1 files changed, 64 insertions, 52 deletions

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index d24c874..2819d4c1 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1495,6 +1495,7 @@ EXPORT_SYMBOL_GPL(kvm_lapic_hv_timer_in_use);
 
 static void cancel_hv_timer(struct kvm_lapic *apic)
 {
+	WARN_ON(!apic->lapic_timer.hv_timer_in_use);
 	preempt_disable();
 	kvm_x86_ops->cancel_hv_timer(apic->vcpu);
 	apic->lapic_timer.hv_timer_in_use = false;
@@ -1503,25 +1504,56 @@ static void cancel_hv_timer(struct kvm_lapic *apic)
 
 static bool start_hv_timer(struct kvm_lapic *apic)
 {
-	u64 tscdeadline = apic->lapic_timer.tscdeadline;
+	struct kvm_timer *ktimer = &apic->lapic_timer;
+	int r;
 
-	if ((atomic_read(&apic->lapic_timer.pending) &&
-		!apic_lvtt_period(apic)) ||
-		kvm_x86_ops->set_hv_timer(apic->vcpu, tscdeadline)) {
-		if (apic->lapic_timer.hv_timer_in_use)
-			cancel_hv_timer(apic);
-	} else {
-		apic->lapic_timer.hv_timer_in_use = true;
-		hrtimer_cancel(&apic->lapic_timer.timer);
+	if (!kvm_x86_ops->set_hv_timer)
+		return false;
+
+	if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))
+		return false;
 
-		/* In case the sw timer triggered in the window */
-		if (atomic_read(&apic->lapic_timer.pending) &&
-			!apic_lvtt_period(apic))
-			cancel_hv_timer(apic);
+	r = kvm_x86_ops->set_hv_timer(apic->vcpu, ktimer->tscdeadline);
+	if (r < 0)
+		return false;
+
+	ktimer->hv_timer_in_use = true;
+	hrtimer_cancel(&ktimer->timer);
+
+	/*
+	 * Also recheck ktimer->pending, in case the sw timer triggered in
+	 * the window.  For periodic timer, leave the hv timer running for
+	 * simplicity, and the deadline will be recomputed on the next vmexit.
+	 */
+	if (!apic_lvtt_period(apic) && (r || atomic_read(&ktimer->pending))) {
+		if (r)
+			apic_timer_expired(apic);
+		return false;
 	}
-	trace_kvm_hv_timer_state(apic->vcpu->vcpu_id,
-			apic->lapic_timer.hv_timer_in_use);
-	return apic->lapic_timer.hv_timer_in_use;
+
+	trace_kvm_hv_timer_state(apic->vcpu->vcpu_id, true);
+	return true;
+}
+
+static void start_sw_timer(struct kvm_lapic *apic)
+{
+	struct kvm_timer *ktimer = &apic->lapic_timer;
+	if (apic->lapic_timer.hv_timer_in_use)
+		cancel_hv_timer(apic);
+	if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))
+		return;
+
+	if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic))
+		start_sw_period(apic);
+	else if (apic_lvtt_tscdeadline(apic))
+		start_sw_tscdeadline(apic);
+	trace_kvm_hv_timer_state(apic->vcpu->vcpu_id, false);
+}
+
+static void restart_apic_timer(struct kvm_lapic *apic)
+{
+	if (!start_hv_timer(apic))
+		start_sw_timer(apic);
 }
 
 void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu)
@@ -1535,19 +1567,14 @@ void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu)
 
 	if (apic_lvtt_period(apic) && apic->lapic_timer.period) {
 		advance_periodic_target_expiration(apic);
-		if (!start_hv_timer(apic))
-			start_sw_period(apic);
+		restart_apic_timer(apic);
 	}
 }
 EXPORT_SYMBOL_GPL(kvm_lapic_expired_hv_timer);
 
 void kvm_lapic_switch_to_hv_timer(struct kvm_vcpu *vcpu)
 {
-	struct kvm_lapic *apic = vcpu->arch.apic;
-
-	WARN_ON(apic->lapic_timer.hv_timer_in_use);
-
-	start_hv_timer(apic);
+	restart_apic_timer(vcpu->arch.apic);
 }
 EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_hv_timer);
 
@@ -1556,33 +1583,28 @@ void kvm_lapic_switch_to_sw_timer(struct kvm_vcpu *vcpu)
 	struct kvm_lapic *apic = vcpu->arch.apic;
 
 	/* Possibly the TSC deadline timer is not enabled yet */
-	if (!apic->lapic_timer.hv_timer_in_use)
-		return;
-
-	cancel_hv_timer(apic);
+	if (apic->lapic_timer.hv_timer_in_use)
+		start_sw_timer(apic);
+}
+EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_sw_timer);
 
-	if (atomic_read(&apic->lapic_timer.pending))
-		return;
+void kvm_lapic_restart_hv_timer(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
 
-	if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic))
-		start_sw_period(apic);
-	else if (apic_lvtt_tscdeadline(apic))
-		start_sw_tscdeadline(apic);
+	WARN_ON(!apic->lapic_timer.hv_timer_in_use);
+	restart_apic_timer(apic);
 }
-EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_sw_timer);
 
 static void start_apic_timer(struct kvm_lapic *apic)
 {
 	atomic_set(&apic->lapic_timer.pending, 0);
 
-	if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) {
-		if (set_target_expiration(apic) &&
-			!(kvm_x86_ops->set_hv_timer && start_hv_timer(apic)))
-			start_sw_period(apic);
-	} else if (apic_lvtt_tscdeadline(apic)) {
-		if (!(kvm_x86_ops->set_hv_timer && start_hv_timer(apic)))
-			start_sw_tscdeadline(apic);
-	}
+	if ((apic_lvtt_period(apic) || apic_lvtt_oneshot(apic))
+	    && !set_target_expiration(apic))
+		return;
+
+	restart_apic_timer(apic);
 }
 
 static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
@@ -1813,16 +1835,6 @@ void kvm_free_lapic(struct kvm_vcpu *vcpu)
  * LAPIC interface
  *----------------------------------------------------------------------
  */
-u64 kvm_get_lapic_target_expiration_tsc(struct kvm_vcpu *vcpu)
-{
-	struct kvm_lapic *apic = vcpu->arch.apic;
-
-	if (!lapic_in_kernel(vcpu))
-		return 0;
-
-	return apic->lapic_timer.tscdeadline;
-}
-
 u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;