[PATCH net-next 0/8] ethtool: rss: support creating and removing contexts via Netlink

[PATCH net-next 0/8] ethtool: rss: support creating and removing contexts via Netlink

[Jakub Kicinski]

This series completes support of RSS configuration via Netlink.
All functionality supported by the IOCTL is now supported by
Netlink. Future series (time allowing) will add:
 - hashing on the flow label, which started this whole thing;
 - pinning the RSS context to a Netlink socket for auto-cleanup.

The first patch is a leftover held back from previous series
to avoid conflicting with Gal's fix.

Next 4 patches refactor existing code to make reusing it for
context creation possible. 2 patches after that add create
and delete commands. Last but not least the test is extended.

Jakub Kicinski (8):
  ethtool: assert that drivers with sym hash are consistent for RSS
    contexts
  ethtool: rejig the RSS notification machinery for more types
  ethtool: rss: factor out allocating memory for response
  ethtool: rss: factor out populating response from context
  ethtool: move ethtool_rxfh_ctx_alloc() to common code
  ethtool: rss: support creating contexts via Netlink
  ethtool: rss: support removing contexts via Netlink
  selftests: drv-net: rss_api: context create and delete tests

 Documentation/netlink/specs/ethtool.yaml      |  41 +-
 Documentation/networking/ethtool-netlink.rst  |  41 ++
 .../uapi/linux/ethtool_netlink_generated.h    |   5 +
 net/ethtool/common.h                          |   8 +-
 net/ethtool/netlink.h                         |   5 +
 net/ethtool/common.c                          |  39 ++
 net/ethtool/ioctl.c                           |  48 +--
 net/ethtool/netlink.c                         |  22 +
 net/ethtool/rss.c                             | 393 ++++++++++++++++--
 .../selftests/drivers/net/hw/rss_api.py       |  73 ++++
 10 files changed, 603 insertions(+), 72 deletions(-)

-- 
2.50.1

[PATCH net-next 1/8] ethtool: assert that drivers with sym hash are consistent for RSS contexts

[Jakub Kicinski]

Supporting per-RSS context configuration of hashing fields but
not the hashing algorithm would complicate the code a lot.
We'd need to cross check the config against all RSS contexts.
None of the drivers need this today, so explicitly prevent
new drivers with such skewed capabilities from registering.
If such driver appears it will need to first adjust the checks
in the core.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 net/ethtool/common.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 4dcb4194f3ce..82afe0f2a7cd 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -829,6 +829,10 @@ int ethtool_check_ops(const struct ethtool_ops *ops)
 		return -EINVAL;
 	if (WARN_ON(ops->supported_input_xfrm && !ops->get_rxfh_fields))
 		return -EINVAL;
+	if (WARN_ON(ops->supported_input_xfrm &&
+		    ops->rxfh_per_ctx_fields != ops->rxfh_per_ctx_key))
+		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.
-- 
2.50.1

[PATCH net-next 2/8] ethtool: rejig the RSS notification machinery for more types

[Jakub Kicinski]

In anticipation for CREATE and DELETE notifications - explicitly
pass the notification type to ethtool_rss_notify(), when calling
from the IOCTL code.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 net/ethtool/common.h |  5 +++--
 net/ethtool/ioctl.c  | 12 +++++++-----
 net/ethtool/rss.c    |  4 ++--
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index b2718afe38b5..c8385a268ced 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -76,9 +76,10 @@ 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);
+void ethtool_rss_notify(struct net_device *dev, u32 type, u32 rss_context);
 #else
-static inline void ethtool_rss_notify(struct net_device *dev, u32 rss_context)
+static inline void
+ethtool_rss_notify(struct net_device *dev, u32 type, u32 rss_context)
 {
 }
 #endif
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 2dfeaaa099fb..beb17f3671a2 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1105,7 +1105,7 @@ ethtool_set_rxfh_fields(struct net_device *dev, u32 cmd, void __user *useraddr)
 	if (rc)
 		return rc;
 
-	ethtool_rss_notify(dev, fields.rss_context);
+	ethtool_rss_notify(dev, ETHTOOL_MSG_RSS_NTF, fields.rss_context);
 	return 0;
 }
 
@@ -1520,8 +1520,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	struct ethtool_rxnfc rx_rings;
 	struct ethtool_rxfh rxfh;
 	bool create = false;
-	bool mod = false;
 	u8 *rss_config;
+	int ntf = 0;
 	int ret;
 
 	if (!ops->get_rxnfc || !ops->set_rxfh)
@@ -1671,6 +1671,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	rxfh_dev.input_xfrm = rxfh.input_xfrm;
 
 	if (!rxfh.rss_context) {
+		ntf = ETHTOOL_MSG_RSS_NTF;
 		ret = ops->set_rxfh(dev, &rxfh_dev, extack);
 	} else if (create) {
 		ret = ops->create_rxfh_context(dev, ctx, &rxfh_dev, extack);
@@ -1682,9 +1683,11 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		ret = ops->remove_rxfh_context(dev, ctx, rxfh.rss_context,
 					       extack);
 	} else {
+		ntf = ETHTOOL_MSG_RSS_NTF;
 		ret = ops->modify_rxfh_context(dev, ctx, &rxfh_dev, extack);
 	}
 	if (ret) {
+		ntf = 0;
 		if (create) {
 			/* failed to create, free our new tracking entry */
 			xa_erase(&dev->ethtool->rss_ctx, rxfh.rss_context);
@@ -1692,7 +1695,6 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		}
 		goto out_unlock;
 	}
-	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)))
@@ -1732,8 +1734,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	mutex_unlock(&dev->ethtool->rss_lock);
 out_free:
 	kfree(rss_config);
-	if (mod)
-		ethtool_rss_notify(dev, rxfh.rss_context);
+	if (ntf)
+		ethtool_rss_notify(dev, ntf, rxfh.rss_context);
 	return ret;
 }
 
diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index bf45ebc22347..3c6a070ef875 100644
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -461,13 +461,13 @@ int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 
 /* RSS_NTF */
 
-void ethtool_rss_notify(struct net_device *dev, u32 rss_context)
+void ethtool_rss_notify(struct net_device *dev, u32 type, u32 rss_context)
 {
 	struct rss_req_info req_info = {
 		.rss_context = rss_context,
 	};
 
-	ethnl_notify(dev, ETHTOOL_MSG_RSS_NTF, &req_info.base);
+	ethnl_notify(dev, type, &req_info.base);
 }
 
 /* RSS_SET */
-- 
2.50.1

[PATCH net-next 3/8] ethtool: rss: factor out allocating memory for response

[Jakub Kicinski]

To ease the code reuse for RSS_CREATE we'll want to prepare
struct rss_reply_data for the new context. Unfortunately
we can't depend on the exiting scaffolding because the context
doesn't exist (ctx=NULL) when we start preparing. Factor out
the portion of the context 0 handling responsible for allocation
of request memory, so that we can call it directly.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 net/ethtool/rss.c | 47 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 17 deletions(-)

diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index 3c6a070ef875..07a9d89e1c6b 100644
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -113,21 +113,11 @@ rss_prepare_flow_hash(const struct rss_req_info *req, struct net_device *dev,
 }
 
 static int
-rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
-		struct rss_reply_data *data, const struct genl_info *info)
+rss_get_data_alloc(struct net_device *dev, struct rss_reply_data *data)
 {
-	struct ethtool_rxfh_param rxfh = {};
-	const struct ethtool_ops *ops;
+	const struct ethtool_ops *ops = dev->ethtool_ops;
 	u32 total_size, indir_bytes;
 	u8 *rss_config;
-	int ret;
-
-	ops = dev->ethtool_ops;
-
-	ret = ethnl_ops_begin(dev);
-	if (ret < 0)
-		return ret;
-	mutex_lock(&dev->ethtool->rss_lock);
 
 	data->indir_size = 0;
 	data->hkey_size = 0;
@@ -139,16 +129,39 @@ rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
 	indir_bytes = data->indir_size * sizeof(u32);
 	total_size = indir_bytes + data->hkey_size;
 	rss_config = kzalloc(total_size, GFP_KERNEL);
-	if (!rss_config) {
-		ret = -ENOMEM;
-		goto out_unlock;
-	}
+	if (!rss_config)
+		return -ENOMEM;
 
 	if (data->indir_size)
 		data->indir_table = (u32 *)rss_config;
 	if (data->hkey_size)
 		data->hkey = rss_config + indir_bytes;
 
+	return 0;
+}
+
+static void rss_get_data_free(const struct rss_reply_data *data)
+{
+	kfree(data->indir_table);
+}
+
+static int
+rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
+		struct rss_reply_data *data, const struct genl_info *info)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_rxfh_param rxfh = {};
+	int ret;
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+	mutex_lock(&dev->ethtool->rss_lock);
+
+	ret = rss_get_data_alloc(dev, data);
+	if (ret)
+		goto out_unlock;
+
 	rxfh.indir_size = data->indir_size;
 	rxfh.indir = data->indir_table;
 	rxfh.key_size = data->hkey_size;
@@ -318,7 +331,7 @@ static void rss_cleanup_data(struct ethnl_reply_data *reply_base)
 {
 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
 
-	kfree(data->indir_table);
+	rss_get_data_free(data);
 }
 
 struct rss_nl_dump_ctx {
-- 
2.50.1

[PATCH net-next 4/8] ethtool: rss: factor out populating response from context

[Jakub Kicinski]

Similarly to previous change, factor out populating the response.
We will use this after the context was allocated to send a notification
so this time factor out from the additional context handling, rather
than context 0 handling (for request context didn't exist, for response
it does).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 net/ethtool/rss.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index 07a9d89e1c6b..e5516e529b4a 100644
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -179,6 +179,25 @@ rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
 	return ret;
 }
 
+static void
+__rss_prepare_ctx(struct net_device *dev, struct rss_reply_data *data,
+		  struct ethtool_rxfh_context *ctx)
+{
+	if (WARN_ON_ONCE(data->indir_size != ctx->indir_size ||
+			 data->hkey_size != ctx->key_size))
+		return;
+
+	data->no_key_fields = !dev->ethtool_ops->rxfh_per_ctx_key;
+
+	data->hfunc = ctx->hfunc;
+	data->input_xfrm = ctx->input_xfrm;
+	memcpy(data->indir_table, ethtool_rxfh_context_indir(ctx),
+	       data->indir_size * sizeof(u32));
+	if (data->hkey_size)
+		memcpy(data->hkey, ethtool_rxfh_context_key(ctx),
+		       data->hkey_size);
+}
+
 static int
 rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
 		struct rss_reply_data *data, const struct genl_info *info)
@@ -188,8 +207,6 @@ rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
 	u8 *rss_config;
 	int ret;
 
-	data->no_key_fields = !dev->ethtool_ops->rxfh_per_ctx_key;
-
 	mutex_lock(&dev->ethtool->rss_lock);
 	ctx = xa_load(&dev->ethtool->rss_ctx, request->rss_context);
 	if (!ctx) {
@@ -199,8 +216,6 @@ rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
 
 	data->indir_size = ctx->indir_size;
 	data->hkey_size = ctx->key_size;
-	data->hfunc = ctx->hfunc;
-	data->input_xfrm = ctx->input_xfrm;
 
 	indir_bytes = data->indir_size * sizeof(u32);
 	total_size = indir_bytes + data->hkey_size;
@@ -211,13 +226,10 @@ rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
 	}
 
 	data->indir_table = (u32 *)rss_config;
-	memcpy(data->indir_table, ethtool_rxfh_context_indir(ctx), indir_bytes);
-
-	if (data->hkey_size) {
+	if (data->hkey_size)
 		data->hkey = rss_config + indir_bytes;
-		memcpy(data->hkey, ethtool_rxfh_context_key(ctx),
-		       data->hkey_size);
-	}
+
+	__rss_prepare_ctx(dev, data, ctx);
 
 	ret = 0;
 out_unlock:
-- 
2.50.1

[PATCH net-next 5/8] ethtool: move ethtool_rxfh_ctx_alloc() to common code

[Jakub Kicinski]

Move ethtool_rxfh_ctx_alloc() to common code, Netlink will need it.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 net/ethtool/common.h |  3 +++
 net/ethtool/common.c | 34 ++++++++++++++++++++++++++++++++++
 net/ethtool/ioctl.c  | 34 ----------------------------------
 3 files changed, 37 insertions(+), 34 deletions(-)

diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index c8385a268ced..c4d084dde5bf 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -43,6 +43,9 @@ bool convert_legacy_settings_to_link_ksettings(
 int ethtool_check_max_channel(struct net_device *dev,
 			      struct ethtool_channels channels,
 			      struct genl_info *info);
+struct ethtool_rxfh_context *
+ethtool_rxfh_ctx_alloc(const struct ethtool_ops *ops,
+		       u32 indir_size, u32 key_size);
 int ethtool_check_rss_ctx_busy(struct net_device *dev, u32 rss_context);
 int ethtool_rxfh_config_is_sym(u64 rxfh);
 
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 82afe0f2a7cd..2a1d40efb1fc 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -806,6 +806,40 @@ int ethtool_check_rss_ctx_busy(struct net_device *dev, u32 rss_context)
 	return rc;
 }
 
+struct ethtool_rxfh_context *
+ethtool_rxfh_ctx_alloc(const struct ethtool_ops *ops,
+		       u32 indir_size, u32 key_size)
+{
+	size_t indir_bytes, flex_len, key_off, size;
+	struct ethtool_rxfh_context *ctx;
+	u32 priv_bytes, indir_max;
+	u16 key_max;
+
+	key_max = max(key_size, ops->rxfh_key_space);
+	indir_max = max(indir_size, ops->rxfh_indir_space);
+
+	priv_bytes = ALIGN(ops->rxfh_priv_size, sizeof(u32));
+	indir_bytes = array_size(indir_max, sizeof(u32));
+
+	key_off = size_add(priv_bytes, indir_bytes);
+	flex_len = size_add(key_off, key_max);
+	size = struct_size_t(struct ethtool_rxfh_context, data, flex_len);
+
+	ctx = kzalloc(size, GFP_KERNEL_ACCOUNT);
+	if (!ctx)
+		return NULL;
+
+	ctx->indir_size = indir_size;
+	ctx->key_size = key_size;
+	ctx->key_off = key_off;
+	ctx->priv_size = ops->rxfh_priv_size;
+
+	ctx->hfunc = ETH_RSS_HASH_NO_CHANGE;
+	ctx->input_xfrm = RXH_XFRM_NO_CHANGE;
+
+	return ctx;
+}
+
 /* Check if fields configured for flow hash are symmetric - if src is included
  * so is dst and vice versa.
  */
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index beb17f3671a2..c53868889969 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1473,40 +1473,6 @@ static noinline_for_stack int ethtool_get_rxfh(struct net_device *dev,
 	return ret;
 }
 
