[Intel-wired-lan] [PATCH iwl-next v1 0/3] igb: add RSS key get/set support

[Intel-wired-lan] [PATCH iwl-next v1 0/3] igb: add RSS key get/set support

[Takashi Kozu]

This series adds ethtool get/set support for the RSS hash key in the igb
driver.
- `ethtool -x <dev>` to display the RSS key
- `ethtool -X <dev> hkey <key>` to configure the RSS key

Without patch:

# ethtool -x $DEV | grep key -A1
RSS hash key:
Operation not supported
# ethtool -X $DEV hkey 00:00:00:00:00:00:00:00:00:00:00:00:000
Cannot set RX flow hash configuration:
  Hash key setting not supported


With patch:

# ethtool -x $DEV | grep key -A1
RSS hash key:
86:5d:11:56:bd:6f:20:38:3b:f8:bb:df:00:3a:b0:24:95:9f:f9:f4:25:a3:01:3e:4a:15:d6:7c:4d:af:39:7e:4a:95:f2:fd:f6:b6:26:f7

# ethtool -X $DEV hkey 00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
# ethtool -x $DEV | grep key -A1
RSS hash key:
00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00

Takashi Kozu (3):
  Store the RSS key inside struct igb_adapter and introduce the
  igb: expose RSS key via ethtool get_rxfh
  igb: allow configuring RSS key via ethtool set_rxfh

 drivers/net/ethernet/intel/igb/igb.h         |  4 +
 drivers/net/ethernet/intel/igb/igb_ethtool.c | 77 +++++++++++++-------
 drivers/net/ethernet/intel/igb/igb_main.c    |  7 +-
 3 files changed, 58 insertions(+), 30 deletions(-)

-- 
2.51.1

[Intel-wired-lan] [PATCH iwl-next v1 1/3] Store the RSS key inside struct igb_adapter and introduce the

[Takashi Kozu]

Store the RSS key inside struct igb_adapter and introduce the
igb_write_rss_key() helper function. This allows the driver to program
the E1000 registers using a persistent RSS key, instead of using a
stack-local buffer in igb_setup_mrqc().

Tested-by: Kohei Enju <enjuk@amazon.com>
Signed-off-by: Takashi Kozu <takkozu@amazon.com>
---
 drivers/net/ethernet/intel/igb/igb.h         |  3 +++
 drivers/net/ethernet/intel/igb/igb_ethtool.c | 12 ++++++++++++
 drivers/net/ethernet/intel/igb/igb_main.c    |  6 ++----
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 0fff1df81b7b..8c9b02058cec 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -495,6 +495,7 @@ struct hwmon_buff {
 #define IGB_N_PEROUT	2
 #define IGB_N_SDP	4
 #define IGB_RETA_SIZE	128
+#define IGB_RSS_KEY_SIZE	40
 
 enum igb_filter_match_flags {
 	IGB_FILTER_FLAG_ETHER_TYPE = 0x1,
@@ -655,6 +656,7 @@ struct igb_adapter {
 	struct i2c_client *i2c_client;
 	u32 rss_indir_tbl_init;
 	u8 rss_indir_tbl[IGB_RETA_SIZE];
+	u8 rss_key[IGB_RSS_KEY_SIZE];
 
 	unsigned long link_check_timeout;
 	int copper_tries;
@@ -735,6 +737,7 @@ void igb_down(struct igb_adapter *);
 void igb_reinit_locked(struct igb_adapter *);
 void igb_reset(struct igb_adapter *);
 int igb_reinit_queues(struct igb_adapter *);
+void igb_write_rss_key(struct igb_adapter *adapter);
 void igb_write_rss_indir_tbl(struct igb_adapter *);
 int igb_set_spd_dplx(struct igb_adapter *, u32, u8);
 int igb_setup_tx_resources(struct igb_ring *);
diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index 10e2445e0ded..8695ff28a7b8 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -3016,6 +3016,18 @@ static int igb_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *cmd)
 	return ret;
 }
 
