vfio/mdev: add mdev available instance checking to the core

Many of the mdev drivers use a simple counter for keeping track of the
available instances. Move this code to the core code and store the

vfio/mdev: add mdev available instance checking to the core

Many of the mdev drivers use a simple counter for keeping track of the
available instances. Move this code to the core code and store the counter
in the mdev_parent. Implement it using correct locking, fixing mdpy.

Drivers just provide the value in the mdev_driver at registration time
and the core code takes care of maintaining it and exposing the value in
sysfs.

[hch: count instances per-parent instead of per-type, use an atomic_t
to avoid taking mdev_list_lock in the show method]

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-15-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: consolidate all the description sysfs into the core code

Every driver just emits a string, simply add a method to the mdev_driver
to return it and provide a standard sysfs show function.

vfio/mdev: consolidate all the description sysfs into the core code

Every driver just emits a string, simply add a method to the mdev_driver
to return it and provide a standard sysfs show function.

Remove the now unused types_attrs field in struct mdev_driver and the
support code for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220923092652.100656-14-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: consolidate all the available_instance sysfs into the core code

Every driver just print a number, simply add a method to the mdev_driver
to return it and provide a standard sysfs show fun

vfio/mdev: consolidate all the available_instance sysfs into the core code

Every driver just print a number, simply add a method to the mdev_driver
to return it and provide a standard sysfs show function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-13-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: consolidate all the name sysfs into the core code

Every driver just emits a static string, simply add a field to the
mdev_type for the driver to fill out or fall back to the sysfs name an

vfio/mdev: consolidate all the name sysfs into the core code

Every driver just emits a static string, simply add a field to the
mdev_type for the driver to fill out or fall back to the sysfs name and
provide a standard sysfs show function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-12-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: consolidate all the device_api sysfs into the core code

Every driver just emits a static string, simply feed it through the ops
and provide a standard sysfs show function.

Signed-off-by:

vfio/mdev: consolidate all the device_api sysfs into the core code

Every driver just emits a static string, simply feed it through the ops
and provide a standard sysfs show function.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-11-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: remove mtype_get_parent_dev

Just open code the dereferences in the only user.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jas

vfio/mdev: remove mtype_get_parent_dev

Just open code the dereferences in the only user.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-10-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: remove mdev_parent_dev

Just open code the dereferences in the only user.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Ti

vfio/mdev: remove mdev_parent_dev

Just open code the dereferences in the only user.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220923092652.100656-9-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: unexport mdev_bus_type

mdev_bus_type is only used in mdev.ko now, so unexport it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by:

vfio/mdev: unexport mdev_bus_type

mdev_bus_type is only used in mdev.ko now, so unexport it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220923092652.100656-8-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: remove mdev_from_dev

Just open code it in the only caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian

vfio/mdev: remove mdev_from_dev

Just open code it in the only caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220923092652.100656-7-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: simplify mdev_type handling

Instead of abusing struct attribute_group to control initialization of
struct mdev_type, just define the actual attributes in the mdev_driver,
allocate the mde

vfio/mdev: simplify mdev_type handling

Instead of abusing struct attribute_group to control initialization of
struct mdev_type, just define the actual attributes in the mdev_driver,
allocate the mdev_type structures in the caller and pass them to
mdev_register_parent.

This allows the caller to use container_of to get at the containing
structure and thus significantly simplify the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-6-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: embedd struct mdev_parent in the parent data structure

Simplify mdev_{un}register_device by requiring the caller to pass in
a structure allocate as part of the parent device structure. T

vfio/mdev: embedd struct mdev_parent in the parent data structure

Simplify mdev_{un}register_device by requiring the caller to pass in
a structure allocate as part of the parent device structure. This
removes the need for a list of parents and the separate mdev_parent
refcount as we can simplify rely on the reference to the parent device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-5-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: make mdev.h standalone includable

Include <linux/device.h> and <linux/uuid.h> so that users of this headers
don't need to do that and remove those includes that aren't needed
any more.

