Re: [PATCH net-next 1/4] selftests/net: Move netkit lease hw setup into per-test fixtures

[Bobby Eshleman <bobbyeshleman@gmail.com>]

On Wed, Jun 10, 2026 at 10:03:41AM +0200, Daniel Borkmann wrote:
> The HW counterpart of nk_qlease.py was carrying its lease setup in main()
> and stashing src_queue / nk_queue / nk_*_ifname on cfg, which had drawbacks
> called out during the review at [0].
> 
> This is the deferred half of the cleanup that landed in commit e254ffb9502c
> ("selftests/net: Split netdevsim tests from HW tests in nk_qlease") which
> was the SW counterpart of nk_qlease.py.
> 
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
> Link: https://lore.kernel.org/netdev/20260408162238.16709090@kernel.org/ [0]
> ---
>  .../selftests/drivers/net/hw/nk_qlease.py     | 192 +++++++++++++-----
>  1 file changed, 146 insertions(+), 46 deletions(-)
> 
> diff --git a/tools/testing/selftests/drivers/net/hw/nk_qlease.py b/tools/testing/selftests/drivers/net/hw/nk_qlease.py
> index 139a91ebd229..81125856727f 100755
> --- a/tools/testing/selftests/drivers/net/hw/nk_qlease.py
> +++ b/tools/testing/selftests/drivers/net/hw/nk_qlease.py
> @@ -18,8 +18,10 @@ from lib.py import (
>      NetNSEnter,
>      EthtoolFamily,
>      NetdevFamily,
> +    RtnlFamily,
>  )
>  from lib.py import (
> +    Netlink,
>      bkg,
>      cmd,
>      defer,
> @@ -31,9 +33,117 @@ from lib.py import (
>  from lib.py import KsftSkipEx, CmdExitFailure
>  
>  
> -def set_flow_rule(cfg):
> +def _create_netkit_pair(cfg, rxqueues=2):
> +    if cfg._nk_host_ifname:
> +        cmd(f"ip link del dev {cfg._nk_host_ifname}", fail=False)
> +        cfg._nk_host_ifname = None
> +        cfg.nk_guest_ifname = None
> +    if getattr(cfg, "_tc_attached", False):
> +        cmd(
> +            f"tc filter del dev {cfg.ifname} ingress pref {cfg._bpf_prog_pref}",
> +            fail=False,
> +        )
> +        cfg._tc_attached = False
> +
> +    all_links = ip("-d link show", json=True)
> +    old_idxs = {
> +        link["ifindex"]
> +        for link in all_links
> +        if link.get("linkinfo", {}).get("info_kind") == "netkit"
> +    }
> +
> +    rtnl = RtnlFamily()
> +    rtnl.newlink(
> +        {
> +            "linkinfo": {
> +                "kind": "netkit",
> +                "data": {
> +                    "mode": "l2",
> +                    "policy": "forward",
> +                    "peer-policy": "forward",
> +                },
> +            },
> +            "num-rx-queues": rxqueues,
> +        },
> +        flags=[Netlink.NLM_F_CREATE, Netlink.NLM_F_EXCL],
> +    )
> +
> +    all_links = ip("-d link show", json=True)
> +    nk_links = [
> +        link
> +        for link in all_links
> +        if link.get("linkinfo", {}).get("info_kind") == "netkit"
> +        and link["ifindex"] not in old_idxs
> +    ]
> +    if len(nk_links) != 2:
> +        raise KsftSkipEx("Failed to create netkit pair")
> +
> +    nk_links.sort(key=lambda x: x["ifindex"])
> +    cfg._nk_host_ifname = nk_links[1]["ifname"]
> +    cfg.nk_guest_ifname = nk_links[0]["ifname"]
> +    cfg.nk_host_ifindex = nk_links[1]["ifindex"]
> +    cfg.nk_guest_ifindex = nk_links[0]["ifindex"]
> +
