RE: [PATCH 15/15] vfio: Add struct device to vfio_device

[Tian, Kevin]

> From: Jason Gunthorpe <jgg@xxxxxxxx>
> Sent: Wednesday, August 31, 2022 8:32 AM
> 
> On Sun, Aug 28, 2022 at 01:10:37AM +0800, Kevin Tian wrote:
> > From: Yi Liu <yi.l.liu@xxxxxxxxx>
> >
> > and replace kref. With it a 'vfio-dev/vfioX' node is created under the
> > sysfs path of the parent, indicating the device is bound to a vfio
> > driver, e.g.:
> >
> > /sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0
> >
> > It is also a preparatory step toward adding cdev for supporting future
> > device-oriented uAPI.
> >
> > Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> > Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
> > Signed-off-by: Kevin Tian <kevin.tian@xxxxxxxxx>
> > ---
> >  drivers/vfio/vfio_main.c | 70 +++++++++++++++++++++++++++++++++-------
> >  include/linux/vfio.h     |  6 ++--
> >  2 files changed, 61 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> > index 0c5d120aeced..9ad0cbb83f1c 100644
> > --- a/drivers/vfio/vfio_main.c
> > +++ b/drivers/vfio/vfio_main.c
> > @@ -46,6 +46,8 @@ static struct vfio {
> >  	struct mutex			group_lock; /* locks group_list */
> >  	struct ida			group_ida;
> >  	dev_t				group_devt;
> > +	struct class			*device_class;
> > +	struct ida			device_ida;
> >  } vfio;
> >
> >  struct vfio_iommu_driver {
> > @@ -524,11 +526,19 @@ EXPORT_SYMBOL_GPL(_vfio_alloc_device);
> >   *
> >   * Only vfio-ccw driver should call this interface.
> >   */
> > +static void vfio_device_release(struct device *dev);
> 
> Since you added this new function in patch 1, it would be nice to
> place it in a way that avoids this forward reference in this patch
> 
> >  	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1,
> "vfio");
> 
> I think we should change this "vfio" string at this point, it is
> really the group fd, so "vfio_group" ?
> 
> It only shows in procfs.
> 

All make sense and fixed.