+void igb_write_rss_key(struct igb_adapter *adapter)
+{
+	struct e1000_hw *hw = &adapter->hw;
+	u32 val;
+	int i;
+
+	for (i = 0; i < IGB_RSS_KEY_SIZE / 4; i++) {
+		val = get_unaligned_le32(&adapter->rss_key[i * 4]);
+		wr32(E1000_RSSRK(i), val);
+	}
+}
+
 static int igb_get_eee(struct net_device *netdev, struct ethtool_keee *edata)
 {
 	struct igb_adapter *adapter = netdev_priv(netdev);
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 85f9589cc568..da0f550de605 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -4525,11 +4525,9 @@ static void igb_setup_mrqc(struct igb_adapter *adapter)
 	struct e1000_hw *hw = &adapter->hw;
 	u32 mrqc, rxcsum;
 	u32 j, num_rx_queues;
-	u32 rss_key[10];
 
-	netdev_rss_key_fill(rss_key, sizeof(rss_key));
-	for (j = 0; j < 10; j++)
-		wr32(E1000_RSSRK(j), rss_key[j]);
+	netdev_rss_key_fill(adapter->rss_key, sizeof(adapter->rss_key));
+	igb_write_rss_key(adapter);
 
 	num_rx_queues = adapter->rss_queues;
 
-- 
2.51.1

[Intel-wired-lan] [PATCH iwl-next v1 2/3] igb: expose RSS key via ethtool get_rxfh

[Takashi Kozu]

Implement igc_get_rxfh_key_size() and extend
igc_get_rxfh() to return the RSS key to userspace.

This can be tested using `ethtool -x <dev>`.

Tested-by: Kohei Enju <enjuk@amazon.com>
Signed-off-by: Takashi Kozu <takkozu@amazon.com>
---
 drivers/net/ethernet/intel/igb/igb_ethtool.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index 8695ff28a7b8..2953d079ebae 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -3285,11 +3285,13 @@ static int igb_get_rxfh(struct net_device *netdev,
 	int i;
 
 	rxfh->hfunc = ETH_RSS_HASH_TOP;
-	if (!rxfh->indir)
-		return 0;
-	for (i = 0; i < IGB_RETA_SIZE; i++)
-		rxfh->indir[i] = adapter->rss_indir_tbl[i];
 
+	if (rxfh->indir)
+		for (i = 0; i < IGB_RETA_SIZE; i++)
+			rxfh->indir[i] = adapter->rss_indir_tbl[i];
+
+	if (rxfh->key)
+		memcpy(rxfh->key, adapter->rss_key, sizeof(adapter->rss_key));
 	return 0;
 }
 
@@ -3328,6 +3330,11 @@ void igb_write_rss_indir_tbl(struct igb_adapter *adapter)
 	}
 }
 
+static u32 igb_get_rxfh_key_size(struct net_device *netdev)
+{
+	return IGB_RSS_KEY_SIZE;
+}
+
 static int igb_set_rxfh(struct net_device *netdev,
 			struct ethtool_rxfh_param *rxfh,
 			struct netlink_ext_ack *extack)
@@ -3491,6 +3498,7 @@ static const struct ethtool_ops igb_ethtool_ops = {
 	.get_module_eeprom	= igb_get_module_eeprom,
 	.get_rxfh_indir_size	= igb_get_rxfh_indir_size,
 	.get_rxfh		= igb_get_rxfh,
+	.get_rxfh_key_size	= igb_get_rxfh_key_size,
 	.set_rxfh		= igb_set_rxfh,
 	.get_rxfh_fields	= igb_get_rxfh_fields,
 	.set_rxfh_fields	= igb_set_rxfh_fields,
-- 
2.51.1

Re: [Intel-wired-lan] [PATCH iwl-next v1 2/3] igb: expose RSS key via ethtool get_rxfh

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Takashi Kozu
> Sent: Friday, December 5, 2025 9:21 AM
> To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>
> Cc: Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>;
> andrew+netdev@lunn.ch; davem@davemloft.net; edumazet@google.com;
> kuba@kernel.org; pabeni@redhat.com; intel-wired-lan@lists.osuosl.org;
> netdev@vger.kernel.org; Takashi Kozu <takkozu@amazon.com>; Kohei Enju
> <enjuk@amazon.com>
> Subject: [Intel-wired-lan] [PATCH iwl-next v1 2/3] igb: expose RSS key
> via ethtool get_rxfh
> 
> Implement igc_get_rxfh_key_size() and extend
> igc_get_rxfh() to return the RSS key to userspace.
> 
> This can be tested using `ethtool -x <dev>`.
> 

nit (commit message): s/igc_get_rxfh_key_size()/igb_get_rxfh_key_size()/; s/igc_get_rxfh()/igb_get_rxfh()/.
The code implements igb_* symbols and wires them into igb_ethtool_ops, so the message should match the actual driver.

