[PATCH v2 iwl-next 0/3] igc: add RSS key get/set support

[PATCH v2 iwl-next 0/3] igc: add RSS key get/set support

[Kohei Enju]

This series adds ethtool get/set support for the RSS hash 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

Also tested with rss_api.py and toeplitz.py.
 # ./tools/testing/selftests/drivers/net/hw/rss_api.py | grep rss_api.test_rxfh_nl_set_key
 ok 6 rss_api.test_rxfh_nl_set_key
 # tools/testing/selftests/drivers/net/hw/toeplitz.py | grep "# Totals"
 # Totals: pass:12 fail:0 xfail:0 xpass:0 skip:0 error:0

Notes:
Since the 2/3 patch is unchanged, I preserved Tested-by and Reviewed-by
tags for the patch.

Changes:
  v2:
    - call netdev_rss_key_fill() in igc_sw_init(), not in
      igc_setup_mrqc()
    - add documentation for igc_write_rss_key()
    - drop has_user_rss_key flag, since rss_key is never cleared except
      for user operations
    - change email address from @amazon.com to @enjuk.jp
  v1: https://lore.kernel.org/intel-wired-lan/20251025150136.47618-1-enjuk@amazon.com/

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         |  3 +
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 67 +++++++++++++++-----
 drivers/net/ethernet/intel/igc/igc_main.c    |  8 +--
 3 files changed, 57 insertions(+), 21 deletions(-)

-- 
2.51.0

[PATCH v2 iwl-next 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 <kohei@enjuk.jp>
---
 drivers/net/ethernet/intel/igc/igc.h         |  3 +++
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 20 ++++++++++++++++++++
 drivers/net/ethernet/intel/igc/igc_main.c    |  8 ++++----
 3 files changed, 27 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 3172cdbca9cc..1b4075e7e8e6 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1460,6 +1460,26 @@ static int igc_ethtool_set_rxnfc(struct net_device *dev,
 	}
 }
 
+/**
+ * igc_write_rss_key - Program the RSS key into device registers
+ * @adapter: board private structure
+ *
+ * Write the RSS key stored in adapter->rss_key to the IGC_RSSRK registers.
+ * Each 32-bit chunk of the key is read using get_unaligned_le32() and written
+ * to the appropriate register.
+ */
+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 89a321a344d2..98410f9d7828 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -778,11 +778,8 @@ 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]);
+	igc_write_rss_key(adapter);
 
 	num_rx_queues = adapter->rss_queues;
 
@@ -5046,6 +5043,9 @@ static int igc_sw_init(struct igc_adapter *adapter)
 
 	pci_read_config_word(pdev, PCI_COMMAND, &hw->bus.pci_cmd_word);
 
+	/* init RSS key */
+	netdev_rss_key_fill(adapter->rss_key, sizeof(adapter->rss_key));
+
 	/* set default ring sizes */
 	adapter->tx_ring_count = IGC_DEFAULT_TXD;
 	adapter->rx_ring_count = IGC_DEFAULT_RXD;
-- 
2.51.0

RE: [PATCH v2 iwl-next 1/3] igc: prepare for RSS key get/set support

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Kohei Enju <kohei@enjuk.jp>
> Sent: Saturday, January 31, 2026 5:30 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>; Lifshits, Vitaly
> <vitaly.lifshits@intel.com>; Simon Horman <horms@kernel.org>;
> Loktionov, Aleksandr <aleksandr.loktionov@intel.com>;
> kohei.enju@gmail.com; Kohei Enju <kohei@enjuk.jp>
> Subject: [PATCH v2 iwl-next 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 <kohei@enjuk.jp>
> ---
>  drivers/net/ethernet/intel/igc/igc.h         |  3 +++
>  drivers/net/ethernet/intel/igc/igc_ethtool.c | 20
> ++++++++++++++++++++
>  drivers/net/ethernet/intel/igc/igc_main.c    |  8 ++++----
>  3 files changed, 27 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 3172cdbca9cc..1b4075e7e8e6 100644
> --- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> +++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
I think here should be added include?

#include <linux/unaligned.h> /* for get_unaligned_le32() */

Isn't it?

