linux-stable.git/drivers/vfio/mdev/mdev_core.c, branch v6.3

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

2022-10-04T18:06:58+00:00

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 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Kevin Tian 
Reviewed-by: Kirti Wankhede 
Reviewed-by: Eric Farman 
Link: https://lore.kernel.org/r/20220923092652.100656-15-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: remove mtype_get_parent_dev

2022-10-04T18:06:58+00:00

Just open code the dereferences in the only user.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Jason J. Herne 
Reviewed-by: Kevin Tian 
Reviewed-by: Kirti Wankhede 
Reviewed-by: Eric Farman 
Link: https://lore.kernel.org/r/20220923092652.100656-10-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: remove mdev_parent_dev

2022-10-04T18:06:58+00:00

Just open code the dereferences in the only user.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Kevin Tian 
Reviewed-by: Kirti Wankhede 
Link: https://lore.kernel.org/r/20220923092652.100656-9-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: remove mdev_from_dev

2022-10-04T18:06:58+00:00

Just open code it in the only caller.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Kevin Tian 
Reviewed-by: Kirti Wankhede 
Link: https://lore.kernel.org/r/20220923092652.100656-7-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: simplify mdev_type handling

2022-10-04T18:06:58+00:00

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 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Tony Krowiak 
Reviewed-by: Kevin Tian 
Reviewed-by: Kirti Wankhede 
Reviewed-by: Eric Farman 
Link: https://lore.kernel.org/r/20220923092652.100656-6-hch@lst.de
Signed-off-by: Alex Williamson

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

2022-10-04T18:06:58+00:00

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 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Tony Krowiak 
Reviewed-by: Kevin Tian 
Reviewed-by: Kirti Wankhede 
Reviewed-by: Eric Farman 
Link: https://lore.kernel.org/r/20220923092652.100656-5-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: make mdev.h standalone includable

2022-10-04T18:06:58+00:00

Include  and  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 
Reviewed-by: Eric Farman 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Tony Krowiak 
Reviewed-by: Kevin Tian 
Reviewed-by: Kirti Wankhede 
Link: https://lore.kernel.org/r/20220923092652.100656-4-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: Use the driver core to create the 'remove' file

2022-04-21T11:36:56+00:00

The device creator is supposed to use the dev.groups value to add sysfs
files before device_add is called, not call sysfs_create_files() after
device_add() returns. This creates a race with uevent delivery where the
extra attribute will not be visible.

This was being done because the groups had been co-opted by the mdev
driver, now that prior patches have moved the driver's groups to the
struct device_driver the dev.group is properly free for use here.

Signed-off-by: Jason Gunthorpe 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Zhi Wang 
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-34-hch@lst.de
Reviewed-by: Kirti Wankhede 
Reviewed-by: Zhi Wang

vfio/mdev: Remove mdev_parent_ops

2022-04-21T11:36:56+00:00

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 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Zhi Wang 
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-33-hch@lst.de
Reviewed-by: Kirti Wankhede 
Reviewed-by: Zhi Wang

vfio/mdev: Remove vfio_mdev.c

2022-04-21T11:36:56+00:00

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 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Zhi Wang 
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-31-hch@lst.de
Reviewed-by: Kirti Wankhede 
Reviewed-by: Zhi Wang