drm/i915: make intel_gvt_init() later instead of too early

Previously intel_gvt_init() was called very early even before
MMIO initialization which had several drawbacks:
- Have to handle MMIO access for initial MMIO state dump if golden
  state firmware is not available
- Hypervisor detection should depend on pvinfo only instead of detecting
  hypervisor status.
- Don't know hw resource size e.g aperture, ggtt size to determine
  for vGPU type, etc.

This trys to move intel_gvt_init() call late after required info
has already been initialized for GVT host.
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/i915_drv.c

@@ -824,10 +824,6 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 	if (ret < 0)
 		return ret;
 
-	ret = intel_gvt_init(dev_priv);
-	if (ret < 0)
-		goto err_workqueues;
-
 	/* This must be called before any calls to HAS_PCH_* */
 	intel_detect_pch(dev_priv);
 
@@ -841,7 +837,7 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 	intel_init_audio_hooks(dev_priv);
 	ret = i915_gem_load_init(dev_priv);
 	if (ret < 0)
-		goto err_gvt;
+		goto err_workqueues;
 
 	intel_display_crc_init(dev_priv);
 
@@ -853,8 +849,6 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 
 	return 0;
 
-err_gvt:
-	intel_gvt_cleanup(dev_priv);
 err_workqueues:
 	i915_workqueues_cleanup(dev_priv);
 	return ret;
@@ -1077,6 +1071,10 @@ static int i915_driver_init_hw(struct drm_i915_private *dev_priv)
 			DRM_DEBUG_DRIVER("can't enable MSI");
 	}
 
+	ret = intel_gvt_init(dev_priv);
+	if (ret)
+		goto out_ggtt;
+
 	return 0;
 
 out_ggtt:
@@ -1290,6 +1288,8 @@ void i915_driver_unload(struct drm_device *dev)
 
 	intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
 
+	intel_gvt_cleanup(dev_priv);
+
 	i915_driver_unregister(dev_priv);
 
 	drm_vblank_cleanup(dev);

drivers/gpu/drm/i915/intel_gvt.c

@@ -67,6 +67,11 @@ int intel_gvt_init(struct drm_i915_private *dev_priv)
 		return 0;
 	}
 
+	if (intel_vgpu_active(dev_priv)) {
+		DRM_DEBUG_DRIVER("GVT-g is disabled for guest\n");
+		goto bail;
+	}
+
 	if (!is_supported_device(dev_priv)) {
 		DRM_DEBUG_DRIVER("Unsupported device. GVT-g is disabled\n");
 		goto bail;