From: Chengchang Tang <tangchengchang@huawei.com> Currently, statistics may overflow in some scenarios. For example, if HW statistics are reset by stats reset operation, but there are still a lot of residual packets exist in the HW queues and these packets are error packets, flip may occurred because the ipacket is obtained by substracting the number of software error packets from the number of HW received packets. This patch verifies the calculation and returns 0 when overflow may occur. Fixes: 8839c5e202f3 ("net/hns3: support device stats") Cc: stable@dpdk.org Signed-off-by: Chengchang Tang <tangchengchang@huawei.com> Signed-off-by: Lijun Ou <oulijun@huawei.com> --- drivers/net/hns3/hns3_stats.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/net/hns3/hns3_stats.c b/drivers/net/hns3/hns3_stats.c index e58ebea..58cce35 100644 --- a/drivers/net/hns3/hns3_stats.c +++ b/drivers/net/hns3/hns3_stats.c @@ -637,8 +637,14 @@ hns3_stats_get(struct rte_eth_dev *eth_dev, struct rte_eth_stats *rte_stats) #endif rte_stats->oerrors = 0; - rte_stats->ipackets = stats->rcb_rx_ring_pktnum_rcd - - rte_stats->ierrors; + /* + * If HW statistics are reset by stats_reset, but a lot of residual + * packets exist in the hardware queue and these packets are error + * packets, flip overflow may occurred. So return 0 in this case. + */ + rte_stats->ipackets = + stats->rcb_rx_ring_pktnum_rcd > rte_stats->ierrors ? + stats->rcb_rx_ring_pktnum_rcd - rte_stats->ierrors : 0; rte_stats->opackets = stats->rcb_tx_ring_pktnum_rcd - rte_stats->oerrors; rte_stats->rx_nombuf = eth_dev->data->rx_mbuf_alloc_failed; @@ -889,8 +895,15 @@ hns3_rxq_basic_stats_get(struct rte_eth_dev *dev, struct rte_eth_xstat *xstats, rxq_stats = &rxq->basic_stats; rxq_stats->errors = rxq->err_stats.l2_errors + rxq->err_stats.pkt_len_errors; - rxq_stats->packets = stats->rcb_rx_ring_pktnum[i] - - rxq_stats->errors; + /* + * If HW statistics are reset by stats_reset, but a lot of + * residual packets exist in the hardware queue and these + * packets are error packets, flip overflow may occurred. + * So return 0 in this case. + */ + rxq_stats->packets = + stats->rcb_rx_ring_pktnum[i] > rxq_stats->errors ? + stats->rcb_rx_ring_pktnum[i] - rxq_stats->errors : 0; for (j = 0; j < HNS3_NUM_RXQ_BASIC_STATS; j++) { val = (char *)rxq_stats + -- 2.7.4