[net-next,0/8] Introduce conntrack offloading to the nfp driver

Message

Simon Horman May 28, 2021, 2:42 p.m. UTC

Louis Peens says:

This is the first in a series of patches to offload conntrack
to the nfp. The approach followed is to flatten out three
different flow rules into a single offloaded flow. The three
different flows are:

1. The rule sending the packet to conntrack (pre_ct)
2. The rule matching on +trk+est after a packet has been through
   conntrack. (post_ct)
3. The rule received via callback from the netfilter (nft)

In order to offload a flow we need a combination of all three flows, but
they could be added/deleted at different times and in different order.

To solve this we save potential offloadable CT flows in the driver,
and every time we receive a callback we check against these saved flows
for valid merges. Once we have a valid combination of all three flows
this will be offloaded to the NFP. This is demonstrated in the diagram
below.

+-------------+                      +----------+
| pre_ct flow +--------+             | nft flow |
+-------------+        v             +------+---+
                  +----------+              |
                  | tc_merge +--------+     |
                  +----------+        v     v
+--------------+       ^           +-------------+
| post_ct flow +-------+       +---+nft_tc merge |
+--------------+               |   +-------------+
                               |
                               |
                               |
                               v
                        Offload to nfp

This series is only up to the point of the pre_ct and post_ct
merges into the tc_merge. Follow up series will continue
to add the nft flows and merging of these flows with the result
of the pre_ct and post_ct merged flows.

Louis Peens (8):
  nfp: flower: move non-zero chain check
  nfp: flower-ct: add pre and post ct checks
  nfp: flower-ct: add ct zone table
  nfp: flower-ct: add zone table entry when handling pre/post_ct flows
  nfp: flower-ct: add nfp_fl_ct_flow_entries
  nfp: flower-ct: add a table to map flow cookies to ct flows
  nfp: flower-ct: add tc_merge_tb
  nfp: flower-ct: add tc merge functionality

 drivers/net/ethernet/netronome/nfp/Makefile   |   3 +-
 .../ethernet/netronome/nfp/flower/conntrack.c | 486 ++++++++++++++++++
 .../ethernet/netronome/nfp/flower/conntrack.h | 154 ++++++
 .../net/ethernet/netronome/nfp/flower/main.h  |   6 +
 .../ethernet/netronome/nfp/flower/metadata.c  | 101 +++-
 .../ethernet/netronome/nfp/flower/offload.c   |  31 +-
 6 files changed, 774 insertions(+), 7 deletions(-)
 create mode 100644 drivers/net/ethernet/netronome/nfp/flower/conntrack.c
 create mode 100644 drivers/net/ethernet/netronome/nfp/flower/conntrack.h