[PATCH iwl-next,v3 0/2] igc: Add Default Queue Support

[PATCH iwl-next,v3 0/2] igc: Add Default Queue Support

[Song Yoong Siang]

This patch set introduces the support to configure "Default Queue" during runtime
by using ethtool's Network Flow Classification (NFC) wildcard rule approach.

v3:
  - separate macros relocation code that not related to wildcard rule to another patch (Brett)

V2: https://patchwork.ozlabs.org/project/intel-wired-lan/patch/20250619153738.2788568-1-yoong.siang.song@intel.com/
  - use Ethtool wildcard rule instead of extra uAPI (Jakub Kicinski & Jacob Keller)
  - combine MRQC register definitions into a single location (Kurt Kanzenbach)
  - use FIELD_PREP (Kurt Kanzenbach)
  - use RCT rule (Wojciech Drewek)
  - no need brackets for single line code (Wojciech Drewek)
  - use imperative mood in commit message (Marcin Szycik)
  - ensure igc_ prefix in function name (Marcin Szycik)

V1: https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20240730012212.775814-1-yoong.siang.song@intel.com/

Song Yoong Siang (2):
  igc: Relocate RSS field definitions to igc_defines.h
  igc: Add wildcard rule support to ethtool NFC using Default Queue

 drivers/net/ethernet/intel/igc/igc.h         | 15 ++++++-------
 drivers/net/ethernet/intel/igc/igc_defines.h |  4 ++++
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 18 ++++++++++++++++
 drivers/net/ethernet/intel/igc/igc_main.c    | 22 ++++++++++++++++++++
 4 files changed, 52 insertions(+), 7 deletions(-)

-- 
2.34.1

[PATCH iwl-next,v3 1/2] igc: Relocate RSS field definitions to igc_defines.h

[Song Yoong Siang]

Move the RSS field definitions related to IPv4 and IPv6 UDP from igc.h to
igc_defines.h to consolidate the RSS field definitions in a single header
file, improving code organization and maintainability.

This refactoring does not alter the functionality of the driver but
enhances the logical grouping of related constants

Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h         | 4 ----
 drivers/net/ethernet/intel/igc/igc_defines.h | 3 +++
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 1525ae25fd3e..0b35e593d5ee 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -406,10 +406,6 @@ extern char igc_driver_name[];
 #define IGC_FLAG_RSS_FIELD_IPV4_UDP	BIT(6)
 #define IGC_FLAG_RSS_FIELD_IPV6_UDP	BIT(7)
 
-#define IGC_MRQC_ENABLE_RSS_MQ		0x00000002
-#define IGC_MRQC_RSS_FIELD_IPV4_UDP	0x00400000
-#define IGC_MRQC_RSS_FIELD_IPV6_UDP	0x00800000
-
 /* RX-desc Write-Back format RSS Type's */
 enum igc_rss_type_num {
 	IGC_RSS_TYPE_NO_HASH		= 0,
diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index 86b346687196..d80254f2a278 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -383,11 +383,14 @@
 #define IGC_RXDEXT_STATERR_IPE		0x40000000
 #define IGC_RXDEXT_STATERR_RXE		0x80000000
 
+#define IGC_MRQC_ENABLE_RSS_MQ		0x00000002
 #define IGC_MRQC_RSS_FIELD_IPV4_TCP	0x00010000
 #define IGC_MRQC_RSS_FIELD_IPV4		0x00020000
 #define IGC_MRQC_RSS_FIELD_IPV6_TCP_EX	0x00040000
 #define IGC_MRQC_RSS_FIELD_IPV6		0x00100000
 #define IGC_MRQC_RSS_FIELD_IPV6_TCP	0x00200000
+#define IGC_MRQC_RSS_FIELD_IPV4_UDP	0x00400000
+#define IGC_MRQC_RSS_FIELD_IPV6_UDP	0x00800000
 
 /* Header split receive */
 #define IGC_RFCTL_IPV6_EX_DIS	0x00010000
-- 
2.34.1

RE: [Intel-wired-lan] [PATCH iwl-next, v3 1/2] igc: Relocate RSS field definitions to igc_defines.h

