[MoE Refactor][15/N] Apply Refactor to Fp8

[robertgshaw2-redhat]

Purpose

SUMMARY:

• continue refactoring fp8 moe
• CUTLASS MoE --> make CutlassExpertsFp8 manage the strides data
• CUTLASS MoE --> remove cutlass_moe_fp8 entrypoint
• factor out MoE kernel selection into a new module
• factor out process_weights_after_loading utilities to be shared by fp8 and ct
• apply mk refactor to ct

Test Plan

• unit tests

pytest -v -x tests/kernels/moe/test_cutlass_moe.py

• benchmark scripts (note: these don't work on main)

python3 ./benchmark_grouped_gemm_cutlass.py --model "deepseek-ai/DeepSeek-V2-Lite" --tp-sizes 4 --batch-sizes 2 4

python benchmark_cutlass_moe_fp8.py  \
            --model "Llama-4-Maverick-17B-128E-Instruct-FP8"  \
            --tp-sizes 8 \
            --batch-size 2 4 8 \
            --per-act-token-opts false \
            --per-out-ch-opts false

• moe refactor integration tests

Test Result

---

Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.
• (Optional) Release notes update. If your change is user facing, please update the release notes draft in the Google Doc.

[mgoin]

What is this? Do you just want to add it to the eval script here

vllm/tests/evals/gsm8k/test_gsm8k_correctness.py

Lines 60 to 65 in c907d22

	# Add standard server arguments
	server_args.extend(
	[
	"--trust-remote-code",
	]
	)

[robertgshaw2-redhat]

yeah, thats a good idea. It makes the logs much easier to read by not logging out /completions every request

[mgoin]

I think we should just put each import within each conditional, rather than importing all

[bnellnm]

Nice refactor!

[zyongye]

The overall structure LGTM. But we will need to revisit the fallback experts abstraction in the future as discussed.

[zyongye]

Should we register this inside the FusedMoEMethod? instead of in the utils?

[robertgshaw2-redhat]

there is some work to make TRTLLM a modular kernel. once that is done, we can revisit it

[mgoin]

Great work!