Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / virt / kvm / arm / arch_timer.c

diff --git a/kernel/virt/kvm/arm/arch_timer.c b/kernel/virt/kvm/arm/arch_timer.c
index ea60646..a7b9022 100644 (file)
--- a/kernel/virt/kvm/arm/arch_timer.c
+++ b/kernel/virt/kvm/arm/arch_timer.c
@@ -86,6 +86,8 @@ static void kvm_timer_inject_irq_work(struct work_struct *work)
        vcpu = container_of(work, struct kvm_vcpu, arch.timer_cpu.expired);
        vcpu->arch.timer_cpu.armed = false;
 
+       WARN_ON(!kvm_timer_should_fire(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.
@@ -93,10 +95,46 @@ static void kvm_timer_inject_irq_work(struct work_struct *work)
        kvm_vcpu_kick(vcpu);
 }
 
+static u64 kvm_timer_compute_delta(struct kvm_vcpu *vcpu)
+{
+       cycle_t cval, now;
+
+       cval = vcpu->arch.timer_cpu.cntv_cval;
+       now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
+
+       if (now < cval) {
+               u64 ns;
+
+               ns = cyclecounter_cyc2ns(timecounter->cc,
+                                        cval - now,
+                                        timecounter->mask,
+                                        &timecounter->frac);
+               return ns;
+       }
+
+       return 0;
+}
+
 static enum hrtimer_restart kvm_timer_expire(struct hrtimer *hrt)
 {
        struct arch_timer_cpu *timer;
+       struct kvm_vcpu *vcpu;
+       u64 ns;
+
        timer = container_of(hrt, struct arch_timer_cpu, timer);
+       vcpu = container_of(timer, struct kvm_vcpu, arch.timer_cpu);
+
+       /*
+        * Check that the timer has really expired from the guest's
+        * PoV (NTP on the host may have forced it to expire
+        * early). If we should have slept longer, restart it.
+        */
+       ns = kvm_timer_compute_delta(vcpu);
+       if (unlikely(ns)) {
+               hrtimer_forward_now(hrt, ns_to_ktime(ns));
+               return HRTIMER_RESTART;
+       }
+
        queue_work(wqueue, &timer->expired);
        return HRTIMER_NORESTART;
 }
@@ -170,8 +208,6 @@ static int kvm_timer_update_state(struct kvm_vcpu *vcpu)
 void kvm_timer_schedule(struct kvm_vcpu *vcpu)
 {
        struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
-       u64 ns;
-       cycle_t cval, now;
 
        BUG_ON(timer_is_armed(timer));
 
@@ -191,14 +227,7 @@ void kvm_timer_schedule(struct kvm_vcpu *vcpu)
                return;
 
        /*  The timer has not yet expired, schedule a background timer */
-       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);
+       timer_arm(timer, kvm_timer_compute_delta(vcpu));
 }
 
 void kvm_timer_unschedule(struct kvm_vcpu *vcpu)