[Intel-gfx] [PATCH v4 8/9] vfio/pci: Extend VFIO_DEVICE_GET_PCI_HOT_RESET_INFO for vfio device cdev

[Alex Williamson]

On Mon, 8 May 2023 15:32:44 +0000
"Liu, Yi L" <yi.l.liu at intel.com> wrote:

> > From: Alex Williamson <alex.williamson at redhat.com>
> > Sent: Friday, April 28, 2023 4:16 AM
> >  
> > > > + *
> > > >   * Return: 0 on success, -errno on failure:
> > > >   *	-enospc = insufficient buffer, -enodev = unsupported for device.
> > > >   */
> > > >  struct vfio_pci_dependent_device {
> > > > -	__u32	group_id;
> > > > +	union {
> > > > +		__u32   group_id;
> > > > +		__u32	dev_id;
> > > > +#define VFIO_PCI_DEVID_NONBLOCKING	0
> > > > +#define VFIO_PCI_DEVID_BLOCKING	-1  
> > >
> > > The above description seems like it's leaning towards OWNED rather than
> > > BLOCKING.  
> > 
> > Also these should be defined relative to something defined in IOMMUFD
> > rather than inventing values here.  We can't have the valid devid
> > number space owned by IOMMUFD conflict with these definitions.  Thanks,  
> 
> Jason has proposed to reserve all negative IDs and 0 in iommufd. In that case,
> can vfio define the numbers now?

Ok, as long as it's guaranteed that we're overlapping invalid dev-ids,
as specified by IOMMUFD, then the mapping of specific invalid dev-ids
to error values here is interface specific and can be defined here.
Thanks,

Alex