Alex, As promised, here is a v3 with a message indicating a request is blocked until a user releases the device in question and a corresponding tweak to the commit message describing this change (and Conny's r-b). The remainder of the patches are otherwise identical. v2 : https://lore.kernel.org/kvm/20201120180740.87837-1-farman@xxxxxxxxxxxxx/ v1(RFC) : https://lore.kernel.org/kvm/20201117032139.50988-1-farman@xxxxxxxxxxxxx/ Eric Farman (2): vfio-mdev: Wire in a request handler for mdev parent vfio-ccw: Wire in the request callback drivers/s390/cio/vfio_ccw_ops.c | 26 ++++++++++++++++++++++++++ drivers/s390/cio/vfio_ccw_private.h | 4 ++++ drivers/vfio/mdev/mdev_core.c | 4 ++++ drivers/vfio/mdev/vfio_mdev.c | 13 +++++++++++++ include/linux/mdev.h | 4 ++++ include/uapi/linux/vfio.h | 1 + 6 files changed, 52 insertions(+) -- 2.17.1