diff options
| -rw-r--r-- | drivers/vfio/vfio.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 1758d96f43f4..4261eeec9e73 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -76,6 +76,7 @@ struct vfio_group { atomic_t opened; enum vfio_group_type type; unsigned int dev_counter; + struct rw_semaphore group_rwsem; struct kvm *kvm; struct blocking_notifier_head notifier; }; @@ -360,6 +361,7 @@ static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group, group->cdev.owner = THIS_MODULE; refcount_set(&group->users, 1); + init_rwsem(&group->group_rwsem); INIT_LIST_HEAD(&group->device_list); mutex_init(&group->device_lock); group->iommu_group = iommu_group; @@ -1694,9 +1696,11 @@ void vfio_file_set_kvm(struct file *file, struct kvm *kvm) if (file->f_op != &vfio_group_fops) return; + down_write(&group->group_rwsem); group->kvm = kvm; blocking_notifier_call_chain(&group->notifier, VFIO_GROUP_NOTIFY_SET_KVM, kvm); + up_write(&group->group_rwsem); } EXPORT_SYMBOL_GPL(vfio_file_set_kvm); @@ -2004,15 +2008,22 @@ static int vfio_register_group_notifier(struct vfio_group *group, return -EINVAL; ret = blocking_notifier_chain_register(&group->notifier, nb); + if (ret) + return ret; /* * The attaching of kvm and vfio_group might already happen, so * here we replay once upon registration. */ - if (!ret && set_kvm && group->kvm) - blocking_notifier_call_chain(&group->notifier, - VFIO_GROUP_NOTIFY_SET_KVM, group->kvm); - return ret; + if (set_kvm) { + down_read(&group->group_rwsem); + if (group->kvm) + blocking_notifier_call_chain(&group->notifier, + VFIO_GROUP_NOTIFY_SET_KVM, + group->kvm); + up_read(&group->group_rwsem); + } + return 0; } int vfio_register_notifier(struct vfio_device *device, |