selftests: drv-net: rss_ctx: add tests for RSS configuration and contexts

Add tests focusing on indirection table configuration and
creating extra RSS contexts in drivers which support it.

$ export NETIF=eth0 REMOTE_...
$ ./drivers/net/hw/rss_ctx.py
KTAP version 1
1..8
ok 1 rss_ctx.test_rss_key_indir
ok 2 rss_ctx.test_rss_context
ok 3 rss_ctx.test_rss_context4
# Increasing queue count 44 -> 66
# Failed to create context 32, trying to test what we got
ok 4 rss_ctx.test_rss_context32 # SKIP Tested only 31 contexts, wanted 32
ok 5 rss_ctx.test_rss_context_overlap
ok 6 rss_ctx.test_rss_context_overlap2
# .. sprays traffic like a headless chicken ..
not ok 7 rss_ctx.test_rss_context_out_of_order
ok 8 rss_ctx.test_rss_context4_create_with_cfg
# Totals: pass:6 fail:1 xfail:0 xpass:0 skip:1 error:0

Note that rss_ctx.test_rss_context_out_of_order fails with the device
I tested with, but it seems to be a device / driver bug.

Reviewed-by: Petr Machata <[e-mail]>
Reviewed-by: Willem de Bruijn <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

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

···
 	hw_stats_l3_gre.sh \
 	loopback.sh \
 	pp_alloc_fail.py \
+	rss_ctx.py \
 	#
 
