vfio/ccw: Convert to use vfio_register_emulated_iommu_dev()

This is a more complicated conversion because vfio_ccw is sharing the
vfio_device between both the mdev_device, its vfio_device and the
css_driver.

The mdev is a singleton, and the reason for this sharing is so the extra
css_driver function callbacks to be delivered to the vfio_device
implementation.

This keeps things as they are, with the css_driver allocating the
singleton, not the mdev_driver.

Embed the vfio_device in the vfio_ccw_private and instantiate it as a
vfio_device when the mdev probes. The drvdata of both the css_device and
the mdev_device point at the private, and container_of is used to get it
back from the vfio_device.

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v4-cea4f5bd2c00+b52-ccw_mdev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 14 insertions, 7 deletions

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index e32678a71644..040742777095 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -468,7 +468,7 @@ static int __init vfio_ccw_sch_init(void)
 	vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw");
 	if (!vfio_ccw_work_q) {
 		ret = -ENOMEM;
-		goto out_err;
+		goto out_regions;
 	}
 
 	vfio_ccw_io_region = kmem_cache_create_usercopy("vfio_ccw_io_region",
@@ -477,7 +477,7 @@ static int __init vfio_ccw_sch_init(void)
 					sizeof(struct ccw_io_region), NULL);
 	if (!vfio_ccw_io_region) {
 		ret = -ENOMEM;
-		goto out_err;
+		goto out_regions;
 	}
 
 	vfio_ccw_cmd_region = kmem_cache_create_usercopy("vfio_ccw_cmd_region",
@@ -486,7 +486,7 @@ static int __init vfio_ccw_sch_init(void)
 					sizeof(struct ccw_cmd_region), NULL);
 	if (!vfio_ccw_cmd_region) {
 		ret = -ENOMEM;
-		goto out_err;
+		goto out_regions;
 	}
 
 	vfio_ccw_schib_region = kmem_cache_create_usercopy("vfio_ccw_schib_region",
@@ -496,7 +496,7 @@ static int __init vfio_ccw_sch_init(void)
 
 	if (!vfio_ccw_schib_region) {
 		ret = -ENOMEM;
-		goto out_err;
+		goto out_regions;
 	}
 
 	vfio_ccw_crw_region = kmem_cache_create_usercopy("vfio_ccw_crw_region",
@@ -506,19 +506,25 @@ static int __init vfio_ccw_sch_init(void)
 
 	if (!vfio_ccw_crw_region) {
 		ret = -ENOMEM;
-		goto out_err;
+		goto out_regions;
 	}
 
+	ret = mdev_register_driver(&vfio_ccw_mdev_driver);
+	if (ret)
+		goto out_regions;
+
 	isc_register(VFIO_CCW_ISC);
 	ret = css_driver_register(&vfio_ccw_sch_driver);
 	if (ret) {
 		isc_unregister(VFIO_CCW_ISC);
-		goto out_err;
+		goto out_driver;
 	}
 
 	return ret;
 
-out_err:
+out_driver:
+	mdev_unregister_driver(&vfio_ccw_mdev_driver);
+out_regions:
 	vfio_ccw_destroy_regions();
 	destroy_workqueue(vfio_ccw_work_q);
 	vfio_ccw_debug_exit();
@@ -528,6 +534,7 @@ out_err:
 static void __exit vfio_ccw_sch_exit(void)
 {
 	css_driver_unregister(&vfio_ccw_sch_driver);
+	mdev_unregister_driver(&vfio_ccw_mdev_driver);
 	isc_unregister(VFIO_CCW_ISC);
 	vfio_ccw_destroy_regions();
 	destroy_workqueue(vfio_ccw_work_q);