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[Refactor] Abstract DeepGemm MegaMOE backend - #58053

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zyongye merged 6 commits into
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huishi-hs:deepgemm_megamoe_abstract
Oct 8, 2026
Merged

zyongye merged 6 commits into
vllm-project:mainfrom
huishi-hs:deepgemm_megamoe_abstract

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@huishi-hs

@huishi-hs huishi-hs commented Sep 22, 2026 •

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Purpose

Refactor DeepGemm MegaMoE integration behind a DeepGemmMegaMoEBackend abstraction to unblock non-SM100 backends; no behavior change on SM100. The DeepGEMM MegaMoE kernel is a very high-performance MoE implementation, and is expected to be reused by more models and hardware. For example:

  • An equivalent MXFP4 MegaMoE on SM90, where the activation quantization scheme has to change to fit the hardware and different precision requirements.
  • Today MXFP4 MoE weights are the default; follow-ups will likely need FP8 and other weight formats on top of the current implementation.

This PR adds an abstract DeepGemmMegaMoEBackend so more models can enable the DeepGEMM MegaMoE kernel quickly, and so external vLLM plugins can support more scenarios flexibly.

Main changes:

  • DeepGemmMegaMoEBackend currently exposes transform_weights (routed / shared), bf16_mega_gate, run_mega_moe, supports_shared_experts, and supports_bf16_mega_gate; it also abstracts mma_type and the hidden-state activation scheme.
  • The existing DeepGEMM usage in DeepSeek V4 and Kimi K3 is moved into DeepGemmSm100MegaMoEBackend, keeping the implementation completely unchanged.
  • prepare_megamoe_inputs is extended to support a new quantization mode fp8 with group_k=128 and fp32 scales.

Test Plan

  • On SM100, the code logic is unchanged, including DeepGemmSm100MegaMoEBackend and prepare_megamoe_inputs.
  • Test DeepGEMM MegaMoE variant on SM90.

Test Result

Run TP4+EP on hopper works correctly.

INFO 09-21 11:29:57 [__init__.py:90] [vllm_hopper_mega_moe] registered SM90 MegaMoE backend (DeepGemmSm90MegaMoEBackend) for DeepSeek V4.
INFO 09-21 11:29:57 [__init__.py:90] [vllm_hopper_mega_moe] registered SM90 MegaMoE backend (DeepGemmSm90MegaMoEBackend) for DeepSeek V4

Essential Elements of an Effective PR Description Checklist
  • The purpose of the PR, refactor MegaMoE integration behind a DeepGemmMegaMoEBackend abstraction to support more models and deepgemm megamoe backend; no behavior change on SM100.
  • 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.

@huishi-hs
huishi-hs requested a review from zyongye as a code owner September 22, 2026 02:13

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This pull request is from a fork — automated review is disabled. A repository maintainer can comment @claude review to run a one-time review.

@mergify mergify Bot added deepseek Related to DeepSeek models kimi k3 DSv4 labels Sep 22, 2026
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Thank you for the work. Once the comment is addressed we can merge to unblock you and I will come up with a comprehensive refactor in subsequent PRs.

Comment thread vllm/models/deepseek_v4/nvidia/model.py Outdated
self.num_logical_experts = (
num_logical_experts if num_logical_experts is not None else num_experts
)
class HiddenQuantSpec(typing.NamedTuple):

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Please use QuantKey abstraction

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Updated.
Use QuantKey in DeepGemmMegaMoEBackend and default value is kMxfp8Dynamic.
kMxfp8Dynamic is per-group quant with group size 32, match current sm100 mxfp4 mega moe default quant.

kMxfp8DynamicScale = ScaleDesc(torch.uint8, False, GroupShape(1, 32))
kMxfp8Dynamic = QuantKey(FP8_DTYPE, kMxfp8DynamicScale, symmetric=True)

passing QuantKey to prepare_megamoe_inputs, and will extract groupk and if scale is ue8m0 from QuantKey.