S

vfio/mdev: make mdev.h standalone includable

Include <linux/device.h> and <linux/uuid.h> so that users of this headers
don't need to do that and remove those includes that aren't needed
any more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220923092652.100656-4-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/ccw: Remove UUID from s390 debug log

As vfio-ccw devices are created/destroyed, the uuid of the associated
mdevs that are recorded in $S390DBF/vfio_ccw_msg/sprintf get lost.
This is because a p

vfio/ccw: Remove UUID from s390 debug log

As vfio-ccw devices are created/destroyed, the uuid of the associated
mdevs that are recorded in $S390DBF/vfio_ccw_msg/sprintf get lost.
This is because a pointer to the UUID is stored instead of the UUID
itself, and that memory may have been repurposed if/when the logs are
examined. The result is usually garbage UUID data in the logs, though
there is an outside chance of an oops happening here.

Simply remove the UUID from the traces, as the subchannel number will
provide useful configuration information for problem determination,
and is stored directly into the log instead of a pointer.

As we were the only consumer of mdev_uuid(), remove that too.

Cc: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Michael Kawano <mkawano@linux.ibm.com>
Fixes: 60e05d1cf0875 ("vfio-ccw: add some logging")
Fixes: b7701dfbf9832 ("vfio-ccw: Register a chp_event callback for vfio-ccw")
[farman: reworded commit message, added Fixes: tags]
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220707135737.720765-2-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: Remove mdev drvdata

This is no longer used, remove it.

All usages were moved over to either use container_of() from a vfio_device
or to use dev_drvdata() directly on the mdev.

Signed-of

vfio/mdev: Remove mdev drvdata

This is no longer used, remove it.

All usages were moved over to either use container_of() from a vfio_device
or to use dev_drvdata() directly on the mdev.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-35-hch@lst.de
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>

show more ...

vfio/mdev: Remove mdev_parent_ops

The last useful member in this struct is the supported_type_groups, move
it to the mdev_driver and delete mdev_parent_ops.

Replace it with mdev_driver as an argume

vfio/mdev: Remove mdev_parent_ops

The last useful member in this struct is the supported_type_groups, move
it to the mdev_driver and delete mdev_parent_ops.

Replace it with mdev_driver as an argument to mdev_register_device()

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-33-hch@lst.de
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>

show more ...

vfio/mdev: Remove mdev_parent_ops dev_attr_groups

This is only used by one sample to print a fixed string that is pointless.

In general, having a device driver attach sysfs attributes to the parent

vfio/mdev: Remove mdev_parent_ops dev_attr_groups

This is only used by one sample to print a fixed string that is pointless.

In general, having a device driver attach sysfs attributes to the parent
is horrific. This should never happen, and always leads to some kind of
liftime bug as it become very difficult for the sysfs attribute to go back
to any data owned by the device driver.

Remove the general mechanism to create this abuse.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-32-hch@lst.de
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>

show more ...

vfio/mdev: Remove vfio_mdev.c

Now that all mdev drivers directly create their own mdev_device driver and
directly register with the vfio core's vfio_device_ops this is all dead
code.

Delete vfio_md

vfio/mdev: Remove vfio_mdev.c

Now that all mdev drivers directly create their own mdev_device driver and
directly register with the vfio core's vfio_device_ops this is all dead
code.

Delete vfio_mdev.c and the mdev_parent_ops members that are connected to
it.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-31-hch@lst.de
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>

show more ...

vfio: remove the unused mdev iommu hook

The iommu_device field in struct mdev_device has never been used
since it was added more than 2 years ago.

This is a manual revert of commit 7bd50f0cd2
("vfi

vfio: remove the unused mdev iommu hook

The iommu_device field in struct mdev_device has never been used
since it was added more than 2 years ago.

This is a manual revert of commit 7bd50f0cd2
("vfio/type1: Add domain at(de)taching group helpers").

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-11-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio: Remove struct vfio_device_ops open/release

Nothing uses this anymore, delete it.

Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ja

vfio: Remove struct vfio_device_ops open/release

Nothing uses this anymore, delete it.

Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/14-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio: Provide better generic support for open/release vfio_device_ops

Currently the driver ops have an open/release pair that is called once
each time a device FD is opened or closed. Add an additio

vfio: Provide better generic support for open/release vfio_device_ops

Currently the driver ops have an open/release pair that is called once
each time a device FD is opened or closed. Add an additional set of
open/close_device() ops which are called when the device FD is opened for
the first time and closed for the last time.

