patch 'net/gve: do not write zero-length descriptors' has been queued to stable release 24.11.4

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 24.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/05/25. 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/b343e73b03049fbd627c62ab9ae8b40360550ac1

Thanks.

Kevin

---
>From b343e73b03049fbd627c62ab9ae8b40360550ac1 Mon Sep 17 00:00:00 2001
From: Joshua Washington <joshwash at google.com>
Date: Mon, 7 Jul 2025 16:18:07 -0700
Subject: [PATCH] net/gve: do not write zero-length descriptors

[ upstream commit 671d15dad5f41cda4887ca3bb73afafc1b9768e3 ]

Writing zero-length descriptors to the hardware can cause the hardware
to reject that packet and stop transmitting altogether.

Fixes: 4022f9999f56 ("net/gve: support basic Tx data path for DQO")

Signed-off-by: Joshua Washington <joshwash at google.com>
Reviewed-by: Ankit Garg <nktgrg at google.com>
---
 drivers/net/gve/gve_tx_dqo.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/gve/gve_tx_dqo.c b/drivers/net/gve/gve_tx_dqo.c
index 652a0e5175..b2e5aae634 100644
--- a/drivers/net/gve/gve_tx_dqo.c
+++ b/drivers/net/gve/gve_tx_dqo.c
@@ -169,4 +169,9 @@ gve_tx_burst_dqo(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 				PMD_DRV_LOG(DEBUG, "Overwriting an entry in sw_ring");
 
+			/* Skip writing descriptor if mbuf has no data. */
+			if (!tx_pkt->data_len)
+				goto finish_mbuf;
+
+			txd = &txr[tx_id];
 			sw_ring[sw_id] = tx_pkt;
 
@@ -190,4 +195,5 @@ gve_tx_burst_dqo(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 			}
 
+finish_mbuf:
 			sw_id = (sw_id + 1) & sw_mask;
 			bytes += tx_pkt->data_len;
@@ -195,5 +201,6 @@ gve_tx_burst_dqo(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 		} while (tx_pkt);
 
-		/* fill the last descriptor with End of Packet (EOP) bit */
+		/* fill the last written descriptor with End of Packet (EOP) bit */
+		txd = &txr[(tx_id - 1) & mask];
 		txd->pkt.end_of_packet = 1;
 
-- 
2.51.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2025-10-31 13:53:52.630832332 +0000
+++ 0011-net-gve-do-not-write-zero-length-descriptors.patch	2025-10-31 13:53:52.017426238 +0000
@@ -1 +1 @@
-From 671d15dad5f41cda4887ca3bb73afafc1b9768e3 Mon Sep 17 00:00:00 2001
+From b343e73b03049fbd627c62ab9ae8b40360550ac1 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 671d15dad5f41cda4887ca3bb73afafc1b9768e3 ]
+
@@ -10 +11,0 @@
-Cc: stable at dpdk.org