Discard policy doesn't rely on information from notifiers, so we don't need to register notifiers unconditionally.
Use of ps->lock doesn't make sense, but isn't any worse than before. Signed-off-by: Radim Krčmář <[email protected]> --- arch/x86/kvm/i8254.c | 44 ++++++++++++++++++++++++++++++-------------- arch/x86/kvm/i8254.h | 1 + arch/x86/kvm/x86.c | 6 +++--- 3 files changed, 34 insertions(+), 17 deletions(-) diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index fc554fbf71a7..f1dfc250bbe0 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -237,9 +237,6 @@ static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian) struct kvm_kpit_state *ps = container_of(kian, struct kvm_kpit_state, irq_ack_notifier); - if (!ps->reinject) - return; - atomic_set(&ps->irq_ack, 1); if (atomic_add_unless(&ps->pending, -1, 0)) /* in this case, we had multiple outstanding pit interrupts @@ -708,14 +705,13 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) hrtimer_init(&pit_state->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); pit_state->irq_ack_notifier.gsi = 0; pit_state->irq_ack_notifier.irq_acked = kvm_pit_ack_irq; - kvm_register_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); - pit_state->reinject = true; mutex_unlock(&pit->pit_state.lock); - kvm_pit_reset(pit); - pit->mask_notifier.func = pit_mask_notifer; - kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); + + kvm_pit_set_reinject(pit, true); + + kvm_pit_reset(pit); kvm_iodevice_init(&pit->dev, &pit_dev_ops); ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, KVM_PIT_BASE_ADDRESS, @@ -738,14 +734,37 @@ fail_unregister: kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->dev); fail: - kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier); - kvm_unregister_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); + kvm_pit_set_reinject(pit, false); kvm_free_irq_source_id(kvm, pit->irq_source_id); kthread_stop(pit->worker_task); kfree(pit); return NULL; } +void kvm_pit_set_reinject(struct kvm_pit *pit, bool reinject) +{ + /* Implicit BUG on NULL dereference. */ + struct kvm_kpit_state *ps = &pit->pit_state; + struct kvm *kvm = pit->kvm; + + mutex_lock(&ps->lock); + + if (ps->reinject == reinject) + goto out; + + ps->reinject = reinject; + if (reinject) { + kvm_pit_reset_reinject(pit); + kvm_register_irq_ack_notifier(kvm, &ps->irq_ack_notifier); + kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); + } else { + kvm_unregister_irq_ack_notifier(kvm, &ps->irq_ack_notifier); + kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier); + } +out: + mutex_unlock(&ps->lock); +} + void kvm_free_pit(struct kvm *kvm) { struct hrtimer *timer; @@ -754,10 +773,7 @@ void kvm_free_pit(struct kvm *kvm) kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &kvm->arch.vpit->dev); kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &kvm->arch.vpit->speaker_dev); - kvm_unregister_irq_mask_notifier(kvm, 0, - &kvm->arch.vpit->mask_notifier); - kvm_unregister_irq_ack_notifier(kvm, - &kvm->arch.vpit->pit_state.irq_ack_notifier); + kvm_pit_set_reinject(kvm->arch.vpit, false); mutex_lock(&kvm->arch.vpit->pit_state.lock); timer = &kvm->arch.vpit->pit_state.timer; hrtimer_cancel(timer); diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h index f8cf4b84f435..7ac94bc0799f 100644 --- a/arch/x86/kvm/i8254.h +++ b/arch/x86/kvm/i8254.h @@ -60,5 +60,6 @@ void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_s struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags); void kvm_free_pit(struct kvm *kvm); void kvm_pit_reset(struct kvm_pit *pit); +void kvm_pit_set_reinject(struct kvm_pit *pit, bool reinject); #endif diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5b937fdebc66..6bc03141e809 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3652,9 +3652,9 @@ static int kvm_vm_ioctl_reinject(struct kvm *kvm, { if (!kvm->arch.vpit) return -ENXIO; - mutex_lock(&kvm->arch.vpit->pit_state.lock); - kvm->arch.vpit->pit_state.reinject = control->pit_reinject; - mutex_unlock(&kvm->arch.vpit->pit_state.lock); + + kvm_pit_set_reinject(kvm->arch.vpit, control->pit_reinject); + return 0; } -- 2.7.0
