patch 'net/gve: reject Tx packets that cannot fit in the ring' 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/9b6546be8054ce1f5d88e1e93ff748febddb1ba1

Thanks.

Luca Boccassi

---
>From 9b6546be8054ce1f5d88e1e93ff748febddb1ba1 Mon Sep 17 00:00:00 2001
From: Tathagat Priyadarshi <tathagat.dpdk at gmail.com>
Date: Fri, 16 Oct 2026 17:45:43 +0000
Subject: [PATCH] net/gve: reject Tx packets that cannot fit in the ring

[ upstream commit d7d43d10fff0d67c59ed2d0a95eb93f8d7775e9c ]

A TSO packet needing more descriptors than the ring can ever have
free fails the ring space check on every burst and blocks the queue.
One slot is always reserved, the cacheline overlap margin must stay
free, and up to GVE_TX_MIN_RE_INTERVAL - 1 posted descriptors are not
reclaimed until more are posted.

Drop such packets and count them as too_many_descs.

Fixes: 403c671a46b6 ("net/gve: support TSO in DQO RDA")

Signed-off-by: Tathagat Priyadarshi <tathagat.dpdk at gmail.com>
---
 drivers/net/gve/gve_tx_dqo.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/net/gve/gve_tx_dqo.c b/drivers/net/gve/gve_tx_dqo.c
index 350bddd4ff2..c08f44792f7 100644
--- a/drivers/net/gve/gve_tx_dqo.c
+++ b/drivers/net/gve/gve_tx_dqo.c
@@ -80,14 +80,30 @@ gve_tx_clean_descs_dqo(struct gve_tx_queue *txq, uint16_t nb_descs) {
 		gve_tx_clean_dqo(txq);
 }
 
+/* Max descriptors a single packet may use. A larger packet can never pass
+ * gve_can_tx(): one slot is always reserved, the cacheline overlap margin
+ * must stay free, and up to GVE_TX_MIN_RE_INTERVAL - 1 descriptors posted
+ * after the last report_event are not reclaimed until more are posted.
+ */
+static inline int
+gve_tx_max_pkt_descs(const struct gve_tx_queue *txq)
+{
+	return (int)txq->nb_tx_desc - 1 - GVE_TX_MIN_DESC_PREVENT_CACHE_OVERLAP -
+		(GVE_TX_MIN_RE_INTERVAL - 1);
+}
+
 /* GVE expects at most 10 data descriptors per mtu-sized segment. Beyond this,
  * the hardware will assume the driver is malicious and stop transmitting
  * packets altogether. Validate that a packet can be sent to avoid sending
  * posting descriptors for an invalid packet.
  */
 static inline bool
-gve_tx_validate_descs(struct rte_mbuf *tx_pkt, uint16_t nb_descs, bool is_tso)
+gve_tx_validate_descs(const struct gve_tx_queue *txq, struct rte_mbuf *tx_pkt,
+		      uint16_t nb_descs, bool is_tso)
 {
+	if (nb_descs > gve_tx_max_pkt_descs(txq))
+		return false;
+
 	if (!is_tso)
 		return nb_descs <= GVE_TX_MAX_DATA_DESCS;
 
@@ -226,7 +242,7 @@ gve_tx_burst_dqo(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 		nb_descs += tso;
 
 		/* Drop packet if it doesn't adhere to hardware limits. */
-		if (!gve_tx_validate_descs(tx_pkt, nb_descs, tso)) {
+		if (!gve_tx_validate_descs(txq, tx_pkt, nb_descs, tso)) {
 			txq->stats.too_many_descs++;
 			rte_pktmbuf_free(tx_pkt);
 			continue;
-- 
2.47.3

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2026-11-05 16:42:48.376949137 +0000
+++ 0090-net-gve-reject-Tx-packets-that-cannot-fit-in-the-rin.patch	2026-11-05 16:42:45.025063894 +0000
@@ -1 +1 @@
-From d7d43d10fff0d67c59ed2d0a95eb93f8d7775e9c Mon Sep 17 00:00:00 2001
+From 9b6546be8054ce1f5d88e1e93ff748febddb1ba1 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit d7d43d10fff0d67c59ed2d0a95eb93f8d7775e9c ]
+
@@ -15 +16,0 @@
-Cc: stable at dpdk.org
@@ -23 +24 @@
-index 281700b463..46a03d482d 100644
+index 350bddd4ff2..c08f44792f7 100644
@@ -26 +27 @@
-@@ -123,14 +123,30 @@ gve_tx_clean_descs_dqo(struct gve_tx_queue *txq, uint16_t nb_descs) {
+@@ -80,14 +80,30 @@ gve_tx_clean_descs_dqo(struct gve_tx_queue *txq, uint16_t nb_descs) {
@@ -58 +59 @@
-@@ -294,7 +310,7 @@ gve_tx_burst_dqo(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
+@@ -226,7 +242,7 @@ gve_tx_burst_dqo(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)