 TEST_FILES := \

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

···
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import datetime
+import random
+from lib.py import ksft_run, ksft_pr, ksft_exit, ksft_eq, ksft_ge, ksft_lt
+from lib.py import NetDrvEpEnv
+from lib.py import NetdevFamily
+from lib.py import KsftSkipEx
+from lib.py import rand_port
+from lib.py import ethtool, ip, GenerateTraffic, CmdExitFailure
+
+
+def _rss_key_str(key):
+    return ":".join(["{:02x}".format(x) for x in key])
+
+
+def _rss_key_rand(length):
+    return [random.randint(0, 255) for _ in range(length)]
+
+
+def get_rss(cfg, context=0):
+    return ethtool(f"-x {cfg.ifname} context {context}", json=True)[0]
+
+
+def get_drop_err_sum(cfg):
+    stats = ip("-s -s link show dev " + cfg.ifname, json=True)[0]
+    cnt = 0
+    for key in ['errors', 'dropped', 'over_errors', 'fifo_errors',
+                'length_errors', 'crc_errors', 'missed_errors',
+                'frame_errors']:
+        cnt += stats["stats64"]["rx"][key]
+    return cnt, stats["stats64"]["tx"]["carrier_changes"]
+
+
+def ethtool_create(cfg, act, opts):
+    output = ethtool(f"{act} {cfg.ifname} {opts}").stdout
+    # Output will be something like: "New RSS context is 1" or
+    # "Added rule with ID 7", we want the integer from the end
+    return int(output.split()[-1])
+
+
+def require_ntuple(cfg):
+    features = ethtool(f"-k {cfg.ifname}", json=True)[0]
+    if not features["ntuple-filters"]["active"]:
+        # ntuple is more of a capability than a config knob, don't bother
+        # trying to enable it (until some driver actually needs it).
+        raise KsftSkipEx("Ntuple filters not enabled on the device: " + str(features["ntuple-filters"]))
+
+
+# Get Rx packet counts for all queues, as a simple list of integers
+# if @prev is specified the prev counts will be subtracted
+def _get_rx_cnts(cfg, prev=None):
+    cfg.wait_hw_stats_settle()
+    data = cfg.netdevnl.qstats_get({"ifindex": cfg.ifindex, "scope": ["queue"]}, dump=True)
+    data = [x for x in data if x['queue-type'] == "rx"]
+    max_q = max([x["queue-id"] for x in data])
+    queue_stats = [0] * (max_q + 1)
+    for q in data:
+        queue_stats[q["queue-id"]] = q["rx-packets"]
+        if prev and q["queue-id"] < len(prev):
+            queue_stats[q["queue-id"]] -= prev[q["queue-id"]]
+    return queue_stats
+
+
+def test_rss_key_indir(cfg):
+    """
+    Test basics like updating the main RSS key and indirection table.
+    """
+    if len(_get_rx_cnts(cfg)) < 2:
+        KsftSkipEx("Device has only one queue (or doesn't support queue stats)")
+
+    data = get_rss(cfg)
+    want_keys = ['rss-hash-key', 'rss-hash-function', 'rss-indirection-table']
+    for k in want_keys:
+        if k not in data:
+            raise KsftFailEx("ethtool results missing key: " + k)
+        if not data[k]:
+            raise KsftFailEx(f"ethtool results empty for '{k}': {data[k]}")
+
+    key_len = len(data['rss-hash-key'])
+
+    # Set the key
+    key = _rss_key_rand(key_len)
+    ethtool(f"-X {cfg.ifname} hkey " + _rss_key_str(key))
+
+    data = get_rss(cfg)
+    ksft_eq(key, data['rss-hash-key'])
+
+    # Set the indirection table
+    ethtool(f"-X {cfg.ifname} equal 2")
+    data = get_rss(cfg)
+    ksft_eq(0, min(data['rss-indirection-table']))
+    ksft_eq(1, max(data['rss-indirection-table']))
+
+    # Check we only get traffic on the first 2 queues
+    cnts = _get_rx_cnts(cfg)
+    GenerateTraffic(cfg).wait_pkts_and_stop(20000)
+    cnts = _get_rx_cnts(cfg, prev=cnts)
+    # 2 queues, 20k packets, must be at least 5k per queue
+    ksft_ge(cnts[0], 5000, "traffic on main context (1/2): " + str(cnts))
+    ksft_ge(cnts[1], 5000, "traffic on main context (2/2): " + str(cnts))
+    # The other queues should be unused
+    ksft_eq(sum(cnts[2:]), 0, "traffic on unused queues: " + str(cnts))
+
+    # Restore, and check traffic gets spread again
+    ethtool(f"-X {cfg.ifname} default")
+
+    cnts = _get_rx_cnts(cfg)
+    GenerateTraffic(cfg).wait_pkts_and_stop(20000)
+    cnts = _get_rx_cnts(cfg, prev=cnts)
+    # First two queues get less traffic than all the rest
+    ksft_lt(sum(cnts[:2]), sum(cnts[2:]), "traffic distributed: " + str(cnts))
+
+
+def test_rss_context(cfg, ctx_cnt=1, create_with_cfg=None):
+    """
+    Test separating traffic into RSS contexts.
+    The queues will be allocated 2 for each context:
+     ctx0  ctx1  ctx2  ctx3
+    [0 1] [2 3] [4 5] [6 7] ...
+    """
+
+    require_ntuple(cfg)
+
+    requested_ctx_cnt = ctx_cnt
+
+    # Try to allocate more queues when necessary