Comment thread vllm/models/deepseek_v4/nvidia/model.py Outdated
)
set_weight_attrs(self.w2_weight_scale, weight_attrs)
self.w2_weight_scale.quant_method = "block"
class DeepGemmMegaMoEBackend:

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We should put it into a separate file under model_executor/layers/fused_moe/ and create another DeepGemmMegaMoe.py

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DeepGemmMegaMoEBackend , DeepGemmSm100MegaMoEBackend and get_deep_gemm_mega_moe_backend api are moved to new file vllm/model_executor/layers/fused_moe/deep_gemm_mega_moe.py.

Left vllm/models/deepseek_v4/xpu/model.py unchanged in this PR. It has its own MegaMoE path: it imports vllm.third_party.deep_gemm directly instead of going through vllm.utils.deep_gemm. I'm not sure it targets the same DeepGEMM build/API as the CUDA path, so I'd rather not fold it into DeepGemmMegaMoEBackend without input from the XPU maintainers.

@huishi-hs

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Thank you for the work. Once the comment is addressed we can merge to unblock you and I will come up with a comprehensive refactor in subsequent PRs.

@zyongye Thanks for your review! All comments are addressed, please help review again.

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zyongye commented Oct 1, 2026

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/ci run

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❌ This PR is 649 commits behind upstream main. Your branch must contain every commit currently on upstream main. No new CI build was started. Merge or rebase onto the latest main, then rerun /ci run. To test this branch at your own risk, use /ci run --allow-stale.

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zyongye requested a review from wzhao18 as a code owner October 1, 2026 21:50
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/ci run

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zyongye enabled auto-merge (squash) October 1, 2026 21:50
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@github-actions github-actions Bot added the ready ONLY add when PR is ready to merge/full CI is needed label Oct 1, 2026
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✅ Triggered Buildkite CI #92497 for commit fa1ce5c1a382.

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zyongye commented Oct 1, 2026

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Thanks. Could you fix the DCO?

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mergify Bot commented Oct 5, 2026

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This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @huishi-hs.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

@mergify mergify Bot added the needs-rebase label Oct 5, 2026
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vllm-agent commented Oct 5, 2026 •

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CI selector (shadow): 29 test steps (70 jobs) instead of 73 (99 jobs)

Shadow mode: this changes nothing about what CI runs. It shows what the evidence-based selector would pick for this PR, next to today's rules. How it works.

Feedback welcome: reply here if it would skip a step this change needs, or runs something unrelated.

steps (jobs) Today's rules Selector Would skip Would add
NVIDIA, CPU and others 73 (99) 29 (70) 60 (76) 16 (47)
AMD mirrors 79 (116) 3 (3) 76 (113) 0 (0)
Selector would run (29)
  • arm-cpu-test ×3
  • basic-models-tests-extra-initialization ×14
  • basic-models-tests-initialization
  • basic-models-tests-other
  • cpu-kernel-tests ×2
  • cpu-language-generation-and-pooling-model-tests ×3
  • cpu-multi-modal-model-tests-n ×4
  • cpu-params-env-tokenizers-parser
  • cpu-spec-decode-tests
  • deepseek-v4-kernel-test-b200
  • deepseek-v4-kernel-test-h100
  • distributed-dp-tests-4-gpus
  • distributed-model-tests-2-gpus ×3
  • engine
  • kernels-attention-test ×7
  • kernels-flashmla-test-h100
  • kernels-mhc-test-b200
  • kernels-root-misc-test-b200
  • kimi-k3-unit-tests-b200
  • kv-offload-large
  • language-models-tests-extra-standard ×2
  • language-models-tests-standard
  • model-executor
  • multi-modal-processor ×4
  • multi-modal-processor-cpu ×4
  • quantization ×4
  • v1-attention-b200 ×2
  • v1-attention-h100-mi300 ×2
  • v1-spec-decode
Would skip (today's rules run them) (60)
  • amd-fp8-moe-kernels-mi355
  • amd-qwen3-next-mtp-async-eplb-accuracy
  • ascend-npu-test
  • async-engine-inputs-utils-worker
  • basic-correctness ×2
  • basic-correctness-cpu-offload
  • basic-correctness-cumem
  • basic-correctness-prefetch-offload
  • basic-correctness-sleep-mode
  • basic-models-test-other-cpu
  • batch-invariance-b200
  • batch-invariance-h100
  • benchmarks-cli-test
  • distributed-compile-unit-tests-2xh100
  • entrypoints-integration-api-server ×4
  • entrypoints-integration-api-server-generate
  • entrypoints-integration-api-server-openai-chat_completion
  • entrypoints-integration-api-server-openai-completion
  • entrypoints-integration-llm
  • entrypoints-integration-multimodal
  • entrypoints-integration-pooling
  • entrypoints-integration-responses-api
  • entrypoints-integration-speech_to_text
  • fusion-e2e-quick-h100
  • fusion-e2e-tp2-ar-rms-dynamo-partition-amd
  • fusion-e2e-tp2-ar-rms-inductor-partition-amd
  • fusion-e2e-tp2-b200
  • fusion-e2e-tp2-quick-h100
  • kernels-deepgemm-test-h100
  • kernels-fla-ops-test-b200
  • kernels-fusedmoe-layer-test-2-b200s
  • kernels-fusedmoe-layer-test-2-h100s
  • kernels-moe-test ×5
  • kimi-k3-prefix-cache-4xb200 ×2
  • language-models-tests-granite-l4-compatibility
  • language-models-tests-hybrid ×2
  • lora-tp-distributed ×4
  • metrics-tracing-2-gpus
  • multi-modal-models-standard-1-qwen2
  • multi-modal-models-standard-2-qwen3-gemma
  • multi-modal-models-standard-3-llava-qwen2-vl
  • multi-modal-models-standard-4-other-whisper
  • pytorch-compilation-dynamic-shapes
  • pytorch-compilation-passes-unit-tests
  • pytorch-compilation-unit-tests
  • pytorch-compilation-unit-tests-h100
  • pytorch-fullgraph-cudagraph-l4-compatibility
  • pytorch-fullgraph-test
  • quantized-moe-test-b200
  • regression
  • rl-entrypoints-tests
  • samplers-multimodal-beam-search
  • samplers-test
  • v1-core
  • v1-executor-worker
  • v1-kv-connectors ×4
  • v1-kv-offload
  • v1-logits-oracle
  • v1-metrics-lmeval
  • v1-sample
Would add (today's rules do not run them) (16)
  • arm-cpu-test ×3 (code map)
  • basic-models-tests-extra-initialization ×14 (code map)
  • cpu-kernel-tests ×2 (code map)
  • cpu-multi-modal-model-tests-n ×4 (code map)
  • cpu-params-env-tokenizers-parser (code map)
  • cpu-spec-decode-tests (code map)
  • deepseek-v4-kernel-test-h100 (code map)
  • distributed-dp-tests-4-gpus (code map)
  • engine (code map)
  • kernels-attention-test ×7 (code map)
  • kernels-flashmla-test-h100 (code map)
  • kv-offload-large (code map)
  • language-models-tests-extra-standard ×2 (code map)
  • quantization ×4 (code map)
  • v1-attention-b200 ×2 (code map)
  • v1-attention-h100-mi300 ×2 (code map)
AMD mirrors: would skip (76)
  • async-engine-inputs-utils-worker
  • basic-correctness ×2
  • basic-correctness-cpu-offload
  • basic-correctness-cumem
  • basic-correctness-prefetch-offload
  • basic-correctness-sleep-mode
  • basic-models-tests-extra-initialization ×14
  • basic-models-tests-initialization
  • batch-invariance-h100
  • benchmarks-cli-test
  • deepseek-v4-kernel-test-b200
  • distributed-compile-unit-tests-2xh100
  • distributed-model-tests-2-gpus ×3
  • entrypoints-integration-api-server ×4
  • entrypoints-integration-api-server-generate
  • entrypoints-integration-api-server-openai-chat_completion
  • entrypoints-integration-api-server-openai-completion
  • entrypoints-integration-llm
  • entrypoints-integration-multimodal
  • entrypoints-integration-pooling
  • entrypoints-integration-responses-api
  • entrypoints-integration-speech_to_text
  • fault-tolerance-e2e-2xh100
  • fusion-and-compile-unit-tests-2xb200
  • fusion-e2e-quick-h100
  • fusion-e2e-tp2-ar-rms-config-sweep-h100
  • fusion-e2e-tp2-b200
  • fusion-e2e-tp2-quick-h100
  • kernels-fla-ops-test-b200
  • kernels-fp4-moe-test-b200
  • kernels-fusedmoe-layer-test-2-b200s
  • kernels-fusedmoe-layer-test-2-h100s
  • kernels-moe-test ×5
  • kernels-root-misc-test-b200
  • language-models-tests-extra-standard ×2
  • language-models-tests-granite-l4-compatibility
  • language-models-tests-hybrid ×2
  • language-models-tests-standard
  • lora-tp-distributed ×4
  • metrics-tracing-2-gpus
  • model-executor
  • multi-modal-models-standard-1-qwen2
  • multi-modal-models-standard-2-qwen3-gemma
  • multi-modal-models-standard-3-llava-qwen2-vl
  • multi-modal-models-standard-4-other-whisper
  • multi-modal-processor ×4
  • openai-api-correctness
  • pipeline-context-parallelism-4-gpus
  • platform-tests
  • pytorch-compilation-dynamic-shapes
  • pytorch-compilation-passes-unit-tests
  • pytorch-compilation-unit-tests
  • pytorch-compilation-unit-tests-h100
  • pytorch-fullgraph-cudagraph-l4-compatibility
  • pytorch-fullgraph-test
  • quantized-moe-test-b200
  • regression
  • rl-entrypoints-tests
  • samplers-multimodal-beam-search
  • samplers-test
  • spec-decode-draft-model ×4
  • spec-decode-eagle-1-deepseek-qwen
  • spec-decode-eagle-2-llama3-qwen-vl-other
  • spec-decode-mtp-deepseek-mimo
  • spec-decode-mtp-gemma4
  • spec-decode-mtp-qwen3-5
  • spec-decode-ngram-suffix
  • spec-decode-speculators
  • v1-core
  • v1-executor-worker
  • v1-kv-connectors ×4
  • v1-kv-offload
  • v1-logits-oracle
  • v1-metrics-lmeval
  • v1-sample
  • v1-spec-decode
AMD mirrors: would add (0)

