As discussed in this thread: https://lore.kernel.org/kvm/20220516172734.GE1343366@xxxxxxxxxx/ Let's remove VFIO_GROUP_NOTIFY_SET_KVM and instead assume the association has already been established prior to device_open. For the types today that need a KVM (GVT, vfio-ap) these will fail if a KVM is not found. Looking ahead, vfio-pci-zdev will optionally want the KVM association (enable hardware assists) but it will not be a hard requirement (still want to allow other, non-KVM userspace usage). This is built on top of Jason's group locking series: https://github.com/jgunthorpe/linux/commits/vfio_group_locking And tested with s390x-pci (zdev-kvm series) and vfio-ap (no GVT to test with) @Jason since it's based on your initial patch if you'd rather a SoB just let me know. Matthew Rosato (1): vfio: remove VFIO_GROUP_NOTIFY_SET_KVM drivers/gpu/drm/i915/gvt/gvt.h | 2 - drivers/gpu/drm/i915/gvt/kvmgt.c | 60 +++++------------------ drivers/s390/crypto/vfio_ap_ops.c | 35 +++----------- drivers/s390/crypto/vfio_ap_private.h | 3 -- drivers/vfio/vfio.c | 68 +++++++++------------------ include/linux/vfio.h | 5 +- 6 files changed, 41 insertions(+), 132 deletions(-) -- 2.27.0
