1 files changed, 60 insertions, 49 deletions

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index c13bb92d3157..4d6f0d293ee2 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -98,6 +98,37 @@ 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;
+
+        /*
+         * The Counter does not stop when it reaches zero. In
+         * Modes 0, 1, 4, and 5 the Counter ``wraps around'' to
+         * the highest count, either FFFF hex for binary counting
+         * or 9999 for BCD counting, and continues counting.
+         * Modes 2 and 3 are periodic; the Counter reloads
+         * itself with the initial count and continues counting
+         * from there.
+         */
+        remaining = hrtimer_expires_remaining(&ps->pit_timer.timer);
+        elapsed = ps->pit_timer.period - ktime_to_ns(remaining);
+        elapsed = mod_64(elapsed, ps->pit_timer.period);
+
+        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 +138,7 @@ 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 +168,7 @@ 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) {
@@ -193,28 +224,6 @@ static void pit_latch_status(struct kvm *kvm, int channel)
         }
 }
 
-static int __pit_timer_fn(struct kvm_kpit_state *ps)
-{
-        struct kvm_vcpu *vcpu0 = ps->pit->kvm->vcpus[0];
-        struct kvm_kpit_timer *pt = &ps->pit_timer;
-
-        if (!atomic_inc_and_test(&pt->pending))
-                set_bit(KVM_REQ_PENDING_TIMER, &vcpu0->requests);
-
-        if (!pt->reinject)
-                atomic_set(&pt->pending, 1);
-
-        if (vcpu0 && waitqueue_active(&vcpu0->wq))
-                wake_up_interruptible(&vcpu0->wq);
-
-        hrtimer_add_expires_ns(&pt->timer, pt->period);
-        pt->scheduled = hrtimer_get_expires_ns(&pt->timer);
-        if (pt->period)
-                ps->channels[0].count_load_time = ktime_get();
-
-        return (pt->period == 0 ? 0 : 1);
-}
-
 int pit_has_pending_timer(struct kvm_vcpu *vcpu)
 {
         struct kvm_pit *pit = vcpu->kvm->arch.vpit;
@@ -235,21 +244,6 @@ static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian)
         spin_unlock(&ps->inject_lock);
 }
 
-static enum hrtimer_restart pit_timer_fn(struct hrtimer *data)
-{
-        struct kvm_kpit_state *ps;
-        int restart_timer = 0;
-
-        ps = container_of(data, struct kvm_kpit_state, pit_timer.timer);
-
-        restart_timer = __pit_timer_fn(ps);
-
-        if (restart_timer)
-                return HRTIMER_RESTART;
-        else
-                return HRTIMER_NORESTART;
-}
-
 void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
 {
         struct kvm_pit *pit = vcpu->kvm->arch.vpit;
@@ -263,15 +257,26 @@ void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
                 hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }
 
-static void destroy_pit_timer(struct kvm_kpit_timer *pt)
+static void destroy_pit_timer(struct kvm_timer *pt)
 {
         pr_debug("pit: execute del timer!\n");
         hrtimer_cancel(&pt->timer);
 }
 
+static bool kpit_is_periodic(struct kvm_timer *ktimer)
+{
+        struct kvm_kpit_state *ps = container_of(ktimer, struct kvm_kpit_state,
+                                                 pit_timer);
+        return ps->is_periodic;
+}
+
+static struct kvm_timer_ops kpit_ops = {
+        .is_periodic = kpit_is_periodic,
+};
+
 static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period)
 {
-        struct kvm_kpit_timer *pt = &ps->pit_timer;
+        struct kvm_timer *pt = &ps->pit_timer;
         s64 interval;
 
         interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ);
@@ -280,8 +285,14 @@ static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period)
 
         /* TODO The new value only affected after the retriggered */
         hrtimer_cancel(&pt->timer);
-        pt->period = (is_period == 0) ? 0 : interval;
-        pt->timer.function = pit_timer_fn;
+        pt->period = interval;
+        ps->is_periodic = is_period;
+
+        pt->timer.function = kvm_timer_fn;
+        pt->t_ops = &kpit_ops;
+        pt->kvm = ps->pit->kvm;
+        pt->vcpu_id = 0;
+
         atomic_set(&pt->pending, 0);
         ps->irq_ack = 1;
 
@@ -298,23 +309,23 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val)
         pr_debug("pit: load_count val is %d, channel is %d\n", val, channel);
 
         /*
-         * Though spec said the state of 8254 is undefined after power-up,
-         * seems some tricky OS like Windows XP depends on IRQ0 interrupt
-         * when booting up.
-         * So here setting initialize rate for it, and not a specific number
+         * The largest possible initial count is 0; this is equivalent
+         * to 216 for binary counting and 104 for BCD counting.
          */
         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 */
         switch (ps->channels[0].mode) {
+        case 0:
         case 1:
         /* FIXME: enhance mode 4 precision */
         case 4: