[PATCH iwl-next v1 0/3] igc: add RSS key get/set support

[PATCH iwl-next v1 0/3] igc: add RSS key get/set support

[Kohei Enju]

This series adds ethtool get/set support for the RSS hash key in the igc
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 be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef
 Cannot set RX flow hash configuration:
  Hash key setting not supported

With patch:
 # ethtool -x $DEV | grep key -A1
 RSS hash key:
 dd:7c:1f:06:1a:42:dc:e5:7e:90:2c:48:aa:3f:5d:5a:d7:da:ec:44:3e:3f:df:78:89:1e:3c:68:2e:59:da:a0:23:5a:32:5c:cf:5e:7e:7b
 # ethtool -X $DEV hkey be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef
 # ethtool -x $DEV | grep key -A1
 RSS hash key:
 be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef:be:ef

Kohei Enju (3):
  igc: prepare for RSS key get/set support
  igc: expose RSS key via ethtool get_rxfh
  igc: allow configuring RSS key via ethtool set_rxfh

 drivers/net/ethernet/intel/igc/igc.h         |  4 ++
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 60 ++++++++++++++------
 drivers/net/ethernet/intel/igc/igc_main.c    |  7 +--
 3 files changed, 50 insertions(+), 21 deletions(-)

-- 
2.51.0

[PATCH iwl-next v1 1/3] igc: prepare for RSS key get/set support

[Kohei Enju]

Store the RSS key inside struct igc_adapter and introduce the
igc_write_rss_key() helper function. This allows the driver to program
the RSSRK registers using a persistent RSS key, instead of using a
stack-local buffer in igc_setup_mrqc().

This is a preparation patch for adding RSS key get/set support in
subsequent changes, and no functional change is intended in this patch.

Signed-off-by: Kohei Enju <enjuk@amazon.com>
---
 drivers/net/ethernet/intel/igc/igc.h         |  3 +++
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 12 ++++++++++++
 drivers/net/ethernet/intel/igc/igc_main.c    |  6 ++----
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index a427f05814c1..dd159397d191 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -30,6 +30,7 @@ void igc_ethtool_set_ops(struct net_device *);
 
 #define MAX_ETYPE_FILTER		8
 #define IGC_RETA_SIZE			128
+#define IGC_RSS_KEY_SIZE		40
 
 /* SDP support */
 #define IGC_N_EXTTS	2
@@ -302,6 +303,7 @@ struct igc_adapter {
 	unsigned int nfc_rule_count;
 
 	u8 rss_indir_tbl[IGC_RETA_SIZE];
+	u8 rss_key[IGC_RSS_KEY_SIZE];
 
 	unsigned long link_check_timeout;
 	struct igc_info ei;
@@ -360,6 +362,7 @@ unsigned int igc_get_max_rss_queues(struct igc_adapter *adapter);
 void igc_set_flag_queue_pairs(struct igc_adapter *adapter,
 			      const u32 max_rss_queues);
 int igc_reinit_queues(struct igc_adapter *adapter);
+void igc_write_rss_key(struct igc_adapter *adapter);
 void igc_write_rss_indir_tbl(struct igc_adapter *adapter);
 bool igc_has_link(struct igc_adapter *adapter);
 void igc_reset(struct igc_adapter *adapter);
diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index ca93629b1d3a..f89c2cbaace0 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1456,6 +1456,18 @@ static int igc_ethtool_set_rxnfc(struct net_device *dev,
 	}
 }
 
+void igc_write_rss_key(struct igc_adapter *adapter)
+{
+	struct igc_hw *hw = &adapter->hw;
+	u32 val;
+	int i;
+
+	for (i = 0; i < IGC_RSS_KEY_SIZE / 4; i++) {
+		val = get_unaligned_le32(&adapter->rss_key[i * 4]);
+		wr32(IGC_RSSRK(i), val);
+	}
+}
+
 void igc_write_rss_indir_tbl(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 728d7ca5338b..1f0a601cbcef 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -778,11 +778,9 @@ static void igc_setup_mrqc(struct igc_adapter *adapter)
 	struct igc_hw *hw = &adapter->hw;
 	u32 j, num_rx_queues;
 	u32 mrqc, rxcsum;
-	u32 rss_key[10];
 
-	netdev_rss_key_fill(rss_key, sizeof(rss_key));
-	for (j = 0; j < 10; j++)
-		wr32(IGC_RSSRK(j), rss_key[j]);
+	netdev_rss_key_fill(adapter->rss_key, sizeof(adapter->rss_key));
+	igc_write_rss_key(adapter);
 
 	num_rx_queues = adapter->rss_queues;
 
