KVM: x86: fix APIC physical destination wrapping

x2apic allows destinations > 0xff and we don't want them delivered to
lower APICs.  They are correctly handled by doing nothing.
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/lapic.c

@@ -693,7 +693,10 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
 	ret = true;
 
 	if (irq->dest_mode == 0) { /* physical mode */
-		dst = &map->phys_map[irq->dest_id & 0xff];
+		if (irq->dest_id >= ARRAY_SIZE(map->phys_map))
+			goto out;
+
+		dst = &map->phys_map[irq->dest_id];
 	} else {
 		u32 mda = irq->dest_id << (32 - map->ldr_bits);