diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 831d963451d8..722692e2f745 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1240,6 +1240,15 @@ struct kvm_device_ops { */ void (*destroy)(struct kvm_device *dev); + /* + * Release is an alternative method to free the device. It is + * called when the device file descriptor is closed. Once + * release is called, the destroy method will not be called + * anymore as the device is removed from the device list of + * the VM. kvm->lock is held. + */ + void (*release)(struct kvm_device *dev); + int (*set_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); int (*get_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); int (*has_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ea2018ae1cd7..ea2619d5ca98 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2938,6 +2938,19 @@ static int kvm_device_release(struct inode *inode, struct file *filp) struct kvm_device *dev = filp->private_data; struct kvm *kvm = dev->kvm; + if (!dev) + return -ENODEV; + + if (dev->kvm != kvm) + return -EPERM; + + if (dev->ops->release) { + mutex_lock(&kvm->lock); + list_del(&dev->vm_node); + dev->ops->release(dev); + mutex_unlock(&kvm->lock); + } + kvm_put_kvm(kvm); return 0; }