vfio: iommu driver notify callback

Define a vfio_iommu_driver_ops notify callback, for sending events to
the driver.  Drivers are not required to provide the callback, and
may ignore any events.  The handling of events is driver specific.

Define the CONTAINER_CLOSE event, called when the container's file
descriptor is closed.  This event signifies that no further state changes
will occur via container ioctl's.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index f45940b38a02..b7e18bde5aa8 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -57,6 +57,11 @@ extern struct vfio_device *vfio_device_get_from_dev(struct device *dev);
 extern void vfio_device_put(struct vfio_device *device);
 extern void *vfio_device_data(struct vfio_device *device);
 
+/* events for the backend driver notify callback */
+enum vfio_iommu_notify_type {
+	VFIO_IOMMU_CONTAINER_CLOSE = 0,
+};
+
 /**
  * struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks
  */
@@ -92,6 +97,8 @@ struct vfio_iommu_driver_ops {
 				  void *data, size_t count, bool write);
 	struct iommu_domain *(*group_iommu_domain)(void *iommu_data,
 						   struct iommu_group *group);
+	void		(*notify)(void *iommu_data,
+				  enum vfio_iommu_notify_type event);
 };
 
 extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);