> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Wednesday, February 15, 2023 8:18 AM > > On Tue, Feb 14, 2023 at 04:42:35PM -0700, Alex Williamson wrote: > > > A device file opened through a group could be passed through this > > interface though, right? > > Yes, I think so > > > Do we just chalk that up to user error? Maybe the SPAPR extension > > at least needs to be documented as relying on registering groups > > rather than devices. > > The way these APIs work is you have to pass the same FD to all of > them. The SPAPR stuff is no different, if you used a cdev with > KVM_DEV_VFIO_GROUP_ADD then you have to use the same cdev fd with > the > SPAPR group_fd. Yi just didn't rename it. This is because SPAPR cannot accept cdev fd yet. It explicitly requires group fd and get iommu_group during the handling. Regards, Yi Liu