On Wed, Apr 13, 2022 at 06:06:01PM +0200, Christoph Hellwig wrote: > On Wed, Apr 13, 2022 at 08:39:52AM -0300, Jason Gunthorpe wrote: > > I already looked into that for a while, it is a real mess too because > > of how the notifiers are used by the current drivers, eg gvt assumes > > the notifier is called during its open_device callback to setup its > > kvm. > > gvt very much expects kvm to be set before open and thus get the > cachup notifier, yes. And given that this is how qemu uses > the ioctl I think we can actually simplify this further and require > vfio_group_set_kvm to be called before open for s390/ap as well and > do away with this whole mess. Yeah, I was thinking about that too, but on the other hand I think it is completely wrong that gvt requires kvm at all. A vfio_device is not supposed to be tightly linked to KVM - the only exception possibly being s390.. Jason