[PATCH net-next 6/7] selftests: drv-net: extend so_txtime with hw offload

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

From: Willem de Bruijn <willemb@google.com>

Add two pacing hardware offload variants

1. one that uses FQ to safely offload when within bounds.
2. one that uses pfifo_fast and thus forwards all packets.

Verify that the packets are paced in hardware with new flag '-h'.

Also move the ip version check to the main test_so_txtime callee,
rather than having to add checks to the new variants.

Also increase test timeout to 2 min. This suite now counts 58 tests,
which each take 2 sec to stabilize when run with KSFT_MACHINE_SLOW.
When increasing the bound, do so with a sizable headroom.

Also increase rcvtimeout significantly to reduce flakiness.

Signed-off-by: Willem de Bruijn <willemb@google.com>
---
 tools/testing/selftests/drivers/net/settings  |  1 +
 .../testing/selftests/drivers/net/so_txtime.c |  2 +-
 .../selftests/drivers/net/so_txtime.py        | 72 +++++++++++++++++--
 3 files changed, 70 insertions(+), 5 deletions(-)
 create mode 100644 tools/testing/selftests/drivers/net/settings

diff --git a/tools/testing/selftests/drivers/net/settings b/tools/testing/selftests/drivers/net/settings
new file mode 100644
index 000000000000..b478e684846a
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/settings
@@ -0,0 +1 @@
+timeout=240
diff --git a/tools/testing/selftests/drivers/net/so_txtime.c b/tools/testing/selftests/drivers/net/so_txtime.c
index 5900ca97957c..6e64baa4c60d 100644
--- a/tools/testing/selftests/drivers/net/so_txtime.c
+++ b/tools/testing/selftests/drivers/net/so_txtime.c
@@ -375,7 +375,7 @@ static int setup_tx(struct sockaddr *addr, socklen_t alen)
 
 static int setup_rx(struct sockaddr *addr, socklen_t alen)
 {
-	struct timeval tv = { .tv_usec = 100 * 1000 };
+	struct timeval tv = { .tv_usec = 600 * 1000 };
 	int fd;
 
 	fd = socket(addr->sa_family, SOCK_DGRAM, 0);
diff --git a/tools/testing/selftests/drivers/net/so_txtime.py b/tools/testing/selftests/drivers/net/so_txtime.py
index adf6c848d6d8..9dbf6067de27 100755
--- a/tools/testing/selftests/drivers/net/so_txtime.py
+++ b/tools/testing/selftests/drivers/net/so_txtime.py
@@ -12,10 +12,13 @@ import time
 from lib.py import ksft_exit, ksft_run, ksft_variants
 from lib.py import KsftNamedVariant, KsftSkipEx
 from lib.py import NetDrvEpEnv, bkg, cmd, defer, tc
+from lib.py import EthtoolFamily, NlError
 
 
 def test_so_txtime(cfg, clockid, ipver, args_tx, args_rx, expect_success):
     """Main function. Run so_txtime as sender and receiver."""
+    cfg.require_ipver(ipver)
+
     slow_machine = os.environ.get('KSFT_MACHINE_SLOW')
 
     if not hasattr(cfg, "bin_remote"):
@@ -38,6 +41,34 @@ def test_so_txtime(cfg, clockid, ipver, args_tx, args_rx, expect_success):
         cmd(cmd_tx)
 
 
+def _dev_setup_pacing_offload(cfg):
+    """Configure pacing-offload-horizon."""
+    ethnl = EthtoolFamily()
+
+    try:
+        rings = ethnl.rings_get({'header': {'dev-index': cfg.ifindex}})
+    except NlError:
+        raise KsftSkipEx('ring-get not supported by device')
+
+    if 'pacing-offload-horizon' not in rings or \
+       'pacing-offload-horizon-max' not in rings:
+        raise KsftSkipEx('pacing offload horizon not supported by device')
+
+    if rings['pacing-offload-horizon-max'] < 50_000:
+        raise KsftSkipEx('pacing offload max horizon too small')
+
+    cur_horizon = rings['pacing-offload-horizon']
+    new_horizon = 50_000
+    ethnl.rings_set({
+        'header': {'dev-index': cfg.ifindex},
+        'pacing-offload-horizon': new_horizon,
+    })
+    defer(ethnl.rings_set, {
+        'header': {'dev-index': cfg.ifindex},
+        'pacing-offload-horizon': cur_horizon
+    })
+
+
 def _qdisc_setup(ifname, qdisc, optargs=""):
     """Replace root qdisc. Restore the original after the test.
 
