struct kvm_kpit_channel_state *c =
&kvm->arch.vpit->pit_state.channels[channel];
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
switch (c->mode) {
default:
case 0:
static int pit_get_gate(struct kvm *kvm, int channel)
{
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
return kvm->arch.vpit->pit_state.channels[channel].gate;
}
s64 d, t;
int counter;
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
t = kpit_elapsed(kvm, c, channel);
d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
s64 d, t;
int out;
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
t = kpit_elapsed(kvm, c, channel);
d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
struct kvm_kpit_channel_state *c =
&kvm->arch.vpit->pit_state.channels[channel];
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
if (!c->count_latched) {
c->latched_count = pit_get_count(kvm, channel);
c->count_latched = c->rw_mode;
struct kvm_kpit_channel_state *c =
&kvm->arch.vpit->pit_state.channels[channel];
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
if (!c->status_latched) {
/* TODO: Return NULL COUNT (bit 6). */
c->status = ((pit_get_out(kvm, channel) << 7) |
{
struct kvm_kpit_state *ps = container_of(kian, struct kvm_kpit_state,
irq_ack_notifier);
- int value;
-
- spin_lock(&ps->inject_lock);
- value = atomic_dec_return(&ps->pending);
- if (value < 0)
- /* spurious acks can be generated if, for example, the
- * PIC is being reset. Handle it gracefully here
- */
- atomic_inc(&ps->pending);
- else if (value > 0)
- /* in this case, we had multiple outstanding pit interrupts
- * that we needed to inject. Reinject
- */
+
+ atomic_set(&ps->irq_ack, 1);
+ /* irq_ack should be set before pending is read. Order accesses with
+ * inc(pending) in pit_timer_fn and xchg(irq_ack, 0) in pit_do_work.
+ */
+ smp_mb();
+ if (atomic_dec_if_positive(&ps->pending) > 0 && ps->reinject)
queue_kthread_work(&ps->pit->worker, &ps->pit->expired);
- ps->irq_ack = 1;
- spin_unlock(&ps->inject_lock);
}
void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
struct kvm_vcpu *vcpu;
int i;
struct kvm_kpit_state *ps = &pit->pit_state;
- int inject = 0;
- /* Try to inject pending interrupts when
- * last one has been acked.
+ if (ps->reinject && !atomic_xchg(&ps->irq_ack, 0))
+ return;
+
+ kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1, false);
+ kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0, false);
+
+ /*
+ * Provides NMI watchdog support via Virtual Wire mode.
+ * The route is: PIT -> LVT0 in NMI mode.
+ *
+ * Note: Our Virtual Wire implementation does not follow
+ * the MP specification. We propagate a PIT interrupt to all
+ * VCPUs and only when LVT0 is in NMI mode. The interrupt can
+ * also be simultaneously delivered through PIC and IOAPIC.
*/
- spin_lock(&ps->inject_lock);
- if (ps->irq_ack) {
- ps->irq_ack = 0;
- inject = 1;
- }
- spin_unlock(&ps->inject_lock);
- if (inject) {
- kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1, false);
- kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0, false);
-
- /*
- * Provides NMI watchdog support via Virtual Wire mode.
- * The route is: PIT -> PIC -> LVT0 in NMI mode.
- *
- * Note: Our Virtual Wire implementation is simplified, only
- * propagating PIT interrupts to all VCPUs when they have set
- * LVT0 to NMI delivery. Other PIC interrupts are just sent to
- * VCPU0, and only if its LVT0 is in EXTINT mode.
- */
- if (atomic_read(&kvm->arch.vapics_in_nmi_mode) > 0)
- kvm_for_each_vcpu(i, vcpu, kvm)
- kvm_apic_nmi_wd_deliver(vcpu);
- }
+ if (atomic_read(&kvm->arch.vapics_in_nmi_mode) > 0)
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ kvm_apic_nmi_wd_deliver(vcpu);
}
static enum hrtimer_restart pit_timer_fn(struct hrtimer *data)
struct kvm_kpit_state *ps = container_of(data, struct kvm_kpit_state, timer);
struct kvm_pit *pt = ps->kvm->arch.vpit;
- if (ps->reinject || !atomic_read(&ps->pending)) {
+ if (ps->reinject)
atomic_inc(&ps->pending);
- queue_kthread_work(&pt->worker, &pt->expired);
- }
+
+ queue_kthread_work(&pt->worker, &pt->expired);
if (ps->is_periodic) {
hrtimer_add_expires_ns(&ps->timer, ps->period);
return HRTIMER_NORESTART;
}
+static inline void kvm_pit_reset_reinject(struct kvm_pit *pit)
+{
+ atomic_set(&pit->pit_state.pending, 0);
+ atomic_set(&pit->pit_state.irq_ack, 1);
+}
+
static void create_pit_timer(struct kvm *kvm, u32 val, int is_period)
{
struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
ps->timer.function = pit_timer_fn;
ps->kvm = ps->pit->kvm;
- atomic_set(&ps->pending, 0);
- ps->irq_ack = 1;
+ kvm_pit_reset_reinject(ps->pit);
/*
* Do not allow the guest to program periodic timers with small
{
struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
- WARN_ON(!mutex_is_locked(&ps->lock));
-
pr_debug("load_count val is %d, channel is %d\n", val, channel);
/*
void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start)
{
u8 saved_mode;
+
+ WARN_ON_ONCE(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
+
if (hpet_legacy_start) {
/* save existing mode for later reenablement */
WARN_ON(channel != 0);
}
mutex_unlock(&pit->pit_state.lock);
- atomic_set(&pit->pit_state.pending, 0);
- pit->pit_state.irq_ack = 1;
+ kvm_pit_reset_reinject(pit);
}
static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask)
{
struct kvm_pit *pit = container_of(kimn, struct kvm_pit, mask_notifier);
- if (!mask) {
- atomic_set(&pit->pit_state.pending, 0);
- pit->pit_state.irq_ack = 1;
- }
+ if (!mask)
+ kvm_pit_reset_reinject(pit);
}
static const struct kvm_io_device_ops pit_dev_ops = {
mutex_init(&pit->pit_state.lock);
mutex_lock(&pit->pit_state.lock);
- spin_lock_init(&pit->pit_state.inject_lock);
pid = get_pid(task_tgid(current));
pid_nr = pid_vnr(pid);
projects / deliverable / linux.git / blobdiff