Context 0 (default context) always exists, there is no need to check whether it exists or not when adding a flow steering rule.

The existing check fails when creating a flow steering rule for context 0 as it is not stored in the rss_ctx xarray.

For example: $ ethtool --config-ntuple eth2 flow-type tcp4 dst-ip 194.237.147.23 dst-port 19983 context 0 loc 618 rmgr: Cannot insert RX class rule: Invalid argument Cannot insert classification rule

An example usecase for this could be: - A high-priority rule (loc 0) directing specific port traffic to context 0. - A low-priority rule (loc 1) directing all other TCP traffic to context 1.

This is a user-visible regression that was caught in our testing environment, it was not reported by a user yet.

Fixes: de7f7582dff2 ("net: ethtool: prevent flow steering to RSS contexts which don't exist") Cc: Jakub Kicinski kuba@kernel.org Reviewed-by: Tariq Toukan tariqt@nvidia.com Reviewed-by: Nimrod Oren noren@nvidia.com Signed-off-by: Gal Pressman gal@nvidia.com Reviewed-by: Joe Damato jdamato@fastly.com --- net/ethtool/ioctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index 39ec920f5de7..71c828d0bf31 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -1083,7 +1083,8 @@ static noinline_for_stack int ethtool_set_rxnfc(struct net_device *dev, ethtool_get_flow_spec_ring(info.fs.ring_cookie)) return -EINVAL;

- if (!xa_load(&dev->ethtool->rss_ctx, info.rss_context)) + if (info.rss_context && + !xa_load(&dev->ethtool->rss_ctx, info.rss_context)) return -EINVAL; }

Add test_rss_default_context_rule() to verify that ntuple rules can correctly direct traffic to the default RSS context (context 0).

The test creates two ntuple rules with explicit location priorities: - A high-priority rule (loc 0) directing specific port traffic to context 0. - A low-priority rule (loc 1) directing all other TCP traffic to context 1.

This validates that: 1. Rules targeting the default context function properly. 2. Traffic steering works as expected when mixing default and additional RSS contexts.

The test was written by AI, and reviewed by humans.

Cc: Jakub Kicinski kuba@kernel.org Reviewed-by: Nimrod Oren noren@nvidia.com Signed-off-by: Gal Pressman gal@nvidia.com --- .../selftests/drivers/net/hw/rss_ctx.py | 59 ++++++++++++++++++- 1 file changed, 58 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/drivers/net/hw/rss_ctx.py b/tools/testing/selftests/drivers/net/hw/rss_ctx.py index ca60ae325c22..7bb552f8b182 100755 --- a/tools/testing/selftests/drivers/net/hw/rss_ctx.py +++ b/tools/testing/selftests/drivers/net/hw/rss_ctx.py @@ -747,6 +747,62 @@ def test_rss_ntuple_addition(cfg): 'noise' : (0,) })

+def test_rss_default_context_rule(cfg): + """ + Allocate a port, direct this port to context 0, then create a new RSS + context and steer all TCP traffic to it (context 1). Verify that: + * Traffic to the specific port continues to use queues of the main + context (0/1). + * Traffic to any other TCP port is redirected to the new context + (queues 2/3). + """ + + require_ntuple(cfg) + + queue_cnt = len(_get_rx_cnts(cfg)) + if queue_cnt < 4: + try: + ksft_pr(f"Increasing queue count {queue_cnt} -> 4") + ethtool(f"-L {cfg.ifname} combined 4") + defer(ethtool, f"-L {cfg.ifname} combined {queue_cnt}") + except Exception as exc: + raise KsftSkipEx("Not enough queues for the test") from exc + + # Use queues 0 and 1 for the main context + ethtool(f"-X {cfg.ifname} equal 2") + defer(ethtool, f"-X {cfg.ifname} default") + + # Create a new RSS context that uses queues 2 and 3 + ctx_id = ethtool_create(cfg, "-X", "context new start 2 equal 2") + defer(ethtool, f"-X {cfg.ifname} context {ctx_id} delete") + + # Generic low-priority rule: redirect all TCP traffic to the new context. + # Give it an explicit higher location number (lower priority). + flow_generic = f"flow-type tcp{cfg.addr_ipver} dst-ip {cfg.addr} context {ctx_id} loc 1" + ethtool(f"-N {cfg.ifname} {flow_generic}") + defer(ethtool, f"-N {cfg.ifname} delete 1") + + # Specific high-priority rule for a random port that should stay on context 0. + # Assign loc 0 so it is evaluated before the generic rule. + port_main = rand_port() + flow_main = f"flow-type tcp{cfg.addr_ipver} dst-ip {cfg.addr} dst-port {port_main} context 0 loc 0" + ethtool(f"-N {cfg.ifname} {flow_main}") + defer(ethtool, f"-N {cfg.ifname} delete 0") + + _ntuple_rule_check(cfg, 1, ctx_id) + + # Verify that traffic matching the specific rule still goes to queues 0/1 + _send_traffic_check(cfg, port_main, "context 0", + { 'target': (0, 1), + 'empty' : (2, 3) }) + + # And that traffic for any other port is steered to the new context + port_other = rand_port() + _send_traffic_check(cfg, port_other, f"context {ctx_id}", + { 'target': (2, 3), + 'noise' : (0, 1) }) + + def main() -> None: with NetDrvEpEnv(__file__, nsim_test=False) as cfg: cfg.context_cnt = None @@ -760,7 +816,8 @@ def main() -> None: test_rss_context_overlap, test_rss_context_overlap2, test_rss_context_out_of_order, test_rss_context4_create_with_cfg, test_flow_add_context_missing, - test_delete_rss_context_busy, test_rss_ntuple_addition], + test_delete_rss_context_busy, test_rss_ntuple_addition, + test_rss_default_context_rule], args=(cfg, )) ksft_exit()