diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 0be4df3..dda38db 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -482,8 +482,12 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 	/* Legacy IRQ descriptors are already allocated by the arch. */
 	if (gsi < NR_IRQS_LEGACY)
 		irq = gsi;
-	else
-		irq = irq_alloc_desc_at(gsi, -1);
+	else {
+		/* for x86, irq already get reserved for gsi */
+		irq = irq_realloc_desc_at(gsi, -1);
+		if (irq < 0)
+			irq = irq_alloc_desc_at(gsi, -1);
+	}
 
 	xen_irq_init(irq);