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Subject: RE: [PATCH v3 15/15] vfio: Add struct device to vfio_device
Thread-Topic: [PATCH v3 15/15] vfio: Add struct device to vfio_device
Thread-Index: AQHYw/kWx/ZcHkFOHU+t8x4U9WUM+a3o1qGAgAAo6+A=
Date:   Tue, 20 Sep 2022 22:55:40 +0000
Message-ID: <BN9PR11MB5276484952784F5E336814BD8C4C9@BN9PR11MB5276.namprd11.prod.outlook.com>
References: <20220909102247.67324-1-kevin.tian@intel.com>
        <20220909102247.67324-16-kevin.tian@intel.com>
 <20220920142639.29b1bdc2.alex.williamson@redhat.com>
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> From: Alex Williamson <alex.williamson@redhat.com>
> Sent: Wednesday, September 21, 2022 4:27 AM
>=20
> On Fri,  9 Sep 2022 18:22:47 +0800
> Kevin Tian <kevin.tian@intel.com> wrote:
>=20
> > From: Yi Liu <yi.l.liu@intel.com>
> >
> > 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.
> >
> > Add Documentation/ABI/testing/sysfs-devices-vfio-dev.
> >
> > Also take this chance to rename chardev 'vfio' to 'vfio-group' in
> > /proc/devices.
>=20
> What's the risk/reward here, is this just more aesthetically pleasing
> symmetry vs 'vfio-dev'?  The char major number to name association in
> /proc/devices seems pretty obscure, but what due diligence have we done
> to make sure this doesn't break anyone?  Thanks,
>=20

I'm not sure whether the content of /proc/devices is considered as ABI.

@Jason?

But to be safe I can remove this change in next version. If it's the right
thing to do such change after discussion then it can be done in a separate
patch after.