Re: [PATCH net v2 4/4] selftests: drv-net: rss_ctx: test RSS contexts persist after ifdown/up

[Bobby Eshleman <bobbyeshleman@gmail.com>]

On Thu, Feb 05, 2026 at 09:29:30PM -0800, Michael Chan wrote:
> From: Pavan Chebbi <pavan.chebbi@broadcom.com>
> 
> Add a test to verify that RSS contexts persist across interface
> down/up along with their associated Ntuple fitlers. Another test
> that creates contexts/rules keeping interface down and test their
> persistence is also added.
> 
> Tested on bnxt_en:
> 
>  TAP version 13
>  1..1
>  # timeout set to 0
>  # selftests: drivers/net/hw: rss_ctx.py
>  # TAP version 13
>  # 1..2
>  # ok 1 rss_ctx.test_rss_context_persist_create_and_ifdown
>  # ok 2 rss_ctx.test_rss_context_persist_ifdown_and_create # SKIP Create context not supported with interface down
>  # # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:1 error:0
> 
> Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
> Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
> Signed-off-by: Michael Chan <michael.chan@broadcom.com>
> ---
> v2: Many improvements suggested by Jakub:
> 1. simplified the tests to have only 2 contexts, use one of the contexts
> to test ntuple filters' persistence also 
> 2. used @ksft_disruptive for the test
> 3. used netlink API to get rss contexts
> 
> v1: https://lore.kernel.org/netdev/20260129061646.1417185-5-michael.chan@broadcom.com/
> ---
>  .../selftests/drivers/net/hw/rss_ctx.py       | 102 +++++++++++++++++-
>  1 file changed, 101 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 ed7e405682f0..f72162ee9dc3 100755
> --- a/tools/testing/selftests/drivers/net/hw/rss_ctx.py
> +++ b/tools/testing/selftests/drivers/net/hw/rss_ctx.py
> @@ -4,11 +4,13 @@
>  import datetime
>  import random
>  import re
> +import time
>  from lib.py import ksft_run, ksft_pr, ksft_exit
>  from lib.py import ksft_eq, ksft_ne, ksft_ge, ksft_in, ksft_lt, ksft_true, ksft_raises
>  from lib.py import NetDrvEpEnv
>  from lib.py import EthtoolFamily, NetdevFamily
>  from lib.py import KsftSkipEx, KsftFailEx
> +from lib.py import ksft_disruptive
>  from lib.py import rand_port
>  from lib.py import ethtool, ip, defer, GenerateTraffic, CmdExitFailure
>  
> @@ -809,6 +811,102 @@ def test_rss_default_context_rule(cfg):
>                            'noise' : (0, 1) })
>  
>  
> +@ksft_disruptive
> +def test_rss_context_persist_ifupdown(cfg, pre_down=False):
> +    """
> +    Test that RSS contexts and their associated ntuple filters persist across
> +    an interface down/up cycle.
> +
> +    """
> +
> +    require_ntuple(cfg)
> +
> +    qcnt = len(_get_rx_cnts(cfg))
> +    if qcnt < 6:
> +        try:
> +            ethtool(f"-L {cfg.ifname} combined 6")
> +            defer(ethtool, f"-L {cfg.ifname} combined {qcnt}")
> +        except:
> +            raise KsftSkipEx("Not enough queues for the test")
> +
> +    ethtool(f"-X {cfg.ifname} equal 2")
> +    defer(ethtool, f"-X {cfg.ifname} default")
> +
> +    if pre_down:
> +        ip(f"link set dev {cfg.ifname} down")
> +
> +    try:
> +        ctx1_id = ethtool_create(cfg, "-X", "context new start 2 equal 2")
> +        defer(ethtool, f"-X {cfg.ifname} context {ctx1_id} delete")
> +    except CmdExitFailure:
> +        if pre_down:
> +            ip(f"link set dev {cfg.ifname} up")
> +            raise KsftSkipEx("Create context not supported with interface down")
> +        raise
> +
> +    ctx2_id = ethtool_create(cfg, "-X", "context new start 4 equal 2")
> +    defer(ethtool, f"-X {cfg.ifname} context {ctx2_id} delete")
> +
> +    port_ctx2 = rand_port()
> +    flow = f"flow-type tcp{cfg.addr_ipver} dst-ip {cfg.addr} dst-port {port_ctx2} context {ctx2_id}"
> +    ntuple_id = ethtool_create(cfg, "-N", flow)
> +    defer(ethtool, f"-N {cfg.ifname} delete {ntuple_id}")
> +
> +    if not pre_down:
> +        ip(f"link set dev {cfg.ifname} down")
> +
> +    ip(f"link set dev {cfg.ifname} up")
> +
> +    import subprocess
> +    max_wait = 10
> +    ping_success = False
> +    remote_addr = cfg.remote_addr_v[cfg.addr_ipver]
> +    for attempt in range(max_wait):
> +        try:
> +            result = subprocess.run(['ping', '-c', '1', '-W', '1', remote_addr],
> +                                  capture_output=True, timeout=2)
> +            if result.returncode == 0:
> +                ping_success = True
> +                break

This might be wanting to use utils.py's cmd()?

> +        except Exception:
> +            pass

> +        time.sleep(1)
> +
> +    if not ping_success:
> +        raise KsftSkipEx("Cannot reach remote host after interface up")
> +
> +    ctxs = cfg.ethnl.rss_get({'header': {'dev-name': cfg.ifname}}, dump=True)
> +
> +    data1 = [c for c in ctxs if c.get('context') == ctx1_id]
> +    ksft_eq(len(data1), 1, f"Context {ctx1_id} should persist after ifup")
> +
> +    data2 = [c for c in ctxs if c.get('context') == ctx2_id]
> +    ksft_eq(len(data2), 1, f"Context {ctx2_id} should persist after ifup")
> +
> +    _ntuple_rule_check(cfg, ntuple_id, ctx2_id)
> +
> +    cnts = _get_rx_cnts(cfg)
> +    GenerateTraffic(cfg).wait_pkts_and_stop(20000)
> +    cnts = _get_rx_cnts(cfg, prev=cnts)
> +
> +    main_traffic = sum(cnts[0:2])
> +    ksft_ge(main_traffic, 18000, f"Main context traffic distribution: {cnts}")
> +    ksft_lt(sum(cnts[2:6]), 500, f"Other context queues should be mostly empty: {cnts}")
> +
> +    _send_traffic_check(cfg, port_ctx2, f"context {ctx2_id}",
> +                        {'target': (4, 5),
> +                         'noise': (0, 1),
> +                         'empty': (2, 3)})
> +
> +
> +def test_rss_context_persist_create_and_ifdown(cfg):
> +    test_rss_context_persist_ifupdown(cfg, pre_down=False)
> +
> +
> +def test_rss_context_persist_ifdown_and_create(cfg):
> +    test_rss_context_persist_ifupdown(cfg, pre_down=True)
> +
> +
>  def main() -> None:
>      with NetDrvEpEnv(__file__, nsim_test=False) as cfg:
>          cfg.context_cnt = None
> @@ -823,7 +921,9 @@ def main() -> None:
>                    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_rss_default_context_rule],
> +                  test_rss_default_context_rule,
> +                  test_rss_context_persist_create_and_ifdown,
> +                  test_rss_context_persist_ifdown_and_create],
>                   args=(cfg, ))
>      ksft_exit()
>  
> -- 
> 2.51.0
>