2 files changed, 32 insertions, 2 deletions

diff --git a/drivers/net/ethernet/google/gve/gve.h b/drivers/net/ethernet/google/gve/gve.h
index 53b5244dc7bc..f27a6d5fbecf 100644
--- a/drivers/net/ethernet/google/gve/gve.h
+++ b/drivers/net/ethernet/google/gve/gve.h
@@ -610,6 +610,7 @@ struct gve_notify_block {
 	struct gve_priv *priv;
 	struct gve_tx_ring *tx; /* tx rings on this block */
 	struct gve_rx_ring *rx; /* rx rings on this block */
+	u32 irq;
 };
 
 /* Tracks allowed and current queue settings */
diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index ef902b72b9a9..79b7a677ec0b 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -9,6 +9,7 @@
 #include <linux/etherdevice.h>
 #include <linux/filter.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/sched.h>
@@ -253,6 +254,18 @@ static irqreturn_t gve_intr_dqo(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+static int gve_is_napi_on_home_cpu(struct gve_priv *priv, u32 irq)
+{
+	int cpu_curr = smp_processor_id();
+	const struct cpumask *aff_mask;
+
+	aff_mask = irq_get_effective_affinity_mask(irq);
+	if (unlikely(!aff_mask))
+		return 1;
+
+	return cpumask_test_cpu(cpu_curr, aff_mask);
+}
+
 int gve_napi_poll(struct napi_struct *napi, int budget)
 {
 	struct gve_notify_block *block;
@@ -322,8 +335,21 @@ int gve_napi_poll_dqo(struct napi_struct *napi, int budget)
 		reschedule |= work_done == budget;
 	}
 
-	if (reschedule)
-		return budget;
+	if (reschedule) {
+		/* Reschedule by returning budget only if already on the correct
+		 * cpu.
+		 */
+		if (likely(gve_is_napi_on_home_cpu(priv, block->irq)))
+			return budget;
+
+		/* If not on the cpu with which this queue's irq has affinity
+		 * with, we avoid rescheduling napi and arm the irq instead so
+		 * that napi gets rescheduled back eventually onto the right
+		 * cpu.
+		 */
+		if (work_done == budget)
+			work_done--;
+	}
 
 	if (likely(napi_complete_done(napi, work_done))) {
 		/* Enable interrupts again.
@@ -428,6 +454,7 @@ static int gve_alloc_notify_blocks(struct gve_priv *priv)
 				"Failed to receive msix vector %d\n", i);
 			goto abort_with_some_ntfy_blocks;
 		}
+		block->irq = priv->msix_vectors[msix_idx].vector;
 		irq_set_affinity_hint(priv->msix_vectors[msix_idx].vector,
 				      get_cpu_mask(i % active_cpus));
 		block->irq_db_index = &priv->irq_db_indices[i].index;
@@ -441,6 +468,7 @@ abort_with_some_ntfy_blocks:
 		irq_set_affinity_hint(priv->msix_vectors[msix_idx].vector,
 				      NULL);
 		free_irq(priv->msix_vectors[msix_idx].vector, block);
+		block->irq = 0;
 	}
 	kvfree(priv->ntfy_blocks);
 	priv->ntfy_blocks = NULL;
@@ -474,6 +502,7 @@ static void gve_free_notify_blocks(struct gve_priv *priv)
 		irq_set_affinity_hint(priv->msix_vectors[msix_idx].vector,
 				      NULL);
 		free_irq(priv->msix_vectors[msix_idx].vector, block);
+		block->irq = 0;
 	}
 	free_irq(priv->msix_vectors[priv->mgmt_msix_idx].vector, priv);
 	kvfree(priv->ntfy_blocks);