selftests: drv-net: Add test for cross-esw rate scheduling

Adds a Python selftest using the YNL devlink API to verify the devlink
rate ops. The test requires a bond device given in the config as NETIF
containing two PFs. Test setup will then create 1 VF on each PF and
verify the various rate commands.

./devlink_rate_cross_esw.py
TAP version 13
1..3
ok 1 devlink_rate_cross_esw.test_same_esw_parent
ok 2 devlink_rate_cross_esw.test_cross_esw_parent
ok 3 devlink_rate_cross_esw.test_tx_rates_on_cross_esw

Tests will be skipped when the preconditions aren't met, when the
devlink API is too old or when the devices don't appear to support
cross-esw scheduling (detected via EOPNOTSUPP).

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260701073254.754518-14-tariqt@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

tools/testing/selftests/drivers/net/hw/Makefile

@@ -20,6 +20,7 @@ TEST_GEN_FILES := \
 TEST_PROGS = \
 	csum.py \
 	devlink_port_split.py \
+	devlink_rate_cross_esw.py \
 	devlink_rate_tc_bw.py \
 	devmem.py \
 	ethtool.sh \

tools/testing/selftests/drivers/net/hw/devlink_rate_cross_esw.py

@@ -0,0 +1,296 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+"""
+Devlink Rate Cross-eswitch Scheduling Test Suite
+==================================================
+
+Control-plane tests for cross-eswitch TX scheduling via devlink-rate.
+Validates that VFs from different PFs on the same chip can share
+rate groups using the cross-device parent-dev attribute.
+
+Preconditions:
+- NETIF points to a bond device with exactly two interfaces.
+- the interfaces must be two PFs from different devices sharing the same chip.
+- (for mlx5): the two interfaces are in switchdev mode and configured in a LAG:
+  - devlink dev eswitch set $DEV1 mode switchdev
+  - devlink dev eswitch set $DEV2 mode switchdev
+  - devlink dev param set $DEV1 name esw_multiport value 1 cmode runtime
+  - devlink dev param set $DEV2 name esw_multiport value 1 cmode runtime
+- test cases will be skipped if:
+  - the number of interfaces in the bond device is != 2.
+  - the kernel doesn't support devlink rates.
+  - the devlink API doesn't support cross-device parents (ENODEV).
+  - cross-esw rate scheduling returns EOPNOTSUPP.
+"""
+
+import errno
+import glob
+import os
+import time
+
+from lib.py import ksft_pr, ksft_eq, ksft_run, ksft_exit
+from lib.py import KsftSkipEx, KsftFailEx
+from lib.py import NetDrvEnv, DevlinkFamily
+from lib.py import NlError
+from lib.py import cmd, defer, ip, tool
+
+
+# --- Discovery and setup ---
+
+
+def get_bond_slaves(bond_ifname):
+    """Returns sorted list of slave netdev names for a bond."""
+    pattern = f"/sys/class/net/{bond_ifname}/lower_*"
+    lowers = glob.glob(pattern)
+    if not lowers:
+        raise KsftSkipEx(f"No bond slaves for {bond_ifname}")
+    slaves = []
+    for path in sorted(lowers):
+        name = os.path.basename(path)
+        if name.startswith("lower_"):
+            name = name[len("lower_"):]
+        slaves.append(name)
+    return slaves
+
+
+def discover_pfs(cfg):
+    """Discovers both PFs from bond slaves."""
+    slaves = get_bond_slaves(cfg.ifname)
+    if len(slaves) != 2:
+        raise KsftSkipEx(f"Need 2 bond slaves, found {len(slaves)}")
+
+    pf0, pf1 = slaves[0], slaves[1]
+    ksft_pr(f"PF0: {pf0} PF1: {pf1}")
+    return pf0, pf1
+
+
+def get_pci_addr(ifname):
+    """Resolves PCI address for a network interface."""
+    return os.path.basename(os.path.realpath(f"/sys/class/net/{ifname}/device"))
+
+
+def get_vf_port_index(pf_pci):
+    """Finds devlink port-index for vf0 under pf_pci."""
+    ports = tool("devlink", "port show", json=True)["port"]
+    for port_name, props in ports.items():
+        if port_name.startswith(f"pci/{pf_pci}/") and props.get("vfnum") == 0:
+            return int(port_name.split("/")[-1])
+    raise KsftSkipEx(f"VF port not found for {pf_pci}")
+
+
+def cleanup_esw(pf):
+    """Removes VFs if created by tests."""
+    cmd(f"echo 0 > /sys/class/net/{pf}/device/sriov_numvfs", shell=True, fail=False)
+
+
+def setup_esw(pf):
+    """Creates 1 VF on 'pf'."""
+    path = f"/sys/class/net/{pf}/device/sriov_numvfs"
+    cmd(f"echo 0 > {path}", shell=True)
+    cmd(f"echo 1 > {path}", shell=True)
+    defer(cleanup_esw, pf)
+    time.sleep(2)
+
+    vf_dir = f"/sys/class/net/{pf}/device/virtfn0/net"
+    entries = os.listdir(vf_dir) if os.path.isdir(vf_dir) else []
+    if not entries:
+        raise KsftSkipEx(f"VF not found for {pf}")
+    ip(f"link set dev {entries[0]} up")
+
+    pf_pci = get_pci_addr(pf)
+    vf_idx = get_vf_port_index(pf_pci)
+    ksft_pr(f"Created VF {vf_idx} on PF {pf} ({pf_pci})")
+    return pf_pci, vf_idx
+
+
+# --- Rate operation helpers ---
+
+
+def rate_new(devnl, dev_pci, node_name, **kwargs):
+    """Creates rate node."""
+    params = {
+        "bus-name": "pci",
+        "dev-name": dev_pci,
+        "rate-node-name": node_name,
+    }
+    params.update(kwargs)
+    try:
+        devnl.rate_new(params)
+    except NlError as e:
+        if e.error == errno.EOPNOTSUPP:
+            raise KsftSkipEx("rate_new not supported") from e
+        raise KsftFailEx("rate_new failed") from e
+
+
+def rate_get(devnl, dev_pci, node_name):
+    """Gets rate node."""
+    params = {
+        "bus-name": "pci",
+        "dev-name": dev_pci,
+        "rate-node-name": node_name,
+    }
+    return devnl.rate_get(params)
+
+
+def rate_get_leaf(devnl, dev_pci, port_index):
+    """Gets rate leaf (VF)."""
+    params = {
+        "bus-name": "pci",
+        "dev-name": dev_pci,
+        "port-index": port_index,
+    }
+    return devnl.rate_get(params)
+
+
+def rate_del(devnl, dev_pci, node_name):
+    """Deletes rate node."""
+    devnl.rate_del({
+        "bus-name": "pci",
+        "dev-name": dev_pci,
+        "rate-node-name": node_name,
+    })
+
+
+def rate_set_leaf(devnl, dev_pci, port_index, **kwargs):
+    """Sets rate attributes on a leaf (VF)."""
+    params = {
+        "bus-name": "pci",
+        "dev-name": dev_pci,
+        "port-index": port_index,
+    }
+    params.update(kwargs)
+    try:
+        devnl.rate_set(params)
+    except NlError as e:
+        if e.error == errno.EOPNOTSUPP:
+            raise KsftSkipEx("rate_set not supported") from e
+        raise KsftFailEx("rate_set failed") from e
+
+
+def rate_set_leaf_parent(devnl, dev_pci, port_index,
+                         parent_name, parent_dev_pci=None):
+    """Sets a leaf's parent, optionally cross-esw."""
+    params = {
+        "bus-name": "pci",
+        "dev-name": dev_pci,
+        "port-index": port_index,
+        "rate-parent-node-name": parent_name,
+    }
+    if parent_dev_pci:
+        params["parent-dev"] = {
+            "bus-name": "pci",
+            "dev-name": parent_dev_pci,
+        }
+    try:
+        devnl.rate_set(params)
+    except NlError as e:
+        if e.error == errno.EOPNOTSUPP:
+            raise KsftSkipEx("rate_set not supported") from e
