KVM: VMX: Use posted interrupt to deliver virtual interrupt

If posted interrupt is avaliable, then uses it to inject virtual
interrupt to guest.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/lapic.c

@@ -353,6 +353,7 @@ static inline int apic_find_highest_irr(struct kvm_lapic *apic)
 	if (!apic->irr_pending)
 		return -1;
 
+	kvm_x86_ops->sync_pir_to_irr(apic->vcpu);
 	result = apic_search_irr(apic);
 	ASSERT(result == -1 || result >= 16);
 
@@ -683,18 +684,25 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 		if (dest_map)
 			__set_bit(vcpu->vcpu_id, dest_map);
 
-		result = !apic_test_and_set_irr(vector, apic);
-		trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode,
-					  trig_mode, vector, !result);
-		if (!result) {
-			if (trig_mode)
-				apic_debug("level trig mode repeatedly for "
-						"vector %d", vector);
-			break;
-		}
+		if (kvm_x86_ops->deliver_posted_interrupt) {
+			result = 1;
+			kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
+		} else {
+			result = !apic_test_and_set_irr(vector, apic);
 
-		kvm_make_request(KVM_REQ_EVENT, vcpu);
-		kvm_vcpu_kick(vcpu);
+			if (!result) {
+				if (trig_mode)
+					apic_debug("level trig mode repeatedly "
+						"for vector %d", vector);
+				goto out;
+			}
+
+			kvm_make_request(KVM_REQ_EVENT, vcpu);
+			kvm_vcpu_kick(vcpu);
+		}
+out:
+		trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode,
+				trig_mode, vector, !result);
 		break;
 
 	case APIC_DM_REMRD:

arch/x86/kvm/vmx.c

@@ -84,7 +84,7 @@ module_param(vmm_exclusive, bool, S_IRUGO);
 static bool __read_mostly fasteoi = 1;
 module_param(fasteoi, bool, S_IRUGO);
 
-static bool __read_mostly enable_apicv;
+static bool __read_mostly enable_apicv = 1;
 module_param(enable_apicv, bool, S_IRUGO);
 
 /*

arch/x86/kvm/x86.c

@@ -2692,6 +2692,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
 				    struct kvm_lapic_state *s)
 {
+	kvm_x86_ops->sync_pir_to_irr(vcpu);
 	memcpy(s->regs, vcpu->arch.apic->regs, sizeof *s);
 
 	return 0;