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Song Yoong Siang
> Sent: Friday, June 20, 2025 12:03 PM
> To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; David S . Miller
> <davem@davemloft.net>; Eric Dumazet <edumazet@google.com>; Jakub
> Kicinski <kuba@kernel.org>; Paolo Abeni <pabeni@redhat.com>; Richard
> Cochran <richardcochran@gmail.com>; Alexei Starovoitov
> <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>; Jesper
> Dangaard Brouer <hawk@kernel.org>; John Fastabend
> <john.fastabend@gmail.com>; Gomes, Vinicius
> <vinicius.gomes@intel.com>; Jonathan Corbet <corbet@lwn.net>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; Shinas Rasheed
> <srasheed@marvell.com>; Tian, Kevin <kevin.tian@intel.com>; Brett
> Creeley <brett.creeley@amd.com>; Blanco Alcaine, Hector
> <hector.blanco.alcaine@intel.com>; Hay, Joshua A
> <joshua.a.hay@intel.com>; Andrew Lunn <andrew+netdev@lunn.ch>; Keller,
> Jacob E <jacob.e.keller@intel.com>; Kurt Kanzenbach
> <kurt@linutronix.de>; Marcin Szycik <marcin.szycik@linux.intel.com>;
> Brett Creeley <bcreeley@amd.com>
> Cc: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH iwl-next, v3 1/2] igc: Relocate RSS
> field definitions to igc_defines.h
> 
> Move the RSS field definitions related to IPv4 and IPv6 UDP from igc.h
> to igc_defines.h to consolidate the RSS field definitions in a single
> header file, improving code organization and maintainability.
> 
> This refactoring does not alter the functionality of the driver but
> enhances the logical grouping of related constants
> 
> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
> Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
> ---
>  drivers/net/ethernet/intel/igc/igc.h         | 4 ----
>  drivers/net/ethernet/intel/igc/igc_defines.h | 3 +++
>  2 files changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc.h
> b/drivers/net/ethernet/intel/igc/igc.h
> index 1525ae25fd3e..0b35e593d5ee 100644
> --- a/drivers/net/ethernet/intel/igc/igc.h
> +++ b/drivers/net/ethernet/intel/igc/igc.h
> @@ -406,10 +406,6 @@ extern char igc_driver_name[];
>  #define IGC_FLAG_RSS_FIELD_IPV4_UDP	BIT(6)
>  #define IGC_FLAG_RSS_FIELD_IPV6_UDP	BIT(7)
> 
> -#define IGC_MRQC_ENABLE_RSS_MQ		0x00000002
> -#define IGC_MRQC_RSS_FIELD_IPV4_UDP	0x00400000
> -#define IGC_MRQC_RSS_FIELD_IPV6_UDP	0x00800000
> -
>  /* RX-desc Write-Back format RSS Type's */  enum igc_rss_type_num {
>  	IGC_RSS_TYPE_NO_HASH		= 0,
> diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h
> b/drivers/net/ethernet/intel/igc/igc_defines.h
> index 86b346687196..d80254f2a278 100644
> --- a/drivers/net/ethernet/intel/igc/igc_defines.h
> +++ b/drivers/net/ethernet/intel/igc/igc_defines.h
> @@ -383,11 +383,14 @@
>  #define IGC_RXDEXT_STATERR_IPE		0x40000000
>  #define IGC_RXDEXT_STATERR_RXE		0x80000000
> 
> +#define IGC_MRQC_ENABLE_RSS_MQ		0x00000002
>  #define IGC_MRQC_RSS_FIELD_IPV4_TCP	0x00010000
>  #define IGC_MRQC_RSS_FIELD_IPV4		0x00020000
>  #define IGC_MRQC_RSS_FIELD_IPV6_TCP_EX	0x00040000
>  #define IGC_MRQC_RSS_FIELD_IPV6		0x00100000
>  #define IGC_MRQC_RSS_FIELD_IPV6_TCP	0x00200000
> +#define IGC_MRQC_RSS_FIELD_IPV4_UDP	0x00400000
> +#define IGC_MRQC_RSS_FIELD_IPV6_UDP	0x00800000
> 
>  /* Header split receive */
>  #define IGC_RFCTL_IPV6_EX_DIS	0x00010000
> --
> 2.34.1

Re: [PATCH iwl-next,v3 1/2] igc: Relocate RSS field definitions to igc_defines.h

[Brett Creeley]

On 6/20/2025 3:02 AM, Song Yoong Siang wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> Move the RSS field definitions related to IPv4 and IPv6 UDP from igc.h to
> igc_defines.h to consolidate the RSS field definitions in a single header
> file, improving code organization and maintainability.
> 
> This refactoring does not alter the functionality of the driver but
> enhances the logical grouping of related constants
> 
> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
> Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
> ---
>   drivers/net/ethernet/intel/igc/igc.h         | 4 ----
>   drivers/net/ethernet/intel/igc/igc_defines.h | 3 +++
>   2 files changed, 3 insertions(+), 4 deletions(-)

LGTM.

Reviewed-by: Brett Creeley <brett.creeley@amd.com>

> 
> diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
> index 1525ae25fd3e..0b35e593d5ee 100644
> --- a/drivers/net/ethernet/intel/igc/igc.h
> +++ b/drivers/net/ethernet/intel/igc/igc.h
> @@ -406,10 +406,6 @@ extern char igc_driver_name[];
>   #define IGC_FLAG_RSS_FIELD_IPV4_UDP    BIT(6)
>   #define IGC_FLAG_RSS_FIELD_IPV6_UDP    BIT(7)
> 
> -#define IGC_MRQC_ENABLE_RSS_MQ         0x00000002
> -#define IGC_MRQC_RSS_FIELD_IPV4_UDP    0x00400000
> -#define IGC_MRQC_RSS_FIELD_IPV6_UDP    0x00800000
> -
>   /* RX-desc Write-Back format RSS Type's */
>   enum igc_rss_type_num {
>          IGC_RSS_TYPE_NO_HASH            = 0,
> diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
> index 86b346687196..d80254f2a278 100644
> --- a/drivers/net/ethernet/intel/igc/igc_defines.h
> +++ b/drivers/net/ethernet/intel/igc/igc_defines.h
> @@ -383,11 +383,14 @@
>   #define IGC_RXDEXT_STATERR_IPE         0x40000000
>   #define IGC_RXDEXT_STATERR_RXE         0x80000000
> 
> +#define IGC_MRQC_ENABLE_RSS_MQ         0x00000002
>   #define IGC_MRQC_RSS_FIELD_IPV4_TCP    0x00010000
>   #define IGC_MRQC_RSS_FIELD_IPV4                0x00020000
>   #define IGC_MRQC_RSS_FIELD_IPV6_TCP_EX 0x00040000
>   #define IGC_MRQC_RSS_FIELD_IPV6                0x00100000
>   #define IGC_MRQC_RSS_FIELD_IPV6_TCP    0x00200000
> +#define IGC_MRQC_RSS_FIELD_IPV4_UDP    0x00400000
> +#define IGC_MRQC_RSS_FIELD_IPV6_UDP    0x00800000
> 
>   /* Header split receive */
>   #define IGC_RFCTL_IPV6_EX_DIS  0x00010000
> --
> 2.34.1
> 

Re: [Intel-wired-lan] [PATCH iwl-next, v3 1/2] igc: Relocate RSS field definitions to igc_defines.h

[Mor Bar-Gabay]

On 20/06/2025 13:02, Song Yoong Siang wrote:
> Move the RSS field definitions related to IPv4 and IPv6 UDP from igc.h to
> igc_defines.h to consolidate the RSS field definitions in a single header
> file, improving code organization and maintainability.
> 
> This refactoring does not alter the functionality of the driver but
> enhances the logical grouping of related constants
> 
> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
> Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
> Reviewed-by: Brett Creeley <brett.creeley@amd.com>
> ---
>   drivers/net/ethernet/intel/igc/igc.h         | 4 ----
>   drivers/net/ethernet/intel/igc/igc_defines.h | 3 +++
>   2 files changed, 3 insertions(+), 4 deletions(-)
> 
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>

[PATCH iwl-next,v3 2/2] igc: Add wildcard rule support to ethtool NFC using Default Queue

[Song Yoong Siang]

Introduce support for a lowest priority wildcard (catch-all) rule in
ethtool's Network Flow Classification (NFC) for the igc driver. The
wildcard rule directs all unmatched network traffic, including traffic not
captured by Receive Side Scaling (RSS), to a specified queue. This
functionality utilizes the Default Queue feature available in I225/I226
hardware.

