A hds-thresh value is not set correctly if input value is 0. The cause is that ethtool_ringparam_get_cfg(), which is a internal function that returns ringparameters from both ->get_ringparam() and dev->cfg can't return a correct hds-thresh value.
The first patch fixes ethtool_ringparam_get_cfg() to set hds-thresh value correcltly.
The second patch adds random test for hds-thresh value. So that we can test 0 value for a hds-thresh properly.
v2: - Skips set_hds_thresh_random test when hds-thresh-max value is too small. (2/2) - Change random range from 1-MAX to 1-(MAX-1). (2/2)
Taehee Yoo (2): net: ethtool: fix ethtool_ringparam_get_cfg() returns a hds_thresh value always as 0. selftests: drv-net: test random value for hds-thresh
net/ethtool/common.c | 1 + tools/testing/selftests/drivers/net/hds.py | 33 +++++++++++++++++++++- 2 files changed, 33 insertions(+), 1 deletion(-)
When hds-thresh is configured, ethnl_set_rings() is called, and it calls ethtool_ringparam_get_cfg() to get ringparameters from .get_ringparam() callback and dev->cfg. Both hds_config and hds_thresh values should be set from dev->cfg, not from .get_ringparam(). But ethtool_ringparam_get_cfg() sets only hds_config from dev->cfg. So, ethtool_ringparam_get_cfg() returns always a hds_thresh as 0.
If an input value of hds-thresh is 0, a hds_thresh value from ethtool_ringparam_get_cfg() are same. So ethnl_set_rings() does nothing and returns immediately. It causes a bug that setting a hds-thresh value to 0 is not working.
Reproducer: modprobe netdevsim echo 1 > /sys/bus/netdevsim/new_device ethtool -G eth0 hds-thresh 100 ethtool -G eth0 hds-thresh 0 ethtool -g eth0 #hds-thresh value should be 0, but it shows 100.
The tools/testing/selftests/drivers/net/hds.py can test it too with applying a following patch for hds.py.
Fixes: 928459bbda19 ("net: ethtool: populate the default HDS params in the core") Signed-off-by: Taehee Yoo ap420073@gmail.com ---
The ethtool command doesn't support hds-thresh option yet. So, RFC[1] patch is needed to be applied.
v2: - No changes.
net/ethtool/common.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/ethtool/common.c b/net/ethtool/common.c index 0cb6da1f692a..49bea6b45bd5 100644 --- a/net/ethtool/common.c +++ b/net/ethtool/common.c @@ -830,6 +830,7 @@ void ethtool_ringparam_get_cfg(struct net_device *dev,
/* Driver gives us current state, we want to return current config */ kparam->tcp_data_split = dev->cfg->hds_config; + kparam->hds_thresh = dev->cfg->hds_thresh; }
static void ethtool_init_tsinfo(struct kernel_ethtool_ts_info *info)
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 ---
v2: - Skips set_hds_thresh_random test when hds-thresh-max value is too small. - Change random range from 1-MAX to 1-(MAX-1).
tools/testing/selftests/drivers/net/hds.py | 33 +++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/drivers/net/hds.py b/tools/testing/selftests/drivers/net/hds.py index 8b7f6acad15f..7c90a040ce45 100755 --- a/tools/testing/selftests/drivers/net/hds.py +++ b/tools/testing/selftests/drivers/net/hds.py @@ -6,7 +6,7 @@ import os from lib.py import ksft_run, ksft_exit, ksft_eq, ksft_raises, KsftSkipEx from lib.py import CmdExitFailure, EthtoolFamily, NlError from lib.py import NetDrvEnv -from lib.py import defer, ethtool, ip +from lib.py import defer, ethtool, ip, random
def _get_hds_mode(cfg, netnl) -> str: @@ -109,6 +109,36 @@ 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}}) @@ -243,6 +273,7 @@ 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,
Hello:
This series was applied to netdev/net.git (main) by Jakub Kicinski kuba@kernel.org:
On Fri, 4 Apr 2025 12:21:24 +0000 you wrote:
A hds-thresh value is not set correctly if input value is 0. The cause is that ethtool_ringparam_get_cfg(), which is a internal function that returns ringparameters from both ->get_ringparam() and dev->cfg can't return a correct hds-thresh value.
The first patch fixes ethtool_ringparam_get_cfg() to set hds-thresh value correcltly.
[...]
Here is the summary with links: - [v2,net,1/2] net: ethtool: fix ethtool_ringparam_get_cfg() returns a hds_thresh value always as 0. https://git.kernel.org/netdev/net/c/216a61d33c07 - [v2,net,2/2] selftests: drv-net: test random value for hds-thresh https://git.kernel.org/netdev/net/c/22d3a63d5321
You are awesome, thank you!
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Taehee Yoo