Re: [PATCH 6.6.y] gve: Correct ethtool rx_dropped calculation

[Greg KH <greg@kroah.com>]

On Sat, Feb 07, 2026 at 01:43:05PM -0500, Sasha Levin wrote:
> From: Max Yuan <maxyuan@google.com>
> 
> [ Upstream commit c7db85d579a1dccb624235534508c75fbf2dfe46 ]
> 
> 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: 433e274b8f7b ("gve: Add stats for gve.")
> Signed-off-by: Max Yuan <maxyuan@google.com>
> Reviewed-by: Jordan Rhee <jordanrhee@google.com>
> Reviewed-by: Joshua Washington <joshwash@google.com>
> Reviewed-by: Matt Olson <maolson@google.com>
> Signed-off-by: Harshitha Ramamurthy <hramamurthy@google.com>
> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
> Link: https://patch.msgid.link/20260202193925.3106272-3-hramamurthy@google.com
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> [ Adjust context ]
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  drivers/net/ethernet/google/gve/gve_ethtool.c | 26 ++++++++++++++-----
>  1 file changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/google/gve/gve_ethtool.c b/drivers/net/ethernet/google/gve/gve_ethtool.c
> index 22317acf16ba4..997e1d7736a84 100644
> --- a/drivers/net/ethernet/google/gve/gve_ethtool.c
> +++ b/drivers/net/ethernet/google/gve/gve_ethtool.c
> @@ -156,9 +156,11 @@ gve_get_ethtool_stats(struct net_device *netdev,
>  {
>  	u64 tmp_rx_pkts, tmp_rx_bytes, tmp_rx_skb_alloc_fail,
>  		tmp_rx_buf_alloc_fail, tmp_rx_desc_err_dropped_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_pkts,
> -		rx_skb_alloc_fail, rx_bytes, tx_pkts, tx_bytes, tx_dropped;
> +		rx_skb_alloc_fail, rx_bytes, tx_pkts, tx_bytes, tx_dropped,
> +		xdp_tx_errors, xdp_redirect_errors;
>  	int stats_idx, base_stats_idx, max_stats_idx;
>  	struct stats *report_stats;
>  	int *rx_qid_to_stats_idx;
> @@ -186,7 +188,8 @@ gve_get_ethtool_stats(struct net_device *netdev,
>  		return;
>  	}
>  	for (rx_pkts = 0, rx_bytes = 0, rx_skb_alloc_fail = 0,
> -	     rx_buf_alloc_fail = 0, rx_desc_err_dropped_pkt = 0, ring = 0;
> +	     rx_buf_alloc_fail = 0, rx_desc_err_dropped_pkt = 0,
> +	     xdp_tx_errors = 0, xdp_redirect_errors = 0, ring = 0;
>  	     ring < priv->rx_cfg.num_queues; ring++) {
>  		if (priv->rx) {
>  			do {
> @@ -200,6 +203,9 @@ 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));
>  			rx_pkts += tmp_rx_pkts;
> @@ -207,6 +213,8 @@ gve_get_ethtool_stats(struct net_device *netdev,
>  			rx_skb_alloc_fail += tmp_rx_skb_alloc_fail;
>  			rx_buf_alloc_fail += tmp_rx_buf_alloc_fail;
>  			rx_desc_err_dropped_pkt += tmp_rx_desc_err_dropped_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;
> @@ -231,8 +239,8 @@ 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;
> @@ -281,6 +289,9 @@ 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;
> @@ -290,8 +301,9 @@ 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 */
> -- 
> 2.51.0
> 
> 

Does not apply after I added your other backport :(

Can you rebase this one on top of that one?

thanks,

greg k-h