[v4 0/3] plumb kvm/vfio to notify kvm:group attaching/detaching

[Jike Song <jike.song@intel.com>]

So far KVM and VFIO are mostly transparent to each other.
However, there are users who would rely on them both. For
example, KVMGT relies on VFIO to mediate device operations,
and it also relies on KVM for features such as guest page
tracking. To do that, it needs to know which KVM instance
a vfio_group is attached to, when it will be detached.

There is already a kvm_vfio device serving for similar
purpose, this series extends it to allow users register
notifiers on a vfio_group, and notify kvm:group attaching
and detaching events to that.


Based on Kirti:

	http://marc.info/?l=kvm&m=147913808504902


Changes v4:
	- use a notifier-based implementation in vfio_group
	- combine the notifier along with iommu notifier by Kirti
Changes v3:
	- don't touch kvm_put_kvm, vfio won't need it
	- fix a race condition
Changes v2:
	- As Paolo suggested, drop the type and get/put ops from
	  vfio, assuming that the data will always be kvm.

Jike Song (3):
  vfio: add vfio_group_notify support
  vfio_register_notifier: also register on the group notifier
  kvm: notify vfio on attaching and detaching

 drivers/vfio/vfio.c  | 34 ++++++++++++++++++++++++++++++++++
 include/linux/vfio.h |  4 ++++
 virt/kvm/vfio.c      | 31 +++++++++++++++++++++++++++++++
 3 files changed, 69 insertions(+)

-- 
1.9.1