@@ -56,6 +87,7 @@ def _test_variants_fq():
             ["one_pkt", "a,10", "a,10"],
             ["in_order", "a,10,b,20", "a,10,b,20"],
             ["reverse_order", "a,20,b,10", "b,10,a,20"],
+            ["beyond_hw_horizon", "a,70", "a,70"],
         ]:
             name = f"v{ipver}_{testcase[0]}"
             yield KsftNamedVariant(name, ipver, testcase[1], testcase[2])
@@ -64,15 +96,42 @@ def _test_variants_fq():
 @ksft_variants(_test_variants_fq())
 def test_so_txtime_fq_mono(cfg, ipver, args_tx, args_rx):
     """Run all variants of monotonic (fq) tests."""
-    cfg.require_ipver(ipver)
     _qdisc_setup(cfg.ifname, "fq")
     test_so_txtime(cfg, "mono", ipver, args_tx, args_rx, True)
 
 
+@ksft_variants(_test_variants_fq())
+def test_so_txtime_fq_mono_hw(cfg, ipver, args_tx, args_rx):
+    """Run all variants of monotonic fq tests, with offload horizon."""
+    cfg.require_nsim(nsim_test=False)
+
+    _dev_setup_pacing_offload(cfg)
+    try:
+        _qdisc_setup(cfg.ifname, "fq", "offload_horizon 50ms")
+    except Exception as e:
+        raise KsftSkipEx("netdev does not support offload. skipping") from e
+
+    # Expect all tests to use only hw pacing, except beyond_hw_horizon.
+    hw_only = "-h" if args_tx != "a,70" else ""
+    test_so_txtime(cfg, "mono", ipver, f"{hw_only} {args_tx}", args_rx, True)
+
+
+@ksft_variants(_test_variants_fq())
+def test_so_txtime_pfifofast_mono_hw(cfg, ipver, args_tx, args_rx):
+    """Run all variants of monotonic tests, without fq pacing sw backup."""
+    cfg.require_nsim(nsim_test=False)
+
+    _dev_setup_pacing_offload(cfg)
+    _qdisc_setup(cfg.ifname, "pfifo_fast")
+
+    # Expect all tests to pass, except beyond_hw_horizon without sw fallback.
+    expect_pass = False if args_tx == "a,70" else True
+    test_so_txtime(cfg, "mono", ipver, f"-h {args_tx}", args_rx, expect_pass)
+
+
 @ksft_variants(_test_variants_fq())
 def test_so_txtime_fq_tai(cfg, ipver, args_tx, args_rx):
     """Run all variants of fq tests, but pass CLOCK_TAI to test conversion."""
-    cfg.require_ipver(ipver)
     _qdisc_setup(cfg.ifname, "fq")
     test_so_txtime(cfg, "tai", ipver, args_tx, args_rx, True)
 
@@ -95,7 +154,6 @@ def _test_variants_etf():
 @ksft_variants(_test_variants_etf())
 def test_so_txtime_etf(cfg, ipver, args_tx, args_rx, expect_fail):
     """Run all variants of etf tests."""
-    cfg.require_ipver(ipver)
     try:
         _qdisc_setup(cfg.ifname, "etf", "clockid CLOCK_TAI delta 400000")
     except Exception as e:
@@ -108,7 +166,13 @@ def main() -> None:
     """Boilerplate ksft main."""
     with NetDrvEpEnv(__file__) as cfg:
         ksft_run(
-            [test_so_txtime_fq_mono, test_so_txtime_fq_tai, test_so_txtime_etf],
+            [
+                test_so_txtime_fq_mono,
+                test_so_txtime_fq_mono_hw,
+                test_so_txtime_pfifofast_mono_hw,
+                test_so_txtime_fq_tai,
+                test_so_txtime_etf,
+            ],
             args=(cfg,),
         )
     ksft_exit()
-- 
2.55.0.795.g602f6c329a-goog