drm/virtgpu api: host visible feature

This exposes the host visible feature to userspace. Without it,
it is an error to specify BLOB_MEM_HOST3D with
BLOG_FLAG_USE_MAPPABLE.

Signed-off-by: Gurchetan Singh <[e-mail]>
Acked-by: Tomeu Vizoso <[e-mail]>
Acked-by: Lingfeng Yang <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]
Signed-off-by: Gerd Hoffmann <[e-mail]>

include/uapi/drm/virtgpu_drm.h

···
 #define VIRTGPU_PARAM_3D_FEATURES 1 /* do we have 3D features in the hw */
 #define VIRTGPU_PARAM_CAPSET_QUERY_FIX 2 /* do we have the capset fix */
 #define VIRTGPU_PARAM_RESOURCE_BLOB 3 /* DRM_VIRTGPU_RESOURCE_CREATE_BLOB */
+#define VIRTGPU_PARAM_HOST_VISIBLE 4 /* Host blob resources are mappable */
 
 struct drm_virtgpu_getparam {
 	__u64 param;