[PATCH nf-next v3 0/3] netfilter: flowtable: carry a priority into the offload

[Julius Bairaktaris]

Packets forwarded by the flowtable skip the ruleset, so a priority set
with "meta priority set" before "flow add" is lost after the first
packets. Patch 2 stores skb->priority in the flow, applies it in the
software fast path and passes it to drivers as FLOW_ACTION_PRIORITY.
Patch 1 makes mlx5 ignore that action on flowtable flows, so flows it
offloads today stay offloaded. Patch 3 adds a selftest.

v2 review asked whether this should be a flowtable attribute instead.
A per-flow priority covers both one class per flowtable and a class
chosen per connection, with existing syntax:

  meta priority set 1:3 flow add @ft
  udp dport 5060 meta priority set 1:3 flow add @ft

An attribute needs one flowtable per class. nft rejects a device in
two flowtables of the same table with -EEXIST, so it also needs one
table per class. Pablo, is the per-flow approach fine with you?

mlx5 maintainers: patch 1 is needed before patch 2 and is meant to go
through nf-next; an Acked-by would allow that.

The selftest passes with the series, and its priority checks fail with
only patch 3 applied (QEMU, three runs). The mlx5, airoha and mtk
changes are compile-tested only; Lorenzo, a Tested-by on airoha would
be welcome. struct flow_offload grows by 8 bytes.

Changes in v3:
- new patch 1 for mlx5
- airoha uses the priority for its QoS queue (Lorenzo Bianconi)
- describe the tc flower effect and the TOS-derived priority
- rebased onto nf-next

v2: https://lore.kernel.org/netfilter-devel/20260902155136.4963-1-julius@xxxxxxxxxxxxxx/
v1: https://lore.kernel.org/netfilter-devel/20260901092632.369248-1-julius@xxxxxxxxxxxxxx/

Julius Bairaktaris (3):
  net/mlx5e: Ignore FLOW_ACTION_PRIORITY on flowtable offload
  netfilter: flowtable: carry a priority into the offload
  selftests: netfilter: nft_flowtable.sh: check the priority a flow
    carries

 Documentation/networking/nf_flowtable.rst     |   4 +-
 drivers/net/ethernet/airoha/airoha_ppe.c      |   3 +
 .../net/ethernet/mediatek/mtk_ppe_offload.c   |   1 +
 .../net/ethernet/mellanox/mlx5/core/Makefile  |   2 +-
 .../mellanox/mlx5/core/en/tc/act/act.c        |   1 +
 .../mellanox/mlx5/core/en/tc/act/act.h        |   1 +
 .../mellanox/mlx5/core/en/tc/act/prio.c       |  22 ++++
 include/net/netfilter/nf_flow_table.h         |   1 +
 net/netfilter/nf_flow_table_ip.c              |   6 +
 net/netfilter/nf_flow_table_offload.c         |  11 ++
 net/netfilter/nft_flow_offload.c              |   2 +
 .../selftests/net/netfilter/nft_flowtable.sh  | 110 ++++++++++++++++++
 12 files changed, 162 insertions(+), 2 deletions(-)
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/prio.c


base-commit: 87b80c2f6b05cad9f0ff9136709c62a0f59923e3
-- 
2.53.0