From 3577b1ee97dcfe9ff1b9e050bed55f17c435a93d Mon Sep 17 00:00:00 2001
From: Ciara Loftus <ciara.loftus@intel.com>
Date: Tue, 14 May 2024 08:41:54 +0000
Subject: [PATCH] net/af_xdp: fix stats reset

[ upstream commit 3577b1ee97dcfe9ff1b9e050bed55f17c435a93d ]

The imissed statistic was not properly reset because it was
read directly from the kernel statistics. To fix this, take note
of the kernel statistic when the stats are reset and deduct this
value from the kernel statistic read during statistics get.

Bugzilla ID: 1430
Fixes: f1debd77efaf ("net/af_xdp: introduce AF_XDP PMD")
Cc: stable@dpdk.org

Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Acked-by: Maryam Tahhan <mtahhan@redhat.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
---
 drivers/net/af_xdp/rte_eth_af_xdp.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 0db761a204..25e67851f6 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -126,6 +126,7 @@ struct rx_stats {
 	uint64_t rx_pkts;
 	uint64_t rx_bytes;
 	uint64_t rx_dropped;
+	uint64_t imissed_offset;
 };
 
 struct pkt_rx_queue {
@@ -892,7 +893,7 @@ eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
 			AF_XDP_LOG(ERR, "getsockopt() failed for XDP_STATISTICS.\n");
 			return -1;
 		}
-		stats->imissed += xdp_stats.rx_dropped;
+		stats->imissed += xdp_stats.rx_dropped - rxq->stats.imissed_offset;
 
 		stats->opackets += stats->q_opackets[i];
 		stats->obytes += stats->q_obytes[i];
@@ -905,13 +906,25 @@ static int
 eth_stats_reset(struct rte_eth_dev *dev)
 {
 	struct pmd_internals *internals = dev->data->dev_private;
-	int i;
+	struct pmd_process_private *process_private = dev->process_private;
+	struct xdp_statistics xdp_stats;
+	socklen_t optlen;
+	int i, ret, fd;
 
 	for (i = 0; i < internals->queue_cnt; i++) {
 		memset(&internals->rx_queues[i].stats, 0,
 					sizeof(struct rx_stats));
 		memset(&internals->tx_queues[i].stats, 0,
 					sizeof(struct tx_stats));
+		fd = process_private->rxq_xsk_fds[i];
+		optlen = sizeof(struct xdp_statistics);
+		ret = fd >= 0 ? getsockopt(fd, SOL_XDP, XDP_STATISTICS,
+					   &xdp_stats, &optlen) : -1;
+		if (ret != 0) {
+			AF_XDP_LOG(ERR, "getsockopt() failed for XDP_STATISTICS.\n");
+			return -1;
+		}
+		internals->rx_queues[i].stats.imissed_offset = xdp_stats.rx_dropped;
 	}
 
 	return 0;
-- 
2.33.0

