@@ -86,6 +86,8 @@ struct vfio_group {
struct mutex unbound_lock;
atomic_t opened;
bool noiommu;
+ struct kvm *kvm;
+ struct blocking_notifier_head notifier;
};
struct vfio_device {
@@ -339,6 +341,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
#ifdef CONFIG_VFIO_NOIOMMU
group->noiommu = (iommu_group_get_iommudata(iommu_group) == &noiommu);
#endif
+ BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
group->nb.notifier_call = vfio_iommu_group_notifier;
@@ -1581,6 +1584,9 @@ static int vfio_group_fops_release(struct inode *inode, struct file *filep)
filep->private_data = NULL;
+ /* Any user didn't unregister? */
+ WARN_ON(group->notifier.head);
+
vfio_group_try_dissolve_container(group);
atomic_dec(&group->opened);
@@ -2063,6 +2069,76 @@ static int vfio_unregister_iommu_notifier(struct vfio_group *group,
return ret;
}
+void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
+{
+ group->kvm = kvm;
+ blocking_notifier_call_chain(&group->notifier,
+ VFIO_GROUP_NOTIFY_SET_KVM, kvm);
+}
+EXPORT_SYMBOL_GPL(vfio_group_set_kvm);
+
+static int vfio_register_group_notifier(struct vfio_group *group,
+ unsigned long *events,
+ struct notifier_block *nb)
+{
+ struct vfio_container *container;
+ int ret;
+ bool set_kvm = false;
+
+ if (*events & VFIO_GROUP_NOTIFY_SET_KVM)
+ set_kvm = true;
+
+ /* clear known events */
+ *events &= ~VFIO_GROUP_NOTIFY_SET_KVM;
+
+ /* refuse to continue if still events remaining */
+ if (*events)
+ return -EINVAL;
+
+ ret = vfio_group_add_container_user(group);
+ if (ret)
+ return -EINVAL;
+
+ container = group->container;
+ down_read(&container->group_lock);
+
+ ret = blocking_notifier_chain_register(&group->notifier, nb);
+
+ /*
+ * 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);
+
+ up_read(&container->group_lock);
+ vfio_group_try_dissolve_container(group);
+
+ return ret;
+}
+
+static int vfio_unregister_group_notifier(struct vfio_group *group,
+ struct notifier_block *nb)
+{
+ struct vfio_container *container;
+ int ret;
+
+ ret = vfio_group_add_container_user(group);
+ if (ret)
+ return -EINVAL;
+
+ container = group->container;
+ down_read(&container->group_lock);
+
+ ret = blocking_notifier_chain_unregister(&group->notifier, nb);
+
+ up_read(&container->group_lock);
+ vfio_group_try_dissolve_container(group);
+
+ return ret;
+}
+
int vfio_register_notifier(struct device *dev, vfio_notify_type_t type,
unsigned long *events,
struct notifier_block *nb)
@@ -2081,6 +2157,9 @@ int vfio_register_notifier(struct device *dev, vfio_notify_type_t type,
case VFIO_IOMMU_NOTIFY:
ret = vfio_register_iommu_notifier(group, events, nb);
break;
+ case VFIO_GROUP_NOTIFY:
+ ret = vfio_register_group_notifier(group, events, nb);
+ break;
default:
ret = -EINVAL;
}
@@ -2107,6 +2186,9 @@ int vfio_unregister_notifier(struct device *dev, vfio_notify_type_t type,
case VFIO_IOMMU_NOTIFY:
ret = vfio_unregister_iommu_notifier(group, nb);
break;
+ case VFIO_GROUP_NOTIFY:
+ ret = vfio_unregister_group_notifier(group, nb);
+ break;
default:
ret = -EINVAL;
}
@@ -120,11 +120,17 @@ extern int vfio_unregister_notifier(struct device *dev,
/* each type has independent events */
enum vfio_notify_type {
VFIO_IOMMU_NOTIFY = (__force vfio_notify_type_t)0,
+ VFIO_GROUP_NOTIFY = (__force vfio_notify_type_t)1,
};
/* events for VFIO_IOMMU_NOTIFY */
#define VFIO_IOMMU_NOTIFY_DMA_UNMAP BIT(0)
+/* events for VFIO_GROUP_NOTIFY */
+#define VFIO_GROUP_NOTIFY_SET_KVM BIT(0)
+
+struct kvm;
+extern void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
/*
* Sub-module helpers
Beyond vfio_iommu events, users might also be interested in vfio_group events. For example, if a vfio_group is used along with Qemu/KVM, whenever kvm pointer is set to/cleared from the vfio_group, users could be notified. Currently only VFIO_GROUP_NOTIFY_SET_KVM supported. Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Kirti Wankhede <kwankhede@nvidia.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Jike Song <jike.song@intel.com> --- drivers/vfio/vfio.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/vfio.h | 6 ++++ 2 files changed, 88 insertions(+)