-- 
2.51.0

RE: [Intel-wired-lan] [PATCH iwl-next v1 1/3] igc: prepare for RSS key get/set support

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Kohei Enju
> Sent: Saturday, October 25, 2025 5:02 PM
> To: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org
> Cc: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; Andrew Lunn
> <andrew+netdev@lunn.ch>; David S. Miller <davem@davemloft.net>; Eric
> Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo
> Abeni <pabeni@redhat.com>; kohei.enju@gmail.com; Kohei Enju
> <enjuk@amazon.com>
> Subject: [Intel-wired-lan] [PATCH iwl-next v1 1/3] igc: prepare for
> RSS key get/set support
> 
> Store the RSS key inside struct igc_adapter and introduce the
> igc_write_rss_key() helper function. This allows the driver to program
> the RSSRK registers using a persistent RSS key, instead of using a
> stack-local buffer in igc_setup_mrqc().
> 
> This is a preparation patch for adding RSS key get/set support in
> subsequent changes, and no functional change is intended in this
> patch.
> 
> Signed-off-by: Kohei Enju <enjuk@amazon.com>
> ---
>  drivers/net/ethernet/intel/igc/igc.h         |  3 +++
>  drivers/net/ethernet/intel/igc/igc_ethtool.c | 12 ++++++++++++
>  drivers/net/ethernet/intel/igc/igc_main.c    |  6 ++----
>  3 files changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc.h
> b/drivers/net/ethernet/intel/igc/igc.h
> index a427f05814c1..dd159397d191 100644
> --- a/drivers/net/ethernet/intel/igc/igc.h
> +++ b/drivers/net/ethernet/intel/igc/igc.h
> @@ -30,6 +30,7 @@ void igc_ethtool_set_ops(struct net_device *);
> 
>  #define MAX_ETYPE_FILTER		8
>  #define IGC_RETA_SIZE			128
> +#define IGC_RSS_KEY_SIZE		40
> 
>  /* SDP support */
>  #define IGC_N_EXTTS	2
> @@ -302,6 +303,7 @@ struct igc_adapter {
>  	unsigned int nfc_rule_count;
> 
>  	u8 rss_indir_tbl[IGC_RETA_SIZE];
> +	u8 rss_key[IGC_RSS_KEY_SIZE];
> 
>  	unsigned long link_check_timeout;
>  	struct igc_info ei;
> @@ -360,6 +362,7 @@ unsigned int igc_get_max_rss_queues(struct
> igc_adapter *adapter);  void igc_set_flag_queue_pairs(struct
> igc_adapter *adapter,
>  			      const u32 max_rss_queues);
>  int igc_reinit_queues(struct igc_adapter *adapter);
> +void igc_write_rss_key(struct igc_adapter *adapter);
>  void igc_write_rss_indir_tbl(struct igc_adapter *adapter);  bool
> igc_has_link(struct igc_adapter *adapter);  void igc_reset(struct
> igc_adapter *adapter); diff --git
> a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> index ca93629b1d3a..f89c2cbaace0 100644
> --- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> +++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> @@ -1456,6 +1456,18 @@ static int igc_ethtool_set_rxnfc(struct
> net_device *dev,
>  	}
>  }
> 
> +void igc_write_rss_key(struct igc_adapter *adapter) {
> +	struct igc_hw *hw = &adapter->hw;
> +	u32 val;
> +	int i;
> +
> +	for (i = 0; i < IGC_RSS_KEY_SIZE / 4; i++) {
> +		val = get_unaligned_le32(&adapter->rss_key[i * 4]);
> +		wr32(IGC_RSSRK(i), val);
> +	}
> +}
> +
>  void igc_write_rss_indir_tbl(struct igc_adapter *adapter)  {
>  	struct igc_hw *hw = &adapter->hw;
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
> b/drivers/net/ethernet/intel/igc/igc_main.c
> index 728d7ca5338b..1f0a601cbcef 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -778,11 +778,9 @@ static void igc_setup_mrqc(struct igc_adapter
> *adapter)
>  	struct igc_hw *hw = &adapter->hw;
>  	u32 j, num_rx_queues;
>  	u32 mrqc, rxcsum;
> -	u32 rss_key[10];
> 
> -	netdev_rss_key_fill(rss_key, sizeof(rss_key));
> -	for (j = 0; j < 10; j++)
> -		wr32(IGC_RSSRK(j), rss_key[j]);
> +	netdev_rss_key_fill(adapter->rss_key, sizeof(adapter-
> >rss_key));
> +	igc_write_rss_key(adapter);
> 
>  	num_rx_queues = adapter->rss_queues;
> 
> --
> 2.51.0

