[PATCH v3 1/2] examples/l3fwd: relax RSS requirement with option

[Stephen Hemminger]

On Sun, 12 Nov 2023 07:16:10 +0000
Trevor Tao <taozj888 at 163.com> wrote:

> Now the port Rx mq_mode had been set to RTE_ETH_MQ_RX_RSS
> by default, but some hw and/or virtual interface does not
> support the RSS and offload mode presupposed, e.g., some
> virtio interfaces in the cloud don't support
> RSS and the error msg may like:
> 
> virtio_dev_configure(): RSS support requested but not supported by
> the device
> Port0 dev_configure = -95
> 
> So to enable the l3fwd running in that environment, the Rx mode requirement
> can be relaxed to reflect the hardware feature reality here, and the l3fwd
> can run smoothly then.
> 
> An option named "relax-rx-mode" is added to enable the relax action
> here, and it's disabled by default.
> 
> Signed-off-by: Trevor Tao <taozj888 at 163.com>

Doesn't need to be an option. The application can just look at the offload
flags and quickly determine that if multiple queues are being used than
RSS is required. If device doesn't support RSS, then fallback to single
queue with a warning.