gve: defer interrupt enabling until NAPI registration

Currently, interrupts are automatically enabled immediately upon
request. This allows interrupt to fire before the associated NAPI
context is fully initialized and cause failures like below:

[    0.946369] Call Trace:
[    0.946369]  <IRQ>
[    0.946369]  __napi_poll+0x2a/0x1e0
[    0.946369]  net_rx_action+0x2f9/0x3f0
[    0.946369]  handle_softirqs+0xd6/0x2c0
[    0.946369]  ? handle_edge_irq+0xc1/0x1b0
[    0.946369]  __irq_exit_rcu+0xc3/0xe0
[    0.946369]  common_interrupt+0x81/0xa0
[    0.946369]  </IRQ>
[    0.946369]  <TASK>
[    0.946369]  asm_common_interrupt+0x22/0x40
[    0.946369] RIP: 0010:pv_native_safe_halt+0xb/0x10

Use the `IRQF_NO_AUTOEN` flag when requesting interrupts to prevent auto
enablement and explicitly enable the interrupt in NAPI initialization
path (and disable it during NAPI teardown).

This ensures that interrupt lifecycle is strictly coupled with
readiness of NAPI context.

Cc: [email protected]
Fixes: 1dfc2e4 ("gve: Refactor napi add and remove functions")
Signed-off-by: Ankit Garg <[email protected]>
Reviewed-by: Jordan Rhee <[email protected]>
Reviewed-by: Joshua Washington <[email protected]>
Signed-off-by: Harshitha Ramamurthy <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

Author: agarg2008

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

@@ -558,7 +558,7 @@ static int gve_alloc_notify_blocks(struct gve_priv *priv)
 		block->priv = priv;
 		err = request_irq(priv->msix_vectors[msix_idx].vector,
 				  gve_is_gqi(priv) ? gve_intr : gve_intr_dqo,
-				  0, block->name, block);
+				  IRQF_NO_AUTOEN, block->name, block);
 		if (err) {
 			dev_err(&priv->pdev->dev,
 				"Failed to receive msix vector %d\n", i);

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

@@ -112,11 +112,13 @@ void gve_add_napi(struct gve_priv *priv, int ntfy_idx,
 
 	netif_napi_add_locked(priv->dev, &block->napi, gve_poll);
 	netif_napi_set_irq_locked(&block->napi, block->irq);
+	enable_irq(block->irq);
 }
 
 void gve_remove_napi(struct gve_priv *priv, int ntfy_idx)
 {
 	struct gve_notify_block *block = &priv->ntfy_blocks[ntfy_idx];
 
+	disable_irq(block->irq);
 	netif_napi_del_locked(&block->napi);
 }