An analysis shows that all of the drivers require this semantic. Some are
open coding it as part of their reflck implementation, and some are just
buggy and miss it completely.

To retain the current semantics PCI and FSL depend on, introduce the idea
of a "device set" which is a grouping of vfio_device's that share the same
lock around opening.

The device set is established by providing a 'set_id' pointer. All
vfio_device's that provide the same pointer will be joined to the same
singleton memory and lock across the whole set. This effectively replaces
the oddly named reflck.

After conversion the set_id will be sourced from:
- A struct device from a fsl_mc_device (fsl)
- A struct pci_slot (pci)
- A struct pci_bus (pci)
- The struct vfio_device (everything)

The design ensures that the above pointers are live as long as the
vfio_device is registered, so they form reliable unique keys to group
vfio_devices into sets.

This implementation uses xarray instead of searching through the driver
core structures, which simplifies the somewhat tricky locking in this
area.

Following patches convert all the drivers.

Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: Allow the mdev_parent_ops to specify the device driver to bind

This allows a mdev driver to opt out of using vfio_mdev.c, instead the
driver will provide a 'struct mdev_driver' and regist

vfio/mdev: Allow the mdev_parent_ops to specify the device driver to bind

This allows a mdev driver to opt out of using vfio_mdev.c, instead the
driver will provide a 'struct mdev_driver' and register directly with the
driver core.

Much of mdev_parent_ops becomes unused in this mode:
- create()/remove() are done via the mdev_driver probe()/remove()
- mdev_attr_groups becomes mdev_driver driver.dev_groups
- Wrapper function callbacks are replaced with the same ones from
struct vfio_device_ops

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20210617142218.1877096-8-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: Correct the function signatures for the mdev_type_attributes

The driver core standard is to pass in the properly typed object, the
properly typed attribute and the buffer data. It stems f

vfio/mdev: Correct the function signatures for the mdev_type_attributes

The driver core standard is to pass in the properly typed object, the
properly typed attribute and the buffer data. It stems from the root
kobject method:

ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,..)

Each subclass of kobject should provide their own function with the same
signature but more specific types, eg struct device uses:

ssize_t (*show)(struct device *dev, struct device_attribute *attr,..)

In this case the existing signature is:

ssize_t (*show)(struct kobject *kobj, struct device *dev,..)

Where kobj is a 'struct mdev_type *' and dev is 'mdev_type->parent->dev'.

Change the mdev_type related sysfs attribute functions to:

ssize_t (*show)(struct mdev_type *mtype, struct mdev_type_attribute *attr,..)

In order to restore type safety and match the driver core standard

There are no current users of 'attr', but if it is ever needed it would be
hard to add in retroactively, so do it now.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <18-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: Remove kobj from mdev_parent_ops->create()

The kobj here is a type-erased version of mdev_type, which is already
stored in the struct mdev_device being passed in. It was only ever used to

vfio/mdev: Remove kobj from mdev_parent_ops->create()

The kobj here is a type-erased version of mdev_type, which is already
stored in the struct mdev_device being passed in. It was only ever used to
compute the type_group_id, which is now extracted directly from the mdev.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <17-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: Add mdev/mtype_get_type_group_id()

This returns the index in the supported_type_groups array that is
associated with the mdev_type attached to the struct mdev_device or its
containing str

vfio/mdev: Add mdev/mtype_get_type_group_id()

This returns the index in the supported_type_groups array that is
associated with the mdev_type attached to the struct mdev_device or its
containing struct kobject.

Each mdev_device can be spawned from exactly one mdev_type, which in turn
originates from exactly one supported_type_group.

Drivers are using weird string calculations to try and get back to this
index, providing a direct access to the index removes a bunch of wonky
driver code.

mdev_type->group can be deleted as the group is obtained using the
type_group_id.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <11-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...

vfio/mdev: Remove duplicate storage of parent in mdev_device

mdev_device->type->parent is the same thing.

The struct mdev_device was relying on the kref on the mdev_parent to also
indirectly hold a

vfio/mdev: Remove duplicate storage of parent in mdev_device

mdev_device->type->parent is the same thing.

The struct mdev_device was relying on the kref on the mdev_parent to also
indirectly hold a kref on the mdev_type pointer. Now that the type holds a
kref on the parent we can directly kref the mdev_type and remove this
implicit relationship.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <10-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...