Merge tag 'vfio-v5.14-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Module reference fixes, structure renaming (Max Gurtovoy)

 - Export and use common pci_dev_trylock() (Luis Chamberlain)

 - Enable direct mdev device creation and probing by parent (Christoph
   Hellwig & Jason Gunthorpe)

 - Fix mdpy error path leak (Colin Ian King)

 - Fix mtty list entry leak (Jason Gunthorpe)

 - Enforce mtty device limit (Alex Williamson)

 - Resolve concurrent vfio-pci mmap faults (Alex Williamson)

* tag 'vfio-v5.14-rc1' of git://github.com/awilliam/linux-vfio:
  vfio/pci: Handle concurrent vma faults
  vfio/mtty: Enforce available_instances
  vfio/mtty: Delete mdev_devices_list
  vfio: use the new pci_dev_trylock() helper to simplify try lock
  PCI: Export pci_dev_trylock() and pci_dev_unlock()
  vfio/mdpy: Fix memory leak of object mdev_state->vconfig
  vfio/iommu_type1: rename vfio_group struck to vfio_iommu_group
  vfio/mbochs: Convert to use vfio_register_group_dev()
  vfio/mdpy: Convert to use vfio_register_group_dev()
  vfio/mtty: Convert to use vfio_register_group_dev()
  vfio/mdev: Allow the mdev_parent_ops to specify the device driver to bind
  vfio/mdev: Remove CONFIG_VFIO_MDEV_DEVICE
  driver core: Export device_driver_attach()
  driver core: Don't return EPROBE_DEFER to userspace during sysfs bind
  driver core: Flow the return code from ->probe() through to sysfs bind
  driver core: Better distinguish probe errors in really_probe
  driver core: Pull required checks into driver_probe_device()
  vfio/platform: remove unneeded parent_module attribute
  vfio: centralize module refcount in subsystem layer

Documentation/driver-api/vfio-mediated-device.rst

@@ -93,7 +93,7 @@ interfaces:
 Registration Interface for a Mediated Bus Driver
 ------------------------------------------------
 
-The registration interface for a mediated bus driver provides the following
+The registration interface for a mediated device driver provides the following
 structure to represent a mediated device's driver::
 
      /*
@@ -136,37 +136,26 @@ The structures in the mdev_parent_ops structure are as follows:
 * dev_attr_groups: attributes of the parent device
 * mdev_attr_groups: attributes of the mediated device
 * supported_config: attributes to define supported configurations
+* device_driver: device driver to bind for mediated device instances
 
-The functions in the mdev_parent_ops structure are as follows:
+The mdev_parent_ops also still has various functions pointers.  Theses exist
+for historical reasons only and shall not be used for new drivers.
 
-* create: allocate basic resources in a driver for a mediated device
-* remove: free resources in a driver when a mediated device is destroyed
-
-(Note that mdev-core provides no implicit serialization of create/remove
-callbacks per mdev parent device, per mdev type, or any other categorization.
-Vendor drivers are expected to be fully asynchronous in this respect or
-provide their own internal resource protection.)
-
-The callbacks in the mdev_parent_ops structure are as follows:
-
-* open: open callback of mediated device
-* close: close callback of mediated device
-* ioctl: ioctl callback of mediated device
-* read : read emulation callback
-* write: write emulation callback
-* mmap: mmap emulation callback
-
-A driver should use the mdev_parent_ops structure in the function call to
-register itself with the mdev core driver::
+When a driver wants to add the GUID creation sysfs to an existing device it has
+probe'd to then it should call::
 
 	extern int  mdev_register_device(struct device *dev,
 	                                 const struct mdev_parent_ops *ops);
 
-However, the mdev_parent_ops structure is not required in the function call
-that a driver should use to unregister itself with the mdev core driver::
+This will provide the 'mdev_supported_types/XX/create' files which can then be
+used to trigger the creation of a mdev_device. The created mdev_device will be
+attached to the specified driver.
+
+When the driver needs to remove itself it calls::
 
 	extern void mdev_unregister_device(struct device *dev);
 
+Which will unbind and destroy all the created mdevs and remove the sysfs files.
 
 Mediated Device Management Interface Through sysfs
 ==================================================

Documentation/s390/vfio-ap.rst

@@ -514,7 +514,6 @@ These are the steps:
    * S390_AP_IOMMU
    * VFIO
    * VFIO_MDEV
-   * VFIO_MDEV_DEVICE
    * KVM
 
    If using make menuconfig select the following to build the vfio_ap module::

arch/s390/Kconfig

@@ -767,7 +767,7 @@ config VFIO_CCW
 config VFIO_AP
 	def_tristate n
 	prompt "VFIO support for AP devices"
-	depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM
+	depends on S390_AP_IOMMU && VFIO_MDEV && KVM
 	depends on ZCRYPT
 	help
 		This driver grants access to Adjunct Processor (AP) devices

drivers/base/base.h

@@ -152,7 +152,6 @@ extern int driver_add_groups(struct device_driver *drv,
 			     const struct attribute_group **groups);
 extern void driver_remove_groups(struct device_driver *drv,
 				 const struct attribute_group **groups);
-int device_driver_attach(struct device_driver *drv, struct device *dev);
 void device_driver_detach(struct device *dev);
 
 extern char *make_class_name(const char *name, struct kobject *kobj);

drivers/base/bus.c

@@ -210,15 +210,11 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf,
 	int err = -ENODEV;
 
 	dev = bus_find_device_by_name(bus, NULL, buf);
-	if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
+	if (dev && driver_match_device(drv, dev)) {
 		err = device_driver_attach(drv, dev);
-
-		if (err > 0) {
+		if (!err) {
 			/* success */
 			err = count;
-		} else if (err == 0) {
-			/* driver didn't accept device */
-			err = -ENODEV;
 		}
 	}
 	put_device(dev);