On 11/24/20 11:00 PM, Parav Pandit wrote: > Hi David, > >> From: David Ahern <dsahern@xxxxxxxxx> >> Sent: Wednesday, November 25, 2020 11:04 AM >> >> On 11/18/20 10:57 PM, Saeed Mahameed wrote: >>> >>> We are not slicing up any queues, from our HW and FW perspective SF == >>> VF literally, a full blown HW slice (Function), with isolated control >>> and data plane of its own, this is very different from VMDq and more >>> generic and secure. an SF device is exactly like a VF, doesn't steal >>> or share any HW resources or control/data path with others. SF is >>> basically SRIOV done right. >> >> What does that mean with respect to mac filtering and ntuple rules? >> >> Also, Tx is fairly easy to imagine, but how does hardware know how to direct >> packets for the Rx path? As an example, consider 2 VMs or containers with the >> same destination ip both using subfunction devices. > Since both VM/containers are having same IP, it is better to place them in different L2 domains via vlan, vxlan etc. ok, so relying on <vlan, dmac> pairs. > >> How does the nic know how to direct the ingress flows to the right queues for >> the subfunction? >> > Rx steering occurs through tc filters via representor netdev of SF. > Exactly same way as VF representor netdev operation. > > When devlink eswitch port is created as shown in example in cover letter, and also in patch-12, it creates the representor netdevice. > Below is the snippet of it. > > Add a devlink port of subfunction flavour: > $ devlink port add pci/0000:06:00.0 flavour pcisf pfnum 0 sfnum 88 > > Configure mac address of the port function: > $ devlink port function set ens2f0npf0sf88 hw_addr 00:00:00:00:88:88 > ^^^^^^^^^^^^^^ > This is the representor netdevice. It is created by port add command. > This name is setup by systemd/udev v245 and higher by utilizing the existing phys_port_name infrastructure already exists for PF and VF representors. hardware ensures only packets with that dmac are sent to the subfunction device. > > Now user can add unicast rx tc rule for example, > > $ tc filter add dev ens2f0np0 parent ffff: prio 1 flower dst_mac 00:00:00:00:88:88 action mirred egress redirect dev ens2f0npf0sf88 > > I didn't cover this tc example in cover letter, to keep it short. > But I had a one line description as below in the 'detail' section of cover-letter. > Hope it helps. > > - A SF supports eswitch representation and tc offload support similar > to existing PF and VF representors. > > Now above portion answers, how to forward the packet to subfunction. > But how to forward to the right rx queue out of multiple rxqueues? > This is done by the rss configuration done by the user, number of channels from ethtool. > Just like VF and PF. > The driver defaults are similar to VF, which user can change via ethtool. > so users can add flow steering or drop rules to SF devices. thanks,
