Commit 38c24544 authored by Yi Liu's avatar Yi Liu Committed by Alex Williamson
Browse files

vfio: Move device_del() before waiting for the last vfio_device registration refcount 



device_del() destroys the vfio-dev/vfioX under the sysfs for vfio_device.
There is no reason to keep it while the device is going to be unregistered.

This movement is also a preparation for adding vfio_device cdev. Kernel
should remove the cdev node of the vfio_device to avoid new registration
refcount increment while the device is going to be unregistered.

Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Tested-by: default avatarZhenzhong Duan <zhenzhong.duan@intel.com>
Tested-by: default avatarYanting Jiang <yanting.jiang@intel.com>
Signed-off-by: default avatarYi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-18-yi.l.liu@intel.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 291872a5

drivers/vfio/vfio_main.c

+3 −3
Original line number Diff line number Diff line
@@ -338,6 +338,9 @@ void vfio_unregister_group_dev(struct vfio_device *device) 
	 */

	vfio_device_group_unregister(device);



	/* Balances device_add in register path */

	device_del(&device->device);



	vfio_device_put_registration(device);

	rc = try_wait_for_completion(&device->comp);

	while (rc <= 0) {
@@ -361,9 +364,6 @@ void vfio_unregister_group_dev(struct vfio_device *device) 
		}

	}



	/* Balances device_add in register path */

	device_del(&device->device);



	/* Balances vfio_device_set_group in register path */

	vfio_device_remove_group(device);

}