On Thu, Aug 04, 2022 at 01:51:20PM -0300, Jason Gunthorpe wrote: > On Mon, Aug 01, 2022 at 09:49:28AM -0600, Alex Williamson wrote: > > > > > > > Fortunately these new vendor/device-specific drivers can be easily > > > > > > identified as being "vfio-pci + extra stuff" - all that's needed is to > > > > > > look at the output of the "modinfo $driver_name" command to see if > > > > > > "vfio_pci" is in the alias list for the driver. > > We are moving in a direction on the kernel side to expose a sysfs > under the PCI device that definitively says it is VFIO enabled, eg > something like > > /sys/devices/pci0000:00/0000:00:1f.6/vfio/<N> > > Which is how every other subsystem in the kernel works. When this > lands libvirt can simply stat the vfio directory and confirm that the > device handle it is looking at is vfio enabled, for all things that > vfio support. > > My thinking had been to do the above work a bit later, but if libvirt > needs it right now then lets do it right away so we don't have to > worry about this hacky modprobe stuff down the road? I wouldn't go so far as to say libvirt "needs" it, as obviously we can make it work using module.alias information. I would say that exposing this in sysfs though makes it simpler and faster, because the check then essentially turns into a single stat() call. So from that POV libvirt would be happy to see that improvement. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
