diff options
| -rw-r--r-- | virt/kvm/arm/arch_timer.c | 49 |
1 files changed, 39 insertions, 10 deletions
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index a9ad4fe3f68f..9aaa35dd9144 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -91,6 +91,8 @@ 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. @@ -98,10 +100,46 @@ 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; } @@ -176,8 +214,6 @@ 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)); @@ -197,14 +233,7 @@ 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) |