1 files changed, 36 insertions, 9 deletions

diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 6e54f35..98c95f2 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -85,13 +85,22 @@ static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+/*
+ * Work function for handling the backup timer that we schedule when a vcpu is
+ * no longer running, but had a timer programmed to fire in the future.
+ */
 static void kvm_timer_inject_irq_work(struct work_struct *work)
 {
 	struct kvm_vcpu *vcpu;
 
 	vcpu = container_of(work, struct kvm_vcpu, arch.timer_cpu.expired);
 	vcpu->arch.timer_cpu.armed = false;
-	kvm_timer_inject_irq(vcpu);
+
+	/*
+	 * If the vcpu is blocked we want to wake it up so that it will see
+	 * the timer has expired when entering the guest.
+	 */
+	kvm_vcpu_kick(vcpu);
 }
 
 static enum hrtimer_restart kvm_timer_expire(struct hrtimer *hrt)
@@ -102,6 +111,21 @@ static enum hrtimer_restart kvm_timer_expire(struct hrtimer *hrt)
 	return HRTIMER_NORESTART;
 }
 
+bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
+{
+	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+	cycle_t cval, now;
+
+	if ((timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) ||
+		!(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE))
+		return false;
+
+	cval = timer->cntv_cval;
+	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
+
+	return cval <= now;
+}
+
 /**
  * kvm_timer_flush_hwstate - prepare to move the virt timer to the cpu
  * @vcpu: The vcpu pointer
@@ -119,6 +143,13 @@ void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
 	 * populate the CPU timer again.
 	 */
 	timer_disarm(timer);
+
+	/*
+	 * If the timer expired while we were not scheduled, now is the time
+	 * to inject it.
+	 */
+	if (kvm_timer_should_fire(vcpu))
+		kvm_timer_inject_irq(vcpu);
 }
 
 /**
@@ -134,16 +165,9 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
 	cycle_t cval, now;
 	u64 ns;
 
-	if ((timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) ||
-		!(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE))
-		return;
-
-	cval = timer->cntv_cval;
-	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
-
 	BUG_ON(timer_is_armed(timer));
 
-	if (cval <= now) {
+	if (kvm_timer_should_fire(vcpu)) {
 		/*
 		 * Timer has already expired while we were not
 		 * looking. Inject the interrupt and carry on.
@@ -152,6 +176,9 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
 		return;
 	}
 
+	cval = timer->cntv_cval;
+	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
+
 	ns = cyclecounter_cyc2ns(timecounter->cc, cval - now, timecounter->mask,
 				 &timecounter->frac);
 	timer_arm(timer, ns);