-static struct ethtool_rxfh_context *
-ethtool_rxfh_ctx_alloc(const struct ethtool_ops *ops,
-		       u32 indir_size, u32 key_size)
-{
-	size_t indir_bytes, flex_len, key_off, size;
-	struct ethtool_rxfh_context *ctx;
-	u32 priv_bytes, indir_max;
-	u16 key_max;
-
-	key_max = max(key_size, ops->rxfh_key_space);
-	indir_max = max(indir_size, ops->rxfh_indir_space);
-
-	priv_bytes = ALIGN(ops->rxfh_priv_size, sizeof(u32));
-	indir_bytes = array_size(indir_max, sizeof(u32));
-
-	key_off = size_add(priv_bytes, indir_bytes);
-	flex_len = size_add(key_off, key_max);
-	size = struct_size_t(struct ethtool_rxfh_context, data, flex_len);
-
-	ctx = kzalloc(size, GFP_KERNEL_ACCOUNT);
-	if (!ctx)
-		return NULL;
-
-	ctx->indir_size = indir_size;
-	ctx->key_size = key_size;
-	ctx->key_off = key_off;
-	ctx->priv_size = ops->rxfh_priv_size;
-
-	ctx->hfunc = ETH_RSS_HASH_NO_CHANGE;
-	ctx->input_xfrm = RXH_XFRM_NO_CHANGE;
-
-	return ctx;
-}
-
 static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 					       void __user *useraddr)
 {
-- 
2.50.1

[PATCH net-next 6/8] ethtool: rss: support creating contexts via Netlink

[Jakub Kicinski]

Support creating contexts via Netlink. Setting flow hashing
fields on the new context is not supported at this stage,
it can be added later.

An empty indirection table is not supported. This is a carry
over from the IOCTL interface where empty indirection table
meant delete. We can repurpose empty indirection table in
Netlink but for now to avoid confusion reject it using the
policy.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 Documentation/netlink/specs/ethtool.yaml      |  23 +-
 Documentation/networking/ethtool-netlink.rst  |  27 +++
 .../uapi/linux/ethtool_netlink_generated.h    |   3 +
 net/ethtool/netlink.h                         |   3 +
 net/ethtool/ioctl.c                           |   1 +
 net/ethtool/netlink.c                         |  15 ++
 net/ethtool/rss.c                             | 203 ++++++++++++++++++
 7 files changed, 273 insertions(+), 2 deletions(-)

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 069269edde01..25ffed5fddd5 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -2684,9 +2684,28 @@ c-version-name: ethtool-genl-version
       name: rss-ntf
       doc: |
         Notification for change in RSS configuration.
-        For additional contexts only modifications are modified, not creation
-        or removal of the contexts.
+        For additional contexts only modifications use this notification,
+        creation and deletion have dedicated messages.
       notify: rss-get
+    -
+      name: rss-create-act
+      doc: Create an RSS context.
+      attribute-set: rss
+      do:
+        request: &rss-create-attrs
+          attributes:
+            - header
+            - context
+            - hfunc
+            - indir
+            - hkey
+            - input-xfrm
+        reply: *rss-create-attrs
+    -
+      name: rss-create-ntf
+      doc: |
+        Notification for creation of an additional RSS context.
+      notify: rss-create-act
 
 mcast-groups:
   list:
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 056832c77ffd..2646fafb8512 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -240,6 +240,7 @@ All constants identifying message types use ``ETHTOOL_CMD_`` prefix and suffix
   ``ETHTOOL_MSG_TSCONFIG_GET``          get hw timestamping configuration
   ``ETHTOOL_MSG_TSCONFIG_SET``          set hw timestamping configuration
   ``ETHTOOL_MSG_RSS_SET``               set RSS settings
+  ``ETHTOOL_MSG_RSS_CREATE_ACT``        create an additional RSS context
   ===================================== =================================
 
 Kernel to userspace:
@@ -294,6 +295,8 @@ All constants identifying message types use ``ETHTOOL_CMD_`` prefix and suffix
   ``ETHTOOL_MSG_TSCONFIG_SET_REPLY``       new hw timestamping configuration
   ``ETHTOOL_MSG_PSE_NTF``                  PSE events notification
   ``ETHTOOL_MSG_RSS_NTF``                  RSS settings notification
+  ``ETHTOOL_MSG_RSS_CREATE_ACT_REPLY``     create an additional RSS context
+  ``ETHTOOL_MSG_RSS_CREATE_NTF``           additional RSS context created
   ======================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
@@ -2014,6 +2017,30 @@ device needs at least 8 entries - the real table in use will end up being
 of 2, so tables which size is not a power of 2 will likely be rejected.
 Using table of size 0 will reset the indirection table to the default.
 
+RSS_CREATE_ACT
+==============
+
+Request contents:
+
+=====================================  ======  ==============================
+  ``ETHTOOL_A_RSS_HEADER``             nested  request header
+  ``ETHTOOL_A_RSS_CONTEXT``            u32     context number
+  ``ETHTOOL_A_RSS_HFUNC``              u32     RSS hash func
+  ``ETHTOOL_A_RSS_INDIR``              binary  Indir table bytes
+  ``ETHTOOL_A_RSS_HKEY``               binary  Hash key bytes
+  ``ETHTOOL_A_RSS_INPUT_XFRM``         u32     RSS input data transformation
+=====================================  ======  ==============================
+
+Kernel response contents:
+
+=====================================  ======  ==============================
+  ``ETHTOOL_A_RSS_HEADER``             nested  request header
+  ``ETHTOOL_A_RSS_CONTEXT``            u32     context number
+=====================================  ======  ==============================
+
+Create an additional RSS context, if ``ETHTOOL_A_RSS_CONTEXT`` is not
+specified kernel will allocate one automatically.
+
 PLCA_GET_CFG
 ============
 
diff --git a/include/uapi/linux/ethtool_netlink_generated.h b/include/uapi/linux/ethtool_netlink_generated.h
index 130bdf5c3516..dea77abd295f 100644
--- a/include/uapi/linux/ethtool_netlink_generated.h
+++ b/include/uapi/linux/ethtool_netlink_generated.h
@@ -841,6 +841,7 @@ enum {
 	ETHTOOL_MSG_TSCONFIG_GET,
 	ETHTOOL_MSG_TSCONFIG_SET,
 	ETHTOOL_MSG_RSS_SET,
+	ETHTOOL_MSG_RSS_CREATE_ACT,
 
 	__ETHTOOL_MSG_USER_CNT,
 	ETHTOOL_MSG_USER_MAX = (__ETHTOOL_MSG_USER_CNT - 1)
@@ -898,6 +899,8 @@ enum {
 	ETHTOOL_MSG_TSCONFIG_SET_REPLY,
 	ETHTOOL_MSG_PSE_NTF,
 	ETHTOOL_MSG_RSS_NTF,
+	ETHTOOL_MSG_RSS_CREATE_ACT_REPLY,
+	ETHTOOL_MSG_RSS_CREATE_NTF,
 
