> From: Jason Gunthorpe <jgg@xxxxxxxx> > Sent: Thursday, September 22, 2022 12:10 AM > > On Tue, Sep 20, 2022 at 10:55:40PM +0000, Tian, Kevin wrote: > > > From: Alex Williamson <alex.williamson@xxxxxxxxxx> > > > Sent: Wednesday, September 21, 2022 4:27 AM > > > > > > On Fri, 9 Sep 2022 18:22:47 +0800 > > > Kevin Tian <kevin.tian@xxxxxxxxx> 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. > > > > > > > > Add Documentation/ABI/testing/sysfs-devices-vfio-dev. > > > > > > > > Also take this chance to rename chardev 'vfio' to 'vfio-group' in > > > > /proc/devices. > > > > > > 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, > > > > I'm not sure whether the content of /proc/devices is considered as ABI. > > > > @Jason? > > Ah, I've forgotten why we got here - didn't we have a naming conflict > with the new stuff that is being introduced? No, we don't have. There is no new char dev introduced in this series. Later when device cdev is added a new device major will be allocated for 'vfio-dev'. It's at that time renaming existing 'vfio' to 'vfio-group' is probably clearer, which is what I understood from your earlier suggestion. > > ABI wise it is not a problem unless there is a real user, I'm not > aware of anything scanning /proc, that has been obsoleted by sysfs a > long time ago. > This is a good news.