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

Re: [PATCH iwl-next v1 1/3] igc: prepare for RSS key get/set support

[Simon Horman]

On Sun, Oct 26, 2025 at 12:01:30AM +0900, Kohei Enju wrote:
> Store the RSS key inside struct igc_adapter and introduce the
> igc_write_rss_key() helper function. This allows the driver to program
> the RSSRK registers using a persistent RSS key, instead of using a
> stack-local buffer in igc_setup_mrqc().
> 
> This is a preparation patch for adding RSS key get/set support in
> subsequent changes, and no functional change is intended in this patch.
> 
> Signed-off-by: Kohei Enju <enjuk@amazon.com>

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [Intel-wired-lan] [PATCH iwl-next v1 1/3] igc: prepare for RSS key get/set support

[Lifshits, Vitaly]

On 10/28/2025 8:12 PM, Simon Horman wrote:
> On Sun, Oct 26, 2025 at 12:01:30AM +0900, Kohei Enju wrote:
>> Store the RSS key inside struct igc_adapter and introduce the
>> igc_write_rss_key() helper function. This allows the driver to program
>> the RSSRK registers using a persistent RSS key, instead of using a
>> stack-local buffer in igc_setup_mrqc().
>>
>> This is a preparation patch for adding RSS key get/set support in
>> subsequent changes, and no functional change is intended in this patch.
>>
>> Signed-off-by: Kohei Enju <enjuk@amazon.com>
> 
> Reviewed-by: Simon Horman <horms@kernel.org>
> 

Reviewed-by: Vitaly Lifshits <vitaly.lifshits@intel.com>

Re: [Intel-wired-lan] [PATCH iwl-next v1 1/3] igc: prepare for RSS key get/set support

[Avigail Dahan]

On 25/10/2025 18:01, Kohei Enju wrote:
> Store the RSS key inside struct igc_adapter and introduce the
> igc_write_rss_key() helper function. This allows the driver to program
> the RSSRK registers using a persistent RSS key, instead of using a
> stack-local buffer in igc_setup_mrqc().
> 
> This is a preparation patch for adding RSS key get/set support in
> subsequent changes, and no functional change is intended in this patch.
> 
> Signed-off-by: Kohei Enju <enjuk@amazon.com>
> ---
>   drivers/net/ethernet/intel/igc/igc.h         |  3 +++
>   drivers/net/ethernet/intel/igc/igc_ethtool.c | 12 ++++++++++++
>   drivers/net/ethernet/intel/igc/igc_main.c    |  6 ++----
>   3 files changed, 17 insertions(+), 4 deletions(-)
> 

Tested-by: Avigail Dahan <avigailx.dahan@intel.com>

[PATCH iwl-next v1 2/3] igc: expose RSS key via ethtool get_rxfh

[Kohei Enju]

Implement igc_ethtool_get_rxfh_key_size() and extend
igc_ethtool_get_rxfh() to return the RSS key to userspace.

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

Signed-off-by: Kohei Enju <enjuk@amazon.com>
---
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index f89c2cbaace0..0482e590bc5a 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1490,6 +1490,11 @@ void igc_write_rss_indir_tbl(struct igc_adapter *adapter)
 	}
 }
 
+static u32 igc_ethtool_get_rxfh_key_size(struct net_device *netdev)
+{
+	return IGC_RSS_KEY_SIZE;
+}
+
 static u32 igc_ethtool_get_rxfh_indir_size(struct net_device *netdev)
 {
 	return IGC_RETA_SIZE;
@@ -1502,10 +1507,13 @@ static int igc_ethtool_get_rxfh(struct net_device *netdev,
 	int i;
 
 	rxfh->hfunc = ETH_RSS_HASH_TOP;
-	if (!rxfh->indir)
-		return 0;
-	for (i = 0; i < IGC_RETA_SIZE; i++)
-		rxfh->indir[i] = adapter->rss_indir_tbl[i];
+
+	if (rxfh->indir)
+		for (i = 0; i < IGC_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;
 }
@@ -2182,6 +2190,7 @@ static const struct ethtool_ops igc_ethtool_ops = {
 	.set_coalesce		= igc_ethtool_set_coalesce,
 	.get_rxnfc		= igc_ethtool_get_rxnfc,
 	.set_rxnfc		= igc_ethtool_set_rxnfc,
+	.get_rxfh_key_size	= igc_ethtool_get_rxfh_key_size,
 	.get_rxfh_indir_size	= igc_ethtool_get_rxfh_indir_size,
 	.get_rxfh		= igc_ethtool_get_rxfh,
 	.set_rxfh		= igc_ethtool_set_rxfh,
-- 
2.51.0

