ARM: KVM: vgic: force EOIed LRs to the empty state

The VGIC doesn't guarantee that an EOIed LR that has been configured
to generate a maintenance interrupt will appear as empty.

While the code recovers from this situation, it is better to clean
the LR and flag it as empty so it can be quickly recycled.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
index c9a1731..76ea1aa 100644
--- a/arch/arm/kvm/vgic.c
+++ b/arch/arm/kvm/vgic.c
@@ -883,8 +883,7 @@
 			  lr, irq, vgic_cpu->vgic_lr[lr]);
 		BUG_ON(!test_bit(lr, vgic_cpu->lr_used));
 		vgic_cpu->vgic_lr[lr] |= GICH_LR_PENDING_BIT;
-
-		goto out;
+		return true;
 	}
 
 	/* Try to use another LR for this interrupt */
@@ -898,7 +897,6 @@
 	vgic_cpu->vgic_irq_lr_map[irq] = lr;
 	set_bit(lr, vgic_cpu->lr_used);
 
-out:
 	if (!vgic_irq_is_edge(vcpu, irq))
 		vgic_cpu->vgic_lr[lr] |= GICH_LR_EOI;
 
@@ -1054,6 +1052,13 @@
 			} else {
 				vgic_cpu_irq_clear(vcpu, irq);
 			}
+
+			/*
+			 * Despite being EOIed, the LR may not have
+			 * been marked as empty.
+			 */
+			set_bit(lr, (unsigned long *)vgic_cpu->vgic_elrsr);
+			vgic_cpu->vgic_lr[lr] &= ~GICH_LR_ACTIVE_BIT;
 		}
 	}