patch 'net/gve: fix DQO for chained descriptors' has been queued to stable release 23.11.1

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 23.11.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 03/31/24. 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://git.dpdk.org/dpdk-stable/log/?h=23.11-staging

This queued commit can be viewed at:
https://git.dpdk.org/dpdk-stable/commit/?h=23.11-staging&id=561a3f508fcc648f599b683656af8d8e54814789

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From 561a3f508fcc648f599b683656af8d8e54814789 Mon Sep 17 00:00:00 2001
From: Rushil Gupta <rushilg at google.com>
Date: Thu, 15 Feb 2024 10:02:30 +0000
Subject: [PATCH] net/gve: fix DQO for chained descriptors
Cc: Xueming Li <xuemingl at nvidia.com>

[ upstream commit ab2fc2cd7016ba4b65b2f9fd845f0f9a7a87ef16 ]

DQO Tx path had a bug where driver was overwriting mbufs in sw-ring.
We fixed this bug by cleaning slots for all segments.

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

Signed-off-by: Rushil Gupta <rushilg at google.com>
Reviewed-by: Joshua Washington <joshwash at google.com>
---
 drivers/net/gve/gve_tx_dqo.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/net/gve/gve_tx_dqo.c b/drivers/net/gve/gve_tx_dqo.c
index 16101de84f..30a1455b20 100644
--- a/drivers/net/gve/gve_tx_dqo.c
+++ b/drivers/net/gve/gve_tx_dqo.c
@@ -13,7 +13,7 @@ gve_tx_clean_dqo(struct gve_tx_queue *txq)
 	struct gve_tx_compl_desc *compl_desc;
 	struct gve_tx_queue *aim_txq;
 	uint16_t nb_desc_clean;
-	struct rte_mbuf *txe;
+	struct rte_mbuf *txe, *txe_next;
 	uint16_t compl_tag;
 	uint16_t next;

@@ -43,10 +43,15 @@ gve_tx_clean_dqo(struct gve_tx_queue *txq)
 		PMD_DRV_LOG(DEBUG, "GVE_COMPL_TYPE_DQO_REINJECTION !!!");
 		/* FALLTHROUGH */
 	case GVE_COMPL_TYPE_DQO_PKT:
+		/* free all segments. */
 		txe = aim_txq->sw_ring[compl_tag];
-		if (txe != NULL) {
+		while (txe != NULL) {
+			txe_next = txe->next;
 			rte_pktmbuf_free_seg(txe);
-			txe = NULL;
+			if (aim_txq->sw_ring[compl_tag] == txe)
+				aim_txq->sw_ring[compl_tag] = NULL;
+			txe = txe_next;
+			compl_tag = (compl_tag + 1) & (aim_txq->sw_size - 1);
 		}
 		break;
 	case GVE_COMPL_TYPE_DQO_MISS:
@@ -83,6 +88,7 @@ gve_tx_burst_dqo(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 	uint16_t tx_id;
 	uint16_t sw_id;
 	uint64_t bytes;
+	uint16_t first_sw_id;

 	sw_ring = txq->sw_ring;
 	txr = txq->tx_ring;
@@ -107,23 +113,25 @@ gve_tx_burst_dqo(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)

 		ol_flags = tx_pkt->ol_flags;
 		nb_used = tx_pkt->nb_segs;
-
+		first_sw_id = sw_id;
 		do {
-			txd = &txr[tx_id];
+			if (sw_ring[sw_id] != NULL)
+				PMD_DRV_LOG(DEBUG, "Overwriting an entry in sw_ring");

+			txd = &txr[tx_id];
 			sw_ring[sw_id] = tx_pkt;

 			/* fill Tx descriptor */
 			txd->pkt.buf_addr = rte_cpu_to_le_64(rte_mbuf_data_iova(tx_pkt));
 			txd->pkt.dtype = GVE_TX_PKT_DESC_DTYPE_DQO;
-			txd->pkt.compl_tag = rte_cpu_to_le_16(sw_id);
+			txd->pkt.compl_tag = rte_cpu_to_le_16(first_sw_id);
 			txd->pkt.buf_size = RTE_MIN(tx_pkt->data_len, GVE_TX_MAX_BUF_SIZE_DQO);

 			/* size of desc_ring and sw_ring could be different */
 			tx_id = (tx_id + 1) & mask;
 			sw_id = (sw_id + 1) & sw_mask;

-			bytes += tx_pkt->pkt_len;
+			bytes += tx_pkt->data_len;
 			tx_pkt = tx_pkt->next;
 		} while (tx_pkt);

--
2.34.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2024-03-05 17:39:34.282763810 +0800
+++ 0110-net-gve-fix-DQO-for-chained-descriptors.patch	2024-03-05 17:39:30.903566497 +0800
@@ -1 +1 @@
-From ab2fc2cd7016ba4b65b2f9fd845f0f9a7a87ef16 Mon Sep 17 00:00:00 2001
+From 561a3f508fcc648f599b683656af8d8e54814789 Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Xueming Li <xuemingl at nvidia.com>
+
+[ upstream commit ab2fc2cd7016ba4b65b2f9fd845f0f9a7a87ef16 ]
@@ -10 +12,0 @@
-Cc: stable at dpdk.org