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

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Kohei Enju
> Sent: Saturday, October 25, 2025 5:02 PM
> To: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org
> Cc: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; Andrew Lunn
> <andrew+netdev@lunn.ch>; David S. Miller <davem@davemloft.net>; Eric
> Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo
> Abeni <pabeni@redhat.com>; kohei.enju@gmail.com; Kohei Enju
> <enjuk@amazon.com>
> Subject: [Intel-wired-lan] [PATCH iwl-next v1 2/3] igc: expose RSS key
> via ethtool get_rxfh
> 
> Implement igc_ethtool_get_rxfh_key_size() and extend
> igc_ethtool_get_rxfh() to return the RSS key to userspace.
> 
> This can be tested using `ethtool -x <dev>`.
> 
> Signed-off-by: Kohei Enju <enjuk@amazon.com>
> ---
>  drivers/net/ethernet/intel/igc/igc_ethtool.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> index f89c2cbaace0..0482e590bc5a 100644
> --- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> +++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> @@ -1490,6 +1490,11 @@ void igc_write_rss_indir_tbl(struct igc_adapter
> *adapter)
>  	}
>  }
> 
> +static u32 igc_ethtool_get_rxfh_key_size(struct net_device *netdev) {
> +	return IGC_RSS_KEY_SIZE;
> +}
> +
>  static u32 igc_ethtool_get_rxfh_indir_size(struct net_device *netdev)
> {
>  	return IGC_RETA_SIZE;
> @@ -1502,10 +1507,13 @@ static int igc_ethtool_get_rxfh(struct
> net_device *netdev,
>  	int i;
> 
>  	rxfh->hfunc = ETH_RSS_HASH_TOP;
> -	if (!rxfh->indir)
> -		return 0;
> -	for (i = 0; i < IGC_RETA_SIZE; i++)
> -		rxfh->indir[i] = adapter->rss_indir_tbl[i];
> +
> +	if (rxfh->indir)
> +		for (i = 0; i < IGC_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;
>  }
> @@ -2182,6 +2190,7 @@ static const struct ethtool_ops igc_ethtool_ops
> = {
>  	.set_coalesce		= igc_ethtool_set_coalesce,
>  	.get_rxnfc		= igc_ethtool_get_rxnfc,
>  	.set_rxnfc		= igc_ethtool_set_rxnfc,
> +	.get_rxfh_key_size	= igc_ethtool_get_rxfh_key_size,
>  	.get_rxfh_indir_size	= igc_ethtool_get_rxfh_indir_size,
>  	.get_rxfh		= igc_ethtool_get_rxfh,
>  	.set_rxfh		= igc_ethtool_set_rxfh,
> --
> 2.51.0

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

Re: [PATCH iwl-next v1 2/3] igc: expose RSS key via ethtool get_rxfh

[Simon Horman]

On Sun, Oct 26, 2025 at 12:01:31AM +0900, Kohei Enju wrote:
> Implement igc_ethtool_get_rxfh_key_size() and extend
> igc_ethtool_get_rxfh() to return the RSS key to userspace.
> 
> This can be tested using `ethtool -x <dev>`.
> 
> Signed-off-by: Kohei Enju <enjuk@amazon.com>

Reviewed-by: Simon Horman <horms@kernel.org>

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

[Lifshits, Vitaly]

On 10/28/2025 8:12 PM, Simon Horman wrote:
> On Sun, Oct 26, 2025 at 12:01:31AM +0900, Kohei Enju wrote:
>> Implement igc_ethtool_get_rxfh_key_size() and extend
>> igc_ethtool_get_rxfh() to return the RSS key to userspace.
>>
>> This can be tested using `ethtool -x <dev>`.
>>
>> Signed-off-by: Kohei Enju <enjuk@amazon.com>
> 
> Reviewed-by: Simon Horman <horms@kernel.org>
> 

Reviewed-by: Vitaly Lifshits <vitaly.lifshits@intel.com>

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

[Avigail Dahan]

