Linux Virtualization - Sep 2015 - [PATCH 5/5] virtgpu: mark as a render gpu

On 10 September 2015 at 15:52, Gerd Hoffmann <kraxel at redhat.com>
wrote:
>   Hi,
>
>> > Dave?  Looking at the ioctls they are all fine for render nodes,
there
>> > isn't anything modesetting related in the device-specific
ioctls.
>> >
>> > Correct?
>> >
>> Unless I've overdone the coffee this time - modesetting is done via
>> the card# node, while render via either card# or renderD#.
>
> Exactly, thats why anything modesetting-related must be disabled for
> renderD#.  Looking at the virtio-gpu device-specific ioctls I don't
> think there is anything doing modesetting (which we would have to leave
> out), so we can apply DRM_RENDER_ALLOW everythere I think.  Or maybe
> there is a global switch to flip DRM_RENDER_ALLOW for the whole list ...
>
IMHO the idea of having a 'global' switch sounds quite good, yet there
isn't one atm :-( It will be quite useful as we get more render only
devices.
DRIVER_RENDER doesn't do that unfortunately (which I think was the
original assumption), it only instructs drm core to create the
renderD# device/node.

Hope this clears up any ambiguity from my earlier replies :-)
Emil

On 11 September 2015 at 01:04, Emil Velikov <emil.l.velikov at gmail.com>
wrote:
> On 10 September 2015 at 15:52, Gerd Hoffmann <kraxel at redhat.com>
wrote:
>>   Hi,
>>
>>> > Dave?  Looking at the ioctls they are all fine for render
nodes, there
>>> > isn't anything modesetting related in the device-specific
ioctls.
>>> >
>>> > Correct?
>>> >
>>> Unless I've overdone the coffee this time - modesetting is done
via
>>> the card# node, while render via either card# or renderD#.
>>
>> Exactly, thats why anything modesetting-related must be disabled for
>> renderD#.  Looking at the virtio-gpu device-specific ioctls I don't
>> think there is anything doing modesetting (which we would have to leave
>> out), so we can apply DRM_RENDER_ALLOW everythere I think.  Or maybe
>> there is a global switch to flip DRM_RENDER_ALLOW for the whole list
...
>>
> IMHO the idea of having a 'global' switch sounds quite good, yet
there
> isn't one atm :-( It will be quite useful as we get more render only
> devices.
> DRIVER_RENDER doesn't do that unfortunately (which I think was the
> original assumption), it only instructs drm core to create the
> renderD# device/node.
doh, yes we need to add DRM_RENDER_ALLOW to the ioctls, can you do that?

Dave.

On Fr, 2015-09-11 at 16:32 +1000, Dave Airlie wrote:
> doh, yes we need to add DRM_RENDER_ALLOW to the ioctls, can you do
> that?
Done.

cheers,
  Gerd