KVM: VMX: Fold fallback path into triggering posted IRQ helper

Move the fallback "wake_up" path into the helper to trigger posted
interrupt helper now that the nested and non-nested paths are identical.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20211208015236.1616697-20-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Author: sean-jc

arch/x86/kvm/vmx/vmx.c

@@ -3931,7 +3931,7 @@ static void vmx_msr_filter_changed(struct kvm_vcpu *vcpu)
 	pt_update_intercept_for_msr(vcpu);
 }
 
-static inline bool kvm_vcpu_trigger_posted_interrupt(struct kvm_vcpu *vcpu,
+static inline void kvm_vcpu_trigger_posted_interrupt(struct kvm_vcpu *vcpu,
 						     int pi_vec)
 {
 #ifdef CONFIG_SMP
@@ -3962,10 +3962,15 @@ static inline bool kvm_vcpu_trigger_posted_interrupt(struct kvm_vcpu *vcpu,
 		 */
 
 		apic->send_IPI_mask(get_cpu_mask(vcpu->cpu), pi_vec);
-		return true;
+		return;
 	}
 #endif
-	return false;
+	/*
+	 * The vCPU isn't in the guest; wake the vCPU in case it is blocking,
+	 * otherwise do nothing as KVM will grab the highest priority pending
+	 * IRQ via ->sync_pir_to_irr() in vcpu_enter_guest().
+	 */
+	kvm_vcpu_wake_up(vcpu);
 }
 
 static int vmx_deliver_nested_posted_interrupt(struct kvm_vcpu *vcpu,
@@ -3995,8 +4000,7 @@ static int vmx_deliver_nested_posted_interrupt(struct kvm_vcpu *vcpu,
 		smp_mb__after_atomic();
 
 		/* the PIR and ON have been set by L1. */
-		if (!kvm_vcpu_trigger_posted_interrupt(vcpu, POSTED_INTR_NESTED_VECTOR))
-			kvm_vcpu_wake_up(vcpu);
+		kvm_vcpu_trigger_posted_interrupt(vcpu, POSTED_INTR_NESTED_VECTOR);
 		return 0;
 	}
 	return -1;
@@ -4033,9 +4037,7 @@ static int vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int vector)
 	 * guaranteed to see PID.ON=1 and sync the PIR to IRR if triggering a
 	 * posted interrupt "fails" because vcpu->mode != IN_GUEST_MODE.
 	 */
-	if (!kvm_vcpu_trigger_posted_interrupt(vcpu, POSTED_INTR_VECTOR))
-		kvm_vcpu_wake_up(vcpu);
-
+	kvm_vcpu_trigger_posted_interrupt(vcpu, POSTED_INTR_VECTOR);
 	return 0;
 }