On 25/10/2025 18:01, Kohei Enju wrote:
> Implement igc_ethtool_get_rxfh_key_size() and extend
> igc_ethtool_get_rxfh() to return the RSS key to userspace.
> 
> This can be tested using `ethtool -x <dev>`.
> 
> Signed-off-by: Kohei Enju <enjuk@amazon.com>
> ---
>   drivers/net/ethernet/intel/igc/igc_ethtool.c | 17 +++++++++++++----
>   1 file changed, 13 insertions(+), 4 deletions(-)
> 

Tested-by: Avigail Dahan <avigailx.dahan@intel.com>

[PATCH iwl-next v1 3/3] igc: allow configuring RSS key via ethtool set_rxfh

[Kohei Enju]

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

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

Signed-off-by: Kohei Enju <enjuk@amazon.com>
---
 drivers/net/ethernet/intel/igc/igc.h         |  1 +
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 31 ++++++++++++--------
 drivers/net/ethernet/intel/igc/igc_main.c    |  3 +-
 3 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index dd159397d191..c894a5a99fc0 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -304,6 +304,7 @@ struct igc_adapter {
 
 	u8 rss_indir_tbl[IGC_RETA_SIZE];
 	u8 rss_key[IGC_RSS_KEY_SIZE];
+	bool has_user_rss_key;
 
 	unsigned long link_check_timeout;
 	struct igc_info ei;
diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index 0482e590bc5a..64eac1ccb3ff 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1527,24 +1527,29 @@ static int igc_ethtool_set_rxfh(struct net_device *netdev,
 	int i;
 
 	/* 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;
 
-	/* Verify user input. */
-	for (i = 0; i < IGC_RETA_SIZE; i++)
-		if (rxfh->indir[i] >= num_queues)
-			return -EINVAL;
+		/* Verify user input. */
+		for (i = 0; i < IGC_RETA_SIZE; i++)
+			if (rxfh->indir[i] >= num_queues)
+				return -EINVAL;
 
-	for (i = 0; i < IGC_RETA_SIZE; i++)
-		adapter->rss_indir_tbl[i] = rxfh->indir[i];
+		for (i = 0; i < IGC_RETA_SIZE; i++)
+			adapter->rss_indir_tbl[i] = rxfh->indir[i];
 
-	igc_write_rss_indir_tbl(adapter);
+		igc_write_rss_indir_tbl(adapter);
+	}
+
+	if (rxfh->key) {
+		adapter->has_user_rss_key = true;
+		memcpy(adapter->rss_key, rxfh->key, sizeof(adapter->rss_key));
+		igc_write_rss_key(adapter);
+	}
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 1f0a601cbcef..e977661bed2f 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -779,7 +779,8 @@ static void igc_setup_mrqc(struct igc_adapter *adapter)
 	u32 j, num_rx_queues;
 	u32 mrqc, rxcsum;
 
-	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));
 	igc_write_rss_key(adapter);
 