 	__ETHTOOL_MSG_KERNEL_CNT,
 	ETHTOOL_MSG_KERNEL_MAX = (__ETHTOOL_MSG_KERNEL_CNT - 1)
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index ddb2fb00f929..b530bf9f85ee 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -10,6 +10,7 @@
 
 struct ethnl_req_info;
 
+u32 ethnl_bcast_seq_next(void);
 int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
 			       const struct nlattr *nest, struct net *net,
 			       struct netlink_ext_ack *extack,
@@ -485,6 +486,7 @@ extern const struct nla_policy ethnl_pse_get_policy[ETHTOOL_A_PSE_HEADER + 1];
 extern const struct nla_policy ethnl_pse_set_policy[ETHTOOL_A_PSE_MAX + 1];
 extern const struct nla_policy ethnl_rss_get_policy[ETHTOOL_A_RSS_START_CONTEXT + 1];
 extern const struct nla_policy ethnl_rss_set_policy[ETHTOOL_A_RSS_FLOW_HASH + 1];
+extern const struct nla_policy ethnl_rss_create_policy[ETHTOOL_A_RSS_INPUT_XFRM + 1];
 extern const struct nla_policy ethnl_plca_get_cfg_policy[ETHTOOL_A_PLCA_HEADER + 1];
 extern const struct nla_policy ethnl_plca_set_cfg_policy[ETHTOOL_A_PLCA_MAX + 1];
 extern const struct nla_policy ethnl_plca_get_status_policy[ETHTOOL_A_PLCA_HEADER + 1];
@@ -507,6 +509,7 @@ int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int ethnl_tsinfo_start(struct netlink_callback *cb);
 int ethnl_tsinfo_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int ethnl_tsinfo_done(struct netlink_callback *cb);
+int ethnl_rss_create_doit(struct sk_buff *skb, struct genl_info *info);
 
 extern const char stats_std_names[__ETHTOOL_STATS_CNT][ETH_GSTRING_LEN];
 extern const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING_LEN];
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index c53868889969..4b586b0f18e8 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1640,6 +1640,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		ntf = ETHTOOL_MSG_RSS_NTF;
 		ret = ops->set_rxfh(dev, &rxfh_dev, extack);
 	} else if (create) {
+		ntf = ETHTOOL_MSG_RSS_CREATE_NTF;
 		ret = ops->create_rxfh_context(dev, ctx, &rxfh_dev, extack);
 		/* Make sure driver populates defaults */
 		WARN_ON_ONCE(!ret && !rxfh_dev.key && ops->rxfh_per_ctx_key &&
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 0ae0d7a9667c..e9696113a96b 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -81,6 +81,12 @@ static void ethnl_sock_priv_destroy(void *priv)
 	}
 }
 
+u32 ethnl_bcast_seq_next(void)
+{
+	ASSERT_RTNL();
+	return ++ethnl_bcast_seq;
+}
+
 int ethnl_ops_begin(struct net_device *dev)
 {
 	int ret;
@@ -954,6 +960,7 @@ ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = {
 	[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,
+	[ETHTOOL_MSG_RSS_CREATE_NTF]	= &ethnl_rss_request_ops,
 };
 
 /* default notification handler */
@@ -1061,6 +1068,7 @@ static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
 	[ETHTOOL_MSG_PLCA_NTF]		= ethnl_default_notify,
 	[ETHTOOL_MSG_MM_NTF]		= ethnl_default_notify,
 	[ETHTOOL_MSG_RSS_NTF]		= ethnl_default_notify,
+	[ETHTOOL_MSG_RSS_CREATE_NTF]	= ethnl_default_notify,
 };
 