> +    ip(f"link set dev {cfg.nk_guest_ifname} netns {cfg.netns.name}")
> +    ip(f"link set dev {cfg._nk_host_ifname} up")
> +    ip(f"-6 addr add fe80::1/64 dev {cfg._nk_host_ifname} nodad")
> +    ip(
> +        f"-6 route add {cfg.nk_guest_ipv6}/128 via fe80::2 "
> +        f"dev {cfg._nk_host_ifname}"
> +    )
> +    ip(f"link set dev {cfg.nk_guest_ifname} up", ns=cfg.netns)
> +    ip(f"-6 addr add fe80::2/64 dev {cfg.nk_guest_ifname}", ns=cfg.netns)
> +    ip(
> +        f"-6 addr add {cfg.nk_guest_ipv6}/64 dev {cfg.nk_guest_ifname} nodad",
> +        ns=cfg.netns,
> +    )
> +    ip(
> +        f"-6 route add default via fe80::1 dev {cfg.nk_guest_ifname}",
> +        ns=cfg.netns,
> +    )
> +
> +    cfg._attach_bpf()
> +
> +
> +def _setup_lease(cfg, rxqueues=2):
> +    _create_netkit_pair(cfg, rxqueues=rxqueues)
> +
> +    ethnl = EthtoolFamily()
> +    channels = ethnl.channels_get({"header": {"dev-index": cfg.ifindex}})[
> +        "combined-count"
> +    ]
> +    if channels < 2:
> +        raise KsftSkipEx(
> +            "Test requires NETIF with at least 2 combined channels"
> +        )
> +    src_queue = channels - 1
> +
> +    with NetNSEnter(str(cfg.netns)):
> +        netdevnl = NetdevFamily()
> +        bind_result = netdevnl.queue_create(
> +            {
> +                "ifindex": cfg.nk_guest_ifindex,
> +                "type": "rx",
> +                "lease": {
> +                    "ifindex": cfg.ifindex,
> +                    "queue": {"id": src_queue, "type": "rx"},
> +                    "netns-id": 0,
> +                },
> +            }
> +        )
> +    return src_queue, bind_result["id"]
> +
> +
> +def _teardown_netkit(cfg):
> +    if cfg._nk_host_ifname:
> +        cmd(f"ip link del dev {cfg._nk_host_ifname}", fail=False)
> +        cfg._nk_host_ifname = None
> +        cfg.nk_guest_ifname = None
> +
> +
> +def set_flow_rule(cfg, src_queue):
>      output = ethtool(
> -        f"-N {cfg.ifname} flow-type tcp6 dst-port {cfg.port} action {cfg.src_queue}"
> +        f"-N {cfg.ifname} flow-type tcp6 dst-port {cfg.port} action {src_queue}"
>      ).stdout
>      values = re.search(r"ID (\d+)", output).group(1)
>      return int(values)
> @@ -41,6 +151,8 @@ def set_flow_rule(cfg):
>  
>  def test_iou_zcrx(cfg) -> None:
>      cfg.require_ipver("6")
> +    src_queue, nk_queue = _setup_lease(cfg)
> +    defer(_teardown_netkit, cfg)
>      ethnl = EthtoolFamily()
>  
>      rings = ethnl.rings_get({"header": {"dev-index": cfg.ifindex}})
> @@ -65,13 +177,16 @@ def test_iou_zcrx(cfg) -> None:
>          },
>      )
>  
> -    ethtool(f"-X {cfg.ifname} equal {cfg.src_queue}")
> +    ethtool(f"-X {cfg.ifname} equal {src_queue}")
>      defer(ethtool, f"-X {cfg.ifname} default")
>  
> -    flow_rule_id = set_flow_rule(cfg)
> +    flow_rule_id = set_flow_rule(cfg, src_queue)
>      defer(ethtool, f"-N {cfg.ifname} delete {flow_rule_id}")
>  
> -    rx_cmd = f"ip netns exec {cfg.netns.name} {cfg.bin_local} -s -p {cfg.port} -i {cfg.nk_guest_ifname} -q {cfg.nk_queue}"
> +    rx_cmd = (
> +        f"ip netns exec {cfg.netns.name} {cfg.bin_local} "
> +        f"-s -p {cfg.port} -i {cfg.nk_guest_ifname} -q {nk_queue}"
> +    )
>      tx_cmd = f"{cfg.bin_remote} -c -h {cfg.nk_guest_ipv6} -p {cfg.port} -l 12840"