> @@ -1460,6 +1460,26 @@ static int igc_ethtool_set_rxnfc(struct
> net_device *dev,
>  	}
>  }
> 
> +/**
> + * igc_write_rss_key - Program the RSS key into device registers
> + * @adapter: board private structure
> + *
> + * Write the RSS key stored in adapter->rss_key to the IGC_RSSRK
> registers.
> + * Each 32-bit chunk of the key is read using get_unaligned_le32()
> and
> +written
> + * to the appropriate register.
> + */
> +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);
> +	}
> +}
> +

...

> --
> 2.51.0

Re: [PATCH v2 iwl-next 1/3] igc: prepare for RSS key get/set support

[Kohei Enju]

On Mon, 2 Feb 2026 07:59:55 +0000, "Loktionov, Aleksandr" wrote:

> > @@ -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 3172cdbca9cc..1b4075e7e8e6 100644
> > --- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> > +++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> I think here should be added include?
> 
> #include <linux/unaligned.h> /* for get_unaligned_le32() */
> 
> Isn't it?

Hi Alex, thank you for reviewing.

Compilation succeeds as is, and the header file is included indirectly
in the following path.

igc_ethtool.c
  -> linux/if_vlan.h
    -> linux/etherdevice.h
      -> linux/unaligned.h

> 
> > @@ -1460,6 +1460,26 @@ static int igc_ethtool_set_rxnfc(struct
> > net_device *dev,
> >  	}
> >  }
> >=20
> > +/**
> > + * igc_write_rss_key - Program the RSS key into device registers
> > + * @adapter: board private structure
> > + *
> > + * Write the RSS key stored in adapter->rss_key to the IGC_RSSRK
> > registers.
> > + * Each 32-bit chunk of the key is read using get_unaligned_le32()
> > and
> > +written
> > + * to the appropriate register.
> > + */
> > +void igc_write_rss_key(struct igc_adapter *adapter) {
> > +	struct igc_hw *hw =3D &adapter->hw;
> > +	u32 val;
> > +	int i;
> > +
> > +	for (i =3D 0; i < IGC_RSS_KEY_SIZE / 4; i++) {
> > +		val =3D get_unaligned_le32(&adapter->rss_key[i * 4]);
> > +		wr32(IGC_RSSRK(i), val);
> > +	}
> > +}
> > +
> 
> ...
> 
> > --
> > 2.51.0

RE: [PATCH v2 iwl-next 1/3] igc: prepare for RSS key get/set support

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Kohei Enju <kohei@enjuk.jp>
> Sent: Monday, February 2, 2026 10:06 AM
> To: Loktionov, Aleksandr <aleksandr.loktionov@intel.com>
> Cc: andrew+netdev@lunn.ch; Nguyen, Anthony L
> <anthony.l.nguyen@intel.com>; davem@davemloft.net;
> edumazet@google.com; horms@kernel.org; intel-wired-
> lan@lists.osuosl.org; kohei.enju@gmail.com; kohei@enjuk.jp;
> kuba@kernel.org; netdev@vger.kernel.org; pabeni@redhat.com; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; Lifshits, Vitaly
> <vitaly.lifshits@intel.com>
> Subject: Re: [PATCH v2 iwl-next 1/3] igc: prepare for RSS key get/set
> support
> 
> On Mon, 2 Feb 2026 07:59:55 +0000, "Loktionov, Aleksandr" wrote:
> 
> > > @@ -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 3172cdbca9cc..1b4075e7e8e6 100644
> > > --- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> > > +++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> > I think here should be added include?
> >
> > #include <linux/unaligned.h> /* for get_unaligned_le32() */
> >
> > Isn't it?
> 
> Hi Alex, thank you for reviewing.
> 
> Compilation succeeds as is, and the header file is included indirectly
> in the following path.
> 
> igc_ethtool.c
>   -> linux/if_vlan.h
>     -> linux/etherdevice.h
>       -> linux/unaligned.h
> 
> >
> > > @@ -1460,6 +1460,26 @@ static int igc_ethtool_set_rxnfc(struct
> > >net_device *dev,
> > >  	}
> > >  }
> > >=20
> > > +/**
> > > + * igc_write_rss_key - Program the RSS key into device registers
> > > + * @adapter: board private structure
> > > + *
> > > + * Write the RSS key stored in adapter->rss_key to the IGC_RSSRK
> > > registers.
> > > + * Each 32-bit chunk of the key is read using
> get_unaligned_le32()
> > > and
> > > +written
> > > + * to the appropriate register.
> > > + */
> > > +void igc_write_rss_key(struct igc_adapter *adapter) {
> > > +	struct igc_hw *hw =3D &adapter->hw;
> > > +	u32 val;
> > > +	int i;
> > > +
> > > +	for (i =3D 0; i < IGC_RSS_KEY_SIZE / 4; i++) {
> > > +		val =3D get_unaligned_le32(&adapter->rss_key[i * 4]);
> > > +		wr32(IGC_RSSRK(i), val);
> > > +	}
> > > +}
> > > +
> >
> > ...
> >
> > > --
> > > 2.51.0

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

Re: [Intel-wired-lan] [PATCH v2 iwl-next 1/3] igc: prepare for RSS key get/set support

[Dahan, AvigailX]

On 02/02/2026 9:59, Loktionov, Aleksandr wrote:
> 
> 
>> -----Original Message-----
>> From: Kohei Enju <kohei@enjuk.jp>
>> Sent: Saturday, January 31, 2026 5:30 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>; Lifshits, Vitaly
>> <vitaly.lifshits@intel.com>; Simon Horman <horms@kernel.org>;
>> Loktionov, Aleksandr <aleksandr.loktionov@intel.com>;
>> kohei.enju@gmail.com; Kohei Enju <kohei@enjuk.jp>
>> Subject: [PATCH v2 iwl-next 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 <kohei@enjuk.jp>
>> ---
>>   drivers/net/ethernet/intel/igc/igc.h         |  3 +++
>>   drivers/net/ethernet/intel/igc/igc_ethtool.c | 20
>> ++++++++++++++++++++
>>   drivers/net/ethernet/intel/igc/igc_main.c    |  8 ++++----
>>   3 files changed, 27 insertions(+), 4 deletions(-)
>>

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

Re: [PATCH v2 iwl-next 1/3] igc: prepare for RSS key get/set support

[Simon Horman]

On Sat, Jan 31, 2026 at 04:29:36PM +0000, 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 <kohei@enjuk.jp>

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

[PATCH v2 iwl-next 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 <kohei@enjuk.jp>
Tested-by: Avigail Dahan <avigailx.dahan@intel.com>
Reviewed-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.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 1b4075e7e8e6..661b044073ca 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1502,6 +1502,11 @@ 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;
@@ -1514,10 +1519,13 @@ 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;
 }
@@ -2195,6 +2203,7 @@ static const struct ethtool_ops igc_ethtool_ops = {
 	.get_rxnfc		= igc_ethtool_get_rxnfc,
 	.set_rxnfc		= igc_ethtool_set_rxnfc,
 	.get_rx_ring_count	= igc_ethtool_get_rx_ring_count,
+	.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

[PATCH v2 iwl-next 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 <kohei@enjuk.jp>
---
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 30 +++++++++++---------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index 661b044073ca..eb5b146f6f10 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1539,24 +1539,28 @@ 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) {
+		memcpy(adapter->rss_key, rxfh->key, sizeof(adapter->rss_key));
+		igc_write_rss_key(adapter);
+	}
 
 	return 0;
 }
-- 
2.51.0

Re: [PATCH v2 iwl-next 3/3] igc: allow configuring RSS key via ethtool set_rxfh

[Simon Horman]

On Sat, Jan 31, 2026 at 04:29:38PM +0000, 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 <kohei@enjuk.jp>

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

Re: [Intel-wired-lan] [PATCH v2 iwl-next 3/3] igc: allow configuring RSS key via ethtool set_rxfh

[Dahan, AvigailX]

On 31/01/2026 18:29, 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 <kohei@enjuk.jp>
> ---
>   drivers/net/ethernet/intel/igc/igc_ethtool.c | 30 +++++++++++---------
>   1 file changed, 17 insertions(+), 13 deletions(-)
> 

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