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

[Emil Velikov]

HI Gerd,

On Tue, 30 Oct 2018 at 06:11, Gerd Hoffmann <kraxel at redhat.com> wrote:
>
>   Hi,
>
> > The execbuffer IOCTL is now read-write to allow the userspace to read the
> > out-fence.
>
> >  #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