On Tue, 8 Nov 2022 20:48:08 -0400
Jason Gunthorpe <jgg@xxxxxxxx> wrote:
> On Sat, Nov 05, 2022 at 03:44:57PM -0700, Anthony DeRossi wrote:
> > The open count of a device set is the sum of the open counts of all
> > devices in the set. Drivers can use this value to determine whether
> > shared resources are in use without tracking them manually or accessing
> > the private open_count in vfio_device.
> >
> > Signed-off-by: Anthony DeRossi <ajderossi@xxxxxxxxx>
> > ---
> > drivers/vfio/vfio_main.c | 11 +++++++++++
> > include/linux/vfio.h | 1 +
> > 2 files changed, 12 insertions(+)
>
> >
> > +unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set)
> > +{
> > + struct vfio_device *cur;
> > + unsigned int open_count = 0;
>
> I'd probably just make this a bool
>
> 'vfio_device_set_last_close()'
>
> And roll in the < 1 logic too
>
> Nothing will ever need to know the number of fds open across the set.
'last_close' presumes the caller though, which seems bad form. It's
possible there are use cases for this in a 'first_open' scenario too.
Something along the lines of 'singleton_open', but that's a horrible
name, so we might as well just provide the count since we already have
it. Thanks,
Alex
> But this is fine as written
>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
>
> Jason
>
