FAILED: patch "[PATCH] gve: set xdp redirect target only when it is available" failed to apply to 6.6-stable tree

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 415cadd505464d9a11ff5e0f6e0329c127849da5
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025022437-molecular-next-d0f6@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 415cadd505464d9a11ff5e0f6e0329c127849da5 Mon Sep 17 00:00:00 2001
From: Joshua Washington <[email protected]>
Date: Fri, 14 Feb 2025 14:43:59 -0800
Subject: [PATCH] gve: set xdp redirect target only when it is available

Before this patch the NETDEV_XDP_ACT_NDO_XMIT XDP feature flag is set by default as part of driver initialization, and is never cleared. However, this flag differs from others in that it is used as an indicator for whether the driver is ready to perform the ndo_xdp_xmit operation as part of an XDP_REDIRECT. Kernel helpers xdp_features_(set|clear)_redirect_target exist to convey this meaning.

This patch ensures that the netdev is only reported as a redirect target when XDP queues exist to forward traffic.

index 8167cc5fb0df..78d2a19593d1 100644
@@ -1116,6 +1116,16 @@ static inline u32 gve_xdp_tx_start_queue_id(struct gve_priv *priv)
 	return gve_xdp_tx_queue_id(priv, 0);
 }
 
+static inline bool gve_supports_xdp_xmit(struct gve_priv *priv)
+{
+	switch (priv->queue_format) {
+	case GVE_GQI_QPL_FORMAT:
+		return true;
+	default:
+		return false;
+	}
+}
+
 /* gqi napi handler defined in gve_main.c */
 int gve_napi_poll(struct napi_struct *napi, int budget);
 

index 533e659b15b3..92237fb0b60c 100644
@@ -1903,6 +1903,8 @@ static void gve_turndown(struct gve_priv *priv)
 	/* Stop tx queues */
 	netif_tx_disable(priv->dev);
 
+	xdp_features_clear_redirect_target(priv->dev);
+
 	gve_clear_napi_enabled(priv);
 	gve_clear_report_stats(priv);
 

@@ -1972,6 +1974,9 @@ static void gve_turnup(struct gve_priv *priv)
 		napi_schedule(&block->napi);
 	}
 
+	if (priv->num_xdp_queues && gve_supports_xdp_xmit(priv))
+		xdp_features_set_redirect_target(priv->dev, false);
+
 	gve_set_napi_enabled(priv);
 }
 

@@ -2246,7 +2251,6 @@ static void gve_set_netdev_xdp_features(struct gve_priv *priv)
 	if (priv->queue_format == GVE_GQI_QPL_FORMAT) {
 		xdp_features = NETDEV_XDP_ACT_BASIC;
 		xdp_features |= NETDEV_XDP_ACT_REDIRECT;
-		xdp_features |= NETDEV_XDP_ACT_NDO_XMIT;
 		xdp_features |= NETDEV_XDP_ACT_XSK_ZEROCOPY;
 	} else {
 		xdp_features = 0;

Before this patch the NETDEV_XDP_ACT_NDO_XMIT XDP feature flag is set by default as part of driver initialization, and is never cleared. However, this flag differs from others in that it is used as an indicator for whether the driver is ready to perform the ndo_xdp_xmit operation as part of an XDP_REDIRECT. Kernel helpers xdp_features_(set|clear)_redirect_target exist to convey this meaning.

This patch ensures that the netdev is only reported as a redirect target when XDP queues exist to forward traffic.

---
 drivers/net/ethernet/google/gve/gve.h      | 10 ++++++++++
 drivers/net/ethernet/google/gve/gve_main.c |  6 +++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

index 0d1e681be250..d59e28c86775 100644
@@ -1030,6 +1030,16 @@ static inline u32 gve_xdp_tx_start_queue_id(struct gve_priv *priv)
 	return gve_xdp_tx_queue_id(priv, 0);
 }
 
+static inline bool gve_supports_xdp_xmit(struct gve_priv *priv)
+{
+	switch (priv->queue_format) {
+	case GVE_GQI_QPL_FORMAT:
+		return true;
+	default:
+		return false;
+	}
+}
+
 /* buffers */
 int gve_alloc_page(struct gve_priv *priv, struct device *dev,
 		   struct page **page, dma_addr_t *dma,

index 90d433b36799..8cd098fe88ef 100644
@@ -1753,6 +1753,8 @@ static void gve_turndown(struct gve_priv *priv)
 	/* Stop tx queues */
 	netif_tx_disable(priv->dev);
 
+	xdp_features_clear_redirect_target(priv->dev);
+
 	gve_clear_napi_enabled(priv);
 	gve_clear_report_stats(priv);
 

@@ -1793,6 +1795,9 @@ static void gve_turnup(struct gve_priv *priv)
 		}
 	}
 
+	if (priv->num_xdp_queues && gve_supports_xdp_xmit(priv))
+		xdp_features_set_redirect_target(priv->dev, false);
+
 	gve_set_napi_enabled(priv);
 }
 

@@ -2014,7 +2019,6 @@ static void gve_set_netdev_xdp_features(struct gve_priv *priv)
 	if (priv->queue_format == GVE_GQI_QPL_FORMAT) {
 		xdp_features = NETDEV_XDP_ACT_BASIC;
 		xdp_features |= NETDEV_XDP_ACT_REDIRECT;
-		xdp_features |= NETDEV_XDP_ACT_NDO_XMIT;
 		xdp_features |= NETDEV_XDP_ACT_XSK_ZEROCOPY;
 	} else {
 		xdp_features = 0;

2.48.1.658.g4767266eb4-goog

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: 415cadd505464d9a11ff5e0f6e0329c127849da5

Note: The patch differs from the upstream commit:
---
1: 415cadd505464 ! 1: f1af823cbe6e3 gve: set xdp redirect target only when it is available
@@ Commit message

+ (cherry picked from commit 415cadd505464d9a11ff5e0f6e0329c127849da5)
+ Signed-off-by: Joshua Washington <[email protected]>

## drivers/net/ethernet/google/gve/gve.h ##
@@ drivers/net/ethernet/google/gve/gve.h: static inline u32 gve_xdp_tx_start_queue_id(struct gve_priv *priv)
@@ drivers/net/ethernet/google/gve/gve.h: static inline u32 gve_xdp_tx_start_queue_
+ }
+}
+
- /* gqi napi handler defined in gve_main.c */
- int gve_napi_poll(struct napi_struct *napi, int budget);
-
+ /* buffers */
+ int gve_alloc_page(struct gve_priv *priv, struct device *dev,
+ struct page **page, dma_addr_t *dma,

## drivers/net/ethernet/google/gve/gve_main.c ##
@@ drivers/net/ethernet/google/gve/gve_main.c: static void gve_turndown(struct gve_priv *priv)
@@ drivers/net/ethernet/google/gve/gve_main.c: static void gve_turndown(struct gve_
gve_clear_report_stats(priv);

@@ drivers/net/ethernet/google/gve/gve_main.c: static void gve_turnup(struct gve_priv *priv)
- napi_schedule(&block->napi);
+ }
}

+ if (priv->num_xdp_queues && gve_supports_xdp_xmit(priv))
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |