IPv4 flows per queue on top of RSS for ixgbe and i40e drivers

[Pavel Vazharov <freakpv@gmail.com>]

Hi there,

We have a proxy application on top of DPDK where we use a symmetric
RSS key to receive the packets for a given connection in both
directions on a single queue. In addition to that, we've few IPv4
addresses where we need to receive their traffic on particular queues.
We use the rte flows functionality with RTE_FLOW_ACTION_TYPE_QUEUE to
achieve that and it seemed to work with the DPDK ixgbe driver.
However, today we tried the same application on top of DPDK i40e
driver and this setup doesn't seem to work there. It prints the
following errors:
`i40e_flow_add_del_fdir_filter(): Conflict with existing flow director rules!`
It seems that the i40e driver doesn't allow adding flow rules on top
of the already set RSS.

Can somebody suggest a way to achieve what we need with i40e: to use a
symmetric RSS key for most of the traffic but to redirect the traffic
for a few specific IPv4 addresses to particular queues?

Thanks,
Pavel.