On Thu, Aug 12, 2021 at 10:27:28AM -0300, Jason Gunthorpe wrote: > On Wed, Aug 11, 2021 at 02:07:37PM -0500, Bjorn Helgaas wrote: > > On Thu, Aug 05, 2021 at 09:23:57PM -0300, Jason Gunthorpe wrote: > > Do the other bus types have a flag analogous to > > PCI_ID_F_VFIO_DRIVER_OVERRIDE? If we're doing something similar to > > other bus types, it'd be nice if the approach were similar. > > They could, this series doesn't attempt it. I expect the approach to > be similar as driver_override was copied from PCI to other > busses. When this is completed I hope to take a look at it. I think this would make more sense as two patches: - Add a "PCI_ID_DRIVER_OVERRIDE" flag. This is not VFIO-specific, since nothing in PCI depends on the VFIO-ness of drivers that use the flag. The only point here is that driver id_table entries with this flag only match when driver_override matches the driver. - Update file2alias.c to export the flags and the "vfio_pci:" alias. This seems to be the only place where VFIO comes into play, and putting it in a separate patch will make it much smaller and it will be clear how it could be extended for other buses. > > I assume somewhere in here you need to unbind mlx5_core before binding > > mlx5_vfio_pci? > > Er, yes, I skipped some steps here where unbind/bind has to be done > > > > 6) cat the matched module name to driver_override: > > > echo mlx5_vfio_pci > /sys/bus/pci/devices/0000:01:00.0/driver_override > > > > Don't you need something here to trigger the driver attach, i.e., > > should step 5 and step 6 be swapped? What if the driver is already > > loaded? > > The full sequence is more like: > > echo mlx5_vfio_pci > /sys/bus/pci/devices/0000:01:00.0/driver_override > echo 0000:01:00.0 > /sys/bus/pci/devices/0000:01:00.0/driver/unbind > echo 0000:01:00.0 > /sys/bus/pci/drivers_probe Thanks a lot for this! I didn't know about drivers_probe (see drivers_probe_store()), and it doesn't seem to be documented anywhere except sysfs-bus-usb, where it's only incidental to USB. Bjorn