On 3/13/2021 2:55 AM, Jason Gunthorpe wrote:
This makes the struct vfio_pci_device part of the public interface so it
can be used with container_of and so forth, as is typical for a Linux
subystem.
This is the first step to bring some type-safety to the vfio interface by
allowing the replacement of 'void *' and 'struct device *' inputs with a
simple and clear 'struct vfio_pci_device *'
For now the self-allocating vfio_add_group_dev() interface is kept so each
user can be updated as a separate patch.
The expected usage pattern is
driver core probe() function:
my_device = kzalloc(sizeof(*mydevice));
vfio_init_group_dev(&my_device->vdev, dev, ops, mydevice);
/* other driver specific prep */
vfio_register_group_dev(&my_device->vdev);
dev_set_drvdata(my_device);
driver core remove() function:
my_device = dev_get_drvdata(dev);
vfio_unregister_group_dev(&my_device->vdev);
/* other driver specific tear down */
kfree(my_device);
Allowing the driver to be able to use the drvdata and vifo_device to go
to/from its own data.
The pattern also makes it clear that vfio_register_group_dev() must be
last in the sequence, as once it is called the core code can immediately
start calling ops. The init/register gap is provided to allow for the
driver to do setup before ops can be called and thus avoid races.
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
Documentation/driver-api/vfio.rst | 31 ++++----
drivers/vfio/vfio.c | 123 ++++++++++++++++--------------
include/linux/vfio.h | 16 ++++
3 files changed, 98 insertions(+), 72 deletions(-)
With comments from Cornelia and Kevin, looks good.
Reviewed-by: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
