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authorLinus Torvalds <torvalds@linux-foundation.org>2021-07-03 11:49:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-03 11:49:33 -0700
commit8e8d9442d1139d05d0c3b83efa34c4b7693d2969 (patch)
tree33af777d1e177b0f950a406ae7c8a2dac2147dbc /Documentation/driver-api
parent58ec9059b396a570b208239b4edc45eeb68b14c4 (diff)
parent6a45ece4c9af473555f01f0f8b97eba56e3c7d0d (diff)
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
Diffstat (limited to 'Documentation/driver-api')
-rw-r--r--Documentation/driver-api/vfio-mediated-device.rst35
1 files changed, 12 insertions, 23 deletions
diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 1779b85f014e..9f26079cacae 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/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
==================================================