drm/virtio: implement context init: advertise feature to userspace

This advertises the context init feature to userspace, along with
a mask of supported capabilities.
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Acked-by: Lingfeng Yang <lfy@google.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20210921232024.817-13-gurchetansingh@chromium.orgSigned-off-by: Gerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/virtio/virtgpu_ioctl.c

@@ -286,6 +286,12 @@ static int virtio_gpu_getparam_ioctl(struct drm_device *dev, void *data,
 	case VIRTGPU_PARAM_CROSS_DEVICE:
 		value = vgdev->has_resource_assign_uuid ? 1 : 0;
 		break;
+	case VIRTGPU_PARAM_CONTEXT_INIT:
+		value = vgdev->has_context_init ? 1 : 0;
+		break;
+	case VIRTGPU_PARAM_SUPPORTED_CAPSET_IDs:
+		value = vgdev->capset_id_mask;
+		break;
 	default:
 		return -EINVAL;
 	}