On Tue, Jun 12, 2018 at 8:00 PM Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > Yeah, the biusection seems to actually be diving into Greg's device pulls. > > Odd. I'm not seeing why that would break kvm, but maybe there's > something in the device core layer that really messed it up. > > I'll continue to bisect to see. Ok, so commit 95cde3c59966 ("debugfs: inode: debugfs_create_dir uses mode permission from parent") breaks lkvm, and I think qemu-kvm too. The commit looks like the RightThing(tm) to do, but we do not break existing work-flows, no matter how much we'd like to. So it gets reverted. Greg, Thomas, perhaps some alternative model? I'm not sure exactly what kvm needs from debugfs. Linus