[PATCH 0/1] vfio: remove VFIO_GROUP_NOTIFY_SET_KVM

[Matthew Rosato <mjrosato@linux.ibm.com>]

As discussed in this thread:

https://lore.kernel.org/kvm/20220516172734.GE1343366@nvidia.com/

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