 void ethnl_notify(struct net_device *dev, unsigned int cmd,
@@ -1512,6 +1520,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.policy = ethnl_rss_set_policy,
 		.maxattr = ARRAY_SIZE(ethnl_rss_set_policy) - 1,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_RSS_CREATE_ACT,
+		.flags	= GENL_UNS_ADMIN_PERM,
+		.doit	= ethnl_rss_create_doit,
+		.policy	= ethnl_rss_create_policy,
+		.maxattr = ARRAY_SIZE(ethnl_rss_create_policy) - 1,
+	},
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index e5516e529b4a..be092dfa4407 100644
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -893,3 +893,206 @@ const struct ethnl_request_ops ethnl_rss_request_ops = {
 	.set			= ethnl_rss_set,
 	.set_ntf_cmd		= ETHTOOL_MSG_RSS_NTF,
 };
+
+/* RSS_CREATE */
+
+const struct nla_policy ethnl_rss_create_policy[ETHTOOL_A_RSS_INPUT_XFRM + 1] = {
+	[ETHTOOL_A_RSS_HEADER]	= NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_RSS_CONTEXT]	= NLA_POLICY_MIN(NLA_U32, 1),
+	[ETHTOOL_A_RSS_HFUNC]	= NLA_POLICY_MIN(NLA_U32, 1),
+	[ETHTOOL_A_RSS_INDIR]	= NLA_POLICY_MIN(NLA_BINARY, 1),
+	[ETHTOOL_A_RSS_HKEY]	= NLA_POLICY_MIN(NLA_BINARY, 1),
+	[ETHTOOL_A_RSS_INPUT_XFRM] =
+		NLA_POLICY_MAX(NLA_U32, RXH_XFRM_SYM_OR_XOR),
+};
+
+static int
+ethnl_rss_create_validate(struct net_device *dev, struct genl_info *info)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct nlattr **tb = info->attrs;
+	struct nlattr *bad_attr = NULL;
+	u32 rss_context, input_xfrm;
+
+	if (!ops->create_rxfh_context)
+		return -EOPNOTSUPP;
+
+	rss_context = nla_get_u32_default(tb[ETHTOOL_A_RSS_CONTEXT], 0);
+	if (ops->rxfh_max_num_contexts &&
+	    ops->rxfh_max_num_contexts <= rss_context) {
+		NL_SET_BAD_ATTR(info->extack, tb[ETHTOOL_A_RSS_CONTEXT]);
+		return -ERANGE;
+	}
+
+	if (!ops->rxfh_per_ctx_key) {
+		bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_HFUNC];
+		bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_HKEY];
+		bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_INPUT_XFRM];
+	}
+
+	input_xfrm = nla_get_u32_default(tb[ETHTOOL_A_RSS_INPUT_XFRM], 0);
+	if (input_xfrm & ~ops->supported_input_xfrm)
+		bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_INPUT_XFRM];
+
+	if (bad_attr) {
+		NL_SET_BAD_ATTR(info->extack, bad_attr);
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static void
+ethnl_rss_create_send_ntf(struct sk_buff *rsp, struct net_device *dev)
+{
+	struct nlmsghdr *nlh = (void *)rsp->data;
+	struct genlmsghdr *genl_hdr;
+
+	/* Convert the reply into a notification */
+	nlh->nlmsg_pid = 0;
+	nlh->nlmsg_seq = ethnl_bcast_seq_next();
+
+	genl_hdr = nlmsg_data(nlh);
+	genl_hdr->cmd =	ETHTOOL_MSG_RSS_CREATE_NTF;
+
+	ethnl_multicast(rsp, dev);
+}
+
+int ethnl_rss_create_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	bool indir_dflt = false, mod = false, ntf_fail = false;
+	struct ethtool_rxfh_param rxfh = {};
+	struct ethtool_rxfh_context *ctx;
+	struct nlattr **tb = info->attrs;
+	struct rss_reply_data data = {};
+	const struct ethtool_ops *ops;
+	struct rss_req_info req = {};
+	struct net_device *dev;
+	struct sk_buff *rsp;
+	void *hdr;
+	u32 limit;
+	int ret;
+
+	rsp = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!rsp)
+		return -ENOMEM;
+
+	ret = ethnl_parse_header_dev_get(&req.base, tb[ETHTOOL_A_RSS_HEADER],
+					 genl_info_net(info), info->extack,
+					 true);
+	if (ret < 0)
+		goto exit_free_rsp;
+
+	dev = req.base.dev;
+	ops = dev->ethtool_ops;
+
+	req.rss_context = nla_get_u32_default(tb[ETHTOOL_A_RSS_CONTEXT], 0);
+
+	ret = ethnl_rss_create_validate(dev, info);
+	if (ret)
+		goto exit_free_dev;
+
+	rtnl_lock();
+	netdev_lock_ops(dev);
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		goto exit_dev_unlock;
+
+	ret = rss_get_data_alloc(dev, &data);
+	if (ret)
+		goto exit_ops;
+
+	ret = rss_set_prep_indir(dev, info, &data, &rxfh, &indir_dflt, &mod);
+	if (ret)
+		goto exit_clean_data;
+
+	ethnl_update_u8(&rxfh.hfunc, tb[ETHTOOL_A_RSS_HFUNC], &mod);
+
+	ret = rss_set_prep_hkey(dev, info, &data, &rxfh, &mod);
+	if (ret)
+		goto exit_free_indir;
+
+	rxfh.input_xfrm = RXH_XFRM_NO_CHANGE;
+	ethnl_update_u8(&rxfh.input_xfrm, tb[ETHTOOL_A_RSS_INPUT_XFRM], &mod);
+
+	ctx = ethtool_rxfh_ctx_alloc(ops, data.indir_size, data.hkey_size);
+	if (!ctx) {
+		ret = -ENOMEM;
+		goto exit_free_hkey;
+	}
+
+	mutex_lock(&dev->ethtool->rss_lock);
+	if (!req.rss_context) {
+		limit = ops->rxfh_max_num_contexts ?: U32_MAX;
+		ret = xa_alloc(&dev->ethtool->rss_ctx, &req.rss_context, ctx,
+			       XA_LIMIT(1, limit - 1), GFP_KERNEL_ACCOUNT);
+	} else {
+		ret = xa_insert(&dev->ethtool->rss_ctx,
+				req.rss_context, ctx, GFP_KERNEL_ACCOUNT);
+	}
+	if (ret < 0) {
+		NL_SET_ERR_MSG_ATTR(info->extack, tb[ETHTOOL_A_RSS_CONTEXT],
+				    "error allocating context ID");
+		goto err_unlock_free_ctx;
+	}
+	rxfh.rss_context = req.rss_context;
+
+	ret = ops->create_rxfh_context(dev, ctx, &rxfh, info->extack);
+	if (ret)
+		goto err_ctx_id_free;
+
+	/* Make sure driver populates defaults */
+	WARN_ON_ONCE(!rxfh.key && ops->rxfh_per_ctx_key &&
+		     !memchr_inv(ethtool_rxfh_context_key(ctx), 0,
+				 ctx->key_size));
+
+	/* Store the config from rxfh to Xarray.. */
+	rss_set_ctx_update(ctx, tb, &data, &rxfh);
+	/* .. copy from Xarray to data. */
+	__rss_prepare_ctx(dev, &data, ctx);
+
+	hdr = ethnl_unicast_put(rsp, info->snd_portid, info->snd_seq,
+				ETHTOOL_MSG_RSS_CREATE_ACT_REPLY);
+	ntf_fail = ethnl_fill_reply_header(rsp, dev, ETHTOOL_A_RSS_HEADER);
+	ntf_fail |= rss_fill_reply(rsp, &req.base, &data.base);
+	if (WARN_ON(!hdr || ntf_fail)) {
+		ret = -EMSGSIZE;
+		goto exit_unlock;
+	}
+
+	genlmsg_end(rsp, hdr);
+
+	/* Use the same skb for the response and the notification,
+	 * genlmsg_reply() will copy the skb if it has elevated user count.
+	 */
+	skb_get(rsp);
+	ret = genlmsg_reply(rsp, info);
+	ethnl_rss_create_send_ntf(rsp, dev);
+	rsp = NULL;
+
+exit_unlock:
+	mutex_unlock(&dev->ethtool->rss_lock);
+exit_free_hkey:
+	kfree(rxfh.key);
+exit_free_indir:
+	kfree(rxfh.indir);
+exit_clean_data:
+	rss_get_data_free(&data);
+exit_ops:
+	ethnl_ops_complete(dev);
+exit_dev_unlock:
+	netdev_unlock_ops(dev);
+	rtnl_unlock();
+exit_free_dev:
+	ethnl_parse_header_dev_put(&req.base);
+exit_free_rsp:
+	nlmsg_free(rsp);
+	return ret;
+
+err_ctx_id_free:
+	xa_erase(&dev->ethtool->rss_ctx, req.rss_context);
+err_unlock_free_ctx:
+	kfree(ctx);
+	goto exit_unlock;
+}
-- 
2.50.1

[PATCH net-next 7/8] ethtool: rss: support removing contexts via Netlink

[Jakub Kicinski]

Implement removing additional RSS contexts via Netlink.
Technically it'd be possible to shoehorn the delete operation
into ethnl_request_ops-compatible handler. The code ends
up longer than open coded version, and I think we'll need
a custom way of sending notifications at some stage (if we
allow tying the context lifetime to the netlink socket, in
the future).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 Documentation/netlink/specs/ethtool.yaml      |  18 +++
 Documentation/networking/ethtool-netlink.rst  |  14 +++
 .../uapi/linux/ethtool_netlink_generated.h    |   2 +
 net/ethtool/netlink.h                         |   2 +
 net/ethtool/common.c                          |   1 +
 net/ethtool/ioctl.c                           |   1 +
 net/ethtool/netlink.c                         |   7 ++
 net/ethtool/rss.c                             | 109 +++++++++++++++++-
 8 files changed, 153 insertions(+), 1 deletion(-)

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 25ffed5fddd5..1063d5d32fea 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -2706,6 +2706,24 @@ c-version-name: ethtool-genl-version
       doc: |
         Notification for creation of an additional RSS context.
       notify: rss-create-act
+    -
+      name: rss-delete-act
+      doc: Delete an RSS context.
+      attribute-set: rss
+      do:
+        request:
+          attributes:
+            - header
+            - context
+    -
+      name: rss-delete-ntf
+      doc: |
+        Notification for deletion of an additional RSS context.
+      attribute-set: rss
+      event:
+        attributes:
+          - header
+          - context
 
 mcast-groups:
   list:
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 2646fafb8512..ab20c644af24 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -241,6 +241,7 @@ All constants identifying message types use ``ETHTOOL_CMD_`` prefix and suffix
   ``ETHTOOL_MSG_TSCONFIG_SET``          set hw timestamping configuration
   ``ETHTOOL_MSG_RSS_SET``               set RSS settings
   ``ETHTOOL_MSG_RSS_CREATE_ACT``        create an additional RSS context
+  ``ETHTOOL_MSG_RSS_DELETE_ACT``        delete an additional RSS context
   ===================================== =================================
 
 Kernel to userspace:
@@ -297,6 +298,7 @@ All constants identifying message types use ``ETHTOOL_CMD_`` prefix and suffix
   ``ETHTOOL_MSG_RSS_NTF``                  RSS settings notification
   ``ETHTOOL_MSG_RSS_CREATE_ACT_REPLY``     create an additional RSS context
   ``ETHTOOL_MSG_RSS_CREATE_NTF``           additional RSS context created
+  ``ETHTOOL_MSG_RSS_DELETE_NTF``           additional RSS context deleted
   ======================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
@@ -2041,6 +2043,18 @@ RSS_CREATE_ACT
 Create an additional RSS context, if ``ETHTOOL_A_RSS_CONTEXT`` is not
 specified kernel will allocate one automatically.
 
