Re: [PATCH v15 5/7] vfio: ABI for mdev display dma-buf operation

From: Gerd Hoffmann
Date: Tue Oct 10 2017 - 10:07:41 EST


On Tue, 2017-10-10 at 17:50 +0800, Tina Zhang wrote:
> Add VFIO_DEVICE_QUERY_GFX_PLANE ioctl command to let user mode query
> and
> get the plan and its related information. This ioctl can be invoked
> with:
> 1) either flag DMABUF or REGION is set. Vendor driver returns success
> and
> the plane_info only when the specific kind of buffer is supported.
> 2) flag PROBE is set with either DMABUF or REGION. Vendor driver
> returns
> success only when the specific kind of buffer is supported.
>
> The dma-buf's life cycle is handled by user mode and tracked by
> kernel.
> The returned fd in struct vfio_device_query_gfx_plane can be a new
> fd or an old fd of a re-exported dma-buf. Host user mode can check
> the
> value of fd and to see if it needs to create new resource according
> to
> the new fd or just use the existed resource related to the old fd.

Reviewed-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>

cheers,
Gerd