patch 'net/failsafe: fix Rx/Tx burst after sub-device removal' has been queued to stable release 24.11.9

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 24.11.9

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/07/26. 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/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/042d72778e4a7109f309b698059813e3a8da0b29

Thanks.

Luca Boccassi

---
>From 042d72778e4a7109f309b698059813e3a8da0b29 Mon Sep 17 00:00:00 2001
From: Sandeep Penigalapati <sandeep.penigalapati at intel.com>
Date: Thu, 15 Oct 2026 16:19:26 +0000
Subject: [PATCH] net/failsafe: fix Rx/Tx burst after sub-device removal

[ upstream commit c07fd9086ebefc8531f932e3ee65896313d81c02 ]

To cope with a disappearing sub-device, fail-safe swapped its Rx/Tx
burst functions to "safe" variants when a removal was handled. This has
no effect: rte_eth_dev_start() copies the burst functions into
rte_eth_fp_ops after calling the PMD start, and the data path invokes
them through that structure. Replacing dev->rx_pkt_burst and
dev->tx_pkt_burst at runtime is therefore ignored, and the fast
variants installed at start keep dereferencing the removed sub-device,
leading to a crash.

Drop failsafe_set_burst_fn() and the _fast burst variants and keep a
single burst path that checks the sub-device state on each call through
an unlikely() guard.

Fixes: c87d435a4d79 ("ethdev: copy fast-path API into separate structure")

Signed-off-by: Sandeep Penigalapati <sandeep.penigalapati at intel.com>
---
 drivers/net/failsafe/failsafe_ether.c   |  2 -
 drivers/net/failsafe/failsafe_private.h |  8 ---
 drivers/net/failsafe/failsafe_rxtx.c    | 83 +------------------------
 3 files changed, 1 insertion(+), 92 deletions(-)

diff --git a/drivers/net/failsafe/failsafe_ether.c b/drivers/net/failsafe/failsafe_ether.c
index 44d04ee394f..1fce49b0ab2 100644
--- a/drivers/net/failsafe/failsafe_ether.c
+++ b/drivers/net/failsafe/failsafe_ether.c
@@ -600,8 +600,6 @@ failsafe_eth_rmv_event_callback(uint16_t port_id __rte_unused,
 		return -1;
 	/* Switch as soon as possible tx_dev. */
 	fs_switch_dev(fs_dev(sdev), sdev);
-	/* Use safe bursts in any case. */
-	failsafe_set_burst_fn(fs_dev(sdev), 1);
 	/*
 	 * Async removal, the sub-PMD will try to unregister
 	 * the callback at the source of the current thread context.
diff --git a/drivers/net/failsafe/failsafe_private.h b/drivers/net/failsafe/failsafe_private.h
index babea6016e5..dfd67031371 100644
--- a/drivers/net/failsafe/failsafe_private.h
+++ b/drivers/net/failsafe/failsafe_private.h
@@ -208,18 +208,11 @@ int failsafe_hotplug_alarm_cancel(struct rte_eth_dev *dev);
 
 /* RX / TX */
 
-void failsafe_set_burst_fn(struct rte_eth_dev *dev, int force_safe);
-
 uint16_t failsafe_rx_burst(void *rxq,
 		struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
 uint16_t failsafe_tx_burst(void *txq,
 		struct rte_mbuf **tx_pkts, uint16_t nb_pkts);
 
-uint16_t failsafe_rx_burst_fast(void *rxq,
-		struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
-uint16_t failsafe_tx_burst_fast(void *txq,
-		struct rte_mbuf **tx_pkts, uint16_t nb_pkts);
-
 /* ARGS */
 
 int failsafe_args_parse(struct rte_eth_dev *dev, const char *params);
@@ -484,7 +477,6 @@ fs_switch_dev(struct rte_eth_dev *dev,
 	} else {
 		return;
 	}
-	failsafe_set_burst_fn(dev, 0);
 	rte_wmb();
 }
 
diff --git a/drivers/net/failsafe/failsafe_rxtx.c b/drivers/net/failsafe/failsafe_rxtx.c
index fe672932998..707fe60a36c 100644
--- a/drivers/net/failsafe/failsafe_rxtx.c
+++ b/drivers/net/failsafe/failsafe_rxtx.c
@@ -28,39 +28,6 @@ fs_tx_unsafe(struct sub_device *sdev)
 		(sdev->state != DEV_STARTED);
 }
 
