Merge branch 'net-ethtool-rss-add-notifications'

Jakub Kicinski says:

====================
net: ethtool: rss: add notifications

Next step on the path to moving RSS config to Netlink. With the
refactoring of the driver-facing API for ETHTOOL_GRXFH/ETHTOOL_SRXFH
out of the way we can move on to more interesting work.

Add Netlink notifications for changes in RSS configuration.

As a reminder (part) of rss-get was introduced in previous releases
when input-xfrm (symmetric hashing) was added. rss-set isn't
implemented, yet, but we can implement rss-ntf and hook it into
the changes done via the IOCTL path (same as other ethtool-nl
notifications do).

Most of the series is concerned with passing arguments to notifications.
So far none of the notifications needed to be parametrized, but RSS can
have multiple contexts per device, and since GET operates on a single
context at a time, the notification needs to also be scoped to a context.
Patches 2-5 add support for passing arguments to notifications thru
ethtool-nl generic infra.

The notification handling itself is pretty trivial, it's mostly
hooking in the right entries into the ethool-nl op tables.

v1: https://lore.kernel.org/20250621171944.2619249-1-kuba@kernel.org
====================

Link: https://patch.msgid.link/20250623231720.3124717-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 71 insertions, 27 deletions

diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index b4683d286a5a..c41db1595621 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -74,4 +74,12 @@ int ethtool_get_module_eeprom_call(struct net_device *dev,
 
 bool __ethtool_dev_mm_supported(struct net_device *dev);
 
+#if IS_ENABLED(CONFIG_ETHTOOL_NETLINK)
+void ethtool_rss_notify(struct net_device *dev, u32 rss_context);
+#else
+static inline void ethtool_rss_notify(struct net_device *dev, u32 rss_context)
+{
+}
+#endif
+
 #endif /* _ETHTOOL_COMMON_H */
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 82cde640aa87..c34bac7bffd8 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -617,8 +617,8 @@ static int ethtool_set_link_ksettings(struct net_device *dev,
 
 	err = dev->ethtool_ops->set_link_ksettings(dev, &link_ksettings);
 	if (err >= 0) {
-		ethtool_notify(dev, ETHTOOL_MSG_LINKINFO_NTF, NULL);
-		ethtool_notify(dev, ETHTOOL_MSG_LINKMODES_NTF, NULL);
+		ethtool_notify(dev, ETHTOOL_MSG_LINKINFO_NTF);
+		ethtool_notify(dev, ETHTOOL_MSG_LINKMODES_NTF);
 	}
 	return err;
 }
@@ -708,8 +708,8 @@ static int ethtool_set_settings(struct net_device *dev, void __user *useraddr)
 		__ETHTOOL_LINK_MODE_MASK_NU32;
 	ret = dev->ethtool_ops->set_link_ksettings(dev, &link_ksettings);
 	if (ret >= 0) {
-		ethtool_notify(dev, ETHTOOL_MSG_LINKINFO_NTF, NULL);
-		ethtool_notify(dev, ETHTOOL_MSG_LINKMODES_NTF, NULL);
+		ethtool_notify(dev, ETHTOOL_MSG_LINKINFO_NTF);
+		ethtool_notify(dev, ETHTOOL_MSG_LINKMODES_NTF);
 	}
 	return ret;
 }
@@ -1502,6 +1502,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	struct ethtool_rxfh rxfh;
 	bool locked = false; /* dev->ethtool->rss_lock taken */
 	bool create = false;
+	bool mod = false;
 	u8 *rss_config;
 	int ret;
 
@@ -1688,6 +1689,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		}
 		goto out;
 	}
+	mod = !create && !rxfh_dev.rss_delete;
 
 	if (copy_to_user(useraddr + offsetof(struct ethtool_rxfh, rss_context),
 			 &rxfh_dev.rss_context, sizeof(rxfh_dev.rss_context)))
@@ -1757,6 +1759,8 @@ out:
 	if (locked)
 		mutex_unlock(&dev->ethtool->rss_lock);
 	kfree(rss_config);
+	if (mod)
+		ethtool_rss_notify(dev, rxfh.rss_context);
 	return ret;
 }
 
