KVM: arm/arm64: vgic: Trust the LR state for HW IRQs

We were probing the physial distributor state for the active state of a
HW virtual IRQ, because we had seen evidence that the LR state was not
cleared when the guest deactivated a virtual interrupted.

However, this issue turned out to be a software bug in the GIC, which
was solved by: 84aab5e68c2a5e1e18d81ae8308c3ce25d501b29
(KVM: arm/arm64: arch_timer: Preserve physical dist. active
state on LR.active, 2015-11-24)

Therefore, get rid of the complexities and just look at the LR.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

virt/kvm/arm/vgic.c

@@ -1417,25 +1417,13 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
 static bool vgic_sync_hwirq(struct kvm_vcpu *vcpu, int lr, struct vgic_lr vlr)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
-	struct irq_phys_map *map;
-	bool phys_active;
 	bool level_pending;
-	int ret;
 
 	if (!(vlr.state & LR_HW))
 		return false;
 
-	map = vgic_irq_map_search(vcpu, vlr.irq);
-	BUG_ON(!map);
-
-	ret = irq_get_irqchip_state(map->irq,
-				    IRQCHIP_STATE_ACTIVE,
-				    &phys_active);
-
-	WARN_ON(ret);
-
-	if (phys_active)
-		return 0;
+	if (vlr.state & LR_STATE_ACTIVE)
+		return false;
 
 	spin_lock(&dist->lock);
 	level_pending = process_queued_irq(vcpu, lr, vlr);