none

5 changed files · base a58bdd0d4e · head 1384d18dac · Python record: build 93039 at 1e5d0ea888 · kernel record: table 43b4aae (build 93244), map 43b4aae · not counted: 10 build steps, 5 A100 steps the generator no longer emits, 15 optional steps the selector would also run

huishi-hs and others added 2 commits October 7, 2026 21:47
Co-authored-by: Hui Shi <kalinshi@tencent.com>
Co-authored-by: LuneExplorer <liyihan23@mails.tsinghua.edu.cn>
Co-authored-by: ArmageddonKnight <bojian@cs.toronto.edu>
Co-authored-by: Claude
Signed-off-by: Hui Shi <kalinshi@tencent.com>
…p8Dynamic

Signed-off-by: Hui Shi <kalinshi@tencent.com>
…/fused_moe/deep_gemm_mega_moe.py

Signed-off-by: Hui Shi <kalinshi@tencent.com>
@huishi-hs
huishi-hs force-pushed the deepgemm_megamoe_abstract branch from 3bc9c52 to 74a0da3 Compare October 7, 2026 14:50
@mergify mergify Bot removed the needs-rebase label Oct 7, 2026
@huishi-hs

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Thanks. Could you fix the DCO?

@zyongye

PR branch rebased with latest vllm code and fix DCO and other failures in test_deepseek_v4_mega_moe.py on sm100

1. Fix conflict with #59927

Move _finalize_shared_expert_weights change to new file vllm/model_executor/layers/fused_moe/deep_gemm_mega_moe.py

2. Fix failures in tests/models/test_deepseek_v4_mega_moe.py

The backend refactor caused several regressions in this test file:

