Re: [PATCH 2/5] drm/virtio: add uapi for in and out explicit fences

HI Gerd,

On Tue, 30 Oct 2018 at 06:11, Gerd Hoffmann [off-list ref] wrote:

  Hi,

quoted

The execbuffer IOCTL is now read-write to allow the userspace to read the
out-fence.

quoted

 #define DRM_IOCTL_VIRTGPU_EXECBUFFER \
-     DRM_IOW(DRM_COMMAND_BASE + DRM_VIRTGPU_EXECBUFFER,\
+     DRM_IOWR(DRM_COMMAND_BASE + DRM_VIRTGPU_EXECBUFFER,\
              struct drm_virtgpu_execbuffer)

That changes the ioctl number and breaks the userspace api.

Have you looked at the drm_ioctl() implementation? AFAICT it
explicitly caters for this kind of changes.

-Emil