@@ -1868,7 +1872,7 @@ static int ethtool_set_wol(struct net_device *dev, char __user *useraddr)
 		return ret;
 
 	dev->ethtool->wol_enabled = !!wol.wolopts;
-	ethtool_notify(dev, ETHTOOL_MSG_WOL_NTF, NULL);
+	ethtool_notify(dev, ETHTOOL_MSG_WOL_NTF);
 
 	return 0;
 }
@@ -1944,7 +1948,7 @@ static int ethtool_set_eee(struct net_device *dev, char __user *useraddr)
 	eee_to_keee(&keee, &eee);
 	ret = dev->ethtool_ops->set_eee(dev, &keee);
 	if (!ret)
-		ethtool_notify(dev, ETHTOOL_MSG_EEE_NTF, NULL);
+		ethtool_notify(dev, ETHTOOL_MSG_EEE_NTF);
 	return ret;
 }
 
@@ -2184,7 +2188,7 @@ static noinline_for_stack int ethtool_set_coalesce(struct net_device *dev,
 	ret = dev->ethtool_ops->set_coalesce(dev, &coalesce, &kernel_coalesce,
 					     NULL);
 	if (!ret)
-		ethtool_notify(dev, ETHTOOL_MSG_COALESCE_NTF, NULL);
+		ethtool_notify(dev, ETHTOOL_MSG_COALESCE_NTF);
 	return ret;
 }
 
@@ -2228,7 +2232,7 @@ static int ethtool_set_ringparam(struct net_device *dev, void __user *useraddr)
 	ret = dev->ethtool_ops->set_ringparam(dev, &ringparam,
 					      &kernel_ringparam, NULL);
 	if (!ret)
-		ethtool_notify(dev, ETHTOOL_MSG_RINGS_NTF, NULL);
+		ethtool_notify(dev, ETHTOOL_MSG_RINGS_NTF);
 	return ret;
 }
 
@@ -2295,7 +2299,7 @@ static noinline_for_stack int ethtool_set_channels(struct net_device *dev,
 
 	ret = dev->ethtool_ops->set_channels(dev, &channels);
 	if (!ret)
-		ethtool_notify(dev, ETHTOOL_MSG_CHANNELS_NTF, NULL);
+		ethtool_notify(dev, ETHTOOL_MSG_CHANNELS_NTF);
 	return ret;
 }
 
@@ -2326,7 +2330,7 @@ static int ethtool_set_pauseparam(struct net_device *dev, void __user *useraddr)
 
 	ret = dev->ethtool_ops->set_pauseparam(dev, &pauseparam);
 	if (!ret)
-		ethtool_notify(dev, ETHTOOL_MSG_PAUSE_NTF, NULL);
+		ethtool_notify(dev, ETHTOOL_MSG_PAUSE_NTF);
 	return ret;
 }
 
@@ -3328,7 +3332,7 @@ __dev_ethtool(struct net *net, struct ifreq *ifr, void __user *useraddr,
 		rc = ethtool_set_value_void(dev, useraddr,
 				       dev->ethtool_ops->set_msglevel);
 		if (!rc)
-			ethtool_notify(dev, ETHTOOL_MSG_DEBUG_NTF, NULL);
+			ethtool_notify(dev, ETHTOOL_MSG_DEBUG_NTF);
 		break;
 	case ETHTOOL_GEEE:
 		rc = ethtool_get_eee(dev, useraddr);
@@ -3392,7 +3396,7 @@ __dev_ethtool(struct net *net, struct ifreq *ifr, void __user *useraddr,
 		rc = ethtool_get_value(dev, useraddr, ethcmd,
 				       dev->ethtool_ops->get_priv_flags);
 		if (!rc)
-			ethtool_notify(dev, ETHTOOL_MSG_PRIVFLAGS_NTF, NULL);
+			ethtool_notify(dev, ETHTOOL_MSG_PRIVFLAGS_NTF);
 		break;
 	case ETHTOOL_SPFLAGS:
 		rc = ethtool_set_value(dev, useraddr,
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 9de828df46cd..09c81cc9a08f 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -863,8 +863,8 @@ static int ethnl_default_done(struct netlink_callback *cb)
 static int ethnl_default_set_doit(struct sk_buff *skb, struct genl_info *info)
 {
 	const struct ethnl_request_ops *ops;
-	struct ethnl_req_info req_info = {};
 	const u8 cmd = info->genlhdr->cmd;
+	struct ethnl_req_info *req_info;
 	struct net_device *dev;
 	int ret;
 