With the best regards
Alex

> Tested-by: Kohei Enju <enjuk@amazon.com>
> Signed-off-by: Takashi Kozu <takkozu@amazon.com>
> ---
>  drivers/net/ethernet/intel/igb/igb_ethtool.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> index 8695ff28a7b8..2953d079ebae 100644
> --- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> +++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> @@ -3285,11 +3285,13 @@ static int igb_get_rxfh(struct net_device
> *netdev,
>  	int i;
> 
>  	rxfh->hfunc = ETH_RSS_HASH_TOP;
> -	if (!rxfh->indir)
> -		return 0;
> -	for (i = 0; i < IGB_RETA_SIZE; i++)
> -		rxfh->indir[i] = adapter->rss_indir_tbl[i];
> 
> +	if (rxfh->indir)
> +		for (i = 0; i < IGB_RETA_SIZE; i++)
> +			rxfh->indir[i] = adapter->rss_indir_tbl[i];
> +
> +	if (rxfh->key)
> +		memcpy(rxfh->key, adapter->rss_key, sizeof(adapter-
> >rss_key));
>  	return 0;
>  }
> 
> @@ -3328,6 +3330,11 @@ void igb_write_rss_indir_tbl(struct igb_adapter
> *adapter)
>  	}
>  }
> 
> +static u32 igb_get_rxfh_key_size(struct net_device *netdev) {
> +	return IGB_RSS_KEY_SIZE;
> +}
> +
>  static int igb_set_rxfh(struct net_device *netdev,
>  			struct ethtool_rxfh_param *rxfh,
>  			struct netlink_ext_ack *extack)
> @@ -3491,6 +3498,7 @@ static const struct ethtool_ops igb_ethtool_ops
> = {
>  	.get_module_eeprom	= igb_get_module_eeprom,
>  	.get_rxfh_indir_size	= igb_get_rxfh_indir_size,
>  	.get_rxfh		= igb_get_rxfh,
> +	.get_rxfh_key_size	= igb_get_rxfh_key_size,
>  	.set_rxfh		= igb_set_rxfh,
>  	.get_rxfh_fields	= igb_get_rxfh_fields,
>  	.set_rxfh_fields	= igb_set_rxfh_fields,
> --
> 2.51.1

[Intel-wired-lan] [PATCH iwl-next v1 3/3] igb: allow configuring RSS key via ethtool set_rxfh

[Takashi Kozu]

Change igc_set_rxfh() to accept and save a userspace-provided
RSS key. When a key is provided, store it in the adapter and write the
E1000 registers accordingly.

This can be tested using `ethtool -X <dev> hkey <key>`.

Tested-by: Kohei Enju <enjuk@amazon.com>
Signed-off-by: Takashi Kozu <takkozu@amazon.com>
---
 drivers/net/ethernet/intel/igb/igb.h         |  1 +
 drivers/net/ethernet/intel/igb/igb_ethtool.c | 49 +++++++++++---------
 drivers/net/ethernet/intel/igb/igb_main.c    |  3 +-
 3 files changed, 30 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 8c9b02058cec..2509ec30acf3 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -657,6 +657,7 @@ struct igb_adapter {
 	u32 rss_indir_tbl_init;
 	u8 rss_indir_tbl[IGB_RETA_SIZE];
 	u8 rss_key[IGB_RSS_KEY_SIZE];
+	bool has_user_rss_key;
 
 	unsigned long link_check_timeout;
 	int copper_tries;
diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index 2953d079ebae..ac045fbebade 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -3345,35 +3345,40 @@ static int igb_set_rxfh(struct net_device *netdev,
 	u32 num_queues;
 
