The requirement of ->get_rxfh_fields() in ethtool_set_rxfh() is there to verify that we have no conflict of input_xfrm with the RSS fields options, there is no point in doing it if input_xfrm is not supported/requested. This is under the assumption that a driver that supports input_xfrm will also support ->get_rxfh_fields(), so add a WARN_ON() to ethtool_check_ops() to verify it, and remove the op NULL check. This fixes the following error in mlx4_en, which doesn't support getting/setting RXFH fields. $ ethtool --set-rxfh-indir eth2 hfunc xor Cannot set RX flow hash configuration: Operation not supported Fixes: 72792461c8e8 ("net: ethtool: don't mux RXFH via rxnfc callbacks") Reviewed-by: Dragos Tatulea Signed-off-by: Gal Pressman --- Changelog - v1->v2: https://lore.kernel.org/all/20250709153251.360291-1-gal@nvidia.com/ * Assume that input_xfrm support must be accompanied by ->get_rxfh_fields() and remove the op NULL check completely. --- net/ethtool/common.c | 2 ++ net/ethtool/ioctl.c | 5 ++++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/net/ethtool/common.c b/net/ethtool/common.c index d62dc56f2f5b..459cf25e763e 100644 --- a/net/ethtool/common.c +++ b/net/ethtool/common.c @@ -812,6 +812,8 @@ int ethtool_check_ops(const struct ethtool_ops *ops) return -EINVAL; if (WARN_ON(ops->rxfh_max_num_contexts == 1)) return -EINVAL; + if (WARN_ON(ops->supported_input_xfrm && !ops->get_rxfh_fields)) + return -EINVAL; /* NOTE: sufficiently insane drivers may swap ethtool_ops at runtime, * the fact that ops are checked at registration time does not * mean the ops attached to a netdev later on are sane. diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index cccb4694f5e1..830623678cb3 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -1041,6 +1041,9 @@ static int ethtool_check_flow_types(struct net_device *dev, u32 input_xfrm) int err; u32 i; + if (!input_xfrm || input_xfrm == RXH_XFRM_NO_CHANGE) + return 0; + for (i = 0; i < __FLOW_TYPE_COUNT; i++) { struct ethtool_rxfh_fields fields = { .flow_type = i, @@ -1523,7 +1526,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev, u8 *rss_config; int ret; - if (!ops->get_rxnfc || !ops->get_rxfh_fields || !ops->set_rxfh) + if (!ops->get_rxnfc || !ops->set_rxfh) return -EOPNOTSUPP; if (ops->get_rxfh_indir_size) -- 2.40.1