diff options
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 39b58f56308b..3ee6bf35d1e4 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -631,6 +631,18 @@ static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer) } /* + * Translate a stimer expiry given in 100ns reference ticks into an + * an absolute deadline. Saturates on overflow. + */ +static ktime_t stimer_add_delta(ktime_t now, u64 delta_100ns) +{ + if (delta_100ns >= KTIME_MAX / 100) + return KTIME_MAX; + + return ktime_add_safe(now, 100 * delta_100ns); +} + +/* * stimer_start() assumptions: * a) stimer->count is not equal to 0 * b) stimer->config has HV_STIMER_ENABLE flag @@ -639,6 +651,7 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer) { u64 time_now; ktime_t ktime_now; + ktime_t deadline; time_now = get_time_ref_counter(hv_stimer_to_vcpu(stimer)->kvm); ktime_now = ktime_get(); @@ -661,10 +674,8 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer) stimer->index, time_now, stimer->exp_time); - hrtimer_start(&stimer->timer, - ktime_add_ns(ktime_now, - 100 * (stimer->exp_time - time_now)), - HRTIMER_MODE_ABS); + deadline = stimer_add_delta(ktime_now, stimer->exp_time - time_now); + hrtimer_start(&stimer->timer, deadline, HRTIMER_MODE_ABS); return 0; } stimer->exp_time = stimer->count; @@ -683,9 +694,9 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer) stimer->index, time_now, stimer->count); - hrtimer_start(&stimer->timer, - ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)), - HRTIMER_MODE_ABS); + deadline = stimer_add_delta(ktime_now, stimer->count - time_now); + hrtimer_start(&stimer->timer, deadline, HRTIMER_MODE_ABS); + return 0; } |