 	/* We do not allow change in unsupported parameters */
-	if (rxfh->key ||
-	    (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE &&
-	     rxfh->hfunc != ETH_RSS_HASH_TOP))
+	if (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE &&
+	    rxfh->hfunc != ETH_RSS_HASH_TOP)
 		return -EOPNOTSUPP;
-	if (!rxfh->indir)
-		return 0;
 
-	num_queues = adapter->rss_queues;
+	if (rxfh->indir) {
+		num_queues = adapter->rss_queues;
 
-	switch (hw->mac.type) {
-	case e1000_82576:
-		/* 82576 supports 2 RSS queues for SR-IOV */
-		if (adapter->vfs_allocated_count)
-			num_queues = 2;
-		break;
-	default:
-		break;
-	}
+		switch (hw->mac.type) {
+		case e1000_82576:
+			/* 82576 supports 2 RSS queues for SR-IOV */
+			if (adapter->vfs_allocated_count)
+				num_queues = 2;
+			break;
+		default:
+			break;
+		}
 
-	/* Verify user input. */
-	for (i = 0; i < IGB_RETA_SIZE; i++)
-		if (rxfh->indir[i] >= num_queues)
-			return -EINVAL;
+		/* Verify user input. */
+		for (i = 0; i < IGB_RETA_SIZE; i++)
+			if (rxfh->indir[i] >= num_queues)
+				return -EINVAL;
 
 
-	for (i = 0; i < IGB_RETA_SIZE; i++)
-		adapter->rss_indir_tbl[i] = rxfh->indir[i];
+		for (i = 0; i < IGB_RETA_SIZE; i++)
+			adapter->rss_indir_tbl[i] = rxfh->indir[i];
+
+		igb_write_rss_indir_tbl(adapter);
+	}
 
-	igb_write_rss_indir_tbl(adapter);
+	if (rxfh->key) {
+		adapter->has_user_rss_key = true;
+		memcpy(adapter->rss_key, rxfh->key, sizeof(adapter->rss_key));
+		igb_write_rss_key(adapter);
+	}
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index da0f550de605..d42b3750f0b1 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -4526,7 +4526,8 @@ static void igb_setup_mrqc(struct igb_adapter *adapter)
 	u32 mrqc, rxcsum;
 	u32 j, num_rx_queues;
 
-	netdev_rss_key_fill(adapter->rss_key, sizeof(adapter->rss_key));
+	if (!adapter->has_user_rss_key)
+		netdev_rss_key_fill(adapter->rss_key, sizeof(adapter->rss_key));
 	igb_write_rss_key(adapter);
 
 	num_rx_queues = adapter->rss_queues;
-- 
2.51.1

Re: [Intel-wired-lan] [PATCH iwl-next v1 3/3] igb: allow configuring RSS key via ethtool set_rxfh

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Takashi Kozu
> Sent: Friday, December 5, 2025 9:21 AM
> To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>
> Cc: Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>;
> andrew+netdev@lunn.ch; davem@davemloft.net; edumazet@google.com;
> kuba@kernel.org; pabeni@redhat.com; intel-wired-lan@lists.osuosl.org;
> netdev@vger.kernel.org; Takashi Kozu <takkozu@amazon.com>; Kohei Enju
> <enjuk@amazon.com>
> Subject: [Intel-wired-lan] [PATCH iwl-next v1 3/3] igb: allow
> configuring RSS key via ethtool set_rxfh
> 
> Change igc_set_rxfh() to accept and save a userspace-provided RSS key.
> When a key is provided, store it in the adapter and write the
> E1000 registers accordingly.
> 
> This can be tested using `ethtool -X <dev> hkey <key>`.
> 

nit (commit message): s/igc_set_rxfh()/igb_set_rxfh()/ throughout.
All modified call-sites and symbols are in drivers/net/ethernet/intel/igb/*, not igc.