-void
-failsafe_set_burst_fn(struct rte_eth_dev *dev, int force_safe)
-{
-	struct sub_device *sdev;
-	uint8_t i;
-	int need_safe;
-	int safe_set;
-
-	need_safe = force_safe;
-	FOREACH_SUBDEV(sdev, i, dev)
-		need_safe |= fs_rx_unsafe(sdev);
-	safe_set = (dev->rx_pkt_burst == &failsafe_rx_burst);
-	if (need_safe && !safe_set) {
-		DEBUG("Using safe RX bursts%s",
-		      (force_safe ? " (forced)" : ""));
-		dev->rx_pkt_burst = &failsafe_rx_burst;
-	} else if (!need_safe && safe_set) {
-		DEBUG("Using fast RX bursts");
-		dev->rx_pkt_burst = &failsafe_rx_burst_fast;
-	}
-	need_safe = force_safe || fs_tx_unsafe(TX_SUBDEV(dev));
-	safe_set = (dev->tx_pkt_burst == &failsafe_tx_burst);
-	if (need_safe && !safe_set) {
-		DEBUG("Using safe TX bursts%s",
-		      (force_safe ? " (forced)" : ""));
-		dev->tx_pkt_burst = &failsafe_tx_burst;
-	} else if (!need_safe && safe_set) {
-		DEBUG("Using fast TX bursts");
-		dev->tx_pkt_burst = &failsafe_tx_burst_fast;
-	}
-	rte_wmb();
-}
-
 /*
  * Override source port in Rx packets.
  *
@@ -89,7 +56,7 @@ failsafe_rx_burst(void *queue,
 	rxq = queue;
 	sdev = rxq->sdev;
 	do {
-		if (fs_rx_unsafe(sdev)) {
+		if (unlikely(fs_rx_unsafe(sdev))) {
 			nb_rx = 0;
 			sdev = sdev->next;
 			continue;
@@ -108,34 +75,6 @@ failsafe_rx_burst(void *queue,
 	return nb_rx;
 }
 
-uint16_t
-failsafe_rx_burst_fast(void *queue,
-			 struct rte_mbuf **rx_pkts,
-			 uint16_t nb_pkts)
-{
-	struct sub_device *sdev;
-	struct rxq *rxq;
-	void *sub_rxq;
-	uint16_t nb_rx;
-
-	rxq = queue;
-	sdev = rxq->sdev;
-	do {
-		RTE_ASSERT(!fs_rx_unsafe(sdev));
-		sub_rxq = ETH(sdev)->data->rx_queues[rxq->qid];
-		FS_ATOMIC_P(rxq->refcnt[sdev->sid]);
-		nb_rx = ETH(sdev)->
-			rx_pkt_burst(sub_rxq, rx_pkts, nb_pkts);
-		FS_ATOMIC_V(rxq->refcnt[sdev->sid]);
-		sdev = sdev->next;
-	} while (nb_rx == 0 && sdev != rxq->sdev);
-	rxq->sdev = sdev;
-	if (nb_rx)
-		failsafe_rx_set_port(rx_pkts, nb_rx,
-				     rxq->priv->data->port_id);
-	return nb_rx;
-}
-
 uint16_t
 failsafe_tx_burst(void *queue,
 		  struct rte_mbuf **tx_pkts,
@@ -156,23 +95,3 @@ failsafe_tx_burst(void *queue,
 	FS_ATOMIC_V(txq->refcnt[sdev->sid]);
 	return nb_tx;
 }
-
-uint16_t
-failsafe_tx_burst_fast(void *queue,
-			 struct rte_mbuf **tx_pkts,
-			 uint16_t nb_pkts)
-{
-	struct sub_device *sdev;
-	struct txq *txq;
-	void *sub_txq;
-	uint16_t nb_tx;
-
-	txq = queue;
-	sdev = TX_SUBDEV(&rte_eth_devices[txq->priv->data->port_id]);
-	RTE_ASSERT(!fs_tx_unsafe(sdev));
-	sub_txq = ETH(sdev)->data->tx_queues[txq->qid];
-	FS_ATOMIC_P(txq->refcnt[sdev->sid]);
-	nb_tx = ETH(sdev)->tx_pkt_burst(sub_txq, tx_pkts, nb_pkts);
-	FS_ATOMIC_V(txq->refcnt[sdev->sid]);
-	return nb_tx;
-}
-- 
2.47.3

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2026-11-05 16:42:47.536513132 +0000
+++ 0067-net-failsafe-fix-Rx-Tx-burst-after-sub-device-remova.patch	2026-11-05 16:42:44.997063057 +0000
@@ -1 +1 @@
-From c07fd9086ebefc8531f932e3ee65896313d81c02 Mon Sep 17 00:00:00 2001
+From 042d72778e4a7109f309b698059813e3a8da0b29 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit c07fd9086ebefc8531f932e3ee65896313d81c02 ]
+
@@ -20 +21,0 @@
-Cc: stable at dpdk.org
@@ -30 +31 @@
-index 92a279a5b9..2c183ea29a 100644
+index 44d04ee394f..1fce49b0ab2 100644
@@ -33 +34 @@
-@@ -591,8 +591,6 @@ failsafe_eth_rmv_event_callback(uint16_t port_id __rte_unused,
+@@ -600,8 +600,6 @@ failsafe_eth_rmv_event_callback(uint16_t port_id __rte_unused,
@@ -43 +44 @@
-index aae091e792..0f14080394 100644
+index babea6016e5..dfd67031371 100644
@@ -65 +66 @@
-@@ -487,7 +480,6 @@ fs_switch_dev(struct rte_eth_dev *dev,
+@@ -484,7 +477,6 @@ fs_switch_dev(struct rte_eth_dev *dev,
@@ -74 +75 @@
-index 500483bda3..8d53d9dd40 100644
+index fe672932998..707fe60a36c 100644