Commit c7db85d5 authored by Max Yuan's avatar Max Yuan Committed by Jakub Kicinski
Browse files

gve: Correct ethtool rx_dropped calculation 



The gve driver's "rx_dropped" statistic, exposed via `ethtool -S`,
incorrectly includes `rx_buf_alloc_fail` counts. These failures
represent an inability to allocate receive buffers, not true packet
drops where a received packet is discarded. This misrepresentation can
lead to inaccurate diagnostics.

This patch rectifies the ethtool "rx_dropped" calculation. It removes
`rx_buf_alloc_fail` from the total and adds `xdp_tx_errors` and
`xdp_redirect_errors`, which represent legitimate packet drops within
the XDP path.

Cc: stable@vger.kernel.org
Fixes: 433e274b ("gve: Add stats for gve.")
Signed-off-by: default avatarMax Yuan <maxyuan@google.com>
Reviewed-by: default avatarJordan Rhee <jordanrhee@google.com>
Reviewed-by: default avatarJoshua Washington <joshwash@google.com>
Reviewed-by: default avatarMatt Olson <maolson@google.com>
Signed-off-by: default avatarHarshitha Ramamurthy <hramamurthy@google.com>
Reviewed-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260202193925.3106272-3-hramamurthy@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7b9ebcce

drivers/net/ethernet/google/gve/gve_ethtool.c

+17 −6
Original line number Diff line number Diff line
@@ -152,10 +152,11 @@ gve_get_ethtool_stats(struct net_device *netdev, 
	u64 tmp_rx_pkts, tmp_rx_hsplit_pkt, tmp_rx_bytes, tmp_rx_hsplit_bytes,

		tmp_rx_skb_alloc_fail, tmp_rx_buf_alloc_fail,

		tmp_rx_desc_err_dropped_pkt, tmp_rx_hsplit_unsplit_pkt,

		tmp_tx_pkts, tmp_tx_bytes;

		tmp_tx_pkts, tmp_tx_bytes,

		tmp_xdp_tx_errors, tmp_xdp_redirect_errors;

	u64 rx_buf_alloc_fail, rx_desc_err_dropped_pkt, rx_hsplit_unsplit_pkt,

		rx_pkts, rx_hsplit_pkt, rx_skb_alloc_fail, rx_bytes, tx_pkts, tx_bytes,

		tx_dropped;

		tx_dropped, xdp_tx_errors, xdp_redirect_errors;

	int rx_base_stats_idx, max_rx_stats_idx, max_tx_stats_idx;

	int stats_idx, stats_region_len, nic_stats_len;

	struct stats *report_stats;
@@ -199,6 +200,7 @@ gve_get_ethtool_stats(struct net_device *netdev, 
	for (rx_pkts = 0, rx_bytes = 0, rx_hsplit_pkt = 0,

	     rx_skb_alloc_fail = 0, rx_buf_alloc_fail = 0,

	     rx_desc_err_dropped_pkt = 0, rx_hsplit_unsplit_pkt = 0,

	     xdp_tx_errors = 0, xdp_redirect_errors = 0,

	     ring = 0;

	     ring < priv->rx_cfg.num_queues; ring++) {

		if (priv->rx) {
@@ -216,6 +218,9 @@ gve_get_ethtool_stats(struct net_device *netdev, 
					rx->rx_desc_err_dropped_pkt;

				tmp_rx_hsplit_unsplit_pkt =

					rx->rx_hsplit_unsplit_pkt;

				tmp_xdp_tx_errors = rx->xdp_tx_errors;

				tmp_xdp_redirect_errors =

					rx->xdp_redirect_errors;

			} while (u64_stats_fetch_retry(&priv->rx[ring].statss,

						       start));

			rx_pkts += tmp_rx_pkts;
@@ -225,6 +230,8 @@ gve_get_ethtool_stats(struct net_device *netdev, 
			rx_buf_alloc_fail += tmp_rx_buf_alloc_fail;

			rx_desc_err_dropped_pkt += tmp_rx_desc_err_dropped_pkt;

			rx_hsplit_unsplit_pkt += tmp_rx_hsplit_unsplit_pkt;

			xdp_tx_errors += tmp_xdp_tx_errors;

			xdp_redirect_errors += tmp_xdp_redirect_errors;

		}

	}

	for (tx_pkts = 0, tx_bytes = 0, tx_dropped = 0, ring = 0;
@@ -250,8 +257,8 @@ gve_get_ethtool_stats(struct net_device *netdev, 
	data[i++] = rx_bytes;

	data[i++] = tx_bytes;

	/* total rx dropped packets */

	data[i++] = rx_skb_alloc_fail + rx_buf_alloc_fail +

		    rx_desc_err_dropped_pkt;

	data[i++] = rx_skb_alloc_fail + rx_desc_err_dropped_pkt +

		    xdp_tx_errors + xdp_redirect_errors;

	data[i++] = tx_dropped;

	data[i++] = priv->tx_timeo_cnt;

	data[i++] = rx_skb_alloc_fail;
@@ -330,6 +337,9 @@ gve_get_ethtool_stats(struct net_device *netdev, 
				tmp_rx_buf_alloc_fail = rx->rx_buf_alloc_fail;

				tmp_rx_desc_err_dropped_pkt =

					rx->rx_desc_err_dropped_pkt;

				tmp_xdp_tx_errors = rx->xdp_tx_errors;

				tmp_xdp_redirect_errors =

					rx->xdp_redirect_errors;

			} while (u64_stats_fetch_retry(&priv->rx[ring].statss,

						       start));

			data[i++] = tmp_rx_bytes;
@@ -340,8 +350,9 @@ gve_get_ethtool_stats(struct net_device *netdev, 
			data[i++] = rx->rx_frag_alloc_cnt;

			/* rx dropped packets */

			data[i++] = tmp_rx_skb_alloc_fail +

				tmp_rx_buf_alloc_fail +

				tmp_rx_desc_err_dropped_pkt;

				    tmp_rx_desc_err_dropped_pkt +

				    tmp_xdp_tx_errors +

				    tmp_xdp_redirect_errors;

			data[i++] = rx->rx_copybreak_pkt;

			data[i++] = rx->rx_copied_pkt;

			/* stats from NIC */