+    qcnt = len(_get_rx_cnts(cfg))
+    if qcnt >= 2 + 2 * ctx_cnt:
+        qcnt = None
+    else:
+        try:
+            ksft_pr(f"Increasing queue count {qcnt} -> {2 + 2 * ctx_cnt}")
+            ethtool(f"-L {cfg.ifname} combined {2 + 2 * ctx_cnt}")
+        except:
+            raise KsftSkipEx("Not enough queues for the test")
+
+    ntuple = []
+    ctx_id = []
+    ports = []
+    try:
+        # Use queues 0 and 1 for normal traffic
+        ethtool(f"-X {cfg.ifname} equal 2")
+
+        for i in range(ctx_cnt):
+            want_cfg = f"start {2 + i * 2} equal 2"
+            create_cfg = want_cfg if create_with_cfg else ""
+
+            try:
+                ctx_id.append(ethtool_create(cfg, "-X", f"context new {create_cfg}"))
+            except CmdExitFailure:
+                # try to carry on and skip at the end
+                if i == 0:
+                    raise
+                ksft_pr(f"Failed to create context {i + 1}, trying to test what we got")
+                ctx_cnt = i
+                break
+
+            if not create_with_cfg:
+                ethtool(f"-X {cfg.ifname} context {ctx_id[i]} {want_cfg}")
+
+            # Sanity check the context we just created
+            data = get_rss(cfg, ctx_id[i])
+            ksft_eq(min(data['rss-indirection-table']), 2 + i * 2, "Unexpected context cfg: " + str(data))
+            ksft_eq(max(data['rss-indirection-table']), 2 + i * 2 + 1, "Unexpected context cfg: " + str(data))
+
+            ports.append(rand_port())
+            flow = f"flow-type tcp{cfg.addr_ipver} dst-port {ports[i]} context {ctx_id[i]}"
+            ntuple.append(ethtool_create(cfg, "-N", flow))
+
+        for i in range(ctx_cnt):
+            cnts = _get_rx_cnts(cfg)
+            GenerateTraffic(cfg, port=ports[i]).wait_pkts_and_stop(20000)
+            cnts = _get_rx_cnts(cfg, prev=cnts)
+
+            ksft_lt(sum(cnts[ :2]), 10000, "traffic on main context:" + str(cnts))
+            ksft_ge(sum(cnts[2+i*2:4+i*2]), 20000, f"traffic on context {i}: " + str(cnts))
+            ksft_eq(sum(cnts[2:2+i*2] + cnts[4+i*2:]), 0, "traffic on other contexts: " + str(cnts))
+    finally:
+        for nid in ntuple:
+            ethtool(f"-N {cfg.ifname} delete {nid}")
+        for cid in ctx_id:
+            ethtool(f"-X {cfg.ifname} context {cid} delete")
+        ethtool(f"-X {cfg.ifname} default")
+        if qcnt:
+            ethtool(f"-L {cfg.ifname} combined {qcnt}")
+
+    if requested_ctx_cnt != ctx_cnt:
+        raise KsftSkipEx(f"Tested only {ctx_cnt} contexts, wanted {requested_ctx_cnt}")
+
+
+def test_rss_context4(cfg):
+    test_rss_context(cfg, 4)
+
+
+def test_rss_context32(cfg):
+    test_rss_context(cfg, 32)
+
+
+def test_rss_context4_create_with_cfg(cfg):
+    test_rss_context(cfg, 4, create_with_cfg=True)
+
+
+def test_rss_context_out_of_order(cfg, ctx_cnt=4):
+    """
+    Test separating traffic into RSS contexts.
+    Contexts are removed in semi-random order, and steering re-tested
+    to make sure removal doesn't break steering to surviving contexts.
+    Test requires 3 contexts to work.
+    """
+
+    require_ntuple(cfg)
+
+    requested_ctx_cnt = ctx_cnt
+
+    # Try to allocate more queues when necessary
+    qcnt = len(_get_rx_cnts(cfg))
+    if qcnt >= 2 + 2 * ctx_cnt:
+        qcnt = None
+    else:
+        try:
+            ksft_pr(f"Increasing queue count {qcnt} -> {2 + 2 * ctx_cnt}")
+            ethtool(f"-L {cfg.ifname} combined {2 + 2 * ctx_cnt}")
+        except:
+            raise KsftSkipEx("Not enough queues for the test")
+
+    ntuple = []
+    ctx_id = []
+    ports = []
+
+    def remove_ctx(idx):
+        ethtool(f"-N {cfg.ifname} delete {ntuple[idx]}")
+        ntuple[idx] = None
+        ethtool(f"-X {cfg.ifname} context {ctx_id[idx]} delete")
+        ctx_id[idx] = None
+
+    def check_traffic():
+        for i in range(ctx_cnt):
+            cnts = _get_rx_cnts(cfg)
+            GenerateTraffic(cfg, port=ports[i]).wait_pkts_and_stop(20000)
+            cnts = _get_rx_cnts(cfg, prev=cnts)
+
+            if ctx_id[i] is None:
+                ksft_lt(sum(cnts[ :2]), 10000, "traffic on main context:" + str(cnts))
+                ksft_ge(sum(cnts[2+i*2:4+i*2]), 20000, f"traffic on context {i}: " + str(cnts))
+                ksft_eq(sum(cnts[2:2+i*2] + cnts[4+i*2:]), 0, "traffic on other contexts: " + str(cnts))
+            else:
+                ksft_ge(sum(cnts[ :2]), 20000, "traffic on main context:" + str(cnts))
+                ksft_eq(sum(cnts[2: ]),     0, "traffic on other contexts: " + str(cnts))
+
+    try:
+        # Use queues 0 and 1 for normal traffic
