Merge tag 'drm-intel-fixes-2017-10-26' of...

Merge tag 'drm-intel-fixes-2017-10-26' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

One fix for stable:

- fix perf enable/disable ioctls for 32bits (Lionel)

Plus GVT fixes:

- Fix per_ctx_bb check (Zhenyu)
- Fix GPU hang of Linux guest (Xion)
- Refine MMIO_RING_F to check for presence of VCS2 ring (Zhi)

* tag 'drm-intel-fixes-2017-10-26' of git://anongit.freedesktop.org/drm/drm-intel:
  drm/i915/gvt: Adding ACTHD mmio read handler
  drm/i915/gvt: Extract mmio_read_from_hw() common function
  drm/i915/gvt: Refine MMIO_RING_F()
  drm/i915/gvt: properly check per_ctx bb valid state