patch 'net/iavf: fix race condition on link status change' has been queued to stable release 25.11.3

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 25.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 08/01/26. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/82b553fa0fb5c758c42310d6ae7523acf0b6beb5

Thanks.

Kevin

---
>From 82b553fa0fb5c758c42310d6ae7523acf0b6beb5 Mon Sep 17 00:00:00 2001
From: Anurag Mandal <anurag.mandal at intel.com>
Date: Wed, 10 Jun 2026 14:12:30 +0000
Subject: [PATCH] net/iavf: fix race condition on link status change

[ upstream commit 105d9fcefbee4d0562b4b79857865945ae985705 ]

Handle link-change events through a common static function that
reads the correct advanced & legacy link fields properly and
updates no-poll/watchdog/LSC state consistently, avoiding race
conditions with application update of LSC.

Fixes: 5e03e316c753 ("net/iavf: handle virtchnl event message without interrupt")
Fixes: 48de41ca11f0 ("net/avf: enable link status update")

Signed-off-by: Anurag Mandal <anurag.mandal at intel.com>
Acked-by: Ciara Loftus <ciara.loftus at intel.com>
---
 drivers/net/intel/iavf/iavf_vchnl.c | 115 +++++++++++++++-------------
 1 file changed, 63 insertions(+), 52 deletions(-)

diff --git a/drivers/net/intel/iavf/iavf_vchnl.c b/drivers/net/intel/iavf/iavf_vchnl.c
index 316caa8c58..b497363d81 100644
--- a/drivers/net/intel/iavf/iavf_vchnl.c
+++ b/drivers/net/intel/iavf/iavf_vchnl.c
@@ -217,4 +217,65 @@ iavf_convert_link_speed(enum virtchnl_link_speed virt_link_speed)
 }
 
