KVM: x86: Introduce helper to check if vector is set in Hyper-V SynIC

As a preparation to making Hyper-V emulation optional, create a dedicated
kvm_hv_synic_has_vector() helper to avoid extra ifdefs in lapic.c.

No functional change intended.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Tested-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20231205103630.1391318-6-vkuznets@redhat.comSigned-off-by: Sean Christopherson <seanjc@google.com>

arch/x86/kvm/hyperv.h

@@ -105,6 +105,11 @@ int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vcpu_id, u32 sint);
 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector);
 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages);
 
+static inline bool kvm_hv_synic_has_vector(struct kvm_vcpu *vcpu, int vector)
+{
+	return to_hv_vcpu(vcpu) && test_bit(vector, to_hv_synic(vcpu)->vec_bitmap);
+}
+
 static inline bool kvm_hv_synic_auto_eoi_set(struct kvm_vcpu *vcpu, int vector)
 {
 	return to_hv_vcpu(vcpu) &&

arch/x86/kvm/lapic.c

@@ -1475,8 +1475,7 @@ static int apic_set_eoi(struct kvm_lapic *apic)
 	apic_clear_isr(vector, apic);
 	apic_update_ppr(apic);
 
-	if (to_hv_vcpu(apic->vcpu) &&
-	    test_bit(vector, to_hv_synic(apic->vcpu)->vec_bitmap))
+	if (kvm_hv_synic_has_vector(apic->vcpu, vector))
 		kvm_hv_synic_send_eoi(apic->vcpu, vector);
 
 	kvm_ioapic_send_eoi(apic, vector);