+RSS_DELETE_ACT
+==============
+
+Request contents:
+
+=====================================  ======  ==============================
+  ``ETHTOOL_A_RSS_HEADER``             nested  request header
+  ``ETHTOOL_A_RSS_CONTEXT``            u32     context number
+=====================================  ======  ==============================
+
+Delete an additional RSS context.
+
 PLCA_GET_CFG
 ============
 
diff --git a/include/uapi/linux/ethtool_netlink_generated.h b/include/uapi/linux/ethtool_netlink_generated.h
index dea77abd295f..e3b8813465d7 100644
--- a/include/uapi/linux/ethtool_netlink_generated.h
+++ b/include/uapi/linux/ethtool_netlink_generated.h
@@ -842,6 +842,7 @@ enum {
 	ETHTOOL_MSG_TSCONFIG_SET,
 	ETHTOOL_MSG_RSS_SET,
 	ETHTOOL_MSG_RSS_CREATE_ACT,
+	ETHTOOL_MSG_RSS_DELETE_ACT,
 
 	__ETHTOOL_MSG_USER_CNT,
 	ETHTOOL_MSG_USER_MAX = (__ETHTOOL_MSG_USER_CNT - 1)
@@ -901,6 +902,7 @@ enum {
 	ETHTOOL_MSG_RSS_NTF,
 	ETHTOOL_MSG_RSS_CREATE_ACT_REPLY,
 	ETHTOOL_MSG_RSS_CREATE_NTF,
+	ETHTOOL_MSG_RSS_DELETE_NTF,
 
 	__ETHTOOL_MSG_KERNEL_CNT,
 	ETHTOOL_MSG_KERNEL_MAX = (__ETHTOOL_MSG_KERNEL_CNT - 1)
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index b530bf9f85ee..1d4f9ecb3d26 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -487,6 +487,7 @@ extern const struct nla_policy ethnl_pse_set_policy[ETHTOOL_A_PSE_MAX + 1];
 extern const struct nla_policy ethnl_rss_get_policy[ETHTOOL_A_RSS_START_CONTEXT + 1];
 extern const struct nla_policy ethnl_rss_set_policy[ETHTOOL_A_RSS_FLOW_HASH + 1];
 extern const struct nla_policy ethnl_rss_create_policy[ETHTOOL_A_RSS_INPUT_XFRM + 1];
+extern const struct nla_policy ethnl_rss_delete_policy[ETHTOOL_A_RSS_CONTEXT + 1];
 extern const struct nla_policy ethnl_plca_get_cfg_policy[ETHTOOL_A_PLCA_HEADER + 1];
 extern const struct nla_policy ethnl_plca_set_cfg_policy[ETHTOOL_A_PLCA_MAX + 1];
 extern const struct nla_policy ethnl_plca_get_status_policy[ETHTOOL_A_PLCA_HEADER + 1];
@@ -510,6 +511,7 @@ int ethnl_tsinfo_start(struct netlink_callback *cb);
 int ethnl_tsinfo_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int ethnl_tsinfo_done(struct netlink_callback *cb);
 int ethnl_rss_create_doit(struct sk_buff *skb, struct genl_info *info);
+int ethnl_rss_delete_doit(struct sk_buff *skb, struct genl_info *info);
 
 extern const char stats_std_names[__ETHTOOL_STATS_CNT][ETH_GSTRING_LEN];
 extern const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING_LEN];
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 2a1d40efb1fc..4f58648a27ad 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -1136,5 +1136,6 @@ void ethtool_rxfh_context_lost(struct net_device *dev, u32 context_id)
 	netdev_err(dev, "device error, RSS context %d lost\n", context_id);
 	ctx = xa_erase(&dev->ethtool->rss_ctx, context_id);
 	kfree(ctx);
+	ethtool_rss_notify(dev, ETHTOOL_MSG_RSS_DELETE_NTF, context_id);
 }
 EXPORT_SYMBOL(ethtool_rxfh_context_lost);
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 4b586b0f18e8..43a7854e784e 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1647,6 +1647,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 			     !memchr_inv(ethtool_rxfh_context_key(ctx), 0,
 					 ctx->key_size));
 	} else if (rxfh_dev.rss_delete) {
+		ntf = ETHTOOL_MSG_RSS_DELETE_NTF;
 		ret = ops->remove_rxfh_context(dev, ctx, rxfh.rss_context,
 					       extack);
 	} else {
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index e9696113a96b..2f813f25f07e 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -1527,6 +1527,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.policy	= ethnl_rss_create_policy,
 		.maxattr = ARRAY_SIZE(ethnl_rss_create_policy) - 1,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_RSS_DELETE_ACT,
+		.flags	= GENL_UNS_ADMIN_PERM,
+		.doit	= ethnl_rss_delete_doit,
+		.policy	= ethnl_rss_delete_policy,
+		.maxattr = ARRAY_SIZE(ethnl_rss_delete_policy) - 1,
+	},
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index be092dfa4407..992e98abe9dd 100644
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -486,13 +486,49 @@ int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 
 /* RSS_NTF */
 
+static void ethnl_rss_delete_notify(struct net_device *dev, u32 rss_context)
+{
+	struct sk_buff *ntf;
+	size_t ntf_size;
+	void *hdr;
+
+	ntf_size = ethnl_reply_header_size() +
+		nla_total_size(sizeof(u32));	/* _RSS_CONTEXT */
+
+	ntf = genlmsg_new(ntf_size, GFP_KERNEL);
+	if (!ntf)
+		goto out_warn;
+
+	hdr = ethnl_bcastmsg_put(ntf, ETHTOOL_MSG_RSS_DELETE_NTF);
+	if (!hdr)
+		goto out_free_ntf;
+
+	if (ethnl_fill_reply_header(ntf, dev, ETHTOOL_A_RSS_HEADER) ||
+	    nla_put_u32(ntf, ETHTOOL_A_RSS_CONTEXT, rss_context))
+		goto out_free_ntf;
+
+	genlmsg_end(ntf, hdr);
+	if (ethnl_multicast(ntf, dev))
+		goto out_warn;
+
+	return;
+
+out_free_ntf:
+	nlmsg_free(ntf);
+out_warn:
+	pr_warn_once("Failed to send a RSS delete notification");
+}
+
 void ethtool_rss_notify(struct net_device *dev, u32 type, u32 rss_context)
 {
 	struct rss_req_info req_info = {
 		.rss_context = rss_context,
 	};
 
-	ethnl_notify(dev, type, &req_info.base);
+	if (type == ETHTOOL_MSG_RSS_DELETE_NTF)
+		ethnl_rss_delete_notify(dev, rss_context);
+	else
+		ethnl_notify(dev, type, &req_info.base);
 }
 
 /* RSS_SET */
@@ -1096,3 +1132,74 @@ int ethnl_rss_create_doit(struct sk_buff *skb, struct genl_info *info)
 	kfree(ctx);
 	goto exit_unlock;
 }
+
+/* RSS_DELETE */
+
+const struct nla_policy ethnl_rss_delete_policy[ETHTOOL_A_RSS_CONTEXT + 1] = {
+	[ETHTOOL_A_RSS_HEADER]	= NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_RSS_CONTEXT]	= NLA_POLICY_MIN(NLA_U32, 1),
+};
+
+int ethnl_rss_delete_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct ethtool_rxfh_context *ctx;
+	struct nlattr **tb = info->attrs;
+	struct ethnl_req_info req = {};
+	const struct ethtool_ops *ops;
+	struct net_device *dev;
+	u32 rss_context;
+	int ret;
+
+	if (GENL_REQ_ATTR_CHECK(info, ETHTOOL_A_RSS_CONTEXT))
+		return -EINVAL;
+	rss_context = nla_get_u32(tb[ETHTOOL_A_RSS_CONTEXT]);
+
+	ret = ethnl_parse_header_dev_get(&req, tb[ETHTOOL_A_RSS_HEADER],
+					 genl_info_net(info), info->extack,
+					 true);
+	if (ret < 0)
+		return ret;
+
+	dev = req.dev;
+	ops = dev->ethtool_ops;
+
+	if (!ops->create_rxfh_context)
+		goto exit_free_dev;
+
+	rtnl_lock();
+	netdev_lock_ops(dev);
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		goto exit_dev_unlock;
+
+	mutex_lock(&dev->ethtool->rss_lock);
+	ret = ethtool_check_rss_ctx_busy(dev, rss_context);
+	if (ret)
+		goto exit_unlock;
+
+	ctx = xa_load(&dev->ethtool->rss_ctx, rss_context);
+	if (!ctx) {
+		ret = -ENOENT;
+		goto exit_unlock;
+	}
+
+	ret = ops->remove_rxfh_context(dev, ctx, rss_context, info->extack);
+	if (ret)
+		goto exit_unlock;
+
+	WARN_ON(xa_erase(&dev->ethtool->rss_ctx, rss_context) != ctx);
+	kfree(ctx);
+
+	ethnl_rss_delete_notify(dev, rss_context);
+
+exit_unlock:
+	mutex_unlock(&dev->ethtool->rss_lock);
+	ethnl_ops_complete(dev);
+exit_dev_unlock:
+	netdev_unlock_ops(dev);
+	rtnl_unlock();
+exit_free_dev:
+	ethnl_parse_header_dev_put(&req);
+	return ret;
+}
-- 
2.50.1

[PATCH net-next 8/8] selftests: drv-net: rss_api: context create and delete tests

[Jakub Kicinski]

Add test cases for creating and deleting contexts.

  TAP version 13
  1..12
  ok 1 rss_api.test_rxfh_nl_set_fail
  ok 2 rss_api.test_rxfh_nl_set_indir
  ok 3 rss_api.test_rxfh_nl_set_indir_ctx
  ok 4 rss_api.test_rxfh_indir_ntf
  ok 5 rss_api.test_rxfh_indir_ctx_ntf
  ok 6 rss_api.test_rxfh_nl_set_key
  ok 7 rss_api.test_rxfh_fields
  ok 8 rss_api.test_rxfh_fields_set
  ok 9 rss_api.test_rxfh_fields_set_xfrm # SKIP no input-xfrm supported
  ok 10 rss_api.test_rxfh_fields_ntf
  ok 11 rss_api.test_rss_ctx_add
  ok 12 rss_api.test_rss_ctx_ntf
  # Totals: pass:11 fail:0 xfail:0 xpass:0 skip:1 error:0

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 .../selftests/drivers/net/hw/rss_api.py       | 73 +++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/tools/testing/selftests/drivers/net/hw/rss_api.py b/tools/testing/selftests/drivers/net/hw/rss_api.py
index 424743bb583b..19847f3d4a00 100755
--- a/tools/testing/selftests/drivers/net/hw/rss_api.py
+++ b/tools/testing/selftests/drivers/net/hw/rss_api.py
@@ -5,6 +5,7 @@
 API level tests for RSS (mostly Netlink vs IOCTL).
 """
 
+import errno
 import glob
 import random
 from lib.py import ksft_run, ksft_exit, ksft_eq, ksft_is, ksft_ne, ksft_raises
@@ -390,6 +391,78 @@ from lib.py import NetDrvEnv
     ksft_eq(next(ethnl.poll_ntf(duration=0.01), None), None)
 
 
+def test_rss_ctx_add(cfg):
+    """ Test creating an additional RSS context via Netlink """
+
+    _require_2qs(cfg)
+
+    # Test basic creation
+    ctx = cfg.ethnl.rss_create_act({"header": {"dev-index": cfg.ifindex}})
+    d = defer(ethtool, f"-X {cfg.ifname} context {ctx.get('context')} delete")
+    ksft_ne(ctx.get("context", 0), 0)
+    ksft_ne(set(ctx.get("indir", [0])), {0},
+            comment="Driver should init the indirection table")
+
+    # Try requesting the ID we just got allocated
+    with ksft_raises(NlError) as cm:
+        ctx = cfg.ethnl.rss_create_act({
+            "header": {"dev-index": cfg.ifindex},
+            "context": ctx.get("context"),
+        })
+        ethtool(f"-X {cfg.ifname} context {ctx.get('context')} delete")
+    d.exec()
+    ksft_eq(cm.exception.nl_msg.error, -errno.EBUSY)
+
+    # Test creating with a specified RSS table, and context ID
+    ctx_id = ctx.get("context")
+    ctx = cfg.ethnl.rss_create_act({
+        "header": {"dev-index": cfg.ifindex},
+        "context": ctx_id,
+        "indir": [1],
+    })
+    ethtool(f"-X {cfg.ifname} context {ctx.get('context')} delete")
+    ksft_eq(ctx.get("context"), ctx_id)
+    ksft_eq(set(ctx.get("indir", [0])), {1})
+
+
+def test_rss_ctx_ntf(cfg):
+    """ Test notifications for creating additional RSS contexts """
+
+    ethnl = EthtoolFamily()
+    ethnl.ntf_subscribe("monitor")
+
+    # Create / delete via Netlink
+    ctx = cfg.ethnl.rss_create_act({"header": {"dev-index": cfg.ifindex}})
+    cfg.ethnl.rss_delete_act({
+        "header": {"dev-index": cfg.ifindex},
+        "context": ctx["context"],
+    })
+
+    ntf = next(ethnl.poll_ntf(duration=0.2), None)
+    if ntf is None:
+        raise KsftFailEx("[NL] No notification after context creation")
+    ksft_eq(ntf["name"], "rss-create-ntf")
+    ksft_eq(ctx, ntf["msg"])
+
+    ntf = next(ethnl.poll_ntf(duration=0.2), None)
+    if ntf is None:
+        raise KsftFailEx("[NL] No notification after context deletion")
+    ksft_eq(ntf["name"], "rss-delete-ntf")
+
+    # Create / deleve via IOCTL
+    ctx_id = _ethtool_create(cfg, "--disable-netlink -X", "context new")
+    ethtool(f"--disable-netlink -X {cfg.ifname} context {ctx_id} delete")
+    ntf = next(ethnl.poll_ntf(duration=0.2), None)
+    if ntf is None:
+        raise KsftFailEx("[IOCTL] No notification after context creation")
+    ksft_eq(ntf["name"], "rss-create-ntf")
+
+    ntf = next(ethnl.poll_ntf(duration=0.2), None)
+    if ntf is None:
+        raise KsftFailEx("[IOCTL] No notification after context deletion")
+    ksft_eq(ntf["name"], "rss-delete-ntf")
+
+
 def main() -> None:
     """ Ksft boiler plate main """
 
