On Sat, Mar 6, 2021 at 5:47 AM Andrew Lunn <and...@lunn.ch> wrote: > > On Fri, Mar 05, 2021 at 03:07:02PM -0800, Jakub Kicinski wrote: > > On Fri, 5 Mar 2021 16:15:51 +0530 Sunil Kovvuri wrote: > > > Hi, > > > > > > We have a requirement where in we want RSS hashing to be done on packet > > > fields > > > which are not currently supported by the ethtool. > > > > > > Current options: > > > ehtool -n <dev> rx-flow-hash > > > tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6 m|v|t|s|d|f|n|r > > > > > > Specifically our requirement is to calculate hash with DSA tag (which > > > is inserted by switch) plus the TCP/UDP 4-tuple as input. > > > > Can you share the format of the DSA tag? Is there a driver for it > > upstream? Do we need to represent it in union ethtool_flow_union? > > Sorry, i missed the original question, there was no hint in the > subject line that DSA was involved. > > Why do you want to include DSA tag in the hash? What normally happens > with DSA tag drivers is we detect the frame has been received from a > switch, and modify where the core flow dissect code looks in the frame > to skip over the DSA header and parse the IP header etc as normal.
I understand your point. The requirement to add DSA tag into RSS hashing is coming from one of our customer. > > Take a look at net/core/flow_dissect.c:__skb_flow_dissect() > > This fits with the core ideas of the network stack and offloads. Hide > the fact an offload is being used, it should just look like a normal > interface. > > Andrew Yes, the pkt will look like a normal packet itself. In our case HW strips the DSA tag from the packet and forwards it to a VF. Thanks, Sunil.
