selftests: drv-net: test random value for hds-thresh

JIRA: https://issues.redhat.com/browse/RHEL-75603

Conflicts:
 A conflict occurred due to code differences caused by a missing
 unrelated commit. I resolved the conflict by aligning the code to match
 the intended changes in this patch.

commit 22d3a63
Author: Taehee Yoo <ap420073@gmail.com>
Date:   Fri Apr 4 12:21:26 2025 +0000

    selftests: drv-net: test random value for hds-thresh

    hds.py has been testing 0(set_hds_thresh_zero()),
    MAX(set_hds_thresh_max()), GT(set_hds_thresh_gt()) values for hds-thresh.
    However if a hds-thresh value was already 0, set_hds_thresh_zero()
    can't test properly.
    So, it tests random value first and then tests 0, MAX, GT values.

    Testing bnxt:
        TAP version 13
        1..13
        ok 1 hds.get_hds
        ok 2 hds.get_hds_thresh
        ok 3 hds.set_hds_disable # SKIP disabling of HDS not supported by
        the device
        ok 4 hds.set_hds_enable
        ok 5 hds.set_hds_thresh_random
        ok 6 hds.set_hds_thresh_zero
        ok 7 hds.set_hds_thresh_max
        ok 8 hds.set_hds_thresh_gt
        ok 9 hds.set_xdp
        ok 10 hds.enabled_set_xdp
        ok 11 hds.ioctl
        ok 12 hds.ioctl_set_xdp
        ok 13 hds.ioctl_enabled_set_xdp
        # Totals: pass:12 fail:0 xfail:0 xpass:0 skip:1 error:0

    Testing lo:
        TAP version 13
        1..13
        ok 1 hds.get_hds # SKIP tcp-data-split not supported by device
        ok 2 hds.get_hds_thresh # SKIP hds-thresh not supported by device
        ok 3 hds.set_hds_disable # SKIP ring-set not supported by the device
        ok 4 hds.set_hds_enable # SKIP ring-set not supported by the device
        ok 5 hds.set_hds_thresh_random # SKIP hds-thresh not supported by
        device
        ok 6 hds.set_hds_thresh_zero # SKIP ring-set not supported by the
        device
        ok 7 hds.set_hds_thresh_max # SKIP hds-thresh not supported by
        device
        ok 8 hds.set_hds_thresh_gt # SKIP hds-thresh not supported by device
        ok 9 hds.set_xdp # SKIP tcp-data-split not supported by device
        ok 10 hds.enabled_set_xdp # SKIP tcp-data-split not supported by
        device
        ok 11 hds.ioctl # SKIP tcp-data-split not supported by device
        ok 12 hds.ioctl_set_xdp # SKIP tcp-data-split not supported by
        device
        ok 13 hds.ioctl_enabled_set_xdp # SKIP tcp-data-split not supported
        by device
        # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:13 error:0

    Signed-off-by: Taehee Yoo <ap420073@gmail.com>
    Link: https://patch.msgid.link/20250404122126.1555648-3-ap420073@gmail.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Mohammad Heib <mheib@redhat.com>

Author: mohammadheib

tools/testing/selftests/drivers/net/hds.py

@@ -5,6 +5,7 @@
 from lib.py import ksft_run, ksft_exit, ksft_eq, ksft_raises, KsftSkipEx
 from lib.py import EthtoolFamily, NlError
 from lib.py import NetDrvEnv
+from lib.py import defer, ethtool, ip, random
 
 def get_hds(cfg, netnl) -> None:
     try:
@@ -73,6 +74,36 @@ def set_hds_thresh_zero(cfg, netnl) -> None:
 
     ksft_eq(0, rings['hds-thresh'])
 
+def set_hds_thresh_random(cfg, netnl) -> None:
+    try:
+        rings = netnl.rings_get({'header': {'dev-index': cfg.ifindex}})
+    except NlError as e:
+        raise KsftSkipEx('ring-get not supported by device')
+    if 'hds-thresh' not in rings:
+        raise KsftSkipEx('hds-thresh not supported by device')
+    if 'hds-thresh-max' not in rings:
+        raise KsftSkipEx('hds-thresh-max not defined by device')
+
+    if rings['hds-thresh-max'] < 2:
+        raise KsftSkipEx('hds-thresh-max is too small')
+    elif rings['hds-thresh-max'] == 2:
+        hds_thresh = 1
+    else:
+        while True:
+            hds_thresh = random.randint(1, rings['hds-thresh-max'] - 1)
+            if hds_thresh != rings['hds-thresh']:
+                break
+
+    try:
+        netnl.rings_set({'header': {'dev-index': cfg.ifindex}, 'hds-thresh': hds_thresh})
+    except NlError as e:
+        if e.error == errno.EINVAL:
+            raise KsftSkipEx("hds-thresh-set not supported by the device")
+        elif e.error == errno.EOPNOTSUPP:
+            raise KsftSkipEx("ring-set not supported by the device")
+    rings = netnl.rings_get({'header': {'dev-index': cfg.ifindex}})
+    ksft_eq(hds_thresh, rings['hds-thresh'])
+
 def set_hds_thresh_max(cfg, netnl) -> None:
     try:
         rings = netnl.rings_get({'header': {'dev-index': cfg.ifindex}})
@@ -110,6 +141,7 @@ def main() -> None:
                   get_hds_thresh,
                   set_hds_disable,
                   set_hds_enable,
+                  set_hds_thresh_random,
                   set_hds_thresh_zero,
                   set_hds_thresh_max,
                   set_hds_thresh_gt],