> Tested-by: Kohei Enju <enjuk@amazon.com>
> Signed-off-by: Takashi Kozu <takkozu@amazon.com>
> ---
>  drivers/net/ethernet/intel/igb/igb.h         |  1 +
>  drivers/net/ethernet/intel/igb/igb_ethtool.c | 49 +++++++++++--------
> -
>  drivers/net/ethernet/intel/igb/igb_main.c    |  3 +-
>  3 files changed, 30 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb.h
> b/drivers/net/ethernet/intel/igb/igb.h
> index 8c9b02058cec..2509ec30acf3 100644
> --- a/drivers/net/ethernet/intel/igb/igb.h
> +++ b/drivers/net/ethernet/intel/igb/igb.h
> @@ -657,6 +657,7 @@ struct igb_adapter {
>  	u32 rss_indir_tbl_init;
>  	u8 rss_indir_tbl[IGB_RETA_SIZE];
>  	u8 rss_key[IGB_RSS_KEY_SIZE];
> +	bool has_user_rss_key;
> 
>  	unsigned long link_check_timeout;
>  	int copper_tries;
> diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> index 2953d079ebae..ac045fbebade 100644
> --- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> +++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> @@ -3345,35 +3345,40 @@ static int igb_set_rxfh(struct net_device
> *netdev,
>  	u32 num_queues;
> 
>  	/* We do not allow change in unsupported parameters */
> -	if (rxfh->key ||
> -	    (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE &&
> -	     rxfh->hfunc != ETH_RSS_HASH_TOP))
> +	if (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE &&
> +	    rxfh->hfunc != ETH_RSS_HASH_TOP)
>  		return -EOPNOTSUPP;
> -	if (!rxfh->indir)
> -		return 0;
> 
> -	num_queues = adapter->rss_queues;
> +	if (rxfh->indir) {
> +		num_queues = adapter->rss_queues;
> 
> -	switch (hw->mac.type) {
> -	case e1000_82576:
> -		/* 82576 supports 2 RSS queues for SR-IOV */
> -		if (adapter->vfs_allocated_count)
> -			num_queues = 2;
> -		break;
> -	default:
> -		break;
> -	}
> +		switch (hw->mac.type) {
> +		case e1000_82576:
> +			/* 82576 supports 2 RSS queues for SR-IOV */
> +			if (adapter->vfs_allocated_count)
> +				num_queues = 2;
> +			break;
> +		default:
> +			break;
> +		}
> 
> -	/* Verify user input. */
> -	for (i = 0; i < IGB_RETA_SIZE; i++)
> -		if (rxfh->indir[i] >= num_queues)
> -			return -EINVAL;
> +		/* Verify user input. */
> +		for (i = 0; i < IGB_RETA_SIZE; i++)
> +			if (rxfh->indir[i] >= num_queues)
> +				return -EINVAL;
> 
> 
> -	for (i = 0; i < IGB_RETA_SIZE; i++)
> -		adapter->rss_indir_tbl[i] = rxfh->indir[i];
> +		for (i = 0; i < IGB_RETA_SIZE; i++)
> +			adapter->rss_indir_tbl[i] = rxfh->indir[i];
> +
> +		igb_write_rss_indir_tbl(adapter);
> +	}
> 
> -	igb_write_rss_indir_tbl(adapter);
> +	if (rxfh->key) {
> +		adapter->has_user_rss_key = true;
> +		memcpy(adapter->rss_key, rxfh->key, sizeof(adapter-
> >rss_key));
> +		igb_write_rss_key(adapter);
> +	}
> 
>  	return 0;
>  }
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c
> b/drivers/net/ethernet/intel/igb/igb_main.c
> index da0f550de605..d42b3750f0b1 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -4526,7 +4526,8 @@ static void igb_setup_mrqc(struct igb_adapter
> *adapter)
>  	u32 mrqc, rxcsum;
>  	u32 j, num_rx_queues;
> 
> -	netdev_rss_key_fill(adapter->rss_key, sizeof(adapter-
> >rss_key));
> +	if (!adapter->has_user_rss_key)
> +		netdev_rss_key_fill(adapter->rss_key, sizeof(adapter-
> >rss_key));
>  	igb_write_rss_key(adapter);
> 
>  	num_rx_queues = adapter->rss_queues;
> --
> 2.51.1