>      with bkg(rx_cmd, exit_wait=True):
>          wait_port_listen(cfg.port, proto="tcp", ns=cfg.netns)
> @@ -80,25 +195,29 @@ def test_iou_zcrx(cfg) -> None:
>  
>  def test_attrs(cfg) -> None:
>      cfg.require_ipver("6")
> +    src_queue, nk_queue = _setup_lease(cfg)
> +    defer(_teardown_netkit, cfg)
>      netdevnl = NetdevFamily()
>      queue_info = netdevnl.queue_get(
> -        {"ifindex": cfg.ifindex, "id": cfg.src_queue, "type": "rx"}
> +        {"ifindex": cfg.ifindex, "id": src_queue, "type": "rx"}
>      )
>  
> -    ksft_eq(queue_info["id"], cfg.src_queue)
> +    ksft_eq(queue_info["id"], src_queue)
>      ksft_eq(queue_info["type"], "rx")
>      ksft_eq(queue_info["ifindex"], cfg.ifindex)
>  
>      ksft_in("lease", queue_info)
>      lease = queue_info["lease"]
>      ksft_eq(lease["ifindex"], cfg.nk_guest_ifindex)
> -    ksft_eq(lease["queue"]["id"], cfg.nk_queue)
> +    ksft_eq(lease["queue"]["id"], nk_queue)
>      ksft_eq(lease["queue"]["type"], "rx")
>      ksft_in("netns-id", lease)
>  
>  
>  def test_attach_xdp_with_mp(cfg) -> None:
>      cfg.require_ipver("6")
> +    src_queue, nk_queue = _setup_lease(cfg)
> +    defer(_teardown_netkit, cfg)
>      ethnl = EthtoolFamily()
>  
>      rings = ethnl.rings_get({"header": {"dev-index": cfg.ifindex}})
> @@ -123,18 +242,21 @@ def test_attach_xdp_with_mp(cfg) -> None:
>          },
>      )
>  
> -    ethtool(f"-X {cfg.ifname} equal {cfg.src_queue}")
> +    ethtool(f"-X {cfg.ifname} equal {src_queue}")
>      defer(ethtool, f"-X {cfg.ifname} default")
>  
>      netdevnl = NetdevFamily()
>  
> -    rx_cmd = f"ip netns exec {cfg.netns.name} {cfg.bin_local} -s -p {cfg.port} -i {cfg.nk_guest_ifname} -q {cfg.nk_queue}"
> +    rx_cmd = (
> +        f"ip netns exec {cfg.netns.name} {cfg.bin_local} "
> +        f"-s -p {cfg.port} -i {cfg.nk_guest_ifname} -q {nk_queue}"
> +    )
>      with bkg(rx_cmd):
>          wait_port_listen(cfg.port, proto="tcp", ns=cfg.netns)
>  
>          time.sleep(0.1)
>          queue_info = netdevnl.queue_get(
> -            {"ifindex": cfg.ifindex, "id": cfg.src_queue, "type": "rx"}
> +            {"ifindex": cfg.ifindex, "id": src_queue, "type": "rx"}
>          )
>          ksft_in("io-uring", queue_info)
>  
> @@ -144,13 +266,15 @@ def test_attach_xdp_with_mp(cfg) -> None:
>  
>      time.sleep(0.1)
>      queue_info = netdevnl.queue_get(
> -        {"ifindex": cfg.ifindex, "id": cfg.src_queue, "type": "rx"}
> +        {"ifindex": cfg.ifindex, "id": src_queue, "type": "rx"}
>      )
>      ksft_not_in("io-uring", queue_info)
>  
>  
>  def test_destroy(cfg) -> None:
>      cfg.require_ipver("6")
> +    src_queue, nk_queue = _setup_lease(cfg)
> +    defer(_teardown_netkit, cfg)
>      ethnl = EthtoolFamily()
>  
>      rings = ethnl.rings_get({"header": {"dev-index": cfg.ifindex}})
> @@ -175,16 +299,19 @@ def test_destroy(cfg) -> None:
>          },
>      )
>  
> -    ethtool(f"-X {cfg.ifname} equal {cfg.src_queue}")
> +    ethtool(f"-X {cfg.ifname} equal {src_queue}")
>      defer(ethtool, f"-X {cfg.ifname} default")
>  
> -    rx_cmd = f"ip netns exec {cfg.netns.name} {cfg.bin_local} -s -p {cfg.port} -i {cfg.nk_guest_ifname} -q {cfg.nk_queue}"
