From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 29 Jun 2017 17:14:50 +0200
Subject: KVM: lapic: reorganize start_hv_timer
Patch-mainline: v4.13-rc1
Git-commit: 35ee9e48b9df6c7751e8f759a4deec5aed1463c3
References: bsc#1077761

There are many cases in which the hv timer must be canceled.  Split out
a new function to avoid duplication.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Alexander Graf <agraf@suse.de>
---
 arch/x86/kvm/lapic.c |   40 +++++++++++++++++++++++++++-------------
 1 file changed, 27 insertions(+), 13 deletions(-)

--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1505,24 +1505,38 @@
 	preempt_enable();
 }
 
-static bool start_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 (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))
+		return false;
+
+	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) && atomic_read(&ktimer->pending))
+		return false;
+	return true;
+}
 
-	if ((atomic_read(&apic->lapic_timer.pending) &&
-		!apic_lvtt_period(apic)) ||
-		kvm_x86_ops->set_hv_timer(apic->vcpu, tscdeadline)) {
+static bool start_hv_timer(struct kvm_lapic *apic)
+{
+	if (!__start_hv_timer(apic)) {
 		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);
-
-		/* In case the sw timer triggered in the window */
-		if (atomic_read(&apic->lapic_timer.pending) &&
-			!apic_lvtt_period(apic))
-			cancel_hv_timer(apic);
 	}
+
 	trace_kvm_hv_timer_state(apic->vcpu->vcpu_id,
 			apic->lapic_timer.hv_timer_in_use);
 	return apic->lapic_timer.hv_timer_in_use;