[Intel-gfx] [PATCH i-g-t] i915: Improve static engine map for legacy

[Tvrtko Ursulin]

On 23/05/2019 10:14, Chris Wilson wrote:
> Quoting Chris Wilson (2019-05-23 10:09:48)
>> Quoting Tvrtko Ursulin (2019-05-23 09:46:08)
>>>
>>> On 23/05/2019 09:06, Chris Wilson wrote:
>>>>    const struct intel_execution_engine2 intel_execution_engines2[] = {
>>>> -     { "rcs0", I915_ENGINE_CLASS_RENDER, 0 },
>>>> -     { "bcs0", I915_ENGINE_CLASS_COPY, 0 },
>>>> -     { "vcs0", I915_ENGINE_CLASS_VIDEO, 0 },
>>>> -     { "vcs1", I915_ENGINE_CLASS_VIDEO, 1 },
>>>> -     { "vcs2", I915_ENGINE_CLASS_VIDEO, 2 },
>>>> -     { "vecs0", I915_ENGINE_CLASS_VIDEO_ENHANCE, 0 },
>>>> +     { "rcs0", I915_ENGINE_CLASS_RENDER, 0, I915_EXEC_RENDER },
>>>> +     { "bcs0", I915_ENGINE_CLASS_COPY, 0, I915_EXEC_BLT },
>>>> +     { "vcs0", I915_ENGINE_CLASS_VIDEO, 0, I915_EXEC_BSD | I915_EXEC_BSD_RING1 },
>>>
>>> execbuf will reject this on single vcs parts. :( Am I not seeing some
>>> place where you fudge it into compliance?
>>
>>
>>          if (user_ring_id == I915_EXEC_BSD && HAS_ENGINE(dev_priv, VCS1)) {
>>                  unsigned int bsd_idx = args->flags & I915_EXEC_BSD_MASK;
>>
>>                  if (bsd_idx == I915_EXEC_BSD_DEFAULT) {
>>                          bsd_idx = gen8_dispatch_bsd_engine(dev_priv, file);
>>                  } else if (bsd_idx >= I915_EXEC_BSD_RING1 &&
>>                             bsd_idx <= I915_EXEC_BSD_RING2) {
>>                          bsd_idx >>= I915_EXEC_BSD_SHIFT;
>>                          bsd_idx--;
>>                  } else {
>>                          DRM_DEBUG("execbuf with unknown bsd ring: %u\n",
>>                                    bsd_idx);
>>                          return NULL;
>>                  }
>>
>>                  engine = dev_priv->engine[_VCS(bsd_idx)];
>>          } else {
>>                  engine = dev_priv->engine[user_ring_map[user_ring_id]];
>>          }
>>
>> Looks ok to me... I was trying to double check but dif didn't boot on
>> bsw. Sigh.
> 
> So instead I removed vcs1 from bdw, and vcs0 continues to work.
> 
> What is still incorrect though:
> $ ./build/tests/gem_exec_parallel --list-subtests
> ...
> vcs0
> vcs0-contexts
> vcs0-fds
> vcs1
> vcs1-contexts
> vcs1-fds
> vcs2
> vcs2-contexts
> vcs2-fds
> ...

As you know this part is correct since CI mandates we list subtests not 
applicable to running platform.

> $ sudo ./build/tests/gem_exec_parallel --run vcs1
> IGT-Version: 1.23-g82137ba4 (x86_64) (Linux: 5.2.0-rc1+ x86_64)
> (gem_exec_parallel:16219) igt_core-WARNING: Unknown subtest: vcs1

I guess we need to make the library function igt_skip instead of not 
enumerating the impossible and missing engines.

But it doesn't work.. skips need to be in either subtests or fixtures.

Perhaps the idea of using a single context aware iterator has therefore 
fail and we do need two separate ones. :( One just for subtest 
enumeration which *only* uses the static list, and another for use in 
tests, which skips missing/impossible engines depending on context.

Regards,

Tvrtko