The implementation has been validated on Intel ADL-S systems with two
back-to-back connected I226 network interfaces.

Testing Procedure:
1. On the Device Under Test (DUT), verify the initial statistic:
   $ ethtool -S enp1s0 | grep rx_q.*packets
        rx_queue_0_packets: 0
        rx_queue_1_packets: 0
        rx_queue_2_packets: 0
        rx_queue_3_packets: 0

2. From the Link Partner, send 10 ARP packets:
   $ arping -c 10 -I enp170s0 169.254.1.2

3. On the DUT, verify the packet reception on Queue 0:
   $ ethtool -S enp1s0 | grep rx_q.*packets
        rx_queue_0_packets: 10
        rx_queue_1_packets: 0
        rx_queue_2_packets: 0
        rx_queue_3_packets: 0

4. On the DUT, add a wildcard rule to route all packets to Queue 3:
   $ sudo ethtool -N enp1s0 flow-type ether queue 3

5. From the Link Partner, send another 10 ARP packets:
   $ arping -c 10 -I enp170s0 169.254.1.2

6. Now, packets are routed to Queue 3 by the wildcard (Default Queue) rule:
   $ ethtool -S enp1s0 | grep rx_q.*packets
        rx_queue_0_packets: 10
        rx_queue_1_packets: 0
        rx_queue_2_packets: 0
        rx_queue_3_packets: 10

7. On the DUT, add a EtherType rule to route ARP packet to Queue 1:
   $ sudo ethtool -N enp1s0 flow-type ether proto 0x0806 queue 1

8. From the Link Partner, send another 10 ARP packets:
   $ arping -c 10 -I enp170s0 169.254.1.2

9. Now, packets are routed to Queue 1 by the EtherType rule because it is
   higher priority than the wildcard (Default Queue) rule:
   $ ethtool -S enp1s0 | grep rx_q.*packets
        rx_queue_0_packets: 10
        rx_queue_1_packets: 10
        rx_queue_2_packets: 0
        rx_queue_3_packets: 10

10. On the DUT, delete all the NFC rules:
    $ sudo ethtool -N enp1s0 delete 63
    $ sudo ethtool -N enp1s0 delete 64

11. From the Link Partner, send another 10 ARP packets:
    $ arping -c 10 -I enp170s0 169.254.1.2

12. Now, packets are routed to Queue 0 because the value of Default Queue
    is reset back to 0:
    $ ethtool -S enp1s0 | grep rx_q.*packets
         rx_queue_0_packets: 20
         rx_queue_1_packets: 10
         rx_queue_2_packets: 0
         rx_queue_3_packets: 10

Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Co-developed-by: Blanco Alcaine Hector <hector.blanco.alcaine@intel.com>
Signed-off-by: Blanco Alcaine Hector <hector.blanco.alcaine@intel.com>
Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h         | 11 +++++++---
 drivers/net/ethernet/intel/igc/igc_defines.h |  1 +
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 18 ++++++++++++++++
 drivers/net/ethernet/intel/igc/igc_main.c    | 22 ++++++++++++++++++++
 4 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 0b35e593d5ee..c580ecc954be 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -631,6 +631,7 @@ enum igc_filter_match_flags {
 	IGC_FILTER_FLAG_DST_MAC_ADDR =	BIT(3),
 	IGC_FILTER_FLAG_USER_DATA =	BIT(4),
 	IGC_FILTER_FLAG_VLAN_ETYPE =	BIT(5),
+	IGC_FILTER_FLAG_DEFAULT_QUEUE = BIT(6),
 };
 
 struct igc_nfc_filter {
@@ -658,10 +659,14 @@ struct igc_nfc_rule {
 	bool flex;
 };
 
