Flow Bifurcation of splitting the traffic between kernel space and user space (DPDK)

[Stephen Hemminger]

On Sat, 29 Oct 2022 02:39:01 +0530
Ramakrishnan G <gramakr at gmail.com> wrote:

> From: Ramakrishnan G <gramakr at gmail.com>
> To: aaron.f.brown at intel.com, dev at dpdk.org, saravana3 at gmail.com
> Subject: Flow Bifurcation of splitting the traffic between kernel space and  user space (DPDK)
> Date: Sat, 29 Oct 2022 02:39:01 +0530
> 
> Dear Aaron and DPDK Dev Team,
> 
> Thanks for the Article talks about the Traffic Flow bifurcation
> between kernel space and user space (DPDK) (3. Flow Bifurcation How-to
> Guide — Data Plane Development Kit 16.07.2 documentation (dpdk.org)
> <https://doc.dpdk.org/guides-16.07/howto/flow_bifurcation.html>)

That DPDK release is over 6 years old. That feature is no longer supported on Intel
NIC's. You are better off using AF_XDP. 

> 
> We are trying to test this functionality for sending only the SSH (port 22)
> traffic to kernel and all the other traffic to be transferred to the user
> space (DPDK) by assigning same IP for both the virtual interface (one
> virtual interface is owned by the DPDK and another virtual interface is
> owned by the DPDK )
> 
> Using the igb driver with max_vfs setting, we were able to create the
> virtual link and map it to user space (DPDK) and another link into kernel
> space. we assigned different IP addresses and we were able to reach from
> other host.
> 
> But when we are trying to configure the flow-type for port 22
> 
> Ubuntu# ethtool -K eth9 ntuple on
> Ubuntu## ethtool -N eth9 flow-type ip4 dst-port 22 action 0
> rmgr: Cannot insert RX class rule: Invalid argument
> Ubuntu## ethtool -N eth9 flow-type ip4 dst-port 22 action 1
> rmgr: Cannot insert RX class rule: Invalid argument
> Ubuntu## ethtool -N eth9 flow-type ip4 dst-port 22 action 2
> rmgr: Cannot insert RX class rule: Invalid argument
> 
> We tried to apply the patch that was given in the following link,
> (
> https://patchwork.ozlabs.org/project/intel-wired-lan/patch/1451456399-13353-1-git-send-email-gangfeng.huang@ni.com/#1236040
> )
> 
> But we couldn't patch any of the latest igb driver and we tried to patch
> with the 2016 igb driver.
> 
> please help us in sharing the info where can we apply the patch for igb
> driver in Ubuntu.

The igb NIC does not have an flow direction.
The bifurcation for Intel NIC is based off of kernel flow director.