+        ethtool(f"-X {cfg.ifname} equal 2")
+
+        for i in range(ctx_cnt):
+            ctx_id.append(ethtool_create(cfg, "-X", f"context new start {2 + i * 2} equal 2"))
+
+            ports.append(rand_port())
+            flow = f"flow-type tcp{cfg.addr_ipver} dst-port {ports[i]} context {ctx_id[i]}"
+            ntuple.append(ethtool_create(cfg, "-N", flow))
+
+        check_traffic()
+
+        # Remove middle context
+        remove_ctx(ctx_cnt // 2)
+        check_traffic()
+
+        # Remove first context
+        remove_ctx(0)
+        check_traffic()
+
+        # Remove last context
+        remove_ctx(-1)
+        check_traffic()
+
+    finally:
+        for nid in ntuple:
+            if nid is not None:
+                ethtool(f"-N {cfg.ifname} delete {nid}")
+        for cid in ctx_id:
+            if cid is not None:
+                ethtool(f"-X {cfg.ifname} context {cid} delete")
+        ethtool(f"-X {cfg.ifname} default")
+        if qcnt:
+            ethtool(f"-L {cfg.ifname} combined {qcnt}")
+
+    if requested_ctx_cnt != ctx_cnt:
+        raise KsftSkipEx(f"Tested only {ctx_cnt} contexts, wanted {requested_ctx_cnt}")
+
+
+def test_rss_context_overlap(cfg, other_ctx=0):
+    """
+    Test contexts overlapping with each other.
+    Use 4 queues for the main context, but only queues 2 and 3 for context 1.
+    """
+
+    require_ntuple(cfg)
+
+    queue_cnt = len(_get_rx_cnts(cfg))
+    if queue_cnt >= 4:
+        queue_cnt = None
+    else:
+        try:
+            ksft_pr(f"Increasing queue count {queue_cnt} -> 4")
+            ethtool(f"-L {cfg.ifname} combined 4")
+        except:
+            raise KsftSkipEx("Not enough queues for the test")
+
+    ctx_id = None
+    ntuple = None
+    if other_ctx == 0:
+        ethtool(f"-X {cfg.ifname} equal 4")
+    else:
+        other_ctx = ethtool_create(cfg, "-X", "context new")
+        ethtool(f"-X {cfg.ifname} context {other_ctx} equal 4")
+
+    try:
+        ctx_id = ethtool_create(cfg, "-X", "context new")
+        ethtool(f"-X {cfg.ifname} context {ctx_id} start 2 equal 2")
+
+        port = rand_port()
+        if other_ctx:
+            flow = f"flow-type tcp{cfg.addr_ipver} dst-port {port} context {other_ctx}"
+            ntuple = ethtool_create(cfg, "-N", flow)
+
+        # Test the main context
+        cnts = _get_rx_cnts(cfg)
+        GenerateTraffic(cfg, port=port).wait_pkts_and_stop(20000)
+        cnts = _get_rx_cnts(cfg, prev=cnts)
+
+        ksft_ge(sum(cnts[ :4]), 20000, "traffic on main context: " + str(cnts))
+        ksft_ge(sum(cnts[ :2]),  7000, "traffic on main context (1/2): " + str(cnts))
+        ksft_ge(sum(cnts[2:4]),  7000, "traffic on main context (2/2): " + str(cnts))
+        if other_ctx == 0:
+            ksft_eq(sum(cnts[4: ]),     0, "traffic on other queues: " + str(cnts))
+
+        # Now create a rule for context 1 and make sure traffic goes to a subset
+        if other_ctx:
+            ethtool(f"-N {cfg.ifname} delete {ntuple}")
+            ntuple = None
+        flow = f"flow-type tcp{cfg.addr_ipver} dst-port {port} context {ctx_id}"
+        ntuple = ethtool_create(cfg, "-N", flow)
+
+        cnts = _get_rx_cnts(cfg)
+        GenerateTraffic(cfg, port=port).wait_pkts_and_stop(20000)
+        cnts = _get_rx_cnts(cfg, prev=cnts)
+
+        ksft_lt(sum(cnts[ :2]),  7000, "traffic on main context: " + str(cnts))
+        ksft_ge(sum(cnts[2:4]), 20000, "traffic on extra context: " + str(cnts))
+        if other_ctx == 0:
+            ksft_eq(sum(cnts[4: ]),     0, "traffic on other queues: " + str(cnts))
+    finally:
+        if ntuple is not None:
+            ethtool(f"-N {cfg.ifname} delete {ntuple}")
+        if ctx_id:
+            ethtool(f"-X {cfg.ifname} context {ctx_id} delete")
+        if other_ctx == 0:
+            ethtool(f"-X {cfg.ifname} default")
+        else:
+            ethtool(f"-X {cfg.ifname} context {other_ctx} delete")
+        if queue_cnt:
+            ethtool(f"-L {cfg.ifname} combined {queue_cnt}")
+
+
+def test_rss_context_overlap2(cfg):
+    test_rss_context_overlap(cfg, True)
+
+
+def main() -> None:
+    with NetDrvEpEnv(__file__, nsim_test=False) as cfg:
+        cfg.netdevnl = NetdevFamily()
+
+        ksft_run([test_rss_key_indir,
+                  test_rss_context, test_rss_context4, test_rss_context32,
+                  test_rss_context_overlap, test_rss_context_overlap2,
+                  test_rss_context_out_of_order, test_rss_context4_create_with_cfg],
+                 args=(cfg, ))
+    ksft_exit()
+
+
+if __name__ == "__main__":
+    main()

