diff options
Diffstat (limited to 'virt/kvm/kvm_main.c')
| -rw-r--r-- | virt/kvm/kvm_main.c | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 68e3f1ec167..277ea7f39fc 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -173,7 +173,6 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) assigned_dev->host_irq_disabled = false; } mutex_unlock(&assigned_dev->kvm->lock); - kvm_put_kvm(assigned_dev->kvm); } static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id) @@ -181,8 +180,6 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id) struct kvm_assigned_dev_kernel *assigned_dev = (struct kvm_assigned_dev_kernel *) dev_id; - kvm_get_kvm(assigned_dev->kvm); - schedule_work(&assigned_dev->interrupt_work); disable_irq_nosync(irq); @@ -213,6 +210,7 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian) } } +/* The function implicit hold kvm->lock mutex due to cancel_work_sync() */ static void kvm_free_assigned_irq(struct kvm *kvm, struct kvm_assigned_dev_kernel *assigned_dev) { @@ -228,11 +226,24 @@ static void kvm_free_assigned_irq(struct kvm *kvm, if (!assigned_dev->irq_requested_type) return; - if (cancel_work_sync(&assigned_dev->interrupt_work)) - /* We had pending work. That means we will have to take - * care of kvm_put_kvm. - */ - kvm_put_kvm(kvm); + /* + * In kvm_free_device_irq, cancel_work_sync return true if: + * 1. work is scheduled, and then cancelled. + * 2. work callback is executed. + * + * The first one ensured that the irq is disabled and no more events + * would happen. But for the second one, the irq may be enabled (e.g. + * for MSI). So we disable irq here to prevent further events. + * + * Notice this maybe result in nested disable if the interrupt type is + * INTx, but it's OK for we are going to free it. + * + * If this function is a part of VM destroy, please ensure that till + * now, the kvm state is still legal for probably we also have to wait + * interrupt_work done. + */ + disable_irq_nosync(assigned_dev->host_irq); + cancel_work_sync(&assigned_dev->interrupt_work); free_irq(assigned_dev->host_irq, (void *)assigned_dev); |