-/* IGC supports a total of 32 NFC rules: 16 MAC address based, 8 VLAN priority
- * based, 8 ethertype based and 32 Flex filter based rules.
+/* IGC supports a total of 65 NFC rules, listed below in order of priority:
+ *  - 16 MAC address based filtering rules (highest priority)
+ *  - 8 ethertype based filtering rules
+ *  - 32 Flex filter based filtering rules
+ *  - 8 VLAN priority based filtering rules
+ *  - 1 default queue rule (lowest priority)
  */
-#define IGC_MAX_RXNFC_RULES		64
+#define IGC_MAX_RXNFC_RULES		65
 
 struct igc_flex_filter {
 	u8 index;
diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index d80254f2a278..498ba1522ca4 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -391,6 +391,7 @@
 #define IGC_MRQC_RSS_FIELD_IPV6_TCP	0x00200000
 #define IGC_MRQC_RSS_FIELD_IPV4_UDP	0x00400000
 #define IGC_MRQC_RSS_FIELD_IPV6_UDP	0x00800000
+#define IGC_MRQC_DEFAULT_QUEUE_MASK	GENMASK(5, 3)
 
 /* Header split receive */
 #define IGC_RFCTL_IPV6_EX_DIS	0x00010000
diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index a7f397b58cd6..ecb35b693ce5 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1283,6 +1283,24 @@ static void igc_ethtool_init_nfc_rule(struct igc_nfc_rule *rule,
 		rule->flex = true;
 	else
 		rule->flex = false;
+
+	/* The wildcard rule is only applied if:
+	 *  a) None of the other filtering rules match (match_flags is zero)
+	 *  b) The flow type is ETHER_FLOW only (no additional fields set)
+	 *  c) Mask for Source MAC address is not specified (all zeros)
+	 *  d) Mask for Destination MAC address is not specified (all zeros)
+	 *  e) Mask for L2 EtherType is not specified (zero)
+	 *
+	 * If all these conditions are met, the rule is treated as a wildcard
+	 * rule. Default queue feature will be used, so that all packets that do
+	 * not match any other rule will be routed to the default queue.
+	 */
+	if (!rule->filter.match_flags &&
+	    fsp->flow_type == ETHER_FLOW &&
+	    is_zero_ether_addr(fsp->m_u.ether_spec.h_source) &&
+	    is_zero_ether_addr(fsp->m_u.ether_spec.h_dest) &&
+	    !fsp->m_u.ether_spec.h_proto)
+		rule->filter.match_flags = IGC_FILTER_FLAG_DEFAULT_QUEUE;
 }
 
 /**
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 2e12915b42a9..87311ea47018 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -3874,6 +3874,22 @@ static void igc_del_flex_filter(struct igc_adapter *adapter,
 	wr32(IGC_WUFC, wufc);
 }
 
+static void igc_set_default_queue_filter(struct igc_adapter *adapter, u32 queue)
+{
+	struct igc_hw *hw = &adapter->hw;
+	u32 mrqc = rd32(IGC_MRQC);
+
+	mrqc &= ~IGC_MRQC_DEFAULT_QUEUE_MASK;
+	mrqc |= FIELD_PREP(IGC_MRQC_DEFAULT_QUEUE_MASK, queue);
+	wr32(IGC_MRQC, mrqc);
+}
+
+static void igc_reset_default_queue_filter(struct igc_adapter *adapter)
+{
+	/* Reset the default queue to its default value which is Queue 0 */
+	igc_set_default_queue_filter(adapter, 0);
+}
+
 static int igc_enable_nfc_rule(struct igc_adapter *adapter,
 			       struct igc_nfc_rule *rule)
 {
@@ -3912,6 +3928,9 @@ static int igc_enable_nfc_rule(struct igc_adapter *adapter,
 			return err;
 	}
 
+	if (rule->filter.match_flags & IGC_FILTER_FLAG_DEFAULT_QUEUE)
+		igc_set_default_queue_filter(adapter, rule->action);
+
 	return 0;
 }
 
@@ -3939,6 +3958,9 @@ static void igc_disable_nfc_rule(struct igc_adapter *adapter,
 	if (rule->filter.match_flags & IGC_FILTER_FLAG_DST_MAC_ADDR)
 		igc_del_mac_filter(adapter, IGC_MAC_FILTER_TYPE_DST,
 				   rule->filter.dst_addr);
+
+	if (rule->filter.match_flags & IGC_FILTER_FLAG_DEFAULT_QUEUE)
+		igc_reset_default_queue_filter(adapter);
 }
 
