drm/i915/gvt: Limit read hw reg to active vgpu
authorXiong Zhang <xiong.y.zhang@intel.com>
Mon, 6 Nov 2017 21:23:02 +0000 (05:23 +0800)
committerZhenyu Wang <zhenyuw@linux.intel.com>
Thu, 16 Nov 2017 03:48:35 +0000 (11:48 +0800)
commit295764cd2ff41e2c1bc8af4050de77cec5e7a1c0
tree59a1efa786e0e2001ed0ce421dc24d821ad3b970
parent5c35258de6cfc0829803fe9f9869253a4e600925
drm/i915/gvt: Limit read hw reg to active vgpu

mmio_read_from_hw() let vgpu could read hw reg, if vgpu's workload
is running on hw, things is good. Otherwise vgpu will get other
vgpu's reg val, it is unsafe.

This patch limit such hw access to active vgpu. If vgpu isn't
running on hw, the reg read of this vgpu will get the last active
val which saved at schedule_out.

v2: ring timestamp is walking continuously even if the ring is idle.
    so read hw directly. (Zhenyu)

Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
drivers/gpu/drm/i915/gvt/handlers.c
drivers/gpu/drm/i915/gvt/scheduler.c