linux-stable.git/drivers/vfio/mdev/mdev_core.c, branch linux-5.17.y

vfio/mdev: don't warn if ->request is not set

2021-08-02T21:23:43+00:00

Only a single driver actually sets the ->request method, so don't print
a scary warning if it isn't.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Cornelia Huck 
Reviewed-by: Jason Gunthorpe 
Link: https://lore.kernel.org/r/20210726143524.155779-3-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: turn mdev_init into a subsys_initcall

2021-08-02T21:23:43+00:00

Without this setups with buіlt-in mdev and mdev-drivers fail to
register like this:

[1.903149] Driver 'intel_vgpu_mdev' was unable to register with bus_type 'mdev' because the bus was not initialized.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Cornelia Huck 
Reviewed-by: Jason Gunthorpe 
Link: https://lore.kernel.org/r/20210726143524.155779-2-hch@lst.de
Signed-off-by: Alex Williamson

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

2021-06-21T21:29:25+00:00

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 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Cornelia Huck 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Kirti Wankhede 
Link: https://lore.kernel.org/r/20210617142218.1877096-8-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: Remove CONFIG_VFIO_MDEV_DEVICE

2021-06-21T21:29:25+00:00

For some reason the vfio_mdev shim mdev_driver has its own module and
kconfig. As the next patch requires access to it from mdev.ko merge the
two modules together and remove VFIO_MDEV_DEVICE.

A later patch deletes this driver entirely.

Signed-off-by: Jason Gunthorpe 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Cornelia Huck 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Kirti Wankhede 
Link: https://lore.kernel.org/r/20210617142218.1877096-7-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: Correct the function signatures for the mdev_type_attributes

2021-04-12T16:36:00+00:00

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 
Reviewed-by: Cornelia Huck 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jason Gunthorpe 
Message-Id: <18-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson

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

2021-04-12T16:36:00+00:00

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 
Reviewed-by: Cornelia Huck 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jason Gunthorpe 
Message-Id: <17-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson

vfio/mdev: Add mdev/mtype_get_type_group_id()

2021-04-07T21:39:18+00:00

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 
Reviewed-by: Kevin Tian 
Reviewed-by: Cornelia Huck 
Signed-off-by: Jason Gunthorpe 
Message-Id: <11-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson

vfio/mdev: Remove duplicate storage of parent in mdev_device

2021-04-07T21:39:18+00:00

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 
Reviewed-by: Cornelia Huck 
Signed-off-by: Jason Gunthorpe 
Message-Id: <10-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson

vfio/mdev: Add missing error handling to dev_set_name()

2021-04-07T21:39:18+00:00

This can fail, and seems to be a popular target for syzkaller error
injection. Check the error return and unwind with put_device().

Fixes: 7b96953bc640 ("vfio: Mediated device Core driver")
Reviewed-by: Christoph Hellwig 
Reviewed-by: Kevin Tian 
Reviewed-by: Max Gurtovoy 
Reviewed-by: Cornelia Huck 
Signed-off-by: Jason Gunthorpe 
Message-Id: <9-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson

vfio/mdev: Reorganize mdev_device_create()

2021-04-07T21:39:18+00:00

Once the memory for the struct mdev_device is allocated it should
immediately be device_initialize()'d and filled in so that put_device()
can always be used to undo the allocation.

Place the mdev_get/put_parent() so that they are clearly protecting the
mdev->parent pointer. Move the final put to the release function so that
the lifetime rules are trivial to understand. Update the goto labels to
follow the normal convention.

Remove mdev_device_free() as the release function via device_put() is now
usable in all cases.

Reviewed-by: Christoph Hellwig 
Reviewed-by: Kevin Tian 
Reviewed-by: Cornelia Huck 
Signed-off-by: Jason Gunthorpe 
Message-Id: <8-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson