Re: [PATCH v4 8/9] vfio/pci: Extend VFIO_DEVICE_GET_PCI_HOT_RESET_INFO for vfio device cdev

Alex Williamson
2023-05-08T20:30:49Z

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

> > From: Alex Williamson <alex.williamson@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