Re: [PATCH net-next v5 6/6] selftests: net: add rss_multiqueue test variant to iou-zcrx

[David Wei <dw@davidwei.uk>]

On 2026-08-13 18:23, Juanlu Herrero wrote:
> Add a rss_multiqueue Python test variant that exercises multi-queue
> zero-copy receive on a single listening socket.
> 
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
> ---
>   .../selftests/drivers/net/hw/iou-zcrx.py      | 50 ++++++++++++++++++-
>   1 file changed, 48 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
> index b7a225fe4beae..c833535d8a03c 100755
> --- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
> +++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
> @@ -30,6 +30,13 @@ def create_rss_ctx(cfg):
>       return int(values)
>   
>   
> +def create_rss_ctx_multi(cfg, start, count):
> +    """Create an RSS context spanning count queues from start, return its ID."""
> +    output = ethtool(f"-X {cfg.ifname} context new start {start} equal {count}").stdout
> +    values = re.search(r'New RSS context is (\d+)', output).group(1)
> +    return int(values)
> +
> +
>   def set_flow_rule(cfg):
>       output = ethtool(f"-N {cfg.ifname} flow-type tcp6 dst-port {cfg.port} action {cfg.target}").stdout
>       values = re.search(r'ID (\d+)', output).group(1)
> @@ -127,17 +134,56 @@ def _require_ntuple(cfg):
>           defer(ethtool, f"-K {cfg.ifname} ntuple-filters off")
>   
>   
> +def rss_multiqueue(cfg):
> +    """Steer the test flow to a multi-queue RSS context for multi-thread zcrx."""
> +    channels = cfg.ethnl.channels_get({'header': {'dev-index': cfg.ifindex}})
> +    channels = channels['combined-count']
> +    if channels < 3:
> +        raise KsftSkipEx('Test requires NETIF with at least 3 combined channels')
> +
> +    rings = cfg.ethnl.rings_get({'header': {'dev-index': cfg.ifindex}})
> +    rx_rings = rings['rx']
> +    hds_thresh = rings.get('hds-thresh', 0)
> +
> +    cfg.ethnl.rings_set({'header': {'dev-index': cfg.ifindex},
> +                         'tcp-data-split': 'enabled',
> +                         'hds-thresh': 0,
> +                         'rx': 64})
> +    defer(cfg.ethnl.rings_set, {'header': {'dev-index': cfg.ifindex},
> +                                'tcp-data-split': 'unknown',
> +                                'hds-thresh': hds_thresh,
> +                                'rx': rx_rings})
> +    defer(mp_clear_wait, cfg)
> +
> +    cfg.num_threads = 2
> +    cfg.target = channels - cfg.num_threads
> +    ethtool(f"-X {cfg.ifname} equal {cfg.target}")
> +    defer(ethtool, f"-X {cfg.ifname} default")
> +
> +    rss_ctx_id = create_rss_ctx_multi(cfg, cfg.target, cfg.num_threads)
> +    defer(ethtool, f"-X {cfg.ifname} delete context {rss_ctx_id}")
> +
> +    flow_rule_id = set_flow_rule_rss(cfg, rss_ctx_id)
> +    defer(ethtool, f"-N {cfg.ifname} delete {flow_rule_id}")
> +
> +
>   @ksft_variants([
>       KsftNamedVariant("single", single),
>       KsftNamedVariant("rss", rss),
> +    KsftNamedVariant("rss_multiqueue", rss_multiqueue),
>   ])
>   def test_zcrx(cfg, setup) -> None:
>       cfg.require_ipver('6')
>       _require_ntuple(cfg)
>   
> +    cfg.num_threads = 1
> +
>       setup(cfg)
> -    rx_cmd = f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} -q {cfg.target}"
> -    tx_cmd = f"{cfg.bin_remote} -c -h {cfg.addr_v['6']} -p {cfg.port} -l 12840"
> +
> +    rx_cmd = (f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} "
> +              f"-q {cfg.target} -t {cfg.num_threads}")
> +    tx_cmd = (f"{cfg.bin_remote} -c -h {cfg.addr_v['6']} -p {cfg.port} "
> +              f"-l 12840 -t {cfg.num_threads}")
>       with bkg(rx_cmd, exit_wait=True):
>           wait_port_listen(cfg.port, proto="tcp")
>           cmd(tx_cmd, host=cfg.remote)

Reviewed-by: David Wei <dw@davidwei.uk>