[PATCH 01/13] drm/amdgpu: introduce and honour DRM_FORCE_AUTH workaround

[Koenig, Christian]

Am 21.06.19 um 09:41 schrieb Michel Dänzer:
> On 2019-06-21 9:12 a.m., Koenig, Christian wrote:
>> First of all I tried to disable DRM authentication completely with a
>> kernel config option. Surprisingly that actually works out of the box at
>> least on the AMDGPU stack.
>>
>> This effectively allows us to get rid of DRI2 and the related security
>> problems. Only thing left for that is that I'm just not sure how to
>> signal this to userspace so that the DDX wouldn't advertise DRI2 at all
>> any more.
> FWIW, getting rid of DRI2 also needs to be discussed with amdgpu-pro
> OpenGL driver folks.

Good point, but I don't expect much problems from that direction.

IIRC they where quite happy to not have to support DRI2 except for a 
very very old X server version.

>> As a next step I looked into if we can disable the command submission
>> for DRM master. Turned out that this is relatively easy as well.
>>
>> All we have to do is to fix the bug Michel pointed out about KMS handles
>> for display
> I'm working on that, consider it fixed.
>
>
>> and let the DDX use a render node instead of the DRM master for Glamor.
>> Still need to sync up with Michel and/or Marek whats the best way of
>> doing this.
> My suggestion was to add a new variant of amdgpu_device_initialize. When
> the new variant is called, libdrm_amdgpu internally uses a render node
> for command submission etc. whenever possible.

Yeah, sounds like a plan to me.

Christian.