drm/i915/gvt: add enable_execlists check before enable gvt

The GVT-g needs execlists to be enabled otherwise gvt should be
disabled. Add a check for enable_execlists before enabling gvt.

v2: use DRM_INFO in response to the user action
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/intel_gvt.c

@@ -77,6 +77,11 @@ int intel_gvt_init(struct drm_i915_private *dev_priv)
 		goto bail;
 	}
 
+	if (!i915.enable_execlists) {
+		DRM_INFO("GPU guest virtualisation [GVT-g] disabled due to disabled execlist submission [i915.enable_execlists module parameter]\n");
+		goto bail;
+	}
+
 	/*
 	 * We're not in host or fail to find a MPT module, disable GVT-g
 	 */