> +    rx_cmd = (
> +        f"ip netns exec {cfg.netns.name} {cfg.bin_local} "
> +        f"-s -p {cfg.port} -i {cfg.nk_guest_ifname} -q {nk_queue}"
> +    )
>      rx_proc = cmd(rx_cmd, background=True)
>      wait_port_listen(cfg.port, proto="tcp", ns=cfg.netns)
>  
>      netdevnl = NetdevFamily()
>      queue_info = netdevnl.queue_get(
> -        {"ifindex": cfg.ifindex, "id": cfg.src_queue, "type": "rx"}
> +        {"ifindex": cfg.ifindex, "id": src_queue, "type": "rx"}
>      )
>      ksft_in("io-uring", queue_info)
>  
> @@ -199,17 +326,14 @@ def test_destroy(cfg) -> None:
>      cfg.nk_guest_ifname = None
>  
>      queue_info = netdevnl.queue_get(
> -        {"ifindex": cfg.ifindex, "id": cfg.src_queue, "type": "rx"}
> +        {"ifindex": cfg.ifindex, "id": src_queue, "type": "rx"}
>      )
>      ksft_not_in("io-uring", queue_info)
>  
> -    cmd(f"tc filter del dev {cfg.ifname} ingress pref {cfg._bpf_prog_pref}")
> -    cfg._tc_attached = False
> -
> -    flow_rule_id = set_flow_rule(cfg)
> +    flow_rule_id = set_flow_rule(cfg, src_queue)
>      defer(ethtool, f"-N {cfg.ifname} delete {flow_rule_id}")
>  
> -    rx_cmd = f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} -q {cfg.src_queue}"
> +    rx_cmd = f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} -q {src_queue}"
>      tx_cmd = f"{cfg.bin_remote} -c -h {cfg.addr_v['6']} -p {cfg.port} -l 12840"
>      with bkg(rx_cmd, exit_wait=True):
>          wait_port_listen(cfg.port, proto="tcp")
> @@ -217,7 +341,7 @@ def test_destroy(cfg) -> None:
>      # Short delay since iou cleanup is async and takes a bit of time.
>      time.sleep(0.1)
>      queue_info = netdevnl.queue_get(
> -        {"ifindex": cfg.ifindex, "id": cfg.src_queue, "type": "rx"}
> +        {"ifindex": cfg.ifindex, "id": src_queue, "type": "rx"}
>      )
>      ksft_not_in("io-uring", queue_info)
>  
> @@ -230,30 +354,6 @@ def main() -> None:
>          cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)
>          cfg.port = rand_port()
>  
> -        ethnl = EthtoolFamily()
> -        channels = ethnl.channels_get({"header": {"dev-index": cfg.ifindex}})
> -        channels = channels["combined-count"]
> -        if channels < 2:
> -            raise KsftSkipEx("Test requires NETIF with at least 2 combined channels")
> -
> -        cfg.src_queue = channels - 1
> -
> -        with NetNSEnter(str(cfg.netns)):
> -            netdevnl = NetdevFamily()
> -            bind_result = netdevnl.queue_create(
> -                {
> -                    "ifindex": cfg.nk_guest_ifindex,
> -                    "type": "rx",
> -                    "lease": {
> -                        "ifindex": cfg.ifindex,
> -                        "queue": {"id": cfg.src_queue, "type": "rx"},
> -                        "netns-id": 0,
> -                    },
> -                }
> -            )
> -            cfg.nk_queue = bind_result["id"]
> -
> -        # test_destroy must be last because it destroys the netkit devices
>          ksft_run(
>              [test_iou_zcrx, test_attrs, test_attach_xdp_with_mp, test_destroy],
>              args=(cfg,),
> -- 
> 2.43.0
> 

Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>