 /**
-- 
2.34.1

Re: [Intel-wired-lan] [PATCH iwl-next, v3 2/2] igc: Add wildcard rule support to ethtool NFC using Default Queue

[Mor Bar-Gabay]

On 20/06/2025 13:02, Song Yoong Siang wrote:
> Introduce support for a lowest priority wildcard (catch-all) rule in
> ethtool's Network Flow Classification (NFC) for the igc driver. The
> wildcard rule directs all unmatched network traffic, including traffic not
> captured by Receive Side Scaling (RSS), to a specified queue. This
> functionality utilizes the Default Queue feature available in I225/I226
> hardware.
> 
> The implementation has been validated on Intel ADL-S systems with two
> back-to-back connected I226 network interfaces.
> 
> Testing Procedure:
> 1. On the Device Under Test (DUT), verify the initial statistic:
>     $ ethtool -S enp1s0 | grep rx_q.*packets
>          rx_queue_0_packets: 0
>          rx_queue_1_packets: 0
>          rx_queue_2_packets: 0
>          rx_queue_3_packets: 0
> 
> 2. From the Link Partner, send 10 ARP packets:
>     $ arping -c 10 -I enp170s0 169.254.1.2
> 
> 3. On the DUT, verify the packet reception on Queue 0:
>     $ ethtool -S enp1s0 | grep rx_q.*packets
>          rx_queue_0_packets: 10
>          rx_queue_1_packets: 0
>          rx_queue_2_packets: 0
>          rx_queue_3_packets: 0
> 
> 4. On the DUT, add a wildcard rule to route all packets to Queue 3:
>     $ sudo ethtool -N enp1s0 flow-type ether queue 3
> 
> 5. From the Link Partner, send another 10 ARP packets:
>     $ arping -c 10 -I enp170s0 169.254.1.2
> 
> 6. Now, packets are routed to Queue 3 by the wildcard (Default Queue) rule:
>     $ ethtool -S enp1s0 | grep rx_q.*packets
>          rx_queue_0_packets: 10
>          rx_queue_1_packets: 0
>          rx_queue_2_packets: 0
>          rx_queue_3_packets: 10
> 
> 7. On the DUT, add a EtherType rule to route ARP packet to Queue 1:
>     $ sudo ethtool -N enp1s0 flow-type ether proto 0x0806 queue 1
> 
> 8. From the Link Partner, send another 10 ARP packets:
>     $ arping -c 10 -I enp170s0 169.254.1.2
> 
> 9. Now, packets are routed to Queue 1 by the EtherType rule because it is
>     higher priority than the wildcard (Default Queue) rule:
>     $ ethtool -S enp1s0 | grep rx_q.*packets
>          rx_queue_0_packets: 10
>          rx_queue_1_packets: 10
>          rx_queue_2_packets: 0
>          rx_queue_3_packets: 10
> 
> 10. On the DUT, delete all the NFC rules:
>      $ sudo ethtool -N enp1s0 delete 63
>      $ sudo ethtool -N enp1s0 delete 64
> 
> 11. From the Link Partner, send another 10 ARP packets:
>      $ arping -c 10 -I enp170s0 169.254.1.2
> 
> 12. Now, packets are routed to Queue 0 because the value of Default Queue
>      is reset back to 0:
>      $ ethtool -S enp1s0 | grep rx_q.*packets
>           rx_queue_0_packets: 20
>           rx_queue_1_packets: 10
>           rx_queue_2_packets: 0
>           rx_queue_3_packets: 10
> 
> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
> Co-developed-by: Blanco Alcaine Hector <hector.blanco.alcaine@intel.com>
> Signed-off-by: Blanco Alcaine Hector <hector.blanco.alcaine@intel.com>
> Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
> ---
>   drivers/net/ethernet/intel/igc/igc.h         | 11 +++++++---
>   drivers/net/ethernet/intel/igc/igc_defines.h |  1 +
>   drivers/net/ethernet/intel/igc/igc_ethtool.c | 18 ++++++++++++++++
>   drivers/net/ethernet/intel/igc/igc_main.c    | 22 ++++++++++++++++++++
>   4 files changed, 49 insertions(+), 3 deletions(-)
> 
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>