RE: [RFC PATCH 6/6] drm/i915/gvt: support QEMU getting the dmabuf

[Chen, Xiaoguang]

Hi Gerd,

>-----Original Message-----
>From: intel-gvt-dev [mailto:intel-gvt-dev-bounces@xxxxxxxxxxxxxxxxxxxxx] On
>Behalf Of Gerd Hoffmann
>Sent: Friday, May 19, 2017 4:57 PM
>To: Chen, Xiaoguang <xiaoguang.chen@xxxxxxxxx>
>Cc: Tian, Kevin <kevin.tian@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
>zhenyuw@xxxxxxxxxxxxxxx; Alex Williamson <alex.williamson@xxxxxxxxxx>; Lv,
>Zhiyuan <zhiyuan.lv@xxxxxxxxx>; intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx; Wang, Zhi
>A <zhi.a.wang@xxxxxxxxx>
>Subject: Re: [RFC PATCH 6/6] drm/i915/gvt: support QEMU getting the dmabuf
>
>  Hi,
>
>> >We could also do it the other way around:  Instead of having the
>> >kernel returning
>>
>> >the plane description userspace could pass it in, and the kernel
>> >throws -EINVAL in
>>
>> >case it doesn't match due to things having changed meanwhile.
>>
>> Or just return a dmabuf  based on the current plane ?
>
>If gvt is able to hand out dma-bufs for inactive planes, then yes, we can do this.
>Have one ioctl where we pass in the plane id, get back a plane description struct,
>and another where we pass in the plane description struct and get back a dma-
>buf fd.
Or more simply just pass the plane id, because even the plane description did not match the current one we will eventually create a dmabuf based on current plane.

>
>cheers,
>  Gerd
>
>_______________________________________________
>intel-gvt-dev mailing list
>intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx
>https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev