drm/i915/gvt: Introduce basic vGPU life cycle management

A vGPU represents a virtual Intel GEN hardware, which consists following
virtual resources:

- Configuration space (virtualized)
- HW registers (virtualized)
- GGTT memory space (partitioned)
- GPU page table (shadowed)
- Fence registers (partitioned)

* virtualized: fully emulated by GVT-g.
* partitioned: Only a part of the HW resource is allowed to be accessed
by VM.
* shadowed: Resource needs to be translated and shadowed before getting
applied into HW.

This patch introduces vGPU life cycle management framework, which is
responsible for creating/destroying a vGPU and preparing/free resources
related to a vGPU.

Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h
index 254df8b..eff8af5 100644
--- a/drivers/gpu/drm/i915/gvt/hypercall.h
+++ b/drivers/gpu/drm/i915/gvt/hypercall.h
@@ -19,6 +19,15 @@
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
+ *
+ * Authors:
+ *    Eddie Dong <eddie.dong@intel.com>
+ *    Dexuan Cui
+ *    Jike Song <jike.song@intel.com>
+ *
+ * Contributors:
+ *    Zhi Wang <zhi.a.wang@intel.com>
+ *
  */
 
 #ifndef _GVT_HYPERCALL_H_
@@ -30,6 +39,8 @@
  */
 struct intel_gvt_mpt {
 	int (*detect_host)(void);
+	int (*attach_vgpu)(void *vgpu, unsigned long *handle);
+	void (*detach_vgpu)(unsigned long handle);
 };
 
 extern struct intel_gvt_mpt xengt_mpt;