[Intel-gfx] [FW: [PATCH 3/6] drm/i915/gtt: Disable read-only support under GVT]

[Chris Wilson]

Quoting Yuan, Hang (2018-10-25 11:07:48)
> Hi Chris,
> 
> I checked GVT shadow PPGTT handling codes and think GVT does propagate guest PTE flags to shadow PPGTT entry. Then I run i915 self-test case "igt_ctx_readonly" in KVMGT's guest. The case doesn't report any errors. Can I know if there are any other reasons that you think GVT breaks read-only support?

I thought it was from a ci result, but going back through the logs we
have never run the selftests at that time under CI. So call it a lack of
testing and a misread of the code.

igt_ctx_readonly should be sufficient to prove the test, except it needs
a bit of refinement to be stricter over hang detection.
https://patchwork.freedesktop.org/patch/256433/
-Chris