@@ -874,20 +874,22 @@ static int ethnl_default_set_doit(struct sk_buff *skb, struct genl_info *info)
 	if (GENL_REQ_ATTR_CHECK(info, ops->hdr_attr))
 		return -EINVAL;
 
-	ret = ethnl_parse_header_dev_get(&req_info, info->attrs[ops->hdr_attr],
-					 genl_info_net(info), info->extack,
-					 true);
+	req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
+	if (!req_info)
+		return -ENOMEM;
+
+	ret = ethnl_default_parse(req_info, info,  ops, true);
 	if (ret < 0)
-		return ret;
+		goto out_free_req;
 
 	if (ops->set_validate) {
-		ret = ops->set_validate(&req_info, info);
+		ret = ops->set_validate(req_info, info);
 		/* 0 means nothing to do */
 		if (ret <= 0)
 			goto out_dev;
 	}
 
-	dev = req_info.dev;
+	dev = req_info->dev;
 
 	rtnl_lock();
 	netdev_lock_ops(dev);
@@ -902,14 +904,14 @@ static int ethnl_default_set_doit(struct sk_buff *skb, struct genl_info *info)
 	if (ret < 0)
 		goto out_free_cfg;
 
-	ret = ops->set(&req_info, info);
+	ret = ops->set(req_info, info);
 	if (ret < 0)
 		goto out_ops;
 
 	swap(dev->cfg, dev->cfg_pending);
 	if (!ret)
 		goto out_ops;
-	ethtool_notify(dev, ops->set_ntf_cmd, NULL);
+	ethnl_notify(dev, ops->set_ntf_cmd, req_info);
 
 	ret = 0;
 out_ops:
@@ -921,7 +923,9 @@ out_tie_cfg:
 	netdev_unlock_ops(dev);
 	rtnl_unlock();
 out_dev:
-	ethnl_parse_header_dev_put(&req_info);
+	ethnl_parse_header_dev_put(req_info);
+out_free_req:
+	kfree(req_info);
 	return ret;
 }
 
@@ -942,11 +946,12 @@ ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = {
 	[ETHTOOL_MSG_MODULE_NTF]	= &ethnl_module_request_ops,
 	[ETHTOOL_MSG_PLCA_NTF]		= &ethnl_plca_cfg_request_ops,
 	[ETHTOOL_MSG_MM_NTF]		= &ethnl_mm_request_ops,
+	[ETHTOOL_MSG_RSS_NTF]		= &ethnl_rss_request_ops,
 };
 
 /* default notification handler */
 static void ethnl_default_notify(struct net_device *dev, unsigned int cmd,
-				 const void *data)
+				 const struct ethnl_req_info *orig_req_info)
 {
 	struct ethnl_reply_data *reply_data;
 	const struct ethnl_request_ops *ops;
@@ -975,6 +980,11 @@ static void ethnl_default_notify(struct net_device *dev, unsigned int cmd,
 
 	req_info->dev = dev;
 	req_info->flags |= ETHTOOL_FLAG_COMPACT_BITSETS;
+	if (orig_req_info) {
+		req_info->phy_index = orig_req_info->phy_index;
+		memcpy(&req_info[1], &orig_req_info[1],
+		       ops->req_info_size - sizeof(*req_info));
+	}
 
 	netdev_ops_assert_locked(dev);
 
@@ -1025,7 +1035,7 @@ err_rep:
 /* notifications */
 
 typedef void (*ethnl_notify_handler_t)(struct net_device *dev, unsigned int cmd,
-				       const void *data);
+				       const struct ethnl_req_info *req_info);
 
 static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
 	[ETHTOOL_MSG_LINKINFO_NTF]	= ethnl_default_notify,
@@ -1043,9 +1053,11 @@ static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
 	[ETHTOOL_MSG_MODULE_NTF]	= ethnl_default_notify,
 	[ETHTOOL_MSG_PLCA_NTF]		= ethnl_default_notify,
 	[ETHTOOL_MSG_MM_NTF]		= ethnl_default_notify,
+	[ETHTOOL_MSG_RSS_NTF]		= ethnl_default_notify,
 };
 
-void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
+void ethnl_notify(struct net_device *dev, unsigned int cmd,
+		  const struct ethnl_req_info *req_info)
 {
 	if (unlikely(!ethnl_ok))
 		return;
@@ -1053,18 +1065,23 @@ void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
 
 	if (likely(cmd < ARRAY_SIZE(ethnl_notify_handlers) &&
 		   ethnl_notify_handlers[cmd]))
-		ethnl_notify_handlers[cmd](dev, cmd, data);
+		ethnl_notify_handlers[cmd](dev, cmd, req_info);
 	else
 		WARN_ONCE(1, "notification %u not implemented (dev=%s)\n",
 			  cmd, netdev_name(dev));
 }
+
+void ethtool_notify(struct net_device *dev, unsigned int cmd)
+{
+	ethnl_notify(dev, cmd, NULL);
+}
 EXPORT_SYMBOL(ethtool_notify);
 
 static void ethnl_notify_features(struct netdev_notifier_info *info)
 {
 	struct net_device *dev = netdev_notifier_info_to_dev(info);
 
-	ethtool_notify(dev, ETHTOOL_MSG_FEATURES_NTF, NULL);
+	ethtool_notify(dev, ETHTOOL_MSG_FEATURES_NTF);
 }
 
 static int ethnl_netdev_event(struct notifier_block *this, unsigned long event,
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 91b953924af3..373a8d5e86ae 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -23,6 +23,8 @@ void *ethnl_dump_put(struct sk_buff *skb, struct netlink_callback *cb, u8 cmd);
 void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd);
 void *ethnl_unicast_put(struct sk_buff *skb, u32 portid, u32 seq, u8 cmd);
 int ethnl_multicast(struct sk_buff *skb, struct net_device *dev);
+void ethnl_notify(struct net_device *dev, unsigned int cmd,
+		  const struct ethnl_req_info *req_info);
 
 /**
  * ethnl_strz_size() - calculate attribute length for fixed size string
@@ -337,6 +339,8 @@ int ethnl_sock_priv_set(struct sk_buff *skb, struct net_device *dev, u32 portid,
  *	header is already filled on entry, the rest up to @repdata_offset
  *	is zero initialized. This callback should only modify type specific
  *	request info by parsed attributes from request message.
+ *	Called for both GET and SET. Information parsed for SET will
+ *	be conveyed to the req_info used during NTF generation.
  * @prepare_data:
  *	Retrieve and prepare data needed to compose a reply message. Calls to
  *	ethtool_ops handlers are limited to this callback. Common reply data
diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index 6d9b1769896b..3adddca7e215 100644
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -358,6 +358,17 @@ int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 	return ret;
 }
 
+/* RSS_NTF */
+
+void ethtool_rss_notify(struct net_device *dev, u32 rss_context)
+{
+	struct rss_req_info req_info = {
+		.rss_context = rss_context,
+	};
+
+	ethnl_notify(dev, ETHTOOL_MSG_RSS_NTF, &req_info.base);
+}
+
 const struct ethnl_request_ops ethnl_rss_request_ops = {
 	.request_cmd		= ETHTOOL_MSG_RSS_GET,
 	.reply_cmd		= ETHTOOL_MSG_RSS_GET_REPLY,