 	num_rx_queues = adapter->rss_queues;
-- 
2.51.0

RE: [Intel-wired-lan] [PATCH iwl-next v1 3/3] igc: 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 Kohei Enju
> Sent: Saturday, October 25, 2025 5:02 PM
> To: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org
> Cc: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; Andrew Lunn
> <andrew+netdev@lunn.ch>; David S. Miller <davem@davemloft.net>; Eric
> Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo
> Abeni <pabeni@redhat.com>; kohei.enju@gmail.com; Kohei Enju
> <enjuk@amazon.com>
> Subject: [Intel-wired-lan] [PATCH iwl-next v1 3/3] igc: allow
> configuring RSS key via ethtool set_rxfh
> 
> Change igc_ethtool_set_rxfh() to accept and save a userspace-provided
> RSS key. When a key is provided, store it in the adapter and write the
> RSSRK registers accordingly.
> 
> This can be tested using `ethtool -X <dev> hkey <key>`.
> 
> Signed-off-by: Kohei Enju <enjuk@amazon.com>
> ---
>  drivers/net/ethernet/intel/igc/igc.h         |  1 +
>  drivers/net/ethernet/intel/igc/igc_ethtool.c | 31 ++++++++++++-------
> -
>  drivers/net/ethernet/intel/igc/igc_main.c    |  3 +-
>  3 files changed, 21 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc.h
> b/drivers/net/ethernet/intel/igc/igc.h
> index dd159397d191..c894a5a99fc0 100644
> --- a/drivers/net/ethernet/intel/igc/igc.h
> +++ b/drivers/net/ethernet/intel/igc/igc.h
> @@ -304,6 +304,7 @@ struct igc_adapter {
> 
>  	u8 rss_indir_tbl[IGC_RETA_SIZE];
>  	u8 rss_key[IGC_RSS_KEY_SIZE];
> +	bool has_user_rss_key;
> 
>  	unsigned long link_check_timeout;
>  	struct igc_info ei;
> diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> index 0482e590bc5a..64eac1ccb3ff 100644
> --- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> +++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> @@ -1527,24 +1527,29 @@ static int igc_ethtool_set_rxfh(struct
> net_device *netdev,
>  	int i;
> 
>  	/* 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;
> 
> -	/* Verify user input. */
> -	for (i = 0; i < IGC_RETA_SIZE; i++)
> -		if (rxfh->indir[i] >= num_queues)
> -			return -EINVAL;
> +		/* Verify user input. */
> +		for (i = 0; i < IGC_RETA_SIZE; i++)
> +			if (rxfh->indir[i] >= num_queues)
> +				return -EINVAL;
> 
> -	for (i = 0; i < IGC_RETA_SIZE; i++)
> -		adapter->rss_indir_tbl[i] = rxfh->indir[i];
> +		for (i = 0; i < IGC_RETA_SIZE; i++)
> +			adapter->rss_indir_tbl[i] = rxfh->indir[i];
> 
> -	igc_write_rss_indir_tbl(adapter);
> +		igc_write_rss_indir_tbl(adapter);
> +	}
> +
> +	if (rxfh->key) {
> +		adapter->has_user_rss_key = true;
> +		memcpy(adapter->rss_key, rxfh->key, sizeof(adapter-
> >rss_key));
> +		igc_write_rss_key(adapter);
> +	}
> 
>  	return 0;
>  }
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
> b/drivers/net/ethernet/intel/igc/igc_main.c
> index 1f0a601cbcef..e977661bed2f 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -779,7 +779,8 @@ static void igc_setup_mrqc(struct igc_adapter
> *adapter)
>  	u32 j, num_rx_queues;
>  	u32 mrqc, rxcsum;
> 
> -	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));
>  	igc_write_rss_key(adapter);
> 
>  	num_rx_queues = adapter->rss_queues;
> --
> 2.51.0

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

Re: [PATCH iwl-next v1 3/3] igc: allow configuring RSS key via ethtool set_rxfh

[Simon Horman]

On Sun, Oct 26, 2025 at 12:01:32AM +0900, Kohei Enju wrote:
> Change igc_ethtool_set_rxfh() to accept and save a userspace-provided
> RSS key. When a key is provided, store it in the adapter and write the
> RSSRK registers accordingly.
> 
> This can be tested using `ethtool -X <dev> hkey <key>`.
> 
> Signed-off-by: Kohei Enju <enjuk@amazon.com>

Reviewed-by: Simon Horman <horms@kernel.org>

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

[Lifshits, Vitaly]

On 10/28/2025 8:12 PM, Simon Horman wrote:
> On Sun, Oct 26, 2025 at 12:01:32AM +0900, Kohei Enju wrote:
>> Change igc_ethtool_set_rxfh() to accept and save a userspace-provided
>> RSS key. When a key is provided, store it in the adapter and write the
>> RSSRK registers accordingly.
>>
>> This can be tested using `ethtool -X <dev> hkey <key>`.
>>
>> Signed-off-by: Kohei Enju <enjuk@amazon.com>
> 
> Reviewed-by: Simon Horman <horms@kernel.org>
> 

Reviewed-by: Vitaly Lifshits <vitaly.lifshits@intel.com>

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

[Avigail Dahan]

On 25/10/2025 18:01, Kohei Enju wrote:
> Change igc_ethtool_set_rxfh() to accept and save a userspace-provided
> RSS key. When a key is provided, store it in the adapter and write the
> RSSRK registers accordingly.
> 
> This can be tested using `ethtool -X <dev> hkey <key>`.
> 
> Signed-off-by: Kohei Enju <enjuk@amazon.com>
> ---
>   drivers/net/ethernet/intel/igc/igc.h         |  1 +
>   drivers/net/ethernet/intel/igc/igc_ethtool.c | 31 ++++++++++++--------
>   drivers/net/ethernet/intel/igc/igc_main.c    |  3 +-
>   3 files changed, 21 insertions(+), 14 deletions(-)
> 

Tested-by: Avigail Dahan <avigailx.dahan@intel.com>