+        if parent_dev_pci and e.error == errno.ENODEV:
+            raise KsftSkipEx("Cross-esw scheduling not supported") from e
+        raise KsftFailEx("rate_set failed") from e
+
+
+def rate_clear_leaf_parent(devnl, dev_pci, port_index):
+    """Clears a leaf's parent."""
+    rate_set_leaf_parent(devnl, dev_pci, port_index, "")
+
+
+def rate_set_node(devnl, dev_pci, node_name, **kwargs):
+    """Sets rate attributes on a node."""
+    params = {
+        "bus-name": "pci",
+        "dev-name": dev_pci,
+        "rate-node-name": node_name,
+    }
+    params.update(kwargs)
+    devnl.rate_set(params)
+
+
+# --- Test cases ---
+
+
+def test_same_esw_parent(cfg):
+    """Assigns PF0's VF to PF0's group (same esw baseline)."""
+    pf0, _ = discover_pfs(cfg)
+    pf0_pci, vf0_idx = setup_esw(pf0)
+
+    rate_new(cfg.devnl, pf0_pci, "group0")
+    defer(rate_del, cfg.devnl, pf0_pci, "group0")
+    ksft_pr("rate-new succeeded")
+
+    rate_set_leaf_parent(cfg.devnl, pf0_pci, vf0_idx, "group0")
+    defer(rate_clear_leaf_parent, cfg.devnl, pf0_pci, vf0_idx)
+
+    ksft_pr("Same-esw parent assignment succeeded")
+
+
+def test_cross_esw_parent(cfg):
+    """Sets cross-esw parent, then clear it."""
+    pf0, pf1 = discover_pfs(cfg)
+    pf0_pci, _ = setup_esw(pf0)
+    pf1_pci, vf1_idx = setup_esw(pf1)
+
+    rate_new(cfg.devnl, pf0_pci, "group1")
+    defer(rate_del, cfg.devnl, pf0_pci, "group1")
+    ksft_pr("rate-new succeeded")
+
+    rate_set_leaf_parent(cfg.devnl, pf1_pci, vf1_idx,
+                         "group1", parent_dev_pci=pf0_pci)
+    defer(rate_clear_leaf_parent, cfg.devnl, pf1_pci, vf1_idx)
+
+    ksft_pr("Cross-esw parent set and clear succeeded")
+
+
+def test_tx_rates_on_cross_esw(cfg):
+    """Sets tx_max on group and tx_share on leaves in a cross-esw setup."""
+    pf0, pf1 = discover_pfs(cfg)
+    pf0_pci, vf0_idx = setup_esw(pf0)
+    pf1_pci, vf1_idx = setup_esw(pf1)
+
+    rate_new(cfg.devnl, pf0_pci, "group2", **{"rate-tx-max": 10000000})
+    defer(rate_del, cfg.devnl, pf0_pci, "group2")
+    ksft_pr("rate-new succeeded")
+
+    rate_set_leaf_parent(cfg.devnl, pf1_pci, vf1_idx,
+                         "group2", parent_dev_pci=pf0_pci)
+    defer(rate_clear_leaf_parent, cfg.devnl, pf1_pci, vf1_idx)
+    ksft_pr("set parent cross-esw succeeded")
+
+    rate_set_leaf_parent(cfg.devnl, pf0_pci, vf0_idx, "group2")
+    defer(rate_clear_leaf_parent, cfg.devnl, pf0_pci, vf0_idx)
+    ksft_pr("set parent same esw succeeded")
+
+    rate_set_leaf(cfg.devnl, pf0_pci, vf0_idx, **{"rate-tx-share": 1000000})
+    rate = rate_get_leaf(cfg.devnl, pf0_pci, vf0_idx)
+    ksft_eq(rate["rate-tx-share"], 1000000)
+    rate_set_leaf(cfg.devnl, pf1_pci, vf1_idx, **{"rate-tx-share": 2000000})
+    rate = rate_get_leaf(cfg.devnl, pf1_pci, vf1_idx)
+    ksft_eq(rate["rate-tx-share"], 2000000)
+    rate_set_node(cfg.devnl, pf0_pci, "group2", **{"rate-tx-max": 250000000})
+    rate = rate_get(cfg.devnl, pf0_pci, "group2")
+    ksft_eq(rate["rate-tx-max"], 250000000)
+
+    ksft_pr("tx_max and tx_share set on cross-esw group")
+
+
+def main() -> None:
+    """Main function."""
+
+    with NetDrvEnv(__file__, nsim_test=False) as cfg:
+        cfg.devnl = DevlinkFamily()
+
+        ksft_run(
+            cases=[
+                test_same_esw_parent,
+                test_cross_esw_parent,
+                test_tx_rates_on_cross_esw,
+            ],
+            args=(cfg,),
+        )
+    ksft_exit()
+
+
+if __name__ == "__main__":
+    main()