Most likely mesa were broken with commit:
commit a363bb2cd0e2a141f2c60be005009703bffcbe4e
Author: Kenneth Graunke <email address hidden>
Date: Tue Apr 10 01:18:25 2018 -0700
i965: Allocate VMA in userspace for full-PPGTT systems.
In the kernel (especially 32-bit) it requires such commits (all of them are present from kernel 4.19.3):
1. commit 0014868b9c3c1dda1de6711cf58c3486fb422d07
Author: Chris Wilson <email address hidden>
Date: Fri Nov 2 16:12:09 2018 +0000
drm/i915: Mark pin flags as u64
2. commit 085603287452fc96376ed4888bf29f8c095d2b40
Author: Chris Wilson <email address hidden>
Date: Thu Oct 25 10:18:23 2018 +0100
drm/i915: Compare user's 64b GTT offset even on 32b
3. commit c58281056a8b26d5d9dc15c19859a7880835ef44
Author: Chris Wilson <email address hidden>
Date: Thu Oct 25 10:18:22 2018 +0100
drm/i915: Mark up GTT sizes as u64
4. commit 83b466b1dc5f0b4d33f0a901e8b00197a8f3582d
Author: Chris Wilson <email address hidden>
Date: Fri Nov 2 16:12:09 2018 +0000
drm/i915: Mark pin flags as u64
5. commit 6fc4e48f9ed46e9adff236a0c350074aafa3b7fa
Author: Chris Wilson <email address hidden>
Date: Thu Oct 25 10:18:23 2018 +0100
drm/i915: Compare user's 64b GTT offset even on 32b
So its question to Chris if he could propagate such commits into kernel. Because looks like even 4.15 is commonly used still.
Most likely mesa were broken with commit: 1f2c60be0050097 03bffcbe4e
commit a363bb2cd0e2a14
Author: Kenneth Graunke <email address hidden>
Date: Tue Apr 10 01:18:25 2018 -0700
i965: Allocate VMA in userspace for full-PPGTT systems.
In the kernel (especially 32-bit) it requires such commits (all of them are present from kernel 4.19.3): a1de6711cf58c34 86fb422d07
1. commit 0014868b9c3c1dd
Author: Chris Wilson <email address hidden>
Date: Fri Nov 2 16:12:09 2018 +0000
drm/i915: Mark pin flags as u64
2. commit 085603287452fc9 6376ed4888bf29f 8c095d2b40
Author: Chris Wilson <email address hidden>
Date: Thu Oct 25 10:18:23 2018 +0100
drm/i915: Compare user's 64b GTT offset even on 32b
3. commit c58281056a8b26d 5d9dc15c19859a7 880835ef44
Author: Chris Wilson <email address hidden>
Date: Thu Oct 25 10:18:22 2018 +0100
drm/i915: Mark up GTT sizes as u64
4. commit 83b466b1dc5f0b4 d33f0a901e8b001 97a8f3582d
Author: Chris Wilson <email address hidden>
Date: Fri Nov 2 16:12:09 2018 +0000
drm/i915: Mark pin flags as u64
5. commit 6fc4e48f9ed46e9 adff236a0c35007 4aafa3b7fa
Author: Chris Wilson <email address hidden>
Date: Thu Oct 25 10:18:23 2018 +0100
drm/i915: Compare user's 64b GTT offset even on 32b
So its question to Chris if he could propagate such commits into kernel. Because looks like even 4.15 is commonly used still.