KVM: x86: optimize some accesses to LVTT and SPIV

We mirror a subset of these registers in separate variables.
Using them directly should be faster.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/lapic.c

@@ -244,21 +244,17 @@ static inline int apic_lvt_vector(struct kvm_lapic *apic, int lvt_type)
 
 static inline int apic_lvtt_oneshot(struct kvm_lapic *apic)
 {
-	return ((kvm_apic_get_reg(apic, APIC_LVTT) &
-		apic->lapic_timer.timer_mode_mask) == APIC_LVT_TIMER_ONESHOT);
+	return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_ONESHOT;
 }
 
 static inline int apic_lvtt_period(struct kvm_lapic *apic)
 {
-	return ((kvm_apic_get_reg(apic, APIC_LVTT) &
-		apic->lapic_timer.timer_mode_mask) == APIC_LVT_TIMER_PERIODIC);
+	return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_PERIODIC;
 }
 
 static inline int apic_lvtt_tscdeadline(struct kvm_lapic *apic)
 {
-	return ((kvm_apic_get_reg(apic, APIC_LVTT) &
-		apic->lapic_timer.timer_mode_mask) ==
-			APIC_LVT_TIMER_TSCDEADLINE);
+	return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_TSCDEADLINE;
 }
 
 static inline int apic_lvt_nmi_mode(u32 lvt_val)

arch/x86/kvm/lapic.h

@@ -121,11 +121,11 @@ static inline int kvm_apic_hw_enabled(struct kvm_lapic *apic)
 
 extern struct static_key_deferred apic_sw_disabled;
 
-static inline int kvm_apic_sw_enabled(struct kvm_lapic *apic)
+static inline bool kvm_apic_sw_enabled(struct kvm_lapic *apic)
 {
 	if (static_key_false(&apic_sw_disabled.key))
-		return kvm_apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_APIC_ENABLED;
-	return APIC_SPIV_APIC_ENABLED;
+		return apic->sw_enabled;
+	return true;
 }
 
 static inline bool kvm_apic_present(struct kvm_vcpu *vcpu)