-- 
2.50.1

Re: [PATCH net-next 2/8] ethtool: rejig the RSS notification machinery for more types

[Gal Pressman]

On 18/07/2025 2:43, Jakub Kicinski wrote:
> In anticipation for CREATE and DELETE notifications - explicitly
> pass the notification type to ethtool_rss_notify(), when calling
> from the IOCTL code.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Gal Pressman <gal@nvidia.com>

Re: [PATCH net-next 4/8] ethtool: rss: factor out populating response from context

[Gal Pressman]

On 18/07/2025 2:43, Jakub Kicinski wrote:
> Similarly to previous change, factor out populating the response.
> We will use this after the context was allocated to send a notification
> so this time factor out from the additional context handling, rather
> than context 0 handling (for request context didn't exist, for response
> it does).
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Gal Pressman <gal@nvidia.com>

> ---
>  net/ethtool/rss.c | 32 ++++++++++++++++++++++----------
>  1 file changed, 22 insertions(+), 10 deletions(-)
> 
> diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
> index 07a9d89e1c6b..e5516e529b4a 100644
> --- a/net/ethtool/rss.c
> +++ b/net/ethtool/rss.c
> @@ -179,6 +179,25 @@ rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
>  	return ret;
>  }
>  
> +static void
> +__rss_prepare_ctx(struct net_device *dev, struct rss_reply_data *data,
> +		  struct ethtool_rxfh_context *ctx)
> +{
> +	if (WARN_ON_ONCE(data->indir_size != ctx->indir_size ||
> +			 data->hkey_size != ctx->key_size))

I Wouldn't consider this part of "factoring out".

Re: [PATCH net-next 5/8] ethtool: move ethtool_rxfh_ctx_alloc() to common code

[Gal Pressman]

On 18/07/2025 2:43, Jakub Kicinski wrote:
> Move ethtool_rxfh_ctx_alloc() to common code, Netlink will need it.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Gal Pressman <gal@nvidia.com>

Re: [PATCH net-next 6/8] ethtool: rss: support creating contexts via Netlink

[Gal Pressman]

On 18/07/2025 2:43, Jakub Kicinski wrote:
> +Kernel response contents:
> +
> +=====================================  ======  ==============================
> +  ``ETHTOOL_A_RSS_HEADER``             nested  request header
> +  ``ETHTOOL_A_RSS_CONTEXT``            u32     context number
> +=====================================  ======  ==============================
> +
> +Create an additional RSS context, if ``ETHTOOL_A_RSS_CONTEXT`` is not
> +specified kernel will allocate one automatically.

We don't support choosing the context id from userspace in ioctl flow, I
think it should be stated somewhere (at the least, in the commit message?).

Re: [PATCH net-next 6/8] ethtool: rss: support creating contexts via Netlink

[Jakub Kicinski]

On Sun, 20 Jul 2025 14:42:36 +0300 Gal Pressman wrote:
> On 18/07/2025 2:43, Jakub Kicinski wrote:
> > +Kernel response contents:
> > +
> > +=====================================  ======  ==============================
> > +  ``ETHTOOL_A_RSS_HEADER``             nested  request header
> > +  ``ETHTOOL_A_RSS_CONTEXT``            u32     context number
> > +=====================================  ======  ==============================
> > +
> > +Create an additional RSS context, if ``ETHTOOL_A_RSS_CONTEXT`` is not
> > +specified kernel will allocate one automatically.  
> 
> We don't support choosing the context id from userspace in ioctl flow, I
> think it should be stated somewhere (at the least, in the commit message?).

Sure, how about:

  Support letting user choose the ID for the new context. This was not
  possible in IOCTL since the context ID field for the create action had
  to be set to the ETH_RXFH_CONTEXT_ALLOC magic value.

Re: [PATCH net-next 6/8] ethtool: rss: support creating contexts via Netlink

[Gal Pressman]

On 21/07/2025 18:21, Jakub Kicinski wrote:
> On Sun, 20 Jul 2025 14:42:36 +0300 Gal Pressman wrote:
>> On 18/07/2025 2:43, Jakub Kicinski wrote:
>>> +Kernel response contents:
>>> +
>>> +=====================================  ======  ==============================
>>> +  ``ETHTOOL_A_RSS_HEADER``             nested  request header
>>> +  ``ETHTOOL_A_RSS_CONTEXT``            u32     context number
>>> +=====================================  ======  ==============================
>>> +
>>> +Create an additional RSS context, if ``ETHTOOL_A_RSS_CONTEXT`` is not
>>> +specified kernel will allocate one automatically.  
>>
>> We don't support choosing the context id from userspace in ioctl flow, I
>> think it should be stated somewhere (at the least, in the commit message?).
> 
> Sure, how about:
> 
>   Support letting user choose the ID for the new context. This was not
>   possible in IOCTL since the context ID field for the create action had
>   to be set to the ETH_RXFH_CONTEXT_ALLOC magic value.

Perfect, thanks!

Re: [PATCH net-next 0/8] ethtool: rss: support creating and removing contexts via Netlink

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 17 Jul 2025 16:43:35 -0700 you wrote:
> This series completes support of RSS configuration via Netlink.
> All functionality supported by the IOCTL is now supported by
> Netlink. Future series (time allowing) will add:
>  - hashing on the flow label, which started this whole thing;
>  - pinning the RSS context to a Netlink socket for auto-cleanup.
> 
> The first patch is a leftover held back from previous series
> to avoid conflicting with Gal's fix.
> 
> [...]

Here is the summary with links:
  - [net-next,1/8] ethtool: assert that drivers with sym hash are consistent for RSS contexts
    https://git.kernel.org/netdev/net-next/c/80e55735d5a5
  - [net-next,2/8] ethtool: rejig the RSS notification machinery for more types
    https://git.kernel.org/netdev/net-next/c/5f5c59b78e5a
  - [net-next,3/8] ethtool: rss: factor out allocating memory for response
    https://git.kernel.org/netdev/net-next/c/a45f98efa483
  - [net-next,4/8] ethtool: rss: factor out populating response from context
    https://git.kernel.org/netdev/net-next/c/5c090d9eae88
  - [net-next,5/8] ethtool: move ethtool_rxfh_ctx_alloc() to common code
    https://git.kernel.org/netdev/net-next/c/55ef461ce18f
  - [net-next,6/8] ethtool: rss: support creating contexts via Netlink
    https://git.kernel.org/netdev/net-next/c/a166ab7816c5
  - [net-next,7/8] ethtool: rss: support removing contexts via Netlink
    https://git.kernel.org/netdev/net-next/c/fbe09277fa63
  - [net-next,8/8] selftests: drv-net: rss_api: context create and delete tests
    https://git.kernel.org/netdev/net-next/c/4c86c9fdf6a5

You are awesome, thank you!
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