[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <BN9PR11MB527652CF1116B185E4311FDF8C4E9@BN9PR11MB5276.namprd11.prod.outlook.com>
Date: Thu, 22 Sep 2022 05:18:34 +0000
From: "Tian, Kevin" <kevin.tian@...el.com>
To: Jason Gunthorpe <jgg@...pe.ca>
CC: Alex Williamson <alex.williamson@...hat.com>,
Zhenyu Wang <zhenyuw@...ux.intel.com>,
"Wang, Zhi A" <zhi.a.wang@...el.com>,
Jani Nikula <jani.nikula@...ux.intel.com>,
Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
"Vivi, Rodrigo" <rodrigo.vivi@...el.com>,
Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>,
David Airlie <airlied@...ux.ie>,
Daniel Vetter <daniel@...ll.ch>,
Eric Farman <farman@...ux.ibm.com>,
Matthew Rosato <mjrosato@...ux.ibm.com>,
Halil Pasic <pasic@...ux.ibm.com>,
Vineeth Vijayan <vneethv@...ux.ibm.com>,
"Peter Oberparleiter" <oberpar@...ux.ibm.com>,
Heiko Carstens <hca@...ux.ibm.com>,
Vasily Gorbik <gor@...ux.ibm.com>,
Alexander Gordeev <agordeev@...ux.ibm.com>,
Christian Borntraeger <borntraeger@...ux.ibm.com>,
Sven Schnelle <svens@...ux.ibm.com>,
Tony Krowiak <akrowiak@...ux.ibm.com>,
Jason Herne <jjherne@...ux.ibm.com>,
Harald Freudenberger <freude@...ux.ibm.com>,
Diana Craciun <diana.craciun@....nxp.com>,
"Cornelia Huck" <cohuck@...hat.com>,
Longfang Liu <liulongfang@...wei.com>,
"Shameer Kolothum" <shameerali.kolothum.thodi@...wei.com>,
Yishai Hadas <yishaih@...dia.com>,
Eric Auger <eric.auger@...hat.com>,
Kirti Wankhede <kwankhede@...dia.com>,
Leon Romanovsky <leon@...nel.org>,
Abhishek Sahu <abhsahu@...dia.com>,
Christoph Hellwig <hch@...radead.org>,
"intel-gvt-dev@...ts.freedesktop.org"
<intel-gvt-dev@...ts.freedesktop.org>,
"intel-gfx@...ts.freedesktop.org" <intel-gfx@...ts.freedesktop.org>,
"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-s390@...r.kernel.org" <linux-s390@...r.kernel.org>,
"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
"Liu, Yi L" <yi.l.liu@...el.com>
Subject: RE: [PATCH v3 15/15] vfio: Add struct device to vfio_device
> From: Jason Gunthorpe <jgg@...pe.ca>
> 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@...hat.com>
> > > Sent: Wednesday, September 21, 2022 4:27 AM
> > >
> > > On Fri, 9 Sep 2022 18:22:47 +0800
> > > Kevin Tian <kevin.tian@...el.com> wrote:
> > >
> > > > From: Yi Liu <yi.l.liu@...el.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.
> > >
> > > 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.
Powered by blists - more mailing lists