From: Jakub Kicinski <kuba@kernel.org>
Date: Thu, 4 Jun 2026 00:42:33 +0000 (-0700)
Subject: Merge branch 'net-mlx5-add-switchdev-mode-support-for-socket-direct-single-netdev... 
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=c0192c7ec1fc5fa4ec9793bb460204715e2d9cd3;p=thirdparty%2Fkernel%2Flinux.git

Merge branch 'net-mlx5-add-switchdev-mode-support-for-socket-direct-single-netdev-part-1-2'

Tariq Toukan says:

====================
net/mlx5: Add switchdev mode support for Socket Direct single netdev, part 1/2

This series enables Socket Direct single netdev to operate in switchdev
mode with shared FDB. SD single netdev combines multiple PCI functions
behind a single netdev interface. To support switchdev offloads, these
functions must participate in virtual LAG (shared FDB).

Design

Rather than introducing a separate LAG instance for SD, this series
integrates SD secondary devices into the existing LAG structure
(priv.lag) created at probe time. Each lag_func entry carries a
group_id field that identifies its SD group membership (0 means not
part of any SD group). An xarray mark (XA_MARK_PORT) distinguishes
physical port entries from SD secondaries, enabling a single unified
iterator that filters by group:

  - MLX5_LAG_FILTER_PORTS: iterate port-level entries only (existing
    behavior, used by bonding, FW LAG commands, v2p_map)
  - MLX5_LAG_FILTER_ALL: iterate all devices including SD secondaries
    (used by MPESW shared FDB across all devices)
  - specific group_id: iterate only devices in that SD group (used by
    per-group SD shared FDB operations)

Existing callers use mlx5_ldev_for_each() which maps to
MLX5_LAG_FILTER_PORTS, preserving current behavior for non-SD
configurations.

Lifecycle and ownership

The SD LAG lifecycle is tied to the SD group, not to bonding events:

1. At PCI probe, mlx5_lag_add_mdev() creates the LAG structure
   (priv.lag) for each LAG-capable PF. e.g.: SD primary devices

2. During mlx5_sd_init(), after the SD group is fully formed (primary
   and secondaries paired), sd_lag_init() registers the secondary
   devices into the primary's existing priv.lag by calling
   mlx5_ldev_add_mdev() with the SD group_id. The primary's lag_func
   also gets its group_id set. No separate LAG instance is created.

3. After all the devices in SD group transition to switchdev,
   mlx5_lag_shared_fdb_create() is invoked with the group_id to create
   a software-only shared FDB scoped to that SD group. This sets
   sd_fdb_active on all lag_func entries in the group. No FW LAG
   commands are issued since SD devices share the same physical port.

4. If MPESW (multi-port eswitch) is enabled on top of SD groups, the
   per-group SD shared FDB is torn down first, then MPESW shared FDB is
   created spanning all devices (ports + SD secondaries) using
   MLX5_LAG_FILTER_ALL. On MPESW disable, per-group SD shared FDB is
   restored.

5. On SD teardown (mlx5_sd_cleanup or device unbind), sd_lag_cleanup()
   removes secondaries from priv.lag and clears the primary's group_id.
   The LAG structure itself is not destroyed.

The sd_fdb_active flag is set on all lag_func entries in a group (not
just the primary), so any device can detect the SD shared FDB state
during lag_disable_change teardown without needing to look up peer
entries.

SD shared FDB is a pure software construct -- unlike regular LAG modes
(ROCE, SRIOV, MPESW), it does not issue FW create_lag/destroy_lag
commands. The software vport LAG for SD is implemented via eswitch
egress ACL bounce rules, managed by the IB layer through
mlx5_eth_lag_init(). And the software LAG demux is implemented via
steering rules that utilize new destination, VHCA_RX.

Patches

Infrastructure (patches 1, 5-6):
  - Factor out shared FDB code into a dedicated file
  - Extend lag_func with group_id and sd_fdb_active fields;
    add XA_MARK_PORT and unified iterator with group_id filter
  - Extend shared FDB API with group_id parameter

E-Switch preparation (patches 2-3):
  - Align eswitch disable sequence ordering
  - Move devcom init from TC to eswitch layer

SD group management (patches 4, 7-9):
  - Replace peer count check with direct peer lookup
  - Register SD secondaries in the existing LAG at SD init time
  - Block RoCE and VF LAG for SD devices
  - Block multipath LAG for SD devices

Switchdev integration (patch 10):
  - Keep netdev resources local in switchdev mode

Steering (patches 11-12):
  - Track peer flow slots with bitmap for selective peer flow deletion
  - Enable TC flow steering for SD LAG

Enablement (patch 13):
  - Verify unique vhca_id count for cross-VHCA RQT
====================

Link: https://patch.msgid.link/20260531113954.395443-1-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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