tools/testing/selftests/drivers/net/lib/py/load.py

···
 from lib.py import ksft_pr, cmd, ip, rand_port, wait_port_listen
 
 class GenerateTraffic:
-    def __init__(self, env):
+    def __init__(self, env, port=None):
         env.require_cmd("iperf3", remote=True)
 
         self.env = env
 
-        port = rand_port()
-        self._iperf_server = cmd(f"iperf3 -s -p {port}", background=True)
+        if port is None:
+            port = rand_port()
+        self._iperf_server = cmd(f"iperf3 -s -1 -p {port}", background=True)
         wait_port_listen(port)
         time.sleep(0.1)
         self._iperf_client = cmd(f"iperf3 -c {env.addr} -P 16 -p {port} -t 86400",

tools/testing/selftests/net/lib/py/ksft.py

···
         _fail("Check failed", a, "<", b, comment)
 
 
+def ksft_lt(a, b, comment=""):
+    if a >= b:
+        _fail("Check failed", a, ">=", b, comment)
+
+
 class ksft_raises:
     def __init__(self, expected_type):
         self.exception = None

tools/testing/selftests/net/lib/py/utils.py

···
 import time
 
 
+class CmdExitFailure(Exception):
+    pass
+
+
 class cmd:
     def __init__(self, comm, shell=True, fail=True, ns=None, background=False, host=None, timeout=5):
         if ns:
···
         if self.proc.returncode != 0 and fail:
             if len(stderr) > 0 and stderr[-1] == "\n":
                 stderr = stderr[:-1]
-            raise Exception("Command failed: %s\nSTDOUT: %s\nSTDERR: %s" %
-                            (self.proc.args, stdout, stderr))
+            raise CmdExitFailure("Command failed: %s\nSTDOUT: %s\nSTDERR: %s" %
+                                 (self.proc.args, stdout, stderr))
 
 
 class bkg(cmd):