diff options
Diffstat (limited to 'arch/x86/kvm/i8254.c')
| -rw-r--r-- | arch/x86/kvm/i8254.c | 37 |
1 files changed, 31 insertions, 6 deletions
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 3eddae692c0..09ae841ff46 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -98,6 +98,32 @@ static int pit_get_gate(struct kvm *kvm, int channel) return kvm->arch.vpit->pit_state.channels[channel].gate; } +static s64 __kpit_elapsed(struct kvm *kvm) +{ + s64 elapsed; + ktime_t remaining; + struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; + + remaining = hrtimer_expires_remaining(&ps->pit_timer.timer); + if (ktime_to_ns(remaining) < 0) + remaining = ktime_set(0, 0); + + elapsed = ps->pit_timer.period; + if (ktime_to_ns(remaining) <= ps->pit_timer.period) + elapsed = ps->pit_timer.period - ktime_to_ns(remaining); + + return elapsed; +} + +static s64 kpit_elapsed(struct kvm *kvm, struct kvm_kpit_channel_state *c, + int channel) +{ + if (channel == 0) + return __kpit_elapsed(kvm); + + return ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time)); +} + static int pit_get_count(struct kvm *kvm, int channel) { struct kvm_kpit_channel_state *c = @@ -107,7 +133,7 @@ static int pit_get_count(struct kvm *kvm, int channel) WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); - t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time)); + t = kpit_elapsed(kvm, c, channel); d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC); switch (c->mode) { @@ -137,7 +163,7 @@ static int pit_get_out(struct kvm *kvm, int channel) WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); - t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time)); + t = kpit_elapsed(kvm, c, channel); d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC); switch (c->mode) { @@ -208,8 +234,6 @@ static int __pit_timer_fn(struct kvm_kpit_state *ps) wake_up_interruptible(&vcpu0->wq); hrtimer_add_expires_ns(&pt->timer, pt->period); - if (pt->period) - ps->channels[0].count_load_time = ktime_get(); return (pt->period == 0 ? 0 : 1); } @@ -305,11 +329,12 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val) if (val == 0) val = 0x10000; - ps->channels[channel].count_load_time = ktime_get(); ps->channels[channel].count = val; - if (channel != 0) + if (channel != 0) { + ps->channels[channel].count_load_time = ktime_get(); return; + } /* Two types of timer * mode 1 is one shot, mode 2 is period, otherwise del timer */ |