google.com>

Hi Joshua, Aman,

The reason to support multi-flow in Tx-only mode is, to test RSS in the
Rx side.
When used in guest, in a hypervisor infrastructure what is the usecase
for multi-flow, why not use default single IP?

And if there is a need to support multi-flow without updating source IP,
what about to support various modes as "--txonly-multi-flow=XXX", where
XXX can be src_ip, dst_ip, src_port, dst_port?
If possible by keeping no param '--txonly-multi-flow' same as current
usage (src_ip) for backward capability..

This extends testing capability and lets different platforms select
different config based on their needs.