net: ethtool: Track pause storm events

With TX pause enabled, if a device is unable to pass packets up to the
stack (e.g., CPU is hanged), the device can cause pause storm. Given
that devices can have native support to protect the neighbor from such
flooding, such events need some tracking. This support is to track TX
pause storm events for better observability.

Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
Link: https://patch.msgid.link/20260302230149.1580195-2-mohsin.bashr@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 0a2d234..4707063 100644 (file)
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -879,6 +879,19 @@ attribute-sets:
       -
         name: rx-frames
         type: u64
+      -
+        name: tx-pause-storm-events
+        type: u64
+        doc: >-
+            TX pause storm event count. Increments each time device
+            detects that its pause assertion condition has been true
+            for too long for normal operation. As a result, the device
+            has temporarily disabled its own Pause TX function to
+            protect the network from itself.
+            This counter should never increment under normal overload
+            conditions; it indicates catastrophic failure like an OS
+            crash. The rate of incrementing is implementation specific.
+
   -
     name: pause
     attr-cnt-name: __ethtool-a-pause-cnt

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 798abec..83c3758 100644 (file)
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -512,12 +512,14 @@ struct ethtool_eth_ctrl_stats {
  *
  *     Equivalent to `30.3.4.3 aPAUSEMACCtrlFramesReceived`
  *     from the standard.
+ * @tx_pause_storm_events: TX pause storm event count (see ethtool.yaml).
  */
 struct ethtool_pause_stats {
        enum ethtool_mac_stats_src src;
        struct_group(stats,
                u64 tx_pause_frames;
                u64 rx_pause_frames;
+               u64 tx_pause_storm_events;
        );
 };
 

diff --git a/include/uapi/linux/ethtool_netlink_generated.h b/include/uapi/linux/ethtool_netlink_generated.h
index 556a0c8..114b830 100644 (file)
--- a/include/uapi/linux/ethtool_netlink_generated.h
+++ b/include/uapi/linux/ethtool_netlink_generated.h
@@ -381,6 +381,7 @@ enum {
        ETHTOOL_A_PAUSE_STAT_PAD,
        ETHTOOL_A_PAUSE_STAT_TX_FRAMES,
        ETHTOOL_A_PAUSE_STAT_RX_FRAMES,
+       ETHTOOL_A_PAUSE_STAT_TX_PAUSE_STORM_EVENTS,
 
        __ETHTOOL_A_PAUSE_STAT_CNT,
        ETHTOOL_A_PAUSE_STAT_MAX = (__ETHTOOL_A_PAUSE_STAT_CNT - 1)

diff --git a/net/ethtool/pause.c b/net/ethtool/pause.c
index 0f9af1e..5d28f64 100644 (file)
--- a/net/ethtool/pause.c
+++ b/net/ethtool/pause.c
@@ -130,7 +130,9 @@ static int pause_put_stats(struct sk_buff *skb,
        if (ethtool_put_stat(skb, pause_stats->tx_pause_frames,
                             ETHTOOL_A_PAUSE_STAT_TX_FRAMES, pad) ||
            ethtool_put_stat(skb, pause_stats->rx_pause_frames,
-                            ETHTOOL_A_PAUSE_STAT_RX_FRAMES, pad))
+                            ETHTOOL_A_PAUSE_STAT_RX_FRAMES, pad) ||
+           ethtool_put_stat(skb, pause_stats->tx_pause_storm_events,
+                            ETHTOOL_A_PAUSE_STAT_TX_PAUSE_STORM_EVENTS, pad))
                goto err_cancel;
 
        nla_nest_end(skb, nest);