  • Fix UE8M0 scale packing (prepare_megamoe.py): when packing the four
    UE8M0 scales into one int32, the kernel reduced over the wrong axis
    (axis=0 instead of axis=1). Now align with latest code.
  • Backend / symm buffer resolution order: DeepseekV4MegaMoEExperts
    and KimiK3MegaMoEExperts now call _ensure_backend() and
    get_symm_buffer() after routing capture and EPLB mapping, just before
    they are first used. This matches the order on main. Runtime behavior
    is unchanged, since the backend is cached in finalize_weights().
    Fixes test_deep_gemm_mega_moe_capture_precedes_eplb.
  • Optional activation kwargs:
    DeepGemmSm100MegaMoEBackend.transform_weights and run_mega_moe now
    pass activation, activation_alpha, and activation_beta to deep_gemm
    only when they are set. DeepSeek V4 therefore uses deep_gemm's defaults,
    as it does on main. Kimi K3 still passes them explicitly. The two
    duplicated fp8_fp4_mega_moe call sites are merged into one.
  • Test updates: the tests used to stub _check_runtime_supported,
    which the new code no longer calls. They now stub _ensure_backend to
    return DeepGemmSm100MegaMoEBackend(). FakeExperts in
    test_deepseek_v4_mega_moe_does_not_double_add_fused_shared_expert
    also gets _ensure_backend()/_backend, because DeepseekV4MoE.forward
    resolves the backend before routing.

Could you please help review again and trigger new CI test? Thanks!

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mergify Bot commented Oct 7, 2026

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Hi @huishi-hs, the pre-commit checks have failed. Please run:

uv pip install pre-commit>=4.5.1
pre-commit install
pre-commit run --all-files

Then, commit the changes and push to your branch.

For future commits, pre-commit will run automatically on changed files before each commit.

…moe.py regressions

- Fix UE8M0 scale packing in prepare_megamoe_inputs to reduce over the
  group axis (axis=1).
- Resolve the MegaMoE backend and symm buffer after EPLB mapping in
  DeepseekV4/KimiK3 MegaMoE experts forward, right before first use.
- Pass activation/activation_alpha/activation_beta to deep_gemm only
  when set, so DeepSeek V4 keeps deep_gemm defaults; merge the duplicated
  fp8_fp4_mega_moe call paths.
- Update MegaMoE tests to stub _ensure_backend instead of the removed
  _check_runtime_supported.

Signed-off-by: Hui Shi <kalinshi@tencent.com>
Signed-off-by: Hui Shi <kalinshi@tencent.com>
@huishi-hs

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Hi @huishi-hs, the pre-commit checks have failed. Please run:

uv pip install pre-commit>=4.5.1
pre-commit install
pre-commit run --all-files

Then, commit the changes and push to your branch.

For future commits, pre-commit will run automatically on changed files before each commit.

@zyongye
pre-commit failure is fixed.

@zyongye

zyongye commented Oct 8, 2026

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/ci run

@zyongye
zyongye enabled auto-merge (squash) October 8, 2026 00:16
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✅ Triggered Buildkite CI #93465 for commit 1384d18dac29.

@huishi-hs

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@zyongye

Thanks a lot for reviewing and approving this PR!

I noticed that one CI job failed: buildkite/ci/pr/nvidia-4xb200-kimi-k3-prefix-cache-shard-1

From the Buildkite log, the job never actually started running. The pod seems to have stayed pending for more than an hour and then timed out. It looks like an infra or resource-scheduling issue on the 4xB200 runners.

Could you help confirm whether this failure is a known infra issue? If the community is already working on a fix for the B200 runners, I'm happy to wait until it's resolved.

When convenient, could you please re-trigger this job (or the CI) for me? I don't have permission to retry Buildkite jobs. Thanks again for your time and help!

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zyongye commented Oct 8, 2026

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/ci retry

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github-actions Bot commented Oct 8, 2026

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✅ Queued 2 failed job(s) for retry in Buildkite CI #93465.

@zyongye
zyongye merged commit 81198e9 into vllm-project:main Oct 8, 2026
201 checks passed
michael-gpu pushed a commit to practical-inference/vllm-ampere-extended that referenced this pull request Oct 20, 2026
Signed-off-by: Hui Shi <kalinshi@tencent.com>
Co-authored-by: LuneExplorer <liyihan23@mails.tsinghua.edu.cn>
Co-authored-by: ArmageddonKnight <bojian@cs.toronto.edu>
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