+/*
+ * iavf_handle_link_change_event: common handler for VIRTCHNL link change events
+ *
+ * @dev: pointer to rte_eth_dev for this VF
+ * @vpe: pointer to the virtchnl_pf_event payload received from the PF
+ *
+ * Handle PF link-change event: decode adv/legacy link info, update VF
+ * link state, sync no-poll/watchdog behavior & notify app via LSC event.
+ */
+static void
+iavf_handle_link_change_event(struct rte_eth_dev *dev,
+			      struct virtchnl_pf_event *vpe)
+{
+	struct iavf_adapter *adapter =
+		IAVF_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
+	struct iavf_info *vf = &adapter->vf;
+	bool adv_link_speed;
+
+	adv_link_speed = (vf->vf_res != NULL) &&
+		((vf->vf_res->vf_cap_flags & VIRTCHNL_VF_CAP_ADV_LINK_SPEED) != 0);
+
+	if (adv_link_speed) {
+		vf->link_up = vpe->event_data.link_event_adv.link_status;
+		vf->link_speed = vpe->event_data.link_event_adv.link_speed;
+	} else {
+		enum virtchnl_link_speed speed;
+
+		vf->link_up = vpe->event_data.link_event.link_status;
+		speed = vpe->event_data.link_event.link_speed;
+		vf->link_speed = iavf_convert_link_speed(speed);
+	}
+
+	iavf_dev_link_update(dev, 0);
+
+	/*
+	 * Update watchdog/no_poll state BEFORE notifying the application via
+	 * the LSC event. Otherwise the application's link-up callback could
+	 * race with stale (link-down) no_poll/watchdog state and either
+	 * continue to drop traffic or trigger a spurious reset detection.
+	 *
+	 * Keeping the watchdog enabled whenever the link cannot be trusted
+	 * (link is down or a VF reset is in progress); the watchdog drives
+	 * auto-reset recovery, so it must remain armed in those cases.
+	 */
+	if (vf->link_up && !vf->vf_reset)
+		iavf_dev_watchdog_disable(adapter);
+	else
+		iavf_dev_watchdog_enable(adapter);
+
+	if (adapter->devargs.no_poll_on_link_down) {
+		iavf_set_no_poll(adapter, true);
+		PMD_DRV_LOG(DEBUG, "VF no poll turned %s",
+			    adapter->no_poll ? "on" : "off");
+	}
+
+	iavf_dev_event_post(dev, RTE_ETH_EVENT_INTR_LSC, NULL, 0);
+
+	PMD_DRV_LOG(INFO, "Link status update:%s",
+		vf->link_up ? "up" : "down");
+}
+
 /* Read data in admin queue to get msg from pf driver */
 static enum iavf_aq_result
@@ -254,32 +315,5 @@ iavf_read_msg_from_pf(struct iavf_adapter *adapter, uint16_t buf_len,
 		switch (vpe->event) {
 		case VIRTCHNL_EVENT_LINK_CHANGE:
-			vf->link_up =
-				vpe->event_data.link_event.link_status;
-			if (vf->vf_res != NULL &&
-			    vf->vf_res->vf_cap_flags & VIRTCHNL_VF_CAP_ADV_LINK_SPEED) {
-				vf->link_speed =
-				    vpe->event_data.link_event_adv.link_speed;
-			} else {
-				enum virtchnl_link_speed speed;
-				speed = vpe->event_data.link_event.link_speed;
-				vf->link_speed = iavf_convert_link_speed(speed);
-			}
-			iavf_dev_link_update(vf->eth_dev, 0);
-			iavf_dev_event_post(vf->eth_dev, RTE_ETH_EVENT_INTR_LSC, NULL, 0);
-			if (vf->link_up && !vf->vf_reset) {
-				iavf_dev_watchdog_disable(adapter);
-			} else {
-				if (!vf->link_up)
-					iavf_dev_watchdog_enable(adapter);
-			}
-			if (adapter->devargs.no_poll_on_link_down) {
-				iavf_set_no_poll(adapter, true);
-				if (adapter->no_poll)
-					PMD_DRV_LOG(DEBUG, "VF no poll turned on");
-				else
-					PMD_DRV_LOG(DEBUG, "VF no poll turned off");
-			}
-			PMD_DRV_LOG(INFO, "Link status update:%s",
-					vf->link_up ? "up" : "down");
+			iavf_handle_link_change_event(vf->eth_dev, vpe);
 			break;
 		case VIRTCHNL_EVENT_RESET_IMPENDING:
@@ -480,28 +514,5 @@ iavf_handle_pf_event_msg(struct rte_eth_dev *dev, uint8_t *msg,
 	case VIRTCHNL_EVENT_LINK_CHANGE:
 		PMD_DRV_LOG(DEBUG, "VIRTCHNL_EVENT_LINK_CHANGE event");
-		vf->link_up = pf_msg->event_data.link_event.link_status;
-		if (vf->vf_res->vf_cap_flags & VIRTCHNL_VF_CAP_ADV_LINK_SPEED) {
-			vf->link_speed =
-				pf_msg->event_data.link_event_adv.link_speed;
-		} else {
-			enum virtchnl_link_speed speed;
-			speed = pf_msg->event_data.link_event.link_speed;
-			vf->link_speed = iavf_convert_link_speed(speed);
-		}
-		iavf_dev_link_update(dev, 0);
-		if (vf->link_up && !vf->vf_reset) {
-			iavf_dev_watchdog_disable(adapter);
-		} else {
-			if (!vf->link_up)
-				iavf_dev_watchdog_enable(adapter);
-		}
-		if (adapter->devargs.no_poll_on_link_down) {
-			iavf_set_no_poll(adapter, true);
-			if (adapter->no_poll)
-				PMD_DRV_LOG(DEBUG, "VF no poll turned on");
-			else
-				PMD_DRV_LOG(DEBUG, "VF no poll turned off");
-		}
-		iavf_dev_event_post(dev, RTE_ETH_EVENT_INTR_LSC, NULL, 0);
+		iavf_handle_link_change_event(dev, pf_msg);
 		break;
 	case VIRTCHNL_EVENT_PF_DRIVER_CLOSE:
-- 
2.55.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2026-07-28 16:54:52.718374678 +0100
+++ 0066-net-iavf-fix-race-condition-on-link-status-change.patch	2026-07-28 16:54:50.814728862 +0100
@@ -1 +1 @@
-From 105d9fcefbee4d0562b4b79857865945ae985705 Mon Sep 17 00:00:00 2001
+From 82b553fa0fb5c758c42310d6ae7523acf0b6beb5 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 105d9fcefbee4d0562b4b79857865945ae985705 ]
+
@@ -13 +14,0 @@
-Cc: stable at dpdk.org
@@ -22 +23 @@
-index 08ab11ccf1..62d6137294 100644
+index 316caa8c58..b497363d81 100644
@@ -125 +126 @@
-@@ -538,28 +572,5 @@ iavf_handle_pf_event_msg(struct rte_eth_dev *dev, uint8_t *msg,
+@@ -480,28 +514,5 @@ iavf_handle_pf_event_msg(struct rte_eth_dev *dev, uint8_t *msg,